- SC A
NOx Emission Control Technology Installation Timing for Non-EGU
Sources
Final Report
EPA GSA Contract No. 47QRAA20D002W
BPA No. 68HERD21A0005
TO No. 68HERH22F0206
Prepared for:
Larry Sorrels
Office of Air Quality Planning and Standards
U.S. Environmental Protection Agency
Research Triangle Park, NC 27711
Submitted by:
SC&A, Inc.
1414 Raleigh Road, Suite 450
Chapel Hill, North Carolina 27517
March 14, 2023
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DISCLAIMER
This report presents the results of SC&A's research on questions pertaining to control installation timing
needs for industrial sources covered by the EPA's Good Neighbor Federal Implementation Plan (FIP) for
the 2015 ozone NAAQS. The report includes summaries of comments regarding control installation
timing needs that the EPA received during the public comment period and information obtained by
SC&A or the EPA from control technology vendors, state permitting staff, and other entities, but it does
not necessarily endorse or adopt the views of these commenters or other entities. Additionally,
although statements by individual state permitting staff and control-installation vendors have been
documented accurately and reflect these individuals' or entities' experiences and expertise, SC&A was
not able to independently verify or substantiate these statements in the time provided.
The information presented in this report regarding the potential for supply-chain delays reflects current
economic conditions (that is, conditions as of 2022) and current constraints on manufacturing capacity
and skilled labor relevant to pollution control installation. The report discusses to some extent whether
these conditions may be anticipated to continue into the future by considering several current economic
indicators, but because of a lack of information available to SC&A it does not project key economic
indicators that may be relevant to NOx control installation timing estimates for industries affected by
this final rule. Although the information presented in this report informed the EPA's evaluation of the
installation timing issues raised during the public comment period on the Good Neighbor FIP, this report
does not necessarily reflect the views of the EPA or EPA staff and does not constitute EPA endorsement
of any of the conclusions herein. This report does not supply facility-specific information that would be
relevant or reliable in any future determination of necessity for additional time, on a source-specific
basis, to come into compliance with any Clean Air Act requirement.
ii
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Table of Contents
Executive Summary ES-1
1. Introduction 1
2. Affected Industries—Emission Sources and Unique Issues 2
2.1 Cement and Concrete Product Manufacturing 2
2.2 Glass and Glass Products Manufacturing 4
2.3 Iron and Steel Mills and Ferroalloy Manufacturing 6
2.4 Pipeline Transportation of Natural Gas 8
2.5 Boilers in the Iron and Steel Mills and Ferroalloy Manufacturing, Basic Chemical
Manufacturing, Petroleum and Coal Products Manufacturing, Pulp, Paper, and Paperboard Mills, and
Metal Ore Mining Industries 9
2.6 Municipal Waste Combustors 12
3. Non-EGU NOx Emission Controls 17
3.1 External Combustion Controls 17
3.2 Internal Combustion Controls for Engines 19
4. Timing to Install Controls 21
4.1 Phases Common to Control Installations 21
4.2 Issues Identified by Commenters Related to Timing 26
4.3 Evaluation of Timing for Each Industry 27
4.4 Cumulative Effect of Numerous Control Installations at Same Time on Timing and Demand for
Materials and Services 36
4.5 Control Vendor Demand/Capacity 41
4.6 Permitting Processes 42
5. Potential for Supply Chain Delays and Constraints 47
5.1 Supply Chain Concerns 47
5.2 Regional Analysis of Demand and Available Supply of Labor 61
6. Summary of Results 65
6.1 Estimated Time Needed for Controls to be Installed on All Non-EGU Emissions Units 65
6.2 Estimated Time Needed for Non-EGU Emissions Units to Install Controls 65
6.3 Potential Impact of Supply Chain Constraints on Control Installation Timing 66
Appendix A. North American SCR and SNCR Suppliers A-l
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Tables
Table ES-1. Estimated Time Required to Achieve All Phases of NOx Control of Non-EGUs ES-2
Table ES-2. EGU and Non-EGU NOx Control Installations by State ES-4
Table 2-1. NOx Emission Limits of Kilns from the Cement and Concrete Industry 4
Table 2-2. Summary of Final NOx Control Requirements for Glass and Glass Product Industry 6
Table 2-3. Summary of Final NOx Control Requirements for the Iron and Steel Industry 8
Table 2-4. Proposed NOx Emission Limits for Natural Gas-Fired RICE in Pipeline Transportation of Natural
Gas 9
Table 2-5. NOx Emission Limits for Non-EGU Affected Industry Boilers 10
Table 2-6. NOx Emission Limits for Large MWCs 16
Table 4-1. Estimated Time Requirements for Individual Sources Affected by the Final Rule 25
Table 4-2. Potential Control Installations for Cement and Concrete Product Manufacturing 27
Table 4-3. ICAC Timeline for SNCR Installation for Cement and Concrete Product Manufacturing 28
Table 4-4. Potential Control Installations for Glass and Glass Product Manufacturing 29
Table 4-5. LNB or LNB+FGR Installation Timeline for Glass and Glass Products Manufacturing 30
Table 4-6. Potential Control Installations for Iron and Steel Mills and Ferroalloy Manufacturing 30
Table 4-7. Potential Control Installations for Pipeline Transportation of Natural Gas 31
Table 4-8. Timeline for Installation of NOx Controls for RICE in Pipeline Transportation of Natural Gas.. 32
Table 4-9. Potential Control Installations for Boilers in Affected Industries 33
Table 4-10. EPA's Estimated Potential Installation Timeline for Applying SCR to Boilers in the Affected
Industries 34
Table 4-11. Potential Control Installations for MWCs 35
Table 4-12. Estimated Time by Phase for Control Installation Options for a Large MWC (months) 35
Table 4-13. Potential Non-EGU and EGU Control Installations by the 2026 Ozone Season 36
Table 4-14. Estimated Demand for SCR or SNCR Projects by 2026 42
Table 4-15. Estimated Non-EGU NOx Control Installations by 2026 by State 44
Table 6-1. Summary of Expected Calendar Time Required for Control Installation for an Individual Source
65
Table A-l. SCR Vendors A-l
Table A-2. SCR Catalyst Manufacturers or Recyclers A-2
Table A-3. SNCR Vendors A-3
iv
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Figures
Figure 4-1. General Installation Timeline: Large Add-On Controls 22
Figure 4-2. General Installation Timeline: Combustion Controls or Compact Add-On Controls 22
Figure 5-1. US Inventory to Sales Ratio 49
Figure 5-2. Containerships Awaiting Berth 50
Figure 5-3. Interstate Vehicle-Miles Traveled (% Change from 2019) 51
Figure 5-4. Freight Transportation Services Index 51
Figure 5-5. Index of US Imported Goods 52
Figure 5-6. RSM US Supply Chain Index 53
Figure 5-7. RSM US Supply Chain Subindices 53
Figure 5-8. Global Supply Chain Index 54
Figure 5-9. US Manufacturing Capacity Utilization 55
Figure 5-10. Canadian Manufacturing Capacity Utilization 56
Figure 5-11. Mexican Manufacturing Capacity Utilization 57
Figure 5-12. US Nonfarm and Construction Employment 57
Figure 5-13. Historic US Natural Gas Production 61
Figure 5-14. Specialty Trade Contractors in Texas 62
Figure 5-15. Specialty Trade Contractors in Louisiana 62
Figure 5-16. Specialty Trade Contractors in Oklahoma 63
Figure 5-17. Specialty Trade Contractors in Ohio 63
Figure 5-18. Construction Backlog Indicator through September 2022 64
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ACRONYMS
ABC
Associated Builders and Contractors
AF&PC
Arkansas Forest & Paper Council
AISI
American Iron and Steel Institute
ASNCR
advanced selective noncatalytic reduction
BF
blast furnace
BLS
Bureau of Labor Statistics
BOF
basic oxygen furnace
BTS
Bureau of Transportation Statistics
Btu
British thermal unit
CAA
Clean Air Act
CAIR
Clean Air Interstate Rule
CBI
Construction Backlog Indicator
CEM
Continuous Emissions Monitor
CIBO
Council of Industrial Boiler Owners
CO
carbon monoxide
C02
carbon dioxide
EAF
electric arc furnace
EGU
electricity generating unit
EPA
United States Environmental Protection Agency
EPC
engineering, procurement, and construction
ESP
electro-static precipitator
FERC
United States Federal Energy Regulatory Commission
FGR
flue gas recirculation
FIP
Federal Implementation Plan
FTE
full-time equivalent
g
gram
hp
horsepower
hr
hour
ICAC
Institute of Clean Air Companies
ICI
industrial/commercial/institutional
IMA-NA
Industrial Minerals Association - North America
INGAA
Interstate Natural Gas Association of America
IR
ignition timing retard
lb
pound
LC
layered combustion
LDC
local distribution company
LDEQ
Louisiana Department of Environmental Quality
LEC
low emissions combustion
LMF
ladle metallurgy furnace
LNB
low NOx burner
LNtm
Covanta Patented Low NOx Technology
m
meter
m3
cubic meters
vi
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MMBtu
million British thermal units
MRRA
Minnesota Resource Recovery Association
MSW
municipal solid waste
MW
megawatt
MWC
municipal solid waste combustor
NAAQS
National Ambient Air Quality Standard
NAICS
North American Industry Classification System
NETL
National Energy Technology Labs
NGR
natural gas reburn
NNSR
nonattainment new source review
NSCR
non-selective catalytic reduction
NSR
New Source Review
non-EGU
non-electric generating unit
NOx
Nitrogen oxides
OEAS
oxygen enriched air staging
OEM
original equipment manufacturer
OFA
overfire air
PPb
parts per billion
ppmvd
parts per million by volume, dry
PM
particulate matter
PSD
Prevention of Significant Deterioration
PTE
Potential to Emit
RACT
Reasonably Available Control Technology
RDF
refuse-derived fuel
RFP
request for proposal
RFQ
request for quotation
RICE
reciprocating internal combustion engine
SMA
Steel Manufacturing Association
SSINA
Specialty Steel Industry of North America
SWANA
Solid Waste Association of North America
TCEQ
Texas Commissions on Environmental Quality
tpy
tons per year
TSD
Technical Support Document
SCD
supply chain delay
SCR
selective catalytic reduction
SNCR
selective noncatalytic reduction
ULNB
ultra-low NOx burner
USLM
U.S. Lime & Minerals
VOC
volatile organic compound
WPC
Wisconsin Paper Council
vii
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Executive Summary
The United States Environmental Protection Agency (EPA) proposed a "Good Neighbor" Federal
Implementation Plan (FIP) to address regional ozone transport for the 2015 ozone National Ambient Air
Quality Standard (NAAQS), which published in the Federal Register on April 6, 2022.1 This proposed rule
identified proposed oxides of nitrogen (NOx) emission limits for certain industrial stationary sources in
states that were determined by EPA to be impacting the ability of downwind states to meet the ozone
NAAQS.2 The objective of this report is to provide EPA with information on the amount of time needed
for non-electricity generating units (non-EGUs) in the specified industries to install the NOx control
technologies necessary to comply with the requirements of the final FIP.
To address the timing needs for installation of NOx emission controls in the non-EGU sectors covered by
the rule, the EPA enlisted SC&A, Inc. (SC&A) to examine a number of issues. These include:
• The time required to install NOx controls on affected NOx emission sources;
• The time required for state permitting staff to process permit modifications required for
compliance with the final rule;
• Constraints on skilled labor relevant to air pollution control installation; and
• Supply chain constraints.
These issues are summarized below.
Summary of Overall Control Installation Timing and Permit Processing Time Estimates
Based on our findings drawn from information taken from a variety of sources as discussed later in this
report, Table ES-1 provides a summary of the estimated range of calendar months needed for affected
sources to complete all phases of NOx control installation (design, engineering, vendor selection,
permitting, equipment fabrication, and control installation). These sources include prior technical
studies, comments received on the proposed FIP, and control equipment vendor contacts. Two timelines
are presented in Table ES-1 - the "Estimated Install Timeline" and the "Supply Chain Delay (SCD) Install
Timeline."
• The "Estimated Install Timeline" - This timeline does not factor in any supply chain or other
delays. It should be understood to reflect the amount of time expected to install the control at a
single affected unit without any consideration of supply chain delays. Under ideal
circumstances, without any supply chain delays, the entire estimated population of affected
units could be addressed within this timeline. There are situations for some affected units where
a single facility has multiple affected units. In those situations, the amount of time per control
installation could be reduced. An example is the application of compact SCR at a natural gas
compressor station. Where multiple RICE can be addressed at the same time, the amount of
calendar time per engine could be reduced (mainly through the time required to issue a single
1 EPA, Federal Implementation Plan Addressing Regional Ozone Transport for the 2015 Ozone National Ambient Air
Quality Standard, Proposed Rule, 87 FR 20036, April 6, 2022.
2 Updated air quality modeling and analysis by the EPA was completed, and as a result Alabama, Minnesota, and
Wisconsin will not be subject to non-EGU control requirements in the final FIP rulemaking. EPA is not finalizing a
FIP for Tennessee or Wyoming at this time. Also, while Nevada is still included for non-EGU requirements, no
existing affected industrial units under the final FIP were identified by EPA.
ES-1
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air permit modification for all affected RICE at the station). Sufficient data were not available to
conduct case-by-case assessments of where such situations might arise.
• SCD Install Timeline - In situations where supply chain delays are expected, based on current
economic conditions and capacities (that is, as of 2022), a separate set of estimates
incorporates our best estimates of the length of such delays ("SCD Install Timeline"). These
estimates should be understood to reflect not only economic conditions and capacities as of
2022 but also the time required to address the entire population of affected units, if these
supply chain delays were to continue unabated into the future. However, as noted later in the
report, the most recent economic data tend to indicate that supply chain disruptions observed
in the 2020-2022 timeframe associated with the pandemic and the war in Ukraine may already
be lessening.
In cases where the timeline in both the "Estimated Install Timeline" and "SCD Install Timeline" columns
is the same, there is no significant supply chain delay that results in a change to the initial "Estimated
Install Timeline." In other words, in these cases, it would be possible for all units to be controlled in the
same timeframe as a single unit.
The NOx controls represented in Table ES-1 are low NOx burners (LNB), selective catalytic reduction
(SCR); selective non-catalytic reduction (SNCR); non-selective catalytic reduction (NSCR); low NOx burner
and flue gas recirculation (LNB + FGR); Covanta's patented Low NOx Technology (LNtm) + SNCR; and
advanced selective noncatalytic reduction (ASNCR).
Table ES-1. Estimated Time Required to Achieve All Phases of NOx Control of Non-EGUs
Estimated
SCD
Install
Install
Emissions
Control
Estimated
Timeline
Timeline
Industry
Source Group
Technology
Installs
(months)3
(months)3
Cement and
Kilns
SNCR
16
17-24
35-58
Concrete Product
Manufacturing
Glass and Glass
Melting
LNB
61
9 -15
9 -15
Product
Furnaces
Manufacturing
Iron and Steel
Reheat
LNB
19
9 -15
9 -15
Mills and
Furnaces
Ferroalloy
Manufacturing
Pipeline
RICE 2-Cycle
Layered
394
6 -12
40-72*
Transportation of
Combustion
Natural Gasb
Pipeline
RICE 4-Cycle
NSCR
30
6 -12
6 -12
Transportation of
Rich Burn
Natural Gasb
ES-2
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Industry
Emissions
Source Group
Control
Technology
Estimated
Installs
Estimated
Install
Timeline
(months)3
SCD
Install
Timeline
(months)3
Pipeline
Transportation of
Natural Gasb
RICE
unspecified
NSCRor
Layered
Combustion
323
6 -12
40-72*
Pipeline
Transportation of
Natural Gasb
RICE 4-Cycle
Lean Burn
reciprocating
SCR
158
10 -19
10 -19
Affected Non-EGU
Industries0
Boilers
LNB+ FGR
151
9 -15
9 -15
Affected Non-EGU
Industries0
Boilers
SCR
15
14-25
26-37
Municipal Waste
Management
MWC Boilers
LNtm + SNCR
4
22-28
22-28
Municipal Waste
Management
MWC Boilers
ASNCR
57
17-23
35-57
* We note that the 72-month estimates reflect an upper-bound assumption relating to how many
potentially affected engine units are old enough to necessitate specialized labor, which is
currently (as of 2022) found to be in limited supply. Further caveats associated with these
estimates are discussed elsewhere in the report.
Timeframe for Permitting Processes
In general, we estimate that any permit needed for control installations at an individual source can be
issued within a few weeks or months for minor modifications, and within a year for control installations
that trigger major modification permitting requirements. For certain states with large numbers of
affected sources, there could be a need for additional time, up to a year, to issue necessary permits,
e.g., if state resource levels remain unchanged and the state lacks expedited permitting processes. In all
cases, any necessary permitting should be complete within a two-year timeframe, and other aspects of
control installation can likely proceed to some extent in tandem with the permitting process. We have
not added time needed for issuance of permits onto the SCD install timeline because, in the event that
supply-chain delays extend the installation timeframe beyond the 3-year period leading to 2026, the
permitting process likely would not impact that installation timeframe, as permitting can occur within
this timeframe and any potential supply chain delays should not delay the permitting process.
Some state permitting authorities may have a larger permit modification labor burden than others. This
is due to both the estimated number of EGU and non-EGU affected units in their jurisdiction as well as
the type of permit modifications that may be needed. Major modifications at existing sources are those
that would increase emissions by "significant" amounts and thus trigger Prevention of Significant
Deterioration (PSD) or Nonattainment New Source Review (NNSR) requirements. Large add-on controls,
like SCR or SNCR, may in some cases require PSD or NNSR permits. We anticipate that most control
installations will not result in significant emissions increases and thus will require only minor permit
modifications, if any. For purposes of this analysis, however, we conservatively assume that all
SCR/SNCR installations will require major permit modifications.
ES-3
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The estimated non-EGU NOx controls for the final FIP are divided into two groups. The SCR/SNCR group
are all non-EGU applications for these controls, except for compact SCR systems applied to reciprocating
internal combustion engines (RICE). The "other NOx controls" category represents mainly combustion
controls (e.g., LNB, layered combustion) or packaged post-combustion controls (e.g., NSCR, compact
SCR). There will be approximately three years available to achieve compliance with the final FIP, once
the final rule is issued. To allow for sufficient time for control design, fabrication and installation,
construction permits may need to be processed within the first 18 to 24 months.
Table ES-2 provides a breakdown of the number of affected units by state to identify the states that may
have larger numbers of permit modifications to process.3
Permitting backlogs are more likely in the states indicated in Table ES-2 with significant numbers of
affected units. The states with highlighted cells in Table ES-2 are those that may need to process many
major permit modifications (>20) or many minor modifications (>80) within the first two years following
rule finalization (this timeframe is expected in order to allow sufficient time for control installation). The
presence of an expedited permit review program should help alleviate a significant short-term increase
in state permitting review manpower needs in Indiana, Louisiana, and Texas.
Table ES-2. EGU and Non-EGU NOx Control Installations by State
State
(Expedited
Program?)
Estimated Non-EGU Control Installations
SCR/SNCR
Other NOx
Controls
Total
Arkansas (N)
2
32
34
California (Y)
6
7
13
Illinois (Y)
8
53
61
Indiana (Y)
12
41
53
Kentucky(Y)
2
46
48
Louisiana (Y)
25
174
199
Maryland (N)
0
2
2
Michigan (N)
16
45
61
Mississippi (N)
6
57
63
Missouri (N)
1
39
40
New Jersey (N)
10
1
11
New York (N)
19
11
30
Ohio (N)
14
96
110
Oklahoma (N)
72
63
135
Pennsylvania (N)
22
63
85
Texas (Y)
19
158
177
Utah (N)
1
5
6
3 U.S. EPA, Summary of Final Rule Applicability Criteria and Emissions Limits for Non-EGU Emissions Units, Assumed
Control Technologies for Meeting the Final Emissions Limits, and Estimated Emissions Units, Emissions Reductions,
and Costs. Technical Memorandum, March 15, 2023.
ES-4
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State
(Expedited
Program?)
Estimated Non-EGU Control Installations
SCR/SNCR
Other NOx
Controls
Total
Virginia (N)
8
29
37
West Virginia (N)
5
58
63
Totals
248
980
1,228
In addition, there may be states where permitting staff resources are stressed by a combination of EGU
and non-EGU permit modifications, although through 2026, the EGU permitting resulting from this rule
is expected to be relatively small. However, as indicated by the analysis in Section 4 that included
information from state permitting agencies, it is expected that at most the incremental permitting load
would be under 3 full-time staff per year in all affected states.
Skilled Labor and Other Supply Chain Constraints
Table ES-1 also provides an indication of whether supply chain issues have the potential to extend the
estimated time required for control installations. Potential sources of supply chain delays include:
competition for engineering, procurement, and construction (EPC) contractors (associated with large
controls, such as SCR or SNCR systems); equipment fabrication; skilled installation labor; local
construction labor (again for large control systems); and raw materials.
In the case of raw materials, sufficient availability of SCR catalyst material was identified as a concern
during discussions with control equipment vendors. This concern is mainly driven by a potentially
significant demand placed on catalyst manufacturers by the expected number of existing EGUs that will
elect to optimize their SCR systems by 2026. EPA expects that 229 EGU SCR optimizations will have been
conducted by the 2023 ozone season. In addition, as early as the 2026/2027 ozone seasons, EPA also
projects that a small number of EGUs will retrofit SCR (new system installs) on 2.5 - 8 GW
(approximately 16 EGUs assuming a 500 MW unit capacity).4 EGU SCR "optimizations" cover an array of
operational or physical alterations:
• Operational optimizations: these can be made without any physical alterations to the source or
SCR system or routine catalyst change-out schedules and include increasing maintenance,
optimizing reagent injection, or changing combustion conditions to assure that the exhaust is
meeting optimal temperatures for the SCR system (e.g., assuring that the EGU's dispatch
schedule maintains adequate exhaust temperature);
• Physical optimizations: these include a complete change-out of catalyst material or the addition
of another catalyst layer.
Depending on the number of EGU operators that elect physical optimizations to their SCR systems, a
short-term spike in demand for catalyst material could be a concern. However, EPA expects that very
few EGU operators will elect to conduct physical optimizations. Of the 229 EGUs noted earlier that could
4 U.S. EPA, "EGU NOx Mitigation Strategies Final Rule TSD," Technical Support Document (TSD) for the Final Federal
Good Neighbor Plan for the 2015 Ozone National Ambient Air Quality Standards, Docket ID No. EPA-HQ-OAR-2021-
0668, March 2023.
ES-5
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optimize their SCRs, 139 of them would have optimizations with emission reductions of 10 tons or less.
Also, 191 of the 229 EGUs that could optimize their SCRs (or 83%) are combined cycle and combustion
turbines. These natural gas-fired units generally require far less catalyst than coal-fired EGUs of the
same size and avoid many of the challenges created by fly ash, the presence of sulfur trioxide, and other
metals in the inlet to the SCR. In general, layers of catalysts can generally be swapped out during routine
maintenance shutdowns. While catalyst layers are sometimes changed on a rotating schedule, it would
not take significantly more time to swap out the entire amount of catalyst. We were unable to source
sufficient information from catalyst suppliers to gauge the significance of these new demands including
the potential length of any associated supply chain delay.
However, it is likely the case that any resulting increase in catalyst demand can be met via new
production and/or the recycling of catalyst material from retired EGUs equipped with SCR. It can be
noted that roughly 24 GW of EGUs with SCR are currently planning to retire (or have retired) between
Jan 2021 and May 2026.5 This would lower demand for catalyst, likely significantly more than any
increased demand from EGU SCR optimization or retrofits and the non-EGU new SCR installs addressed
in this report. In addition, the catalyst material from these retired units will be available for recycling
(reducing the need to source new raw materials).
Descriptions of where supply chain delays are expected, as well as their length, are provided below:
• No expected supply chain delay: for control installations in Table ES-1, where the "SCD timeline"
is the same as the "estimated install timeline," the control technology is expected to be readily
available or to have a short lead time for design and fabrication (e.g., compact SCR6 or NSCR
applied to RICE; LNB for furnaces in glass and glass products and reheat furnaces in iron and
steel). Further, skilled labor for control equipment design and installation is expected to be
available to meet the expected demand for services.
• Supply chain delay potential: additional time will likely be needed due to an identified supply
chain limitation. Situations where supply chain delays are expected are summarized below along
with an estimate of the length of delay:
o Cement and concrete product manufacturing, kilns installing SNCR for compliance: an
estimated 16 units may be competing for SNCR EPC contractors along with MWCs (61
units). Although 36 EGU SNCR optimization projects are expected, as stated previously,
these should mostly be able to be handled by in-house personnel. The pool of identified
US SNCR vendors is less than 10, and the number of these vendors that actually
conducts the design (including modeling), engineering, fabrication, and installation may
be no more than half of this (5 vendors). Based on discussions with control equipment
vendors, 5 SNCR installation projects per year is a representative annual capacity for
each vendor.
o MWC boilers: these 61 sources are estimated to achieve compliance by applying either
LNtm + SNCR or ASNCR. The pool of SNCR EPC contractors will likely be limited to those
with boiler expertise in the MWC sector. For the four installations of LNtm + SNCR, these
5 EPA, "Appendix A: Final Rule State Emission Budget Calculations and Engineering Analytics" (this is a spreadsheet
that is an appendix to the Ozone Transport Policy Analysis Final Rule TSD).
6 Note: compact SCR systems are the same in design as the SCRs applied to RICE in the final rule non-EGU cost
analysis.
ES-6
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all involve a single OEM for the original MWC unit (Covanta using their own proprietary
technology). Given the lack of competition for these facilities and no other supply chain
delays expected, it is assumed that Covanta can address these installations within the
required installation timeline.
The 57 expected MWC ASNCR and 16 cement kiln SNCR installations may be competing
for the same set of vendors. On-line information suggests that there are 3 to 5 vendors
capable of supplying ASNCR technology. The total number of EPC contractors for SNCR is
somewhat larger, but, if selected, we expect that those companies would still
subcontract to the more limited pool of experienced ASNCR equipment suppliers and
installers to complete a total of 73 SNCR or ASNCR installations.
Assuming that initial studies and permitting requires up to 12 months, there are two
years available before the compliance deadline of May 2026 for final design,
engineering, fabrication, and installation. Discussions with vendors suggest that full
capacity is on the order of 5 projects at any one time for most suppliers (five per year).
Therefore, 15 to 25 installations could be addressed by the estimated vendor pool per
year; or 30 to 50 units within 2 years. This leaves an additional 23 to 43 units that may
not be able to be addressed by May 2026 (which could be some combination of cement
kiln SNCR or MWC ASNCR installations). If the vendor pool is able to address 15 to 25
units per year, then approximately an additional 18 to 34 months (that is, 23 units/15
units/year x 12 months/year to 43 units/15 units/year x 12 months/year) might be
needed to address all affected units. This results in a total supply chain delay timeline of
35 to 58 months (17 to 24 months + 18 to 34 months) for cement installations of SNCR
and 35 to 57 months (17 to 23 months + 18 to 34 months, again showing the broadest
range of values) for ASNCR installation at MWCs. These timing estimates are based on
current vendor capacity, and these estimates will decline if such capacity increases to
meet the demand related to SNCR or ASNCR installations.
o Pipeline transportation of natural gas. RICE: application of layered combustion controls
to some RICE may involve emissions units that are over 60 years old. Comments
received by EPA indicate that while retrofit kits should be available for these RICE, these
installations may require skilled labor familiar with these units and the specialized
control kits to be applied. A key uncertainty is the number of RICE that might elect to
apply these combustion kits versus NSCR or another compliance option (e.g., engine
replacement or electrification). EPA's estimates in Table ES-1 above indicate that 394
RICE are estimated to apply layered combustion and 323 RICE are estimated to apply
either layered combustion or NSCR. This results in a likely quite high upper range
estimate of 717 units that could require specialized labor to address (technicians with
the skills to apply layered combustion control kits to older RICE). This is a highly
conservative estimate in that we do not have information on the number of older
engines (i.e., those approaching 60 years of age or older), and it is likely that a much
smaller set of units than the total number of units would undertake these types of
control installations. Therefore, this number should be considered an upper bound
ES-7
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reflective of the lack of data on engine age. As noted, we have also not attempted to
assess whether alternative compliance approaches such as replacement of these
engines with newer engines, or an increase in the necessary labor pool, could affect
these estimates. Industry comments that reflect actions taken nearly 20 years ago
suggest that a skilled labor pool is available to address at most 75 RICE per year.
However, as discussed in Section 5, information on the growth of available skilled labor
as the RICE population has increased over the last 20 years indicates the potential for
retrofit capacity of up to twice that amount (or, 150 RICE per year). Hence, depending
on the number of older RICE that industry elects to control with layered combustion,
potentially the full amount of time needed to complete installations on all affected units
is 717/150 = 4.8 years (58 months). For the portion of RICE estimated to be addressed
by either layered combustion or NSCR, if half of the RICE are addressed by layered
combustion, this results in a total estimate of 506 units. The total amount of time
required to address them by the available skilled labor pool is then 506/150 = 3.3 years
(40 months). Given that the total number of RICE that may require retrofits in response
to this final rule is estimated at about 905, we estimate that the maximum length of
control installation time for all sources in this category may potentially be as long as
905/150 = 72 months.
Note that these estimates do not include any consideration of delays that could occur
from review required by the Federal Energy Regulatory Commission (FERC). While this
concern was identified by commenters on the proposed rule, we were not able to
complete an evaluation of these claims. We note that capacity utilization of compressor
stations in the U.S. is about 40%; therefore, the ability to coordinate outages and work
with FERC may not present a substantial basis for assuming much if any delay in control
installation timing on this basis.
The estimated supply chain delay timeline is expected to range from 40 to 72 months.
However, we again emphasize that the upper-bound estimate is unlikely to occur in
reality. It assumes that all 717 identified engines are so old that they require specialized
labor, that no such engines could be replaced with newer engines due to their age, and
that there is no growth beyond 2022 in the pool of specialized labor in response to the
rule.
o Affected industries, boilers: For sources that require SCR for compliance, some level of
competition for EPC vendors is expected with EGUs that adopt SCR retrofits for
compliance. The amount of EGU capacity electing to conduct SCR retrofits is expected to
be relatively small (2.5 - 8 GW), and for purposes of this report, are expected to occur
during the 2023-2027 timeframe. Finally, SCR EPCs for the EGU sector are generally a
different group of vendors than those that serve the non-EGU sector.
The number of non-EGU boiler SCR installations estimated isn't exceptionally large as
indicated in Table ES-1; however, information gathered from vendor contacts indicates
continuing delays for equipment fabrication and certain imported components. Overall,
a supply chain delay of up to 12 months is likely to persist for affected boilers.
ES-8
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An additional supply chain delay concern is the availability of SCR catalyst material due
to overlapping demands with EGU SCR optimizations or retrofits. As addressed above,
the number of EGU SCR physical optimizations requiring additional catalyst material is
expected to be very small and to be completed by the 2023 ozone season. Recent and
ongoing EGU retirements with SCR systems will also reduce demand for catalyst and
also provide catalyst material for recycling. Considering only the additional 12 months of
supply chain delay related to equipment fabrication, the full amount of time needed for
SCR installation at an affected industry boiler could extend to 37 months.
Section 5 of this report provides information from a variety of indicators that offer some insight into the
potential for skilled labor and supply chain constraint concerns. We find that in most cases, skilled labor
and key materials in the supply chain have become more available than they were in 2020, and even
when compared to the concerns noted by commenters. However, the progress that has been made in
alleviating supply chain issues may need to be balanced with an understanding of the increased demand
for key materials and skilled labor that might result from a requirement to install NOx controls on both
EGU and non-EGU sources. Based on these indicators and input from control equipment vendors, access
to raw materials (e.g., sheet stainless steel) and key components (e.g., electrical controllers, pumps) has
either returned to near pre-pandemic levels or is expected to by early 2023.
Overall Conclusions
Based on the findings summarized above, the following types of affected units may experience difficulty
in compliance with the final rule by May 2026:
• Kilns in cement and concrete product manufacturing installing SNCR for compliance: due mainly
to limitations in the SNCR vendor pool and the overlapping needs for SNCR vendor support by
MWCs and EGUs, an additional 18 to 34 months beyond the "estimated install timeline" may be
needed. The supply chain delay timeline is therefore estimated to range from 35 to 58 months.
• RICE in pipeline transportation of natural gas applying layered combustion controls for
compliance: assuming the maximum number of engines that could apply this control are so old
that they need to be addressed by a limited pool of skilled labor, there is a potential that all
affected units will not be able to achieve compliance by May 2026. The supply chain delay
timeline is estimated to range from 40 to 72 months.
• Boilers in affected industries installing SCR for compliance may experience delays in equipment
fabrication. The supply chain delay timeline is 26 to 37 months.
• MWCs installing either LNtm + SNCR or ASNCR might be competing for vendors in a limited pool
of vendors with expertise in the municipal waste industry and with the application of ASNCR.
The supply chain delay timeline is estimated to be 35 to 57 months.
ES-9
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1. Introduction
EPA proposed a FIP to address regional ozone transport for the 2015 ozone NAAQS, published in the
Federal Register on April 6, 2022.7 This proposed rule included provisions to establish emission limits on
NOx emitted by certain industrial stationary sources in states that have been determined by EPA to be
impacting the ability of downwind states to meet the ozone NAAQS. The objective of this report is to
provide EPA with information on the time needed for non-EGU NOx emission sources in the specified
industries to install NOx controls that would enable these units to meet the emission limits.
In its proposed rule, EPA proposed that the non-EGU NOx controls should be in place in time for the
2026 ozone season and needed to understand issues that could prevent industries from meeting this
important deadline. Therefore, EPA solicited comment on issues related to the timing needed to install
these controls, issues of technical feasibility related to installing these controls in the specified
industries, and other related topics. This report draws on information provided by commenters in
response to the proposed rule as well as additional EPA technical reports, industry information, and
information obtained directly via communication with industry and state contacts. This report also
addresses updates to the non-EGU analysis for the final rule in terms of the number of units that are
likely to need to install pollution controls.
While EPA has prepared similar reports on the timing needed to install NOx control technologies on non-
EGU sources, the timing of this proposal introduced issues outside prior analyses and potentially beyond
the control of industry. The national and international supply chains have been disrupted first by the
Covid-19 pandemic that began in 2020 and then by the Russian invasion of Ukraine beginning in early
2022. These supply chain issues were frequently mentioned in comments received by EPA and have the
potential to impact the amount of time it will take for many non-EGU emission sources to install NOx
controls. Thus, this report addresses these issues and based on analysis of recent economic information,
attempts to put these issues in perspective to estimate any delays that supply chain issues may cause to
the processes needed to install NOx controls.
Section 2 of this document provides a brief background on each of the non-EGU industries and the
corresponding NOx emission sources that EPA has identified as industries and sources impacting the
ability of downwind states to meet the ozone NAAQS. Section 3 briefly describes the NOx control
technologies that EPA expects affected non-EGU sources will apply to meet the NOx emission limits in
the final rule. Section 4 summarizes the evaluation of the timing needed to install NOx controls on the
non-EGU emission sources in these industries, both on an individual basis as well as in combination with
the entirety of expected NOx controls for non-EGUs and EGUs combined that would be needed to
comply with the final rule. Section 5 discusses some of the potential supply chain issues and provides an
evaluation of the current economic factors impacting control installation. Finally, a summary of the
results from this report is presented in Section 6.
7 E PA, Federal Implementation Plan Addressing Regional Ozone Transport for the 2015 Ozone National Ambient Air
Quality Standard, Proposed Rule, 87FR20036, April 6, 2022.
1
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2. Affected Industries-—Emission Sources and Unique Issues
The affected non-EGU industries in the final rule for the FIP are as follows:
• Pipeline Transportation of Natural Gas;
• Cement and Concrete Product Manufacturing;
• Iron and Steel Mills and Ferroalloy Manufacturing;
• Glass and Glass Products Manufacturing;
• Basic Chemical Manufacturing;
• Petroleum and Coal Products Manufacturing;
• Pulp, Paper, and Paperboard Mills;
• Metal Ore Mining; and
• Solid Waste Incinerators and Combustors (indicated as Municipal Waste Combustors (MWCs).
A general overview of the affected non-EGU industries is provided below along with a description of the
primary sources of NOx emissions in these industries. The industries for which boilers are the only
affected sources are addressed as a group in a separate subsection.
2.1 Cement and Concrete Product Manufacturing
Within the cement and concrete product manufacturing industry, EPA's final rule would apply NOx
emission limits to kilns used in the production of clinker (all within North American Industry
Classification System (NAICS) code 32731x). Cement clinker is used in producing cement, and is
produced by grinding and mixing raw materials, and then heating (calcining) them at high temperatures
within a kiln. Clinker is made up of glass-hard, spherically shaped nodules that range from an eighth to
two inches in diameter. Limestone and other calcareous materials (calcium carbonate containing
substances, including gypsum), sand, clay, shale, and iron ore are key raw materials.8 Some amount of
recycled concrete and other materials may also be used in clinker production (e.g., fly ash, slag).
After the raw materials are ground and mixed, they are fed into a kiln. Clinker production is performed
using either a dry or wet process. In a wet process, the dry raw materials are mixed with water to form a
slurry. In a dry process, the materials are dried to less than one percent prior to pyroprocessing in the
kiln. For some plants using the dry process, an additional pre-calciner kiln is added before the main kiln
(calciner) to increase the overall thermal efficiency of the process. Both the pre-calciner and main kilns
can be fired on a variety of fuels (gas, liquid or solid) up to 2,700°F. After exiting the kiln, the clinker
passes through a clinker cooler, where some thermal energy is recovered to return to the process. The
clinker is then ground and mixed with other materials to produce finished cement.9
Essentially all the NOx emissions associated with cement manufacturing are attributed to the kilns due
to the high process temperatures. The specific types of kilns that produce NOx emissions and that may
be affected by the final rule are discussed below.
8 Shaped by Concrete, Sustainably Producing Concrete, website at https://howcementismade.com/.
9 Shaped by Concrete, Sustainably Producing Concrete, website at https://howcementismade.com/.
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Long Wet Kiln
Long wet kilns transform slurry to clinker. The slurry enters the kiln at room temperature with a
moisture content of 40%. Wet kilns must be 200 meters (m) long to allow enough time for evaporation.
Long wet kilns are not energy efficient because (1) the high moisture content of the slurry must be
evaporated by inefficient heat transfer and (2) the construction and maintenance of such a long kiln.
Wet kilns are uncommon today because of their required length and energy demands.10
Long Dry Kiln
Long dry kilns transform dry blended materials into clinker. Long dry kilns refer to a dry kiln without a
preheater or precalciner, hence why they must be longer. This process is more energy efficient than the
long wet kiln because (1) the low moisture content of the material allows for a shorter kiln and (2) less
heat transfer energy requirements (i.e., little evaporation necessary).11
Preheater Kiln
The preheater kiln preheats the materials before entry to the dry kiln to improve overall thermal
efficiency. The purpose is to minimize the latent heat requirement of the kiln. The dry powder concrete
material, limestone, and other materials enter at the top of the preheater. A series of four to six
cyclones keep the material suspended in the air. Hot gases, typically recycled from the clinker cooler,
travel up the preheater kiln and heat the cement materials passing down. This is an efficient means of
heat transfer. The preheater kiln decarbonizes 30-40% of the material before entering the dry kiln.12,13
Precalciner Kiln
A precalciner kiln preheats the materials before entry to the kiln to improve overall thermal efficiency.
The precalciner kiln has an additional burner beyond that used in the preheater kiln. Many designs
contain a preheater and precalciner in series for maximum operation efficiency. The materials exit the
precalciner kiln and enter the dry kiln at approximately 1,700°F. This additional process allows for 85-
95% decarbonization of the material before it enters the kiln.14 In a preheater/precalciner setup, fuel is
fired in the precalciner and rotary kiln. Conventional kilns only use fuel within the dry or wet kiln. This
unique design of preheater/precalciner systems allows for a shorter dry kiln, in comparison to
conventional kilns.
NOx Emission Limits for Affected Units in Cement and Concrete Products Manufacturing
The NOx emission limits in the final rule for affected kilns in concrete and cement products
manufacturing that have the potential to emit (PTE) 100 tons per year (tpy) of NOx are shown in Table 2-
1.
10 Understanding Cement, Manufacturing - the cement kiln, website at https://www.understanding-
cement.com/kiln. html.
11 Ibid.
12 Ibid.
13 Agico Cement, Precalciner, website at https://www.cementplantequipment.com/products/precalciner/.
14 Agico Cement, Precalciner, website at https://www.cementplantequipment.com/products/precalciner/.
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Table 2-1. NOx Emission Limits of Kilns from the Cement and Concrete Industry15
NOx Emissions Limit (lb
Kiln Type
NOx/ton of clinker)
Long Wet
4.0
Long Dry
3.0
Preheater
3.8
Precalciner
2.3
Preheater/Precalciner
2.8
2.2Glass and Glass Products Manufacturing
The glass and glass products manufacturing industry manufactures plate glass, glass bottles and
containers, automobile windshields, glass tubing, and insulation fiberglass. The NAICS code for glass and
glass products manufacturing is 3272xx.16 Raw materials used in glass production include silica, soda ash,
limestone, dolomite, and other chemicals.17
Glass products are classified by chemical composition and the type of glass product produced. Glass
products include flat glass, container glass, pressed and blown glass, and fiberglass. The manufacturing
of such glass occurs in four phases: (1) preparation of raw material, (2) melting in the furnace, (3)
forming, and (4) finishing. Phase 1 and 2, the preparation and melting of raw materials, is identical for all
glass products. The forming and finishing processes differ depending on the desired glass product.
Container glass and pressed/blown glass use pressing or blowing to form the desired product. Flat glass
is formed by float, drawing, or rolling processes.
Glass melting furnaces heat the raw materials at high temperatures before glass formation. The furnaces
have high energy demands and are the source of most NOx emissions in glass manufacturing. This is due
to the high process temperatures where nitrogen and oxygen react.18 NOx emissions from different
furnaces in the glass and glass product manufacturing industry are discussed below.
Container Glass Manufacturing Furnace
Container glass furnaces produce glass products that hold a certain form. Container glass is composed of
soda lime, clear or colored, and is pressed or blown into the shape of bottles, ampoules, etc. This type of
furnace is used in most glassmaking operations. These furnaces are designed to operate for 24 hours a
day and can perform large-scale production.19
15 U.S. EPA, Summary of Final Rule Applicability Criteria and Emissions Limits for Non-EGU Emissions Units,
Assumed Control Technologies for Meeting the Final Emissions Limits, and Estimated Emissions Units, Emissions
Reductions, and Costs. Technical Memorandum, March 15, 2023.
16 EPA, Office of Air and Radiation, "Non-EGU Sectors TSD," Draft Technical Support Document for the Proposed
Rule, Docket ID No. EPA-HQ-OAR-2021-0668, December 2021.
17 EPA, Glass Manufacturing Effluent Guidelines, website at https://www.epa.gov/eg/glass-manufacturing-effluent-
guidelines.
18 EPA, Office of Air and Radiation, "Non-EGU Sectors TSD," Draft Technical Support Document for the Proposed
Rule, Docket ID No. EPA-HQ-OAR-2021-0668, December 2021.
19 Glasstech Refractory, Container Glass Furnaces, website at http://www.glasstechrefractory.com/industrial-
solutions/container-glass-furnaces.
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Furnaces consist of three main parts, the melter, refiner, and regenerators or checkers. Most furnaces
use natural gas, but others can use oil, propane, or electricity. The glass melting furnace reaches
temperatures of 1,500 to 1,700°C (2,700 to 3,100°F). Furnaces range in size from 450 to > 1,400 square
feet of melter surface. The melter is a rectangular basin that melts raw materials and removes seeds,
i.e., fining. Furnaces contain three to seven natural gas burners above glass level to heat the glass at
very high temperatures. The burner ports also capture combustion emissions for further processing.
After it is melted, the glass passes through a water-cooled tunnel to the refiner. The refiner allows the
glass to slowly cool. Regenerators use recycled flue gas which saves energy.20
Pressed/Blown Glass Manufacturing Furnace or Fiberglass Manufacturing Furnace
In creating blown glass, or molded glass, gobs of melted glass from the glass furnace are placed in a
molding cavity where air is blown into the glass to expand it to a container shape with a neck. Once it is
shaped, the molded glass is now a "parison." This is referred to as the Blow & Blow Process, where
compressed air distinguishes the bottle neck finish and gives a uniform shape. During the Press & Blow
Process, used to create larger containers, a plunger is inserted into the glass and air is injected to form
the bottle shape.21
Glass fiber manufacturing is the high-temperature conversion of various raw materials (predominantly
borosilicate) into a homogeneous melt, followed by the fabrication of this melt into glass fibers. The two
basic types of glass fiber products—textile and wool—are manufactured by similar processes. The
primary component of glass fiber is sand, but it also includes varying quantities of feldspar, sodium
sulfate, anhydrous borax, boric acid, and many other materials.
Furnace designs vary, but most are large, shallow, and well-insulated vessels fired from above. Raw
materials are continuously added into the furnace where they slowly melt and mix into the molten glass.
The mixing of the molten glass and raw materials is facilitated by the natural convection of gases rising
through the molten glass. Some operators inject air into the bottom of the bed to facilitate convection.
Wool fiberglass insulation has five phases: (1) preparation of molten glass, (2) formation of fibers into a
wool fiberglass mat, (3) curing the binder-coated fiberglass mat, (4) cooling the mat, and (5) backing,
cutting, and packaging the insulation.
Flat Glass Manufacturing Furnace
The flat glass furnaces behave similarly to container and blown glass furnaces. Flat glass furnaces melt
fine-grained ingredients at 1,500°C. Melting, refining, and homogenizing can take up to 50 hours to
produce molten glass at 1,100°C, free from inclusions and bubbles. The melting process can be modified
by operators depending on the desired product.22
During the Float Bath process, molten glass from the furnace flows over a refractory spout onto a level
surface of molten tin. The molten glass starts at 1,100°C when leaving the furnace and cools to 600°C
20 Glass Packing Institute, Glass Furnace Operations, website at https://www.gpi.org/glass-furnace-operation.
21 Qorpak, Glass Bottle Manufacturing Process, website at
https://www.qorpak.com/pages/glassbottlemanufacturingprocess#:~:text=Blown%20Glass%20is%20also%20know
n,then%20known%20as%20a%20Parison.
22 Eurotherm, Flat Glass Manufacturing, website at https://www.eurotherm.com/us/glass-manufacture/flat-glass-
manufacturing/.
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during the float bath process. This gradual temperature cooling treatment relieves stresses in the glass
and is called "lehr". Too much stress and the glass will break beneath the cutter.
After the glass has cooled, the glass is inspected by machinery and workers to remove deformed or
cracked glass. Inspection technology allows more than 100 million measurements a second across the
ribbon, locating flaws the unaided eye would be unable to see.
NOx Emission Limits for Affected Units in Glass and Glass Products Manufacturing
The NOx emission limits on furnaces in glass and glass products manufacturing apply to furnaces that
have the potential to emit (PTE) 100 tons per year (tpy) of NOx. The final NOx emission limits for glass
manufacturing furnaces are shown in Table 2-2.
Table 2-2. Summary of Final NOx Control Requirements for Glass and Glass Product Industry23
NOx Emissions Limit
NOx Emission Source
(lb NOx/ton of glass produced)
Container Glass Furnace
4.0
Pressed/Blown Glass Furnace
4.0
Fiberglass Furnace
4.0
Flat Glass Furnace
7.0
2.3 Iron and Steel Mills and Ferroalloy Manufacturing
The iron and steel mills and ferroalloy manufacturing industry is primarily engaged in the production of
various steel products, including carbon, alloy, and stainless steels. It is identified by NAICS code 3311
(and related 5- and 6-digit NAICS codes) and encompasses various manufacturing processes. These
include:
(1) direct reduction of iron ore;
(2) manufacturing pig iron in molten or solid form;
(3) converting pig iron into steel;
(4) manufacturing ferroalloys;
(5) making steel;
(6) making steel and manufacturing shapes (e.g., bar, plate, rod, sheet, strip, wire); and,
(7) making steel and forming pipe and tube.24
Integrated iron and steel production is often misconstrued with electric arc furnace (EAF) steel
production. For integrated iron and steel production, a blast furnace (BF) transforms iron ore to molten
iron. A basic oxygen furnace (BOF) and molten "pig iron" together create molten steel. This process
generates more emissions than EAF steel production. In the BOF, high-purity oxygen oxidizes impurities
23 U.S. EPA, Summary of Final Rule Applicability Criteria and Emissions Limits for Non-EGU Emissions Units,
Assumed Control Technologies for Meeting the Final Emissions Limits, and Estimated Emissions Units, Emissions
Reductions, and Costs. Technical Memorandum, March 15, 2023.
24 EPA-HQ-OAR-2021-0668-0504. Comment submitted by Steel Manufacturers Association (SMA) and Specialty
Steel Industry of North America (SSINA).
6
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in the molten bath. Carbon is removed in the form of carbon monoxide (CO) and carbon dioxide
(C02).25,26 The molten steel is now the proper grade to be shaped and cooled.27
Unlike the BF/BOF process, the EAF process uses electrodes to melt the scrap metal. Oxy-fuel, including
natural gas burners, are used to supplement the EAF to obtain the necessary energy requirements.
During the refining process for EAF, impurities called "slag" conjoin at the top of the molten metal.
Molten slag is removed out a slag door by tipping the furnace, i.e., slagging. The final step is tapping
where molten steel is poured in a ladle. Usually, the steel will be further refined in a ladle metallurgy
station and/or argon oxygen decarburization. The steel is then cooled and formed into slabs.28
Ferroalloys are an alloy of iron with higher impurities of aluminum, magnesium, or silicon. Ferroalloy
processing is typically done in a submerged EAF, that, like EAF steel production, use carbon electrodes to
heat the scrap metal. A carbon source agent "coke" is typically added. The major alloys produced are
silicon alloys (ferrosilicon and calcium silicide), chromium alloys (high carbon ferrochromium in various
grades and ferrochrome-silicon), and manganese alloys (standard ferromanganese and
silicomanganese).29,30
In 2021, 16.39 million metric tons of raw steel was produced in the US, a substantial increase (42%) from
11.57 million metric tons in 2020.31 One hundred percent of steel can be repurposed without
compromising strength or quality, making it the most recycled material.32 However, the production of
iron and steel is energy intensive. In 2021, 6.34 megawatt (MW)-hours of energy per metric ton of raw
steel was consumed in the US.33
SC&A understands that Reheat furnaces are the only NOx sources at iron and steel mills that are subject
to this final rule.
Reheat Furnace
Reheat furnaces at BF/BOR within iron and steel mills heat cold steel to the necessary temperature
(~1200°F) before additional processing. The furnace is heated typically with natural gas, which emits
25 EPA, Office of Air and Radiation, Office of Air Quality Planning and Standards, "Available and Emerging
Technologies for Reducing Greenhouse Gas Emissions from the Iron and Steel Industry," September 2012.
26 EPA, Office of Air Quality Planning and Standards, "Alternative Control Techniques Document - NOx Emissions
from Iron and Steel Mills," September 1994.
27 EPA-HQ-OAR-2021-0668-0504. Comment submitted by Steel Manufacturers Association (SMA) and Specialty
Steel Industry of North America (SSINA).
28 EPA-HQ-OAR-2021-0668-0504. Comment submitted by Steel Manufacturers Association (SMA) and Specialty
Steel Industry of North America (SSINA).
29 EPA, Office of Air and Radiation, Office of Air Quality Planning and Standards, "Compilation of Air Pollutant
Emission Factors, Volume I: Stationary Point and Area Sources," AP-42, Fifth Edition, Chapter 12.4: Ferroalloy
Production, January 1995.
30 EPA, Ferroalloy Manufacturing Effluent Guidelines, website at https://www.epa.gov/eg/ferroalloy-
manufacturing-effluent-guidelines.
31 United States Steel, Energy Conservation, website at
https://www.ussteel.com/sustainability/environmental/energy-conservation.
32 American Iron and Steel Institute, Sustainability, website at http://www.recycle-steel.org/.
33 United States Steel, Energy Conservation, website at
https://www.ussteel.com/sustainability/environmental/energy-conservation.
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NOx. Emissions are typically vented through the building roof monitor. The next stage after the reheat
furnace is hot rolling.34
NOx Emission Limits for Affected Units in Iron and Steel Mills and Ferroalloy Manufacturing
For the iron and steel mills and ferroalloy manufacturing industry, the only sources included in the final
rule are reheat furnaces that have the potential to emit (PTE) 100 tons per year (tpy) of NOx and boilers
as affected sources. The affected reheat furnaces would be required to install LNB, with emission limits
established based on testing at the unit, as shown in Table 2-3. Boilers are discussed in Section 2.5.
Table 2-3. Summary of Final NOx Control Requirements for the Iron and Steel Industry35
NOx Emission
Source
NOx Emission Limit or Control
Efficiency
Expected
Controls
Best Estimate of
NOx Reduction
Reheat Furnace
Test and set limit based on
installation of Low NOx Burners
LNB
50%
2.4 Pipeline Transportation of Natural Gas
The Pipeline Transportation of Natural Gas industry falls under NAICS code 486210 and comprises
establishments primarily engaged in the pipeline transportation of natural gas from processing plants to
local distribution systems. This industry includes the storage of natural gas because the storage is usually
done by the pipeline establishment and because a pipeline is inherently a network in which all the nodes
are interdependent.
Natural gas compressor stations are located periodically along a transmission pipeline (e.g., every 50 -
100 miles). They function to raise the pressure of the gas to make up for losses due to pipeline friction
and changes in pipeline elevation.36 In 2017, there were reported to be 2,304 compressor stations
operating in the U.S. Detailed information was available for 1,197 (or 52% of the total), which indicated
that about 80% had more than one compressor unit and around 7 percent had more than 10
compressors. Typically, for compressor stations with multiple units, some of these will be back-up
compressors. Available information suggests that capacity utilization at natural gas compressor stations
is relatively modest. Assessments of capacity utilization indicate that around 25% of stations are utilized
at less than 40% of their capacity. Over 40% of stations are utilized at less than 80% of their capacity. In
certifications provided by the U.S. Federal Energy Regulatory Commission (FERC), pipeline operators are
required to retain sufficient compression capacity to meet demand on peak demand days (e.g., coldest
multi-day event for winter heating). Information from one pipeline operator indicated that their system
capacity utilization averaged 30%, and that average utilization in the U.S. was 40%.37
34 AMETEK Land, Reheat Furnace, website at https://www.ametek-
land.com/applications/steel/hotrollingreheatfurnace.
35 U.S. EPA, Summary of Final Rule Applicability Criteria and Emissions Limits for Non-EGU Emissions Units,
Assumed Control Technologies for Meeting the Final Emissions Limits, and Estimated Emissions Units, Emissions
Reductions, and Costs. Technical Memorandum, March 15, 2023.
36 National Energy Technology Labs (NETL), "Natural Gas Compressors and Processors - Overview and Potential
Impact on Power System Reliability," NETL-PUB-21531, July 2017.
37 EPA-HQ-OAR-2021-0668-0380. Comment submitted by TC Energy.
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The NOx sources addressed by the FIP are the prime movers of natural gas compressors: reciprocating
internal combustion engines (RICE). All the identified sources are fired by pipeline gas.38 RICE used at
compressor stations affected by the FIP are those >1,000 horsepower (hp). RICE are further
differentiated by three engine types:
• 2-stroke lean-burn
• 4-stroke lean-burn
• 4-stroke rich-burn
The final rule includes EPA's NOx emission limits on RICE in pipeline transportation of natural gas with
nameplate rating of >1,000 brake-horsepower (bhp). Table 2-4 provides the NOx emission limits for
these RICE.
Table 2-4. Proposed NOx Emission Limits for Natural Gas-Fired RICE in Pipeline Transportation of
Natural Gas39
Engine Type
Emissions Limit
(g/hp-hr)
4-Stroke Rich Burn
1.0
4-Stroke Lean Burn
1.5
2-Stroke Lean Burn
3.0
2.5 Boilers in the Iron and Steel Mills and Ferroalloy Manufacturing, Basic Chemical
Manufacturing, Petroleum and Coal Products Manufacturing, Pulp, Paper, and
Paperboard Mills, and Metal Ore Mining Industries
The non-EGU affected industries with boilers subject to the final rule are: Iron and Steel Mills and
Ferroalloy Manufacturing; Basic Chemical Manufacturing; Petroleum and Coal Products Manufacturing;
Pulp, Paper, and Paperboard Mills; and Metal Ore Mining. The final rule includes NOx emission limits on
boilers using fossil fuels n all affected industries. These fuels include coal, residual oil, distillate oil, and
natural gas. Natural gas units are the most common of the non-EGU boilers affected by the final rule.
The emission limits (30 day rolling average) for these boilers by fuel type can be seen in Table 2-5. These
limits apply to boilers used in the affected industries that have a design capacity of >100 MMBtu/hr.
38 National Energy Technology Labs (NETL), "Natural Gas Compressors and Processors - Overview and Potential
Impact on Power System Reliability," NETL-PUB-21531, July 2017. 77% of stations were fueled by natural gas, 17%
could operate on either electricity or natural gas, and 6% were powered solely by electricity.
39 U.S. EPA, Summary of Final Rule Applicability Criteria and Emissions Limits for Non-EGU Emissions Units,
Assumed Control Technologies for Meeting the Final Emissions Limits, and Estimated Emissions Units, Emissions
Reductions, and Costs. Technical Memorandum, March 15, 2023.
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Table 2-5. NOx Emission Limits for Non-EGU Affected Industry Boilers40
Emissions Limit
Unit Type
(lb NOx/MMBtu)
Coal
0.20
Residual Oil
0.20
Distillate Oil
0.12
Natural Gas
0.08
Basic chemical manufacturing includes both organic and inorganic chemicals manufacturing (i.e., NAICS
code 3251). Petroleum and coal products manufacturing includes NAICS code 3241). Pulp, paper, and
paperboard mills include newsprint mills (i.e., NAICS code 3221). Metal ore mining includes NAICS codes
2122. Additional descriptions for these affected industries are provided below.
Boilers utilize the combustion of fuel to produce steam. The hot steam is then employed for space and
water heating purposes or for power generation via steam-powered turbines. The three main types of
boilers are described below:41
• Firetube boilers. Hot gases produced by the combustion of fuel are used to heat water. The hot
gases are contained within metal tubes that run through a water bath. Heat transfer through
thermal conduction heats the water bath and produces steam. Typically, firetube boilers are
small, with capacity below 100 million British thermal units (MMBtu)/hr.
• Watertube boilers. Hot gases produced by fuel combustion heat the metal tubes containing
water. Typically, there are several tubes configured as a "wall." Watertube boilers vary in size
from less than 10 MMBtu/hrto 10,000 MMBtu/hr.
• Fuel-firing. Fuel is fed into a furnace and the high gas temperatures generated are used to heat
water. Fuel-firing boilers include stoker, cyclone, pulverized coal, and fluidized beds. Stokers
burn solid fuel and generate heat either as flame or as hot gas. Pulverized coal enters the burner
as fine particles. The combustion in the furnace produces hot gases. The ash (the unburned
fraction) exits in molten or solid form. Fluidized beds utilize an inert material to "suspend" the
fuel. The suspension allows for better mixing of the fuel and subsequently better combustion
and heat transfer to tubes.
A brief description of each of the affected industries with boilers is provided in the following sections.
Basic Chemical Manufacturing
The Basic Chemical Manufacturing industry transforms inorganic and organic materials into a desired
chemical product. The products include basic chemicals, coatings and adhesives, resins, cleaning
products, pesticides, and pharmaceuticals. The Basic Chemical Manufacturing industry is identified by
NAICS code 3251.
40 U.S. EPA, Summary of Final Rule Applicability Criteria and Emissions Limits for Non-EGU Emissions Units,
Assumed Control Technologies for Meeting the Final Emissions Limits, and Estimated Emissions Units, Emissions
Reductions, and Costs. Technical Memorandum, March 15, 2023.
41 Northeast States for Coordinated Air Use Management (NESCAUM), "Applicability and Feasibility of NOx, S02,
and PM Emissions Control Technologies for Industrial, Commercial, and Institutional (ICI) Boilers," January 2009.
Available at https://www.nescaum.org/documents/icj-bojjers-20081118-final.pdf.
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Boilers in the Basic Chemical Manufacturing industry play a crucial role. Boilers are used in producing
steam, boiling, and energy production. Steam is commonly used because it evenly distributes heat,
carries ample heat, and is an efficient energy transfer process. Steam allows for easy adjustments of
temperature and pressure, as well as slowly cooling or heating a chemical reactor.
Some processes in the Basic Chemical Manufacturing industry that use boilers are as follows:
• Boilers power exhaust fans to vent fumes during production.
• Boilers heat and cool reactors with steam or water.
• Waste heat boilers reuse heat energy to reduce waste.
• Boilers produce the electricity needed to run the plant.
Petroleum and Coal Products Manufacturing
The Petroleum and Coal Products Manufacturing industry transforms crude petroleum and coal into
desired products. Some of these products include gasoline, diesel fuel, asphalt, lubricating oils, paraffin
waxes, and transmission fluids. This industry is dominated by petroleum refineries. The Petroleum and
Coal Products Manufacturing industry is identified by NAICS code 3241.
Crude oil is superheated in a furnace and turns from a liquid to a gas. The superheated gas is transferred
to the bottom of the distillation tower. The oil begins to cool and return to a liquid in the tower. Using
stacking trays, heavier oils will remain at the bottom of the distillation tower while lighter oils will raise
to the top of the tower. This process discriminates crude oil by boiling point, density, and grade. Light
oils have less than 10 elements of carbon and low boiling points under 120°C. These oils become
propane and natural gas, for example. Lighter oils are more valuable and require less processing. Heavy
oils have greater than 30 elements of carbon and higher boiling points over 300°C. These oils become
residual oil, asphalt, or tar. Oil refineries have cracking units that transform unusable heavy oils into
lighter oils. This is accomplished by catalysts breaking long chain carbon bonds into shorter
hydrocarbons. These lighter fuels are now more valuable to the industry.
Boilers play a crucial role in the Petroleum and Coal Products Manufacturing industry. Their main
purpose is to heat oil for distillation. Boilers heat the crude oil in the furnace, distillation tower, and
cracking unit to promote the separation of oil grades. Refineries typically use water tube and fire tube
boilers.
Pulp. Paper, and Paperboard Mills
Paper production begins with harvesting trees. Next, the bark is removed, and the wood chips are
placed in a digester to remove their lignin content. This process is very energy intensive, using half the
total energy demand of an entire pulp and paper plant in this one step.42 What remains is "pulp," which
is then filtered and bleached, and then additives are added into the pulp. To process pulp into paper, the
pulp is squeezed through rollers to form sheets. This also removes most additional water content in the
paper. The paper is then rolled into reels for any further processing, such as cutting, color, or strength
additives. The Pulp, Paper, and Paperboard Mill industry is identified by NAICS code 3221.
Boilers play a crucial role in the pulp and paper industry. Boilers are primarily used in this industry in
producing steam, boiling, and energy production. Steam is commonly used because it evenly distributes
42 Energy Link, Top 4 Energy Consumers in the Paper Manufacturing Industry, website at
https://goenergylink.com/blog/paper-manufacturing-industry-the-top-4-energy-consumers/.
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heat, promotes uniformity and increased strength in the final paper product. Steam is also used because
it carries ample heat and is an efficient energy transfer process. Steam allows for easy adjustments of
temperature and pressure, depending on the grade of paper needed.
Some processes in the pulp and paper industry that use boilers are as follows:
• In the digester, tree scapings are boiled to remove lignin and make pulp.
• Steam uniformly heats the paper rolls during the rolling process.
• Steam dries the paper before rolling.
• Boilers are used in the reuse and purification of water.
• Boilers produce the electricity needed to run the plant.
Metal Ore Mining Industry
The metal ore mining industry extracts desired metals to produce a product. The most mined metals
include iron and copper. Other examples include nickel, rare earth metals, cobalt, manganite, and
uranium ores. Metals are mined for renewable energy, electronic wiring, steel production, and batteries.
The Metal Ore Mining Industry is identified by NAICS code 2122.
Metal ore mines can be above or below ground. Metals originate in rock with some ores containing less
than a percent of the desired metal. As a result, massive amounts of rock must be extracted to meet
demand. The Metal Ore Mining Industry requires heavy machinery and explosives to crush and drill
through rock. A meta-analysis on energy consumption was performed on the gold, copper, nickel,
lithium, and iron mining industries. Copper is the most energy intensive and 46% of the energy
consumed is diesel, mainly for off-grid mobile equipment.43
After the rock is extracted, it undergoes crushing and grinding, a concentrator to remove impurities, and
metals recovery.44 Although most of the energy consumption in the mining industry is off grid, boilers
are used as a power source and/or output steam to produce heat energy. Boilers have been used in ore
mining and beneficiation, or the removal process of gangue minerals. Metals recovery requires heat and
steam and is a process in the metal ore mining industry that can utilize boilers.45
2.6 Municipal Waste Combustors
Municipal waste combustion involves the burning of garbage and other nonhazardous solids, collectively
referred to as municipal solid waste (MSW), to generate electric power.46 The NAICS code for Solid
Waste Incinerators and Combustors is 562213. MSW is a mixture of energy-rich materials such as paper,
plastics, yard waste, and products made from wood. For every 100 pounds of MSW in the United States,
about 85 pounds can be burned as fuel to generate electricity. Waste-to-energy plants can reduce 2,000
43 Allen, M. Mining Energy Consumption 2021, Engeco.
44 EPA, Explore a Metal Mine that Reports to the TRI Program, website at: https://www.epa.gov/toxics-release-
inventory-tri-program/explore-metal-mine-reports-tri-program.
45 DHB Boiler, Mining, website at: https://dhbboiler.com/mining/.
46 EPA, AP-42 Compilation of Air Pollutant Emissions Factors, Section 2.1 Refuse Combustion, October 1996,
available at https://www3.epa.gov/ttnchiel/ap42/ch02/final/c02s01.pdf.
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pounds of garbage to ash weighing about 300 pounds to 600 pounds, and they reduce the volume of
waste by about 87%.47
Municipal waste combustors (MWC) are intended to reduce the volume of MSW through combustion of
that solid waste. MSW is a fuel that tends to be a heterogeneous mixture of heavy and light materials of
various combustibility. Most MWCs are designed to recover some of the heat generated from the MSW
combustion process through heat absorption by radiant and convective water-cooled and steam-cooled
tubing surfaces. MWCs may incorporate the steam generator within the MWC as an integral
component, or the steam generator is a separate entity acting as a waste heat recovery device attached
to the MWC. There are many designs and configurations of MWC units, often depending upon the
intended volume of MSW throughput, characteristics of the design "municipal waste fuel", and the
experience and preferences of the owner/operator and engineering/design organization.48
Nitrogen oxides in the MWCs are formed primarily during combustion through the oxidation of
nitrogen-containing compounds in the waste at relatively low temperatures (<1,090°C or 2,000°F), and
negligibly through the fixation of atmospheric nitrogen, which occurs at much higher temperatures.
Because of the kind of fuel MWCs use and the relatively low temperatures at which they operate, 70-
80% of NOx formed in MSW incineration is associated with nitrogen in the MSW.49
There are different types of waste-to-energy systems or technologies. The most common type used in
the United States is the mass-burn system, where unprocessed MSW is burned in a large incinerator
with a boiler and a generator for producing electricity. Another less common type of system processes
MSW to remove most of incombustible materials to produce refuse-derived fuel (RDF).50 There is also a
smaller and more portable type of system known as modular systems.
Mass Burn Facilities
At an MSW combustion facility, MSW is unloaded from collection trucks and placed in a trash storage
bunker. An overhead crane sorts the waste and then lifts it into a combustion chamber to be burned.
The heat released from burning converts water to steam, which is then sent to a turbine generator to
produce electricity.
The remaining ash is collected and taken to a landfill where a high-efficiency baghouse filtering system
captures particulates. As the gas stream travels through these filters, more than 99 percent of PM is
removed. Captured fly ash particles fall into hoppers (funnel-shaped receptacles) and are transported by
an enclosed conveyor system to the ash discharger. They are then wetted to prevent dust and mixed
with the bottom ash from the grate. The facility transports the ash residue to an enclosed building
where it is loaded into covered, leak-proof trucks and taken to a landfill designed to protect against
47 U.S. Energy Information Administration (EIA), Biomass explained Waste-to-energy (Municipal Solid Waste),
website at https://www.eia.gov/energyexplained/biomass/waste-to-energy-in-
depth.php#:~:text=Waste%2Dto%2Denergy%20plants%20burn,and%20products%20made%20from%20wood.
48 Ozone Transport Commission Stationary, Area Sources Committee, "Municipal Waste Combustor Workgroup
Report," April 2022.
49 EPA, AP-42 Compilation of Air Pollutant Emissions Factors, Section 2.1 Refuse Combustion, October 1996,
available at https://www3.epa.gov/ttnchiel/ap42/ch02/final/c02s01.pdf.
50 U.S. Energy Information Administration (EIA), Biomass explained Waste-to-energy (Municipal Solid Waste),
website at https://www.eia.gov/energyexplained/biomass/waste-to-energy-in-
depth.php#:~:text=Waste%2Dto%2Denergy%20plants%20burn,and%20products%20made%20from%20wood.
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groundwater contamination. Ash residue from the furnace can be processed for removal of recyclable
scrap metals.51
There are 2 major sub-categories of mass burn MWCs—mass burn waterwall MWCs and rotary
waterwall MWCs, discussed below.
Mass Burn Waterwall MWCs
Mass burn waterwall MWCs have lower furnace primary combustion zones made of waterwall tubes for
heat transfer in the combustion zone. For mass burn waterwall MWCs, the MSW fuel is typically loaded
into charging hoppers and fed to hydraulic rams that push the MSW fuel onto the stoker grate in the
furnace for combustion. Most stokers utilize a reciprocating grate action, utilizing either forward or
reverse acting grate movement, which moves the combusting MSW fuel across the furnace to allow
time for drying and complete combustion. Generally, there will be a large volume of fuel at the front end
of the grate that burns down to a small amount of ash at the back of the grate. The grate may have a
slightly downward angle from fuel introduction to the ash drop off to help move the MSW fuel through
the furnace. The reciprocating action of the grates also tends to agitate the MSW fuel, generally causing
the MSW fuel to roll and mix. This agitation helps ensure all the MSW fuel is exposed to the high
temperatures in the bed of combusting MSW fuel and helps provide contact with combustion air,
resulting in more complete combustion of the MSW fuel as it travels across the furnace. Combustion ash
that does not leave the stoker grate as fly ash is dropped off at the end of the stoker through a discharge
chute for disposal or further processing.
Mass burn waterwall MWCs may also incorporate auxiliary fuel burners to help bring the MWCs to
temperature to begin combustion of the MSW fuel, to supplement the heat input necessary to attain
the steam generator output rating with varying MSW fuel quality, or to ensure sufficient flue gas
temperatures are attained for proper emissions control.
Combustion air is generally introduced to the combustion zone utilizing pressurized air as underfire
(primary) air or overfire (secondary) air. At least one proprietary design, however, splits the overfire air
into two distinct zones, effectively creating three combustion air introduction zones.
Underfire air is introduced under the stoker grate, sometimes through a series of plenums that allow for
underfire air introduced to various portions of the grate area to be controlled to enhance combustion
based on MSW fuel characteristics. The underfire air travels from the plenums to the combustion zone
through holes in the grate to assure good distribution across the grate. Underfire air systems are
generally designed to be able to provide up to 70% of the total combustion air requirement, with typical
underfire air operating requirements utilizing 50% to 60% of the total combustion air.
Overfire air is introduced into the furnace above the grate level through multiple ports in the furnace
walls. The primary purpose of the overfire air is to provide the amount of air necessary to mix the
furnace gasses leaving the grate combustion zone and provide the oxygen required to complete the
combustion process. Proper control of the overfire air may also be utilized to provide some control of
51 EPA, Energy Recovery from the Combustion of Municipal Solid Waste (MSW), website at
https://www.epa.gov/smm/energy-recovery-combustion-municipal-solid-waste-msw.
52 Ozone Transport Commission Stationary, Area Sources Committee, "Municipal Waste Combustor Workgroup
Report," April 2022.
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the NOx emission rate leaving the high temperature zone of the furnace. The amount of overfire air is
typically 40% to 50% of the total required combustion air and is somewhat dependent upon MSW fuel
quality and NOx emission control requirements.
Rotary Waterwall MWCs
A rotary waterwall MWC utilizes a water-cooled, tilted, rotating cylindrical combustion chamber. The
MSW fuel is typically loaded into charging hoppers and fed to hydraulic rams that push the MSW fuel
into the slowly rotating combustion chamber. The rotation of the tilted cylindrical combustion chamber
causes the MSW fuel to tumble and advance the length of the cylindrical combustion chamber, ensuring
all the MSW fuel is exposed to high temperatures and combustion air for a sufficient amount of time for
drying and complete combustion of the MSW fuel. Combustion ash that does not leave the rotary
burner as fly ash is dropped off at the end of the rotary burner through a discharge chute for disposal or
further processing.
Rotary burner MWCs may also incorporate auxiliary fuel burners to help bring the MWCs to
temperature to begin combustion of the MSW fuel, to supplement the heat input necessary to attain
the steam generator output rating with varying MSW fuel quality, or to ensure sufficient flue gas
temperatures are attained for proper emissions control.
Combustion air for rotary burner MWCs is introduced to the rotating combustion chamber by a
pressurized plenum surrounding the rotating combustion chamber. The combustion air enters the
rotating combustion chamber through the walls of the chamber, generally through spaces between
waterwall tubes. Underfire air is introduced at the bottom of the rotating combustion chamber and
through the bed of combusting MSW. Overfire air is introduced into the rotating combustion chamber
over the bed of combusting MSW. Dampers are utilized to proportion the total air flow and control the
overfire air/underfire air split. Because the waterwall tubes form the floor of the combustion zone and
effectively remove heat from that surface, peak combustion temperatures may tend to be lower than
experienced with other MWC designs, helping reduce the NOx emissions relative to those other MWC
designs. Also, as the water-cooled surfaces require lower amounts of initial combustion zone excess air
for cooling of combustor components, lower amounts of total excess air may be required for many
rotary burner MWCs compared to some other MWC designs. The reduced excess air requirements may
also help to reduce base NOx emissions relative to other MWC designs.
Refuse-Derived Fuel Systems
Refuse-Derived Fuel (RDF) systems use mechanical methods to shred incoming MSW, separate out non-
combustible materials, and produce a combustible mixture that is suitable as a fuel in a dedicated
furnace or as a supplemental fuel in a conventional boiler system.53
In an RDF system, the following processes are performed:54
• Crushing process: Refuse is crushed to the appropriate size for drying.
• Drying process: High-temperature blast dries and deodorizes refuse.
53 EPA, Energy Recovery from the Combustion of Municipal Solid Waste (MSW), website at
https://www.epa.gov/smm/energy-recovery-combustion-municipal-solid-waste-msw.
54 Kawasaki Heavy Industries, Refuse-derived Fuel (RDF) Manufacturing Plant, website at
https://global.kawasaki.com/en/industrial_equipment/environment_recycling/waste/rdf.html.
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• Sorting and Crushing process: Unsuitable substances for fuel such as iron and stone are
removed. Refuse is crushed to the appropriate size for forming RDF.
• Solidifying process: Additive is supplied to prevent corruption. Substances are formed to
produce high-density and high-strength RDF that is suitable for transportation, storage, and
combustion.
Modular System
Modular Systems burn unprocessed, mixed MSW. They differ from mass burn facilities in that they are
much smaller and are portable. They can be moved from site to site.55 One of the most common types of
modular system is the starved air or controlled air type combustor which incorporates two combustion
chambers. Air is supplied to the primary chamber at sub-stoichiometric levels and the resultant
incomplete combustion products (CO and organic compounds) pass into the secondary combustion
chamber where combustion is completed with the additional air. Another modular system design is the
excess air combustor which, like the starved air combustor, also consists of two chambers but is
functionally similar to mass burn units in its use of excess air in the primary chamber.56
NOx Emission Limits for Affected Units in Municipal Waste Combustion
Table 2-6 summarizes the NOx emission limits for large MWCs, which are defined as incinerators that
combust greater than 250 tons per day of municipal solid waste. Note that both the 24-hour average
limit and the 30-day average limit must be met.
Table 2-6. NOx Emission Limits for Large MWCs57
Unit Type
Emissions Limit
(parts per million by volume, dry basis NOx [ppmvd])
Combustors or Incinerators
110 ppmvd on a 24-hour averaging period and
105 ppmvd on a 30-day averaging period
55 EPA, Energy Recovery from the Combustion of Municipal Solid Waste (MSW), website at
https://www.epa.gov/smm/energy-recovery-combustion-municipal-solid-waste-msw.
56 EPA, AP-42 Compilation of Air Pollutant Emissions Factors, Section 2.1 Refuse Combustion, October 1996,
available at https://www3.epa.gov/ttnchiel/ap42/ch02/final/c02s01.pdf.
57 U.S. EPA, Summary of Final Rule Applicability Criteria and Emissions Limits for Non-EGU Emissions Units,
Assumed Control Technologies for Meeting the Final Emissions Limits, and Estimated Emissions Units, Emissions
Reductions, and Costs. Technical Memorandum, March 15, 2023.
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3. Non-EGU NOx Emission Controls
This section provides brief descriptions of the NOx control technologies that SC&A estimates affected
non-EGU sources may apply to meet the emission limits of the final rule. It is not meant to cover all
possible NOx control technologies that could achieve the NOx emission limits for the sources affected by
the final rule.
3.1 External Combustion Controls
Low NOx Burners
Low NOx burners (LNB) are designed to control combustion fuel and air mixing in such a way as to create
larger and more branched flames, which reduce peak flame temperatures. By lowering peak flame
temperatures, thermal NOx formation is reduced. The initial stage of combustion occurs in a fuel rich,
oxygen deficient zone where NOx is formed. A reducing atmosphere follows where hydrocarbons are
formed which react with the already formed NOx. In the third stage of combustion, internal air staging
(additional air) completes the combustion but may result in additional NOx formation. This however can
be minimized by completing the combustion in an air lean environment.58
LNBs can be applied to a variety of industrial NOx emission sources including furnaces, some kilns, and
boilers, but can vary in the level of NOx control achieved across such sources. In the iron and steel
industry, reheat furnaces show a relatively high NOx reduction potential of 66% with the application of
LNB. In contrast, LNB technology only reduces NOx emissions from indirect-fired cement kilns by 25%.
LNB can reduce NOx emissions by 50% NOx from industrial boilers, regardless of fuel type.59
Flue Gas Recirculation
In FGR, cooled flue gas and ambient air are mixed to become the combustion air and are reintroduced to
the system by fans and flues. The mixing reduces the oxygen content of the combustion air supply and
lowers the combustion temperature. FGR is feasible if there is no minimum operation temperature
and/or oxygen requirement for the boiler as FGR lowers the temperature range and oxygen levels in the
boiler. FGR may affect fan capacity, furnace pressure, burner pressure drop, and turndown stability, so it
may not be feasible for boilers where these are critical parameters. FGR is commonly implemented in
conjunction with LNB.60
Covanta Patented Low NOx Technology
Covanta's patented Low NOx Technology (LNtm) is a proprietary combustion technology developed by
Covanta to reduce NOx emissions from MSW combustion. LNtm encompasses a process that modifies
combustion in a furnace by diverting a portion of the secondary emissions and then injecting it at a
higher elevation in the furnace. This system optimizes combustion and reduces NOx emissions by
distributing combustion air between the primary, secondary, and tertiary levels and providing additional
fuel/air staging for NOx control while still providing enough air for complete combustion. This system
has been installed on many MWC units operated by Covanta. It has been shown that this system can
achieve an annual NOx emission limit of 90 ppm and a daily NOx emission limit of 110 ppm. However,
58 Goes Heating Systems, Low NOx Burners, website at https://goesheatingsystems.com/low-nox-burners/.
59 EPA, Office of Air and Radiation, "Non-EGU Sectors TSD," Draft Technical Support Document for the Proposed
Rule, Docket ID No. EPA-HQ-OAR-2021-0668, December 2021.
60 EPA, Menu of Control Measures for NAAQS Implementation, menuofcontrolmeasures.pdf, website at
https://www.epa.gov/sites/default/files/2016-02/documents/menuofcontrolmeasures.pdf.
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the proprietary aspects of the technology may make it unlikely that it could be applied to non-Covanta
MWCs. Additionally, not all Covanta MWC configurations may be able to incorporate the components
needed for LNtm. This technology is typically used in conjunction with selective non-catalytic reduction
(SNCR)61 and, for the sources for which LNtm is the control technology applied in the final rule cost
analysis, it is always paired with SNCR.
Selective Catalytic Reduction
Selective catalytic reduction (SCR) is the most widely used post-combustion NOx reduction technology.
SCR uses a reducing agent to convert NOx to desirable gases. The reductant is typically ammonia or
urea. In ammonia reduction, NOx in the flue gas is injected with aqueous ammonia onto a catalyst that
speeds up the reaction. After completion, NOx has been converted to nitrogen gas and water. Urea
reduction operates similarly, but the products are carbon dioxide, nitrogen gas, and water.
SCR requires regular maintenance to perform properly, as it is a temperature-dependent system, ideally
operating between 550-800°F.62 When temperatures are out of this range, "ammonia slip" occurs.
Ammonia slip is a major issue in SCR operation in that ammonia will pass through the SCR unreacted.
Ammonia gas must be properly distributed in the chamber for the needed chemical reactions to occur.
Due to the harsh nature of flue gases and ammonia, SCR equipment has a finite life. This is especially
true for the catalyst. The catalyst pores can get clogged and contaminated by soot particles depending
on the effectiveness of large particle ash filters, often used with SCR that are applied to coal-fired units If
catalyst pores become clogged and contaminated by soot particles, the operator may need to replace
the catalyst.
SCR is a dominant NOx control technology due to its high NOx removal efficiency. SCR can typically
achieve greater than 80% NOx reduction. SCR has been successfully used on boilers, annealing furnaces,
four stroke lean burn spark ignition engines, and other equipment. SCR may not be feasible if the flue
gas temperature is not within an acceptable range, in exhaust environments that could poison the
catalyst (e.g., acid gases; alkali metals, such as sodium or potassium), or in operations with limited space
that may be insufficient for SCR installation. For the external combustion sources, SCR is EPA's applied
control technology for some of the affected boilers in the final rule cost analysis.
Selective Non-Catalvtic Reduction
SNCR is another post-combustion technology. The major difference between SCR and SNCR is that SNCR
does not use a catalyst. The SNCR procedure is like SCR in that ammonia or urea is injected into the flue
gas to convert NOx to clean gas. The absence of a catalyst allows for higher flue gas temperatures
between 1,400 to 1,600°F. SNCR has the potential to reduce NOx emissions by 35 to 75%.63 SNCR has
many of the same disadvantages as SCR. SNCR is prone to ammonia slip, installation spacing is a
concern, and the flue gas temperature must be in the proper range. In the final rule cost analysis, SNCR
is the control EPA's technology applied at affected cement kilns and in combination with LNtm at some
affected MSW combustors and incinerators.
61 Ozone Transport Commission Stationary, Area Sources Committee, "Municipal Waste Combustor Workgroup
Report," April 2022.
62 EPA, Office of Air and Radiation, "Non-EGU Sectors TSD," Draft Technical Support Document for the Proposed
Rule, Docket ID No. EPA-HQ-OAR-2021-0668, December 2021.
63 Ibid.
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Advanced SNCR
Advanced selective non-catalytic reduction (ASNCR) can be used to upgrade existing SNCR installations
or can be used as a new retrofit technology for MWCs. As with SNCR, ASNCR involves the injection of
reagents into the proper temperature zones of a furnace to reduce the NOx concentration in the flue
gas. The main difference between ASNCR and SNCR is that ASNCR uses advanced furnace temperature
monitoring that provides near real-time feedback on the temperature profile of the furnace. The ASNCR
system then automatically adjusts the individual injector flow rates to optimize the NOx emission
reductions. This helps to reduce the magnitude of NOx spikes that occur in MWC furnaces due to
combusting a mixture of fuels while also keeping a low level of ammonia slip. ANSCR can reduce NOx
emissions by about 70% and should be applicable to many MWCs as a retrofit control technology,
although the furnace configuration and other factors could limit the NOx reduction potential.64 In the
final rule cost analysis, ASNCR is the control technology that is applied to a majority of the affected MSW
combustors and incinerators.
3.2 Internal Combustion Controls for Engines
Layered Combustion
Layered combustion (LC) which is used for 2-stroke lean burn engines consists of multiple technologies:
• High-pressure fuel injection
• Turbocharging
• Precombustion chamber
• Cylinder head modifications
The estimated range of NOx reductions from the use of LC technologies is 60 - 90%.65 For 2-stroke
engines, the final rule contains an emissions limit of 3.0 g NOx/hp-hr, which should be achievable using
LC controls. In the final rule cost analysis, LC is the applied control technology for 2-stroke lean burn
engines.
Non-Selective Catalytic Reduction
For rich burn RICE (excess oxygen less than 0.5% in the exhaust), non-selective catalytic reduction
(NSCR) is the commonly accepted emissions control, not only for NOx, but for CO and volatile organic
compounds (VOC) as well. NSCR is often referred to as a 3-way catalyst control, since it addresses all 3
pollutants (CO and VOC are oxidized, while NOx is reduced to nitrogen). It is also used in gasoline
vehicles ("catalytic converters"). Automatic air to fuel control systems are needed to maintain exhaust
oxygen levels below 0.5 percent. NOx control efficiencies are reported to range from 90 - 98 percent.66
NSCR is the applied control technology for 4-stroke rich burn engines in the final rule cost analysis.
64 Ozone Transport Commission Stationary, Area Sources Committee, "Municipal Waste Combustor Workgroup
Report," April 2022.
65 EPA, Office of Air and Radiation, "Non-EGU Sectors TSD," Draft Technical Support Document for the Proposed
Rule, Docket ID No. EPA-HQ-OAR-2021-0668, December 2021.
66 EPA, Office of Air Quality Planning and Standards, EPA-453/R-93-032 Alternative Control Techniques Document -
NOx Emissions from Stationary Reciprocating Internal Combustion Engines, July 1993, available at
https://www3.epa.gov/airquality/ctg_act/199307_nox_epa453_r-93-032_internal_combustion_engines.pdf.
19
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Selective Catalytic Reduction
For lean burn RICE and gas turbines, SCR might be considered in cases where LC controls are not able to
meet the desired NOx emission limits. As of 2014, SCR application on sources in the pipeline
transportation of natural gas industry was very limited, especially as a retrofit; however, some new four-
stroke lean-burn engines had been sited with SCR.67 Just as with external combustion sources described
above, SCR involves the injection of a reagent (ammonia or urea) to "selectively" reduce NOx across a
catalyst bed. The application of SCR is more challenging for RICE due to the need for the exhaust gas to
be within an effective operating range (480 - 800 Fahrenheit) and fluctuations in N0/N02 ratios in the
exhaust (which affect the required reagent feed rate). Applications on engines with variable power loads
is particularly challenging, and the use of a continuous emissions monitor (CEM) may be required for
precise reagent control. SCR is the applied control technology for 4-stroke lean burn engines in the final
rule cost analysis.
67 Interstate Natural Gas Association of America (INGAA), "Availability and Limitations of NOx Emission Control
Resources for Natural Gas-Fired Prime Movers Used in the Interstate Natural Gas Transmission Industry," prepared
by Innovative Environmental Solutions and Optimized Technical Solutions, INGAA Foundation Final Report No.
2014.03, July 2014.
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4. Timing to Install Controls
4.1 Phases Common to Control Installations
This section discusses steps or work elements required to install NOx control technologies for non-EGUs
to attain compliance with this rule.
In general, installation of NOx control equipment for regulatory compliance occurs in two major distinct
phases: the analysis phase culminating in a decision, typically designated as pre-award/preconstruction
activities, and the implementation phase of an engineering, procurement, and construction (EPC)
contract award. Considering that design, construction materials, labor to install controls, and
commissioning can account for a large portion of the project's total capital cost, corporate management
often expends significant effort upfront analyzing options for regulatory compliance to minimize
financial risk before awarding a contract for materials and services.
The path to contract award contains several work elements. Figures 4-1 and 4-2 illustrate general
timelines for control installation, showing these work elements. Timelines for some of the common
steps for NOx control installation were adapted from an EPA technical memorandum.68 A final step for
obtaining operating permits was also added for situations where those are required (some states have a
combined process for permits to construct and operate, while in others, these are two separate
processes). The timeline for large add-on controls such as SNCR or SCR to large industrial sources
(including large MWCs) is shown in Figure 4-1 while the general timeline addressing combustion controls
and small add-on controls, such as compact SCR or NSCR applied to RICE, is shown in Figure 4-2. The
longer general timeline indicated for large add-on controls reflects the likely challenges in engineering
and fabrication (including site-specific design and construction challenges).
68 B. Lange, Eastern Research Group, "NOx APCD Installation Times Early Findings," prepared for D. Misenheimer,
US EPA, March 2017.
21
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Phase
Month
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
Analysis
1
Conceptual Studies / Design
2
Specifications / Vendor Bids / Financing
Implemen tation
3
Construction Permit
4
Detailed Engineering / Fabrication
5
Site Work / Mobilization
6
Equipment Installation
7
Start-up / Testing
8
Operating Permit
Figure 4-1. General Installation Timeline: Large Add-On Controls
Phase
Month
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
Analysis
1
Conceptual Studies / Design
2
Specifications / Vendor Bids / Financing
Implementation
3
Construction Permit
4
Detailed Engineering / Fabrication
5
Site Work / Mobilization
6
Equipment Installation
7
Start-up / Testing
8
Operating Permit
Figure 4-2. General Installation Timeline: Combustion Controls or Compact Add-On Controls
22
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As indicated in the figures above, some overlap can occur among the phases of installation. For example,
review of construction permit applications often occurs before the end of the analysis phase, since
affected sources would not go out to bid on a project or sign contracts with vendors before receiving
construction permits. In addition, site work can also begin before the control equipment is fabricated
and delivered. The greater the amount of such overlap in phases of installation, the less time control
installation may take. Additional descriptions of the activities occurring within each phase of control
installation follow:
1. Conceptual Studies/Design Basis - In the first phase of technology evaluation, an engineering review
and assessment of the combustion unit is conducted to determine the preferred compliance
alternative. During this phase, the specifications of the control technology are determined, and bids
are requested from vendors. A request for proposal (RFP) is often a route by which to accomplish
this. An RFP is submitted for emission control vendors to present competing technologies, their
capabilities, and their approximate costs (often +-30%, or study-level in accuracy).69 The RFP process
is a broad market sweep that invites control vendors to propose a remedy for regulatory
compliance, which then allows the owner to focus on a technology, consider budgetary constraints,
and narrow the list of competing vendors. The RFP process can often take 3-4 weeks depending on
the extent of the project.
The final part of the pre-award phase involves selecting a control vendor, otherwise known as the
Request for Quotation (RFQ) process. For the vendor, creating a bid package can incur substantial
development costs since this requires assembling sufficient staff to develop an accurate price based
on current market conditions for key inputs (materials, labor, etc.) while adhering to the client's
specifications in the RFQ. Typically, the vendor commits a month to create a bid package, but the
process can end in 6-8 weeks. An owner's review of vendor bids may take 3-4 months before
targeting a single vendor. However, much of this effort can be conducted simultaneously with the
permit application process (discussed below), leaving the final contract signature to be done.
Depending on the complexity of the control retrofit, commenters on similar EPA rulemakings stated
that it can take 6-8 months after the rule is finalized to select a control option and hire an
installation contractor.
2. Specifications/Vendor Bids/Financing- Once both parties (i.e., a buyer organization and seller
organization) agree on the technical and commercial terms and conditions of the proposal, they
move on to next steps like contract signing and statement of work, which formalize the purchase
transactions. Financing for equipment purchases is also conducted during this phase.
3. Preparation and Review of Construction Permits - Before construction to install the technology can
commence, the facility must prepare, submit, and receive approval for a construction permit from
the relevant federal, state or local regulatory authority. The construction permit covers modifying
existing equipment or installing new equipment. A construction permit application can include the
following elements: a) project description, b) emission controls, c) project operation, d) site layout,
e) waste disposal, and f) construction activities. The permitting agency reviews the application and
issues a draft approval. Construction permit processing times typically range from 3 months to a
year.
69 B. Lange, Eastern Research Group, "NOx APCD Installation Times Early Findings," prepared for D. Misenheimer,
US EPA, March 2017.
23
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4. Detail Engineering/Fabrication - Even after a company hires a vendor, the company needs
additional time to order and install equipment. The length of time depends on the types of
equipment or controls chosen and obtaining certain pieces of equipment sometimes involves
significant lead times. When engineering details are finalized, equipment is fabricated under this
phase.
5. Site Work/Mobilization - During the pre-construction stage, a site investigation must be completed.
A site investigation identifies any steps that need to be implemented on the job site before the
actual construction begins. Most of the construction activities, such as earthwork, foundations,
process electrical and control tie-ins to existing items, can occur while the emitting unit is in
operation.
6. Equipment Installation - This phase addresses all on-site installation activities. For most types of
NOx control, the affected units may need to be shut down to allow for installation.
7. Startup and Testing - Newly installed equipment requires a shakedown or a trial period to identify
and address any issues before the control device is declared operational.
8. Revision and Review of Operating Permits - Facilities must also modify their Title V operating permit
to incorporate the added control devices and the associated reduced emission limits. The review
and revision of operating permits can include the following elements: a) current and projected
emissions, b) identification of regulatory status for multiple Clean Air Act programs, such as
Prevention of Significant Deterioration (PSD)/ New Source Review (NSR), Regional Haze, and various
Federal water programs (e.g., National Pollutant Discharge Elimination System), and c) state and
local requirements.
Table 4-1 presents estimates of the amount of time required for individual sources affected by the final
rule to install the controls that EPA estimates might likely be installed for compliance.70 The amount of
time required for equipment design/fabrication/installation was taken from information in comments to
the proposed rule and supporting technical documents. These estimates do not include the additional
time required for the analysis phase and permitting. Thus, estimates of the time needed for the analysis
phase and permitting are presented in a separate column. Assumptions for these phases are as
follows:71
• Conceptual Studies/Design: range of months for SNCR/SCR: 1-5 months; low end of range
assumed for combustion controls and compact add-ons.
• Specs/Vendor Bids/Financing: range of months for SNCR/SCR: 2-6 months; low end of range
assumed for combustion controls and compact add-ons.
• Permitting: range of months for any control type: 2-12 months; includes both construction and
operating permit phases. The final two months are assumed for the operating permit, where
those are separate from construction permits. For layered combustion or NSCR applied to RICE
in natural gas transportation or LNB applied to boilers and furnaces, 2-3 months is expected.
For all other controls, a range of 6 -12 months is expected.
70 For facilities that have multiple affected units to address, the amount of time required to install each control
could be reduced on average, since a single permit review process would likely be involved among other
efficiencies in equipment design, fabrication, and installation.
71 Lange, B., Eastern Research Group, Technical Memorandum (NOx APCD Installation Times Early Findings) to D.
Misenheimer, US EPA, March 3, 2017.
24
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Table 4-1. Estimated Time Requirements for Individual Sources Affected by the Final Rule
Industry
Emissions
Source
Group
Estimated
Control
Technology
Estimated Time Required (months)
Equipment
Design /
Fabrication/
Installation
Analysis
Phase/
Permitting
Total
Range
Cement and Concrete
Product Manufacturing
Kilns
SNCR
11 -12
6 -12
17-24
Glass and Glass Product
Manufacturing
Melting
Furnaces
LNB
6-9
3-6
9 -15
Iron and Steel Mills and
Ferroalloy Manufacturing
Reheat
Furnaces
LNB
6-9
3-6
9 -15
Pipeline Transportation of
Natural Gas
RICE 2-Cycle
Layered
Combustion
3-6
3-6
6 -12
Pipeline Transportation of
Natural Gas
RICE 4-Cycle
Rich Burn
NSCR
3-6
3-6
6 -12
Pipeline Transportation of
Natural Gas
RICE
unspecified
NSCR or
Layered
Combustion
3-6
3-6
6 -12
Pipeline Transportation of
Natural Gas
RICE 4-Cycle
Lean Burn
SCR
7 -13
3-6
10 -19
Affected Non-EGUa
Industries
Boilers
LNB + FGR
6-9
3-6
9 -15
Affected Non-EGUa
Industries
Boilers
SCR
8-13
6 -12
14-25
Municipal Waste
Management
MWC Boilers
LNtm + SNCR
16
6 -12
22-28
Municipal Waste
Management
MWC Boilers
ASNCR
11
6 -12
17-23
a The affected non-EGU industries with boilers include Iron and Steel Mills and Ferroalloy Manufacturing, Metal
Ore Mining, Basic Chemical Manufacturing, Petroleum and Coal Products Manufacturing, and Pulp, Paper, and
Paperboard Mills.
Based on contacts with state permitting staff, the time estimated in this report for permitting is
conservatively long (that is, more likely to be overstated than understated).72 The effort required to
prepare and review air permit modifications for NOx control installations is much less than the effort
required for the initial operating (Title V) permit. Most state permitting staff that offered information for
this report indicated that permit modifications were likely to be processed in less than six months; and,
for some states, expedited permitting programs are in place. These programs allow for a source to pay
an additional fee to have their permit modification expedited. On the other hand, it is possible that
some control installations may have the potential to trigger more complex reviews. In those instances,
72 S. Roe, SC&A, Inc., personal communications with: L Warden, Oklahoma Department of Environmental Quality,
October 24, 2022; S. Short, Texas Commission on Environmental Quality, October 27, 2022; B. Johnston, Louisiana
Department of Environmental Quality, October 25, 2022; and H. Bouchareb, Minnesota Pollution Control Agency,
September 7, 2022.
25
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the permit timelines indicated above are appropriate (including time required for public comment, if
needed). For all NOx controls, except large SCR/SNCR applications, the estimated time required for
analysis and permitting is 3 to 6 months. For large SCR/SNCR applications, the estimated time required is
6 to 12 months.
4.2 Issues Identified by Commenters Related to Timing
EPA solicited and received comments on the proposed rule related to the timing of control installations
for non-EGU NOx sources. Often, commenters indicated that 36 months for installation of controls was
not feasible, without identifying alternative timelines for achieving compliance.73 However, while few
commenters identified alternative control installation timelines, commenters identified several key
issues that could impact the timeline. These are discussed below.
Supply Chain Concerns
Concerns expressed by regulated-industry commenters on access to NOx control technologies included
the following:
• A limited pool of skilled installers: especially for combustion controls on RICE for natural gas
transmission. Discussions with control equipment vendors have also indicated a limited pool of
SNCR suppliers with MWC expertise. Industries potentially impacted: Pipeline Transportation of
Natural Gas and Solid Waste Incinerators and Combustors.
• Competition among affected units to source control equipment vendors: for example, operators
of ICI boilers and MWCs may have to compete with EGUs for SCR and SNCR vendors. A small
number of EGU SCR retrofits are expected between 2023 and 2027 (2.6 - 8 GW of capacity).
Also, the Agency estimates roughly 265 SCR and SNCR EGU optimization projects are expected
within this time period. Given their much larger size and history with EGUs, commenters were
concerned that some of these equipment vendors would focus attention first on affected EGUs.
As a result, the size of the vendor pool available to service non-EGU affected units would be
smaller. Industries potentially impacted: Iron and Steel Mills and Ferroalloy Manufacturing,
Metal Ore Mining, Basic Chemical Manufacturing, Petroleum and Coal Products Manufacturing,
and Pulp, Paper, and Paperboard Mills, and Solid Waste Incinerators and Combustors.
• General concern about long lead times for selected equipment vendors to design, fabricate and
install control equipment. These comments did not offer specifics about the expected source(s)
of equipment delays; however, they seem to stem from known production outages for control
equipment components (such as those obtained from Chinese suppliers), transportation
bottlenecks (including delays at US ports), and known current backlogs of North American
equipment fabricators.
Supply chain issues and their potential to cause control installation delays are assessed in Section 5 of
this report.
73 For example, steel industry comment [EPA-HQ-OAR-2021-0668-0360. Comment submitted by JSW Steel (USA)
Inc. and JSW Steel USA Ohio, Inc.], Paper industry comment [EPA-HQ-OAR-2021-0668-0338. Comment submitted
by Wisconsin Paper Council (WPC)], requests extension to the 2028 ozone season. Solid waste combustion
(resource recovery) industry comment [EPA-HQ-OAR-2021-0668-0301. Comment submitted by Minnesota
Resource Recovery Association (MRRA)].
26
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Additional Issues
As mentioned previously, operators of furnaces used in glass manufacturing expressed concern about
the need to install controls at an early point in the useful life of the furnace lining (refractory).74 A
number of commenters from the glass manufacturing industry said installing a control would require a
cold shutdown of the furnace which would likely damage the refractory (furnaces are designed to run
continuously between re-linings). Since a refractory might have a service life of 6 to 15 years, rule
compliance extensions were requested of potentially many years beyond the May 2026 deadline (i.e.,
dependent on unit-specific circumstances).
While not a requirement of this final rule, commenters said some non-EGU coal-fired boiler operators
and other non-EGUs may opt to switch to natural gas to achieve compliance. But these commenters
said, if the natural gas infrastructure is not in place locally, additional time would likely be needed to
bring natural gas to the site.75
4.3 Evaluation of Timing for Each Industry
This section includes an industry-specific assessment of the amount of time required for installation of
each type of NOx control technology estimated to be installed in that industry to comply with the final
rule. This discussion is focused on the time needed for an individual control technology installation. Note
that the installation timing estimates presented in this section do not include the additional estimated
time that could be needed assuming supply chain delays, which are discussed in Section 5. Section 4.4
provides an analysis of the timing needed to install NOx control technologies on all affected units
(including EGU installations required by May 2026).
Cement and Concrete Product Manufacturing
Table 4-2 provides EPA's estimates of the NOx controls likely to be installed in the cement
manufacturing industry and the number of affected units by emissions source group.76 A total of 16
SNCR systems are estimated to require installation, including both process and preheater/precalciner
kilns.
Table 4-2. Potential Control Installations for Cement and Concrete Product Manufacturing
Number
Emissions Source Group
Control Technology
of Units
Kiln- Dry Process
Selective Non-Catalytic Reduction
8
Preheater/Precalciner Kiln
Selective Non-Catalytic Reduction
4
Preheater Kiln
Selective Non-Catalytic Reduction
3
Kiln- Wet Process
Selective Non-Catalytic Reduction
1
Total SNCR
16
74 EPA-HQ-OAR-2021-0668-0406. Comment submitted by Ardagh Glass Inc. EPA-HQ-OAR-2021-0668-0548.
Comment submitted by Glass Packaging Institute (GPI). EPA-HQ-OAR-2021-0668-0321. Comment submitted by
Vitro Flat Glass LLC and Vitro Meadville Flat Glass, LLC.
75 EPA-HQ-OAR-2021-0668-0320. Comment submitted by Genesis Alkali Wyoming, LP. EPA-HQ-OAR-2021-0668-
0437. Comment submitted by American Forest & Paper Association (AF&PA).
76 U.S. EPA, Summary of Final Rule Applicability Criteria and Emissions Limits for Non-EGU Emissions Units,
Assumed Control Technologies for Meeting the Final Emissions Limits, and Estimated Emissions Units, Emissions
Reductions, and Costs. Technical Memorandum, March 15, 2023.
27
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Although excessive on-off cycling of a cement kiln could also damage the refractory material (e.g., brick
lining), some amount of cycling occurs in the industry for varying reasons.77 Still, some consideration of
timing for a kiln shutdown for the purposes of installing air pollution controls may be needed (i.e.,
timing to coincide with other preventive maintenance needs).
References on time for compliance are as follows without emission source group categorization. EPA's
2021 Non-EGU sectors TSD estimates the cement and concrete product manufacturing industry will take
between 10-12 months for SNCR to be installed.78 In the same TSD, EPA also noted an estimate of 19
months for SNCR applied to EGUs.79 This latter estimate took into greater account the time needed for
engineering, design, testing and permitting, albeit for an EGU application.
The Institute of Clean Air Companies (ICAC) timeline for installing SNCR is shown in Table 4-3 divided
into phases (this information was also used in subsequent EPA timelines).80 These values apply to
industrial boilers, kilns, preheater kilns, and preheater/precalciner kilns. The total SNCR installation
timeline is estimated to be 11 to 12 months as shown in Table 4-3. No consideration of the amount of
time required for permitting was included in the ICAC timeline. Therefore, 6 to 12 months was added to
the total time in Table 4-3 to accommodate this phase (this results in a conservatively long timeline,
since permitting analyses may proceed concurrent with other phases). This results in a total timeline of
17 to 24 months. These values should be understood to reflect the time required for a single affected
unit to apply the control.
Table 4-3. ICAC Timeline for SNCR Installation for Cement and Concrete Product Manufacturing81
Phase
Timeline (weeks)
1. Conceptual Studies / Design
2-4
2. Specifications / Vendor Bids / Financing
8-12
3. Construction Permit
-
4. Detailed Engineering / Fabrication
16
5. Site Work / Mobilization
-
6. Equipment Installation
8-12
7. Start-up / Testing
9
8. Operating Permit
-
Total time:
11-12 months
Total time, including permitting:
17-24 months
77 Infinity for Cement Equipment, Kiln Refractory Requirement, Properties & Factors Affect Wear, website at
https://feeco.com/rotary-kiln-refractory-preventative-care/.
78 Page 87. Non-EGU Sectors TSD, Draft Technical Support Document (TSD) for the Proposed Rule, Docket ID No.
EPA-HQ-OAR-2021-0668, December 2021.
79 Page 88 Non-EGU Sectors TSD, Draft Technical Support Document (TSD) for the Proposed Rule, Docket ID No.
EPA-HQ-OAR-2021-0668, December 2021.
80 ICAC, 2006. Typical Installation Timelines for NOx Emissions Control Technologies on Industrial Sources,
December 4, 2006.
81 Ibid.
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Glass and Glass Product Manufacturing
Table 4-4 provides EPA's estimates for the NOx controls likely to be installed for the glass and glass
products manufacturing industry.82 A total of 61 LNB control installations are estimated for the industry,
including container, pressed and blown, and flat glass processes.
Table 4-4. Potential Control Installations for Glass and Glass Product Manufacturing
Emissions Source Group
Control Technology
Number
of Units
Container Glass: Melting Furnace
Low NOx Burner
36
Flat Glass: Melting Furnace
Low NOx Burner
12
Pressed and Blown Glass: Melting Furnace
Low NOx Burner
11
Furnace: General
Low NOx Burner
1
Unspecified
Low NOx Burner
1
Total
61
Vitro Glass and other commenters stated that more than 36 months would be needed to install
controls.83 Supply chain delays, competition among affected units to procure and install controls, and
time requirements for engineering and permitting were all mentioned as concerns. A complete shut-
down of a glass furnace for NOx control installation requires a re-lining of the furnace (since the lining is
damaged during cooling). A flat glass furnace might run continuously for 15 years between re-linings.
Ardagh Glass indicated a 10-year timeframe for furnace re-bricking.84 Commenters asked for flexibility to
account for this issue, so that a manufacturer would not incur the cost of a re-lining well before the end
of the useful life of the refractory.
As shown in Table 4-5, the expected installation timeline for installing LNB to glass furnaces is 9 to 15
months. This is based on general installation timelines for LNB or LNB+FGR applied to industrial sources
of 6 to 9 months from ICAC85 which are also documented in a 2017 EPA technical memorandum.86 The
total includes an additional 3 to 6 months to cover the conceptual studies/design and permitting phases
(this is a conservatively long, or more likely an overstated estimate, since some of these phases may
proceed concurrently). Based on discussions with state permitting staff, that amount of time should be
sufficient to address situations where more complex permitting issues arise (e.g., PSD). The timeline in
Table 4-5 reflects the time required to install LNB for a single affected unit.
82 U.S. EPA, Summary of Final Rule Applicability Criteria and Emissions Limits for Non-EGU Emissions Units,
Assumed Control Technologies for Meeting the Final Emissions Limits, and Estimated Emissions Units, Emissions
Reductions, and Costs. Technical Memorandum, March 15, 2023.
83 EPA-HQ-OAR-2021-0668-0321. Comment submitted by Vitro Flat Glass LLC and Vitro Meadville Flat Glass, LLC.
84 EPA-HQ-OAR-2021-0668-0406. Comment submitted by Ardagh Glass Inc. Commenter referenced San Joaquin
Valley Air Pollution Control District's Rule 4354, which allows for compliance deadlines based in part on furnace
rebuilds.
85 ICAC 2006. Typical Installation Timelines for NOx Emissions Control Technologies on Industrial Sources,
December 4, 2006.
86 Lange, B., Eastern Research Group, Technical Memorandum (NOx APCD Installation Times Early Findings) to D.
Misenheimer, US EPA, March 3, 2017.
29
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Table 4-5. LNB or LNB+FGR Installation Timeline for Glass and Glass Products Manufacturing
Installation
Phase
Timeline (weeks)
1. Conceptual Studies / Design
-
2. Specifications / Vendor Bids / Financing
6-10
3. Construction Permits
-
4. Detailed Engineering / Fabrication
6-9
5. Site Work / Mobilization
10-12
6. Equipment Installation
2-3
7. Start-up / Testing
1
8. Operating Permits
-
Total time:
6-9 months
Total time including permitting:
9-15 months
Iron and Steel Mills and Ferroalloy Manufacturing
Table 4-6 provides EPA's estimates for the NOx controls likely to be installed for reheat furnaces in the
iron and steel and ferroalloy manufacturing industry based on analyses performed for the final rule.87
There are 19 reheat furnaces in the iron and steel industry that are estimated to need combustion
controls (LNB) to meet the applicable NOx control requirements.
Table 4-6. Potential Control Installations for Iron and Steel Mills and Ferroalloy Manufacturing
Emissions Source Group
Control Technology
Number of Units
Natural Gas: Reheat Furnaces
Low NOx Burners
19
The installation timeline for LNB on reheat furnaces is estimated to be the same as that shown above in
Table 4-5 for other LNB installations.
Pipeline Transportation of Natural Gas
Table 4-7 provides EPA's estimates for the NOx controls likely to be installed for pipeline transportation
of natural gas.88 EPA has estimated the number of engines that may have to install controls according to
the final rule cost analysis to be approximately 905. For 323 of these RICE, the combustion configuration
was unknown, and those RICE are estimated to apply either NSCR or layered combustion.
87 U.S. EPA, Summary of Final Rule Applicability Criteria and Emissions Limits for Non-EGU Emissions Units,
Assumed Control Technologies for Meeting the Final Emissions Limits, and Estimated Emissions Units, Emissions
Reductions, and Costs. Technical Memorandum, March 15, 2023.
88 U.S. EPA, Summary of Final Rule Applicability Criteria and Emissions Limits for Non-EGU Emissions Units,
Assumed Control Technologies for Meeting the Final Emissions Limits, and Estimated Emissions Units, Emissions
Reductions, and Costs. Technical Memorandum, March 15, 2023.
30
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Table 4-7. Potential Control Installations for Pipeline Transportation of Natural Gas
Number
Emissions Source Group
Control Technology
of Units
2-cycle Lean Burn
Layered Combustion
394
4-cycle Rich Burn
Non-Selective Catalytic Reduction
30
Non-Selective Catalytic Reduction or
Reciprocating
Layered Combustion
323
4-cycle Lean Burn
Selective Catalytic Reduction
158
Total
905
For pipeline transportation of natural gas, most of the comments pertaining to this industry addressed
the time needed to implement combustion controls. Commenters stated that the 3-year timeframe for
compliance with the proposed FIP was not technically feasible due to concerns about the supply chain
(in particular, the size of the skilled labor pool with expertise in RICE retrofits), permitting backlogs due
to the large number of potentially affected units, and the need to allow sufficient time for planning
around taking compressors offline to avoid system reliability concerns (including the need to meet FERC
pipeline pressure obligations by each compressor station).
In 2006, an air pollution controls association estimated that the amount of time required to conduct
conceptual studies/engineering, develop specifications/vendor bids/financing, and equipment
installation ranged from 2 to 3.5 months.89 This is similar to a minimum time estimate from EPA of 3.5
months.90
Estimates for NOx control installation timing provided in industry comments to the proposed rule
ranged from 21 months91 to 60 months92. The higher estimates incorporate asserted expected delays
from permitting or supply chain concerns (i.e., all affected units encounter delays). The ranges cover
different control technologies (SCR, NSCR) and all engine types.93
Table 4-8 shows the estimated installation timelines for RICE SCR and NSCR/LC installation. The values in
Table 4-8 apply to a single unit. An additional three to six months of time was added to both the EPA and
ICAC timelines to account for permitting. This six-month estimate is based on contacts with permitting
staff in multiple states. It represents a conservative (or lengthier) timeframe for these controls that
should account for situations where more complex permitting issues arise (e.g., PSD). It is also
89 Institute of Clean Air Companies (ICAC), 'Typical Installation Timelines for NOx Emissions Control Technologies
on Industrial Sources," December 2006.
90 Eastern Research Group, "RICE Retrofits: Development Time for NOx Control Measures," Technical
Memorandum to D. Misenheimer, US EPA, March 2017.
91 EPA-HQ-OAR-2021-0668-0380. Comment submitted by TC Energy.
92 EPA-HQ-OAR-2021-0668-0371. Comment submitted by INNIO Waukesha Gas Engines (INNIO Waukesha). While
this commenter suggested allowing until May 1, 2028 for all installations to be completed, they also proposed
phasing in the controls beginning two years from the effective date of the rule. The commenter suggested a six-
year phase in from effective date; however, they also indicated that 48-60 months would be sufficient.
93 We note that these estimates from commenters could not be independently verified for this report.
31
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conservative (that is, likely overstates the needed timelines) because some of the phases identified in
the timelines shown in Table 4-8 for both controls may proceed concurrently.
Table 4-8. Timeline for Installation of NOx Controls for RICE in Pipeline Transportation of Natural Gas
Phase
Installation Timeline (weeks)
SCR
NSCR/LC
US EPA94
US EPA95 and ICAC96
1. Conceptual Studies / Design
-
4-6
2. Specifications / Vendor Bids / Financing
6-8
2-4
3. Construction Permits
-
-
4. Detailed Engineering / Fabrication
6-16
4-6
5. Site Work / Mobilization
-
-
6. Equipment Installation
14-28
1-2 (US EPA)
2-4 (ICAC)
7. Start-up / Testing
2-6
1-2
8. Operating Permits
-
-
Total time:
7-13 months
3-6 months
Total time, including permitting:
10 -19 months
6-12 months
Boilers in Affected Industries
Table 4-9 provides EPA's estimates for the NOx controls likely to be installed for boilers at industries
affected by the final rule.97 They are addressed collectively here, because the sources and control types
are similar across industries. Generally, the sources are medium (10 - 100 million Btu/hr) and large
boilers (>100 million Btu/hr) fired on a variety of gaseous, liquid, and solid fuels. Combustion controls
estimated for rule compliance are mainly the application of low NOx burners with flue gas recirculation
(151 total installations), while post-combustion controls are estimated to be SCR (15 total installations).
94 Non-EGU Sectors TSD, Draft Technical Support Document (TSD) for the Proposed Rule, Docket ID No. EPA-HQ-
OAR-2021-0668, December 2021.
95 Eastern Research Group, "RICE Retrofits: Development Time for NOx Control measures," Technical
Memorandum to D. Misenheimer, US EPA, March 2017.
96 Institute of Clean Air Companies, "Typical Installation Timelines for NOx Emissions Control Technologies on
Industrial Sources, Washington DC, December 4, 2006.
97 U.S. EPA, Summary of Final Rule Applicability Criteria and Emissions Limits for Non-EGU Emissions Units,
Assumed Control Technologies for Meeting the Final Emissions Limits, and Estimated Emissions Units, Emissions
Reductions, and Costs. Technical Memorandum, March 15, 2023.
32
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Table 4-9. Potential Control Installations for Boilers in Affected Industries
Industry
Emissions Source Group
Control Technology
Number
of Units
Basic Chemical
Manufacturing
Boilers - Distillate Oil
Selective Catalytic Reduction
4
Boilers - Natural Gas
Low NOx Burners and Flue Gas
Recirculation
86
Boilers - Natural Gas:
Cogeneration
Low NOx Burners and Flue Gas
Recirculation
1
Boilers - Residual Oil
Selective Catalytic Reduction
1
Boilers - Subbituminous Coal:
Traveling Grate (Overfeed)
Stoker
Selective Catalytic Reduction
1
Petroleum and Coal
Products Manufacturing
Boilers - Natural Gas
Low NOx Burners and Flue Gas
Recirculation
9
Boilers - Natural Gas:
Cogeneration
Low NOx Burners and Flue Gas
Recirculation
1
Boilers - Residual Oil
Low NOx Burners and Flue Gas
Recirculation
4
Iron and Steel Mills and
Ferroalloy
Manufacturing
Boilers - Coke Oven
Gas/Natural Gas
Low NOx Burners and Flue Gas
Recirculation
3
Boilers - Natural Gas
Low NOx Burners and Flue Gas
Recirculation
9
Metal Ore Mining
Boilers - Distillate Oil/ Natural
Gas
Low NOx Burners and Flue Gas
Recirculation
2
Pulp, Paper, and
Paperboard Mills
Boilers - Bituminous Coal:
Pulverized Coal: Dry Bottom
Selective Catalytic Reduction
1
Boilers - Bituminous Coal:
Spreader Stoker
Selective Catalytic Reduction
1
Boilers - Coal: Dry Bottom
Selective Catalytic Reduction
4
Boilers - Distillate Oil/Natural
Gas
Selective Catalytic Reduction
2
Boilers - Natural Gas
Low NOx Burners and Flue Gas
Recirculation
32
Boilers - Natural
Gas/Bituminous Coal: Dry
Bottom (Tangential)
Selective Catalytic Reduction
1
Boilers - Natural Gas:
Cogeneration
Low NOx Burners and Flue Gas
Recirculation
2
Boilers - Residual Oil /Natural
Gas
Low NOx Burners and Flue Gas
Recirculation
1
Boilers - Residual Oil/Distillate
Oil
Low NOx Burners and Flue Gas
Recirculation
1
Total Combustion Controls
151
Total SCR
15
33
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The timeline for installation of LNB+FGR to boilers in the affected industries is estimated to be the same
as the values provided in Table 4-5 above (a total of 9-15 months).
According to EPA, the expected time needed to implement SCR controls on boilers in these industries is
8-13 months, as shown in Table 4-10.98 An additional 6-12 months was also added to address
permitting, which is a conservatively long estimate since permitting analyses may generally proceed
concurrent with other phases.
Table 4-10. EPA's Estimated Potential Installation Timeline for Applying SCR to Boilers in the Affected
Industries
Installation Timeline (weeks)
Phase
SCR"
1. Conceptual Studies / Design
1-4
2. Specifications / Vendor Bids / Financing
5-8
3. Construction Permits
-
4. Detailed Engineering / Fabrication
4-6
5. Site Work / Mobilization
12-22
6. Equipment Installation
4-8
7. Start-up / Testing
5-10
8. Operating Permits
-
Total time:
8-13 months
Total time, including permitting:
14-25 months
Municipal Waste Combustion
As shown in Table 4-11, EPA has estimated that 57 MWCs may install ASNCR, with an additional four
MWC units likely to install Covanta's low NOx combustion controls in combination with an existing SNCR
system.100
98 Lange, B., Eastern Research Group, Technical Memorandum (NOX APCD Installation Times Early Findings) to D.
Misenheimer, US EPA, March 3, 2017. This estimate is believed to be based on an earlier ICAC estimate of 7 to 9
months for SCR applied to non-EGU sources. Institute of Clean Air Companies, "Typical Installation Timelines for
NOx Emissions Control Technologies on Industrial Sources, Washington DC, December 4, 2006.
99 Lange, B., Eastern Research Group, Technical Memorandum (NOx APCD Installation Times Early Findings) to D.
Misenheimer, US EPA, March 3, 2017.
100 U.S. EPA, Summary of Final Rule Applicability Criteria and Emissions Limits for Non-EGU Emissions Units,
Assumed Control Technologies for Meeting the Final Emissions Limits, and Estimated Emissions Units, Emissions
Reductions, and Costs. Technical Memorandum, March 15, 2023.
34
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Table 4-11. Potential Control Installations for MWCs
Emissions Source Group
Control Technology
Number of Units
MB/WW
ASNCR
43
MB/RC
ASNCR
9
MB/WW
LNtm + SNCR
4
CLEERGAS gasification
ASNCR
1
RDF
ASNCR
4
Total Combustion Controls
4
Total ASNCR/SNCR
61
Beyond Plastics and other commenters provided a 2020 engineering study that assessed options for
reducing NOx at an incinerator in Baltimore. The study evaluated options for technologies that could
achieve a 24-hour limit of 110 ppm.101 Table 4-12 summarizes the number of months estimated for each
phase of the control installation, as well as the total project time. The report notes that permitting may
add an additional 6 to 12 or more months to the total time (consistent with the permitting timeframes
needed for large add-on controls at other sources discussed earlier).102 This was a unit-specific study, so
the installation timing for this or other units may be impacted by site-specific considerations.
The total time indicated for application of ASNCR is 17-23 months, which includes 6-12 months for
permitting. The report did not include LNtm + SNCR as one of the options evaluated. However, it did
include FGR in combination with an existing SNCR system, which is the option that likely aligns most
closely with LNtm + SNCR. Therefore, this option is included in Table 4-12 with a total timeline of 22-28
months.
Table 4-12. Estimated Time by Phase for Control Installation Options for a Large MWC (months)
Phase
Installation Timeline (months)
ASNCR
FGR + Existing SNCR
1. Conceptual Studies / Design
3
4
2. Specifications / Vendor Bids / Financing
4
7
3. Construction Permits
-
-
4. Detailed Engineering / Fabrication
-
-
5. Site Work / Mobilization
3
4
6. Equipment Installation
2
3
7. Start-up / Testing
1
2
8. Operating Permits
-
-
Total time:
11
16
Total time, including permitting:
17-23
22-28
101 EPA-HQ-OAR-2021-0668-0757. Comment submitted by Beyond Plastics, et. al.
102 EPA-HQ-OAR-2021-0668-0757. Comment submitted by Beyond Plastics, et. al.
35
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4.4Cumulative Effect of Numerous Control Installations at Same Time on Timing and
Demand for Materials and Services
Overlapping control requirements for the EGU and non-EGU sources may produce challenges for both
the air pollution control industry (e.g., SCR fabricators) and other aligned trades (potentially catalyst
material producers), including those tasked with manufacturing and installing structural components for
large add-on controls. However, vendors have made statements that the availability of raw materials for
fabrication may be increasing.103
Table 4-13 below summarizes the total number of potential non-EGU and EGU control installations
estimated for compliance with the final rule.104 An estimated 229 EGU SCR optimizations and 36 EGU
SNCR optimizations are estimated by May 2026 for this rule. Also, EPA expects that 2.5-8 GW of EGU
capacity may be in the process of applying SCR retrofits between 2023 and 2030. Assuming a nominal
capacity of 500 MW, this represents a maximum of 16 EGU SCR retrofits. Since it is possible that the EGU
SCR retrofits could occur by the 2026 or 2027 ozone season, they were added to the control installations
shown in Table 4-13. The EGU SCR/SNCR optimizations are also included in the table because there is a
potential for overlap in the need for skilled workers to address these optimizations and new non-EGU
equipment installs (SCRs/SNCRs). For EGU SCR/SNCR optimizations, EPA expects that the vast majority
of these will be accomplished by optimizing operations rather than a physical optimization (such as the
addition of catalyst layers). Operational optimizations are expected to be completed by existing EGU
personnel rather than equipment vendors.
Table 4-13. Potential Non-EGU and EGU Control Installations by the 2026 Ozone Season
Number of
Sector
Control Technology
Installations'
External Combustion - SCR
15
External Combustion - SNCR/ASNCR
77
External Combustion - Combustion Controls
231
Non-EGU
RICE - Compact SCR
158
RICE - NSCR
192
RICE - LC
555
Total Non-EGU
1,228
Optimize Existing SCR**
229
Optimize Existing SNCR**
36
EGU (through 2026)**
SCR Retrofits
16
Combustion Controls
10
Total EGU
291
All Sectors
New SCR + SCR Optimizations
260
SNCR/ASNCR + SNCR Optimizations
113
103 Discussions with control equipment vendors have not indicated any current concerns for the availability of raw
materials, such as plate or sheet steel, cement, etc., required for the fabrication of control equipment or the
structural components for their installation. During the pandemic, delays were experienced by equipment
fabricators for sheet stainless steel, but those delays have been alleviated.
104 U.S. EPA, Summary of Final Rule Applicability Criteria and Emissions Limits for Non-EGU Emissions Units,
Assumed Control Technologies for Meeting the Final Emissions Limits, and Estimated Emissions Units, Emissions
Reductions, and Costs. Technical Memorandum, March 15, 2023.
36
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RICE NSCR
192
RICE Compact SCR
158
External Combustion Controls
241
Internal Combustion Controls
555
Total Non-EGU and EGU
1,519
'Note that for 323 RICE, EPA estimates these units to adopt either LC or NSCR. These control
applications were assumed to breakdown 50:50 for representation in this table. Also, note that the EGU
control counts only include applications in the states with estimated non-EGU controls (i.e., EGU
controls for compliance in 2023 in Alabama, Minnesota, Nevada, and Wisconsin are not included here).
**ln most cases, optimization of existing SCR/SNCR controls means to employ practices to improve the
removal rate for existing post-combustion controls such as adjusting the ammonia injection rate, or
adding or regenerating catalyst more frequently, or changes in combustion unit operation or EGU
dispatching to maintain optimal SCR exhaust temperatures.
An estimated 905 RICE units in the natural gas transportation industry may have to install controls in
order to comply with the final rule. The compact SCR and NSCR controls for RICE are supplied by a
different set of vendors than those for non-EGU external combustion sources and EGUs. However, some
overlap in demand for catalyst material (e.g., platinum) is expected among these affected sources.
One possible consideration for control installation timing indicated by the estimates in Table 4-13 above
relate to overlapping requirements for SCR installation/optimization services:
• Number of potential SCR installations and optimizations across the EGU and non-EGU sectors:
there is potential for competition for SCR EPC vendors, in particular for flue gas modeling and
design services. However, based on discussions with SCR vendors, non-EGU design and
installation services are handled by a different group of vendors than EGUs. Given the relatively
small number of non-EGU installations required, there should be sufficient EPC support for non-
EGUs to cover design and engineering services. A separate question is whether equipment
fabricators can address an increase in demand for new SCR and SNCR installs in a timely
manner. As further addressed in Section 5 of this report, equipment fabrication across North
America experienced delay associated with supply chain disruption in the recent past. A
discussion of the potential impacts of SCR catalyst requirements from EGU retrofit and
optimization projects is provided later in this section.
• RICE SCR and NSCR applications: because there is expected to be some overlap in catalyst
demand, the same question regarding catalyst material applies here as mentioned above.
Different equipment vendors serve RICE than those above for external combustion sources, so
there is no concern of overlapping demands.
Each of these areas is addressed in more detail below.
Non-EGU SCR Installations and EGU SCR Optimizations
While Table 4-13 above indicates a total of 418 SCR installations and optimizations across EGUs and non-
EGUs (15 non-EGU external combustion sources, 158 RICE, 16 EGU SCR retrofits, and 229 EGU SCR
optimizations), it is important to divide this total into applicable market segments. This is because
different sets of vendors serve each segment:
37
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• EGUs and large industrial systems: the vendor pool is largely made up of large, sometimes multi-
national, companies that may be a sub-unit of power plant constructors (e.g., Babcock & Wilcox,
General Electric, Mitsubishi Power Systems Americas). These vendors have sufficient size to take
on the financial risk for SCR installations of this scale (e.g., hundreds of MW EGU or very large
industrial boilers). This pool of vendors generally designs the system, and then manages the
subcontracted fabrication and installation phases (so, this pool is referred to here as
engineering, procurement and construction or EPC contractors). An on-line survey and
discussions with some vendors indicate that there are about 10 vendors in this pool in the US
market.105 It is important to note that vendors indicated that perhaps only half of these large
vendors do the design work and manage the fabrication and installation. The rest of the vendors
subcontract out all phases. Appendix A provides a listing of SCR and SNCR vendors with a focus
on North American companies. There may be additional European or Asian (especially Japanese)
vendors serving the North American market. The pool of EPCs may help address a small number
of EGU SCR optimizations noted above (however, in most cases the EGU operator will likely
undertake optimizations without EPC support); but is not expected to pursue smaller non-EGU
systems, such as those that EPA estimates for non-EGU boilers.
• Smaller industrial systems: this pool includes a larger number of vendors serving the industrial
sector and smaller EGUs, such as natural gas turbine plants. These vendors may handle all
phases of SCR design, fabrication, and installation. There appears to be at least 12 vendors for
this pool in the US market (see Appendix A). Given the size of this vendor pool, operators of the
15 affected non-EGU units needing SCR should have ample access to vendor support.
• Compact SCR systems: seven vendors were identified that provide compact systems for internal
combustion engines (see Appendix A). These vendors appear to offer all phases of compact SCR
design, fabrication, and installation.
Skilled Labor. A discussion of available skilled labor for the design phases of SCR systems is presented
below. Section 5 provides an assessment of the fabrication and installation labor needed.
Large system vendors typically handle all the major phases of SCR installation through EPC contracts.
This includes SCR design, fabrication, and installation. Regarding the fabrication and installation work,
much of that is subcontracted out to equipment fabricators and local construction companies. SCR
contacts have indicated that, currently, their staffing levels might support the design and installation of
a half dozen or so systems per year (EGU-sized systems). This compares to twenty or more projects per
year in the late 1990s by the largest vendors to address the demand spurred by the NOx SIP Call. The
relative lack of large SCR projects during the last ten or more years led to a contraction in the number of
vendors and their staffing levels. Vendors were reluctant to suggest that the air pollution control
industry could not quickly respond to a surge in demand, and that, for some companies, additional
105 A&WMA Buyers Guide, website at https://awmabuyersguide.com/. Air Pollution Control Equipment
Manufacturers Listings, An Authoritative List of the Best Air Pollution Control Equipment, website at
https://www.airpollutioncontrolequipment.com/more-air-pollution-control-equipment-manufacturers-listings/.
Institute of Clean Air Companies, ICAC Members, website at https://www.icac.com/page/Members. T. Licata,
Licata Energy & Environmental Consultants, Inc., personal communication with S. Roe, SC&A, Inc., September
2022. D. Harajda, Mitsubishi Power Systems Americas, Inc., personal communication with S. Roe, SC&A, Inc.,
September 2022. F. Collinsworth, CECO Environmental, personal communication with S. Roe, SC&A, Inc.,
September 2022. B. Gretta, SCR Solutions, personal communication with S. Roe, SC&A, Inc., October 2022. R.
Sadler, Catalytic Combustion, Inc., personal communication with S. Roe, SC&A, Inc., October 2022.
38
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system design support could be leveraged from overseas staff.106 In addition to US fabricators, large SCR
system vendors use equipment fabricators in Canada and Mexico, when needed. As noted above, EPA
does expect a relatively small amount of EGU capacity to be retrofit with SCR between 2023 and 2027
(2.5 - 8 GW of capacity or 16 units). However, given the fact that this pool of large system vendors is not
expected to serve the affected non-EGU sources, and that EPA estimates only 15 non-EGU SCR systems
will be installed for compliance with the final rule, significant competition for skilled designers of non-
EGU SCR systems is not expected.
In addition, regarding EGU SCR optimizations, discussions with SCR vendors indicate that most EGUs
may want to use the original equipment manufacturer (OEM) to conduct these optimizations (the OEM
here meaning the builder of the power plant). Thus, SCR vendor support would only be needed for a
very small number of the total 229 EGU optimizations estimated by EPA, since most optimizations will
be done through operational changes conducted by plant staff. Moreover, 2022 data from EGU sources
with existing SCRs illustrates that optimization has already occurred at many sources and future
optimization is just a continuation of scheduled routine maintenance and operation for most sources,
and does not constitute unplanned, incremental demand on system resources in these cases.
Complementing this notion, EPA's assumptions for deriving emission performance consistent with
optimization utilizes a methodology that allows for routine - rather than increased - catalyst
replacement. The pool of qualified vendors is much larger than just these OEMs. It includes smaller SCR
system vendors and architectural and engineering firms with power sector expertise. Where physical
optimizations are employed, they could range from simple catalyst upgrades or additions of catalyst
layers or to upgrades of the reagent mixing systems and/or ammonia flow control units.107 Those
requiring enhanced mixing would require vendors with flow modeling expertise (generally, the large SCR
vendor pool). Again, EPA's expectations for EGU optimizations are that the vast majority of these will be
operational optimizations, including more frequent maintenance, or changes to the operation of the
combustion unit or dispatching of the EGU to maintain optimal exhaust temperatures for the SCR. These
are changes that will not place additional demand on the skilled labor pool.
For non-EGUs, EPA has estimated that 15 SCR systems, excluding compact SCR systems that are
expected to be applied to natural gas compressor engines, will likely be installed. The 12 or so vendors
of the small SCR vendor pool may need to be able to design/fabricate/install on average 1 or 2 SCR
systems prior to May 2026. Based on discussions with vendors, the number of new systems should
easily be designed and engineered within 1 to 2 years. Equipment fabrication and installation should
also be completed during the timelines indicated above barring delays in fabrication or raw materials
supply. More information on indicators for fabrication activity are provided in Section 5.
EPA estimates that another 77 SNCR/ASNCRs will likely be installed for non-EGU affected units with
about three quarters of those being MSW combustors. Nine SNCR vendors were identified from an
internet search that serve the North American market (see Appendix A). At least three of these also
provide ASNCR based on information from their websites. If all 77 installations are distributed among
the SNCR system vendors, on average, each would need to have the capacity to design, fabricate and
install 8 to 9 SNCR/ASNCR systems within a three-year period (or 2 to 3 each per year). Based on
106 For example, Mitsubishi Power Systems Americas also have SCR designers in Japan.
107 D. Harajda, Mitsubishi Power Systems Americas, personal communication with S. Roe, SC&A, Inc., September
2022.
39
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discussions with system vendors, this number of new installations should be achievable for the control
industry.
One potential complicating factor related to the number of estimated new non-EGU SNCR/ASNCR
installations is that 61 are in the municipal waste combustion industry. Not all the vendors listed in
Appendix A may have expertise working with MWCs, and this could reduce the size of the vendor pool. If
the pool with MWC expertise is assumed to be only 3 to 5 vendors, then on average, each would need to
install 12 to 20 systems by May 2026. This number of installations per vendor could be difficult for
vendors to support based on discussions with control equipment vendors, which suggested that 3 to 5
systems per year is the capacity for some vendors. If, on the other hand, a larger number of vendors
have or gain sufficient expertise to work with MWCs, then the number of installations requested of each
vendor would be reduced, and the vendor pool may be able to support the demand for new
SNCR/ASNCR installations at MWCs by May 2026.
For compact SCR and NSCR systems applied to RICE, feedback from one system supplier did not indicate
a significant concern for the air pollution control industry to meet the demand for the estimated 350
systems by May 2026.108 This is because of the influence of the construction of data centers in recent
years. Many diesel- and natural gas-powered RICE have been installed at data centers in recent years for
backup power, and many of these have required SCR. A single large data center could require dozens of
compact SCR systems. Therefore, the contact believed that an additional demand of several hundred
compact SCR systems over a 3-year period would not be difficult for the industry to meet.
Availability of Raw Materials. Discussions with control equipment vendors did not uncover any
concerns regarding the availability of raw materials needed to fabricate and install NOx controls (e.g.,
sheet or plate steel, cement). Some concerns were raised in comments by a large-scale SCR OEM and
catalyst supplier about the availability of sufficient catalyst to cover all the new SCR systems and
optimizations.109 A 600 MW EGU might have 3 to 4 layers of catalyst of 300 cubic meters (m3) each. A
single SCR optimization project could involve the addition of another layer, or it could involve a
complete change-out of catalyst. It is anticipated that most of the 229 EGU SCR optimizations will have
been conducted by the 2023 ozone season. In addition, it is anticipated that a small number of EGUs will
retrofit SCR (new system installs) on 2.5 - 8 GW (potentially up to 16 EGUs at 500 MW capacity) by the
2026 or 2027 ozone season.110 EGU SCR "optimizations" cover an array of operational or physical
alterations:
• Operational optimizations: these can be made without any physical alterations to the source or
SCR system and include increasing maintenance, optimizing reagent injection, or changing
combustion conditions to assure that the exhaust is meeting optimal temperatures for the SCR
system (e.g., assuring that the EGU is dispatch schedule maintains adequate exhaust
temperature);
108 R. Sadler, Catalytic Combustion, personal communication with S. Roe, SC&A, Inc., October 10, 2022.
109 D. Harajda, Mitsubishi Power Americas, personal communication with S. Roe, SC&A, Inc., October 27, 2022.
110 U.S. EPA, "EGU NOx Mitigation Strategies Final Rule TSD," Technical Support Document (TSD) for the Final
Federal Good Neighbor Plan for the 2015 Ozone National Ambient Air Quality Standards, Docket ID No. EPA-HQ-
OAR-2021-0668, March 2023.
40
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• Physical optimizations: these include a complete change-out of catalyst material or the addition
of another catalyst layer.
Depending on the number of EGU operators that elect physical optimizations to their SCR systems, a
short-term spike in demand for catalyst material could be a concern. However, very few EGU operators
are expected to elect to conduct physical optimizations. We were unable to source sufficient
information from catalyst suppliers to gauge the significance of these new demands including the
potential length of any associated supply chain delay.
The information reviewed indicates that any resulting increase in catalyst demand can easily be met via
new production and/or the recycling of catalyst material from retired EGUs equipped with SCR. It can be
noted that roughly 24 GW of EGUs with SCR are currently planning to retire (or have retired) between
Jan 2021 and May 2026.111 This would lower demand for catalyst, likely significantly more than any
increased demand from EGU SCR optimization or retrofits and the non-EGU new SCR installs addressed
in this report. In addition, the catalyst material from these retired units will be available for recycling
(reducing the need to source new raw materials).
RICE NOx Combustion Control Installations
EPA has estimated for the final rule that layered combustion (LC) installations could be from 394 to 717
affected units out of a total of an estimated 905 engines anticipated to install some form of NOx control.
The higher end of the range addresses compressor engines for which EPA did not have details on engine
cycle; depending on configuration, operators could apply either LC or NSCR.
4.5 Control Vendor Demand/Capacity
Industry commenters on the rule stated a concern about vendor capacity in terms of the availability of
SCR or SNCR manufacturers to simultaneously meet the needs of both EGU and non-EGU sources
affected by the rule. Table 4-14 provides a summary of the number of EGU and non-EGUs estimated to
install either SCR or SNCR. Note that these exclude compact SCR systems applied to RICE. An internet
search identified over 20 companies operating in the US that provide SCR
design/construction/installation (see Appendix A). At least nine of these serve the large EGU market
(coal-fired power plants) and smaller EGUs (e.g., natural gas turbine plants). The others serve small EGUs
and non-EGU sources. Nine SNCR vendors were identified that serve the US market.
As indicated in Table 4-14, a potential for overlap exists between EGU and non-EGU sector projects. As
indicated by the estimated number of SCR/SNCR applications per vendor in Table 4-14, for large-scale
SCR systems, the estimated 5 to 16 SCR retrofits for EGUs could be addressed by a vendor pool of at
least nine identified by EPA. We do not display optimizations in the table below because EPA expects
that many of these optimizations can be accomplished through in-house labor and in a relatively short
time period (about 2 months based on past experience). Additionally, these optimizations are expected
to occur by the 2023 ozone season.
111 EPA "Appendix A: Final Rule State Emission Budget Calculations and Engineering Analytics" of Ozone Transport
Policy Analysis Final RuleTSD.
41
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Table 4-14. Estimated Demand for SCR or SNCR Projects by 2026
Large-
Small-
SNCR/
Parameter
Scale SCR
Scale SCR
ASNCR
Applications
Equipment Vendors
9
14
9
per Vendor
Estimated Applications
EGU SCR (~2.5 - 8 GW by 2027)
5-16*
~0.5-2
Affected Industry Boiler SCR Installs
15
~1
Cement Kiln SNCR Installs
16
~2
MWC SNCR/ASNCR Installs
61
~7
*Based on an assumed nominal 500 MW average unit capacity.
For small-scale SCR applied to non-EGU boilers, the applications per vendor presume that only the
remaining small-scale SCR vendors are the available pool of suppliers (i.e., that large system providers
are not interested in systems of that scale). This results in only around 1 application per vendor. Total
non-EGU SNCR/ASNCR applications per vendor total 9. Over a 3-year period, this suggests that each
vendor might have around 3 applications per year, which is within the typical capacity constraints
suggested during vendor contacts.
We find that there are at least nine companies offering SNCR systems in the US (see Appendix A).
Between EGU SNCR optimizations and non-EGU SNCR installations, the average number of applications
per vendor is 13. Spread across 2 years (assuming another year for initial studies and permitting as
mentioned in earlier in Section 4), this average becomes 7 per vendor per year. However, as noted
above, a majority of the EGU SNCR optimizations are not expected to require vendor support, so the 7
applications per vendor per year is likely a maximum estimate, with a more likely estimate being 4
applications per vendor per year if the EGU optimizations are excluded. Note that the MWC applications
will likely be drawing from a smaller pool of vendors than the 9 indicated, however. This is because not
all SNCR vendors will have the expertise with MWCs (including those that have designed and installed
ASNCR). Therefore, MWC SNCR installs may have an increased risk for supply chain delays associated
with sourcing the skilled labor required to meet a May 2026 deadline.
Note that compact SCR and NSCR applied to RICE are not addressed in Table 4-14, since those are
supplied primarily by a different set of vendors than the larger EGU and non-EGU systems. As indicated
previously, the number of vendors for those systems appears to be sufficient based on vendor
discussions.
4.6 Permitting Processes
As shown in Table 4-1, the typical time needed to obtain construction and operating permits for non-
EGU NOx control installations is estimated to be 3-6 months for some industry/control source
combinations and 6-12 months for other, more complex permits (e.g., SCR or SNCR). The Table 4-1
estimates of the amount of time required for permit reviews included in the installation timelines is
conservative (that is, overstated), so that complex permitting issues can be addressed, where needed.
This section provides an analysis of the permitting load that could occur by state based on the number
and type of control installations estimated in each state. This informs our assessment of whether the
permitting load in any covered state might overwhelm existing permitting staff and pose a risk of delay
in control installations.
42
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For states that have permitting programs that allow for expedited review, the permitting processes may
be less of a concern. Especially in situations where emission reductions from existing sources are
involved (rather than new sources of emissions), minor permit revisions can often be granted within 8
weeks if not sooner.112
A key permitting issue for any control installation is whether the change to the source is considered a
minor or major modification to the existing permit. Installation of a NOx control will not always trigger
substantive permit reviews. For example, if a combustion control retrofit kit is being installed on a RICE
and does not lead to any increase in emissions, the owner/operator may only need a minor permit
modification. Installation of a NOx control device that results in a significant increase in emissions of
another regulated pollutant, however, would constitute a major modification to the source requiring a
lengthier major NNSR or PSD permitting process.
Contacts with permitting agency staff in several states provided the following information relevant to
estimating the timelines needed for non-EGU sources to obtain the permits necessary to comply with
the final rule:
• Louisiana: Minor permit revisions take about 40 hours. Louisiana Department of Environmental
Quality's current staffing includes 46 permitting staff.113
• Texas: The Texas Commission on Environmental Quality (TCEQ) has around 90 permitting
staff,114 and has a target of completing operating permit modifications within 120 days.115 The
number of ongoing permitting projects in Texas are 974, and the state is keeping up with the
current workload based on information available for this report.
• Oklahoma: Permitting staff indicated that their estimate of affected units was 109, and that
these were located at around 40 facilities.116 The Oklahoma Department of Environmental
Quality currently has 15 permitting staff and three open positions.
Table 4-15 provides a summary of the estimated number of non-EGU NOx control installations by
state.117 The controls are broken out by large add-on controls (SCR or SNCR) and other NOx controls. The
latter include NSCR and compact SCR applied to RICE and combustion controls (layered combustion,
LNB, LNB + FGR). The number of control installations were broken down into these two categories since
112 B. Johnston, Louisiana Department of Environmental Quality (LDEQ), personal communication with S. Roe,
SC&A, Inc., October 25, 2022. Based on the number and type of affected units, LDEQ felt confident that ATCs could
be issued in a timely manner that would not impact an operator from meeting the compliance schedule indicated
in the proposed rule.
113 B. Johnston, Louisiana Department of Environmental Quality (LDEQ), personal communication with S. Roe,
SC&A, Inc., October 25, 2022. Based on the number and type of affected units, LDEQ felt confident that ATCs could
be issued in a timely manner that would not impact an operator from meeting the compliance schedule indicated
in the proposed rule.
114 S. Short, Acting Director, Office of Air, Texas Commission on Environmental Quality, personal communication
with S. Roe, SC&A, Inc., October 31, 2022.
115 This target is for the alteration of a new source review permit. TCEQ also mentioned a target of 330 days for
revision of a general operating permit or 365 days for revision of a site operating permit. Source: Short, S. Acting
Director, Office of Air, TCEQ, personal communication with S. Roe, SC&A, Inc., October 27, 2022.
116 L. Warden, Engineering and Permitting Group Manager, OKDEQ, personal communication with S. Roe, SC&A,
Inc., October 24, 2022.
117 EPA, Office of Air Quality Planning and Standards, "Non-EGU Unit Results - Scenarios - 12-01-2022.xlsx."
43
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large add-on controls may require more time by permit reviewers than combustion controls or packaged
add-on controls.
Table 4-15 also includes an indication of whether a state has an expedited permit review process
available. Most state expedited permitting programs allow a source operator to pay an additional fee to
have their permit or permit revision processed on an expedited manner. Additionally, some states have
other requirements for expedited review, such as the unit owner or operator being a member of an
environmental stewardship program.
Finally, Table 4-15 provides an estimate of the incremental state permitting staff load that might result
from the non-EGU controls needed to comply with the final rule. This is estimated in terms of annual
staff full time equivalent (FTE) hours, with 2,000 hours assumed to be a typical FTE workload per year.
The state incremental FTE permitting load is calculated as 400 hours per major modification (based on
the information provided by Minnesota)118 and 40 hours per minor modification (based on the
information provided by Louisiana), with each multiplied by the number of expected units needing
permits in each category. The resulting total incremental permit hour burden is divided by 2,000 hours
per FTE and by 2 years, since there will be approximately 2 years during which these permits might be
processed.
Table 4-15. Estimated Non-EGU NOx Control Installations by 2026 by State
Other NOx
State
SCR/SNCR
Controls
Estimated
(Expedited
(Major
(Minor
AnnualFTE
Program?)
Modification)
Modification)
Total
increment*
Arkansas (N)
2
32
34
0.5
California (Y)
6
7
13
0.7
Illinois (Y)
0
61
61
0.6
Indiana (Y)
7
44
51
1.1
Kentucky(Y)
0
48
48
0.5
Louisiana (Y)
4
195
199
2.4
Maryland (N)
0
2
2
0.0
Michigan (N)
3
58
61
0.9
Mississippi (N)
0
63
63
0.6
Missouri (N)
1
39
40
0.5
New Jersey (N)
10
1
11
1.0
New York (N)
18
12
30
1.9
Ohio (N)
2
108
110
1.3
Oklahoma (N)
9
126
135
2.2
Pennsylvania (N)
21
66
87
2.8
Texas(Y)
1
176
177
1.9
Utah (N)
0
6
6
0.1
Virginia (N)
8
29
37
1.1
118 Sources in Minnesota were included in the proposed rule, but not in the final rule.
44
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Other NOx
State
SCR/SNCR
Controls
Estimated
(Expedited
(Major
(Minor
AnnualFTE
Program?)
Modification)
Modification)
Total
increment*
West Virginia (N)
0
63
63
0.6
Totals
92
1,136
1,228
21
*Estimated as 400 hours per major modification, 40 hours per minor modification, with
2,000 hours per FTE per year, and with 2 years available.
With the number of staff present in Louisiana, the Table 4-15 incremental FTE of 2.4 represents about a
5% increase in workload. We anticipate that this incremental workload increase can be accommodated
in Louisiana. Note this number of affected units represents an upper end to the number of permit
modifications needed to support the rule as some sources may have more than one affected unit and
will likely seek permit modifications for them at the same time.
Even though the number of estimated NOx control installations for Texas is high, a large fraction of
these is for controls on natural gas-fired compression engines (RICE). TCEQ staff has indicated it can
address the expected increase in permit workload for non-EGUs.119 Assuming that the bulk of permits
need to be processed within a two-year period, roughly a 2% increase in permit staffing workload, or a
9% increase in ongoing permit workload is estimated to result from the final rule. We anticipate that this
incremental workload increase can be addressed.
In Oklahoma, it appears there may be an incremental increase in permit review labor associated with
permit modification reviews of around 12 to 15% (depending on whether Oklahoma has 15 or 18
permitting staff). Oklahoma permitting staff could face a relatively higher permitting load on a per-FTE
basis. However, as in Texas, many of the units in Oklahoma are RICE and thus not likely to trigger major
modification review.
Available time and resources did not allow for permitting staff levels to be collected from each affected
state to conduct similar assessments to the analyses above for Louisiana, Texas, and Oklahoma. Based
on the state-specific assessments above, all of the incremental FTE estimates associated with permitting
appear to be manageable, as all are less than 3 FTE per year. Thus, no additional delays are attributed
to permitting beyond the standard timeframe needed for permitting as listed in Table 4-1.
Note that the permitting load from EGU controls was not included in this assessment, as only a handful
of NOx retrofit controls (beyond optimizations of existing controls) are expected in compliance with the
final rule by 2026. As indicated in Section 4, the total number of expected EGU SCR retrofits and
combustion control installs is estimated to be between 15 and 50. Spread across all states affected by
the rule, the incremental permitting workload is expected to be small. In addition, we anticipate that the
vast majority of EGU SCR/SNCR optimizations will be completed in-house with operational changes that
will not affect the operation of the existing control equipment. Rather, the operational changes will be
mainly increased maintenance, changes to combustion unit operation, or changes in EGU dispatching
(that maintain exhaust at optimal temperatures for control operation). It is assumed that these
119 S. Short, Acting Director, Office of Air, Texas Commission on Environmental Quality, personal communication
with S. Roe, SC&A, Inc., October 31, 2022.
45
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operational changes are all within the conditions of the existing operating permit and no revisions
be required.
46
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5. Potential for Supply Chain Delays and Constraints
S.lSupply Chain Concerns
Supply chain concerns can be organized into the following three phases of control equipment
installation:
1. Producer constraints in raw materials and control equipment component production. Raw
materials include bar and plate steel and catalyst components. Note that bar and plate steel
products are manufactured by an industry addressed by the final rule.
2. Shipping delays for raw materials and components (especially imported components).
Examples of control equipment components are pumps, nozzles, fans, motors, and electronic
controllers.
3. Constraints in the skilled labor pools involved in control equipment design, fabrication, and
installation. Depending on NOx control type and application, the skilled labor pool could include
the initial system modelers and equipment designers, equipment fabricators, control equipment
installers, and other local construction trades needed for control installation (e.g., equipment
foundations, structural supports).
Producer constraints in raw materials and control equipment components were identified as concerns
by both commenters and control equipment vendors. One of the raw materials of concern was catalyst
material for SCR systems (including oxides of base metals and various precious metals). As described in
Section 4.4, while there are overlapping needs for catalyst material for both the EGU and non-EGU
sectors, EPA expects that the incremental demands will be small, and that additional catalyst material
will be available for recycling due to recent and ongoing EGU retirements.
Based on input from control equipment vendors, demand constraints brought on by the pandemic for
bar and plate steel and equipment components (e.g., nozzles, pumps, fans, controllers) were easing in
the final quarter of 2022. Vendor expectations are that any remaining producer constraints will resolve
during 2023. Also, based on November 2022 statistics presented below (Figure 5-1) from the Bureau of
Transportation Statistics, business inventories are trending back toward pre-pandemic levels.
Statistics presented below also indicate that shipping delays that occurred during the pandemic are
abating (Figures 5-2 through 5-8). These include statistics on shipping, truck activity and more
generalized supply chain indices.
Available statistics for the skilled labor pools needed for control equipment fabrication indicate a high
level of capacity utilization for the US, especially for the fabricated metals sector which includes
manufacturers involved in constructing many add-on controls (Figure 5-9). Other fabricators in Canada
and Mexico are also commonly used by US control equipment vendors. While the data for Mexico are
not presented at the same level of detail as the US statistics, they indicate high levels of capacity
utilization in the manufacturing sectors of both countries (Figures 5-10 and 5-11). This supports
feedback from some equipment vendors about long lead times (> 12 months) experienced during 2022.
Section 5.2 below addresses the potential for constraints in local installation labor. These are the
specialty contractors that might be needed for construction of large add-on controls, such as SCR or
SNCR. As indicated by those statistics, some states have still not recovered in terms of employment
47
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levels of specialty contractors. Although the number of large add-on controls for the non-EGU sector is
small as addressed elsewhere in this report, these statistics indicate that there could be some localized
challenges in sourcing installation labor. However, no analysis was undertaken of the capacity for labor
mobility for control installation projects.
Information gathered to characterize each of the three areas of supply chain concern and related
comments are summarized below.
Potential Producer Constraints for NOx Control Equipment Components and Associated Raw Materials
Comments were due on the proposed rule by June of 2022, and so commenters discussed their
experience or perception of these supply-chain issues as of that time period. As discussed further below,
recent economic indicators suggest some of these concerns are ameliorating.
In their comments on the proposed rule, CI BO noted current delays in the delivery of specialized parts
for SCR systems (which may also affect other control types). These include variable frequency drives,
programmable logic controllers, and ammonia pumps.120 The lead time for variable frequency drives was
cited as being around 1 year as compared to a year ago (from when these comments were submitted)
when these drives were available off the shelf or had a lead time of around 1 month. Similarly, according
to this commenter, typical lead times for ammonia pumps were 18 months in the pre-Covid era but
were around 24 months at the time the comment was submitted.
Control equipment vendors have also reported delays in components that are typically imported:
electronic control equipment, nozzles, and pumps. Many of these parts are imported from Asia
(especially Taiwan and China). However, the situation seems to be improving, and one vendor expected
that the supply delays may be resolved sometime in 2023.
The Utah Petroleum Association/Utah Mining Association commented that lead times for combustor
and controller parts had increased from 40 weeks to 80 - 120 weeks, as of the time the comment was
submitted.121 They also commented that skilled labor shortages are expected, especially in rural areas.
The commenter also mentioned that more NOx reductions and other environmental benefits could be
obtained by extending electricity system distribution, so that electrification could become a compliance
option.
The Associated General Contractors of America commented that current lead times for procurement of
certain construction materials could impact the timelines for various industries subject to the proposed
rule.122 Examples mentioned were six-month lead times for fittings used in water supply systems and
lead times of over a year for aluminum used in metal fabrication of bridges. Some of these construction
materials would also be used to support large NOx control systems.
Regarding component supplies from U.S. manufacturers, Figure 5—1 below shows the inventory to sales
ratio for US business through September 2022.123 These data from the Bureau of Transportation
120 EPA-HQ-OAR-2021-0668-0362. Comment submitted by Council of Industrial Boiler Owners (CIBO).
121 EPA-HQ-OAR-2021-0668-0378. Comment submitted by Utah Petroleum Association (UPA) and Utah Mining
Association (UMA).
122 EPA-HQ-OAR-2021-0668-0415. Comment submitted by Associated General Contractors of America (AGC).
123 Bureau of Transportation Statistics (BTS), Latest Supply Chain Indicators, website at
https://www.bts.gOv/freight-indicators#labor. The ratio of total inventory at retailers, wholesalers, and
48
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Statistics (BTS) indicate that business inventories are improving relative to 2021; however, inventory
levels have still not yet returned to pre-pandemic levels (2019).
Total Business: Inventory to Sales Ratio: , 2020,2021,2022
November 2022 (monthly)
Jan Apr Jul Oct Jan
Notes: The ratio of total inventory a! retailers, wholesalers, and manufacturers, divided by total sales. Data on inventory and sales are based on Census
Bureau surveys. Data adjusted for seasonal, holiday and trading day differences but not for price changes-
Source: U.S. Census Bureau, Total Business: Inventories to Sales Ratio
Figure 5-1. US Inventory to Sales Ratio
Shipping Delays for Raw Materials and Control Equipment Components
National indicators of shipping constraints from BTS indicate a mixed picture of economic recovery
following the pandemic. Figure 5-2 shows that the number of container ships awaiting berth at US ports
has improved somewhat over the past year at two of the four ports reported; however, overall, the
number of ships remains high (about 90 at all US ports) with only a small reduction overall in the past
year.
manufacturers, divided by total sales. Data on inventory and sales are based on Census Bureau surveys. Data
adjusted for seasonal, holiday and trading day differences but not for price changes.
49
-------
8/1/21 10/1/21 12/1/21 2/1/22 4/1/22 6/1/22 8/1/22 10/1/22
Notes: LA-LB totals include containerships in drift/holding areas. Data reported at more frequent intervals starting October 18, 2021
Source: MARAD Office of Policy and Plans/Marine Exchange of SoCal
Figure 5-2. Containerships Awaiting Berth
For truck freight activity, the BTS data in Figure 5-3 below show that truck travel activity has returned to
pre-pandemic levels. The BTS freight transportation services index through September 2022 shown in
Figure 5-4 also indicates that services have recovered to near or above 2019 levels.
50
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Interstate Vehicle Miles Traveled: Percent Change from 2019
July 31, 2022 (weekly)
30
j All Vehicles
Passenger Vehicles
I Trucks
12/01/19 03/01/20 06/01/20 09/01/20 12/01/20 03/01/21 06,101/21 09/01/21 12/01/21 03/01/22 06/01/22 09/01/22
Source: TMAS Data, Office of Highway Policy Information. FHWA
Figure 5-3. Interstate Vehicle-Miles Traveled (% Change from 2019)
Freight Transportation Services Index: , 2020, 2021,2022
September 2022 (monthly)
J F M A
Source: Bureau of Transportation Statistics
N D
Figure 5-4. Freight Transportation Services Index
51
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While the indicators above show that the transport of goods has largely returned to more normal levels,
Figure 5-5 below shows another BTS indicator on the volume of imported goods, which is now well
above pre-pandemic levels. Hence, there still seems to be strong potential for more freight delays for
imported goods, although the imported goods appear to be heading back to more historic or normal
levels.
U.S. Goods Imports Indexed (Feb. 2020= 100)
September 2022 (monthly)
130
125
120
115
110
105
100
95
90
Apr-2017 Oct-2017 Apr-2018 Oct-2018 Apr-2019 Oct-2019 Apr-2020 Oct-2020 Apr-2021 Oct-2021 Apr-2022 Oct-2022
Source: U.S. Census Bureau, Seasonally Adjusted Real Imports by Principal End-use Category
Figure 5-5. Index of US Imported Goods
Control equipment vendors have reported quotes from metal fabricators with significant lead times of
up to a year for items such as electrical components (e.g., controllers) and valves. Typical lead times
previously would have been 18 to 20 weeks. These reports are consistent with the supply chain
indicators above on business inventories (such components need to be manufactured, rather than
pulled from existing inventory).
Another sign that supply chain bottlenecks may be in the process of being resolved is illustrated by the
recent RSM US Supply Chain Index.124 Figure 5-6 below shows that the index just returned to a positive
value for the first time in over two years. This index is a composite of ten subindices, which are shown in
Figure 5-7. In particular, the subindices associated with inventory levels from manufacturers to retailers
are above historical levels and the other subindices are all improving.
124 The Real Economy Blog, RSM U.S. Supply Chain Index: Back to normal for first time since pandemic hit, website
at https://realeconomy.rsmus.com/rsm-u-s-supply-chain-index-back-to-normal-for-first-time-since-pandemic-hit/.
52
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RSM US Supply Chain Index
Z-score based on mean and standard deviation from 2001 to 2019
1
0
-1
-2
-3
-4
Recession
2003 2005 2007 2009 2011
te of zero ts defined as a normal level of supply chaii
gest deficiencies Source Various government & pri
2013 2015 2017 2019 2021 2023
ciency Positive values of the index suggest adequate levels
organizations. Bloomberg, RSM US
Figure 5-6. RSM US Supply Chain Index
Subindex component tracker
Z-score based on mean and standard deviation from 2001 to 2019
Scales
-8 8B
16 5
2021 2022
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Jan Feb Mar Apr May Jun Ju« Aug Sep Oct Nov Dec Jan Feb Mar Apr May Jun JxM
ISM Mfg delivery time 02 4)4.36^-5 2 * • : • 4 1 s .< 4 m S8|04l4-#9 t • -fl t .«* ? -t 6 -35 -2 6 14
ISMMfg pncespari 04 09 14 1 1 09 01 04 -0.3 -01 -05 -06 -1 1-12 18 1 9 22 24 25 -24 18 2 1 25 24 19-21 22 -26 -26 24 -21 -09
levels 06 03-I S-04 >021 18 0 1-12 04 07 01 15 0 1 1 $ 08 04 05 03-01 01 02-03 06 02 04 07 1 1 0 7 10 05 03
02 0.0 -02 -02 -03 -03 -05 -06 4)7 -0 7 -06 -06 -06 433 4) 1 -02 00 01 03 04 06 07 06 06 07 06 08 09 10 09 10
ISM Mfg inventory
Real ntfg inventories*
Real retail inventory* 4>.8 *1.0-06-1 4 «2.9-3 5-3 4 3.2 -2 8 ? 5 -2 1 -1 8 -1 7 -1 6 *23
Real vrfholesale inventory* -0 9 -12 -1 3 -13-16 -1 8-19 18-16 -13 -12 -12 -0 8 -04 -02
Inventory-sales rabo 15 14 2 7 H 38 14 06 0 4 0 4 0 4 06 0 2 -04 01 -10
Capacity ubteation 00 0 1-09 ^2-38 24 -15-1 2-1 2-1 0-08-05-02-09 4)2
Job vacancy rale* 18-17 -09-05-10-14-18 16-17-20 -20 -20-2 2 -28 -3 2
Intermodal freight traffic -1 1 -10 -2 2 -28 -2 2 -1 2 -0.5 0 1 0 7 10 13 1 1 16 -0 6
2.1 10 -02 -03 4)5-10-14 11 -04 4)1 02 14 21
02 02 06 09 10 1 1 13 15 19 18 22 J
1.2 -10 -12 -12 -10 -10 -12 -12-07-10-10 -0 9 4) 7 -0 6 4) 6 4)6
-01 01 02 04 0 4 0 2 06 07 06 0 7 08 10 1 1 1 1 10 1 1
2 0.1 4)8 -1 3-14 -1 7 -16-2.3 0 1-1 3 -14 -10 -10 4)8
Figure 5-7. RSM US Supply Chain Subindices
Figure 5-8 is a chart of the global supply chain pressure index produced by the Federal Reserve Bank of
New York.125 It also indicates that, at a global level, supply chain linkages are being re-established and
125 Federal Reserve Bank of New York, Global Supply Chain Pressure Index (GSCPI), website at
https://www.newyorkfed.Org/research/policy/gscpi#/interactive. The GSCPI integrates several commonly used
53
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pressures reduced. However, supply chain pressure is near historically high levels. While there are good
signs both in the US and at the global level for reduced supply chain disruption, it is still too early to
know whether the supply chain issues noted by equipment vendors will resolve entirely in the coming
years.
Standard deviations from average value From May 18,2012 To Nov 30,2022
6
-3
2013 2015 2017 2019 2021
Figure 5-8. Global Supply Chain Index
Skilled Labor Constraints for Equipment Design. Fabrication, and Installation
Based on the potential number of NOx control installations for both the non-EGU and EGU sectors, the
following non-EGU technologies and applications appear to be competing for limited skilled labor pools:
• SCR applied to ICI boilers;
• SNCR applied to cement kilns and MWCs; and
• Combustion controls applied to natural gas compressor station RICE.
Each of these constraints is addressed within a broader discussion of skilled labor constraints in this
section.
SCR on ICI Boilers; and SNCR on Cement Kilns and MWCs. Some control equipment vendors offering
SCR might also offer SNCR. These smaller non-EGU NOx sources may experience delays in contracting for
equipment design, fabrication, and installation, since vendors may tend to focus on larger and likely
more profitable contracts first.126 For example, MWC units are often smaller than EGUs (usually less than
30 MW of capacity), and some commenters indicated that they would be competing for the same
control equipment vendors. As described above in Section 4.5, there is a pool of SCR/SNCR vendors that
service the EGU sector, and those vendors may not be inclined to bid on projects at these smaller scales.
Those vendors will also likely be servicing the needs of EGUs with existing SCR systems that are
optimizing those SCR systems for rule compliance. For both SCR and SNCR systems for these groups of
affected non-EGU sources, it appears that a different set of equipment vendors would be serving them
metrics with the aim of providing a comprehensive summary of potential supply chain disruptions. Global
transportation costs are measured by employing data from the Baltic Dry Index (BDI) and the Harpex index, as well
as airfreight cost indices from the U.S. Bureau of Labor Statistics. The GSCPI also uses several supply chain-related
components from Purchasing Managers' Index (PMI) surveys, focusing on manufacturing firms across seven
interconnected economies: China, the euro area, Japan, South Korea, Taiwan, the United Kingdom, and the United
States.
126 EPA-HQ-OAR-2021-0668-0301. Comment submitted by Minnesota Resource Recovery Association (MRRA).
54
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as compared to the much larger EGU sources (at least from a design perspective). Based on the
assessment in Section 4.5, it appears that competition for skilled labor is more likely to be an issue
during equipment fabrication and installation phases. For example, large EPC contractors may provide
the overall design and engineering of an SCR system but use subcontractors to fabricate and install
equipment.
Control Equipment Fabrication Constraints. The comparisons of labor requirements above only include
the US boilermaker occupation. Some of the labor needs might be supplied by other workers in aligned
industries. These include metal fabrication, machinery, and construction. Local construction labor
constraints are addressed below. For metal fabrication and machinery, Figure 5-9 below provides
historic data through August 2022 of U.S. capacity utilization in these sectors, along with all
manufacturing. As indicated by these data, since 2000, capacity utilization does not tend to peak much
above 80%. Current levels of capacity utilization have increased well above their levels following the
start of the pandemic. Overall manufacturing capacity stood at 79.6% at the end of August 2022. This
compares to the average of 75.3% going back to 2000, and a maximum monthly value of 80.5%. For
fabricated metals, the current value of 79.0% compares to a long-term average of 77.6% and a
maximum value of 87.8%. For machinery, the current value is 83.5% compared to a long-term average of
75.4% and a maximum of 86.6%.
100
90
SO
70
60
g? 50
40
30
20
10
0
US Manufacturing Capacity Utilization
cf* O* C?y rv* A fN f\y <\V A r(V r-N A rCv fN A
Cv cr cr o.v cr c>v $y cr £¦
• Manufactur'ne
F ab ricaced M etal Pro ducts — — — M achinery
Figure 5-9. US Manufacturing Capacity Utilization127
It is important to note that equipment vendors have indicated that they draw support from fabricators
throughout North America (including Canada and Mexico). Figure 5-10 presents a chart of Canadian
manufacturing capacity that is similar to Figure 5-9 shown above for the U.S. The Canadian data indicate
a similar situation as the U.S. for available capacity. The most recent data cover the second quarter of
127 Board of Governors of the Federal Reserve System, Industrial Production and Capacity Utilization - G.17,
website at https://www.federalreserve.gov/releases/gl7/current/tablel.htm.
55
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2022. Overall manufacturing and fabricated metals capacity are slightly below their long-term averages
(back to the year 2000). Machinery capacity is slightly above the long-term average.
Canadian Manufacturing Capacity Utilization
100
3? 50
40
BO
20
10
0
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Figure 5-11. Mexican Manufacturing Capacity Utilization129
Constraints on Local Construction Labor. Specific to construction labor that could be involved in the
installation of large air pollution control systems, such as SCR and SNCR, Figure 5-12 below indicates that
nonresidential construction employment in the U.S. has still not recovered to pre-pandemic levels (still
3% below levels in February 2020).130 A regional assessment of demand and supply of labor is provided
in Section 5.2 below.
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-------
Skilled labor for Installation of Controls for External Combustion Sources. One example of an analysis
of impact to skilled labor necessary to install air pollution control equipment is the analysis EPA
conducted in 2005 of boilermaker employment in the US, and its availability to address NOx and S02
control installations for the final Clean Air Interstate Rule (CAIR).131 Note that the Bureau of Labor
Statistics (BLS) defines boilermakers as follows:132
Construct, assemble, maintain, and repair stationary steam boilers and boiler house auxiliaries.
Align structures or plate sections to assemble boiler frame tanks or vats, following blueprints.
Work involves use of hand and power tools, plumb bobs, levels, wedges, dogs, or turnbuckles.
Assist in testing assembled vessels. Direct cleaning of boilers and boiler furnaces. Inspect and
repair boiler fittings, such as safety valves, regulators, automatic-control mechanisms, water
columns, and auxiliary machines.
Although the boilermaker labor category closely addresses the skilled labor pool that could be involved
in air pollution control installation, we note that a much broader group of trades people are involved in
the fabrication and installation of air pollution controls, such as SCR systems. For example, these include
contracted metal fabricators that build the housing and ducting of SCR systems, electricians for installing
control and monitoring systems, and local construction contractors that build and install the structural
components to mount the new SCR system. Many of these skilled trades people would not be included
in the BLS estimates of boilermakers. However, extracting employment estimates for all segments of
these skilled trades aligned with the air pollution controls industry and related equipment/services is not
possible. Thus, using boilermaker employment is a conservative surrogate for the full complement of
skilled trades involved.
The key inputs to EPA's 2005 boilermaker labor analysis were:
• Boilermaker population: 28,000
• Percentage of boilermaker labor available for CAIR retrofits: 35%
• Number of annual hours worked by a boilermaker: 2,000 hours/year
• SCR duty rate: 0.175 year/MW (annual boilermaker labor per unit of EGU capacity)
Recent BLS employment estimates for boilermakers (May 2021) indicate a significant contraction for the
occupation to 12,920.133 EPA noted in 2005 that BLS was forecasting lower boilermaker employment due
to both lower demand and an accelerated retirement rate among the aging workforce. This employment
estimate and the previous labor analysis inputs above provide an annual available boilermaker labor
supply estimate of 12,920 x 0.35 x 2,000 hours/yr = 9,044,000 hours/year.
Note the key assumption in the analysis above that 35% of the workforce is still considered available for
control retrofits. Given the apparent contraction for the boilermaker occupation, that value may be
131 EPA, Office of Air and Radiation, "Technical Support Document for the Final Clean Air Interstate Rule,
Boilermaker Labor Analysis and Installation Timing," Docket ID No. OAR-2003-0053, March 2005.
132 U.S. Bureau of Labor Statistics, Occupational Employment and Wages, May 202147-2011 Boilermakers, website
at https://www.bls.gov/oes/current/oes472011.htm#(l).
133 U.S. Bureau of Labor Statistics, Occupational Employment and Wages, May 202147-2011 Boilermakers, website
at https://www.bls.gov/oes/current/oes472011.htm#(l).
58
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overstated.134 On the other hand, while it is not clear from the 2005 technical memo, the SCR duty rates
are likely based on estimates from large coal-fired power plants. Since the affected non-EGU boilers are
likely to be smaller, the SCR systems would also be smaller and potentially much less labor intensive to
install. For non-EGU sources, EPA estimated 15 SCR systems (excluding compact SCR units for RICE)
would be installed on industrial boilers.135 There are no SCR duty rates available for non-EGUs as there
are for EGUs. For a rough gauge of the fabrication and installation labor requirement for SCRs for non-
EGUs, the following assumptions were made:136
• SCR is being retrofitted to a 250 MMBtu industrial oil/gas boiler;
• EPC vendor percentage of total project cost is 20% (design, procurement, and construction
management);
• Fabrication and installation labor percentage of total project cost is 40%; and
• The loaded average fabrication and installation labor rate is $70/hour.
EPA's SCR Cost Manual Spreadsheet137 was used to generate a total capital cost for the project ($8.63
million in 2022 dollars). This value is assumed to be representative of the average for all non-EGU SCR
installations. Application of the assumptions above to the estimated capital cost resulted in a
fabrication/installation labor estimate of 39,400 hours. Applying this value to the 15 estimated non-EGU
SCR systems (again, excluding compact SCR units for RICE) yields 0.6 million labor hours. Based on the
available boilermaker labor estimate above, this load could be absorbed relatively easily. Note this does
not account for the boilermaker labor that might be needed for non-EGU SNCR applications and EGU
SCR/SNCR optimizations.
Skilled Labor for Combustion Controls on Natural Gas Transmission Compressor RICE. In their
comments, TC Energy cited previous EPA rulemaking estimates that only about 75 engines could be
retrofit annually on a sustained basis given resource constraints (skilled labor) and the time needed to
procure and install equipment. TC Energy referenced a 2014 report by INGAA, t which is the source of
the 75 engines per year estimate.138 A number of commenters representing this industry concluded
that decades would be needed to address all RICE addressed by the rule. An example cited was the
conversion of over 200 natural gas transmission RICE to add Low Emissions Combustion beginning in
1999 as part of the NOx SIP Call. The entire retrofit process took six years according to the commenters.
134 Discussions with SCR vendors indicate that metal fabricators are currently constrained across North America
(includes, US, Canadian and Mexican suppliers).
135 U.S. EPA. Technical Memorandum. Summary of Final Rule Applicability Criteria and Emissions Limits for Non-
EGU Emissions Units, Assumed Control Technologies for Meeting the Final Emissions Limits, and Estimated
Emissions Units, Emissions Reductions, and Costs. March 15, 2023.
136 These assumptions are based on discussions with control equipment vendors, BLS labor statistics (U.S. Bureau
of Labor Statistics, Occupational Employment and Wages, May 202147-2011 Boilermakers, website at
https://www.bls.gov/oes/current/oes472011.htm#(2)), and industry wage/benefits information (Boilermakers
Union Local 242, Wages & Benefits, website at https://boilermakers242.com/wages-benefits/).
137 EPA, Cost Reports and Guidance for Air Pollution Regulations, website at https://www.epa.gov/economic-and-
cost-analysis-air-pollution-regulations/cost-reports-and-guidance-air-pollution.
138 Interstate Natural Gas Association of America (INGAA), "Availability and Limitations of NOx Emission Control
Resources for Natural Gas-Fired Prime Movers Used in the Interstate Natural Gas Transmission Industry," prepared
by Innovative Environmental Solutions and Optimized Technical Solutions, INGAA Foundation Final Report No.
2014.03, July 2014.
59
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Multiple commenters referenced INGAA's estimated limit of 75 RICE retrofits per year based on the size
of the skilled labor pool for such retrofits.139 Although state-level data were not provided in these
comments, INGAA estimated that most control retrofits would be directed at 2,050 two-stroke engines
(this includes engines in 40 states and was thought to be ~80% complete at the time). INGAA pointed
out that the 75 retrofits/year estimate compared to 50 retrofits/year carried out earlier during the NOx
SIP Call.
The estimate of 75 retrofits per year provided by INGAA is now about 10 years old. INGAA also noted in
its report that this estimate was based on current resource availability and did not take account of hiring
and training to respond to a new regulations. A skilled labor pool has likely already grown given the
extent of retrofits over the previous years to service the growing size of the current storage and
transmission industry. In addition, there has been a significant expansion in RICE used for other
applications, including backup power for data centers. Therefore, the skilled labor pool for engine
retrofits should have grown with the size of the RICE population. Considering just the growth in natural
gas production, which in the US has nearly doubled since 2005 (as indicated in the Figure 5-13 below), a
skilled labor pool should be present to support the retrofits in the industry. Assuming that the size of the
skilled labor pool has grown along with natural gas production and RICE-use expansion and would
continue to grow in response to a regulatory mandate as INGAA acknowledged in their report, this
would allow for a reasonable estimate that the size of the labor pool with the requisite skills could be
doubled from the prior estimate and thus would be large enough to conduct 150 specialized retrofit
installations per year (75 retrofits/yr x 2). Using EPA's estimate of 905 affected engines for the final rule
as a very conservative upper-bound estimate for the number of units that may require such specialized
labor, the maximum amount of time to apply the retrofit controls to this estimated number of engines
would be just over 6 years (a lower upper-bound figure of 717 engines would reduce the time estimate
accordingly).
139 Interstate Natural Gas Association of America (INGAA), "Availability and Limitations of NOx Emission Control
Resources for Natural Gas-Fired Prime Movers Used in the Interstate Natural Gas Transmission Industry," prepared
by Innovative Environmental Solutions and Optimized Technical Solutions, INGAA Foundation Final Report No.
2014.03, July 2014.
60
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U.S. Natural Gas Marketed Production ^ download
Million Cubic Feet
40,000,000
30,000,000
20,000,000
10,000,000
0 I I i~ 1 1 1 1 1 1 1 1 1 1—
1900 1910 1920 1930 1940 1950 1960 1970 1980 1990 2000 2010 2020
— U.S. Natural Gas Marketed Production
Figure 5-13. Historic US Natural Gas Production140
From a skilled labor perspective, industry commenters seemed to be most concerned about the
population of RICE engines that were very old (>50 years). The concern is that there is a limited skilled
labor pool that has the experience working with RICE of that vintage. In situations where the control is
LC, rather than an add-on control, skilled mechanics would be needed. The data supplied to EPA on
affected RICE and that are estimated to adopt LC does not include the age of the equipment.
5.2 Regional Analysis of Demand and Available Supply of Labor
For the purposes of examining regional labor constraints, to the extent they may exist, the metrics of
most interest are those that address state-level construction labor that could be involved in the local
installation of NOx controls, in particular, larger SCR and SNCR systems. Design and equipment
fabrication could occur locally, however, in most cases, these services might come from suppliers
outside of the region.
Figures 5-14 through 5-17 provide state-level summaries of employment within the Specialty Trade
Contractors category from 2005 through October of 2022.141 The state-level summaries provided
represent the states with the greatest number of estimated non-EGU controls installations. BLS defines
the Specialty Trade Contractors subsector as comprising establishments whose primary activity is
performing specific activities (e.g., pouring concrete, site preparation, plumbing, painting, and electrical
work) involved in building construction or other activities that are similar for all types of construction,
but that are not responsible for the entire project. The work performed may include new work,
additions, alterations, maintenance, and repairs. The production work performed by establishments in
this subsector is usually subcontracted from establishments of the general contractor type or operative
builders, but especially in remodeling and repair construction, work also may be done directly for the
owner of the property. Specialty trade contractors usually perform most of their work at the
construction site, although they may have shops where they perform prefabrication and other work.
140 U.S. Energy Information Administration (EIA), Natural Gas, website at
https://www.eia.gov/dnav/ng/hist/n9050us2a.htm.
141 U.S. Bureau of Labor Statistics and Federal Reserve Bank of St. Louis, All Employees: Construction: Specialty
Trade Contractors in Texas [SMU48000002023800001SA], retrieved from FRED, Federal Reserve Bank of St. Louis;
https://fred.stlouisfed.org/series/SMU48000002023800001SA, December 6, 2022.
61
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Establishments primarily engaged in preparing sites for new construction are also included in this
subsector.142
FRED — All Employees: Construction: Specialty Trade Contractors in Texas
2006 2008
Shaded areas indicate U.S. recessions.
2012 2014 2016
Sources: BLS; St. Louis Fed
2020 2022
fred.stiouisfed.org
Figure 5-14. Specialty Trade Contractors in Texas
FRED — All Employees: Construction: Specialty Trade Contractors in Louisiana
77.5
2006 2008
Shaded areas indicate U.S. recessions.
2012 2014
Sources: BLS; St. Louis Fed
2020 2022
fred stiouisfed org
Figure 5-15. Specialty Trade Contractors in Louisiana
142 U.S. Bureau of Labor Statistics, Specialty Trade Contractors: NAICS 238, website at:
https://www.bls.gov/iae/tgs/iag238.htm.
62
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Figure 5-16. Specialty Trade Contractors in Oklahoma
Figure 5-17. Specialty Trade Contractors in Ohio
As indicated by these summaries, employment has rebounded to above pre-pandemic levels in Texas
and Ohio. Louisiana's employment level is still well below 2019 levels, initially slowing through 2021, but
with sharp declines in the number of employees again in 2022. This information doesn't necessarily
provide a sense of available labor capacity going forward; however, it does indicate that some states
have lost installation labor capacity as compared to historic levels, though it could also indicate that the
overall installation labor market could potentially be higher than current levels.
A forward-looking indicator of construction activity is the Construction Backlog Indicator (CBI) from
Associated Builders and Contractors (ABC).143 A chart showing the latest (September 2022) CBI reading is
shown in Figure 5-18 below. According to ABC, the CBI is a forward-looking national economic indicator
that reflects the amount of work that will be performed by commercial and industrial contractors in the
months ahead. We include data from this indicator in this report because this new, national economic
data set is the only reliable leading economic indicator offering this level of specificity focused on the
143 CBI methodology: httpsV/www.abc.org/Portals/l/Documents/CBI/CBIMethodologvl.pdf. September release:
https://www.abc.org/News-Media/News-Releases/entrvid/19644/abcs-construction-backlog-indicator-iumps-in-
september-contractor-confidence-remains-steadv.
63
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U.S. commercial and institutional, industrial, and infrastructure construction industries, which are
among those affected by this final rule.
ABC ABC Construction Backlog Indicator & Construction Confidence Index, 2012-Sep. 2022
iCBI CCI Sales CCI Profit Margins CCI Staffing Levels 80
10
9
o 8
to
CD
o 7
«
c 6
o
2
5 5
o
¦£> ^ <£• <£• &
? / J ^ ^
6Associated BitMers and Contractors, Constructor) Backlog Indicator Construction Confidence Index
70
en
c
H5
60 J
a:
o
50 c
o
*1
o
o
30 o
20
Figure 5-18. Construction Backlog Indicator through September 2022
The CBI measures months of backlog in construction activity. The September 2022 value of 9.0 is an
increase above the value of 8.7 measured in August 2022. It is also 1.4 points higher than the value from
September 2021. Figure 5-18 also provides ABC's Construction Confidence Index, which has three
separate readings representing sales, profit margins, and staffing. Any value above 50 indicates
expectations for growth over the next six months. So, while values are down from a year ago, the
readings all continue to point toward higher levels of construction activity.
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6. Summary of Results
6.1 Estimated Time Needed for Controls to be Installed on All Non-EGU Emissions Units
Assuming that all phases of permitting and control installation proceed without delays and not
accounting for any supply chain constraints noted in Section 6.3 below, when looked at individually, the
estimated non-EGU emissions units could potentially install controls to achieve compliance within 28
months of final rule publication (see Table 4-1).
If there are supply chain disruptions or delays (including vendor or equipment shortages, such that
vendor capacity does not increase from its current level in order to meet demands for additional control
installations), this 28-month time estimate could increase in some cases. As described in more detail in
Section 6.3 and summarized in Table 6-1 below, the total amount of time required including potential
supply chain delays is as follows for the source types affected by potential delays:
• ASNCR application extends to 35 - 57 months (MWC),
• LC application to natural gas transmission system RICE extends to 40 - 72 months,
• Boilers extends to as much as 37 months, and
• Cement extends to as much as 58 months.
See Section 6.3 for additional details.
6.2 Estimated Time Needed for Non-EGU Emissions Units to Install Controls
After factoring in all information reviewed for this report, Table 6-1 below provides a summary of the
number of months estimated to conduct all phases of control installation. Two timelines are provided in
the last two columns of the table.
Table 6-1. Summary of Expected Calendar Time Required for Control Installation for an Individual
Source
Estimated
SCD
Industry
Total
Install
Install
Emissions
Control
Estimated
Timeline
Timeline
Source Group
Technology
Installs
(months)
(months)
Cement and
Kilns
SNCR
16
17-24
35-58
Concrete Product
Manufacturing
Glass and Glass
Melting
LNB
61
9-15
9-15
Product
Furnaces
Manufacturing3
Iron and Steel
Reheat
LNB
19
9-15
9-15
Mills and
Furnaces
Ferroalloy
Manufacturing
Pipeline
RICE 2-Cycle
Layered
394
6-12
40-72
Transportation of
Combustion
Natural Gasb
65
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Industry
Emissions
Source Group
Control
Technology
Total
Estimated
Installs
Estimated
Install
Timeline
(months)
SCD
Install
Timeline
(months)
Pipeline
Transportation of
Natural Gasb
RICE 4-Cycle
Rich Burn
NSCR
30
6-12
6-12
Pipeline
Transportation of
Natural Gasb
RICE
unspecified
NSCRor
Layered
Combustion
323
6-12
40-72
Pipeline
Transportation of
Natural Gasb
RICE 4-Cycle
Lean Burn
reciprocating
SCR
158
10-19
10-19
Affected Non-
EGU Industries0
Boilers
LNB+ FGR
151
9-15
9-15
Affected Non-
EGU Industries0
Boilers
SCR
15
14-25
26-37
Municipal Waste
Management
MWC Boilers
LNtm + SNCR
4
22-28
22-28
Municipal Waste
Management
MWC Boilers
ASNCR
57
17-23
35-57
The general approach for assessing time requirements is summarized be
ow:
Step 1 - Estimate base time required for equipment design, vendor selection, fabrication, and
installation ("estimated installation timeline").
• These estimates were taken from comments received, previous EPA reports supporting
the rule, and related technical reports (e.g., RACT assessments). Typically, these
estimates are based on a range of months provided in a data source or combination of
data sources. These timelines are further detailed in Section 4 (summarized in Table 4-
1).
Step 2 - Estimate the additional amount of time associated with supply chain delays.
• These are addressed on a case-by-case basis in Section 6.3.
We note that these estimates presume that the current (i.e., 2022) state of supply chain delays,
including those associated with current levels of skilled labor and availability of necessary materials and
resources, are assumed to continue through 2026, though there is strong evidence of easing of supply
chain delays discussed in Section 5.
6.3 Potential Impact of Supply Chain Constraints on Control Installation Timing
For key NOx source and control combinations, supply chain issues could increase the estimated install
timeline. Supply chain concerns include: equipment vendor availability (e.g., EPCs that handle overall
engineering/design, fabrication, and installation); equipment fabrication backlogs; skilled labor
constraints; local installation labor constraints; and limitations on raw materials. The potential for these
issues to delay equipment installation may be important considerations to support the need to include
flexibility provisions for affected units to comply with the rule.
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Descriptions of where supply chain delays are expected, as well as their length, are provided below:
• No expected supply chain delays: for control installations in Table 6-1, where the "SCD timeline"
is the same as the "estimated install timeline", the control technology is expected to be readily
available or to have a short lead time for design and fabrication (e.g., compact SCR144 or NSCR
applied to RICE; LNB for furnaces in the glass and glass product manufacturing and reheat
furnaces in iron and steel). Further, skilled labor for control equipment design and installation is
expected to be available to meet the estimated demand for services.
• Supply chain delay potential: additional time will likely be needed due to an identified supply
chain limitation. Situations where supply chain delays are expected are summarized below along
with an estimate of the length of delay:
o Cement and concrete product manufacturing, kilns installing SNCR for compliance:
estimated units (16) may be competing for SNCR EPCs along with MWCs (61). Although
36 EGU SNCR optimization projects are expected, as stated previously, in-house
personnel should be able to accommodate these projects. The pool of identified US
SNCR vendors is 9, but the number of these vendors that actually conduct the design
(including modeling), engineering, fabrication, and installation may be less than this.
Based on discussions with control equipment vendors, 5 SNCR installation projects per
year is a representative annual capacity for each vendor.
o MWC boilers: these 61 sources are estimated to achieve compliance by applying either
LNtm + SNCR or ASNCR. The pool of SNCR EPC contractors will likely be limited to those
with boiler expertise in the MWC sector. For the four installations of LNtm + SNCR, these
all involve a single OEM for the original MWC unit (Covanta using their own proprietary
technology). Given the lack of competition for these facilities and no other supply chain
delays, it is assumed that Covanta can address these installations within the required
installation timeline.
The 57 expected ASCNR and 16 cement kiln SNCR installations may be competing for the
same set of vendors. On-line information suggests that there are 3 to 5 vendors capable
of supplying ASNCR technology. The total number of EPC contractors for SNCR is
somewhat larger, but, if selected, it is possible that those companies would still
subcontract to the more limited pool of experienced ASNCR equipment suppliers and
installers to complete a total of 73 SNCR or ASCNR installations.
Assuming that initial studies and permitting requires up to 12 months, there are two
years available before the compliance deadline of May 2026 for final design,
engineering, fabrication, and installation. Discussions with vendors suggest that full
capacity is on the order of 5 projects at any one time for most suppliers (five per year).
Therefore, for purposes of this exercise, we assume 15 to 25 installations could be
addressed by the assumed vendor pool per year; or 30 to 50 units within 2 years. If
vendor capacity does not expand, this leaves an additional 23 to 43 units that may have
144 Note: compact SCR systems are the same in design as the SCRs applied to RICE in the final rule cost analysis.
67
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difficulty installing controls by May 2026 (which could be some combination of cement
kiln SNCR or MWC ASNCR installations). With the current vendor pool able to address 15
to 25 units per year, approximately an additional 18 to 34 months (that is, 23 units/15
units/year x 12 months/year to 43 units/15 units/year x 12 months/year) may be
needed to address installations at all affected units. This results in a total maximum
supply chain delay timeline of 35 to 58 months (17 to 24 months + 18 to 34 months) for
cement installations of SNCR and 35 to 57 months (17 to 23 months + 18 to 34 months,
again showing the broadest range of values) for ASNCR installation at MWCs.
o Pipeline transportation of natural gas. RICE: Application of layered combustion controls
to some RICE may involve emissions units that are over 60 years old. We note that the
age of RICE that may install controls in response to this final rule is not available in the
emissions inventory. Comments received by EPA indicate that while retrofit kits should
be available for these RICE, installations on older units may require skilled labor familiar
with these units and the specialized control kits to be applied. A key uncertainty is the
number of RICE that will elect to apply these combustion kits versus NSCR or another
compliance option (e.g., engine replacement or electrification). EPA's estimates in Table
6-1 above indicate that 394 RICE are estimated to apply layered combustion and 323
RICE are estimated to apply either layered combustion or NSCR. Based on these
estimates and on the conservative assumption that all of these engines are
approximately 60 years in age, this results in a likely high upper range estimate of 717
units that could require specialized labor to install controls (technicians with the skills to
apply layered combustion control kits to older RICE). Industry comments, which we
were not able to verify, cited an older report suggesting that a skilled labor pool is
available to address at most 75 RICE per year. However, other estimates based on
projections of available skilled labor for such RICE as reflected in Figure 5-13 that are
more recent than the labor pool provided in the industry report show the potential for a
RICE retrofit rate as high as 150 RICE per year. With 905 RICE potentially installing NOx
controls according to the final rule non-EGU cost analysis, a retrofit rate of 150 per year
would yield an absolute upper bound of 905/150 = 6 year (or 72 month) installation
timeframe for this number of potential RICE retrofits. Hence, depending on the number
of older RICE that industry decides to control with layered combustion, potentially the
full amount of time needed to complete installations of layered combustion on all
affected units is 717/150 = 4.8 years (58 months). For the portion of RICE estimated to
be addressed by either layered combustion or NSCR, if half of the RICE are addressed by
layered combustion or NSCR, this results in a total estimate of 506 units. The total
amount of time required to address them by the available skilled labor pool is then
506/150 = 3.4 years (40 months). The estimated supply chain delay timeline if all 905
RICE install controls in response to this final rule is expected to range from 40 to 72
months. These estimates do not account for the potential for replacement of older RICE
with new engines instead of retrofitting or further growth in the labor pool and other
resources.
o Affected industries, boilers: sources that require installation of SCR for compliance
aren't expected to compete for control equipment vendors that serve the EGU sector
68
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for equipment fabrication and installation, since EPA expects primarily optimization of
SCRs at existing EGUs which do not require a vendor plus a relatively small number of
SCR installations by May 2026. Also, EGU SCR EPCs are generally a different group of
vendors than those that serve the non-EGU sector. The number of SCR installations
estimated isn't exceptionally large as indicated in Table 6-1; however, information
gathered from vendor contacts indicates some potential delays for equipment
fabrication and certain imported components. Considering this potential additional 12
months of supply chain delay related to equipment fabrication, the full amount of time
needed for SCR installation at an affected industry boiler could extend to 26 to 37
months (as noted in the SCD timeline in Table 6-1).
69
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Appendix A. North American SCR and SNCR Suppliers
This listing of SCR/SNCR vendors serving the North American market was developed from the on-line
data sources cited below. Based on information presented on their corporate websites, each SCR
supplier was allocated into one of the following market segments as shown in Table A-l:
• EGU and Large Non-EGUs: most of these vendors serve the EGU market; but a small number
also serve large non-EGU sources (e.g., MWCs);
• Small EGUs and Non-EGUs: these vendors serve small EGUs, such as natural gas turbine power
plants and the non-EGU sector;
• Internal Combustion Engines: these vendors supply compact SCR systems, primarily for
implementation on RICE.
Table A-2 provides a listing of SCR catalyst manufacturers or recyclers. Table A-3 provides a listing of
SNCR vendors.
Data Sources:
• AWMA Vendor Listings: https://awmabuyersguide.com/;
• Air Pollution Equipment.com: https://www.airpollutioncontrolequipment.com/more-air-
pollution-control-equipment-manufacturers-listings/;
• Institute of Clean Air Companies: https://www.icac.com/page/Members;
• General internet search.
Table A-l. SCR Vendors
Company
Apparent Market
Segment
Website
1. Babcock Power Inc.
EGU/large Non-EGU
www.babcockpower.com
2. Babcock & Wilcox
EGU/large Non-EGU
https://www.babcock.com/home/products/selective-
catalytic-reduction-scr-systems/
3. BHI-FW
EGU/large Non-EGU
http://www.bhifw.com/eng/technologies/scr.html
4. Braden
EGU/large Non-EGU
https://braden.com/environmental-care-solutions/
5. CECO/Peerless
EGU/large Non-EGU
https://www.cecoenviro.com/products/selective-catalytic-
reduction-scr-peerless-emissions/
6. CEECO Equipment
EGU/large Non-EGU
https://www.ceecoequipment.com/page/engineered-
equipment-solutions
7. General Electric
EGU/large Non-EGU
https://www.ge.com/steam-
power/services/aqcs/upgrades/nox
8. Fuel Tech Inc.
EGU/large Non-EGU
https://www.ftek.com/en-US/products/productssubapc/scr-
systems-industrial
9. Mitsubishi Power
Systems Americas, Inc.
EGU/large Non-EGU
https://power.mhi.com/products/aqcs/lineup/flue-gas-
denitration
10. CTP Sinto America
Small EGU/Non-EGU
https://ctp-airpollutioncontrol.com/solutions/systems
11. Branch
Environmental
Small EGU/Non-EGU
https://www.branchenv.com/selective-catalytic-reduction-
scr/
12. Catalytic Products
International
Small EGU/Non-EGU
https://www.cpilink.com/selective-catalytic-reduction
13. CORMETECH
Small EGU/Non-EGU
https://www.cormetech.com/screngineering-design/
A-l
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Company
Apparent Market
Segment
Website
14. Durr Systems
Small EGU/Non-EGU
https://www.durr.com/en/products/environmental-
technology/exhaust-gas-and-air-pollution-control
15. GEA
Small EGU/Non-EGU
https://www.gea.com/en/products/emission-
control/catalvtic-gas-cleaning/index.jsp
16. Hamon
Small EGU/Non-EGU
https://www.hamon.com/power/
17. Jardar Systems
Small EGU/Non-EGU
https://www.iardarsystems.com/pollution-control-
systems.html
18. McGill AirCLEAN
LLC
Small EGU/Non-EGU
https://www.mcgillairclean.com/proddenox
19. Nationwide Boiler
Small EGU/Non-EGU
https://www.nationwideboiler.com/environmental-
solutions.html
20. SVI Industrial
Small EGU/Non-EGU
https://sviindustrial.com/selective-catalytic-reduction-
systems/
21. Turner EnviroLogic
Small EGU/Non-EGU
https://www.tenviro.com/Systems/Selective-Catalytic-
Reduction-Systems-SCRs
22. Catalytic
Combustion
RICE: compact SCR
https://www.catalyticcombustion.com/products/selective-
catalytic-reduction/
23. DCL International
RICE: compact SCR
https://dcl-inc.com/products/scr-systems/
24. HUG Engineering
RICE: compact SCR
and Small EGU/Non-
EGU
https://hug-engineering.com/technologies/low-
emissions/technology
25. Johnson-Matthey
RICE: compact SCR
https://matthey.com/products-and-markets/other-
markets/stationary-emissions-control/scr-systems
26. Miratech
RICE: compact SCR
https://www.miratechcorp.com/our-products/scr-dpf-
solutions/
27. MSHS
RICE: compact SCR
and Small EGU/Non-
EGU
https://www.mshs.com/emissions-aftermarket-
treatments/selective-catalyst-reduction-scr-systems/;
28. NETTTechnologies
RICE: compact SCR
https://www.nettinc.com/power-generator-scr-systems
Table A-2. SCR Catalyst Manufacturers or Recyclers
Company
Website
1. CDTi
https://cdti.com/engine-emissions-2022/
2. CORMETECH
https://www.cormetech.com/
3. Mitsubishi Power Systems Americas, Inc.
https://power.mhi.com/products/aqcs/lineup/flue-gas-
denitration
4. Umicore
https://fcs.umicore.com/en/stationary-catalysts/
5. Environex
https://environex.com/services/industrial-catalyst/catalyst-
replacement/
A-2
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Table A-3. SNCR Vendors
Company
Website
1. Babcock Power Inc.
www.babcockpower.com
2. Babcock & Wilcox
https://www.babcock.com/home
/products/selective-catalytic-
reduction-scr-systems/
3. CECO Environmental
https://www.cecoenviro.com/pr
oducts/selective-non-catalytic-
reduction-sncr/
4. CORMETECH
https://www.cormetecli.com/snc
rengineering-design/
5. CTP Sinto America
https://ctp-
airpollutioncontrol.com/solution
s/systems
6. Durr Systems
https://www.durr.com/en/produ
cts/environmental-
technology/exhaust-gas-and-air-
pollution-control
7. Fuel Tech, Inc. (mentions also supplying ASNCR)
www.ftek.com;
https://www.ftek.com/en-
US/products/productssubapc/ur
ea-sncr;
8. ISGEC (mentions also supplying ASNCR)
https://www.isgec.com/apce/ba-
apce-DeNox.php
9. Mobotec (mentions also supplying ASNCR)
https://www. environ mental-
expert, com/products/rota mix-
model-sncr-advanced-selective-
non-catalytic-reduction-system-
438786
A-3
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