Rule To Reduce Interstate Transport of Fine Particulate Matter and Ozone (Clean Air Interstate Rule): Supplemental Notice of Reconsideration, 77101-77113 [05-24609]

Agencies

• ENVIRONMENTAL PROTECTION AGENCY

[Federal Register Volume 70, Number 249 (Thursday, December 29, 2005)]
[Proposed Rules]
[Pages 77101-77113]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 05-24609]


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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Parts 51 and 96

[EPA-HQ-OAR 2003-0053; FRL-8016-6]


Rule To Reduce Interstate Transport of Fine Particulate Matter 
and Ozone (Clean Air Interstate Rule): Supplemental Notice of 
Reconsideration

AGENCY: Environmental Protection Agency (EPA).

ACTION: Notice of reconsideration; request for comment; notice of 
opportunity for public hearing.

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SUMMARY: On May 12, 2005, EPA published in the Federal Register the 
final ``Rule to Reduce Interstate Transport of Fine Particulate Matter 
and Ozone'' (Clean Air Interstate Rule or CAIR). The CAIR requires 
certain upwind States to reduce emissions of nitrogen oxides 
(NOX) and/or sulfur dioxide (SO2) that 
significantly contribute to nonattainment of, or interfere with 
maintenance by, downwind States with respect to the fine particle 
(PM2.5) and/or 8-hour ozone national ambient air quality 
standards (NAAQS). Subsequently, EPA received 11 petitions for 
reconsideration of the final rule. Through Federal Register notices 
dated August 24, 2005 and December 2, 2005, EPA previously initiated 
reconsideration processes on five specific issues in the CAIR and 
requested comment on those issues. In this notice, EPA is announcing 
its decision to reconsider one additional specific issue in the CAIR 
and is requesting comment on that issue.
    The specific issue addressed in today's notice relates to the 
potential impact of a recent D.C. Circuit Court decision, New York v. 
EPA, 413 F.3d 3 (D.C. Cir. 2005), on the analysis used in developing 
CAIR to identify highly cost-effective emission reductions. This court 
decision vacated the pollution control project (PCP) exclusion in the 
New Source Review (NSR) regulations (the exclusion allowed certain 
environmentally beneficial PCPs to be excluded from certain NSR 
requirements).
    The EPA is seeking comment only on the aspect of the CAIR 
specifically identified in this notice. We will not respond to comments 
addressing other provisions of the CAIR or any related rulemakings.

DATES: Comments must be received on or before February 16, 2006. If 
requested, a public hearing will be held on January 17, 2006 in 
Washington, DC. For additional information on a public hearing, see the 
SUPPLEMENTARY INFORMATION section of this preamble.

ADDRESSES: Submit your comments, identified by Docket ID No. EPA-HQ-
OAR-2003-0053, by one of the following methods:
     www.regulations.gov: Follow the on-line instructions for 
submitting comments. Attention Docket ID No. EPA-HQ-OAR-2003-0053.
     E-mail: A-and-R-Docket@epa.gov. Attention Docket ID No. 
EPA-HQ-OAR-2003-0053.
     Fax: The fax number of the Air Docket is (202) 566-1741. 
Attention Docket ID No. EPA-HQ-OAR-2003-0053.
     Mail: EPA Docket Center, EPA West (Air Docket), Attention 
Docket ID No. EPA-HQ-OAR-2003-0053, Environmental Protection Agency, 
Mailcode: 6102T, 1200 Pennsylvania Ave., NW., Washington, DC 20460.
     Hand Delivery: EPA Docket Center (Air Docket), Attention 
Docket ID No. EPA-HQ-OAR-2003-0053, Environmental Protection Agency, 
1301 Constitution Avenue, NW., Room B102; Washington, DC. Such 
deliveries are only accepted during the Docket's normal hours of 
operation, and special arrangements should be made for deliveries of 
boxed information.
    Instructions: Direct your comments to Docket ID No. EPA-HQ-OAR-
2003-0053. EPA's policy is that all comments

[[Page 77102]]

received will be included in the public docket without change and may 
be made available online at https://www.regulations.gov, including any 
personal information provided, unless the comment includes information 
claimed to be Confidential Business Information (CBI) or other 
information whose disclosure is restricted by statute. Do not submit 
information that you consider to be CBI or otherwise protected through 
www.regulations.gov or e-mail. The www.regulations.gov Web site is an 
``anonymous access'' system, which means EPA will not know your 
identity or contact information unless you provide it in the body of 
your comment. If you send an e-mail comment directly to EPA without 
going through www.regulations.gov your e-mail address will be 
automatically captured and included as part of the comment that is 
placed in the public docket and made available on the Internet. If you 
submit an electronic comment, EPA recommends that you include your name 
and other contact information in the body of your comment and with any 
disk or CD ROM you submit. If EPA cannot read your comment due to 
technical difficulties and cannot contact you for clarification, EPA 
may not be able to consider your comment. Electronic files should avoid 
the use of special characters, any form of encryption, and be free of 
any defects or viruses. For additional information about EPA's public 
docket visit the EPA Docket Center homepage at https://www.epa.gov/
epahome/dockets.htm. For additional instructions on submitting 
comments, go to the SUPPLEMENTARY INFORMATION section of this document.
    Docket: All documents in the docket are listed in the 
www.regulations.gov index. Although listed in the index, some 
information is not publicly available, e.g., CBI or other information 
whose disclosure is restricted by statute. Certain other material, such 
as copyrighted material, will be publicly available only in hard copy. 
Publicly available docket materials are available either electronically 
in https://www.regulations.gov or in hard copy at the EPA Docket Center 
(Air Docket), EPA/DC, EPA West, Room B102, 1301 Constitution Ave., NW., 
Washington, DC. The Public Reading Room is open from 8:30 a.m. to 4:30 
p.m., Monday through Friday, excluding legal holidays. The telephone 
number for the Public Reading Room is (202) 566-1744.

FOR FURTHER INFORMATION CONTACT: For general questions concerning 
today's action as well as questions concerning the analyses described 
in section III of this notice, please contact Meg Victor, U.S. EPA, 
Office of Atmospheric Programs, Clean Air Markets Division, Mail Code 
6204J, 1200 Pennsylvania Avenue, NW., Washington, DC 20460, telephone 
(202) 343-9193, e-mail address victor.meg@epa.gov. For legal questions, 
please contact Sonja Rodman, U.S. EPA, Office of General Counsel, Mail 
Code 2344A, 1200 Pennsylvania Avenue, NW., Washington, DC 20460, 
telephone 202-564-4079, e-mail address rodman.sonja@epa.gov. For 
information concerning a public hearing, please contact Jo Ann Allman, 
U.S. EPA, Office of Air Quality Planning and Standards, Air Quality 
Strategies and Standards Division, Mail Code C539-02, Research Triangle 
Park, NC 27711, phone number (919) 541-1815, e-mail address 
allman.joann@epa.gov.

SUPPLEMENTARY INFORMATION:

General Information

A. Does This Action Apply to Me?

    The CAIR does not directly regulate emissions sources. Instead, it 
requires States to develop, adopt, and submit State implementation plan 
(SIP) revisions that would achieve the necessary SO2 and 
NOX emissions reductions, and leaves to the States the task 
of determining how to obtain those reductions, including which entities 
to regulate.

B. What Should I Consider as I Prepare My Comments for EPA?

    Note that general instructions for submitting comments are provided 
above under the ADDRESSES section.
    1. Submitting CBI. Do not submit this information to EPA through 
https://www.regulations.gov or e-mail. Clearly mark the part or all of 
the information that you claim to be CBI. For CBI information in a disk 
or CD ROM that you mail to EPA, mark the outside of the disk or CD ROM 
as CBI and then identify electronically within the disk or CD ROM the 
specific information that is claimed as CBI. In addition to one 
complete version of the comment that includes information claimed as 
CBI, a copy of the comment that does not contain the information 
claimed as CBI must be submitted for inclusion in the public docket. 
Information so marked will not be disclosed except in accordance with 
procedures set forth in 40 CFR part 2. Send or deliver information 
identified as CBI only to the following address: Roberto Morales, U.S. 
EPA, Office of Air Quality Planning and Standards, Mail Code C404-02, 
Research Triangle Park, NC 27711, telephone (919) 541-0880, e-mail at 
morales.roberto@epa.gov, Docket ID No. EPA-HQ-OAR-2003-0053.
    2. Tips for Preparing Your Comments. When submitting comments, 
remember to:
     Identify the rulemaking by docket number and other 
identifying information (subject heading, Federal Register date and 
page number).
     Follow directions--The agency may ask you to respond to 
specific questions or organize comments by referencing a Code of 
Federal Regulations (CFR) part or section number.
     Explain why you agree or disagree; suggest alternatives 
and substitute language for your requested changes.
     Describe any assumptions and provide any technical 
information and/or data that you used.
     If you estimate potential costs or burdens, explain how 
you arrived at your estimate in sufficient detail to allow for it to be 
reproduced.
     Provide specific examples to illustrate your concerns, and 
suggest alternatives.
     Explain your views as clearly as possible, avoiding the 
use of profanity or personal threats.
     Make sure to submit your comments by the comment period 
deadline identified.

Public Hearing

    If requested, EPA will hold a public hearing on today's notice. The 
EPA will hold a hearing only if a party notifies EPA by January 10, 
2006, expressing its interest in presenting oral testimony on issues 
addressed in today's notice. Any person may request a hearing by 
calling Jo Ann Allman at (919) 541-1815 before 5 p.m. on January 10, 
2006. Any person who plans to attend the hearing should visit the EPA's 
Web site at https://www.epa.gov/cair or contact Jo Ann Allman at (919) 
541-1815 to learn if a hearing will be held.
    If a public hearing is held on today's notice, it will be held on 
January 17, 2006 at EPA Headquarters, 1310 L Street (closest cross 
street is 13th Street), 1st floor conference rooms 152 and 154, 
Washington, DC. The closest Metro stop is McPherson Square (Orange and 
Blue lines)--take 14th Street/Franklin Square Exit. Because the hearing 
will be held at a U.S. Government facility, everyone planning to attend 
should be prepared to show valid picture identification to the security 
staff in order to gain access to the meeting room.
    If held, the public hearing will begin at 10 a.m. and end at 2 p.m. 
The hearing will be limited to the subject matter of this document. 
Oral testimony will be limited to 5 minutes. The EPA encourages 
commenters to provide

[[Page 77103]]

written versions of their oral testimonies either electronically (on 
computer disk or CD ROM) or in paper copy. The public hearing schedule, 
including the list of speakers, will be posted on EPA's Web site at 
https://www.epa.gov/cair. Verbatim transcripts and written statements 
will be included in the rulemaking docket.
    A public hearing would provide interested parties the opportunity 
to present data, views, or arguments concerning issues addressed in 
today's notice. The EPA may ask clarifying questions during the oral 
presentations, but would not respond to the presentations or comments 
at that time. Written statements and supporting information submitted 
during the comment period will be considered with the same weight as 
any oral comments and supporting information presented at a public 
hearing.
    All written comments must be received by EPA on or before February 
16, 2006. Because of the need to resolve the issues in this document in 
a timely manner, EPA will not grant requests for extensions of the 
public comment period.

Availability of Related Information

    Documents related to the CAIR are available for inspection in 
Docket No. EPA-HQ-OAR-2003-0053 at the address and times given above. 
The EPA has established a Web site for the CAIR at https://www.epa.gov/
cleanairinterstaterule or more simply https://www.epa.gov/cair/.

Outline

I. Background
II. Today's Action
    A. Grant of Reconsideration
    B. Schedule for Reconsideration
III. Impact on CAIR Analyses of DC Circuit Decision in New York v. 
EPA
    A. Background on New York v. EPA and its Relationship to CAIR
    B. Potential Impact of Collateral Pollutant Increases and 
Mitigation Measures
    1. Increases in Sulfuric Acid Emissions From SCR Retrofits
    2. Increases in Sulfuric Acid Emissions From Wet FGD Retrofits 
in Combination With Switching to Higher Sulfur Coal
    3. Summary of Combinations of CAIR SCR and/or FGD Retrofits and 
Coal Switches That May Increase Sulfuric Acid Emissions
    4. Technology Options Available for Mitigating Sulfuric Acid 
Emission Increases
    5. Analysis of SO3/H2SO4 
Mitigation Costs and Timing Impacts for CAIR SCR and/or Wet FGD 
Projects
    6. Increases in Carbon Monoxide and Unburned Carbon (Solid 
Particulate) Emissions From Combustion Controls
    7. Increases in Direct PM2.5 Resulting From Fugitive 
Emissions From Storage or Handling of Lime, Limestone, or FGD Waste 
After Installation of Dry or Wet FGD
    8. Collateral Air Pollutant Emissions From Units Switching From 
High to Low Sulfur Coals
    9. Summary of Section III.B.
    C. Potential Impact of NSR Permitting
IV. Statutory and Executive Order Reviews
    A. Executive Order 12866: Regulatory Planning and Review
    B. Paperwork Reduction Act
    C. Regulatory Flexibility Act
    D. Unfunded Mandates Reform Act
    E. Executive Order 13132: Federalism
    F. Executive Order 13175: Consultation and Coordination With 
Indian Tribal Governments
    G. Executive Order 13045: Protection of Children From 
Environmental Health and Safety Risks
    H. Executive Order 13211: Actions That Significantly Affect 
Energy Supply, Distribution or Use
    I. National Technology Transfer Advancement Act
    J. Executive Order 12898: Federal Actions To Address 
Environmental Justice in Minority Populations and Low-Income 
Populations

I. Background

    On May 12, 2005, the EPA (Agency or we) promulgated the final 
``Rule to Reduce Interstate Transport of Fine Particulate Matter and 
Ozone'' (Clean Air Interstate Rule or CAIR)(70 FR 25162). As explained 
in the CAIR preamble and summarized in our December 2, 2005 
reconsideration notice (70 FR 72268), CAIR requires 28 States and the 
District of Columbia to revise their State implementation plans (SIPs) 
to include control measures to reduce emissions of SO2 and/
or NOX. Sulfur dioxide is a precursor to PM2.5 
formation and NOX is a precursor to PM2.5 and 
ozone formation. By reducing upwind emissions of SO2 and 
NOX, CAIR will assist downwind PM2.5 and 8-hour 
ozone nonattainment areas in achieving the NAAQS. As also described in 
the December 2005 reconsideration notice, the CAIR was promulgated 
through a process that involved significant public participation (70 FR 
72271).
    Following publication of the final CAIR on May 12, 2005, the 
Administrator received eleven petitions requesting reconsideration of 
certain aspects of the final rule. The complete petitions are available 
in the docket for the CAIR.\1\ The petitions were filed pursuant to 
section 307(d)(7)(B) of the CAA. Under this provision, the 
Administrator is to initiate reconsideration proceedings if the 
petitioner can show that an objection is of central relevance to the 
rule and that it was impracticable to raise the objection to the rule 
within the public comment period or that the grounds for the objection 
arose after the public comment period but before the time for judicial 
review had run.
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    \1\ Petitions for reconsideration were filed by: State of North 
Carolina (OAR-2003-0053-2192); FPL Group (OAR-2003-0053-2201); 
Florida Association of Electric Utilities (OAR-2003-0053-2200); 
Entergy Corporation (OAR-2003-0053-2195 and 2198 (attachment 1)); 
Massachusetts Department of Environmental Protection (OAR-2003-0053-
2199); Integrated Waste Services Association (OAR-2003-0053-2193); 
Texas Commission on Environmental Quality (OAR-2003-0053-2212); 
Northern Indiana Public Service Corporation (OAR-2003-0053-2194 and 
2213 (supplemental petition)); City of Amarillo, Texas, El Paso 
Electric Company, Occidental Permian Ltd, and Southwestern Public 
Service Company d/b/a/ Xcel Energy (OAR-2003-0053-2196 and 2197 
(attachment 1) and 2205-2207 (attachments 2-4)); Connecticut 
Business and Industry Ass'n (OAR-2003-0053-2203); and Minnesota 
Power, a division of ALLETE. Inc. (OAR-2003-0053-2212).
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    The EPA has already initiated a reconsideration process on five 
specific aspects of the final CAIR. On August 24, 2005 (70 FR 49708) 
and on December 2, 2005 (70 FR 72268), we published in the Federal 
Register notices announcing these decisions to reconsider specific 
aspects of the CAIR and requesting comment on those issues. Today's 
notice announces EPA's decision to reconsider one additional issue 
raised in a petition for reconsideration and requests comment on that 
additional issue.
    By a letter dated December 22, 2005 we informed a petitioner of our 
intent to grant reconsideration on an issue addressed in their petition 
for reconsideration. We indicated in that letter that we would initiate 
the reconsideration process by publishing this notice.

II. Today's Action

A. Grant of Reconsideration

    In this notice, EPA is announcing its decision to grant 
reconsideration on one issue raised in the petitions for 
reconsideration. This notice initiates that reconsideration process and 
requests comment on the issue to be addressed. Given the intense public 
interest in this rule, EPA has decided to provide this additional 
opportunity for public comment. At this time, however, EPA does not 
believe that any of the information submitted to date demonstrates that 
EPA's final decisions were erroneous or inappropriate. Therefore, we 
are not proposing any modifications to the final CAIR.
    The issue on which EPA is requesting comment relates to the 
potential impact of a recent judicial opinion on the highly cost-
effective analysis prepared by EPA in developing the CAIR. This

[[Page 77104]]

case, New York v. EPA, 413 F.3d 3 (D.C. Cir. 2005) was decided on June 
24, 2005--after the final CAIR was published but before the time for 
judicial review of the rule had run. This issue is described in greater 
detail in Section III of this notice.
    The EPA is requesting comment only on the issue specifically 
described in Section III. We are not taking comment on any other 
provisions in the CAIR or otherwise reopening any other issues decided 
in the CAIR for reconsideration or comment.

B. Schedule for Reconsideration

    For the issue addressed in this notice, EPA expects to take final 
action on reconsideration by March 15, 2006. By that date, EPA will 
finalize the process of reconsideration by issuing a final rule or 
proposing a new approach. EPA also expects, by March 15, 2006, to issue 
decisions on all remaining issues raised in the petitions for 
reconsideration.

III. Impact on CAIR Analyses of DC Circuit Decision in New York v. EPA

A. Background on New York v. EPA and Its Relationship to CAIR

    One industry petitioner claims that a recent opinion of the DC 
Circuit raises questions about the sufficiency of EPA's analysis 
prepared for the CAIR to identify highly cost-effective emission 
reductions. The petitioner argues that EPA should reconsider this 
analysis to take into account the potential impact of the decision in 
New York v. EPA, 413 F.3d 3 (D.C. Cir. 2005). This judicial opinion was 
issued on June 24, 2005--after the final CAIR had been promulgated, but 
within the 60 days provided by CAA section 307(b) for filing of 
petitions for review.\2\ Among other things, the opinion vacated a 
provision of the New Source Review (NSR) regulations, commonly known as 
the pollution control project (PCP) exclusion. All pending petitions 
for rehearing of the case were denied by the Court on December 9, 2005. 
The EPA's request that the Court clarify its holding with regard to any 
retroactive effect of its ruling on the PCP issue was also denied. The 
Court determined that this clarification request was premature because 
no specific retroactive application of the provision was before the 
Court. The time for filing Petitions for Certiorari with the United 
States Supreme Court has not yet run. The analysis that follows looks 
at the potential impact of the New York v. EPA decision.
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    \2\ CAA section 307(d)(7)(B) provides that the Administrator 
shall convene a proceeding for reconsideration if the person raising 
an objection can show that: it was impracticable to raise the 
objection during the period for public comment or the grounds for 
the objection arose after such period but within the time specified 
for judicial review; and the objection is of central relevance to 
the outcome of the rule.
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    The PCP exclusion provided a mechanism for sources to exclude 
certain environmentally beneficial PCPs from the definition of ``major 
modification'' under Prevention of Significant Deterioration (PSD)/NSR 
\3\ even though the PCP resulted in a significant net emissions 
increase in a collateral pollutant (e.g., increase in NOX 
from flaring VOCs). This exclusion could only apply if the owner or 
operator, before beginning construction of the PCP, either provided 
notice to the Administrator (for certain projects listed in the 
regulations) or submitted a permit application to obtain approval to 
use the exclusion. If the exclusion were found not to apply, the source 
would either have to ensure that the PCP did not result in a 
significant net emissions increase in a collateral NSR-regulated 
pollutant (and thus avoid NSR review), or apply for and receive a NSR 
permit for the project. Petitioner asks EPA to reconsider whether EPA's 
highly cost effective analysis ``continues to be valid given the 
court's holding in [New York v. EPA].'' More specifically, Petitioner 
claims that CAIR sources will need to go through NSR permitting and 
that additional time and financial costs will be required for this 
permitting. Petitioner does not specify which projects it believes 
might require NSR permitting or what collateral increases in NSR-
regulated pollutants it expects. Petitioner also claims that additional 
time will be necessary for NSR permitting and that therefore the 
compliance deadlines of January 1, 2009 and 2010 are ``in jeopardy.'' 
Petitioner, however, does not ask EPA to reconsider the 2009 and 2010 
compliance deadlines. As noted above, this notice grants 
reconsideration only on the issue of the impact of the New York v. EPA 
decision on EPA's highly cost effective analysis.
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    \3\ PSD is the part of the NSR program that applies to sources 
located in areas in attainment with the NAAQS. Unless otherwise 
noted, in this notice, when we refer to the NSR program, NSR review, 
NSR permitting or other NSR requirements, we are referring to both 
the NSR and PSD programs and their respective requirements.
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    In developing the CAIR, EPA conducted extensive analyses to 
identify highly cost-effective SO2 and NOX 
emissions reductions based on controlling EGUs. These analyses are 
explained in the preamble to the CAIR (70 FR 25202-25212). The EPA has 
reviewed the petition for reconsideration and analyzed the potential 
impact of New York v. EPA on the CAIR cost-effectiveness determination 
and timing. This analysis indicates that some EGUs that install 
SO2 and/or NOX controls for CAIR may incur 
relatively minor additional costs and minor impacts on timing as a 
result of New York v. EPA, but these potential impacts will neither 
affect the highly cost-effective determination that the Agency made in 
CAIR nor impact the timeframe for CAIR reductions. The EPA's analysis 
further shows that options exist that would allow units to meet the 
CAIR deadlines without changing plans to stagger PCP projects (sources 
will not be forced to install all PCPs at one time) and that the 
related costs would not alter the highly cost effective analysis done 
for the final CAIR. The EPA invites comments on this analysis and the 
potential impact of the New York v. EPA decision on EPA's highly cost-
effective determination. EPA's analysis of this issue is summarized 
below and supplemental information is in the CAIR docket.
    In order to evaluate the petitioner's claim, the Agency examined 
the potential for collateral increases in NSR-regulated air pollutants 
from the types of NOX and SO2 controls on which 
EPA based its CAIR cost-effectiveness determination.\4\ The EPA 
identified which of these technologies could have the potential to 
cause collateral increases in NSR-regulated air pollutants. The EPA 
then analyzed whether sources could mitigate any such collateral 
increases to avoid NSR review and analyzed the cost and timing impacts 
associated with potential mitigation measures. The EPA determined that 
projected collateral increases in NSR-regulated pollutants that might 
be significant enough to trigger an NSR threshold could be mitigated by 
many sources wishing to avoid the NSR permitting process. However, some 
sources may not be able to ensure mitigation of all collateral 
increases. Therefore, the Agency also analyzed the impacts associated 
with NSR permitting for these NOX and SO2 
pollution control projects.
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    \4\ All references to ``collateral increases'' in this document 
refer to potential collateral increases in NSR-regulated air 
pollutants.
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    The EPA considered each of the NOX and SO2 
control measures that were included in the CAIR cost-effectiveness 
determination and found that the following technologies may have the 
potential to cause collateral increases in air pollutants regulated 
under NSR: combustion controls, selective catalytic reduction (SCR), 
flue gas desulphurization (FGD), and fuel

[[Page 77105]]

switches to low sulfur coal. Many affected sources can choose to 
implement measures to mitigate the potential collateral emission 
increases (thereby obviating the need to undertake NSR analysis).
    The Agency determined that some cost increases will result from 
actions that sources may take to mitigate collateral increases that 
result from CAIR control actions; however these impacts do not alter 
the final highly cost effective determination made in the final CAIR. 
In addition, implementing these control actions will not affect the 
feasibility of implementing the CAIR reductions in the required 
timeframe.
    Further, if some sources apply for an NSR permit, the Agency 
believes that the impacts of NSR permitting will not affect the CAIR 
highly cost-effectiveness determination or the CAIR timeline. Note that 
in today's notice the Agency is not making any determination or 
prediction regarding what the specific NSR requirements might be for 
such projects.
    The EPA's analysis for each of these NOX and 
SO2 controls is discussed below and in a Technical Support 
Document (TSD) available in the docket entitled ``Technical Support 
Document: Impact on CAIR Analyses of D.C. Circuit Decision in New York 
v. EPA.''

B. Potential Impact of Collateral Pollutant Increases and Mitigation 
Measures

1. Increases in Sulfuric Acid Emissions From SCR Retrofits \5\
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    \5\ This SCR discussion is focused on the potential for sulfuric 
acid emission increases from SCR retrofits. Note that SCR conditions 
also favor a reaction between SO3 and ammonia that 
produces ammonium bisulfate which condenses to form solid PM, 
however the majority of this PM will be captured in the particulate 
control device installed at the unit. Any such increase in PM 
emissions would likely not be significant enough to trigger NSR 
review, even when considered together with the small increase in PM 
emissions that could occur from storage or handling lime, limestone, 
or FGD waste (see discussion below).
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    Many CAIR units are projected to install selective catalytic 
reduction (SCR) to reduce NOX emissions. The SCR catalyst 
oxidizes a portion of the SO2 present in flue gas to 
SO3. The amount of SO3 added to the flue gas 
stream by SCR will be directly proportional to the fuel sulfur content. 
(Note that SO2 is also oxidized to SO3 in the 
boiler itself.)
    Some SO3 reacts with moisture in the flue gas to form 
sulfuric acid (H2SO4) and exits the stack as 
sulfuric acid vapor. The Agency's analysis for today's notice assumes 
that all sulfuric acid emitted will be counted as emissions of sulfuric 
acid mist--an NSR-regulated pollutant.
    Sulfuric acid mist is also regulated under NSR as PM2.5 
(a criteria pollutant). Because PM2.5 is a criteria 
pollutant, the NSR requirements vary depending on the location of the 
unit experiencing the emission increase, i.e., whether the unit is 
located in a nonattainment area. See further discussion of the Agency's 
analysis regarding permitting for these projects, below.
    Although SCR retrofits can lead to increased sulfuric acid 
emissions, for the following reasons EPA expects that many units 
installing SCR for CAIR will not actually increase their sulfuric acid 
emissions and will therefore not incur any cost increase or timing 
burden associated with collateral increases of sulfuric acid:
    Installing Both SCR and FGD. Many CAIR units that are expected to 
install SCR to reduce NOX emissions also are expected to 
install flue gas desulphurization (FGD) to reduce SO2 
emissions, and FGD is also effective at reducing SO3/
H2SO4 emissions. The two most common types of FGD 
systems (on which the Agency's CAIR cost-effectiveness analysis was 
based) are a lime-based spray dryer system (dry FGD) and a limestone-
based wet FGD system (wet FGD). Considering the effectiveness of FGD at 
mitigating SO3/H2SO4 emissions, the 
Agency expects that a CAIR unit installing SCR and FGD at the same time 
would not increase sulfuric acid emissions significantly enough to 
trigger NSR.
    Note that some units may switch to a higher sulfur coal when they 
install FGD. The combination of installing SCR and dry FGD and 
switching to high sulfur coal may not result in increased sulfuric acid 
because dry FGD is very effective at mitigating SO3/
H2SO4. However, installation of SCR in 
combination with wet FGD and a switch to high sulfur coal could result 
in a significant net increase in sulfuric acid emissions.
    Switching to Lower Sulfur Coal with SCR Retrofit. Some CAIR units 
that burn high sulfur coal may also choose to switch to lower sulfur 
coal when installing SCR. For units switching from high to low sulfur 
coal and installing SCR, there would likely be no net increase in 
sulfuric acid emissions.
    Ceasing to Inject SO3 with SCR Retrofit. Many CAIR units have cold-
side electrostatic precipitators (ESP) in place to control particulate 
matter emissions. These control devices perform better with 
SO3 present in the flue gas. Some units that have previously 
switched from higher-to lower-sulfur coal use injected SO3 
to bring the cold-side ESP performance back up. If such a unit installs 
SCR for CAIR, then the increased SO3 from the SCR would 
lessen or obviate the need for SO3 injection, and without 
the SO3 injection there may be no net increase in sulfuric 
acid emissions.
2. Increases in Sulfuric Acid Emissions From Wet FGD Retrofits in 
Combination With Switching to Higher Sulfur Coal
    Many CAIR units are projected to install FGD to reduce 
SO2 emissions. As discussed above, operation of dry or wet 
FGD reduces SO3/H2SO4 emissions. 
However, some units installing FGD for CAIR may choose to switch to a 
higher sulfur coal at the time they install FGD. Dry FGD reduces 
SO3/H2SO4 sufficiently to most likely 
mitigate any increase from the higher sulfur coal. Considering the 
lower SO3/H2SO4 removal efficiency of 
wet FGD, however, the potential exists for sulfuric acid emissions to 
increase from units that install wet FGD and switch to higher sulfur 
coal.
3. Summary of Combinations of CAIR SCR and/or FGD Retrofits and Coal 
Switches That May Increase Sulfuric Acid Emissions
    The following table summarizes combinations of SCR and/or FGD 
control retrofits and coal switches that may occur as a result of CAIR, 
and identifies which of these combinations could lead to increases in 
sulfuric acid emissions significant enough to trigger the NSR 
threshold.

Table III-1.--Combinations of CAIR SCR and/or FGD and Coal Switches That
                  May Increase Sulfuric Acid Emissions
------------------------------------------------------------------------
  Combinations of SCR and/or FGD and coal     Increase in sulfuric acid
                 switches                            emissions?
------------------------------------------------------------------------
Install SCR...............................  Possible.
Install SCR and switch from high to low     No.
 sulfur coal.
Install SCR with wet FGD (no coal switch).  No.
Install SCR with wet FGD and switch to      Possible.
 higher sulfur coal.
Install wet FGD (no coal switch)..........  No.
Install wet FGD and switch to higher        Possible.
 sulfur coal.
Install SCR and dry FGD...................  No.
Install dry FGD...........................  No.
------------------------------------------------------------------------


[[Page 77106]]

4. Technology Options Available for Mitigating Sulfuric Acid Emission 
Increases
    Several technology options are available for mitigating sulfuric 
acid emission increases from CAIR retrofit projects. These include:
     Injecting alkali materials into the furnace;
     Injecting alkali postfurnace;
     Injecting ammonia;
     Fuel switching (e.g., firing lower sulfur coal);
     Selecting specialized SCR catalyst with a low 
SO3 conversion rate;
     Installing wet ESP; and
     Installing FGD.
    The Agency anticipates that some CAIR sources may choose to install 
emerging multipollutant control technologies designed to reduce not 
only SO2 and NOX but SO3 and other 
pollutants as well. Generally, sources choosing to employ such 
technologies would do so if they found it to be economical. Although 
EPA does not endorse the purchase or sale of any specific products and 
services mentioned, example multipollutant technologies include:
     Powerspan ECO Technology; and
     Mobotec USA Inc. ROTAMIX System.
5. Analysis of SO3/H2SO4 Mitigation 
Costs and Timing Impacts for CAIR SCR and/or Wet FGD Projects
    Cost Modeling for SO3/H2SO4 Controls. The Agency used the 
Integrated Planning Model (IPM) \6\ to provide an upper-end estimate of 
the possible cost impacts for CAIR units that may install 
SO3/H2SO4 controls. The EPA does not 
believe this analysis provides a true estimate of the costs to CAIR 
units of the NY v. EPA decision. Instead, EPA believes this analysis 
significantly overstates the potential costs. However, because this 
analysis shows that even when the costs are significantly overestimated 
they do not impact the analyses done for the final CAIR, EPA determined 
that a more refined analysis was not necessary to address petitioner's 
concerns.
---------------------------------------------------------------------------

    \6\ The IPM is a multiregional, dynamic, deterministic linear 
programming model of the U.S. electric power sector. The Agency uses 
IPM to examine costs and, more broadly, analyze the projected impact 
of environmental polices on the electric power sector in the 48 
contiguous States and the District of Columbia.
---------------------------------------------------------------------------

    The EPA believes this analysis overstates the likely true cost 
impact because, as explained below, it relies on several conservative 
assumptions. For example, we assumed that every unit that is projected 
to install SCR and/or wet FGD will incur increased costs for 
SO3/H2SO4 mitigation.
    Our cost analysis is based on the assumption that each unit that 
retrofits SCR and/or wet FGD will install wet ESPs for SO3/
H2SO4 mitigation.\7\ The Agency believes that the 
choice of SO3/H2SO4 mitigation method 
would depend greatly on the specifics of the affected sources, thus it 
is difficult to predict control choices. For this cost analysis, EPA 
chose to model costs based on wet ESP because we believe the costs of 
this technology are representative of the costs of technologies that 
sources might choose to install.
---------------------------------------------------------------------------

    \7\ Although the Agency based this analysis on installation of 
wet ESP, the Agency is not making any determination or prediction 
regarding what the specific PSD/NSR requirements might be for these 
projects.
---------------------------------------------------------------------------

    The EPA performed an IPM sensitivity analysis in which we added 
costs for wet ESP to every unit that installs SCR and/or wet FGD. We 
based this sensitivity analysis on the IPM model run that includes the 
CAIR, Clean Air Mercury Rule (CAMR) and Clean Air Visibility Rule 
(CAVR) requirements. Note that the IPM modeling for the final CAIR 
highly cost-effectiveness determination does not include the CAMR and 
CAVR requirements. However, the Agency subsequently conducted IPM 
modeling that reflects CAIR, CAMR and CAVR. The IPM analysis discussed 
in today's notice (which examines the possible cost impacts of 
SO3/H2SO4 mitigation) is based on the 
modeling that includes CAIR, CAMR and CAVR because that modeling best 
reflects current requirements.\8\
---------------------------------------------------------------------------

    \8\ The two model runs (the final CAIR modeling or the 
subsequent modeling with CAMR and CAVR) use the same underlying base 
case assumptions in the same modeling platform. In other words, the 
two runs are based on identical assumptions for parameters such as 
(this is not an exhaustive list): EGU inventory, fuel prices, 
impacts of the national title IV SO2 program, 
NOX SIP program, State-specific programs, and NSR 
settlements. Note that projected marginal costs for CAIR 
SO2 and NOX reductions are about $100 per ton 
less in the CAIR/CAMR/CAVR modeling than in the final CAIR modeling, 
due to interactions between the three programs.
---------------------------------------------------------------------------

    As noted above, this modeling--the SO3/
H2SO4 mitigation IPM sensitivity modeling--
overstates the possible cost impacts to CAIR units for several reasons. 
As discussed above, only the following three combinations of CAIR SCR 
and/or wet FGD retrofits might increase sulfuric acid emissions 
significantly to trigger the NSR threshold: units installing SCR alone 
(without switching to lower sulfur coal); units installing SCR with wet 
FGD and switching to higher sulfur coal; and, units installing wet FGD 
alone and switching to higher sulfur coal. The IPM sensitivity analysis 
conservatively assumes SO3/H2SO4 
mitigation costs are incurred by every unit projected to retrofit SCR 
and/or wet FGD. We note, however, that based on EPA's IPM modeling, for 
the first and second CAIR phases, respectively, only 16 percent and 11 
percent of total CAIR-affected generating capacity (i.e., capacity of 
units in CAIR States with capacity greater than 25 MW) are projected to 
retrofit in any of these three combinations that might increase 
sulfuric acid emissions significantly to trigger the NSR threshold.
    Also, it is possible that units that inject SO3 to 
improve cold-side ESP performance would cease injecting SO3 
after installing SCR which could result in the net SO3 
increase being insufficient to trigger NSR (as discussed above), 
however the Agency's IPM sensitivity does not take into account this 
possibility.
    Additionally, the IPM sensitivity model run overstates the cost 
impacts to CAIR units because that modeling added SO3/
sulfuric acid mitigation costs for all units retrofitting SCR and/or 
wet FGD, including retrofits that are projected to occur prior to 
commencement of CAIR retrofits (the Agency assumes that retrofits 
occurring prior to 2007 do not result from CAIR, but rather from 
existing programs such as the title IV SO2 program and the 
NOX SIP Call, however the IPM modeling does not account for 
this distinction). Further, our analysis overstates the cost impacts to 
CAIR units because the modeling includes retrofits that occur in the 
base case (without CAIR) and also includes the CAMR and CAVR 
requirements.
    Further, in the IPM sensitivity analysis we assumed units would 
incur costs for year-round operation of wet ESP in all CAIR States, 
including the States that are only required to make ozone season 
NOX reductions for CAIR. Finally, the IPM sensitivity run 
overstates the cost impacts because we added costs for wet ESP to each 
affected unit although SO3/H2SO4 
mitigation options are available that are less expensive than wet ESP.
    Nonetheless, the Agency's cost analysis assumed that every unit 
that is predicted to install SCR and/or wet FGD in the CAIR/CAMR/CAVR 
modeling will incur additional costs for year-round operation of a wet 
ESP, in order to provide an upper-end estimate of the possible cost 
impacts of SO3/H2SO4 mitigation.
    Table III-2 shows the results of this analysis. It compares the 
SO2 and NOX

[[Page 77107]]

marginal costs in the SO3/H2SO4 
mitigation sensitivity analysis to the marginal costs in the final CAIR 
modeling (Table III-2 also shows marginal costs from the modeling that 
included CAIR, CAMR and CAVR).\9\ In the sensitivity analysis, the 
costs of SO3/H2SO4 mitigation are 
reflected in the marginal costs of SO2 and NOX 
control.
---------------------------------------------------------------------------

    \9\ As in the CAIR NFR (70 FR 25198), the Agency reports cost 
effectiveness results for both of the CAIR phases although the Phase 
I CAIR control levels were determined based on feasibility rather 
than cost effectiveness.

            Table III-2.--SO2 and NOX Estimated Marginal Cost
                           [1999$ per ton] \1\
------------------------------------------------------------------------
                                   SO2 Annual            NOX Annual
                             -------------------------------------------
                                 2010       2015       2009       2015
------------------------------------------------------------------------
CAIR modeling used in final        $700     $1,000     $1,300     $1,600
 CAIR cost-effectiveness
 analysis...................
CAIR/CAMR/CAVR modeling.....        600        900      1,200      1,500
Sensitivity analysis with           700        900      1,600     2,000
 SO3/H2SO4 mitigation (based
 on CAIR/CAMR/CAVR modeling)
------------------------------------------------------------------------
\1\ EPA IPM modeling is available in the docket. Projected costs are
  rounded to the nearest hundred dollars.

    As shown in Table III-2, projected SO2 marginal costs in 
the SO3/H2SO4 mitigation sensitivity 
modeling are lower than the SO2 marginal costs in the final 
CAIR modeling for 2015 and are about the same as the costs in the final 
CAIR for 2010. This does not imply that the added costs of 
SO3H2SO4 mitigation are so small as to 
have no effect on the marginal costs of SO2 reduction. 
Rather, the added costs of SO3/H2SO4 
mitigation increase the SO2 marginal cost from the level in 
the CAIR/CAMR/CAVR run a small amount. As explained above, marginal 
cost levels in CAIR/CAMR/CAVR modeling are lower than costs in the 
modeling in the CAIR final rulemaking. In the SO3/
H2SO4 mitigation sensitivity analysis, the 2010 
cost is increased to about the level in the final CAIR modeling, and 
the 2015 cost increase is small enough that it is not apparent when the 
costs are rounded to the nearest hundred dollars. Including the added 
costs of SO3/H2SO4 mitigation, the 
projected marginal costs of SO2 reduction under CAIR remain 
at the lower end of the reference range of marginal costs cited in the 
Agency's CAIR cost-effectiveness determination. The range of marginal 
costs cited in CAIR is $600 to $2,200 per ton of SO2 removed 
(70 FR 25201-25204).
    As shown in Table III-2, projected NOX marginal costs in 
the SO3/H2SO4 mitigation sensitivity 
are higher than the costs in the final CAIR modeling. However, 
including the added costs of SO3/H2SO4 
mitigation, the projected NOX marginal costs remain at the 
lower end of the reference range of marginal costs cited in the 
Agency's cost-effectiveness determination. The range of marginal costs 
cited in CAIR is $2,000 to $19,600 per ton of annual NOX 
removed (70 FR 25208-25210).
    For the reasons discussed above, the Agency's analysis likely 
overstates the cost impacts of SO3/
H2SO4 mitigation. Nonetheless, even with these 
projected cost impacts, the marginal costs remain at the low end of the 
range of costs cited in the final CAIR highly cost-effectiveness 
determination (70 FR 25201-25204, 25208-25210). Thus, that 
determination is not affected by the possible costs that may be 
incurred by units installing SO3/H2SO4 
mitigation technologies. The Agency believes that average costs of 
SO2 and NOX control also would not increase 
significantly enough to impact the CAIR cost-effectiveness 
determination, because the projected marginal costs do not increase 
enough to impact the CAIR analysis.
    The Agency discusses below its evaluation of the feasibility of 
installing SO3/H2SO4 mitigation 
measures, and the impacts of NSR analysis.
    Feasibility and Timing Analysis. In its CAIR analysis, the Agency 
evaluated the feasibility of installing projected SO2 and 
NOX control retrofits in the CAIR timeframe. In particular, 
EPA examined the availability of boilermaker labor to install retrofits 
during the period when the CAIR retrofits will occur and determined 
that sufficient labor will be available (70 FR 25215-25225). The 
Agency's CAIR analysis was discussed in detail in a TSD entitled 
``Boilermaker Labor and Installation Timing Analysis,'' OAR-2003-0053-
2092 (``final CAIR boilermaker TSD'').
    The Agency has evaluated the potential impacts on the CAIR timeline 
from installation of SO3/H2SO4 
mitigation technologies. Specifically, we examined the impact of 
installing wet ESP on the availability of boilermaker labor during the 
time when control retrofits will be installed for the two CAIR phases. 
The EPA's analysis assumed that units that might experience sulfuric 
acid emission increases greater than the NSR threshold while 
incorporating NOX and/or SO2 controls for CAIR 
would choose to install wet ESP, which is a conservative assumption 
because SO3/H2SO4 mitigation measures 
are available that would require less boilermaker labor than wet ESP. 
For this boilermaker labor analysis, the Agency used the identical 
assumptions regarding boilermaker availability factors (i.e., 
boilermaker sources, population, average annual work hours, activity 
periods, and duty rates) that we used in the boilermaker analysis for 
the final CAIR. These factors are defined in the final CAIR boilermaker 
TSD.
    For today's notice, the Agency based its boilermaker analysis on 
the generating capacity that is projected to install NOX and 
SO2 controls that may increase sulfuric acid emissions (the 
three combinations of SCR and/or wet FGD retrofits and coal switches 
identified in Table III-1). The EPA examined the capacity of retrofits 
that are projected to occur during the time period when CAIR retrofits 
would occur for the two CAIR phases (i.e., during the years 2007 
through 2015 inclusive). This analysis includes retrofits projected to 
occur as result of the CAIR, CAMR and CAVR policies as well as 
retrofits for base case policies (i.e., retrofits for existing 
regulatory requirements such as the title IV SO2 program and 
the NOX SIP Call) because some base case retrofits will 
occur during the time period 2007 through 2015.
    In its analysis for the final CAIR, the Agency determined that 
adequate boilermaker labor would be available to complete the CAIR 
NOX and SO2 control retrofits in the CAIR 
timeline, with sufficient contingency factors available to offset 
possible additional labor needs due to unforeseen events. In the final 
CAIR, EPA considered a number of scenarios that included different 
assumptions for boilermaker duty rates (i.e., the amount of time 
required for a boilermaker to install control equipment), electricity 
demand and gas prices. In the most conservative scenario analyzed, EPA 
determined that there would be a 14 percent boilermaker labor 
contingency (i.e., 14 percent more labor

[[Page 77108]]

would be available than the amount required to install the controls). 
The boilermaker duty rates used for this case were provided by a 
commenter on the CAIR, were well above the levels determined to be 
appropriate in a detailed study conducted by EPA, and, based on EPA's 
investigations, reflected the worst-case assumptions for the 
boilermaker labor requirements associated with building air pollution 
controls. If the boilermaker requirements are estimated using EPA's 
boilermaker duty rates, the available contingency would be higher.
    The revised boilermaker labor analysis that the Agency conducted 
for today's notice, which takes into account boilermaker labor required 
to install wet ESP, indicates that adequate boilermaker labor will be 
available even considering the additional boilermakers that may be 
needed to install the wet ESP. Considering the same assumptions that 
yielded a 14 percent contingency in the final CAIR along with 
additional boilermakers needed to install wet ESPs, EPA determined that 
there would be a 4 percent contingency. Again, if the boilermaker 
requirements are estimated using EPA's boilermaker duty rates, the 
available contingency would be higher.
    This analysis is conservative in that it assumes that in all cases 
where companies install equipment to mitigate SO3/
H2SO4 increases, they install wet ESPs, which use 
more boilermakers than other options such as sorbent injection. The 
remaining contingency factors are still adequate (although reduced). 
Thus, the NOX and SO2 control retrofits projected 
to be installed for CAIR can be completed in the available time, even 
considering the potential additional labor needs for SO3/
H2SO4 mitigation. Note that any SO3/
H2SO4 controls for CAIR projects can be retrofit 
concurrently with the SO2 and NOX retrofits, and 
no additional time would be needed. See further discussion of timing in 
the permitting section, below.
    Details of EPA's revised boilermaker labor analysis are in a TSD in 
the docket entitled ``Impact on CAIR Analyses of D.C. Circuit Decision 
in New York v. EPA.''
    The Agency believes that the impacts of mitigating the potential 
emission increases, or undertaking NSR review for these units, are not 
substantial enough to alter the CAIR highly cost-effective 
determination or the feasibility and timing analysis. Implications of 
NSR analysis for such units are discussed further below.
6. Increases in Carbon Monoxide and Unburned Carbon (Solid Particulate) 
Emissions From Combustion Controls
    Combustion controls that may be installed for CAIR to reduce 
NOX emissions include low NOX burners (LNB) and 
overfire air (OFA). Both LNB and OFA reduce NOX generation 
rates by changing the combustion process. Either one or both 
technologies may be installed on a generating unit to control 
NOX emissions. Depending on the boiler design, these changes 
may result in an increase in emissions of carbon monoxide (CO) and 
unburned carbon (solid particulate), although the potential for 
increases significant enough to trigger the NSR threshold exists only 
with the use of OFA (because LNB does not affect the combustion process 
extensively).
    These emissions increases can be minimized by using more modern 
control designs and techniques.10 11 12 These increases can 
also be minimized by using less-aggressive OFA flow rates.\13\ The 
NOX removal efficiencies for combustion controls assumed in 
EPA's CAIR analysis are not aggressive.\14\ The Agency believes that 
units projected to install combustion controls can opt for moderate 
levels of OFA flow rates and still achieve the NOX reduction 
levels projected in our CAIR analysis, without causing significant 
increases in CO and unburned carbon emissions. Therefore, given the 
conservative removal efficiency assumptions in EPA's original analysis, 
there would be no additional significant costs associated with 
mitigating CO emissions to avoid NSR when combustion controls are 
added.
---------------------------------------------------------------------------

    \10\ T. Steitz, et al., ``Wall Fired Low NOX Burner 
Evolution for Global NOX Compliance,'' Foster Wheeler Web 
site, https://www.fwc.com/publications/tech_papers/index.cfm# 
14905467952D7FCAFC 2A5B206EAE10F0, Web site accessed on September 
30, 2005.
    \11\ K. McCarthy, et al., ``Improved Low NOX Firing 
Systems for Pulverized Coal Combustion,'' Foster Wheeler Web site, 
https://www.fwc.com/publications/tech_papers/index.cfm# 
14905467952D7FCAFC 2A5B206EAE10F0, Web site accessed on September 
30, 2005.
    \12\ ``Reducing Emissions of Nitrogen Oxides Via Low-
NOX Burner Technologies,'' Clean Coal Technology, The 
Department of Energy, Topical Report No. 5, September 1996.
    \13\ A. Kokkinos, et al., ``B&W's Experience Reducing 
NOX Emissions in Tangentially-Fired Boilers--2001 
Update,'' Power-Gen International 2001, December 11-13, 2001, Las 
Vegas, Nevada.
    \14\ The NOX removal efficiency for each type of 
combustion control used in EPA's analysis for CAIR was estimated as 
an average of the reported efficiencies for a large number of units 
equipped with these controls. In a unit equipped with both LNB and 
OFA, LNB provides a greater part of the overall NOX 
removal.
---------------------------------------------------------------------------

    Certain affected CAIR sources are projected to install both 
combustion controls and SCR. These sources have the option to use 
combustion control designs ensuring minimal CO and unburned carbon 
impacts, with SCR compensating for the possible reduced performance of 
combustion controls. Considering the potential of SCR technology to 
provide 90 percent NOX reduction with a minimum 
NOX rate of 0.06 lb/MMBtu, most of these sources would be 
able to use this strategy and avoid use of aggressive combustion 
control designs.
    The affected CAIR sources also have the option to use an advanced 
OFA system with the potential to achieve high NOX reduction 
levels, with no increases in CO and unburned carbon levels. This 
technology utilizes rotating opposed fire air (ROFA) and has been 
installed or demonstrated at several plants worldwide.\15\
---------------------------------------------------------------------------

    \15\ MOBOTECUSA Web site, https://www.mobotecusa.com/.
---------------------------------------------------------------------------

    The Agency believes that there will be no increase in cost to CAIR 
units for using good combustion practices to mitigate CO and unburned 
carbon increases, because industry generally uses such practices 
already. Implementation of these practices would not affect the 
Agency's CAIR highly cost-effectiveness determination or the 
feasibility and timing analysis.
    In addition, the implications of NSR analysis for such units are 
relatively minor, as discussed further below.
    The Agency believes that the impacts of either mitigating the 
potential emission increases, or undertaking NSR review for these 
units, are not substantial enough to affect the CAIR highly cost-
effective determination or the feasibility and timing analysis. 
Implications of NSR analysis for such units are discussed further 
below.
7. Increases in Direct PM2.5 Resulting From Fugitive Emissions From 
Storage or Handling of Lime, Limestone, or FGD Waste After Installation 
of Dry or Wet FGD
    As discussed above, dry and wet FGD are effective SO3/
H2SO4 mitigation options. A separate 
consideration, however, is the potential for increased emissions of 
direct PM (including PM2.5) resulting from the storage and handling of 
lime or limestone for the FGD and from hauling FGD waste.
    The EPA believes that operation of FGD will not result in 
significant increases of emissions of direct PM (including PM2.5). 
Fugitive PM emissions resulting from the storage and handling of lime 
or limestone and from waste hauling associated with FGD operation are 
minimal since most lime

[[Page 77109]]

and limestone will be stored in covered structures with particulate 
controls, lime and limestone will be transported in covered vehicles, 
and particulate emissions mitigation techniques, including spraying 
near storage areas, hauling roads, and waste hauling trucks, will be 
employed. Fugitive emissions could result from dust recirculation due 
to truck hauling, but these emissions are also not significant enough 
to trigger NSR.
    The Agency believes that the impacts of either mitigating these 
small potential emission increases, or undertaking NSR review for these 
units, are not substantial enough to affect the CAIR highly cost-
effective determination or the feasibility and timing analysis.
8. Collateral Air Pollutant Emissions From Units Switching From High to 
Low Sulfur Coals
    A switch from high-to low-sulfur coals is an option projected to be 
used by certain CAIR sources for SO2 control. In some cases, 
modifications to the existing equipment may become necessary to 
maintain compatibility with the boiler and associated systems. One of 
the more common modifications required is the need to restore the 
existing ESP performance, which may be degraded due to the high-
resistivity ash generated from firing of low-sulfur coals (if ESP 
performance is not restored, emissions of PM might increase). In 
general, use of a flue gas conditioning system fully restores the ESP 
performance to levels obtained from firing of high-sulfur coals.
    The impact of coal switching on the existing plant equipment would 
vary with the amount of switch. For example, if only a portion of the 
existing high-sulfur coal is replaced with the new low-sulfur coal, the 
impact may be minimal. Also, use of certain types of low-sulfur coals 
may even have a beneficial impact on some of the NSR-regulated 
pollutants. For example, use of western sub-bituminous coals may result 
in a reduction in the CO and unburned carbon levels, because of the 
high volatile contents of such coals.
    In the CAIR analysis, EPA assumed that the sources opting to switch 
to low-sulfur coal would either select compatible coals or provide 
modifications where required to avoid any adverse impacts on their 
boilers, including minimization of any increases in air emissions. The 
EPA included costs for such modifications in its estimates for the CAIR 
implementation, which were based on the coal switch experience for the 
power industry. Therefore, no further analysis is necessary.
9. Summary of Section III.B.
    EPA's IPM modeling predicts that some CAIR units will add controls 
with the potential to increase collateral emissions of NSR-regulated 
pollutants. However, the Agency has determined that for each of the 
NOX and SO2 controls on which EPA based its CAIR 
highly cost-effectiveness determination, there are technology options 
available to mitigate potential collateral increases of NSR regulated 
pollutants such that many sources, looking to comply with the CAIR 
requirements, would not trigger NSR review for potential collateral 
increases (however, some sources may not be able to ensure mitigation 
of all collateral increases). Further, although some additional cost 
may be associated with mitigation measures, EPA's analysis showed that 
these costs do not change the conclusions of EPA's highly cost-
effectiveness determination. In addition, implementing these mitigation 
measures will not affect the feasibility of implementing the CAIR 
reductions in the required timeframe. Options exist that would allow 
units to meet the CAIR deadlines without changing plans to stagger PCP 
projects. For example, a unit planning to install SCR first and FGD 
l