Latest Version of the GHG Tailoring Rule (4/30)

Pam Long to: King, Heidi R. 04/30/2010 03:45 PM

Cc:

Joseph Goffman, Janet McCabe, Steve Page, Anna Wood, Juan 

Santiago, Joseph Mangino, Michael Ling, Howard Hoffman, Elliott 

Zenick, Paul Balserak

Bcc: Joseph-J Dougherty, Mary Henigin, Alan Rush

Per Michael Lings' request attached is the latest EPA preamble and rule for the GHG Tailoring Rule. I am 

sending a clean version along with a redline/strikeout version that compares it to the version that is 

currently in ROCIS. 

Thank you, Pam S. Long

Environmental Protection Specialist

Regular Mail:

USEPA/OAQPS/NSRG (C504-03)

Room # C505K

RTP, NC 27711

919-541-0641 (Phone)

919-541-5509 (Fax)
1

 6560-50-P 

ENVIRONMENTAL PROTECTION AGENCY 

40 CFR Parts 51, 52, 70, and 71 

[EPA-HQ-OAR-2009-0517; FRL - _________] 

RIN 2060-AP86 

Prevention of Significant Deterioration and Title V Greenhouse 

Gas Tailoring Rule 

AGENCY: Environmental Protection Agency (EPA). 

ACTION: Final Rule. 

SUMMARY: EPA is tailoring the applicability criteria that 

determine which stationary sources and modification projects 

become subject to permitting requirements for greenhouse gas 

(GHG) emissions under the Prevention of Significant 

Deterioration (PSD) and title V programs of the Clean Air Act 

(CAA or Act). This rulemaking is necessary because without it 

PSD and title V requirements would apply, as of January 2, 2011, 

at the 100 or 250 tons per year (tpy) levels provided under the 

CAA, greatly increasing the number of required permits, 

overwhelming the resources of permitting authorities, and 

severely impairing the functioning of the programs. EPA is 

relieving these resource burdens by phasing in the applicability 

of these programs to GHG sources, starting with the largest GHG 

emitters. This rule establishes two initial steps of the phasein. The rule also commits the agency to take certain actions on 
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future steps addressing smaller sources, but excludes certain 

smaller sources from PSD and title V permitting for GHG 

emissions until at least April 30, 2016. 

DATES: This action is effective on [INSERT 60 DAY FROM DATE OF 

PUBLICATION]. 

ADDRESSES: EPA has established a docket for this rulemaking 

under Docket ID No. EPA-HQ-OAR-2009-0517. 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., Confidential Business Information or other information 

whose disclosure is restricted by statute. Certain other 

material, such as copyrighted material, is not placed on the 

Internet and will be publicly available only in hard copy. 

Publicly available docket materials are available either 

electronically in www.regulations.gov or in hard copy at the EPA 

Docket Center EPA/DC, EPA West, Room 3334, 1301 Constitution 

Avenue, Northwest, Washington, D.C. 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, and the telephone number for the 

EPA Docket Center is (202) 566-1742. 

FOR FURTHER INFORMATION CONTACT: Mr. Joseph Mangino, Air 

Quality Policy Division, Office of Air Quality Planning and 
3

Standards (C504-03), Environmental Protection Agency, Research 

Triangle Park, NC 27711; telephone number: (919) 541-9778; fax 

number: (919) 541-5509; e-mail address: mangino.joseph@epa.gov. 

SUPPLEMENTARY INFORMATION: 

I. General Information 

A. Does this action apply to me? 

Entities affected by this action include sources in all 

sectors of the economy, including commercial and residential 

sources. Entities potentially affected by this action also 

include states, local permitting authorities, and tribal 

authorities. The majority of categories and entities 

potentially affected by this action are expected to be in the 

following groups: 

Industry Group NAICSa

Agriculture, fishing, 

and hunting............................ 11 

Mining.............................................

 21 

Utilities (electric, 

natural gas, other 

systems)..........................................

.............. 2211, 2212, 2213 

Manufacturing (food, 

beverages, tobacco, 

textiles, 

leather).................................. 311, 312, 313, 314, 315, 316 

Wood product, paper 

manufacturing...........................

.............. 321, 322 
4

Petroleum and coal 

products 

manufacturing......................... 32411, 32412, 32419 

Chemical 

manufacturing........................... 3251, 3252, 3253,3254, 3255, 

3256,3259 

Rubber product 

manufacturing......................... 3261, 3262 

Miscellaneous chemical 

products..........................................

.............. 32552, 32592, 32591, 325182, 

32551 

Nonmetallic mineral 

product 

manufacturing......................... 3271, 3272, 3273, 3274, 3279 

Primary and fabricated 

metal manufacturing....... 3311, 3312, 3313, 3314, 3315, 

3321, 3322, 3323, 3324, 3325, 

3326, 3327, 3328, 3329 

Machinery 

manufacturing......................... 3331, 3332, 3333, 3334, 3335, 

3336, 3339 

Computer and 

electronic products 

manufacturing......................... 3341, 3342, 3343, 3344, 3345, 

4446 

Electrical equipment, 

appliance, and 

component 

manufacturing......................... 3351, 3352, 3353, 3359 

Transportation 

equipment 

manufacturing......................... 3361, 3362, 3363, 3364, 3365, 

3366, 3366, 3369 

Furniture and related 

product 

manufacturing......................... 3371, 3372, 3379 
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Miscellaneous 

manufacturing......................... 3391, 3399 

Waste management and 

remediation.............................. . 5622, 5629 

Hospitals/Nursing and 

residential care 

facilities.................................. 6221, 6231, 6232,6233, 6239 

Personal and laundry 

services........................................ 8122, 8123 

Residential/private 

households.................................. 8141 

Non-Residential 

(Commercial)............................ Not available. Codes only exist 

for private households, 

construction, and leasing/sales 

industries. a

 North American Industry Classification System. 

B. How is this preamble organized? 

 The information presented in this preamble is organized as 

follows: 

Outline 

I. General Information 

A. Does this action apply to me? 

B. How is this preamble organized? 

C. Preamble Acronyms and Abbreviations 

II. Overview of the Final Rule 

III. Background 

A. What are greenhouse gases and their sources? 

B. Endangerment Finding and the Light-Duty Vehicle Rule 

1. Endangerment Finding 

2. Light-Duty Vehicle Rule 

C. What are the general requirements of the PSD program? 

1. Overview of the PSD Program 

2. General Requirements for PSD 

D. What are the general requirements of the title V 

operating permits program? 
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1. Overview of Title V 

2. Title V Permit Requirements 

E. The Interpretive Memorandum 

IV. Summary of Final Actions 

A. How do you define the GHG pollutant for PSD and title V 

purposes? 

1. GHG Pollutant Defined as the Sum-of-Six Well-Mixed GHGs 

2. What GWP values should be used for calculating CO2e? 

B. When will PSD and title V applicability begin for GHGs 

and emission sources? 

1. What are the Step 1 thresholds, timing, and calculation 

methodology? 

2. What are the Step 2 thresholds, timing, and calculation 

methodology? 

3. What about Step 3? 

4. What about the proposed 6 year exclusion for smaller 

sources? 

5. When and how will EPA take further action on smaller 

sources? 

C. How do state, local, and tribal area programs adopt the 

final GHG applicability thresholds? 

D. How do you treat GHGs for title V permit fees? 

E. Other Actions and Issues 

1. Timing for Permit Streamlining Techniques 

2. Guidance for Best Available Control Technology 

Determinations 

3. Requests for Higher Category-Specific Thresholds and 

Exemptions from Applicability 

4. Transitional Issues including Requests for 

Grandfathering 

V. What is the legal and policy rationale for the final 

actions? 

A. Rationale for Our Approach to Calculating GHG Emissions 

for PSD and Title V Applicability Purposes 

1. Grouping of GHGs into a Single Pollutant 

2. Identifying Which GHGs are Included in the Group 

3. Determining What GWP Values are to be Used 

4. Use of Short Tons vs. Metric Tons 

B. Rationale for Thresholds and Timing for PSD and Title V 

Applicability to GHG Emissions Sources 

 1. Overview 

2. Data Concerning Costs to Sources and Administrative 

Burdens to Permitting Authorities 

3. Legal Doctrines: “Absurd Results,” “Administrative 

Necessity,” and “One-One-Step-at-a-Time” 

 4. The PSD and Title V programs 
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5. Application of the “Absurd results” Doctrine for the 

PSD Program 

6. Application of the “Absurd Results” Doctrine for the 

Title V Program 

 7. Additional Rulemaking for the PSD and Title V Programs 

8. Rationale for the Phase-in Schedule for Applying PSD 

and Title V to GHG Sources 

9. “Administrative Necessity” Basis for PSD and Title V 

Requirements in Tailoring Rule 

 10. “One-One-Step-at-a-Time” Basis for Tailoring Rule 

C. Mechanisms for Implementing and Adopting the Tailoring 

Approach 

1. PSD Approach: Background and Proposal 

2. Rationale for Our Final Approach to Implementing PSD 

3. Other Mechanisms 

4. Codification of Interpretive Memo 

5. Delaying Limited Approvals and Request for Submission 

of Information from States Implementing a SIP-Approved PSD 

Program 

6. Title V Programs 

D. Rationale for Treatment of GHGs for Title V Permit Fees 

E. Other Actions and Issues 

1. Permit Streamlining Techniques 

2. Guidance for Best Available Control Technology 

Determinations 

3. Requests for Higher Category-Specific Thresholds or 

Exemptions from Applicability 

4. Transitional Issues Including Requests for 

Grandfathering 

VI. What are the economic impacts of the final rule? 

A. What entities are affected by this final rule? 

B. What are the estimated annual benefits to sources due 

to regulatory relief from the statutory requirements? 

1. What are annual estimated benefits or avoided burden 

costs for title V permits? 

2. What are annual benefits or avoided costs associated 

with NSR permitting regulatory relief? 

 C. What are the economic impacts of this rulemaking? 

 D. What are the costs of the final rule for society? 

VII. Comments on Statutory and Executive Orders Reviews 

A. Comments on Executive Order 12866 - Regulatory Planning 

and Review 

B. Comments on Paperwork Reduction Act 

C. Comments on Regulatory Flexibility Act 

D. Comments on Unfunded Mandates Reform Act 

E. Comments on Executive Order 13132 – Federalism 
8

F. Comments on Executive Order 13175 - Consultation and 

Coordination with Indian Tribal Governments 

G. Comments on Executive Order 13211 - Actions That 

Significantly Affect Energy Supply, Distribution, or Use 

VIII. Statutory and Executive Orders 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 and Advancement Act 

J. Executive Order 12898 – Federal Actions to Address 

Environmental Justice in Minority Populations and LowIncome Populations 

K. Congressional Review Act 

L. Judicial Review 

XI. Statutory Language 

C. Preamble Acronyms and Abbreviations

 The following are abbreviations of terms used in the 

preamble. 

APA Administrative Procedure Act 

AQRVs Air Quality Related Values 

BACT Best Available Control Technology 

CAA or Act Clean Air Act 

CAAAC Clean Air Act Advisory Committee 

CAFÉ Corporate Average Fuel Economy 

CH4 Methane 

CO Carbon Monoxide 

CO2 Carbon Dioxide 

CO2e Carbon Dioxide Equivalent 

EO Executive Order 

EPA Environmental Protection Agency 

FTEs Full Time Employees 

GHG Greenhouse Gases 

GWP Global Warming Potential 

HAP Hazardous Air Pollutant 
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HFCs Hydrofluorocarbons 

ICR Information Collection Request 

IPCC Intergovernmental Panel on Climate Change 

IQA Information Quality Act 

LDVR Light Duty Vehicle Rule 

N2O Nitrous Oxide 

NAAQS National Ambient Air Quality Standard 

NHTSA National Highway Traffic Safety 

Administration 

NOx Nitrogen Oxide 

NMOC Non-Methane Organic Emissions 

NSPS New Source Performance Standard 

NSR New Source Review 

NTAA National Tribal Air Association 

OMB Office of Management and Budget 

PFCs Perfluorocarbons 

PM Paticulate Matter 

PSD Prevention of Significant Deterioration 

PTE Potential to Emit 

RIA Regulatory Impact Analysis 

RTC Response to Comment 

SBA Small Business Administration 

SBAR Small Business Advocacy Review 

SF6 Sulfur Hexafluoride

SIP State Implementation Plan 

SNPR Supplemental Notice of Proposed Rulemaking 

SO2 Sulfur Dioxide 

TSD Technical Support Document 

TPY Tons Per Year 

UNFCC United Nations Framework Convention on 

Climate Change 

VOC Volatile Organic Compound 

II. Overview of the Final Rule 

EPA is relieving overwhelming permitting burdens that 

would, in the absence of this rule, fall on permitting 

authorities and sources. We accomplish this by tailoring the 

applicability criteria that determine which GHG emission sources 
10

become subject to the PSD and title V programs1 of the CAA. In 

particular, EPA is establishing with this rulemaking a phase-in 

approach for PSD and title V applicability, and is establishing 

the first two steps of the phase-in for the largest emitters of 

GHGs. We also commit to certain follow-up actions regarding 

future steps beyond the first two, discussed in more detail 

later. Our legal basis for this rule is our interpretation of 

the PSD and title V applicability provisions under the familiar 

Chevron two-step framework for interpreting administrative 

statutes, taking account of three legal doctrines, both 

separately and interdependently: they are what we will call (i) 

the “absurd results” doctrine, which authorizes agencies to 

apply statutory requirements differently than a literal reading 

would indicate, as necessary to effectuate congressional intent 

and avoid absurd results, (ii) the “administrative necessity” 

doctrine, which authorizes agencies to apply statutory 

requirements in a way that avoids impossible administrative 

burdens; and (iii) the “one-one-step-at-a-time” doctrine, which 

authorizes agencies to implement statutory requirements a step 

 1

 Unless otherwise indicated, references in this preamble to 

“title V,” “title V requirements,” the “title V program,” and 

similar references are to the operating permit provisions in CAA 

sections 501-506, and not the “small business stationary source 

technical and environmental compliance assistance program” under 

CAA section 507. 
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at a time. This legal basis justifies each of the actions we 

take with this rule, both (i) as part of the overall tailoring 

approach and (ii) independently of the other actions. EPA also 

has authority for this tailoring rule under CAA section 

301(a)(1), which authorizes the Administrator “to prescribe 

“such regulations as are necessary to carry out his functions 

under [the CAA].” 

For the first step of this Tailoring Rule, which will begin 

on January 2, 2011, PSD or title V requirements will apply to 

sources’ GHG emissions only if the sources are subject to PSD or 

title V anyway due to their non-GHG conventional pollutants. 

Therefore, EPA will not require sources or modifications to 

evaluate whether they are subject to PSD or title V requirements 

solely on account of their GHG emissions. Specifically, for 

PSD, Step 1 requires that as of January 2, 2011, the applicable 

requirements of PSD, most notably, the best available control 

technology (BACT) requirement, will apply to projects that 

increase net GHG emissions by at least 75,000 tpy carbon dioxide 

equivalent (CO2e), but only if the project also significantly 

increases emissions of at least one non-GHG pollutant. For the 

title V program, only existing sources with, or new sources 

obtaining, title V permits for non-GHG pollutants will be 

required to address GHGs during this first step. 
12

The second step of the Tailoring Rule, beginning on July 1, 

2011, will phase-in additional large sources of GHG emissions. 

New sources as well as existing sources not already subject to 

title V that emit, or have the potential to emit, at least 

100,000 tpy CO2e will become subject to the PSD and title V 

requirements. In addition, sources that emit or have the 

potential to emit at least 100,000 tpy CO2e and that undertake a 

modification that increases net emissions of GHGs by at least 

75,000 tpy CO2e will also be subject to PSD requirements. For 

both steps, we also note that if sources or modifications exceed 

these CO2e-adjusted GHG triggers, they are not covered by 

permitting requirements unless their GHG emissions also exceed 

the corresponding mass-based triggers (i.e., unadjusted for 

CO2e.) 

EPA believes that the costs to the sources and the 

administrative burdens to the permitting authorities of PSD and 

title V permitting will be manageable at the levels in these 

initial two steps, and that it would be administratively 

infeasible to subject additional sources to PSD and title V 

requirements at those times. However, we also intend to issue a 

supplemental notice of proposed rulemaking (SNPR) in 2011, in 

which we will propose or solicit comment on a third step of the 

phase-in that would include more sources, beginning by July 1, 
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2013. In the same rulemaking, we may propose or solicit comment 

on a permanent exclusion from permitting for some category of 

sources, based on the doctrine of “absurd results,” within the 

Chevron framework. We are establishing an enforceable 

commitment that we will complete this rulemaking by July 1, 

2012, which will allow for 1 year's notice before step 3 would 

take effect. 

In addition, we commit to explore streamlining techniques 

that may well make the permitting programs much more efficient 

to administer for GHGs, and that therefore may allow their 

expansion to smaller sources. We expect that the initial 

streamlining techniques will take several years to develop and 

implement. 

We are also including in this action a rule that no source 

with emissions below 50,000 tpy CO2e, and no modification 

resulting in net GHG increases of less than 50,000 tpy CO2e, will 

be subject to PSD or title V permitting before at least 6 years 

from now, April 30, 2016. This is because we are able to 

conclude at the present time that the administrative burdens 

that would accompany permitting sources below this level will be 

so great that even the streamlining actions that EPA may be able 

to develop and implement in the next several years, and even 

with the increases in permitting resources that we can 
14

reasonably expect the permitting authorities to acquire, it will 

be impossible to administer the permit programs for these 

sources until at least 2016. 

Further, we are establishing an enforceable commitment that 

we will (i) complete a study by April 30, 2015, to evaluate the 

status of PSD and title V permitting for GHG-emitting sources, 

including progress in developing streamlining techniques; and 

(ii) complete further rulemaking based on that study by April 

30, 2016, to address the permitting of smaller sources. That 

rulemaking may also consider additional permanent exclusions 

based on the “absurd results” doctrine, where applicable. 

This tailoring rulemaking is necessary because without it, 

PSD and title V would apply to all stationary sources that emit 

or have the potential to emit more than 100 or 250 tons of GHGs 

per year beginning on January 2, 2011. This is the date when 

EPA’s recently promulgated Light Duty Vehicle Rule (LDVR) takes 

effect, imposing control requirements for the first time on 

carbon dioxide (CO2) and other GHGs. If this January 2, 2011 

date were to pass without this tailoring rule being in effect, 

PSD and title V requirements would apply at the 100/250 tpy 

applicability levels provided under a literal reading of the CAA 

as of that date. From that point forward, a source owner 

proposing to construct any new major source that emits at or 
15

higher than the applicability levels (and which therefore may be 

referred to as a “major” source) or modify any existing major 

source in a way that would increase GHG emissions would need to 

obtain a permit under the PSD program that addresses these 

emissions before construction or modification could begin. 

Similarly, title V would apply to a new or existing source 

exceeding the 100 tpy applicability level in the Act, if the 

source did not already have a title V permit. 

Under these circumstances, many small sources would be 

burdened by the costs of the individualized PSD control 

technology requirements and permit applications that the PSD 

provisions, absent streamlining, require. Additionally, state 

and local permitting authorities would be burdened by the 

extraordinary number of these permit applications, which are 

orders of magnitude greater than the current inventory of 

permits and would vastly exceed the current administrative 

resources of the permitting authorities. Permit gridlock would 

result with the permitting authorities able to issue only a tiny 

fraction of the permits requested. 

These impacts – the costs to sources and administrative 

burdens to permitting authorities – that would result from 

application of the PSD and title V programs for GHG emissions at 

the statutory levels as of January 2, 2011, are so severe that 
16

they bring the judicial doctrines of “absurd results,” 

“administrative necessity,” and “one-step-at-a-time” into the 

Chevron two-step analytical framework for statutes administered 

by agencies. Under the U.S. Supreme Court’s decision in 

Chevron, the agency must, at step 1, determine whether 

Congress’s intent as to the specific matter at issue is clear, 

and, if so, the agency must give effect to that intent. Chevron 

U.S.A. Inc. v. NRDC, 467 U.S. 837, 842-43 (1984). If 

congressional intent is not clear, then, at step 2, the agency 

has discretion to fashion an interpretation that is a reasonable 

construction of the statute. To determine congressional intent, 

the agency must first consider the words of the statutory 

requirements, and if their literal meaning answers the question 

at hand, then, in most cases, the agency must implement those 

requirements by their terms. However, under the “absurd 

results” doctrine, the literal meaning of statutory requirements 

should not be considered to indicate congressional intent if the 

plain meaning would produce a result that is senseless or that 

is otherwise inconsistent with -- and especially one that 

undermines -- underlying congressional purpose. In these cases, 

if congressional intent for how the requirements apply to the 

question at hand is clear, the agency should implement the 

statutory requirements not in accordance with their plain 
17

meaning, but rather in a manner that most closely effectuates 

congressional intent. If congressional intent is not clear, 

then an agency may select an interpretation that is reasonable 

under the statute. Similarly, under the “administrative 

necessity” doctrine, Congress is presumed, at Chevron step 1, to 

intend that its statutory directives to agencies be 

administratible, and not to have intended to have written 

statutory requirements that are impossible to administer. 

Therefore, under this doctrine, an agency may depart from 

statutory requirements that, by their terms, are impossible to 

administer, but the agency may depart no more than necessary to 

render the requirements administrable. Under the “one-step-ata-time” doctrine, Congress is presumed at Chevron step 1 to have 

intended to allow the agency to administer the statutory 

requirements on a step-by-step basis, as appropriate, when the 

agency remains on track to implement the requirements as a 

whole. Each of these doctrines supports our action separately, 

but the three also are intertwined and support our action in a 

comprehensive manner. 

Here, we have determined, through analysis of burden and 

emissions data as well as consideration of extensive public 

comment, that the costs to sources and administrative burdens to 

permitting authorities that would result from application of the 
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PSD and title V programs for GHG emissions at the statutory 

levels as of January 2, 2011 should be considered “absurd 

results.” Therefore, we conclude that under the “absurd 

results” doctrine, Congress could not have intended that the 

statutory levels apply to GHG sources as of that date. The 

“administrative necessity” doctrine supports our conclusion as 

well because the administrative burdens of attempting to comply 

with the statutory thresholds as of January 2, 2011 would be 

impossible to bear, and for this reason, too, Congress could not 

have intended that the statutory levels apply as of that date. 

We conclude that applying PSD and title V to GHG sources as 

a general matter is consistent with congressional intent – that 

is, that Congress did express an intent on whether the two 

permitting programs applied to GHG sources, and the intent was 

in the affirmative -- but that Congress did not express an 

intent on how to apply PSD and title V to GHG sources. As a 

result, we believe that we have authority to develop an approach 

that is reasonable under the PSD and title V provisions, and we 

believe that the tailoring approach so qualifies. As a result, 

the Tailoring Rule is valid under Chevron, as informed by the 

“absurd results,” “administrative necessity,” and “one-step-ata-time” doctrines. Even so, we acknowledge that it may not be 

clear whether Congress would have intended that PSD and title V 
19

apply to the smallest GHG sources – those at or near the 

statutory levels -- or, if congressional intent is unclear in 

this regard, whether it is reasonable to apply PSD and title V 

to the smallest sources in light of the statutory requirements. 

We expect to resolve this issue through future rulemaking. In 

addition, with respect to title V, we acknowledge that it may 

not be clear whether Congress intended that large numbers of GHG 

sources be required to hold permits that do not have applicable 

requirements – which we will call “empty permits” – and we 

intend to resolve this issue, too, in future rulemaking. 

The legal analysis just describes justifies each of the 

actions in this rule. The first two steps that we promulgate in 

this rule, which take effect on January 2, 2011 and July 1, 

2011, constitute the most that permitting authorities can 

reasonably be expected to do by those times. Similarly, the 

50,000 tpy floor that we promulgate through at least April 30, 

2016 is reasonable because the information we have available now 

shows that it constitutes the most that permitting authorities 

can reasonably be expected to do by that date. Finally, the 

study and two additional rulemakings – to take effect by July 1, 

2013 and April 30, 2016 -- to which we commit in this rule 

establish a track for acquiring additional information and for 

taking further steps to address the application of PSD and title 
20

V more closely to the literal statutory levels. We intend to 

apply them as closely to those levels as is consistent with 

congressional intent and administrative imperatives, in light of 

the “absurd results,” “administrative necessity,” and “one-stepat-a-time” doctrines, although, as noted previously, we may 

consider in future rulemaking whether to conclude that Congress 

did not intend that the programs apply to the smallest sources 

or, for title V, sources with empty permits. 

We are adopting regulatory language codifying our phase-in 

approach. As we will explain, many state, local and tribal area 

programs will likely be able to immediately implement our 

approach without rule or statutory changes by, for example, 

interpreting the term ”subject to regulation” that is part of 

the applicability provisions for PSD and title V. We ask 

permitting authorities to confirm that they will follow this 

implementation approach for their programs, and if they cannot, 

then we will ask them to notify us so that we can take 

appropriate follow-up action to narrow our federal approval of 

their programs before GHGs become subject to regulation for PSD 

and title V programs on January 2, 2011. Narrowing our approval 

will ensure that for federal purposes, GHG sources below the 

size thresholds we establish in this Tailoring Rule are not 

obligated to hold PSD or title V permits until the states 
21

develop and submit revised PSD and title V programs for these 

smaller GHG sources, and EPA approves those programs on grounds 

that the states have demonstrated that they have adequate 

resources to administer those programs. 

The thresholds we are establishing are based on CO2e for the 

aggregate sum of six greenhouse gases that constitute the 

pollutant that will be subject to regulation, which we refer to 

as GHGs.2 These gases are: CO2, methane (CH4), nitrous oxide 

(N2O), hydrofluorocarbons (HFCs), perfluorocarbons (PFCs), and 

sulfur hexafluoride (SF6). Thus, in this rule, we provide that 

PSD and title V applicability is based on the quantity that 

results when the mass emissions of each of these gases is 

multiplied by the Global Warming Potential (GWP) of that gas, 

and then summed for all six gases. However, we further provide 

that in order for a source’s GHG emissions to trigger PSD or 

title V requirements, the quantity of the GHGs must equal or 

exceed both the applicability thresholds established in this 

rulemaking on a CO2e basis and the statutory thresholds of 100 or 

 2

 The term “greenhouse gases” is commonly used to refer 

generally to gases that have heat-trapping properties. However, 

in this notice, unless noted otherwise, we use it to refer to 

specifically to the pollutant regulated in the LDVR. 
22

250 tpy on a mass basis.3 Similarly, in order for a source to be 

subject to the PSD modification requirements, the source’s net 

GHG emissions increase must exceed the applicable significance 

level on a CO2e basis and must also result in a net mass increase 

of the constituent gases combined. 

We are adopting this rule after careful consideration of 

numerous public comments. On October 27, 2009 (74 FR 55292), 

EPA proposed the GHG Tailoring Rule. EPA held two public 

hearings on the proposed rule, and received over 400,000 written 

public comments. The public comment period ended on December 

28, 2009. The comments have provided detailed information that 

has helped EPA understand better the issues and potential 

impacts of this rule, and the final rule described in this 

preamble incorporates many of the suggestions we received. We 

respond to many of these comments in explaining our rationale 

for the final rule, which is described in section V. The final 

rule adopts many elements of the proposal but differs from the 

proposal in several important respects. We proposed to apply 

PSD and title V to GHG sources that emit or have the potential 

to emit at least 25,000 tpy CO2e, and we proposed a PSD 

significance level in a range between 10,000 and 25,000 tpy CO2e, 

 3

 The relevant thresholds are 100 tpy for title V, and 250 

tpy for PSD except for 28 categories listed in EPA regulations 

for which the PSD threshold is 100 tpy. 
23

but based on consideration of the additional information we 

received and our further analysis, we are finalizing the 

threshold levels in the amount and on the schedule described 

previously. In addition, the mechanism for state, local, and 

tribal program implementation has been significantly changed to 

reflect the comments received that we needed to develop an 

implementation approach that states could adopt under state law 

more expeditiously. 

 The remainder of this notice describes our approach and 

rationale in more detail. Following this overview, section III 

of this preamble provides background information on the nature 

of GHG emissions, recent regulatory developments that affect 

when and how GHG emissions are subject to stationary source 

permitting, and the general requirements of the PSD and title V 

programs. Section IV describes in detail the summary of the key 

actions being taken in this rule, including the determination of 

emissions, the thresholds and timing for the phase-in, our 

approach to implementing the phase-in, and the additional future 

actions we will take. Section V provides a more detailed 

description of each action, explaining the policy and legal 

rationale and responding to comments received. Section V begins 

with our decisions on how to calculate the mass-based and CO2ebased emissions used in the phase-in. Section V then turns to 
24

our legal and policy rationale for the first two steps of the 

phase-in, the 50,000 tpy floor, and the subsequent study and 

rulemakings to determine whether and how smaller sources should 

be subject to permitting. This section then describes key 

implementation issues including the approach to state adoption. 

After describing our plans for follow-up on title V fee 

programs, the section concludes by describing permit 

streamlining techniques; guidance on BACT for the GHG sources 

that are affected under the first two steps of the Tailoring 

Rule phase-in; requests for exemptions; and transitional issues, 

including grandfathering. Finally, section VI describes the 

expected impacts that will result from the phase-in approach 

(i.e, the narrower application of PSD and title V requirements 

during the phase-in period) and section VII addresses 

administrative requirements. 

III. Background 

A. What are greenhouse gases and their sources?

GHGs trap the Earth’s heat that would otherwise escape from 

the atmosphere into space, and forms the greenhouse effect that 

helps keep the Earth warm enough for life. Greenhouse gases are 

naturally present in the atmosphere and are also emitted by 

human activities. Human activities are intensifying the 

naturally occurring greenhouse effect by increasing the amount 
25

of GHGs in the atmosphere, which is changing the climate in a 

way that endangers human health, society, and the natural 

environment. 

Some GHGs such as CO2 are emitted to the atmosphere through 

natural processes as well as human activities. Other gases, 

such as fluorinated gases, are created and emitted solely 

through human activities. As previously noted, the well-mixed 

GHGs of concern directly emitted by human activities include CO2, 

CH4, N2O, HFCs, PFCs, and SF6. These six GHGs will, for the 

purposes of this final rule, be referred to collectively as "the 

six well-mixed GHGs,” or, simply, GHGs. and together constitute 

the “air pollutant” upon which the GHG thresholds in this action 

are based. These six gases remain in the atmosphere for decades 

to centuries where they become well-mixed globally in the 

atmosphere. When they are emitted more quickly than natural 

processes can remove them from the atmosphere, their 

concentrations increase, thus increasing the greenhouse effect. 

The heating effect caused by the human-induced buildup of GHGs 

in the atmosphere is very likely the cause of most of the 

observed global warming over the last 50 years. A detailed 

explanation of climate change and its impact on health, society, 

and the environment is included in EPA's technical support 
26

document (TSD) for the endangerment finding final rule (Docket 

ID No. EPA-HQ-OAR-2009-0472-11292). 

In the United States, the combustion of fossil fuels (e.g., 

coal, oil, gas) is the largest source of CO2 emissions and 

accounts for 80 percent of the total GHG emissions. More than 

half of the energy related emissions come from large stationary 

sources such as power plants, while about a third comes from 

transportation. Of the six well-mixed GHGs, four (CO2, CH4, N2O, 

and HFCs) are emitted by motor vehicles. In the United States 

industrial processes (such as the production of cement, steel, 

and aluminum), agriculture, forestry, other land use, and waste 

management are also important sources of GHGs. 

Different GHGs have different heat-trapping capacities. 

The concept of GWP was developed to compare the heat-trapping 

capacity and atmospheric lifetime of one GHG to another. The 

definition of a GWP for a particular GHG is the ratio of heat 

trapped by one unit mass of the GHG to that of one unit mass of 

CO2 over a specified time period. When quantities of the 

different GHGs are multiplied by their GWPs, the different GHGs 

can be summed and compared on a CO2e basis. For example, CH4 has 

a GWP of 21, meaning each ton of CH4 emissions would have 21 

times as much impact on global warming over a 100-year time 

horizon as 1 ton of CO2 emissions. Thus, on the basis of heat-
27

trapping capability, 1 ton of CH4 would equal 21 tons of CO2e. 

The GWPs of the non CO2 GHGs range from 21 (for CH4) up to 23,900 

(for SF6). Aggregating all GHGs on a CO2e basis at the source 

level allows a facility to evaluate its total GHG emissions 

contribution based on a single metric. 

B. Endangerment Finding and the Light-Duty Vehicle Rule

1. Endangerment Finding 

On April 2, 2007, the United States Supreme Court found 

that GHGs are air pollutants under CAA section 302(g). 

Massachusetts v. EPA, 549 U.S. 497 (2007). As a result, the 

Supreme Court found that EPA was required to determine, under 

CAA section 202(a), whether (a) GHGs from new motor vehicles 

cause or contribute to air pollution which may reasonably be 

anticipated to endanger public health or welfare, or (b) the 

science is too uncertain to make a reasoned decision. After 

issuing a proposal and receiving comment, on December 7, 2009, 

the Administrator signed two distinct findings regarding GHGs 

under CAA section 202(a): 

• Endangerment Finding: The Administrator found that the 

current and projected atmospheric concentrations of the mix 

of six long-lived and directly emitted GHGs—CO2, CH4, N2O, 

HFCs, PFCs, and SF6 (referred to as “well-mixed greenhouse 

gases” in the endangerment finding)–are reasonably 
28

anticipated to endanger the public health and welfare of 

current and future generations. 

• Cause or Contribute Finding: The Administrator found that 

the emissions of the single air pollutant defined as the 

aggregate group of six well-mixed greenhouses gases from 

new motor vehicles and new motor vehicle engines contribute 

to the GHG air pollution that threatens public health and 

welfare. 

These findings, which were published December 15, 2009 (74 FR 

66496), do not themselves impose any requirements on industry or 

other entities. However, they were a prerequisite to finalizing 

the GHG standards for light-duty vehicles, described next. 

2. Light-Duty Vehicle Rule 

The light-duty vehicle rule, signed on April 1, 20104

 is a joint 

rule between EPA and the Department of Transportation’s National 

Highway Traffic Safety Administration (NHTSA) that establishes a 

national program consisting of new standards for light-duty 

vehicles that will reduce greenhouse gas emissions and improve 

fuel economy. EPA finalized the national GHG emissions 

standards under the Act, and NHTSA finalized Corporate Average 

Fuel Economy (CAFE) standards under the Energy Policy and 

 4

 This rule has not yet been published in the Federal 

Register. The signed version of the rule is available at

http://epa.gov/otaq/climate/regulations.htm. [update when 

published] 
29

Conservation Act, as amended. The new standards apply to new 

passenger cars, light-duty trucks, and medium-duty passenger 

vehicles, starting with model year 2012. The EPA GHG standards 

are projected to result in an estimated combined average 

emissions level of 250 grams of CO2 per mile for model year 2016 

vehicles. The standards begin with the 2012 model year, with 

standards increasing in stringency through model year 2016. The 

standards are a fleet average for each manufacturer, based on a 

footprint attribute curve, meaning that the actual target for a 

vehicle will vary depending on the size of the vehicle. Under 

the footprint-based standards, each manufacturer will have a GHG 

standard unique to its fleet, depending on the footprints of the 

vehicle models produced by that manufacturer. A manufacturer 

will have separate footprint-based standards for cars and for 

trucks. 

 The endangerment and contribution findings described 

previously require EPA to issue standards under section 202 (a) 

“applicable to emission” of the air pollutant that EPA found 

causes or contributes to the air pollution that endangers public 

health and welfare. The final emissions standards satisfy this 

requirement for GHGs from light-duty vehicles. Under section 

202(a) the Administrator has significant discretion in how to 

structure the standards that apply to the emission of the air 
30

pollutant at issue here, the aggregate group of six GHGs. EPA 

has the discretion under section 202(a) to adopt separate 

standards for each gas, a single composite standard covering 

various gases, or any combination of these. In the LDVR, EPA 

finalized separate standards for N2O and CH4, and a CO2 standard 

that provides for credits based on reductions of HFCs, as the 

appropriate way to issue standards applicable to emission of the 

single air pollutant, the aggregate group of six GHGs. EPA did 

not set any standards for PFCs or SF6, as they are not emitted by 

motor vehicles. 

C. What are the general requirements of the PSD program?

1. Overview of the PSD Program 

The PSD program is a preconstruction review and permitting 

program applicable to new major stationary sources and major 

modifications at existing major stationary sources. The PSD 

program applies in areas that are designated “attainment” or 

“unclassifiable” for a National Ambient Air Quality Standard 

(NAAQS). The PSD program is contained in part C of title I of 

the CAA. The "nonattainment new source review (NSR)" program 

applies in areas not in attainment for a NAAQS or in the Ozone 

Transport Region and is implemented under the requirements of 

part D of title I of the CAA. Collectively, we commonly refer 

to these two programs as the major NSR program. The governing 
31

EPA rules are contained in 40 CFR 51.165, 51.166, 52.21, 52.24, 

and part 51, appendices S and W. There is no NAAQS for CO2 or 

any of the other well-mixed GHGs, nor has EPA proposed any such 

NAAQS; therefore, unless and until we take further such action, 

we do not anticipate that the "nonattainment" major NSR program 

will apply to GHGs. 

The applicability of PSD to a particular source must be 

determined in advance of construction or modification and is 

pollutant-specific. The primary criterion in determining PSD 

applicability for a proposed source is whether the source is a 

“major emitting facility,”, based on its predicted potential 

emissions of regulated pollutants, within the meaning of CAA 

section 169(1) and either constructs or undertakes a 

modification. EPA has implemented these requirements in its 

regulations, which use somewhat different terminology for 

determining PSD applicability, which is whether the source is a 

“major stationary source” or whether the proposed project is a 

“major modification.” 

a. Major Stationary Source 

Under PSD, a "major stationary source" is any source 

belonging to a specified list of 28 source categories which 

emits or has a potential to emit (PTE) of 100 tpy or more of any 

pollutant subject to regulation under the CAA, or any other 
32

source type which emits or has the PTE such pollutants in 

amounts equal to or greater than 250 tpy. We refer to these 

levels as the 100/250-tpy thresholds. A new source with a PTE 

at or above the applicable “major stationary source threshold" 

is subject to major source NSR. These limits originate from 

section 169 of the CAA, which applies PSD to any “major emitting 

facility” and defines the term to include any source that emits 

or has a PTE of 100 or 250 tpy, depending on the source 

category. Note that the major source definition incorporates 

the phrase “subject to regulation,” which, as described later, 

will begin to include GHGs on January 2, 2011, under our 

interpretation of that phrase discussed in the recent 

Interpretive Memo notice. 75 FR 17004. 

b. Major Modifications 

PSD also applies to existing sources that undertake a 

"major modification," which occurs: (1) when there is a 

physical change in, or change in the method of operation of, a 

"major stationary source;" (2) the change results in a 

"significant" emission increase of a pollutant subject to 

regulation (equal to or above the significance level that EPA 

has set for the pollutant in 40 CFR 52.21(b)(23)); and (3) there 

is a “significant net emissions increase” of a pollutant subject 

to regulation that is equal to or above the significance level 
33

(defined in 40 CFR 52.21(b)(23)). Significance levels, which 

EPA has promulgated for criteria pollutants and certain other 

pollutants, represent a de minimis contribution to air quality 

problems. When EPA has not set a significance level for a 

regulated NSR pollutant, PSD applies to an increase of the 

pollutant in any amount (that is, in effect, the significance 

level is treated as zero). 

2. General Requirements for PSD 

This section provides a very brief summary of the main 

requirements of the PSD program. One principal requirement is 

that a new major source or major modification must apply BACT, 

which is determined on a case-by-case basis taking into account, 

among other factors, the cost effectiveness of the control and 

energy and environmental impacts. EPA has developed a “topdown” approach for BACT review, which involves a decision 

process that includes identification of all available control 

technologies, elimination of technically infeasible options, 

ranking of remaining options by control and cost effectiveness, 

and then selection of BACT. Under PSD, once a source is 

determined to be major for any regulated NSR pollutant, a BACT 

review is performed for each attainment pollutant that exceeds 

its PSD significance level as part of new construction or for 

modification projects at the source, where there is a 
34

significant increase and a significant net emissions increase of 

such pollutant5

. 

In addition to performing BACT, the source must analyze 

impacts on ambient air quality to assure that no violation of 

any NAAQS or PSD increments will result, and must analyze 

impacts on soil, vegetation, and visibility. In addition, 

sources or modifications that would impact Class I areas (e.g., 

national parks) may be subject to additional requirements to 

protect air quality related values (AQRVs) that have been 

identified for such areas. Under PSD, if a source’s proposed 

project may impact a Class I area, the Federal Land Manager is 

notified and is responsible for evaluating a source’s projected 

impact on the AQRV’s and recommending either approval or 

disapproval of the source’s permit application based on 

anticipated impacts. There are currently no NAAQS or PSD 

increments established for GHGs, and therefore these PSD 

requirements would not apply for GHGs, even when PSD is 

triggered for GHGs. However, if PSD is triggered for a GHG 

emissions source, all regulated NSR pollutants which the new 

source emits in significant amounts would be subject to PSD 

 5

 We note that the PSD program has historically operated in 

this fashion for all pollutants – when new sources or 

modifications are “major”, PSD applies to all pollutants that 

are emitted in significant quantities from the source or 

project. This rule does not alter that for sources or 

modifications that are major due to their GHG emissions. 
35

requirements. Therefore, if a facility triggers review for 

regulated NSR pollutants that are non-GHG pollutants for which 

there are established NAAQS or increments, the air quality, 

additional impacts, and Class I requirements would apply to 

those pollutants. 

The permitting authority must provide notice of its 

preliminary decision on a source's application for a PSD permit, 

and must provide an opportunity for comment by the public, 

industry, and other interested persons. After considering and 

responding to comments, the permitting authority must issue a 

final determination on the construction permit. Usually NSR 

permits are issued by state or local air pollution control 

agencies, which have their own permit programs approved by EPA 

in their SIP. In some cases, EPA has delegated its authority to 

issue PSD permits to the state or local agency. In other areas, 

EPA issues the permits under its own authority. 

D. What are the general requirements of the title V operating 

permits program?

1. Overview of Title V 

The operating permit requirements under title V are 

intended to improve sources' compliance with other CAA 

requirements. The title V program is implemented through 

regulations promulgated by EPA, 40 CFR part 70, for programs 
36

implemented by state and local agencies and tribes, and 40 CFR 

part 71, for programs generally implemented by EPA. 

In summary, the title V program requires major sources 

(defined and interpreted by EPA to include sources that emit or 

have PTE of 100 tpy of any pollutant subject to regulation) and 

certain other sources to apply for operating permits. Under 

EPA’s long-standing interpretation, a pollutant, such as a GHG, 

is “subject to regulation” when it is subject to a CAA 

requirement establishing actual control of emissions. Title V 

generally does not add new pollution control requirements, but 

it does require that each permit contain all pollution control 

requirements or “applicable requirements” required by the CAA 

(e.g., New Source Performance Standard (NSPS), and State 

Implementation Plan (SIP) requirements, including PSD), and it 

requires that certain procedural requirements be followed, 

especially with respect to compliance with these requirements. 

"Applicable requirements" for title V purposes include 

stationary source requirements, but do not include mobile source 

requirements. Other procedural requirements include providing 

review of permits by EPA, states, and the public, and requiring 

permit holders to track, report, and annually certify their 

compliance status with respect to their permit requirements. 

2. Title V Permit Requirements 
37

This section provides a brief summary of the requirements 

of the title V program that are most relevant to this action. A 

source generally must apply for a title V permit within 1 year 

of first becoming subject to permitting – for new sources, this 

is usually within 1 year of commencing operation. The 

application must include, among other things, identifying 

information, a description of emissions and other information 

necessary to determine applicability of requirements and 

information concerning compliance with those requirements. The 

permitting authority uses this information to develop the 

source's operating permit. 

Title V permits generally contain the following elements: 

(1) emissions limitations and standards to assure compliance 

with all applicable requirements; (2) monitoring, recordkeeping, 

and reporting requirements, including submittal of a semiannual 

monitoring report and prompt reporting of deviations from permit 

terms; (3) fee payment; and (4) an annual certification of 

certification by a responsible official. The detailed 

requirements are set forth at 40 CFR 70.6. 

In addition to the permit content requirements, there are 

procedural requirements that must be followed in issuing title V 

permits, including (1) application completeness determination; 

(2) public notice and a 30-day public comment period, including 
38

an opportunity for a public hearing, on draft permits; (3) EPA 

and affected state review; and (4) a statement of the legal and 

factual basis of the draft permit. The permitting authority 

must take final action (issue or deny) on the permit 

applications within 18 months of receipt. EPA also has 45 days 

from receipt of a proposed permit to object to its issuance, and 

citizens have 60 days after that to petition EPA to object to a 

permit. Permits may also need to be revised or reopened if new 

requirements come into effect during the permit terms or if the 

source makes changes that conflict with, or necessitate changes 

to, the current permit. Permit revisions and re-openings follow 

procedural requirements which vary depending on the nature of 

the necessary change to the permit. 

E. The Interpretive Memorandum 

 On December 18, 2008, EPA issued a memorandum, "EPA's 

Interpretation of Regulations that Determine Pollutants Covered 

by Federal Prevention of Significant Deterioration (PSD) Permit 

Program" (known as the “Johnson Memo” or the “PSD Interpretive 

Memo,” and referred to in this preamble as the “Interpretive 

Memo”) that set forth EPA’s interpretation regarding which EPA 

and state actions, with respect to a previously unregulated 

pollutant, cause that pollutant to become “subject to 

regulation” under the Act. Whether a pollutant is “subject to 
39

regulation” is important for the purposes of determining whether 

it is covered under the federal PSD and title V permitting 

programs. The Interpretive Memo established that a pollutant is 

“subject to regulation” only if it is subject to either a 

provision in the CAA or regulation adopted by EPA under the CAA 

that requires actual control of emissions of that pollutant 

(referred to as the “actual control interpretation”). On 

February 17, 2009, EPA granted a petition for reconsideration on 

the Interpretive Memo, and announced its intent to conduct a 

rulemaking to allow for public comment on the issues raised in 

the memorandum and on related issues. EPA also clarified that 

the Interpretive Memo would remain in effect pending 

reconsideration. 

On March 29, 2010, EPA signed a notice conveying its 

decision to continue applying (with one limited refinement) the 

Interpretive Memo’s interpretation of “subject to regulation” 

(“Interpretation of Regulations that Determine Pollutants 

Covered by Clean Air Act Permitting Programs“). See 75 FR 

17004. EPA concluded that the “actual control interpretation” 

is the most appropriate interpretation to apply given the policy 

implications. However, we refined our interpretation in one 

respect: we established that PSD permitting requirements apply 

to a newly regulated pollutant at the time a regulatory 
40

requirement to control emissions of that pollutant “takes 

effect” (rather than upon promulgation or the legal effective 

date of the regulation containing such a requirement). In 

addition, based on the anticipated promulgation of the LDVR, we 

stated that the GHG requirements of the vehicle rule would take 

effect on January 2, 2011, because that is the earliest date 

that a 2012 model year vehicle may be introduced into commerce. 

In other words, the compliance obligation under the LDVR does 

not occur until a manufacturer may introduce into commerce 

vehicles that are required to comply with GHG standards, which 

will begin with model year 2012 and will not occur before 

January 2, 2011. We also reiterated EPA’s interpretation that 

the 100 tpy major source threshold for title V is triggered only 

by pollutants “subject to regulation” under the Act, and we 

defined and applied that term for title V purposes in the same 

way that we did for PSD purposes. That is, we stated that a 

pollutant is “subject to regulation” if it is subject to a CAA 

requirement establishing “actual control of emissions;” that a 

pollutant is considered “subject to regulation” for title V 

purposes when such a requirement “takes effect”; and, based on 

the anticipated promulgation of the LDVR, that the GHG 

requirements of the vehicle rule would take effect on January 2, 

2011. 
41

On April 1, 2010, we finalized the LDVR as anticipated, 

confirming that manufacturer certification can occur no earlier 

than January 2, 2011. Thus, under the terms of the final notice 

for the Interpretive Memo, GHGs become subject to regulation on 

that date, and PSD and title V program requirements will also 

begin to apply upon that date. 

IV. Summary of Final Actions 

This section describes the specific actions we are taking 

in this final rule. It describes the overall tailoring approach 

for NSR and title V applicability, the steps we are taking to 

put it into place, and future actions that we commit to take. 

The next section, V, provides the legal and policy rationale for 

these actions. In that section, we provide a description of our 

rationale and response to comments for each action, presented in 

the same order as we describe the actions later. 

A. How do you define the GHG pollutant for PSD and title V 

purposes?

1. GHG Pollutant Defined as the Sum-of-Six Well-Mixed GHGs 

We are identifying the air pollutant for purposes of PSD 

and title V applicability to be the pollutant subject to 

regulation, which is the air pollutant for GHGs identified in 

EPA’s LDVR, as well as EPA’s endangerment and contribution 
42

findings6. In the LDVR, EPA set emissions standards under 

section 202(a) that were “applicable to emission” of a single 

air pollutant defined as the aggregate sum of six greenhouse 

gases. The six GHGs, which are well-mixed gases in the 

atmosphere, are CO2, CH4, N2O, HFCs, PFCs, and SF6. Earlier, EPA 

made the contribution finding for this single air pollutant. 

Furthermore, as proposed, we are using an emissions 

threshold that allows all six constituent gases to be evaluated 

using a common metric – CO2e. Thus, to determine applicability, 

a source's GHG emissions are calculated on a CO2e basis by 

multiplying the mass emissions of any of the six GHGs that the 

source emits by that gas’s GWP and then summing the CO2e for each 

GHG emitted by the source. This sum, expressed in terms of tpy 

CO2e, is then compared to the applicable CO2e-based permitting 

threshold to determine whether the source is subject to PSD and 

title V requirements. 

In addition, because we are implementing this phase-in 

through the term “subject to regulation” the rule is structured 

such that the statutory mass-based thresholds (i.e. 100/250 tpy)7

and 0 tpy for modifications at a major stationary source apply 

 6

 See 74 FR 66496, 66499, 66536-7. December 15, 2009. 

7

 A source need not meet the 100/250 thresholds for GHGs if 

it is already a major stationary source as a result of emissions 

of another regulated NSR pollutant. 
43

and stationary sources or modifications that do not meet these 

thresholds are not subject to permitting requirements. While 

technically evaluation of the mass-based thresholds is the 

second step in the applicability analysis, from a practical 

standpoint most source are likely to treat this as an initial 

screen and not evaluate emissions on a CO2 e basis if they would 

not trigger PSD on a mass basis and we have treated it as such 

in our descriptions later. As applicable, a source would 

evaluate these mass-based thresholds by summing each of the six 

GHGs it emits on a mass basis (i.e., before applying GWP). We 

expect that it will be very rare for a new stationary source or 

modification to trigger permitting based on CO2e and not also 

trigger based on mass alone. 

 Determining permit program applicability for the GHG “air 

pollutant” by using the sum-of-six GHGs is based on EPA’s 

interpretation that the PSD and title V requirements apply to 

each “air pollutant” that is “subject to regulation” under 

another provision of the CAA. As discussed previously, the 

final LDVR for GHGs makes it clear that the emissions standards 

EPA adopted are standards applicable to emission of the single 

air pollutant defined as the aggregate mix of these six wellmixed greenhouse gases. See April 1, 2010 Preamble, II.A.2.c., 
44

pp 153-4., and 40 CFR 86.1818-12.8 For reasons explained in more 

detail in section V, we have determined it is legally required, 

and preferable from a policy standpoint, for EPA to use the same 

definition of the air pollutant for permitting purposes as that 

used in the rule that establishes the control requirements for 

the pollutant. We also believe there are implementation 

advantages for applying PSD and title V in this way. Thus, this 

rule establishes that a stationary source will use the group of 

six constituent gases for permitting applicability, rather than 

treating each gas individually. Similarly, you will include all 

six constituent gases because that is how the air pollutant is 

defined, even though motor vehicles only emit four of the six. 

2. What GWP values should be used for calculating CO2e? 

We are requiring that wherever you perform an emissions 

calculations involving CO2e for the purposes of determining the 

applicability of PSD or title V requirements, you use the GWP 

values codified in the EPA’s GHG mandatory reporting rule 

[Reference: Table A-1 to Subpart A of Part 98 – Global Warming 

Potentials, FR, Vol.74, No. 209, p. 56395]. This approach will 

assure consistency between the values required for calculations 

 8

 40 CFR 86.1818-12 (a) (“Applicability. This section 

contains standards and other regulations applicable to the 

emission of the air pollutant defined as the aggregate group of 

six greenhouse gases: carbon dioxide, nitrous oxide, methane, 

hydrofluorocarbons, perfluorocarbons, and sulfur hexafluoride”). 
45

under the mandatory reporting rule and for PSD or title V. In 

addition, because any changes to Table A-1 of the mandatory GHG 

reporting rule regulatory text must go through a rulemaking, 

this approach will assure that the values used for the 

permitting programs will reflect the latest values adopted for 

usage by EPA after notice and comment. 

B. When will PSD and title V applicability begin for GHGs and 

emission sources?

Overview 

 In this action, we establish the first two phases of our 

phase-in approach, which we refer to as steps 1 and 2. We also 

commit to a subsequent rulemaking in which we will propose or 

solicit comment on establishing a further phase-in, that is, a 

step 3, that would apply PSD and title V to additional sources, 

effective July 1, 2013, and on which we commit to take final 

action, as supported by the record,9

 by no later than July 1, 

2012. 

We also commit to undertaking an assessment of sources’ and 

permitting authorities’ progress in implementing PSD and title V 

 9

 Although we commit to propose or solicit comment on lower 

thresholds and to take final action on that proposal by July 1, 

2012, we cannot, at present, commit to promulgate lower 

thresholds. It will not be until the Step 3 rulemaking itself 

that we will gather and analyze data and receive comments that 

determine whether we have basis for promulgating lower 

thresholds. 
46

for GHG sources, and to complete this assessment by 2015. We 

further commit to completing another round of rulemaking 

addressing smaller sources by April 30, 2016. Our action in 

that rulemaking would address permitting requirements for 

smaller sources, taking into account the remaining problems 

concerning costs to sources and burdens to permitting 

authorities. Finally, we determine in this action that we will 

apply PSD or title V requirements to sources that emit GHGs, or 

that conduct modifications that result in increases in emissions 

of GHGs, in amounts of less than 50,000 tpy CO2e any earlier than 

when we take the required further action to address smaller 

sources by April 30, 2016. 

Through this process, we will implement the phase-in 

approach by applying PSD and title V at threshold levels that 

are as close to the statutory levels as possible, and do so as 

quickly as possible, at least to a certain point. The level and 

timing of the thresholds that we promulgate in future actions 

will be based on our assessment of the resulting costs to 

sources and burdens to permitting authorities, and that, in 

turn, will depend on such variables as our progress in 

developing streamlining approaches and on permitting 

authorities’ progress in developing permitting expertise and 

acquiring more resources. At this time, we cannot foresee 
47

exactly when or in what manner those developments will occur. 

Therefore, we cannot promulgate more components of the tailoring 

approach beyond what we promulgate in this action. We can say 

only that we may continue the phase-in process with further 

rulemaking after 2016. Alternatively, we may make a definitive 

determination in one of the future rulemaking actions that, 

under the “absurd results” doctrine, PSD or title V applies only 

to certain GHG sources, and does not apply to the remaining GHG 

sources, and with that rulemaking, bring this tailoring process 

to a close. 

1. What are the Step 1 thresholds, timing, and calculation 

methodology? 

a. PSD Permitting 

Step 1 of the Tailoring Rule phase-in will begin on January 

2, 2011. With respect to the PSD program, GHG sources will 

become subject to PSD for their GHG emissions if they undergo 

PSD permitting anyway, either for new construction or for 

modification projects, based on emissions of non-GHG pollutants, 

in which case they will be subject to the PSD requirements for 

GHG if they increase GHG emissions by 75,000 tpy CO2e or more. 

Under this step, only these sources, which we refer to as 

“anyway” PSD sources, will become subject to PSD; no sources 

will become major sources for PSD purposes or be treated as 
48

undertaking modifications that trigger PSD based solely on their 

GHG emissions. As a result, no additional PSD permitting 

actions will be necessary solely due to GHG emissions. However, 

existing or newly-constructed sources that are determined to be 

major sources based on non-GHG emissions are required to conduct 

a BACT review for their GHG emissions (from new construction) or 

emissions increases (from modifications), if they are subject to 

PSD due to their non-GHG emissions from construction or 

modification actions and each of the following conditions is 

met: 

1) The GHG emissions (or net emissions increase) due to 

the new construction (or modification) project, calculated as 

the sum of the six well-mixed GHGs on a mass basis (no GWPs 

applied) exceed a value of 0 tpy; and 

2) The GHG emissions (or net emissions increase) due to 

the new construction (or modification) project, calculated as 

the sum of the six well-mixed GHGs on a CO2e basis (GWPs applied) 

equal or exceed a value of 75,000 tpy CO2e. 

The purpose of the first condition is to determine whether 

the GHG emissions or net emissions increase has resulted in an 

“increase in the amount” of an air pollutant as required by the 

Act. Because EPA has not defined a mass-based regulatory 

significance level for GHGs, that level, in effect, is treated 
49

as zero. See 40 CFR 52.21 (b)(23)(ii) and 51.166 (b)(23)(ii). 

In practice, this means any amount of new emissions or an 

emission increase will exceed the mass-based limit. We are not, 

at this time, establishing a significance level based on mass 

emissions because we have established one based on CO2e that 

addresses permitting burdens. Thus, the mass-based step will be 

used only to exclude sources that have no mass increase of GHGs. 

b. Title V Permitting 

Under step 1, only sources required to have title V permits 

for non-GHG pollutants (i.e., “anyway” title V sources) will be 

required to address GHGs as part of their title V permitting. 

That is, no sources will become major for title V based solely 

on their GHG emissions. Note further, however, that the 75,000 

tpy CO2e limit does not apply to title V, so that anyway title V 

sources must apply any title V requirements to their GHG 

emissions. Sources with title V permits must address GHG 

requirements when they apply for, renew, or revise their 

permits. These requirements will include any GHG applicable 

requirements (e.g., GHG BACT requirements from a PSD process) 

and associated monitoring, record-keeping and reporting. When a 

permit application is otherwise required, they will also need to 

identify GHG emissions and other information in that application 

to the extent required under 40 CFR 70.5(c) and 71.5(c), 
50

including information necessary to determine applicable 

requirements.10

2. What are the Step 2 thresholds, timing, and calculation 

methodology? 

a. PSD Permitting 

Step 2 will begin July 1, 2011. Under step 2, anyway PSD 

sources - that is, sources already subject to PSD based on nonGHGs and covered under step 1 previously - will remain subject 

to PSD. In addition, sources with the potential to emit 100,000 

tpy CO2e or more of GHG will be considered major sources for PSD 

permitting purposes (provided that they also emit GHGs or some 

other regulated NSR pollutant above the 100/250 tpy (mass based) 

statutory thresholds. Additionally, any physical change or 

change in the method of operation at a major source (including 

one that is only major due to GHGs) resulting in a net GHG 

emissions increase of 75,000 tpy CO2e or more will be subject to 

PSD review and requirements with respect to GHGs (provided that 

it also results in an increase of GHG emissions on a mass 

basis). 

 10 EPA notes, however, that many sources subject to title V 

under steps 1 and 2 will also be subject to the GHG mandatory 

reporting rule. For these sources, the emissions description 

requirements in the title V regulations will generally be 

satisfied by referencing information provided under the 

reporting rule. 
51

 Specifically, for purposes of determining whether a GHG 

emission source undertaking construction is considered a major 

source under PSD, the following conditions must be met: 

1) The GHG emissions at a newly constructed source which 

is not major for another pollutant, calculated as the sum-ofsix well-mixed GHGs on a mass basis (no GWPs applied): 

- equal or exceed 100 tpy (in actual emissions or 

potential to emit) for sources in any of the 28 major 

emitting facility source categories listed under PSD, or 

- equal or exceed 250 tpy (in actual emissions or 

potential to emit) for any other stationary source. 

2) The GHG emissions at a newly constructed source, 

calculated as the sum-of-six well-mixed GHGs on a mass basis 

(GWPs applied) equal or exceed 100,000 tpy CO2e (on an actual or 

potential to emit basis). 

For determining whether a modification project at a major 

stationary source is subject to PSD review, the following 

conditions must be met: 

1) The net GHG emissions increase resulting from the 

project, calculated as the sum of-six well-mixed GHGs on a mass 

basis (no GWPs applied) equals or exceeds 0 tpy. 
52

2) The net GHG emissions increase resulting from the 

project, calculated as the sum-of-six well-mixed GHGs on a CO2e 

basis (GWPs applied) equals or exceeds 75,000 tpy CO2e. 

The purpose of the first condition in both determinations 

previously is to confirm whether the GHG emissions or emissions 

increase have exceeded, on a mass-basis, the statutory major 

source thresholds (where the source is not otherwise major) and 

mass-based statutory significance level for GHGs, which, as 

noted previously, is 0 tpy. See 40 CFR 52.21 (b)(23)(ii) and 

51.166 (b)(23)(ii). 

As an example of how the mass-based test would apply, 

consider a modification project that results in a 5 tpy increase 

of GHG emissions on a mass basis, associated with a high-GWP GHG 

gas (for example, SF6, with a GWP value of 23,900), but also 

results in a 100 tpy reduction in CO2 emissions (assume no other 

contemporaneous increases or decreases of GHG). In this 

example, there would be a net decrease of GHG emissions on a 

mass basis (5 tpy – 100 tpy = -95 tpy). Because there is no 

mass-based increase of GHG, this project does not trigger PSD, 

despite the fact that the net GWP-adjusted emissions increase of 

SF6 in this example would equal 119,500 tpy of CO2e and the 

project would thus exceed 75,000 tpy CO2e. 

b. Title V Permitting 
53

Under step 2, “anyway” title V sources - that is, sources 

already subject to title V based on non-GHGs and that are 

covered under step 1 previously - will continue to be subject to 

title V. In addition, GHG emission sources that equal or exceed 

the 100,000 tpy CO2e threshold will be required to obtain a title 

V permit if they do not already have one. It is important to 

note that the requirement to obtain a title V permit will not, 

by itself, result in the triggering of additional substantive 

requirements for control of GHG. Rather, these new title V 

permits will simply incorporate whatever applicable CAA 

requirements, if any, apply to the source being permitted. The 

following conditions need to be met in order for title V to 

apply under step 2 to a GHG emission source. 

For determining whether a GHG emission source is subject to 

permitting under title V: 

1) The GHG emissions at an existing or newly constructed 

source, calculated as the sum of the six well-mixed GHGs on a 

mass basis (no GWPs applied), equal or exceed 100 tpy (on an 

actual emission or PTE basis). 

2) The GHG emissions at an existing or newly constructed 

source, calculated as the sum of the six well-mixed GHGs on a 

mass basis (GWPs applied), equal or exceed a value of 100,000 

tpy CO2e (on an actual emission or PTE basis) 
54

3. What about Step 3? 

In this rule, EPA establishes an enforceable commitment to 

complete another rulemaking no later than July 1, 2012, in which 

we will propose or solicit comment on a step 3 of the phase-in 

and may also consider other approaches that may result in the 

permanent exclusion of a category of sources from PSD or title V 

requirements, under the Chevron framework, taking account of the 

“absurd results” doctrine. 

Consistent with our phase-in approach, it is important for 

us to consider whether, at some point during the implementation 

of step 2, it will become possible to administer GHG permitting 

programs for additional sources. For example, if EPA is able to 

promulgate measures that streamline programs to at least some 

extent, if permitting authorities increase their resources, or 

if implementation experience and more seasoned staff results in 

more effective use of scarce permitting resources, then we 

expect that we will be able to phase-in the application of PSD 

and title V to more sources by establishing step 3. We do not 

have enough information now to establish a final step 3, 

particularly because there will be significant transition 

occurring in the GHG permitting programs during steps 1 and 2. 

However, we believe that it will be possible to develop a record 
55

on which to base step 3 sometime soon after we begin to 

implement step 2. 

Therefore, we plan to propose a rule in which we solicit 

comment on or propose lower thresholds for PSD and title V 

applicability, and we establish an enforceable commitment to 

finalize a rule in which we address those matters by July 1, 

2012. In order to provide a year for permitting authorities and 

sources to prepare for any additional GHG permitting action in 

Step 3, we will establish that Step 3 would take effect on July 

1, 2013. We also commit to explore between now and the step 3 

proposal, a wide range of streamlining options. In the 

proposal, we will take comment on streamlining approaches we 

think may be viable (except to the extent we will have already 

issued guidance documents concerning streamlining approaches), 

and we will address those options in the final rule. 

In addition, as part of the step 3 action, we may solicit 

comment on a permanent exclusion of certain sources from PSD, 

title V or both, based on an “absurd results” rationale. For 

example, we may make a final determination that under the 

“absurd results” doctrine, PSD and/or title V do not apply to a 

set of GHG sources that, although above the statutory thresholds 

for those programs, are too small and relatively inconsequential 

in terms of GHG contribution. Another type of such exclusion 
56

for the title V program could be for sources that would 

otherwise be required to obtain an “empty permit,” that is, for 

example, one that would not contain any applicable requirements 

because there are none that apply to the source. It is possible 

that in promulgating a permanent exclusion, we may conclude that 

it brings into the PSD and title V programs the full set of 

sources that would be consistent with congressional intent, and, 

if so, we would find that such a rule brings the tailoring 

process to a close. The application of the “absurd results” 

rationale for a permanent exclusion is discussed in more detail 

in the next section. 

4. What about the proposed 6 year exclusion for smaller 

sources? 

The tailoring proposal contemplated at least a 6-year 

exclusion from permitting for small sources. This proposed 

exclusion was based on the overwhelming numbers of permitting 

actions at small sources and the need for time for permitting 

authorities to secure resources, hire and train staff, and gain 

experience with GHG permitting for new types of sources and 

technologies. It was also based on the time needed for EPA to 

develop, and for states to adopt, streamlining measures to 

reduce the permitting burden (e.g., concerning PTE, presumptive 

BACT, or general permits). We therefore proposed such an 
57

exclusion, and proposed that it would last 6 years – 5 years to 

complete a required study evaluating permitting burden and 

assessing the effect of streamlining measures or techniques in 

reducing this burden, plus an additional year to complete a 

final rulemaking that would phase in additional sources as 

appropriate based on the study. 

 We are finalizing the 6-year exclusion, and for reasons 

described later, are establishing that in no event will sources 

below 50,000 tpy CO2e be subject to PSD or title V permitting 

during the 6-year period, nor will modifications be subject to 

PSD unless they increase emissions by 50,000 tpy CO2e or more. 

The exclusion will last until we take the action described later 

to address smaller sources, which is required by April 30, 2016. 

The exclusion provides certainty that, before this date, EPA 

will not act to cover sources and modifications below these 

thresholds, including during the required step 3 rulemaking that 

will occur in 2012. In effect, this means that step 3 will 

establish a major source threshold and significance level no 

lower than 50,000 tpy CO2e. This does not necessarily mean we 

will cover sources below this level on April 30, 2016. It 

simply means that the provision we are adopting would assure 

that EPA does not cover such sources any sooner than that. 
58

5. When and how will EPA take further action on smaller 

sources? 

As we proposed, we are establishing an enforceable 

commitment to act within 5 years to complete a study projecting 

the administrative burdens that remain for small sources after 

permitting authorities have had time to secure resources, hire 

and train staff, and gain experience with GHG permitting for new 

types of sources and technologies, and after EPA has had time to 

develop (and states have had time to adopt) streamlining 

measures to reduce the permitting burden for such sources. We 

will use this study to serve as the basis for an additional 

rulemaking that would take further action to address small 

sources. Similar to the enforceable commitment to act on step 

3, we are making an enforceable commitment to complete this 

rulemaking by April 30, 2016, 

We cannot predict at this time what form that final action 

will take. It could function as a step 4, bringing in 

additional sources based on, for example, streamlining actions, 

increased permitting authority resources, and experienced and 

more efficient permitting staff; and it could further indicate 

that we intend to follow-up with a step 5 to bring in more 

sources. Alternatively, it could also function as a final step 

excluding certain sources permanently based on our application 
59

of the Chevron framework, taking account of the “absurd results” 

doctrine, and subjecting the remaining sources to permitting. 

However, whatever final action we take would explain any 

necessary changes to the step 3 thresholds and would supersede 

the 6-year exclusion for sources and modifications below 50,000 

tpy CO2e. 

C. How do state, local and tribal area programs adopt the final 

GHG applicability thresholds?

We are finalizing our proposed approach to change the 

definition of “major stationary source” in the PSD implementing 

regulations, and the “major source” definition in the title V 

implementing regulations to tailor the application of these 

permitting programs to GHG emissions. We also finalize a 

significance level for GHG emissions for purposes of defining a 

major modification under the PSD program, and add an exclusion 

from PSD and title V permitting for GHG emissions, until we 

complete a rulemaking required by April 30, 2016, for any 

sources that are not already subject to PSD and title V 

permitting and that emit less than 50,000 tpy of CO2e. 

 As explained earlier, we are adopting thresholds that phase 

in the applicability of GHG permitting over a specified time 

period. In adopting regulatory changes to implement these 

thresholds, we follow an approach that is substantively the same 
60

as the approach proposed, but takes a different form. 

Specifically, we are explicitly codifying the phrase “subject to 

regulation” in our implementing regulations, instead of revising 

the “major stationary source” and “major source” definitions by 

incorporating the Tailoring Rules numerical thresholds directly 

into the definitions. Under this mechanism, we interpret the 

term “subject to regulation” so that GHG emissions from sources 

above the threshold are treated as subject to regulation, and 

therefore the sources that emit them are subject to PSD and 

title V; while GHG emissions from sources below the threshold 

are not treated as subject to regulation, and therefore the 

sources that emit them are not subject to PSD or title V. We 

are finalizing this alternative regulatory approach to 

facilitate rapid adoption and implementation of the final rules 

by states. These states would be able to establish their 

interpretation of “subject to regulation” by January 2, 2011, 

which is the date that the Tailoring Rule would take effect, and 

thereby, at that time, exempt sources below the threshold from 

PSD and title V as a matter of both federal and state law. We 

are also finalizing this definition consistent with our 

statements in our recent action “Reconsideration of 

Interpretation of Regulations that Determine Pollutants Covered 

by Clean Air Act Permitting Programs” (75 FR 17704) to better 
61

inform readers of our existing interpretation of this phrase as 

it applies to all air pollutants. States may not need to 

undertake a regulatory or legislative action before implementing 

the final rule. 

Because we finalize the rule in a manner that will allow 

most states to rapidly adopt and implement the final rule, and 

because our recent action on the Interpretive Memo allowed for a 

longer transition time than we anticipated at proposal, we are 

delaying final action on our proposal to issue limited approvals 

for SIP-approved PSD programs and part 70 operating permit 

programs.11 Instead, we are requesting that states submit 

information to the appropriate Regional Administrator by [INSERT 

DATE 60 DAYS AFTER PUBLICATION IN THE FEDERAL REGISTER] so that 

we may determine whether it is still necessary to finalize any 

of our proposed limited approvals for any SIP-approved PSD and 

part 70 title V state programs. In that letter, states should 

explain whether they will adopt EPA’s regulatory interpretation 

of the term “subject to regulation” in implementing both their 

PSD and part 70 title V permitting programs, and if so, whether 

the state intends to adopt the interpretation without 

undertaking a regulatory or legislative process. If a state 

must revise its statutes or regulations to implement the 

 11 In the alternative, we also proposed to use our 110(k)(6) 

error correction authority to revise SIP-approved PSD programs. 
62

interpretation, we ask states to provide an estimate of the time 

to adopt final rules in its letter to the Regional 

Administrator. If a state chooses not to adopt our 

interpretation, the letter should address whether the state has 

alternative authority to implement the final rule’s tailoring 

approach or some other approach that is at least as stringent, 

but which also addresses the expected shortfalls in personnel 

and funding that would exist if the state carried out permitting 

at thresholds lower than those in the final rules. For any 

state that is unable or unwilling to adopt the permitting 

thresholds in the final rules, and otherwise is unable to 

demonstrate adequate personnel and funding, or alternate 

authority to permit GHG emissions sources consistent with the 

final rules, EPA will move forward with finalizing a limited 

approval of the state’s permitting program. By the same token, 

if we do not receive a letter from a state in response to this 

request by [date], we will be obliged to move forward with 

finalizing a narrowing of our approval of the existing SIP or 

title V program. 

We also ask any state that currently lacks authority to 

issue PSD or title V permits to any GHG emissions sources to 

notify the Regional Administrator by letter as to whether the 

state intends to undertake rulemaking to revise their rules 
63

consistent with these applicability thresholds. For any state 

that lacks the ability to issue PSD or title V permits for GHG 

emissions sources consistent with the final rule, we will 

undertake a separate action to call for revisions to these 

programs. We will also move quickly to impose a FIP for PSD 

through 40 CFR 52.21, and use our federal title V authority to 

ensure that GHG sources will be permitted consistent with the 

final rules. Our request for information from states is 

discussed further in section V.C. 

D. How do you treat GHGs for title V permit fees?

We are not amending the title V regulations for fees at 

this time, including any of the provisions specifying the 

presumptive minimum fee. We are also not, at this time, calling 

for each state, local or tribal program to submit new fee 

adequacy demonstrations as a result of increased GHG permitting 

workload during steps 1 and 2. However, as described in section 

VI.D the statutory and regulatory requirement to collect fees 

sufficient to cover all reasonable (direct and indirect) costs 

required to develop and administer title V programs still 

applies. Therefore we are recommending that each program review 

its resource needs for GHG-emitting sources and determine if the 

existing fee approaches will be adequate. If those approaches 

will not be adequate, we suggest that state, local and tribal 
64

agencies should be proactive in raising fees to cover the direct 

and indirect costs of the program or develop other alternative 

approaches to meet the shortfall. We will closely monitor 

approved title V programs during the first two steps of the 

Tailoring Rule to ensure that the added workload from 

incorporating GHGs into the permit program does not result in 

fee shortfalls that imperil operating permit program 

implementation and enforcement. In developing alternative 

approaches, we note the value of approaches that do not require 

a per-ton fee for GHG and therefore do not require a GHG 

inventory to develop. Finally we offer to work with permitting 

authorities that request our assistance with developing fee 

approaches. 

E. Other Actions and Issues 

This section describes other actions we intend to take in 

the future related to GHG permitting in addition to the actions 

that we are promulgating with this final rule. This section 

also responds to commenters’ suggestions that we undertake 

additional actions in this rule, which we decline to do. 

1. Timing for Permit Streamlining Techniques 

As described at proposal, we intend to develop a series of 

streamlining approaches as an integral part of our phase-in 

approach. The approaches we described at proposal included: 
65

(1) defining PTE for various source categories, (2) establishing 

emission limits for various source categories that constitute 

presumptive BACT, (3) establishing procedures for use of general 

permits and permits-by-rule, (4) establishing procedures for 

electronic permitting, and (5) applying lean techniques to 

establish more efficient permitting processes. Taken as a 

whole, these techniques have the potential to obviate the 

applicability of PSD and title V requirements for some GHGemitting sources; promote more efficient treatment of GHGemitting sources that will already be subject to PSD and title 

V; and allow the expeditious expansion of PSD and title V 

applicability to more GHG-emitting sources while protecting 

those sources and the permitting authorities from undue 

expenses. 

As a result, we fully intend to move forward expeditiously 

with developing streamlining approaches. However, for reasons 

discussed in section V.E, we do not expect to develop and 

implement any of these approaches before step 2 begins. 

Moreover, we generally expect that each of the first three – 

which are the most far-reaching -- will take several years to 

implement because we will need to undertake notice and comment 

rulemaking to develop them, and then the permitting authorities 

will need to adopt them through the appropriate state or local 
66

processes. We commit to explore a wide range of possible 

approaches before the step 3 rulemaking, and, in that 

rulemaking, to propose those that we think may be viable once we 

have had time to gather and review key supporting data, and once 

the states and we have key implementation experience that can 

inform our thinking. Because the streamlining approaches 

generally carry uncertainty - as demonstrated by comments we 

received raising legal and policy concerns, as discussed later, 

that we will have to address - we are not committing with this 

action to adopt streamlining actions on any particular schedule. 

However, we intend to pursue streamlining options as 

expeditiously as possible, beginning immediately and proceeding 

throughout the phase-in period, and we encourage permitting 

authorities to do the same. 

2. Guidance for Best Available Control Technology 

Determinations 

Through this final rule we are not amending our regulations 

or issuing guidance on BACT for GHGs. As described in our 

proposal, we recognize the need to develop and issue technical 

and policy guidance for permitting of GHGs, and we plan to 

accomplish it through a separate effort that will involve 

stakeholder input. This effort is already underway; in addition 

to comments EPA received on the proposed Tailoring Rule related 
67

to GHG BACT guidance and information needs, EPA received a suite 

of recommendations from the Clean Air Act Advisory Committee 

(CAAAC) to which EPA is actively responding. This includes 

technical guidance and database tools that EPA anticipates 

issuing by June 2010, and policy guidance that will be issued by 

the end of 2010. Thus, this important information will be 

available to support permitting agencies in their BACT 

determinations at the time that the GHGs become a regulated NSR 

pollutant, once the light-duty vehicle rule takes effect in 

January 2011. EPA is confident that these measures will help 

support a smooth transition to permitting emissions of GHGs. 

3. Requests for Higher Category-Specific Thresholds and 

Exemptions from Applicability 

 EPA has decided not to provide exemptions from 

applicability determinations (major source and major 

modification) under title V and PSD for certain GHG emission 

sources, emission activities, or types of emissions at this 

time. Commenters requested several applicability exemptions 

with respect to GHGs from, for example, agricultural sources, 

residential sources, small businesses, energy-intensive 

industrial processes (e.g., aluminum, steel, cement, glass, and 

pulp and paper manufacturers), lime production, semiconductor 

production, poultry production, solid waste landfills, biomass 
68

combustion/biogenic emissions, fugitive emissions, and pollution 

control projects. For reasons explained in section VI.E, we 

have decided to address the need for tailoring through a uniform 

threshold-based approach, rather than through a collection of 

various specific exclusions. 

4. Transitional Issues including Requests for Grandfathering 

For reasons explained in section V.E, EPA has determined 

that transitional issues for pending applications and permitted 

sources are adequately addressed by existing requirements and 

the amount of lead time provided before permitting requirements 

apply to GHGs under this rule and the April 2, 2010 final action 

regarding the Interpretive memo. This rule does not contain any 

additional exemptions or grandfathering provisions addressing 

the transition to PSD and title V permitting for GHGs. 

We are not promulgating an exemption for PSD permit 

applications that are pending when step 1 of the permitting 

phase-in begins for those sources that would otherwise need to 

obtain a PSD permit based on emissions of pollutants other than 

greenhouse gases. Any PSD permits issued to Phase 1 sources on 

or after January 2, 2010 will need to address GHGs. This action 

makes no change to the position we expressed on this issue on 

April 2, 2010. 
69

 Final PSD permits issued before January 2, 2011 need not be 

reopened or amended to incorporate requirements for GHGs that 

take effect after the permit is issued. A source that is 

authorized to construct under a PSD permit but has not yet begun 

actual construction on January 2, 2011 may begin actual 

construction after that date without having to amend the 

previously-issued PSD permit to incorporate GHG requirements, 

provided the permit has not expired. 

Sources that are not subject to PSD permitting requirements 

until Step 2 need not obtain a PSD permit addressing GHGs in 

order to continue any actual construction that begins before 

July 1, 2011, when such a source was not a major stationary 

source required to obtain a PSD permit. However, Phase 2 

sources that begin actual construction in phase 2 may do so only 

after obtaining a PSD permit. 

The title V permitting regulations already include a robust 

set of provisions to address the incorporation of new applicable 

requirements and other transitional considerations. A title V 

source applying for the first time must submit its permit 

application within 12 months after the source becomes subject to 

the operating permit program or an earlier time at the 

discretion of the permitting authority. Where a source is 

required to obtain a PSD permit, the source must apply for a 
70

title V permit or permit revision within 12 months of commencing 

operation or on or before such earlier date as the permitting 

authority may establish. Where additional applicable 

requirements become applicable to a source after it submits its 

permit application, but prior to release of a draft permit, the 

source is obligated to supplement its application. Permitting 

authorities may also ask for additional information during the 

processing of an application. In addition, where a source that 

already has a title V permit becomes subject to additional 

applicable requirements, the permitting authority is required to 

reopen the permit to add those applicable requirements if the 

permit term has 3 or more years remaining and the applicable 

requirements will be in effect prior to the date the permit is 

due to expire. 

V. What is the legal and policy rationale for the final 

actions? 

In this section, we describe the legal and policy rationale 

for our action, including our rationale for the following: (A) 

our approach to calculating GHG emissions for PSD and title V 

applicability purposes, (B) our approach to establishing the 

thresholds and timing of PSD and title V applicability to GHG 

emissions sources; (C) how state, local, and tribal area 

programs adopt the final GHG applicability thresholds; (D) 
71

treatment of GHGs for title V permit fees; (E) future 

activities, including streamlining actions. We present the 

rationale description in five subsections later, corresponding 

to the basic presentation of the approach in section IV. 

A. Rationale for Our Approach to Calculating GHG Emissions for 

PSD and Title V Applicability Purposes

1. Grouping of GHGs into a Single Pollutant 

 In this section, we explain our treatment of the air 

pollutant at issue for purposes of PSD and title V, such that 

sources that emit that pollutant in the requisite quantities 

become subject to PSD and/or title V requirements. We explain 

our rationale for treating the GHG air pollutant as a combined 

group of six greenhouse gases instead of six separate air 

pollutants defined by each individual greenhouse gas, and our 

rationale for including all six of the GHGs in that group. We 

also define the GHG metric to use for comparison to the 

applicability thresholds. 

 We proposed to identify the air pollutant as the aggregate 

group of the six GHGs that comprise the GHG pollutant, and to 

use a GHG metric for the applicability thresholds based on CO2e. 

The summed CO2e emissions would then be compared to the 

applicable permitting threshold to determine whether the source 

is subject to PSD and title V requirements. Historically, the 
72

PSD and title V regulatory provisions do not, in the first 

instance, define the “air pollutant” to which they apply, but 

rather rely for the definition of the pollutant on a crossreference to the regulatory provision under another part of the 

Act that establishes the emission standards or limits for that 

pollutant that in turn causes the pollutant to be subject to 

regulation under PSD and title V permitting. As an example, the 

pollutant ‘total reduced sulfur’ is a pollutant comprised of the 

sum of multiple compounds that was originally defined under the 

NSPS, Subpart BB, Standards of Performance for Kraft Pulp Mills, 

which then caused it to be subject to regulation under the PSD 

program. The actual compounds that define the pollutant TRS are 

identified in the NSPS. The PSD program regulations did not 

introduce its own independent definition of TRS, but instead 

relied on the definition as contained in the Kraft Pulp Mills 

NSPS. 

However, at the time of our proposal, the endangerment and 

cause or contribute findings had not been completed and the LDVR 

for GHGs had not been finalized. Thus, there was no final 

agency action defining the “air pollutant” consisting of GHGs to 

be considered “subject to regulation”. Absent a definition of 

“greenhouse gases” under another regulatory provision that we 

could cross-reference, we proposed to define “greenhouse gases” 
73

for permitting purposes as “the single air pollutant that is 

comprised of the group of six GHGs, as proposed in the [CAA] 

section 202(a) endangerment and contribution findings.” 74 FR

55,329, col. 1. The six well-mixed GHGs identified in the 

proposed contribution finding were: CO2, CH4, N2O, SF6, HFCs, and 

PFCs. 

 In the proposal, we further recognized that the LDVR for 

GHGs, as it was proposed, would result in reductions of only 

four of the gases, not all six, because only four are emitted by 

vehicles. However, we concluded that if the LDVR were finalized 

as proposed, then the air pollutant for purposes of PSD and 

title V applicability would be a single air pollutant that is 

the aggregate mix of the group of six GHGs because – 

[t]hese six GHGs as a class comprise the air pollutant 

that is the subject of the endangerment finding and 

companion contribution finding and constitute the air 

pollutant that is regulated by the light-duty vehicle 

rule through measures that address the components of 

that air pollutant that are emitted from the mobile 

sources. Thus, although the CAA section 202(a) 

proposal establishes controls only with respect to 

four GHGs, as a legal matter, the proposal covers the 

entire set of GHGs that as a class are the single “air 

pollutant” in the proposed endangerment and 

contribution findings. 

74 FR 55,329 col. 1. 

 We also solicited comment on whether we should identify 

the GHG metric in a different way, such as addressing each GHG 

constituent compound individually or including (whether 
74

individually or as a group) only those four GHG constituent 

compounds for which reductions would occur through the emission 

standards or limits proposed in the LDVR. 

A minority of the comments on our proposal addressed this 

issue. Some commenters supported combining the individual GHGs 

as one pollutant for purposes of determining permitting 

applicability, and stated that it is not uncommon for EPA to 

recognize ‘collective’ air pollutants comprised of many 

individual compounds based upon shared threats to health and 

welfare, including such EPA-created group pollutants as sulfur 

oxides, nitrogen oxides, volatile organic compounds (VOCs), and 

particulate matter (PM). 

On the other hand, a significant number of commenters also 

raised concerns that grouping the individual GHGs into one 

metric. Some of these commenters argued that grouping GHGs is 

not appropriate because GHGs are not like other air pollutants 

that are comprised of numerous substances of concern (e.g., VOCs 

and PM), individual GHGs do not interact or combine to create a 

pollutant of concern, and EPA has not established a ‘GHG’ NAAQS 

that supports the definition of the pollutant as a group. Some 

were concerned that regulating the GHGs as a group would 

increase the likelihood that a source will trigger permitting 

requirements, adding that this is unnecessary and would conflict 
75

with the “absurd results” and “administrative necessity” 

doctrines because it would lead to larger numbers of sources 

becoming subject to permitting. Some commenters opposing 

grouping suggested that we should explore regulating each of the 

GHG pollutants on an individual mass basis rather than 

collectively because in their view, it is reasonable and 

feasible to regulate and control emissions of each of the listed 

pollutants, other than carbon dioxide, at the 100/250 tpy 

thresholds, or less if deemed necessary, in accordance with the 

established mechanisms of the Act and doing so would lead to a 

better environmental result. Finally, some commenters argued 

that disaggregating the pollutants would also allow for more 

appropriate technology review. 

 After considering these comments, and taking into account 

other related actions that have occurred since proposal, we have 

determined that PSD and title V permitting program requirements 

will apply, as proposed, to the “single air pollutant that is 

comprised of the group of six GHGs.” 74 FR 55,329, col. 1. We 

believe that this approach is both compelled by the statute and 

reflects the preferable policy approach. 

As more fully discussed elsewhere in this rulemaking, the 

PSD requirements apply to a “major emitting facility” that 

undertakes construction or “modification.” CAA section 165(a), 
76

169 (2)(C). The term “major emitting facility” is defined as, 

in general, a source that emits 100 or 250 tons of “any air 

pollutant,” CAA section 169(1), and, similarly, the term 

“modification” is defined as a physical or operational change 

that results in the increased or new emissions of “any air 

pollutant.” CAA section 169(2)(C), 111(a)(4) Through 

regulation, we have interpreted the term “any air pollutant,” as 

found in both the terms “major emitting facility” and 

“modification,” more narrowly to mean any “regulated NSR 

pollutant,” and we further define this term to include any 

pollutant that is “subject to regulation under the Act.” 40 CFR 

52.21(b)(50)(iv), 52.21.(b)(2).12 

Similarly, as discussed elsewhere, the title V requirements 

apply to a “major source,” which is defined, in general, as any 

source that emits at least 100 tpy of “any air pollutant.” CAA 

§§ 502(a), 501(2)(B), 302(j). EPA has interpreted the term “any 

air pollutant” narrowly so that applies only with respect to air 

pollutants that are subject to regulation under the CAA. 

Memorandum from Lydia N. Wegman, Deputy Director, Office of Air 

Quality Planning and Standards, U.S. EPA, “Definition of 

 12 By the same token, CAA section 165(a)(4) requires that a 

source subject to PSD impose best available control technology 

for “each pollutant subject to regulation under this chapter” 

that the source emits. 
77

Regulated Air Pollutant for Purposes of Title V” (Apr. 26, 

1993). 

Based on these provisions, the key issue for present 

purposes in determining whether a source is subject to PSD 

(because it qualifies as a major emitting facility that 

undertakes construction or modification) or title V is whether 

the pollutant or pollutants that the source emits comprise the 

“air pollutant” that is “subject to regulation” under the Act. 

The phrase “subject to regulation under the Act” by its 

terms, identifies the air pollutant that is subject to PSD and 

title V as the same air pollutant that is identified in the 

regulatory action under another provision of the Act. The term 

is a simple cross-reference. It carries no implication that EPA 

may, in identifying the pollutant to which PSD or title V apply, 

may redefine the pollutant that is regulated elsewhere in the 

Act. Whatever the pollutant is that is regulated elsewhere, it 

is that pollutant to which PSD and title V apply. 

Since the time of our proposal, we have finalized both the 

contribution finding and the LDVR for GHGs. The final LDVR for 

GHGs specifies, in the rule’s applicability provisions, the air 

pollutant subject to control as the aggregate group of the six 
78

GHGs, including CO2, CH4, N2O, SF6, HFCs, and PFCs.13 Because it 

is this pollutant that is regulated under the LDVR, it is this 

pollutant to which PSD and title V apply. Specifically, the 

applicability provision in the LDVR provides a clear reference 

to the definition of the single pollutant comprised of the 

aggregate group of the six well-mixed GHGs, which makes clear 

PSD and title V applicability depends on he same sum-of-six GHG 

construct. We must follow this construct of the aggregate group 

of the six gases and do not have discretion to interpret the GHG 

‘air pollutant’ differently for the purposes of PSD or title V. 

This construct of the pollutant as the aggregate group of 

the six gases is also consistent with the definition of the air 

pollutant in the final contribution finding for GHGs [see 74 FR 

66496, 66499, 66536-7 (December 15, 2009)]. There, the 

Administrator defined the air pollutant as the “aggregate group 

of the same six... greenhouse gases,” 74 FR 66536), and these the 

well-mixed greenhouse gases are defined to include CO2, CH4, N2O, 

SF6, HFCs, and PFCs. 

 13 The applicability provision of the LDVR is found in 40 CFR 

§86.1818-12(a), which provides as follows: 

Greenhouse gas emission standards for light-duty vehicles, 

light-duty trucks, and medium-duty passenger vehicles. 

Applicability. This section contains standards and other 

regulations applicable to the emission of the air pollutant 

defined as the aggregate group of six greenhouse gases: 

carbon dioxide, nitrous oxide, methane, hydrofluorocarbons, 

perfluorocarbons, and sulfur hexafluoride.. 
79

Moreover, even if we had discretion to identify the GHGs 

air pollutant differently in the permitting programs than in the 

LDVR, we believe it is reasonable to identify the GHGs air 

pollutant through the sum-of-six construct for the same reasons 

why we adopted that definition in the contribution finding and 

for additional reasons noted below specific to the permit 

programs. The term “air pollutant” is defined under CAA section 

302(g) as “any air pollution agent or combination of such 

agents, including any physical, chemical, biological, 

radioactive ... substance or matter which is emitted into or 

otherwise enters the ambient air.” Under this definition, EPA 

has broad discretion to identify an air pollutant, including, as 

appropriate, treating a combination of air pollutant agents as a 

single air pollutant. Here, we think that the six well-mixed 

gases are appropriately combined into a single air pollutant 

because, as noted in the contribution findings, they share 

several important attributes: Each of the six gases -- 

• Is directly emitted (and is not formed by secondary 

processes in the atmosphere) 

• Is long-lived in the atmosphere after it is emitted 

• Is sufficiently long-lived the greenhouse gas that it 

becomes “well-mixed,” which means that its concentration is 
80

essentially uniform in the atmosphere (as opposed to having 

significant local/regional variation); and 

• Has well understood atmospheric properties (e.g., 

radioactive forcing). 

See 74 FR 66516-66518. 

In addition, treating the six greenhouse gases as a single 

air pollutant is consistent with the actions of international 

scientific bodies. For example, the Intergovernmental Panel on 

Climate Change (IPCC) considers in various reports how the six 

gases drive human-induced climate change and how that affects 

health, society, and the environment. Similarly, the United 

Nations Framework Convention on Climate Change (UNFCCC) requires 

reporting of these six gases and the commitments under the 

UNFCCC and Kyoto Protocol are based on the combined emissions of 

these six gases. Finally, as discussed later, it is standard 

practice to compute the “carbon dioxide (CO2) equivalency” of 

aggregate emissions using GWP. 

We disagree with commenters who argued that grouping all 

six GHGs is not appropriate because GHGs are not like other air 

pollutants that are comprised of numerous substances of concern 

(e.g., VOCs and PM). First, as noted previously, we are 

following the approach to a single air pollutant comprised of 

the aggregate of the six greenhouse gases initially adopted in 
81

the contribution finding and followed in the LDVR. Many of 

these same comments have already been addressed in the 

contribution finding and response to comments document, which is 

included in the Response to Comments (RTC) for this action, and 

those responses apply equally here. 

In addition to the reasons described in the endangerment 

and contribution findings, there are CAA permitting programmatic 

and policy advantages to using the sum-of-six construct for the 

GHG air pollutant for PSD and title V applicability purposes. 

We believe now, as we did at proposal, that the benefits in 

using the cumulative group of GHGs outweigh any implementation 

advantages to using an individual-GHG-based metric. The 

advantages to sum-of-six definition include that it may -- (1) 

allow significantly more flexibility to sources for designing 

and implementing control strategies that maximize reductions 

across multiple GHGs and would also likely align better with 

possible future regulations that allow for such flexibility; (2) 

more effectively support possible future offsets or trading 

mechanisms that involve different source categories and 

different compositions of GHG emissions; and (3) could better 

accommodate and harmonize with future regulations because it 

establishes one class of pollutants that includes individual 
82

components that may, in turn, become subject to specific 

emission standards under future regulatory efforts. 

We disagree with commenters who believe that aggregating 

the GHGs under one GHG metric for permitting applicability 

purposes would lead to an excessive amount of source permitting 

activity. This is because the phase-in approach addresses 

overwhelming permitting burdens associated with permitting of 

greenhouse gases. It does so by designing our applicability 

thresholds to allow for a manageable amount of new permitting 

actions based on the emissions from sources using the sum-of-six 

metric. If we based applicability on individual gases, 

(assuming, again, that we have authority to deviate from the 

definition of “air pollutant” as used in the LDVR), we would 

still need to determine what level of permitting is manageable 

and appropriate based on thresholds on an individual gas basis 

and would expect that the final rule would result in the same 

levels of remaining burden. Accordingly, unless the permitting 

program were being implemented at the statutory thresholds, the 

effect of a decision to aggregate or not aggregate would not 

reduce workload; it would simply shift work from permitting 

facilities that trigger based on combined GHGs to those that 

trigger based on individual GHGs. Although we acknowledge that 

this may affect applicability for a particular source, we 
83

disagree with the commenter that doing so would conflict with 

our conclusions based on the “absurd results” or “administrative 

necessity” doctrines. By using a consolidated and weighted 

measurement, we are able to direct the limited administrative 

resources to those new sources and modifications with the 

greatest impact on GHG emissions. 

We also believe that the additional flexibility resulting 

from the sum-of-six GHG metric will provide substantially more 

opportunities for sources to address emission increases of GHGs 

than they would have had under an individual gas based metric, 

and thereby possibly reduce their permitting burden through 

multi-gas mitigation strategies. We disagree with the comment 

that isolating BACT review on sources that emit a single GHG 

necessarily leads to better environmental results than it would 

for sources that undergo a combined review for all six gases. 

To the contrary, given that Congress built in considerations of 

energy, environmental, and economic impacts into the BACT 

requirement, we think that allowing consideration of those 

factors across six gases will likely result in decisions that 

more appropriately account for those impacts at the source. 

2. Identifying Which GHGs are Included in the Group 

As discussed previously, we proposed to include the 

combination of six well-mixed GHGs as the air pollutant that 
84

triggers PSD and title V applicability: CO2, CH4, N2O, SF6, HFCs, 

and PFCs. Some commenters supported including all six. They 

cite the proposed contribution findings that identify the 

pollutant through the sum-of-six construct, and they emphasize 

that EPA, in order to protect the public, has to control all the 

greenhouse gases it has regulated and reduce the overall impact 

of the mix of six greenhouse gases. 

However, a substantial number of commenters, mainly from 

industry sectors who also disagree with grouping the GHGs 

together, contend that only the constituent gases that are 

actually subject to controls under the LDVR should be included 

in determining applicability under the Tailoring Rule. Some of 

these commenters believe that only the three compounds (CO2, CH4, 

N2O) for which the LDVR contains emissions standards or caps 

should be considered in the GHG metric for permitting, while 

others would also add HFCs (which are included in a credit 

flexibility arrangement under the LDVR) for a total of four 

GHGs. These commenters argued that PSD is not triggered for all 

six GHGs by the LDVR because under the proposed PSD 

interpretation in “EPA’s Interpretation of Regulations that 

Determine Pollutants Covered by Federal Prevention of 

Significant Deterioration (PSD) Permit Program”, actual emission 

controls under the Act are required to trigger PSD obligations 
85

for a given pollutant. They also argue that including all six 

would conflict with EPA’s rationale for the tailoring rule by 

leading to larger numbers of sources subject to permitting, 

thereby increasing the harm that EPA says it wants to avoid. 

They further assert that the EPA cannot exercise its discretion 

to widen the scope of PSD and title V applicability to six GHGs 

when it is relying on the judicial doctrines of “absurd results” 

and “administrative necessity” to narrow PSD and title V 

applicability. They explain that in their view, those doctrines 

apply only when EPA has taken all steps possible to narrow the 

scope of PSD and title V and thereby avoid the administrative 

problems that force it to rely on those doctrines. 

There were a few comments on whether to include specific 

gases as part of the sum-of-six grouping. Several commenters 

representing sectors that have significant SF6 usage specifically 

argue that SF6 should not be included as a GHG, at least at this 

time, because there are no known SF6 controls, it is not clear 

how PTE would be calculated from such facilities, and EPA has 

not addressed the economic burden that regulation of these 

facilities would create. A solid waste industry commenter 

asserts that the Tailoring Rule should confirm that CH4 and N2O 

will not be regulated under PSD or title V because these 

pollutants are only emitted in miniscule amounts from 
86

automobiles. 

 We disagree with commenters who suggest that because the 

LDVR actually regulates only four of the six GHGs, EPA may apply 

PSD and title V to only those four GHGs. It is true that the 

LDVR standard for the single air pollutant that is comprised of 

the aggregate of six GHGs consists of individual standards for 

only four particular constituents of the single air pollutant – 

which are emissions limits or caps for three GHGs (CO2, CH4, and 

N2O) and an emission crediting option for one GHG (HFCs) – but 

this does not dictate that only those four compounds are subject 

to regulation for permitting purposes. Although the LDVR 

results in reductions only with respect to four specific GHGs, 

as a legal matter the LDVR standard covers the entire set of 

GHGs that as a class are the single “air pollutant” in the 

contribution finding. Similar to our rationale for addressing 

the group of six GHGs as one pollutant for PSD and title V 

applicability purposes, we must adhere to the definition of 

applicability, cited previously, in the final LDVR for GHGs and 

include CO2, CH4, N2O, SF6, HFCs, and PFCs. We do not have 

discretion to select only a subset of these gases in defining 

our GHG threshold metric for the permitting applicability 

purposes. See LDVR, April 1, 2010 Preamble, II.A.2.c., pp 153-4 

(discussing EPA’s exercise of discretion under section 202(a) in 
87

setting emissions standards applicable to emission of the single 

air pollutant). [April 1, 2010 Preamble, II.A.2.c, pp 153-4.] 

For the same reasons, we disagree that this approach is 

inconsistent with the Agency’s final action in “EPA’s 

Interpretation of Regulations that Determine Pollutants Covered 

by Federal Prevention of Significant Deterioration (PSD) Permit 

Program.” While it is the case, that only four constituent 

gases are reduced by the LDVR, the ‘air pollutant” that is 

controlled, and thus “subject to regulation,” is the group of 

six, and it is this “air pollutant” to which PSD and title V 

apply. 

We also disagree with commenters who suggested that 

including all six GHGs in determining permitting applicability 

would conflict with our “absurd results” and “administrative 

necessity” rationale for the phase-in periods and applicability 

thresholds for GHGs. Even if we did have discretion to identify 

the air pollutant for PSD and title V purposes as consisting of 

only four of the six well-mixed GHGs, we do not believe that 

doing so would have any meaningful impact on the administrative 

burdens that are at the heart of our reliance on the “absurb 

results” and “administrative necessity” doctrines. The number 

of additional permitting actions and amount of additional 

permitting burden resulting from including all six GHGs, rather 
88

than four, in the definition is minimal. This is because the 

administrative burden of GHG permitting is dominated by CO2 and 

CH4 emission sources. For example, with a major source threshold 

set at 100,000 tpy CO2e, the combined population of sources that 

would be major for N2O, HFCs, PFCs, and SF6 accounts for fewer 

than two percent of the GHG sources that would remain covered. 

For similar reasons, we disagree with commenters who 

specifically suggest SF6 emissions should not be included in the 

applicability metric for GHGs. As we have stated earlier in 

this section, our selection of the GHG metric is driven by the 

definition of the “air pollutant” as defined in the LDVR, and in 

consideration of the final GHG endangerment finding. SF6 is 

specifically included as one of the “well-mixed greenhouse 

gases” in the definition of air pollutant in the contribution 

finding, and is included in the definition of the air pollutant 

in the LDVR for which that rule is applicable. We do not 

believe we have the discretion to define the “air pollutant” 

differently for PSD and title V applicability purposes than the 

definition of the “air pollutant” that is regulated elsewhere. 

In any event, including SF6 emissions based on the thresholds 

finalized in this rulemaking does not add an excessive 

administrative burden for permitting authorities. Based on our 

threshold evaluation study, we estimate that less than 40 
89

sources of SF6 nationwide would exceed the 100,000 tpy CO2e 

threshold. Furthermore, SF6 is a high GWP gas and, as discussed 

elsewhere, we have included a mass-based trigger for high GWP 

gases that will likely have the effect of further reducing this 

count. 

For the same reasons, we disagree with the commenters who 

suggest we include black carbon and other short-lived climate 

forcers to the list of GHGs, and well as commenters asking for 

an exclusion of CH4 and N2O. The definition of the air 

pollutant, as cited in the LDVR, includes CH4 and N2O and does 

not include black carbon or other short-lived gases. 

3. Use of GWP vs. mass-based GHG thresholds 

For the reasons discussed previously, we are determining 

permit program applicability based on the sum-of-six well-mixed 

gases that comprise the GHG air pollutant. This section 

discusses our use of both the CO2e metric and mass emissions of 

the GHGs for applicability purposes. 

Under our proposal, a source’s emissions of all six GHGs 

would be combined into a single metric by multiplying the mass 

of each individual GHG (in tpy) by its GWP value, and summing 

these products to determine the total emissions of the GHG 

pollutant in tpy CO2e. We received comments on this aspect of 

the proposed metric. Several commenters explicitly support the 
90

use of GWP and the CO2e metric for GHG emissions. These 

commenters believe EPA has the authority to select an 

appropriate metric to measure GHGs in the PSD program, and 

policy considerations support the choice of GWP. Some of them 

note that GWP is a widely-used metric which employs 

internationally-recognized conversion factors to compare GHGs 

based upon their climate properties, and some add that states 

and local areas that have climate action plans for GHG 

reductions use CO2e. Some of these commenters believe this 

metric will ensure a standard measure across all permitting 

agencies and will lead to a more effective system for permitting 

authorities and create more opportunities to reduce emissions 

over the full class of GHGs, rather than focusing on reducing 

individual GHGs. 

On the other hand, some commenters oppose the use of GWP 

and CO2e, believing that thresholds should be based on individual 

mass-based emissions for each GHG. Some of these commenters 

felt that EPA has no discretion to ignore the metric for 

regulation established by Congress for PSD in section 169 of the 

Act. Some commenters were also concerned that the use of CO2e 

will complicate the implementation of BACT because sources that 

trigger PSD will be required to install BACT for each regulated 

pollutant, not for CO2e. As a result, a source that exceeds the 
91

threshold primarily due to its CO2 emissions would be forced to 

install BACT for all other individual GHGs, regardless of how 

minor those other emissions may be. Finally, a commenter was 

concerned that use of GWP would complicate implementation 

because GWP values can sometimes change. 

In our proposal preamble discussion of GHG metric, EPA also 

raised the possibility of including a limitation in the metric 

to address the prospect (expected to occur only rarely) that 

high-GWP gases could be emitted in quantities less than 

statutory thresholds for PSD and title V but nevertheless exceed 

the proposed thresholds in terms of CO2e. Most commenters on 

this subject support a dual threshold under which a source would 

be subject to title V or PSD only if its GHG emissions exceeded 

both the statutory thresholds on an actual tonnage basis and the 

tailored thresholds on a CO2e basis. Commenters supporting this 

approach felt that it would be unlawful to apply PSD when GHGs 

are below the statutory thresholds, or when there is not a net 

emissions increase. Others added that the complexity of 

accounting for emissions according to both mass and GWP should 

be manageable and is not a reason to ignore the role of mass–

based emission rates in determining the applicability of PSD 

requirements. Additionally, one commenter observed that a dual 

threshold is consistent with phasing in the tailoring rule and 
92

is an effective way to address the current uncertainty 

surrounding how to measure high-GWP gases such as SF6. In 

contrast, a few commenters stated they do not support a dual 

threshold, primarily on the grounds that there is no benefit to 

the added complexity. 

After considering these comments, we have decided to adopt 

applicability thresholds based on a CO2e metric for the sum-ofsix well-mixed gases, and also to adopt an additional mass-based 

threshold for the sum-of-six gases as discussed in the proposal. 

First, as discussed in the previous section, we have explained 

why the appropriate pollutant for PSD purposes is the single 

pollutant GHG, which is composed of the six well-mixed gasses. 

Regarding the CO2e metric, we continue to believe there are a 

number of advantages, as laid out in the proposal, to a CO2e 

measure that would not be available if we used only a mass-based 

metric. These include: (1) a CO2e metric, by incorporating the 

GWP values, best addresses the relevant environmental endpoint, 

which is radiative forcing of the GHGs emitted; (2) when 

combined with a sum-of-six gases approach, the CO2e metric best 

allows for consideration of their combined effects when sources 

emit any one or combination of the six well-mixed GHGs; (3) a 

cumulative CO2e metric is consistent with the metric used in the 

mandatory reporting rule and other related rules and guidelines; 
93

and (4) a CO2e metric allows more flexibility for designing and 

implementing control strategies that maximize reductions across 

multiple GHGs. We recognize the tension between the mass-based 

metric in the statute and the CO2e-based metric we are adopting 

in this rule, but as discussed later, we will address this by 

also retaining the mass-based metric. Moreover, given our need 

to tailor our approach to covering sources of GHGs, we believe 

that the considerations driving our choice to also use a CO2ebased metric are appropriate for defining the phase-in and allow 

for permitting resources to be directed at those sources and 

modifications that have the greatest impact on radiative forcing 

of the GHGs emitted. 

We recognize the concern of commenters who stated that we 

cannot ignore the statutory thresholds based on the mass-based 

emissions of an air pollutant as described under CAA section 

169(1). As we mentioned in the proposal, because both the PSD 

and title V statutory thresholds are expressed on a mass basis—

i.e., tons of a pollutant with no weighting values applied—we 

were concerned from a legal standpoint that the metric proposed 

(CO2e) could have the effect of subjecting to PSD or title V 

requirements a source whose emissions fall below the statutory 

threshold limits on a strictly mass basis, but whose CO2e-based 

emissions exceed the CO2e thresholds we establish under the 
94

tailoring rule. As an example, in rare instances it is possible 

that a source may emit only a non-CO2 GHG in very small amounts, 

on a mass basis, but one that carries a very large GWP. In this 

case, it is possible that the source may emit the GHG in amounts 

that fall below the PSD and/or title V statutory applicability 

threshold (100 or 250 tpy, as applicable) on a mass basis, but 

exceed the 100,000 CO2e PSD and title V applicability thresholds 

for step 2 in this action. Under these circumstances, without a 

mass-based threshold, the source would trigger PSD and title V 

for its CO2e emissions even though its GHG mass emissions would 

not, in fact, exceed the statutory triggers. 

Upon review of the comments pertaining to this issue and 

further analysis of the legal and programmatic implications, we 

are adopting a two-part applicability process, for both major 

source applicability determinations for GHGs under PSD and title 

V and for determining if a net increase has occurred in PSD 

applicability determinations for modifications. As explained in 

the RTC, we accomplish this two-step applicability approach by 

continuing to rely on the existing mass-based applicability 

provisions in the current regulations, and by including new 

regulatory provisions that add a definition of "subject to 

regulation" that in turn includes the phase-in thresholds. 

Similarly, for PSD modification reviews and associated netting 
95

analyses, the same two-step process must be used. Our summary 

in section IV.A described how we expect this provision to be 

implemented in practice. 

We acknowledge that the possibility of changing GWP values 

is a downside to the use of CO2e for the GHG metric, and we 

address this comment in the next section, where we discuss our 

plan to codify GWP values. By codifying GWP, any changes will 

be manageable, and, in our judgment, will not outweigh the 

benefits of a CO2e-based approach. We also acknowledge that a 

CO2e-based approach may appear to complicate the BACT review and 

implementation process. However, we disagree with the 

commenter’s ultimate conclusion that BACT will be required for 

each constituent gas rather than for the regulated pollutant, 

which is defined as the combination of the six well-mixed GHGs. 

To the contrary, we believe that, in combination with the sumof-six gases approach described above, the use of the CO2e metric 

will enable the implementation of flexible approaches to design 

and implement mitigation and control strategies that look across 

all six of the constituent gases comprising the air pollutant 

(e.g., flexibility to account for the benefits of certain 

methane control options, even though those options may increase 

CO2). Moreover, we believe that the CO2e metric is the best way 
96

to achieve this goal because it allows for tradeoffs among the 

constituent gases to be evaluated using a common currency. 

4. Determining What GWP Values are to be Used 

 At proposal, we proposed to link the calculation of CO2e for 

GHGs to GWP values in EPA’s “Inventory of U.S. Greenhouse Gas 

Emissions and Sinks” (GHG Inventory). See, e.g., proposed 40 

CFR 51.166(b)(58). Numerous commenters expressed concerns about 

this proposal on various grounds, including the following: 

• The EPA should follow the proper notice-and-comment 

procedures and the requirements of the Information Quality 

Act (IQA) for the relevant technical underpinnings of the 

proposal. The EPA relies upon the GWPs of the IPCC without 

providing the supporting data for review, and it is 

inappropriate to use this as a basis for this rule without 

first making all the raw data available for public 

inspection and comment. 

• The EPA cannot tie the definition of GWP to the GHG 

Inventory because it is a non-regulatory document that may 

be changed without notice-and-comment rulemaking. Before 

EPA uses a new GWP, that GWP must be subject to notice and 

comment to comply with the requirements of CAA section 307 

and the Administrative Procedure Act (APA). 

• An annual update of GWP would create a moving target for 
97

sources conducting applicability determinations and 

assessing compliance with minor NSR and PSD emission 

limits. The EPA needs to ensure that applicability and 

compliance with limits continue to be based on the GWP that 

existed when the determination was made or the limit was 

established. 

• The EPA should freeze the GWP at the current values by 

incorporating those values into the regulation. The EPA 

could still revise the “NSR” GWP, but would have to revise 

the regulation to do so. 

Commenters added that it is important to ensure that all 

permitting agencies are using the same calculations for the 

determination of CO2e for GHGs. 

We agree with commenters who suggested we should codify, 

either in the Tailoring Rule or through reference to codified 

values in another rulemaking, the GWP values to be used in 

permitting analyses. We agrees that this approach provides 

certainty as to which GWP values need to be used and permitting 

authorities and sources to plan appropriately for possible 

changes in the GWP values. As mentioned in the comments, 

recommended GWP values from IPCC can change over time. While 

this is infrequent – the last such changes were in 2007—when it 

occurs, there are generally significant lag times in universal 
98

adoption of new values because of inconsistencies that could be 

created in national inventories and emission reporting 

mechanisms. In a regulatory setting, such as in the permitting 

programs, this could potentially create significant 

implementation issues, such as when a GWP change occurs while a 

permit action is in progress.14 EPA also recognized similar 

potential implementation issues in developing its final 

mandatory reporting rule for GHGs, and codified in the 

regulatory text for that rule the GWP values to be used in 

reporting GHGs as part of that final rulemaking. 

For these reasons, we have decided to follow the approach 

in the mandatory reporting rule and require that for PSD and 

title V permitting requirements, wherever emissions calculations 

are performed, that permitting authorities and sources use GWP 

values that are codified in EPA rules. We will establish the 

GWP values for PSD and title V rules based on a cross-reference 

to the values that are codified in the EPA’s GHG mandatory 

reporting rule. 74 FR 56,395, Table A-1 to Subpart A of Part 98 

– Global Warming Potentials. Any changes to Table A-1 of the 

mandatory GHG reporting rule regulatory text must go through a 

 14 We note that our approach does not entirely avoid the 

possibility that a GWP change can occur while a permit is in 

progress although it will ensure advance notice of such a 

change. In the event that we plan to propose a change to GWP 

values, we will work with permitting authorities as necessary to 

provide guidance to sources on transitional issues. 
99

notice-and-comment regulatory process. In this manner, the 

values used for the permitting programs will reflect the latest 

values adopted for usage by EPA after a formal regulatory 

process and will be consistent with those values used in the 

EPA’s GHG mandatory reporting rule. Furthermore, the lead time 

for adopting changes to that rule will provide a transition time 

to address implementation concerns raised by commenters. 

5. Use of Short Tons vs. Metric Tons 

 We proposed that the GHG metric would be expressed in terms 

of English (or short) tons, rather than metric (or long) tons. 

A few commenters support using short tons for this purpose. 

Others prefer the use of metric tons, and most of the them note 

that the GHG Reporting Rule is based on metric tons and believe 

that the Tailoring Rule should be consistent with that rule. 

These commenters believe that using different units in the two 

rules would be confusing and could result in sources that are 

not subject to the GHG Reporting Rule becoming subject to PSD. 

Some of the commenters add that various “cap and trade” 

legislative proposals also quantify GHGs in metric tons. A few 

other commenters recommend that EPA harmonize the applicability 

thresholds established under the Tailoring Rule and the GHG 

Reporting Rule without expressing a preference for short or 

metric tons. 
100

 We are finalizing our proposal to use short tones because 

short tons are the standard unit of measure for both the PSD and 

title V permitting programs and the basis for the threshold 

evaluation to support this rulemaking. Calculation inputs for 

PSD are typically prepared in English units (e.g., lbs of fuel, 

MMBtu’s, etc.) which is the common convention for all PSD 

analyses and the units of the statutory thresholds under the 

Act. 

It is true that the GHG mandatory reporting rule uses 

metric tons, but this does not create an inconsistency between 

permitting programs and the reporting rule because the two rules 

already use different applicability approaches. Although we 

originally proposed 25,000 tpy as the major source level for 

permitting programs, which was similar to the threshold in the 

reporting rule, we decided to adopt substantially higher 

thresholds in the final rule. Furthermore, even if the numbers 

were similar, the thresholds used for the permitting programs 

are based on actual emissions, while the PSD and title V 

programs are based on potential to emit. Therefore, we are less 

persuaded by arguments for consistency, and believe it is more 

important for ease of permit program implementation to ensure 

that GHG emissions calculations for PSD and title V will build 

on the same set of input variables used to develop short-ton 
101

based estimates for non-GHG pollutants. Thus, the use of short 

tons should actually facilitate the development of the GHG 

emission estimate. It would likely be more confusing to require 

a multi-pollutant PSD applicability analysis to present 

emissions information using different units for different 

pollutants, as would be the case if we required metric tons for 

GHG but continue to use short tons for every other pollutant. 

Finally, we do not expect this choice to introduce additional 

complexity because the conversion between short tons and metric 

tons is a very simple calculation. Therefore, based on these 

considerations we are requiring that short tons be used as the 

basis for emission calculations used to meet PSD and title V 

permitting requirements. 

B. Rationale for Thresholds and Timing for PSD and Title V 

Applicability to GHG Emissions Sources

 In this subsection, we describe our legal and policy 

rationale for our determinations concerning PSD and title V 

applicability to GHG emissions sources. This subsection 

includes: (1) an overview of our rationale; (2) data concerning 

costs to sources and administrative burdens to permitting 

authorities; (3) a review of the Chevron legal framework and the 

“absurd results,” “administrative necessity,” and “one-step-ata-time” doctrines, as well as a review of how those doctrines 
102

fit into the Chevron framework; (4) an overview of the relevant 

PSD and title V requirements and their legislative history; (5) 

our application of the “absurd results” doctrine for tailoring 

the PSD requirements; (6) our application of the “absurd 

results” doctrine for tailoring the title V requirements; (7) 

our plans to issue further rulemaking that will address the 

“absurd results” basis for both PSD and title V requirements; 

(8) our rationale for the phase-in schedule for applying PSD and 

title V to GHG sources; (9) our application of the 

“administrative necessity” basis for tailoring the PSD and title 

V requirements; and (10) our application of the “one-step-at-atime” basis for tailoring the PSD and title V requirements. 

1. Overview 

Under the familiar Chevron two-step approach to 

construction of agency-administered statutes, the agency must 

first, at Chevron step 1, determine whether Congress's intent in 

a particular provision on a specific question is clear; and if 

so, then the agency must follow that intent. If the intent of 

the provision is not clear, then the agency may, under Chevron

step 2, fashion a reasonable interpretation of the provision. 

The best indicator of congressional intent is the literal 

meaning of the provision and generally, according to the 

caselaw, if the literal meaning addresses the specific question, 
103

then the agency must follow the literal meaning. 

However, the courts have developed three doctrines relevant 

here that authorize departure from a literal application of 

statutory provisions. The first is the “absurd results” 

doctrine, which authorizes such a departure if the literal 

application would produce a result that is inconsistent with 

congressional intent, and particularly if it would undermine 

congressional intent. The judicial doctrine of “administrative 

necessity” authorizes an agency to depart from statutory 

requirements if the agency can demonstrate that the statutory 

requirements, as written, are impossible to administer. The 

“one-step-at-a-time” doctrine authorizes an agency, under 

certain circumstances, to implement a statutory requirement 

through a phased approach. 

Each of the three doctrines fits into the Chevron framework 

for statutory construction because each of the three is designed 

to effectuate congressional intent. Moreover, each of the 

doctrines can, at least in some cases, generally point to 

similar conclusions. For example, under the “absurd results” 

doctrine, the agency may vary from the statutory requirements 

only to the extent necessary to adhere to congressional intent, 

if congressional intent is clearly expressed, or to reasonably 

interpret the statute, if congressional intent is not clearly 
104

expressed. In the case of the “administrative necessity” 

doctrine, the agency must first attempt to mitigate 

administrative problems through techniques consistent with the 

statutory requirements, and, if variance from the statutory 

requirements nevertheless is necessary to allow 

administrability, the variance must be limited as much as 

possible. Under the one-step-at-a-time doctrine, the agency is 

required to adhere to the statutory requirements, but through a 

step-by-step approach. 

To apply the statutory PSD and title V applicability 

thresholds literally to sources of GHG emissions would bring 

tens of thousands of small sources and modifications into the 

PSD program each year, and millions of small sources into the 

title V program. These extraordinary increases in the scope of 

the permitting programs, coupled with the resulting burdens on 

the small sources and on the permitting authorities, would be 

several hundred-fold more than what Congress contemplated in 

enacting the PSD and title V programs. Moreover, the great 

majority of additional sources brought into the PSD and title V 

programs would be small sources that Congress did not expect 

would need to undergo permitting. Further, the administrative 

strains would lead to multi-year backlogs in the issuance of PSD 

and title V permits, which would undermine the purposes of those 
105

programs. Sources of all types – whether they emit GHGs or not 

– would face long delays in receiving PSD permits, which 

Congress intended to allow construction or expansion. 

Similarly, sources would face long delays in receiving title V 

permits, which Congress intended to promote enforceability. For 

both programs, the addition of enormous numbers of additional 

sources would provide little benefit. In the case of PSD, the 

large number of small sources that would be subject to control 

constitute a relatively small part of the environmental problem. 

In the case of title V, a great many of the sources that would 

be newly subject to permit requirements would have “empty” 

permits, that is, permits that do not include any applicable 

requirements, and that therefore serve little purpose. For 

these reasons, the “absurd results” doctrine applies to avoid a 

literal application of the thresholds. By the same token, the 

impossibility of administering the permit programs brings into 

play the “administrative necessity” doctrine. This doctrine 

also justifies not applying the PSD or title V applicability 

threshold provisions literally to GHG sources. 

The situation presented here is exactly the kind that the 

“absurd results,” “administrative necessity,” and “one-step-ata-time” doctrines have been developed to address. Separately 

and interdependently, they authorize EPA to tailor the PSD and 
106

title V applicability provisions through a phased program as set 

forth in this rule, and to use the initial period of phase-in to 

develop streamlining measures that would facilitate applying PSD 

and title V on a broader scale without overburdening sources and 

permitting authorities. In this manner, the phased approach 

reconciles the language of the statutory provisions with the 

results of their application and with congressional intent. 

2. Data Concerning Costs to Sources and Administrative Burdens 

to Permitting Authorities 

 This final action concerning applicability of PSD and title 

V to GHG-emitting sources, including the decisions on timing for 

the selected permitting thresholds, is based on our assessments 

of both the costs to the regulated sources to comply with PSD 

and title V permitting requirements and the administrative 

burdens to the permitting authorities to process PSD and title V 

permit actions for GHG-emitting sources. This section provides 

a summary of our cost and administrative burden assessments of 

permitting that would be required in the absence of any 

tailoring as well as under various tailoring options. 

Our estimates of costs to the sources and administrative 

burdens to the permitting authorities from PSD and title V 

applicability for GHG emissions are based on labor and cost 

information from the existing Information Collection Requests 
107

(ICRs) for PSD and title V programs.15 We applied the same basic 

methodology used for the proposal, which incorporates 

information on numbers and types of affected sources and 

estimated permitting actions. We evaluate administrative 

burdens in terms of staffing needs, time for processing permits, 

and monetary costs, and we make some judgments about how those 

burdens would affect the permitting authorities’ ability to 

effectively manage and administer their programs with the 

addition of GHG emission sources. We present the administrative 

burden data for applying PSD and title V requirements at the 

literal statutory thresholds -- that is, the 100/250 tpy levels 

for PSD and the 100 tpy level for title V – as well as at other 

thresholds, which range from 25,000 tpy CO2e to 100,000 tpy CO2e. 

We have significantly revised upwards our assessments of costs 

to sources and administrative burdens since proposal, and we 

summarize later our reasons for doing so. We also present 

significant comments concerning administrative burdens, and our 

responses to those comments. 

 In the next section, concerning legal and policy rationale 

for our actions, we discuss how these data on costs to the 

sources and administrative burdens to the permitting authorities 

 15 Summary of Methodology and Data Used to Estimate Burden 

Relief and Evaluate Resource Requirements at Alternative 

Greenhouse Gas (GHG) Permitting Thresholds;” Prepared by EPA 

Staff; March 2010. 
108

informed our decisions that PSD and title V requirements should 

not, at present, be applied to GHG-emitting sources under the 

literal terms of the statutory thresholds as well as our 

decisions concerning what thresholds to apply for Steps 1 and 2 

of the applicability phase-in approach and the applicability 

floor of 50,000 tpy CO2e. 

a. Costs to Sources 

 As we did at proposal, we have estimated costs to the 

sources of complying with PSD and title V starting from the data 

in the ICR. We recognize that the sizes of the sources, as 

measured by their emissions, that would be swept into the PSD 

and title V programs would vary greatly, and that their 

permitting costs would vary as well. For example, their PSD 

permitting costs would depend on the amount and types of their 

emissions and their control requirements. Accordingly, we have 

determined average costs, as described later. 

For PSD, at proposal, we estimated that on average, an 

industrial source would incur costs of $84,500 to prepare the 

PSD application and receive the permit, and on average, a 

commercial or residential source would incur costs of 20 percent 

that amount, or $16,900. 74 FR at 55,337 col. 3 to 55,339 col. 

3. For this action, we retain the same burden estimates for an 

average industrial source. This type of source would need 866 
109

hours, which would cost $84,500, to prepare the application and 

the PSD permit. However, based on comments received, we have 

determined that a more accurate estimate for an average 

commercial or residential source is 70 percent of that amount of 

time that an industrial source would need, up from our proposal 

of 20 percent. Thus, an average commercial or residential 

source would need 606 hours, which would cost $59,000, to 

prepare the PSD application and receive the permit. We are 

increasing this time over what we proposed because we now 

recognize that virtually all commercial and residential will 

have no experience with the PSD permitting process, and 

therefore will face a significant learning curve that will 

entail more time to complete the application, develop control 

recommendations, and take the other required steps. We believe 

this learning period could extend from two to possibly 4 years 

or more from the date that the sources become subject to PSD 

requirements, depending on the type and actual number of new 

sources that come in for permitting. In addition, we expect 

that in many cases, draft PSD permits for GHGs will receive 

comments from various stakeholders, from citizens groups to 

equipment vendors, who will seek to participate in the permit 

process, and that all this could add to the hours that the 
110

permittee will need to invest in the process.16 The actual costs 

to sources to install BACT controls, while still uncertain at 

this point, would likely add additional costs across a variety 

of sources in a sector not traditionally subject to such 

permitting requirements. 

For title V, at proposal, we estimated that on average, an 

industrial source would incur costs of approximately $46,400 to 

prepare the title V application and receive the permit, and on 

average, a commercial or residential source would incur costs of 

10 percent that amount, or almost $5,000. 74 FR at 55,338 col. 

1 to 55,339 col. 3. For this action, we retain the same burden 

estimates for an average industrial source. This type of source 

would need 350 hours, which would cost $46,400, to prepare the 

application and the title V permit. However, we have determined 

that a more accurate estimate for an average commercial or 

residential source is 50 percent of that amount of time that an 

industrial source would need, up from our proposal of 10 

percent. Thus, an average commercial or residential source 

would need about 175 hours, which would cost $23,200, to prepare 

the title V application and receive the permit. This increase 

is due to the same reasons as with the PSD program just 

 16 Summary of Methodology and Data Used to Estimate Burden 

Relief and Evaluate Resource Requirements at Alternative 

Greenhouse Gas (GHG) Permitting Thresholds;” Prepared by EPA 

Staff; March 2010. 
111

discussed. We now recognize that virtually all commercial and 

residential sources will have no experience with the title V 

permitting process, and therefore will face a significant 

learning curve that will entail more time to, for the first 

time, assess their GHG emissions (because such sources are not 

covered by EPA’s mandatory reporting rule), complete the 

application, respond to permitting authority comments, meet 

other title V administrative requirements, and respond to 

interested stakeholders.17 

b. Administrative Burdens to Permitting Authorities 

(1) Estimated Permitting Authority Burden at Proposal 

As at proposal, we estimated the administrative burdens to 

the permitting authorities at the various threshold levels for 

PSD or title V applicability as follows. First, for a 

particular threshold level, we estimated the number of GHGemitting sources that would be subject to PSD requirements 

because they would undertake new construction or modification, 

and the number of existing sources that would be subject to 

title V requirements. Second, we estimated the average 

additional administrative burden and cost of each PSD permitting 

action and each title V permitting action for the GHG-emitting 

 17 “Summary of Methodology and Data Used to Estimate Burden 

Relief and Evaluate Resource Requirements at Alternative 

Greenhouse Gas (GHG) Permitting Thresholds;” Prepared by EPA 

Staff; March 2010. 
112

sources. Third, we multiplied those two estimates, and the 

product is the additional administrative burden at the 

particular threshold level. We employed the same methodology 

for this final rule, but, as discussed later, and described in 

more detail in our final burden analysis,18 we have updated 

several key assumptions since the proposal as a result of our 

consideration of comments received. 

First, we present the administrative burdens at the 

statutory levels for PSD and title V applicability. At 

proposal, for the PSD program, we estimated the administrative 

burdens that would result from applying PSD at the 100/250 tpy 

major emitting facility threshold levels in two ways, as 

described in this section. We stated that at present, 280 

sources are subject to PSD each year, both for new construction 

and modifications. This figure served as the baseline from 

which to calculate increases in administrative burdens due to 

permitting GHG-emitting sources. 

The first method that we used to calculate the 

administrative burdens to the permitting authorities was in 

terms of workload hours, which we then converted to monetary 

costs. To make the workload calculation, we first estimated the 

 18 “Summary of Methodology and Data Used to Estimate Burden 

Relief and Evaluate Resource Requirements at Alternative 

Greenhouse Gas (GHG) Permitting Thresholds;” Prepared by EPA 

Staff; March 2010. 
113

number of GHG-emitting sources that would become subject to PSD 

through new construction and modification. Based on our GHG 

threshold data analysis, we estimated that almost 41,000 new and 

modified sources per year would become subject to PSD review. 

We first calculated the number of new sources that would become 

subject to PSD. To do this, we estimated growth rates for the 

various sectors, and then applied those growth rates to the 

numbers of sources in those sectors. We then calculated the 

number of modifications. To do this, we first assumed that each 

year, two percent of sources that meet or exceed the threshold 

levels for PSD applicability due to their conventional 

pollutants undertake modifications. We then calculated the 

number of sources that would meet or exceed the threshold levels 

for PSD applicability due to their GHG emissions, and applied 

the same assumption that two percent of them would undertake 

modifications. In this manner, we estimated the number of 

modifications of GHG-emitting sources that would become subject 

to PSD. 

 We noted that currently, 280 PSD permits are issued each 

year, but that applying PSD to GHG-emitting sources at the 

100/250 tpy statutory threshold levels would cause an increase 

in permits of more than 140-fold. The reason for the 

extraordinary increase in PSD applicability lies simply in the 
114

fact that it takes a relatively large source to generate 

emissions of conventional pollutants in the amounts of 100/250 

tpy or more, but many sources combust fossil fuels for heat or 

electricity, and the combustion process for even small 

quantities of fossil fuel produces quantities of CO2 that are far 

in excess of the sources’ quantities of conventional pollutants 

and that, for even small sources, equals or exceeds the 100/250 

tpy levels. 

 Based on the 140-fold increase in permits, we then 

estimated the per-permit burden on permitting authorities. As 

we stated in the proposal: 

We estimated the number of workload hours and 

cost a permitting authority would expend on each new 

source and each modification. We based these 

estimates on the workload hours and cost for 

processing permits for new sources of non-GHG 

emissions, which we derived from labor and cost 

information from the existing [Information Collection 

Requests (“ICRs”)] for PSD programs. The ICRs show 

that permitting authorities expend 301 hours to permit 

a new or modified industrial source.... 

We then made assumptions for number of workload 

hours and costs for new sources of GHG emissions. We 

assumed that permitting new industrial GHG sources 

that emit in excess of the 250-tpy threshold would be 

of comparable complexity to permitting non-GHG 

emitting industrial sources that are subject to PSD. 

Thus, for these sources, we assumed that permitting 

authorities would expend the same number of workload 

hours and costs, on a per-permit basis, as they do for 

non-GHG emitting industrial sources. On the other 

hand, for commercial and residential GHG sources that 

emit GHGs above the 250-tpy threshold (and as a result 

would be subject to the requirements of the PSD 

permitting program at this threshold level), we 
115

assumed that the workload hours and cost for 

permitting these sources would be significantly less 

than—only 20 percent of—the hours and cost necessary 

to prepare and issue initial PSD permits or permit 

modifications for industrial GHG sources. This 20-

percent estimate amounts to 60 hours of permitting 

authority time per residential or commercial permit. 

Based on these assumptions, the additional annual 

permitting burden for permitting authorities, on a 

national basis, is estimated to be 3.3 million hours 

at a cost of $257 million to include all GHG emitters 

above the 250-tpy threshold. 

74 FR at 55,301 col. 2. 

Note that at the proposal, in calculating the PSD 

administrative burdens that would occur each year due to GHG 

emissions, we did not undertake separate calculations for the 

administrative burdens associated with permitting obligations 

stemming from the GHG emissions of the 280 sources already 

subject to PSD permitting requirements due to their conventional 

pollutants. In effect, we treated these 280 sources are part of 

the over 40,000 sources that would become subject to PSD due to 

their GHG emissions. 

The second way that we evaluated the burden on permitting 

authorities was by reviewing a study conducted by state and 

local air permitting agencies. As we said in the preamble: 

In addition to conducting our burden analysis, we 

also reviewed summary information from state and local 

air permitting agencies regarding additional resources 

and burden considerations if GHG sources that emit 

above the 100/250-tpy thresholds were subjected to the 

PSD and title V programs. This information covered 43 

state and local permitting agencies, representing 
116

programs from different regions of the country and 

various permitting program sizes (in terms of 

geographic and source population coverage).... This 

information showed significant burdens projected by 

permitting agencies with adding sources of GHG 

emissions in terms of staffing, budget, and other 

associated resource needs. Importantly, the agencies 

based their analysis on the assumption that, for 

purposes of determining whether a source is major, its 

emissions would be calculated on an actual emissions 

("actuals") basis, and not on a PTE basis. On an 

actuals basis, the agencies estimated a 10-fold 

increase in the number of permits. 

Specifically, the agencies estimated that: 

• Assuming, again, that number of permits was 

to increase by 10-fold (based on actual 

emissions), the resulting workload would 

require an average of 12 more FTEs per 

permitting authority at an estimated cost of 

$1 million/year; 

• Without the additional FTEs, the average 

processing time for a permit would increase 

to 3 years, which is three times the current 

average processing time; 

• Permitting authorities would need 2 years on 

average to add the necessary staff; 

• Permitting authorities would also need, on 

average, eight additional enforcement and 

judicial FTEs; 

• Ninety percent of the permitting agencies 

indicated that their staff would need 

training in all aspects of permitting for 

sources of GHG emissions. 

• A quarter of the permitting agencies reported 

that they were currently under a hiring freeze. 

 We went on to explain that this state survey 

significantly underestimated the administrative burdens: 

It is important to reiterate that the state and 

local permitting information on burden was based on 

the number of additional facilities subject to PSD 

because their emissions of GHGs exceed the 100/250-tpy 
117

thresholds at actual emissions rates, not PTE-based 

emissions rates. However, the PSD applicability 

requirements are based on PTE. By adjusting the 

increase in number of permits to account for GHG 

sources that exceed the 100/250-tpy applicability 

thresholds based on their PTE emissions, EPA estimated 

a 140-fold increase in numbers of PSD permits, much 

more than the 10-fold increase estimated by the states 

based on actual emissions. 

74 FR at 55,301 col. 2-3. 

In addition to PSD, we also estimated title V burdens at 

the statutory threshold. At proposal, for the title V program, 

we estimated the administrative burdens that would result from 

applying title V requirements at the 100 tpy major source 

threshold level in the same two ways as for PSD, as follows: 

The first method was to calculate the administrative burdens in 

terms of workload hours, which we then converted to monetary 

costs. To make the workload calculation, we first estimated the 

number of existing GHG-emitting sources that would become 

subject to title V. Based on our GHG threshold data analysis, 

we estimated that approximately 6 million sources would become 

subject to title V. Compared to the 14,700 title V permits 

currently issued per year, this would be an increase in permits 

of more than 400-fold. We noted, in addition, that most of the 

14,700 sources already subject to title V also emit GHGs and may 

be affected as well. 
118

We then described the type of work that the permitting 

authorities would need to do for these GHG-emitting sources – 

the six million that would become newly subject to title V and 

most of the 14,700 that are already subject to title V – as 

follows. Note at the outset that the permitting authorities’ 

workload is greater for sources newly subject to title V than 

for existing sources that seek a revised or renewed permit. As 

EPA noted in the preamble: 

[T]he[] permits [for the six million new sources] 

would need to include any requirements for non-GHGs 

that may apply to the source, such as provisions of an 

applicable State Implementation Plan (SIP). For any 

such requirements, permitting authorities would also 

need to develop terms addressing the various 

compliance assurance requirements of title V, 

including monitoring, deviation reporting, six-month 

monitoring reports, and annual compliance 

certifications. 

Adding to the burden described above would be the 

burden to add GHG terms to the 14,700 existing title V 

permits. While, in general, existing title V permits 

would not immediately need to be revised or reopened 

to incorporate GHG (because as noted above, there are 

generally not applicable requirements for GHGs that 

apply to such sources), permitting authorities may 

face burdens to update existing title V permits for 

GHG under two possible scenarios: (1) EPA promulgates 

or approves any applicable requirements for GHGs that 

would apply to such a source, which would generally 

require a permit reopening or renewal application, or 

(2) the source makes a change that would result in an 

applicable requirement for GHGs to newly apply to the 

source, such as PSD review, which would generally 

require an application for a permit revision. 

Permitting authorities will also need to process 

permit renewal applications, generally on a five-year 

cycle, and such renewals would need to assure that the 

permit properly addresses GHG. Finally they would 
119

have to process title V applications for new sources 

(including all the PSD sources previously discussed). 

 

74 FR at 55,302 cols. 2-3. 

In light of those demands, we estimated the per-permit 

burden on permitting authorities as follows. Note, at the 

outset, that as with PSD, we based the workload hours on 

information in ICRs for industrial sources, and we then assumed 

that the workload for commercial and residential sources would 

be the indicated percentage of the workload for industrial 

sources: 

As with PSD, we have quantified the extent of the 

administrative problem that would result in workload 

hours and cost on the basis of information concerning 

hours and costs for processing existing title V 

permits that is indicated on ICRs. However, we 

recognize that more than 97 percent of these new 

sources would be commercial and residential sources. 

We estimate that for permitting authorities, the 

average new commercial or residential permit would 

require 43 hours to process, which is 10 percent of 

the time needed for the average new industrial permit. 

For an average existing permit, which permitting 

authorities would need to process through procedures 

for significant revisions and permit renewals, adding 

GHG emissions to the permit would result in, we 

estimate, 9 additional hours of processing time, which 

is 10 percent of the amount of time currently 

necessary for processing existing permits. We 

estimate that the total nationwide additional burden 

for permitting authorities for title V permits from 

adding GHG emissions at the 100-tpy threshold would be 

340 million hours, which would cost over $15 billion. 

74 FR at 55,302 col. 3. 
120

As with PSD, the second way that we evaluated the burden on 

permitting authorities at the statutory threshold was by 

reviewing a study conducted by state and local air permitting 

agencies of the burden of applying title V to existing GHGemitting sources at the 100 tpy statutory threshold level. As 

we said in the preamble to the proposed rule: 

[W]e also reviewed summary information from state 

and local permitting agencies, which showed 

significant burdens associated with adding GHGs in 

their title V programs in terms of staffing, budget, 

and other associated resource needs.19 Again, note 

that the permitting agencies based their estimates on 

numbers of permits that would be required from sources 

subject to the 100-tpy title V applicability threshold 

on an actuals—not PTE—basis. Based on that level, the 

agencies assumed a 40-fold increase in numbers of 

permits, and estimated that: 

• The resulting workload would require an average 

of 57 more FTEs per permitting agency at an 

estimated cost of $4.6 million/year; 

• Without the additional FTEs, the average 

processing time for a permit would increase to 

almost 10 years, which is 20 times the current 

average permit processing time; 

• Permitting authorities would need 2 years on 

average to add the necessary staff; 

• On average, permitting authorities would need 29 

additional enforcement and judicial staff; 

• Eighty percent of the permitting authorities 

indicated that their staff would need training in 

all aspects of permitting for sources of GHG 

emission. 

• A quarter of the permitting agencies reported 

that they were currently under a hiring freeze. 

 19 “NACAA Summary on Permitting GHGs Under the Clean Air Act”; 

Memorandum from Mary Stewart Douglas, National Association of 

Clean Air Agencies to Juan Santiago, EPA/OAQPS, September 3, 

2009. 
121

 As with PSD, we added that this state survey 

significantly underestimated the administrative burdens: 

It is important to reiterate that, as with PSD, 

the state and local information on projected 

permitting burden is based on the number of additional 

facilities subject to title V because their emissions 

of GHGs exceed the 100-tpy thresholds at actual 

emissions rates, not the PTE-based emissions rates. 

However, the title V applicability requirements are 

based on PTE. As noted elsewhere in this preamble, 

the state and local agencies estimated a 40-fold 

increase in numbers of title V permits based on the 

amount of GHG sources' actual emissions. By adjusting 

the summary estimates provided by the state and local 

agencies to account for GHG sources that exceed the 

100-tpy threshold based on their PTE emissions, EPA 

estimated that the average permitting authority would 

need 570 more FTEs to support its title V permitting 

program. 

74 FR at 55,302 col. 3 – 55,303 col. 1. 

(2) Revisions to Proposal Estimates of Permitting Authority 

Burden 

We received numerous comments from state and local 

authorities pointing out how EPA had underestimated the 

administrative burden on the permitting authorities in the 

proposal. State and local authorities stated that in 

particular, EPA underestimated the number of modifications and 

the amount of time it would take permitting authorities to 

process permits, particularly for commercial and residential 

sources. Based on the comments and additional analysis that we 

have conducted, we are revising in several respects our 
122

estimates of the administrative burdens for applying PSD and 

title V at the statutory threshold levels. 

First we present revisions to our analysis regarding the 

burdens at the statutory levels. Before we present those 

changes, we want to note a revision to our methodology that 

affected our estimate of the number of permits currently issued 

under existing programs. We are revising upwards the number of 

sources that are already subject to PSD permitting requirements 

anyway for their conventional pollutants (“anyway” sources). 

This revision has implications both for (i) the number of 

sources that would become subject to PSD due to their GHG 

emissions; and also (ii) the baseline number of sources already 

subject to PSD, which we use to compare the amount of increases 

in administrative burden due to permitting GHG sources. At 

proposal, we stated that 280 sources each year are subject to 

PSD due to their new construction or modifications. However, 

upon further analysis, we have realized that this figure is too 

low because it includes only sources that have emissions of one 

or more NAAQS pollutants at the 100/250 tpy thresholds and that 

are located in areas of the country that are designated 

attainment or unclassifiable for all of those pollutants, and 

thus are not designated nonattainment for any of those NAAQS 

pollutants. We estimate that another 520 sources have emissions 
123

of one or more NAAQS pollutants at the 100/250 tpy thresholds 

and are located in areas of the country that are nonattainment 

for at least one of those NAAQS pollutants. Some of these 520 

sources may also emit one or more pollutants at the 100/250 tpy 

level for which their area is designated attainment or 

unclassifiable, and therefore may be subject to PSD for those 

pollutants. Accordingly, the correct number of “anyway” sources 

subject to PSD each year is the 280 sources that are located in 

areas that are attainment or unclassifiable for each pollutant 

that the sources emits at the 100/250 tpy level, plus at least 

some of the 520 sources that are located in areas that are 

nonattainment for at least one of the NAAQS pollutants that the 

sources emit at or above the 100/250 tpy threshold. In the 

absence of data on the number of nonattainment NSR permits that 

do not have a PSD component, and because we expect this to be a 

small number, we have assumed for purposes of this action, that 

each of the 520 sources is subject to PSD for at least one 

pollutant, so that we will consider all 800 sources as subject 

to PSD. Of this number, we estimate that 70 percent, or 560 

sources will undergo a modification, while the remaining 240 

permitting actions involve new construction, would become 

subject to additional requirements due to their GHG emissions 

because those sources have combustion-related activities that 
124

would likely emit GHGs in the requisite quantities. Our 

estimate of 80 percent of permitting activities significantly 

involving combustion activities is based on a review of a random 

sample of PSD permits. In total we estimate that 688 sources, 

either upon new construction or modification, would need to add 

GHG requirements to their otherwise required PSD permitting 

action. 

We should also note that in this rulemaking we are 

justifying our conclusions about permitting authority 

administrative burdens on the basis of their PSD and title V 

cost as calculated on both a separate basis and a combined 

basis. That is, we believe that the administrative burdens of 

the PSD program justify our tailoring approach for the PSD 

requirements, and the administrative burdens of the title V 

program justify our tailoring approach for the title V 

requirements, but addition, the administrative burdens of both 

programs on a combined basis justify the tailoring approaches. 

Viewing the administrative burdens on a combined basis provides 

a useful perspective because most permitting authorities have a 

single organizational unit that is responsible for both the PSD 

program and the title V program, and in many cases, the same 

employees work on both programs. In addition, in some 

jurisdictions, permitting authorities issue a single, merged 
125

permit that includes both PSD and title V requirements. For 

these reasons, considering administrative burdens on a combined 

PSD and title V basis, offers a more accurate picture of the 

issues these agencies will face in transitioning to GHG 

permitting. 

Turning to the revisions to our burden estimates that we 

made as a result of public comment, we begin by noting that many 

commenters believed that we significantly underestimated the 

administrative burdens associated with the proposed thresholds 

or that the administrative burden under the proposed thresholds 

would still overwhelm the states and result in significant 

permitting delays and uncertainty for sources. Many of these 

commenters indicate that our estimate of the number of sources 

that would be subject to permitting is too low, and some add 

that we have underestimated the per-permit effort required. 

(More detail on these comments is given elsewhere on the 

methodology used in the analysis.) Several state and local 

agencies provided estimates of the increased number of permits 

and/or staff that would be required under the thresholds we 

proposed that were higher than our original estimates. 

Specifically, commenters recommended that we increase the 

estimated administrative burdens for PSD permits from 100 

percent to over 2,000 percent; and that we increase the burdens 
126

for title V permits from 29 percent to 240 percent. Many 

commenters indicated that EPA has not adequately accounted for 

“synthetic minor” sources or modification projects, stating that 

many such sources and projects will not be able to keep GHGs 

below the proposed thresholds, and those who could do so may not 

be able to establish enforceable synthetic minor limits. 

Numerous commenters also stated that the EPA has underestimated 

the rate of major modifications for GHGs under PSD. Some 

commenters assert that we underestimated the number of permits 

required for specific industry sectors, including the oil and 

gas production industry, the natural gas transmission industry, 

the semiconductor industry, the wood products industry, the 

brick industry, and landfills. Some of the state and local 

commenters also believe that we have overestimated their ability 

to hire and train sufficient staff to administer GHG permitting. 

We are persuaded by the data and arguments provided by the 

many commenters who believe EPA underestimated the number of 

permitting actions and the burdens of each action, and thus the 

overall administrative burdens associated with permitting GHG 

sources. Accordingly, we have reevaluated our assessment of 

these administrative burdens, for both the PSD and title V 

programs. In conducting this re-evaluation, we considered 

arguments made by the commenters, as well as any actual data 
127

they provided, and then we determined whether and how to modify 

various aspects of our detailed assessment of the burdens. 

Based on this consideration we have substantially revised 

upwards our estimate of administrative burdens, based on the 

analysis included in the final docket for this rulemaking.20 The 

revisions affect two elements of our analysis: (1) a 

substantial increase the number of PSD and title V permits that 

will occur at the statutory thresholds, and (2) an increase in 

the average burden estimate for each such permit. 

 Regarding the increase in our estimate of the number of 

projects that will occur, we estimated an increase in both PSD 

and title V permit actions, though the greatest changes were for 

PSD. At proposal, we estimated that, were PSD requirements to 

apply to GHG sources at the 100/250 tpy statutory levels, 40,496 

projects -- consisting of 3,299 projects at industrial sources 

and 37,197 projects at commercial or residential sources -- 

would need PSD permits each year. Some of these projects 

involve the construction of an entirely new source, but the 

majority of these are modifications. We now estimate that at 

the 100/250 tpy levels, 81,598 projects would become subject to 

PSD each year. These projects include 26,089 actions at 

 20 “Summary of Methodology and Data Used to Estimate Burden 

Relief and Evaluate Resource Requirements at Alternative 

Greenhouse Gas (GHG) Permitting Thresholds;” Prepared by EPA 

Staff; March 2010. 
128

industrial sources and 55,509 at commercial and residential 

sources. We describe our calculation of this 81,598 amount in a 

TSD.21 The great majority of these 81,598 projects that would 

become subject to PSD are modifications. We base these 

estimates on the assumption that the significance levels would 

be 100 tpy regardless of category. 

Our estimate of the number of PSD modifications is where we 

made our most significant upward revisions from our proposal, 

based on comments. Our doubling of the estimated PSD permitting 

actions – from 40,496 at proposal to 81,598 -- results from 

three separate adjustments we made to our estimates at proposal 

of the number of permit actions that would result from applying 

PSD to GHG sources. Two of these increased the number of major 

modifications, and one of these increased the number of major 

sources and modifications. The most significant adjustment, and 

one that was raised by multiple commenters, was that we 

undercounted the number of major modification projects at 

existing major sources because we did not include the existing 

projects that avoid major PSD review by either taking “synthetic 

minor” limits or by netting out for conventional pollutants, but 

that would not be able to avoid PSD through those mechanisms for 

 21 “Summary of Methodology and Data Used to Estimate Burden 

Relief and Evaluate Resource Requirements at Alternative 

Greenhouse Gas (GHG) Permitting Thresholds;” Prepared by EPA 

Staff; March 2010. 
129

GHGs. The ability and procedures for sources to achieve 

reductions, or minimize increases, due to GHGs through adoption 

of enforceable limits or through netting out have not be well 

established at this point. We believe that there will numerous 

instances, particularly for combustion-related projects, where 

it will not be possible for sources to achieve the same level of 

reductions for CO2 emissions as they do for NOx emissions, for 

example, simply because there are not as many proven control 

techniques that can reduce CO2 emissions to the same degree as 

NOx. Also, more research will be necessary in the type of 

emission units and processes resulting in GHG emissions, and how 

they operate over a wide range of utilization patterns at a 

variety of source categories, before permitting authorities will 

be able to establish procedures and rules for developing minor 

source permit limitations. Therefore, we adjusted our count of 

major modification permits under PSD upward to account for this. 

The second change to the number of permits concerns the 

general modification rate of 2 percent that we applied at 

proposal, based on historical experience across all pollutant 

types. Commenters provided information that suggest that this 2 

percent figure is an underestimate for GHG sources because their 

emissions of CO2 are high and accumulate quickly from various 

changes involving combustion units. Therefore, a greater 
130

percentage of their physical or operational changes will result 

in GHG emissions in excess of the significance levels that we 

identified at proposal. In light of these comments, we reviewed 

the source populations and pollutant mix within the various 

populations, and determined that we should revise our general 

modification rate to 4 percent for GHG sources. This 4 percent 

rate was obtained by dividing the current annual major NSR 

permit actions involving modifications by the 14,700 existing 

sources. We have revised our burden analysis accordingly. 

Again, the burden analysis in the docket describes our basis for 

these calculations in more detail. 

The third adjustment to the number of permits involves our 

estimate of the number of sources with potential to emit that is 

greater than the various thresholds considered. This affects 

the number of major sources at the statutory thresholds, which 

we used to estimate the number of PSD and title V major sources, 

but also has an effect on the number of major modifications 

because the number of modifications depends on the size of the 

population of major sources. Commenters provided evidence that 

our estimates of capacity utilization (which, as described 

previously, we use for estimating potential-to-emit based on 

data for actual emissions) for the general manufacturing source 

category (referred to as “unspecified stationary combustion” in 
131

our analysis) and for the oil and gas industry were not 

accurate. In our proposal, our estimated range for capacity 

utilization for ‘unspecified stationary combustion” varied from 

70 to 90 percent depending on manufacturing category. For the 

oil and gas industry, our estimate was 90 percent. We received 

comments indicating that these utilization rates are higher than 

what is normally achieved in real-world conditions, particularly 

for smaller manufacturing type facilities. Accordingly, in this 

action, we are using a 50 percent capacity utilization rate for 

both of these source categories, which better reflects what can 

be deemed reasonable operation under normal conditions for 

facilities in these source categories. This adjustment 

increased the overall number of affected facilities at various 

threshold levels and we have revised our burden analysis 

accordingly. 

 A few commenters asserted that we underestimated the number 

of residential homes, commercial buildings, and retail stores 

that would be subject to permitting requirements because these 

commenters believed the estimate in EPA’s TSD was based on 

actual emissions from space heating equipment rather than PTE. 

We wish to clarify that our threshold analysis estimates for the 

number of residential and commercial sources (as well as all 

other sources) did use a PTE basis. To calculate the PTE amount 
132

for these sources, we extrapolated from the actual emissions 

data for the residential and commercial sources. Specifically, 

we assumed that a typical residential facility operates its fuel 

combustion sources at only 10 percent of its capacity and a 

typical commercial facility operates at only 15 percent of its 

capacity. Based on these assumptions, we multiplied residential 

actual emissions by a factor of 10, and commercial actual 

emissions by a factor of 6.6 to obtain PTE-based estimates. 

There is very little information available on the capacity 

utilization rates of fuel combustion equipment at different 

types of residential and commercial facilities, but we believe 

our methodology was reasonable for these types of sources and we 

did not adjust it in response to this comment. Information on 

the development of these estimates is provided in our Technical 

Support Document for Greenhouse Gas Emissions Thresholds 

Evaluation. 

 The second source of upward revisions to our 

administrative burden estimate is that we are increasing the 

estimated average cost to permitting authorities of issuing each 

PSD and title V permit at the statutory thresholds. At 

proposal, we estimated that for PSD permits, permitting 

authorities would expend, on average, 301 hours to permit an 

industrial source of GHG emissions, and 20 percent of that time, 
133

or 60 hours to permit a commercial or residential source. After 

estimating that amount of workload, we went on to estimate the 

monetary cost to permitting authorities of that workload. 

Similarly, for title V permits, we estimated at proposal that 

permitting authorities would expend 10 percent of the number of 

hours needed to process an industrial permit in order to process 

a commercial or residential permit for GHG sources. 

We received comments from both permitting authorities and 

sources asserting that our methodology underestimated the 

administrative burden on grounds that (1) our methodology fails 

to recognize that when a source triggers PSD for conventional 

pollutants, additional labor hours would be required to issue 

BACT for GHGs; (2) our estimate of 60 hours (versus 301 hours) 

to issue PSD permits to commercial and residential sources of 

GHGs is unrealistically low; (3) our estimate failed to account 

for the increase in the complexity of permits for criteria 

pollutants due to (i) increases in criteria pollutant emissions 

becoming newly subject to BACT at sources that are major only 

for GHGs, which will result in increased permitting and (ii) 

BACT controls for criteria pollutants (e.g., an oxidizer for 

VOC) may result in significant GHG emissions, triggering an 

additional BACT determination.; and (4) our methodology failed 

to account for the significant additional PSD and title V 
134

burdens due to sources that obtain federally enforceable permit 

limits on GHGs in order to become “synthetic minors” and thereby 

avoid PSD (and possibly also title V). 

 Based on these comments and our own reassessment of 

permitting actions created by the addition of GHGs, we have 

revised upwards in several ways our estimate of the additional 

per-permit costs of applying PSD and title V to GHG sources, 

including the following: First we have added an estimate of the 

additional permitting cost for adding a GHG component to 

“anyway” PSD and title V permitting actions for conventional 

pollutants. We estimated this burden based on information in 

the comments together with our own judgment about how to adjust 

the burden numbers contained in the current supporting 

statements for our approved permitting ICRs. These adjustments 

are found in our revised burden estimate document 22

Second, we have raised the per-permit burden hours for 

commercial and residential sources for PSD and title V. At 

proposal, our estimates were based on the fact that many of 

these permits will be technically simpler due to such factors as 

a lower number of emissions points, simpler processes, and less 

required modeling. However, commenters pointed out that, until 

 22 “Summary of Methodology and Data Used to Estimate Burden 

Relief and Evaluate Resource Requirements at Alternative 

Greenhouse Gas (GHG) Permitting Thresholds;” Prepared by EPA 

Staff; March 2010. 
135

EPA streamlines its permitting procedures, there are many 

permitting activities that represent a fixed cost, such as 

public notice, hearing, and response to comment activities. In 

addition, we agree, as commenters pointed out, that many of 

these sources will need significantly more permitting-authority 

staff time to assist them in the permit application and 

preparation process because of their lack of experience with 

these requirements. In addition, permitting authorities will 

have little, if any, experience in permitting commercial and 

residential sources, and therefore will face a learning curve 

that will entail more time to take permitting action. In 

addition, we expect that in many cases PSD and title V permit 

applications for GHGs will receive comments from various 

stakeholders, from citizens groups to equipment vendors, who 

will seek to participate in the permit process, and responding 

and revising permits accordingly will add to the hours that the 

permitting authority will spend. 

As a result, we raised the PSD per-permit hours for various 

steps in the permitting process, as described in the burden 

estimate document. While we continue to estimate that 

permitting authorities will expend, on average, 301 hours to 

issue a PSD permit to an industrial source, and that this would 

cost $23,243, we now recognize that a permitting authority would 
136

expend 70 percent of that time or 210 hours, to permit a 

commercial or residential source, which would cost $16,216. 

Similarly, for title V, while we continue to estimate that 

permitting authorities will expend, on average, 428 hours to 

issue a title V permit to an industrial source, and that this 

would cost $19,688, we now recognize that a permitting authority 

would expend 50 percent of the time, or 214 hours, to permit a 

commercial or residential source, which would cost $9,844. 

We disagree with commenters who suggested that by basing 

our estimates on the numbers of newly constructing and modifying 

sources with high enough emissions to qualify as major emitting 

facilities, we failed to account for the costs of sources that 

seek “synthetic minor” permits to avoid PSD, and possibly title 

V, requirements. In fact, our methodology includes sources that 

might take such limits as newly-major sources for their GHG 

emissions; and therefore we count the full administrative burden 

associated with a PSD permit and a title V permit for those 

sources. In effect, we assume that such sources would go 

through PSD or title V permitting, rather than take “synthetic 

minor” limits. We take this approach because although we 

suspect that there may, in fact, be significant synthetic minor 

activity, we do not have data that would allow us to determine 

whether, and how many of, these sources will be able to adopt 
137

“synthetic minor” limits or restrict their operations to obtain 

minor source permitting status. Nor do we have data on the 

amount of the administrative burden that would fall on any 

particular permitting authority to establish a “synthetic minor” 

limit, except that we understand that the amount varies widely 

across states. As a result, we opted to include these sources 

in our analysis as sources receiving a PSD or title V permit. 

Therefore, to the extent that synthetic minor activity occurs, 

our estimate would already have included the burden for that 

activity. In fact, our estimate would have overestimated the 

burden to the extent that a permitting authority would have less 

administrative costs to issuing a “synthetic minor” permit, as 

compared to a PSD or title V permit. 

(3) Revised Burden Estimates at Statutory Thresholds 

Based on the revisions just described, we estimate that in 

all, if sources that emit GHGs become subject to PSD at the 

100/250 tpy levels, permitting authorities across the country 

would face over $1.5 billion in additional PSD permitting costs 

each year. This would represent an increase of 130 times the 

current annual burden hours under the NSR major source program 

for permitting authorities. The permitting authorities would 

need a total of almost 10,000 new full time employees (FTEs) to 

process PSD permits for GHG emissions. 
138

In addition, we estimate that in all, if sources that emit 

GHGs become subject to title V at the 100 tpy level, permitting 

authorities across the country would incur about 1.4 billion 

additional work hours, which would cost $63 billion. We 

estimate that most of this work would be done over a 3 year 

period, which would amount to 458 million in additional work 

hours, and $21 billion in additional costs, on an annual basis 

over that 3-year period. 

We also note that the survey of state and local permitting 

authorities described in the proposed rulemaking continues to 

shed light on the extent of the administrative burdens, 

including staffing, budget, and other associated resource needs, 

as projected by the permitting authorities. As noted 

previously, that survey concluded that application of the PSD 

requirements to GHG-emitting sources at the level of 100/250 tpy 

or more of actual emissions would, without additional FTEs, 

increase the average processing time for a PSD permit from one 

to 3 years. The survey further concluded that application of 

the title V requirements to GHG-emitting sources at the level of 

100 tpy or more of actual emissions would, without additional 

FTEs, increase the average processing time for a title V permit 

from 6 months to 10 years. As we noted at proposal, this survey 

assumed a ten-fold increase in the number of PSD permits and a 
139

40-fold increase in the number of title V permits due to GHGemitting sources, but those assumptions were severely 

underestimated because based on actual emissions. At proposal, 

our calculations, which were based on potential emissions, 

indicated a 140-fold increase in PSD permits and a more than 

400-fold increase in title V permits. In this rulemaking, we 

recognize that even our estimates at proposal were severely 

underestimated. We now recognize that the number of PSD permits 

will be about twice what we estimated at proposal, and the 

average processing time for both PSD and title V permits will be 

two or three times greater than what we estimated at proposal. 

The survey of state and local permitting authorities provided 

other useful information as well, including the fact that it 

would take the permitting authorities 2 years, on average, to 

hire the staff necessary to handle a ten-fold increase in PSD 

permits and a 40-fold increase in title V permits, and that 90 

percent of their staff would need additional training in all 

aspects of permitting for GHG sources. 

(4) Revised Estimates of Administrative Burdens at Various 

Threshold Levels 

In order to determine the appropriate PSD and title V 

applicability level for GHG sources, we not only estimated the 

burden at the statutory thresholds, as described previously, but 
140

we also estimated the number of sources, number of permitting 

actions, and amount of administrative burden at various 

applicability levels for both PSD and title V, based on the 

revised methodology described previously, that we used to 

estimate the administrative burdens of applying PSD and title V 

at the statutory levels. This information is summarized in 

Table VI-1, previously. Note that Table VI-1 also includes, in 

the last column, the administrative burdens, described 

previously, associated with the 100/250 tpy thresholds.
141

Table V-1. Coverage and Burden Information

Current 

Program1

“Anyway” 

Source 

Approach 

75k Major 

Mod. 

100k 

Major 

Source 

100k 

Major 

Mod. 

100k 

Major 

Source 

75k 

Major 

Mod. 

100k Major 

Source 

50k Major 

Mod. 

50k Major 

Source 

50k Major 

Mod. 

25k 

S

25k 

M

Number of Major Sources 

15,000 15,000 15,550 15,550 15,550 18,500 22,

Number of Newly Major GHG Sources 

N/A 0 550 550 550 3,500 7,5

Number of PSD New Construction Actions 

240 240 242 242 242 243 250 

Number of PSD Modification Actions at Covered major sources 

448 448 468 1,363 2,257 2,354 9,64

Permitting Authority Cost to Run PSD programs 

$12M/yr. $15M/yr. $15M/yr. $36M/yr. $57M/yr. $59M/yr. $22

Permitting Authority Work Hours to Run PSD programs2

150,795 185,195 192,055 461,450 730,544 764,781 2.9

Permitting Authority Cost to Run Title V Programs 

$62M/yr. $63M/yr. $67M/yr. $69M/yr. $70M/yr. $88M/yr. $12

Permitting Authority Work Hours to Run Title V Programs 

1.35 M 1.38 M 1.46 M 1.49 M 1.53 M 1.92 M 2.74 
142

Annual Total Cost to Run PSD and Title V Programs and percent increase in cost over current program 

$74M/yr. $78M/yr. 

5% increase (once states adopt) 

$82M/yr. 11% increase 

$105M/yr 42% increase 

$127M/yr. 72% increase 

$147M/yr. 99% increase 

$35380% incr

% GHG emissions covered 

-0- 65% 67% 67% 67% 70% 75% 

Notes: (1) As explained in the preamble, "current program" figures for PSD 

reflect NSR permits in nonattainment areas that we assume include a PSD comleast one pollutant. (2) Number of FTEs may be calculated as work hours div

hours. 
143

As described in the TSD, we considered several different 

major source/major modification threshold combinations. We 

chose the combinations to reflect representative, incremental 

steps along the possible range. Because it is time- and 

resource- intensive to develop estimates for a given step, we 

chose intervals that best reflect representative points within 

the range, given those time and resource constraints. Here, we 

discuss key observations about some of the combinations that we 

assessed. As the table indicates, under the current PSD and 

title V programs, approximately 15,000 sources qualify as major 

PSD sources for at least one pollutant and therefore meet the 

applicability thresholds. Of these, approximately 668 sources 

are subject to PSD requirements each year for at least one 

pollutant -- 240 because they undertake new construction, and 

448 because they undertake modifications. The permitting 

authorities’ administrative burdens for the NSR program are 

153,795 work hours, and $12 million. For the title V program, 

the 15,000 sources are, for the most part already permitted, and 

therefore need revised permits as required and renewal permits 

on a 5-year schedule. The permitting authorities’ title V 

administrative burdens on an annual basis are 1,349,659 work 

hours and $62 million. 
144

The first threshold Table 1 describes – and which, as 

discussed later, we are adopting for Step 1 – is the “anyway” 

source approach. Under this approach, (i) PSD applies to the 

GHG emissions from projects that are subject to PSD anyway as 

new sources or major modifications due to their emissions of 

non-GHG pollutants and that result in an increase (or, in the 

case of modifications, a net increase) of at least 75,000 tpy 

CO2e; and (ii) title V applies to what we will call “anyway” 

title V sources, that is, sources that are subject to title V 

anyway due to their emissions of non-GHG pollutants. Under this 

approach, the number of sources subject to PSD each year – 

including new construction and modifications -- is the same as 

under the current program, but the permitting authorities will 

need to address GHG emissions as part of those permitting 

actions each year and, to do so, will require, each year, 34,400 

additional workload hours costing an additional $3 million. For 

title V, we estimate that the number of title V sources that 

require permitting actions will, on average, be the same each 

year, but permitting authorities will need to address GHG 

requirements for some of them; as a result, permitting 

authorities will need, each year, 27,468 additional work hours 

costing $1 million in additional funding. 
145

 Another threshold described in Table VI-1 is the one we are 

adopting under Step 2, as described later, under which (i) 

sources will be subject to PSD on account of their GHG emissions 

if they newly construct and emit at least 100,000 tpy CO2e, or if 

they are existing sources that emit at least 100,000 tpy CO2e of 

GHGs and make a modification that results in a net emissions 

increase of at least 75,000 tpy CO2e; and (ii) existing sources 

will be subject to title V due to their GHG emissions if they 

emit 100,000 tpy CO2e in GHG emissions. Under this approach, 

which we will call the 100,000/75,000 approach, we estimate that 

each year, the permitting authorities will need to issue GHG 

permits to two additional sources that newly construct and 915 

that undertake modifications above current permitting levels. 

Doing so will require 310,655 additional workload hours costing 

an additional $24 million, compared to the current program. For 

title V, an additional 180 sources will require new title V 

permits each year, and the permitting authorities’ associated 

costs will be 160,572 work hours and $7 million more than the 

current program. 

The last approach we will describe here may be called the 

50,000/50,000 approach, which, as discussed later, we adopt as 

the floor for thresholds during the first 6 years after 

promulgation. Under this approach, (i) sources will be subject 
146

to PSD on account of their GHG emissions if they newly construct 

and emit at least 50,000 tpy CO2e, or if they are existing 

sources that emit at least 50,000 tpy CO2e of GHGs and make a 

modification that results in a net emissions increase of at 

least 50,000 tpy CO2e; and (ii) existing sources will be subject 

to title V on account of their GHG emissions if they emit 50,000 

tpy CO2e in GHG emissions. Under this approach, each year, the 

permitting authorities will need to issue GHG permits to 3 

additional sources that newly construct and 1,900 that undertake 

modifications above current permitting levels. Doing so will 

require 613,986 additional workload hours costing $47 million, 

compared to the current program. For title V, an additional 

1,189 sources will require new title V permits each year and the 

permitting authorities’ associated costs will be 568,017 work 

hours and $26 million more than the current program. 

We present the remaining entries in the table to illustrate 

how the cost and burden estimates vary with increasing or 

decreasing thresholds relative to those selected in this rule. 

These variations are important in understanding how alternative 

thresholds would compare to the ones selected. We also include 

entries reflecting the baseline (current program without GHG 

permitting) and the burdens if we immediately implemented the 
147

full statutory thresholds on January 2, 2011, without tailoring 

or streamlining. 

3. Legal Doctrines: “Absurd Results,” “Administrative 

Necessity,” and “Step-at-a-Time” Legal Doctrines 

a. Introduction and Summary 

Having described the factual underpinnings of our action, 

which are the costs to sources and administrative burdens to 

permitting authorities, we now describe the legal underpinnings. 

They involve the framework for analyzing agency-administered 

statutes, as established by the U.S. Supreme Court in Chevron 

U.S.A. Inc. v. NRDC, 467 U.S. 837, 842-43 (1984). In this case, 

Chevron framework must take account the “absurd results,” 

“administrative necessity,” and “one-step-at-a-time” doctrines. 

We believe that each of these doctrines provides independent 

support for our action, but in addition, the three doctrines are 

directly intertwined and can be considered in a comprehensive 

and interconnected manner. Moreover, although the three 

doctrines pre-date the 1994 Chevron decision, in which the U.S. 

Supreme Court established the framework for construing agencyadministered statutes, each of the three doctrines fit 
148

appropriately into the Chevron framework.23

To reiterate, for convenience, the statutory provisions at 

issue: Congress, through the definition of “major emitting 

facility,” applied the PSD program to include “any ... source[ 

that] emit[s], or ha[s] the potential to emit, one hundred [or, 

depending on the source category two hundred fifty] tons per 

year or more or more of any air pollutant.” CAA §§ 165(a), 

 23 Although we set out an analysis of how the three 

doctrines fit into the Chevron framework, we note that even if 

the doctrines are viewed independently of the Chevron framework, 

they support our this action. 
149

169(1). In addition, Congress, through the definition of 

“modification,” applied the PSD program to include “any physical 

change in, or change in the method of operation of, a stationary 

source which increases the amount of any air pollutant emitted 

by such source or which results in the emission of any air 

pollutant not previously emitted.” CAA §§ 165(a), 169(2)(C), 

111(a)(4). Similarly, Congress, through the definition of 

“major source,” specified that the title V program includes “any 

stationary facility or source of air pollutants which directly 

emits, or has the potential to emit, one hundred tons per year 

or more of any air pollutant.” CAA §§ 502(a), 501(2)(B), 

302(j). EPA, through long-established regulatory action, in the 

case of PSD, and long-established guidance, in the case of title 

V, has interpreted these definitions narrowly so that they apply 

only with respect to air pollutants that are subject to 

regulation under the CAA. 

Applying these definitions by their terms, as interpreted 

narrowly by EPA, to greenhouse gas sources at the present time 

would mean that the PSD and title V programs would apply to an 

extraordinarily large number of small sources, the sources would 

incur unduly high compliance costs, and permitting authorities 

would face overwhelming administrative burdens. As a result, we 

decline to follow this literal reading, and instead, with this 
150

action, we chart a course for tailoring the applicability 

provisions of the PSD program and the title V program by phasing 

them in over time to the prescribed extent. 

For our authority to take this action, we rely on the 

“absurd results” doctrine, which applies because applying the 

PSD and title V requirements literally (as previously narrowed 

by EPA) would not only be inconsistent with congressional intent 

concerning the applicability of the PSD and title V programs, 

but in fact would severely undermine congressional purpose for 

those programs. We also rely on the “administrative necessity” 

doctrine, which applies because construing the PSD and title V 

requirements literally (as previously narrowed by EPA) would 

render it impossible for permitting authorities to administer 

the PSD provisions. The tailoring approach we promulgate in 

this action is consistent with both doctrines. It is also 

consistent with a third doctrine, the “one-step-at-a-time” 

doctrine, which authorizes administrative agencies under certain 

circumstances to address mandates through phased action. 

 Our discussion of the legal bases for this rule is 

organized as follows: In this section V.B.3, we provide an 

overview of the three doctrines and describe how they fit into 

the Chevron framework for statutory construction. In section 

V.B.4, we discuss the PSD and title V programs, including each 
151

program’s relevant statutory provisions, legislative history, 

and regulatory history. In sections V.B.5 and V.B.6 we discuss 

the “absurd results” approach for PSD and title V, respectively, 

that we are finalizing in our action. In section V.B.7., we 

discuss additional rulemaking in which we may consider exempting 

certain categories of sources from PSD and title V under the 

“absurd results” doctrine. In section V.B.8, we discuss the 

legal and policy rationale for the phase-in schedule that we are 

adopting for applying PSD and title V to GHG sources. In 

section V.B.9 we discuss the “administrative necessity” approach 

for PSD and title V, respectively. In section V.B.10, we 

discuss the third legal basis for our action, the “one step-ata-time” doctrine. 

b. The “Absurd Results” Doctrine 

Turning first to the “absurd results” doctrine, we note at 

the outset that we discussed the doctrine at length in the 

notice of proposed rulemaking, and we incorporate by reference 

that discussion, although we make some refinements to that 

discussion in this preamble. The starting point for EPA's 

interpretation of the PSD and title V applicability provisions 

and reliance on the “absurd results” doctrine is the familiar 

Chevron two-step analysis. We discuss this analysis in greater 

detail later, but in brief, in interpreting a statutory 
152

provision, an agency must, under Chevron step 1, determine 

whether Congress's intent on a particular question is clear; if 

so, then the agency must follow that intent. If the intent of 

the provision is not clear, then the agency may, under step 2, 

fashion a reasonable interpretation of the provision. Chevron 

U.S.A. Inc. v. NRDC, 467 U.S. 837, 842-43 (1984). 

The courts consider the best indicator of congressional 

intent to be the plain meaning of the statute. However, the 

U.S. Supreme Court has held that the literal meaning of a 

statutory provision is not conclusive “in the ‘rare cases [in 

which] the literal application of a statute will produce a 

result demonstrably at odds with the intentions of the drafters’ 

... [in which case] the intention of the drafters, rather than the 

strict language, controls.” United States v. Ron Pair 

Enterprises, 489 U.S. 235, 242 (1989). This doctrine of 

statutory interpretation may be termed the “absurd results” 

doctrine. 

Although, as just noted, the U.S. Supreme Court has 

described the “absurd results” cases as “rare,” in that case the 

Court seemed to be referring to the small percentage of 

statutory-construction cases that are decided on the basis of 

the doctrine. The D.C. Circuit, in surveying the doctrine over 

more than a century of jurisprudence, characterized the body of 
153

law in absolute numbers as comprising “legions of court 

decisions.” In re Franklyn C. Nofziger, 925 F.2d 428, 434 (D.C. 

Cir. 1991). Indeed, there are dozens of cases, dating from 

within the past several years to well into the 19th century,24 in 

which the U.S. Supreme Court has applied the “absurd results” 

doctrine to avoid the literal application of a statute, or if 

not so holding, has nevertheless clearly acknowledged the 

validity of the doctrine. Some of the more recent of these 

cases include: Logan v. United States, 552 U.S. 23, 36-37 

(2007) (“[s]tatutory terms, we have held, may be interpreted 

against their literal meaning where the words ‘could not 

conceivably have been intended to apply’ to the case at hand 

 24 For early cases in which the U.S. Supreme Court applied 

the “absurd results” doctrine, see Holy Trinity Church v. U.S., 

143 U.S. 457, 516-17 (1892) (“any alien” does not include a 

foreign pastor; Court stated, “It is a familiar rule, that a 

thing may be within the letter of the statute and yet not within 

the statute, because not within its spirit, nor within the 

intention of its makers.... If a literal construction of the 

words be absurd, the Act must be construed as to avoid the 

absurdity”); Chew Heong v. United States, 112 U.S. 536, 555 

(1884) (rejecting a literal interpretation of treaty that would 

have prevented the re-entry of a person into the U.S. upon the 

ground that he did not possess a certificate which did not exist 

prior to his departure, and which could not possibly have been 

issued); Heyenfeldt v. Daney Gold Mining Co., 93 U.S. 634, 638 

(1877) (statutory language expressly referred to past land sales 

and dispositions, “but evidently they were not employed in this 

sense, for no lands in Nevada had been sold or disposed of by 

any act of Congress,” and the language of the statute “could not 

. . . apply to past sales or dispositions, and, to have any 

effect at all, must be held to apply to the future”). 
154

[citation omitted]”); Nixon v. Missouri Municipal League, 541 

U.S. 125, 132-33 (2004) (“any entity” includes private but not 

public entities); Raygor v. Regents of Univ. of Minn., 534 U.S. 

533, 542-45 (2002) (“implying a narrow interpretation of ... ‘any 

claim asserted’ so as to exclude certain claims dismissed on 

Eleventh Amendment grounds”); United States v. X-Citement Video, 

Inc., 513 U.S. 64, 69 (1994) (rejecting a literal interpretation 

of the statutory term “knowingly” on grounds that Congress could 

not have intended the “positively absurd” results that some 

applications of such an interpretation would produce, “[f]or 

instance, a retail druggist who returns an uninspected roll of 

developed film to a customer “knowingly distributes” a visual 

depiction and would be criminally liable if it were later 

discovered that the visual depiction contained images of 

children engaged in sexually explicit conduct”); and Rowland v. 

Cal. Men’s Colony, 506 U.S. 194, 200 (1993) (finding that an 

artificial entity such as an association is not a “person” under 

the statute, and describing the absurdity doctrine as a “common 

mandate of statutory construction”); United States v. Ron Pair 

Enterprises, 489 U.S. 235, 242 (1989) (the plain meaning of a 

statutory provision is not conclusive “in the ‘rare cases [in 

which] the literal application of a statute will produce a 

result demonstrably at odds with the intentions of the drafters’ 
155

... [in which case] the intention of the drafters, rather than the 

strict language, controls”); Green v. Bock Laundry Machine 

Company, 490 U.S. 504 (1989) (provision in Federal Rule of 

Evidence that protects “the defendant” against potentially 

prejudicial evidence, but not the plaintiff, refers to only 

criminal, and not civil, defendants); Public Citizen v. United 

States Dep’t of Justice, 491 U.S. 440, 453-54 (1989) (rejecting 

a broad, straightforward reading of the term “utilize,” on 

grounds that a literal reading would appear to require the 

absurd result that all of FACA’s restrictions apply if a 

President consults with his own political party before picking 

his Cabinet, and such a reading “was unmistakably not Congress’ 

intention”); Watt v. Alaska, 451 U.S. 259, 266 (1981) (rejecting 

reliance on plain statutory language and concluding that the 

term “minerals” in § 401(a) of the Wildlife Refuge Revenue 

Sharing Act applies only to minerals on acquired refuge lands; 

stating “[t]he circumstances of the enactment of particular 

legislation may persuade a court that Congress did not intend 

words of common meaning to have their literal effect”); Train v. 

Colorado Public Interest Research Group, Inc., 426 U.S. 1, 23-

24 (1976) (prohibition in Federal Water Pollution Control Act 

against discharging into navigable waters “pollutants,” which 

are defined to include “radioactive materials,” does not apply 
156

to three specific types of radioactive materials); Jackson v. 

Lykes Bros. S.S. Co., 386 U.S. 731, 735 (1967) (refusing to 

distinguish between a longshoreman hired by “an independent 

stevedore company” and one hired by “the shipowner . . . to do 

exactly the same kind of work,” despite the clear terms of the 

Act, and stating: “[w]e cannot hold that Congress intended any 

such incongruous, absurd, and unjust result in passing this 

Act,” when the Act was “designed to provide equal justice to 

every longshoreman similarly situated”); Lynch v. Overholser,

369 U.S. 705, 710, (1962) (statutory construction is not 

confined to the “bare words of a statute”); United States v. 

Bryan, 339 U.S. 323, 338 (1950) (“Despite the fact that the 

literal language would encompass testimony elicited by the House 

Committee in its questioning of respondent relative to the 

production of the records of the association, the Court will not 

reach that result if it is contrary to the congressional intent 

and leads to absurd conclusions. And we are clearly of the 

opinion that the congressional purpose would be frustrated if 

the words, “in any criminal proceeding,” were read to include a 
157

prosecution for willful default under R.S. § 102.”).25

 The D.C. Circuit has also handed down numerous decisions 

that applied the absurd results doctrine to avoid a literal 

interpretation or application of statutory provisions or that 

have acknowledged the doctrine. Some of the most recent ones 

include: Arkansas Dairy Cooperative Ass’n, Inc., v. U.S. Dep’t 

of Agriculture, 573 F.3d 815 (D.C. Cir. 2009) (rejecting the 

canon of construction that presumes that Congress is aware of 

existing law pertinent to the legislation that it enacts, when 

in this case, the presumption that Congress was aware of the 

Departments definition of “hearing” would lead to “the absurd 

 25 For other U.S. Supreme Court cases, see Utah Junk Co. v. 

Porter, 328 U.S. 39, 44 (1946) (“literalness may strangle 

meaning”); Markham v. Cabell, 326 U.S. 404, 409 (1945) (“The 

policy as well as the letter of the law is a guide to 

decision.”); United States v. American Trucking Associations, 

Inc. 310 U.S. 534 (1940) (the term “employees” in the Federal 

Motor Carrier Act, is limited to employees whose activities 

affect safety); C.V. Sorrels v. U.S., 287 U.S. 435, 446-49 

(1932) (provisions of National Prohibition Act that criminalize 

possessing and selling liquor do not apply if defendant is 

entrapped; Court declines to apply the “letter of the statute” 

because doing so “in the circumstances under consideration is 

foreign to its purpose”); United States v. Katz, 271 U.S. 354, 

362 (1926) (holding that the statutory words “no person” refer 

only to persons authorized under other provisions of the Act to 

traffic alcohol, thus rejecting a literal application of general 

terms descriptive of a class of persons made subject to a 

criminal statute); Hawaii v. Mankichi, 190 U.S. 197, 212-14 

(1903) (refusing to adopt a literal application of the “Newlands 

resolution” which would have entitled every criminal in the 

State of Hawaii convicted of an offense between 1898 – 1900 to 

be set at large, as “surely such a result could not have been 

within the contemplation of Congress”). 
158

result that Congress intended to impose a requirement with which 

the Secretary could not comply;” stating: “Courts, ‘in 

interpreting the words of a statute, [have] some scope for 

adopting a restricted rather than a literal or usual meaning of 

its words where acceptance of that meaning would lead to absurd 

results . . . or would thwart the obvious purpose of the statute 

. . . .’” (quoting In re Trans Alaska Pipeline Rate Cases, 436 

U.S. 631, (1978)); Buffalo Crushed Stone, Inc. v. Surface 

Transportation Board, 194 F.3d 125, 129-30 (D.C. Cir. 1999) 

(regulation of Surface Transportation Board providing that if a 

notice of exemption “contains false or misleading information, 

the use of the exemption is void ab initio” does not apply to a 

notice containing false information when declaring the notice 

void ab initio would undermine the goals of the governing 

statute; a conflict between the “literal application of 

statutory language” and maintaining the integrity of the 

regulatory scheme should be resolved by construing the text in 

accordance with its purpose); Mova Pharm. Corp. v. Shalala, 140 

F.3d 1060, 1068 (D.C. Cir. 1998); U.S. v. Stewart, 104 F.3d 

1377, 1388 (D.C. Cir. 1997); Environmental Defense Fund v. EPA, 

82 F.3d 451, 468-69 (D.C. Cir. 1996) (although Act requires 

that a federal action conform to the SIP that is currently in 

place, EPA may instead require conformity to a revised 
159

implementation plan that state commits to develop; “[t]his is 

one of those rare cases * ** [that] requires a more flexible, 

purpose-oriented interpretation if we are to avoid ‘absurd or 

futile results.’”); American Water Works Ass’n v. EPA, 40 F.3d 

1266, 1271 (D.C. Cir. 1994) (holding that EPA’s interpretation 

of the term “feasible” so as to require a treatment technique 

instead of an MCL for lead is reasonable; the court stated: 

“Indeed, where a literal reading of a statutory term would lead 

to absurd results, the term simply ‘has no plain meaning . . . 

and is the proper subject of construction by the EPA and the 

courts.’ If the meaning of ‘feasible’ suggested by the NRDC is 

indeed its plain meaning, then this is such a case; for it could 

lead to a result squarely at odds with the purpose of the Safe 

Drinking Water Act.” (quoting Chem. Mfrs. Ass’n v. Natural Res. 

Def. Council, Inc., 470 U.S. 116, 126 (1985)) (citation 

omitted); In re Nofziger, 925 F.2d 428, 434-35 (D.C. Cir. 1991) 

(provision authorizing payment of attorney fees to the subject 

of an investigation conducted by an independent counsel of the 

Department of Justice only if “no indictment is brought” against 

such individual does not preclude payment of attorney fees when 

an indictment is brought but is determined to be invalid). 

c. The “Administrative Necessity” Doctrine 
160

In the proposed rulemaking, we also described in 

detail the “administrative necessity” doctrine, 74 FR 55311 

col. 3 to 55318 col. 3, and we incorporate that discussion 

by reference into this notice. Under this doctrine, if a 

statutory provision, however clear on its face, is 

impossible for the agency to administer, then the agency is 

not required to follow the literal requirements, and 

instead, the agency may adjust the requirements in as 

refined a manner as possible to assure that the 

requirements are administrable, while still achieving 

Congress's overall intent. The D.C. Circuit set out the 

doctrine of "administrative necessity" in a line of cases 

that most prominently includes Alabama Power v. Costle, 636 

F.2d 323 (D.C. Cir. 1980). The Court cited the doctrine 

most recently in New York v. EPA, 443 F.3d 880, 884, 888 

(D.C. Cir. 2006). 

In addition, as we stated in the proposed rulemaking, “We 

believe that the administrative necessity case law establishes a 

three-step process under which an administrative agency may, 

under the appropriate circumstances, in effect revise statutory 

requirements that the agency demonstrates are impossible to 

administer so that they are administrable.” 74 FR 55315 col. 1. 

Specifically: 
161

[T]he three steps are as follows: When an agency 

has identified what it believes may be insurmountable 

burdens in administering a statutory requirement, the 

first step the agency must take is to evaluate how it 

could streamline administration as much as possible, 

while remaining within the confines of the statutory 

requirements. The second step is that the agency must 

determine whether it can justifiably conclude that 

even after whatever streamlining of administration of 

statutory requirements (consistent with those 

statutory requirements) it conducts, the remaining 

administrative tasks are impossible for the agency 

because they are beyond its resources, e.g., beyond 

the capacities of its personnel and funding. If the 

agency concludes with justification that it would be 

impossible to administer the statutory requirements, 

as streamlined, then the agency may take the third 

step, which is to phase in or otherwise adjust the 

requirements so that they are administrable. However, 

the agency must do so in a manner that is as refined 

as possible so that the agency may continue to 

implement as fully as possible Congressional intent. 

74 FR 55315 cols. 1-2. 

 It should also be noted that we believe the administrative 

burdens encountered by the state and local permitting 

authorities are fully relevant under the “administrative 

necessity” doctrine. Although the caselaw that discusses the 

doctrine focuses on federal agencies, see 74 FR 55312-14, under 

the CAA, state and local agencies are EPA’s partners in 

implementing provisions of the CAA, and have primary 

responsibility for implementing the PSD program. They generally 

adopt EPA’s PSD requirements in their SIPs, as required under 

CAA section 110(a)(2)(C); and they generally adopt EPA’s title V 

requirements in their title V programs, as required under CAA 
162

section 502(d). They issue the PSD and title V permits and are 

responsible in the first instance for enforcing the terms of the 

permits. In all these respects, the law that the state and 

local permitting authorities administer is both federal and 

state law. Under certain circumstances, EPA may become 

responsible for permit issuance and enforcement in the first 

instance, but even then, EPA may, and frequently has, delegated 

those duties to a state, in which case, the state implements 

federal law directly. Thus, although the PSD and title V 

programs are federal requirements, for the most part, it is the 

states that implement those programs. For this reason, the 

administrative burdens that the states face in implementing the 

programs are relevant in determining the applicability of the 

“administrative necessity” doctrine. 

d. “One-Step-at-a-Time” Doctrine 

In addition to the “absurd results” and “administrative 

necessity” doctrines, another judicial doctrine supports at 

least part of EPA’s Tailoring Rule, and that is the doctrine 

that agencies may implement statutory mandates one step at a 

time, which we will call the “one-step-at-a-time” doctrine. In 

the notice of proposed rulemaking, we also described this 

doctrine and recent case law applied it. 74 FR 55,319 col. 1-3. 

As we noted, that the U.S. Supreme Court recently described the 
163

doctrine in Massachusetts v. EPA, 549 U.S. 497, 524 (2007), as 

follows: “Agencies, like legislatures, do not generally resolve 

massive problems in one fell regulatory swoop;” and instead they 

may permissibly implement such regulatory programs over time, 

“refining their preferred approach as circumstances change and 

as they develop a more nuanced understanding of how best to 

proceed.” We assume familiarity with our discussion in the 

proposal, but we expand upon it here to review the caselaw in 

greater detail and to highlight certain components of the 

doctrine that are particularly relevant to the Tailoring Rule. 

The roots of the doctrine go back at least to the D.C. Circuit’s 

1979 decision in United States Brewers Association, Inc. v. EPA, 

600 F.2d 974 (D.C. Cir. 1979). There, the Court considered a 

challenge to EPA’s guidelines for managing beverage containers, 

which EPA was required to promulgate under the Resource 

Conservation and Recovery Act of 1976 (RCRA). RCRA gave EPA one 

year to promulgate the guidelines. EPA promulgated a partial 

set of guidelines, started two others, and was challenged before 

the year was out by petitioners who objected to the initial 

guideline, saying it fell short of the statutory mandate. The 

Court upheld the initial guideline, stating: “Under these 

circumstances we think the question of whether the Agency has 

fully satisfied the mandate of the statute is not fit for 
164

judicial review at this time, when the Agency, still well within 

the one-year period granted by statute, is deeply involved in 

the process of formulating rules designed to carry out the 

congressional mandate. The Agency might properly take one step 

at a time.” States Brewers Association, Inc. v. EPA, 600 F.2d 

at 982. 

The Court addressed the doctrine at greater length in 

National Association of Broadcasters v. FCC, 740 F.2d 1190, 

1209-14 (D.C. Cir. 1984). There, the Court noted that under 

certain statutory schemes, step-by-step agency action might not 

be authorized; but the Court emphasized that when it is 

authorized, it may offer significant benefits; and the Court 

went on to delineate some of the circumstances under which its 

use is justified. In that case, the Court held that FCC acted 

reasonably in making a spectrum allocation decision that granted 

direct broadcast satellite service priority use of a GHG band in 

five-years time, and -- although acknowledging that fixed 

service users that were, at that time, using that band, would 

have to relocate to other bands – in postponing the details of 

the fixed service relocation to future proceedings. The Court 

described in some detail “[t]he circumstances under which ... [an] 

agency may defer resolution of problems raised in a rulemaking,” 

as follows: 
165

The requisite judgment is in essence a pragmatic one. In 

an ideal world, of course, agencies would act only after 

comprehensive consideration of how all available 

alternatives comported with a well-defined policymaking 

objective, and in some circumstances, statutes indeed 

mandate that agencies proceed by only such a course.... But 

administrative action generally occurs against a shifting 

background in which facts, predictions, and policies are in 

flux and in which an agency would be paralyzed if all the 

necessary answers had to be in before any action at all 

could be taken.... We have therefore recognized the 

reasonableness of [an agency’s] decision to engage in 

incremental rulemaking and to defer resolution of issues 

raised in a rulemaking even when those issues are ‘related’ 

to the main ones being considered.... At the same time, [an 

agency] cannot ‘restructure [an] entire industry on a 

piecemeal basis’ through a rule that utterly fails to 

consider how the likely future resolution of crucial issues 

will affect the rule’s rationale.... 

Drawing a line between the permissible and the 

impermissible in this area will generally raise two 

questions. First the agency will likely have made some 

estimation, based upon evolving economic and technological 

conditions, as to the nature and magnitude of the problem 

it will have to confront when it comes to resolve the 

postponed issue. With regard to this aspect of the 

agency’s decision, as long as the agency’s predictions 

about the course of future events are plausible and flow 

from the factual record compiled, a reviewing court should 

accept the agency’s estimation.... Second, once the nature 

and magnitude of the unresolved issue is determined, the 

relevant question is whether it was reasonable, in the 

context of the decisions made in the proceeding under 

review, for the agency to have deferred the issue to the 

future. With respect to that question, postponement will 

be most easily justified when an agency acts against a 

background of rapid technical and social change and when 

the agency’s initial decision as a practical matter is 

reversible should the future proceedings yield drastically 

unexpected results. In contrast, an incremental approach 

to agency decision making is least justified when small 

errors in predictive judgments can have catastrophic 

effects on the public welfare or when future proceedings 

are likely to be systematically defective in taking into 

account certain relevant interests.... 
166

740 F.2d at 1210-11 (citations omitted). 

In City of Las Vegas v. Lujan, 891 F.2d 927 (D.C. Cir. 

1989), the Court suggested that one component of its upholding 

partial agency compliance with a statutory directive is evidence 

that the agency was on track for full compliance. There, the 

Court upheld the Department of Interior’s decision to list the 

population of desert tortoises living north and west of the 

Colorado River (the “Mojave” population) as endangered species, 

but not the nearby population living south and east of the river 

(the “Sonoran” population). The agency explained that the 

Mojave population faced certain threats that the Sonoran 

population did not, and the Court found nothing to fault in that 

reasoning. The Court added: “Since agencies have great 

discretion to treat a problem partially, we would not strike 

down the listing if it were a first step toward a complete 

solution, even if we thought it ‘should’ have covered both the 

Mojave and Sonoran populations.” City of Las Vegas v. Lujan, 

891 F.2d 927, 935 (D.C. Cir. 1989) (footnote omitted). 

In Grand Canyon Air Tour Coalition v. F.A.A., 154 F.3d 455 

(D.C. Cir. 1998), the D.C. Circuit added another component to 

the “one-step-at-a-time” doctrine: While reiterating that 

“ordinarily, agencies have wide latitude to attack a regulatory 
167

problem in phases and that a phased attack often has substantial 

benefits,” id. at 471, the Court went on to uphold partial 

agency action even when that action was long-delayed. There, 

the relevant statute was the Overflights Act, which required the 

Federal Aviation Administration (FAA) to reduce aircraft noise 

from sightseeing tours in Grand Canyon National Park, and 

established the goal of “substantial restoration of natural 

quiet and experience of the park.” The statute required the 

agency to develop a plan to implement the statutory requirements 

within 120 days after enactment, and report to Congress within 2 

years after the date of the plan as to the plan’s success. In 

fact, the FAA did not develop, through rulemaking, a plan until 

ten years after enactment, and when it did, it acknowledged that 

the plan was only a partial one, and that it would need two more 

rules and another ten years to meet the statutory goal of 

substantial restoration. Although recognizing that the 

Overflights Act did not establish an explicit timetable for 

meeting the statutory goal, the Court stated that “[t]he 

language of the Overflights Act does manifest a congressional 

concern with expeditious agency action,” and described the 

agency’s action variously as “tardy,” “undeniably slow,” and 

“slow and faltering.” Id. at 476-77. Even so, the Court upheld 

the FAA’s action against different challenges from appellants 
168

and intervenors that (i) the agency acted unreasonably in not 

promulgating a complete plan to meet the statutory goal, instead 

of promulgating just the first step; and (ii) the agency acted 

unreasonably in not waiting until it had a complete plan before 

promulgating the first step. The Court stated: “We agree that 

it would be arbitrary and capricious for an agency simply to 

thumb its nose at Congress and say – without any explanation – 

that it simply does not intend to achieve a congressional goal 

on any timetable at all....,” but went on to emphasize that the 

FAA’s rule was the first of three that the agency assured would 

achieve the statutory goal. The Court cited City of Las Vegas 

v. Lujan, discussed previously, for the proposition that “a 

court will not strike down agency action ‘if it were a first 

step toward a complete solution.’” Grand Canyon Air Tour 

Coalition v. F.A.A., 154 F.3d 455, 477-78 (D.C. Cir. 1998).26

e. Consistency of Doctrines with Chevron Framework 

Although the “absurd results,” “administrative necessity,” 

and “one-step-at-a-time” doctrines pre-date the Chevron two-step 

analysis for construing statutes that Congress has authorized an 

 26 For other cases, see Arizona Public Service Co. v. EPA, 

562 F.3d 1116, 1125-26 (10th Cir. 2009); General American 

Transp. Corp. v. ICC, 872 F.2d 1048, 1058 (D.C. Cir. 

PLACEHOLDER); Hazardous Waste Treatment Council v. EPA, 861 F.2d 

277, 287 (D.C. Cir. 1988); Western Union International, Inc. v. 

FCC, 725 Fl2d 732, 754 (D.C. Cir. 1984). 
169

agency to administer, we believe that the doctrines can be 

considered very much a part of that analysis. Under Chevron

step 1, an agency must determine whether “Congress has directly 

spoken to the precise question at issue.” If so, “the court, as 

well as the agency, must give effect to the unambiguously 

expressed intent of Congress.” However, if “the statute is 

silent or ambiguous with respect to the specific issue, the 

question for the court is whether the agency’s answer is based 

on a permissible construction of the statute.” 

Chevron U.S.A. Inc. v. NRDC, 467 U.S. 837, 842-42 (1984). 

Thus, step 1 under Chevron calls for determining 

congressional intent for the relevant statutory directive on the 

specific issue presented. To determine Congress’s intent, the 

agency must look first to the statutory terms in question, and 

generally interpret them according to their literal meaning, 

within the overall statutory context, and perhaps with reference 

to the legislative history. If the literal meaning of the 

statutory requirements is clear then, absent indications to the 

contrary, the agency must take it to indicate congressional 

intent and must implement it. Even if the literal meaning of 

the statutory requirements is not clear, if the agency can 

otherwise find indications of clear congressional intent, such 
170

as in the legislative history, then the agency must implement 

that congressional intent. 

The D.C. Circuit has indicated that the “absurd results” 

doctrine fits into the Chevron step 1 analysis in the following 

way: Recall that in the cases in which the courts have invoked 

this doctrine, the literal meaning of the statutory requirements 

has been clear, but has led to absurd results. This can occur 

when the literal meaning, when applied to the specific question, 

conflicts with other statutory provisions, contradicts 

congressional purpose as found in the legislative history – and, 

in particular, undermines congressional purpose – or otherwise 

produces results so illogical or otherwise contrary to sensible 

public policy as to be beyond anything Congress would reasonably 

have intended. See United States v. Ron Pair Enterprises, 489 

U.S. 235, 242-43 (1989); Griffin v. Oceanic Contractors, Inc., 

458 U.S. 564, 571 (1982).

Under these circumstances, the agency must not take 

the literal meaning to indicate congressional intent. As 

the D.C. Circuit has explained, “where a literal reading of 

a statutory term would lead to absurd results, the term 

‘simply has no plain meaning . . . and is the proper 

subject of construction by the EPA and the court.’” 

American Water Works Assn v. EPA, 40 F.3d 1266, 1271 (D.C. 
171

Cir. 1994) (quoting Chemical Manufacturers’ Association v. 

NRDC, 470 U.S. 116, 126 (1985)). Under these 

circumstances, if the agency can find other indications of 

clear congressional intent, then the agency must implement 

that intent. See United States v. Ron Pair Enterprises, 

489 U.S. 235, 242-43 (1989). This may mean implementing 

the statutory terms, albeit not in accordance with their 

literal meaning, but in a way that achieves a result that 

is as close as possible to congressional intent. As the 

D.C. Circuit said in Mova Pharm. Corp. v. Shalala, 140 F.3d 

1060 (D.C. Cir. 1998): 

The rule that statutes are to be read to 

avoid absurd results allows an agency to 

establish that seemingly clear statutory language 

does not reflect the ‘unambiguously expressed 

intent of Congress,’ ... and thus to overcome the 

first step of the Chevron analysis. But the 

agency does not thereby obtain a license to 

rewrite the statute. When the agency concludes 

that a literal reading of a statute would thwart 

the purposes of Congress, it may deviate no 

further from the statute than is needed to 

protect congressional intent. . . . [T]he 

agency might be able to show that there are 

multiple ways of avoiding a statutory anomaly, 

all equally consistent with the intentions of the 

statute’s drafters . . . . In such a case, we 

would move to the second stage of the Chevron

analysis, and ask whether the agency’s choice 

between these options was ‘based on a permissible 

construction of the statute.’ Otherwise, 

however, our review of the agency’s deviation 

from the statutory text will occur under the 

first step of the Chevron analysis, in which we 
172

do not defer to the agency’s interpretation of 

the statute.” 

Id. at 1068 (quoting Chevron U.S.A. Inc. v. NRDC, 467 U.S. 

837, 842, 843 (1984) (citations omitted)). 

The “administrative necessity” doctrine is not as well 

developed as the “absurd results” doctrine, so that the courts 

have not had occasion to explicitly describe how the doctrine 

fits into the Chevron analytical framework. However, we think 

that a reasonable approach, in line with the D.C. Circuit’s 

approach to the “absurd results” doctrine as just described, is 

as follows: Recall that under the “administrative necessity” 

doctrine, an agency is not required to implement a statutory 

provision in accordance with the literal requirements when doing 

so would be impossible, but the agency must nevertheless 

implement the provision as fully as possible. Placed in the 

context of the Chevron framework, we think that that the 

“administrative necessity” doctrine is based on the premise that 

inherent in the statutory design is the presumption that 

Congress does not intend to impose an impossible burden on an 

administrative agency. See Alabama Power v. Costle, 636 F.2d 

323, 357 (D.C. Cir. 1980) (describing the “administrative 

necessity” approach as one of the “limited grounds for the 

creation of exemptions [that] are inherent in the administrative 
173

process, and their unavailability under a statutory scheme 

should not be presumed, save in the face of the most unambiguous 

demonstration of congressional intent to foreclose them”). 

Therefore, if the literal meaning of a statutory directive 

would impose on an agency an impossible administrative burden, 

then that literal meaning should not be considered to be 

indicative of congressional intent. Rather, congressional 

intent should be considered to be to achieve as much of the 

statutory directive as possible. As a result, the agency must 

adopt an approach that implements the statutory directive as 

fully as possible. This is consistent with the D.C. Circuit’s 

holding in Mova Pharm. Corp that if congressional intent is 

clear, but the plain meaning of a statute does not express that 

intent, then the agency must, under Chevron step 1, select an 

interpretation that most closely approximates congressional 

intent. Mova Pharm. Corp, 140 F.3d at 1068.27

 The “one-step-at-a-time” doctrine fits into the Chevron

framework in much the same manner that the “administrative 

necessity” doctrine does. That is, inherent in the statutory 

design is the presumption that Congress intended an agency, 

 27 We recognize that we described the relationship between 

the Chevron framework and the “administrative necessity” 

doctrine somewhat differently in the proposal, 74 FR 55,312/1-2, 

and that, after further analysis, we are refining our view of 

that relationship as described previously. 
174

under certain circumstances, to implement the statutory 

requirements in a one-step-at-a-time fashion, as long as the 

agency stays on a path towards full implementation. 

Under all of the circumstances described previously, 

congressional intent is clear – whether it is indicated by the 

plain language or otherwise – and as a result, the agency must 

follow that intent under Chevron step 1. On the other hand, the 

agency may determine that congressional intent on the specific 

issue is not clear. In these cases, the agencies should proceed 

to Chevron step 2 and select an interpretation or an application 

that is a permissible construction of the statute. This 

situation generally occurs when the statutory provisions are 

ambiguous or silent as to the specific issue, and there are no 

other indications of clear congressional intent. In addition, 

in some cases in which the literal meaning of the statutory 

provision, when applied to the specific question, leads to an 

absurd result – and, therefore, the statutory provision should 

be considered not to have a plain meaning – there may be no 

other indications of clear congressional intent. Under all 

these circumstances, the agency is authorized, under Chevron

step 2, to develop and implement a construction of the statute 

that the courts will uphold as long as it is reasonable. 
175

As noted above, the D.C. Circuit, has pointed out that this 

situation may also occur when the literal language leads to an 

absurd result, and, in attempting to implement congressional 

intent, the agency is “able to show that there are multiple ways 

of avoiding a statutory anomaly, all equally consistent with the 

intentions of the statute’s drafters . . . . In such a case, we 

would move to the second stage of the Chevron analysis, and ask 

whether the agency’s choice between these options was ‘based on 

a permissible construction of the statute.’” Mova Pharm. Corp,

140 F.3d at 1068. As the U.S. Supreme Court has recently said, 

although in a context different than “absurd results,” “ In the 

end, the interpretation applied by EPA "governs if it is a 

reasonable interpretation of the statute -- not necessarily the 

only possible . . . interpretation, nor even the interpretation 

deemed most reasonable by the courts." Entergy Corp. v. 

Riverkeeper, Inc., 129 S.Ct. 1498. 1505 (2009). 

There is another aspect of the “administrative necessity” 

doctrine worth noting: The doctrine applies when (i) a literal 

application of the statutory directive to the case at hand is 

impossible for the agency to administer; and (ii) even so, 

either Congress clearly intended the statutory directive to 

apply to the case at hand or, if Congress did not clearly intend 

that, then the agency reasonably construes the statute to apply 
176

the statutory directive to the case at hand. In contrast, if 

Congress did not intend the statutory directive to apply to the 

case at hand, or if congressional intent is uncertain and the 

agency considers another approach to be reasonable, then the 

“administrative necessity” doctrine would not apply. As a 

result, the agency would not be required to implement the 

statutory directive to the case at hand at all, much less in a 

more administrable fashion. 

f. Interconnectedness of the Legal Doctrines 

Although we believe that each of the “absurd results,” 

“administrative necessity,” and “one-step-at-a-time” doctrine 

provides independent support for our action, we also believe 

that in this case, the three doctrines are intertwined and form 

a comprehensive basis for EPA’s tailoring approach. As just 

discussed, each of the three doctrines is tied into the Chevron

analytical framework because each is designed to give effect to 

underlying intent. As discussed previously, each of the three 

doctrines comes into play in this case because a literal reading 

of the PSD and title V applicability provisions results in 

insurmountable administrative burdens. Those administrative 

burdens -- along with the undue costs to sources -- must be 

considered “absurd results” that would undermine congressional 

purpose for the PSD and title V programs. Under the “absurd 
177

results” doctrine, EPA is authorized not to implement the 

applicability provisions literally – that is, not to implement 

them as applying on the January 2, 2011 date that PSD and title 

V are triggered to all GHG sources at or above the statutory 

thresholds -- but instead to tailor them in a manner consistent 

with congressional intent. That means applying the PSD 

requirements, through a phase-in approach, to as many sources as 

possible and as quickly as possible, starting with the largest 

sources, all as EPA does with this Tailoring Rule.28 By the same 

token, the insurmountable administrative burdens bring into play 

the “administrative necessity” doctrine, under which EPA is, 

again, authorized not to implement the applicability provisions 

literally, but instead to apply them in a manner consistent with 

administrative resources. This also means phasing them in 

through the approach in the Tailoring Rule. Finally, the “onestep-at-a-time” doctrine, which authorizes incremental action by 

agencies to implement statutory requirements under certain 

circumstances, provides further support for the phased tailoring 

approach in the Tailoring Rule. 

g. Application of Chevron Approach 

 28 As discussed later, EPA may, in future rulemaking, make a 

final determination that under the “absurd results” doctrine, 

Congress did not intend for EPA to apply PSD to very small 

sources, that is, those, the emissions from which, are at or 

near the 100/250 tpy statutory levels.
178

The Chevron analytical approach, and the three legal 

doctrines at issue here, apply to this action in the following 

manner: To reiterate, for convenience, the statutory provisions 

at issue: Congress, through the definition of “major emitting 

facility,” applied the PSD program to include (i) “any ... 

stationary sources of air pollutants which emit or have the 

potential to emit, one hundred [or, depending on the source 

category, two hundred fifty] tons per year or more of any air 

pollutant,” CAA §§ 165(a), 169(1); and (ii) and such sources 

that undertake a physical or operational change that “increases 

the amount of any air pollutant emitted” by such sources, CAA §§ 

165(a), 169(2)(C), 111(a)(4).29 Similarly, Congress, through the 

definition of “major source,” specified that the title V program 

includes “any stationary facility or source of air pollutants 

which directly emits, or has the potential to emit, one hundred 

tons per year or more of any air pollutant.” CAA §§ 502(a), 

501(2)(B), 302(j). EPA, through long-established regulatory 

action, in the case of PSD, and long-established interpretation, 

 29 A physical or operational change is treated as a 

“modification” that is subject to PSD if it either “increases 

the amount of any air pollutant emitted” by the source or 

“results in the emission of any air pollutant not previously 

emitted.” For convenience, unless otherwise indicated, when we 

refer to changes that “increase[] the amount of any air 

pollutant emitted,” we mean both to those types of changes and 

changes that “result[] in the emission of any air pollutant not 

previously emitted.” 
179

in the case of title V, has interpreted these definitions so 

that they apply only with respect to air pollutants that are 

subject to regulation under the CAA. 

For each of these applicability provisions, the approach 

under Chevron is as follows: Under Chevron step 1, we must 

determine whether Congress expressed an intention on the 

specific question, which is whether the PSD or title V 

applicability provisions apply to GHG sources. Said 

differently, the specific question is whether, in the case of 

PSD, Congress intended that the definition of major emitting 

facility applies to all GHG sources that emit at least 100 or 

250 tpy or GHGs and to all physical or operational changes by 

major emitting facilities that “increase[] the amount” of GHGs; 

and, in the case of title V, whether the definition of “major 

source” applies to all GHG sources that emit at least 100 tpy 

GHGs. 

To determine intent, we must first examine the terms of the 

statute in light of their literal meaning. Here, the literal 

reading of each provision covers GHG sources. For PSD, a GHG 

source that emits at least 100 or 250 tpy GHGs literally 

qualifies as “stationary source[] of air pollutants which 

emit[s] or ha[s] the potential to emit, one hundred [or two 

hundred fifty] tons per year or more of any air pollutant 
180

[subject to regulation under the CAA].” CAA § 169(1). For 

modifications, a physical or operational change that increases 

the amount of GHG emissions qualifies as a “modification” 

because it “increases the amount of any air pollutant emitted” 

by the source. Similarly, for title V, a GHG source that emits 

at least 100 tpy GHGs literally qualifies as “any stationary 

facility or source of air pollutants which directly emits, or 

has the potential to emit, one hundred tons per year or more of 

any air pollutant [subject to regulation under the CAA].” CAA 

§§ 502(a), 501(2)(B), 302(j). 

However, applying each definition in accordance with its 

literal meaning to GHG sources at the specified levels of 

emissions and at the present time would create undue costs for 

sources and impossible administrative burdens for permitting 

authorities; and these results are not consistent with other 

provisions of the PSD and title V requirements, are inconsistent 

with – and, indeed, undermine – congressional purposes for the 

PSD and title V provisions. Accordingly, under the “absurd 

results” doctrine, neither the PSD nor the title V definitions 

of “major emitting facility” or “modification” and the title V 

definition of “major source,” should be not be applied literally 

to GHG sources, and therefore none should be considered to have 
181

a plain meaning with respect to their application to GHG 

sources. 

In parsing the provisions of each definition more closely, 

we believe that each has three terms, any one of which could be 

considered not to have its literal meaning, in this respect. 

Specifically, each provision includes (i) the term “any ... 

source,” or “a stationary source,” and that term could be 

considered not to refer literally to all of the GHG sources; 

(ii) either the term “two hundred fifty tons per year” or “100 

tons per year,” or the term “increases the amount,” and those 

terms could be considered not to refer literally to the tonnage 

amount of emissions from all of the GHG sources; and (iii) the 

term “any air pollutant30 [subject to regulation under the CAA],” 

and that term could be considered not to refer literally to the 

emissions from all of the GHG sources. As long as any one of 

those three terms should be considered not to have its literal 

meaning as applied to GHG sources, then the definition as a 

whole – again, for PSD, the terms “major emitting facility” or 

“modifications,” and for title V, the term “major source” – 

cannot be considered to apply to GHG sources. Because we read 

the terms together, as integral parts of each definition as a 

 30 As discussed elsewhere, we do not believe that this term 

is ambiguous with respect to the need to cover GHG sources under 

the PSD program, only with respect to what sources of GHG should 

be covered under the circumstances presented here. 
182

whole, we do not think that the choice of which of those three 

terms within each definition cannot be considered to apply 

literally to GHG sources has substantive legal effect. In other 

words, we believe that any one of the three terms, or all three 

together as part of each definition as a whole, should be 

considered not to apply literally in the case of GHG sources. 

Having determined that each definition does not have a 

plain meaning on the specific question of whether PSD or title V 

applies to GHG sources, we must next inquire as to whether 

Congress has nevertheless expressed an intent on that question 

through other means. We discuss the statutory terms and 

legislative history of the PSD and title V provisions in more 

detail later, but for now it suffices to say that on the issue 

of whether PSD and title V apply to GHG sources, we believe that 

congressional intent is clear, and that is to apply PSD and 

title V to GHG sources generally. We believe that the broad 

phrasing of the applicability provisions evidences that intent. 

As a result, we believe that as a matter of Chevron step 1, PSD 

and title V apply to GHG sources. On the issue of how to apply 

PSD and title V to GHG sources, including the specific threshold 

levels and the timing, we believe that Congress could be 

considered to have intended that GHG sources be included in the 

PSD and title V programs at as close to the statutory thresholds 
183

as possible, and as quickly as possible to the greatest extent 

practicable. Under this view, EPA would be required at Chevron

step 1 to adopt the Tailoring Rule because, by phasing in PSD 

and title V applicability, it most closely gives effect to 

Congress’s intent. Under these circumstances, EPA is authorized 

to exercise its expert judgment as to the best approach for 

phasing in the application of PSD and title V to GHG sources. 

Even so, we recognize that it could be concluded that on 

the issue of how to apply PSD and title V to GHG sources, 

congressional intent is unclear. Under these circumstances, EPA 

has the discretion at Chevron step 2 to adopt the Tailoring Rule 

because it is a reasonable interpretation of the statutory 

requirements. Under the Tailoring Rule, EPA seeks to include as 

many GHG sources in the permitting programs at as close to the 

statutory thresholds as possible, and as quickly as possible, 

although we recognize that we ultimately may stop the phase-in 

process short of the statutory threshold levels. 

Further, we are not deciding in this rule whether we 

believe Congress intended to include in the PSD and title V 

programs the smallest GHG sources, which are those emitting at 

or close to the applicability threshold levels. Instead, we 

will decide in subsequent rulemakings whether Congress intended 

to include such sources, intended that such sources not be 
184

included, or did not express an intent; and, if Congress did not 

express an intent, whether it is reasonable policy and 

consistent with the statutory requirements to include them in a 

highly streamlined manner. By the same token, with respect to 

“empty permits” for title V purposes, although, as noted 

elsewhere, we do not believe that Congress intended, under 

Chevron step 1 to preclude title V from applying to GHG sources 

that would have empty permits, we are not deciding whether 

Congress intended, under Chevron step 1 that title V apply to 

GHG sources with empty sources. Similarly, we are not deciding 

whether Congress should be said to have not expressed a clear 

intent, so that the Chevron step 2 analysis would apply. 

It should also be noted that although EPA has concluded 

that applying the PSD and title V applicability provisions 

literally in the case of GHG sources would produce “absurd 

results” and therefore is not required, this conclusion has no 

relevance for applying other CAA requirements – such as the 

requirements concerning endangerment and contribution findings 

under CAA section 202(a)(1) or emission standards for new motor 

vehicles or new motor vehicle engines under CAA section 202 -- 

to GHGs or GHG sources. EPA’s conclusions with respect to the 

PSD and title V applicability requirements are based on the 

specific terms of those requirements, other relevant PSD and 
185

title V provisions, and the legislative history of the PSD and 

title V programs. 

Within the context of the Chevron framework, the 

“administrative necessity” doctrine applies as follows: Under 

the doctrine, Congress is presumed to intend that the PSD and 

title V applicability requirements be administrable. Here, 

those applicability requirements, if applied to GHG sources in 

accordance with their literal meaning, would be impossible to 

administer. Accordingly, under Chevron step 1, it is consistent 

with congressional intent that EPA and the permitting 

authorities be authorized to implement the applicability 

requirements in a manner that is administrable, that is, through 

the tailoring approach. 

As for the “one-step-at-a-time” doctrine, we believe it 

applies within the Chevron framework in conjunction with the 

“absurd results” and “administrative necessity” doctrines. As 

we discuss elsewhere, the PSD and title V applicability 

provisions by their terms require that sources at or above the 

100/250 tpy thresholds comply with PSD and title V requirements 

at the time those requirements are triggered, which is when GHGs 

become subject to regulation. Therefore, if the literal meaning 

of the applicability provisions as applied to GHG sources were 

controlling – that is, if it reflected congressional intent -- 
186

it would foreclose use of the one-step-at-a-time doctrine to 

implement a phase-in approach. However, the literal meaning is 

not controlling because -- in light of the absurd results, 

including the insurmountable administrative burdens, that would 

result from the literal meaning -- congressional intent is not 

to require the application of the PSD and title V requirements 

to all GHG sources at or above the statutory thresholds at the 

time that GHGs become subject to regulation. Instead, as 

described previously, we consider congressional intent for the 

applicability provisions, as applied to GHG sources, either (i) 

to be clear that PSD and title V should be phased in for GHG 

sources as quickly as possible, or (ii) to be unclear, so that 

EPA may reasonably choose to phase PSD and title V in for those 

sources in that manner. Under either view, congressional intent 

for PSD and title V applicability to GHG sources accommodates 

the “one-step-at-a-time” approach. 

4. The PSD and Title V Programs 

Having discussed both the factual underpinnings and, 

immediately above, the legal underpinnings for our tailoring 

approach, we now discuss the PSD and title V programs 

themselves, including, for each program, the key statutory 

provisions, their legislative history, and the relevant 
187

regulations and guidance documents through which EPA has 

implemented the provisions. We start with the PSD program. 

a. The PSD program 

(1) PSD Provisions 

Several PSD provisions are relevant for present purposes 

because of the specific requirements that they establish and the 

window that they provide into congressional intent. These 

provisions start with the applicability provisions, found in CAA 

sections 165(a) and 169(1), which identify the new sources 

subject to PSD, and CAA §111(a)(4), which describes the 

modifications of existing sources that are subject to PSD. CAA 

§165(a) provides: 

 No major emitting facility on which construction 

is commenced after August 7, 1977, may be constructed 

in any area to which this part applies unless— 

 (1) a permit has been issued for such proposed 

facility in accordance with this part setting forth 

emission limitations for such facility which conform 

to the requirements of this part; 

 (2) the proposed permit has been subject to a 

review in accordance with this section * * *, and a 

public hearing has been held with opportunity for 

interested persons including representatives of the 

Administrator to appear and submit written or oral 

presentations on the air quality impact of such 

source, alternatives thereto, control technology 

requirements, and other appropriate considerations; 

* * * 

 (4) the proposed facility is subject to the best 

available control technology for each pollutant 

subject to regulation under this chapter emitted from, 
188

or which results from, such facility * * * *. 

The term "major emitting facility" is defined, under CAA 

§169(1) to include: 

* * * stationary sources of air pollutants which emit, 

or have the potential to emit, one hundred tons per 

year or more of any air pollutant from [28 listed] 

types of stationary sources. * * * Such term also 

includes any other source with the potential to emit 

two hundred and fifty tons per year or more of any air 

pollutant. This term shall not include new or 

modified facilities which are nonprofit health or 

education institutions which have been exempted by the 

State. 

As for modification of existing sources, CAA section 

169(1)(C) provides that the term "construction," as used in CAA 

section 165(a) (the PSD applicability section) "includes the 

modification (as defined in section 111(a)(4)) of any source or 

facility." Section 111(a)(4), in turn, provides: 

The term "modification" means any physical change in, or 

change in the method of operation of, a stationary source 

which increases the amount of any air pollutant emitted by 

such source or which results in the emission of any air 

pollutant not previously emitted. 

As interpreted by EPA regulations, these provisions, taken 

together, provide that new stationary sources are subject to PSD 

if they emit at the 100/250-tpy thresholds air pollutants that 

are subject to EPA regulation, and that existing stationary 

sources that emit such air pollutants at the 100/250-tpy 

thresholds are subject to PSD if they undertake a physical or 

operational change that increases their emissions of such air 
189

pollutants by any amount. 

Other provisions of particular relevance are the 

requirements for timely issuance of permits. The permitting 

authority must “grant[] or den[y] [any completed permit 

application] not later than one year after the date of filing of 

such completed application.” CAA §165(c). 

In addition, the PSD provisions articulate ‘the purposes of 

[the PSD program],” which are to balance environmental 

protection and growth. CAA §160. One of the purposes, in 

subsection (1), is specifically “to protect public health and 

welfare,” and another, in subsection (3), is “to insure that 

economic growth will occur in a manner consistent with the 

preservations of existing clean air resources.” 

The PSD provisions also include detailed procedures for 

implementation. Most relevant for sources of GHG are the 

provisions that the proposed permit for each source must be the 

subject of a public hearing with opportunity for interested 

persons to comment, CAA §165(a)(2), and each source must be 

subject to best available control technology, as determined by 

the permitting authority on a source-by-source basis, CAA 

§165(a)(4), 169(3). 

(2) PSD Legislative History 

The legislative history of the PSD provisions, enacted in 
190

the 1977 CAA Amendments, makes clear that Congress was largely 

on sources of criteria pollutants: primarily sulfur dioxide 

(SO2), PM, NOx, and carbon monoxide (CO). This is evident in the 

basic purpose of the PSD program, which is to safeguard 

maintenance of the NAAQS, combined with the limited awareness at 

that time of the problem of climate change. See S 95-127 (95th

Cong., 1st Sess.), at 27. 

 Congress designed the PSD provisions to impose significant 

regulatory requirements, on a source-by-source basis, to 

identify and implement BACT and, for criteria pollutant, to also 

undertake certain studies. Congress was well aware that because 

these requirements are individualized to the source, they are 

expensive. Accordingly, Congress designed the applicability 

provisions (i) to apply these requirements to industrial sources 

of a certain type and a certain size – sources within 28 

specified source categories and that emit at least 100 tpy -- as 

well as all other sources that emit at least 250 tpy, and, by 

the same token, (ii) to exempt other sources from these 

requirements.31 

 Although Congress required that CAA requirements generally 

 31 Coverage of modifications by the PSD program was 

addressed by a technical amendment which added a cross reference 

in section 169 to section 111. The legislative history of this 

provision is scant and there is no suggestion that Congress 

would have contemplated sweeping in large number of changes from 

smaller sources through the addition of this provision. 
191

apply to “major emitting facilities,” defined as any source that 

emits or has the potential to emit 100 tpy of any pollutant, 

Congress applied PSD to only sources at 100 tpy or higher in 28 

specified industrial source categories, and at 250 tpy or more 

in all other source categories. This distinction was 

deliberate: According to Sen. McClure, Congress selected the 28 

source categories after reviewing an EPA study describing 190 

industrial source categories. 122 Cong. Rec. 24521 (July 29, 

1976) (statement by Sen. McClure). 

 Congress also relied on an EPA memorandum that identified 

the range of industrial categories that EPA regulated under its 

regulations that constituted the precursor to the statutory PSD 

program,32 and listed both the estimated number of new sources 

constructing each year and the amount of pollution emitted by 

the “typical plant” in the category. The memorandum was 

prepared by B.J. Steigerwald, Director of the Office of Air 

Quality Planning and Standards and Roger Strelow, EPA’s 

Assistant Administrator for Air and Waste Management 

(“Steigerwald-Strelow memorandum). The Steigerwald-Strelow 

 32 Beginning in 1974, EPA implemented a program that required 

sources of certain NAAQS pollutants seeking to construct in 

attainment or unclassifiable areas to implement emission 

controls for the purpose of preventing deterioration in the 

ambient air quality in those areas. This program was the 

precursor to the PSD program Congress enacted in 1977. 
192

memorandum makes clear that the 100 tpy cut-off for the 28 

listed sources categories, and the 250 tpy cut-off for all other 

sources, was meaningful; that is, there were a large number of 

sources below those cut-offs that Congress explicitly 

contemplated would not be included in PSD. Id. at 24548-50. 

Consistent with this, the legislative history on the Senate 

side also specifically identified certain source categories that 

Senators believed should not be covered by PSD. The Senate bill 

language limited PSD to sources of 100 tpy or more in 28 listed 

source categories, and to any other categories that the 

Administrator might add. Sen. Muskie stated that the Senate 

bill excluded “houses, dairies, farms, highways, hospitals, 

schools, grocery stores, and other such sources.” 123 Cong. 

Rec. 18021 (June 8, 1977) (statement of Sen. Muskie). Sen. 

McLure’s list of excluded source categories were “[a] small 

gasoline jobber, or a heating plant at a community college, 

[which] could have the potential to emit 100 tons of pollution 

annually.” 122 Cong. Rec. 24548-49 (July 29, 1976) (statement 

of Sen. McClure). The Senate Committee Report included a 

comparable list, and in describing it, concisely articulated the 

cost-conscious basis for the line-drawing: “[the PSD] procedure 

... must include an effective review-and-permit process. Such a 

process is reasonable and necessary for very large sources, such 
193

as new electrical generating plants or new steel mills. But the 

procedure would prove costly and potentially unreasonable if 

imposed on construction of storage facilities for a small 

gasoline jobber or on the construction of a new heating plant at 

a junior college, each of which may have the potential to emit 

100 tons of pollution annually.” S. Rpt. 95-127 at 96-97. 

The enacted legislation differs from the Senate bill by 

replacing the authorization to EPA to include by regulation 

source categories in addition to the listed 28 source categories 

with an inclusion of all other sources if they exceed 250 tpy, 

and with an authorization for the states to exempt hospitals and 

educational institutions. But Congress’s overall intention 

remains clear, as the D.C. Circuit described in Alabama Power: 

"Congress's intention was to identify facilities which, due to 

their size, are financially able to bear the substantial 

regulatory costs imposed by the PSD provisions and which, as a 

group, are primarily responsible for emissions of the 

deleterious pollutants that befoul our nation's air....[With 

respect to] the heating plant operating in a large high school 

or in a small community college . . . [w]e have no reason to 

believe that Congress intended to define such obviously minor 
194

sources as 'major' for the purposes of the PSD provision."33 636 

F.2d at 353-54. 

 A particularly important indication of congressional intent 

to limit PSD to larger sources comes in considering the 

emissions profile of the small-sized boilers. Congress focused 

closely on identifying which sources with emissions in excess of 

100 tpy should not be subject to PSD even though they are 

subject to CAA requirements generally. But Congress viewed a 

large set of sources as emitting below 100 tpy and therefore not 

included in the PSD program and, indeed, not even subject to 

debate as to whether they should be included in the PSD program. 

Chief among these sources, in terms of absolute numbers of 

sources, were small boilers. The Steigerwald-Strelow memorandum 

identified two categories of these boilers, differentiated by 

size. The first ranges in size from 10 to 250 x 106 Btu/hr, and 

has a “typical plant” size of 107

 Btu/hr, with “BACT emissions 

from typical plant” of 53 tpy, and a total of 1,446 sources in 

the category. The second category ranges in size from 0.3 to 10 

x 106

 Btu/hr, and has a “typical plant” size of 1.3 x 106 Btu/hr, 

with “BACT emissions from typical plant” of 2 tpy, and a total 

 33 Note that although Congress specifically authorized the 

states to exempt "nonprofit health or education institutions" 

from the definition of "major emitting facility," this statement 

by the D.C. Circuit should be taken as the Court's view that 

Congress did not design PSD to cover sources of the small size 

described. 
195

of 11,215 sources in the category. The memorandum discusses 

these two categories in the context of explaining which source 

categories exceed a size of 100 tpy -- and therefore would be 

subject to PSD if a 100 tpy threshold were set -- by stating, 

“Fortunately, most truly small boilers and typical space heating 

operations would not be covered.” 122 Cong. Rec. 24549 (July 

29, 1976). 

 The legislative history also provides a window into the 

scope of the program that Congress anticipated and related 

administrability concerns. According to the Steigerwald-Strelow 

memorandum, the number of new sources each year whose “BACT 

emissions from typical plant” exceed 100 for the 28 listed 

source categories and 250 for all other source categories is 

less than 100 per year. Although the Steigerwald-Strelow 

memorandum does not attempt to estimate the number of 

modifications, it appears that based on this information, 

Congress had reason to expect the total size of the PSD program 

to be measured in the hundreds of permits each year. A program 

of this size would be manageable by EPA and the permitting 

authorities. 

(3) PSD Regulatory History: Regulations Concerning the 

Definition of “Major Stationary Source” 
196

For present purposes, the regulatory history of the PSD 

program is most noteworthy because it shows that since the 

inception of the program following the 1977 CAA Amendments, EPA 

has interpreted the statutory PSD applicability provisions to 

apply more narrowly – to any air pollutant subject to regulation

– than their literal meaning (“any air pollutant”). EPA’s 

initial rulemaking implementing the PSD program, which was 

proposed and finalized in 1977-1978, made explicit that the 

entire PSD program applied to only pollutants regulated under 

the Act. 43 FR 26,380, 26,403/3, 26,406 (June 19, 1978) 

(promulgating 40 CFR 51.21(b)(1)(i)). In 1979-1980, EPA revised 

the PSD program to conform to Alabama Power v. Costle, 636 F.2d 

323 (D.C. Cir. 1980). 44 FR 51,924 (Sept. 5, 1979) (proposed 

rule); 45 FR 52,676 (Aug. 7, 1980) (final rule). In this 

rulemaking, EPA did not disturb the pre-existing provisions that 

limited the applicability of the PSD program to regulated air 
197

pollutants.34 In 1996 EPA proposed, and in 2002 finalized, a set 

of amendments to the PSD provisions that included revisions to 

conform with the 1990 Act Amendments, which, in relevant part, 

exempted hazardous air pollutants from PSD, under CAA § 

112(b)(6). See 61 FR 38,250 (July 23, 1996), 67 FR 80,186 (Dec. 

31, 2002). In the preamble to the final rule, EPA noted that 

based on a request from a commenter, EPA was amending the 

regulations to “clarify which pollutants are covered under the 

PSD program.” EPA accomplished this by promulgating a 

definition for “regulated NSR pollutant,” which listed 

categories of pollutants regulated under the Act, and by 

substituting that defined term for the phrase “pollutants 

regulated under the Act” that was previously used in various 

parts of the PSD regulations. 67 FR at 80,240. The definition 

of “regulated NSR pollutant” includes several categories of 

 34 As noted elsewhere in this notice, in Alabama Power, the 

D.C. Circuit noted that the definition of “major emitting 

facility” under CAA section 169(1) could apply to air pollutants 

not regulated under other provisions of the Act, and discussed 

the contrast of this broad definition to the narrower 

application of the BACT provisions. 636 F.2d at 352-53 & n. 60. 

In its rulemaking notices responding to Alabama Power, EPA 

discussed at length certain issues, such as the applicability of 

NSR to pollutants emitted below the “major” thresholds, that are 

based on the reference in “major emitting facility” to “any air 

pollutant.” However, throughout its discussion, EPA interpreted 

that reference as “any regulated air pollutant,” again without 

specifically acknowledging the difference or without 

acknowledging the above-noted statements in Alabama Power. See

45 FR at 52,710 – 52,711. EPA did not indicate that it had 

received comments on this issue. 
198

pollutants (including, in general, NAAQS pollutants and 

precursors, pollutants regulated under CAA §111 new source 

performance standards, Class I or II substances regulated under 

CAA title VI) and a catch-all category, “[a]ny pollutant that 

otherwise is subject to regulation under the Act.” E.g., 40 CFR 

52.21(b)(50). As in the previous rulemakings, EPA did not 

address the difference between the definition of “major emitting 

facility” and its regulatory approach or indicate that it had 

received comments on this issue. While the definition of “major 

modification” in the PSD regulations has changed over time with 

respect to how emission increases are calculated, the regulatory 

history with respect to pollutant coverage parallels that of 

major emitting facility. 

We recount this regulatory history as background 

information. We are not reconsidering or reopening these 

regulations to the extent they interpret the definition of 

“major emitting facility” and “modification” narrowly to be 

limited to pollutants subject to regulation under the Act. 

b. Title V Program 

Having reviewed the key statutory provisions, their 

legislative history, and the relevant administrative 

interpretations for the PSD program, we now do the same for the 

title V program. 
199

(1) Title V Provisions 

The key title V provisions for present purposes start with 

the applicability provisions, which are found in CAA §§502(a), 

501(2)(B), and 302(j). These provisions provide that it is 

unlawful for any person to operate a "major source" without a 

title V permit, §502(a), and define a "major source" to include 

"any major stationary facility or source of air pollutants which 

directly emits, or has the potential to emit, one hundred tons 

per year or more of any air pollutant." CAA §501(2)(B) and 

§302(j). As noted elsewhere, these provisions, taken together 

and as interpreted by EPA, provide that stationary sources are 

subject to title V if they emit at the 100-tpy threshold air 

pollutants that are subject to EPA regulation. 

In addition, although title V does not have a set of 

provisions describing its purpose, it is clear from its 

provisions and its legislative history, discussed later, that 

its key goal is to gather into one permitting mechanism the CAA 

requirements applicable to a source and impose conditions 

necessary to assure compliance with such requirements, and 

thereby promote the enforceability of CAA requirements 

applicable to the covered sources. CAA §503(b)(1) requires that 

the source’s permit application contain a compliance plan 

describing how the source will ”comply with all applicable 
200

requirements” of the CAA, and §504(a) requires that “[e]ach 

permit issued under [title V] shall include * * * such * * * 

conditions as are necessary to assure compliance with applicable 

requirements of [the Clean Air Act].” See H.R. Rep. No. 101–

490, at 351 (1990) (‘‘It should be emphasized that the operating 

permit to be issued under this title is intended by the 

Administration to be the single document or source of all of the 

requirements under the Act applicable to the source.’’). 

Importantly, title V is replete with provisions designed to 

make the permitting process as efficient and smooth-running as 

possible, including the expeditious processing of permit 

applications and the timely issuance of permits. CAA §503(c) 

requires that “the permitting authority shall approve or 

disapprove a completed application * * * and shall issue or deny 

the permit, within 18 months after the date of receipt thereof * 

* * *” CAA §502(b)(6) requires the permitting authority to 

develop “adequate, streamlined, and reasonable procedures for 

expeditiously determining when applications are complete, for 

processing such applications, for public notice * * * and for 

expeditious review of permit actions, including * * * judicial 

review in State court of the final permit action by [specified 

persons].” CAA §502(b)(7) includes a “hammer” provision 
201

designed to reinforce timely permit issuance, which is that the 

permitting authority’s program must include: 

To ensure against unreasonable delay by the permitting 

authority, adequate authority and procedures to 

provide that a failure of such permitting authority to 

act on a permit application or permit renewal 

application (in accordance with the time periods 

specified in [CAA §503] * * *) shall be treated as a 

final permit action solely for purposes of obtaining 

judicial review in State court of an action brought by 

any person referred to in paragraph (6) to require 

that action be taken by the permitting authority on 

such application without additional delay. 

CAA §502(b)(8) requires the permit program to include 

“[a]uthority and reasonable procedures consistent with the need 

for expeditious action by the permitting authority on permit 

applications and related matters, to make available to the 

public [certain permit-related documents]”. CAA §502(b)(9) 

requires a permit revision to incorporate requirements 

promulgated after issuance of the permit, but only if the permit 

is for a major source and has a term of 3 or more years 

remaining. In addition, the revision must occur “as 

expeditiously as practicable.” CAA §502(b)(10) requires the 

permit program to include operational flexibility provisions 

that “allow changes within a permitted facility . . . without 

requiring a permit revision, if the changes are not 

modifications . . . and . . . do not exceed the emissions 

allowable under the permit. . . .” 
202

In addition, title V includes a comprehensive and finely 

detailed implementation schedule that mandates timely issuance 

of permits while building in EPA and affected state review, 

public participation, and timely compliance by the source with 

reporting requirements. Following the date that sources become 

subject to title V, they have 1 year to submit their permit 

applications. CAA §503(c). As noted previously, the permitting 

authority then has 18 months to issue or deny the permit. CAA 

§503(c). Permitting authorities must provide an opportunity for 

public comment and a hearing. CAA §502(b)(6). If the 

permitting authority proposes to issue the permit, the 

permitting authority must submit the permit to EPA, and notify 

affected states, for review. CAA §505(a)(1). EPA then has 45 

days to review the permit and, if EPA deems it appropriate, to 

object to the permit. CAA §505(b)(1). If EPA does object, then 

the permitting authority must, within 90 days, revise it to meet 

the objections, or else EPA becomes required to issue or deny 

the permit. CAA §505(c). If EPA does not object, then, within 

60 days of the close of the 45-day review period, any person may 

petition EPA to object, and EPA must grant or deny the petition 

within 60 days. CAA §505(b)(2). If a permit is issued, it must 

include a permit compliance plan, under which the permittee must 

“submit progress reports to the permitting authority no less 
203

frequently than every 6 months,” and must “periodically (but no 

less frequently than annually) certify that the facility is in 

compliance with any applicable requirements of the permit, and 

[] promptly report any deviations from permit requirements to 

the permitting authority.” CAA §503(b). 

(2) Title V Legislative History 

(a) Scope of Title V 

The legislative history of title V, enacted by Congress in 

the 1990 CAA Amendments, indicates the scope of the program that 

Congress expected: Congress expected the program to cover some 

tens of thousands of sources, which would approximate the scope 

of the permit program under the Clean Water Act. The Senate 

Committee on Environment and Public Works stated: 

EPA estimates that the new permit requirements will 

cover about 8,200 major sources that emit 100 tons per 

year or more of criteria pollutants (which are 

regulated under SIPs). In addition, many smaller 

sources are (or, as EPA promulgates additional 

regulations, will be) covered by new source 

performance standards under section 111 of the Act, 

hazardous air pollutant standards under section 112 of 

Act, and nonattainment provisions of this legislation. 

By comparison, under the Clean Water Act, some 70,000 

sources receive permits, including more than 16,000 

major sources. Although many air pollution sources 

have more emission points than water pollution 

sources, the additional workload in managing the air 

pollution permit system is estimated to be roughly 

comparable to the burden that States and EPA have 

successfully managed under the Clean Water Act. 
204

S. Rep. 101–228, at 353 (1990).35 Sen. Mitchell, the Senate 

Majority Leader, stated that he expected “over 10,000 permits 

[to] . . . be issued under this program.” 136 Cong. Rec. S3239-

03 (March 27, 1990). Others in Congress had similar estimates. 

See, e.g., 136 Cong. Rec. S3166 (“thousands and thousands of 

permit applications ... will be required to be submitted”) 

(statement of Sen. Nickles). 

Furthermore, the legislative history indicates that 

Congress did not contemplate that large numbers of very small 

sources would be subject to title V’s requirements. This 

becomes clear by reviewing the legislative history of a 

companion piece of legislation to the operating permits 

provisions that Congress enacted into CAA section 507, which is 

the “Small business stationary source technical and 

environmental compliance assistance program.” CAA section 507. 

Under this provision, sources that, among other things, “are not 

[] major stationary source[s]” and that emit less than 50 tpy of 

any regulated pollutant, as well as less than 75 tpy or all 

regulated pollutants, are eligible for assistance under CAA 

section 507. CAA section 507(c)(1). The House Committee Report 

described this provision – including what types of sources it 

 35 The House Committee on Energy and Commerce acknowledged 

that it was “uncertain about the magnitude of permit 

applications likely to be submitted under the bill initially and 

thereafter in each State or to EPA,” H. Rep. 101-490 p. 346. 
205

expected this provision to benefit -- as follows: 

New section [507] is a small source/small 

business provision added by the Committee. It seeks 

to help small businesses to comply with the problems 

that are likely to occur under the Act as amended by 

this bill. For purposes of this section, small 

businesses or small emitters are defined as sources 

that are emitting 100 tons or less per year and that 

have a number of employees that would qualify them for 

assistance from the Small Business Administration 

(SBA). As we look to the future of environmental 

protection under the Act, we take special steps here 

to ensure that it is possible for these small 

businesses to comply with minimum hassle and in 

recognition of the problems that are unique to them. 

Such small businesses include printers, furniture 

makers, dry cleaners, and millions of other small 

businesses in this country. 

House Committee Report, H.R. 101-590, at 354. In this manner, 

the House Committee Report made clear that it expected “millions 

of ... small businesses” -- including “printers, furniture makers, 

dry cleaners” and many others -- to benefit from the CAA section 

507 small source/small business program, but Congress did not 

expect them to become subject to the operating permit 

requirements of title V because their emissions fell below 100 

tpy, which is, in general, the threshold for title V 

applicability. 

The legislative history of title V confirms that Congress 

viewed a principal purpose of title V as providing a vehicle to 

compile the requirements applicable to the source. As the 

report of the House Committee on Energy and Commerce (“House 
206

Committee Report”) stated, ‘‘It should be emphasized that the 

operating permit to be issued under this title is intended by 

the Administration to be the single document or source of all of 

the requirements under the Act applicable to the source.” H.R. 

Rep. No. 101–490, at 351 (1990). Combined with the source’s 

reporting requirements, this compilation of applicable 

requirements would facilitate public awareness of a source’s 

obligations and compliance and would facilitate compliance and 

enforcement. 

On the Senate side, Sen. Chafee, one of the floor managers 

of the bill, made a similar point: 

The permits will serve the very useful function 

of gathering and reciting in one place -- the permit 

document itself -- all of the duties imposed by the 

Clean Air Act upon the source that holds the permit. 

This would clearly be an improvement over the present 

system, where both the source and EPA must search 

through numerous provisions of state implementation 

plans and regulations to assemble a complete list of 

requirements that apply to any particular plant.... 

Once these permits are in place, plant managers 

will be better able to understand and to follow the 

requirements of the Clean Air Act. At the same time, 

EPA will be better able to monitor how well each plant 

is complying with those requirements. This is a 

highly sensible approach for all concerned. 

136 Cong. Rec. S213 (January 24, 1990) (statement of Sen. 

Chafee). Sen. Lieberman made a similar statement. 136 Cong. 

Rec. 3172-73 (March 26, 1990) (statement of Sen. Lieberman). 

Thus, a central purpose of the title V permit program is to 
207

compile all the requirements applicable to the source into a 

single place, the permit. Implicit in this purpose is that the 

sources subject to title V will have applicable requirements to 

be compiled. As Sen. Chafee directly stated, “[T]he vast 

majority of these permit applications will ... , in all 

likelihood, only codify the existing requirements of the 

applicable State implementation plan.” 136 Cong. Rec. S2720 

(March 20, 1990) (statement of Sen. Chafee). 

More broadly, the legislative history also indicates 

congressional concern about the costs of permitting for small 

businesses, and a determination to minimize those costs to the 

extent possible. This concern is reflected in several 

provisions of title V. For example, section 502(a) authorizes 

EPA to exempt all or part of a source category – except for any 

major source -- from the title V permit program if EPA “finds 

that compliance with [title V] requirements is impracticable, 

infeasible, or unnecessarily burdensome on such categories.” 

Similarly, the permit fee provisions include a presumptive 

minimum fee amount, but authorize an exemption from that 

presumptive amount upon a showing that a lesser amount will meet 

overall fee requirements, CAA section 502(b)(3)(B)(iv). One of 

the drafters of this provision, Rep. Wyden, explained that its 

purpose was to preserve the flexibility of states to impose 
208

lower fees of small businesses: 

I note that the provision on fees allows 

reductions for small sources where appropriate. The 

state has some flexibility, under the general permit 

fee provisions, to adjust fee levels for any source so 

long as the average fee charged meets the statutory 

minimum. 

136 Cong. Rec. H12884 (Oct. 26, 1990) (statement of Rep. Wyden). 

See e.g., 136 Cong. Rec. H2559 (May 21, 1990) (statement of 

Rep. Wyden) (discussing need to “help small businesses through 

the air permit labyrinth”). 

 The legislative history also indicates that Congress was 

deeply concerned both about the need not to burden sources 

generally with undue costs and to assure the administrability of 

the title V program, and as a result, was determined to make the 

program as smooth-running as possible. These goals are 

reflected in many of the title V requirements, as discussed 

previously. See, e.g., CAA §502(b)(6) (requiring “adequate, 

streamlined, and reasonable procedures for expeditiously 

determining when applications are complete, for processing such 

applications, for public notice * * * and for expeditious review 

of permit actions); CAA §502(b)(7) (includes a “hammer” 

provision designed to reinforce timely permit issuance); CAA 

§502(b)(9)-(10) (limiting circumstances under which permit 

revision is required; requiring revision to occur “as 
209

expeditiously as practicable;” including operational flexibility 

provisions). 

The legislative history confirms that these provisions were 

designed to reduce costs to sources and promote 

administrability. The “Chafee-Baucus Statement of Senate 

Managers” for the bill explained the purpose of the CAA section 

502(b)(6) requirement for “[a]dequate, streamlined, and 

reasonable procedures for expeditious[]” permit actions as 

follows: 

[M]uch concern has been expressed that this new 

permitting process will unduly delay the proper 

functioning of many sources, and we intend to mitigate 

any delay by directing that the process be 

expeditious. 

 In addition to this general directive for expeditious 

processing, we mandate in new section 503 that 

permitting authorities approve or reject permit 

applications within certain specified time periods 

following filing. In this fashion, we have taken 

explicit steps to protect against undue delays. 

136 Cong. Rec. S16941 (statement of Sen. Chafee). The same 

statement explained that the permit revision procedures of CAA 

section 502(b)(9) reflect a – 

careful effort to ensure that the permit program works 

effectively and efficiently. Succinctly, this 

provision accommodates two competing concerns. On the 

one hand, it is important to ensure that permit 

requirements remain up-to-date as the provisions of 

the Clean Air Act are developed and new requirements 

are imposed. On the other hand, it also is important 

to be sure that we do not reduce the permit program to 

a shambles by requiring sources to engage in a 
210

continuous process of revising their permits as these 

new requirements are imposed. 

136 Cong. Rec. 16942 (Oct. 27, 1990) (Chafee-Baucus 

statement of Senate Managers) (statement of Sen. Chafee). 

 In addition, these concerns were at the bottom of the 

following statement by Sen. Chafee, in which he described how 

the bill’s drafters had revised it in response to a concern by 

industry that an earlier version of the bill would have put 

undue costs on industry: 

We have also heard concerns from industry that S. 

1630 would burden sources unduly by requiring them to 

submit-along with their permit applications-plans 

explaining how they intend to comply with all 

requirements of the Clean Air Act that apply to them. 

But, Mr. President, we emphatically do not intend 

to burden industry with preparation and submission of 

unnecessary compliance plans. The substitute 

clarifies that any compliance plans would address only 

those matters by which the sources would comply with 

new requirements imposed by this act as it is finally 

signed into law. These plans would not need to 

address compliance with any existing Clean Air Act 

requirements, unless the source is in violation of 

those requirements. 

136 Cong. Rec. S2107 (March 5, 1990) (statement of Sen. Chafee). 

As another indication of congressional concern over 

administrability, Congress recognized that at the beginning of 

the program, large numbers of permit applications might 

overwhelm the permitting authorities. To protect against this, 

Congress included in CAA section 503(c) a phase-in schedule for 
211

permitting authorities to act on the initial set of permit 

applications. Under 503(c), permitting authorities were not 

required to act on the initial set of permit applications within 

18 months after it received the application, but rather could 

act on one-third of them on an annual basis over a 3-year 

period. Sen. Chafee, in describing an early version of this 

provision – which would have allowed permitting authorities to 

phase-in the submission of permit applications – explained that 

its purpose was “to avoid a logjam of permit applications[,] ... 

ensure that [regulatory] gridlock can be avoided, and [ensure] 

that the permitting process will work with a minimum of 

disruption and delay.” 136 Cong. Rec., S2106 (March 5, 1990) 

(statement of Sen. Chafee). 

(3) Title V Regulatory History 

 

 As with PSD, for present purposes, the regulatory history 

of the title V program is most noteworthy because it shows that 

beginning shortly after the inception of the program following 

the 1990 CAA Amendments, EPA has interpreted the statutory title 

V applicability provisions to apply more narrowly – to any air 

pollutant subject to regulation – than their literal meaning 

(“any air pollutant”). As discussed previously, title V applies 

to any “major source,” defined, as relevant here, under CAA 

sections 501(2)(B) and 302(j), as “any stationary facility or 
212

source of air pollutants which directly emits, or has the 

potential to emit, one hundred tons per year or more of any air 

pollutant....” EPA’s regulations mirror the CAA definitional 

provisions. 40 CFR 70.2. 

 However, since 1993, EPA has interpreted the applicability 

provisions more narrowly. At that time, which was shortly after 

title V was enacted, EPA issued a guidance document making clear 

that it interprets this requirement to apply to sources of 

pollutants “subject to regulation” under the Act. Memorandum 

from Lydia N. Wegman, Deputy Director, Office of Air Quality 

Planning and Standards, U.S. EPA, “Definition of Regulated Air 

Pollutant for Purposes of Title V” (Apr. 26, 1993) (Wegman 

Memorandum). The interpretation in this memorandum was based 

on: (1) EPA’s reading of the definitional chain for “major 

source” under title V, including the definition of “air 

pollutant” under section 302(g) and the definition of “major 

source” under 302(j); (2) the view that Congress did not intend 

to require a variety of sources to obtain title V permits if 

they are not otherwise regulated under the Act (see also CAA 

section 504(a), providing that title V permits are to include 

and assure compliance with applicable requirements under the 

Act); and (3) consistency with the approach under the PSD 

program. 
213

While the specific narrow interpretation in the Wegman 

Memorandum of the definition of “air pollutant” in CAA section 

302(g) is in question in light of the holding in the 

Massachusetts case (finding this definition to be “capacious,” 

Massachusetts v. EPA, 549 U.S. 497, 533 (2077)), EPA believes 

that its overall rationale for its interpretation of the 

applicability of title V remains sound. EPA continues to 

maintain its interpretation, consistent with CAA sections 

302(j), 501, 502 and 504(a), that the provisions governing title 

V applicability for “a major stationary source” can only be 

triggered by emissions of pollutants subject to regulation. 

This interpretation is based primarily on the purpose of title V 

to collect all regulatory requirements applicable to a source 

and to assure compliance with such requirements, see, e.g., CAA 

section 504(a), and on the desire to promote consistency with 

the approach under the PSD program. 

 In the Tailoring Rule notice of proposed rulemaking, EPA 

acknowledged the Wegman Memorandum and affirmed the memorandum’s 

continued viability, stating that “EPA continues to maintain 

this interpretation.” 74 FR 55,300, col. 3, fn. 8; see also 75 

FR at 17022-23 (Interpretive Memorandum Reconsideration). 

As with PSD, we recount this regulatory history as 

background information, and we are not reconsidering or re-
214

opening this interpretation of the definition of “major source” 

narrowly to be limited to pollutants subject to regulation under 

the Act. 

5. Application of the “Absurd Results” Doctrine for the PSD 

Program 

Having reviewed the factual background, legal doctrines, 

and the key components of the PSD and title V programs, we now 

turn towards interpreting the PSD and title V requirements in 

accordance with the Chevron framework, accounting for the 

applicable legal doctrines. We begin with the “absurd results” 

doctrine, and apply it first to the PSD requirements. 

In this action, we finalize, with some refinements, the 

“absurd results” basis we proposed. Specifically, we are 

revising our regulations to limit PSD applicability to GHG 

emitting sources by revising the regulatory term, “regulated NSR 

pollutant,” and although our revised regulations do not accord 

with a literal reading of the statutory provisions for PSD 

applicability, which are incorporated into the definition of 

“major emitting facility” and “major modification,” we have 

concluded that based on the “absurd results” doctrine, a literal 

adherence to the terms of these definitions is not required. A 

literal adherence would not reflect congressional intent that 

PSD apply to GHG sources as a general matter. Further, we may 
215

apply PSD to GHG sources in a phased-in manner, as we do through 

the tailoring approach, because either congressional intent is 

clear on that issue and the tailoring approach best reflects it, 

or congressional intent is unclear and the tailoring approach is 

a reasonable interpretation of the statute. However, in this 

rulemaking, it is not necessary to make decisions, and we do not 

do so, about congressional intent for applying PSD to smaller 

GHG sources, that is, those that emit at or close to the 

statutory thresholds. 

a. Congressional Purpose for the PSD Program 

To reiterate, for convenience, CAA §169(1) defines a “major 

emitting facility” to include “any ... source[] [that] emit[s], or 

ha[s] the potential to emit, [depending on the source category], 

one hundred [or two hundred fifty] tons per year or more or more 

of any air pollutant.” CAA § 169(1); and a “modification” as 

any physical or operational change in “a stationary source which 

increases the amount of any air pollutant emitted by such 

source,” CAA § 169(2)(C), 111(a)(4). We also reiterate that, as 

discussed above, beginning with our initial rulemaking in 1977-

1978 to implement the PSD program, we have interpreted these 

definitions more narrowly by reading into them the limitation 

that a source is subject to PSD only if the air pollutants in 

question are “subject to regulation under the Act.” 
216

51.166(b)(49)(iv). EPA is not re-opening this interpretation in 

this regulation in this action. 

Under the current interpretation of the PSD applicability 

provision, EPA’s recent promulgation of the light-duty vehicle 

rule will trigger the applicability of PSD for GHG sources at 

the 100/250 tpy threshold levels as of January 2, 2011. This is 

because PSD applicability hinges on the definition of “major 

emitting facility,” which, under EPA’s long-standing narrowing 

interpretation, but absent further tailoring, applies PSD to 

sources of any air pollutant subject that is subject to 

regulation under another provision of the CAA. EPA’s 

promulgation of the light-duty vehicle rule means that GHGs will 

become subject to regulation on the date that the rule takes 

effect, which will be January 2, 2011. 

But absent tailoring, the January 2, 2011 trigger date for 

GHG PSD applicability will subject an extraordinarily large 

number of sources, more than 81,000, to PSD each year, an 

increase of almost 300-fold. And the great majority of these 

new sources will be small commercial or residential sources. We 

believe that for many reasons, this result is contrary to 

congressional intent for the PSD program, and in fact would 

severely undermine what Congress sought to accomplish with the 

program. As a result, under our Chevron analysis, accounting 
217

for the “absurd results” doctrine, the statutory definition for 

“major emitting facility” (as interpreted narrowly to include 

“subject to regulation”) should not be read to apply to all GHG 

sources at or above the 100/250 tpy threshold as of the January 

2, 2011 date. Rather, the definitions of “major emitting 

facility” and “modification” should be tailored so that they 

applies to GHG sources on a phased-in basis, with the largest 

sources first, as we describe in this rule. 

As explained previously, Chevron step 1 calls for a 

determination of congressional intent, and the courts consider 

the best indicator of congressional intent to be the plain 

meaning of the statute. However, the United States Supreme 

Court has held that the literal meaning of a statutory provision 

is not conclusive “in the ‘rare cases [in which] the literal 

application of a statute will produce a result demonstrably at 

odds with the intentions of the drafters’ ... [in which case] the 

intention of the drafters, rather than the strict language, 

controls.” United States v. Ron Pair Enterprises, 489 U.S. 235, 

242 (1989). To determine whether “the intentions of the . . . 

drafters” differ from the result produced from “literal 

application” of the statutory provisions in question, the courts 

may examine the overall context of the statutory provisions, 

including whether there are related statutory provisions that 
218

either conflict or are consistent with that interpretation; and 

the legislative history to see if it exposes what the 

legislature meant by the terms in question. In addition, the 

courts may examine whether a literal application of the 

provisions produces a result that the courts characterize 

variously as absurd, futile, strange, or indeterminate, and 

therefore so illogical or otherwise contrary to sensible public 

policy as to be beyond anything Congress would reasonably have 

intended. In such cases, the literal language cannot be said to 

reflect the intention of the drafters, and therefore does not 

control. See United States v. Ron Pair Enterprises, 489 U.S. 

235, 242-43 (1989); Griffin v. Oceanic Contractors, Inc., 458

U.S. 564, 571 (1982). 

Here, applying the definitions of “major emitting facility” 

and “modification” without tailoring – that is, applying PSD to 

GHG sources at the 100/250 tpy level and applying the 

modification provisions by their terms without tailoring -- 

would be contrary to congressional purpose for the PSD 

provisions, as found in the statutory provisions and legislative 

history, especially in light of the impact from applying PSD to 

those sources. Congress established the PSD program in large 

measure because it was concerned that around the country, 

industrial development, which was confronting barriers to 
219

locating in nonattainment areas (that is, areas that do not meet 

the NAAQS), would attempt to locate in clean air areas (that is, 

attainment areas or unclassifiable areas), but that as a 

consequence, the clean air areas would see their air quality 

deteriorate to the point where they, too, would no longer meet 

the NAAQS. The end result would be the spread of environmental 

and health problems to those formerly clean air areas, as well 

as more barriers to further industrial development. With these 

concerns in mind, Congress designed the PSD program to require 

newly constructing or modifying sources in areas with air 

quality that meets the NAAQS (or that is unclassifiable) to 

analyze their emissions of NAAQS pollutants and to implement 

controls as needed to assure that those emissions do not 

significantly deteriorate air quality. Many of the PSD 

requirements, and much of the discussion in the legislative 

history, reflect these aspects of the PSD program. E.g., CAA 

sections 162, 163, 164, 165(a)(3), 165(d)(2), 165(e), 166; see 

generally H. Rep. 95-294, 95th Cong., 1st Sess. (1977) 103-78. 

Congress also designed the PSD program to impose controls 

on non-NAAQS pollutants, through the requirement under CAA 

section 165(a)(4) that the source be “subject to the best 

available control technology [(“BACT”)]for each pollutant 

subject to regulation under this chapter emitted from, or which 
220

results from, such facility.” For example, when Congress 

enacted the PSD provisions in 1977, sources emitting HAPs were 

required to implement BACT for those pollutants, although in the 

1990 CAA Amendments, Congress redesigned CAA section 112, which 

includes the requirements for HAPs, and excluded HAPs from PSD. 

CAA § 112(b)(6). 

Congress was keenly aware that the PSD program needed to 

serve two purposes: protect the environment and promote 

economic growth. Congress explicitly identified these two goals 

in the “purposes” section of the PSD provision, CAA § 160, and 

various PSD requirements clearly reflect them. For example, to 

protect economic growth, the PSD program expedites the permit 

process to include a 1-year limitation on the time that the 

permitting authority has act on permit applications. To protect 

the environment, in addition to including many provisions that 

focus on NAAQS pollutants, the PSD program requires that the 

preconstruction permit impose emission limits that reflect BACT 

for each pollutant subject to regulation under another CAA 

provision. CAA section 165(a)(4). This BACT provision also 

makes clear, by its terms, that although Congress designed the 

PSD program primarily with NAAQS pollutants in mind, Congress 

also intended that sources subject to PSD control the emissions 

of their other pollutants as well. The D.C. Circuit has 
221

recognized the twin goals of environmental protection and 

economic development that underlie PSD, and has upheld EPA 

interpretations of the PSD program that reflect a balancing of 

those goals. See, e.g., New York v. EPA, 413 F.3d 3, 27 (D.C. 

Cir.), rehearing en banc den. 431 F.3d 801 (2005). 

Congress was also keenly aware that the PSD analyses and 

controls that it was mandating had to be implemented on a 

source-by-source basis, and that this process would be expensive 

for sources. As a result, Congress intended to limit the PSD 

program to large industrial sources because it was those sources 

that were the primary cause of the pollution problems in 

question and because those sources would have the resources to 

comply with the PSD requirements. Congress’s mechanism for 

limiting PSD was the 100/250 tpy threshold limitations. Focused 

as it was primarily on NAAQS pollutants, Congress considered 

sources that emit NAAQS pollutants in those quantities generally 

to be the large industrial sources to which it intended PSD be 

limited. 

That Congress paid careful attention to the types and sizes 

of sources that would be subject to the PSD program and designed 

the thresholds deliberately to limit the program’s scope is 

evident from the legislative history. Several Senate floor 

statements and the Committee Report made clear in their 
222

insistence that PSD should not apply to small sources. As 

discussed later, Congress scrutinized information that EPA 

provided as to types and sizes of sources, found largely in the 

Steigerwald-Strelow memorandum. Sen. McClure stated that the 

Senate bill excluded “houses, dairies, farms, highways, 

hospitals, schools, grocery stores, and other such sources.” 

123 Cong. Rec. 18021 (June 8, 1977) (statement of Sen. Muskie). 

Sen. McClure stated that PSD should be limited to “industrial 

plants of significant impact,” and should exclude ”[a] small 

gasoline jobber, or a heating plant at a community college, 

[which] could have the potential to emit 100 tons of pollution 

annually.” 122 Cong. Rec. 24548-49 (July 29, 1976) (statement 

of Sen. McClure). The Senate Committee Report mirrored Sen. 

McClure’s statement, and concisely articulated the cost-related 

basis for the line-drawing: “[The PSD] procedure ... must include 

an effective review-and-permit process. Such a process is 

reasonable and necessary for very large sources, such as new 

electrical generating plants or new steel mills. But the 

procedure would prove costly and potentially unreasonable if 

imposed on construction of storage facilities for a small 

gasoline jobber or on the construction of a new heating plant at 

a junior college, each of which may have the potential to emit 

100 tons of pollution annually.” S. Rpt. 95-127 at 96-97. 
223

The D.C. Circuit had occasion, in Alabama Power, to 

acknowledge this legislative history. "Congress's intention was 

to identify facilities which, due to their size, are financially 

able to bear the substantial regulatory costs imposed by the PSD 

provisions and which, as a group, are primarily responsible for 

emissions of the deleterious pollutants that befoul our nation's 

air." Alabama Power, 636 F.2d at 353. The Court added, “Though 

the costs of compliance with [the PSD] requirements are 

substantial, they can reasonably be borne by facilities that 

actually emit, or would actually emit when operating at full 

capacity, the large tonnage thresholds specified in section 

169(1).”. Id. at 354. 

It is not too much to say that applying PSD requirements to 

GHG sources without tailoring the definition of “major emitting 

facility” would result in a program that would have been 

unrecognizable to the Congress that designed PSD. Congress 

intended that PSD be limited to a relatively small number of 

large industrial sources. Without tailoring – that is, without 

phasing in PSD and title V applicability to GHG sources so as to 

allow the development of streamlining methods and increases in 

permitting authority resources -- the PSD program would expand 

by January 2, 2011 from the current 280 sources per year to 

almost 82,000 sources, virtually all of which would be smaller 
224

than the sources currently in the PSD program and most of which 

would be small commercial and residential sources. Until EPA 

could develop streamlining methods, all of the sources that 

would become newly subject to PSD – whether they be larger or 

smaller sources, whether industrial or commercial/residential 

sources -- would have to undergo source-specific BACT 

determinations for their GHG emissions, as well as their 

emissions of conventional pollutants in amounts in excess of the 

significance levels. We estimate that the commercial and 

residential sources – the great majority of which are small 

business -- would each incur, on average, almost $60,000 in PSD 

permitting expenses. This result would be anathema to 

Congress’s careful efforts to confine PSD to large industrial 

sources. 

 A closer look at the legislative history confirms the view 

that sweeping in large numbers of small commercial and 

residential sources is precisely what Congress thought it was 

avoiding by establishing the 100/250 tpy thresholds. As noted 

previously, Congress relied on an EPA memorandum – the 

Steigerwald-Strelow memorandum -- that identified the range of 

industrial categories that EPA regulated under its program that 

constituted the precursor to the statutory PSD program, and 

listed both the estimated number of new sources constructing 
225

each year and the amount of pollution emitted by the “typical 

plant” in the category. The Steigerwald-Strelow memorandum 

makes clear that the 100 tpy cut-off for the 28 listed sources 

categories, and the 250 tpy cut-off for all other sources, would 

exclude from PSD a large number of sources. 122 Cong. Rec.

24548-50 (July 29, 1976). However, virtually all, if not all, 

of the sources in half the 28 source categories emit carbon 

dioxide in quantities that equal or exceed the 100 tpy 

threshold, and almost all of the sources in the remaining 

categories emit CO2 in quantities that equal or exceed the 100 

tpy threshold. Therefore, applying the “major emitting 

facility” definition to GHG sources, without tailoring, would, 

as a practical matter, vitiate much of the purpose of the 100 
226

tpy cut-off for industrial sources.36

Most telling, in this regard, is the small-sized boilers, 

which the Steigerwald-Strelow memorandum describes, in terms of 

size, pollutants emitted, and numbers of sources, as follows: 

The memorandum identified two categories of these boilers, 

differentiated by size. The first ranges in size from 10 to 250 

x 106 Btu/hr, and has a “typical plant” size of 107 Btu/hr, with 

“BACT emissions from typical plant” of 53 tpy, and a total of 

1,446 sources in that category. The second category ranges in 

size from 0.3 to 10 x 106

 Btu/hr, and has a “typical plant” size 

of 1.3 x x 106

 Btu/hr, with “BACT emissions from typical plant” 

of 2 tpy, and a total of 11,215 sources in the category. That 

 

36 Specifically, of the 28 source categories under CAA 

section 169(1), information available to EPA indicates that all 

of the sources in the following categories emit at least 100 tpy 

of CO2 annually: fossil-fuel fired steam electric plants of more 

than 250 million Btu per hour heat input, Portland Cement 

plants, primary zinc smelters, iron and steel mill plants, 

primary aluminum ore reduction plants, municipal incinerators 

capable of charging more than 50 tons of refuse per day, nitric 

acid plants, petroleum refineries, lime plants, primary lead 

smelters, fossil-fuel boilers of more than 250 Btus per hour 

heat input. In addition, all but a few kraft pulp mills and 

glass fiber processing plants emit at least 100 tpy CO2 annually. 

Our information is incomplete with respect to the remaining 

source categories, but with the possible exception of petroleum 

storage and transfer facilities with a capacity exceeding three 

hundred thousand barrels, we suspect that all but at most a few 

sources emit at least 100 tpy CO2 annually. See "Technical 

Support Document for Greenhouse Gas Emissions Thresholds 

Evaluation"; Office of Air Quality Planning and Standards; March 

29, 2010. 
227

memorandum makes clear that EPA did not believe that sources in 

these two categories – and especially the smallest one – would 

be subject to PSD under a 100 tpy threshold, by stating, 

“Fortunately, most truly small boilers and typical space heating 

operations would not be covered.” 122 Cong. Rec. 24549 (July 

29, 1976). However, these data and conclusions were all based 

on emissions of NAAQS pollutants, the amounts of which placed 

these boilers well below the PSD threshold limitations. In 

general, most boilers of these small sizes are fired with 

natural gas, and a natural gas boiler greater than 0.5 x 106

Btu/hr emits at least 250 tpy CO2. Therefore, if the CO2 

emissions of these small boilers are considered – as would occur 

by applying the definition of “major emitting facility” to GHG 

sources without tailoring -- then most of them would in fact be 

subject to PSD. Again, this result would directly contravene 

Congress’s intention to limit PSD to “industrial plants of 

significant impact.” 122 Cong. Rec. 24548-49 (statement of Sen. 

McClure). 

 Perhaps the most compelling reason why applying the PSD 

program to GHG sources without tailoring, and before the 

development of streamlining methods, would be inconsistent with 

congressional intent, is that the resulting program would prove 

unadministrable. Although the legislative history of the PSD 
228

program does not reveal much explicit congressional focus on 

administrability issues, the Steigerwald-Strelow Memorandum, 

which identifies the source categories and numbers of sources 

that were before Congress as it considered PSD, suggests that 

the program that Congress fashioned could be expected to cover 

at most a few thousand sources each year. This appears to be 

approximately the size of the program that EPA administered 

before the 1977 CAA Amendments, so that it seems reasonable to 

assume that Congress expected the PSD program it enacted to be 

within EPA’s and the states’ administrative capacities. 

 Moreover, the Alabama Power court stressed the importance 

of administrability concerns: Most importantly, the Court held 

that EPA, in interpreting the “modification” provisions that 

apply PSD to physical or operational changes by major emitting 

facilities that “increase[] the amount of any air pollutant 

emitted,” CAA section 111(a)(4), may “exempt from PSD review 

some emission increases on grounds of de minimis or 

administrative necessity,” and went on to state that in 

establishing the exemption thresholds, “[t]he Agency should look 

at the degree of administrative burden posed by enforcement at 

various de minimis threshold levels.” 636 F.2d at 400,405. In 

addition, the Court based its holding that potential-to-emit for 

purposes of the applicability thresholds should be defined as 
229

emissions at full capacity with implementation of control 

equipment, in part on its view that with this definition, the 

number of sources subject to PSD would be manageable: 

Though the costs of compliance with section 165 

requirements are substantial, they can reasonably be 

borne by facilities that actually emit, or would 

actually emit when operating at full capacity, the 

large tonnage thresholds specified in section 169(1). 

The numbers of sources that meet these criteria, as we 

delineate them, are reasonably in line with EPA’s 

administrative capability. 

Alabama Power, 636 F.2d at 354. However, applying PSD to GHG 

sources without tailoring would increase the size of the PSD 

program at least an order of magnitude beyond what Congress 

could have had any reason to expect, which would have been far 

beyond the “administrative capability” that Alabama Power

described EPA as having. 

Beyond this disconnect with congressional expectations, 

what is most important is that the extraordinarily large number 

of permit applications would overwhelm permitting authorities 

and slow their ability to process permit applications to a 

crawl. Our best estimate at present is that permitting 

authorities would need to process almost 82,000 permit 

applications per year, compared to, at most, 800 in the current 

PSD program. The total additional workload, in workhours, for 

PSD permits would be more than 19.5 million more work hours, 

compared to 150,795 work hours for the current PSD program, and 
230

the total additional costs for would be over $1.5 billion, 

compared with $12 million for the current PSD program. 

At proposal, we noted that the states had estimated that 

the influx of permit applications that would result from 

applying the 250 tpy threshold at actual emissions would, 

without additional resources result in permitting delays of 3 

years. In fact, as we noted at proposal, a literal reading of 

the PSD requirements would require their application at the 250 

toy PTE level, which would result in ten times more permit 

applications than were assumed when the states made the 3-year 

estimate. Further, our current estimates of the numbers of 

sources that would be subject to PSD requirements are about 

twice what we estimated at proposal, as described elsewhere. 

Moreover, our estimate of the number of hours that permitting 

authorities would need to process a permit application from a 

source in the commercial or residential sector – which is, by 

far, the largest single sector – is three and one-half times as 

long as we estimated at proposal. And under a literal reading 

of the PSD applicability provisions as applied to GHG sources, 

the permitting authorities would be required to implement a 

program of this size beginning on January 2, 2011, less than 9 

months from now. We received many comments from states and 

industry raising concerns about the cost to sources and 
231

administrative burdens of PSD permitting if the statutory 

threshold were to apply for GHG emissions. One commenter 

estimated a cost of over $5 billion and the dedication of over 

17,000 FTEs to this effort. 

We consider, it difficult to overstate the impact that 

applying PSD requirements literally to GHG sources as of January 

2, 2011, without tailoring, would have on permitting 

authorities, on the PSD program, and, more broadly, on economic 

development. The number of PSD permits that would be required 

from such an approach is so far beyond what has ever been seen 

in that program that it is difficult to develop a meaningful 

picture of what the permitting program would look like, except 

to say that throughout the country, PSD permit issuance would be 

unable to keep up with the flood of incoming applications, 

resulting in delays, at the outset, would be at least a decade 

or longer, and would only grow worse over time as each year, the 

number of new permit applications would exceed permitting 

authority resources for that year. Because PSD is a 

preconstruction program, during this time, tens of thousands of 

sources each year would be prevented from constructing or 

modifying. In fact, it is reasonable to assume that many of 

those sources will be forced altogether to abandon plans to 

construct or modify. This can be expected to be true for 
232

virtually all PSD applicants, from the small commercial and 

residential sources to the large industrial sources. As a 

result, a literal application of the PSD applicability 

provisions to GHG sources would have the effect of a virtual

nationwide construction ban extending for years, with all of the 

adverse effects that this would have on economic development. 

The only possible remedies for this dismal scenario would 

be for permitting authorities to increase their PSD funding by 

over 100-fold, from $12 million to over $1.5 billion, or the 

development by EPA and the permitting authorities of 

streamlining techniques. But it is not possible for permitting 

authorities to increase their funding to those levels or 

anything close to them in the foreseeable future, partly because 

of the sheer magnitude of those levels and partly because of the 

financial challenges that states currently face. And, for the 

reasons discussed later, although streamlining offers genuine 

promise to improve the manageability of the PSD workload, 

streamlining cannot do so in the very near term and, in any 

event, the extent to which it can do so has not yet come into 

focus. 

So clear are at least the broad outlines of this picture 

that EPA did not receive any substantive comments arguing that 

permitting authorities could in fact administer the PSD program 
233

with the applicability requirements applied literally to GHG 

sources beginning in the very near future.37 Every permitting 

authority that addressed this issue in their comments on the 

proposed GHG Tailoring Rule stated unequivocally that it could 

not administer the PSD program at the statutory levels. To cite 

a few examples (each of which considered both the PSD and title 

V programs together): NACAA, which represents air pollution 

control agencies in 53 states and territories, stated it 

“...agrees with the EPA that immediately attempting to implement 

the PSD and title V programs using the statutory thresholds 

meets the test for invoking the administrative necessity and 

absurd results doctrines.” Similarly, the California Air 

Resources Board stated that it “...concurs with the United States. 

EPA that if more appropriate applicability thresholds [as 

opposed to the statutory thresholds] are not set for GHG it will 

not be administratively possible to implement these [the PSD and 

tile V] permitting programs.” All other state and local 

permitting agencies that commented on the proposed tailoring 

provided similar comments that they would not have the adequate 

staff capacity or resources to be able to successfully 

administer their permitting programs with the addition of GHG 

 37 EPA did receive comments that asserted in conclusory 

fashion that permitting authorities could administer the 100/250 

tpy levels. 
234

emission sources at the statutory thresholds for PSD and title 

V. 

It is the many-year delays in permit issuance and the 

consequent chilling of economic development that provide perhaps 

the clearest indication that applying the PSD applicability 

provisions to GHG sources without tailoring produces absurd 

results. These effects would undermine one of Congress’s 

central purposes in establishing the PSD program, which was to 

promote development in clean air areas by large industrial 

sources (as long as they included environmental safeguards). As 

discussed previously, this goal is manifest in the structure of 

the PSD provisions, and Congress even went so far as to make 

this goal explicit in the purposes section of the PSD 

provisions. But even if Congress had not been so clear, it is 

inconceivable that Congress could have intended the PSD program 

to be applied in a way that would cause such damage to the 

national economy. 

Moreover, at the present time, there is little 

environmental benefit in subjecting large numbers of small GHG 

sources to PSD permitting requirements. They represent a 

relatively small share of the GHG inventory and the control 

options available to them, at present, are limited. As a 

result, approaches other than source-by-source permitting 
235

presently offer more promise for generating emissions reductions 

in an efficient manner. These approaches, which may be 

developed through both federal and state efforts, include 

requirements, incentives, and educational outreach to promote 

efficiency improvements to boilers and furnaces and energy 

efficient operations, including, for example, weatherization 

programs. 

 For all these reasons, interpreting the definition of 

“major emitting facility” and “modification” literally -- that 

is, as EPA has interpreted them more narrowly, but without 

tailoring – would produce results that are not be consonant 

with, and, in fact, would severely undermine, Congress’s purpose 

for the PSD program. These results may fairly be characterized 

as the type of absurd results that support our view that the 

literal terms of the PSD applicability provisions do not 

indicate congressional intent for how those provisions should 

applied to GHG sources. 

b. Congressonal Intent for the Applicability Provisions 

(1) Congressional Intent for Whether and How PSD Applies to GHG 

Sources 

Several of the PSD provisions and statements in the 

legislative history are particularly important in determining 

whether and how the PSD program should apply to GHG sources, as 
236

discussed elsewhere: (i) The applicability provisions, under 

CAA section 165(a) and 169(1). These provisions are written 

broadly, and although, as we explain above, they cannot be read 

literally to apply to GHG sources at or above the 100/250 tpy, 

they nevertheless can be read to indicate that directionally, 

Congress intended that PSD be applied inclusively. (ii) The 

various PSD provisions that identify the pollutants subject to 

PSD. Compare, e.g., CAA sections 162, 163, 164, 165(a)(3), 

165(d)(2), 165(e), and 166 (NAAQS pollutants) with CAA 

165(a)(3)(C), 165(a)(4) (other pollutants). These provisions 

indicate that a major purpose of the PSD program is to control 

NAAQS pollutants, but that the program also covers non-NAAQS 

pollutants. (iii) The requirement that permitting authorities 

act on PSD applications within 1 year. CAA section 165(c). 

This provision indicates that Congress anticipated the PSD 

program would be of a size that would allow permitting 

authorities to meet this deadline. (iv) The purpose provision. 

CAA section 160. This provision makes clear that PSD is 

designed both to protect public health and welfare and to 

promote economic growth. (v) In addition, we consider important 

the legislative history indicating the Congress intended PSD to 

apply to large industrial sources because they were the primary 

source of the air pollution problems and they have the resources 
237

to manage the demands of the PSD permitting process; and that, 

by the same token, Congress expected that small sources would 

not be subject to PSD. The legislative history does not 

specifically mention GHG sources. 

Looking at these provisions and the legislative history 

together, we think Congress can be said to have intended that 

the PSD program apply to GHG sources as a general matter. The 

most important indication of congressional intent in this regard 

is the applicability provisions, which provide, in part, that 

PSD applies to (i) “any ... source[ that] emit[s], or ha[s] the 

potential to emit [the specified quantity] of any air 

pollutant,” CAA section 169(1); and (ii) to any such source that 

undertakes a physical or operational change that “increases the 

amount of any air pollutant emitted.” CAA section 169(2)(C), 

111(a)(4). These terms are quite broad, and should be read to 

include GHG sources and GHGs. See Massachusetts v. EPA, 549 

U.S. 497, 533 (2007) (“Because greenhouse gases fit well within 

the Clean Air Act's capacious definition of ‘air pollutant,’ we 

hold that EPA has the statutory authority to regulate the 

emission of such gases from new motor vehicles.”). Moreover, 

including GHG sources – under certain circumstances – is 

consistent with the PSD provisions that refer to other 

pollutants, establish the time-frame for acting on PSD 
238

applications, and establish the overall purpose of the program. 

In addition, including GHG sources – again, under certain 

circumstances -- is consistent with the legislative history that 

PSD be limited to sources that cause a meaningful part of the 

air pollution problem and have the resources to manage the PSD 

requirements. No PSD provision explicitly imposes any 

limitation of PSD to large industrial sources, and Congress’s 

reasoning for focusing on large industrial sources – which was 

that these sources are best suited to handle the resourceintensive analyses required by the PSD program – could extend to 

GHG sources under certain circumstances (that is, large sources 

first, and smaller sources after streamlining methods are 

developed). Similarly, as discussed previously, it is 

reasonable to read into Congress’s intent that the PSD program 

be limited to a size that permitting authorities would be able 

to administer, but it is consistent with that reading to 

recognize that the permitting authorities could take certain 

steps – including adoption of streamlining measures and ramping 

up resources – that would allow them to handle a higher volume 

of permitting. Finally, we find nothing in the PSD provisions 

or legislative history that would indicate congressional intent 

to exclude GHG sources. Accordingly, at present, we believe 

that Congress must be said to have intended an affirmative 
239

response for whether PSD applies to sources of GHGs as a general 

matter. 

As to how PSD applies to GHG sources, although, for reasons 

discussed above, the 100/250 tpy threshold provision, which 

establishes the scope of PSD applicability, should not be read 

as applying literally to GHG sources -- and as a result, the 

applicability provision as a whole cannot be said to have a 

plain meaning as to the scope of coverage of GHG sources -- we 

believe that the applicability provisions and legislative 

history nevertheless indicate a congressional intent for how PSD 

should apply to GHG sources. That is to apply PSD to as many 

sources as possible as quickly as possible, at least to a 

certain point. We believe that this flows logically from the 

inclusive direction of the applicability provision, combined 

with the legislative history that focuses on Congress’s desire 

to include in the PSD program sources that have the resources to 

comply with the requirements and, as the Court in Alabama Power 

recognized, Congress’s concern about administrability. That is, 

at first, PSD may apply to the largest GHG sources because they 

may be expected to have the resources to comply with PSD’s 

requirements and permitting authorities may be expected to 

accommodate those sources; and over time, with streamlining and 

increases in permitting authority resources, PSD may apply to 
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more GHG sources. As discussed later, the tailoring approach is 

consistent with congressional intent in this regard. 

On the other hand, if Congress cannot be said to have 

expressed an intent as to the manner and scope of PSD 

applicability to GHG sources, then, under Chevron step 2, EPA 

may apply a reasonable interpretation of the applicability 

provisions to determine the scope of coverage of GHG sources 

that is consistent with the statutory requirements. The 

Tailoring Rule is a reasonable interpretation under Chevron step 

2. It is consistent with (i) the provisions described above 

concerning which pollutants the PSD provisions cover and the 

timetable for permitting authority action on PSD applications; 

(ii) the purpose provisions of PSD, and the accompanying 

legislative history, because it protects public health and 

welfare without inhibiting economic development; and (iii) the 

legislative history indicating Congress intended that PSD be 

limited to sources that cause a meaningful part of the problem 

and can manage its requirements, because it will expand PSD’s 

applicability only after streamlining methods and greater 

permitting authority resources will allow for such an expansion 

in an orderly manner. 

There is a remaining question about congressional intent 

for the applicability of PSD to GHG sources, and that is whether 
241

Congress expressed an intent as to whether PSD applies to the 

smallest of GHG sources, which are those at or near the 100/250 

tpy statutory thresholds. To answer this question, we must 

consider several things that may point in different directions, 

or that carry significant uncertainty, among them: (i) The 

applicability provisions do include those limits, although, as 

we have described previously, it would be an absurd result to 

impose them at the present time. (ii) The legislative history 

makes clear that Congress did not expect that very small sources 

would be included in the PSD program. (iii) It is difficult to 

foresee the extent of streamlining measures. 

In this action, it is not necessary to come to a decision 

as to whether, under Chevron step 1, Congress intended that PSD 

apply, or not apply, to GHG sources as low as the statutory 

levels, or whether, if Congress expressed no clear intent on 

that question, it is reasonable under Chevron step 2 to apply 

PSD to GHG sources at that level, all within the context of the 

tailoring approach. In this rulemaking, we promulgate steps 

that cover larger sources and we provide that we will not apply 

PSD to sources below the 50,000/50,000 tpy CO2e level for at 

least the first 6 years. Because there is no need to come to 

decisions concerning the smaller sources in this rulemaking, we 

intend to consider them further, along with the legal issues 
242

concerning congressional intent, in the subsequent rulemaking 

that we commit to doing as part of this action. 

(2) Criteria for Establishing Phase-in Schedule 

The specific phase-in schedule under the tailoring approach 

will depend on several things. The first is our progress in 

developing streamlining methods that will render the permitting 

authority workload more manageable by taking some sources off 

the table (through regulations or guidance interpreting 

“potential to emit”), and by allowing for more efficient permit 

processing (through general permits and presumptive BACT). At 

the same time, streamlining techniques will lower permitting 

costs to sources or even eliminate some sources’ obligations to 

obtain permits altogether. The second is the time that 

permitting authorities need to ramp up their resources in an 

orderly and efficient manner to manage the additional workload. 

The third is information we have as to the sources’ abilities to 

meet the requirements of the PSD program and the permitting 

authorities’ ability to process permits in a timely fashion. 

That information will be based on the real-world experience the 

permitting authorities will accumulate as they proceed to 

process permit application for the larger GHG sources. 

Thus, under our present approach, we will develop 

streamlining techniques, we expect the permitting authorities to 
243

ramp up resources in response to the additional demands placed 

upon them in the first two steps, and we will gather real worldinformation about the GHG permitting process; and based on all 

that, we will address expanding the PSD program in a step-bystep fashion to include more sources over time. We intend to 

follow this process to establish both the PSD applicability 

thresholds and, as we describe next, the significance levels. 

(3) Criteria for Establishing Significance Levels38

 The criteria for establishing the significance levels are 

the same as for establishing the “major emitting facility” 

thresholds. As noted previously, under the applicable CAA 

sections, any physical or operational change at a stationary 

source that “increases the amount of any air pollutant emitted 

by such source” or that results in the emission of a new 

pollutant is treated as a “modification” that is subject to PSD 

requirements. Although the CAA, by its terms, treats as an 

“increase[]” any amount of emissions that is greater than zero, 

the D.C. Circuit held in Alabama Power v. Costle that EPA may 

 38 It should be noted that strictly speaking, we do not, in 

our drafting of the regulatory revisions that are part of this 

rulemaking, establish a significance level for GHG emissions 

based on CO2e. Rather, we establish an applicability criteria 

for determining whether GHGs are subject to regulation with 

respect to the particular source. We explain our approach in 

more detail in the Response to Comments document. Throughout 

this preamble, we refer to this action, for convenience, as a 

significance level. 
244

establish a threshold – called the significance level – on de 

minimis grounds for the amount of any particular pollutant that 

may be increased. 636 F.2d at 400. 

Of particular importance, the Court in Alabama Power 

indicated that EPA may rely on administrative considerations to 

establish significance levels. Id. To reiterate, the Court 

held that “EPA does have discretion, in administering the 

statute’s ‘modification’ provision, to exempt from PSD review 

some emission increases on grounds of de minimis or 

administrative necessity.” 636 F.2d at 400. The Court added a 

more detailed exposition of its views in a subsequent part of 

its opinion, where it discussed the BACT provision, under CAA 

section 165(a)(4), and the Court made clear that those views 

applied as well to the “modification” provision. There, the 

Court invalidated an EPA regulation that established a 100- and 

250-tpy exemption from the BACT requirement. Both the BACT 

provision and the modification provision apply by their terms to 

all emissions from a source, but the Court stated that each 

provision must be read to incorporate an exemption based on de 

minimis or administrative considerations, and explained: 

We understand that the application of BACT 

requirements to the emission of all pollutants from a 

new facility, no matter how miniscule some may be, 

could impose severe administrative burdens on EPA, as 

well as severe economic burdens on the construction of 

new facilities. But the proper way to resolve this 
245

difficulty is to define a de minimis standard 

rationally designed to alleviate severe administrative 

burdens, not to extend the statutory 100 or 250-ton 

threshold to a context where Congress clearly did not 

apply it. Just as for the applicability of PSD to 

modifications, the de minimis exemption must be 

designed with the specific administrative burdens and 

specific regulatory context in mind. This the Agency 

has failed to do. We do not hold that 100 tons per 

year necessarily exceeds a permissible de minimis

level; only that the Agency must follow a rational 

approach to determine what level of emission is a de 

minimis amount. 

A rational approach would consider the 

administrative burden with respect to each statutory 

context: what level of emission is de minimis for 

modification, what level de minimis for application of 

BACT. Concerning the application of BACT, a rational 

approach would consider whether the de minimis

threshold should vary depending on the specific 

pollutant and the danger posed by increases in its 

emission. The Agency should look at the degree of 

administrative burden posed by enforcement at various 

de minimis threshold levels. It is relevant that our 

decision requires the Agency, in its evaluation of 

emissions of facilities, to take into account the 

facility's air pollution controls. It may also be 

relevant, though it is certainly not controlling, that 

Congress made a judgment in the Act that new 

facilities emitting less than 100 or 250 tons per year 

are not sizeable enough to warrant PSD review. 

Id. at 405. As just quoted, the Court acknowledged the 100 and 

250 tpy thresholds for a major emitting facility, and did not 

indicate whether the modification exemption level could exceed 

those statutory levels, but nevertheless, the Court made clear 

that EPA may “consider the administrative burden” associated 
246

with modifications to establish an exemption level for 

modifications. 

EPA has established significance levels for various 

pollutants, generally relying on a de minimis basis. See, e.g., 

45 FR 52,676, 52,705 – 52,710 (August 7, 1980). In these 

actions, EPA generally established the level based on the 

triviality of the amount of emissions excluded. To this point, 

we have not attempted to determine de minimis – that is, trivial 

-- levels for GHGs. Instead, in this rulemaking, EPA is 

establishing a phase-in schedule for significance levels based 

on the Chevron framework, accounting for the “absurd results,” 

“administrative necessity,” and “one-step-at-a-time” doctrines. 

It is not necessary to establish a permanent de minimis level in 

this rulemaking. For one thing, the Court in Alabama Power

explicitly authorized an administrative basis for significance 

levels. Moreover, were EPA to establish a de minimis level, 

that amount could be below – perhaps even well below – the 

“major emitting facility” thresholds established in this 

rulemaking on grounds of “administrative necessity” and the 

other doctrines. Accordingly, at present, if we were to 

establish a permanent significance level on a de minimis basis, 

that level could result in too many small sources being required 

to submit permit applications while the phase-in is occurring. 
247

This would give rise to the same problems concerning undue costs 

to the sources and administrative burdens for the permitting 

authorities for which we are fashioning a remedy. Accordingly, 

the significance levels we establish with this action are the 

lowest levels that sources and permitting authorities can 

reasonably be expected to implement at the present time in light 

of the costs to the sources and the administrative burdens to 

the permitting authorities. 

c. Other Possible Approaches to Reconciling Literal Reading of 

PSD Applicability Provisions and Congressional Intent 

Commenters have suggested another approach to reconciling 

the inconsistency between the definition of “major emitting 

facility” and congressional intent. They urge that the “major 

emitting facility” definition should be applied so that only 

sources that emit NAAQS pollutants, for which the area is 

designated attainment or unclassifiable, in the requisite 

quantities would be subject to PSD, and sources would not be 

subject to PSD based solely on their emissions of non-NAAQS 

pollutants or a NAAQS pollutant for which an area has been 

designated nonattainment. Some commenters argue that this 

approach is mandated by several of the PSD provisions, read 

together or at least that the relevant statutory provisions are 

ambiguous and that this approach is a reasonable reading of 
248

them. Under this approach, we would not need to phase in the 

application of PSD by lowering the applicability threshold for 

GHG emitters. 

Specifically, many commenters have questioned whether EPA 

has the authority to regulate GHGs under the PSD provisions. 

Although the specific lines of reasoning vary somewhat from one 

commenter to another, in general, they based their arguments 

largely on CAA sections 161 and 165(a). Under CAA section 161: 

In accordance with the policy of section 101(b)(1), 

each applicable implementation plan shall contain 

emission limitations and such other measures as may be 

necessary, as determined under regulations promulgated 

under this part, to prevent significant deterioration 

of air quality in each region (or portion thereof) 

designated pursuant to section 107 as attainment or 

unclassifiable. 

Commenters point out that section 107 applies only to NAAQS 

pollutants and directs that areas be designated as attainment, 

nonattainment, or unclassifiable on a pollutant-by-pollutant 

basis. Under CAA section 165(a), a “major emitting facility” 

cannot be constructed “in any area to which this part applies” 

unless it meets certain requirements. According to some 

commenters, these provisions, read together, limit PSD’s 

applications to only for NAAQS pollutants that are emitted from 

sources in areas that are designated attainment or 

unclassifiable for those pollutants. Other comments make a 
249

similar point, except state that PSD applies more broadly to 

pollutants with a local, ambient impact. 

Some commenters go on to take the position that NAAQS 

pollutants for which the area is designated attainment or 

unclassifiable are the only pollutants that can be regulated 

under any provision of the PSD requirements; while others take 

the position that once PSD is triggered for a source on the 

basis of its NAAQS pollutants, then other, non-NAAQS, pollutants 

may be regulated under certain PSD provisions, in particular, 

the BACT provision under CAA section 165(a)(4). These 

commenters agree, however, that emissions of GHGs, by 

themselves, cannot trigger PSD applicability. Finally, some 

commenters state that even if the PSD provisions cannot be read 

by their terms to preclude GHGs from triggering PSD, then they 

can be read to authorize EPA to determine that GHG emissions do 

not trigger PSD. 

We recognize, as we have said elsewhere, that a major 

purpose of the PSD provisions is to regulate emissions of NAAQS 

pollutants in an area that is designated attainment or 

unclassifiable for those pollutants. However, we do not read 

CAA sections 161 and the “in any area to which this part 

applies” clause in 165(a), in the context of the PSD 

applicability provisions, as limiting PSD applicability to those 
250

pollutants. The key PSD applicability provisions are found in 

sections 165(a) and 169(1). Section 165(a) states, “No major 

emitting facility on which construction is commenced after 

August 7, 1977, may be constructed in any area to which this 

part applies unless [certain requirements are met]. A “major 

emitting facility” is defined, under CAA section 169(1), as “any 

... stationary source[] which emit[s], or ha[s] the potential to 

emit, one hundred [or, depending on the source category, two 

hundred fifty] tons per year or more of any air pollutant.” As 

discussed elsewhere, EPA has long interpreted the term “any air 

pollutant” to refer to “any air pollutant subject to regulation 

under the CAA,” and for present purposes, will continue to read 

the “subject to regulation” phrase into that term. 

Although section 165(a) makes clear that the PSD 

requirements apply only to sources located in areas designated 

attainment or unclassifiable, it does not, by its terms, state 

that the PSD requirements apply only to pollutants for which the 

area is designated attainment or unclassifiable. Rather, 165(a) 

explicitly states that the PSD requirements apply more broadly 

to any pollutant that is subject to regulation. Moreover, two 

other requirements in CAA section 165(a) also apply to air 

pollutants broadly. Under CAA section 165(a)(3), one of the 

requirements for securing a preconstruction permit is to 
251

demonstrate that the source’s emissions “will not cause, or 

contribute to, air pollution in excess of any (A) maximum 

allowable increase or maximum allowable concentration for any 

pollutant in any area [to which the PSD requirements apply], (B) 

[NAAQS] in any air quality control region, or (C) any other 

applicable emission standard or standard of performance under 

this chapter.” As just quoted, subparagraph (C), by its terms 

clearly applies to non-NAAQS pollutants. This is because it 

refers to (i) “any other applicable emission standard,” which 

distinguishes it from subparagraph (B) and therefore from NAAQS 

pollutants; and (ii) “any ... standard of performance under this 

chapter,” which refers to standards of performance under section 

111, several of which are for non-NAAQS pollutants. See, e.g., 

40 CFR 60.33c(a) “municipal solid waste landfill emissions.” By 

the same token, CAA section 110(j) specifically contemplates 

that a source required to hold a permit under title I of the 

Clean Air Act, which includes a PSD permit, demonstrate that the 

source complies with “standards of performance,” which may 

include requirements for pollutants other than NAAQS. 

In addition, CAA section 163(a)(4) includes as a PSD 

requirement that “the proposed facility is subject to the best 

available control technology for each pollutant subject to 

regulation under this chapter emitted from, or which results 
252

from, such facility. Section 163(a)(4)’s broad reference to 

“each pollutant subject to regulation under this chapter” 

clearly indicates that it applies to non-NAAQS pollutants, as 

long as they are regulated under other provisions of the Act.39 

The D.C. Circuit, in Alabama Power v. Costle, 636 F.2d 323, 361 

n.90 (D.C. Cir. 1980) indicated that, under the law applicable 

at the time the Court handed down the decision in 1980, PSD 

 39 We find no support for the proposition raised by some 

commenters that this provision is limited to “NAAQs” pollutants. 

To the contrary, “under this chapter” unambiguous signals an 

intent to cover any pollutant regulated under the Act. Had 

Congress intended a narrower focus, they would have specified 

“any NAAQs pollutant” or any pollutant subject to regulation 

under this Part (PSD). 
253

applies to hazardous air pollutants. 40

In addition, PSD requirements are part of SIPs, and 

although SIPs generally are limited to provisions that implement 

the NAAQS, and therefore generally are limited to controlling 

NAAQS pollutants (or non-NAAQS pollutants that affect ambient 

air quality), see generally CAA section 110, Congress explicitly 

required SIPs to include requirements to protect visibility, 

under CAA section 169A-B. See CAA sections 110(a)(2)(D)(i)(II), 

169A(b)(2)(A). Congress took much the same approach with the 

PSD program, which was to require that PSD requirements be 

included in the SIPs, but to explicitly require that PSD apply 

to non-NAAQS pollutants. 

These provisions – sections 165(a)(3), 165(a)(4), and 

110(j) -- all indicate by their terms that PSD requirements 

apply to non-NAAQS pollutants. As such, they lend credence to 

our view that Congress intended the PSD applicability provisions 

to include GHG sources. At the very least, they demonstrate 

that Congress certainly knew how to specifically describe 

certain air pollutants – e.g., “air pollution in excess of ... any 

other applicable emission standard or standard of performance 

 40 In the 1990 CAA Amendments, Congress added section 

112(b)(6), which provides that PSD “shall not apply to 

pollutants listed under this section,” that is, hazardous air 

pollutants. 
254

under this chapter,” CAA section 165(a)(3)(C) – which indicates 

that its decision not to specifically describe air pollutants in 

the applicability provisions suggests an intent to cover air 

pollutants broadly. 

To return to sections 161 and the “in any area to which 

this part applies” phase in 165(a), which commenters rely on as 

the cornerstone of their argument, commenters in effect take the 

position that Congress intended the geographic references in 

these provisions – that is, the references to areas designated 

as attainment or unclassifiable – to limit the scope of the 

permitting provisions. We think it unpersuasive that Congress 

would have taken such an indirect, and silently implied, route 

to limit the scope of the permitting provisions. As noted 

previously, the permitting provisions apply broadly by their 

terms. Had Congress intended to limit PSD permitting in the 

manner urged by commenters, it certainly could have done so 

directly, such as by limiting PSD permitting to “any pollutant 

for which an area is designated attainment or unclassifiable.” 

Indeed, Congress did so in other PSD provisions, discussed 

previously. Similarly, in other sections of the CAA, Congress 

also directly limited the scope of pollutant applicability by 

specifying which pollutants are or are not subject to the 

provision. See, e.g., 111(d) (performance standards for 
255

existing sources apply only to pollutants other than NAAQS or 

HAPs), 112(a)(1) (applying air toxics requirements in section 

112 to sources that emit above the specified tonnage thresholds 

of “hazardous air pollutants”). 

In addition, although section 161 requires that SIPs 

contain emission limitations and other measures as necessary to 

prevent significant deterioration in areas designated as 

attainment or unclassifiable, it does not by its terms limit 

SIPs to only those measures. 

Most broadly, we read the PSD provisions and their 

legislative history to evidence Congress’s intent that PSD apply 

throughout the country to large sources that undertake new 

construction or modifications, and that Congress’s overall 

purpose was to assure that, as the industrial stock of the 

nation turned over, it would become cleaner for all air 

pollutants emitted. GHG sources, as a general matter, fit 

readily into this overall vision. At the time that Congress 

enacted the PSD provisions in 1977, every area of the nation was 

designated attainment or unclassifiable for at least one air 

pollutant, and that has remained the case to the present time. 

Accordingly, at all times, PSD has applied in every area of the 

country. The PSD requirements clearly cover all air pollutants 

emitted by the source, and provide a process for reviewing those 
256

emissions and determining BACT for them under CAA section 

165(a)(4). It is true that at the time Congress adopted the PSD 

provisions, it was primarily concerned about the NAAQS 

pollutants – or, as some commenters assert, pollutants with 

local, ambient impact -- because those pollutants represented a 

major component of the air pollution problems it was aware of 

and was addressing. But its overall purpose was broad enough to 

cover additional pollutants; the process it enacted for 

establishing BACT was broad enough to encompass additional 

pollutants; and the applicability provisions it established were 

phrased broadly enough to encompass additional pollutants, see

section 169(1). As a result, we believe that the PSD 

applicability provisions, which, again, refer to, as we have 

interpreted them, “any air pollutant [subject to regulation 

under the CAA]” should be seen as “capacious” and therefore 

encompass GHG sources, in much the same manner as the U.S. 

Supreme Court viewed the definition of “air pollutant” to be 

“capacious” and therefore encompass GHGs. Massachusetts v. EPA, 

549 U.S. 497, 533 (2007). 

In addition, it should not be overlooked that we have 

applied PSD to non-NAAQS pollutants since the inception of the 

program over 30 years ago. For example, prior to the 1990 CAA 

Amendments, PSD applied to HAPs regulated under CAA section 112; 
257

and over the years, EPA has established significance levels for 

fluorides, sulfuric acid mist, hydrogen sulfide, total reduced 

sulfur, reduced sulfur compounds, municipal waste combustor 

organics, municipal waste combustor metals, municipal waste 

combustor acid gases, and municipal solid waste landfill 

emissions, see 40 CFR 51.166(b)(23)(i); and EPA has proposed a 

significance level for ozone depleting substances. See 61 FR

38,307/2 (July 23, 1996). Of course, the basis for all these 

actions is PSD’s applicability to these non-NAAQS air 

pollutants. We are not aware that EPA’s actions in establishing 

significance levels for these pollutants gave rise to challenges 

on grounds that the PSD provisions do not apply to them. As the 

U.S. Supreme Court recently stated in upholding an EPA approach 

in another context: “While not conclusive, it surely tends to 

show that the EPA’s current practice is a reasonable and hence 

legitimate exercise of its discretion . . . that the agency has 

been proceeding in essentially this fashion for over 30 years.” 

Entergy Corp. v. Riverkeeper, Inc., 129 S.Ct. 1498, 1509 (2009) 

(citations omitted). 

Finally, we note that excluding GHG sources from PSD 

applicability would create inequitable results. Consider the 

hypothetical case of two sources that construct in the same 

area, each of which emits the same amount of GHGs, and that 
258

amount is large enough to trigger PSD applicability. Assume 

that the first one, but not the second, also emits NAAQS 

pollutants amounts large enough to trigger PSD applicability. 

If GHG sources are excluded from PSD applicability, then the 

first of those sources, but not the second, would be subject to 

PSD requirements for its GHG emissions. Similarly, consider the 

hypothetical case of two sources that emit identical amounts of 

the same NAAQS pollutant and identical amounts of GHGs, all 

amounts of which are large enough to trigger PSD applicability 

requirements. Assume that the first source constructs in an 

area that is an attainment or unclassifiable area for the NAAQS 

pollutant that it emits, and that the second source constructs 

in an area that is not an attainment or unclassifiable area for 

that NAAQS pollutant. Here again, if GHG sources are excluded 

from PSD applicability, then the first of those sources, but not 

the second, would be subject to PSD requirements for its GHG 

emissions. These results are inequitable and would create an 

uneven playing field and for this reason, too, support our view 

that the PSD applicability provisions apply to GHG sources. 

 Accordingly, we reject the argument that section 165 must 

be, or may reasonably be, limited in scope to pollutants for 

which an area has been designated as attainment or 

unclassifiable. Rather, the PSD applicability provision – the 
259

definition of “major emitting facility” in CAA section 169(1) – 

applies by its terms (as we have interpreted them narrowly 

through regulation) to sources emitting any air pollutant 

subject to regulation, and is not limited to any NAAQS air 

pollutant. Our research has not disclosed any explicit 

statements in the legislative history that Congress intended to 

limit PSD applicability to sources of NAAQS pollutants. 

6. Application of the “Absurd Results” Doctrine for the Title V 

Program 

 Having discussed the application of the Chevron

framework, taking account of the “absurd results” doctrine, for 

the PSD applicability requirements, we now turn towards applying 

the same approach to the title V applicability requirements. 

Because of the parallels between the PSD and title V 

applicability provisions, much of the discussion later parallels 

the discussion previously of PSD. As with PSD, we finalize, 

with some refinements, the “absurd results” basis we proposed. 

Specifically, we are revising our regulations to limit title V 

applicability to GHG emitting sources by revising the regulatory 

term, “major source,” and although our revised regulations do 

not accord with a literal reading of the statutory provisions 

for title V applicability, which are incorporated into the 

statutory definition of “major source,” we have concluded that 
260

based on the “absurd results” doctrine, a literal adherence to 

the terms of this definition is not required. A literal 

adherence would not reflect congressional intent that title V 

apply to GHG sources as a general matter. Further, we may apply 

title V to GHG sources in a phased-in manner, as we do through 

the tailoring approach, because either congressional intent is 

clear on that issue and the tailoring approach best reflects it, 

or congressional intent is unclear and the tailoring approach is 

a reasonable interpretation of the statute. However, in this 

rulemaking, as discussed previously, it is not necessary to make 

decisions, and we do not do so, about congressional intent for 

applying title V to smaller GHG sources, that is, those that 

emit at or close to the statutory thresholds, or applying title 

V to GHG sources with “empty permits.” 

 To reiterate, for convenience, the title V applicability 

provisions provide that after the effective date of a title V 

program, it is unlawful for any person to operate a "major 

source" without a title V permit, CAA §502(a), and define a 

"major source" to include "any major stationary facility or 

source of air pollutants which directly emits, or has the 

potential to emit, one hundred tons per year or more of any air 

pollutant." CAA §501(2)(B) and §302(j). 
261

Under the current interpretation of the title V 

applicability provision, EPA’s recent promulgation of the lightduty vehicle rule will trigger the applicability of title V for 

GHG sources at the 100 tpy threshold levels as of Jan. 2, 2011. 

This is because title V applicability hinges on the definition 

of “major source,” which, under EPA’s long-standing narrowing 

interpretation, but absent further tailoring, applies title V to 

sources of any air pollutant that is subject to regulation under 

another provision of the CAA. EPA’s promulgation of the lightduty vehicle rule means that GHGs will become subject to 

regulation on the date that the rule takes effect, which will be 

January 2, 2011. 

But absent tailoring, the January 2, 2011 trigger date for 

GHG PSD applicability will see an extraordinarily large number 

of sources -- some 6.1 million -- become subject to title V, an 

increase of over 400-fold over the 14,700 sources that currently 

are subject to title V each year. The great majority of these 

will be small commercial or residential sources. 

We believe that for many reasons, this result is contrary 

to congressional intent for the title V program, and in fact 

would severely undermine what Congress sought to accomplish with 

the program. As a result, under Chevron, accounting for the 

“absurd results” doctrine, the statutory definition for “major 
262

source” (as EPA has already narrowed it to refer to any air 

pollutant “subject to regulation”) should not be read to apply 

to all GHG sources at or above the 100 tpy threshold as of the 

January 2, 2011 date. Rather, the definition of “major source” 

should be tailored so that it applies to GHG sources on a 

phased-in basis, with the largest sources first, as we describe 

in this rule. 

a. Congressional Intent for the Title V Program 

As we said, previously, in a similar circumstance involving 

the PSD program, applying title V requirements to GHG sources 

without tailoring the definition of “major source” – and, as 

discussed later, without streamlining the title V requirements 

or allowing for time for permitting authorities to ramp up 

resources -- would result in a program unrecognizable to the 

program that Congress intended, and one that would be flatly 

unadministrable. Without tailoring, the PSD program would 

expand from the current 14,700 sources to some 6.1 million, with 

the great majority of the sources being small commercial and 

residential sources that not only have never been permitted 

before, but that in many cases have no applicable requirements 

under the CAA to include in the permit. In the next several 

sections, we will describe some of the specific ways that this 

literal application of title V would not only differ from, but 
263

would undermine, congressional intent. But the big picture is 

readily drawn: The influx of millions of permit applications 

would do nothing less than overwhelm the program Congress finely 

crafted for thousands of sources, with its multi-step deadlines 

measured in days and months, its multiple mandates for 

expeditious permit processing, its nuanced limitations on the 

need for permit revisions, its efforts to save smaller sources 

permit fees. Regulatory gridlock, precisely what Congress 

strove to avoid, would result. 

 Most visibly, interpreting the applicability provisions 

literally to include GHG sources at the 100/250 tpy levels would 

revise the program from what Congress envisioned in three major 

ways, the legislative history of each of which was discussed 

previously: 

• It would expand the program to cover several-hundredfold more sources than Congress anticipated 

• It would expand the program to cover very small 

sources that Congress expected would not be included 

in the program 

• It would expand the program so that the large majority 

of sources have empty permits, that is, permits 

without applicable requirements. 
264

Revising the program in this way through a literal 

interpretation of the applicability provisions – without 

tailoring the applicability requirements and without 

streamlining the program requirements -- is clearly inconsistent 

with Congress’s conception of the program’s scope, and these 

inconsistencies are foundational. Most importantly, the program 

that would result would be unduly costly to sources and 

impossible for permitting authorities to implement, and 

therefore would frustrate the purposes that Congress intended to 

achieve with the program that it did design. 

As discussed previously, Congress was fully aware that with 

the title V program, it was subjecting sources and permitting 

authorities to additional costs and administrative burdens, and 

it was fully aware of concerns that absent careful design, the 

program could become a formula for regulatory gridlock. 

Determined to make the program workable, Congress crafted the 

provisions to be efficient and workable. 

However, if title V were to apply to GHG sources at the 100 

tpy level, until EPA could develop streamlining methods, all of 

these sources newly subject to title V would need to apply for 

permits. We estimate that the commercial and residential 

sources would incur, on average, expenses of $23,370, while an 

industrial source would incur expenses of $46,350, to prepare a 
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permit application and receive a permit. The great majority of 

these sources would be small commercial and residential sources 

of the type that Congress did not expect would be included in 

title V. For example, as discussed above, the legislative 

history of title V, including both the permit program under CAA 

sections 501-506 and the “small business stationary source 

technical and environmental compliance assistance program” under 

CAA section 507, indicated that Congress did not expect that 

“printers, furniture makers, dry cleaners, and millions of other 

small businesses” would become subject to title V. House 

Committee Report, H.R. 101-590, at 354. These sources generally 

do not have the potential to emit conventional pollutants at or 

above the 100 tpy threshold. However, many do have the 

potential to emit GHGs above that threshold. Many printers and 

furniture makers use a variety of combustion equipment that has 

the potential to emit at least 100 tpy CO2, and many commercial 

dry cleaners have gas-fired driers that have the potential to 

emit at least 100 tpy of CO2. All told, there are in fact 

“millions of ... small businesses” that would become subject to 

title V. Of the 6.1 million sources that would become subject 

to title V, the great majority are small businesses. 
266

Moreover, the overall cost to all 6.1 million sources would 

be a staggering $49 billion. Imposing burdens of this magnitude 

on these sources – individually and in total – would of course 

be contrary to Congress’s efforts to minimize the expenses of 

title V, especially to small sources. The magnitude of the 

costs is, in a sense, heightened because a great many of these 

sources will not have applicable requirements to include in 

their permits; therefore, much of the costs will produce little 

benefit. 

 Yet, the most important reason why applying the title V 

program to GHG sources without tailoring, and before the 

development of streamlining methods, would be inconsistent with 

congressional intent, is that the resulting program would prove 

unadministrable. Adding some 6.1 million permit applications to 

the 14,700 that permitting authorities now handle would 

completely overwhelm permitting authorities, and for all 

practical purposes, bring the title V permitting process to a 

standstill. 

 The costs to permitting authorities of this multi-millionsource program would again be staggering. On average, and 

without streamlining, a permitting authority would expend 214 

hours, which would cost $9,844, to issue a permit to a 

commercial or residential source; and 428 hours, which would 
267

cost $19,688, to issue a permit to an industrial source. In 

all, permitting authorities would face over $21 billion in 

additional permitting costs each year due to GHGs, compared to 

the current program cost of $62 million each year. 

Beyond this disconnect with congressional expectations as 

to scope of the program, the extraordinarily large number of 

permit applications would overwhelm permitting authorities and 

slow their ability to process permit applications to a crawl. 

As described at proposal, the survey of permitting authorities 

conducted by NACAA found that a literal application of the title 

V applicability provisions to GHG sources would result in 

permitting delays of some 10 years. However, as we further 

noted at proposal, this estimate was based on the assumption 

that the applicability threshold would be 100 tpy actual 

emissions; in fact, the applicability threshold would be 100 tpy 

in potential to emit, which would sweep in many more sources. 

Moreover, as stated elsewhere, we currently estimate the amount 

of per-permit work hours for permitting authorities in 

processing title V permit applications to be several times 

higher than what we estimated at proposal. As with PSD, such a 

program is so far beyond anything within our experience that it 

is difficult to give a meaningful estimate for how long the 

permitting process would take for each permit on average, but it 
268

is clear that the period would be many years longer than the 10 

years estimated by NACAA. 

In addition, applying title V to GHG sources without 

tailoring would be in tension with a specific CAA requirement, 

that of CAA § 503(c), which imposes a time limit of 18 months 

from the date of receipt of the completed permit application for 

the permitting authority to issue or deny the permit. It would 

be flatly impossible for permitting authorities to meet this 

statutory requirement if their workload increases from some 

14,700 permits to 6.1 million. Instead, as just noted, permit 

applications would face multi-year delays in obtaining their 

permits. 

Moreover, these delays would undermine the overall 

statutory design that promotes the smooth-running of the 

permitting process, and the very purpose of the title V program 

itself. As noted elsewhere, Congress intended through title V 

to facilitate sources’ compliance with their CAA obligations by 

establishing an operating permit program that requires the 

source to combine all of its CAA requirements, and explain how 

it will assure compliance with such requirements. Congress 

established a comprehensive process to implement the operating 

permit program. Through this process, following the date that 

sources become subject to title V, they have 1 year to submit 
269

their permit applications. CAA §503(c). As noted, the 

permitting authority then has 18 months to issue or deny the 

permit. CAA §503(c). Permitting authorities must provide an 

opportunity for public comment and a hearing. CAA §502(b)(6). 

If the permitting authority proposes to issue the permit, the 

permitting authority must submit the permit to EPA for review, 

and notify affected states. CAA §505(a)(1). EPA then has 45 

days to review the permit and, if EPA deems it appropriate, to 

object to the permit. CAA §503(b)(1). If EPA does object, then 

the permitting authority must, within 90 days, revise it to meet 

the objections, or else EPA becomes required to issue or deny 

the permit. CAA §503(c). If EPA does not object, then, within 

60 days of the close of the 45-day review period, any person may 

petition EPA to object, and EPA must grant or deny the petition 

within 60 days. CAA §505(b)(2). This set of applicant, 

permitting authority, and EPA actions and deadlines establishes 

the process for the prompt and efficient issuance of operating 

permits for the appropriate universe of sources. 

But at least for an initial period, until resources could 

be ramped up and streamlining methods could be developed, the 

extraordinary numbers of these permit applicants would sweep 

aside this carefully constructed program, and instead, backlog 

the permit authorities. This initial period would last for many 
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years. As discussed elsewhere, it would take several it would 

take several years to develop and apply streamlining measures – 

in particular, general permits – and during that time, the 

permit backlog would grow so large that it would take many more 

years for permitting authorities to catch up by raising the 

requisite funds and hiring and training the necessary employees. 

What’s more, only a small fraction of these millions of 

sources newly covered by title V will be subject to any CAA 

requirements due to their GHG emissions, and we suspect that the 

majority will not be subject to any CAA requirements at all. As 

a result, for most of these sources, although they would need to 

apply for and receive a permit, there would be no applicable 

requirements to include in the permit and thus the exercise 

would not improve compliance. 

The picture that emerges from a literal application of 

title V’s requirements to GHG sources -- at the 100 tpy level, 

beginning on January 2, 2011 – shows multi-year delays in 

issuance of all permits, for both the sources that have 

applicable requirements and that Congress clearly intended the 

program to cover, and for the millions of sources that may not 

be subject to any applicable requirements. In short, this 

literal interpretation would apply title V to millions of 

sources that Congress did not intend be covered, and the ensuing 
271

administrative burdens – at least initially -- would impede the 

issuance of permits to the thousands or perhaps tens of 

thousands of sources that Congress did intend be covered. This 

is the type of “absurd results” from a literal application of 

statutory provisions that the courts have held should be 

avoided. And even beyond all that, the sheer magnitude of the 

numbers involved– millions of permits requiring thousands of 

FTEs at a cost to the permitting authorities of billions of 

dollars, all this beginning immediately at the time that GHGs 

become subject to regulation – makes clear that this result of a 

literal application of the title V provisions to GHG sources is 

not what Congress in fact intended or could conceivably have 

intended. 

b. EPA’s Reconciliation of Applicability Provisions With 

Congressional Intent 

For the reasons just described, we should not consider the 

literal meaning of the applicability provisions to be 

determinative of congressional intent as to the applicability of 

title V to GHG sources; rather, we should examine other 

provisions of the statute and the legislative history to 

determine congressional intent on that question. If 

congressional intent is clear, we must adopt and implement an 

applicability approach that is as close as possible to 
272

congressional intent; and if congressional intent is not clear, 

then we must select an interpretation that is reasonable and 

consistent with the statutory requirements. This section 

explains EPA’s view of congressional intent for the 

applicability of the title V program to GHG sources and the 

principles and approach EPA is using for tailoring. In 

addition, we also respond to other approaches that were 

suggested by commenters. 

To determine congressional intent, we consider the 

statutory provisions and legislative history, and our analysis 

is similar to ours for PSD. The most important title V 

provisions and legislative history for this purpose are the 

following: (i) The applicability provisions themselves, which, 

as we have interpreted them, apply title V to all sources that 

emit at least 100 tpy of any air pollutant subject to 

regulation. CAA sections 502(a), 501(2)(B), 302(j). Although 

we do not believe these provisions should be applied literally 

to GHG sources, their broad phrasing indicates, directionally, a 

congressional intent towards inclusiveness of sources in title 

V, including GHG sources. (ii) The provisions for general 

permits, CAA section 504(d); and title V fees, CAA section 

502(b)(3)(A). These provisions give title V an important 

measure of flexibility as to its scope. The explicit 
273

authorization of general permits means that title V may be 

applied to more sources and more efficiently, thereby saving 

costs to both source and permitting authority. The requirements 

for permit fees provide a mechanism for permitting authorities 

to, over time, develop their programs to cover more sources. In 

this sense, these provisions could be construed to indicate 

congressional intent to apply title V inclusively, to the extent 

that permitting authorities can accommodate additional sources 

through general permits and permit fees. (iii) The detailed 

procedural requirements -- including time periods, such as the 

18-month time period for action on permit applications -- for 

title V permit processing. CAA sections 503, 505. Although 

these requirements are consistent with applying title V to GHG 

sources -- in the sense that at least in theory, there is 

nothing intrinsic to GHG sources that would mean that permitting 

authorities could not comply with these requirements – these 

requirements cast doubt on whether Congress can be said to have 

intended that title V cover the many small GHG sources in light 

of the risk that including all those sources in title V would 

strain the process. (iv) The provisions and legislative history 

concerning applicable requirements, which indicate that a 

purpose of title V is to include sources’ applicable 

requirements in their permits. CAA sections 503(b)(2), 504(a). 
274

These provisions, and the accompanying legislative history, 

discussed above, suggest an intent to include within title V GHG 

sources that have applicable requirements, but may also suggest 

that Congress would not have intended to include in title V the 

large numbers of GHG sources that have empty permits. (v) The 

small-business-assistance provisions of section 507 and the 

legislative history of title V – both the permitting program and 

the small-business-assistance program -- concerning the scope of 

the permitting program and small businesses. These indicate 

that Congress intended title V to cover some tens of thousands 

of sources, and did not intend that title V apply to small 

businesses. These provisions and legislative history suggest 

that Congress did not intend to include small GHG sources. 

Finally, the legislative history of title V does not explicitly 

mention GHG sources, which could suggest that Congress did not 

have occasion to focus on whether and how title V would apply to 

GHG sources. 

With all this, we believe that Congress had a clear intent 

on the question of whether title V applies to GHG sources, and 

that was to apply title V to GHG sources. As with PSD, the most 

important indication of congressional intent in this regard is 

the applicability provisions, which provide, in part, that title 

V applies to “any stationary facility or source of air 
275

pollutants which directly emits, or has the potential to emit, 

[the requisite quantity] of any air pollutant.” CAA §§ 502(a), 

501(2)(B), 302(j). This term is quite broad, and should be read 

to include GHG sources. See Massachusetts v. EPA, 549 U.S. 497, 

533 (2007) (“Because greenhouse gases fit well within the Clean 

Air Act's capacious definition of “air pollutant,” we hold that 

EPA has the statutory authority to regulate the emission of such 

gases from new motor vehicles.”). Moreover, including GHG 

sources – under certain circumstances – is consistent with the 

various statutory provisions and statements in the legislative 

history described previously. 

As to the question of how title V applies to GHG sources, 

we believe that here too, Congress can be said to have expressed 

an intent, and that is to apply title V to as many GHG sources 

as possible and as quickly as possible, at least to a certain 

point. As with PSD, we believe that this flows logically from 

the inclusive direction of the applicability provision, the 

flexibility in title V’s scope that is inherent in the 

provisions authorizing general permits and requiring permit 

fees, the provisions and legislative history indicating that one 

of title V’s purposes is to require sources with applicable 

requirements to gather those requirements into a permit in order 

to promote compliance and enforcement, the detailed process 
276

requirements, and the legislative history that focuses on 

Congress’s concern about costs to sources and administrability. 

That is, at first, title V may apply to the largest GHG sources 

because they may be expected to have applicable requirements, 

they can be expected to bear the costs of complying, and if 

their inclusion strains the resources of the permitting 

authorities, title V contains tools to address that. In 

addition, including the largest sources under the Tailoring Rule 

will not disrupt the detailed process requirements. Over time, 

more sources may be included in title V, consistent with those 

provisions and legislative history. 

On the other hand, if Congress cannot be said to have 

expressed an intent as to the manner and scope of title V 

applicability to GHG sources, then, under Chevron step 2, EPA 

may apply a reasonable interpretation of the applicability 

provision to determine the scope of coverage of GHG sources that 

is consistent with the statutory requirements. The Tailoring 

Rule qualifies as such an interpretation. The Tailoring Rule in 

effect reads the applicability provisions not to apply title V 

to GHG sources at or above the 100 tpy level, but instead to 

apply title V to as many of the GHG sources at or above that 

level as possible and as quickly as possible, starting with the 

largest sources first, that is consistent with both the 
277

permitting authorities’ ability to administer the program and 

with a sensible imposition of costs to sources. However, as 

part of the tailoring approach, we recognize that we may at some 

point determine that it is not appropriate to include in title V 

either the smallest of the GHG sources or sources with empty 

permits. 

As with PSD, we do not believe it is necessary to come to a 

conclusion as to whether, under Chevron step 1, Congress 

intended that title V apply, or not apply, to GHG sources as 

small as the statutory levels, or whether, if Congress expressed 

no clear intent on that question, it is reasonable under Chevron 

step 2 to apply title V to GHG sources at that level, all within 

the context of the tailoring approach. In this rulemaking, we 

promulgate steps that cover larger sources and we provide that 

we will not apply title V to sources below the 50,000/50,000 tpy 

CO2e level for at least the first six years. Because there is 

no need to come to decisions concerning the smaller sources in 

this rulemaking, we intend to consider them further, along with 

the legal issues concerning congressional intent, in the 

subsequent rulemaking that we commit to doing as part of this 

action. 

The specific phase-in schedule will depend on the 

following: We will gather information about the permitting 
278

authorities’ ability to process permits, and we will develop 

streamlining techniques. Based on that information, we will 

address expanding the title V program in a step-by-step fashion 

to include more sources over time. Each step will be based on 

our assessment of the permitting authorities’ and sources’ 

ability to comply with their respective obligations under the 

title V program. 

 We recognize that the availability of permit fees to 

support title V permit actions creates a potentially important 

source of resources, and that this has implications for the 

permitting authorities’ ability to implement the title V program 

for sources of GHGs. At least in theory, permitting authorities 

could assess and collect sufficient fees to support hiring and 

training sufficient personnel so that they could expand their 

programs to match the expansion in the number of sources covered 

by the program. 

Even so, title V fees cannot be considered a panacea that 

will resolve all resource problems that permitting authorities 

will have, for several reasons. Permitting authorities will 

likely be constrained as to the rate in which they can increase 

fees in light of the costs to sources. As indicated elsewhere, 

at least at the outset of the program before streamlining 

techniques have been developed, a literal application of the 
279

title V applicability provisions to GHG sources would, on 

average, cost each industrial source $46,400 and each commercial 

or residential source $23,200 to complete the permit application 

and take other associated actions; and it would cost each 

permitting authority, on average, $19,678 to process the 

industrial source permit and $9,839 to process the commercial or 

residential source permit. Particularly in light of the high 

costs to sources of applying for a permit, it is not likely that 

permitting authorities would be able to pass on to the sources 

in the form of fees the entirety of the permitting authorities’ 

own high costs for processing those permits, at least not right 

away. Even to the extent it would be possible to raise permit 

fees, permitting authorities would have to undergo a process to 

assess, impose, and collect those fees, and then hire and train 

personnel. The survey from the state and local agencies 

described previously forecast a 2-year period for hiring and 

training, without counting time for the fee process. For these 

reasons, we do not believe that the authorization for fees will 

allow the permitting authorities either to accelerate Steps 1 or 

2 of the tailoring schedule or to permit a larger number of 

sources at those steps. Step 1 will take effect on January 2, 

2011, step 2 will take effect on July 1, 2011, and the process 

for determining and collecting fees, and then hiring and 
280

training personnel will take at least several years after July 

1, 2011. 

Moreover, we do not believe that the authorization for fees 

means that permitting authorities can reasonably be expected to 

permit title V sources at levels below 50,000 tpy CO2e before 

2016. The next level below 50,000 tpy CO2e for which we have 

data is 25,000 tpy CO2e, and the costs to permitting authorities 

to run their programs at that level ($126 million) is more than 

double their current costs ($62 million). We do not consider it 

reasonable to expect permitting authorities to more than double 

their program within the first 6 years of title V applicability 

to GHG sources. That it is not reasonable to expect that is 

made even clearer when the permitting authorities’ burdens in 

implementing their PSD programs are considered. The ability of 

permitting authorities to impose fees may have more important 

implications for subsequent steps, and as we address those 

subsequent steps in future rulemakings, we will consider the 

fees. EPA’s approach to fees in this rulemaking is discussed 

elsewhere. 

c. Other Possible Approaches to Reconciling Literal Reading of 

Title V Applicability Provisions and Congressional Intent 

Having described how the Chevron framework, accounting for 

the ”absurd results” doctrine, applies to title V requirements 
281

in this case and why it supports this Tailoring Rule -- under 

which we expect to apply title V to more sources, in a step-bystep fashion, over time -- we turn to the last part of our 

discussion of this doctrine. Here, we address another possible 

approach, which is that that EPA should apply the title V 

program only to sources that are subject to applicable 

requirements, so that sources should not be required to hold 

empty permits (i.e., permits issued to a source that is not 

subject to any applicable requirement for any pollutant). To 

the extent that commenters argue that the statute requires EPA 

to adopt a “no-empty –permits” theory, we disagree. We believe 

that although various provisions of title V indicate that one of 

title V’s purposes is to gather a source’s applicable 

requirements into a single permit, see CAA §§ 503(b)(1), 504(a), 

we do not read those provisions as expressly limiting, as a 

matter of Chevron step 1, title V to sources with applicable 

requirements. The applicability provisions, by their terms, 

include sources based on amount of emissions, and do not include 

any explicit limits to applicability based on whether the 

sources has applicable requirements. We also note that to date, 

we have issued permits to sources without applicable 

requirements, albeit on rare occasions. We believe that the 

tailoring approach we adopt in this rulemaking best reconciles 
282

the statutory provisions with congressional intent. Moreover, 

we are concerned that adopting an empty permits approach in 

place of the tailoring approach might not alleviate the very 

large number of small sources overwhelming the permitting 

process. We note, as discussed later in this section, that 

there will be no empty permits in Step 1 and we believe there 

will be extremely few, if any, “empty permits” in Step 2. We 

need to further assess the potential for this approach to 

relieve burden in future steps, taking into account that the 

need for requirements in title V permits will vary based on the 

requirements of each SIP, and noting that some SIPs contain 

broadly applicable requirements. In light of this uncertainty, 

we cannot conclude that this approach would better achieve 

congressional intent. Thus, we disagree that adopting the empty 

permit approach at this time is required or appropriate. 

7. Additional Rulemaking for the PSD and Title V Programs 

 The previous sections 5 and 6 discussed our application of 

the Chevron framework, accounting for the “absurd results” 

doctrine, to the PSD and title V applicability requirements, 

respectively. As another point in this regard, which is 

relevant for both PSD and title V purposes, we also commit to 

subsequent rulemakings in which we may further address the 

“absurd results” doctrine. 
283

Specifically, we will propose or solicit comment on 

establishing a further phase-in, that is, a step 3, that would 

apply PSD and title V to additional sources, effective July 1, 

2013, and on which we commit to take final action, as supported 

by the record, by no later than July 1, 2012. We further commit 

to completing another round of rulemaking addressing smaller 

sources by April 30, 2016. Our action in that rulemaking would 

take into account the severity of the remaining problems 

associated with permitting authority burden and source costs. 

While committing to future action, we do not decide in this 

rule when the phase-in process will ultimately end, or at what 

threshold level, because all that depends on uncertain variables 

such as our progress in developing streamlining approaches and 

on permitting authorities’ progress in developing permitting 

expertise and acquiring more resources. We may continue the 

phase-in process with further rulemaking(s) after 2016. 

Alternatively, we may make a final determination through future 

rulemaking that, under the “absurd results” doctrine, PSD and/or 

title V do not apply to GHG sources that, while small and 

relatively inconsequential in terms of GHG contribution, are 

above the statutory tonnage thresholds for these programs, and 

thereby end the phase-in process. In addition, we may consider 
284

whether to limit title V applicability to GHG sources in order 

to minimize the number of GHG sources with “empty” permits. 

8. Rationale for the Phase-In Schedule for Applying PSD and 

Title V to GHG Sources 

 Having discussed in sections V.B.5, V.B.6, and V.B.7 

previously the reasons for tailoring the PSD and title V 

programs, we now describe our rationale for selecting the 

specific phase-in schedule in this rule for applying PSD and 

title V to GHG-emitting sources. To reiterate for convenience, 

under Step 1 of this schedule, which begins on January 2, 2011, 

(i) PSD applies to the GHG emissions of “anyway” PSD sources, 

that is, sources that are subject to PSD anyway due to their 

emissions of conventional pollutants and that undertake a 

modification that results in an increase of at least 75,000 tpy 

CO2e; and (ii) title V applies to “anyway” title V sources, that 

is, sources that are subject to title V anyway due to their 

emissions of conventional pollutants. Under Step 2, which 

begins on July 1, 2011, (a) sources will be subject to PSD on 

account of their GHG emissions if they newly construct and emit 

at least 100,000 tpy CO2e, or if they are existing sources that 

emit at least 100,000 tpy CO2e of GHGs and make a modification 

that results in the emission of at least 75,000 tpy CO2e; and (b) 

existing and new sources will be subject to title V on account 
285

of their GHG emissions if they emit 100,000 tpy CO2e in GHG 

emissions. In addition, EPA intends to begin another round of 

rulemaking – Step 3 – in 2011 and commits to complete it by July 

1, 2012. In that rulemaking, we will propose or solicit comment 

on a further phase-in of GHG sources for PSD and title V 

applicability, and we may propose or solicit comment on another 

application of the “absurd results” doctrine that excludes 

categories of sources from PSD or title V. However, under this 

rule, in no event will EPA apply PSD or title V to sources below 

the 50,000 tpy CO2e levels in step 3, or any other step we might 

promulgate prior to April 2016. In addition, EPA commits to 

conduct a study, to be concluded by April 30, 2015, evaluating 

the status of PSD and title V applicability to GHG sources, and, 

based on the study, complete a rulemaking by April 30, 2016 that 

addresses another round of a phase-in. 

a. Rationale for Step 1 

 In Step 1 of our tailoring approach, which begins on 

January 2, 2011, PSD and title V requirements will apply to only 

those sources that are subject to PSD or title V requirements 

anyway due to their conventional pollutants (“anyway” sources) 

and that, in the case of PSD, make modifications that result in 

an increase in GHG emissions of at least 75,000 tpy CO2e. No 

sources would become major for PSD or title V under this step 
286

based on their GHG emissions alone. This section describes our 

proposal, comments on the proposal and our response to those 

comments, and our rationale for Step 1. 

(1) Proposal 

In our proposal, we proposed (i) the application of PSD and 

title V requirements to sources that emit at least 25,000 tpy 

CO2e, (ii) a PSD significance level of between 10,000 and 25,000 

tpy CO2e, and (iii) a commitment to undertake a study to be 

followed by further rulemaking after 6 years. In addition we 

solicited comment on the alternative of limiting PSD and title V 

applicability to “anyway” sources for at least the first six 

years. Under this approach, PSD and title V applicability would 

be determined based on non-GHG pollutants, and without regard 

to GHGs, but those sources subject to PSD would also be subject 

to BACT requirements for GHGs if their GHG emissions exceeded 

the significance level established in the final rule, and those 

sources subject to title V would be required to include any 

applicable requirements for GHGs in their permits. 

(2) Comments 

Many commenters supported this “anyway”-source approach, 

and offered a variety of reasons: According to the commenters, 

(i) this approach is a better reading of Congress’s intent in 

the Act and is consistent with Alabama Power v. Costle, 636 F.2d 
287

323 (D.C. Cir. 1980); (ii) this approach would reduce the 

permitting workload on sources currently considered minor and 

focus PSD and title V requirements on large sources of non-GHG 

pollutants, as intended by Congress; (iii) it is appropriate to 

base PSD and title V applicability on non-GHG emissions until 

data on GHG emissions are available from the GHG Reporting Rule; 

(iv) in the initial phase, this approach would be more 

straightforward to administer, would provide a more predictable 

permitting workload, and would prevent a flood of newly 

regulated sources from overburdening state agencies; (v) this 

approach would provide permitting agencies time to develop 

experience handling GHG sources and requirements under the PSD 

and title V programs; (vi) this approach would provide EPA and 

the permitting agencies the time needed to develop streamlining 

techniques; (vii) this approach is consistent with the “absurd 

results” and “administrative necessity” doctrines because the 

scope of the permitting programs would remain consistent with 

both Congressional intent and current administrative practice, 

but EPA and state agencies would still be allowed to begin 

regulating GHG emissions from existing PSD and title V sources; 

and (viii) sources already required to obtain PSD permits are 

best equipped to work through BACT issues with permitting 

authorities. 
288

Commenters added that if BACT is applied for GHG due to 

permit actions involving non-GHG pollutants, EPA would need to 

set a significance threshold for the application of BACT, 

without which BACT could apply to very small (e.g., 1 ton) GHG 

increases associated with projects that otherwise triggered PSD 

for increases of non-GHG. 

(3) Determination as to Step 1, PSD and Title V Applicability 

and PSD Significance Level 

After considering the administrative burdens from increased 

permitting actions and the need for permitting authorities to 

have sufficient time to develop necessary expertise and staffing 

resources to address that burden, we have decided in this final 

action to establish the “anyway” source approach as Step 1. 

Beginning on January 2, 2011, sources subject to PSD 

requirements for their conventional pollutants anyway will be 

required to apply BACT to their GHG emissions if they construct 

or modify and in so doing, emit at least 75,000 tpy CO2e in GHGs. 

Similarly, sources subject to title V requirements anyway due to 

their conventional pollutants will be required to meet certain 

requirements for their GHGs, as described elsewhere. These 

requirements at Step 1 for PSD and title V will not expire. On 

July 1, 2011, a further phase-in of PSD and title V 

applicability – Step 2 – will kick in. 
289

The “anyway” source approach has particular appeal during 

this, the first step of the phase-in approach because it begins 

to apply key PSD and title V program requirements as soon as 

January 2, 2011 to large sources of emissions, but because it 

applies only to sources that are already subject to PSD for 

other pollutants, it can be implemented efficiently and with an 

administrative burden that is manageable in the next 8 months. 

We expect that under this approach, the sources and permitting 

authorities will still face substantial additional work due to 

the GHG emissions. In addition to the activities discussed 

elsewhere, there will be significant and complex policy 

questions about how BACT will be implemented for GHGs that must 

be resolved. These issues will include how to determine BACT 

for GHGs, how to do netting, and other similar issues. Even 

with EPA guidance, many case-specific policy issues will arise 

and will have to be resolved by the permitting authority in the 

context of a specific permit application. Nevertheless, with 

the “anyway” source approach, this work will be manageable 

because the associated permitting burden will be limited to 

adding a GHG component to each existing permit action for which 

it will be required, and will avoid the significantly greater 

burdens associated with large numbers of new permit actions that 

would be required for sources and modifications that would be 
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subject to PSD for the first time. Instead, this “anyway” 

source approach allows permitting authorities sufficient time to 

develop necessary expertise and staffing resources to address 

GHG BACT. 

We agree with commenters that the establishment of a 

significance level – which, in effect, is a BACT threshold -- is 

appropriate, and we have decided to establish this level at 

75,000 tpy CO2e because, for reasons discussed later, that is the 

level that will apply during step 2. At this level, the 

administrative burdens, described later, will be manageable. 

Importantly, we believe a consistent significance level between 

Steps 1 and 2, as opposed to a lower significance level in Step 

1, will provide for a smoother transition and avoid the problems 

that would arise if PSD applied to modifications during Step 1 

that PSD would not apply to in Step 2. Otherwise, we would 

create a perverse incentive for companies to delay such projects 

until Step 2 to avoid BACT. 

We estimate that Step 1 will result in a 23 percent 

increase in permitting authority work hours and a $3 million 

increase – which amounts to a 25 percent increase from the 

current program cost of $12 million -- in their annual costs for 

running PSD programs. This is primarily due to the GHG BACT 

review requirements. For title V programs, we estimate a 2 
291

percent increase in permitting authority work hours and a $1 

million increase in the title V annual program costs for 

permitting authorities under Step 1 as compared to the current 

program cost of $62 million. These work hours and costs will be 

needed primarily to review GHG emissions information, add any 

GHG-related requirements to title V revisions and renewal 

actions that would otherwise be occurring, respond to comments 

and petitions from the public, as well as develop fee 

requirements and make fee determinations associated with issuing 

new or revised title V permits that add GHG-related information. 

For both the PSD and title V programs on a combined basis, the 

additional costs for Step 1 will be $4 million, which amounts to 

a 5 percent increase in the current combined program cost of $74 

million. 

In addition to these workload and monetary costs, 

permitting authorities will confront additional burdens before 

and during Step 1, which we have not attempted to quantify. One 

of the most significant of these is training staff in the PSDrelated areas of GHG emissions calculations and BACT 

evaluations. In addition, permitting staff will need to build 

staff expertise and capacity for addressing GHG requirements in 

preparation for Step 2, which will begin only 6 months after 

Step 1; and in communicating and providing outreach to sources 
292

addressing GHG emissions for the first time. Based on comments 

we received on the proposal from permitting authorities, we 

believe these additional training and outreach requirements – 

for both the PSD and title V programs -- will add significantly 

to the permitting authorities’ burden during the initial 6-month 

period under Step 1. 

 We believe that these administrative burdens are 

substantial but manageable. Following this action, permitting 

authorities will have only 8 months to prepare for Step 1, when 

they will need to increase their resources by 5 percent for both 

the PSD and title V programs combined, and be able to implement 

BACT requirements for GHG sources. During Step 1, they will 

need to prepare for Step 2, when, as discussed later, they will 

need to process over 900 additional PSD permits each year and 

begin to process over 2,600 additional title V permit actions. 

We have decided to limit Step 1 to the “anyway” source 

approach, and not apply PSD or title V to sources based on their 

GHG emissions, for several reasons. First, we believe that the 

administrative burdens described previously are the most that 

the permitting authorities can reasonably be expected to manage 

before and during Step 1. Tighter PSD and title V applicability 

requirements would mean greater administrative burdens. 
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Second, we believe that the costs of GHG permitting to the 

sources, as described previously, are substantial and as a 

result, necessitate that we wait for the permitting authorities 

to develop the PSD and title V programs for GHG sources during 

the first 6 months of 2011 before subjecting sources to PSD and 

title V requirements on account of their GHG emissions. By July 

1, 2011, when Step 2 takes effect, the PSD and title V programs 

will be better developed. For example, the permitting 

authorities will have more experience making BACT 

determinations. In addition, by that time, sources will have 

had more time to prepare for the permitting processes. In 

addition, as suggested by one commenter, the additional time 

will allow sources and permitting authorities to address the 

current uncertainty surrounding how to measure high-GWP gases. 

Third, we estimate that “anyway” sources account for 

approximately 65 percent of total national stationary source GHG 

emissions. As a result, limiting Step 1 to these sources will 

still capture a large portion of the GHG inventory. 

A large number of commenters urged us to leave this 

“anyway” source approach in place until such time as we complete 

an assessment and conduct further rulemaking, which we proposed 

would be 6 years from now. We are not taking this action; 

rather, for the reasons discussed next, we believe it is 
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reasonable to use GHG thresholds to begin to phase in PSD and 

title V applicability to additional sources in Step 2. 

b. Rationale for Step 2 

(1) Proposal 

We proposed to establish the applicability level for PSD 

and title V to GHG sources at 25,000 tpy CO2e, and we proposed a 

PSD significance level in the range of 10,000 to 25,000 tpy CO2e. 

Our burden estimates at proposal led us to conclude that at 

those threshold levels, for the PSD program, “approximately 400 

additional new or modified facilities would be subject to PSD 

review in a given year. These include approximately 130 new 

facilities and approximately 270 modifications....” 74 FR 55,331, 

col. 1. We estimated that processing these numbers of 

additional permits, along with doing the additional work 

associated with GHG emissions from sources subject to PSD anyway 

due to their conventional emissions, would increase permitting 

authority burdens by “approximately 112,000 staff hours at an 

additional cost of approximately $8 million. This workload 

amount represents an increase of about 1.3 times, or 32 percent, 

in the current burden for permitting authorities on a nationwide 

basis.” Id. col. 3. We concluded that “this additional burden 

is manageable,” but that “any threshold lower than 25,000 tpy 

CO2e, would create undue administrative burdens.” Id. 
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 For the title V program, we estimated that at a 25,000-tpy 

CO2e permitting threshold, “about 13,600 existing facilities” 

would become subject to title V, and that to manage the 

additional workload associated with permitting those sources and 

with the other permit revisions and modifications that would 

result from the 25,000 tpy CO2e threshold, permitting authorities 

would require an additional 492 FTEs, which would be an 

estimated 50 percent increase over current title V staffing 

levels. 74 FR 55,335, cols. 1-2. 

(2) Comments 

We received a significant number of comments from both 

permitting authorities and industry representatives that our 

proposed GHG threshold of 25,000 tpy CO2e for major source 

applicability was too low and would result in an unmanageable 

amount of permitting actions in the near term. Many offered 

evidence that we severely underestimated both the number of 

permitting actions and the per-permit administrative burden, for 

both PSD and title V programs. 

 Commenters also asserted that the proposed 25,000 tpy 

threshold is too low because it will subject small sources 

(including many small businesses) to PSD and title V, which is 

not in keeping with Congress’s intent to limit PSD and title V 

to large sources when Congress set the 100/250 tpy thresholds 
296

for the permitting programs. EPA, in collaboration with the 

Small Business Administration (SBA), conducted an outreach 

meeting designed to exchange information with small entities 

that may be interested in these regulations. The EPA took this 

small business outreach effort into account when finalizing this 

rule. Many commenters from this outreach effort said that there 

were many more small businesses that would become to PSD and 

title V due to the proposed permitting thresholds than EPA 

estimated at proposal. 

Many commenters recommended specific major source 

thresholds for PSD and title V, including levels of 25,000 (as 

proposed), 40,000, 50,000, 100,000, 150,000, 250,000, and 

1,000,000 tpy CO2e. A majority of the commenters –_ including 

both industry and state agency commenters -- recommended major 

source thresholds of 100,000 tpy CO2e. However, several state 

agency commenters recommended thresholds of 50,000 tpy CO2e. 

Other commenters recommended sector-specific thresholds. For 

example, solid waste industry commenters suggested thresholds of 

820,000 tpy CO2e for PSD [which they calculate to be equivalent 

to the existing PSD threshold for “municipal solid waste 

landfill emissions,” i.e., 250 tpy non-methane organic emissions

(NMOC)] and 320,000 tpy CO2e for title V (calculated to be 

equivalent to the existing major source applicability threshold 
297

of 100 tpy NMOC). Other commenters urged EPA to set the GHG 

thresholds at levels that correspond to emissions of 

conventional pollutants at the 100/250 tpy level. 

Many of the commenters that recommended increasing the 

thresholds cited EPA’s estimates that a particular threshold 

would significantly reduce the number of sources subject to the 

rule while causing only a slight reduction in the percentage of 

GHGs captured. Several of these commenters noted that Table 

VIII-2 in the proposal preamble indicates that shifting the 

major source threshold for PSD from 25,000 to 100,000 tpy CO2e 

would reduce the number of major sources from 13,661 to 4,850 

while reducing the coverage of U.S. stationary source GHG 

emissions by only about 4 percent. Other commenters referred to 

the RIA for the GHG Reporting Rule to conclude that raising the 

threshold from 25,000 to 100,000 tpy CO2e would exclude thousands 

of entities that, on a combined basis, emit only one percent of 

the nation’s GHG emissions. See the Response to Comments 

document for this final rulemaking for more detailed description 

of comments received on our proposed burden assessment. 

 Many commenters also recommended specific PSD GHG 

significance thresholds, including levels of 10,000 (as 

proposed), 15,000 (within the proposed range), 25,000 (also as 

proposed), 40,000, 50,000, and 100,000, and 150,000 tpy CO2e, as 
298

well as suggesting sector-specific thresholds. These 

recommendations were based on the view that we had 

underestimated the number of modifications and that the burden 

of permitting at the proposed levels would therefore be much 

worse than we projected. A number of the commenters argued that 

the significance threshold should be no less than the major 

source threshold, at whatever level that is set. The largest 

number of commenters recommended a PSD significance threshold of 

100,000 tpy CO2e, although significant numbers also support 

25,000 and 50,000 tpy CO2e. 

(3) Rationale for step 2 

 Based on these comments, we reassessed our original burden 

estimates from our proposal. This reassessment is discussed at 

the beginning of this section. We decided that, once this 

adjustment is taken into account, the burdens at the proposed 

25,000 threshold and the proposed 10,000-25,000 significance 

levels would be unmanageable. We therefore evaluated higher 

thresholds ranging from a 25,000 tpy CO2e major source 

applicability level for PSD and title V to a 50,000, 75,000, or 

100,000 tpy CO2e level, with associated PSD GHG significance 

levels of equal or lesser magnitude; and we selected the 

100,000/75,000 tpy CO2e level. Central to our decision to 

promulgate higher thresholds than what we proposed is our 
299

recognition, based on comments and further analysis, that 

applying PSD to GHG sources at the statutory or any other 

threshold level or significance level that we have considered 

would result in (i) a greater number of sources, and 

significantly greater number of modifications than we first 

estimated becoming subject to those programs; and (ii) a greater 

per-permit cost than we first estimated to the permitting 

authority of processing those permit actions. We discussed our 

revised estimates and reasoning at the beginning of this 

section. 

We now estimate that the 25,000/25,000 tpy level would 

result in 250 additional PSD permit actions for new construction 

(either for GHG-only sources or additions to otherwise occurring 

permits) and an additional 9,200 PSD permits for modifications 

each year (compared to our estimate at proposal of 130 for new 

construction and 270 for modifications). This level of 

permitting would require an additional 2,815,927 work hours, or 

1,400 FTEs (compared to our estimate at proposal of 112,000 

[additional?] work hours, or 57 FTEs); and would cost an 

additional $217 million each year (compared to our estimate at 

proposal of an additional $8 million). See 74 FR 55,331 

(proposal). This $217 million amount represents approximately a 
300

1,800 percent increase over current permitting authority annual 

cost of $12 million for the major NSR programs 

 For title V, under our final burden analysis at a 25,000 

tpy CO2e threshold, we estimate a $64 million annual increase in 

program costs to permitting authorities to add GHG emission 

sources, which reflects a greater than 100 percent increase over 

current programs costs of $62 million. We estimate that this 

increased burden would result in the need for almost 700 new 

FTEs nationwide at permitting authorities (compared to our 

estimate at proposal of 492 additional FTEs, or about a 50% 

increase in existing program size). This increase in burden is 

due to an estimated annual increase of 2,500 new title V 

permits, over 9,500 permit revisions, and over 2,500 permit 

renewal actions due to GHG emission sources. These additional 

title V actions compare to current annual program actions of 

approximately 50 new title V permits, 1,394 significant 

revisions, and 3,267 permit renewals. 

 Based on this information, we have decided not to finalize 

our proposal to apply a 25,000 tpy CO2e applicability threshold 

to GHG sources at the time that PSD and title V take effect. At 

that level, too many sources – many more than we thought at 

proposal – would be subject to high permitting costs. In 

addition, permitting at that level and at that time would not be 
301

administratively feasible. The resulting increase in the number 

of PSD and title V permitting actions and workload would create 

insurmountable resource demands for permitting agencies in the 

near term, which would jeopardize the functioning of these 

permitting programs. We are mindful that not only would the 

permitting programs have to bear the costs that our estimates 

are able to monetize, but they would also incur burdens 

associated with hiring and training staff to make and implement 

GHG BACT determinations, GHG emissions evaluations, and other 

evaluations required under the PSD program for a wide variety of 

formerly unpermitted sources, including significant numbers and 

types of small manufacturing and commercial or residential 

establishments. They would also incur burdens associated with 

reviewing applications, citizen comment and petitions, and the 

need to communicate and provide outreach to new categories of 

sources, including, again, significant numbers and types of 

small manufacturing and commercial or residential sources. 

Thus, the increased administrative burdens at the 25,000/25,000 

tpy CO2e levels are so great that we have concluded that they 

would not be consistent with the goals of avoiding absurd 

results that contravene Congressional intent, including avoiding 

a permitting burden that would overwhelm the capacity of 

permitting authorities to effectively implement their programs. 
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Based on our revised burden analysis, in this final action, 

we have decided to establish a multi-step, phase-in approach 

that contains a significantly higher initial threshold level: 

We have determined that a 100,000 tpy CO2e major source threshold 

level for PSD and title V purposes, and a 75,000 tpy CO2 

significance level, produce a level of permitting activity that 

would certainly be an increase over current workload, but that 

would be administratively feasible by July 1, 2011. As a 

result, we have decided to finalize these thresholds as Step 2. 

In reaching this conclusion, we needed to consider the 

permitting authorities’ capacity to address newly-major sources 

as expeditiously as possible. Note that our Step 1 approach 

does not cover newly-major sources. As a result, step 2 

threshold and timing has to be established in a way that takes 

into account permitting authority challenges in addressing many 

sources and categories that would be subject to major source 

permitting for the first time. 

 We considered the various PSD and title V threshold 

applicability and significance level options in our final burden 

analysis, summarized in Table V-1, including levels at 50,000 

CO2e, and 100,000 CO2e. As Table V-1 indicates, we estimate that 

a 100,000 tpy CO2e major source applicability threshold would 

result in approximately 550 sources becoming newly classified as 
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major sources for PSD based on their GHG emissions, while a 

50,000 tpy CO2e threshold would result in 3,500 newly classified 

major sources. 

 We then considered the impact on both PSD and title V 

programs of different PSD significance level options for GHGs. 

The choice of a PSD significance level has a direct impact on 

title V burdens because PSD permit requirements resulting from 

modification activities will result in required title V permit 

revisions. We developed PSD and title V burden estimates based 

on significance levels of 50,000 tpy, 75,000 tpy and 100,000 tpy 

CO2e, combined with a major source applicability level of 100,000 

tpy CO2e. 

At a 50,000 tpy CO2e significance level, we estimated an 

annual increase of approximately 1,800 PSD permitting actions 

and almost 2,000 additional title V permitting actions, as 

compared to Step 1. At a 75,000 tpy CO2e significance level, we 

estimated an annual increase of approximately 900 PSD permitting 

actions and just over 1,000 additional title V permitting 

actions as compared to Step 1. At a 100,000 tpy CO2e 

significance level we estimated an annual increase of 

approximately 25 PSD permitting actions and 210 additional title 

V permitting actions as compared to Step 1. For title V, under 

these different scenarios, the major source applicability level 
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of 100,000 tpy CO2e results in approximately 200 new permits 

annually, but, as noted, the choice of significance levels 

affects the number of required permit revisions. 

 Based on this information, we have decided to set our final 

Step 2 thresholds at 100,000 tpy CO2e for major source 

applicability under PSD and title V and at a 75,000 tpy CO2

significance level for PSD. Overall, we estimate that the 

almost 900 additional PSD permitting actions (virtually all of 

which would be modifications) per year at these levels will 

result in an approximately a $21 million increase (from Step 1) 

in states’ annual costs for running PSD programs. In addition, 

we estimate that the 1,000 additional title V permit actions 

will cause the total title V burden for permitting authorities 

to increase by $6 million annually from Step 1. This total 

increase in permit program burdens of $27 million represents a 

34 percent increase over the $78 million in total cost of PSD 

and title V programs at Step 1. We consider this a substantial 

increase particularly because Step 2’s start date of July 1, 

2011 is only 6 months after Step 1’s start date of January 2, 

2011. What’s more, Step 1 will entail a substantial increase in 

permitting authority obligations, so that adding the costs of 

Step 1 and Step 2 together -- $31 million – means that 

permitting authorities will be required to increase their 
305

permitting resources by approximately 42 percent between now and 

Step 2. In addition to the administrative burdens we have been 

able to monetize, we must be mindful that permitting authorities 

will incur other burdens, including the significant support and 

outreach activities by permitting staff for the many newly 

permitted sources. We believe that any lower thresholds in this 

timeframe, whether in the PSD and title V applicability levels 

or in the significance level, would give rise to administrative 

burdens that are not manageable by the permitting authorities. 

Although the burdens at the 100,000 tpy CO2e/75,000 tpy CO2e 

levels are steep, we consider them manageable. Step 2 

permitting for GHGs will mostly involve source categories in 

which some sources have traditionally been subject to 

permitting, which should render applying even the new GHG 

requirements more manageable. These source categories include 

fossil fuel-fired power plants, petroleum refineries, cement 

plants, iron and steel plants, and petroleum refineries, in 

addition to other large industrial type source categories. A 

full description of the type of sources that we expect will have 

GHG emissions that exceed the 100,000 tpy CO2 threshold is 

provided in the “Technical Support Document for Greenhouse Gas 

Emissions Thresholds Evaluation” located in the public docket 

for this rulemaking. In addition, because Step 2 does not begin 
306

until July 1, 2011, permitting authorities have about 14 months 

to prepare for it. 

 In addition, we believe that the sources that will become 

subject to PSD and title V requirements at the 100,000/75,000 

tpy CO2 levels will be able to accommodate the additional costs 

of permitting. For the most part, these sources will be of a 

comparable size and activity level as those sources that are 

already subject to those requirements. 

 Because the administrative burdens at the 100,000/75,000 

level are as heavy as the permitting authorities can reasonably 

be expected to carry, adopting these threshold levels is 

consistent with our legal basis under the “absurd results” 

doctrine. Under this basis, we are reconciling the statutory 

levels with congressional intent by requiring that the PSD and 

title V requirements be applied to GHG sources at levels as 

close as possible to the statutory thresholds, and as quickly as 

possible, in light of costs to sources and administrative 

burdens. 

 Because the administrative burdens at the 100,000/75,000 

level are manageable, we do not believe that higher threshold 

levels are justifiable for Step 2. Specifically, at the 

100,000/100,000 level – which would entail a 100,000 tpy CO2e 

significance level, rather than a 75,000 tpy CO2e level – 
307

permitting sources would need to handle only 20 additional 

modifications beyond current levels, and thus would not incur 

substantial additional costs. By the same token, we disagree 

with commenters who suggested that we needed to set permanent 

GHG permitting thresholds for major sources at a rate equivalent 

to the amount of GHG that would be emitted by conventional 

pollutants at the 100 and 250 tpy level in order to meet the 

legal bases of the “absurd results” and “administrative 

necessity” doctrines. These levels would likely be well above 

300,000 tpy CO2e, depending on fuel types and assumptions 

regarding the relative emissions of GHGs compared to the 

conventional pollutants. Our data show that none of the levels 

above 100,000/75,000 would result in significant increases in 

administrative burdens. As a result, establishing these levels 

would not apply PSD or title V requirements to GHG sources as 

quickly as possible, and thus would not be consistent with our 

approach in the Tailoring Rule. 

We estimate that facilities meeting the Step 2 major source 

applicability thresholds account for approximately 67 percent of 

total national stationary source GHG emissions. Many commenters 

felt that this should be an important basis for our selection of 

a threshold, stating that there is no significant loss in GHG 

emissions coverage of source categories at the 100,000 tpy CO2
308

threshold, and in some cases arguing that as a result, we should 

set the level even higher. We agree that it is important that 

the coverage in step 2 represents 86 percent of the coverage at 

full implementation of the statutory 100/250 thresholds. 

c. Rationale for EPA’s Plan Beyond Step 2 

 EPA commits that after Step 2, EPA will begin another 

rulemaking in 2011 and complete it by July 1, 2012, and in that 

rulemaking take comment on a further phase-in of GHG sources for 

PSD and title V applicability (Step 3). However, under this 

rule, in no event will EPA apply PSD or title V to sources below 

the 50,000 tpy CO2e levels prior to 2016. In addition, EPA 

commits to conduct a study, to be concluded by April 30, 2015, 

evaluating the status of PSD and title V applicability to GHG 

sources, and, based on the study, complete a rulemaking by April 

30, 2016 that addresses another round of a phase-in. 

(1) Proposal 

In our proposal, we noted that following implementation of 

the first phase of PSD and title V applicability to GHG sources, 

generally at the 25,000 tpy CO2e threshold, additional action 

would be required over time to assure full compliance with the 

statute. We did not establish more steps in the schedule, but 

we did commit to conduct a study, to be completed by 5 years 

after promulgation, evaluating the status of PSD and title V 
309

applicability to GHG sources, and, based on the study, complete 

a rulemaking by 6 years after promulgation that addressed an 

additional step of the phase-in. 

(2) Comments 

 A number of commenters supported the proposal’s overall 

approach to phase in the permitting of GHGs, mainly because this 

approach will allow permitting of the largest sources of GHGs 

immediately while collecting more information about smaller 

sources and more fully considering streamlining options for 

subsequent phases. Many of these commenters made clear that 

they do not support implementation of the statutory 100/250 tpy 

thresholds, even through a phase-in approach. On the other 

hand, one commenter asserted that EPA has failed to demonstrate 

that it needs 6 years to study and implement NSR and title V for 

sources emitting less than 25,000 tpy. The commenter contends 

that EPA has not analyzed, among other things, what combined 

effect the full implementation of its streamlining proposals in 

the 15 months before the due-date for title V permit 

applications would be to reduce the cost, complexity, and number 

of title V permit applications that would have to be submitted. 

(3) Rationale for Further Steps 

We agree with commenters who support a phased-in approach 

to the GHG Tailoring Rule. Our final action reflects a multi-
310

step process that we believe will facilitate a manageable 

expansion of PSD and title V applicability, as appropriate, to 

GHG-emitting sources. In our final action, we have established 

the initial two steps of a multi-step phase-in of lower 

threshold applicability with a commitment to take further 

regulatory activity to consider adopting lower thresholds. We 

believe this process will provide substantial opportunity for 

permitting authorities and sources to establish enough 

experience and information, and to provide significant realworld feedback to EPA, so as to better inform decisions on 

future phase-in steps. 

With this overall phase-in approach in mind, in this final 

rule, EPA includes an enforceable commitment to undertake a 

notice-and-comment rulemaking that would begin with a 

supplemental notice of proposed rulemaking that we expect to be 

issued in 2011 and that we commit will be finalized in 2012. 

The notice will propose or solicit comment on further reductions 

in the applicability levels. This rulemaking will take effect 

by July 1, 2013 and therefore, in effect, constitute Step 3. In 

this action, we are committing to a rulemaking for Step 3, but 

are not promulgating Step 3, because it is important to allow 

EPA and the permitting authorities to gain experience permitting 

sources under Steps 1 and 2, and to allow time to develop 
311

streamlining methods, before attempting to determine what would 

be the next phase-in levels for PSD and title V applicability. 

While committing to future action, we do not decide in this rule 

when the phase-in process will ultimately end, or at what 

threshold level, because all that depends on uncertain variables 

such as our progress in developing streamlining approaches and 

on permitting authorities’ progress in developing permitting 

expertise and acquiring more resources. We may continue the 

phase-in process with further rulemaking(s) after 2016. 

Alternatively, we may make a final determination through future 

rulemaking that, under a Chevron analysis, accounting for the 

“absurd results” doctrine, PSD and/or title V do not apply to 

GHG sources that, while small and relatively inconsequential in 

terms of GHG contribution, are above the statutory tonnage 

thresholds for these programs, and thereby end the phase-in 

process. 

In addition, in this action, we are determining that in no 

event – whether through Step 3 or a subsequent step – will we 

apply PSD or title V to sources at the 50,000/50,000 level or 

lower prior to May 1, 2016. We have several reasons for making 

this determination at this time. Most importantly, our 

examination of the expected burdens to the permitting 

authorities of applying PSD and title V to GHG sources convinces 
312

us that extending the permitting programs to sources at or below 

the 50,000/50,000 level within 6 years of promulgation would 

result in prohibitively heavy burdens. This threshold option 

would result in close to 2,000 additional annual PSD permitting 

actions per year over the current program and more than 1,000 

over Step 2, including both new construction and modifications. 

For title V, we estimated an increase of over 1,000 new title V 

permits (all newly permitted sources because of GHG emissions) 

over 2,000 permit revisions per year over the current program, 

and about 980 new title V permits and 900 permit revisions more 

than the Step 2 amounts. 

These increases, which could occur between 2013 and 2016 

under our approach depending on the outcome of the step 3 

rulemaking, represent very substantial additions to the 

permitting program. In terms of cost, we estimate that these 

additional actions would result in a $73 million per year 

increase in joint PSD and title V program costs over the current 

programs – which is almost a doubling of costs – and $42 million 

annual cost increase over Step 2 for the current programs. We 

believe that it would take permitting authorities some time to 

adjust to this workload. This is particularly true because at 

the 50,000/50,000 tpy CO2e level, smaller sources – including 

ones not previously subject to permitting requirements – will 
313

become subject to PSD and title V. It will take some time for 

both the permitting authorities and the sources to absorb these 

new obligations. 

Importantly, the next lower cut-off – below 50,000 for the 

major threshold level – is the 25,000/25,000 level. For the 

reasons discussed previously, this level is clearly not 

manageable within the first 6 years after this action. This 

applicability level would bring in over 7,000 sources that would 

be newly subject to title V permitting and result in close to 

10,000 new PSD permitting actions. This would result in a 380 

percent increase over current program costs for PSD and title V 

to run these programs. Based on comments we received from state 

and local permitting agencies on our proposed Tailoring Rule, 

these levels of permitting activities would far exceed the 

administrative capabilities of the permitting agencies for at 

least the near future. Thus, the 6-year exclusion is necessary 

to provide these agencies and their permittees certainty that 

this will not occur. 

We recognize that at present, we do not have data that 

would allow us to compile administrative burden estimates for 

specific levels between the 50,000/50,000 and 25,000/25,000 tpy 

CO2e levels we assessed. However, it is clear that the burdens 

begin to rise sharply below the 50,000/50,000 level. To 
314

reiterate, the combined PSD and title V administrative burdens 

at the 50,000/50,000 tpy CO2e level cost almost twice as much as 

the current programs, but the burdens at the 25,000/25,000 level 

cost almost four times as much as the current programs. As a 

result, we conclude that dropping the level below 50,000/50,000 

too soon would quickly expose the permitting authorities to 

unacceptably high burdens. 

As a further reason for concluding that we will not reduce 

thresholds beyond 50,000/50,000 tpy CO2e during the first 6 

years, we recognize that the PSD permitting process in 

particular carries important ramifications for the permitting 

authorities and the affected sources. If we have underestimated 

the permitting burden or the ability of states to respond to 

their additional workload, then permitting backlogs will result, 

and PSD permit issuance will be delayed, and sources seeking a 

PSD permit will not be able to construct or modify. If this 

were to happen on a large enough scale, it could have 

potentially serious consequences for the national economy. 

Moreover, we need to be mindful that the best information 

we currently have as to permitting authority burdens represents 

a national average, as described previously. Our information at 

the individual state and local level, where permitting occurs, 

is not as robust. Accordingly, we recognize that a particular 
315

state may encounter permitting costs that are higher than 

average, and this may result in permitting backlogs in that 

state, with the consequence that sources in that state will face 

long delays in constructing or modifying. Similarly, even if a 

particular state’s costs are in line with the national average, 

that state may not be able to find the additional resources to 

cover those costs as readily as other states. For this reason, 

too, sources in that state could face long delays in 

constructing or modifying. 

Beyond the administrative burdens to permitting 

authorities, we recognize that the costs of PSD and title V 

permitting to sources may be high, and we are not inclined to 

impose them at this time on sources smaller than the 

50,000/50,000 tpy CO2e threshold. At that level, the permitting 

programs will apply to a significant number of newly permitted 

sources, including a variety of small manufacturing, commercial 

and residential categories. The next level that we have 

analyzed is the 25,000/25,00 tpy CO2e threshold. At that level, 

more than 7,000 more sources would become subject to PSD each 

year – almost all due to modifications – and another 4,000 

sources would become subject to title V each year. These 

sources would be even smaller than those that already will have 

become subject to PSD and title V due to their GHG emissions. 
316

We do not think it reasonable to subject more of those types of 

sources, and smaller ones, to permitting costs within the next 6 

years. 

Finally, we note that moving from a 50,000 tpy CO2e 

threshold to 25,000 tpy CO2e will increase the emissions coverage 

of GHG stationary sources from 70 percent to 75 percent 

nationwide, which we consider to be a relatively small amount. 

 We recognize that our progress in developing streamlining 

methods will be a key determinant to the ability of permitting 

authorities to administer, and sources to comply with, PSD and 

title V at GHG emission levels below 50,000/50,000. Although we 

commit to pursue streamlining, we cannot predict our progress. 

This uncertainty may be problematic for stakeholders, primarily 

permitting authorities and industry. That is, permitting 

authorities will face uncertainty in planning the scope of their 

programs over the next few years, and industry will face 

uncertainty as to what new construction projects and 

modifications will be subject to PSD for GHGs. By determining 

now that for the next 6 years we will not impose PSD 

requirements below a floor at the 50,000/50,000 level, we add a 

measure of needed certainty. 

We also recognize that selecting a level that is too low or 

keeping a level for too long means that some sources may 
317

construct or modify without implementing BACT level controls, 

and this could result in additional emissions of GHGs. We need 

to be vigilant and to protect against this outcome. Even so, 

all things considered, we believe that our determination not to 

apply the PSD or title V permitting requirements to sources 

below the 50,000/50,000 tpy CO2e level for the first 6 years also 

represents a reasonable balancing of protection of the 

environment with promotion of economic development. This type 

of balancing is consistent with our authority under the PSD 

provisions. 

We also raised the issue of “hollow” or “empty” permits in 

discussing our rationale for why it may make sense to delay 

title V permitting under our proposal. We were concerned that 

many title V permits for GHG sources would contain no applicable 

requirements, and their issuance would therefore be of little 

value and would not be the best use of scarce resources. 

Several commenters agreed that implementing title V for GHG 

will, at least initially, require empty permits to be issued to 

GHG sources because such sources will not be subject to 

“substantive” requirements, and that this would not be the best 

use of scarce resources. 

 We believe that the amount of resources that would be spent 

and the limited value that would from, empty permits does 
318

warrant consideration under the Chevron analysis, take account 

of the “absurd results” doctrine. Therefore, we may consider 

the role of empty permits when we undertake future rulemaking. 

However we believe the issue of empty permits has limited 

relevance to the first two steps of the phase in that we are 

promulgating in this rule. During step 1, permitting for GHGs 

is only required if the source is otherwise subject to 

permitting for its emissions of non-GHGs, meaning that those 

sources will be subject to existing substantive applicable 

requirements for non-GHGs (e.g., NSPS, MACT, and SIP 

requirements, including PSD). Thus, there should be few, if 

any, empty permits, at least with respect to applicable 

requirements for non-GHGs, during step 1. For step 2, it is 

possible that sources that become subject to title V 

requirements for GHG emissions may not be subject to other 

requirements, but our assessment suggests that this will be 

rare. We estimate that virtually all of the 550 newly-major 

sources in step 2 will be subject to applicable requirements 

under the CAA because they are from categories that have been 

traditionally subject to regulations, such as smaller industrial 

sources from already regulated categories, large landfills, and 

oil/gas/coal production. Even the approximately 50 newlysubject commercial sources in step 2, which we estimate to be 
319

comprised of very large hospitals, are likely to be covered by 

standards for medical waste incinerators. Thus, we project few, 

if any, empty permits during step 2. 

In later stages of implementation (e.g., prospective step 

3) or in the event that we permit smaller, non-traditional 

sources of GHGs that have never otherwise been subject to major 

source permitting, there would be a greater potential for empty 

permits to be issued under title V. Cognizant of this, we 

intend to further explore in the rulemaking for step 3 empty 

permit theories under the “absurd results” rationale that may 

serve to permanently narrow the scope of title V to exclude 

sources that would potentially be required to obtain an empty 

permit due to GHG emissions. 

In this action, EPA is also finalizing its proposal to 

commit to conduct an assessment of the threshold levels – to be 

completed in 2015, 5 years after this action -- that will 

examine the permitting authorities’ progress in implementing the 

PSD and title V programs for GHG sources as well as EPA’s and 

the permitting authorities’ progress in developing streamlining 

methods. We further commit to undertake another round of 

rulemaking -- beginning after the assessment is done, and to be 

completed by April 30, 2016 – to address smaller sources. 
320

We disagree with the commenter who asserted that we do not 

need 6 years to study and implement PSD and title V for smaller 

sources. As we discussed in the proposal, and reiterate in this 

final action, we do not have sufficient information at this time 

to determine the applicability and effectiveness of the various 

permitting streamlining techniques. For reasons discussed in 

more detail in section V.E.1 regarding streamlining, we are not 

now able to determine how such techniques will be implemented or 

whether they will prove viable or effective. We agree with the 

commenter that these measures may reduce the scope, cost, and 

complexity of these programs, but there is considerable 

uncertainty as to the extent of this effect. We do commit in 

this action to fully investigate, propose, and evaluate these 

permit streamlining techniques to determine where they may have 

applications, how they would be applied, and whether they can 

withstand legal challenge. Even for those techniques that may 

ultimately be deemed viable there is a significant time period 

necessary for rulemaking and state adoption, all of which could 

take up to 3 years or more. We also note that we will be 

required to complete our study of the effectiveness of these 

techniques within 5 years, meaning that, in order to complete it 

in time, we will essentially need to begin the study as soon as 

relevant data are starting to become available. Finally, the 
321

sixth year, in which EPA must complete rulemaking, requires 

proposal and promulgation of a rule within 1 year, which is an 

ambitious schedule. Therefore we believe that 6 years is an 

ambitious schedule, and appropriate for this type of effort. We 

also have received a substantial number of comments from 

permitting authorities that agreed with our 5-year timeframe, or 

a greater timeframe, to get more prepared for permitting smaller 

sources. 

d. Other Comments on “Absurd Results” Doctrine 

 We received other comments on our application of the 

“absurd results” doctrine, which we respond to in the Response 

to Comments document. One comment was overarching, and so we 

respond to it here: Some commenters argued that the “absurd 

results” doctrine could not be applied because EPA had other 

approaches for resolving the problems raised by applying PSD to 

GHG sources. In particular, the commenters insisted that we 

were not obligated to issue the light-duty vehicle rule, and had 

we not done so, we would not have triggered PSD; or at the 

least, we could have delayed issuing the light-duty vehicle rule 

for some period of time, during which we could develop 

streamlining measures and permitting authorities could ramp up 

resources and thereby minimize the need for tailoring when we 

did promulgate the light-duty vehicle rule. 
322

 These commenters also commented during the light-duty 

vehicle rulemaking that we were not obligated to conduct that 

rulemaking, or to conduct it at the time that we did. We 

believe that our response there suffices for here, as well: 

 Some of the comments relating to the stationary 

source permitting issues suggested that EPA should 

defer setting GHG standards for new motor vehicles to 

avoid ... [adverse] stationary source permitting 

impacts. EPA is issuing these final GHG standards for 

light-duty vehicles as part of its efforts to 

expeditiously respond to the Supreme Court’s nearly 

three year old ruling in Massachusetts v. EPA, 549 

U.S. 497 (2007). In that case, the Court held that 

greenhouse gases fit within the definition of air 

pollutant in the Clean Air Act, and that EPA is 

therefore compelled to respond to the rulemaking 

petition under section 202(a) by determining whether 

or not emissions from new motor vehicles cause or 

contribute to air pollution which may reasonably be 

anticipated to endanger public health or welfare, or 

whether the science is too uncertain to make a 

reasoned decision. 

 The Court further ruled that, in making these 

decisions, the EPA Administrator is required to follow 

the language of section 202(a) of the CAA. The Court 

stated that under section 202(a), "[i]f EPA makes [the 

endangerment and cause or contribute findings], the 

Clean Air Act requires the agency to regulate 

emissions of the deleterious pollutant." 549 U.S. at 

534. As discussed above, EPA has made the two 

findings on contribution and endangerment. 74 FR 66496 

(December 15, 2009). Thus, EPA is required to issue 

standards applicable to emissions of this air 

pollutant from new motor vehicles. 

 The Court properly noted that EPA retained 

"significant latitude" as to the "timing ... and 

coordination of its regulations with those of other 

agencies" (id.). However it has now been nearly three 

years since the Court issued its opinion, and the time 

for delay has passed. In the absence of these final 

standards, there would be three separate federal and 

state regimes independently regulating light-duty 
323

vehicles to increase fuel economy and reduce GHG 

emissions: NHTSA’s CAFE standards, EPA’s GHG 

standards, and the GHG standards applicable in 

California and other states adopting the California 

standards. This joint EPA-NHTSA program will allow 

automakers to meet all of these requirements with a 

single national fleet because California has indicated 

that it will accept compliance with EPA’s GHG 

standards as compliance with California's GHG 

standards. 74 FR at 49460. California has not 

indicated that it would accept NHTSA’s CAFE standards 

by themselves. Without EPA’s vehicle GHG standards, 

the states will not offer the federal program as an 

alternative compliance option to automakers and the 

benefits of a harmonized national program will be 

lost. California and several other states have 

expressed strong concern that, without comparable 

federal vehicle GHG standards, the states will not 

offer the federal program as an alternative compliance 

option to automakers. Letter dated February 23, 2010 

from Commissioners of California, Maine, New Mexico, 

Oregon and Washington to Senators Harry Reid and Mitch 

McConnell (Docket EPA-HQ-OAR-2009-0472-11400). The 

automobile industry also strongly supports issuance of 

these rules to allow implementation of the national 

program and avoid “a myriad of problems for the auto 

industry in terms of product planning, vehicle 

distribution, adverse economic impacts and, most 

importantly, adverse consequences for their dealers 

and customers.” Letter dated March 17, 2010 from 

Alliance of Automobile Manufacturers to Senators Harry 

Reid and Mitch McConnell, and Representatives Nancy 

Pelosi and John Boehner (Docket EPA-HQ-OAR-2009-0472-

11368). Thus, without EPA’s GHG standards as part of 

a federal harmonized program, important GHG reductions 

as well as benefits to the automakers and to consumers 

would be lost.165 In addition, delaying the rule would 

impose significant burdens and uncertainty on 

automakers, who are already well into planning for 

production of MY 2012 vehicles, relying on the ability 

to produce a single national fleet. Delaying the 

issuance of this final rule would very seriously 

disrupt the industry’s plans 

Instead of delaying the LDV rule and losing the 

benefits of this rule and the harmonized national 

program, EPA is directly addressing concerns about 
324

stationary source permitting in other actions that EPA 

is taking with regard to such permitting. That is the 

proper approach to address the issue of stationary 

source permitting, as compared to delaying the 

issuance of this rule for some undefined, indefinite 

time period. 

75 FR____ (May 7, 2010) (footnote omitted). 

9. “Administrative Necessity” Basis for PSD and Title V 

Requirements in Tailoring Rule 

EPA believes that the “administrative necessity” doctrine, 

within the Chevron framework, also justifies this rulemaking. 

Applying the applicability requirements of the PSD and title V 

programs according to a literal reading of their terms (as EPA 

has narrowed them in the past through interpretation) to GHG 

sources beginning on the January 2, 2011 date that regulation of 

GHGs takes effect would sweep so many sources into those 

programs as to render the programs impossible for the permitting 

authorities to administer. Although streamlining the PSD and 

title V programs offers some promise to improve the 

administrability of the programs, given the time needed to 

implement such streamlining, the step-by-step expansion of PSD 

and title V requirements to GHG sources that we are promulgating 

is the most that the permitting authorities can reasonably be 

expected to administer. 

This section discusses the application of the 

“administrative necessity” doctrine. Our views concerning this 
325

doctrine remain similar to what we said at proposal, except that 

in this rulemaking we place the doctrine more clearly in the 

Chevron analytical framework, we revised our assessment of the 

administrative burdens due to new analysis we have conducted and 

information we have received since proposal, and we make certain 

revisions we made to the tailoring approach. This analysis and 

information, as well as the revisions to the tailoring approach, 

have already been presented previously, in the discussion of the 

“absurd results” basis. In addition, it is not necessary to 

reiterate the lengthy discussion of the “administrative 

necessity” doctrine that we included in the proposal or the 

factual data presented previously; as a result, this section 

briefly and highlights the conclusions we have reached about the 

application of this doctrine. 

 As noted previously, under the PSD and title V 

applicability provision – read literally, as we have long 

interpreted them -- EPA’s recent promulgation of the light-duty 

vehicle rule will trigger the applicability of PSD and title V 

for GHG sources at the 100/250 tpy and 100 toy threshold levels, 

respectively, as of January 2, 2011. This is because PSD 

applicability hinges on the definition of “major emitting 

facility” and title V applicability hinges on the definition of 

“major sources,” and those terms, read literally, and under 
326

EPA’s long-standing narrowing interpretation, apply PSD and 

title V, respectively, to sources of any air pollutant that is 

subject to regulation under another provision of the CAA. EPA’s 

promulgation of the light-duty vehicle rule means that GHGs will 

become subject to regulation on the date that the rule takes 

effect, which will be January 2, 2011. 

 Absent tailoring, the January 2, 2011 trigger date for GHG 

PSD applicability will give rise to see an extraordinarily large 

number of PSD permitting actions – we estimate more than 81,000 

per year – representing an increase of almost 300-fold over the 

current 280 PSD permitting actions each year. In addition, over 

6 million sources will become subject to title V, an increase of 

more than 400-fold over the 14,700 sources that currently are 

subject to title V. The permitting authorities will find it 

impossible to administer programs of these sizes as of that 

date. 

 All this results from a literal application of the PSD and 

title V applicability provisions to GHG sources. However, under 

Chevron, we must interpret and apply statutory requirements on 

the basis of congressional intent. Although the literal meaning 

of the statutory provisions is the first and generally the best 

indicator of congressional intent, there are cases in which that 

is not so. As discussed previously, we believe that as a 
327

general matter, statutory directives should be considered to 

incorporate Congress’s intent that they be administrable, and we 

believe that this proposition is implicit in the “administrative 

necessity” doctrine that the D.C. Circuit has established and 

that we believe applies here. See Alabama Power v. Costle, 636 

F.2d 323, 356-57 (D.C. Cir. 1980). This doctrine authorizes EPA 

to undertake a process for rendering the PSD and title V 

requirements administrable. Indeed, the Court in Alabama Power 

established this doctrine specifically in the context of the PSD 

provisions, including, in particular, the modification 

provision. As noted elsewhere, the Court held that EPA may 

“consider the administrative burden” associated with applying 

PSD for emissions increases, and establish significance levels 

designed to avoid “severe administrative burdens on EPA, as well 

as severe economic burdens” on sources. Id. at 405. 

 As we said in the proposal, read the caselaw to establish a 

three-step approach for implementing the “administrative 

necessity” doctrine: An agency is not required to adhere to 

literal statutory requirements if the agency, as the first step, 

makes every effort to adjust the requirements within the 

statutory constraints, but concludes with justification – at the 

second step – that it would be impossible to comply with the 

literal reading of the statute. Under those circumstances, the 
328

agency may – at the third step – develop what is in effect a 

compliance schedule with the statutory requirements, under which 

the agency will implement the statute as much as 

administratively possible and as quickly as administratively 

possible. See 74 FR 55,315/1 – 55,316/3. 

a. First Step of the “Administrative Necessity” Analysis: 

Streamlining 

 In the proposed rulemaking, EPA discussed at length the 

prospect of streamlining both PSD and title V. EPA described 

“several potentially useful tools available in the streamlining 

toolbox for the PSD permitting threshold level, the PSD 

significance level, and the title V permitting threshold,” 

specifically – 

For the PSD permitting threshold level and 

significance level, there are at least three such 

tools: The first is interpreting the definition of 

"potential to emit" so that the amount of a source's 

emissions that counts in determining whether it 

qualifies as a major source and therefore is above the 

permitting threshold requirements is closer to the 

amount of its emissions when it is in actual 

operation, rather than the amount of emissions that 

the source would emit if it were operating 

continuously. Narrowing the definition of PTE is a 

potentially extremely important tool in this context 

because identifying the amount of a source's emissions 

as closer to its actual emissions in this manner would 

mean that very large numbers of residential and 

commercial sources would have significantly lower 

emissions and would fall below the statutory threshold 

requirements for triggering PSD. Second, EPA believes 

it may be able to develop programs involving general 

permits, under which large numbers of similarly 
329

situated sources would each be covered by essentially 

the same permit established through a regulatory 

action by the permitting authority. This approach 

could achieve economies of scale and thereby reduce 

administrative burden. Third, EPA believes it may be 

able to streamline the single most time-consuming 

element of the PSD permit program, which is the 

determination of BACT as required under CAA 

§165(a)(4), by establishing presumptive BACT levels 

for certain source categories that comprise large 

numbers of sources. As for title V, as discussed 

below in detail, EPA believes that defining "potential 

to emit" to reflect more closely a source's actual 

operation and developing a program of general permits 

could streamline the administration of title V 

permits. 

74 FR 55,315 col. 2-3. 

 At proposal we stated that we would, and we still commit 

to, vigorously pursue development of these streamlining 

measures, and, as indicated in our discussion of streamlining 

methods in section V.E.1 and in response to comments, we have 

already begun developing those measures. For example, as 

described elsewhere, we have done much work – both with 

stakeholders and in-house -- to begin to develop recommendations 

for what controls would qualify as BACT for various industries. 

This work is important as a foundation for developing 

presumptive BACT, which is a potentially quite efficient 

streamlining measure. 

 However, it is not possible for us or the state and local 

permitting authorities to develop and implement streamlining 
330

techniques by the time that PSD and title V are triggered for 

sources emitting GHGs – January 2, 2011 -- or shortly 

thereafter. Developing streamlining methods would entail 

acquiring more information about the affected industry, may 

entail rulemaking, and would likely entail some type of public 

review of proposals for streamlining even if not done through 

rulemaking. As discussed in section VI.E, we do not expect that 

we could complete all those steps for meaningful streamlining 

measures within 2 years. 

b. Second Step of the “Administrative Necessity” Analysis: 

Demonstration of Administrative Impossibility 

 With no streamlining measures available at the time that 

PSD and title V would apply to sources of GHGs or shortly 

thereafter, under the second step of the “administrative 

necessity” analysis, we must determine whether implementation of 

the statutory requirements at that time would be 

administratively impossible for the permitting authorities. We 

are mindful that the D.C. Circuit has cautioned that this 

showing is a high hurdle. See 74 FR 55,317/3. 

 Even so, we believe there is no question that a literal 

application of the PSD and title V programs to GHG sources as of 

January 2, 2011 would be flatly impossible for the state and 

local permitting authorities to administer for at least an 
331

initial period of time.41 The key facts have been recounted 

previously, and no more than a brief recitation is necessary 

here. On the PSD side, annual permit applications would 

increase by over 300-fold, from 280 to 80,000; costs to the 

permitting authorities would increase more than 100-fold, from 

$12 million to $1.5 billion; and the permitting authorities 

would need to hire, train, and manage 9,772 FTEs. For title V, 

total permit applications would increase by over 400-fold, from 

14,700 to 6.1 million; costs to the permitting authorities would 

increase from $62 million to $21 billion; and the permitting 

authorities would need to hire, train, and manage 229,118 FTEs. 

 We have elaborated upon these burdens elsewhere in this 

notice. They bespeak an impossible administrative task. It is 

not hyperbole to say that if these administrative 

responsibilities are not considered impossible within the 

meaning of the “administrative necessity” doctrine, then it is 

difficult to imagine what would be considered impossible. 

c. Third Step of the “Administrative Necessity” Analysis: 

Tailoring 

 41 We recognize that in a few states, we are the permitting 

authority. We do not think that this changes the calculation of 

administrative burdens. We do not believe that we could 

reasonably be expected to adjust our budget to accommodate the 

large new permitting burdens, and even if we could, the 

administrative burdens would remain in most of the rest of the 

nation where it is the state or local agencies that bear 

permitting responsibility. 
332

 Under the third step of the “administrative necessity” 

analysis, we must demonstrate that the steps we intend to take 

towards implementation of the statutory requirements are the 

most that can be done during the indicated time frames, in light 

of administrative resources. In this manner, we adhere most 

closely to the statutory requirements. See 74 FR 55318/2. This 

amounts to establishing a schedule for phasing in PSD and title 

V applicability to GHG sources. Because this step is based on 

the administrative resources of the permitting authorities, our 

analysis is similar, and leads to the same conclusions, as we 

described previously concerning the “absurd results” basis. 

That is, we believe that our tailoring approach – including step 

1, to be implemented as of January 2, 2011; step 2, to be 

implemented as of July 1, 2011; the additional rulemaking that 

we commit to finalize by July 1, 2012, and that will address 

further threshold reductions as a step 3; the study and 

subsequent rulemaking to address smaller sources by April 30, 

2016; and the determination not to lower the threshold below 

50,000/50,000 tpy CO2e before April 30, 2016 at the earliest -- 

is the most that we can do to expand the PSD and title V 

programs, based on administrative resources and the information 

we currently have about the prospects for streamlining and 

increasing permitting resources. 
333

 As noted preciously, at some point in the process of 

additional rulemaking, we may conclude under the “absurd 

results” doctrine that we will not apply PSD or title V to GHG 

sources below a certain size level. The same conclusion may be 

supportable under the “administrative necessity” doctrine if we 

decide, based on the information available to us, that even with 

all of the streamlining that we are able to accomplish and even 

with a significant expansion of permitting resources, it may not 

be administratively feasible to implement PSD or title V to 

sources below that level. See Alabama Power v. Costle, 636 F.2d 

at 358 (acknowledging, in discussing the “administrative 

necessity” doctrine, that “[c]ategorical exemptions from the 

clear commands of a regulatory statute [are] sometimes 

permitted,” although emphasizing that such exemptions “are not 

favored”). 

 In addition, as noted above, in a subsequent rulemaking, we 

may conclude that title V should not apply to GHG sources with 

“empty permits,” under the “absurd results” doctrine. The basis 

for this conclusion could be a determination that (i) although 

the applicability provisions apply by their terms to sources on 

the basis of their emissions, and without regard to whether the 

sources would hold empty permits, those provisions cannot be 

read literally under the “absurd results” doctrine; and (ii) it 
334

is not clear whether Congress intended that title V apply to 

such sources, and EPA has reasonably determined, under Chevron

step 2, that title V does not. If we come to that conclusion, 

then, at that point in time, the “administrative necessity” 

doctrine would remain relevant for title V purposes only if is 

necessary, for administrative reasons, to phase-in the 

application of title V to GHG sources that have applicable 

requirements, and that therefore do not have empty permits. 

This is because the “administrative necessity” doctrine is 

relevant only when a statutory directive, read literally, 

imposes impossible administrative obligations, and Congress may 

be presumed to have intended that the directive be 

administrable. The “administrative necessity” doctrine would 

not come into play if it is concluded either that under the 

“absurd results” doctrine Congress did not intend the statutory 

directive or that, under that doctrine, Congress’s intent was 

not clear and EPA reasonably decided that the directive does not 

apply. 

10. “One-Step-at-a-Time” Basis for Tailoring Rule 

 In addition to the “absurd results” and “administrative 

necessity” doctrines, the “one-step-at-a-time” judicial 

doctrine, within the Chevron framework, supports EPA’s Tailoring 

Rule. The caselaw under this doctrine, described previously, 
335

indicates that the doctrine justifies an agency’s step-by-step 

approach under the following circumstances or conditions: (i) 

the agency’s ability to comply with a statutory directive 

depends on facts, policies, or future events that are uncertain; 

(ii) the agency has estimated the extent of its remaining 

obligation; (iii) the agency’s incremental actions are 

structured in a manner that is reasonable in light of the 

uncertainties; and (iv) the agency is on track to full 

compliance with the statutory requirements. EPA’s tailoring 

rule fulfills each of those four. 

 First, as the D.C. Circuit stated in National Association 

of Broadcaster v. FCC, 740 F.2d 1190, 1210 (D.C. Cir. 1984) 

(“National Association of Broadcasters”), incremental agency 

action is most readily justifiable “against a shifting 

background in which facts, predictions, and policies are in flux 

and in which an agency would be paralyzed if all the necessary 

answers had to be in before any action at all could be taken.” 

Those circumstances are present here, and so is that fact that 

the task at hand is extraordinarily demanding. As discussed 

previously, EPA and the permitting authorities’ progress in 

implementing the PSD and title V programs for GHG sources will 

depend in large measure on the development of streamlining 

measures and increases in permitting authorities’ resources, and 
336

those things carry some uncertainty and in any event, under the 

best of circumstances, cannot have much impact for at least 

several years. It will take EPA that long to develop 

streamlining measures, and it will take permitting authorities 

that long to begin to raise money and hire and train FTEs. 

 Second, as the Court stated in National Association of 

Broadcasters, “the agency [should] ma[k]e some estimation, based 

upon evolving economic and technological conditions, as to the 

nature and magnitude of the problem it will have to confront 

when it comes to [undertake the remaining steps]” and that 

estimation must be “plausible and flow from the factual record 

compiled.” Id. at 1210. Here, EPA has done this by estimating 

the number of PSD and title V permits and the costs of issuing 

them, and has provided as much information as possible about the 

development of streamlining methods and permitting authority 

resources. 

 Third, again as the Court stated in National Association of 

Broadcasters, it must be “reasonable, in the context of the 

decisions made in the proceeding under review, for the agency to 

have deferred the issue to the future. With respect to that 

question, postponement will be most easily justified when an 

agency acts against a background of rapid technical and social 

change and when the agency’s initial decision as a practical 
337

matter is reversible should the future proceedings yield 

drastically unexpected results.” Id. at 1211. Here, our 

tailoring approach is reasonable in light of changes in 

permitting authority capacity that may occur with the 

development of streamlining methods and increased resources. In 

addition, the first two steps that EPA promulgates today are 

reasonable initial steps that we expect to build on by lowering 

thresholds, as appropriate, in the future. We have no reason to 

suspect that we may need to reverse either of the first two 

steps. Having received and analyzed extensive comment on the 

number of permitting actions to expect and on permitting 

authority resources, we consider it unlikely that we would need 

to establish a higher threshold level than what we have 

established in steps 1 and 2. In addition, if we were to adopt 

an “empty permits” approach for title V, we would not need to 

reverse either of steps 1 and 2, as explained above. 

Finally, as the D.C. Circuit stated in Grand Canyon Air 

Tour Coalition v. F.A.A., 154 F.3d 455, 477-78 (D.C. Cir. 1998), 

the Courts will accept an initial step towards full compliance 

with a statutory mandate, as long as the agency is headed 

towards full compliance, and we believe that the doctrine is 

applicable here. EPA intends to require full compliance with 

the CAA applicability provisions of the PSD and title V 
338

programs, but we believe that in the case of GHG-emitting 

sources, by application of the “absurd results” doctrine or the 

“administrative necessity” doctrine, full compliance with the 

applicability provisions does not necessarily mean full 
339

compliance with the literal terms of those provisions.42 Rather, 

as we have explained elsewhere, in the case of GHG sources, full 

compliance may mean compliance with higher levels that are 

consistent with congressional intent, under the “absurd results” 

doctrine, or that are within the reach of permitting authorities 

in light of their administrative constraints, under the 

“administrative necessity” doctrine. This rulemaking 

constitutes a package of initial steps towards that full 

compliance, and, seen in that light, is supported by the “onestep-at-a-time” doctrine. 

 Even if the doctrine were found to apply only when an 

agency is committed to fully implementing statutory requirements 

according to their literal terms, we believe that the steps we 

promulgate in this notice would be considered valid under the 

one-step-at-a-time doctrine. This is because even if we are 

incorrect about the applicability of the “absurd results” and 

“administrative necessity” doctrines, so that GHG sources are 

required to comply with the literal terms of the PSD and title V 

applicability provisions, the “one-step-at-a-time” doctrine 

would allow PSD and title V applicability to be phased in, and 

 42 For reasons explained elsewhere, our reference to the 

literal terms of the applicability provisions means the literal 

terms of the definition of “major emitting facility” for PSD and 

“major source” for title V, as EPA has narrowed those 

definitions to refer to “any pollutant” that is subject to 

regulation under the CAA. 
340

the first two steps we promulgate in this notice would be upheld 

as reasonable initial steps toward full compliance with the 

literal terms of the CAA. As we have described elsewhere, there 

is little question but that sources and permitting authorities 

cannot reasonably be expected to comply with or implement PSD 

and title V applicability requirements in the near term – by 

January 2, 2011 and July 1, 2011 -- except to the limited extent 

described under steps 1 and 2. Nor is applicability of the PSD 

and title V requirements at levels below 50,000 tpy CO2e 

reasonable before 6 years from promulgation of this rule, as 

discussed elsewhere. If further steps resulting in full 

compliance with the literal terms of the applicability 

provisions of PSD and title V were required, it would be 

reasonable for those steps to occur in the future, as part of 

the rulemaking to be completed by the sixth year after 

promulgation, to which EPA commits itself as part of this 

action, or as part of subsequent actions. See Grand Canyon Air 

Tour, 891 F.2d at 476-77 (upholding agency action as a step 

towards full compliance with statutory mandate when the agency 

expected full compliance to occur some 20 years after the 

deadline in the statute). 

C. Mechanisms for Implementing and Adopting the Tailoring 

Approach
341

In this section, we discuss three issues related to 

adoption of the tailoring approach within our regulations and by 

permitting agencies. The first is the regulatory mechanism for 

implementing the tailoring approach – that is, the specific way 

we are revising the PSD and title V applicability provisions to 

incorporate the tailoring approach – and our rationale. The 

second is the process by which state or local permitting 

authorities may incorporate the tailoring approach into their 

PSD SIP and title V permit programs. Finally, we discuss our 

reasons for delaying action on our proposal to limit approval of 

both SIP-approved PSD programs and title V programs, and we 

request certain information from states on both of their 

programs and their actions in response to this rule. 

In brief, we proposed to exempt sources emitting GHGs below 

certain threshold levels from the definition of the regulatory 

terms “major stationary source” and “major modification” in PSD 

programs and the definition of the regulatory term “major 

source” in title V programs. We further proposed to effectuate 

this change in SIP-approved PSD programs (as included in SIPs) 

and EPA-approved part 70 title V programs by limiting our prior 

approval of those programs to the revised applicability 
342

thresholds for GHGs.43 These changes would have the effect of 

putting the higher thresholds adopted under the Tailoring Rule 

in place in states PSD and title V programs as a matter of 

federal law. However, state commenters expressed concern that 

they would not be able to adopt the Tailoring Rule under state 

laws on an expeditious basis. To address this, our final action 

differs from our proposed rule in the way we incorporate the 

limitations promulgated in this Tailoring Rule into the “major 

stationary source,” “major modification” and “major source” 

definitions. This approach relies on further defining the term 

“subject to regulation” and although this approach is not 

substantively different in effect from the proposed rule, it 

will facilitate more rapid adoption and implementation of the 

Tailoring Rule by states through interpretation of language in 

existing state regulations. We believe these difference are a 

logical outgrowth of our proposed rule. We are also delaying 

action on our proposed limited approval of EPA-approved PSD 

programs and part 70 title programs to determine how each state 

will implement the final rules. 

1. PSD Approach: Background and Proposal 

 43 In the alternative, we also proposed to use our 

110(k)(6) error correction authority to revise SIP-approved PSD 

program. We are also delaying action on this proposal. 
343

Under CAA §165(a), no “major emitting facility” may 

construct or modify unless it receives a preconstruction permit 

that meets the requirements of the PSD program. CAA §169(1) 

defines a major emitting facility as “any ... source[]” in one of 

28 specified source categories that “emit[s], or ha[s] the 

potential to emit, one hundred tons per year or more of any air 

pollutant;” or “any other source with the potential to emit two 

hundred and fifty tons per year or more of any air pollutant.” 

EPA’s regulations replace the term “major emitting facility” 

with the term “major stationary source” and define the term as 

“[a]ny of ... [28 types of] stationary sources of air pollutants 

which emits, or has the potential to emit, 100 tons per year or 

more of any regulated NSR pollutant” or “any stationary source 

which emits, or has the potential to emit 250 tons per year or 

more of a regulated NSR pollutant.” 40 CFR 51.166(b)(1)(i)(a)-

(b). The term “regulated NSR pollutant” is defined to include, 

among other things, “any ... air pollutant that otherwise is 

subject to regulation under the Clean Air Act.” 40 CFR 

51.166(b)(50). Note that the regulatory definition in effect 

interprets the statutory definition more narrowly to read “one 

hundred [or two hundred and fifty] tons per year or more of any 

air pollutant subject to regulation under the Clean Air Act” 

(emphasis added). 
344

Similarly, under the statute, a modification occurs if 

there is a physical change or change in the method of operation 

“which increases the amount of any air pollutant emitted . . .” 

CAA section 165(a), 169(2)(c), 111(a)(4). As with the major 

stationary source definition, we have limited coverage of the 

modification provision to physical changes or changes in the 

method of operation that result a significant net emissions 

increase in emissions of a “regulated NSR pollutant.” 40 CFR 

51.166(b)(2)(i). 

Our proposed rule revised the definition of “major 

stationary source to 1) exempt GHG from the regulated NSR 

pollutants that, if emitted by a source in the 100 or 250 tpy 

quantities, would cause the source to qualify as a “major 

stationary source,” and 2) add a specific threshold at which a 

source that emits a specified quantity of GHGs (at proposal, 

that quantity was 25,000 tpy CO2e) would qualify as a “major 

stationary source.” 74 FR 55,351, proposed 40 CFR 

51.166(b)(1)(i)(a), (b), (d). We also proposed a significance 

threshold, which is the amount of an increase needed to trigger 

PSD for a modification or to require BACT for a new source, at a 

level between 10, 000 and 25,000 tpy CO2e. 74 FR 55351 40 CFR 

51.166(b)(23)(i). 
345

Additionally, we recognized that it may take some time 

before states could change their SIP-approved PSD programs and 

that as a result, absent additional action on our part, GHGemitting sources would remain subject to the 100 or 250 tpy 

thresholds, and subject to a zero significance threshold for 

major modifications as a matter of federal law. To address this 

issue, we proposed to narrow our previous approval of those 

SIPs. The effect of our proposal would be that EPA would have 

approved the SIP PSD programs only to the extent they apply PSD 

and requirements to GHG sources at or above the thresholds 

established in the tailoring rule (which, generally, were 25,000 

tpy CO2e), and EPA would have taken no action on the SIP PSD 

programs to the extent they apply PSD requirements to GHG 

sources below that threshold. We relied on the authority of the 

APA and the general authority of CAA §301 and, in the 

alternative, on the error correction mechanism under CAA section 

110(k)(6). Our limited approval would revise existing EPAapproved SIP PSD programs to authorize permitting under the CAA 

only for GHG sources at the appropriate levels. 

In response to our proposed approach, we received numerous 

comments from state and local permitting agencies expressing 

significant concern. The observed that our proposed approach 

could meet its objectives to avoid applying PSD requirements to 
346

small sources under federal law, but would not succeed in 

avoiding the application of PSD requirements to those small 

sources under state law. The commenters explained that, 

although EPA was changing federal PSD applicability thresholds; 

for GHG-emitting sources to incorporate the tailoring approach, 

and limiting the scope EPA approval of SIPs consistent with 

these thresholds, the state rules containing the originallyapproved SIP thresholds would continue to apply as a matter of 

state law. As commenters explained, for the most part, the laws 

and regulations states adopt to implement federal PSD programs 

mirror EPA’s regulations, so that the state laws, apply PSD to 

sources that emit air pollutants subject to regulation at the 

100/250 tpy threshold. Commenters reasoned that, until the 

states can change their state laws, the 100/250 tpy thresholds 

will continue to apply as a matter of state law, even though the 

higher thresholds apply as a matter of federal law. 

Importantly, these commenters emphasized, their state process 

requires that they promulgate a rulemaking, or in some cases, a 

legislative change, to incorporate the higher thresholds for GHG 

sources in their SIPs. These processes would require many 

months and in some cases as long as 2 years. As a result, 

sources that emit GHGs below the federally established levels in 

the final rule, but at our above the 100/250 tpy levels in state 
347

laws and rules, would still be required to obtain PSD permits 

under state law. As a result, states, in attempting to 

implement state permitting requirements, would be faced with the 

same administrative difficulties that EPA recognized in the 

proposed rule as impossible. Commenters emphasized that this 

situation was untenable. 

In addition to the state comments just described, we 

received comments that took issue with our view that we were in 

effect revising the numerical thresholds for PSD applicability 

as the legal mechanism for the tailoring approach. They 

asserted that in fact, our mechanism consisted of interpreting 

the term “any source” to exclude small GHG-emitting sources. 

Other commenters objected to our proposed mechanism of narrowing 

our previous SIP approval, arguing that this mechanism was 

without legal basis. 

2. Rationale for Our Final Approach to Implementing PSD 

In response to these concerns, we are adding another 

mechanism to implement the tailoring approach for PSD, and that 

is to interpret, within our PSD regulations, the phrase “subject 

to regulation,” as found within the phrase “any regulated NSR 

pollutant,” which, in turn, is part of the definitions of “major 

stationary source” and “major modification.” To implement this 

mechanism, we are codifying in our regulations an interpretation 
348

of “subject to regulation” so that the GHGs emitted by sources 

that fall below the thresholds or scope established in steps 1 

and 2 are not treated as “subject to regulation,” and therefore 

do not trigger PSD for the sources that emit them. 

To understand this approach, it is useful to return to the 

definition of “major stationary source,” which, again, is 

central to PSD applicability. The definition, quoted 

previously, employs the term “regulated NSR pollutant,” which is 

a defined term. The definition incorporates many other elements 

as well (e.g., the 100/250 threshold requirements), but for 

convenience, we quote it as follows: a “major stationary 

source” is “[a]ny ... source[] of air pollutants, which emits, or 

has the potential to emit, [depending on the source category, 

either] 100 [or 250] tons per year or more of any air pollutant 

that is subject to regulation under the Clean Air Act.” 40 CFR 

51.166(b)(1)(i(a)-(b). Applying our definition of “subject to 

regulation” to exclude GHG sources that emit below specified 

thresholds, the definition may not be paraphrased as follows: A 

“major stationary source” is any source of air pollutants, which 

emits, or has the potential to emit, depending on the source 

category, either 100 or 250 tons per year or more of any air 

pollutant subject to regulation under the CAA, except that the 

source’s GHGs are considered to be subject to regulation under 
349

the CAA only the extent indicated under steps 1 and 2 of the 

tailoring rule, e.g., for step 2, only if the source’s GHG 

emissions exceed the threshold established in step 2. We adopt 

the same approach for the definition of the regulatory term 

“major modification.” 

Although EPA is codifying its interpretation of “subject to 

regulation” by revising its regulations, we have been advised 

that states may be able to adopt our approach without having to 

undertake a rulemaking action to revise their SIP regulations or 

without requiring an act of the state legislature. Instead, it 

is our understanding that states may adopt our approach by 

interpreting their SIPs to have the same meaning for the term 

“subject to regulation” that we are including in our regulations 

in this rulemaking. We believe that States can rely on an 

interpretation because we view the term “subject to regulation” 

as open-ended, and therefore amenable to interpretation. This 

is particularly – although not exclusively -- the case in a 

state that has taken the position, or determines now, that the 

state’s definition of “subject to regulation,” or, more broadly, 

“regulated NSR pollutant” or “major stationary source” or “major 

modification, is intended to be interpreted in a way that tracks 

the meanings that EPA has assigned to these phrases. Such 

states can adopt the meaning of “subject to regulation” that we 
350

establish in this rule by January 2, 2011, and thereby avoid the 

situation in which, as a matter of state law, GHG-emitting 

sources above the 100 or 250 tpy thresholds become subject to 

PSD by that date. The following explains our basis for 

concluding that the phrase “subject to regulation” is openended. 

First, we recently stated this position in our 

reconsideration of the Interpretive Memo. On December 18, 2008, 

EPA issued the Interpretive Memorandum, establishing EPA’s 

interpretation of the definition “regulated NSR pollutant” found 

at 40 CFR 52.21(b)(50) EPA intended this memorandum to resolve 

ambiguity in subpart (iv) of this definition, which includes 

“any pollutant that otherwise is subject to regulation under the 

Act.” Specifically, the memorandum stated that EPA will 

interpret the definition of “regulated NSR pollutant” to exclude 

pollutants for which EPA regulations only require monitoring or 

reporting but to include pollutants subject to either a 

provision in the CAA or regulation adopted by EPA under the CAA 

that requires actual control of emissions of that pollutant. 

After reconsidering this interpretation through a formal 

notice-and-comment process, EPA refined its interpretation to 

establish that the PSD permitting requirements will not apply to 

a newly regulated pollutant until a regulatory requirement to 
351

control emissions of that pollutant “takes effect.” 75 FR

17704. Importantly, as stated previously, because the term 

“regulated NSR pollutant” is embedded within the definition of 

“major stationary source,” this interpretation effectively 

defines which major stationary sources are subject to PSD 

permitting. As a result, for example, EPA explained that PSD 

and title V permitting requirements for GHGs will not apply to 

GHGs until at least January 2, 2011, following the anticipated 

promulgation of EPA regulations requiring control of GHG 

emissions under Title II of the CAA. Id. 

 In the RTC document for EPA’s reconsideration of the PSD 

interpretative memorandum, we stated that, 

Absent a unique requirement of state law, EPA believes that 

state laws that use the same language that is contained in 

EPA’s PSD program regulations at 52.21(b)(50) and 

51.166(b)(50) are sufficiently open-ended to incorporate 

greenhouse gases as a regulated NSR pollutant at the 

appropriate time consistent with EPA’s interpretation of 

these regulations (emphasis added). (Docket ID No. EPA-HQOAR-2009-0597-0128). 

Because the SIP provisions that include EPA’s definition of the 

term “subject to regulation” in the reconsideration of the PSD 

interpretive memorandum are “sufficiently open-ended to 

incorporate greenhouse gases as a regulated pollutant,” those 

SIP provisions are also sufficiently open-ended to incorporate 

the further refinement to “subject to regulation” that we make 

in this rulemaking. 
352

 By the same token, EPA has historically interpreted certain 

state SIP-approved programs as sufficiently open-ended such that 

the rules provide for the “automatic assumption for the 

responsibility for review” of new pollutants before the general 

deadline for states to revise their PSD programs. See, e.g., 52 

FR at 24682. Conversely, we have also read federal rules and 

state SIPs to provide for the automatic removal of a pollutant 

when such pollutant is no longer “subject to regulation.” For 

example, the 1990 CAA amendments exempted HAPs listed in Section 

112(b)(1) from the PSD requirements. See CAA §112(b)(6). 

Following passage of the amendments, EPA issued “New Source 

Review (NSR) Program Transitional Guidance“, a memorandum from 

John S. Seitz, Director, Office of Air Quality Planning and 

Standards to Regional Air Division Directors on March 11, 1991. 

In that guidance, EPA interpreted its PSD regulations to 

automatically cease to apply to listed HAPs (with some noted 

exceptions), and implicitly stated that a state with an openended SIP-approved PSD rule could also take the position that 

its SIP rule automatically ceased to regulate HAPs. 

 After reviewing these past practices in the PSD permitting 

program, and EPA’s prior statements regarding pollutants subject 

to the PSD program, we conclude that states with SIP rules that 

contain the same language as used in 40 CFR 52.21(b)(50) or 40 
353

CFR 51.166(b)(49), or that otherwise have sufficiently openended PSD regulations, would be able to implement our Tailoring 

Rule approach to permitting by interpreting their regulations, 

and without needing to promulgate a regulation or seek state 

legislative action. This is particularly – although not 

exclusively -- the case for states that take the position that 

they intend their rules to apply the same meaning as EPA's 

counterpart rules. If states adopt this reading of their 

regulations, GHG sources falling below the specified cutoffs 

would not be emitting pollutants “subject to regulation” within 

the definition of “regulated NSR pollutant” and therefore would 

not be subject to PSD permitting as a major stationary source or 

for making a major modification. 

During our consideration of this action, we participated in 

teleconferences with six state and lone local agency permitting 

authorities to discuss this issue of whether they could 

implement the proposed rule without the need for state law or 

regulations changes or a revision of the provisions of state law 

that are a part of the SIP. [Placeholder: docket # for meeting 

summary] We specifically discussed whether defining the phrase 

“subject to regulation” would better facilitate state 

incorporation of the limitations in this final rule. The state 

and local agencies participating in the calls generally agreed 
354

that defining the phrase “subject to regulation” would, compared 

to our proposed approach, better facilitate state incorporation 

of the limitations in the final rule in states with regulations 

that mirror the existing federal rules, or in states whose rules 

are otherwise sufficiently open-ended to incorporate the 

limitations in the final rule by interpretation. Participants 

from each agency also indicated that their rules contain the 

term “subject to regulation” and that term has not been 

previously interpreted in ways that would preclude adoption of 

EPA’s meaning of the term by interpretation to allow for 

adoption. We therefore concluded it is likely the rules are 

sufficiently open-ended (although some states indicated they may 

elect to pursue rulemaking in addition to interpretation). 

Accordingly, we selected the “subject to regulation” regulatory 

approach as the mechanism for codifying the final rule. 

3. Other Mechanisms 

As just described, we selected the “subject to regulation” 

mechanism because it most readily accommodated the needs of 

States to expeditiously revise – through interpretation or 

otherwise -- their state rules. Even so, it is important to 

recognize that this mechanism has the same substantive effect as 

the mechanism we considered in the proposed rule, which was 

revising numerical thresholds in the definitions of major 
355

stationary source and major modification. Most importantly, 

although we are codifying the “subject to regulation” mechanism, 

that approach is driven by the needs of the states, and our 

action in this rulemaking should be interpreted to rely on any 

of several legal mechanisms to accomplish this result. Thus, 

our action in this rule should be understood as revising the 

meaning of several terms in these definitions, including: (i) 

the numerical thresholds, as we proposed; (ii) the term, “any 

source,” which some commenters identified as the most relevant 

term for purposes of our proposal; (iii) the term, “any air 

pollutant; or (iv) the term, “subject to regulation.” The 

specific choice of which of these constitutes the nominal 

mechanism does not have a substantive legal effect because each 

mechanism involves one or another of the components of the terms 

“major stationary source” -- which embodies the statutory term, 

“major emitting facility” -- and “major modification,” which 

embodies the statutory term, “modification,” and it is those 

statutory and regulatory terms that we are defining to exclude 

the indicated GHG-emitting sources.44 

 44 We also think that this approach better clarifies our 

long standing practice of interpreting open-ended SIP 

regulations to automatically adjust for changes in the 

regulatory status of an air pollutant, because it appropriately 

assures that the tailoring rule applies to both the definition 

of “major stationary source” and “regulated NSR pollutant.” 
356

4. Codification of Interpretive Memo 

As noted previously, we recently affirmed and refined our 

interpretation of the term “subject to regulation” as it applies 

broadly to the PSD program through a formal notice and comment 

process. “Interpretation of Regulations that Determine 

Pollutants Covered by Clean Air Act Permitting Programs,” 75 FR 

17004. In the response to comments for that action, we 

indicated that we may opt to codify our interpretation of the 

term in this tailoring rulemaking. Accordingly, our final rule 

adopts this interpretation to bring additional clarity to our 

rules. Specifically, we are adding a new paragraph to the 

definition of the term “subject to regulation” that contains our 

existing interpretation of that term. We also are moving 

existing exceptions (e.g. section 112 HAPs) to a new paragraph 

within the definition of "subject to regulation". This minor 

reorganization of these regulations is not intended to effect 

any change in how they are to be implemented, but merely 

simplifies and clarifies the regulations by clearly delineating 

different terms and concepts. 

This codification of this interpretation of “subject to 

regulation” from the reconsideration for the PSD Interpretive 

Memo is not necessary to assure the effectiveness of the 

interpretation, and it does not disturb States’ existing 
357

authority to adopt the definition through interpretation of 

their existing rules. The codification does nothing more than 

simplify an clarify the regulatory language. 

5. Delaying Limited Approvals and Request for Submission of 

Information from States implementing a SIP-approved PSD program 

Because we now anticipate that many states will be able to 

implement our tailoring approach through interpretation of the 

term “subject to regulation,” and without the need to revise 

their SIPs, we are delaying further action on our proposal to 

limit our approval of SIPs until we better understand how 

permitting authorities will, in fact, implement our tailoring 

approach. For this purpose, we ask each state to submit a 

letter to the appropriate Regional Administrator no later than 

[INSERT DATE 60 DAYS AFTER PROMULGATION]. In that letter, the 

state should explain whether it will apply EPA’s meaning of the 

term “subject to regulation” and if so, whether the state 

intends to incorporate that meaning of the term through 

interpretation, and without undertaking a regulatory or 

legislative process. If a state must undertake a regulatory or 

legislative process, then the letter should provide an estimate 

of the time needed to adopt the final rules. If a state chooses 

not to adopt EPA’s meaning by interpretation, the letter should 

address whether the state has alternative authority to implement 
358

either our tailoring approach or some other approach that is at 

least as stringent, whether the state intends to use that 

authority. If the state does not intend to interpret or revise 

its SIP to adopt the tailoring approach or such other approach, 

then the letter should address the expected shortfalls in 

personnel and funding that will arise if the state attempts to 

carry out PSD permitting for GHG sources under the existing SIP 

and interpretation. 

For any state that is unable or unwilling to adopt the 

tailoring approach by January 2, 2011, and that otherwise is 

unable to demonstrate adequate personnel and funding, we will 

move forward with finalizing our proposal to limit our approval 

of the existing SIP. Although we received comments questioning 

our authority to limit approval as proposed, using our general 

rulemaking and 110(k)(6) authorities, we are not responding to 

those comments at this time. We will address these comments in 

any final action we take to implement a limited approval. 

In our proposed rule, we also noted that a handful of EPAapproved SIPs fail to include provisions that would apply PSD to 

GHG sources when at the appropriate time. This is generally 

because these SIPs specifically list the pollutants subject to 

the SIP PSD program requirements, and do not include GHGs in 

that list, rather than include a definition of NSR regulated 
359

pollutant that mirrors the federal rule, or because the state 

otherwise interprets its regulations to limit which pollutants 

the state may regulate. At proposal, we indicated that we 

intended to take separate action to identify these SIPs, and to 

take regulatory action to correct this SIP deficiency. 

We ask any state or local permitting agency that does not 

believe its existing SIP provides authority to issue PSD permits 

to GHG sources to notify the Regional Administrator by letter, 

and to do so no later than [INSERT DATE 60 DAYS AFTER 

PROMULGATION]. This letter should indicate whether the state 

intends to undertake rulemaking to revise its rules to apply PSD 

to the GHG sources that will be covered under the applicability 

thresholds in this rulemaking, or alternatively, whether the 

state believes it has adequate authority through other means to 

issue federally-enforceable PSD permits to GHG sources 

consistent with this final rule. For any State that lacks the 

ability to issue PSD permits for GHG sources consistent with 

this final rule, we intend to undertake a separate action to 

issue a SIP call, under CAA section 110(k)(5). As appropriate, 

we may also impose a FIP through 40 CFR section 52.21 to ensure 

that GHG sources will be permitted consistent with this final 

rule. 

6. Title V Programs 
360

 Our final action also differs from the proposal in the 

specific regulatory mechanism by which we tailor the definition 

of “major source” for title V permit programs, but is a logical 

outgrowth of our proposed rule. EPA proposed to implement 

tailoring for GHGs under title V by excluding sources of GHGs 

from the general definition of “major source” under 40 CFR 70.2 

and 71.2, and adding a separate definition of “major source” 

with tailored thresholds for sources of GHGs. In response to 

comments, particularly from states concerned with implementation 

of the proposed approach under state law, EPA is adopting an 

approach in the final rule that 1) amends the definition of 

“major source” by codifying EPA’s longstanding interpretation 

that applicability for a “major stationary source” under CAA 

sections 501(2)(B) and 302(j) and 40 CFR 70.2 and 71.2 is 

triggered by sources of pollutants “subject to regulation,” and 

2) adding a definition of “subject to regulation.” Further, we 

are delaying our action to move forward with limiting our 

previous approval of existing state part 70 programs. 

 We finalize this alternative approach to address concerns 

similar to those we received with respect to state 

implementation of SIP-approved PSD programs. Specifically, we 

received comments that the mechanism we proposed would not 

address the significant administrative and programmatic 
361

considerations associated with permitting GHGs under title V, 

because the 100 tpy threshold would continue to apply as a 

matter of state law. Commenters stated that states would need 

to undertake a regulatory and/or legislative process to change 

the threshold in their state laws which they could not complete 

before the laws would otherwise require issuance of operating 

permits to GHGs sources. After considering the commenters’ 

concerns, we are finalizing an approach designed to address the 

state law concerns for states. As a result, it is unnecessary 

to move forward at this time with our proposed approach to limit 

approval of existing part 70 programs in many states. 

 EPA’s approach involves the interrelationship of terms 

within the part 70 definition of “major source” in title V and 

EPA’s implementing regulations, and EPA’s historical practice of 

interpreting the term “any air pollutant” in the “major 

stationary source” component of that definition. EPA believes 

the approach in the final rule will allow many states to adopt 

the final rule through interpretation of existing state laws. 

Specifically, paragraph (3) within the definition of “major 

source” found in 40 CFR 70.2 and 71.2 defines a major source as 

a “a major stationary source of air pollutants, as defined in 

section 302 of the Act, that directly emits or has the potential 

to emit, 100 tpy or more of any air pollutant...” The EPA 
362

previously articulated the Agency’s interpretation that the 

regulatory and statutory definitions of “major source” under 

title V, including the term “any air pollutant,” applies to 

pollutants “subject to regulation.” Memorandum from Lydia N. 

Wegman, Deputy Director, Office of Air Quality Planning and 

Standards, U.S. EPA, to Air Division Directors, “Definition of 

Regulated Air Pollutant for Purposes of Title V” (April 26, 

1993) (Wegman Memo). EPA recently re-affirmed this position in 

EPA’s Reconsideration of Interpretation of Regulations that 

Determine Pollutants Covered by Clean Air Act Permitting 

Programs. 75 FR 17704, 17022-23 (April 2, 2010) (Interpretive 

Memorandum Reconsideration Final Action). 

 Accordingly, under our long-established policy, states 

historically have interpreted the term “any air pollutant” under 

the title V definition of “major source” to mean any pollutant 

“subject to regulation” under the Act. Thus, as a matter of 

established interpretation, EPA and states effectively read the 

definition of “major source” under title V to include a source 

“...that directly emits or has the potential to emit, 100 tpy or 

more of any air pollutant subject to regulation under the Act” 

[emphasis added]. By amending our regulations to expressly 

include and define “subject to regulation” to implement our 

tailoring for GHGs under title V, we are seeking to enable 
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states to adopt and implement this approach through a continued 

interpretation of the phrase “any air pollutant” within the 

“major source” definition, without the need for changes to state 

regulations or statutes. States may be able to track EPA’s 

approach to tailoring for GHG permitting without regulatory or 

statutory changes, for example, where a state has taken the 

position, or determines now, that the state’s interpretation of 

“major source,” “subject to regulation” and/or “any air 

pollutant” is intended to track EPA’s interpretation. 

 Thus, EPA is adding the phrase “subject to regulation” to 

the definition of “major source” under 40 CFR 70.2 and 71.2. 

EPA is also adding to these regulations a definition of “subject 

to regulation.” Under the part 70 and part 71 regulatory 

changes adopted, the term “subject to regulation,” for purposes 

of the definition of “major source,” has two components. The 

first component codifies the general approach EPA recently 

articulated in the “Reconsideration of Interpretation of 

Regulations That Determine Pollutants Covered by Clean Air Act 

Permitting.” 75 FR 17704. Under this first component, a 

pollutant “subject to regulation” is defined to mean a pollutant 

subject to either a provision in the CAA or regulation adopted 

by EPA under the CAA that requires actual control of emissions 

of that pollutant and that has taken effect under the CAA. See 
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id. at 17022-23; Wegman Memo at 4-5. To address tailoring for 

GHGs, EPA includes a second component of the definition of 

“subject to regulation,” specifying that GHGs are not subject to 

regulation for purposes of defining a major source, unless as of 

July 1, 2011, the emissions of GHGs are from a source emitting 

or having the potential to emit 100,000 tpy of GHGs on a CO2e 

basis. 

 As explained previously, we find no substantive difference 

between the alternative mechanisms for implementing GHG 

tailoring in the final rule. Whether we add GHG thresholds 

directly to the definition of “major source” (as we proposed), 

or alternatively, expressly add and define the term “subject to 

regulation,” both approaches revise the definition of “major 

source” to implement the GHG Tailoring Rule. Accordingly, we 

adopt the later approach to facilitate state implementation of 

the final rule through an interpretation of existing state part 

70 programs. Similar to our explanation previously for PSD, 

while we adopt the “subject to regulation” mechanism for 

implementing GHG tailoring in the final rule, the thrust of our 

rulemaking is to apply the title V definition of “major source” 

– which includes the statutory term, “major stationary source” - 

to GHG sources by treating only GHG sources that emit at levels 

above the steps 1 and 2 thresholds as meeting that definition. 
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Further, we believe that our action may reasonably be construed 

to revise any of several terms in that definition, including (i) 

the numerical thresholds, as we proposed; (ii) the term “any air 

pollutant,” (iii) the term “a major stationary source,” (iv) the 

term “subject to regulation,” which, as discussed previously, 

our regulations graft into the definition of “major source.” We 

believe that the specific choice of which term constitutes the 

legal mechanism does not have a substantive legal effect because 

each mechanism involves one of the components of the regulatory 

term “major source” – which embodies the meaning of the 

statutory term, “major source” -- and it is that term that we 

are interpreting to tailor title V applicability for GHGemitting sources. Thus, while the “subject to regulation” 

mechanism facilitates expeditious implementation by states, and 

we are therefore revising our regulations to adopt this 

approach, we otherwise find no substantive difference between 

the alternative mechanisms we may use to finalize the proposed 

rule. 

Further, similar to our revised approach for addressing 

state SIP-approved PSD programs, we are delaying our action to 

limit our previous approvals for state part 70 operating permit 

programs. In our proposed rule, we explained our concern that 

states lack adequate personnel and resources to carry out part 
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70 operating permit programs for GHG sources that emit or have 

the potential to emit 100 tpy of GHGs. Accordingly, we proposed 

to use our general rulemaking authority under section 301(a) of 

the CAA and APA section 553 to limit our prior approval of state 

operating permit programs. This limited approval action would 

have had the effect of applying CAA permitting requirements only 

to sources that exceed the permitting thresholds established in 

this rule for the phase-in, because only those sources would be 

covered by the federally approved part 70 programs. 74 FR at 

55345. As discussed previously, we are proceeding with a 

slightly revised approach to address concerns similar to those 

raised with our proposed approach for addressing SIP-approved 

PSD permit programs. Because we now recognize that, like the 

PSD program, many states will be able to implement the final 

rules without the need to revise their existing part 70 

operating permit programs, we are delaying further action on our 

proposal to limit approval of existing part 70 programs until we 

better understand how permitting authorities will implement our 

final rule. 

In addition to the information requested previously on SIPapproved PSD permit programs, we ask each state to submit a 

letter to the appropriate Regional Administrator no later than 

[INSERT DATE 60 DAYS AFTER PROMULGATION] detailing the state’s 
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plan for permitting of GHG sources under the state’s part 70 

program. In that letter, states should explain whether they 

will adopt an interpretation of the terms “major source” or any 

of its component terms – “a major stationary source,” “any air 

pollutant,” or “subject to regulation,” or the numeral 

thresholds -- that is consistent with EPA’s regulatory 

interpretation of the these terms as codified at 40 CFR 70.2, 

and whether the state intends to adopt the interpretation 

without undertaking a regulatory or legislative process. This 

approach may be available, for example, where a state has taken 

the position, or determines now, that the state’s interpretation 

of these terms is intended to track EPA’s interpretation, 

resulting in title V permitting for sources of GHGs as described 

in EPA’s regulations adopted in this rule. If a state must 

revise its title V regulations or statutes to implement the 

interpretation, we ask that it provides an estimate of the time 

to adopt final rules or statutes in its letter to the Regional 

Administrator. If a state chooses not to (or cannot) adopt our 

interpretation, the letter should address whether the state has 

alternative authority to implement the GHG tailoring approach or 

some other approach that is at least as stringent, but which 

also addresses the expected shortfalls in personnel and funding 

and delays in permitting that would exist if the state carried 
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out permitting under part 70 program thresholds lower than those 

adopted by EPA in this final rule. For any state that is unable 

or unwilling to adopt the permitting thresholds in the final 

rules, and otherwise is unable to demonstrate adequate personnel 

and funding, EPA will move forward with finalizing a narrowed 

limited approval of the state’s existing part 70 program. If we 

do so, then we will respond in that action to comments on our 

proposal. 

In our proposed rule, we also noted that a handful of part 

70 operating permit programs may include provisions that would 

not require operating permits for any source of GHG emissions 

because, for example, the programs may apply only to pollutants 

specifically identified in the program provisions, and the 

provisions do not specifically identify GHGs. In these cases, 

states may be unable to interpret their regulatory provisions to 

interpret the term “any pollutant” to include pollutants 

“subject to regulation.” We indicated that we intended to take 

separate action to identify these programs, and to take 

regulatory action to correct this deficiency. Accordingly, we 

ask any state or local permitting agency that does not believe 

its existing part 70 regulations convey authority to issue title 

V permits to GHG sources consistent with the final rule to 

notify the Regional Administrator by letter as to whether the 
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state intends to undertake rulemaking to revise its rules 

consistent with these applicability thresholds. This 

notification should be done no later than the previously 

described letter regarding adoption of the Tailoring Rule, and 

could be combined with similar notifications we request 

regarding the PSD program. We intend to undertake a separate 

regulatory action to address part 70 programs that lack the 

ability to issue operating permits for GHG sources consistent 

with the final rule. We intend use our federal title V 

authority to ensure that GHG sources will be permitted 

consistent with the final rule. 

D. Rationale for Treatment of GHGs for Title V Permit Fees

The title V program requires permitting authorities to 

collect fees “sufficient to cover all reasonable (direct and 

indirect) costs required to develop and administer [title V] 

programs.” 45 To meet this requirement, permitting authorities 

either collect an amount not less than a minimum amount 

specified in our rules (known as the “presumptive minimum”), or 

may collect a different amount (usually less than the 

presumptive minimum). We did not propose to change the title V 

fee regulations in our notice of proposed rulemaking for this 

action, nor did we propose to require new fee demonstrations 

 45 The fee provisions are set forth in CAA Section 502(b)(3) 

and in our regulations at 40 CFR 70.9 and 71.9 
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when title V programs begin to address GHGs. However, we did 

recommend that each state, local or tribal program review its 

resource needs for GHG and determine if the existing fee 

approaches will be adequate. If those approaches will not be 

adequate, we suggested that states should be proactive in 

raising fees to cover the direct and indirect costs of the 

program or develop other alternative approaches to meet the 

shortfall. We are retaining this proposed approach, and are not 

changing our fee regulations as part of this final action 

establishing steps 1 and 2 of the phase-in. However, we are 

offering some additional clarification of our fee approach 

during these steps in response to comments we received on this 

issue. Additional discussion of fees will be included as part 

of subsequent actions establishing step 3 and beyond. 

A few state commenters suggested that EPA should modify 

part 70 to adopt a presumptive minimum fee (or range for such 

fee) for GHGs, some of whom suggested that current fees may be 

insufficient to cover the costs of their program. It is 

important to clarify that altering the presumptive minimum would 

only affect those states that chose to charge the presumptive 

minimum fee to sources. Most states – including some of the 

commenters asking EPA to raise the presumptive minimum -- 

collect a lower amount that is not based on the presumptive 
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minimum, but rather, relies on another fee schedule that it 

developed and EPA approved as adequate to cover costs. 

Therefore, it is useful to first discuss our approach to 

programs that have fee schedules resulting in a different amount 

before discussing our approach to the presumptive minimum. 

Because of the added GHG title V permitting workload 

described elsewhere in this notice, any state that will not, 

under its current fee structure, collect fees adequate to fund 

the permitting of GHG sources must alter its fee structure in 

order to meet the requirement that fees be adequate to cover 

costs. Changes may not be required in every instance; 

circumstances will vary from state to state. For example a 

state may see increases in revenue from newly-covered sources 

(based on emissions of pollutants already subject to fees) that 

fully cover the state’s increased costs, or a state may be overcollecting fees now and could use the surplus to offset the 

increased costs. Nonetheless, in many cases, we think states 

will need to adjust their fee structures to cover the costs of 

GHG permitting in order to meet the requirements of the Act and 

our regulations. 

For this reason, although we are not calling for new fee 

demonstrations at this time, we plan to closely monitor state 

title V programs during the first two steps of the Tailoring 
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Rule to ensure that the added workload from incorporating GHGs 

into the permit program does not result in fee shortfalls that 

imperil operating permit program implementation and enforcement, 

whatever the basis of the states’ fee schedule. As described in 

the proposal, such fee oversight by EPA may involve fee audits 

under the authority of §70.9(b)(5) to ensure that adequate fees 

are collected in the aggregate to cover program costs, with 

emphasis on whether the additional GHG workload is being 

appropriately funded. Also, EPA retains the ability to initiate 

a program revision under §70.4(i)(3) or issue a notice of 

deficiency under the process described in §70.10(b) to address 

fee adequacy issues, which may be uncovered during a fee audit. 

By relying on existing oversight measures, we are ensuring that 

the fee requirements are met with a minimum of disruption to 

existing programs at a time when they will already be facing 

significant challenges related to GHG permitting. 

Turning to the minority of states that do use the 

presumptive minimum, we did not propose to change the 

presumptive minimum calculation method to account for GHG. 

Currently under the statute and our rules, the presumptive 

minimum is based on a subset of air pollutants (i.e., VOC, NAAQS 

pollutants except for CO, and pollutants regulated under the 

NSPS and MACT standards promulgated under sections 111 and 112 
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of the Act, respectively) that does not include GHGs. The 

amount is specified on a per-ton basis and changes with 

inflation (it is currently set at $43.75/ton), but does not 

apply to emissions over 4,000 tpy of a given pollutant from a 

given source. We noted several difficulties in applying the 

presumptive minimum to GHG, including the large amounts of GHG 

emissions relative to other pollutants and the need for better 

data to establish a GHG-specific amount. Noting that GHGs are 

not currently included in the Act’s list of pollutants to which 

the presumptive fee applies, we also invited comment on whether 

we should raise the fee for listed pollutants to cover the added 

cost of GHG permitting. 

A few state commenters asked us to set a presumptive fee 

for GHGs, which we take to mean we should add GHGs to the list 

of pollutants to which a presumptive fee would apply. However, 

many commenters noted that the current presumptive minimum fee 

is unreasonable for GHGs because GHGs are emitted in greater 

quantities than the pollutants currently subject to presumptive 

fees, which would result in excessive fees. These commenters 

believe that EPA needs to limit the fees that states can charge 

for GHGs. Moreover, one commenter read the statute to prohibit 

us from listing GHGs in the presumptive fee calculation in the 

first place. Several commenters disagreed with the idea of 
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instead increasing the presumptive fee for other pollutants to 

cover the cost of regulating GHGs, some of whom believed that 

this would unfairly punish existing sources or would bring in no 

new revenue from sources triggering title V for the first time. 

After considering these comments, we remain disinclined, as 

we were at proposal, to change the presumptive fee calculation 

regulations. While there is some support for changing the 

regulations, the comments confirm the challenges in doing so. 

While we expressly rejected charging the full presumptive cost 

per ton amount for GHG, we also did not propose language to 

establish a different amount just for GHG, to establish whether 

a different tpy cap would apply, or to assess whether GHGs could 

even be added to the list. Thus, many commenters were very 

concerned about whether the full $43.75 or the 4000 tpy cap 

would apply to GHG if we listed it as a regulated pollutant for 

fee purposes. Furthermore, we noted at proposal, and commenters 

did not disagree, that more data would be needed to establish 

the appropriate basis for the GHG presumptive minimum. We are 

not taking a final position in this notice on whether the 

statute is amenable to including GHG in the presumptive fee 

calculation currently, but these comments illustrate some of the 

difficulties of such an approach. 
375

At the same time, we are not increasing the presumptive 

minimum for other pollutants already included in the fee 

calculation. We disagree with the commenter who said such an 

approach would bring in no new revenue from newly-subject 

sources. Many of the newly subject sources would emit alreadyincluded pollutants. If new revenue from these pollutants were 

insufficient, and because the Act does not specify how the 

shortfall must be addressed, the amount of any projected 

shortfall could be made up by increasing fees on these 

pollutants. In fact, the projected shortfall could be addressed 

without having to inventory GHG emissions from title V sources, 

since the emissions of already-included pollutants are wellknown. We also note that, although some commenters are 

concerned that failing to assess fees for GHGs directly would be 

unfair, the statute does not provide that the presumptive fee be 

proportional to each type of pollutant or be proportionally 

allocated to all sources. Rather, the presumptive fee approach 

provides a backstop for states that do not wish to adopt a more 

tailored approach. Nonetheless, we have decided not to increase 

the presumptive fee amounts for other pollutants because we lack 

information about the extent to which shortfalls exist due to 

GHG permitting, and which mix of sources and fees is appropriate 

for addressing any such shortfall in a state. This decision 
376

also provides greater flexibility to states and minimizes 

disruption to existing programs. 

We note that, contrary to the statements of some 

commenters, the CAA provisions allowing for a presumptive fee 

calculation do not override the basic requirement that fees be 

adequate to cover costs. As noted previously, we expect states 

to see a revenue increase from emissions of listed pollutants at 

newly-major sources for GHG, and it is also possible that the 

presumptive minimum may currently be resulting in overcollection of fees in a state. Thus, a state continuing to use 

the presumptive minimum may not have a shortfall. However, if 

states using the presumptive minimum approach do have a revenue 

shortfall due to GHG permitting, the statute requires the 

shortfall to be addressed. The EPA has had, and will continue 

to have, the ability to require states that use the presumptive 

minimum to increase their fees if the presumptive minimum 

results in a revenue shortfall that imperils operating permit 

program implementation and enforcement. Thus, although we are 

not changing the presumptive minimum in our regulations, we plan 

to follow the same oversight approach for states using the 

presumptive minimum as for those collecting less based on a 

resource demonstration. As described previously, this approach 

may involve fee audits with emphasis on whether the additional 
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GHG workload is being appropriately funded, and other 

appropriate follow-up. 

Consistent with our proposal, EPA is not modifying its own 

part 71 fee structure (which closely mirrors the presumptive 

minimum) in order to charge an additional fee for GHG. EPA must 

revise its fee schedule if the schedule does not reflect the 

costs of program administration. We have not determined that 

the existing fee structure will be inadequate to fund the part 

71 programs costs during the first two phases of permitting GHGs 

as set forth in this action. However, we are required to review 

the fee schedule every 2 years, and make changes to the fee 

schedule as necessary to reflect permit program costs. 40 CFR 

71.9(n)(2). Thus we will continue to examine the increases in 

part 71 burden due to GHG permitting, the current revenue 

collection, and the increases in revenue from newly-subject part 

71 sources, and will adjust the part 71 fee approach 

accordingly. 

Finally, several state and industry commenters asked EPA to 

provide guidance and recommendations for an appropriate GHG fee 

structure. We note that title V grants permitting authorities 

considerable discretion in charging fees to sources for title V 

purposes and does not require or prohibit fees specifically for 

GHGs, provided the states collect fees in the aggregate that are 
378

sufficient to cover all the direct and indirect program costs. 

In responding to requests for guidance, we do not wish to limit 

state discretion. For example, some commenters suggest that EPA 

prohibit emissions-based fees for GHG or cap the amount that can 

be collected, while others suggest we provide a range of 

acceptable fees. We are concerned that, given the wide variety 

of fee approaches that states now take, providing specific 

guidance may be disruptive, rather than helpful, to states. 

On the other hand, we recognize that it will initially be 

difficult for states to establish an appropriate emissions fee 

for GHG. As noted previously, there are currently limited data 

available for establishing such a fee, and, due to the large 

quantities of GHG emissions, such a fee may only amount to a few 

cents per ton. At the same time, as noted in the proposal, a 

number similar to that used for other pollutants (e.g., the 

presumptive minimum of $45/ton of GHG) would be inappropriate 

because it would likely result in huge over-collection. Because 

of this challenge, we note that §70.9(b)(3) allows the state to 

charge fees to individual sources on any basis (e.g., emission 

fee, application fee, service-based fees, or others, in any 

combination). While most states use emissions-based fees, there 

is merit to considering all the available fee bases to address 

increased GHG workload, including approaches that do not require 
379

a GHG emissions inventory for fee purposes. For example, where 

it is possible to estimate a revenue shortfall as a percentage 

of fee revenue, it may be appropriate to simply attach a 

percentage-based surcharge to each source’s fee to match that 

shortfall. Similarly, where the shortfall could be estimated as 

a total dollar amount, a flat surcharge could be added to each 

source’s fee to address the shortfall. 

These suggestions should not be read to indicate that EPA 

prefers any particular approach, or that EPA rejects a cost per 

ton approach. Rather, they illustrate that it is possible to 

address a revenue shortfall without establishing a GHG per-ton 

fee. While the EPA is declining to recommend specific 

approaches in this preamble, we are committed to assisting 

states in implementing the fee requirements for GHG. Therefore, 

we will work with any state that requests assistance from EPA in 

developing a workable fee approach. 

E. Other Actions and Issues 

1. Permit Streamlining Techniques 

In our proposal, we stated that while we were phasing-in 

permitting requirements, we would make a concerted effort to 

assess and implement streamlining options, tools, and guidance 

to reduce the costs to sources and permitting authorities of GHG 

permitting. We recognized that the development and 
380

implementation of these techniques should be an integral part of 

our strategy during the phase-in period, and we stated that we 

would undertake as many of these streamlining actions as 

possible as quickly as possible. We discussed several 

streamlining techniques in particular, including (1) defining 

potential to emit (“PTE”) for various source categories, (2) 

establishing emission limits for various source categories that 

constitute presumptive BACT, (3) establishing procedures for use 

of general permits and permits-by-rule, (4) establishing 

procedures for electronic permitting, and (5) establishing 

“lean” techniques for permit process improvements. The first 

three of these approaches have the potential to have the 

greatest impact in reducing the numbers of sources subject to 

PSD or title V (the definition of PTE) or of reducing permitting 

costs (presumptive BACT and general permits or permits-by-rule). 

In our proposal, we also described the timing for 

development and implementation of these streamlining techniques. 

We explained that each of the first three techniques would 

generally take 3-4 years to develop and implement, and therefore 

would be of limited use in the near-term. This time frame is 

necessary because EPA will first need to collect and analyze 

small source data that we do not currently have – because these 

are sources that EPA has not traditionally regulated -- in 
381

order to assess which of these techniques are viable or 

effective for such sources. In general, EPA will then need to 

conduct notice-and-comment rulemaking to establish the 

approaches, and that rulemaking will need to address various 

legal and policy aspects of these approaches. After that, the 

permitting authorities will need some time to adopt the 

streamlining techniques as part of their permitting programs. 

We received several comments on streamlining techniques. 

In general, the comments indicate widespread support for our 

pursuit of streamlining approaches, but some commenters were 

concerned that one or more of EPA’s identified streamlining 

options were complex, vague, ineffective, and questionable 

legally. Noting our proposal to phase-in permitting, in part to 

allow more time to develop streamlining options for smaller 

sources, some commenters suggested that we should delay 

permitting for larger sources for the same reasons. We 

disagree. Such a delay is not justified under our legal basis 

for this rule. While implementation of steps 1 and 2 – which 

will cover larger sources -- will pose implementation 

challenges, and some of the streamlining tools could assist with 

meeting these challenges, we have assessed the burdens 

associated with GHG permitting and have established a phase-in 

schedule that represents a manageable workload, even in the 
382

absence of streamlining techniques. On the other hand, we do 

agree with these commenters that, absent streamlining, applying 

PSD and title V requirements to the much larger number of small 

sources would lead to absurd results and administrative 

impossibility. The sources for whom the phase-in delays 

applicability are precisely the sources that have the greatest 

need for streamlining measures, and thus the greatest need for a 

deferral while we develop and implement streamlining options. 

In addition, commenters generally echoed many of our 

concerns about why it will take time to put these measures in 

place, and no commenter presented any information to suggest 

that our 3-4 year estimate for the PTE, presumptive BACT, and 

general permit measures was invalid. 

For these three techniques, we continue to believe that as 

we noted at proposal, we will require collection of significant 

category-specific data for source and emission unit types that 

have heretofore generally not been regulated by the CAA (e.g., 

furnaces, water heaters, etc.), which could take up to 1 year. 

Moreover, commenters had differences of opinion as to whether 

and how we should move forward on these approaches, and some 

raised policy and legal issues that we would likely want to 

explore through a notice and comment process in order to assess 
383

which of these measures are viable to pursue further.46 Even if 

a rulemaking were done expeditiously, it would likely require 1 

year. Finally, unlike lean and electronic permitting, these 

approaches, once finalized by EPA, will likely require 

additional time of up to 2 years for states to adopt. Thus, it 

is clear that these approaches will not be in place in time to 

ease any burden prior to the planned rulemaking for step 3. 

Some commenters did observe that the fourth and fifth 

techniques, lean and electronic permitting, could, at least 

theoretically, become available sooner. However, these 

commenters also noted that successful design and implementation 

of these approaches will require implementation experience with 

GHG permitting that is not now available. We expect that for 

the lean and electronic permitting techniques, at least 1 year 

of implementation experience (of the type that we will gain 

starting in 2011) would be required, plus at least an additional 

year to extrapolate that experience to small sources and put 

these approaches into effect for small source permitting. Thus, 

 46 We do not attempt to address or resolve the various 

opinions about what legal or policy direction we must take 

regarding any of these streamlining options. The proper forum 

for doing that will be in the action(s) where we apply a given 

option. Nonetheless, our response to comments document provides 

additional detail about the options we described and what 

commenters said about our proposed options. In addition, the 

comments themselves can be accessed in the docket for this 

action. 
384

we do not think the lean and electronic permitting would be in 

place before the beginning of 2013. Moreover, a handful of 

commenters questioned whether lean and/or electronic permitting 

would alleviate significant burden. Thus we are not able, at 

this time, to presume that these approaches will ease any burden 

prior to the planned rulemaking for step 3. 

 It is also important to note that, as a practical matter, 

while these efforts to streamline the program for small sources 

are underway, EPA and states will also be devoting a significant 

amount of their permitting resources and expertise to 

implementing the PSD and title V programs for the GHG-emitting 

sources covered under Steps 1 and 2. We have established these 

steps in a manner that they will be feasible for EPA and 

state/local/tribal authorities, but even so, they will not only 

consume current permitting authority resources, but they will 

also require substantial additional resources. As a result, the 

efforts to develop and implement streamlining techniques will 

have to compete with the work necessary to administer existing 

programs. For example, during the remainder of 2010, as 

described elsewhere in this notice, EPA permitting program 

resources will, in addition to continuing to administer programs 

for non-GHG pollutants, be used to conduct at least the 

following GHG-related activities in addition to streamlining: 
385

(1) develop BACT and other information and guidance for 

implementing programs for sources covered by Step 1, followed by 

additional guidance and information for sources covered by Step 

2; (2) review and act on information we receive regarding state 

adoption of GHG permitting requirements, which may entail 

narrowing of previous SIP approvals or processing of other 

programmatic revisions; and (3) propose and finalize measures to 

address programs with deficiencies in GHG coverage. As the 

beginning of step 2 nears, we will also begin to receive and 

process the first applications for permits that will incorporate 

GHG requirements (i.e., those that will be issued after January 

2, 2011). States seeking to implement streamlining approaches 

will face similar competition for permitting resources. 

 These time frames and resource considerations for 

streamlining confirm the approach to phase-in that we are taking 

in this rule. First and foremost, they make clear that it will 

not be possible to have streamlining measures in place in time 

for either Step 1 or Step 2. Therefore our selection of 

threshold for those steps is not built on assumptions that 

streamlining will remove some or all of the burden during those 

steps. 

 Second, they make clear that, while no significant 

streamlining can be in place by the time we must begin to 
386

develop the step 3 rule (i.e., latter half of 2011, to 

promulgate by July 2012, effective July 2013), it is likely that 

by that time EPA and states will have had an opportunity to gain 

implementation experience that could serve as the basis for 

beginning to implement streamlining techniques that do not 

require rulemaking or state adoption (e.g., lean and electronic 

permitting). It is also likely that we will have had an 

opportunity to gather technical information – which we have 

already begun to gather --for certain source and emissions unit 

categories that would be necessary to support proposal of PTE or 

presumptive BACT approaches for those categories. We expect 

that the step 3 rulemaking will provide an opportunity for us to 

use that experience and data to begin to propose streamlining 

approaches that need notice and comment rulemaking. We can also 

begin to take into account any burden reductions from possible 

early streamlining efforts – that is, through lean and 

electronic permitting -- in the establishment of step 3. 

 Third, it is clear that the potential availability of 

streamlining measures does not call into question our decision 

that in no event will we broaden PSD and title V applicability 

to cover GHG-emitting sources below the 50,000 tpy CO2e level 

prior to July 2016, as discussed elsewhere. EPA cannot now 

predict the resources that will be required to implement PSD and 
387

title V programs for GHG-emitting sources once various 

streamlining techniques are ultimately completed. This is 

uncertain not only because we need data and implementation 

experience with GHG permitting during steps 1, 2, and 3 that we 

can apply to estimates for small sources, but also because, as 

comments indicate, there is a broad range of legal and policy 

issues to consider in crafting the streamlining approaches we 

ultimately adopt. We have presented an initial assessment of 

options and obtained views of commenters both supporting and 

opposing them, and it is the result of these future actions, 

whose outcomes are uncertain at this time, that will ultimately 

determine the extent to which streamlining approaches will allow 

for the administration of PSD and title V programs for numerous 

small sources. Thus, while we are optimistic that we can craft 

workable, common-sense solutions, we nonetheless, believe it is 

important to preserve our small source exclusion until we have 

not only had time to put the streamlining approaches in place, 

but also have had time to assess the burdens that remain, before 

we bring in additional sources below the 50,000 tpy levels. We 

believe that the 6-year timeframe will require a sustained 

intensive effort by EPA and states to develop, adopt, and 

implement streamlining techniques, and will require EPA to then 

evaluate those techniques and complete a rulemaking concerning 
388

PSD and title V applicability to small-sources based on that 

evaluation. In this manner, the 6-year period will give us the 

necessary time to make the best decisions about the actions we 

should take beyond step 3. 

While comments make clear that there are issues to be 

addressed, nothing in the comments has persuaded us that we 

should abandon our streamlining efforts. To the contrary, the 

strong support for these efforts shown by many commenters 

reinforces our intention, as stated at proposal, to move forward 

with these approaches as an integral part of our phase-in 

approach. Moreover, notwithstanding the competition for GHG 

permitting resources and expertise, we believe it is critical 

that we move forward expeditiously. As noted previously, we are 

already taking a first step by initiating permitting for larger 

sources, beginning January 2011, that will begin to provide 

valuable implementation experience. This experience can be 

useful in allowing states to begin implementing early 

streamlining measures, like lean and electronic permitting, 

which do not require EPA action. We have also already begun, 

and will continue, developing data necessary to support possible 

rulemakings addressing approaches such as PTE, presumptive BACT, 

and/or general permits. We expect to be able to use these data 

to support possible rulemakings on these topics, as appropriate, 
389

at about the same time as our step 3 rulemaking. There may also 

be available streamlining options that were not described in our 

proposal that warrant further consideration. Because of the 

uncertainty surrounding such approaches, we are not committing 

to finalize rules on any particular approach, but we do plan to 

explore all streamlining options as expeditiously as possible, 

beginning immediately and proceeding throughout the phase-in 

period, and we encourage permitting authorities to do the same. 

We commit to consider a wide array of possible streamlining 

measures, and we commit to propose and take comment on, in the 

step 3 rulemaking, a set of those measures that we determine are 

viable to pursue further. 

2. Guidance for Best Available Control Technology 

Determinations 

The CAA requires that a PSD permit contain, among other 

things, emissions limits based on the BACT for each pollutant 

subject to regulation under the Act emitted from the source that 

triggers PSD. 42 U.S.C. § 7475(a)(4); 42 U.S.C. § 7479(3). 

BACT is defined as follows: 

(3) The term "best available control technology" 

means an emission limitation based on the maximum 

degree of reduction of each pollutant subject to 

regulation under this Act emitted from or which 

results from any major emitting facility, which 

the permitting authority, on a case-by-case 

basis, taking into account energy, environmental, 

and economic impacts and other costs, determines 
390

is achievable for such facility through 

application of production processes and available 

methods, systems, and techniques, including fuel 

cleaning, clean fuels, or treatment or innovative 

fuel combustion techniques for control of each 

such pollutant. In no event shall application of 

"best available control technology" result in 

emissions of any pollutants which will exceed the 

emissions allowed by any applicable standard 

established pursuant to section 111 or 112 of 

this Act. Emissions from any source utilizing 

clean fuels, or any other means, to comply with 

this paragraph shall not be allowed to increase 

above levels that would have been required under 

this paragraph as it existed prior to enactment 

of the Clean Air Act Amendments of 1990. 

42 U.S.C. § 7479(3). 

Thus, the BACT process is designed to determine the most 

effective control strategies achievable in each instance, 

considering energy, environmental, and economic impacts. 

However, the case-by-case nature of BACT, together with the 

range of factors and technologies that must be considered, 

presents a challenge in determining BACT for newly regulated 

pollutants. When a new pollutant is regulated, the first permit 

applicants and permitting authorities that are faced with 

determining BACT for a new pollutant will likely need to invest 

more time and resources in gathering and analyzing information 

necessary to make an assessment of BACT under the statutory 

criteria. Once the PSD permitting program matures with respect 

to the new pollutant, successive BACT analyses will establish 

precedents that can inform subsequent BACT determinations. 
391

While the BACT provisions clearly contemplate that the 

permitting authority evaluate control strategies on a case-bycase basis, EPA recognizes the need to develop and share policy 

guidance and technical information for sources and permitting 

authorities as they begin to permit sources of newly regulated 

pollutants, such as GHGs. When applied in a practical manner, 

this additional EPA guidance and technical information should 

reduce time and resource needs when evaluating BACT for newly 

regulated pollutants. 

As described in the proposed GHG Tailoring Rule, EPA 

intends to compile and make available technical and background 

information on GHG emission factors, control technologies and 

measures, and measurement and monitoring methodologies for key 

GHG source categories. We expressed our intent to work closely 

with stakeholders in developing this supporting information and 

to ensure this information is available in sufficient time to 

assist permitting agencies in their BACT determinations. The 

proposal took comment on what other types of support or 

assistance EPA can provide to initially help air pollution 

control agencies with the permitting of GHGs. 

Commenters on the proposed GHG Tailoring Rule generally 

supported EPA providing technical information and policy 

guidance for sources of GHGs. Several commenters specifically 
392

requested guidance to clarify GHG-related issues, such as how to 

compute CO2e emissions, how to evaluate emissions of CO2 from 

biomass fuel, and whether an air quality analysis will be 

required for GHGs. Additionally, commenters requested that EPA 

issue “white papers” and other tools that would provide 

information on a range of control technologies and measures for 

major stationary source categories, such as power plants, cement 

kilns, glass furnaces, and other sources. Many of these 

commenters further requested that EPA provide an opportunity for 

stakeholder input on the guidance, and a few commenters insisted 

that permitting for sources of GHGs should not begin prior to 

issuing final guidance. 

Consistent with our commitment at proposal to involve all 

stakeholders in our guidance development, EPA called upon the 

CAAAC in September 2009, to provide assistance and 

recommendations for what types of guidance and technical 
393

information would be helpful.47 Specifically, our charge to the 

CAAAC was “... to discuss and identify the major issues and 

potential barriers to implementing the PSD Program under the CAA 

for greenhouse gases ... [and] focus initially on the BACT 

requirement, including information and guidance that would be 

useful for EPA to provide concerning the technical, economic, 

and environmental performance characteristics of potential BACT 

options.” This charge also requested the CAAAC to “identify and 

discuss approaches to enable state and local permitting 

authorities to apply the BACT criteria in a consistent, 

practical and efficient manner.” 

At its October 6, 2009 meeting, the CAAAC established a 

Climate Change Work Group, made up of 35 representatives from a 

variety of industries, state and local governments, and 

environmental and public health non-profit organizations, 

organized under CAAAC’s Permits, New Source Review and Toxics 

 47 The CAAAC is a senior-level policy committee established in 

1990 to advise the U.S. EPA on issues related to implementing 

the CAA Amendments of 1990. The committee is chartered under 

the Federal Advisory Committee Act and has been renewed every 2 

years since its creation. The membership is approximately 40 

members and experts representing state and local government, 

environmental and public interest groups, academic institutions, 

unions, trade associations, utilities, industry, and other 

experts. The CAAAC meets 3 times a year, normally in 

Washington, D.C. It provides advice and counsel to EPA on a 

variety of important air quality policy issues. The committee 

has formed several subcommittees to provide more detailed 

discussion and advice on many technical issues. 
394

Subcommittee. The Work Group initially focused its attention on 

the procedure for evaluating BACT and decided that the process 

and criteria for determining BACT for criteria pollutants 

represented a workable and acceptable framework for GHGs. The 

Work Group also recommended a second phase, in which the Work 

Group would consider member proposals regarding possible 

alternative or supplementary approaches to applying the PSD 

program to GHG sources. 

In February 2010, the CAAAC completed work on the first 

phase of its effort and sent EPA a list of recommendations that 

highlighted areas of the BACT determination process that are in 

need of technical and policy guidance. For more information, 

see the Interim Phase I Report on Issues related to BACT for 

GHGs, February 3, 2010 that is located in the public docket for 

this rulemaking and at 

http://www.epa.gov/air/caaac/climate/2010_02_InterimPhaseIReport

.pdf. In response we are working on a number of fronts to 

develop technical information, guidance, and training to assist 

states in permitting large stationary sources of GHGs, including 

identifying GHG control measures for different industries. EPA 

is currently working with states on technical information and 

data needs related to BACT determinations for GHGs. This 

includes developing the EPA Office of Research and Development 
395

GHG Mitigation Strategies Database, enhancing the RACT/BACT/LAER 

Clearinghouse to include GHG-specific fields, and preparing 

technical information on sector-based GHG control measures. 

Also, EPA is actively developing BACT policy guidance for GHGs 

that will undergo notice and comment and will culminate in 

training courses for state, local and tribal permitting 

authorities. The results of all of these efforts will roll out 

over the remainder of 2010. EPA currently awaits the Work 

Group’s recommendations from its second phase of deliberations, 

which is underway as of the date of this notice. 

EPA does not agree with some commenters’ suggestion that 

EPA should delay permitting any sources until final BACT 

guidance is issued. As discussed in the final action on 

reconsideration of the Interpretive Memo, delaying the 

application of BACT to enable the development of guidance or 

control strategies is not consistent with the BACT requirements. 

63 FR at 17008. Furthermore, as just described, EPA expects 

such a delay to be unnecessary because EPA will soon begin 

providing technical information to inform BACT decisions, and 

will continue to provide additional guidance prior to the date 

that GHG permitting begins. However, even in the absence of 

such guidance, a delay would not be justified under the legal 

doctrines of absurd results and administrative necessity. While 
396

implementation of the BACT requirement during steps 1 and 2 will 

pose implementation challenges, EPA has assessed the burden 

associated with GHG permitting with consideration given to these 

challenges, and has established a phase-in schedule that 

represents a manageable workload. 

Thus, while BACT will remain a case-by-case assessment, as 

it always has been under the PSD program, EPA is confident that 

this guidance development effort will help support a smooth 

transition to permitting emissions of GHGs. Furthermore, EPA 

will continue to work to provide the most updated information 

and support tools to allow permitting authorities to share and 

access the most updated information on GHG BACT determinations 

as they are made once permitting of GHGs begins. EPA remains 

committed to involving stakeholders in the upcoming efforts to 

develop guidance to help to permitting authorities in making 

BACT determinations for sources of GHGs. 

3. Requests for Higher Category-Specific Thresholds or 

Exemptions from Applicability 

Although we did not propose any categorical exemptions, 

many commenters requested exemptions from major source and major 

modification applicability determinations under title V and PSD 

for certain types of GHG-emitting sources or certain types of 

GHG emissions as follows: 
397

Source Categories. Many commenters requested various 

exemptions or exclusions from source applicability for GHGs 

under both PSD and title V permitting, either during the phasein period or permanently, citing anticipated burdens, societal 

costs, and differences in emission characteristics. Commenters 

representing non-traditional sources or source categories 

(sources that have not historically been required to get 

permits) requested exemptions from permitting based on GHG 

emissions, including agricultural sources, residential sources, 

and small businesses. In general, these commenters sometimes, 

but not always cited “absurd results” and “administrative 

necessity” arguments in their exemption requests. 

Several commenters from sectors that consume a great deal 

of energy in their industrial processes and that are subject to 

international competitiveness, such as aluminum, steel, cement, 

glass, pulp and paper, and other manufacturers, requested that 

they be exempt from permitting under this final rule. These 

commenters opine that we have not carefully considered the 

environmental and economic consequences of this action because 

if we had, we would have exempted them for several reasons, 

including (i) other countries typically exempt similar sources 

from GHG cap and trade programs because the industries are 

making significant energy efficiency improvements even in the 
398

absence of GHG regulation, and (iii) permitting such sources may 

cause many facilities to move to countries that have less 

regulation or no regulation for GHGs. 

Other industry groups cited unique characteristics of their 

emissions, or the quantities in which they are emitted, that 

they argued should justify exclusion or unique thresholds. 

Semiconductor production facilities asked for exemptions, 

arguing that combustion-related GHG emissions are different from 

their GHG emissions, which result from the use of high-GWP 

industrial gases, such as PFCs, with higher GWP values that are 

more likely to trigger permitting requirements at relatively low 

tpy values. One lime production commenter stated that EPA could 

encourage energy efficiency projects at their plants by 

excluding calcination and other process emissions, arguing that 

these emissions are a relatively small portion of the national 

inventory that will have no material effect on air quality and 

global warming. Another commenter requested that EPA exclude 

emissions from poultry production (natural bird respiration) 

from permitting consideration because the IPCC excludes them 

from their GHG emission estimates. Representatives of the 

landfill industry pointed to the relationship between current 

statutory thresholds that apply to their regulated emissions, 

primarily NMOC, and the equivalent amount of GHG emissions this 
399

corresponds to. They argued for a source-category specific 

threshold that is at least equivalent to their current NMOC 

threshold, or roughly 750,000 tpy CO2e according to their 

estimate. 

Although the proposal for the Tailoring Rule generally 

addressed how the statutory requirements for major source 

applicability (100/250 thresholds) could be phased-in in ways 

that would offer relief to traditional and non-traditional 

sources, such as residences, farms, small business, and 

semiconductor manufacturers, it did so by establishing 

relatively high CO2e thresholds during the early implementation 

period and lowering the thresholds over time as streamlining 

mechanisms become available to reduce administrative burdens. 

We did not propose any permanent exemptions of any kind. Also, 

note that the proposal discussed energy efficiency, process 

efficiency improvements, recovery and beneficial use of process 

gases, and certain raw material and product changes in the 

context of short-term, low-cost means of achieving GHG emission 

reductions for small-scale stationary sources, but not in the 

context of exemptions. 

As discussed previously, we are still considering whether 

permanent exemptions from the statute are justified for GHG 

permitting based on the “absurd results” legal doctrine. 
400

However, we do not have sufficient basis to take final action at 

this time that would promulgate any of the suggested exclusions 

on the grounds, described previously, suggested by the 

commenters. We did not propose any sort of permanent exclusion 

based on an interpretation of the statutory provisions of PSD or 

title V. Regardless of any arguments about the legality and 

advisability from a policy or economic standpoint of such 

exclusions, we would need to propose a PSD and/or title V 

specific legal and policy rationale that fits within the CAA, to 

specify details regarding our implementation approach, and to 

provide an opportunity for public comment before adopting any 

such exclusion. Therefore we are not doing so here. We note, 

however, that nothing in this rule forecloses the opportunities 

we may have to explore such options in the future. Therefore, 

we are taking no action in this rule on these various 

commenters’ requests for exclusions. 

The remaining option for creating such exclusions in this 

rule is to find that such an exclusion is necessary to avoid 

overwhelming permitting burdens. We did solicit comment on 

alternative approaches to burden relief in the proposed phase-in 

for permitting. Some commenters suggested that the 

administrative necessity or absurd results rationale could be 

used to create at least temporary exclusions that would allow 
401

more sources to escape permitting than what we proposed We 

considered each of these requests in the context of the 

overwhelming permitting burdens and the options for reducing 

such burdens, and ultimately decided that, given our thresholdbased approach to the phase-in, it is not appropriate to also 

adopt such exclusions to address the same burdens. We have 

finalized steps 1 and 2 using the threshold-based approach, 

which applies the various legal doctrines, in the context of the 

Chevron framework, in a way that effectively exempts all small 

sources during this part of the phase-in. The suggested 

exclusions alone would not address the overwhelming permitting 

burdens, and the threshold-based approach would still be 

necessary. Moreover, once the threshold approach is applied as 

described, we do not see that the remaining burdens would be so 

overwhelming as to provide a basis under our legal rationale for 

exclusion. While we could have crafted specific exemptions of 

the kind suggested as an alternative means of tailoring the 

programs, our approach achieves the same result and does so in a 

way that will be simpler to administer. In any event, 

commenters did not provide enough specific information about the 

costs and administrative burdens associated with permitting 

their source categories to persuade us to exclude those source 

categories, consistent with our overall rationale. Furthermore, 
402

specifically with respect to high GWP, gases as discussed 

previously, are maintaining the statutory mass-based threshold 

that addresses commenters’ concerns regarding the inclusion of 

those gases. Therefore, we are not finalizing any such 

exclusions in this rule and, as noted above, we are not taking 

final action in the commenters’ requests for exclusions. 

Concerning the comment that we did not take appropriate 

economic and environmental considerations into account for this 

rulemaking action, we disagree. The approach we finalize in 

this notice for steps 1 and 2 minimizes economic burdens by 

limiting permitting to the largest GHG emission sources. We 

further note that the PSD program as applied to the sources that 

are covered in steps 1 and 2 contains an express requirement to 

take energy, environmental, and economic considerations into 

account when making control technology (i.e., BACT) decisions 

and accordingly many of the concerns about control costs will be 

able to be accounted for in that analysis. 

Biomass Combustion/Biogenic Emissions. Several commenters 

request that EPA exempt emissions from biogenic activities or 

biomass combustion or oxidation activities, including solid 

waste landfills, waste-to-energy projects, fermentation 

processes, combustion of renewable fuels, ethanol manufacturing, 

biodiesel production, and other alternative energy production 
403

that uses biomass feedstocks (e.g., crops, or trees). For 

example, commenters urged that EPA exclude emissions from 

biomass combustion in determining the applicability of PSD to 

GHGs based on the notion that such combustion is “carbon 

neutral” (i.e., that combustion or oxidation of such materials 

would cause no net increase in GHG emissions on a lifecycle 

basis). Other commenters oppose the exemption of biogenic 

activities because they opine that carbon neutrality of biomass 

combustion is an incorrect assumption that stems from what they 

call a “critical accounting error” in the Kyoto protocols. 

These commenters oppose the exemption of biogenic/biomass 

activities, citing the lack of a valid scientific basis for 

treating these GHG emissions differently than other GHG 

emissions. 

The proposed Tailoring Rule did not address this issue of 

exemptions for biomass combustion or biogenic emissions. We are 

mindful of the role that biomass or biogenic fuels and 

feedstocks could play in reducing GHGs, and we do not dispute 

the commenters’ observations that state, federal, and 

international rules and policies recognize carbon-neutrality in 

various ways. However, we have determined that we do not have 

sufficient basis to create an exclusion from the permitting 

applicability provisions for biomass combustion or biogenic 
404

fuels and feedstocks. Such an exclusion alone, while reducing 

burdens for some sources, would not address the overwhelming 

permitting burdens described previously, and a threshold-based 

approach would still be needed. Once we adopt a threshold-based 

approach, we do not have information regarding the 

administrative burden of permitting projects that specifically 

involve these source types, nor did the commenters provide any 

that demonstrate an overwhelming permitting burden would still 

exist that justifies even a temporary exclusion for biomass 

sources. 

At the same time, we did not propose any sort of permanent 

exclusion based on an interpretation of the statutory provisions 

of PSD or title V. Regardless of any arguments about the 

legality and advisability of such an exclusion, we would need to 

propose a PSD and/or title V specific legal and policy rationale 

and specify details regarding our implementation approach (e.g. 

an approach to carbon accounting), and would need to provide an 

opportunity for public comment before adopting any such 

exclusion. Therefore we are not able to finalize such an 

approach here. We note, however, that we are not taking final 

action on commenters’ request for exclusion, and that nothing in 

this rule forecloses the opportunities we may have to explore 

such options in the future. 
405

We further note that, while we are not promulgating an 

applicability exclusion for biogenic emissions and biomass fuels 

or feedstocks, there is flexibility to apply the existing 

regulations and policies regarding BACT in ways that take into 

account their lifecycle effects on GHG concentrations. This 

topic has already been explored by the CAAAC workgroup on BACT 

issues related to GHGs that recently provided recommendations to 

EPA. These recommendations are located in the public docket for 

this rulemaking and at 

http://www.epa.gov/air/caaac/climate/2010_02_InterimPhaseIReport

.pdf. While that group was unable to come to a consensus on how 

biomass-based emissions should be treated, it provided us with 

information that we will consider as we issue guidance on BACT. 

As previously discussed, we plan to issue BACT guidance later 

this year, but are not doing so as part of this rulemaking. 

This issue warrants further exploration in that context, and we 

plan to fully explore it and take action as appropriate. 

Fugitive Emissions. Numerous commenters believe that 

fugitive GHG emissions should be excluded from major source 

determinations, citing difficulties in measuring or estimating 

such emissions. Others believe EPA did not address fugitive 

emissions in the proposal and they ask for clarification of the 

treatment of fugitive GHGs in applicability determinations under 
406

PSD and title V. Some of these commenters state that EPA has 

not undertaken a rulemaking under section 302(j) for any source 

category of fugitive GHGs, so they should not be included. 

Several commenters representing the solid waste disposal 

industry requested exemptions for fugitive emissions for 

landfills and waste-to-energy projects, pointing out that 

current practice under PSD is for fugitive emissions from 

certain landfills to not be counted toward major source 

determinations. 

In the proposal, EPA did not offer any specific guidance or 

discuss exemptions for fugitive emissions of GHGs. Commenters 

did not suggest that a fugitive exemption would address the 

overwhelming permitting burdens described previously, or that it 

was necessary to specifically tailor GHG applicability through 

the use of a fugitive emissions exclusion for categories that 

would otherwise be required to include them. We do agree with 

commenters who stated that we should clarify how to count 

fugitives in determining applicability under this rule. In 

response, we note that we are not taking final action with 

respect to commenters’ request, and we are not finalizing any 

special rules for fugitive emissions related to GHG. Thus, 

EPA's rules related to the treatment of fugitives would apply. 

Regarding the comment that a 302(j) rulemaking is required 
407

before fugitive emissions may be counted, we disagree. As we 

read 302(j), once EPA has established by rule that fugitive 

emissions are to be counted for a specific source category, 

nothing in section 302(j) requires EPA to conduct new rulemaking 

to allow for the counting of additional pollutants from that 

category. We read 302(j) as imposing an obligation to determine 

if fugitive emission generally should be counted from a source 

or source category and not requiring that EPA list both source 

categories and relevant pollutants. Indeed, our practice in 

listing categories has not been to limit the pollutants to which 

the listing applies. Therefore, we are applying our existing 

rules and policies for fugitive emissions for GHG as we would 

any other pollutant. 

Pollution Control Projects. Other commenters request 

exemptions for pollution control projects from PSD major 

modification requirements, particularly projects that increase 

the efficiency or thermal performance of a unit or facility, 

resulting in emission reductions on a pounds/megawatt-hour or 

production basis. The current PSD rules do not exclude 

pollution control projects from being considered a physical 

change or change in the method of operation that would – if it 

resulted in a significant net emissions increase -- constitute a 

major modification, nor does case law suggest that we could 
408

adopt a permanent exclusion in the future48. We also do not 

believe we should adopt an exclusion for pollution control 

projects that relies solely on absurd results or administrative 

necessity for reasons similar to those described previously for 

other requested exclusions. Although such an exclusion may have 

positive features, it would not address the overwhelming 

permitting burdens that justify the tailoring approach. 

4. Transitional Issues including Requests for Grandfathering 

In the Tailoring Rule proposal, we did not discuss or 

specifically ask for comment on any provisions to address the 

transition from a permitting regime that does not incorporate 

greenhouse gases to one that does, such as “grandfathering” 

provisions or similar approaches that would exempt previously 

issued permits or pending applications from having to 

incorporate requirements for greenhouse gases. We nonetheless 

received several public comments that addressed a variety of 

transitional issues. One group of comments addresses situations 

prior to permit issuance where a PSD or title V application is 

either administratively complete or more generally being 

 48 On June 24, 2005, the United States Court of Appeals for 

the District of Columbia Circuit vacated the portions of the 

2002 and 1992 NSR rules that pertained to PCP, among other 

provisions. In response to this Court action, on June 5, 2007, 

EPA removed these provisions from the NSR regulations. (See 72 

FR 32526). These provisions were added as part of EPA’s NSR 

improvement rule that was issued on December 31, 2002. 
409

processed prior to the trigger date for GHG permitting (“in 

process” applications). Another group of comments addresses 

situations where a PSD or title V permit is issued prior to the 

GHG trigger date and the commenters request that the application 

and/or permit be exempt from any requirements for updates 

related to GHGs after permit issuance. 

With respect to PSD, many commenters requested that we 

adopt a “grandfathering” approach to applicability to exempt 

projects that have administratively complete PSD or minor NSR 

permit applications pending when the GHG permitting requirements 

go into effect. Several commenters urged us to promulgate 

transition provisions (without specifically using the term 

“grandfathering”), pointing out that we have provided transition 

periods for revising pending PSD permits, in the past, when new 

PSD rules were issued (e.g., in late 1970s and 1980). These 

commenters assert that GHG requirements will cause more 

disruption than those previous rule changes. Several commenters 

asked that PSD applications be evaluated on the basis of the PSD 

requirements effective when the application is submitted and if 

submitted prior to the trigger date, then the application and 

permit would not need to address GHGs. Several commenters also 

asked that PSD sources with a valid permit that commences 

construction within 18 months of the trigger date not be 
410

required to seek a revised PSD permit for GHGs. Similarly, 

several commenters asked that PSD permits issued prior to the 

GHG trigger date not be required to be reopened only for the 

purpose of addressing GHG emissions. Additional commenters 

asked that we clarify that sources or projects not be required 

to obtain PSD permits if they obtained a determination that PSD 

did not apply (a “non-applicability” determination) prior to the 

GHG trigger date. Finally, many commenters also requested 

“grandfathering” for title V so that existing title V 

applications and permits do not need to be amended, revised, or 

resubmitted to address GHGs after they become “subject to 

regulation”. Other commenters asked that transition provisions 

for title V be provided in the final action that would be 

similar to those requested for PSD. 

 We partially addressed transitional issues for PSD 

permitting in our April 2, 2010 final action on reconsideration 

of the Interpretive Memo. 75 FR 17021. This action addressed 

the applicability of PSD permitting requirements for greenhouse 

gases to pending PSD permit applications that were (or will be) 

submitted prior to January 2, 2011 based on emissions of 

pollutants other than greenhouse gases. However, we have not 

yet addressed the questions raised by public comments concerning 

sources that obtain PSD permits, minor NSR permits, or 
411

determinations that no such permits are needed prior to the step 

1 period set forth in this rule. We have also not yet addressed 

questions about the applicability of PSD permitting requirements 

for sources that are not currently required to submit an 

application for a PSD permit but that could be required to do so 

in step 2 of the phase-in established in this action. In 

addition, our April 2, 2010 action did not address transitional 

issues concerning the application of the title V provisions to 

greenhouse gases. 

a. Transition for PSD Permit Applications Pending When Step 1 

Begins 

In our action on April 2, 2010, EPA explained that the 

Agency did not see grounds to establish a transition provision 

for pending PSD permit applications because we had determined 

that PSD permitting requirements would not apply the greenhouse 

gases for another 9 months. We explained that permit 

applications submitted prior to April 2, 2010 should in most 

cases be issued prior to January 2, 2011 and, thus, effectively 

have a transition period of 9 months to complete processing 

before PSD requirements become applicable to greenhouse gases. 

We also observed that, in the case of any PSD permit application 

review that cannot otherwise be completed within the next 9 

months based on the requirements for pollutants other than GHGs, 
412

it should be feasible for permitting authorities to begin 

incorporating GHG considerations into permit reviews in parallel 

with the completion of work on other pollutants without adding 

delay to permit processing. Additional discussion of EPA’s 

reasons for not developing transition provisions for PSD permit 

applications that are pending on January 2, 2011 are provided in 

the April 2, 2010 notice. 75 FR 17021-22. 

For these same reasons, we continue to feel that a 

transition period is not warranted to incorporate GHG 

requirements into any PSD permit applications that are pending 

when step 1 of the permitting phase-in begins for those sources 

that would otherwise need to obtain a PSD permit based on 

emissions of pollutants other than greenhouse gases. Thus, this 

action makes no change to the position we expressed on this 

particular issue in the April 2, 2010 notice. In this final 

rule on tailoring the PSD program to address GHGs, we have 

determined that the additional burden of incorporating GHG 

requirements into PSD permits for the sources already required 

to obtain such permits is manageable in the step 1 period. 

Thus, this rule has added no additional requirements or 

limitations that would justify deferring the establishment of 

pollution controls for this category of GHG sources once PSD 

permitting requirements are initially triggered for GHGs. 
413

b. PSD Permits Issued Prior to Step 1 

EPA has not historically required PSD permits to be updated 

or reopened after they are issued in the absence of an action by 

the applicant to change the physical or operational 

characteristics of the source described in the permit 

application. EPA’s PSD permitting regulations contain no 

provisions that address the modification or amendment of a PSD 

permit or require a PSD permit to be reopened or modified on the 

basis of new PSD permitting requirements that take effect after 

the final permit is issued. Since PSD permits are construction 

permits, EPA has not required updates to PSD permits in the same 

manner as is typically required for operating permits that 

incorporate a variety of applicable requirements (such as title 

V permits and NDPES permits under the Clean Water Act). In 

addition, unlike operating permits, PSD permits are not required 

to be renewed. However, if construction under a PSD permit is 

not commenced in a timely manner or is discontinued for an 

extended period, a PSD permit may expire if an extension is not 

requested or justified. See, 40 CFR 52.21(r)(2); 40 CFR 

124.5(g). 

With respect to the application of PSD permitting 

requirements for GHGs beginning on January 2, 2011, we do not 

see any cause to deviate from our historical practice of not 
414

requiring PSD permits to be reopened or amended to incorporate 

requirements that take effect after the permit is issued. Thus, 

we are not promulgating any new rules or requirements pertaining 

to PSD permits issued prior to Step 1 of the phase-in described 

in this rule. There is no mandatory requirement to reopen a 

previously issued PSD permit to incorporate GHG requirements 

that were not applicable at the time the permit was issued. 

A major source that obtains a PSD permit prior to January 

2, 2011 will not be required under EPA regulations to reopen or 

revise the PSD permit to address greenhouse gases in order for 

such a source to begin or continue construction authorized under 

the permit. Our current PSD permitting regulations provide that 

“[n]o new major stationary source or major modification to which 

the requirements of paragraphs (j) through (r)(5) of this 

section apply shall begin actual construction without a permit 

that states the major stationary source or major modification 

will meet those requirements.” 40 CFR 51.166(a)(7)(iii); 40 CFR 

52.21(a)(2)(iii). The term “begin actual construction” 

generally means “initiation of physical onsite construction 

activities on an emissions unit which are of a permanent nature” 

and includes activities such as “installation of building 

supports and foundations, laying underground pipework and 

construction of permanent storage structures.” 40 CFR 
415

51.166(b)(11); 40 CFR 52.21(b)(11). A source that begins actual 

construction authorized under a PSD permit prior to January 2, 

2011 will not be in violation of the prohibition described 

previously if it continues construction after that date. This 

portion of the regulation precludes only beginning construction 

without the appropriate preconstruction permit and does not 

require a permit to be updated to continue actual construction 

that has already begun. 

Furthermore, a source that is authorized to construct under 

a PSD permit but has not yet begun actual construction on 

January 2, 2011 may still begin actual construction after that 

date without having to amend the previously-issued PSD permit to 

incorporate GHG requirements. Sections 51.166(a)(7)(iii) and 

52.21(a)(2)(iii) require “a permit that states the major 

stationary source or major modification will meet those 

requirement,” which refers to the “requirements in paragraphs 

(j) through (r)(5)” referenced earlier in those provisions. EPA 

construes this language to describe a permit that meets the 

requirements of paragraph (j) through (r)(5) that are in effect 

at the time the permit is issued. Permitting and licensing 

decisions of regulatory agencies must generally reflect the law 

in effect at the time the agency makes a final determination on 

a pending application. See Ziffrin v. United States, 318 U.S. 
416

73, 78 (1943); State of Alabama v. EPA, 557 F.2d 1101, 1110 (5th

Cir. 1977); In re: Dominion Energy Brayton Point, LLC, 12 E.A.D. 

490, 614-616 (EAB 2006); In re Phelps Dodge Corp., 10 E.A.D. 

460, 478 n. 10 (EAB 2002). 

 Thus, a source may begin actual construction on or after 

January 2, 2011 under a PSD permit that authorized construction 

to begin prior to January 2, 2011 because such a permit states 

that the source will meet the requirements of paragraphs (j) 

through (r)(5) of these regulations (or state equivalents) that 

were in effect at the time the permit was issued. However, this 

would not be the case if the permit has expired because the 

applicant has discontinued construction or failed to commence 

construction by the necessary date. See, 40 CFR 52.21(r)(2). 

This approach is consistent with EPA’s practice when the 

preconstruction permitting requirements change by virtue of the 

designation of an area as a nonattainment area after a PSD 

permit is in issued. In transitional guidance issued by EPA in 

1991, EPA explained that “the area designation in effect on the 

date of permit issuance by the reviewing agency determines which 

regulations (part C or D) apply to that permit.” Memorandum 

from John S. Seitz, Director OAQPS, New Source Review (NSR) 

Program Transitional Guidance, page 6 (Mar. 11, 1991). This 

memorandum explained further that “where a source receives a PSD 
417

or other permit prior to the date the area is designated as 

nonattainment, the permit remains in effect” as long as the 

sources meets the conditions necessary to prevent the permit 

from expiring. Id. at 6. 

 This approach does not apply if the source engages in a 

major modification after January 2, 2011 that is not authorized 

by the previously issued permit. Once step 1 of the phase-in 

begins, if the PSD requirements for GHGs are applicable to a 

previously-permitted source that engages in a major modification 

not covered by the permit, such a source will need obtain a new 

PSD permit to authorize the modification and that permit may 

need to include GHG requirements depending on the level of 

increase in GHGs that results from the modification. 

c. Additional Sources for Which PSD Applies in Step 2 

In light of the terms of existing PSD regulations and the 

lead time provided in this action for sources that will first 

become subject to PSD permitting in Step 2, we do not believe 

there is presently a need to establish transition provisions for 

sources that will be required to obtain PSD permits for the 

first time in Step 2 of the phase-in. As described previously, 

under our current PSD permitting regulations, a new major 

stationary source or major modification may not begin actual 

construction without a PSD permit that meets the applicable 
418

preconstruction permitting requirements. 40 CFR 

51.166(a)(7)(iii); 40 CFR 52.21(a)(2)(iii). 

Since a permit must be obtained before a major source may 

begin actual construction, the major source preconstruction 

permitting requirements in sections 51.166 and 52.21 of the 

regulation do not generally apply to sources that begins actual 

construction at a time when it was not a major source required 

to obtain a PSD permit. One exception, however, is the unique 

circumstance when a source becomes a major source solely by 

virtue of the relaxation of an enforceable limitation on the 

source’s potential to emit. 40 CFR 51.166(r)(2); 40 CFR 

52.21(r)(4). But absent these circumstances, PSD 

preconstruction permitting requirements do not generally 

preclude a source from continuing actual construction that began 

before the source was a source required to obtain a PSD permit. 

Thus, a source that began actual construction under the 

authorization of any previously required minor source or state 

construction permit is not required to meet any PSD 

preconstruction permitting requirement that becomes applicable 

after actual construction begins unless the source engages in a 

major modification after PSD permitting requirements are 

applicable. Likewise, a PSD permit is not required after a 

source begins actual construction based on a valid determination 
419

(by the source or the permitting authority) that the source need 

not obtain either a major PSD permitting requirements or and 

minor NSR permit. Based on these provisions in existing 

regulations, EPA will not require any sources to which PSD 

permitting requirements begin to apply in step 2 to obtain a PSD 

permit to continue construction that actually begins before step 

2 begins. 

However, we will expect Phase 2 sources that begin actual 

construction in phase 2 (i.e., beginning July 1, 2011) to do so 

only after obtaining a PSD permit in accordance with sections 

52.21, 51.166, or any applicable state regulation that meets the 

requirements of section 51.166. We recognize the potential for 

the triggering of step 2 to result in a change in status where a 

project may legally have begun actual construction before step 2 

but did not do so and would then need a PSD permit. However we 

also note that we are providing over a year of lead time before 

PSD permitting requirements become applicable to step 2 sources. 

If projects would be adversely affected by this change in 

status, this lead time affords an opportunity for sources 

planning such projects to secure appropriate minor NSR permits 

(which generally take less than a year to issue), nonapplicability determinations, etc. in time to avoid such a 

change in status. If a new or modified source that would become 
420

newly subject to PSD in step 2 plans to begin actual 

construction before step 2, it has more than a year to obtain 

the applicable preconstruction approvals and begin actual 

construction. Likewise, a step 2 source that does not 

anticipate the ability to begin actual construction before step 

2 begins should have enough lead time to submit a PSD permit 

application and obtain the necessary permit without 

significantly delaying the project further. Therefore, we do 

not think it is necessary or appropriate to promulgate a 

transition provision that would exempt step 2 sources from PSD 

permitting requirements that will apply based on construction 

that begins after step 2 takes effect. 

This approach for Step 2 sources that have obtained a minor 

source construction permit or non-applicability determination 

differs from the approach described previously for source that 

obtained a PSD permit prior to Step 1. As described previously, 

a Step 1 source that is authorized to begin actual construction 

before January 2, 2011 under a previously-issued PSD permit may 

begin actual construction under that permit after January 2, 

2011 without modifying the PSD permit to address GHGs. However, 

a Step 2 source that was not required to obtain a PSD permit 

before Step 2 begins would need to obtain a PSD permit 

addressing GHGs if it has not yet begun actual construction 
421

prior to Step 2, even if the source had obtained any 

preconstruction approvals that were necessary to authorize 

construction prior to Step 2. This is because such a Step 2 

source that begins actual construction after Step 2 would likely 

be doing so without having any permit meeting the requirements 

of paragraphs (j) through (r)(5) of section 52.21, 51.166, or a 

state equivalent. A source that has obtained only a minor 

source permit prior to Step 2 but that begins actual 

construction after July 1, 2011 would violate the requirements 

of section 52.21(a)(2)(iii), 51.166(a)(7)(iii), or a state 

equivalent, unless the source took care to ensure that it was 

authorized to construct under a PSD permit or could demonstrate 

that the source’s minor source construction permit makes clear 

that requirement of paragraphs (j) through (r)(5) of sections 

52.21, 51.166, or a state equivalent would be met by the source 

even though such a permit was not nominally a PSD permit. This 

difference in approach for non-PSD sources is driven by the 

terms of sections 52.21(a)(2)(iii) and 51.166(a)(7)(iii). Since 

we have not provided any prior notice that we might be 

considering revisions to sections 52.21 and 51.166 to address 

this topic, we are unable to revise the regulations in this 

action to achieve the same result for non-PSD sources as for PSD 

sources. Furthermore, this difference in approach is not 
422

unreasonable since non-PSD sources will not trigger permitting 

for GHG until step 2 (only anyway PSD source trigger in step 1). 

Thus sources will have until July 1, 2010, an additional 6 

months of lead time, to prepare for the transition described 

here. 

EPA has previously promulgated exemptions that have 

authorized some sources that were not previously subject to the 

PSD regulations to commence construction on the basis of minor 

source permits after the date new PSD requirements have took 

effect in 1978 and 1980. See e.g., 40 CFR 52.21(i)(1)(iv)-(v). 

There is a notable distinction between these provisions, which 

use the term “commence construction,” and the terms of sections 

52.21(a)(2)(iii) and 51.166(a)(7)(iii), which use the term 

“begin actual construction.” Commerce construction is defined 

more broadly than begin actual construction to include obtaining 

all necessarily preconstruction approvals and either beginning 

actual on-site construction or entering into binding contracts 

to undertake a program of actual construction. 40 CFR 

52.21(b)(9); 40 CFR 51.166(b)(9). The term commence 

construction is also defined in the CAA. 42 USC 7479(2)(A). 

Among other purposes, the term “commence construction” is 

generally used in the Act and EPA regulations to distinguish 

construction activities that are exempt from new PSD permitting 
423

requirements from those that are not. See e.g., 42 USC 7475(a); 

40 CFR 52.21(i)(1)(i)-(v). In the absence an explicit exemption 

in the CAA or the PSD regulations that uses the term “commence 

construction,” we do not believe we can use the date a source 

“commences construction” under a minor source construction 

permit approval as a demarcation point for Step 2 sources that 

may continue ongoing construction activities without having to 

obtain a PSD permit based on emissions of GHGs. Since we did 

not provide prior notice of an intention to adopt transition 

provisions applicable to this situation, we are unable to adopt 

such an exemption in this action that applies the term commence 

construction in this context. Consequently, the approach 

described previously applies the term “begin actual 

construction” based on the language in sections 52.21(a)(2)(iii) 

and 51.166(a)(7)(iii). 

d. Transitional Issues for Title V Permitting 

Since the title V permitting regulations already include a 

robust set of provisions to address the incorporation of new 

applicable requirements and other transitional considerations, 

we do not see grounds to establish unique transition or 

grandfathering provisions for GHGs in this action. Furthermore, 

since the purpose of title V is to collect all regulatory 

requirements applicable to a source and ensure compliance, we do 
424

not believe special exemptions for GHG requirements are likely 

to be justified. The existing title V rules do not provide any 

exemptions that relieve the obligation to incorporate all 

applicable requirements into a title V permit. However, the 

title V regulations contain numerous provisions that allow a 

reasonable period of time for incorporating new applicable 

requirements or applying for a title V permit that was not 

previously required. Transitional issues for incorporation of 

GHG requirements into title V permitting generally involve 

questions in the following categories: (1) permit application 

requirements for sources not previously subject to title V that 

will become subject to title V requirements in step 2 of the 

phase-in; (2) the need for updates or amendments to title V 

permit applications that are pending when GHGs become subject to 

regulation in Step 1 of the phase-in; and (3) the incorporation 

of new applicable requirements for GHGs into existing permits 

for sources currently subject to title V. 

With respect to the first category, a title V source 

applying for the first time must submit its permit application 

within 12 months after the source “becomes subject to the 

[operating] permit program” or such earlier time that the 

permitting authority may require (see §70.5(a)(1)). Sources not 

otherwise subject to title V can become major sources subject to 
425

title V due to emissions of GHG no sooner than July 1, 2011. If 

a source becomes “subject to the [operating] permit program” on 

July 1, 2011, then its permit application under the title V 

operating permit program would typically have to be submitted no 

later than July 1, 2012. 

There are also existing regulations relevant for the second 

category of GHG transition issues, where sources currently 

subject to title V have title V permit applications pending with 

a permitting authority as of January 2, 2011. Where additional 

applicable requirements become applicable to a source after it 

submits its application, but prior to release of a draft permit, 

the source is obligated to supplement its permit application. 

See 40 CFR 70.5(b); 71.5(b). Furthermore, title V permits are 

generally required to contain provisions to assure compliance 

with all applicable requirements at the time of permit issuance. 

See CAA section 504(a); 40 CFR 70.6(a)(1); 71.6(a)(1). If a 

permitting authority determines that additional information is 

necessary to evaluate or take final action on an application 

(e.g., because of uncertainty over whether a draft permit 

assures compliance with all applicable requirements), it may, 

and should, request additional information from the source in 

writing and set a reasonable deadline for a response. See 40 

CFR 70.5(a)(2); 71.5(a)(2). 
426

Likewise, the existing title V regulations provide 

sufficient transition for the third category of issues, where a 

source has additional GHG-related applicable requirements (such 

as the terms of a PSD permit) that must be incorporated into its 

existing title V permit. Where a source is required to obtain a 

PSD permit, the source must apply for a title V permit or permit 

revision within 12 months of commencing operation or on or 

before such earlier date as the permitting authority may 

establish (or prior to commencing operation if an existing title 

V permit would prohibit the construction or change in 

operation). See 40 CFR 70.5(a)(1)(ii); 71.5(a)(1)(ii); see 

also §§70.7(d) and (e); 71.7(d) and (e) (permit modifications). 

In addition, where a source becomes subject to additional 

applicable requirements, the permitting authority is required to 

reopen the permit to add those applicable requirements if the 

permit term has three or more years remaining and the applicable 

requirements will be in effect prior to the date the permit is 

due to expire. See 40 CFR 70.7(f)(1)(i); 71.7(f)(1)(i). 

Finally, EPA notes that the existing title V regulations 

require sources to furnish permitting authorities, within a 

reasonable time, any information the permitting authority may 

request in writing to determine whether cause exists for 

modifying, revoking, and reissuing, or terminating the permit, 
427

and for other reasons, and further provide that permitting 

authorities shall reopen and revise permits if EPA or the 

permitting authority determine that the permit must be revised 

or revoked to assure compliance with applicable requirements. 

See §§70.6(a)(6)(v);71.6(a)(6)(v) and §§ 70.7(f)(1)(iv); 

71.7(f)(1)(iv). 

Thus, EPA believes that the existing title V regulations 

provide an adequate regulatory framework for managing the 

transition to incorporating GHG requirements in title V permits 

and additional specific exemptions or transition rules for title 

V are not currently warranted. 

VI. What are the economic impacts of the final rule? 

This section of the preamble examines the economic impacts 

of the final rule including the expected benefits and costs for 

affected sources and permitting authorities. The final rule 

uses a phased-in approach for requiring sources of GHG emissions 

to comply with title V operating permit and PSD statutory 

requirements, essentially lifting this burden for a period of at 

least 6 years for a large number of smaller sources of GHG. 

Thus, this rule provides regulatory relief rather than 

regulatory requirements for these smaller GHG sources. For 

larger sources of GHG that will be required to obtain title V 

permits and/or comply on PSD requirements, there are no direct 
428

economic burdens or costs as a result of this final rule, 

because these requirements are not imposed as a result of this 

rulemaking. Statutory requirements to obtain a title V 

operating permit or to adhere to PSD requirements are already 

mandated by the CAA and by existing rules, not by this rule. 

Similarly, this rule will impose costs to society in the form of 

foregone environmental benefits resulting from GHG emission 

reductions that, absent this rule, might otherwise have occurred 

at sources deferred from permitting during the phase-in period. 

The regulatory impact analysis (RIA) conducted for this 

final rule provides details of the benefits or regulatory relief 

that smaller GHG sources will experience in terms of costs 

avoided as a result of this final rule and the potential for 

social costs in terms of foregone environmental benefits during 

this 6-year period. Complete details of the RIA conducted for 

this final rule may be found in the document "Regulatory Impact 

Analysis for the Final Greenhouse Gas Tailoring Rule," in the 

docket for this rulemaking. 

This rulemaking provides permitting thresholds for sources 

of GHG that exceed levels contained in the CAA and these levels 

are phased in steps based upon application of the administrative 

necessity and absurd results doctrines as explained in section 

V.B. For step 1 that is effective from January 2, 2011 through 
429

June 30, 2011, only sources required to undergo title V or PSD 

permitting based upon non-GHG air pollutants are required to 

obtain an operating permit or PSD permit to include GHG 

emissions. Step 2, effective from July 1, 2011 until such time 

as EPA acts on a rule to amend it (which for reasons described 

previously, we assume is June 30, 2013 for the purposes of this 

analysis), requires larger sources emitting GHG above 100,000 

CO2e tpy to obtain a title V permit (if they do not already have 

one) and to comply with PSD requirements when they are newly 

constructed or modify in a way that increases emissions by more 

than a 75,000 CO2e tpy significance level. Thereafter, EPA makes 

an enforceable commitment to consider a possible step 3 to 

further lower thresholds below 100,000 CO2e tpy and/or 

permanently exclude some sources from the program(s), but only 

after a regulatory process is conducted addressing 

administrative necessity and absurd results considerations based 

upon the actual permitting experiences in the first two steps of 

the phase-in. In addition, EPA provides a deferral of 

permitting until we take required action in April 2016 for 

sources and modifications that emit below 50,000 CO2e tpy. The 

deferral will end when a required study is conducted of the 

permitting process for sources of GHG and EPA acts, based on the 

study, to promulgate a rule that describes the additional GHG 
430

permitting requirements beyond 2016. In the 6 years following 

promulgation of this rule, the EPA estimates that compared to 

baseline estimates that do not include the effects of this rule, 

over six million sources of GHG emissions in total will be 

allowed to continue to operate without a title V operating 

permit. During this period, tens of thousands of new sources or 

modifying sources each year will not be subject to PSD 

requirements for GHG. For this large number of smaller sources, 

this rule alleviates the regulatory burden associated with 

obtaining an operating or PSD permit or complying with NSR BACT 

requirements. Therefore, this final action may be considered 

beneficial to these small sources because it provides relief 

from regulation that would otherwise be required. 

This decision does potentially have environmental 

consequences in the form of higher emissions during the 6-year 

period of time (generally because emissions increases would have 

been lower if BACT were applied). These consequences are 

limited due to the fact that sources between 100/250 and 100,000 

CO2e tpy account for an estimated 11 percent of the six directly 

emitted GHG nationally from industrial, commercial, and 

residential source categories, while representing over 95 

percent of the total number of sources potentially requiring an 

operating or PSD permit for GHG under current permitting 
431

thresholds in the CAA. Moreover, requiring such a large number 

of small sources to obtain permits for the first time would 

overtax the permitting authorities' abilities to process new 

permits and would therefore interfere with any such benefits 

actually being achieved. Moreover, reductions from these small 

sources will still be occurring, notwithstanding the fact that 

permitting requirements would not apply to them. These smaller 

sources of GHG will be the focus of voluntary emission reduction 

programs and energy efficiency measures that lead to reductions 

in GHG. We will also reevaluate this decision after a 6-year 

period and complete a study of the implications for those 

sources and permitting authorities of permitting smaller GHG 

sources beyond 2016. 

In reaching the preceding decisions for this final rule, we 

carefully considered comments received on the Tailoring Rule 

proposal. We received several comments specifically on our 

description of the impacts of this rule. Most of these comments 

disagreed with our assertion that the rule is a “relief” rule. 

Others assert that we should have prepared a more comprehensive 

RIA than prepared for the rule proposal. Those commenting 

contend: (1) we understated the burdens of the rule while 

overstating its relief at proposal; (2) we erroneously omitted 

the impacts for “larger sources” of GHG from the proposal RIA 
432

and should have recognized the burden to “larger sources” due to 

other GHG actions; (3) the economic impacts the rule will have 

on industry and the United States economy society in general 

will be burdensome, especially given the current state of the 

economy; and (4) we need to propose a full RIA or a complete 

estimation of impacts to comply with CAA section 307(d) and the 

APA. 

 EPA has carefully considered the comments addressing the 

issue of whether the Tailoring Rule is a regulatory “relief 

rule”, and we are not persuaded that we erred in concluding that 

the effect of the Tailoring Rule is to provide regulatory relief 

to a large number of sources of GHG for a period of up to 6 

years. This final rule will provide relief from title V 

permitting to over 6 million sources of GHG in this country. 

Likewise tens of thousands of sources potentially subject to PSD 

permitting requirements annually for GHG will have regulation 

postponed for a period of up to 6 years under this rule, 

followed by an additional required rule addressing the period 

beyond 6 years. While larger sources of GHG may be required to 

obtain title V permits or modify existing permits and to comply 

with PSD requirements, these burdens result not from the 

Tailoring Rule but rather from the CAA requirement to apply PSD 

to each pollutant subject to regulation, which is triggered when 
433

the LDVR takes effect. To clearly illustrate this, consider 

what would occur if EPA did not complete the Tailoring Rule. 

Sources would not be relieved of the requirement to obtain 

permits addressing each pollutant subject to regulation when 

they construct or modify, nor would they be relieved of their 

obligation to obtain title V permits. Instead, these 

requirements would simply apply to a much larger population of 

sources and modifications, and would lead to the absurd results 

and severe impairment to program implementation that this rule 

is designed to address. 

In response to comments asserting that the RIA completed 

for proposal of this rulemaking: (1) understated the burdens of 

the rule and overstated the benefits, (2) did not fully 

recognize the rule will be burdensome, especially given the 

current state of the economy; and (3) does not consider a 

complete estimation of impacts to comply with the Administrative 

Procedure Act and CAA section 307(d) and needs to correct flawed 

or erroneous assumptions, EPA did make improvements and 

modifications to the RIA completed for this final rule. Based 

upon comments, EPA modified estimates of the number of sources 

affected at various threshold levels upward. EPA also improved 

the burden estimates associated with obtaining permits for 

sources and permitting authorities. After consideration of the 
434

burden imposed by the proposed rule with these improved 

estimates for affected sources, the EPA modified the steps of 

the phase-in period to include two initial steps, described in 

section V, that are higher, and therefore cover fewer sources 

and are less burdensome than the proposal threshold of 25,000 

CO2e tpy emissions. EPA also increased the threshold below which 

permitting would not apply for 6 years from 25,000 to 50,000 tpy 

CO2e. After the initial two step period, EPA has committed to 

consider lower thresholds but only down to 50,000 tpy CO2e, and 

only after a regulatory process that uses information gathered 

on actual permitting activity during the first two steps of the 

phase-in period. The RIA conducted for the final rule also 

incorporates improvements in our estimates of the number of 

sources affected at alternative thresholds and improved 

estimates of the costs of obtaining permits by sources and 

processing permits by permitting authorities. The EPA 

acknowledges that the regulatory relief associated with the 

control costs due to BACT requirements for PSD new and modifying 

sources is not included in the RIA for the final rule due to the 

lack of sufficient data about the nature of those requirements. 

However, it is the case that, as it relates to burden, those 

estimates would simply increase the amount of regulatory relief 

associated with this final rule. 
435

Finally, with regard to comments that the RIA should have 

been a more comprehensive analysis to include the larger sources 

of GHG that will be required to obtain permits when GHG are 

regulated, the EPA maintains as previously explained that there 

are no direct economic burdens or costs as a result of this rule 

for these sources. Requirements for larger GHG sources to 

obtain title V or PSD permits are already mandated by the Act 

and by existing rules and are not imposed as a result of the 

Tailoring Rule. Thus the economic impacts for larger sources of 

GHG do not occur because of this Tailoring Rule. To include 

these larger sources in the RIA would actually be an inaccurate 

assessment of how this rule affects sources and would ignore the 

fact that this rule is regulatory relief. 

A. What entities are affected by this final rule?

As previously stated, this final rule does not itself 

result in the application of permitting requirements to any 

industrial, commercial, or residential entities. Entities 

affected by this rule are those who experience regulatory relief 

due to the higher thresholds and deferred applicability set 

forth in this rule. This action increases the threshold to 

obtain a title V and PSD permitting from statutory CAA levels 

using a phased-in step process as previously discussed. As table 

VI-1 shows, this action lifts permitting requirements for over 
436

six million potential title V sources in total and tens of 

thousands of potential PSD new sources annually that would be 

otherwise required by the CAA to obtain permits. Under step 1, 

over six million title V sources in total and approximately 20 

thousand new PSD sources per year will not be required to obtain 

permits. Under step 2, requiring sources over a 100,000 tpy CO2e 

to obtain a permit, over six million title V sources in total 

and approximately 19.9 thousand new PSD sources per year will 

obtain regulatory relief. While the threshold approach differs 

for steps 1 and 2 of the phase-in plan, the estimated number of 

sources affected does not differ greatly as shown in Table VI-1. 

Sectors experiencing this regulatory relief include electricity, 

industrial, energy, waste treatment, agriculture, commercial and 

residential.
437

Table VI-1. Estimated Number of Affected Sources Experiencing 

Regulatory Relief1,2

Number of Sources Experiencing Regulatory 

Relief 

Non-GHG Based <100,000 tpy

Sector Title V New PSD Title V New PSD 

Electricity 285 93 285 33

Industrial 170,910 604 170,654 599

Energy 2,588 48 2,536 44

Waste Treatment 3,358 2 3,165 1

Agriculture 37,351 299 37,351 299

Commercial 1,355,921 12,041 1,355,870 12,039

Residential 4,535,500 6,915 4,535,500 6,915

Totals 6,105,913 20,002 6,105,361 19,930

% Emissions Covered3 13% 11% 

Notes: (1) Number of sources is determined on a potential to 

emit basis. Estimates for title V are the total number of 

sources expected to experience regulatory relief. PSD sources 

are annual estimates of newly constructed facilities and do not 

include modifications at existing facilities that may also be 

subject to PSD requirements. (2) See Appendices to ‘Regulatory 

Impact Analysis of the Final Greenhouse Gas Tailoring Rule’ for 

more details of how thresholds and sources affected are 

developed. (3) Percentage of emissions covered represent 

estimated actual emissions from sources expected to experience 

regulatory relief as a percentage of total stationary source GHG 

emissions. 

B. What are the estimated annual benefits to sources due to 

regulatory relief from the statutory requirements?

EPA estimated the annual benefits (avoided costs) to 

sources of GHG emissions and permitting authorities anticipated 

from this final rule. In addition, an accounting of the 

benefits from this action as measured by avoided permit 

processing costs for state, local, and tribal permitting 

authorities is provided. These benefits or avoided costs relate 

specifically to information collection costs or burden costs 
438

postponed for smaller sources of GHG emissions otherwise 

required to obtain an operating permit under title V or required 

to modify an existing permit to address GHG emissions. Avoided 

costs shown also include information collection requirements for 

additional PSD permits postponed for new or modifying smaller 

sources of GHG, as well as the avoided costs to state, local and 

tribal permitting authorities. These estimates do not consider 

avoided emission control costs associated with PSD requirements 

for potential BACT requirements. Estimates for BACT are 

unavailable at this time because of the difficulty predicting 

the results of the BACT process as it would be applied to new 

pollutants and classes of sources for which there is no previous 

BACT experience on which to rely. 

1. What are annual estimated benefits or avoided burden costs 

for title V permits? 

Table VI-2 shows that the estimated annual title V benefits 

to sources and to permitting authorities in terms of avoided 

information collection cost resulting from this final action to 

be approximately $70,524.3 million under step 1 of the phase-in, 

the non-GHG based requirements threshold. These avoided costs 

become $70,517.1 million annually under step 2 of the phase-in 

where permitting is required for sources at or above the 100,000 

tpy CO2e threshold. Under the non-GHG based phase-in step 1, 

approximately $49,457.3 million in regulatory relief will accrue 
439

to sources and approximately $21,067 million to permitting 

authorities annually in the form of avoided permit processing 

costs. With the <100,000 tpy CO2e threshold for phase-in step 2, 

these annual regulatory relief benefits are expected to be quite 

similar at $49,455.4 million for sources of GHG emissions and 

$21,061.7 million for permitting authorities. Industrial 

sources permitting costs are estimated to be $46.4 thousand per 

permit for a new permit and $1.7 thousand for a permit revision. 

The EPA estimates that over tens of thousands of industrial 

sources per year will avoid incurring these permitting costs 

under steps 1 and 2 of the phase-in period. The cost for a 

permit for new commercial and residential sources is estimated 

to be $23.2 thousand per permit with approximately 2 million of 

these permits avoided annually. 

State, local, and tribal permitting authorities will also 

benefit in terms of avoided permitting administrative costs of 

over $21 billion as a result of the decisions final in this 

action. For industrial sources, the cost for permitting 

authorities to process a new industrial title V 

permit is approximately $19.7 thousand per permit and $1.8 

thousand for a permit revision. Similar permitting authority 

avoided permit processing costs are approximately $9.8 thousand 

per permit for a new commercial or residential title V permit. 

All estimates are stated in 2007 dollars. 
440

Table VI-2. Annual Title V Regulatory Relief for Sources and Permitting A

Step One 

Non-GHG Based

Step 

<100,000 

Activity 

Cost per 

Permit 

(2007$) 

Number of 

Permits 

Avoided Costs 

(millions 

2007$) 

Number of 

Permits 

A

Sources New Industrial $46,350 71,829 $3,329.3 71,829 New Commercial/ Residential $23,175 1,985,948 $46,024.3 1,985,930 Permit revisions due to GHG $1,677 61,836 $103.7 60,921 Source Total 2,119,613 $49,457.3 2,118,508 Permitting Authority New Industrial $19,678 71,829 $1,413.5 71,829 New Commercial/ Residential $9,839 1,985,948 $19,539.7 1,985,930 Permit revisions due to GHG $1,840 61,836 $113.8 60,921 Permitting Authority Total 2,119,613 $21,067.0 2,118,508 Total Title V Regulatory Relief $70,524.3 

Notes: (1) Annual title V avoided costs estimates represent information co

for one third of the total number of title V sources obtaining regulatory rTable VI-1 potentially requiring permits or permit revisions for GHG. (2) More details on these estimated regulatory relief benefits are availablAppendices to the “Regulatory Impact Analysis for the Final Greenhouse Gas Rule”. 
441

2. What are annual benefits or avoided costs associated with 

NSR permitting regulatory relief? 

Table VI-3 summarizes the estimated annual information 

collection costs avoided by sources and permitting authorities 

for PSD permitting due to this Tailoring Rule. The benefits 

associated with avoided cost of compliance for BACT for these 

sources is not included in these estimates due to a lack of 

available data. The estimated avoided burden or reporting and 

recordkeeping cost that would occur absent this rule for new 

industrial sources to obtain permits is estimated to be $84.5 

thousand for a modifying PSD industrial source and $59.2 

thousand for a modifying commercial or multi-family residential 

source. New PSD sources will also be required to obtain a title 

V permit increasing these costs to $130.9 thousand per permit 

for new industrial sources and to $82.3 thousand per permit for 

new commercial or multi-family residential sources. (Note the 

title V costs for these new PSD sources have been included in 

title V estimates shown in Table VI-2.) New and modifying 

sources avoid approximately $5.5 billion annually in PSD 

permitting costs with this rule under the phase-in step 1, nonGHG based threshold. Under the phase-in step 2, <100,000 CO2e 

tpy threshold and <75,000 tpy CO2e significance level, this 

avoided PSD permitting cost estimate becomes $5.4 billion 

annually. State, local, and tribal permitting authorities are 
442

expected to avoid about $1.51 billion annually in administrative 

expenditures associated with postponing PSD program requirements 

for these GHG sources under step 1 and $1.49 billion under step 

2. All estimates are shown in 2007 dollars. 
443

Table VI-3. Annual PSD Regulatory Relief for Sources and Permitting Author

Step One

Non-GHG Based

Step Tw

<100,000 

Threshold, <Significance 

Activity 

Cost 

per 

Permit 

(2007$)

Number 

of 

Permits 

Avoided 

Costs 

(millions 

2007$) 

Number 

of 

Permits 

A

(m

2

SourcesNew Industrial $84,530 26,089 $2,205.3 25174 $New Commercial/Residential $59,152 55,509 $3,283.5 55505 $Source Total 81,598 $5,488.8 80679 $Permitting Authority New Industrial $23,243 26,089 $606.4 25174 New Commercial/Residential $16,216 55,509 $900.1 55505 Permitting Authority Total 81,598 $1,506.5 80679 $Total Title V Regulatory Relief $6,995.3 $

Notes: (1) All estimates are based upon potential to emit. Regulatory reli

represents annual estimates of PSD permitting costs avoided under steps 1 aphase-in period. (2) More details on these estimated regulatory relief benavailable in the Appendices to the “Regulatory Impact Analysis for the FinaGas Tailoring Rule”. 
444

C. What are the economic impacts of this rulemaking?

This final rulemaking does not impose economic burdens or 

costs on any sources or permitting authorities, but should be 

viewed as regulatory relief for smaller GHG emission sources and 

for permitting authorities. Although sources above the 

thresholds set in this rule will become subject to permitting on 

January 2, 2011, those impacts are not attributable to the 

present rulemaking. Rather they are mandated by the CAA and 

existing regulations and automatically take effect independent 

of this action. 

In addition to considering the regulatory relief expected 

for affected entities as a result of this final rule, the EPA 

considered the impact of this rulemaking to small entities 

(small businesses, governments and non-profit organizations) as 

required by RFA and SBREFA. For informational purposes, the RIA 

includes the Small Business Administration (SBA) definition of 

small entities by industry categories for stationary sources of 

GHG and potential regulatory relief from title V and NSR 

permitting programs for small sources of GHG. Since this rule 

does not impose regulatory requirements but rather lessens the 

regulatory burden of the CAA requirements to smaller sources of 

GHG, no economic costs are imposed upon small sources of GHG as 

a result of this final rule. Rather this action provides 

regulatory relief for small sources. These avoided costs or 
445

benefits accrue because small sources of GHG are not required to 

obtain a title V permit and new or modifying small sources of 

GHG are not required to meet PSD requirements. Some of the 

small sources benefitting from this action are small entities, 

and these entities will benefit from the regulatory relief 

finalized by this rule. For discussion of comments received and 

EPA responses regarding small entities impacts, see section 

VIII. of this preamble. 

D. What are the costs of the final rule for society?

EPA examined the social costs of this final rule. These 

social costs represent the foregone environmental benefits that 

will occur as a result of the regulatory relief offered to 

sources of GHG emissions. This action is one of regulatory 

relief since it increases the emissions thresholds for the title 

V and PSD programs, as they apply to sources of GHG emissions, 

to levels above those in the CAA. In this preamble section, the 

benefits or avoided regulatory costs of such relief are 

discussed, but there is also a social cost imposed by such 

relief, because this rule may forego some of the possible 

benefits associated with title V and PSD programs for sources of 

GHG emissions below the permitting thresholds established. 

These benefits are those attributed to title V and PSD 

permitting programs in general. These benefits are based upon 

the relevance of these programs to policymaking, transparency 
446

issues, and market efficiency, and therefore are very difficult 

to quantify and monetize. For title V, they include the 

benefits of improved compliance with CAA requirements that stem 

from (1) improved clarity regarding applicability of 

requirements, (2) discovery and required correction of 

noncompliance prior to receiving a permit, (3) improving 

monitoring, recordkeeping, and reporting concerning compliance 

status, (4) self-certification of compliance with applicable 

requirements initially and annually, and prompt reporting of 

deviations from permit requirements, (5) enhanced opportunity 

for the public to understand and monitor sources’ compliance 

obligations, and (6) improved ability of EPA, permitting 

authorities, and the public to enforce CAA requirements. 

However, it is important to remember that a title V permit does 

not add new requirements for pollution control itself, but 

rather collects all of a facility’s applicable requirements 

under the CAA in one permit. Therefore, the compliance benefits 

above are less when title V permits contains few or no CAA 

applicable requirements. During the initial steps of the phasein plan established under this action, we expect that the vast 

majority of sources excluded from title V would be sources that 

have no CAA applicable requirements for GHG emissions and few or 

no requirements for other pollutants because their emissions of 

those pollutants are so small. For this reason while it is 
447

extremely difficult to measure the degree of improved 

compliance, if any, that would be foregone, or to quantify the 

social costs that would be imposed, we expect that they would be 

negligible. 

 For PSD, the primary social cost imposed by the Tailoring 

Rule stems from the foregone benefit of applying BACT to the 

tens of thousands of small new sources and modifications that 

will be below our final thresholds during the first steps of the 

phase-in. This social cost potentially weighs against the cost 

savings described previously that stem (in part) from avoiding 

the administrative and control costs of applying BACT to these 

sources. The BACT requirement assures that new and modified 

sources, when they increase their emissions are using state-ofthe-art emission controls and affords the public an opportunity 

to comment on the control decision. It does not prohibit 

increases but it assures that such controls are applied. 

Delaying the BACT requirement for numerous small sources during 

the first steps of the phase-in for this final rule could allow 

increases from these smaller sources that are greater than they 

would be if BACT were applied. A detailed analysis of this 

difference is beyond the scope of this rule, because we do not 

have detailed information on the universe of these tens of 

thousands of small PSD actions, the candidate BACT technologies 

for each of them, how permitting authorities would make the BACT 
448

decisions, and how the BACT limit would compare to what would 

otherwise be installed absent BACT. 

It is not possible at this time to quantify the social 

costs of avoided BACT. However we note that the universe of 

possible emissions that would be regulated by sources excluded 

under the Tailoring Rule is small compared to those that would 

remain subject to PSD. The sources excluded in these first two 

steps of the phase-in plan of this action comprise only 11 

percent of total stationary source GHG emissions, while 67 

percent remain subject to regulation. Furthermore, we expect 

the emissions differences due to BACT controls for such sources 

to be relatively small due to the lack of available capture and 

control technologies for GHG at such sources that are akin to 

those that exist for conventional pollutants and sources, as 

well as the likelihood that even in the absence of BACT such 

sources would already be installing relatively efficient GHG 

technologies to save on fuel costs. Thus, while potential 

benefits would be foregone by excluding smaller sources from the 

permitting programs, these benefits are likely to be small. 

Under the Tailoring Rule, we will be working during the 6-year 

period to greatly improve our understanding of both the 

administrative costs of regulating and the social costs of not 

regulating smaller sources under PSD and title V, and we will be 
449

relying on that information to support our future threshold 

analyses called for under the action. 

In reaching the decisions for this GHG Tailoring Rule, the 

EPA recognizes that GHG emissions can remain in the atmosphere 

for decades to centuries, meaning that their concentrations 

become well-mixed throughout the global atmosphere regardless of 

emission origin, and their effects on climate are long lasting 

and significant. A detailed explanation of climate change and 

its impact on health, society, and the environment is included 

in EPA's technical support document for the endangerment finding 

action (Docket ID No. EPA-HQ-OAR-2009-0171). The EPA recognizes 

the importance of reducing climate change emissions for all 

sources of GHG emissions including those sources afforded 

regulatory relief in this rule and plans to address potential 

emission reductions from these small sources using voluntary and 

energy efficiency approaches. Elsewhere, we have discussed 

EPA's interest in continuing to use regulatory and/or nonregulatory tools for reducing emissions from smaller GHG sources 

because we believe that these tools will likely result in more 

efficient and cost-effective regulation than would case-by-case 

permitting. 

VII. Comments on Statutory and Executive Orders Reviews 

In this section, we provide responses to comments we 

received for various Executive Orders (EOs). 
450

A. Comments on Executive Order 12866 - Regulatory Planning and 

Review

At proposal, EPA prepared an analysis of the potential 

costs and benefits associated with EPA’s Tailoring Rule proposal 

in an RIA. Several commenters state that EPA’s failure to 

estimate the full costs of the effects of its interpretation of 

PSD applicability in the proposed Tailoring Rule violates EO 

12866. Some of these commenters maintain that EO 12866 directs 

EPA to submit to the Office of Management and Budget (OMB) new 

significant regulations under consideration by the EPA. These 

commenters assert that, in the section 202 rule, EPA failed to 

analyze the effect on stationary sources in the cost benefit 

analysis and there is no indication that EPA included these 

impacts in its submission to OMB. According to the commenters, 

in EPA’s proposal for this rulemaking, EPA has similarly failed 

to analyze the costs and benefits of triggering PSD for 

stationary sources. The commenters assert that without this key 

information, OMB could not fully review the impacts of the 

proposed rule. The commenters believe that EPA’s failure to 

account for known costs that will occur as a direct result of 

the promulgation of the proposed rule in conjunction with the 

section 202 rule violates several applicable requirements of EO 

12866, including sections 6(B)(ii) and 6(C)(iii), which require 

assessments of the potential costs and benefits of the 
451

regulatory action and “reasonably feasible alternatives to the 

planned regulation, identified by the Agencies or the public . . 

.” thereby violating both the APA and CAA section 307(d) because 

they deprive businesses and permitting authorities alike of a 

meaningful opportunity to comment on the rule. 

 The EPA has prepared a revised RIA assessing the benefits 

and costs of the final Tailoring Rule to support this rulemaking 

in accordance with EO 12866 as was done with the proposal for 

this rulemaking. Similarly the RIA completed for this action is 

subject to review by an Inter-agency review panel that includes 

the President’s Office of Management and Budget as was the case 

with the proposal RIA. Further, the RIA completed for this 

final rule fully assesses the known benefits and costs 

associated with the Tailoring Rulemaking. This final rule is 

one of regulatory relief from statutory requirements in which a 

large number of sources of GHGs will be relieved of the burden 

of title V and PSD permitting for a period of at least 6 years. 

This final rule will provide relief from title V permitting to 

over 6 million sources of GHG in this country. Likewise tens of 

thousands of sources potentially subject to PSD permitting 

requirements for GHGs will have regulation postponed for a 

period of at least 6 years. While larger sources of GHG may 

still be required to obtain title V permits or modify existing 

permits and to comply with PSD requirements, these burdens 
452

result from existing statutory requirements, not from this final 

Tailoring Rule. 

B. Comments on Paperwork Reduction Act

At proposal, we stated in the preamble that we did not 

believe that the proposal would impose any new information 

collection burden. We concluded that the proposed action would 

reduce costs incurred by sources and permitting authorities 

relative to the costs that would be incurred if EPA did not 

revise the rule and provided estimates of those reduced costs. 

Further, we stated that, despite our estimated burden 

reductions, it was unnecessary for us to submit a new 

information collection request (ICR) to the OMB because the ICR 

contained in the existing regulations for PSD (see, e.g., 40 CFR 

52.21) and title V (see 40 CFR parts 70 and 71) had already been 

approved under the provisions of the Paperwork Reduction Act, 44 

U.S.C. 3501 et seq. and has assigned OMB control number 2060–

0003 and OMB control number 2060–0336, respectively. 

However, several commenters disagree that it was 

unnecessary for us to submit a new ICR for the proposed action. 

These commenters believe that (1) prior approval of an ICR for 

the PSD and title V programs ignores the fact that there would 

be an increase in the paperwork burden as a result of applying 

PSD and title V permitting requirements; and (2) unless EPA 

resubmits the information collection approval request to OMB 
453

with a proper and fully-inclusive analysis, EPA will lack 

authority to collect information from stationary sources for PSD 

and title V GHG emissions permitting. 

As we stated in the proposal, this is a burden relief rule 

and as such it does not impose any new requirements for the NSR 

or title V programs that are not currently required. For that 

reason, we concluded that for purposes of this rule it was 

unnecessary for us to submit a new ICR to the OMB and that the 

ICR contained in the existing regulations for PSD (see, e.g., 40 

CFR 52.21) and title V (see 40 CFR parts 70 and 71) that had 

already been approved under the provisions of the Paperwork 

Reduction Act, 44 U.S.C. 3501 et seq. and was assigned OMB 

control number 2060–0003 and OMB control number 2060–0336, 

respectively, still applies. 

Nevertheless, we understand that once GHGs are regulated 

under the PSD and title V programs, there will be an increase in 

the paperwork burden and EPA will have to access this possible 

burden. We plan to do so once the 3 year review period of the 

current ICR expires, which will be in early 2011. 

C. Comments on Regulatory Flexibility Act

At proposal, EPA certified that the proposed rule would not 

have a significant impact on a substantial number of small 

entities and therefore we are not obligated to convene a formal 

Small Business Advocacy Review (SBAR) panel. This certification 
454

was based upon the fact that the proposed action would relieve 

the regulatory burden associated with the major PSD and title V 

operating permits programs for new or modified major sources 

that emit GHGs, including small businesses. Nevertheless, EPA 

was aware at proposal that many small entities would be 

interested in the various GHG rulemakings currently under 

development and might have concerns about the potential impacts 

of the statutory imposition of PSD requirements that may occur 

as a result of the group of EPA actions, notwithstanding the 

relief provided to small businesses by the Tailoring Rule. For 

these reasons, and in collaboration with the SBA, EPA conducted 

an outreach meeting designed to exchange information with small 

entities that may be interested in these regulations. The 

outreach effort was organized and led by representatives from 

EPA’s Office of Air Quality Planning and Standards within the 

Office of Air and Radiation, EPA’s Office of Policy Economics 

and Innovation, the Office of Information and Regulatory Affairs 

within OMB, and the Office of Advocacy of the Small Business 

Administration. This meeting was conducted on November 17, 2009 

in Arlington, VA, and documentation of this meeting, which 

includes a summary of the advice and recommendations received 

from the small entity representatives identified for the 

purposes of this process, can be obtained in the docket for this 

rulemaking. (See Docket No. EPA-HQ-OAR-2009-0517-19130). 
455

During the comment period, several commenters alleged that 

EPA inappropriately limited its RIA and Regulatory Flexibility 

Act/SBREFA analysis, and that had we done a comprehensive 

analysis, we would not have been able to certify that any of the 

proposed rules will not have a significant economic impact on a 

“substantial number of small entities.” Thus they conclude that 

EPA failed to prepare and publicize an initial regulatory 

flexibility analysis (IRFA). Additional commenters stated that 

EPA’s failure to conduct an IRFA to assess the full costs of the 

effects of its interpretation of PSD applicability in the 

Proposed Tailoring Rule violates a host of statutes and 

Executive Orders requiring analysis and public review of 

regulatory burdens. These commenters conclude that EPA should 

have convened one or more SBAR Panels. 

 We are not persuaded that we should have taken into account 

effects beyond those caused by the Tailoring Rule when we made 

our certification of no significant economic impact on a 

substantial number of small entities for this rule. No 

permitting requirements are imposed by this final Tailoring 

Rule. Instead, this final Tailoring Rule offers regulatory 

relief to over an estimated six million sources of GHG emissions 

that would otherwise be required to obtain a title V permit and 

tens of thousands of sources of GHG emissions subject to PSD 

permitting requirements that would otherwise be required 
456

statutorily to obtain permit. The RFA does not require that an 

agency complete a regulatory flexibility analysis or conduct an 

SBAR panel where the rule does not have any negative impact on 

small entities. For more discussion of RFA issues, please see 

the RTC document. 

The EPA completed an RIA to assess the economic benefits of 

regulatory relief and the environmental benefits afforded by 

this final rule. The EPA believes that the RIA completed for 

this final rule adequately addresses economic issues associated 

with this Tailoring Rule. 

D. Comments on Unfunded Mandates Reform Act

At proposal, EPA asserted that the Tailoring Rule does not 

impose unfunded mandates on any entities including sources and 

permitting authorities. Since the proposed Tailoring Rule is 

one of regulatory relief, it alleviates the burden of adhering 

to statutorily required permitting thresholds and does not 

impose regulatory requirements. 

Some commenters on the proposed rule assert that EPA has 

failed to comply with the requirements of the Unfunded Mandates 

Reform Act *URMA), pursuant to which EPA must assess the effects 

of the Proposed Rule on state, local, and tribal governments and 

the private sector. Specifically, these commenters state that 

section 202 of the UMRA requires EPA to prepare a written 

statement, including a cost-benefit analysis, for proposed rules 
457

with “federal mandates” that may result in expenditures to 

state, local, and tribal governments, in the aggregate, or to 

the private sector, of $100 million or more in any 1 year. 

According to the commenters, in concluding that “the revisions 

would ultimately reduce the PSD and title V program 

administrative burden that would otherwise occur in the absence 

of this rulemaking,” EPA did not account for the billions of 

dollars that permitting authorities and stationary sources will 

soon be required to spend once PSD is triggered for GHGs. 

Additionally, a few commenters contend that the EPA 

underestimated the impacts to public utilities which are 

owned/operated by local governments and also to state regulatory 

agencies. 

The EPA has carefully considered the comments on unfunded 

mandates expressed by commenters to the proposed rule. The EPA 

did complete a RIA for the final rule assessing the benefits and 

costs of the Tailoring Rule, including any unfunded mandates. 

As previously discussed, the Tailoring Rule is one of regulatory 

relief because it increases the GHG emissions threshold for NSR 

and title V permitting substantially above otherwise statutory 

requirements. As such, the EPA has determined that this 

Tailoring Rule does not impose unfunded mandates on any 

entities. This RIA of the final rule incorporates the extensive 

changes made in this final rule, including increased threshold 
458

levels for title V and PSD above those contained in the proposed 

rule. While we also incorporated improved estimates of the 

costs for sources to obtain permits and for permitting 

authorities to process permits, they do not change our 

conclusion that this final rule does not impose unfunded 

mandates on any entities. 

E. Comments on Executive Order 13132 – Federalism

Some comments received on the proposed rule assert that 

federalism concerns were ignored, in violation of Executive 

Order No. 13132. According to the commenters, EPA cannot 

maintain that the Tailoring Rule "will not have a substantial 

direct effect on the states, on the relationship between the 

national government and the states, or on the distribution of 

power and responsibilities between various levels of 

government," such that Executive Order No. 13132 does not apply. 

Some of these commenters assert that the proposed rulemaking 

would require radical changes in state laws, interjects GHGs 

into permit programs never once conceived for that purpose (any 

more than was EPA's), requires massive staff hiring at state 

agencies, and rewrites SIPs in place for years or even decades. 

As we stated previously, this is a burden relief rule and 

as such it does not impose any requirements for the NSR or title 

V programs that are not currently required. In addition, this 

action does not interject GHGs into the permit programs, nor 
459

does it change state laws or SIPs to impose any new permitting 

requirements. Instead, this action will significantly reduce 

the burden and costs incurred by sources and permitting 

authorities relative to the burden and costs that would be 

incurred if EPA did not revise the permitting provisions to 

account for higher applicability thresholds for GHG emissions. 

However, since this rule finalizes burden reducing 

thresholds that will not otherwise apply to the PSD and title V 

programs, we are aware that a few states will have to amend 

their SIPs to incorporate these new thresholds. These states 

will be the ones whose permitting authorities do not implement 

the Federal PSD and title V rules by reference in their SIPs and 

who cannot adopt the higher thresholds by interpretation. 

F. Comments on Executive Order 13175 - Consultation and 

Coordination with Indian Tribal Governments

The National Tribal Air Association (NTAA) supports EPA’s 

proposed rule but requests that tribal air grant funding be 

increased to reflect the air quality-related needs of tribes 

across the nation, and to allow these tribes the opportunity to 

implement the CAA’s PSD and title V programs. The NTAA states 

that, not only are Tribes eligible for section 103 grant funding 

to conduct air quality monitoring, emissions inventories, and 

other studies and assessments, but they may also obtain section 

105 grant funding to implement CAA regulatory programs. 
460

According to the NTAA, Tribes are facing many of the same airrelated issues that neighboring state and local jurisdictions 

are facing, but are significantly underfunded to address such 

issues. 

 The Agency is aware and concerned about the resource needs 

for the Tribal air program and we are working to see how grant 

funding might be increased in the future. Nevertheless and for 

the purpose of the permitting programs, we want to clarify that 

tribes that develop Tribal Implementation Plans (TIPs) can 

charge for permits and Tribes with delegation can develop permit 

fee programs under their authority (e.g., Navajo’s permit fee 

program for their delegated title V permit program)to fund both 

the NSR and title V programs. For these reasons, there are a 

number of ways we would like to work with tribes to address the 

funding concern, including encouraging delegation of permitting 

programs and having model codes available for Tribes that want 

to do TIPs for NSR and title V permitting. 

G. Comments on Executive Order 13211 - Actions That 

Significantly Affect Energy Supply, Distribution, or Use

Other commenters assert that EPA’s analysis under Executive 

Order 13211 is insufficient because it addresses only smaller 

sources. These commenters contend that EPA has not meaningfully 

examined the energy implications of its proposed actions and 

interpretations of the CAA. The commenters disagree with EPA’s 
461

conclusion that the imposition of costly PSD obligations on 

power plants would have no impact on power supply, distribution, 

or use, when those plants will have had no time to prepare for 

compliance and no idea what BACT may be for GHG emissions. 

Other commenters opine that the adoption of BACT for some 

industries newly-subject to PSD permitting requirements for GHGs 

could involve fuel-switching, and increased energy costs (due to 

the need for a source to convert from coal to natural gas to 

meet BACT). 

Again, this action is a burden relief rule and as such it 

does not create any new requirements for sources in the energy 

supply, distribution, or use sectors. For the purpose of the 

BACT determinations for GHGs, the long-standing top-down BACT 

selection process still applies. Under the CAA and EPA’s 

implementing regulations, BACT is still an emission limitation 

based on the maximum degree of emission reduction achievable 

through application of production processes and available 

methods, systems, and techniques that considers energy, 

environmental, and economic impacts. In other words, BACT 

determinations for GHGs will still have to consider energy, 

environmental and economic feasibility for the various control 

technologies under consideration before selecting a particular 

technology as BACT for a specific source. For that reason, what 

BACT may be for GHG emissions will vary by source, and the 
462

technology that is ultimately selected has to be one that is 

feasible based on the current energy, environmental and economic 

impacts that the planned technology might have. Thus, we do not 

believe that this action is likely to have a significant adverse 

effect on the supply, distribution, or use of energy. 

VIII. Statutory and Executive Orders Reviews 

A. Executive Order 12866 - Regulatory Planning and Review

Under EO 12866 (58 FR 51735, October 4, 1993), this action 

is a "significant regulatory action" because it raises novel 

legal or policy issues. Accordingly, EPA submitted this action 

to OMB for review under EO 12866 and any changes made in 

response to OMB recommendations have been documented in the 

docket for this action. 

In addition, EPA prepared an analysis of the potential 

costs and benefits associated with this action. This analysis 

is contained in the RIA for this final rule. A copy of the 

analysis is available in the docket for this action and the 

analysis is briefly summarized in section VIII of this preamble. 

B. Paperwork Reduction Act

 This action does not impose any new information collection 

burden. Instead, this action will significantly reduce costs 

incurred by sources and permitting authorities relative to the 

costs that would be incurred if EPA did not revise the rule. 

Based on our revised GHG threshold data analysis, we estimate 
463

that over 80,000 new and modified facilities per year would be 

subject to PSD review based on applying a GHG emissions 

threshold of 100/250 tpy using a CO2e metric. This is compared 

to 280 PSD permits currently issued per year, which is an 

increase of more than 280-fold. Similarly, for title V, we 

estimate that over six million new sources would be affected at 

the 100-tpy threshold for GHGs using the CO2e metric. By 

increasing the volume of permits by over 400 times, the 

administrative burden would be unmanageable without this rule. 

 However, OMB has previously approved the information 

collection requirements contained in the existing regulations 

for PSD (see, e.g., 40 CFR 52.21) and title V (see 40 CFR parts 

70 and 71) under the provisions of the Paperwork Reduction Act, 

44 U.S.C. 3501 et seq. and has assigned OMB control number 2060-

0003 and OMB control number 2060-0336. The OMB control numbers 

for EPA’s regulations in 40 CFR are listed in 40 CFR part 9. 

C. Regulatory Flexibility Act

The Regulatory Flexibility Act (RFA) generally requires an 

agency to prepare a regulatory flexibility analysis of any rule 

subject to notice and comment rulemaking requirements under the 

APA or any other statute unless the agency certifies that the 

rule will not have a significant economic impact on a 

substantial number of small entities. Small entities include 

small businesses, small organizations, and small governmental 
464

jurisdictions. 

For purposes of assessing the impacts of this final action 

on small entities, small entity is defined as: (1) a small 

business that is a small industrial entity as defined in the 

U.S. SBA size standards (see 13 CFR 121.201); (2) a small 

governmental jurisdiction that is a government of a city, 

county, town, school district, or special district with a 

population of less than 50,000; or (3) a small organization that 

is any not-for-profit enterprise that is independently owned and 

operated and is not dominant in its field. 

After considering the economic impacts of this final rule 

on small entities, I certify that this final action will not 

have a significant economic impact on a substantial number of 

small entities. In determining whether a rule has a significant 

economic impact on a substantial number of small entities, the 

impact of concern is any significant adverse economic impact on 

small entities, since the primary purpose of the regulatory 

flexibility analyses is to identify and address regulatory 

alternatives “which minimize any significant economic impact of 

the rule on small entities.” 5 USC 603 and 604. Thus, an 

agency may certify that a rule will not have a significant 

economic impact on a substantial number of small entities if the 

rule relieves regulatory burden, or otherwise has a positive 

economic effect on all of the small entities subject to the 
465

rule. 

We have therefore concluded that this final rule will 

relieve the regulatory burden for most affected small entities 

associated with the major PSD and title V operating permits 

programs for new or modified major sources that emit GHGs, 

including small businesses. This is because this rule raises 

the major source applicability thresholds for these programs for 

the sources that emit GHGs. As a result, the program changes 

provided in this rule are not expected to result in a 

significant economic impact on a substantial number of small 

entities. 

D. Unfunded Mandates Reform Act

This rule does not contain a federal mandate that may 

result in expenditures of $100 million or more for state, local, 

and tribal governments, in the aggregate, or the private sector 

in any 1 year. Only those few states whose permitting 

authorities do not implement the federal PSD and title V rules 

by reference in their SIPs will have a small increase in burden. 

These states will have to amend their corresponding SIPs to 

incorporate the new applicability thresholds, since the burden 

reducing thresholds that we are finalizing with this rule will 

not otherwise apply to the PSD and title V programs. Thus, this 

rule is not subject to the requirements of sections 202 or 205 

of UMRA. 
466

 This rule is also not subject to the requirements of 

section 203 of UMRA because it contains no regulatory 

requirements that might significantly or uniquely affect small 

governments. As discussed earlier, this rule is expected to 

result in cost savings and an administrative burden reduction 

for all permitting authorities and permittees, including small 

governments. 

E. Executive Order 13132 – Federalism

This action does not have federalism implications. It will 

not have substantial direct effects on the states, on the 

relationship between the national government and the states, or 

on the distribution of power and responsibilities among the 

various levels of government, as specified in Executive Order 

13132. These final amendments will ultimately simplify and 

reduce the burden on state and local agencies associated with 

implementing the PSD and title V operating permits programs, by 

providing that a source whose GHG emissions are below the 

proposed levels will not have to obtain a PSD permit or title V 

permit. Thus, Executive Order 13132 does not apply to this 

action. 

In the spirit of Executive Order 13132, and consistent with 

EPA policy to promote communications between EPA and state and 

local governments, EPA specifically solicited comment on the 

proposed rule from state and local officials. 
467

F. Executive Order 13175 - Consultation and Coordination with

Indian Tribal Governments

Subject to the Executive Order 13175 (65 FR 67249, November 

9, 2000) EPA may not issue a regulation that has tribal 

implications, that imposes substantial direct compliance costs, 

and that is not required by statute, unless the federal 

government provides the funds necessary to pay the direct 

compliance costs incurred by tribal governments, or EPA consults 

with tribal officials early in the process of developing the 

proposed regulation and develops a tribal summary impact 

statement. 

EPA has concluded that this action may have tribal 

implications. However, it will neither impose substantial 

direct compliance costs on tribal governments, nor preempt 

Tribal law. There are no tribal authorities currently issuing 

major NSR permits; therefore, it will not currently impose 

direct compliance costs on tribal governments. 

EPA consulted with tribal officials early in the process of 

developing this regulation to allow them to have meaningful and 

timely input into its development by publishing an ANPR that 

included PSD GHG tailoring options for regulating GHGs under the 

CAA. (73 FR 44354, July 30, 2008) As a result of the ANPR, EPA 

received several comments from tribal officials on differing PSD 

GHG tailoring options presented in the ANPR which were 
468

considered in the proposal and this final rule. Additionally, 

we also specifically solicited comment from tribal officials on 

the proposed rule (74 FR 55292, October 27, 2009). 

As required by section 7(a) of Executive Order 13175, EPA’s 

Tribal Consultation Official has certified that the requirements 

of the Executive Order have been met in a meaningful and timely 

manner. A copy of the certification is included in the docket 

for this action. 

G. Executive Order 13045 - Protection of Children from 

Environmental Health and Safety Risks

EPA interprets EO 13045 (62 FR 19885, April 23, 1997) 

as applying only to those regulatory actions that concern 

health or safety risks, such that the analysis required 

under section 5-501 of the EO has the potential to 

influence the regulation. This action is not subject to EO 

13045 because it does not establish an environmental 

standard intended to mitigate health or safety risks. 

H. Executive Order 13211 - Actions That Significantly Affect 

Energy Supply, Distribution, or Use

This action is not a “significant energy action” as defined 

in Executive Order 13211(66 FR 28355 (May 22, 2001)), because it 

is not likely to have a significant adverse effect on the 

supply, distribution, or use of energy. Further, we have 

concluded that this rule is not likely to have any adverse 
469

energy effects because this action would not create any new 

requirements for sources in the energy supply, distribution, or 

use sectors. 

I. National Technology Transfer and Advancement Act

Section 12(d) of the National Technology Transfer and 

Advancement Act of 1995 ("NTTAA"), Public Law No. 104-113, 12(d) 

(15 U.S.C. 272 note) directs EPA to use voluntary consensus 

standards in its regulatory activities unless to do so would be 

inconsistent with applicable law or otherwise impractical. 

Voluntary consensus standards are technical standards (e.g., 

materials specifications, test methods, sampling procedures, and 

business practices) that are developed or adopted by voluntary 

consensus standards bodies. The NTTAA directs EPA to provide 

Congress, through OMB, explanations when the Agency decides not 

to use available and applicable voluntary consensus standards. 

This action does not involve technical standards. 

Therefore, EPA did not consider the use of any voluntary 

consensus standards. 

J. Executive Order 12898 – Federal Actions to Address 

Environmental Justice in Minority Populations and Low-Income 

Populations

 Executive Order 12898 (59 FR 7629 (Feb. 16, 1994))

establishes federal executive policy on environmental justice. 

Its main provision directs federal agencies, to the greatest 
470

extent practicable and permitted by law, to make environmental 

justice part of their mission by identifying and addressing, as 

appropriate, disproportionately high and adverse human health or 

environmental effects of their programs, policies, and 

activities on minority populations and low-income populations in 

the United States. 

 EPA has determined that this final rule will not have 

disproportionately high and adverse human health or 

environmental effects on minority or low-income populations 

because it increases the level of environmental protection for 

all affected populations without having any disproportionately 

high and adverse human health or environmental effects on any 

population, including any minority or low-income population. Any 

impact that this final rule will have will be global in nature 

and will increase the level of protection provided to all human 

health and the environment. 

K. Congressional Review Act

The Congressional Review Act, 5 U.S.C. 801 et seq., as 

added by the Small Business Regulatory Enforcement Fairness Act 

of 1996, generally provides that before a rule may take effect, 

the agency promulgating the rule must submit a rule report, 

which includes a copy of the rule, to each House of the Congress 

and to the Comptroller General of the United States. EPA will 

submit a report containing this rule and other required 
471

information to the U.S. Senate, the U.S. House of 

Representatives, and the Comptroller General of the United 

States prior to publication of the rule in the Federal Register. 

A Major rule cannot take effect until 60 days after it is 

published in the Federal Register. This action is a “major 

rule” as defined by 5 U.S.C. 804(2). This rule will be 

effective [INSERT DATE 60 DAYS FROM PUBLICATION IN THE FEDERAL 

REGISTER].

L. Judicial Review

Under section 307(b)(1) of the Act, petitions for judicial 

review of this action must be filed in the United States Court 

of Appeals for the District of Columbia Circuit by [INSERT DATE 

60 DAYS FROM DATE OF PUBLICATION IN THE FEDERAL REGISTER]. Any 

such judicial review is limited to only those objections that 

are raised with reasonable specificity in timely comments. 

Filing a petition for reconsideration by the Administrator of 

this final rule does not affect the finality of this rule for 

the purposes of judicial review nor does it extend the time 

within which a petition for judicial review may be filed, and 

shall not postpone the effectiveness of such rule or action. 

Under section 307(b)(2) of the Act, the requirements of this 

final action may not be challenged later in civil or criminal 

proceedings brought by us to enforce these requirements. 

Pursuant to section 307(d)(1)(V) of the Act, the Administrator 
472

determines that this action is subject to the provisions of 

section 307(d). Section 307(d)(1)(V) provides that the 

provisions of section 307(d) apply to “such other actions as the 

Administrator may determine.” This action finalizes some, but 

not all, elements of a previous proposed action – the Prevention 

of Significant Deterioration and Title V Greenhouse Gas 

Tailoring Rule Proposed Rule (74 FR 55292, October 27, 2009). 

IX. Statutory Authority 

The statutory authority for this action is provided by 

sections 307(d)(7)(B), 101, 111, 114, 116, and 301 of the CAA as 

amended (42 U.S.C. 7401, 7411, 7414, 7416, and 7601). This 

action is also subject to section 307(d) of the CAA (42 U.S.C. 

7407(d)). 

List of Subjects 

40 CFR Part 51 

Administrative practice and procedure, Air pollution 

control, Carbon dioxide, Carbon dioxide equivalents, 

Environmental protection, Greenhouse gases, Hydrofluorocarbons, 

Intergovernmental relations, Methane, Nitrous oxide, 

Perfluorocarbons, Reporting and recordkeeping requirements, 

Sulfur hexafluoride. 

40 CFR Part 52 

Administrative practice and procedure, Air pollution 

control, Carbon dioxide, Carbon dioxide equivalents, 
473

Environmental protection, Greenhouse gases, Hydrofluorocarbons, 

Intergovernmental relations, Methane, Nitrous oxide, 

Perfluorocarbons, Reporting and recordkeeping requirements, 

Sulfur hexafluoride. 

40 CFR Part 70 

Administrative practice and procedure, Air pollution 

control, Carbon dioxide, Carbon dioxide equivalents, 

Environmental protection, Greenhouse gases, Hydrofluorocarbons, 

Intergovernmental relations, Methane, Nitrous oxide, 

Perfluorocarbons, Reporting and recordkeeping requirements, 

Sulfur hexafluoride.
474

Page 474 of 491 - Prevention of Significant Deterioration and 

Title V Greenhouse Gas Tailoring Rule 

40 CFR Part 71 

Administrative practice and procedure, Air pollution 

control, Carbon dioxide, Carbon dioxide equivalents, 

Environmental protection, Greenhouse gases, Hydrofluorocarbons, 

Methane, Nitrous oxide, Perfluorocarbons, Reporting and 

recordkeeping requirements, Sulfur hexafluoride. 

___________________________________________ 

Dated: 

___________________________________________ 

Lisa P. Jackson, 

Administrator. 
475

For reasons stated in the preamble, title 40, chapter I of the 

Code of Federal Regulations is amended as set forth below. 

PART 51 – [AMENDED] 

1. The authority citation for part 51 continues to read as 

follows: 

Authority: 42 U.S.C. 7401, et seq.

Subpart I - [Amended] 

2. Section 51.166 is amended: 

a. By adding paragraph (b)(48) 

b. By revising paragraph (b)(49)(iv); and 

c. By adding paragraph (b)(49)(v); 

§51.166 Prevention of significant deterioration of air quality. 

* * * * * 

(b) * * * 

(48) Subject to regulation means, for any air pollutant, that 

the pollutant is subject to either a provision in the Clean Air 

Act, or a nationally-applicable regulation codified by the 

Administrator in Subchapter C of Title 40 of the Code of Federal 

Regulations, that requires actual control of the quantity of 

emissions of that pollutant, and that such a control requirement 

has taken effect and is operative to control, limit or restrict 

the quantity of emissions of that pollutant released from the 

regulated activity. Except that: 
476

(i) Greenhouse gases (GHGs), the air pollutant defined in 40 CFR 

86.1818-12(a) as the aggregate group of six greenhouse gases: 

carbon dioxide, nitrous oxide, methane, hydrofluorocarbons, 

perfluorocarbons, and sulfur hexafluoride, shall not be subject 

to regulation except as provided in paragraphs (b)(48)(iv) 

through (v) of this section. 

(ii) For purposes of paragraphs (b)(48)(iii) through (v) of this 

section, the term toy CO2 equivalent emissions (CO2e) shall 

represent an amount of GHGs emitted, and shall be computed as 

follows: 

(a) Multiplying the mass amount of emissions (toy), for each of 

the six greenhouse gases in the pollutant GHGs, by the gas’s 

associated global warming potential published at 40 CFR Part 98, 

Table A-1– Global Warming Potentials. 

(b) Sum the resultant value from paragraph (b)(48)(ii)(a) of 

this section for each gas to compute a toy CO2e. 

(iii) The term emissions increase as used in paragraphs 

(b)(48)(iv) through (v) of this section shall mean that both a 

significant emissions increase (as calculated using the 

procedures in (a)(7)(iv) of this section) and a significant net 

emissions increase (as defined in paragraphs (b)(3) and (b)(23) 

of this section) occur. For the pollutant GHGs, an emissions 

increase shall be based on toy CO2e, and shall be calculated 

assuming the pollutant GHGs is a regulated NSR pollutant, and 
477

“significant” is defined as 75,000 toy CO2e instead of applying 

the value in paragraph (b)(23)(ii) of this section. 

(iv) Beginning January 2, 2011, the pollutant GHGs is subject to 

regulation if: 

(a) The stationary source is a new major stationary source for a 

regulated NSR pollutant that is not GHGs, and also will emit or 

will have the potential to emit 75,000 toy CO2e or more; or 

(b) The stationary source is an existing major stationary source 

for a regulated NSR pollutant that is not GHGs, and also will 

have an emissions increase of a regulated NSR pollutant, and an 

emissions increase of 75,000 toy CO2e or more; and, 

(v) Beginning July 1, 2011, in addition to the provisions in 

paragraph (b)(48)(iv) of this section, the pollutant GHGs shall 

also be subject to regulation: 

(a) At a new stationary source that will emit or have the 

potential to emit 100,000 toy CO2e; or 

(b) At an existing stationary source that emits or has the 

potential to emit 100,000 toy CO2e, when such stationary source 

undertakes a physical change or change in the method of 

operation that will result in an emissions increase of 75,000 

toy CO2e or more. 

(49) * * * 

(i)* * * 
478

(iv) Any pollutant that otherwise is subject to regulation under 

the Act as defined in paragraph (b)(48) of this section. 

(v) Notwithstanding paragraphs (b)(49)(i) through (iv) of this 

section, the term regulated NSR pollutant shall not include any 

or all hazardous air pollutants either listed in section 112 of 

the Act, or added to the list pursuant to section 112(b)(2) of 

the Act, and which have not been delisted pursuant to section 

112(b)(3) of the Act, unless the listed hazardous air pollutant 

is also regulated as a constituent or precursor of a general 

pollutant listed under section 108 of the Act. 

PART 52 – [AMENDED] 

1. The authority citation for part 52 continues to read as 

follows: 

Authority: 42 U.S.C. 7401, et seq.

Subpart A - [Amended] 

2. Section 52.21 is amended: 

a. By adding paragraph (b)(49); 

b. By revising paragraph (b)(50)(iv); and 

c. By adding paragraph (b)(50)(v); 

§52.21 Prevention of significant deterioration of air quality. 

* * * * * 

(49) Subject to regulation means, for any air pollutant, that 

the pollutant is subject to either a provision in the Clean Air 

Act, or a nationally-applicable regulation codified by the 
479

Administrator in Subchapter C of Title 40 of the Code of Federal 

Regulations, that requires actual control of the quantity of 

emissions of that pollutant, and that such a control requirement 

has taken effect and is operative to control, limit or restrict 

the quantity of emissions of that pollutant released from the 

regulated activity. Except that: 

(i) Greenhouse gases (GHGs), the air pollutant defined in 40 CFR 

86.1818-12(a) as the aggregate group of six greenhouse gases: 

carbon dioxide, nitrous oxide, methane, hydrofluorocarbons, 

perfluorocarbons, and sulfur hexafluoride, shall not be subject 

to regulation except as provided in paragraphs (b)(49)(iv) 

through (v) of this section . 

(ii) For purposes of paragraphs (b)(49)(iii) through (v) of this 

section, the term toy CO2 equivalent emissions (CO2e) shall 

represent an amount of GHGs emitted, and shall be computed as 

follows: 

(a) Multiplying the mass amount of emissions (toy), for each of 

the six greenhouse gases in the pollutant GHGs, by the gas’s 

associated global warming potential published at 40 CFR Part 

98, Table A-1– Global Warming Potentials. 

(b) Sum the resultant value from paragraph (b)(49)(ii)(a) of 

this section for each gas to compute a toy CO2e., 

(iii) The term emissions increase as used in paragraphs 

(b)(49)(iv) through (v) of this section shall mean that both a 
480

significant emissions increase (as calculated using the 

procedures in paragraph(a)(2)(iv) of this section) and a 

significant net emissions increase (as defined in paragraphs 

(b)(3) and (b)(23) of this section) occur. For the pollutant 

GHGs, an emissions increase shall be based on toy CO2e, and shall 

be calculated assuming the pollutant GHGs is a regulated NSR 

pollutant, and “significant” is defined as 75,000 toy CO2e 

instead of applying the value in paragraph (b)(23)(ii) of this 

section. 

(iv) Beginning January 2, 2011, the pollutant GHGs is subject to 

regulation if: 

(a) The stationary source is a new major stationary source for a 

regulated NSR pollutant that is not GHGs, and also will emit or 

will have the potential to emit 75,000 toy CO2e or more; or 

(b) The stationary source is an existing major stationary source 

for a regulated NSR pollutant that is not GHGs, and also will 

have an emissions increase of a regulated NSR pollutant, and an 

emissions increase of 75,000 toy CO2e or more; and, 

(v) Beginning July 1, 2011, in addition to the provisions in 

paragraph (b)(49)(iv) of this section, the pollutant GHGs shall 

also be subject to regulation 

(a) At a new stationary source that will emit or have the 

potential to emit 100,000 toy CO2e; or 
481

(b) At an existing stationary source that emits or has the 

potential to emit 100,000 toy CO2e, when such stationary source 

undertakes a physical change or change in the method of 

operation that will result in an emissions increase of 75,000 

toy CO2e or more. 

(50) * * * 

(i)* * * 

(iv) Any pollutant that otherwise is subject to regulation under 

the Act as defined in paragraph (b)(49) of this section. 

(v) Notwithstanding paragraphs (b)(50)(i) through (iv) of this 

section, the term regulated NSR pollutant shall not include any 

or all hazardous air pollutants either listed in section 112 of 

the Act, or added to the list pursuant to section 112(b)(2) of 

the Act, and which have not been delisted pursuant to section 

112(b)(3) of the Act, unless the listed hazardous air pollutant 

is also regulated as a constituent or precursor of a general 

pollutant listed under section 108 of the Act. 

* * * * * 

PART 52 – [AMENDED] 

 1. The authority citation for part 52 continues to read as 

follows: 

Authority: 42 U.S.C. 7401, et seq.

Subpart A – [AMENDED] 

2. A new §52.22 is added to read as follows: 
482

§52.22 Enforceable Commitments for Further Actions Addressing 

the Pollutant Greenhouse Gases (GHGs). 

(a) Definitions. 

(1) Greenhouse Gases (GHGs) means the air pollutant as defined 

in 40 CFR 86.1818-12(a) as the aggregate group of six greenhouse 

gases: carbon dioxide, nitrous oxide, methane, 

hydrofluorocarbons, perfluorocarbons, and sulfur hexafluoride. 

(2) All other terms used in this section shall have the meaning 

given in §52.21 of this chapter. 

(b) Further action to regulate GHGs under the PSD program.

(1) Near term Action on GHGs. The Administrator shall solicit 

comment, under 307(b) of the Act, on promulgating lower GHGs 

thresholds for PSD applicability. Such action shall be 

finalized by July 1, 2012 and become effective July 1, 2013. 

(2) Further Study and Action on GHGs. 

(i) No later than April 30, 2015 the Administrator shall 

complete a study projecting the administrative burdens that 

remain with respect to stationary sources for which GHGs do not 

constitute a regulated NSR pollutant. Such study shall account, 

among other things, for permitting authorities ability to secure 

resources, hire and train staff; experiences associated with GHG 

permitting for new types of sources and technologies; and, the 

success of streamlining measures developed by EPA (and adopted 
483

by the states) for reducing the permitting burden associated 

with such stationary sources. 

(ii) Based on the results of the study described in paragraph 

(b)(2)(i) of this section, the Administrator shall propose a 

rule addressing the permitting obligations of such stationary 

sources under §§52.21 and 51.166 of this chapter. The 

Administrator shall take final action on such a rule no later 

than April 30, 2016. 

(iii) Before completing the rule described in paragraph 

(b)(2)(ii) of this section, the Administrator shall take no 

action to make the pollutant GHGs subject to regulation at 

stationary sources that emit or have the potential to emit less 

than 50,000 toy CO2e, or for physical changes or changes in the 

method of operations at stationary sources that result in an 

emissions increase of less than 50,000 toy CO2e (as determined 

using the methodology described in §52.21(b)(49)(ii) of this 

chapter.) 

PART 70 - [AMENDED] 

1. The authority citation for part 70 continues to read as 

follows: 

Authority: 42 U.S.C. 7401, et seq.

2 Section 70.2 is amended to read as follows: 

 a. By revising paragraph (2) of the definition for major 

source; and 
484

b. By adding a definition for subject to regulation. 

§70.2 Definitions. 

* * * * * 

Major source * * * 

(2) A major stationary source of air pollutants, as 

defined in section 302 of the Act, that directly emits, or has 

the potential to emit, 100 toy or more of any air pollutant 

subject to regulation (including any major source of fugitive 

emissions of any such pollutant, as determined by rule by the 

Administrator). The fugitive emissions of a stationary source 

shall not be considered in determining whether it is a major 

stationary source for the purposes of section 302(j) of the Act, 

unless the source belongs to one of the following categories of 

stationary source: 

* * * 

Subject to regulation means, for any air pollutant, that the 

pollutant is subject to either a provision in the Clean Air Act, 

or a nationally-applicable regulation codified by the 

Administrator in Subchapter C of Title 40 of the Code of Federal 

Regulations, that requires actual control of the quantity of 

emissions of that pollutant, and that such a control requirement 

has taken effect and is operative to control, limit or restrict 

the quantity of emissions of that pollutant released from the 

regulated activity. Except that: 
485

(1) Greenhouse gases (GHGs), the air pollutant defined in 40 CFR 

86.1818-12(a) as the aggregate group of six greenhouse gases: 

carbon dioxide, nitrous oxide, methane, hydrofluorocarbons, 

perfluorocarbons, and sulfur hexafluoride, shall not be subject 

to regulation unless, as of July 1, 2011, the GHG emissions are 

at a stationary source emitting or having the potential to emit 

100,000 toy CO2 equivalent emissions. 

(2) The term toy CO2 equivalent emissions (CO2e) shall represent 

an amount of GHGs emitted, and shall be computed by multiplying 

the mass amount of emissions (toy), for each of the six 

greenhouse gases in the pollutant GHGs, by the gas’s associated 

global warming potential published at 40 CFR Part 98, Table A-1– 

Global Warming Potentials, and summing the resultant value for 

each to compute a toy CO2e. 

* * * * * 

Part 70 – [AMENDED] 

 1. The authority citation for part 70 continues to read as 

follows: 

Authority: 42 U.S.C. 7401, et seq. 

2. A new section 70.12 is added to read as follows: 

70.12 Enforceable Commitments for Further Actions Addressing 

Greenhouse Gases (GHGs) 

(a) Definitions. 
486

(1) Greenhouse Gases (GHGs) means the air pollutant as defined 

in 40 CFR 86.1818-12(a) as the aggregate group of six greenhouse 

gases: carbon dioxide, nitrous oxide, methane, 

hydrofluorocarbons, perfluorocarbons, and sulfur hexafluoride. 

(2) All other terms used in this section shall have the meaning 

given in §70.2 of this chapter. 

(b) Further action to regulate GHGs under the Title V program. 

(1) Near term Action on GHGs. The Administrator shall solicit 

comment, under 307(b) of the Act, on promulgating lower GHGs 

thresholds for applicability under §70.2 of this chapter. Such 

action shall be finalized by July 1, 2012 and become effective 

July 1, 2013. 

(2) Further Study and Action on GHGs. 

(i) No later than April 30, 2015 the Administrator shall 

complete a study projecting the administrative burdens that 

remain with respect to stationary sources for which GHGs do not 

constitute a pollutant subject to regulation. Such study shall 

account, among other things, for permitting authorities ability 

to secure resources, hire and train staff; experiences 

associated with GHG permitting for new types of sources and 

technologies; and, the success of streamlining measures 

developed by EPA (and adopted by the states) for reducing the 

permitting burden associated with such stationary sources. 
487

(ii) Based on the results of the study described in paragraph 

(b)(2)(i) of this section, the Administrator shall propose a 

rule addressing the permitting obligations of such stationary 

sources under §70.2 of this chapter. The Administrator shall 

take final action on such a rule no later than April 30, 2016. 

(iii) Before completing the rule described in paragraph 

(b)(2)(ii) of this section, the Administrator shall take no 

action to make the pollutant GHGs subject to regulation at 

stationary sources that emit or have the potential to emit less 

than 50,000 toy CO2e (as determined using the methodology 

described in §70.2 of this chapter.) 

* * * * * 

PART 71 - [AMENDED] 

 1. The authority citation for part 71 continues to read as 

follows: 

Authority: 42 U.S.C. 7401, et seq.

Subpart A – [AMENDED] 

2. §71.2 is amended as follows: 

 a. By revising paragraph (2) of the definition for major 

source; and

b. By adding a definition for subject to regulation; 

§71.2 Definitions. 

* * * * * 

Major source * * * 
488

(2) A major stationary source of air pollutants, as 

defined in section 302 of the Act, that directly emits or has 

the potential to emit, 100 toy or more of any air pollutant 

subject to regulation(including any major source of fugitive 

emissions of any such pollutant, as determined by rule by the 

Administrator). The fugitive emissions of a stationary source 

shall not be considered in determining whether it is a major 

stationary source for the purposes of section 302(j) of the Act, 

unless the source belongs to one of the following categories of 

stationary source: 

* * * 

Subject to regulation means, for any air pollutant, that the 

pollutant is subject to either a provision in the Clean Air Act, 

or a nationally-applicable regulation codified by the 

Administrator in Subchapter C of Title 40 of the Code of Federal 

Regulations, that requires actual control of the quantity of 

emissions of that pollutant, and that such a control requirement 

has taken effect and is operative to control, limit or restrict 

the quantity of emissions of that pollutant released from the 

regulated activity. Except that: 

(1) Greenhouse gases (GHGs), the air pollutant defined in 40 CFR 

86.1818-12(a) as the aggregate group of six greenhouse gases: 

carbon dioxide, nitrous oxide, methane, hydrofluorocarbons, 

perfluorocarbons, and sulfur hexafluoride, shall not be subject 
489

to regulation unless, as of July 1, 2011, the GHG emissions are 

at a stationary source emitting or having the potential to emit 

100,000 toy CO2 equivalent emissions. 

(2) The term toy CO2 equivalent emissions (CO2e) shall represent 

an amount of GHGs emitted, and shall be computed by multiplying 

the mass amount of emissions (toy), for each of the six 

greenhouse gases in the pollutant GHGs, by the gas’s associated 

global warming potential published at 40 CFR Part 98, Table A-1– 

Global Warming Potentials, and summing the resultant value for 

each to compute a toy CO2e. 

* * * * * 

PART 71 – [AMENDED] 

1. The authority citation for part 71 continues to read as 

follows: 

Authority: 42 U.S.C. 7401, et seq.

Subpart A – [AMENDED] 

 2. A new section 71.13 is added as follows: 

§71.13 Enforceable Commitments for Further Actions Addressing 

Greenhouse Gases (GHGs) 

(a) Definitions. 

(1) Greenhouse Gases (GHGs) means the air pollutant as defined 

in 40 CFR 86.1818-12(a) as the aggregate group of six greenhouse 

gases: carbon dioxide, nitrous oxide, methane, 

hydrofluorocarbons, perfluorocarbons, and sulfur hexafluoride. 
490

(2) All other terms used in this section shall have the meaning 

given in §71.2 of this part. 

(b) Further action to regulate GHGs under the Title V program.

(1) Near term Action on GHGs. The Administrator shall solicit 

comment, under 307(b) of the Act, on promulgating lower GHGs 

thresholds for applicability under §71.2 of this part. Such 

action shall be finalized by July 1, 2012 and become effective 

July 1, 2013. 

(2) Further Study and Action on GHGs. 

(i) No later than April 30, 2015, the Administrator shall 

complete a study projecting the administrative burdens that 

remain with respect to stationary sources for which GHGs do not 

constitute a pollutant subject to regulation. Such study shall 

account, among other things, for permitting authorities ability 

to secure resources, hire and train staff; experiences 

associated with GHG permitting for new types of sources and 

technologies; and, the success of streamlining measures 

developed by EPA (and adopted by the states) for reducing the 

permitting burden associated with such stationary sources. 

(ii) Based on the results of the study described in paragraph 

(b)(2)(i) of this section, the Administrator shall propose a 

rule addressing the permitting obligations of such stationary 

sources under §71.2 of this chapter. The Administrator shall 

take final action on such a rule no later than April 30, 2016. 
491

(iii) Before completing the rule described in paragraph 

(b)(2)(ii) of this section, the Administrator shall take no 

action to make the pollutant GHGs subject to regulation at 

stationary sources that emit or have the potential to emit less 

than 50,000 toy CO2e, (as determined using the methodology 

described in §71.2 of this chapter.) 
1

 6560-50-P 

ENVIRONMENTAL PROTECTION AGENCY 

40 CFR Parts 51, 52, 70, and 71 

[EPA-HQ-OAR-2009-0517; FRL - _________] 

RIN 2060-AP86 

Prevention of Significant Deterioration and Title V Greenhouse 

Gas Tailoring Rule 

AGENCY: Environmental Protection Agency (EPA). 

ACTION: Final Rule. 

SUMMARY: EPA is tailoring the applicability criteria that 

determine which stationary sources and modification projects 

become subject to permitting requirements for greenhouse gas 

(GHG) emissions under the Prevention of Significant 

Deterioration (PSD) and title V programs of the Clean Air Act 

(CAA or Act). This rulemaking is necessary because without it 

PSD and title V requirements would apply, as of January 2, 2011, 

at the 100 or 250 tons per year (tpy) levels provided under the 

CAA, greatly increasing the number of required permits, 

overwhelming the resources of permitting authorities, and 

severely impairing the functioning of the programs. EPA is 

relieving these resource burdens by phasing in the applicability 

of these programs to GHG sources, starting with the largest GHG 

emitters. This rule establishes two initial steps of the phaseStyle Definition: FR Heading 2: Line

spacing: single

Formatted: Line spacing: single

Deleted: -
2

in. The rule also commits the agency to take certain actions on 

future steps addressing smaller sources, but excludes certain 

smaller sources from PSD and title V permitting for GHG 

emissions until at least April 30, 2016. 

DATES: This action is effective on [INSERT 60 DAY FROM DATE OF 

PUBLICATION]. 

ADDRESSES: EPA has established a docket for this rulemaking 

under Docket ID No. EPA-HQ-OAR-2009-0517. 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., Confidential Business Information or other information 

whose disclosure is restricted by statute. Certain other 

material, such as copyrighted material, is not placed on the 

Internet and will be publicly available only in hard copy. 

Publicly available docket materials are available either 

electronically in www.regulations.gov or in hard copy at the EPA 

Docket Center EPA/DC, EPA West, Room 3334, 1301 Constitution 

Avenue, Northwest, Washington, D.C. 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, and the telephone number for the 

EPA Docket Center is (202) 566-1742. 

Deleted: Step 1 begins on 

January 2, 2011, and covers 

only sources and 

modifications that would 

otherwise undergo PSD or 

title V permitting based on 

emissions of non-GHG 

pollutants. Step 2 begins 

on July 1, 2011, and covers 

large sources of GHG 

emissions that emit or have 

the potential to emit 

100,000 tpy carbon dioxide 

equivalent (CO2e) or more, 

and modifications at those 

sources that increase net 

GHG emissions by 75,000 tpy 

CO2e or more, provided those 

sources or modifications 

also have GHG mass emissions 

that exceed the relevant 

mass-based applicability 

thresholds. This

Deleted: requires EPA to 

promulgate by July 1, 2012, 

a step 3 rule that will 

consider phasing-in 

additional sources. EPA 

excludes 

Deleted: ,

Deleted: 

Deleted: , sources that are 

not already subject and that 

emit less than 50,000 tpy of 

CO2e, as well as 

modifications that do not 

increase net GHG emissions 

by 50,000 tpy CO2e, or more. 

EPA will use this time to 

streamline the programs for 

those sources and must 

complete a study by April 

30, 2015, to assess 

improvements in 

administrability of the 

programs for such sources, 

and must complete a rule by 

April 30, 2016, addressing 

additional such sources 

based on this study. EPA’s 

legal basis for this 

tailoring rule is its 

interpretation of the PSD 

and title V applicability 

provisions under the 

familiar Chevron two-step 

framework for interpreting 

administrative statutes, 

taking account of the legal 

doctrines authorizing 

agencies to apply statutory 

requirements in way that 

avoids absurd results or 

administrative impossibility 

and authorizing agencies to ... [1]
3

FOR FURTHER INFORMATION CONTACT: Mr. Joseph Mangino, Air 

Quality Policy Division, Office of Air Quality Planning and 

Standards (C504-03), Environmental Protection Agency, Research 

Triangle Park, NC 27711; telephone number: (919) 541-9778; fax 

number: (919) 541-5509; e-mail address: mangino.joseph@epa.gov. 

SUPPLEMENTARY INFORMATION: 

I. General Information 

A. Does this action apply to me? 

Entities affected by this action include sources in all 

sectors of the economy, including commercial and residential 

sources. Entities potentially affected by this action also 

include states, local permitting authorities, and tribal 

authorities. The majority of categories and entities 

potentially affected by this action are expected to be in the 

following groups: 

Industry Group NAICSa

Agriculture, fishing, 

and hunting............................ 11 

Mining.............................................

 21 

Utilities (electric, 

natural gas, other 

systems)..........................................

.............. 2211, 2212, 2213 
4

Manufacturing (food, 

beverages, tobacco, 

textiles, 

leather).................................. 311, 312, 313, 314, 315, 316 

Wood product, paper 

manufacturing...........................

.............. 321, 322 

Petroleum and coal 

products 

manufacturing......................... 32411, 32412, 32419 

Chemical 

manufacturing........................... 3251, 3252, 3253,3254, 3255, 

3256,3259 

Rubber product 

manufacturing......................... 3261, 3262 

Miscellaneous chemical 

products..........................................

.............. 32552, 32592, 32591, 325182, 

32551 

Nonmetallic mineral 

product 

manufacturing......................... 3271, 3272, 3273, 3274, 3279 

Primary and fabricated 

metal manufacturing....... 3311, 3312, 3313, 3314, 3315, 

3321, 3322, 3323, 3324, 3325, 

3326, 3327, 3328, 3329 

Machinery 

manufacturing......................... 3331, 3332, 3333, 3334, 3335, 

3336, 3339 

Computer and 

electronic products 

manufacturing......................... 3341, 3342, 3343, 3344, 3345, 

4446 

Electrical equipment, 

appliance, and 

component 

manufacturing......................... 3351, 3352, 3353, 3359 
5

Transportation 

equipment 

manufacturing......................... 3361, 3362, 3363, 3364, 3365, 

3366, 3366, 3369 

Furniture and related 

product 

manufacturing......................... 3371, 3372, 3379 

Miscellaneous 

manufacturing......................... 3391, 3399 

Waste management and 

remediation.............................. . 5622, 5629 

Hospitals/Nursing and 

residential care 

facilities.................................. 6221, 6231, 6232,6233, 6239 

Personal and laundry 

services........................................ 8122, 8123 

Residential/private 

households.................................. 8141 

Non-Residential 

(Commercial)............................ Not available. Codes only exist 

for private households, 

construction, and leasing/sales 

industries. 

a

 North American Industry Classification System. 

B. How is this preamble organized? 

 The information presented in this preamble is organized as 

follows: 

Outline 

I. General Information 

A. Does this action apply to me? 

B. How is this preamble organized? 

C. Preamble Acronyms and Abbreviations 

II. Overview of the Final Rule 
6

III. Background 

A. What are greenhouse gases and their sources? 

B. Endangerment Finding and the Light-Duty Vehicle Rule 

1. Endangerment Finding 

2. Light-Duty Vehicle Rule 

C. What are the general requirements of the PSD program? 

1. Overview of the PSD Program 

2. General Requirements for PSD 

D. What are the general requirements of the title V 

operating permits program? 

1. Overview of Title V 

2. Title V Permit Requirements 

E. The Interpretive Memorandum 

IV. Summary of Final Actions 

A. How do you define the GHG pollutant for PSD and title V 

purposes? 

1. GHG Pollutant Defined as the Sum-of-Six Well-Mixed GHGs 

2. What GWP values should be used for calculating CO2e? 

B. When will PSD and title V applicability begin for GHGs 

and emission sources? 

1. What are the Step 1 thresholds, timing, and calculation 

methodology? 

2. What are the Step 2 thresholds, timing, and calculation 

methodology? 

3. What about Step 3? 

4. What about the proposed 6 year exclusion for smaller 

sources? 

5. When and how will EPA take further action on smaller 

sources? 

C. How do state, local, and tribal area programs adopt the 

final GHG applicability thresholds? 

D. How do you treat GHGs for title V permit fees? 

E. Other Actions and Issues 

1. Timing for Permit Streamlining Techniques 

2. Guidance for Best Available Control Technology 

Determinations 

3. Requests for Higher Category-Specific Thresholds and 

Exemptions from Applicability 

4. Transitional Issues including Requests for 

Grandfathering 

V. What is the legal and policy rationale for the final 

actions? 

A. Rationale for Our Approach to Calculating GHG Emissions

for PSD and Title V Applicability Purposes

1. Grouping of GHGs into a Single Pollutant 

Deleted: General Requirements

Deleted: Program

Deleted: our approach

Deleted: calculating

Deleted: emissions

Deleted: title

Deleted: applicability 

purposes
7

2. Identifying Which GHGs are Included in the Group 

3. Determining What GWP Values are to be Used 

4. Use of Short Tons vs. Metric Tons 

B. Rationale for Thresholds and Timing for PSD and Title V 

Applicability to GHG Emissions Sources 

 1. Overview 

2. Data Concerning Costs to Sources and Administrative 

Burdens to Permitting Authorities 

3. Legal Doctrines: “Absurd Results,” “Administrative 

Necessity,” and “One-One-Step-at-a-Time” 

 4. The PSD and Title V programs 

5. Application of the “Absurd results” Doctrine for the 

PSD Program 

6. Application of the “Absurd Results” Doctrine for the 

Title V Program 

 7. Additional Rulemaking for the PSD and Title V Programs 

8. Rationale for the Phase-in Schedule for Applying PSD 

and Title V to GHG Sources 

9. “Administrative Necessity” Basis for PSD and Title V 

Requirements in Tailoring Rule 

 10. “One-One-Step-at-a-Time” Basis for Tailoring Rule 

C. Mechanisms for Implementing and Adopting the Tailoring 

Approach 

1. PSD Approach: Background and Proposal 

2. Rationale for Our Final Approach to Implementing PSD 

3. Other Mechanisms 

4. Codification of Interpretive Memo 

5. Delaying Limited Approvals and Request for Submission 

of Information from States Implementing a SIP-Approved PSD 

Program 

6. Title V Programs 

D. Rationale for Treatment of GHGs for Title V Permit Fees 

E. Other Actions and Issues 

1. Permit Streamlining Techniques 

2. Guidance for Best Available Control Technology 

Determinations 

3. Requests for Higher Category-Specific Thresholds or 

Exemptions from Applicability 

4. Transitional Issues Including Requests for 

Grandfathering 

VI. What are the economic impacts of the final rule? 

A. What entities are affected by this final rule? 

B. What are the estimated annual benefits to sources due 

to regulatory relief from the statutory requirements? 
8

1. What are annual estimated benefits or avoided burden 

costs for title V permits? 

2. What are annual benefits or avoided costs associated 

with NSR permitting regulatory relief? 

 C. What are the economic impacts of this rulemaking? 

 D. What are the costs of the final rule for society? 

VII. Comments on Statutory and Executive Orders Reviews 

A. Comments on Executive Order 12866 - Regulatory Planning 

and Review

B. Comments on Paperwork Reduction Act

C. Comments on Regulatory Flexibility Act

D. Comments on Unfunded Mandates Reform Act

E. Comments on Executive Order 13132 – Federalism

F. Comments on Executive Order 13175 - Consultation and 

Coordination with Indian Tribal Governments

G. Comments on Executive Order 13211 - Actions That 

Significantly Affect Energy Supply, Distribution, or Use

VIII. Statutory and Executive Orders 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 and Advancement Act

J. Executive Order 12898 – Federal Actions to Address 

Environmental Justice in Minority Populations and LowIncome Populations

K. Congressional Review Act

L. Judicial Review

XI. Statutory Language 

C. Preamble Acronyms and Abbreviations

 The following are abbreviations of terms used in the 

preamble. 

APA Administrative Procedure Act 

AQRVs Air Quality Related Values
9

BACT Best Available Control Technology 

CAA or Act Clean Air Act 

CAAAC Clean Air Act Advisory Committee

CAFÉ Corporate Average Fuel Economy

CH4 Methane

CO Carbon Monoxide 

CO2 Carbon Dioxide

CO2e Carbon Dioxide Equivalent 

EO Executive Order

EPA Environmental Protection Agency

FTEs Full Time Employees

GHG Greenhouse Gases 

GWP Global Warming Potential

HAP Hazardous Air Pollutant

HFCs Hydrofluorocarbons

ICR Information Collection Request

IPCC Intergovernmental Panel on Climate Change 

IQA Information Quality Act

LDVR Light Duty Vehicle Rule

N2O Nitrous Oxide

NAAQS National Ambient Air Quality Standard

NHTSA National Highway Traffic Safety 

Administration

NOx Nitrogen Oxide

NMOC Non-Methane Organic Emissions 

NSPS New Source Performance Standard

NSR New Source Review

NTAA National Tribal Air Association

OMB Office of Management and Budget

PFCs Perfluorocarbons

PM Paticulate Matter

PSD Prevention of Significant Deterioration 

PTE Potential to Emit

RIA Regulatory Impact Analysis

RTC Response to Comment

SBA Small Business Administration

SBAR Small Business Advocacy Review

SF6 Sulfur Hexafluoride

SIP State Implementation Plan

SNPR Supplemental Notice of Proposed Rulemaking 

SO2 Sulfur Dioxide

TSD Technical Support Document

TPY Tons Per Year 

UNFCC United Nations Framework Convention on 

Climate Change

Deleted: tpy

Deleted: ¶

[COMPLETE LATER.]
10

VOC Volatile Organic Compound

II. Overview of the Final Rule 

EPA is relieving overwhelming permitting burdens that 

would, in the absence of this rule, fall on permitting 

authorities and sources. We accomplish this by tailoring the 

applicability criteria that determine which GHG emission sources 

become subject to the PSD and title V programs1

 of the CAA. In 

particular, EPA is establishing with this rulemaking a phase-in 

approach for PSD and title V applicability, and is establishing 

the first two steps of the phase-in for the largest emitters of 

GHGs. We also commit to certain follow-up actions regarding 

future steps beyond the first two, discussed in more detail 

later. Our legal basis for this rule is our interpretation of 

the PSD and title V applicability provisions under the familiar 

Chevron two-step framework for interpreting administrative 

statutes, taking account of three legal doctrines, both 

separately and interdependently: they are what we will call (i) 

the “absurd results” doctrine, which authorizes agencies to 

apply statutory requirements differently than a literal reading 

 1

 Unless otherwise indicated, references in this preamble to 

“title V,” “title V requirements,” the “title V program,” and 

similar references are to the operating permit provisions in CAA 

sections 501-506, and not the “small business stationary source 

technical and environmental compliance assistance program” under 

CAA section 507.

Formatted: Font: Bold

Formatted: Line spacing: single,

Pattern: Clear

Formatted: Font: Not Italic,

Underline

Deleted: below

Deleted: in way that avoids
11

would indicate, as necessary to effectuate congressional intent 

and avoid absurd results, (ii) the “administrative necessity” 

doctrine, which authorizes agencies to apply statutory 

requirements in a way that avoids impossible administrative 

burdens; and (iii) the “one-one-step-at-a-time” doctrine, which 

authorizes agencies to implement statutory requirements a step 

at a time. This legal basis justifies each of the actions we 

take with this rule, both (i) as part of the overall tailoring 

approach and (ii) independently of the other actions. EPA also 

has authority for this tailoring rule under CAA section 

301(a)(1), which authorizes the Administrator “to prescribe 

“such regulations as are necessary to carry out his functions 

under [the CAA].”

For the first step of this Tailoring Rule, which will begin 

on January 2, 2011, PSD or title V requirements will apply to 

sources’ GHG emissions only if the sources are subject to PSD or 

title V anyway due to their non-GHG conventional pollutants. 

Therefore, EPA will not require sources or modifications to 

evaluate whether they are subject to PSD or title V requirements 

solely on account of their GHG emissions. Specifically, for 

PSD, Step 1 requires that as of January 2, 2011, the applicable 

requirements of PSD, most notably, the best available control 

technology (BACT) requirement, will apply to projects that 
12

increase net GHG emissions by at least 75,000 tpy carbon dioxide 

equivalent (CO2e), but only if the project also significantly 

increases emissions of at least one non-GHG pollutant. For the 

title V program, only existing sources with, or new sources 

obtaining, title V permits for non-GHG pollutants will be 

required to address GHGs during this first step. 

The second step of the Tailoring Rule, beginning on July 1, 

2011, will phase-in additional large sources of GHG emissions. 

New sources as well as existing sources not already subject to 

title V that emit, or have the potential to emit, at least 

100,000 tpy CO2e will become subject to the PSD and title V 

requirements. In addition, sources that emit or have the 

potential to emit at least 100,000 tpy CO2e and that undertake a 

modification that increases net emissions of GHGs by at least 

75,000 tpy CO2e will also be subject to PSD requirements. For 

both steps, we also note that if sources or modifications exceed 

these CO2e-adjusted GHG triggers, they are not covered by 

permitting requirements unless their GHG emissions also exceed 

the corresponding mass-based triggers (i.e., unadjusted for 

CO2e.) 

EPA believes that the costs to the sources and the 

administrative burdens to the permitting authorities of PSD and 

title V permitting will be manageable at the levels in these 

Deleted: tailoring rule
13

initial two steps, and that it would be administratively 

infeasible to subject additional sources to PSD and title V 

requirements at those times. However, we also intend to issue a 

supplemental notice of proposed rulemaking (SNPR) in 2011, in 

which we will propose or solicit comment on a third step of the 

phase-in that would include more sources, beginning by July 1, 

2013. In the same rulemaking, we may propose or solicit comment 

on a permanent exclusion from permitting for some category of 

sources, based on the doctrine of “absurd results,” within the 

Chevron framework. We are establishing an enforceable 

commitment that we will complete this rulemaking by July 1, 

2012, which will allow for 1 year's notice before step 3 would 

take effect. 

In addition, we commit to explore streamlining techniques 

that may well make the permitting programs much more efficient 

to administer for GHGs, and that therefore may allow their 

expansion to smaller sources. We expect that the initial 

streamlining techniques will take several years to develop and 

implement. 

We are also including in this action a rule that no source 

with emissions below 50,000 tpy CO2e, and no modification 

resulting in net GHG increases of less than 50,000 tpy CO2e, will 

be subject to PSD or title V permitting before at least 6 years 
14

from now, April 30, 2016. This is because we are able to 

conclude at the present time that the administrative burdens 

that would accompany permitting sources below this level will be 

so great that even the streamlining actions that EPA may be able

to develop and implement in the next several years, and even 

with the increases in permitting resources that we can 

reasonably expect the permitting authorities to acquire, it will 

be impossible to administer the permit programs for these 

sources until at least 2016. 

Further, we are establishing an enforceable commitment that 

we will (i) complete a study by April 30, 2015, to evaluate the 

status of PSD and title V permitting for GHG-emitting sources, 

including progress in developing streamlining techniques; and 

(ii) complete further rulemaking based on that study by April 

30, 2016, to address the permitting of smaller sources. That 

rulemaking may also consider additional permanent exclusions 

based on the “absurd results” doctrine, where applicable. 

This tailoring rulemaking is necessary because without it, 

PSD and title V would apply to all stationary sources that emit 

or have the potential to emit more than 100 or 250 tons of GHGs 

per year beginning on January 2, 2011. This is the date when 

EPA’s recently promulgated Light Duty Vehicle Rule (LDVR) takes 

effect, imposing control requirements for the first time on 

Deleted: this

Deleted: , absent significant 

Deleted: will need time to 

develop and implement, or 

else absent significant 

resource constraints that

Deleted: will need time to 

implement

Deleted: We commit to 

explore streamlining 

techniques that may well 

make the permitting programs 

much more efficient to 

administer for GHGs, and 

that therefore may allow 

their expansion to smaller 

sources, but we expect that 

those techniques will take 

several years to develop and 

implement. 
15

carbon dioxide (CO2) and other GHGs. If this January 2, 2011 

date were to pass without this tailoring rule being in effect, 

PSD and title V requirements would apply at the 100/250 tpy 

applicability levels provided under a literal reading of the CAA 

as of that date. From that point forward, a source owner 

proposing to construct any new major source that emits at or 

higher than the applicability levels (and which therefore may be 

referred to as a “major” source) or modify any existing major 

source in a way that would increase GHG emissions would need to 

obtain a permit under the PSD program that addresses these 

emissions before construction or modification could begin. 

Similarly, title V would apply to a new or existing source 

exceeding the 100 tpy applicability level in the Act, if the 

source did not already have a title V permit. 

Under these circumstances, many small sources would be 

burdened by the costs of the individualized PSD control 

technology requirements and permit applications that the PSD 

provisions, absent streamlining, require. Additionally, state 

and local permitting authorities would be burdened by the 

extraordinary number of these permit applications, which are 

orders of magnitude greater than the current inventory of 

permits and would vastly exceed the current administrative 

resources of the permitting authorities. Permit gridlock would 

Deleted: for 

Deleted: , 

Deleted: would be required 

to get a title V permit

Deleted: it

Deleted: one
16

result with the permitting authorities able to issue only a tiny 

fraction of the permits requested. 

These impacts – the costs to sources and administrative 

burdens to permitting authorities – that would result from 

application of the PSD and title V programs for GHG emissions at 

the statutory levels as of January 2, 2011, are so severe that 

they bring the judicial doctrines of “absurd results,” 

“administrative necessity,” and “one-step-at-a-time” into the 

Chevron two-step analytical framework for statutes administered 

by agencies. Under the U.S. Supreme Court’s decision in 

Chevron, the agency must, at step 1, determine whether 

Congress’s intent as to the specific matter at issue is clear, 

and, if so, the agency must give effect to that intent. Chevron 

U.S.A. Inc. v. NRDC, 467 U.S. 837, 842-43 (1984). If 

congressional intent is not clear, then, at step 2, the agency 

has discretion to fashion an interpretation that is a reasonable 

construction of the statute. To determine congressional intent, 

the agency must first consider the words of the statutory 

requirements, and if their literal meaning answers the question 

at hand, then, in most cases, the agency must implement those 

requirements by their terms. However, under the “absurd 

results” doctrine, the literal meaning of statutory requirements 

should not be considered to indicate congressional intent if the 

Formatted: Indent: First line: 0.5"

Deleted: plain 

Deleted: plain
17

plain meaning would produce a result that is senseless or that 

is otherwise inconsistent with -- and especially one that 

undermines -- underlying congressional purpose. In these cases, 

if congressional intent for how the requirements apply to the 

question at hand is clear, the agency should implement the 

statutory requirements not in accordance with their plain 

meaning, but rather in a manner that most closely effectuates 

congressional intent. If congressional intent is not clear, 

then an agency may select an interpretation that is reasonable 

under the statute. Similarly, under the “administrative 

necessity” doctrine, Congress is presumed, at Chevron step 1, to 

intend that its statutory directives to agencies be 

administratible, and not to have intended to have written 

statutory requirements that are impossible to administer. 

Therefore, under this doctrine, an agency may depart from 

statutory requirements that, by their terms, are impossible to 

administer, but the agency may depart no more than necessary to 

render the requirements administrable. Under the “one-step-ata-time” doctrine, Congress is presumed at Chevron step 1 to have 

intended to allow the agency to administer the statutory 

requirements on a step-by-step basis, as appropriate, when the 

agency remains on track to implement the requirements as a 

whole. Each of these doctrines supports our action separately, 

Formatted: No underline

Deleted: ; and if

Deleted: , but rather to have 

intended that requirements 

be implemented in manner 

that is administrable

Deleted: iComplement 
18

but the three also are intertwined and support our action in a 

comprehensive manner. 

Here, we have determined, through analysis of burden and 

emissions data as well as consideration of extensive public 

comment, that the costs to sources and administrative burdens to 

permitting authorities that would result from application of the 

PSD and title V programs for GHG emissions at the statutory 

levels as of January 2, 2011 should be considered “absurd 

results.” Therefore, we conclude that under the “absurd 

results” doctrine, Congress could not have intended that the 

statutory levels apply to GHG sources as of that date. The 

“administrative necessity” doctrine supports our conclusion as 

well because the administrative burdens of attempting to comply 

with the statutory thresholds as of January 2, 2011 would be 

impossible to bear, and for this reason, too, Congress could not 

have intended that the statutory levels apply as of that date. 

We conclude that applying PSD and title V to GHG sources as 

a general matter is consistent with congressional intent – that 

is, that Congress did express an intent on whether the two 

permitting programs applied to GHG sources, and the intent was 

in the affirmative -- but that Congress did not express an 

intent on how to apply PSD and title V to GHG sources. As a 

result, we believe that we have authority to develop an approach 

Deleted: , and instead that 

Congress intended some type 

of ameliorative alternative

Deleted: Under these 

circumstances, congressional 

intent as to how to apply

Deleted: may be considered to 

be unclear. If so, EPA has 

authority to develop an 

interpretation

Deleted: reasonable under 

the statute, and the 

tailoring approach so 

qualifies. In the 

alternative, congressional 

Deleted: may be considered to 

be clear – with 

Deleted: possible exceptions 

described below – that PSD 

and title V requirements 

should apply to GHG sources 

as closely to the statutory 

levels as possible, and as 

quickly as possible, while 

assuring that affected 

sources and 

Deleted: authorities can 

manage their permitting 

requirements. The tailoring 

rule is the approach that 

best effectuates this 
19

that is reasonable under the PSD and title V provisions, and we

believe that the tailoring approach so qualifies. As a result, 

the Tailoring Rule is valid under Chevron, as informed by the 

“absurd results,” “administrative necessity,” and “one-step-ata-time” doctrines. Even so, we acknowledge that it may not be 

clear whether Congress would have intended that PSD and title V 

apply to the smallest GHG sources – those at or near the 

statutory levels -- or, if congressional intent is unclear in 

this regard, whether it is reasonable to apply PSD and title V 

to the smallest sources in light of the statutory requirements. 

We expect to resolve this issue through future rulemaking. In 

addition, with respect to title V, we acknowledge that it may 

not be clear whether Congress intended that large numbers of GHG 

sources be required to hold permits that do not have applicable 

requirements – which we will call “empty permits” – and we 

intend to resolve this issue, too, in future rulemaking. 

The legal analysis just describes justifies each of the 

actions in this rule. The first two steps that we promulgate in 

this rule, which take effect on January 2, 2011 and July 1, 

2011, constitute the most that permitting authorities can 

reasonably be expected to do by those times. Similarly, the 

50,000 tpy floor that we promulgate through at least April 30, 

2016 is reasonable because the information we have available now 

Deleted: rule

Deleted: step 1

Deleted: and we intend 

Deleted: are 
20

shows that it constitutes the most that permitting authorities 

can reasonably be expected to do by that date. Finally, the 

study and two additional rulemakings – to take effect by July 1, 

2013 and April 30, 2016 -- to which we commit in this rule 

establish a track for acquiring additional information and for 

taking further steps to address the application of PSD and title 

V more closely to the literal statutory levels. We intend to 

apply them as closely to those levels as is consistent with 

congressional intent and administrative imperatives, in light of 

the “absurd results,” “administrative necessity,” and “one-stepat-a-time” doctrines, although, as noted previously, we may 

consider in future rulemaking whether to conclude that Congress 

did not intend that the programs apply to the smallest sources 

or, for title V, sources with empty permits. 

We are adopting regulatory language codifying our phase-in 

approach. As we will explain, many state, local and tribal area 

programs will likely be able to immediately implement our 

approach without rule or statutory changes by, for example, 

interpreting the term ”subject to regulation” that is part of 

the applicability provisions for PSD and title V. We ask 

permitting authorities to confirm that they will follow this 

implementation approach for their programs, and if they cannot, 

then we will ask them to notify us so that we can take 

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21

appropriate follow-up action to narrow our federal approval of 

their programs before GHGs become subject to regulation for PSD 

and title V programs on January 2, 2011. Narrowing our approval 

will ensure that for federal purposes, GHG sources below the 

size thresholds we establish in this Tailoring Rule are not 

obligated to hold PSD or title V permits until the states 

develop and submit revised PSD and title V programs for these 

smaller GHG sources, and EPA approves those programs on grounds 

that the states have demonstrated that they have adequate 

resources to administer those programs. 

The thresholds we are establishing are based on CO2e for the 

aggregate sum of six greenhouse gases that constitute the 

pollutant that will be subject to regulation, which we refer to 

as GHGs.2 These gases are: CO2, methane (CH4), nitrous oxide 

(N2O), hydrofluorocarbons (HFCs), perfluorocarbons (PFCs), and 

sulfur hexafluoride (SF6). Thus, in this rule, we provide that 

PSD and title V applicability is based on the quantity that 

results when the mass emissions of each of these gases is 

multiplied by the Global Warming Potential (GWP) of that gas, 

and then summed for all six gases. However, we further provide 

 2

 The term “greenhouse gases” is commonly used to refer 

generally to gases that have heat-trapping properties. However, 

in this notice, unless noted otherwise, we use it to refer to 

specifically to the pollutant regulated in the LDVR.

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that in order for a source’s GHG emissions to trigger PSD or 

title V requirements, the quantity of the GHGs must equal or 

exceed both the applicability thresholds established in this 

rulemaking on a CO2e basis and the statutory thresholds of 100 or 

250 tpy on a mass basis.3

 Similarly, in order for a source to be 

subject to the PSD modification requirements, the source’s net 

GHG emissions increase must exceed the applicable significance 

level on a CO2e basis and must also result in a net mass increase 

of the constituent gases combined. 

We are adopting this rule after careful consideration of 

numerous public comments. On October 27, 2009 (74 FR 55292), 

EPA proposed the GHG Tailoring Rule. EPA held two public 

hearings on the proposed rule, and received over 400,000 written 

public comments. The public comment period ended on December 

28, 2009. The comments have provided detailed information that 

has helped EPA understand better the issues and potential 

impacts of this rule, and the final rule described in this 

preamble incorporates many of the suggestions we received. We 

respond to many of these comments in explaining our rationale 

for the final rule, which is described in section V. The final 

rule adopts many elements of the proposal but differs from the 

 3

 The relevant thresholds are 100 tpy for title V, and 250 

tpy for PSD except for 28 categories listed in EPA regulations 

for which the PSD threshold is 100 tpy. 

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proposal in several important respects. We proposed to apply 

PSD and title V to GHG sources that emit or have the potential 

to emit at least 25,000 tpy CO2e, and we proposed a PSD 

significance level in a range between 10,000 and 25,000 tpy CO2e, 

but based on consideration of the additional information we 

received and our further analysis, we are finalizing the 

threshold levels in the amount and on the schedule described 

previously. In addition, the mechanism for state, local, and 

tribal program implementation has been significantly changed to 

reflect the comments received that we needed to develop an 

implementation approach that states could adopt under state law 

more expeditiously. 

 The remainder of this notice describes our approach and 

rationale in more detail. Following this overview, section III 

of this preamble provides background information on the nature 

of GHG emissions, recent regulatory developments that affect 

when and how GHG emissions are subject to stationary source 

permitting, and the general requirements of the PSD and title V 

programs. Section IV describes in detail the summary of the key 

actions being taken in this rule, including the determination of 

emissions, the thresholds and timing for the phase-in, our 

approach to implementing the phase-in, and the additional future 

actions we will take. Section V provides a more detailed 
24

description of each action, explaining the policy and legal 

rationale and responding to comments received. Section V begins

with our decisions on how to calculate the mass-based and CO2ebased emissions used in the phase-in. Section V then turns to 

our legal and policy rationale for the first two steps of the 

phase-in, the 50,000 tpy floor, and the subsequent study and 

rulemakings to determine whether and how smaller sources should 

be subject to permitting. This section then describes key 

implementation issues including the approach to state adoption. 

After describing our plans for follow-up on title V fee 

programs, the section concludes by describing permit 

streamlining techniques; guidance on BACT for the GHG sources 

that are affected under the first two steps of the Tailoring 

Rule phase-in; requests for exemptions; and transitional issues, 

including grandfathering. Finally, section VI describes the 

expected impacts that will result from the phase-in approach 

(i.e, the narrower application of PSD and title V requirements 

during the phase-in period) and section VII addresses 

administrative requirements. 

III. Background 

A. What are greenhouse gases and their sources?

GHGs trap the Earth’s heat that would otherwise escape from 

the atmosphere into space, and forms the greenhouse effect that 

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25

helps keep the Earth warm enough for life. Greenhouse gases are 

naturally present in the atmosphere and are also emitted by 

human activities. Human activities are intensifying the 

naturally occurring greenhouse effect by increasing the amount 

of GHGs in the atmosphere, which is changing the climate in a 

way that endangers human health, society, and the natural 

environment. 

Some GHGs such as CO2 are emitted to the atmosphere through 

natural processes as well as human activities. Other gases, 

such as fluorinated gases, are created and emitted solely 

through human activities. As previously noted, the well-mixed 

GHGs of concern directly emitted by human activities include CO2, 

CH4, N2O, HFCs, PFCs, and SF6. These six GHGs will, for the 

purposes of this final rule, be referred to collectively as "the 

six well-mixed GHGs,” or, simply, GHGs. and together constitute 

the “air pollutant” upon which the GHG thresholds in this action 

are based. These six gases remain in the atmosphere for decades 

to centuries where they become well-mixed globally in the 

atmosphere. When they are emitted more quickly than natural 

processes can remove them from the atmosphere, their 

concentrations increase, thus increasing the greenhouse effect. 

The heating effect caused by the human-induced buildup of GHGs 

in the atmosphere is very likely the cause of most of the 
26

observed global warming over the last 50 years. A detailed 

explanation of climate change and its impact on health, society, 

and the environment is included in EPA's technical support 

document (TSD) for the endangerment finding final rule (Docket 

ID No. EPA-HQ-OAR-2009-0472-11292). 

In the United States, the combustion of fossil fuels (e.g., 

coal, oil, gas) is the largest source of CO2 emissions and 

accounts for 80 percent of the total GHG emissions. More than 

half of the energy related emissions come from large stationary 

sources such as power plants, while about a third comes from 

transportation. Of the six well-mixed GHGs, four (CO2, CH4, N2O, 

and HFCs) are emitted by motor vehicles. In the United States 

industrial processes (such as the production of cement, steel, 

and aluminum), agriculture, forestry, other land use, and waste 

management are also important sources of GHGs. 

Different GHGs have different heat-trapping capacities. 

The concept of GWP was developed to compare the heat-trapping 

capacity and atmospheric lifetime of one GHG to another. The 

definition of a GWP for a particular GHG is the ratio of heat 

trapped by one unit mass of the GHG to that of one unit mass of 

CO2 over a specified time period. When quantities of the 

different GHGs are multiplied by their GWPs, the different GHGs 

can be summed and compared on a CO2e basis. For example, CH4 has 

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27

a GWP of 21, meaning each ton of CH4 emissions would have 21 

times as much impact on global warming over a 100-year time 

horizon as 1 ton of CO2 emissions. Thus, on the basis of heattrapping capability, 1 ton of CH4 would equal 21 tons of CO2e. 

The GWPs of the non CO2 GHGs range from 21 (for CH4) up to 23,900 

(for SF6). Aggregating all GHGs on a CO2e basis at the source 

level allows a facility to evaluate its total GHG emissions 

contribution based on a single metric. 

B. Endangerment Finding and the Light-Duty Vehicle Rule

1. Endangerment Finding 

On April 2, 2007, the United States Supreme Court found 

that GHGs are air pollutants under CAA section 302(g). 

Massachusetts v. EPA, 549 U.S. 497 (2007). As a result, the 

Supreme Court found that EPA was required to determine, under 

CAA section 202(a), whether (a) GHGs from new motor vehicles 

cause or contribute to air pollution which may reasonably be 

anticipated to endanger public health or welfare, or (b) the 

science is too uncertain to make a reasoned decision. After 

issuing a proposal and receiving comment, on December 7, 2009, 

the Administrator signed two distinct findings regarding GHGs 

under CAA section 202(a): 

• Endangerment Finding: The Administrator found that the 

current and projected atmospheric concentrations of the mix 

Formatted: Subscript
28

of six long-lived and directly emitted GHGs—CO2, CH4, N2O, 

HFCs, PFCs, and SF6 (referred to as “well-mixed greenhouse 

gases” in the endangerment finding)–are reasonably 

anticipated to endanger the public health and welfare of 

current and future generations. 

• Cause or Contribute Finding: The Administrator found that 

the emissions of the single air pollutant defined as the 

aggregate group of six well-mixed greenhouses gases from 

new motor vehicles and new motor vehicle engines contribute 

to the GHG air pollution that threatens public health and 

welfare. 

These findings, which were published December 15, 2009 (74 FR 

66496), do not themselves impose any requirements on industry or 

other entities. However, they were a prerequisite to finalizing 

the GHG standards for light-duty vehicles, described next. 

2. Light-Duty Vehicle Rule 

The light-duty vehicle rule, signed on April 1, 20104

 is a joint 

rule between EPA and the Department of Transportation’s National 

Highway Traffic Safety Administration (NHTSA) that establishes a 

national program consisting of new standards for light-duty 

 4

 This rule has not yet been published in the Federal 

Register. The signed version of the rule is available at

http://epa.gov/otaq/climate/regulations.htm. [update when 

published] 

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vehicles that will reduce greenhouse gas emissions and improve 

fuel economy. EPA finalized the national GHG emissions 

standards under the Act, and NHTSA finalized Corporate Average 

Fuel Economy (CAFE) standards under the Energy Policy and 

Conservation Act, as amended. The new standards apply to new 

passenger cars, light-duty trucks, and medium-duty passenger 

vehicles, starting with model year 2012. The EPA GHG standards 

are projected to result in an estimated combined average 

emissions level of 250 grams of CO2 per mile for model year 2016 

vehicles. The standards begin with the 2012 model year, with 

standards increasing in stringency through model year 2016. The 

standards are a fleet average for each manufacturer, based on a 

footprint attribute curve, meaning that the actual target for a 

vehicle will vary depending on the size of the vehicle. Under 

the footprint-based standards, each manufacturer will have a GHG 

standard unique to its fleet, depending on the footprints of the 

vehicle models produced by that manufacturer. A manufacturer 

will have separate footprint-based standards for cars and for 

trucks. 

 The endangerment and contribution findings described 

previously require EPA to issue standards under section 202 (a) 

“applicable to emission” of the air pollutant that EPA found 

causes or contributes to the air pollution that endangers public 

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30

health and welfare. The final emissions standards satisfy this 

requirement for GHGs from light-duty vehicles. Under section 

202(a) the Administrator has significant discretion in how to 

structure the standards that apply to the emission of the air 

pollutant at issue here, the aggregate group of six GHGs. EPA 

has the discretion under section 202(a) to adopt separate 

standards for each gas, a single composite standard covering 

various gases, or any combination of these. In the LDVR, EPA 

finalized separate standards for N2O and CH4, and a CO2 standard 

that provides for credits based on reductions of HFCs, as the 

appropriate way to issue standards applicable to emission of the 

single air pollutant, the aggregate group of six GHGs. EPA did 

not set any standards for PFCs or SF6, as they are not emitted by 

motor vehicles. 

C. What are the general requirements of the PSD program?

1. Overview of the PSD Program 

The PSD program is a preconstruction review and permitting 

program applicable to new major stationary sources and major 

modifications at existing major stationary sources. The PSD 

program applies in areas that are designated “attainment” or 

“unclassifiable” for a National Ambient Air Quality Standard 

(NAAQS). The PSD program is contained in part C of title I of 

the CAA. The "nonattainment new source review (NSR)" program 

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31

applies in areas not in attainment for a NAAQS or in the Ozone 

Transport Region and is implemented under the requirements of 

part D of title I of the CAA. Collectively, we commonly refer 

to these two programs as the major NSR program. The governing 

EPA rules are contained in 40 CFR 51.165, 51.166, 52.21, 52.24, 

and part 51, appendices S and W. There is no NAAQS for CO2 or 

any of the other well-mixed GHGs, nor has EPA proposed any such 

NAAQS; therefore, unless and until we take further such action, 

we do not anticipate that the "nonattainment" major NSR program 

will apply to GHGs. 

The applicability of PSD to a particular source must be 

determined in advance of construction or modification and is 

pollutant-specific. The primary criterion in determining PSD 

applicability for a proposed source is whether the source is a 

“major emitting facility,”, based on its predicted potential 

emissions of regulated pollutants, within the meaning of CAA 

section 169(1) and either constructs or undertakes a 

modification. EPA has implemented these requirements in its 

regulations, which use somewhat different terminology for 

determining PSD applicability, which is whether the source is a 

“major stationary source” or whether the proposed project is a 

“major modification.” 

a. Major Stationary Source 
32

Under PSD, a "major stationary source" is any source 

belonging to a specified list of 28 source categories which 

emits or has a potential to emit (PTE) of 100 tpy or more of any 

pollutant subject to regulation under the CAA, or any other 

source type which emits or has the PTE such pollutants in 

amounts equal to or greater than 250 tpy. We refer to these 

levels as the 100/250-tpy thresholds. A new source with a PTE 

at or above the applicable “major stationary source threshold" 

is subject to major source NSR. These limits originate from 

section 169 of the CAA, which applies PSD to any “major emitting 

facility” and defines the term to include any source that emits 

or has a PTE of 100 or 250 tpy, depending on the source 

category. Note that the major source definition incorporates 

the phrase “subject to regulation,” which, as described later, 

will begin to include GHGs on January 2, 2011, under our 

interpretation of that phrase discussed in the recent 

Interpretive Memo notice. 75 FR 17004. 

b. Major Modifications 

PSD also applies to existing sources that undertake a 

"major modification," which occurs: (1) when there is a 

physical change in, or change in the method of operation of, a 

"major stationary source;" (2) the change results in a 

"significant" emission increase of a pollutant subject to 
33

regulation (equal to or above the significance level that EPA 

has set for the pollutant in 40 CFR 52.21(b)(23)); and (3) there 

is a “significant net emissions increase” of a pollutant subject 

to regulation that is equal to or above the significance level 

(defined in 40 CFR 52.21(b)(23)). Significance levels, which 

EPA has promulgated for criteria pollutants and certain other 

pollutants, represent a de minimis contribution to air quality 

problems. When EPA has not set a significance level for a 

regulated NSR pollutant, PSD applies to an increase of the 

pollutant in any amount (that is, in effect, the significance 

level is treated as zero). 

2. General Requirements for PSD 

This section provides a very brief summary of the main 

requirements of the PSD program. One principal requirement is 

that a new major source or major modification must apply BACT, 

which is determined on a case-by-case basis taking into account, 

among other factors, the cost effectiveness of the control and 

energy and environmental impacts. EPA has developed a “topdown” approach for BACT review, which involves a decision 

process that includes identification of all available control 

technologies, elimination of technically infeasible options, 

ranking of remaining options by control and cost effectiveness, 

and then selection of BACT. Under PSD, once a source is 
34

determined to be major for any regulated NSR pollutant, a BACT 

review is performed for each attainment pollutant that exceeds 

its PSD significance level as part of new construction or for 

modification projects at the source, where there is a 

significant increase and a significant net emissions increase of 

such pollutant5

. 

In addition to performing BACT, the source must analyze 

impacts on ambient air quality to assure that no violation of 

any NAAQS or PSD increments will result, and must analyze 

impacts on soil, vegetation, and visibility. In addition, 

sources or modifications that would impact Class I areas (e.g., 

national parks) may be subject to additional requirements to 

protect air quality related values (AQRVs) that have been 

identified for such areas. Under PSD, if a source’s proposed 

project may impact a Class I area, the Federal Land Manager is 

notified and is responsible for evaluating a source’s projected 

impact on the AQRV’s and recommending either approval or 

disapproval of the source’s permit application based on 

anticipated impacts. There are currently no NAAQS or PSD 

 5

 We note that the PSD program has historically operated in 

this fashion for all pollutants – when new sources or 

modifications are “major”, PSD applies to all pollutants that 

are emitted in significant quantities from the source or 

project. This rule does not alter that for sources or 

modifications that are major due to their GHG emissions. 

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increments established for GHGs, and therefore these PSD 

requirements would not apply for GHGs, even when PSD is 

triggered for GHGs. However, if PSD is triggered for a GHG 

emissions source, all regulated NSR pollutants which the new 

source emits in significant amounts would be subject to PSD 

requirements. Therefore, if a facility triggers review for 

regulated NSR pollutants that are non-GHG pollutants for which 

there are established NAAQS or increments, the air quality, 

additional impacts, and Class I requirements would apply to 

those pollutants. 

The permitting authority must provide notice of its 

preliminary decision on a source's application for a PSD permit, 

and must provide an opportunity for comment by the public, 

industry, and other interested persons. After considering and 

responding to comments, the permitting authority must issue a 

final determination on the construction permit. Usually NSR 

permits are issued by state or local air pollution control 

agencies, which have their own permit programs approved by EPA 

in their SIP. In some cases, EPA has delegated its authority to 

issue PSD permits to the state or local agency. In other areas, 

EPA issues the permits under its own authority. 

D. What are the general requirements of the title V operating 

permits program?

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Deleted: Operating Permits 

Program
36

1. Overview of Title V 

The operating permit requirements under title V are 

intended to improve sources' compliance with other CAA 

requirements. The title V program is implemented through 

regulations promulgated by EPA, 40 CFR part 70, for programs 

implemented by state and local agencies and tribes, and 40 CFR 

part 71, for programs generally implemented by EPA. 

In summary, the title V program requires major sources 

(defined and interpreted by EPA to include sources that emit or 

have PTE of 100 tpy of any pollutant subject to regulation) and 

certain other sources to apply for operating permits. Under 

EPA’s long-standing interpretation, a pollutant, such as a GHG, 

is “subject to regulation” when it is subject to a CAA 

requirement establishing actual control of emissions. Title V 

generally does not add new pollution control requirements, but 

it does require that each permit contain all pollution control 

requirements or “applicable requirements” required by the CAA 

(e.g., New Source Performance Standard (NSPS), and State 

Implementation Plan (SIP) requirements, including PSD), and it 

requires that certain procedural requirements be followed, 

especially with respect to compliance with these requirements. 

"Applicable requirements" for title V purposes include 

stationary source requirements, but do not include mobile source 

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37

requirements. Other procedural requirements include providing 

review of permits by EPA, states, and the public, and requiring 

permit holders to track, report, and annually certify their 

compliance status with respect to their permit requirements. 

2. Title V Permit Requirements 

This section provides a brief summary of the requirements 

of the title V program that are most relevant to this action. A 

source generally must apply for a title V permit within 1 year 

of first becoming subject to permitting – for new sources, this 

is usually within 1 year of commencing operation. The 

application must include, among other things, identifying 

information, a description of emissions and other information 

necessary to determine applicability of requirements and 

information concerning compliance with those requirements. The 

permitting authority uses this information to develop the 

source's operating permit. 

Title V permits generally contain the following elements: 

(1) emissions limitations and standards to assure compliance 

with all applicable requirements; (2) monitoring, recordkeeping, 

and reporting requirements, including submittal of a semiannual 

monitoring report and prompt reporting of deviations from permit 

terms; (3) fee payment; and (4) an annual certification of 
38

certification by a responsible official. The detailed 

requirements are set forth at 40 CFR 70.6. 

In addition to the permit content requirements, there are 

procedural requirements that must be followed in issuing title V 

permits, including (1) application completeness determination; 

(2) public notice and a 30-day public comment period, including 

an opportunity for a public hearing, on draft permits; (3) EPA 

and affected state review; and (4) a statement of the legal and 

factual basis of the draft permit. The permitting authority 

must take final action (issue or deny) on the permit 

applications within 18 months of receipt. EPA also has 45 days 

from receipt of a proposed permit to object to its issuance, and 

citizens have 60 days after that to petition EPA to object to a 

permit. Permits may also need to be revised or reopened if new 

requirements come into effect during the permit terms or if the 

source makes changes that conflict with, or necessitate changes 

to, the current permit. Permit revisions and re-openings follow 

procedural requirements which vary depending on the nature of 

the necessary change to the permit. 

E. The Interpretive Memorandum 

 On December 18, 2008, EPA issued a memorandum, "EPA's 

Interpretation of Regulations that Determine Pollutants Covered 

by Federal Prevention of Significant Deterioration (PSD) Permit 
39

Program" (known as the “Johnson Memo” or the “PSD Interpretive 

Memo,” and referred to in this preamble as the “Interpretive 

Memo”) that set forth EPA’s interpretation regarding which EPA 

and state actions, with respect to a previously unregulated 

pollutant, cause that pollutant to become “subject to 

regulation” under the Act. Whether a pollutant is “subject to 

regulation” is important for the purposes of determining whether 

it is covered under the federal PSD and title V permitting 

programs. The Interpretive Memo established that a pollutant is 

“subject to regulation” only if it is subject to either a 

provision in the CAA or regulation adopted by EPA under the CAA 

that requires actual control of emissions of that pollutant 

(referred to as the “actual control interpretation”). On 

February 17, 2009, EPA granted a petition for reconsideration on 

the Interpretive Memo, and announced its intent to conduct a 

rulemaking to allow for public comment on the issues raised in 

the memorandum and on related issues. EPA also clarified that 

the Interpretive Memo would remain in effect pending 

reconsideration. 

On March 29, 2010, EPA signed a notice conveying its 

decision to continue applying (with one limited refinement) the 

Interpretive Memo’s interpretation of “subject to regulation” 

(“Interpretation of Regulations that Determine Pollutants 

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40

Covered by Clean Air Act Permitting Programs“). See 75 FR 

17004. EPA concluded that the “actual control interpretation” 

is the most appropriate interpretation to apply given the policy 

implications. However, we refined our interpretation in one 

respect: we established that PSD permitting requirements apply 

to a newly regulated pollutant at the time a regulatory 

requirement to control emissions of that pollutant “takes 

effect” (rather than upon promulgation or the legal effective 

date of the regulation containing such a requirement). In 

addition, based on the anticipated promulgation of the LDVR, we 

stated that the GHG requirements of the vehicle rule would take 

effect on January 2, 2011, because that is the earliest date 

that a 2012 model year vehicle may be introduced into commerce. 

In other words, the compliance obligation under the LDVR does 

not occur until a manufacturer may introduce into commerce 

vehicles that are required to comply with GHG standards, which 

will begin with model year 2012 and will not occur before 

January 2, 2011. We also reiterated EPA’s interpretation that 

the 100 tpy major source threshold for title V is triggered only 

by pollutants “subject to regulation” under the Act, and we 

defined and applied that term for title V purposes in the same 

way that we did for PSD purposes. That is, we stated that a 

pollutant is “subject to regulation” if it is subject to a CAA 
41

requirement establishing “actual control of emissions;” that a 

pollutant is considered “subject to regulation” for title V 

purposes when such a requirement “takes effect”; and, based on 

the anticipated promulgation of the LDVR, that the GHG 

requirements of the vehicle rule would take effect on January 2, 

2011. 

On April 1, 2010, we finalized the LDVR as anticipated, 

confirming that manufacturer certification can occur no earlier 

than January 2, 2011. Thus, under the terms of the final notice 

for the Interpretive Memo, GHGs become subject to regulation on 

that date, and PSD and title V program requirements will also 

begin to apply upon that date. 

IV. Summary of Final Actions 

This section describes the specific actions we are taking 

in this final rule. It describes the overall tailoring approach 

for NSR and title V applicability, the steps we are taking to 

put it into place, and future actions that we commit to take. 

The next section, V, provides the legal and policy rationale for 

these actions. In that section, we provide a description of our 

rationale and response to comments for each action, presented in 

the same order as we describe the actions later. 

A. How do you define the GHG pollutant for PSD and title V 

purposes?

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42

1. GHG Pollutant Defined as the Sum-of-Six Well-Mixed GHGs 

We are identifying the air pollutant for purposes of PSD 

and title V applicability to be the pollutant subject to 

regulation, which is the air pollutant for GHGs identified in 

EPA’s LDVR, as well as EPA’s endangerment and contribution 

findings6

. In the LDVR, EPA set emissions standards under 

section 202(a) that were “applicable to emission” of a single 

air pollutant defined as the aggregate sum of six greenhouse 

gases. The six GHGs, which are well-mixed gases in the 

atmosphere, are CO2, CH4, N2O, HFCs, PFCs, and SF6. Earlier, EPA 

made the contribution finding for this single air pollutant. 

Furthermore, as proposed, we are using an emissions 

threshold that allows all six constituent gases to be evaluated 

using a common metric – CO2e. Thus, to determine applicability, 

a source's GHG emissions are calculated on a CO2e basis by 

multiplying the mass emissions of any of the six GHGs that the 

source emits by that gas’s GWP and then summing the CO2e for each 

GHG emitted by the source. This sum, expressed in terms of tpy 

CO2e, is then compared to the applicable CO2e-based permitting 

threshold to determine whether the source is subject to PSD and 

title V requirements. 

 6 See 74 FR 66496, 66499, 66536-7. December 15, 2009. Formatted: Font: (Default) Courier

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In addition, because we are implementing this phase-in 

through the term “subject to regulation” the rule is structured 

such that the statutory mass-based thresholds (i.e. 100/250 tpy)7

and 0 tpy for modifications at a major stationary source apply 

and stationary sources or modifications that do not meet these 

thresholds are not subject to permitting requirements. While 

technically evaluation of the mass-based thresholds is the 

second step in the applicability analysis, from a practical 

standpoint most source are likely to treat this as an initial 

screen and not evaluate emissions on a CO2 e basis if they would 

not trigger PSD on a mass basis and we have treated it as such 

in our descriptions later. As applicable, a source would 

evaluate these mass-based thresholds by summing each of the six 

GHGs it emits on a mass basis (i.e., before applying GWP). We 

expect that it will be very rare for a new stationary source or 

modification to trigger permitting based on CO2e and not also 

trigger based on mass alone. 

 Determining permit program applicability for the GHG “air 

pollutant” by using the sum-of-six GHGs is based on EPA’s 

interpretation that the PSD and title V requirements apply to 

each “air pollutant” that is “subject to regulation” under 

 7

 A source need not meet the 100/250 thresholds for GHGs if 

it is already a major stationary source as a result of emissions 

of another regulated NSR pollutant. 

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44

another provision of the CAA. As discussed previously, the 

final LDVR for GHGs makes it clear that the emissions standards 

EPA adopted are standards applicable to emission of the single 

air pollutant defined as the aggregate mix of these six wellmixed greenhouse gases. See April 1, 2010 Preamble, II.A.2.c., 

pp 153-4., and 40 CFR 86.1818-12.8

 For reasons explained in more 

detail in section V, we have determined it is legally required, 

and preferable from a policy standpoint, for EPA to use the same 

definition of the air pollutant for permitting purposes as that 

used in the rule that establishes the control requirements for 

the pollutant. We also believe there are implementation 

advantages for applying PSD and title V in this way. Thus, this 

rule establishes that a stationary source will use the group of 

six constituent gases for permitting applicability, rather than 

treating each gas individually. Similarly, you will include all 

six constituent gases because that is how the air pollutant is 

defined, even though motor vehicles only emit four of the six. 

2. What GWP values should be used for calculating CO2e? 

 8 40 CFR 86.1818-12 (a) (“Applicability. This section 

contains standards and other regulations applicable to the 

emission of the air pollutant defined as the aggregate group of 

six greenhouse gases: carbon dioxide, nitrous oxide, methane, 

hydrofluorocarbons, perfluorocarbons, and sulfur hexafluoride”). 

Formatted: Indent: First line: 0.5"

Deleted: §

Deleted: §
45

We are requiring that wherever you perform an emissions 

calculations involving CO2e for the purposes of determining the 

applicability of PSD or title V requirements, you use the GWP 

values codified in the EPA’s GHG mandatory reporting rule 

[Reference: Table A-1 to Subpart A of Part 98 – Global Warming 

Potentials, FR, Vol.74, No. 209, p. 56395]. This approach will 

assure consistency between the values required for calculations 

under the mandatory reporting rule and for PSD or title V. In 

addition, because any changes to Table A-1 of the mandatory GHG 

reporting rule regulatory text must go through a rulemaking, 

this approach will assure that the values used for the 

permitting programs will reflect the latest values adopted for 

usage by EPA after notice and comment. 

B. When will PSD and title V applicability begin for GHGs and 

emission sources?

Overview 

 In this action, we establish the first two phases of our 

phase-in approach, which we refer to as steps 1 and 2. We also 

commit to a subsequent rulemaking in which we will propose or 

solicit comment on establishing a further phase-in, that is, a 

step 3, that would apply PSD and title V to additional sources, 

effective July 1, 2013, and on which we commit to take final 
46

action, as supported by the record,9

 by no later than July 1, 

2012. 

We also commit to undertaking an assessment of sources’ and 

permitting authorities’ progress in implementing PSD and title V 

for GHG sources, and to complete this assessment by 2015. We 

further commit to completing another round of rulemaking 

addressing smaller sources by April 30, 2016. Our action in 

that rulemaking would address permitting requirements for 

smaller sources, taking into account the remaining problems 

concerning costs to sources and burdens to permitting 

authorities. Finally, we determine in this action that we will 

apply PSD or title V requirements to sources that emit GHGs, or 

that conduct modifications that result in increases in emissions 

of GHGs, in amounts of less than 50,000 tpy CO2e any earlier than 

when we take the required further action to address smaller 

sources by April 30, 2016. 

Through this process, we will implement the phase-in 

approach by applying PSD and title V at threshold levels that 

are as close to the statutory levels as possible, and do so as 

 9

 Although we commit to propose or solicit comment on lower 

thresholds and to take final action on that proposal by July 1, 

2012, we cannot, at present, commit to promulgate lower 

thresholds. It will not be until the Step 3 rulemaking itself 

that we will gather and analyze data and receive comments that 

determine whether we have basis for promulgating lower 

thresholds. 

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47

quickly as possible, at least to a certain point. The level and 

timing of the thresholds that we promulgate in future actions 

will be based on our assessment of the resulting costs to 

sources and burdens to permitting authorities, and that, in 

turn, will depend on such variables as our progress in 

developing streamlining approaches and on permitting 

authorities’ progress in developing permitting expertise and 

acquiring more resources. At this time, we cannot foresee 

exactly when or in what manner those developments will occur. 

Therefore, we cannot promulgate more components of the tailoring 

approach beyond what we promulgate in this action. We can say 

only that we may continue the phase-in process with further 

rulemaking after 2016. Alternatively, we may make a definitive 

determination in one of the future rulemaking actions that, 

under the “absurd results” doctrine, PSD or title V applies only 

to certain GHG sources, and does not apply to the remaining GHG 

sources, and with that rulemaking, bring this tailoring process 

to a close. 

1. What are the Step 1 thresholds, timing, and calculation 

methodology? 

a. PSD Permitting 

Step 1 of the Tailoring Rule phase-in will begin on January 

2, 2011. With respect to the PSD program, GHG sources will 

Deleted: tailoring rule
48

become subject to PSD for their GHG emissions if they undergo 

PSD permitting anyway, either for new construction or for 

modification projects, based on emissions of non-GHG pollutants, 

in which case they will be subject to the PSD requirements for 

GHG if they increase GHG emissions by 75,000 tpy CO2e or more. 

Under this step, only these sources, which we refer to as 

“anyway” PSD sources, will become subject to PSD; no sources 

will become major sources for PSD purposes or be treated as 

undertaking modifications that trigger PSD based solely on their 

GHG emissions. As a result, no additional PSD permitting 

actions will be necessary solely due to GHG emissions. However, 

existing or newly-constructed sources that are determined to be 

major sources based on non-GHG emissions are required to conduct 

a BACT review for their GHG emissions (from new construction) or 

emissions increases (from modifications), if they are subject to 

PSD due to their non-GHG emissions from construction or 

modification actions and each of the following conditions is 

met: 

1) The GHG emissions (or net emissions increase) due to 

the new construction (or modification) project, calculated as 

the sum of the six well-mixed GHGs on a mass basis (no GWPs 

applied) exceed a value of 0 tpy; and 
49

2) The GHG emissions (or net emissions increase) due to 

the new construction (or modification) project, calculated as 

the sum of the six well-mixed GHGs on a CO2e basis (GWPs applied) 

equal or exceed a value of 75,000 tpy CO2e. 

The purpose of the first condition is to determine whether 

the GHG emissions or net emissions increase has resulted in an 

“increase in the amount” of an air pollutant as required by the 

Act. Because EPA has not defined a mass-based regulatory 

significance level for GHGs, that level, in effect, is treated 

as zero. See 40 CFR 52.21 (b)(23)(ii) and 51.166 (b)(23)(ii). 

In practice, this means any amount of new emissions or an 

emission increase will exceed the mass-based limit. We are not, 

at this time, establishing a significance level based on mass 

emissions because we have established one based on CO2e that 

addresses permitting burdens. Thus, the mass-based step will be 

used only to exclude sources that have no mass increase of GHGs. 

b. Title V Permitting 

Under step 1, only sources required to have title V permits 

for non-GHG pollutants (i.e., “anyway” title V sources) will be 

required to address GHGs as part of their title V permitting. 

That is, no sources will become major for title V based solely 

on their GHG emissions. Note further, however, that the 75,000 

tpy CO2e limit does not apply to title V, so that anyway title V 

Deleted: §§ 

Deleted: At this time, we are 

not establishing a 

significance level on a mass 

emissions basis.
50

sources must apply any title V requirements to their GHG 

emissions. Sources with title V permits must address GHG 

requirements when they apply for, renew, or revise their 

permits. These requirements will include any GHG applicable 

requirements (e.g., GHG BACT requirements from a PSD process) 

and associated monitoring, record-keeping and reporting. When a 

permit application is otherwise required, they will also need to 

identify GHG emissions and other information in that application 

to the extent required under 40 CFR 70.5(c) and 71.5(c), 

including information necessary to determine applicable 

requirements.10

2. What are the Step 2 thresholds, timing, and calculation 

methodology? 

a. PSD Permitting 

Step 2 will begin July 1, 2011. Under step 2, anyway PSD 

sources - that is, sources already subject to PSD based on nonGHGs and covered under step 1 previously - will remain subject 

to PSD. In addition, sources with the potential to emit 100,000 

tpy CO2e or more of GHG will be considered major sources for PSD 

 10 EPA notes, however, that many sources subject to title V 

under steps 1 and 2 will also be subject to the GHG mandatory 

reporting rule. For these sources, the emissions description 

requirements in the title V regulations will generally be 

satisfied by referencing information provided under the 

reporting rule. 

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Deleted: regardless of the 

amount of those emissions

Deleted: §§ 

Deleted: above

Deleted: 10
51

permitting purposes (provided that they also emit GHGs or some 

other regulated NSR pollutant above the 100/250 tpy (mass based) 

statutory thresholds. Additionally, any physical change or 

change in the method of operation at a major source (including 

one that is only major due to GHGs) resulting in a net GHG 

emissions increase of 75,000 tpy CO2e or more will be subject to 

PSD review and requirements with respect to GHGs (provided that 

it also results in an increase of GHG emissions on a mass 

basis). 

 Specifically, for purposes of determining whether a GHG 

emission source undertaking construction is considered a major 

source under PSD, the following conditions must be met: 

1) The GHG emissions at a newly constructed source which 

is not major for another pollutant, calculated as the sum-ofsix well-mixed GHGs on a mass basis (no GWPs applied): 

- equal or exceed 100 tpy (in actual emissions or 

potential to emit) for sources in any of the 28 major 

emitting facility source categories listed under PSD, or 

- equal or exceed 250 tpy (in actual emissions or 

potential to emit) for any other stationary source. 

2) The GHG emissions at a newly constructed source, 

calculated as the sum-of-six well-mixed GHGs on a mass basis 
52

(GWPs applied) equal or exceed 100,000 tpy CO2e (on an actual or 

potential to emit basis). 

For determining whether a modification project at a major 

stationary source is subject to PSD review, the following 

conditions must be met: 

1) The net GHG emissions increase resulting from the 

project, calculated as the sum of-six well-mixed GHGs on a mass 

basis (no GWPs applied) equals or exceeds 0 tpy. 

2) The net GHG emissions increase resulting from the 

project, calculated as the sum-of-six well-mixed GHGs on a CO2e 

basis (GWPs applied) equals or exceeds 75,000 tpy CO2e. 

The purpose of the first condition in both determinations 

previously is to confirm whether the GHG emissions or emissions 

increase have exceeded, on a mass-basis, the statutory major 

source thresholds (where the source is not otherwise major) and 

mass-based statutory significance level for GHGs, which, as 

noted previously, is 0 tpy. See 40 CFR 52.21 (b)(23)(ii) and 

51.166 (b)(23)(ii). 

As an example of how the mass-based test would apply, 

consider a modification project that results in a 5 tpy increase 

of GHG emissions on a mass basis, associated with a high-GWP GHG 

gas (for example, SF6, with a GWP value of 23,900), but also 

results in a 100 tpy reduction in CO2 emissions (assume no other 

Deleted: above

Deleted: above

Deleted: § 
53

contemporaneous increases or decreases of GHG). In this 

example, there would be a net decrease of GHG emissions on a 

mass basis (5 tpy – 100 tpy = -95 tpy). Because there is no 

mass-based increase of GHG, this project does not trigger PSD, 

despite the fact that the net GWP-adjusted emissions increase of 

SF6 in this example would equal 119,500 tpy of CO2e and the 

project would thus exceed 75,000 tpy CO2e. 

b. Title V Permitting 

Under step 2, “anyway” title V sources - that is, sources 

already subject to title V based on non-GHGs and that are 

covered under step 1 previously - will continue to be subject to 

title V. In addition, GHG emission sources that equal or exceed 

the 100,000 tpy CO2e threshold will be required to obtain a title 

V permit if they do not already have one. It is important to 

note that the requirement to obtain a title V permit will not, 

by itself, result in the triggering of additional substantive 

requirements for control of GHG. Rather, these new title V 

permits will simply incorporate whatever applicable CAA 

requirements, if any, apply to the source being permitted. The 

following conditions need to be met in order for title V to 

apply under step 2 to a GHG emission source. 

For determining whether a GHG emission source is subject to 

permitting under title V: 

Deleted: above
54

1) The GHG emissions at an existing or newly constructed 

source, calculated as the sum of the six well-mixed GHGs on a 

mass basis (no GWPs applied), equal or exceed 100 tpy (on an 

actual emission or PTE basis). 

2) The GHG emissions at an existing or newly constructed 

source, calculated as the sum of the six well-mixed GHGs on a 

mass basis (GWPs applied), equal or exceed a value of 100,000 

tpy CO2e (on an actual emission or PTE basis) 

3. What about Step 3? 

In this rule, EPA establishes an enforceable commitment to 

complete another rulemaking no later than July 1, 2012, in which 

we will propose or solicit comment on a step 3 of the phase-in 

and may also consider other approaches that may result in the 

permanent exclusion of a category of sources from PSD or title V 

requirements, under the Chevron framework, taking account of the 

“absurd results” doctrine. 

Consistent with our phase-in approach, it is important for 

us to consider whether, at some point during the implementation 

of step 2, it will become possible to administer GHG permitting 

programs for additional sources. For example, if EPA is able to 

promulgate measures that streamline programs to at least some 

extent, if permitting authorities increase their resources, or 

if implementation experience and more seasoned staff results in 
55

more effective use of scarce permitting resources, then we 

expect that we will be able to phase-in the application of PSD 

and title V to more sources by establishing step 3. We do not 

have enough information now to establish a final step 3, 

particularly because there will be significant transition 

occurring in the GHG permitting programs during steps 1 and 2. 

However, we believe that it will be possible to develop a record 

on which to base step 3 sometime soon after we begin to 

implement step 2. 

Therefore, we plan to propose a rule in which we solicit 

comment on or propose lower thresholds for PSD and title V 

applicability, and we establish an enforceable commitment to 

finalize a rule in which we address those matters by July 1, 

2012. In order to provide a year for permitting authorities and 

sources to prepare for any additional GHG permitting action in 

Step 3, we will establish that Step 3 would take effect on July 

1, 2013. We also commit to explore between now and the step 3 

proposal, a wide range of streamlining options. In the 

proposal, we will take comment on streamlining approaches we 

think may be viable (except to the extent we will have already 

issued guidance documents concerning streamlining approaches), 

and we will address those options in the final rule. 
56

In addition, as part of the step 3 action, we may solicit 

comment on a permanent exclusion of certain sources from PSD, 

title V or both, based on an “absurd results” rationale. For 

example, we may make a final determination that under the 

“absurd results” doctrine, PSD and/or title V do not apply to a 

set of GHG sources that, although above the statutory thresholds 

for those programs, are too small and relatively inconsequential 

in terms of GHG contribution. Another type of such exclusion 

for the title V program could be for sources that would 

otherwise be required to obtain an “empty permit,” that is, for 

example, one that would not contain any applicable requirements 

because there are none that apply to the source. It is possible 

that in promulgating a permanent exclusion, we may conclude that 

it brings into the PSD and title V programs the full set of 

sources that would be consistent with congressional intent, and, 

if so, we would find that such a rule brings the tailoring 

process to a close. The application of the “absurd results” 

rationale for a permanent exclusion is discussed in more detail 

in the next section. 

4. What about the proposed 6 year exclusion for smaller 

sources? 

The tailoring proposal contemplated at least a 6-year 

exclusion from permitting for small sources. This proposed 

Deleted: or any applicable 

GHG requirements, depending 

on the approach taken

Deleted: such an

Deleted: six
57

exclusion was based on the overwhelming numbers of permitting 

actions at small sources and the need for time for permitting 

authorities to secure resources, hire and train staff, and gain 

experience with GHG permitting for new types of sources and 

technologies. It was also based on the time needed for EPA to 

develop, and for states to adopt, streamlining measures to 

reduce the permitting burden (e.g., concerning PTE, presumptive 

BACT, or general permits). We therefore proposed such an 

exclusion, and proposed that it would last 6 years – 5 years to 

complete a required study evaluating permitting burden and 

assessing the effect of streamlining measures or techniques in 

reducing this burden, plus an additional year to complete a 

final rulemaking that would phase in additional sources as 

appropriate based on the study. 

 We are finalizing the 6-year exclusion, and for reasons 

described later, are establishing that in no event will sources 

below 50,000 tpy CO2e be subject to PSD or title V permitting 

during the 6-year period, nor will modifications be subject to 

PSD unless they increase emissions by 50,000 tpy CO2e or more. 

The exclusion will last until we take the action described later 

to address smaller sources, which is required by April 30, 2016. 

The exclusion provides certainty that, before this date, EPA 

will not act to cover sources and modifications below these 

Deleted: ,

Deleted: six

Deleted: below
58

thresholds, including during the required step 3 rulemaking that 

will occur in 2012. In effect, this means that step 3 will 

establish a major source threshold and significance level no 

lower than 50,000 tpy CO2e. This does not necessarily mean we 

will cover sources below this level on April 30, 2016. It 

simply means that the provision we are adopting would assure 

that EPA does not cover such sources any sooner than that. 

5. When and how will EPA take further action on smaller 

sources? 

As we proposed, we are establishing an enforceable 

commitment to act within 5 years to complete a study projecting 

the administrative burdens that remain for small sources after 

permitting authorities have had time to secure resources, hire 

and train staff, and gain experience with GHG permitting for new 

types of sources and technologies, and after EPA has had time to 

develop (and states have had time to adopt) streamlining 

measures to reduce the permitting burden for such sources. We 

will use this study to serve as the basis for an additional 

rulemaking that would take further action to address small 

sources. Similar to the enforceable commitment to act on step 

3, we are making an enforceable commitment to complete this 

rulemaking by April 30, 2016, 
59

We cannot predict at this time what form that final action 

will take. It could function as a step 4, bringing in 

additional sources based on, for example, streamlining actions, 

increased permitting authority resources, and experienced and 

more efficient permitting staff; and it could further indicate 

that we intend to follow-up with a step 5 to bring in more 

sources. Alternatively, it could also function as a final step 

excluding certain sources permanently based on our application 

of the Chevron framework, taking account of the “absurd results” 

doctrine, and subjecting the remaining sources to permitting. 

However, whatever final action we take would explain any 

necessary changes to the step 3 thresholds and would supersede 

the 6-year exclusion for sources and modifications below 50,000 

tpy CO2e. 

C. How do state, local and tribal area programs adopt the final 

GHG applicability thresholds?

We are finalizing our proposed approach to change the 

definition of “major stationary source” in the PSD implementing 

regulations, and the “major source” definition in the title V 

implementing regulations to tailor the application of these 

permitting programs to GHG emissions. We also finalize a 

significance level for GHG emissions for purposes of defining a 

major modification under the PSD program, and add an exclusion 
60

from PSD and title V permitting for GHG emissions, until we 

complete a rulemaking required by April 30, 2016, for any 

sources that are not already subject to PSD and title V 

permitting and that emit less than 50,000 tpy of CO2e. 

 As explained earlier, we are adopting thresholds that phase 

in the applicability of GHG permitting over a specified time 

period. In adopting regulatory changes to implement these 

thresholds, we follow an approach that is substantively the same 

as the approach proposed, but takes a different form. 

Specifically, we are explicitly codifying the phrase “subject to 

regulation” in our implementing regulations, instead of revising 

the “major stationary source” and “major source” definitions by 

incorporating the Tailoring Rules numerical thresholds directly 

into the definitions. Under this mechanism, we interpret the 

term “subject to regulation” so that GHG emissions from sources 

above the threshold are treated as subject to regulation, and 

therefore the sources that emit them are subject to PSD and 

title V; while GHG emissions from sources below the threshold 

are not treated as subject to regulation, and therefore the 

sources that emit them are not subject to PSD or title V. We 

are finalizing this alternative regulatory approach to 

facilitate rapid adoption and implementation of the final rules 

by states. These states would be able to establish their 

Deleted: slightly 

Deleted: tailoring rules
61

interpretation of “subject to regulation” by January 2, 2011, 

which is the date that the Tailoring Rule would take effect, and 

thereby, at that time, exempt sources below the threshold from 

PSD and title V as a matter of both federal and state law. We 

are also finalizing this definition consistent with our 

statements in our recent action “Reconsideration of 

Interpretation of Regulations that Determine Pollutants Covered 

by Clean Air Act Permitting Programs” (75 FR 17704) to better 

inform readers of our existing interpretation of this phrase as 

it applies to all air pollutants. States may not need to 

undertake a regulatory or legislative action before implementing 

the final rule. 

Because we finalize the rule in a manner that will allow 

most states to rapidly adopt and implement the final rule, and 

because our recent action on the Interpretive Memo allowed for a 

longer transition time than we anticipated at proposal, we are 

delaying final action on our proposal to issue limited approvals 

for SIP-approved PSD programs and part 70 operating permit 

programs.11 Instead, we are requesting that states submit 

information to the appropriate Regional Administrator by [INSERT 

DATE 60 DAYS AFTER PUBLICATION IN THE FEDERAL REGISTER] so that 

 11 In the alternative, we also proposed to use our 110(k)(6) 

error correction authority to revise SIP-approved PSD programs. 

Deleted: tailoring rule

Deleted: 
62

we may determine whether it is still necessary to finalize any 

of our proposed limited approvals for any SIP-approved PSD and 

part 70 title V state programs. In that letter, states should 

explain whether they will adopt EPA’s regulatory interpretation 

of the term “subject to regulation” in implementing both their 

PSD and part 70 title V permitting programs, and if so, whether 

the state intends to adopt the interpretation without 

undertaking a regulatory or legislative process. If a state 

must revise its statutes or regulations to implement the 

interpretation, we ask states to provide an estimate of the time 

to adopt final rules in its letter to the Regional 

Administrator. If a state chooses not to adopt our 

interpretation, the letter should address whether the state has 

alternative authority to implement the final rule’s tailoring 

approach or some other approach that is at least as stringent, 

but which also addresses the expected shortfalls in personnel 

and funding that would exist if the state carried out permitting 

at thresholds lower than those in the final rules. For any 

state that is unable or unwilling to adopt the permitting 

thresholds in the final rules, and otherwise is unable to 

demonstrate adequate personnel and funding, or alternate 

authority to permit GHG emissions sources consistent with the 

final rules, EPA will move forward with finalizing a limited 

Deleted: Part
63

approval of the state’s permitting program. By the same token, 

if we do not receive a letter from a state in response to this 

request by [date], we will be obliged to move forward with 

finalizing a narrowing of our approval of the existing SIP or 

title V program. 

We also ask any state that currently lacks authority to 

issue PSD or title V permits to any GHG emissions sources to 

notify the Regional Administrator by letter as to whether the 

state intends to undertake rulemaking to revise their rules 

consistent with these applicability thresholds. For any state 

that lacks the ability to issue PSD or title V permits for GHG 

emissions sources consistent with the final rule, we will 

undertake a separate action to call for revisions to these 

programs. We will also move quickly to impose a FIP for PSD 

through 40 CFR 52.21, and use our federal title V authority to 

ensure that GHG sources will be permitted consistent with the 

final rules. Our request for information from states is 

discussed further in section V.C. 

D. How do you treat GHGs for title V permit fees?

We are not amending the title V regulations for fees at 

this time, including any of the provisions specifying the 

presumptive minimum fee. We are also not, at this time, calling 

for each state, local or tribal program to submit new fee 

Deleted: section 
64

adequacy demonstrations as a result of increased GHG permitting 

workload during steps 1 and 2. However, as described in section 

VI.D the statutory and regulatory requirement to collect fees 

sufficient to cover all reasonable (direct and indirect) costs 

required to develop and administer title V programs still 

applies. Therefore we are recommending that each program review 

its resource needs for GHG-emitting sources and determine if the 

existing fee approaches will be adequate. If those approaches 

will not be adequate, we suggest that state, local and tribal 

agencies should be proactive in raising fees to cover the direct 

and indirect costs of the program or develop other alternative 

approaches to meet the shortfall. We will closely monitor 

approved title V programs during the first two steps of the 

Tailoring Rule to ensure that the added workload from 

incorporating GHGs into the permit program does not result in 

fee shortfalls that imperil operating permit program 

implementation and enforcement. In developing alternative 

approaches, we note the value of approaches that do not require 

a per-ton fee for GHG and therefore do not require a GHG 

inventory to develop. Finally we offer to work with permitting 

authorities that request our assistance with developing fee 

approaches.

E. Other Actions and Issues 

Deleted: ,
65

This section describes other actions we intend to take in 

the future related to GHG permitting in addition to the actions 

that we are promulgating with this final rule. This section 

also responds to commenters’ suggestions that we undertake 

additional actions in this rule, which we decline to do. 

1. Timing for Permit Streamlining Techniques 

As described at proposal, we intend to develop a series of 

streamlining approaches as an integral part of our phase-in 

approach. The approaches we described at proposal included: 

(1) defining PTE for various source categories, (2) establishing 

emission limits for various source categories that constitute 

presumptive BACT, (3) establishing procedures for use of general 

permits and permits-by-rule, (4) establishing procedures for 

electronic permitting, and (5) applying lean techniques to 

establish more efficient permitting processes. Taken as a 

whole, these techniques have the potential to obviate the 

applicability of PSD and title V requirements for some GHGemitting sources; promote more efficient treatment of GHGemitting sources that will already be subject to PSD and title 

V; and allow the expeditious expansion of PSD and title V 

applicability to more GHG-emitting sources while protecting 

those sources and the permitting authorities from undue 

expenses. 

Deleted: will 
66

As a result, we fully intend to move forward expeditiously 

with developing streamlining approaches. However, for reasons 

discussed in section V.E, we do not expect to develop and 

implement any of these approaches before step 2 begins. 

Moreover, we generally expect that each of the first three – 

which are the most far-reaching -- will take several years to 

implement because we will need to undertake notice and comment 

rulemaking to develop them, and then the permitting authorities 

will need to adopt them through the appropriate state or local 

processes. We commit to explore a wide range of possible 

approaches before the step 3 rulemaking, and, in that 

rulemaking, to propose those that we think may be viable once we 

have had time to gather and review key supporting data, and once 

the states and we have key implementation experience that can 

inform our thinking. Because the streamlining approaches 

generally carry uncertainty - as demonstrated by comments we 

received raising legal and policy concerns, as discussed later, 

that we will have to address - we are not committing with this 

action to adopt streamlining actions on any particular schedule. 

However, we intend to pursue streamlining options as 

expeditiously as possible, beginning immediately and proceeding 

throughout the phase-in period, and we encourage permitting 

authorities to do the same. 

Deleted: these

Deleted: I

Deleted: below

Deleted: all 
67

2. Guidance for Best Available Control Technology 

Determinations 

Through this final rule we are not amending our regulations 

or issuing guidance on BACT for GHGs. As described in our 

proposal, we recognize the need to develop and issue technical 

and policy guidance for permitting of GHGs, and we plan to 

accomplish it through a separate effort that will involve 

stakeholder input. This effort is already underway; in addition 

to comments EPA received on the proposed Tailoring Rule related 

to GHG BACT guidance and information needs, EPA received a suite 

of recommendations from the Clean Air Act Advisory Committee 

(CAAAC) to which EPA is actively responding. This includes 

technical guidance and database tools that EPA anticipates 

issuing by June 2010, and policy guidance that will be issued by 

the end of 2010. Thus, this important information will be 

available to support permitting agencies in their BACT 

determinations at the time that the GHGs become a regulated NSR 

pollutant, once the light-duty vehicle rule takes effect in 

January 2011. EPA is confident that these measures will help 

support a smooth transition to permitting emissions of GHGs. 

3. Requests for Higher Category-Specific Thresholds and 

Exemptions from Applicability 
68

 EPA has decided not to provide exemptions from 

applicability determinations (major source and major 

modification) under title V and PSD for certain GHG emission 

sources, emission activities, or types of emissions at this 

time. Commenters requested several applicability exemptions 

with respect to GHGs from, for example, agricultural sources, 

residential sources, small businesses, energy-intensive 

industrial processes (e.g., aluminum, steel, cement, glass, and 

pulp and paper manufacturers), lime production, semiconductor 

production, poultry production, solid waste landfills, biomass 

combustion/biogenic emissions, fugitive emissions, and pollution 

control projects. For reasons explained in section VI.E, we 

have decided to address the need for tailoring through a uniform 

threshold-based approach, rather than through a collection of 

various specific exclusions. 

4. Transitional Issues including Requests for Grandfathering 

For reasons explained in section V.E, EPA has determined 

that transitional issues for pending applications and permitted 

sources are adequately addressed by existing requirements and 

the amount of lead time provided before permitting requirements 

apply to GHGs under this rule and the April 2, 2010 final action 

regarding the Interpretive memo. This rule does not contain any 
69

additional exemptions or grandfathering provisions addressing 

the transition to PSD and title V permitting for GHGs. 

We are not promulgating an exemption for PSD permit 

applications that are pending when step 1 of the permitting 

phase-in begins for those sources that would otherwise need to 

obtain a PSD permit based on emissions of pollutants other than 

greenhouse gases. Any PSD permits issued to Phase 1 sources on 

or after January 2, 2010 will need to address GHGs. This action 

makes no change to the position we expressed on this issue on 

April 2, 2010. 

 Final PSD permits issued before January 2, 2011 need not be 

reopened or amended to incorporate requirements for GHGs that 

take effect after the permit is issued. A source that is 

authorized to construct under a PSD permit but has not yet begun 

actual construction on January 2, 2011 may begin actual 

construction after that date without having to amend the 

previously-issued PSD permit to incorporate GHG requirements, 

provided the permit has not expired. 

Sources that are not subject to PSD permitting requirements 

until Step 2 need not obtain a PSD permit addressing GHGs in 

order to continue any actual construction that begins before 

July 1, 2011, when such a source was not a major stationary 

source required to obtain a PSD permit. However, Phase 2 
70

sources that begin actual construction in phase 2 may do so only 

after obtaining a PSD permit. 

The title V permitting regulations already include a robust 

set of provisions to address the incorporation of new applicable 

requirements and other transitional considerations. A title V 

source applying for the first time must submit its permit 

application within 12 months after the source becomes subject to 

the operating permit program or an earlier time at the 

discretion of the permitting authority. Where a source is 

required to obtain a PSD permit, the source must apply for a 

title V permit or permit revision within 12 months of commencing 

operation or on or before such earlier date as the permitting 

authority may establish. Where additional applicable 

requirements become applicable to a source after it submits its 

permit application, but prior to release of a draft permit, the 

source is obligated to supplement its application. Permitting 

authorities may also ask for additional information during the 

processing of an application. In addition, where a source that 

already has a title V permit becomes subject to additional 

applicable requirements, the permitting authority is required to 

reopen the permit to add those applicable requirements if the 

permit term has 3 or more years remaining and the applicable 

Deleted: three
71

requirements will be in effect prior to the date the permit is 

due to expire. 

V. What is the legal and policy rationale for the final 

actions? 

In this section, we describe the legal and policy rationale 

for our action, including our rationale for the following: (A) 

our approach to calculating GHG emissions for PSD and title V 

applicability purposes, (B) our approach to establishing the 

thresholds and timing of PSD and title V applicability to GHG 

emissions sources; (C) how state, local, and tribal area 

programs adopt the final GHG applicability thresholds; (D) 

treatment of GHGs for title V permit fees; (E) future 

activities, including streamlining actions. We present the 

rationale description in five subsections later, corresponding 

to the basic presentation of the approach in section IV. 

A. Rationale for Our Approach to Calculating GHG Emissions for 

PSD and Title V Applicability Purposes

1. Grouping of GHGs into a Single Pollutant 

 In this section, we explain our treatment of the air 

pollutant at issue for purposes of PSD and title V, such that 

sources that emit that pollutant in the requisite quantities 

become subject to PSD and/or title V requirements. We explain 

our rationale for treating the GHG air pollutant as a combined 

Deleted: below
72

group of six greenhouse gases instead of six separate air 

pollutants defined by each individual greenhouse gas, and our 

rationale for including all six of the GHGs in that group. We 

also define the GHG metric to use for comparison to the 

applicability thresholds. 

 We proposed to identify the air pollutant as the aggregate 

group of the six GHGs that comprise the GHG pollutant, and to 

use a GHG metric for the applicability thresholds based on CO2e. 

The summed CO2e emissions would then be compared to the 

applicable permitting threshold to determine whether the source 

is subject to PSD and title V requirements. Historically, the 

PSD and title V regulatory provisions do not, in the first 

instance, define the “air pollutant” to which they apply, but 

rather rely for the definition of the pollutant on a crossreference to the regulatory provision under another part of the 

Act that establishes the emission standards or limits for that 

pollutant that in turn causes the pollutant to be subject to 

regulation under PSD and title V permitting. As an example, the 

pollutant ‘total reduced sulfur’ is a pollutant comprised of the 

sum of multiple compounds that was originally defined under the 

NSPS, Subpart BB, Standards of Performance for Kraft Pulp Mills, 

which then caused it to be subject to regulation under the PSD 

program. The actual compounds that define the pollutant TRS are 

Deleted: these 

Deleted: (TRS) 
73

identified in the NSPS. The PSD program regulations did not 

introduce its own independent definition of TRS, but instead 

relied on the definition as contained in the Kraft Pulp Mills 

NSPS. 

However, at the time of our proposal, the endangerment and 

cause or contribute findings had not been completed and the LDVR 

for GHGs had not been finalized. Thus, there was no final 

agency action defining the “air pollutant” consisting of GHGs to 

be considered “subject to regulation”. Absent a definition of 

“greenhouse gases” under another regulatory provision that we 

could cross-reference, we proposed to define “greenhouse gases” 

for permitting purposes as “the single air pollutant that is 

comprised of the group of six GHGs, as proposed in the [CAA] 

section 202(a) endangerment and contribution findings.” 74 FR

55,329, col. 1. The six well-mixed GHGs identified in the 

proposed contribution finding were: CO2, CH4, N2O, SF6, HFCs, and 

PFCs. 

 In the proposal, we further recognized that the LDVR for 

GHGs, as it was proposed, would result in reductions of only 

four of the gases, not all six, because only four are emitted by 

vehicles. However, we concluded that if the LDVR were finalized 

as proposed, then the air pollutant for purposes of PSD and 

Deleted: ,

Deleted: how 

Deleted: were 
74

title V applicability would be a single air pollutant that is 

the aggregate mix of the group of six GHGs because – 

[t]hese six GHGs as a class comprise the air pollutant 

that is the subject of the endangerment finding and 

companion contribution finding and constitute the air 

pollutant that is regulated by the light-duty vehicle 

rule through measures that address the components of 

that air pollutant that are emitted from the mobile 

sources. Thus, although the CAA section 202(a) 

proposal establishes controls only with respect to 

four GHGs, as a legal matter, the proposal covers the 

entire set of GHGs that as a class are the single “air 

pollutant” in the proposed endangerment and 

contribution findings. 

74 FR 55,329 col. 1. 

 We also solicited comment on whether we should identify 

the GHG metric in a different way, such as addressing each GHG 

constituent compound individually or including (whether 

individually or as a group) only those four GHG constituent 

compounds for which reductions would occur through the emission 

standards or limits proposed in the LDVR. 

A minority of the comments on our proposal addressed this 

issue. Some commenters supported combining the individual GHGs 

as one pollutant for purposes of determining permitting 

applicability, and stated that it is not uncommon for EPA to 

recognize ‘collective’ air pollutants comprised of many 

individual compounds based upon shared threats to health and 

welfare, including such EPA-created group pollutants as sulfur 

Deleted: 

Deleted: majority

Deleted: proposal 

Deleted: did not speak to or 

show a preference for or 

against grouping the six 

well-mixed GHGs for the 

purposes of determining 

applicability under the PSD 

and title V programs. Of 

those 

Deleted: that specifically 

support the

Deleted: of 

Deleted: they 
75

oxides, nitrogen oxides, volatile organic compounds (VOCs), and 

particulate matter (PM). 

On the other hand, a significant number of commenters also 

raised concerns that grouping the individual GHGs into one 

metric. Some of these commenters argued that grouping GHGs is 

not appropriate because GHGs are not like other air pollutants 

that are comprised of numerous substances of concern (e.g., VOCs 

and PM), individual GHGs do not interact or combine to create a 

pollutant of concern, and EPA has not established a ‘GHG’ NAAQS 

that supports the definition of the pollutant as a group. Some 

were concerned that regulating the GHGs as a group would 

increase the likelihood that a source will trigger permitting 

requirements, adding that this is unnecessary and would conflict 

with the “absurd results” and “administrative necessity” 

doctrines because it would lead to larger numbers of sources 

becoming subject to permitting. Some commenters opposing 

grouping suggested that we should explore regulating each of the 

GHG pollutants on an individual mass basis rather than 

collectively because in their view, it is reasonable and 

feasible to regulate and control emissions of each of the listed 

pollutants, other than carbon dioxide, at the 100/250 tpy 

thresholds, or less if deemed necessary, in accordance with the 

established mechanisms of the Act and doing so would lead to a 

Deleted: A smaller but 

Deleted: opposed the

Deleted: of 

Deleted: . One commenter 

added that, 
76

better environmental result. Finally, some commenters argued 

that disaggregating the pollutants would also allow for more 

appropriate technology review. 

 After considering these comments, and taking into account 

other related actions that have occurred since proposal, we have 

determined that PSD and title V permitting program requirements 

will apply, as proposed, to the “single air pollutant that is 

comprised of the group of six GHGs.” 74 FR 55,329, col. 1. We 

believe that this approach is both compelled by the statute and 

reflects the preferable policy approach. 

As more fully discussed elsewhere in this rulemaking, the 

PSD requirements apply to a “major emitting facility” that 

undertakes construction or “modification.” CAA section 165(a), 

169 (2)(C). The term “major emitting facility” is defined as, 

in general, a source that emits 100 or 250 tons of “any air 

pollutant,” CAA section 169(1), and, similarly, the term 

“modification” is defined as a physical or operational change 

that results in the increased or new emissions of “any air 

pollutant.” CAA section 169(2)(C), 111(a)(4) Through 

regulation, we have interpreted the term “any air pollutant,” as 

found in both the terms “major emitting facility” and 

“modification,” more narrowly to mean any “regulated NSR 

pollutant,” and we further define this term to include any 

Formatted: Indent: First line: 0.5"

Deleted: package, under the 

plain language of section 

169(1) PSD a 

Deleted: one 

Deleted: .” Through 

regulation we have 

reasonably limited the scope 

to this provision to those 

tonnages of 

Deleted: which includes 
77

pollutant that is “subject to regulation under the Act.” 40 CFR 

52.21(b)(50)(iv), 52.21.(b)(2).12 

Similarly, as discussed elsewhere, the title V requirements 

apply to a “major source,” which is defined, in general, as any

source that emits at least 100 tpy of “any air pollutant.” CAA 

§§ 502(a), 501(2)(B), 302(j). EPA has interpreted the term “any 

air pollutant” narrowly so that applies only with respect to air 

pollutants that are subject to regulation under the CAA. 

Memorandum from Lydia N. Wegman, Deputy Director, Office of Air 

Quality Planning and Standards, U.S. EPA, “Definition of 

Regulated Air Pollutant for Purposes of Title V” (Apr. 26, 

1993). 

Based on these provisions, the key issue for present 

purposes in determining whether a source is subject to PSD 

(because it qualifies as a major emitting facility that 

undertakes construction or modification) or title V is whether 

the pollutant or pollutants that the source emits comprise the 

“air pollutant” that is “subject to regulation” under the Act. 

The phrase “subject to regulation under the Act” by its 

terms, identifies the air pollutant that is subject to PSD and 

 12 By the same token, CAA section 165(a)(4) requires that a 

source subject to PSD impose best available control technology 

for “each pollutant subject to regulation under this chapter” 

that the source emits. 

Deleted: ). This same 

limitation exists in the 

definition of major 

modification and BACT. See

Deleted: ),( ). This 

regulatory limitation 

reflects the statutory 

directive that BACT is 

required for “each pollutant 

subject to regulation under 

this chapter.” 42 USC 7475 

(a)(4).

Deleted: Based on these 

provisions, the sole 

question in determining what 

a BACT analysis must cover 

is what pollutant is 

“subject to regulation.” 

This phrase caries with it 

no suggestion that the 

Agency may subdivide or 

otherwise change a pollutant 

that is regulated elsewhere 

in the Act. Instead, it 

carries with it a dictate 

that BACT be applied to the 

air pollutant which the 

Administrator has determined 

elsewhere to regulate. As 

described below, this air 

pollutant, in the cases of 

GHGs, is the aggregate mix 

of the six constituent gases 

identified in the 

contribution finding, which 

led to the promulgation of 

the LDVR, and is the air 

pollutant that the various 

LDVR emission standards 

address. This same logic 

regarding the definition of 

a pollutant “subject to 

regulation” applies to the 

determination of whether a 

source is a major stationary 

source of a “regulated NSR 

pollutant.” Thus, we also 

read the definition of major 

emitting facility at CAA 169 

to be guided by the same 

requirement to defines the 

“regulated NSR pollutant” 

that is “otherwise subject 

to regulation” to be the 

same air pollutant that is 

actually regulated elsewhere 

under the Act. If, as here, 

that regulation considers 

the aggregate emissions of 

several compounds to be a 

single air pollutant, the 

same single air pollutant is 

a regulated NSR pollutant. 

As noted above, the 

statutory definition of 

major emitting facility ... [2]
78

title V as the same air pollutant that is identified in the 

regulatory action under another provision of the Act. The term 

is a simple cross-reference. It carries no implication that EPA

may, in identifying the pollutant to which PSD or title V apply, 

may redefine the pollutant that is regulated elsewhere in the 

Act. Whatever the pollutant is that is regulated elsewhere, it 

is that pollutant to which PSD and title V apply. 

Since the time of our proposal, we have finalized both the 

contribution finding and the LDVR for GHGs. The final LDVR for 

GHGs specifies, in the rule’s applicability provisions, the air 

pollutant subject to control as the aggregate group of the six 

GHGs, including CO2, CH4, N2O, SF6, HFCs, and PFCs.13 Because it 

is this pollutant that is regulated under the LDVR, it is this 

pollutant to which PSD and title V apply. Specifically, the 

applicability provision in the LDVR provides a clear reference 

to the definition of the single pollutant comprised of the 

aggregate group of the six well-mixed GHGs, which makes clear

 13 The applicability provision of the LDVR is found in 40 CFR

§86.1818-12(a), which provides as follows:

Greenhouse gas emission standards for light-duty vehicles, 

light-duty trucks, and medium-duty passenger vehicles. 

Applicability. This section contains standards and other 

regulations applicable to the emission of the air pollutant 

defined as the aggregate group of six greenhouse gases: 

carbon dioxide, nitrous oxide, methane, hydrofluorocarbons, 

perfluorocarbons, and sulfur hexafluoride..

Formatted: Indent: Left: 0.5", First

line: 0"

Deleted: The 

Deleted: now 

Deleted: us 

Deleted: and affirms that

Deleted: See

Deleted: ) 

Deleted: (“

Deleted: .”).
79

PSD and title V applicability depends on he same sum-of-six GHG 

construct. We must follow this construct of the aggregate group 

of the six gases and do not have discretion to interpret the GHG 

‘air pollutant’ differently for the purposes of PSD or title V. 

This construct of the pollutant as the aggregate group of 

the six gases is also consistent with the definition of the air 

pollutant in the final contribution finding for GHGs [see 74 FR 

66496, 66499, 66536-7 (December 15, 2009)]. There, the 

Administrator defined the air pollutant as the “aggregate group 

of the same six... greenhouse gases,” 74 FR 66536), and these the 

well-mixed greenhouse gases are defined to include CO2, CH4, N2O, 

SF6, HFCs, and PFCs. 

Moreover, even if we had discretion to identify the GHGs 

air pollutant differently in the permitting programs than in the 

LDVR, we believe it is reasonable to identify the GHGs air 

pollutant through the sum-of-six construct for the same reasons 

why we adopted that definition in the contribution finding and 

for additional reasons noted below specific to the permit 

programs. The term “air pollutant” is defined under CAA section 

302(g) as “any air pollution agent or combination of such 

agents, including any physical, chemical, biological, 

radioactive ... substance or matter which is emitted into or 

otherwise enters the ambient air.” Under this definition, EPA 

Deleted: should use 

Deleted: 6 

Deleted: for applicability. 

Based upon the previous 

analysis, we 

Deleted: permitting

Deleted: In the final 

contribution finding

Deleted: for contribution 

finding 

Deleted: ” (see specifically,

Deleted: ). The 

Deleted: under the final 

contribution finding as 

these six greenhouse gases: 

Deleted: Again, these six 

GHGs as a class comprise the 

air pollutant that is the 

subject of the contribution 

finding and therefore are 

the single air pollutant 

that is regulated by the 

LDVR through measures that 

address the components of 

that air pollutant that are 

emitted from the mobile 

sources. For these reasons, 

the pollutant “subject to 

regulation” is the aggregate 

group of the six and we feel 

compelled to use this 

combined pollutant for 

purposes of regulation under 

the PSD program. 

Deleted: Similarly, for title 

V, "major stationary source" 

status under CAA sections 

501(2)(B) and 302(j) is 

triggered by the emissions 

of the requisite amount of 

"any air pollutant . . . . 

." Further, as discussed in 

more detail elsewhere in 

Deleted: approach

Deleted: , we would choose 

not to, for the same reasons 

we adopted the single air 

Deleted: ,

Deleted: considerations 

Deleted: Congress provided 

EPA broad discretion to 

determine, as an initial 

Deleted: air pollutant 

Deleted: that should be 

treated

... [4]

... [5]

... [3]
80

has broad discretion to identify an air pollutant, including, as 

appropriate, treating a combination of air pollutant agents as a 

single air pollutant. Here, we think that the six well-mixed 

gases are appropriately combined into a single air pollutant 

because, as noted in the contribution findings, they share 

several important attributes: Each of the six gases -- 

• Is directly emitted (and is not formed by secondary 

processes in the atmosphere) 

• Is long-lived in the atmosphere after it is emitted 

• Is sufficiently long-lived the greenhouse gas that it 

becomes “well-mixed,” which means that its concentration is 

essentially uniform in the atmosphere (as opposed to having 

significant local/regional variation); and 

• Has well understood atmospheric properties (e.g., 

radioactive forcing).

See 74 FR 66516-66518.

In addition, treating the six greenhouse gases as a single 

air pollutant is consistent with the actions of international 

scientific bodies. For example, the Intergovernmental Panel on 

Climate Change (IPCC) considers in various reports how the six 

gases drive human-induced climate change and how that affects 

health, society, and the environment. Similarly, the United 

Nations Framework Convention on Climate Change (UNFCCC) requires 

Formatted: Underline

Deleted: As 

Deleted: the 

Deleted: common 

Deleted: shared by

Deleted: greenhouse 

Deleted: are that each (see

74 FR 66516-66518):

Deleted: they are 

Deleted: radiative

Deleted: grouping

Deleted: gases

Deleted: focus of climate 

science—their effects are 

considered as a group in

Deleted: (i.e., the IPCC 

reports assess the climate 

change effects on health, 

society, and the environment 

as a result of

Deleted: driven by the group 

of GHGs). It is also 

consistent with the focus of 

climate policy—the 
81

reporting of these six gases and the commitments under the 

UNFCCC and Kyoto Protocol are based on the combined emissions of 

these six gases. Finally, as discussed later, it is standard 

practice to compute the “carbon dioxide (CO2) equivalency” of 

aggregate emissions using GWP. 

We disagree with commenters who argued that grouping all 

six GHGs is not appropriate because GHGs are not like other air 

pollutants that are comprised of numerous substances of concern 

(e.g., VOCs and PM). First, as noted previously, we are 

following the approach to a single air pollutant comprised of 

the aggregate of the six greenhouse gases initially adopted in 

the contribution finding and followed in the LDVR. Many of 

these same comments have already been addressed in the 

contribution finding and response to comments document, which is 

included in the Response to Comments (RTC) for this action, and 

those responses apply equally here. 

In addition to the reasons described in the endangerment 

and contribution findings, there are CAA permitting programmatic 

and policy advantages to using the sum-of-six construct for the 

GHG air pollutant for PSD and title V applicability purposes. 

We believe now, as we did at proposal, that the benefits in 

using the cumulative group of GHGs outweigh any implementation 

advantages to using an individual-GHG-based metric. The

Formatted: Indent: First line: 0.5"

Formatted: Underline

Deleted: ; 

Deleted: s. All of these 

common attributes and 

factors are relevant to the 

air pollution for which GHGs 

are agents—in other words, 

they are all related to 

increased atmospheric 

concentrations of the mix of 

six GHGs and climate change 

science and policy. Thus, 

they are a reasonable basis 

upon which to decide that it 

is appropriate to define the 

air pollutant as the 

combination of these six 

GHGs that share these 

attributes.

Deleted: above

Deleted: permitting

Deleted: We recognize a 

number of
82

advantages to sum-of-six definition include that it may -- (1) 

allow significantly more flexibility to sources for designing 

and implementing control strategies that maximize reductions 

across multiple GHGs and would also likely align better with 

possible future regulations that allow for such flexibility; (2) 

more effectively support possible future offsets or trading 

mechanisms that involve different source categories and 

different compositions of GHG emissions; and (3) could better 

accommodate and harmonize with future regulations because it 

establishes one class of pollutants that includes individual

components that may, in turn, become subject to specific 

emission standards under future regulatory efforts. 

We disagree with commenters who believe that aggregating 

the GHGs under one GHG metric for permitting applicability 

purposes would lead to an excessive amount of source permitting 

activity. This is because the phase-in approach addresses 

overwhelming permitting burdens associated with permitting of 

greenhouse gases. It does so by designing our applicability 

thresholds to allow for a manageable amount of new permitting 

actions based on the emissions from sources using the sum-of-six

metric. If we based applicability on individual gases, 

(assuming, again, that we have authority to deviate from the 

definition of “air pollutant” as used in the LDVR), we would 

Deleted: in the use of 

aggregate construction of 

the GHG metric, including 

that it: 

Deleted: could 

Deleted: could 

Deleted: by having one 

pollutant class 

Deleted: includes any of the 

components of which may 

Deleted: by 

Deleted: 6 

Deleted: it

Deleted: were not compelled 

to follow the 
83

still need to determine what level of permitting is manageable 

and appropriate based on thresholds on an individual gas basis 

and would expect that the final rule would result in the same 

levels of remaining burden. Accordingly, unless the permitting 

program were being implemented at the statutory thresholds, the 

effect of a decision to aggregate or not aggregate would not 

reduce workload; it would simply shift work from permitting 

facilities that trigger based on combined GHGs to those that 

trigger based on individual GHGs. Although we acknowledge that 

this may affect applicability for a particular source, we 

disagree with the commenter that doing so would conflict with 

our conclusions based on the “absurd results” or “administrative 

necessity” doctrines. By using a consolidated and weighted 

measurement, we are able to direct the limited administrative 

resources to those new sources and modifications with the 

greatest impact on GHG emissions. 

We also believe that the additional flexibility resulting 

from the sum-of-six GHG metric will provide substantially more 

opportunities for sources to address emission increases of GHGs 

than they would have had under an individual gas based metric, 

and thereby possibly reduce their permitting burden through 

multi-gas mitigation strategies. We disagree with the comment 

that isolating BACT review on sources that emit a single GHG 

Deleted: based on the 

administrative necessity and 

the absurd results concepts

Deleted: would

Deleted: In light of limited 

resources, by

Deleted: se

Deleted: reducing

Deleted: control technology

Deleted: GHG
84

necessarily leads to better environmental results than it would 

for sources that undergo a combined review for all six gases. 

To the contrary, given that Congress built in considerations of 

energy, environmental, and economic impacts into the BACT 

requirement, we think that allowing consideration of those 

factors across six gases will likely result in decisions that 

more appropriately account for those impacts at the source. 

2. Identifying Which GHGs are Included in the Group 

As discussed previously, we proposed to include the 

combination of six well-mixed GHGs as the air pollutant that 

triggers PSD and title V applicability: CO2, CH4, N2O, SF6, HFCs, 

and PFCs. Some commenters supported including all six. They 

cite the proposed contribution findings that identify the 

pollutant through the sum-of-six construct, and they emphasize 

that EPA, in order to protect the public, has to control all the 

greenhouse gases it has regulated and reduce the overall impact 

of the mix of six greenhouse gases. 

However, a substantial number of commenters, mainly from 

industry sectors who also disagree with grouping the GHGs 

together, contend that only the constituent gases that are 

actually subject to controls under the LDVR should be included 

in determining applicability under the Tailoring Rule. Some of 

these commenters believe that only the three compounds (CO2, CH4, 

Deleted: Most commenters did 

not raise any issues or 

propose alternatives to the 

use of the 

Deleted: GHG metric as it 

relates to inclusion of all 

Deleted: . We did receive 

some comments 

Deleted: explicitly supported 

the inclusion of all six of 

the well-mixed GHGs 

identified in the GHG metric 

for determining

Deleted: . Those in support 

of 

Deleted: of the well-mixed 

GHGs in the threshold metric 

Deleted: same reasons they 

provided in support of 

grouping the individual GHGs 

together: namely, the final 

Deleted: as “the combined mix 

of six key, directly 

emitted, long-lived and 

well-mixed greenhouse 

gases”. See 74 FR, 66496, 

66516, 66,536 (Dec. 15, 

1990). They also 

Deleted: d
85

N2O) for which the LDVR contains emissions standards or caps 

should be considered in the GHG metric for permitting, while 

others would also add HFCs (which are included in a credit 

flexibility arrangement under the LDVR) for a total of four 

GHGs. These commenters argued that PSD is not triggered for all 

six GHGs by the LDVR because under the proposed PSD 

interpretation in “EPA’s Interpretation of Regulations that 

Determine Pollutants Covered by Federal Prevention of 

Significant Deterioration (PSD) Permit Program”, actual emission 

controls under the Act are required to trigger PSD obligations 

for a given pollutant. They also argue that including all six 

would conflict with EPA’s rationale for the tailoring rule by 

leading to larger numbers of sources subject to permitting, 

thereby increasing the harm that EPA says it wants to avoid. 

They further assert that the EPA cannot exercise its discretion 

to widen the scope of PSD and title V applicability to six GHGs 

when it is relying on the judicial doctrines of “absurd results” 

and “administrative necessity” to narrow PSD and title V 

applicability. They explain that in their view, those doctrines

apply only when EPA has taken all steps possible to narrow the 

scope of PSD and title V and thereby avoid the administrative 

problems that force it to rely on those doctrines.

There were a few comments on whether to include specific 

Deleted: Such

Deleted: d

Deleted: the “absurd results” 

and “administrative 

necessity” doctrines because 

it would lead

Deleted: , and

Deleted: ed

Deleted: both 

Deleted: the

Deleted: at its discretion 

and rely on these 

Deleted: , which

Deleted: where the

Deleted: availed itself of 

all reasonable discretion to 

minimize the harm
86

gases as part of the sum-of-six grouping. Several commenters 

representing sectors that have significant SF6 usage specifically 

argue that SF6 should not be included as a GHG, at least at this 

time, because there are no known SF6 controls, it is not clear 

how PTE would be calculated from such facilities, and EPA has 

not addressed the economic burden that regulation of these 

facilities would create. A solid waste industry commenter 

asserts that the Tailoring Rule should confirm that CH4 and N2O 

will not be regulated under PSD or title V because these 

pollutants are only emitted in miniscule amounts from 

automobiles. 

 We disagree with commenters who suggest that because the 

LDVR actually regulates only four of the six GHGs, EPA may apply 

PSD and title V to only those four GHGs. It is true that the 

LDVR standard for the single air pollutant that is comprised of 

the aggregate of six GHGs consists of individual standards for 

only four particular constituents of the single air pollutant –

which are emissions limits or caps for three GHGs (CO2, CH4, and 

N2O) and an emission crediting option for one GHG (HFCs) – but 

this does not dictate that only those four compounds are subject 

to regulation for permitting purposes. Although the LDVR 

results in reductions only with respect to four specific GHGs, 

as a legal matter the LDVR standard covers the entire set of 

Deleted: for GHGs constrains 

EPA’s authority to regulate

Deleted: the 

Deleted: individual 

Deleted: emitted by motor 

vehicles. The fact

Deleted: greenhouse gases 

Deleted: -- 

Deleted: -- 

Deleted: may result
87

GHGs that as a class are the single “air pollutant” in the 

contribution finding. Similar to our rationale for addressing 

the group of six GHGs as one pollutant for PSD and title V 

applicability purposes, we must adhere to the definition of 

applicability, cited previously, in the final LDVR for GHGs and 

include CO2, CH4, N2O, SF6, HFCs, and PFCs. We do not have 

discretion to select only a subset of these gases in defining 

our GHG threshold metric for the permitting applicability 

purposes. See LDVR, April 1, 2010 Preamble, II.A.2.c., pp 153-4 

(discussing EPA’s exercise of discretion under section 202(a) in 

setting emissions standards applicable to emission of the single 

air pollutant). [April 1, 2010 Preamble, II.A.2.c, pp 153-4.] 

For the same reasons, we disagree that this approach is 

inconsistent with the Agency’s final action in “EPA’s 

Interpretation of Regulations that Determine Pollutants Covered 

by Federal Prevention of Significant Deterioration (PSD) Permit 

Program.” While it is the case, that only four constituent 

gases are reduced by the LDVR, the ‘air pollutant” that is 

controlled, and thus “subject to regulation,” is the group of 

six, and it is this “air pollutant” to which PSD and title V 

apply. 

We also disagree with commenters who suggested that

including all six GHGs in determining permitting applicability 

Deleted: Also, see discussion 

at III.B.2, and in EPA’s

Deleted: concerning its 

Deleted: gasses 

Deleted: that 
88

would conflict with our “absurd results” and “administrative 

necessity” rationale for the phase-in periods and applicability 

thresholds for GHGs. Even if we did have discretion to identify 

the air pollutant for PSD and title V purposes as consisting of 

only four of the six well-mixed GHGs, we do not believe that 

doing so would have any meaningful impact on the administrative 

burdens that are at the heart of our reliance on the “absurb 

results” and “administrative necessity” doctrines. The number 

of additional permitting actions and amount of additional 

permitting burden resulting from including all six GHGs, rather 

than four, in the definition is minimal. This is because the 

administrative burden of GHG permitting is dominated by CO2 and 

CH4 emission sources. For example, with a major source threshold 

set at 100,000 tpy CO2e, the combined population of sources that 

would be major for N2O, HFCs, PFCs, and SF6 accounts for fewer 

than two percent of the GHG sources that would remain covered. 

For similar reasons, we disagree with commenters who 

specifically suggest SF6 emissions should not be included in the 

applicability metric for GHGs. As we have stated earlier in 

this section, our selection of the GHG metric is driven by the 

definition of the “air pollutant” as defined in the LDVR, and in 

consideration of the final GHG endangerment finding. SF6 is 

specifically included as one of the “well-mixed greenhouse 

Formatted: Subscript

Formatted: Subscript

Formatted: Subscript

Deleted: bases

Deleted: address a subset

Deleted: the exclusion of 

some gases is necessary to 

address 

Deleted: concerns or to 

avoid an absurd results 

scenario. For our final 

action, we are phasing-in 

applicability thresholds 

based on the sum of all six 

well-mixed GHGs that are 

fully consistent with both 

the administrative necessity 

and absurd results arguments 

that we base our tailoring 

action on. We have 

carefully developed these 

thresholds based on a 

consistent definition of the 

pollutant with the LDVR GHG 

and to avoid creating an 

overwhelming number of 

permitting actions that 

would be unmanageable for 

permitting authorities and 

sources. Moreover, the 

solution offered by 

commenters – regulating four 

rather than six gases – 

would make little difference 

in addressing overwhelming 

permitting burdens

Deleted: The 

Deleted: ‘
89

gases” in the definition of air pollutant in the contribution 

finding, and is included in the definition of the air pollutant 

in the LDVR for which that rule is applicable. We do not 

believe we have the discretion to define the “air pollutant” 

differently for PSD and title V applicability purposes than the 

definition of the “air pollutant” that is regulated elsewhere. 

In any event, including SF6 emissions based on the thresholds 

finalized in this rulemaking does not add an excessive 

administrative burden for permitting authorities. Based on our 

threshold evaluation study, we estimate that less than 40 

sources of SF6 nationwide would exceed the 100,000 tpy CO2e 

threshold. Furthermore, SF6 is a high GWP gas and, as discussed 

elsewhere, we have included a mass-based trigger for high GWP 

gases that will likely have the effect of further reducing this 

count. 

For the same reasons, we disagree with the commenters who 

suggest we include black carbon and other short-lived climate 

forcers to the list of GHGs, and well as commenters asking for 

an exclusion of CH4 and N2O. The definition of the air 

pollutant, as cited in the LDVR, includes CH4 and N2O and does 

not include black carbon or other short-lived gases. 

3. Use of GWP vs. mass-based GHG thresholds

Formatted: Subscript

Formatted: Subscript

Deleted: cannot identify 

different subsets of 

individual GHGs for 

different source categories.

Moreover, 

Deleted: ; based

Deleted: specifically with 

respect to 

Deleted: gases

Deleted: We believe that the 

inclusion of these SF6

sources is entirely 

consistent with the 

definition of the air 

pollutant subject to 

regulation, as based on the 

LDVR definition for 

applicability and described 

above, and there is no basis 

for exclusion of these 

sources due to 

administrative necessity 

concerns or absurd result 

arguments. Similarly, 

Deleted: those 

Deleted: 

Deleted: Determining What GWP 

Values are to be Used 
90

For the reasons discussed previously, we are determining 

permit program applicability based on the sum-of-six well-mixed 

gases that comprise the GHG air pollutant. This section 

discusses our use of both the CO2e metric and mass emissions of 

the GHGs for applicability purposes. 

Under our proposal, a source’s emissions of all six GHGs 

would be combined into a single metric by multiplying the mass 

of each individual GHG (in tpy) by its GWP value, and summing 

these products to determine the total emissions of the GHG 

pollutant in tpy CO2e. We received comments on this aspect of 

the proposed metric. Several commenters explicitly support the 

use of GWP and the CO2e metric for GHG emissions. These 

commenters believe EPA has the authority to select an 

appropriate metric to measure GHGs in the PSD program, and 

policy considerations support the choice of GWP. Some of them 

note that GWP is a widely-used metric which employs 

internationally-recognized conversion factors to compare GHGs 

based upon their climate properties, and some add that states 

and local areas that have climate action plans for GHG 

reductions use CO2e. Some of these commenters believe this 

metric will ensure a standard measure across all permitting 

agencies and will lead to a more effective system for permitting 

authorities and create more opportunities to reduce emissions 

Deleted: Numerous commenters 

expressed concerns about the 

proposal
91

over the full class of GHGs, rather than focusing on reducing 

individual GHGs.

On the other hand, some commenters oppose the use of GWP 

and CO2e, believing that thresholds should be based on individual 

mass-based emissions for each GHG. Some of these commenters 

felt that EPA has no discretion to ignore the metric for 

regulation established by Congress for PSD in section 169 of the 

Act. Some commenters were also concerned that the use of CO2e 

will complicate the implementation of BACT because sources that 

trigger PSD will be required to install BACT for each regulated 

pollutant, not for CO2e. As a result, a source that exceeds the 

threshold primarily due to its CO2 emissions would be forced to 

install BACT for all other individual GHGs, regardless of how 

minor those other emissions may be. Finally, a commenter was 

concerned that use of GWP would complicate implementation 

because GWP values can sometimes change.

In our proposal preamble discussion of GHG metric, EPA also 

raised the possibility of including a limitation in the metric 

to address the prospect (expected to occur only rarely) that 

high-GWP gases could be emitted in quantities less than 

statutory thresholds for PSD and title V but nevertheless exceed 

the proposed thresholds in terms of CO2e. Most commenters on 

this subject support a dual threshold under which a source would 
92

be subject to title V or PSD only if its GHG emissions exceeded 

both the statutory thresholds on an actual tonnage basis and the 

tailored thresholds on a CO2e basis. Commenters supporting this 

approach felt that it would be unlawful to apply PSD when GHGs 

are below the statutory thresholds, or when there is not a net 

emissions increase. Others added that the complexity of 

accounting for emissions according to both mass and GWP should 

be manageable and is not a reason to ignore the role of mass–

based emission rates in determining the applicability of PSD 

requirements. Additionally, one commenter observed that a dual 

threshold is consistent with phasing in the tailoring rule and 

is an effective way to address the current uncertainty 

surrounding how to measure high-GWP gases such as SF6. In 

contrast, a few commenters stated they do not support a dual 

threshold, primarily on the grounds that there is no benefit to 

the added complexity.

After considering these comments, we have decided to adopt 

applicability thresholds based on a CO2e metric for the sum-ofsix well-mixed gases, and also to adopt an additional mass-based 

threshold for the sum-of-six gases as discussed in the proposal. 

First, as discussed in the previous section, we have explained 

why the appropriate pollutant for PSD purposes is the single 

pollutant GHG, which is composed of the six well-mixed gasses. 
93

Regarding the CO2e metric, we continue to believe there are a 

number of advantages, as laid out in the proposal, to a CO2e

measure that would not be available if we used only a mass-based 

metric. These include: (1) a CO2e metric, by incorporating the 

GWP values, best addresses the relevant environmental endpoint, 

which is radiative forcing of the GHGs emitted; (2) when 

combined with a sum-of-six gases approach, the CO2e metric best 

allows for consideration of their combined effects when sources 

emit any one or combination of the six well-mixed GHGs; (3) a 

cumulative CO2e metric is consistent with the metric used in the 

mandatory reporting rule and other related rules and guidelines; 

and (4) a CO2e metric allows more flexibility for designing and 

implementing control strategies that maximize reductions across 

multiple GHGs. We recognize the tension between the mass-based 

metric in the statute and the CO2e-based metric we are adopting 

in this rule, but as discussed later, we will address this by 

also retaining the mass-based metric. Moreover, given our need 

to tailor our approach to covering sources of GHGs, we believe 

that the considerations driving our choice to also use a CO2ebased metric are appropriate for defining the phase-in and allow 

for permitting resources to be directed at those sources and 

modifications that have the greatest impact on radiative forcing 

of the GHGs emitted. 
94

We recognize the concern of commenters who stated that we 

cannot ignore the statutory thresholds based on the mass-based 

emissions of an air pollutant as described under CAA section 

169(1). As we mentioned in the proposal, because both the PSD 

and title V statutory thresholds are expressed on a mass basis—

i.e., tons of a pollutant with no weighting values applied—we 

were concerned from a legal standpoint that the metric proposed 

(CO2e) could have the effect of subjecting to PSD or title V 

requirements a source whose emissions fall below the statutory 

threshold limits on a strictly mass basis, but whose CO2e-based 

emissions exceed the CO2e thresholds we establish under the 

tailoring rule. As an example, in rare instances it is possible 

that a source may emit only a non-CO2 GHG in very small amounts, 

on a mass basis, but one that carries a very large GWP. In this 

case, it is possible that the source may emit the GHG in amounts 

that fall below the PSD and/or title V statutory applicability 

threshold (100 or 250 tpy, as applicable) on a mass basis, but 

exceed the 100,000 CO2e PSD and title V applicability thresholds 

for step 2 in this action. Under these circumstances, without a 

mass-based threshold, the source would trigger PSD and title V 

for its CO2e emissions even though its GHG mass emissions would 

not, in fact, exceed the statutory triggers. 
95

Upon review of the comments pertaining to this issue and 

further analysis of the legal and programmatic implications, we 

are adopting a two-part applicability process, for both major 

source applicability determinations for GHGs under PSD and title 

V and for determining if a net increase has occurred in PSD 

applicability determinations for modifications. As explained in 

the RTC, we accomplish this two-step applicability approach by 

continuing to rely on the existing mass-based applicability 

provisions in the current regulations, and by including new 

regulatory provisions that add a definition of "subject to 

regulation" that in turn includes the phase-in thresholds. 

Similarly, for PSD modification reviews and associated netting 

analyses, the same two-step process must be used. Our summary 

in section IV.A described how we expect this provision to be 

implemented in practice. 

We acknowledge that the possibility of changing GWP values 

is a downside to the use of CO2e for the GHG metric, and we 

address this comment in the next section, where we discuss our 

plan to codify GWP values. By codifying GWP, any changes will 

be manageable, and, in our judgment, will not outweigh the 

benefits of a CO2e-based approach. We also acknowledge that a 

CO2e-based approach may appear to complicate the BACT review and 

implementation process. However, we disagree with the 
96

commenter’s ultimate conclusion that BACT will be required for 

each constituent gas rather than for the regulated pollutant, 

which is defined as the combination of the six well-mixed GHGs. 

To the contrary, we believe that, in combination with the sumof-six gases approach described above, the use of the CO2e metric 

will enable the implementation of flexible approaches to design 

and implement mitigation and control strategies that look across 

all six of the constituent gases comprising the air pollutant 

(e.g., flexibility to account for the benefits of certain 

methane control options, even though those options may increase 

CO2). Moreover, we believe that the CO2e metric is the best way 

to achieve this goal because it allows for tradeoffs among the 

constituent gases to be evaluated using a common currency.

4. Determining What GWP Values are to be Used 

 At proposal, we proposed to link the calculation of CO2e for 

GHGs to GWP values in EPA’s “Inventory of U.S. Greenhouse Gas 

Emissions and Sinks” (GHG Inventory). See, e.g., proposed 40 

CFR 51.166(b)(58). Numerous commenters expressed concerns about 

this proposal on various grounds, including the following: 

• The EPA should follow the proper notice-and-comment 

procedures and the requirements of the Information Quality 

Act (IQA) for the relevant technical underpinnings of the 

proposal. The EPA relies upon the GWPs of the IPCC without 

Deleted: (see, e.g., proposed 

40 CFR 51.166(b)(58)) 

Deleted: because that 

document may change from 

year to year. 

Representative comments 

include

Deleted: <#>It is important 

to ensure that all 

permitting agencies are 

using the same calculations 

for the determination of 

CO2e for GHGs. Use of EPA’s 

document, which is updated 

annually, should address 

this issue, provided this 

information is provided in 

annual guidelines for 

permitting agencies.¶

Deleted: 

Deleted: 
97

providing the supporting data for review, and it is 

inappropriate to use this as a basis for this rule without 

first making all the raw data available for public 

inspection and comment. 

• The EPA cannot tie the definition of GWP to the GHG 

Inventory because it is a non-regulatory document that may 

be changed without notice-and-comment rulemaking. Before 

EPA uses a new GWP, that GWP must be subject to notice and 

comment to comply with the requirements of CAA section 307 

and the Administrative Procedure Act (APA). 

• An annual update of GWP would create a moving target for 

sources conducting applicability determinations and 

assessing compliance with minor NSR and PSD emission 

limits. The EPA needs to ensure that applicability and 

compliance with limits continue to be based on the GWP that 

existed when the determination was made or the limit was 

established. 

• The EPA should freeze the GWP at the current values by 

incorporating those values into the regulation. The EPA 

could still revise the “NSR” GWP, but would have to revise 

the regulation to do so. 

Commenters added that it is important to ensure that all 

permitting agencies are using the same calculations for the 

Deleted: 

Deleted: 
98

determination of CO2e for GHGs.

We agree with commenters who suggested we should codify, 

either in the Tailoring Rule or through reference to codified 

values in another rulemaking, the GWP values to be used in 

permitting analyses. We agrees that this approach provides

certainty as to which GWP values need to be used and permitting 

authorities and sources to plan appropriately for possible 

changes in the GWP values. As mentioned in the comments, 

recommended GWP values from IPCC can change over time. While 

this is infrequent – the last such changes were in 2007—when it 

occurs, there are generally significant lag times in universal 

adoption of new values because of inconsistencies that could be 

created in national inventories and emission reporting 

mechanisms. In a regulatory setting, such as in the permitting 

programs, this could potentially create significant 

implementation issues, such as when a GWP change occurs while a 

permit action is in progress.14 EPA also recognized similar 

potential implementation issues in developing its final 

mandatory reporting rule for GHGs, and codified in the 

 14 We note that our approach does not entirely avoid the 

possibility that a GWP change can occur while a permit is in 

progress although it will ensure advance notice of such a 

change. In the event that we plan to propose a change to GWP 

values, we will work with permitting authorities as necessary to 

provide guidance to sources on transitional issues. 

Formatted: Font: (Default) Courier

New, Superscript

Formatted: Font: (Default) Courier

New

Deleted: tailoring rule 

Deleted: so that there is 

Deleted: can 

Deleted: 14
99

regulatory text for that rule the GWP values to be used in 

reporting GHGs as part of that final rulemaking. 

For these reasons, we have decided to follow the approach 

in the mandatory reporting rule and require that for PSD and 

title V permitting requirements, wherever emissions calculations 

are performed, that permitting authorities and sources use GWP 

values that are codified in EPA rules. We will establish the 

GWP values for PSD and title V rules based on a cross-reference 

to the values that are codified in the EPA’s GHG mandatory 

reporting rule. 74 FR 56,395, Table A-1 to Subpart A of Part 98 

– Global Warming Potentials. Any changes to Table A-1 of the 

mandatory GHG reporting rule regulatory text must go through a 

notice-and-comment regulatory process. In this manner, the 

values used for the permitting programs will reflect the latest 

values adopted for usage by EPA after a formal regulatory 

process and will be consistent with those values used in the 

EPA’s GHG mandatory reporting rule. Furthermore, the lead time 

for adopting changes to that rule will provide a transition time 

to address implementation concerns raised by commenters. 

5. Use of Short Tons vs. Metric Tons 

 We proposed that the GHG metric would be expressed in terms 

of English (or short) tons, rather than metric (or long) tons. 

A few commenters support using short tons for this purpose. 

Deleted: s

Deleted: this reason

Deleted: For consistency with 

the mandatory reporting 

rule, we 

Deleted: [Reference: 

Deleted: , FR, Vol.74, No. 

209, p. 56395]

Deleted: proposal 

Deleted: 

Deleted: 4.

Deleted: mong those who 

commented specifically on 

this topic, a

Deleted: , but others
100

Others prefer the use of metric tons, and most of the them note 

that the GHG Reporting Rule is based on metric tons and believe 

that the Tailoring Rule should be consistent with that rule. 

These commenters believe that using different units in the two 

rules would be confusing and could result in sources that are 

not subject to the GHG Reporting Rule becoming subject to PSD. 

Some of the commenters add that various “cap and trade” 

legislative proposals also quantify GHGs in metric tons. A few 

other commenters recommend that EPA harmonize the applicability 

thresholds established under the Tailoring Rule and the GHG 

Reporting Rule without expressing a preference for short or 

metric tons. 

We are finalizing our proposal to use short tones because 

short tons are the standard unit of measure for both the PSD and 

title V permitting programs and the basis for the threshold 

evaluation to support this rulemaking. Calculation inputs for 

PSD are typically prepared in English units (e.g., lbs of fuel, 

MMBtu’s, etc.) which is the common convention for all PSD 

analyses and the units of the statutory thresholds under the 

Act. 

It is true that the GHG mandatory reporting rule uses 

metric tons, but this does not create an inconsistency between 

permitting programs and the reporting rule because the two rules 

Formatted: Underline

Formatted: Indent: First line: 0.5"

Deleted: . Most

Deleted: latter commenters

Deleted: being

Deleted: Short

Deleted: We do recognize

Deleted: . However, we note 

that 

Deleted: ,
101

already use different applicability approaches. Although we 

originally proposed 25,000 tpy as the major source level for 

permitting programs, which was similar to the threshold in the 

reporting rule, we decided to adopt substantially higher 

thresholds in the final rule. Furthermore, even if the numbers 

were similar, the thresholds used for the permitting programs 

are based on actual emissions, while the PSD and title V 

programs are based on potential to emit. Therefore, we are less 

persuaded by arguments for consistency, and believe it is more 

important for ease of permit program implementation to ensure 

that GHG emissions calculations for PSD and title V will build 

on the same set of input variables used to develop short-ton 

based estimates for non-GHG pollutants. Thus, the use of short 

tons should actually facilitate the development of the GHG 

emission estimate. It would likely be more confusing to require 

a multi-pollutant PSD applicability analysis to present 

emissions information using different units for different 

pollutants, as would be the case if we required metric tons for 

GHG but continue to use short tons for every other pollutant. 

Finally, we do not expect this choice to introduce additional 

complexity because the conversion between short tons and metric 

tons is a very simple calculation. Therefore, based on these 

considerations we are requiring that short tons be used as the 
102

basis for emission calculations used to meet PSD and title V 

permitting requirements. 

B. Rationale for Thresholds and Timing for PSD and Title V 

Applicability to GHG Emissions Sources

 In this subsection, we describe our legal and policy 

rationale for our determinations concerning PSD and title V 

applicability to GHG emissions sources. This subsection 

includes: (1) an overview of our rationale; (2) data concerning 

costs to sources and administrative burdens to permitting 

authorities; (3) a review of the Chevron legal framework and the 

“absurd results,” “administrative necessity,” and “one-step-ata-time” doctrines, as well as a review of how those doctrines 

fit into the Chevron framework; (4) an overview of the relevant 

PSD and title V requirements and their legislative history; (5) 

our application of the “absurd results” doctrine for tailoring 

the PSD requirements; (6) our application of the “absurd 

results” doctrine for tailoring the title V requirements; (7) 

our plans to issue further rulemaking that will address the 

“absurd results” basis for both PSD and title V requirements; 

(8) our rationale for the phase-in schedule for applying PSD and 

title V to GHG sources; (9) our application of the 

“administrative necessity” basis for tailoring the PSD and title 

Deleted: , including the 

following parts

Deleted: features of the

Deleted: programs
103

V requirements; and (10) our application of the “one-step-at-atime” basis for tailoring the PSD and title V requirements. 

1. Overview 

Under the familiar Chevron two-step approach to 

construction of agency-administered statutes, the agency must 

first, at Chevron step 1, determine whether Congress's intent in 

a particular provision on a specific question is clear; and if 

so, then the agency must follow that intent. If the intent of 

the provision is not clear, then the agency may, under Chevron

step 2, fashion a reasonable interpretation of the provision. 

The best indicator of congressional intent is the literal

meaning of the provision and generally, according to the 

caselaw, if the literal meaning addresses the specific question, 

then the agency must follow the literal meaning. 

However, the courts have developed three doctrines relevant 

here that authorize departure from a literal application of 

statutory provisions. The first is the “absurd results” 

doctrine, which authorizes such a departure if the literal 

application would produce a result that is inconsistent with 

congressional intent, and particularly if it would undermine 

congressional intent. The judicial doctrine of “administrative 

necessity” authorizes an agency to depart from statutory 

requirements if the agency can demonstrate that the statutory 

Deleted: plain 

Deleted: plain 

Deleted: plain 

Deleted: ..

Deleted: it 
104

requirements, as written, are impossible to administer. The 

“one-step-at-a-time” doctrine authorizes an agency, under 

certain circumstances, to implement a statutory requirement 

through a phased approach. 

Each of the three doctrines fits into the Chevron framework 

for statutory construction because each of the three is designed 

to effectuate congressional intent. Moreover, each of the 

doctrines can, at least in some cases, generally point to 

similar conclusions. For example, under the “absurd results” 

doctrine, the agency may vary from the statutory requirements 

only to the extent necessary to adhere to congressional intent, 

if congressional intent is clearly expressed, or to reasonably 

interpret the statute, if congressional intent is not clearly 

expressed. In the case of the “administrative necessity” 

doctrine, the agency must first attempt to mitigate 

administrative problems through techniques consistent with the 

statutory requirements, and, if variance from the statutory 

requirements nevertheless is necessary to allow 

administrability, the variance must be limited as much as 

possible. Under the one-step-at-a-time doctrine, the agency is 

required to adhere to the statutory requirements, but through a 

step-by-step approach. 

Deleted: s

Deleted: to adhere to that 

intent, 

Deleted: , to reasonably 

interpret the statute
105

To apply the statutory PSD and title V applicability 

thresholds literally to sources of GHG emissions would bring 

tens of thousands of small sources and modifications into the 

PSD program each year, and millions of small sources into the 

title V program. These extraordinary increases in the scope of 

the permitting programs, coupled with the resulting burdens on 

the small sources and on the permitting authorities, would be 

several hundred-fold more than what Congress contemplated in 

enacting the PSD and title V programs. Moreover, the great 

majority of additional sources brought into the PSD and title V 

programs would be small sources that Congress did not expect 

would need to undergo permitting. Further, the administrative 

strains would lead to multi-year backlogs in the issuance of PSD 

and title V permits, which would undermine the purposes of those 

programs. Sources of all types – whether they emit GHGs or not 

– would face long delays in receiving PSD permits, which 

Congress intended to allow construction or expansion. 

Similarly, sources would face long delays in receiving title V 

permits, which Congress intended to promote enforceability. For 

both programs, the addition of enormous numbers of additional 

sources would provide little benefit. In the case of PSD, the 

large number of small sources that would be subject to control 

constitute a relatively small part of the environmental problem. 
106

In the case of title V, a great many of the sources that would 

be newly subject to permit requirements would have “empty” 

permits, that is, permits that do not include any applicable 

requirements, and that therefore serve little purpose. For 

these reasons, the “absurd results” doctrine applies to avoid a 

literal application of the thresholds. By the same token, the 

impossibility of administering the permit programs brings into 

play the “administrative necessity” doctrine. This doctrine 

also justifies not applying the PSD or title V applicability 

threshold provisions literally to GHG sources. 

The situation presented here is exactly the kind that the 

“absurd results,” “administrative necessity,” and “one-step-ata-time” doctrines have been developed to address. Separately 

and interdependently, they authorize EPA to tailor the PSD and 

title V applicability provisions through a phased program as set 

forth in this rule, and to use the initial period of phase-in to 

develop streamlining measures that would facilitate applying PSD 

and title V on a broader scale without overburdening sources and 

permitting authorities. In this manner, the phased approach 

reconciles the language of the statutory provisions with the 

results of their application and with congressional intent. 

2. Data Concerning Costs to Sources and Administrative Burdens 

to Permitting Authorities 

Deleted: EPA to avoid a 

literal application of the 

Deleted: They
107

 This final action concerning applicability of PSD and title 

V to GHG-emitting sources, including the decisions on timing for 

the selected permitting thresholds, is based on our assessments 

of both the costs to the regulated sources to comply with PSD 

and title V permitting requirements and the administrative 

burdens to the permitting authorities to process PSD and title V 

permit actions for GHG-emitting sources. This section provides 

a summary of our cost and administrative burden assessments of 

permitting that would be required in the absence of any 

tailoring as well as under various tailoring options. 

Our estimates of costs to the sources and administrative 

burdens to the permitting authorities from PSD and title V 

applicability for GHG emissions are based on labor and cost 

information from the existing Information Collection Requests 

(ICRs) for PSD and title V programs.15 We applied the same basic 

methodology used for the proposal, which incorporates 

information on numbers and types of affected sources and 

estimated permitting actions. We evaluate administrative 

burdens in terms of staffing needs, time for processing permits, 

and monetary costs, and we make some judgments about how those 

 15 Summary of Methodology and Data Used to Estimate Burden 

Relief and Evaluate Resource Requirements at Alternative 

Greenhouse Gas (GHG) Permitting Thresholds;” Prepared by EPA 

Staff; March 2010. 

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burdens would affect the permitting authorities’ ability to 

effectively manage and administer their programs with the 

addition of GHG emission sources. We present the administrative 

burden data for applying PSD and title V requirements at the 

literal statutory thresholds -- that is, the 100/250 tpy levels 

for PSD and the 100 tpy level for title V – as well as at other 

thresholds, which range from 25,000 tpy CO2e to 100,000 tpy CO2e. 

We have significantly revised upwards our assessments of costs 

to sources and administrative burdens since proposal, and we 

summarize later our reasons for doing so. We also present 

significant comments concerning administrative burdens, and our 

responses to those comments. 

 In the next section, concerning legal and policy rationale 

for our actions, we discuss how these data on costs to the 

sources and administrative burdens to the permitting authorities 

informed our decisions that PSD and title V requirements should 

not, at present, be applied to GHG-emitting sources under the 

literal terms of the statutory thresholds as well as our 

decisions concerning what thresholds to apply for Steps 1 and 2 

of the applicability phase-in approach and the applicability 

floor of 50,000 tpy CO2e. 

a. Costs to Sources 

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 As we did at proposal, we have estimated costs to the 

sources of complying with PSD and title V starting from the data 

in the ICR. We recognize that the sizes of the sources, as 

measured by their emissions, that would be swept into the PSD 

and title V programs would vary greatly, and that their 

permitting costs would vary as well. For example, their PSD 

permitting costs would depend on the amount and types of their 

emissions and their control requirements. Accordingly, we have 

determined average costs, as described later. 

For PSD, at proposal, we estimated that on average, an 

industrial source would incur costs of $84,500 to prepare the 

PSD application and receive the permit, and on average, a 

commercial or residential source would incur costs of 20 percent 

that amount, or $16,900. 74 FR at 55,337 col. 3 to 55,339 col. 

3. For this action, we retain the same burden estimates for an 

average industrial source. This type of source would need 866 

hours, which would cost $84,500, to prepare the application and 

the PSD permit. However, based on comments received, we have 

determined that a more accurate estimate for an average 

commercial or residential source is 70 percent of that amount of 

time that an industrial source would need, up from our proposal 

of 20 percent. Thus, an average commercial or residential 

source would need 606 hours, which would cost $59,000, to 

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prepare the PSD application and receive the permit. We are 

increasing this time over what we proposed because we now 

recognize that virtually all commercial and residential will 

have no experience with the PSD permitting process, and 

therefore will face a significant learning curve that will 

entail more time to complete the application, develop control 

recommendations, and take the other required steps. We believe 

this learning period could extend from two to possibly 4 years 

or more from the date that the sources become subject to PSD 

requirements, depending on the type and actual number of new 

sources that come in for permitting. In addition, we expect 

that in many cases, draft PSD permits for GHGs will receive 

comments from various stakeholders, from citizens groups to 

equipment vendors, who will seek to participate in the permit 

process, and that all this could add to the hours that the 

permittee will need to invest in the process.16 The actual costs 

to sources to install BACT controls, while still uncertain at 

this point, would likely add additional costs across a variety 

of sources in a sector not traditionally subject to such 

permitting requirements. 

 16 Summary of Methodology and Data Used to Estimate Burden Relief and Evaluate 

Resource Requirements at Alternative Greenhouse Gas (GHG) Permitting Thresholds;” Prepared 

by EPA Staff; March 2010.

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For title V, at proposal, we estimated that on average, an 

industrial source would incur costs of approximately $46,400 to 

prepare the title V application and receive the permit, and on 

average, a commercial or residential source would incur costs of 

10 percent that amount, or almost $5,000. 74 FR at 55,338 col. 

1 to 55,339 col. 3. For this action, we retain the same burden 

estimates for an average industrial source. This type of source 

would need 350 hours, which would cost $46,400, to prepare the 

application and the title V permit. However, we have determined 

that a more accurate estimate for an average commercial or 

residential source is 50 percent of that amount of time that an 

industrial source would need, up from our proposal of 10

percent. Thus, an average commercial or residential source 

would need about 175 hours, which would cost $23,200, to prepare 

the title V application and receive the permit. This increase 

is due to the same reasons as with the PSD program just 

discussed. We now recognize that virtually all commercial and 

residential sources will have no experience with the title V 

permitting process, and therefore will face a significant 

learning curve that will entail more time to, for the first 

time, assess their GHG emissions (because such sources are not 

covered by EPA’s mandatory reporting rule), complete the 

application, respond to permitting authority comments, meet 

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112

other title V administrative requirements, and respond to 

interested stakeholders.17 

b. Administrative Burdens to Permitting Authorities 

(1) Estimated Permitting Authority Burden at Proposal 

As at proposal, we estimated the administrative burdens to 

the permitting authorities at the various threshold levels for 

PSD or title V applicability as follows. First, for a 

particular threshold level, we estimated the number of GHGemitting sources that would be subject to PSD requirements 

because they would undertake new construction or modification, 

and the number of existing sources that would be subject to 

title V requirements. Second, we estimated the average 

additional administrative burden and cost of each PSD permitting 

action and each title V permitting action for the GHG-emitting 

sources. Third, we multiplied those two estimates, and the 

product is the additional administrative burden at the 

particular threshold level. We employed the same methodology 

for this final rule, but, as discussed later, and described in 

more detail in our final burden analysis,18 we have updated 

 17 “Summary of Methodology and Data Used to Estimate Burden 

Relief and Evaluate Resource Requirements at Alternative 

Greenhouse Gas (GHG) Permitting Thresholds;” Prepared by EPA 

Staff; March 2010. 18 “Summary of Methodology and Data Used to Estimate Burden 

Relief and Evaluate Resource Requirements at Alternative 

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several key assumptions since the proposal as a result of our 

consideration of comments received. 

First, we present the administrative burdens at the 

statutory levels for PSD and title V applicability. At 

proposal, for the PSD program, we estimated the administrative 

burdens that would result from applying PSD at the 100/250 tpy 

major emitting facility threshold levels in two ways, as 

described in this section. We stated that at present, 280 

sources are subject to PSD each year, both for new construction 

and modifications. This figure served as the baseline from 

which to calculate increases in administrative burdens due to 

permitting GHG-emitting sources. 

The first method that we used to calculate the 

administrative burdens to the permitting authorities was in 

terms of workload hours, which we then converted to monetary 

costs. To make the workload calculation, we first estimated the 

number of GHG-emitting sources that would become subject to PSD 

through new construction and modification. Based on our GHG 

threshold data analysis, we estimated that almost 41,000 new and 

modified sources per year would become subject to PSD review. 

We first calculated the number of new sources that would become 

 

Greenhouse Gas (GHG) Permitting Thresholds;” Prepared by EPA 

Staff; March 2010. 
114

subject to PSD. To do this, we estimated growth rates for the 

various sectors, and then applied those growth rates to the 

numbers of sources in those sectors. We then calculated the 

number of modifications. To do this, we first assumed that each 

year, two percent of sources that meet or exceed the threshold 

levels for PSD applicability due to their conventional 

pollutants undertake modifications. We then calculated the 

number of sources that would meet or exceed the threshold levels 

for PSD applicability due to their GHG emissions, and applied 

the same assumption that two percent of them would undertake 

modifications. In this manner, we estimated the number of 

modifications of GHG-emitting sources that would become subject 

to PSD. 

 We noted that currently, 280 PSD permits are issued each 

year, but that applying PSD to GHG-emitting sources at the 

100/250 tpy statutory threshold levels would cause an increase 

in permits of more than 140-fold. The reason for the 

extraordinary increase in PSD applicability lies simply in the 

fact that it takes a relatively large source to generate 

emissions of conventional pollutants in the amounts of 100/250 

tpy or more, but many sources combust fossil fuels for heat or 

electricity, and the combustion process for even small 

quantities of fossil fuel produces quantities of CO2 that are far 
115

in excess of the sources’ quantities of conventional pollutants 

and that, for even small sources, equals or exceeds the 100/250 

tpy levels. 

 Based on the 140-fold increase in permits, we then 

estimated the per-permit burden on permitting authorities. As 

we stated in the proposal: 

We estimated the number of workload hours and 

cost a permitting authority would expend on each new 

source and each modification. We based these 

estimates on the workload hours and cost for 

processing permits for new sources of non-GHG 

emissions, which we derived from labor and cost 

information from the existing [Information Collection 

Requests (“ICRs”)] for PSD programs. The ICRs show 

that permitting authorities expend 301 hours to permit 

a new or modified industrial source.... 

We then made assumptions for number of workload 

hours and costs for new sources of GHG emissions. We 

assumed that permitting new industrial GHG sources 

that emit in excess of the 250-tpy threshold would be 

of comparable complexity to permitting non-GHG 

emitting industrial sources that are subject to PSD. 

Thus, for these sources, we assumed that permitting 

authorities would expend the same number of workload 

hours and costs, on a per-permit basis, as they do for 

non-GHG emitting industrial sources. On the other 

hand, for commercial and residential GHG sources that 

emit GHGs above the 250-tpy threshold (and as a result 

would be subject to the requirements of the PSD 

permitting program at this threshold level), we 

assumed that the workload hours and cost for 

permitting these sources would be significantly less 

than—only 20 percent of—the hours and cost necessary 

to prepare and issue initial PSD permits or permit 

modifications for industrial GHG sources. This 20-

percent estimate amounts to 60 hours of permitting 

authority time per residential or commercial permit. 

Based on these assumptions, the additional annual 

permitting burden for permitting authorities, on a 
116

national basis, is estimated to be 3.3 million hours 

at a cost of $257 million to include all GHG emitters 

above the 250-tpy threshold. 

74 FR at 55,301 col. 2. 

Note that at the proposal, in calculating the PSD 

administrative burdens that would occur each year due to GHG 

emissions, we did not undertake separate calculations for the 

administrative burdens associated with permitting obligations 

stemming from the GHG emissions of the 280 sources already 

subject to PSD permitting requirements due to their conventional 

pollutants. In effect, we treated these 280 sources are part of 

the over 40,000 sources that would become subject to PSD due to 

their GHG emissions. 

The second way that we evaluated the burden on permitting 

authorities was by reviewing a study conducted by state and 

local air permitting agencies. As we said in the preamble: 

In addition to conducting our burden analysis, we 

also reviewed summary information from state and local 

air permitting agencies regarding additional resources 

and burden considerations if GHG sources that emit 

above the 100/250-tpy thresholds were subjected to the 

PSD and title V programs. This information covered 43 

state and local permitting agencies, representing 

programs from different regions of the country and 

various permitting program sizes (in terms of 

geographic and source population coverage).... This 

information showed significant burdens projected by 

permitting agencies with adding sources of GHG 

emissions in terms of staffing, budget, and other 

associated resource needs. Importantly, the agencies 

based their analysis on the assumption that, for 

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117

purposes of determining whether a source is major, its 

emissions would be calculated on an actual emissions 

("actuals") basis, and not on a PTE basis. On an 

actuals basis, the agencies estimated a 10-fold 

increase in the number of permits. 

Specifically, the agencies estimated that: 

• Assuming, again, that number of permits was 

to increase by 10-fold (based on actual 

emissions), the resulting workload would 

require an average of 12 more FTEs per 

permitting authority at an estimated cost of 

$1 million/year; 

• Without the additional FTEs, the average 

processing time for a permit would increase 

to 3 years, which is three times the current 

average processing time; 

• Permitting authorities would need 2 years on 

average to add the necessary staff; 

• Permitting authorities would also need, on 

average, eight additional enforcement and 

judicial FTEs; 

• Ninety percent of the permitting agencies 

indicated that their staff would need 

training in all aspects of permitting for 

sources of GHG emissions. 

• A quarter of the permitting agencies reported 

that they were currently under a hiring freeze. 

We went on to explain that this state survey 

significantly underestimated the administrative burdens: 

It is important to reiterate that the state and 

local permitting information on burden was based on 

the number of additional facilities subject to PSD 

because their emissions of GHGs exceed the 100/250-tpy 

thresholds at actual emissions rates, not PTE-based 

emissions rates. However, the PSD applicability 

requirements are based on PTE. By adjusting the 

increase in number of permits to account for GHG 

sources that exceed the 100/250-tpy applicability 

thresholds based on their PTE emissions, EPA estimated 

a 140-fold increase in numbers of PSD permits, much 

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118

more than the 10-fold increase estimated by the states 

based on actual emissions. 

74 FR at 55,301 col. 2-3. 

In addition to PSD, we also estimated title V burdens at 

the statutory threshold. At proposal, for the title V program, 

we estimated the administrative burdens that would result from 

applying title V requirements at the 100 tpy major source 

threshold level in the same two ways as for PSD, as follows: 

The first method was to calculate the administrative burdens in 

terms of workload hours, which we then converted to monetary 

costs. To make the workload calculation, we first estimated the 

number of existing GHG-emitting sources that would become 

subject to title V. Based on our GHG threshold data analysis, 

we estimated that approximately 6 million sources would become 

subject to title V. Compared to the 14,700 title V permits 

currently issued per year, this would be an increase in permits 

of more than 400-fold. We noted, in addition, that most of the 

14,700 sources already subject to title V also emit GHGs and may 

be affected as well. 

We then described the type of work that the permitting 

authorities would need to do for these GHG-emitting sources – 

the six million that would become newly subject to title V and 

most of the 14,700 that are already subject to title V – as 
119

follows. Note at the outset that the permitting authorities’ 

workload is greater for sources newly subject to title V than 

for existing sources that seek a revised or renewed permit. As 

EPA noted in the preamble: 

[T]he[] permits [for the six million new sources] 

would need to include any requirements for non-GHGs 

that may apply to the source, such as provisions of an 

applicable State Implementation Plan (SIP). For any 

such requirements, permitting authorities would also 

need to develop terms addressing the various 

compliance assurance requirements of title V, 

including monitoring, deviation reporting, six-month 

monitoring reports, and annual compliance 

certifications. 

Adding to the burden described above would be the 

burden to add GHG terms to the 14,700 existing title V 

permits. While, in general, existing title V permits 

would not immediately need to be revised or reopened 

to incorporate GHG (because as noted above, there are 

generally not applicable requirements for GHGs that 

apply to such sources), permitting authorities may 

face burdens to update existing title V permits for 

GHG under two possible scenarios: (1) EPA promulgates 

or approves any applicable requirements for GHGs that 

would apply to such a source, which would generally 

require a permit reopening or renewal application, or 

(2) the source makes a change that would result in an 

applicable requirement for GHGs to newly apply to the 

source, such as PSD review, which would generally 

require an application for a permit revision. 

Permitting authorities will also need to process 

permit renewal applications, generally on a five-year 

cycle, and such renewals would need to assure that the 

permit properly addresses GHG. Finally they would 

have to process title V applications for new sources 

(including all the PSD sources previously discussed).

 

74 FR at 55,302 cols. 2-3. 
120

In light of those demands, we estimated the per-permit 

burden on permitting authorities as follows. Note, at the 

outset, that as with PSD, we based the workload hours on 

information in ICRs for industrial sources, and we then assumed 

that the workload for commercial and residential sources would 

be the indicated percentage of the workload for industrial 

sources: 

As with PSD, we have quantified the extent of the 

administrative problem that would result in workload 

hours and cost on the basis of information concerning 

hours and costs for processing existing title V 

permits that is indicated on ICRs. However, we 

recognize that more than 97 percent of these new 

sources would be commercial and residential sources. 

We estimate that for permitting authorities, the 

average new commercial or residential permit would 

require 43 hours to process, which is 10 percent of 

the time needed for the average new industrial permit. 

For an average existing permit, which permitting 

authorities would need to process through procedures 

for significant revisions and permit renewals, adding 

GHG emissions to the permit would result in, we 

estimate, 9 additional hours of processing time, which 

is 10 percent of the amount of time currently 

necessary for processing existing permits. We 

estimate that the total nationwide additional burden 

for permitting authorities for title V permits from 

adding GHG emissions at the 100-tpy threshold would be 

340 million hours, which would cost over $15 billion. 

74 FR at 55,302 col. 3. 

As with PSD, the second way that we evaluated the burden on 

permitting authorities at the statutory threshold was by 

reviewing a study conducted by state and local air permitting 
121

agencies of the burden of applying title V to existing GHGemitting sources at the 100 tpy statutory threshold level. As 

we said in the preamble to the proposed rule: 

[W]e also reviewed summary information from state 

and local permitting agencies, which showed 

significant burdens associated with adding GHGs in 

their title V programs in terms of staffing, budget, 

and other associated resource needs.19 Again, note 

that the permitting agencies based their estimates on 

numbers of permits that would be required from sources 

subject to the 100-tpy title V applicability threshold 

on an actuals—not PTE—basis. Based on that level, the 

agencies assumed a 40-fold increase in numbers of 

permits, and estimated that: 

• The resulting workload would require an average 

of 57 more FTEs per permitting agency at an 

estimated cost of $4.6 million/year; 

• Without the additional FTEs, the average 

processing time for a permit would increase to 

almost 10 years, which is 20 times the current 

average permit processing time; 

• Permitting authorities would need 2 years on 

average to add the necessary staff; 

• On average, permitting authorities would need 29 

additional enforcement and judicial staff; 

• Eighty percent of the permitting authorities 

indicated that their staff would need training in 

all aspects of permitting for sources of GHG 

emission. 

• A quarter of the permitting agencies reported 

that they were currently under a hiring freeze. 

 As with PSD, we added that this state survey 

significantly underestimated the administrative burdens: 

 19 “NACAA Summary on Permitting GHGs Under the Clean Air Act”; 

Memorandum from Mary Stewart Douglas, National Association of 

Clean Air Agencies to Juan Santiago, EPA/OAQPS, September 3, 

2009. 

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It is important to reiterate that, as with PSD, 

the state and local information on projected 

permitting burden is based on the number of additional 

facilities subject to title V because their emissions 

of GHGs exceed the 100-tpy thresholds at actual 

emissions rates, not the PTE-based emissions rates. 

However, the title V applicability requirements are 

based on PTE. As noted elsewhere in this preamble, 

the state and local agencies estimated a 40-fold 

increase in numbers of title V permits based on the 

amount of GHG sources' actual emissions. By adjusting 

the summary estimates provided by the state and local 

agencies to account for GHG sources that exceed the 

100-tpy threshold based on their PTE emissions, EPA 

estimated that the average permitting authority would 

need 570 more FTEs to support its title V permitting 

program. 

74 FR at 55,302 col. 3 – 55,303 col. 1. 

(2) Revisions to Proposal Estimates of Permitting Authority 

Burden 

We received numerous comments from state and local 

authorities pointing out how EPA had underestimated the 

administrative burden on the permitting authorities in the 

proposal. State and local authorities stated that in 

particular, EPA underestimated the number of modifications and 

the amount of time it would take permitting authorities to 

process permits, particularly for commercial and residential 

sources. Based on the comments and additional analysis that we 

have conducted, we are revising in several respects our 

estimates of the administrative burdens for applying PSD and 

title V at the statutory threshold levels. 
123

First we present revisions to our analysis regarding the 

burdens at the statutory levels. Before we present those 

changes, we want to note a revision to our methodology that 

affected our estimate of the number of permits currently issued 

under existing programs. We are revising upwards the number of 

sources that are already subject to PSD permitting requirements 

anyway for their conventional pollutants (“anyway” sources). 

This revision has implications both for (i) the number of 

sources that would become subject to PSD due to their GHG 

emissions; and also (ii) the baseline number of sources already 

subject to PSD, which we use to compare the amount of increases 

in administrative burden due to permitting GHG sources. At 

proposal, we stated that 280 sources each year are subject to 

PSD due to their new construction or modifications. However, 

upon further analysis, we have realized that this figure is too 

low because it includes only sources that have emissions of one 

or more NAAQS pollutants at the 100/250 tpy thresholds and that 

are located in areas of the country that are designated 

attainment or unclassifiable for all of those pollutants, and 

thus are not designated nonattainment for any of those NAAQS 

pollutants. We estimate that another 520 sources have emissions 

of one or more NAAQS pollutants at the 100/250 tpy thresholds 

and are located in areas of the country that are nonattainment 
124

for at least one of those NAAQS pollutants. Some of these 520 

sources may also emit one or more pollutants at the 100/250 tpy 

level for which their area is designated attainment or 

unclassifiable, and therefore may be subject to PSD for those 

pollutants. Accordingly, the correct number of “anyway” sources 

subject to PSD each year is the 280 sources that are located in 

areas that are attainment or unclassifiable for each pollutant 

that the sources emits at the 100/250 tpy level, plus at least 

some of the 520 sources that are located in areas that are 

nonattainment for at least one of the NAAQS pollutants that the 

sources emit at or above the 100/250 tpy threshold. In the 

absence of data on the number of nonattainment NSR permits that 

do not have a PSD component, and because we expect this to be a 

small number, we have assumed for purposes of this action, that 

each of the 520 sources is subject to PSD for at least one 

pollutant, so that we will consider all 800 sources as subject 

to PSD. Of this number, we estimate that 70 percent, or 560

sources will undergo a modification, while the remaining 240 

permitting actions involve new construction, would become 

subject to additional requirements due to their GHG emissions 

because those sources have combustion-related activities that 

would likely emit GHGs in the requisite quantities. Our 

estimate of 80 percent of permitting activities significantly 

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125

involving combustion activities is based on a review of a random 

sample of PSD permits. In total we estimate that 688 sources, 

either upon new construction or modification, would need to add 

GHG requirements to their otherwise required PSD permitting 

action.

We should also note that in this rulemaking we are 

justifying our conclusions about permitting authority 

administrative burdens on the basis of their PSD and title V 

cost as calculated on both a separate basis and a combined 

basis. That is, we believe that the administrative burdens of 

the PSD program justify our tailoring approach for the PSD 

requirements, and the administrative burdens of the title V 

program justify our tailoring approach for the title V 

requirements, but addition, the administrative burdens of both 

programs on a combined basis justify the tailoring approaches. 

Viewing the administrative burdens on a combined basis provides 

a useful perspective because most permitting authorities have a 

single organizational unit that is responsible for both the PSD 

program and the title V program, and in many cases, the same 

employees work on both programs. In addition, in some 

jurisdictions, permitting authorities issue a single, merged 

permit that includes both PSD and title V requirements. For 

these reasons, considering administrative burdens on a combined 
126

PSD and title V basis, offers a more accurate picture of the 

issues these agencies will face in transitioning to GHG 

permitting. 

Turning to the revisions to our burden estimates that we 

made as a result of public comment, we begin by noting that many 

commenters believed that we significantly underestimated the 

administrative burdens associated with the proposed thresholds 

or that the administrative burden under the proposed thresholds 

would still overwhelm the states and result in significant 

permitting delays and uncertainty for sources. Many of these 

commenters indicate that our estimate of the number of sources 

that would be subject to permitting is too low, and some add 

that we have underestimated the per-permit effort required. 

(More detail on these comments is given elsewhere on the 

methodology used in the analysis.) Several state and local 

agencies provided estimates of the increased number of permits 

and/or staff that would be required under the thresholds we 

proposed that were higher than our original estimates. 

Specifically, commenters recommended that we increase the 

estimated administrative burdens for PSD permits from 100 

percent to over 2,000 percent; and that we increase the burdens 

for title V permits from 29 percent to 240 percent. Many 

commenters indicated that EPA has not adequately accounted for 
127

“synthetic minor” sources or modification projects, stating that 

many such sources and projects will not be able to keep GHGs 

below the proposed thresholds, and those who could do so may not 

be able to establish enforceable synthetic minor limits. 

Numerous commenters also stated that the EPA has underestimated 

the rate of major modifications for GHGs under PSD. Some 

commenters assert that we underestimated the number of permits 

required for specific industry sectors, including the oil and 

gas production industry, the natural gas transmission industry, 

the semiconductor industry, the wood products industry, the 

brick industry, and landfills. Some of the state and local 

commenters also believe that we have overestimated their ability 

to hire and train sufficient staff to administer GHG permitting. 

We are persuaded by the data and arguments provided by the 

many commenters who believe EPA underestimated the number of 

permitting actions and the burdens of each action, and thus the 

overall administrative burdens associated with permitting GHG 

sources. Accordingly, we have reevaluated our assessment of 

these administrative burdens, for both the PSD and title V 

programs. In conducting this re-evaluation, we considered 

arguments made by the commenters, as well as any actual data 

they provided, and then we determined whether and how to modify 

various aspects of our detailed assessment of the burdens. 
128

Based on this consideration we have substantially revised 

upwards our estimate of administrative burdens, based on the 

analysis included in the final docket for this rulemaking.21 The 

revisions affect two elements of our analysis: (1) a 

substantial increase the number of PSD and title V permits that 

will occur at the statutory thresholds, and (2) an increase in 

the average burden estimate for each such permit. 

 Regarding the increase in our estimate of the number of 

projects that will occur, we estimated an increase in both PSD 

and title V permit actions, though the greatest changes were for 

PSD. At proposal, we estimated that, were PSD requirements to 

apply to GHG sources at the 100/250 tpy statutory levels, 40,496 

projects -- consisting of 3,299 projects at industrial sources 

and 37,197 projects at commercial or residential sources -- 

would need PSD permits each year. Some of these projects 

involve the construction of an entirely new source, but the 

majority of these are modifications. We now estimate that at 

the 100/250 tpy levels, 81,598 projects would become subject to 

 21 “Summary of Methodology and Data Used to Estimate Burden 

Relief and Evaluate Resource Requirements at Alternative 

Greenhouse Gas (GHG) Permitting Thresholds;” Prepared by EPA 

Staff; March 2010.

Deleted: , 20
129

PSD each year. These projects include 26,089 actions at 

industrial sources and 55,509 at commercial and residential 

sources. We describe our calculation of this 81,598 amount in a 

TSD.22 The great majority of these 81,598 projects that would 

become subject to PSD are modifications. We base these 

estimates on the assumption that the significance levels would 

be 100 tpy regardless of category. 

Our estimate of the number of PSD modifications is where we 

made our most significant upward revisions from our proposal, 

based on comments. Our doubling of the estimated PSD permitting 

actions – from 40,496 at proposal to 81,598 -- results from 

three separate adjustments we made to our estimates at proposal 

of the number of permit actions that would result from applying 

PSD to GHG sources. Two of these increased the number of major 

modifications, and one of these increased the number of major 

sources and modifications. The most significant adjustment, and 

one that was raised by multiple commenters, was that we 

undercounted the number of major modification projects at 

existing major sources because we did not include the existing 

projects that avoid major PSD review by either taking “synthetic 

minor” limits or by netting out for conventional pollutants, but 

 22 “Summary of Methodology and Data Used to Estimate Burden Relief and Evaluate 

Resource Requirements at Alternative Greenhouse Gas (GHG) Permitting Thresholds;” Prepared 

by EPA Staff; March 2010.

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that would not be able to avoid PSD through those mechanisms for 

GHGs. The ability and procedures for sources to achieve 

reductions, or minimize increases, due to GHGs through adoption 

of enforceable limits or through netting out have not be well 

established at this point. We believe that there will numerous 

instances, particularly for combustion-related projects, where 

it will not be possible for sources to achieve the same level of 

reductions for CO2 emissions as they do for NOx emissions, for 

example, simply because there are not as many proven control 

techniques that can reduce CO2 emissions to the same degree as 

NOx. Also, more research will be necessary in the type of 

emission units and processes resulting in GHG emissions, and how 

they operate over a wide range of utilization patterns at a 

variety of source categories, before permitting authorities will 

be able to establish procedures and rules for developing minor 

source permit limitations. Therefore, we adjusted our count of 

major modification permits under PSD upward to account for this. 

The second change to the number of permits concerns the 

general modification rate of 2 percent that we applied at 

proposal, based on historical experience across all pollutant 

types. Commenters provided information that suggest that this 2 

percent figure is an underestimate for GHG sources because their 

emissions of CO2 are high and accumulate quickly from various 

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document in the docket that 

shows comments regarding 

modifications estimate)] 
131

changes involving combustion units. Therefore, a greater 

percentage of their physical or operational changes will result 

in GHG emissions in excess of the significance levels that we 

identified at proposal. In light of these comments, we reviewed 

the source populations and pollutant mix within the various 

populations, and determined that we should revise our general 

modification rate to 4 percent for GHG sources. This 4 percent

rate was obtained by dividing the current annual major NSR 

permit actions involving modifications by the 14,700 existing 

sources. We have revised our burden analysis accordingly. 

Again, the burden analysis in the docket describes our basis for 

these calculations in more detail. 

The third adjustment to the number of permits involves our 

estimate of the number of sources with potential to emit that is 

greater than the various thresholds considered. This affects 

the number of major sources at the statutory thresholds, which 

we used to estimate the number of PSD and title V major sources, 

but also has an effect on the number of major modifications 

because the number of modifications depends on the size of the 

population of major sources. Commenters provided evidence that 

our estimates of capacity utilization (which, as described 

previously, we use for estimating potential-to-emit based on 

data for actual emissions) for the general manufacturing source 

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132

category (referred to as “unspecified stationary combustion” in 

our analysis) and for the oil and gas industry were not 

accurate. In our proposal, our estimated range for capacity 

utilization for ‘unspecified stationary combustion” varied from 

70 to 90 percent depending on manufacturing category. For the 

oil and gas industry, our estimate was 90 percent. We received 

comments indicating that these utilization rates are higher than 

what is normally achieved in real-world conditions, particularly 

for smaller manufacturing type facilities. Accordingly, in this 

action, we are using a 50 percent capacity utilization rate for 

both of these source categories, which better reflects what can 

be deemed reasonable operation under normal conditions for 

facilities in these source categories. This adjustment 

increased the overall number of affected facilities at various 

threshold levels and we have revised our burden analysis 

accordingly. 

 A few commenters asserted that we underestimated the number 

of residential homes, commercial buildings, and retail stores 

that would be subject to permitting requirements because these 

commenters believed the estimate in EPA’s TSD was based on 

actual emissions from space heating equipment rather than PTE. 

We wish to clarify that our threshold analysis estimates for the 

number of residential and commercial sources (as well as all 
133

other sources) did use a PTE basis. To calculate the PTE amount 

for these sources, we extrapolated from the actual emissions 

data for the residential and commercial sources. Specifically, 

we assumed that a typical residential facility operates its fuel 

combustion sources at only 10 percent of its capacity and a 

typical commercial facility operates at only 15 percent of its 

capacity. Based on these assumptions, we multiplied residential 

actual emissions by a factor of 10, and commercial actual 

emissions by a factor of 6.6 to obtain PTE-based estimates. 

There is very little information available on the capacity 

utilization rates of fuel combustion equipment at different 

types of residential and commercial facilities, but we believe 

our methodology was reasonable for these types of sources and we 

did not adjust it in response to this comment. Information on 

the development of these estimates is provided in our Technical 

Support Document for Greenhouse Gas Emissions Thresholds 

Evaluation. 

 The second source of upward revisions to our 

administrative burden estimate is that we are increasing the 

estimated average cost to permitting authorities of issuing each 

PSD and title V permit at the statutory thresholds. At 

proposal, we estimated that for PSD permits, permitting 

authorities would expend, on average, 301 hours to permit an 
134

industrial source of GHG emissions, and 20 percent of that time, 

or 60 hours to permit a commercial or residential source. After 

estimating that amount of workload, we went on to estimate the 

monetary cost to permitting authorities of that workload. 

Similarly, for title V permits, we estimated at proposal that 

permitting authorities would expend 10 percent of the number of 

hours needed to process an industrial permit in order to process 

a commercial or residential permit for GHG sources. 

We received comments from both permitting authorities and 

sources asserting that our methodology underestimated the 

administrative burden on grounds that (1) our methodology fails 

to recognize that when a source triggers PSD for conventional 

pollutants, additional labor hours would be required to issue 

BACT for GHGs; (2) our estimate of 60 hours (versus 301 hours) 

to issue PSD permits to commercial and residential sources of 

GHGs is unrealistically low; (3) our estimate failed to account 

for the increase in the complexity of permits for criteria 

pollutants due to (i) increases in criteria pollutant emissions 

becoming newly subject to BACT at sources that are major only 

for GHGs, which will result in increased permitting and (ii) 

BACT controls for criteria pollutants (e.g., an oxidizer for 

VOC) may result in significant GHG emissions, triggering an 

additional BACT determination.; and (4) our methodology failed 
135

to account for the significant additional PSD and title V 

burdens due to sources that obtain federally enforceable permit 

limits on GHGs in order to become “synthetic minors” and thereby 

avoid PSD (and possibly also title V). 

 Based on these comments and our own reassessment of 

permitting actions created by the addition of GHGs, we have 

revised upwards in several ways our estimate of the additional 

per-permit costs of applying PSD and title V to GHG sources, 

including the following: First we have added an estimate of the 

additional permitting cost for adding a GHG component to 

“anyway” PSD and title V permitting actions for conventional 

pollutants. We estimated this burden based on information in 

the comments together with our own judgment about how to adjust 

the burden numbers contained in the current supporting 

statements for our approved permitting ICRs. These adjustments 

are found in our revised burden estimate document 23

Second, we have raised the per-permit burden hours for 

commercial and residential sources for PSD and title V. At 

proposal, our estimates were based on the fact that many of 

these permits will be technically simpler due to such factors as 

a lower number of emissions points, simpler processes, and less 

 23 “Summary of Methodology and Data Used to Estimate Burden Relief and Evaluate 

Resource Requirements at Alternative Greenhouse Gas (GHG) Permitting Thresholds;” Prepared 

by EPA Staff; March 2010.

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required modeling. However, commenters pointed out that, until 

EPA streamlines its permitting procedures, there are many 

permitting activities that represent a fixed cost, such as 

public notice, hearing, and response to comment activities. In 

addition, we agree, as commenters pointed out, that many of 

these sources will need significantly more permitting-authority 

staff time to assist them in the permit application and 

preparation process because of their lack of experience with 

these requirements. In addition, permitting authorities will 

have little, if any, experience in permitting commercial and 

residential sources, and therefore will face a learning curve 

that will entail more time to take permitting action. In 

addition, we expect that in many cases PSD and title V permit 

applications for GHGs will receive comments from various 

stakeholders, from citizens groups to equipment vendors, who 

will seek to participate in the permit process, and responding 

and revising permits accordingly will add to the hours that the 

permitting authority will spend. 

As a result, we raised the PSD per-permit hours for various 

steps in the permitting process, as described in the burden 

estimate document. While we continue to estimate that 

permitting authorities will expend, on average, 301 hours to 

issue a PSD permit to an industrial source, and that this would 

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cost $23,243, we now recognize that a permitting authority would 

expend 70 percent of that time or 210 hours, to permit a 

commercial or residential source, which would cost $16,216. 

Similarly, for title V, while we continue to estimate that 

permitting authorities will expend, on average, 428 hours to 

issue a title V permit to an industrial source, and that this 

would cost $19,688, we now recognize that a permitting authority 

would expend 50 percent of the time, or 214 hours, to permit a 

commercial or residential source, which would cost $9,844. 

We disagree with commenters who suggested that by basing 

our estimates on the numbers of newly constructing and modifying 

sources with high enough emissions to qualify as major emitting 

facilities, we failed to account for the costs of sources that 

seek “synthetic minor” permits to avoid PSD, and possibly title 

V, requirements. In fact, our methodology includes sources that 

might take such limits as newly-major sources for their GHG 

emissions; and therefore we count the full administrative burden 

associated with a PSD permit and a title V permit for those 

sources. In effect, we assume that such sources would go 

through PSD or title V permitting, rather than take “synthetic 

minor” limits. We take this approach because although we 

suspect that there may, in fact, be significant synthetic minor 

activity, we do not have data that would allow us to determine 

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whether, and how many of, these sources will be able to adopt 

“synthetic minor” limits or restrict their operations to obtain 

minor source permitting status. Nor do we have data on the 

amount of the administrative burden that would fall on any 

particular permitting authority to establish a “synthetic minor” 

limit, except that we understand that the amount varies widely 

across states. As a result, we opted to include these sources 

in our analysis as sources receiving a PSD or title V permit. 

Therefore, to the extent that synthetic minor activity occurs, 

our estimate would already have included the burden for that 

activity. In fact, our estimate would have overestimated the 

burden to the extent that a permitting authority would have less 

administrative costs to issuing a “synthetic minor” permit, as 

compared to a PSD or title V permit. 

(3) Revised Burden Estimates at Statutory Thresholds 

Based on the revisions just described, we estimate that in 

all, if sources that emit GHGs become subject to PSD at the 

100/250 tpy levels, permitting authorities across the country 

would face over $1.5 billion in additional PSD permitting costs 

each year. This would represent an increase of 130 times the 

current annual burden hours under the NSR major source program 

for permitting authorities. The permitting authorities would 
139

need a total of almost 10,000 new full time employees (FTEs) to 

process PSD permits for GHG emissions. 

In addition, we estimate that in all, if sources that emit 

GHGs become subject to title V at the 100 tpy level, permitting 

authorities across the country would incur about 1.4 billion 

additional work hours, which would cost $63 billion. We 

estimate that most of this work would be done over a 3 year 

period, which would amount to 458 million in additional work 

hours, and $21 billion in additional costs, on an annual basis 

over that 3-year period. 

We also note that the survey of state and local permitting 

authorities described in the proposed rulemaking continues to 

shed light on the extent of the administrative burdens, 

including staffing, budget, and other associated resource needs, 

as projected by the permitting authorities. As noted 

previously, that survey concluded that application of the PSD 

requirements to GHG-emitting sources at the level of 100/250 tpy 

or more of actual emissions would, without additional FTEs, 

increase the average processing time for a PSD permit from one 

to 3 years. The survey further concluded that application of 

the title V requirements to GHG-emitting sources at the level of 

100 tpy or more of actual emissions would, without additional 

FTEs, increase the average processing time for a title V permit 

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from 6 months to 10 years. As we noted at proposal, this survey 

assumed a ten-fold increase in the number of PSD permits and a 

40-fold increase in the number of title V permits due to GHGemitting sources, but those assumptions were severely 

underestimated because based on actual emissions. At proposal, 

our calculations, which were based on potential emissions, 

indicated a 140-fold increase in PSD permits and a more than 

400-fold increase in title V permits. In this rulemaking, we 

recognize that even our estimates at proposal were severely 

underestimated. We now recognize that the number of PSD permits 

will be about twice what we estimated at proposal, and the 

average processing time for both PSD and title V permits will be 

two or three times greater than what we estimated at proposal. 

The survey of state and local permitting authorities provided 

other useful information as well, including the fact that it 

would take the permitting authorities 2 years, on average, to 

hire the staff necessary to handle a ten-fold increase in PSD 

permits and a 40-fold increase in title V permits, and that 90 

percent of their staff would need additional training in all 

aspects of permitting for GHG sources. 

(4) Revised Estimates of Administrative Burdens at Various 

Threshold Levels 

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In order to determine the appropriate PSD and title V 

applicability level for GHG sources, we not only estimated the 

burden at the statutory thresholds, as described previously, but 

we also estimated the number of sources, number of permitting 

actions, and amount of administrative burden at various 

applicability levels for both PSD and title V, based on the 

revised methodology described previously, that we used to 

estimate the administrative burdens of applying PSD and title V 

at the statutory levels. This information is summarized in 

Table VI-1, previously. Note that Table VI-1 also includes, in 

the last column, the administrative burdens, described 

previously, associated with the 100/250 tpy thresholds.

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Table V-1. Coverage and Burden Information

Current 

Program1

“Anyway” 

Source 

Approach 

75k Major 

Mod.

100k 

Major 

Source 

100k 

Major 

Mod. 

100k 

Major 

Source 

75k 

Major 

Mod.

100k Major 

Source 

50k Major 

Mod.

50k Major 

Source 

50k Major 

Mod.

25k Major 

Source 

25k Major 

Mod.

100/2

Major

100 Mo

Number of Major Sources

15,000 15,000 15,550 15,550 15,550 18,500 22,500 6,118,2

Number of Newly Major GHG Sources

N/A 0 550 550 550 3,500 7,500 6,105,9

Number of PSD New ConstructionActions

240 240 242 242 242 243 250 19,889 

Number of PSD ModificationActions at Covered major sources 

448 448 468 1,363 2,257 2,354 9,645 62,284 

Permitting Authority Cost to Run PSD programs 

$12M/yr. $15M/yr. $15M/yr. $36M/yr. $57M/yr. $59M/yr. $229M/yr. $1.5B/y

Permitting Authority Work Hours to Run PSD programs2

150,795 185,195 192,055 461,450 730,544 764,781 2.97 M 19.7 M 
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Permitting Authority Cost to Run Title V Programs 

$62M/yr. $63M/yr. $67M/yr. $69M/yr. $70M/yr. $88M/yr. $126M/yr. $21 B/y

Permitting Authority Work Hours to Run Title V Programs 

1.35 M 1.38 M 1.46 M 1.49 M 1.53 M 1.92 M 2.74 M 460 M 

Annual Total Cost to Run PSD and Title V Programs and percentincrease in cost over current program 

$74M/yr. $78M/yr. 

5% increase (once states adopt) 

$82M/yr. 11% increase 

$105M/yr 42% increase 

$127M/yr.72% increase 

$147M/yr. 99% increase 

$355M/yr. 380% increase 

$22.5 B30,305% increas

% GHG emissions covered 

-0- 65% 67% 67% 67% 70% 75% 78% 

Notes: (1) As explained in the preamble, "current program" figures for PSD permits also reflect NSR permits in nonattainment areas that we assume include a PSD component for at least one pollutant. (2) Number of FTEs may be calculated as work hours divided by 2,00hours.
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As described in the TSD, we considered several different 

major source/major modification threshold combinations. We 

chose the combinations to reflect representative, incremental 

steps along the possible range. Because it is time- and 

resource- intensive to develop estimates for a given step, we 

chose intervals that best reflect representative points within 

the range, given those time and resource constraints. Here, we 

discuss key observations about some of the combinations that we 

assessed. As the table indicates, under the current PSD and 

title V programs, approximately 15,000 sources qualify as major 

PSD sources for at least one pollutant and therefore meet the 

applicability thresholds. Of these, approximately 668 sources 

are subject to PSD requirements each year for at least one 

pollutant -- 240 because they undertake new construction, and 

448 because they undertake modifications. The permitting 

authorities’ administrative burdens for the NSR program are 

153,795 work hours, and $12 million. For the title V program, 

the 15,000 sources are, for the most part already permitted, and 

therefore need revised permits as required and renewal permits 

on a 5-year schedule. The permitting authorities’ title V 

administrative burdens on an annual basis are 1,349,659 work 

hours and $62 million. 

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The first threshold Table 1 describes – and which, as 

discussed later, we are adopting for Step 1 – is the “anyway” 

source approach. Under this approach, (i) PSD applies to the 

GHG emissions from projects that are subject to PSD anyway as 

new sources or major modifications due to their emissions of 

non-GHG pollutants and that result in an increase (or, in the 

case of modifications, a net increase) of at least 75,000 tpy 

CO2e; and (ii) title V applies to what we will call “anyway” 

title V sources, that is, sources that are subject to title V 

anyway due to their emissions of non-GHG pollutants. Under this 

approach, the number of sources subject to PSD each year – 

including new construction and modifications -- is the same as 

under the current program, but the permitting authorities will 

need to address GHG emissions as part of those permitting 

actions each year and, to do so, will require, each year, 34,400 

additional workload hours costing an additional $3 million. For 

title V, we estimate that the number of title V sources that 

require permitting actions will, on average, be the same each 

year, but permitting authorities will need to address GHG 

requirements for some of them; as a result, permitting 

authorities will need, each year, 27,468 additional work hours 

costing $1 million in additional funding. 

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 Another threshold described in Table VI-1 is the one we are 

adopting under Step 2, as described later, under which (i) 

sources will be subject to PSD on account of their GHG emissions 

if they newly construct and emit at least 100,000 tpy CO2e, or if 

they are existing sources that emit at least 100,000 tpy CO2e of 

GHGs and make a modification that results in a net emissions 

increase of at least 75,000 tpy CO2e; and (ii) existing sources 

will be subject to title V due to their GHG emissions if they 

emit 100,000 tpy CO2e in GHG emissions. Under this approach, 

which we will call the 100,000/75,000 approach, we estimate that 

each year, the permitting authorities will need to issue GHG 

permits to two additional sources that newly construct and 915 

that undertake modifications above current permitting levels. 

Doing so will require 310,655 additional workload hours costing 

an additional $24 million, compared to the current program. For 

title V, an additional 180 sources will require new title V 

permits each year, and the permitting authorities’ associated 

costs will be 160,572 work hours and $7 million more than the 

current program. 

The last approach we will describe here may be called the 

50,000/50,000 approach, which, as discussed later, we adopt as 

the floor for thresholds during the first 6 years after 

promulgation. Under this approach, (i) sources will be subject 

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to PSD on account of their GHG emissions if they newly construct 

and emit at least 50,000 tpy CO2e, or if they are existing 

sources that emit at least 50,000 tpy CO2e of GHGs and make a 

modification that results in a net emissions increase of at 

least 50,000 tpy CO2e; and (ii) existing sources will be subject 

to title V on account of their GHG emissions if they emit 50,000 

tpy CO2e in GHG emissions. Under this approach, each year, the 

permitting authorities will need to issue GHG permits to 3 

additional sources that newly construct and 1,900 that undertake 

modifications above current permitting levels. Doing so will 

require 613,986 additional workload hours costing $47 million, 

compared to the current program. For title V, an additional 

1,189 sources will require new title V permits each year and the 

permitting authorities’ associated costs will be 568,017 work 

hours and $26 million more than the current program. 

We present the remaining entries in the table to illustrate 

how the cost and burden estimates vary with increasing or 

decreasing thresholds relative to those selected in this rule. 

These variations are important in understanding how alternative 

thresholds would compare to the ones selected. We also include 

entries reflecting the baseline (current program without GHG 

permitting) and the burdens if we immediately implemented the 
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full statutory thresholds on January 2, 2011, without tailoring 

or streamlining. 

3. Legal Doctrines: “Absurd Results,” “Administrative 

Necessity,” and “Step-at-a-Time” Legal Doctrines

a. Introduction and Summary

Having described the factual underpinnings of our action, 

which are the costs to sources and administrative burdens to 

permitting authorities, we now describe the legal underpinnings. 

They involve the framework for analyzing agency-administered 

statutes, as established by the U.S. Supreme Court in Chevron 

U.S.A. Inc. v. NRDC, 467 U.S. 837, 842-43 (1984). In this case,

Chevron framework must take account the “absurd results,” 

“administrative necessity,” and “one-step-at-a-time” doctrines. 

We believe that each of these doctrines provides independent 

support for our action, but in addition, the three doctrines are 

directly intertwined and can be considered in a comprehensive 

and interconnected manner. Moreover, although the three 

doctrines pre-date the 1994 Chevron decision, in which the U.S. 

Supreme Court established the framework for construing agencyadministered statutes, each of the three doctrines fit 

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appropriately into the Chevron framework.26

To reiterate, for convenience, the statutory provisions at 

issue: Congress, through the definition of “major emitting 

facility,” applied the PSD program to include “any ... source[ 

that] emit[s], or ha[s] the potential to emit, one hundred [or, 

depending on the source category two hundred fifty] tons per 

year or more or more of any air pollutant.” CAA §§ 165(a), 

 26 Although we set out an analysis of how the three 

doctrines fit into the Chevron framework, we note that even if 

the doctrines are viewed independently of the Chevron framework, 

they support our this action. 

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169(1). In addition, Congress, through the definition of 

“modification,” applied the PSD program to include “any physical 

change in, or change in the method of operation of, a stationary 

source which increases the amount of any air pollutant emitted 

by such source or which results in the emission of any air 

pollutant not previously emitted.” CAA §§ 165(a), 169(2)(C), 

111(a)(4). Similarly, Congress, through the definition of 

“major source,” specified that the title V program includes “any 

stationary facility or source of air pollutants which directly 

emits, or has the potential to emit, one hundred tons per year 

or more of any air pollutant.” CAA §§ 502(a), 501(2)(B), 

302(j). EPA, through long-established regulatory action, in the 

case of PSD, and long-established guidance, in the case of title 

V, has interpreted these definitions narrowly so that they apply 

only with respect to air pollutants that are subject to 

regulation under the CAA. 

Applying these definitions by their terms, as interpreted 

narrowly by EPA, to greenhouse gas sources at the present time 

would mean that the PSD and title V programs would apply to an 

extraordinarily large number of small sources, the sources would 

incur unduly high compliance costs, and permitting authorities 

would face overwhelming administrative burdens. As a result, we 

decline to follow this literal reading, and instead, with this 

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action, we chart a course for tailoring the applicability 

provisions of the PSD program and the title V program by phasing 

them in over time to the prescribed extent. 

For our authority to take this action, we rely on the 

“absurd results” doctrine, which applies because applying the 

PSD and title V requirements literally (as previously narrowed 

by EPA) would not only be inconsistent with congressional intent 

concerning the applicability of the PSD and title V programs, 

but in fact would severely undermine congressional purpose for 

those programs. We also rely on the “administrative necessity” 

doctrine, which applies because construing the PSD and title V 

requirements literally (as previously narrowed by EPA) would 

render it impossible for permitting authorities to administer 

the PSD provisions. The tailoring approach we promulgate in 

this action is consistent with both doctrines. It is also 

consistent with a third doctrine, the “one-step-at-a-time” 

doctrine, which authorizes administrative agencies under certain 

circumstances to address mandates through phased action. 

 Our discussion of the legal bases for this rule is 

organized as follows: In this section V.B.3, we provide an 

overview of the three doctrines and describe how they fit into 

the Chevron framework for statutory construction. In section 

V.B.4, we discuss the PSD and title V programs, including each 
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program’s relevant statutory provisions, legislative history, 

and regulatory history. In sections V.B.5 and V.B.6 we discuss 

the “absurd results” approach for PSD and title V, respectively, 

that we are finalizing in our action. In section V.B.7., we 

discuss additional rulemaking in which we may consider exempting 

certain categories of sources from PSD and title V under the 

“absurd results” doctrine. In section V.B.8, we discuss the 

legal and policy rationale for the phase-in schedule that we are 

adopting for applying PSD and title V to GHG sources. In 

section V.B.9 we discuss the “administrative necessity” approach 

for PSD and title V, respectively. In section V.B.10, we 

discuss the third legal basis for our action, the “one step-ata-time” doctrine. 

b. The “Absurd Results” Doctrine 

Turning first to the “absurd results” doctrine, we note at 

the outset that we discussed the doctrine at length in the 

notice of proposed rulemaking, and we incorporate by reference 

that discussion, although we make some refinements to that 

discussion in this preamble. The starting point for EPA's 

interpretation of the PSD and title V applicability provisions 

and reliance on the “absurd results” doctrine is the familiar 

Chevron two-step analysis. We discuss this analysis in greater 

detail later, but in brief, in interpreting a statutory 

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provision, an agency must, under Chevron step 1, determine 

whether Congress's intent on a particular question is clear; if 

so, then the agency must follow that intent. If the intent of 

the provision is not clear, then the agency may, under step 2, 

fashion a reasonable interpretation of the provision. Chevron 

U.S.A. Inc. v. NRDC, 467 U.S. 837, 842-43 (1984). 

The courts consider the best indicator of congressional 

intent to be the plain meaning of the statute. However, the 

U.S. Supreme Court has held that the literal meaning of a 

statutory provision is not conclusive “in the ‘rare cases [in 

which] the literal application of a statute will produce a 

result demonstrably at odds with the intentions of the drafters’ 

... [in which case] the intention of the drafters, rather than the 

strict language, controls.” United States v. Ron Pair 

Enterprises, 489 U.S. 235, 242 (1989). This doctrine of 

statutory interpretation may be termed the “absurd results” 

doctrine. 

Although, as just noted, the U.S. Supreme Court has 

described the “absurd results” cases as “rare,” in that case the 

Court seemed to be referring to the small percentage of 

statutory-construction cases that are decided on the basis of 

the doctrine. The D.C. Circuit, in surveying the doctrine over 

more than a century of jurisprudence, characterized the body of 

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law in absolute numbers as comprising “legions of court 

decisions.” In re Franklyn C. Nofziger, 925 F.2d 428, 434 (D.C. 

Cir. 1991). Indeed, there are dozens of cases, dating from 

within the past several years to well into the 19th century,27 in 

which the U.S. Supreme Court has applied the “absurd results” 

doctrine to avoid the literal application of a statute, or if 

not so holding, has nevertheless clearly acknowledged the 

validity of the doctrine. Some of the more recent of these 

cases include: Logan v. United States, 552 U.S. 23, 36-37 

(2007) (“[s]tatutory terms, we have held, may be interpreted 

against their literal meaning where the words ‘could not 

conceivably have been intended to apply’ to the case at hand 

 27 For early cases in which the U.S. Supreme Court applied 

the “absurd results” doctrine, see Holy Trinity Church v. U.S., 

143 U.S. 457, 516-17 (1892) (“any alien” does not include a 

foreign pastor; Court stated, “It is a familiar rule, that a 

thing may be within the letter of the statute and yet not within 

the statute, because not within its spirit, nor within the 

intention of its makers.... If a literal construction of the 

words be absurd, the Act must be construed as to avoid the 

absurdity”); Chew Heong v. United States, 112 U.S. 536, 555 

(1884) (rejecting a literal interpretation of treaty that would 

have prevented the re-entry of a person into the U.S. upon the 

ground that he did not possess a certificate which did not exist 

prior to his departure, and which could not possibly have been 

issued); Heyenfeldt v. Daney Gold Mining Co., 93 U.S. 634, 638 

(1877) (statutory language expressly referred to past land sales 

and dispositions, “but evidently they were not employed in this 

sense, for no lands in Nevada had been sold or disposed of by 

any act of Congress,” and the language of the statute “could not 

. . . apply to past sales or dispositions, and, to have any 

effect at all, must be held to apply to the future”).

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[citation omitted]”); Nixon v. Missouri Municipal League, 541 

U.S. 125, 132-33 (2004) (“any entity” includes private but not 

public entities); Raygor v. Regents of Univ. of Minn., 534 U.S. 

533, 542-45 (2002) (“implying a narrow interpretation of ... ‘any 

claim asserted’ so as to exclude certain claims dismissed on 

Eleventh Amendment grounds”); United States v. X-Citement Video, 

Inc., 513 U.S. 64, 69 (1994) (rejecting a literal interpretation 

of the statutory term “knowingly” on grounds that Congress could 

not have intended the “positively absurd” results that some 

applications of such an interpretation would produce, “[f]or 

instance, a retail druggist who returns an uninspected roll of 

developed film to a customer “knowingly distributes” a visual 

depiction and would be criminally liable if it were later 

discovered that the visual depiction contained images of 

children engaged in sexually explicit conduct”); and Rowland v. 

Cal. Men’s Colony, 506 U.S. 194, 200 (1993) (finding that an 

artificial entity such as an association is not a “person” under 

the statute, and describing the absurdity doctrine as a “common 

mandate of statutory construction”); United States v. Ron Pair 

Enterprises, 489 U.S. 235, 242 (1989) (the plain meaning of a 

statutory provision is not conclusive “in the ‘rare cases [in 

which] the literal application of a statute will produce a 

result demonstrably at odds with the intentions of the drafters’ 

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... [in which case] the intention of the drafters, rather than the 

strict language, controls”); Green v. Bock Laundry Machine 

Company, 490 U.S. 504 (1989) (provision in Federal Rule of 

Evidence that protects “the defendant” against potentially 

prejudicial evidence, but not the plaintiff, refers to only 

criminal, and not civil, defendants); Public Citizen v. United 

States Dep’t of Justice, 491 U.S. 440, 453-54 (1989) (rejecting 

a broad, straightforward reading of the term “utilize,” on 

grounds that a literal reading would appear to require the 

absurd result that all of FACA’s restrictions apply if a 

President consults with his own political party before picking 

his Cabinet, and such a reading “was unmistakably not Congress’ 

intention”); Watt v. Alaska, 451 U.S. 259, 266 (1981) (rejecting 

reliance on plain statutory language and concluding that the 

term “minerals” in § 401(a) of the Wildlife Refuge Revenue 

Sharing Act applies only to minerals on acquired refuge lands; 

stating “[t]he circumstances of the enactment of particular 

legislation may persuade a court that Congress did not intend 

words of common meaning to have their literal effect”); Train v. 

Colorado Public Interest Research Group, Inc., 426 U.S. 1, 23-

24 (1976) (prohibition in Federal Water Pollution Control Act 

against discharging into navigable waters “pollutants,” which 

are defined to include “radioactive materials,” does not apply 
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to three specific types of radioactive materials); Jackson v. 

Lykes Bros. S.S. Co., 386 U.S. 731, 735 (1967) (refusing to 

distinguish between a longshoreman hired by “an independent 

stevedore company” and one hired by “the shipowner . . . to do 

exactly the same kind of work,” despite the clear terms of the 

Act, and stating: “[w]e cannot hold that Congress intended any 

such incongruous, absurd, and unjust result in passing this 

Act,” when the Act was “designed to provide equal justice to 

every longshoreman similarly situated”); Lynch v. Overholser,

369 U.S. 705, 710, (1962) (statutory construction is not 

confined to the “bare words of a statute”); United States v. 

Bryan, 339 U.S. 323, 338 (1950) (“Despite the fact that the 

literal language would encompass testimony elicited by the House 

Committee in its questioning of respondent relative to the 

production of the records of the association, the Court will not 

reach that result if it is contrary to the congressional intent 

and leads to absurd conclusions. And we are clearly of the 

opinion that the congressional purpose would be frustrated if 

the words, “in any criminal proceeding,” were read to include a 

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reference, in section 

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prosecution for willful default under R.S. § 102.”).28

 The D.C. Circuit has also handed down numerous decisions 

that applied the absurd results doctrine to avoid a literal 

interpretation or application of statutory provisions or that 

have acknowledged the doctrine. Some of the most recent ones 

include: Arkansas Dairy Cooperative Ass’n, Inc., v. U.S. Dep’t 

of Agriculture, 573 F.3d 815 (D.C. Cir. 2009) (rejecting the 

canon of construction that presumes that Congress is aware of 

existing law pertinent to the legislation that it enacts, when 

in this case, the presumption that Congress was aware of the 

Departments definition of “hearing” would lead to “the absurd 

 28 For other U.S. Supreme Court cases, see Utah Junk Co. v. 

Porter, 328 U.S. 39, 44 (1946) (“literalness may strangle 

meaning”); Markham v. Cabell, 326 U.S. 404, 409 (1945) (“The 

policy as well as the letter of the law is a guide to 

decision.”); United States v. American Trucking Associations, 

Inc. 310 U.S. 534 (1940) (the term “employees” in the Federal 

Motor Carrier Act, is limited to employees whose activities 

affect safety); C.V. Sorrels v. U.S., 287 U.S. 435, 446-49 

(1932) (provisions of National Prohibition Act that criminalize 

possessing and selling liquor do not apply if defendant is 

entrapped; Court declines to apply the “letter of the statute” 

because doing so “in the circumstances under consideration is 

foreign to its purpose”); United States v. Katz, 271 U.S. 354, 

362 (1926) (holding that the statutory words “no person” refer 

only to persons authorized under other provisions of the Act to 

traffic alcohol, thus rejecting a literal application of general 

terms descriptive of a class of persons made subject to a 

criminal statute); Hawaii v. Mankichi, 190 U.S. 197, 212-14 

(1903) (refusing to adopt a literal application of the “Newlands 

resolution” which would have entitled every criminal in the 

State of Hawaii convicted of an offense between 1898 – 1900 to 

be set at large, as “surely such a result could not have been 

within the contemplation of Congress”). 

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result that Congress intended to impose a requirement with which 

the Secretary could not comply;” stating: “Courts, ‘in 

interpreting the words of a statute, [have] some scope for 

adopting a restricted rather than a literal or usual meaning of 

its words where acceptance of that meaning would lead to absurd 

results . . . or would thwart the obvious purpose of the statute 

. . . .’” (quoting In re Trans Alaska Pipeline Rate Cases, 436 

U.S. 631, (1978)); Buffalo Crushed Stone, Inc. v. Surface 

Transportation Board, 194 F.3d 125, 129-30 (D.C. Cir. 1999) 

(regulation of Surface Transportation Board providing that if a 

notice of exemption “contains false or misleading information, 

the use of the exemption is void ab initio” does not apply to a 

notice containing false information when declaring the notice 

void ab initio would undermine the goals of the governing 

statute; a conflict between the “literal application of 

statutory language” and maintaining the integrity of the 

regulatory scheme should be resolved by construing the text in 

accordance with its purpose); Mova Pharm. Corp. v. Shalala, 140 

F.3d 1060, 1068 (D.C. Cir. 1998); U.S. v. Stewart, 104 F.3d 

1377, 1388 (D.C. Cir. 1997); Environmental Defense Fund v. EPA, 

82 F.3d 451, 468-69 (D.C. Cir. 1996) (although Act requires 

that a federal action conform to the SIP that is currently in 

place, EPA may instead require conformity to a revised 

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plan
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implementation plan that state commits to develop; “[t]his is 

one of those rare cases * ** [that] requires a more flexible, 

purpose-oriented interpretation if we are to avoid ‘absurd or 

futile results.’”); American Water Works Ass’n v. EPA, 40 F.3d 

1266, 1271 (D.C. Cir. 1994) (holding that EPA’s interpretation 

of the term “feasible” so as to require a treatment technique 

instead of an MCL for lead is reasonable; the court stated: 

“Indeed, where a literal reading of a statutory term would lead 

to absurd results, the term simply ‘has no plain meaning . . . 

and is the proper subject of construction by the EPA and the 

courts.’ If the meaning of ‘feasible’ suggested by the NRDC is 

indeed its plain meaning, then this is such a case; for it could 

lead to a result squarely at odds with the purpose of the Safe 

Drinking Water Act.” (quoting Chem. Mfrs. Ass’n v. Natural Res. 

Def. Council, Inc., 470 U.S. 116, 126 (1985)) (citation 

omitted); In re Nofziger, 925 F.2d 428, 434-35 (D.C. Cir. 1991) 

(provision authorizing payment of attorney fees to the subject 

of an investigation conducted by an independent counsel of the 

Department of Justice only if “no indictment is brought” against 

such individual does not preclude payment of attorney fees when 

an indictment is brought but is determined to be invalid). 

c. The “Administrative Necessity” Doctrine

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“administrative necessity” 

doctrine¶
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In the proposed rulemaking, we also described in 

detail the “administrative necessity” doctrine, 74 FR 55311 

col. 3 to 55318 col. 3, and we incorporate that discussion 

by reference into this notice. Under this doctrine, if a 

statutory provision, however clear on its face, is 

impossible for the agency to administer, then the agency is 

not required to follow the literal requirements, and 

instead, the agency may adjust the requirements in as 

refined a manner as possible to assure that the 

requirements are administrable, while still achieving 

Congress's overall intent. The D.C. Circuit set out the 

doctrine of "administrative necessity" in a line of cases 

that most prominently includes Alabama Power v. Costle, 636 

F.2d 323 (D.C. Cir. 1980). The Court cited the doctrine 

most recently in New York v. EPA, 443 F.3d 880, 884, 888 

(D.C. Cir. 2006). 

In addition, as we stated in the proposed rulemaking, “We 

believe that the administrative necessity case law establishes a 

three-step process under which an administrative agency may, 

under the appropriate circumstances, in effect revise statutory 

requirements that the agency demonstrates are impossible to 

administer so that they are administrable.” 74 FR 55315 col. 1. 

Specifically: 
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[T]he three steps are as follows: When an agency 

has identified what it believes may be insurmountable 

burdens in administering a statutory requirement, the 

first step the agency must take is to evaluate how it 

could streamline administration as much as possible, 

while remaining within the confines of the statutory 

requirements. The second step is that the agency must 

determine whether it can justifiably conclude that 

even after whatever streamlining of administration of 

statutory requirements (consistent with those 

statutory requirements) it conducts, the remaining 

administrative tasks are impossible for the agency 

because they are beyond its resources, e.g., beyond 

the capacities of its personnel and funding. If the 

agency concludes with justification that it would be 

impossible to administer the statutory requirements, 

as streamlined, then the agency may take the third 

step, which is to phase in or otherwise adjust the 

requirements so that they are administrable. However, 

the agency must do so in a manner that is as refined 

as possible so that the agency may continue to 

implement as fully as possible Congressional intent. 

74 FR 55315 cols. 1-2. 

 It should also be noted that we believe the administrative 

burdens encountered by the state and local permitting 

authorities are fully relevant under the “administrative 

necessity” doctrine. Although the caselaw that discusses the 

doctrine focuses on federal agencies, see 74 FR 55312-14, under 

the CAA, state and local agencies are EPA’s partners in 

implementing provisions of the CAA, and have primary 

responsibility for implementing the PSD program. They generally 

adopt EPA’s PSD requirements in their SIPs, as required under 

CAA section 110(a)(2)(C); and they generally adopt EPA’s title V 

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They 
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requirements in their title V programs, as required under CAA 

section 502(d). They issue the PSD and title V permits and are 

responsible in the first instance for enforcing the terms of the 

permits. In all these respects, the law that the state and 

local permitting authorities administer is both federal and 

state law. Under certain circumstances, EPA may become 

responsible for permit issuance and enforcement in the first 

instance, but even then, EPA may, and frequently has, delegated 

those duties to a state, in which case, the state implements 

federal law directly. Thus, although the PSD and title V 

programs are federal requirements, for the most part, it is the 

states that implement those programs. For this reason, the 

administrative burdens that the states face in implementing the 

programs are relevant in determining the applicability of the 

“administrative necessity” doctrine. 

d. “One-Step-at-a-Time” Doctrine

In addition to the “absurd results” and “administrative 

necessity” doctrines, another judicial doctrine supports at 

least part of EPA’s Tailoring Rule, and that is the doctrine 

that agencies may implement statutory mandates one step at a 

time, which we will call the “one-step-at-a-time” doctrine. In 

the notice of proposed rulemaking, we also described this 

doctrine and recent case law applied it. 74 FR 55,319 col. 1-3. 

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As we noted, that the U.S. Supreme Court recently described the 

doctrine in Massachusetts v. EPA, 549 U.S. 497, 524 (2007), as 

follows: “Agencies, like legislatures, do not generally resolve 

massive problems in one fell regulatory swoop;” and instead they 

may permissibly implement such regulatory programs over time, 

“refining their preferred approach as circumstances change and 

as they develop a more nuanced understanding of how best to 

proceed.” We assume familiarity with our discussion in the 

proposal, but we expand upon it here to review the caselaw in 

greater detail and to highlight certain components of the 

doctrine that are particularly relevant to the Tailoring Rule.

The roots of the doctrine go back at least to the D.C. Circuit’s 

1979 decision in United States Brewers Association, Inc. v. EPA, 

600 F.2d 974 (D.C. Cir. 1979). There, the Court considered a 

challenge to EPA’s guidelines for managing beverage containers, 

which EPA was required to promulgate under the Resource 

Conservation and Recovery Act of 1976 (RCRA). RCRA gave EPA one 

year to promulgate the guidelines. EPA promulgated a partial 

set of guidelines, started two others, and was challenged before 

the year was out by petitioners who objected to the initial 

guideline, saying it fell short of the statutory mandate. The 

Court upheld the initial guideline, stating: “Under these 

circumstances we think the question of whether the Agency has 

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recent D.C. Circuit cases 

that upheld 
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fully satisfied the mandate of the statute is not fit for 

judicial review at this time, when the Agency, still well within 

the one-year period granted by statute, is deeply involved in 

the process of formulating rules designed to carry out the 

congressional mandate. The Agency might properly take one step 

at a time.” States Brewers Association, Inc. v. EPA, 600 F.2d 

at 982. 

The Court addressed the doctrine at greater length in 

National Association of Broadcasters v. FCC, 740 F.2d 1190, 

1209-14 (D.C. Cir. 1984). There, the Court noted that under 

certain statutory schemes, step-by-step agency action might not 

be authorized; but the Court emphasized that when it is 

authorized, it may offer significant benefits; and the Court 

went on to delineate some of the circumstances under which its 

use is justified. In that case, the Court held that FCC acted 

reasonably in making a spectrum allocation decision that granted 

direct broadcast satellite service priority use of a GHG band in 

five-years time, and -- although acknowledging that fixed 

service users that were, at that time, using that band, would 

have to relocate to other bands – in postponing the details of 

the fixed service relocation to future proceedings. The Court 

described in some detail “[t]he circumstances under which ... [an]
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agency may defer resolution of problems raised in a rulemaking,” 

as follows: 

The requisite judgment is in essence a pragmatic one. In 

an ideal world, of course, agencies would act only after 

comprehensive consideration of how all available 

alternatives comported with a well-defined policymaking 

objective, and in some circumstances, statutes indeed 

mandate that agencies proceed by only such a course.... But 

administrative action generally occurs against a shifting 

background in which facts, predictions, and policies are in 

flux and in which an agency would be paralyzed if all the 

necessary answers had to be in before any action at all 

could be taken.... We have therefore recognized the 

reasonableness of [an agency’s] decision to engage in 

incremental rulemaking and to defer resolution of issues 

raised in a rulemaking even when those issues are ‘related’ 

to the main ones being considered.... At the same time, [an 

agency] cannot ‘restructure [an] entire industry on a 

piecemeal basis’ through a rule that utterly fails to 

consider how the likely future resolution of crucial issues 

will affect the rule’s rationale....

Drawing a line between the permissible and the 

impermissible in this area will generally raise two 

questions. First the agency will likely have made some 

estimation, based upon evolving economic and technological 

conditions, as to the nature and magnitude of the problem 

it will have to confront when it comes to resolve the 

postponed issue. With regard to this aspect of the 

agency’s decision, as long as the agency’s predictions 

about the course of future events are plausible and flow 

from the factual record compiled, a reviewing court should 

accept the agency’s estimation.... Second, once the nature 

and magnitude of the unresolved issue is determined, the 

relevant question is whether it was reasonable, in the 

context of the decisions made in the proceeding under 

review, for the agency to have deferred the issue to the 

future. With respect to that question, postponement will 

be most easily justified when an agency acts against a 

background of rapid technical and social change and when 

the agency’s initial decision as a practical matter is 

reversible should the future proceedings yield drastically 

unexpected results. In contrast, an incremental approach 
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to agency decision making is least justified when small 

errors in predictive judgments can have catastrophic 

effects on the public welfare or when future proceedings 

are likely to be systematically defective in taking into 

account certain relevant interests.... 

740 F.2d at 1210-11 (citations omitted).

In City of Las Vegas v. Lujan, 891 F.2d 927 (D.C. Cir. 

1989), the Court suggested that one component of its upholding 

partial agency compliance with a statutory directive is evidence 

that the agency was on track for full compliance. There, the 

Court upheld the Department of Interior’s decision to list the 

population of desert tortoises living north and west of the 

Colorado River (the “Mojave” population) as endangered species, 

but not the nearby population living south and east of the river 

(the “Sonoran” population). The agency explained that the 

Mojave population faced certain threats that the Sonoran 

population did not, and the Court found nothing to fault in that 

reasoning. The Court added: “Since agencies have great 

discretion to treat a problem partially, we would not strike 

down the listing if it were a first step toward a complete 

solution, even if we thought it ‘should’ have covered both the 

Mojave and Sonoran populations.” City of Las Vegas v. Lujan, 

891 F.2d 927, 935 (D.C. Cir. 1989) (footnote omitted). 

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partial

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In Grand Canyon Air Tour Coalition v. F.A.A., 154 F.3d 455 

(D.C. Cir. 1998), the D.C. Circuit added another component to 

the “one-step-at-a-time” doctrine: While reiterating that 

“ordinarily, agencies have wide latitude to attack a regulatory 

problem in phases and that a phased attack often has substantial 

benefits,” id. at 471, the Court went on to uphold partial 

agency action even when that action was long-delayed. There, 

the relevant statute was the Overflights Act, which required the 

Federal Aviation Administration (FAA) to reduce aircraft noise 

from sightseeing tours in Grand Canyon National Park, and 

established the goal of “substantial restoration of natural 

quiet and experience of the park.” The statute required the 

agency to develop a plan to implement the statutory requirements 

within 120 days after enactment, and report to Congress within 2

years after the date of the plan as to the plan’s success. In 

fact, the FAA did not develop, through rulemaking, a plan until 

ten years after enactment, and when it did, it acknowledged that 

the plan was only a partial one, and that it would need two more 

rules and another ten years to meet the statutory goal of 

substantial restoration. Although recognizing that the 

Overflights Act did not establish an explicit timetable for 

meeting the statutory goal, the Court stated that “[t]he 

language of the Overflights Act does manifest a congressional 

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partial agency plan 

promulgated 10

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concern with expeditious agency action,” and described the 

agency’s action variously as “tardy,” “undeniably slow,” and 

“slow and faltering.” Id. at 476-77. Even so, the Court upheld 

the FAA’s action against different challenges from appellants 

and intervenors that (i) the agency acted unreasonably in not 

promulgating a complete plan to meet the statutory goal, instead 

of promulgating just the first step; and (ii) the agency acted 

unreasonably in not waiting until it had a complete plan before 

promulgating the first step. The Court stated: “We agree that 

it would be arbitrary and capricious for an agency simply to 

thumb its nose at Congress and say – without any explanation –

that it simply does not intend to achieve a congressional goal 

on any timetable at all....,” but went on to emphasize that the 

FAA’s rule was the first of three that the agency assured would 

achieve the statutory goal. The Court cited City of Las Vegas 

v. Lujan, discussed previously, for the proposition that “a 

court will not strike down agency action ‘if it were a first 

step toward a complete solution.’” Grand Canyon Air Tour 

Coalition v. F.A.A., 154 F.3d 455, 477-78 (D.C. Cir. 1998).29

 29 For other cases, see Arizona Public Service Co. v. EPA, 

562 F.3d 1116, 1125-26 (10th Cir. 2009); General American 

Transp. Corp. v. ICC, 872 F.2d 1048, 1058 (D.C. Cir. 

PLACEHOLDER); Hazardous Waste Treatment Council v. EPA, 861 F.2d 

277, 287 (D.C. Cir. 1988); Western Union International, Inc. v. 

FCC, 725 Fl2d 732, 754 (D.C. Cir. 1984).
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e. Consistency of Doctrines with Chevron Framework 

Although the “absurd results,” “administrative necessity,” 

and “one-step-at-a-time” doctrines pre-date the Chevron two-step 

analysis for construing statutes that Congress has authorized an 

agency to administer, we believe that the doctrines can be 

considered very much a part of that analysis. Under Chevron

step 1, an agency must determine whether “Congress has directly 

spoken to the precise question at issue.” If so, “the court, as 

well as the agency, must give effect to the unambiguously 

expressed intent of Congress.” However, if “the statute is 

silent or ambiguous with respect to the specific issue, the 

question for the court is whether the agency’s answer is based 

on a permissible construction of the statute.” 

Chevron U.S.A. Inc. v. NRDC, 467 U.S. 837, 842-42 (1984). 

Thus, step 1 under Chevron calls for determining

congressional intent for the relevant statutory directive on the 

specific issue presented. To determine Congress’s intent, the 

agency must look first to the statutory terms in question, and 

generally interpret them according to their literal meaning, 

within the overall statutory context, and perhaps with reference 

to the legislative history. If the literal meaning of the 

statutory requirements is clear then, absent indications to the 

 

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contrary, the agency must take it to indicate congressional 

intent and must implement it. Even if the literal meaning of 

the statutory requirements is not clear, if the agency can 

otherwise find indications of clear congressional intent, such 

as in the legislative history, then the agency must implement 

that congressional intent. 

The D.C. Circuit has indicated that the “absurd results” 

doctrine fits into the Chevron step 1 analysis in the following 

way: Recall that in the cases in which the courts have invoked 

this doctrine, the literal meaning of the statutory requirements 

has been clear, but has led to absurd results. This can occur 

when the literal meaning, when applied to the specific question, 

conflicts with other statutory provisions, contradicts 

congressional purpose as found in the legislative history – and, 

in particular, undermines congressional purpose – or otherwise 

produces results so illogical or otherwise contrary to sensible 

public policy as to be beyond anything Congress would reasonably 

have intended. See United States v. Ron Pair Enterprises, 489 

U.S. 235, 242-43 (1989); Griffin v. Oceanic Contractors, Inc., 

458 U.S. 564, 571 (1982).

Under these circumstances, the agency must not take 

the literal meaning to indicate congressional intent. As 

the D.C. Circuit has explained, “where a literal reading of 

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a statutory term would lead to absurd results, the term 

‘simply has no plain meaning . . . and is the proper 

subject of construction by the EPA and the court.’” 

American Water Works Assn v. EPA, 40 F.3d 1266, 1271 (D.C. 

Cir. 1994) (quoting Chemical Manufacturers’ Association v. 

NRDC, 470 U.S. 116, 126 (1985)). Under these 

circumstances, if the agency can find other indications of 

clear congressional intent, then the agency must implement 

that intent. See United States v. Ron Pair Enterprises, 

489 U.S. 235, 242-43 (1989). This may mean implementing 

the statutory terms, albeit not in accordance with their 

literal meaning, but in a way that achieves a result that 

is as close as possible to congressional intent. As the 

D.C. Circuit said in Mova Pharm. Corp. v. Shalala, 140 F.3d 

1060 (D.C. Cir. 1998): 

The rule that statutes are to be read to 

avoid absurd results allows an agency to 

establish that seemingly clear statutory language 

does not reflect the ‘unambiguously expressed 

intent of Congress,’ ... and thus to overcome the 

first step of the Chevron analysis. But the 

agency does not thereby obtain a license to 

rewrite the statute. When the agency concludes 

that a literal reading of a statute would thwart 

the purposes of Congress, it may deviate no 

further from the statute than is needed to 

protect congressional intent. . . . [T]he 

agency might be able to show that there are 

multiple ways of avoiding a statutory anomaly, 

all equally consistent with the intentions of the 

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statute’s drafters . . . . In such a case, we 

would move to the second stage of the Chevron

analysis, and ask whether the agency’s choice 

between these options was ‘based on a permissible 

construction of the statute.’ Otherwise, 

however, our review of the agency’s deviation 

from the statutory text will occur under the 

first step of the Chevron analysis, in which we 

do not defer to the agency’s interpretation of 

the statute.” 

Id. at 1068 (quoting Chevron U.S.A. Inc. v. NRDC, 467 U.S. 

837, 842, 843 (1984) (citations omitted)). 

The “administrative necessity” doctrine is not as well 

developed as the “absurd results” doctrine, so that the courts 

have not had occasion to explicitly describe how the doctrine 

fits into the Chevron analytical framework. However, we think 

that a reasonable approach, in line with the D.C. Circuit’s 

approach to the “absurd results” doctrine as just described, is 

as follows: Recall that under the “administrative necessity” 

doctrine, an agency is not required to implement a statutory 

provision in accordance with the literal requirements when doing 

so would be impossible, but the agency must nevertheless 

implement the provision as fully as possible. Placed in the 

context of the Chevron framework, we think that that the 

“administrative necessity” doctrine is based on the premise that 

inherent in the statutory design is the presumption that 

Congress does not intend to impose an impossible burden on an 

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administrative agency. See Alabama Power v. Costle, 636 F.2d 

323, 357 (D.C. Cir. 1980) (describing the “administrative 

necessity” approach as one of the “limited grounds for the 

creation of exemptions [that] are inherent in the administrative 

process, and their unavailability under a statutory scheme 

should not be presumed, save in the face of the most unambiguous 

demonstration of congressional intent to foreclose them”). 

Therefore, if the literal meaning of a statutory directive 

would impose on an agency an impossible administrative burden, 

then that literal meaning should not be considered to be 

indicative of congressional intent. Rather, congressional 

intent should be considered to be to achieve as much of the 

statutory directive as possible. As a result, the agency must 

adopt an approach that implements the statutory directive as 

fully as possible. This is consistent with the D.C. Circuit’s 

holding in Mova Pharm. Corp that if congressional intent is 

clear, but the plain meaning of a statute does not express that 

intent, then the agency must, under Chevron step 1, select an 

interpretation that most closely approximates congressional 

intent. Mova Pharm. Corp, 140 F.3d at 1068.30

 30 We recognize that we described the relationship between 

the Chevron framework and the “administrative necessity” 

doctrine somewhat differently in the proposal, 74 FR 55,312/1-2, 

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directive should not be 

considered to have 

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that plain

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 The “one-step-at-a-time” doctrine fits into the Chevron

framework in much the same manner that the “administrative 

necessity” doctrine does. That is, inherent in the statutory 

design is the presumption that Congress intended an agency, 

under certain circumstances, to implement the statutory 

requirements in a one-step-at-a-time fashion, as long as the 

agency stays on a path towards full implementation. 

Under all of the circumstances described previously, 

congressional intent is clear – whether it is indicated by the 

plain language or otherwise – and as a result, the agency must 

follow that intent under Chevron step 1. On the other hand, the 

agency may determine that congressional intent on the specific 

issue is not clear. In these cases, the agencies should proceed 

to Chevron step 2 and select an interpretation or an application 

that is a permissible construction of the statute. This 

situation generally occurs when the statutory provisions are 

ambiguous or silent as to the specific issue, and there are no 

other indications of clear congressional intent. In addition, 

in some cases in which the literal meaning of the statutory 

provision, when applied to the specific question, leads to an 

absurd result – and, therefore, the statutory provision should 

 

and that, after further analysis, we are refining our view of 

that relationship as described previously.

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be considered not to have a plain meaning – there may be no 

other indications of clear congressional intent. Under all 

these circumstances, the agency is authorized, under Chevron

step 2, to develop and implement a construction of the statute 

that the courts will uphold as long as it is reasonable. 

As noted above, the D.C. Circuit, has pointed out that this 

situation may also occur when the literal language leads to an 

absurd result, and, in attempting to implement congressional 

intent, the agency is “able to show that there are multiple ways 

of avoiding a statutory anomaly, all equally consistent with the 

intentions of the statute’s drafters . . . . In such a case, we 

would move to the second stage of the Chevron analysis, and ask 

whether the agency’s choice between these options was ‘based on 

a permissible construction of the statute.’” Mova Pharm. Corp,

140 F.3d at 1068. As the U.S. Supreme Court has recently said, 

although in a context different than “absurd results,” “ In the 

end, the interpretation applied by EPA "governs if it is a 

reasonable interpretation of the statute -- not necessarily the 

only possible . . . interpretation, nor even the interpretation 

deemed most reasonable by the courts." Entergy Corp. v. 

Riverkeeper, Inc., 129 S.Ct. 1498. 1505 (2009). 

There is another aspect of the “administrative necessity” 

doctrine worth noting: The doctrine applies when (i) a literal 

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application of the statutory directive to the case at hand is 

impossible for the agency to administer; and (ii) even so, 

either Congress clearly intended the statutory directive to 

apply to the case at hand or, if Congress did not clearly intend 

that, then the agency reasonably construes the statute to apply 

the statutory directive to the case at hand. In contrast, if 

Congress did not intend the statutory directive to apply to the 

case at hand, or if congressional intent is uncertain and the 

agency considers another approach to be reasonable, then the 

“administrative necessity” doctrine would not apply. As a 

result, the agency would not be required to implement the 

statutory directive to the case at hand at all, much less in a 

more administrable fashion.

f. Interconnectedness of the Legal Doctrines 

Although we believe that each of the “absurd results,” 

“administrative necessity,” and “one-step-at-a-time” doctrine 

provides independent support for our action, we also believe 

that in this case, the three doctrines are intertwined and form 

a comprehensive basis for EPA’s tailoring approach. As just 

discussed, each of the three doctrines is tied into the Chevron

analytical framework because each is designed to give effect to 

underlying intent. As discussed previously, each of the three 

doctrines comes into play in this case because a literal reading 

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of the PSD and title V applicability provisions results in 

insurmountable administrative burdens. Those administrative 

burdens -- along with the undue costs to sources -- must be 

considered “absurd results” that would undermine congressional 

purpose for the PSD and title V programs. Under the “absurd 

results” doctrine, EPA is authorized not to implement the 

applicability provisions literally – that is, not to implement 

them as applying on the January 2, 2011 date that PSD and title 

V are triggered to all GHG sources at or above the statutory 

thresholds -- but instead to tailor them in a manner consistent 

with congressional intent. That means applying the PSD 

requirements, through a phase-in approach, to as many sources as 

possible and as quickly as possible, starting with the largest 

sources, all as EPA does with this Tailoring Rule.31 By the same 

token, the insurmountable administrative burdens bring into play 

the “administrative necessity” doctrine, under which EPA is, 

again, authorized not to implement the applicability provisions 

literally, but instead to apply them in a manner consistent with 

administrative resources. This also means phasing them in 

through the approach in the Tailoring Rule. Finally, the “one-

 31 As discussed later, EPA may, in future rulemaking, make a 

final determination that under the “absurd results” doctrine, 

Congress did not intend for EPA to apply PSD to very small 

sources, that is, those, the emissions from which, are at or 

near the 100/250 tpy statutory levels.

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tailoring 
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step-at-a-time” doctrine, which authorizes incremental action by 

agencies to implement statutory requirements under certain 

circumstances, provides further support for the phased tailoring 

approach in the Tailoring Rule. 

g. Application of Chevron Approach

The Chevron analytical approach, and the three legal 

doctrines at issue here, apply to this action in the following 

manner: To reiterate, for convenience, the statutory provisions 

at issue: Congress, through the definition of “major emitting 

facility,” applied the PSD program to include (i) “any ... 

stationary sources of air pollutants which emit or have the 

potential to emit, one hundred [or, depending on the source 

category, two hundred fifty] tons per year or more of any air 

pollutant,” CAA §§ 165(a), 169(1); and (ii) and such sources 

that undertake a physical or operational change that “increases 

the amount of any air pollutant emitted” by such sources, CAA §§ 

165(a), 169(2)(C), 111(a)(4).32 Similarly, Congress, through the 

definition of “major source,” specified that the title V program 

 32 A physical or operational change is treated as a 

“modification” that is subject to PSD if it either “increases 

the amount of any air pollutant emitted” by the source or 

“results in the emission of any air pollutant not previously 

emitted.” For convenience, unless otherwise indicated, when we 

refer to changes that “increase[] the amount of any air 

pollutant emitted,” we mean both to those types of changes and 

changes that “result[] in the emission of any air pollutant not 

previously emitted.”

Deleted: f. 

Deleted: approach¶

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more or more of any air 

pollutant.... 

Deleted: ] any other 

Deleted: with the potential 

to emit

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Deleted: ).
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includes “any stationary facility or source of air pollutants 

which directly emits, or has the potential to emit, one hundred 

tons per year or more of any air pollutant.” CAA §§ 502(a), 

501(2)(B), 302(j). EPA, through long-established regulatory 

action, in the case of PSD, and long-established interpretation, 

in the case of title V, has interpreted these definitions so 

that they apply only with respect to air pollutants that are 

subject to regulation under the CAA. 

For each of these applicability provisions, the approach 

under Chevron is as follows: Under Chevron step 1, we must 

determine whether Congress expressed an intention on the 

specific question, which is whether the PSD or title V 

applicability provisions apply to GHG sources. Said 

differently, the specific question is whether, in the case of 

PSD, Congress intended that the definition of major emitting 

facility applies to all GHG sources that emit at least 100 or 

250 tpy or GHGs and to all physical or operational changes by 

major emitting facilities that “increase[] the amount” of GHGs; 

and, in the case of title V, whether the definition of “major 

source” applies to all GHG sources that emit at least 100 tpy 

GHGs. 

To determine intent, we must first examine the terms of the 

statute in light of their literal meaning. Here, the literal

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reading of each provision covers GHG sources. For PSD, a GHG 

source that emits at least 100 or 250 tpy GHGs literally

qualifies as “stationary source[] of air pollutants which 

emit[s] or ha[s] the potential to emit, one hundred [or two 

hundred fifty] tons per year or more of any air pollutant 

[subject to regulation under the CAA].” CAA § 169(1). For 

modifications, a physical or operational change that increases 

the amount of GHG emissions qualifies as a “modification” 

because it “increases the amount of any air pollutant emitted” 

by the source. Similarly, for title V, a GHG source that emits 

at least 100 tpy GHGs literally qualifies as “any stationary 

facility or source of air pollutants which directly emits, or 

has the potential to emit, one hundred tons per year or more of 

any air pollutant [subject to regulation under the CAA].” CAA 

§§ 502(a), 501(2)(B), 302(j). 

However, applying each definition in accordance with its 

literal meaning to GHG sources at the specified levels of 

emissions and at the present time would create undue costs for 

sources and impossible administrative burdens for permitting 

authorities; and these results are not consistent with other 

provisions of the PSD and title V requirements, are inconsistent 

with – and, indeed, undermine – congressional purposes for the 

PSD and title V provisions. Accordingly, under the “absurd 

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Deleted: any ... other 

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that

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create impossible 

administrative burdens for 

the permitting authorities
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results” doctrine, neither the PSD nor the title V definitions 

of “major emitting facility” or “modification” and the title V 

definition of “major source,” should be not be applied literally 

to GHG sources, and therefore none should be considered to have 

a plain meaning with respect to their application to GHG 

sources. 

In parsing the provisions of each definition more closely, 

we believe that each has three terms, any one of which could be 

considered not to have its literal meaning, in this respect. 

Specifically, each provision includes (i) the term “any ... 

source,” or “a stationary source,” and that term could be 

considered not to refer literally to all of the GHG sources; 

(ii) either the term “two hundred fifty tons per year” or “100 

tons per year,” or the term “increases the amount,” and those 

terms could be considered not to refer literally to the tonnage 

amount of emissions from all of the GHG sources; and (iii) the 

term “any air pollutant33 [subject to regulation under the CAA],” 

and that term could be considered not to refer literally to the 

emissions from all of the GHG sources. As long as any one of 

those three terms should be considered not to have its literal

 33 As discussed elsewhere, we do not believe that this term 

is ambiguous with respect to the need to cover GHG sources under 

the PSD program, only with respect to what sources of GHG should 

be covered under the circumstances presented here.

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meaning as applied to GHG sources, then the definition as a 

whole – again, for PSD, the terms “major emitting facility” or 

“modifications,” and for title V, the term “major source” – 

cannot be considered to apply to GHG sources. Because we read 

the terms together, as integral parts of each definition as a 

whole, we do not think that the choice of which of those three 

terms within each definition cannot be considered to apply 

literally to GHG sources has substantive legal effect. In other 

words, we believe that any one of the three terms, or all three 

together as part of each definition as a whole, should be 

considered not to apply literally in the case of GHG sources. 

Having determined that each definition does not have a 

plain meaning on the specific question of whether PSD or title V 

applies to GHG sources, we must next inquire as to whether 

Congress has nevertheless expressed an intent on that question 

through other means. We discuss the statutory terms and 

legislative history of the PSD and title V provisions in more 

detail later, but for now it suffices to say that on the issue 

of whether PSD and title V apply to GHG sources, we believe that 

congressional intent is clear, and that is to apply PSD and 

title V to GHG sources generally. We believe that the broad 

phrasing of the applicability provisions evidences that intent. 

As a result, we believe that as a matter of Chevron step 1, PSD 

Deleted: term 

Deleted: believe that there 

are two possible views about 

congressional intent. The 

first is that Congress did 

express an intent, and that 

was that if a type of source 

– such as GHG sources – 

cannot be included in the 

PSD program or title V 

program in accordance with 

the literal terms of the 

applicability provisions, 

then, nevertheless, as many 

of those sources should be 

included in the 
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and title V apply to GHG sources. On the issue of how to apply 

PSD and title V to GHG sources, including the specific threshold 

levels and the timing, we believe that Congress could be 

considered to have intended that GHG sources be included in the 

PSD and title V programs at as close to the statutory thresholds 

as possible, and as quickly as possible to the greatest extent 

practicable. Under this view, EPA would be required at Chevron

step 1 to adopt the Tailoring Rule because, by phasing in PSD 

and title V applicability, it most closely gives effect to 

Congress’s intent. Under these circumstances, EPA is authorized 

to exercise its expert judgment as to the best approach for 

phasing in the application of PSD and title V to GHG sources.

Even so, we recognize that it could be concluded that on 

the issue of how to apply PSD and title V to GHG sources, 

congressional intent is unclear. Under these circumstances, EPA 

has the discretion at Chevron step 2 to adopt the Tailoring Rule 

because it is a reasonable interpretation of the statutory 

requirements. Under the Tailoring Rule, EPA seeks to include as 

many GHG sources in the permitting programs at as close to the 

statutory thresholds as possible, and as quickly as possible, 

although we recognize that we ultimately may stop the phase-in 

process short of the statutory threshold levels. 

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Deleted: . This view about 

congressional intent could 

be considered to be a 

logical inference from the 

fact that Congress wrote the 

applicability provisions 

broadly. ¶

Deleted: first 

Deleted: that PSD and title 

V each apply to GHG sources 

at emission levels as close 

to the statutory thresholds 

as possible and as quickly 

as possible. Even so, EPA 

is authorized to exercise 

its expert judgment as to 

the best approach for 

phasing in the application 

of PSD and title V to GHG 

sources. In addition, even 

under this view, we believe 

there may be uncertainty as 

to whether congressional 

intent to apply PSD and 

title V to GHG sources 

extends to very small GHG 

sources, that is, those at 

or near the statutory 

thresholds or whether 

congressional intent to 

apply title V to GHG sources 

extends to GHG sources that 

would have empty permits.¶

The second possible view is 

that Congress did not 

express an intent as to the 

applicability of PSD and 

title V to GHG sources. The 

lack of plain meaning in the 

definitional provisions, and 

silence elsewhere in the 

statutory provisions and 

legislative history, could 

be considered to support 

this conclusion

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Deleted: Here, too, EPA is 

authorized to exercise its 

expert judgment as to the 

best approach for phasing in 

the application of PSD and 

title V to GHG sources.
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Further, we are not deciding in this rule whether we 

believe Congress intended to include in the PSD and title V 

programs the smallest GHG sources, which are those emitting at 

or close to the applicability threshold levels. Instead, we 

will decide in subsequent rulemakings whether Congress intended 

to include such sources, intended that such sources not be 

included, or did not express an intent; and, if Congress did not 

express an intent, whether it is reasonable policy and 

consistent with the statutory requirements to include them in a 

highly streamlined manner. By the same token, with respect to 

“empty permits” for title V purposes, although, as noted 

elsewhere, we do not believe that Congress intended, under 

Chevron step 1 to preclude title V from applying to GHG sources 

that would have empty permits, we are not deciding whether 

Congress intended, under Chevron step 1 that title V apply to 

GHG sources with empty sources. Similarly, we are not deciding 

whether Congress should be said to have not expressed a clear 

intent, so that the Chevron step 2 analysis would apply.

It should also be noted that although EPA has concluded 

that applying the PSD and title V applicability provisions 

literally in the case of GHG sources would produce “absurd 

results” and therefore is not required, this conclusion has no 

relevance for applying other CAA requirements – such as the 

Deleted: We do not believe it 

necessary to choose between 

these two differing views as 

to congressional intent. 

Although each leads to a 

different analytical 

approach under Chevron, each 

also supports the Tailoring 

Rule. 
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requirements concerning endangerment and contribution findings 

under CAA section 202(a)(1) or emission standards for new motor 

vehicles or new motor vehicle engines under CAA section 202 -- 

to GHGs or GHG sources. EPA’s conclusions with respect to the 

PSD and title V applicability requirements are based on the 

specific terms of those requirements, other relevant PSD and 

title V provisions, and the legislative history of the PSD and 

title V programs. 

Within the context of the Chevron framework, the 

“administrative necessity” doctrine applies as follows: Under 

the doctrine, Congress is presumed to intend that the PSD and 

title V applicability requirements be administrable. Here, 

those applicability requirements, if applied to GHG sources in 

accordance with their literal meaning, would be impossible to 

administer. Accordingly, under Chevron step 1, it is consistent 

with congressional intent that EPA and the permitting 

authorities be authorized to implement the applicability 

requirements in a manner that is administrable, that is, through 

the tailoring approach. 

As for the “one-step-at-a-time” doctrine, we believe it

applies within the Chevron framework in conjunction with the 

“absurd results” and “administrative necessity” doctrines. As 

we discuss elsewhere, the PSD and title V applicability 

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is presumed to intend that 

EPA and the permitting 

authorities may administer
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provisions by their terms require that sources at or above the 

100/250 tpy thresholds comply with PSD and title V requirements 

at the time those requirements are triggered, which is when GHGs 

become subject to regulation. Therefore, if the literal meaning 

of the applicability provisions as applied to GHG sources were 

controlling – that is, if it reflected congressional intent --

it would foreclose use of the one-step-at-a-time doctrine to 

implement a phase-in approach. However, the literal meaning is 

not controlling because -- in light of the absurd results, 

including the insurmountable administrative burdens, that would 

result from the literal meaning -- congressional intent is not 

to require the application of the PSD and title V requirements 

to all GHG sources at or above the statutory thresholds at the 

time that GHGs become subject to regulation. Instead, as 

described previously, we consider congressional intent for the 

applicability provisions, as applied to GHG sources, either (i) 

to be clear that PSD and title V should be phased in for GHG 

sources as quickly as possible, or (ii) to be unclear, so that 

EPA may reasonably choose to phase PSD and title V in for those 

sources in that manner. Under either view, congressional intent 

for PSD and title V applicability to GHG sources accommodates 

the “one-step-at-a-time” approach. 

4. The PSD and Title V Programs

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appropriate. 

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Having discussed both the factual underpinnings and, 

immediately above, the legal underpinnings for our tailoring 

approach, we now discuss the PSD and title V programs 

themselves, including, for each program, the key statutory 

provisions, their legislative history, and the relevant 

regulations and guidance documents through which EPA has 

implemented the provisions. We start with the PSD program. 

a. The PSD program 

(1) PSD Provisions

Several PSD provisions are relevant for present purposes 

because of the specific requirements that they establish and the 

window that they provide into congressional intent. These 

provisions start with the applicability provisions, found in CAA 

sections 165(a) and 169(1), which identify the new sources 

subject to PSD, and CAA §111(a)(4), which describes the 

modifications of existing sources that are subject to PSD. CAA 

§165(a) provides: 

 No major emitting facility on which construction 

is commenced after August 7, 1977, may be constructed 

in any area to which this part applies unless— 

 (1) a permit has been issued for such proposed 

facility in accordance with this part setting forth 

emission limitations for such facility which conform 

to the requirements of this part; 

 (2) the proposed permit has been subject to a 

review in accordance with this section * * *, and a 

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public hearing has been held with opportunity for 

interested persons including representatives of the 

Administrator to appear and submit written or oral 

presentations on the air quality impact of such 

source, alternatives thereto, control technology 

requirements, and other appropriate considerations; 

* * * 

 (4) the proposed facility is subject to the best 

available control technology for each pollutant 

subject to regulation under this chapter emitted from, 

or which results from, such facility * * * *. 

The term "major emitting facility" is defined, under CAA 

§169(1) to include: 

* * * stationary sources of air pollutants which emit, 

or have the potential to emit, one hundred tons per 

year or more of any air pollutant from [28 listed] 

types of stationary sources. * * * Such term also 

includes any other source with the potential to emit 

two hundred and fifty tons per year or more of any air 

pollutant. This term shall not include new or 

modified facilities which are nonprofit health or 

education institutions which have been exempted by the 

State. 

As for modification of existing sources, CAA section 

169(1)(C) provides that the term "construction," as used in CAA 

section 165(a) (the PSD applicability section) "includes the 

modification (as defined in section 111(a)(4)) of any source or 

facility." Section 111(a)(4), in turn, provides: 

The term "modification" means any physical change in, or 

change in the method of operation of, a stationary source 

which increases the amount of any air pollutant emitted by 

such source or which results in the emission of any air 

pollutant not previously emitted. 

As interpreted by EPA regulations, these provisions, taken 

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together, provide that new stationary sources are subject to PSD 

if they emit at the 100/250-tpy thresholds air pollutants that 

are subject to EPA regulation, and that existing stationary 

sources that emit such air pollutants at the 100/250-tpy 

thresholds are subject to PSD if they undertake a physical or 

operational change that increases their emissions of such air 

pollutants by any amount. 

Other provisions of particular relevance are the 

requirements for timely issuance of permits. The permitting 

authority must “grant[] or den[y] [any completed permit 

application] not later than one year after the date of filing of 

such completed application.” CAA §165(c). 

In addition, the PSD provisions articulate ‘the purposes of 

[the PSD program],” which are to balance environmental 

protection and growth. CAA §160. One of the purposes, in 

subsection (1), is specifically “to protect public health and 

welfare,” and another, in subsection (3), is “to insure that 

economic growth will occur in a manner consistent with the 

preservations of existing clean air resources.” 

The PSD provisions also include detailed procedures for 

implementation. Most relevant for sources of GHG are the 

provisions that the proposed permit for each source must be the 

subject of a public hearing with opportunity for interested 
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persons to comment, CAA §165(a)(2), and each source must be 

subject to best available control technology, as determined by 

the permitting authority on a source-by-source basis, CAA 

§165(a)(4), 169(3). 

(2) PSD Legislative History

The legislative history of the PSD provisions, enacted in 

the 1977 CAA Amendments, makes clear that Congress was largely

on sources of criteria pollutants: primarily sulfur dioxide 

(SO2), PM, NOx, and carbon monoxide (CO). This is evident in the 

basic purpose of the PSD program, which is to safeguard 

maintenance of the NAAQS, combined with the limited awareness at 

that time of the problem of climate change. See S 95-127 (95th

Cong., 1st Sess.), at 27. 

 Congress designed the PSD provisions to impose significant 

regulatory requirements, on a source-by-source basis, to 

identify and implement BACT and, for criteria pollutant, to also 

undertake certain studies. Congress was well aware that because 

these requirements are individualized to the source, they are 

expensive. Accordingly, Congress designed the applicability 

provisions (i) to apply these requirements to industrial sources 

of a certain type and a certain size – sources within 28 

specified source categories and that emit at least 100 tpy -- as 

well as all other sources that emit at least 250 tpy, and, by 

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nitrogen oxides (

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quality standards (

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the same token, (ii) to exempt other sources from these 

requirements.34 

 Although Congress required that CAA requirements generally 

apply to “major emitting facilities,” defined as any source that 

emits or has the potential to emit 100 tpy of any pollutant, 

Congress applied PSD to only sources at 100 tpy or higher in 28 

specified industrial source categories, and at 250 tpy or more 

in all other source categories. This distinction was 

deliberate: According to Sen. McClure, Congress selected the 28 

source categories after reviewing an EPA study describing 190 

industrial source categories. 122 Cong. Rec. 24521 (July 29, 

1976) (statement by Sen. McClure). 

 Congress also relied on an EPA memorandum that identified 

the range of industrial categories that EPA regulated under its 

regulations that constituted the precursor to the statutory PSD 

 34 Coverage of modifications by the PSD program was 

addressed by a technical amendment which added a cross reference 

in section 169 to section 111. The legislative history of this 

provision is scant and there is no suggestion that Congress 

would have contemplated sweeping in large number of changes from 

smaller sources through the addition of this provision.

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program,35 and listed both the estimated number of new sources 

constructing each year and the amount of pollution emitted by 

the “typical plant” in the category. The memorandum was 

prepared by B.J. Steigerwald, Director of the Office of Air 

Quality Planning and Standards and Roger Strelow, EPA’s 

Assistant Administrator for Air and Waste Management 

(“Steigerwald-Strelow memorandum). The Steigerwald-Strelow 

memorandum makes clear that the 100 tpy cut-off for the 28 

listed sources categories, and the 250 tpy cut-off for all other 

sources, was meaningful; that is, there were a large number of 

sources below those cut-offs that Congress explicitly 

contemplated would not be included in PSD. Id. at 24548-50. 

Consistent with this, the legislative history on the Senate 

side also specifically identified certain source categories that 

Senators believed should not be covered by PSD. The Senate bill 

language limited PSD to sources of 100 tpy or more in 28 listed 

source categories, and to any other categories that the 

Administrator might add. Sen. Muskie stated that the Senate 

bill excluded “houses, dairies, farms, highways, hospitals, 

 35 Beginning in 1974, EPA implemented a program that required 

sources of certain NAAQS pollutants seeking to construct in 

attainment or unclassifiable areas to implement emission 

controls for the purpose of preventing deterioration in the 

ambient air quality in those areas. This program was the 

precursor to the PSD program Congress enacted in 1977.

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schools, grocery stores, and other such sources.” 123 Cong. 

Rec. 18021 (June 8, 1977) (statement of Sen. Muskie). Sen. 

McLure’s list of excluded source categories were “[a] small 

gasoline jobber, or a heating plant at a community college, 

[which] could have the potential to emit 100 tons of pollution 

annually.” 122 Cong. Rec. 24548-49 (July 29, 1976) (statement 

of Sen. McClure). The Senate Committee Report included a 

comparable list, and in describing it, concisely articulated the 

cost-conscious basis for the line-drawing: “[the PSD] procedure 

... must include an effective review-and-permit process. Such a 

process is reasonable and necessary for very large sources, such 

as new electrical generating plants or new steel mills. But the 

procedure would prove costly and potentially unreasonable if 

imposed on construction of storage facilities for a small 

gasoline jobber or on the construction of a new heating plant at 

a junior college, each of which may have the potential to emit 

100 tons of pollution annually.” S. Rpt. 95-127 at 96-97. 

The enacted legislation differs from the Senate bill by 

replacing the authorization to EPA to include by regulation 

source categories in addition to the listed 28 source categories 

with an inclusion of all other sources if they exceed 250 tpy, 

and with an authorization for the states to exempt hospitals and 

educational institutions. But Congress’s overall intention 

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remains clear, as the D.C. Circuit described in Alabama Power: 

"Congress's intention was to identify facilities which, due to 

their size, are financially able to bear the substantial 

regulatory costs imposed by the PSD provisions and which, as a 

group, are primarily responsible for emissions of the 

deleterious pollutants that befoul our nation's air....[With 

respect to] the heating plant operating in a large high school 

or in a small community college . . . [w]e have no reason to 

believe that Congress intended to define such obviously minor 

sources as 'major' for the purposes of the PSD provision."36 636 

F.2d at 353-54. 

 A particularly important indication of congressional intent 

to limit PSD to larger sources comes in considering the 

emissions profile of the small-sized boilers. Congress focused 

closely on identifying which sources with emissions in excess of 

100 tpy should not be subject to PSD even though they are 

subject to CAA requirements generally. But Congress viewed a 

large set of sources as emitting below 100 tpy and therefore not 

included in the PSD program and, indeed, not even subject to 

 36 Note that although Congress specifically authorized the 

states to exempt "nonprofit health or education institutions" 

from the definition of "major emitting facility," this statement 

by the D.C. Circuit should be taken as the Court's view that 

Congress did not design PSD to cover sources of the small size 

described. 

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debate as to whether they should be included in the PSD program. 

Chief among these sources, in terms of absolute numbers of 

sources, were small boilers. The Steigerwald-Strelow memorandum 

identified two categories of these boilers, differentiated by 

size. The first ranges in size from 10 to 250 x 106

 Btu/hr, and 

has a “typical plant” size of 107

 Btu/hr, with “BACT emissions 

from typical plant” of 53 tpy, and a total of 1,446 sources in 

the category. The second category ranges in size from 0.3 to 10 

x 106

 Btu/hr, and has a “typical plant” size of 1.3 x 106 Btu/hr, 

with “BACT emissions from typical plant” of 2 tpy, and a total 

of 11,215 sources in the category. The memorandum discusses 

these two categories in the context of explaining which source 

categories exceed a size of 100 tpy -- and therefore would be 

subject to PSD if a 100 tpy threshold were set -- by stating, 

“Fortunately, most truly small boilers and typical space heating 

operations would not be covered.” 122 Cong. Rec. 24549 (July 

29, 1976). 

 The legislative history also provides a window into the 

scope of the program that Congress anticipated and related 

administrability concerns. According to the Steigerwald-Strelow 

memorandum, the number of new sources each year whose “BACT 

emissions from typical plant” exceed 100 for the 28 listed 

source categories and 250 for all other source categories is 

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less than 100 per year. Although the Steigerwald-Strelow 

memorandum does not attempt to estimate the number of 

modifications, it appears that based on this information, 

Congress had reason to expect the total size of the PSD program 

to be measured in the hundreds of permits each year. A program 

of this size would be manageable by EPA and the permitting 

authorities. 

(3) PSD Regulatory History: Regulations Concerning the 

Definition of “Major Stationary Source” 

For present purposes, the regulatory history of the PSD 

program is most noteworthy because it shows that since the 

inception of the program following the 1977 CAA Amendments, EPA 

has interpreted the statutory PSD applicability provisions to 

apply more narrowly – to any air pollutant subject to regulation

– than their literal meaning (“any air pollutant”). EPA’s 

initial rulemaking implementing the PSD program, which was 

proposed and finalized in 1977-1978, made explicit that the 

entire PSD program applied to only pollutants regulated under 

the Act. 43 FR 26,380, 26,403/3, 26,406 (June 19, 1978) 

 38 As noted elsewhere in this notice, in Alabama Power, the 

D.C. Circuit noted that the definition of “major emitting 

facility” under CAA section 169(1) could apply to air pollutants 

not regulated under other provisions of the Act, and discussed 

the contrast of this broad definition to the narrower 

application of the BACT provisions. 636 F.2d at 352-53 & n. 60. 

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the Steigerwald-Strelow 

memorandum is included in 

the docket as docket number 

______.¶

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definition

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source

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rulemaking implementing the 

PSD program was proposed and 

finalized in 1977-1978, 

immediately after enactment

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permitting component (with 

air quality review) – 

Deleted: 37 EPA accomplished 

this by requiring each 

“major stationary source” to 

obtain a PSD permit, and by 

defining a “major stationary 

source” as a source that is 

included in a specified 

source category or that is 

of a specified size and that 

emits at least a specified 

amount of “any air pollutant 

regulated under the Clean 

Air Act.”
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(promulgating 40 CFR 51.21(b)(1)(i)). In 1979-1980, EPA revised 

the PSD program to conform to Alabama Power v. Costle, 636 F.2d 

323 (D.C. Cir. 1980). 44 FR 51,924 (Sept. 5, 1979) (proposed 

rule); 45 FR 52,676 (Aug. 7, 1980) (final rule). In this 

rulemaking, EPA did not disturb the pre-existing provisions that 

limited the applicability of the PSD program to regulated air 

 

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57,479, 57,480, 57,483 (Nov. 

3, 1977) (proposing 40 CFR 

51.21(b)(1)(i)). Similarly, 

the regulations required 

each “major stationary 

source” to apply “best 

available control 

technology” for “each 

pollutant subject to 

regulation under the act.” 

43 FR at 26,406 

(promulgating 40 CFR 

51.21(j), 52.21(b)(10)). 

EPA acknowledged that for 

regulatory purposes, it was 

replacing the term that 

appears in the statute – 

“major emitting facility,” 

CAA § 169(l) – with the term 

“major stationary source,” 

and explained that it was 

doing so in order “to 

reflect current EPA 

terminology.” 42 FR at 

57,480 (Nov. 3, 1977). EPA 

did not discuss that the 

statutory term “major 

emitting facility” – which 

refers to “any air 

pollutant” – differs from 

EPA’s regulatory term “major 

stationary source” – which 

refers more narrowly to “any 

air pollutant regulated 

under the [CAA].”

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final rule, EPA did not 

indicate that it had 

received any comments on the 

issue. See 43 FR 26,388 

(June 19, 1978). ¶

In 

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definitions of “major 

stationary source” and BACT) 
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pollutants.38 In 1996 EPA proposed, and in 2002 finalized, a set 

of amendments to the PSD provisions that included revisions to 

conform with the 1990 Act Amendments, which, in relevant part, 

exempted hazardous air pollutants from PSD, under CAA § 

112(b)(6). See 61 FR 38,250 (July 23, 1996), 67 FR 80,186 (Dec. 

31, 2002). In the preamble to the final rule, EPA noted that 

based on a request from a commenter, EPA was amending the 

regulations to “clarify which pollutants are covered under the 

PSD program.” EPA accomplished this by promulgating a 

definition for “regulated NSR pollutant,” which listed 

categories of pollutants regulated under the Act, and by 

substituting that defined term for the phrase “pollutants 

regulated under the Act” that was previously used in various 

parts of the PSD regulations. 67 FR at 80,240. The definition 

of “regulated NSR pollutant” includes several categories of 

pollutants (including, in general, NAAQS pollutants and 

precursors, pollutants regulated under CAA §111 new source 

performance standards, Class I or II substances regulated under 

CAA title VI) and a catch-all category, “[a]ny pollutant that 

otherwise is subject to regulation under the Act.” E.g., 40 CFR 

52.21(b)(50). As in the previous rulemakings, EPA did not 

 40 The House Committee on Energy and Commerce acknowledged 

that it was “uncertain about the magnitude of permit applications likely to be submitted 

under the bill initially and thereafter in each State or to EPA,” H. Rep. 101-490 p. 346.

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not discuss – or indicate 

that commenters had raised –

any issues concerning the 

difference between the 

narrower definition of 

“major stationary source” in 

the regulations and the 

statutory definition that 

could be broader under a 

literal reading.39¶

In 

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address the difference between the definition of “major emitting 

facility” and its regulatory approach or indicate that it had 

received comments on this issue. While the definition of “major 

modification” in the PSD regulations has changed over time with 

respect to how emission increases are calculated, the regulatory 

history with respect to pollutant coverage parallels that of 

major emitting facility. 

We recount this regulatory history as background 

information. We are not reconsidering or reopening these 

regulations to the extent they interpret the definition of 

“major emitting facility” and “modification” narrowly to be 

limited to pollutants subject to regulation under the Act.

b. Title V Program

Having reviewed the key statutory provisions, their 

legislative history, and the relevant administrative 

interpretations for the PSD program, we now do the same for the 

title V program. 

(1) Title V Provisions

The key title V provisions for present purposes start with 

the applicability provisions, which are found in CAA §§502(a), 

501(2)(B), and 302(j). These provisions provide that it is 

unlawful for any person to operate a "major source" without a 

title V permit, §502(a), and define a "major source" to include 

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"any major stationary facility or source of air pollutants which 

directly emits, or has the potential to emit, one hundred tons 

per year or more of any air pollutant." CAA §501(2)(B) and 

§302(j). As noted elsewhere, these provisions, taken together 

and as interpreted by EPA, provide that stationary sources are 

subject to title V if they emit at the 100-tpy threshold air 

pollutants that are subject to EPA regulation. 

In addition, although title V does not have a set of 

provisions describing its purpose, it is clear from its 

provisions and its legislative history, discussed later, that 

its key goal is to gather into one permitting mechanism the CAA

requirements applicable to a source and impose conditions 

necessary to assure compliance with such requirements, and 

thereby promote the enforceability of CAA requirements 

applicable to the covered sources. CAA §503(b)(1) requires that 

the source’s permit application contain a compliance plan 

describing how the source will ”comply with all applicable 

requirements” of the CAA, and §504(a) requires that “[e]ach 

permit issued under [title V] shall include * * * such * * * 

conditions as are necessary to assure compliance with applicable 

requirements of [the Clean Air Act].” See H.R. Rep. No. 101–

490, at 351 (1990) (‘‘It should be emphasized that the operating 

permit to be issued under this title is intended by the 

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Administration to be the single document or source of all of the 

requirements under the Act applicable to the source.’’). 

Importantly, title V is replete with provisions designed to 

make the permitting process as efficient and smooth-running as 

possible, including the expeditious processing of permit 

applications and the timely issuance of permits. CAA §503(c) 

requires that “the permitting authority shall approve or 

disapprove a completed application * * * and shall issue or deny 

the permit, within 18 months after the date of receipt thereof * 

* * *” CAA §502(b)(6) requires the permitting authority to 

develop “adequate, streamlined, and reasonable procedures for 

expeditiously determining when applications are complete, for 

processing such applications, for public notice * * * and for 

expeditious review of permit actions, including * * * judicial 

review in State court of the final permit action by [specified 

persons].” CAA §502(b)(7) includes a “hammer” provision 

designed to reinforce timely permit issuance, which is that the 

permitting authority’s program must include: 

To ensure against unreasonable delay by the permitting 

authority, adequate authority and procedures to 

provide that a failure of such permitting authority to 

act on a permit application or permit renewal 

application (in accordance with the time periods 

specified in [CAA §503] * * *) shall be treated as a 

final permit action solely for purposes of obtaining 

judicial review in State court of an action brought by 

any person referred to in paragraph (6) to require 

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that action be taken by the permitting authority on 

such application without additional delay. 

CAA §502(b)(8) requires the permit program to include 

“[a]uthority and reasonable procedures consistent with the need 

for expeditious action by the permitting authority on permit 

applications and related matters, to make available to the 

public [certain permit-related documents]”. CAA §502(b)(9) 

requires a permit revision to incorporate requirements 

promulgated after issuance of the permit, but only if the permit 

is for a major source and has a term of 3 or more years 

remaining. In addition, the revision must occur “as 

expeditiously as practicable.” CAA §502(b)(10) requires the 

permit program to include operational flexibility provisions 

that “allow changes within a permitted facility . . . without 

requiring a permit revision, if the changes are not 

modifications . . . and . . . do not exceed the emissions 

allowable under the permit. . . .” 

In addition, title V includes a comprehensive and finely 

detailed implementation schedule that mandates timely issuance 

of permits while building in EPA and affected state review, 

public participation, and timely compliance by the source with 

reporting requirements. Following the date that sources become 

subject to title V, they have 1 year to submit their permit 

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applications. CAA §503(c). As noted previously, the permitting 

authority then has 18 months to issue or deny the permit. CAA 

§503(c). Permitting authorities must provide an opportunity for 

public comment and a hearing. CAA §502(b)(6). If the 

permitting authority proposes to issue the permit, the 

permitting authority must submit the permit to EPA, and notify 

affected states, for review. CAA §505(a)(1). EPA then has 45 

days to review the permit and, if EPA deems it appropriate, to 

object to the permit. CAA §505(b)(1). If EPA does object, then 

the permitting authority must, within 90 days, revise it to meet 

the objections, or else EPA becomes required to issue or deny 

the permit. CAA §505(c). If EPA does not object, then, within 

60 days of the close of the 45-day review period, any person may 

petition EPA to object, and EPA must grant or deny the petition 

within 60 days. CAA §505(b)(2). If a permit is issued, it must 

include a permit compliance plan, under which the permittee must 

“submit progress reports to the permitting authority no less 

frequently than every 6 months,” and must “periodically (but no 

less frequently than annually) certify that the facility is in 

compliance with any applicable requirements of the permit, and 

[] promptly report any deviations from permit requirements to 

the permitting authority.” CAA §503(b). 

(2) Title V Legislative History

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(a) Scope of Title V 

The legislative history of title V, enacted by Congress in 

the 1990 CAA Amendments, indicates the scope of the program that 

Congress expected: Congress expected the program to cover some 

tens of thousands of sources, which would approximate the scope 

of the permit program under the Clean Water Act. The Senate 

Committee on Environment and Public Works stated: 

EPA estimates that the new permit requirements will 

cover about 8,200 major sources that emit 100 tons per 

year or more of criteria pollutants (which are 

regulated under SIPs). In addition, many smaller 

sources are (or, as EPA promulgates additional 

regulations, will be) covered by new source 

performance standards under section 111 of the Act, 

hazardous air pollutant standards under section 112 of 

Act, and nonattainment provisions of this legislation. 

By comparison, under the Clean Water Act, some 70,000 

sources receive permits, including more than 16,000 

major sources. Although many air pollution sources 

have more emission points than water pollution 

sources, the additional workload in managing the air 

pollution permit system is estimated to be roughly 

comparable to the burden that States and EPA have 

successfully managed under the Clean Water Act. 

S. Rep. 101–228, at 353 (1990).40 Sen. Mitchell, the Senate 

Majority Leader, stated that he expected “over 10,000 permits 

[to] . . . be issued under this program.” 136 Cong. Rec. S3239-

03 (March 27, 1990). Others in Congress had similar estimates. 

See, e.g., 136 Cong. Rec. S3166 (“thousands and thousands of 

permit applications ... will be required to be submitted”) 

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(statement of Sen. Nickles). 

Furthermore, the legislative history indicates that 

Congress did not contemplate that large numbers of very small 

sources would be subject to title V’s requirements. This 

becomes clear by reviewing the legislative history of a 

companion piece of legislation to the operating permits 

provisions that Congress enacted into CAA section 507, which is 

the “Small business stationary source technical and 

environmental compliance assistance program.” CAA section 507. 

Under this provision, sources that, among other things, “are not 

[] major stationary source[s]” and that emit less than 50 tpy of 

any regulated pollutant, as well as less than 75 tpy or all 

regulated pollutants, are eligible for assistance under CAA 

section 507. CAA section 507(c)(1). The House Committee Report 

described this provision – including what types of sources it 

expected this provision to benefit -- as follows: 

New section [507] is a small source/small 

business provision added by the Committee. It seeks 

to help small businesses to comply with the problems 

that are likely to occur under the Act as amended by 

this bill. For purposes of this section, small 

businesses or small emitters are defined as sources 

that are emitting 100 tons or less per year and that 

have a number of employees that would qualify them for 

assistance from the Small Business Administration 

(SBA). As we look to the future of environmental 

protection under the Act, we take special steps here 

to ensure that it is possible for these small 

businesses to comply with minimum hassle and in 

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recognition of the problems that are unique to them. 

Such small businesses include printers, furniture 

makers, dry cleaners, and millions of other small 

businesses in this country. 

House Committee Report, H.R. 101-590, at 354. In this manner, 

the House Committee Report made clear that it expected “millions 

of ... small businesses” -- including “printers, furniture makers, 

dry cleaners” and many others -- to benefit from the CAA section 

507 small source/small business program, but Congress did not 

expect them to become subject to the operating permit 

requirements of title V because their emissions fell below 100 

tpy, which is, in general, the threshold for title V 

applicability. 

The legislative history of title V confirms that Congress 

viewed a principal purpose of title V as providing a vehicle to 

compile the requirements applicable to the source. As the 

report of the House Committee on Energy and Commerce (“House 

Committee Report”) stated, ‘‘It should be emphasized that the 

operating permit to be issued under this title is intended by 

the Administration to be the single document or source of all of 

the requirements under the Act applicable to the source.” H.R. 

Rep. No. 101–490, at 351 (1990). Combined with the source’s 

reporting requirements, this compilation of applicable 

requirements would facilitate public awareness of a source’s 

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obligations and compliance and would facilitate compliance and 

enforcement. 

On the Senate side, Sen. Chafee, one of the floor managers 

of the bill, made a similar point: 

The permits will serve the very useful function 

of gathering and reciting in one place -- the permit 

document itself -- all of the duties imposed by the 

Clean Air Act upon the source that holds the permit. 

This would clearly be an improvement over the present 

system, where both the source and EPA must search 

through numerous provisions of state implementation 

plans and regulations to assemble a complete list of 

requirements that apply to any particular plant.... 

Once these permits are in place, plant managers 

will be better able to understand and to follow the 

requirements of the Clean Air Act. At the same time, 

EPA will be better able to monitor how well each plant 

is complying with those requirements. This is a 

highly sensible approach for all concerned. 

136 Cong. Rec. S213 (January 24, 1990) (statement of Sen. 

Chafee). Sen. Lieberman made a similar statement. 136 Cong. 

Rec. 3172-73 (March 26, 1990) (statement of Sen. Lieberman). 

Thus, a central purpose of the title V permit program is to 

compile all the requirements applicable to the source into a 

single place, the permit. Implicit in this purpose is that the 

sources subject to title V will have applicable requirements to 

be compiled. As Sen. Chafee directly stated, “[T]he vast 

majority of these permit applications will ... , in all 

likelihood, only codify the existing requirements of the 

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applicable State implementation plan.” 136 Cong. Rec. S2720

(March 20, 1990) (statement of Sen. Chafee). 

More broadly, the legislative history also indicates 

congressional concern about the costs of permitting for small 

businesses, and a determination to minimize those costs to the 

extent possible. This concern is reflected in several 

provisions of title V. For example, section 502(a) authorizes 

EPA to exempt all or part of a source category – except for any 

major source -- from the title V permit program if EPA “finds 

that compliance with [title V] requirements is impracticable, 

infeasible, or unnecessarily burdensome on such categories.” 

Similarly, the permit fee provisions include a presumptive 

minimum fee amount, but authorize an exemption from that 

presumptive amount upon a showing that a lesser amount will meet 

overall fee requirements, CAA section 502(b)(3)(B)(iv). One of 

the drafters of this provision, Rep. Wyden, explained that its 

purpose was to preserve the flexibility of states to impose 

lower fees of small businesses: 

I note that the provision on fees allows 

reductions for small sources where appropriate. The 

state has some flexibility, under the general permit 

fee provisions, to adjust fee levels for any source so 

long as the average fee charged meets the statutory 

minimum. 

136 Cong. Rec. H12884 (Oct. 26, 1990) (statement of Rep. Wyden). 

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See e.g., 136 Cong. Rec. H2559 (May 21, 1990) (statement of 

Rep. Wyden) (discussing need to “help small businesses through 

the air permit labyrinth”). 

 The legislative history also indicates that Congress was 

deeply concerned both about the need not to burden sources 

generally with undue costs and to assure the administrability of 

the title V program, and as a result, was determined to make the 

program as smooth-running as possible. These goals are 

reflected in many of the title V requirements, as discussed 

previously. See, e.g., CAA §502(b)(6) (requiring “adequate, 

streamlined, and reasonable procedures for expeditiously 

determining when applications are complete, for processing such 

applications, for public notice * * * and for expeditious review 

of permit actions); CAA §502(b)(7) (includes a “hammer” 

provision designed to reinforce timely permit issuance); CAA 

§502(b)(9)-(10) (limiting circumstances under which permit 

revision is required; requiring revision to occur “as 

expeditiously as practicable;” including operational flexibility 

provisions). 

The legislative history confirms that these provisions were 

designed to reduce costs to sources and promote 

administrability. The “Chafee-Baucus Statement of Senate 

Managers” for the bill explained the purpose of the CAA section 

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502(b)(6) requirement for “[a]dequate, streamlined, and 

reasonable procedures for expeditious[]” permit actions as 

follows: 

[M]uch concern has been expressed that this new 

permitting process will unduly delay the proper 

functioning of many sources, and we intend to mitigate 

any delay by directing that the process be 

expeditious. 

 In addition to this general directive for expeditious 

processing, we mandate in new section 503 that 

permitting authorities approve or reject permit 

applications within certain specified time periods 

following filing. In this fashion, we have taken 

explicit steps to protect against undue delays. 

136 Cong. Rec. S16941 (statement of Sen. Chafee). The same 

statement explained that the permit revision procedures of CAA 

section 502(b)(9) reflect a – 

careful effort to ensure that the permit program works 

effectively and efficiently. Succinctly, this 

provision accommodates two competing concerns. On the 

one hand, it is important to ensure that permit 

requirements remain up-to-date as the provisions of 

the Clean Air Act are developed and new requirements 

are imposed. On the other hand, it also is important 

to be sure that we do not reduce the permit program to 

a shambles by requiring sources to engage in a 

continuous process of revising their permits as these 

new requirements are imposed. 

136 Cong. Rec. 16942 (Oct. 27, 1990) (Chafee-Baucus 

statement of Senate Managers) (statement of Sen. Chafee). 

 In addition, these concerns were at the bottom of the 

following statement by Sen. Chafee, in which he described how 

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the bill’s drafters had revised it in response to a concern by 

industry that an earlier version of the bill would have put 

undue costs on industry: 

We have also heard concerns from industry that S. 

1630 would burden sources unduly by requiring them to 

submit-along with their permit applications-plans 

explaining how they intend to comply with all 

requirements of the Clean Air Act that apply to them. 

But, Mr. President, we emphatically do not intend 

to burden industry with preparation and submission of 

unnecessary compliance plans. The substitute 

clarifies that any compliance plans would address only 

those matters by which the sources would comply with 

new requirements imposed by this act as it is finally 

signed into law. These plans would not need to address 

compliance with any existing Clean Air Act 

requirements, unless the source is in violation of 

those requirements. 

136 Cong. Rec. S2107 (March 5, 1990) (statement of Sen. Chafee). 

As another indication of congressional concern over 

administrability, Congress recognized that at the beginning of 

the program, large numbers of permit applications might 

overwhelm the permitting authorities. To protect against this, 

Congress included in CAA section 503(c) a phase-in schedule for 

permitting authorities to act on the initial set of permit 

applications. Under 503(c), permitting authorities were not 

required to act on the initial set of permit applications within 

18 months after it received the application, but rather could 

act on one-third of them on an annual basis over a 3-year 

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period. Sen. Chafee, in describing an early version of this 

provision – which would have allowed permitting authorities to 

phase-in the submission of permit applications – explained that 

its purpose was “to avoid a logjam of permit applications[,] ... 

ensure that [regulatory] gridlock can be avoided, and [ensure] 

that the permitting process will work with a minimum of 

disruption and delay.” 136 Cong. Rec., S2106 (March 5, 1990) 

(statement of Sen. Chafee). 

(3) Title V Regulatory History

 

 As with PSD, for present purposes, the regulatory history 

of the title V program is most noteworthy because it shows that 

beginning shortly after the inception of the program following 

the 1990 CAA Amendments, EPA has interpreted the statutory title 

V applicability provisions to apply more narrowly – to any air 

pollutant subject to regulation – than their literal meaning 

(“any air pollutant”). As discussed previously, title V applies 

to any “major source,” defined, as relevant here, under CAA 

sections 501(2)(B) and 302(j), as “any stationary facility or 

source of air pollutants which directly emits, or has the 

potential to emit, one hundred tons per year or more of any air 

pollutant....” EPA’s regulations mirror the CAA definitional 

provisions. 40 CFR 70.2. 

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(3) 

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Congress enacted title V as 

part 

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provide that a title V 

program must provide for 

permitting “[a]ny major 

source,” 40 CFR 70.3(a), 

defined, as relevant here, 

as “[a] major stationary 

source of air pollutants, as 

defined in section 302 of 

the Act, that directly emits 

or has the potential to 

emit, 100 tpy or more of any 

air pollutant....” 
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 However, since 1993, EPA has interpreted the applicability 

provisions more narrowly. At that time, which was shortly after 

title V was enacted, EPA issued a guidance document making clear 

that it interprets this requirement to apply to sources of 

pollutants “subject to regulation” under the Act. Memorandum 

from Lydia N. Wegman, Deputy Director, Office of Air Quality 

Planning and Standards, U.S. EPA, “Definition of Regulated Air 

Pollutant for Purposes of Title V” (Apr. 26, 1993) (Wegman 

Memorandum). The interpretation in this memorandum was based 

on: (1) EPA’s reading of the definitional chain for “major 

source” under title V, including the definition of “air 

pollutant” under section 302(g) and the definition of “major 

source” under 302(j); (2) the view that Congress did not intend 

to require a variety of sources to obtain title V permits if 

they are not otherwise regulated under the Act (see also CAA 

section 504(a), providing that title V permits are to include 

and assure compliance with applicable requirements under the 

Act); and (3) consistency with the approach under the PSD 

program. 

While the specific narrow interpretation in the Wegman 

Memorandum of the definition of “air pollutant” in CAA section 

302(g) is in question in light of the holding in the 

Massachusetts case (finding this definition to be “capacious,” 

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articulated its 

interpretation that this 

title V permitting 

requirement applies to 

“pollutants subject to 

regulation” in a 1993 

memorandum from EPA’s air 

program. 

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Massachusetts v. EPA, 549 U.S. 497, 533 (2077)), EPA believes 

that its overall rationale for its interpretation of the 

applicability of title V remains sound. EPA continues to 

maintain its interpretation, consistent with CAA sections 

302(j), 501, 502 and 504(a), that the provisions governing title 

V applicability for “a major stationary source” can only be 

triggered by emissions of pollutants subject to regulation. 

This interpretation is based primarily on the purpose of title V 

to collect all regulatory requirements applicable to a source 

and to assure compliance with such requirements, see, e.g., CAA 

section 504(a), and on the desire to promote consistency with 

the approach under the PSD program. 

 In the Tailoring Rule notice of proposed rulemaking, EPA 

acknowledged the Wegman Memorandum and affirmed the memorandum’s 

continued viability, stating that “EPA continues to maintain 

this interpretation.” 74 FR 55,300, col. 3, fn. 8; see also 75 

FR at 17022-23 (Interpretive Memorandum Reconsideration). 

As with PSD, we recount this regulatory history as 

background information, and we are not reconsidering or reopening this interpretation of the definition of “major source” 

narrowly to be limited to pollutants subject to regulation under

the Act.

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5. Application of the “Absurd Results” Doctrine for the PSD 

Program

Having reviewed the factual background, legal doctrines, 

and the key components of the PSD and title V programs, we now 

turn towards interpreting the PSD and title V requirements in 

accordance with the Chevron framework, accounting for the 

applicable legal doctrines. We begin with the “absurd results” 

doctrine, and apply it first to the PSD requirements. 

In this action, we finalize, with some refinements, the 

“absurd results” basis we proposed. Specifically, we are 

revising our regulations to limit PSD applicability to GHG 

emitting sources by revising the regulatory term, “regulated NSR 

pollutant,” and although our revised regulations do not accord 

with a literal reading of the statutory provisions for PSD 

applicability, which are incorporated into the definition of 

“major emitting facility” and “major modification,” we have 

concluded that based on the “absurd results” doctrine, a literal 

adherence to the terms of these definitions is not required. A 

literal adherence would not reflect congressional intent that

PSD apply to GHG sources as a general matter. Further, we may

apply PSD to GHG sources in a phased-in manner, as we do through 

the tailoring approach, because either congressional intent is 

clear on that issue and the tailoring approach best reflects it, 

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doctrine

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or congressional intent is unclear and the tailoring approach is 

a reasonable interpretation of the statute. However, in this 

rulemaking, it is not necessary to make decisions, and we do not 

do so, about congressional intent for applying PSD to smaller 

GHG sources, that is, those that emit at or close to the 

statutory thresholds. 

a. Congressional Purpose for the PSD Program 

To reiterate, for convenience, CAA §169(1) defines a “major 

emitting facility” to include “any ... source[] [that] emit[s], or 

ha[s] the potential to emit, [depending on the source category], 

one hundred [or two hundred fifty] tons per year or more or more 

of any air pollutant.” CAA § 169(1); and a “modification” as 

any physical or operational change in “a stationary source which 

increases the amount of any air pollutant emitted by such 

source,” CAA § 169(2)(C), 111(a)(4). We also reiterate that, as 

discussed above, beginning with our initial rulemaking in 1977-

1978 to implement the PSD program, we have interpreted these

definitions more narrowly by reading into them the limitation 

that a source is subject to PSD only if the air pollutants in 

question are “subject to regulation under the Act.” 

51.166(b)(49)(iv). EPA is not re-opening this interpretation in

this regulation in this action. 

Deleted: Intent

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definition

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regulation under another 

Clean Air Act provision. We 

have maintained this 

approach to the present time 

through several additional 

rulemaking actions, albeit 

with refinements not here 

relevant, and in all the 

various rulemakings, our 

approach has never been 

seriously questioned by 

stakeholders. As the U.S. 

Supreme Court recently 

stated in upholding an EPA 

approach in another context: 

“While not conclusive, it 

surely tends to show that 

the EPA’s current practice 

is a reasonable and hence 

legitimate exercise of its 

discretion . . . that the 

agency has been proceeding 

in essentially this fashion 

for over 30 years.” Entergy 

Corp. v. Riverkeeper, Inc., 

129 S.Ct. 1498, 1509 (2009) 

(citations omitted). Under 

the current regulations, PSD 

applies to a “major 

stationary source” (a term 

that EPA employed as the 

regulatory implementation of 

the statutory term, “major 

emitting facility”), which 

is defined as a source that, 

in general “emits, or has 

the potential to emit, 

[depending on the source 

category], 100 [or 250] tons 

per year or more of any 

regulated NSR pollutant,” 

51.166(b)(1)(i)(a)-(b); and 

the term “regulated NSR 

pollutant” includes, in 

general, pollutants 

regulated under the NAAQS, 

the NSPS, and title VI, as 

well as “[a]ny pollutant 

that is ... 

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Under the current interpretation of the PSD applicability 

provision, EPA’s recent promulgation of the light-duty vehicle 

rule will trigger the applicability of PSD for GHG sources at 

the 100/250 tpy threshold levels as of January 2, 2011. This is 

because PSD applicability hinges on the definition of “major 

emitting facility,” which, under EPA’s long-standing narrowing 

interpretation, but absent further tailoring, applies PSD to 

sources of any air pollutant subject that is subject to 

regulation under another provision of the CAA. EPA’s 

promulgation of the light-duty vehicle rule means that GHGs will 

become subject to regulation on the date that the rule takes 

effect, which will be January 2, 2011. 

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But absent tailoring, the January 2, 2011 trigger date for 

GHG PSD applicability will subject an extraordinarily large 

number of sources, more than 81,000, to PSD each year, an 

increase of almost 300-fold. And the great majority of these 

new sources will be small commercial or residential sources. We 

believe that for many reasons, this result is contrary to 

congressional intent for the PSD program, and in fact would 

severely undermine what Congress sought to accomplish with the 

program. As a result, under our Chevron analysis, accounting 

for the “absurd results” doctrine, the statutory definition for 

“major emitting facility” (as interpreted narrowly to include 

“subject to regulation”) should not be read to apply to all GHG 

sources at or above the 100/250 tpy threshold as of the January 

2, 2011 date. Rather, the definitions of “major emitting 

facility” and “modification” should be tailored so that they 

applies to GHG sources on a phased-in basis, with the largest 

sources first, as we describe in this rule. 

As explained previously, Chevron step 1 calls for a 

determination of congressional intent, and the courts consider 

the best indicator of congressional intent to be the plain 

meaning of the statute. However, the United States Supreme 

Court has held that the literal meaning of a statutory provision 

is not conclusive “in the ‘rare cases [in which] the literal 

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application of a statute will produce a result demonstrably at 

odds with the intentions of the drafters’ ... [in which case] the 

intention of the drafters, rather than the strict language, 

controls.” United States v. Ron Pair Enterprises, 489 U.S. 235, 

242 (1989). To determine whether “the intentions of the . . . 

drafters” differ from the result produced from “literal 

application” of the statutory provisions in question, the courts 

may examine the overall context of the statutory provisions, 

including whether there are related statutory provisions that 

either conflict or are consistent with that interpretation; and 

the legislative history to see if it exposes what the 

legislature meant by the terms in question. In addition, the 

courts may examine whether a literal application of the 

provisions produces a result that the courts characterize 

variously as absurd, futile, strange, or indeterminate, and 

therefore so illogical or otherwise contrary to sensible public 

policy as to be beyond anything Congress would reasonably have 

intended. In such cases, the literal language cannot be said to 

reflect the intention of the drafters, and therefore does not 

control. See United States v. Ron Pair Enterprises, 489 U.S. 

235, 242-43 (1989); Griffin v. Oceanic Contractors, Inc., 458

U.S. 564, 571 (1982). 

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Here, applying the definitions of “major emitting facility” 

and “modification” without tailoring – that is, applying PSD to 

GHG sources at the 100/250 tpy level and applying the 

modification provisions by their terms without tailoring -- 

would be contrary to congressional purpose for the PSD 

provisions, as found in the statutory provisions and legislative 

history, especially in light of the impact from applying PSD to 

those sources. Congress established the PSD program in large 

measure because it was concerned that around the country, 

industrial development, which was confronting barriers to 

locating in nonattainment areas (that is, areas that do not meet 

the NAAQS), would attempt to locate in clean air areas (that is, 

attainment areas or unclassifiable areas), but that as a 

consequence, the clean air areas would see their air quality 

deteriorate to the point where they, too, would no longer meet 

the NAAQS. The end result would be the spread of environmental 

and health problems to those formerly clean air areas, as well 

as more barriers to further industrial development. With these 

concerns in mind, Congress designed the PSD program to require

newly constructing or modifying sources in areas with air 

quality that meets the NAAQS (or that is unclassifiable) to 

analyze their emissions of NAAQS pollutants and to implement 

controls as needed to assure that those emissions do not 

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significantly deteriorate air quality. Many of the PSD 

requirements, and much of the discussion in the legislative 

history, reflect these aspects of the PSD program. E.g., CAA 

sections 162, 163, 164, 165(a)(3), 165(d)(2), 165(e), 166; see 

generally H. Rep. 95-294, 95th Cong., 1st Sess. (1977) 103-78. 

Congress also designed the PSD program to impose controls 

on non-NAAQS pollutants, through the requirement under CAA 

section 165(a)(4) that the source be “subject to the best 

available control technology [(“BACT”)]for each pollutant 

subject to regulation under this chapter emitted from, or which 

results from, such facility.” For example, when Congress 

enacted the PSD provisions in 1977, sources emitting HAPs were 

required to implement BACT for those pollutants, although in the 

1990 CAA Amendments, Congress redesigned CAA section 112, which 

includes the requirements for HAPs, and excluded HAPs from PSD. 

CAA § 112(b)(6). 

Congress was keenly aware that the PSD program needed to 

serve two purposes: protect the environment and promote 

economic growth. Congress explicitly identified these two goals 

in the “purposes” section of the PSD provision, CAA § 160, and 

various PSD requirements clearly reflect them. For example, to 

protect economic growth, the PSD program expedites the permit 

process to include a 1-year limitation on the time that the 

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permitting authority has act on permit applications. To protect 

the environment, in addition to including many provisions that 

focus on NAAQS pollutants, the PSD program requires that the 

preconstruction permit impose emission limits that reflect BACT 

for each pollutant subject to regulation under another CAA 

provision. CAA section 165(a)(4). This BACT provision also 

makes clear, by its terms, that although Congress designed the 

PSD program primarily with NAAQS pollutants in mind, Congress 

also intended that sources subject to PSD control the emissions 

of their other pollutants as well. The D.C. Circuit has 

recognized the twin goals of environmental protection and 

economic development that underlie PSD, and has upheld EPA 

interpretations of the PSD program that reflect a balancing of 

those goals. See, e.g., New York v. EPA, 413 F.3d 3, 27 (D.C. 

Cir.), rehearing en banc den. 431 F.3d 801 (2005). 

Congress was also keenly aware that the PSD analyses and 

controls that it was mandating had to be implemented on a 

source-by-source basis, and that this process would be expensive 

for sources. As a result, Congress intended to limit the PSD 

program to large industrial sources because it was those sources 

that were the primary cause of the pollution problems in 

question and because those sources would have the resources to 

comply with the PSD requirements. Congress’s mechanism for 

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limiting PSD was the 100/250 tpy threshold limitations. Focused 

as it was primarily on NAAQS pollutants, Congress considered 

sources that emit NAAQS pollutants in those quantities generally 

to be the large industrial sources to which it intended PSD be 

limited. 

That Congress paid careful attention to the types and sizes 

of sources that would be subject to the PSD program and designed 

the thresholds deliberately to limit the program’s scope is 

evident from the legislative history. Several Senate floor 

statements and the Committee Report made clear in their 

insistence that PSD should not apply to small sources. As 

discussed later, Congress scrutinized information that EPA 

provided as to types and sizes of sources, found largely in the 

Steigerwald-Strelow memorandum. Sen. McClure stated that the 

Senate bill excluded “houses, dairies, farms, highways, 

hospitals, schools, grocery stores, and other such sources.” 

123 Cong. Rec. 18021 (June 8, 1977) (statement of Sen. Muskie). 

Sen. McClure stated that PSD should be limited to “industrial 

plants of significant impact,” and should exclude ”[a] small 

gasoline jobber, or a heating plant at a community college, 

[which] could have the potential to emit 100 tons of pollution 

annually.” 122 Cong. Rec. 24548-49 (July 29, 1976) (statement 

of Sen. McClure). The Senate Committee Report mirrored Sen. 

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several occasions, as well 

as discussion in 

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sources:

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McClure’s statement, and concisely articulated the cost-related

basis for the line-drawing: “[The PSD] procedure ... must include 

an effective review-and-permit process. Such a process is 

reasonable and necessary for very large sources, such as new 

electrical generating plants or new steel mills. But the 

procedure would prove costly and potentially unreasonable if 

imposed on construction of storage facilities for a small 

gasoline jobber or on the construction of a new heating plant at 

a junior college, each of which may have the potential to emit 

100 tons of pollution annually.” S. Rpt. 95-127 at 96-97. 

The D.C. Circuit had occasion, in Alabama Power, to 

acknowledge this legislative history. "Congress's intention was 

to identify facilities which, due to their size, are financially 

able to bear the substantial regulatory costs imposed by the PSD 

provisions and which, as a group, are primarily responsible for 

emissions of the deleterious pollutants that befoul our nation's 

air." Alabama Power, 636 F.2d at 353. The Court added, “Though 

the costs of compliance with [the PSD] requirements are 

substantial, they can reasonably be borne by facilities that 

actually emit, or would actually emit when operating at full 

capacity, the large tonnage thresholds specified in section 

169(1).”. Id. at 354. 

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It is not too much to say that applying PSD requirements to 

GHG sources without tailoring the definition of “major emitting 

facility” would result in a program that would have been 

unrecognizable to the Congress that designed PSD. Congress 

intended that PSD be limited to a relatively small number of 

large industrial sources. Without tailoring – that is, without 

phasing in PSD and title V applicability to GHG sources so as to 

allow the development of streamlining methods and increases in 

permitting authority resources -- the PSD program would expand 

by January 2, 2011 from the current 280 sources per year to 

almost 82,000 sources, virtually all of which would be smaller 

than the sources currently in the PSD program and most of which 

would be small commercial and residential sources. Until EPA 

could develop streamlining methods, all of the sources that 

would become newly subject to PSD – whether they be larger or 

smaller sources, whether industrial or commercial/residential 

sources -- would have to undergo source-specific BACT 

determinations for their GHG emissions, as well as their 

emissions of conventional pollutants in amounts in excess of the 

significance levels. We estimate that the commercial and 

residential sources – the great majority of which are small 

business -- would each incur, on average, almost $60,000 in PSD 

permitting expenses. This result would be anathema to 
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Congress’s careful efforts to confine PSD to large industrial 

sources. 

 A closer look at the legislative history confirms the view 

that sweeping in large numbers of small commercial and 

residential sources is precisely what Congress thought it was 

avoiding by establishing the 100/250 tpy thresholds. As noted 

previously, Congress relied on an EPA memorandum – the 

Steigerwald-Strelow memorandum -- that identified the range of 

industrial categories that EPA regulated under its program that 

constituted the precursor to the statutory PSD program, and 

listed both the estimated number of new sources constructing 

each year and the amount of pollution emitted by the “typical 

plant” in the category. The Steigerwald-Strelow memorandum 

makes clear that the 100 tpy cut-off for the 28 listed sources 

categories, and the 250 tpy cut-off for all other sources, would 

exclude from PSD a large number of sources. 122 Cong. Rec.

24548-50 (July 29, 1976). However, virtually all, if not all,

of the sources in half the 28 source categories emit carbon 

dioxide in quantities that equal or exceed the 100 tpy 

threshold, and almost all of the sources in the remaining 

categories emit CO2 in quantities that equal or exceed the 100 

tpy threshold. Therefore, applying the “major emitting 

facility” definition to GHG sources, without tailoring, would, 

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and therefore would be swept 

into PSD through application 

of the 

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estimate that over 700,000 

commercial facilities and 

180,000 residential 

facilities

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as a practical matter, vitiate much of the purpose of the 100 

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tpy cut-off for industrial sources.42

Most telling, in this regard, is the small-sized boilers, 

which the Steigerwald-Strelow memorandum describes, in terms of 

size, pollutants emitted, and numbers of sources, as follows: 

The memorandum identified two categories of these boilers, 

differentiated by size. The first ranges in size from 10 to 250 

x 106

 Btu/hr, and has a “typical plant” size of 107 Btu/hr, with 

“BACT emissions from typical plant” of 53 tpy, and a total of 

1,446 sources in that category. The second category ranges in 

size from 0.3 to 10 x 106 Btu/hr, and has a “typical plant” size 

of 1.3 x x 106

 Btu/hr, with “BACT emissions from typical plant” 

of 2 tpy, and a total of 11,215 sources in the category. That

 

42 Specifically, of the 28 source categories under CAA 

section 169(1), information available to EPA indicates that all 

of the sources in the following categories emit at least 100 tpy 

of CO2 annually: fossil-fuel fired steam electric plants of more 

than 250 million Btu per hour heat input, Portland Cement 

plants, primary zinc smelters, iron and steel mill plants, 

primary aluminum ore reduction plants, municipal incinerators 

capable of charging more than 50 tons of refuse per day, nitric 

acid plants, petroleum refineries, lime plants, primary lead 

smelters, fossil-fuel boilers of more than 250 Btus per hour 

heat input. In addition, all but a few kraft pulp mills and 

glass fiber processing plants emit at least 100 tpy CO2 annually. 

Our information is incomplete with respect to the remaining 

source categories, but with the possible exception of petroleum 

storage and transfer facilities with a capacity exceeding three 

hundred thousand barrels, we suspect that all but at most a few 

sources emit at least 100 tpy CO2 annually. See "Technical 

Support Document for Greenhouse Gas Emissions Thresholds 

Evaluation"; Office of Air Quality Planning and Standards; March 

29, 2010.

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memorandum makes clear that EPA did not believe that sources in 

these two categories – and especially the smallest one – would 

be subject to PSD under a 100 tpy threshold, by stating, 

“Fortunately, most truly small boilers and typical space heating 

operations would not be covered.” 122 Cong. Rec. 24549 (July 

29, 1976). However, these data and conclusions were all based 

on emissions of NAAQS pollutants, the amounts of which placed 

these boilers well below the PSD threshold limitations. In 

general, most boilers of these small sizes are fired with 

natural gas, and a natural gas boiler greater than 0.5 x 106

Btu/hr emits at least 250 tpy CO2. Therefore, if the CO2 

emissions of these small boilers are considered – as would occur 

by applying the definition of “major emitting facility” to GHG 

sources without tailoring -- then most of them would in fact be 

subject to PSD. Again, this result would directly contravene 

Congress’s intention to limit PSD to “industrial plants of 

significant impact.” 122 Cong. Rec. 24548-49 (statement of Sen. 

McClure). 

 Perhaps the most compelling reason why applying the PSD 

program to GHG sources without tailoring, and before the 

development of streamlining methods, would be inconsistent with 

congressional intent, is that the resulting program would prove 

unadministrable. Although the legislative history of the PSD 

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explaining which source 

categories exceed a size of 

100 tpy -- and therefore

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significant concerns about 

the cost of PSD permitting 

if the statutory threshold 

were to apply for GHG 

emissions. One commenter 

estimated a cost of over $5 

billion and the dedication 

of over 17,000 FTEs to this 

effort. 
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program does not reveal much explicit congressional focus on

administrability issues, the Steigerwald-Strelow Memorandum, 

which identifies the source categories and numbers of sources 

that were before Congress as it considered PSD, suggests that 

the program that Congress fashioned could be expected to cover 

at most a few thousand sources each year. This appears to be 

approximately the size of the program that EPA administered 

before the 1977 CAA Amendments, so that it seems reasonable to 

assume that Congress expected the PSD program it enacted to be 

within EPA’s and the states’ administrative capacities. 

 Moreover, the Alabama Power court stressed the importance 

of administrability concerns: Most importantly, the Court held 

that EPA, in interpreting the “modification” provisions that 

apply PSD to physical or operational changes by major emitting 

facilities that “increase[] the amount of any air pollutant 

emitted,” CAA section 111(a)(4), may “exempt from PSD review 

some emission increases on grounds of de minimis or 

administrative necessity,” and went on to state that in 

establishing the exemption thresholds, “[t]he Agency should look 

at the degree of administrative burden posed by enforcement at 

various de minimis threshold levels.” 636 F.2d at 400,405. In 

addition, the Court based its holding that potential-to-emit for 

purposes of the applicability thresholds should be defined as 

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emissions at full capacity with implementation of control 

equipment, in part on its view that with this definition, the 

number of sources subject to PSD would be manageable: 

Though the costs of compliance with section 165 

requirements are substantial, they can reasonably be 

borne by facilities that actually emit, or would 

actually emit when operating at full capacity, the 

large tonnage thresholds specified in section 169(1). 

The numbers of sources that meet these criteria, as we 

delineate them, are reasonably in line with EPA’s 

administrative capability. 

Alabama Power, 636 F.2d at 354. However, applying PSD to GHG 

sources without tailoring would increase the size of the PSD 

program at least an order of magnitude beyond what Congress 

could have had any reason to expect, which would have been far 

beyond the “administrative capability” that Alabama Power

described EPA as having. 

Beyond this disconnect with congressional expectations, 

what is most important is that the extraordinarily large number 

of permit applications would overwhelm permitting authorities 

and slow their ability to process permit applications to a 

crawl. Our best estimate at present is that permitting 

authorities would need to process almost 82,000 permit 

applications per year, compared to, at most, 800 in the current 

PSD program. The total additional workload, in workhours, for 

PSD permits would be more than 19.5 million more work hours, 

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compared to 150,795 work hours for the current PSD program, and 

the total additional costs for would be over $1.5 billion, 

compared with $12 million for the current PSD program. 

At proposal, we noted that the states had estimated that 

the influx of permit applications that would result from 

applying the 250 tpy threshold at actual emissions would, 

without additional resources result in permitting delays of 3

years. In fact, as we noted at proposal, a literal reading of 

the PSD requirements would require their application at the 250 

toy PTE level, which would result in ten times more permit 

applications than were assumed when the states made the 3-year 

estimate. Further, our current estimates of the numbers of 

sources that would be subject to PSD requirements are about 

twice what we estimated at proposal, as described elsewhere. 

Moreover, our estimate of the number of hours that permitting 

authorities would need to process a permit application from a 

source in the commercial or residential sector – which is, by 

far, the largest single sector – is three and one-half times as 

long as we estimated at proposal. And under a literal reading 

of the PSD applicability provisions as applied to GHG sources, 

the permitting authorities would be required to implement a 

program of this size beginning on January 2, 2011, less than 9

months from now. We received many comments from states and 

Deleted: ,

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Deleted: potential to emit 

Deleted: States 

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Deleted: 

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In light of these 
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industry raising concerns about the cost to sources and 

administrative burdens of PSD permitting if the statutory 

threshold were to apply for GHG emissions. One commenter 

estimated a cost of over $5 billion and the dedication of over 

17,000 FTEs to this effort. 

We consider, it difficult to overstate the impact that 

applying PSD requirements literally to GHG sources as of January 

2, 2011, without tailoring, would have on permitting 

authorities, on the PSD program, and, more broadly, on economic 

development. The number of PSD permits that would be required 

from such an approach is so far beyond what has ever been seen 

in that program that it is difficult to develop a meaningful 

picture of what the permitting program would look like, except 

to say that throughout the country, PSD permit issuance would be 

unable to keep up with the flood of incoming applications, 

resulting in delays, at the outset, would be at least a decade 

or longer, and would only grow worse over time as each year, the 

number of new permit applications would exceed permitting 

authority resources for that year. Because PSD is a 

preconstruction program, during this time, tens of thousands of 

sources each year would be prevented from constructing or 

modifying. In fact, it is reasonable to assume that many of 

those sources will be forced altogether to abandon plans to 

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future

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construct or modify. This can be expected to be true for 

virtually all PSD applicants, from the small commercial and 

residential sources to the large industrial sources. As a 

result, a literal application of the PSD applicability 

provisions to GHG sources would have the effect of a virtual

nationwide construction ban extending for years, with all of the 

adverse effects that this would have on economic development. 

The only possible remedies for this dismal scenario would 

be for permitting authorities to increase their PSD funding by 

over 100-fold, from $12 million to over $1.5 billion, or the 

development by EPA and the permitting authorities of 

streamlining techniques. But it is not possible for permitting 

authorities to increase their funding to those levels or 

anything close to them in the foreseeable future, partly because 

of the sheer magnitude of those levels and partly because of the 

financial challenges that states currently face. And, for the 

reasons discussed later, although streamlining offers genuine 

promise to improve the manageability of the PSD workload, 

streamlining cannot do so in the very near term and, in any 

event, the extent to which it can do so has not yet come into 

focus. 

So clear are at least the broad outlines of this picture 

that EPA did not receive any substantive comments arguing that 

Deleted: simply inconceivable 

that 

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Deleted: States

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permitting authorities could in fact administer the PSD program 

with the applicability requirements applied literally to GHG 

sources beginning in the very near future.43 Every permitting 

authority that addressed this issue in their comments on the 

proposed GHG Tailoring Rule stated unequivocally that it could 

not administer the PSD program at the statutory levels. To cite 

a few examples (each of which considered both the PSD and title 

V programs together): NACAA, which represents air pollution 

control agencies in 53 states and territories, stated it 

“...agrees with the EPA that immediately attempting to implement 

the PSD and title V programs using the statutory thresholds 

meets the test for invoking the administrative necessity and 

absurd results doctrines.” Similarly, the California Air 

Resources Board stated that it “...concurs with the United States. 

EPA that if more appropriate applicability thresholds [as 

opposed to the statutory thresholds] are not set for GHG it will 

not be administratively possible to implement these [the PSD and 

tile V] permitting programs.” All other state and local 

permitting agencies that commented on the proposed tailoring 

provided similar comments that they would not have the adequate 

staff capacity or resources to be able to successfully

 43 EPA did receive comments that asserted in conclusory 

fashion that permitting authorities could administer the 100/250 

tpy levels. 

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New

Deleted: For example,

Deleted: provided comments on 

the proposed GHG tailoring 

rule that 

Deleted: in their comments on 

the proposed tailoring rule 

Deleted: .S

Deleted: ”. 

Deleted: successively

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administer their permitting programs with the addition of GHG 

emission sources at the statutory thresholds for PSD and title 

V. 

It is the many-year delays in permit issuance and the 

consequent chilling of economic development that provide perhaps 

the clearest indication that applying the PSD applicability 

provisions to GHG sources without tailoring produces absurd 

results. These effects would undermine one of Congress’s 

central purposes in establishing the PSD program, which was to 

promote development in clean air areas by large industrial 

sources (as long as they included environmental safeguards). As 

discussed previously, this goal is manifest in the structure of 

the PSD provisions, and Congress even went so far as to make 

this goal explicit in the purposes section of the PSD 

provisions. But even if Congress had not been so clear, it is 

inconceivable that Congress could have intended the PSD program 

to be applied in a way that would cause such damage to the 

national economy. 

Moreover, at the present time, there is little 

environmental benefit in subjecting large numbers of small GHG 

sources to PSD permitting requirements. They represent a 

relatively small share of the GHG inventory and the control 

options available to them, at present, are limited. As a 

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result, approaches other than source-by-source permitting 

presently offer more promise for generating emissions reductions 

in an efficient manner. These approaches, which may be 

developed through both federal and state efforts, include 

requirements, incentives, and educational outreach to promote 

efficiency improvements to boilers and furnaces and energy 

efficient operations, including, for example, weatherization 

programs. 

 For all these reasons, interpreting the definition of 

“major emitting facility” and “modification” literally -- that 

is, as EPA has interpreted them more narrowly, but without 

tailoring – would produce results that are not be consonant 

with, and, in fact, would severely undermine, Congress’s purpose

for the PSD program. These results may fairly be characterized 

as the type of absurd results that support our view that the 

literal terms of the PSD applicability provisions do not 

indicate congressional intent for how those provisions should 

applied to GHG sources. 

b. Congressonal Intent for the Applicability Provisions

(1) Congressional Intent for Whether and How PSD Applies to GHG 

Sources

 46 It should be noted that strictly speaking, we do not, in 

our drafting of the regulatory revisions that are part of this 

Deleted: ,

Deleted: Federal and State

Deleted: narrowed it

Deleted: congressional intent

Deleted: s

Deleted: EPA’s reconciliation 

of applicability provisions 

with congressional intent

Deleted: EPA may tailor the 

definition of “major 

emitting facility” as 

applied to GHG sources 

because doing so best 

effectuates congressional 

intent, or at least, 

constitutes a reasonable 

construct of the statutory 

provisions.44 This 

tailoring will allow a 

window of time for EPA and 

the permitting authorities 

to develop methods to 

streamline PSD requirements 

and to ramp up permitting 

authority resources, which 

will allow for an orderly 

expansion of the PSD program 

to cover more GHG sources 

over time in a way that is 

manageable for both source 

and permitting authority.¶

Deleted: intent as applied to 

PSD applicability to GHG 

sources
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Several of the PSD provisions and statements in the 

legislative history are particularly important in determining 

whether and how the PSD program should apply to GHG sources, as 

discussed elsewhere: (i) The applicability provisions, under 

CAA section 165(a) and 169(1). These provisions are written

broadly, and although, as we explain above, they cannot be read 

literally to apply to GHG sources at or above the 100/250 tpy, 

they nevertheless can be read to indicate that directionally, 

Congress intended that PSD be applied inclusively. (ii) The 

various PSD provisions that identify the pollutants subject to

PSD. Compare, e.g., CAA sections 162, 163, 164, 165(a)(3), 

165(d)(2), 165(e), and 166 (NAAQS pollutants) with CAA 

165(a)(3)(C), 165(a)(4) (other pollutants). These provisions 

indicate that a major purpose of the PSD program is to control 

NAAQS pollutants, but that the program also covers non-NAAQS 

pollutants. (iii) The requirement that permitting authorities 

act on PSD applications within 1 year. CAA section 165(c). 

This provision indicates that Congress anticipated the PSD 

 

Deleted: To determine 

Deleted: it is important 

first to ascertain what 

would be congressional 

intent for applying the 

program to GHG sources. 

Congress wrote the 

applicability provisions 

broadly,45 so that by their 

terms they would sweep in 

sources of many types of 

pollutants, but most of the 

PSD provisions and the 

legislative history indicate 

that Congress was primarily 

focused on NAAQS pollutants. 

Even so, nothing in 

statutory provisions provide 

conclusively that GHG 

emissions -- or other nonNAAQS pollutants – when 

emitted in the appropriate 

quantity may never trigger 

PSD applicability, and 

nothing in the legislative 

history indicates that 

Congress intended such a 

result. In addition, it is 

clear that Congress expected 

PSD to be limited to large 

industrial sources – which 

are the sources whose 

emissions are most important 

for air quality purposes -- 

but no provision explicitly 

imposes that limitation. 

Congress’s reasoning was 

that large industrial 

sources
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program would be of a size that would allow permitting 

authorities to meet this deadline. (iv) The purpose provision. 

CAA section 160. This provision makes clear that PSD is 

designed both to protect public health and welfare and to 

promote economic growth. (v) In addition, we consider important 

the legislative history indicating the Congress intended PSD to 

apply to large industrial sources because they were the primary 

source of the air pollution problems and they have the resources 

to manage the demands of the PSD permitting process; and that, 

by the same token, Congress expected that small sources would 

not be subject to PSD. The legislative history does not 

specifically mention GHG sources. 

Looking at these provisions and the legislative history 

together, we think Congress can be said to have intended that 

the PSD program apply to GHG sources as a general matter. The 

most important indication of congressional intent in this regard 

is the applicability provisions, which provide, in part, that 

PSD applies to (i) “any ... source[ that] emit[s], or ha[s] the 

potential to emit [the specified quantity] of any air 

pollutant,” CAA section 169(1); and (ii) to any such source that 

undertakes a physical or operational change that “increases the 

amount of any air pollutant emitted.” CAA section 169(2)(C), 

111(a)(4). These terms are quite broad, and should be read to 
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include GHG sources and GHGs. See Massachusetts v. EPA, 549 

U.S. 497, 533 (2007) (“Because greenhouse gases fit well within 

the Clean Air Act's capacious definition of ‘air pollutant,’ we 

hold that EPA has the statutory authority to regulate the 

emission of such gases from new motor vehicles.”). Moreover, 

including GHG sources – under certain circumstances – is 

consistent with the PSD provisions that refer to other 

pollutants, establish the time-frame for acting on PSD 

applications, and establish the overall purpose of the program. 

In addition, including GHG sources – again, under certain 

circumstances -- is consistent with the legislative history that 

PSD be limited to sources that cause a meaningful part of the 

air pollution problem and have the resources to manage the PSD 

requirements. No PSD provision explicitly imposes any 

limitation of PSD to large industrial sources, and Congress’s 

reasoning for focusing on large industrial sources – which was 

that these sources are best suited to handle the resourceintensive analyses required by the PSD program – could extend to 

GHG sources under certain circumstances (that is, large sources 

first, and smaller sources after streamlining methods are 

developed). Similarly, as discussed previously, it is 

reasonable to read into Congress’s intent that the PSD program 

be limited to a size that permitting authorities would be able 

Deleted: , but it is 

conceivable that under 

certain circumstances, other 

sources could manage the PSD 

requirements as well. 

Finally, 
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to administer, but it is consistent with that reading to 

recognize that the permitting authorities could take certain 

steps – including adoption of streamlining measures and ramping 

up resources – that would allow them to handle a higher volume 

of permitting. Finally, we find nothing in the PSD provisions 

or legislative history that would indicate congressional intent 

to exclude GHG sources. Accordingly, at present, we believe 

that Congress must be said to have intended an affirmative 

response for whether PSD applies to sources of GHGs as a general 

matter. 

As to how PSD applies to GHG sources, although, for reasons 

discussed above, the 100/250 tpy threshold provision, which 

establishes the scope of PSD applicability, should not be read 

as applying literally to GHG sources -- and as a result, the 

applicability provision as a whole cannot be said to have a 

plain meaning as to the scope of coverage of GHG sources -- we 

believe that the applicability provisions and legislative 

history nevertheless indicate a congressional intent for how PSD 

should apply to GHG sources. That is to apply PSD to as many 

sources as possible as quickly as possible, at least to a 

certain point. We believe that this flows logically from the 

inclusive direction of the applicability provision, combined 

with the legislative history that focuses on Congress’s desire 

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control, Don't adjust space between

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numbers

Deleted: ¶

Deleted: congressional intent 

may be characterized as 

applying PSD to sources of 

any pollutants that are 

subject to regulation 

Deleted: long as those 

sources can reasonably be 

expected to manage PSD’s 

requirements and as long as 

the resulting numbers of 

permits can be reasonably 

accommodated by permitting 

authorities. 

Deleted: a result

Deleted: described above, we 

believe that it is not 

consonant with congressional 

intent to apply the PSD 

program to GHG sources at 

the 100/250 tpy level as 

soon as January 2, 2011, 

when GHGs become subject to 

regulation through the 

light-duty vehicle rule. 

However, it is consonant 

with congressional intent to 

apply the PSD program to GHG 

sources on a schedule that 

begins with the largest GHG 

sources and gradually 

includes smaller sources 

over time. Thus, under this 

view, the tailoring approach 

is justified under Chevron 

step 1. However, even under 

this view of congressional 

intent, we are not certain 

at present whether 

congressional intent can be 

said to be clear that the 

smallest of the GHG sources 

– those emitting at or near 

the statutory thresholds – 

should be included in the 

PSD program. As noted 

elsewhere, we may explore 

this issue further in 

subsequent rulemaking
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to include in the PSD program sources that have the resources to 

comply with the requirements and, as the Court in Alabama Power 

recognized, Congress’s concern about administrability. That is, 

at first, PSD may apply to the largest GHG sources because they 

may be expected to have the resources to comply with PSD’s 

requirements and permitting authorities may be expected to 

accommodate those sources; and over time, with streamlining and 

increases in permitting authority resources, PSD may apply to 

more GHG sources. As discussed later, the tailoring approach is 

consistent with congressional intent in this regard. 

On the other hand, if Congress cannot be said to have 

expressed an intent as to the manner and scope of PSD 

applicability to GHG sources, then, under Chevron step 2, EPA 

may apply a reasonable interpretation of the applicability 

provisions to determine the scope of coverage of GHG sources 

that is consistent with the statutory requirements. The 

Tailoring Rule is a reasonable interpretation under Chevron step 

2. It is consistent with (i) the provisions described above 

concerning which pollutants the PSD provisions cover and the 

timetable for permitting authority action on PSD applications; 

(ii) the purpose provisions of PSD, and the accompanying 

legislative history, because it protects public health and 

welfare without inhibiting economic development; and (iii) the 

Deleted: On the other hand, 

we recognize that it may 

also be concluded that 

congressional intent with 

respect to applying PSD to 

the entire universe of GHG 

sources is unclear. Under 

these circumstances, the 

tailoring approach is 

justifiable under Chevron 

step 2 as a reasonable 

interpretation of the 

statutory requirments. ¶

(2) Criteria for 

establishing phase-in 

schedule¶

The phase-in schedule 
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legislative history indicating Congress intended that PSD be 

limited to sources that cause a meaningful part of the problem 

and can manage its requirements, because it will expand PSD’s 

applicability only after streamlining methods and greater 

permitting authority resources will allow for such an expansion 

in an orderly manner.

There is a remaining question about congressional intent 

for the applicability of PSD to GHG sources, and that is whether 

Congress expressed an intent as to whether PSD applies to the 

smallest of GHG sources, which are those at or near the 100/250 

tpy statutory thresholds. To answer this question, we must 

consider several things that may point in different directions, 

or that carry significant uncertainty, among them: (i) The 

applicability provisions do include those limits, although, as 

we have described previously, it would be an absurd result to 

impose them at the present time. (ii) The legislative history 

makes clear that Congress did not expect that very small sources 

would be included in the PSD program. (iii) It is difficult to 

foresee the extent of streamlining measures.

In this action, it is not necessary to come to a decision 

as to whether, under Chevron step 1, Congress intended that PSD 

apply, or not apply, to GHG sources as low as the statutory 

levels, or whether, if Congress expressed no clear intent on 
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that question, it is reasonable under Chevron step 2 to apply 

PSD to GHG sources at that level, all within the context of the 

tailoring approach. In this rulemaking, we promulgate steps 

that cover larger sources and we provide that we will not apply 

PSD to sources below the 50,000/50,000 tpy CO2e level for at 

least the first 6 years. Because there is no need to come to 

decisions concerning the smaller sources in this rulemaking, we 

intend to consider them further, along with the legal issues 

concerning congressional intent, in the subsequent rulemaking 

that we commit to doing as part of this action. 

(2) Criteria for Establishing Phase-in Schedule

The specific phase-in schedule under the tailoring approach 

will depend on several things. The first is our progress in 

developing streamlining methods that will render the permitting 

authority workload more manageable by taking some sources off 

the table (through regulations or guidance interpreting 

“potential to emit”), and by allowing for more efficient permit 

processing (through general permits and presumptive BACT). At 

the same time, streamlining techniques will lower permitting 

costs to sources or even eliminate some sources’ obligations to 

obtain permits altogether. The second is the time that 

permitting authorities need to ramp up their resources in an 

orderly and efficient manner to manage the additional workload. 
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The third is information we have as to the sources’ abilities to 

meet the requirements of the PSD program and the permitting 

authorities’ ability to process permits in a timely fashion. 

That information will be based on the real-world experience the 

permitting authorities will accumulate as they proceed to 

process permit application for the larger GHG sources. 

Thus, under our present approach, we will develop 

streamlining techniques, we expect the permitting authorities to 

ramp up resources in response to the additional demands placed 

upon them in the first two steps, and we will gather real worldinformation about the GHG permitting process; and based on all 

that, we will address expanding the PSD program in a step-bystep fashion to include more sources over time. We intend to 

follow this process to establish both the PSD applicability 

thresholds and, as we describe next, the significance levels. 

(3) Criteria for Establishing Significance Levels46

 The criteria for establishing the significance levels are 

the same as for establishing the “major emitting facility”

thresholds. As noted previously, under the applicable CAA 

sections, any physical or operational change at a stationary 

source that “increases the amount of any air pollutant emitted 

by such source” or that results in the emission of a new 

pollutant is treated as a “modification” that is subject to PSD 

Deleted: expand 

Deleted: establishing 

significance levels¶

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requirements. Although the CAA, by its terms, treats as an 

“increase[]” any amount of emissions that is greater than zero, 

the D.C. Circuit held in Alabama Power v. Costle that EPA may 

establish a threshold – called the significance level – on de 

minimis grounds for the amount of any particular pollutant that 

may be increased. 636 F.2d at 400. 

Of particular importance, the Court in Alabama Power 

indicated that EPA may rely on administrative considerations to 

establish significance levels. Id. To reiterate, the Court 

held that “EPA does have discretion, in administering the 

statute’s ‘modification’ provision, to exempt from PSD review 

some emission increases on grounds of de minimis or 

administrative necessity.” 636 F.2d at 400. The Court added a 

more detailed exposition of its views in a subsequent part of 

its opinion, where it discussed the BACT provision, under CAA 

section 165(a)(4), and the Court made clear that those views 

applied as well to the “modification” provision. There, the 

Court invalidated an EPA regulation that established a 100- and 

250-tpy exemption from the BACT requirement. Both the BACT 

provision and the modification provision apply by their terms to 

all emissions from a source, but the Court stated that each 

provision must be read to incorporate an exemption based on de 

minimis or administrative considerations, and explained:

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We understand that the application of BACT 

requirements to the emission of all pollutants from a 

new facility, no matter how miniscule some may be, 

could impose severe administrative burdens on EPA, as 

well as severe economic burdens on the construction of 

new facilities. But the proper way to resolve this 

difficulty is to define a de minimis standard 

rationally designed to alleviate severe administrative 

burdens, not to extend the statutory 100 or 250-ton 

threshold to a context where Congress clearly did not 

apply it. Just as for the applicability of PSD to 

modifications, the de minimis exemption must be 

designed with the specific administrative burdens and 

specific regulatory context in mind. This the Agency 

has failed to do. We do not hold that 100 tons per 

year necessarily exceeds a permissible de minimis

level; only that the Agency must follow a rational 

approach to determine what level of emission is a de 

minimis amount.

A rational approach would consider the 

administrative burden with respect to each statutory 

context: what level of emission is de minimis for 

modification, what level de minimis for application of 

BACT. Concerning the application of BACT, a rational 

approach would consider whether the de minimis

threshold should vary depending on the specific 

pollutant and the danger posed by increases in its 

emission. The Agency should look at the degree of 

administrative burden posed by enforcement at various 

de minimis threshold levels. It is relevant that our 

decision requires the Agency, in its evaluation of 

emissions of facilities, to take into account the 

facility's air pollution controls. It may also be 

relevant, though it is certainly not controlling, that 

Congress made a judgment in the Act that new 

facilities emitting less than 100 or 250 tons per year 

are not sizeable enough to warrant PSD review.

Id. at 405. As just quoted, the Court acknowledged the 100 and 

250 tpy thresholds for a major emitting facility, and did not 

indicate whether the modification exemption level could exceed 
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those statutory levels, but nevertheless, the Court made clear 

that EPA may “consider the administrative burden” associated 

with modifications to establish an exemption level for 

modifications. 

EPA has established significance levels for various 

pollutants, generally relying on a de minimis basis. See, e.g., 

45 FR 52,676, 52,705 – 52,710 (August 7, 1980). In these 

actions, EPA generally established the level based on the 

triviality of the amount of emissions excluded. To this point, 

we have not attempted to determine de minimis – that is, trivial 

-- levels for GHGs. Instead, in this rulemaking, EPA is 

establishing a phase-in schedule for significance levels based 

on the Chevron framework, accounting for the “absurd results,” 

“administrative necessity,” and “one-step-at-a-time” doctrines. 

It is not necessary to establish a permanent de minimis level in 

this rulemaking. For one thing, the Court in Alabama Power

explicitly authorized an administrative basis for significance 

levels. Moreover, were EPA to establish a de minimis level, 

that amount could be below – perhaps even well below – the 

“major emitting facility” thresholds established in this 

rulemaking on grounds of “administrative necessity” and the 

other doctrines. Accordingly, at present, if we were to 

establish a permanent significance level on a de minimis basis,

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Underline

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Deleted: and has 

Deleted: established

Deleted: for them

Deleted: Fed. Reg.

Deleted: ) In addition, the 

Court in Alabama Power 

authorized EPA to use an 

“administrative necessity” 

basis for establishing 

significance levels. 636 

F.2d. at 400.¶

Deleted: today’s

Deleted: ” doctrine or, 

alternatively, as discussed 

below, the 

Deleted: ” doctrine

Deleted: today’s rulemaking, 

and attempting to do so 

would give rise to 

administrability problems. 

This is because we are 

considering establishing the 

Deleted: threshold for step 

3 as low as the 50,000 tpy 

CO2e level, as discussed 

elsewhere, and of course, we 

could eventually establish a 

lower level. Our present 

view is that we do not have 

the authority to establish 

the de minimis level higher 

than the major emitting 

facility threshold
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that level could result in too many small sources being required 

to submit permit applications while the phase-in is occurring. 

This would give rise to the same problems concerning undue costs 

to the sources and administrative burdens for the permitting 

authorities for which we are fashioning a remedy. Accordingly, 

the significance levels we establish with this action are the 

lowest levels that sources and permitting authorities can 

reasonably be expected to implement at the present time in light 

of the costs to the sources and the administrative burdens to 

the permitting authorities. 

c. Other Possible Approaches to Reconciling Literal Reading of 

PSD Applicability Provisions and Congressional Intent

Commenters have suggested another approach to reconciling 

the inconsistency between the definition of “major emitting 

facility” and congressional intent. They urge that the “major 

emitting facility” definition should be applied so that only 

sources that emit NAAQS pollutants, for which the area is 

designated attainment or unclassifiable, in the requisite 

quantities would be subject to PSD, and sources would not be 

subject to PSD based solely on their emissions of non-NAAQS 

pollutants or a NAAQS pollutant for which an area has been 

designated nonattainment. Some commenters argue that this 

approach is mandated by several of the PSD provisions, read 

Deleted: would be relatively 

low and would

Deleted: submitting

Deleted: 

Deleted: Our rationale for 

the implementation schedule 

is based on the combined 

burdens for both PSD and 

Title permitting purposes. 

As a result, we discuss our 

rationale below, after first 

describing the “absurd 

results” basis for our 

action concerning title V 

applicability to GHG 

sources.¶

Deleted: . 

Deleted: possible approaches 

to reconciling literal 

reading of PSD applicability 

provisions and congressional 

intent

Deleted: In addition, we 

recognize that commenters

Deleted: other approaches

Deleted: For example, some 

commenters urged
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together or at least that the relevant statutory provisions are 

ambiguous and that this approach is a reasonable reading of 

them. Under this approach, we would not need to phase in the 

application of PSD by lowering the applicability threshold for 

GHG emitters. 

Specifically, many commenters have questioned whether EPA 

has the authority to regulate GHGs under the PSD provisions. 

Although the specific lines of reasoning vary somewhat from one 

commenter to another, in general, they based their arguments 

largely on CAA sections 161 and 165(a). Under CAA section 161: 

In accordance with the policy of section 101(b)(1), 

each applicable implementation plan shall contain 

emission limitations and such other measures as may be 

necessary, as determined under regulations promulgated 

under this part, to prevent significant deterioration 

of air quality in each region (or portion thereof) 

designated pursuant to section 107 as attainment or 

unclassifiable. 

Commenters point out that section 107 applies only to NAAQS 

pollutants and directs that areas be designated as attainment, 

nonattainment, or unclassifiable on a pollutant-by-pollutant 

basis. Under CAA section 165(a), a “major emitting facility” 

 48 We find no support for the proposition raised by some 

commenters that this provision is limited to “NAAQs” pollutants. 

To the contrary, “under this chapter” unambiguous signals an 

intent to cover any pollutant regulated under the Act. Had 

Congress intended a narrower focus, they would have specified 

“any NAAQs pollutant” or any pollutant subject to regulation 

under this Part (PSD).

Formatted: Font: (Default) Courier

New

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New

Deleted: 

Deleted: )”

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Deleted: 

Deleted: varied

Deleted: )47.

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cannot be constructed “in any area to which this part applies” 

unless it meets certain requirements. According to some 

commenters, these provisions, read together, limit PSD’s 

applications to only for NAAQS pollutants that are emitted from 

sources in areas that are designated attainment or 

unclassifiable for those pollutants. Other comments make a 

similar point, except state that PSD applies more broadly to 

pollutants with a local, ambient impact.

Some commenters go on to take the position that NAAQS 

pollutants for which the area is designated attainment or 

unclassifiable are the only pollutants that can be regulated 

under any provision of the PSD requirements; while others take 

the position that once PSD is triggered for a source on the 

basis of its NAAQS pollutants, then other, non-NAAQS, pollutants 

may be regulated under certain PSD provisions, in particular, 

the BACT provision under CAA section 165(a)(4). These 

commenters agree, however, that emissions of GHGs, by 

themselves, cannot trigger PSD applicability. Finally, some 

commenters state that even if the PSD provisions cannot be read 

by their terms to preclude GHGs from triggering PSD, then they 

can be read to authorize EPA to determine that GHG emissions do

not trigger PSD. 

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Deleted: being triggered 

Deleted: other 

Deleted: 

Deleted: should
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We recognize, as we have said elsewhere, that a major

purpose of the PSD provisions is to regulate emissions of NAAQS 

pollutants in an area that is designated attainment or 

unclassifiable for those pollutants. However, we do not read 

CAA sections 161 and the “in any area to which this part 

applies” clause in 165(a), in the context of the PSD 

applicability provisions, as limiting PSD applicability to those 

pollutants. The key PSD applicability provisions are found in 

sections 165(a) and 169(1). Section 165(a) states, “No major 

emitting facility on which construction is commenced after 

August 7, 1977, may be constructed in any area to which this 

part applies unless [certain requirements are met]. A “major 

emitting facility” is defined, under CAA section 169(1), as “any 

... stationary source[] which emit[s], or ha[s] the potential to 

emit, one hundred [or, depending on the source category, two 

hundred fifty] tons per year or more of any air pollutant.” As 

discussed elsewhere, EPA has long interpreted the term “any air 

pollutant” to refer to “any air pollutant subject to regulation 

under the CAA,” and for present purposes, will continue to read 

the “subject to regulation” phrase into that term. 

Although section 165(a) makes clear that the PSD 

requirements apply only to sources located in areas designated 

attainment or unclassifiable, it does not, by its terms, state 

Deleted: primary 

Deleted: read 

Deleted: with

Deleted: provision is 

Deleted: section 165(a), 

which 

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that the PSD requirements apply only to pollutants for which the 

area is designated attainment or unclassifiable. Rather, 165(a) 

explicitly states that the PSD requirements apply more broadly 

to any pollutant that is subject to regulation. Moreover, two 

other requirements in CAA section 165(a) also apply to air

pollutants broadly. Under CAA section 165(a)(3), one of the 

requirements for securing a preconstruction permit is to 

demonstrate that the source’s emissions “will not cause, or 

contribute to, air pollution in excess of any (A) maximum 

allowable increase or maximum allowable concentration for any 

pollutant in any area [to which the PSD requirements apply], (B) 

[NAAQS] in any air quality control region, or (C) any other 

applicable emission standard or standard of performance under 

this chapter.” As just quoted, subparagraph (C), by its terms 

clearly applies to non-NAAQS pollutants. This is because it 

refers to (i) “any other applicable emission standard,” which 

distinguishes it from subparagraph (B) and therefore from NAAQS 

pollutants; and (ii) “any ... standard of performance under this 

chapter,” which refers to standards of performance under section 

111, several of which are for non-NAAQS pollutants. See, e.g., 

40 CFR 60.33c(a) “municipal solid waste landfill emissions.” By 

the same token, CAA section 110(j) specifically contemplates 

that a source required to hold a permit under title I of the 

Deleted: applies, by its 

terms,

Deleted: [NAAQS increment 

Deleted: Subparagraph (B), by 

its terms, applies to NAAQS 

pollutants for which the 

area is designated 

nonattainment, and therefore 

are outside of the PSD 

program. Most importantly

Deleted: and its 

differentiation from NAAQS 

pollutants under 

subparagraph (C), 

Deleted: For example, by its 

terms this provision 

requires a demonstration 

that a landfill seeking a 

PSD permit will comply with 

emission limitations for 
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Clean Air Act, which includes a PSD permit, demonstrate that the 

source complies with “standards of performance,” which may 

include requirements for pollutants other than NAAQS. 

In addition, CAA section 163(a)(4) includes as a PSD 

requirement that “the proposed facility is subject to the best 

available control technology for each pollutant subject to 

regulation under this chapter emitted from, or which results 

from, such facility. Section 163(a)(4)’s broad reference to 

“each pollutant subject to regulation under this chapter” 

clearly indicates that it applies to non-NAAQS pollutants, as 

long as they are regulated under other provisions of the Act.48 

The D.C. Circuit, in Alabama Power v. Costle, 636 F.2d 323, 361 

n.90 (D.C. Cir. 1980) indicated that, under the law applicable 

at the time the Court handed down the decision in 1980, PSD 

Deleted: strongly 

Deleted: Indeed, the very 

existence of this provision 

makes clear that Congress 

knew how to limited the 

scope of “any air pollutant” 

when it intended to do so.
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applies to hazardous air pollutants. 49

In addition, PSD requirements are part of SIPs, and 

although SIPs generally are limited to provisions that implement 

the NAAQS, and therefore generally are limited to controlling 

NAAQS pollutants (or non-NAAQS pollutants that affect ambient 

air quality), see generally CAA section 110, Congress explicitly 

required SIPs to include requirements to protect visibility, 

under CAA section 169A-B. See CAA sections 110(a)(2)(D)(i)(II), 

169A(b)(2)(A). Congress took much the same approach with the 

PSD program, which was to require that PSD requirements be 

included in the SIPs, but to explicitly require that PSD apply 

to non-NAAQS pollutants. 

These provisions – sections 165(a)(3), 165(a)(4), and 

110(j) -- all indicate by their terms that PSD requirements 

apply to non-NAAQS pollutants. As such, they lend credence to 

our view that Congress intended the PSD applicability provisions 

to include GHG sources. At the very least, they demonstrate 

that Congress certainly knew how to specifically describe 

certain air pollutants – e.g., “air pollution in excess of ... any 

other applicable emission standard or standard of performance 

 49 In the 1990 CAA Amendments, Congress added section 

112(b)(6), which provides that PSD “shall not apply to 

pollutants listed under this section,” that is, hazardous air 

pollutants. 
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under this chapter,” CAA section 165(a)(3)(C) – which indicates 

that its decision not to specifically describe air pollutants in 

the applicability provisions suggests an intent to cover air 

pollutants broadly. 

To return to sections 161 and the “in any area to which 

this part applies” phase in 165(a), which commenters rely on as 

the cornerstone of their argument, commenters in effect take the 

position that Congress intended the geographic references in 

these provisions – that is, the references to areas designated 

as attainment or unclassifiable – to limit the scope of the 

permitting provisions. We think it unpersuasive that Congress 

would have taken such an indirect, and silently implied, route 

to limit the scope of the permitting provisions. As noted 

previously, the permitting provisions apply broadly by their 

terms. Had Congress intended to limit PSD permitting in the 

manner urged by commenters, it certainly could have done so 

directly, such as by limiting PSD permitting to “any pollutant 

for which an area is designated attainment or unclassifiable.” 

Indeed, Congress did so in other PSD provisions, discussed 

previously. Similarly, in other sections of the CAA, Congress 

also directly limited the scope of pollutant applicability by 

specifying which pollutants are or are not subject to the 

provision. See, e.g., 111(d) (performance standards for 

Formatted: Underline

Deleted: , which, as 

Deleted: above, 

Deleted: in other sections of 

the CAA, 

Deleted: limit 

Deleted: specifiying
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existing sources apply only to pollutants other than NAAQS or 

HAPs), 112(a)(1) (applying air toxics requirements in section 

112 to sources that emit above the specified tonnage thresholds 

of “hazardous air pollutants”). 

In addition, although section 161 requires that SIPs 

contain emission limitations and other measures as necessary to 

prevent significant deterioration in areas designated as 

attainment or unclassifiable, it does not by its terms limit 

SIPs to only those measures. 

Most broadly, we read the PSD provisions and their 

legislative history to evidence Congress’s intent that PSD apply 

throughout the country to large sources that undertake new 

construction or modifications, and that Congress’s overall 

purpose was to assure that, as the industrial stock of the 

nation turned over, it would become cleaner for all air 

pollutants emitted. GHG sources, as a general matter, fit 

readily into this overall vision. At the time that Congress 

enacted the PSD provisions in 1977, every area of the nation was 

designated attainment or unclassifiable for at least one air 

pollutant, and that has remained the case to the present time. 

Accordingly, at all times, PSD has applied in every area of the 

country. The PSD requirements clearly cover all air pollutants 

emitted by the source, and provide a process for reviewing those 

Deleted: NAAQs or hazardous 

air pollutants

Deleted: Moreover, section 

161 should be read in 

conjunction with section 

110(a)(2)(C), which 

establishes the basic 

requirement that SIPs 

include PSD requirements. 

Section 110(a)(2)(C) 

provides that each SIP shall 

--

Deleted: Include a program to 

provide for the enforcement 

of the measures described in 

subparagraph (A), and 

regulation of the 

modification and 

construction of any 

stationary source within the 

areas covered by the plan as 

necessary to assure that 

[NAAQS] are achieve, 

including a permit program 

as required in parts C and D 

of this subchapter. ¶

¶

Subparagraph (A), in turn, 

requires SIPs to include 

“enforceable emission 

limitations and other 

control measures, means, or 

techniques ... as may be 

necessary or appropriate to 

meet the applicable 

requirements of this 

chapter”. It is clear from 

subparagraph (C) of section 

Deleted: in conjunction with 

subparagraph (A), that SIPs 

may contain

Deleted: to meet requirements 

other than those related to 

the NAAQS (that is, 

subparagraph (A) requires 

control measures “to meet 

the applicable requirements 

Deleted: that SIPs must 

include “a permit program as 

required in part[] C.” That 

permit program, in turn, 

must include the 

requirements in section 

Deleted: addition in the 1990 

CAA Amendments

Deleted: limitation in 

section 112(b)(6) that “The 

provisions of part C of this 

subchapter (prevention of 

significant deterioration) 

shall not apply to 

... [68]

... [69]

... [71]

... [70]
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emissions and determining BACT for them under CAA section 

165(a)(4). It is true that at the time Congress adopted the PSD 

provisions, it was primarily concerned about the NAAQS 

pollutants – or, as some commenters assert, pollutants with 

local, ambient impact -- because those pollutants represented a 

major component of the air pollution problems it was aware of 

and was addressing. But its overall purpose was broad enough to 

cover additional pollutants; the process it enacted for 

establishing BACT was broad enough to encompass additional

pollutants; and the applicability provisions it established were 

phrased broadly enough to encompass additional pollutants, see

section 169(1). As a result, we believe that the PSD 

applicability provisions, which, again, refer to, as we have 

interpreted them, “any air pollutant [subject to regulation 

under the CAA]” should be seen as “capacious” and therefore 

encompass GHG sources, in much the same manner as the U.S. 

Supreme Court viewed the definition of “air pollutant” to be 

“capacious” and therefore encompass GHGs. Massachusetts v. EPA, 

549 U.S. 497, 533 (2007). 

In addition, it should not be overlooked that we have 

applied PSD to non-NAAQS pollutants since the inception of the 

program over 30 years ago. For example, prior to the 1990 CAA 

Amendments, PSD applied to HAPs regulated under CAA section 112; 

Deleted: hazardous air 

pollutants
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and over the years, EPA has established significance levels for 

fluorides, sulfuric acid mist, hydrogen sulfide, total reduced 

sulfur, reduced sulfur compounds, municipal waste combustor 

organics, municipal waste combustor metals, municipal waste 

combustor acid gases, and municipal solid waste landfill 

emissions, see 40 CFR 51.166(b)(23)(i); and EPA has proposed a 

significance level for ozone depleting substances. See 61 FR

38,307/2 (July 23, 1996). Of course, the basis for all these 

actions is PSD’s applicability to these non-NAAQS air 

pollutants. We are not aware that EPA’s actions in establishing 

significance levels for these pollutants gave rise to challenges 

on grounds that the PSD provisions do not apply to them. As the 

U.S. Supreme Court recently stated in upholding an EPA approach 

in another context: “While not conclusive, it surely tends to 

show that the EPA’s current practice is a reasonable and hence 

legitimate exercise of its discretion . . . that the agency has 

been proceeding in essentially this fashion for over 30 years.” 

Entergy Corp. v. Riverkeeper, Inc., 129 S.Ct. 1498, 1509 (2009) 

(citations omitted).

Finally, we note that excluding GHG sources from PSD 

applicability would create inequitable results. Consider the 

hypothetical case of two sources that construct in the same 

area, each of which emits the same amount of GHGs, and that 

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Underline

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Underline

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amount is large enough to trigger PSD applicability. Assume 

that the first one, but not the second, also emits NAAQS 

pollutants amounts large enough to trigger PSD applicability. 

If GHG sources are excluded from PSD applicability, then the 

first of those sources, but not the second, would be subject to 

PSD requirements for its GHG emissions. Similarly, consider the 

hypothetical case of two sources that emit identical amounts of 

the same NAAQS pollutant and identical amounts of GHGs, all 

amounts of which are large enough to trigger PSD applicability 

requirements. Assume that the first source constructs in an 

area that is an attainment or unclassifiable area for the NAAQS 

pollutant that it emits, and that the second source constructs 

in an area that is not an attainment or unclassifiable area for 

that NAAQS pollutant. Here again, if GHG sources are excluded 

from PSD applicability, then the first of those sources, but not 

the second, would be subject to PSD requirements for its GHG 

emissions. These results are inequitable and would create an 

uneven playing field and for this reason, too, support our view 

that the PSD applicability provisions apply to GHG sources.

Accordingly, we reject the argument that section 165 must 

be, or may reasonably be, limited in scope to pollutants for 

which an area has been designated as attainment or 

unclassifiable. Rather, the PSD applicability provision – the 
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definition of “major emitting facility” in CAA section 169(1) – 

applies by its terms (as we have interpreted them narrowly

through regulation) to sources emitting any air pollutant 

subject to regulation, and is not limited to any NAAQS air 

pollutant. Our research has not disclosed any explicit 

statements in the legislative history that Congress intended to 

limit PSD applicability to sources of NAAQS pollutants. 

6. Application of the “Absurd Results” Doctrine for the Title V 

Program 

 Having discussed the application of the Chevron

framework, taking account of the “absurd results” doctrine, for 

the PSD applicability requirements, we now turn towards applying 

the same approach to the title V applicability requirements. 

Because of the parallels between the PSD and title V

applicability provisions, much of the discussion later parallels 

the discussion previously of PSD. As with PSD, we finalize, 

with some refinements, the “absurd results” basis we proposed. 

Specifically, we are revising our regulations to limit title V 

applicability to GHG emitting sources by revising the regulatory 

term, “major source,” and although our revised regulations do 

not accord with a literal reading of the statutory provisions 

for title V applicability, which are incorporated into the 

statutory definition of “major source,” we have concluded that 

Deleted: narrowed them

Deleted: 

Deleted: We recognize, as we 

discuss at length elsewhere 

in today’s notice, that 

applying the PSD 

applicability provisions 

literally to GHG sources is 

not consistent with, and in 

fact would undermine, 

congressional intent. We 

further believe that the 

tailoring approach we adopt 

in this rulemaking most 

closely gives effect to 

congressional intent and 

therefore best reconciles 

the statutory provisions 

with congressional intent.¶

In any event, we did not 

include the NAAQS approach 

as advocated by commenters 

in our notice of proposed 

rulemaking, and so we could 

not proceed to adopt it in 

today’s final action. 

However, we are not inclined 

to reject the possibility 

that some approach other 

than the phase-in approach 

that we adopt today could 

merit further exploration 

under the “absurd results” 

doctrine. Therefore, while 

we will proceed to implement 

the approach described in 

today’s rulemaking, we 

intend to publish a 

supplemental notice of 

proposed rulemaking in the 

near future, in which we 

solicit additional comment 

on whether we have authority 

to adopt some other approach 

under the “absurd results” 

doctrine on grounds of 

consistency with 

congressional intent. If we 

decide to change our 

approach, that could have 

important ramifications for 

whether we will promulgate 

lower thresholds in step 3 

or subsequently. ¶

Deleted: absurd results” 

doctrine for the title V 

program

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Deleted: below

Deleted: above
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based on the “absurd results” doctrine, a literal adherence to 

the terms of this definition is not required. A literal 

adherence would not reflect congressional intent that title V 

apply to GHG sources as a general matter. Further, we may apply 

title V to GHG sources in a phased-in manner, as we do through 

the tailoring approach, because either congressional intent is 

clear on that issue and the tailoring approach best reflects it, 

or congressional intent is unclear and the tailoring approach is 

a reasonable interpretation of the statute. However, in this 

rulemaking, as discussed previously, it is not necessary to make 

decisions, and we do not do so, about congressional intent for 

applying title V to smaller GHG sources, that is, those that 

emit at or close to the statutory thresholds, or applying title 

V to GHG sources with “empty permits.”

 To reiterate, for convenience, the title V applicability 

provisions provide that after the effective date of a title V 

program, it is unlawful for any person to operate a "major 

source" without a title V permit, CAA §502(a), and define a 

"major source" to include "any major stationary facility or 

source of air pollutants which directly emits, or has the 

potential to emit, one hundred tons per year or more of any air 

pollutant." CAA §501(2)(B) and §302(j). 

Deleted: for title V 

applicability. Instead, we 

may limit

Deleted: applicability for 

GHG emitting sources in a 

way that is reasonably 

reflective of

Deleted: .¶
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Under the current interpretation of the title V 

applicability provision, EPA’s recent promulgation of the lightduty vehicle rule will trigger the applicability of title V for 

GHG sources at the 100 tpy threshold levels as of Jan. 2, 2011. 

This is because title V applicability hinges on the definition 

of “major source,” which, under EPA’s long-standing narrowing 

interpretation, but absent further tailoring, applies title V to 

sources of any air pollutant that is subject to regulation under 

another provision of the CAA. EPA’s promulgation of the lightduty vehicle rule means that GHGs will become subject to 

regulation on the date that the rule takes effect, which will be 

January 2, 2011. 

But absent tailoring, the January 2, 2011 trigger date for 

GHG PSD applicability will see an extraordinarily large number 

of sources -- some 6.1 million -- become subject to title V, an 

increase of over 400-fold over the 14,700 sources that currently 

are subject to title V each year. The great majority of these 

will be small commercial or residential sources. 

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Deleted: new sources 
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We believe that for many reasons, this result is contrary

to congressional intent for the title V program, and in fact 

would severely undermine what Congress sought to accomplish with 

the program. As a result, under Chevron, accounting for the 

“absurd results” doctrine, the statutory definition for “major 

source” (as EPA has already narrowed it to refer to any air 

pollutant “subject to regulation”) should not be read to apply 

to all GHG sources at or above the 100 tpy threshold as of the 

January 2, 2011 date. Rather, the definition of “major source” 

should be tailored so that it applies to GHG sources on a 

phased-in basis, with the largest sources first, as we describe 

in this rule. 

a. Congressional Intent for the Title V Program 

As we said, previously, in a similar circumstance involving 

the PSD program, applying title V requirements to GHG sources 

without tailoring the definition of “major source” – and, as 

discussed later, without streamlining the title V requirements 

or allowing for time for permitting authorities to ramp up 

resources -- would result in a program unrecognizable to the 

program that Congress intended, and one that would be flatly 

unadministrable. Without tailoring, the PSD program would 

expand from the current 14,700 sources to some 6.1 million, with 

the great majority of the sources being small commercial and 

Formatted: No underline

Deleted: anathema

Deleted: today’s 

Deleted: Applying the 

definition of “major source” 

without tailoring – that is, 

applying title V to GHG 

sources at the 100 tpy level 

without tailoring -- would 

be contrary to congressional 

intent as found in the 

statutory provisions and 

legislative history, 

especially as those 

provisions and history are 

viewed in light of the 

results that would occur 

from applying title V to 

those sources. ¶

Deleted: above

Deleted: below
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residential sources that not only have never been permitted 

before, but that in many cases have no applicable requirements 

under the CAA to include in the permit. In the next several 

sections, we will describe some of the specific ways that this 

literal application of title V would not only differ from, but 

would undermine, congressional intent. But the big picture is 

readily drawn: The influx of millions of permit applications 

would do nothing less than overwhelm the program Congress finely 

crafted for thousands of sources, with its multi-step deadlines 

measured in days and months, its multiple mandates for 

expeditious permit processing, its nuanced limitations on the 

need for permit revisions, its efforts to save smaller sources 

permit fees. Regulatory gridlock, precisely what Congress 

strove to avoid, would result. 

 Most visibly, interpreting the applicability provisions 

literally to include GHG sources at the 100/250 tpy levels would 

revise the program from what Congress envisioned in three major 

ways, the legislative history of each of which was discussed 

previously: 

• It would expand the program to cover several-hundredfold more sources than Congress anticipated 

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• It would expand the program to cover very small 

sources that Congress expected would not be included 

in the program 

• It would expand the program so that the large majority 

of sources have empty permits, that is, permits 

without applicable requirements. 

Revising the program in this way through a literal 

interpretation of the applicability provisions – without 

tailoring the applicability requirements and without 

streamlining the program requirements -- is clearly inconsistent 

with Congress’s conception of the program’s scope, and these 

inconsistencies are foundational. Most importantly, the program 

that would result would be unduly costly to sources and 

impossible for permitting authorities to implement, and 

therefore would frustrate the purposes that Congress intended to 

achieve with the program that it did design. 

As discussed previously, Congress was fully aware that with 

the title V program, it was subjecting sources and permitting 

authorities to additional costs and administrative burdens, and 

it was fully aware of concerns that absent careful design, the 

program could become a formula for regulatory gridlock. 

Determined to make the program workable, Congress crafted the 

provisions to be efficient and workable. 

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However, if title V were to apply to GHG sources at the 100 

tpy level, until EPA could develop streamlining methods, all of 

these sources newly subject to title V would need to apply for 

permits. We estimate that the commercial and residential 

sources would incur, on average, expenses of $23,370, while an 

industrial source would incur expenses of $46,350, to prepare a 

permit application and receive a permit. The great majority of 

these sources would be small commercial and residential sources 

of the type that Congress did not expect would be included in 

title V. For example, as discussed above, the legislative 

history of title V, including both the permit program under CAA 

sections 501-506 and the “small business stationary source 

technical and environmental compliance assistance program” under 

CAA section 507, indicated that Congress did not expect that 

“printers, furniture makers, dry cleaners, and millions of other 

small businesses” would become subject to title V. House 

Committee Report, H.R. 101-590, at 354. These sources generally 

do not have the potential to emit conventional pollutants at or 

above the 100 tpy threshold. However, many do have the 

potential to emit GHGs above that threshold. Many printers and 

furniture makers use a variety of combustion equipment that has 

the potential to emit at least 100 tpy CO2, and many commercial 

dry cleaners have gas-fired driers that have the potential to 

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Deleted: we estimate

Deleted: the great majority 

Deleted: them

Deleted: applicable Clean Air 

Act requirements to include
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emit at least 100 tpy of CO2. All told, there are in fact 

“millions of ... small businesses” that would become subject to 

title V. Of the 6.1 million sources that would become subject 

to title V, the great majority are small businesses. 

Moreover, the overall cost to all 6.1 million sources would 

be a staggering $49 billion. Imposing burdens of this magnitude 

on these sources – individually and in total – would of course 

be contrary to Congress’s efforts to minimize the expenses of 

title V, especially to small sources. The magnitude of the 

costs is, in a sense, heightened because a great many of these 

sources will not have applicable requirements to include in 

their permits; therefore, much of the costs will produce little 

benefit. 

 Yet, the most important reason why applying the title V 

program to GHG sources without tailoring, and before the 

development of streamlining methods, would be inconsistent with 

congressional intent, is that the resulting program would prove 

unadministrable. Adding some 6.1 million permit applications to 

the 14,700 that permitting authorities now handle would 

completely overwhelm permitting authorities, and for all 

practical purposes, bring the title V permitting process to a 

standstill. 

Formatted: documentbody

Deleted: their permits. The
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 The costs to permitting authorities of this multi-millionsource program would again be staggering. On average, and 

without streamlining, a permitting authority would expend 214 

hours, which would cost $9,844, to issue a permit to a 

commercial or residential source; and 428 hours, which would 

cost $19,688, to issue a permit to an industrial source. In 

all, permitting authorities would face over $21 billion in 

additional permitting costs each year due to GHGs, compared to 

the current program cost of $62 million each year. 

Beyond this disconnect with congressional expectations as 

to scope of the program, the extraordinarily large number of 

permit applications would overwhelm permitting authorities and 

slow their ability to process permit applications to a crawl. 

As described at proposal, the survey of permitting authorities 

conducted by NACAA found that a literal application of the title 

V applicability provisions to GHG sources would result in 

permitting delays of some 10 years. However, as we further 

noted at proposal, this estimate was based on the assumption 

that the applicability threshold would be 100 tpy actual 

emissions; in fact, the applicability threshold would be 100 tpy 

in potential to emit, which would sweep in many more sources. 

Moreover, as stated elsewhere, we currently estimate the amount 

of per-permit work hours for permitting authorities in 

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important is that 

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processing title V permit applications to be several times 

higher than what we estimated at proposal. As with PSD, such a 

program is so far beyond anything within our experience that it 

is difficult to give a meaningful estimate for how long the 

permitting process would take for each permit on average, but it 

is clear that the period would be many years longer than the 10 

years estimated by NACAA. 

In addition, applying title V to GHG sources without 

tailoring would be in tension with a specific CAA requirement, 

that of CAA § 503(c), which imposes a time limit of 18 months 

from the date of receipt of the completed permit application for 

the permitting authority to issue or deny the permit. It would 

be flatly impossible for permitting authorities to meet this 

statutory requirement if their workload increases from some 

14,700 permits to 6.1 million. Instead, as just noted, permit 

applications would face multi-year delays in obtaining their 

permits. 

Moreover, these delays would undermine the overall 

statutory design that promotes the smooth-running of the 

permitting process, and the very purpose of the title V program 

itself. As noted elsewhere, Congress intended through title V 

to facilitate sources’ compliance with their CAA obligations by 

establishing an operating permit program that requires the 

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source to combine all of its CAA requirements, and explain how 

it will assure compliance with such requirements. Congress 

established a comprehensive process to implement the operating 

permit program. Through this process, following the date that 

sources become subject to title V, they have 1 year to submit 

their permit applications. CAA §503(c). As noted, the 

permitting authority then has 18 months to issue or deny the 

permit. CAA §503(c). Permitting authorities must provide an 

opportunity for public comment and a hearing. CAA §502(b)(6). 

If the permitting authority proposes to issue the permit, the 

permitting authority must submit the permit to EPA for review, 

and notify affected states. CAA §505(a)(1). EPA then has 45 

days to review the permit and, if EPA deems it appropriate, to 

object to the permit. CAA §503(b)(1). If EPA does object, then 

the permitting authority must, within 90 days, revise it to meet 

the objections, or else EPA becomes required to issue or deny 

the permit. CAA §503(c). If EPA does not object, then, within 

60 days of the close of the 45-day review period, any person may 

petition EPA to object, and EPA must grant or deny the petition 

within 60 days. CAA §505(b)(2). This set of applicant, 

permitting authority, and EPA actions and deadlines establishes 

the process for the prompt and efficient issuance of operating 

permits for the appropriate universe of sources. 

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But at least for an initial period, until resources could 

be ramped up and streamlining methods could be developed, the 

extraordinary numbers of these permit applicants would sweep 

aside this carefully constructed program, and instead, backlog 

the permit authorities. This initial period would last for many 

years. As discussed elsewhere, it would take several it would 

take several years to develop and apply streamlining measures –

in particular, general permits – and during that time, the 

permit backlog would grow so large that it would take many more 

years for permitting authorities to catch up by raising the 

requisite funds and hiring and training the necessary employees. 

What’s more, only a small fraction of these millions of 

sources newly covered by title V will be subject to any CAA 

requirements due to their GHG emissions, and we suspect that the 

majority will not be subject to any CAA requirements at all. As 

a result, for most of these sources, although they would need to 

apply for and receive a permit, there would be no applicable 

requirements to include in the permit and thus the exercise 

would not improve compliance. 

The picture that emerges from a literal application of 

title V’s requirements to GHG sources -- at the 100 tpy level, 

beginning on January 2, 2011 – shows multi-year delays in 

issuance of all permits, for both the sources that have 

Deleted: In addition, only a 

small fraction of these 

millions of sources will be 

subject to any CAA 

requirements due to their 

GHG emissions, and we 

suspect that the majority 

will not be subject to any 

CAA requirements at all, so 

that although they would 

need to apply for and 

receive a permit, there 

would be no applicable 

requirements to include in 

the permit and thus the 

exercise would not improve 

compliance. 

Deleted: sources

Deleted: Congress’s 

Deleted: The large numbers 

involved mean that this 

Deleted: because it would 

take that long to raise the 

requisite funds and hire and 

train the necessary 

employees, as well as, as

Deleted: . Therefore,

Deleted: would ensue
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applicable requirements and that Congress clearly intended the 

program to cover, and for the millions of sources that may not 

be subject to any applicable requirements. In short, this

literal interpretation would apply title V to millions of 

sources that Congress did not intend be covered, and the ensuing 

administrative burdens – at least initially -- would impede the 

issuance of permits to the thousands or perhaps tens of 

thousands of sources that Congress did intend be covered. This 

is the type of “absurd results” from a literal application of 

statutory provisions that the courts have held should be 

avoided. And even beyond all that, the sheer magnitude of the 

numbers involved– millions of permits requiring thousands of 

FTEs at a cost to the permitting authorities of billions of 

dollars, all this beginning immediately at the time that GHGs 

become subject to regulation – makes clear that this result of a 

literal application of the title V provisions to GHG sources is 

not what Congress in fact intended or could conceivably have 

intended. 

b. EPA’s Reconciliation of Applicability Provisions With 

Congressional Intent

For the reasons just described, we should not consider the 

literal meaning of the applicability provisions to be 

determinative of congressional intent as to the applicability of 

Deleted: Thus, a

Deleted: of the title V 

threshold provisions 

Deleted: result 

Deleted: occurring

Deleted: , the

Deleted: PSD 

Deleted: reconciliation of 

Deleted: with 

Deleted: ¶

EPA has concluded that the 

impacts of applying the 

literal definition of “major 

source” to GHG sources are 

inconsistent with, and in 

fact undermine, 

congressional intent for the 

applicability of the title V

program. Therefore, under 

the Chevron framework, 

accounting for the “absurd 

results” doctrine, EPA may 

tailor the definition of the 

program to be more 

consistent with 

congressional intent. This 

section explains the 

principles and approach EPA 

is using to accomplish that 

tailoring so

Deleted: be consistent with 

congressional intent and 
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title V to GHG sources; rather, we should examine other 

provisions of the statute and the legislative history to 

determine congressional intent on that question. If 

congressional intent is clear, we must adopt and implement an

applicability approach that is as close as possible to 

congressional intent; and if congressional intent is not clear, 

then we must select an interpretation that is reasonable and 

consistent with the statutory requirements. This section 

explains EPA’s view of congressional intent for the 

applicability of the title V program to GHG sources and the 

principles and approach EPA is using for tailoring. In 

addition, we also respond to other approaches that were 

suggested by commenters.

To determine congressional intent, we consider the 

statutory provisions and legislative history, and our analysis 

is similar to ours for PSD. The most important title V 

provisions and legislative history for this purpose are the 

following: (i) The applicability provisions themselves, which, 

as we have interpreted them, apply title V to all sources that 

emit at least 100 tpy of any air pollutant subject to 

regulation. CAA sections 502(a), 501(2)(B), 302(j). Although 

we do not believe these provisions should be applied literally 

to GHG sources, their broad phrasing indicates, directionally, a 

Deleted: respond to other 

approaches to reconciling 

that were suggested by 

commenters.¶

This final rule reconciles 

the definition of “major 

source” – as narrowed 

through EPA interpretation -

- with congressional intent 

by applying the definition 

to include as many of the 

sources that would be 

included under the terms of 

the definition as promptly 

as possible, consistent with 

the intent 

Deleted: as illuminated by 

Deleted: . This means that 

we intend to phase in title 

V

Deleted: to sources, based on 

their size, over time. The 

specific schedule will 

depend on information we 

have as to the permitting 

authorities’ ability to 

process permits in a timely 

fashion. That information 

will be based on the realworld experience the 

permitting authorities will 

accumulate as they proceed 

to process permit 

application for the larger 

GHG sources, coupled with 

the size of their resources

Deleted: intend to vigorously 

pursue streamlining methods, 

so as to make title V more 

accessible for 
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congressional intent towards inclusiveness of sources in title 

V, including GHG sources. (ii) The provisions for general 

permits, CAA section 504(d); and title V fees, CAA section 

502(b)(3)(A). These provisions give title V an important 

measure of flexibility as to its scope. The explicit 

authorization of general permits means that title V may be 

applied to more sources and more efficiently, thereby saving 

costs to both source and permitting authority. The requirements 

for permit fees provide a mechanism for permitting authorities 

to, over time, develop their programs to cover more sources. In 

this sense, these provisions could be construed to indicate 

congressional intent to apply title V inclusively, to the extent 

that permitting authorities can accommodate additional sources 

through general permits and permit fees. (iii) The detailed 

procedural requirements -- including time periods, such as the 

18-month time period for action on permit applications -- for 

title V permit processing. CAA sections 503, 505. Although 

these requirements are consistent with applying title V to GHG 

sources -- in the sense that at least in theory, there is 

nothing intrinsic to GHG sources that would mean that permitting 

authorities could not comply with these requirements – these 

requirements cast doubt on whether Congress can be said to have 

intended that title V cover the many small GHG sources in light 

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of the risk that including all those sources in title V would 

strain the process. (iv) The provisions and legislative history 

concerning applicable requirements, which indicate that a 

purpose of title V is to include sources’ applicable 

requirements in their permits. CAA sections 503(b)(2), 504(a). 

These provisions, and the accompanying legislative history, 

discussed above, suggest an intent to include within title V GHG 

sources that have applicable requirements, but may also suggest 

that Congress would not have intended to include in title V the 

large numbers of GHG sources that have empty permits. (v) The 

small-business-assistance provisions of section 507 and the 

legislative history of title V – both the permitting program and 

the small-business-assistance program -- concerning the scope of 

the permitting program and small businesses. These indicate 

that Congress intended title V to cover some tens of thousands 

of sources, and did not intend that title V apply to small 

businesses. These provisions and legislative history suggest 

that Congress did not intend to include small GHG sources. 

Finally, the legislative history of title V does not explicitly 

mention GHG sources, which could suggest that Congress did not 

have occasion to focus on whether and how title V would apply to 

GHG sources. 

With all this, we believe that Congress had a clear intent 

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on the question of whether title V applies to GHG sources, and 

that was to apply title V to GHG sources. As with PSD, the most 

important indication of congressional intent in this regard is 

the applicability provisions, which provide, in part, that title 

V applies to “any stationary facility or source of air 

pollutants which directly emits, or has the potential to emit,

[the requisite quantity] of any air pollutant.” CAA §§ 502(a), 

501(2)(B), 302(j). This term is quite broad, and should be read 

to include GHG sources. See Massachusetts v. EPA, 549 U.S. 497, 

533 (2007) (“Because greenhouse gases fit well within the Clean 

Air Act's capacious definition of “air pollutant,” we hold that 

EPA has the statutory authority to regulate the emission of such 

gases from new motor vehicles.”). Moreover, including GHG 

sources – under certain circumstances – is consistent with the 

various statutory provisions and statements in the legislative 

history described previously.

As to the question of how title V applies to GHG sources, 

we believe that here too, Congress can be said to have expressed 

an intent, and that is to apply title V to as many GHG sources 

as possible and as quickly as possible, at least to a certain 

point. As with PSD, we believe that this flows logically from 

the inclusive direction of the applicability provision, the 

flexibility in title V’s scope that is inherent in the 
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provisions authorizing general permits and requiring permit 

fees, the provisions and legislative history indicating that one 

of title V’s purposes is to require sources with applicable 

requirements to gather those requirements into a permit in order 

to promote compliance and enforcement, the detailed process 

requirements, and the legislative history that focuses on 

Congress’s concern about costs to sources and administrability. 

That is, at first, title V may apply to the largest GHG sources 

because they may be expected to have applicable requirements, 

they can be expected to bear the costs of complying, and if 

their inclusion strains the resources of the permitting 

authorities, title V contains tools to address that. In 

addition, including the largest sources under the Tailoring Rule 

will not disrupt the detailed process requirements. Over time, 

more sources may be included in title V, consistent with those 

provisions and legislative history. 

On the other hand, if Congress cannot be said to have 

expressed an intent as to the manner and scope of title V 

applicability to GHG sources, then, under Chevron step 2, EPA 

may apply a reasonable interpretation of the applicability 

provision to determine the scope of coverage of GHG sources that 

is consistent with the statutory requirements. The Tailoring 

Rule qualifies as such an interpretation. The Tailoring Rule in 

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effect reads the applicability provisions not to apply title V 

to GHG sources at or above the 100 tpy level, but instead to 

apply title V to as many of the GHG sources at or above that 

level as possible and as quickly as possible, starting with the 

largest sources first, that is consistent with both the 

permitting authorities’ ability to administer the program and 

with a sensible imposition of costs to sources. However, as 

part of the tailoring approach, we recognize that we may at some 

point determine that it is not appropriate to include in title V 

either the smallest of the GHG sources or sources with empty 

permits. 

As with PSD, we do not believe it is necessary to come to a 

conclusion as to whether, under Chevron step 1, Congress 

intended that title V apply, or not apply, to GHG sources as 

small as the statutory levels, or whether, if Congress expressed 

no clear intent on that question, it is reasonable under Chevron 

step 2 to apply title V to GHG sources at that level, all within 

the context of the tailoring approach. In this rulemaking, we 

promulgate steps that cover larger sources and we provide that 

we will not apply title V to sources below the 50,000/50,000 tpy 

CO2e level for at least the first six years. Because there is 

no need to come to decisions concerning the smaller sources in 

this rulemaking, we intend to consider them further, along with 
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the legal issues concerning congressional intent, in the 

subsequent rulemaking that we commit to doing as part of this 

action.

The specific phase-in schedule will depend on the 

following: We will gather information about the permitting 

authorities’ ability to process permits, and we will develop 

streamlining techniques. Based on that information, we will 

address expanding the title V program in a step-by-step fashion 

to include more sources over time. Each step will be based on 

our assessment of the permitting authorities’ and sources’ 

ability to comply with their respective obligations under the 

title V program. 

 We recognize that the availability of permit fees to 

support title V permit actions creates a potentially important 

source of resources, and that this has implications for the 

permitting authorities’ ability to implement the title V program 

for sources of GHGs. At least in theory, permitting authorities 

could assess and collect sufficient fees to support hiring and 

training sufficient personnel so that they could expand their 

programs to match the expansion in the number of sources covered 

by the program. 

Even so, title V fees cannot be considered a panacea that 

will resolve all resource problems that permitting authorities 

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will have, for several reasons. Permitting authorities will 

likely be constrained as to the rate in which they can increase 

fees in light of the costs to sources. As indicated elsewhere, 

at least at the outset of the program before streamlining 

techniques have been developed, a literal application of the 

title V applicability provisions to GHG sources would, on 

average, cost each industrial source $46,400 and each commercial 

or residential source $23,200 to complete the permit application 

and take other associated actions; and it would cost each 

permitting authority, on average, $19,678 to process the 

industrial source permit and $9,839 to process the commercial or 

residential source permit. Particularly in light of the high 

costs to sources of applying for a permit, it is not likely that 

permitting authorities would be able to pass on to the sources 

in the form of fees the entirety of the permitting authorities’ 

own high costs for processing those permits, at least not right 

away. Even to the extent it would be possible to raise permit 

fees, permitting authorities would have to undergo a process to 

assess, impose, and collect those fees, and then hire and train 

personnel. The survey from the state and local agencies 

described previously forecast a 2-year period for hiring and 

training, without counting time for the fee process. For these 

reasons, we do not believe that the authorization for fees will 

Deleted: ,

Deleted: if 

Deleted: were 

Deleted: and 

Deleted: those fees, then 

collection of 

Deleted: the hiring

Deleted: ing of

Deleted: above

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Deleted: of assessing and 

imposing fees
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allow the permitting authorities either to accelerate Steps 1 or 

2 of the tailoring schedule or to permit a larger number of 

sources at those steps. Step 1 will take effect on January 2, 

2011, step 2 will take effect on July 1, 2011, and the process 

for determining and collecting fees, and then hiring and 

training personnel will take at least several years after July 

1, 2011. 

Moreover, we do not believe that the authorization for fees 

means that permitting authorities can reasonably be expected to 

permit title V sources at levels below 50,000 tpy CO2e before 

2016. The next level below 50,000 tpy CO2e for which we have 

data is 25,000 tpy CO2e, and the costs to permitting authorities 

to run their programs at that level ($126 million) is more than 

double their current costs ($62 million). We do not consider it 

reasonable to expect permitting authorities to more than double 

their program within the first 6 years of title V applicability 

to GHG sources. That it is not reasonable to expect that is 

made even clearer when the permitting authorities’ burdens in 

implementing their PSD programs are considered. The ability of 

permitting authorities to impose fees may have more important 

implications for subsequent steps, and as we address those 

subsequent steps in future rulemakings, we will consider the 

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Deleted: 
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fees. EPA’s approach to fees in this rulemaking is discussed 

elsewhere. 

c. Other Possible Approaches to Reconciling Literal Reading of 

Title V Applicability Provisions and Congressional Intent

Having described how the Chevron framework, accounting for 

the ”absurd results” doctrine, applies to title V requirements 

in this case and why it supports this Tailoring Rule -- under 

which we expect to apply title V to more sources, in a step-bystep fashion, over time -- we turn to the last part of our 

discussion of this doctrine. Here, we address another possible 

approach, which is that that EPA should apply the title V 

program only to sources that are subject to applicable 

requirements, so that sources should not be required to hold 

empty permits (i.e., permits issued to a source that is not 

subject to any applicable requirement for any pollutant). To 

the extent that commenters argue that the statute requires EPA 

to adopt a “no-empty –permits” theory, we disagree. We believe 

that although various provisions of title V indicate that one of 

title V’s purposes is to gather a source’s applicable 

requirements into a single permit, see CAA §§ 503(b)(1), 504(a), 

we do not read those provisions as expressly limiting, as a 

matter of Chevron step 1, title V to sources with applicable 

requirements. The applicability provisions, by their terms, 

Formatted: Font: Not Italic,

Underline

Deleted: possible approaches 

to reconciling literal 

reading of title V 

applicability provisions and 

congressional intent¶

Deleted: tailoring rule

Deleted: es 

Deleted: commenters have 

suggested for reconciling 

the inconsistency between a 

literal reading of the 

applicability provisions and 

congressional intent. ¶

In particular, commenters 

have argued 
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include sources based on amount of emissions, and do not include 

any explicit limits to applicability based on whether the 

sources has applicable requirements. We also note that to date, 

we have issued permits to sources without applicable 

requirements, albeit on rare occasions. We believe that the 

tailoring approach we adopt in this rulemaking best reconciles 

the statutory provisions with congressional intent. Moreover, 

we are concerned that adopting an empty permits approach in 

place of the tailoring approach might not alleviate the very 

large number of small sources overwhelming the permitting 

process. We note, as discussed later in this section, that 

there will be no empty permits in Step 1 and we believe there 

will be extremely few, if any, “empty permits” in Step 2. We 

need to further assess the potential for this approach to 

relieve burden in future steps, taking into account that the 

need for requirements in title V permits will vary based on the 

requirements of each SIP, and noting that some SIPs contain 

broadly applicable requirements. In light of this uncertainty, 

we cannot conclude that this approach would better achieve 

congressional intent. Thus, we disagree that adopting the empty 

permit approach at this time is required or appropriate.

7. Additional Rulemaking for the PSD and Title V Programs

Deleted: rulemaking

Deleted: title

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 The previous sections 5 and 6 discussed our application of 

the Chevron framework, accounting for the “absurd results” 

doctrine, to the PSD and title V applicability requirements, 

respectively. As another point in this regard, which is 

relevant for both PSD and title V purposes, we also commit to 

subsequent rulemakings in which we may further address the 

“absurd results” doctrine. 

Specifically, we will propose or solicit comment on 

establishing a further phase-in, that is, a step 3, that would 

apply PSD and title V to additional sources, effective July 1, 

2013, and on which we commit to take final action, as supported 

by the record, by no later than July 1, 2012. We further commit 

to completing another round of rulemaking addressing smaller 

sources by April 30, 2016. Our action in that rulemaking would 

take into account the severity of the remaining problems 

associated with permitting authority burden and source costs. 

While committing to future action, we do not decide in this 

rule when the phase-in process will ultimately end, or at what 

threshold level, because all that depends on uncertain variables 

such as our progress in developing streamlining approaches and 

on permitting authorities’ progress in developing permitting 

expertise and acquiring more resources. We may continue the 

phase-in process with further rulemaking(s) after 2016. 

Formatted: Indent: First line: 0.5"

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Deleted: ¶

Deleted: 

Deleted: address permitting 

requirements for smaller 

sources, taking

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Alternatively, we may make a final determination through future 

rulemaking that, under the “absurd results” doctrine, PSD and/or 

title V do not apply to GHG sources that, while small and 

relatively inconsequential in terms of GHG contribution, are 

above the statutory tonnage thresholds for these programs, and 

thereby end the phase-in process. In addition, we may consider 

whether to limit title V applicability to GHG sources in order 

to minimize the number of GHG sources with “empty” permits. 

8. Rationale for the Phase-In Schedule for Applying PSD and 

Title V to GHG Sources

 Having discussed in sections V.B.5, V.B.6, and V.B.7 

previously the reasons for tailoring the PSD and title V 

programs, we now describe our rationale for selecting the 

specific phase-in schedule in this rule for applying PSD and 

title V to GHG-emitting sources. To reiterate for convenience, 

under Step 1 of this schedule, which begins on January 2, 2011, 

(i) PSD applies to the GHG emissions of “anyway” PSD sources, 

that is, sources that are subject to PSD anyway due to their 

emissions of conventional pollutants and that undertake a 

modification that results in an increase of at least 75,000 tpy 

CO2e; and (ii) title V applies to “anyway” title V sources, that 

is, sources that are subject to title V anyway due to their 

emissions of conventional pollutants. Under Step 2, which 

Deleted: .

Deleted: phase-in schedule 

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Deleted: sources.¶

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begins on July 1, 2011, (a) sources will be subject to PSD on 

account of their GHG emissions if they newly construct and emit 

at least 100,000 tpy CO2e, or if they are existing sources that 

emit at least 100,000 tpy CO2e of GHGs and make a modification 

that results in the emission of at least 75,000 tpy CO2e; and (b) 

existing and new sources will be subject to title V on account 

of their GHG emissions if they emit 100,000 tpy CO2e in GHG 

emissions. In addition, EPA intends to begin another round of 

rulemaking – Step 3 – in 2011 and commits to complete it by July 

1, 2012. In that rulemaking, we will propose or solicit comment 

on a further phase-in of GHG sources for PSD and title V 

applicability, and we may propose or solicit comment on another 

application of the “absurd results” doctrine that excludes 

categories of sources from PSD or title V. However, under this

rule, in no event will EPA apply PSD or title V to sources below 

the 50,000 tpy CO2e levels in step 3, or any other step we might 

promulgate prior to April 2016. In addition, EPA commits to 

conduct a study, to be concluded by April 30, 2015, evaluating 

the status of PSD and title V applicability to GHG sources, and, 

based on the study, complete a rulemaking by April 30, 2016 that 

addresses another round of a phase-in. 

a. Rationale for Step 1 

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 In Step 1 of our tailoring approach, which begins on 

January 2, 2011, PSD and title V requirements will apply to only 

those sources that are subject to PSD or title V requirements 

anyway due to their conventional pollutants (“anyway” sources) 

and that, in the case of PSD, make modifications that result in 

an increase in GHG emissions of at least 75,000 tpy CO2e. No 

sources would become major for PSD or title V under this step 

based on their GHG emissions alone. This section describes our 

proposal, comments on the proposal and our response to those 

comments, and our rationale for Step 1. 

(1) Proposal 

In our proposal, we proposed (i) the application of PSD and 

title V requirements to sources that emit at least 25,000 tpy 

CO2e, (ii) a PSD significance level of between 10,000 and 25,000 

tpy CO2e, and (iii) a commitment to undertake a study to be 

followed by further rulemaking after 6 years. In addition we 

solicited comment on the alternative of limiting PSD and title V 

applicability to “anyway” sources for at least the first six 

years. Under this approach, PSD and title V applicability would 

be determined based on non-GHG pollutants, and without regard 

to GHGs, but those sources subject to PSD would also be subject 

to BACT requirements for GHGs if their GHG emissions exceeded 

the significance level established in the final rule, and those 

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sources subject to title V would be required to include any 

applicable requirements for GHGs in their permits. 

(2) Comments 

Many commenters supported this “anyway”-source approach, 

and offered a variety of reasons: According to the commenters, 

(i) this approach is a better reading of Congress’s intent in 

the Act and is consistent with Alabama Power v. Costle, 636 F.2d 

323 (D.C. Cir. 1980); (ii) this approach would reduce the 

permitting workload on sources currently considered minor and 

focus PSD and title V requirements on large sources of non-GHG 

pollutants, as intended by Congress; (iii) it is appropriate to 

base PSD and title V applicability on non-GHG emissions until 

data on GHG emissions are available from the GHG Reporting Rule; 

(iv) in the initial phase, this approach would be more 

straightforward to administer, would provide a more predictable 

permitting workload, and would prevent a flood of newly 

regulated sources from overburdening state agencies; (v) this 

approach would provide permitting agencies time to develop 

experience handling GHG sources and requirements under the PSD 

and title V programs; (vi) this approach would provide EPA and 

the permitting agencies the time needed to develop streamlining 

techniques; (vii) this approach is consistent with the “absurd 

results” and “administrative necessity” doctrines because the 

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scope of the permitting programs would remain consistent with 

both Congressional intent and current administrative practice, 

but EPA and state agencies would still be allowed to begin 

regulating GHG emissions from existing PSD and title V sources; 

and (viii) sources already required to obtain PSD permits are 

best equipped to work through BACT issues with permitting 

authorities. 

Commenters added that if BACT is applied for GHG due to 

permit actions involving non-GHG pollutants, EPA would need to 

set a significance threshold for the application of BACT, 

without which BACT could apply to very small (e.g., 1 ton) GHG 

increases associated with projects that otherwise triggered PSD 

for increases of non-GHG. 

(3) Determination as to Step 1, PSD and Title V Applicability

and PSD Significance Level

After considering the administrative burdens from increased 

permitting actions and the need for permitting authorities to 

have sufficient time to develop necessary expertise and staffing 

resources to address that burden, we have decided in this final 

action to establish the “anyway” source approach as Step 1. 

Beginning on January 2, 2011, sources subject to PSD 

requirements for their conventional pollutants anyway will be 

required to apply BACT to their GHG emissions if they construct 

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or modify and in so doing, emit at least 75,000 tpy CO2e in GHGs. 

Similarly, sources subject to title V requirements anyway due to 

their conventional pollutants will be required to meet certain 

requirements for their GHGs, as described elsewhere. These 

requirements at Step 1 for PSD and title V will not expire. On 

July 1, 2011, a further phase-in of PSD and title V 

applicability – Step 2 – will kick in. 

The “anyway” source approach has particular appeal during 

this, the first step of the phase-in approach because it begins 

to apply key PSD and title V program requirements as soon as 

January 2, 2011 to large sources of emissions, but because it 

applies only to sources that are already subject to PSD for 

other pollutants, it can be implemented efficiently and with an 

administrative burden that is manageable in the next 8 months. 

We expect that under this approach, the sources and permitting 

authorities will still face substantial additional work due to 

the GHG emissions. In addition to the activities discussed 

elsewhere, there will be significant and complex policy 

questions about how BACT will be implemented for GHGs that must 

be resolved. These issues will include how to determine BACT 

for GHGs, how to do netting, and other similar issues. Even 

with EPA guidance, many case-specific policy issues will arise 

and will have to be resolved by the permitting authority in the 

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context of a specific permit application. Nevertheless, with 

the “anyway” source approach, this work will be manageable 

because the associated permitting burden will be limited to 

adding a GHG component to each existing permit action for which 

it will be required, and will avoid the significantly greater 

burdens associated with large numbers of new permit actions that 

would be required for sources and modifications that would be 

subject to PSD for the first time. Instead, this “anyway” 

source approach allows permitting authorities sufficient time to 

develop necessary expertise and staffing resources to address 

GHG BACT. 

We agree with commenters that the establishment of a 

significance level – which, in effect, is a BACT threshold -- is 

appropriate, and we have decided to establish this level at 

75,000 tpy CO2e because, for reasons discussed later, that is the 

level that will apply during step 2. At this level, the 

administrative burdens, described later, will be manageable. 

Importantly, we believe a consistent significance level between 

Steps 1 and 2, as opposed to a lower significance level in Step 

1, will provide for a smoother transition and avoid the problems 

that would arise if PSD applied to modifications during Step 1 

that PSD would not apply to in Step 2. Otherwise, we would 

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create a perverse incentive for companies to delay such projects 

until Step 2 to avoid BACT. 

We estimate that Step 1 will result in a 23 percent

increase in permitting authority work hours and a $3 million 

increase – which amounts to a 25 percent increase from the 

current program cost of $12 million -- in their annual costs for 

running PSD programs. This is primarily due to the GHG BACT 

review requirements. For title V programs, we estimate a 2

percent increase in permitting authority work hours and a $1 

million increase in the title V annual program costs for 

permitting authorities under Step 1 as compared to the current 

program cost of $62 million. These work hours and costs will be 

needed primarily to review GHG emissions information, add any 

GHG-related requirements to title V revisions and renewal 

actions that would otherwise be occurring, respond to comments 

and petitions from the public, as well as develop fee 

requirements and make fee determinations associated with issuing 

new or revised title V permits that add GHG-related information. 

For both the PSD and title V programs on a combined basis, the 

additional costs for Step 1 will be $4 million, which amounts to 

a 5 percent increase in the current combined program cost of $74 

million. 

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In addition to these workload and monetary costs, 

permitting authorities will confront additional burdens before 

and during Step 1, which we have not attempted to quantify. One 

of the most significant of these is training staff in the PSDrelated areas of GHG emissions calculations and BACT 

evaluations. In addition, permitting staff will need to build 

staff expertise and capacity for addressing GHG requirements in 

preparation for Step 2, which will begin only 6 months after 

Step 1; and in communicating and providing outreach to sources 

addressing GHG emissions for the first time. Based on comments 

we received on the proposal from permitting authorities, we 

believe these additional training and outreach requirements – 

for both the PSD and title V programs -- will add significantly 

to the permitting authorities’ burden during the initial 6-month 

period under Step 1. 

 We believe that these administrative burdens are 

substantial but manageable. Following this action, permitting 

authorities will have only 8 months to prepare for Step 1, when 

they will need to increase their resources by 5 percent for both 

the PSD and title V programs combined, and be able to implement 

BACT requirements for GHG sources. During Step 1, they will 

need to prepare for Step 2, when, as discussed later, they will 

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need to process over 900 additional PSD permits each year and 

begin to process over 2,600 additional title V permit actions. 

We have decided to limit Step 1 to the “anyway” source 

approach, and not apply PSD or title V to sources based on their 

GHG emissions, for several reasons. First, we believe that the 

administrative burdens described previously are the most that 

the permitting authorities can reasonably be expected to manage 

before and during Step 1. Tighter PSD and title V applicability 

requirements would mean greater administrative burdens. 

Second, we believe that the costs of GHG permitting to the 

sources, as described previously, are substantial and as a 

result, necessitate that we wait for the permitting authorities 

to develop the PSD and title V programs for GHG sources during 

the first 6 months of 2011 before subjecting sources to PSD and 

title V requirements on account of their GHG emissions. By July 

1, 2011, when Step 2 takes effect, the PSD and title V programs 

will be better developed. For example, the permitting 

authorities will have more experience making BACT 

determinations. In addition, by that time, sources will have 

had more time to prepare for the permitting processes. In 

addition, as suggested by one commenter, the additional time 

will allow sources and permitting authorities to address the 

current uncertainty surrounding how to measure high-GWP gases. 

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Third, we estimate that “anyway” sources account for 

approximately 65 percent of total national stationary source GHG 

emissions. As a result, limiting Step 1 to these sources will 

still capture a large portion of the GHG inventory. 

A large number of commenters urged us to leave this 

“anyway” source approach in place until such time as we complete 

an assessment and conduct further rulemaking, which we proposed 

would be 6 years from now. We are not taking this action; 

rather, for the reasons discussed next, we believe it is 

reasonable to use GHG thresholds to begin to phase in PSD and 

title V applicability to additional sources in Step 2. 

b. Rationale for Step 2 

(1) Proposal 

We proposed to establish the applicability level for PSD 

and title V to GHG sources at 25,000 tpy CO2e, and we proposed a 

PSD significance level in the range of 10,000 to 25,000 tpy CO2e. 

Our burden estimates at proposal led us to conclude that at 

those threshold levels, for the PSD program, “approximately 400 

additional new or modified facilities would be subject to PSD 

review in a given year. These include approximately 130 new 

facilities and approximately 270 modifications....” 74 FR 55,331, 

col. 1. We estimated that processing these numbers of 

additional permits, along with doing the additional work 

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associated with GHG emissions from sources subject to PSD anyway 

due to their conventional emissions, would increase permitting 

authority burdens by “approximately 112,000 staff hours at an 

additional cost of approximately $8 million. This workload 

amount represents an increase of about 1.3 times, or 32 percent, 

in the current burden for permitting authorities on a nationwide 

basis.” Id. col. 3. We concluded that “this additional burden 

is manageable,” but that “any threshold lower than 25,000 tpy 

CO2e, would create undue administrative burdens.” Id. 

 For the title V program, we estimated that at a 25,000-tpy 

CO2e permitting threshold, “about 13,600 existing facilities” 

would become subject to title V, and that to manage the 

additional workload associated with permitting those sources and 

with the other permit revisions and modifications that would 

result from the 25,000 tpy CO2e threshold, permitting authorities 

would require an additional 492 FTEs, which would be an 

estimated 50 percent increase over current title V staffing 

levels. 74 FR 55,335, cols. 1-2. 

(2) Comments 

We received a significant number of comments from both 

permitting authorities and industry representatives that our 

proposed GHG threshold of 25,000 tpy CO2e for major source 

applicability was too low and would result in an unmanageable 

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amount of permitting actions in the near term. Many offered 

evidence that we severely underestimated both the number of 

permitting actions and the per-permit administrative burden, for 

both PSD and title V programs. 

 Commenters also asserted that the proposed 25,000 tpy 

threshold is too low because it will subject small sources 

(including many small businesses) to PSD and title V, which is 

not in keeping with Congress’s intent to limit PSD and title V 

to large sources when Congress set the 100/250 tpy thresholds 

for the permitting programs. EPA, in collaboration with the 

Small Business Administration (SBA), conducted an outreach 

meeting designed to exchange information with small entities 

that may be interested in these regulations. The EPA took this 

small business outreach effort into account when finalizing this 

rule. Many commenters from this outreach effort said that there 

were many more small businesses that would become to PSD and 

title V due to the proposed permitting thresholds than EPA 

estimated at proposal. 

Many commenters recommended specific major source 

thresholds for PSD and title V, including levels of 25,000 (as 

proposed), 40,000, 50,000, 100,000, 150,000, 250,000, and 

1,000,000 tpy CO2e. A majority of the commenters –_ including 

both industry and state agency commenters -- recommended major 

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source thresholds of 100,000 tpy CO2e. However, several state 

agency commenters recommended thresholds of 50,000 tpy CO2e. 

Other commenters recommended sector-specific thresholds. For 

example, solid waste industry commenters suggested thresholds of 

820,000 tpy CO2e for PSD [which they calculate to be equivalent 

to the existing PSD threshold for “municipal solid waste 

landfill emissions,” i.e., 250 tpy non-methane organic emissions

(NMOC)] and 320,000 tpy CO2e for title V (calculated to be 

equivalent to the existing major source applicability threshold 

of 100 tpy NMOC). Other commenters urged EPA to set the GHG 

thresholds at levels that correspond to emissions of 

conventional pollutants at the 100/250 tpy level. 

Many of the commenters that recommended increasing the 

thresholds cited EPA’s estimates that a particular threshold 

would significantly reduce the number of sources subject to the 

rule while causing only a slight reduction in the percentage of 

GHGs captured. Several of these commenters noted that Table 

VIII-2 in the proposal preamble indicates that shifting the 

major source threshold for PSD from 25,000 to 100,000 tpy CO2e 

would reduce the number of major sources from 13,661 to 4,850 

while reducing the coverage of U.S. stationary source GHG 

emissions by only about 4 percent. Other commenters referred to 

the RIA for the GHG Reporting Rule to conclude that raising the 

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threshold from 25,000 to 100,000 tpy CO2e would exclude thousands 

of entities that, on a combined basis, emit only one percent of 

the nation’s GHG emissions. See the Response to Comments 

document for this final rulemaking for more detailed description 

of comments received on our proposed burden assessment. 

 Many commenters also recommended specific PSD GHG 

significance thresholds, including levels of 10,000 (as 

proposed), 15,000 (within the proposed range), 25,000 (also as 

proposed), 40,000, 50,000, and 100,000, and 150,000 tpy CO2e, as 

well as suggesting sector-specific thresholds. These 

recommendations were based on the view that we had 

underestimated the number of modifications and that the burden 

of permitting at the proposed levels would therefore be much 

worse than we projected. A number of the commenters argued that 

the significance threshold should be no less than the major 

source threshold, at whatever level that is set. The largest 

number of commenters recommended a PSD significance threshold of 

100,000 tpy CO2e, although significant numbers also support 

25,000 and 50,000 tpy CO2e. 

(3) Rationale for step 2 

 Based on these comments, we reassessed our original burden 

estimates from our proposal. This reassessment is discussed at 

the beginning of this section. We decided that, once this 

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adjustment is taken into account, the burdens at the proposed 

25,000 threshold and the proposed 10,000-25,000 significance 

levels would be unmanageable. We therefore evaluated higher 

thresholds ranging from a 25,000 tpy CO2e major source 

applicability level for PSD and title V to a 50,000, 75,000, or 

100,000 tpy CO2e level, with associated PSD GHG significance 

levels of equal or lesser magnitude; and we selected the 

100,000/75,000 tpy CO2e level. Central to our decision to 

promulgate higher thresholds than what we proposed is our 

recognition, based on comments and further analysis, that 

applying PSD to GHG sources at the statutory or any other 

threshold level or significance level that we have considered 

would result in (i) a greater number of sources, and 

significantly greater number of modifications than we first 

estimated becoming subject to those programs; and (ii) a greater 

per-permit cost than we first estimated to the permitting 

authority of processing those permit actions. We discussed our 

revised estimates and reasoning at the beginning of this 

section. 

We now estimate that the 25,000/25,000 tpy level would 

result in 250 additional PSD permit actions for new construction 

(either for GHG-only sources or additions to otherwise occurring 

permits) and an additional 9,200 PSD permits for modifications 

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each year (compared to our estimate at proposal of 130 for new 

construction and 270 for modifications). This level of 

permitting would require an additional 2,815,927 work hours, or 

1,400 FTEs (compared to our estimate at proposal of 112,000 

[additional?] work hours, or 57 FTEs); and would cost an 

additional $217 million each year (compared to our estimate at 

proposal of an additional $8 million). See 74 FR 55,331 

(proposal). This $217 million amount represents approximately a 

1,800 percent increase over current permitting authority annual 

cost of $12 million for the major NSR programs 

 For title V, under our final burden analysis at a 25,000 

tpy CO2e threshold, we estimate a $64 million annual increase in 

program costs to permitting authorities to add GHG emission 

sources, which reflects a greater than 100 percent increase over 

current programs costs of $62 million. We estimate that this 

increased burden would result in the need for almost 700 new 

FTEs nationwide at permitting authorities (compared to our 

estimate at proposal of 492 additional FTEs, or about a 50% 

increase in existing program size). This increase in burden is 

due to an estimated annual increase of 2,500 new title V 

permits, over 9,500 permit revisions, and over 2,500 permit 

renewal actions due to GHG emission sources. These additional 

title V actions compare to current annual program actions of 

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approximately 50 new title V permits, 1,394 significant 

revisions, and 3,267 permit renewals. 

 Based on this information, we have decided not to finalize 

our proposal to apply a 25,000 tpy CO2e applicability threshold 

to GHG sources at the time that PSD and title V take effect. At 

that level, too many sources – many more than we thought at 

proposal – would be subject to high permitting costs. In 

addition, permitting at that level and at that time would not be 

administratively feasible. The resulting increase in the number 

of PSD and title V permitting actions and workload would create 

insurmountable resource demands for permitting agencies in the 

near term, which would jeopardize the functioning of these 

permitting programs. We are mindful that not only would the 

permitting programs have to bear the costs that our estimates 

are able to monetize, but they would also incur burdens 

associated with hiring and training staff to make and implement 

GHG BACT determinations, GHG emissions evaluations, and other 

evaluations required under the PSD program for a wide variety of 

formerly unpermitted sources, including significant numbers and 

types of small manufacturing and commercial or residential 

establishments. They would also incur burdens associated with 

reviewing applications, citizen comment and petitions, and the 

need to communicate and provide outreach to new categories of 
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sources, including, again, significant numbers and types of 

small manufacturing and commercial or residential sources. 

Thus, the increased administrative burdens at the 25,000/25,000 

tpy CO2e levels are so great that we have concluded that they 

would not be consistent with the goals of avoiding absurd 

results that contravene Congressional intent, including avoiding 

a permitting burden that would overwhelm the capacity of 

permitting authorities to effectively implement their programs. 

Based on our revised burden analysis, in this final action, 

we have decided to establish a multi-step, phase-in approach 

that contains a significantly higher initial threshold level: 

We have determined that a 100,000 tpy CO2e major source threshold 

level for PSD and title V purposes, and a 75,000 tpy CO2 

significance level, produce a level of permitting activity that 

would certainly be an increase over current workload, but that 

would be administratively feasible by July 1, 2011. As a 

result, we have decided to finalize these thresholds as Step 2. 

In reaching this conclusion, we needed to consider the 

permitting authorities’ capacity to address newly-major sources 

as expeditiously as possible. Note that our Step 1 approach 

does not cover newly-major sources. As a result, step 2 

threshold and timing has to be established in a way that takes 

into account permitting authority challenges in addressing many 

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sources and categories that would be subject to major source 

permitting for the first time. 

 We considered the various PSD and title V threshold 

applicability and significance level options in our final burden 

analysis, summarized in Table V-1, including levels at 50,000 

CO2e, and 100,000 CO2e. As Table V-1 indicates, we estimate that 

a 100,000 tpy CO2e major source applicability threshold would 

result in approximately 550 sources becoming newly classified as 

major sources for PSD based on their GHG emissions, while a 

50,000 tpy CO2e threshold would result in 3,500 newly classified 

major sources. 

 We then considered the impact on both PSD and title V 

programs of different PSD significance level options for GHGs. 

The choice of a PSD significance level has a direct impact on 

title V burdens because PSD permit requirements resulting from 

modification activities will result in required title V permit 

revisions. We developed PSD and title V burden estimates based 

on significance levels of 50,000 tpy, 75,000 tpy and 100,000 tpy 

CO2e, combined with a major source applicability level of 100,000 

tpy CO2e. 

At a 50,000 tpy CO2e significance level, we estimated an 

annual increase of approximately 1,800 PSD permitting actions 

and almost 2,000 additional title V permitting actions, as 

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compared to Step 1. At a 75,000 tpy CO2e significance level, we 

estimated an annual increase of approximately 900 PSD permitting 

actions and just over 1,000 additional title V permitting 

actions as compared to Step 1. At a 100,000 tpy CO2e 

significance level we estimated an annual increase of 

approximately 25 PSD permitting actions and 210 additional title 

V permitting actions as compared to Step 1. For title V, under 

these different scenarios, the major source applicability level 

of 100,000 tpy CO2e results in approximately 200 new permits 

annually, but, as noted, the choice of significance levels 

affects the number of required permit revisions. 

 Based on this information, we have decided to set our final 

Step 2 thresholds at 100,000 tpy CO2e for major source 

applicability under PSD and title V and at a 75,000 tpy CO2

significance level for PSD. Overall, we estimate that the 

almost 900 additional PSD permitting actions (virtually all of 

which would be modifications) per year at these levels will 

result in an approximately a $21 million increase (from Step 1) 

in states’ annual costs for running PSD programs. In addition, 

we estimate that the 1,000 additional title V permit actions 

will cause the total title V burden for permitting authorities 

to increase by $6 million annually from Step 1. This total 

increase in permit program burdens of $27 million represents a 

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34 percent increase over the $78 million in total cost of PSD 

and title V programs at Step 1. We consider this a substantial 

increase particularly because Step 2’s start date of July 1, 

2011 is only 6 months after Step 1’s start date of January 2, 

2011. What’s more, Step 1 will entail a substantial increase in 

permitting authority obligations, so that adding the costs of 

Step 1 and Step 2 together -- $31 million – means that 

permitting authorities will be required to increase their 

permitting resources by approximately 42 percent between now and 

Step 2. In addition to the administrative burdens we have been 

able to monetize, we must be mindful that permitting authorities 

will incur other burdens, including the significant support and 

outreach activities by permitting staff for the many newly 

permitted sources. We believe that any lower thresholds in this 

timeframe, whether in the PSD and title V applicability levels 

or in the significance level, would give rise to administrative 

burdens that are not manageable by the permitting authorities. 

Although the burdens at the 100,000 tpy CO2e/75,000 tpy CO2e 

levels are steep, we consider them manageable. Step 2 

permitting for GHGs will mostly involve source categories in 

which some sources have traditionally been subject to 

permitting, which should render applying even the new GHG 

requirements more manageable. These source categories include 

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fossil fuel-fired power plants, petroleum refineries, cement 

plants, iron and steel plants, and petroleum refineries, in 

addition to other large industrial type source categories. A 

full description of the type of sources that we expect will have 

GHG emissions that exceed the 100,000 tpy CO2 threshold is 

provided in the “Technical Support Document for Greenhouse Gas 

Emissions Thresholds Evaluation” located in the public docket 

for this rulemaking. In addition, because Step 2 does not begin 

until July 1, 2011, permitting authorities have about 14 months 

to prepare for it. 

 In addition, we believe that the sources that will become 

subject to PSD and title V requirements at the 100,000/75,000 

tpy CO2 levels will be able to accommodate the additional costs 

of permitting. For the most part, these sources will be of a 

comparable size and activity level as those sources that are 

already subject to those requirements. 

 Because the administrative burdens at the 100,000/75,000 

level are as heavy as the permitting authorities can reasonably 

be expected to carry, adopting these threshold levels is 

consistent with our legal basis under the “absurd results” 

doctrine. Under this basis, we are reconciling the statutory 

levels with congressional intent by requiring that the PSD and 

title V requirements be applied to GHG sources at levels as 

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close as possible to the statutory thresholds, and as quickly as 

possible, in light of costs to sources and administrative 

burdens. 

 Because the administrative burdens at the 100,000/75,000 

level are manageable, we do not believe that higher threshold 

levels are justifiable for Step 2. Specifically, at the 

100,000/100,000 level – which would entail a 100,000 tpy CO2e 

significance level, rather than a 75,000 tpy CO2e level – 

permitting sources would need to handle only 20 additional 

modifications beyond current levels, and thus would not incur 

substantial additional costs. By the same token, we disagree 

with commenters who suggested that we needed to set permanent 

GHG permitting thresholds for major sources at a rate equivalent 

to the amount of GHG that would be emitted by conventional 

pollutants at the 100 and 250 tpy level in order to meet the 

legal bases of the “absurd results” and “administrative 

necessity” doctrines. These levels would likely be well above 

300,000 tpy CO2e, depending on fuel types and assumptions 

regarding the relative emissions of GHGs compared to the 

conventional pollutants. Our data show that none of the levels 

above 100,000/75,000 would result in significant increases in 

administrative burdens. As a result, establishing these levels 

would not apply PSD or title V requirements to GHG sources as 
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quickly as possible, and thus would not be consistent with our 

approach in the Tailoring Rule. 

We estimate that facilities meeting the Step 2 major source 

applicability thresholds account for approximately 67 percent of 

total national stationary source GHG emissions. Many commenters 

felt that this should be an important basis for our selection of 

a threshold, stating that there is no significant loss in GHG 

emissions coverage of source categories at the 100,000 tpy CO2

threshold, and in some cases arguing that as a result, we should 

set the level even higher. We agree that it is important that 

the coverage in step 2 represents 86 percent of the coverage at 

full implementation of the statutory 100/250 thresholds. 

c. Rationale for EPA’s Plan Beyond Step 2 

 EPA commits that after Step 2, EPA will begin another 

rulemaking in 2011 and complete it by July 1, 2012, and in that 

rulemaking take comment on a further phase-in of GHG sources for 

PSD and title V applicability (Step 3). However, under this

rule, in no event will EPA apply PSD or title V to sources below 

the 50,000 tpy CO2e levels prior to 2016. In addition, EPA 

commits to conduct a study, to be concluded by April 30, 2015, 

evaluating the status of PSD and title V applicability to GHG 

sources, and, based on the study, complete a rulemaking by April 

30, 2016 that addresses another round of a phase-in. 

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(1) Proposal 

In our proposal, we noted that following implementation of 

the first phase of PSD and title V applicability to GHG sources, 

generally at the 25,000 tpy CO2e threshold, additional action 

would be required over time to assure full compliance with the 

statute. We did not establish more steps in the schedule, but 

we did commit to conduct a study, to be completed by 5 years 

after promulgation, evaluating the status of PSD and title V 

applicability to GHG sources, and, based on the study, complete 

a rulemaking by 6 years after promulgation that addressed an 

additional step of the phase-in. 

(2) Comments 

 A number of commenters supported the proposal’s overall 

approach to phase in the permitting of GHGs, mainly because this 

approach will allow permitting of the largest sources of GHGs 

immediately while collecting more information about smaller 

sources and more fully considering streamlining options for 

subsequent phases. Many of these commenters made clear that 

they do not support implementation of the statutory 100/250 tpy 

thresholds, even through a phase-in approach. On the other 

hand, one commenter asserted that EPA has failed to demonstrate 

that it needs 6 years to study and implement NSR and title V for 

sources emitting less than 25,000 tpy. The commenter contends 

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that EPA has not analyzed, among other things, what combined 

effect the full implementation of its streamlining proposals in 

the 15 months before the due-date for title V permit 

applications would be to reduce the cost, complexity, and number 

of title V permit applications that would have to be submitted. 

(3) Rationale for Further Steps

We agree with commenters who support a phased-in approach 

to the GHG Tailoring Rule. Our final action reflects a multistep process that we believe will facilitate a manageable 

expansion of PSD and title V applicability, as appropriate, to 

GHG-emitting sources. In our final action, we have established 

the initial two steps of a multi-step phase-in of lower 

threshold applicability with a commitment to take further 

regulatory activity to consider adopting lower thresholds. We 

believe this process will provide substantial opportunity for 

permitting authorities and sources to establish enough 

experience and information, and to provide significant realworld feedback to EPA, so as to better inform decisions on 

future phase-in steps. 

With this overall phase-in approach in mind, in this final 

rule, EPA includes an enforceable commitment to undertake a 

notice-and-comment rulemaking that would begin with a 

supplemental notice of proposed rulemaking that we expect to be 

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issued in 2011 and that we commit will be finalized in 2012. 

The notice will propose or solicit comment on further reductions 

in the applicability levels. This rulemaking will take effect 

by July 1, 2013 and therefore, in effect, constitute Step 3. In 

this action, we are committing to a rulemaking for Step 3, but 

are not promulgating Step 3, because it is important to allow 

EPA and the permitting authorities to gain experience permitting 

sources under Steps 1 and 2, and to allow time to develop 

streamlining methods, before attempting to determine what would 

be the next phase-in levels for PSD and title V applicability. 

While committing to future action, we do not decide in this rule 

when the phase-in process will ultimately end, or at what 

threshold level, because all that depends on uncertain variables 

such as our progress in developing streamlining approaches and 

on permitting authorities’ progress in developing permitting 

expertise and acquiring more resources. We may continue the 

phase-in process with further rulemaking(s) after 2016. 

Alternatively, we may make a final determination through future 

rulemaking that, under a Chevron analysis, accounting for the 

“absurd results” doctrine, PSD and/or title V do not apply to 

GHG sources that, while small and relatively inconsequential in 

terms of GHG contribution, are above the statutory tonnage 

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thresholds for these programs, and thereby end the phase-in 

process. 

In addition, in this action, we are determining that in no 

event – whether through Step 3 or a subsequent step – will we 

apply PSD or title V to sources at the 50,000/50,000 level or 

lower prior to May 1, 2016. We have several reasons for making 

this determination at this time. Most importantly, our 

examination of the expected burdens to the permitting 

authorities of applying PSD and title V to GHG sources convinces 

us that extending the permitting programs to sources at or below 

the 50,000/50,000 level within 6 years of promulgation would 

result in prohibitively heavy burdens. This threshold option 

would result in close to 2,000 additional annual PSD permitting 

actions per year over the current program and more than 1,000 

over Step 2, including both new construction and modifications. 

For title V, we estimated an increase of over 1,000 new title V 

permits (all newly permitted sources because of GHG emissions) 

over 2,000 permit revisions per year over the current program, 

and about 980 new title V permits and 900 permit revisions more 

than the Step 2 amounts. 

These increases, which could occur between 2013 and 2016 

under our approach depending on the outcome of the step 3 

rulemaking, represent very substantial additions to the 

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permitting program. In terms of cost, we estimate that these 

additional actions would result in a $73 million per year 

increase in joint PSD and title V program costs over the current 

programs – which is almost a doubling of costs – and $42 million 

annual cost increase over Step 2 for the current programs. We 

believe that it would take permitting authorities some time to 

adjust to this workload. This is particularly true because at 

the 50,000/50,000 tpy CO2e level, smaller sources – including 

ones not previously subject to permitting requirements – will 

become subject to PSD and title V. It will take some time for 

both the permitting authorities and the sources to absorb these 

new obligations. 

Importantly, the next lower cut-off – below 50,000 for the 

major threshold level – is the 25,000/25,000 level. For the 

reasons discussed previously, this level is clearly not 

manageable within the first 6 years after this action. This 

applicability level would bring in over 7,000 sources that would 

be newly subject to title V permitting and result in close to 

10,000 new PSD permitting actions. This would result in a 380

percent increase over current program costs for PSD and title V 

to run these programs. Based on comments we received from state 

and local permitting agencies on our proposed Tailoring Rule, 

these levels of permitting activities would far exceed the 

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administrative capabilities of the permitting agencies for at 

least the near future. Thus, the 6-year exclusion is necessary 

to provide these agencies and their permittees certainty that 

this will not occur. 

We recognize that at present, we do not have data that 

would allow us to compile administrative burden estimates for 

specific levels between the 50,000/50,000 and 25,000/25,000 tpy 

CO2e levels we assessed. However, it is clear that the burdens 

begin to rise sharply below the 50,000/50,000 level. To 

reiterate, the combined PSD and title V administrative burdens 

at the 50,000/50,000 tpy CO2e level cost almost twice as much as 

the current programs, but the burdens at the 25,000/25,000 level 

cost almost four times as much as the current programs. As a 

result, we conclude that dropping the level below 50,000/50,000 

too soon would quickly expose the permitting authorities to 

unacceptably high burdens. 

As a further reason for concluding that we will not reduce 

thresholds beyond 50,000/50,000 tpy CO2e during the first 6

years, we recognize that the PSD permitting process in 

particular carries important ramifications for the permitting 

authorities and the affected sources. If we have underestimated 

the permitting burden or the ability of states to respond to 

their additional workload, then permitting backlogs will result, 

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and PSD permit issuance will be delayed, and sources seeking a 

PSD permit will not be able to construct or modify. If this 

were to happen on a large enough scale, it could have 

potentially serious consequences for the national economy. 

Moreover, we need to be mindful that the best information 

we currently have as to permitting authority burdens represents 

a national average, as described previously. Our information at 

the individual state and local level, where permitting occurs, 

is not as robust. Accordingly, we recognize that a particular 

state may encounter permitting costs that are higher than 

average, and this may result in permitting backlogs in that 

state, with the consequence that sources in that state will face 

long delays in constructing or modifying. Similarly, even if a 

particular state’s costs are in line with the national average, 

that state may not be able to find the additional resources to 

cover those costs as readily as other states. For this reason, 

too, sources in that state could face long delays in 

constructing or modifying. 

Beyond the administrative burdens to permitting 

authorities, we recognize that the costs of PSD and title V 

permitting to sources may be high, and we are not inclined to 

impose them at this time on sources smaller than the 

50,000/50,000 tpy CO2e threshold. At that level, the permitting 

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programs will apply to a significant number of newly permitted 

sources, including a variety of small manufacturing, commercial 

and residential categories. The next level that we have 

analyzed is the 25,000/25,00 tpy CO2e threshold. At that level, 

more than 7,000 more sources would become subject to PSD each 

year – almost all due to modifications – and another 4,000 

sources would become subject to title V each year. These 

sources would be even smaller than those that already will have 

become subject to PSD and title V due to their GHG emissions. 

We do not think it reasonable to subject more of those types of 

sources, and smaller ones, to permitting costs within the next 6

years. 

Finally, we note that moving from a 50,000 tpy CO2e 

threshold to 25,000 tpy CO2e will increase the emissions coverage 

of GHG stationary sources from 70 percent to 75 percent

nationwide, which we consider to be a relatively small amount. 

 We recognize that our progress in developing streamlining 

methods will be a key determinant to the ability of permitting 

authorities to administer, and sources to comply with, PSD and 

title V at GHG emission levels below 50,000/50,000. Although we 

commit to pursue streamlining, we cannot predict our progress. 

This uncertainty may be problematic for stakeholders, primarily 

permitting authorities and industry. That is, permitting 

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authorities will face uncertainty in planning the scope of their 

programs over the next few years, and industry will face 

uncertainty as to what new construction projects and 

modifications will be subject to PSD for GHGs. By determining 

now that for the next 6 years we will not impose PSD 

requirements below a floor at the 50,000/50,000 level, we add a 

measure of needed certainty. 

We also recognize that selecting a level that is too low or 

keeping a level for too long means that some sources may 

construct or modify without implementing BACT level controls, 

and this could result in additional emissions of GHGs. We need 

to be vigilant and to protect against this outcome. Even so, 

all things considered, we believe that our determination not to 

apply the PSD or title V permitting requirements to sources 

below the 50,000/50,000 tpy CO2e level for the first 6 years also 

represents a reasonable balancing of protection of the 

environment with promotion of economic development. This type 

of balancing is consistent with our authority under the PSD 

provisions. 

We also raised the issue of “hollow” or “empty” permits in 

discussing our rationale for why it may make sense to delay 

title V permitting under our proposal. We were concerned that 

many title V permits for GHG sources would contain no applicable 

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requirements, and their issuance would therefore be of little 

value and would not be the best use of scarce resources. 

Several commenters agreed that implementing title V for GHG 

will, at least initially, require empty permits to be issued to 

GHG sources because such sources will not be subject to 

“substantive” requirements, and that this would not be the best 

use of scarce resources. 

 We believe that the amount of resources that would be spent 

and the limited value that would from, empty permits does 

warrant consideration under the Chevron analysis, take account 

of the “absurd results” doctrine. Therefore, we may consider 

the role of empty permits when we undertake future rulemaking. 

However we believe the issue of empty permits has limited 

relevance to the first two steps of the phase in that we are 

promulgating in this rule. During step 1, permitting for GHGs 

is only required if the source is otherwise subject to 

permitting for its emissions of non-GHGs, meaning that those 

sources will be subject to existing substantive applicable 

requirements for non-GHGs (e.g., NSPS, MACT, and SIP 

requirements, including PSD). Thus, there should be few, if 

any, empty permits, at least with respect to applicable 

requirements for non-GHGs, during step 1. For step 2, it is 

possible that sources that become subject to title V 

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requirements for GHG emissions may not be subject to other 

requirements, but our assessment suggests that this will be 

rare. We estimate that virtually all of the 550 newly-major 

sources in step 2 will be subject to applicable requirements 

under the CAA because they are from categories that have been 

traditionally subject to regulations, such as smaller industrial 

sources from already regulated categories, large landfills, and 

oil/gas/coal production. Even the approximately 50 newlysubject commercial sources in step 2, which we estimate to be 

comprised of very large hospitals, are likely to be covered by 

standards for medical waste incinerators. Thus, we project few, 

if any, empty permits during step 2. 

In later stages of implementation (e.g., prospective step 

3) or in the event that we permit smaller, non-traditional 

sources of GHGs that have never otherwise been subject to major 

source permitting, there would be a greater potential for empty 

permits to be issued under title V. Cognizant of this, we 

intend to further explore in the rulemaking for step 3 empty 

permit theories under the “absurd results” rationale that may 

serve to permanently narrow the scope of title V to exclude 

sources that would potentially be required to obtain an empty 

permit due to GHG emissions. 

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In this action, EPA is also finalizing its proposal to 

commit to conduct an assessment of the threshold levels – to be 

completed in 2015, 5 years after this action -- that will 

examine the permitting authorities’ progress in implementing the 

PSD and title V programs for GHG sources as well as EPA’s and 

the permitting authorities’ progress in developing streamlining 

methods. We further commit to undertake another round of 

rulemaking -- beginning after the assessment is done, and to be 

completed by April 30, 2016 – to address smaller sources. 

We disagree with the commenter who asserted that we do not 

need 6 years to study and implement PSD and title V for smaller 

sources. As we discussed in the proposal, and reiterate in this 

final action, we do not have sufficient information at this time 

to determine the applicability and effectiveness of the various 

permitting streamlining techniques. For reasons discussed in 

more detail in section V.E.1 regarding streamlining, we are not 

now able to determine how such techniques will be implemented or 

whether they will prove viable or effective. We agree with the 

commenter that these measures may reduce the scope, cost, and 

complexity of these programs, but there is considerable 

uncertainty as to the extent of this effect. We do commit in 

this action to fully investigate, propose, and evaluate these 

permit streamlining techniques to determine where they may have 

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applications, how they would be applied, and whether they can 

withstand legal challenge. Even for those techniques that may 

ultimately be deemed viable there is a significant time period 

necessary for rulemaking and state adoption, all of which could 

take up to 3 years or more. We also note that we will be 

required to complete our study of the effectiveness of these 

techniques within 5 years, meaning that, in order to complete it 

in time, we will essentially need to begin the study as soon as 

relevant data are starting to become available. Finally, the 

sixth year, in which EPA must complete rulemaking, requires 

proposal and promulgation of a rule within 1 year, which is an 

ambitious schedule. Therefore we believe that 6 years is an 

ambitious schedule, and appropriate for this type of effort. We 

also have received a substantial number of comments from 

permitting authorities that agreed with our 5-year timeframe, or 

a greater timeframe, to get more prepared for permitting smaller 

sources. 

d. Other Comments on “Absurd Results” Doctrine

 We received other comments on our application of the 

“absurd results” doctrine, which we respond to in the Response 

to Comments document. One comment was overarching, and so we 

respond to it here: Some commenters argued that the “absurd 

results” doctrine could not be applied because EPA had other 

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approaches for resolving the problems raised by applying PSD to 

GHG sources. In particular, the commenters insisted that we 

were not obligated to issue the light-duty vehicle rule, and had 

we not done so, we would not have triggered PSD; or at the 

least, we could have delayed issuing the light-duty vehicle rule 

for some period of time, during which we could develop 

streamlining measures and permitting authorities could ramp up 

resources and thereby minimize the need for tailoring when we 

did promulgate the light-duty vehicle rule. 

 These commenters also commented during the light-duty 

vehicle rulemaking that we were not obligated to conduct that 

rulemaking, or to conduct it at the time that we did. We 

believe that our response there suffices for here, as well: 

 Some of the comments relating to the stationary 

source permitting issues suggested that EPA should 

defer setting GHG standards for new motor vehicles to 

avoid ... [adverse] stationary source permitting 

impacts. EPA is issuing these final GHG standards for 

light-duty vehicles as part of its efforts to 

expeditiously respond to the Supreme Court’s nearly 

three year old ruling in Massachusetts v. EPA, 549 

U.S. 497 (2007). In that case, the Court held that 

greenhouse gases fit within the definition of air 

pollutant in the Clean Air Act, and that EPA is 

therefore compelled to respond to the rulemaking 

petition under section 202(a) by determining whether 

or not emissions from new motor vehicles cause or 

contribute to air pollution which may reasonably be 

anticipated to endanger public health or welfare, or 

whether the science is too uncertain to make a 

reasoned decision. 

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 The Court further ruled that, in making these 

decisions, the EPA Administrator is required to follow 

the language of section 202(a) of the CAA. The Court 

stated that under section 202(a), "[i]f EPA makes [the 

endangerment and cause or contribute findings], the 

Clean Air Act requires the agency to regulate 

emissions of the deleterious pollutant." 549 U.S. at 

534. As discussed above, EPA has made the two 

findings on contribution and endangerment. 74 FR 66496 

(December 15, 2009). Thus, EPA is required to issue 

standards applicable to emissions of this air 

pollutant from new motor vehicles. 

 The Court properly noted that EPA retained 

"significant latitude" as to the "timing ... and 

coordination of its regulations with those of other 

agencies" (id.). However it has now been nearly three 

years since the Court issued its opinion, and the time 

for delay has passed. In the absence of these final 

standards, there would be three separate federal and 

state regimes independently regulating light-duty 

vehicles to increase fuel economy and reduce GHG 

emissions: NHTSA’s CAFE standards, EPA’s GHG 

standards, and the GHG standards applicable in 

California and other states adopting the California 

standards. This joint EPA-NHTSA program will allow 

automakers to meet all of these requirements with a 

single national fleet because California has indicated 

that it will accept compliance with EPA’s GHG 

standards as compliance with California's GHG 

standards. 74 FR at 49460. California has not 

indicated that it would accept NHTSA’s CAFE standards 

by themselves. Without EPA’s vehicle GHG standards, 

the states will not offer the federal program as an 

alternative compliance option to automakers and the 

benefits of a harmonized national program will be 

lost. California and several other states have 

expressed strong concern that, without comparable 

federal vehicle GHG standards, the states will not 

offer the federal program as an alternative compliance 

option to automakers. Letter dated February 23, 2010 

from Commissioners of California, Maine, New Mexico, 

Oregon and Washington to Senators Harry Reid and Mitch 

McConnell (Docket EPA-HQ-OAR-2009-0472-11400). The 

automobile industry also strongly supports issuance of 

these rules to allow implementation of the national 

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program and avoid “a myriad of problems for the auto 

industry in terms of product planning, vehicle 

distribution, adverse economic impacts and, most 

importantly, adverse consequences for their dealers 

and customers.” Letter dated March 17, 2010 from 

Alliance of Automobile Manufacturers to Senators Harry 

Reid and Mitch McConnell, and Representatives Nancy 

Pelosi and John Boehner (Docket EPA-HQ-OAR-2009-0472-

11368). Thus, without EPA’s GHG standards as part of 

a federal harmonized program, important GHG reductions 

as well as benefits to the automakers and to consumers 

would be lost.165 In addition, delaying the rule would 

impose significant burdens and uncertainty on 

automakers, who are already well into planning for 

production of MY 2012 vehicles, relying on the ability 

to produce a single national fleet. Delaying the 

issuance of this final rule would very seriously 

disrupt the industry’s plans 

Instead of delaying the LDV rule and losing the 

benefits of this rule and the harmonized national 

program, EPA is directly addressing concerns about 

stationary source permitting in other actions that EPA 

is taking with regard to such permitting. That is the 

proper approach to address the issue of stationary 

source permitting, as compared to delaying the 

issuance of this rule for some undefined, indefinite 

time period. 

75 FR____ (May 7, 2010) (footnote omitted). 

9. “Administrative Necessity” Basis for PSD and Title V 

Requirements in Tailoring Rule 

EPA believes that the “administrative necessity” doctrine, 

within the Chevron framework, also justifies this rulemaking. 

Applying the applicability requirements of the PSD and title V 

programs according to a literal reading of their terms (as EPA 

has narrowed them in the past through interpretation) to GHG 

sources beginning on the January 2, 2011 date that regulation of 

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GHGs takes effect would sweep so many sources into those 

programs as to render the programs impossible for the permitting 

authorities to administer. Although streamlining the PSD and 

title V programs offers some promise to improve the 

administrability of the programs, given the time needed to 

implement such streamlining, the step-by-step expansion of PSD 

and title V requirements to GHG sources that we are promulgating 

is the most that the permitting authorities can reasonably be 

expected to administer. 

This section discusses the application of the 

“administrative necessity” doctrine. Our views concerning this 

doctrine remain similar to what we said at proposal, except that

in this rulemaking we place the doctrine more clearly in the 

Chevron analytical framework, we revised our assessment of the 

administrative burdens due to new analysis we have conducted and 

information we have received since proposal, and we make certain

revisions we made to the tailoring approach. This analysis and 

information, as well as the revisions to the tailoring approach,

have already been presented previously, in the discussion of the 

“absurd results” basis. In addition, it is not necessary to 

reiterate the lengthy discussion of the “administrative 

necessity” doctrine that we included in the proposal or the 

factual data presented previously; as a result, this section 

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briefly and highlights the conclusions we have reached about the 

application of this doctrine. 

 As noted previously, under the PSD and title V 

applicability provision – read literally, as we have long 

interpreted them -- EPA’s recent promulgation of the light-duty 

vehicle rule will trigger the applicability of PSD and title V 

for GHG sources at the 100/250 tpy and 100 toy threshold levels,

respectively, as of January 2, 2011. This is because PSD 

applicability hinges on the definition of “major emitting 

facility” and title V applicability hinges on the definition of 

“major sources,” and those terms, read literally, and under 

EPA’s long-standing narrowing interpretation, apply PSD and 

title V, respectively, to sources of any air pollutant that is 

subject to regulation under another provision of the CAA. EPA’s 

promulgation of the light-duty vehicle rule means that GHGs will 

become subject to regulation on the date that the rule takes 

effect, which will be January 2, 2011. 

 Absent tailoring, the January 2, 2011 trigger date for GHG 

PSD applicability will give rise to see an extraordinarily large 

number of PSD permitting actions – we estimate more than 81,000 

per year – representing an increase of almost 300-fold over the 

current 280 PSD permitting actions each year. In addition, over 

6 million sources will become subject to title V, an increase of 

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more than 400-fold over the 14,700 sources that currently are 

subject to title V. The permitting authorities will find it 

impossible to administer programs of these sizes as of that 

date.

 All this results from a literal application of the PSD and 

title V applicability provisions to GHG sources. However, under 

Chevron, we must interpret and apply statutory requirements on 

the basis of congressional intent. Although the literal meaning 

of the statutory provisions is the first and generally the best 

indicator of congressional intent, there are cases in which that 

is not so. As discussed previously, we believe that as a 

general matter, statutory directives should be considered to 

incorporate Congress’s intent that they be administrable, and we 

believe that this proposition is implicit in the “administrative 

necessity” doctrine that the D.C. Circuit has established and 

that we believe applies here. See Alabama Power v. Costle, 636 

F.2d 323, 356-57 (D.C. Cir. 1980). This doctrine authorizes EPA 

to undertake a process for rendering the PSD and title V 

requirements administrable. Indeed, the Court in Alabama Power 

established this doctrine specifically in the context of the PSD 

provisions, including, in particular, the modification 

provision. As noted elsewhere, the Court held that EPA may 

“consider the administrative burden” associated with applying 

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PSD for emissions increases, and establish significance levels 

designed to avoid “severe administrative burdens on EPA, as well 

as severe economic burdens” on sources. Id. at 405.

 As we said in the proposal, read the caselaw to establish a 

three-step approach for implementing the “administrative 

necessity” doctrine: An agency is not required to adhere to 

literal statutory requirements if the agency, as the first step, 

makes every effort to adjust the requirements within the 

statutory constraints, but concludes with justification – at the 

second step – that it would be impossible to comply with the 

literal reading of the statute. Under those circumstances, the 

agency may – at the third step – develop what is in effect a 

compliance schedule with the statutory requirements, under which 

the agency will implement the statute as much as 

administratively possible and as quickly as administratively 

possible. See 74 FR 55,315/1 – 55,316/3.

a. First Step of the “Administrative Necessity” Analysis: 

Streamlining

 In the proposed rulemaking, EPA discussed at length the 

prospect of streamlining both PSD and title V. EPA described 

“several potentially useful tools available in the streamlining 

toolbox for the PSD permitting threshold level, the PSD 

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significance level, and the title V permitting threshold,” 

specifically – 

For the PSD permitting threshold level and 

significance level, there are at least three such 

tools: The first is interpreting the definition of 

"potential to emit" so that the amount of a source's 

emissions that counts in determining whether it 

qualifies as a major source and therefore is above the 

permitting threshold requirements is closer to the 

amount of its emissions when it is in actual 

operation, rather than the amount of emissions that 

the source would emit if it were operating 

continuously. Narrowing the definition of PTE is a 

potentially extremely important tool in this context 

because identifying the amount of a source's emissions 

as closer to its actual emissions in this manner would 

mean that very large numbers of residential and 

commercial sources would have significantly lower 

emissions and would fall below the statutory threshold 

requirements for triggering PSD. Second, EPA believes 

it may be able to develop programs involving general 

permits, under which large numbers of similarly 

situated sources would each be covered by essentially 

the same permit established through a regulatory 

action by the permitting authority. This approach 

could achieve economies of scale and thereby reduce 

administrative burden. Third, EPA believes it may be 

able to streamline the single most time-consuming 

element of the PSD permit program, which is the 

determination of BACT as required under CAA 

§165(a)(4), by establishing presumptive BACT levels 

for certain source categories that comprise large 

numbers of sources. As for title V, as discussed 

below in detail, EPA believes that defining "potential 

to emit" to reflect more closely a source's actual 

operation and developing a program of general permits 

could streamline the administration of title V 

permits. 

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 At proposal we stated that we would, and we still commit 

to, vigorously pursue development of these streamlining 

measures, and, as indicated in our discussion of streamlining 

methods in section V.E.1 and in response to comments, we have 

already begun developing those measures. For example, as 

described elsewhere, we have done much work – both with 

stakeholders and in-house -- to begin to develop recommendations 

for what controls would qualify as BACT for various industries. 

This work is important as a foundation for developing 

presumptive BACT, which is a potentially quite efficient 

streamlining measure. 

 However, it is not possible for us or the state and local 

permitting authorities to develop and implement streamlining 

techniques by the time that PSD and title V are triggered for 

sources emitting GHGs – January 2, 2011 -- or shortly 

thereafter. Developing streamlining methods would entail 

acquiring more information about the affected industry, may 

entail rulemaking, and would likely entail some type of public 

review of proposals for streamlining even if not done through 

rulemaking. As discussed in section VI.E, we do not expect that 

we could complete all those steps for meaningful streamlining 

measures within 2 years. 

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b. Second Step of the “Administrative Necessity” Analysis: 

Demonstration of Administrative Impossibility

 With no streamlining measures available at the time that 

PSD and title V would apply to sources of GHGs or shortly 

thereafter, under the second step of the “administrative 

necessity” analysis, we must determine whether implementation of 

the statutory requirements at that time would be 

administratively impossible for the permitting authorities. We 

are mindful that the D.C. Circuit has cautioned that this 

showing is a high hurdle. See 74 FR 55,317/3. 

 Even so, we believe there is no question that a literal 

application of the PSD and title V programs to GHG sources as of 

January 2, 2011 would be flatly impossible for the state and 

local permitting authorities to administer for at least an 

initial period of time.51 The key facts have been recounted 

previously, and no more than a brief recitation is necessary 

here. On the PSD side, annual permit applications would 

increase by over 300-fold, from 280 to 80,000; costs to the 

 51 We recognize that in a few states, we are the permitting 

authority. We do not think that this changes the calculation of 

administrative burdens. We do not believe that we could 

reasonably be expected to adjust our budget to accommodate the 

large new permitting burdens, and even if we could, the 

administrative burdens would remain in most of the rest of the 

nation where it is the state or local agencies that bear 

permitting responsibility. 

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successful in making such a 

showing, as we recognized in 

the proposal

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permitting authorities would increase more than 100-fold, from 

$12 million to $1.5 billion; and the permitting authorities 

would need to hire, train, and manage 9,772 FTEs. For title V, 

total permit applications would increase by over 400-fold, from 

14,700 to 6.1 million; costs to the permitting authorities would 

increase from $62 million to $21 billion; and the permitting 

authorities would need to hire, train, and manage 229,118 FTEs. 

 We have elaborated upon these burdens elsewhere in this

notice. They bespeak an impossible administrative task. It is 

not hyperbole to say that if these administrative 

responsibilities are not considered impossible within the 

meaning of the “administrative necessity” doctrine, then it is 

difficult to imagine what would be considered impossible. 

c. Third Step of the “Administrative Necessity” Analysis: 

Tailoring

 Under the third step of the “administrative necessity” 

analysis, we must demonstrate that the steps we intend to take 

towards implementation of the statutory requirements are the 

most that can be done during the indicated time frames, in light 

of administrative resources. In this manner, we adhere most 

closely to the statutory requirements. See 74 FR 55318/2. This 

amounts to establishing a schedule for phasing in PSD and title 

V applicability to GHG sources. Because this step is based on 

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amount, 

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they justify our conclusion 

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the administrative resources of the permitting authorities, our 

analysis is similar, and leads to the same conclusions, as we 

described previously concerning the “absurd results” basis. 

That is, we believe that our tailoring approach – including step 

1, to be implemented as of January 2, 2011; step 2, to be 

implemented as of July 1, 2011; the additional rulemaking that 

we commit to finalize by July 1, 2012, and that will address 

further threshold reductions as a step 3; the study and 

subsequent rulemaking to address smaller sources by April 30, 

2016; and the determination not to lower the threshold below 

50,000/50,000 tpy CO2e before April 30, 2016 at the earliest -- 

is the most that we can do to expand the PSD and title V 

programs, based on administrative resources and the information 

we currently have about the prospects for streamlining and 

increasing permitting resources.

 As noted preciously, at some point in the process of 

additional rulemaking, we may conclude under the “absurd 

results” doctrine that we will not apply PSD or title V to GHG 

sources below a certain size level. The same conclusion may be 

supportable under the “administrative necessity” doctrine if we 

decide, based on the information available to us, that even with 

all of the streamlining that we are able to accomplish and even 

with a significant expansion of permitting resources, it may not 

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be administratively feasible to implement PSD or title V to 

sources below that level. See Alabama Power v. Costle, 636 F.2d 

at 358 (acknowledging, in discussing the “administrative 

necessity” doctrine, that “[c]ategorical exemptions from the 

clear commands of a regulatory statute [are] sometimes 

permitted,” although emphasizing that such exemptions “are not 

favored”).

 In addition, as noted above, in a subsequent rulemaking, we 

may conclude that title V should not apply to GHG sources with 

“empty permits,” under the “absurd results” doctrine. The basis 

for this conclusion could be a determination that (i) although 

the applicability provisions apply by their terms to sources on 

the basis of their emissions, and without regard to whether the 

sources would hold empty permits, those provisions cannot be 

read literally under the “absurd results” doctrine; and (ii) it 

is not clear whether Congress intended that title V apply to 

such sources, and EPA has reasonably determined, under Chevron

step 2, that title V does not. If we come to that conclusion, 

then, at that point in time, the “administrative necessity” 

doctrine would remain relevant for title V purposes only if is 

necessary, for administrative reasons, to phase-in the 

application of title V to GHG sources that have applicable 

requirements, and that therefore do not have empty permits. 
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This is because the “administrative necessity” doctrine is 

relevant only when a statutory directive, read literally, 

imposes impossible administrative obligations, and Congress may 

be presumed to have intended that the directive be 

administrable. The “administrative necessity” doctrine would 

not come into play if it is concluded either that under the 

“absurd results” doctrine Congress did not intend the statutory

directive or that, under that doctrine, Congress’s intent was 

not clear and EPA reasonably decided that the directive does not 

apply. 

10. “One-Step-at-a-Time” Basis for Tailoring Rule 

 In addition to the “absurd results” and “administrative 

necessity” doctrines, the “one-step-at-a-time” judicial 

doctrine, within the Chevron framework, supports EPA’s Tailoring 

Rule. The caselaw under this doctrine, described previously, 

indicates that the doctrine justifies an agency’s step-by-step 

approach under the following circumstances or conditions: (i) 

the agency’s ability to comply with a statutory directive 

depends on facts, policies, or future events that are uncertain; 

(ii) the agency has estimated the extent of its remaining 

obligation; (iii) the agency’s incremental actions are 

structured in a manner that is reasonable in light of the 

uncertainties; and (iv) the agency is on track to full 

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compliance with the statutory requirements. EPA’s tailoring 

rule fulfills each of those four. 

 First, as the D.C. Circuit stated in National Association 

of Broadcaster v. FCC, 740 F.2d 1190, 1210 (D.C. Cir. 1984) 

(“National Association of Broadcasters”), incremental agency 

action is most readily justifiable “against a shifting 

background in which facts, predictions, and policies are in flux 

and in which an agency would be paralyzed if all the necessary 

answers had to be in before any action at all could be taken.” 

Those circumstances are present here, and so is that fact that 

the task at hand is extraordinarily demanding. As discussed 

previously, EPA and the permitting authorities’ progress in 

implementing the PSD and title V programs for GHG sources will 

depend in large measure on the development of streamlining 

measures and increases in permitting authorities’ resources, and 

those things carry some uncertainty and in any event, under the 

best of circumstances, cannot have much impact for at least 

several years. It will take EPA that long to develop 

streamlining measures, and it will take permitting authorities 

that long to begin to raise money and hire and train FTEs. 

 Second, as the Court stated in National Association of 

Broadcasters, “the agency [should] ma[k]e some estimation, based 

upon evolving economic and technological conditions, as to the 
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nature and magnitude of the problem it will have to confront 

when it comes to [undertake the remaining steps]” and that 

estimation must be “plausible and flow from the factual record 

compiled.” Id. at 1210. Here, EPA has done this by estimating 

the number of PSD and title V permits and the costs of issuing 

them, and has provided as much information as possible about the 

development of streamlining methods and permitting authority 

resources.

 Third, again as the Court stated in National Association of 

Broadcasters, it must be “reasonable, in the context of the 

decisions made in the proceeding under review, for the agency to 

have deferred the issue to the future. With respect to that 

question, postponement will be most easily justified when an 

agency acts against a background of rapid technical and social 

change and when the agency’s initial decision as a practical 

matter is reversible should the future proceedings yield 

drastically unexpected results.” Id. at 1211. Here, our 

tailoring approach is reasonable in light of changes in 

permitting authority capacity that may occur with the 

development of streamlining methods and increased resources. In 

addition, the first two steps that EPA promulgates today are 

reasonable initial steps that we expect to build on by lowering 

thresholds, as appropriate, in the future. We have no reason to 
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suspect that we may need to reverse either of the first two 

steps. Having received and analyzed extensive comment on the 

number of permitting actions to expect and on permitting 

authority resources, we consider it unlikely that we would need 

to establish a higher threshold level than what we have 

established in steps 1 and 2. In addition, if we were to adopt 

an “empty permits” approach for title V, we would not need to 

reverse either of steps 1 and 2, as explained above.

Finally, as the D.C. Circuit stated in Grand Canyon Air 

Tour Coalition v. F.A.A., 154 F.3d 455, 477-78 (D.C. Cir. 1998), 

the Courts will accept an initial step towards full compliance 

with a statutory mandate, as long as the agency is headed 

towards full compliance, and we believe that the doctrine is 

applicable here. EPA intends to require full compliance with 

the CAA applicability provisions of the PSD and title V 

programs, but we believe that in the case of GHG-emitting 

sources, by application of the “absurd results” doctrine or the 

“administrative necessity” doctrine, full compliance with the 

applicability provisions does not necessarily mean full 
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compliance with the literal terms of those provisions.52 Rather, 

as we have explained elsewhere, in the case of GHG sources, full 

compliance may mean compliance with higher levels that are 

consistent with congressional intent, under the “absurd results” 

doctrine, or that are within the reach of permitting authorities 

in light of their administrative constraints, under the 

“administrative necessity” doctrine. This rulemaking 

constitutes a package of initial steps towards that full 

compliance, and, seen in that light, is supported by the “onestep-at-a-time” doctrine. 

 Even if the doctrine were found to apply only when an 

agency is committed to fully implementing statutory requirements 

according to their literal terms, we believe that the steps we 

promulgate in this notice would be considered valid under the 

one-step-at-a-time doctrine. This is because even if we are 

incorrect about the applicability of the “absurd results” and 

“administrative necessity” doctrines, so that GHG sources are 

required to comply with the literal terms of the PSD and title V 

applicability provisions, the “one-step-at-a-time” doctrine 

 52 For reasons explained elsewhere, our reference to the 

literal terms of the applicability provisions means the literal 

terms of the definition of “major emitting facility” for PSD and 

“major source” for title V, as EPA has narrowed those 

definitions to refer to “any pollutant” that is subject to 

regulation under the CAA. 

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would allow PSD and title V applicability to be phased in, and 

the first two steps we promulgate in this notice would be upheld 

as reasonable initial steps toward full compliance with the 

literal terms of the CAA. As we have described elsewhere, there 

is little question but that sources and permitting authorities 

cannot reasonably be expected to comply with or implement PSD 

and title V applicability requirements in the near term – by 

January 2, 2011 and July 1, 2011 -- except to the limited extent 

described under steps 1 and 2. Nor is applicability of the PSD 

and title V requirements at levels below 50,000 tpy CO2e 

reasonable before 6 years from promulgation of this rule, as 

discussed elsewhere. If further steps resulting in full 

compliance with the literal terms of the applicability 

provisions of PSD and title V were required, it would be 

reasonable for those steps to occur in the future, as part of 

the rulemaking to be completed by the sixth year after 

promulgation, to which EPA commits itself as part of this

action, or as part of subsequent actions. See Grand Canyon Air 

Tour, 891 F.2d at 476-77 (upholding agency action as a step 

towards full compliance with statutory mandate when the agency 

expected full compliance to occur some 20 years after the 

deadline in the statute). 

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C. Mechanisms for Implementing and Adopting the Tailoring 

Approach

In this section, we discuss three issues related to 

adoption of the tailoring approach within our regulations and by 

permitting agencies. The first is the regulatory mechanism for 

implementing the tailoring approach – that is, the specific way 

we are revising the PSD and title V applicability provisions to 

incorporate the tailoring approach – and our rationale. The 

second is the process by which state or local permitting 

authorities may incorporate the tailoring approach into their 

PSD SIP and title V permit programs. Finally, we discuss our 

reasons for delaying action on our proposal to limit approval of 

both SIP-approved PSD programs and title V programs, and we 

request certain information from states on both of their 

programs and their actions in response to this rule. 

In brief, we proposed to exempt sources emitting GHGs below 

certain threshold levels from the definition of the regulatory 

terms “major stationary source” and “major modification” in PSD 

programs and the definition of the regulatory term “major 

source” in title V programs. We further proposed to effectuate 

this change in SIP-approved PSD programs (as included in SIPs) 

and EPA-approved part 70 title V programs by limiting our prior 

approval of those programs to the revised applicability 

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thresholds for GHGs.53 These changes would have the effect of 

putting the higher thresholds adopted under the Tailoring Rule

in place in states PSD and title V programs as a matter of 

federal law. However, state commenters expressed concern that 

they would not be able to adopt the Tailoring Rule under state 

laws on an expeditious basis. To address this, our final action 

differs from our proposed rule in the way we incorporate the 

limitations promulgated in this Tailoring Rule into the “major 

stationary source,” “major modification” and “major source” 

definitions. This approach relies on further defining the term 

“subject to regulation” and although this approach is not 

substantively different in effect from the proposed rule, it 

will facilitate more rapid adoption and implementation of the 

Tailoring Rule by states through interpretation of language in 

existing state regulations. We believe these difference are a 

logical outgrowth of our proposed rule. We are also delaying 

action on our proposed limited approval of EPA-approved PSD

programs and part 70 title programs to determine how each state 

will implement the final rules. 

1. PSD Approach: Background and Proposal 

 53 In the alternative, we also proposed to use our 

110(k)(6) error correction authority to revise SIP-approved PSD 

program. We are also delaying action on this proposal. 

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Under CAA §165(a), no “major emitting facility” may 

construct or modify unless it receives a preconstruction permit 

that meets the requirements of the PSD program. CAA §169(1) 

defines a major emitting facility as “any ... source[]” in one of 

28 specified source categories that “emit[s], or ha[s] the 

potential to emit, one hundred tons per year or more of any air 

pollutant;” or “any other source with the potential to emit two 

hundred and fifty tons per year or more of any air pollutant.” 

EPA’s regulations replace the term “major emitting facility” 

with the term “major stationary source” and define the term as 

“[a]ny of ... [28 types of] stationary sources of air pollutants 

which emits, or has the potential to emit, 100 tons per year or 

more of any regulated NSR pollutant” or “any stationary source 

which emits, or has the potential to emit 250 tons per year or 

more of a regulated NSR pollutant.” 40 CFR 51.166(b)(1)(i)(a)-

(b). The term “regulated NSR pollutant” is defined to include, 

among other things, “any ... air pollutant that otherwise is 

subject to regulation under the Clean Air Act.” 40 CFR 

51.166(b)(50). Note that the regulatory definition in effect 

interprets the statutory definition more narrowly to read “one 

hundred [or two hundred and fifty] tons per year or more of any 

air pollutant subject to regulation under the Clean Air Act” 

(emphasis added). 

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Similarly, under the statute, a modification occurs if 

there is a physical change or change in the method of operation 

“which increases the amount of any air pollutant emitted . . .” 

CAA section 165(a), 169(2)(c), 111(a)(4). As with the major 

stationary source definition, we have limited coverage of the 

modification provision to physical changes or changes in the 

method of operation that result a significant net emissions 

increase in emissions of a “regulated NSR pollutant.” 40 CFR 

51.166(b)(2)(i). 

Our proposed rule revised the definition of “major 

stationary source to 1) exempt GHG from the regulated NSR 

pollutants that, if emitted by a source in the 100 or 250 tpy 

quantities, would cause the source to qualify as a “major 

stationary source,” and 2) add a specific threshold at which a 

source that emits a specified quantity of GHGs (at proposal, 

that quantity was 25,000 tpy CO2e) would qualify as a “major 

stationary source.” 74 FR 55,351, proposed 40 CFR 

51.166(b)(1)(i)(a), (b), (d). We also proposed a significance 

threshold, which is the amount of an increase needed to trigger 

PSD for a modification or to require BACT for a new source, at a 

level between 10, 000 and 25,000 tpy CO2e. 74 FR 55351 40 CFR 

51.166(b)(23)(i). 

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Additionally, we recognized that it may take some time 

before states could change their SIP-approved PSD programs and 

that as a result, absent additional action on our part, GHGemitting sources would remain subject to the 100 or 250 tpy 

thresholds, and subject to a zero significance threshold for 

major modifications as a matter of federal law. To address this 

issue, we proposed to narrow our previous approval of those 

SIPs. The effect of our proposal would be that EPA would have 

approved the SIP PSD programs only to the extent they apply PSD 

and requirements to GHG sources at or above the thresholds 

established in the tailoring rule (which, generally, were 25,000 

tpy CO2e), and EPA would have taken no action on the SIP PSD 

programs to the extent they apply PSD requirements to GHG 

sources below that threshold. We relied on the authority of the 

APA and the general authority of CAA §301 and, in the 

alternative, on the error correction mechanism under CAA section 

110(k)(6). Our limited approval would revise existing EPAapproved SIP PSD programs to authorize permitting under the CAA

only for GHG sources at the appropriate levels. 

In response to our proposed approach, we received numerous 

comments from state and local permitting agencies expressing 

significant concern. The observed that our proposed approach 

could meet its objectives to avoid applying PSD requirements to 

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small sources under federal law, but would not succeed in 

avoiding the application of PSD requirements to those small 

sources under state law. The commenters explained that, 

although EPA was changing federal PSD applicability thresholds;

for GHG-emitting sources to incorporate the tailoring approach, 

and limiting the scope EPA approval of SIPs consistent with 

these thresholds, the state rules containing the originallyapproved SIP thresholds would continue to apply as a matter of 

state law. As commenters explained, for the most part, the laws 

and regulations states adopt to implement federal PSD programs 

mirror EPA’s regulations, so that the state laws, apply PSD to 

sources that emit air pollutants subject to regulation at the 

100/250 tpy threshold. Commenters reasoned that, until the 

states can change their state laws, the 100/250 tpy thresholds 

will continue to apply as a matter of state law, even though the 

higher thresholds apply as a matter of federal law. 

Importantly, these commenters emphasized, their state process 

requires that they promulgate a rulemaking, or in some cases, a 

legislative change, to incorporate the higher thresholds for GHG 

sources in their SIPs. These processes would require many 

months and in some cases as long as 2 years. As a result, 

sources that emit GHGs below the federally established levels in 

the final rule, but at our above the 100/250 tpy levels in state 

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recognized in the proposed 

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existing State law. Rather, 

as 

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laws and rules, would still be required to obtain PSD permits 

under state law. As a result, states, in attempting to 

implement state permitting requirements, would be faced with the 

same administrative difficulties that EPA recognized in the 

proposed rule as impossible. Commenters emphasized that this 

situation was untenable. 

In addition to the state comments just described, we 

received comments that took issue with our view that we were in 

effect revising the numerical thresholds for PSD applicability 

as the legal mechanism for the tailoring approach. They 

asserted that in fact, our mechanism consisted of interpreting 

the term “any source” to exclude small GHG-emitting sources. 

Other commenters objected to our proposed mechanism of narrowing 

our previous SIP approval, arguing that this mechanism was 

without legal basis. 

2. Rationale for Our Final Approach to Implementing PSD 

In response to these concerns, we are adding another 

mechanism to implement the tailoring approach for PSD, and that 

is to interpret, within our PSD regulations, the phrase “subject 

to regulation,” as found within the phrase “any regulated NSR 

pollutant,” which, in turn, is part of the definitions of “major 

stationary source” and “major modification.” To implement this 

mechanism, we are codifying in our regulations an interpretation 

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of “subject to regulation” so that the GHGs emitted by sources 

that fall below the thresholds or scope established in steps 1 

and 2 are not treated as “subject to regulation,” and therefore 

do not trigger PSD for the sources that emit them. 

To understand this approach, it is useful to return to the 

definition of “major stationary source,” which, again, is 

central to PSD applicability. The definition, quoted 

previously, employs the term “regulated NSR pollutant,” which is 

a defined term. The definition incorporates many other elements 

as well (e.g., the 100/250 threshold requirements), but for 

convenience, we quote it as follows: a “major stationary 

source” is “[a]ny ... source[] of air pollutants, which emits, or 

has the potential to emit, [depending on the source category, 

either] 100 [or 250] tons per year or more of any air pollutant 

that is subject to regulation under the Clean Air Act.” 40 CFR 

51.166(b)(1)(i(a)-(b). Applying our definition of “subject to 

regulation” to exclude GHG sources that emit below specified 

thresholds, the definition may not be paraphrased as follows: A 

“major stationary source” is any source of air pollutants, which 

emits, or has the potential to emit, depending on the source 

category, either 100 or 250 tons per year or more of any air 

pollutant subject to regulation under the CAA, except that the 

source’s GHGs are considered to be subject to regulation under 

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above and applying

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the CAA only the extent indicated under steps 1 and 2 of the 

tailoring rule, e.g., for step 2, only if the source’s GHG 

emissions exceed the threshold established in step 2. We adopt 

the same approach for the definition of the regulatory term

“major modification.” 

Although EPA is codifying its interpretation of “subject to 

regulation” by revising its regulations, we have been advised 

that states may be able to adopt our approach without having to 

undertake a rulemaking action to revise their SIP regulations or 

without requiring an act of the state legislature. Instead, it 

is our understanding that states may adopt our approach by 

interpreting their SIPs to have the same meaning for the term 

“subject to regulation” that we are including in our regulations 

in this rulemaking. We believe that States can rely on an 

interpretation because we view the term “subject to regulation” 

as open-ended, and therefore amenable to interpretation. This 

is particularly – although not exclusively -- the case in a 

state that has taken the position, or determines now, that the 

state’s definition of “subject to regulation,” or, more broadly,

“regulated NSR pollutant” or “major stationary source” or “major 

modification, is intended to be interpreted in a way that tracks 

the meanings that EPA has assigned to these phrases. Such

states can adopt the meaning of “subject to regulation” that we 

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emitted by sources below 

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established in 

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major modification now means 

“any physical change or 

change in 

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that would result in: a 

significant emissions 

increase . . . . of a 

regulated NSR pollutant . . 

but GHG are not subject to 

regulation under the Clean 

Air Act if emitted by 

sources below the thresholds 

established in steps 1 and 2 

and result in an increase 

less than the amounts 

specified therein.”¶

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permitting 

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their SIPs 

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establish in this rule by January 2, 2011, and thereby avoid the 

situation in which, as a matter of state law, GHG-emitting 

sources above the 100 or 250 tpy thresholds become subject to 

PSD by that date. The following explains our basis for 

concluding that the phrase “subject to regulation” is openended. 

First, we recently stated this position in our 

reconsideration of the Interpretive Memo. On December 18, 2008, 

EPA issued the Interpretive Memorandum, establishing EPA’s 

interpretation of the definition “regulated NSR pollutant” found 

at 40 CFR 52.21(b)(50) EPA intended this memorandum to resolve 

ambiguity in subpart (iv) of this definition, which includes 

“any pollutant that otherwise is subject to regulation under the 

Act.” Specifically, the memorandum stated that EPA will 

interpret the definition of “regulated NSR pollutant” to exclude 

pollutants for which EPA regulations only require monitoring or 

reporting but to include pollutants subject to either a 

provision in the CAA or regulation adopted by EPA under the CAA

that requires actual control of emissions of that pollutant. 

After reconsidering this interpretation through a formal 

notice-and-comment process, EPA refined its interpretation to 

establish that the PSD permitting requirements will not apply to 

a newly regulated pollutant until a regulatory requirement to 

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interpretation before 

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States can adopt this 

regulatory approach through 

an interpretation, rather 

than by a rulemaking action 

or state legislative 

process, because we view the 

phrase “regulated NSR 

pollutant” as open-ended, 

and therefore subject to 

interpretation, as the 

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demonstrates. 

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memorandum 

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control emissions of that pollutant “takes effect.” 75 FR

17704. Importantly, as stated previously, because the term 

“regulated NSR pollutant” is embedded within the definition of 

“major stationary source,” this interpretation effectively 

defines which major stationary sources are subject to PSD 

permitting. As a result, for example, EPA explained that PSD 

and title V permitting requirements for GHGs will not apply to 

GHGs until at least January 2, 2011, following the anticipated 

promulgation of EPA regulations requiring control of GHG 

emissions under Title II of the CAA. Id. 

 In the RTC document for EPA’s reconsideration of the PSD 

interpretative memorandum, we stated that, 

Absent a unique requirement of state law, EPA believes that 

state laws that use the same language that is contained in 

EPA’s PSD program regulations at 52.21(b)(50) and 

51.166(b)(50) are sufficiently open-ended to incorporate 

greenhouse gases as a regulated NSR pollutant at the 

appropriate time consistent with EPA’s interpretation of 

these regulations (emphasis added). (Docket ID No. EPA-HQOAR-2009-0597-0128). 

Because the SIP provisions that include EPA’s definition of the 

term “subject to regulation” in the reconsideration of the PSD 

interpretive memorandum are “sufficiently open-ended to 

incorporate greenhouse gases as a regulated pollutant,” those 

SIP provisions are also sufficiently open-ended to incorporate 

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because this final rule 

tailors the application of 

GHG permitting, GHG 

emissions at certain 

thresholds will not be 

“subject to regulation” as 

we interpret that term 

within the “regulated NSR 

pollutant” definition.

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the further refinement to “subject to regulation” that we make 

in this rulemaking.

 By the same token, EPA has historically interpreted certain 

state SIP-approved programs as sufficiently open-ended such that 

the rules provide for the “automatic assumption for the 

responsibility for review” of new pollutants before the general 

deadline for states to revise their PSD programs. See, e.g., 52 

FR at 24682. Conversely, we have also read federal rules and 

state SIPs to provide for the automatic removal of a pollutant 

when such pollutant is no longer “subject to regulation.” For 

example, the 1990 CAA amendments exempted HAPs listed in Section 

112(b)(1) from the PSD requirements. See CAA §112(b)(6). 

Following passage of the amendments, EPA issued “New Source 

Review (NSR) Program Transitional Guidance“, a memorandum from 

John S. Seitz, Director, Office of Air Quality Planning and 

Standards to Regional Air Division Directors on March 11, 1991. 

In that guidance, EPA interpreted its PSD regulations to 

automatically cease to apply to listed HAPs (with some noted 

exceptions), and implicitly stated that a state with an openended SIP-approved PSD rule could also take the position that 

its SIP rule automatically ceased to regulate HAPs. 

 After reviewing these past practices in the PSD permitting 

program, and EPA’s prior statements regarding pollutants subject 

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to the PSD program, we conclude that states with SIP rules that 

contain the same language as used in 40 CFR 52.21(b)(50) or 40 

CFR 51.166(b)(49), or that otherwise have sufficiently openended PSD regulations, would be able to implement our Tailoring 

Rule approach to permitting by interpreting their regulations, 

and without needing to promulgate a regulation or seek state 

legislative action. This is particularly – although not 

exclusively -- the case for states that take the position that 

they intend their rules to apply the same meaning as EPA's

counterpart rules. If states adopt this reading of their 

regulations, GHG sources falling below the specified cutoffs 

would not be emitting pollutants “subject to regulation” within 

the definition of “regulated NSR pollutant” and therefore would 

not be subject to PSD permitting as a major stationary source or 

for making a major modification. 

During our consideration of this action, we participated in 

teleconferences with six state and lone local agency permitting 

authorities to discuss this issue of whether they could 

implement the proposed rule without the need for state law or 

regulations changes or a revision of the provisions of state law 

that are a part of the SIP. [Placeholder: docket # for meeting 

summary] We specifically discussed whether defining the phrase 

“subject to regulation” would better facilitate state 

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approach to permitting of 

GHG sources without the need 

for a SIP revision if they 

establish that the state 

intended to apply the same 

meaning as EPA when it 

incorporated the term 

“subject to regulation” in 

its PSD program regulations

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local agency) 

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incorporation of the limitations in this final rule. The state 

and local agencies participating in the calls generally agreed 

that defining the phrase “subject to regulation” would, compared 

to our proposed approach, better facilitate state incorporation 

of the limitations in the final rule in states with regulations 

that mirror the existing federal rules, or in states whose rules 

are otherwise sufficiently open-ended to incorporate the 

limitations in the final rule by interpretation. Participants 

from each agency also indicated that their rules contain the 

term “subject to regulation” and that term has not been 

previously interpreted in ways that would preclude adoption of 

EPA’s meaning of the term by interpretation to allow for 

adoption. We therefore concluded it is likely the rules are 

sufficiently open-ended (although some states indicated they may 

elect to pursue rulemaking in addition to interpretation). 

Accordingly, we selected the “subject to regulation” regulatory 

approach as the mechanism for codifying the final rule. 

3. Other Mechanisms

As just described, we selected the “subject to regulation” 

mechanism because it most readily accommodated the needs of 

States to expeditiously revise – through interpretation or 

otherwise -- their state rules. Even so, it is important to 

recognize that this mechanism has the same substantive effect as 

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the definition of “regulated 

NSR pollutant” 

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open-ended to do so because 

they

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this tailoring rule

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the mechanism we considered in the proposed rule, which was 

revising numerical thresholds in the definitions of major 

stationary source and major modification. Most importantly, 

although we are codifying the “subject to regulation” mechanism, 

that approach is driven by the needs of the states, and our 

action in this rulemaking should be interpreted to rely on any 

of several legal mechanisms to accomplish this result. Thus, 

our action in this rule should be understood as revising the 

meaning of several terms in these definitions, including: (i) 

the numerical thresholds, as we proposed; (ii) the term, “any 

source,” which some commenters identified as the most relevant 

term for purposes of our proposal; (iii) the term, “any air 

pollutant; or (iv) the term, “subject to regulation.” The 

specific choice of which of these constitutes the nominal

mechanism does not have a substantive legal effect because each 

mechanism involves one or another of the components of the terms

“major stationary source” -- which embodies the statutory term, 

“major emitting facility” -- and “major modification,” which 

embodies the statutory term, “modification,” and it is those

statutory and regulatory terms that we are defining to exclude 

the indicated GHG-emitting sources.55 

 55 We also think that this approach better clarifies our 

long standing practice of interpreting open-ended SIP 

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Deleted: . Defining the term 

“subject to regulation”, has 

the effect of modifying the 

meaning of the regulatory 

terms “major stationary 

source” and “major 

modification” – again, the 

keys to PSD applicability – 

to exclude GHG-emitting 

sources below the thresholds 

established in Steps 1 and 

2, and our action 

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The thrust of this 

rulemaking is to apply the 

PSD definition of “major 

stationary source” – which 

embodies the statutory term, 

“major emitting facility” --

to GHG sources by treating 

only GHG sources that emit 

at levels above the steps 1 

and 2 thresholds as meeting 

that definition. Our action 

may reasonably be construed 

to have the effect of 

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regulation,” which, as 

discussed above, our 

regulations attach to the 

definition of “major 

stationary source” and 

“major modification

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have a substantive legal 

effect because each 

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“subject to regulation” 

mechanism facilitates 

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... [72]
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4. Codification of Interpretive Memo 

As noted previously, we recently affirmed and refined our 

interpretation of the term “subject to regulation” as it applies 

broadly to the PSD program through a formal notice and comment 

process. “Interpretation of Regulations that Determine 

Pollutants Covered by Clean Air Act Permitting Programs,” 75 FR 

17004. In the response to comments for that action, we 

indicated that we may opt to codify our interpretation of the 

term in this tailoring rulemaking. Accordingly, our final rule 

adopts this interpretation to bring additional clarity to our 

rules. Specifically, we are adding a new paragraph to the 

definition of the term “subject to regulation” that contains our 

existing interpretation of that term. We also are moving

existing exceptions (e.g. section 112 HAPs) to a new paragraph 

within the definition of "subject to regulation". This minor 

reorganization of these regulations is not intended to effect 

any change in how they are to be implemented, but merely 

simplifies and clarifies the regulations by clearly delineating 

different terms and concepts. 

 

regulations to automatically adjust for changes in the 

regulatory status of an air pollutant, because it appropriately 

assures that the tailoring rule applies to both the definition 

of “major stationary source” and “regulated NSR pollutant.” 

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Johnson}

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This codification of this interpretation of “subject to 

regulation” from the reconsideration for the PSD Interpretive 

Memo is not necessary to assure the effectiveness of the 

interpretation, and it does not disturb States’ existing 

authority to adopt the definition through interpretation of 

their existing rules. The codification does nothing more than 

simplify an clarify the regulatory language. 

5. Delaying Limited Approvals and Request for Submission of 

Information from States implementing a SIP-approved PSD program 

Because we now anticipate that many states will be able to 

implement our tailoring approach through interpretation of the 

term “subject to regulation,” and without the need to revise 

their SIPs, we are delaying further action on our proposal to 

limit our approval of SIPs until we better understand how 

permitting authorities will, in fact, implement our tailoring 

approach. For this purpose, we ask each state to submit a 

letter to the appropriate Regional Administrator no later than 

[INSERT DATE 60 DAYS AFTER PROMULGATION]. In that letter, the 

state should explain whether it will apply EPA’s meaning of the 

term “subject to regulation” and if so, whether the state 

intends to incorporate that meaning of the term through 

interpretation, and without undertaking a regulatory or 

legislative process. If a state must undertake a regulatory or 

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Deleted: We do not believe 

that

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that our action disturbs

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codify our existing 

interpretation is based 

solely on a desire to better 

inform readers of the 

existing interpretation. ¶

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legislative process, then the letter should provide an estimate 

of the time needed to adopt the final rules. If a state chooses 

not to adopt EPA’s meaning by interpretation, the letter should 

address whether the state has alternative authority to implement 

either our tailoring approach or some other approach that is at 

least as stringent, whether the state intends to use that 

authority. If the state does not intend to interpret or revise 

its SIP to adopt the tailoring approach or such other approach, 

then the letter should address the expected shortfalls in 

personnel and funding that will arise if the state attempts to 

carry out PSD permitting for GHG sources under the existing SIP

and interpretation. 

For any state that is unable or unwilling to adopt the 

tailoring approach by January 2, 2011, and that otherwise is

unable to demonstrate adequate personnel and funding, we will 

move forward with finalizing our proposal to limit our approval 

of the existing SIP. Although we received comments questioning 

our authority to limit approval as proposed, using our general 

rulemaking and 110(k)(6) authorities, we are not responding to 

those comments at this time. We will address these comments in 

any final action we take to implement a limited approval. 

In our proposed rule, we also noted that a handful of EPAapproved SIPs fail to include provisions that would apply PSD to 

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the Regional Administrator

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addresses 

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final rules 

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undertake a limited approval

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emissions to their 

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GHG sources when at the appropriate time. This is generally 

because these SIPs specifically list the pollutants subject to 

the SIP PSD program requirements, and do not include GHGs in 

that list, rather than include a definition of NSR regulated 

pollutant that mirrors the federal rule, or because the state 

otherwise interprets its regulations to limit which pollutants 

the state may regulate. At proposal, we indicated that we 

intended to take separate action to identify these SIPs, and to 

take regulatory action to correct this SIP deficiency. 

We ask any state or local permitting agency that does not 

believe its existing SIP provides authority to issue PSD permits 

to GHG sources to notify the Regional Administrator by letter, 

and to do so no later than [INSERT DATE 60 DAYS AFTER 

PROMULGATION]. This letter should indicate whether the state 

intends to undertake rulemaking to revise its rules to apply PSD 

to the GHG sources that will be covered under the applicability 

thresholds in this rulemaking, or alternatively, whether the 

state believes it has adequate authority through other means to 

issue federally-enforceable PSD permits to GHG sources 

consistent with this final rule. For any State that lacks the 

ability to issue PSD permits for GHG sources consistent with 

this final rule, we intend to undertake a separate action to 

issue a SIP call, under CAA section 110(k)(5). As appropriate, 

Deleted: regulations that EPA 

promulgates to regulate GHGs 

take effect and thereby 

trigger the applicability of 

PSD for sources that remain 

covered under today’s rule

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final rule 

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done

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described letter regarding 

adoption of the tailoring 

rule).

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Administrator

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we may also impose a FIP through 40 CFR section 52.21 to ensure 

that GHG sources will be permitted consistent with this final 

rule. 

6. Title V Programs

 Our final action also differs from the proposal in the 

specific regulatory mechanism by which we tailor the definition 

of “major source” for title V permit programs, but is a logical 

outgrowth of our proposed rule. EPA proposed to implement 

tailoring for GHGs under title V by excluding sources of GHGs 

from the general definition of “major source” under 40 CFR 70.2 

and 71.2, and adding a separate definition of “major source” 

with tailored thresholds for sources of GHGs. In response to 

comments, particularly from states concerned with implementation 

of the proposed approach under state law, EPA is adopting an 

approach in the final rule that 1) amends the definition of 

“major source” by codifying EPA’s longstanding interpretation 

that applicability for a “major stationary source” under CAA 

sections 501(2)(B) and 302(j) and 40 CFR 70.2 and 71.2 is 

triggered by sources of pollutants “subject to regulation,” and 

2) adding a definition of “subject to regulation.” Further, we 

are delaying our action to move forward with limiting our 

previous approval of existing state part 70 programs. 

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 We finalize this alternative approach to address concerns 

similar to those we received with respect to state 

implementation of SIP-approved PSD programs. Specifically, we 

received comments that the mechanism we proposed would not 

address the significant administrative and programmatic 

considerations associated with permitting GHGs under title V, 

because the 100 tpy threshold would continue to apply as a 

matter of state law. Commenters stated that states would need 

to undertake a regulatory and/or legislative process to change 

the threshold in their state laws which they could not complete 

before the laws would otherwise require issuance of operating 

permits to GHGs sources. After considering the commenters’ 

concerns, we are finalizing an approach designed to address the 

state law concerns for states. As a result, it is unnecessary 

to move forward at this time with our proposed approach to limit 

approval of existing part 70 programs in many states. 

 EPA’s approach involves the interrelationship of terms 

within the part 70 definition of “major source” in title V and 

EPA’s implementing regulations, and EPA’s historical practice of 

interpreting the term “any air pollutant” in the “major 

stationary source” component of that definition. EPA believes 

the approach in the final rule will allow many states to adopt 

the final rule through interpretation of existing state laws. 

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that it may be 

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Specifically, paragraph (3) within the definition of “major 

source” found in 40 CFR 70.2 and 71.2 defines a major source as 

a “a major stationary source of air pollutants, as defined in 

section 302 of the Act, that directly emits or has the potential 

to emit, 100 tpy or more of any air pollutant...” The EPA 

previously articulated the Agency’s interpretation that the 

regulatory and statutory definitions of “major source” under 

title V, including the term “any air pollutant,” applies to 

pollutants “subject to regulation.” Memorandum from Lydia N.

Wegman, Deputy Director, Office of Air Quality Planning and 

Standards, U.S. EPA, to Air Division Directors, “Definition of 

Regulated Air Pollutant for Purposes of Title V” (April 26, 

1993) (Wegman Memo). EPA recently re-affirmed this position in 

EPA’s Reconsideration of Interpretation of Regulations that 

Determine Pollutants Covered by Clean Air Act Permitting 

Programs. 75 FR 17704, 17022-23 (April 2, 2010) (Interpretive 

Memorandum Reconsideration Final Action). 

 Accordingly, under our long-established policy, states

historically have interpreted the term “any air pollutant” under 

the title V definition of “major source” to mean any pollutant 

“subject to regulation” under the Act. Thus, as a matter of 

established interpretation, EPA and states effectively read the 

definition of “major source” under title V to include a source 

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“...that directly emits or has the potential to emit, 100 tpy or 

more of any air pollutant subject to regulation under the Act”

[emphasis added]. By amending our regulations to expressly 

include and define “subject to regulation” to implement our 

tailoring for GHGs under title V, we are seeking to enable 

states to adopt and implement this approach through a continued 

interpretation of the phrase “any air pollutant” within the 

“major source” definition, without the need for changes to state 

regulations or statutes. States may be able to track EPA’s 

approach to tailoring for GHG permitting without regulatory or 

statutory changes, for example, where a state has taken the 

position, or determines now, that the state’s interpretation of 

“major source,” “subject to regulation” and/or “any air 

pollutant” is intended to track EPA’s interpretation. 

 Thus, EPA is adding the phrase “subject to regulation” to 

the definition of “major source” under 40 CFR 70.2 and 71.2. 

EPA is also adding to these regulations a definition of “subject 

to regulation.” Under the part 70 and part 71 regulatory 

changes adopted, the term “subject to regulation,” for purposes 

of the definition of “major source,” has two components. The 

first component codifies the general approach EPA recently 

articulated in the “Reconsideration of Interpretation of 

Regulations That Determine Pollutants Covered by Clean Air Act 

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Permitting.” 75 FR 17704. Under this first component, a 

pollutant “subject to regulation” is defined to mean a pollutant 

subject to either a provision in the CAA or regulation adopted 

by EPA under the CAA that requires actual control of emissions 

of that pollutant and that has taken effect under the CAA. See 

id. at 17022-23; Wegman Memo at 4-5. To address tailoring for 

GHGs, EPA includes a second component of the definition of 

“subject to regulation,” specifying that GHGs are not subject to 

regulation for purposes of defining a major source, unless as of 

July 1, 2011, the emissions of GHGs are from a source emitting 

or having the potential to emit 100,000 tpy of GHGs on a CO2e 

basis. 

 As explained previously, we find no substantive difference 

between the alternative mechanisms for implementing GHG 

tailoring in the final rule. Whether we add GHG thresholds 

directly to the definition of “major source” (as we proposed), 

or alternatively, expressly add and define the term “subject to 

regulation,” both approaches revise the definition of “major 

source” to implement the GHG Tailoring Rule. Accordingly, we 

adopt the later approach to facilitate state implementation of 

the final rule through an interpretation of existing state part

70 programs. Similar to our explanation previously for PSD, 

while we adopt the “subject to regulation” mechanism for 

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implementing GHG tailoring in the final rule, the thrust of our 

rulemaking is to apply the title V definition of “major source” 

– which includes the statutory term, “major stationary source” - 

to GHG sources by treating only GHG sources that emit at levels 

above the steps 1 and 2 thresholds as meeting that definition. 

Further, we believe that our action may reasonably be construed 

to revise any of several terms in that definition, including (i) 

the numerical thresholds, as we proposed; (ii) the term “any air 

pollutant,” (iii) the term “a major stationary source,” (iv) the 

term “subject to regulation,” which, as discussed previously, 

our regulations graft into the definition of “major source.” We 

believe that the specific choice of which term constitutes the 

legal mechanism does not have a substantive legal effect because 

each mechanism involves one of the components of the regulatory 

term “major source” – which embodies the meaning of the 

statutory term, “major source” -- and it is that term that we 

are interpreting to tailor title V applicability for GHGemitting sources. Thus, while the “subject to regulation” 

mechanism facilitates expeditious implementation by states, and 

we are therefore revising our regulations to adopt this 

approach, we otherwise find no substantive difference between 

the alternative mechanisms we may use to finalize the proposed 

rule. 

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Further, similar to our revised approach for addressing 

state SIP-approved PSD programs, we are delaying our action to 

limit our previous approvals for state part 70 operating permit 

programs. In our proposed rule, we explained our concern that 

states lack adequate personnel and resources to carry out part 

70 operating permit programs for GHG sources that emit or have 

the potential to emit 100 tpy of GHGs. Accordingly, we proposed 

to use our general rulemaking authority under section 301(a) of 

the CAA and APA section 553 to limit our prior approval of state

operating permit programs. This limited approval action would 

have had the effect of applying CAA permitting requirements only 

to sources that exceed the permitting thresholds established in 

this rule for the phase-in, because only those sources would be 

covered by the federally approved part 70 programs. 74 FR at 

55345. As discussed previously, we are proceeding with a 

slightly revised approach to address concerns similar to those 

raised with our proposed approach for addressing SIP-approved 

PSD permit programs. Because we now recognize that, like the 

PSD program, many states will be able to implement the final 

rules without the need to revise their existing part 70 

operating permit programs, we are delaying further action on our 

proposal to limit approval of existing part 70 programs until we 

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better understand how permitting authorities will implement our 

final rule. 

In addition to the information requested previously on SIPapproved PSD permit programs, we ask each state to submit a 

letter to the appropriate Regional Administrator no later than 

[INSERT DATE 60 DAYS AFTER PROMULGATION] detailing the state’s 

plan for permitting of GHG sources under the state’s part 70 

program. In that letter, states should explain whether they 

will adopt an interpretation of the terms “major source” or any 

of its component terms – “a major stationary source,” “any air 

pollutant,” or “subject to regulation,” or the numeral 

thresholds -- that is consistent with EPA’s regulatory 

interpretation of the these terms as codified at 40 CFR 70.2, 

and whether the state intends to adopt the interpretation 

without undertaking a regulatory or legislative process. This 

approach may be available, for example, where a state has taken 

the position, or determines now, that the state’s interpretation 

of these terms is intended to track EPA’s interpretation, 

resulting in title V permitting for sources of GHGs as described 

in EPA’s regulations adopted in this rule. If a state must 

revise its title V regulations or statutes to implement the 

interpretation, we ask that it provides an estimate of the time 

to adopt final rules or statutes in its letter to the Regional 

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Administrator. If a state chooses not to (or cannot) adopt our 

interpretation, the letter should address whether the state has 

alternative authority to implement the GHG tailoring approach or 

some other approach that is at least as stringent, but which 

also addresses the expected shortfalls in personnel and funding 

and delays in permitting that would exist if the state carried 

out permitting under part 70 program thresholds lower than those 

adopted by EPA in this final rule. For any state that is unable 

or unwilling to adopt the permitting thresholds in the final 

rules, and otherwise is unable to demonstrate adequate personnel 

and funding, EPA will move forward with finalizing a narrowed

limited approval of the state’s existing part 70 program. If we 

do so, then we will respond in that action to comments on our 

proposal. 

In our proposed rule, we also noted that a handful of part

70 operating permit programs may include provisions that would 

not require operating permits for any source of GHG emissions 

because, for example, the programs may apply only to pollutants 

specifically identified in the program provisions, and the 

provisions do not specifically identify GHGs. In these cases, 

states may be unable to interpret their regulatory provisions to 

interpret the term “any pollutant” to include pollutants 

“subject to regulation.” We indicated that we intended to take 

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separate action to identify these programs, and to take 

regulatory action to correct this deficiency. Accordingly, we 

ask any state or local permitting agency that does not believe 

its existing part 70 regulations convey authority to issue title 

V permits to GHG sources consistent with the final rule to 

notify the Regional Administrator by letter as to whether the 

state intends to undertake rulemaking to revise its rules 

consistent with these applicability thresholds. This 

notification should be done no later than the previously 

described letter regarding adoption of the Tailoring Rule, and 

could be combined with similar notifications we request 

regarding the PSD program. We intend to undertake a separate 

regulatory action to address part 70 programs that lack the 

ability to issue operating permits for GHG sources consistent 

with the final rule. We intend use our federal title V 

authority to ensure that GHG sources will be permitted 

consistent with the final rule. 

D. Rationale for Treatment of GHGs for Title V Permit Fees

The title V program requires permitting authorities to 

collect fees “sufficient to cover all reasonable (direct and 

indirect) costs required to develop and administer [title V] 

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programs.” 56 To meet this requirement, permitting authorities 

either collect an amount not less than a minimum amount 

specified in our rules (known as the “presumptive minimum”), or 

may collect a different amount (usually less than the 

presumptive minimum). We did not propose to change the title V 

fee regulations in our notice of proposed rulemaking for this 

action, nor did we propose to require new fee demonstrations 

when title V programs begin to address GHGs. However, we did 

recommend that each state, local or tribal program review its 

resource needs for GHG and determine if the existing fee 

approaches will be adequate. If those approaches will not be 

adequate, we suggested that states should be proactive in 

raising fees to cover the direct and indirect costs of the 

program or develop other alternative approaches to meet the 

shortfall. We are retaining this proposed approach, and are not 

changing our fee regulations as part of this final action 

establishing steps 1 and 2 of the phase-in. However, we are 

offering some additional clarification of our fee approach 

during these steps in response to comments we received on this 

issue. Additional discussion of fees will be included as part 

of subsequent actions establishing step 3 and beyond. 

 56 The fee provisions are set forth in CAA Section 502(b)(3) 

and in our regulations at 40 CFR 70.9 and 71.9 

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A few state commenters suggested that EPA should modify 

part 70 to adopt a presumptive minimum fee (or range for such 

fee) for GHGs, some of whom suggested that current fees may be 

insufficient to cover the costs of their program. It is 

important to clarify that altering the presumptive minimum would 

only affect those states that chose to charge the presumptive 

minimum fee to sources. Most states – including some of the 

commenters asking EPA to raise the presumptive minimum -- 

collect a lower amount that is not based on the presumptive 

minimum, but rather, relies on another fee schedule that it 

developed and EPA approved as adequate to cover costs. 

Therefore, it is useful to first discuss our approach to 

programs that have fee schedules resulting in a different amount 

before discussing our approach to the presumptive minimum. 

Because of the added GHG title V permitting workload 

described elsewhere in this notice, any state that will not, 

under its current fee structure, collect fees adequate to fund 

the permitting of GHG sources must alter its fee structure in 

order to meet the requirement that fees be adequate to cover 

costs. Changes may not be required in every instance; 

circumstances will vary from state to state. For example a 

state may see increases in revenue from newly-covered sources 

(based on emissions of pollutants already subject to fees) that 
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fully cover the state’s increased costs, or a state may be overcollecting fees now and could use the surplus to offset the 

increased costs. Nonetheless, in many cases, we think states 

will need to adjust their fee structures to cover the costs of 

GHG permitting in order to meet the requirements of the Act and 

our regulations. 

For this reason, although we are not calling for new fee 

demonstrations at this time, we plan to closely monitor state 

title V programs during the first two steps of the Tailoring 

Rule to ensure that the added workload from incorporating GHGs 

into the permit program does not result in fee shortfalls that 

imperil operating permit program implementation and enforcement, 

whatever the basis of the states’ fee schedule. As described in 

the proposal, such fee oversight by EPA may involve fee audits 

under the authority of §70.9(b)(5) to ensure that adequate fees 

are collected in the aggregate to cover program costs, with 

emphasis on whether the additional GHG workload is being 

appropriately funded. Also, EPA retains the ability to initiate 

a program revision under §70.4(i)(3) or issue a notice of 

deficiency under the process described in §70.10(b) to address 

fee adequacy issues, which may be uncovered during a fee audit. 

By relying on existing oversight measures, we are ensuring that 

the fee requirements are met with a minimum of disruption to 
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existing programs at a time when they will already be facing 

significant challenges related to GHG permitting. 

Turning to the minority of states that do use the 

presumptive minimum, we did not propose to change the 

presumptive minimum calculation method to account for GHG. 

Currently under the statute and our rules, the presumptive 

minimum is based on a subset of air pollutants (i.e., VOC, NAAQS 

pollutants except for CO, and pollutants regulated under the 

NSPS and MACT standards promulgated under sections 111 and 112 

of the Act, respectively) that does not include GHGs. The 

amount is specified on a per-ton basis and changes with 

inflation (it is currently set at $43.75/ton), but does not 

apply to emissions over 4,000 tpy of a given pollutant from a 

given source. We noted several difficulties in applying the 

presumptive minimum to GHG, including the large amounts of GHG 

emissions relative to other pollutants and the need for better 

data to establish a GHG-specific amount. Noting that GHGs are 

not currently included in the Act’s list of pollutants to which 

the presumptive fee applies, we also invited comment on whether 

we should raise the fee for listed pollutants to cover the added 

cost of GHG permitting. 

A few state commenters asked us to set a presumptive fee 

for GHGs, which we take to mean we should add GHGs to the list 
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of pollutants to which a presumptive fee would apply. However, 

many commenters noted that the current presumptive minimum fee 

is unreasonable for GHGs because GHGs are emitted in greater 

quantities than the pollutants currently subject to presumptive 

fees, which would result in excessive fees. These commenters 

believe that EPA needs to limit the fees that states can charge 

for GHGs. Moreover, one commenter read the statute to prohibit 

us from listing GHGs in the presumptive fee calculation in the 

first place. Several commenters disagreed with the idea of 

instead increasing the presumptive fee for other pollutants to 

cover the cost of regulating GHGs, some of whom believed that 

this would unfairly punish existing sources or would bring in no 

new revenue from sources triggering title V for the first time. 

After considering these comments, we remain disinclined, as 

we were at proposal, to change the presumptive fee calculation 

regulations. While there is some support for changing the 

regulations, the comments confirm the challenges in doing so. 

While we expressly rejected charging the full presumptive cost 

per ton amount for GHG, we also did not propose language to 

establish a different amount just for GHG, to establish whether 

a different tpy cap would apply, or to assess whether GHGs could 

even be added to the list. Thus, many commenters were very 

concerned about whether the full $43.75 or the 4000 tpy cap 
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would apply to GHG if we listed it as a regulated pollutant for 

fee purposes. Furthermore, we noted at proposal, and commenters 

did not disagree, that more data would be needed to establish 

the appropriate basis for the GHG presumptive minimum. We are 

not taking a final position in this notice on whether the 

statute is amenable to including GHG in the presumptive fee 

calculation currently, but these comments illustrate some of the 

difficulties of such an approach. 

At the same time, we are not increasing the presumptive 

minimum for other pollutants already included in the fee 

calculation. We disagree with the commenter who said such an 

approach would bring in no new revenue from newly-subject 

sources. Many of the newly subject sources would emit alreadyincluded pollutants. If new revenue from these pollutants were 

insufficient, and because the Act does not specify how the 

shortfall must be addressed, the amount of any projected 

shortfall could be made up by increasing fees on these 

pollutants. In fact, the projected shortfall could be addressed 

without having to inventory GHG emissions from title V sources, 

since the emissions of already-included pollutants are wellknown. We also note that, although some commenters are 

concerned that failing to assess fees for GHGs directly would be 

unfair, the statute does not provide that the presumptive fee be 

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proportional to each type of pollutant or be proportionally 

allocated to all sources. Rather, the presumptive fee approach 

provides a backstop for states that do not wish to adopt a more 

tailored approach. Nonetheless, we have decided not to increase 

the presumptive fee amounts for other pollutants because we lack 

information about the extent to which shortfalls exist due to 

GHG permitting, and which mix of sources and fees is appropriate 

for addressing any such shortfall in a state. This decision

also provides greater flexibility to states and minimizes 

disruption to existing programs. 

We note that, contrary to the statements of some 

commenters, the CAA provisions allowing for a presumptive fee 

calculation do not override the basic requirement that fees be 

adequate to cover costs. As noted previously, we expect states 

to see a revenue increase from emissions of listed pollutants at 

newly-major sources for GHG, and it is also possible that the 

presumptive minimum may currently be resulting in overcollection of fees in a state. Thus, a state continuing to use 

the presumptive minimum may not have a shortfall. However, if 

states using the presumptive minimum approach do have a revenue 

shortfall due to GHG permitting, the statute requires the 

shortfall to be addressed. The EPA has had, and will continue 

to have, the ability to require states that use the presumptive 

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minimum to increase their fees if the presumptive minimum 

results in a revenue shortfall that imperils operating permit 

program implementation and enforcement. Thus, although we are 

not changing the presumptive minimum in our regulations, we plan 

to follow the same oversight approach for states using the 

presumptive minimum as for those collecting less based on a 

resource demonstration. As described previously, this approach 

may involve fee audits with emphasis on whether the additional 

GHG workload is being appropriately funded, and other 

appropriate follow-up. 

Consistent with our proposal, EPA is not modifying its own 

part 71 fee structure (which closely mirrors the presumptive 

minimum) in order to charge an additional fee for GHG. EPA must 

revise its fee schedule if the schedule does not reflect the 

costs of program administration. We have not determined that 

the existing fee structure will be inadequate to fund the part 

71 programs costs during the first two phases of permitting GHGs 

as set forth in this action. However, we are required to review 

the fee schedule every 2 years, and make changes to the fee 

schedule as necessary to reflect permit program costs. 40 CFR 

71.9(n)(2). Thus we will continue to examine the increases in 

part 71 burden due to GHG permitting, the current revenue 

collection, and the increases in revenue from newly-subject part 

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71 sources, and will adjust the part 71 fee approach 

accordingly. 

Finally, several state and industry commenters asked EPA to 

provide guidance and recommendations for an appropriate GHG fee 

structure. We note that title V grants permitting authorities 

considerable discretion in charging fees to sources for title V 

purposes and does not require or prohibit fees specifically for 

GHGs, provided the states collect fees in the aggregate that are 

sufficient to cover all the direct and indirect program costs. 

In responding to requests for guidance, we do not wish to limit 

state discretion. For example, some commenters suggest that EPA 

prohibit emissions-based fees for GHG or cap the amount that can 

be collected, while others suggest we provide a range of 

acceptable fees. We are concerned that, given the wide variety 

of fee approaches that states now take, providing specific 

guidance may be disruptive, rather than helpful, to states. 

On the other hand, we recognize that it will initially be 

difficult for states to establish an appropriate emissions fee 

for GHG. As noted previously, there are currently limited data 

available for establishing such a fee, and, due to the large 

quantities of GHG emissions, such a fee may only amount to a few 

cents per ton. At the same time, as noted in the proposal, a 

number similar to that used for other pollutants (e.g., the 

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presumptive minimum of $45/ton of GHG) would be inappropriate 

because it would likely result in huge over-collection. Because 

of this challenge, we note that §70.9(b)(3) allows the state to 

charge fees to individual sources on any basis (e.g., emission 

fee, application fee, service-based fees, or others, in any 

combination). While most states use emissions-based fees, there 

is merit to considering all the available fee bases to address 

increased GHG workload, including approaches that do not require 

a GHG emissions inventory for fee purposes. For example, where 

it is possible to estimate a revenue shortfall as a percentage 

of fee revenue, it may be appropriate to simply attach a 

percentage-based surcharge to each source’s fee to match that 

shortfall. Similarly, where the shortfall could be estimated as 

a total dollar amount, a flat surcharge could be added to each 

source’s fee to address the shortfall. 

These suggestions should not be read to indicate that EPA 

prefers any particular approach, or that EPA rejects a cost per 

ton approach. Rather, they illustrate that it is possible to 

address a revenue shortfall without establishing a GHG per-ton 

fee. While the EPA is declining to recommend specific 

approaches in this preamble, we are committed to assisting 

states in implementing the fee requirements for GHG. Therefore, 
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we will work with any state that requests assistance from EPA in 

developing a workable fee approach. 

E. Other Actions and Issues 

1. Permit Streamlining Techniques 

In our proposal, we stated that while we were phasing-in 

permitting requirements, we would make a concerted effort to 

assess and implement streamlining options, tools, and guidance 

to reduce the costs to sources and permitting authorities of GHG 

permitting. We recognized that the development and 

implementation of these techniques should be an integral part of 

our strategy during the phase-in period, and we stated that we 

would undertake as many of these streamlining actions as 

possible as quickly as possible. We discussed several 

streamlining techniques in particular, including (1) defining 

potential to emit (“PTE”) for various source categories, (2) 

establishing emission limits for various source categories that 

constitute presumptive BACT, (3) establishing procedures for use 

of general permits and permits-by-rule, (4) establishing 

procedures for electronic permitting, and (5) establishing 

“lean” techniques for permit process improvements. The first 

three of these approaches have the potential to have the 

greatest impact in reducing the numbers of sources subject to 

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PSD or title V (the definition of PTE) or of reducing permitting 

costs (presumptive BACT and general permits or permits-by-rule). 

In our proposal, we also described the timing for 

development and implementation of these streamlining techniques. 

We explained that each of the first three techniques would 

generally take 3-4 years to develop and implement, and therefore 

would be of limited use in the near-term. This time frame is 

necessary because EPA will first need to collect and analyze 

small source data that we do not currently have – because these 

are sources that EPA has not traditionally regulated -- in 

order to assess which of these techniques are viable or 

effective for such sources. In general, EPA will then need to 

conduct notice-and-comment rulemaking to establish the 

approaches, and that rulemaking will need to address various 

legal and policy aspects of these approaches. After that, the 

permitting authorities will need some time to adopt the 

streamlining techniques as part of their permitting programs. 

We received several comments on streamlining techniques. 

In general, the comments indicate widespread support for our 

pursuit of streamlining approaches, but some commenters were 

concerned that one or more of EPA’s identified streamlining 

options were complex, vague, ineffective, and questionable 

legally. Noting our proposal to phase-in permitting, in part to 

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allow more time to develop streamlining options for smaller 

sources, some commenters suggested that we should delay 

permitting for larger sources for the same reasons. We 

disagree. Such a delay is not justified under our legal basis 

for this rule. While implementation of steps 1 and 2 – which 

will cover larger sources -- will pose implementation 

challenges, and some of the streamlining tools could assist with 

meeting these challenges, we have assessed the burdens 

associated with GHG permitting and have established a phase-in 

schedule that represents a manageable workload, even in the 

absence of streamlining techniques. On the other hand, we do 

agree with these commenters that, absent streamlining, applying 

PSD and title V requirements to the much larger number of small 

sources would lead to absurd results and administrative 

impossibility. The sources for whom the phase-in delays 

applicability are precisely the sources that have the greatest 

need for streamlining measures, and thus the greatest need for a 

deferral while we develop and implement streamlining options. 

In addition, commenters generally echoed many of our 

concerns about why it will take time to put these measures in 

place, and no commenter presented any information to suggest 

that our 3-4 year estimate for the PTE, presumptive BACT, and 

general permit measures was invalid. 

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For these three techniques, we continue to believe that as 

we noted at proposal, we will require collection of significant 

category-specific data for source and emission unit types that 

have heretofore generally not been regulated by the CAA (e.g., 

furnaces, water heaters, etc.), which could take up to 1 year. 

Moreover, commenters had differences of opinion as to whether 

and how we should move forward on these approaches, and some 

raised policy and legal issues that we would likely want to 

explore through a notice and comment process in order to assess 

which of these measures are viable to pursue further.58 Even if 

a rulemaking were done expeditiously, it would likely require 1

year. Finally, unlike lean and electronic permitting, these 

approaches, once finalized by EPA, will likely require 

 58 We do not attempt to address or resolve the various 

opinions about what legal or policy direction we must take 

regarding any of these streamlining options. The proper forum 

for doing that will be in the action(s) where we apply a given 

option. Nonetheless, our response to comments document provides 

additional detail about the options we described and what 

commenters said about our proposed options. In addition, the 

comments themselves can be accessed in the docket for this 

action. 

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additional time of up to 2 years for states to adopt. Thus, it 

is clear that these approaches will not be in place in time to 

ease any burden prior to the planned rulemaking for step 3. 

Some commenters did observe that the fourth and fifth 

techniques, lean and electronic permitting, could, at least 

theoretically, become available sooner. However, these 

commenters also noted that successful design and implementation 

of these approaches will require implementation experience with 

GHG permitting that is not now available. We expect that for 

the lean and electronic permitting techniques, at least 1 year 

of implementation experience (of the type that we will gain 

starting in 2011) would be required, plus at least an additional 

year to extrapolate that experience to small sources and put 

these approaches into effect for small source permitting. Thus, 

we do not think the lean and electronic permitting would be in 

place before the beginning of 2013. Moreover, a handful of 

commenters questioned whether lean and/or electronic permitting 

would alleviate significant burden. Thus we are not able, at 

this time, to presume that these approaches will ease any burden 

prior to the planned rulemaking for step 3. 

 It is also important to note that, as a practical matter, 

while these efforts to streamline the program for small sources 

are underway, EPA and states will also be devoting a significant 

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amount of their permitting resources and expertise to 

implementing the PSD and title V programs for the GHG-emitting 

sources covered under Steps 1 and 2. We have established these 

steps in a manner that they will be feasible for EPA and 

state/local/tribal authorities, but even so, they will not only 

consume current permitting authority resources, but they will 

also require substantial additional resources. As a result, the 

efforts to develop and implement streamlining techniques will 

have to compete with the work necessary to administer existing 

programs. For example, during the remainder of 2010, as 

described elsewhere in this notice, EPA permitting program 

resources will, in addition to continuing to administer programs 

for non-GHG pollutants, be used to conduct at least the 

following GHG-related activities in addition to streamlining: 

(1) develop BACT and other information and guidance for 

implementing programs for sources covered by Step 1, followed by 

additional guidance and information for sources covered by Step 

2; (2) review and act on information we receive regarding state 

adoption of GHG permitting requirements, which may entail 

narrowing of previous SIP approvals or processing of other 

programmatic revisions; and (3) propose and finalize measures to 

address programs with deficiencies in GHG coverage. As the 

beginning of step 2 nears, we will also begin to receive and 

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process the first applications for permits that will incorporate 

GHG requirements (i.e., those that will be issued after January 

2, 2011). States seeking to implement streamlining approaches 

will face similar competition for permitting resources. 

 These time frames and resource considerations for 

streamlining confirm the approach to phase-in that we are taking 

in this rule. First and foremost, they make clear that it will 

not be possible to have streamlining measures in place in time 

for either Step 1 or Step 2. Therefore our selection of 

threshold for those steps is not built on assumptions that 

streamlining will remove some or all of the burden during those 

steps. 

 Second, they make clear that, while no significant 

streamlining can be in place by the time we must begin to 

develop the step 3 rule (i.e., latter half of 2011, to 

promulgate by July 2012, effective July 2013), it is likely that 

by that time EPA and states will have had an opportunity to gain 

implementation experience that could serve as the basis for 

beginning to implement streamlining techniques that do not 

require rulemaking or state adoption (e.g., lean and electronic 

permitting). It is also likely that we will have had an 

opportunity to gather technical information – which we have 

already begun to gather --for certain source and emissions unit 

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categories that would be necessary to support proposal of PTE or 

presumptive BACT approaches for those categories. We expect 

that the step 3 rulemaking will provide an opportunity for us to 

use that experience and data to begin to propose streamlining 

approaches that need notice and comment rulemaking. We can also 

begin to take into account any burden reductions from possible 

early streamlining efforts – that is, through lean and 

electronic permitting -- in the establishment of step 3. 

 Third, it is clear that the potential availability of 

streamlining measures does not call into question our decision 

that in no event will we broaden PSD and title V applicability 

to cover GHG-emitting sources below the 50,000 tpy CO2e level 

prior to July 2016, as discussed elsewhere. EPA cannot now 

predict the resources that will be required to implement PSD and 

title V programs for GHG-emitting sources once various 

streamlining techniques are ultimately completed. This is 

uncertain not only because we need data and implementation 

experience with GHG permitting during steps 1, 2, and 3 that we 

can apply to estimates for small sources, but also because, as 

comments indicate, there is a broad range of legal and policy 

issues to consider in crafting the streamlining approaches we 

ultimately adopt. We have presented an initial assessment of 

options and obtained views of commenters both supporting and 

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opposing them, and it is the result of these future actions, 

whose outcomes are uncertain at this time, that will ultimately 

determine the extent to which streamlining approaches will allow 

for the administration of PSD and title V programs for numerous 

small sources. Thus, while we are optimistic that we can craft 

workable, common-sense solutions, we nonetheless, believe it is 

important to preserve our small source exclusion until we have 

not only had time to put the streamlining approaches in place, 

but also have had time to assess the burdens that remain, before 

we bring in additional sources below the 50,000 tpy levels. We 

believe that the 6-year timeframe will require a sustained 

intensive effort by EPA and states to develop, adopt, and 

implement streamlining techniques, and will require EPA to then 

evaluate those techniques and complete a rulemaking concerning 

PSD and title V applicability to small-sources based on that 

evaluation. In this manner, the 6-year period will give us the 

necessary time to make the best decisions about the actions we 

should take beyond step 3. 

While comments make clear that there are issues to be 

addressed, nothing in the comments has persuaded us that we 

should abandon our streamlining efforts. To the contrary, the 

strong support for these efforts shown by many commenters 

reinforces our intention, as stated at proposal, to move forward 

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with these approaches as an integral part of our phase-in 

approach. Moreover, notwithstanding the competition for GHG 

permitting resources and expertise, we believe it is critical 

that we move forward expeditiously. As noted previously, we are 

already taking a first step by initiating permitting for larger 

sources, beginning January 2011, that will begin to provide 

valuable implementation experience. This experience can be 

useful in allowing states to begin implementing early 

streamlining measures, like lean and electronic permitting, 

which do not require EPA action. We have also already begun, 

and will continue, developing data necessary to support possible 

rulemakings addressing approaches such as PTE, presumptive BACT, 

and/or general permits. We expect to be able to use these data 

to support possible rulemakings on these topics, as appropriate, 

at about the same time as our step 3 rulemaking. There may also 

be available streamlining options that were not described in our 

proposal that warrant further consideration. Because of the 

uncertainty surrounding such approaches, we are not committing 

to finalize rules on any particular approach, but we do plan to 

explore all streamlining options as expeditiously as possible, 

beginning immediately and proceeding throughout the phase-in 

period, and we encourage permitting authorities to do the same. 

We commit to consider a wide array of possible streamlining 

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measures, and we commit to propose and take comment on, in the 

step 3 rulemaking, a set of those measures that we determine are 

viable to pursue further. 

2. Guidance for Best Available Control Technology 

Determinations 

The CAA requires that a PSD permit contain, among other 

things, emissions limits based on the BACT for each pollutant 

subject to regulation under the Act emitted from the source that 

triggers PSD. 42 U.S.C. § 7475(a)(4); 42 U.S.C. § 7479(3). 

BACT is defined as follows: 

(3) The term "best available control technology" 

means an emission limitation based on the maximum 

degree of reduction of each pollutant subject to 

regulation under this Act emitted from or which 

results from any major emitting facility, which 

the permitting authority, on a case-by-case 

basis, taking into account energy, environmental, 

and economic impacts and other costs, determines 

is achievable for such facility through 

application of production processes and available 

methods, systems, and techniques, including fuel 

cleaning, clean fuels, or treatment or innovative 

fuel combustion techniques for control of each 

such pollutant. In no event shall application of 

"best available control technology" result in 

emissions of any pollutants which will exceed the 

emissions allowed by any applicable standard 

established pursuant to section 111 or 112 of 

this Act. Emissions from any source utilizing 

clean fuels, or any other means, to comply with 

this paragraph shall not be allowed to increase 

above levels that would have been required under 

this paragraph as it existed prior to enactment 

of the Clean Air Act Amendments of 1990. 

42 U.S.C. § 7479(3). 

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Thus, the BACT process is designed to determine the most 

effective control strategies achievable in each instance, 

considering energy, environmental, and economic impacts. 

However, the case-by-case nature of BACT, together with the 

range of factors and technologies that must be considered, 

presents a challenge in determining BACT for newly regulated 

pollutants. When a new pollutant is regulated, the first permit 

applicants and permitting authorities that are faced with 

determining BACT for a new pollutant will likely need to invest 

more time and resources in gathering and analyzing information 

necessary to make an assessment of BACT under the statutory 

criteria. Once the PSD permitting program matures with respect 

to the new pollutant, successive BACT analyses will establish 

precedents that can inform subsequent BACT determinations. 

While the BACT provisions clearly contemplate that the 

permitting authority evaluate control strategies on a case-bycase basis, EPA recognizes the need to develop and share policy 

guidance and technical information for sources and permitting 

authorities as they begin to permit sources of newly regulated 

pollutants, such as GHGs. When applied in a practical manner, 

this additional EPA guidance and technical information should 

reduce time and resource needs when evaluating BACT for newly 

regulated pollutants. 

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As described in the proposed GHG Tailoring Rule, EPA 

intends to compile and make available technical and background 

information on GHG emission factors, control technologies and 

measures, and measurement and monitoring methodologies for key 

GHG source categories. We expressed our intent to work closely 

with stakeholders in developing this supporting information and 

to ensure this information is available in sufficient time to 

assist permitting agencies in their BACT determinations. The 

proposal took comment on what other types of support or 

assistance EPA can provide to initially help air pollution 

control agencies with the permitting of GHGs. 

Commenters on the proposed GHG Tailoring Rule generally 

supported EPA providing technical information and policy 

guidance for sources of GHGs. Several commenters specifically 

requested guidance to clarify GHG-related issues, such as how to 

compute CO2e emissions, how to evaluate emissions of CO2 from 

biomass fuel, and whether an air quality analysis will be 

required for GHGs. Additionally, commenters requested that EPA 

issue “white papers” and other tools that would provide 

information on a range of control technologies and measures for 

major stationary source categories, such as power plants, cement 

kilns, glass furnaces, and other sources. Many of these 

commenters further requested that EPA provide an opportunity for 

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stakeholder input on the guidance, and a few commenters insisted 

that permitting for sources of GHGs should not begin prior to 

issuing final guidance. 

Consistent with our commitment at proposal to involve all 

stakeholders in our guidance development, EPA called upon the 

CAAAC in September 2009, to provide assistance and 

recommendations for what types of guidance and technical 

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information would be helpful.59 Specifically, our charge to the 

CAAAC was “... to discuss and identify the major issues and 

potential barriers to implementing the PSD Program under the CAA 

for greenhouse gases ... [and] focus initially on the BACT 

requirement, including information and guidance that would be 

useful for EPA to provide concerning the technical, economic, 

and environmental performance characteristics of potential BACT 

options.” This charge also requested the CAAAC to “identify and 

discuss approaches to enable state and local permitting 

authorities to apply the BACT criteria in a consistent, 

practical and efficient manner.” 

At its October 6, 2009 meeting, the CAAAC established a 

Climate Change Work Group, made up of 35 representatives from a 

variety of industries, state and local governments, and 

environmental and public health non-profit organizations, 

organized under CAAAC’s Permits, New Source Review and Toxics 

Subcommittee. The Work Group initially focused its attention on 

the procedure for evaluating BACT and decided that the process 

 59 The CAAAC is a senior-level policy committee established in 1990 to advise the U.S. 

EPA on issues related to implementing the CAA Amendments of 1990. The committee is 

chartered under the Federal Advisory Committee Act and has been renewed every 2 years 

since its creation. The membership is approximately 40 members and experts 

representing state and local government, environmental and public interest groups, academic 

institutions, unions, trade associations, utilities, industry, and other experts. The CAAAC meets 

3 times a year, normally in Washington, D.C. It provides advice and counsel to EPA on a 

variety of important air quality policy issues. The committee has formed several subcommittees 

to provide more detailed discussion and advice on many technical issues.

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and criteria for determining BACT for criteria pollutants 

represented a workable and acceptable framework for GHGs. The 

Work Group also recommended a second phase, in which the Work 

Group would consider member proposals regarding possible 

alternative or supplementary approaches to applying the PSD 

program to GHG sources. 

In February 2010, the CAAAC completed work on the first 

phase of its effort and sent EPA a list of recommendations that 

highlighted areas of the BACT determination process that are in 

need of technical and policy guidance. For more information, 

see the Interim Phase I Report on Issues related to BACT for 

GHGs, February 3, 2010 that is located in the public docket for 

this rulemaking and at 

http://www.epa.gov/air/caaac/climate/2010_02_InterimPhaseIReport

.pdf. In response we are working on a number of fronts to 

develop technical information, guidance, and training to assist 

states in permitting large stationary sources of GHGs, including 

identifying GHG control measures for different industries. EPA 

is currently working with states on technical information and 

data needs related to BACT determinations for GHGs. This 

includes developing the EPA Office of Research and Development 

GHG Mitigation Strategies Database, enhancing the RACT/BACT/LAER 

Clearinghouse to include GHG-specific fields, and preparing 

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technical information on sector-based GHG control measures. 

Also, EPA is actively developing BACT policy guidance for GHGs 

that will undergo notice and comment and will culminate in 

training courses for state, local and tribal permitting 

authorities. The results of all of these efforts will roll out 

over the remainder of 2010. EPA currently awaits the Work 

Group’s recommendations from its second phase of deliberations, 

which is underway as of the date of this notice. 

EPA does not agree with some commenters’ suggestion that 

EPA should delay permitting any sources until final BACT 

guidance is issued. As discussed in the final action on 

reconsideration of the Interpretive Memo, delaying the 

application of BACT to enable the development of guidance or 

control strategies is not consistent with the BACT requirements. 

63 FR at 17008. Furthermore, as just described, EPA expects 

such a delay to be unnecessary because EPA will soon begin 

providing technical information to inform BACT decisions, and 

will continue to provide additional guidance prior to the date 

that GHG permitting begins. However, even in the absence of 

such guidance, a delay would not be justified under the legal 

doctrines of absurd results and administrative necessity. While 

implementation of the BACT requirement during steps 1 and 2 will 

pose implementation challenges, EPA has assessed the burden 

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associated with GHG permitting with consideration given to these 

challenges, and has established a phase-in schedule that 

represents a manageable workload. 

Thus, while BACT will remain a case-by-case assessment, as 

it always has been under the PSD program, EPA is confident that 

this guidance development effort will help support a smooth 

transition to permitting emissions of GHGs. Furthermore, EPA 

will continue to work to provide the most updated information 

and support tools to allow permitting authorities to share and 

access the most updated information on GHG BACT determinations 

as they are made once permitting of GHGs begins. EPA remains 

committed to involving stakeholders in the upcoming efforts to 

develop guidance to help to permitting authorities in making 

BACT determinations for sources of GHGs. 

3. Requests for Higher Category-Specific Thresholds or 

Exemptions from Applicability 

Although we did not propose any categorical exemptions, 

many commenters requested exemptions from major source and major 

modification applicability determinations under title V and PSD 

for certain types of GHG-emitting sources or certain types of 

GHG emissions as follows: 

Source Categories. Many commenters requested various 

exemptions or exclusions from source applicability for GHGs 

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under both PSD and title V permitting, either during the phasein period or permanently, citing anticipated burdens, societal 

costs, and differences in emission characteristics. Commenters 

representing non-traditional sources or source categories 

(sources that have not historically been required to get 

permits) requested exemptions from permitting based on GHG 

emissions, including agricultural sources, residential sources, 

and small businesses. In general, these commenters sometimes, 

but not always cited “absurd results” and “administrative 

necessity” arguments in their exemption requests. 

Several commenters from sectors that consume a great deal 

of energy in their industrial processes and that are subject to 

international competitiveness, such as aluminum, steel, cement, 

glass, pulp and paper, and other manufacturers, requested that 

they be exempt from permitting under this final rule. These 

commenters opine that we have not carefully considered the 

environmental and economic consequences of this action because 

if we had, we would have exempted them for several reasons, 

including (i) other countries typically exempt similar sources 

from GHG cap and trade programs because the industries are 

making significant energy efficiency improvements even in the 

absence of GHG regulation, and (iii) permitting such sources may 

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cause many facilities to move to countries that have less 

regulation or no regulation for GHGs. 

Other industry groups cited unique characteristics of their 

emissions, or the quantities in which they are emitted, that 

they argued should justify exclusion or unique thresholds. 

Semiconductor production facilities asked for exemptions, 

arguing that combustion-related GHG emissions are different from 

their GHG emissions, which result from the use of high-GWP 

industrial gases, such as PFCs, with higher GWP values that are 

more likely to trigger permitting requirements at relatively low 

tpy values. One lime production commenter stated that EPA could 

encourage energy efficiency projects at their plants by 

excluding calcination and other process emissions, arguing that 

these emissions are a relatively small portion of the national 

inventory that will have no material effect on air quality and 

global warming. Another commenter requested that EPA exclude 

emissions from poultry production (natural bird respiration) 

from permitting consideration because the IPCC excludes them 

from their GHG emission estimates. Representatives of the 

landfill industry pointed to the relationship between current 

statutory thresholds that apply to their regulated emissions, 

primarily NMOC, and the equivalent amount of GHG emissions this 

corresponds to. They argued for a source-category specific 

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threshold that is at least equivalent to their current NMOC 

threshold, or roughly 750,000 tpy CO2e according to their 

estimate. 

Although the proposal for the Tailoring Rule generally 

addressed how the statutory requirements for major source 

applicability (100/250 thresholds) could be phased-in in ways 

that would offer relief to traditional and non-traditional 

sources, such as residences, farms, small business, and 

semiconductor manufacturers, it did so by establishing

relatively high CO2e thresholds during the early implementation 

period and lowering the thresholds over time as streamlining 

mechanisms become available to reduce administrative burdens. 

We did not propose any permanent exemptions of any kind. Also,

note that the proposal discussed energy efficiency, process 

efficiency improvements, recovery and beneficial use of process 

gases, and certain raw material and product changes in the 

context of short-term, low-cost means of achieving GHG emission 

reductions for small-scale stationary sources, but not in the 

context of exemptions. 

As discussed previously, we are still considering whether 

permanent exemptions from the statute are justified for GHG 

permitting based on the “absurd results” legal doctrine. 

However, we do not have sufficient basis to take final action at 

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this time that would promulgate any of the suggested exclusions

on the grounds, described previously, suggested by the 

commenters. We did not propose any sort of permanent exclusion 

based on an interpretation of the statutory provisions of PSD or 

title V. Regardless of any arguments about the legality and 

advisability from a policy or economic standpoint of such 

exclusions, we would need to propose a PSD and/or title V 

specific legal and policy rationale that fits within the CAA, to 

specify details regarding our implementation approach, and to 

provide an opportunity for public comment before adopting any 

such exclusion. Therefore we are not doing so here. We note, 

however, that nothing in this rule forecloses the opportunities 

we may have to explore such options in the future. Therefore, 

we are taking no action in this rule on these various 

commenters’ requests for exclusions.

The remaining option for creating such exclusions in this 

rule is to find that such an exclusion is necessary to avoid 

overwhelming permitting burdens. We did solicit comment on 

alternative approaches to burden relief in the proposed phase-in 

for permitting. Some commenters suggested that the 

administrative necessity or absurd results rationale could be 

used to create at least temporary exclusions that would allow 

more sources to escape permitting than what we proposed We 

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considered each of these requests in the context of the 

overwhelming permitting burdens and the options for reducing 

such burdens, and ultimately decided that, given our thresholdbased approach to the phase-in, it is not appropriate to also 

adopt such exclusions to address the same burdens. We have 

finalized steps 1 and 2 using the threshold-based approach, 

which applies the various legal doctrines, in the context of the 

Chevron framework, in a way that effectively exempts all small 

sources during this part of the phase-in. The suggested 

exclusions alone would not address the overwhelming permitting 

burdens, and the threshold-based approach would still be 

necessary. Moreover, once the threshold approach is applied as 

described, we do not see that the remaining burdens would be so 

overwhelming as to provide a basis under our legal rationale for 

exclusion. While we could have crafted specific exemptions of 

the kind suggested as an alternative means of tailoring the 

programs, our approach achieves the same result and does so in a 

way that will be simpler to administer. In any event, 

commenters did not provide enough specific information about the 

costs and administrative burdens associated with permitting 

their source categories to persuade us to exclude those source 

categories, consistent with our overall rationale. Furthermore, 

specifically with respect to high GWP, gases as discussed 

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previously, are maintaining the statutory mass-based threshold

that addresses commenters’ concerns regarding the inclusion of 

those gases. Therefore, we are not finalizing any such 

exclusions in this rule and, as noted above, we are not taking 

final action in the commenters’ requests for exclusions. 

Concerning the comment that we did not take appropriate 

economic and environmental considerations into account for this 

rulemaking action, we disagree. The approach we finalize in 

this notice for steps 1 and 2 minimizes economic burdens by 

limiting permitting to the largest GHG emission sources. We 

further note that the PSD program as applied to the sources that 

are covered in steps 1 and 2 contains an express requirement to 

take energy, environmental, and economic considerations into 

account when making control technology (i.e., BACT) decisions 

and accordingly many of the concerns about control costs will be 

able to be accounted for in that analysis. 

Biomass Combustion/Biogenic Emissions. Several commenters 

request that EPA exempt emissions from biogenic activities or 

biomass combustion or oxidation activities, including solid 

waste landfills, waste-to-energy projects, fermentation 

processes, combustion of renewable fuels, ethanol manufacturing, 

biodiesel production, and other alternative energy production 

that uses biomass feedstocks (e.g., crops, or trees). For 

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example, commenters urged that EPA exclude emissions from 

biomass combustion in determining the applicability of PSD to 

GHGs based on the notion that such combustion is “carbon 

neutral” (i.e., that combustion or oxidation of such materials 

would cause no net increase in GHG emissions on a lifecycle 

basis). Other commenters oppose the exemption of biogenic 

activities because they opine that carbon neutrality of biomass 

combustion is an incorrect assumption that stems from what they 

call a “critical accounting error” in the Kyoto protocols. 

These commenters oppose the exemption of biogenic/biomass 

activities, citing the lack of a valid scientific basis for 

treating these GHG emissions differently than other GHG 

emissions. 

The proposed Tailoring Rule did not address this issue of 

exemptions for biomass combustion or biogenic emissions. We are 

mindful of the role that biomass or biogenic fuels and 

feedstocks could play in reducing GHGs, and we do not dispute 

the commenters’ observations that state, federal, and 

international rules and policies recognize carbon-neutrality in 

various ways. However, we have determined that we do not have 

sufficient basis to create an exclusion from the permitting 

applicability provisions for biomass combustion or biogenic 

fuels and feedstocks. Such an exclusion alone, while reducing 

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burdens for some sources, would not address the overwhelming 

permitting burdens described previously, and a threshold-based 

approach would still be needed. Once we adopt a threshold-based 

approach, we do not have information regarding the 

administrative burden of permitting projects that specifically 

involve these source types, nor did the commenters provide any 

that demonstrate an overwhelming permitting burden would still 

exist that justifies even a temporary exclusion for biomass 

sources. 

At the same time, we did not propose any sort of permanent 

exclusion based on an interpretation of the statutory provisions 

of PSD or title V. Regardless of any arguments about the 

legality and advisability of such an exclusion, we would need to 

propose a PSD and/or title V specific legal and policy rationale 

and specify details regarding our implementation approach (e.g. 

an approach to carbon accounting), and would need to provide an 

opportunity for public comment before adopting any such 

exclusion. Therefore we are not able to finalize such an 

approach here. We note, however, that we are not taking final 

action on commenters’ request for exclusion, and that nothing in 

this rule forecloses the opportunities we may have to explore 

such options in the future. 

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We further note that, while we are not promulgating an 

applicability exclusion for biogenic emissions and biomass fuels 

or feedstocks, there is flexibility to apply the existing 

regulations and policies regarding BACT in ways that take into 

account their lifecycle effects on GHG concentrations. This 

topic has already been explored by the CAAAC workgroup on BACT 

issues related to GHGs that recently provided recommendations to 

EPA. These recommendations are located in the public docket for 

this rulemaking and at 

http://www.epa.gov/air/caaac/climate/2010_02_InterimPhaseIReport

.pdf. While that group was unable to come to a consensus on how 

biomass-based emissions should be treated, it provided us with 

information that we will consider as we issue guidance on BACT. 

As previously discussed, we plan to issue BACT guidance later 

this year, but are not doing so as part of this rulemaking. 

This issue warrants further exploration in that context, and we 

plan to fully explore it and take action as appropriate. 

Fugitive Emissions. Numerous commenters believe that 

fugitive GHG emissions should be excluded from major source 

determinations, citing difficulties in measuring or estimating 

such emissions. Others believe EPA did not address fugitive 

emissions in the proposal and they ask for clarification of the 

treatment of fugitive GHGs in applicability determinations under 

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PSD and title V. Some of these commenters state that EPA has 

not undertaken a rulemaking under section 302(j) for any source 

category of fugitive GHGs, so they should not be included. 

Several commenters representing the solid waste disposal 

industry requested exemptions for fugitive emissions for 

landfills and waste-to-energy projects, pointing out that 

current practice under PSD is for fugitive emissions from 

certain landfills to not be counted toward major source 

determinations. 

In the proposal, EPA did not offer any specific guidance or 

discuss exemptions for fugitive emissions of GHGs. Commenters 

did not suggest that a fugitive exemption would address the 

overwhelming permitting burdens described previously, or that it 

was necessary to specifically tailor GHG applicability through 

the use of a fugitive emissions exclusion for categories that 

would otherwise be required to include them. We do agree with 

commenters who stated that we should clarify how to count 

fugitives in determining applicability under this rule. In 

response, we note that we are not taking final action with 

respect to commenters’ request, and we are not finalizing any 

special rules for fugitive emissions related to GHG. Thus, 

EPA's rules related to the treatment of fugitives would apply. 

Regarding the comment that a 302(j) rulemaking is required 

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before fugitive emissions may be counted, we disagree. As we 

read 302(j), once EPA has established by rule that fugitive 

emissions are to be counted for a specific source category, 

nothing in section 302(j) requires EPA to conduct new rulemaking 

to allow for the counting of additional pollutants from that 

category. We read 302(j) as imposing an obligation to determine 

if fugitive emission generally should be counted from a source 

or source category and not requiring that EPA list both source 

categories and relevant pollutants. Indeed, our practice in 

listing categories has not been to limit the pollutants to which 

the listing applies. Therefore, we are applying our existing 

rules and policies for fugitive emissions for GHG as we would 

any other pollutant. 

Pollution Control Projects. Other commenters request 

exemptions for pollution control projects from PSD major 

modification requirements, particularly projects that increase 

the efficiency or thermal performance of a unit or facility, 

resulting in emission reductions on a pounds/megawatt-hour or 

production basis. The current PSD rules do not exclude 

pollution control projects from being considered a physical 

change or change in the method of operation that would – if it 

resulted in a significant net emissions increase -- constitute a 

major modification, nor does case law suggest that we could 
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adopt a permanent exclusion in the future60. We also do not 

believe we should adopt an exclusion for pollution control 

projects that relies solely on absurd results or administrative 

necessity for reasons similar to those described previously for 

other requested exclusions. Although such an exclusion may have 

positive features, it would not address the overwhelming 

permitting burdens that justify the tailoring approach. 

4. Transitional Issues including Requests for Grandfathering 

In the Tailoring Rule proposal, we did not discuss or 

specifically ask for comment on any provisions to address the 

transition from a permitting regime that does not incorporate 

greenhouse gases to one that does, such as “grandfathering” 

provisions or similar approaches that would exempt previously 

issued permits or pending applications from having to 

incorporate requirements for greenhouse gases. We nonetheless 

received several public comments that addressed a variety of 

transitional issues. One group of comments addresses situations 

prior to permit issuance where a PSD or title V application is 

 60 On June 24, 2005, the United States Court of Appeals for 

the District of Columbia Circuit vacated the portions of the 

2002 and 1992 NSR rules that pertained to PCP, among other 

provisions. In response to this Court action, on June 5, 2007, 

EPA removed these provisions from the NSR regulations. (See 72 

FR 32526). These provisions were added as part of EPA’s NSR 

improvement rule that was issued on December 31, 2002. 

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either administratively complete or more generally being 

processed prior to the trigger date for GHG permitting (“in 

process” applications). Another group of comments addresses 

situations where a PSD or title V permit is issued prior to the 

GHG trigger date and the commenters request that the application 

and/or permit be exempt from any requirements for updates 

related to GHGs after permit issuance. 

With respect to PSD, many commenters requested that we 

adopt a “grandfathering” approach to applicability to exempt 

projects that have administratively complete PSD or minor NSR 

permit applications pending when the GHG permitting requirements 

go into effect. Several commenters urged us to promulgate 

transition provisions (without specifically using the term 

“grandfathering”), pointing out that we have provided transition 

periods for revising pending PSD permits, in the past, when new 

PSD rules were issued (e.g., in late 1970s and 1980). These 

commenters assert that GHG requirements will cause more 

disruption than those previous rule changes. Several commenters 

asked that PSD applications be evaluated on the basis of the PSD 

requirements effective when the application is submitted and if 

submitted prior to the trigger date, then the application and 

permit would not need to address GHGs. Several commenters also 

asked that PSD sources with a valid permit that commences 

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construction within 18 months of the trigger date not be 

required to seek a revised PSD permit for GHGs. Similarly, 

several commenters asked that PSD permits issued prior to the 

GHG trigger date not be required to be reopened only for the 

purpose of addressing GHG emissions. Additional commenters asked 

that we clarify that sources or projects not be required to 

obtain PSD permits if they obtained a determination that PSD did 

not apply (a “non-applicability” determination) prior to the GHG 

trigger date. Finally, many commenters also requested 

“grandfathering” for title V so that existing title V 

applications and permits do not need to be amended, revised, or 

resubmitted to address GHGs after they become “subject to 

regulation”. Other commenters asked that transition provisions 

for title V be provided in the final action that would be 

similar to those requested for PSD. 

 We partially addressed transitional issues for PSD 

permitting in our April 2, 2010 final action on reconsideration 

of the Interpretive Memo. 75 FR 17021. This action addressed 

the applicability of PSD permitting requirements for greenhouse 

gases to pending PSD permit applications that were (or will be) 

submitted prior to January 2, 2011 based on emissions of 

pollutants other than greenhouse gases. However, we have not 

yet addressed the questions raised by public comments concerning 

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sources that obtain PSD permits, minor NSR permits, or 

determinations that no such permits are needed prior to the step 

1 period set forth in this rule. We have also not yet addressed 

questions about the applicability of PSD permitting requirements 

for sources that are not currently required to submit an 

application for a PSD permit but that could be required to do so 

in step 2 of the phase-in established in this action. In 

addition, our April 2, 2010 action did not address transitional 

issues concerning the application of the title V provisions to 

greenhouse gases. 

a. Transition for PSD Permit Applications Pending When Step 1 

Begins 

In our action on April 2, 2010, EPA explained that the 

Agency did not see grounds to establish a transition provision 

for pending PSD permit applications because we had determined 

that PSD permitting requirements would not apply the greenhouse 

gases for another 9 months. We explained that permit 

applications submitted prior to April 2, 2010 should in most 

cases be issued prior to January 2, 2011 and, thus, effectively 

have a transition period of 9 months to complete processing 

before PSD requirements become applicable to greenhouse gases. 

We also observed that, in the case of any PSD permit application 

review that cannot otherwise be completed within the next 9

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months based on the requirements for pollutants other than GHGs, 

it should be feasible for permitting authorities to begin 

incorporating GHG considerations into permit reviews in parallel 

with the completion of work on other pollutants without adding 

delay to permit processing. Additional discussion of EPA’s 

reasons for not developing transition provisions for PSD permit 

applications that are pending on January 2, 2011 are provided in 

the April 2, 2010 notice. 75 FR 17021-22. 

For these same reasons, we continue to feel that a 

transition period is not warranted to incorporate GHG 

requirements into any PSD permit applications that are pending 

when step 1 of the permitting phase-in begins for those sources 

that would otherwise need to obtain a PSD permit based on 

emissions of pollutants other than greenhouse gases. Thus, this 

action makes no change to the position we expressed on this 

particular issue in the April 2, 2010 notice. In this final 

rule on tailoring the PSD program to address GHGs, we have 

determined that the additional burden of incorporating GHG 

requirements into PSD permits for the sources already required 

to obtain such permits is manageable in the step 1 period. 

Thus, this rule has added no additional requirements or 

limitations that would justify deferring the establishment of 

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pollution controls for this category of GHG sources once PSD 

permitting requirements are initially triggered for GHGs. 

b. PSD Permits Issued Prior to Step 1 

EPA has not historically required PSD permits to be updated 

or reopened after they are issued in the absence of an action by 

the applicant to change the physical or operational 

characteristics of the source described in the permit 

application. EPA’s PSD permitting regulations contain no 

provisions that address the modification or amendment of a PSD 

permit or require a PSD permit to be reopened or modified on the 

basis of new PSD permitting requirements that take effect after 

the final permit is issued. Since PSD permits are construction 

permits, EPA has not required updates to PSD permits in the same 

manner as is typically required for operating permits that 

incorporate a variety of applicable requirements (such as title 

V permits and NDPES permits under the Clean Water Act). In 

addition, unlike operating permits, PSD permits are not required 

to be renewed. However, if construction under a PSD permit is 

not commenced in a timely manner or is discontinued for an 

extended period, a PSD permit may expire if an extension is not 

requested or justified. See, 40 CFR 52.21(r)(2); 40 CFR

124.5(g).

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With respect to the application of PSD permitting 

requirements for GHGs beginning on January 2, 2011, we do not 

see any cause to deviate from our historical practice of not 

requiring PSD permits to be reopened or amended to incorporate 

requirements that take effect after the permit is issued. Thus, 

we are not promulgating any new rules or requirements pertaining 

to PSD permits issued prior to Step 1 of the phase-in described 

in this rule. There is no mandatory requirement to reopen a 

previously issued PSD permit to incorporate GHG requirements 

that were not applicable at the time the permit was issued. 

A major source that obtains a PSD permit prior to January 

2, 2011 will not be required under EPA regulations to reopen or 

revise the PSD permit to address greenhouse gases in order for 

such a source to begin or continue construction authorized under 

the permit. Our current PSD permitting regulations provide that 

“[n]o new major stationary source or major modification to which 

the requirements of paragraphs (j) through (r)(5) of this 

section apply shall begin actual construction without a permit 

that states the major stationary source or major modification 

will meet those requirements.” 40 CFR 51.166(a)(7)(iii); 40 CFR

52.21(a)(2)(iii). The term “begin actual construction” 

generally means “initiation of physical onsite construction 

activities on an emissions unit which are of a permanent nature” 

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and includes activities such as “installation of building 

supports and foundations, laying underground pipework and 

construction of permanent storage structures.” 40 CFR

51.166(b)(11); 40 CFR 52.21(b)(11). A source that begins actual 

construction authorized under a PSD permit prior to January 2, 

2011 will not be in violation of the prohibition described 

previously if it continues construction after that date. This 

portion of the regulation precludes only beginning construction 

without the appropriate preconstruction permit and does not 

require a permit to be updated to continue actual construction 

that has already begun. 

Furthermore, a source that is authorized to construct under 

a PSD permit but has not yet begun actual construction on 

January 2, 2011 may still begin actual construction after that 

date without having to amend the previously-issued PSD permit to 

incorporate GHG requirements. Sections 51.166(a)(7)(iii) and 

52.21(a)(2)(iii) require “a permit that states the major 

stationary source or major modification will meet those 

requirement,” which refers to the “requirements in paragraphs 

(j) through (r)(5)” referenced earlier in those provisions. EPA 

construes this language to describe a permit that meets the 

requirements of paragraph (j) through (r)(5) that are in effect 

at the time the permit is issued. Permitting and licensing 

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decisions of regulatory agencies must generally reflect the law 

in effect at the time the agency makes a final determination on 

a pending application. See Ziffrin v. United States, 318 U.S. 

73, 78 (1943); State of Alabama v. EPA, 557 F.2d 1101, 1110 (5th

Cir. 1977); In re: Dominion Energy Brayton Point, LLC, 12 E.A.D. 

490, 614-616 (EAB 2006); In re Phelps Dodge Corp., 10 E.A.D. 

460, 478 n. 10 (EAB 2002). 

 Thus, a source may begin actual construction on or after 

January 2, 2011 under a PSD permit that authorized construction 

to begin prior to January 2, 2011 because such a permit states 

that the source will meet the requirements of paragraphs (j) 

through (r)(5) of these regulations (or state equivalents) that 

were in effect at the time the permit was issued. However, this 

would not be the case if the permit has expired because the 

applicant has discontinued construction or failed to commence 

construction by the necessary date. See, 40 CFR 52.21(r)(2). 

This approach is consistent with EPA’s practice when the 

preconstruction permitting requirements change by virtue of the 

designation of an area as a nonattainment area after a PSD 

permit is in issued. In transitional guidance issued by EPA in 

1991, EPA explained that “the area designation in effect on the 

date of permit issuance by the reviewing agency determines which 

regulations (part C or D) apply to that permit.” Memorandum 

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from John S. Seitz, Director OAQPS, New Source Review (NSR) 

Program Transitional Guidance, page 6 (Mar. 11, 1991). This 

memorandum explained further that “where a source receives a PSD 

or other permit prior to the date the area is designated as 

nonattainment, the permit remains in effect” as long as the 

sources meets the conditions necessary to prevent the permit 

from expiring. Id. at 6. 

 This approach does not apply if the source engages in a 

major modification after January 2, 2011 that is not authorized 

by the previously issued permit. Once step 1 of the phase-in 

begins, if the PSD requirements for GHGs are applicable to a 

previously-permitted source that engages in a major modification 

not covered by the permit, such a source will need obtain a new 

PSD permit to authorize the modification and that permit may 

need to include GHG requirements depending on the level of 

increase in GHGs that results from the modification. 

c. Additional Sources for Which PSD Applies in Step 2 

In light of the terms of existing PSD regulations and the 

lead time provided in this action for sources that will first 

become subject to PSD permitting in Step 2, we do not believe 

there is presently a need to establish transition provisions for 

sources that will be required to obtain PSD permits for the 

first time in Step 2 of the phase-in. As described previously, 

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under our current PSD permitting regulations, a new major 

stationary source or major modification may not begin actual 

construction without a PSD permit that meets the applicable 

preconstruction permitting requirements. 40 CFR

51.166(a)(7)(iii); 40 CFR 52.21(a)(2)(iii). 

Since a permit must be obtained before a major source may 

begin actual construction, the major source preconstruction 

permitting requirements in sections 51.166 and 52.21 of the 

regulation do not generally apply to sources that begins actual 

construction at a time when it was not a major source required 

to obtain a PSD permit. One exception, however, is the unique 

circumstance when a source becomes a major source solely by 

virtue of the relaxation of an enforceable limitation on the 

source’s potential to emit. 40 CFR 51.166(r)(2); 40 CFR

52.21(r)(4). But absent these circumstances, PSD 

preconstruction permitting requirements do not generally 

preclude a source from continuing actual construction that began 

before the source was a source required to obtain a PSD permit. 

Thus, a source that began actual construction under the 

authorization of any previously required minor source or state 

construction permit is not required to meet any PSD 

preconstruction permitting requirement that becomes applicable 

after actual construction begins unless the source engages in a 

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major modification after PSD permitting requirements are 

applicable. Likewise, a PSD permit is not required after a 

source begins actual construction based on a valid determination 

(by the source or the permitting authority) that the source need 

not obtain either a major PSD permitting requirements or and 

minor NSR permit. Based on these provisions in existing 

regulations, EPA will not require any sources to which PSD 

permitting requirements begin to apply in step 2 to obtain a PSD 

permit to continue construction that actually begins before step 

2 begins. 

However, we will expect Phase 2 sources that begin actual 

construction in phase 2 (i.e., beginning July 1, 2011) to do so 

only after obtaining a PSD permit in accordance with sections 

52.21, 51.166, or any applicable state regulation that meets the 

requirements of section 51.166. We recognize the potential for 

the triggering of step 2 to result in a change in status where a 

project may legally have begun actual construction before step 2 

but did not do so and would then need a PSD permit. However we 

also note that we are providing over a year of lead time before 

PSD permitting requirements become applicable to step 2 sources. 

If projects would be adversely affected by this change in 

status, this lead time affords an opportunity for sources 

planning such projects to secure appropriate minor NSR permits 

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(which generally take less than a year to issue), nonapplicability determinations, etc. in time to avoid such a 

change in status. If a new or modified source that would become 

newly subject to PSD in step 2 plans to begin actual 

construction before step 2, it has more than a year to obtain 

the applicable preconstruction approvals and begin actual 

construction. Likewise, a step 2 source that does not 

anticipate the ability to begin actual construction before step 

2 begins should have enough lead time to submit a PSD permit 

application and obtain the necessary permit without 

significantly delaying the project further. Therefore, we do 

not think it is necessary or appropriate to promulgate a 

transition provision that would exempt step 2 sources from PSD 

permitting requirements that will apply based on construction 

that begins after step 2 takes effect. 

This approach for Step 2 sources that have obtained a minor 

source construction permit or non-applicability determination 

differs from the approach described previously for source that 

obtained a PSD permit prior to Step 1. As described previously, 

a Step 1 source that is authorized to begin actual construction 

before January 2, 2011 under a previously-issued PSD permit may 

begin actual construction under that permit after January 2, 

2011 without modifying the PSD permit to address GHGs. However, 

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a Step 2 source that was not required to obtain a PSD permit 

before Step 2 begins would need to obtain a PSD permit 

addressing GHGs if it has not yet begun actual construction 

prior to Step 2, even if the source had obtained any 

preconstruction approvals that were necessary to authorize 

construction prior to Step 2. This is because such a Step 2 

source that begins actual construction after Step 2 would likely 

be doing so without having any permit meeting the requirements 

of paragraphs (j) through (r)(5) of section 52.21, 51.166, or a 

state equivalent. A source that has obtained only a minor 

source permit prior to Step 2 but that begins actual 

construction after July 1, 2011 would violate the requirements 

of section 52.21(a)(2)(iii), 51.166(a)(7)(iii), or a state 

equivalent, unless the source took care to ensure that it was 

authorized to construct under a PSD permit or could demonstrate 

that the source’s minor source construction permit makes clear 

that requirement of paragraphs (j) through (r)(5) of sections 

52.21, 51.166, or a state equivalent would be met by the source 

even though such a permit was not nominally a PSD permit. This 

difference in approach for non-PSD sources is driven by the 

terms of sections 52.21(a)(2)(iii) and 51.166(a)(7)(iii). Since 

we have not provided any prior notice that we might be 

considering revisions to sections 52.21 and 51.166 to address 

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this topic, we are unable to revise the regulations in this 

action to achieve the same result for non-PSD sources as for PSD 

sources. Furthermore, this difference in approach is not 

unreasonable since non-PSD sources will not trigger permitting 

for GHG until step 2 (only anyway PSD source trigger in step 1). 

Thus sources will have until July 1, 2010, an additional 6 

months of lead time, to prepare for the transition described 

here. 

EPA has previously promulgated exemptions that have 

authorized some sources that were not previously subject to the 

PSD regulations to commence construction on the basis of minor 

source permits after the date new PSD requirements have took 

effect in 1978 and 1980. See e.g., 40 CFR 52.21(i)(1)(iv)-(v). 

There is a notable distinction between these provisions, which 

use the term “commence construction,” and the terms of sections 

52.21(a)(2)(iii) and 51.166(a)(7)(iii), which use the term 

“begin actual construction.” Commerce construction is defined 

more broadly than begin actual construction to include obtaining 

all necessarily preconstruction approvals and either beginning 

actual on-site construction or entering into binding contracts 

to undertake a program of actual construction. 40 CFR

52.21(b)(9); 40 CFR 51.166(b)(9). The term commence 

construction is also defined in the CAA. 42 USC 7479(2)(A). 

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Among other purposes, the term “commence construction” is 

generally used in the Act and EPA regulations to distinguish 

construction activities that are exempt from new PSD permitting 

requirements from those that are not. See e.g., 42 USC 7475(a); 

40 CFR 52.21(i)(1)(i)-(v). In the absence an explicit exemption 

in the CAA or the PSD regulations that uses the term “commence 

construction,” we do not believe we can use the date a source 

“commences construction” under a minor source construction 

permit approval as a demarcation point for Step 2 sources that 

may continue ongoing construction activities without having to 

obtain a PSD permit based on emissions of GHGs. Since we did 

not provide prior notice of an intention to adopt transition 

provisions applicable to this situation, we are unable to adopt 

such an exemption in this action that applies the term commence 

construction in this context. Consequently, the approach 

described previously applies the term “begin actual 

construction” based on the language in sections 52.21(a)(2)(iii) 

and 51.166(a)(7)(iii). 

d. Transitional Issues for Title V Permitting 

Since the title V permitting regulations already include a 

robust set of provisions to address the incorporation of new 

applicable requirements and other transitional considerations, 

we do not see grounds to establish unique transition or 

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grandfathering provisions for GHGs in this action. Furthermore, 

since the purpose of title V is to collect all regulatory 

requirements applicable to a source and ensure compliance, we do 

not believe special exemptions for GHG requirements are likely 

to be justified. The existing title V rules do not provide any 

exemptions that relieve the obligation to incorporate all 

applicable requirements into a title V permit. However, the 

title V regulations contain numerous provisions that allow a 

reasonable period of time for incorporating new applicable 

requirements or applying for a title V permit that was not 

previously required. Transitional issues for incorporation of 

GHG requirements into title V permitting generally involve 

questions in the following categories: (1) permit application 

requirements for sources not previously subject to title V that 

will become subject to title V requirements in step 2 of the 

phase-in; (2) the need for updates or amendments to title V 

permit applications that are pending when GHGs become subject to 

regulation in Step 1 of the phase-in; and (3) the incorporation 

of new applicable requirements for GHGs into existing permits 

for sources currently subject to title V. 

With respect to the first category, a title V source 

applying for the first time must submit its permit application 

within 12 months after the source “becomes subject to the 

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[operating] permit program” or such earlier time that the 

permitting authority may require (see §70.5(a)(1)). Sources not 

otherwise subject to title V can become major sources subject to 

title V due to emissions of GHG no sooner than July 1, 2011. If 

a source becomes “subject to the [operating] permit program” on 

July 1, 2011, then its permit application under the title V 

operating permit program would typically have to be submitted no 

later than July 1, 2012. 

There are also existing regulations relevant for the second 

category of GHG transition issues, where sources currently 

subject to title V have title V permit applications pending with 

a permitting authority as of January 2, 2011. Where additional 

applicable requirements become applicable to a source after it 

submits its application, but prior to release of a draft permit, 

the source is obligated to supplement its permit application. 

See 40 CFR 70.5(b); 71.5(b). Furthermore, title V permits are 

generally required to contain provisions to assure compliance 

with all applicable requirements at the time of permit issuance. 

See CAA section 504(a); 40 CFR 70.6(a)(1); 71.6(a)(1). If a 

permitting authority determines that additional information is 

necessary to evaluate or take final action on an application 

(e.g., because of uncertainty over whether a draft permit 

assures compliance with all applicable requirements), it may, 

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and should, request additional information from the source in 

writing and set a reasonable deadline for a response. See 40 

CFR 70.5(a)(2); 71.5(a)(2). 

Likewise, the existing title V regulations provide 

sufficient transition for the third category of issues, where a 

source has additional GHG-related applicable requirements (such 

as the terms of a PSD permit) that must be incorporated into its 

existing title V permit. Where a source is required to obtain a 

PSD permit, the source must apply for a title V permit or permit 

revision within 12 months of commencing operation or on or 

before such earlier date as the permitting authority may 

establish (or prior to commencing operation if an existing title 

V permit would prohibit the construction or change in 

operation). See 40 CFR 70.5(a)(1)(ii); 71.5(a)(1)(ii); see 

also §§70.7(d) and (e); 71.7(d) and (e) (permit modifications). 

In addition, where a source becomes subject to additional 

applicable requirements, the permitting authority is required to 

reopen the permit to add those applicable requirements if the 

permit term has three or more years remaining and the applicable 

requirements will be in effect prior to the date the permit is 

due to expire. See 40 CFR 70.7(f)(1)(i); 71.7(f)(1)(i). 

Finally, EPA notes that the existing title V regulations 

require sources to furnish permitting authorities, within a 

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reasonable time, any information the permitting authority may 

request in writing to determine whether cause exists for 

modifying, revoking, and reissuing, or terminating the permit, 

and for other reasons, and further provide that permitting 

authorities shall reopen and revise permits if EPA or the 

permitting authority determine that the permit must be revised 

or revoked to assure compliance with applicable requirements. 

See §§70.6(a)(6)(v);71.6(a)(6)(v) and §§ 70.7(f)(1)(iv); 

71.7(f)(1)(iv). 

Thus, EPA believes that the existing title V regulations 

provide an adequate regulatory framework for managing the 

transition to incorporating GHG requirements in title V permits 

and additional specific exemptions or transition rules for title 

V are not currently warranted. 

VI. What are the economic impacts of the final rule? 

This section of the preamble examines the economic impacts 

of the final rule including the expected benefits and costs for 

affected sources and permitting authorities. The final rule 

uses a phased-in approach for requiring sources of GHG emissions 

to comply with title V operating permit and PSD statutory 

requirements, essentially lifting this burden for a period of at 

least 6 years for a large number of smaller sources of GHG. 

Thus, this rule provides regulatory relief rather than 

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regulatory requirements for these smaller GHG sources. For 

larger sources of GHG that will be required to obtain title V 

permits and/or comply on PSD requirements, there are no direct 

economic burdens or costs as a result of this final rule, 

because these requirements are not imposed as a result of this 

rulemaking. Statutory requirements to obtain a title V 

operating permit or to adhere to PSD requirements are already 

mandated by the CAA and by existing rules, not by this rule. 

Similarly, this rule will impose costs to society in the form of 

foregone environmental benefits resulting from GHG emission 

reductions that, absent this rule, might otherwise have occurred 

at sources deferred from permitting during the phase-in period. 

The regulatory impact analysis (RIA) conducted for this 

final rule provides details of the benefits or regulatory relief 

that smaller GHG sources will experience in terms of costs 

avoided as a result of this final rule and the potential for 

social costs in terms of foregone environmental benefits during 

this 6-year period. Complete details of the RIA conducted for 

this final rule may be found in the document "Regulatory Impact 

Analysis for the Final Greenhouse Gas Tailoring Rule," in the 

docket for this rulemaking. 

This rulemaking provides permitting thresholds for sources 

of GHG that exceed levels contained in the CAA and these levels 

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are phased in steps based upon application of the administrative 

necessity and absurd results doctrines as explained in section 

V.B. For step 1 that is effective from January 2, 2011 through 

June 30, 2011, only sources required to undergo title V or PSD 

permitting based upon non-GHG air pollutants are required to 

obtain an operating permit or PSD permit to include GHG 

emissions. Step 2, effective from July 1, 2011 until such time 

as EPA acts on a rule to amend it (which for reasons described 

previously, we assume is June 30, 2013 for the purposes of this 

analysis), requires larger sources emitting GHG above 100,000 

CO2e tpy to obtain a title V permit (if they do not already have 

one) and to comply with PSD requirements when they are newly 

constructed or modify in a way that increases emissions by more 

than a 75,000 CO2e tpy significance level. Thereafter, EPA makes 

an enforceable commitment to consider a possible step 3 to 

further lower thresholds below 100,000 CO2e tpy and/or 

permanently exclude some sources from the program(s), but only 

after a regulatory process is conducted addressing 

administrative necessity and absurd results considerations based 

upon the actual permitting experiences in the first two steps of 

the phase-in. In addition, EPA provides a deferral of 

permitting until we take required action in April 2016 for 

sources and modifications that emit below 50,000 CO2e tpy. The 

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deferral will end when a required study is conducted of the 

permitting process for sources of GHG and EPA acts, based on the 

study, to promulgate a rule that describes the additional GHG 

permitting requirements beyond 2016. In the 6 years following 

promulgation of this rule, the EPA estimates that compared to 

baseline estimates that do not include the effects of this rule, 

over six million sources of GHG emissions in total will be 

allowed to continue to operate without a title V operating 

permit. During this period, tens of thousands of new sources or 

modifying sources each year will not be subject to PSD 

requirements for GHG. For this large number of smaller sources, 

this rule alleviates the regulatory burden associated with 

obtaining an operating or PSD permit or complying with NSR BACT 

requirements. Therefore, this final action may be considered 

beneficial to these small sources because it provides relief 

from regulation that would otherwise be required. 

This decision does potentially have environmental 

consequences in the form of higher emissions during the 6-year 

period of time (generally because emissions increases would have 

been lower if BACT were applied). These consequences are 

limited due to the fact that sources between 100/250 and 100,000 

CO2e tpy account for an estimated 11 percent of the six directly 

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residential source categories, while representing over 95 

percent of the total number of sources potentially requiring an 

operating or PSD permit for GHG under current permitting 

thresholds in the CAA. Moreover, requiring such a large number 

of small sources to obtain permits for the first time would 

overtax the permitting authorities' abilities to process new 

permits and would therefore interfere with any such benefits 

actually being achieved. Moreover, reductions from these small 

sources will still be occurring, notwithstanding the fact that 

permitting requirements would not apply to them. These smaller 

sources of GHG will be the focus of voluntary emission reduction 

programs and energy efficiency measures that lead to reductions 

in GHG. We will also reevaluate this decision after a 6-year 

period and complete a study of the implications for those 

sources and permitting authorities of permitting smaller GHG 

sources beyond 2016. 

In reaching the preceding decisions for this final rule, we 

carefully considered comments received on the Tailoring Rule

proposal. We received several comments specifically on our 

description of the impacts of this rule. Most of these comments 

disagreed with our assertion that the rule is a “relief” rule. 

Others assert that we should have prepared a more comprehensive 

RIA than prepared for the rule proposal. Those commenting 

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contend: (1) we understated the burdens of the rule while 

overstating its relief at proposal; (2) we erroneously omitted 

the impacts for “larger sources” of GHG from the proposal RIA 

and should have recognized the burden to “larger sources” due to 

other GHG actions; (3) the economic impacts the rule will have 

on industry and the United States economy society in general 

will be burdensome, especially given the current state of the 

economy; and (4) we need to propose a full RIA or a complete 

estimation of impacts to comply with CAA section 307(d) and the 

APA. 

 EPA has carefully considered the comments addressing the 

issue of whether the Tailoring Rule is a regulatory “relief 

rule”, and we are not persuaded that we erred in concluding that 

the effect of the Tailoring Rule is to provide regulatory relief 

to a large number of sources of GHG for a period of up to 6

years. This final rule will provide relief from title V 

permitting to over 6 million sources of GHG in this country. 

Likewise tens of thousands of sources potentially subject to PSD 

permitting requirements annually for GHG will have regulation 

postponed for a period of up to 6 years under this rule, 

followed by an additional required rule addressing the period 

beyond 6 years. While larger sources of GHG may be required to 

obtain title V permits or modify existing permits and to comply 

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with PSD requirements, these burdens result not from the 

Tailoring Rule but rather from the CAA requirement to apply PSD 

to each pollutant subject to regulation, which is triggered when 

the LDVR takes effect. To clearly illustrate this, consider 

what would occur if EPA did not complete the Tailoring Rule. 

Sources would not be relieved of the requirement to obtain 

permits addressing each pollutant subject to regulation when 

they construct or modify, nor would they be relieved of their 

obligation to obtain title V permits. Instead, these 

requirements would simply apply to a much larger population of 

sources and modifications, and would lead to the absurd results 

and severe impairment to program implementation that this rule 

is designed to address. 

In response to comments asserting that the RIA completed 

for proposal of this rulemaking: (1) understated the burdens of 

the rule and overstated the benefits, (2) did not fully 

recognize the rule will be burdensome, especially given the 

current state of the economy; and (3) does not consider a 

complete estimation of impacts to comply with the Administrative 

Procedure Act and CAA section 307(d) and needs to correct flawed 

or erroneous assumptions, EPA did make improvements and 

modifications to the RIA completed for this final rule. Based 

upon comments, EPA modified estimates of the number of sources 

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affected at various threshold levels upward. EPA also improved 

the burden estimates associated with obtaining permits for 

sources and permitting authorities. After consideration of the 

burden imposed by the proposed rule with these improved 

estimates for affected sources, the EPA modified the steps of 

the phase-in period to include two initial steps, described in 

section V, that are higher, and therefore cover fewer sources 

and are less burdensome than the proposal threshold of 25,000 

CO2e tpy emissions. EPA also increased the threshold below which 

permitting would not apply for 6 years from 25,000 to 50,000 tpy 

CO2e. After the initial two step period, EPA has committed to 

consider lower thresholds but only down to 50,000 tpy CO2e, and 

only after a regulatory process that uses information gathered 

on actual permitting activity during the first two steps of the 

phase-in period. The RIA conducted for the final rule also 

incorporates improvements in our estimates of the number of 

sources affected at alternative thresholds and improved 

estimates of the costs of obtaining permits by sources and 

processing permits by permitting authorities. The EPA 

acknowledges that the regulatory relief associated with the 

control costs due to BACT requirements for PSD new and modifying 

sources is not included in the RIA for the final rule due to the 

lack of sufficient data about the nature of those requirements. 

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However, it is the case that, as it relates to burden, those 

estimates would simply increase the amount of regulatory relief 

associated with this final rule. 

Finally, with regard to comments that the RIA should have 

been a more comprehensive analysis to include the larger sources 

of GHG that will be required to obtain permits when GHG are 

regulated, the EPA maintains as previously explained that there 

are no direct economic burdens or costs as a result of this rule 

for these sources. Requirements for larger GHG sources to 

obtain title V or PSD permits are already mandated by the Act 

and by existing rules and are not imposed as a result of the 

Tailoring Rule. Thus the economic impacts for larger sources of 

GHG do not occur because of this Tailoring Rule. To include 

these larger sources in the RIA would actually be an inaccurate 

assessment of how this rule affects sources and would ignore the 

fact that this rule is regulatory relief. 

A. What entities are affected by this final rule?

As previously stated, this final rule does not itself 

result in the application of permitting requirements to any 

industrial, commercial, or residential entities. Entities 

affected by this rule are those who experience regulatory relief 

due to the higher thresholds and deferred applicability set 

forth in this rule. This action increases the threshold to 

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obtain a title V and PSD permitting from statutory CAA levels 

using a phased-in step process as previously discussed. As table 

VI-1 shows, this action lifts permitting requirements for over 

six million potential title V sources in total and tens of 

thousands of potential PSD new sources annually that would be 

otherwise required by the CAA to obtain permits. Under step 1, 

over six million title V sources in total and approximately 20 

thousand new PSD sources per year will not be required to obtain 

permits. Under step 2, requiring sources over a 100,000 tpy CO2e 

to obtain a permit, over six million title V sources in total 

and approximately 19.9 thousand new PSD sources per year will 

obtain regulatory relief. While the threshold approach differs 

for steps 1 and 2 of the phase-in plan, the estimated number of 

sources affected does not differ greatly as shown in Table VI-1. 

Sectors experiencing this regulatory relief include electricity, 

industrial, energy, waste treatment, agriculture, commercial and 

residential.

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Table VI-1. Estimated Number of Affected Sources Experiencing 

Regulatory Relief1,2

Number of Sources Experiencing Regulatory 

Relief 

Non-GHG Based <100,000 tpy

Sector Title V New PSD Title V New PSD 

Electricity 285 93 285 33 

Industrial 170,910 604 170,654 599 

Energy 2,588 48 2,536 44 

Waste Treatment 3,358 2 3,165 1 

Agriculture 37,351 299 37,351 299 

Commercial 1,355,921 12,041 1,355,870 12,039 

Residential 4,535,500 6,915 4,535,500 6,915 

Totals 6,105,913 20,002 6,105,361 19,930 

% Emissions Covered3 13% 11% 

Notes: (1) Number of sources is determined on a potential to 

emit basis. Estimates for title V are the total number of 

sources expected to experience regulatory relief. PSD sources 

are annual estimates of newly constructed facilities and do not 

include modifications at existing facilities that may also be 

subject to PSD requirements. (2) See Appendices to ‘Regulatory 

Impact Analysis of the Final Greenhouse Gas Tailoring Rule’ for 

more details of how thresholds and sources affected are 

developed. (3) Percentage of emissions covered represent 

estimated actual emissions from sources expected to experience 

regulatory relief as a percentage of total stationary source GHG 

emissions. 

B. What are the estimated annual benefits to sources due to 

regulatory relief from the statutory requirements?

EPA estimated the annual benefits (avoided costs) to 

sources of GHG emissions and permitting authorities anticipated 

from this final rule. In addition, an accounting of the 

benefits from this action as measured by avoided permit 

processing costs for state, local, and tribal permitting 

authorities is provided. These benefits or avoided costs relate 

specifically to information collection costs or burden costs 

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postponed for smaller sources of GHG emissions otherwise 

required to obtain an operating permit under title V or required 

to modify an existing permit to address GHG emissions. Avoided 

costs shown also include information collection requirements for 

additional PSD permits postponed for new or modifying smaller 

sources of GHG, as well as the avoided costs to state, local and 

tribal permitting authorities. These estimates do not consider 

avoided emission control costs associated with PSD requirements 

for potential BACT requirements. Estimates for BACT are 

unavailable at this time because of the difficulty predicting 

the results of the BACT process as it would be applied to new 

pollutants and classes of sources for which there is no previous 

BACT experience on which to rely. 

1. What are annual estimated benefits or avoided burden costs 

for title V permits? 

Table VI-2 shows that the estimated annual title V benefits 

to sources and to permitting authorities in terms of avoided 

information collection cost resulting from this final action to 

be approximately $70,524.3 million under step 1 of the phase-in, 

the non-GHG based requirements threshold. These avoided costs 

become $70,517.1 million annually under step 2 of the phase-in 

where permitting is required for sources at or above the 100,000 

tpy CO2e threshold. Under the non-GHG based phase-in step 1, 

approximately $49,457.3 million in regulatory relief will accrue 
444

to sources and approximately $21,067 million to permitting 

authorities annually in the form of avoided permit processing 

costs. With the <100,000 tpy CO2e threshold for phase-in step 2, 

these annual regulatory relief benefits are expected to be quite 

similar at $49,455.4 million for sources of GHG emissions and 

$21,061.7 million for permitting authorities. Industrial 

sources permitting costs are estimated to be $46.4 thousand per 

permit for a new permit and $1.7 thousand for a permit revision. 

The EPA estimates that over tens of thousands of industrial 

sources per year will avoid incurring these permitting costs 

under steps 1 and 2 of the phase-in period. The cost for a 

permit for new commercial and residential sources is estimated 

to be $23.2 thousand per permit with approximately 2 million of 

these permits avoided annually. 

State, local, and tribal permitting authorities will also 

benefit in terms of avoided permitting administrative costs of 

over $21 billion as a result of the decisions final in this 

action. For industrial sources, the cost for permitting 

authorities to process a new industrial title V 

permit is approximately $19.7 thousand per permit and $1.8 

thousand for a permit revision. Similar permitting authority 

avoided permit processing costs are approximately $9.8 thousand 

per permit for a new commercial or residential title V permit. 

All estimates are stated in 2007 dollars. 

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Title V Regulatory Relief 

for Sources and Permitting 

Authorities1, 2 ¶

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permitting regulatory 

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Table VI-2. Annual Title V Regulatory Relief for Sources and Permitting Authorities1, 

Step One 

Non-GHG Based

Step Two 

<100,000 tpy CO2e

Activity 

Cost per 

Permit 

(2007$) 

Number of 

Permits 

Avoided Costs 

(millions 

2007$) 

Number of 

Permits 

Avoided Costs 

(millions 

2007$) 

SourcesNew Industrial $46,350 71,829 $3,329.3 71,829 $3,329.New Commercial/Residential $23,175 1,985,948 $46,024.3 1,985,930 $46,023.Permit revisions due to GHG $1,677 61,836 $103.7 60,921 $102.Source Total 2,119,613 $49,457.3 2,118,508 $49,455.Permitting AuthorityNew Industrial $19,678 71,829 $1,413.5 71,829 $1,410.New Commercial/Residential $9,839 1,985,948 $19,539.7 1,985,930 $19,539.Permit revisions due to GHG $1,840 61,836 $113.8 60,921 $112.Permitting Authority Total 2,119,613 $21,067.0 2,118,508 $21,061.Total Title V Regulatory Relief $70,524.3 $70,517.

Notes: (1) Annual title V avoided costs estimates represent information collection costfor one third of the total number of title V sources obtaining regulatory relief shown iTable VI-1 potentially requiring permits or permit revisions for GHG. (2) More details on these estimated regulatory relief benefits are available in the Appendices to the “Regulatory Impact Analysis for the Final Greenhouse Gas Tailoring Rule”. 
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2. What are annual benefits or avoided costs associated with 

NSR permitting regulatory relief? 

Table VI-3 summarizes the estimated annual information 

collection costs avoided by sources and permitting authorities 

for PSD permitting due to this Tailoring Rule. The benefits 

associated with avoided cost of compliance for BACT for these 

sources is not included in these estimates due to a lack of 

available data. The estimated avoided burden or reporting and 

recordkeeping cost that would occur absent this rule for new 

industrial sources to obtain permits is estimated to be $84.5 

thousand for a modifying PSD industrial source and $59.2 

thousand for a modifying commercial or multi-family residential 

source. New PSD sources will also be required to obtain a title 

V permit increasing these costs to $130.9 thousand per permit 

for new industrial sources and to $82.3 thousand per permit for 

new commercial or multi-family residential sources. (Note the 

title V costs for these new PSD sources have been included in 

title V estimates shown in Table VI-2.) New and modifying 

sources avoid approximately $5.5 billion annually in PSD 

permitting costs with this rule under the phase-in step 1, nonGHG based threshold. Under the phase-in step 2, <100,000 CO2e

tpy threshold and <75,000 tpy CO2e significance level, this 

avoided PSD permitting cost estimate becomes $5.4 billion 

annually. State, local, and tribal permitting authorities are 
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expected to avoid about $1.51 billion annually in administrative 

expenditures associated with postponing PSD program requirements 

for these GHG sources under step 1 and $1.49 billion under step 

2. All estimates are shown in 2007 dollars. 
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Table VI-3. Annual PSD Regulatory Relief for Sources and Permitting Authorities1,2

Step One

Non-GHG Based

Step Two

<100,000 tpy 

Threshold, <75,000 Significance Level

Activity

Cost 

per 

Permit 

(2007$)

Number 

of 

Permits

Avoided 

Costs 

(millions 

2007$)

Number 

of 

Permits

Avoided 

Costs 

(millions 

2007$)

SourcesNew Industrial $84,530 26,089 $2,205.3 25174 $2,128.0New Commercial/Residential $59,152 55,509 $3,283.5 55505 $3,283.2Source Total 81,598 $5,488.8 80679 $5,411.2Permitting AuthorityNew Industrial $23,243 26,089 $606.4 25174 $585.1New Commercial/Residential $16,216 55,509 $900.1 55505 $900.1Permitting Authority Total 81,598 $1,506.5 80679 $1,485.2Total Title V Regulatory Relief $6,995.3 $6,896.4

Notes: (1) All estimates are based upon potential to emit. Regulatory relief shown represents annual estimates of PSD permitting costs avoided under steps 1 and 2 of the phase-in period. (2) More details on these estimated regulatory relief benefits are available in the Appendices to the “Regulatory Impact Analysis for the Final Greenhouse Gas Tailoring Rule”.
C. What are the economic impacts of this rulemaking?

This final rulemaking does not impose economic burdens or 

costs on any sources or permitting authorities, but should be 

viewed as regulatory relief for smaller GHG emission sources and 

for permitting authorities. Although sources above the 

thresholds set in this rule will become subject to permitting on 

January 2, 2011, those impacts are not attributable to the 

present rulemaking. Rather they are mandated by the CAA and 

existing regulations and automatically take effect independent 

of this action. 

In addition to considering the regulatory relief expected 

for affected entities as a result of this final rule, the EPA 

considered the impact of this rulemaking to small entities 

(small businesses, governments and non-profit organizations) as 

required by RFA and SBREFA. For informational purposes, the RIA 

includes the Small Business Administration (SBA) definition of 

small entities by industry categories for stationary sources of 

GHG and potential regulatory relief from title V and NSR 

permitting programs for small sources of GHG. Since this rule 

does not impose regulatory requirements but rather lessens the 

regulatory burden of the CAA requirements to smaller sources of 

GHG, no economic costs are imposed upon small sources of GHG as 

a result of this final rule. Rather this action provides 

regulatory relief for small sources. These avoided costs or 

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benefits accrue because small sources of GHG are not required to 

obtain a title V permit and new or modifying small sources of 

GHG are not required to meet PSD requirements. Some of the 

small sources benefitting from this action are small entities, 

and these entities will benefit from the regulatory relief 

finalized by this rule. For discussion of comments received and 

EPA responses regarding small entities impacts, see section 

VIII. of this preamble. 

D. What are the costs of the final rule for society?

EPA examined the social costs of this final rule. These 

social costs represent the foregone environmental benefits that 

will occur as a result of the regulatory relief offered to 

sources of GHG emissions. This action is one of regulatory 

relief since it increases the emissions thresholds for the title 

V and PSD programs, as they apply to sources of GHG emissions, 

to levels above those in the CAA. In this preamble section, the 

benefits or avoided regulatory costs of such relief are 

discussed, but there is also a social cost imposed by such 

relief, because this rule may forego some of the possible 

benefits associated with title V and PSD programs for sources of 

GHG emissions below the permitting thresholds established. 

These benefits are those attributed to title V and PSD 

permitting programs in general. These benefits are based upon 

the relevance of these programs to policymaking, transparency 

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issues, and market efficiency, and therefore are very difficult 

to quantify and monetize. For title V, they include the 

benefits of improved compliance with CAA requirements that stem 

from (1) improved clarity regarding applicability of 

requirements, (2) discovery and required correction of 

noncompliance prior to receiving a permit, (3) improving 

monitoring, recordkeeping, and reporting concerning compliance 

status, (4) self-certification of compliance with applicable 

requirements initially and annually, and prompt reporting of 

deviations from permit requirements, (5) enhanced opportunity 

for the public to understand and monitor sources’ compliance 

obligations, and (6) improved ability of EPA, permitting 

authorities, and the public to enforce CAA requirements. 

However, it is important to remember that a title V permit does 

not add new requirements for pollution control itself, but 

rather collects all of a facility’s applicable requirements 

under the CAA in one permit. Therefore, the compliance benefits 

above are less when title V permits contains few or no CAA 

applicable requirements. During the initial steps of the phasein plan established under this action, we expect that the vast 

majority of sources excluded from title V would be sources that 

have no CAA applicable requirements for GHG emissions and few or 

no requirements for other pollutants because their emissions of 

those pollutants are so small. For this reason while it is 
extremely difficult to measure the degree of improved 

compliance, if any, that would be foregone, or to quantify the 

social costs that would be imposed, we expect that they would be 

negligible. 

 For PSD, the primary social cost imposed by the Tailoring 

Rule stems from the foregone benefit of applying BACT to the 

tens of thousands of small new sources and modifications that 

will be below our final thresholds during the first steps of the 

phase-in. This social cost potentially weighs against the cost 

savings described previously that stem (in part) from avoiding 

the administrative and control costs of applying BACT to these 

sources. The BACT requirement assures that new and modified 

sources, when they increase their emissions are using state-ofthe-art emission controls and affords the public an opportunity 

to comment on the control decision. It does not prohibit 

increases but it assures that such controls are applied. 

Delaying the BACT requirement for numerous small sources during 

the first steps of the phase-in for this final rule could allow 

increases from these smaller sources that are greater than they 

would be if BACT were applied. A detailed analysis of this 

difference is beyond the scope of this rule, because we do not 

have detailed information on the universe of these tens of 

thousands of small PSD actions, the candidate BACT technologies 

for each of them, how permitting authorities would make the BACT 

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decisions, and how the BACT limit would compare to what would 

otherwise be installed absent BACT. 

It is not possible at this time to quantify the social 

costs of avoided BACT. However we note that the universe of 

possible emissions that would be regulated by sources excluded 

under the Tailoring Rule is small compared to those that would 

remain subject to PSD. The sources excluded in these first two 

steps of the phase-in plan of this action comprise only 11 

percent of total stationary source GHG emissions, while 67 

percent remain subject to regulation. Furthermore, we expect 

the emissions differences due to BACT controls for such sources 

to be relatively small due to the lack of available capture and 

control technologies for GHG at such sources that are akin to 

those that exist for conventional pollutants and sources, as 

well as the likelihood that even in the absence of BACT such 

sources would already be installing relatively efficient GHG 

technologies to save on fuel costs. Thus, while potential 

benefits would be foregone by excluding smaller sources from the 

permitting programs, these benefits are likely to be small. 

Under the Tailoring Rule, we will be working during the 6-year 

period to greatly improve our understanding of both the 

administrative costs of regulating and the social costs of not 

regulating smaller sources under PSD and title V, and we will be 

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relying on that information to support our future threshold 

analyses called for under the action. 

In reaching the decisions for this GHG Tailoring Rule, the 

EPA recognizes that GHG emissions can remain in the atmosphere 

for decades to centuries, meaning that their concentrations 

become well-mixed throughout the global atmosphere regardless of 

emission origin, and their effects on climate are long lasting 

and significant. A detailed explanation of climate change and 

its impact on health, society, and the environment is included 

in EPA's technical support document for the endangerment finding 

action (Docket ID No. EPA-HQ-OAR-2009-0171). The EPA recognizes 

the importance of reducing climate change emissions for all 

sources of GHG emissions including those sources afforded 

regulatory relief in this rule and plans to address potential 

emission reductions from these small sources using voluntary and 

energy efficiency approaches. Elsewhere, we have discussed 

EPA's interest in continuing to use regulatory and/or nonregulatory tools for reducing emissions from smaller GHG sources 

because we believe that these tools will likely result in more 

efficient and cost-effective regulation than would case-by-case 

permitting. 

VII. Comments on Statutory and Executive Orders Reviews 

In this section, we provide responses to comments we 

received for various Executive Orders (EOs). 

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A. Comments on Executive Order 12866 - Regulatory Planning and 

Review

At proposal, EPA prepared an analysis of the potential 

costs and benefits associated with EPA’s Tailoring Rule proposal 

in an RIA. Several commenters state that EPA’s failure to 

estimate the full costs of the effects of its interpretation of 

PSD applicability in the proposed Tailoring Rule violates EO 

12866. Some of these commenters maintain that EO 12866 directs 

EPA to submit to the Office of Management and Budget (OMB) new 

significant regulations under consideration by the EPA. These 

commenters assert that, in the section 202 rule, EPA failed to 

analyze the effect on stationary sources in the cost benefit 

analysis and there is no indication that EPA included these 

impacts in its submission to OMB. According to the commenters, 

in EPA’s proposal for this rulemaking, EPA has similarly failed 

to analyze the costs and benefits of triggering PSD for 

stationary sources. The commenters assert that without this key 

information, OMB could not fully review the impacts of the 

proposed rule. The commenters believe that EPA’s failure to 

account for known costs that will occur as a direct result of 

the promulgation of the proposed rule in conjunction with the 

section 202 rule violates several applicable requirements of EO 

12866, including sections 6(B)(ii) and 6(C)(iii), which require 

assessments of the potential costs and benefits of the 

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regulatory action and “reasonably feasible alternatives to the 

planned regulation, identified by the Agencies or the public . . 

.” thereby violating both the APA and CAA section 307(d) because 

they deprive businesses and permitting authorities alike of a 

meaningful opportunity to comment on the rule. 

 The EPA has prepared a revised RIA assessing the benefits 

and costs of the final Tailoring Rule to support this rulemaking 

in accordance with EO 12866 as was done with the proposal for 

this rulemaking. Similarly the RIA completed for this action is 

subject to review by an Inter-agency review panel that includes 

the President’s Office of Management and Budget as was the case 

with the proposal RIA. Further, the RIA completed for this 

final rule fully assesses the known benefits and costs 

associated with the Tailoring Rulemaking. This final rule is 

one of regulatory relief from statutory requirements in which a 

large number of sources of GHGs will be relieved of the burden 

of title V and PSD permitting for a period of at least 6 years. 

This final rule will provide relief from title V permitting to 

over 6 million sources of GHG in this country. Likewise tens of 

thousands of sources potentially subject to PSD permitting 

requirements for GHGs will have regulation postponed for a 

period of at least 6 years. While larger sources of GHG may 

still be required to obtain title V permits or modify existing 

permits and to comply with PSD requirements, these burdens 

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result from existing statutory requirements, not from this final 

Tailoring Rule. 

B. Comments on Paperwork Reduction Act

At proposal, we stated in the preamble that we did not 

believe that the proposal would impose any new information 

collection burden. We concluded that the proposed action would 

reduce costs incurred by sources and permitting authorities 

relative to the costs that would be incurred if EPA did not 

revise the rule and provided estimates of those reduced costs. 

Further, we stated that, despite our estimated burden 

reductions, it was unnecessary for us to submit a new 

information collection request (ICR) to the OMB because the ICR 

contained in the existing regulations for PSD (see, e.g., 40 CFR 

52.21) and title V (see 40 CFR parts 70 and 71) had already been 

approved under the provisions of the Paperwork Reduction Act, 44 

U.S.C. 3501 et seq. and has assigned OMB control number 2060–

0003 and OMB control number 2060–0336, respectively. 

However, several commenters disagree that it was 

unnecessary for us to submit a new ICR for the proposed action. 

These commenters believe that (1) prior approval of an ICR for 

the PSD and title V programs ignores the fact that there would 

be an increase in the paperwork burden as a result of applying 

PSD and title V permitting requirements; and (2) unless EPA 

resubmits the information collection approval request to OMB 

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with a proper and fully-inclusive analysis, EPA will lack 

authority to collect information from stationary sources for PSD 

and title V GHG emissions permitting. 

As we stated in the proposal, this is a burden relief rule 

and as such it does not impose any new requirements for the NSR 

or title V programs that are not currently required. For that 

reason, we concluded that for purposes of this rule it was 

unnecessary for us to submit a new ICR to the OMB and that the 

ICR contained in the existing regulations for PSD (see, e.g., 40 

CFR 52.21) and title V (see 40 CFR parts 70 and 71) that had 

already been approved under the provisions of the Paperwork 

Reduction Act, 44 U.S.C. 3501 et seq. and was assigned OMB 

control number 2060–0003 and OMB control number 2060–0336, 

respectively, still applies. 

Nevertheless, we understand that once GHGs are regulated 

under the PSD and title V programs, there will be an increase in 

the paperwork burden and EPA will have to access this possible 

burden. We plan to do so once the 3 year review period of the 

current ICR expires, which will be in early 2011. 

C. Comments on Regulatory Flexibility Act

At proposal, EPA certified that the proposed rule would not 

have a significant impact on a substantial number of small 

entities and therefore we are not obligated to convene a formal 

Small Business Advocacy Review (SBAR) panel. This certification 

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was based upon the fact that the proposed action would relieve 

the regulatory burden associated with the major PSD and title V 

operating permits programs for new or modified major sources 

that emit GHGs, including small businesses. Nevertheless, EPA 

was aware at proposal that many small entities would be 

interested in the various GHG rulemakings currently under 

development and might have concerns about the potential impacts 

of the statutory imposition of PSD requirements that may occur 

as a result of the group of EPA actions, notwithstanding the 

relief provided to small businesses by the Tailoring Rule. For 

these reasons, and in collaboration with the SBA, EPA conducted 

an outreach meeting designed to exchange information with small 

entities that may be interested in these regulations. The 

outreach effort was organized and led by representatives from 

EPA’s Office of Air Quality Planning and Standards within the 

Office of Air and Radiation, EPA’s Office of Policy Economics 

and Innovation, the Office of Information and Regulatory Affairs 

within OMB, and the Office of Advocacy of the Small Business 

Administration. This meeting was conducted on November 17, 2009 

in Arlington, VA, and documentation of this meeting, which 

includes a summary of the advice and recommendations received 

from the small entity representatives identified for the 

purposes of this process, can be obtained in the docket for this 

rulemaking. (See Docket No. EPA-HQ-OAR-2009-0517-19130). 

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During the comment period, several commenters alleged that 

EPA inappropriately limited its RIA and Regulatory Flexibility 

Act/SBREFA analysis, and that had we done a comprehensive 

analysis, we would not have been able to certify that any of the 

proposed rules will not have a significant economic impact on a 

“substantial number of small entities.” Thus they conclude that 

EPA failed to prepare and publicize an initial regulatory 

flexibility analysis (IRFA). Additional commenters stated that 

EPA’s failure to conduct an IRFA to assess the full costs of the 

effects of its interpretation of PSD applicability in the 

Proposed Tailoring Rule violates a host of statutes and 

Executive Orders requiring analysis and public review of 

regulatory burdens. These commenters conclude that EPA should 

have convened one or more SBAR Panels. 

 We are not persuaded that we should have taken into account 

effects beyond those caused by the Tailoring Rule when we made 

our certification of no significant economic impact on a 

substantial number of small entities for this rule. No 

permitting requirements are imposed by this final Tailoring 

Rule. Instead, this final Tailoring Rule offers regulatory 

relief to over an estimated six million sources of GHG emissions 

that would otherwise be required to obtain a title V permit and 

tens of thousands of sources of GHG emissions subject to PSD 

permitting requirements that would otherwise be required 

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statutorily to obtain permit. The RFA does not require that an 

agency complete a regulatory flexibility analysis or conduct an 

SBAR panel where the rule does not have any negative impact on 

small entities. For more discussion of RFA issues, please see 

the RTC document. 

The EPA completed an RIA to assess the economic benefits of 

regulatory relief and the environmental benefits afforded by 

this final rule. The EPA believes that the RIA completed for 

this final rule adequately addresses economic issues associated 

with this Tailoring Rule. 

D. Comments on Unfunded Mandates Reform Act

At proposal, EPA asserted that the Tailoring Rule does not 

impose unfunded mandates on any entities including sources and 

permitting authorities. Since the proposed Tailoring Rule is 

one of regulatory relief, it alleviates the burden of adhering 

to statutorily required permitting thresholds and does not 

impose regulatory requirements. 

Some commenters on the proposed rule assert that EPA has 

failed to comply with the requirements of the Unfunded Mandates 

Reform Act *URMA), pursuant to which EPA must assess the effects 

of the Proposed Rule on state, local, and tribal governments and 

the private sector. Specifically, these commenters state that 

section 202 of the UMRA requires EPA to prepare a written 

statement, including a cost-benefit analysis, for proposed rules 

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with “federal mandates” that may result in expenditures to 

state, local, and tribal governments, in the aggregate, or to 

the private sector, of $100 million or more in any 1 year. 

According to the commenters, in concluding that “the revisions 

would ultimately reduce the PSD and title V program 

administrative burden that would otherwise occur in the absence 

of this rulemaking,” EPA did not account for the billions of 

dollars that permitting authorities and stationary sources will 

soon be required to spend once PSD is triggered for GHGs. 

Additionally, a few commenters contend that the EPA 

underestimated the impacts to public utilities which are 

owned/operated by local governments and also to state regulatory 

agencies. 

The EPA has carefully considered the comments on unfunded 

mandates expressed by commenters to the proposed rule. The EPA 

did complete a RIA for the final rule assessing the benefits and 

costs of the Tailoring Rule, including any unfunded mandates. As 

previously discussed, the Tailoring Rule is one of regulatory 

relief because it increases the GHG emissions threshold for NSR 

and title V permitting substantially above otherwise statutory 

requirements. As such, the EPA has determined that this 

Tailoring Rule does not impose unfunded mandates on any 

entities. This RIA of the final rule incorporates the extensive 

changes made in this final rule, including increased threshold 

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levels for title V and PSD above those contained in the proposed 

rule. While we also incorporated improved estimates of the 

costs for sources to obtain permits and for permitting 

authorities to process permits, they do not change our 

conclusion that this final rule does not impose unfunded 

mandates on any entities. 

E. Comments on Executive Order 13132 – Federalism

Some comments received on the proposed rule assert that 

federalism concerns were ignored, in violation of Executive 

Order No. 13132. According to the commenters, EPA cannot 

maintain that the Tailoring Rule "will not have a substantial 

direct effect on the states, on the relationship between the 

national government and the states, or on the distribution of 

power and responsibilities between various levels of 

government," such that Executive Order No. 13132 does not apply. 

Some of these commenters assert that the proposed rulemaking 

would require radical changes in state laws, interjects GHGs 

into permit programs never once conceived for that purpose (any 

more than was EPA's), requires massive staff hiring at state 

agencies, and rewrites SIPs in place for years or even decades. 

As we stated previously, this is a burden relief rule and 

as such it does not impose any requirements for the NSR or title 

V programs that are not currently required. In addition, this 

action does not interject GHGs into the permit programs, nor 

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does it change state laws or SIPs to impose any new permitting 

requirements. Instead, this action will significantly reduce 

the burden and costs incurred by sources and permitting 

authorities relative to the burden and costs that would be 

incurred if EPA did not revise the permitting provisions to 

account for higher applicability thresholds for GHG emissions. 

However, since this rule finalizes burden reducing 

thresholds that will not otherwise apply to the PSD and title V 

programs, we are aware that a few states will have to amend 

their SIPs to incorporate these new thresholds. These states 

will be the ones whose permitting authorities do not implement 

the Federal PSD and title V rules by reference in their SIPs and 

who cannot adopt the higher thresholds by interpretation. 

F. Comments on Executive Order 13175 - Consultation and 

Coordination with Indian Tribal Governments

The National Tribal Air Association (NTAA) supports EPA’s 

proposed rule but requests that tribal air grant funding be 

increased to reflect the air quality-related needs of tribes 

across the nation, and to allow these tribes the opportunity to 

implement the CAA’s PSD and title V programs. The NTAA states 

that, not only are Tribes eligible for section 103 grant funding 

to conduct air quality monitoring, emissions inventories, and 

other studies and assessments, but they may also obtain section 

105 grant funding to implement CAA regulatory programs. 

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According to the NTAA, Tribes are facing many of the same airrelated issues that neighboring state and local jurisdictions 

are facing, but are significantly underfunded to address such 

issues. 

 The Agency is aware and concerned about the resource needs 

for the Tribal air program and we are working to see how grant 

funding might be increased in the future. Nevertheless and for 

the purpose of the permitting programs, we want to clarify that 

tribes that develop Tribal Implementation Plans (TIPs) can 

charge for permits and Tribes with delegation can develop permit 

fee programs under their authority (e.g., Navajo’s permit fee 

program for their delegated title V permit program)to fund both 

the NSR and title V programs. For these reasons, there are a 

number of ways we would like to work with tribes to address the 

funding concern, including encouraging delegation of permitting 

programs and having model codes available for Tribes that want 

to do TIPs for NSR and title V permitting. 

G. Comments on Executive Order 13211 - Actions That 

Significantly Affect Energy Supply, Distribution, or Use

Other commenters assert that EPA’s analysis under Executive 

Order 13211 is insufficient because it addresses only smaller 

sources. These commenters contend that EPA has not meaningfully 

examined the energy implications of its proposed actions and 

interpretations of the CAA. The commenters disagree with EPA’s 

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conclusion that the imposition of costly PSD obligations on 

power plants would have no impact on power supply, distribution, 

or use, when those plants will have had no time to prepare for 

compliance and no idea what BACT may be for GHG emissions. 

Other commenters opine that the adoption of BACT for some 

industries newly-subject to PSD permitting requirements for GHGs 

could involve fuel-switching, and increased energy costs (due to 

the need for a source to convert from coal to natural gas to 

meet BACT). 

Again, this action is a burden relief rule and as such it 

does not create any new requirements for sources in the energy 

supply, distribution, or use sectors. For the purpose of the 

BACT determinations for GHGs, the long-standing top-down BACT 

selection process still applies. Under the CAA and EPA’s 

implementing regulations, BACT is still an emission limitation 

based on the maximum degree of emission reduction achievable 

through application of production processes and available 

methods, systems, and techniques that considers energy, 

environmental, and economic impacts. In other words, BACT 

determinations for GHGs will still have to consider energy, 

environmental and economic feasibility for the various control 

technologies under consideration before selecting a particular 

technology as BACT for a specific source. For that reason, what 

BACT may be for GHG emissions will vary by source, and the 

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technology that is ultimately selected has to be one that is 

feasible based on the current energy, environmental and economic 

impacts that the planned technology might have. Thus, we do not 

believe that this action is likely to have a significant adverse 

effect on the supply, distribution, or use of energy. 

VIII. Statutory and Executive Orders Reviews 

A. Executive Order 12866 - Regulatory Planning and Review

Under EO 12866 (58 FR 51735, October 4, 1993), this action 

is a "significant regulatory action" because it raises novel 

legal or policy issues. Accordingly, EPA submitted this action 

to OMB for review under EO 12866 and any changes made in 

response to OMB recommendations have been documented in the 

docket for this action. 

In addition, EPA prepared an analysis of the potential 

costs and benefits associated with this action. This analysis 

is contained in the RIA for this final rule. A copy of the 

analysis is available in the docket for this action and the 

analysis is briefly summarized in section VIII of this preamble. 

B. Paperwork Reduction Act

 This action does not impose any new information collection 

burden. Instead, this action will significantly reduce costs 

incurred by sources and permitting authorities relative to the 

costs that would be incurred if EPA did not revise the rule. 

Based on our revised GHG threshold data analysis, we estimate 

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that over 80,000 new and modified facilities per year would be 

subject to PSD review based on applying a GHG emissions 

threshold of 100/250 tpy using a CO2e metric. This is compared 

to 280 PSD permits currently issued per year, which is an 

increase of more than 280-fold. Similarly, for title V, we 

estimate that over six million new sources would be affected at 

the 100-tpy threshold for GHGs using the CO2e metric. By 

increasing the volume of permits by over 400 times, the 

administrative burden would be unmanageable without this rule. 

 However, OMB has previously approved the information 

collection requirements contained in the existing regulations 

for PSD (see, e.g., 40 CFR 52.21) and title V (see 40 CFR parts 

70 and 71) under the provisions of the Paperwork Reduction Act, 

44 U.S.C. 3501 et seq. and has assigned OMB control number 2060-

0003 and OMB control number 2060-0336. The OMB control numbers 

for EPA’s regulations in 40 CFR are listed in 40 CFR part 9. 

C. Regulatory Flexibility Act

The Regulatory Flexibility Act (RFA) generally requires an 

agency to prepare a regulatory flexibility analysis of any rule 

subject to notice and comment rulemaking requirements under the 

APA or any other statute unless the agency certifies that the 

rule will not have a significant economic impact on a 

substantial number of small entities. Small entities include 

small businesses, small organizations, and small governmental 

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Procedures Act (

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jurisdictions. 

For purposes of assessing the impacts of this final action 

on small entities, small entity is defined as: (1) a small 

business that is a small industrial entity as defined in the 

U.S. SBA size standards (see 13 CFR 121.201); (2) a small 

governmental jurisdiction that is a government of a city, 

county, town, school district, or special district with a 

population of less than 50,000; or (3) a small organization that 

is any not-for-profit enterprise that is independently owned and 

operated and is not dominant in its field. 

After considering the economic impacts of this final rule 

on small entities, I certify that this final action will not 

have a significant economic impact on a substantial number of 

small entities. In determining whether a rule has a significant 

economic impact on a substantial number of small entities, the 

impact of concern is any significant adverse economic impact on 

small entities, since the primary purpose of the regulatory 

flexibility analyses is to identify and address regulatory 

alternatives “which minimize any significant economic impact of 

the rule on small entities.” 5 USC 603 and 604. Thus, an 

agency may certify that a rule will not have a significant 

economic impact on a substantial number of small entities if the 

rule relieves regulatory burden, or otherwise has a positive 

economic effect on all of the small entities subject to the 

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Administration (

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rule. 

We have therefore concluded that this final rule will 

relieve the regulatory burden for most affected small entities 

associated with the major PSD and title V operating permits 

programs for new or modified major sources that emit GHGs, 

including small businesses. This is because this rule raises 

the major source applicability thresholds for these programs for 

the sources that emit GHGs. As a result, the program changes 

provided in this rule are not expected to result in a 

significant economic impact on a substantial number of small 

entities. 

D. Unfunded Mandates Reform Act

This rule does not contain a federal mandate that may 

result in expenditures of $100 million or more for state, local, 

and tribal governments, in the aggregate, or the private sector 

in any 1 year. Only those few states whose permitting 

authorities do not implement the federal PSD and title V rules 

by reference in their SIPs will have a small increase in burden. 

These states will have to amend their corresponding SIPs to 

incorporate the new applicability thresholds, since the burden 

reducing thresholds that we are finalizing with this rule will 

not otherwise apply to the PSD and title V programs. Thus, this 

rule is not subject to the requirements of sections 202 or 205 

of UMRA. 

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 This rule is also not subject to the requirements of 

section 203 of UMRA because it contains no regulatory 

requirements that might significantly or uniquely affect small 

governments. As discussed earlier, this rule is expected to 

result in cost savings and an administrative burden reduction 

for all permitting authorities and permittees, including small 

governments. 

E. Executive Order 13132 – Federalism

This action does not have federalism implications. It will 

not have substantial direct effects on the states, on the 

relationship between the national government and the states, or 

on the distribution of power and responsibilities among the 

various levels of government, as specified in Executive Order 

13132. These final amendments will ultimately simplify and 

reduce the burden on state and local agencies associated with 

implementing the PSD and title V operating permits programs, by 

providing that a source whose GHG emissions are below the 

proposed levels will not have to obtain a PSD permit or title V 

permit. Thus, Executive Order 13132 does not apply to this 

action. 

In the spirit of Executive Order 13132, and consistent with 

EPA policy to promote communications between EPA and state and 

local governments, EPA specifically solicited comment on the 

proposed rule from state and local officials. 

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F. Executive Order 13175 - Consultation and Coordination with

Indian Tribal Governments

Subject to the Executive Order 13175 (65 FR 67249, November 

9, 2000) EPA may not issue a regulation that has tribal 

implications, that imposes substantial direct compliance costs, 

and that is not required by statute, unless the federal 

government provides the funds necessary to pay the direct 

compliance costs incurred by tribal governments, or EPA consults 

with tribal officials early in the process of developing the 

proposed regulation and develops a tribal summary impact 

statement. 

EPA has concluded that this action may have tribal 

implications. However, it will neither impose substantial 

direct compliance costs on tribal governments, nor preempt 

Tribal law. There are no tribal authorities currently issuing 

major NSR permits; therefore, it will not currently impose 

direct compliance costs on tribal governments. 

EPA consulted with tribal officials early in the process of 

developing this regulation to allow them to have meaningful and 

timely input into its development by publishing an ANPR that 

included PSD GHG tailoring options for regulating GHGs under the 

CAA. (73 FR 44354, July 30, 2008) As a result of the ANPR, EPA 

received several comments from tribal officials on differing PSD 

GHG tailoring options presented in the ANPR which were 

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considered in the proposal and this final rule. Additionally, 

we also specifically solicited comment from tribal officials on 

the proposed rule (74 FR 55292, October 27, 2009). 

As required by section 7(a) of Executive Order 13175, EPA’s 

Tribal Consultation Official has certified that the requirements 

of the Executive Order have been met in a meaningful and timely 

manner. A copy of the certification is included in the docket 

for this action. 

G. Executive Order 13045 - Protection of Children from 

Environmental Health and Safety Risks

EPA interprets EO 13045 (62 FR 19885, April 23, 1997) 

as applying only to those regulatory actions that concern 

health or safety risks, such that the analysis required 

under section 5-501 of the EO has the potential to 

influence the regulation. This action is not subject to EO 

13045 because it does not establish an environmental 

standard intended to mitigate health or safety risks. 

H. Executive Order 13211 - Actions That Significantly Affect 

Energy Supply, Distribution, or Use

This action is not a “significant energy action” as defined 

in Executive Order 13211(66 FR 28355 (May 22, 2001)), because it 

is not likely to have a significant adverse effect on the 

supply, distribution, or use of energy. Further, we have 

concluded that this rule is not likely to have any adverse 

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energy effects because this action would not create any new 

requirements for sources in the energy supply, distribution, or 

use sectors. 

I. National Technology Transfer and Advancement Act

Section 12(d) of the National Technology Transfer and 

Advancement Act of 1995 ("NTTAA"), Public Law No. 104-113, 12(d) 

(15 U.S.C. 272 note) directs EPA to use voluntary consensus 

standards in its regulatory activities unless to do so would be 

inconsistent with applicable law or otherwise impractical. 

Voluntary consensus standards are technical standards (e.g., 

materials specifications, test methods, sampling procedures, and 

business practices) that are developed or adopted by voluntary 

consensus standards bodies. The NTTAA directs EPA to provide 

Congress, through OMB, explanations when the Agency decides not 

to use available and applicable voluntary consensus standards. 

This action does not involve technical standards. 

Therefore, EPA did not consider the use of any voluntary 

consensus standards. 

J. Executive Order 12898 – Federal Actions to Address 

Environmental Justice in Minority Populations and Low-Income 

Populations

 Executive Order 12898 (59 FR 7629 (Feb. 16, 1994))

establishes federal executive policy on environmental justice. 

Its main provision directs federal agencies, to the greatest 

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extent practicable and permitted by law, to make environmental 

justice part of their mission by identifying and addressing, as 

appropriate, disproportionately high and adverse human health or 

environmental effects of their programs, policies, and 

activities on minority populations and low-income populations in 

the United States. 

 EPA has determined that this final rule will not have 

disproportionately high and adverse human health or 

environmental effects on minority or low-income populations 

because it increases the level of environmental protection for 

all affected populations without having any disproportionately 

high and adverse human health or environmental effects on any 

population, including any minority or low-income population. Any 

impact that this final rule will have will be global in nature 

and will increase the level of protection provided to all human 

health and the environment. 

K. Congressional Review Act

The Congressional Review Act, 5 U.S.C. 801 et seq., as 

added by the Small Business Regulatory Enforcement Fairness Act 

of 1996, generally provides that before a rule may take effect, 

the agency promulgating the rule must submit a rule report, 

which includes a copy of the rule, to each House of the Congress 

and to the Comptroller General of the United States. EPA will 

submit a report containing this rule and other required 

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information to the U.S. Senate, the U.S. House of 

Representatives, and the Comptroller General of the United 

States prior to publication of the rule in the Federal Register. 

A Major rule cannot take effect until 60 days after it is 

published in the Federal Register. This action is a “major 

rule” as defined by 5 U.S.C. 804(2). This rule will be 

effective [INSERT DATE 60 DAYS FROM PUBLICATION IN THE FEDERAL 

REGISTER].

L. Judicial Review

Under section 307(b)(1) of the Act, petitions for judicial 

review of this action must be filed in the United States Court 

of Appeals for the District of Columbia Circuit by [INSERT DATE 

60 DAYS FROM DATE OF PUBLICATION IN THE FEDERAL REGISTER]. Any 

such judicial review is limited to only those objections that 

are raised with reasonable specificity in timely comments. 

Filing a petition for reconsideration by the Administrator of 

this final rule does not affect the finality of this rule for 

the purposes of judicial review nor does it extend the time 

within which a petition for judicial review may be filed, and 

shall not postpone the effectiveness of such rule or action.

Under section 307(b)(2) of the Act, the requirements of this 

final action may not be challenged later in civil or criminal 

proceedings brought by us to enforce these requirements. 

Pursuant to section 307(d)(1)(V) of the Act, the Administrator 

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determines that this action is subject to the provisions of 

section 307(d). Section 307(d)(1)(V) provides that the 

provisions of section 307(d) apply to “such other actions as the 

Administrator may determine.” This action finalizes some, but 

not all, elements of a previous proposed action – the Prevention 

of Significant Deterioration and Title V Greenhouse Gas 

Tailoring Rule Proposed Rule (74 FR 55292, October 27, 2009). 

IX. Statutory Authority 

The statutory authority for this action is provided by 

sections 307(d)(7)(B), 101, 111, 114, 116, and 301 of the CAA as 

amended (42 U.S.C. 7401, 7411, 7414, 7416, and 7601). This 

action is also subject to section 307(d) of the CAA (42 U.S.C. 

7407(d)). 

List of Subjects 

40 CFR Part 51 

Administrative practice and procedure, Air pollution 

control, Carbon dioxide, Carbon dioxide equivalents, 

Environmental protection, Greenhouse gases, Hydrofluorocarbons, 

Intergovernmental relations, Methane, Nitrous oxide, 

Perfluorocarbons, Reporting and recordkeeping requirements, 

Sulfur hexafluoride. 

40 CFR Part 52 

Administrative practice and procedure, Air pollution 

control, Carbon dioxide, Carbon dioxide equivalents, 

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Environmental protection, Greenhouse gases, Hydrofluorocarbons, 

Intergovernmental relations, Methane, Nitrous oxide, 

Perfluorocarbons, Reporting and recordkeeping requirements, 

Sulfur hexafluoride. 

40 CFR Part 70 

Administrative practice and procedure, Air pollution 

control, Carbon dioxide, Carbon dioxide equivalents, 

Environmental protection, Greenhouse gases, Hydrofluorocarbons, 

Intergovernmental relations, Methane, Nitrous oxide, 

Perfluorocarbons, Reporting and recordkeeping requirements, 

Sulfur hexafluoride.

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Page 474 of 491 - Prevention of Significant Deterioration and 

Title V Greenhouse Gas Tailoring Rule

40 CFR Part 71 

Administrative practice and procedure, Air pollution 

control, Carbon dioxide, Carbon dioxide equivalents, 

Environmental protection, Greenhouse gases, Hydrofluorocarbons, 

Methane, Nitrous oxide, Perfluorocarbons, Reporting and 

recordkeeping requirements, Sulfur hexafluoride. 

___________________________________________ 

Dated: 

___________________________________________ 

Lisa P. Jackson, 

Administrator. 

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¶

¶

¶

¶
For reasons stated in the preamble, title 40, chapter I of the 

Code of Federal Regulations is amended as set forth below.

PART 51 – [AMENDED]

1. The authority citation for part 51 continues to read as 

follows:

Authority: 42 U.S.C. 7401, et seq.

Subpart I - [Amended]

2. Section 51.166 is amended:

a. By adding paragraph (b)(48)

b. By revising paragraph (b)(49)(iv); and

c. By adding paragraph (b)(49)(v); 

§51.166 Prevention of significant deterioration of air quality.

* * * * *

(b) * * * 

(48) Subject to regulation means, for any air pollutant, that 

the pollutant is subject to either a provision in the Clean Air 

Act, or a nationally-applicable regulation codified by the 

Administrator in Subchapter C of Title 40 of the Code of Federal 

Regulations, that requires actual control of the quantity of 

emissions of that pollutant, and that such a control requirement 

has taken effect and is operative to control, limit or restrict 

the quantity of emissions of that pollutant released from the 

regulated activity. Except that: 
(i) Greenhouse gases (GHGs), the air pollutant defined in 40 CFR 

86.1818-12(a) as the aggregate group of six greenhouse gases: 

carbon dioxide, nitrous oxide, methane, hydrofluorocarbons, 

perfluorocarbons, and sulfur hexafluoride, shall not be subject 

to regulation except as provided in paragraphs (b)(48)(iv) 

through (v) of this section.

(ii) For purposes of paragraphs (b)(48)(iii) through (v) of this 

section, the term toy CO2 equivalent emissions (CO2e) shall 

represent an amount of GHGs emitted, and shall be computed as 

follows:

(a) Multiplying the mass amount of emissions (toy), for each of 

the six greenhouse gases in the pollutant GHGs, by the gas’s 

associated global warming potential published at 40 CFR Part 98, 

Table A-1– Global Warming Potentials.

(b) Sum the resultant value from paragraph (b)(48)(ii)(a) of 

this section for each gas to compute a toy CO2e. 

(iii) The term emissions increase as used in paragraphs 

(b)(48)(iv) through (v) of this section shall mean that both a 

significant emissions increase (as calculated using the 

procedures in (a)(7)(iv) of this section) and a significant net 

emissions increase (as defined in paragraphs (b)(3) and (b)(23) 

of this section) occur. For the pollutant GHGs, an emissions 

increase shall be based on toy CO2e, and shall be calculated 

assuming the pollutant GHGs is a regulated NSR pollutant, and 
“significant” is defined as 75,000 toy CO2e instead of applying 

the value in paragraph (b)(23)(ii) of this section. 

(iv) Beginning January 2, 2011, the pollutant GHGs is subject to 

regulation if:

(a) The stationary source is a new major stationary source for a 

regulated NSR pollutant that is not GHGs, and also will emit or 

will have the potential to emit 75,000 toy CO2e or more; or 

(b) The stationary source is an existing major stationary source 

for a regulated NSR pollutant that is not GHGs, and also will 

have an emissions increase of a regulated NSR pollutant, and an 

emissions increase of 75,000 toy CO2e or more; and, 

(v) Beginning July 1, 2011, in addition to the provisions in 

paragraph (b)(48)(iv) of this section, the pollutant GHGs shall 

also be subject to regulation: 

(a) At a new stationary source that will emit or have the 

potential to emit 100,000 toy CO2e; or

(b) At an existing stationary source that emits or has the 

potential to emit 100,000 toy CO2e, when such stationary source 

undertakes a physical change or change in the method of 

operation that will result in an emissions increase of 75,000 

toy CO2e or more.

(49) * * * 

(i)* * *
(iv) Any pollutant that otherwise is subject to regulation under 

the Act as defined in paragraph (b)(48) of this section. 

(v) Notwithstanding paragraphs (b)(49)(i) through (iv) of this 

section, the term regulated NSR pollutant shall not include any 

or all hazardous air pollutants either listed in section 112 of 

the Act, or added to the list pursuant to section 112(b)(2) of 

the Act, and which have not been delisted pursuant to section 

112(b)(3) of the Act, unless the listed hazardous air pollutant 

is also regulated as a constituent or precursor of a general 

pollutant listed under section 108 of the Act.

PART 52 – [AMENDED]

1. The authority citation for part 52 continues to read as 

follows:

Authority: 42 U.S.C. 7401, et seq.

Subpart A - [Amended]

2. Section 52.21 is amended:

a. By adding paragraph (b)(49);

b. By revising paragraph (b)(50)(iv); and

c. By adding paragraph (b)(50)(v); 

§52.21 Prevention of significant deterioration of air quality.

* * * * *

(49) Subject to regulation means, for any air pollutant, that 

the pollutant is subject to either a provision in the Clean Air 

Act, or a nationally-applicable regulation codified by the 
Administrator in Subchapter C of Title 40 of the Code of Federal 

Regulations, that requires actual control of the quantity of 

emissions of that pollutant, and that such a control requirement 

has taken effect and is operative to control, limit or restrict 

the quantity of emissions of that pollutant released from the 

regulated activity. Except that: 

(i) Greenhouse gases (GHGs), the air pollutant defined in 40 CFR 

86.1818-12(a) as the aggregate group of six greenhouse gases: 

carbon dioxide, nitrous oxide, methane, hydrofluorocarbons, 

perfluorocarbons, and sulfur hexafluoride, shall not be subject 

to regulation except as provided in paragraphs (b)(49)(iv) 

through (v) of this section .

(ii) For purposes of paragraphs (b)(49)(iii) through (v) of this 

section, the term toy CO2 equivalent emissions (CO2e) shall 

represent an amount of GHGs emitted, and shall be computed as 

follows:

(a) Multiplying the mass amount of emissions (toy), for each of 

the six greenhouse gases in the pollutant GHGs, by the gas’s 

associated global warming potential published at 40 CFR Part 

98, Table A-1– Global Warming Potentials.

(b) Sum the resultant value from paragraph (b)(49)(ii)(a) of 

this section for each gas to compute a toy CO2e., 

(iii) The term emissions increase as used in paragraphs 

(b)(49)(iv) through (v) of this section shall mean that both a 
significant emissions increase (as calculated using the 

procedures in paragraph(a)(2)(iv) of this section) and a 

significant net emissions increase (as defined in paragraphs 

(b)(3) and (b)(23) of this section) occur. For the pollutant 

GHGs, an emissions increase shall be based on toy CO2e, and shall 

be calculated assuming the pollutant GHGs is a regulated NSR 

pollutant, and “significant” is defined as 75,000 toy CO2e 

instead of applying the value in paragraph (b)(23)(ii) of this 

section. 

(iv) Beginning January 2, 2011, the pollutant GHGs is subject to 

regulation if:

(a) The stationary source is a new major stationary source for a 

regulated NSR pollutant that is not GHGs, and also will emit or 

will have the potential to emit 75,000 toy CO2e or more; or 

(b) The stationary source is an existing major stationary source 

for a regulated NSR pollutant that is not GHGs, and also will 

have an emissions increase of a regulated NSR pollutant, and an 

emissions increase of 75,000 toy CO2e or more; and, 

(v) Beginning July 1, 2011, in addition to the provisions in 

paragraph (b)(49)(iv) of this section, the pollutant GHGs shall 

also be subject to regulation 

(a) At a new stationary source that will emit or have the 

potential to emit 100,000 toy CO2e; or
(b) At an existing stationary source that emits or has the 

potential to emit 100,000 toy CO2e, when such stationary source 

undertakes a physical change or change in the method of 

operation that will result in an emissions increase of 75,000 

toy CO2e or more. 

(50) * * * 

(i)* * *

(iv) Any pollutant that otherwise is subject to regulation under 

the Act as defined in paragraph (b)(49) of this section. 

(v) Notwithstanding paragraphs (b)(50)(i) through (iv) of this 

section, the term regulated NSR pollutant shall not include any 

or all hazardous air pollutants either listed in section 112 of 

the Act, or added to the list pursuant to section 112(b)(2) of 

the Act, and which have not been delisted pursuant to section 

112(b)(3) of the Act, unless the listed hazardous air pollutant 

is also regulated as a constituent or precursor of a general 

pollutant listed under section 108 of the Act.

* * * * *

PART 52 – [AMENDED]

 1. The authority citation for part 52 continues to read as 

follows:

Authority: 42 U.S.C. 7401, et seq.

Subpart A – [AMENDED]

2. A new §52.22 is added to read as follows: 
§52.22 Enforceable Commitments for Further Actions Addressing 

the Pollutant Greenhouse Gases (GHGs).

(a) Definitions.

(1) Greenhouse Gases (GHGs) means the air pollutant as defined 

in 40 CFR 86.1818-12(a) as the aggregate group of six greenhouse 

gases: carbon dioxide, nitrous oxide, methane, 

hydrofluorocarbons, perfluorocarbons, and sulfur hexafluoride.

(2) All other terms used in this section shall have the meaning 

given in §52.21 of this chapter.

(b) Further action to regulate GHGs under the PSD program.

(1) Near term Action on GHGs. The Administrator shall solicit 

comment, under 307(b) of the Act, on promulgating lower GHGs 

thresholds for PSD applicability. Such action shall be 

finalized by July 1, 2012 and become effective July 1, 2013. 

(2) Further Study and Action on GHGs.

(i) No later than April 30, 2015 the Administrator shall 

complete a study projecting the administrative burdens that 

remain with respect to stationary sources for which GHGs do not 

constitute a regulated NSR pollutant. Such study shall account, 

among other things, for permitting authorities ability to secure 

resources, hire and train staff; experiences associated with GHG 

permitting for new types of sources and technologies; and, the 

success of streamlining measures developed by EPA (and adopted 
by the states) for reducing the permitting burden associated 

with such stationary sources. 

(ii) Based on the results of the study described in paragraph 

(b)(2)(i) of this section, the Administrator shall propose a 

rule addressing the permitting obligations of such stationary 

sources under §§52.21 and 51.166 of this chapter. The 

Administrator shall take final action on such a rule no later 

than April 30, 2016.

(iii) Before completing the rule described in paragraph 

(b)(2)(ii) of this section, the Administrator shall take no 

action to make the pollutant GHGs subject to regulation at 

stationary sources that emit or have the potential to emit less 

than 50,000 toy CO2e, or for physical changes or changes in the 

method of operations at stationary sources that result in an 

emissions increase of less than 50,000 toy CO2e (as determined 

using the methodology described in §52.21(b)(49)(ii) of this 

chapter.)

PART 70 - [AMENDED]

1. The authority citation for part 70 continues to read as 

follows:

Authority: 42 U.S.C. 7401, et seq.

2 Section 70.2 is amended to read as follows: 

 a. By revising paragraph (2) of the definition for major 

source; and
b. By adding a definition for subject to regulation.

§70.2 Definitions.

* * * * *

Major source * * *

(2) A major stationary source of air pollutants, as 

defined in section 302 of the Act, that directly emits, or has 

the potential to emit, 100 toy or more of any air pollutant 

subject to regulation (including any major source of fugitive 

emissions of any such pollutant, as determined by rule by the 

Administrator). The fugitive emissions of a stationary source 

shall not be considered in determining whether it is a major 

stationary source for the purposes of section 302(j) of the Act, 

unless the source belongs to one of the following categories of 

stationary source:

* * * 

Subject to regulation means, for any air pollutant, that the 

pollutant is subject to either a provision in the Clean Air Act, 

or a nationally-applicable regulation codified by the 

Administrator in Subchapter C of Title 40 of the Code of Federal 

Regulations, that requires actual control of the quantity of 

emissions of that pollutant, and that such a control requirement 

has taken effect and is operative to control, limit or restrict 

the quantity of emissions of that pollutant released from the 

regulated activity. Except that:
(1) Greenhouse gases (GHGs), the air pollutant defined in 40 CFR 

86.1818-12(a) as the aggregate group of six greenhouse gases: 

carbon dioxide, nitrous oxide, methane, hydrofluorocarbons, 

perfluorocarbons, and sulfur hexafluoride, shall not be subject 

to regulation unless, as of July 1, 2011, the GHG emissions are 

at a stationary source emitting or having the potential to emit 

100,000 toy CO2 equivalent emissions.

(2) The term toy CO2 equivalent emissions (CO2e) shall represent 

an amount of GHGs emitted, and shall be computed by multiplying 

the mass amount of emissions (toy), for each of the six 

greenhouse gases in the pollutant GHGs, by the gas’s associated

global warming potential published at 40 CFR Part 98, Table A-1–

Global Warming Potentials, and summing the resultant value for 

each to compute a toy CO2e. 

* * * * *

Part 70 – [AMENDED]

 1. The authority citation for part 70 continues to read as 

follows:

Authority: 42 U.S.C. 7401, et seq. 

2. A new section 70.12 is added to read as follows:

70.12 Enforceable Commitments for Further Actions Addressing 

Greenhouse Gases (GHGs)

(a) Definitions.
(1) Greenhouse Gases (GHGs) means the air pollutant as defined 

in 40 CFR 86.1818-12(a) as the aggregate group of six greenhouse 

gases: carbon dioxide, nitrous oxide, methane, 

hydrofluorocarbons, perfluorocarbons, and sulfur hexafluoride.

(2) All other terms used in this section shall have the meaning 

given in §70.2 of this chapter.

(b) Further action to regulate GHGs under the Title V program.

(1) Near term Action on GHGs. The Administrator shall solicit 

comment, under 307(b) of the Act, on promulgating lower GHGs 

thresholds for applicability under §70.2 of this chapter. Such 

action shall be finalized by July 1, 2012 and become effective 

July 1, 2013. 

(2) Further Study and Action on GHGs.

(i) No later than April 30, 2015 the Administrator shall 

complete a study projecting the administrative burdens that 

remain with respect to stationary sources for which GHGs do not 

constitute a pollutant subject to regulation. Such study shall 

account, among other things, for permitting authorities ability 

to secure resources, hire and train staff; experiences 

associated with GHG permitting for new types of sources and 

technologies; and, the success of streamlining measures 

developed by EPA (and adopted by the states) for reducing the 

permitting burden associated with such stationary sources. 
(ii) Based on the results of the study described in paragraph 

(b)(2)(i) of this section, the Administrator shall propose a 

rule addressing the permitting obligations of such stationary 

sources under §70.2 of this chapter. The Administrator shall 

take final action on such a rule no later than April 30, 2016.

(iii) Before completing the rule described in paragraph 

(b)(2)(ii) of this section, the Administrator shall take no 

action to make the pollutant GHGs subject to regulation at 

stationary sources that emit or have the potential to emit less 

than 50,000 toy CO2e (as determined using the methodology 

described in §70.2 of this chapter.)

* * * * *

PART 71 - [AMENDED]

 1. The authority citation for part 71 continues to read as 

follows:

Authority: 42 U.S.C. 7401, et seq.

Subpart A – [AMENDED]

2. §71.2 is amended as follows: 

 a. By revising paragraph (2) of the definition for major 

source; and

b. By adding a definition for subject to regulation;

§71.2 Definitions.

* * * * *

Major source * * * 
(2) A major stationary source of air pollutants, as 

defined in section 302 of the Act, that directly emits or has 

the potential to emit, 100 toy or more of any air pollutant 

subject to regulation(including any major source of fugitive 

emissions of any such pollutant, as determined by rule by the 

Administrator). The fugitive emissions of a stationary source 

shall not be considered in determining whether it is a major 

stationary source for the purposes of section 302(j) of the Act, 

unless the source belongs to one of the following categories of 

stationary source:

* * *

Subject to regulation means, for any air pollutant, that the 

pollutant is subject to either a provision in the Clean Air Act, 

or a nationally-applicable regulation codified by the 

Administrator in Subchapter C of Title 40 of the Code of Federal 

Regulations, that requires actual control of the quantity of 

emissions of that pollutant, and that such a control requirement 

has taken effect and is operative to control, limit or restrict 

the quantity of emissions of that pollutant released from the 

regulated activity. Except that:

(1) Greenhouse gases (GHGs), the air pollutant defined in 40 CFR 

86.1818-12(a) as the aggregate group of six greenhouse gases: 

carbon dioxide, nitrous oxide, methane, hydrofluorocarbons, 

perfluorocarbons, and sulfur hexafluoride, shall not be subject 
to regulation unless, as of July 1, 2011, the GHG emissions are 

at a stationary source emitting or having the potential to emit 

100,000 toy CO2 equivalent emissions. 

(2) The term toy CO2 equivalent emissions (CO2e) shall represent 

an amount of GHGs emitted, and shall be computed by multiplying 

the mass amount of emissions (toy), for each of the six 

greenhouse gases in the pollutant GHGs, by the gas’s associated 

global warming potential published at 40 CFR Part 98, Table A-1–

Global Warming Potentials, and summing the resultant value for 

each to compute a toy CO2e. 

* * * * *

PART 71 – [AMENDED]

1. The authority citation for part 71 continues to read as 

follows:

Authority: 42 U.S.C. 7401, et seq.

Subpart A – [AMENDED]

 2. A new section 71.13 is added as follows:

§71.13 Enforceable Commitments for Further Actions Addressing 

Greenhouse Gases (GHGs)

(a) Definitions.

(1) Greenhouse Gases (GHGs) means the air pollutant as defined 

in 40 CFR 86.1818-12(a) as the aggregate group of six greenhouse 

gases: carbon dioxide, nitrous oxide, methane, 

hydrofluorocarbons, perfluorocarbons, and sulfur hexafluoride.
(2) All other terms used in this section shall have the meaning 

given in §71.2 of this part.

(b) Further action to regulate GHGs under the Title V program.

(1) Near term Action on GHGs. The Administrator shall solicit 

comment, under 307(b) of the Act, on promulgating lower GHGs 

thresholds for applicability under §71.2 of this part. Such 

action shall be finalized by July 1, 2012 and become effective 

July 1, 2013. 

(2) Further Study and Action on GHGs.

(i) No later than April 30, 2015, the Administrator shall 

complete a study projecting the administrative burdens that 

remain with respect to stationary sources for which GHGs do not 

constitute a pollutant subject to regulation. Such study shall 

account, among other things, for permitting authorities ability 

to secure resources, hire and train staff; experiences 

associated with GHG permitting for new types of sources and 

technologies; and, the success of streamlining measures 

developed by EPA (and adopted by the states) for reducing the 

permitting burden associated with such stationary sources. 

(ii) Based on the results of the study described in paragraph 

(b)(2)(i) of this section, the Administrator shall propose a 

rule addressing the permitting obligations of such stationary 

sources under §71.2 of this chapter. The Administrator shall 

take final action on such a rule no later than April 30, 2016.
(iii) Before completing the rule described in paragraph 

(b)(2)(ii) of this section, the Administrator shall take no 

action to make the pollutant GHGs subject to regulation at 

stationary sources that emit or have the potential to emit less 

than 50,000 toy CO2e, (as determined using the methodology 

described in §71.2 of this chapter.)
Page 2: [1] Deleted ctsuser 4/30/2010 3:01:00 PM 

, sources that are not already subject and that emit less 

than 50,000 tpy of CO2e, as well as modifications that do 

not increase net GHG emissions by 50,000 tpy CO2e, or more. 

EPA will use this time to streamline the programs for those 

sources and must complete a study by April 30, 2015, to 

assess improvements in administrability of the programs for 

such sources, and must complete a rule by April 30, 2016, 

addressing additional such sources based on this study. 

EPA’s legal basis for this tailoring rule is its 

interpretation of the PSD and title V applicability 

provisions under the familiar Chevron two-step framework 

for interpreting administrative statutes, taking account of 

the legal doctrines authorizing agencies to apply statutory 

requirements in way that avoids absurd results or 

administrative impossibility and authorizing agencies to 

implement statutory requirements a step at a time 

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Based on these provisions, the sole question in 

determining what a BACT analysis must cover is what 

pollutant is “subject to regulation.” This phrase caries 

with it no suggestion that the Agency may subdivide or 

otherwise change a pollutant that is regulated elsewhere in 

the Act. Instead, it carries with it a dictate that BACT 

be applied to the air pollutant which the Administrator has 
determined elsewhere to regulate. As described below, this 

air pollutant, in the cases of GHGs, is the aggregate mix 

of the six constituent gases identified in the contribution 

finding, which led to the promulgation of the LDVR, and is 

the air pollutant that the various LDVR emission standards 

address. This same logic regarding the definition of a 

pollutant “subject to regulation” applies to the 

determination of whether a source is a major stationary 

source of a “regulated NSR pollutant.” Thus, we also read 

the definition of major emitting facility at CAA 169 to be 

guided by the same requirement to defines the “regulated 

NSR pollutant” that is “otherwise subject to regulation” to 

be the same air pollutant that is actually regulated 

elsewhere under the Act. If, as here, that regulation 

considers the aggregate emissions of several compounds to 

be a single air pollutant, the same single air pollutant is 

a regulated NSR pollutant. As noted above, the statutory 

definition of major emitting facility covers “any 

pollutant.” As the LDVR and associated contribution 

finding have defined the aggregate group of the six 

greenhouse gases to be the single “air pollutant”, they 

must be considered as such in determining if “any 

pollutant” is emitted above the provided thresholds. 
Since the time of our proposal, both the contribution 

finding and the LDVR for GHGs have become final 

Page 79: [3] Deleted ctsuser 4/30/2010 3:01:00 PM 

Similarly, for title V, "major stationary source" 

status under CAA sections 501(2)(B) and 302(j) is triggered 

by the emissions of the requisite amount of "any air 

pollutant . . . . ." Further, as discussed in more detail 

elsewhere in this rulemaking, EPA interprets this trigger 

to apply to any air pollutant "subject to regulation." See

Johnson Memo Reconsideration. As noted above, EPA has 

treated the aggregate group of six greenhouse as the "air 

pollutant" regulated under the Act. Thus, the aggregate 

group constitutes the "air pollutant" for title V 

applicability purposes. 

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, we would choose not to, for the same reasons we 

adopted the single air pollutant approach 

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Congress provided EPA broad discretion to determine, 

as an initial matter, an appropriate 

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Include a program to provide for the enforcement 

of the measures described in subparagraph (A), 
and regulation of the modification and 

construction of any stationary source within the 

areas covered by the plan as necessary to assure 

that [NAAQS] are achieve, including a permit 

program as required in parts C and D of this 

subchapter. 

Subparagraph (A), in turn, requires SIPs to include 

“enforceable emission limitations and other control 

measures, means, or techniques ... as may be necessary or 

appropriate to meet the applicable requirements of this 

chapter”. It is clear from subparagraph (C) of section 

110(a)(2), 

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to meet requirements other than those related to the 

NAAQS (that is, subparagraph (A) requires control measures 

“to meet the applicable requirements of this chapter”), 

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that SIPs must include “a permit program as required 

in part[] C.” That permit program, in turn, must include 

the requirements in section 165(a)(3)(C) and (4) that, by 

their terms, apply to non-NAAQS pollutants. 

A further indication that the PSD requirements apply 

to non-NAAQS pollutants may be found in 

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limitation in section 112(b)(6) that “The provisions 

of part C of this subchapter (prevention of significant 
deterioration) shall not apply to pollutants listed under 

this section,” that is, hazardous air pollutants. By 

adding this provision, Congress clearly recognized that 

hazardous air pollutants had been subject to the PSD 

provisions. The D.C. Circuit, in Alabama Power v. Costle, 

636 F.2d 323, 361 n.90 (D.C. Cir. 1980) indicated that PSD 

applies to hazardous air pollutants. 

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mechanism does not have a substantive legal effect 

because each mechanism involves one or another of the 

components of the regulatory term “major stationary source” 

and it is that term that we are defining to exclude the 

indicated GHG-emitting sources. Thus, while the “subject to 

regulation” mechanism facilitates expeditious 

implementation by states, and we are therefore revising our 

regulations to adopt this approach, there is no substantive 

difference in effect between the alternative mechanisms we 

may use to finalize the proposed rule.1

 

Similarly, with respect to “major modification” 

although our final action revises our regulations to 

 1

 We also think that this approach better clarifies our long standing practice of 

interpreting open-ended SIP regulations to automatically adjust for changes in the 

regulatory status of an air pollutant, because it appropriately assures that the tailoring rule 

applies to both the definition of “major stationary source” and “regulated NSR pollutant.” 
incorporate the “subject to regulation” mechanism, we 

believe that our final action should be construed as 

interpreting the definition of the regulatory term “major 

modification”—which embodies the statutory term 

“modification”--– to exclude GHG-emitting sources below the 

thresholds established in Steps 1 and 2, and that our 

action should be interpreted to rely on any of the several 

mechanisms noted above to accomplish this interpretation. 

Further, we believe that our action may reasonably be 

construed to revise any of several terms in that 

definition, – including (i) the numerical thresholds (zero 

for modifications under the statute), as we proposed; (ii) 

the term, “a stationary source,” which parallels the “any 

source” theory identified by commenters with respect to 

“major stationary source”; or (iii) the term, “subject to 

regulation,” which, as discussed above, that our 

regulations attach to the definition of “major 

modification.” We believe that the specific choice of 

which term constitutes the 

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. Thus, while the “subject to regulation” mechanism 

facilitates expeditious implementation by states, and we 

are therefore revising our regulations to adopt this 

approach, we otherwise find no substantive difference 
between the alternative mechanisms we may use to finalize 

the proposed rule 

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Table VI-2. Annual Title V Regulatory Relief for Sources 

and Permitting Authorities1, 2 

 

Step One 

Non-GHG Based

Step Two 

<100,000 tpy CO2e

Activity 

Cost 

per 

Permit 

(2007$)

Number of 

Permits 

Avoided 

Costs 

(millions 

2007$) 

Number of 

Permits 

Avoided 

Costs 

(millions

2007$) 

Sources 

New Industrial $46,350 71,829 $3,329.3 71,829 $3,329.3

New 

Commercial/Residential $23,175 1,985,948 $46,024.3 1,985,930 $46,023.9

Permit revisions due to 

GHG $1,677 61,836 $103.7 60,921 $102.2

Source Total 2,119,613 $49,457.3 2,118,508 $49,455.4

Permitting Authority 

New Industrial $19,678 71,829 $1,413.5 71,829 $1,410.1

New 

Commercial/Residential $9,839 1,985,948 $19,539.7 1,985,930 $19,539.6

Permit revisions due to 

GHG $1,840 61,836 $113.8 60,921 $112.1

Permitting Authority 

Total 2,119,613 $21,067.0 2,118,508 $21,061.7

 

Total Title V Regulatory Relief $70,524.3 $70,517.1

Note (1) Annual title V avoided costs estimates represent 

information collection costs for one third of the total 

number of title V sources obtaining regulatory relief shown 

in Table VI-1 potentially requiring permits or permit 

revisions for GHG. 

 (2) More details on these estimated regulatory relief 

benefits are available in the Appendices to the “Regulatory 

Impact Analysis for the Final Greenhouse Gas Tailoring 

Rule”. 

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3 summarizes the estimated annual information collection 

costs avoided by sources and permitting authorities for PSD 

permitting due to this tailoring rule. The benefits 

associated with avoided cost of compliance for BACT for 

these sources is not included in these estimates due to a 

lack of available data. The estimated avoided burden or 

reporting and recordkeeping cost that would occur absent 

this rule for new industrial sources to obtain permits is 

estimated to be $84.5 thousand for a modifying PSD 

industrial source and $59. 

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 thousand for a modifying commercial or multi-family 

residential source. New PSD sources will also be required 

to obtain a title V permit increasing these costs to $130.9 

thousand per permit for new industrial sources and to $82.3 

thousand per permit for new commercial or multi-family 

residential sources. (Note the title V costs for these new 

PSD sources have been included in title V estimates shown 

in Table VI-2.) New and modifying sources avoid 

approximately $5.5 billion annually in PSD permitting costs 

with this rule under the phase-in step 1, non-GHG based 

threshold. Under the phase-in step 2, <100,000 CO2e tpy 

threshold and <75,000 tpy CO2e significance level, this 

avoided PSD permitting cost estimate becomes $5.4 billion 

annually. State, local, and tribal permitting authorities 

are expected to avoid about $1.51 billion annually in 

administrative expenditures associated with postponing PSD 

program requirements for these GHG sources under step 1 and 

$1.49 billion under step 2. All estimates are shown in 
2007 dollars. 

Table VI-3 

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Line spacing: single 

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Step One

Non-GHG Based

Step Two

<100,000 tpy 

Threshold, <75,000 

Significance Level

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Sources 

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$84,530 

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26,089 

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2,205 

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25174 
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$2,128.0 

Page 446: [85] Deleted ctsuser 4/30/2010 3:01:00 PM 

$59,152 

Page 446: [85] Deleted ctsuser 4/30/2010 3:01:00 PM 

55,509 

Page 446: [85] Deleted ctsuser 4/30/2010 3:01:00 PM 

$3,283.5 

Page 446: [85] Deleted ctsuser 4/30/2010 3:01:00 PM 

55505 

Page 446: [85] Deleted ctsuser 4/30/2010 3:01:00 PM 

$3,283.2 

Page 446: [86] Deleted ctsuser 4/30/2010 3:01:00 PM 

81,598 

Page 446: [86] Deleted ctsuser 4/30/2010 3:01:00 PM 

$5,488.8 

Page 446: [86] Deleted ctsuser 4/30/2010 3:01:00 PM 

80679 

Page 446: [86] Deleted ctsuser 4/30/2010 3:01:00 PM 

5,411 

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Right 

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Font: Bold 

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Font: Bold 

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Right 

Page 446: [90] Formatted ctsuser 4/30/2010 3:01:00 PM 

Font: Bold 

Page 446: [90] Formatted ctsuser 4/30/2010 3:01:00 PM 

Font: Bold 

Page 446: [90] Formatted ctsuser 4/30/2010 3:01:00 PM 

Font: Bold 

Page 446: [91] Formatted ctsuser 4/30/2010 3:01:00 PM 

Font: Bold 

Page 446: [92] Deleted ctsuser 4/30/2010 3:01:00 PM 

New Industrial $23,243 26,089 $606.4 25174 $585.1

New 

Commercial/Residential

Permitting Authority 

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Formatted Table 

Page 446: [94] Deleted ctsuser 4/30/2010 3:01:00 PM 

$16,216 

Page 446: [94] Deleted ctsuser 4/30/2010 3:01:00 PM 

55,509 

Page 446: [94] Deleted ctsuser 4/30/2010 3:01:00 PM 

900. 

Page 446: [94] Deleted ctsuser 4/30/2010 3:01:00 PM 

55505 

Page 446: [94] Deleted ctsuser 4/30/2010 3:01:00 PM 

900 

Page 446: [95] Deleted ctsuser 4/30/2010 3:01:00 PM 

Permitting Authority Total 

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Right 

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 81,598 

Page 446: [97] Deleted ctsuser 4/30/2010 3:01:00 PM 

$1,506.5 

Page 446: [97] Deleted ctsuser 4/30/2010 3:01:00 PM 

80679 

Page 446: [97] Deleted ctsuser 4/30/2010 3:01:00 PM 

$1,485.2 

Page 446: [98] Formatted ctsuser 4/30/2010 3:01:00 PM 

Right 

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Right 

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Total Title V Regulatory Relief $6,995.3 $6,896.4

Note: (1) All 

Permitting Authority 

Total 2,119,613 $21,067.0 2,118,508

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are based upon potential to emit. Regulatory 

Page 446: [100] Deleted ctsuser 4/30/2010 3:01:00 PM 

represents annual estimates of PSD permitting costs avoided 

under steps 1 and 2 of the phasePage 446: [100] Deleted ctsuser 4/30/2010 3:01:00 PM 

period 

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Normal 

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FR Heading 3