United States Environmental Protection Agency, Region 9

Air Division

Technical Support Document

for

EPA's Notice of Final Rulemaking

for Revisions to the 

California State Implementation Plan

Eastern Kern Air Pollution Control District

Rule 210.4 – Prevention of Significant Deterioration

Imperial County Air Pollution Control District

Rule 904 – Prevention of Significant Deterioration (PSD) Permit Program

Placer County Air Pollution Control District

Rule 518 – Prevention of Significant Deterioration (PSD) Permit Program

Yolo-Solano Air Quality Management District

Rule 3.24 – Prevention of Significant Deterioration

Prepared by Lisa Beckham

Reviewed by Gerardo Rios

September 21, 2012
Table of Contents

Section Page

1. Introduction 1

2. PSD Program SIP Revision Submittal 1

3. What are the General Requirements of a SIP-Approved PSD Program? 2

4. Rule Summary 3

5. Rule Evaluation 6

6. Program Transfer and Implementation Issues 23

7. Section 110(a), 110(l), and 193 of the Act 25

8. Recommendations 25

9. Attachments 25
Page 1 of 25

1. Introduction

Part C of title I of the Clean Air Act (CAA or Act) contains the provisions for the Prevention of 

Significant Deterioration (PSD) of air quality in areas designated as “attainment” or 

“unclassifiable” for the national ambient air quality standards (NAAQS). Part D of title I of the Act 

contains the requirements for areas designated “nonattainment” for any NAAQS. Both parts C and 

D of the Act require pre-construction permit programs for certain new or modified stationary 

sources of pollutants. The PSD requirements under part C apply to certain new or modified sources 

that would be located within attainment areas, and apply to all “regulated NSR pollutants,” except 

those pollutants for which an area has been designated as “nonattainment.” The requirements 

under part D, referred to as “Nonattainment New Source Review,” apply to certain new or 

modified sources of nonattainment pollutants located in nonattainment areas. Collectively, the 

pre-construction permit requirements related to PSD and Nonattainment New Source Review are 

simply referred to as “New Source Review” or “NSR.” Both of these programs apply to “major 

stationary sources” and “major modifications” as those terms are defined in Title 40 of the Code of 

Federal Regulations (CFR) Part 51, Subpart I. In addition to the regulation of major stationary 

sources, states are also required to adopt a program to provide for the regulation of the construction 

and modification of minor stationary sources and minor modifications at major sources, to assure 

that the NAAQS are achieved and/or maintained. These pre-construction program requirements 

are commonly referred to as “minor NSR” (see 40 CFR 51.160-164). This technical support 

document (TSD) specifically addresses the requirements of Part C of title I of the Act and the 

implementing regulations at 40 CFR 51.166 governing PSD programs in State Implementation 

Plans (SIPs).

2. PSD Program SIP Revision Submittals

The following rules were adopted or amended by local permitting agencies within California (see 

Attachment 1):

• Eastern Kern Air Pollution Control District (Eastern Kern or EKAPCD) – Rule 210.4 –

Prevention of Significant Deterioration, amended January 12, 2012

• Imperial County Air Pollution Control District (Imperial or ICAPCD) – Rule 904 –

Prevention of Significant Deterioration (PSD) Permit Program, amended December 20, 

2011

• Placer County Air Pollution Control District (Placer or PCAPCD) – Rule 518 – Prevention 

of Significant Deterioration (PSD) Permit Program, adopted February 10, 2011

• Yolo-Solano Air Quality Management District (Yolo-Solano or YSAQMD) – Rule 3.24 –

Prevention of Significant Deterioration, adopted June 13, 2012

In letters dated June 21, 2011, February 23, 2012, April 25, 2012, and July 3, 2012, the California 

Air Resources Board (ARB) submitted rule packages for the rules listed above to Region 9 of the 

United States Environmental Protection Agency (EPA) as revisions to California’s SIP. The ARB 

is the California governor’s designee for submitting official revisions of the California SIP to the

EPA. These Districts currently do not have SIP-approved PSD programs as required by part C of 

title I of the Act and 40 CFR 51.166. EPA’s approval of ARB’s SIP submittal packages into the 
Page 2 of 25

California SIP would transfer authority and responsibility for implementation of the PSD 

permitting program from EPA to the Districts.

During our review process, EPA requested that the Districts provide certain clarifications 

regarding the submitted PSD rules and how the Districts would implement its rules to ensure that 

each PSD program satisfies the requirements of 40 CFR 51.166 for PSD programs. The letters also 

requested that the Districts provide further confirmation and explanation concerning (1) the 

District’s authority, personnel, and funding to implement the PSD program within the District 

pursuant to Clean Air Act Section 110(a)(2)(E)(i), and (2), if applicable, the District’s request to 

implement the PSD program with respect to existing PSD permits issued by EPA. The Districts

subsequently provided the requested information (see Attachments 2 and 5).

The SIP submittal packages for these PSD rules were reviewed and determined complete 

according to Appendix V of 40 CFR Part 51.

3. What are the General Requirements of a SIP-Approved PSD Program?

The PSD program is a preconstruction review and permitting program applicable to certain new 

major stationary sources and major modifications at existing major stationary sources. The 

specific requirements applicable to SIP-approved PSD programs are contained in 40 CFR 51.166. 

The PSD program applies to any regulated NSR pollutant (as defined in 40 CFR 51.166), except 

for pollutants designated nonattainment for a NAAQS. The CAA defines “nonattainment areas” as 

air quality planning areas that exceed the national primary or secondary NAAQS for a given 

criteria pollutant (or that contribute to ambient air quality in a nearby area that does not meet the 

NAAQS). In some instances the emission increases of a particular pollutant may be subject to the 

PSD program and the Nonattainment NSR program. For example, nitrogen oxides (NOx) from a 

source in an area designated as attainment for the nitrogen dioxide (NO2) NAAQS and 

nonattainment for the ozone NAAQS would be subject to both permitting programs because NOx

would be a PSD pollutant as well as a precursor to ozone, a nonattainment pollutant.

The applicability of PSD to a particular source must be determined in advance of construction or 

modification and is pollutant-specific. The primary criterion is whether the proposed project is 

sufficiently large (in terms of its emissions) to be a major stationary source or major modification, 

both of which are described below. 

Section 169 of the CAA specifies the emissions threshold, depending on source category, which is 

used to determine whether a source is a “major emitting facility” and subject to PSD. For PSD 

purposes, a “major stationary source” is any source belonging to a specified list of 28 source 

categories1 that emits or has the potential to emit (PTE) 100 tons per year (tpy) or more of any air 

pollutant subject to regulation under the CAA, or belonging to any other source category that emits 

or has the PTE for such pollutants in amounts equal to or greater than 250 tpy. A new source with 

a PTE at or above the applicable “major stationary source threshold” is subject to PSD for any 

other regulated NSR pollutant emitted in “significant” amounts. Significance levels, which EPA 

 1 See 40 CFR 51.166(b)(1)(i) for the 28-source category list.
Page 3 of 25

has promulgated for criteria pollutants and certain other pollutants, represent a threshold for a de 

minimis contribution to air quality problems. When EPA has not set a significance level for a 

pollutant, PSD applies to an increase of the regulated pollutant in any amount (that is, in effect, the 

significance level is treated as zero).

PSD also applies to existing sources that undertake a “major modification,” which occurs when: 

(1) there is a physical change, or change in the method of operation, at a “major stationary source;” 

(2) the change results in a “significant” emissions increase of a pollutant subject to PSD regulation 

(at or above the significance level that EPA has set for the pollutant); and (3) there is a “significant 

net emissions increase” of a pollutant subject to PSD regulation that is at or above the significance 

level (as defined in 40 CFR 51.166(b)(23)). 

On January 2, 2011, greenhouse gases (GHGs) became subject to regulation under the CAA. 

EPA adopted new provisions in 40 CFR 51.166 and 40 CFR 52.21 to tailor the applicability 

criteria that determine which sources would become subject to permitting requirements for GHG 

emissions under the PSD and title V programs of the CAA, known as the “Tailoring Rule” (see 75 

FR 31514). The Tailoring Rule revised the definition of “subject to regulation” in 40 CFR 

51.166(b)(48) and 40 CFR 52.21(b)(49) to establish specific emission thresholds that determine 

when GHGs are considered subject to regulation and therefore subject to PSD permitting 

requirements. The emission thresholds for GHGs are:

1. For a new stationary source,

a. A PTE of at least 100,000 tpy of CO2 equivalent emissions (CO2e), OR

b. An emission increase of 75,000 tpy or more of CO2e at a source that is a new major 

stationary source for a pollutant other than GHGs. 

2. For an existing stationary source,

a. An emission increase of 75,000 tpy or more of CO2e at a source that has a PTE of at 

least 100,000 tpy of CO2e, OR

b. A significant emissions increase of any pollutant other than GHGs and an increase 

of 75,000 tpy or more of CO2e. 

4. Rule Summaries

4.1. Eastern Kern Rule 210.4

Rule 210.4 – Prevention of Significant Deterioration applies to pollutants designated as attainment 

or unclassifiable in the EKAPCD, as well as to other regulated NSR pollutants. However, 

consistent with the requirements for a PSD program, Rule 210.4 does not apply to pollutants in 

areas that are designated as nonattainment. Currently, Eastern Kern is designated either attainment 

or unclassifiable for the particulate matter 2.5 micrometers in diameter and smaller (PM2.5), NO2, 

sulfur dioxide (SO2), carbon dioxide (CO), and lead NAAQS, and a portion of the district is 

designated nonattainment for the ozone and particulate matter 10 micrometers in diameter and 

smaller (PM10) NAAQS. The EKAPCD does not take any credit in its attainment plans for ozone 

and PM10 for any emission reductions achieved as part of these PSD regulations. 
Page 4 of 25

Eastern Kern Rule 210.4 essentially incorporates by reference the federal PSD program as codified 

in 40 CFR Part 52.21, which is the Federal Implementation Plan (FIP) used by EPA to implement 

the required PSD program in areas that do not have a SIP-approved PSD program. Rule 210.4 is 

comprised of seven sections: 

Section I – Purpose 

Section II – Definitions

Section III – Applicability

Section IV – Incorporation by Reference

Section V – Exemption

Section VI – Requirements

Section VII – Public Participation

Section I outlines the purpose of the rule, which is to implement the PSD program by incorporating 

the federal PSD program by reference. With some revisions, Section II incorporates by reference 

the definitions in 40 CFR 52.21(b). Section III includes applicability provisions and provides that 

any source, and owner/operator of any source, subject to any requirement in 40 CFR 52.21, as 

incorporated into this rule, is subject to Rule 210.4. With some revisions and exceptions, Section 

IV incorporates by reference the provisions of 40 CFR Part 52.21 as of January 12, 2012. Section 

V provides an exemption from conducting an air quality analysis for GHGs. Section VI identifies 

the requirements necessary to administer the program, including the requirement to obtain a PSD

permit prior to beginning actual construction of a major stationary source or a major modification. 

Section VII contains the public noticing requirements for issuing a PSD permit. 

4.2. Imperial Rule 904

Rule 904 – Prevention of Significant Deterioration (PSD) Permit Program applies to pollutants 

designated as attainment or unclassifiable in the ICAPCD, as well as to other regulated NSR 

pollutants. However, consistent with the requirements for a PSD program, Rule 904 does not apply 

to pollutants in areas that are designated as nonattainment. Currently, the District is designated 

either attainment or unclassifiable for the NO2, SO2, CO, and lead NAAQS. The District is 

designated as nonattainment for the ozone and PM10 NAAQS and a portion of the District is 

designated nonattainment for the PM2.5 NAAQS. The ICAPCD does not take any credit in its 

attainment plans for ozone, PM10 and PM2.5 for any emission reductions achieved as part of these 

PSD regulations. 

Imperial Rule 904 essentially incorporates by reference the federal PSD program as codified in 40 

CFR Part 52.21, which is the FIP used by EPA to implement the required PSD program in areas 

that do not have a SIP-approved PSD program. Rule 904 is comprised of six sections: 

Section A – Purpose 

Section B – Applicability

Section C – Incorporation by Reference

Section D – Definitions

Section E – Requirements
Page 5 of 25

Section F – Public Participation

Section A outlines the purpose of the rule, which is to implement the PSD program by 

incorporating the federal PSD program by reference. Section B provides that any source, and the 

owner/operator of any source, subject to any requirement in 40 CFR 52.21, as incorporated into 

this rule, is subject to Rule 904. With some exceptions, Section C incorporates by reference the 

provisions of 40 CFR Part 52.21 as of December 20, 2011. With some revisions, Section D 

incorporates by reference the definitions in 40 CFR 52.21(b). Section E identifies the requirements 

necessary to administer the program, including the requirement to obtain a PSD permit prior to 

beginning actual construction of a major stationary source or a major modification. Section F

contains the public noticing requirements for issuing a PSD permit. 

4.3. Placer Rule 518

Rule 518 – Prevention of Significant Deterioration (PSD) Permit Program applies to pollutants 

designated as attainment or unclassifiable in the PCAPCD, as well as to other regulated NSR 

pollutants. However, consistent with the requirements for a PSD program, Rule 518 does not apply 

to pollutants in areas that are designated as nonattainment. Currently, the District is designated 

either attainment or unclassifiable for the PM10, NO2, SO2, CO, and lead NAAQS, and a portion of 

the district is designated nonattainment for the ozone and PM2.5 NAAQS. The PCAPCD does not 

take any credit in its attainment plans for ozone and PM2.5 for any emission reductions achieved as 

part of these PSD regulations. 

Placer Rule 518 essentially incorporates by reference the federal PSD program as codified in 40 

CFR Part 52.21, which is the FIP used by EPA to implement the required PSD program in areas 

that do not have a SIP-approved PSD program. Rule 518 is comprised of four sections: 

Section 100 – General

Section 200 – Definitions

Section 300 – Standards

Section 400 – Administrative Requirements

Section 100 contains the purpose and applicability of Rule 518, which is to adopt a PSD program 

by incorporating by reference the federal PSD program in 40 CFR 52.21 and to apply Rule 518 to 

any source, and the owner or operator of any source, subject to any requirement under 40 CFR 

52.21, as incorporated into Rule 518. Section 100 also incorporates 40 CFR 52.21, as of February 

10, 2011, into Rule 518 and exempts GHGs from air quality analyses. Section 200 revises some of 

the definitions and terms in 40 CFR 52.21, as incorporated by reference in Rule 518. Section 300 

identifies the requirements necessary to administer the program, including the requirement to 

obtain a PSD permit prior to beginning actual construction of a major stationary source or a major 

modification. Section 400 contains the public participation requirements for issuing a PSD permit. 
Page 6 of 25

4.4. Yolo-Solano Rule 3.24

Rule 3.24 – Prevention of Significant Deterioration applies to pollutants designated as attainment 

or unclassifiable in the YSAQMD, as well as to other regulated NSR pollutants. However, 

consistent with the requirements for a PSD program, Rule 3.24 does not apply to pollutants in 

areas that are designated as nonattainment. Currently, the District is either attainment or 

unclassifiable for the PM10, NO2, SO2, CO, and lead NAAQS and a portion of the YSAQMD is 

nonattainment for the ozone and PM2.5 NAAQS. The YSAQMD does not take any credit in its 

attainment plans for ozone and PM2.5 for any emission reductions achieved as part of these PSD 

regulations. 

Yolo-Solano Rule 3.24 essentially incorporates by reference the federal PSD program as codified 

in 40 CFR Part 52.21, which is the Federal Implementation Plan (FIP) used by EPA to implement 

the required PSD program in areas that do not have a SIP-approved PSD program. Rule 3.24 is 

comprised of four sections: 

Section 100 – General

Section 200 – Definitions

Section 300 – Standards

Section 400 – Administrative Requirements

Section 100 contains the purpose and applicability of Rule 3.24, which is to adopt a PSD program 

by incorporating by reference the federal PSD program in 40 CFR 52.21 and to apply Rule 3.24 to 

any source and the owner or operator of any source subject to any requirement under 40 CFR 

52.21, as incorporated into Rule 3.24. Section 100 also incorporates 40 CFR 52.21, as of June 13, 

2012, into Rule 3.24 and exempts GHGs from air quality analyses. Section 200 revises some of the 

terms in 40 CFR 52.21, as incorporated by reference in Rule 3.24. Section 300 identifies the 

requirements necessary to administer the program, including the requirement to obtain a PSD 

permit prior to beginning actual construction of a major stationary source or a major modification. 

Section 400 contains the public participation requirements for issuing a PSD permit.

5. Rule Evaluations

We reviewed the SIP submittals for each rule to ensure that they meet the requirements of title I of 

the Act, specifically part C (sections 160 through 169B), and current implementing regulations at 

40 CFR 51.166. EPA has condensed the approval criteria contained in these various materials in 

this TSD, which describes the basis for our proposed action on the rule submittals.

The Act requires all states to submit a PSD program consistent with the requirements of 40 CFR 

51.166. EPA’s detailed evaluation of these rules and how they meet the requirements for a PSD 

program are included in the attached documents: Evaluation of 40 CFR 51.166 and Rule 210.4 for 

the Eastern Kern County APCD (Eastern Kern Evaluation), and Evaluation of 40 CFR 51.166 and 

Rule 904 for the Imperial County APCD, Rule 518 for the Placer County APCD, and Rule 3.24 for 

the Yolo-Solano AQMD (Imperial, Placer, and Yolo-Solano Evaluation) (see Attachments 3 and 

4). In general, these rules meet the requirements of 40 CFR 51.166 by incorporating by reference 
Page 7 of 25

the specific provisions of 40 CFR 52.21 that are necessary to implement a state PSD program. As 

mentioned above, 40 CFR 52.21 contains the FIP used by EPA to implement the required PSD 

program in areas that do not have a SIP-approved PSD program. EPA considers the provisions of 

40 CFR 52.21 to generally be consistent with the requirements of 40 CFR 51.166. Therefore, only 

those provisions of each rule that warrants additional review and discussion are discussed below. 

5.1. Eastern Kern Rule 210.4 – Prevention of Significant Deterioration

5.1.1. Background

On December 30, 2002, EPA published a final rulemaking action to provide additional flexibility 

in the permitting of modified sources subject to the federal major source NSR and PSD programs. 

To implement these changes revisions were made to 40 CFR 51.165, 40 CFR 51.166 and 40 CFR 

52.21 and are generally referred to as the “NSR Reforms” (see 67 FR 80186). EPA’s intent was to 

allow existing sources additional flexibility in the NSR/PSD permitting process that would 

encourage facilities to make process improvements or undertake energy efficiency projects that 

would provide additional environmental benefits by reducing emissions on a capacity basis. These 

provisions all pertain to how emission increases from proposed modifications of existing sources 

are calculated. 

In 2003, the California Legislature passed Senate Bill 288, Protect California Air Act of 2003 (SB 

288). SB 288 is intended to prevent local air district programs from implementing the NSR 

Reforms. The bill prohibits a district from adopting changes to a district’s NSR rule or PSD 

program that are considered, by California, to be less stringent than such a program was on 

December 30, 2002. Eastern Kern’s previous version of Rule 210.4 was amended and submitted to 

EPA for inclusion in the SIP in 1999. Although Rule 210.4 was never approved by EPA into the 

SIP, it was submitted for approval and, thus, according to ARB, must comply with SB 288. It is not 

EPA’s interpretation that the District must comply with SB 288, which is a matter of state law, in 

order for EPA to approve EKAPCD’s PSD program. 

We note that because of existing local NSR rule requirements in EKAPCD, it is generally unlikely 

that sources located within the District would be subject to different control requirements even if 

EKAPCD were able to adopt the NSR Reforms. With a few exceptions, EKAPCD’s current local 

NSR rule requires BACT for each modification to an emissions unit that results in an emissions 

increase (EKAPCD Rule 210.1). This rule has been submitted to EPA for approval into the SIP but 

EPA has not yet taken action on it. However, because of SB 288, it is unlikely the District could 

remove this requirement from its rules.

As required by 40 CFR 51.166(a)(7)(iv), Eastern Kern’s Final Staff Report for Rule 210.4 contains 

a demonstration that the applicability provisions and definitions of Rule 210.4 are at least as 

stringent as those found in 40 CFR 51.166. 

As discussed in the Final Staff Report, the NSR Reforms made five major changes to 40 CFR 

51.166 and 40 CFR 52.21:
Page 8 of 25

1. Allowing a 10-year look-back for establishing emissions baseline (or 5 years for electric 

steam generating units)

2. Revised calculation methods for emissions increases – allowing an actual-to-projected 

actual test in addition to the actual-to-potential test and providing that a project must cause 

a significant emissions increase in addition to a significant net emissions increase

3. Allowing Actuals Plantwide Applicability Limits (PALs)

4. Pollution Control and Prevention Projects

5. Clean Unit Provisions

The last two features of the 2002 NSR Reforms described above were vacated by the U.S. Court of 

Appeals for the District of Columbia in State of New York, et al., v. U.S. Environmental Protection 

Agency, et al., 413 F.3d 3 (D.C. Cir. 2005), and are no longer a part of the PSD program. 

5.1.2. Eastern Kern APCD Approach to the PSD Program

To comply with SB 288, the District incorporated 40 CFR 52.21 by reference into Rule 210.4 and 

then included additional language in Rule 210.4 that revises the applicability provisions 

incorporated by reference from 40 CFR 52.21(a)(2) and the definitions of major modification, 

baseline actual emissions, actual emissions, and net emissions increase incorporated by reference 

from 40 CFR 52.21(b). EKAPCD Rule 210.4 also excludes the actuals PALs provisions contained 

in 40 CFR 52.21(aa). Rule 210.4 also differs from 40 CFR 52.21 in other respects not directly 

related to SB 288 or the NSR Reforms, as explained below. 

We have considered the specific provisions of EKAPCD’s PSD rule that differ from the federal 

PSD rules in order to ensure that, with these differences, the rule is at least as stringent as the 

requirements of the Federal PSD program. Below, we provide our analysis that Rule 210.4 is at 

least as stringent, in all respects, as the requirements of 40 CFR 51.166 for a PSD program.

5.1.3. Exclusions

Section IV.B of Rule 3.24 excludes the following paragraphs from its incorporation by reference 

of 40 CFR 52.21: 

• (a)(1) – Plan disapproval

• (b)(55-58) and (cc) – equipment replacement program (ERP) provisions which were 

vacated by the United States Circuit Court of Appeals for the District of Columbia on 

March 17, 2006

• (g) – Redesignation

• (i)(1)(i-v, ix-x) and (i)(6-8) – Exemptions

• (p)(6-8) – Class I variances by the Governor

• (q) – Public participation

• (s) – Environmental impact statements

• (t) – Disputed permits or redesignations

• (u) – Delegation of authority

• (v) – Innovative control technology
Page 9 of 25

• (w) – Permit rescission

• (aa) – Actuals PALs

• (f), (x), (y), and (z) – “[Reserved]” 

EPA has reviewed these exclusions and, except for paragraph (q) – Public participation, concurs 

that these excluded paragraphs are not necessary to implement a state PSD program. A 

SIP-approved PSD program is required to include certain public participation requirements found 

in 40 CFR 51.166(q). In lieu of the public participation requirements found in 40 CFR 52.21(q),

Eastern Kern has specified the applicable requirements in Section VII of Rule 210.4. The public 

participation requirements are further discussed in Section 5.1.5 of this TSD.

Also, see Section 5.1.6 for an additional discussion of the rule’s exclusion of actuals PALs.

5.1.4. Applicability Provisions

Pursuant to 40 CFR 51.166(a)(7)(iv), each PSD program must use the specific provisions of 

paragraphs (a)(7)(iv)(a) through (f) of 40 CFR 51.166 for determining whether a project is a major 

modification and subject to the PSD program. Analogous provisions are contained in the FIP at 40 

CFR 52.21(a)(2). Deviations from these provisions will be approved only if a State specifically 

demonstrates that the submitted provisions are more stringent than, or at least as stringent, in all 

respects as the corresponding provisions in paragraphs (a)(7)(iv)(a) through (f) of 40 CFR 51.166. 

See 40 CFR 51.166(a)(7)(iv). Although Rule 210.4 incorporates 40 CFR 52.21 by reference, 

Section III of Rule 210.4 replaces some of the applicability provisions, and references to them, 

with a different set of provisions. These resulting provisions only affect how the PSD program 

applies to modifications of existing emission units. We have determined that all other applicability 

provisions are the same as those in 40 CFR 51.166(a)(7).

5.1.4.1. Major Modification Applicability Provisions in 40 CFR 51.166

The applicability provisions of 40 CFR 51.166(a)(7)(iv)(a) through (f) relate to determining 

whether a project at an existing major stationary source is considered a major modification. These

applicability provisions do this using a two-step process. The first step is to determine whether any 

of the emissions increases associated with the project are considered a “significant emissions 

increase”, as that term is defined in 40 CFR 51.166(b)(39). A significant emissions increase is 

calculated based on the type of unit being modified: (1) for projects that involve existing emission 

units, an actual-to-projected-actual applicability test is used; (2) for modifications that involve 

construction of new emissions units, an actual-to-potential applicability test is used; and (3) for 

projects that involve both existing emission units and construction of new emissions units, a hybrid 

test is used, using the tests specified above for new or existing emission units, as applicable. If the 

project does not cause a significant emissions increase, then the project does not result in a major 

modification.

If the project results in a significant emissions increase, then the second step applies and it must be 

determined whether the project also results in a “significant” “net emissions increase”, as those 
Page 10 of 25

two terms are defined in 40 CFR 51.166(b). A project results in a major modification only if it 

causes both a significant emissions increase and a significant net emissions increase.

5.1.4.2. Major Modification Applicability Provisions in Rule 210.4

The major modification applicability provisions in Section III of Rule 210.4 vary from those 

described above because the provisions do not require that the particular project cause a significant 

emissions increase in order to be considered a major modification or require that a particular “test” 

be used for calculating emission changes. Instead, projects that meet Rule 210.4’s definition of 

major modification are subject to the requirements of Rule 210.4.

Rule 210.4’s definition for “major modification” governs the rule’s applicability provisions 

because it defines a major modification as a modification that results in a “significant” “net 

emissions increase”, as those terms are defined in Section II.F of Rule 210.4. This is different from 

the two-step process in 40 CFR 51.166(a)(7)(iv) because it uses only the second step. That is, a 

project does not have to first cause a significant emissions increase in order to be a major 

modification. For each project, an owner or operator must determine whether the project will result 

in a “significant” “net emissions increase” looking at the entire stationary source, regardless of 

whether the project itself causes emission increases above or below the “significant” thresholds. 

We find this difference acceptable and at least as stringent in all respects as the two-step process in 

40 CFR 51.166(a)(7)(iv).

The other substantive difference in Rule 210.4’s applicability procedures, as compared with the 

procedures in 40 CFR 51.166, is how emission increases from a modified emissions unit are 

calculated. 40 CFR 51.166 requires an actual-to-projected actual “test’ for modifications to 

existing equipment. As part of this test, “projected actual emissions”, as defined in 40 CFR 

51.166(b)(40), are the emission increases above the baseline that are calculated to reflect expected 

normal operating conditions (such as consideration of historical operational data, the company’s 

own representations, the company’s highest projections of expected business activity, or emissions 

the modified unit could have accommodated that are unrelated to the project, see 40 CFR 

51.166(b)(40)(ii)). In lieu of projecting actual emissions, 40 CFR 51.166(b)(40)(ii)(d) also allows 

emission increases to be calculated using the new PTE of the unit, which is the same as using the 

actual-to-potential test required for new units in 40 CFR 51.166(a)(7)(iv).

Rule 210.4 calculates emission increases using the definition of “net emissions increase”. This 

definition does not specifically reference the “actual-to-potential” test, but we have determined 

that the rule’s applicability procedures along with its definitions of major modification, actual 

emissions, and net emissions increase results in a calculation method that is the same as the 

“actual-to-potential” test; that is, emission increases are always based on the PTE of the new or 

modified emissions unit. The EKAPCD also confirmed this in the Final Staff Report for Rule 

210.4 (see Final Staff Report at page D-2, Calculating Emission Increases). This method is 

consistent with what is already required for new emissions units under 40 CFR 51.166(a)(7)(iv) 

and specifically allowed for existing units in the definition for projected actual emissions. We find 

these procedures acceptable and at least as stringent, in all respects as the applicability provisions 

of 40 CFR 51.166(a)(7)(iv) for modifications. 
Page 11 of 25

The definitions of major modification, actual emissions, baseline actual emissions, and net 

emissions increase are discussed in more detail below in Section 5.1.5 of this TSD. 

5.1.4.2.1. Treatment of Fugitive Emissions for Major Modifications

The applicability provisions in Section III of Rule 210.4 and the definition of major modification 

in Section II of Rule 210.4 state that fugitive emissions are not included in determining whether a 

stationary source or modification are considered major, unless the source belongs to one of the 

sources categories listed in 40 CFR 52.21(b)(1)(iii). This requirement is consistent with the 

exemption provided in 40 CFR 51.166(i)(1)(ii) which provides an exemption from the PSD 

program requirements if the source or modification would be a major stationary source or major 

modification only if fugitive emissions are considered in the potential to emit of the source or 

modification. We find this acceptable because Rule 210.4 only determines whether a stationary 

source or modification is major using the potential to emit of the new or modified source, whereas 

40 CFR 51.166(a)(7) allows modified units to use projected actual emissions.

5.1.4.3. Conclusion

Overall, the applicability procedures of Rule 210.4 for major modifications are at least as stringent 

in all respects as those in 40 CFR 51.166(a)(7)(iv) because (1) they do not require that a particular 

project cause a significant emissions increase in order to be a major modification, (2) emission 

calculations are based on the “actual-to-potential” test regardless of whether the modification is for 

new or existing units, and (3) the treatment of fugitive emissions is consistent with the exemption 

provided in 40 CFR 51.166(i)(1)(ii). Based on our analysis, we find the applicability provisions in 

Rule 210.4 to be acceptable and at least as stringent, in all respects, as the requirements of 40 CFR 

51.166(a)(7)(iv).

5.1.5. Revised Definitions and Terms

Pursuant to 40 CFR 51.166(b), PSD programs must use the definitions provided in 40 CFR 

51.166(b). Deviations from the wording are to be approved only if the State demonstrates that the 

submitted definition is more stringent, or at least as stringent, in all respects as the corresponding 

definitions in 40 CFR 51.166(b). Section II of Rule 210.4 revises some of the definitions and terms

incorporated by reference in 40 CFR Part 52.21(b). We discuss our analysis of these provisions 

below.

5.1.5.1. Actual Emissions

Section II.A of Rule 210.4 revises the definition of “actual emissions” in 40 CFR 52.21(b)(21). 

This definition is nearly identical to the definition found in 40 CFR 51.166(b)(21). However, it 

does not contain the following exclusion that appears in 40 CFR 51.166(b)(21)(i): 

“...except that this definition shall not apply for calculating whether a significant 

emissions increase has occurred, or for establishing a PAL under paragraph (aa) of this 
Page 12 of 25

section. Instead paragraphs (b)(41) and (b)(48) of this section shall apply for those 

purposes.”

This exclusion from Rule 210.4’s definition is acceptable because Rule 210.4 does not use the 

significant emissions increase calculation and, as noted above, it does not allow the use of PALs. 

We find this revision to be acceptable and at least as stringent, in all respects, as the definition in 40 

CFR 51.166(b)(21). 

5.1.5.2. Administrator

Section II.B of Rule 210.4 defines the term “administrator” in Rule 210.4 as follows:

• It defines the term “administrator” to mean “Federal Administrator” in 40 CFR 

52.21(b)(17), (b)(37)(i), (b)(43), b(48)(ii)(c), (b)(50)(i), (b)(51), (l)(2), and (p)(2).

• It otherwise defines the term “administrator” to mean “APCO”, which is a defined term 

in Rule 210.4.

Because 40 CFR 52.21 was written to provide a framework for EPA to administer the PSD 

program in areas that do not have a SIP-approved PSD program, the term “Administrator” as used 

in section 52.21 refers to the EPA Administrator. Upon EPA’s approval of Eastern Kern’s PSD 

SIP submittal, the EKAPCD will be administering the PSD program within the District, but certain 

authorities are retained for the EPA Administrator, per 40 CFR 51.166. Therefore, the District’s 

revisions described above are intended to differentiate between those provisions that will apply to 

the District as the permitting authority that will administer the PSD program and those that will 

continue to refer to EPA (as the “Federal administrator”). We find these revisions acceptable.

5.1.5.3. APCO

Section II.C of Rule 210.4 defines APCO as the “Air Pollution Control Officer of the Eastern Kern 

Air Pollution Control District”. We find the addition of this definition acceptable. 

5.1.5.4. Baseline Actual Emissions

Section II.D of Rule 210.4 revises the definition of “baseline actual emissions” in 40 CFR 

52.21(b)(48), as incorporated by reference into Rule 210.4, to read as follows:

1. Baseline Actual Emissions means the actual rate of emissions of a pollutant from an 

emission unit, as determined in accordance with Sections II.E.2 and II.E.3 below. 

2. In general, Baseline Actual Emissions as of a particular date shall equal the average rate, 

in tons per year, at which the unit actually emitted the pollutant during a two-year period 

which precedes the particular date and which is representative of normal source 

operation. The Administrator shall allow the use of a different time period upon a 

determination that it is more representative of normal source operation. Baseline Actual 
Page 13 of 25

Emissions shall be calculated using the unit’s actual operating hours, production rates, 

and types of materials processed, stored or combusted during the selected time period. 

3. For any emissions unit which has not begun normal operations on the particular date, 

Baseline Actual Emissions shall equal the potential to emit of the unit.

The term “baseline actual emissions” is used in 40 CFR 51.166 to determine applicability of the 

PSD program. As a result, the term is associated with determining net emissions increases, 

projected actual emissions, reasonable possibility, and PALs. However, Rule 210.4 only uses the 

term “baseline actual emissions” for determining “reasonable possibility” under 40 CFR 

52.21(r)(6). 

The definition for baseline actual emissions in 40 CFR 51.166(b)(47) generally provides greater 

flexibility than the definition used in Rule 210.4. For example, in 40 CFR 51.166(b)(47), the 

owner/operator may choose any consecutive 24-month period within a 10 year period (or 5 years 

for electric steam generating units) to determine the average emission rate for each regulated NSR 

pollutant. Rule 210.4’s definition calculates the average emission rate based on the specific 2-year 

period which precedes a particular date. However, both definitions allow a different time period to 

be used upon a determination that it is more representative of normal operation. 

The definition in 40 CFR 51.166(b)(47) also describes how to treat fugitive emissions, 

non-compliant emissions, and emissions associated with startups, shutdowns, and malfunctions; 

the ability to use a different two year look back period for each pollutant; and, the need to use a two 

year period that the owner or operator has adequate information for determining annual emissions. 

While this information is not specifically included in Rule 210.4 we believe it is at least as 

stringent as 40 CFR 51.166 because of Rule 210.4’s requirement to use a 2-year period that is 

representative of normal source operation.

Overall, both definitions require a source to determine the average emission rate, in tons per year, 

during a two-year period prior to the project, which is representative of normal operations and is 

based on the rate at which a unit actually emitted a pollutant. As a result, the definition of “baseline 

actual emissions” in Rule 210.4 is at least as stringent, in all respects, as the definition in 40 CFR 

51.166(b)(48).

We note that Section II.D.1 appears to have a typographical error that references Section II.E.2 and 

II.E.3 instead of the two provisions that immediately follow – II.D.2 and II.D.3. We find this to be 

a minor oversight and recommend the District correct this error the next time the rule is open for 

revision.

5.1.5.5. Major Modification

Section II.E of Rule 210.4 revises the definition of “major modification” in 40 CFR 52.21(b)(2).

The definition for “major modification” in Rule 210.4 is different from the definition in 40 CFR 

51.166(b)(2) in that it is consistent with the applicability procedures found Section III of Rule 

210.4 and discussed above in Section 5.1.2 of this TSD. In other words, any project that causes a 
Page 14 of 25

“significant” “net emissions increase” is considered a major modification. The project itself does 

not have to first cause a significant emissions increase in order to trigger an evaluation of whether

it causes a significant net emissions increase. As noted above, we find the applicability procedures 

of Rule 210.4 to be acceptable and at least as stringent, in all respects, as the Federal applicability 

procedures. By the same reasoning, we find that Rule 210.4’s definition of “major modification,” 

which is consistent with the applicability procedures in Rule 210.4, is acceptable and is at least as 

stringent, in all respects, as the definition in 40 CFR 51.166(b)(2).

5.1.5.6. Net Emission Increase

Section II.F of Rule 210.4 revises the definition of “net emission increase” in 40 CFR 52.21(b)(3). 

The definition is revised such that the net emissions increase from a project is the sum of any 

increases in “actual emissions”, as that term is defined in Section II.A of Rule 210.4, from a 

particular project and any other increases and decreases in actual emissions at the source that are 

contemporaneous with the particular change and are otherwise creditable. This is consistent with 

the definition in 40 CFR 51.166(b)(3), except that it does not reference the applicability 

procedures found in 40 CFR 51.166(a)(7)(iv) for calculating the emission changes. The result is 

the use of the actual-to-potential test previously described and found acceptable for determining 

the applicability of the PSD program to major modifications in this TSD in Section 5.1.2. 

Section II.F.6.b of Rule 210.4 uses the phrase “federally enforceable” instead of the phrase 

“enforceable as a practical matter” found in 40 CFR 51.166(b)(3)(vi)(b). We consider anything 

that is federally enforceable to also be enforceable as a practical matter. 

In addition Rule 210.4 also contains the statement: “With respect to particulate matter, only PM10

emissions can be used to evaluate the net emissions increase for PM10.” This clarification that only 

PM10 emissions can be used to evaluate the net emissions increase for PM10 provides additional 

specificity to the definition that we find acceptable.

Based on our review of Rule 210.4’s definition of “net emission increase”, we find the definition to 

be at least as stringent, in all respects, as the definition of “net emission increase” in 40 CFR 

51.166(b)(3).

5.1.6. Actuals PALs

The actuals PALs provisions in 40 CFR 51.166(w) and 40 CFR 51.166(aa) allow a facility to 

establish a facility-wide emissions cap for a specific pollutant. Once the PAL is determined, a 

facility can make any physical modification or change in the method of operation, which might 

otherwise trigger a major modification, without obtaining a PSD permit, as long as the actual 

plantwide emissions remain below the PAL level.

Rule 210.4 does not adopt the actuals PALs provisions, so sources located within the District will 

not have access to the flexibilities described above. However, as explained in Section 5.1.1, 

because of other local rules the advantages of actuals PALs, which were a part of the NSR 
Page 15 of 25

Reforms, are already likely not available to sources within the District. We find this difference 

acceptable.

5.1.7. References to 40 CFR 52.21(q)

Sections G of Rule 210.4 revises the phrase “paragraph (q) of this section” in paragraph (p)(1) of

40 CFR 52.21, as incorporated by reference into Rule 210.4, to read as:

“within ten calendar days following a preliminary decision pursuant to Section IV, 

Requirements of this rule, the APCO shall publish in at least one newspaper of general 

circulation in the District a notice stating the preliminary decision of the APCO, noting 

how pertinent information can be obtained, and inviting written public comment for a 

30-day period following the date of publication. The notice shall include the time and place 

of any hearing that may be held including a statement of procedure to request a hearing 

(unless a hearing has already been scheduled). The APCO shall give notice of any public 

hearing at least 30 days in advance of the hearing.” 

A revision to this paragraph was necessary because the District excluded paragraph (q) from its 

incorporation by reference of 40 CFR 52.21. We note that “paragraph (q) of this section” also 

appears in paragraph (l)(2) of 40 CFR 52.21. This appears to be a minor oversight and we 

recommend the District revise Section II.G to include a reference to (l)(2) the next time Rule 210.4 

is open for revision. 

It is not clear why this provision details the notice and comment procedures in lieu of a general 

reference to these requirements in Section VII of Rule 210.4. However, we consider this to also be 

a minor oversight and recommend that the District revise the phrase “paragraph (q) of this section” 

to “Section VII of this Rule” the next time the rule is open for revisions.

5.1.8. Application Completeness and Public Participation

EPA’s Eastern Kern Evaluation demonstrates how Eastern Kern’s PSD program meets the 

requirements of 40 CFR 51.166(q) for public participation and application processing procedures

(see Attachment 3). The District meets these requirements through Rule 210.4 and existing 

SIP-approved Rule 210.1. Rule 210.4 meets the public participation requirements specified in 40 

CFR 51.166(q)(1)(i) through (vii) and Rule 210.1 meets the other application processing 

procedures of paragraph (q) related to application completeness.

5.1.9. Additional Requirements

Rule 210.4 includes additional requirements beyond those specifically included in 40 CFR 52.21 

that the District finds necessary to administer the PSD program. These requirements include: 

• An owner operator must obtain a PSD permit pursuant to Rule 210.4 prior to beginning 

actual construction of a new major stationary source or a major modification, as 

defined in 40 CFR 52.21(b); 
Page 16 of 25

• The APCO shall require compliance with Rule 210.4 prior to issuing a PSD permit; 

• Applicants shall pay the applicable fees specified in District Regulation II; and

• Greenhouse gas emissions shall not be subject to the requirements of subsections (k) or 

(m) of 40 CFR 52.21.

EPA has reviewed these provisions and determined they are acceptable and consistent with the 

requirements of 40 CFR 51.166.

5.1.10. Notice to EPA

40 CFR 51.166(p)(1) requires the reviewing authority to provide notice to the EPA of every action 

related to the consideration of a PSD permit:

Notice to EPA. The plan shall provide that the reviewing authority shall transmit to the 

Administrator a copy of each permit application relating to a major stationary source or 

major modification and provide notice to the Administrator of every action related to the 

consideration of such permit. 

In a letter dated July 19, 2012, Eastern Kern confirmed that:

“...Section VII of Rule 210.4 instructs the District to, “make available in at least one 

location in each region in which the proposed source would be constructed a copy of all 

materials the applicant submitted, a copy of the preliminary determination, a copy of the 

proposed permit, and a copy of summary of other materials, if any, considered in making 

the preliminary determination”. Section VII of Rule 210.4 goes on to explain the public 

notification process and directs the District to send a copy of the public notice to the 

applicant and EPA. Although the intent of the section may not be clear the District 

interprets it to mean provide copies of all PSD documents to the applicant and EPA.”

Additionally, the District believes Sections V.A.3 and V.A.6 of District Rule 210.1 gives greater 

detail to the requirement to provide EPA with a copy of each permit application related to each 

new major stationary source or major modification. To aid in clarity, staff intends to update Rule 

210.4 with similar language the next time it is open for revisions. 

Based on the District’s clarification concerning its interpretation of Rule 210.4 we find that the 

requirements of paragraph (p)(1) have been met. 

5.1.11. Revisions to 40 CFR 52.21 After Incorporation by Reference by EKAPCD

Rule 210.4 incorporates 40 CFR 52.21 by reference as in effect on January 12, 2012. As a result, 

revisions made to 40 CFR 52.21, and not in effect until after January 12, 2012, are not a part of 

Rule 210.4. On July 12, 2012, revisions related to PALs for GHG emissions language in 40 CFR 

52.21 were published in the Federal Register and became effective on August 13, 2012. The 
Page 17 of 25

revisions are intended to improve the usefulness of PALs for GHG emissions. However, these 

provisions were not included in 40 CFR 51.166, so they do not need to be included in Eastern Kern 

Rule 210.4. Therefore, although Rule 210.4 does not include these new provisions, this difference

does not affect the approvability of the rule.

We note that Rule 210.4 clearly states at the beginning of the rule that the rule was most recently 

adopted and amended on January 12, 2012. However when incorporating 40 CFR 52.21 by 

reference, Section IV.A states:

“Excepts as provided in Section V.B, below, the provisions of 40 CFR 52.21, in effect (date of 

adoption), are incorporated herein by reference and made part of the Rules and Regulations of the 

District. All references to 40 CFR 52.21 in this rule refer to the 40 CFR 52.21 in effect on (date of 

adoption)”

We interpret this language to refer to the January 12, 2012 adoption date for incorporating 40 CFR 

52.21 by reference. Additionally, in a letter dated July 19, 2012, the EKAPCD confirmed that the 

parenthetical reference to “date of adoption” should have been replaced with the actual date the 

rule was adopted. That is, the draft version of the rule was not properly updated upon board 

adoption. This error also appears in Section II of the rule. Because the rule clearly identifies the 

date of adoption we find this oversight acceptable and it does not affect our approvability of this 

rule.

5.2. Imperial Rule 904, Placer Rule 518, and Yolo-Solano Rule 3.24 for Prevention of 

Significant Deterioration

The PSD rules submitted for ICAPCD (Rule 904), PCAPCD (Rule 518), and YSAQMD (Rule 

3.24) are very similar, so we have aggregated the majority of our analysis of these rules below. 

5.2.1. Exclusions

Section C.1 of Imperial Rule 904, Section 103 of Placer Rule 518, and Section 104 of Yolo-Solano 

Rule 3.24 exclude the following paragraphs from their incorporation by reference of 40 CFR 

52.21: 

Table 1 Exclusions from Provisions of 40 CFR 52.21 Incorporated by Reference

Imperial Rule 908 Placer Rule 518 Yolo-Solano Rule 3.24

· (a)(1) – Plan disapproval · (a)(1) – Plan disapproval · (a)(1) – Plan disapproval

· (b)(55-58) and (cc) · (b)(55-58) and (cc) · (b)(55-58) and (cc)

· (g) – Redesignation · (g) – Redesignation · (g) – Redesignation

· (p)(6-8) – Class I variances by 

the Governor

· (p)(6-8) – Class I variances by 

the Governor

· (i)(1)(i-v, ix-x) and (i)(6-8) –

Exemptions

· (q) – Public participation · (q) – Public participation · (k)(2) - PM2.5 SILs

· (s) – Environmental impact 

statements

· (s) – Environmental impact 

statements

· (p)(6-8) – Class I variances by 

the Governor
Page 18 of 25

Imperial Rule 908 Placer Rule 518 Yolo-Solano Rule 3.24

· (t) – Disputed permits or 

redesignations

· (t) – Disputed permits or 

redesignations · (q) – Public participation

· (u) – Delegation of authority · (u) – Delegation of authority · (s) – Environmental impact 

statements

· (v) – Innovative control 

technology

· (v) – Innovative control 

technology

· (t) – Disputed permits or 

redesignations

· (w) – Permit rescission · (w) – Permit rescission · (u) – Delegation of authority

· (f), (x), (y), and (z) –

“[Reserved]” 

· (f), (x), (y), and (z) –

“[Reserved]” 

· (v) – Innovative control 

technology

· (w) – Permit rescission

· (f), (x), (y), and (z) –

“[Reserved]” 

EPA has reviewed these exclusions and, except for paragraph (q), concurs that these excluded 

paragraphs are not necessary to implement a state PSD program.

A SIP-approved PSD program is required to include certain public participation requirements 

found in 40 CFR 51.166(q). In lieu of the public participation requirements found in 40 CFR 

52.21(q), the Districts specified the applicable public participation requirements in Section F of 

Imperial Rule 904, Section 401 of Placer Rule 518, and Section 402 of Yolo-Solano Rule 3.24. 

These public participation requirements are further discussed in Section 5.2.4 of this TSD.

5.2.2. Revised Definitions and Terms

5.2.2.1. Definitions in 40 CFR 52.21(b)

Sections D.1 and D.2 of Imperial Rule 904, and Sections 202 and 204 of Placer Rule 518, revise

the definitions incorporated by reference from 40 CFR Part 52.21(b), such that:

• In the definition of “potential to emit” in 40 CFR 52.21(b)(4), the phrase “is federally 

enforceable” instead reads “is federally enforceable or enforceable as a practical 

matter”.

• In the definition of “allowable emissions” in 40 CFR 52.21(b)(16), the language 

reading “unless the source is subject to federally enforceable limits which restrict the 

operating rate, or hours of operation, or both” instead reads “unless the source is 

subject to enforceable limits which restrict the operation rate, or hours of operation, or 

both”.

• Paragraph (iii) of the definition of “allowable emissions” in 40 CFR 52.21(b)(16)

reads: “The emissions rate specified as an enforceable permit condition, including 

those with a future compliance date.”
Page 19 of 25

SIP-approved PSD programs must use the definitions provided in 40 CFR 51.166(b), except that 

deviations are approvable if demonstrated to be more stringent, or at least as stringent, as the 

definition provided. The revisions made by the District to the definitions described above further 

clarify “federally enforceable”. We find these revisions to be acceptable and at least as stringent as 

the definitions in 40 CFR 51.166(b).

5.2.2.2. Administrator

Section D.3 of Imperial Rule 904, Section 201 of Placer Rule 518, and Section 201 of Yolo-Solano 

Rule 3.24 revise the term “administrator” incorporated by reference from 40 CFR 52.21, such that:

• It defines the term “administrator” to mean “Federal administrator” in 40 CFR 

52.21(b)(17), (b)(37)(i), (b)(43), (b)(48)(ii)(c), (b)(50)(i), (b)(51), (l)(2), and (p)(2).

• It otherwise defines the term “administrator” to mean “Air Pollution Control Officer 

(APCO)”.

Because 40 CFR 52.21 was written to provide a framework for EPA to administer the PSD 

program in areas that do not have a SIP-approved PSD program, the term “Administrator” as used 

in section 52.21 refers to the EPA Administrator. Upon EPA’s approval of these PSD SIP 

submittals, each District will be administering the PSD program within the District, but certain 

authorities are retained for the EPA Administrator, per 40 CFR 51.166. Therefore, the revisions 

described above are intended to differentiate between those provisions that will apply to the 

District as the entity that will administer the PSD program and those that will continue to refer to 

EPA (as the “Federal administrator”). We find these revisions acceptable.

We note that Section D of Imperial Rule 904, Section 200 of Placer Rule 518, and Section 200 of 

Yolo-Solano Rule 3.24 refer only to paragraph (b) of 40 CFR 52.21 when revising terms and 

definitions in 40 CFR 52.21. However, the term “administrator” appears in places other than 

paragraph (b) and each rule goes on to specifically identify each of those citations. This appears to 

be a minor typographical error and we recommend that the Districts remove this reference to 

paragraph (b) the next time each rule is revised.

5.2.2.3. References to 40 CFR 52.21(q)

Section D.3.b of Imperial Rule 904, Section 203 of Placer Rule 518, and Section 202 of 

Yolo-Solano Rule 3.24 revise references in 40 CFR 52.21 to “paragraph (q) of this section”, which 

are the public notice procedures in 40 CFR 52.21. These revisions are necessary because each rule 

excludes paragraph (q) from its incorporation by reference of 40 CFR 52.21. Each rule is revised to 

reference the public notice procedures used by each District. We note that Section D.3.b of 

Imperial Rule 904 should have included (p)(1) and (l)(2) when making this revision, and Section 

203 of Placer Rule 518 should have included (l)(2) when making this revision. These appear to be 

minor typographical errors and we recommend the Districts revise these sections the next time 

each rule is revised.
Page 20 of 25

5.2.3. Additional Requirements

Section E of Imperial Rule 904, Section 301 of Placer Rule 518, and Sections 301 and 401 of 

Yolo-Solano Rule 3.24 include additional requirements beyond those specifically included in 40 

CFR 52.21 that the Districts find necessary to administer the PSD program. These requirements 

include: 

• PSD permits shall be issued pursuant to each PSD Rule prior to beginning actual 

construction of a new major stationary source, a major modification, or a plant wide 

applicability limitation (PAL) major modification, as defined in 40 CFR 52.21(b); 

• The air pollution control officer shall require compliance with each PSD rule prior to 

issuing a PSD permit; 

• Applicants shall pay the applicable fees specified in Imperial Rule 301, Placer Rule 

601, and Yolo-Solano Rule 4.1.

• GHG emissions are exempt from paragraphs (k) and (m) of 40 CFR 52.21.

EPA has reviewed these requirements and determined they are acceptable and consistent with the 

requirements of 40 CFR 40 CFR 51.166.

5.2.4. Application Completeness and Public Participation

EPA’s Imperial, Placer and Yolo-Solano Evaluation demonstrates how each district meets the 

requirements of 40 CFR 51.166(q) for public participation and application processing procedures

(see Attachment 4). ICAPCD meets these requirements through Section F of Imperial Rule 904 

and Sections A.2 and C.4 of existing SIP-approved Imperial Rule 206. PCAPCD meets these 

requirements through Section 401 of Placer Rule 518 and Sections 402 and 404.1 of existing 

SIP-approved Placer Rule 502. YSAQMD meets these requirements through Section 400 of 

Yolo-Solano Rule 3.24. 

5.2.5. Notice to EPA– 40 CFR 51.166(p)(1)

40 CFR 51.166(p)(1) requires the reviewing authority to provide notice to the EPA of every action 

related to the consideration of a PSD permit:

Notice to EPA. The plan shall provide that the reviewing authority shall transmit to the 

Administrator a copy of each permit application relating to a major stationary source or 

major modification and provide notice to the Administrator of every action related to the 

consideration of such permit. 

Each district confirmed this requirement is addressed to a certain extent by its incorporation by 

reference of 40 CFR 52.21(p)(2) and offered further clarification confirming that the requirement 

would be met:
Page 21 of 25

• In a letter dated July 16, 2012, PCAPCD confirmed that this requirement is met to a certain 

extent by Section F of Placer Rule 518 and is already required by Section 407 of existing 

SIP-approved Rule 502.

• In a letter dated July 10, 2012, ICAPCD confirmed that Section F of Imperial Rule 904 

meets this requirement to a certain extent and the ICAPCD will ensure EPA is provided 

copies of applications and given notice of each action related to such applications.

• In a letter dated August 7, 2012, YSAQMD confirmed that this requirement is met to a 

certain extent by Section 400 of Rule 3.24 and the YSAQMD will ensure EPA is provided 

copies of applications and given notice of each action related to such applications.

5.2.6. Revisions to 40 CFR 52.21 After Incorporation by Reference by the Districts

5.2.6.1. Imperial Rule 904

Imperial Rule 904 incorporates 40 CFR 52.21 by reference as in effect on December 20, 2011. As 

a result, revisions made to 40 CFR 52.21, and not in effect until after December 20, 2011, are not a 

part of Imperial Rule 904. As noted in Section 5.1.8 above, on July 12, 2012, revisions related to

PALs for GHG emissions language in 40 CFR 52.21 were published in the Federal Register and 

became effective on August 13, 2012. For the reasons discussed in Section 5.1.8, although 

Imperial Rule 904 does not include these new provisions, this difference does not affect the

approvability of the rule.

5.2.6.2. Placer Rule 518

Placer Rule 518 incorporates 40 CFR 52.21 by reference as in effect on February 10, 2011. As a 

result, revisions made to 40 CFR 52.21, and not in effect until after February 10, 2011, are not a 

part of Placer Rule 518. On July 20, 2011, the definition of “subject to regulation” was revised in 

40 CFR 51.166(b)(48)(ii)(a) and 40 CFR 52.21(b)(49)(ii)(a) to exclude the applicability of CO2

emissions from biogenic sources from being considered “subject to regulation” until July 21, 2014. 

Placer Rule 518 does not include this provision. However, because the PCAPCD’s definition is 

more stringent than the revised definition in 40 CFR 51.166, we find this difference acceptable.

In addition, as noted in Section 5.1.8 above, on July 12, 2012, revisions related to PALs for GHG 

emissions language in 40 CFR 52.21 were published in the Federal Register and became effective 

on August 13, 2012. For the reasons discussed in Section 5.1.8, although Placer Rule 518 does not 

include these new provisions, this difference does not affect the approvability of the rule.

5.2.6.3. Yolo-Solano Rule 3.24

Yolo-Solano Rule 3.24 incorporates 40 CFR 52.21 by reference as in effect on June 13, 2012. As a 

result, revisions made to 40 CFR 52.21, and not in effect until after June 13, 2012, are not a part of 

Yolo-Solano Rule 3.24. As noted in Section 5.1.8 above, on July 12, 2012, revisions related to 

PALs for GHG emissions language in 40 CFR 52.21 were published in the Federal Register and 

became effective on August 13, 2012. For the reasons discussed in Section 5.1.8, although 

Yolo-Solano Rule 3.24 does not include these new provisions, this difference does not affect the

approvability of the rule.
Page 22 of 25

We note that Rule 3.24 clearly states that the rule was adopted on June 13, 2012 (at the beginning 

of the rule and on each page of the rule). However when incorporating 40 CFR 52.21 by reference, 

Section 103 states:

“Except as provided in Section 104, the provisions of 40 CFR 52.21, in effect on (date of adoption 

or July 1, 2012 if adopted after that date), are incorporated herein by reference and made part of the 

Rules and Regulations of the Yolo-Solano Air Quality Management District.”

We believe that the rule is clearly referring to the June 13, 2012 adoption date for incorporating 40 

CFR 52.21 by reference. (The reference to Section 104 of the Rule is a reference to revisions made 

the YSAQMD to the incorporated provisions of 40 CFR 52.21, discussed elsewhere in this TSD.) 

In a letter dated August 7, 2012, the YSAQMD confirmed that the parenthetical reference to “date 

of adoption or July 1, 2012 if adopted after that date” should have been replaced with the actual 

date the rule was adopted. This error also appears in Section 200 of the rule. That is, the 

pre-adoption version of the rule was not properly updated upon board adoption. Because the rule 

clearly identifies the date of adoption we find this oversight acceptable and it does not affect our 

approvability of this rule.

5.3. PM2.5 Significant Impact Levels

Eastern Kern Rule 210.4, Imperial Rule 904, and Placer Rule 518 each incorporated by reference 

the PM2.5 significant impact levels (SILs) found in 40 CFR 52.21(k)(2). (Yolo-Solano Rule 3.24 

does not incorporate these PM2.5 SILs, by reference or otherwise.) Consistent with 40 CFR 

51.166(k)(2), the PM2.5 SILs are an optional portion of the PSD permitting program. However, 

EPA's authority to implement the PM2.5 SILs for PSD purposes is currently subject to litigation, 

Sierra Club v. EPA, Case No. 10-1413 (D.C. Circuit). As a result, EPA has come to recognize that 

the regulatory text it adopted in 40 CFR 51.166 (k)(2) and 40 CFR 52.21(k)(2) does not accurately 

reflect EPA's intent, because the text does not afford permitting authorities sufficient discretion to 

deny sources use of the SILs where their use would lead to a new violation of the NAAQS or 

increment. EPA requested in our response brief to the Court in this litigation that the Court remand 

and vacate 40 CFR 51.166(k)(2) and 40 CFR 52.21(k)(2) so that we may initiate a rulemaking to 

make revisions to the regulatory text. 

Specifically, 40 CFR 52.21(k)(2) establishes SILs for PM2.5 and reads as follows:

(k)(2) Significant impact levels. For purposes of PM2.5, the demonstration required in 

paragraph (k)(1) of this section is deemed to have been made if the emissions increase from 

the new stationary source alone or from the modification alone would cause, in all areas, air 

quality impacts less than the following amounts:

Pollutant Averaging time Class I area Class II area Class III area

PM2.5 ................. Annual ............ 0.06 μg/m3 0.3 μg/m3 0.3 μg/m3

24-hour ........... 0.07 μg/m3 1.2 μg/m3 1.2 μg/m3
Page 23 of 25

Paragraph (k)(1) requires that sources applying for a new PSD permit demonstrate that any 

allowable emission increases from the proposed source or modification, in conjunction with all 

other applicable emissions increases or reductions, will not cause or contribute to a violation of 

any NAAQS or any applicable increment. 40 CFR 52.21(k)(1). In the preamble to the 2010 final 

rule adding the (k)(2) provision, EPA advised that, “notwithstanding the existence of a SIL, 

permitting authorities should determine when it may be appropriate to conclude that even a de 

minimis impact will ‘cause or contribute’ to an air quality problem and to seek remedial action 

from the proposed new source or modification.” Prevention of Significant Deterioration (PSD) for 

Particulate Matter Less than 2.5 Micrometers (PM2.5) – Increments, Significant Impact levels 

(SILs) and Significant Monitoring Concentration (SMC), 75 Fed. Reg. 64,864, 64,892 (Oct. 20, 

2010). In another passage of the preamble, EPA also observed that “the use of a SIL may not be 

appropriate when a substantial portion of any NAAQS or increment is known to be consumed.” 

Id. at 64,894. 

In light of the ongoing litigation over the PM2.5 SILs and EPA's request for remand and vacatur of 

the provision at 40 CFR 52.21(k)(2), we requested clarification from EKAPCD, ICAPCD, and 

PCAQMD concerning their interpretation of their respective rules that incorporate by reference 40 

CFR 52.21(k)(2). Consistent with the statements by EPA in the preamble to the 2010 final rule, 

these Districts confirmed that they do not interpret section 52.21(k)(2) to preclude them from 

exercising the discretion to determine when it may be appropriate to conclude that even a de 

minimis impact on air quality (an impact below the PM2.5 SIL values) will cause or contribute to an 

air quality problem and to seek remedial action from the proposed new source or modification (see 

Attachment 5). Based on this interpretation, each of these Districts has clarified that it will not read 

section 52.21(k)(2) as an absolute “safe harbor,” but will exercise discretion to determine whether 

a particular application of the PM2.5 SILs is appropriate when a substantial portion of the PM2.5

NAAQS or increment is known to be consumed. These Districts have also clarified that they retain 

the discretion to require additional information from a permit applicant as needed to assure that the 

source will not cause or contribute to a violation of any NAAQS or applicable increment pursuant 

to paragraph 52.21(k)(1). Based on these clarifications provided by EKAPCD, PCAPCD, and 

ICAPCD, we find their rules are approvable and consistent with the Act and the requirements for a 

PSD program.

6. Program Transfer and Implementation Issues

As discussed in Section 2, EPA requested, among other things, that each District provide further 

confirmation and explanation concerning (1) the District’s authority, personnel, and funding to 

implement the PSD program within the District pursuant to CAA Section 110(a)(2)(E)(i), and (2) 

where applicable, the District’s request to implement the PSD program with respect to existing 

PSD permits issued by EPA. The Districts subsequently provided the requested information (see 

Attachment 2). 

In a July 6, 2012 letter, the PCAPCD confirmed that, as part of, and concurrent with, EPA’s 

approval of the District’s PSD program into the SIP, the District is requesting approval to exercise 

its authority to administer the PSD program with respect to the single source located in the District 

that has an existing PSD permit issued by EPA. This would include authority to conduct general 
Page 24 of 25

administration of this existing permit, authority to process and issue any and all subsequent PSD

permit actions relating to this permit including, for example, modifications, amendments, or 

revisions of any nature, and authority to enforce such permits.

In a July 19, 2012 letter, the EKAPCD confirmed that, as part of, and concurrent with, EPA’s 

approval of the District’s PSD program into the SIP, the District is requesting approval to exercise 

its authority to administer the PSD program with respect to the 6 sources located in the District that 

have an existing PSD permit issued by EPA. This would include authority to conduct general 

administration of these existing permits, authority to process and issue any and all subsequent PSD 

permit actions relating to such permits including, for example, modifications, amendments, or 

revisions of any nature, and authority to enforce such permits.

There are no existing EPA-issued PSD permits in the ICAPCD or the YSAQMD.

Pursuant to section 110(a)(2)(E)(i) of the Act, each District’s SIP submittal and clarification letters 

demonstrate that each District has the authority under State statute and/or rule to administer the 

PSD permit program, including but not limited to the authority to administer, process and issue 

any and all permit decisions, and enforce PSD permit requirements within each District. This 

applies to PSD permits the District will issue and to existing PSD permits issued by EPA that are to 

be transferred upon the effective date of EPA’s approval of the Districts’ PSD SIP submittals.

The Districts’ SIP submittals and clarification letters also demonstrate that the District has 

adequate personnel and funding to administer, implement and enforce the PSD program.

The existing PSD permits issued by EPA for which EPA currently anticipates that responsibility 

would be transferred to the District immediately upon the effective date of an EPA final action 

approving the PSD SIP submittals are identified in Attachment 6 to this TSD. EPA intends to 

provide a copy of these permits to the District prior to the effective date of the final SIP approval.

Upon approval of the Districts’ PSD SIP submittals, EPA will assume an oversight role of the 

Districts’ PSD permitting programs, as intended by the Act.

6.1. PSD Permit Applications Currently Under Review by EPA

In order to promote an orderly transition of the PSD program from the EPA to the Districts, EPA 

believes it is appropriate to transfer upon the effective date of our final SIP approval action for 

each District any pending PSD permit applications for sources within such District that are under 

review by EPA prior to such approval. This would include PSD permit applications that have been 

submitted to EPA, but for which EPA has not yet issued a proposed decision. EPA has been 

working with applicants and the Districts to ensure that the transition process does not result in 

undue project delays and to ensure that such applications are acted upon in a timely manner. 

7. Sections 110(a), 110(l), and 193 of the Act

CAA section 110(a) requires, among other things, that the requirements of SIP rules be

enforceable. Sources subject to Eastern Kern Rule 210.4, Imperial Rule 904, Placer Rule 518, and 
Page 25 of 25

Yolo-Solano Rule 3.24 are required to meet emission limits and other measures for the prevention 

of significant deterioration of air quality, which meets the enforceability requirement in section 

110(a).

We have also evaluated these SIP revisions to determine whether they would interfere with any 

applicable requirement concerning attainment and reasonable further progress (RFP) or any other 

applicable requirement of the Act (CAA section 110(l)) or whether they would modify, in a 

nonattainment area, any SIP-approved control requirement in effect before November 15, 1990 

(CAA section 193).

We find that our approval of the submittals would comply with CAA section 110(l), because the 

SIP, as revised to reflect the submitted revisions, would provide for RFP and attainment of the 

NAAQS, and the requirements of the PSD SIP revisions are essentially equivalent to, and at least 

as stringent as, those of the FIP codified in 40 CFR 52.21 and used to date by EPA to implement 

the required PSD program within these Districts. As described elsewhere in this document, 

approval of these SIP submittals would merely result in the transfer of authority for the PSD 

program from the EPA to the Districts, and therefore would not result in any substantive changes 

to the PSD program requirements, other CAA requirements, or air quality.

Further, section 193 of the CAA does not apply to this proposed action because these submittals to 

incorporate PSD requirements into the SIP do not address nonattainment pollutants. 

8. Recommendations

Pursuant to section 110(k)(3) of the Act, we recommend full approval of Eastern Kern Rule 210.4, 

Imperial Rule 904, Placer Rule 518, and Yolo-Solano Rule 3.24. We recommend approval based 

on our determination that the submittals comply with the applicable statutory and regulatory 

provisions requiring regulation of major stationary sources, in particular, part C of title I of the 

Act. If finalized, our action would be codified through revisions to 40 CFR 52.220 – Identification 

of plan and 40 CFR 52.270 – Significant deterioration of air quality.

9. Attachments

• Attachment 1 – Eastern Kern Rule 210.4, Imperial Rule 904, Placer Rule 518 and 

Yolo-Solano Rule 3.24

• Attachment 2 – Letters received from EKAPCD, ICAPCD, PCAPCD and YSAQMD 

regarding certain clarifications of each district’s PSD permit program

• Attachment 3 – Evaluation of 40 CFR 51.166 and Eastern Kern Rule 210.4, EPA Region 9, 

Attachment 4 – Evaluation of 40 CFR 51.166 and Imperial Rule 904, Placer Rule 518, and 

Yolo-Solano Rule 3.24, EPA Region 9, 

• Attachment 5 – Letters received from EKAPCD, ICAPCD, and PCAPCD regarding the 

PM2.5 SILs

• Attachment 6 – List of EPA-issued PSD Permits for EKAPCD, ICAPCD, PCAPCD, and 

YSAQMD, EPA Region 9