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51.166 Requirements of 40 CFR 51.166 for a SIP approved PSD program Where included in 

Rules 904, 518, and 

3.24 or in 40 CFR 

52.21 as IBR in each 

Rule

(a)(1) Plan requirements (1) Plan requirements. In accordance with the policy of section 101(b)(1) of the Act and the 

purposes of section 160 of the Act, each applicable State Implementation Plan and each 

applicable Tribal Implementation Plan shall contain emission limitations and such other measures 

as may be necessary to prevent significant deterioration of air quality.

With this action the 

District would adopt a 

PSD program into the CA 

SIP

(a)(2) Plan revisions (2) Plan revisions. If a State Implementation Plan revision would result in increased air quality 

deterioration over any baseline concentration, the plan revision shall include a demonstration that 

it will not cause or contribute to a violation of the applicable increment(s). If a plan revision 

proposing less restrictive requirements was submitted after August 7, 1977 but on or before any 

applicable baseline date and was pending action by the Administrator on that date, no such 

demonstration is necessary with respect to the area for which a baseline date would be 

established before final action is taken on the plan revision. Instead, the assessment described in 

paragraph (a)(4) of this section, shall review the expected impact to the applicable increment(s).

Not applicable to this 

action. 

(a)(3) Required plan 

revision

(3) Required plan revision. If the State or the Administrator determines that a plan is 

substantially inadequate to prevent significant deterioration or that an applicable increment is 

being violated, the plan shall be revised to correct the inadequacy or the violation. The plan shall 

be revised within 60 days of such a finding by a State or within 60 days following notification by 

the Administrator, or by such later date as prescribed by the Administrator after consultation with 

the State.

Not applicable to this 

action.

(a)(4) Plan assessment (4) Plan assessment. The State shall review the adequacy of a plan on a periodic basis and within 

60 days of such time as information becomes available that an applicable increment is being 

violated.

Not applicable to this 

action.

(a)(5) Public 

participation

(5) Public participation. Any State action taken under this paragraph shall be subject to the 

opportunity for public hearing in accordance with procedures equivalent to those established in 

§51.102.

Public notice (10/17/11, 

1/13/2011, 5/2/2012) 

and public hearing 

(12/20/2011, 2/10/2011, 

6/13/2012) were held. 

(a)(6) Amendments (6) Amendments. 

(i) Any State required to revise its implementation plan by reason of an amendment to this 

section, with the exception of amendments to add new maximum allowable increases or other 

measures pursuant to section 166(a) of the Act, shall adopt and submit such plan revision to 

the Administrator for approval no later than 3 years after such amendment is published in 

theFederal Register.With regard to a revision to an implementation plan by reason of an 

amendment to paragraph (c) of this section to add maximum allowable increases or other 

measures, the State shall submit such plan revision to the Administrator for approval within 21 

months after such amendment is published in the Federal Register.

Not applicable to this 

action
Requirements for a SIP Approved PSD Program in 40 CFR 51.166 and How those Requirements are met by 

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Page 2of 51

(ii) Any revision to an implementation plan that would amend the provisions for the prevention 

of significant air quality deterioration in the plan shall specify when and as to what sources and 

modifications the revision is to take effect.

Not applicable to this 

action.

(iii) Any revision to an implementation plan that an amendment to this section required shall 

take effect no later than the date of its approval and may operate prospectively.

Not applicable to this 

action.

(a)(7) Applicability (7) Applicability. Each plan shall contain procedures that incorporate the requirements in 

paragraphs (a)(7)(i) through (vi) of this section.

40 CFR 52.21(a)(2)

(i) The requirements of this section apply to the construction of any new major stationary 

source (as defined in paragraph (b)(1) of this section) or any project at an existing major 

stationary source in an area designated as attainment or unclassifiable under sections 

107(d)(1)(A)(ii) or (iii) of the Act.

40 CFR 52.21(a)(2)(i)

(ii) The requirements of paragraphs (j) through (r) of this section apply to the construction of 

any new major stationary source or the major modification of any existing major stationary 

source, except as this section otherwise provides.

40 CFR 52.21(a)(2)(ii)

(iii) No 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 that the major stationary source or major modification will meet those 

requirements.

40 CFR 52.21(a)(2)(iii)

(iv) Each plan shall use the specific provisions of paragraphs (a)(7)(iv)( a ) through ( f ) of this 

section. Deviations from these provisions will be approved only if the 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 this 

section.

40 CFR 52.21(a)(2)(iv)

( a ) Except as otherwise provided in paragraphs (a)(7)(v) and (vi) of this section, and 

consistent with the definition of major modification contained in paragraph (b)(2) of this 

section, a project is a major modification for a regulated NSR pollutant if it causes two types 

of emissions increases—a significant emissions increase (as defined in paragraph (b)(39) of 

this section), and a significant net emissions increase (as defined in paragraphs (b)(3) and 

(b)(23) of this section). The project is not a major modification if it does not cause a 

significant emissions increase. If the project causes a significant emissions increase, then the 

project is a major modification only if it also results in a significant net emissions increase.

40 CFR 

52.21(a)(2)(iv)(a )

( b ) The procedure for calculating (before beginning actual construction) whether a 

significant emissions increase ( i.e. , the first step of the process) will occur depends upon 

the type of emissions units being modified, according to paragraphs (a)(7)(iv)( c ) through ( 

f ) of this section. The procedure for calculating (before beginning actual construction) 

whether a significant net emissions increase will occur at the major stationary source ( i.e. , 

the second step of the process) is contained in the definition in paragraph (b)(3) of this 

section. Regardless of any such preconstruction projections, a major modification results if 

the project causes a significant emissions increase and a significant net emissions increase.

40 CFR 

52.21(a)(2)(iv)(b )
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( c ) Actual-to-projected-actual applicability test for projects that only involve existing 

emissions units. A significant emissions increase of a regulated NSR pollutant is projected to 

occur if the sum of the difference between the projected actual emissions (as defined in 

paragraph (b)(40) of this section) and the baseline actual emissions (as defined in paragraphs 

(b)(47)(i) and (ii) of this section) for each existing emissions unit, equals or exceeds the 

significant amount for that pollutant (as defined in paragraph (b)(23) of this section).

40 CFR 

52.21(a)(2)(iv)(c )

( d ) Actual-to-potential test for projects that only involve construction of a new emissions 

unit(s). A significant emissions increase of a regulated NSR pollutant is projected to occur if 

the sum of the difference between the potential to emit (as defined in paragraph (b)(4) of 

this section) from each new emissions unit following completion of the project and the 

baseline actual emissions (as defined in paragraph (b)(47)(iii) of this section) of these units 

before the project equals or exceeds the significant amount for that pollutant (as defined in 

paragraph (b)(23) of this section).

40 CFR 

52.21(a)(2)(iv)(d )

( e ) [Reserved] 40 CFR 

52.21(a)(2)(iv)(e )

( f ) Hybrid test for projects that involve multiple types of emissions units. A significant 

emissions increase of a regulated NSR pollutant is projected to occur if the sum of the 

emissions increases for each emissions unit, using the method specified in paragraphs 

(a)(7)(iv)( c ) through ( d ) of this section as applicable with respect to each emissions unit, 

for each type of emissions unit equals or exceeds the significant amount for that pollutant (as 

defined in paragraph (b)(23) of this section).

40 CFR 

52.21(a)(2)(iv)(f )

(v) The plan shall require that for any major stationary source for a PAL for a regulated NSR 

pollutant, the major stationary source shall comply with requirements under paragraph (w) of 

this section.

40 CFR 52.21(a)(2)(v)

(b) Definitions (b) Definitions. All State plans shall use the following definitions for the purposes of this section. 

Deviations from the following wording will be approved only if the State specifically demonstrates 

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

corresponding definitions below:

40 CFR 52.21(b)

(b)(1) Major stationary 

source

(1)(i) Major stationary source means: 40 CFR 52.21(b)(1)(i)

( a ) Any of the following stationary sources of air pollutants which emits, or has the potential 

to emit, 100 tons per year or more of any regulated NSR pollutant: Fossil fuel-fired steam 

electric plants of more than 250 million British thermal units per hour heat input, coal 

cleaning plants (with thermal dryers), kraft pulp mills, portland cement plants, primary zinc 

smelters, iron and steel mill plants, primary aluminum ore reduction plants (with thermal 

dryers), primary copper smelters, municipal incinerators capable of charging more than 250 

tons of refuse per day, hydrofluoric, sulfuric, and nitric acid plants, petroleum refineries, lime 

plants, phosphate rock processing plants, coke oven batteries, sulfur recovery plants, carbon 

black plants (furnace process), primary lead smelters, fuel conversion plants, sintering plants, 

secondary metal production plants, chemical process plants (which does not include ethanol 

production facilities that produce ethanol by natural fermentation included in NAICS codes 

325193 or 312140), fossil-fuel boilers (or combinations thereof) totaling more than 250 

million British thermal units per hour heat input, petroleum storage and transfer units with a 

total storage capacity exceeding 300,000 barrels, taconite ore processing plants, glass fiber 

processing plants, and charcoal production plants;

40 CFR 52.21(b)(1)(i)(a )
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( b ) Notwithstanding the stationary source size specified in paragraph (b)(1)(i)( a ) of this 

section, any stationary source which emits, or has the potential to emit, 250 tons per year or 

more of a regulated NSR pollutant; or

40 CFR 52.21(b)(1)(i)(b )

( c ) Any physical change that would occur at a stationary source not otherwise qualifying 

under paragraph (b)(1) of this section, as a major stationary source if the change would 

constitute a major stationary source by itself.

40 CFR 52.21(b)(1)(i)(c )

(ii) A major source that is major for volatile organic compounds or NOXshall be considered 

major for ozone.

40 CFR 52.21(b)(1)(ii)

(iii) The fugitive emissions of a stationary source shall not be included in determining for any of 

the purposes of this section whether it is a major stationary source, unless the source belongs 

to one of the following categories of stationary sources:

( a ) Coal cleaning plants (with thermal dryers);

( b ) Kraft pulp mills;

( c ) Portland cement plants;

( d ) Primary zinc smelters;

( e ) Iron and steel mills;

( f ) Primary aluminum ore reduction plants;

( g ) Primary copper smelters;

( h ) Municipal incinerators capable of charging more than 250 tons of refuse per day;

( i ) Hydrofluoric, sulfuric, or nitric acid plants;

( j ) Petroleum refineries;

( k ) Lime plants;

( l ) Phosphate rock processing plants;

( m ) Coke oven batteries;

( n ) Sulfur recovery plants;

( o ) Carbon black plants (furnace process);

( p ) Primary lead smelters;

( q ) Fuel conversion plants;

( r ) Sintering plants;

( s ) Secondary metal production plants;

( t ) Chemical process plants—The term chemical processing plant shall not include ethanol 

production facilities that produce ethanol by natural fermentation included in NAICS codes 

325193 or 312140;

( u ) Fossil-fuel boilers (or combination thereof) totaling more than 250 million British 

thermal units per hour heat input;

( v ) Petroleum storage and transfer units with a total storage capacity exceeding 300,000 

barrels;

( w ) Taconite ore processing plants;

40 CFR 52.21(b)(1)(ii)
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( x ) Glass fiber processing plants;

( y ) Charcoal production plants;

( z ) Fossil fuel-fired steam electric plants of more that 250 million British thermal units per 

hour heat input;

( aa ) Any other stationary source category which, as of August 7, 1980, is being regulated 

under section 111 or 112 of the Act.

(b)(2) Major modification (2)(i) Major modification means any physical change in or change in the method of operation of a 

major stationary source that would result in: a significant emissions increase (as defined in 

paragraph (b)(39) of this section) of a regulated NSR pollutant (as defined in paragraph (b)(49) 

of this section); and a significant net emissions increase of that pollutant from the major 

stationary source.

40 CFR 52.21(b)(2)(i)

(ii) Any significant emissions increase (as defined at paragraph (b)(39) of this section) from 

any emissions units or net emissions increase (as defined in paragraph (b)(3) of this section) at 

a major stationary source that is significant for volatile organic compounds or NOXshall be 

considered significant for ozone.

40 CFR 52.21(b)(2)(ii)

(iii) A physical change or change in the method of operation shall not include: 40 CFR 52.21(b)(2)(iii)

( a ) Routine maintenance, repair and replacement. Routine maintenance, repair and 

replacement shall include, but not be limited to, any activity(s) that meets the requirements 

of the equipment replacement provisions contained in paragraph (y) of this section;

Note to paragraph (b)(2)(iii)( a ): On December 24, 2003, the second sentence of this 

paragraph (b)(2)(iii)( a ) is stayed indefinitely by court order. The stayed provisions will 

become effective immediately if the court terminates the stay. At that time, EPA will publish a 

document in the Federal Register advising the public of the termination of the stay.

( b ) Use of an alternative fuel or raw material by reason of any order under section 2 (a) 

and (b) of the Energy Supply and Environmental Coordination Act of 1974 (or any 

superseding legislation) or by reason of a natural gas curtailment plan pursuant to the 

Federal Power Act;

40 CFR 

52.21(b)(2)(iii)(b )

( c ) Use of an alternative fuel by reason of an order or rule under section 125 of the Act; 40 CFR 

52.21(b)(2)(iii)(c )

( d ) Use of an alternative fuel at a steam generating unit to the extent that the fuel is 

generated from municipal solid waste;

40 CFR 

52.21(b)(2)(iii)(d )

( e ) Use of an alternative fuel or raw material by a stationary source which: 40 CFR 

52.21(b)(2)(iii)(e )

( 1 ) The source was capable of accommodating before January 6, 1975, unless such 

change would be prohibited under any federally enforceable permit condition which was 

established after January 6, 1975 pursuant to 40 CFR 52.21 or under regulations approved 

pursuant to 40 CFR subpart I or §51.166; or

40 CFR 

52.21(b)(2)(iii)(e )(1 )

( 2 ) The source is approved to use under any permit issued under 40 CFR 52.21 or under 

regulations approved pursuant to 40 CFR 51.166;

40 CFR 

52.21(b)(2)(iii)(e )(2 )

( f ) An increase in the hours of operation or in the production rate, unless such change 

would be prohibited under any federally enforceable permit condition which was established 

after January 6, 1975, pursuant to 40 CFR 52.21 or under regulations approved pursuant to 

40 CFR subpart I or §51.166.

40 CFR 

52.21(b)(2)(iii)(f )

40 CFR 

52.21(b)(2)(iii)(a )
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( g ) Any change in ownership at a stationary source. 40 CFR 

52.21(b)(2)(iii)(g )

( h ) [Reserved] 40 CFR 

52.21(b)(2)(iii)(h )

( i ) The installation, operation, cessation, or removal of a temporary clean coal technology 

demonstration project, provided that the project complies with:

40 CFR 52.21(b)(2)(iii)(i )

( 1 ) The State implementation plan for the State in which the project is located; and 40 CFR 

52.21(b)(2)(iii)(i )(1 )

( 2 ) Other requirements necessary to attain and maintain the national ambient air quality 

standards during the project and after it is terminated.

40 CFR 

52.21(b)(2)(iii)(i )(2 )

( j ) The installation or operation of a permanent clean coal technology demonstration project 

that constitutes repowering, provided that the project does not result in an increase in the 

potential to emit of any regulated pollutant emitted by the unit. This exemption shall apply on 

a pollutant-by-pollutant basis.

40 CFR 52.21(b)(2)(iii)(j )

( k ) The reactivation of a very clean coal-fired electric utility steam generating unit. 40 CFR 

52.21(b)(2)(iii)(k )

(iv) This definition shall not apply with respect to a particular regulated NSR pollutant when the 

major stationary source is complying with the requirements under paragraph (w) of this section 

for a PAL for that pollutant. Instead, the definition at paragraph (w)(2)(viii) of this section shall 

apply.

40 CFR 52.21(b)(2)(iv)

(v) Fugitive emissions shall not be included in determining for any of the purposes of this 

section whether a physical change in or change in the method of operation of a major 

stationary source is a major modification, unless the source belongs to one of the source 

categories listed in paragraph (b)(1)(iii) of this section.

40 CFR 52.21(b)(2)(v)

(b)(3) Net emissions 

increase

(3)(i) Net emissions increase means, with respect to any regulated NSR pollutant emitted by a 

major stationary source, the amount by which the sum of the following exceeds zero:

40 CFR 52.21(b)(3)(i)

( a ) The increase in emissions from a particular physical change or change in the method of 

operation at a stationary source as calculated pursuant to paragraph (a)(7)(iv) of this 

section; and

40 CFR 52.21(b)(3)(i)(a )

( b ) Any other increases and decreases in actual emissions at the major stationary source 

that are contemporaneous with the particular change and are otherwise creditable. Baseline 

actual emissions for calculating increases and decreases under this paragraph (b)(3)(i)( b ) 

shall be determined as provided in paragraph (b)(47), except that paragraphs (b)(47)(i)( c ) 

and (b)(47)(ii)( d ) of this section shall not apply.

40 CFR 52.21(b)(3)(i)(b )

(ii) An increase or decrease in actual emissions is contemporaneous with the increase from the 

particular change only if it occurs within a reasonable period (to be specified by the State) 

before the date that the increase from the particular change occurs.

40 CFR 52.21(b)(3)(ii)

(iii) An increase or decrease in actual emissions is creditable only if: 40 CFR 52.21(b)(3)(iii)

( a ) It occurs within a reasonable period (to be specified by the reviewing authority); and 40 CFR 

52.21(b)(3)(iii)(a )
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( b ) The reviewing authority has not relied on it in issuing a permit for the source under 

regulations approved pursuant to this section, which permit is in effect when the increase in 

actual emissions from the particular change occurs; and

40 CFR 

52.21(b)(3)(iii)(b )

( c ) The increase or decrease in emissions did not occur at a Clean Unit, except as provided 

in paragraphs (t)(8) and (u)(10) of this section.

40 CFR 

52.21(b)(3)(iii)(c )

( d ) As it pertains to an increase or decrease in fugitive emissions (to the extent 

quantifiable), it occurs at an emissions unit that is part of one of the source categories listed 

in paragraph (b)(1)(iii) of this section or it occurs at an emission unit that is located at a 

major stationary source that belongs to one of the listed source categories. Fugitive emission 

increases or decreases are not included for those emissions units located at a facility whose 

primary activity is not represented by one of the source categories listed in paragraph 

(b)(1)(iii) of this section and that are not, by themselves, part of a listed source category.

40 CFR 

52.21(b)(3)(iii)(d ) 

Second sentence not 

included, but provision 

was stayed indefinitely, 

see 76 FR 17556, Mar. 

30, 2011, 

(iv) An increase or decrease in actual emissions of sulfur dioxide, particulate matter, or 

nitrogen oxides that occurs before the applicable minor source baseline date is creditable only if 

it is required to be considered in calculating the amount of maximum allowable increases 

remaining available.

40 CFR 52.21(b)(3)(iv)

(v) An increase in actual emissions is creditable only to the extent that the new level of actual 

emissions exceeds the old level.

40 CFR 52.21(b)(3)(v)

(vi) A decrease in actual emissions is creditable only to the extent that: 40 CFR 52.21(b)(3)(vi)

( a ) The old level of actual emissions or the old level of allowable emissions, whichever is 

lower, exceeds the new level of actual emissions;

40 CFR 

52.21(b)(3)(vi)(a )

( b ) It is enforceable as a practical matter at and after the time that actual construction on 

the particular change begins;

40 CFR 

52.21(b)(3)(vi)(b )

( c ) It has approximately the same qualitative significance for public health and welfare as 

that attributed to the increase from the particular change; and

40 CFR 

52.21(b)(3)(vi)(c )

(vii) An increase that results from a physical change at a source occurs when the emissions unit 

on which construction occurred becomes operational and begins to emit a particular pollutant. 

Any replacement unit that requires shakedown becomes operational only after a reasonable 

shakedown period, not to exceed 180 days.

40 CFR 52.21(b)(3)(vii)

(viii) Paragraph (b)(21)(ii) of this section shall not apply for determining creditable increases 

and decreases.

40 CFR 52.21(b)(3)(viii)

(b)(4) Potential to emit (4) Potential to emit means the maximum capacity of a stationary source to emit a pollutant 

under its physical and operational design. Any physical or operational limitation on the capacity of 

the source to emit a pollutant, including air pollution control equipment and restrictions on hours 

of operation or on the type or amount of material combusted, stored, or processed, shall be 

treated as part of its design if the limitation or the effect it would have on emissions is federally 

enforceable. Secondary emissions do not count in determining the potential to emit of a 

stationary source.

40 CFR 52.21(b)(4) 

(b)(5) Stationary source (5) Stationary source means any building, structure, facility, or installation which emits or may 

emit a regulated NSR pollutant.

40 CFR 52.21(b)(5)
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(b)(6) Building, 

structure, facility, 

or installation

(6) Building, structure, facility, or installation means all of the pollutant-emitting activities which 

belong to the same industrial grouping, are located on one or more contiguous or adjacent 

properties, and are under the control of the same person (or persons under common control) 

except the activities of any vessel. Pollutant-emitting activities shall be considered as part of the 

same industrial grouping if they belong to the same Major Group ( i.e. , which have the same 

two-digit code) as described in the Standard Industrial Classification Manual, 1972, as amended 

by the 1977 Supplement (U.S. Government Printing Office stock numbers 4101–0066 and 

003–005–00176–0, respectively).

40 CFR 52.21(b)(6)

(b)(7) Emissions unit (7) Emissions unit means any part of a stationary source that emits or would have the potential 

to emit any regulated NSR pollutant and includes an electric utility steam generating unit as 

defined in paragraph (b)(30) of this section. For purposes of this section, there are two types of 

emissions units as described in paragraphs (b)(7)(i) and (ii) of this section.

40 CFR 52.21(b)(7)

(i) A new emissions unit is any emissions unit that is (or will be) newly constructed and that has 

existed for less than 2 years from the date such emissions unit first operated.

40 CFR 52.21(b)(7)(i)

(ii) An existing emissions unit is any emissions unit that does not meet the requirements in 

paragraph (b)(7)(i) of this section. A replacement unit, as defined in paragraph (b)(32) of this 

section, is an existing emissions unit.

40 CFR 52.21(b)(7)(ii)

(b)(8) Construction (8) Construction means any physical change or change in the method of operation (including 

fabrication, erection, installation, demolition, or modification of an emissions unit) that would 

result in a change in emissions.

40 CFR 52.21(b)(8)

(b)(9) Commence (9) Commence as applied to construction of a major stationary source or major modification 

means that the owner or operator has all necessary preconstruction approvals or permits and 

either has:

40 CFR 52.21(b)(9)

(i) Begun, or caused to begin, a continuous program of actual on-site construction of the 

source, to be completed within a reasonable time; or

40 CFR 52.21(b)(9)(i)

(ii) Entered into binding agreements or contractual obligations, which cannot be cancelled or 

modified without substantial loss to the owner or operator, to undertake a program of actual 

construction of the source to be completed within a reasonable time.

40 CFR 52.21(b)(9)(ii)

(b)(10) Necessary 

preconstruction 

approvals or 

permits

(10) Necessary preconstruction approvals or permits means those permits or approvals required 

under Federal air quality control laws and regulations and those air quality control laws and 

regulations which are part of the applicable State Implementation Plan.

40 CFR 52.21(b)(10)

(b)(11) Begin actual 

construction

(11) Begin actual construction means, in general, initiation of physical on-site construction 

activities on an emissions unit which are of a permanent nature. Such activities include, but are 

not limited to, installation of building supports and foundations, laying of underground pipework, 

and construction of permanent storage structures. With respect to a change in method of 

operation this term refers to those on-site activities, other than preparatory activities, which 

mark the initiation of the change.

40 CFR 52.21(b)(11)
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(b)(12) Best available 

control technology

(12) Best available control technology means an emissions limitation (including a visible 

emissions standard) based on the maximum degree of reduction for each a regulated NSR 

pollutant which would be emitted from any proposed major stationary source or major 

modification which the reviewing authority, on a case-by-case basis, taking into account energy, 

environmental, and economic impacts and other costs, determines is achievable for such source 

or modification through application of production processes or available methods, systems, and 

techniques, including fuel cleaning or treatment or innovative fuel combination techniques for 

control of such pollutant. In no event shall application of best available control technology result 

in emissions of any pollutant which would exceed the emissions allowed by any applicable 

standard under 40 CFR parts 60 and 61. If the reviewing authority determines that technological 

or economic limitations on the application of measurement methodology to a particular emissions 

unit would make the imposition of an emissions standard infeasible, a design, equipment, work 

practice, operational standard or combination thereof, may be prescribed instead to satisfy the 

requirement for the application of best available control technology. Such standard shall, to the 

degree possible, set forth the emissions reduction achievable by implementation of such design, 

40 CFR 52.21(b)(12)

(b)(13) Baseline 

concentration

(13)(i) Baseline concentration means that ambient concentration level that exists in the baseline 

area at the time of the applicable minor source baseline date. A baseline concentration is 

determined for each pollutant for which a minor source baseline date is established and shall 

include:

40 CFR 52.21(b)(13)(i)

( a ) The actual emissions, as defined in paragraph (b)(21) of this section, representative of 

sources in existence on the applicable minor source baseline date, except as provided in 

paragraph (b)(13)(ii) of this section;

40 CFR 

52.21(b)(13)(i)(a )

( b ) The allowable emissions of major stationary sources that commenced construction 

before the major source baseline date, but were not in operation by the applicable minor 

source baseline date.

40 CFR 

52.21(b)(13)(i)(b )

(ii) The following will not be included in the baseline concentration and will affect the applicable 

maximum allowable increase(s):

40 CFR 52.21(b)(13)(ii)

( a ) Actual emissions, as defined in paragraph (b)(21) of this section, from any major 

stationary source on which construction commenced after the major source baseline date; 

and

40 CFR 

52.21(b)(13)(ii)(a )

( b ) Actual emissions increases and decreases, as defined in paragraph (b)(21) of this 

section, at any stationary source occurring after the minor source baseline date.

40 CFR 

52.21(b)(13)(ii)(b )

(b)(14) Major source 

baseline date

(14)(i) Major source baseline date means: 40 CFR 52.21(b)(14)(i)

( a ) In the case of PM10and sulfur dioxide, January 6, 1975; 40 CFR 

52.21(b)(14)(i)(a )

( b ) In the case of nitrogen dioxide, February 8, 1988; and 40 CFR 

52.21(b)(14)(i)(b )

( c ) In the case of PM2.5,October 20, 2010. 40 CFR 

52.21(b)(14)(i)(c )

(ii) Minor source baseline date means the earliest date after the trigger date on which a major 

stationary source or a major modification subject to 40 CFR 52.21 or to regulations approved 

pursuant to 40 CFR 51.166 submits a complete application under the relevant regulations. The 

trigger date is:

40 CFR 52.21(b)(14)(ii)

( a ) In the case of PM10and sulfur dioxide, August 7, 1977; 40 CFR 

52.21(b)(14)(ii)(a )

( b ) In the case of nitrogen dioxide, February 8, 1988; and 40 CFR 

52.21(b)(14)(ii)(b )
Requirements for a SIP Approved PSD Program in 40 CFR 51.166 and How those Requirements are met by 

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( c ) In the case of PM2.5,October 20, 2011. 40 CFR 

52.21(b)(14)(ii)(c )

(iii) The baseline date is established for each pollutant for which increments or other equivalent 

measures have been established if:

40 CFR 52.21(b)(14)(iii)

( a ) The area in which the proposed source or modification would construct is designated as 

attainment or unclassifiable under section 107(d)(1)(A)(ii) or (iii) of the Act for the pollutant 

on the date of its complete application under 40 CFR 52.21 or under regulations approved 

pursuant to 40 CFR 51.166; and

40 CFR 

52.21(b)(14)(iii)(a )

( b ) In the case of a major stationary source, the pollutant would be emitted in significant 

amounts, or, in the case of a major modification, there would be a significant net emissions 

increase of the pollutant.

40 CFR 

52.21(b)(14)(iii)(b )

(iv) Any minor source baseline date established originally for the TSP increments shall remain 

in effect and shall apply for purposes of determining the amount of available PM–10 

increments, except that the reviewing authority may rescind any such minor source baseline 

date where it can be shown, to the satisfaction of the reviewing authority, that the emissions 

increase from the major stationary source, or the net emissions increase from the major 

modification, responsible for triggering that date did not result in a significant amount of PM–10 

emissions.

40 CFR 52.21(b)(14)(iv)

(b)(15) Baseline area (15)(i) Baseline area means any intrastate area (and every part thereof) designated as 

attainment or unclassifiable under section 107(d)(1)(A)(ii) or (iii) of the Act in which the major 

source or major modification establishing the minor source baseline date would construct or 

would have an air quality impact for the pollutant for which the baseline date is established, as 

follows: Equal to or greater than 1 μg/m3(annual average) for SO2,NO2, or PM10; or equal or 

greater than 0.3 μg/m3(annual average) for PM2.5.

40 CFR 52.21(b)(15)(i)

(ii) Area redesignations under section 107(d)(1)(A)(ii) or (iii) of the Act cannot intersect or be 

smaller than the area of impact of any major stationary source or major modification which:

40 CFR 52.21(b)(15)(ii)

( a ) Establishes a minor source baseline date; or 40 CFR 

52.21(b)(15)(i)(a )

( b ) Is subject to 40 CFR 52.21 or under regulations approved pursuant to 40 CFR 51.166, 

and would be constructed in the same State as the State proposing the redesignation.

40 CFR 

52.21(b)(15)(i)(b )

(iii) Any baseline area established originally for the TSP increments shall remain in effect and 

shall apply for purposes of determining the amount of available PM–10 increments, except that 

such baseline area shall not remain in effect if the permit authority rescinds the corresponding 

minor source baseline date in accordance with paragraph (b)(14)(iv) of this section.

40 CFR 52.21(b)(15)(iii)

(b)(16) Allowable 

emissions

(16) Allowable emissions means the emissions rate of a stationary source calculated using the 

maximum rated capacity of the source (unless the source is subject to federally enforceable limits 

which restrict the operating rate, or hours of operation, or both) and the most stringent of the 

following:

40 CFR 52.21(b)(16) - 

(i) The applicable standards as set forth in 40 CFR parts 60 and 61; 40 CFR 52.21(b)(16)(i)

(ii) The applicable State Implementation Plan emissions limitation, including those with a future 

compliance date; or

40 CFR 52.21(b)(16)(ii)
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Imperial Rule 904, Placer Rule 518, and Yolo-Solano Rule 3.24

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(iii) The emissions rate specified as a federally enforceable permit condition. 40 CFR 52.21(b)(16)(iii) - 

also adds the phrase 

"including those with a 

future compliance date". 

The resulting definition is 

at least as stringent than 

the definition in 51.166.

(b)(17) Federally 

enforceable

(17) Federally enforceable means all limitations and conditions which are enforceable by the 

Administrator, including those requirements developed pursuant to 40 CFR parts 60 and 61, 

requirements within any applicable State implementation plan, any permit requirements 

established pursuant to 40 CFR 52.21 or under regulations approved pursuant to 40 CFR part 51, 

subpart I, including operating permits issued under an EPA-approved program that is 

incorporated into the State implementation plan and expressly requires adherence to any permit 

issued under such program.

40 CFR 52.21(b)(17) - 

Rules 904, 518, and 3.24 

revise the term 

"Administrator" in 40 CFR 

52.21(b)(17) to mean the 

"Federal Administator" 

instead of the APCO as 

required by 51.166.

(b)(18) Secondary 

emissions

(18) Secondary emissions means emissions which occur as a result of the construction or 

operation of a major stationary source or major modification, but do not come from the major 

stationary source or major modification itself. For the purposes of this section, secondary 

emissions must be specific, well defined, quantifiable, and impact the same general areas the 

stationary source modification which causes the secondary emissions. Secondary emissions 

include emissions from any offsite support facility which would not be constructed or increase its 

emissions except as a result of the construction or operation of the major stationary source or 

major modification. Secondary emissions do not include any emissions which come directly from 

a mobile source, such as emissions from the tailpipe of a motor vehicle, from a train, or from a 

vessel.

40 CFR 52.21(b)(18) - 

Wording is slightly 

different, but is at least 

as stringent as the 

definition in 51.166.

(b)(19) Innovative control 

technology

(19) Innovative control technology means any system of air pollution control that has not been 

adequately demonstrated in practice, but would have a substantial likelihood of achieving greater 

continuous emissions reduction than any control system in current practice or of achieving at 

least comparable reductions at lower cost in terms of energy, economics, or nonair quality 

environmental impacts.

40 CFR 52.21(b)(19)

(b)(20) Fugitive emissions (20) Fugitive emissions means those emissions which could not reasonably pass through a stack, 

chimney, vent, or other functionally equivalent opening.

40 CFR 52.21(b)(20)

(b)(21) Actual emissions (21)(i) Actual emissions means the actual rate of emissions of a regulated NSR pollutant from an 

emissions unit, as determined in accordance with paragraphs (b)(21)(ii) through (iv) of this 

section, except that this definition shall not apply for calculating whether a significant emissions 

increase has occurred, or for establishing a PAL under paragraph (w) of this section. Instead, 

paragraphs (b)(40) and (b)(47) of this section shall apply for those purposes.

40 CFR 52.21(b)(21)(i)
Requirements for a SIP Approved PSD Program in 40 CFR 51.166 and How those Requirements are met by 

Imperial Rule 904, Placer Rule 518, and Yolo-Solano Rule 3.24

Page 12of 51

(ii) In general, 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 consecutive 24-month period 

which precedes the particular date and which is representative of normal source operation. The 

reviewing authority shall allow the use of a different time period upon a determination that it is 

more representative of normal source operation. Actual 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.

40 CFR 52.21(b)(21)(ii)

(iii) The reviewing authority may presume that source-specific allowable emissions for the unit 

are equivalent to the actual emissions of the unit.

40 CFR 52.21(b)(21)(iii)

(iv) For any emissions unit that has not begun normal operations on the particular date, actual 

emissions shall equal the potential to emit of the unit on that date.

40 CFR 52.21(b)(21)(iv)

(b)(22) Complete (22) Complete means, in reference to an application for a permit, that the application contains all 

the information necessary for processing the application. Designating an application complete for 

purposes of permit processing does not preclude the reviewing authority from requesting or 

accepting any additional information.

40 CFR 52.21(b)(22)

(b)(23) Significant (23)(i) Significant means, in reference to a net emissions increase or the potential of a source to 

emit any of the following pollutants, a rate of emissions that would equal or exceed any of the 

following rates:

Pollutant and Emissions Rate

Carbon monoxide: 100 tons per year (tpy)

Nitrogen oxides: 40 tpy

Sulfur dioxide: 40 tpy

Particulate matter: 25 tpy of particulate matter emissions. 15 tpy of PM10emissions

PM2.5: 10 tpy of direct PM2.5emissions; 40 tpy of sulfur dioxide emissions; 40 tpy of nitrogen 

oxide emissions unless demonstrated not to be a PM2.5precursor under paragraph (b)(49) of 

this section

Ozone: 40 tpy of volatile organic compounds or nitrogen oxides

Lead: 0.6 tpy

Fluorides: 3 tpy

Sulfuric acid mist: 7 tpy

Hydrogen sulfide (H2S): 10 tpy

Total reduced sulfur (including H2S): 10 tpy

Reduced sulfur compounds (including H2S): 10 tpy

Municipal waste combustor organics (measured as total tetra-through octa-chlorinated 

dibenzo-p-dioxins and dibenzofurans): 3.2 × 10–−6megagrams per year (3.5 × 10−6tons per 

year)

Municipal waste combustor metals (measured as particulate matter): 14 megagrams per year 

(15 tons per year)

Municipal waste combustor acid gases (measured as sulfur dioxide and hydrogen chloride): 

36 megagrams per year (40 tons per year)

40 CFR 52.21(b)(23)(i)
Requirements for a SIP Approved PSD Program in 40 CFR 51.166 and How those Requirements are met by 

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Municipal solid waste landfill emissions (measured as nonmethane organic compounds): 45 

megagrams per year (50 tons per year)

(ii) Significant means, in reference to a net emissions increase or the potential of a source to 

emit a regulated NSR pollutant that paragraph (b)(23)(i) of this section, does not list, any 

emissions rate.

40 CFR 52.21(b)(23)(ii)

(iii) Notwithstanding paragraph (b)(23)(i) of this section, significant means any emissions rate 

or any net emissions increase associated with a major stationary source or major modification, 

which would construct within 10 kilometers of a Class I area, and have an impact on such area 

equal to or greater than 1 μg/m3(24-hour average).

40 CFR 52.21(b)(23)(iii)

(b)(24) Federal Land 

Manager

(24) Federal Land Manager means, with respect to any lands in the United States, the Secretary 

of the department with authority over such lands.

40 CFR 52.21(b)(24)

(b)(25) High terrrain (25) High terrain means any area having an elevation 900 feet or more above the base of the 

stack of a source.

40 CFR 52.21(b)(25)

(b)(26) Low terrain (26) Low terrain means any area other than high terrain. 40 CFR 52.21(b)(26)

(b)(27) Indian 

Reservation

(27) Indian Reservation means any federally recognized reservation established by Treaty, 

Agreement, Executive Order, or Act of Congress.

40 CFR 52.21(b)(27)

(b)(28) Indian Governing 

Body

(28) Indian Governing Body means the governing body of any tribe, band, or group of Indians 

subject to the jurisdiction of the United States and recognized by the United States as possessing 

power of self-government.

40 CFR 52.21(b)(28)

(b)(29) VOC (29) Volatile organic compounds (VOC) is as defined in §51.100(s) of this part. 40 CFR 52.21(b)(30)

(b)(30) Electric utility 

steam generating 

unit

(30) Electric utility steam generating unit means any steam electric generating unit that is 

constructed for the purpose of supplying more than one-third of its potential electric output 

capacity and more than 25 MW electrical output to any utility power distribution system for sale. 

Any steam supplied to a steam distribution system for the purpose of providing steam to a steamelectric generator that would produce electrical energy for sale is also considered in determining 

the electrical energy output capacity of the affected facility.

40 CFR 52.21(b)(31)

(b)(31) (31) [Reserved]

(b)(32) Replacement unit (32) Replacement unit means an emissions unit for which all the criteria listed in paragraphs 

(b)(32)(i) through (iv) of this section are met. No creditable emission reductions shall be 

generated from shutting down the existing emissions unit that is replaced.

40 CFR 52.21(b)(33)

(i) The emissions unit is a reconstructed unit within the meaning of §60.15(b)(1) of this 

chapter, or the emissions unit completely takes the place of an existing emissions unit.

40 CFR 52.21(b)(33)(i)

(ii) The emissions unit is identical to or functionally equivalent to the replaced emissions unit. 40 CFR 52.21(b)(33)(ii)

(iii) The replacement does not change the basic design parameter(s) (as discussed in paragraph 

(y)(2) of this section) of the process unit.

40 CFR 52.21(b)(33)(iii)

(iv) The replaced emissions unit is permanently removed from the major stationary source, 

otherwise permanently disabled, or permanently barred from operation by a permit that is 

enforceable as a practical matter. If the replaced emissions unit is brought back into operation, 

it shall constitute a new emissions unit.

40 CFR 52.21(b)(33)(iv)
Requirements for a SIP Approved PSD Program in 40 CFR 51.166 and How those Requirements are met by 

Imperial Rule 904, Placer Rule 518, and Yolo-Solano Rule 3.24

Page 14of 51

(b)(33) Clean coal 

technology 

(33) Clean coal technology means any technology, including technologies applied at the 

precombustion, combustion, or post combustion stage, at a new or existing facility which will 

achieve significant reductions in air emissions of sulfur dioxide or oxides of nitrogen associated 

with the utilization of coal in the generation of electricity, or process steam which was not in 

widespread use as of November 15, 1990.

40 CFR 52.21(b)(34)

(b)(34) Clean coal 

technology 

demonstration 

project

(34) Clean coal technology demonstration project means a project using funds appropriated 

under the heading “Department of Energy—Clean Coal Technology”, up to a total amount of 

$2,500,000,000 for commercial demonstration of clean coal technology, or similar projects 

funded through appropriations for the Environmental Protection Agency. The Federal contribution 

for a qualifying project shall be at least 20 percent of the total cost of the demonstration project.

40 CFR 52.21(b)(35)

(b)(35) Temporary clean 

coal technology 

demonstration 

project

(35) Temporary clean coal technology demonstration project means a clean coal technology 

demonstration project that is operated for a period of 5 years or less, and which complies with 

the State implementation plan for the State in which the project is located and other 

requirements necessary to attain and maintain the national ambient air quality standards during 

and after the project is terminated.

40 CFR 52.21(b)(36)

(b)(36) Repowering (36)(i) Repowering means replacement of an existing coal-fired boiler with one of the following 

clean coal technologies: atmospheric or pressurized fluidized bed combustion, integrated 

gasification combined cycle, magnetohydrodynamics, direct and indirect coal-fired turbines, 

integrated gasification fuel cells, or as determined by the Administrator, in consultation with the 

Secretary of Energy, a derivative of one or more of these technologies, and any other technology 

capable of controlling multiple combustion emissions simultaneously with improved boiler or 

generation efficiency and with significantly greater waste reduction relative to the performance of 

technology in widespread commercial use as of November 15, 1990.

40 CFR 52.21(b)(17) - 

Rules 904, 518, and 3.24 

revise the term 

"Administrator" in 40 CFR 

52.21(b)(37)(i) to mean 

the "Federal 

Administator" instead of 

the APCO as required by 

51.166.

(ii) Repowering shall also include any oil and/or gas-fired unit which has been awarded clean 

coal technology demonstration funding as of January 1, 1991, by the Department of Energy.

40 CFR 52.21(b)(37)(ii)

(iii) The reviewing authority shall give expedited consideration to permit applications for any 

source that satisfies the requirements of this subsection and is granted an extension under 

section 409 of the Clean Air Act.

40 CFR 52.21(b)(37)(ii)

(b)(37) Reactivation (37) Reactivation of a very clean coal-fired electric utility steam generating unit means any 

physical change or change in the method of operation associated with the commencement of 

commercial operations by a coal-fired utility unit after a period of discontinued operation where 

the unit:

40 CFR 52.21(b)(38)

(i) Has not been in operation for the two-year period prior to the enactment of the Clean Air Act 

Amendments of 1990, and the emissions from such unit continue to be carried in the permitting 

authority's emissions inventory at the time of enactment;

40 CFR 52.21(b)(38)(i)

(ii) Was equipped prior to shutdown with a continuous system of emissions control that 

achieves a removal efficiency for sulfur dioxide of no less than 85 percent and a removal 

efficiency for particulates of no less than 98 percent;

40 CFR 52.21(b)(38)(ii)

(iii) Is equipped with low-NOXburners prior to the time of commencement of operations 

following reactivation; and

40 CFR 52.21(b)(38)(iii)

(iv) Is otherwise in compliance with the requirements of the Clean Air Act. 40 CFR 52.21(b)(38)(iv)
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(b)(38) Pollution 

prevention

(38) Pollution prevention means any activity that through process changes, product 

reformulation or redesign, or substitution of less polluting raw materials, eliminates or reduces 

the release of air pollutants (including fugitive emissions) and other pollutants to the environment 

prior to recycling, treatment, or disposal; it does not mean recycling (other than certain “inprocess recycling” practices), energy recovery, treatment, or disposal.

40 CFR 52.21(b)(39)

(b)(39) Significant 

emissions

(39) Significant emissions increase means, for a regulated NSR pollutant, an increase in 

emissions that is significant (as defined in paragraph (b)(23) of this section) for that pollutant.

40 CFR 52.21(b)(4)

(b)(40) Projected actual 

emissions

(40)(i) Projected actual emissions means the maximum annual rate, in tons per year, at which 

an existing emissions unit is projected to emit a regulated NSR pollutant in any one of the 5 

years (12-month period) following the date the unit resumes regular operation after the project, 

or in any one of the 10 years following that date, if the project involves increasing the emissions 

unit's design capacity or its potential to emit that regulated NSR pollutant, and full utilization of 

the unit would result in a significant emissions increase, or a significant net emissions increase at 

the major stationary source.

40 CFR 52.21(b)(41)(i)

(ii) In determining the projected actual emissions under paragraph (b)(40)(i) of this section 

(before beginning actual construction), the owner or operator of the major stationary source:

40 CFR 52.21(b)(41)(ii)

( a ) Shall consider all relevant information, including but not limited to, historical operational 

data, the company's own representations, the company's expected business activity and the 

company's highest projections of business activity, the company's filings with the State or 

Federal regulatory authorities, and compliance plans under the approved plan; and

40 CFR 

52.21(b)(41)(i)(a )

( b ) Shall include fugitive emissions to the extent quantifiable, and emissions associated with 

startups, shutdowns, and malfunctions; and

40 CFR 

52.21(b)(41)(i)(b )

( c ) Shall exclude, in calculating any increase in emissions that results from the particular 

project, that portion of the unit's emissions following the project that an existing unit could 

have accommodated during the consecutive 24-month period used to establish the baseline 

actual emissions under paragraph (b)(47) of this section and that are also unrelated to the 

particular project, including any increased utilization due to product demand growth; or,

40 CFR 

52.21(b)(41)(i)(c )

( d ) In lieu of using the method set out in paragraphs (b)(40)(ii)( a ) through ( c ) of this 

section, may elect to use the emissions unit's potential to emit, in tons per year, as defined 

under paragraph (b)(4) of this section.

40 CFR 

52.21(b)(41)(i)(d )

(b)(41) (41) [Reserved]
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Page 16of 51

(b)(42) PSD Program (42) Prevention of Significant Deterioration Program (PSD) program means a major source 

preconstruction permit program that has been approved by the Administrator and incorporated 

into the plan to implement the requirements of this section, or the program in §52.21 of this 

chapter. Any permit issued under such a program is a major NSR permit.

40 CFR 52.21(b)(43) - 

slightly different wording 

but still at least as 

stringent as 51.166 

defintion - In addition, 

Rules 904, 518, and 3.24 

revise the term 

"Administrator" in 40 CFR 

52.21(b)(43) to mean the 

"Federal Administator" 

instead of the APCO as 

required by 51.166.

(b)(43) CEMS (43) Continuous emissions monitoring system (CEMS) means all of the equipment that may be 

required to meet the data acquisition and availability requirements of this section, to sample, 

condition (if applicable), analyze, and provide a record of emissions on a continuous basis.

40 CFR 52.21(b)(44) - 

(b)(44) PEMS (44) Predictive emissions monitoring system (PEMS) means all of the equipment necessary to 

monitor process and control device operational parameters (for example, control device 

secondary voltages and electric currents) and other information (for example, gas flow rate, O2 

or CO2concentrations), and calculate and record the mass emissions rate (for example, lb/hr) on 

a continuous basis.

40 CFR 52.21(b)(45)

(b)(45) CPMS (45) Continuous parameter monitoring system (CPMS) means all of the equipment necessary to 

meet the data acquisition and availability requirements of this section, to monitor process and 

control device operational parameters (for example, control device secondary voltages and 

electric currents) and other information (for example, gas flow rate, O2 or CO2concentrations), 

and to record average operational parameter value(s) on a continuous basis.

40 CFR 52.21(b)(46)

(b)(46) CERMS (46) Continuous emissions rate monitoring system (CERMS) means the total equipment required 

for the determination and recording of the pollutant mass emissions rate (in terms of mass per 

unit of time).

40 CFR 52.21(b)(47)

(b)(47) Baseline actual 

emissions

(47) Baseline actual emissions means the rate of emissions, in tons per year, of a regulated NSR 

pollutant, as determined in accordance with paragraphs (b)(47)(i) through (iv) of this section.

40 CFR 52.21(b)(48)

(i) For any existing electric utility steam generating unit, baseline actual emissions means the 

average rate, in tons per year, at which the unit actually emitted the pollutant during any 

consecutive 24-month period selected by the owner or operator within the 5-year period 

immediately preceding when the owner or operator begins actual construction of the project. 

The reviewing authority shall allow the use of a different time period upon a determination that 

it is more representative of normal source operation.

40 CFR 52.21(b)(48)(i)

( a ) The average rate shall include fugitive emissions to the extent quantifiable, and 

emissions associated with startups, shutdowns, and malfunctions.

40 CFR 

52.21(b)(48)(i)(a )

( b ) The average rate shall be adjusted downward to exclude any non-compliant emissions 

that occurred while the source was operating above an emission limitation that was legally 

enforceable during the consecutive 24-month period.

40 CFR 

52.21(b)(48)(i)(b )
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( c ) For a regulated NSR pollutant, when a project involves multiple emissions units, only 

one consecutive 24-month period must be used to determine the baseline actual emissions 

for the emissions units being changed. A different consecutive 24-month period can be used 

For each regulated NSR pollutant.

40 CFR 

52.21(b)(48)(i)(c )

( d ) The average rate shall not be based on any consecutive 24-month period for which 

there is inadequate information for determining annual emissions, in tons per year, and for 

adjusting this amount if required by paragraph (b)(47)(i)( b ) of this section.

40 CFR 

52.21(b)(48)(i)(d )

(ii) For an existing emissions unit (other than an electric utility steam generating unit), baseline 

actual emissions means the average rate, in tons per year, at which the emissions unit actually 

emitted the pollutant during any consecutive 24-month period selected by the owner or 

operator within the 10-year period immediately preceding either the date the owner or operator 

begins actual construction of the project, or the date a complete permit application is received 

by the reviewing authority for a permit required either under this section or under a plan 

approved by the Administrator, whichever is earlier, except that the 10-year period shall not 

include any period earlier than November 15, 1990.

40 CFR 52.21(b)(48)(ii)

( a ) The average rate shall include fugitive emissions to the extent quantifiable, and 

emissions associated with startups, shutdowns, and malfunctions.

40 CFR 

52.21(b)(48)(ii)(a )

( b ) The average rate shall be adjusted downward to exclude any non-compliant emissions 

that occurred while the source was operating above an emission limitation that was legally 

enforceable during the consecutive 24-month period.

40 CFR 

52.21(b)(48)(ii)(b )

( c ) The average rate shall be adjusted downward to exclude any emissions that would have 

exceeded an emission limitation with which the major stationary source must currently 

comply, had such major stationary source been required to comply with such limitations 

during the consecutive 24-month period. However, if an emission limitation is part of a 

maximum achievable control technology standard that the Administrator proposed or 

promulgated under part 63 of this chapter, the baseline actual emissions need only be 

adjusted if the State has taken credit for such emissions reductions in an attainment 

demonstration or maintenance plan consistent with the requirements of §51.165(a)(3)(ii)(G).

40 CFR 

52.21(b)(48)(ii)(c ) - 

Rules 904, 518, and 3.24 

revise the term 

"Administrator" in 40 CFR 

52.21(b)(48)(ii)(c) to 

mean the "Federal 

Administator" instead of 

the APCO as required by 

51.166.

( d ) For a regulated NSR pollutant, when a project involves multiple emissions units, only 

one consecutive 24-month period must be used to determine the baseline actual emissions 

for the emissions units being changed. A different consecutive 24-month period can be used 

For each regulated NSR pollutant.

40 CFR 

52.21(b)(48)(ii)(d )

( e ) The average rate shall not be based on any consecutive 24-month period for which 

there is inadequate information for determining annual emissions, in tons per year, and for 

adjusting this amount if required by paragraphs (b)(47)(ii)(b) and (c) of this section.

40 CFR 

52.21(b)(48)(ii)(e )

(iii) For a new emissions unit, the baseline actual emissions for purposes of determining the 

emissions increase that will result from the initial construction and operation of such unit shall 

equal zero; and thereafter, for all other purposes, shall equal the unit's potential to emit.

40 CFR 52.21(b)(48)(iii)
Requirements for a SIP Approved PSD Program in 40 CFR 51.166 and How those Requirements are met by 

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Page 18of 51

(iv) For a PAL for a stationary source, the baseline actual emissions shall be calculated for 

existing electric utility steam generating units in accordance with the procedures contained in 

paragraph (b)(47)(i) of this section, for other existing emissions units in accordance with the 

procedures contained in paragraph (b)(47)(ii) of this section, and for a new emissions unit in 

accordance with the procedures contained in paragraph (b)(47)(iii) of this section.

40 CFR 52.21(b)(48)(iv)

(b)(48) Subject to 

regulation

(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 this chapter, 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:

40 CFR 52.21(b)(49) 

(i) Greenhouse gases (GHGs), the air pollutant defined in §86.1818–12(a) of this chapter 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.

40 CFR 52.21(b)(49)(i)

(ii) For purposes of paragraphs (b)(48)(iii) through (v) of this section, the term tpy CO 2 

equivalent emissions (CO 2 e) shall represent an amount of GHGs emitted, and shall be 

computed as follows:

40 CFR 52.21(b)(49)(ii)

(a) Multiplying the mass amount of emissions (tpy), for each of the six greenhouse gases in 

the pollutant GHGs, by the gas's associated global warming potential published at Table A–1 

to subpart A of part 98 of this chapter—Global Warming Potentials. For purposes of this 

paragraph (b)(48)(ii)(a), prior to July 21, 2014, the mass of the greenhouse gas carbon 

dioxide shall not include carbon dioxide emissions resulting from the combustion or 

decomposition of non-fossilized and biodegradable organic material originating from plants, 

animals, or micro-organisms (including products, by-products, residues and waste from 

agriculture, forestry and related industries as well as the non-fossilized and biodegradable 

organic fractions of industrial and municipal wastes, including gases and liquids recovered 

from the decomposition of non-fossilized and biodegradable organic material).

40 CFR 

52.21(b)(49)(ii)(a ) -

( b ) Sum the resultant value from paragraph (b)(48)(ii)( a ) of this section for each gas to 

compute a tpy CO2e.

40 CFR 

52.21(b)(49)(ii)(b )

(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 tpy CO2e, and shall be calculated assuming the pollutant GHGs is a regulated NSR 

pollutant, and “significant” is defined as 75,000 tpy CO2e instead of applying the value in 

paragraph (b)(23)(ii) of this section.

40 CFR 52.21(b)(49)(iii)

(iv) Beginning January 2, 2011, the pollutant GHGs is subject to regulation if: 40 CFR 52.21(b)(49)(iv)
Requirements for a SIP Approved PSD Program in 40 CFR 51.166 and How those Requirements are met by 

Imperial Rule 904, Placer Rule 518, and Yolo-Solano Rule 3.24

Page 19of 51

( 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 tpy CO2e or 

more; or

40 CFR 

52.21(b)(49)(iv)(a )

( 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 tpy CO2e or more; and,

40 CFR 

52.21(b)(49)(iv)(b )

(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:

40 CFR 52.21(b)(49)(v)

( a ) At a new stationary source that will emit or have the potential to emit 100,000 tpy 

CO2e; or

40 CFR 

52.21(b)(49)(v)(a )

( b ) At an existing stationary source that emits or has the potential to emit 100,000 tpy 

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 tpy CO2e or more.

40 CFR 

52.21(b)(49)(v)(b )

(b)(49) Regulated NSR 

pollutant

(49) Regulated NSR pollutant, for purposes of this section, means the following: 40 CFR 52.21(b)(50)

(i) Any pollutant for which a national ambient air quality standard has been promulgated and 

any pollutant identified under this paragraph (b)(49)(i) as a constituent or precursor to such 

pollutant. Precursors identified by the Administrator for purposes of NSR are the following:

40 CFR 52.21(b)(50)(i) - 

Rules 904, 518, and 3.24 

revise the term 

"Administrator" in 40 CFR 

52.21(b)(50)(i) to mean 

the "Federal 

Administator" instead of 

the APCO as required by 

51.166.

( a ) Volatile organic compounds and nitrogen oxides are precursors to ozone in all 

attainment and unclassifiable areas.

40 CFR 

52.21(b)(50)(i)(a )

( b ) Sulfur dioxide is a precursor to PM2.5in all attainment and unclassifiable areas. 40 CFR 

52.21(b)(50)(i)(b )

( c ) Nitrogen oxides are presumed to be precursors to PM2.5in all attainment and 

unclassifiable areas, unless the State demonstrates to the Administrator's satisfaction or EPA 

demonstrates that emissions of nitrogen oxides from sources in a specific area are not a 

significant contributor to that area's ambient PM2.5concentrations.

40 CFR 

52.21(b)(50)(i)(c )

( d ) Volatile organic compounds are presumed not to be precursors to PM2.5in any 

attainment or unclassifiable area, unless the State demonstrates to the Administrator's 

satisfaction or EPA demonstrates that emissions of volatile organic compounds from sources 

in a specific area are a significant contributor to that area's ambient PM2.5concentrations.

40 CFR 

52.21(b)(50)(i)(d )

(ii) Any pollutant that is subject to any standard promulgated under section 111 of the Act; 40 CFR 52.21(b)(50)(ii)

(iii) Any Class I or II substance subject to a standard promulgated under or established by title 

VI of the Act;

40 CFR 52.21(b)(50)(iii)

(iv) Any pollutant that otherwise is subject to regulation under the Act as defined in paragraph 

(b)(48) of this section.

40 CFR 52.21(b)(50)(iv)
Requirements for a SIP Approved PSD Program in 40 CFR 51.166 and How those Requirements are met by 

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Page 20of 51

(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.

40 CFR 52.21(b)(50)(v)

(vi) Particulate matter (PM) emissions, PM2.5emissions, and PM10emissions shall include gaseous 

emissions from a source or activity which condense to form particulate matter at ambient 

temperatures. On or after January 1, 2011 (or any earlier date established in the upcoming 

rulemaking codifying test methods), such condensable particulate matter shall be accounted for 

in applicability determinations and in establishing emissions limitations for PM, PM2.5and PM10in 

PSD permits. Compliance with emissions limitations for PM, PM2.5and PM10issued prior to this 

date shall not be based on condensable particular matter unless required by the terms and 

conditions of the permit or the applicable implementation plan. Applicability determinations 

made prior to this date without accounting for condensable particular matter shall not be 

considered in violation of this section unless the applicable implementation plan required 

condensable particular matter to be included.

40 CFR 52.21(b)(50)(vi)

(b)(50) Reviewing 

authority

(50) Reviewing authority means the State air pollution control agency, local agency, other State 

agency, Indian tribe, or other agency authorized by the Administrator to carry out a permit 

program under §51.165 and this section, or the Administrator in the case of EPA-implemented 

permit programs under §52.21 of this chapter.

40 CFR 52.21(b)(51) - 

Rules 904, 518, and 3.24 

revise the term 

"Administrator" in 40 CFR 

52.21(b)(51) to mean the 

"Federal Administator" 

instead of the APCO as 

required by 51.166.

(b)(51) Project (51) Project means a physical change in, or change in method of operation of, an existing major 

stationary source.

40 CFR 52.21(b)(52)

(b)(52) LAER (52) Lowest achievable emission rate (LAER) is as defined in §51.165(a)(1)(xiii). 40 CFR 52.21(b)(53)

(b)(53) Process unit (53)(i) In general, process unit means any collection of structures and/or equipment that 

processes, assembles, applies, blends, or otherwise uses material inputs to produce or store an 

intermediate or a completed product. A single stationary source may contain more than one 

process unit, and a process unit may contain more than one emissions unit.

(ii) Pollution control equipment is not part of the process unit, unless it serves a dual function 

as both process and control equipment. Administrative and warehousing facilities are not part 

of the process unit.

(iii) For replacement cost purposes, components shared between two or more process units are 

proportionately allocated based on capacity.

(iv) The following list identifies the process units at specific categories of stationary sources.

40 CFR 52.21(b)(55) - 

But excluded from Rules 

904, 518, and 3.24. 

These provisions were 

stayed indefinitely by the 

DC Circuit Court on 

December 24, 2003 and 

are not needed for a PSD 

program.
Requirements for a SIP Approved PSD Program in 40 CFR 51.166 and How those Requirements are met by 

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Page 21of 51

( a ) For a steam electric generating facility, the process unit consists of those portions of the 

plant that contribute directly to the production of electricity. For example, at a pulverized coalfired facility, the process unit would generally be the combination of those systems from the 

coal receiving equipment through the emission stack (excluding post-combustion pollution 

controls), including the coal handling equipment, pulverizers or coal crushers, feedwater 

heaters, ash handling, boiler, burners, turbine-generator set, condenser, cooling tower, water 

treatment system, air preheaters, and operating control systems. Each separate generating 

unit is a separate process unit.

( b ) For a petroleum refinery, there are several categories of process units: those that 

separate and/or distill petroleum feedstocks; those that change molecular structures; 

petroleum treating processes; auxiliary facilities, such as steam generators and hydrogen 

production units; and those that load, unload, blend or store intermediate or completed 

products.

( c ) For an incinerator, the process unit would consist of components from the feed pit or 

refuse pit to the stack, including conveyors, combustion devices, heat exchangers and steam 

generators, quench tanks, and fans.

Note to paragraph (b)(53): By a court order on December 24, 2003, this paragraph (b)(53) is 

stayed indefinitely. The stayed provisions will become effective immediately if the court 

terminates the stay. At that time, EPA will publish a document in the Federal Register 

advising the public of the termination of the stay.

(b)(54) Functionally 

equivalent 

component

(54) Functionally equivalent component means a component that serves the same purpose as 

the replaced component.

Note to paragraph (b)(54): By a court order on December 24, 2003, this paragraph (b)(54) is 

stayed indefinitely. The stayed provisions will become effective immediately if the court 

terminates the stay. At that time, EPA will publish a document in the Federal Register advising 

the public of the termination of the stay.

(b)(55) Fixed capital cost (55) Fixed capital cost means the capital needed to provide all the depreciable components. 

“Depreciable components” refers to all components of fixed capital cost and is calculated by 

subtracting land and working capital from the total capital investment, as defined in paragraph 

(b)(56) of this section.

Note to paragraph (b)(55): By a court order on December 24, 2003, this paragraph (b)(55) is 

stayed indefinitely. The stayed provisions will become effective immediately if the court 

terminates the stay. At that time, EPA will publish a document in the Federal Register advising 

the public of the termination of the stay.

(b)(56) Total capital 

investment

(56) Total capital investment means the sum of the following: all costs required to purchase 

needed process equipment (purchased equipment costs); the costs of labor and materials for 

installing that equipment (direct installation costs); the costs of site preparation and buildings; 

other costs such as engineering, construction and field expenses, fees to contractors, startup and 

performance tests, and contingencies (indirect installation costs); land for the process 

equipment; and working capital for the process equipment.

40 CFR 52.21(b)(56) - 

But excluded from Rules 

904, 518, and 3.24. 

These provisions were 

stayed indefinitely by the 

DC Circuit Court on 

December 24, 2003 and 

are not needed for a PSD 

40 CFR 52.21(b)(57) - 

But excluded from Rules 

904, 518, and 3.24. 

These provisions were 

stayed indefinitely by the 

DC Circuit Court on 

December 24, 2003 and 

are not needed for a PSD 

program

40 CFR 52.21(b)(58) - 

But excluded from Rules 

904, 518, and 3.24. 

These provisions were 

stayed indefinitely by the 

DC Circuit Court on 

December 24, 2003 and 
Requirements for a SIP Approved PSD Program in 40 CFR 51.166 and How those Requirements are met by 

Imperial Rule 904, Placer Rule 518, and Yolo-Solano Rule 3.24

Page 22of 51

Note to paragraph (b)(56): By a court order on December 24, 2003, this paragraph (b)(56) is 

stayed indefinitely. The stayed provisions will become effective immediately if the court 

terminates the stay. At that time, EPA will publish a document in the Federal Register advising 

the public of the termination of the stay.

(c ) Ambient air 

increments and 

other measures

(c) Ambient air increments and other measures. 40 CFR 52.21(c )

(1) The plan shall contain emission limitations and such other measures as may be necessary to 

assure that in areas designated as Class I, II, or III, increases in pollutant concentrations over 

the baseline concentration shall be limited to the following:

See Table 1 below.

For any period other than an annual period, the applicable maximum allowable increase may be 

exceeded during one such period per year at any one location.

(2) Where the State can demonstrate that it has alternative measures in its plan other than 

maximum allowable increases as defined under paragraph (c)(1) of this section, that satisfy the 

requirements in sections 166(c) and 166(d) of the Clean Air Act for a regulated NSR pollutant for 

which the Administrator has established maximum allowable increases pursuant to section 166(a) 

of the Act, the requirements for maximum allowable increases for that pollutant under paragraph 

(c)(1) of this section shall not apply upon approval of the plan by the Administrator. The following 

regulated NSR pollutants are eligible for such treatment:

(i) Nitrogen dioxide.

(ii) PM2.5.

(d) Ambient air 

ceilings

(d) Ambient air ceilings. The plan shall provide that no concentration of a pollutant shall exceed: 40 CFR 52.21(d)

(1) The concentration permitted under the national secondary ambient air quality standard, or 40 CFR 52.21(d)(1)

(2) The concentration permitted under the national primary ambient air quality standard, 

whichever concentration is lowest for the pollutant for a period of exposure.

40 CFR 52.21(d)(2)

(e) Restrictions on 

area 

classifications

(e) Restrictions on area classifications. The plan shall provide that— 40 CFR 52.21(e)

(1) All of the following areas which were in existence on August 7, 1977, shall be Class I areas 

and may not be redesignated:

40 CFR 52.21(e)(1)

(i) International parks, 40 CFR 52.21(e)(1)(i)

(ii) National wilderness areas which exceed 5,000 acres in size, 40 CFR 52.21(e)(1)(ii)

(iii) National memorial parks which exceed 5,000 acres in size, and 40 CFR 52.21(e)(1)(iii)

(iv) National parks which exceed 6,000 acres in size. 40 CFR 52.21(e)(1)(iv)

40 CFR 52.21(c )

No such demonstration 

has been made

December 24, 2003 and 

are not needed for a PSD 

program
Requirements for a SIP Approved PSD Program in 40 CFR 51.166 and How those Requirements are met by 

Imperial Rule 904, Placer Rule 518, and Yolo-Solano Rule 3.24

Page 23of 51

(2) Areas which were redesignated as Class I under regulations promulgated before August 7, 

1977, shall remain Class I, but may be redesignated as provided in this section.

40 CFR 52.21(e)(2)

(3) Any other area, unless otherwise specified in the legislation creating such an area, is initially 

designated Class II, but may be redesignated as provided in this section.

40 CFR 52.21(e)(3)

(4) The following areas may be redesignated only as Class I or II: 40 CFR 52.21(e)(4)

(i) An area which as of August 7, 1977, exceeded 10,000 acres in size and was a national 

monument, a national primitive area, a national preserve, a national recreational area, a 

national wild and scenic river, a national wildlife refuge, a national lakeshore or seashore; and

40 CFR 52.21(e)(4)(i)

(ii) A national park or national wilderness area established after August 7, 1977, which exceeds 

10,000 acres in size.

40 CFR 52.21(e)(4)(ii)

(f) Exclusions from 

increment 

consumption

(f) Exclusions from increment consumption.

(1) The plan may provide that the following concentrations shall be excluded in determining 

compliance with a maximum allowable increase:

(i) Concentrations attributable to the increase in emissions from stationary sources which have 

converted from the use of petroleum products, natural gas, or both by reason of an order in 

effect under section 2 (a) and (b) of the Energy Supply and Environmental Coordination Act of 

1974 (or any superseding legislation) over the emissions from such sources before the effective 

date of such an order;

(ii) Concentrations attributable to the increase in emissions from sources which have converted 

from using natural gas by reason of natural gas curtailment plan in effect pursuant to the 

Federal Power Act over the emissions from such sources before the effective date of such plan;

(iii) Concentrations of particulate matter attributable to the increase in emissions from 

construction or other temporary emission-related activities of new or modified sources;

(iv) The increase in concentrations attributable to new sources outside the United States over 

the concentrations attributable to existing sources which are included in the baseline 

concentration; and

(v) Concentrations attributable to the temporary increase in emissions of sulfur dioxide, 

particulate matter, or nitrogen oxides from stationary sources which are affected by plan 

revisions approved by the Administrator as meeting the criteria specified in paragraph (f)(4) of 

this section.

(2) If the plan provides that the concentrations to which paragraph (f)(1) (i) or (ii) of this 

section, refers shall be excluded, it shall also provide that no exclusion of such concentrations 

shall apply more than five years after the effective date of the order to which paragraph (f)(1)(i) 

of this section, refers or the plan to which paragraph (f)(1)(ii) of this section, refers, whichever is 

applicable. If both such order and plan are applicable, no such exclusion shall apply more than 

five years after the later of such effective dates.

(3) [Reserved]

(4) For purposes of excluding concentrations pursuant to paragraph (f)(1)(v) of this section, the 

Administrator may approve a plan revision that:

Not included in 40 CFR 

52.21 or Rules 904, 518, 

and 3.24. These 

provisions are not 

required for a PSD 

program because 40 CFR 

51.166(f)(1) states that 

the plan "may" provide 

these exclusions. 

Paragraphs (2)-(4) only 

apply if the plan provides 

for the exclusions in 

paragraph (1).
Requirements for a SIP Approved PSD Program in 40 CFR 51.166 and How those Requirements are met by 

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Page 24of 51

(i) Specifies the time over which the temporary emissions increase of sulfur dioxide, particulate 

matter, or nitrogen oxides would occur. Such time is not to exceed 2 years in duration unless a 

longer time is approved by the Administrator.

(ii) Specifies that the time period for excluding certain contributions in accordance with 

paragraph (f)(4)(i) of this section, is not renewable;

(iii) Allows no emissions increase from a stationary source which would:

( a ) Impact a Class I area or an area where an applicable increment is known to be violated; 

or

( b ) Cause or contribute to the violation of a national ambient air quality standard;

(iv) Requires limitations to be in effect the end of the time period specified in accordance with 

paragraph (f)(4)(i) of this section, which would ensure that the emissions levels from stationary 

sources affected by the plan revision would not exceed those levels occurring from such 

sources before the plan revision was approved.

(g) Redesignation (g) Redesignation. 

(1) The plan shall provide that all areas of the State (except as otherwise provided under 

paragraph (e) of this section) shall be designated either Class I, Class II, or Class III. Any 

designation other than Class II shall be subject to the redesignation procedures of this 

paragraph. Redesignation (except as otherwise precluded by paragraph (e) of this section) may 

be proposed by the respective States or Indian Governing Bodies, as provided below, subject to 

approval by the Administrator as a revision to the applicable State implementation plan.

(2) The plan may provide that the State may submit to the Administrator a proposal to 

redesignate areas of the State Class I or Class II: Provided, That:

(i) At least one public hearing has been held in accordance with procedures established in 

§51.102.

(ii) Other States, Indian Governing Bodies, and Federal Land Managers whose lands may be 

affected by the proposed redesignation were notified at least 30 days prior to the public 

hearing;

(iii) A discussion of the reasons for the proposed redesignation, including a satisfactory 

description and analysis of the health, environmental, economic, social, and energy effects of 

the proposed redesignation, was prepared and made available for public inspection at least 30 

days prior to the hearing and the notice announcing the hearing contained appropriate 

notification of the availability of such discussion;

(iv) Prior to the issuance of notice respecting the redesignation of an area that includes any 

Federal lands, the State has provided written notice to the appropriate Federal Land Manager 

and afforded adequate opportunity (not in excess of 60 days) to confer with the State 

respecting the redesignation and to submit written comments and recommendations. In 

redesignating any area with respect to which any Federal Land Manager had submitted written 

comments and recommendations, the State shall have published a list of any inconsistency 

between such redesignation and such comments and recommendations (together with the 

reasons for making such redesignation against the recommendation of the Federal Land 

Manager); and

40 CFR 52.21(g) - But 

Rules 904, 518 and 3.24 

exclude these provisions 

regarding redesignations. 

These provisions allow 

states and Indian 

Governing Bodies to 

redesignate certain 

areas. States are not 

required to redesignate 

areas, so these 

provisions are not needed 

for a PSD program. As a 

result, all area 

designations will be 

governed by 40 CFR 

52.21(e).
Requirements for a SIP Approved PSD Program in 40 CFR 51.166 and How those Requirements are met by 

Imperial Rule 904, Placer Rule 518, and Yolo-Solano Rule 3.24

Page 25of 51

(v) The State has proposed the redesignation after consultation with the elected leadership of 

local and other substate general purpose governments in the area covered by the proposed 

redesignation.

(3) The plan may provide that any area other than an area to which paragraph (e) of this section 

refers may be redesignated as Class III if—

(i) The redesignation would meet the requirements of provisions established in accordance with 

paragraph (g)(2) of this section;

(ii) The redesignation, except any established by an Indian Governing Body, has been 

specifically approved by the Governor of the State, after consultation with the appropriate 

committees of the legislature, if it is in session, or with the leadership of the legislature, if it is 

not in session (unless State law provides that such redesignation must be specifically approved 

by State legislation) and if general purpose units of local government representing a majority of 

the residents of the area to be redesignated enact legislation (including resolutions where 

appropriate) concurring in the redesignation;

(iii) The redesignation would not cause, or contribute to, a concentration of any air pollutant 

which would exceed any maximum allowable increase permitted under the classification of any 

other area or any national ambient air quality standard; and

(iv) Any permit application for any major stationary source or major modification subject to 

provisions established in accordance with paragraph (l) of this section which could receive a 

permit only if the area in question were redesignated as Class III, and any material submitted 

as part of that application, were available, insofar as was practicable, for public inspection prior 

to any public hearing on redesignation of any area as Class III.

(4) The plan shall provide that lands within the exterior boundaries of Indian Reservations may 

be redesignated only by the appropriate Indian Governing Body. The appropriate Indian 

Governing Body may submit to the Administrator a proposal to redesignate areas Class I, Class 

II, or Class III: Provided, That:

(i) The Indian Governing Body has followed procedures equivalent to those required of a State 

under paragraphs (g) (2), (3)(iii), and (3)(iv) of this section; and

(ii) Such redesignation is proposed after consultation with the State(s) in which the Indian 

Reservation is located and which border the Indian Reservation.

(5) The Administrator shall disapprove, within 90 days of submission, a proposed redesignation 

of any area only if he finds, after notice and opportunity for public hearing, that such 

redesignation does not meet the procedural requirements of this section or is inconsistent with 

paragraph (e) of this section. If any such disapproval occurs, the classification of the area shall 

be that which was in effect prior to the redesignation which was disapproved.

(6) If the Administrator disapproves any proposed area designation, the State or Indian 

Governing Body, as appropriate, may resubmit the proposal after correcting the deficiencies 

noted by the Administrator.

(h) Stack heights (h) Stack heights. The plan shall provide, as a minimum, that the degree of emission limitation 

required for control of any air pollutant under the plan shall not be affected in any manner by—

(1) So much of a stack height, not in existence before December 31, 1970, as exceeds good 

engineering practice, or

(2) Any other dispersion technique not implemented before then.

40 CFR 52.21(h)
Requirements for a SIP Approved PSD Program in 40 CFR 51.166 and How those Requirements are met by 

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Page 26of 51

(i) Exemptions (i) Exemptions. 40 CFR 52.21(i)

(1) The plan may provide that requirements equivalent to those contained in paragraphs (j) 

through (r) of this section do not apply to a particular major stationary source or major 

modification if:

40 CFR 52.21(i)(1)

(i) The major stationary source would be a nonprofit health or nonprofit educational institution 

or a major modification that would occur at such an institution; or

40 CFR 52.21(i)(1)(vi)

(ii) The source or modification would be a major stationary source or major modification only if 

fugitive emissions, to the extent quantifiable, are considered in calculating the potential to emit 

of the stationary source or modification and such source does not belong to any of the following 

categories:

( a ) Coal cleaning plants (with thermal dryers);

( b ) Kraft pulp mills;

( c ) Portland cement plants;

( d ) Primary zinc smelters;

( e ) Iron and steel mills;

( f ) Primary aluminum ore reduction plants;

( g ) Primary copper smelters;

( h ) Municipal incinerators capable of charging more than 250 tons of refuse per day;

( i ) Hydrofluoric, sulfuric, or nitric acid plants;

( j ) Petroleum refineries;

( k ) Lime plants;

( l ) Phosphate rock processing plants;

( m ) Coke oven batteries;

( n ) Sulfur recovery plants;

( o ) Carbon black plants (furnace process);

( p ) Primary lead smelters;

( q ) Fuel conversion plants;

( r ) Sintering plants;

( s ) Secondary metal production plants;

( t ) Chemical process plants—The term chemical processing plant shall not include ethanol 

production facilities that produce ethanol by natural fermentation included in NAICS codes 

325193 or 312140;

( u ) Fossil-fuel boilers (or combination thereof) totaling more than 250 million British 

thermal units per hour heat input;

( v ) Petroleum storage and transfer units with a total storage capacity exceeding 300,000 

barrels;

( w ) Taconite ore processing plants;

( x ) Glass fiber processing plants;

40 CFR 52.21(i)(1)(vii)
Requirements for a SIP Approved PSD Program in 40 CFR 51.166 and How those Requirements are met by 

Imperial Rule 904, Placer Rule 518, and Yolo-Solano Rule 3.24

Page 27of 51

( y ) Charcoal production plants;

( z ) Fossil fuel-fired steam electric plants of more than 250 million British thermal units per 

hour heat input;

( aa ) Any other stationary source category which, as of August 7, 1980, is being regulated 

under section 111 or 112 of the Act; or

(iii) The source or modification is a portable stationary source which has previously received a 

permit under requirements equivalent to those contained in paragraphs (j) through (r) of this 

section, if:

40 CFR 52.21(i)(1)(viii)

( a ) The source proposes to relocate and emissions of the source at the new location would 

be temporary; and

40 CFR 

52.21(i)(1)(viii)(a )

( b ) The emissions from the source would not exceed its allowable emissions; and 40 CFR 

52.21(i)(1)(viii)(b )

( c ) The emissions from the source would impact no Class I area and no area where an 

applicable increment is known to be violated; and

40 CFR 

52.21(i)(1)(viii)(c )

( d ) Reasonable notice is given to the reviewing authority prior to the relocation identifying 

the proposed new location and the probable duration of operation at the new location. Such 

notice shall be given to the reviewing authority not less than 10 days in advance of the 

proposed relocation unless a different time duration is previously approved by the reviewing 

authority.

40 CFR 

52.21(i)(1)(viii)(d )

(2) The plan may provide that requirements equivalent to those contained in paragraphs (j) 

through (r) of this section do not apply to a major stationary source or major modification with 

respect to a particular pollutant if the owner or operator demonstrates that, as to that pollutant, 

the source or modification is located in an area designated as nonattainment under section 107 of 

the Act.

40 CFR 52.21(i)(2)

(3) The plan may provide that requirements equivalent to those contained in paragraphs (k), 

(m), and (o) of this section do not apply to a proposed major stationary source or major 

modification with respect to a particular pollutant, if the allowable emissions of that pollutant 

from a new source, or the net emissions increase of that pollutant from a modification, would be 

temporary and impact no Class I area and no area where an applicable increment is known to be 

violated.

40 CFR 52.21(i)(3)

(4) The plan may provide that requirements equivalent to those contained in paragraphs (k), 

(m), and (o) of this section as they relate to any maximum allowable increase for a Class II area 

do not apply to a modification of a major stationary source that was in existence on March 1, 

1978, if the net increase in allowable emissions of each a regulated NSR pollutant from the 

modification after the application of best available control technology would be less than 50 tons 

per year.

40 CFR 52.21(i)(4)

(5) The plan may provide that the reviewing authority may exempt a proposed major stationary 

source or major modification from the requirements of paragraph (m) of this section, with 

respect to monitoring for a particular pollutant, if:

40 CFR 52.21(i)(5)

(i) The emissions increase of the pollutant from a new stationary source or the net emissions 

increase of the pollutant from a modification would cause, in any area, air quality impacts less 

than the following amounts:

( a ) Carbon monoxide—575 ug/m3, 8-hour average;

( b ) Nitrogen dioxide—14 ug/m3, annual average;

( c ) PM2.5–4 μg/m3, 24-hour average;

( d ) PM10–10 μg/m3

, 24-hour average;

40 CFR 52.21(i)(5)(i)
Requirements for a SIP Approved PSD Program in 40 CFR 51.166 and How those Requirements are met by 

Imperial Rule 904, Placer Rule 518, and Yolo-Solano Rule 3.24

Page 28of 51

( e ) Sulfur dioxide—13 ug/m3, 24-hour average;

( f ) Ozone;1

1 No de minimis air quality level is provided for ozone. However, any net emissions increase 

of 100 tons per year or more of volatile organic compounds or nitrogen oxides subject to PSD 

would be required to perform an ambient impact analysis, including the gathering of air 

quality data.

( g ) Lead—0.1 μg/m3, 3-month average.

( h ) Fluorides—0.25 μg/m3, 24-hour average;

( i ) Total reduced sulfur—10 μg/m3, 1-hour average

( j ) Hydrogen sulfide—0.2 μg/m3, 1-hour average;

( k ) Reduced sulfur compounds—10 μg/m3, 1-hour average; or

(ii) The concentrations of the pollutant in the area that the source or modification would affect 

are less than the concentrations listed in paragraph (i)(5)(i) of this section; or

40 CFR 52.21(i)(5)(ii)

(iii) The pollutant is not listed in paragraph (i)(5)(i) of this section. 40 CFR 52.21(i)(5)(iii)

(6) If EPA approves a plan revision under 40 CFR 51.166 as in effect before August 7, 1980, any 

subsequent revision which meets the requirements of this section may contain transition 

provisions which parallel the transition provisions of 40 CFR 52.21(i)(9), (i)(10) and (m)(1)(v) as 

in effect on that date, which provisions relate to requirements for best available control 

technology and air quality analyses. Any such subsequent revision may not contain any transition 

provision which in the context of the revision would operate any less stringently than would its 

counterpart in 40 CFR 52.21.

(7) If EPA approves a plan revision under §51.166 as in effect [before July 31, 1987], any 

subsequent revision which meets the requirements of this section may contain transition 

provisions which parallel the transition provisions of §52.21 (i)(11), and (m)(1) (vii) and (viii) of 

this chapter as in effect on that date, these provisions being related to monitoring requirements 

for particulate matter. Any such subsequent revision may not contain any transition provision 

which in the context of the revision would operate any less stringently than would its counterpart 

in §52.21 of this chapter.

(8) The plan may provide that the permitting requirements equivalent to those contained in 

paragraph (k)(1)(ii) of this section do not apply to a stationary source or modification with 

respect to any maximum allowable increase for nitrogen oxides if the owner or operator of the 

source or modification submitted an application for a permit under the applicable permit program 

approved or promulgated under the Act before the provisions embodying the maximum allowable 

increase took effect as part of the plan and the permitting authority subsequently determined 

that the application as submitted before that date was complete.

40 CFR 52.21(i)(9)

40 CFR 52.21(i)(1)(i-v, ixx) and 40 CFR 52.21(i)(6-

8). Rule 3.24 excludes 

these provisions which 

are not necessary for a 

PSD program
Requirements for a SIP Approved PSD Program in 40 CFR 51.166 and How those Requirements are met by 

Imperial Rule 904, Placer Rule 518, and Yolo-Solano Rule 3.24

Page 29of 51

(9) The plan may provide that the permitting requirements equivalent to those contained in 

paragraph (k)(1)(ii) of this section shall not apply to a stationary source or modification with 

respect to any maximum allowable increase for PM–10 if (i) the owner or operator of the source 

or modification submitted an application for a permit under the applicable permit program 

approved under the Act before the provisions embodying the maximum allowable increases for 

PM–10 took effect as part of the plan, and (ii) the permitting authority subsequently determined 

that the application as submitted before that date was complete. Instead, the applicable 

requirements equivalent to paragraph (k)(1)(ii) shall apply with respect to the maximum 

allowable increases for TSP as in effect on the date the application was submitted.

40 CFR 52.21(i)(10)

(j) Control 

technology review

(j) Control technology review. The plan shall provide that:

(1) A major stationary source or major modification shall meet each applicable emissions 

limitation under the State Implementation Plan and each applicable emission standards and 

standard of performance under 40 CFR parts 60 and 61.

(2) A new major stationary source shall apply best available control technology for each a 

regulated NSR pollutant that it would have the potential to emit in significant amounts.

(3) A major modification shall apply best available control technology for each a regulated NSR 

pollutant for which it would be a significant net emissions increase at the source. This 

requirement applies to each proposed emissions unit at which a net emissions increase in the 

pollutant would occur as a result of a physical change or change in the method of operation in the 

unit.

(4) For phased construction projects, the determination of best available control technology shall 

be reviewed and modified as appropriate at the least reasonable time which occurs no later than 

18 months prior to commencement of construction of each independent phase of the project. At 

such time, the owner or operator of the applicable stationary source may be required to 

demonstrate the adequacy of any previous determination of best available control technology for 

the source.

(k) Source impact 

analysis

(k) Source impact analysis — 40 CFR 52.21(k)

(1) Required demonstration. The plan shall provide that the owner or operator of the proposed 

source or modification shall demonstrate that allowable emission increases from the proposed 

source or modification, in conjunction with all other applicable emissions increases or reduction 

(including secondary emissions), would not cause or contribute to air pollution in violation of:

40 CFR 52.21(k)(1)

(i) Any national ambient air quality standard in any air quality control region; or 40 CFR 52.21(k)(1)(i)

(ii) Any applicable maximum allowable increase over the baseline concentration in any area. 40 CFR 52.21(k)(1)(ii)

40 CFR 52.21(j)
Requirements for a SIP Approved PSD Program in 40 CFR 51.166 and How those Requirements are met by 

Imperial Rule 904, Placer Rule 518, and Yolo-Solano Rule 3.24

Page 30of 51

(2) Significant impact levels. The plan may provide that, 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:

40 CFR 52.21(k)(2) - As 

discussed in the TSD, 

Imperial County APCD 

(Rule 904) and Placer 

County APCD (Rule 518) 

interprets these 

provisions consistent with 

EPA's 2010 preamble to 

this rulemaking - see 75 

FR 64864 on October 20, 

2010. Yolo-Solano Rule 

3.24 does not adopt this 

provision, which is not a 

required provisions for a 

PSD program.

See Table 2 below.

(l) Air quality models (l) Air quality models. The plan shall provide for procedures which specify that— 40 CFR 52.21(l)

(1) All applications of air quality modeling involved in this subpart shall be based on the 

applicable models, data bases, and other requirements specified in appendix W of this part 

(Guideline on Air Quality Models).

40 CFR 52.21(l)(1) 

(2) Where an air quality model specified in appendix W of this part (Guideline on Air Quality 

Models) is inappropriate, the model may be modified or another model substituted. Such a 

modification or substitution of a model may be made on a case-by-case basis or, where 

appropriate, on a generic basis for a specific State program. Written approval of the 

Administrator must be obtained for any modification or substitution. In addition, use of a 

modified or substituted model must be subject to notice and opportunity for public comment 

under procedures set forth in §51.102.

40 CFR 52.21(l)(2) - 

Rules 904, 518, and 3.24 

revise the term 

"Administrator" in 40 CFR 

52.21(l)(2) to mean the 

"Federal Administator" 

instead of the APCO as 

required by 51.166.

(m) Air quality 

analysis

(m) Air quality analysis — 40 CFR 52.21(m)

(1) Preapplication analysis. 40 CFR 52.21(m)(1)

(i) The plan shall provide that any application for a permit under regulations approved pursuant 

to this section shall contain an analysis of ambient air quality in the area that the major 

stationary source or major modification would affect for each of the following pollutants:

40 CFR 52.21(m)(1)(i)

( a ) For the source, each pollutant that it would have the potential to emit in a significant 

amount;

40 CFR 

52.21(m)(1)(i)(a )

( b ) For the modification, each pollutant for which it would result in a significant net 

emissions increase.

40 CFR 

52.21(m)(1)(i)(b )

(ii) The plan shall provide that, with respect to any such pollutant for which no National 

Ambient Air Quality Standard exists, the analysis shall contain such air quality monitoring data 

as the reviewing authority determines is necessary to assess ambient air quality for that 

pollutant in any area that the emissions of that pollutant would affect.

40 CFR 52.21(m)(1)(ii)
Requirements for a SIP Approved PSD Program in 40 CFR 51.166 and How those Requirements are met by 

Imperial Rule 904, Placer Rule 518, and Yolo-Solano Rule 3.24

Page 31of 51

(iii) The plan shall provide that with respect to any such pollutant (other than nonmethane 

hydrocarbons) for which such a standard does exist, the analysis shall contain continuous air 

quality monitoring data gathered for purposes of determining whether emissions of that 

pollutant would cause or contribute to a violation of the standard or any maxiumum allowable 

increase.

40 CFR 52.21(m)(1)(iii)

(iv) The plan shall provide that, in general, the continuous air monitoring data that is required 

shall have been gathered over a period of one year and shall represent the year preceding 

receipt of the application, except that, if the reviewing authority determines that a complete 

and adequate analysis can be accomplished with monitoring data gathered over a period 

shorter than one year (but not to be less than four months), the data that is required shall have 

been gathered over at least that shorter period.

40 CFR 52.21(m)(1)(iv)

(v) The plan may provide that the owner or operator of a proposed major stationary source or 

major modification of volatile organic compounds who satisfies all conditions of 40 CFR part 51 

appendix S, section IV may provide postapproval monitoring data for ozone in lieu of providing 

preconstruction data as required under paragraph (m)(1) of this section.

40 CFR 52.21(m)(1)(vi)

(2) Post-construction monitoring. The plan shall provide that the owner or operator of a major 

stationary source or major modification shall, after construction of the stationary source or 

modification, conduct such ambient monitoring as the reviewing authority determines is 

necessary to determine the effect emissions from the stationary source or modification may 

have, or are having, on air quality in any area.

40 CFR 52.21(m)(2)

(3) Operation of monitoring stations. The plan shall provide that the owner or operator of a 

major stationary source or major modification shall meet the requirements of appendix B to part 

58 of this chapter during the operation of monitoring stations for purposes of satisfying 

paragraph (m) of this section.

40 CFR 52.21(m)(3)

(n) Source 

information

(n) Source information. 40 CFR 52.21(n)

(1) The plan shall provide that the owner or operator of a proposed source or modification shall 

submit all information necessary to perform any analysis or make any determination required 

under procedures established in accordance with this section.

40 CFR 52.21(n)

(2) The plan may provide that such information shall include: 40 CFR 52.21(n)(1)

(i) A description of the nature, location, design capacity, and typical operating schedule of the 

source or modification, including specifications and drawings showing its design and plant 

layout;

40 CFR 52.21(n)(1)(i)

(ii) A detailed schedule for construction of the source or modification; 40 CFR 52.21(n)(1)(ii)

(iii) A detailed description as to what system of continuous emission reduction is planned by the 

source or modification, emission estimates, and any other information as necessary to 

determine that best available control technology as applicable would be applied;

40 CFR 52.21(n)(1)(iii)

(3) The plan shall provide that upon request of the State, the owner or operator shall also 

provide information on:

40 CFR 52.21(n)(2)

(i) The air quality impact of the source or modification, including meteorological and 

topographical data necessary to estimate such impact; and

40 CFR 52.21(n)(2)(i)
Requirements for a SIP Approved PSD Program in 40 CFR 51.166 and How those Requirements are met by 

Imperial Rule 904, Placer Rule 518, and Yolo-Solano Rule 3.24

Page 32of 51

(ii) The air quality impacts and the nature and extent of any or all general commercial, 

residential, industrial, and other growth which has occurred since August 7, 1977, in the area 

the source or modification would affect.

40 CFR 52.21(n)(2)(ii)

(o) Additional impact 

analyses

(o) Additional impact analyses. The plan shall provide that— 40 CFR 52.21(o)

(1) The owner or operator shall provide an analysis of the impairment to visibility, soils, and 

vegetation that would occur as a result of the source or modification and general commercial, 

residential, industrial, and other growth associated with the source or modification. The owner or 

operator need not provide an analysis of the impact on vegetation having no significant 

commercial or recreational value.

40 CFR 52.21(o)(1) and 

(3)

(2) The owner or operator shall provide an analysis of the air quality impact projected for the 

area as a result of general commercial, residential, industrial, and other growth associated with 

the source or modification.

40 CFR 52.21(o)(2)

(p) Sources impacting 

Federal Class I 

areas

(p) Sources impacting Federal Class I areas—additional requirements — 40 CFR 52.21(p)

(1) 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.

Section VII of Rule 210.4

(2) Federal Land Manager. The Federal Land Manager and the Federal official charged with direct 

responsibility for management of Class I lands have an affirmative responsibility to protect the air 

quality related values (including visibility) of any such lands and to consider, in consultation with 

the Administrator, whether a proposed source or modification would have an adverse impact on 

such values.

40 CFR 52.21(p)(2) - 

Rules 904, 518, and 3.24 

revise the term 

"Administrator" in 40 CFR 

52.21(b)(50)(i) to mean 

the "Federal 

Administator" instead of 

the APCO as required by 

51.166.

(3) Denial—impact on air quality related values. The plan shall provide a mechanism whereby a 

Federal Land Manager of any such lands may present to the State, after the reviewing authority's 

preliminary determination required under procedures developed in accordance with paragraph (r) 

of this section, a demonstration that the emissions from the proposed source or modification 

would have an adverse impact on the air quality-related values (including visibility) of any 

Federal mandatory Class I lands, notwithstanding that the change in air quality resulting from 

emissions from such source or modification would not cause or contribute to concentrations 

which would exceed the maximum allowable increases for a Class I area. If the State concurs 

with such demonstration, the reviewing authority shall not issue the permit.

40 CFR 52.21(p)(3) and 

(4) and 40 CFR 

52.21(b)(29), which 

defines "adverse impact 

on visibility".
Requirements for a SIP Approved PSD Program in 40 CFR 51.166 and How those Requirements are met by 

Imperial Rule 904, Placer Rule 518, and Yolo-Solano Rule 3.24

Page 33of 51

(4) Class I Variances. The plan may provide that the owner or operator of a proposed source or 

modification may demonstrate to the Federal Land Manager that the emissions from such source 

would have no adverse impact on the air quality related values of such lands (including visibility), 

notwithstanding that the change in air quality resulting from emissions from such source or 

modification would cause or contribute to concentrations which would exceed the maximum 

allowable increases for a Class I area. If the Federal land manager concurs with such 

demonstration and so certifies to the State, the reviewing authority may: Provided, That 

applicable requirements are otherwise met, issue the permit with such emission limitations as 

may be necessary to assure that emissions of sulfur dioxide, PM2.5, PM10, and nitrogen oxides 

would not exceed the following maximum allowable increases over minor source baseline 

concentration for such pollutants:

40 CFR 52.21(p)(5) and 

40 CFR 52.21(b)(29)

See Table 3 below.

(5) Sulfur dioxide variance by Governor with Federal Land Manager's concurrence. The plan may 

provide that—

(i) The owner or operator of a proposed source or modification which cannot be approved 

under procedures developed pursuant to paragraph (q)(4) of this section may demonstrate to 

the Governor that the source or modification cannot be constructed by reason of any maximum 

allowable increase for sulfur dioxide for periods of twenty-four hours or less applicable to any 

Class I area and, in the case of Federal mandatory Class I areas, that a variance under this 

clause would not adversely affect the air quality related values of the area (including visibility);

(ii) The Governor, after consideration of the Federal Land Manager's recommendation (if any) 

and subject to his concurrence, may grant, after notice and an opportunity for a public hearing, 

a variance from such maximum allowable increase; and

(iii) If such variance is granted, the reviewing authority may issue a permit to such source or 

modification in accordance with provisions developed pursuant to paragraph (q)(7) of this 

section: Provided, That the applicable requirements of the plan are otherwise met.

(6) Variance by the Governor with the President's concurrence. The plan may provide that—

(i) The recommendations of the Governor and the Federal Land Manager shall be transferred to 

the President in any case where the Governor recommends a variance in which the Federal 

Land Manager does not concur;

(ii) The President may approve the Governor's recommendation if he finds that such variance is 

in the national interest; and

(iii) If such a variance is approved, the reviewing authority may issue a permit in accordance 

with provisions developed pursuant to the requirements of paragraph (q)(7) of this section: 

Provided, That the applicable requirements of the plan are otherwise met.

Rules 904, 518, and 3.24 

exclude these provisions 

which are found at 40 

CFR 52.21(p)(6) and are 

not required for a PSD 

program, as 51.166 

states the "plan may".

Rules 904, 518, and 3.24 

exclude these provisions 

which are found at 40 

CFR 52.21(p)(7) and are 

not required for a PSD 

program, as 51.166 

states the "plan may".
Requirements for a SIP Approved PSD Program in 40 CFR 51.166 and How those Requirements are met by 

Imperial Rule 904, Placer Rule 518, and Yolo-Solano Rule 3.24

Page 34of 51

(7) Emission limitations for Presidential or gubernatorial variance. The plan shall provide that in 

the case of a permit issued under procedures developed pursuant to paragraph (q) (5) or (6) of 

this section, the source or modification shall comply with emission limitations as may be 

necessary to assure that emissions of sulfur dioxide from the source or modification would not 

(during any day on which the otherwise applicable maximum allowable increases are exceeded) 

cause or contribute to concentrations which would exceed the following maximum allowable 

increases over the baseline concentration and to assure that such emissions would not cause or 

contribute to concentrations which exceed the otherwise applicable maximum allowable increases 

for periods of exposure of 24 hours or less for more than 18 days, not necessarily consecutive, 

during any annual period:

Rules 904, 518, and 3.24 

exclude these provisions 

which are found at 40 

CFR 52.21(p)(8), which 

are not required for a 

PSD program as 51.166 

states the "plan may".

See Table 4 below.

(q) Public 

participation

(q) Public participation. The plan shall provide that—

(1) The reviewing authority shall notify all applicants within a specified time period as to the 

completeness of the application or any deficiency in the application or information submitted. In 

the event of such a deficiency, the date of receipt of the application shall be the date on which 

the reviewing authority received all required information.

EKAPCD 210.1, ICAPCD 

Rule 206, PCAPCD Rule 

502, and YSAQMD Rule 

3.24, Section 401.2

(2) Within one year after receipt of a complete application, the reviewing authority shall: EKAPCD 210.1, ICAPCD 

Rule 206, PCAPCD Rule 

502, and YSAQMD Rule 

3.24, Section 401.3

(i) Make a preliminary determination whether construction should be approved, approved with 

conditions, or disapproved.

Rule 904, Section F..1; 

Rule 518, Section 401.1; 

and Rule 3.24, Section 

402.1

(ii) 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, and a copy or summary of other materials, if any, considered in making the 

preliminary determination.

Rule 904, Section F.2; 

Rule 518, Section 401.2; 

and Rule 3.24, Section 

402.2

(iii) Notify the public, by advertisement in a newspaper of general circulation in each region in 

which the proposed source would be constructed, of the application, the preliminary 

determination, the degree of increment consumption that is expected from the source or 

modification, and of the opportunity for comment at a public hearing as well as written public 

comment.

Rule 904, Section F.3; 

Rule 518, Section 401.3; 

and Rule 3.24, Section 

402.3

(iv) Send a copy of the notice of public comment to the applicant, the Administrator and to 

officials and agencies having cognizance over the location where the proposed construction 

would occur as follows: Any other State or local air pollution control agencies, the chief 

executives of the city and county where the source would be located; any comprehensive 

regional land use planning agency, and any State, Federal Land Manager, or Indian Governing 

body whose lands may be affected by emissions from the source or modification.

Rule 904, Section F.4; 

Rule 518, Section 401.4; 

and Rule 3.24, Section 

402.4

(v) Provide opportunity for a public hearing for interested persons to appear and submit written 

or oral comments on the air quality impact of the source, alternatives to it, the control 

technology required, and other appropriate considerations.

Rule 904, Section F.5; 

Rule 518, Section 401.5; 

and Rule 3.24, Section 

402.5
Requirements for a SIP Approved PSD Program in 40 CFR 51.166 and How those Requirements are met by 

Imperial Rule 904, Placer Rule 518, and Yolo-Solano Rule 3.24

Page 35of 51

(vi) Consider all written comments submitted within a time specified in the notice of public 

comment and all comments received at any public hearing(s) in making a final decision on the 

approvability of the application. The reviewing authority shall make all comments available for 

public inspection in the same locations where the reviewing authority made available 

preconstruction information relating to the proposed source or modification.

Rule 904, Section F.6; 

Rule 518, Section 401.6; 

and Rule 3.24, Section 

402.6

(vii) Make a final determination whether construction should be approved, approved with 

conditions, or disapproved.

Rule 904, Section F.7; 

Rule 518, Section 401.7; 

and Rule 3.24, Section 

402.7

(viii) Notify the applicant in writing of the final determination and make such notification 

available for public inspection at the same location where the reviewing authority made 

available preconstruction information and public comments relating to the source.

Rule 904, Section F.8; 

Rule 518, Section 401.8; 

and Rule 3.24, Section 

402.8

(r ) Source obligation (r) Source obligation. 40 CFR 52.21(r )

(1) The plan shall include enforceable procedures to provide that approval to construct shall not 

relieve any owner or operator of the responsibility to comply fully with applicable provisions of 

the plan and any other requirements under local, State or Federal law.

40 CFR 52.21(r)(1-3)

(2) The plan shall provide that at such time that a particular source or modification becomes a 

major stationary source or major modification solely by virtue of a relaxation in any enforceable 

limitation which was established after August 7, 1980, on the capacity of the source or 

modification otherwise to emit a pollutant, such as a restriction on hours of operation, then the 

requirements of paragraphs (j) through (s) of this section shall apply to the source or 

modification as though construction had not yet commenced on the source or modification.

40 CFR 52.21(r)(4)

(3)–(5) [Reserved]

(6) Each plan shall provide that, except as otherwise provided in paragraph (r)(6)(vi) of this 

section, the following specific provisions apply with respect to any regulated NSR pollutant 

emitted from projects at existing emissions units at a major stationary source (other than 

projects at a source with a PAL) in circumstances where there is a reasonable possibility, within 

the meaning of paragraph (r)(6)(vi) of this section, that a project that is not a part of a major 

modification may result in a significant emissions increase of such pollutant, and the owner or 

operator elects to use the method specified in paragraphs (b)(40)(ii)( a ) through ( c ) of this 

section for calculating projected actual emissions. Deviations from these provisions will be 

approved only if the 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 (r)(6)(i) through (vi) of this section.

40 CFR 52.21(r)(6)

(i) Before beginning actual construction of the project, the owner or operator shall document 

and maintain a record of the following information:

40 CFR 52.21(r)(6)(i)

( a ) A description of the project; 40 CFR 52.21(r)(6)(i)(a )

( b ) Identification of the emissions unit(s) whose emissions of a regulated NSR pollutant 

could be affected by the project; and

40 CFR 52.21(r)(6)(i)(b )
Requirements for a SIP Approved PSD Program in 40 CFR 51.166 and How those Requirements are met by 

Imperial Rule 904, Placer Rule 518, and Yolo-Solano Rule 3.24

Page 36of 51

( c ) A description of the applicability test used to determine that the project is not a major 

modification for any regulated NSR pollutant, including the baseline actual emissions, the 

projected actual emissions, the amount of emissions excluded under paragraph (b)(40)(ii)( c 

) of this section and an explanation for why such amount was excluded, and any netting 

calculations, if applicable.

40 CFR 52.21(r)(6)(i)(c )

(ii) If the emissions unit is an existing electric utility steam generating unit, before beginning 

actual construction, the owner or operator shall provide a copy of the information set out in 

paragraph (r)(6)(i) of this section to the reviewing authority. Nothing in this paragraph 

(r)(6)(ii) shall be construed to require the owner or operator of such a unit to obtain any 

determination from the reviewing authority before beginning actual construction.

40 CFR 52.21(r)(6)(ii)

(iii) The owner or operator shall monitor the emissions of any regulated NSR pollutant that 

could increase as a result of the project and that is emitted by any emissions unit identified in 

paragraph (r)(6)(i)( b ) of this section; and calculate and maintain a record of the annual 

emissions, in tons per year on a calendar year basis, for a period of 5 years following 

resumption of regular operations after the change, or for a period of 10 years following 

resumption of regular operations after the change if the project increases the design capacity 

or potential to emit of that regulated NSR pollutant at such emissions unit.

40 CFR 52.21(r)(6)(iii)

(iv) If the unit is an existing electric utility steam generating unit, the owner or operator shall 

submit a report to the reviewing authority within 60 days after the end of each year during 

which records must be generated under paragraph (r)(6)(iii) of this section setting out the 

unit's annual emissions during the calendar year that preceded submission of the report.

40 CFR 52.21(r)(6)(iv)

(v) If the unit is an existing unit other than an electric utility steam generating unit, the owner 

or operator shall submit a report to the reviewing authority if the annual emissions, in tons per 

year, from the project identified in paragraph (r)(6)(i) of this section, exceed the baseline 

actual emissions (as documented and maintained pursuant to paragraph (r)(6)(i)( c ) of this 

section) by a significant amount (as defined in paragraph (b)(23) of this section) for that 

regulated NSR pollutant, and if such emissions differ from the preconstruction projection as 

documented and maintained pursuant to paragraph (r)(6)(i)( c ) of this section. Such report 

shall be submitted to the reviewing authority within 60 days after the end of such year. The 

report shall contain the following:

40 CFR 52.21(r)(6)(v)

( a ) The name, address and telephone number of the major stationary source; 40 CFR 52.21(r)(6)(v)(a )

( b ) The annual emissions as calculated pursuant to paragraph (r)(6)(iii) of this section; and 40 CFR 52.21(r)(6)(v)(b )

( c ) Any other information that the owner or operator wishes to include in the report (e.g., 

an explanation as to why the emissions differ from the preconstruction projection).

40 CFR 52.21(r)(6)(v)(c )

(vi) A “reasonable possibility” under paragraph (r)(6) of this section occurs when the owner or 

operator calculates the project to result in either:

40 CFR 52.21(r)(6)(vi)

( a ) A projected actual emissions increase of at least 50 percent of the amount that is a 

“significant emissions increase,” as defined under paragraph (b)(39) of this section (without 

reference to the amount that is a significant net emissions increase), for the regulated NSR 

pollutant; or

40 CFR 

52.21(r)(6)(vi)(a )
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( b ) A projected actual emissions increase that, added to the amount of emissions excluded 

under paragraph (b)(40)(ii)( c ), sums to at least 50 percent of the amount that is a 

“significant emissions increase,” as defined under paragraph (b)(39) of this section (without 

reference to the amount that is a significant net emissions increase), for the regulated NSR 

pollutant. For a project for which a reasonable possibility occurs only within the meaning of 

paragraph (r)(6)(vi)( b ) of this section, and not also within the meaning of paragraph 

(a)(6)(vi)( a ) of this section, then provisions (a)(6)(ii) through (v) do not apply to the 

project.

40 CFR 

52.21(r)(6)(vi)(b )

(7) Each plan shall provide that the owner or operator of the source shall make the information 

required to be documented and maintained pursuant to paragraph (r)(6) of this section available 

for review upon request for inspection by the reviewing authority or the general public pursuant 

to the requirements contained in §70.4(b)(3)(viii) of this chapter.

40 CFR 52.21(r)(7)

(s) Innovative control 

technology

(s) Innovative control technology. 

(1) The plan may provide that an owner or operator of a proposed major stationary source or 

major modification may request the reviewing authority to approve a system of innovative 

control technology.

(2) The plan may provide that the reviewing authority may, with the consent of the Governor(s) 

of other affected State(s), determine that the source or modification may employ a system of 

innovative control technology, if:

(i) The proposed control system would not cause or contribute to an unreasonable risk to public 

health, welfare, or safety in its operation or function;

(ii) The owner or operator agrees to achieve a level of continuous emissions reduction 

equivalent to that which would have been required under paragraph (j)(2) of this section, by a 

date specified by the reviewing authority. Such date shall not be later than 4 years from the 

time of startup or 7 years from permit issuance;

(iii) The source or modification would meet the requirements equivalent to those in paragraphs 

(j) and (k) of this section, based on the emissions rate that the stationary source employing the 

system of innovative control technology would be required to meet on the date specified by the 

reviewing authority;

(iv) The source or modification would not before the date specified by the reviewing authority:

( a ) Cause or contribute to any violation of an applicable national ambient air quality standard; 

or

( b ) Impact any area where an applicable increment is known to be violated;

(v) All other applicable requirements including those for public participation have been met.

(vi) The provisions of paragraph (p) of this section (relating to Class I areas) have been 

satisfied with respect to all periods during the life of the source or modification.

(3) The plan shall provide that the reviewing authority shall withdraw any approval to employ a 

system of innovative control technology made under this section, if:

(i) The proposed system fails by the specified date to achieve the required continuous 

emissions reduction rate; or

Rules 904, 518, and 3.24 

exclude this definition. - 

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(ii) The proposed system fails before the specified date so as to contribute to an unreasonable 

risk to public health, welfare, or safety; or

(iii) The reviewing authority decides at any time that the proposed system is unlikely to achieve 

the required level of control or to protect the public health, welfare, or safety.

(4) The plan may provide that if a source or modification fails to meet the required level of 

continuous emissions reduction within the specified time period, or if the approval is withdrawn in 

accordance with paragraph (s)(3) of this section, the reviewing authority may allow the source or 

modification up to an additional 3 years to meet the requirement for the application of best 

available control technology through use of a demonstrated system of control.

(t)-(v) (t)–(v) [Reserved]

(w) Actuals PALs (w) Actuals PALs. The plan shall provide for PALs according to the provisions in paragraphs 

(w)(1) through (15) of this section.

40 CFR 52.21(aa)

(1) Applicability. 

(i) The reviewing authority may approve the use of an actuals PAL for any existing major 

stationary source if the PAL meets the requirements in paragraphs (w)(1) through (15) of this 

section. The term “PAL” shall mean “actuals PAL” throughout paragraph (w) of this section.

(ii) Any physical change in or change in the method of operation of a major stationary source 

that maintains its total source-wide emissions below the PAL level, meets the requirements in 

paragraphs (w)(1) through (15) of this section, and complies with the PAL permit:

( a ) Is not a major modification for the PAL pollutant;

( b ) Does not have to be approved through the plan's major NSR program; and

( c ) Is not subject to the provisions in paragraph (r)(2) of this section (restrictions on 

relaxing enforceable emission limitations that the major stationary source used to avoid 

applicability of the major NSR program).

(iii) Except as provided under paragraph (w)(1)(ii)(c) of this section, a major stationary source 

shall continue to comply with all applicable Federal or State requirements, emission limitations, 

and work practice requirements that were established prior to the effective date of the PAL.

(2) Definitions. The plan shall use the definitions in paragraphs (w)(2)(i) through (xi) of this 

section for the purpose of developing and implementing regulations that authorize the use of 

actuals PALs consistent with paragraphs (w)(1) through (15) of this section. When a term is not 

defined in these paragraphs, it shall have the meaning given in paragraph (b) of this section or in 

the Act.

(i) Actuals PAL for a major stationary source means a PAL based on the baseline actual 

emissions (as defined in paragraph (b)(47) of this section) of all emissions units (as defined in 

paragraph (b)(7) of this section) at the source, that emit or have the potential to emit the PAL 

pollutant.

(ii) Allowable emissions means “allowable emissions” as defined in paragraph (b)(16) of this 

section, except as this definition is modified according to paragraphs (w)(2)(ii)( a ) and ( b ) of 

this section.

( a ) The allowable emissions for any emissions unit shall be calculated considering any 

emission limitations that are enforceable as a practical matter on the emissions unit's 

potential to emit.

40 CFR 52.21(aa)(1)

40 CFR 52.21(aa)(2)
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( b ) An emissions unit's potential to emit shall be determined using the definition in 

paragraph (b)(4) of this section, except that the words “or enforceable as a practical matter” 

should be added after “federally enforceable.”

(iii) Small emissions unit means an emissions unit that emits or has the potential to emit the 

PAL pollutant in an amount less than the significant level for that PAL pollutant, as defined in 

paragraph (b)(23) of this section or in the Act, whichever is lower.

(iv) Major emissions unit means:

( a ) Any emissions unit that emits or has the potential to emit 100 tons per year or more of 

the PAL pollutant in an attainment area; or

( b ) Any emissions unit that emits or has the potential to emit the PAL pollutant in an 

amount that is equal to or greater than the major source threshold for the PAL pollutant as 

defined by the Act for nonattainment areas. For example, in accordance with the definition of 

major stationary source in section 182(c) of the Act, an emissions unit would be a major 

emissions unit for VOC if the emissions unit is located in a serious ozone nonattainment area 

and it emits or has the potential to emit 50 or more tons of VOC per year.

(v) Plantwide applicability limitation (PAL) means an emission limitation expressed in tons per 

year, for a pollutant at a major stationary source, that is enforceable as a practical matter and 

established source-wide in accordance with paragraphs (w)(1) through (15) of this section.

(vi) PAL effective date generally means the date of issuance of the PAL permit. However, the 

PAL effective date for an increased PAL is the date any emissions unit that is part of the PAL 

major modification becomes operational and begins to emit the PAL pollutant.

(vii) PAL effective period means the period beginning with the PAL effective date and ending 10 

years later.

(viii) PAL major modification means, notwithstanding paragraphs (b)(2) and (b)(3) of this 

section (the definitions for major modification and net emissions increase), any physical change 

in or change in the method of operation of the PAL source that causes it to emit the PAL 

pollutant at a level equal to or greater than the PAL.

(ix) PAL permit means the major NSR permit, the minor NSR permit, or the State operating 

permit under a program that is approved into the plan, or the title V permit issued by the 

reviewing authority that establishes a PAL for a major stationary source.

(x) PAL pollutant means the pollutant for which a PAL is established at a major stationary 

source.

(xi) Significant emissions unit means an emissions unit that emits or has the potential to emit a 

PAL pollutant in an amount that is equal to or greater than the significant level (as defined in 

paragraph (b)(23) of this section or in the Act, whichever is lower) for that PAL pollutant, but 

less than the amount that would qualify the unit as a major emissions unit as defined in 

paragraph (w)(2)(iv) of this section.

(3) Permit application requirements. As part of a permit application requesting a PAL, the owner 

or operator of a major stationary source shall submit the following information in paragraphs 

(w)(3)(i) through (iii) of this section to the reviewing authority for approval.

40 CFR 52.21(aa)(3)
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(i) A list of all emissions units at the source designated as small, significant or major based on 

their potential to emit. In addition, the owner or operator of the source shall indicate which, if 

any, Federal or State applicable requirements, emission limitations, or work practices apply to 

each unit.

(ii) Calculations of the baseline actual emissions (with supporting documentation). Baseline 

actual emissions are to include emissions associated not only with operation of the unit, but 

also emissions associated with startup, shutdown, and malfunction.

(iii) The calculation procedures that the major stationary source owner or operator proposes to 

use to convert the monitoring system data to monthly emissions and annual emissions based 

on a 12-month rolling total for each month as required by paragraph (w)(13)(i) of this section.

(4) General requirements for establishing PALs. 

(i) The plan allows the reviewing authority to establish a PAL at a major stationary source, 

provided that at a minimum, the requirements in paragraphs (w)(4)(i)(a) through (g) of this 

section are met.

( a ) The PAL shall impose an annual emission limitation in tons per year, that is enforceable 

as a practical matter, for the entire major stationary source. For each month during the PAL 

effective period after the first 12 months of establishing a PAL, the major stationary source 

owner or operator shall show that the sum of the monthly emissions from each emissions unit 

under the PAL for the previous 12 consecutive months is less than the PAL (a 12-month 

average, rolled monthly). For each month during the first 11 months from the PAL effective 

date, the major stationary source owner or operator shall show that the sum of the preceding 

monthly emissions from the PAL effective date for each emissions unit under the PAL is less 

than the PAL.

( b ) The PAL shall be established in a PAL permit that meets the public participation 

requirements in paragraph (w)(5) of this section.

( c ) The PAL permit shall contain all the requirements of paragraph (w)(7) of this section.

( d ) The PAL shall include fugitive emissions, to the extent quantifiable, from all emissions 

units that emit or have the potential to emit the PAL pollutant at the major stationary source.

( e ) Each PAL shall regulate emissions of only one pollutant.

( f ) Each PAL shall have a PAL effective period of 10 years.

( g ) The owner or operator of the major stationary source with a PAL shall comply with the 

monitoring, recordkeeping, and reporting requirements provided in paragraphs (w)(12) 

through (14) of this section for each emissions unit under the PAL through the PAL effective 

period.

(ii) At no time (during or after the PAL effective period) are emissions reductions of a PAL 

pollutant that occur during the PAL effective period creditable as decreases for purposes of 

offsets under §51.165(a)(3)(ii) of this chapter unless the level of the PAL is reduced by the 

amount of such emissions reductions and such reductions would be creditable in the absence of 

the PAL.

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(5) Public participation requirements for PALs. PALs for existing major stationary sources shall be 

established, renewed, or increased, through a procedure that is consistent with §§51.160 and 

51.161 of this chapter. This includes the requirement that the reviewing authority provide the 

public with notice of the proposed approval of a PAL permit and at least a 30-day period for 

submittal of public comment. The reviewing authority must address all material comments before 

taking final action on the permit.

40 CFR 52.21(aa)(5)

(6) Setting the 10-year actuals PAL level. 

(i) Except as provided in paragraph (w)(6)(ii) of this section, the plan shall provide that the 

actuals PAL level for a major stationary source shall be established as the sum of the baseline 

actual emissions (as defined in paragraph (b)(47) of this section) of the PAL pollutant for each 

emissions unit at the source; plus an amount equal to the applicable significant level for the 

PAL pollutant under paragraph (b)(23) of this section or under the Act, whichever is lower. 

When establishing the actuals PAL level, for a PAL pollutant, only one consecutive 24-month 

period must be used to determine the baseline actual emissions for all existing emissions units. 

However, a different consecutive 24-month period may be used for each different PAL 

pollutant. Emissions associated with units that were permanently shut down after this 24-month 

period must be subtracted from the PAL level. The reviewing authority shall specify a reduced 

PAL level(s) (in tons/yr) in the PAL permit to become effective on the future compliance date(s) 

of any applicable Federal or State regulatory requirement(s) that the reviewing authority is 

aware of prior to issuance of the PAL permit. For instance, if the source owner or operator will 

be required to reduce emissions from industrial boilers in half from baseline emissions of 60 (ii) For newly constructed units (which do not include modifications to existing units) on which 

actual construction began after the 24-month period, in lieu of adding the baseline actual 

emissions as specified in paragraph (w)(6)(i) of this section, the emissions must be added to 

the PAL level in an amount equal to the potential to emit of the units.

(7) Contents of the PAL permit. The plan shall require that the PAL permit contain, at a 

minimum, the information in paragraphs (w)(7)(i) through (x) of this section.

(i) The PAL pollutant and the applicable source-wide emission limitation in tons per year.

(ii) The PAL permit effective date and the expiration date of the PAL (PAL effective period).

(iii) Specification in the PAL permit that if a major stationary source owner or operator applies 

to renew a PAL in accordance with paragraph (w)(10) of this section before the end of the PAL 

effective period, then the PAL shall not expire at the end of the PAL effective period. It shall 

remain in effect until a revised PAL permit is issued by the reviewing authority.

(iv) A requirement that emission calculations for compliance purposes include emissions from 

startups, shutdowns and malfunctions.

(v) A requirement that, once the PAL expires, the major stationary source is subject to the 

requirements of paragraph (w)(9) of this section.

(vi) The calculation procedures that the major stationary source owner or operator shall use to 

convert the monitoring system data to monthly emissions and annual emissions based on a 12-

month rolling total for each month as required by paragraph (w)(3)(i) of this section.

(vii) A requirement that the major stationary source owner or operator monitor all emissions 

units in accordance with the provisions under paragraph (w)(13) of this section.

40 CFR 52.21(aa)(6)

40 CFR 52.21(aa)(7)
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(viii) A requirement to retain the records required under paragraph (w)(13) of this section on 

site. Such records may be retained in an electronic format.

(ix) A requirement to submit the reports required under paragraph (w)(14) of this section by 

the required deadlines.

(x) Any other requirements that the reviewing authority deems necessary to implement and 

enforce the PAL.

(8) PAL effective period and reopening of the PAL permit. The plan shall require the information 

in paragraphs (w)(8)(i) and (ii) of this section.

(i) PAL effective period. The reviewing authority shall specify a PAL effective period of 10 

years.

(ii) Reopening of the PAL permit. 

( a ) During the PAL effective period, the plan shall require the reviewing authority to reopen 

the PAL permit to:

( 1 ) Correct typographical/calculation errors made in setting the PAL or reflect a more 

accurate determination of emissions used to establish the PAL;

( 2 ) Reduce the PAL if the owner or operator of the major stationary source creates 

creditable emissions reductions for use as offsets under §51.165(a)(3)(ii) of this chapter; 

and

( 3 ) Revise the PAL to reflect an increase in the PAL as provided under paragraph (w)(11) 

of this section.

( b ) The plan shall provide the reviewing authority discretion to reopen the PAL permit for 

the following:

( 1 ) Reduce the PAL to reflect newly applicable Federal requirements (for example, NSPS) 

with compliance dates after the PAL effective date;

( 2 ) Reduce the PAL consistent with any other requirement, that is enforceable as a 

practical matter, and that the State may impose on the major stationary source under the 

plan; and

( 3 ) Reduce the PAL if the reviewing authority determines that a reduction is necessary to 

avoid causing or contributing to a NAAQS or PSD increment violation, or to an adverse 

impact on an AQRV that has been identified for a Federal Class I area by a Federal Land 

Manager and for which information is available to the general public.

( c ) Except for the permit reopening in paragraph (w)(8)(ii)( a )( 1 ) of this section for the 

correction of typographical/calculation errors that do not increase the PAL level, all 

reopenings shall be carried out in accordance with the public participation requirements of 

paragraph (w)(5) of this section.

(9) Expiration of a PAL. Any PAL that is not renewed in accordance with the procedures in 

paragraph (w)(10) of this section shall expire at the end of the PAL effective period, and the 

requirements in paragraphs (w)(9)(i) through (v) of this section shall apply.

(i) Each emissions unit (or each group of emissions units) that existed under the PAL shall 

comply with an allowable emission limitation under a revised permit established according to 

the procedures in paragraphs (w)(9)(i)( a ) and ( b ) of this section.

40 CFR 52.21(aa)(8)

40 CFR 52.21(aa)(9)
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( a ) Within the time frame specified for PAL renewals in paragraph (w)(10)(ii) of this section, 

the major stationary source shall submit a proposed allowable emission limitation for each 

emissions unit (or each group of emissions units, if such a distribution is more appropriate as 

decided by the reviewing authority) by distributing the PAL allowable emissions for the major 

stationary source among each of the emissions units that existed under the PAL. If the PAL 

had not yet been adjusted for an applicable requirement that became effective during the PAL 

effective period, as required under paragraph (w)(10)(v) of this section, such distribution 

shall be made as if the PAL had been adjusted.

( b ) The reviewing authority shall decide whether and how the PAL allowable emissions will 

be distributed and issue a revised permit incorporating allowable limits for each emissions 

unit, or each group of emissions units, as the reviewing authority determines is appropriate.

(ii) Each emissions unit(s) shall comply with the allowable emission limitation on a 12-month 

rolling basis. The reviewing authority may approve the use of monitoring systems (source 

testing,emission factors, etc.) other than CEMS, CERMS, PEMS or CPMS to demonstrate 

compliance with the allowable emission limitation.

(iii) Until the reviewing authority issues the revised permit incorporating allowable limits for 

each emissions unit, or each group of emissions units, as required under paragraph (w)(9)(i)( 

b ) of this section, the source shall continue to comply with a source-wide, multi-unit emissions 

cap equivalent to the level of the PAL emission limitation.

(iv) Any physical change or change in the method of operation at the major stationary source 

will be subject to major NSR requirements if such change meets the definition of major 

modification in paragraph (b)(2) of this section.

(v) The major stationary source owner or operator shall continue to comply with any State or 

Federal applicable requirements (BACT, RACT, NSPS, etc.) that may have applied either during 

the PAL effective period or prior to the PAL effective period except for those emission 

limitations that had been established pursuant to paragraph (r)(2) of this section, but were 

eliminated by the PAL in accordance with the provisions in paragraph (w)(1)(ii)(c) of this 

section.

(10) Renewal of a PAL. 

(i) The reviewing authority shall follow the procedures specified in paragraph (w)(5) of this 

section in approving any request to renew a PAL for a major stationary source, and shall 

provide both the proposed PAL level and a written rationale for the proposed PAL level to the 

public for review and comment. During such public review, any person may propose a PAL level 

for the source for consideration by the reviewing authority.

(ii) Application deadline. The plan shall require that a major stationary source owner or 

operator shall submit a timely application to the reviewing authority to request renewal of a 

PAL. A timely application is one that is submitted at least 6 months prior to, but not earlier than 

18 months from, the date of permit expiration. This deadline for application submittal is to 

ensure that the permit will not expire before the permit is renewed. If the owner or operator of 

a major stationary source submits a complete application to renew the PAL within this time 

period, then the PAL shall continue to be effective until the revised permit with the renewed 

PAL is issued.

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(iii) Application requirements. The application to renew a PAL permit shall contain the 

information required in paragraphs (w)(10)(iii) ( a ) through ( d ) of this section.

( a ) The information required in paragraphs (w)(3)(i) through (iii) of this section.

( b ) A proposed PAL level.

( c ) The sum of the potential to emit of all emissions units under the PAL (with supporting 

documentation).

( d ) Any other information the owner or operator wishes the reviewing authority to consider 

in determining the appropriate level for renewing the PAL.

(iv) PAL adjustment. In determining whether and how to adjust the PAL, the reviewing 

authority shall consider the options outlined in paragraphs (w)(10)(iv) ( a ) and ( b ) of this 

section. However, in no case may any such adjustment fail to comply with paragraph 

(w)(10)(iv)( c ) of this section.

( a ) If the emissions level calculated in accordance with paragraph (w)(6) of this section is 

equal to or greater than 80 percent of the PAL level, the reviewing authority may renew the 

PAL at the same level without considering the factors set forth in paragraph (w)(10)(iv)( b ) 

of this section; or

( b ) The reviewing authority may set the PAL at a level that it determines to be more 

representative of the source's baseline actual emissions, or that it determines to be 

appropriate considering air quality needs, advances in control technology, anticipated 

economic growth in the area, desire to reward or encourage the source's voluntary emissions 

reductions, or other factors as specifically identified by the reviewing authority in its written 

rationale.

( c ) Notwithstanding paragraphs (w)(10)(iv) ( a ) and ( b ) of this section:

( 1 ) If the potential to emit of the major stationary source is less than the PAL, the 

reviewing authority shall adjust the PAL to a level no greater than the potential to emit of 

the source; and

( 2 ) The reviewing authority shall not approve a renewed PAL level higher than the current 

PAL, unless the major stationary source has complied with the provisions of paragraph 

(w)(11) of this section (increasing a PAL).

(v) If the compliance date for a State or Federal requirement that applies to the PAL source 

occurs during the PAL effective period, and if the reviewing authority has not already adjusted 

for such requirement, the PAL shall be adjusted at the time of PAL permit renewal or title V 

permit renewal, whichever occurs first.

(11) Increasing a PAL during the PAL effective period. 

(i) The plan shall require that the reviewing authority may increase a PAL emission limitation 

only if the major stationary source complies with the provisions in paragraphs (w)(11)(i) ( a ) 

through ( d ) of this section.

( a ) The owner or operator of the major stationary source shall submit a complete 

application to request an increase in the PAL limit for a PAL major modification. Such 

application shall identify the emissions unit(s) contributing to the increase in emissions so as 

to cause the major stationary source's emissions to equal or exceed its PAL.

40 CFR 52.21(aa)(11)
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( b ) As part of this application, the major stationary source owner or operator shall 

demonstrate that the sum of the baseline actual emissions of the small emissions units, plus 

the sum of the baseline actual emissions of the significant and major emissions units 

assuming application of BACT equivalent controls, plus the sum of the allowable emissions of 

the new or modified emissions unit(s), exceeds the PAL. The level of control that would result 

from BACT equivalent controls on each significant or major emissions unit shall be determined 

by conducting a new BACT analysis at the time the application is submitted, unless the 

emissions unit is currently required to comply with a BACT or LAER requirement that was 

established within the preceding 10 years. In such a case, the assumed control level for that 

emissions unit shall be equal to the level of BACT or LAER with which that emissions unit 

must currently comply.

( c ) The owner or operator obtains a major NSR permit for all emissions unit(s) identified in 

paragraph (w)(11)(i)( a ) of this section, regardless of the magnitude of the emissions 

increase resulting from them (that is, no significant levels apply). These emissions unit(s) 

shall comply with any emissions requirements resulting from the major NSR process (for 

example, BACT), even though they have also become subject to the PAL or continue to be 

subject to the PAL.

( d ) The PAL permit shall require that the increased PAL level shall be effective on the day 

any emissions unit that is part of the PAL major modification becomes operational and begins 

to emit the PAL pollutant.

(ii) The reviewing authority shall calculate the new PAL as the sum of the allowable emissions 

for each modified or new emissions unit, plus the sum of the baseline actual emissions of the 

significant and major emissions units (assuming application of BACT equivalent controls as 

determined in accordance with paragraph (w)(11)(i)( b ) of this section), plus the sum of the 

baseline actual emissions of the small emissions units.

(iii) The PAL permit shall be revised to reflect the increased PAL level pursuant to the public 

notice requirements of paragraph (w)(5) of this section.

(12) Monitoring requirements for PALs —

(i) General requirements. emissions of the PAL pollutant in terms of mass per unit of time. Any 

monitoring system authorized for use in the PAL permit must be based on sound science and 

meet generally acceptable scientific procedures for data quality and manipulation. Additionally, 

the information generated by such system must meet minimum legal requirements for 

admissibility in a judicial proceeding to enforce the PAL permit.

( a ) Each PAL permit must contain enforceable requirements for the monitoring system that 

accurately determines plantwide 

( b ) The PAL monitoring system must employ one or more of the four general monitoring 

approaches meeting the minimum requirements set forth in paragraphs (w)(12)(ii) ( a ) 

through ( d ) of this section and must be approved by the reviewing authority.

( c ) Notwithstanding paragraph (w)(12)(i)( b ) of this section, you may also employ an 

alternative monitoring approach that meets paragraph (w)(12)(i)( a ) of this section if 

approved by the reviewing authority.

( d ) Failure to use a monitoring system that meets the requirements of this section renders 

the PAL invalid.

40 CFR 52.21(aa)(12)
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(ii) Minimum performance requirements for approved monitoring approaches. The following are 

acceptable general monitoring approaches when conducted in accordance with the minimum 

requirements in paragraphs (w)(12)(iii) through (ix) of this section:

( a ) Mass balance calculations for activities using coatings or solvents;

( b ) CEMS;

( c ) CPMS or PEMS; and

( d ) Emission factors.

(iii) Mass balance calculations. An owner or operator using mass balance calculations to monitor 

PAL pollutant emissions from activities using coating or solvents shall meet the following 

requirements:

( a ) Provide a demonstrated means of validating the published content of the PAL pollutant 

that is contained in or created by all materials used in or at the emissions unit;

( b ) Assume that the emissions unit emits all of the PAL pollutant that is contained in or 

created by any raw material or fuel used in or at the emissions unit, if it cannot otherwise be 

accounted for in the process; and

( c ) Where the vendor of a material or fuel, which is used in or at the emissions unit, 

publishes a range of pollutant content from such material, the owner or operator must use 

the highest value of the range to calculate the PAL pollutant emissions unless the reviewing 

authority determines there is site-specific data or a site-specific monitoring program to 

support another content within the range.

(iv) CEMS. An owner or operator using CEMS to monitor PAL pollutant emissions shall meet the 

following requirements:

( a ) CEMS must comply with applicable Performance Specifications found in 40 CFR part 60, 

appendix B; and

( b ) CEMS must sample, analyze, and record data at least every 15 minutes while the 

emissions unit is operating.

(v) CPMS or PEMS. An owner or operator using CPMS or PEMS to monitor PAL pollutant 

emissions shall meet the following requirements:

( a ) The CPMS or the PEMS must be based on current site-specific data demonstrating a 

correlation between the monitored parameter(s) and the PAL pollutant emissions across the 

range of operation of the emissions unit; and

( b ) Each CPMS or PEMS must sample, analyze, and record data at least every 15 minutes, 

or at another less frequent interval approved by the reviewing authority, while the emissions 

unit is operating.

(vi) Emission factors. An owner or operator using emission factors to monitor PAL pollutant 

emissions shall meet the following requirements:

( a ) All emission factors shall be adjusted, if appropriate, to account for the degree of 

uncertainty or limitations in the factors' development;

( b ) The emissions unit shall operate within the designated range of use for the emission 

factor, if applicable; and
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( c ) If technically practicable, the owner or operator of a significant emissions unit that relies 

on an emission factor to calculate PAL pollutant emissions shall conduct validation testing to 

determine a site-specific emission factor within 6 months of PAL permit issuance, unless the 

reviewing authority determines that testing is not required.

(vii) A source owner or operator must record and report maximum potential emissions without 

considering enforceable emission limitations or operational restrictions for an emissions unit 

during any period of time that there is no monitoring data, unless another method for 

determining emissions during such periods is specified in the PAL permit.

(viii) Notwithstanding the requirements in paragraphs (w)(12)(iii) through (vii) of this section, 

where an owner or operator of an emissions unit cannot demonstrate a correlation between the 

monitored parameter(s) and the PAL pollutant emissions rate at all operating points of the 

emissions unit, the reviewing authority shall, at the time of permit issuance:

( a ) Establish default value(s) for determining compliance with the PAL based on the highest 

potential emissions reasonably estimated at such operating point(s); or

( b ) Determine that operation of the emissions unit during operating conditions when there 

is no correlation between monitored parameter(s) and the PAL pollutant emissions is a 

violation of the PAL.

(ix) Re-validation. All data used to establish the PAL pollutant must be re-validated through 

performance testing or other scientifically valid means approved by the reviewing authority. 

Such testing must occur at least once every 5 years after issuance of the PAL.

(13) Recordkeeping requirements. 

(i) The PAL permit shall require an owner or operator to retain a copy of all records necessary 

to determine compliance with any requirement of paragraph (w) of this section and of the PAL, 

including a determination of each emissions unit's 12-month rolling total emissions, for 5 years 

from the date of such record.

(ii) The PAL permit shall require an owner or operator to retain a copy of the following records, 

for the duration of the PAL effective period plus 5 years:

( a ) A copy of the PAL permit application and any applications for revisions to the PAL; and

( b ) Each annual certification of compliance pursuant to title V and the data relied on in 

certifying the compliance.

(14) Reporting and notification requirements. The owner or operator shall submit semi-annual 

monitoring reports and prompt deviation reports to the reviewing authority in accordance with 

the applicable title V operating permit program. The reports shall meet the requirements in 

paragraphs (w)(14)(i) through (iii) of this section.

(i) Semi-annual report. The semi-annual report shall be submitted to the reviewing authority 

within 30 days of the end of each reporting period. This report shall contain the information 

required in paragraphs (w)(14)(i)( a ) through ( g ) of this section.

( a ) The identification of owner and operator and the permit number.

40 CFR 52.21(aa)(14)

40 CFR 52.21(aa)(13)
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( b ) Total annual emissions (tons/year) based on a 12-month rolling total for each month in 

the reporting period recorded pursuant to paragraph (w)(13)(i) of this section.

( c ) All data relied upon, including, but not limited to, any Quality Assurance or Quality 

Control data, in calculating the monthly and annual PAL pollutant emissions.

( d ) A list of any emissions units modified or added to the major stationary source during the 

preceding 6-month period.

( e ) The number, duration, and cause of any deviations or monitoring malfunctions (other 

than the time associated with zero and span calibration checks), and any corrective action 

taken.

( f ) A notification of a shutdown of any monitoring system, whether the shutdown was 

permanent or temporary, the reason for the shutdown, the anticipated date that the 

monitoring system will be fully operational or replaced with another monitoring system, and 

whether the emissions unit monitored by the monitoring system continued to operate, and 

the calculation of the emissions of the pollutant or the number determined by method 

included in the permit, as provided by paragraph (w)(12)(vii) of this section.

( g ) A signed statement by the responsible official (as defined by the applicable title V 

operating permit program) certifying the truth, accuracy, and completeness of the 

information provided in the report.

(ii) Deviation report. The major stationary source owner or operator shall promptly submit 

reports of any deviations or exceedance of the PAL requirements, including periods where no 

monitoring is available. A report submitted pursuant to §70.6(a)(3)(iii)(B) of this chapter shall 

satisfy this reporting requirement. The deviation reports shall be submitted within the time 

limits prescribed by the applicable program implementing §70.6(a)(3)(iii)(B) of this chapter. 

The reports shall contain the following information:

( a ) The identification of owner and operator and the permit number;

( b ) The PAL requirement that experienced the deviation or that was exceeded;

( c ) Emissions resulting from the deviation or the exceedance; and

( d ) A signed statement by the responsible official (as defined by the applicable title V 

operating permit program) certifying the truth, accuracy, and completeness of the 

information provided in the report.

(iii) Re-validation results. The owner or operator shall submit to the reviewing authority the 

results of any re-validation test or method within three months after completion of such test or 

method.

(15) Transition requirements. 

(i) No reviewing authority may issue a PAL that does not comply with the requirements in 

paragraphs (w)(1) through (15) of this section after the Administrator has approved regulations 

incorporating these requirements into a plan.

(ii) The reviewing authority may supersede any PAL which was established prior to the date of 

approval of the plan by the Administrator with a PAL that complies with the requirements of 

paragraphs (w)(1) through (15) of this section.

40 CFR 52.21(aa)(15)
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(x) (x) If any provision of this section, or the application of such provision to any person or 

circumstance, is held invalid, the remainder of this section, or the application of such provision to 

persons or circumstances other than those as to which it is held invalid, shall not be affected 

thereby.

40 CFR 52.21(bb)

(y) (y) Equipment replacement provision. Without regard to other considerations, routine 

maintenance, repair and replacement includes, but is not limited to, the replacement of any 

component of a process unit with an identical or functionally equivalent component(s), and 

maintenance and repair activities that are part of the replacement activity, provided that all of 

the requirements in paragraphs (y)(1) through (3) of this section are met.

(1) Capital Cost threshold for Equipment Replacement. 

(i) For an electric utility steam generating unit, as defined in §51.166(b)(30), the fixed capital 

cost of the replacement component(s) plus the cost of any associated maintenance and repair 

activities that are part of the replacement shall not exceed 20 percent of the replacement value 

of the process unit, at the time the equipment is replaced. For a process unit that is not an 

electric utility steam generating unit the fixed capital cost of the replacement component(s) 

plus the cost of any associated maintenance and repair activities that are part of the 

replacement shall not exceed 20 percent of the replacement value of the process unit, at the 

time the equipment is replaced.

(ii) In determining the replacement value of the process unit; and, except as otherwise allowed 

under paragraph (y)(1)(iii) of this section, the owner or operator shall determine the 

replacement value of the process unit on an estimate of the fixed capital cost of constructing a 

new process unit, or on the current appraised value of the process unit.

(iii) As an alternative to paragraph (y)(1)(ii) of this section for determining the replacement 

value of a process unit, an owner or operator may choose to use insurance value (where the 

insurance value covers only complete replacement), investment value adjusted for inflation, or 

another accounting procedure if such procedure is based on Generally Accepted Accounting 

Principles, provided that the owner or operator sends a notice to the reviewing authority. The 

first time that an owner or operator submits such a notice for a particular process unit, the 

notice may be submitted at any time, but any subsequent notice for that process unit may be 

submitted only at the beginning of the process unit's fiscal year. Unless the owner or operator 

submits a notice to the reviewing authority, then paragraph (y)(1)(ii) of this section will be 

used to establish the replacement value of the process unit. Once the owner or operator 

submits a notice to use an alternative accounting procedure, the owner or operator must 

continue to use that procedure for the entire fiscal year for that process unit. In subsequent 

fiscal years, the owner or operator must continue to use this selected procedure unless and 

until the owner or operator sends another notice to the reviewing authority selecting another (2) Basic design parameters. The replacement does not change the basic design parameter(s) of 

the process unit to which the activity pertains.

(i) Except as provided in paragraph (y)(2)(iii) of this section, for a process unit at a steam 

electric generating facility, the owner or operator may select as its basic design parameters 

either maximum hourly heat input and maximum hourly fuel consumption rate or maximum 

hourly electric output rate and maximum steam flow rate. When establishing fuel consumption 

specifications in terms of weight or volume, the minimum fuel quality based on British Thermal 

Units content shall be used for determining the basic design parameter(s) for a coal-fired 

electric utility steam generating unit.

These provisions were 

stayed indefinitely by a 

court order on December 

24, 2003. Rules 904, 

518, and 3.24 exclude 

these provisions as they 

appear in 40 CFR 

52.21(cc). 
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(ii) Except as provided in paragraph (y)(2)(iii) of this section, the basic design parameter(s) for 

any process unit that is not at a steam electric generating facility are maximum rate of fuel or 

heat input, maximum rate of material input, or maximum rate of product output. Combustion 

process units will typically use maximum rate of fuel input. For sources having multiple end 

products and raw materials, the owner or operator should consider the primary product or 

primary raw material when selecting a basic design parameter.

(iii) If the owner or operator believes the basic design parameter(s) in paragraphs (y)(2)(i) and 

(ii) of this section is not appropriate for a specific industry or type of process unit, the owner or 

operator may propose to the reviewing authority an alternative basic design parameter(s) for 

the source's process unit(s). If the reviewing authority approves of the use of an alternative 

basic design parameter(s), the reviewing authority shall issue a permit that is legally 

enforceable that records such basic design parameter(s) and requires the owner or operator to 

comply with such parameter(s).

(iv) The owner or operator shall use credible information, such as results of historic maximum 

capability tests, design information from the manufacturer, or engineering calculations, in 

establishing the magnitude of the basic design parameter(s) specified in paragraphs (y)(2)(i) 

and (ii) of this section.

(v) If design information is not available for a process unit, then the owner or operator shall 

determine the process unit's basic design parameter(s) using the maximum value achieved by 

the process unit in the five-year period immediately preceding the planned activity.

(vi) Efficiency of a process unit is not a basic design parameter.

(3) The replacement activity shall not cause the process unit to exceed any emission limitation, 

or operational limitation that has the effect of constraining emissions, that applies to the process 

unit and that is legally enforceable.

Note to paragraph (y): By a court order on December 24, 2003, this paragraph (y) is stayed 

indefinitely. The stayed provisions will become effective immediately if the court terminates the 

stay. At that time, EPA will publish a document in the Federal Register advising the public of 

the termination of the stay.

(Secs. 101(b)(1), 110, 160–169, 171–178, and 301(a), Clean Air Act, as amended (42 U.S.C. 

7401(b)(1), 7410, 7470–7479, 7501–7508, and 7601(a)); sec. 129(a), Clean Air Act 

Amendments of 1977 (Pub. L. 95–95, 91 Stat. 685 (Aug. 7, 1977)))

[43 FR 26382, June 19, 1978]

Editorial Note: For Federal Register citations affecting §51.166, see the List of CFR Sections 

Affected, which appears in the Finding Aids section of the printed volume and at www.fdsys.gov .

Effective Date Note: At 76 FR 17553, Mar. 30, 2011, §51.166 paragraphs (b)(2)(v) and 

(b)(3)(iii) (d) are stayed indefinitely.

Sections in 40 CFR 52.21 that are not otherwise required, or may be required, for a PSD 

program in 40 CFR 51.166 and that were not excluded by Distric Rule 2410
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40 CFR 

52.21(b)(54)

RACT (54) Reasonably available control technology (RACT) is as defined in §51.100(o) of this chapter. Definition not in 51.166, 

but does not effect the 

other definitions or 

requirements for a PSD 

program