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Express Terms 

Part 231, NEW SOURCE REVIEW [IN NONATTAINMENT AREAS AND OZONE TRANSPORT 

REGIONS] FOR NEW AND MODIFIED FACILITIES

Subpart 231-1 Requirements for Emission Sources Subject to the Regulation Prior to November 15, 1992 

Subpart 231-2 Requirements for Emission Units Subject to the Regulation on or after November 15, 1992 and Prior 

to the Effective Date of Subparts 231-3 through 231-13

Existing Subpart 231-1 remains unchanged. 

Existing Subpart 231-2 through Subdivision 231-2.2(a) remains unchanged. 

Existing Paragraph 231-2.2(a)(1) is amended as follows: 

(1) a permit action for such emission unit occurs on or after November 15, 1992; or an exempt or trivial 

activity is constructed on or after November 15, 1992 and prior to the effective date of Subparts 231-3 

through 231-13; and 

Existing Paragraph 231-2.2(a)(2) through Section 231-2.13 remains unchanged. 

New Subparts 231-3 through 231-13 are adopted to read as follows: 

Subpart 231-3 General Provisions 

Subpart 231-4 Definitions 

Subpart 231-5 New Major Facilities and Modifications to Existing Non-major Facilities in Nonattainment 

Areas and Attainment Areas of the State within the Ozone Transport Region 

Subpart 231-6 Modifications to Existing Major Facilities in Nonattainment Areas and Attainment Areas of 

the State within the Ozone Transport Region 

Subpart 231-7 New Major Facilities and Modifications to Existing Non-major Facilities in Attainment 
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Areas (Prevention of Significant Deterioration) 

Subpart 231-8 Modifications to Existing Major Facilities in Attainment Areas (Prevention of Significant 

Deterioration) 

Subpart 231-9 Plantwide Applicability Limitation (PAL) 

Subpart 231-10 Emission Reduction Credits (ERCs) 

Subpart 231-11 Permit and Reasonable Possibility Requirements 

Subpart 231-12 Ambient Air Quality Impact Analysis 

Subpart 231-13 Tables and Emission Thresholds 

Subpart 231-3 General Provisions 

Section 

231-3.1 Statement of purpose 

231-3.2 Transition plan 

231-3.3 Summary of applicability 

231-3.4 Exemptions 

231-3.5 General prohibitions 

231-3.6 Source obligation 

231-3.7 Permits 

231-3.8 Requirement to commence construction 

231-3.9 Facility shakedown period 

231-3.10 Circumvention 

231-3.11 Severability clause 

231-3.1 Statement of purpose. The purpose of this Part is to establish the new source review (NSR) preconstruction, 
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construction and operation requirements for new and modified facilities in a manner which furthers the policy and 

objectives of Article 19 of the Environmental Conservation Law, and meets the Plan Requirements for 

Nonattainment Areas (Part D) and Prevention of Significant Deterioration (PSD) of Air Quality (Part C) of 

subchapter I of the Act. 

231-3.2 Transition plan. 

(a) On or after the effective date of this Subpart, any owner and/or operator of a proposed new or modified 

facility, for which a complete application has not been submitted to the department, must comply with the 

provisions of Subparts 231-3 through 231-13 of this Part. 

(b) On or after the effective date of this Subpart, Subpart 231-2 will only apply to applications determined to 

be complete prior to the effective date of this Subpart. 

231-3.3 Summary of applicability. 

(a) Subpart 231-5 of this Part applies to proposed new facilities, and to modifications at existing non-major 

facilities, proposed in a designated nonattainment area or in the ozone transport region which by themselves equal 

or exceed the applicable major facility threshold. 

(b) Subpart 231-6 of this Part applies to modifications of existing major facilities proposed in a designated 

nonattainment area or in the ozone transport region. 

(c) Subpart 231-7 of this Part applies to proposed new facilities, and to modifications at existing non-major 

facilities, proposed in areas designated in attainment of the national ambient air quality standards (NAAQS) or 

unclassified which by themselves equal or exceed the applicable major facility threshold. 
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(d) Subpart 231-8 of this Part applies to modifications of existing major facilities proposed in areas 

designated in attainment of the NAAQS or unclassified. 

(e) Subpart 231-9 of this Part provides for a voluntary management of activities at an existing major facility 

under a Plantwide Applicability Limitation (PAL). 

(f) Subpart 231-10 of this Part specifies how to create and use ERCs. 

 (g) Subpart 231-11 of this Part specifies permit and reasonable possibility requirements. 

(h) Subpart 231-12 of this Part defines the requirements for an ambient air quality impact analysis. 

(i) Subpart 231-13 of this Part sets forth tables and emission thresholds for determining applicability. 

231-3.4 Exemptions. 

(a) Any applicant for a proposed new or modified facility which is subject to this Part may petition the 

department and the administrator of the United States Environmental Protection Agency, in accordance with 42 

U.S.C. section 7511a(f), for a determination that net air quality benefits are greater in the absence of reductions of 

oxides of nitrogen from the facility. In addition, this Part shall not apply to facilities in nonattainment areas within 

the ozone transport region if the administrator determines, in accordance with section 7511a(f), that reductions of 

NOx would not produce net ozone air quality benefits, or facilities in nonattainment areas outside the ozone 

transport region if the administrator determines, in accordance with section 7511a(f), that reductions of NOx would 

not contribute to attainment of the national ambient air quality standard for ozone in the area. To the extent that 

such a petition is granted by both the department and the administrator, consistent with the Act, the requirements of 
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this Part for the proposed new or modified facility with respect to emissions of NOx shall not apply. 

(b) The facility is exempt from this Part if it is major based only on the addition of fugitive emissions and 

does not belong to one of the source categories listed in Table 9 of Subpart 231-13 of this Part. 

(c) The provisions of Subparts 231-7 and 231-8 of this Part do not apply to a new or modified facility as 

follows: 

(1) The facility or emission source is portable and has previously received a permit under 

requirements equivalent to those contained in this Part, if: 

(i) the facility or emission source proposes to relocate and emissions of the facility or 

emission source at the new location would be for less than one year; and 

(ii) the emissions from the facility would not exceed its emission limit(s) established in a 

permit; and 

(iii) the emissions from the facility would impact no Federal Class I area and no area where 

an applicable increment is known to be violated; and 

(iv) reasonable notice is given to the department prior to the relocation identifying the 

proposed new location and the probable duration of operation at the new location. Such notice must 

be given to the department not less than 10 days in advance of the proposed relocation unless a 

different time duration is previously approved by the department; or 
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(2) With respect to a particular regulated NSR contaminant, the facility is located in an area 

designated as nonattainment under section 107 of the Act for that contaminant. 

(d) For the purposes of Subparts 231-7 and 231-8 of this Part, if the emissions from a facility or modification 

would occur for less than one year and impact no Federal Class I area, no area where an applicable increment is 

known to be violated, and would not contribute to known standards violations, then the requirements of Subparts 

231-7 and 231-8 of this Part regarding Source Impact Analysis and Additional Impact Analyses, and Section 231-

12.3 (Pre-application analysis for Subparts 231-7 and 231-8) of this Part, do not apply to a facility with respect to a 

particular regulated NSR contaminant. 

(e) If an existing major facility owner or operator submits a Part 201 application that includes a proposed 

modification and a request for enforceable permit terms and conditions to restrict or cap facility wide emissions, in 

accordance with Subpart 201-7 of this Title, below applicable major facility thresholds, the modification is not 

subject to the requirements of this Part. The Part 201 state facility permit issued by the department must include all 

applicable requirements, including any control technology requirements and emission limitations that were in the 

Title V permit. 

(f) Any emission source which is to be operated for less than one year, is determined not to be a significant 

action in accordance with the procedures contained in Part 617 of this Title, and which has a project emission 

potential less than the applicable significant project threshold in Table 3, Table 4 or Table 6 of Section 231-13 of 

this Part, is not subject to this Part. 

231-3.5 General prohibitions. Construction and operation prohibited. No owner or operator of a proposed major 

facility, NSR major modification, or existing major facility which undertakes a significant modification but avoids 

NSR applicability through netting, shall be allowed to begin actual construction, commence operation, or operate 
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such new facility or modification, as appropriate, without a permit which incorporates the requirements of this Part. 

 This provision shall not affect any requirement under Part 201 of this Title for an owner and/or operator to obtain a 

permit or permit modification prior to beginning actual construction, commencing operation or operating a new or 

modified facility. 

231-3.6 Source obligation. 

(a) The issuance of a permit does not relieve any owner or operator of the responsibility to comply fully with 

applicable provisions of the State Implementation Plan and any other requirements under local, State, or Federal 

law. 

(b) For the purposes of Subparts 231-7 and 231-8 of this Part only, at such time that a particular facility 

becomes a major facility, or a modification becomes a NSR major modification solely by virtue of a relaxation in 

any enforceable limitation which was established after August 7, 1980, on the capacity of the facility or 

modification otherwise to emit a regulated NSR contaminant, such as a restriction on hours of operation, then the 

requirements of Subparts 231-7 and 231-8 of this Part, as applicable, apply to the facility as though construction had 

not yet commenced on the facility. 

 (c) Any owner or operator of a facility that proposes a project that involves a physical change or change in 

the method of operation that the owner or operator determines would be followed by a facility emissions increase 

that equals or exceeds any of the significant project thresholds in Subpart 231-13 of this Part, Tables 3, 4 or 6, must 

notify the department in writing of the proposed project prior to implementing the change if the owner or operator 

determines that the project does not constitute a modification because all the emission increases are attributable to 

independent factors in accordance with Clause 231-4.1(b)(40)(i)(c) of this Part. The notification shall include the 

following: 
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 (1) A description of the change. 

 (2) The calculation of the projected emissions increase. 

 (3) The proposed date of the change. 

 (4) An explanation of the factual basis for the conclusion that none of the projected emission 

 increases are attributable to the proposed project. 

231-3.7 Permits. 

(a) Permit applications for proposed new and modified facilities subject to this Part will be processed in 

accordance with Parts 201 and 621 of this Title. 

(b) In accordance with section 165(c) of the Act, the department will make a final determination on an 

application submitted pursuant to Subpart 231-7 or Subpart 231-8 of this Part within one year of the filing of a 

complete application as defined under Part 621 of this Title. 

231-3.8 Requirement to commence construction. 

 The existence of a valid permit shall not be construed as authorizing construction if construction is not 

commenced within 18 months after the date of permit issuance, if construction is discontinued for a period of 18 

months or more, or if construction is not completed within a reasonable time as determined by the department. The 

department may grant one extension for a period not to exceed 18 months upon a satisfactory showing that an 

extension is justified. A permit shall become subject to revocation or modification if construction is not commenced 

and completed as provided in this section. This provision does not apply to the time period between the completion 

and start of construction, of the approved phases, of a phased construction project; each phase must commence 
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construction within 18 months of its projected and approved commencement date. 

231-3.9 Facility shakedown period. 

 Upon commencement of operation, as defined in subparagraph 231-4.1(b)(11)(i), of a major facility or new 

or modified emission source(s) at an existing facility, the owner or operator is allowed a shakedown period for such 

major facility or modified emission source(s) according to the following provisions: 

 

 (a) The shakedown period shall not exceed 180 days from the date of commencement of operation. The 

department may specify a shakedown period of less than 180 days in a permit. 

 (b) The total mass emissions during the shakedown period must be quantified, in a manner approved by the 

department, and are to be included in the calculation demonstrating compliance with the permitted annual limit in 

tons per year (tpy) of the facility or emission source(s). 

 (c) Emission limits other than annual emission limitations do not apply to a major facility or new or modified 

emission source(s) at an existing facility during the shakedown period. However, the owner or operator must make 

all reasonable efforts to minimize emissions during the shakedown period. 

231-3.10 Circumvention. 

(a) An owner or operator of a facility may not circumvent this Part by causing or allowing a pattern of 

ownership or development, including the phasing, staging, delaying, or engaging in incremental construction at a 

facility which, except for the pattern of ownership or development, would otherwise require a permit. 

(b) The sale or other transfer of a facility to a new owner or operator does not relieve the new owner or 

operator from the requirement to obtain a permit and operate the facility in conformance with the requirements of 
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this Part. 

231-3.11 Severability clause. 

 Each section or portion thereof, of this Part shall be deemed severable, and in the event that any section, or 

portion thereof, of this Part is held to be invalid, the remainder of this Part will continue in full force and effect. 

Subpart 231-4 Definitions 

231-4.1 Definitions. 

(a) Unless otherwise defined in this section, the general definitions of Parts 200 and 201 of this Title apply. 

(b) For the purposes of this Part the following definitions also apply: 

(1) Actual emissions. For the purposes of determining the baseline concentration, and the 

calculation of air quality impacts according to Section 231-12.2 of this Part: 

(i) The actual rate of emissions of a regulated NSR contaminant from an emission source, as 

determined in accordance with the following paragraphs. 

(ii) Actual emissions as of a particular date shall equal the rate at which the emission source 

actually emitted the regulated NSR contaminant during the 24 consecutive month period which 

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

department will allow the use of a different time period upon a determination that it is more 

representative of normal facility operation. Actual emissions shall be calculated using the emission 

source’s actual operating hours, production rates, and types of materials processed, stored, or 

combusted during the selected time period. 
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(iii) The department may presume that facility-specific allowable emissions for the emission 

source are equivalent to the actual emissions of the emission source. 

(iv) For any emission source that has not commenced operation on the particular date, actual 

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

(2) Adverse impact on visibility. Visibility impairment which interferes with the management, 

protection, preservation or enjoyment of the visitor's visual experience of the Federal Class I area. This 

determination must be made on a case-by-case basis taking into account the geographic extent, intensity, 

duration, frequency and time of visibility impairment. 

(3) Allowable emissions. This definition applies only for the purposes of determining the baseline 

concentration and the calculation of air quality impacts according to Section 231-12.2 of this Part. The 

emission rate of a facility calculated using the maximum rated capacity of the facility (unless the facility is 

subject to permit conditions which restrict the operating rate, or hours of operation, or both) and the most 

stringent of the following: 

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

(ii) The applicable state implementation plan emissions limitation, including those with a 

future compliance date; or 

(iii) The emission rate specified in a permit condition, including those with a future 
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compliance date. 

(4) Baseline actual emissions. The annual rate of emissions of a regulated NSR contaminant from an 

emission source determined as follows: 

(i) The average rate (as defined in Clauses a, b, c, and, d below), in tpy, at which an emission 

source physically emitted the contaminant during its baseline period, determined by using the 

source=s actual operating hours, production rates, and types of materials processed, stored, or 

combusted during the selected baseline period. 

(‘a’) The average rate includes fugitive emissions to the extent quantifiable if the 

facility belongs to one of the source categories listed in Table 9 of Subpart 231-13 of this 

Part, and emissions associated with startups, shutdowns, and malfunctions. 

(‘b’) The average rate must be adjusted downward to exclude any non-compliant 

emissions that occurred while the emission source was operating above any applicable 

emission limitation. 

(‘c’) Except for electric utility steam generating units, the average rate must be 

adjusted downward to exclude any emissions that exceeded an emission limitation with 

which the emission source must currently comply, had such emission source been required to 

comply with such limitations during the baseline period. However, if an emission limitation 

is part of a maximum achievable control technology standard that the administrator proposed 

or promulgated under 40 CFR Part 63, the baseline actual emissions rate 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 40 CFR 
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51.165(a)(3)(ii)(G). For the purposes of a creditable emission increase or emission reduction 

credit used for netting, currently means at the time that the increase or reduction actually 

occurred. 

(‘d’) For a regulated NSR contaminant, when a project involves multiple emissions 

sources, one baseline period must be used to determine the baseline actual emissions of the 

emission sources being modified. A different baseline period cannot be used for each 

regulated NSR contaminant. 

(ii) The applicant must use a reliable basis for quantifying the baseline actual emissions. 

Continuous emissions monitoring (CEM) data or stack test data approved by the department must be 

used if the facility is required to generate such data. If such data is not available, acceptable bases 

for quantifying baseline actual emissions include, but are not limited to, emission statements, EPA's 

AP-42 emission factors, and fuel and solvent purchase records, with department approval. 

(5) Baseline area. Any intrastate area (and every part thereof), designated as attainment or 

unclassifiable under section 107 of the Act, in which the major facility or NSR major modification 

establishing the minor facility baseline date would construct or would have an air quality impact equal to or 

greater than 1 μg/m3 (annual average) of the regulated NSR contaminant for which the minor facility 

baseline date is established. 

(i) Area redesignations under section 107 of the act cannot intersect or be smaller than the 

area of impact of any major facility or NSR major modification which establishes a minor facility 

baseline date; or 
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(ii) Baseline areas pursuant to established Air Quality Control Regions (AQCR) are defined 

and listed in the department’s policy document on ambient air quality impact analysis procedures. 

(6) Baseline concentration. 

(i) The ambient concentration level that exists in the baseline area at the time of the 

applicable minor facility baseline date. A baseline concentration is determined for each regulated 

NSR contaminant for which a minor facility baseline date is established and must include: 

(‘a’) the actual emissions representative of facilities in existence on the applicable 

minor facility baseline date, except as provided in this Subparagraph; and 

(‘b’) the allowable emissions of major facilities that commenced construction before 

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

baseline date. 

 

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

applicable maximum allowable increase(s): 

(‘a’) Actual emissions from any major facility on which construction commenced 

after the major facility baseline date; and 

(‘b’) Actual emission increases and decreases at any facility occurring after the minor 

facility baseline date. 
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(7) Baseline period. A period of time used to quantify a creditable emission increase, an ERC, or 

project emission potential. The baseline period consists of any 24 consecutive months within the five years 

immediately preceding the date identified below (if less than 24 consecutive months of operation exist, this 

period of operation must be used as the baseline period): 

(i) For a creditable emission increase which has physically occurred, the date of the 

occurrence of the emission increase; 

(ii) For an ERC which has physically occurred, the date of the occurrence of the emission 

reduction; 

(iii) For a creditable emission increase or an ERC which is scheduled to occur in the future, 

the date of receipt by the department of the permit application which proposes to use the creditable 

emission increase or ERC; 

(iv) For the calculation of project emission potential of a modification, the date of receipt by 

the department of a permit application for the modification; or 

(v) For a facility which fails to submit a permit application for a NSR major modification and 

begins actual construction of such modification, the department will determine an appropriate 

baseline period. 

(8) Begin actual construction. In general, initiation of physical on-site construction activities on an 
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emission source which are of a permanent nature. Such activities include, but are not limited to, installation 

of building supports and foundations, laying underground pipe work and construction of permanent storage 

structures. With respect to a change in method of operations, this term refers to those on-site activities other 

than preparatory activities which mark the initiation of the change. 

 

 (9) Best available control technology (BACT). An emissions limitation based on the maximum 

degree of reduction for each air pollutant subject to regulation under the Act which would be emitted from 

or which results from any proposed major facility or NSR major modification which the department, on a 

case-by-case basis, taking into account energy, environmental, and economic impacts and other costs, 

determines is achievable for such proposed major facility or NSR major modification through application of 

production processes or available methods, systems, and techniques, including fuel cleaning, clean fuels, or 

treatment or innovative fuel combustion techniques for control of such air pollutant. In no event shall 

application of BACT result in emissions of any air pollutant which would exceed the emissions allowed by 

any applicable standard established pursuant to section 7411 or 7412 of the Act. Emissions from any source 

utilizing clean fuels, or any other means, to comply with this paragraph shall not be allowed to increase 

above levels that would have been required under this paragraph as it existed prior to enactment of the Clean 

Air Act Amendments of 1990. 

(10) Commence construction. The date on which the owner or operator has all necessary 

preconstruction approvals or permits (including those permits or approvals required under federal air quality 

control laws and those which are part of the state implementation plan) and has either: 

(i) begun, or caused to begin, a continuous program of actual construction, to be completed 

within a reasonable time as determined by the department; or 
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(ii) entered into binding agreements or contractual obligations, which cannot be canceled or 

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

construction to be completed within a reasonable time as determined by the department. 

With respect to a change in the method of operation, commence construction refers to those on-site 

activities other than preparatory activities which mark the initiation of the change. 

(11) Commence(s) operation or commencement of operation. 

 (i) the date that a proposed new or modified facility first emits or increases emissions of any 

regulated NSR contaminant to which this Part applies; or 

(ii) the date on which the facility shakedown period ends for a proposed modified facility 

which utilizes future ERCs for netting. 

(12) Contemporaneous. The time period used in a net emission increase determination for a 

regulated NSR contaminant as follows: 

(i) The period beginning five years prior to the proposed commence construction date of the 

new or modified emission source, and ending with the proposed commence operation date. These 

dates must be proposed by an applicant in a permit application. 

(ii) For facilities proposing to use an alternative operating scenario pursuant to Part 201 of 

this Title, the period beginning five years prior to the date the application for the permit modification 
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is determined complete by the department, in accordance with Part 621 of this Title, and ending with 

the final permit issuance date. 

(13) Creditable emission increase. Any increase in emissions of a regulated NSR contaminant in tpy 

from an emission source at an existing major facility, other than such an increase from any proposed 

modified facility under review, which: 

(i) results from a physical change in, or a change in the method of operation of an emission 

source(s); and 

(ii) is quantified as the difference between baseline actual emissions and projected actual 

emissions. 

(14) Curtailment. A restriction on the operation of an emission source at an existing facility included 

in a permit, which results in an emission reduction and reflects a partial reduction in hours of operation or 

capacity utilization of such emission source. 

(15) Electric utility steam generating unit. Any steam-electric generating unit constructed for the 

purpose of supplying more than one-third of its potential electric output capacity and more than 25 

megawatts of 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 steam-electric generator that would 

produce electrical energy for sale is also considered in determining the electrical energy output capacity. 

(16) Emission offset. ERCs or emission reductions which are required to be obtained by a proposed 

new or modified facility, which is or will be located in a nonattainment area or an attainment area of the 
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state within the ozone transport region, in order to obtain a permit to construct and/or operate a new or 

modified facility. 

(17) Emission reduction credit, ERC. The actual decrease in emissions of a regulated NSR 

contaminant, in tpy, determined in accordance with the requirements of Subpart 231-10 of this Part. 

(18) Emission source shutdown. For the purposes of establishing ERCs: 

 (i) the permanent removal from service of an emission source, as reflected by a permit 

 condition that formally prohibits the emission source from further operation, provided that it does not 

 result in a facility shutdown; or 

 (ii) the physical removal of an emission source at a facility as reflected by a permit 

 modification that removes the emission source from the permit, provided that it does not result in a 

 facility shutdown. 

(19) Facility shutdown. For the purposes of establishing ERCs, the permanent removal from service 

of all emission sources at a facility, as reflected by the surrender to the department of the applicable Title V 

or state facility permit, or registration. 

(20) Federal Class I area. All of the following areas which were in existence on August 7, 1977 shall 

be Federal Class I areas and may not be redesignated: 

(i) International parks; 
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(ii) National wilderness areas which exceed 5,000 acres in size; 

(iii) National memorial parks which exceed 5000 acres in size; 

(iv) National parks which exceed 6000 acres in size. 

(21) Federal Land Manager. With respect to any Class I lands of the United States, the Secretary of 

the department with authority over such Class I lands. 

(22) Future reductions. Reductions which are scheduled to occur subsequent to the issuance of a 

permit for a new or modified major facility using the reductions. 

(23) Internal offset. ERCs of volatile organic compounds (VOC) or NOx, in the severe ozone 

nonattainment area only, from emission sources within the same existing major facility as a proposed NSR 

major modification, which physically occur on or after November 15, 1990. Such reductions must meet the 

requirements of this Part. 

(24) Major facility baseline date. 

(i) In the case of particulate matter (PM) and SO2, January 6, 1975, and 

(ii) In the case of nitrogen dioxide, February 8, 1988. 
Page 21 of 124 

(25) Major PAL emission source. For the purposes of Subpart 231-9 of this Part, any emission 

source located in an attainment area that emits or has the potential to emit 100 tpy or more of a PAL 

contaminant; or any emission source located in a nonattainment area that emits or has the potential to emit a 

PAL contaminant in an amount that is equal to or greater than the major facility threshold for the PAL 

contaminant. 

(26) Minor PAL emission source. For the purposes of Subpart 231-9 of this Part, an emission source 

that emits or has the potential to emit a PAL contaminant in an amount less than the significant project 

threshold as listed in Subpart 231-13 of this Part or in the Act, whichever is lower, for that PAL 

contaminant. 

(27) Minor facility baseline date. The earliest date after the trigger date on which a major facility or 

a NSR major modification subject to Subpart 231-7 or 231-8 of this Part submits a complete application. 

(i) The trigger date is: 

(‘a’) in the case of PM and SO2, August 7, 1977; and 

(‘b’) in the case of nitrogen dioxide, February 8, 1988. 

(ii) The baseline date is established for each contaminant for which increments or other 

equivalent measures have been established if: 

(‘a’) the area in which the proposed emission source or modification would construct 

is designated as attainment or unclassifiable under section 7407 of the Act for the regulated 
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NSR contaminant on the date of its complete application; and 

(‘b’) in the case of a major facility, the regulated NSR contaminant would be emitted 

at or greater than the major facility thresholds, or, in the case of a NSR major modification, 

there would be a significant net emissions increase of the regulated NSR contaminant. 

(iii) The minor facility baseline dates have been established for SO2, NOx, and PM-10. 

These dates are listed in the department=s policy documents on air quality impact analysis. 

(28) Modification. Any physical change in, or change in the method of operation of, a facility which 

results in a level of annual emissions in excess of the baseline actual emissions of any regulated NSR 

contaminant emitted by such facility or which results in the emission of any regulated NSR contaminant not 

previously emitted. A modification shall not include the following: 

 (i) routine maintenance, repair, or replacement as defined in Part 200 of this Title; 

(ii) use of an alternative fuel or raw material by reason of an order under sections 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; 

(iii) use of an alternative fuel by reason of an order or rule under section 125 of the Act; 

(iv) use of an alternative fuel at a steam generating unit to the extent that the fuel is generated 

from municipal solid waste; 
Page 23 of 124 

(v) use of an alternative fuel or raw material by a facility which: 

 (‘a’) the facility 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 Part 51 Subpart I or 40 CFR 51.166; or 

 (‘b’) the facility is approved to use, pursuant to this Part, or which is included in a 

permit issued pursuant to 40 CFR 52.21. 

(vi) an increase in the hours of operation or in the production rate, unless such change would 

be prohibited under any permit condition which was established after January 6, 1975, pursuant to 

40 CFR 52.21 or under regulations approved pursuant to 40 CFR Part 51 Subpart I or 40 CFR 

51.166; 

(vii) any change in ownership at a facility. 

(29) Net emission increase. The aggregate increase in emissions of a regulated NSR contaminant in 

tpy at an existing major facility resulting from the sum of: 

 (i) the project emission potential of the modification; and 

 (ii) every creditable emission increase at the facility which is contemporaneous and for which 

an emission offset was not obtained; and 
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 (iii) any ERC at the facility, or portion thereof, selected by the applicant which is 

contemporaneous and which was not previously used as part of an emission offset or an internal 

offset. 

(30) Nonattainment contaminant. A regulated NSR contaminant emitted by an emission source 

located or proposed to be located in an area designated in Part 200 of this Title as nonattainment for that 

contaminant. All of New York State is within the ozone transport region as designated by the act. 

Therefore, VOC and NOx are treated as nonattainment contaminants statewide as precursors of ozone. 

(31) NSR major modification. Any modification of a major facility that would exceed the applicable 

significant project threshold of a regulated NSR contaminant in Table 3, Table 4, or Table 6 of Subpart 231-

13 of this Part; and would result in a significant net emissions increase of that contaminant from the major 

facility. 

(i) Any modification with a project emission potential for VOC or NOx that exceeds the 

applicable significant project threshold or any net emissions increase at a major facility that is 

significant for VOC or NOx shall be considered significant for ozone. 

(ii) This definition shall not apply with respect to a particular regulated NSR contaminant 

when the major facility is complying with the requirements under Subpart 231-9 of this Part for a 

PAL for that contaminant. Instead, the definition of PAL major modification shall apply. 

(32) Offset ratio. The ratio of a required ERC, on a nonattainment contaminant specific basis, to the 

project emission potential of a modification at an existing facility or the potential to emit of a new facility, 
Page 25 of 124 

as applicable. Offset ratios are listed in Subpart 231-13 of this Part. 

(33) Permanent. Permanent relative to an ERC from an emission source means that the reduction is 

irreversible through the life of the emission source except as provided in this Part. 

(34) Plantwide applicability limitation (PAL). A facility-wide emission limitation for a regulated 

NSR contaminant at a major facility that is expressed in tpy and is included in the facility=s permit. 

(35) PAL contaminant. The regulated NSR contaminant for which a PAL is established at a major 

facility. 

(36) PAL effective date. The date of issuance of the permit which establishes a PAL. The PAL 

effective date for a facility that undergoes a modification which increases a prior PAL is the date when the 

modification commences operation and begins to emit the PAL contaminant. 

(37) PAL effective period. The period beginning with the PAL effective date and ending 10 years 

later or, the date of expiration of the Title V permit following the renewal of the Title V permit which 

established the PAL, whichever is earlier. Thereafter, the effective period is 10 years from date of issuance 

of the Title V permit. The effective period is not to exceed 10 years. 

 (38) PAL major modification. Notwithstanding the definitions for NSR major modification and net 

emissions increase, any modification of a facility with a PAL that causes it to emit the PAL contaminant at a 

level equal to or greater than the PAL. 

(39) Project emission potential. Project emission potential is determined only for modifications at 
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existing facilities. 

(i) For each regulated NSR contaminant, the project emission potential must consider only 

the proposed emission increases and is calculated as the sum of the following: 

(‘a’) For new emission sources, the potential to emit of each emission source; and 

(‘b’) For existing emission sources at a non-major facility, the difference between the 

baseline actual emissions and the potential to emit of the emission source; or 

(‘c’) For existing emission sources at a major facility, the difference between the 

baseline actual emissions and the projected actual emissions of the emission source. 

(ii) Project emission potential does not include secondary emissions. 

(iii) Fugitive emissions are not included in the project emission potential unless the facility 

belongs to one of the source categories listed in Table 9 of Subpart 231-13 of this Part. 

(iv) For emergency power generating stationary internal combustion engines, the project 

emission potential will be based on a maximum of 500 hours of operation per year per engine unless 

a more restrictive limitation exists in a permit or registration. 

(40) Projected actual emissions. The maximum annual rate, in tpy, at which an existing emission 

source is projected to emit a regulated NSR contaminant in any one of the five years (12-month period) 

following the date the source commences operation after a modification, or in any one of the 10 years 
Page 27 of 124 

following that date if the project involves increasing the emission source=s design capacity or its potential to 

emit that regulated NSR contaminant and full utilization of the emission source would result in exceeding 

the applicable significant project threshold in Tables 3, 4 or 6 of Subpart 231-13 of this Part or a significant 

net emissions increase at the major facility. Projected actual emissions are calculated only for existing 

major facilities. 

(i) In determining the projected actual emissions as defined in this Section (before beginning 

actual construction), the owner or operator of the major facility: 

(‘a’) must consider all relevant information, including but not limited to, historical 

operational data, the facility=s own representations, the facility=s expected business activity 

and the facility=s highest projections of business activity, the facility=s filings with the State 

or federal regulatory authorities, and compliance plans under the approved State 

Implementation Plan; and 

(‘b’) must include fugitive emissions to the extent quantifiable if the facility belongs 

to one of the source categories listed in Table 9 of Subpart 231-13 of this Part , and 

emissions associated with startups and shutdowns; and 

(‘c’) may exclude, in calculating any increase in emissions that results from the 

particular project, that portion of the emission source=s emissions following the project that 

the existing emission source could have accommodated during the consecutive 24-month 

period used to establish the baseline actual emissions and that are also unrelated to the 

particular project. 
Page 28 of 124 

(ii) In lieu of using the method set out in Subparagraph (i) of this Paragraph, the owner or 

operator of the facility may elect to use the potential to emit of the emission source(s), in tpy. 

(41) Quantifiable. A reliable basis must exist for calculating the amount and the rate of the 

emissions increase or reduction, along with a description of the characteristics of such increase or reduction. 

 The same method must be used to quantify emissions before and after the emissions increase or reduction, 

unless the department approves an alternate method. 

(42) Reasonable further progress. Annual incremental reductions in emissions of a nonattainment 

contaminant required by applicable regulations and implementation plans to ensure timely attainment of the 

corresponding national ambient air quality standard. 

(43) Regulated NSR contaminant. A regulated NSR contaminant is any one of the following: 

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

and any constituents or precursors for such contaminants identified under the Act or by the 

administrator of the US EPA in a promulgated rule; 

(ii) Any contaminant that is subject to any standard promulgated under section 111 of the 

Act; 

(iii) Any Federal Class I or II substance subject to a standard promulgated under or 

established by Title VI of the Clean Air Act; or 
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(iv) Any contaminant that otherwise is subject to regulation under the Clean Air Act; except 

that 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, which have not been delisted pursuant to section 112(b)(3) 

of the Act, are not regulated NSR contaminants unless the listed hazardous air pollutant is also 

regulated as a constituent or precursor of a criteria contaminant listed under section 108 of the Act. 

(44) Secondary emissions. Emissions of a regulated NSR contaminant which will occur as a result 

of the construction or operation of a proposed new or modified facility, not including emissions from the 

proposed new or modified facility itself. Secondary emissions must be specific, well defined, quantifiable, 

and impact the same general area as the proposed new or modified facility which causes the secondary 

emissions. Secondary emissions include regulated NSR contaminant 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 proposed new or modified facility. Secondary emissions do not include any emissions 

which come directly from a mobile source subject to any regulation under Title II of the Clean Air Act, such 

as emissions from a motor vehicle or a train. Secondary emissions will not be considered in an applicability 

determination for a proposed new or modified facility. For the purposes of Subpart 231-12 of this Part, 

secondary emissions must be included during the modeling exercise. 

(45) Significant net emission increase. 

(i) A net emission increase of a nonattainment contaminant at an existing major facility that 

equals or exceeds the applicable significant net emissions increase threshold specified in Tables 3 

and 4 of Subpart 231-13 of this Part; or 
Page 30 of 124 

 

 (ii) A net emission increase of a regulated NSR contaminant at an existing major facility 

located in an attainment area or unclassifiable area under section 7407 of the Act that equals or 

exceeds the applicable significant net emissions increase threshold specified in Table 6 of Subpart 

231-13 of this Part. 

(46) Significant PAL emission source. An emission source that emits or has the potential to emit a 

PAL contaminant in an amount that is equal to or greater than the significant project threshold (as listed in 

Subpart 231-13 of this Part or in the Act, whichever is lower) for that PAL contaminant, but less than the 

amount that would qualify the emission source as a major PAL emission source. 

(47) Source reduction. Any practice which reduces emissions of a regulated NSR contaminant, other 

than a facility shutdown, emission source shutdown, curtailment, or over control of emissions beyond an 

applicable limit. Examples of source reduction would be reformulation of inks, paints, coatings, etc., which 

result in reductions beyond levels required by the most stringent applicable state or federal emission 

limitation, or replacement at the same location, or contiguous locations, of a source with another source 

which emits less to perform the same task, or replacement or repair of valves, fittings, or other equipment to 

reduce fugitive emissions. 

(48) Surplus. A reduction in emissions beyond levels prescribed by the most stringent applicable 

state or federal emission limitation required by the Act. 

Subpart 231-5 New Major Facilities and Modifications to Existing Non-major Facilities in Nonattainment Areas, 

and Attainment Areas of the State within the Ozone Transport Region 
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Section 

231-5.1 Applicability 

231-5.2 Permit application content 

231-5.3 Permit content and terms of issuance 

231-5.4 Lowest achievable emission rate (LAER) 

231-5.5 Emission offset requirements 

231-5.1 Applicability. 

(a) The requirements of this Subpart apply, in nonattainment areas and attainment areas of the state within 

the ozone transport region, to the construction and/or operation of: 

(1) any proposed facility which has the potential to emit a nonattainment contaminant in an amount 

that equals or exceeds the major facility threshold for that contaminant; or 

(2) a modification to an existing non-major facility which has a project emission potential for any 

nonattainment contaminant that equals or exceeds the major facility threshold for that contaminant. 

(b) An existing non-major facility that is located in a nonattainment area or an attainment area of the state 

within the ozone transport region which proposes a modification that has a project emission potential for any 

nonattainment contaminant that does not equal or exceed the applicable major facility threshold, but would result in 

the facility becoming a major facility for such contaminant, is not subject to review under this Subpart. However, 

the facility owner or operator must apply for and obtain a permit in accordance with Part 201 of this Title and the 

permit must contain an emission limit(s) equal to the potential to emit of the emission source(s) affected by the 
Page 32 of 124 

modification. 

231-5.2 Permit application content. 

 The information required in a permit application is set forth in Part 201 of this Title and generally in 

Subpart 231-11 of this Part. In addition, the following information must be included with the permit application at 

the time the application is submitted to the department, unless otherwise specified: 

(a) A certification that all emission sources which are part of any major facility located in New York State 

and under the applicant's ownership or control (or under the ownership or control of any entity which controls, is 

controlled by, or has common control with the applicant) are in compliance, or are on a schedule for compliance, 

with all applicable emission limitations and standards under Chapter III of this title. 

(b) An analysis of alternative sites, sizes, production processes, and environmental control techniques which 

demonstrates that benefits of the proposed new or modified facility significantly outweigh the environmental and 

social costs imposed as a result of its location, construction, or modification within New York State. 

(c) A LAER analysis in accordance with Section 231-5.4 of this Part. 

(d) Emission offset information for VOC or NOx. At the time of the initial permit application or before the 

department issues a final permit determination, the applicant must submit: 

(1) a list which identifies the source(s) of certified or proposed ERCs of VOC or NOx that will be 

used as required emission offsets. This list must include the name and location of the facility, DEC 

identification number, if applicable, and the emission reduction mechanism (i.e., facility shutdown, emission 

unit shutdown, source reduction, curtailment, over-control of emissions beyond an applicable limit). All the 
Page 33 of 124 

proposed ERCs must be certified prior to the issuance of the final permit; and 

(2) a Use of Emission Reduction Credits Form (duly completed and signed by the applicant and an 

authorized representative of the ERC seller) for each ERC source listed in Paragraph 231-5.2(d)(1) of this 

Subdivision. Upon issuance of the permit for the proposed new or modified facility, the NYS ERC Registry 

will be amended to reflect that the ERCs are committed as emission offsets to the proposed new or modified 

facility; and 

(3) for emissions of VOC or NOx in an ozone nonattainment area, documentation of compliance with 

the contribution demonstration required according to the department’s policy documents on air quality 

impact analyses pursuant to Subpart 231-12 of this Part. 

(e) Emission offset information for PM-10 and PM-2.5. The following information must be submitted at the 

time of the initial permit application: 

(1) A list which identifies the source(s) of certified or proposed ERCs of PM-10 or PM-2.5 that will 

be used as required emission offsets. This list must include the name and location of the facility, DEC 

identification number, if applicable, and the emission reduction mechanism (i.e., facility shutdown, emission 

unit shutdown, source reduction, curtailment, over-control of emissions beyond an applicable limit); and 

(2) A Use of Emission Reduction Credits Form (duly completed and signed by the applicant and an 

authorized representative of the ERC seller) for each ERC source listed in Paragraph 231-5.2(e)(1) of this 

Subdivision. Upon issuance of the permit for the proposed new or modified facility, the NYS ERC Registry 

will be amended to reflect that the ERCs are committed as emission offsets to the proposed new or modified 

facility; and 
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(3) An air quality impact evaluation in accordance with the provisions of Subdivision 231-5.5(d) and 

Subpart 231-12 of this Part and the department=s policy document on air quality impact analysis. 

231-5.3 Permit content and terms of issuance. The permit content and terms of issuance are set forth generally in 

Subpart 231-11 of this Part. In addition, the following provisions apply: 

(a) The following emission limitations, as applicable, shall be established in a permit: 

(1) The potential to emit of all applicable nonattainment contaminants of a proposed facility; 

(2) The potential to emit each applicable nonattainment contaminant of a modification at an existing 

non-major facility which has a project emission potential for any nonattainment contaminant that exceeds 

the major facility threshold for that contaminant; 

(3) Any applicable LAER limitation. 

(b) A revised air quality impact evaluation must be submitted if the emission offset list changes after the 

department provides a Notice of Complete Application in accordance with Part 621, and a supplemental public 

notice must be provided in accordance with Section 231-5.3(c) of this Part. 

(c) Supplemental public notice requirements for ERCs used as emission offsets. 

(1) A supplemental public notice is required prior to final permit issuance if the list of facilities 
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providing ERCs for emission offsets is changed or finalized after the date of the Notice of Complete 

Application. Such notice will be provided in accordance with Part 621 of this Title. 

(2) A significant permit modification in accordance with Part 201 of this Title, and supplemental 

public notice are required if the list of facilities providing ERCs is changed after final permit issuance and 

prior to commencement of operation. Such notice will be provided in accordance with Part 621 of this Title. 

(d) A petition for party status pursuant to the supplemental notice provisions based on an offer of proof that 

raises substantive and significant issues related to emission offset requirements of this Part will not be considered as 

late filed petitions for party status pursuant to Part 624 of this Title. 

(e) Offset confirmation prior to the commencement of operation. At least 60 days prior to the date a 

proposed new or modified facility commences operation, the permittee must submit an application to the department 

if there are any proposed changes to the approved list of emission offset sources included in the permit for that 

facility. For each such change, the applicant must submit another Use of Emission Reduction Credits Form signed 

by the applicant and an authorized representative of the new offset source. 

(f) Future ERCs. The permittee must submit prior to permit issuance a copy of each modified permit 

establishing future ERCs and a letter to the department stating that the future reductions have physically 

occurred. The letter shall be submitted as follows: 

(1) no less than 10 working days prior to the date the proposed new or modified facility commences 

operation, except for a functional replacement of an existing emission source(s); or 
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(2) by the conclusion of the facility shakedown period, as identified under Section 231-3.9 of this 

Part, for a functional replacement of an existing emission source(s). 

(g) Canceled or abandoned projects. Prior to the commencement of operation, a facility owner or operator 

may notify the department of their intention to abandon the project and request a return of ERCs committed for use 

as emission offsets. Following the department=s approval of such request and rescission of the permit, the 

department will return the unused ERCs to the ERC Registry. 

231-5.4 Lowest achievable emission rate (LAER). 

(a) For a proposed new or modified facility LAER is required for each emission source which emits a 

nonattainment contaminant for which the new facility or modification is major. 

(b) In establishing the final LAER limit, the department may consider any new information, including recent 

permit decisions, or public comment received, subsequent to the submittal of a complete application. 

(c) LAER will not to be established in final form until the final permit is issued. 

231-5.5 Emission offset requirements. 

(a) Emission offset applicability. 

(1) A proposed new facility which is subject to this Subpart must offset its potential to emit for each 

nonattainment contaminant for which it equals or exceeds the major facility threshold. 

(2) A proposed modification to an existing non-major facility must offset its project emission 
Page 37 of 124 

potential for each nonattainment contaminant for which the project emission potential equals or exceeds the 

major facility threshold. 

(b) Offset ratio. 

 

(1) An emission offset of VOC or NOx as ozone precursors must exceed the corresponding facility 

potential to emit or project emission potential (subsequent to application of LAER), as appropriate, by the 

applicable offset ratio specified in Subpart 231-13 of this Part. A greater offset ratio may be required, on a 

case by case basis, to provide an acceptable contribution demonstration as set forth in this section. 

(2) An emission offset of PM-10 and PM-2.5 must at least equal (offset ratio of one to one or greater) 

the corresponding facility potential to emit or project emission potential (subsequent to application of 

LAER), as appropriate, as indicated in Subpart 231-13 of this Part. A greater offset ratio may be required to 

provide a net air quality benefit as set forth in this section. 

(c) Use of an ERC as part of an emission offset. An ERC must meet the following conditions to be used as 

part of an emission offset: 

(1) For NOx, PM-10, or VOC emissions, ERCs must have physically occurred on or after November 

15, 1990 but need not be contemporaneous; 

(2) For PM-2.5 emissions, ERCs must have physically occurred on or after April 5, 2005 but need 

not be contemporaneous; 
Page 38 of 124 

(3) An ERC, or portion thereof, must be included as a condition in the permit for the proposed new 

or modified facility for which the reduction is used. 

(d) Net air quality benefit and emission offset location for PM-10 or PM-2.5. An emission offset of PM-10 

or PM-2.5 must meet the following: 

(1) Contribution demonstration. An emission offset may be obtained from the same nonattainment 

area in which a proposed new or modified facility is to be located. An emission offset may also be obtained 

from other nonattainment areas of equal or higher classification if emissions from such other areas 

contribute to a violation of the NAAQS for PM-10 or PM-2.5, as applicable, in the nonattainment area 

where the proposed new or modified facility is to be located. 

(2) Net air quality benefit demonstration. As part of a permit application, the applicant must submit 

an air quality impact evaluation in accordance with the department’s policy document on ambient air quality 

impact analysis provisions. The ambient air quality impact analysis must demonstrate that: 

(i) the net impact of the proposed emissions increase and the emission offset provides for a 

net benefit, on balance, in the area affected by the proposed new or modified facility; and 

(ii) for PM-10 only, the net impact in no case exceeds an applicable significant impact level 

of Section 231-12.6 of this Part. 

(3) Interstate offsets. An emission offset of PM-10 or PM-2.5, from areas of equal or higher 

classification may be obtained from another state, provided that an interstate reciprocal trading agreement is 
Page 39 of 124 

in place and the requirements of Paragraphs (1) and (2) of this Subdivision are met. 

(e) Ozone nonattainment and emission offset location. The department’s policy documents on an air quality 

impact analysis must be used by an applicant to find default acceptable VOC or NOx offset source locations within 

New York State or to perform a case specific contribution demonstration. An emission offset of VOC or NOx is 

subject to the following: 

(1) Proposed new or modified facility located in an ozone nonattainment area. 

(i) Intrastate offset sources. An emission offset of VOC or NOx must be obtained from: 

(‘a’) the same ozone nonattainment area, or 

(‘b’) other ozone nonattainment areas of equal or higher classification, if emissions 

from such other areas contribute to a violation of the NAAQS for ozone in the nonattainment 

area where the proposed new or modified facility is to be located. 

(ii) Interstate offset sources. An emission offset may be obtained from other ozone 

nonattainment areas of equal or higher classification in another state, if emissions from such other 

areas contribute to a violation of the NAAQS for ozone in the nonattainment area where the 

proposed new or modified facility is to be located and an interstate reciprocal trading agreement is in 

place. The department’s policy document on an air quality impact analysis may be used by an 

applicant to perform a case specific contribution demonstration. 

(2) Proposed new or modified facility located in an attainment area of the state within the ozone 

transport region. An emission offset of VOC or NOx may be obtained from any location within the ozone 
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transport region. Such an offset may also be obtained from another state in the ozone transport region, 

provided that an interstate reciprocal trading agreement is in place. 

Subpart 231-6 Modifications to Existing Major Facilities in Nonattainment Areas and Attainment Areas of the State 

within the Ozone Transport Region 

 Section 

 231-6.1 Applicability 

231-6.2 Netting 

231-6.3 Permit application content 

231-6.4 Permit content and terms of issuance 

231-6.5 Lowest achievable emission rate, LAER 

231-6.6 Emission offset requirements 

231-6.7 Internal offsets, severe ozone nonattainment area only 

231-6.1 Applicability. 

 The requirements of this Subpart apply to the construction and/or operation of any proposed modification at 

an existing major facility located in a nonattainment area, or an attainment area of the state within the ozone 

transport region as follows: 

(a) For a modification with a project emission potential, calculated utilizing projected actual emissions, 

which does not equal or exceed the applicable significant project threshold in Table 3 or Table 4 of Subpart 231-13 

of this Part, the facility owner or operator must comply with the provisions of Section 231-11.2 of this Part. 

(b) For a modification with a project emission potential which equals or exceeds the applicable significant 
Page 41 of 124 

project threshold in Table 3 or Table 4 of Subpart 231-13 of this Part, but does not result in a NSR major 

modification, the facility owner or operator must comply with the provisions of Section 231-6.2 of this Part. 

(c) For a modification which the facility determines will result in a NSR major modification, the facility 

owner or operator must comply with the provisions of this Subpart as appropriate. 

(d) Special applicability rules for modifications of existing major facilities in severe ozone nonattainment 

areas. 

 (1) Modifications of facilities emitting less than 100 tpy. In the case of any major facility of 

VOC or NOx (other than a facility which emits or has the potential to emit 100 tpy or more of VOC or 

NOx), whenever any modification at the facility results in an NSR major modification of VOC or NOx

from any discrete operation, emission source, or other regulated NSR contaminant emitting activity at the 

facility, such emission increase shall be considered as a modification for purposes of requiring a permit 

under this Part, except that such increase shall not be considered a modification for such purposes if the 

owner or operator of the facility elects to offset the emission increase by a greater reduction in emissions of 

VOC or NOx, as applicable, from other operations, emission sources, or activities within the facility at an 

internal offset ratio of at least 1.3 to one. If the owner or operator does not make such election, the 

modification shall be considered an NSR major modification for such purposes, but in applying control 

requirements, BACT shall be substituted for LAER. 

(2) Modifications of facilities emitting 100 tpy or more. In the case of any major facility of VOC or 

NOx which emits or has the potential to emit 100 tpy or more of VOC or NOx whenever any modification at 

the facility results in an NSR major modification of VOC or NOx from any discrete operation, emission 

source, or other contaminant emitting activity at the facility, such emission increase shall be considered a 
Page 42 of 124 

modification for purposes of requiring a permit under this Part, except that if the owner or operator of the 

facility elects to offset the emission increase by a greater reduction in emissions of VOC or NOx, as 

applicable, from other operations, emission sources, or activities within the facility at an internal offset ratio 

of at least 1.3 to 1, the requirements of LAER shall not apply. 

231-6.2 Netting. 

 This section sets forth the procedures for avoiding a NSR major modification where the proposed 

modification exceeds the significant project threshold(s) but does not result in a significant net emission increase. 

(a) General requirements. 

(1) A net emission increase determination shall be confined to the appropriate contemporaneous 

period for a proposed modification. 

(2) Any ERC which is used in a net emission increase determination must have physically occurred 

on or after the applicable date listed in Subdivision 231-5.5(c) of this Part. 

(3) A net emission increase determination will only be allowed at an existing major facility. 

(4) Any creditable emission increase or ERC must be of the same class of nonattainment 

contaminant. 

(5) Any creditable emission increase or ERC which is used in a net emission increase determination 

must occur at the same major facility as the proposed modification. 
Page 43 of 124 

(6) Any creditable emission increase from an emission source issued a permit for which an emission 

offset or an internal offset was obtained, shall not be considered in any subsequent net emission increase 

determination. 

(b) Permit requirements for netting. A facility owner or operator which proposes a modification that does 

not result in a significant net emission increase, must: 

(1) apply for and obtain a permit which establishes an emission limit that equals the projected actual 

emissions or potential to emit, as appropriate, of the modification of each nonattainment contaminant(s) 

which exceed(s) the applicable significant project threshold. 

(2) apply for and obtain a permit which establishes the ERCs relied on for the net emission increase 

determination, if the ERCs are not already approved by the department. 

(3) submit a Use of Emission Reduction Credits Form (duly completed and signed by the applicant) 

for each source of ERC’s to be used for netting. Upon issuance of the permit for the proposed modification, 

the ERC Registry will be amended to reflect that the ERCs have been committed to the proposed 

modification. 

(4) apply for and obtain a permit which complies with any additional requirements of Subpart 231-

11 of this Part. 

(c) Re-evaluation of a prior net emission increase determination at a facility that was not significant. The 
Page 44 of 124 

facility owner or operator must reevaluate the determination of the net emission increase of a prior modification 

which did not result in a significant net emission increase if a proposed modification will commence operation 

within the contemporaneous period of the prior modification. The facility owner or operator must recalculate the 

net emission increase of the prior modification at the facility by including the project emission potential of the 

proposed modification as a creditable emission increase. If the recalculated net emission increase of the prior 

modification results in a significant net emission increase, taking into account the proposed modification, the facility 

owner or operator must select one of the following options: 

(1) Submit a permit application and accept a condition prohibiting the proposed modification from 

commencing operation until after the close of the contemporaneous period for the previously permitted 

modification; or 

(2) Create additional ERCs according to the provisions of Subpart 231-10 of this Part at the facility 

in an amount which ensures that the net emission increase of the prior modification, after taking into account 

the creditable emission increase of the proposed modification does not result in a significant net emission 

increase; or 

(3) Submit an application requesting modification of the permit for the prior modification which 

reflects the applicability of this Subpart. The facility owner or operator may not begin actual construction of 

the prior modification or begin operation until the department approves the application and issues a permit 

which incorporates the requirements of this Subpart. 

231-6.3 Permit application content. 

The information required in a permit application is set forth in Part 201 of this Title and generally in Subpart 
Page 45 of 124 

231-11 of this Part. The following information must also be included at the time a permit application is submitted to 

the department for a modification which results in a NSR major modification, unless otherwise specified: 

(a) A certification that all emission sources which are part of any major facility located in New York State 

and under the applicant's ownership or control (or under the ownership or control of any entity which controls, is 

controlled by, or has common control with the applicant) are in compliance, or are on a schedule for compliance, 

with all applicable emission limitations and standards under Chapter III of this Title. 

(b) An analysis of alternative sites, sizes, production processes, and environmental control techniques which 

demonstrates that benefits of the proposed project or proposed major facility significantly outweigh the 

environmental and social costs imposed as a result of its location, construction, or modification within New York 

State. 

(c) A LAER analysis in accordance with Section 231-6.5 of this Part. 

(d) Emission offset and internal offset information for VOC or NOx. At the time of the initial permit 

application or before the department issues a final permit determination for a NSR major modification, the applicant 

must submit: 

(1) a list which identifies the source(s) of certified or proposed ERCs of VOC or NOx that will be 

used as an internal offset or required emission offset. This list must include the name and location of the 

facility, DEC identification number, if applicable, and the emission reduction mechanism (i.e., facility 

shutdown, emission unit shutdown, source reduction, curtailment, over-control of emissions beyond an 

applicable limit). All the proposed ERCs must be certified prior to the issuance of the final permit; and 
Page 46 of 124 

(2) a Use of Emission Reduction Credits Form (duly completed and signed by the applicant and an 

authorized representative of the ERC seller) to the department for each ERC source listed in Subparagraph 

231-6.3(d)(1) of this Section. Upon issuance of the permit for the proposed modification, the NYS ERC 

Registry will be amended to reflect that the ERCs are committed as an internal offset or emission offset ,as 

applicable, to the proposed modification; and 

(3) for emissions of VOC or NOx in an ozone nonattainment area, documentation of compliance with 

the contribution demonstration required according to the department’s policy documents on air quality 

impact analyses pursuant to Subpart 231-12 of this Part. 

(e) Emission offset information for PM-10 and PM-2.5. The following information must be submitted at the 

time of the initial permit application for a NSR major modification: 

(1) A list which identifies the source(s) of certified or proposed ERCs of PM-10 or PM-2.5 that will 

be used as required emission offsets. This list must include the name and location of the facility, DEC 

identification number, if applicable, and the emission reduction mechanism (i.e., facility shutdown, emission 

unit shutdown, source reduction, curtailment, over-control of emissions beyond an applicable limit). 

(2) A Use of Emission Reduction Credits Form (duly completed and signed by the applicant and an 

authorized representative of the ERC seller) for each ERC source listed in Subparagraph 231-6.3(e)(1) of 

this Section. Upon issuance of the permit for the proposed modification, the NYS ERC Registry will be 

amended to reflect that the ERCs are committed as emission offsets to the proposed modification. 
Page 47 of 124 

(3) An air quality impact evaluation in accordance with the provisions of Subdivision 231-6.6(d) and 

Subpart 231-12 of this Part and the department’s policy documents on air quality impact analyses. 

231-6.4 Permit content and terms of issuance. 

 The permit content and terms of issuance for an NSR major modification are set forth generally in Subpart 

231-11 of this Part. In addition, the following provisions apply: 

(a) The following emission limitations, as applicable, shall be established in a permit: 

(1) The projected actual emissions or potential to emit, as appropriate, of each applicable 

nonattainment contaminant(s) for a proposed NSR major modification; 

(2) Any LAER limitation. 

(b) A revised air quality impact evaluation must be submitted if the internal offset or emission offset list 

changes after the department provides a Notice of Complete Application in accordance with Part 621 of this Title, 

and a supplemental public notice must be provided in accordance with Subdivision 231-6.4(c) of this Part. 

(c) Supplemental public notice requirements for ERCs used as an internal offset or emission offset. 

(1) A supplemental public notice is required prior to final permit issuance, if the list of ERCs 

provided as internal offsets or emission offsets is changed or finalized after the date the Notice of Complete 

Application. Such notice will be provided in accordance with Part 621 of this Title. 

(2) A permit modification and supplemental public notice are required if the list of ERCs is changed 
Page 48 of 124 

after final permit issuance. Such notice will be provided in accordance with Part 621 of this Title. 

(d) A petition for party status pursuant to the supplemental notice provisions based on an offer of proof that 

raises substantive and significant issues related to internal offset or emission offset requirements of this Part will not 

be considered as late filed petitions for party status pursuant to Part 624 of this Title. 

(e) Offset confirmation prior to the commencement of operation. At least 60 days prior to the date a 

proposed modification commences operation, the permittee must submit an application to the department if there are 

any proposed changes to the approved list of internal offset or emission offset sources included in the permit for that 

facility. For each such change, the applicant must submit another Use of Emission Reduction Credits Form signed 

by the applicant and an authorized representative of the new offset source. 

(f) Future ERCs. The permittee must submit prior to permit issuance a copy of each modified permit 

establishing future ERCs and a letter to the department stating that the future reductions have physically 

occurred. The letter shall be submitted as follows: 

(1) no less than 10 working days prior to the date the proposed new or modified facility commences 

operation, except for a functional replacement of an existing emission source(s); or 

(2) by the conclusion of the facility shakedown period, as identified under Section 231-3.9 of this 

Part, for a functional replacement of an existing emission source(s). 

(g) Canceled or abandoned projects. Prior to the commencement of operation, a facility owner or operator 

may notify the department of their intention to abandon the project and request a return of ERCs committed for use 

as an internal offset or emission offset. Following the department=s approval of such request and rescission of the 
Page 49 of 124 

permit, the department will return the unused ERCs to the ERC Registry. 

231-6.5 Lowest achievable emission rate, LAER. 

(a) For a proposed NSR major modification, LAER is required for each emission source which emits the 

applicable nonattainment contaminant. 

(b) In establishing the final LAER limit, the department may consider any new information, including recent 

permit decisions, or public comment received, subsequent to the submittal of a complete application. 

(c) LAER is not to be established in final form until the final permit for the proposed modification is issued. 

231-6.6 Emission offset requirements. 

(a) Emission offset applicability. For a NSR major modification, the project emission potential must be 

offset. 

(b) Offset ratio. 

(1) An emission offset of VOC or NOx must exceed the corresponding project emission potential, 

subsequent to application of LAER, by the applicable offset ratio specified in Subpart 231-13 of this Part. A 

greater offset ratio may be required, on a case by case basis, to provide an acceptable contribution 

demonstration as set forth in this section. 

(2) An emission offset of PM-10 or PM-2.5 must at least equal (offset ratio of one to one or greater) 

the corresponding project emission potential (subsequent to application of LAER), as indicated in Subpart 

231-13 of this Part. A greater offset ratio may be required to provide a net air quality benefit as set forth in 
Page 50 of 124 

this section. 

(c) Use of an ERC as an emission offset. An ERC must meet the following requirements to be used as an 

emission offset: 

(1) For NOx, PM-10, and VOC emissions, ERCs must have physically occurred on or after 

November 15, 1990 but need not be contemporaneous; 

(2) For PM-2.5 emissions, ERCs must have physically occurred on or after April 5, 2005 but need 

not be contemporaneous; 

(3) An ERC, or portion thereof, must be established in the permit for the proposed NSR major 

modification for which the reduction is used. 

(d) Net air quality benefit and emission offset location for PM-10 or PM-2.5. An emission offset of PM-10 

or PM-2.5 must meet the following requirements: 

(1) Contribution demonstration. An emission offset may be obtained from the same nonattainment 

area in which a proposed NSR major modification is to be located. An emission offset may also be obtained 

from other nonattainment areas of equal or higher classification if emissions from such other areas 

contribute to a violation of the NAAQS for PM-10 or PM-2.5 in the nonattainment area where the proposed 

NSR major modification is to be located. 

(2) Net air quality benefit demonstration. As part of a permit application, the applicant must submit 

an air quality impact evaluation in accordance with department’s policy document on air quality impact 

analysis provisions. The ambient air quality impact analysis must demonstrate that: 
Page 51 of 124 

(i) the net impact of the proposed emissions increase and the emission offset provides for a 

net benefit, on balance, in the area affected by the proposed NSR major modification; and 

(ii) for PM-10 only, the net impact in no case exceeds an applicable significant impact level 

set forth in Section 231-12.6 of this Part. 

(3) Interstate offsets. An emission offset of PM-10 or PM-2.5, from areas of equal or higher 

classification may be obtained from another state, provided that an interstate reciprocal trading agreement is 

in place and the requirements of Paragraphs (1) and (2) of this Subdivision are met. 

(e) Ozone nonattainment and emission offset location. The department’s policy document on air quality 

impact analysis must be used by an applicant to find default acceptable VOC or NOx offset source locations within 

New York State or to perform a case specific contribution demonstration. An emission offset of VOC or NOx is 

subject to the following: 

(1) Proposed NSR major modification located in an ozone nonattainment area. 

(i) Intrastate offset sources. An emission offset of VOC or NOx be obtained from: 

(‘a’) the same ozone nonattainment area, or 

(‘b’) other ozone nonattainment areas of equal or higher classification, if emissions 

from such other areas contribute to a violation of the NAAQS for ozone in the nonattainment 
Page 52 of 124 

area where the proposed NSR major modification is to be located. 

(ii) Interstate offset sources. An emission offset may be obtained from other ozone 

nonattainment areas of equal or higher classification in another state, if emissions from such other 

areas contribute to a violation of the NAAQS for ozone in the nonattainment area where the 

proposed NSR major modification is to be located and an interstate reciprocal trading agreement is 

in place. The department’s policy document on an air quality impact analysis may be used by an 

applicant to perform a case specific contribution demonstration. 

(2) Proposed NSR major modification located in an attainment area of the state within the ozone 

transport region. An emission offset of VOC or NOx may be obtained from any location within the ozone 

transport region. Such an offset may also be obtained from another state in the ozone transport region, 

provided that an interstate reciprocal trading agreement is in place. 

231-6.7 Internal offset requirements, severe ozone nonattainment area only. 

 This section represents a mechanism for avoiding a determination of applicability of this Part, for emissions 

of VOC or NOx in the severe ozone nonattainment area only, in those instances where an NSR major modification is 

proposed at an existing major facility and a net emission increase determination of non-applicability is not possible. 

 

(a) Internal offset applicability. An internal offset shall be considered for purposes of determining 

applicability or degree of control required under Section 231-6.1(d)(1) or (2) of this Part for a proposed NSR 

major modification. 

(b) Use of a NOx or VOC ERC as part of an internal offset. An ERC shall meet the following conditions 

to be used as part of an internal offset: 
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(1) An ERC shall come from an emission source within the same existing major facility as a 

proposed NSR major modification. 

(2) An ERC shall have physically occurred on or after November 15, 1990, but need not be 

contemporaneous with a proposed NSR major modification for which the reduction is used. 

(3) An ERC, or portion thereof, shall be described as a special condition in the permit for the 

proposed NSR major modification for which the reduction is used.

Subpart 231-7 New Major Facilities and Modifications to Existing Non-major Facilities in Attainment Areas 

(Prevention of Significant Deterioration) 

 Section 

 231-7.1 Applicability 

231-7.2 Pre-application analysis 

231-7.3 Permit application content 

231-7.4 General requirements 

231-7.5 Permit content and terms of issuance 

231-7.6 Best available control technology (BACT) 

231-7.1 Applicability. 

(a) The requirements of this Subpart apply in attainment areas of the State to the construction and/or 

operation of: 
Page 54 of 124 

(1) any proposed facility which has the potential to emit a regulated NSR contaminant in an amount 

that equals or exceeds the major facility threshold, in Table 5 of Subpart 231-13 of this Part, for that 

contaminant; or 

(2) a modification to an existing non-major facility which has a project emission potential for any 

regulated NSR contaminant that equals or exceeds the major facility threshold, in Table 5 of Subpart 231-13 

of this Part, for that contaminant. 

(b) An existing non-major facility that is located in an attainment area of the State which proposes a 

modification that has a project emission potential for any regulated NSR contaminant that does not equal or exceed 

the applicable major facility threshold, but would result in the facility becoming a major facility for such 

contaminant, is not subject to review under this Subpart. However, the facility owner or operator must apply for 

and obtain a permit in accordance with Part 201 of this Title and the permit must contain an emission limit(s) equal 

to the potential to emit of the emission source(s) affected by the modification. 

231-7.2 Pre-application analysis. 

 Prior to submitting a permit application, the facility owner or operator must comply with the requirements of 

Section 231-12.3 (Pre-application analysis for Subparts 231-7 and 231-8) of this Part. 

231-7.3 Permit application content. 

 The information required in a permit application is set forth in Part 201 of this Title and generally in Subpart 

231-11 of this Part. In addition, the following information must be included with the permit application at the time 

the application is submitted to the department, unless otherwise specified: 
Page 55 of 124 

(a) Air quality impact analyses according to Subpart 231-12 of this Part. 

(b) A BACT review in accordance with Section 231-7.6 of this Part. 

(c) Source impact analysis. The applicant must demonstrate according to the provisions of Subpart 231-12 

(Ambient Air Quality Impact Analysis) of this Part that allowable emission increases from the proposed new or 

modified facility, in conjunction with all other applicable emissions increases or reductions (including secondary 

emissions), would not cause or significantly contribute to air pollution in violation of: 

(1) any national ambient air quality standard in any air quality control region. 

(2) any applicable maximum allowable increase over the baseline concentration in any area. 

(3) any other applicable requirements identified in Subpart 231-12, and Paragraph 231-7.4(f)(3) of 

this Part including visibility and Air Quality Related Value (AQRV) analyses for Federal Class I areas, as 

applicable. 

(d) Source information. The applicant must submit all information necessary to perform any analysis or 

make any determination required under this section and Subpart 231-12 of this Part, including: 

(1) a detailed description as to what system of continuous emission reduction is planned for the 

facility, emission estimates, and any other information necessary to determine that best available control 

technology would be applied. 
Page 56 of 124 

(2) information on 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 facility would affect, upon request of the department. 

(3) a demonstration of the stack height, consistent with good engineering practice pursuant to 40 

CFR 51.100(ii) and Section 231-7.4(e) of this Part. 

(e) Additional impact analyses. 

(1) The owner or operator must provide an analysis of the impairment to visibility, soils and 

vegetation that would occur as a result of the proposed new or modified facility, and general commercial, 

residential, industrial and other growth associated with the proposed new or modified facility. The owner or 

operator does not have to provide an analysis of the impact on vegetation if the vegetation has no ecological 

or significant commercial or recreational value. 

(2) The owner or operator must 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 proposed new or 

modified facility. 

231-7.4 General requirements. 

 The following provisions are also applicable for the review of applications under this Subpart. 

(a) Ambient air increments. Concentration limitations necessary to assure that in areas designated as Federal 
Page 57 of 124 

Class I, Class II, or Class III, increases in any regulated NSR contaminant concentration over the baseline 

concentration do not exceed those listed in Subpart 231-12 of this Part. 

(b) Ambient air ceilings. For any regulated NSR contaminant for a period of exposure, no concentration of 

that regulated NSR contaminant is allowed to exceed the lower of the following: 

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

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

(c) Restrictions on area classifications and redesignation. 

(1) All areas of the State are designated Class II as identified in department policy documents, but 

may be redesignated as provided in this subdivision. 

(2) The following areas may be redesignated only as Federal Class I: 

(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 

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

exceeds 10,000 acres in size. 

(3) The State may submit to the administrator a proposal to redesignate areas in the State as Class I 
Page 58 of 124 

according to the provisions established by 40 CFR Part 51.166. 

(d) Exclusions from increment consumption. 

(1) The following concentrations must be excluded in determining compliance with the maximum 

allowable ambient air increment: 

(i) Concentrations attributable to the increase in emissions from facilities 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 Federal legislation) over the emissions from such facilities before the effective date 

of such an order. 

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

converted from using natural gas by reason of any applicable natural gas curtailment plan in effect 

pursuant to the Federal Power Act (or any other superseding federal legislation) over the emissions 

from such facilities before the effective date of such plan. 

(iii) Concentrations attributable to the increase in emissions from construction of other 

temporary emission related activities at the facility. 

(iv) Increase in concentrations attributable to new facilities outside the United States over 

the concentrations attributable to existing facilities which are included in the baseline concentration. 

(v) For Subparagraphs (i) and (ii) above, no exclusion of such concentrations applies more 
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than two years after the effective date which is applicable. If both such order and plan are applicable, 

no such exclusion applies more than five years after the later of such effective dates. 

(2) Concentrations attributable to the temporary increase in emissions of SO2, PM, or NOx from 

facilities which are limited to less than one year in duration are excluded, provided the department: 

(i) approves the time over which the temporary emissions increase of SO2, PM, or NOx would 

occur. 

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

subdivision, is not renewable. 

(iii) allows no emissions increase from a facility which would: 

(‘a’) impact a Federal Class I area or an area where an applicable increment is known 

to be violated; or 

(‘b’) cause a violation or contribute to a known violation of a national ambient air 

quality standard. 

(iv) requires limitations to be in effect at the end of the time period specified in accordance 

with this subdivision, which would ensure that the emissions levels from facilities would not exceed 

those levels occurring from such facilities before the exclusion was approved. 
Page 60 of 124 

(e) Stack heights. The degree of emission limitation required for control of any regulated NSR contaminant 

under this Subpart must not be affected in any manner by: 

(1) a stack height, not in existence before December 31, 1970, as exceeds good engineering practice, 

pursuant to 40 CFR 51.100(ii); or 

(2) any other dispersion technique not implemented before December 31, 1970. 

(f) Requirements for sources impacting Federal Class I areas: 

(1) Notice to EPA and Federal Land Manager. The department or the applicant, at the request of the 

department, shall submit a copy of the permit application and all relevant information to the EPA Region 2 

office and the Federal Land Manager within 30 days of receipt of the application. 

(2) Federal Land Manager. The Federal Land Manager and the Federal official charged with direct 

responsibility for management of such lands have an affirmative responsibility to protect the AQRVs 

(including visibility) of such lands and to consider, in consultation with the department, whether a proposed 

new or modified facility will have an adverse impact on such values. 

(3) Visibility analysis and AQRV analysis. The department must consider any analysis performed by 

the Federal Land Manager, provided prior to the date of publication of the draft permit that shows that a 

proposed new major facility may have an adverse impact on visibility or other AQRV in any Federal Class I 

area. Where the department finds that such an analysis does not demonstrate to the satisfaction of the 

department that an adverse impact on visibility or other AQRV will result in the Federal Class I area, the 
Page 61 of 124 

department must, in the notice of public hearing on the permit application, either explain its decision or give 

notice as to where the explanation can be obtained. 

(4) Denial of a permit based on adverse impact on AQRVs. The Federal Land Manager of any such 

lands may demonstrate to the department that the emissions from a proposed new or modified facility would 

have an adverse impact on the AQRVs (including visibility) of those lands, notwithstanding that the change 

in air quality resulting from emissions from the proposed new or modified facility would not cause or 

significantly contribute to concentrations which would exceed the maximum allowable increases for a 

Federal Class I area. If the department concurs with such demonstration, then it must not issue the permit. 

 

(5) Federal Class I variances. The owner or operator of a proposed new or modified facility may 

demonstrate to the Federal Land Manager that the emissions from the new or modified facility would have 

no adverse impact on the air quality related values (including visibility) of any such lands, notwithstanding 

that the change in air quality resulting from emissions from the new or modified facility would cause or 

contribute to concentrations which would exceed the maximum allowable increases for a Federal Class I 

area. If the Federal Land Manager concurs with such demonstration and so certifies, provided that the 

applicable requirements of this section are otherwise met, the State may issue the permit with such emission 

limitations as may be necessary to assure that emissions of SO2, PM, and NOx would not exceed the 

maximum allowable increases over minor source baseline concentration as listed in Table 7 of Subpart 231-

13 of this Part. 

(6) SO2 variance by Governor of the Federal Class I area with Federal Land Manager's concurrence. 

The owner or operator of a proposed new or modified facility which cannot be approved under Paragraph 

231-7.4(f)(4) of this Subdivision may demonstrate to the Governor of the Federal Class I area that the new 
Page 62 of 124 

or modified facility cannot be constructed by reason of any maximum allowable increase for SO2 for a 

period of 24 hours or less applicable to any Federal Class I area, and that a variance under this clause would 

not adversely affect the air quality related values of the area (including visibility). The Governor of the 

Federal Class I area, after consideration of the Federal Land Manager's recommendation (if any) and subject 

to his concurrence, may, after notice and public hearing, grant a variance from such maximum allowable 

increase. If such variance is granted, the department will issue a permit to the new or modified facility, 

provided that the applicable requirements of this Subpart are otherwise met. 

231-7.5 Permit content and terms of issuance. 

 The permit content and terms of issuance are set forth generally in Subpart 231-11. In addition, the 

following emission limitations, as applicable, shall be established in a permit: 

(a) The potential to emit of a proposed facility. 

(b) The potential to emit of a modification at an existing non-major facility which has a project emission 

potential for any regulated NSR contaminant that exceeds the major facility threshold for that contaminant. 

(c) Any BACT limitations. 

231-7.6 Best available control technology, BACT. 

(a) For a proposed new or modified facility, BACT is required for each emission source that is part of the 

proposed new facility or modification, for all regulated NSR contaminants to be emitted by the proposed new 

facility or modification which equal or exceed the applicable significant project threshold listed in Table 6 of 

Subpart 231-13 of this Part. 
Page 63 of 124 

(b) For phased construction projects, the determination of BACT must be reviewed and modified as 

appropriate at the latest 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 applicant may be required to demonstrate 

the adequacy of any previous determination of BACT for the new or modified facility. 

(c) In establishing the final BACT limit, the department may consider any new information, including recent 

permit decisions, or public comment received, subsequent to the submittal of a complete application. 

(d) BACT will not be established in final form until the final permit is issued. 

Subpart 231-8 Modifications to Existing Major Facilities in Attainment Areas (Prevention of Significant 

Deterioration) 

 Section 

 231-8.1 Applicability 

231-8.2 Netting 

231-8.3 Pre-application analysis 

231-8.4 Permit application content 

231-8.5 General requirements 

231-8.6 Permit content and terms of issuance 

231-8.7 Best available control technology, BACT 

231-8.1 Applicability. 
Page 64 of 124 

 The requirements of this Subpart apply to the construction and/or operation of any proposed modification at 

an existing major facility located in an attainment area of the State as follows: 

(a) For a modification with a project emission potential, calculated utilizing projected actual emissions, 

which does not equal or exceed the applicable significant project threshold in Table 6 of Subpart 231-13 of this Part, 

the facility owner or operator must comply with the provisions of Section 231-11.2 of this Part. 

 (b) For a modification with a project emission potential which equals or exceeds the applicable significant 

project threshold in Table 6 of Subpart 231-13 of this Part, but does not result in a NSR major modification, the 

facility owner or operator must comply with the provisions of Section 231-8.2 of this Part. 

(c) For a modification which the facility determines will result in a NSR major modification, the facility 

owner or operator must comply with the provisions of this Subpart as appropriate. 

 

231-8.2 Netting. 

 This section sets forth the procedures for avoiding a NSR major modification where the proposed 

modification exceeds the significant project threshold(s) but does not result in a significant net emission increase. 

(a) General requirements. 

(1) A net emission increase determination shall be confined to the appropriate contemporaneous 

period for a proposed modification. 

(2) A net emission increase determination will only be allowed at an existing major facility. 
Page 65 of 124 

(3) Any creditable emission increase or ERC must be of the same class of regulated NSR 

contaminant. 

(4) Any creditable emission increase or ERC which is used in a net emission increase determination 

must occur at the same major facility as the proposed modification. 

(b) Permit requirements for netting. A facility owner or operator which proposes a modification that does 

not result in a significant net emission increase, must: 

(1) apply for and obtain a permit which establishes an emission limit that equals the projected actual 

emissions or potential to emit, as appropriate, of the modification of each regulated NSR contaminant(s) 

which exceed(s) the applicable significant project threshold. 

(2) apply for and obtain a permit which establishes the ERCs relied on for the net emission increase 

determination, if the ERCs are not already approved by the department. 

(3) submit a Use of Emission Reduction Credits Form (duly completed and signed by the applicant) 

for each source of ERCs to be used for netting. 

(4) apply for and obtain a permit which complies with any additional requirements of Subpart 231-

11 of this Part. 

(c) Re-evaluation of a prior net emission increase determination at a facility that was not significant. The 
Page 66 of 124 

facility owner or operator must reevaluate the determination of the net emission increase of a prior modification 

which did not result in a significant net emission increase if a proposed modification will commence operation 

within the contemporaneous period of the prior modification. The facility owner or operator must recalculate the 

net emission increase of the prior modification at the facility by including the project emission potential of the 

proposed modification as a creditable emission increase. If the recalculated net emission increase of the prior 

modification results in a significant net emission increase, taking into account the proposed modification, the facility 

owner or operator must select one of the following options: 

(1) Submit a permit application and accept a condition prohibiting the proposed modification from 

commencing operation until after the close of the contemporaneous period for the previously permitted 

modification; or 

(2) Create additional ERCs according to the provisions of Subpart 231-10 of this Part at the facility 

in an amount which ensures that the net emission increase of the prior modification, after taking into account 

the creditable emission increase of the proposed modification does not result in a significant net emission 

increase; or 

(3) Submit an application requesting modification of the permit for the prior modification which 

reflects applicability of this Subpart. The facility owner or operator may not begin actual construction of the 

prior modification or begin operation until the department approves the application and issues a permit 

which incorporates the requirements of this Subpart. 

231-8.3 Pre-application analysis. 

 Prior to submitting a permit application, the facility owner or operator must comply with the requirements of 

Section 231-12.3 (Pre-application analysis for Subparts 231-7 and 231-8) of this Part. 
Page 67 of 124 

231-8.4 Permit application content. 

 The information required in a permit application is set forth in Part 201 of this Title and generally in Subpart 

231-11 of this Part. In addition, the following information must be included with the permit application for a NSR 

major modification, at the time the application is submitted to the department, unless otherwise specified: 

(a) An air quality impact analyses according to Subpart 231-12 of this Part. 

(b) A BACT review in accordance with Section 231-8.7 of this Part. 

(c) Source impact analysis. The applicant must demonstrate according to the provisions of Subpart 231-12 

(Ambient Air Quality Impact Analysis) of this Part that allowable emission increases from the proposed 

modification, in conjunction with all other applicable emissions increases or reductions (including secondary 

emissions), would not cause or significantly contribute to air pollution in violation of: 

(1) any national ambient air quality standard in any air quality control region. 

(2) any applicable maximum allowable increase over the baseline concentration in any area. 

(3) any other applicable requirements identified in Subpart 231-12, and Paragraph 231-8.5(f)(3) of 

this Part including visibility and Air Quality Related Value (AQRV) analyses for Federal Class I areas, as 

applicable. 

(d) Source information. The applicant must submit all information necessary to perform any analysis or 
Page 68 of 124 

make any determination required under this section and Subpart 231-12 of this Part, including: 

(1) a detailed description as to what system of continuous emission reduction is planned for the 

facility, emission estimates, and any other information necessary to determine that best available control 

technology would be applied. 

(2) information on 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 facility would affect, upon request of the department. 

(3) a demonstration of the stack height, consistent with good engineering practice pursuant to 40 

CFR 51.100(ii) and Section 231-8.5(e) of this Part. 

(e) Additional impact analyses. 

(1) The owner or operator must provide an analysis of the impairment to visibility, soils and 

vegetation that would occur as a result of the proposed modification, and general commercial, residential, 

industrial and other growth associated with the proposed modification. The owner or operator does not have 

to provide an analysis of the impact on vegetation if the vegetation has no ecological or significant 

commercial or recreational value. 

(2) The owner or operator must 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 proposed 

modification. 
Page 69 of 124 

231-8.5 General requirements. The following provisions are also applicable for the review of applications under this 

Subpart. 

(a) Ambient air increments. Concentration limitations necessary to assure that in areas designated as Federal 

Class I, Class II, or Class III, increases in any regulated NSR contaminant concentration over the baseline 

concentration do not exceed those listed in Subpart 231-12 of this Part. 

(b) Ambient air ceilings. For any regulated NSR contaminant for a period of exposure, no concentration of 

that regulated NSR contaminant is allowed to exceed the lower of the following: 

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

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

(c) Restrictions on area classifications and Redesignation. 

(1) All areas of the State are designated Class II as identified in department policy documents, but 

may be redesignated as provided in this Subdivision. 

(2) The following areas may be redesignated only as Federal Class I: 

(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 
Page 70 of 124 

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

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

exceeds 10,000 acres in size. 

(3) The State may submit to the administrator a proposal to redesignate areas in the State as Class I 

according to the provisions established by 40 CFR Part 51.166. 

(d) Exclusions from increment consumption. 

(1) The following concentrations must be excluded in determining compliance with the maximum 

allowable ambient air increment: 

(i) Concentrations attributable to the increase in emissions from facilities 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 federal legislation) over the emissions from such facilities before the effective date 

of such an order. 

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

converted from using natural gas by reason of any applicable natural gas curtailment plan in effect 

pursuant to the Federal Power Act (or any other superseding federal legislation) over the emissions 

from such facilities before the effective date of such plan. 

(iii) Concentrations attributable to the increase in emissions from construction of other 
Page 71 of 124 

temporary emission related activities at the facility. 

(iv) Increase in concentrations attributable to new facilities outside the United States over the 

concentrations attributable to existing facilities which are included in the baseline concentration. 

(v) For Subparagraphs (i) and (ii) above, no exclusion of such concentrations applies more 

than two years after the effective date which is applicable. If both such order and plan are 

applicable, no such exclusion applies more than five years after the later of such effective dates. 

(2) Concentrations attributable to the temporary increase in emissions of SO2, PM, or NOx from 

facilities which are limited to less than one year in duration are excluded, provided the department: 

(i) approves the time over which the temporary emissions increase of SO2, PM, or NOx

would occur. 

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

subdivision, is not renewable. 

(iii) allows no emissions increase from a facility which would: 

(‘a’) impact a Federal Class I area or an area where an applicable increment is known 

to be violated; or 

(‘b’) cause a violation or contribute to a known violation of a national ambient air 

quality standard. 
Page 72 of 124 

(iv) requires limitations to be in effect at the end of the time period specified in accordance 

with this subdivision, which would ensure that the emissions levels from facilities would not exceed 

those levels occurring from such facilities before the exclusion was approved. 

(e) Stack heights. The degree of emission limitation required for control of any regulated NSR contaminant 

under this Subpart must not be affected in any manner by: 

(1) a stack height, not in existence before December 31, 1970, as exceeds good engineering practice, 

pursuant to 40 CFR 51.100(ii); or 

(2) any other dispersion technique not implemented before December 31, 1970. 

(f) Requirements for sources impacting Federal Class I areas: 

(1) Notice to EPA and Federal Land Manager. The department or the applicant, at the request of the 

department, shall submit a copy of the permit application and all relevant information to the EPA Region 2 

office and the Federal Land Manager within 30 days of receipt of the application. 

(2) Federal Land Manager. The Federal Land Manager and the Federal official charged with direct 

responsibility for management of such lands have an affirmative responsibility to protect the AQRVs 

(including visibility) of such lands and to consider, in consultation with the department, whether a proposed 

new or modified facility will have an adverse impact on such values. 
Page 73 of 124 

(3) Visibility analysis and AQRV analysis. The department must consider any analysis performed by 

the Federal Land Manager, provided prior to the date of publication of the draft permit that shows that a 

proposed new major facility may have an adverse impact on visibility or other AQRV in any Federal Class I 

area. Where the department finds that such an analysis does not demonstrate to the satisfaction of the 

department that an adverse impact on visibility or other AQRV will result in the Federal Class I area, the 

department must, in the notice of public hearing on the permit application, either explain its decision or give 

notice as to where the explanation can be obtained. 

(4) Denial of a permit based on adverse impact on AQRVs. The Federal Land Manager of any such 

lands may demonstrate to the department that the emissions from a proposed new or modified facility would 

have an adverse impact on the AQRVs (including visibility) of those lands, notwithstanding that the change 

in air quality resulting from emissions from the proposed new or modified facility would not cause or 

significantly contribute to concentrations which would exceed the maximum allowable increases for a 

Federal Class I area. If the department concurs with such demonstration, then it must not issue the permit. 

 

(5) Federal Class I variances. The owner or operator of a proposed new or modified facility may 

demonstrate to the Federal Land Manager that the emissions from the new or modified facility would have 

no adverse impact on the air quality related values (including visibility) of any such lands, notwithstanding 

that the change in air quality resulting from emissions from the new or modified facility would cause or 

contribute to concentrations which would exceed the maximum allowable increases for a Federal Class I 

area. If the Federal Land Manager concurs with such demonstration and so certifies, provided that the 

applicable requirements of this section are otherwise met, the State may issue the permit with such emission 

limitations as may be necessary to assure that emissions of SO2, PM, and NOx would not exceed the 

maximum allowable increases over minor source baseline concentration as listed in Table 7 of Subpart 231-
Page 74 of 124 

13 of this Part. 

(6) SO2 variance by Governor of the Federal Class I area with Federal Land Manager's concurrence. 

The owner or operator of a proposed new or modified facility which cannot be approved under Paragraph 

231-8.5(f)(4) of this Subdivision may demonstrate to the Governor of the Federal Class I area that the new 

or modified facility cannot be constructed by reason of any maximum allowable increase for SO2 for a 

period of 24 hours or less applicable to any Federal Class I area, and that a variance under this Clause would 

not adversely affect the air quality related values of the area (including visibility). The Governor of the 

Federal Class I area, after consideration of the Federal Land Manager's recommendation (if any) and subject 

to his concurrence, may, after notice and public hearing, grant a variance from such maximum allowable 

increase. If such variance is granted, the department will issue a permit to the new or modified facility, 

provided that the applicable requirements of this Subpart are otherwise met. 

231-8.6 Permit content and terms of issuance. 

 The permit content and terms of issuance for a NSR major modification are set forth generally in Subpart 

231-11 of this Part. In addition, the following emission limitations, as applicable, shall be established in a permit: 

(a) The projected actual emissions or potential to emit, as appropriate of each applicable regulated NSR 

contaminant(s) for a proposed NSR major modification. 

(b) Any BACT limitations. 

231-8.7 Best available control technology, BACT. 

(a) For a proposed NSR major modification BACT is required for each emission source that is part of the 

proposed modification, for all regulated NSR contaminants to be emitted by the proposed modification which equal 
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or exceed the applicable significant project threshold listed in Table 6 of Subpart 231-13 of this Part. 

 (b) For phased construction projects, the determination of BACT must be reviewed and modified as 

appropriate at the latest 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 applicant may be required to demonstrate 

the adequacy of any previous determination of BACT for the modification. 

(c) In establishing the final BACT limit, the department may consider any new information, including recent 

permit decisions, or public comment received, subsequent to the submittal of a complete application. 

(d) BACT will not be established in final form until the final permit is issued. 

Subpart 231-9 Plantwide Applicability Limitation (PAL). 

 Section 

 231-9.1 General provisions 

231-9.2 Permit application requirements 

231-9.3 Permit processing 

231-9.4 Setting the initial PAL 

231-9.5 Permit contents 

231-9.6 Permit modifications and reopenings 

231-9.7 PAL renewals and expirations 

231-9.1 General provisions. 

(a) Upon request of an applicant, the department shall establish a PAL at an existing major facility, provided 

that at a minimum, the following provisions are met: 
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(1) The PAL must impose a facility-wide annual emission limitation in tpy that is included in the 

Part 201 permit for the facility. 

(i) For each month during the PAL effective period after the first 12 months following the 

PAL effective date, the facility must show that the sum of the monthly emissions from each emission 

source under the PAL for the previous 12 consecutive months is less than the PAL (a 12-month total 

rolled monthly). 

(ii) For each month during the first 11 months following the PAL effective date, the facility 

must demonstrate that the sum of the preceding monthly emissions from the PAL effective date for 

each emission source under the PAL is less than the PAL. 

(2) The PAL must include fugitive emissions, to the extent quantifiable, from all emission sources 

that emit or have the potential to emit the PAL contaminant. 

(3) Each PAL shall establish an emission limit for only one PAL contaminant. 

(4) Each PAL shall have a PAL effective period as defined in Section 231-4.1 of this Part. 

(5) At no time (during or after the PAL effective period) are emissions reductions of a PAL 

contaminant that occur during the PAL effective period creditable as decreases for purposes of establishing 

emission offsets under this Part 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. 
Page 77 of 124 

(b) Any physical change or change in the method of operation of a major facility that maintains its total 

facility wide emissions below the PAL level, and is otherwise consistent with the requirements of this Subpart, will 

not be considered a NSR major modification for the PAL contaminant and is not subject to this Part. 

(c) A facility must continue to comply with all applicable requirements, including any terms and conditions 

of the facility=s Part 201 permit that were in effect prior to the effective date of the PAL. 

231-9.2 Permit application requirements. 

 As part of a permit application requesting a PAL, the owner or operator of a major facility must submit the 

following information: 

(a) A list of all emission sources at the facility. 

(b) For each emission source: 

(1) The potential to emit of the PAL contaminant. 

(2) The applicable requirements for that emission source. 

(3) The baseline actual emissions (with supporting documentation). 

(c) The methodology that the facility is proposing to use for conversion of the monitoring system data to 

monthly and annual emissions based on a 12-month rolling total for each month. 
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 (d) If the applicant seeks to utilize Section 231-9.4(e)(2) of this Part as the basis for calculating the reduced 

PAL level, the applicant shall provide, as applicable, a BACT review in accordance with Section 231-8.7 of this 

Part and/or a LAER analysis in accordance with Section 231-6.5 of this Part. 

231-9.3 Permit Processing. 

(a) A permit application requesting the establishment of a PAL will be treated as a major permit 

modification for the Title V permit and be processed in accordance with the procedures in Parts 201 and 621 of this 

Title. 

(b) A request to renew a PAL must be included in the application to renew the Title V permit and will be 

processed in accordance with the procedures in Parts 201 and 621 of this Title. 

231-9.4 Setting the initial PAL. 

 The PAL for a facility must be calculated as the sum of the baseline actual emissions of the PAL 

contaminant for each emission source at the facility plus an amount equal to the applicable significant project 

threshold for the PAL contaminant under Subpart 231-13 of this Part or under the Act, whichever is lower. 

(a) When establishing the PAL for a particular PAL contaminant, only one 24 consecutive month period may 

be used to determine the baseline actual emissions for all emission sources. However, a different 24 consecutive 

month period may be used for each different PAL contaminant. 

(b) Emissions associated with emission sources that were permanently shut down after this 24 consecutive 

month period must be subtracted from the PAL calculation. 
Page 79 of 124 

(c) Emissions from a permitted emission source or an exempt or trivial emission source on which actual 

construction began after the 24 consecutive month period, but has not yet commenced operation, must be added to 

the PAL calculation in an amount equal to the potential to emit of the emission source. 

(d) Where the department is aware of any future applicable requirement(s), prior to issuance of the permit 

which establishes the PAL, the department will specify a reduced PAL in the permit to become effective on the 

future compliance date(s) of the applicable requirement(s). For example, if the facility will be required to reduce 

emissions from industrial boilers in half from baseline emissions of 60 ppm NOx to a new rule limit of 30 ppm, the 

permit must contain a future effective PAL that is equal to the current PAL reduced by half of the original baseline 

emissions of such emission source(s). 

(e) Commencing with the first day of the sixth year of the PAL, the PAL shall be reduced as follows: 

(1) The PAL level shall be reduced to 75 percent of the initial PAL level unless the owner or 

operator demonstrates that a lesser level of reduction is justified in accordance with Paragraph (2). 

(2) The owner or operator may seek an alternative reduced PAL level by demonstrating, at the time 

of application for the PAL, that application of BACT and/or LAER (depending on whether attainment or 

nonattainment requirements apply) on all major PAL emission sources at the facility would not result in a 25 

percent reduction in the initial PAL level, assuming operation of those major PAL emission sources at full 

capacity. In its application for a PAL, the owner or operator shall provide, as applicable, a BACT review in 

accordance with Section 231-8.7 of this Part and/or a LAER analysis in accordance with Section 231-6.5 of 

this Part. Based on the information provided, the department may, in its sole discretion, authorize a 
Page 80 of 124 

reduction in the PAL to a level that would reflect the emissions from the facility if all major PAL emission 

sources are operated at full capacity after complying with BACT and/or LAER, as applicable. In making 

these determinations, emissions from minor PAL emissions sources shall be held constant at the initial 

baseline levels. In no event shall the reduced PAL level calculated in this paragraph exceed the initial PAL 

level set in Subdivisions (a) through (d) of this Section.

231-9.5 Permit contents. The following terms and conditions, at a minimum, must be included in a permit which 

establishes a PAL: 

(a) The PAL contaminant, the applicable facility-wide emission limitation in tpy, and required monitoring 

provisions consistent with this section. 

(b) The effective date of the permit and the expiration date of the PAL (PAL effective period). 

(c) The emissions calculations to be used for compliance purposes. These calculations must include 

emissions from start-ups, shutdowns, and malfunctions. 

(d) The procedures to convert the monitoring system data to monthly emissions and annual emissions based 

on a 12-month rolling total as required by this Subpart. 

(e) Monitoring requirements. 

(1) General requirements. 
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(i) A requirement that the monitoring system accurately determines facility emissions of the 

PAL contaminant in terms of mass per unit of time according to the criteria contained in the 

following Paragraphs as applicable. 

(ii) The PAL monitoring system must employ one or more of the four monitoring approaches 

meeting the minimum requirements set forth in Paragraph 231-9.5(e)(2) of this Part. If the facility 

utilizes CEMS to monitor a particular contaminant for which a PAL is sought, the facility must use 

the CEMS to monitor that contaminant. 

(2) Minimum performance requirements for approved monitoring approaches. The following are 

acceptable monitoring approaches when conducted in accordance with the minimum requirements in 

Paragraphs 231-9.5(e)(3) through (9) of this Part: 

(i) Mass balance calculations for activities using coatings or solvents. 

(ii) CEMS. 

(iii) Other monitoring systems as approved by the department. 

(iv) Emission factors. 

(3) Mass balance calculations. A facility using mass balance calculations to monitor PAL 

contaminant emissions from activities using coating or solvents must meet the following requirements: 
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(i) Provide a demonstrated means of validating the published content of the PAL contaminant 

that is contained in or created by all materials used in or at the emission source. 

(ii) Assume that the emission source emits all the PAL contaminant that is contained in or 

created by any raw material or fuel used in or at the emission source, if it cannot otherwise be 

accounted for in the process. 

(iii) Where the vendor of a material or fuel, which is used in or at the emission source, 

publishes a range of contaminant content from such material, the facility must use the highest value 

of the range to calculate the PAL contaminant emissions unless the department determines there is 

site-specific data or a site-specific monitoring program to support another content within the range. 

(4) CEMS. A facility using CEMS to monitor PAL contaminant emissions must meet the following 

requirements: 

(i) CEMS must comply with applicable Performance Specifications found in 40 CFR Part 60, 

appendix B. 

(ii) CEMS must sample, analyze and record data at least every 15 minutes while the emission 

source is operating. 

(5) Other monitoring systems. A facility using other monitoring systems to monitor PAL 

contaminant emissions must meet the following requirements: 

(i) The monitoring system must be based on current site-specific data demonstrating a 
Page 83 of 124 

correlation between the monitored parameter(s) and the PAL contaminant emissions across the range 

of operation of the emission source. 

(ii) Each monitoring system must sample, analyze, and record data at least every 15 minutes, 

or at another less frequent interval approved by the department, while the emission source is 

operating. 

(6) Emission factors. A facility using emission factors to monitor PAL contaminant emissions must 

meet the following requirements: 

(i) All emission factors must be adjusted, if appropriate, to account for the degree of 

uncertainty or limitations in the factors development. 

(ii) The emission source must operate within the designated range of use for the emission 

factor, if applicable. 

(iii) If technically practicable, any facility with a significant PAL emission source that relies 

on an emission factor to calculate PAL contaminant emissions must conduct validation testing to 

determine a site-specific emission factor within six months of permit issuance, unless the department 

determines that testing is not required. 

(7) A facility owner or operator must record and report maximum potential emissions without 

considering enforceable emission limitations or operational restrictions for an emission source during any 

period of time that there is no monitoring data, unless another method for determining emissions during such 

periods is specified in the permit. 
Page 84 of 124 

(8) Notwithstanding the requirements in Subdivisions 231-9.5(e)(3) through (7) of this Part, where 

an owner or operator of a facility cannot demonstrate a correlation between the monitored parameter(s) and 

the PAL contaminant emissions rate at all operating points of the emission source, the department must 

include in the permit default value(s) for determining compliance with the PAL based on the highest 

potential emissions reasonably estimated at such operating point(s). Alternatively, the department must 

determine that operation of the emission source during circumstances where there is no correlation between 

monitored parameter(s) and the PAL contaminant emissions is a violation of the PAL. 

(9) Re-validation. All data used to establish the PAL contaminant must be re-validated through 

performance testing or other scientifically valid means approved by the department. Such testing must 

occur at least once every five years after issuance of the PAL. 

(f) Recordkeeping requirements. 

(1) The facility must retain a copy of all records necessary to determine compliance with any 

requirement of this Subpart and of the PAL, including a determination of each emission source=s 12-month 

rolling total emissions, for five years from the date of such record. 

(2) The facility must retain a copy of the following records for the duration of the PAL effective 

period plus five years: 

(i) A copy of the permit application and any applications for revisions to the PAL. 
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(ii) Each annual certification of compliance pursuant to Part 201 of this Title and the data 

relied on for such certification. 

(3) The records must be maintained on-site or at an alternative location approved by the department. 

 Such records may be retained in an electronic format. 

(g) Reporting and notification requirements. Semi-annual monitoring reports and prompt deviation reports 

must be submitted to the department. The reports must meet the requirements in this section and Subpart 231-11 of 

this Part. 

(1) Semi-annual report. The semi-annual report must be submitted to the department within 30 days 

of the end of each reporting period, and include the following: 

(i) Total annual emissions (tons/year) based on a 12-month rolling total for each month in the 

reporting period recorded pursuant to Section 231-9.5(f)(1) of this Part. 

(ii) All data relied upon, including, but not limited to, any Quality Assurance or Quality 

Control data, in calculating the monthly and annual PAL contaminant emissions. 

(iii) A list of any emission sources modified or added to the major facility during the 

preceding six-month period. 

(iv) 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. 
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(v) 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 

emission source monitored by the monitoring system continued to operate, and the calculation of the 

emissions of the PAL contaminant or the number determined by method included in the permit, as 

provided by Subdivision 231-9.5(e)(7) of this Part. 

(2) Deviation report. The major facility owner or operator must promptly submit a report of any 

deviations or exceedance of the PAL requirements, including periods where no monitoring is available. 

The deviation report must be submitted within the time limits prescribed by Part 201 of this Title and the 

Title V permit. A deviation report submitted in accordance with Subpart 201-6 of this Title will satisfy this 

reporting requirement. The report must contain, among other information required under Subpart 201-6 of 

this Title, identification of the owner or operator, the PAL requirement that experienced the deviation or that 

was exceeded, emissions resulting from the deviation or exceedance, and a signed statement by the 

responsible official as defined by the applicable Title V permit certifying the truth, accuracy, and 

completeness of the information contained in the report. 

(3) Re-validation results. The owner or operator must submit to the department the results of any revalidation test or method within three months after completion of such test or method. 

(h) Provisions which implement the monitoring, recordkeeping, and reporting and notification requirements 

contained in this Subpart and any other requirements that the department deems necessary to implement and enforce 

the PAL. 
Page 87 of 124 

231-9.6 Permit modifications and reopenings. 

(a) Permit reopening to revise a PAL. The following provisions apply to permit reopenings to revise a PAL. 

(1) During the PAL effective period, the department must reopen the permit to: 

(i) correct typographical/calculation errors made in setting the PAL or reflect a more accurate 

determination of emissions used to establish the PAL. 

(ii) reduce the PAL if the facility creates creditable emissions reductions for use as emission 

offsets under this Part. 

(iii) revise the PAL to reflect an increase in the PAL as provided under Subdivision 231-

9.6(b) of this Part. 

(2) The department retains discretion to reopen the permit for the following: 

(i) Reduce the PAL to reflect new applicable requirements with compliance dates after the 

PAL effective date. 

(ii) Reduce the PAL consistent with any other requirement the State may impose on the 

major facility under the State Implementation Plan. 

(iii) Reduce the PAL if the department 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 air 

quality related value that has been identified for a Federal Class I area by a Federal Land Manager 
Page 88 of 124 

and for which information is available to the general public. 

(3) Except for permit reopenings for the correction of typographical or calculation errors that do not 

increase the PAL, all other reopenings must be processed in accordance with the procedures in Parts 201 and 

621 of this Title for a major permit modification. 

(b) Increasing a PAL during the PAL effective period. 

(1) Upon request of an applicant, the department may increase a PAL during the PAL effective 

period provided all of the following provisions are met: 

(i) A complete application for a significant Part 201 of this Title permit modification is 

submitted in accordance with the provisions of Parts 201 and 621 of this Title requesting an increase 

in the PAL. Such application must identify the emission source(s) which will have additional 

emissions that will cause the emissions of the facility to equal or exceed its current PAL. 

(ii) As part of this application, the facility must demonstrate that the sum of the following 

two items will exceed the existing PAL: 

(‘a’) For all new or modified emission sources, the sum of the potential to emit of 

each emission source; and 

 

(‘b’) For all other emission sources: 
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‘(1)’ the sum of baseline actual emissions of all the minor PAL emission 

sources; and 

‘(2)’ the sum of baseline actual emissions of all the significant and major 

PAL emission sources assuming application of BACT or LAER equivalent controls 

as appropriate. 

The level of control that would result from the application of BACT or LAER 

equivalent controls on each significant or major emission source must be determined by 

conducting a new BACT or LAER analysis at the time the application is submitted, unless 

the emission source 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 emission source must be equal to the level of BACT or LAER with which that emission 

source must currently comply. 

(iii) The facility must obtain a permit modification that includes all emission source(s) 

identified in Subparagraph 231-9.6(b)(1)(i) of this Title, regardless of the magnitude of the 

emissions increase resulting from them. These emission source(s) must continue to comply with any 

other applicable requirements contained in the Part 201 of this Title permit even though they have 

also become subject to the PAL or continue to be subject to the PAL. 

(2) Permit contents. The following provisions, in addition to the other requirements of this Subpart, 

must be included in the permit authorizing the increased PAL: 

(i) A provision that the increased PAL will be effective on the date any emission source that 
Page 90 of 124 

is part of the PAL modification becomes operational and begins to emit the PAL contaminant. 

(ii) The new PAL shall be calculated as the sum of the facility potential to emit for each 

proposed new or modified emission source, plus the sum of the baseline actual emissions of the 

significant and major emission sources (assuming application of BACT or LAER equivalent controls 

as determined in accordance with Subparagraph 231-9.6[b][1][ii]) of this Part, plus the sum of the 

baseline actual emissions of each minor PAL emission source. 

231-9.7 PAL renewals and expirations. 

(a) Permit renewal where PAL is not renewed. The following provisions set forth the requirements for an 

application to renew a Title V permit where a PAL will expire at the end of the PAL effective period and the facility 

has not included a request to renew the PAL in such application. The facility must continue to comply with the PAL 

until such time as the department issues a renewed Title V permit. 

(1) Application Content. In addition to any other information required pursuant to this Chapter, the 

Title V permit application must include a proposed allowable emission limitation for each emission source. 

Such emission limitations must be calculated by distributing the PAL of the facility among each emission 

source that is subject to an emission limitation under the PAL and must be adjusted to reflect any applicable 

requirements that became effective during the PAL effective period if the PAL was not previously adjusted. 

(2) Permit Content. In addition to any other requirements of this Chapter, a Title V permit issued 

following the expiration of a PAL shall include the following provisions: 

(i) Emission limits for each emission source on a 12-month rolling basis. The allowable 
Page 91 of 124 

emission limits shall be established in accordance with a distribution of the PAL that the department 

determines is appropriate. 

(ii) A facility must demonstrate compliance with the allowable emission limitation(s) through 

the use of CEMS or other monitoring systems (source testing, emission factors, etc.) as the 

department may approve. 

(b) Permit renewal where a PAL is renewed. 

(1) Application deadline. The application deadlines for renewal of the Title V permits in Part 201 of 

this Title shall govern the application to renew a PAL. 

(2) Application content. The application to renew a permit with a PAL must contain the following 

information: 

(i) The information required in Subdivisions 231-9.2(a) through (c) of this Part. 

(ii) A proposed PAL. 

(iii) The sum of the potential to emit of all emission sources subject to the PAL with 

supporting documentation. 

(iv) Any other relevant information the owner or operator submits to the department for 

consideration in determining the appropriate level for renewing the PAL. 

 
Page 92 of 124 

(3) PAL adjustment. In determining whether and how to adjust the PAL, the department must 

consider the options outlined below. All adjustments must comply with Subparagraph (iii) below. 

(i) If the emissions level calculated in accordance with Subdivisions 231-9.4(a) through (d) 

of this Part is equal to or greater than 80 percent of the level of the existing PAL at the time of 

renewal, the department may renew the PAL at the same level, without considering the factors set 

forth in Subparagraph (ii) below; or 

(ii) The department may set the PAL at a level that the department determines is more 

representative of the baseline actual emissions of the facility, or is more appropriate considering air 

quality needs, advances in control technology, anticipated economic growth in the area, desire to 

reward or encourage voluntary emissions reductions at the facility, or other factors as specifically 

identified by the department. 

(iii) Notwithstanding Subparagraphs (i) and (ii) above: 

(‘a’) if the potential to emit of the facility is less than the PAL, the department must 

adjust the PAL to a level no greater than the potential to emit of the facility; and 

(‘b’) the department cannot approve a renewed PAL higher than the current PAL, 

unless the facility has complied with the provisions of Section 231-9.6(b) of this Part. 

(iv) Subdivision 231-9.4(e) of this Part is inapplicable to the renewal of a PAL. 

(4) If the compliance date for an applicable requirement occurs during the PAL effective period, and 
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the department has not already adjusted the PAL to reflect such requirement, the PAL must be adjusted at 

the time of permit renewal. 

Subpart 231-10 Emission Reduction Credits (ERCs) 

 Section 

 231-10.1 General provisions 

231-10.2 Determination of ERCs 

231-10.3 Applications for ERC approval 

231-10.4 Permit application processing 

231-10.5 Permit requirements 

231-10.6 ERC registry 

231-10.7 Mobile source and demand side management ERCs 

231-10.8 Replacement and relocation of emission sources 

231-10.1 General provisions. 

(a) An ERC may be used in a net emission increase determination, internal offset, or as an emission offset. 

(b) An ERC may be used as an internal offset or emission offset, as applicable, without time limit or 

restriction within New York State. In another State in the Ozone Transport Region, an ERC may be used as an 

emission offset in accordance with that State=s requirements if New York State has established a reciprocal trading 

agreement with that State. 

(c) An ERC must be the same type of regulated NSR contaminant as the emission increase requiring ERCs. 

For example, only a particulate form of emission reduction is allowed to be used as an emission offset or in netting 

for new particulate emissions. 
Page 94 of 124 

(d) An ERC may include emission reductions from control or elimination of fugitive emissions, provided 

these emissions are contained in the New York State emissions inventory. 

(e) An ERC, or portion thereof, which was used to avoid a determination of a significant net emission 

increase, as an internal offset, or as an emission offset cannot subsequently be used for demonstrating attainment 

with ambient air quality standards or reasonable further progress in a federally approved SIP. 

(f) An ERC, or portion thereof, which was used to avoid a determination of a significant net emission 

increase, cannot subsequently be used as an internal offset, emission offset, or in any subsequent netting 

determinations. 

(g) An ERC, or portion thereof, which was used as an internal offset or an emission offset cannot be used 

again for any purpose. 

(h) An ERC of NOx, PM-10, or VOC used as an emission offset or for netting, for compliance with Subparts 

231-5 or 231- 6 of this Part, must have physically occurred on or after November 15, 1990 but need not be 

contemporaneous. 

(i) An ERC of PM-2.5 used as an emission offset or for netting, for compliance with Subparts 231-5 or 231- 

6 of this Part, must have physically occurred on or after April 5, 2005 but need not be contemporaneous. 

(j) An ERC used as an internal offset for NOx or VOC emissions must have physically occurred on or after 

November 15, 1990 but need not be contemporaneous. 
Page 95 of 124 

(k) The department will approve applications for ERCs submitted on or after the effective date of this 

regulation on an emission source basis. Applications submitted prior to the effective date of this regulation will be 

processed according to the provisions of Subpart 231-2 of this Part. 

(l) ERCs may be created from past or future emission reductions resulting from facility shutdown, emission 

source shutdown, curtailment, emission source reduction, over-control of emissions beyond an applicable limit, or 

any other reduction mechanism acceptable to the department. 

(m) The department may approve future emission reductions only if they are designated for a specific 

facility. The facility seeking to establish the future emission reductions must submit an application to the 

department for modification of its Part 201 permit. The permit of the facility proposing to use the future emission 

reductions must identify the source(s) of the reductions. The permit of the facility establishing the future emission 

reductions is subject to modification by the department to remove the approval of the future emission reductions if 

the facility proposing to use the future emission reductions does not commence construction within the time period 

specified in this Part, or if the applicant notifies the department of its intent to abandon the proposed new or 

modified facility and the applicant surrenders the permit prior to commencement of operation. 

(n) Emission reductions resulting from the shutdown of an unpermitted emission source which was subject 

to the requirement to obtain a permit pursuant to Part 201 of this Title will not be certified as ERCs. 

(o) Unpermitted emission sources that are operational may be considered for ERCs in accordance with this 

Part subsequent to being permitted in accordance with Part 201 of this Title. 
Page 96 of 124 

231-10.2 Determination of ERCs. Any decrease in emissions of a regulated NSR contaminant, in tpy, which: 

(a) is surplus, quantifiable, permanent, enforceable, and included in a Part 201 permit; and 

(b) will result or resulted from a physical change in, or a change in the method of operation of an emission 

source subject to Part 201of this Title: 

(1) is quantified as the difference between baseline actual and the subsequent potential to emit. 

(2) is certified in accordance with the provisions of this Part; or 

 

(c) will result or resulted from a physical change in, or a change in the method of operation of an emission 

source not subject to Part 201 of this Title, and is certified in accordance with the provisions of this Part. 

231-10.3 Applications for ERC approval. 

 This section applies to applications for ERCs at sources subject to Part 201. 

(a) Application procedures. 

(1) For approval of ERCs from a facility subject to Subpart 201-5 or Subpart 201-6 of this Title, 

other than a facility shutdown, the facility owner or operator must submit an application for a permit 

modification. 
Page 97 of 124 

(2) For approval of ERCs from a registered facility, other than a facility shutdown, the owner or 

operator must apply for a state facility permit. 

(3) For approval of ERC=s as a result of shutdown of a facility subject to Subpart 201-5 or Subpart 

201-6 of this Title, the facility owner or operator must submit a written request to the department to 

discontinue the permit. 

(4) For approval of ERC=s as a result of shutdown of a registered facility, the facility owner or 

operator must submit a written request to the department to discontinue the registration. 

(b) Application Content. A permit application involving ERCs must include the following information: 

(1) The signature of a responsible official or other representative authorized to act on behalf of the 

facility with respect to the ERCs. 

(2) A complete "Emission Reduction Credit Quantification Form" with supporting documentation 

establishing that the emission reduction is surplus, quantifiable, permanent and enforceable: 

(i) Surplus. The applicant must demonstrate to the satisfaction of the department that the 

emission reduction for an emission source is in excess of any reduction required by RACT or MACT 

or any other regulations applicable to the emission source during the baseline period for the emission 

reduction. The determination of "surplus" is as follows: 
Page 98 of 124 

(‘a’) For an emission reduction which physically occurred prior to the state or federal 

register publication date proposing RACT or MACT requirements, the applicant is eligible 

for the full amount of the reduction. Otherwise, the applicant is eligible only for the baseline 

actual emissions reflecting RACT or MACT emission limits. 

(‘b’) For a future reduction as defined in this Part, if the date of approval of the ERC 

is prior to the state or federal register publication date proposing RACT or MACT 

requirements, then the applicant is eligible for the full amount of the reduction. Otherwise, 

the applicant is eligible only for the baseline actual emissions reflecting RACT or MACT 

emission limits. 

(ii) Quantifiable. The applicant must use a reliable basis for quantifying the reduction. 

Continuous emissions monitoring (CEM) data or stack test data approved by the department must be 

used if the facility is required to generate such data. Emission statements, EPA's AP-42 emission 

factors, and fuel and solvent purchase records, with department approval, are acceptable bases for 

quantifying baseline actual emissions if an applicant demonstrates to the department’s satisfaction 

that CEM or stack test data are not available and that CEM or stack test data was not a permit 

requirement. 

(iii) Permanent. The applicant must demonstrate to the satisfaction of the department that all 

emission reductions will be permanent. 

(iv) Enforceable. 
Page 99 of 124 

 (‘a’) For a facility which submits a written request to the department to discontinue its 

 permit or registration (facility shutdown) pursuant to this section, no further action is 

 required. 

 (‘b’) For an emission source shutdown where the facility will continue to operate, the 

 applicant must apply for and obtain a permit modification in accordance with this section 

 which reflects the permanent shutdown of the emission source through a permit condition 

 prohibiting operation of the emission source, or physically removes the emission source from 

 the permit. As to emission sources which will continue to operate at the facility, the 

applicant must submit for department approval a monitoring, recordkeeping, and reporting 

strategy that will be used to demonstrate that the emission reductions are verifiable. If approvable, 

the department will include terms and conditions in the operating permit which implement the 

 applicant’s strategy. If the department determines the strategy is incomplete or otherwise not 

 approvable, the department may propose terms and conditions for the permit or as part of 

 proposed single source SIP revision as appropriate to ensure that the emission reductions are 

 verifiable. 

 (‘c’) Any permit modification must be processed in accordance with Subpart 231-10 

 of this Part. 

231-10.4 Permit application processing. 

(a) Any permit modification, discontinuance of the permit or proposed SIP revision establishing an ERC will 

be processed in accordance with Parts 621 and 201 of this Title and subject to a 30 day public comment period. The 

department will publish notice of such application in the Environmental Notice Bulletin and the applicant must 
Page 100 of 124 

publish notice in a local newspaper. 

(b) Upon approval of a permit application for a proposed new or modified facility which lists ERC sources 

for use as emission offsets, the department will publish notice of the source of ERCs with the draft permit. If the 

source of ERCs changes or is approved after the draft permit has been noticed, the department will publish a 

supplemental notice of the source of the ERCs prior to the final permit issuance. 

(c) The department may deny an application for ERCs if sufficient supporting documentation as required by 

this section is not submitted or provided upon request. 

231-10.5 Permit requirements. 

 This section applies to facilities which create ERCs from emission reductions other than a facility shutdown. 

 In addition to the other requirements of this Part and Parts 201 and 621 of this Title, a permit establishing ERCs 

must include such emission limitations, monitoring, recordkeeping, and reporting conditions as are necessary to 

demonstrate that the emission reductions are verifiable and enforceable. Such emission limitations may include a 

reduction in the hours of operation, limitations on fuel usage, reformulations, installation of control equipment, 

and/or the making of process changes. 

231-10.6 ERC registry. 

(a) All approved ERCs that may be used as emission offsets will be entered into a listing of available ERCs 

(designated the ERC Registry) maintained by the department after the department has approved the ERC application 

in accordance with the procedures in this Part. In the case of a single source SIP revision, the ERCs will be entered 

into the registry after EPA has approved the SIP revision. The registry may be obtained from the department upon 

request. 
Page 101 of 124 

(b) ERC transfers. The authorized representative or a responsible official of the transferor (seller) must 

submit a AUse of Emission Reduction Credits@ form to the department specifying the terms of the transfer. If the 

department determines that the proposed ERC transfer is approvable, the department will note the transfer of ERCs 

on the registry. 

231-10.7 Mobile source and demand side management ERCs. 

 Applications for mobile sources and Demand Side Management ERCs will be approved by the department 

on a case-by-case basis upon submittal of acceptable protocols. The department will prepare a SIP revision 

approval letter which sets for the appropriate enforceable terms and conditions pursuant to which the ERCs are 

being approved and submit the package as a single source SIP revision to EPA for approval following public notice 

of the ERCs. Upon approval of the SIP revision by EPA, the department will publish the ERCs in the ERC 

Registry. 

231-10.8 Replacement and relocation of emission sources. 

(a) ERCs for the replacement of an emission source with new similar equipment (connected to the existing 

stack or a new stack) must be quantified as the difference between: 

(1) the baseline actual emissions of the emission source representing the old emission source, and 

(2) the future potential to emit of the new emission source. 

(b) The relocation of an emission source within the same facility would neither qualify for ERCs for the 

shutdown of the emission source nor be subject to this Subpart at the new location. However, the relocation must 

comply with all other applicable Parts of this Title and result in acceptable air quality impacts pursuant to Section 
Page 102 of 124 

200.6 of Part 200 of this Title. 

231-11 Permit and Reasonable Possibility Requirements 

Section 

231-11.1 Permit requirements for new major facilities, NSR major modifications, and netting 

231-11.2 Reasonable Possibility requirements for insignificant modifications 

231-11.1 Permit requirements for new major facilities, NSR major modifications, and netting. 

 (a) Permit application requirements. In addition to the application requirements under Part 201 of this Title 

the following information must be included in the permit application for any new major facility, NSR major 

modification, or facility netting out of applicability, required to obtain a permit pursuant to this Part: 

 (1) Project description, location, design capacity, and typical operating schedule, including 

 specifications and drawings showing its design and the plant layout, as applicable. 

 (2) A detailed schedule for construction, as applicable. 

 (3) Applicable calculations and supporting documentation of potential-to-emit for a new facility, and 

 baseline actual emissions, projected actual emissions or potential-to-emit as applicable, project emission 

 potential and net emissions increase determination for a modified facility. The information submitted must 

 be sufficiently detailed to allow the department to verify the emissions calculation(s) and to determine the 

 applicability status of the source with respect to this Part. If the calculation of projected actual emissions 

 excludes emissions which an existing emission source could have accommodated during the consecutive 

 24-month period used to establish the baseline actual emissions and that are also unrelated to the particular 

 project, detailed documentation of the calculation of the excluded emissions must be provided at the time of 
Page 103 of 124 

 permit application in order for the exclusion of those emissions to be allowed in determining future 

 compliance. 

 (4) Proposed emission monitoring, recordkeeping and reporting provisions to establish compliance 

 with the applicable requirements of this Part. 

(b) General permit conditions and terms of issuance. Any new major facility, NSR major modification or 

facility netting out of applicability subject to this Part must comply with the requirements of 6 NYCRR Part 201-

6.5(a) of this Title and the following: 

 (1) Within 30 days of commencement of construction, the applicant must notify the department in 

 writing that construction has begun. 

 (2) The filing of a request by the permittee for a permit modification or renewal, or of a notification 

 by the permittee of planned changes or anticipated noncompliance does not authorize the permittee to 

 undertake any action without department approval. The permittee shall not begin actual construction or 

 operate a new or modified facility without department approval in accordance with this Chapter. Operation 

 in a manner other than authorized by a permit shall be grounds for enforcement. 

(c) Permit conditions for monitoring. Any permit issued in accordance with this Part must include the 

monitoring provisions required in Subdivision 201-6.5(b) of this Title. 

(d) Permit conditions for recordkeeping and reporting of compliance monitoring. Any permit issued in 

accordance with this Part must include the recordkeeping and reporting of compliance monitoring provisions 
Page 104 of 124 

required in Subdivision 201-6.5(c) of this Title. 

(e) Compliance certification. Any permit issued in accordance with this Part must include the compliance 

certification provisions required in Subdivision 201-6.5(e) of this Title and, if applicable, submission of 

documentation that the actual measured emissions less those attributed to independent factors such as demand 

growth are below the permitted projected actual emissions limit. 

231-11.2 Reasonable Possibility requirements for insignificant modifications. 

 (a) The requirements of this section do not apply if potential-to-emit is used in lieu of projected actual 

emissions in determining the project emission potential for a proposed modification. 

 

 (b) For a modification with a project emission potential which is less than 50 percent of the applicable 

significant project threshold in Table 3, Table 4 or Table 6 of Subpart 231-13 of this Part, or for a modification with 

a project emission potential which when added to emissions excluded in accordance with Clause 231-

4.1(b)(40)(i)(c) of this Part is less than 50 percent of the applicable significant project threshold in Table 3, Table 4 

or Table 6 of Subpart 231-13 of this Part, the facility owner or operator, in addition to complying with any 

requirements under Part 201 of this Title, must maintain the following information for a minimum of five years: 

 (1) A description of the modification. 

 (2) An identification of each new or modified emission source(s) including the associated processes 

 and emission unit. 

 (3) The calculation of the project emission potential for each modified emission source(s) including 

 supporting documentation. 
Page 105 of 124 

 (4) The date the modification commenced operation. 

 These recordkeeping requirements apply to exempt and trivial activities but do not affect their exempt or 

trivial permitting status under Subpart 201-3 of this Title. 

 (c) For a modification with a project emission potential which is less than 50 percent of the applicable 

significant project threshold in Table 3, Table 4 or Table 6 of Subpart 231-13 of this Part, but equals or exceeds 50 

percent of the applicable significant project threshold when emissions excluded in accordance with Clause 231-

4.1(b)(40)(i)(c) of this Part are added, or for a modification with a project emission potential which equals or 

exceeds 50 percent of the applicable significant project threshold in Table 3, Table 4 or Table 6 of Subpart 231-13 

of this Part, the facility owner or operator must submit an application to modify the facility permit under the minor 

permit provisions of Subpart 201-6 of this Title or obtain a preconstruction permit under the provisions of Subpart 

201-6 of this Title, and must: 

 (1) maintain the following information for a minimum of five years: 

 (i) a description of the modification. 

 (ii) an identification of each new or modified emission source(s) including the associated 

 processes and emission unit. 

 (iii) the calculation of the project emission potential for each modified emission source(s) 

 including supporting documentation. 
Page 106 of 124 

 (iv) the date the modification commenced operation. 

 (2) monitor the emissions of each regulated NSR contaminant from the emission source(s) that will 

 increase as a result of the modification, and calculate and maintain a record of the annual emissions, in tons 

 per year on a calendar year basis, for a period of five years following resumption of regular operations after 

 the modification, or for a period of 10 years following resumption of regular operations after the change if 

 the modification increases the design capacity of or potential to emit the regulated NSR contaminant at such 

 emission source(s). 

 (3) submit a report to the department within 30 days after the end of each year during which records 

 must be generated in accordance with Paragraph 231-11.2(c)(2) of this Part. The report must contain: 

 (i) the name, address, and telephone number of the major facility. 

 (ii) the annual emissions as calculated pursuant to Paragraph (c)(2) of this Section. 

 (iii) a comparison of actual annual emissions to the projected actual emissions and, if 

 applicable, an explanation as to why the actual annual emissions exceeded the projected actual 

 emissions. 

Subpart 231-12 Ambient Air Quality Impact Analysis 

 This Subpart sets forth the procedures and requirements for the performance of an air quality impact analysis 

to determine whether a new or modified facility complies with quantified air quality levels, including air quality 
Page 107 of 124 

standards, PSD increments and monitoring deminimis levels, Air Quality Related Values, and Significant Impact 

Levels. 

 Section 

 231-12.1 Applicability 

231-12.2 Modeling analysis methodologies 

231-12.3 Pre-application analysis for Subparts 231-7 and 231-8 

231-12.4 Exemption and waiver from on-site (i.e. site specific) air quality monitoring 

231-12.5 Post construction monitoring 

231-12.6 Significant impact levels in nonattainment areas 

231-12.7 Significant impact levels for facilities located in attainment areas 

231-12.8 Federal Class I area significant impact levels 

231-12.1 Applicability. 

(a) The following provisions apply to all new facilities or modifications required to evaluate impact on the 

surrounding areas and the public including, but not limited to ambient and sensitive receptors, public health impacts, 

nonattainment areas, and Federal Class I areas. 

(b) The impact analysis procedures are also appropriate for conducting any required air quality related 

environmental impact assessments in conjunction with the permit application for the proposed new or modified 

facility. 

231-12.2 Modeling analysis methodologies. 

(a) The ambient impact analysis must follow the procedures in the applicable guidelines at 40 CFR Part 51, 
Page 108 of 124 

Appendix W: Guideline on Air Quality Models of the EPA and the NYSDEC Guidelines on Dispersion Modeling 

Procedures For Air Quality Impact Analysis available from the department. 

(b) Where an air quality model specified in appendix W of 40 CFR Part 51 is deemed 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 program. Written approval from the 

department must be obtained for any modification or substitution. In addition, use of a modified or substituted 

model shall be subject to public notice and opportunity for public comment, with the determination of a complete 

permit application, in accordance with Parts 201 and 621 of this Title. 

(c) For the purposes of Subparts 231-7 and 231-8 of this Part, the owner or operator of the proposed new or 

modified facility must demonstrate that allowable emission increases from the proposed facility or modification, in 

conjunction with all other applicable emissions increases or reductions (including secondary emissions) would not, 

at a minimum, cause or contribute to air pollution in violation of: 

(1) any national ambient air quality standard in any air quality control region; and 

(2) any applicable maximum allowable PSD increment increase over the baseline concentration in 

any area, as defined in the following Table: 

 
Page 109 of 124 

Contaminant Maximum allowable increase 

(micrograms per cubic meter) 

Federal Class I 

Particulate matter: 

PM-10, annual arithmetic mean . . . . . . . . . . . . . . . . . . . 4 

PM-10, 24-hr maximum . . . . . . . . . . . . . . . . . . . . . . . . 8 

Sulfur dioxide: 

Annual arithmetic mean . . . . . . . . . . . . . . . . . . . . . . . . 2 

24-hr maximum . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 

3-hr maximum . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 

Nitrogen dioxide 

Annual arithmetic mean . . . . . . . . . . . . . . . . . . . . . . . . . 2.5 

Class II 

Particulate matter: 

PM-10, annual arithmetic mean . . . . . . . . . . . . . . . . . . . . 17 

PM-10, 24-hr maximum . . . . . . . . . . . . . . . . . . . . . . . . . 30 

Sulfur dioxide: 

Annual arithmetic mean . . . . . . . . . . . . . . . . . . . . . . . . . 20 

24-hr maximum . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91 
Page 110 of 124 

3-hr maximum . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 512 

Nitrogen dioxide 

Annual arithmetic mean . . . . . . . . . . . . . . . . . . . . . . . . . 25 

Class III 

Particulate matter: 

PM-10, annual arithmetic mean . . . . . . . . . . . . . . . . . . . . 34 

PM-10, 24-hr maximum . . . . . . . . . . . . . . . . . . . . . . . . . 60 

Sulfur dioxide: 

Annual arithmetic mean . . . . . . . . . . . . . . . . . . . . . . . . . 40 

24-hr maximum . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 182 

3-hr maximum . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 700 

Nitrogen dioxide 

Annual arithmetic mean . . . . . . . . . . . . . . . . . . . . . . . . . 50 

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. 

(3) Quantified Air Quality Related Values (AQRVs) including visibility for the applicable Federal 

Class I areas. 

(d) The emission rates for any existing emission sources to be used for the analysis of increment increases in 

Paragraph (c)(2) of this Section can be based on representative actual emissions instead of the allowable emission 
Page 111 of 124 

rates, provided the maximum actual rates under representative normal operations are used for short term increments. 

 Any increment expansions analysis for the purposes of Paragraph (c)(2) of this Section must use representative 

actual short term and annual emissions instead of the allowable emissions. 

(e) For the purposes of Subparts 231-5 and 231-6 of this Part, the owner or operator of the proposed new or 

modified facility must demonstrate that allowable emission increases from the proposed new or modified facility 

would not, at a minimum, cause or contribute to air pollution in violation of any national ambient air quality 

standard in any non-attainment area in accord with Section 231-12.6 of this Part significance levels. 

(f) For the purposes of the required net air quality benefit analysis of Subparts 231-5 and 231-6 of this Part, 

the owner or operator of the proposed new or modified facility must use the allowable emission increases from the 

proposed new or modified facility. For the impact offsetting sources, this analysis must use representative actual 

short term and annual emissions corresponding to the averaging times of the standards. The modeling methods for 

conducting the net air quality benefit analyses are provided in department guidelines on air quality impact analysis. 

231-12.3 Pre-application analysis for Subparts 231-7 and 231-8. 

(a) Prior to submitting an application for a permit in accordance with Subpart 231-7 and Subpart 231-8 of 

this Part, the applicant must provide an analysis of air quality data in the area that the proposed new or modified 

facility would affect for each of the following regulated NSR contaminants: 

(1) For the new facility, each regulated NSR contaminant that would have the potential to emit in an 

amount equal to or greater than the applicable significant project threshold in Table 6 of Subpart 231-13 of 

this Part. 
Page 112 of 124 

(2) For the modified facility, each regulated NSR contaminant that would result in a significant net 

emissions increase. 

(b) With respect to any such regulated NSR contaminant from the list of applicable regulated NSR 

contaminants in Section 231-12.4 of this Part for which no NAAQS exists, the analysis must contain such air quality 

monitoring data as the department determines is necessary to assess ambient air quality for that regulated NSR 

contaminant in any attainment area that the emissions of the source would affect. 

(c) With respect to any such regulated NSR contaminant for which a NAAQS does exist, the analysis must 

contain continuous air quality monitoring data gathered for purposes of determining whether emissions of that 

regulated NSR contaminant would cause or contribute to a violation of the standard or any maximum allowable 

increase in Paragraph 231-12.2(c)(2) of this Part. 

(d) In general, the continuous air quality monitoring data that is required must have been gathered over a 

period of at least one year and must represent at least the year preceding receipt of the application, except that, if the 

department determines that a complete and adequate analysis can be accomplished with monitoring data gathered 

over a period shorter than one year, but not less than four months. 

(e) The owner or operator of a proposed new or modified facility involving the emissions of VOC who 

satisfies all other conditions of Subparts 231-7 and 231-8 of this Part may, when authorized by the department, 

provide post-approval monitoring data for ozone in lieu of providing preconstruction monitoring data. 

(f) Operations of monitoring stations. The owner or operator of a new or modified facility must meet the 

requirements of Appendix B to 40 CFR Part 58 and the NYSDEC Policy, Oversight of Private Air Monitoring 
Page 113 of 124 

 

Networks, available from the department, during the operation of monitoring stations for purposes of satisfying 

applicable provisions of this Subpart. 

231-12.4 Exemption and waiver from onsite (‘i.e.’ site specific) air quality monitoring. 

(a) The department may exempt a proposed new or modified facility from the requirements of Section 231-

12.3 of this Part with respect to monitoring for a particular regulated NSR contaminant, if: 

(1) the emissions increase of the regulated NSR contaminant from the proposed new or modified 

facility would cause, in any attainment area, air quality impacts less than the following deminimis 

monitoring levels: 

Carbon monoxide- - - - - - - - - - - - - 575 μg/m3, 8-hour average; 

Nitrogen dioxide - - - - - - - - - - - - - - 14 μg/m3, annual average; 

Particulate matter (PM-10)- - - - - - - - 10 μg/m3, 24-hr average; 

Sulfur dioxide - - - - - - - - - - - - - - - - 13 μg/m3, 24-hour average; 

Ozone (1

) - - - - - - - - - - - - - - - - - - - - see footnote 

Elemental Lead - - - - - - - - - - - - - - - - 0.1 μg/m3, 3-month average; 

Fluorides - - - - - - - - - - - - - - - - - - - - 0.25 μg/m3, 24-hour average; 

Total and reduced sulfur - - - - - - - - - 10 μg/m3, 1-hour average; 

Hydrogen sulfide - - - - - - - - - - - - - - - 0.2 μg/m3, 1-hour average; 

 or 

1 No deminimis air quality level is provided for ozone. However, any net increase of 100 tons 

per year or more of NOx or volatile organic compounds subject to Subpart 231-7 or Subpart 231-8 

may be required to gather ambient air quality data according to the provisions of Section 231-12.3.
Page 114 of 124 

(2) the concentrations of the regulated NSR contaminant in the area that the facility would affect are 

less than the concentrations listed in Paragraph (1) of this Subdivision. 

(b) In cases where the source impacts are above the deminimis monitoring levels of Subpart 231-12.4(a)(1) 

of this Part, the department may waive the requirements of Section 231-12.3 of this Part with respect to monitoring 

for a particular regulated NSR contaminant for which an applicant makes an acceptable showing that representative 

existing ambient monitoring data exists in the effected area of the quality and nature which demonstrates the current 

conditions of the air quality of the area. 

231-12.5 Post-construction monitoring. 

 The owner or operator of a new or modified facility may be required, after construction of the facility or 

modification, to conduct such ambient monitoring as the department determines is necessary to determine the effect 

of the emissions from the new or modified facility on air quality in any area. 

231-12.6 Significant impact levels in nonattainment areas. 

 For the purposes of Subparts 231-5 and 231-6 of this Part, a new or modified facility will be considered to 

cause or contribute to a violation of a national ambient air quality standard when such new or modified facility 

would, at a minimum, exceed the following significant impact levels (SILs) at any locality that does not or would 

not meet the applicable national standard: 
Page 115 of 124 

Regulated NSR Short Term Averaging Times (hours) 

Contaminant 

Annual 

Average 24 8 3 1 

SO2 1.0 μg/m3 5 μg/m3 25 μg/m3 

PM-10 1.0 μg/m3 5 μg/m3 

NOx 1.0 μg/m3 

CO 500 μg/m3 2000 μg/m3 

231-12.7 Significant impact levels for facilities located in attainment areas. 

 For the purposes of an impact analysis in support of provisions of Subparts 231-7 and 231-8 of this Part, the 

Significant Impact Levels defined in Section 231-12.6 of this Part will serve to determine whether a new or 

modified source will have a significant air quality impact or a contribution to potential standards violation or PSD 

increment exceedances in both the attainment area of the proposed project and in any adjacent non-attainment areas. 

 A showing that the maximum impacts from the proposed new or modified facility for any regulated NSR 

contaminant are below these Significant Impact Levels will be deemed adequate as the required impact analysis to 

demonstrate that the source will not contribute to a standards violation or PSD increment exceedance for that 

regulated NSR contaminant. However, such a demonstration will not exclude the performance of any other required 

impact analysis to satisfy other applicable provisions of Subparts 231-5 to 231-8 of this Part, including the modeling 

for Air Quality Related Values in Federal Class I areas. 

231-12.8 Federal Class I significant impact levels. 

 For the purposes of the PSD increment impact analysis in support of provisions of Subparts 231-7 and 231-8 

of this Part, the following Significant Impact Levels will be used to determine whether a new or modified facility 

will have a significant air quality impact in Federal Class I areas: 
Page 116 of 124 

Regulated NSR 

Contaminant 

Annual Average 24 hour Average 3 Hour Average 

Sulfur Dioxide 0.1 μg/m3 0.2 μg/m3 1.0 μg/m3 

Nitrogen Dioxide 0.1 μg/m3 Not applicable Not Applicable 

PM-10 0.2 μg/m3 0.3 μg/m3 Not applicable 

CO Not applicable Not applicable Not applicable 

A showing that the maximum impacts from the proposed new or modified facility for any regulated NSR 

contaminant are below these Significant Impact Levels will be deemed adequate as the required impact analysis to 

demonstrate that the source will not contribute to a PSD increment exceedance for that regulated NSR contaminant. 

 However, such a demonstration will not exclude the performance of any other required impact analysis to satisfy 

other applicable provisions of Subparts 231-7 to 231-10 of this Part, including the modeling for Air Quality Related 

Values in Federal Class I areas. 

Subpart 231-13 Tables and Emission Thresholds. 

Section 

 231-13.1 Table 1 - Major facility thresholds and offset ratios – Ozone nonattainment areas and the 

 ozone transport region. 

231-13.2 Table 2 - Major facility thresholds and offset ratios for PM nonattainment areas 

 231-13.3 Table 3 - Significant project thresholds, significant net emissions increase thresholds, and 

offset ratios for ozone nonattainment areas and the ozone transport region 

231-13.4 Table 4 - Significant project thresholds, significant net emission increase thresholds, and 

offset ratios for PM nonattainment areas 

231-13.5 Table 5 - Major facility thresholds for attainment and unclassified areas 
Page 117 of 124 

231-13.6 Table 6 - Significant project thresholds and significant net emission increase thresholds for 

attainment and unclassified areas 

231-13.7 Table 7 - Federal Class I variance maximum allowable increase concentrations 

231-13.8 Table 8 - Maximum allowable increase in SO2 concentrations for Gubernatorial variances 

231-13.9 Table 9 - Source category list 

231-13.1 - Table 1 - Major facility thresholds and offset ratios for Ozone nonattainment areas and the ozone 

transport region 

Area/Contaminant Classification Major Facility Threshold 

(tons per year)1

Offset Ratio 

Marginal, Moderate, or Ozone Transport Region 

 VOC 50 At least 1.15:1 

 NOx 100 At least 1.15:1 

Severe 

 VOC 25 At least 1.3:1 

 NOx 25 At least 1.3:1 

1

 - tons per year (tpy) 

231-13.2 - Table 2 - Major facility thresholds and offset ratios for PM nonattainment areas 

Area/Contaminant Classification Major Facility Threshold 

(tpy)1

Offset Ratio 

Moderate 
Page 118 of 124 

 PM-10 100 At least 1:1 

No classification 

 PM-2.5 100 At least 1:1 

1

 - condensible emissions are to be included. 

231-13.3 - Table 3 - Significant project thresholds, significant net emission increase thresholds, and offset ratios 

for ozone nonattainment areas and the ozone transport region 

Area/Contaminant Classification Significant 

Project 

Threshold 

(tpy)1

Significant 

Net Emission 

Increase 

Threshold 

(tpy) 

Offset Ratio 

Marginal, Moderate, or Ozone Transport Region 

 VOC 40 40 At least 1.15:1 

 NOx 40 40 At least 1.15:1 

Severe 

 VOC 2.5 > 25 At least 1.3:1 

 NOx 2.5 > 25 At least 1.3:1 

1

 – project emission potential threshold. 

231-13.4 - Table 4 - Significant project thresholds, significant net emission increase thresholds, and offset ratios 

for PM nonattainment areas 

Area/Contaminant 

Classification 

Significant Project 

Threshold (tpy)1,2

Significant Net 

Emission Increase 

Offset Ratio 
Page 119 of 124 

Threshold (tpy)1

Moderate 

 PM-10 15 15 At least 1:1 

No classification 

 PM-2.5 10 10 At least 1:1 

1

 - condensible emissions are to be included. 

2

 - project emission potential threshold. 

231-13.5 - Table 5 - Major facility thresholds for attainment and unclassified areas 

Contaminant Major Facility Threshold 

(tpy) 

Carbon monoxide 1001 / 250 

Nitrogen oxides 100 / 250 

Sulfur dioxide 100 / 250 

Particulate matter 100 / 250 

Particulate matter: PM-10 emissions2 100 / 250 

Particulate matter: PM-2.5 emissions2 100 / 250 

Ozone: as volatile organic compounds 100 / 250 

Lead (elemental) 100 / 250 

Fluorides 100 / 250 

Sulfuric acid mist 100 / 250 

Hydrogen sulfide (H2S) 100 / 250 

Total reduced sulfur (including H2S) 100 / 250 
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Reduced sulfur compounds (including H2S) 100 / 250 

Municipal waste combustor organics (measured as total tetra 

through octa-chlorinated dibenzo-p-dioxins and dibenzofurans) 

100 / 250 

Municipal waste combustor metals (measured as particulate 

matter) 

100 / 250 

Municipal waste combustor acid gases (measured as sulfur 

dioxide and hydrogen chloride) 

100 / 250 

Municipal solid waste landfills emissions (measured as 

nonmethane organic compounds) 

100 / 250 

Any other regulated NSR contaminant 100 / 250 

1

 - 100 tpy threshold applies if the facility is one of the source categories listed in Section 231-13.9, Table 9 

2

 - condensible emissions are to be included. 

Part 231-13.6 - Table 6 - Significant project thresholds and significant net emission increase thresholds for 

attainment and unclassified areas 

Contaminant Significant Project Threshold 1/ 

Significant Net Emission 

Increase Threshold 

Carbon monoxide 100 tpy 

Nitrogen oxides 40 tpy 

Sulfur dioxide 40 tpy 

Particulate matter 25 tpy 

Particulate matter: PM-10 emissions2 15 tpy 
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Particulate matter: PM-2.5 emissions2 10 tpy 

Ozone: as VOCs or NOx 40 tpy 

Lead (elemental) 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-dioxin and 

dibenzofurans) 

3.2 x 10-6 megagrams per year 

(3.5 x 10-6 tpy) 

Municipal waste combustor metals (measured as particulate 

matter) 

14 megagrams per year (15 tpy) 

Municipal waste combustor acid gases (measured as sulfur 

dioxide and hydrogen chloride) 

36 megagrams per year (40 tpy) 

Municipal solid waste landfills emissions (measured as 

nonmethane organic compounds) 

45 megagrams per year (50 tpy) 

CFC=s 11, 12, 113, 114, 115 Any increase 

Halons 1211, 1301, 2402 Any increase 

Any other regulated NSR contaminant Any increase 

1

 – project emission potential threshold. 

2

 - condensible emissions are to be included. 

231-13.7 - Table 7 - Federal Class I variance maximum allowable increase concentrations 
Page 122 of 124 

Contaminant Maximum allowable increase 

(micrograms per cubic meter) 

Particulate Matter: 

 PM-10, annual arithmetic mean 17 

 PM-10, 24-hr maximum 30 

Sulfur dioxide: 

 Annual arithmetic mean 20 

 24-hr maximum 91 

 3-hr maximum 325 

Nitrogen dioxide: 

 Annual arithmetic mean 25 

1

 – condensible emissions are to be included. 

231-13.8 - Table 8 - Maximum allowable increase in SO2 concentrations for Gubernatorial variances 

Maximum Allowable Increase 

(Micrograms per cubic meter) 

Period of exposure Terrain areas 

Below 900 ft At or Above 900 ft 

24-hr maximum 36 62 

3-hr maximum 130 221 

231-13.9 Table 9 – Source category list. 

(1) coal cleaning plants (with thermal dryers); 
Page 123 of 124 

(2) kraft pulp mills; 

(3) portland cement plants; 

(4) primary zinc smelters; 

(5) iron and steel mills; 

(6) primary aluminum ore reduction plants; 

(7) primary copper smelters; 

(8) municipal incinerators capable of charging more than 50 tons of refuse per day; 

(9) hydrofluoric, sulfuric, or nitric acid plants; 

(10) petroleum refineries; 

(11) lime plants; 

(12) phosphate rock processing plants; 

(13) coke oven batteries; 

(14) sulfur recovery plants; 

(15) carbon black plants (furnace process); 

(16) primary lead smelters; 

(17) fuel conversion plants; 

(18) sintering plants; 

(19) secondary metal production plants; 

(20) chemical process plants (excluding ethanol production facilities that produce ethanol by natural 

fermentation included in NAICS codes 325193 or 312140); 

(21) fossil-fuel boilers (or combination thereof) totaling more than 250 million British thermal units per 

hour heat input; 

(22) petroleum storage and transfer units with a total storage capacity exceeding 300,000 barrels; 

(23) taconite ore processing plants; 
Page 124 of 124 

(24) glass fiber processing plants; 

(25) charcoal production plants; 

(26) fossil-fuel-fired steam electric plants of more than 250 million British thermal units per hour heat 

input; or 

(27) all other source categories regulated by a standard under section 111, for which EPA has completed a 

rule making proceeding under section 302(j) of the act or section 112 of the Act, but only with respect to 

those air contaminants that have been regulated for that category as of the effective date of this Part.