§63.50 Applicability.

(a) General applicability. (1) The requirements of 

this section through §63.56 implement section 112(j) of the 

Clean Air Act (as amended in 1990). The requirements of 

this section through §63.56 apply in each State beginning 

on the effective date of an approved title V permit program 

in such State. The requirements of this section through 

§63.56 do not apply to research or laboratory activities as 

defined in §63.51.

(2) The requirements of this section through §63.56 

apply to:

(i) The owner or operator of affected sources within a 

source category or subcategory under this part that are 

located at a major source that is subject to an approved 

title V permit program and for which there is no section 

112(d) emission standard in place on or after the section 

112(j) deadline. If title V applicability has been 

deferred for a source category, then section 112(j) is not 

applicable for sources in that category within that State, 

local or tribal jurisdiction until those sources become 

subject to title V permitting requirements; and

(ii) Permitting authorities with an approved title V 

permit program.
(b) Relationship to State and local requirements. 

Nothing in §§63.50 through 63.56 shall prevent a State or 

local regulatory agency from imposing more stringent 

requirements, as a matter of State or local law, than those 

contained in §§63.50 through 63.56.

(c) The procedures in §§63.50 through 63.56 apply for 

each affected source only after its section 112(j) deadline 

has passed and there is no generally applicable Federal 

standard governing that source under section 112(d) of the 

Act. If a generally applicable Federal standard governing 

that source is in place, the owner or operator of the 

affected source and the permitting authority are not 

required to take any further action to develop an 

equivalent emission limitation under section 112(j) of the 

Act.

(d) Any final equivalent emission limitation for an 

affected source which is issued by the permitting authority 

pursuant to §§63.50 through 63.56 prior to promulgation of 

a generally applicable Federal standard governing that 

source under section 112(d) of the Act shall be deemed an 

applicable Federal requirement adopted pursuant to section 

112(j) of the Act. Each such equivalent emission 

limitation shall take effect upon issuance of the permit 

containing that limitation under section 112(j)(5) of the 
Act, and shall remain applicable to the source until such 

time as it may be revised or supplanted pursuant to the 

procedures established by §§63.50 through 63.56. Such a 

final equivalent emission limitation, and all associated 

requirements adopted pursuant to §63.52(f)(2), are directly 

enforceable under Federal law regardless of whether or not 

any permit in which they may be contained remains in 

effect.

§63.51 Definitions.

Terms used in §§63.50 through 63.56 that are not 

defined in this section have the meaning given to them in 

the Act, or in subpart A of this part.

Affected source means the collection of equipment, 

activities, or both within a single contiguous area and 

under common control that is in a listed source category or 

subcategory for which there is no section 112(d) emission 

standard on or after the section 112(j) deadline, and that 

is addressed by an applicable MACT emission limitation 

established pursuant to this subpart.

Available information means, for purposes of 

conducting a MACT floor finding and identifying control 

technology options under this subpart, any information that 

is available as of the date on which the first permit 

application under this subpart is filed for a source in the 
relevant source category or subcategory in the State or 

jurisdiction; and, pursuant to the requirements of this 

subpart, is additional relevant information that can be 

expeditiously provided by the Administrator, is submitted 

by the applicant or others prior to or during the public 

comment period on the section 112(j) equivalent emission 

limitation for that source, or information contained in any 

of the information sources in paragraphs (1) through (8) of 

this definition.

(1) A relevant proposed regulation, including all 

supporting information;

(2) Relevant background information documents for a 

draft or proposed regulation;

(3) Any relevant regulation, information or guidance 

collected by the Administrator establishing a MACT floor 

finding and/or MACT determination;

(4) Relevant data and information available from the 

Clean Air Technology Center developed pursuant to section 

112(l)(3) of the Act;

(5) Relevant data and information contained in EPA

databases such as the Air Facility Subsystem;

(6) Any additional information that can be 

expeditiously provided by the Administrator;
(7) Any information provided by applicants in an 

application for a permit, permit modification, 

administrative amendment, or Notice of MACT Approval 

pursuant to the requirements of this subpart; and

(8) Any additional relevant information provided by 

the applicant.

Control technology means measures, processes, methods,

systems, or techniques to limit the emission of hazardous 

air pollutants including, but not limited to, measures 

which:

(1) Reduce the quantity, or eliminate emissions, of 

such pollutants through process changes, substitution of 

materials or other modifications;

(2) Enclose systems or processes to eliminate 

emissions;

(3) Collect, capture, or treat such pollutants when 

released from a process, stack, storage or fugitive 

emissions point;

(4) Are design, equipment, work practice, or 

operational standards (including requirements for operator 

training or certification) as provided in 42 U.S.C. 

7412(h); or

(5) Are a combination of paragraphs (1) through (4) of 

this definition.
Enhanced review means a review process containing all 

administrative steps needed to ensure that the terms and 

conditions resulting from the review process can be 

incorporated using title V permitting procedures.

Equivalent emission limitation means an emission 

limitation, established under section 112(j) of the Act, 

which is equivalent to the MACT standard that EPA would 

have promulgated under section 112(d) of the Act.

Listed source category or subcategory means a source 

category or subcategory initially listed pursuant to 

section 112(c)(1) at 57 FR 31576, 15991 (July 16, 1992).

Maximum achievable control technology (MACT) emission 

limitation for existing sources means the emission 

limitation reflecting the maximum degree of reduction in 

emissions of hazardous air pollutants (including a 

prohibition on such emissions, where achievable) that the 

Administrator, taking into consideration the cost of 

achieving such emission reductions, and any non-air quality 

health and environmental impacts and energy requirements, 

determines is achievable by sources in the category or 

subcategory to which such emission standard applies. This 

limitation shall not be less stringent than the MACT floor.

Maximum achievable control technology (MACT) emission 

limitation for new sources means the emission limitation 
which is not less stringent than the emission limitation 

achieved in practice by the best controlled similar source, 

and which reflects the maximum degree of reduction in 

emissions of hazardous air pollutants (including a 

prohibition on such emissions, where achievable) that the 

Administrator, taking into consideration the cost of 

achieving such emission reduction, and any non-air quality 

health and environmental impacts and energy requirements, 

determines is achievable by sources in the category or 

subcategory to which such emission standard applies.

Maximum Achievable Control Technology (MACT) floor

means:

(1) For existing sources:

(i) The average emission limitation achieved by the 

best performing 12 percent of the existing sources in the 

United States (for which the Administrator has emissions 

information), excluding those sources that have, within 18 

months before the emission standard is proposed or within 

30 months before such standard is promulgated, whichever is 

later, first achieved a level of emission rate or emission 

reduction which complies, or would comply if the source is 

not subject to such standard, with the lowest achievable 

emission rate (as defined in section 171 of the Act) 

applicable to the source category and prevailing at the 
time, in the category or subcategory, for categories and 

subcategories of stationary sources with 30 or more 

sources; or

(ii) The average emission limitation achieved by the 

best performing five sources (for which the Administrator 

has or could reasonably obtain emissions information) in 

the category or subcategory, for categories or 

subcategories with fewer than 30 sources;

(2) For new sources, the emission limitation achieved 

in practice by the best controlled similar source.

New affected source means the collection of equipment, 

activities, or both, that if constructed after the issuance 

of a section 112(j) permit for the source pursuant to 

§63.52, is subject to the applicable MACT emission 

limitation for new sources. Each permit must define the 

term “new affected source,” which will be the same as the 

“affected source” unless a different collection is 

warranted based on consideration of factors including:

(1) Emission reduction impacts of controlling 

individual sources versus groups of sources;

(2) Cost effectiveness of controlling individual 

equipment;

(3) Flexibility to accommodate common control 

strategies;
(4) Cost/benefits of emissions averaging;

(5) Incentives for pollution prevention;

(6) Feasibility and cost of controlling processes that 

share common equipment (e.g., product recovery devices);

(7) Feasibility and cost of monitoring; and

(8) Other relevant factors.

Permitting authority means the permitting authority as 

defined in part 70 of this chapter.

Research or laboratory activities means activities 

whose primary purpose is to conduct research and

development into new processes and products where such 

activities are operated under the close supervision of 

technically trained personnel and are not engaged in the 

manufacture of products for commercial sale in commerce, 

except in a de minimis manner; and where the source is not 

in a source category, specifically addressing research or 

laboratory activities, that is listed pursuant to section 

112(c)(7) of the Act.

Section 112(j) deadline means: 

(1) for a source in the Polyvinyl Chloride and 

Copolymers Production, Brick and Structural Clay Products 

Manufacturing, Clay Ceramics Manufacturing, or the 

Industrial, Commercial and Institutional Boilers and 

Process Heaters source category, the earlier of [THE DATE 
90 DAYS AFTER THE PROMULGATION DATE IN THE FEDERAL 

REGISTER] or the date by which the source’s permitting 

authority has requested in writing a section 112(j) permit 

application containing the information set out in section 

63.53(b); or

(2) for any other major source in a listed source 

category or subcategory, 18 months after the date of a 

court mandate effectuating the complete vacatur of a 

section 112(d) rule applicable to such source.

Similar source means that equipment or collection of 

equipment that, by virtue of its structure, operability, 

type of emissions and volume and concentration of 

emissions, is substantially equivalent to the new affected 

source and employs control technology for control of 

emissions of hazardous air pollutants that is practical for 

use on the new affected source.

Source category schedule for standards means the 

schedule for promulgating MACT standards issued pursuant to 

section 112(e) of the Act.

§63.52 Approval process for new and existing affected 

sources.

(a) Sources subject to section 112(j) as of the 

section 112(j) deadline. The requirements of paragraphs 

(a)(1) of this section apply to major sources that include, 
as of the section 112(j) deadline, one or more sources in a 

category or subcategory for which there is no section 

112(d) emission standard in place on or after the section 

112(j) deadline. Existing source MACT requirements 

(including relevant compliance deadlines), as specified in 

a title V permit issued to the source pursuant to the 

requirements of the subpart, must apply to such sources.

(1) The owner or operator must submit an application 

for a title V permit or for a revision to an existing title 

V permit or a pending title V permit meeting the 

requirements of §63.53(b) by the section 112(j) deadline 

unless the owner or operator has submitted a request for 

112(g) equivalency determination under paragraph (a)(2) of 

this section.

(2) The requirements in paragraphs (a)(2)(i) through (ii) 

of this section apply when the owner or operator has 

obtained a title V permit that incorporates a case-by-case 

MACT determination by the permitting authority under 

section 112(g) or has submitted a title V permit 

application for a revision that incorporates a case-by-case 

MACT determination under section 112(g), but has not 

submitted an application for a title V permit revision that 

addresses the emission limitation requirements of section 

112(j).
(i) When the owner or operator has a title V permit 

that incorporates a case-by-case MACT determination by the 

permitting authority under section 112(g), the owner or 

operator must submit a request meeting the requirements of 

§63.53(a) for a title V permit revision within 30 days of 

the section 112(j) deadline. Using the procedures 

established in paragraph (e) of this section, the 

permitting authority must determine whether the emission 

limitations adopted pursuant to the prior case-by-case MACT 

determination under section 112(g) are substantially as 

effective as the emission limitations which the permitting 

authority would otherwise adopt pursuant to section 112(j) 

for the source in question. If the permitting authority 

determines that the emission limitations previously adopted 

to effectuate section 112(g) are substantially as effective 

as the emission limitations which the permitting authority 

would otherwise adopt to effectuate section 112(j) for the 

source, then the permitting authority must retain the 

existing emission limitations in the permit as the emission 

limitations to effectuate section 112(j). The title V 

permit applicable to that source must be revised 

accordingly. If the permitting authority does not retain 

the existing emission limitations in the permit as the 

emission limitations to effectuate section 112(j), the MACT 
requirements of this subpart are satisfied upon issuance of 

a revised title V permit incorporating any additional 

section 112(j) requirements.

(ii) When the owner or operator has submitted a title 

V permit application that incorporates a case-by-case MACT 

determination by the permitting authority under section 

112(g), but has not received the permit incorporating the 

section 112(g) requirements, the owner or operator must 

continue to pursue a title V permit that addresses the 

emission limitation requirements of section 112(g). Within 

30 days of issuance of that title V permit, the owner or 

operator must submit an application meeting the 

requirements of §63.53(a) for an equivalency determination. 

Using the procedures established in paragraph (e) of this 

section, the permitting authority must determine whether 

the emission limitations adopted pursuant to the prior 

case-by-case MACT determination under section 112(g) are 

substantially as effective as the emission limitations 

which the permitting authority would otherwise adopt 

pursuant to section 112(j) for the source in question. If 

the permitting authority determines that the emission 

limitations previously adopted to effectuate section 112(g) 

are substantially as effective as the emission limitations 

which the permitting authority would otherwise adopt to 
effectuate section 112(j) for the source, then the 

permitting authority must retain the existing emission 

limitations in the permit as the emission limitations to 

effectuate section 112(j). The title V permit applicable 

to that source must be revised accordingly. If the 

permitting authority does not retain the existing emission 

limitations in the permit as the emission limitations to 

effectuate section 112(j), the MACT requirements of this 

subpart are satisfied upon issuance of a revised title V 

permit incorporating any additional section 112(j) 

requirements.

(b) Sources that become subject to section 112(j) after 

the section 112(j) deadline and that do not have a title V 

permit addressing section 112(j) requirements. The 

requirements of paragraphs (b)(1) through (4) of this 

section apply to sources that do not meet the criteria in 

paragraph (a) of this section on the section 112(j) 

deadline and are, therefore, not subject to section 112(j) 

on that date, but where events occur subsequent to the 

section 112(j) deadline that would bring the source under 

the requirements of this subpart, and the source does not 

have a title V permit that addresses the requirements of 

section 112(j).
(1) When one or more sources in a category or 

subcategory subject to the requirements of this subpart are 

installed at a major source, or result in the source 

becoming a major source due to the installation, and the 

installation does not invoke section 112(g) requirements, 

the owner or operator must submit an application meeting 

the requirements of §63.53(b) within 30 days of startup of 

the source. This application shall be reviewed using the 

procedures established in paragraph (e) of this section. 

Existing source MACT requirements (including relevant 

compliance deadlines), as specified in a title V permit 

issued pursuant to the requirements of this subpart, shall 

apply to such sources.

(2) The requirements in this paragraph apply when one 

or more sources in a category or subcategory subject to 

this subpart are installed at a major source, or result in 

the source becoming a major source due to the installation, 

and the installation does require emission limitations to 

be established and permitted under section 112(g), and the 

owner or operator has not submitted an application for a 

title V permit revision that addresses the emission 

limitation requirements of section 112(j). In this case, 

the owner or operator must apply for and obtain a title V 

permit that addresses the emission limitation requirements 
of section 112(g). Within 30 days of issuance of that

title V permit, the owner or operator must submit a request 

meeting the requirements of §63.53(a) for an equivalency 

determination. Using the procedures established in 

paragraph (e) of this section, the permitting authority 

must determine whether the emission limitations adopted 

pursuant to the prior case-by-case MACT determination under 

section 112(g) are substantially as effective as the 

emission limitations which the permitting authority would 

otherwise adopt pursuant to section 112(j) for the source 

in question. If the permitting authority determines that 

the emission limitations previously adopted to effectuate 

section 112(g) are substantially as effective as the 

emission limitations which the permitting authority would 

otherwise adopt to effectuate section 112(j) for the 

source, then the permitting authority must retain the 

existing emission limitations in the permit as the emission 

limitations to effectuate section 112(j). The title V 

permit applicable to that source must be revised 

accordingly. If the permitting authority does not retain 

the existing emission limitations in the permit as the 

emission limitations to effectuate section 112(j), the MACT 

requirements of this subpart are satisfied upon issuance of 
a revised title V permit incorporating any additional 

section 112(j) requirements.

(3) The owner or operator of an area source that, due 

to a relaxation in any federally enforceable emission 

limitation (such as a restriction on hours of operation), 

increases its potential to emit hazardous air pollutants 

such that the source becomes a major source that is subject 

to this subpart, must submit an application meeting the 

requirements of §63.53(b) for a title V permit or for an 

application for a title V permit revision within 30 days 

after the date that such source becomes a major source. 

This application must be reviewed using the procedures 

established in paragraph (e) of this section. Existing 

source MACT requirements (including relevant compliance 

deadlines), as specified in a title V permit issued 

pursuant to the requirements of this subpart, must apply to 

such sources.

(4) On or after April 5, 2002, if the Administrator 

establishes a lesser quantity emission rate under section 

112(a)(1) of the Act that results in an area source 

becoming a major source that is subject to this subpart, 

then the owner or operator of such a major source must 

submit an application meeting the requirements of §63.53(b) 

for a title V permit or for a change to an existing title V 
permit or pending title V permit on or before the date 6 

months after the date that such source becomes a major 

source. Existing source MACT requirements (including 

relevant compliance deadlines), as specified in a title V 

permit issued pursuant to the requirements of this subpart, 

shall apply to such sources.

(c) Sources that have a title V permit addressing 

section 112(j) requirements. The requirements of 

paragraphs (c)(1) and (2) of this section apply to major 

sources within a listed source category or subcategory for 

which there is no section 112(d) emission standard in place 

on or after the section 112(j) deadline, and the owner or 

operator has a permit meeting the section 112(j) 

requirements, and where changes occur at the major source 

to equipment, activities, or both, subsequent to the 

section 112(j) deadline.

(1) If the title V permit already provides the 

appropriate requirements that address the events that occur 

under paragraph (c) of this section subsequent to the 

section 112(j) deadline, then the source must comply with 

the applicable new source MACT or existing source MACT 

requirements as specified in the permit, and the section 

112(j) requirements are thus satisfied.
(2) If the title V permit does not contain the 

appropriate requirements that address the events that occur 

under paragraph (c) of this section subsequent to the 

section 112(j) deadline, then the owner or operator must 

submit an application for a revision to the existing title 

V permit that meets the requirements of §63.53(b). The 

application must be submitted within 30 days of beginning 

construction and must be reviewed using the procedures 

established in paragraph (e) of this section. Existing 

source MACT requirements (including relevant compliance 

deadlines), as specified in a title V permit issued 

pursuant to the requirements of this subpart, shall apply 

to such sources.

(d) Requests for notice of MACT approval. In addition to 

meeting the requirements of paragraphs (a), (b), and (c) of 

this section, the owner or operator of a new affected 

source may submit an application for a Notice of MACT 

Approval before construction, pursuant to §63.54.

(e) Permit application review. (1) Permit applications 

must be reviewed by the permitting authority according to 

procedures established in §63.55. The resulting MACT 

determination must be incorporated into the source's title 

V permit according to procedures established under title V, 
and any other regulations approved under title V in the 

jurisdiction in which the affected source is located.

(2) As specified in paragraphs (a) and (b) of this section, 

an owner or operator who has submitted an application 

meeting the requirements of §63.53(a) may request a 

determination by the permitting authority of whether 

emission limitations adopted pursuant to a prior case-bycase MACT determination under section 112(g) that apply to 

one or more sources at a major source in a relevant 

category or subcategory are substantially as effective as 

the emission limitations which the permitting authority 

would otherwise adopt pursuant to section 112(j) for the 

source in question. Each request for an equivalency 

determination under this paragraph (e)(2) will be construed 

in the alternative as a complete application for an 

equivalent emission limitation under section 112(j). The 

process for determination by the permitting authority of 

whether the emission limitations in the prior case-by-case 

MACT determination are substantially as effective as the 

emission limitations which the permitting authority would 

otherwise adopt under section 112(j) must include the 

opportunity for full public, EPA, and affected State review 

prior to a final determination. If the permitting 

authority determines that the emission limitations in the 
prior case-by-case MACT determination are substantially as 

effective as the emission limitations which the permitting 

authority would otherwise adopt under section 112(j), then 

the permitting authority must adopt the existing emission 

limitations in the permit as the emission limitations to 

effectuate section 112(j) for the source in question. If 

more than 3 years remain on the current title V permit, the 

owner or operator must submit an application for a title V 

permit revision to make any conforming changes in the 

permit required to adopt the existing emission limitations 

as the section 112(j) MACT emission limitations. If less 

than 3 years remain on the current title V permit, any 

required conforming changes must be made when the permit is 

renewed. If the permitting authority determines that the 

emission limitations in the prior case-by-case MACT 

determination under section 112(g) are not substantially as 

effective as the emission limitations which the permitting 

authority would otherwise adopt for the source in question 

under section 112(j), the permitting authority must make a 

new MACT determination and adopt a title V permit 

incorporating an appropriate equivalent emission limitation 

under section 112(j). Such a determination constitutes 

final action for purposes of judicial review under 40 CFR 
70.4(b)(3)(x) and corresponding State title V program 

provisions.

(3) Within 60 days of submittal of the permit

application, the permitting authority must notify the owner 

or operator in writing whether the application is complete 

or incomplete. The permit application shall be deemed 

complete on the date it was submitted unless the permitting 

authority notifies the owner or operator in writing within 

60 days of the submittal that the permit application is 

incomplete. A permit application is complete if it is 

sufficient to begin processing the application for a title 

V permit addressing section 112(j) requirements. In the 

event that the permitting authority disapproves a permit 

application or determines that the application is 

incomplete, the owner or operator must revise and resubmit 

the application to meet the objections of the permitting 

authority. The permitting authority must specify a 

reasonable period in which the owner or operator is 

required to remedy the deficiencies in the disapproved or 

incomplete application. This period may not exceed 6 

months from the date the owner or operator is first 

notified that the application has been disapproved or is 

incomplete.
(4) Following submittal of a permit application, the 

permitting authority may request additional information 

from the owner or operator. The owner or operator must 

respond to such requests in a timely manner.

(5) If the owner or operator has submitted a timely 

and complete application as required by this section, any 

failure to have a title V permit addressing section 112(j) 

requirements shall not be a violation of section 112(j), 

unless the delay in final action is due to the failure of 

the applicant to submit, in a timely manner, information 

required or requested to process the application. Once a 

complete application is submitted, the owner or operator 

shall not be in violation of the requirement to have a 

title V permit addressing section 112(j) requirements.

(f) Permit content. The title V permit must contain an 

equivalent emission limitation (or limitations) for the 

relevant category or subcategory determined on a case-bycase basis by the permitting authority, or, if the 

applicable criteria in subpart D of this part are met, the 

title V permit may contain an alternative emission 

limitation. For the purposes of the preceding sentence, 

early reductions made pursuant to section 112(i)(5)(A) of 

the Act must be achieved not later than the date on which 
the relevant standard should have been promulgated 

according to the source category schedule for standards.

(1) The title V permit must contain an emission 

standard or emission limitation that is equivalent to 

existing source MACT and an emission standard or emission 

limitation that is equivalent to new source MACT for 

control of emissions of hazardous air pollutants. The MACT 

emission standards or limitations must be determined by the 

permitting authority and must be based on the degree of 

emission reductions that can be achieved if the control 

technologies or work practices are installed, maintained, 

and operated properly. The permit must also specify the 

affected source and the new affected source. If 

construction of a new affected source or reconstruction of 

an affected source commences after a title V permit meeting 

the requirements of section 112(j) has been issued for the 

source, the new source MACT compliance dates must apply.

(2) The title V permit must specify any notification, 

operation and maintenance, performance testing, monitoring, 

and reporting and recordkeeping requirements. In developing 

the title V permit, the permitting authority must consider 

and specify the appropriate provisions of subpart A of this 

part. The title V permit must also include the information 

in paragraphs (f)(2)(i) through (iii) of this section.
(i) In addition to the MACT emission limitation 

required by paragraph (f)(1) of this section, additional 

emission limits, production limits, operational limits or 

other terms and conditions necessary to ensure practicable 

enforceability of the MACT emission limitation.

(ii) Compliance certifications, testing, monitoring, 

reporting and recordkeeping requirements that are 

consistent with requirements established pursuant to title 

V and paragraph (h) of this section.

(iii) Compliance dates by which the owner or operator 

must be in compliance with the MACT emission limitation and 

all other applicable terms and conditions of the permit.

(A) The owner or operator of an affected source 

subject to the requirements of this subpart must comply 

with the emission limitation(s) by the date established in 

the source's title V permit. In no case shall such 

compliance date be later than 3 years after the issuance of 

the permit for that source, except where the permitting 

authority issues a permit that grants an additional year to 

comply in accordance with section 112(i)(3)(B) of the Act, 

or unless otherwise specified in section 112(i), or in 

subpart D of this part.

(B) The owner or operator of a new affected source, as 

defined in the title V permit meeting the requirements of 
section 112(j), that is subject to the requirements of this 

subpart must comply with a new source MACT level of control 

immediately upon startup of the new affected source.

(g) Permit issuance dates. The permitting authority 

must issue a title V permit meeting section 112(j) 

requirements within 18 months after submittal of the 

complete permit application.

(h) Enhanced monitoring. In accordance with section 

114(a)(3) of the Act, monitoring shall be capable of 

demonstrating continuous compliance for each compliance 

period during the applicable reporting period. Such 

monitoring data shall be of sufficient quality to be used 

as a basis for directly enforcing all applicable 

requirements established under this subpart, including 

emission limitations.

(i) MACT emission limitations. (1) The owner or 

operator of affected sources subject to paragraphs (a), 

(b), and (c) of this section must comply with all 

requirements of this subpart that are applicable to 

affected sources, including the compliance date for 

affected sources established in paragraph (f)(2)(iii)(A) of 

this section.

(2) The owner or operator of new affected sources 

subject to paragraph (c)(1) of this section must comply 
with all requirements of this subpart that are applicable 

to new affected sources, including the compliance date for 

new affected sources established in paragraph 

(f)(2)(iii)(B) of this section.

§63.53 Section 112(g) equivalency determination requests 

and application content for case-by-case MACT 

determinations.

(a) Section 112(g) equivalency determination request. 

A section 112(g) equivalency determination request must 

contain the information in paragraphs (a)(1) through (4) of 

this section.

(1) The name and address (physical location) of the 

major source.

(2) A brief description of the major source and an 

identification of the relevant source category.

(3) An identification of the types of emission points 

belonging to the relevant source category.

(4) An identification of any affected sources for 

which a section 112(g) MACT determination has been made.

(b) Permit application. (1) In compiling a permit

application, the owner or operator may cross-reference 

specific information in any prior submission by the owner 

or operator to the permitting authority, but in crossreferencing such information the owner or operator may not 
presume favorable action on any prior application or 

request which is still pending. In compiling a permit

application, the owner or operator may also cross-reference 

any part of a standard proposed by the Administrator 

pursuant to section 112(d) of the Act for any category or 

subcategory which includes sources to which the permit

application applies.

(2) The permit application for a MACT determination 

must contain the information in paragraphs (b)(2)(i) 

through (b)(2)(vi) of this section.

(i) The information required by paragraph (a) of this 

section if a request for 112(g) equivalency was not 

previously submitted.

(ii) For a new affected source, the anticipated date 

of startup of operation.

(iii) Each emission point or group of emission points 

at the affected source which is part of a category or 

subcategory for which a permit application is required, and 

each of the hazardous air pollutants emitted at those 

emission points. When the Administrator has proposed a 

standard pursuant to section 112(d) of the Act for a 

category or subcategory, such information may be limited to 

those emission points and hazardous air pollutants which 

would be subject to control under the proposed standard.
(iv) Any existing Federal, State, or local limitations 

or requirements governing emissions of hazardous air 

pollutants from those emission points which are part of a 

category or subcategory for which a permit application is 

required.

(v) For each identified emission point or group of 

affected emission points, an identification of control 

technology in place.

(vi) Any additional emission data or other information 

specifically requested by the permitting authority.

(3) The permit application for a MACT determination 

may, but is not required to, contain the following 

information:

(i) Recommended emission limitations for the affected 

source and support information consistent with §63.52(f). 

The owner or operator may recommend a specific design, 

equipment, work practice, or operational standard, or 

combination thereof, as an emission limitation.

(ii) A description of the control technologies that 

would be applied to meet the emission limitation including 

technical information on the design, operation, size, 

estimated control efficiency and any other information 

deemed appropriate by the permitting authority, and 
identification of the affected sources to which the control 

technologies must be applied.

(iii) Relevant parameters to be monitored and 

frequency of monitoring to demonstrate continuous 

compliance with the MACT emission limitation over the 

applicable reporting period.

§63.54 Preconstruction review procedures for new affected 

sources.

The purpose of this section is to describe alternative 

review processes that the permitting authority may use to 

make a MACT determination for the new affected source.

(a) Review process for new affected sources. (1) If 

the permitting authority requires an owner or operator to 

obtain or revise a title V permit before construction of 

the new affected source, or when the owner or operator 

chooses to obtain or revise a title V permit before 

construction, the owner or operator must follow the 

procedures established under the applicable title V permit 

program before construction of the new affected source.

(2) If an owner or operator is not required to obtain 

or revise a title V permit before construction of the new 

affected source (and has not elected to do so), but the new 

affected source is covered by any preconstruction or 

preoperation review requirements established pursuant to 
section 112(g) of the Act, then the owner or operator must 

comply with those requirements in order to ensure that the 

requirements of section 112(j) and (g) are satisfied. If 

the new affected source is not covered by section 112(g), 

the permitting authority, in its discretion, may issue a 

Notice of MACT Approval, or the equivalent, in accordance 

with the procedures set forth in paragraphs (b) through (f) 

of this section, or an equivalent permit review process, 

before construction or operation of the new affected 

source.

(3) Regardless of the review process, the MACT 

determination shall be consistent with the principles 

established in §63.55. The application for a Notice of MACT 

Approval or a title V permit, permit modification, or 

administrative amendment, whichever is applicable, shall 

include the documentation required by §63.53.

(b) Optional administrative procedures for 

preconstruction or preoperation review for new affected 

sources. The permitting authority may provide for an 

enhanced review of section 112(j) MACT determinations for 

review procedures and compliance requirements equivalent to 

those set forth in paragraphs (b) through (f) of this 

section.
(1) The permitting authority will notify the owner or 

operator in writing as to whether the application for a 

MACT determination is complete or whether additional 

information is required.

(2) The permitting authority will approve an 

applicant's proposed control technology, or the permitting 

authority will notify the owner or operator in writing of 

its intention to disapprove a control technology.

(3) The owner or operator may present in writing, 

within a time frame specified by the permitting authority, 

additional information, considerations, or amendments to 

the application before the permitting authority's issuance 

of a final disapproval.

(4) The permitting authority will issue a preliminary 

approval or issue a disapproval of the application, taking 

into account additional information received from the owner 

or operator.

(5) A determination to disapprove any application will 

be in writing and will specify the grounds on which the 

disapproval is based.

(6) Approval of an applicant's proposed control 

technology must be set forth in a Notice of MACT Approval 

(or the equivalent) as described in §63.52(f).
(c) Opportunity for public comment on Notice of MACT 

Approval. The permitting authority will provide opportunity 

for public comment on the preliminary Notice of MACT 

Approval prior to issuance, including, at a minimum,

(1) Availability for public inspection in at least one 

location in the area affected of the information submitted 

by the owner or operator and of the permitting authority's 

tentative determination;

(2) A period for submittal of public comment of at 

least 30 days; and

(3) A notice by prominent advertisement in the area 

affected of the location of the source information and 

analysis specified in §63.52(f). The form and content of 

the notice must be substantially equivalent to that found 

in §70.7 of this chapter.

(4) An opportunity for a public hearing, if one is 

requested. The permitting authority will give at least 30 

days notice in advance of any hearing.

(d) Review by the EPA and affected States. The 

permitting authority must send copies of the preliminary 

notice (in time for comment) and final notice required by 

paragraph (c) of this section to the Administrator through 

the appropriate Regional Office, and to all other State and 

local air pollution control agencies having jurisdiction in 
affected States. The permitting authority must provide EPA 

with a review period for the final notice of at least 45 

days and shall not issue a final Notice of MACT Approval 

until EPA objections are satisfied.

(e) Compliance with MACT determinations. An owner or 

operator of a major source that is subject to a MACT 

determination must comply with notification, operation and 

maintenance, performance testing, monitoring, reporting, 

and recordkeeping requirements established under §63.52(h), 

under title V, and at the discretion of the permitting 

authority, under subpart A of this part. The permitting 

authority must provide the EPA with the opportunity to 

review compliance requirements for consistency with 

requirements established pursuant to title V during the 

review period under paragraph (d) of this section.

(f) Equivalency under section 112(l). If a permitting 

authority requires preconstruction review for new source 

MACT determinations under this subpart, such requirement 

shall not necessitate a determination under subpart E of 

this part.

§63.55 Maximum achievable control technology (MACT) 

determinations for affected sources subject to case-by-case 

determination of equivalent emission limitations.
(a) Requirements for permitting authorities. The 

permitting authority must determine whether the permit

application is complete or an application for a Notice of 

MACT Approval is approvable. In either case, when the 

application is complete or approvable, the permitting 

authority must establish hazardous air pollutant emissions 

limitations equivalent to the limitations that would apply 

if an emission standard had been issued in a timely manner 

under section 112(d) of the Act. The permitting authority 

must establish these emissions limitations consistent with 

the following requirements and principles:

(1) Emission limitations must be established for the 

equipment and activities within the affected sources within 

a source category or subcategory for which the section 

112(j) deadline has passed.

(2) Each emission limitation for an existing affected 

source must reflect the maximum degree of reduction in 

emissions of hazardous air pollutants (including a 

prohibition on such emissions, where achievable) that the 

permitting authority, taking into consideration the cost of 

achieving such emission reduction and any non-air quality 

health and environmental impacts and energy requirements, 

determines is achievable by affected sources in the 

category or subcategory for which the section 112(j) 
deadline has passed. This limitation must not be less 

stringent than the MACT floor which must be established by 

the permitting authority according to the requirements of 

section 112(d)(3)(A) and (B) and must be based upon 

available information.

(3) Each emission limitation for a new affected source 

must reflect the maximum degree of reduction in emissions 

of hazardous air pollutants (including a prohibition on 

such emissions, where achievable) that the permitting 

authority, taking into consideration the cost of achieving 

such emission reduction and any non-air quality health and 

environmental impacts and energy requirements, determines 

is achievable. This limitation must not be less stringent 

than the emission limitation achieved in practice by the 

best controlled similar source which must be established by 

the permitting authority according to the requirements of 

section 112(d)(3). This limitation must be based upon 

available information.

(4) The permitting authority must select a specific 

design, equipment, work practice, or operational standard, 

or combination thereof, when it is not feasible to 

prescribe or enforce an equivalent emission limitation due 

to the nature of the process or pollutant. It is not 

feasible to prescribe or enforce a limitation when the 
Administrator determines that hazardous air pollutants 

cannot be emitted through a conveyance designed and 

constructed to capture such pollutant, or that any 

requirement for, or use of, such a conveyance would be 

inconsistent with any Federal, State, or local law, or the 

application of measurement methodology to a particular 

class of sources is not practicable due to technological 

and economic limitations.

(5) Nothing in this subpart shall prevent a State or 

local permitting authority from establishing an emission 

limitation more stringent than required by Federal 

regulations.

(b) Reporting to EPA. The owner or operator must 

submit additional copies of its application for a title V 

permit, permit revision, or Notice of MACT Approval, 

whichever is applicable, to the EPA at the same time the 

material is submitted to the permitting authority.

§63.56 Requirements for case-by-case determination of 

equivalent emission limitations after promulgation of 

subsequent MACT standard.

(a) If the Administrator promulgates a relevant 

emission standard that is applicable to one or more 

affected sources within a major source before the date a 

permit application under this paragraph (a) is approved, 
the title V permit must contain the promulgated standard 

rather than the emission limitation determined under 

§63.52, and the owner or operator must comply with the 

promulgated standard by the compliance date in the 

promulgated standard.

(b) If the Administrator promulgates a relevant 

emission standard under section 112(d) of the Act that is 

applicable to a source after the date a permit is issued 

pursuant to §63.52 or §63.54, the permitting authority must 

incorporate requirements of that standard in the title V 

permit upon its next renewal. The permitting authority 

must establish a compliance date in the revised permit that 

assures that the owner or operator must comply with the 

promulgated standard within a reasonable time, but not 

longer than 8 years after such standard is promulgated or 8 

years after the date by which the owner or operator was 

first required to comply with the emission limitation 

established by the permit, whichever is earlier. However, 

in no event shall the period for compliance for existing 

sources be shorter than that provided for existing sources 

in the promulgated standard.

(c) Notwithstanding the requirements of paragraph (a) 

or (b) of this section, the requirements of paragraphs 

(c)(1) and (2) of this section shall apply.
(1) If the Administrator promulgates an emission 

standard under section 112(d) that is applicable to an 

affected source after the date a permit application under 

this paragraph is approved under §63.52 or §63.54, the 

permitting authority is not required to change the emission 

limitation in the permit to reflect the promulgated 

standard if the permitting authority determines that the 

level of control required by the emission limitation in the 

permit is substantially as effective as that required by 

the promulgated standard pursuant to §63.1(e).

(2) If the Administrator promulgates an emission 

standard under section 112(d) of the Act that is applicable 

to an affected source after the date a permit application 

is approved under §63.52 or §63.54, and the level of 

control required by the promulgated standard is less 

stringent than the level of control required by any 

emission limitation in the prior case-by-case MACT 

determination, the permitting authority is not required to 

incorporate any less stringent emission limitation of the 

promulgated standard in the title V permit and may in its 

discretion consider any more stringent provisions of the 

MACT determination to be applicable legal requirements when 

issuing or revising such a title V permit.