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Subpart MMM—National Emission Standards for Hazardous Air 

Pollutants for Pesticide Active Ingredient Production

Table of Contents

§63.1360 Applicability.

§63.1361 Definitions.

§63.1362 Standards.

§63.1363 Standards for equipment leaks.

§63.1364 Compliance dates.

§63.1365 Test methods and initial compliance procedures.

§63.1366 Monitoring and inspection requirements.

§63.1367 Recordkeeping requirements.

§63.1368 Reporting requirements.

§63.1369 Implementation and enforcement.

Tables to Subpart MMM of Part 63

Table 1 to Subpart MMM of Part 63-General Provisions 

Applicability to Subpart MMM

Table 2 to Subpart MMM of Part 63-Standards for New and Existing 

PAI Sources

Table 3 to Subpart MMM of Part 63-Monitoring Requirements for 

Control Devices

Table 4 to Subpart MMM of Part 63-Control Requirements for Items 

of Equipment That Meet the Criteria of 63.1362()

§63.1360 Applicability.

(a) Definition of affected source. The affected source 

subject to this subpart is the facility-wide collection of 

pesticide active ingredient manufacturing process units (PAI 

process units) that process, use, or produce HAP, and are 

located at a plant site that is a major source, as defined in 

section 112(a) of the CAA. An affected source also includes 

waste management units, heat exchange systems, and cooling 

towers that are associated with the PAI process units. 
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Exemptions from an affected source are specified in paragraph 

(d) of this section

(b) New source applicability. A new affected source subject 

to this subpart and to which the requirements for new sources 

apply is defined according to the criteria in paragraph (b)(1) 

or (2) of this section.

(1) An affected source for which construction or 

reconstruction commenced after November 10, 1997.

(2) Any dedicated PAI process unit that meets the criteria 

specified in paragraphs (b)(2)(i) and (ii) of this section.

(i) For which construction, as defined in §63.1361, 

commenced after November 10, 1997, or reconstruction commenced 

after September 20, 2002.

(ii) That has the potential to emit 10 tons/yr of any one 

HAP or 25 tons/yr of combined HAP.

(c) General provisions. Table 1 of this subpart specifies 

the provisions of subpart A of this part that apply to an owner 

or operator of an affected source subject to this subpart, and 

clarifies specific provisions in subpart A of this part as 

necessary for this subpart.

(d) Exemptions from the requirements of this subpart. The 

provisions of this subpart do not apply to:

(1) Research and development facilities;
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(2) PAI process units that are subject to subpart F of this 

part;

(3) Production of ethylene;

(4) Coal tar distillation; and

(5) The following emission points listed:

(i) Storm water from segregated sewers;

(ii) Water from fire-fighting and deluge systems, including 

testing of such systems;

(iii) Spills;

(iv) Water from safety showers;

(v) Noncontact steam boiler blowdown and condensate;

(vi) Laundry water;

(vii) Vessels storing material that contains no organic HAP 

or contains organic HAP as impurities only; and

(viii) Equipment, as defined in §63.1363, that is intended 

to operate in organic HAP service for less than 300 hours during 

the calendar year.

(e) Applicability of this subpart except during periods of 

startup, shutdown, and malfunction. (1) Each provision set forth 

in this subpart shall apply at all times except during periods 

of non-operation of the affected source (or specific portion 

thereof) resulting in cessation of the emissions to which this 

subpart applies except that emission limitations shall not apply 
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during periods of startup, shutdown, and malfunction, as defined 

in §63.1361, if:.

(i) The startup, shutdown, or malfunction precludes the 

ability of the owner or operator of an affected source to comply 

with one or more specific emission limitations to which a 

particular emission point is subject; and

(ii) The owner or operator follows the provisions for 

periods of startup, shutdown, and malfunction, as specified in 

§§63.1367(a)(3) and 63.1368(i).

(2) The provisions set forth in §63.1363 shall apply at all 

times except during periods of nonoperation of the PAI process 

unit (or specific portion thereof) in which the lines are 

drained and depressurized resulting in the cessation of the 

emissions to which §63.1363 applies.

(3) The owner or operator shall not shut down items of 

equipment that are required or utilized for compliance with the 

emissions limitations of this subpart during times when 

emissions (or, where applicable, wastewater streams or 

residuals) are being routed to such items of equipment, if the 

shutdown would contravene emissions limitations of this subpart 

applicable to such items of equipment. This paragraph does not 

apply if the item of equipment is malfunctioning, or if the 

owner or operator must shut down the equipment to avoid damage 

due to a malfunction of the PAI process unit or portion thereof.
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(4) During startups, shutdowns, and malfunctions when the 

emissions limitations of this subpart do not apply pursuant to 

paragraphs (e)(1) through (3) of this section, the owner or 

operator shall implement, to the extent reasonably available, 

measures to prevent or minimize excess emissions. For purposes 

of this paragraph, “excess emissions” means emissions in excess 

of those that would have occurred if there were no startup, 

shutdown, or malfunction and the owner or operator complied with 

the relevant provisions of this subpart. The measures to be 

taken shall be identified in the applicable startup, shutdown, 

and malfunction plan, and may include, but are not limited to, 

air pollution control technologies, work practices, pollution 

prevention, monitoring, and/or changes in the manner of 

operation of the source. Back-up control devices are not 

required, but may be used if available.General duty. At all 

times, the owner or operator must operate and maintain any 

affected source, including associated air pollution control 

equipment and monitoring equipment, in a manner consistent with 

safety and good air pollution control practices for minimizing 

emissions. The general duty to minimize emissions does not 

require the owner or operator to make any further efforts to 

reduce emissions if levels required by the applicable standard 

have been achieved. Determination of whether a source is 

operating in compliance with operation and maintenance 
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requirements will be based on information available to the 

Administrator, which may include, but is not limited to, 

monitoring results, review of operation and maintenance 

procedures, review of operation and maintenance records, and 

inspection of the source.

(f) Storage vessel applicability determination. An owner or 

operator shall follow the procedures specified in paragraphs 

(f)(1) through (5) of this section to determine whether a 

storage vessel is part of the affected source to which this 

subpart applies.

(1) If a storage vessel is already subject to another 

subpart of 40 CFR part 63 on June 23, 1999, the storage vessel 

shall belong to the process unit subject to the other subpart.

(2) Unless otherwise excluded under paragraph (f)(1) of 

this section, the storage vessel is part of a PAI process unit 

if either the input to the vessel from the PAI process unit is 

greater than or equal to the input from any other PAI or non-PAI 

process unit, or the output from the vessel to the PAI process 

unit is greater than or equal to the output to any other PAI or 

non-PAI process unit. If the greatest input to and/or output 

from a shared storage vessel is the same for two or more process 

units, including one or more PAI process units, the owner or 

operator must assign the storage vessel to any one of the PAI 

process units that meet this condition.
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(3) Unless otherwise excluded under paragraph (f)(1) of 

this section, where a storage vessel is located in a tank farm 

(including a marine tank farm), the applicability of this 

subpart shall be determined according to the provisions in 

paragraphs (f)(3)(i) through (iii) of this section.

(i) The storage vessel in the tank farm is not subject to 

the provisions of this subpart if the greatest input to or 

output from the storage vessel is for a non-PAI process unit. 

The input and output shall be determined among only those 

process units that share the storage vessel and that do not have 

an intervening storage vessel for that product (or raw material, 

as appropriate)

(ii) Except for storage vessels in a tank farm excluded in 

accordance with paragraph (f)(3)(i) of this section, 

applicability of this subpart shall be determined according to 

the provisions in paragraphs (f)(3)(ii)(A) through (C) of this 

section.

(A) Except as specified in paragraph (f)(3)(ii)(C) of this 

section, this subpart does not apply to the storage vessel in a 

tank farm if each PAI process unit that receives material from 

or sends material to the storage vessel has an intervening 

storage vessel for that material.

(B) Except as specified in paragraph (f)(3)(ii)(C) of this 

section, a storage vessel in a tank farm shall be assigned to 
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the PAI process unit that receives the greatest amount of 

material from or sends the greatest amount of material to the 

storage vessel and does not have an intervening storage vessel. 

If two or more PAI process units have the same input to or 

output from the storage vessel in the tank farm, then the 

storage vessel in the tank farm may be assigned to any one of 

the PAI process units that meet this condition.

(C) As an alternative to the requirements specified in 

paragraphs (f)(3)(ii)(A) and (B) of this section, even if an 

intervening storage vessel is present, an owner or operator may 

elect to assign a storage vessel in a tank farm to the PAI 

process unit that sends the most material to or receives the 

most material from the storage vessel. If two or more PAI 

process units have the same input to or output from the storage 

vessel in the tank farm, then the storage vessel in the tank 

farm may be assigned to any one of the PAI process units that 

meet this condition.

(iii) With respect to a process unit, an intervening 

storage vessel means a storage vessel connected by hard-piping 

to the process unit and to the storage vessel in the tank farm 

so that the product or raw material entering or leaving the 

process flows into (or from) the intervening storage vessel and 

does not flow directly into (or from) the storage vessel in the 

tank farm.
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(4) If use varies from year to year, then use for the 

purposes of this subpart for existing sources shall be based on 

the utilization that occurred during the year preceding June 23, 

1999, or if the storage vessel was not in operation during that 

year, the use shall be based on the expected use in the 5 years 

after startup. This determination shall be reported as part of 

an operating permit application or as otherwise specified by the 

permitting authority.

(5) If the storage vessel begins receiving material from 

(or sending material to) another process unit, or ceasing to 

receive material from (or send material to) a PAI process unit, 

or if there is a significant change in the use of the storage 

vessel, the owner or operator shall reevaluate the ownership 

determination for the storage vessel.

(g) Designating production of an intermediate as a PAI 

process unit. Except as specified in paragraph (d) of this 

section, an owner or operator may elect to designate production 

of any intermediate that does not meet the definition of 

integral intermediate as a PAI process unit subject to this 

subpart. Any storage vessel containing the intermediate is 

assigned to a PAI process unit according to the procedures in 

paragraph (f) of this section. Any process tank containing the 

intermediate is part of the process unit used to produce the 

intermediate.
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(h) Applicability of process units included in a process 

unit group. An owner or operator may elect to develop process 

unit groups in accordance with paragraph (h)(1) of this section. 

For the PAI process units in these process unit groups, the 

owner or operator may comply with the provisions in overlapping 

MACT standards, as specified in paragraphs (h)(2) through (4) of 

this section, as an alternative means of demonstrating 

compliance with the provisions of this subpart.

(1) Develop, revise, and document changes in a process unit 

group in accordance with the procedures specified in paragraphs 

(h)(1)(i) through (vi) of this section.

(i) Initially identify a non-dedicated PAI process unit 

that is operating on December 23, 2003 or a date after December 

23, 2003, and identify all processing equipment that is part of 

this PAI process unit, based on descriptions in operating 

scenarios.

(ii) Add to the group any other non-dedicated PAI and nondedicated non-PAI process units expected to be operated in the 5 

years after the date specified in paragraph (h)(1)(i) of this 

section, provided they satisfy the criteria specified in 

paragraphs (h)(1)(ii)(A) through (C) of this section. Also 

identify all of the processing equipment used for each process 

unit based on information from operating scenarios and other 

applicable documentation.
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(A) Each PAI process unit that is added to a group must 

have some processing equipment that is part of one or more PAI 

process units that are already in the process unit group.

(B) Each non-PAI process unit that is added to a group must 

have some processing equipment that is also part of one or more 

of the PAI process units in the group.

(C) No process unit may be part of more than one process 

unit group.

(iii) The initial process unit group consists of all of the 

processing equipment for the process units identified in 

paragraphs (h)(1)(i) and (ii) of this section.

(iv) If compliance is to be demonstrated in accordance with 

paragraph (h)(3) of this section, determine the primary product 

of the process unit group according to the procedures specified 

in paragraphs (h)(1)(iv)(A) through (C) of this section.

(A) The primary product is the type of product (e.g., PAI, 

pharmaceutical product, thermoplastic resin, etc.) that is 

expected to be produced for the greatest operating time in the 

5-year period specified in paragraph (h)(1)(i) of this section.

(B) If the process unit group produces multiple products 

equally based on operating time, then the primary product is the 

product with the greatest production on a mass basis over the 5-

year period specified in paragraph (h)(1)(i) of this section.
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(C) The primary product of the group must be redetermined 

if the owner or operator does not intend to make that product in 

the future or if it has not been made for 5 years. The results 

of the redetermination must be recorded as specified in 

§63.1367(b) and reported in a Periodic report no later than the 

report covering the period for the end of the 5th year as 

specified in §63.1368(g)(2). If the primary product changes, the 

owner or operator must either demonstrate compliance with the 

applicable subpart as specified in paragraph (h)(3) of this 

section or demonstrate compliance with the provisions of this 

subpart MMM.

(v) Add process units developed in the future in accordance 

with the conditions specified in paragraphs (h)(1)(ii)(A) 

through (C) of this section.

(vi) Maintain records of changes in the process units in 

each process unit group as specified in §63.1367(b)(9), and 

maintain reports as specified in §63.1368(f)(9) and (g)(2)(ix).

(2) If any of the products produced in the process unit 

group are subject to 40 CFR part 63, subpart GGG 

(Pharmaceuticals MACT), the owner or operator may elect to 

comply with the requirements of subpart GGG for the PAI process 

unit(s) within the process unit group, except for the following:

(i) The emission limit standard for process vents in 

§63.1362(b)(2)(i) shall apply in place of §63.1254(a)(2);
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(ii) When the dates of April 2, 1997 and April 2, 2007 are 

provided in §63.1254(a)(3)(ii), the dates of November 10, 1997 

and November 10, 2007, respectively, shall apply for purposes of 

this subpart MMM; and

(iii) Requirements in §63.1367(a)(5) regarding application 

for approval of construction or reconstruction shall apply in 

place of the provisions in §63.1259(a)(5).

(3) If the primary product of a process unit group is 

determined to be a type of material that is subject to another 

subpart of 40 CFR part 63 on June 23, 1999 or startup of the 

first process unit after formation of the process unit group, 

whichever is later, the owner or operator may elect to comply 

with the other subpart for any PAI process unit within the 

process unit group, subject to the requirement in this paragraph 

(h)(3). Emissions from PAI Group 1 process vents, as defined in 

§63.1361, must be reduced in accordance with the control 

requirements for Group 1 vents as specified in the alternative 

subpart. The criteria in the alternative subpart for determining 

which process vents must be controlled do not apply for the 

purposes of this paragraph (h)(3).

(4) The requirements for new and reconstructed sources in 

the alternative subpart apply to all PAI process units in the 

process unit group if, and only if, the affected source under 
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the alternative subpart meets the requirements for construction 

or reconstruction.

(i) Overlap with other regulations - (1) Compliance with 

other MACT standards. (i) After the compliance dates specified 

in §63.1364, an affected source subject to the provisions of 

this subpart that is also subject to the provisions of any other 

subpart of 40 CFR part 63 may elect, to the extent the subparts 

are consistent, under which subpart to maintain records and 

report to EPA. The affected source shall identify in the 

Notification of Compliance Status report required by §63.1368(f) 

under which authority such records will be maintained.

(ii) After the compliance dates specified in §63.1364, at 

an offsite reloading or cleaning facility subject to 

§63.1362(b)(6), compliance with the emission standards and 

associated initial compliance monitoring, recordkeeping, and 

reporting provisions of any other subpart of 40 CFR part 63 

constitutes compliance with the provisions of 

§63.1362(b)(6)(vii)(B) or (C). The owner or operator of the 

affected storage vessel shall identify in the Notification of 

Compliance Status report required by §63.1368(f) the subpart of 

40 CFR part 63 with which the owner or operator of the offsite 

reloading or cleaning facility complies.

(2) Overlap with RCRA subparts AA, BB, and/or CC. After the 

compliance dates specified in §63.1364, if any affected source 
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subject to this subpart is also subject to monitoring, 

recordkeeping, and reporting requirements in 40 CFR part 264, 

subpart AA, BB, or CC, or is subject to monitoring and 

recordkeeping requirements in 40 CFR part 265, subpart AA, BB, 

or CC, and the owner or operator complies with the periodic 

reporting requirements under 40 CFR part 264, subpart AA, BB, or 

CC that would apply to the device if the facility had finalpermitted status, the owner or operator may elect to comply 

either with the monitoring, recordkeeping, and reporting 

requirements of this subpart, or with the monitoring, 

recordkeeping, and reporting requirements in 40 CFR parts 264 

and/or 265, as described in this paragraph, which shall 

constitute compliance with the monitoring, recordkeeping, and 

reporting requirements of this subpart. If the owner or operator 

elects to comply with the monitoring, recordkeeping, and 

reporting requirements in 40 CFR parts 264 and/or 265, the owner 

or operator shall report all excursions as required by 

§63.1368(g). The owner or operator shall identify in the 

Notification of Compliance Status report required by §63.1368(f) 

the monitoring, recordkeeping, and reporting authority under 

which the owner or operator will comply.

(3) Overlap with NSPS subpart Kb. After the compliance 

dates specified in §63.1364, a Group 1 or Group 2 storage vessel 

that is also subject to the provisions of 40 CFR part 60, 
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subpart Kb, is required to comply only with the provisions of 

this subpart MMM.

(4) Overlap with subpart I. After the compliance dates 

specified in §63.1364, for all equipment within a process unit 

that contains equipment subject to subpart I of this part, an 

owner or operator may elect to comply with either the provisions 

of this subpart MMM or the provisions of subpart H of this part. 

The owner or operator shall identify in the Notification of 

Compliance Status report required by §63.1368(f) the provisions 

with which the owner or operator elects to comply.

(5) Overlap with RCRA regulations for wastewater. After the 

compliance dates specified in §63.1364, the owner or operator of 

an affected wastewater stream that is also subject to provisions 

in 40 CFR parts 260 through 272 shall comply with the more 

stringent control requirements (e.g., waste management units, 

numerical treatment standards, etc.) and the more stringent 

testing, monitoring, recordkeeping, and reporting requirements 

that overlap between the provisions of this subpart and the 

provisions of 40 CFR parts 260 through 272. The owner or 

operator shall keep a record of the information used to 

determine which requirements were the most stringent and shall 

submit this information if requested by the Administrator.

(6) Overlap with NSPS subparts III, NNN, and RRR. After the 

compliance dates specified in §63.1364, if an owner or operator 
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of a process vent subject to this subpart MMM that is also 

subject to the provisions of 40 CFR part 60, subpart III, or 

subpart NNN, or subpart RRR, elects to reduce organic HAP 

emissions from the process vent by 98 percent as specified in 

§63.1362(b)(2)(iii)(A), then the owner or operator is required 

to comply only with the provisions of this subpart MMM. 

Otherwise, the owner or operator shall comply with the 

provisions in both this subpart MMM and the provisions in 40 CFR 

part 60, subparts III, NNN, and RRR, as applicable.

(j) Meaning of periods of time. All terms in this subpart 

MMM that define a period of time for completion of required 

tasks (e.g., weekly, monthly, quarterly, annual), unless 

specified otherwise in the section or subsection that imposes 

the requirement, refer to the standard calendar periods.

(1) Notwithstanding time periods specified in the subpart 

MMM for completion of required tasks, such time periods may be 

changed by mutual agreement between the owner and operator and 

the Administrator, as specified in subpart A of this part (e.g., 

a period could begin on the compliance date or another date, 

rather than on the first day of the standard period). For each 

time period that is changed by agreement, the revised period 

shall remain in effect until it is changed. A new request is not 

necessary for each recurring period.
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(2) Where the period specified for compliance is a standard 

calendar period, if the initial compliance date occurs after the 

beginning of the period, compliance shall be required according 

to the schedule specified in paragraph (j)(2)(i) or (ii) of this 

section, as appropriate.

(i) Compliance shall be required before the end of the 

standard calendar period within which the compliance deadline 

occurs, if there remain at least 3 days for tasks that must be 

performed weekly, at least 2 weeks for tasks that must be 

performed monthly, at least 1 month for tasks that must be 

performed each quarter, or at least 3 months for tasks that must 

be performed annually; or

(ii) In all other cases, compliance shall be required 

before the end of the first full standard calendar period within 

which the initial compliance deadline occurs.

(3) In all instances where a provision of this subpart MMM 

requires completion of a task during each of multiple successive 

periods, an owner or operator may perform the required task at 

any time during the specified period, provided the task is 

conducted at a reasonable interval after completion of the task 

in the previous period.

(k) Affirmative defense for violation of emission standards 

during malfunction. In response to an action to enforce the 

standards set forth in this subpart, the owner or operator may 
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assert an affirmative defense to a claim for civil penalties for 

violations of such standards that are caused by malfunction, as 

defined at §63.2. Appropriate penalties may be assessed if the 

owner or operator fails to meet their burden of proving all of 

the requirements in the affirmative defense. The affirmative 

defense shall not be available for claims for injunctive relief.

(1) Assertion of affirmative defense. To establish the 

affirmative defense in any action to enforce such a standard, 

the owner or operator must timely meet the reporting 

requirements in paragraph (k)(2) of this section, and must prove 

by a preponderance of evidence that:

(i) The violation: 

(A) Was caused by a sudden, infrequent, and unavoidable 

failure of air pollution control equipment, process equipment, 

or a process to operate in a normal or usual manner, and 

(B) Could not have been prevented through careful planning, 

proper design or better operation and maintenance practices; and

(C) Did not stem from any activity or event that could have 

been foreseen and avoided, or planned for; and

(D) Was not part of a recurring pattern indicative of 

inadequate design, operation, or maintenance; and

(ii) Repairs were made as expeditiously as possible when a 

violation occurred; and
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(iii) The frequency, amount, and duration of the violation 

(including any bypass) were minimized to the maximum extent 

practicable; and

(iv) If the violation resulted from a bypass of control 

equipment or a process, then the bypass was unavoidable to 

prevent loss of life, personal injury, or severe property 

damage; and

(v) All possible steps were taken to minimize the impact of 

the violation on ambient air quality, the environment and human 

health; and

(vi) All emissions monitoring and control systems were kept 

in operation if at all possible, consistent with safety and good 

air pollution control practices; and

(vii) All of the actions in response to the violation were 

documented by properly signed, contemporaneous operating logs; 

and

(viii) At all times, the affected source was operated in a 

manner consistent with good practices for minimizing emissions; 

and

(ix) A written root cause analysis has been prepared, the 

purpose of which is to determine, correct, and eliminate the 

primary causes of the malfunction and the violation resulting 

from the malfunction event at issue. The analysis shall also 

specify, using best monitoring methods and engineering judgment, 
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the amount of any emissions that were the result of the 

malfunction.

(2) Report. The owner or operator seeking to assert an 

affirmative defense shall submit a written report to the 

Administrator, with all necessary supporting documentation, that 

explains how it has met the requirements set forth in paragraph 

(k)(1) of this section. This affirmative defense report shall be 

included in the first periodic compliance report, deviation 

report or excess emission report otherwise required after the 

initial occurrence of the violation of the relevant standard 

(which may be the end of any applicable averaging period). If 

such compliance report, deviation report or excess emission 

report is due less than 45 days after the initial occurrence of 

the violation, the affirmative defense report may be included in 

the second compliance report, deviation report or excess 

emission report due after the initial occurrence of the 

violation of the relevant standard.

§63.1361 Definitions.

Terms used in this subpart are defined in the CAA, in 

subpart A of this part, or in this section. If the same term is 

defined in subpart A of this part and in this section, it shall 

have the meaning given in this section for the purposes of this 

subpart MMM.
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Affirmative defense means, in the context of an enforcement 

proceeding, a response or defense put forward by a defendant, 

regarding which the defendant has the burden of proof, and the 

merits of which are independently and objectively evaluated in a 

judicial or administrative proceeding.

Air pollution control device or control device means 

equipment installed on a process vent, storage vessel, 

wastewater treatment exhaust stack, or combination thereof that 

reduces the mass of HAP emitted to the air. The equipment may 

consist of an individual device or a series of devices. Examples 

include incinerators, carbon adsorption units, condensers, 

flares, boilers, process heaters, and gas absorbers. Process 

condensers are not considered air pollution control devices or 

control devices.

Bag dump means equipment into which bags or other 

containers containing a powdered, granular, or other solid 

feedstock material are emptied. A bag dump is part of the 

process.

Batch emission episode means a discrete venting episode 

that is associated with a single unit operation. A unit 

operation may have more than one batch emission episode. For 

example, a batch distillation unit operation may consist of 

batch emission episodes associated with charging and heating. 

Charging the vessel with HAP will result in one discrete batch 
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emission episode that will last through the duration of the 

charge and will have an average flowrate equal to the rate of 

the charge. Another discrete batch emission episode will result 

from the expulsion of expanded vapor as the contents of the 

vessel are heated.

Batch operation means a noncontinuous operation involving 

intermittent or discontinuous feed into PAI or integral 

intermediate manufacturing equipment, and, in general, involves 

the emptying of the equipment after the batch operation ceases 

and prior to beginning a new operation. Addition of raw material 

and withdrawal of product do not occur simultaneously in a batch 

operation. A batch process consists of a series of batch 

operations.

Bench-scale batch process means a batch process (other than 

a research and development facility) that is capable of being 

located on a laboratory bench top. This bench-scale equipment 

will typically include reagent feed vessels, a small reactor and 

associated product separator, recovery and holding equipment. 

These processes are only capable of producing small quantities 

of product.

Block means a time period equal to, at a maximum, the 

duration of a single batch.

Car seal means a seal that is placed on a device that is 

used to change the position of a valve (e.g., from opened to 
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closed) in such a way that the position of the valve cannot be 

changed without breaking the seal.

Cleaning operation means routine rinsing, washing, or boiloff of equipment in batch operations between batches.

Closed-loop system means an enclosed system that returns 

process fluid to the process and is not vented to the atmosphere 

except through a closed-vent system.

Closed-purge system means a system or combination of system 

and portable containers, to capture purged liquids. Containers 

must be covered or closed when not being filled or emptied.

Closed-vent system means a system that is not open to the 

atmosphere and is composed of piping, ductwork, connections, 

and, if necessary, flow inducing devices that transport gas or

vapor from an emission point to a control device.

Combustion device means an individual unit of equipment, 

such as a flare, incinerator, process heater, or boiler, used 

for the combustion of organic HAP vapors.

Connector means flanged, screwed, or other joined fittings 

used to connect two pipe lines or a pipe line and a piece of 

equipment. A common connector is a flange. Joined fittings 

welded completely around the circumference of the interface are 

not considered connectors for the purpose of this regulation. 

For the purpose of reporting and record keeping, connector means 
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joined fittings that are not inaccessible, ceramic, or ceramiclined as described in §63.1255(b)(1)(vii) and 63.1255(f)(3).

Construction means the onsite fabrication, erection, or 

installation of an affected source or dedicated PAI process 

unit. Addition of new equipment to an affected source does not 

constitute construction, provided the new equipment is not a 

dedicated PAI process unit with the potential to emit 10 tons/yr 

of any one HAP or 25 tons/yr of combined HAP, but it may 

constitute reconstruction of the affected source or PAI process 

unit if it satisfies the definition of reconstruction in this 

section. At an affected source, changing raw materials processed 

and reconfiguring non-dedicated equipment to create a nondedicated PAI process unit do not constitute construction.

Consumption means the quantity of all HAP raw materials 

entering a process in excess of the theoretical amount used as 

reactant, assuming 100 percent stoichiometric conversion. The 

raw materials include reactants, solvents, and any other 

additives. If HAP are generated in the process as well as added 

as raw material, consumption includes the quantity generated in 

the process.

Container, as used in the wastewater provisions, means any 

portable waste management unit that has a capacity greater than 

or equal to 0.1 m3 in which a material is stored, transported, 

treated, or otherwise handled. Examples of containers are drums, 
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barrels, tank trucks, barges, dumpsters, tank cars, dump trucks, 

and ships.

Continuous process means a process where the inputs and 

outputs flow continuously throughout the duration of the 

process. Continuous processes typically approach steady state.

Continuous seal means a seal that forms a continuous 

closure that completely covers the space between the wall of the 

storage vessel and the edge of the floating roof. A continuous 

seal may be a vapor-mounted, liquid-mounted, or metallic shoe 

seal.

Controlled HAP emissions means the quantity of HAP 

components discharged to the atmosphere from an air pollution 

control device.

Cover, as used in the wastewater provisions, means a device 

or system which is placed on or over a waste management unit 

containing wastewater or residuals so that the entire surface 

area is enclosed to minimize air emissions. A cover may have 

openings necessary for operation, inspection, and maintenance of 

the waste management unit such as access hatches, sampling 

ports, and gauge wells provided that each opening is closed when 

not in use. Examples of covers include a fixed roof installed on 

a wastewater tank, a lid installed on a container, and an airsupported enclosure installed over a waste management unit.
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Dedicated PAI process unit means a PAI process unit 

constructed from equipment that is fixed in place and designed 

and operated to produce only a single product or co-products. 

The equipment is not designed to be reconfigured to create 

different process units, and it is not operated with different 

raw materials so as to produce different products.

Double block and bleed system means two block valves 

connected in series with a bleed valve or line that can vent the 

line between the two block valves.

Duct work means a conveyance system such as those commonly 

used for heating and ventilation systems. It is often made of 

sheet metal and often has sections connected by screws or 

crimping. Hard-piping is not ductwork.

Equipment, for purposes of §63.1363, means each pump, 

compressor, agitator, pressure relief device, sampling 

connection system, open-ended valve or line, valve, connector, 

and instrumentation system in organic hazardous air pollutant 

service.

External floating roof means a pontoon-type or double-deck 

type cover that rests on the liquid surface in a storage tank or 

waste management unit with no fixed roof.

FIFRA means the Federal Insecticide, Fungicide, and 

Rodenticide Act.
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Fill or filling means the introduction of organic HAP into 

a storage tank or the introduction of a wastewater stream or 

residual into a waste management unit, but not necessarily to 

complete capacity.

First attempt at repair means to take action for the 

purpose of stopping or reducing leakage of organic material to 

the atmosphere.

Fixed roof means a cover that is mounted on a waste 

management unit or storage tank in a stationary manner and that 

does not move with fluctuations in liquid level.

Flame ionization detector (FID) means a device in which the 

measured change in conductivity of a standard flame (usually 

hydrogen) due to the insertion of another gas or vapor is used 

to detect the gas or vapor.

Floating roof means a cover consisting of a double deck, 

pontoon single deck, internal floating cover or covered floating 

roof, which rests upon and is supported by the liquid being 

contained, and is equipped with a continuous seal or seals to 

close the space between the roof edge and waste management unit 

or storage vessel wall.

Flow indicator means a device that indicates whether gas 

flow is, or whether the valve position would allow gas flow to 

be, present in a line.
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Formulation of pesticide products means the mixing, 

blending, or diluting of a PAI with one or more other PAI or 

inert ingredients.

Group 1 process vent means any process vent from a process 

at an existing or new affected source for which the uncontrolled 

organic HAP emissions from the sum of all process vents are 

greater than or equal to 0.15 Mg/yr and/or the uncontrolled 

hydrogen chloride (HCl) and chlorine emissions from the sum of 

all process vents are greater than or equal to 6.8 Mg/yr.

Group 2 process vent means any process vent that does not 

meet the definition of a Group 1 process vent.

Group 1 storage vessel means a storage vessel at an 

existing affected source with a capacity equal to or greater 

than 75 m3 and storing material with a maximum true vapor 

pressure greater than or equal to 3.45 kPa, a storage vessel at 

a new affected source with a capacity equal to or greater than 

40 m3 and storing material with a maximum true vapor pressure 

greater than or equal to 16.5 kPa, or a storage vessel at a new 

affected source with a capacity greater than or equal to 75 

m

3 and storing material with a maximum true vapor pressure 

greater than or equal to 3.45 kPa.

Group 2 storage vessel means a storage vessel that does not 

meet the definition of a Group 1 storage vessel.
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Group 1 wastewater stream means process wastewater at an 

existing or new source that meets the criteria for Group 1 

status in §63.132(c) for compounds in Table 9 of subpart G of 

this part or a maintenance wastewater stream that contains 5.3 

Mg of compounds in Table 9 of subpart G of this part per 

discharge event.

Group 2 wastewater stream means any wastewater stream that 

does not meet the definition of a Group 1 wastewater stream.

Group of processes means all of the equipment associated 

with processes in a building, processing area, or facility-wide. 

A group of processes may consist of a single process.

Halogenated compounds means organic compounds that contain 

chlorine atoms.

Halogenated vent stream means a process, storage vessel, or 

waste management unit vent stream determined to have a 

concentration of halogenated compounds of greater than 20 ppmv, 

as determined through process knowledge, test results using 

Method 18 of 40 CFR part 60, appendix A, or test results using 

any other test method that has been validated according to the 

procedures in Method 301 of appendix A of this part.

Hard-piping means piping or tubing that is manufactured and 

properly installed using good engineering judgment and 

standards, such as ANSI B31–3.
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Impurity means a substance that is produced coincidentally 

with the product(s), or is present in a raw material. An 

impurity does not serve a useful purpose in the production or 

use of the product(s) and is not isolated.

In gas/vapor service means that a piece of equipment in 

organic HAP service contains a gas or vapor at operating 

conditions.

In heavy liquid service means that a piece of equipment in 

organic HAP service is not in gas/vapor service or in light 

liquid service.

In light liquid service means that a piece of equipment in 

organic HAP service contains a liquid that meets the following 

conditions:

(1) The vapor pressure of one or more of the organic 

compounds is greater than 0.3 kPa at 20 °C;

(2) The total concentration of the pure organic compounds 

constituents having a vapor pressure greater than 0.3 kPa at 20 

°C is equal to or greater than 20 percent by weight of the total 

process stream; and

(3) The fluid is a liquid at operating conditions.

Note: To definition of “In light liquid service: Vapor 

pressures may be determined by the methods described in 40 CFR 

60.485(e)(1).
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In liquid service means that a piece of equipment in 

organic HAP service is not in gas/vapor service.

In organic hazardous air pollutant or in organic HAP 

service means that a piece of equipment either contains or 

contacts a fluid (liquid or gas) that is at least 5 percent by 

weight of total organic HAP as determined according to the 

provisions of §63.180(d) of subpart H of this part. The 

provisions of §63.180(d) of subpart H of this part also specify 

how to determine that a piece of equipment is not in organic HAP 

service.

In vacuum service means that equipment is operating at an 

internal pressure which is at least 5 kPa below ambient 

pressure.

In-situ sampling systems means nonextractive samplers or 

in-line samplers.

Individual drain system means the stationary system used to 

convey wastewater streams or residuals to a waste management 

unit or to discharge or disposal. The term includes: hard 

piping; all process drains and junction boxes; and associated 

sewer lines, other junction boxes, manholes, sumps, and lift 

stations conveying wastewater streams or residuals. A segregated 

stormwater sewer system, which is a drain and collection system 

designed and operated for the sole purpose of collecting 

rainfall-runoff at a facility, and which is segregated from all 
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other individual drain systems, is excluded from this 

definition.

Instrumentation system means a group of equipment 

components used to condition and convey a sample of the process 

fluid to analyzers and instruments for the purpose of 

determining process operating conditions (e.g., composition, 

pressure, flow, etc.). Valves and connectors are the predominant 

type of equipment used in instrumentation systems; however, 

other types of equipment may also be included in these systems. 

Only valves nominally 0.5 inches and smaller and connectors 

nominally 0.75 inches and smaller in diameter are considered 

instrumentation systems for the purposes of this subpart. Valves 

greater than nominally 0.5 inches and connectors greater than 

nominally 0.75 inches associated with instrumentation systems 

are not considered part of instrumentation systems and must be 

monitored individually.

Integral intermediate means an intermediate for which 50 

percent or more of the annual production is used in on-site 

production of any PAI(s) and that is not stored before being 

used in the production of another integral intermediate or the 

PAI(s). For the purposes of this definition, an intermediate is 

stored if it is discharged to a storage vessel and at least one 

of the following conditions is met: the processing equipment 

that discharges to the storage vessel is shutdown before the 
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processing equipment that withdraws from the storage vessel is 

started up; during an annual period, the material must be stored 

in the vessel for at least 30 days before being used to make a 

PAI; or the processing equipment that discharges to the storage 

vessel is located in a separate building (or processing area) of 

the plant than the processing equipment that uses material from 

the storage vessel as a feedstock, and control equipment is not 

shared by the two processing areas. Any process unit that 

produces an intermediate and is subject to subpart F of this 

part is not an integral intermediate.

Intermediate means an organic compound that is manufactured 

in a process and that is further processed or modified in one or 

more additional steps to ultimately produce a PAI.

Internal floating roof means a cover that rests or floats

on the liquid surface (but not necessarily in complete contact 

with it) inside a storage tank or waste management unit that has 

a permanently affixed roof.

Junction box means a manhole or access point to a 

wastewater sewer system line or a lift station.

Large control device means a control device that controls 

process vents, and the total HAP emissions into the control 

device from all sources are greater than or equal to 10 tons/yr.

Liquid-mounted seal means a foam- or liquid-filled seal 

mounted in contact with the liquid between the wall of the 
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storage vessel or waste management unit and the floating roof. 

The seal is mounted continuously around the tank or unit.

Liquids dripping means any visible leakage from the seal 

including dripping, spraying, misting, clouding, and ice 

formation. Indications of liquid dripping include puddling or 

new stains that are indicative of an existing evaporated drip.

Maintenance wastewater means wastewater generated by the 

draining of process fluid from components in the PAI process 

unit into an individual drain system prior to or during 

maintenance activities. Maintenance wastewater can be generated 

through planned or unplanned shutdowns and during periods not 

associated with a shutdown. Examples of activities that can 

generate maintenance wastewaters include descaling of heat 

exchanger tubing bundles, cleaning of distillation column traps, 

draining of low legs and high point bleeds, draining of pumps 

into an individual drain system, and draining of portions of the 

PAI process unit for repair.

Malfunction means any sudden, infrequent, and not 

reasonably preventable failure of air pollution control 

equipment, emissions monitoring equipment, process equipment, or 

a process to operate in a normal or usual manner which causes, 

or has the potential to cause, the emission limitations in an 

applicable standard to be exceeded. Failures that are caused all 
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or in part by poor maintenance or careless operation are not 

malfunctions.

Maximum true vapor pressure means the equilibrium partial 

pressure exerted by the total organic HAP in the stored or 

transferred liquid at the temperature equal to the highest 

calendar-month average of the liquid storage or transferred 

temperature for liquids stored or transferred above or below the 

ambient temperature or at the local maximum monthly average 

temperature as reported by the National Weather Service for 

liquids stored or transferred at the ambient temperature, as 

determined:

(1) In accordance with methods described in Chapter 19.2 of 

the American Petroleum Institute's Manual of Petroleum 

Measurement Standards, Evaporative Loss From Floating-Roof Tanks 

(incorporated by reference as specified in §63.14 in subpart A 

of this part); or

(2) As obtained from standard reference texts; or

(3) As determined by the American Society for Testing and 

Materials Method D2879–97, Test Method for Vapor PressureTemperature Relationship and Initial Decomposition Temperature 

of Liquids by Isoteniscope (incorporated by reference as 

specified in §63.14 of subpart A of this part); or

(4) Any other method approved by the Administrator.
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Metallic shoe seal or mechanical shoe seal means metal 

sheets that are held vertically against the wall of the storage 

tank by springs, weighted levers, or other mechanisms and 

connected to the floating roof by braces or other means. A 

flexible coated fabric (envelope) spans the annular space 

between the metal sheet and the floating roof.

Non-dedicated PAI process unit means a process unit that is 

not a dedicated PAI process unit.

Nonrepairable means that it is technically infeasible to 

repair a piece of equipment from which a leak has been detected 

without a process shutdown.

Open-ended valve or line means any valve, except pressure 

relief valves, having one side of the valve seat in contact with 

process fluid and one side open to atmosphere, either directly 

or through open piping.

Operating scenario, for the purposes of reporting and 

recordkeeping, means a description of a PAI process unit, 

including: identification of each wastewater point of 

determination (POD) and process vent, their associated emissions 

episodes and durations, and their associated level of control 

and control devices, as applicable; calculations and engineering 

analyses required to demonstrate compliance; and a description 

of operating and/or testing conditions for any associated 

control device.
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Organic compound, as used in the definitions of 

intermediate and PAI, means any compound that contains both 

carbon and hydrogen with or without other elements.

Organic HAP means those HAP listed in section 112(b) of the 

CAA that are measured according to the procedures of Method 18 

or Method 25A, 40 CFR part 60, appendix A.

Pesticide active ingredient or PAI means any material that 

is an active ingredient within the meaning of FIFRA section 

2(a); that is used to produce an insecticide, herbicide, or 

fungicide end use pesticide product; that consists of one or 

more organic compounds; and that must be labeled in accordance 

with 40 CFR part 156 for transfer, sale, or distribution. These 

materials are typically described by North American Industrial 

Classification System (NAICS) Codes 325199 and 32532 (i.e., 

previously known as Standard Industrial Classification System 

Codes 2869 and 2879). These materials are identified by product 

classification codes 01, 21, 02, 04, 44, 07, 08, and 16 in block 

19 on the 1999 version of EPA form 3540–16, the Pesticides 

Report for Pesticide-Producing Establishments. The materials 

represented by these codes are: insecticides; insecticidefungicides; fungicides; herbicides; herbicide-fungicides; plant 

regulators; defoliants, desiccants; or multi-use active 

ingredients.
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Pesticide active ingredient manufacturing process unit (PAI 

process unit) means a process unit that is used to produce a 

material that is primarily used as a PAI or integral 

intermediate. A PAI process unit consists of: the process, as 

defined in this subpart; associated storage vessels, as 

determined by the procedures in §63.1360(f); equipment 

identified in §63.1362(k); connected piping and ducts; and 

components such as pumps, compressors, agitators, pressure 

relief devices, sampling connection systems, open-ended valves 

or lines, valves, connectors, and instrumentation systems. A 

material is primarily used as a PAI or integral intermediate if 

more than 50 percent of the projected annual production from a 

process unit in the 3 years after June 23, 1999 or startup, 

whichever is later, is used as a PAI or integral intermediate; 

recordkeeping is required if the material is used as a PAI or 

integral intermediate, but not as the primary use. If the 

primary use changes to a PAI or integral intermediate, the 

process unit becomes a PAI process unit unless it is already 

subject to the HON. If the primary use changes from a PAI or 

integral intermediate to another use, the process unit remains a 

PAI process unit. Any process tank containing an integral 

intermediate is part of the PAI process unit used to produce the 

integral intermediate. A process unit that produces an 

intermediate that is not an integral intermediate may be 
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designated as a PAI process unit according to the procedures of 

§63.1360(g). Formulation of pesticide products is not considered 

part of a PAI process unit. Quality assurance and quality 

control laboratories are not considered part of a PAI process 

unit.

Plant site means all contiguous or adjoining property that 

is under common control, including properties that are separated 

only by a road or other public right-of-way. Common control 

includes properties that are owned, leased, or operated by the 

same entity, parent entity, subsidiary, or any combination 

thereof.

Point of determination (POD) means each point where a 

wastewater stream exits the PAI process unit.

Note to definition of “point of determination”: The 

regulation allows determination of the characteristics of a 

wastewater stream: at the point of determination; or downstream 

of the point of determination if corrections are made for 

changes in flow rate and annual average concentration of Table 9 

compounds as determined in §63.144 of subpart G of this part. 

Such changes include: losses by air emissions, reduction of 

annual average concentration or changes in flow rate by mixing 

with other water or wastewater streams, and reduction in flow 

rate or annual average concentration by treating or otherwise 

handling the wastewater stream to remove or destroy HAP.
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Pressure release means the emission of materials resulting 

from the system pressure being greater than the set pressure of 

the pressure relief device. This release can be one release or a 

series of releases over a short time period due to a malfunction 

in the process.

Pressure relief device or valve means a safety device used 

to prevent operating pressures from exceeding the maximum 

allowable working pressure of the process equipment. A common 

pressure relief device is a spring-loaded pressure relief valve. 

Devices that are actuated either by a pressure of less than or 

equal to 2.5 pounds per square inch gauge or by a vacuum are not 

pressure relief devices.

Process means a logical grouping of processing equipment 

which collectively function to produce a product. For the 

purpose of this subpart, a PAI process includes all, or a 

combination of, reaction, recovery, separation, purification, 

treatment, cleaning, and other activities or unit operations 

which are used to produce a PAI or integral intermediate. 

Ancillary activities are not considered a PAI process or any 

part of a PAI process. Ancillary activities include boilers and 

incinerators (not used to comply with the provisions of 

§63.1362), chillers or refrigeration systems, and other 

equipment and activities that are not directly involved (i.e., 

they operate within a closed system and materials are not 
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combined with process fluids) in the processing of raw materials 

or the manufacturing of a PAI. A PAI process and all integral 

intermediate processes for which 100 percent of the annual 

production is used in the production of the PAI may be linked 

together and defined as a single PAI process unit.

Process condenser means a condenser whose primary purpose 

is to recover material as an integral part of a unit operation. 

The condenser must cause a vapor-to-liquid phase change for 

periods during which the temperature of liquid in the process 

equipment is at or above its boiling or bubble point. Examples 

of process condensers include distillation condensers, reflux 

condensers, and condensers used in stripping or flashing 

operation. In a series of condensers, all condensers up to and 

including the first condenser with an exit gas temperature below 

the boiling or bubble point of the liquid in the process 

equipment are considered to be process condensers. All 

condensers in line prior to the vacuum source are included in 

this definition.

Process shutdown means a work practice or operational 

procedure that stops production from a process or part of a 

process during which it is technically feasible to clear process 

material from a process or part of a process consistent with 

safety constraints and during which repairs can be effected. An 

unscheduled work practice or operational procedure that stops 
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production from a process or part of a process for less than 24 

hours is not a process shutdown. An unscheduled work practice or 

operational procedure that would stop production from a process 

or part of a process for a shorter period of time than would be 

required to clear the process or part of the process of 

materials and start up the process, and would result in greater 

emissions than delay of repair of leaking components until the 

next scheduled process shutdown, is not a process shutdown. The 

use of spare equipment and technically feasible bypassing of 

equipment without stopping production are not process shutdowns.

Process tank means a tank that is used within a process to 

collect material discharged from a feedstock storage vessel or

equipment within the process before the material is transferred 

to other equipment within the process or a product storage 

vessel. In many process tanks, unit operations such as reactions 

and blending are conducted. Other process tanks, such as surge 

control vessels and bottom receivers, however, may not involve 

unit operations.

Process unit means the equipment assembled and connected by 

pipes or ducts to process raw materials and to manufacture an 

intended product.

Process unit group means a group of process units that 

manufacture PAI and products other than PAI by alternating raw 

materials or operating conditions, or by reconfiguring process 
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equipment. A process unit group is determined according to the 

procedures specified in §63.1360(g).

Process vent means a point of emission from processing 

equipment to the atmosphere or a control device. The vent may be 

the release point for an emission stream associated with an 

individual unit operation, or it may be the release point for 

emission streams from multiple unit operations that have been 

manifolded together into a common header. Examples of process 

vents include, but are not limited to, vents on condensers used 

for product recovery, bottom receivers, surge control vessels, 

reactors, filters, centrifuges, process tanks, and product 

dryers. A vent is not considered to be a process vent for a 

given emission episode if the undiluted and uncontrolled 

emission stream that is released through the vent contains less 

than 50 ppmv HAP, as determined through process knowledge that 

no HAP are present in the emission stream; using an engineering 

assessment as discussed in §63.1365(c)(2)(ii); from test data 

collected using Method 18 of 40 CFR part 60, appendix A; or from 

test data collected using any other test method that has been 

validated according to the procedures in Method 301 of appendix 

A of this part. Process vents do not include vents on storage 

vessels regulated under §63.1362(c), vents on wastewater 

emission sources regulated under §63.1362(d), or pieces of 

equipment regulated under §63.1363.
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Process wastewater means wastewater which, during 

manufacturing or processing, comes into direct contact with, or 

results from, the production or use of any raw material, 

intermediate product, finished product, by-product, or waste 

product. Examples include: product tank drawdown or feed tank 

drawdown; water formed during a chemical reaction or used as a 

reactant; water used to wash impurities from organic products or 

reactants; water used to clean process equipment; water used to 

cool or quench organic vapor streams through direct contact; and 

condensed steam from jet ejector systems pulling vacuum on 

vessels containing organics.

Product means the compound(s) or chemical(s) that are 

produced or manufactured as the intended output of a process 

unit. Impurities and wastes are not considered products.

Product dryer means equipment that is used to remove 

moisture or other liquid from granular, powdered, or other solid 

PAI or integral intermediate products prior to storage, 

formulation, shipment, or other uses. The product dryer is part 

of the process.

Product dryer vent means a process vent from a product 

dryer through which a gas stream containing gaseous pollutants 

(i.e., organic HAP, HCl, or chlorine), particulate matter, or 

both are released to the atmosphere or are routed to a control 

device.
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Production-indexed HAP consumption factor (HAP factor) is 

the result of dividing the annual consumption of total HAP by 

the annual production rate, per process.

Production-indexed VOC consumption factor (VOC factor) is 

the result of dividing the annual consumption of total VOC by 

the annual production rate, per process.

Publicly owned treatment works (POTW) is defined at 40 CFR 

part 403.3(0).

Reactor means a device or vessel in which one or more 

chemicals or reactants, other than air, are combined or 

decomposed in such a way that their molecular structures are 

altered and one or more new organic compounds are formed.

Reconfiguration means disassembly of processing equipment 

for a particular non-dedicated process unit and reassembly of 

that processing equipment in a different sequence, or in 

combination with other equipment, to create a different nondedicated process unit.

Reconstruction, as used in §63.1360(b), shall have the 

meaning given in §63.2, except that “affected or previously 

unaffected stationary source” shall mean either “affected 

facility” or “PAI process unit.”

Recovery device, as used in the wastewater provisions, 

means an individual unit of equipment capable of, and normally 

used for the purpose of, recovering chemicals for fuel value 
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(i.e., net positive heating value), use, reuse, or for sale for 

fuel value, use, or reuse. Examples of equipment that may be 

recovery devices include organic removal devices such as 

decanters, strippers, or thin-film evaporation units. To be a 

recovery device, a decanter and any other equipment based on the 

operating principle of gravity separation must receive only 

multi-phase liquid streams.

Repaired means that equipment is adjusted, or otherwise 

altered, to eliminate a leak as defined in the applicable 

paragraphs of §63.1363.

Research and development facility means any stationary 

source whose primary purpose is to conduct research and 

development, where the operations are under the close 

supervision of technically trained personnel, and is not engaged 

in the manufacture of products for commercial sale, except in a 

de minimis manner.

Residual means any liquid or solid material containing 

Table 9 compounds (as defined in §63.111 of subpart G of this 

part) that is removed from a wastewater stream by a waste 

management unit or treatment process that does not destroy 

organics (nondestructive unit). Examples of residuals from 

nondestructive wastewater management units include the organic 

layer and bottom residue removed by a decanter or organic-water 

separator and the overheads from a steam stripper or air 
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stripper. Examples of materials which are not residuals include: 

silt; mud; leaves; bottoms from a steam stripper or air 

stripper; and sludges, ash, or other materials removed from 

wastewater being treated by destructive devices such as 

biological treatment units and incinerators.

Safety device means a closure device such as a pressure 

relief valve, frangible disc, fusible plug, or any other type of 

device which functions exclusively to prevent physical damage or 

permanent deformation to a unit or its air emission control 

equipment by venting gases or vapors directly to the atmosphere 

during unsafe conditions resulting from an unplanned, 

accidental, or emergency event. For the purposes of this 

subpart, a safety device is not used for routine venting of 

gases or vapors from the vapor headspace underneath a cover such 

as during filling of the unit or to adjust the pressure in this 

vapor headspace in response to normal daily diurnal ambient 

temperature fluctuations. A safety device is designed to remain 

in a closed position during normal operations and open only when 

the internal pressure, or another relevant parameter, exceeds 

the device threshold setting applicable to the air emission 

control equipment as determined by the owner or operator based 

on manufacturer recommendations, applicable regulations, fire 

protection and prevention codes, standard engineering codes and 

practices, or other requirements for the safe handling of 
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flammable, combustible, explosive, reactive, or hazardous 

materials.

Sampling connection system means an assembly of equipment 

within a process unit used during periods of representative 

operation to take samples of the process fluid. Equipment used 

to take nonroutine grab samples is not considered a sampling 

connection system.

Sensor means a device that measures a physical quantity or 

the change in a physical quantity, such as temperature, 

pressure, flow rate, pH, or liquid level.

Set pressure means the pressure at which a properly 

operating pressure relief device begins to open to relieve 

atypical process system operating pressure.

Sewer line means a lateral, trunk line, branch line, or 

other conduit including, but not limited to, grates, trenches, 

etc., used to convey wastewater streams or residuals to a 

downstream waste management unit.

Shutdown means the cessation of operation of a continuous 

PAI process unit for any purpose. Shutdown also means the 

cessation of a batch PAI process unit or any related individual 

piece of equipment required or used to comply with this part or 

for emptying and degassing storage vessels for periodic 

maintenance, replacement of equipment, repair, or any other 

purpose not excluded from this definition. Shutdown does not 
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apply to cessation of a batch PAI process unit at the end of a 

campaign or between batches (e.g., for rinsing or washing 

equipment), for routine maintenance, or for other routine 

operations.

Small control device means a control device that controls 

process vents, and the total HAP emissions into the control 

device from all sources are less than 10 tons of HAP per year.

Startup means the setting in operation of a continuous PAI 

process unit for any purpose, the first time a new or 

reconstructed batch PAI process unit begins production, or, for 

new equipment added, including equipment used to comply with 

this subpart, the first time the equipment is put into 

operation. For batch process units, startup does not apply to 

the first time the equipment is put into operation at the start 

of a campaign to produce a product that has been produced in the 

past, after a shutdown for maintenance, or when the equipment is 

put into operation as part of a batch within a campaign. As used 

in §63.1363, startup means the setting in operation of a piece 

of equipment or a control device that is subject to this 

subpart.

Storage vessel means a tank or other vessel that is used to 

store organic liquids that contain one or more HAP and that has 

been assigned, according to the procedures in §63.1360(f) or 

(g), to a PAI process unit that is subject to this subpart MMM. 
Page 51 of 267

The following are not considered storage vessels for the 

purposes of this subpart:

(1) Vessels permanently attached to motor vehicles such as 

trucks, railcars, barges, or ships;

(2) Pressure vessels designed to operate in excess of 204.9 

kilopascals and without emissions to the atmosphere;

(3) Vessels storing material that contains no organic HAP 

or contains organic HAP only as impurities;

(4) Wastewater storage tanks;

(5) Process tanks; and

(6) Nonwastewater waste tanks.

Supplemental gases means any nonaffected gaseous streams 

(streams that are not from process vents, storage vessels, 

equipment or waste management units) that contain less than 50 

ppmv TOC and less than 50 ppmv total HCl and chlorine, as 

determined through process knowledge, and are combined with an 

affected vent stream. Supplemental gases are often used to 

maintain pressures in manifolds or for fire and explosion 

protection and prevention. Air required to operate combustion 

device burner(s) is not considered a supplemental gas.

Surface impoundment means a waste management unit which is 

a natural topographic depression, manmade excavation, or diked 

area formed primarily of earthen materials (although it may be 

lined with manmade materials), which is designed to hold an 
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accumulation of liquid wastes or waste containing free liquids. 

A surface impoundment is used for the purpose of treating, 

storing, or disposing of wastewater or residuals, and is not an 

injection well. Examples of surface impoundments are 

equalization, settling, and aeration pits, ponds, and lagoons.

Total organic compounds (TOC) means those compounds 

measured according to the procedures of Method 18 or Method 25A, 

40 CFR part 60, appendix A.

Treatment process means a specific technique that removes 

or destroys the organics in a wastewater or residual stream such 

as a steam stripping unit, thin-film evaporation unit, waste 

incinerator, biological treatment unit, or any other process

applied to wastewater streams or residuals to comply with 

§63.138 of subpart G of this part. Most treatment processes are 

conducted in tanks. Treatment processes are a subset of waste 

management units.

Uncontrolled HAP emissions means a gas stream containing 

HAP which has exited the process (or process condenser, if any), 

but which has not yet been introduced into an air pollution 

control device to reduce the mass of HAP in the stream. If the 

process vent is not routed to an air pollution control device, 

uncontrolled emissions are those HAP emissions released to the 

atmosphere.
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Unit operation means those processing steps that occur 

within distinct equipment that are used, among other things, to 

prepare reactants, facilitate reactions, separate and purify 

products, and recycle materials. Equipment used for these 

purposes includes, but is not limited to, reactors, distillation 

units, extraction columns, absorbers, decanters, dryers, 

condensers, and filtration equipment.

Vapor-mounted seal means a continuous seal that completely 

covers the annular space between the wall of the storage tank or 

waste management unit and the edge of the floating roof, and is 

mounted such that there is a vapor space between the stored 

liquid and the bottom of the seal.

Volatile organic compounds are defined in 40 CFR 51.100.

Waste management unit means the equipment, structure(s), 

and/or device(s) used to convey, store, treat, or dispose of 

wastewater streams or residuals. Examples of waste management 

units include wastewater tanks, surface impoundments, individual 

drain systems, and biological wastewater treatment units. 

Examples of equipment that may be waste management units include 

containers, air flotation units, oil-water separators or 

organic-water separators, or organic removal devices such as 

decanters, strippers, or thin-film evaporation units. If such 

equipment is a recovery device, then it is part of a PAI process 

unit and is not a waste management unit.
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Wastewater means water that meets either of the conditions 

described in paragraph (1) or (2) of this definition and is 

discarded from a PAI process unit that is at an affected source:

(1) Is generated from a PAI process or a scrubber used to 

control emissions from a PAI process and contains either:

(i) An annual average concentration of compounds in Table 9 

of subpart G of this part of at least 5 ppmw and has an average 

flow rate of 0.02 L/min or greater; or

(ii) An annual average concentration of compounds in Table 

9 of subpart G of this part of at least 10,000 ppmw at any flow 

rate;

(2) Is generated from a PAI process unit as a result of 

maintenance activities and contains at least 5.3 Mg of compounds 

listed in Table 9 of subpart G of this part per individual 

discharge event.

Wastewater tank means a stationary waste management unit 

that is designed to contain an accumulation of wastewater or 

residuals and is constructed primarily of nonearthen materials 

(e.g., wood, concrete, steel, plastic) which provide structural 

support. Wastewater tanks used for flow equalization are 

included in this definition.

Water seal controls means a seal pot, p-leg trap, or other 

type of trap filled with water (e.g., flooded sewers that 

maintain water levels adequate to prevent air flow through the 
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system) that creates a water barrier between the sewer line and 

the atmosphere. The water level of the seal must be maintained 

in the vertical leg of a drain in order to be considered a water 

seal.

§63.1362 Standards.

(a) On and after the compliance dates specified in 

§63.1364, each owner or operator of an affected source subject 

to the provisions of this subpart shall control HAP emissions to 

the levels specified in this section and in §63.1363, as 

summarized in Table 2 of this subpart.

(b) Process vents. (1) The owner or operator of an existing 

source shall comply with the requirements of paragraphs (b)(2) 

and (3) of this section. The owner or operator of a new source 

shall comply with the requirements of paragraphs (b)(4) and (5) 

of this section. Compliance with paragraphs (b)(2) through 

(b)(5) of this section shall be demonstrated through the 

applicable test methods and initial compliance procedures in 

§63.1365 and the monitoring requirements in §63.1366.

(2) Organic HAP emissions from existing sources. The owner 

or operator of an existing affected source must comply with the 

requirements in either paragraph (b)(2)(i) of this section or 

with the requirements in paragraphs (b)(2)(ii) through (iv) of 

this section.
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(i) The uncontrolled organic HAP emission rate shall not 

exceed 0.15 Mg/yr from the sum of all process vents within a 

process.

(ii) (A) Except as provided in paragraph (b)(2)(ii)(B) of 

this section, uncontrolled organic HAP emissions from a process 

vent shall be reduced by 98 percent by weight or greater if the 

flow-weighted average flowrate for the vent as calculated using 

Equation 1 of this subpart is less than or equal to the flowrate 

calculated using Equation 2 of this subpart.

Where:

FRa = flow-weighted average flowrate for the vent, scfm

Di = duration of each emission event, min

FRi = flowrate of each emission event, scfm

n = number of emission events

FR = flowrate, scfm

HL = annual uncontrolled organic HAP emissions, lb/yr, as 

defined in §63.1361

(B) If the owner or operator can demonstrate that a control 

device, installed on or before November 10, 1997 on a process 

vent otherwise subject to the requirements of paragraph 

(b)(2)(ii)(A) of this section, reduces inlet emissions of total 
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organic HAP by greater than or equal to 90 percent by weight but 

less than 98 percent by weight, then the control device must be 

operated to reduce inlet emissions of total organic HAP by 90 

percent by weight or greater.

(iii) Excluding process vents that are subject to the 

requirements in paragraph (b)(2)(ii) of this section, 

uncontrolled organic HAP emissions from the sum of all process 

vents within a process shall be reduced by 90 percent or greater 

by weight.

(iv) As an alternative to the requirements in paragraphs 

(b)(2)(ii) and (iii) of this section, uncontrolled organic HAP 

emissions from any process vent may be reduced in accordance 

with any of the provisions in paragraphs (b)(2)(iv)(A) through 

(D) of this section. All remaining process vents within a 

process must be controlled in accordance with paragraphs 

(b)(2)(ii) and (iii) of this section.

(A) To outlet concentrations less than or equal to 20 ppmv; 

or

(B) By a flare that meets the requirements of §63.11(b); or

(C) By a control device specified in §63.1365(a)(4); or

(D) In accordance with the alternative standard specified 

in paragraph (b)(6) of this section.

(3) HCl and Cl2 emissions from existing sources. For each 

process, the owner or operator of an existing source shall 
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comply with the requirements of either paragraph (b)(3)(i) or 

(ii) of this section.

(i) The uncontrolled HCl and Cl2 emissions, including HCl 

generated from the combustion of halogenated process vent 

emissions, from the sum of all process vents within a process 

shall not exceed 6.8 Mg/yr.

(ii) HCl and Cl2 emissions, including HCl generated from 

combustion of halogenated process vent emissions, from the sum 

of all process vents within a process shall be reduced by 94 

percent or greater or to outlet concentrations less than or 

equal to 20 ppmv.

(4) Organic HAP emissions from new sources. For each 

process, the owner or operator of a new source shall comply with 

the requirements of either paragraph (b)(4)(i) or (ii) of this 

section.

(i) The uncontrolled organic HAP emissions shall not exceed 

0.15 Mg/yr from the sum of all process vents within a process.

(ii) The uncontrolled organic HAP emissions from the sum of 

all process vents within a process at a new affected source that 

are not controlled according to any of the requirements of 

paragraphs (b)(4)(ii)(A) through (C) or (b)(6) of this section 

shall be reduced by 98 weight percent or greater.

(A) To outlet concentrations less than or equal to 20 ppmv; 

or
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(B) By a flare that meets the requirements of §63.11(b); or

(C) By a control device specified in §63.1365(a)(4).

(5) HCl and Cl2 emissions from new sources. For each 

process, the owner or operator of a new source shall comply with 

the requirements of either paragraph (b)(5)(i), (ii), or (iii) 

of this section.

(i) The uncontrolled HCl and Cl2 emissions, including HCl 

generated from combustion of halogenated process vent emissions, 

from the sum of all process vents within a process shall not 

exceed 6.8 Mg/yr.

(ii) If HCl and Cl2 emissions, including HCl generated from 

combustion of halogenated process vent emissions, from the sum 

of all process vents within a process are greater than 6.8 Mg/yr

and less than or equal to 191 Mg/yr, these HCl and Cl2 emissions 

shall be reduced by 94 percent or to an outlet concentration 

less than or equal to 20 ppmv.

(iii) If HCl and Cl2 emissions, including HCl generated from 

combustion of halogenated process vent emissions, from the sum 

of all process vents within a process are greater than 191 

Mg/yr, these HCl and Cl2 emissions shall be reduced by 99 percent 

or greater or to an outlet concentration less than or equal to 

20 ppmv.

(6) Alternative standard. As an alternative to the 

provisions in paragraphs (b)(2) through (5) of this section, the 
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owner or operator may route emissions from a process vent to a 

combustion control device achieving an outlet TOC concentration, 

as calibrated on methane or the predominant HAP, of 20 ppmv or 

less, and an outlet concentration of HCl and Cl2 of 20 ppmv or 

less. If the owner or operator is routing emissions to a noncombustion control device or series of control devices, the 

control device(s) must achieve an outlet TOC concentration, as 

calibrated on methane or the predominant HAP, of 50 ppmv or 

less, and an outlet concentration of HCl and Cl2 of 50 ppmv or 

less. Any process vents within a process that are not routed to 

such a control device or series of control devices must be 

controlled in accordance with the provisions of paragraph 

(b)(2)(ii), (iii), (iv), (b)(3)(ii), (b)(4)(ii), (b)(5)(ii) or 

(iii) of this section, as applicable.

(c) Storage vessels. (1) The owner or operator shall either 

determine the group status of a storage vessel or designate it 

as a Group 1 storage vessel. If the owner or operator elects to 

designate the storage vessel as a Group 1 storage vessel, the 

owner or operator is not required to determine the maximum true 

vapor pressure of the material stored in the storage vessel.

(2) Standard for existing sources. Except as specified in 

paragraphs (c)(4), (5), and (6) of this section, the owner or 

operator of a Group 1 storage vessel at an existing affected 
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source, as defined in §63.1361, shall equip the affected storage 

vessel with one of the following:

(i) A fixed roof and internal floating roof, or

(ii) An external floating roof, or

(iii) An external floating roof converted to an internal 

floating roof, or

(iv) A closed vent system meeting the conditions of 

paragraph (j) of this section and a control device that meets 

any of the following conditions:

(A) Reduces organic HAP emissions by 95 percent by weight 

or greater; or

(B) Reduces organic HAP emissions to outlet concentrations 

of 20 ppmv or less; or

(C) Is a flare that meets the requirements of §63.11(b); or

(D) Is a control device specified in §63.1365(a)(4).

(3) Standard for new sources. Except as specified in 

paragraphs (c)(4), (5), and (6) of this section, the owner or 

operator of a Group 1 storage vessel at a new source, as defined 

in §63.1361, shall equip the affected storage vessel in 

accordance with any one of paragraphs (c)(2)(i) through (iv) of 

this section.

(4) Alternative standard. As an alternative to the 

provisions in paragraphs (c)(2) and (3) of this section, the 

owner or operator of an existing or new affected source may 
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route emissions from storage vessels to a combustion control 

device achieving an outlet TOC concentration, as calibrated on 

methane or the predominant HAP, of 20 ppmv or less, and an 

outlet concentration of hydrogen chloride and chlorine of 20 

ppmv or less. If the owner or operator is routing emissions to a 

non-combustion control device or series of control devices, the 

control device(s) must achieve an outlet TOC concentration, as 

calibrated on methane or the predominant HAP, of 50 ppmv or 

less, and an outlet concentration of HCl and Cl2 of 50 ppmv or 

less.

(5) Planned routine maintenance. The owner or operator is 

exempt from the specifications in paragraphs (c)(2) through (4) 

of this section during periods of planned routine maintenance of 

the control device that do not exceed 240 hr/yr. The owner or 

operator may submit an application to the Administrator 

requesting an extension of this time limit to a total of 360 

hr/yr. The application must explain why the extension is needed, 

it must indicate that no material will be added to the storage 

vessel between the time the 240-hr limit is exceeded and the 

control device is again operational, and it must be submitted at 

least 60 days before the 240-hr limit will be exceeded.

(6) Vapor balancing alternative. As an alternative to the 

requirements in paragraphs (c)(2) and (3) of this section, the 

owner or operator of an existing or new affected source may 
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implement vapor balancing in accordance with paragraphs 

(c)(6)(i) through (vii) of this section.

(i) The vapor balancing system must be designed and 

operated to route organic HAP vapors displaced from loading of 

the storage tank to the railcar or tank truck from which the 

storage tank is filled.

(ii) Tank trucks and railcars must have a current 

certification in accordance with the U.S. Department of 

Transportation pressure test requirements of 49 CFR part 180 for 

tank trucks and 49 CFR 173.31 for railcars.

(iii) Hazardous air pollutants must only be unloaded from 

tank trucks or railcars when vapor collection systems are 

connected to the storage tank's vapor collection system.

(iv) No pressure relief device on the storage tank or on 

the railcar or tank truck shall open during loading or as a 

result of diurnal temperature changes (breathing losses).

(v) Pressure relief devices on affected storage tanks must 

be set to no less than 2.5 psig at all times to prevent 

breathing losses. The owner or operator shall record the setting 

as specified in §63.1367(b)(8) and comply with the following 

requirements for each pressure relief valve:

(A) The pressure relief valve shall be monitored quarterly 

using the method described in §63.180(b).
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(B) An instrument reading of 500 ppmv or greater defines a 

leak.

(C) When a leak is detected, it shall be repaired as soon 

as practicable, but no later than 5 days after it is detected, 

and the owner or operator shall comply with the recordkeeping 

requirements of §63.1363(g)(4)(i) through (iv).

(vi) Railcars or tank trucks that deliver HAP to an 

affected storage tank must be reloaded or cleaned at a facility 

that utilizes one of the following control techniques:

(A) The railcar or tank truck must be connected to a closed 

vent system with a control device that reduces inlet emissions 

of HAP by 90 percent by weight or greater; or

(B) A vapor balancing system designed and operated to 

collect organic HAP vapor displaced from the tank truck or 

railcar during reloading must be used to route the collected HAP 

vapor to the storage tank from which the liquid being 

transferred originated.

(vii) The owner or operator of the facility where the 

railcar or tank truck is reloaded or cleaned must comply with 

the following requirements:

(A) Submit to the owner or operator of the affected storage 

tank and to the Administrator a written certification that the 

reloading or cleaning facility will meet the requirements of 

this section. The certifying entity may revoke the written 
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certification by sending a written statement to the owner or 

operator of the affected storage tank giving at least 90 days 

notice that the certifying entity is rescinding acceptance of 

responsibility for compliance with the requirements of this 

paragraph (c)(6)(vii)(A).

(B) If complying with paragraph (c)(6)(vi)(A) of this 

section, demonstrate initial compliance in accordance with 

§63.1365(d), demonstrate continuous compliance in accordance 

with §63.1366, keep records as specified in §63.1367, and 

prepare reports as specified in §63.1368.

(C) If complying with paragraph (c)(6)(vi)(B) of this 

section, keep records of:

(1) The equipment to be used and the procedures to be 

followed when reloading the railcar or tank truck and displacing 

vapors to the storage tank from which the liquid originates, and

(2) Each time the vapor balancing system is used to comply 

with paragraph (c)(6)(vi)(B) of this section.

(7) Compliance with the provisions of paragraphs (c)(2) and 

(3) of this section is demonstrated using the initial compliance 

procedures in §63.1365(d) and the monitoring requirements in 

§63.1366. Compliance with the outlet concentrations in paragraph 

(c)(4) of this section shall be determined by the initial 

compliance provisions in §63.1365(a)(5) and the continuous 

emission monitoring requirements of §63.1366(b)(5).
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(d) Wastewater. The owner or operator of each affected 

source shall comply with the requirements of §§63.132 through 

63.147, with the differences noted in paragraphs (d)(1) through 

(16) of this section for the purposes of this subpart.

(1) When the determination of equivalence criteria in 

§63.102(b) is referred to in §§63.132, 63.133, and 63.137 of 

subpart G of this part, the provisions in §63.6(g) of subpart A 

of this part shall apply.

(2) When the storage tank requirements contained in 

§§63.119 through 63.123 are referred to in §§63.132 through 

63.147, §§63.119 through 63.123 are applicable, with the 

exception of the differences noted in paragraphs (d)(2)(i) 

through (iv) of this section.

(i) When the term “storage vessel” is used in §§63.119 

through 63.123 of subpart G of this part, the definition of the 

term “storage vessel” in §63.1361 shall apply for the purposes 

of this subpart.

(ii) When December 31, 1992, is referred to in §63.119 of 

subpart G of this part, November 10, 1997 shall apply for the 

purposes of this subpart.

(iii) When April 22, 1994 is referred to in §63.119 of 

subpart G of this part, June 23, 1999 shall apply for the 

purposes of this subpart.
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(iv) When the phrase “the compliance date specified in 

§63.100 of subpart F of this part” is referred to in §63.120 of 

subpart G of this part, the phrase “the compliance date 

specified in §63.1364” shall apply for the purposes of this 

subpart.

(3) To request approval to monitor alternative parameters, 

as referred to in §63.146(a) of subpart G of this part, the 

owner or operator shall comply with the procedures in §63.8(f) 

of subpart A of this part, as referred to in §63.1366(b)(4), 

instead of the procedures in §63.151(f) or (g) of subpart G of 

this part.

(4) When the Notification of Compliance Status report 

requirements contained in §63.152(b) of subpart G of this part 

are referred to in §63.146 of subpart G of this part, the 

Notification of Compliance Status report requirements in 

§63.1368(f) shall apply for the purposes of this subpart.

(5) When the recordkeeping requirements contained in 

§63.152(f) of subpart G of this part are referred to in 

§63.147(d) of subpart G of this part, the recordkeeping 

requirements in §63.1367 shall apply for the purposes of this 

subpart.

(6) When the Periodic report requirements contained in 

§63.152(c) of subpart G of this part are referred to in §§63.146 

and 63.147 of subpart G of this part, the Periodic report 
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requirements contained in §63.1368(g) shall apply for the 

purposes of this subpart.

(7) When the term “process wastewater” is referred to in 

§§63.132 through 63.147 of subpart G of this part, the term 

“wastewater” as defined in §63.1361 shall apply for the purposes 

of this subpart.

(8) When the term “Group 1 wastewater stream” is used in 

§§63.132 through 63.147 of subpart G of this part, the 

definition of the term “Group 1 wastewater stream” in §63.1361 

shall apply for both new sources and existing sources for the 

purposes of this subpart.

(9) The requirements in §§63.132 through 63.147 for 

compounds listed on Table 8 of subpart G of this part shall not 

apply for the purposes of this subpart.

(10) When the total load of Table 9 compounds in the sum of 

all process wastewater from PAI process units at a new affected 

source is 2,100 Mg/yr (2,300 tons/yr) or more, the owner or 

operator shall reduce, by removal or destruction, the mass flow 

rate of all compounds in Table 9 of subpart G of this part in 

all wastewater (process and maintenance wastewater) by 99 

percent or more. Alternatively, the owner or operator may treat 

the wastewater in a unit identified in and complying with 

§63.138(h) of subpart G of this part. The removal/destruction 

efficiency shall be determined by the procedures specified in 
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§63.145(c) of subpart G of this part, for noncombustion 

processes, or §63.145(d) of subpart G of this part, for 

combustion processes.

(11) The compliance date for the affected source subject to 

the provisions of this section is specified in §63.1364.

(12) As an alternative to using Method 18 of 40 CFR part 

60, as specified in §§63.139(c)(1)(ii) and 63.145(i)(2), the 

owner or operator may elect to use Method 25 or Method 25A of 40 

CFR part 60, as specified in §63.1365(b).

(13) The requirement to correct outlet concentrations from 

combustion devices to 3 percent oxygen in §63.139(c)(1)(ii) 

shall apply only if supplemental gases are combined with 

affected vent streams, and the procedures in §63.1365(a)(7)(i) 

apply instead of the procedures in §63.145(i)(6) to determine 

the percent oxygen correction. If emissions are controlled with 

a vapor recovery system as specified in §63.139(c)(2), the owner 

or operator must correct for supplemental gases as specified in 

§63.1365(a)(7)(ii).

(14) As an alternative to the management and treatment 

options specified in §63.132(g)(2), any Group 1 wastewater 

stream (or residual removed from a Group 1 wastewater stream) 

that contains less than 50 ppmw of HAP listed in Table 2 to 

subpart GGG of this part may be transferred offsite or to an onsite treatment operation not owned or operated by the owner or 
Page 70 of 267

operator of the source generating the wastewater (or residual) 

if the transferee manages and treats the wastewater stream or 

residual in accordance with paragraphs (d)(14)(i) through (iv) 

of this section.

(i) Treat the wastewater stream or residual in a biological 

treatment unit in accordance with §§63.138 and 63.145.

(ii) Cover the waste management units up to the activated 

sludge unit. Alternatively, covers are not required if the owner 

or operator demonstrates that less than 5 percent of the total 

HAP listed in Table 3 to subpart GGG of this part is emitted.

(iii) Inspect covers as specified in §63.1366(h).

(iv) The reference in §63.132(g)(2) to “§63.102(b) of 

subpart F” does not apply for the purposes of this subpart.

(15) When §63.133 refers to Table 10 to subpart G of this 

part, the maximum true vapor pressures in the table shall be 

limited to the HAP listed in Table 9 to subpart G of this part.

(16) When the inspection, recordkeeping, and reporting 

requirements contained in §63.148 are referred to in §§63.132 

through 63.147, the inspection requirements in §63.1366(h), the 

recordkeeping requirements in §63.1367(f), and the reporting 

requirements in §63.1368(g)(2)(iii) and (xi) shall apply for the 

purposes of this subpart.

(e) Bag dumps and product dryers. (1) The owner or operator 

shall reduce particulate matter emissions to a concentration not 
Page 71 of 267

to exceed 0.01 gr/dscf from product dryers that dry a PAI or 

integral intermediate that is a HAP.

(2) The owner or operator shall reduce particulate matter 

emissions to a concentration not to exceed 0.01 gr/dscf from bag 

dumps that introduce to a PAI process unit a feedstock that is a 

solid material and a HAP, excluding bag dumps where the 

feedstock contains HAP only as impurities.

(3) Gaseous HAP emissions from product dryers and bag dumps 

shall be controlled in accordance with the provisions for 

process vent emissions in paragraph (b) of this section.

(f) Heat exchange systems. Unless one or more of the 

conditions specified in §63.104(a)(1) through (6) of subpart F 

of this part are met, an owner or operator shall monitor each 

heat exchange system that is used to cool process equipment in 

PAI process units that are part of an affected source as defined 

in §63.1360(a) according to the provisions in either §63.104(b) 

or (c) of subpart F of this part. When the term “chemical 

manufacturing process unit” is used in §63.104(c) of subpart F 

of this part, the term “PAI process unit” shall apply for the 

purposes of this subpart. Whenever a leak is detected, the owner 

or operator shall comply with the requirements in §63.104(d) of 

subpart F of this part. Delay of repair of heat exchange systems 

for which leaks have been detected is allowed in accordance with 

the provisions of §63.104(e) of subpart F of this part.
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(g) Pollution prevention alternative. Except as provided in 

paragraph (g)(1) of this section, for a process that has an 

initial startup before November 10, 1997, an owner or operator 

may choose to meet the pollution prevention alternative 

requirement specified in either paragraph (g)(2) or (3) of this 

section for any PAI process unit, in lieu of the requirements 

specified in paragraphs (b), (c), (d), and (e) of this section 

and in §63.1363. Compliance with the requirements of paragraphs 

(g)(2) and (3) of this section shall be demonstrated through the 

procedures in §§63.1365(g) and 63.1366(f).

(1) A HAP must be controlled according to the requirements 

of paragraphs (b), (c), (d), and (e) of this section and 

§63.1363 if it is generated in the PAI process unit or an 

associated control device and it is not part of the productionindexed HAP consumption factor (HAP factor).

(2) The HAP factor shall be reduced by at least 85 percent 

from a 3-year average baseline beginning no earlier than the 

1987 through 1989 calendar years. Alternatively, for a process 

that has been operating for less than 3 years but more than 1 

year, the baseline factor may be calculated for the time period 

from startup of the process until the present. For any reduction 

in the HAP factor achieved by reducing a HAP that is also a VOC, 

an equivalent reduction in the production-indexed VOC 

consumption factor (VOC factor) is also required (the 
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equivalence is determined on a mass basis, not a percentage 

basis). For any reduction in the HAP factor that is achieved by 

reducing a HAP that is not a VOC, the VOC factor may not be 

increased.

(3) As an alternative to the provisions in paragraph (g)(2) 

of this section, the owner or operator may combine pollution 

prevention with emissions control as specified in paragraphs 

(g)(3)(i) and (ii) of this section.

(i) The HAP factor shall be reduced as specified in 

paragraph (g)(2) of this section except that a reduction of at 

least 50 percent shall apply for the purposes of this paragraph.

(ii) The total annual HAP emissions from the PAI process 

unit shall be reduced by an amount that, when divided by the 

annual production rate and added to the reduction of the HAP 

factor yields a value of at least 85 percent of the baseline HAP 

factor. The total annual VOC emissions from the process unit 

must be reduced by an amount equivalent to the reduction in HAP 

emissions for each HAP that is a VOC (the equivalence is 

determined on a mass basis). For HAP emissions reductions that 

are achieved by reducing a HAP that is not a VOC, the total 

annual VOC emissions may not be increased. The reduction in HAP 

air emissions must be achieved using one of the following 

control devices:
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(A) Combustion control devices such as incinerators, 

flares, or process heaters.

(B) Control devices such as condensers and carbon adsorbers 

whose recovered product is destroyed or shipped offsite for 

destruction.

(C) Any control device that does not ultimately allow for 

recycling of material back to the PAI process unit.

(D) Any control device for which the owner or operator can 

demonstrate that the use of the device in controlling HAP 

emissions will have no effect on the HAP factor for the PAI 

process unit.

(h) Emissions averaging provisions. Except as provided in 

paragraphs (h)(1) through (7) of this section, the owner or 

operator of an existing affected facility may choose to comply 

with the emission standards in paragraphs (b), (c), and (d) of 

this section by using emissions averaging procedures specified 

in §63.1365(h) for organic HAP emissions from any storage 

vessel, process, or waste management unit that is part of an 

affected source subject to this subpart.

(1) A State may restrict the owner or operator of an 

existing source to use only the procedures in paragraphs (b), 

(c), and (d) of this section to comply with the emission 

standards where State authorities prohibit averaging of HAP 

emissions.
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(2) Group 1 emission points that are controlled as 

specified in paragraphs (h)(2)(i) through (iii) of this section 

may not be used to calculate emissions averaging credits, unless 

the equipment is approved for use in a different manner from 

that specified in paragraphs (b) through (d) of this section, 

and a nominal efficiency has been assigned according to the 

procedures in §63.150(i). The nominal efficiency must exceed the 

percent reduction required by paragraphs (b) and (c) of this 

section for process vents and storage vessels, respectively, 

exceed the percent reduction required in §63.139(c) for control 

devices used to control emissions vented from waste management 

units, and exceed the percent reduction required in §63.138(e) 

or (f) for wastewater treatment processes.

(i) Storage vessels controlled with an internal floating 

roof meeting the specifications of §63.119(b), an external 

floating roof meeting the specifications of §63.119(c), or an 

external floating roof converted to an internal floating meeting 

the specifications of §63.119(d).

(ii) Emission points controlled with a flare.

(iii) Wastewater streams that are managed in waste 

management units that are controlled as specified in §§63.133 

through 63.137, treated using a steam stripper meeting the 

specifications of §63.138(d), and emissions from the steam 
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stripper are controlled in a control device that meets the 

percent reduction requirements specified in §63.139(c).

(3) Process vents and storage vessels controlled with a 

control device to an outlet concentration of 20 ppmv or 50 ppmv, 

as specified in paragraph (b)(2)(iv)(A), (b)(3)(ii), (b)(6), 

(c)(2)(iv)(B), or (c)(4) of this section, and wastewater streams 

controlled in a treatment unit to an outlet concentration of 50 

ppmw, may not be used in any averaging group.

(4) Maintenance wastewater streams, wastewater streams 

treated in biological treatment units, and Group 2 wastewater 

streams that are not managed as specified in §§63.133 through 

63.137 may not be included in any averaging group.

(5) Processes which have been permanently shut down and 

storage vessels permanently taken out of HAP service may not be 

included in any averaging group.

(6) Emission points already controlled on or before 

November 15, 1990 may not be used to generate emissions 

averaging credits, unless the level of control has been 

increased after November 15, 1990. In these cases, credit will 

be allowed only for the increase in control after November 15, 

1990.

(7) Emission points controlled to comply with a State or 

Federal rule other than this subpart may not be included in an 

emissions averaging group, unless the level of control has been 
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increased after November 15, 1990, above what is required by the 

other State or Federal rule. Only the control above what is 

required by the other State or Federal rule will be credited. 

However, if an emission point has been used to generate 

emissions averaging credit in an approved emissions average, and 

the point is subsequently made subject to a State or Federal 

rule other than this subpart, the point can continue to generate 

emissions averaging credit for the purpose of complying with the 

previously approved average.

(i) Opening of a safety device. The owner or operator that 

opensOpening of a safety device, as defined in §63.1361, is not 

exempt from applicable standards in order to avoid unsafe 

conditions. If opening a safety device results in the failure to 

meet any applicable standard, the owner or operator must still 

comply with the general duty to minimize emissions. If opening a 

safety device results in a deviation or excess emissions, such 

events must be reported as specified in §63.1368(i). If the 

owner or operator attributes the event to a malfunction and 

intends to assert an affirmative defense, the owner or operator 

is subject to §63.1360(k).allowed at any time conditions require 

it to avoid unsafe conditions.

(j) Closed-vent systems. The owner or operator of a closedvent system that contains bypass lines that could divert a vent 

stream away from a control device used to comply with the 
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requirements in paragraphs (b) through (d) of this section shall 

comply with the requirements of Table 3 of this subpart and 

paragraph (j)(1) or (2) of this section. Equipment such as low 

leg drains, high point bleeds, analyzer vents, open-ended valves 

or lines, rupture disks and pressure relief valves needed for 

safety purposes are not subject to this paragraph.

(1) Install, calibrate, maintain, and operate a flow 

indicator that is capable of determining whether vent stream 

flow is present and taking frequent, periodic readings. Records 

shall be maintained as specified in §63.1367(f)(1). The flow 

indicator shall be installed at the entrance to any bypass line 

that could divert the vent stream away from the control device 

to the atmosphere; or

(2) Secure the bypass line valve in the closed position 

with a car-seal or lock-and-key type configuration. Records 

shall be maintained as specified in §63.1367(f)(2).

(k) Control requirements for certain liquid streams in open 

systems within a PAI process unit. (1) The owner or operator 

shall comply with the provisions of Table 4 of this subpart, for 

each item of equipment meeting all the criteria specified in 

paragraphs (k)(2) through (4) of this section and either 

paragraph (k)(5)(i) or (ii) of this section.

(2) The item of equipment is of a type identified in Table 

4 of this subpart;
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(3) The item of equipment is part of a PAI process unit as 

defined in §63.1361;

(4) The item of equipment is controlled less stringently 

than in Table 4 of this subpart, and the item of equipment is 

not otherwise exempt from controls by the provisions of this 

subpart or subpart A of this part;

(5) The item of equipment:

(i) Is a drain, drain hub, manhole, lift station, trench, 

pipe, or oil/water separator that conveys water with a total 

annual average concentration greater than or equal to 10,000 ppm 

by weight of compounds in Table 9 of subpart G of this part at 

any flowrate; or a total annual average concentration greater 

than or equal to 1,000 ppm by weight of compounds in Table 9 of 

subpart G of this part at an annual average flow rate greater 

than or equal to 10 liters per minute; or

(ii) Is a tank that receives one or more streams that 

contain water with a total annual average concentration greater 

than or equal to 1,000 ppm by weight of compounds in Table 9 of 

subpart G of this part at an annual average flowrate greater 

than or equal to 10 liters per minute. The owner or operator of 

the source shall determine the characteristics of the stream as 

specified in paragraphs (k)(5)(ii)(A) and (B) of this section.

(A) The characteristics of the stream being received shall 

be determined at the inlet to the tank.
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(B) The characteristics shall be determined according to 

the procedures in §63.144(b) and (c) of subpart G of this part.

(l) Exemption for RCRA treatment units. An owner or 

operator shall be exempt from the initial compliance 

demonstrations and monitoring provisions in §§63.1365 and 

63.1366 and the associated recordkeeping and reporting 

requirements in §§63.1367 and 63.1368 for emissions from process 

vents, storage vessels, and waste management units that are 

discharged to the following devices:

(1) A boiler or process heater burning hazardous waste for 

which the owner or operator:

(i) Has been issued a final permit under 40 CFR part 270 

and complies with the requirements of 40 CFR part 266, subpart 

H; or

(ii) Has certified compliance with the interim status 

requirements of 40 CFR part 266, subpart H.

(2) A hazardous waste incinerator for which the owner or 

operator has been issued a final permit under 40 CFR part 270 

and complies with the requirements of 40 CFR part 264, subpart 

O, or has certified compliance with the interim status 

requirements of 40 CFR part 265, subpart O.

§63.1363 Standards for equipment leaks.

(a) General equipment leak requirements. (1) The provisions 

of this section apply to “equipment” as defined in §63.1361. The 
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provisions of this section also apply to any closed-vent systems 

and control devices required by this section.

(2) Consistency with other regulations. After the 

compliance date for a process, equipment subject to both this 

section and either of the following will be required to comply 

only with the provisions of this subpart:

(i) 40 CFR part 60.

(ii) 40 CFR part 61.

(3) [Reserved]

(4) The provisions in §63.1(a)(3) of subpart A of this part 

do not alter the provisions in paragraph (a)(2) of this section.

(5) Lines and equipment not containing process fluids are 

not subject to the provisions of this section. Utilities, and 

other nonprocess lines, such as heating and cooling systems 

which do not combine their materials with those in the processes 

they serve, are not considered to be part of a process.

(6) The provisions of this section do not apply to benchscale processes, regardless of whether the processes are located 

at the same plant site as a process subject to the provisions of 

this subpart MMM.

(7) Each piece of equipment to which this section applies 

shall be identified such that it can be distinguished readily 

from equipment that is not subject to this section. 

Identification of the equipment does not require physical 
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tagging of the equipment. For example, the equipment may be 

identified on a plant site plan, in log entries, or by 

designation of process boundaries by some form of weatherproof 

identification. If changes are made to the affected source 

subject to the leak detection requirements, equipment 

identification for each type of component shall be updated, if 

needed, within 15 calendar days of the end of each monitoring 

period for that component.

(8) Equipment that is in vacuum service is excluded from 

the requirements of this section.

(9) Equipment that is in organic HAP service, but is in 

such service less than 300 hours per calendar year, is excluded 

from the requirements of this section if it is identified as 

required in paragraph (g)(9) of this section.

(10) When each leak is detected by visual, audible, or 

olfactory means, or by monitoring as described in §63.180(b) or 

(c) of subpart H of this part, the following requirements apply:

(i) A weatherproof and readily visible identification, 

marked with the equipment identification number, shall be 

attached to the leaking equipment.

(ii) The identification on a valve in light liquid or 

gas/vapor service may be removed after it has been monitored as 

specified in paragraph (e)(7)(iii) of this section, and no leak 

has been detected during the follow-up monitoring. If an owner 
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or operator elects to comply with §63.174(c)(1)(i), the 

identification on a connector may be removed after it has been 

monitored as specified in §63.174(c)(1)(i) and no leak is 

detected during that monitoring.

(iii) The identification on equipment, except as specified 

in paragraph (a)(10)(ii) of this section, may be removed after 

it has been repaired.

(b) References. The owner or operator shall comply with the 

provisions of subpart H of this part as specified in paragraphs 

(b)(1) through (3) of this section and with paragraph (b)(4) of 

this section for pressure relief devices. When the term “process 

unit” is used in subpart H of this part, it shall mean any group 

of processes for the purposes of this subpart. Groups of 

processes as used in this subpart may be any individual process 

or combination of processes.

(1) Sections 63.160, 63.161, 63.162, 63.163, 63.167, 

63.168, 63.170, 63.173, 63.175, 63.176, 63.181, and 63.182 of 

subpart H of this part shall not apply for the purposes of this 

subpart MMM. The owner or operator shall comply with the 

provisions specified in paragraphs (b)(1)(i) through (viii) of 

this section.

(i) Sections 63.160 and 63.162 of subpart H of this part 

shall not apply, instead the owner or operator shall comply with 

paragraph (a) of this section;
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(ii) Section 63.161 of subpart H of this part shall not 

apply, instead the owner or operator shall comply with §63.1361;

(iii) Sections 63.163 and 63.173 of subpart H of this part 

shall not apply, instead the owner or operator shall comply with 

paragraph (c) of this section;

(iv) Section 63.167 of subpart H of this part shall not 

apply, instead the owner or operator shall comply with paragraph 

(d) of this section;

(v) Section 63.168 of subpart H of this part shall not 

apply, instead the owner or operator shall comply with paragraph 

(e) of this section;

(vi) Section 63.170 of subpart H of this part shall not 

apply, instead the owner or operator shall comply with 

§63.1362(b);

(vii) Section 63.181 of subpart H of this part shall not 

apply, instead the owner or operator shall comply with paragraph 

(g) of this section; and

(viii) Section 63.182 of subpart H of this part shall not 

apply, instead the owner or operator shall comply with paragraph 

(h) of this section.

(2) The owner or operator shall comply with §§63.164, 

63.165, 63.166, 63.169, 63.177, and 63.179 of subpart H of this 

part in their entirety, except that when these sections 

reference other sections of subpart H of this part, the owner or 
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operator shall comply with the revised sections as specified in 

paragraphs (b)(1), and (3), and (4) of this section. Section 

63.164 of subpart H of this part applies to compressors. Section 

63.165 of subpart H of this part applies to pressure relief 

devices in gas/vapor service. Section 63.166 of subpart H of 

this part applies to sampling connection systems. Section 63.169 

of subpart H of this part applies to: pumps, valves, connectors,

and agitators in heavy liquid service; instrumentation systems; 

and pressure relief devices in liquid service. Section 63.177 of 

subpart H of this subpart applies to general alternative means 

of emission limitation. Section 63.179 of subpart H of this part 

applies to alternative means of emission limitation for 

enclosed-vented process units.

(3) The owner or operator shall comply with §§63.171, 

63.172, 63.174, 63.178, and 63.180 of subpart H of this part 

with the differences specified in paragraphs (b)(3)(i) through 

(v) of this section.

(i) Section 63.171, Delay of repair, shall apply except 

§63.171(a) shall not apply. Delay of repair of equipment for 

which leaks have been detected is allowed if one of the 

following conditions exist:

(A) The repair is technically infeasible without a process 

shutdown. Repair of this equipment shall occur by the end of the 

next scheduled process shutdown.
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(B) The owner or operator determines that repair personnel 

would be exposed to an immediate danger if attempting to repair

without a process shutdown. Repair of this equipment shall occur 

by the end of the next scheduled process shutdown.

(ii) Section 63.172, Closed-vent systems and control 

devices, shall apply for closed-vent systems used to comply with 

this section, and for control devices used to comply with this 

section only, except:

(A) Section 63.172(k) and (l) shall not apply. The owner or 

operator shall instead comply with paragraph (f) of this 

section.

(B) Owners or operators may, instead of complying with the 

provisions of §63.172(f), design a closed-vent system to operate 

at a pressure below atmospheric pressure. The system shall be 

equipped with at least one pressure gauge or other pressure 

measurement device that can be read from a readily accessible 

location to verify that negative pressure is being maintained in 

the closed-vent system when the associated control device is 

operating.

(iii) Section 63.174, Connectors, shall apply except:

(A) Section 63.174(b), (f), (g), and (h) shall not apply. 

In place of §63.174(b), the owner or operator shall comply with 

paragraphs (b)(3)(iii)(C) through (G) of this section. In place 
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of §63.174(f), (g), and (h), the owner or operator shall comply 

with paragraph (f) of this section.

(B) Days that the connectors are not in organic HAP service 

shall not be considered part of the 3-month period in 

§63.174(c).

(C) If the percent leaking connectors in a group of 

processes was greater than or equal to 0.5 percent during the 

initial monitoring period, monitoring shall be performed once 

per year until the percent leaking connectors is less than 0.5 

percent.

(D) If the percent leaking connectors in the group of 

processes was less than 0.5 percent, but equal to or greater 

than 0.25 percent, during the last required monitoring period, 

monitoring shall be performed once every 4 years. An owner or 

operator may comply with the requirements of this paragraph by 

monitoring at least 40 percent of the connectors in the first 2 

years and the remainder of the connectors within the next 2 

years. The percent leaking connectors will be calculated for the 

total of all monitoring performed during the 4-year period.

(E) The owner or operator shall increase the monitoring 

frequency to once every 2 years for the next monitoring period 

if leaking connectors comprise at least 0.5 percent but less 

than 1.0 percent of the connectors monitored within either the 4 

years specified in paragraph (b)(3)(iii)(D) of this section, the 
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first 4 years specified in paragraph (b)(3)(iii)(G) of this 

section, or the entire 8 years specified in paragraph 

(b)(3)(iii)(G) of this section. At the end of that 2-year 

monitoring period, the owner or operator shall monitor once per 

year while the percent leaking connectors is greater than or 

equal to 0.5 percent; if the percent leaking connectors is less 

than 0.5 percent, the owner or operator may again elect to 

monitor in accordance with paragraph (b)(3)(iii)(D) or (G) of 

this section, as applicable.

(F) If an owner or operator complying with the requirements 

of paragraph (b)(3)(iii)(D) or (G) of this section for a group 

of processes determines that 1 percent or greater of the 

connectors are leaking, the owner or operator shall increase the 

monitoring frequency to one time per year. The owner or operator 

may again elect to use the provisions of paragraph 

(b)(3)(iii)(D) or (G) of this section after a monitoring period 

in which less than 0.5 percent of the connectors are determined 

to be leaking.

(G) Monitoring shall be required once every 8 years, if the 

percent leaking connectors in the group of process units was 

less than 0.25 percent during the last required monitoring 

period. An owner or operator shall monitor at least 50 percent 

of the connectors in the first 4 years and the remainder of the 

connectors within the next 4 years. If the percent leaking 
Page 89 of 267

connectors in the first 4 years is equal to or greater than 0.35 

percent, the monitoring program shall revert at that time to the 

appropriate monitoring frequency specified in paragraph 

(b)(3)(iii)(D), (E), or (F) of this section.

(iv) Section 63.178, shall apply, except as specified in 

paragraphs (b)(3)(iv)(A) and (B) of this section.

(A) Section 63.178(b), requirements for pressure testing, 

shall apply to all processes, not just batch processes.

(B) For pumps, the phrase “at the frequencies specified in 

Table 1 of this subpart” in §63.178(c)(3)(iii) shall mean 

“quarterly” for the purposes of this subpart.

(v) Section 63.180 of subpart H of this part, Test methods 

and procedures, shall apply except §63.180(b)(4)(ii)(A) through 

(C) of subpart H of this part shall not apply. Calibration gases 

shall be a mixture of methane and air at a concentration of 

approximately, but less than, 10,000 parts per million methane 

for agitators, 2,000 parts per million for pumps, and 500 parts 

per million for all other equipment, except as provided in 

§63.180(b)(4)(iii) of subpart H of this part.

(4) Requirements for pressure relief devices. Except as 

specified in paragraph (b)(4)(iv) of this section, the owner or 

operator must comply with the operating and pressure release 

requirements specified in paragraphs (b)(4)(i) and (ii) of this 

section for pressure relief devices in organic HAP gas or vapor 
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service. Except as specified in paragraph (b)(4)(iv) of this 

section, the owner or operator must also comply with the

pressure release management requirements specified in paragraph 

(b)(4)(iii) of this section for all pressure relief devices in 

organic HAP service.

(i) Operating requirements. Except during a pressure 

release event, operate each pressure relief device in organic 

HAP gas or vapor service with an instrument reading of less than 

500 ppm above background as detected by Method 21 of 40 CFR part 

60, appendix A.

(ii) Pressure release requirements. For pressure relief 

devices in organic HAP gas or vapor service, comply with 

paragraph (b)(4)(ii)(A) or (B) of this section, as applicable.

(A) If the pressure relief device does not consist of or 

include a rupture disk, conduct instrument monitoring, as 

detected by Method 21 of 40 CFR part 60, appendix A, no later 

than 5 calendar days after the pressure release to verify that 

the pressure relief device is operating with an instrument 

reading of less than 500 ppm above background, except as 

provided in §63.171.

(B) If the pressure relief device consists of or includes a 

rupture disk, install a replacement disk as soon as practicable 

after a pressure release, but no later than 5 calendar days 

after the pressure release, except as provided in §63.171.
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(iii) Pressure release management. Except as specified in 

paragraph (b)(4)(iv) of this section, pressure releases to the 

atmosphere from pressure relief devices in organic HAP service 

are prohibited, and the owner or operator must comply with the 

requirements specified in paragraphs (b)(4)(iii)(A) and (B) of 

this section for all pressure relief devices in organic HAP 

service.

(A) For each pressure relief device in organic HAP service, 

the owner or operator must equip each pressure relief device 

with a device(s) or use a monitoring system that is capable of: 

1) identifying the pressure release; 2) recording the time and 

duration of each pressure release; and 3) notifying operators 

immediately that a pressure release is occurring. The device or 

monitoring system may be either specific to the pressure relief 

device itself or may be associated with the process system or 

piping, sufficient to indicate a pressure release to the 

atmosphere. Examples of these types of devices and systems 

include, but are not limited to, a rupture disk indicator, 

magnetic sensor, motion detector on the pressure relief valve 

stem, flow monitor, or pressure monitor.

(B) If any pressure relief device in organic HAP service 

releases to atmosphere as a result of a pressure release event, 

the owner or operator must calculate the quantity of organic HAP 

released during each pressure release event and report this 
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quantity as required in paragraph (h)(3)(v) of this section. 

Calculations may be based on data from the pressure relief 

device monitoring alone or in combination with process parameter 

monitoring data and process knowledge.

(iv) Pressure relief devices routed to a control device,

process, or drain system. If a pressure relief device in organic 

HAP service is designed and operated to route all pressure 

releases through a closed vent system to a control device, 

process, or drain system, the owner or operator is not required 

to comply with paragraphs (b)(4)(i), (ii), or (iii) (if 

applicable) of this section. Both the closed vent system and 

control device (if applicable) must meet the requirements of 

§63.172. The drain system (if applicable) must meet the 

requirements of §63.136.

(c) Standards for pumps in light liquid service and 

agitators in gas/vapor service and in light liquid service. (1) 

The provisions of this section apply to each pump that is in 

light liquid service, and to each agitator in gas/vapor service 

or in light liquid service.

(2)(i) Monitoring. Each pump and agitator subject to this 

section shall be monitored quarterly to detect leaks by the 

method specified in §63.180(b), except as provided in §§63.177, 

63.178, paragraph (f) of this section, and paragraphs (c)(5) 

through (9) of this section.
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(ii) Leak definition. The instrument reading, as determined 

by the method as specified in §63.180(b) of subpart H of this 

part, that defines a leak is:

(A) For agitators, an instrument reading of 10,000 parts 

per million or greater.

(B) For pumps, an instrument reading of 2,000 parts per 

million or greater.

(iii) Visual inspections. Each pump and agitator shall be 

checked by visual inspection each calendar week for indications 

of liquids dripping from the pump or agitator seal. If there are 

indications of liquids dripping from the seal at the time of the 

weekly inspection, the owner or operator shall follow the 

procedure specified in either paragraph (c)(2)(iii)(A) or (B) of 

this section prior to the next weekly inspection.

(A) The owner or operator shall monitor the pump or 

agitator by the method specified in §63.180(b). If the 

instrument reading indicates a leak as specified in paragraph 

(c)(2)(ii) of this section, a leak is detected.

(B) The owner or operator shall eliminate the visual 

indications of liquids dripping.

(3) Repair provisions. (i) When a leak is detected pursuant 

to paragraph (c)(2)(i), (c)(2)(iii)(A), (c)(5)(iv)(A), or 

(c)(5)(vi)(B) of this section, it shall be repaired as soon as 

practicable, but not later than 15 calendar days after it is 
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detected, except as provided in paragraph (b)(3)(i) of this 

section.

(ii) A first attempt at repair shall be made no later than 

5 calendar days after the leak is detected. First attempts at 

repair include, but are not limited to, the following practices 

where practicable:

(A) Tightening of packing gland nuts.

(B) Ensuring that the seal flush is operating at design 

pressure and temperature.

(4) Calculation of percent leakers. (i) The owner or 

operator shall decide no later than the end of the first 

monitoring period what groups of processes will be developed. 

Once the owner or operator has decided, all subsequent percent 

calculations shall be made on the same basis.

(ii) If, calculated on a 1–year rolling average, 10 percent 

or more of the pumps in a group of processes (or 3 pumps in a 

group of processes with fewer than 30 pumps) leak, the owner or 

operator shall monitor each pump once per month, until the 

calculated 1–year rolling average value drops below 10 percent 

(or three pumps in a group of processes with fewer than 30 

pumps).

(iii) The number of pumps in a group of processes shall be 

the sum of all the pumps in organic HAP service, except that 

pumps found leaking in a continuous process within 1 quarter 
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after startup of the pump shall not count in the percent leaking 

pumps calculation for that one monitoring period only.

(iv) Percent leaking pumps shall be determined using 

Equation 3 of this subpart:

Where:

%PL = percent leaking pumps

PL = number of pumps found leaking as determined through 

quarterly monitoring as required in paragraphs (c)(2)(i) and 

(ii) of this section.

PT = total pumps in organic HAP service, including those 

meeting the criteria in paragraphs (c)(5) and (6) of this 

section

PS = number of pumps in a continuous process leaking within 

1 quarter of startup during the current monitoring period

(5) Exemptions. Each pump or agitator equipped with a dual 

mechanical seal system that includes a barrier fluid system and 

meets the requirements specified in paragraphs (c)(5)(i) through 

(vii) is exempt from the requirements of paragraphs (c)(1) 

through (c)(4)(iii) of this section, except as specified in 

paragraphs (c)(5)(iv)(A) and (vii) of this section.

(i) Each dual mechanical seal system is:
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(A) Operated with the barrier fluid at a pressure that is 

at all times greater than the pump/agitator stuffing box 

pressure; or

(B) Equipped with a barrier fluid degassing reservoir that 

is connected by a closed-vent system to a control device that 

complies with the requirements of paragraph (b)(3)(ii) of this 

section; or

(C) Equipped with a closed-loop system that purges the 

barrier fluid into a process stream.

(ii) The barrier fluid is not in light liquid service.

(iii) Each barrier fluid system is equipped with a sensor 

that will detect failure of the seal system, the barrier fluid 

system, or both.

(iv) Each pump/agitator is checked by visual inspection 

each calendar week for indications of liquids dripping from the 

pump/agitator seal. If there are indications of liquids dripping 

from the pump or agitator seal at the time of the weekly 

inspection, the owner or operator shall follow the procedures 

specified in either paragraph (c)(5)(iv)(A) or (B) of this 

section prior to the next required inspection.

(A) The owner or operator shall monitor the pump or 

agitator using the method specified in §63.180(b) to determine 

if there is a leak of organic HAP in the barrier fluid. If the 
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instrument reading indicates a leak, as specified in paragraph 

(c)(2)(ii) of this section, a leak is detected.

(B) The owner or operator shall eliminate the visual 

indications of liquids dripping.

(v) Each sensor as described in paragraph (c)(5)(iii) of 

this section is observed daily or is equipped with an alarm 

unless the pump is located within the boundary of an unmanned 

plant site.

(vi)(A) The owner or operator determines, based on design 

considerations and operating experience, criteria applicable to 

the presence and frequency of drips and to the sensor that 

indicate failure of the seal system, the barrier fluid system, 

or both.

(B) If indications of liquids dripping from the 

pump/agitator seal exceed the criteria established in paragraph 

(c)(5)(vi)(A) of this section, or if, based on the criteria 

established in paragraph (c)(5)(vi)(A) of this section, the 

sensor indicates failure of the seal system, the barrier fluid 

system, or both, a leak is detected.

(vii) When a leak is detected pursuant to paragraph 

(c)(5)(iv)(A) or (vi)(B) of this section, the leak must be 

repaired as specified in paragraph (c)(3) of this section.

(6) Any pump/agitator that is designed with no externally 

actuated shaft penetrating the pump/agitator housing is exempt 
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from the requirements of paragraphs (c)(1) through (3) of this 

section.

(7) Any pump/agitator equipped with a closed-vent system 

capable of capturing and transporting any leakage from the seal 

or seals back to the process or to a control device that 

complies with the requirements of paragraph (b)(3)(ii) of this 

section is exempt from the requirements of paragraphs (c)(2) 

through (5) of this section.

(8) Any pump/agitator that is located within the boundary 

of an unmanned plant site is exempt from the weekly visual 

inspection requirement of paragraphs (c)(2)(iii) and (c)(5)(iv) 

of this section, and the daily requirements of paragraph 

(c)(5)(v) of this section, provided that each pump/agitator is 

visually inspected as often as practicable and at least monthly.

(9) If more than 90 percent of the pumps in a group of 

processes meet the criteria in either paragraph (c)(5) or (6) of 

this section, the group of processes is exempt from the 

requirements of paragraph (c)(4) of this section.

(d) Standards: open-ended valves or lines. (1)(i) Each 

open-ended valve or line shall be equipped with a cap, blind 

flange, plug, or a second valve, except as provided in §63.177 

of subpart H of this part and paragraphs (d)(4) through (6) of 

this section.
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(ii) The cap, blind flange, plug, or second valve shall 

seal the open end at all times except during operations 

requiring process fluid flow through the open-ended valve or 

line, or during maintenance or repair. The cap, blind flange, 

plug, or second valve shall be in place within 1 hour of 

cessation of operations requiring process fluid flow through the 

open-ended valve or line, or within 1 hour of cessation of 

maintenance or repair.

(2) Each open-ended valve or line equipped with a second 

valve shall be operated in a manner such that the valve on the 

process fluid end is closed before the second valve is closed.

(3) When a double block and bleed system is being used, the 

bleed valve or line may remain open during operations that 

require venting the line between the block valves but shall 

comply with paragraph (d)(1) of this section at all other times.

(4) Open-ended valves or lines in an emergency shutdown 

system which are designed to open automatically in the event of 

a process upset are exempt from the requirements of paragraphs 

(d)(1) through (3) of this section.

(5) Open-ended valves or lines containing materials which 

would autocatalytically polymerize are exempt from the 

requirements of paragraphs (d)(1) through (3) of this section.

(6) Open-ended valves or lines containing materials which 

could cause an explosion, serious overpressure, or other safety 
Page 100 of 267

hazard if capped or equipped with a double block and bleed 

system as specified in paragraphs (d)(1) through (3) of this 

section are exempt from the requirements of paragraphs (d)(1) 

through (3) of this section.

(e) Standards: valves in gas/vapor service and in light 

liquid service. (1) The provisions of this section apply to 

valves that are either in gas/vapor service or in light liquid 

service.

(2) For existing and new affected sources, all valves 

subject to this section shall be monitored, except as provided 

in paragraph (f) of this section and in §63.177 of subpart H of 

this part, by no later than 1 year after the compliance date.

(3) Monitoring. The owner or operator of a source subject 

to this section shall monitor all valves, except as provided in 

paragraph (f) of this section and in §63.177 of subpart H of 

this part, at the intervals specified in paragraph (e)(4) of 

this section and shall comply with all other provisions of this 

section, except as provided in paragraph (b)(3)(i) of this 

section and §§63.178 and 63.179 of subpart H of this part.

(i) The valves shall be monitored to detect leaks by the 

method specified in §63.180(b) of subpart H of this part.

(ii) An instrument reading of 500 parts per million or 

greater defines a leak.
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(4) Subsequent monitoring frequencies. After conducting the 

initial survey required in paragraph (e)(2) of this section, the 

owner or operator shall monitor valves for leaks at the 

intervals specified below:

(i) For a group of processes with 2 percent or greater 

leaking valves, calculated according to paragraph (e)(6) of this 

section, the owner or operator shall monitor each valve once per 

month, except as specified in paragraph (e)(9) of this section.

(ii) For a group of processes with less than 2 percent 

leaking valves, the owner or operator shall monitor each valve 

once each quarter, except as provided in paragraphs (e)(4)(iii) 

through (v) of this section.

(iii) For a group of processes with less than 1 percent 

leaking valves, the owner or operator may elect to monitor each 

valve once every 2 quarters.

(iv) For a group of processes with less than 0.5 percent 

leaking valves, the owner or operator may elect to monitor each 

valve once every 4 quarters.

(v) For a group of processes with less than 0.25 percent 

leaking valves, the owner or operator may elect to monitor each 

valve once every 2 years.

(5) Calculation of percent leakers. For a group of 

processes to which this subpart applies, the owner or operator 

may choose to subdivide the valves in the applicable group of 
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processes and apply the provisions of paragraph (e)(4) of this 

section to each subgroup. If the owner or operator elects to 

subdivide the valves in the applicable group of processes, then 

the provisions of paragraphs (e)(5)(i) through (viii) of this 

section apply.

(i) The overall performance of total valves in the 

applicable group of processes must be less than 2 percent 

leaking valves, as detected according to paragraphs (e)(3)(i) 

and (ii) of this section and as calculated according to 

paragraphs (e)(6)(ii) and (iii) of this section.

(ii) The initial assignment or subsequent reassignment of 

valves to subgroups shall be governed by the provisions of 

paragraphs (e)(5)(ii) (A) through (C) of this section.

(A) The owner or operator shall determine which valves are 

assigned to each subgroup. Valves with less than 1 year of 

monitoring data or valves not monitored within the last 12 

months must be placed initially into the most frequently 

monitored subgroup until at least 1 year of monitoring data have 

been obtained.

(B) Any valve or group of valves can be reassigned from a 

less frequently monitored subgroup to a more frequently 

monitored subgroup provided that the valves to be reassigned 

were monitored during the most recent monitoring period for the 

less frequently monitored subgroup. The monitoring results must 
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be included with the less frequently monitored subgroup's 

monitoring event and associated next percent leaking valves 

calculation for that group.

(C) Any valve or group of valves can be reassigned from a 

more frequently monitored subgroup to a less frequently 

monitored subgroup provided that the valves to be reassigned 

have not leaked for the period of the less frequently monitored 

subgroup (e.g., for the last 12 months, if the valve or group of 

valves is to be reassigned to a subgroup being monitored 

annually). Nonrepairable valves may not be reassigned to a less 

frequently monitored subgroup.

(iii) The owner or operator shall determine every 6 months 

if the overall performance of total valves in the applicable 

group of processes is less than 2 percent leaking valves and so 

indicate the performance in the next Periodic report. If the 

overall performance of total valves in the applicable group of 

processes is 2 percent leaking valves or greater, the owner or 

operator shall revert to the program required in paragraphs 

(e)(2) through (4) of this section. The overall performance of 

total valves in the applicable group of processes shall be 

calculated as a weighted average of the percent leaking valves 

of each subgroup according to Equation 4 of this subpart:
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Where:

%VLO = overall performance of total valves in the applicable 

group of processes

%VLi = percent leaking valves in subgroup i, most recent 

value calculated according to the procedures in paragraphs 

(e)(6)(ii) and (iii) of this section

Vi = number of valves in subgroup i

n = number of subgroups

(iv) Records. In addition to records required by paragraph 

(g) of this section, the owner or operator shall maintain 

records specified in paragraphs (e)(5)(iv)(A) through (D) of 

this section.

(A) Which valves are assigned to each subgroup,

(B) Monitoring results and calculations made for each 

subgroup for each monitoring period,

(C) Which valves are reassigned and when they were 

reassigned, and

(D) The results of the semiannual overall performance 

calculation required in paragraph (e)(5)(iii) of this section.

(v) The owner or operator shall notify the Administrator no 

later than 30 days prior to the beginning of the next monitoring 
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period of the decision to subgroup valves. The notification 

shall identify the participating processes and the valves 

assigned to each subgroup.

(vi) Semiannual reports. In addition to the information 

required by paragraph (h)(3) of this section, the owner or 

operator shall submit in the Periodic reports the information 

specified in paragraphs (e)(5)(vi)(A) and (B) of this section.

(A) Valve reassignments occurring during the reporting 

period, and

(B) Results of the semiannual overall performance 

calculation required by paragraph (e)(5)(iii) of this section.

(vii) To determine the monitoring frequency for each 

subgroup, the calculation procedures of paragraph (e)(6)(iii) of 

this section shall be used.

(viii) Except for the overall performance calculations 

required by paragraphs (e)(5)(i) and (iii) of this section, each 

subgroup shall be treated as if it were a process for the 

purposes of applying the provisions of this section.

(6)(i) The owner or operator shall decide no later than the 

implementation date of this subpart or upon revision of an 

operating permit how to group the processes. Once the owner or 

operator has decided, all subsequent percentage calculations 

shall be made on the same basis.
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(ii) Percent leaking valves for each group of processes or 

subgroup shall be determined using Equation 5 of this subpart:

Where:

%VL = percent leaking valves

VL = number of valves found leaking excluding nonrepairables 

as provided in paragraph (e)(6)(iv)(A) of this section

VT = total valves monitored, in a monitoring period 

excluding valves monitored as required by paragraph (e)(7)(iii) 

of this section

(iii) When determining monitoring frequency for each group 

of processes or subgroup subject to monthly, quarterly, or 

semiannual monitoring frequencies, the percent leaking valves 

shall be the arithmetic average of the percent leaking valves 

from the last two monitoring periods. When determining 

monitoring frequency for each group of processes or subgroup 

subject to annual or biennial (once every 2 years) monitoring 

frequencies, the percent leaking valves shall be the arithmetic 

average of the percent leaking valves from the last three 

monitoring periods.

(iv)(A) Nonrepairable valves shall be included in the 

calculation of percent leaking valves the first time the valve 

is identified as leaking and nonrepairable and as required to 

comply with paragraph (e)(6)(iv)(B) of this section. Otherwise, 
Page 107 of 267

a number of nonrepairable valves (identified and included in the 

percent leaking calculation in a previous period) up to a 

maximum of 1 percent of the total number of valves in organic 

HAP service at a process may be excluded from calculation of 

percent leaking valves for subsequent monitoring periods.

(B) If the number of nonrepairable valves exceeds 1 percent 

of the total number of valves in organic HAP service at a 

process, the number of nonrepairable valves exceeding 1 percent 

of the total number of valves in organic HAP service shall be 

included in the calculation of percent leaking valves.

(7) Repair provisions. (i) When a leak is detected, it 

shall be repaired as soon as practicable, but no later than 15 

calendar days after the leak is detected, except as provided in 

paragraph (b)(3)(i) of this section.

(ii) A first attempt at repair shall be made no later than 

5 calendar days after each leak is detected.

(iii) When a leak is repaired, the valve shall be monitored 

at least once within the first 3 months after its repair. Days 

that the valve is not in organic HAP service shall not be 

considered part of this 3-month period. The monitoring required 

by this paragraph is in addition to the monitoring required to 

satisfy the definitions of “repaired” and “first attempt at 

repair.”
Page 108 of 267

(A) The monitoring shall be conducted as specified in 

§63.180(b) and (c) as appropriate, to determine whether the 

valve has resumed leaking.

(B) Periodic monitoring required by paragraphs (e)(2) 

through (4) of this section may be used to satisfy the 

requirements of paragraph (e)(7)(iii) of this section, if the 

timing of the monitoring period coincides with the time 

specified in paragraph (e)(7)(iii) of this section. 

Alternatively, other monitoring may be performed to satisfy the 

requirements of paragraph (e)(7)(iii) of this section, 

regardless of whether the timing of the monitoring period for 

periodic monitoring coincides with the time specified in 

paragraph (e)(7)(iii) of this section.

(C) If a leak is detected by monitoring that is conducted 

pursuant to paragraph (e)(7)(iii) of this section, the owner or 

operator shall follow the provisions of paragraphs 

(e)(7)(iii)(C)(1) and (2) of this section to determine whether 

that valve must be counted as a leaking valve for purposes of 

paragraph (e)(6) of this section.

(1) If the owner or operator elects to use periodic 

monitoring required by paragraphs (e)(2) through (4) of this 

section to satisfy the requirements of paragraph (e)(7)(iii) of 

this section, then the valve shall be counted as a leaking 

valve.
Page 109 of 267

(2) If the owner or operator elects to use other monitoring 

prior to the periodic monitoring required by paragraphs (e)(2) 

through (4) of this section to satisfy the requirements of 

paragraph (e)(7)(iii) of this section, then the valve shall be 

counted as a leaking valve unless it is repaired and shown by 

periodic monitoring not to be leaking.

(8) First attempts at repair include, but are not limited 

to, the following practices where practicable:

(i) Tightening of bonnet bolts,

(ii) Replacement of bonnet bolts,

(iii) Tightening of packing gland nuts, and

(iv) Injection of lubricant into lubricated packing.

(9) Any equipment located at a plant site with fewer than 

250 valves in organic HAP service in the affected source is 

exempt from the requirements for monthly monitoring specified in 

paragraph (e)(4)(i) of this section. Instead, the owner or 

operator shall monitor each valve in organic HAP service for 

leaks once each quarter, or comply with paragraph (e)(4)(iii), 

(iv), or (v) of this section, except as provided in paragraph 

(f) of this section.

(f) Unsafe to monitor, difficult-to-monitor, and 

inaccessible equipment. (1) Equipment that is designated as 

unsafe-to-monitor, difficult-to-monitor, or inaccessible is 

exempt from the requirements as specified in paragraphs 
Page 110 of 267

(f)(1)(i) through (iv) of this section provided the owner or 

operator meets the requirements specified in paragraph (f)(2), 

(3), or (4) of this section, as applicable. All equipment, 

except connectors that meet the requirements in paragraph (f)(4) 

of this section, must be assigned to a group of processes. 

Ceramic or ceramic-lined connectors are subject to the same 

requirements as inaccessible connectors.

(i) For pumps and agitators, paragraphs (c)(2), (3), and 

(4) of this section do not apply.

(ii) For valves, paragraphs (e)(2) through (7) of this 

section do not apply.

(iii) For connectors, §63.174(b) through (e) and paragraphs 

(b)(3)(iii)(C) through (G) of this section do not apply.

(iv) For closed-vent systems, §63.172(f)(1), (f)(2), and 

(g) do not apply.

(2) Equipment that is unsafe-to-monitor. (i) Valves, 

connectors, agitators, and any part of closed-vent systems may 

be designated as unsafe-to-monitor if the owner or operator 

determines that monitoring personnel would be exposed to an 

immediate danger as a consequence of complying with the 

monitoring requirements identified in paragraphs (f)(1)(i) 

through (iii) of this section, or the inspection requirements 

identified in paragraph (f)(1)(iv) of this section.
Page 111 of 267

(ii) The owner or operator of equipment that is designated 

as unsafe-to-monitor must have a written plan that requires 

monitoring of the equipment as frequently as practicable during 

safe-to-monitor times. For valves, connectors, and agitators, 

monitoring shall not be more frequent than the periodic 

monitoring schedule otherwise applicable to the group of 

processes in which the equipment is located. For closed-vent 

systems, inspections shall not be more frequent than annually.

(3) Equipment that is difficult-to-monitor. (i) A valve, 

agitator, pump, or any part of a closed-vent system may be 

designated as difficult-to-monitor if the owner or operator 

determines that the equipment cannot be monitored or inspected 

without elevating the monitoring personnel more than 2 meters 

above a support surface or the equipment is not accessible in a 

safe manner when it is in organic HAP service;

(ii) At a new affected source, an owner or operator may 

designate no more than 3 percent of valves as difficult-tomonitor.

(iii) The owner or operator of valves, agitators, or pumps 

designated as difficult-to-monitor must have a written plan that 

requires monitoring of the equipment at least once per calendar 

year or on the periodic monitoring schedule otherwise applicable 

to the group of processes in which the equipment is located, 

whichever is less frequent. For any part of a closed-vent system 
Page 112 of 267

designated as difficult-to-monitor, the owner or operator must 

have a written plan that requires inspection of the closed-vent 

system at least once every 5 years.

(4) Inaccessible, ceramic, or ceramic-lined connectors. (i) 

A connector may be designated as inaccessible if it is:

(A) Buried;

(B) Insulated in a manner that prevents access to the 

equipment by a monitor probe;

(C) Obstructed by equipment or piping that prevents access 

to the equipment by a monitor probe;

(D) Unable to be reached from a wheeled scissor-lift or 

hydraulic-type scaffold which would allow access to equipment up 

to 7.6 meters above the ground; or

(E) Not able to be accessed at any time in a safe manner to 

perform monitoring. Unsafe access includes, but is not limited 

to, the use of a wheeled scissor-lift on unstable or uneven 

terrain, the use of a motorized man-lift basket in areas where 

an ignition potential exists, or access would require near 

proximity to hazards such as electrical lines, or would risk 

damage to equipment.

(F) Would require elevating the monitoring personnel more 

than 2 meters above a permanent support surface or would require 

the erection of scaffold.
Page 113 of 267

(ii) At a new affected source, an owner or operator may 

designate no more than 3 percent of connectors as inaccessible.

(iii) If any inaccessible, ceramic, or ceramic-lined 

connector is observed by visual, audible, olfactory, or other 

means to be leaking, the leak shall be repaired as soon as 

practicable, but no later than 15 calendar days after the leak 

is detected, except as provided in paragraph (b)(3)(i) of this 

section.

(iv) Any connector that is inaccessible or that is ceramic 

or ceramic-lined is exempt from the recordkeeping and reporting 

requirements of paragraphs (g) and (h) of this section.

(g) Recordkeeping requirements. (1) An owner or operator of 

more than one group of processes subject to the provisions of 

this section may comply with the recordkeeping requirements for 

the groups of processes in one recordkeeping system if the 

system identifies with each record the program being implemented 

(e.g., quarterly monitoring) for each type of equipment. All 

records and information required by this section shall be 

maintained in a manner that can be readily accessed at the plant 

site. This could include physically locating the records at the 

plant site or accessing the records from a central location by 

computer at the plant site.

(2) General recordkeeping. Except as provided in paragraph 

(g)(5) of this section, the following information pertaining to 
Page 114 of 267

all equipment subject to the requirements in this section shall 

be recorded:

(i)(A) A list of identification numbers for equipment 

(except instrumentation systems) subject to the requirements of 

this section. Connectors, except those subject to paragraph (f) 

of this section, need not be individually identified if all 

connectors in a designated area or length of pipe subject to the 

provisions of this section are identified as a group, and the 

number of subject connectors is indicated. The list for each 

type of equipment shall be completed no later than the 

completion of the initial survey required for that component. 

The list of identification numbers shall be updated, if needed, 

to incorporate equipment changes within 15 calendar days of the 

completion of each monitoring survey for the type of equipment 

component monitored.

(B) A schedule for monitoring connectors subject to the 

provisions of §63.174(a) of subpart H of this part and valves 

subject to the provisions of paragraph (e)(4) of this section.

(C) Physical tagging of the equipment is not required to 

indicate that it is in organic HAP service. Equipment subject to 

the provisions of this section may be identified on a plant site 

plan, in log entries, or by other appropriate methods.

(ii)(A) A list of identification numbers for equipment that 

the owner or operator elects to equip with a closed-vent system 
Page 115 of 267

and control device, under subject to the provisions of 

paragraphs (b)(4)(iv) or (c)(7) of this section or §§63.164(h) 

or 63.165(c) of subpart H of this part.

(B) A list of identification numbers for compressors that 

the owner or operator elects to designate as operating with an 

instrument reading of less than 500 parts per million above 

background, under the provisions of §63.164(i) of subpart H of 

this part.

(iii)(A) A list of identification numbers for pressure 

relief devices subject to the provisions in §63.165(a) of 

subpart H of this part paragraph (b)(4)(i) of this section.

(B) A list of identification numbers for pressure relief 

devices equipped with rupture disks, under subject to the 

provisions of §63.165(d) of subpart H of this part paragraph 

(b)(4)(ii)(B) of this section.

(iv) Identification of instrumentation systems subject to 

the provisions of this section. Individual components in an 

instrumentation system need not be identified.

(v) The following information shall be recorded for each 

dual mechanical seal system:

(A) Design criteria required by paragraph (c)(5)(vi)(A) of 

this section and §63.164(e)(2) of subpart H of this part, and an 

explanation of the design criteria; and
Page 116 of 267

(B) Any changes to these criteria and the reasons for the 

changes.

(vi) A list of equipment designated as unsafe-to-monitor or 

difficult-to-monitor under paragraph (f) of this section and a 

copy of the plan for monitoring this equipment.

(vii) A list of connectors removed from and added to the 

process, as described in §63.174(i)(1) of subpart H of this 

part, and documentation of the integrity of the weld for any 

removed connectors, as required in §63.174(j) of subpart H of 

this part. This is not required unless the net credits for 

removed connectors is expected to be used.

(viii) For batch processes that the owner or operator 

elects to monitor as provided under §63.178(c) of subpart H of 

this part, a list of equipment added to batch product processes 

since the last monitoring period required in §63.178(c)(3)(ii) 

and (iii) of subpart H of this part. This list must be completed 

for each type of equipment within 15 calendar days of the 

completion of the each monitoring survey for the type of 

equipment monitored.

(3) Records of visual inspections. For visual inspections 

of equipment subject to the provisions of paragraphs (c)(2)(iii) 

and (c)(5)(iv) of this section, the owner or operator shall 

document that the inspection was conducted and the date of the 

inspection. The owner or operator shall maintain records as 
Page 117 of 267

specified in paragraph (g)(4) of this section for leaking 

equipment identified in this inspection, except as provided in 

paragraph (g)(5) of this section. These records shall be 

retained for 5 years.

(4) Monitoring records. When each leak is detected as 

specified in paragraphs (c) and (e) of this section and 

§§63.164, 63.169, 63.172, and 63.174 of subpart H of this part, 

the owner or operator shall record the information specified in 

paragraphs (g)(4)(i) through (ix) of this section. All records 

shall be retained for 5 years, in accordance with the 

requirements of §63.10(b)(1) of subpart A of this part.

(i) The instrument and the equipment identification number 

and the operator name, initials, or identification number.

(ii) The date the leak was detected and the date of first 

attempt to repair the leak.

(iii) The date of successful repair of the leak.

(iv) If postrepair monitoring is required, maximum 

instrument reading measured by Method 21 of 40 CFR part 60, 

appendix A, after it is successfully repaired or determined to 

be nonrepairable.

(v) “Repair delayed” and the reason for the delay if a leak 

is not repaired within 15 calendar days after discovery of the 

leak.
Page 118 of 267

(A) The owner or operator may develop a written procedure 

that identifies the conditions that justify a delay of repair. 

The written procedures may must be included as part of the 

startup/shutdown/malfunction plan, required by §63.1367(a), for 

the source or may be part of a separate document that is 

maintained at the plant site. Reasons for delay of repair may be 

documented by citing the relevant sections of the written 

procedure.

(B) If delay of repair was caused by depletion of stocked 

parts, there must be documentation that the spare parts were 

sufficiently stocked onsite before depletion and the reason for 

depletion.

(vi) If repairs were delayed, dates of process shutdowns 

that occur while the equipment is unrepaired.

(vii)(A) If the alternative in §63.174(c)(1)(ii) of subpart 

H of this part is not in use for the monitoring period, 

identification, either by list, location (area or grouping), or 

tagging of connectors disturbed since the last monitoring period 

required in §63.174(b) of subpart H of this part, as described 

in §63.174(c)(1) of subpart H of this part.

(B) The date and results of follow-up monitoring as 

required in §63.174(c) of subpart H of this part. If 

identification of disturbed connectors is made by location, then 
Page 119 of 267

all connectors within the designated location shall be 

monitored.

(viii) The date and results of the monitoring required in 

§63.178(c)(3)(i) of subpart H of this part for equipment added 

to a batch process since the last monitoring period required in 

§63.178(c)(3)(ii) and (iii) of subpart H of this part. If no 

leaking equipment is found in this monitoring, the owner or 

operator shall record that the inspection was performed. Records 

of the actual monitoring results are not required.

(ix) Copies of the periodic reports as specified in 

paragraph (h)(3) of this section, if records are not maintained 

on a computerized data base capable of generating summary 

reports from the records.

(5) Records of pressure tests. The owner or operator who 

elects to pressure test a process equipment train and supply 

lines between storage and processing areas to demonstrate 

compliance with this section is exempt from the requirements of 

paragraphs (g)(2), (3), (4), and (6) of this section. Instead, 

the owner or operator shall maintain records of the following 

information:

(i) The identification of each product, or product code, 

produced during the calendar year. It is not necessary to 

identify individual items of equipment in the process equipment 

train.
Page 120 of 267

(ii) Records demonstrating the proportion of the time 

during the calendar year the equipment is in use in the process 

that is subject to the provisions of this subpart. Examples of 

suitable documentation are records of time in use for individual 

pieces of equipment or average time in use for the process unit. 

These records are not required if the owner or operator does not 

adjust monitoring frequency by the time in use, as provided in 

§63.178(c)(3)(iii) of subpart H of this part.

(iii) Physical tagging of the equipment to identify that it 

is in organic HAP service and subject to the provisions of this 

section is not required. Equipment in a process subject to the 

provisions of this section may be identified on a plant site 

plan, in log entries, or by other appropriate methods.

(iv) The dates of each pressure test required in §63.178(b) 

of subpart H of this part, the test pressure, and the pressure 

drop observed during the test.

(v) Records of any visible, audible, or olfactory evidence 

of fluid loss.

(vi) When a process equipment train does not pass two 

consecutive pressure tests, the following information shall be 

recorded in a log and kept for 2 years:

(A) The date of each pressure test and the date of each 

leak repair attempt.
Page 121 of 267

(B) Repair methods applied in each attempt to repair the 

leak.

(C) The reason for the delay of repair.

(D) The expected date for delivery of the replacement 

equipment and the actual date of delivery of the replacement 

equipment.

(E) The date of successful repair.

(6) Records of compressor and pressure relief valve device 

compliance tests. The dates and results of each compliance test 

required for compressors subject to the provisions in §63.164(i) 

of subpart H of this part and the dates and results of the 

Method 21 of 40 CFR part 60, appendix A, monitoring following a 

pressure release for each pressure relief device subject to the 

provisions in §63.165(a) and (b) of subpart H of this part

paragraphs (b)(4)(i) and (ii) of this section. The results shall 

include:

(i) The background level measured during each compliance 

test.

(ii) The maximum instrument reading measured at each piece 

of equipment during each compliance test.

(7) Records for closed-vent systems. The owner or operator 

shall maintain records of the information specified in 

paragraphs (g)(7)(i) through (iii) of this section for closedvent systems and control devices subject to the provisions of 
Page 122 of 267

paragraph (b)(3)(ii) of this section. The records specified in 

paragraph (g)(7)(i) of this section shall be retained for the 

life of the equipment. The records specified in paragraphs 

(g)(7)(ii) and (iii) of this section shall be retained for 5 

years.

(i) The design specifications and performance 

demonstrations specified in paragraphs (g)(7)(i)(A) through (D)

of this section.

(A) Detailed schematics, design specifications of the 

control device, and piping and instrumentation diagrams.

(B) The dates and descriptions of any changes in the design 

specifications.

(C) The flare design (i.e., steam assisted, air assisted, 

or nonassisted) and the results of the compliance demonstration 

required by §63.11(b) of subpart A of this part.

(D) A description of the parameter or parameters monitored, 

as required in paragraph (b)(3)(ii) of this section, to ensure 

that control devices are operated and maintained in conformance 

with their design and an explanation of why that parameter (or 

parameters) was selected for the monitoring.

(ii) Records of operation of closed-vent systems and 

control devices.

(A) Dates and durations when the closed-vent systems and 

control devices required in paragraph (c) of this section and 
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§§63.164 through 63.166 of subpart H of this part are not 

operated as designed as indicated by the monitored parameters, 

including periods when a flare pilot light system does not have 

a flame.

(B) Dates and durations during which the monitoring system 

or monitoring device is inoperative.

(C) Dates and durations of startups and shutdowns of 

control devices required in paragraph (c) of this section and 

§§63.164 through 63.166 of subpart H of this part.

(iii) Records of inspections of closed-vent systems subject 

to the provisions of §63.172 of subpart H of this part.

(A) For each inspection conducted in accordance with the 

provisions of §63.172(f)(1) or (2) of subpart H of this part 

during which no leaks were detected, a record that the 

inspection was performed, the date of the inspection, and a 

statement that no leaks were detected.

(B) For each inspection conducted in accordance with the 

provisions of §63.172(f)(1) or (f)(2) of subpart H of this part 

during which leaks were detected, the information specified in 

paragraph (g)(4) of this section shall be recorded.

(8) Records for components in heavy liquid service. 

Information, data, and analysis used to determine that a piece 

of equipment or process is in heavy liquid service shall be 

recorded. Such a determination shall include an analysis or 
Page 124 of 267

demonstration that the process fluids do not meet the criteria 

of “in light liquid or gas/vapor service.” Examples of 

information that could document this include, but are not 

limited to, records of chemicals purchased for the process, 

analyses of process stream composition, engineering 

calculations, or process knowledge.

(9) Records of exempt components. Identification, either by 

list, location (area or group), or other method of equipment in 

organic HAP service less than 300 hr/yr subject to the 

provisions of this section.

(10) Records of alternative means of compliance 

determination. Owners and operators choosing to comply with the 

requirements of §63.179 of subpart H of this part shall maintain 

the following records:

(i) Identification of the process(es) and the organic HAP 

they handle.

(ii) A schematic of the process, enclosure, and closed-vent 

system.

(iii) A description of the system used to create a negative 

pressure in the enclosure to ensure that all emissions are 

routed to the control device.

(11) Records of pressure releases to the atmosphere from 

pressure relief devices. For pressure relief devices in organic 

HAP service subject to paragraph (b)(4)(iii) of this section, 
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keep records of each pressure release to the atmosphere, 

including the following information:

(i) The source, nature, and cause of the pressure release.

(ii) The date, time, and duration of the pressure release.

(iii) The quantity of total HAP emitted during the pressure 

release and the calculations used for determining this quantity.

(iv) The actions taken to prevent this pressure release.

(v) The measures adopted to prevent future such pressure 

releases.

(h) Reporting Requirements. (1) Each owner or operator of a 

source subject to this section shall submit the reports listed 

in paragraphs (h)(1)(i) and (ii) of this section.

(i) A Notification of Compliance Status report described in 

paragraph (h)(2) of this section, and

(ii) Periodic reports described in paragraph (h)(3) of this 

section.

(2) Notification of compliance status report. Each owner or 

operator of a source subject to this section shall submit the 

information specified in paragraphs (h)(2)(i) through (iii) of 

this section in the Notification of Compliance Status report 

described in §63.1368(f). For pressure relief devices subject to 

the requirements of paragraph (b)(4)(iii) of this section, the 

owner or operator shall submit the information listed in 

paragraph (h)(2)(iv) of this section in the Notification of 
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Compliance Status within 150 days after the first applicable 

compliance date for pressure relief device monitoring. Section 

63.9(j) of subpart A of this part shall not apply to the 

Notification of Compliance Status report.

(i) The notification shall provide the information listed 

in paragraphs (h)(2)(i)(A) through (C) of this section for each 

group of processes subject to the requirements of paragraphs (b) 

through (g) of this section.

(A) Identification of the group of processes.

(B) Approximate number of each equipment type (e.g., 

valves, pumps) in organic HAP service, excluding equipment in 

vacuum service.

(C) Method of compliance with the standard (for example, 

“monthly leak detection and repair” or “equipped with dual 

mechanical seals”).

(ii) The notification shall provide the information listed 

in paragraphs (h)(2)(ii)(A) and (B) of this section for each 

process subject to the requirements of paragraph (b)(3)(iv) of 

this section and §63.178(b) of subpart H of this part.

(A) Products or product codes subject to the provisions of 

this section, and

(B) Planned schedule for pressure testing when equipment is 

configured for production of products subject to the provisions 

of this section.
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(iii) The notification shall provide the information listed 

in paragraphs (h)(2)(iii)(A) and (B) of this section for each 

process subject to the requirements in §63.179 of subpart H of 

this part.

(A) Process identification.

(B) A description of the system used to create a negative 

pressure in the enclosure and the control device used to comply 

with the requirements of paragraph (b)(3)(ii) of this section.

(iv) For pressure relief devices in organic HAP service, a 

description of the device or monitoring system to be 

implemented, including the pressure relief devices and process 

parameters to be monitored (if applicable), a description of the 

alarms or other methods by which operators will be notified of a 

pressure release, and a description of how the owner or operator 

will determine the information to be recorded under paragraph 

(g)(11)(ii)-(iii) of this section (i.e., the duration of the 

pressure release and the methodology and calculations for 

determining of the quantity of total HAP emitted during the 

pressure release).

(3) Periodic reports. The owner or operator of a source 

subject to this section shall submit Periodic reports.

(i) A report containing the information in paragraphs 

(h)(3)(ii), (iii), and through (iv) of this section shall be 

submitted semiannually. The first Periodic report shall be 
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submitted no later than 240 days after the date the Notification 

of Compliance Status report is due and shall cover the 6-month 

period beginning on the date the Notification of Compliance 

Status report is due. Each subsequent Periodic report shall 

cover the 6-month period following the preceding period.

(ii) For equipment complying with the provisions of 

paragraphs (b) through (g) of this section, the Periodic report 

shall contain the summary information listed in paragraphs 

(h)(3)(ii)(A) through (L) of this section for each monitoring 

period during the 6-month period.

(A) The number of valves for which leaks were detected as 

described in paragraph (e)(2) of this section, the percent 

leakers, and the total number of valves monitored;

(B) The number of valves for which leaks were not repaired 

as required in paragraph (e)(7) of this section, identifying the 

number of those that are determined nonrepairable;

(C) The number of pumps and agitators for which leaks were 

detected as described in paragraph (c)(2) of this section, the 

percent leakers, and the total number of pumps and agitators 

monitored;

(D) The number of pumps and agitators for which leaks were 

not repaired as required in paragraph (c)(3) of this section;

(E) The number of compressors for which leaks were detected 

as described in §63.164(f) of subpart H of this part;
Page 129 of 267

(F) The number of compressors for which leaks were not 

repaired as required in §63.164(g) of subpart H of this part;

(G) The number of connectors for which leaks were detected 

as described in §63.174(a) of subpart H of this part, the 

percent of connectors leaking, and the total number of 

connectors monitored;

(H) The number of connectors for which leaks were not 

repaired as required in §63.174(d) of subpart H of this part, 

identifying the number of those that are determined 

nonrepairable;

(I) The facts that explain any delay of repairs and, where 

appropriate, why a process shutdown was technically infeasible.

(J) The results of all monitoring to show compliance with 

§§63.164(i), 63.165(a), and 63.172(f) of subpart H of this part 

conducted within the semiannual reporting period.

(K) If applicable, the initiation of a monthly monitoring 

program under either paragraph (c)(4)(ii) or paragraph 

(e)(4)(i)(A) of this section.

(L) If applicable, notification of a change in connector 

monitoring alternatives as described in §63.174(c)(1) of subpart 

H of this part.

(iii) For owners or operators electing to meet the 

requirements of §63.178(b) of subpart H of this part, the 

Periodic report shall include the information listed in 
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paragraphs (h)(3)(iii) (A) through (E) of this section for each 

process.

(A) Product process equipment train identification;

(B) The number of pressure tests conducted;

(C) The number of pressure tests where the equipment train 

failed either the retest or two consecutive pressure tests;

(D) The facts that explain any delay of repairs; and

(E) The results of all monitoring to determine compliance 

with §63.172(f) of subpart H of this part.

(iv) Any change in the information submitted under 

paragraph (h)(2) of this section shall be provided in the next 

Periodic report.

(v) For pressure relief devices in organic HAP service, 

Periodic Reports must include the information specified in 

paragraphs (h)(3)(v)(A) through (C) of this section.

(A) For pressure relief devices in organic HAP service 

subject to paragraph (b)(4) of this section, report confirmation 

that all monitoring to show compliance was conducted within the 

reporting period.

(B) For pressure relief devices in organic HAP gas or vapor 

service subject to paragraph (b)(4)(ii) of this section, report 

any instrument reading of 500 ppm above background or greater, 

more than 5 calendar days after the pressure release.
Page 131 of 267

(C) For pressure relief devices in organic HAP service 

subject to paragraph (b)(4)(iii) of this section, report each 

pressure release to the atmosphere, including the following 

information:

(1) The source, nature, and cause of the pressure release.

(2) The date, time, and duration of the pressure release.

(3) The quantity of total HAP emitted during the pressure 

release and the method used for determining this quantity.

(4) The actions taken to prevent this pressure release.

(5) The measures adopted to prevent future such pressure 

releases.

§63.1364 Compliance dates.

(a) Compliance dates for existing sources. (1) An owner or 

operator of an existing affected source must comply with the 

provisions in this subpart (except §63.1363(b)(4)(iii)) by 

December 23, 2003. Compliance with the pressure relief device 

monitoring provisions of §63.1363(b)(4)(iii) shall occur no 

later than [INSERT DATE 3 YEARS AFTER DATE OF PUBLICATION IN THE 

FEDERAL REGISTER].

(2) Pursuant to section 112(i)(3)(B) of the CAA, an owner 

or operator of an existing source may request an extension of up 

to 1 additional year to comply with the provisions of this 

subpart if the additional time is needed for the installation of 

controls.
Page 132 of 267

(i) For purposes of this subpart, a request for an 

extension shall be submitted no later than 120 days prior to the 

compliance date specified in paragraph (a)(1) of this section, 

except as provided in paragraph (a)(2)(ii) of this section. The 

dates specified in §63.6(i) of subpart A of this part for 

submittal of requests for extensions shall not apply to sources 

subject to this subpart.

(ii) An owner or operator may submit a compliance extension 

request after the date specified in paragraph (a)(1)(i) of this 

section provided the need for the compliance extension arose 

after that date and before the otherwise applicable compliance 

date, and the need arose due to circumstances beyond reasonable 

control of the owner or operator. This request shall include the 

data described in §63.6(i)(8)(A), (B), and (D) of subpart A of 

this part.

(b) Compliance dates for new and reconstructed sources. An 

owner or operator of a new or reconstructed affected source must 

comply with the provisions of this subpart (except 

§63.1363(b)(4)(iii)) on June 23, 1999 or upon startup, whichever 

is later. New or reconstructed affected sources that commenced 

construction after November 10, 1997, but on or before January 

9, 2012, must be in compliance with the pressure relief device 

monitoring provisions of §63.1363(b)(4)(iii) no later than 

[INSERT DATE 3 YEARS AFTER DATE OF PUBLICATION IN THE FEDERAL 
Page 133 of 267

REGISTER]. New or reconstructed sources that commenced 

construction after January 9, 2012, must be in compliance with 

the pressure relief device monitoring provisions of 

§63.1363(b)(4)(iii) upon initial startup or by [INSERT DATE OF 

PUBLICATION IN THE FEDERAL REGISTER], whichever is later.

§63.1365 Test methods and initial compliance procedures.

(a) General. Except as specified in paragraph (a)(4) of 

this section, the procedures specified in paragraphs (c), (d), 

(e), (f), and (g) of this section are required to demonstrate 

initial compliance with §63.1362(b), (c), (d), (f), and (g), 

respectively. The provisions in paragraph (a)(1) of this section 

apply to design evaluations that are used to demonstrate 

compliance with the standards for process vents and storage 

vessels. The provisions in paragraph (a)(2) of this section 

apply to performance tests that are specified in paragraphs (c), 

(d), and (e) of this section. The provisions in paragraph (a)(3) 

of this section describe initial compliance procedures for 

flares. The provisions in paragraph (a)(5) of this section are 

used to demonstrate initial compliance with the alternative 

standards specified in §63.1362(b)(6) and (c)(4). The provisions 

in paragraph (a)(6) of this section are used to comply with the 

outlet concentration requirements specified in 

§63.1362(b)(2)(iv)(A), (b)(3)(ii), (b)(4)(ii)(A), (b)(5)(ii), 

and (b)(5)(iii).
Page 134 of 267

(1) Design evaluation. To demonstrate that a control device 

meets the required control efficiency, a design evaluation must 

address the composition and HAP concentration of the vent stream 

entering the control device. A design evaluation also must 

address other vent stream characteristics and control device 

operating parameters as specified in any one of paragraphs 

(a)(1)(i) through (vii) of this section, depending on the type 

of control device that is used. If the vent stream is not the 

only inlet to the control device, the efficiency demonstration 

also must consider all other vapors, gases, and liquids, other 

than fuels, received by the control device.

(i) For an enclosed combustion device used to comply with 

the provisions of §63.1362(b)(2)(iv), (b)(4)(ii), (c)(2)(iv)(B), 

or (c)(3) with a minimum residence time of 0.5 seconds and a 

minimum temperature of 760 °C, the design evaluation must 

document that these conditions exist.

(ii) For a combustion control device that does not satisfy 

the criteria in paragraph (a)(1)(i) of this section, the design 

evaluation must document control efficiency and address the 

following characteristics, depending on the type of control 

device:

(A) For a thermal vapor incinerator, the design evaluation 

must consider the autoignition temperature of the organic HAP, 

must consider the vent stream flow rate, and must establish the 
Page 135 of 267

design minimum and average temperature in the combustion zone 

and the combustion zone residence time.

(B) For a catalytic vapor incinerator, the design 

evaluation must consider the vent stream flow rate and must 

establish the design minimum and average temperatures across the 

catalyst bed inlet and outlet.

(C) For a boiler or process heater, the design evaluation 

must consider the vent stream flow rate, must establish the 

design minimum and average flame zone temperatures and 

combustion zone residence time, and must describe the method and 

location where the vent stream is introduced into the flame 

zone.

(iii) For a condenser, the design evaluation must consider 

the vent stream flow rate, relative humidity, and temperature, 

and must establish the maximum temperature of the condenser 

exhaust vent stream and the corresponding outlet organic HAP 

compound concentration level or emission rate for which the 

required reduction is achieved.

(iv) For a carbon adsorption system that regenerates the 

carbon bed directly onsite in the control device such as a 

fixed-bed adsorber, the design evaluation must consider the vent 

stream flow rate, relative humidity, and temperature, and must 

establish the design exhaust vent stream organic compound 

concentration level, adsorption cycle time, number of carbon 
Page 136 of 267

beds and their capacities, type and working capacity of 

activated carbon used for the carbon beds, design total 

regeneration stream mass or volumetric flow over the period of 

each complete carbon bed regeneration cycle, design carbon bed 

temperature after regeneration, design carbon bed regeneration 

time, and design service life of carbon. For vacuum desorption, 

the pressure drop must be included.

(v) For a carbon adsorption system that does not regenerate 

the carbon bed directly onsite in the control device such as a 

carbon canister, the design evaluation must consider the vent 

stream mass or volumetric flow rate, relative humidity, and 

temperature, and must establish the design exhaust vent stream 

organic compound concentration level, capacity of the carbon 

bed, type and working capacity of activated carbon used for the 

carbon bed, and design carbon replacement interval based on the 

total carbon working capacity of the control device and source 

operating schedule.

(vi) For a scrubber, the design evaluation must consider 

the vent stream composition, constituent concentrations, liquidto-vapor ratio, scrubbing liquid flow rate and concentration, 

temperature, and the reaction kinetics of the constituents with 

the scrubbing liquid. The design evaluation must establish the 

design exhaust vent stream organic compound concentration level 

and must include the additional information in paragraphs 
Page 137 of 267

(a)(1)(vi)(A) and (B) of this section for trays and a packed 

column scrubber.

(A) Type and total number of theoretical and actual trays;

(B) Type and total surface area of packing for entire 

column, and for individual packed sections if column contains 

more than one packed section.

(vii) For fabric filters, the design evaluation must 

include the pressure drop through the device and the net gas-tocloth ratio (i.e., cubic feet of gas per square feet of cloth).

(2) Calculation of TOC or total organic HAP concentration. 

The TOC concentration or total organic HAP concentration is the 

sum of the concentrations of the individual components. If 

compliance is being determined based on TOC, the owner or 

operator shall compute TOC for each run using Equation 6 of this 

subpart. If compliance is being determined based on total 

organic HAP, the owner or operator shall compute total organic 

HAP using Equation 6 of this subpart, except that only organic 

HAP compounds shall be summed; when determining compliance with 

the wastewater provisions of §63.1362(d), the organic HAP 

compounds shall consist of the organic HAP compounds in Table 9 

of subpart G of this part.

Where:
Page 138 of 267

CGT = total concentration of TOC or organic HAP in vented 

gas stream, average of samples, dry basis, ppmv

CGSi,j = concentration of sample components in vented gas 

stream for sample j, dry basis, ppmv

n = number of compounds in the sample

m = number of samples in the sample run.

(3) Initial compliance using flares. When a flare is used 

to comply with the standards, the owner or operator shall comply 

with the provisions specified in §63.11(b) of subpart A of this 

part.

(i) The initial compliance determination shall consist of a 

visible emissions determination using Method 22 of 40 CFR part 

60, appendix A, as described in §63.11(b)(4) of subpart A of 

this part, and a determination of net heating value of gas being 

combusted and exit velocity to comply with the requirements of 

§63.11(b)(6) through (8) of subpart A of this part. The net 

heating value and exit velocity shall be based on the results of 

performance testing under the conditions described in paragraphs 

(b)(10) and (11) of this section.

(ii) An owner or operator is not required to conduct a 

performance test to determine percent emission reduction or 

outlet organic HAP or TOC concentration when a flare is used.

(4) Exemptions from compliance demonstrations. An owner or 

operator using any control device specified in paragraphs 
Page 139 of 267

(a)(4)(i) through (ii) of this section is exempt from the 

initial compliance provisions in paragraphs (c), (d), and (e) of 

this section.

(i) A boiler or process heater with a design heat input 

capacity of 44 megawatts or greater.

(ii) A boiler or process heater into which the emission 

stream is introduced with the primary fuel.

(5) Initial compliance with alternative standard. Initial 

compliance with the alternative standards in §63.1362(b)(6) and 

(c)(4) for combustion devices is demonstrated when the outlet 

TOC concentration is 20 ppmv or less, and the outlet HCl and 

chlorine concentration is 20 ppmv or less. Initial compliance 

with the alternative standards in §63.1362(b)(6) and (c)(4) for 

noncombustion devices is demonstrated when the outlet TOC 

concentration is 50 ppmv or less, and the outlet HCl and 

chlorine concentration is 50 ppmv or less. To demonstrate 

initial compliance, the owner or operator shall be in compliance 

with the monitoring provisions in §63.1366(b)(5) on the initial 

compliance date. The owner or operator shall use Method 18 to 

determine the predominant organic HAP in the emission stream if 

the TOC monitor is calibrated on the predominant HAP.

(6) Initial compliance with the 20 ppmv outlet limit. 

Initial compliance with the 20 ppmv TOC or total organic HAP 

concentration is demonstrated when the outlet TOC or total 
Page 140 of 267

organic HAP concentration is 20 ppmv or less. Initial compliance 

with the 20 ppmv HCl and chlorine concentration is demonstrated 

when the outlet HCl and chlorine concentration is 20 ppmv or 

less. To demonstrate initial compliance, the operator shall use 

applicable test methods described in paragraphs (b)(1) through 

(9) of this section, and test under conditions described in 

paragraph (b)(10) or (11) of this section, as applicable. The 

owner or operator shall comply with the monitoring provisions in 

§63.1366(b)(1) through (5) on the initial compliance date.

(7) Outlet concentration correction for supplemental gases. 

If supplemental gases are added to a vent stream for which 

compliance with an outlet concentration standard in §63.1362 or 

63.1363 will be demonstrated, the owner or operator must correct 

the outlet concentration as specified in paragraphs (a)(7)(i) 

and (ii) of this section.

(i) Combustion device. Except as specified in 

§63.1366(b)(5)(ii)(A), if the vent stream is controlled with a 

combustion device, the owner or operator must comply with the 

provisions in paragraphs (a)(7)(i)(A) through (C) of this 

section.

(A) To comply with a TOC or total organic HAP outlet 

concentration standard in §63.1362(b)(2)(iv)(A), (b)(4)(ii)(A), 

(b)(6), (c)(2)(iv)(B), (c)(4), (d)(13), or §63.172, the actual 

TOC outlet concentration must be corrected to 3 percent oxygen.
Page 141 of 267

(B) If the inlet stream to the combustion device contains 

any HCl, chlorine, or halogenated compounds, and the owner or 

operator elects to comply with a total HCl and chlorine outlet 

concentration standard in §63.1362(b)(3)(ii), (b)(5)(ii), 

(b)(5)(iii), (b)(6), or (c)(4), the actual total HCl and 

chlorine outlet concentration must be corrected to 3 percent 

oxygen.

(C) The integrated sampling and analysis procedures of 

Method 3B of 40 CFR part 60, appendix A, shall be used to 

determine the actual oxygen concentration (%O2d). The samples 

shall be taken during the same time that the TOC, total organic 

HAP, and total HCl and chlorine samples are taken. The 

concentration corrected to 3 percent oxygen (Cd) shall be 

computed using Equation 7 of this subpart:

Where:

Cc = concentration of TOC, total organic HAP, or total HCl 

and chlorine corrected to 3 percent oxygen, dry basis, ppmv

Cm = total concentration of TOC, total organic HAP, or total 

HCl and chlorine in the vented gas stream, average of samples, 

dry basis, ppmv

%O2d = concentration of oxygen measured in vented gas 

stream, dry basis, percent by volume.
Page 142 of 267

(ii) Noncombustion devices. If a control device other than 

a combustion device, and not in series with a combustion device, 

is used to comply with a TOC, total organic HAP, or total HCl 

and chlorine outlet concentration standard, the owner or 

operator must correct the actual concentration for supplemental 

gases using Equation 8 of this subpart.

Where:

Ca = corrected outlet TOC, total organic HAP, or total HCl 

and chlorine concentration, dry basis, ppmv

Cm = actual TOC, total organic HAP, or total HCl and 

chlorine concentration measured at control device outlet, dry 

basis, ppmv

Va = total volumetric flow rate of affected streams vented 

to the control device

Vs = total volumetric flow rate of supplemental gases.

(b) Test methods and conditions. When testing is conducted 

to measure emissions from an affected source, the test methods 

specified in paragraphs (b)(1) through (9) of this section shall 

be used. Compliance and performance tests shall be performed 

under such conditions as the Administrator specifies to the 

owner or operator based on representative performance of the 

affected source for the period being tested and as specified in 
Page 143 of 267

paragraphs (b)(10) and (11) of this section. Representative 

conditions exclude periods of startup and shutdown unless 

specified by the Administrator or an applicable subpart. The 

owner or operator may not conduct performance tests during 

periods of malfunction. The owner or operator must record the 

process information that is necessary to document operating 

conditions during the test and include in such record an 

explanation to support that such conditions represent normal 

operation. Upon request, the owner or operator shall make 

available to the Administrator such records as may be necessary 

to determine the conditions of performance tests.

(1) Method 1 or 1A of appendix A of 40 CFR part 60 shall be 

used for sample and velocity traverses.

(2) Method 2, 2A, 2C, or 2D of appendix A of 40 CFR part 60 

shall be used for velocity and volumetric flow rates.

(3) Method 3 of appendix A of 40 CFR part 60 shall be used 

for gas analysis.

(4) Method 4 of appendix A of 40 CFR part 60 shall be used 

for stack gas moisture.

(5) Concentration measurements shall be adjusted to negate 

the dilution effects of introducing nonaffected gaseous streams 

into the vent streams prior to control or measurement. The 

following methods are specified for concentration measurements 

of organic compounds:
Page 144 of 267

(i) Method 18 of appendix A of 40 CFR part 60 may be used 

to determine HAP concentration in any control device efficiency 

determination.

(ii) Method 25 of appendix A of 40 CFR part 60 may be used 

to determine total gaseous nonmethane organic concentration for 

control efficiency determinations in combustion devices.

(iii) Method 25A of appendix A of 40 CFR part 60 may be 

used to determine the HAP or TOC concentration for control 

device efficiency determinations under the conditions specified 

in Method 25 of appendix A of 40 CFR part 60 for direct 

measurement of an effluent with a flame ionization detector, or 

in demonstrating compliance with the 20 ppmv TOC outlet 

standard. If Method 25A of appendix A of 40 CFR part 60 is used 

to determine the concentration of TOC for the 20 ppmv standard, 

the instrument shall be calibrated on methane or the predominant 

HAP. If calibrating on the predominant HAP, the use of Method 

25A of appendix A of 40 CFR part 60 shall comply with paragraphs 

(b)(5)(i)(A) through (C) of this section.

(A) The organic HAP used as the calibration gas for Method 

25A, 40 CFR part 60, appendix A, shall be the single organic HAP 

representing the largest percent by volume.

(B) The use of Method 25A, 40 CFR part 60, appendix A, is 

acceptable if the response from the high level calibration gas 

is at least 20 times the standard deviation of the response from 
Page 145 of 267

the zero calibration gas when the instrument is zeroed on the 

most sensitive scale.

(C) The span value of the analyzer must be less than 100 

ppmv.

(6) The methods in either paragraph (b)(6)(i) or (ii) of 

this section shall be used to determine the concentration, in 

mg/dscm, of total HCl and chlorine. Concentration measurements 

shall be adjusted to negate the dilution effects of introducing 

nonaffected gaseous streams into the vent streams prior to 

control or measurement.

(i) Method 26 or 26A of 40 CFR part 60, appendix A.

(ii) Any other method if the method or data have been 

validated according to the applicable procedures of Method 301 

of appendix A of this part.

(7) Method 5 of appendix A of 40 CFR part 60 shall be used 

to determine the concentration of particulate matter in exhaust 

gas streams from bag dumps and product dryers.

(8) Wastewater analysis shall be conducted in accordance 

with §63.144(b)(5)(i) through (iii) or as specified in paragraph 

(b)(8)(i) or (ii) of this section.

(i) As an alternative to the methods specified in 

§63.144(b)(5)(i), an owner or operator may conduct wastewater 

analyses using Method 1666 or 1671 of 40 CFR part 136, appendix 

A, and comply with the sampling protocol requirements specified 
Page 146 of 267

in §63.144(b)(5)(ii). The validation requirements specified in 

§63.144(b)(5)(iii) do not apply if an owner or operator uses 

Method 1666 or 1671 of 40 CFR part 136, appendix A.

(ii) As an alternative to the methods specified in 

§63.144(b)(5)(i), an owner or operator may use procedures 

specified in Method 8260 or 8270 in “Test Methods for Evaluating 

Solid Waste, Physical/Chemical Methods,” EPA Publication No. SW–

846, Third Edition, September 1986, as amended by Update I, 

November 15, 1992. An owner or operator also may use any more 

recent, updated version of Method 8260 or 8270 approved by EPA. 

For the purpose of using Method 8260 or 8270 to comply with this 

subpart, the owner or operator must maintain a formal quality 

assurance program consistent with either Section 8 of Method 

8260 or Method 8270. This program must include the elements 

related to measuring the concentrations of volatile compounds 

that are specified in paragraphs (b)(8)(ii)(A) through (C) of 

this section.

(A) Documentation of site-specific procedures to minimize 

the loss of compounds due to volatilization, biodegradation, 

reaction, or sorption during the sample collection, storage, and 

preparation steps.

(B) Documentation of specific quality assurance procedures 

followed during sampling, sample preparation, sample 

introduction, and analysis.
Page 147 of 267

(C) Measurement of the average accuracy and precision of 

the specific procedures, including field duplicates and field 

spiking of the material source before or during sampling with 

compounds having similar chemical characteristics to the target 

analytes.

(9) Method 22 of appendix A of 40 CFR part 60 shall be used 

to determine visible emissions from flares.

(10) Testing conditions for continuous processes. Testing 

of process vents on equipment operating as part of a continuous 

process shall consist of three one-hour runs. Gas stream 

volumetric flow rates shall be measured every 15 minutes during 

each 1-hour run. Organic HAP concentration shall be determined 

from samples collected in an integrated sample over the duration 

of each one-hour test run, or from grab samples collected 

simultaneously with the flow rate measurements (every 15 

minutes). If an integrated sample is collected for laboratory 

analysis, the sampling rate shall be adjusted proportionally to 

reflect variations in flow rate. For continuous gas streams, the 

emission rate used to determine compliance shall be the average 

emission rate of the three test runs.

(11) Testing conditions for batch processes. Testing of 

emissions on equipment where the flow of gaseous emissions is 

intermittent (batch operations) shall be conducted at absolute 

peak-case conditions or hypothetical peak-case conditions, as 
Page 148 of 267

specified in paragraphs (b)(11)(i) and (ii) of this section, 

respectively. Gas stream volumetric flow rates shall be measured 

at 15-minute intervals. Organic HAP, TOC, or HCl and chlorine 

concentration shall be determined from samples collected in an 

integrated sample over the duration of the test, or from grab 

samples collected simultaneously with the flow rate measurements 

(every 15 minutes). If an integrated sample is collected for 

laboratory analysis, the sampling rate shall be adjusted 

proportionally to reflect variations in flow rate. In all cases, 

a site-specific test plan shall be submitted to the 

Administrator for approval prior to testing in accordance with 

§63.7(c). The test plan shall include the emissions profile 

described in paragraph (b)(11)(iii) of this section. The term 

“HAP mass loading” as used in paragraphs (b)(11)(i) through 

(iii) of this section refers to the class of HAP, either organic 

or HCl and chlorine, that the control device is intended to 

control.

(i) Absolute peak-case. If the most challenging conditions 

for the control device occur under maximum HAP load, the 

absolute peak-case conditions shall be characterized by the 

criteria presented in paragraph (b)(11)(i)(A) or (B) of this 

section. Otherwise, absolute peak-case conditions are defined by 

the conditions in paragraph (b)(11)(i)(C) of this section.
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(A) The period in which the inlet to the control device 

will contain at least 50 percent of the maximum HAP mass load 

that may be vented to the control device over any 8-hour period. 

An emission profile as described in paragraph (b)(11)(iii)(A) of 

this section shall be used to identify the 8-hour period that 

includes the maximum projected HAP load.

(B) A 1-hour period of time in which the inlet to the 

control device will contain the highest hourly HAP mass loading 

rate that may be vented to the control device. An emission 

profile as described in paragraph (b)(11)(iii)(A) of this 

section shall be used to identify the 1-hour period of maximum 

HAP loading.

(C) The period of time when a condition other than the 

maximum HAP load is most challenging for the control device. 

These conditions include, but are not limited to the following:

(1) Periods when the streams contain the highest combined 

VOC and HAP hourly load, as described by the emission profiles 

in paragraph (b)(11)(iii) of this section; or

(2) Periods when the streams contain HAP constituents that 

approach the limits of solubility for scrubbing media; or

(3) Periods when the streams contain HAP constituents that 

approach the limits of adsorptivity for carbon adsorption 

systems.
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(ii) Hypothetical peak-case. Hypothetical peak-case 

conditions are simulated test conditions that, at a minimum, 

contain the highest total average hourly HAP load of emissions 

that would be predicted to be vented to the control device from 

the emissions profile described in either paragraph 

(b)(11)(iii)(B) or (C) of this section.

(iii) Emissions profile. The owner or operator may choose 

to perform tests only during those periods of the peak-case 

episode(s) that the owner or operator selects to control as part 

of achieving the required emission reduction. Except as 

specified in paragraph (b)(11)(iii)(D) of this section, the 

owner or operator shall develop an emission profile for the vent 

to the control device that describes the characteristics of the 

vent stream at the inlet to the control device under either 

absolute or hypothetical peak-case conditions. The emissions 

profile shall be developed based on the applicable procedures 

described in paragraphs (b)(11)(iii)(A) through (C) of this 

section, as required by paragraphs (b)(11)(i) and (ii) of this 

section.

(A) Emissions profile by process. The emissions profile 

must consider all emission episodes that could contribute to the 

vent stack for a period of time that is sufficient to include 

all processes venting to the stack and shall consider production 

scheduling. The profile shall describe the HAP load to the 
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device that equals the highest sum of emissions from the 

episodes that can vent to the control device during the period 

of absolute peak-case conditions specified in paragraph 

(b)(11)(i)(A), (B), or (C) as appropriate. Emissions per episode 

shall be calculated using the procedures specified in paragraph 

(c)(2) of this section. When complying with paragraph 

(b)(11)(i)(B) of this section, emissions per episode shall be 

divided by the duration of the episode if the duration of the 

episode is longer than 1 hour.

(B) Emission profile by equipment. The emission profile 

must consist of emissions that meet or exceed the highest hourly 

HAP load that would be expected under actual processing 

conditions. The profile shall describe equipment configurations 

used to generate the emission events, volatility of materials 

processed in the equipment, and the rationale used to identify 

and characterize the emission events. The emissions may be based 

on using a compound more volatile than compounds actually used

in the process(es), and the emissions may be generated from all 

equipment in the process(es) or only selected equipment.

(C) Emission profile by capture and control device 

limitation. The emission profile shall consider the capture and 

control system limitations and the highest hourly emissions that 

can be routed to the control device, based on maximum flow rate 

and concentrations possible because of limitations on conveyance 
Page 152 of 267

and control equipment (e.g., fans, LEL alarms and safety 

bypasses).

(D) Exemptions. The owner or operator is not required to 

develop an emission profile under the circumstances described in 

paragraph (b)(11)(iii)(D)(1) or (2) of this section.

(1) If all process vents for a process are controlled using 

a control device or series of control devices that reduce HAP 

emissions by 98 percent or more, no other emission streams are 

vented to the control device when it is used to control 

emissions from the subject process, and the performance test is 

conducted over the entire batch cycle.

(2) If a control device is used to comply with the outlet 

concentration limit for process vent emission streams from a 

single process (but not necessarily all of the process vents 

from that process), no other emission streams are vented to the 

control device while it is used to control emissions from the 

subject process, and the performance test is conducted over the 

entire batch cycle.

(iv) Test duration. Three runs, at a minimum of 1 hour 

each, are required for performance testing. When complying with 

a percent reduction standard, each test run may be a maximum of 

either 24 hours or the duration of the longest batch controlled 

by the control device, whichever is shorter, and each run must 

include the same absolute or hypothetical peak-case conditions, 
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as defined in paragraph (b)(11)(i) or (ii) of this section. When 

complying with an outlet concentration limit, each run must 

include the same absolute or hypothetical peak-case conditions, 

as defined in paragraph (b)(11)(i) or (ii) of this section, and 

the duration of each run may not exceed the duration of the 

applicable peak-case condition.

(c) Initial compliance with process vent provisions. The 

owner or operator of an affected source shall demonstrate 

compliance with the process vent standards in §63.1362(b) using 

the procedures described in paragraphs (c)(1) through (3) of 

this section.

(1) Compliance with the process vent standards in 

§63.1362(b) shall be demonstrated in accordance with the 

provisions specified in paragraphs (c)(1)(i) through (viii) of 

this section.

(i) Initial compliance with the emission limit cutoffs in 

§63.1362(b)(2)(i) and (b)(4)(i) is demonstrated when the 

uncontrolled organic HAP emissions from the sum of all process 

vents within a process are less than or equal to 0.15 Mg/yr. 

Uncontrolled HAP emissions shall be determined using the 

procedures described in paragraph (c)(2) of this section.

(ii) Initial compliance with the emission limit cutoffs in 

§63.1362(b)(3)(i) and (b)(5)(i) is demonstrated when the 

uncontrolled HCl and Cl2 emissions from the sum of all process 
Page 154 of 267

vents within a process are less than or equal to 6.8 Mg/yr. 

Initial compliance with the emission limit cutoffs in 

§63.1362(b)(5)(ii) and (iii) is demonstrated when the 

uncontrolled HCl and Cl2 emissions are greater than or equal to 

6.8 Mg/yr or greater than or equal to 191 Mg/yr, respectively. 

Uncontrolled emissions shall be determined using the procedures 

described in paragraph (c)(2) of this section.

(iii) Initial compliance with the organic HAP percent 

reduction requirements specified in §63.1362(b)(2)(ii), (iii), 

and (b)(4)(ii) is demonstrated by determining controlled HAP 

emissions using the procedures described in paragraph (c)(3) of 

this section, determining uncontrolled HAP emissions using the 

procedures described in paragraph (c)(2) of this section, and 

calculating the applicable percent reduction. As an alternative, 

if the conditions specified in paragraph (b)(11)(iii)(D)(1) of 

this section are met, initial compliance may be demonstrated by 

showing the control device reduces emissions by 98 percent by 

weight or greater using the procedures specified in paragraph 

(c)(3) of this section.

(iv) Initial compliance with the HCl and Cl2 percent 

reduction requirements specified in §63.1362(b)(3)(ii), 

(b)(5)(ii), and (b)(5)(iii) is demonstrated by determining 

controlled emissions of HCl and Cl2 using the procedures 

described in paragraph (c)(3) of this section, determining 
Page 155 of 267

uncontrolled emissions of HCl and Cl2 using the procedures 

described in paragraph (c)(2) of this section, and calculating 

the applicable percent reduction.

(v) Initial compliance with the outlet concentration limits 

in §63.1362(b)(2)(iv)(A), (b)(3)(ii), (b)(4)(ii)(A), (b)(5)(ii) 

and (iii) is demonstrated when the outlet TOC or total organic 

HAP concentration is 20 ppmv or less and the outlet HCl and 

chlorine concentration is 20 ppmv or less. The owner or operator 

shall demonstrate compliance by fulfilling the requirements in 

paragraph (a)(6) of this section. If an owner or operator elects 

to develop an emissions profile by process as described in 

paragraph (b)(11)(iii)(A) of this section, uncontrolled 

emissions shall be determined using the procedures in paragraph 

(c)(2) of this section.

(vi) Initial compliance with the alternative standard in 

§63.1362(b)(6) is demonstrated by fulfilling the requirements in 

paragraph (a)(5) of this section.

(vii) Initial compliance when using a flare is demonstrated 

by fulfilling the requirements in paragraph (a)(3) of this 

section.

(viii) No initial compliance demonstration is required for 

control devices specified in §63.1362(l).

(2) Uncontrolled emissions. The owner or operator referred 

to from paragraphs (c)(1)(i) through (v) of this section shall 
Page 156 of 267

calculate uncontrolled emissions according to the procedures 

described in paragraph (c)(2)(i) or (ii) of this section, as 

appropriate.

(i) Emission estimation procedures. The owner or operator 

shall determine uncontrolled HAP emissions using emission 

measurements and/or calculations for each batch emission episode 

according to the engineering evaluation methodology in 

paragraphs (c)(2)(i)(A) through (H) of this section.

(A) Individual HAP partial pressures in multicomponent 

systems shall be determined in accordance with the methods 

specified in paragraphs (c)(2)(i)(A)(1) through (3) of this 

section. Chemical property data may be obtained from standard 

references.

(1) If the components are miscible in one another, use 

Raoult's law to calculate the partial pressures;

(2) If the solution is a dilute aqueous mixture, use 

Henry's law constants to calculate partial pressures;

(3) If Raoult's law or Henry's law are not appropriate or 

available, use any of the methods specified in paragraphs 

(c)(2)(i)(A) (3)(i) through (iii) of this section.

(i) Use experimentally obtained activity coefficients;

(ii) Use models such as the group-contribution models to 

predict activity coefficients;
Page 157 of 267

(iii) Assume the components of the system behave 

independently and use the summation of all vapor pressures from 

the HAP as the total HAP partial pressure;

(B) Charging or filling. Emissions from vapor displacement 

due to transfer of material to a vessel shall be calculated 

using Equation 9 of this subpart:

Where:

E = mass of HAP emitted

Pi = partial pressure of the individual HAP

V = volume of gas displaced from the vessel

R = ideal gas law constant

T = temperature of the vessel vapor space; absolute

MWi = molecular weight of the individual HAP

(C) Purging. Emissions from purging shall be calculated 

using Equation 10 of this subpart, except that for purge flow 

rates greater than 100 scfm, the mole fraction of HAP will be 

assumed to be 25 percent of the saturated value.

Where:

E = mass of HAP emitted
Page 158 of 267

V = purge flow rate at the temperature and pressure of the 

vessel vapor space

R = ideal gas law constant

T = temperature of the vessel vapor space; absolute

Pi = partial pressure of the individual HAP

Pj = partial pressure of individual condensable compounds 

(including HAP)

PT = pressure of the vessel vapor space

MWi = molecular weight of the individual HAP

t = time of purge

n = number of HAP compounds in the emission stream

m = number of condensable compounds (including HAP) in the 

emission stream.

(D) Heating. Emissions caused by heating the contents of a 

vessel to a temperature less than the boiling point shall be 

calculated using the procedures in either paragraph 

(c)(2)(i)(D)(1), (2), or (4) of this section, as appropriate. If 

the contents of a vessel are heated to the boiling point, 

emissions while boiling are assumed to be zero if the owner or 

operator is complying with the provisions in paragraph 

(d)(2)(i)(C)(3) of this section.

(1) If the final temperature to which the vessel contents 

are heated is lower than 50 K below the boiling point of the HAP 
Page 159 of 267

in the vessel, then emissions shall be calculated using 

Equations 11 through 14 of this subpart.

(i) The mass of HAP emitted per episode shall be calculated 

using Equation 11 of this subpart:

Where:

E = mass of HAP vapor displaced from the vessel being 

heated

(Pi)Tn = partial pressure of each HAP in the vessel 

headspace at initial (n = 1) and final (n = 2) temperatures

Pa1 = initial noncondensable gas pressure in the vessel, as 

calculated using Equation 13 of this subpart

Pa2 = final noncondensable gas pressure in the vessel, as 

calculated using Equation 13 of this subpart

ΔΗ = number of moles of noncondensable gas displaced, as 

calculated using Equation 12 of this subpart

MWHAP = The average molecular weight of HAP present in the 

vessel, as calculated using Equation 14 of this subpart:

n = number of HAP compounds in the displaced vapor

(ii) The moles of noncondensable gas displaced shall be 

calculated using Equation 12 of this subpart:
Page 160 of 267

Where:

ΔΗ = number of moles of noncondensable gas displaced

V = volume of free space in the vessel

R = ideal gas law constant

Pa1 = initial noncondensable gas pressure in the vessel, as 

calculated using Equation 13 of this subpart

Pa2 = final noncondensable gas pressure in the vessel, as 

calculated using Equation 13 of this subpart

T1 = initial temperature of vessel contents, absolute

T2 = final temperature of vessel contents, absolute

(iii) The initial and final pressure of the noncondensable 

gas in the vessel shall be calculated according to Equation 13 

of this subpart:

Where:

Pan = partial pressure of noncondensable gas in the vessel 

headspace at initial (n = 1) and final (n = 2) temperatures

Patm = atmospheric pressure

(Pj)Tn = partial pressure of each condensable volatile 

organic compound (including HAP) in the vessel headspace at the 

initial temperature (n = 1) and final (n = 2) temperature
Page 161 of 267

(iv) The average molecular weight of HAP in the displaced 

gas shall be calculated using Equation 14 of this subpart:

Where:

MWHAP = average molecular weight of HAP in the displaced gas

(Pi)Tn = partial pressure of each HAP in the vessel 

headspace at the initial (T1) and final (T2) temperatures

MWi = molecular weight of each HAP

n = number of HAP compounds in the emission stream

(2) If the vessel contents are heated to a temperature 

greater than 50 K below the boiling point, then emissions from 

the heating of a vessel shall be calculated as the sum of the 

emissions calculated in accordance with paragraphs 

(c)(2)(i)(D)(2)(i) and (ii) of this section.

(i) For the interval from the initial temperature to the 

temperature 50 K below the boiling point, emissions shall be 

calculated using Equation 11 of this subpart, where T2is the 

temperature 50 K below the boiling point.

(ii) For the interval from the temperature 50 K below the 

boiling point to the final temperature, emissions shall be 

calculated as the summation of emissions for each 5 K increment, 

where the emission for each increment shall be calculated using 

Equation 11 of this subpart. If the final temperature of the 
Page 162 of 267

heatup is lower than 5 K below the boiling point, the final 

temperature for the last increment shall be the final 

temperature of the heatup, even if the last increment is less 

than 5 K. If the final temperature of the heatup is higher than 

5 K below the boiling point, the final temperature for the last 

increment shall be the temperature 5 K below the boiling point, 

even if the last increment is less than 5 K.

(3) While boiling, the vessel must be operated with a 

properly operated process condenser. An initial demonstration 

that a process condenser is properly operated is required for 

vessels that operate process condensers without secondary 

condensers that are air pollution control devices. The owner or 

operator must either measure the condenser exhaust gas 

temperature and show it is less than the boiling point of the 

substance(s) in the vessel, or perform a material balance around 

the vessel and condenser to show that at least 99 percent of the 

material vaporized while boiling is condensed. Uncontrolled 

emissions are assumed to be zero under these conditions. The 

initial demonstration shall be conducted for all appropriate 

operating scenarios and documented in the Notification of 

Compliance Status report as specified in §63.1368(f).

(4)(i) As an alternative to the procedures described in 

paragraphs (c)(2)(i)(D)(1) and (2) of this section, emissions 

caused by heating a vessel to any temperature less than the 
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boiling point may be calculated using Equation 15 of this 

subpart.

Where:

E = mass of HAP vapor displaced from the vessel being 

heated

Navg = average gas space molar volume during the heating 

process, as calculated using Equation 16 of this subpart

PT = total pressure in the vessel

Pi,1 = partial pressure of the individual HAP compounds at T1

Pi,2 = partial pressure of the individual HAP compounds at T2

MWHAP = average molecular weight of the HAP compounds, as 

calculated using Equation 14 of this subpart

nHAP,1 = number of moles of total HAP in the vessel headspace 

at T1

nHAP,2 = number of moles of total HAP in the vessel headspace 

at T2

m = number of HAP compounds in the emission stream.

(ii) The average gas space molar volume during the heating 

process is calculated using Equation 16 of this subpart.
Page 164 of 267

Where:

Navg = average gas space molar volume during the heating 

process

V = volume of free space in vessel

PT = total pressure in the vessel

R = ideal gas law constant

T1 = initial temperature of the vessel contents, absolute

T2 = final temperature of the vessel contents, absolute

(iii) The difference in the number of moles of total HAP in 

the vessel headspace between the initial and final temperatures 

is calculated using Equation 17 of this subpart.

Where:

nHAP,2 = number of moles of total HAP in the vessel headspace 

at T2

nHAP,1 = number of moles of total HAP in the vessel headspace 

at T1

V = volume of free space in vessel

R = ideal gas law constant

T1 = initial temperature of the vessel contents, absolute

T2 = final temperature of the vessel contents, absolute

Pi,1 = partial pressure of the individual HAP compounds at T1

Pi,2 = partial pressure of the individual HAP compounds at T2
Page 165 of 267

n = number of HAP compounds in the emission stream.

(E) Depressurization. Emissions from depressurization shall 

be calculated using the procedures in paragraphs (c)(2)(i)(E)(1) 

through (5) of this section. Alternatively, the owner or 

operator may elect to calculate emissions from depressurization 

using the procedures in paragraph (c)(2)(i)(E)(6) of this 

section.

(1) The moles of HAP vapor initially in the vessel are 

calculated using Equation 18 of this subpart:

Where:

nHAP = moles of HAP vapor in the vessel

Pi = partial pressure of each HAP in the vessel vapor space

V = free volume in the vessel being depressurized

R = ideal gas law constant

T = absolute temperature in vessel

n = number of HAP compounds in the emission stream

(2) The initial and final moles of noncondensable gas 

present in the vessel are calculated using Equations 19 and 20 

of this subpart:

Where:
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n1 = initial number of moles of noncondensable gas in the 

vessel

n2 = final number of moles of noncondensable gas in the 

vessel

V = free volume in the vessel being depressurized

Pnc1 = initial partial pressure of the noncondensable gas, 

as calculated using Equation 21 of this subpart

Pnc2 = final partial pressure of the noncondensable gas, as 

calculated using Equation 22 of this subpart

R = ideal gas law constant

T = temperature, absolute

(3) The initial and final partial pressures of the 

noncondensable gas in the vessel are determined using Equations 

21 and 22 of this subpart.

Where:

Pnc1 = initial partial pressure of the noncondensable gas

Pnc2 = final partial pressure of the noncondensable gas

P1 = initial vessel pressure

P2 = final vessel pressure
Page 167 of 267

Pj* = vapor pressure of each condensable compound (including 

HAP) in the emission stream

xj = mole fraction of each condensable compound (including 

HAP) in the liquid phase

m = number of condensable compounds (including HAP) in the 

emission stream.

(4) The moles of HAP emitted during the depressurization 

are calculated by taking an approximation of the average ratio 

of moles of HAP to moles of noncondensable and multiplying by 

the total moles of noncondensables released during the 

depressurization, using Equation 23 of this subpart:

Where:

nHAP,e = moles of HAP emitted

nHAP,1 = moles of HAP vapor in vessel at the initial 

pressure, as calculated using Equation 18 of this subpart

nHAP,2 = moles of HAP vapor in vessel at the final pressure, 

as calculated using Equation 18 of this subpart

n1 = initial number of moles of noncondensable gas in the 

vessel, as calculated using Equation 19 of this subpart

n2 = final number of moles of noncondensable gas in the 

vessel, as calculated using Equation 19 of this subpart.
Page 168 of 267

(5) Use Equation 24 of this subpart to calculate the mass 

of HAP emitted:

Where:

E = mass of HAP emitted

nHAP,e = moles of HAP emitted, as calculated using Equation 

23 of this subpart

MWHAP = average molecular weight of the HAP as calculated 

using Equation 14 of this subpart

(6) As an alternative to the procedures in paragraphs 

(c)(2)(i)(E)(1) through (5) of this section, emissions from 

depressurization may be calculated using Equation 25 of this 

subpart:

Where:

V = free volume in vessel being depressurized

R = ideal gas law constant

T = temperature of the vessel, absolute

P1 = initial pressure in the vessel

P2 = final pressure in the vessel

Pi = partial pressure of the individual HAP compounds
Page 169 of 267

Pj = partial pressure of individual condensable VOC 

compounds (including HAP)

MWi = molecular weight of the individual HAP compounds

n = number of HAP compounds in the emission stream

m = number of condensable VOC compounds (including HAP) in

the emission stream

(F) Vacuum systems. Calculate emissions from vacuum systems 

using Equation 26 of this subpart:

Where:

E = mass of HAP emitted

PT = absolute pressure of receiving vessel or ejector outlet 

conditions, if there is no receiver

Pi = partial pressure of individual HAP at the receiver 

temperature or the ejector outlet conditions

Pj = partial pressure of individual condensable compounds 

(including HAP) at the receiver temperature or the ejector 

outlet conditions

La = total air leak rate in the system, mass/time

MWnc = molecular weight of noncondensable gas

t = time of vacuum operation
Page 170 of 267

MWHAP = average molecular weight of HAP in the emission 

stream, as calculated using Equation 14 of this subpart, with 

HAP partial pressures calculated at the temperature of the 

receiver or ejector outlet, as appropriate

n = number of HAP components in the emission stream

m = number of condensable compounds (including HAP) in the 

emission stream.

(G) Gas evolution. Emissions from gas evolution shall be 

calculated using Equation 10 of this subpart with V calculated 

using Equation 27 of this subpart:

Where:

V = volumetric flow rate of gas evolution

Wg = mass flow rate of gas evolution

R = ideal gas law constant

T = temperature at the exit, absolute

PT = vessel pressure

MWg = molecular weight of the evolved gas

(H) Air drying. Use Equation 28 of this subpart to 

calculate emissions from air drying:

Where:
Page 171 of 267

E = mass of HAP emitted

B = mass of dry solids

PS1 = HAP in material entering dryer, weight percent

PS2 = HAP in material exiting dryer, weight percent.

(ii) Engineering assessments. The owner or operator shall 

conduct an engineering assessment to determine uncontrolled HAP 

emissions for each emission episode that is not due to vapor 

displacement, purging, heating, depressurization, vacuum 

systems, gas evolution, or air drying. For a given emission 

episode caused by any of these seven types of activities, the 

owner or operator also may request approval to determine 

uncontrolled HAP emissions based on an engineering assessment. 

Except as specified in paragraph (c)(2)(ii)(A) of this section, 

all data, assumptions, and procedures used in the engineering 

assessment shall be documented in the Precompliance plan in 

accordance with §63.1367(b). An engineering assessment includes, 

but is not limited to, the information and procedures described 

in paragraphs (c)(2)(ii)(A) through (D) of this section.

(A) Test results, provided the tests are representative of 

current operating practices at the process unit. For process 

vents without variable emission stream characteristics, an 

engineering assessment based on the results of a previous test 

may be submitted in the Notification of Compliance Status report 

instead of the Precompliance plan. Results from a previous test 
Page 172 of 267

of process vents with variable emission stream characteristics 

will be acceptable in place of values estimated using the 

procedures specified in paragraph (c)(2)(i) of this section if 

the test data show a greater than 20 percent discrepancy between 

the test value and the estimated value, and the results of the 

engineering assessment shall be included in the Notification of 

Compliance Status report. For other process vents with variable 

emission stream characteristics, engineering assessments based 

on the results of a previous test must be submitted in the 

Precompliance plan. For engineering assessments based on new 

tests, the owner or operator must comply with the test 

notification requirements in §63.1368(m), and the results of the 

engineering assessment may be submitted in the Notification of 

Compliance Status report rather than the Precompliance plan.

(B) Bench-scale or pilot-scale test data representative of 

the process under representative operating conditions.

(C) Maximum flow rate, HAP emission rate, concentration, or 

other relevant parameter specified or implied within a permit 

limit applicable to the process vent.

(D) Design analysis based on accepted chemical engineering 

principles, measurable process parameters, or physical or 

chemical laws or properties. Examples of analytical methods 

include, but are not limited to:
Page 173 of 267

(1) Use of material balances based on process stoichiometry 

to estimate maximum organic HAP concentrations;

(2) Estimation of maximum flow rate based on physical 

equipment design such as pump or blower capacities; and

(3) Estimation of HAP concentrations based on saturation 

conditions.

(3) Controlled emissions. Except for condensers, the owner 

or operator shall determine controlled emissions using the 

procedures in either paragraph (c)(3)(i) or (ii) of this 

section, as applicable. For condensers, controlled emissions 

shall be calculated using the emission estimation equations

described in paragraph (c)(3)(iii) of this section. The owner or 

operator is not required to calculate controlled emissions from 

devices described in paragraph (a)(4) of this section or from 

flares for which compliance is demonstrated in accordance with 

paragraph (a)(3) of this section. If the owner or operator is 

complying with an outlet concentration standard and the control 

device uses supplemental gases, the outlet concentrations shall 

be corrected in accordance with the procedures described in 

paragraph (a)(7) of this section.

(i) Small control devices, except condensers. Controlled 

emissions for each process vent that is controlled using a small 

control device, except for a condenser, shall be determined by 

using the design evaluation described in paragraph (c)(3)(i)(A) 
Page 174 of 267

of this section, or by conducting a performance test in 

accordance with paragraph (c)(3)(ii) of this section.

(A) Design evaluation. The design evaluation shall include 

documentation demonstrating that the control device being used 

achieves the required control efficiency under absolute or 

hypothetical peak-case conditions, as determined from the 

emission profile described in paragraph (b)(11)(iii) of this 

section. The control efficiency determined from this design 

evaluation shall be applied to uncontrolled emissions to 

estimate controlled emissions. The documentation must be 

conducted in accordance with the provisions in paragraph (a)(1) 

of this section. The design evaluation shall also include the 

value(s) and basis for the parameter(s) monitored under 

§63.1366.

(B) Whenever a small control device becomes a large control 

device, the owner or operator must comply with the provisions in 

paragraph (c)(3)(ii) of this section and submit the test report 

in the next Periodic report.

(ii) Large control devices, except condensers. Controlled 

emissions for each process vent that is controlled using a large 

control device, except for a condenser, shall be determined by 

applying the control efficiency of the large control device to 

the estimated uncontrolled emissions. The control efficiency 

shall be determined by conducting a performance test on the 
Page 175 of 267

control device as described in paragraphs (c)(3)(ii)(A) through 

(C) of this section, or by using the results of a previous 

performance test as described in paragraph (c)(3)(ii)(D) of this 

section. If the control device is intended to control only HCl 

and chlorine, the owner or operator may assume the control 

efficiency of organic HAP is 0 percent. If the control device is 

intended to control only organic HAP, the owner or operator may 

assume the control efficiency for HCl and chlorine is 0 percent.

(A) Performance test measurements shall be conducted at 

both the inlet and outlet of the control device for TOC, total 

organic HAP, and total HCl and chlorine, as applicable, using 

the test methods and procedures described in paragraph (b) of 

this section. Concentrations shall be calculated from the data 

obtained through emission testing according to the procedures in 

paragraph (a)(2) of this section.

(B) Performance testing shall be conducted under absolute 

or hypothetical peak-case conditions, as defined in paragraphs 

(b)(11)(i) and (ii) of this section.

(C) The owner or operator may elect to conduct more than 

one performance test on the control device for the purpose of 

establishing more than one operating condition at which the 

control device achieves the required control efficiency.

(D) The owner or operator is not required to conduct a 

performance test for any control device for which a previous 
Page 176 of 267

performance test was conducted, provided the test was conducted 

using the same procedures specified in paragraphs (b)(1) through 

(11) of this section over conditions typical of the absolute or 

hypothetical peak-case, as defined in paragraphs (b)(11)(i) and 

(ii) of this section. The results of the previous performance 

test shall be used to demonstrate compliance.

(iii) Condensers. The owner or operator using a condenser 

as a control device shall determine controlled emissions for 

each batch emission episode according to the engineering 

methodology in paragraphs (c)(3)(iii)(A) through (G) of this 

section. The owner or operator must establish the maximum outlet 

gas temperature and calculate the controlled emissions using 

this temperature in the applicable equation. Individual HAP 

partial pressures shall be calculated as specified in paragraph 

(c)(2)(i) of this section.

(A) Emissions from vapor displacement due to transfer of 

material to a vessel shall be calculated using Equation 9 of 

this subpart with T set equal to the temperature of the receiver 

and the HAP partial pressures determined at the temperature of 

the receiver.

(B) Emissions from purging shall be calculated using 

Equation 10 of this subpart with T set equal to the temperature 

of the receiver and the HAP partial pressures determined at the 

temperature of the receiver.
Page 177 of 267

(C) Emissions from heating shall be calculated using 

Equation 29 of this subpart. In Equation 29 of this subpart, Δη 

is equal to the number of moles of noncondensable displaced from 

the vessel, as calculated using Equation 12 of this subpart. In 

Equation 29 of this subpart, the HAP average molecular weight 

shall be calculated using Equation 14 with the HAP partial 

pressures determined at the temperature of the receiver.

Where:

E = mass of HAP emitted

Δη = moles of noncondensable gas displaced

PT = pressure in the receiver

Pi = partial pressure of the individual HAP at the receiver 

temperature

Pj = partial pressure of the individual condensable VOC 

(including HAP) at the receiver temperature

n = number of HAP compounds in the emission stream

MWHAP = the average molecular weight of HAP in vapor exiting 

the receiver, as calculated using Equation 14 of this subpart

m = number of condensable VOC (including HAP) in the 

emission stream
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(D)(1) Emissions from depressurization shall be calculated 

using Equation 30 of this subpart.

Where:

E = mass of HAP vapor emitted

Vnc1 = initial volume of noncondensable in the vessel, 

corrected to the final pressure, as calculated using Equation 31 

of this subpart

Vnc2 = final volume of noncondensable in the vessel, as 

calculated using Equation 32 of this subpart

Pi = partial pressure of each individual HAP at the receiver 

temperature

Pj = partial pressure of each condensable VOC (including 

HAP) at the receiver temperature

PT = receiver pressure

T = temperature of the receiver, absolute

R = ideal gas law constant

MWHAP = the average molecular weight of HAP calculated using 

Equation 14 of this subpart with partial pressures determined at 

the receiver temperature

n = number of HAP compounds in the emission stream
Page 179 of 267

m = number of condensable VOC (including HAP) in the 

emission stream

(2) The initial and final volumes of noncondensable gas 

present in the vessel, adjusted to the pressure of the receiver, 

are calculated using Equations 31 and 32 of this subpart.

Where:

Vnc1 = initial volume of noncondensable gas in the vessel

Vnc2 = final volume of noncondensable gas in the vessel

V = free volume in the vessel being depressurized

Pnc1 = initial partial pressure of the noncondensable gas, 

as calculated using Equation 33 of this subpart

Pnc2 = final partial pressure of the noncondensable gas, as 

calculated using Equation 34 of this subpart

PT = pressure of the receiver

(3) Initial and final partial pressures of the 

noncondensable gas in the vessel are determined using Equations 

33 and 34 of this subpart.

Where:

Pnc1 = initial partial pressure of the noncondensable gas in 

the vessel
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Pnc2 = final partial pressure of the noncondensable gas in 

the vessel

P1 = initial vessel pressure

P2 = final vessel pressure

Pj = partial pressure of each condensable VOC (including 

HAP) in the vessel

m = number of condensable VOC (including HAP) in the 

emission stream

(E) Emissions from vacuum systems shall be calculated using 

Equation 26 of this subpart.

(F) Emissions from gas evolution shall be calculated using 

Equation 8 with V calculated using Equation 27 of this subpart, 

T set equal to the receiver temperature, and the HAP partial 

pressures determined at the receiver temperature. The term for 

time, t, in Equation 10 of this subpart is not needed for the 

purposes of this calculation.

(G) Emissions from air drying shall be calculated using 

Equation 9 of this subpart with V equal to the air flow rate and 

Pidetermined at the receiver temperature.

(d) Initial compliance with storage vessel provisions. The 

owner or operator of an existing or new affected source shall 

demonstrate initial compliance with the storage vessel standards 

in §63.1362(c)(2) through (4) by fulfilling the requirements in 

either paragraph (d)(1), (2), (3), (4), (5), or (6) of this 
Page 181 of 267

section, as applicable. The owner or operator shall demonstrate 

initial compliance with the planned routine maintenance 

provision in §63.1362(c)(5) by fulfilling the requirements in 

paragraph (d)(7) of this section.

(1) Percent reduction requirement for control devices. If 

the owner or operator equips a Group 1 storage vessel with a 

closed vent system and control device, the owner or operator 

shall demonstrate initial compliance with the percent reduction 

requirement of §63.1362(c)(2)(iv)(A) or (c)(3) either by 

calculating the efficiency of the control device using 

performance test data as specified in paragraph (d)(1)(i) of 

this section, or by preparing a design evaluation as specified 

in paragraph (d)(1)(ii) of this section.

(i) Performance test option. If the owner or operator 

elects to demonstrate initial compliance based on performance 

test data, the efficiency of the control device shall be 

calculated as specified in paragraphs (d)(1)(i)(A) through (D) 

of this section.

(A) At the reasonably expected maximum filling rate, 

Equations 35 and 36 of this subpart shall be used to calculate 

the mass rate of total organic HAP or TOC at the inlet and 

outlet of the control device.
Page 182 of 267

Where:

Cij, Coj = concentration of sample component j of the gas 

stream at the inlet and outlet of the control device, 

respectively, dry basis, ppmv

Ei, Eo = mass rate of total organic HAP or TOC at the inlet 

and outlet of the control device, respectively, dry basis, kg/hr

Mij, Moj = molecular weight of sample component j of the gas 

stream at the inlet and outlet of the control device, 

respectively, g/gmole

Qi, Qo = flow rate of gas stream at the inlet and outlet of 

the control device, respectively, dscmm

K2 = constant, 2.494 × 10−6(parts per million)−1(gram-mole 

per standard cubic meter) (kilogram/gram) (minute/hour), where 

standard temperature is 20 °C.

(B) The percent reduction in total organic HAP or TOC shall 

be calculated using Equation 37 of this subpart:

Where:
Page 183 of 267

R = control efficiency of control device, percent

Ei = mass rate of total organic HAP or TOC at the inlet to 

the control device as calculated under paragraph (d)(l)(i)(A) of 

this section, kilograms organic HAP per hour

Eo = mass rate of total organic HAP or TOC at the outlet of 

the control device, as calculated under paragraph (d)(1)(i)(A) 

of this section, kilograms organic HAP per hour.

(C) A performance test is not required to be conducted if 

the control device used to comply with §63.1362(c) (storage tank 

provisions) is also used to comply with §63.1362(b) (process 

vent provisions), provided compliance with §63.1362(b) is 

demonstrated in accordance with paragraph (c) of this section 

and the demonstrated percent reduction is equal to or greater 

than 95 percent.

(D) A performance test is not required for any control 

device for which a previous test was conducted, provided the 

test was conducted using the same procedures specified in 

paragraph (b) of this section.

(ii) Design evaluation option. If the owner or operator 

elects to demonstrate initial compliance by conducting a design 

evaluation, the owner or operator shall prepare documentation in 

accordance with the design evaluation provisions in paragraph 

(a)(1) of this section, as applicable. The design evaluation 

shall demonstrate that the control device being used achieves 
Page 184 of 267

the required control efficiency when the storage vessel is 

filled at the reasonably expected maximum filling rate.

(2) Outlet concentration requirement for control devices. 

If the owner or operator equips a Group 1 storage vessel with a 

closed vent system and control device, the owner or operator 

shall demonstrate initial compliance with the outlet 

concentration requirements of §63.1362(c)(2)(iv)(B) or (c)(3) by 

fulfilling the requirements of paragraph (a)(6) of this section.

(3) Floating roof. If the owner or operator equips a Group 

1 storage vessel with a floating roof to comply with the 

provisions in §63.1362(c)(2) or (c)(3), the owner or operator 

shall demonstrate initial compliance by complying with the 

procedures described in paragraphs (d)(3)(i) and (ii) of this 

section.

(i) Comply with §63.119(b), (c), or (d) of subpart G of 

this part, as applicable, with the differences specified in 

§63.1362(d)(2)(i) through (iii).

(ii) Comply with the procedures described in §63.120(a), 

(b), or (c), as applicable, with the differences specified in 

paragraphs (d)(3)(ii)(A) through (C) of this section.

(A) When the term “storage vessel” is used in §63.120, the 

definition of the term “storage vessel” in §63.1361 shall apply 

for the purposes of this subpart.
Page 185 of 267

(B) When the phrase “the compliance date specified in 

§63.100 of subpart F of this part” is referred to in §63.120, 

the phrase “the compliance date specified in §63.1364” shall 

apply for the purposes of this subpart.

(C) When the phrase “the maximum true vapor pressure of the 

total organic HAP in the stored liquid falls below the values 

defining Group 1 storage vessels specified in Table 5 or Table 6 

of this subpart” is referred to in §63.120(b)(1)(iv), the phrase 

“the maximum true vapor pressure of the total organic HAP in the 

stored liquid falls below the values defining Group 1 storage 

vessels specified in §63.1361” shall apply for the purposes of 

this subpart.

(4) Flares. If the owner or operator controls the emissions 

from a Group 1 storage vessel with a flare, initial compliance 

is demonstrated by fulfilling the requirements in paragraph 

(a)(3) of this section.

(5) Exemptions from initial compliance. No initial 

compliance demonstration is required for control devices 

specified in paragraph (a)(4) of this section.

(6) Initial compliance with alternative standard. If the 

owner or operator equips a Group 1 storage vessel with a closedvent system and control device, the owner or operator shall 

demonstrate initial compliance with the alternative standard in 
Page 186 of 267

§63.1362(c)(4) by fulfilling the requirements of paragraph 

(a)(5) of this section.

(7) Planned routine maintenance. The owner or operator 

shall demonstrate initial compliance with the planned routine 

maintenance provisions of §63.1362(c)(5) by including the 

anticipated periods of planned routine maintenance for the first 

reporting period in the Notification of Compliance Status report 

as specified in §63.1368(f).

(e) Initial compliance with wastewater provisions. The 

owner or operator shall demonstrate initial compliance with the 

wastewater requirements by complying with the applicable 

provisions in §63.145, except that the owner or operator need 

not comply with the requirement to determine visible emissions 

that is specified in §63.145(j)(1), and references to compounds 

in Table 8 of subpart G of this part are not applicable for the 

purposes of this subpart. When §63.145(i) refers to Method 18 of 

40 CFR part 60, appendix A–6, the owner or operator may use any 

method specified in §63.1362(d)(12) to demonstrate initial 

compliance with this subpart.

(f) Initial compliance with the bag dump and product dryer 

provisions. Compliance with the particulate matter concentration 

limits specified in §63.1362(e) is demonstrated when the 

concentration of particulate matter is less than 0.01 gr/dscf, 
Page 187 of 267

as measured using the method described in paragraph (b)(7) of 

this section.

(g) Initial compliance with the pollution prevention 

alternative standard. The owner or operator shall demonstrate 

initial compliance with §63.1362(g)(2) and (3) for a PAI process 

unit by preparing the demonstration summary in accordance with 

paragraph (g)(1) of this section and by calculating baseline and 

target annual HAP and VOC factors in accordance with paragraphs 

(g)(2) and (3) of this section. To demonstrate initial 

compliance with §63.1362(g)(3), the owner or operator must also 

comply with the procedures for add-on control devices that are 

specified in paragraph (g)(4) of this section.

(1) Demonstration summary. The owner or operator shall 

prepare a pollution prevention demonstration summary that shall 

contain, at a minimum, the information in paragraphs (g)(1)(i) 

through (iii) of this section. The demonstration summary shall 

be included in the Precompliance report as specified in 

§63.1368(e)(4).

(i) Descriptions of the methodologies and forms used to 

measure and record consumption of HAP and VOC compounds.

(ii) Descriptions of the methodologies and forms used to 

measure and record production of the product(s).

(iii) Supporting documentation for the descriptions 

provided in accordance with paragraphs (g)(1)(i) and (ii) of 
Page 188 of 267

this section including, but not limited to, operator log sheets 

and copies of daily, monthly, and annual inventories of 

materials and products. The owner or operator must show how this 

documentation will be used to calculate the annual factors 

required in §63.1366(f)(1).

(2) Baseline factors. The baseline HAP and VOC factors 

shall be calculated by dividing the consumption of total HAP and 

total VOC by the production rate, per process, for the first 3-

year period in which the process was operational, beginning no 

earlier than the period consisting of the 1987 through 1989 

calendar years. Alternatively, for a process that has been 

operational for less than 3 years, but more than 1 year, the 

baseline factors shall be established for the time period from 

startup of the process until the present.

(3) Target annual factors. The owner or operator must 

calculate target annual factors in accordance with either 

paragraph (g)(3)(i) or (ii) of this section.

(i) To demonstrate initial compliance with §63.1362(g)(2), 

the target annual HAP factor must be equal to or less than 15 

percent of the baseline HAP factor. For each reduction in a HAP 

that is also a VOC, the target annual VOC factor must be lower 

than the baseline VOC factor by an equivalent amount on a mass 

basis. For each reduction in a HAP that is not a VOC, the target 
Page 189 of 267

annual factor must be equal to or less than the baseline VOC 

factor.

(ii) To demonstrate initial compliance with 

§63.1362(g)(3)(i), the target annual HAP and VOC factors must be 

calculated as specified in paragraph (g)(3)(i) of this section, 

except that when “15 percent” is referred to in paragraph 

(g)(3)(i) of this section, “50 percent” shall apply for the 

purposes of this paragraph.

(4) Requirements for add-on control devices. Initial 

compliance with the requirements for add-on control devices in 

§63.1362(g)(3)(ii) is demonstrated when the requirements in 

paragraphs (g)(4)(i) through (iii) of this section are met.

(i) The yearly reductions associated with add-on controls 

that meet the criteria of §63.1362(g)(3)(ii)(A) through (D), 

must be equal to or greater than the amounts calculated using 

Equations 38 and 39 of this subpart:

Where:

HAPreduced = the annual HAP emissions reduction required by 

add-on controls, kg/yr

HFbase = the baseline HAP factor, kg HAP consumed/kg product

RP2 = the fractional reduction in the annual HAP factor 

achieved using pollution prevention where RP2is ≥0.5
Page 190 of 267

VOCreduced = required VOC emission reduction from add-on 

controls, kg/yr

VFbase = baseline VOC factor, kg VOC emitted/kg production

VFP2 = reduction in VOC factor achieved by pollution 

prevention, kg VOC emitted/kg production

VFannual = target annual VOC factor, kg VOC emitted/kg 

production

Mprod = production rate, kg/yr

(ii) Demonstration that the criteria in 

§63.1362(g)(3)(ii)(A) through (D) are met shall be accomplished 

through a description of the control device and of the material 

streams entering and exiting the control device.

(iii) The annual reduction achieved by the add-on control 

shall be quantified using the methods described in paragraph (c)

of this section.

(h) Compliance with emissions averaging provisions. An 

owner or operator shall demonstrate compliance with the 

emissions averaging provisions of §63.1362(h) by fulfilling the 

requirements of paragraphs (h)(1) through (6) of this section.

(1) The owner or operator shall develop and submit for 

approval an Emissions Averaging Plan containing all the 

information required in §63.1367(d). The Emissions Averaging 

Plan shall be submitted no later than 18 months prior to the 

compliance date of the standard. The Administrator shall 
Page 191 of 267

determine within 120 calendar days whether the Emissions 

Averaging Plan submitted by sources using emissions averaging 

presents sufficient information. The Administrator shall either 

approve the Emissions Averaging Plan, request changes, or 

request that the owner or operator submit additional 

information. Once the Administrator receives sufficient 

information, the Administrator shall approve, disapprove, or 

request changes to the plan within 120 days. If the Emissions 

Averaging Plan is disapproved, the owner or operator must still 

be in compliance with the standard by the compliance date.

(2) For all points included in an emissions average, the 

owner or operator shall comply with the procedures that are 

specified in paragraphs (h)(2)(i) through (v) of this section.

(i) Calculate and record monthly debits for all Group 1 

emission points that are controlled to a level less stringent 

than the standard for those emission points. Equations in 

paragraph (h)(5) of this section shall be used to calculate 

debits.

(ii) Calculate and record monthly credits for all Group 1 

and Group 2 emission points that are overcontrolled to 

compensate for the debits. Equations in paragraph (h)(6) of this 

section shall be used to calculate credits. All process vent, 

storage vessel, and wastewater emission points except those 
Page 192 of 267

specified in §63.1362(h)(1) through (6) may be included in the 

credit calculation.

(iii) Demonstrate that annual credits calculated according 

to paragraph (h)(6) of this section are greater than or equal to 

debits calculated according to paragraph (h)(5) of this section 

for the same annual compliance period. The initial demonstration 

in the Emissions Averaging Plan or operating permit application 

that credit-generating emission points will be capable of 

generating sufficient credits to offset the debit-generating 

emission points shall be made under representative operating 

conditions. After the compliance date, actual operating data 

shall be used for all debit and credit calculations.

(iv) Demonstrate that debits calculated for a quarterly (3-

month) period according to paragraph (h)(5) of this section are 

not more than 1.30 times the credits for the same period 

calculated according to paragraph (h)(6) of this section. 

Compliance for the quarter shall be determined based on the 

ratio of credits and debits from that quarter, with 30 percent 

more debits than credits allowed on a quarterly basis.

(v) Record and report quarterly and annual credits and 

debits as required in §§63.1367(d) and 63.1368(d).

(3) Credits and debits shall not include emissions during 

periods of malfunction. Credits and debits shall not include 
Page 193 of 267

periods of startup and shutdown for continuous 

processes.[Reserved]

(4) During periods of monitoring excursions, credits and 

debits shall be adjusted as specified in paragraphs (h)(4)(i) 

through (iii) of this section.

(i) No credits shall be assigned to the credit-generating 

emission point.

(ii) Maximum debits shall be assigned to the debitgenerating emission point.

(iii) The owner or operator may demonstrate to the 

Administrator that full or partial credits or debits should be 

assigned using the procedures in §63.150(l) of subpart G of this 

part.

(5) Debits are generated by the difference between the 

actual emissions from a Group 1 emission point that is 

uncontrolled or controlled to a level less stringent than the 

applicable standard and the emissions allowed for the Group 1 

emission point. Debits shall be calculated in accordance with 

the procedures specified in paragraphs (h)(5)(i) through (iv) of 

this section.

(i) Source-wide debits shall be calculated using Equation 

40 of this subpart.

Debits and all terms of Equation 40 of this subpart are in 

units of Mg/month
Page 194 of 267

Where:

EPViU = uncontrolled emissions from process i calculated 

according to the procedures specified in paragraph (h)(5)(ii) of 

this section

EPViA = actual emissions from each Group 1 process i that is 

uncontrolled or is controlled to a level less stringent than the 

applicable standard. EPViA is calculated using the procedures in 

paragraph (h)(5)(ii) of this section

ESiU = uncontrolled emissions from storage vessel i 

calculated according to the procedures specified in paragraph 

(h)(5)(iii) of this section

ESiA = actual emissions from each Group 1 storage vessel i 

that is uncontrolled or is controlled to a level less stringent 

than the applicable standard. ESiA is calculated using the 

procedures in paragraph (h)(5)(iii) of this section

EWWiC = emissions from each Group 1 wastewater stream i if 

the standard had been applied to the uncontrolled emissions. 

EWWiC is calculated using the procedures in paragraph (h)(5)(iv) 

of this section

EWWiA = actual emissions from each Group 1 wastewater stream 

i that is uncontrolled or is controlled to a level less 
Page 195 of 267

stringent than the applicable standard. EWWiA is calculated using 

the procedures in paragraph (h)(5)(iv) of this section

n = the number of emission points being included in the 

emissions average; the value of n is not necessarily the same 

for process vents, storage tanks, and wastewater

(ii) Emissions from process vents shall be calculated in 

accordance with the procedures specified in paragraphs 

(h)(5)(ii)(A) through (C) of this section.

(A) Except as provided in paragraph (h)(5)(ii)(C) of this 

section, uncontrolled emissions for process vents shall be 

calculated using the procedures that are specified in paragraph 

(c)(2) of this section.

(B) Except as provided in paragraph (h)(5)(ii)(C) of this 

section, actual emissions for process vents shall be calculated 

using the procedures specified in paragraphs (c)(2) and (c)(3) 

of this section, as applicable.

(C) As an alternative to the procedures described in 

paragraphs (h)(5)(ii)(A) and (B) of this section, for continuous 

processes, uncontrolled and actual emissions may be calculated 

by the procedures described in §63.150(g)(2) of subpart G of 

this part. For purposes of complying with this paragraph, a 90 

percent reduction shall apply instead of the 98 percent 

reduction in §63.150(g)(2)(iii) of subpart G of this part, and 

the term “process condenser” shall apply instead of the term 
Page 196 of 267

“recovery device” in §63.150(g)(2) for the purposes of this 

subpart.

(iii) Uncontrolled emissions from storage vessels shall be 

calculated in accordance with the procedures described in 

paragraph (d)(1) of this section. Actual emissions from storage 

vessels shall be calculated using the procedures specified in 

§63.150(g)(3)(ii), (iii), or (iv) of subpart G of this subpart, 

as appropriate, except that when §63.150(g)(3)(ii)(B) refers to 

the procedures in §63.120(d) for determining percent reduction 

for a control device, §63.1365(d)(2) or (3) shall apply for the 

purposes of this subpart.

(iv) Emissions from wastewater shall be calculated using 

the procedures specified in §63.150(g)(5) of subpart G of this 

part.

(6) Credits are generated by the difference between 

emissions that are allowed for each Group 1 and Group 2 emission 

point and the actual emissions from that Group 1 or Group 2 

emission point that have been controlled after November 15, 1990 

to a level more stringent than what is required in this subpart 

or any other State or Federal rule or statute. Credits shall be 

calculated in accordance with the procedures specified in 

paragraphs (h)(6)(i) through (v) of this section.

(i) Source-wide credits shall be calculated using Equation 

41 of this subpart. Credits and all terms in Equation 41 of this 
Page 197 of 267

subpart are in units of Mg/month, the baseline date is November 

15, 1990, the terms consisting of a constant multiplied by the 

uncontrolled emissions are the emissions from each emission 

point subject to the standards in §63.1362(b) and (c) that is 

controlled to a level more stringent than the standard.

Where:

EPV1iU = uncontrolled emissions from each Group 1 process i 

calculated according to the procedures in paragraph 

(h)(6)(iii)(A) of this section

EPV1iA = actual emissions from each Group 1 process i that 

is controlled to a level more stringent than the applicable 

standard. EPV1iA is calculated according to the procedures in 

paragraph (h)(6)(iii)(B) of this section

EPV2iB = emissions from each Group 2 process i at the 

baseline date. EPV2iB is calculated according to the procedures 

in paragraph (h)(6)(iii)(C) of this section

EPV2iA = actual emissions from each Group 2 process i that 

is controlled. EPV2iA is calculated according to the procedures 

in paragraph (h)(6)(iii)(C) of this section
Page 198 of 267

ES1iU = uncontrolled emissions from each Group 1 storage 

vessel i calculated according to the procedures in paragraph 

(h)(6)(iv) of this section

ES1iA = actual emissions from each Group 1 storage vessel i 

that is controlled to a level more stringent that the applicable 

standard. ES1iA is calculated according to the procedures in 

paragraph (h)(6)(iv) of this section

ES2iB = emissions from each Group 2 storage vessel i at the 

baseline date. ES2iB is calculated according to the procedures in 

paragraph (h)(6)(iv) of this section

ES2iA = actual emissions from each Group 2 storage vessel i 

that is controlled. ES2iA is calculated according to the 

procedures in paragraph (h)(6)(iv) of this section

EWW1iC = emissions from each Group 1 wastewater stream i if 

the standard had been applied to the uncontrolled emissions. 

EWW1iC is calculated according to the procedures in paragraph 

(h)(6)(v) of this section

EWW1iA = emissions from each Group 1 wastewater stream i 

that is controlled to a level more stringent that the applicable 

standard. EWW1iA is calculated according to the procedures in 

paragraph (h)(6)(v) of this section

EWW2iB = emissions from each Group 2 wastewater stream i at 

the baseline date. EWW2iB is calculated according to the 

procedures in paragraph (h)(6)(v) of this section
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EWW2iA = actual emissions from each Group 2 wastewater 

stream i that is controlled. EWW2iA is calculated according to 

the procedures in paragraph (h)(6)(v) of this section

n = number of Group 1 emission points that are included in 

the emissions average. The value of n is not necessarily the 

same for process vents, storage tanks, and wastewater

m = number of Group 2 emission points included in the 

emissions average. The value of m is not necessarily the same 

for process vents, storage tanks, and wastewater

D = discount factor equal to 0.9 for all credit-generating 

emission points except those controlled by a pollution 

prevention measure, which will not be discounted

(ii) For an emission point controlled using a pollution 

prevention measure, the nominal efficiency for calculating 

credits shall be as determined as described in §63.150(j) of 

subpart G of this part.

(iii) Emissions from process vents shall be calculated in 

accordance with the procedures specified in paragraphs 

(h)(6)(iii)(A) through (C) of this section.

(A) Uncontrolled emissions from Group 1 process vents shall 

be calculated according to the procedures in paragraph 

(h)(5)(ii)(A) or (C) of this section.

(B) Actual emissions from Group 1 process vents with a 

nominal efficiency greater than the applicable standard or a 
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pollution prevention measure that achieves reductions greater 

than the applicable standard shall be calculated using Equation 

42 of this subpart:

Where:

EPV1iA = actual emissions from each Group 1 process i that 

is controlled to a level more stringent than the applicable 

standard

EPV1iU = uncontrolled emissions from each Group 1 process i

Neff = nominal efficiency of control device or pollution 

prevention measure, percent

(C) Baseline and actual emissions from Group 2 process 

vents shall be calculated according to the procedures in 

§63.150(h)(2)(iii) and (iv) with the following modifications:

(1) The term “90 percent reduction” shall apply instead of 

the term “98 percent reduction”; and

(2) When the phrase “paragraph (g)(2)” is referred to in 

§63.150(h)(2)(iii) and (iv), the provisions in paragraph 

(h)(5)(ii) of this section shall apply for the purposes of this 

subpart.

(iv) Uncontrolled emissions from storage vessels shall be 

calculated according to the procedures described in paragraph 

(d)(1) of this section. Actual and baseline emissions from 

storage tanks shall be calculated according to the procedures 
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specified in §63.150(h)(3) of subpart G of this part, except 

when §63.150(h)(3) refers to §63.150(g)(3)(i), paragraph (d)(1) 

of this section shall apply for the purposes of this subpart.

(v) Emissions from wastewater shall be calculated using the 

procedures in §63.150(h)(5) of subpart G of this part.

§63.1366 Monitoring and inspection requirements.

(a) To provide evidence of continued compliance with the 

standard, the owner or operator of any existing or new affected 

source shall install, operate, and maintain monitoring devices 

as specified in this section. During the initial compliance 

demonstration, maximum or minimum operating parameter levels, or 

other design and operating characteristics, as appropriate, 

shall be established for emission sources that will indicate the 

source is in compliance. Test data, calculations, or information 

from the evaluation of the control device design, as applicable, 

shall be used to establish the operating parameter level or 

characteristic.

(b) Monitoring for control devices —(1) Parameters to 

monitor. Except as specified in paragraph (b)(1)(i) of this 

section, for each control device, the owner or operator shall 

install and operate monitoring devices and operate within the 

established parameter levels to ensure continued compliance with 

the standard. Monitoring parameters are specified for control 
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scenarios in paragraphs (b)(1)(ii) through (xii) of this 

section, and are summarized in Table 3 of this subpart.

(i) Periodic verification. For control devices that control 

vent streams containing total HAP emissions less than 0.91 

Mg/yr, before control, monitoring shall consist of a periodic 

verification that the device is operating properly. This 

verification shall include, but not be limited to, a daily or 

more frequent demonstration that the unit is working as designed 

and may include the daily measurements of the parameters 

described in paragraphs (b)(1)(ii) through (xii) of this 

section. This demonstration shall be included in the 

Precompliance plan, to be submitted 6 months prior to the 

compliance date of the standard.

(ii) Scrubbers. For affected sources using liquid 

scrubbers, the owner or operator shall establish a minimum 

scrubber liquid flow rate or pressure drop as a site-specific 

operating parameter which must be measured and recorded at least 

once every 15 minutes during the period in which the scrubber is 

controlling HAP from an emission stream as required by the 

standards in §63.1362. If the scrubber uses a caustic solution 

to remove acid emissions, the pH of the effluent scrubber liquid 

shall also be monitored once a day. The minimum scrubber liquid 

flow rate or pressure drop shall be based on the conditions 

under which the initial compliance demonstration was conducted.
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Alternatively, for halogen scrubbers, the owner or operator may

comply with the requirements specified in §63.994(c).

(A) The monitoring device used to determine the pressure 

drop shall be certified by the manufacturer to be accurate to 

within a gage pressure of ±10 percent of the maximum pressure 

drop measured.

(B) The monitoring device used for measurement of scrubber 

liquid flowrate shall be certified by the manufacturer to be 

accurate to within ±10 percent of the design scrubber liquid 

flowrate.

(C) The monitoring device shall be calibrated annually.

(iii) Condensers. For each condenser, the owner or operator 

shall establish the maximum condenser outlet gas temperature as 

a site-specific operating parameter which must be measured and 

recorded at least once every 15 minutes during the period in 

which the condenser is controlling HAP from an emission stream 

as required by the standards in §63.1362.

(A) The temperature monitoring device must be accurate to 

within ±2 percent of the temperature measured in degrees Celsius 

or ±2.5 °C, whichever is greater.

(B) The temperature monitoring device must be calibrated 

annually.

(iv) Regenerative carbon adsorbers. For each regenerative 

carbon adsorber, the owner or operator shall comply with the 
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provisions in paragraphs (b)(1)(iv)(A) through (F) of this 

section.

(A) Establish the regeneration cycle characteristics 

specified in paragraphs (b)(1)(iv)(A) (1) through (4) of this 

section under absolute or hypothetical peak-case conditions, as 

defined in §63.1365(b)(11)(i) or (ii).

(1) Minimum regeneration frequency (i.e., operating time

since last regeneration);

(2) Minimum temperature to which the bed is heated during 

regeneration;

(3) Maximum temperature to which the bed is cooled, 

measured within 15 minutes of completing the cooling phase; and

(4) Minimum regeneration stream flow.

(B) Monitor and record the regeneration cycle 

characteristics specified in paragraphs (b)(1)(iv)(B) (1) 

through (4) of this section for each regeneration cycle.

(1) Regeneration frequency (i.e., operating time since end 

of last regeneration);

(2) Temperature to which the bed is heated during 

regeneration;

(3) Temperature to which the bed is cooled, measured within 

15 minutes of the completion of the cooling phase; and

(4) Regeneration stream flow.
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(C) Use a temperature monitoring device that is accurate to 

within ±2 percent of the temperature measured in degrees Celsius 

or ±2.5 °C, whichever is greater.

(D) Use a regeneration stream flow monitoring device 

capable of recording the total regeneration stream flow to 

within ±10 percent of the established value (i.e., accurate to 

within ±10 percent of the reading).

(E) Calibrate the temperature and flow monitoring devices 

annually.

(F) Conduct an annual check for bed poisoning in accordance 

with manufacturer's specifications.

(v) Nonregenerative carbon adsorbers. For each 

nonregenerative carbon adsorption system such as a carbon 

canister that does not regenerate the carbon bed directly onsite 

in the control device, the owner or operator shall replace the 

existing carbon bed in the control device with fresh carbon on a

regular schedule based on one of the following procedures:

(A) Monitor the TOC concentration level in the exhaust vent 

stream from the carbon adsorption system on a regular schedule, 

and replace the existing carbon with fresh carbon immediately 

when carbon breakthrough is indicated. The monitoring frequency 

shall be daily or at an interval no greater than 20 percent of 

the time required to consume the total carbon working capacity 
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under absolute or hypothetical peak-case conditions as defined 

in §63.1365(b)(11)(i) or (ii), whichever is longer.

(B) Establish the maximum time interval between 

replacement, and replace the existing carbon before this time 

interval elapses. The time interval shall be established based 

on the conditions anticipated under absolute or hypothetical 

peak-case, as defined in §63.1365(b)(11)(i) or (ii).

(vi) Flares. For each flare, the presence of the pilot 

flame shall be monitored at least once every 15 minutes during 

the period in which the flare is controlling HAP from an 

emission stream subject to the standards in §63.1362. The 

monitoring device shall be calibrated annually.

(vii) Thermal incinerators. For each thermal incinerator, 

the owner or operator shall monitor the temperature of the gases 

exiting the combustion chamber as the site-specific operating 

parameter which must be measured and recorded at least once 

every 15 minutes during the period in which the combustion 

device is controlling HAP from an emission stream subject to the 

standards in §63.1362.

(A) The temperature monitoring device must be accurate to 

within ±0.75 percent of the temperature measured in degrees 

Celsius or ±2.5 °C, whichever is greater.

(B) The monitoring device must be calibrated annually.
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(viii) Catalytic incinerators. For each catalytic 

incinerator, the parameter levels that the owner or operator 

shall establish are the minimum temperature of the gas stream 

immediately before the catalyst bed and the minimum temperature 

difference across the catalyst bed. The owner or operator shall 

monitor the temperature of the gas stream immediately before and 

after the catalyst bed, and calculate the temperature difference 

across the catalyst bed, at least once every 15 minutes during 

the period in which the catalytic incinerator is controlling HAP 

from an emission stream subject to the standards in §63.1362.

(A) The temperature monitoring devices must be accurate to 

within ±0.75 percent of the temperature measured in degrees 

Celsius or ±2.5 °C, whichever is greater.

(B) The temperature monitoring devices must be calibrated 

annually.

(ix) Process heaters and boilers. (A) Except as specified 

in paragraph (b)(1)(ix)(B) of this section, for each boiler or 

process heater, the owner or operator shall monitor the 

temperature of the gases exiting the combustion chamber as the 

site-specific operating parameter which must be monitored and 

recorded at least every 15 minutes during the period in which 

the boiler or process heater is controlling HAP from an emission 

stream subject to the standards in §63.1362.
Page 208 of 267

(1) The temperature monitoring device must be accurate to 

within ±0.75 percent of the temperature measured in degrees 

Celsius or ±2.5 °C, whichever is greater.

(2) The temperature monitoring device must be calibrated 

annually.

(B) The owner or operator is exempt from the monitoring 

requirements specified in paragraph (b)(1)(ix)(A) of this 

section if either:

(1) All vent streams are introduced with primary fuel; or

(2) The design heat input capacity of the boiler or process 

heater is 44 megawatts or greater.

(x) Continuous emission monitor. As an alternative to the 

parameters specified in paragraphs (b)(1)(ii) through (ix) of 

this section, an owner or operator may monitor and record the 

outlet HAP concentration or both the outlet TOC concentration 

and outlet total HCl and chlorine concentration at least every 

15 minutes during the period in which the control device is 

controlling HAP from an emission stream subject to the standards 

in §63.1362. The owner or operator need not monitor the total 

HCl and chlorine concentration if the owner or operator 

determines that the emission stream does not contain HCl or 

chlorine. The owner or operator need not monitor the TOC 

concentration if the owner or operator determines the emission 

stream does not contain organic compounds. The HAP or TOC 
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monitor must meet the requirements of Performance Specification 

8 or 9 of appendix B of part 60 and must be installed, 

calibrated, and maintained, according to §63.8 of subpart A of 

this part. As part of the QA/QC Plan, calibration of the device 

must include, at a minimum, quarterly cylinder gas audits. If 

supplemental gases are introduced before the control device, the 

monitored concentration shall be corrected as specified in 

§63.1365(a)(7).

(xi) Fabric filters. For each fabric filter used to control

particulate matter emissions from bag dumps and product dryers 

subject to §63.1362(e), the owner or operator shall install, 

calibrate, maintain, and continuously operate a bag leak 

detection system that meets the requirements in paragraphs 

(b)(1)(xi)(A) through (G) of this section.

(A) The bag leak detection system sensor must provide 

output of relative particulate matter emissions.

(B) The bag leak detection system must be equipped with an 

alarm system that will sound when an increase in particulate 

matter emissions over a preset level is detected.

(C) For positive pressure fabric filters, a bag leak 

detector must be installed in each fabric filter compartment or 

cell. If a negative pressure or induced air filter is used, the 

bag leak detector must be installed downstream of the fabric 

filter. Where multiple bag leak detectors are required (for 
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either type of fabric filter), the system instrumentation and 

alarm may be shared among detectors.

(D) The bag leak detection system shall be installed, 

operated, calibrated and maintained in a manner consistent with 

available guidance from the U.S. Environmental Protection Agency 

or, in the absence of such guidance, the manufacturer's written 

specifications and instructions.

(E) Calibration of the system shall, at a minimum, consist 

of establishing the relative baseline output level by adjusting 

the range and the averaging period of the device and 

establishing the alarm set points and the alarm delay time.

(F) Following initial adjustment, the owner or operator 

shall not adjust the sensitivity or range, averaging period, 

alarm set points, or alarm delay time, except as established in 

an operation and maintenance plan that is to be submitted with 

the Precompliance plan. In no event shall the sensitivity be 

increased more than 100 percent or decreased by more than 50 

percent over a 365-day period unless such adjustment follows a 

complete baghouse inspection which demonstrates the baghouse is 

in good operating condition.

(G) If the alarm on a bag leak detection system is 

triggered, the owner or operator shall, within 1 hour of an 

alarm, initiate the procedures to identify the cause of the 
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alarm and take corrective action as specified in the corrective 

action plan.

(xii) For each waste management unit, treatment process, or 

control device used to comply with §63.1362(d), the owner or 

operator shall comply with the procedures specified in §63.143 

of subpart G of this part, except that when the procedures to 

request approval to monitor alternative parameters according to 

the procedures in §63.151(f) are referred to in §63.143(d)(3), 

the procedures in paragraph (b)(4) of this section shall apply 

for the purposes of this subpart.

(xiii) Closed-vent system visual inspections. The owner or 

operator shall comply with the requirements in either paragraph 

(b)(1)(xiii)(A) or (B) of this section:

(A) Set the flow indicator at the entrance to any bypass 

line that could divert the stream away from the control device 

to the atmosphere to take a reading at least once every 15 

minutes; or

(B) If the bypass device valve installed at the inlet to 

the bypass device is secured in the closed position with a carseal or lock-and-key type configuration, visually inspect the 

seal or closure mechanism at least once every month to verify 

that the valve is maintained in the closed position and the vent 

stream is not diverted through the bypass line.
Page 212 of 267

(2) Averaging periods. Averaging periods for parametric 

monitoring levels shall be established according to paragraphs 

(b)(2)(i) through (iii) of this section.

(i) Except as provided in paragraph (b)(2)(iii) of this 

section, a daily (24-hour) or block average shall be calculated 

as the average of all values for a monitored parameter level set 

according to the procedures in (b)(3)(iii) of this section 

recorded during the operating day or block.

(ii) The operating day or block shall be defined in the 

Notification of Compliance Status report. The operating day may 

be from midnight to midnight or another continuous 24-hour 

period. The operating block may be used as an averaging period 

only for vents from batch operations, and is limited to a period 

of time that is, at a maximum, equal to the time from the 

beginning to end of a series of consecutive batch operations.

(iii) Monitoring values taken during periods in which the 

control devices are not controlling HAP from an emission stream 

subject to the standards in §63.1362, as indicated by periods of 

no flow or periods when only streams that are not subject to the 

standards in §63.1362 are controlled, shall not be considered in 

the averages. Where flow to the device could be intermittent, 

the owner or operator shall install, calibrate and operate a 

flow indicator at the inlet or outlet of the control device to 

identify periods of no flow.
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(3) Procedures for setting parameter levels for control 

devices used to control emissions from process vents. (i) Small 

control devices. Except as provided in paragraph (b)(1)(i) of 

this section, for devices controlling less than 10 tons/yr of 

HAP for which a performance test is not required, the 

parameteric levels shall be set based on the design evaluation 

required in §63.1365(c)(3)(i)(A). If a performance test is 

conducted, the monitoring parameter level shall be established 

according to the procedures in paragraph (b)(3)(ii) of this 

section.

(ii) Large control devices. For devices controlling greater 

than or equal to 10 tons/yr of HAP for which a performance test 

is required, the parameter level must be established as follows:

(A) If the operating parameter level to be established is a

maximum or minimum, it must be based on the average of the 

average values from each of the three test runs.

(B) The owner or operator may establish the parametric 

monitoring level(s) based on the performance test supplemented 

by engineering assessments and/or manufacturer's 

recommendations. Performance testing is not required to be 

conducted over the entire range of expected parameter values. 

The rationale for the specific level for each parameter, 

including any data and calculations used to develop the level(s) 

and a description of why the level indicates proper operation of 
Page 214 of 267

the control device shall be provided in the Precompliance plan. 

Determination of the parametric monitoring level using these 

procedures is subject to review and approval by the 

Administrator.

(iii) Parameter levels for control devices controlling 

batch process vents. For devices controlling batch process vents 

alone or in combination with other streams, the level(s) shall 

be established in accordance with paragraph (b)(3)(iii)(A) or 

(B) of this section.

(A) A single level for the batch process(es) shall be 

calculated from the initial compliance demonstration.

(B) The owner or operator may establish separate levels for 

each batch emission episode or combination of emission episodes 

selected to be controlled. If separate monitoring levels are 

established, the owner or operator must provide a record 

indicating at what point in the daily schedule or log of 

processes required to be recorded per the requirements of 

§63.1367(b)(7), the parameter being monitored changes levels and 

must record at least one reading of the new parameter level, 

even if the duration of monitoring for the new parameter level 

is less than 15 minutes.

(4) Requesting approval to monitor alternative parameters. 

The owner or operator may request approval to monitor parameters 

other than those required by paragraphs (b)(1)(ii) through 
Page 215 of 267

(xiii) of this section. The request shall be submitted according 

to the procedures specified in §63.8(f) of subpart A of this 

part or in the Precompliance report (as specified in 

§63.1368(e)).

(5) Monitoring for the alternative standards. (i) For 

control devices that are used to comply with the provisions of 

§63.1362(b)(6) and (c)(4), the owner or operator shall monitor 

and record the outlet TOC concentration and the outlet total HCl 

and chlorine concentration at least once every 15 minutes during 

the period in which the device is controlling HAP from emission 

streams subject to the standards in §63.1362. A TOC monitor 

meeting the requirements of Performance Specification 8 or 9 of 

appendix B of 40 CFR part 60 shall be installed, calibrated, and 

maintained, according to §63.8. The owner or operator need not 

monitor the total HCl and chlorine concentration if the owner or 

operator determines that the emission stream does not contain 

HCl or chlorine. The owner or operator need not monitor for TOC 

concentration if the owner or operator determines that the 

emission stream does not contain organic compounds.

(ii) If supplemental gases are introduced before the 

control device, the owner or operator must either correct for 

supplemental gases as specified in §63.1365(a)(7) or, if using a 

combustion control device, comply with the requirements of 

paragraph (b)(5)(ii)(A) of this section. If the owner or 
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operator corrects for supplemental gases as specified in 

§63.1365(a)(7)(ii) for non-combustion control devices, the flow 

rates must be evaluated as specified in paragraph (b)(5)(ii)(B) 

of this section.

(A) Provisions for combustion devices. As an alternative to 

correcting for supplemental gases as specified in 

§63.1365(a)(7), the owner or operator may monitor residence time 

and firebox temperature according to the requirements of 

paragraphs (b)(5)(ii)(A)(1) and (2) of this section. Monitoring 

of residence time may be accomplished by monitoring flow rate 

into the combustion chamber.

(1) If complying with the alternative standard instead of 

achieving a control efficiency of 95 percent or less, the owner 

or operator must maintain a minimum residence time of 0.5 

seconds and a minimum combustion chamber temperature of 760 °C.

(2) If complying with the alternative standard instead of 

achieving a control efficiency of 98 percent, the owner or 

operator must maintain a minimum residence time of 0.75 seconds 

and a minimum combustion chamber temperature of 816 °C.

(B) Flow rate evaluation for non-combustion devices. To 

demonstrate continuous compliance with the requirement to 

correct for supplemental gases as specified in 

§63.1365(a)(7)(ii) for non-combustion devices, the owner or 

operator must evaluate the volumetric flow rate of supplemental 
Page 217 of 267

gases, Vs, and the volumetric flow rate of all gases, Va, each 

time a new operating scenario is implemented based on process 

knowledge and representative operating data. The procedures used 

to evaluate the flow rates, and the resulting correction factor 

used in Equation 8 of this subpart, must be included in the 

Notification of Compliance Status report and in the next 

Periodic report submitted after an operating scenario change.

(6) Exceedances of operating parameters. An exceedance of 

an operating parameter is defined as one of the following:

(i) If the parameter level, averaged over the operating day 

or block, is below a minimum value established during the 

initial compliance demonstration.

(ii) If the parameter level, averaged over the operating 

day or block, is above the maximum value established during the 

initial compliance demonstration.

(iii) A loss of all pilot flames for a flare during an 

operating day or block. Multiple losses of all pilot flames 

during an operating day constitutes one exceedance.

(iv) Each operating day or block for which the time 

interval between replacement of a nonregenerative carbon 

adsorber exceeds the interval established in paragraph (b)(1)(v) 

of this section.
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(v) Each instance in which procedures to initiate the 

response to a bag leak detector alarm within 1 hour of the alarm 

as specified in the corrective action plan.

(7) Excursions. Excursions are defined by either of the two 

cases listed in paragraph (b)(7)(i) or (ii) of this section. An 

excursion also occurs if the periodic verification for a small 

control device is not conducted as specified in paragraph 

(b)(1)(i) of this section.

(i) When the period of control device operation is 4 hours 

or greater in an operating day or block and monitoring data are 

insufficient to constitute a valid hour of data, as defined in 

paragraph (b)(7)(iii) of this section, for at least 75 percent 

of the operating hours.

(ii) When the period of control device operation is less

than 4 hours in an operating day or block and more than 1 of the 

hours during the period of operation does not constitute a valid 

hour of data due to insufficient monitoring data.

(iii) Monitoring data are insufficient to constitute a 

valid hour of data, as used in paragraphs (b)(7)(i) and (ii) of 

this section, if measured values are unavailable for any of the 

required 15-minute periods within the hour.

(8) Violations. Exceedances of parameters monitored 

according to the provisions of paragraphs (b)(1)(ii), (b)(1)(iv) 

through (ix), and (b)(5)(i)(A) of this section, or excursions as 
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defined by paragraphs (b)(7)(i) and (ii) of this section, 

constitute violations of the operating limit according to 

paragraphs (b)(8)(i), and (ii), and (iv) of this section. 

Exceedances of the temperature limit monitored according to the 

provisions of paragraph (b)(1)(iii) of this section or 

exceedances of the outlet concentrations monitored according to 

the provisions of paragraph (b)(1)(x) of this section constitute 

violations of the emission limit according to paragraphs (b)(8)

(i), and (ii), and (iv) of this section. Exceedances of the 

outlet concentrations monitored according to the provisions of 

paragraph (b)(5) of this section constitute violations of the 

emission limit according to the provisions of paragraphs (b)(8)

(iii) and (iv) of this section.

(i) Except as provided in paragraph (b)(8)(iv) of this 

section, fFor episodes occurring more than once per day, 

exceedances of established parameter limits or excursions will 

result in no more than one violation per operating day for each 

monitored item of equipment utilized in the process.

(ii) Except as provided in paragraph (b)(8)(iv) of this 

section, fFor control devices used for more than one process in 

the course of an operating day, exceedances or excursions will 

result in no more than one violation per operating day, per 

control device, for each process for which the control device is 

in service.
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(iii) Except as provided in paragraph (b)(8)(iv) of this 

section, eExceedances of the 20 or 50 ppmv TOC outlet emission 

limit, averaged over the operating day, will result in no more 

than one violation per day per control device. Except as 

provided in paragraph (b)(8)(iv) of this section, eExceedances 

of the 20 or 50 ppmv HCl and chlorine outlet emission limit, 

averaged over the operating day, will result in no more than one 

violation per day per control device.

(iv) Periods of time when monitoring measurements exceed 

the parameter values as well as periods of inadequate monitoring 

data do not constitute a violation if they occur during a 

startup, shutdown, or malfunction, and the facility operates in 

accordance with §63.6(e)(1).

(c) Monitoring for uncontrolled emission rates. The owner 

or operator shall demonstrate continuous compliance with the 

emission limit in §63.1362(b)(2)(i) or (b)(4)(i) by calculating 

daily a 365-day rolling summation of uncontrolled emissions 

based on the uncontrolled emissions per emission episode, as 

calculated using the procedures in §63.1365(c)(2), and records 

of the number of batches produced. Each day that the summation 

for a process exceeds 0.15 Mg/yr is considered a violation of 

the emission limit.
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(d) Monitoring for equipment leaks. The standard for 

equipment leaks is based on monitoring. All monitoring 

requirements for equipment leaks are specified in §63.1363.

(e) Monitoring for heat exchanger systems. The standard for 

heat exchanger systems is based on monitoring. All monitoring 

requirements for heat exchanger systems are specified in 

§63.1362(f).

(f) Monitoring for the pollution prevention alternative 

standard. The owner or operator of an affected source that 

chooses to comply with the requirements of §63.1362(g) (2) or 

(3) shall calculate annual rolling average values of the HAP and 

VOC factors in accordance with the procedures specified in 

paragraph (f)(1) of this section. If complying with 

§63.1362(g)(3), the owner or operator shall also comply with the 

monitoring requirements specified in paragraph (b) of this 

section for the applicable add-on air pollution control device.

(1) Annual factors. The annual HAP and VOC factors shall be 

calculated in accordance with the procedures specified in 

paragraphs (f)(1) (i) through (iii) of this section.

(i) The consumption of both total HAP and total VOC shall 

be divided by the production rate, per process, for 12-month 

periods at the frequency specified in either paragraph (f)(1) 

(ii) or (iii) of this section, as applicable.
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(ii) For continuous processes, the annual factors shall be 

calculated every 30 days for the 12-month period preceding the 

30th day (annual rolling average calculated every 30 days). A 

process with both batch and continuous operations is considered 

a continuous process for the purposes of this section.

(iii) For batch processes, the annual factors shall be 

calculated every 10 batches for the 12-month period preceding 

the 10th batch (annual rolling average calculated every 10 

batches). Additional annual factors shall be calculated every 12 

months during the period before the 10th batch if more than 12 

months elapse before the 10th batch is produced.

(2) Violations. Each rolling average that exceeds the 

target value established in §63.1365(g)(3) is considered a 

violation of the emission limit.

(g) Monitoring for emissions averaging. The owner or 

operator of an affected source that chooses to comply with the 

requirements of §63.1362(h) shall meet all monitoring 

requirements specified in paragraph (b) of this section, as 

applicable, for all processes, storage tanks, and waste 

management units included in the emissions average.

(h) Leak inspection provisions for vapor suppression 

equipment. (1) Except as provided in paragraphs (h)(9) and (10) 

of this section, for each vapor collection system, closed-vent 

system, fixed roof, cover, or enclosure required to comply with 
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this section, the owner or operator shall comply with the 

requirements of paragraphs (h)(2) through (8) of this section.

(2) Except as provided in paragraphs (h)(6) and (7) of this 

section, each vapor collection system and closed-vent system 

shall be inspected according to the procedures and schedule 

specified in paragraphs (h)(2)(i) and (ii) of this section and 

each fixed roof, cover, and enclosure shall be inspected 

according to the procedures and schedule specified in paragraph 

(h)(2)(iii) of this section.

(i) If the vapor collection system or closed-vent system is 

constructed of hard-piping, the owner or operator shall:

(A) Conduct an initial inspection according to the 

procedures in paragraph (h)(3) of this section, and

(B) Conduct annual visual inspections for visible, audible, 

or olfactory indications of leaks.

(ii) If the vapor collection system or closed-vent system 

is constructed of ductwork, the owner or operator shall:

(A) Conduct an initial inspection according to the 

procedures in paragraph (h)(3) of this section,

(B) Conduct annual inspections according to the procedures 

in paragraph (h)(3) of this section, and

(C) Conduct annual visual inspections for visible, audible, 

or olfactory indications of leaks.
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(iii) For each fixed roof, cover, and enclosure, the owner 

or operator shall:

(A) Conduct an initial inspection according to the 

procedures in paragraph (h)(3) of this section, and

(B) Conduct semiannual visual inspections for visible, 

audible, or olfactory indications of leaks.

(3) Each vapor collection system, closed-vent system, fixed 

roof, cover, and enclosure shall be inspected according to the 

procedures specified in paragraphs (h)(3)(i) through (vi) of 

this section.

(i) Inspections shall be conducted in accordance with 

Method 21 of 40 CFR part 60, appendix A.

(ii) Detection instrument performance criteria. (A) Except 

as provided in paragraph (h)(3)(ii)(B) of this section, the 

detection instrument shall meet the performance criteria of 

Method 21 of 40 CFR part 60, appendix A, except the instrument 

response factor criteria in section 3.1.2(a) of Method 21 shall 

be for the average composition of the process fluid not each 

individual VOC in the stream. For process streams that contain 

nitrogen, air, or other inerts which are not organic HAP or VOC, 

the average stream response factor shall be calculated on an 

inert-free basis.

(B) If no instrument is available at the plant site that 

will meet the performance criteria specified in paragraph 
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(h)(3)(ii)(A) of this section, the instrument readings may be 

adjusted by multiplying by the average response factor of the 

process fluid, calculated on an inert-free basis as described in 

paragraph (h)(3)(ii)(A) of this section.

(iii) The detection instrument shall be calibrated before 

use on each day of its use by the procedures specified in Method 

21 of 40 CFR part 60, appendix A.

(iv) Calibration gases shall be as follows:

(A) Zero air (less than 10 parts per million hydrocarbon in 

air); and

(B) Mixtures of methane in air at a concentration less than 

10,000 parts per million. A calibration gas other than methane 

in air may be used if the instrument does not respond to methane 

or if the instrument does not meet the performance criteria 

specified in paragraph (h)(2)(ii)(A) of this section. In such 

cases, the calibration gas may be a mixture of one or more of 

the compounds to be measured in air.

(v) An owner or operator may elect to adjust or not adjust 

instrument readings for background. If an owner or operator 

elects to not adjust readings for background, all such 

instrument readings shall be compared directly to the applicable 

leak definition to determine whether there is a leak. If an 

owner or operator elects to adjust instrument readings for 

background, the owner or operator shall measure background 
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concentration using the procedures in §63.180(b) and (c). The 

owner or operator shall subtract background reading from the 

maximum concentration indicated by the instrument.

(vi) The arithmetic difference between the maximum 

concentration indicated by the instrument and the background 

level shall be compared with 500 parts per million for 

determining compliance.

(4) Leaks, as indicated by an instrument reading greater 

than 500 parts per million above background or by visual 

inspections, shall be repaired as soon as practicable, except as 

provided in paragraph (h)(5) of this section.

(i) A first attempt at repair shall be made no later than 5 

calendar days after the leak is detected.

(ii) Repair shall be completed no later than 15 calendar 

days after the leak is detected.

(5) Delay of repair of a vapor collection system, closedvent system, fixed roof, cover, or enclosure for which leaks 

have been detected is allowed if the repair is technically 

infeasible without a shutdown, as defined in §63.1361, or if the 

owner or operator determines that emissions resulting from 

immediate repair would be greater than the fugitive emissions 

likely to result from delay of repair. Repair of such equipment 

shall be complete by the end of the next shutdown.
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(6) Any parts of the vapor collection system, closed-vent 

system, fixed roof, cover, or enclosure that are designated, as 

described in §63.1367(f)(1), as unsafe-to-inspect are exempt 

from the inspection requirements of paragraphs (h)(2)(i), (ii), 

and (iii) of this section if:

(i) The owner or operator determines that the equipment is 

unsafe-to-inspect because inspecting personnel would be exposed 

to an imminent or potential danger as a consequence of complying 

with paragraph (h)(2)(i), (ii), or (iii) of this section; and

(ii) The owner or operator has a written plan that requires 

inspection of the equipment as frequently as practicable during 

safe-to-inspect times. Inspection is not required more than once 

annually.

(7) Any parts of the vapor collection system, closed-vent 

system, fixed roof, cover, or enclosure that are designated, as 

described in §63.1367(f)(2), as difficult-to-inspect are exempt 

from the inspection requirements of paragraphs (h)(2)(i), (ii), 

and (iii)(A) of this section if:

(i) The owner or operator determines that the equipment 

cannot be inspected without elevating the inspecting personnel 

more than 2 meters above a support surface; and

(ii) The owner or operator has a written plan that requires

inspection of the equipment at least once every 5 years.
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(8) Records shall be maintained as specified in 

§63.1367(f).

(9) If a closed-vent system subject to this section is also 

subject to the equipment leak provisions of §63.1363, the owner 

or operator shall comply with the provisions of §63.1363 and is 

exempt from the requirements of this section.

(10) For any closed-vent system that is operated and 

maintained under negative pressure, the owner or operator is not 

required to comply with the requirements specified in paragraphs 

(h)(2) through (8) of this section.

§63.1367 Recordkeeping requirements.

(a) Requirements of subpart A of this part. The owner or 

operator of an affected source shall comply with the 

recordkeeping requirements in subpart A of this part as 

specified in Table 1 of this subpart and in paragraphs (a)(1) 

through (5) of this section.

(1) Data retention. Each owner or operator of an affected 

source shall keep copies of all records and reports required by 

this subpart for at least 5 years, as specified in §63.10(b)(1) 

of subpart A of this part.

(2) Records of applicability determinations. The owner or 

operator of a stationary source that is not subject to this 

subpart shall keep a record of the applicability determination, 

as specified in §63.10(b)(3) of subpart A of this part.
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(3) Startup, shutdown, andRecords of malfunctions plan. The 

owner or operator of an affected source shall develop a written 

startup, shutdown, and malfunction plan as specified in 

§63.6(e)(3). This plan shall describe, in detail, procedures for 

operating and maintaining the affected source during periods of 

startup, shutdown, and malfunction and a program for corrective 

action for a malfunctioning process, air pollution control, and 

monitoring equipment used to comply with this subpart. The owner 

or operator of an affected source shall keep the current and 

superseded versions of this plan onsite, as specified in 

§63.6(e)(3)(v) of subpart A of this part. The owner or operator 

shall keep the startup, shutdown, and malfunction records 

specified in paragraphs (a)(3)(i) through (iii) of this section. 

Reports related to the plan shall be submitted as specified in 

§63.1368(i).

(i) In the event that an affected unit fails to meet an 

applicable standard, record the number of failures. For each 

failure record the date, time, and duration of each failure.The 

owner or operator shall record the occurrence and duration of 

each malfunction of the process operations or of air pollution 

control equipment used to comply with this subpart, as specified 

in §63.6(e)(3)(iii).

(ii) For each failure to meet an applicable standard, 

record and retain a list of the affected sources or equipment, 
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an estimate of the quantity of each regulated pollutant emitted 

over any emission limit, and a description of the method used to 

estimate the emissions.The owner or operator shall record the 

occurrence and duration of each malfunction of continuous 

monitoring systems used to comply with this subpart.

(iii) For each startup, shutdown, or malfunction, the owner 

or operator shall record all information necessary to 

demonstrate that the procedures specified in the affected 

source's startup, shutdown, and malfunction plan were followed, 

as specified in §63.6(e)(3)(iii) of subpart A of this part; 

alternatively, the owner or operator shall record any actions 

taken that are not consistent with the plan, as specified in 

§63.6(e)(3)(iv) of subpart A of this part.

(iii) Record actions taken to minimize emissions in 

accordance with §63.1360(e)(4), and any corrective actions taken 

to return the affected unit to its normal or usual manner of 

operation.

(4) Recordkeeping requirements for sources with continuous 

monitoring systems. The owner or operator of an affected source 

who installs a continuous monitoring system to comply with the 

alternative standards in §63.1362(b)(6) or (c)(4) shall maintain 

records specified in §63.10(c)(1) through (14) of subpart A of 

this part.
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(5) Application for approval of construction or 

reconstruction. For new affected sources, each owner or operator 

shall comply with the provisions regarding construction and 

reconstruction in §63.5 of subpart A of this part.

(b) Records of equipment operation. The owner or operator 

must keep the records specified in paragraphs (b)(1) through 

(11) of this section up-to-date and readily accessible.

(1) Each measurement of a control device operating 

parameter monitored in accordance with §63.1366 and each 

measurement of a treatment process parameter monitored in 

accordance with the provisions of §63.1362(d).

(2) For processes subject to §63.1362(g), records of 

consumption, production, and the rolling average values of the 

HAP and VOC factors.

(3) For each continuous monitoring system used to comply 

with the alternative standards in §63.1362(b)(6) and (c)(4), 

records documenting the completion of calibration checks and 

maintenance of the continuous monitoring systems.

(4) For processes in compliance with the 0.15 Mg/yr 

emission limit of §63.1362(b)(2)(i) or (b)(4)(i), daily records 

of the rolling annual calculations of uncontrolled emissions.

(5) For each bag leak detector used to monitor particulate 

HAP emissions from a fabric filter, the owner or operator shall 

maintain records of any bag leak detection alarm, including the 
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date and time, with a brief explanation of the cause of the 

alarm and the corrective action taken.

(6) The owner or operator of an affected source that 

complies with the standards for process vents, storage tanks, 

and wastewater systems shall maintain up-to-date, readily 

accessible records of the information specified in paragraphs 

(b)(6)(i) through (vii) of this section to document that HAP 

emissions or HAP loadings (for wastewater) are below the limits 

specified in §63.1362:

(i) Except as specified in paragraph (b)(6)(ix) of this 

section, the initial calculations of uncontrolled and controlled 

emissions of gaseous organic HAP and HCl per batch for each 

process.

(ii) The wastewater concentrations and flow rates per POD 

and process.

(iii) The number of batches per year for each batch 

process.

(iv) The operating hours per year for continuous processes.

(v) The number of batches and the number of operating hours 

for processes that contain both batch and continuous operations.

(vi) The number of tank turnovers per year, if used in an 

emissions average or for determining applicability of a new PAI 

process unit.
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(vii) A description of absolute or hypothetical peak-case 

operating conditions as determined using the procedures in 

§63.1365(b)(11).

(viii) Periods of planned routine maintenance as described 

in §63.1362(c)(5).

(ix) As an alternative to the records in paragraph 

(b)(6)(i) of this section, a record of the determination that 

the conditions in §63.1365(b)(11)(iii)(D)(1) or (2) are met.

(7) Daily schedule or log of each operating scenario 

updated daily or, at a minimum, each time a different operating 

scenario is put into operation.

(8) If the owner or operator elects to comply with the 

vapor balancing alternative in §63.1362(c)(6), the owner or 

operator must keep records of the DOT certification required by 

§63.1362(c)(6)(ii) and the pressure relief vent setting and leak 

detection records specified in §63.1362(c)(6)(v).

(9) If the owner or operator elects to develop process unit 

groups, the owner or operator must keep records of the PAI and 

non-PAI process units in the process unit group, including 

records of the operating time for process units used to 

establish the process unit group. The owner or operator must 

also keep records of any redetermination of the primary product 

for the process unit group.
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(10) All maintenance performed on the air pollution control 

equipment.

(11) If the owner or operator elects to comply with 

§63.1362(c) by installing a floating roof, the owner or operator 

must keep records of each inspection and seal gap measurement in 

accordance with §63.123(c) through (e) as applicable.

(c) Records of equipment leak detection and repair. The 

owner or operator of an affected source subject to the equipment 

leak standards in §63.1363 shall implement the recordkeeping 

requirements specified in §63.1363(g). All records shall be 

retained for a period of 5 years, in accordance with the 

requirements of §63.10(b)(1) of subpart A of this part.

(d) Records of emissions averaging. The owner or operator 

of an affected source that chooses to comply with the 

requirements of §63.1362(h) shall maintain up-to-date records of 

the following information:

(1) An Emissions Averaging Plan which shall include in the 

plan, for all emission points included in each of the emissions 

averages, the information listed in paragraphs (d)(1)(i) through 

(v) of this section.

(i) The identification of all emission points in each 

emissions average.

(ii) The values of all parameters needed for input to the 

emission debits and credits equations in §63.1365(h).
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(iii) The calculations used to obtain the debits and 

credits.

(iv) The estimated values for all parameters required to be 

monitored under §63.1366(g) for each emission point included in 

an average. These parameter values, or as appropriate, limited 

ranges for parameter values, shall be specified as enforceable 

operating conditions for the operation of the process, storage 

vessel, or waste management unit, as appropriate. Changes to the 

parameters must be reported as required by §63.1368(k).

(v) A statement that the compliance demonstration, 

monitoring, inspection, recordkeeping and reporting provisions 

in §63.1365(h), §63.1366(g), and §63.1368(k) that are applicable 

to each emission point in the emissions average will be 

implemented beginning on the date of compliance.

(2) The Emissions Averaging Plan shall demonstrate that the 

emissions from the emission points proposed to be included in 

the average will not result in greater hazard or, at the option 

of the operating permit authority, greater risk to human health 

or the environment than if the emission points were controlled 

according to the provisions in §63.1362(b) through (d).

(i) This demonstration of hazard or risk equivalency shall 

be made to the satisfaction of the operating permit authority.
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(A) The Administrator may require an owner or operator to 

use specific methodologies and procedures for making a hazard or 

risk determination.

(B) The demonstration and approval of hazard or risk 

equivalency shall be made according to any guidance that the 

Administrator makes available for use or any other technically 

sound information or methods.

(ii) An Emissions Averaging Plan that does not demonstrate 

hazard or risk equivalency to the satisfaction of the 

Administrator shall not be approved. The Administrator may 

require such adjustments to the Emissions Averaging Plan as are 

necessary in order to ensure that the average will not result in 

greater hazard or risk to human health or the environment than 

would result if the emission points were controlled according to 

§63.1362(b) through (d).

(iii) A hazard or risk equivalency demonstration must 

satisfy the requirements specified in paragraphs (d)(2)(iii) (A) 

through (C) of this section.

(A) Be a quantitative, comparative chemical hazard or risk 

assessment;

(B) Account for differences between averaging and 

nonaveraging options in chemical hazard or risk to human health 

or the environment; and
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(C) Meet any requirements set by the Administrator for such 

demonstrations.

(3) Records as specified in paragraphs (a) and (b) of this 

section.

(4) A calculation of the debits and credits as specified in 

§63.1365(h) for the last quarter and the prior four quarters.

(e) The owner or operator of an affected source subject to 

the requirements for heat exchanger systems in §63.1362(g) shall 

retain the records as specified in §63.104(f)(1)(i) through (iv) 

of subpart GF of this part.

(f) Records of inspections. The owner or operator shall 

keep records specified in paragraphs (f)(1) through (6) of this 

section.

(1) Records identifying all parts of the vapor collection 

system, closed-vent system, fixed roof, cover, or enclosure that 

are designated as unsafe to inspect in accordance with 

§63.1366(h)(6), an explanation of why the equipment is unsafeto-inspect, and the plan for inspecting the equipment.

(2) Records identifying all parts of the vapor collection 

system, closed-vent system, fixed roof, cover, or enclosure that 

are designated as difficult-to-inspect in accordance with 

§63.1366(h)(7), an explanation of why the equipment is 

difficult-to-inspect, and the plan for inspecting the equipment.
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(3) For each vapor collection system or closed-vent system 

that contains bypass lines that could divert a vent stream away 

from the control device and to the atmosphere, the owner or 

operator shall keep a record of the information specified in 

either paragraph (f)(3)(i) or (ii) of this section.

(i) Hourly records of whether the flow indicator specified 

under §63.1362(j)(1) was operating and whether a diversion was 

detected at any time during the hour, as well as records of the 

times and durations of all periods when the vent stream is 

diverted from the control device or the flow indicator is not 

operating.

(ii) Where a seal mechanism is used to comply with 

§63.1362(j)(2), hourly records of flow are not required. In such 

cases, the owner or operator shall record that the monthly 

visual inspection of the seals or closure mechanisms has been 

done and shall record the occurrence of all periods when the 

seal mechanism is broken, the bypass line valve position has 

changed, or the key for a lock-and-key type lock has been 

checked out, and records of any car-seal that has broken.

(4) For each inspection conducted in accordance with 

§63.1366(h)(2) and (3) during which a leak is detected, a record 

of the information specified in paragraphs (f)(4)(i) through 

(ix) of this section.

(i) Identification of the leaking equipment.
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(ii) The instrument identification numbers and operator 

name or initials, if the leak was detected using the procedures 

described in §63.1366(h)(3); or a record of that the leak was 

detected by sensory observations.

(iii) The date the leak was detected and the date of the 

first attempt to repair the leak.

(iv) Maximum instrument reading measured by the method 

specified in §63.1366(h)(4) after the leak is successfully 

repaired or determined to be nonrepairable.

(v) “Repair delayed” and the reason for the delay if a leak 

is not repaired within 15 calendar days after discovery of the 

leak.

(vi) The name, initials, or other form of identification of 

the owner or operator (or designee) whose decision it was that 

repair could not be effected without a shutdown.

(vii) The expected date of successful repair of the leak if 

a leak is not repaired within 15 calendar days.

(viii) Dates of shutdowns that occur while the equipment is 

unrepaired.

(ix) The date of successful repair of the leak.

(5) For each inspection conducted in accordance with 

§63.1366(h)(3) during which no leaks are detected, a record that 

the inspection was performed, the date of the inspection, and a 

statement that no leaks were detected.
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(6) For each visual inspection conducted in accordance with 

§63.1366(h)(2)(i)(B) or (iii)(B) of this section during which no 

leaks are detected, a record that the inspection was performed, 

the date of the inspection, and a statement that no leaks were 

detected.

(g) Records of primary use. For a PAI process unit that is 

used to produce a given material for use as a PAI as well as for 

other purposes, the owner or operator shall keep records of the 

total production and the production for use as a PAI on a 

semiannual or more frequent basis if the use as a PAI is not the 

primary use.

§63.1368 Reporting requirements.

(a) The owner or operator of an affected source shall 

comply with the reporting requirements of paragraphs (b) through 

(l) of this section. The owner or operator shall also comply 

with applicable paragraphs of §§63.9 and 63.10 of subpart A of 

this part, as specified in Table 1 of this subpart.

(b) Initial notification. The owner or operator shall 

submit the applicable initial notification in accordance with 

§63.9(b) or (d) of subpart A of this part.

(c) Application for approval of construction or 

reconstruction. The owner or operator who is subject to 

§63.5(b)(3) of subpart A of this part shall submit to the 

Administrator an application for approval of the construction of 
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a new major source, the reconstruction of a major affected 

source, or the reconstruction of a major affected source subject 

to the standards. The application shall be prepared in 

accordance with §63.5(d) of subpart A of this part.

(d) Notification of continuous monitoring system 

performance evaluation. An owner or operator who is required by 

the Administrator to conduct a performance evaluation for a 

continuous monitoring system that is used to comply with the 

alternative standard in §63.1362(b)(6) or (c)(4) shall notify 

the Administrator of the date of the performance evaluation as 

specified in §63.8(e)(2) of subpart A of this part.

(e) Precompliance plan. The Precompliance plan shall be 

submitted at least 3 months prior to the compliance date of the 

standard. For new sources, the Precompliance plan shall be 

submitted to the Administrator with the application for approval 

of construction or reconstruction. The Administrator shall have 

90 days to approve or disapprove the Precompliance plan. The 

Precompliance plan shall be considered approved if the 

Administrator either approves it in writing, or fails to 

disapprove it in writing within the 90-day time period. The 90-

day period shall begin when the Administrator receives the 

Precompliance plan. If the Precompliance plan is disapproved, 

the owner or operator must still be in compliance with the 

standard by the compliance date. To change any of the 
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information submitted in the Precompliance plan or to submit a 

Precompliance plan for the first time after the compliance date, 

the owner or operator shall notify the Administrator at least 90 

days before the planned change is to be implemented; the change 

shall be considered approved if the Administrator either 

approves the change in writing, or fails to disapprove the 

change in writing within 90 days of receipt of the change. The 

Precompliance plan shall include the information specified in 

paragraphs (e)(1) through (5) of this section.

(1) Requests for approval to use alternative monitoring 

parameters or requests to set monitoring parameters according to 

§63.1366(b)(4).

(2) Descriptions of the daily or per batch demonstrations 

to verify that control devices subject to §63.1366(b)(1)(i) are 

operating as designed.

(3) Data and rationale used to support the parametric 

monitoring level(s) that are set according to 

§63.1366(b)(3)(ii)(B).

(4) For owners and operators complying with the 

requirements of §63.1362(g), the pollution prevention 

demonstration summary required in §63.1365(g)(1).

(5) Data and rationale used to support an engineering 

assessment to calculate uncontrolled emissions from process 

vents as required in §63.1365(c)(2)(ii).
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(6) For fabric filters that are monitored with bag leak 

detectors, an operation and maintenance plan that describes 

proper operation and maintenance procedures, and a corrective 

action plan that describes corrective actions to be taken, and 

the timing of those actions, when the particulate matter 

concentration exceeds the setpoint and activates the alarm.

(f) Notification of compliance status report. The 

Notification of Compliance Status report required under §63.9(h) 

shall be submitted no later than 150 calendar days after the 

compliance date and shall include the information specified in 

paragraphs (f)(1) through (7) of this section.

(1) The results of any applicability determinations, 

emission calculations, or analyses used to identify and quantify 

HAP emissions from the affected source.

(2) The results of emissions profiles, performance tests, 

engineering analyses, design evaluations, or calculations used 

to demonstrate compliance. For performance tests, results should 

include descriptions of sampling and analysis procedures and 

quality assurance procedures.

(3) Descriptions of monitoring devices, monitoring 

frequencies, and the values of monitored parameters established 

during the initial compliance determinations, including data and 

calculations to support the levels established.

(4) Operating scenarios.
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(5) Descriptions of absolute or hypothetical peak-case 

operating and/or testing conditions for control devices.

(6) Identification of emission points subject to 

overlapping requirements described in §63.1360(i) and the 

authority under which the owner or operator will comply, and 

identification of emission sources discharging to devices 

described by §63.1362(l).

(7) Anticipated periods of planned routine maintenance 

during which the owner or operator would not be in compliance 

with the provisions in §63.1362(c)(1) through (4).

(8) Percentage of total production from a PAI process unit 

that is anticipated to be produced for use as a PAI in the 3 

years after either June 23, 1999 or startup, whichever is later.

(9) Records of the initial process units used to create 

each process unit group, if applicable.

(g) Periodic reports. The owner or operator shall prepare 

Periodic reports in accordance with paragraphs (g)(1) and (2) of 

this section and submit them to the Administrator.

(1) Submittal schedule. Except as provided in paragraphs 

(g)(1)(i) and (ii) of this section, the owner or operator shall 

submit Periodic reports semiannually. The first report shall be 

submitted no later than 240 days after the date the Notification 

of Compliance Status report is due and shall cover the 6-month 

period beginning on the date the Notification of Compliance 
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Status report is due. Each subsequent Periodic report shall 

cover the 6-month period following the preceding period and 

shall be submitted no later than 60 days after the end of the 

applicable period.

(i) The Administrator may determine on a case-by-case basis 

that more frequent reporting is necessary to accurately assess 

the compliance status of the affected source.

(ii) Quarterly reports shall be submitted when the 

monitoring data are used to comply with the alternative 

standards in §63.1362(b)(6) or (c)(4) and the source experiences 

excess emissions. Once an affected source reports excess 

emissions, the affected source shall follow a quarterly 

reporting format until a request to reduce reporting frequency 

is approved. If an owner or operator submits a request to reduce 

the frequency of reporting, the provisions in §63.10(e)(3) (ii) 

and (iii) of subpart A of this part shall apply, except that the 

term “excess emissions and continuous monitoring system 

performance report and/or summary report” shall mean “Periodic 

report” for the purposes of this section.

(2) Content of periodic report. The owner or operator shall 

include the information in paragraphs (g)(2)(i) through (xii) of 

this section, as applicable.
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(i) Each Periodic report must include the information in 

§63.10(e)(3)(vi)(A) through (M) of subpart A of this part, as 

applicable.

(ii) If the total duration of excess emissions, parameter 

exceedances, or excursions for the reporting period is 1 percent 

or greater of the total operating time for the reporting period, 

or the total continuous monitoring system downtime for the 

reporting period is 5 percent or greater of the total operating 

time for the reporting period, the Periodic report must include 

the information in paragraphs (g)(2)(ii)(A) through (D) of this 

section.

(A) Monitoring data, including 15-minute monitoring values 

as well as daily average values of monitored parameters, for all 

operating days when the average values were outside the ranges 

established in the Notification of Compliance Status report or 

operating permit.

(B) Duration of excursions, as defined in §63.1366(b)(7).

(C) Operating logs and operating scenarios for all 

operating days when the values are outside the levels 

established in the Notification of Compliance Status report or 

operating permit.

(D) When a continuous monitoring system is used, the 

information required in §63.10(c)(5) through (13) of subpart A 

of this part.
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(iii) For each vapor collection system or closed vent 

system with a bypass line subject to §63.1362(j)(1), records 

required under §63.1366(f) of all periods when the vent stream 

is diverted from the control device through a bypass line. For 

each vapor collection system or closed vent system with a bypass 

line subject to §63.1362(j)(2), records required under 

§63.1366(f) of all periods in which the seal mechanism is 

broken, the bypass valve position has changed, or the key to 

unlock the bypass line valve was checked out.

(iv) The information in paragraphs (g)(2)(iv)(A) through 

(D) of this section shall be stated in the Periodic report, when 

applicable.

(A) No excess emissions.

(B) No exceedances of a parameter.

(C) No excursions.

(D) No continuous monitoring system has been inoperative, 

out of control, repaired, or adjusted.

(v) For each storage vessel subject to control 

requirements:

(A) Actual periods of planned routine maintenance during 

the reporting period in which the control device does not meet 

the specifications of §63.1362(c)(5); and

(B) Anticipated periods of planned routine maintenance for 

the next reporting period.
Page 248 of 267

(vi) For each PAI process unit that does not meet the 

definition of primary use, the percentage of the production in 

the reporting period produced for use as a PAI.

(viii) Updates to the corrective action plan.

(ix) Records of process units added to each process unit 

group, if applicable.

(x) Records of redetermination of the primary product for a 

process unit group.

(xi) For each inspection conducted in accordance with 

§63.1366(h)(2) or (3) during which a leak is detected, the 

records specify in §63.1367(h)(4) must be included in the next 

Periodic report.

(xii) If the owner or operator elects to comply with the 

provisions of §63.1362(c) by installing a floating roof, the 

owner or operator shall submit the information specified in 

§63.122(d) through (f) as applicable. References to §63.152 in 

§63.122 shall not apply for the purposes of this subpart.

(h) Notification of process change. (1) Except as specified 

in paragraph (h)(2) of this section, whenever a process change 

is made, or any of the information submitted in the Notification 

of Compliance Status report changes, the owner or operator shall 

submit the information specified in paragraphs (h)(1)(i) through 

(iv) of this section with the next Periodic report required 

under paragraph (g) of this section. For the purposes of this 
Page 249 of 267

section, a process change means the startup of a new process, as 

defined in §63.1361.

(i) A brief description of the process change;

(ii) A description of any modifications to standard 

procedures or quality assurance procedures;

(iii) Revisions to any of the information reported in the 

original Notification of Compliance Status report under 

paragraph (f) of this section; and

(iv) Information required by the Notification of Compliance 

Status report under paragraph (f) of this section for changes 

involving the addition of processes or equipment.

(2) The owner or operator must submit a report 60 days 

before the scheduled implementation date of either of the 

following:

(i) Any change in the activity covered by the Precompliance 

report.

(ii) A change in the status of a control device from small 

to large.

(i) Reports of startup, shutdown, and malfunctions. If a 

source fails to meet an applicable standard, report such events 

in the Periodic Report. Report the number of failures to meet an 

applicable standard. For each instance, report the date, time,

and duration of each failure. For each failure the report must 

include a list of the affected sources or equipment, an estimate 
Page 250 of 267

of the quantity of each regulated pollutant emitted over any 

emission limit, and a description of the method used to estimate 

the emissions.For the purposes of this subpart, the startup, 

shutdown, and malfunction reports shall be submitted on the same 

schedule as the Periodic reports required under paragraph (g) of 

this section instead of the schedule specified in 

§63.10(d)(5)(i) of subpart A of this part. These reports shall 

include the information specified in §63.1367(a)(3)(i) through 

(iii) and shall contain the name, title, and signature of the 

owner or operator or other responsible official who is 

certifying its accuracy. Reports are only required if a startup, 

shutdown, or malfunction occurred during the reporting period. 

Any time an owner or operator takes an action that is not 

consistent with the procedures specified in the affected 

source's startup, shutdown, and malfunction plan, the owner or 

operator shall submit an immediate startup, shutdown, and 

malfunction report as specified in §63.10(d)(5)(ii) of subpart A 

of this part.

(j) Reports of equipment leaks. The owner or operator of an 

affected source subject to the standards in §63.1363, shall 

implement the reporting requirements specified in §63.1363(h). 

Copies of all reports shall be retained as records for a period 

of 5 years, in accordance with the requirements of §63.10(b)(1) 

of subpart A of this part.
Page 251 of 267

(k) Reports of emissions averaging. The owner or operator 

of an affected source that chooses to comply with the 

requirements of §63.1362(h) shall submit all information as 

specified in §63.1367(d) for all emission points included in the 

emissions average. The owner or operator shall also submit to 

the Administrator all information specified in paragraph (g) of 

this section for each emission point included in the emissions 

average.

(1) The reports shall also include the information listed 

in paragraphs (k)(1)(i) through (iv) of this section:

(i) Any changes to the processes, storage tanks, or waste 

management unit included in the average.

(ii) The calculation of the debits and credits for the 

reporting period.

(iii) Changes to the Emissions Averaging Plan which affect 

the calculation methodology of uncontrolled or controlled 

emissions or the hazard or risk equivalency determination.

(iv) Any changes to the parameters monitored according to 

§63.1366(g).

(2) Every second semiannual or fourth quarterly report, as 

appropriate, shall include the results according to 

§63.1367(d)(4) to demonstrate the emissions averaging provisions 

of §63.1362(h), §63.1365(h), §63.1366(g), and §63.1367(d) are 

satisfied.
Page 252 of 267

(l) Reports of heat exchange systems. The owner or operator 

of an affected source subject to the requirements for heat 

exchange systems in §63.1362(f) shall submit information about 

any delay of repairs as specified in §63.104(f)(2) of subpart F 

of this part, except that when the phrase “periodic reports 

required by §63.152(c) of subpart G of this part” is referred to 

in §63.104(f)(2) of subpart F of this part, the periodic reports 

required in paragraph (g) of this section shall apply for the 

purposes of this subpart.

(m) Notification of performance test and test Plan. The 

owner or operator of an affected source shall notify the 

Administrator of the planned date of a performance test at least 

60 days before the test in accordance with §63.7(b) of subpart A 

of this part. The owner or operator also must submit the test 

Plan required by §63.7(c) of subpart A of this part and the 

emission profile required by §63.1365(b)(11)(iii) with the 

notification of the performance test.

(n) Request for extension of compliance. The owner or 

operator may submit to the Administrator a request for an 

extension of compliance in accordance with §63.1364(a)(2).

(o) The owner or operator who submits an operating permit 

application before the date the Emissions Averaging Plan is due 

shall submit the information specified in paragraphs (o)(1) 
Page 253 of 267

through (3) of this section with the operating permit 

application instead of the Emissions Averaging Plan.

(1) The information specified in §63.1367(d) for emission 

points included in the emissions average;

(2) The information specified in §63.9(h) of subpart A of 

this part, as applicable; and

(3) The information specified in paragraph (e) of this 

section, as applicable.

(p) Electronic reporting. Within 60 days after the date of 

completing each performance test (as defined in §63.2), the 

owner or operator must submit the results of the performance 

tests, including any associated fuel analyses, required by this 

subpart according to the methods specified in paragraph (p)(1) 

or (2) of this section.

(1) For data collected using test methods supported by the 

EPA-provided software, the owner or operator shall submit the 

results of the performance test to the EPA by direct computerto-computer electronic transfer via EPA-provided software, 

unless otherwise approved by the Administrator. Owners or 

operators, who claim that some of the information being 

submitted for performance tests is confidential business 

information (CBI), must submit a complete file using EPAprovided software that includes information claimed to be CBI on 

a compact disk, flash drive, or other commonly used electronic 
Page 254 of 267

storage media to the EPA. The electronic media must be clearly 

marked as CBI and mailed to U.S. EPA/OAPQS/CORE CBI Office, 

Attention: WebFIRE Administrator, MD C404-02, 4930 Old Page Rd., 

Durham, NC 27703. The same file with the CBI omitted must be 

submitted to the EPA by direct computer-to-computer electronic 

transfer via EPA-provided software.

(2) For any performance test conducted using test methods 

that are not compatible with the EPA-provided software, the 

owner or operator shall submit the results of the performance 

test to the Administrator at the appropriate address listed in 

§60.4.

§63.1369 Implementation and enforcement.

(a) This subpart can be implemented and enforced by the 

U.S. EPA, or a delegated authority such as the applicable State, 

local, or Tribal agency. If the U.S. EPA Administrator has 

delegated authority to a State, local, or Tribal agency, then 

that agency, in addition to the U.S. EPA, has the authority to 

implement and enforce this subpart. Contact the applicable U.S. 

EPA Regional Office to find out if implementation and 

enforcement of this subpart is delegated to a State, local, or 

Tribal agency.

(b) In delegating implementation and enforcement authority 

of this subpart to a State, local, or Tribal agency under 

subpart E of this part, the authorities contained in paragraph 
Page 255 of 267

(c) of this section are retained by the Administrator of U.S. 

EPA and cannot be transferred to the State, local, or Tribal 

agency.

(c) The authorities that cannot be delegated to State, 

local, or Tribal agencies are as specified in paragraphs (c)(1) 

through (4) of this section.

(1) Approval of alternatives to the requirements in 

§§63.1360 and 63.1362 through 63.1364. Where these standards 

reference another subpart, the cited provisions will be 

delegated according to the delegation provisions of the 

referenced subpart. Where these standards reference another 

subpart and modify the requirements, the requirements shall be 

modified as described in this subpart. Delegation of the 

modified requirements will also occur according to the 

delegation provisions of the referenced subpart.

(2) Approval of major alternatives to test methods for 

under §63.7(e)(2)(ii) and (f), as defined in §63.90, and as 

required in this subpart.

(3) Approval of major alternatives to monitoring under 

§63.8(f), as defined in §63.90, and as required in this subpart.

(4) Approval of major alternatives to recordkeeping and 

reporting under §63.10(f), as defined in §63.90, and as required 

in this subpart.
Page 256 of 267

Table 1 to Subpart MMM of Part 63—General Provisions 

Applicability to Subpart MMM

Reference to 

subpart A

Applies 

to

subpart 

MMM Explanation

§63.1(a)(1) Yes Additional terms are defined in 

§63.1361.

§63.1(a)(2)–(3) Yes

§63.1(a)(4) Yes Subpart MMM (this table) specifies 

applicability of each paragraph in 

subpart A to subpart MMM.

§63.1(a)(5) N/A Reserved.

§63.1(a)(6)–(7) Yes

§63.1(a)(8) No Discusses State programs.

§63.1(a)(9) N/A Reserved.

§63.1(a)(10)–(14) Yes

§63.1(b)(1) No §63.1360 specifies applicability.

§63.1(b)(2)–(3) Yes

§63.1(c)(1) Yes Subpart MMM (this table) specifies the 

applicability of each paragraph in 

subpart A to sources subject to subpart 

MMM.

§63.1(c)(2) No Area sources are not subject to subpart 

MMM.

§63.1(c)(3) N/A Reserved.

§63.1(c)(4)–(5) Yes

§63.1(d) N/A Reserved.

§63.1(e) Yes

§63.2 Yes Additional terms are defined in 

§63.1361; when overlap between subparts 

A and MMM occurs, subpart MMM takes 

precedence.

§63.3 Yes Other units used in subpart MMM are 

defined in that subpart.
Page 257 of 267

§63.4(a)(1)–(3) Yes

§63.4(a)(4) N/A Reserved.

§63.4(a)(5)–(c) Yes

§63.5(a) Yes Except the term “affected source” shall 

apply instead of the terms “source” and 

“stationary source” in §63.5(a)(1) of 

subpart A.

§63.5(b)(1) Yes

§63.5(b)(2) N/A Reserved.

§63.5(b)(3)–(5) Yes

§63.5(b)(6) No §63.1360(g) specifies requirements for 

determining applicability of added PAI 

equipment.

§63.5(c) N/A Reserved.

§63.5(d)–(e) Yes

§63.5(f)(1) Yes Except “affected source” shall apply 

instead of “source” in §63.5(f)(1) of 

subpart A.

§63.5(f)(2) Yes

§63.6(a) Yes

§63.6(b)(1)–(2) No §63.1364 specifies compliance dates.

§63.6(b)(3)–(4) Yes

§63.6(b)(5) Yes

§63.6(b)(6) N/A Reserved.

§63.6(b)(7) Yes

§63.6(c)(1)–(2) Yes Except “affected source” shall apply 

instead of “source” in §63.6(c)(1)–(2) 

of subpart A.

§63.6(c)(3)–(4) N/A Reserved.

§63.6(c)(5) Yes

§63.6(d) N/A Reserved.

§63.6(e) Yes Except §63.1360 specifies that the 

standards in subpart MMM apply during 

startup and shutdown for batch 
Page 258 of 267

processes; therefore, these activities 

would not be covered in the startup, 

shutdown, and malfunction Plan.

63.6(e)(1)(i) No See §63.1360(e)(4) for general duty 

requirement.

§63.6(e)(1)(ii) No

§63.6(e)(1)(iii) Yes

§63.6(e)(3) No

§63.6(f) Yes Except §63.1360 specifies that the 

standards in subpart MMM also apply 

during startup and shutdown for batch 

processes.

§63.6(f)(1) No

§63.6(f)(2)-(3) Yes

§63.6(g) Yes An alternative standard has been 

proposed; however, affected sources 

will have the opportunity to 

demonstrate other alternatives to the 

Administrator.

§63.6(h) No Subpart MMM does not contain any 

opacity or visible emissions standards.

§63.6(i)(1) Yes

§63.6(i)(2) Yes Except “affected source” shall apply 

instead of “source” in §63.6(i)(2)(i) 

and (ii) of subpart A.

§63.6(i)(3)–(14) Yes

§63.6(i)(15) N/A Reserved.

§63.6(i)(16) Yes

§63.6(j) Yes

§63.7(a)(1) Yes

§63.7(a)(2)(i)–

(vi)

Yes §63.1368 specifies that test results 

must be submitted in the Notification 

of Compliance Status due 150 days after 

the compliance date.

§63.7(a)(2)(vii)–

(viii)

N/A Reserved.
Page 259 of 267

§63.7(a)(2)(ix)–

(c)

Yes

§63.7(d) Yes Except “affected source” shall apply 

instead of “source” in §63.7(d) of 

subpart A.

§63.7(e)(1) YesNo §63.1365 contains test methods specific 

to PAI sources.See §63.1365(b).

§63.7(e)(2) Yes

§63.7(e)(3) Yes Except §63.1365 specifies less than 3 

runs for certain tests.

§63.7(e)(4) Yes.

§63.7(f) Yes

§63.7(g)(1) Yes Except §63.1368(a) specifies that the 

results of the performance test be 

submitted with the Notification of 

Compliance Status report

§63.7(g)(2) N/A Reserved.

§63.7(g)(3) Yes

§63.7(h) Yes

§63.8(a)(1)–(2) Yes

§63.8(a)(3) N/A Reserved.

§63.8(a)(4) Yes

§63.8(b)(1) Yes

§63.8(b)(2) No §63.1366 specifies CMS requirements.

§63.8(b)(3)–

(c)(3)

Yes Except the submittal date of the 

immediate startup, shutdown, and 

malfunction reports for CMS events 

shall be 2 days as in §63.6(e)(3)(iv).

§63.8(b)(3) Yes

§63.8(c)(1)(i) No

§63.8(c)(1)(ii) Yes

§63.8(c)(1)(iii) No

§63.8(c)(2)-(3) Yes

§63.8(c)(4) No §63.1366 specifies monitoring 
Page 260 of 267

frequencies.

§63.8(c)(5)–(8) No

§63.8(d)–(f)(3) Yes Except the last sentence of 

§63.8(d)(3), which shall be replaced 

with “The program of corrective action 

should be included in the plan required 

under §63.8(d)(2).” for the purposes of 

this subpart.

§63.8(f)(4) Yes Except §63.1368(b) specifies that 

requests may also be included in the 

Precompliance report.

§63.8(f)(5) Yes

§63.8(f)(6) No Subpart MMM does not require CEM's.

§63.8(g) No §63.1366 specifies data reduction 

procedures.

§63.9(a)–(d) Yes

§63.9(e) No

§63.9(f) No Subpart MMM does not contain opacity 

and visible emission standards.

§63.9(g) No

§63.9(h)(1) Yes

§63.9(h)(2)(i) Yes Except §63.1368(a)(1) specifies 

additional information to include in 

the Notification of Compliance Status 

report.

§63.9(h)(2)(ii) No §63.1368 specifies the Notification of 

Compliance Status report is to be 

submitted within 150 days after the 

compliance date.

§63.9(h)(3) Yes

§63.9(h)(4) N/A Reserved.

§63.9(h)(5)–(6) Yes

63.9(i) Yes.

63.9(j) No §63.1368(h) specifies procedures for 

notification of changes.

§63.10(a)–(b)(1) Yes
Page 261 of 267

§63.10(b)(2) No §63.1367 specifies recordkeeping 

requirements.

§63.10(b)(3) Yes

§63.10(c) Yes

§63.10(c)(1)-(14) Yes

§63.10(c)(15) No

§63.10(d)(1) Yes

§63.10(d)(2) Yes

§63.10(d)(3) No Subpart MMM does not include opacity 

and visible emission standards.

§63.10(d)(4) Yes

§63.10(d)(5) YesNo Except that actions and reporting for 

batch processes do not apply during 

startup and shutdown.See §63.1368(i) 

for malfunction reporting requirements.

§63.10(e)(1)–

(2)(i)

Yes

§63.10(e)(2)(ii) No Subpart MMM does not include opacity 

monitoring requirements.

§63.10(e)(3) Yes

§63.10(e)(4) No Subpart MMM does not include opacity 

monitoring requirements.

§63.10(f) Yes

§63.11–§63.15 Yes

Table 2 to Subpart MMM of Part 63—Standards for New and Existing 

PAI Sources

Emission 

source Applicability Requirement

Process 

vents

Existing:

Processes having uncontrolled 

organic HAP emissions ≥ 0.15 

Mg/yr

90% for organic HAP 

per process or to 

outlet concentration 

of ≤ 20 ppmv TOC.
Page 262 of 267

Processes having uncontrolled 

HCl and chlorine emissions ≥ 

6.8 Mg/yr

94% for HCl and 

chlorine per process 

or to outlet HCl and 

chlorine 

concentration of ≤ 20 

ppmv.

Individual process vents 

meeting flow and mass 

emissions criteria that have 

gaseous organic HAP emissions 

controlled to less than 90% on 

or after November 10, 1997

98% gaseous organic 

HAP control per vent 

or ≤ 20 ppmv TOC 

outlet limit.

New:

Processes having uncontrolled 

organic HAP emissions ≥ 0.15 

Mg/yr

98% for organic HAP 

per process or ≤ 20 

ppmv TOC.

Processes having uncontrolled 

HCl and chlorine emissions ≥ 

6.8 Mg/yr and < 191 Mg/yr

94% for HCl and 

chlorine per process 

or to outlet 

concentration of ≤ 20 

ppmv HCl and 

chlorine.

Processes having uncontrolled 

HCl and chlorine emissions ≥ 

191 Mg/yr

99% for HCl and 

chlorine per process 

or to outlet 

concentration of ≤ 20 

ppmv HCl and 

chlorine.

Storage 

vessels

Existing: ≥ 75 m3 capacity and 

vapor pressure ≥ 3.45 kPa

Install a floating 

roof, reduce HAP by 

95% per vessel, or to 

outlet concentration 

of ≤20 ppmv TOC.

New: ≥ 38 m3 capacity and vapor 

pressure ≥ 16.5 kPa

Same as for existing 

sources.

≥ 75 m3 capacity and vapor 

pressure ≥ 3.45 kPa

Same as for existing 

sources.

Wastewatera Existing: Process wastewater 

with ≥10,000 ppmw Table 9 

compounds at any flowrate or 

≥1,000 ppmw Table 9 compounds 

Reduce concentration 

of total Table 9 

compounds to <50 ppmw 

(or other options).
Page 263 of 267

at ≥10 L/min, and maintenance 

wastewater with HAP load ≥5.3

Mg per discharge event

New:

Same criteria as for existing 

sources

Reduce concentration 

of total Table 9 

compounds to <50 ppmw 

(or other options).

Total HAP load in wastewater 

POD streams ≥2,100 Mg/yr.

99% reduction of 

Table 9 compounds 

from all streams.

Equipment 

leaks

Subpart H Subpart H with minor 

changes, including 

monitoring 

frequencies 

consistent with the 

proposed CAR.

Product 

dryers and 

bag dumps

Dryers used to dry PAI that is 

also a HAP, and bag dumps used 

to introduce feedstock that is 

a solid and a HAP

Particulate matter 

concentration not to 

exceed 0.01 gr/dscf.

Heat 

exchange 

systems

Each heat exchange system used 

to cool process equipment in 

PAI manufacturing operations

Monitoring and leak 

repair program as in 

HON.

aTable 9 is listed in the appendix to subpart G of 40 CFR part 

63.

Table 3 to Subpart MMM of Part 63—Monitoring Requirements for 

Control Devicesa

Control device

Monitoring 

equipment 

required

Parameters to 

be monitored Frequency

All control devices1. Flow 

indicator 

installed at 

all bypass 

lines to the 

atmosphere and 

equipped with 

continuous 

1. Presence of 

flow diverted 

from the 

control device 

to the 

atmosphere or

Hourly records 

of whether the 

flow indicator 

was operating 

and whether a 

diversion was 

detected at any 

time during 
Page 264 of 267

recorder or each hour.

2. Valves 

sealed closed 

with car-seal 

or lock-and-key 

configuration

2. Monthly 

inspections of 

sealed valves

Monthly.

Scrubber Liquid flow 

rate or 

pressure drop 

mounting 

device. Also a 

pH monitor if 

the scrubber is 

used to control 

acid emissions.

1. Liquid flow 

rate into or 

out of the 

scrubber or 

the pressure 

drop across 

the scrubber.

1. Every 15 

minutes.

2. pH of 

effluent 

scrubber 

liquid

2. Once a day.

Thermal incineratorTemperature 

monitoring 

device 

installed in 

firebox or in 

ductwork 

immediately 

downstream of 

fireboxb

Firebox 

temperature

Every 15 

minutes.

Catalytic 

incinerator

Temperature 

monitoring 

device 

installed in 

gas stream 

immediately 

before and 

after catalyst 

bed

Temperature 

difference 

across 

catalyst bed

Every 15 

minutes.

Flare Heat sensing 

device 

installed at 

the pilot light

Presence of a 

flame at the 

pilot light

Every 15 

minutes.

Boiler or process 

heater <44 

Temperature 

monitoring 

Combustion 

temperature

Every 15 

minutes.
Page 265 of 267

megawatts and vent 

stream is not mixed 

with the primary 

fuel

device 

installed in 

fireboxb

Condenser Temperature 

monitoring 

device 

installed at 

condenser exit

Condenser exit 

(product side) 

temperature

Every 15 

minutes.

Carbon adsorber 

(nonregenerative)

None Operating time 

since last 

replacement

N/A.

Carbon adsorber 

(regenerative)

Stream flow 

monitoring 

device, and

1. Total 

regeneration 

stream mass or 

volumetric 

flow during 

carbon bed 

regeneration 

cycle(s)

1. For each 

regeneration 

cycle, record 

the total 

regeneration 

stream mass or 

volumetric 

flow.

Carbon bed 

temperature 

monitoring 

device

2. Temperature 

of carbon bed 

after 

regeneration

2. For each 

regeneration 

cycle, record 

the maximum 

carbon bedtemperature.

3. Temperature 

of carbon bed 

within 15 

minutes of 

completing any 

cooling 

cycle(s)

3. Within 15 

minutes of 

completing any 

cooling cycle, 

record the 

carbon bed 

temperature.

4. Operating 

time since end 

of last 

regeneration

4. Operating 

time to be 

based on worstcase 

conditions.

5. Check for 

bed poisoning

5. Yearly.

aAs an alternative to the monitoring requirements specified in 

this table, the owner or operator may use a CEM meeting the 
Page 266 of 267

requirements of Performance Specifications 8 or 9 of appendix B 

of part 60 to monitor TOC every 15 minutes.

bMonitor may be installed in the firebox or in the ductwork 

immediately downstream of the firebox before any substantial 

heat exchange is encountered.

Table 4 to Subpart MMM of Part 63—Control Requirements for Items 

of Equipment That Meet the Criteria of §63.1362(k)

Item of 

equipment Control requirementa

1. Drain or 

drain hub

(a) Tightly fitting solid cover (TFSC); or

(b) TFSC with a vent to either a process, or to a 

control device meeting the requirements of 

§63.139(c); or

(c) Water seal with submerged discharge or barrier to 

protect discharge from wind.

2. Manholeb (a) TFSC; or

(b) TFSC with a vent to either a process or to a 

control device meeting the requirements of 

§63.139(c); or

(c) If the item is vented to the atmosphere, use a 

TFSC with a properly operating water seal at the 

entrance or exit to the item to restrict ventilation 

in the collection system. The vent pipe shall be at 

least 90 cm in length and not exceeding 10.2 cm in 

nominal inside diameter.

3. Lift 

station

(a) TFSC; or

(b) TFSC with a vent to either a process, or to a 

control device meeting the requirements of 

§63.139(c); or

(c) If the lift station is vented to the atmosphere, 

use a TFSC with a properly operating water seal at 

the entrance or exit to the item to restrict 

ventilation in the collection system. The vent pipe 

shall be at least 90 cm in length and not exceeding 

10.2 cm in nominal inside diameter. The lift station

shall be level controlled to minimize changes in the 

liquid level.

4. Trench (a) TFSC; or

(b) TFSC with a vent to either a process, or to a 

control device meeting the requirements of 

§63.139(c); or
Page 267 of 267

(c) If the item is vented to the atmosphere, use a 

TFSC with a properly operating water seal at the 

entrance or exit to the item to restrict ventilation 

in the collection system. The vent pipe shall be at 

least 90 cm in length and not exceeding 10.2 cm in 

nominal inside diameter.

5. Pipe Each pipe shall have no visible gaps in joints, 

seals, or other emission interfaces.

6. 

Oil/water 

separator

(a) Equip with a fixed roof and route vapors to a 

process, or equip with a closed-vent system that 

routes vapors to a control device meeting the 

requirements of §63.139(c); or

(b) Equip with a floating roof that meets the 

equipment specifications of §60.693 (a)(1)(i), 

(a)(1)(ii), (a)(2), (a)(3), and (a)(4).

7. Tank Maintain a fixed roof and consider vents as process 

vents.c

aWhere a tightly fitting solid cover is required, it shall be 

maintained with no visible gaps or openings, except during 

periods of sampling, inspection, or maintenance.

bManhole includes sumps and other points of access to a 

conveyance system.

cA fixed roof may have openings necessary for proper venting of 

the tank, such as pressure/vacuum vent, j-pipe vent.