Document ID: EPA-R01-OAR-2020-0719-0021
Agency: epa
Document Type: Rule
Title: Air Quality State Implementation Plans; Approvals and Promulgations: Connecticut; Regulations to Limit Premises-Wide Actual and Potential Emissions from Major Stationary Sources of Air Pollution
Posted Date: 2022-03-11T05:00Z

[Federal Register Volume 87, Number 48 (Friday, March 11, 2022)]
[Rules and Regulations]
[Pages 13936-13945]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2022-05042]

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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 52

[EPA-R01-OAR-2020-0719; FRL-9530-01-R1]

Air Plan Approval; Connecticut; Regulations To Limit Premises-
Wide Actual and Potential Emissions From Major Stationary Sources of 
Air Pollution

AGENCY: Environmental Protection Agency (EPA).

ACTION: Final rule.

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SUMMARY: The Environmental Protection Agency (EPA) is approving a State 
Implementation Plan (SIP) revision submitted by the State of 
Connecticut. This revision approves into the Connecticut SIP state 
regulations that apply restrictions on emissions of criteria pollutants 
for which EPA has established National Ambient Air Quality Standards. 
Separately, we are also approving Connecticut regulations that apply 
restrictions on emissions of hazardous air pollutants (HAPs). The 
Connecticut regulations impose legally and practicably enforceable 
emissions limitations restricting eligible sources' actual and 
potential emissions below major stationary source thresholds, if a 
source chooses to be covered by the regulations. Such restrictions 
generally allow eligible sources to avoid having to comply with 
reasonably available control technology (RACT) that would otherwise 
apply to major stationary sources, title V operating permit 
requirements, or other requirements that apply only to major stationary 
sources. This action is being taken under the Clean Air Act.

DATES: This rule is effective on April 11, 2022. The incorporation by 
reference of certain publications listed in the rule is approved by the 
Director of the Federal Register as of April 11, 2022.

ADDRESSES: EPA has established a docket for this action under Docket 
Identification No. EPA-R01-OAR-2020-0719. All documents in the docket 
are listed on the https://www.regulations.gov website. Although listed 
in the index, some information is not publicly available, i.e., 
confidential business information (CBI) or other information whose 
disclosure is restricted by statute. Certain other material, such as 
copyrighted material, is not placed on the internet and will be 
publicly available only in hard copy form. Publicly available docket 
materials are available at https://www.regulations.gov or at the U.S. 
Environmental Protection Agency, EPA Region 1 Regional Office, Air and 
Radiation Division, 5 Post Office Square--Suite 100, Boston, MA. EPA 
requests that if at all possible, you contact the contact listed in the 
FOR FURTHER INFORMATION CONTACT section to schedule your inspection. 
The Regional Office's official hours of business are Monday through 
Friday, 8:30 a.m. to 4:30 p.m., excluding legal holidays and facility 
closures due to COVID-19.

FOR FURTHER INFORMATION CONTACT: Susan Lancey, Air Permits, Toxics and 
Indoor Programs Branch, U.S. Environmental Protection Agency, EPA 
Region 1, 5 Post Office Square--Suite 100, (Mail code 05-2), Boston, MA 
02109-3912, telephone 617-918-1656, email [email protected].

SUPPLEMENTARY INFORMATION: Throughout this document whenever ``we,'' 
``us,'' or ``our'' is used, we mean EPA.

Table of Contents

I. Background and Purpose
II. Response to Comments
III. Final Action
IV. Incorporation by Reference
V. Statutory and Executive Order Reviews

I. Background and Purpose

    On February 8, 2021 (86 FR 8574), EPA published a notice of 
proposed rulemaking (NPRM) for the State of Connecticut.
    The NPRM proposed approval of a SIP revision consisting of 
Regulations of Connecticut State Agencies (RCSA) section 22a-174-33a, 
Limit on Premises-wide Actual Emissions Below 50% of Title V 
Thresholds, effective September 24, 2020, and RCSA section 22a-174-33b, 
Limit on Premises-wide Actual Emissions Below 80% of Title V 
Thresholds, effective September 24, 2020, as the regulations relate to 
criteria pollutants. The Connecticut regulations impose legally and 
practicably enforceable emissions limitations restricting eligible 
sources' actual and potential emissions below major stationary source 
thresholds, if a source chooses to be covered by the regulations. The 
NPRM separately proposed approval of RCSA sections 22a-174-33a and 22a-
174-33b under section 112(l) of the CAA, as the regulations relate to 
HAPs. As noted earlier, RCSA sections 22a-174-33a and 22a-174-33b are 
designed to limit air pollutant emissions from major stationary sources 
to below major stationary source thresholds by including legally and 
practicably enforceable restrictions on potential and actual emissions.
    The formal SIP revision was submitted by Connecticut on October 26, 
2020, supplemented on January 12, 2022. In the January 12, 2022 letter, 
Connecticut requested to withdraw provision RCSA 22a-174-33b(d)(6) from 
consideration as part of the SIP, clarified its interpretation of 
several provisions, and provided additional information concerning 
implementation of the regulations.
    Connecticut submitted a December 21, 2020 letter requesting 
approval of RCSA sections 22a-174-33a and 22a-174-33b under section 
112(l) of the CAA.
    The rationale for EPA's proposed approval of the SIP revision and 
CAA 112(l) submittal is explained in the NPRM and will not be restated 
here.

II. Response to Comments

    We received three comments that supported this action. One 
commenter stated that they support approval of the rule. One commenter 
stated it is important that air quality plans are passed and that clean 
air quality is crucial for anyone in any state. One commenter supports 
approval of the rule and believes that a limit on emissions should 
occur because of concerns that an increase of pollution affects air 
quality; the commenter also made additional statements not germane to 
this action. The following provides our responses to adverse comments 
received.
    Comment 1: The commenter could not access the docket for this 
rulemaking and could not find any results on Regulations.gov.
    Response: The docket was available on February 8, 2021, the 
publication date of the proposal. The commenter emailed comments on 
February 7th, after the pre-publication proposed rule was posted, but 
one day prior to the proposed rule's publication in the Federal 
Register on February 8th. The docket only becomes available on the 
actual date that a Rulemaking publishes in the Federal Register, and 
that it is typically available by 10 a.m. EST. We informed the 
commenter on February 8th that the docket was available.
    Comment 2: The commenter was concerned that RCSA section 22a-174-

[[Page 13937]]

33a ignores, in the definition of Hazardous Air Pollutant (HAP) in 
section (a)(4), HAPs added to the CAA 112(b) HAPs list. The commenter 
pointed out that there are several petitions in front of EPA, being 
reconsidered by EPA, or headed for or in litigation to add HAPs to the 
HAPs list. The commenter asserted that 22a-174-33a would ignore these 
added HAPs and thus isn't approvable. The commenter stated that without 
a change in the regulation to address this issue, sources could be over 
the major source threshold, and would not be covered by the regulation, 
by virtue of a HAP which is added to the HAP list but does not appear 
in CAA 112(b). The commenter submitted the same comment in relation to 
Connecticut's regulation at RCSA 22a-174-33b.
    Response: The definition of Hazardous Air Pollutant (HAP) in 
Section 22a-174-33a(a)(4) and 33b(a)(10) means ``notwithstanding the 
definition in Section 22a-174-1 of the Regulations of Connecticut State 
Agencies (RCSA), any air pollutant listed in section 112(b) of the 
Federal Clean Air Act excluding any air pollutants that are removed 
from such list.'' We agree that Connecticut's definition does not 
include air pollutants that are added to the list. However, this should 
not be a reason to disapprove Connecticut's requested CAA 112(l) 
submission. On January 5, 2022, EPA added a new HAP, 1-bromopropane, to 
the CAA HAP list by amending 40 CFR part 63, subpart C. (See 87 FR 393) 
As a result, Connecticut should now amend its regulations to add 1-
bromopropane to its definition of Hazardous Air Pollutant so that 
sources emitting 1-bromopropane may be covered by Connecticut's 
regulation. EPA could then approve a subsequent State submittal 
including 1-bromopropane under Section 112(l). It is not a legal 
requirement of the CAA that all sources be regulated by the regulation 
in question. A source that is a major source if not regulated pursuant 
to this CAA 112(l) approval will have to comply with any applicable 
major source requirements unless and until Connecticut amends its rule 
to include the added HAP. In a letter dated January 12, 2022, 
Connecticut Department of Energy and Environmental Protection (DEEP) 
clarified its implementation with respect to HAPs added to the HAP 
list. Connecticut's January 12, 2022 letter provided that ``To the 
extent that a hazardous air pollutant (HAP) is added to the Clean Air 
Act (CAA) HAP list but does not appear in CAA Section 112(b), if DEEP 
identifies a facility with potential emissions of such a HAP not listed 
in CAA Section 112(b), DEEP shall not allow such facility to operate 
under RCSA section 22a-174-33a or RCSA section 22a-174-33b until such 
time as DEEP adopts regulatory revisions to include such a newly listed 
HAP within the definitions that apply to RCSA sections 22a-174-33a and 
22a-174-33b. As 1-bromopropane has recently been added to the CAA list 
of HAPs and does not appear in CAA Section 112(b), neither RCSA section 
22a-174-33a nor RCSA section 22a-174-33b is a regulatory compliance 
option available for a facility that emits 1-bromopropane to limit the 
potential to emissions [sic] of criteria pollutants and hazardous air 
pollutants.'' Thus, the commenter's concerns are unwarranted.
    Comment 3: The commenter was concerned that section (d)(1) of 
Connecticut's regulation ignores VOC and NOX emissions in 
areas that are marginal, moderate, or extreme ozone nonattainment 
areas, as well as areas designated attainment but located inside the 
ozone transport region. Connecticut currently contains one marginal 
ozone nonattainment area and one moderate nonattainment area for the 
2015 ozone National Ambient Air Quality Standard (NAAQS). The commenter 
asserted that the fact that those areas are currently designated as 
serious nonattainment areas for the 2008 ozone NAAQS does not fix this 
problem as that could change in the future if those areas were 
redesignated to attainment for the 2008 ozone NAAQS. The commenter 
believes the current rule would leave a gap by not placing emission 
limits on NOX and VOC emissions and thus is not approvable. 
The commenter asserts that the same is true if those areas were to be 
``bumped up'' to extreme nonattainment areas for the 2008 ozone NAAQS. 
The same comment was submitted for Connecticut's regulation at RCSA 
22a-174-33b.
    Response: By definition, any source in Connecticut eligible to be 
regulated by this rule could avail itself of the limits contained 
within the regulation. The definition of ``Serious non-attainment area 
for ozone'' in Connecticut's SIP-approved regulation at RCSA Section 
22a-174-1 means ``all towns within the State of Connecticut, except 
those towns located in the severe non-attainment area for ozone.'' The 
SIP-approved definition of ``Severe non-attainment area for ozone'' in 
Connecticut's regulation at RCSA 22a-174-1 means the towns of Bethel, 
Bridgeport, Bridgewater, Brookfield, Danbury, Darien, Easton, 
Fairfield, Greenwich, Monroe, New Canaan, New Fairfield, New Milford, 
Newtown, Norwalk, Redding, Ridgefield, Sherman, Stamford, Stratford, 
Trumbull, Weston, Westport, and Wilton. These serious and severe non-
attainment areas, as defined, represent Connecticut's nonattainment 
area classifications under the one-hour ozone standard, encompassing 
all locations in the State of Connecticut and thereby all sources 
eligible to be regulated by this rule. Because Connecticut's 
regulations define all areas as serious nonattainment for ozone, except 
for towns located in a severe nonattainment area for ozone, the state 
definitions are equivalent to or more stringent than the current 
classifications under the 2008 and 2015 ozone standards. EPA can 
request in the future that Connecticut amend its regulation if any area 
in Connecticut were to be reclassified. Reclassifying an area, for 
example from serious to severe, would be done through a proposed and 
final rulemaking process. Connecticut would then have to make any 
regulatory changes as needed. In addition, in a letter dated January 
12, 2022, Connecticut stated that ``To the extent that EPA changes the 
ozone attainment designations applicable to Connecticut, DEEP will act 
with all due haste to make necessary revisions to the relevant 
definitions in Connecticut's regulations and in the SIP.''
    Comment 4: The commenter was concerned that RCSA 33a(d)(4)(F) is a 
``director's discretion'' provision which the commenter asserted is 
illegal. The same comment was submitted for Connecticut's regulation at 
RCSA 22a-174-33b(d)(4)(F).
    Response: Connecticut's regulations at sections 33a(d)(4)(F) and 
33b(d)(4)(F) provide that ``if the data in subparagraphs (A), (B), (C), 
(D) and (E) of this subdivision are unavailable, the emission rate 
shall be calculated using another source of emissions data that is 
approved by the Commissioner and the Administrator. Such approval shall 
be obtained prior to operating in accordance with this section.'' In a 
letter dated January 12, 2022, Connecticut clarified implementation of 
these provisions. Connecticut stated that ``Sections 22a-174-
33a(d)(4)(F) and 22a-174-33b(d)(4)(F) of the Regulations of Connecticut 
State Agencies (RCSA) are the final alternatives in a hierarchy of data 
acceptable for a source owner to determine actual emissions. The two 
provisions allow for the use of data not otherwise specified in the 
hierarchy with the prior approval of the Commissioner and 
Administrator. DEEP understands the approval of the Commissioner and 
Administrator to be achieved via DEEP's submission of a

[[Page 13938]]

single-source SIP revision that would be subject to the procedural 
requirements of 40 CFR part 51, subpart F, and DEEP will proceed 
according to this understanding should any requests be received under 
one of these two provisions. DEEP further understands that such 
exercise of discretion will not have an effect on the existing SIP 
requirement until such time as the single-source SIP revision has been 
approved by the Administrator.'' The commenters concerns are 
unwarranted because any alternatives approved by EPA and DEEP under 
RCSA Sections 33a(d)(4)(F) or 33b(d)(4)(F) would be accomplished by a 
SIP revision with an opportunity for public review and comment.
    Comment 5: The commenter stated that the regulations are not 
enforceable as a practical matter because they do not ensure actual 
emissions stay below the thresholds in section (d)(1) of the 
regulation. Section (d)(4)(A) requires the use of a Continuous Emission 
Monitoring System (CEMS) if the data is available. The commenter was 
concerned that while CEMS are a good monitoring method, Section 
(d)(4)(A) does not require data substitution or gap filling when CEMS 
data for certain time periods are not available, and potential to emit 
and actual emissions that trigger title V and reasonably available 
control technology (RACT) applicability don't allow for ignoring 
emissions. The commenter asserted that, for example, CEMS are often not 
required to gather data during periods of startup and shutdown even 
though some emission sources, such as combustion devices, can have 
substantially higher emissions during those periods. The commenter 
cites generally to Weiler v. Chatham Forest Products, 392 F.3d 532, 535 
(2nd Cir. 2004). Also, the commenter stated that CEMS have downtime, 
both planned downtime to do testing and also unplanned downtime, and 
section (d)(4)(A) of Connecticut's regulation does not address these 
situations so it would be arbitrary and capricious for EPA to approve 
this regulation.
    The commenter was concerned that Section (d)(4)(B) suffers from 
similar flaws as discussed above but much worse. For example, the 
commenter asserted that stack tests are not performed during startups 
or shutdowns. The commenter stated that by using stack test data to 
calculate ``actual'' emissions on an annual basis, Section (d)(4)(B) 
ignores an important part of the problem, that is actual emissions 
during periods of startup, shutdown, process malfunctions, control 
equipment malfunctions or operations at different parameters that are 
not startup and shutdown. The commenter stated that the problem isn't 
limited to startup or shutdown. The commenter stated that the fact that 
a source emitted at a certain rate during a stack test does not prove 
that a source emits at that same rate every other hour that it 
operates. The commenter stated that this flaw is further compounded by 
the lack of a requirement for the frequency of stack testing, because a 
stack test performed 20 years ago, for example, provides no reliable 
data on current emissions.
    The commenter was concerned that Section (d)(4)(C) of Connecticut's 
regulation suffers from the same problems discussed above but noted 
that it also ignores a host of other considerations. The commenter 
questioned whether, for example, the source that is going to use this 
rule is defective in some way or not properly installed. The commenter 
stated that if that is the case, the manufacturers' testing doesn't 
provide reliable data on emissions from the source in question. The 
commenter pointed to the introduction section of AP-42, Compilation of 
Air Pollutant Emission Factors, which states ``Average emissions differ 
significantly from source to source and, therefore, emission factors 
frequently may not provide adequate estimates of the average emissions 
for a specific source. The extent of between-source variability that 
exists, even among similar individual sources, can be large depending 
on process, control system, and pollutant. Although the causes of this 
variability are considered in emission factor development, this type of 
information is seldom included in emission test reports used to develop 
AP-42 factors.'' As a result, some emission factors are derived from 
tests that may vary by an order of magnitude or more. Similarly, the 
commenter was concerned whether the conditions of the source in any way 
match the conditions of the manufacturer's test. The commenter stated 
that if the manufacturer did its testing in a high-altitude desert, 
that could create radically different conditions from sea level winter 
conditions than a source in Connecticut faces. The commenter stated 
that this difference in altitude and weather can result in very 
different combustion and evaporation conditions which change emissions.
    The commenter was concerned that Sections (d)(4)(D) and (E) are 
much worse than prior sections of Connecticut's regulation and use 
calculations which are in no way rationally related to actual 
emissions. The commenter believes that these sections allow the use of 
absolutely no actual emissions data to determine ``actual'' emissions 
and that they suffer from most of the same faults discussed above. 
Furthermore, the commenter questioned how a pertinent material balance 
would account for thermal NOX emissions, that is 
NOX that is formed in combustion processes because our air 
is 78% nitrogen, regardless of the composition of the fuel. The 
commenter stated that thermal NOX formation is greatly 
influenced by temperature in combustion processes but (d)(4)(D) does 
not require any parametric monitoring, much less restrictions, on 
operating temperature. Thus, the commenter states the rule is ignoring 
this important aspect of the problem such that the calculated emissions 
from application of (d)(4)(D) would not be rationally related to actual 
emissions. As to AP-42, the commenter stated that EPA's position has 
been that AP-42 should not be used for ensuring compliance with 
synthetic minor limits. The commenter stated that AP-42 clearly states 
that it is used for ``estimating emissions'', See, e.g., AP-42 
Introduction at 1, but a synthetic minor limit is not an estimate. The 
commenter stated that actual and potential to emit emissions have to be 
below the applicable threshold. The commenter asserted that actual 
emissions and an estimate of emissions are two separate things; that 
AP-42 emission factors come with ratings. The commenter stated that a 
``D'' rating is below average and an ``E'' rating is poor. See AP-42 
Introduction at 10. The commenter stated that Section (d)(4)(E) allows 
the use of even emission factors which EPA itself describes as 
``Poor'', and it is arbitrary for EPA to allow the use of ``Poor'' 
``estimates'' to provide actual emissions.
    Therefore, the commenter believes EPA must disapprove this SIP 
submittal.
    The commenter submitted the same comments in relation to 
Connecticut's regulation at RCSA 22a-174-33b.
    Response: The Commenter asserts that ``the regulations are not 
enforceable as a practical matter because they do not ensure actual 
emissions stay below the thresholds in section (d)(1).'' As a general 
matter, a source may avoid treatment as a major source if its 
``potential to emit'' (PTE) pollutants is below the relevant major 
source thresholds. See for example the definition of ``major source'' 
in 40 CFR part 63, subpart A, and 40 CFR 70.2. In addition, 40 CFR 63.2 
defines ``potential to emit'' as the maximum capacity of a stationary 
source to emit a pollutant under its physical and operational design. 
Any physical or operational limitation on the capacity of the

[[Page 13939]]

stationary source to emit a pollutant, including air pollution control 
equipment and restrictions on hours of operation or on the type or 
amount of material combusted, stored, or processed, shall be treated as 
part of its design if the limitation or the effect it would have on 
emissions is enforceable. The Connecticut regulations under RCSA 
section 22a-174-33a allow sources to elect to comply with emission 
limitations set at 50% of the title V operating permit program 
thresholds for a major source; or, alternatively, under RCSA section 
22a-174-33b, certain specified source categories may commit to be 
limited to emissions up to, but no more than, 80% of the title V 
operating permit program thresholds for a major stationary source 
provided the owner or operator conducts the additional specified 
monitoring and any other additional requirements required by RCSA 22a-
174-33b for the relevant source category. The commenter essentially 
maintains that the limits in question are not enforceable because of 
flawed or inadequate methods for determining compliance with the 
applicable limits.
    Connecticut's RCSA sections 22a-174-33a and 22a-174-33b require the 
owner or operator committing to operate pursuant to the applicable 
regulations to submit a notification to the State and to keep records 
that include, among other things, calculation of a source's actual 
emissions on a monthly and 12-month rolling basis for regulated air 
pollutants and a detailed description of the methodology used to 
calculate those actual emissions. The methodology used by an eligible 
source to calculate emissions must be selected from a preferential 
hierarchy of methodologies explicitly identified in the regulations.
    The commenter cites generally to Weiler v. Chatham Forest Products, 
392 F.3d 532, 535 (2nd Cir. 2004), which held that a group of citizens 
could bring an action under CAA 304(a)(3) against an owner or operator 
of a proposed source for which New York had issued a synthetic minor 
source construction permit, where the citizens contended that the 
controls or limitations on the source's potential to emit were neither 
practicably effective nor enforceable and where the source was to be 
constructed in a nonattainment area. The Court concluded that the plain 
language of the CAA allowed citizen suits to challenge a state's 
determination that no major source permit is necessary. In reaching 
this conclusion, the Court reviewed EPA's treatment of a source's 
``potential to emit,'' as relevant to determining whether a source is a 
major source, and summarized EPA's position that a source that 
otherwise might be considered a major emitting facility may be treated 
as not such a source if ``there are legally and practicably enforceable 
mechanisms in place to make certain that the emissions remain below the 
relevant levels.'' The Court did not reach the question of whether the 
controls or limitations at issue in New York were ``legally and 
practicably enforceable.'' Connecticut's regulation is legally 
enforceable because it was properly promulgated under state law. In 
addition, Connecticut's regulation states that no owner or operator of 
any premises operating in accordance with the rule shall cause or allow 
the emission of any regulated air pollutant during each and every 
consecutive 12-month period to be equal to or exceed the emission 
limitations in the regulation.
    Connecticut's approach was developed in accordance with an EPA 
guidance document titled ``Options for Limiting Potential to Emit of a 
Stationary Source under Section 112 and Title V of the Clean Air Act,'' 
issued by John Seitz, Office of Air Quality Planning and Standards 
(OAQPS) to EPA Air Division Directors, dated January 25, 1995 \1\ 
(January 25, 1995 OAQPS PTE memorandum). This guidance lays out the key 
criteria for practical enforceability of limits on PTE, which EPA later 
incorporated into its rationale, in part, for the 2002 New Source 
Review (NSR) Reform rule (2002 final rule).\2\ In the 2002 final rule, 
EPA stated that practical enforceability for a source-specific permit 
will be achieved if the permit's provisions specify: (1) A technically-
accurate limitation and the portions of the source subject to the 
limitation; (2) the time period for the limitation (hourly, daily, 
monthly, and annual limits such as rolling annual limits); and (3) the 
method to determine compliance, including appropriate monitoring, 
recordkeeping, and reporting. For rules and general permits that apply 
to categories of sources, practicable enforceability additionally 
requires that the provisions: (1) Identify the types or categories of 
sources that are covered by the rule; (2) where coverage is optional, 
provide for notice to the permitting authority of the source's election 
to be covered by the rule; and (3) specify the enforcement consequences 
relevant to the rule. EPA also stated in the 2002 final rule that `` 
`[e]nforceable as a practical matter' will be achieved if a requirement 
is both legally and practically enforceable.'' Among several other 
provisions, the 2002 final rule established provisions for Plantwide 
Applicability Limitations (PALs).\3\
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    \1\ The January 25, 1995 OAQPS memo was predicated on a view 
that federal enforceability is an essential element in establishing 
potential to emit limits. A court decision in the National Mining 
Association (NMA) v. EPA, 59 F.3d 1351, 1363-1365 (D.C. Cir. 1995) 
remanded the Federal enforceability provision. Consistent with this 
decision, EPA's longstanding policy allows for any physical or 
operational limitation on the capacity of the stationary source to 
emit a pollutant to be treated as part of the source's design if the 
limitation or the effect it would have on emissions is, first, 
either federally enforceable or legally enforceable by a state or 
local permitting authority and, second, practicably enforceable. See 
December 20, 1999, memorandum titled ``Third Extension of January 
25, 1995 Potential to Emit Transition Policy.'' Available in the 
docket for this rulemaking.
    \2\ PSD and NSR: Baseline Emissions Determination, Actual-to-
Future-Actual Methodology, Plantwide Applicability Limitations, 
Clean Unit, Pollution Control Projects. 67 FR 80190-80191 (December 
31, 2002).
    \3\ The PAL regulations were upheld by the Court in New York v. 
EPA, 413 F.3d 3, 22 (D.C. Cir. 2005).
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    To make a PAL enforceable as a practical matter, the EPA 
regulations require a source to conduct monitoring, recordkeeping and 
reporting of the actual emissions of a PAL pollutant on a 12-month 
rolling total basis. A PAL monitoring system must employ one or more of 
four general approaches meeting minimum requirements specified in the 
regulations. These include mass balance calculations for activities 
using coatings or solvents, CEMS, continuous parameter monitoring 
systems (CPMS) or predictive emissions monitoring systems (PEMS), and 
emission factors. 40 CFR 52.21(aa)(12)(i)(b), (aa)(12)(ii). The 
regulations also provide for alternative monitoring approaches that are 
approved by the reviewing authority. 40 CFR 52.21(aa)(12)(i)(c). 
Connecticut's RCSA Sections 33a and 33b contain monitoring and 
recordkeeping requirements that are substantially consistent with those 
in the EPA PAL regulations, supporting the conclusion that the limits 
in Connecticut's RCSA Sections 33a and 33b are enforceable as a 
practical matter.
    As stated above, EPA's January 25, OAQPS PTE memorandum and EPA's 
2002 final rule provide specific criteria for practical enforceability 
to be achieved. Connecticut's rules include requirements that meet 
these criteria. Specifically, 33a(d) and 33b(d) specify technically-
accurate emission limitations that apply premises-wide on a 12-month 
rolling annual basis. Sections 33a(d) and 33b(d) specify a preferential 
hierarchy for determining compliance with the emission limitations, as 
well as monitoring, reporting and recordkeeping. In addition, Sections 
33a(g) and 33b(h) require a notification to the permitting

[[Page 13940]]

authority for sources that elect coverage under the rules. Sections 
33a(b) and 33b(c) include duty to comply provisions, as well as a 
required certification statement in 33a(c) and 33b(k) to be submitted 
that the information submitted is true, accurate and complete. These 
provisions require the certifier to acknowledge that any false 
statements may be punishable as a criminal offense under Connecticut's 
statutes. In addition, Sections 33a(j) and 33b(k) provide that nothing 
in these sections precludes the Commissioner from requiring a source to 
obtain a title V operating permit. Lastly, Sections 33a(f)(2)(A) and 
33b(g)(3)(A) require the owner or operator to determine the cause of 
any emission limitation exceedance, correct such exceedance, mitigate 
its results, and prevent any further exceedance.
    In addition to providing practical enforceability criteria, the 
January 25, 1995 OAQPS PTE memo indicates that one approach to 
establishing appropriately enforceable limitations is by general rules 
creating enforceable restrictions at one time for many sources. The 
memo discusses a California model rule developed in consultation with 
EPA as an example of such an approach. The California model rule is 
designed to place smaller sources under annual emissions limits which 
restrict their ``potential to emit'' and thus their exposure to ``major 
source'' requirements of the Clean Air Act. The California model rule 
ensures compliance with the annual limit through a series of 
recordkeeping and reporting requirements. These requirements are 
tapered to reduce burdens as source size (as it relates to emissions) 
decreases. The California model rule provides a hierarchy of data for 
sources to calculate actual emissions for every consecutive 12-month 
period.
    Connecticut's RCSA Sections 33a and 33b are consistent with the 
approach taken in the California model rule, cited approvingly as an 
example by EPA. The California model rule and Connecticut's rules 
require a detailed hierarchy for sources to calculate emissions. 
Specifically, Connecticut's Section 22a-174-33a(d)(4) requires:

    (A) If data are available from CEM equipment, such data shall be 
used to determine the rate of emissions. Only CEM installed, 
operated, and certified in accordance with a permit or order, 
regulation issued or administered by the Commissioner or the 
Administrator, or a Commissioner approved voluntarily installed CEM 
may be used to satisfy the requirements of this subdivision;
    (B) If the data in subparagraph (A) of this subdivision are 
unavailable but stack testing data are available, such stack testing 
data shall be used to determine the rate of emissions, provided such 
testing was conducted in accordance with protocols approved in 
writing by the Commissioner or the Administrator in advance of 
testing and a representative of the Commissioner or the 
Administrator was provided the opportunity to witness such testing;
    (C) If the data in subparagraphs (A) and (B) of this subdivision 
are unavailable, the rate of emissions shall be calculated using 
data supplied by the manufacturer of the subject emission unit or 
units, which data were derived from EPA approved emissions testing 
of such unit performed by or for the manufacturer;
    (D) If the data in subparagraphs (A), (B) and (C) of this 
subdivision are unavailable, the rate of emissions shall be 
calculated using data derived from an analysis of pertinent material 
balances;
    (E) If the data in subparagraphs (A), (B), (C) and (D) of this 
subdivision are unavailable, the rate of emissions shall be 
calculated using the data or emissions estimation technique from the 
following EPA publications that results in the highest rate of 
emissions:
    (i) Compilation of Air Pollutant Emission Factors (AP-42),
    (ii) AIRS Facility Subsystem Emission Factors, or
    (iii) The Emission Inventory Improvement Program; and
    (F) If the data in subparagraphs (A), (B), (C), (D) and (E) of 
this subdivision are not available, the emission rate shall be 
calculated using another source of emissions data that is approved 
by the Commissioner and the Administrator. Such approval shall be 
obtained prior to operating in accordance with this section.

    Connecticut's rules include a preferential hierarchy to use the 
best data to calculate actual emissions when available. Actual 
emissions are required to be calculated for the premises for each and 
every consecutive 12-month period. Connecticut set the emissions 
limitation in Section 33a at 50% of the major source threshold to 
create a sufficient buffer to account for variability that may exist in 
calculating emissions using the methods allowed in the preferential 
hierarchy. Section 33b sets the premises wide limit to below 80% of the 
major source threshold for certain source categories and requires 
additional monitoring and recordkeeping for these source categories.
    In addition to the preferential hierarchy, Connecticut's RCSA 
Sections 33a and 33b also require detailed records and emissions 
calculations including a log of:

    (i) The total amount of fuels, solvents, coatings, raw 
materials, or other such material, used by each emission unit during 
each month,
    (ii) An identification of such fuels, solvents, coatings, raw 
materials, or other such material used, by each emission unit during 
each month,
    (iii) The actual operating hours of each emission unit during 
each month, as necessary to calculate emissions,
    (iv) Any other documentation the Commissioner deems necessary to 
reliably calculate the emission of air pollutants regulated under 
this section, and
    (v) All purchase orders, invoices, Material Safety Data Sheets, 
test results, certifications or other documents necessary to verify 
information and calculations in the monthly log.

    In addition, Connecticut's RCSA 33a and 33b require sources to 
maintain a log of annual actual emissions of each regulated air 
pollutant emitted from the premises, including a detailed description 
of the methodology the owner or operator used to calculate such 
emissions and the basis thereof.
    Connecticut's 33a and 33b also require the facility to submit 
annual compliance certifications. Section 33b, which limits sources to 
up to, but not more than, 80% of the major title v operating source 
threshold, requires sources with actual emissions >50% of the major 
source threshold to report emissions for each and every 12-month 
period. Sections 33a and 33b further allow DEEP to request any 
additional information in writing to verify actual emissions. (See RCSA 
22a-174-33a(f) and 33b(g)) Connecticut's rules also require sources to 
maintain records of any other documentation the Commissioner deems 
necessary to reliably calculate the emission of air pollutants 
regulated. (See RCSA 22a-174-33a(e)(1)(B)(iv) and 33b(f)(1)(B)(iv))
    In addition to this regulatory oversight of sources by the State, 
in a letter dated January 12, 2022, Connecticut provided that:

    DEEP has a robust federally enforceable minor source new source 
review (NSR) permit program that governs operations of individual 
pieces of equipment. Section 22a-174-33a and Section 22a-174-33b do 
not shield pieces of equipment from Connecticut's minor source NSR 
program. Consequently, pieces of equipment subject to minor source 
NSR at facilities operating under RCSA Section 22a-174-33a or 
Section 22a-174-33b would be subject to Best Achievable Control 
Technology, ambient air quality impact analysis, monitoring, record 
keeping and reporting to assure compliance with individual pollutant 
limits contained in the permits. Permits for many pieces of 
equipment require periodic emissions testing and/or continuous 
emission monitoring systems (CEMS) to assure compliance with permit 
limits. The permits contain limits on allowable materials, material 
composition and material throughput and include monitoring, record 
keeping and reporting to assure that sources are operating as 
expected. Where applicable, many permits limit startup and shutdown 
emissions and require

[[Page 13941]]

monitoring and record keeping of startup and shutdown emissions to 
assure compliance with annual emissions limits.
    Finally, concerning DEEP's compliance oversight of sources 
operating under RCSA sections 22a-174-33a and -33b, DEEP offers the 
following information. . . . DEEP's five-year inspection frequency 
for RCSA section 22a-174-33b sources is consistent with the 
frequency stipulated in EPA's CAA CMS policy for synthetic minor 80 
percent (SM-80) sources. Note that under EPA's CAA CMS, an SM-80 
source is one with a premises-wide potential to emit (including any 
federally or legally and practicably enforceable physical or 
operational limitations on such source's capacity) greater than or 
equal to 80% and less than 100% of the major source thresholds, 
whereas an RCSA section 22a-174-33b source is limited to premises-
wide emissions less than 80% of the major source thresholds. See 
EPA's CAA Stationary Source CMS, October 2016, section IV [available 
in the docket for this rulemaking]. Since EPA's CMS does not 
establish a minimum inspection frequency for true minor sources or 
synthetic minor sources that do not qualify as SM-80s, the five-year 
FCE [full compliance evaluation] frequency to which DEEP has 
committed for the RCSA section 22a-174-33b source universe is more 
stringent than required by EPA's CMS.
    Sources operating under RCSA section 22a-174-33a are subject to 
inspection at DEEP's discretion. Such inspections may take the form 
of an on-site FCE or an off-site partial compliance evaluation 
(e.g., the issuance of an information request under RCSA section 
22a-174-4 and the subsequent inspection of responsive records).
    In inspecting synthetic minor sources operating under RCSA 
sections 22a-174-33a and -33b, DEEP ensures proper calculation of 
facility-wide emissions, including the appropriateness of the 
selected emission factors, pursuant to the hierarchy of emission 
calculation methodologies established in subsection (d)(4) of either 
regulation. This approach is consistent with DEEP's handling of 
sources previously registered under DEEP's General Permit to Limit 
the Potential to Emit (GPLPE). In inspecting sources that calculate 
emissions using CEMS data, DEEP ensures that such CEMS meet 
applicable performance specifications, quality assurance (QA) 
requirements, and operational requirements by (i) reviewing relative 
accuracy test audit (RATA) protocols and results and auditing such 
test programs as resources allow; (ii) reviewing quarterly excess 
emission and downtime reports; (iii) verifying that the required QA 
activities are completed and passed; and (iv) during on-site FCEs, 
conducting a physical inspection of the CEMS. In inspecting sources 
that calculate emissions using stack test data, DEEP ensures the 
validity of stack testing--including the utilization of appropriate 
test methods, conformance with such methods, and the proper 
reduction and accuracy of the test results--by reviewing all stack 
test protocols and results and auditing such test programs as 
resources allow. Furthermore, DEEP verifies that testing is 
conducted under the most challenging representative operating 
conditions. See, e.g., EPA's CAA National Stack Testing Guidance, 
April 2009, section 5 and DEEP's Source Emission Monitoring Test 
Guidelines, Version 2.0, April 2019, section 8 [available in the 
docket for this rulemaking].
    Furthermore, consistent with its handling of GPLPE reports, DEEP 
reviews all reports submitted in accordance with RCSA sections 22a-
174-33a and -33b upon their submission, including annual compliance 
certifications; emission exceedance reports; and, for sources 
operating under RCSA section 22a-174-33b, annual emission reports. 
In reviewing emission reports, DEEP ensures proper calculation of 
facility-wide emissions, including the appropriateness of the 
selected emission factors, pursuant to the hierarchy of emission 
calculation methodologies established in the regulations.\4\
---------------------------------------------------------------------------

    \4\ EPA notes that when Connecticut DEEP refers to the GPLPE, 
they are referring to a prior general permit designed to limit air 
pollutant emissions from major stationary sources to below major 
source thresholds by including legally and practicably enforceable 
permit restrictions on potential and actual emissions. Connecticut 
adopted new RCSA sections 22a-174-33a and 22a-174-33b as a 
replacement program for the GPLPE. On April 24, 2017, EPA approved 
Connecticut's GPLPE issued on November 9, 2015. See 82 FR 18868.

    In summary, Connecticut's regulatory scheme includes significant 
oversight; emission limitations containing a sufficient buffer below 
the major source thresholds to account for variability that may exist 
in calculating emissions; the requirement to use methods to calculate 
emissions from a preferential hierarchy; and requirements for 
monitoring, reporting and recordkeeping. The overall regulatory scheme 
is based on a model rule contained in EPA guidance, California's model 
rule, and establishes a program that EPA finds legally and practicably 
enforceable to limit a sources potential to emit.
    While EPA provides a general response to the adverse comment above, 
for purposes of clarity, below we have broken down the comment into its 
specific parts and provide additional responses for specific issues 
raised within the comment.
    Comment 5a: The commenter stated that while CEMS are a good method, 
Section (d)(4)(A) does not require data substitution or gap filling 
when CEMS data for certain time periods are not available, and that 
potential to emit and actual emissions which trigger title V and RACT 
applicability don't allow for ignoring certain periods of emissions. 
The commenter is concerned about periods of startup and shutdown when 
CEMS may not be operating or other times when CEMS data is unavailable. 
The commenter states that CEMS are often not required to gather data 
during periods of startup and shutdown even though some emission 
sources, such as combustion devices, can have substantially higher 
emissions during those periods and cites generally to Weiler v. Chatham 
Forest Products, 392 F.3d 532, 535 (2nd Cir. 2004). The commenter also 
stated that CEMS have downtime, both planned downtime to do testing and 
unplanned downtime, and because (d)(4)(A) does not address this, it 
would be arbitrary and capricious for EPA to approve this.
    Response: EPA disagrees with the commenter and finds that the 
portions of Connecticut's rules that allow for calculating premises-
wide emissions using CEMS data sufficiently accounts for determining 
actual emissions over a 12-month rolling period. Only CEMS installed, 
operated, and certified in accordance with a permit, order, or 
regulation issued or administered by the Commissioner or EPA, or a 
Commissioner approved voluntarily installed CEMS may be used to 
calculate emissions. (See RCSA 33a(d)(4)(A) and 33b(d)(4)A)) In 
addition, the regulations specify when data from CEMS are not 
available, the next method in the hierarchy, if available, is to be 
used to calculate emissions, so the regulations do not allow data gaps 
in calculating actual emissions. Connecticut's CEMS rules do not allow 
for the exclusion of startup and shutdown emissions. Connecticut's CEMS 
regulations also specify quality assurance requirements for CEMS, 
minimum CEMS data availability, and prohibit shutdown of monitoring 
equipment. (See RCSA 22a-174-4(c)(4)-(5), and 22a-174-7) Connecticut's 
regulations specify that CEMS data shall be available no less than 90% 
of the total operating hours of a source per calendar quarter, except 
for sources operated less than 336 hours and approved by the 
Commissioner. In addition, Connecticut's rule is written to provide a 
sufficient buffer below the major source threshold by setting the 
premises-wide limit to below 50% of the major source threshold or 
alternatively, setting the premises-wide limit in Connecticut's 33b to 
below 80% of the major source threshold for certain source categories 
with additional required monitoring and recordkeeping. Connecticut's 
requirements for minimum CEMS data availability ensure that sufficient 
data is being collected for calculating emissions, which combined with 
the buffer below the major source thresholds, ensure that sources' 
emissions stay below the major source thresholds. In light of the 
overall regulatory scheme, the PTE limits in Connecticut's regulation 
are not

[[Page 13942]]

rendered practicably unenforceable because of the use of CEMS.
    Comment 5b: The commenter was concerned that stack tests are not 
performed during startups or shutdowns. The commenter stated that by 
using stack test data to calculate ``actual'' emissions on an annual 
basis, Section (d)(4)(B) ignores an important part of the problem, that 
is actual emissions during periods of startup, shutdown, process 
malfunctions, control equipment malfunctions or operations at different 
operating periods that are not startup and shutdown. The commenter 
asserted that the problem isn't limited to startup or shutdown because 
the fact that a source emitted at a certain rate during a stack test 
does not prove that a source emits at that same rate every other hour 
that it operates. The commenter asserted that this flaw is further 
compounded by the lack of a requirement for the frequency of stack 
testing. The commented asserted that a stack test performed 20 years 
ago, for example, provides no reliable data on current emissions.
    Response: Connecticut's 33a(d)(4)(B) and 33b(d)(4)(B) only allow 
stack tests if such testing is conducted in accordance with protocols 
approved in writing by the Commissioner or the Administrator in advance 
of testing and when a representative of the Commissioner or the 
Administrator has been provided the opportunity to witness such 
testing. Should parametric monitoring, specifically required by RCSA 
22a-174-33b, indicate that operations are outside of the ranges 
occurring during the most recent test, or for any other reason, 
Connecticut has the authority to mandate emissions testing to assure 
compliance with applicable limits under RCSA 22a-174-5(e)(2). In 
addition, Connecticut's rule is written to provide a sufficient buffer 
below the major source threshold by setting the premises wide limit to 
below 50% of the major source threshold or alternatively, setting the 
premises wide limit in Connecticut's 33b to below 80% of the major 
source threshold for certain source categories with additional required 
monitoring and recordkeeping. Although stack tests are not conducted 
during startup or shutdown, stack tests are required to be conducted 
under conditions representative of a source's operations and that would 
be reviewed during the required approval of the test protocol. Stack 
test data, combined with the buffer below the major source thresholds, 
ensure that sufficient data is being collected to ensure that sources' 
emissions stay below the major source thresholds. In light of the 
overall regulatory scheme, the PTE limits in Connecticut's regulations 
are not rendered practicably unenforceable because of the allowance for 
stack testing.
    Comment 5c: Regarding manufacturers' data to calculate emissions, 
the commenter is concerned that the manufactures' testing may not 
provide reliable data on emissions from the source in question if the 
source that is going to use this rule is defective in some way or not 
properly installed. The commenter is also concerned about the 
conditions of the source matching the conditions of the manufacturer's 
test. The commenter states that if the manufacturer did its testing in 
a high-altitude desert, that could create radically different 
conditions from sea level winter conditions that a source in 
Connecticut faces. This difference in altitude and weather can result 
in very different combustion and evaporation conditions which change 
emissions.
    Response: Connecticut's 33a(d)(4)(C) and 33b(d)(4)(C) only allow 
the rate of emissions to be calculated using data supplied by the 
manufacturer of the subject emission unit or units, when such data were 
derived from EPA approved emissions testing of such unit performed by 
or for the manufacturer. Should parametric monitoring, specifically 
required by RCSA 22a-174-33b, indicate that operations are outside of 
the ranges occurring during the most recent test, or for any other 
reason, Connecticut has the authority to mandate emissions testing to 
assure compliance with applicable limits under RCSA 22a-174-5(e)(2). 
Regarding the commenter's concern that the source may be defective or 
not installed properly, Connecticut's RCSA 22a-174-7(b) prohibits the 
deliberate shut down of air pollution control equipment or monitoring 
equipment except to perform maintenance as specified. In addition, 
Connecticut has committed to conduct inspections every 5 years for 
sources covered by RCSA 22a-174-33b, and sources covered by RCSA 22a-
174-33a are subject to inspection at DEEP's discretion. Lastly, 
Connecticut's rule is written to provide a sufficient buffer below the 
major source threshold by setting the premises wide limit to below 50% 
of the major source threshold or alternatively, setting the premises 
wide limit in Connecticut's 33b to below 80% of the major source 
threshold for certain source categories with additional required 
monitoring and recordkeeping. Manufacturers' test data, combined with 
Connecticut's oversight and the buffer below the major source 
thresholds, ensures that sufficient data is being collected to ensure 
that sources stay below the major source thresholds. In light of the 
overall regulatory scheme, the PTE limits in Connecticut's regulations 
are not rendered practicably unenforceable by the allowance, under 
certain circumstances, of the use of manufacturers' data to calculate 
emissions.
    Comment 5d: The commenter is concerned that 33a(d)(4)(D) and 
33b(d)(4)(D), a requirement in the hierarchy to use pertinent material 
balances, is not rationally related to actual emissions. The commenter 
questioned how a pertinent material balance would account for thermal 
NOX emissions, that is NOX that is formed in 
combustion processes because our air is 78% nitrogen, regardless of the 
composition of the fuel. The commenter stated that thermal NOx 
formation is greatly influenced by temperature in combustion processes 
but (d)(4)(D) does not require any parametric monitoring, much less 
restrictions, on operating temperature.
    Response: EPA disagrees that a source would be required to use 
material balances to calculate thermal NOX formation. 
Sections 33a(d)(4)(E) and 33b(d)(4)(E) require that if pertinent 
material balance data is not available, for example, to calculate 
thermal NOX emissions, and other preferential methods in the 
hierarchy were not available, sources should use the data or emissions 
estimation technique from the following EPA publications that results 
in the highest rate of emissions: (i) Compilation of Air Pollutant 
Emission Factors (AP-42), (ii) AIRS Facility Subsystem Emission 
Factors, or (iii) The Emission Inventory Improvement Program (EIIP). In 
addition, emissions can be calculated for a premise using a combination 
of methods in the hierarchy depending on the operations. That is 
because the hierarchy does not require the exclusive use of one method 
for calculating emissions if data in the hierarchy is available for 
certain operations and not for others. Material balances, combined with 
the buffer below the major source thresholds, ensures that sufficient 
data is being collected to ensure that sources stay below the major 
source thresholds. In light of the overall regulatory scheme, the PTE 
limits in Connecticut's regulations are not rendered practicably 
unenforceable by the allowance, under certain circumstances, of the use 
of material balances to calculate emissions.
    Comment 5e: The commenter is concerned that 33a(d)(4)(E) and 
33b(d)(4)(E) are not rationally related to actual emissions. The 
commenter points to the introduction section of AP-42, Compilation of 
Air Pollutant Emission Factors which provides ``Average

[[Page 13943]]

emissions differ significantly from source to source and, therefore, 
emission factors frequently may not provide adequate estimates of the 
average emissions for a specific source. The extent of between-source 
variability that exists, even among similar individual sources, can be 
large depending on process, control system, and pollutant. Although the 
causes of this variability are considered in emission factor 
development, this type of information is seldom included in emission 
test reports used to develop AP-42 factors.'' As a result, some 
emission factors are derived from tests that may vary by an order of 
magnitude or more. The commenter states that EPA's position has been 
that AP-42 should not be used for ensuring compliance with synthetic 
minor limits. The commenter states that AP-42 clearly states that it is 
used for ``estimating emissions'' but a synthetic minor limit is not an 
estimate. The commenter states that actual and potential to emit 
emissions have to be below the applicable threshold, and that actual 
emissions and an estimate of emissions are two separate things. The 
commenter is also concerned that AP-42 emission factors come with 
ratings. A ``D'' rating is below average and an ``E'' rating is Poor. 
The commenter states that Section (d)(4)(E) allows the use of even 
emission factors which EPA itself describes as ``Poor'', and that it is 
arbitrary for EPA to allow the use of ``Poor'' ``estimates'' to provide 
actual emissions.
    Response: Sections 33a(d)(4)(E) and 33b(d)(4)(E) require that if 
other preferential methods in the hierarchy are not available, sources 
should use the data or emissions estimation technique from the 
following EPA publications that results in the highest rate of 
emissions: (i) Compilation of Air Pollutant Emission Factors (AP-42), 
(ii) AIRS Facility Subsystem Emission Factors, or (iii) The Emission 
Inventory Improvement Program (EIIP). In calculating emissions using 
emission factors when other data are not available, Connecticut 
conservatively requires the highest rate of emissions from these 
publications to be used. The calculation of emissions and assurance of 
compliance with the limits is not reliant on this alone but also on 
parametric monitoring, which is explicitly required by RCSA 22a-174-
33b. Should parametric monitoring indicate that operations are outside 
of the ranges occurring during the most recent test, or for any other 
reason, Connecticut has the authority to mandate emissions testing to 
assure compliance with applicable limits under RCSA 22a-174-5(e)(2). As 
noted above, emissions can be calculated for a premise using a 
combination of methods in the hierarchy depending on the operations, 
because the hierarchy does not require the exclusive use of one method 
if data in the hierarchy is available for certain operations and not 
for others.
    EPA acknowledges that in the AP-42 Introduction document we state 
that use of these factors as source-specific permit limits and/or as 
emission regulation compliance determinations is not recommended by 
EPA. However, we also state that emission factors are frequently the 
best or only method available for estimating emissions, despite their 
limitations. And we further provide that if representative source-
specific data cannot be obtained, emissions information from equipment 
vendors, particularly emission performance guarantees or actual test 
data from similar equipment, is a better source of information for 
permitting decisions than an AP-42 emission factor. When such 
information is not available, use of AP-42 emission factors may be 
necessary as a last resort. Sources that reach this level of the data 
hierarchy in Connecticut's rules would typically be the smallest 
sources of emissions and it would be unreasonably costly to require 
such small sources to install a CEMS or conduct a stack test to 
calculate emissions for purposes of demonstrating emissions remain 
below the major source thresholds.\5\
---------------------------------------------------------------------------

    \5\ See AP-42, Introduction at 3. ``Where the risks of using a 
poor estimate are low, and the costs of more extensive methods are 
unattractive, then less expensive estimation methods such as 
emission factors and emission models may be both satisfactory and 
appropriate.''
---------------------------------------------------------------------------

    In addition, Connecticut's rule is written to provide a sufficient 
buffer below the major source threshold by setting the premises wide 
limit in Connecticut's 33a to below 50% of the major source threshold, 
or alternatively, setting the premises wide limit in Connecticut's 33b 
to below 80% of the major source threshold for certain source 
categories with additional required monitoring and recordkeeping. In 
light of all the material provisions of Connecticut's regulatory scheme 
including the buffer below the major source thresholds, the possibility 
of the use of AP-42 emissions factors when other data in the hierarchy 
are not available does not render the PTE limits practicably 
unenforceable.

III. Final Action

    EPA is approving Connecticut's RCSA section 22a-174-33a, Limit on 
Premises-wide Actual Emissions Below 50% of Title V Thresholds, 
effective September 24, 2020, and RCSA section 22a-174-33b, Limit on 
Premises-wide Actual Emissions Below 80% of Title V Thresholds, 
effective September 24, 2020 (excluding the following provision: RCSA 
22a-174-33b(d)(6)) as a revision to the Connecticut SIP with respect to 
criteria pollutants and is separately approving the regulations under 
section 112(l) of the Act with respect to HAPs. EPA is approving 
Connecticut's request in accordance with the requirements of sections 
110 and 112 of the CAA.

IV. Incorporation by Reference

    In this rule, the EPA is finalizing regulatory text that includes 
incorporation by reference. In accordance with requirements of 1 CFR 
51.5, the EPA is finalizing the incorporation by reference of the 
Connecticut Regulations described in the amendments to 40 CFR part 52 
set forth below. The EPA has made, and will continue to make, these 
documents generally available through https://www.regulations.gov and 
at the EPA Region 1 Office (please contact the person identified in the 
FOR FURTHER INFORMATION CONTACT section of this preamble for more 
information).

V. Statutory and Executive Order Reviews

    Under the Clean Air Act, the Administrator is required to approve a 
SIP submission that complies with the provisions of the Act and 
applicable Federal regulations. 42 U.S.C. 7410(k); 40 CFR 52.02(a). 
Thus, in reviewing SIP submissions, EPA's role is to approve state 
choices, provided that they meet the criteria of the Clean Air Act. 
Accordingly, this action merely approves state law as meeting Federal 
requirements and does not impose additional requirements beyond those 
imposed by state law. For that reason, this action:
     Is not a significant regulatory action subject to review 
by the Office of Management and Budget under Executive Orders 12866 (58 
FR 51735, October 4, 1993) and 13563 (76 FR 3821, January 21, 2011);
     Does not impose an information collection burden under the 
provisions of the Paperwork Reduction Act (44 U.S.C. 3501 et seq.);
     Is certified as not having a significant economic impact 
on a substantial number of small entities under the Regulatory 
Flexibility Act (5 U.S.C. 601 et seq.);
     Does not contain any unfunded mandate or significantly or 
uniquely

[[Page 13944]]

affect small governments, as described in the Unfunded Mandates Reform 
Act of 1995 (Pub. L. 104-4);
     Does not have federalism implications as specified in 
Executive Order 13132 (64 FR 43255, August 10, 1999);
     Is not an economically significant regulatory action based 
on health or safety risks subject to Executive Order 13045 (62 FR 
19885, April 23, 1997);
     Is not a significant regulatory action subject to 
Executive Order 13211 (66 FR 28355, May 22, 2001);
     Is not subject to requirements of Section 12(d) of the 
National Technology Transfer and Advancement Act of 1995 (15 U.S.C. 272 
note) because application of those requirements would be inconsistent 
with the Clean Air Act; and
     Does not provide EPA with the discretionary authority to 
address, as appropriate, disproportionate human health or environmental 
effects, using practicable and legally permissible methods, under 
Executive Order 12898 (59 FR 7629, February 16, 1994).

In addition, the SIP is not approved to apply on any Indian reservation 
land or in any other area where EPA or an Indian tribe has demonstrated 
that a tribe has jurisdiction. In those areas of Indian country, the 
rule does not have tribal implications and will not impose substantial 
direct costs on tribal governments or preempt tribal law as specified 
by Executive Order 13175 (65 FR 67249, November 9, 2000).
    The Congressional Review Act, 5 U.S.C. 801 et seq., as added by the 
Small Business Regulatory Enforcement Fairness Act of 1996, generally 
provides that before a rule may take effect, the agency promulgating 
the rule must submit a rule report, which includes a copy of the rule, 
to each House of the Congress and to the Comptroller General of the 
United States. EPA will submit a report containing this action and 
other required information to the U.S. Senate, the U.S. House of 
Representatives, and the Comptroller General of the United States prior 
to publication of the rule in the Federal Register. A major rule cannot 
take effect until 60 days after it is published in the Federal 
Register. This action is not a ``major rule'' as defined by 5 U.S.C. 
804(2).
    Under section 307(b)(1) of the Clean Air Act, petitions for 
judicial review of this action must be filed in the United States Court 
of Appeals for the appropriate circuit by May 10, 2022. Filing a 
petition for reconsideration by the Administrator of this final rule 
does not affect the finality of this action for the purposes of 
judicial review nor does it extend the time within which a petition for 
judicial review may be filed and shall not postpone the effectiveness 
of such rule or action. This action may not be challenged later in 
proceedings to enforce its requirements. (See section 307(b)(2))

List of Subjects in 40 CFR Part 52

    Environmental protection, Air pollution control, Carbon monoxide, 
Incorporation by reference, Intergovernmental relations, Lead, Nitrogen 
dioxide, Ozone, Particulate matter, Reporting and recordkeeping 
requirements, Sulfur oxides, Volatile organic compounds.

    Dated: March 4, 2022.
David Cash,
Regional Administrator, EPA Region 1.

    Part 52 of chapter I, title 40 of the Code of Federal Regulations 
is amended as follows:

PART 52--APPROVAL AND PROMULGATION OF IMPLEMENTATION PLANS

0
1. The authority citation for part 52 continues to read as follows:

    Authority: 42 U.S.C. 7401 et seq.

Subpart H--Connecticut

0
2. Section 52.370 is amended by adding paragraph (c)(127) to read as 
follows:

 Sec.  52.370   Identification of plan.

* * * * *
    (c) * * *
    (127) Revisions to the State Implementation Plan submitted by the 
Connecticut Department of Energy and Environmental Protection on 
October 26, 2020, supplemented on January 12, 2022.
    (i) Incorporation by reference. (A) Regulations of Connecticut 
State Agencies section 22a-174-33a, Limit on Premises-wide Actual 
Emissions Below 50% of Title V Thresholds, effective September 24, 
2002.
    (B) Regulations of Connecticut State Agencies section 22a-174-33b, 
Limit on Premises-wide Actual Emissions Below 80% of Title V 
Thresholds, effective September 24, 2020, excluding section (d)(6).
    (ii) Additional materials. (A) Letter from the Connecticut 
Department of Energy and Environmental Protection dated October 26, 
2020, submitting a revision to the Connecticut State Implementation 
Plan.
    (B) Letter from the Connecticut Department of Energy and 
Environmental Protection dated January 12, 2022, withdrawing 
Regulations of Connecticut State Agencies section 22a-174-33b(d)(6) 
from its SIP submittal.

0
3. Section 52.385 is amended in Table 52.385 by adding state citations 
for 22a-174-33a and 22a-174-33b in alphanumerical order to read as 
follows:

Sec.  52.385   EPA-approved Connecticut regulations.

* * * * *

                                     Table 52.385--EPA-Approved Regulations
----------------------------------------------------------------------------------------------------------------
                                                  Dates
                                       --------------------------
 Connecticut  State     Title/subject       Date         Date     Federal Register    Section       Comments/
      citation                           adopted by  approved by       citation       52.370       description
                                           State         EPA
----------------------------------------------------------------------------------------------------------------
 
                                                  * * * * * * *
22a-174-33a.........  Limit on            9/24/2020    3/11/2022  [Insert Federal      (c)127   ................
                       Premises-wide                               Register
                       Actual                                      citation].
                       Emissions Below
                       50% of Title V
                       Thresholds.
22a-174-33b.........  Limit on            9/24/2020    3/11/2022  [Insert Federal      (c)127   Approved with
                       Premises-wide                               Register                      the exception
                       Actual                                      citation].                    of section
                       Emissions Below                                                           (d)(6) which
                       80% of Title V                                                            Connecticut
                       Thresholds.                                                               withdrew from
                                                                                                 its SIP
                                                                                                 submittal.
 
                                                  * * * * * * *
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[[Page 13945]]

[FR Doc. 2022-05042 Filed 3-10-22; 8:45 am]
BILLING CODE 6560-50-P