[Federal Register Volume 87, Number 195 (Tuesday, October 11, 2022)]
[Rules and Regulations]
[Pages 61249-61259]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2022-21815]


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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 52

[EPA-R08-OAR-2019-0140; EPA-HQ-OAR-2021-0663; FRL-9782-02-R8]


Air Plan Approval; Colorado; Addressing Remanded Portions of the 
Previously Approved Infrastructure Requirements for the 2015 Ozone 
National Ambient Air Quality Standards

AGENCY: Environmental Protection Agency (EPA).

ACTION: Final rule.

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SUMMARY: On January 5, 2021, the United States Court of Appeals for the 
Tenth Circuit granted the Environmental Protection Agency's (EPA) 
motion for a voluntary remand without vacatur of two parts of an EPA 
2020 final rule approving Colorado's infrastructure state 
implementation plan (SIP) submission for the 2015 8-hour ozone national 
ambient air quality standards (NAAQS) (2020 final rule). In this 
document, EPA is taking final action to approve those two remanded 
parts of the 2020 final rule. First, EPA is finalizing our conclusion 
that Colorado's infrastructure SIP submission meets the State's good 
neighbor obligations under Clean Air Act (CAA) section 
110(a)(2)(D)(i)(I). Lastly, EPA is also finalizing our conclusion that 
Colorado's infrastructure SIP submission provided ``necessary 
assurances'' of the State's authority to regulate agricultural sources 
under CAA section 110(a)(2)(E)(i). EPA is taking this action pursuant 
to the CAA.

DATES: This rule is effective on November 10, 2022.

ADDRESSES: EPA has established two dockets for this action. The 
regional docket, Docket ID No. EPA-R08-OAR-2019-0140 contains 
information specific to Colorado, including this final rule document, 
and the notice of proposed rulemaking. Docket ID No. EPA-HQ-OAR-2021-
0663 contains additional modeling files, emissions inventory files, 
technical support documents, and other relevant supporting 
documentation regarding interstate transport of emissions for the 2015 
8-hour ozone NAAQS which were used to support EPA's proposed approval. 
All documents in the docket are listed on the www.regulations.gov 
website. Although listed in the docket, some information may not be 
publicly available, e.g., 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 through www.regulations.gov, or please contact the person 
identified in the FOR FURTHER INFORMATION CONTACT section for 
additional availability information.

FOR FURTHER INFORMATION CONTACT: Amrita Singh, Air and Radiation 
Division, EPA, Region 8, Mailcode 8ARD-IO, 1595 Wynkoop Street, Denver, 
Colorado, 80202-1129, telephone number: (303) 312-6103, email address: 
[email protected]; or Ellen Schmitt, telephone number: (303) 312-
6728, email address: [email protected].

SUPPLEMENTARY INFORMATION: Throughout this document ``we,'' ``us,'' and 
``our'' means EPA.

I. Background

    On May 6, 2022 (88 FR 27050), EPA published a document in the 
Federal Register proposing approval of the two remanded parts of EPA's 
2020 final rule.\1\ EPA's May 2022 proposed approval addressed (1) the 
adequacy of Colorado's infrastructure submission for the 2015 8-hour 
ozone NAAQS under the CAA's ``good neighbor provision,'' \2\ which 
generally requires SIPs to contain adequate provisions to prohibit in-
state emissions from significantly contributing to nonattainment or 
interfering with the maintenance in another state, and (2) the adequacy 
of Colorado's infrastructure submission for the 2015 8-hour ozone NAAQS 
under CAA section 110(a)(2)(E)(i), particularly with respect to 
Colorado's authority to regulate agricultural sources.\3\ The rationale 
for EPA's proposed action is included in the May 6, 2022 proposal and 
will not be repeated here.
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    \1\ 2020 final rule. Approval and Promulgation of State 
Implementation Plan Revisions; Infrastructure Requirements for the 
2015 Ozone National Ambient Air Quality Standards; Colorado and 
North Dakota, 85 FR 20169 (April 10, 2020).
    \2\ 42 U.S.C. 7410(a)(2)(D)(i)(I).
    \3\ 42 U.S.C. 7410(a)(2)(E)(i).
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II. Response to Comments

    EPA received comments on the proposed rule from an individual 
citizen and the Center for Biological Diversity (the Center). We 
summarize and respond to the comments below.

Individual Citizen

    Comment: The commenter initially states that ``concerns regarding 
the 2015 Ozone NAAQS infrastructure requirements highlight potential 
problems regarding both the `Good Neighbor Provision' CAA section 
110(a)(2)(D)(i)(I), as well as the adequate implementation of [the] SIP 
regarding CAA section 110(a)(2)(E)(i).'' The commenter believes that 
EPA's use of the 4-step interstate transport framework is an effective 
method to address the previously mentioned concerns, but that there 
needs to be adequate implementation and ``more stringent regulations 
reinforced regarding step 3 and step 4, of the 4-step interstate 
transport framework.'' The commenter recommends two ``strategies'' in 
order to make the 4-step framework more stringent. For Step 3, the 
commenter suggests re-evaluating Prevention of Significant 
Deterioration (PSD) regulations, with a focus on ``improving 
standards'' related to Best Available Control Technology (BACT). 
Regarding Step 4, the commenter recommends that EPA adopt measures to 
reduce carbon via a cap-and-trade system.
    Response: These comments are not relevant to the action EPA 
proposed. In the proposed rule, EPA applied the well-established 4-step 
framework for assessing interstate ozone transport to determine whether 
Colorado's infrastructure SIP meets the requirements of CAA section 
110(a)(2)(D)(i)(I). We invited comment on our conclusions with respect 
to Colorado's infrastructure SIP, but did not invite comment on the 
integrity and process of the 4-step framework itself.\4\ Further, we 
determined that Colorado's emissions do not contribute at or above the 
threshold of 1 percent of the 2015 8-hour ozone NAAQS (0.70 parts per 
billion (ppb)) to any downwind nonattainment or maintenance receptor at 
Step 2 of the 4-step interstate transport framework, and thus did not 
reach the steps of the 4-step framework discussed in this comment, 
i.e., analysis of potential emissions controls at Step 3 or permanent 
and federally enforceable control strategies to achieve emissions 
reductions at Step 4.5 6 Thus, the

[[Page 61250]]

commenter's recommended strategies for Steps 3 and 4 are not relevant 
to EPA's determination that Colorado does not significantly contribute 
to nonattainment or interfere with maintenance of the 2015 ozone NAAQS 
in any other state, and that therefore Colorado's infrastructure SIP 
submission satisfies CAA section 110(a)(2)(D)(i)(I).
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    \4\ 87 FR 27054.
    \5\ 87 FR at 27056-58.
    \6\ EPA's determination not to further evaluate Colorado's 
contributions at Steps 3 or 4 of the interstate transport framework 
was additionally supported by the analysis provided in the Uinta 
Basin technical support document (TSD) of this action at proposal, 
evaluating Colorado's emissions contributions in the Uinta Basin 
during wintertime inversion episodes that produce high ozone 
conditions.
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    Additionally, the commenter states that ``concerns regarding the 
2015 Ozone NAAQS infrastructure requirements highlight potential 
problems regarding both the `Good Neighbor Provision' CAA section 
110(a)(2)(D)(i)(I), as well as the adequate implementation of SIP 
regarding CAA section 110(a)(2)(E)(i),'' but the commenter does not 
explain what these concerns or potential problems are. Without knowing 
the specific concerns to which the commenter is referring, EPA cannot 
respond to this part of the comment.

The Center for Biological Diversity

    Comment: The Center asserts that EPA should have used an analytic 
year of 2020 instead of 2023 and that EPA made a ``post hoc 
justification'' for using a 2023 analytic year. The Center states that 
EPA is incorrect that most areas downwind of Colorado have an 
attainment date of August 3, 2024, which is the attainment date for 
2015 ozone moderate nonattainment areas. The Center asserts that EPA 
has delayed ``bumping up'' downwind areas (or determining that these 
areas have failed to attain the 2015 ozone NAAQS by the attainment 
date) and that these areas should be designated moderate instead of 
marginal. The Center also states that Congress' intent under the CAA is 
for EPA to act on SIPs before the marginal attainment date.\7\ The 
Center claims that EPA is not justified in doing an analysis based on 
acting on Colorado's SIP submission after the marginal attainment date 
and also claims that using a 2023 analytic year is inconsistent with 
recent EPA actions related to designations. Additionally, the Center 
asserts that using an analytic year of 2020 would ``allow'' EPA to use 
monitored data in determining downwind nonattainment and maintenance 
monitors. The Center suggests that if EPA were to use a 2020 analytic 
year, the Agency would determine that Colorado needs to reduce the 
State's emissions, and that such a conclusion would benefit several 
downwind areas such as Amador County, California; Dallas-Fort Worth, 
Texas; Houston, Texas; the Northern Wasatch Front, Utah; Phoenix, 
Arizona; San Antonio, Texas; the Uinta Basin, and others.
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    \7\ In accordance with CAA section 181(a)(1), an area designated 
as nonattainment for a revised ozone NAAQS must be classified, at 
the time of designation, as marginal, moderate, serious, severe or 
extreme, depending on the severity of the ozone air quality problem 
in that nonattainment area. Each classification threshold has an 
associated attainment date, as well as other NAAQS implementation-
related provisions.
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    Response: The Center supports its preferred analytic year of 2020 
by arguing that if EPA had used an analytic year of 2020, we would have 
concluded that Colorado has good neighbor obligations that, if met, 
would benefit downwind areas including Amador County, California; 
Dallas-Fort Worth, Texas; Houston, Texas; Northern Wasatch Front, Utah; 
Phoenix, Arizona; San Antonio, Texas; and Uinta Basin, Utah. We do not 
agree that the Center's assertions regarding Colorado's transport 
linkages in 2020 are correct. However, it is not necessary to evaluate 
the technical basis for these claims because the United States Court of 
Appeals for the District of Columbia Circuit (D.C. Circuit) previously 
rejected a similar argument regarding sole reliance on conditions that 
are wholly in the past to assess good neighbor obligations and upheld 
EPA's reasonable interpretation of the good neighbor provision as 
forward-looking.\8\ In that case, Delaware argued that EPA should have 
used data from the year SIP submissions for the 2008 ozone NAAQS were 
due (2011) instead of the future analytic year that EPA used (2017) on 
the theory that EPA would have concluded in that circumstance that 
upwind states had good neighbor obligations with respect to 
Delaware.\9\ The court held that Delaware's argument could not ``be 
reconciled with the text of the Good Neighbor Provision, which 
prohibits upwind States from emitting in amounts `which will' 
contribute to downwind nonattainment.'' The court concluded that 
``[g]iven the use of the future tense, it would be anomalous for EPA to 
subject upwind States to good neighbor obligations in 2017 by 
considering which downwind States were once in nonattainment in 2011.'' 
\10\ Likewise, in the present circumstance, it would be anomalous for 
EPA now in 2022 to consider upwind states' obligations under the good 
neighbor provision based solely on data from years that have already 
passed.
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    \8\ See Wisconsin v. EPA, 938 F.3d 303 (D.C. Cir. 2019).
    \9\ Id. at 322.
    \10\ Id. at 369.
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    For more than two decades, EPA has taken a forward-looking approach 
in evaluating good neighbor obligations; using an analytic year that is 
wholly in the past, as the Center urges, would be inconsistent with the 
Agency's past practice.\11\ Furthermore, even prior to Wisconsin, the 
D.C. Circuit upheld EPA's interpretation of ``will'' in CAA section 
110(a)(2)(D)(i)(I) as being both future-tense and conveying a sense of 
certainty.\12\ EPA's use of forward-looking projections in assessing 
good neighbor obligations here continues to give meaning to both senses 
of the term.\13\ EPA's rationale for the selection of 2023 as the 
appropriate future analytic year for assessing whether Colorado has any 
good neighbor obligations for the 2015 ozone NAAQS was presented in the 
proposed rule in section II.A.2 and was not a ``post hoc'' 
justification as the Center asserts. Further, 2023 continues to be the 
key analytic year that EPA is using in multiple other actions to 
address other states' good neighbor obligations under the 2015 ozone 
NAAQS.\14\
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    \11\ See 63 FR 57356, 57375, 57377, 57386 (October 27, 1998) 
(NOX SIP Call); 70 FR 25162, 25241 (May 12, 2005) (Clean 
Air Interstate Rule (CAIR); 76 FR 48208, 48211 (August 8, 2011) 
(Cross-State Air Pollution Rule (CSAPR); 81 FR 74505, 74526 (October 
26, 2016) (CSAPR Update); 86 FR 23054, 23074 (April 30, 2021) 
(Revised CSAPR Update).
    \12\ North Carolina v. EPA, 531 F.3d 896, 914 (July 11, 2008).
    \13\ See 86 FR at 23074.
    \14\ See, e.g., 87 FR 20036, 20042 (April 6, 2022) (proposing 
good neighbor federal implementation plans (FIPs) for 26 states 
using a 2023 analytic year).
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    Despite the Center's argument to the contrary, using a forward-
looking analysis to inform EPA's evaluation of good neighbor SIP 
submissions pursuant to the requirements of CAA section 
110(a)(2)(D)(i)(I) is not incompatible with EPA using existing record 
information to revise certain designations under CAA section 107(d)(1) 
on remand. When EPA revised some initial area designations for the 2015 
ozone NAAQS on remand after Clean Wisconsin v. EPA,\15\ EPA found it 
appropriate in that specific circumstance to use data available to the 
agency at the time of the initial designations in revising the 
boundaries of some nonattainment areas to avoid introducing 
inconsistencies within and across nonattainment areas, some of which 
were unaffected by the court's remand.\16\ The overall goal of the

[[Page 61251]]

Agency's analytical approach to the action revising initial area 
designations--to avoid introducing inconsistencies across areas--is 
entirely consonant with EPA's approach to addressing good neighbor 
obligations using a consistent analytic year for the entire country, 
which, at the time of this action, is 2023.
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    \15\ 964 F.3d 1145 (D.C. Cir. 2020).
    \16\ 86 FR 67864, 67868-67869 (November 30, 2021); see also EPA, 
Responses to Significant Comments Received on EPA's Revised Response 
to State and Tribal Recommendations for the 2015 Ozone National 
Ambient Air Quality Standards (NAAQS) Addressing El Paso County, 
Texas and Weld County, Colorado at 43-44 (November 2021), available 
in Docket No. EPA-HQ-OAR-2017-0548 (responding to commenters arguing 
EPA should be using the most current information available to the 
Agency in revising designations).
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    Part of the Center's argument appears to be a suggestion for an 
alternative approach to identifying receptors at Step 1 of the 4-step 
framework for the purpose of assessing whether a state has obligations 
under CAA section 110(a)(2)(D)(i)(I). The Center suggests that if EPA 
were to use an analytic year of 2020, then EPA would identify downwind 
air quality issues using only measured values from 2020. But this 
ignores that EPA's methodology for identifying receptors already gives 
consideration to recent measured values, including in 2020, while also 
using forward-looking modeling projections. Using only measured values 
to identify receptors would introduce several problems into EPA's 
methodology.
    EPA explained how the Agency identifies nonattainment and 
maintenance receptors at Step 1 of the 4-step framework for the 2015 
ozone NAAQS in the proposed rule in section II.A.3 and provided more 
detail in our ``Air Quality Modeling Technical Support Document: 2015 
Ozone National Ambient Air Quality Standards Transport SIP Proposed 
Actions.'' \17\ EPA's approach gives independent consideration to both 
the ``contribute significantly to nonattainment'' and the ``interfere 
with maintenance'' prongs of CAA section 110(a)(2)(D)(i)(I), consistent 
with the D.C. Circuit's direction in North Carolina v. EPA.\18\
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    \17\ Available in Docket No. EPA-HQ-OAR-2021-0663 (hereinafter 
``Air Quality Modeling TSD'').
    \18\ 531 F.3d 896, 910-11 (D.C. Cir. 2008).
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     Monitoring sites with future year average design values 
that exceed the NAAQS and that are currently measuring nonattainment 
are considered nonattainment receptors.\19\
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    \19\ 87 FR 27054; Air Quality Modeling TSD at 9.
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     Monitoring sites with projected average design values or 
maximum design values that exceed the NAAQS are projected to be 
maintenance receptors.\20\
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    \20\ Id.
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    EPA's methodology for defining maintenance and nonattainment 
receptors uses projected air quality modeling to capture variability 
such that monitors that may be attaining based on current data may 
still be deemed a ``maintenance receptor.'' Under the Center's idea of 
using only actual monitoring data, it is unclear how EPA would 
distinguish between those monitors which should be maintenance 
receptors and those which are not receptors at all. Additionally, if 
EPA were to use only recorded monitoring data for 2020 in order to 
define receptors and not use modeling, there would be no way to measure 
upwind state contributions to downwind receptors at Step 2 of the 4-
step framework. EPA's analysis uses modeling in order to obtain 
information for both components of the key questions at Steps 1 and 2--
indicating where there are anticipated air quality problems and which 
states are contributing to those problems. Moreover, as discussed 
above, using only past measured data to identify receptors would not 
align with the forward-looking nature of the good neighbor provision.
    In response to the comment arguing that using a 2020 analytic year 
would ``allow'' EPA to use actual monitor data, EPA points out that, in 
fact, the identification of receptors at Step 1 of the 4-step framework 
already considers measured ozone design values from 2020, as explained 
in section 3.1 of the Air Quality Modeling TSD. In other words, while 
EPA uses a future analytic year to define good neighbor obligations, 
our assessment of likely air quality conditions in that future year is 
informed by, among other things, recent and historical ambient air 
quality monitoring data.
    EPA acknowledges that, at the time the Agency originally acted on 
Colorado's infrastructure SIP in the 2020 final rule, good neighbor 
obligations for the 2015 ozone NAAQS should have been met no later than 
the marginal attainment date of August 3, 2021.\21\ But, as explained 
above, the D.C. Circuit has agreed that it is reasonable for EPA to 
look to a future year in evaluating transport obligations, even if the 
Agency would have been able to evaluate an earlier year had they acted 
sooner. Indeed, in EPA's Revised CSAPR Update rule, on remand from the 
D.C. Circuit's decision in Wisconsin, EPA did not continue to assess 
obligations based on a 2017 analytic year (as had been used in the 2016 
CSAPR Update) but instead used 2021, associated with the serious area 
attainment date for the 2008 ozone NAAQS.\22\ Similarly, here, EPA's 
choice of a 2023 analytic year is based on the fact that 2023 air 
quality will impact whether areas attain by the relevant moderate 
attainment date of August 3, 2024.
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    \21\ See Wisconsin, 938 F.3d at 313, 319; Maryland v. EPA, 958 
F.3d 1185, 1203-04 (D.C. Cir. 2020); see also CAA section 181(a); 40 
CFR 51.1303; 83 FR 25776 (June 4, 2018, effective August 3, 2018).
    \22\ See 86 FR 23054, 23057 n.16 (April 30, 2021) (noting that 
2020 was also not appropriate to use since that year too was wholly 
in the past).
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    The Center's contention that EPA should not look to the moderate 
area attainment date because EPA has not yet finalized the Agency's 
action making those areas downwind of Colorado moderate is incorrect. 
EPA has issued a proposed finding, and signed a final finding, that a 
number of marginal areas failed to attain by the 2021 attainment date, 
and per the statute, now that EPA has finalized this determination, 
these areas will be reclassified to moderate by operation of law on the 
effective date of the final rule (30 days after publication in the 
Federal Register).\23\ However, the timing of that action does not 
affect when the moderate attainment date would be. EPA is not permitted 
under the statute to adjust the attainment dates for areas under a 
given classification; that is, no matter when EPA finalizes the 
determination that an area failed to attain by its attainment date and 
reclassifies that area, the attainment date remains fixed, based on the 
number of years from the area's initial designation.\24\ To illustrate 
this point, the attainment date for moderate areas that were designated 
on August 3, 2018 under the 2015 ozone NAAQS is August 3, 2024, 
regardless of when EPA finalizes the action that will reclassify areas 
to moderate. August 3, 2024 is also the attainment date for any area 
that was initially designated moderate under the 2015 ozone NAAQS on 
August 3, 2018. Thus, based on Wisconsin and Maryland, good neighbor 
obligations for the 2015 ozone NAAQS should be met ``as expeditiously 
as practicable but not later than'' the next applicable attainment 
date. For this NAAQS, the next attainment date is the moderate 
attainment date of August 3, 2024.\25\
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    \23\ Proposed Rule, Determinations of Attainment by the 
Attainment Date, Extensions of the Attainment Date, and 
Reclassification of Areas Classified as Marginal for the 2015 Ozone 
National Ambient Air Quality Standards, 87 FR 21842 (April 13, 
2022). Final Rule signed on September 15, 2022.
    \24\ See CAA section 181(a)(1); 40 CFR 51.1303; 83 FR 25776 
(June 4, 2018, effective August 3, 2018).
    \25\ The San Antonio, Texas nonattainment area has a different 
moderate attainment date.
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    For all of these reasons, EPA rejects the Center's contention that 
we should have used a 2020 analytic year to evaluate Colorado's good 
neighbor

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obligations in this action and maintains that selecting 2023 as the 
analytic year is appropriate.
    Comment: As part of their comment that EPA must disapprove 
Colorado's infrastructure SIP submission under CAA section 
110(a)(2)(D)(i)(I), the Center criticizes EPA's modeling for failing to 
properly account for emissions related to EPA's withdrawal of 
California Clean Car Rules Waiver. The Center states that the ``repeal 
of [the withdrawal of] California's waiver to have more stringent 
emissions limits for on-road mobile sources has not yet been 
finalized'' and points to EPA's normal practice of including only 
emissions changes resulting from final regulatory actions in our 
modeling. The Center says that since the repeal of the withdrawal of 
California's waiver has not been finalized, EPA's emissions inventory 
should be based on the on-road mobile sources from states like 
California and Colorado as if they are not complying with their 
respective state's clean car rule requirements, such as the zero 
emissions vehicle (ZEV) requirements and low-emissions vehicle (LEV) 
requirements. The Center believes it is arbitrary for EPA to base their 
emissions inventories on these states having emissions limits for on-
road mobile sources which are not permitted without a preemption 
waiver.
    Response: The Center is correct that it is the Agency's general 
practice to include only emissions reductions from finalized legal and 
regulatory requirements in our ozone transport modeling. EPA's 2023 
modeling using the 2016v2 platform reflects an updated assessment of 
the emissions inventory nationwide based on changes in federal and 
state rules and other relevant changes in the emissions inventory.
    We disagree with the Center that the Agency did not appropriately 
consider emissions changes related to the repeal of the CAA waiver for 
California's Advanced Clean Car program in our emissions inventory and 
subsequent interstate transport modeling. EPA finalized the decision to 
withdraw a 2013 CAA waiver previously provided to California for the 
State's greenhouse gas (GHG) and ZEV programs under section 209 of the 
CAA on September 27, 2019.\26\ However, EPA then reconsidered that 
decision and finalized a repeal of the withdrawal of the CAA waiver of 
preemption for California's GHG and ZEV sale mandate on March 14, 
2022.\27\ Whether it was appropriate to include these emissions changes 
in our 2023 modeling at the time we conducted the modeling is 
effectively moot, since EPA did in fact repeal the withdrawal of the 
waiver by March of this year.
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    \26\ 84 FR 51310.
    \27\ 87 FR 14332.
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    EPA's projected emissions for the updated 2023 modeling used in 
this action use, in relevant part, mobile source emissions inventories 
provided by the California Air Resources Board (specifically, 
EMFAC2017), which incorporate emissions reductions from California's 
GHG emissions standards and ZEV sale mandate, while for the remaining 
states the inventories are based on MOVES3.\28\ MOVES3 reflects the 
impacts of the Tier 3 Motor Vehicle Emission and Fuel Standards rule 
which harmonized the California LEV and federal requirements for low 
emissions vehicles.\29\ ZEV populations in the modeling were based on 
actual registration data for the modeling base year and were grown to 
future years according to Annual Energy Outlook forecasts.\30\ Thus, 
EPA's updated 2023 modeling appropriately included emissions changes 
regarding California's GHG and ZEV sale mandate waiver, as well as LEV 
emissions standards nationwide by virtue of EPA's inclusion of the Tier 
3 program in our modeling. Additionally, the September 27, 2019 
rulemaking did not affect California's low emissions vehicle III (LEV 
III emission standards.)
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    \28\ EPA, Latest Version of MOter Vehicle Emission Simulator 
(MOVES), available at https://www.epa.gov/moves/latest-version-motor-vehicle-emission-simulator-moves (last visited September 19, 
2022).
    \29\ 81 FR 23414, at 23450. As indicated in the Final Rule for 
Control of Air Pollution from Motor Vehicles: Tier 3 Motor Vehicle 
Emission and Fuel Standards, ``The Tier 3 program is identical to 
LEV III in most major respects for light-duty vehicles (and heavy-
duty vehicles . . .)''.
    \30\ See Technical Support Document (TSD) Preparation of 
Emissions Inventories for the 2016v2 North American Emissions 
Modeling Platform, section 4.3.2, in particular Table 4-43. Dated: 
February 2022. (2016v2 TSD). Included under Docket ID No. EPA-HQ-
OAR-2021-0663.
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    Overall, while the Center is correct that it is the Agency's 
general practice to include only emissions reductions from final rules 
in our modeling, there is no merit to the remainder of this comment, 
because EPA has in fact repealed the withdrawal of the waiver as to 
California's GHG and ZEV rules and thus they were appropriately 
incorporated into the modeling.
    Comment: The Center further asserts that EPA wrongly ignored 
receptor values above the level of the NAAQS. The Center points to Step 
2 of the 4-step interstate transport framework, as described in the 
proposed rule for this action,\31\ where the contribution metric is 
defined as the average impact from each state to each receptor on the 
days with the highest ozone concentrations at the receptor based on the 
2023 modeling. The Center states that by using this protocol, ``EPA is 
ignoring impacts from upwind states on days with high ozone 
concentrations, including concentrations above the level of the NAAQS, 
but which aren't necessarily the highest ozone concentration. This is 
ignoring an important aspect of the problem; that is days above the 
level of the NAAQS but still not the highest days.'' The Center states 
that EPA criticized Colorado for using the same calculations when the 
State submitted its designations recommendations for the 2015 ozone 
NAAQS, ``not because those areas violated the NAAQS but rather because 
they contributed to violations.'' \32\ The Center concludes that there 
is no difference between intra-state contribution and inter-state 
contribution and that it is arbitrary for EPA to ignore the above-the-
NAAQS level days because failure to address them means downwind areas 
will continue to struggle to reach attainment.
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    \31\ 87 FR 27055.
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    Response: Through the development and implementation of the CSAPR 
rulemakings as well as prior regional rulemakings pursuant to the 
interstate transport provision, EPA, working in partnership with 
states, developed the 4-step interstate transport framework to evaluate 
states' obligations to eliminate interstate transport emissions under 
the good neighbor provision for the ozone NAAQS. This includes Step 2 
of the 4-step framework which identifies states that impact air quality 
problem (nonattainment or maintenance) receptors in downwind states 
sufficiently such that the states are considered ``linked'' and 
therefore warrant further review and analysis of their air quality 
impacts. As the Center notes in their comment, EPA evaluated Colorado's 
contribution (as we did every other state's) based on the average 
relative downwind impact calculated over multiple days. The number of 
days used in calculating the average contribution metric has 
historically been determined in a manner that is generally consistent 
with EPA's recommendations for projecting future year ozone design 
values.\33\ Our ozone attainment demonstration modeling guidance at the 
time CSAPR was originally promulgated recommended using all model-
predicted days above

[[Page 61253]]

the NAAQS to calculate future year design values.\34\ In 2014, EPA 
issued draft revised guidance that changed the recommended number of 
days to the top-10 model predicted days.\35\ For the CSAPR Update, 
promulgated in 2016, EPA transitioned to calculating design values 
based on this draft revised approach. The revised modeling guidance was 
finalized in 2018.\36\ Since that time EPA has consistently calculated 
both the ozone design values and the contributions based on the top-10 
day approach. As this guidance is finalized, we will continue to base 
our average contribution metric in accordance with the top-10 day 
approach. Thus, EPA disagrees with the Center's claim that EPA's 
current modeling approach for identifying contributing upwind states is 
arbitrary and contrary to law or that the Agency must disapprove 
Colorado's good neighbor SIP revision for the 2015 ozone NAAQS. 
Further, the Center has not supplied any information establishing that, 
had EPA used a larger set of days with high ozone concentrations at 
identified out of state nonattainment or maintenance receptors to 
calculate contribution values at Step 2, Colorado's contribution would 
then be found to exceed the 1 percent of NAAQS threshold at any of 
these receptors.
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    \33\ The Center's comment is only relevant to EPA's summertime 
ozone analysis since the Agency's wintertime ozone analysis for the 
Uinta Basin does not use model predicted design values.
    \34\ EPA, ``Guidance on the Use of Models and Other Analyses for 
Demonstrating Attainment of Air Quality Goals for Ozone, 
PM2.5, and Regional Haze,'' 2007, available at https://www.epa.gov/sites/default/files/2020-10/documents/final-03-pm-rh-guidance.pdf.
    \35\ EPA, ``Draft Modeling Guidance for Demonstrating Attainment 
of Air Quality Goals for Ozone, PM2.5, and Regional 
Haze,'' 2014, available at https://www.epa.gov/sites/default/files/2020-10/documents/draft-o3-pm-rh-modeling_guidance-2014.pdf.
    \36\ EPA, ``Modeling Guidance for Demonstrating Air Quality 
Goals for Ozone, PM2.5 and Regional Haze,'' 2018, 
available at https://www.epa.gov/sites/default/files/2020-10/documents/o3-pm-rh-modeling_guidance-2018.pdf.
---------------------------------------------------------------------------

    Additionally, EPA disagrees with the Center's statement that EPA 
``criticized'' Colorado for using the same calculations when the State 
submitted its designations recommendations for the 2015 ozone NAAQS. 
The Center refers to page 28 of EPA's final designation technical 
support document (designation TSD) \37\ supporting Colorado's 
designations for the 2015 ozone NAAQS, and we believe the Center is 
referring to EPA's assessment of the Denver nonattainment area's 
meteorology.
---------------------------------------------------------------------------

    \37\ EPA, ``Colorado: Denver Metro/North Front Range 
Nonattainment Area Final Area Designations for the 2015 Ozone 
National Ambient Air Quality Standards Technical Support Document 
(TSD).'' Docket No. EPA-R08-OAR-2019-0140.
---------------------------------------------------------------------------

    As an initial matter, the technical analysis and process for 
designations falls under a separate set of guidance and policies than 
the modeling guidance that EPA follows for purposes of interstate 
transport.\38\ Thus, we do not agree that EPA's designation TSD 
methodology should be considered relevant or even analogous to EPA's 
Step 2 analysis in this action. Nonetheless, during the process of 
designating nonattainment areas, the evaluation of meteorological data 
helps to assess the fate and transport of emissions contributing to 
ozone concentrations and to identify areas potentially contributing to 
the monitored violations. During a designation review for a new NAAQS, 
the results of meteorological data analysis may inform the 
determination of nonattainment area boundaries. At the time of the 2015 
ozone NAAQS designations, to determine how meteorological conditions, 
including, but not limited to, weather, transport patterns, and 
stagnation conditions, could affect the fate and transport of ozone and 
precursor emissions from sources in the area, EPA evaluated 2014-2016 
HYSPLIT (Hybrid Single-Particle Lagrangian Integrated Trajectory) 
trajectories at 100, 500, and 1000 meters above ground level that 
illustrate the three-dimensional paths traveled by air parcels to a 
violating monitor. In EPA's 2015 ozone NAAQS designation TSD for 
Colorado, the Agency provided figures of the 24-hour HYSPLIT back 
trajectories for each exceedance day for the violating monitors in 
2013-2015, while the State of Colorado focused on the four highest 
exceedance days in each of those three years in its own designation 
TSD. EPA concluded that even though EPA's total number of trajectories 
differ from those conducted by the State of Colorado, the geographic 
distribution of trajectory hours was the same between the two 
analyses.\39\ EPA did not criticize Colorado's methodology per se in 
the designations TSD but simply identified a difference in approach 
while noting that it produced the same result. However, this was in the 
context of EPA's comparison of HYSPLIT back trajectory data for 
purposes of evaluating the designation of a nonattainment area, which 
is entirely separate from the use of photochemical grid modeling 
projections for purposes of assessing contribution at Step 2 of the 4-
step interstate transport framework. Therefore, the Center's statement 
not only misinterprets the content and purpose of EPA's 2015 ozone 
NAAQS designation TSD for Colorado, but also mischaracterizes its 
significance to this action.\40\
---------------------------------------------------------------------------

    \38\ See EPA, ``EPA Guidance on the Area Designations for the 
2015 Ozone NAAQS,'' available at https://www.epa.gov/ozone-designations/ozone-designations-guidance-and-data#A.
    \39\ EPA, ``Colorado: Denver Metro/North Front Range 
Nonattainment Area Final Area Designations for the 2015 Ozone 
National Ambient Air Quality Standards Technical Support Document 
(TSD).'' Docket No. EPA-R08-OAR-2019-0140.
    \40\ The Center also fails to recognize that focusing on the 
top-10 days of ozone concentrations, as EPA does for purposes of 
evaluating contribution at Step 2, can sometimes utilize days that 
are lower than the level of the NAAQS if not all 10 days used for 
these calculations exceed the NAAQS. The Center's assumption that 
using only the top-10 days necessarily excludes other days that 
exceed the NAAQS is not correct. As EPA explained in our 2018 
modeling guidance, using the top-10 highest days yields an 
analytically robust result, can be applied even as NAAQS are 
revised, and yields better estimates than the previous guidance 
approach. See ``Modeling Guidance for Demonstrating Air Quality 
Goals for Ozone, PM2.5 and Regional Haze,'' 2018 at 105.
---------------------------------------------------------------------------

    Comment: The Center claims that ``EPA's failure to analyze 
Colorado's contribution to wintertime ozone levels is arbitrary and 
capricious'' and therefore the Agency must disapprove the State's good 
neighbor SIP. The Center states that wintertime ozone is an issue in 
basins in the Western United States where oil and gas extraction 
occurs, not just in the Uinta Basin area. The Center asserts that EPA 
arbitrarily treated the Uinta Basin as unique. The Center points to the 
Upper Green River Basin area in Wyoming, which was designated as 
nonattainment for the 2008 ozone NAAQS due to wintertime ozone.\41\
---------------------------------------------------------------------------

    \41\ 77 FR 30088 (May 21, 2012).
---------------------------------------------------------------------------

    Additionally, the Center notes that some areas, though not 
designated as nonattainment for wintertime ozone, will have a difficult 
time coming into attainment without addressing wintertime ozone. The 
Center cites the Denver Metro/North Front Range (DMNFR) nonattainment 
area as an example and provides March 2021 monitor values at various 
Colorado monitors in support. The Center further states that the DMNFR 
monitor values cannot be explained by stratospheric intrusion or 
wildfire. While the Center notes that they do not expect EPA to analyze 
Colorado's ``interstate'' contribution to Colorado, the Center states 
that DMNFR values demonstrate that EPA is wrong to claim that the Uinta 
Basin's wintertime ozone problem is unique. The Center asserts that EPA 
must ``do an analysis, using the same methodology as summertime ozone, 
for other Western areas with significant oil and gas production and 
winter weather to determine if Colorado is significantly contributing 
to them.'' Additionally, the Center claims that ``while EPA uses a

[[Page 61254]]

1% threshold for determining if there is significant contribution to 
summertime ozone, EPA appears to be using a 50% or more, that is upwind 
states would have to be the main cause, threshold for significant 
contribution for wintertime ozone.'' The Center also insists that ``EPA 
must do an analysis to determine which states contribute more than 1% 
to wintertime ozone in the Uinta Basin, the Denver Metro/North Front 
Range, and other areas with areas with wintertime ozone problems and 
then come up with emission reduction requirements for those upwind 
contributors.'' Finally, the Center states that EPA previously 
redefined the ozone season for Colorado and many other Western States 
to be year-round and that the Agency ``is acting like the ozone season 
for Colorado and other Western States is only the summertime but EPA 
cannot undo its previous rulemaking to create year round ozone seasons 
via the preamble to this proposed rule.''
    Response: EPA agrees with the Center that the occurrence of high 
levels of ozone in the wintertime, in the presence of snow cover and 
emissions from oil and gas operations, is not limited to the Unita 
Basin. EPA used the word ``unique'' in two separate instances in the 
proposed rule and in the accompanying Uinta Basin Technical Support 
Document,\42\ but did not mean to suggest that the Uinta Basin is 
unique in experiencing wintertime ozone events. Instead, in both the 
proposal and the Uinta Basin TSD, EPA referred to the Uinta Basin's 
unique topography.\43\ Also, in the proposal, EPA referred to the 
unique analytical challenges in assessing whether there is interstate 
transport of ozone and its precursors from Colorado during wintertime 
episodes in Utah.\44\
---------------------------------------------------------------------------

    \42\ EPA, Technical Support Document (TSD) Ozone Transport 
Analysis: Colorado and the Uinta Basin Nonattainment Area, April 
2022 (Uinta Basin TSD).
    \43\ 87 FR at 27057; Uinta Basin TSD at 5.
    \44\ 87 FR at 27057.
---------------------------------------------------------------------------

    However, we do not agree that we did not conduct an analysis of the 
potential for transport of ozone under these circumstances. We 
performed a separate analysis for the Uinta Basin because, as explained 
in the Uinta Basin TSD, we acknowledged that the modeling we would 
otherwise use is not reliable for projecting high ozone levels 
associated with wintertime inversions in that area. Additionally, the 
Uinta Basin is the only wintertime ozone area that is currently 
designated as nonattainment or maintenance for the 2015 ozone NAAQS and 
is the only area with high wintertime ozone that is immediately 
adjacent to the Colorado border. As explained in the Uinta Basin TSD, 
high ozone levels during the winter in the Uinta Basin area are 
associated with stagnant meteorological conditions that result in the 
build-up of local ozone precursor emissions and snow cover which 
enhances the reflectivity of solar radiation which, in turn, 
accelerates photochemical reactions of the trapped precursors to form 
locally high ozone concentrations. Because of the stagnant conditions, 
transport of precursor emissions from outside the immediate area are 
likely to be minimal, at most. In any case, the Center has not provided 
any information to support its notion that Colorado significantly 
contributes to nonattainment or interferes with maintenance in the 
Uinta Basin, much less in other areas farther from Colorado 
experiencing high wintertime ozone levels.
    The Center cites the Upper Green River Basin area as another area 
that periodically experiences wintertime ozone. EPA designated this 
area as nonattainment for the 2008 ozone NAAQS for wintertime 
ozone.\45\ We are aware that one of the monitors in this nonattainment 
area is violating the 2015 ozone NAAQS according to the 2021 design 
value; however, as discussed below, we do not believe emissions from 
Colorado contribute to this design value.\46\
---------------------------------------------------------------------------

    \45\ 77 FR 30088 (May 21, 2012). Then, on May 4, 2016 (86 FR 
26697), EPA published a determination that the Upper Green River 
Basin Area attained the 2008 ozone NAAQS based on 2012 to 2014 
ambient air quality data.
    \46\ Monitor 560350099 in Sublette, Wyoming is measuring 74 ppb 
according to EPA's current quality-assured monitor design value 
data. https://www.epa.gov/air-trends/air-quality-design-values#dvtool.
---------------------------------------------------------------------------

    The Upper Green River Basin is located in western Wyoming, about 
half-way between the southern and northern borders of the State. The 
southernmost border of the nonattainment area is at least 80 miles from 
the closest Colorado border. In EPA's technical support document that 
supported the Agency's designation for the Upper Green River Basin 2008 
ozone NAAQS nonattainment area, we stated that ``ozone exceedances 
almost always occur when winds are low indicating that there is little 
to no transport of ozone or precursors from distant sources outside the 
proposed nonattainment area.'' \47\ The Agency also indicated that the 
wind field trajectory analyses led to the conclusion that regional 
transport for the area is insignificant, and local-scale precursor 
emissions transport is the dominant means of precursor transport during 
high ozone periods.\48\ Additionally, during a high fidelity trajectory 
analysis conducted by Wyoming in support of its recommendation for the 
southern boundary of the Upper Green River Basin nonattainment area, 
emissions from sources south of the nonattainment boundary were 
consistently transported east and out of the region without entering 
the area with violating monitors.\49\ Furthermore, multiple research 
studies have found that wintertime ozone is a local phenomenon that is 
not affected by long range transport.\50\ Based on this information, 
EPA finds that it is reasonable to conclude that Colorado does not 
significantly contribute to nonattainment or interfere with maintenance 
of the 2015 ozone NAAQS (or the 2008 ozone NAAQS) in the Upper Green 
River Basin area. Additionally, as we stated previously, the Center has 
not provided any information to support their notion that Colorado 
significantly contributes to nonattainment or interferes with 
maintenance during wintertime ozone events in the Upper Green River 
Basin, or any other western area experiencing wintertime ozone events.
---------------------------------------------------------------------------

    \47\ EPA, Wyoming Area Designations for the 2008 Ozone National 
Ambient Air Quality Standards TSD at 46-48, located in Docket No. 
EPA-R08-OAR-2019-0140.
    \48\ Id.
    \49\ Id.
    \50\ See generally Oltmans, Samuel et al., ``O3, CH4, CO2, CO, 
NO2 and NMHC aircraft measurements in the Uinta Basin oil and gas 
region under low and high ozone conditions in winter 2012 and 
2013,'' Elementa: Science of the Anthropocene, 4, 000132, (2016).; 
ENVIRON, ``Final Report: 2014 Uinta Basin Winter Ozone Study,'' 
February 2015, available at https://documents.deq.utah.gov/air-quality/planning/air-quality-policy/DAQ-2015-021002.pdf (last 
visited September 19, 2022) (``ENVIRON Final Report'').
---------------------------------------------------------------------------

    As the Center acknowledges, their comments about the DMNFR 
nonattainment area are not relevant to this rulemaking because the 
issue EPA is addressing under CAA section 110(a)(2)(D)(i)(I) is whether 
Colorado contributes significantly to nonattainment or interferes with 
maintenance in other states, not Colorado's own nonattainment and 
maintenance problems.
    EPA disagrees with the Center's assertion that EPA should conduct 
the same analysis for wintertime ozone transport as the Agency does for 
summertime ozone transport. As EPA explained in our proposed approval 
and the Uinta Basin TSD, there are no reliable models that accurately 
predict wintertime ozone levels and contributions.\51\ In addition, 
currently

[[Page 61255]]

available emissions inventories are not sufficiently refined to 
accurately estimate emissions from oil and gas production during 
transient wintertime events. Therefore, in this action, EPA relied on 
other methods of analysis as opposed to computer-based modeling when 
reviewing wintertime ozone areas.\52\
---------------------------------------------------------------------------

    \51\ 87 FR at 27057; Uinta Basin TSD at 8 (``Current state-of-
the-science national scale modeling tools and inventories are not 
designed to characterize these conditions in a manner that would 
provide confidence in quantifying interstate contributions.'') and 
Figure 3 (showing how the model ``understate measured data by an 
extremely large amount'' for wintertime ozone).
    \52\ See ``Utah: Northern Wasatch Front, Southern Wasatch Front, 
and Uinta Basin Final Area Designations for the 2015 Ozone National 
Ambient Air Quality Standards Technical Support Document (TSD)'' and 
the Uinta Basin TSD specific for this action.
---------------------------------------------------------------------------

    The Center is incorrect to claim that the Agency appears to be 
using 50 percent or more of the NAAQS as a threshold for significant 
contribution for wintertime ozone for the Uinta Basin. EPA has reviewed 
our proposal and the Uinta Basin TSD for this action and cannot find 
what the commenter is referencing, nor has commenter provided a 
citation. The Center seems to think EPA is using a higher contribution 
threshold for wintertime ozone than we do for a Step 2 analysis for 
summertime ozone. This is incorrect. For summertime ozone, EPA is able 
to use current state-of-the science photochemical modeling for Step 1 
and Step 2 and this allows us to set and use a contribution threshold 
of 1 percent for the purpose of evaluating a state's contribution to 
nonattainment or maintenance of the 2015 8-hour ozone NAAQS (i.e., 0.70 
ppb) at downwind receptors. As explained previously, since our current 
photochemical modeling does not fully capture wintertime ozone events, 
we cannot rely on modeling to assess a state's contribution in 
wintertime ozone areas. However, knowing that the Uinta Basin has 
nonattainment monitors, EPA performed an extensive analysis, as 
documented in the Uinta Basin TSD for this action. The results of the 
in-depth analysis conducted in the Uinta Basin TSD support EPA's 
conclusion that interstate transport of air pollution from Colorado 
does not significantly contribute to nonattainment or interfere with 
maintenance of the 2015 ozone NAAQS in the Utah portion of the Uinta 
Basin.
    In regard to the Center's argument about year-round ozone, the 
Center does not provide a cite where EPA ``redefined the ozone season'' 
so we are unable to address that assertion specifically. With respect 
to the Center's statement that ``EPA is acting like the ozone season 
for Colorado and other Western States is only the summertime,'' EPA 
disagrees. By the Center's own admission, EPA designated the Upper 
Green River Basin area in Wyoming as nonattainment for the 2008 ozone 
NAAQS based on wintertime ozone. Additionally, in the Uinta Basin TSD 
for this very action, EPA provided an in-depth analysis on whether 
Colorado significantly contributed interstate transport air pollution 
to a 2015 ozone nonattainment area for wintertime ozone, the Uinta 
Basin. Thus, EPA acknowledges that ozone nonattainment can be a 
wintertime problem and thoroughly addressed whether emissions from 
Colorado significantly contribute to nonattainment or interfere with 
maintenance of the 2015 ozone NAAQS in those areas in the proposed 
rule, the Uinta Basin TSD for this action, and in this final action.
    In summary, EPA disagrees with the Center's claims that EPA failed 
to properly analyze Colorado's contribution to wintertime ozone 
nonattainment and maintenance of the 2015 ozone NAAQS and that we must 
disapprove the State's good neighbor SIP provisions for the 2015 ozone 
NAAQS.
    Comment: The Center challenges the emissions inventory on which 
EPA's 2023 modeling is based, asserting that EPA ignored increased 
emissions from the construction and operation of the Uinta Basin 
Railway in our emissions inventory platform and modeling. The Center 
notes that the U.S. Surface Transportation Board (STB) recently 
approved the construction and operation of the Uinta Basin Railway, ``a 
planned 88-mile long railway that would transport crude oil from Myton 
and Leland Bench, Utah to Kyune, Utah.'' According to the Center, by 
approving a cheaper means of transporting crude oil to the Gulf Coast 
than the trucking industry, the oil railway is intended to quadruple 
oil production in the Uinta Basin from roughly 90,000 barrels per day 
to 350,000 barrels per day. The Center indicates that in order to meet 
that increased oil demand, up to 3,330 new wells would need to be 
drilled in the Uinta Basin over the next 15 years, also increasing the 
number of trucking miles to support the oil fields. The Center also 
points to a Uinta Basin Railway final environmental impact statement 
(EIS) conducted by STB that estimates that after 15 years, and under a 
high oil production scenario,\53\ the annual emissions associated with 
oil and gas development, including trucking, for carbon monoxide (CO), 
nitrogen oxides (NOX), and volatile organic compounds (VOC) 
would be 4,454 tons per year (tpy), 3,146 tpy, and 5,558 tpy, 
respectively. The Center believes these emissions are underestimated. 
The Center further cites EIS estimates of annual emissions associated 
with rail operations along the 88-mile long rail line, excluding 
downline emissions in Utah and Colorado, for CO, NOX, and 
VOCs of 405 tpy, 1,056 tpy, and 40 tpy, respectively. The Center also 
includes a table of estimated downline emissions of criteria pollutants 
from the increase in trains traveling in Colorado per day, and states 
that NOX and VOC emissions along downline segments 
(excluding emissions in attainment areas) would total 5,771.05 tpy and 
205.33 tpy, respectively, and CO emissions would total 2,076.41 tpy. 
The Center concludes that ``EPA must revise its analysis to consider 
these increased emissions caused by the U.S. Government's final 
approval of the Uinta Basin Railway.'' The Center states that the 
approval by the STB ``is a final action by the federal government 
itself'' and ``EPA cannot justify ignoring it based on a claim that EPA 
does not consider future actions which are not final actions.''
---------------------------------------------------------------------------

    \53\ For the EIS, the STB created two potential scenarios for 
future oil development in the Uinta Basin, a low oil production 
scenario and a high oil production scenario. These scenarios 
corresponded to estimated ranges of rail traffic. Under the low oil 
production scenario, total oil production in the Uinta Basin would 
increase by an average of 130,000 barrels per day compared to 
historical production levels. Under the high oil production 
scenario, total oil production in the Uinta Basin would increase by 
an average of 350,000 barrels per day. In the EIS, STB's Office of 
Environmental Analysis (OEA) notes that some of the assumptions made 
here are conservative and therefore may overstate the total future 
oil production in the Basin and the potential impacts. Surface 
Transportation Board, Final Environmental Impact Statement, August 
6, 2021 (Final EIS), at 3.15-4.
---------------------------------------------------------------------------

    Response: The STB, which provided the notice of approval as well as 
the EIS to which the Center refers to in their comment, is an 
independent federal agency that is charged with the economic regulation 
of various modes of transportation, primarily freight rail. The STB's 
Office of Environmental Assessment (OEA) prepared an EIS pursuant to 
the National Environmental Policy Act (NEPA). The NEPA process is 
intended to assist the STB and the public in identifying and assessing 
the potential environmental consequences of a proposed action before a 
decision on a proposed action. In a December 21, 2021 document the STB 
authorized construction and operation of the proposed rail line and, 
among three build alternatives, specifically authorized the Whitmore 
Park Alternative because it would avoid and

[[Page 61256]]

minimize major environmental impacts. EPA is aware of the STB's EIS and 
final decision; in fact, as part of the comment process for the EIS, 
EPA filed comments on September 2, 2021, recommending certain changes 
to an air emissions dispersion model that the OEA ran as part of the 
environmental review process.\54\
---------------------------------------------------------------------------

    \54\ EPA expressed concern that OEA's use of a ``flagpole 
height'' (i.e., the height above the ground for which the model 
predicts the concentration of a pollutant) for one of the modeling 
scenarios described in the final EIS might under-predict air 
pollutant concentrations for that modeling scenario. In response to 
EPA's letter, OEA reran the model scenario without using a flagpole 
height and found the new results to be identical to the results 
reported in the final EIS.
---------------------------------------------------------------------------

    The Center's comments suggest that since the STB issued a final EIS 
and authorized the Railway construction and operation, then the 
emissions predicted in the EIS (and particularly the high oil 
production scenario) should be considered final as well and should have 
been incorporated into EPA's modeling for purposes of assessing 
Colorado's contribution to nonattainment and interference with 
maintenance for the 2015 ozone NAAQS in other states.
    Our 2016v2 modeling of 2023 did not include projected increases in 
emissions from the Uinta Basin Railway project or from the associated 
projected increase in emissions of ozone precursor emissions from 
expanded oil and gas operations that are associated with the Uinta 
Basin Railway. However, we disagree with the Center that this potential 
increase in emissions would change our analysis for Colorado for 
several reasons.
    First, any potential increase in emissions in Utah associated with 
the Railway is not relevant to assessing Colorado's good neighbor 
obligations. The Center does not explain how projected emissions 
increases due to the construction and operation of the Uinta Basin 
Railway as a whole are relevant to whether emissions from Colorado 
contribute significantly to nonattainment or interfere with maintenance 
for the 2015 ozone NAAQS in other states. The selected Whitmore Park 
Alternative extends approximately 88 miles from terminus points in the 
Uinta Basin from around Myton, Utah, and Leland Bench, Utah, to an 
existing rail line near Kyune, Utah. The EIS does not specify if the 
possible new well drilling and trucking could occur from wells outside 
the State of Utah as well as inside the State. However, the final EIS 
indicated that OEA assumed that future oil and gas development, 
including well drilling and operation along with construction and 
operation of related facilities, such as pipelines, would occur 
throughout the Uinta Basin in the fields shown in Figure 3.15-1 of the 
EIS.\55\ None of these fields within the cumulative impacts analysis 
study area--which extends approximately 18 miles into the Yampa 
Intrastate Air Quality Control Region in Colorado--are located within 
Colorado.\56\
---------------------------------------------------------------------------

    \55\ Final EIS, Section 3.15.4.
    \56\ Final EIS, Section 3.25-3, Figure 3.15-1.
---------------------------------------------------------------------------

    We also note that in the EIS, OEA identified 27 reasonably 
foreseeable future actions within the area of the cumulative impacts 
study that could have cumulative impacts in addition to estimated 
additional exploration and drilling of oil wells. We again note that 
none of these activities were estimated to take place within 
Colorado.\57\
---------------------------------------------------------------------------

    \57\ Final EIS, Section 3.15-2.
---------------------------------------------------------------------------

    Therefore, while we do not know for certain where or in which state 
drilling would occur, estimations indicate that most, if not all, of 
the expanded production and exploration (and its associated foreseeable 
future actions) would occur within Utah. It is not possible to 
determine with much certainty what emissions may be released in 
Colorado based on the information supplied by the Center or in the EIS, 
or when, or in what quantity these emissions would occur.
    Further, the STB approval for construction and operation of the 
Railway does not in itself equate to approval of any new oil and gas 
development or drilling in the small portion of the Uinta Basin area 
located in Colorado. We do not know how many of the high oil production 
scenario's estimated 3,330 wells will be drilled and operating and by 
what year (e.g., the total amount of wells is not expected until after 
15 years), nor do we know what controls or limits they will be 
operating under. We also do not know if wells in the Uinta Basin will 
be operating at the high oil production scenario (3,330 wells), the low 
oil production scenario (1,245 wells), or some other production level. 
Thus, the emissions associated with increased well development because 
of the Uinta Basin Railway--to the extent any such development may 
occur in the small portion of the Uinta Basin that is located in 
Colorado--are too speculative to assume they would impact our analysis 
of potential ozone transport from Colorado.
    The Center points to the downline segment analysis of railroad 
emissions that extended to Denver, Colorado.\58\ The EIS states that 
the total NOX and VOC emissions at any particular downline 
location/segment will vary depending on total train traffic, local 
background concentrations, and local topographic and meteorological 
conditions.\59\ Further, the EIS states ``that increases in 
concentrations measured at air quality monitoring sites, if any, are 
expected to be negligible'' and that ``[t]he increased downline rail 
traffic associated with the proposed rail line would not lead to a 
violation of the NAAQS for counties that are in attainment, and would 
not increase the severity of conditions in counties that are not in 
attainment.'' \60\ Nonetheless, assuming there may be some increase in 
railroad emissions in Colorado associated with the Uinta Basin Railway 
project, these emissions increases are too small when viewed in 
comparison with the total amount of ozone-precursor emissions from 
Colorado to reasonably be expected to alter the results of our modeling 
at Step 1 and Step 2. Even an increase in NOX emissions of 
5,771.06 tpy and in VOC emissions of 205.33 tpy would be a very small 
change in the total statewide emissions of these pollutants from 
Colorado, which are projected in 2023 to be 145,621 tpy NOX 
and 555,631 tpy VOC.\61\ Considering that our current 2023 modeling 
indicates that the largest impact Colorado makes at any downwind 
receptor is only 0.20 ppb in 2023 (Denton County, Texas, Site ID 
481210034), this very small change in statewide emissions cannot 
reasonably be anticipated to change our modeling 
results.62 63
---------------------------------------------------------------------------

    \58\ See Final EIS, Section 3.7.
    \59\ Final EIS at 3.7-17.
    \60\ Id.
    \61\ Annual State and County Summaries of Emissions Used in Air 
Quality Modeling, US Inventory State SCC 2016v2 20 aug2021, Federal 
Implementation Plan Addressing Regional Ozone Transport for the 2015 
Primary Ozone National Ambient Air Quality Standard, Docket Id. EPA-
HQ-OAR-2021-0668-0100_attachment_3.
    \62\ In addition, as evident from our analysis in the Uinta 
Basin TSD, these downline railroad emissions in Colorado would only 
be relevant to assessing transport into the Uinta Basin to the 
extent those emissions are occurring within the Colorado portion of 
the Uinta Basin itself. This is because our analysis in the TSD 
shows that emissions from outside the Uinta Basin do not transport 
into the Basin during wintertime inversion conditions. The emissions 
from trains passing through the Colorado portion of the Uinta Basin 
during a wintertime inversion episode would be only a very small 
fraction of the total railroad emissions increase projected in 
Colorado in the EIS, as presented in the table on page 8 of the 
Center's comments. Such a small emission increase would not be 
enough to change our conclusion in the Uinta Basin TSD that 
emissions from Colorado do not significantly contribute to the ozone 
issues in the Utah portion of the Uinta Basin.
    \63\ Design values and contributions at individual monitoring 
sites nationwide are provided in the file 
``2016v2_DVs_state_contributions.xlsx,'' which is included in Docket 
No. EPA-HQ-OAR-2021-0663.

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[[Page 61257]]

    The estimations of emissions included in the information provided 
by the Center and in the EIS are largely influenced by what eventual 
production levels will occur in the Uinta Basin following the 
completion of the Uinta Basin Railway project. The production rates and 
resulting changes to emissions in the Uinta Basin and any downline 
emissions stemming from the project can be influenced by a multitude of 
factors, including how long it takes to complete the project, as well 
as various market condition factors such as general domestic and global 
economic conditions, commodity pricing, and the strategic and capital 
investment decisions of oil producers and their customers.\64\ In OEA's 
analysis in the EIS, conservative assumptions were generally made when 
evaluating air quality impacts (i.e., modeling air quality impacts 
using a production value of 5,750 wells, well above the estimated 3,330 
wells under the high oil production scenario).65 66 However, 
without increased certainty on when this project will be completed (and 
how that relates to air quality conditions at that time), how quickly 
production in the Uinta Basin will change as a result of the 
construction, or how much production will change, it is not appropriate 
nor is it feasible, at this time, for EPA to consider the inclusion or 
consideration of any changes in emissions as a result of the Uinta 
Basin Railway project in this action. Additionally, there are other 
factors that could counterbalance any projected increase in emissions 
in Colorado once the Uinta Basin Railway is in operation, including 
possible emissions reductions that might occur from avoided crude oil 
truck trips into or through Colorado. This degree of uncertainty makes 
it too difficult for EPA to determine what the actual impacts may be 
from this project at this time, though we recognize the potential need 
to assess the air quality impacts of this project in the future 
(particularly as related to an increase in emissions from Utah); 
however, EPA is confident that the emissions change in Colorado that 
could result from this project would not be sufficient to change our 
conclusions in this action.
---------------------------------------------------------------------------

    \64\ Final EIS, Section 3.15-3.
    \65\ Final EIS, Section 3.15-32.
    \66\ Based on Bureau of Land Management (BLM), ``Bureau of Land 
Management Monument Butte Oil and Gas Development Project 
Environmental Impact Statement,'' 2016. Final Environmental Impact 
Statement for Newfield Exploration Corporation Monument Butte Oil 
and Gas Development Project in Uintah and Duchesne Counties, Utah.
---------------------------------------------------------------------------

    In summary, EPA disagrees with the Center's comments that EPA's 
current modeling and analysis fails to appropriately consider predicted 
direct or indirect emissions from the construction and operation of the 
Uinta Basin Railway. Based on our review of the available information, 
any potential increase in emissions in Colorado from this project are 
too small and too speculative to reasonably be anticipated to change 
the results either of our 2023 modeling analysis at Steps 1 and 2, or 
our assessment of the potential for transport from Colorado within the 
Uinta Basin.
    Comment: The Center asserts that EPA must disapprove Colorado's 
infrastructure SIP submission under CAA section 110(a)(2)(E) (adequate 
resources and authority) because the State of Colorado lacks adequate 
legal authority to regulate emissions from agriculture sources. The 
Center quotes Colorado Revised Statutes (C.R.S.) 25-7-109(8)(a) and 
argues that the provision prohibits Colorado from regulating 
agriculture sources other than those that are major sources. The Center 
states that Colorado cannot apply RACT or protect visibility or air 
quality related values for Class I areas from agriculture facilities.
    Furthermore, the Center asserts that EPA must also disapprove the 
SIP under CAA section 110(a)(2)(D) (interstate transport prong 4) and 
110(a)(2)(J) (consultation with government officials, public 
notification, and PSD and visibility protection) because agriculture 
emissions can cause visibility impartment. Additionally, the Center 
argues that EPA must disapprove the SIP submission under section 
110(a)(2)(A) (emissions limits and other control measures) because, 
according to the Center, Colorado cannot assure that it will maintain 
the NAAQS because the State lacks the legal authority to regulate 
emissions from agriculture and pesticides.
    The Center asserts that on remand, EPA wasted the Tenth Circuit's 
and the Center's time because, according to the Center, EPA says the 
same thing on remand that they said before remand. The Center 
acknowledges a letter from Colorado but argues that Colorado's 
statement that it regulates agricultural sources through minor source 
permitting is not true because Colorado has never issued a minor source 
air permit for a farm or concentrated animal feeding operations (CAFO) 
and that EPA has not provided evidence to the contrary. The Center 
further argues that C.R.S. 25-7-109(8)(a) does not mention minor source 
permitting as an exception and that minor sources are not title V, PSD, 
or non-attainment new source review (NSR) sources. Furthermore, the 
Center points out that there are no New Source Performance Standards 
for CAFOs.
    The Center further asserts that fugitive emissions are not included 
in determining if most sources are major. The Center states that 
pesticides are a major contributor to ozone formation and animal waste 
is a major contributor to visibility impairment and interference with 
air quality related values. The Center argues that Colorado cannot 
regulate fugitive emissions based on the plain language of C.R.S. 25-7-
109(8)(a).
    The Center also challenges EPA's interpretation of C.R.S. 25-7-
109(8)(a) that if it is necessary to regulate agricultural sources 
beyond those that are major sources in order to attain or maintain the 
NAAQS, then the State has authority to do so. The Center states that 
Part C, Part D, and title V do not say that states must independently 
attain and maintain the NAAQS. The Center concludes by saying that 
Colorado has failed to attain the ozone NAAQS five times and that EPA 
cannot promise to address the State's lack of authority to regulate 
non-major agriculture sources tomorrow, during review of the State's 
nonattainment SIP, when it is required to address the issue today.
    Response: EPA disagrees with this comment. First, EPA did not waste 
the Tenth Circuit's or the Center's time, nor did EPA say the exact 
same thing on remand as EPA said before remand, as the Center contends. 
Rather, when EPA sought voluntary remand, the Agency specifically said 
that ``EPA intends to review its analysis of the State Authority 
Element and may provide additional explanation of its reading of 
Colorado's agriculture provision.'' \67\ On remand, EPA has done 
exactly that--because of concerns raised about the State's authority, 
EPA reevaluated C.R.S. 25-7-109(8)(a) (``agriculture provision'') and 
verified our reading of that provision with Colorado. By letter, 
Colorado explained the State's authority under the agriculture 
provision, which confirmed EPA's earlier interpretation of the 
provision. By verifying our interpretation with Colorado, EPA received 
adequate necessary assurances from the State concerning Colorado's 
legal authority, as required by CAA section 110(a)(2)(E)(i).
---------------------------------------------------------------------------

    \67\ Center for Biological Diversity v. EPA, No. 20-9560 (Tenth 
Cir.), EPA's Motion for Voluntary Remand at 10.
---------------------------------------------------------------------------

    Second, the Center's interpretation of the agriculture provision is 
wrong. A plain reading of the provision, supported by Colorado's 
letter,

[[Page 61258]]

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demonstrates that Colorado does have authority to:

--Apply reasonably available control technology (RACT) to agricultural 
facilities;
--Regulate agricultural facility emissions to protect visibility;
--Regulate agricultural, horticultural, or floricultural production 
sources, even if they are not major sources; and
--Regulate minor sources like pesticides, farms, CAFOs, and fugitive 
emissions if required by Part C, Part D, or title V of the 
CAA.68
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    \68\ C.R.S. 25-7-109(8)(a).

Part C, Part D, and title V of the CAA do not prescribe specific 
measures that states must adopt. Rather, ``the CAA supplies the goals 
and basic requirements of state implementation plans, but the states 
have broad authority to determine the methods and particular control 
strategies they will use to achieve the statutory requirements.'' \69\ 
Part C requires that states submit to EPA SIP submissions that contain 
``emission limitations and such other measures as may be necessary . . 
. to prevent significant deterioration of air quality in each region 
(or portion thereof) designated . . . as attainment or 
unclassifiable;'' \70\ and SIP submissions that contain ``emission 
limits, schedules of compliance and other measures as may be necessary 
to make reasonable progress toward meeting the national [visibility] 
goal.'' \71\ Further, Part D of the CAA requires that SIPs ``provide 
for the implementation of all reasonably available control measures as 
expeditiously as practicable (including such reductions in emissions 
from existing sources in this area as may be obtained through the 
adoption, at a minimum of reasonably available control technology) and 
shall provide for attainment of the national primary ambient air 
quality standards;'' \72\ ``additional measures, if any, as may be 
necessary to ensure [ ] maintenance'' of the NAAQS once a nonattainment 
area has been redesignated to attainment; \73\ ``[RACT] corrections'' 
for areas deemed Marginal nonattainment \74\ and further SIP revisions 
for areas deemed Moderate, Serious, Severe, and Extreme 
nonattainment.\75\ While some of the SIP requirements apply only to 
major sources, other provisions require states to evaluate additional 
area sources of emissions.\76\
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    \69\ BCCA Appeal Group v. EPA, 355 F.3d 817, 822 (5th Cir. 2003) 
(citing Union Elec. Co. v. EPA, 427 U.S. 246, 266 (1976)).
    \70\ 42 U.S.C. 7471.
    \71\ 42 U.S.C. 7491(b)(2).
    \72\ 42 U.S.C. 7502(c)(1); see also 7511a(2)(A) (requiring RACT 
corrections for marginal areas).
    \73\ 42 U.S.C. 7505(a).
    \74\ 42 U.S.C. 7511a(a)(2).
    \75\ 42 U.S.C. 7511a(b), (c), (d), and (e).
    \76\ Compare, e.g., 42 U.S.C. 7502(c)(5) with 7502(c)(6). See 
also 40 CFR 51.308(f)(2)(i) (instructing the states to ``consider 
evaluating major and minor stationary sources or groups of sources, 
mobile sources, and area sources'' as part of their long term 
strategies for addressing visibility impairment).
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    Thus, if Colorado needs to regulate agricultural sources 
(regardless of size) in order to attain and maintain the NAAQS or to 
protect visibility as required by federal law in the CAA, Colorado has 
the authority under state law to include such measures in its SIP 
submissions under Part C and Part D of the CAA. Further, EPA separately 
evaluates the sufficiency of each of these submissions under the 
relevant statutory and regulatory provisions.\77\ If EPA deems such SIP 
submissions inadequate to prevent significant deterioration, protect 
visibility, or attain and maintain the NAAQS, Colorado may be required 
by Part C or Part D of the CAA to regulate agricultural sources 
(regardless of size) and is not prohibited by C.R.S. 25-7-109(8)(a) 
from doing so. EPA interprets C.R.S. 25-7-109(8)(a) to authorize such 
regulation if required for these purposes, and the State has confirmed 
this reading of state law. Moreover, each time the State develops a SIP 
submission and EPA proposes action on a SIP submission, the Center has 
an opportunity to comment on the SIP submission during both the state 
and federal public comment periods.\78\ Those are the appropriate 
opportunities for the Center to make their arguments regarding the need 
for better regulation of agricultural sources. For example, to the 
extent that the Center advocates for control of pesticide emissions as 
VOC precursors to ozone formation in a given nonattainment area, a 
proper place for such advocacy is during the State's development of a 
nonattainment SIP submission and EPA's evaluation of it. Here, in the 
context of EPA's evaluation of Colorado's infrastructure SIP 
submission, the question is whether Colorado has provided necessary 
assurances of the State's authority to do so in order to implement its 
SIP.
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    \77\ See, e.g., 42 U.S.C. 7410(k)(3); 7502(d). See also Letter 
to Deb Thomas, Regional Administrator (Acting) and Deputy Regional 
Administrator, U.S. Environmental Protection Agency, Region 8, from 
Garrison Kaufman, Director, Air Pollution Control Division, July 29, 
2021 ([T]he DMFR ozone area is a nonattainment area and, therefore, 
the AQCC has the authority to regulate emissions from agricultural 
production to the extent that such regulations are required by Part 
D of the federal Clean Air Act due to the DMNFR ozone area's 
nonattainment status.''); 84 FR 36516, 36518 (July 29, 2019) 
(explaining that Colorado's infrastructure SIP submission met the 
``basic infrastructure requirements'' of CAA section 110(a)(2)(A) 
but that whether the State's measures meet the requirements of CAA 
part D is a separate determination that EPA would make in an action 
reviewing the measures under part D.).
    \78\ See, e.g., 84 FR 34083 (July 17, 2019) (proposing to 
Colorado's visibility progress report for the first regional haze 
implementation period); 86 FR 11129 (February 24, 2021).
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    Third, the Center takes issue with part of Colorado's letter, 
asserting that Colorado states that it regulates agricultural sources 
through minor source permitting, and asserting that Colorado has never 
issued a minor source air permit for a farm or CAFO and that EPA has 
not provided evidence to the contrary. The Center misconstrues the 
letter. Colorado does not state that the State regulates all 
agricultural sources through minor source permitting; rather, Colorado 
states that it regulates ``agricultural sources that are subject to [a 
New Source Performance Standard (NSPS)]'' through the minor source 
permitting program, the PSD and NSR permitting programs, and the title 
V permitting program.\79\ Additionally, in reviewing Colorado's 
infrastructure SIP submission under CAA section 110(a)(2)(E)(i), the 
question is not whether Colorado has regulated or does regulate 
agricultural sources; the question is whether Colorado has the 
authority to do so if necessary.\80\
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    \79\ Letter to Deb Thomas, Regional Administrator (Acting) and 
Deputy Regional Administrator, U.S. Environmental Protection Agency, 
Region 8, from Garrison Kaufman, Director, Air Pollution Control 
Division, July 29, 2021.
    \80\ 42 U.S.C. 7410(a)(2)(E)(i); 40 CFR 51.230-231; Stephen D. 
Page, EPA Office of Air Quality Planning and Standards, Guidance on 
Infrastructure State Implementation Plan (SIP) Elements under Clean 
Air Act Sections 110(a)(1) and 110(a)(2), 41 (2013).
---------------------------------------------------------------------------

    The fact that the agriculture provision does not specifically 
mention minor source permitting does not mean that Colorado lacks the 
authority to regulate minor agricultural sources. Like all states, 
Colorado is required to include in its SIP a minor source NSR program 
governed by Parts C and D of the CAA.\81\ Colorado's minor source NSR 
program is contained in Colorado's ``Regulation 3.'' \82\ Colorado may 
amend Regulation 3 as necessary to assure NAAQS are achieved as 
required by Parts C and D of the CAA. Thus, Colorado has authority to 
regulate minor agricultural sources as necessary under Parts C and D of 
the CAA.
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    \81\ See 42 U.S.C. 7410(a)(2)(C) (requiring SIPs to contain a 
program for ``regulation of the modification and construction of any 
stationary source within areas covered by the plan as necessary to 
assure that [NAAQS] are achieved, including a permit program as 
required by parts C and D of this subchapter''); 40 CFR 51.160 
(requirements for permit programs in SIPs generally) (both 
implicitly including minor sources).
    \82\ C.R.S. 25-7-114 to 25-7-114.7.

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[[Page 61259]]

    Fourth, with respect to the Center's assertion that there is no 
NSPS for CAFOs, that does not mean that Colorado cannot regulate CAFO 
emissions under the CAA. As explained above, Colorado could include 
measures in its nonattainment and visibility SIP submissions designed 
to reduce emissions from CAFOs. The agriculture provision does not bar 
the State from doing so if necessary, under the CAA.
    Finally, the Center raises issues that are outside the scope of 
this rulemaking. EPA sought, and the Tenth Circuit granted, remand of 
only two portions of EPA's approval of Colorado's infrastructure SIP 
submission for the 2015 ozone standards--EPA's conclusions under CAA 
section 110(a)(2)(D)(i)(I) and (E)(i) with respect to the agriculture 
provision. EPA proposed action on these two portions only and stated 
that the Agency was not reopening for comment any other portions of the 
2020 final rule.\83\ Accordingly, the Center's assertion that EPA has 
not acted on a petition to promulgate an NSPS for CAFOs is outside the 
scope of this action. Similarly, the Center's assertions that EPA must 
disapprove Colorado's infrastructure SIP under CAA section 
110(a)(2)(A), 110(a)(2)(D)(i)(II) (prong 4), and 110(a)(2)(J) are also 
outside the scope of this action.\84\
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    \83\ 87 FR 27054.
    \84\ See 85 FR 20165, 20171 (April 10, 2020) (explaining EPA's 
basis for approving Colorado's infrastructure SIP submission under 
CAA section 110(a)(2)(D)(i)(II) (prong 4) and 110(a)(2)(J)); 85 FR 
36518 (explaining EPA's basis for proposing to approve Colorado's 
infrastructure SIP submission under CAA section 110(a)(2)(A)).
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    EPA notes that ``Congress has left to the Administrator's sound 
discretion determination of what assurances are `necessary' '' under 
CAA section 110(a)(2)(E)(i).\85\ For the foregoing reasons, and for the 
reasons stated in our proposal, we conclude that Colorado's 
infrastructure SIP submission, supported by Colorado's letter regarding 
the agriculture provision, provides the necessary assurances of the 
State's authority to carry out Colorado's SIP for the 2015 ozone NAAQS 
as required by CAA section 110(a)(2)(E)(i).
---------------------------------------------------------------------------

    \85\ NRDC v. EPA, 478 F.2d 875, 884 (1st Cir. 1973); see also 
BCCA, 355 F.3d at 844-847.
---------------------------------------------------------------------------

III. Final Action

    EPA is confirming our approval that the good neighbor portion of 
Colorado's infrastructure SIP satisfies the interstate transport 
provision of the CAA, section 110(a)(2)(D)(i)(I), for the 2015 ozone 
NAAQS, and that the State has provided the necessary assurances of the 
State's authority to regulate all agricultural sources as may be 
required by the CAA under section 110(a)(2)(E)(i).

IV. Statutory and Executive Order Reviews

    Under the CAA, 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 CAA. 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 affect small governments, 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 CAA; 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 CAA, petitions for judicial review 
of this action must be filed in the United States Court of Appeals for 
the appropriate circuit by December 12, 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, 
Greenhouse gases, Incorporation by reference, Nitrogen dioxide, Ozone, 
Reporting and recordkeeping requirements, Volatile organic compounds.

    Dated: October 2, 2022.
KC Becker,
Regional Administrator, Region 8.
[FR Doc. 2022-21815 Filed 10-7-22; 8:45 am]
BILLING CODE 6560-50-P


