Air Plan Approval; Colorado; 2017 Base Year Inventory and Emission Statement Rule Marginal Nonattainment Requirements, Revisions to Regulation 3, 25216-25223 [2024-07584]
Download as PDF
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Federal Register / Vol. 89, No. 70 / Wednesday, April 10, 2024 / Proposed Rules
2 Additional NO and SO emissions control measures and associated compliance dates for Jim Bridger Units 1–4, are found in § 52.2636(c)
X
2
Tables 3 and 4.
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TABLE 3 TO § 52.2636
[NOX and SO2 Emission Limits for Jim Bridger Units 1–4, Effective January 1, 2022]
Total units 1–4
NOX emission limit
(monthly average
basis) 1 2
(lb/hour)
Month
January ....................................................................................................................................
February ...................................................................................................................................
March .......................................................................................................................................
April ..........................................................................................................................................
May ..........................................................................................................................................
June .........................................................................................................................................
July ...........................................................................................................................................
August ......................................................................................................................................
September ...............................................................................................................................
October ....................................................................................................................................
November ................................................................................................................................
December ................................................................................................................................
Total units 1–4
SO2 emission limit
(monthly average
basis) 1 2
(lb/hour)
2,050
2,050
2,050
2,050
2,200
2,500
2,500
2,500
2,500
2,300
2,030
2,050
2,100
2,100
2,100
2,100
2,100
2,100
2,100
2,100
2,100
2,100
2,100
2,100
1 Effective
January 1, 2022, through December 31, 2023.
addition to monthly NOX and SO2 emission limits, an annual, plant-wide NOX plus SO2 emissions cap of 17,500 tons per year is effective
January 1, 2022, through December 31, 2023.
2 In
TABLE 4 TO § 52.2636
[NOX Emission Limits and Heat Input for Jim Bridger Units 1–2, Effective January 1, 2024]
NOX emission limit
(tons/year)
Unit
Unit 1 .......................................................................................................................................
Unit 2 .......................................................................................................................................
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(d) Compliance date. (1) The owners
and operators of PacifiCorp Jim Bridger
Units 1, 2, 3, and 4 shall comply with
the NOX emission limit of 0.26 lb/
MMBtu and PM emission limit of 0.03
lb/MMBtu and other requirements of
this section by March 4, 2019. The
owners and operators of PacifiCorp Jim
Bridger Units 1 and 2 shall comply with
the NOX emission limit of 0.12 lb/
MMBtu by January 1, 2024. The owners
and operators of PacifiCorp Jim Bridger
Units 3 and 4 shall comply with the
NOX emission limit of 0.07 lb/MMBtu
by: December 31, 2015, for Unit 3, and
December 31, 2016, for Unit 4. The
owners and operators of PacifiCorp Jim
Bridger Units 1, 2, 3, and 4 shall comply
with the NOX and SO2 emission limits
contained in § 52.2636(c) Table 3 by
January 1, 2022. The owners and
operators of PacifiCorp Jim Bridger
Units 1 and 2 shall comply with NOX
emission and heat input limits
contained in § 52.2636(c) Table 4 by
January 1, 2024.
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[FR Doc. 2024–07414 Filed 4–9–24; 8:45 am]
BILLING CODE 6560–50–P
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ENVIRONMENTAL PROTECTION
AGENCY
40 CFR Part 52
[EPA–R08–OAR–2023–0441; FRL–11837–
01–R8]
Air Plan Approval; Colorado; 2017
Base Year Inventory and Emission
Statement Rule Marginal
Nonattainment Requirements,
Revisions to Regulation 3
Environmental Protection
Agency (EPA).
ACTION: Proposed rule.
AGENCY:
The Environmental Protection
Agency (EPA) is proposing to approve
state implementation plan (SIP)
revisions submitted by the State of
Colorado to meet certain Clean Air Act
(CAA) requirements related to the
Denver Metro/North Front Range
(DMNFR) area’s classification as
Marginal nonattainment for the 2015 8hour ozone national ambient air quality
standards (NAAQS). The revisions
contain a base year emissions inventory
for the nonattainment area and certify
that the State’s existing Air Pollutant
SUMMARY:
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1,314
1,314
Heat input
(MMBtu/year)
21,900,000
21,900,000
Emissions Notice (APEN) program
fulfills the CAA’s emission statement
rule requirement. The revisions also
include a new requirement for annual
certification of APEN reported
emissions. Unrelated to Colorado’s
Marginal ozone nonattainment
obligations, EPA is also proposing to
approve the State’s revisions to
Regulation 3 concerning an update to
the date of incorporation by reference of
global warming potentials used in the
computation of the carbon dioxide
equivalent for comparing emissions
from various greenhouse gases (GHGs).
EPA is taking this action pursuant to the
CAA.
DATES: Written comments must be
received on or before May 10, 2024.
ADDRESSES: Submit your comments,
identified by Docket ID No. EPA–R08–
OAR–2023–0441, to the Federal
Rulemaking Portal: https://
www.regulations.gov. Follow the online
instructions for submitting comments.
Once submitted, comments cannot be
edited or removed from
www.regulations.gov. The EPA may
publish any comment received to its
public docket. Do not submit
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electronically any information you
consider to be Confidential Business
Information (CBI) or other information
whose disclosure is restricted by statute.
Multimedia submissions (audio, video,
etc.) must be accompanied by a written
comment. The written comment is
considered the official comment and
should include discussion of all points
you wish to make. The EPA will
generally not consider comments or
comment contents located outside of the
primary submission (i.e., on the web,
cloud, or other file sharing system). For
additional submission methods, the full
EPA public comment policy,
information about CBI or multimedia
submissions, and general guidance on
making effective comments, please visit
https://www2.epa.gov/dockets/
commenting-epa-dockets.
Docket: All documents in the docket
are listed in the www.regulations.gov
index. Although listed in the index,
some information is not publicly
available, e.g., CBI or other information
whose disclosure is restricted by statute.
Certain other material, such as
copyrighted material, will be publicly
available only in hard copy. Publicly
available docket materials are available
electronically in www.regulations.gov.
To reduce the risk of COVID–19
transmission, for this action we do not
plan to offer hard copy review of the
docket. Please email or call the person
listed in the FOR FURTHER INFORMATION
CONTACT section if you need to make
alternative arrangements for access to
the docket.
FOR FURTHER INFORMATION CONTACT:
Matthew Lang, Air and Radiation
Division, EPA, Region 8, Mailcode
8ARD–IO, 1595 Wynkoop Street,
Denver, Colorado 80202–1129, (303)
312–6709, lang.matthew@epa.gov.
SUPPLEMENTARY INFORMATION:
Throughout this document wherever
‘‘we,’’ ‘‘us,’’ or ‘‘our’’ is used, we mean
the EPA.
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Table of Contents
I. Background
II. The EPA’s Evaluation of Colorado’s SIP
Submittals
A. Base Year Emissions Inventory
1. Point Source Emissions
2. Nonpoint Source Emissions
3. On-Road Mobile Source Emissions
4. Nonroad Mobile Source Emissions
5. Oil and Gas Emissions
6. Biogenic Emissions
7. EPA’s Evaluation of the Base Year
Emissions Inventory
B. Certification of Existing Emission
Statement Rule and Addition of Annual
Certification Requirement
C. Other Revisions to Regulation 3, Part A
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1. Regulation 3, Part A, Sections I.B.10 and
1.B.44.b.(i)—Date of Incorporation by
Reference of Global Warming Potentials
2. Regulation 3, Part A, Section
I.B.44.(b).(i)—Computation of Mass of
Carbon Dioxide Equivalent
III. Proposed Action
IV. Incorporation by Reference
V. Statutory and Executive Order Reviews
I. Background
EPA determined decades ago that
ground-level ozone endangers public
health and welfare. Ground-level ozone
forms when nitrogen oxides (NOX) and
volatile organic compounds (VOC) react
in the presence of sunlight. Referred to
as ozone precursors, these two
pollutants are emitted by many types of
pollution sources, including motor
vehicles, power plants, industrial
facilities, and nonpoint 1 sources.
Scientific evidence indicates that
adverse human health effects occur
following exposure to ozone. These
effects are more pronounced in children
and adults with lung disease. Breathing
air containing ozone can reduce lung
function and inflame airways, which
can increase respiratory symptoms and
aggravate asthma or other lung diseases.
In 1979, in response to this scientific
evidence, EPA promulgated the first
ozone NAAQS, the 0.12 parts per
million (ppm) 1-hour ozone NAAQS.2
EPA has strengthened the ozone
NAAQS over the years. In 1997, EPA
promulgated a revised ozone NAAQS of
0.08 ppm, averaged over eight hours,
which it determined was more
protective of public health than the
1979 standard.3 In 2008, EPA revised
the 8-hour ozone NAAQS from 0.08 to
0.075 ppm.4 In 2015, the Agency further
strengthened the 8-hour ozone NAAQS
to 0.070 ppm.5
The DMNFR area is in nonattainment
status for both the 2008 and the 2015
ozone NAAQS. It is currently classified
as a Severe nonattainment area under
the 2008 standard,6 which is not at issue
in this rulemaking. Effective August 3,
2018, EPA designated the DMNFR area
as Marginal nonattainment for the more
stringent 2015 ozone NAAQS (2015
DMNFR Nonattainment Area).7 The
2015 DMNFR Nonattainment Area
includes Adams, Arapahoe, Boulder,
Broomfield, Denver, Douglas, Jefferson,
and Weld counties as well as a portion
1 Nonpoint sources are also sometimes referred to
as area sources.
2 44 FR 8202 (Feb. 8, 1979).
3 62 FR 38856 (July 18, 1997).
4 73 FR 16436 (Mar. 27, 2008).
5 80 FR 65292 (Oct. 26, 2015).
6 40 CFR 81.306; 87 FR 60926, 60933 (Oct. 7,
2022).
7 83 FR 25776, 25792 (June 4, 2018).
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of Larimer County.8 While EPA has
since reclassified the 2015 DMNFR
Nonattainment Area as Moderate for
failing to attain the 2015 ozone NAAQS
by the area’s Marginal attainment date,9
Colorado must still meet the CAA
requirements applicable to Marginal
ozone nonattainment areas.
This proposed rule addresses only the
base year inventory and emission
statement rule requirements related to
the Marginal nonattainment
classification, as described further
below, including SIP revisions to
address EPA’s revised designation
incorporating all of Weld County into
the nonattainment area.10 Requirements
stemming from the DMNFR
Nonattainment Area’s Moderate
nonattainment classification for the
2015 ozone NAAQS and the Severe
classification for the 2008 ozone
NAAQS will be addressed in separate
EPA rulemakings.
The CAA and its implementing
regulations—in particular, the 2015
ozone NAAQS SIP Requirements
Rule,11 codified at 40 CFR part 51,
subpart CC—establish several
requirements for ozone nonattainment
areas. Section 172(c)(3) of the CAA,
which applies generally to states with
areas classified as nonattainment for any
NAAQS, requires submission of
comprehensive, accurate, and current
inventories of actual emissions from all
sources of relevant pollutants in
Marginal nonattainment areas.12
Specific to areas classified as Marginal
ozone nonattainment, section 182(a)(1)
requires states to submit a base year
inventory of ozone precursors (NOX and
VOC) within two years of the
nonattainment designation.13 Section
182(a)(3)(B) directs states to implement
an emission statement rule requiring
certain stationary sources to report their
emissions of NOX and VOC.14
8 As detailed in this proposed rule, EPA initially
excluded part of Weld County from the 2015
DMNFR Nonattainment Area, but, in response to a
court decision, subsequently expanded its air
quality designation to include all of Weld County.
9 40 CFR 81.306; 87 FR 60897, 60916 (Oct. 7,
2022).
10 See 86 FR 67864, 67869 (Nov. 30, 2021) (noting
that states affected by the revised air quality
designations would ‘‘work with their respective
EPA Regional office to submit any necessary
supplements or revisions to fulfill the Marginal area
SIP revision requirements associated with the
nonattainment boundaries in this final action as
expeditiously as practicable’’).
11 83 FR 62998 (Dec. 6, 2018). The SIP
Requirements Rule established implementation
requirements for the 2015 ozone NAAQS, including
requirements for base year emissions inventories.
12 42 U.S.C. 7502(c)(3).
13 42 U.S.C. 7511a(a)(1); 40 CFR 51.1315(a); 40
CFR 51.1300(p) (defining ‘‘base year inventory’’).
14 42 U.S.C. 7511a(a)(3)(B).
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Emissions inventories and emission
statements provide data that inform a
variety of air quality planning tasks.
States use emissions inventories to
establish baseline emissions levels,
calculate emissions reduction targets
needed to attain the NAAQS, determine
emissions inputs for ozone air quality
modeling analyses, and track emissions
over time to determine progress toward
achieving air quality and emissions
reduction goals. EPA has issued
guidance to assist states in developing
their emission inventories; states retain
the discretion to adopt approaches on a
case-by-case basis that differ from that
guidance where appropriate.15 Emission
statements provide important
information that states may use to
develop emissions inventories for air
quality planning, to support permitting
efforts, and to assist in demonstrating
source compliance.16
On July 27, 2020, through the
Colorado Department of Public Health
and Environment (CDPHE), Colorado
submitted a SIP revision titled ‘‘2015
Ozone National Ambient Air Quality
Standard (NAAQS)—Denver Metro/
North Front Range Marginal
Nonattainment Area Requirements’’
(2020 SIP Submittal) to satisfy, in part,
the emissions inventory requirements
under CAA sections 172(c)(3) and
182(a)(1) and the emission statement
requirement of CAA section
182(a)(3)(B).17 Colorado met the CAA’s
reasonable notice and public hearing
requirements 18 for the 2020 SIP
Submittal through notice in the Denver
Legal Post on May 23, 2020, and a
public hearing on June 18, 2020.19
However, before EPA proposed action
on the 2020 SIP Submittal, the 2015
DMNFR Nonattainment Area boundary,
and specifically the partial
nonattainment designation of Weld
County, was remanded without vacatur
in Clean Wisconsin v. EPA, 964 F.3d
1145 (D.C. Cir. 2020). EPA then issued
a revised designation to include the
whole of Weld County in the
nonattainment area and noted that states
should work with their respective EPA
15 U.S. EPA, ‘‘Emissions Inventory Guidance for
Implementation of Ozone and Particulate Matter
National Ambient Air Quality Standards (NAAQS)
and Regional Haze Regulations,’’ EPA–454/B–17–
002 (May 2017), 1 (2017 Emissions Inventory
Guidance).
16 U.S. EPA, ‘‘Draft Guidance on the
Implementation of an Emission Statement Program’’
(July 1992), 1.
17 2020 SIP Submittal, ‘‘01-Submittal Letter to
EPA.’’ The letter is dated July 6, 2020, but the SIP
was submitted to EPA on July 27, 2020. The 2020
SIP Submittal was deemed complete by operation
of law six months after submission.
18 42 U.S.C. 7410(a)(1), (l); 40 CFR 51.102.
19 2020 SIP Submittal, ‘‘03-Denver Post Legal Ad’’
and ‘‘04-Meeting Agenda.’’
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regional office to submit any necessary
supplements or revisions to fulfill
Marginal area SIP requirements.20
In response, on June 26, 2023, CDPHE
submitted a SIP revision titled ‘‘Ozone
State Implementation Plan (SIP) and
Associated Regulations: Regulation
Number 3, Regulation Number 7,
Regulation Number 21, Common
Provisions, and Air Quality Standards,
Designations, and Emissions Budgets’’
(2023 SIP Submittal).21 Among other
components,22 the 2023 SIP Submittal
includes rule revisions to address the
outstanding Marginal area SIP
requirements for the 2015 DMNFR
Nonattainment Area, including an
updated base year inventory reflecting
EPA’s revised boundary designation of
the 2015 DMNFR Nonattainment Area.
Colorado met the CAA’s reasonable
notice and public hearing requirements
through notice in the Denver Legal Post
on September 17, 2022, and a public
hearing on December 13–16, 2022.23
Finally, for purposes of administrative
efficiency, EPA is proposing to act on
Colorado SIP revisions unrelated to the
State’s Marginal ozone nonattainment
obligations. On March 22, 2021, CDPHE
submitted a SIP revision (‘‘2021 SIP
Submittal’’) that included revisions to
Regulation 3, Part A to update the date
of incorporation by reference of global
warming potentials (GWPs) as defined
in 40 CFR part 98, subpart A, table A–
1.24 Colorado met the CAA’s reasonable
notice and public hearing requirements
through notice in the Denver Legal Post
on September 26, 2020, and a public
hearing on December 16–18, 2020.25
Although EPA approved other elements
of the 2021 SIP Submittal in a March 27,
2023 final rule, we did not finalize
action on the revisions updating the
date of incorporation by reference of
GWPs for the reasons discussed in that
final rule 26 and below. In addition,
20 86 FR 67864, 67869. The revised designation
was affirmed in Board of County Commissioners of
Weld County, Colorado v. EPA, 72 F.4th 284, 289–
92 (D.C. Cir. 2023).
21 2023 SIP Submittal, Document Set 1 of 7, ‘‘00_
Submittal Letter to EPA_Ozone SIP.’’ The letter is
dated June 22, 2023, but the SIP was submitted to
EPA on June 26, 2023. EPA determined the 2023
SIP Submittal to be complete on September 7, 2023.
22 The 2023 SIP Submittal includes elements of
Colorado’s 2008 Severe Ozone SIP and its 2015
Moderate Ozone SIP. EPA will take action on those
SIP components in a separate rulemaking.
23 2023 SIP Submittal, Document Set 1 of 7, ‘‘05_
Denver Post Legal Ad’’ and ‘‘06_Meeting Agenda.’’
24 2021 SIP Submittal, Document Set 1 of 6, ‘‘01_
Submittal Letter to EPA—121820_Ozone SIP, Reg 3,
Reg 7, Air Quality Stds_signed’’; ‘‘03_Hearing
Notice & Proposed Language_R3.’’ The 2021 SIP
Submittal was deemed complete by operation of
law six months after submission.
25 2021 SIP Submittal, Document Set 1 of 6, ‘‘05_
Denver Post Legal Ad’’ and ‘‘06_Meeting Agenda.’’
26 88 FR 18054, 18054 (Mar. 27, 2023).
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Colorado’s 2023 SIP Submittal included
revisions to Regulation 3 related to the
incorporation by reference of GWPs that
build upon the aforementioned 2021 SIP
Submittal revisions. We now propose to
act concurrently on the Regulation 3
GWP revisions from both the 2021 SIP
Submittal and subsequent 2023 SIP
Submittal.
II. The EPA’s Evaluation of Colorado’s
SIP Submittals
A. Base Year Emissions Inventory
Under CAA sections 172(c)(3) and
182(a)(1), Colorado must submit a
comprehensive, accurate, and current
accounting of actual emissions of ozone
precursors from all sources (point,
nonpoint, nonroad mobile, and on-road
mobile sources) in the 2015 DMNFR
Nonattainment Area. EPA’s SIP
Requirements Rule specifies that the
inventory year shall be selected
consistent with the baseline year for the
Reasonable Further Progress (RFP) plan
under 40 CFR 51.1310(b),27 which EPA
identified as 2017.28 The rule also
requires states to report ‘‘ozone season
day emissions’’ in the base year
inventory,29 as described in other EPA
regulations:
Ozone season day emissions means an
average day’s emissions for a typical ozone
season work weekday. The state shall select,
subject to EPA approval, the particular
month(s) in the ozone season and the day(s)
in the work week to be represented,
considering the conditions assumed in the
development of RFP plans and/or emissions
budgets for transportation conformity.30
Based on EPA’s 2017 Emissions
Inventory Guidance for Implementation
of Ozone and Particulate Matter
National Ambient Air Quality Standards
(NAAQS) and Regional Haze
Regulations (2017 Emissions Inventory
Guidance), the selected ozone season
day should be representative of the
conditions leading to nonattainment.31
To satisfy these requirements,
Colorado included a 2017 base year
inventory in its 2020 SIP Submittal.32
Following EPA’s revised designation of
the 2015 DMNFR Nonattainment Area,
Colorado then submitted a revised base
year inventory in its 2023 SIP Submittal
as a superseding supplement to its 2020
SIP Submittal to account for emissions
from the revised nonattainment area,
including the whole of Weld County.33
27 40
CFR 51.1315(a).
FR 62998, 63005.
29 40 CFR 51.1315(c).
30 40 CFR 51.1300(q).
31 2017 Emissions Inventory Guidance, 75.
32 2020 SIP Submittal, ‘‘08-Denver 2017 Ozone
NAA Inventory.’’
33 2023 SIP Submittal, Document Set 6 of 7, ‘‘2017
Baseline Inventory Update TSD FINAL,’’ 1–2
28 83
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Consistent with the SIP Requirements
Rule, the revised inventory uses 2017 as
the base year for SIP planning
purposes.34 It was developed for a
typical July day in 2017 to estimate NOX
and VOC emissions during the peak
summer ozone season, which is
representative of the conditions leading
to nonattainment in the 2015 DMNFR
Nonattainment Area.35 Consistent with
the 2017 Emissions Inventory Guidance,
the inventory estimates emissions from
all major source categories including
point sources, nonpoint sources, onroad and nonroad mobile sources, and
biogenic sources.36 Additional
information describing Colorado’s
general methodology for compiling its
emissions inventory may be found in
the State’s inventory technical support
document included in the 2023 SIP
Submittal.37
Tables 1 and 2 of this proposed rule
show 2017 ozone season day emissions
for the 2015 DMNFR Nonattainment
Area in units of tons per day (tpd).
Table 1 summarizes anthropogenic VOC
and NOX emissions by source sector.
Table 2 summarizes biogenic VOC and
NOX emissions, including those from
fire and other naturally occuring
emissions not included as
anthropogenic emissions in Table 1. The
anthropogenic portion of the base year
inventory for a nonattainment area may
serve as the Rate of Progress (ROP)/RFP
baseline inventory for Moderate and
higher nonattainment classifications.38
The following sections II.A.1–II.A.6
describe the State’s inventory of
emissions from the various source
sectors in more detail.
TABLE 1—DENVER METRO/NORTH
FRONT RANGE NONATTAINMENT
AREA 2017 VOC AND NOX BASE
YEAR ANTHROPOGENIC EMISSIONS
INVENTORY
[Tons/Day] 39
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Source type
NOX
VOC
Point ............................................
Nonpoint ......................................
On-road Mobile ...........................
Nonroad Mobile ...........................
Oil & Gas .....................................
24.2
0.1
57.4
42.9
78.2
21.9
80.1
48.1
44.5
211.1
Total .....................................
202.9
405.7
(‘‘2017 Baseline Inventory Update TSD’’); 2023 SIP
Submittal, Document Set 6 of 7, ‘‘APCD_FINAL_
SIP–2015,’’ ch. 3 (‘‘Revised Milestone Emission
Inventory’’).
34 83 FR 62998, 63005, 63011 n.29.
35 2017 Baseline Inventory Update TSD, 2.
36 Id.; Revised Milestone Emission Inventory, ch.
3; 2017 Emissions Inventory Guidance, 19, 81.
37 2017 Baseline Inventory Update TSD, 1–14.
38 2017 Emissions Inventory Guidance, 41.
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TABLE 2—DENVER METRO/NORTH
FRONT RANGE NONATTAINMENT
AREA 2017 VOC AND NOX BASE
YEAR BIOGENIC EMISSIONS
[Tons/Day] 40
Source type
NOX
Biogenic .......................................
26.5
VOC
419.0
1. Point Source Emissions
Point sources are large, stationary,
identifiable sources of emissions that
release pollutants into the atmosphere.
In its 2017 base year inventory, the State
included point source emissions from
source categories including power
plants/electric generating units, external
combustion boilers, industrial
processes, internal combustion sources,
petroleum/solvent evaporation not
associated with the oil and gas industry,
and waste disposal.41 The SIP
Requirements Rule provides that
emissions from point sources shall be
reported according to the thresholds of
EPA’s Air Emissions Reporting
Requirements (AERR).42 The 2017
Emissions Inventory Guidance directs
those preparing point source inventories
to volume 2 of the Emissions Inventory
Improvement Program technical report
series for information on point source
inventory methodology.43 This resource
describes the three principal methods
for estimating point source emissions as
source testing, mass balance
calculations, and emission factors, with
a fourth method utilizing engineering
calculations if the principal methods are
not possible.44
Colorado obtained its point source
data from the APEN database, the State’s
emissions reporting system for
stationary sources.45 Colorado requires
an APEN to be filed for emission points
in a nonattainment area with
uncontrolled actual emissions of one
ton per year or more of any criteria
pollutant that the area is designated
nonattainment for.46 In order of
preferred methodology, APEN emission
estimates are based on actual test data
or, in the absence of such data, on mass
balance calculations, published
39 Revised Milestone Emission Inventory, 3.2.2.1,
tbl. 7.
40 Id. at 3.2.2.7, tbl. 15.
41 Colorado’s methodology and results for the
point source category are described in section
3.2.2.3 of the Revised Milestone Emission
Inventory.
42 40 CFR 51.1315(d).
43 2017 Emissions Inventory Guidance, 81–82.
44 U.S. EPA, EIIP Technical Report Series Vol. II,
Ch. 1: ‘‘Introduction to Stationary Point Source
Emission Inventory Development’’ (May 2001), 1.4–
1—1.4–3.
45 Revised Milestone Emission Inventory, 3.2.2.3.
46 5 CCR 1001–5:3A.II.B.3.a.
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emission factors, or engineering
calculations.47 Since Colorado’s base
year inventory is consistent with the
reporting thresholds in the AERR and
uses methods for estimating emissions
recommended by EPA guidance, the
base year inventory adequately
addresses emissions from the point
source category.
2. Nonpoint Source Emissions
Nonpoint sources are sources of
pollution that are small and numerous
and that have not been inventoried as
specific point sources or mobile sources.
They include a wide range of categories
such as coatings, household and
personal care products, pesticides,
automotive aftermarket products, and
sealants. Inventorying nonpoint sources
involves grouping them by category and
estimating their emissions collectively
using one methodology.
The State developed the nonpoint
source emissions inventory 48 from the
2016v2 EPA modeling platform,49
which includes emission inventories for
2016 and 2023. To establish emissions
for 2017 from the 2016v2 platform, the
State used a linear interpolation from
2016 to 2023. Because a portion of
Larimer County is not part of the 2015
DMNFR Nonattainment Area, the State
scaled the whole-county emissions by
the ratio of the county population
residing within the nonattainment area
boundary based on 2020 census block
data—0.9776—to determine an accurate
emissions contribution for the relevant
part of Larimer County. The nonpoint
source portion of Colorado’s emissions
inventory includes source categories
addressed in the nonpoint portion of the
inventories developed for EPA’s 2016v2
platform. Colorado used EPA estimates
for the nonpoint source category and
apportioned partial county emissions
using methods consistent with the 2017
Emissions Inventory Guidance.50
47 5
CCR 1001–5:3A.II.B.1.
methodology and results for the
nonpoint source category are described in section
3.2.2.4 of the Revised Milestone Emission
Inventory.
49 The 2016v2 modeling platform includes a set
of emissions inventories, data files, software tools,
and scripts used for air quality modeling. Files and
technical support documents are available at:
https://www.epa.gov/air-emissions-modeling/
2016v2-platform. The 2016v2 modeling platform
draws on data from the 2017 National Emissions
Inventory and includes point sources, nonpoint
sources, commercial marine vessels, on-road and
nonroad mobile sources, and fires for the U.S.,
Canada, and Mexico. U.S. EPA, ‘‘Technical Support
Document (TSD): Preparation of Emissions
Inventories for the 2016v2 North American
Emissions Modeling Platform,’’ EPA–454/B–22–001
(Feb. 2022), 1–2.
50 2017 Emissions Inventory Guidance, 72–73,
131–32.
48 Colorado’s
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Therefore, the base year inventory
adequately addresses emissions from
the nonpoint source category.
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3. On-Road Mobile Source Emissions
For on-road mobile sources (vehicles
operated on public roadways),
Colorado’s 2017 base year inventory
includes emissions from passenger cars,
motorcycles, light trucks, refuse/singleunit trucks, short/long-haul trucks, and
buses.51 The State estimated these
emissions using EPA’s Motor Vehicle
Emissions Simulator model version 3
(MOVES3 52) along with link-level
(roadway) vehicle miles traveled (VMT)
provided by the two metropolitan
planning organizations that serve the
2015 DMNFR Nonattainment Area, the
Denver Regional Council of
Governments and the North Front Range
Metropolitan Planning Organization.
The State based VMT on travel demand
model output data from those two
organizations and apportioned it to the
nonattainment area at the roadway level
using Geographic Information Systems.
Additional MOVES3 model inputs
include vehicle population and age
distribution, roadway activity data
(speed and time of day), roadway
classifications (urban, rural, restricted,
unrestricted), fuel properties, inspection
and maintenance program
characteristics, and hourly meteorology.
These model inputs are described in
greater detail in EPA’s MOVES3
technical guidance.53 Specific MOVES3
on-road inputs used by the State are
identified in Appendix A to the 2017
Baseline Inventory Update Technical
Support Document. The State based
model inputs on conditions on an
average July weekday and used the
MOVES3 default fuel formulation. It
calculated NOX and VOC emission
factors from MOVES3 for each vehicle
type and then multiplied these emission
factors by the roadway-level VMT to
establish on-road mobile source
emissions.
Colorado’s on-road mobile source
emissions inventory methodology
follows the SIP Requirements Rule,
which states that ‘‘the latest approved
version of the [MOVES] model should
be used to estimate emissions from on51 Colorado’s methodology and results for the onroad mobile source category are described in
section 3.2.2.6 of the Revised Milestone Emission
Inventory and in section 3.1.1 and Appendix A of
the 2017 Baseline Inventory Update TSD.
52 MOVES3 files and technical support
documents are available at: https://www.epa.gov/
moves/moves-versions-limited-current-use.
53 U.S. EPA, ‘‘MOVES3 Technical Guidance:
Using MOVES to Prepare Emission Inventories for
State Implementation Plans and Transportation
Conformity,’’ EPA–420–B–20–052 (Nov. 2020), 26–
58.
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road and certain nonroad transportation
sources.’’ 54 MOVES3 was the latest
approved version of the model available
at the time that the State developed its
2017 base year inventory. Colorado used
local data on vehicle/roadway activity,
meteorological conditions, fuel use, and
other information characterizing the
DMNFR area in 2017, as called for by
EPA’s 2017 Emissions Inventory
Guidance.55 Therefore, the base year
inventory adequately addresses
emissions from the on-road mobile
source category.
4. Nonroad Mobile Source Emissions
Nonroad mobile sources are mobile
sources other than on-road vehicles,
including engines used in lawn and
garden equipment, commercial and
industrial equipment, construction and
mining equipment, aircraft, and
locomotives. Colorado’s 2017 base year
inventory used EPA’s MOVES-Nonroad
model to estimate emissions from
nonroad mobile sources in the 2015
DMNFR Nonattainment Area, except for
emissions from aviation, locomotives,
and rail yards.56 MOVES-Nonroad exists
as a separate module from the on-road
modeling capabilities within MOVES3.
The specific MOVES3 nonroad inputs
used by the State are identified in
Appendix A to the 2017 Baseline
Inventory Technical Support Document.
The State estimated aviation
emissions based on data provided by
Denver International Airport (DIA) on
fleet composition and activity level,
including estimates of emissions from
aircraft and ground support equipment
such as auxiliary power units. It
estimated 2017 aviation emissions from
other airports within the nonattainment
area using a linear interpolation
between the 2016 and 2023 point source
emissions from the 2016v2 EPA
modeling platform, with DIA emissions
excluded. The State also used the
2016v2 modeling platform to estimate
emissions from railroad locomotives
and rail yard switcher locomotives. It
apportioned line-haul locomotive
activity levels by track mileage in the
nonattainment area. As with the
aviation and nonpoint source sectors,
Colorado determined 2017 locomotive
emissions from a linear trend between
2016 and 2023 estimates from the
2016v2 platform.
FR 62998, 63022.
Emissions Inventory Guidance, 89–90.
56 Colorado’s methodology and results for the
nonroad mobile source category are described in
section 3.2.2.5 of the Revised Milestone Emission
Inventory and in section 3.1.2 and Appendix A of
the 2017 Baseline Inventory Update TSD.
As directed in the SIP Requirements
Rule,57 Colorado used the most recently
available version of EPA’s MOVESNonroad model to estimate emissions
from certain nonroad sources.
Furthermore, Colorado used EPA’s own
2016v2 platform to account for
emissions from aviation, locomotives,
and rail yards not covered by the
MOVES-Nonroad model. Finally, for
emissions specifically from DIA, the
major international airport in the
DMNFR nonattainment area, the State
relied on data provided from the airport
that provides valuable detail regarding
DIA emissions. Therefore, the base year
inventory adequately addresses
emissions from the non-road mobile
source category.
5. Oil and Gas Emissions
To inventory oil and gas emissions for
its 2023 SIP Submittal, Colorado relied
on extensive industry outreach it had
conducted between 2015–2018 to
develop emission inventories for its
2008 8-hour Ozone DMNFR
Nonattainment Area Moderate and
Serious SIPs.58 The State based its
approach to the oil and gas emissions
component of its inventory on actual
and survey data from operators in the
specific geological basin.
Colorado’s 2017 base year emissions
inventory categorizes emissions from
the oil and gas sector into point sources,
condensate/oil tanks, and nonpoint
sources. The State used APEN reported
data to determine emissions from point
sources, including external combustion
boilers, industrial processes, internal
combustion sources, petroleum/solvent
evaporation, and waste disposal. As
described previously, Colorado’s APEN
reporting program meets the point
source thresholds in EPA’s AERR and
uses methods for estimating emissions
consistent with that recommended by
EPA guidance. Therefore, the base year
inventory adequately addresses the
point source component of oil and gas
emissions.
Colorado based condensate tank
emissions (the largest single source of
VOC emissions in the 2017 base year
inventory) on APEN reported data, data
collected by the Colorado Energy and
Carbon Management Commission, and
data reported directly by the industry.
The State developed site-specific
uncontrolled tank emission factors and
multiplied them by facilities’
production in barrels per year. It then
54 83
55 2017
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57 83
FR 62998, 63022.
methodology and results for the oil
and gas source category are described in section
3.2.2.2 of the Revised Milestone Emission Inventory
and in sections 3.2 and 3.3 of the 2017 Baseline
Inventory Update TSD.
58 Colorado’s
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adjusted the resulting emissions to
account for several factors relevant to
condensate tanks: a control device’s
destruction and removal efficiency
(DRE) of emissions; the capture
efficiency of a control device (a
fractional factor intended to discount a
control device’s DRE to account for
actual operating conditions and
potential process/device upsets); and
the rule effectiveness of regulations (a
discount factor that scales a control
device’s DRE downward to account for
a degree of noncompliance with
applicable regulations). Since Colorado
estimated condensate tank emissions
using APEN reported data as well as
additional industry-specific data and
site-specific emission factors, the base
year inventory adequately addresses
emissions from the condensate tank
portion of the oil and gas component.
Oil and gas nonpoint sources in
Colorado’s inventory include emissions
from certain production equipment and
operations (e.g., emissions from well
pad engines, truck loading, pneumatic
devices, fugitives, blowdowns, process
heaters, separator control, and water
tank losses). Nonpoint source emissions
also result from pre-production
operations, including from drill rig
engines, hydraulic fracturing engines,
drilling mud degassing, and venting
during completion operations. The State
estimated some of these emissions based
on facility/equipment level data
reported by 11 producers as part of the
stakeholder group it convened in 2018,
with emissions scaled to account for the
entirety of the 2015 DMNFR
Nonattainment Area including the
whole of Weld County. Colorado used
2017 NEI data to supplement preproduction emissions for categories not
included in producer-submitted data.
The State determined drilling mud
degassing emissions that were not
captured in producer-submitted
information, or the 2017 NEI, from
EPA’s 2016v2 modeling platform by
interpolating emissions to 2017 from
2016 and 2023 emissions. Since
Colorado relied on basin-specific
producer submitted information in
developing its oil and gas nonpoint
source inventory, in addition to
emissions from EPA’s own 2017 NEI
and 2016v2 platform, the base year
inventory adequately addresses
emissions from the oil and gas nonpoint
source component.
6. Biogenic Emissions
Biogenic emissions come from natural
sources. Colorado included a 2017
inventory of biogenic emissions separate
from the anthropogenic portion of the
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inventory.59 The State used EPA’s
Biogenic Emissions Inventory System
(BEIS), version 3, which EPA developed
specifically for estimating biogenic
emissions for inventories.60 Since
Colorado used the BEIS model to
estimate emissions, as recommended by
EPA guidance, the base year inventory
adequately addresses emission from the
biogenic source category.
7. EPA’s Evaluation of the Base Year
Emissions Inventory
Based on EPA’s review and evaluation
of the methodologies, procedures, and
results in Colorado’s 2017 base year
emissions inventory, we propose to find
that the inventory meets the
requirements of CAA sections 172(c)(3)
and 182(a)(1) and the SIP Requirements
Rule. The base year inventory is based
on the most current and accurate
information that was available to the
State at the time the inventory was
developed. Additionally, the 2017
inventory comprehensively addresses
all source categories in the 2015
DMNFR Nonattainment Area including
the whole of Weld County and was
developed consistent with the relevant
EPA emissions inventory regulations,
guidance, and models.
B. Certification of Existing Emission
Statement Rule and Addition of Annual
Certification Requirement
Under CAA section 182(a)(3)(B),
Colorado must implement an emission
statement rule requiring certain
stationary sources that emit VOC or
NOX in the nonattainment area to report
on their emissions at least annually.61
Section 182(a)(3)(B)(ii) specifies that a
state may waive this requirement for
sources that emit less than 25 tpy of
VOC or NOX if the state includes
emissions from such sources in its base
year or periodic inventories.62 If a state
already has an EPA-approved emissions
reporting regulation in place and
determines that it is adequate to meet
the requirements of section 182(a)(3)(B),
EPA may accept a SIP revision with the
state’s written certification of that
determination in lieu of the state
submitting new revised regulations.63 In
its 2020 SIP Submittal, Colorado
certified that its existing SIP-approved
APEN program meets the source
reporting requirements for an emission
59 Colorado’s methodology and results for the
biogenic source category are described in section
3.2.2.7 of the Revised Milestone Emission
Inventory.
60 2017 Emissions Inventory Guidance, 101–102.
61 42 U.S.C. 7511a(a)(3)(B)(i).
62 42 U.S.C. 7511a(a)(3)(B)(ii).
63 83 FR 62998, 63001–02.
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statement rule under CAA section
182(a)(3)(B).64
Colorado’s APEN program requires
stationary sources with uncontrolled
actual emissions of one tpy or more of
any individual criteria pollutant for
which the area is in nonattainment to
file an APEN with the Colorado Air
Pollution Control Division (APCD).65
Emission estimates reported on the
APEN must be based on actual test data
or, in the absence of such data, on an
alternative estimation acceptable to the
APCD.66 Each APEN must include the
location of the source; the operator’s
name and address; the nature of the
facility, process or activity; an estimate
of the quantity and composition of
emissions; and other specified
information that varies based on the
type of source.67 An APEN is valid for
five years 68 but must be revised (1)
annually whenever a significant change
in annual actual emissions occurs or (2)
upon the occurrence of a triggering
event, such as a change in the owner/
operator, the installation of new control
equipment, or the modification of a
permit limitation.69 To ensure the
accuracy of APEN reported emissions
between triggering events, Colorado’s
2023 SIP Submittal includes revisions to
add section II.A.3 to Regulation 3, Part
A.70 The new section II.A.3 requires
stationary sources in the ozone
nonattainment area with the potential to
emit 25 tpy or more of NOX or VOC to
annually certify through an APCDapproved format that annual actual
emissions are as reported on the
source’s APEN.
EPA is proposing to concurrently
approve Colorado’s certification of its
APEN program in its 2020 SIP
Submittal, as well as the State’s
associated addition of the annual
certification provision in section II.A.3
to Regulation 3, Part A in its 2023 SIP
Submittal, as meeting the requirements
for an emission statement rule under
CAA section 182(a)(3)(B). As
recommended by EPA guidance, the
APEN program requires certification of
data accuracy and submission of source
identification information, operating
schedule, emissions information,
control equipment information, and
64 Collectively, the information contained in ‘‘01Submittal Letter to EPA,’’ ‘‘06-Issue Statement,’’
and ‘‘07–CAA Elements Table’’ in the 2020 SIP
Submittal satisfies the certification requirements
outlined in the SIP Requirements Rule, 83 FR
62998, 63001–02.
65 5 CCR 1001–5:3A.II.A.1, II.B.3.a.
66 5 CCR 1001–5:3A.II.B.1.
67 5 CCR 1001–5:3A.II.A.1.
68 5 CCR 1001–5:3A.II.B.2.
69 5 CCR 1001–5:3A.II.C.
70 2023 SIP Submittal, Document Set 5 of 7, ‘‘17_
Reg Lang & SBAP Adopted_R3.’’
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process data.71 Since Colorado’s 2017
base year inventory, as described
previously in this proposed rule,
includes emissions from sources below
25 tpy and is based on acceptable
methodologies, Colorado’s APEN
reporting program satisfies the criteria
for the waiver in CAA section
182(a)(3)(B)(ii). Therefore, EPA proposes
to approve the State’s APEN reporting
program under CAA section
182(a)(3)(B).
C. Other Revisions to Regulation 3,
Part A
EPA is also proposing action on
certain other revisions to Regulation 3
unrelated to the State’s Marginal ozone
nonattainment obligations. Colorado’s
2021 and 2023 SIP Submittals included
several revisions to Regulation 3, Parts
A, B, and D. In this rulemaking, we are
proposing action on the State’s revisions
to Regulation 3, Part A related to the
date of incorporation by reference of
global warming potentials (GWPs) and
the computation of the mass of carbon
dioxide equivalent.72 The revisions in
the 2021 and 2023 SIP Submittals that
are described below have State effective
dates of February 14, 2021, and
February 14, 2023, respectively. The
revisions do not interfere with
attainment or maintenance of any of the
NAAQS and would not interfere with
any other applicable requirement of the
CAA, and are therefore approvable
under CAA section 110(l). EPA will
propose action on the remaining
revisions to Regulation 3, Parts A, B,
and D in a separate rulemaking.
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1. Regulation 3, Part A, Sections I.B.10
and 1.B.44.b.(i)—Date of Incorporation
by Reference of Global Warming
Potentials
Colorado’s Regulation 3, Part A,
Section I.B.10 defines ‘‘carbon dioxide
equivalent’’ as a metric used to compare
emissions of various greenhouse gases.
The metric is based in part on each gas’s
GWP as codified in 40 CFR part 98,
subpart A, table A–1, which Regulation
3 incorporates by reference. Regulation
3, Part A, Section I.B.44.b.(i), which
provides conditions under which GHGs
are ‘‘subject to regulation,’’ makes the
71 U.S. EPA, ‘‘Draft Guidance on the
Implementation of an Emission Statement Program’’
(July 1992), 3.
72 References to specific sections of Regulation 3
in sections II.C.1 and II.C.2 of this proposed rule are
to the versions of Regulation 3 the State included
in the 2021 and 2023 SIP Submittals, namely: 2021
SIP Submittal, Document Set 4 of 6, ‘‘16_Reg Lang
& SBAP Adopted_R3’’; 2021 SIP Submittal,
Document Set 6 of 6, ‘‘22_5 CCR 1001–5’’; 2023 SIP
Submittal, Document Set 5 of 7, ‘‘17_Reg Lang &
SBAP Adopted_R3’’; and 2023 SIP Submittal,
Document Set 7 of 7, ‘‘23_5 CCR 1001–5.’’
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same incorporation by reference. In its
2021 SIP Submittal, the State replaced
the outdated November 20, 2013
incorporation by reference date with
December 11, 2014 in both Sections
1.B.10 and 1.B.44.b.(i).73 However,
while the November 20, 2013 date was
removed from Section 1.B.10 in the
Code of Colorado Regulations, the
revised date was inadvertently omitted,
leaving the incorporation by reference
without a corresponding date.74
Colorado’s 2023 SIP Submittal corrects
that omission.75 Since December 11,
2014, is the most recent date of revision
to the GWPs in 40 CFR part 98, Subpart
A, Table A–1, EPA is proposing to
approve the revisions from the 2021 and
2023 SIP Submittals that update the
date of incorporation by reference in
Regulation 3, Part A, sections I.B.10 and
1.B.44.b.(i).
2. Regulation 3, Part A, Section
I.B.44.(b).(i)—Computation of Mass of
Carbon Dioxide Equivalent
EPA is proposing to approve an
additional revision in Colorado’s 2023
SIP Submittal to Regulation 3, Part A,
Section I.B.44.b.(i).76 The revision
removes language stating that, prior to
July 21, 2014, the mass of carbon
dioxide shall not include emissions
resulting from the combustion or
decomposition of non-fossilized and
biodegradable organic material. The
removed language is consistent with the
definition of ‘‘subject to regulation’’ at
40 CFR 70.2, which instructed how to
compute the mass of carbon dioxide
equivalent before July 21, 2014. This
language was meant to defer the
application of Prevention of Significant
Deterioration and Title V programs to
certain sources of biogenic carbon
dioxide for three years.77 Because the
deferral period has since expired,
continued inclusion of this language in
the SIP is unnecessary.
III. Proposed Action
We are proposing to approve elements
of Colorado’s July 27, 2020, March 22,
2021, and June 26, 2023 SIP Submittals.
Specifically, we are proposing to
approve Colorado’s 2017 base year
inventory under CAA sections 172(c)(3)
and 182(a)(1). We are proposing to
approve Colorado’s certification of its
APEN reporting program (July 27, 2020
SIP Submittal) and the addition of the
73 2021 SIP Submittal, Document Set 4 of 6, ‘‘16_
Reg Lang & SBAP Adopted_R3.’’
74 2021 SIP Submittal, Document Set 6 of 6, ‘‘22_
5 CCR 1001–5,’’ 4.
75 2023 SIP Submittal, Document Set 5 of 7, ‘‘17_
Reg Lang & SBAP Adopted_R3.’’
76 Id.
77 76 FR 43490, 43490 (July 20, 2011).
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annual certification requirement in
Section II.A.3 to Regulation 3, Part A
(June 26, 2023 SIP Submittal) as meeting
the emission statement rule
requirements of CAA section
182(a)(3)(B). We are also proposing to
approve certain revisions to Regulation
3, Part A, specifically to the date of
incorporation by reference of GWPs in
Sections 1.B.10 and 1.B.44.b.(i) (March
22, 2021 and June 26, 2023 SIP
Submittals) and to the computation of
the mass of carbon dioxide equivalent in
Section 1.B.44.b.(i) (June 26, 2023 SIP
Submittal).
IV. Incorporation by Reference
In this document, the EPA is
proposing to include regulatory text in
an EPA final rule that includes
incorporation by reference. In
accordance with requirements of 1 CFR
51.5, the EPA is proposing to
incorporate by reference the APCD
revisions regarding annual APEN
certification, updated incorporation by
reference dates of CFR global warming
potentials, and revisions related to the
computation of carbon dioxide
equivalent, as described in sections II.B
and II.C of this proposed rule. The EPA
has made, and will continue to make,
these materials generally available
through www.regulations.gov and at the
EPA Region 8 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 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, the
EPA’s role is to approve state choices,
provided that they meet the criteria of
the CAA. Accordingly, this action
merely proposes to approve 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
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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, 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 CAA; and
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 proposed 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).
Executive Order 12898 (Federal
Actions To Address Environmental
Justice in Minority Populations and
Low-Income Populations, 59 FR 7629,
Feb. 16, 1994) directs Federal agencies
to identify and address
‘‘disproportionately high and adverse
human health or environmental effects’’
of their actions on minority populations
and low-income populations to the
greatest extent practicable and
permitted by law. EPA defines
environmental justice (EJ) as ‘‘the fair
treatment and meaningful involvement
of all people regardless of race, color,
national origin, or income with respect
to the development, implementation,
and enforcement of environmental laws,
regulations, and policies.’’ EPA further
defines the term fair treatment to mean
that ‘‘no group of people should bear a
disproportionate burden of
environmental harms and risks,
including those resulting from the
negative environmental consequences of
industrial, governmental, and
commercial operations or programs and
policies.’’
Colorado did not evaluate
environmental justice considerations as
part of its SIP submittal; the CAA and
applicable implementing regulations
neither prohibit nor require such an
evaluation. EPA did not perform an EJ
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analysis and did not consider EJ in this
action. Consideration of EJ is not
required as part of this action, and there
is no information in the record
inconsistent with the stated goal of
Executive Order 12898 of achieving
environmental justice for people of
color, low-income populations, and
Indigenous peoples.
List of Subjects in 40 CFR Part 52
Environmental protection, Air
pollution control, Carbon monoxide,
Greenhouse gases, Incorporation by
reference, Intergovernmental relations,
Lead, Nitrogen dioxide, Ozone,
Particulate matter, Reporting and
recordkeeping requirements, Sulfur
oxides, Volatile organic compounds.
Authority: 42 U.S.C. 7401 et seq.
Dated: April 2, 2024.
KC Becker,
Regional Administrator, Region 8.
[FR Doc. 2024–07584 Filed 4–9–24; 8:45 am]
BILLING CODE 6560–50–P
ENVIRONMENTAL PROTECTION
AGENCY
40 CFR Part 52
[EPA–R08–OAR–2024–0001; FRL–11838–
01–R8]
Extension of the Attainment Date and
Determination of Attainment by the
Attainment Date of the Uinta Basin
Marginal Nonattainment Area Under
the 2015 Ozone National Ambient Air
Quality Standards
Environmental Protection
Agency (EPA).
ACTION: Proposed rule.
AGENCY:
The Environmental Protection
Agency (EPA or Agency) is proposing
two Clean Air Act (CAA) actions related
to the attainment date for the Uinta
Basin (Basin), Utah Marginal
nonattainment area under the 2015
Ozone National Ambient Air Quality
Standards (NAAQS). First, the Agency
is proposing to grant a second 1-year
extension of the attainment date for the
area. This action would extend the
Marginal area attainment date for this
area from August 3, 2022, to August 3,
2023. Second, the Agency is proposing
to determine that the area attained the
standard by the extended attainment
date of August 3, 2023, based on
certified ozone monitoring data from
2020–2022. This action, if finalized, will
fulfill the EPA’s statutory obligation to
determine whether the Uinta Basin
Marginal ozone nonattainment area
attained the NAAQS by the attainment
SUMMARY:
PO 00000
Frm 00038
Fmt 4702
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25223
date through publication in the Federal
Register.
Written comments must be
received on or before May 10, 2024.
DATES:
Submit your comments,
identified by Docket ID No. EPA–R08–
OAR–2024–0001, to the Federal
Rulemaking Portal:
www.regulations.gov. Follow the online
instructions for submitting comments.
Once submitted, comments cannot be
edited or removed from
www.regulations.gov. The EPA may
publish any comment received to its
public docket. Do not submit
electronically any information you
consider to be Confidential Business
Information (CBI) or other information
whose disclosure is restricted by statute.
Multimedia submissions (audio, video,
etc.) must be accompanied by a written
comment. The written comment is
considered the official comment and
should include discussion of all points
you wish to make. The EPA will
generally not consider comments or
comment contents located outside of the
primary submission (i.e., on the web,
cloud, or other file sharing system). For
additional submission methods, the full
EPA public comment policy,
information about CBI or multimedia
submissions, and general guidance on
making effective comments, please visit
https://www2.epa.gov/dockets/
commenting-epa-dockets.
Docket: All documents in the docket
are listed in the www.regulations.gov
index. Although listed in the index,
some information is not publicly
available, e.g., CBI or other information
whose disclosure is restricted by statute.
Certain other material, such as
copyrighted material, will be publicly
available only in hard copy. Publicly
available docket materials are available
electronically in www.regulations.gov.
To reduce the risk of COVID–19
transmission, for this action we do not
plan to offer hard copy review of the
docket. Please email or call the person
listed in the FOR FURTHER INFORMATION
CONTACT section if you need to make
alternative arrangements for access to
the docket.
ADDRESSES:
FOR FURTHER INFORMATION CONTACT:
Amanda Brimmer, Air and Radiation
Division, EPA, Region 8, Mailcode
8ARD–IO, 1595 Wynkoop Street,
Denver, Colorado, 80202–1129, (303)
312–6323, brimmer.amanda@epa.gov.
In this
document ‘‘we,’’ ‘‘us,’’ and ‘‘our’’ mean
the EPA.
SUPPLEMENTARY INFORMATION:
E:\FR\FM\10APP1.SGM
10APP1
Agencies
[Federal Register Volume 89, Number 70 (Wednesday, April 10, 2024)]
[Proposed Rules]
[Pages 25216-25223]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2024-07584]
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ENVIRONMENTAL PROTECTION AGENCY
40 CFR Part 52
[EPA-R08-OAR-2023-0441; FRL-11837-01-R8]
Air Plan Approval; Colorado; 2017 Base Year Inventory and
Emission Statement Rule Marginal Nonattainment Requirements, Revisions
to Regulation 3
AGENCY: Environmental Protection Agency (EPA).
ACTION: Proposed rule.
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SUMMARY: The Environmental Protection Agency (EPA) is proposing to
approve state implementation plan (SIP) revisions submitted by the
State of Colorado to meet certain Clean Air Act (CAA) requirements
related to the Denver Metro/North Front Range (DMNFR) area's
classification as Marginal nonattainment for the 2015 8-hour ozone
national ambient air quality standards (NAAQS). The revisions contain a
base year emissions inventory for the nonattainment area and certify
that the State's existing Air Pollutant Emissions Notice (APEN) program
fulfills the CAA's emission statement rule requirement. The revisions
also include a new requirement for annual certification of APEN
reported emissions. Unrelated to Colorado's Marginal ozone
nonattainment obligations, EPA is also proposing to approve the State's
revisions to Regulation 3 concerning an update to the date of
incorporation by reference of global warming potentials used in the
computation of the carbon dioxide equivalent for comparing emissions
from various greenhouse gases (GHGs). EPA is taking this action
pursuant to the CAA.
DATES: Written comments must be received on or before May 10, 2024.
ADDRESSES: Submit your comments, identified by Docket ID No. EPA-R08-
OAR-2023-0441, to the Federal Rulemaking Portal: https://www.regulations.gov. Follow the online instructions for submitting
comments. Once submitted, comments cannot be edited or removed from
www.regulations.gov. The EPA may publish any comment received to its
public docket. Do not submit
[[Page 25217]]
electronically any information you consider to be Confidential Business
Information (CBI) or other information whose disclosure is restricted
by statute. Multimedia submissions (audio, video, etc.) must be
accompanied by a written comment. The written comment is considered the
official comment and should include discussion of all points you wish
to make. The EPA will generally not consider comments or comment
contents located outside of the primary submission (i.e., on the web,
cloud, or other file sharing system). For additional submission
methods, the full EPA public comment policy, information about CBI or
multimedia submissions, and general guidance on making effective
comments, please visit https://www2.epa.gov/dockets/commenting-epa-dockets.
Docket: All documents in the docket are listed in the
www.regulations.gov index. Although listed in the index, some
information is not publicly available, e.g., CBI or other information
whose disclosure is restricted by statute. Certain other material, such
as copyrighted material, will be publicly available only in hard copy.
Publicly available docket materials are available electronically in
www.regulations.gov. To reduce the risk of COVID-19 transmission, for
this action we do not plan to offer hard copy review of the docket.
Please email or call the person listed in the FOR FURTHER INFORMATION
CONTACT section if you need to make alternative arrangements for access
to the docket.
FOR FURTHER INFORMATION CONTACT: Matthew Lang, Air and Radiation
Division, EPA, Region 8, Mailcode 8ARD-IO, 1595 Wynkoop Street, Denver,
Colorado 80202-1129, (303) 312-6709, [email protected].
SUPPLEMENTARY INFORMATION: Throughout this document wherever ``we,''
``us,'' or ``our'' is used, we mean the EPA.
Table of Contents
I. Background
II. The EPA's Evaluation of Colorado's SIP Submittals
A. Base Year Emissions Inventory
1. Point Source Emissions
2. Nonpoint Source Emissions
3. On-Road Mobile Source Emissions
4. Nonroad Mobile Source Emissions
5. Oil and Gas Emissions
6. Biogenic Emissions
7. EPA's Evaluation of the Base Year Emissions Inventory
B. Certification of Existing Emission Statement Rule and
Addition of Annual Certification Requirement
C. Other Revisions to Regulation 3, Part A
1. Regulation 3, Part A, Sections I.B.10 and 1.B.44.b.(i)--Date
of Incorporation by Reference of Global Warming Potentials
2. Regulation 3, Part A, Section I.B.44.(b).(i)--Computation of
Mass of Carbon Dioxide Equivalent
III. Proposed Action
IV. Incorporation by Reference
V. Statutory and Executive Order Reviews
I. Background
EPA determined decades ago that ground-level ozone endangers public
health and welfare. Ground-level ozone forms when nitrogen oxides
(NOX) and volatile organic compounds (VOC) react in the
presence of sunlight. Referred to as ozone precursors, these two
pollutants are emitted by many types of pollution sources, including
motor vehicles, power plants, industrial facilities, and nonpoint \1\
sources. Scientific evidence indicates that adverse human health
effects occur following exposure to ozone. These effects are more
pronounced in children and adults with lung disease. Breathing air
containing ozone can reduce lung function and inflame airways, which
can increase respiratory symptoms and aggravate asthma or other lung
diseases. In 1979, in response to this scientific evidence, EPA
promulgated the first ozone NAAQS, the 0.12 parts per million (ppm) 1-
hour ozone NAAQS.\2\
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\1\ Nonpoint sources are also sometimes referred to as area
sources.
\2\ 44 FR 8202 (Feb. 8, 1979).
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EPA has strengthened the ozone NAAQS over the years. In 1997, EPA
promulgated a revised ozone NAAQS of 0.08 ppm, averaged over eight
hours, which it determined was more protective of public health than
the 1979 standard.\3\ In 2008, EPA revised the 8-hour ozone NAAQS from
0.08 to 0.075 ppm.\4\ In 2015, the Agency further strengthened the 8-
hour ozone NAAQS to 0.070 ppm.\5\
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\3\ 62 FR 38856 (July 18, 1997).
\4\ 73 FR 16436 (Mar. 27, 2008).
\5\ 80 FR 65292 (Oct. 26, 2015).
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The DMNFR area is in nonattainment status for both the 2008 and the
2015 ozone NAAQS. It is currently classified as a Severe nonattainment
area under the 2008 standard,\6\ which is not at issue in this
rulemaking. Effective August 3, 2018, EPA designated the DMNFR area as
Marginal nonattainment for the more stringent 2015 ozone NAAQS (2015
DMNFR Nonattainment Area).\7\ The 2015 DMNFR Nonattainment Area
includes Adams, Arapahoe, Boulder, Broomfield, Denver, Douglas,
Jefferson, and Weld counties as well as a portion of Larimer County.\8\
While EPA has since reclassified the 2015 DMNFR Nonattainment Area as
Moderate for failing to attain the 2015 ozone NAAQS by the area's
Marginal attainment date,\9\ Colorado must still meet the CAA
requirements applicable to Marginal ozone nonattainment areas.
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\6\ 40 CFR 81.306; 87 FR 60926, 60933 (Oct. 7, 2022).
\7\ 83 FR 25776, 25792 (June 4, 2018).
\8\ As detailed in this proposed rule, EPA initially excluded
part of Weld County from the 2015 DMNFR Nonattainment Area, but, in
response to a court decision, subsequently expanded its air quality
designation to include all of Weld County.
\9\ 40 CFR 81.306; 87 FR 60897, 60916 (Oct. 7, 2022).
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This proposed rule addresses only the base year inventory and
emission statement rule requirements related to the Marginal
nonattainment classification, as described further below, including SIP
revisions to address EPA's revised designation incorporating all of
Weld County into the nonattainment area.\10\ Requirements stemming from
the DMNFR Nonattainment Area's Moderate nonattainment classification
for the 2015 ozone NAAQS and the Severe classification for the 2008
ozone NAAQS will be addressed in separate EPA rulemakings.
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\10\ See 86 FR 67864, 67869 (Nov. 30, 2021) (noting that states
affected by the revised air quality designations would ``work with
their respective EPA Regional office to submit any necessary
supplements or revisions to fulfill the Marginal area SIP revision
requirements associated with the nonattainment boundaries in this
final action as expeditiously as practicable'').
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The CAA and its implementing regulations--in particular, the 2015
ozone NAAQS SIP Requirements Rule,\11\ codified at 40 CFR part 51,
subpart CC--establish several requirements for ozone nonattainment
areas. Section 172(c)(3) of the CAA, which applies generally to states
with areas classified as nonattainment for any NAAQS, requires
submission of comprehensive, accurate, and current inventories of
actual emissions from all sources of relevant pollutants in Marginal
nonattainment areas.\12\ Specific to areas classified as Marginal ozone
nonattainment, section 182(a)(1) requires states to submit a base year
inventory of ozone precursors (NOX and VOC) within two years
of the nonattainment designation.\13\ Section 182(a)(3)(B) directs
states to implement an emission statement rule requiring certain
stationary sources to report their emissions of NOX and
VOC.\14\
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\11\ 83 FR 62998 (Dec. 6, 2018). The SIP Requirements Rule
established implementation requirements for the 2015 ozone NAAQS,
including requirements for base year emissions inventories.
\12\ 42 U.S.C. 7502(c)(3).
\13\ 42 U.S.C. 7511a(a)(1); 40 CFR 51.1315(a); 40 CFR 51.1300(p)
(defining ``base year inventory'').
\14\ 42 U.S.C. 7511a(a)(3)(B).
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[[Page 25218]]
Emissions inventories and emission statements provide data that
inform a variety of air quality planning tasks. States use emissions
inventories to establish baseline emissions levels, calculate emissions
reduction targets needed to attain the NAAQS, determine emissions
inputs for ozone air quality modeling analyses, and track emissions
over time to determine progress toward achieving air quality and
emissions reduction goals. EPA has issued guidance to assist states in
developing their emission inventories; states retain the discretion to
adopt approaches on a case-by-case basis that differ from that guidance
where appropriate.\15\ Emission statements provide important
information that states may use to develop emissions inventories for
air quality planning, to support permitting efforts, and to assist in
demonstrating source compliance.\16\
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\15\ U.S. EPA, ``Emissions Inventory Guidance for Implementation
of Ozone and Particulate Matter National Ambient Air Quality
Standards (NAAQS) and Regional Haze Regulations,'' EPA-454/B-17-002
(May 2017), 1 (2017 Emissions Inventory Guidance).
\16\ U.S. EPA, ``Draft Guidance on the Implementation of an
Emission Statement Program'' (July 1992), 1.
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On July 27, 2020, through the Colorado Department of Public Health
and Environment (CDPHE), Colorado submitted a SIP revision titled
``2015 Ozone National Ambient Air Quality Standard (NAAQS)--Denver
Metro/North Front Range Marginal Nonattainment Area Requirements''
(2020 SIP Submittal) to satisfy, in part, the emissions inventory
requirements under CAA sections 172(c)(3) and 182(a)(1) and the
emission statement requirement of CAA section 182(a)(3)(B).\17\
Colorado met the CAA's reasonable notice and public hearing
requirements \18\ for the 2020 SIP Submittal through notice in the
Denver Legal Post on May 23, 2020, and a public hearing on June 18,
2020.\19\ However, before EPA proposed action on the 2020 SIP
Submittal, the 2015 DMNFR Nonattainment Area boundary, and specifically
the partial nonattainment designation of Weld County, was remanded
without vacatur in Clean Wisconsin v. EPA, 964 F.3d 1145 (D.C. Cir.
2020). EPA then issued a revised designation to include the whole of
Weld County in the nonattainment area and noted that states should work
with their respective EPA regional office to submit any necessary
supplements or revisions to fulfill Marginal area SIP requirements.\20\
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\17\ 2020 SIP Submittal, ``01-Submittal Letter to EPA.'' The
letter is dated July 6, 2020, but the SIP was submitted to EPA on
July 27, 2020. The 2020 SIP Submittal was deemed complete by
operation of law six months after submission.
\18\ 42 U.S.C. 7410(a)(1), (l); 40 CFR 51.102.
\19\ 2020 SIP Submittal, ``03-Denver Post Legal Ad'' and ``04-
Meeting Agenda.''
\20\ 86 FR 67864, 67869. The revised designation was affirmed in
Board of County Commissioners of Weld County, Colorado v. EPA, 72
F.4th 284, 289-92 (D.C. Cir. 2023).
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In response, on June 26, 2023, CDPHE submitted a SIP revision
titled ``Ozone State Implementation Plan (SIP) and Associated
Regulations: Regulation Number 3, Regulation Number 7, Regulation
Number 21, Common Provisions, and Air Quality Standards, Designations,
and Emissions Budgets'' (2023 SIP Submittal).\21\ Among other
components,\22\ the 2023 SIP Submittal includes rule revisions to
address the outstanding Marginal area SIP requirements for the 2015
DMNFR Nonattainment Area, including an updated base year inventory
reflecting EPA's revised boundary designation of the 2015 DMNFR
Nonattainment Area. Colorado met the CAA's reasonable notice and public
hearing requirements through notice in the Denver Legal Post on
September 17, 2022, and a public hearing on December 13-16, 2022.\23\
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\21\ 2023 SIP Submittal, Document Set 1 of 7, ``00_Submittal
Letter to EPA_Ozone SIP.'' The letter is dated June 22, 2023, but
the SIP was submitted to EPA on June 26, 2023. EPA determined the
2023 SIP Submittal to be complete on September 7, 2023.
\22\ The 2023 SIP Submittal includes elements of Colorado's 2008
Severe Ozone SIP and its 2015 Moderate Ozone SIP. EPA will take
action on those SIP components in a separate rulemaking.
\23\ 2023 SIP Submittal, Document Set 1 of 7, ``05_Denver Post
Legal Ad'' and ``06_Meeting Agenda.''
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Finally, for purposes of administrative efficiency, EPA is
proposing to act on Colorado SIP revisions unrelated to the State's
Marginal ozone nonattainment obligations. On March 22, 2021, CDPHE
submitted a SIP revision (``2021 SIP Submittal'') that included
revisions to Regulation 3, Part A to update the date of incorporation
by reference of global warming potentials (GWPs) as defined in 40 CFR
part 98, subpart A, table A-1.\24\ Colorado met the CAA's reasonable
notice and public hearing requirements through notice in the Denver
Legal Post on September 26, 2020, and a public hearing on December 16-
18, 2020.\25\ Although EPA approved other elements of the 2021 SIP
Submittal in a March 27, 2023 final rule, we did not finalize action on
the revisions updating the date of incorporation by reference of GWPs
for the reasons discussed in that final rule \26\ and below. In
addition, Colorado's 2023 SIP Submittal included revisions to
Regulation 3 related to the incorporation by reference of GWPs that
build upon the aforementioned 2021 SIP Submittal revisions. We now
propose to act concurrently on the Regulation 3 GWP revisions from both
the 2021 SIP Submittal and subsequent 2023 SIP Submittal.
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\24\ 2021 SIP Submittal, Document Set 1 of 6, ``01_Submittal
Letter to EPA--121820_Ozone SIP, Reg 3, Reg 7, Air Quality
Stds_signed''; ``03_Hearing Notice & Proposed Language_R3.'' The
2021 SIP Submittal was deemed complete by operation of law six
months after submission.
\25\ 2021 SIP Submittal, Document Set 1 of 6, ``05_Denver Post
Legal Ad'' and ``06_Meeting Agenda.''
\26\ 88 FR 18054, 18054 (Mar. 27, 2023).
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II. The EPA's Evaluation of Colorado's SIP Submittals
A. Base Year Emissions Inventory
Under CAA sections 172(c)(3) and 182(a)(1), Colorado must submit a
comprehensive, accurate, and current accounting of actual emissions of
ozone precursors from all sources (point, nonpoint, nonroad mobile, and
on-road mobile sources) in the 2015 DMNFR Nonattainment Area. EPA's SIP
Requirements Rule specifies that the inventory year shall be selected
consistent with the baseline year for the Reasonable Further Progress
(RFP) plan under 40 CFR 51.1310(b),\27\ which EPA identified as
2017.\28\ The rule also requires states to report ``ozone season day
emissions'' in the base year inventory,\29\ as described in other EPA
regulations:
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\27\ 40 CFR 51.1315(a).
\28\ 83 FR 62998, 63005.
\29\ 40 CFR 51.1315(c).
Ozone season day emissions means an average day's emissions for
a typical ozone season work weekday. The state shall select, subject
to EPA approval, the particular month(s) in the ozone season and the
day(s) in the work week to be represented, considering the
conditions assumed in the development of RFP plans and/or emissions
budgets for transportation conformity.\30\
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\30\ 40 CFR 51.1300(q).
Based on EPA's 2017 Emissions Inventory Guidance for Implementation
of Ozone and Particulate Matter National Ambient Air Quality Standards
(NAAQS) and Regional Haze Regulations (2017 Emissions Inventory
Guidance), the selected ozone season day should be representative of
the conditions leading to nonattainment.\31\
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\31\ 2017 Emissions Inventory Guidance, 75.
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To satisfy these requirements, Colorado included a 2017 base year
inventory in its 2020 SIP Submittal.\32\ Following EPA's revised
designation of the 2015 DMNFR Nonattainment Area, Colorado then
submitted a revised base year inventory in its 2023 SIP Submittal as a
superseding supplement to its 2020 SIP Submittal to account for
emissions from the revised nonattainment area, including the whole of
Weld County.\33\
[[Page 25219]]
Consistent with the SIP Requirements Rule, the revised inventory uses
2017 as the base year for SIP planning purposes.\34\ It was developed
for a typical July day in 2017 to estimate NOX and VOC
emissions during the peak summer ozone season, which is representative
of the conditions leading to nonattainment in the 2015 DMNFR
Nonattainment Area.\35\ Consistent with the 2017 Emissions Inventory
Guidance, the inventory estimates emissions from all major source
categories including point sources, nonpoint sources, on-road and
nonroad mobile sources, and biogenic sources.\36\ Additional
information describing Colorado's general methodology for compiling its
emissions inventory may be found in the State's inventory technical
support document included in the 2023 SIP Submittal.\37\
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\32\ 2020 SIP Submittal, ``08-Denver 2017 Ozone NAA Inventory.''
\33\ 2023 SIP Submittal, Document Set 6 of 7, ``2017 Baseline
Inventory Update TSD FINAL,'' 1-2 (``2017 Baseline Inventory Update
TSD''); 2023 SIP Submittal, Document Set 6 of 7, ``APCD_FINAL_SIP-
2015,'' ch. 3 (``Revised Milestone Emission Inventory'').
\34\ 83 FR 62998, 63005, 63011 n.29.
\35\ 2017 Baseline Inventory Update TSD, 2.
\36\ Id.; Revised Milestone Emission Inventory, ch. 3; 2017
Emissions Inventory Guidance, 19, 81.
\37\ 2017 Baseline Inventory Update TSD, 1-14.
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Tables 1 and 2 of this proposed rule show 2017 ozone season day
emissions for the 2015 DMNFR Nonattainment Area in units of tons per
day (tpd). Table 1 summarizes anthropogenic VOC and NOX
emissions by source sector. Table 2 summarizes biogenic VOC and
NOX emissions, including those from fire and other naturally
occuring emissions not included as anthropogenic emissions in Table 1.
The anthropogenic portion of the base year inventory for a
nonattainment area may serve as the Rate of Progress (ROP)/RFP baseline
inventory for Moderate and higher nonattainment classifications.\38\
The following sections II.A.1-II.A.6 describe the State's inventory of
emissions from the various source sectors in more detail.
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\38\ 2017 Emissions Inventory Guidance, 41.
Table 1--Denver Metro/North Front Range Nonattainment Area 2017 VOC and
NOX Base Year Anthropogenic Emissions Inventory
[Tons/Day] \39\
------------------------------------------------------------------------
Source type NOX VOC
------------------------------------------------------------------------
Point................................................. 24.2 21.9
Nonpoint.............................................. 0.1 80.1
On-road Mobile........................................ 57.4 48.1
Nonroad Mobile........................................ 42.9 44.5
Oil & Gas............................................. 78.2 211.1
-----------------
Total............................................. 202.9 405.7
------------------------------------------------------------------------
Table 2--Denver Metro/North Front Range Nonattainment Area 2017 VOC and
NOX Base Year Biogenic Emissions
[Tons/Day] \40\
------------------------------------------------------------------------
Source type NOX VOC
------------------------------------------------------------------------
Biogenic.............................................. 26.5 419.0
------------------------------------------------------------------------
1. Point Source Emissions
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\39\ Revised Milestone Emission Inventory, 3.2.2.1, tbl. 7.
\40\ Id. at 3.2.2.7, tbl. 15.
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Point sources are large, stationary, identifiable sources of
emissions that release pollutants into the atmosphere. In its 2017 base
year inventory, the State included point source emissions from source
categories including power plants/electric generating units, external
combustion boilers, industrial processes, internal combustion sources,
petroleum/solvent evaporation not associated with the oil and gas
industry, and waste disposal.\41\ The SIP Requirements Rule provides
that emissions from point sources shall be reported according to the
thresholds of EPA's Air Emissions Reporting Requirements (AERR).\42\
The 2017 Emissions Inventory Guidance directs those preparing point
source inventories to volume 2 of the Emissions Inventory Improvement
Program technical report series for information on point source
inventory methodology.\43\ This resource describes the three principal
methods for estimating point source emissions as source testing, mass
balance calculations, and emission factors, with a fourth method
utilizing engineering calculations if the principal methods are not
possible.\44\
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\41\ Colorado's methodology and results for the point source
category are described in section 3.2.2.3 of the Revised Milestone
Emission Inventory.
\42\ 40 CFR 51.1315(d).
\43\ 2017 Emissions Inventory Guidance, 81-82.
\44\ U.S. EPA, EIIP Technical Report Series Vol. II, Ch. 1:
``Introduction to Stationary Point Source Emission Inventory
Development'' (May 2001), 1.4-1--1.4-3.
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Colorado obtained its point source data from the APEN database, the
State's emissions reporting system for stationary sources.\45\ Colorado
requires an APEN to be filed for emission points in a nonattainment
area with uncontrolled actual emissions of one ton per year or more of
any criteria pollutant that the area is designated nonattainment
for.\46\ In order of preferred methodology, APEN emission estimates are
based on actual test data or, in the absence of such data, on mass
balance calculations, published emission factors, or engineering
calculations.\47\ Since Colorado's base year inventory is consistent
with the reporting thresholds in the AERR and uses methods for
estimating emissions recommended by EPA guidance, the base year
inventory adequately addresses emissions from the point source
category.
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\45\ Revised Milestone Emission Inventory, 3.2.2.3.
\46\ 5 CCR 1001-5:3A.II.B.3.a.
\47\ 5 CCR 1001-5:3A.II.B.1.
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2. Nonpoint Source Emissions
Nonpoint sources are sources of pollution that are small and
numerous and that have not been inventoried as specific point sources
or mobile sources. They include a wide range of categories such as
coatings, household and personal care products, pesticides, automotive
aftermarket products, and sealants. Inventorying nonpoint sources
involves grouping them by category and estimating their emissions
collectively using one methodology.
The State developed the nonpoint source emissions inventory \48\
from the 2016v2 EPA modeling platform,\49\ which includes emission
inventories for 2016 and 2023. To establish emissions for 2017 from the
2016v2 platform, the State used a linear interpolation from 2016 to
2023. Because a portion of Larimer County is not part of the 2015 DMNFR
Nonattainment Area, the State scaled the whole-county emissions by the
ratio of the county population residing within the nonattainment area
boundary based on 2020 census block data--0.9776--to determine an
accurate emissions contribution for the relevant part of Larimer
County. The nonpoint source portion of Colorado's emissions inventory
includes source categories addressed in the nonpoint portion of the
inventories developed for EPA's 2016v2 platform. Colorado used EPA
estimates for the nonpoint source category and apportioned partial
county emissions using methods consistent with the 2017 Emissions
Inventory Guidance.\50\
[[Page 25220]]
Therefore, the base year inventory adequately addresses emissions from
the nonpoint source category.
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\48\ Colorado's methodology and results for the nonpoint source
category are described in section 3.2.2.4 of the Revised Milestone
Emission Inventory.
\49\ The 2016v2 modeling platform includes a set of emissions
inventories, data files, software tools, and scripts used for air
quality modeling. Files and technical support documents are
available at: https://www.epa.gov/air-emissions-modeling/2016v2-platform. The 2016v2 modeling platform draws on data from the 2017
National Emissions Inventory and includes point sources, nonpoint
sources, commercial marine vessels, on-road and nonroad mobile
sources, and fires for the U.S., Canada, and Mexico. U.S. EPA,
``Technical Support Document (TSD): Preparation of Emissions
Inventories for the 2016v2 North American Emissions Modeling
Platform,'' EPA-454/B-22-001 (Feb. 2022), 1-2.
\50\ 2017 Emissions Inventory Guidance, 72-73, 131-32.
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3. On-Road Mobile Source Emissions
For on-road mobile sources (vehicles operated on public roadways),
Colorado's 2017 base year inventory includes emissions from passenger
cars, motorcycles, light trucks, refuse/single-unit trucks, short/long-
haul trucks, and buses.\51\ The State estimated these emissions using
EPA's Motor Vehicle Emissions Simulator model version 3 (MOVES3 \52\)
along with link-level (roadway) vehicle miles traveled (VMT) provided
by the two metropolitan planning organizations that serve the 2015
DMNFR Nonattainment Area, the Denver Regional Council of Governments
and the North Front Range Metropolitan Planning Organization. The State
based VMT on travel demand model output data from those two
organizations and apportioned it to the nonattainment area at the
roadway level using Geographic Information Systems. Additional MOVES3
model inputs include vehicle population and age distribution, roadway
activity data (speed and time of day), roadway classifications (urban,
rural, restricted, unrestricted), fuel properties, inspection and
maintenance program characteristics, and hourly meteorology. These
model inputs are described in greater detail in EPA's MOVES3 technical
guidance.\53\ Specific MOVES3 on-road inputs used by the State are
identified in Appendix A to the 2017 Baseline Inventory Update
Technical Support Document. The State based model inputs on conditions
on an average July weekday and used the MOVES3 default fuel
formulation. It calculated NOX and VOC emission factors from
MOVES3 for each vehicle type and then multiplied these emission factors
by the roadway-level VMT to establish on-road mobile source emissions.
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\51\ Colorado's methodology and results for the on-road mobile
source category are described in section 3.2.2.6 of the Revised
Milestone Emission Inventory and in section 3.1.1 and Appendix A of
the 2017 Baseline Inventory Update TSD.
\52\ MOVES3 files and technical support documents are available
at: https://www.epa.gov/moves/moves-versions-limited-current-use.
\53\ U.S. EPA, ``MOVES3 Technical Guidance: Using MOVES to
Prepare Emission Inventories for State Implementation Plans and
Transportation Conformity,'' EPA-420-B-20-052 (Nov. 2020), 26-58.
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Colorado's on-road mobile source emissions inventory methodology
follows the SIP Requirements Rule, which states that ``the latest
approved version of the [MOVES] model should be used to estimate
emissions from on-road and certain nonroad transportation sources.''
\54\ MOVES3 was the latest approved version of the model available at
the time that the State developed its 2017 base year inventory.
Colorado used local data on vehicle/roadway activity, meteorological
conditions, fuel use, and other information characterizing the DMNFR
area in 2017, as called for by EPA's 2017 Emissions Inventory
Guidance.\55\ Therefore, the base year inventory adequately addresses
emissions from the on-road mobile source category.
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\54\ 83 FR 62998, 63022.
\55\ 2017 Emissions Inventory Guidance, 89-90.
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4. Nonroad Mobile Source Emissions
Nonroad mobile sources are mobile sources other than on-road
vehicles, including engines used in lawn and garden equipment,
commercial and industrial equipment, construction and mining equipment,
aircraft, and locomotives. Colorado's 2017 base year inventory used
EPA's MOVES-Nonroad model to estimate emissions from nonroad mobile
sources in the 2015 DMNFR Nonattainment Area, except for emissions from
aviation, locomotives, and rail yards.\56\ MOVES-Nonroad exists as a
separate module from the on-road modeling capabilities within MOVES3.
The specific MOVES3 nonroad inputs used by the State are identified in
Appendix A to the 2017 Baseline Inventory Technical Support Document.
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\56\ Colorado's methodology and results for the nonroad mobile
source category are described in section 3.2.2.5 of the Revised
Milestone Emission Inventory and in section 3.1.2 and Appendix A of
the 2017 Baseline Inventory Update TSD.
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The State estimated aviation emissions based on data provided by
Denver International Airport (DIA) on fleet composition and activity
level, including estimates of emissions from aircraft and ground
support equipment such as auxiliary power units. It estimated 2017
aviation emissions from other airports within the nonattainment area
using a linear interpolation between the 2016 and 2023 point source
emissions from the 2016v2 EPA modeling platform, with DIA emissions
excluded. The State also used the 2016v2 modeling platform to estimate
emissions from railroad locomotives and rail yard switcher locomotives.
It apportioned line-haul locomotive activity levels by track mileage in
the nonattainment area. As with the aviation and nonpoint source
sectors, Colorado determined 2017 locomotive emissions from a linear
trend between 2016 and 2023 estimates from the 2016v2 platform.
As directed in the SIP Requirements Rule,\57\ Colorado used the
most recently available version of EPA's MOVES-Nonroad model to
estimate emissions from certain nonroad sources. Furthermore, Colorado
used EPA's own 2016v2 platform to account for emissions from aviation,
locomotives, and rail yards not covered by the MOVES-Nonroad model.
Finally, for emissions specifically from DIA, the major international
airport in the DMNFR nonattainment area, the State relied on data
provided from the airport that provides valuable detail regarding DIA
emissions. Therefore, the base year inventory adequately addresses
emissions from the non-road mobile source category.
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\57\ 83 FR 62998, 63022.
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5. Oil and Gas Emissions
To inventory oil and gas emissions for its 2023 SIP Submittal,
Colorado relied on extensive industry outreach it had conducted between
2015-2018 to develop emission inventories for its 2008 8-hour Ozone
DMNFR Nonattainment Area Moderate and Serious SIPs.\58\ The State based
its approach to the oil and gas emissions component of its inventory on
actual and survey data from operators in the specific geological basin.
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\58\ Colorado's methodology and results for the oil and gas
source category are described in section 3.2.2.2 of the Revised
Milestone Emission Inventory and in sections 3.2 and 3.3 of the 2017
Baseline Inventory Update TSD.
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Colorado's 2017 base year emissions inventory categorizes emissions
from the oil and gas sector into point sources, condensate/oil tanks,
and nonpoint sources. The State used APEN reported data to determine
emissions from point sources, including external combustion boilers,
industrial processes, internal combustion sources, petroleum/solvent
evaporation, and waste disposal. As described previously, Colorado's
APEN reporting program meets the point source thresholds in EPA's AERR
and uses methods for estimating emissions consistent with that
recommended by EPA guidance. Therefore, the base year inventory
adequately addresses the point source component of oil and gas
emissions.
Colorado based condensate tank emissions (the largest single source
of VOC emissions in the 2017 base year inventory) on APEN reported
data, data collected by the Colorado Energy and Carbon Management
Commission, and data reported directly by the industry. The State
developed site-specific uncontrolled tank emission factors and
multiplied them by facilities' production in barrels per year. It then
[[Page 25221]]
adjusted the resulting emissions to account for several factors
relevant to condensate tanks: a control device's destruction and
removal efficiency (DRE) of emissions; the capture efficiency of a
control device (a fractional factor intended to discount a control
device's DRE to account for actual operating conditions and potential
process/device upsets); and the rule effectiveness of regulations (a
discount factor that scales a control device's DRE downward to account
for a degree of noncompliance with applicable regulations). Since
Colorado estimated condensate tank emissions using APEN reported data
as well as additional industry-specific data and site-specific emission
factors, the base year inventory adequately addresses emissions from
the condensate tank portion of the oil and gas component.
Oil and gas nonpoint sources in Colorado's inventory include
emissions from certain production equipment and operations (e.g.,
emissions from well pad engines, truck loading, pneumatic devices,
fugitives, blowdowns, process heaters, separator control, and water
tank losses). Nonpoint source emissions also result from pre-production
operations, including from drill rig engines, hydraulic fracturing
engines, drilling mud degassing, and venting during completion
operations. The State estimated some of these emissions based on
facility/equipment level data reported by 11 producers as part of the
stakeholder group it convened in 2018, with emissions scaled to account
for the entirety of the 2015 DMNFR Nonattainment Area including the
whole of Weld County. Colorado used 2017 NEI data to supplement pre-
production emissions for categories not included in producer-submitted
data. The State determined drilling mud degassing emissions that were
not captured in producer-submitted information, or the 2017 NEI, from
EPA's 2016v2 modeling platform by interpolating emissions to 2017 from
2016 and 2023 emissions. Since Colorado relied on basin-specific
producer submitted information in developing its oil and gas nonpoint
source inventory, in addition to emissions from EPA's own 2017 NEI and
2016v2 platform, the base year inventory adequately addresses emissions
from the oil and gas nonpoint source component.
6. Biogenic Emissions
Biogenic emissions come from natural sources. Colorado included a
2017 inventory of biogenic emissions separate from the anthropogenic
portion of the inventory.\59\ The State used EPA's Biogenic Emissions
Inventory System (BEIS), version 3, which EPA developed specifically
for estimating biogenic emissions for inventories.\60\ Since Colorado
used the BEIS model to estimate emissions, as recommended by EPA
guidance, the base year inventory adequately addresses emission from
the biogenic source category.
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\59\ Colorado's methodology and results for the biogenic source
category are described in section 3.2.2.7 of the Revised Milestone
Emission Inventory.
\60\ 2017 Emissions Inventory Guidance, 101-102.
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7. EPA's Evaluation of the Base Year Emissions Inventory
Based on EPA's review and evaluation of the methodologies,
procedures, and results in Colorado's 2017 base year emissions
inventory, we propose to find that the inventory meets the requirements
of CAA sections 172(c)(3) and 182(a)(1) and the SIP Requirements Rule.
The base year inventory is based on the most current and accurate
information that was available to the State at the time the inventory
was developed. Additionally, the 2017 inventory comprehensively
addresses all source categories in the 2015 DMNFR Nonattainment Area
including the whole of Weld County and was developed consistent with
the relevant EPA emissions inventory regulations, guidance, and models.
B. Certification of Existing Emission Statement Rule and Addition of
Annual Certification Requirement
Under CAA section 182(a)(3)(B), Colorado must implement an emission
statement rule requiring certain stationary sources that emit VOC or
NOX in the nonattainment area to report on their emissions
at least annually.\61\ Section 182(a)(3)(B)(ii) specifies that a state
may waive this requirement for sources that emit less than 25 tpy of
VOC or NOX if the state includes emissions from such sources
in its base year or periodic inventories.\62\ If a state already has an
EPA-approved emissions reporting regulation in place and determines
that it is adequate to meet the requirements of section 182(a)(3)(B),
EPA may accept a SIP revision with the state's written certification of
that determination in lieu of the state submitting new revised
regulations.\63\ In its 2020 SIP Submittal, Colorado certified that its
existing SIP-approved APEN program meets the source reporting
requirements for an emission statement rule under CAA section
182(a)(3)(B).\64\
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\61\ 42 U.S.C. 7511a(a)(3)(B)(i).
\62\ 42 U.S.C. 7511a(a)(3)(B)(ii).
\63\ 83 FR 62998, 63001-02.
\64\ Collectively, the information contained in ``01-Submittal
Letter to EPA,'' ``06-Issue Statement,'' and ``07-CAA Elements
Table'' in the 2020 SIP Submittal satisfies the certification
requirements outlined in the SIP Requirements Rule, 83 FR 62998,
63001-02.
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Colorado's APEN program requires stationary sources with
uncontrolled actual emissions of one tpy or more of any individual
criteria pollutant for which the area is in nonattainment to file an
APEN with the Colorado Air Pollution Control Division (APCD).\65\
Emission estimates reported on the APEN must be based on actual test
data or, in the absence of such data, on an alternative estimation
acceptable to the APCD.\66\ Each APEN must include the location of the
source; the operator's name and address; the nature of the facility,
process or activity; an estimate of the quantity and composition of
emissions; and other specified information that varies based on the
type of source.\67\ An APEN is valid for five years \68\ but must be
revised (1) annually whenever a significant change in annual actual
emissions occurs or (2) upon the occurrence of a triggering event, such
as a change in the owner/operator, the installation of new control
equipment, or the modification of a permit limitation.\69\ To ensure
the accuracy of APEN reported emissions between triggering events,
Colorado's 2023 SIP Submittal includes revisions to add section II.A.3
to Regulation 3, Part A.\70\ The new section II.A.3 requires stationary
sources in the ozone nonattainment area with the potential to emit 25
tpy or more of NOX or VOC to annually certify through an
APCD-approved format that annual actual emissions are as reported on
the source's APEN.
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\65\ 5 CCR 1001-5:3A.II.A.1, II.B.3.a.
\66\ 5 CCR 1001-5:3A.II.B.1.
\67\ 5 CCR 1001-5:3A.II.A.1.
\68\ 5 CCR 1001-5:3A.II.B.2.
\69\ 5 CCR 1001-5:3A.II.C.
\70\ 2023 SIP Submittal, Document Set 5 of 7, ``17_Reg Lang &
SBAP Adopted_R3.''
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EPA is proposing to concurrently approve Colorado's certification
of its APEN program in its 2020 SIP Submittal, as well as the State's
associated addition of the annual certification provision in section
II.A.3 to Regulation 3, Part A in its 2023 SIP Submittal, as meeting
the requirements for an emission statement rule under CAA section
182(a)(3)(B). As recommended by EPA guidance, the APEN program requires
certification of data accuracy and submission of source identification
information, operating schedule, emissions information, control
equipment information, and
[[Page 25222]]
process data.\71\ Since Colorado's 2017 base year inventory, as
described previously in this proposed rule, includes emissions from
sources below 25 tpy and is based on acceptable methodologies,
Colorado's APEN reporting program satisfies the criteria for the waiver
in CAA section 182(a)(3)(B)(ii). Therefore, EPA proposes to approve the
State's APEN reporting program under CAA section 182(a)(3)(B).
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\71\ U.S. EPA, ``Draft Guidance on the Implementation of an
Emission Statement Program'' (July 1992), 3.
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C. Other Revisions to Regulation 3, Part A
EPA is also proposing action on certain other revisions to
Regulation 3 unrelated to the State's Marginal ozone nonattainment
obligations. Colorado's 2021 and 2023 SIP Submittals included several
revisions to Regulation 3, Parts A, B, and D. In this rulemaking, we
are proposing action on the State's revisions to Regulation 3, Part A
related to the date of incorporation by reference of global warming
potentials (GWPs) and the computation of the mass of carbon dioxide
equivalent.\72\ The revisions in the 2021 and 2023 SIP Submittals that
are described below have State effective dates of February 14, 2021,
and February 14, 2023, respectively. The revisions do not interfere
with attainment or maintenance of any of the NAAQS and would not
interfere with any other applicable requirement of the CAA, and are
therefore approvable under CAA section 110(l). EPA will propose action
on the remaining revisions to Regulation 3, Parts A, B, and D in a
separate rulemaking.
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\72\ References to specific sections of Regulation 3 in sections
II.C.1 and II.C.2 of this proposed rule are to the versions of
Regulation 3 the State included in the 2021 and 2023 SIP Submittals,
namely: 2021 SIP Submittal, Document Set 4 of 6, ``16_Reg Lang &
SBAP Adopted_R3''; 2021 SIP Submittal, Document Set 6 of 6, ``22_5
CCR 1001-5''; 2023 SIP Submittal, Document Set 5 of 7, ``17_Reg Lang
& SBAP Adopted_R3''; and 2023 SIP Submittal, Document Set 7 of 7,
``23_5 CCR 1001-5.''
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1. Regulation 3, Part A, Sections I.B.10 and 1.B.44.b.(i)--Date of
Incorporation by Reference of Global Warming Potentials
Colorado's Regulation 3, Part A, Section I.B.10 defines ``carbon
dioxide equivalent'' as a metric used to compare emissions of various
greenhouse gases. The metric is based in part on each gas's GWP as
codified in 40 CFR part 98, subpart A, table A-1, which Regulation 3
incorporates by reference. Regulation 3, Part A, Section I.B.44.b.(i),
which provides conditions under which GHGs are ``subject to
regulation,'' makes the same incorporation by reference. In its 2021
SIP Submittal, the State replaced the outdated November 20, 2013
incorporation by reference date with December 11, 2014 in both Sections
1.B.10 and 1.B.44.b.(i).\73\ However, while the November 20, 2013 date
was removed from Section 1.B.10 in the Code of Colorado Regulations,
the revised date was inadvertently omitted, leaving the incorporation
by reference without a corresponding date.\74\ Colorado's 2023 SIP
Submittal corrects that omission.\75\ Since December 11, 2014, is the
most recent date of revision to the GWPs in 40 CFR part 98, Subpart A,
Table A-1, EPA is proposing to approve the revisions from the 2021 and
2023 SIP Submittals that update the date of incorporation by reference
in Regulation 3, Part A, sections I.B.10 and 1.B.44.b.(i).
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\73\ 2021 SIP Submittal, Document Set 4 of 6, ``16_Reg Lang &
SBAP Adopted_R3.''
\74\ 2021 SIP Submittal, Document Set 6 of 6, ``22_5 CCR 1001-
5,'' 4.
\75\ 2023 SIP Submittal, Document Set 5 of 7, ``17_Reg Lang &
SBAP Adopted_R3.''
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2. Regulation 3, Part A, Section I.B.44.(b).(i)--Computation of Mass of
Carbon Dioxide Equivalent
EPA is proposing to approve an additional revision in Colorado's
2023 SIP Submittal to Regulation 3, Part A, Section I.B.44.b.(i).\76\
The revision removes language stating that, prior to July 21, 2014, the
mass of carbon dioxide shall not include emissions resulting from the
combustion or decomposition of non-fossilized and biodegradable organic
material. The removed language is consistent with the definition of
``subject to regulation'' at 40 CFR 70.2, which instructed how to
compute the mass of carbon dioxide equivalent before July 21, 2014.
This language was meant to defer the application of Prevention of
Significant Deterioration and Title V programs to certain sources of
biogenic carbon dioxide for three years.\77\ Because the deferral
period has since expired, continued inclusion of this language in the
SIP is unnecessary.
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\76\ Id.
\77\ 76 FR 43490, 43490 (July 20, 2011).
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III. Proposed Action
We are proposing to approve elements of Colorado's July 27, 2020,
March 22, 2021, and June 26, 2023 SIP Submittals. Specifically, we are
proposing to approve Colorado's 2017 base year inventory under CAA
sections 172(c)(3) and 182(a)(1). We are proposing to approve
Colorado's certification of its APEN reporting program (July 27, 2020
SIP Submittal) and the addition of the annual certification requirement
in Section II.A.3 to Regulation 3, Part A (June 26, 2023 SIP Submittal)
as meeting the emission statement rule requirements of CAA section
182(a)(3)(B). We are also proposing to approve certain revisions to
Regulation 3, Part A, specifically to the date of incorporation by
reference of GWPs in Sections 1.B.10 and 1.B.44.b.(i) (March 22, 2021
and June 26, 2023 SIP Submittals) and to the computation of the mass of
carbon dioxide equivalent in Section 1.B.44.b.(i) (June 26, 2023 SIP
Submittal).
IV. Incorporation by Reference
In this document, the EPA is proposing to include regulatory text
in an EPA final rule that includes incorporation by reference. In
accordance with requirements of 1 CFR 51.5, the EPA is proposing to
incorporate by reference the APCD revisions regarding annual APEN
certification, updated incorporation by reference dates of CFR global
warming potentials, and revisions related to the computation of carbon
dioxide equivalent, as described in sections II.B and II.C of this
proposed rule. The EPA has made, and will continue to make, these
materials generally available through www.regulations.gov and at the
EPA Region 8 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 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, the EPA's role is to approve state choices,
provided that they meet the criteria of the CAA. Accordingly, this
action merely proposes to approve 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
[[Page 25223]]
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, 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 CAA; and
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 proposed 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).
Executive Order 12898 (Federal Actions To Address Environmental
Justice in Minority Populations and Low-Income Populations, 59 FR 7629,
Feb. 16, 1994) directs Federal agencies to identify and address
``disproportionately high and adverse human health or environmental
effects'' of their actions on minority populations and low-income
populations to the greatest extent practicable and permitted by law.
EPA defines environmental justice (EJ) as ``the fair treatment and
meaningful involvement of all people regardless of race, color,
national origin, or income with respect to the development,
implementation, and enforcement of environmental laws, regulations, and
policies.'' EPA further defines the term fair treatment to mean that
``no group of people should bear a disproportionate burden of
environmental harms and risks, including those resulting from the
negative environmental consequences of industrial, governmental, and
commercial operations or programs and policies.''
Colorado did not evaluate environmental justice considerations as
part of its SIP submittal; the CAA and applicable implementing
regulations neither prohibit nor require such an evaluation. EPA did
not perform an EJ analysis and did not consider EJ in this action.
Consideration of EJ is not required as part of this action, and there
is no information in the record inconsistent with the stated goal of
Executive Order 12898 of achieving environmental justice for people of
color, low-income populations, and Indigenous peoples.
List of Subjects in 40 CFR Part 52
Environmental protection, Air pollution control, Carbon monoxide,
Greenhouse gases, Incorporation by reference, Intergovernmental
relations, Lead, Nitrogen dioxide, Ozone, Particulate matter, Reporting
and recordkeeping requirements, Sulfur oxides, Volatile organic
compounds.
Authority: 42 U.S.C. 7401 et seq.
Dated: April 2, 2024.
KC Becker,
Regional Administrator, Region 8.
[FR Doc. 2024-07584 Filed 4-9-24; 8:45 am]
BILLING CODE 6560-50-P