Rule2024-29223
Reconsideration of the National Ambient Air Quality Standards for Particulate Matter; Correction
Primary source
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Published
December 19, 2024
Effective
December 19, 2024
Issuing agencies
Environmental Protection Agency
Abstract
The Environmental Protection Agency (EPA) is correcting a final rule published in the Federal Register on March 6, 2024, that became effective on May 6, 2024. The final rule revised the primary annual PM<INF>2.5</INF> standard by lowering the level from 12.0 [micro]g/m\3\ to 9.0 [micro]g/m\3\, retained the current primary 24- hour PM<INF>2.5</INF> standard and the primary 24-hour PM<INF>10</INF> standard, retained the secondary 24-hour PM<INF>2.5</INF> standard, secondary annual PM<INF>2.5</INF> standard, and secondary 24-hour PM<INF>10</INF> standard, and finalized revisions to the Air Quality Index (AQI) and monitoring requirements for the national ambient air quality standards for particulate matter (PM NAAQS). After publication, the EPA became aware of an error in the preamble text regarding the due date for infrastructure State implementation plan (infrastructure SIP) submissions for the 2024 p.m. NAAQS. With this action, the EPA is clarifying the due date for infrastructure SIP submissions for the 2024 p.m. NAAQS. The EPA is also correcting inadvertent errors in the PM<INF>2.5</INF> monitoring regulatory text. These corrections do not include any substantive changes to the final rule.
Full Text
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[Federal Register Volume 89, Number 244 (Thursday, December 19, 2024)]
[Rules and Regulations]
[Pages 103652-103657]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 2024-29223]
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ENVIRONMENTAL PROTECTION AGENCY
40 CFR Parts 50 and 58
[EPA-HQ-OAR-2015-0072; FRL-8635.1-02-OAR]
RIN 2060-AW48
Reconsideration of the National Ambient Air Quality Standards for
Particulate Matter; Correction
AGENCY: Environmental Protection Agency (EPA).
ACTION: Final rule; correction and correcting amendment.
-----------------------------------------------------------------------
SUMMARY: The Environmental Protection Agency (EPA) is correcting a
final rule published in the Federal Register on March 6, 2024, that
became effective on May 6, 2024. The final rule revised the primary
annual PM<INF>2.5</INF> standard by lowering the level from 12.0
[micro]g/m\3\ to 9.0 [micro]g/m\3\, retained the current primary 24-
hour PM<INF>2.5</INF> standard and the primary 24-hour PM<INF>10</INF>
standard, retained the secondary 24-hour PM<INF>2.5</INF> standard,
secondary annual PM<INF>2.5</INF> standard, and secondary 24-hour
PM<INF>10</INF> standard, and finalized revisions to the Air Quality
Index (AQI) and monitoring requirements for the national ambient air
quality standards for particulate matter (PM NAAQS). After publication,
the EPA became aware of an error in the preamble text regarding the due
date for infrastructure State implementation plan (infrastructure SIP)
submissions for the 2024 p.m. NAAQS. With this action, the EPA is
clarifying the due date for infrastructure SIP submissions for the 2024
p.m. NAAQS. The EPA is also correcting inadvertent errors in the
PM<INF>2.5</INF> monitoring regulatory text. These corrections do not
include any substantive changes to the final rule.
DATES: This correction is effective on December 19, 2024.
ADDRESSES: The EPA has established a docket for the final rule under
Docket ID No. EPA-HQ-OAR-2015-0072. All documents in the docket are
listed on the <a href="http://www.regulations.gov">www.regulations.gov</a> website. Although listed in the
index, some information is not publicly available, e.g., confidential
business information or other information whose disclosure is
restricted by statute. Certain other material, such as copyrighted
material, is not placed on the internet and will be publicly available
only in hard copy. Publicly available docket materials are available
electronically through <a href="http://www.regulations.gov">www.regulations.gov</a>.
FOR FURTHER INFORMATION CONTACT: Mr. Tim Hanley, Air Quality Assessment
Division, Office of Air Quality Planning and Standards, U.S.
Environmental Protection Agency, Mail Code C304-06, Research Triangle
Park, NC 27711; telephone: (919) 541-4417; email: <a href="/cdn-cgi/l/email-protection#2a424b44464f53045e43476a4f5a4b044d455c"><span class="__cf_email__" data-cfemail="8fe7eee1e3eaf6a1fbe6e2cfeaffeea1e8e0f9">[email protected]</span></a>.
SUPPLEMENTARY INFORMATION:
I. General Information
A. What is the authority for this action?
The EPA is correcting the deadline for infrastructure SIP
submissions under its authority provided in section 110(a)(1) of the
Clean Air Act (CAA) (42 U.S.C. 7410), which directs the States to
submit their implementation plans within 3 years after promulgation of
a primary or secondary NAAQS.
The EPA is also acting under the authority provided by CAA sections
103, 105, 110, 114, 301, 311, 314, and 319, which direct the EPA to
develop and implement measures to conduct ambient air quality
surveillance. Under this authority, this action implements minor, non-
substantive typographical and technical corrections to conform the 40
CFR part 58 regulatory text to the rule's preamble and remedies
regulatory text formatting errors.
B. What corrective action is the Agency taking?
Correction to Preamble of March 6 Final Rule
In the proposed rule published on January 27, 2023 (88 FR 5558),
the preamble states that ``Under CAA sections 110(a)(1), all states are
required to make these infrastructure SIP submissions within 3 years
after promulgation of a new or revised primary standard.'' However, in
the final rule published on March 6, 2024 (89 FR 16202), the preamble
incorrectly and inadvertently states that ``Under CAA section
110(a)(1), all States are required to make these infrastructure SIP
submissions within three years after the effective date of a new or
revised primary standard. While the CAA authorizes the EPA to set a
shorter time for States to make these SIP submissions, the EPA is
requiring submission of infrastructure SIPs within three years of the
effective date of this revised primary annual PM<INF>2.5</INF> NAAQS.''
Pursuant to CAA section 110(a)(1), infrastructure SIP submissions
are not
[[Page 103653]]
due within three years of the effective date, but within three years of
the promulgation of a new or revised NAAQS. The EPA has traditionally
held that ``promulgation'' means the signature and widespread
dissemination of a final rulemaking in the context of the NAAQS. Per
this standard practice, because the EPA promulgated (signed and made
available on the EPA's website) the reconsideration of the
PM<INF>2.5</INF> NAAQS on February 7, 2024, infrastructure SIP
submissions are due by no later than February 7, 2027.
To be consistent with the CAA and the proposed rule, the EPA is
correcting the last two sentences of the first paragraph of B. Section
110(a)(1) and (2) Infrastructure SIP Requirements in the final rule
preamble.
Correction
In FR Doc. 2024-02637, at 89 FR 16202 in the Federal Register of
March 6, 2024, on page 16367, in the second column, the last two
sentences of the first paragraph of B. Section 110(a)(1) and (2)
Infrastructure SIP Requirements are corrected to read as follows:
``Under CAA section 110(a)(1), all States are required to make
these infrastructure SIP submissions within three years after the
promulgation date of a new or revised primary standard. While the CAA
authorizes the EPA to set a shorter time for States to make these SIP
submissions, the EPA is requiring submission of infrastructure SIPs
within three years of the promulgation date of this revised primary
annual PM<INF>2.5</INF> NAAQS.''
Correcting Amendments to 40 CFR Parts 50 and 58
The EPA is also making several corrections to inadvertent errors in
the PM<INF>2.5</INF> monitoring regulatory text as described below.
After publication, it was realized that the EPA did not add
promulgated Sec. 50.20 to the 40 CFR 50.3 list of sections containing
PM<INF>2.5</INF> standards, which was inconsistent with past NAAQS
regulations. Therefore, in 40 CFR 50.3, the EPA is adding Sec. 50.20
to its list of sections containing PM<INF>2.5</INF> standards to be
consistent with all existing PM<INF>2.5</INF> standards and methods.
The EPA proposed to adjust the minimum value required by appendix
A, section 3.2.4, to be considered valid sample pairs for the
PM<INF>2.5</INF> Performance Evaluation Program (PEP) from 3 [micro]g/
m\3\ to 2 [micro]g/m\3\ (88 FR 5665, January 27, 2023). In section
3.2.4 of appendices A and B to part 58, the EPA finalized 2 [micro]g/
m\3\ for the quality assurance program that assesses PM<INF>2.5</INF>
network bias. However, in the final rule, section 4(c)(5) in appendix A
and section 4(b)(5) and (c) in appendix B, which provides the
PM<INF>2.5</INF> limit for use in bias assessments, was not updated to
reflect the finalized 2 [micro]g/m\3\ for PM<INF>2.5</INF> and instead
states the previous 3 [micro]g/m\3\, which is inconsistent with section
3.2.4 in the two appendices. Within the PM NAAQS, the same criteria
should be used for PM<INF>2.5</INF> for consistency. Therefore, the EPA
is correcting section 4(c)(5) of appendix A and section 4(b)(5) and (c)
of appendix B to part 58 to be consistent with section 3.2.4 of
appendices A and B to part 58.
In the PM NAAQS Reconsideration proposed rule (88 FR 5665, January
27, 2023), the EPA proposed to revise equation 6 in section 4.2.1 of
appendices A and B to part 58. The proposed equation 6 had a plus sign
in the denominator. However, in the final rule, the EPA inadvertently
published equation 6 with a minus sign in the denominator instead of a
plus sign. Therefore, the EPA is correcting the denominator in equation
6 of section 4.2.1 in appendices A and B by changing the minus sign to
a plus sign, which is consistent with what was proposed.
In section 2.2.2 in appendix C to part 58, the EPA is correcting a
typo by replacing ``multijusinstincional'' with
``multijurisdictional.''
Appendix C to part 58 of the final rule's regulatory text had an
incorrect instruction to remove and reserve sections 2.4 and 2.4.1 and
remove sections 2.4.1. through 2.4.1.7. The EPA's intention was to
reserve all of section 2.4, which includes sections 2.4.1 through 2.4.6
and their subsections, and to remove sections 2.4.1.1 through 2.4.1.7.
However, due to the EPA's confusing instructions, only sections 2.4 and
2.4.1 were reserved. To correct this issue, the EPA is reserving
sections 2.4.2 through 2.4.6 of appendix C to part 58, including their
subsections, so that all of section 2.4 is reserved as intended.
Also, when the EPA reserved section 2.4 in appendix C to part 58,
the EPA revoked language associated with Approved Regional Methods
(ARMs). However, after publication, several mentions of the revoked
term ``ARM'' and references to the reserved section 2.4 were left in
appendices A and C to part 58. To correct this issue, the EPA is
removing the revoked term ``ARM'' and references to the reserved
section 2.4 from section 3.2.4.2 in appendix A to part 58 and sections
2.7.1, 2.8.4, 2.7.6, 2.8.1, 2.8.5, and 3.1 in appendix C to part 58.
Lastly, after publication of the final rule, the EPA became aware
that, in the finalized tables E-3 and E-6 of appendix E to part 58,
several merged cells were inadvertently unmerged, resulting in
misalignment of the data presented for each pollutant-specific row in
the tables. The EPA is correcting this error by providing reformatted
tables E-3 and E-6 so that each pollutant-specific row and the
information in each column is displayed correctly.
II. Rulemaking Procedures
Section 553(b)(B) of the Administrative Procedure Act (APA), 5
U.S.C. 553(b)(B), provides that when an agency for good cause finds
that public notice and comment procedures are impracticable,
unnecessary, or contrary to the public interest, the agency may issue a
rule without providing notice and an opportunity for public comment.
The EPA has determined that there is good cause for making this
correction final without prior proposal. In this instance, notice and
opportunity for comment is unnecessary because this action implements
minor, non-substantive typographical and technical corrections that
correct preamble language in one instance, conform the regulatory text
to the rule's preamble, and remedy formatting errors.
Moreover, EPA has determined that there is good cause for making
this final rule effective less than 30 days after publication in the
Federal Register. Section 553(d)(3) of the APA, 5 U.S.C. 553(d)(3),
provides that final rules shall not become effective until 30 days
after publication in the Federal Register ``except . . . as otherwise
provided by the agency for good cause found and published with the
rule.'' ``In determining whether good cause exists, an agency should
`balance the necessity for immediate implementation against principles
of fundamental fairness which require that all affected persons be
afforded a reasonable amount of time to prepare for the effective date
of its ruling.'' Omnipoint Corp. v. Fed. Commc'n Comm'n, 78 F.3d 620,
630 (D.C. Cir. 1996) (quoting United States v. Gavrilovic, 551 F.2d
1099, 1105 (8th Cir. 1977)). This action adjusts a deadline that will
not apply for at least two years (from May 6, 2027, to February 7,
2027) and makes only minor technical and typographical corrections to
the monitoring provisions that are not connected to immediate
regulatory obligations.
For these reasons, the Agency finds that good cause exists under
APA section 553(d)(3) to make this rule effective on December 19, 2024.
[[Page 103654]]
III. Statutory and Executive Orders Reviews
Additional information about these statutes and Executive orders
can be found at <a href="https://www.epa.gov/laws-regulations/laws-and-executive-orders">https://www.epa.gov/laws-regulations/laws-and-executive-orders</a>.
A. Executive Order 12866: Regulatory Planning and Review and Executive
Order 14094: Modernizing Regulatory Review
This action is not a significant regulatory action as defined by
Executive Order 12866, as amended by Executive Order 14094 and was,
therefore, not subject to a requirement for Executive Order 12866
review.
B. Paperwork Reduction Act (PRA)
This action does not impose any new information collection burden
under the PRA. The EPA is clarifying the due date for infrastructure
SIP submissions for the 2024 PM NAAQS and correcting inadvertent errors
in the PM<INF>2.5</INF> monitoring regulatory text. However, the Office
of Management and Budget (OMB) has previously approved the information
collection activities contained in the existing regulations and has
assigned OMB control number 2060-0084.
C. Regulatory Flexibility Act (RFA)
I certify that this action will not have a significant economic
impact on a substantial number of small entities under the RFA. This
action will not impose any requirements on small entities. Rather, this
action corrects inadvertent errors in the final rule's preamble and
regulatory text.
D. Unfunded Mandates Reform Act (UMRA)
This action does not contain an unfunded mandate of $100 million or
more as described in the Unfunded Mandates Reform Act (UMRA), 2 U.S.C.
1531-1538, and does not significantly or uniquely affect small
governments. This action corrects inadvertent errors in the final
rule's preamble and regulatory text.
E. Executive Order 13132: Federalism
This action does not have federalism implications. It will not have
substantial direct effects on the states, on the relationship between
the National Government and the states, or on the distribution of power
and responsibilities among the various levels of government.
F. Executive Order 13175: Consultation and Coordination With Indian
Tribal Governments
This action does not have Tribal implications, as specified in
Executive Order 13175. It does not have a substantial direct effect on
one or more Indian Tribes as Tribes are not obligated to adopt or
implement any NAAQS. In addition, Tribes are not obligated to conduct
ambient monitoring for PM or to adopt the ambient monitoring
requirements of 40 CFR part 58. Thus, Executive Order 13175 does not
apply to this action.
G. Executive Order 13045: Protection of Children From Environmental
Health Risks and Safety Risks
The EPA interprets Executive Order 13045 as applying only to those
regulatory actions that concern environmental health or safety risks
that the EPA has reason to believe may disproportionately affect
children, per the definition of ``covered regulatory action'' in
section 2-202 of the Executive order. This action is not subject to
Executive Order 13045 because it does not concern an environmental
health risk or safety risk. This action corrects inadvertent errors in
the final rule's preamble and regulatory text.
H. Executive Order 13211: Actions Concerning Regulations That
Significantly Affect Energy Supply, Distribution or Use
This action is not subject to Executive Order 13211, because it is
not a significant regulatory action under Executive Order 12866.
I. National Technology Transfer and Advancement Act (NTTAA)
The final rule involved environmental monitoring or measurement.
The PM NAAQS final rule maintained the use of the existing indicators
for fine (PM<INF>2.5</INF>) and coarse (PM<INF>10</INF>) particles. The
indicator for fine particles is measured using the Reference Method for
the Determination of Fine Particulate Matter as PM<INF>2.5</INF> in the
Atmosphere (appendix L to 40 CFR part 50), which is known as the
PM<INF>2.5</INF> FRM, and the indicator for coarse particles is
measured using the Reference Method for the Determination of
Particulate Matter as PM<INF>10</INF> in the Atmosphere (appendix J to
40 CFR part 50), which is known as the PM<INF>10</INF> FRM. To the
extent feasible, the EPA employs a Performance-Based Measurement System
(PBMS), which does not require the use of specific, prescribed analytic
methods. The PBMS is defined as a set of processes wherein the data
quality needs, mandates or limitations of a program or project are
specified and serve as criteria for selecting appropriate methods to
meet those needs in a cost-effective manner. It is intended to be more
flexible and cost effective for the regulated community; it is also
intended to encourage innovation in analytical technology and improved
data quality. This action corrects inadvertent errors in the monitoring
regulatory text for parts 50 and 58.
J. Executive Order 12898: Federal Actions To Address Environmental
Justice in Minority Populations and Low-Income Populations
The EPA believes that this correction does not concern human health
or environmental conditions and, therefore, cannot be evaluated with
respect to potentially disproportionate and adverse effects on people
of color, low-income populations and/or indigenous peoples. This action
corrects inadvertent errors in the final rule's preamble and regulatory
text.
Although this action does not concern human health or environmental
conditions, the EPA identified and addressed environmental justice
concerns in the underlying final rule in sections II.A.2, II.B.3.a,
II.B.3.c, II.B.2, and II.B.4. of the final rule preamble and also in
the 2019 Integrated Science Assessment, Supplement to the 2019
Integrated Science Assessment, and 2022 Policy Assessment.
K. Congressional Review Act (CRA)
This action is subject to the CRA, and the EPA will submit a rule
report to each House of the Congress and to the Comptroller General of
the United States. The CRA allows the issuing agency to make a rule
effective sooner than otherwise provided by the CRA if the agency makes
a good cause finding that notice and comment rulemaking procedures are
impracticable, unnecessary or contrary to the public interest (5 U.S.C.
808(2)). The EPA has made a good cause finding for this rule as
discussed in the SUPPLEMENTARY INFORMATION section. The EPA has
determined that there is good cause for making this correction final
without prior proposal. In this instance, notice and opportunity for
comment is unnecessary because this action implements minor, non-
substantive typographical and technical corrections that conform the
regulatory text to the rule's preamble and remedy formatting errors.
[[Page 103655]]
List of Subjects
40 CFR Part 50
Environmental protection, Air pollution control, Particulate
matter.
40 CFR Part 58
Environmental protection, Administrative practice and procedure,
Air pollution control, Intergovernmental relations, Reporting and
recordkeeping requirements.
Michael S. Regan,
Administrator.
Accordingly, 40 CFR parts 50 and 58 are corrected by making the
following correcting amendments:
PART 50--NATIONAL PRIMARY AND SECONDARY AMBIENT AIR QUALITY
STANDARDS
0
1. The authority citation for part 50 continues to read as follows:
Authority: 42 U.S.C. 7401, et seq.
0
2. Revise Sec. 50.3 to read as follows:
Sec. 50.3 Reference conditions.
All measurements of air quality that are expressed as mass per unit
volume (e.g., micrograms per cubic meter) other than for particulate
matter (PM<INF>2.5</INF>) standards contained in Sec. Sec. 50.7,
50.13, 50.18, and 50.20, and lead standards contained in Sec. 50.16
shall be corrected to a reference temperature of 25 (deg) C and a
reference pressure of 760 millimeters of mercury (1,013.2 millibars).
Measurements of PM<INF>2.5</INF> for purposes of comparison to the
standards contained in Sec. Sec. 50.7, 50.13, 50.18, and 50.20, and of
lead for purposes of comparison to the standards contained in Sec.
50.16 shall be reported based on actual ambient air volume measured at
the actual ambient temperature and pressure at the monitoring site
during the measurement period.
PART 58--AMBIENT AIR QUALITY SURVEILLANCE
0
3. The authority citation for part 58 continues to read as follows:
Authority: 42 U.S.C. 7403, 7405, 7410, 7414, 7601, 7611, 7614,
and 7619.
0
4. Amend appendix A to part 58 by revising sections 3.2.4.2 and 4(c)(5)
and equation 6 in section 4.2.1 to read as follows:
Appendix A to Part 58--Quality Assurance Requirements for Monitors Used
in Evaluations of National Ambient Air Quality Standards
* * * * *
3.2.4.2 Have all FRM and FEM samplers subject to a PEP audit at
least once every 6 years, which equates to approximately 15 percent
of the monitoring sites audited each year.
* * * * *
4. * * *
(c) * * *
(5) PM<INF>2.5</INF>: 2 [micro]g/m\3\.
* * * * *
4.2.1 * * *
Equation 6 to Section 4.2.1 of Appendix A
[GRAPHIC] [TIFF OMITTED] TR19DE24.014
* * * * *
0
5. Amend appendix B to part 58 by revising section 4(b)(5) and (c) and
equation 6 in section 4.2.1 to read as follows:
Appendix B to Part 58--Quality Assurance Requirements for Prevention of
Significant Deterioration (PSD) Air Monitoring
* * * * *
4. * * *
(b) * * *
(5) PM<INF>2.5</INF>: 2 [micro]g/m\3\.
(c) The PM<INF>2.5</INF> 2 [micro]g/m\3\ limit for the
PM<INF>2.5</INF>-PEP may be superseded by mutual agreement between
the PSD PQAO and the PSD reviewing authority as specified in section
3.2.4 of this appendix and detailed in the approved QAPP.
* * * * *
4.2.1 * * *
Equation 6 to Section 4.2.1 of Appendix B
[GRAPHIC] [TIFF OMITTED] TR19DE24.015
* * * * *
0
6. Amend appendix C to part 58 by:
0
a. Revising section 2.2.2; and
0
b. Removing and reserving sections 2.4.2 through 2.4.6; and
0
c. Revising sections 2.7.1, 2.7.4, 2.7.6, 2.8.1, 2.8.5, and 3.1.
The revisions read as follows:
Appendix C to Part 58--Ambient Air Quality Monitoring Methodology
* * * * *
2.2.2 A request to update a designated methods calibration may
be initiated by the instrument manufacturer of record or the EPA
Administrator. State, local, Tribal, and multijurisdictional
organizations of these entities may work with an instrument
manufacture to update a designated method calibration.
* * * * *
2.7.1 Requests for approval under section 2.2, 2.6.2, or 2.8 of
this appendix must be submitted to: Director, Center for
Environmental Measurement and Modeling, Reference and Equivalent
Methods Designation Program (MD-D205-03), U.S. Environmental
Protection Agency, P.O. Box 12055, Research Triangle Park, North
Carolina 27711.
* * * * *
2.7.4 To the extent that such incorporation by reference
provides data or information required by this section (2.7) or by
section 2.5 or 2.6 of this appendix, independent data or duplicative
information need not be submitted.
* * * * *
2.7.6 If the Administrator determines, on the basis of any
available information, that any of the determinations or statements
on which approval of a request under this section was based are
invalid or no longer valid, or that the requirements of section 2.5
or 2.6, as applicable, have not been met, he/she may withdraw the
approval after affording the person who obtained the approval an
opportunity to submit information and arguments opposing such
action.
* * * * *
2.8.1 Except as otherwise provided in this section, no reference
method or equivalent method may be used in a SLAMS network if it has
been modified in a manner that could significantly alter the
performance characteristics of the method without prior approval by
the Administrator. For purposes of this section, ``alternative
method'' means an analyzer, the use of which has been approved under
section 2.5 or 2.6 of this appendix or some combination thereof.
* * * * *
2.8.5 A temporary modification that could alter the performance
characteristics of a reference or equivalent may be made without
prior approval under this section if the method is not functioning
or is malfunctioning, provided that parts necessary for repair in
accordance with the applicable operation manual cannot be obtained
within 45 days. Unless such temporary modification is later approved
under section 2.8.4 of this appendix, the temporarily modified
method shall be repaired in accordance with the applicable operation
manual as quickly as practicable but in no event later than 4 months
after the temporary modification was made, unless an extension of
time is granted by the Administrator. Unless and until the temporary
modification is approved, air quality data obtained with the method
as temporarily modified must be clearly identified as such when
submitted in accordance with Sec. 58.16 and must be accompanied by
a report containing the information specified in section 2.8.3 of
this appendix. A request that the Administrator approve a temporary
modification may be submitted in accordance with sections 2.8.1
through 2.8.4 of this appendix. In such cases, the request will be
considered as if a request for prior approval had been made.
* * * * *
3.1 Methods employed in NCore multipollutant sites used to
measure SO<INF>2</INF>, CO, NO<INF>2</INF>, O<INF>3</INF>,
PM<INF>2.5</INF>, or PM<INF>10-2.5</INF> must be reference or
equivalent methods as defined in Sec. 50.1 of this chapter for any
monitors
[[Page 103656]]
intended for comparison with applicable NAAQS.
* * * * *
0
7. Amend appendix E to part 58 by revising table E-3 to section 2.7 and
table E-6 to section 3.8 to read as follows:
Appendix E to Part 58--Probe and Monitoring Path Siting Criteria for
Ambient Air Quality Monitoring
* * * * *
2.7 * * *
Table E-3 to Section 2.7 of Appendix E--Summary of Probe Siting Criteria
--------------------------------------------------------------------------------------------------------------------------------------------------------
Horizontal or
Height from vertical distance Distance from
ground to from supporting drip line of Distance from roadways to
Pollutant Scale \9\ probe \8\ structures \1\ trees to probe probe \8\ (meters)
(meters) \8\ to probe \8\ (meters)
inlet (meters)
--------------------------------------------------------------------------------------------------------------------------------------------------------
SO2 \2\ \3\ \4\ \5\..................... Middle, Neighborhood, Urban, 2.0-15 >=1.0 >=10 N/A.
and Regional.
CO \3\ \4\ \6\.......................... Micro [downtown or street 2.5-3.5 >=1.0 >=10 2.0-10 for downtown areas
canyon sites]. or street canyon
microscale.
CO \3\ \4\ \6\.......................... Micro [Near-Road sites]........ 2.0-7.0 >=1.0 >=10 <=50 for near-road
microscale.
CO \3\ \4\ \6\.......................... Middle and Neighborhood........ 2.0-15 >=1.0 >=10 See Table E-2 of this
appendix for middle and
neighborhood scales.
O3 \2\ \3\ \4\.......................... Middle, Neighborhood, Urban, 2.0-15 >=1.0 >=10 See Table E-1 of this
and Regional. appendix.
NO2 \2\ \3\ \4\......................... Micro.......................... 2.0-7.0 >=1.0 >=10 <=50 for near-road micro-
scale.
NO2 \2\ \3\ \4\......................... Middle, Neighborhood, Urban, 2.0-15 >=1.0 >=10 See Table E-1 of this
and Regional. appendix.
PAMS \2\ \3\ \4\ Ozone precursors....... Neighborhood and Urban......... 2.0-15 >=1.0 >=10 See Table E-1 of this
appendix.
PM, Pb \2\ \3\ \4\ \7\.................. Micro.......................... 2.0-7.0 >=2.0 (horizontal >=10 See Figure E-1 of this
distance only) appendix.
PM, Pb \2\ \3\ \4\ \7\.................. Middle, Neighborhood, Urban and 2.0-15 >=2.0 (horizontal >=10 See Figure E-1 of this
Regional. distance only) appendix.
--------------------------------------------------------------------------------------------------------------------------------------------------------
N/A--Not applicable.
\1\ When a probe is located on a rooftop, this separation distance is in reference to walls, parapets, or penthouses located on the roof.
\2\ Should be greater than 20 meters from the dripline of tree(s) and must be 10 meters from the dripline.
\3\ Distance from sampler or probe inlet to obstacle, such as a building, must be at least twice the height the obstacle protrudes above the sampler or
probe inlet. Sites not meeting this criterion may be classified as microscale or middle scale (see paragraphs 2.3(a) and 2.3(c) of this appendix).
\4\ Must have unrestricted airflow in a continuous arc of at least 270 degrees around the probe or sampler; 180 degrees if the probe is on the side of a
building or a wall for street canyon monitoring.
\5\ The probe or sampler should be away from minor sources, such as furnace or incineration flues. The separation distance is dependent on the height of
the minor source emission point(s), the type of fuel or waste burned, and the quality of the fuel (sulfur, ash, or lead content). This criterion is
designed to avoid undue influences from minor sources.
\6\ For microscale CO monitoring sites, the probe must be >=10 meters from a street intersection and preferably at a midblock location.
\7\ Collocated monitor inlets must be within 4.0 meters of each other and at least 2.0 meters apart for flow rates greater than 200 liters/min or at
least 1.0 meter apart for samplers having flow rates less than 200 liters/min to preclude airflow interference, unless a waiver has been granted by
the Regional Administrator pursuant to paragraph 3.3.4.2(c) of appendix A of to this part. For PM2.5, collocated monitor inlet heights should be
within 1.0 meter of each other vertically.
\8\ All distances listed are expressed as having 2 significant figures. When rounding is performed to assess compliance with these siting requirements,
the distance measurements will be rounded such as to retain at least two significant figures.
\9\ See section 1.2 of appendix D to this part for definitions of monitoring scales.
* * * * *
3.8 * * *
Table E-6 to Section 3.8 of Appendix E--Summary of Monitoring Path Siting Criteria
--------------------------------------------------------------------------------------------------------------------------------------------------------
Horizontal or
vertical distance Distance from
Height from from supporting trees to 90% Distance from roadways to
Pollutant Maximum monitoring path length ground to 80% of structures \2\ to of monitoring monitoring path \1\ \8\
\9\ \10\ monitoring path 90% of monitoring path \1\ \8\ (meters)
\1\ \8\ (meters) path \1\ \8\ (meters)
(meters)
--------------------------------------------------------------------------------------------------------------------------------------------------------
SO2 \3\ \4\ \5\ \6\.................... <= 300 m for Middle........... 2.0-15 >=1.0 >=10 N/A.
<= 1.0 km for Neighborhood,
Urban, and Regional.
CO \4\ \5\ \7\......................... <= 300 m for Micro [downtown 2.5-3.5 >=1.0 >=10 2.0-10 for downtown areas
or street canyon sites]. or street canyon
microscale.
CO \4\ \5\ \7\......................... <= 300 m for Micro [Near-Road 2.0-7.0 >=1.0 >=10 <=50 for near-road
sites]. microscale.
CO \4\ \5\ \7\......................... <= 300 m for Middle........... 2.0-15 >=1.0 >=10 See Table E-5.
CO \4\ \5\ \7\......................... <= 1.0 km for Neighborhood.... 2.0-15 >=1.0 >=10 See Table E-5.
O3 \3\ \4\ \5\......................... <= 300 m for Middle........... 2.0-15 >=1.0 >=10 See Table E-4.
O3 \3\ \4\ \5\......................... <= 1.0 km for Neighborhood, 2.0-15 >=1.0 >=10 See Table E-4.
Urban, and Regional.
NO2 \3\ \4\ \5\........................ Between 50 m-300 m for Micro 2.0-7.0 >=1.0 >=10 <=50 for near-road micro-
(Near-Road). scale.
NO2 \3\ \4\ \5\........................ <= 300 m for Middle........... 2.0-15 >=1.0 >=10 See Table E-4 of this
appendix.
NO2 \3\ \4\ \5\........................ <= 1.0 km for Neighborhood, 2.0-15 >=1.0 >=10 See Table E-4 of this
Urban, and Regional. appendix.
[[Page 103657]]
PAMS \3\ \4\ \5\ Ozone precursors...... <= 1.0 km for Neighborhood and 2.0-15 >=1.0 >=10 See Table E-4 of this
Urban. appendix.
--------------------------------------------------------------------------------------------------------------------------------------------------------
N/A--Not applicable.
\1\ Monitoring path for open path analyzers is applicable only to middle or neighborhood scale CO monitoring, middle, neighborhood, urban, and regional
scale NO2 monitoring, and all applicable scales for monitoring SO2, O3, and O3 precursors.
\2\ When the monitoring path is located on a rooftop, this separation distance is in reference to walls, parapets, or penthouses located on roof.
\3\ At least 90 percent of the monitoring path should be greater than 20 meters from the dripline of tree(s) and must be 10-meters from the dripline.
\4\ Distance from 90 percent of monitoring path to obstacle, such as a building, must be at least twice the height the obstacle protrudes above the
monitoring path. Sites not meeting this criterion may be classified as microscale or middle scale (see text).
\5\ Must have unrestricted airflow 270 degrees around at least 90 percent of the monitoring path; 180 degrees if the monitoring path is adjacent to the
side of a building or a wall for street canyon monitoring.
\6\ The monitoring path should be away from minor sources, such as furnace or incineration flues. The separation distance is dependent on the height of
the minor source's emission point (such as a flue), the type of fuel or waste burned, and the quality of the fuel (sulfur, ash, or lead content). This
criterion is designed to avoid undue influences from minor sources.
\7\ For microscale CO monitoring sites, the monitoring path must be >=10. meters from a street intersection and preferably at a midblock location.
\8\ All distances listed are expressed as having 2 significant figures. When rounding is performed to assess compliance with these siting requirements,
the distance measurements will be rounded such as to retain at least two significant figures.
\9\ See section 1.2 of appendix D to this part for definitions of monitoring scales.
\10\ See section 3.7 of this appendix.
* * * * *
[FR Doc. 2024-29223 Filed 12-18-24; 8:45 am]
BILLING CODE 6560-50-P
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