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Environmental Assessment. Washington, DC. U.S. EPA. EPA/600/R-19/
188. December 2019.
U.S. EPA (2019b). PM2.5 Precursor Demonstration Guidance.
Office of Air Quality Planning and Standards, Air Quality Policy
Division. Research Triangle Park, NC. U.S. EPA. EPA-454/R-19-004.
May 2019.
U.S. EPA (2020a). Policy Assessment for the Review of the National
Ambient Air Quality Standards for Particulate Matter. Office of Air
Quality Planning and Standards, Health and Environmental Impacts
Division. Research Triangle Park, NC. U.S. EPA. EPA-452/R-20-002.
January 2020.
U.S. EPA (2020b). Recommendations for Nationwide Approval of
NafionTM Dryers Upstream of UV-Absorption Ozone
Analyzers. Office of Air Quality Planning and Standards, Health and
Environmental Impacts Division. Research Triangle Park, NC. U.S.
EPA. EPA/600/R-20/390. November 2020.
U.S. EPA (2021a). Supplement to the 2019 Integrated Science
Assessment for Particulate Matter (External Review Draft). U.S.
Environmental Protection Agency, Office of Research and Development,
Center for Public Health and Environmental Assessment. Research
Triangle Park, NC. U.S. EPA. EPA/600/R-21/198. December 2019.
U.S. EPA (2021b). Comparative Assessment of the Impacts of
Prescribed Fire Versus Wildfire (CAIF): A Case Study in the Western
U.S. U.S. Environmental Protection Agency. Washington, DC. U.S. EPA.
EPA/600/R-21/197.
U.S. EPA (2021c). Guidance for Ozone and Fine Particulate Matter
Permit Modeling. U.S. Environmental Protection Agency, Office of Air
Quality Planning and Standards, Air Quality Assessment Division.
Research Triangle Park, NC. U.S. EPA. EPA-454/P-21-001. September
2021.
U.S. EPA (2022a). Supplement to the 2019 Integrated Science
Assessment for Particulate Matter (Final Report). U.S. Environmental
Protection Agency, Office of Research and Development, Center for
Public Health and Environmental Assessment. Research Triangle Park,
NC. U.S. EPA. EPA/600/R 22/028. May 2022.
U.S. EPA (2022b). Policy Assessment for the Reconsideration of the
National Ambient Air Quality Standards for Particulate Matter.
Office of Air Quality Planning and Standards, Health and
Environmental Impacts Division. Research Triangle Park, NC. U.S.
EPA. EPA-452/R-22-004. May 2022.
Urch, B, Speck, M, Corey, P, Wasserstein, D, Manno, M, Lukic, KZ,
Brook, JR, Liu, L, Coull, B, Schwartz, J, Gold, DR and Silverman, F
(2010). Concentrated ambient fine particles and not ozone induce a
systemic interleukin-6 response in humans. Inhalation Toxicology
22(3): 210-218.
Van de Hulst, H (1981). Light scattering by small particles. Dover
Publications, Inc. New York.
van Donkelaar, A, Martin, RV, Li, C and Burnett, RT (2019). Regional
estimates of

chemical composition of fine particulate matter using a combined
geoscience-statistical method with information from satellites,
models, and monitors. Environmental Science & Technology 53(5).
Vieira, JL, Guimaraes, GV, de Andre, PA, Cruz, FD, Nascimento
Saldiva, PH and Bocchi, EA (2016a). Respiratory filter reduces the
cardiovascular effects associated with diesel exhaust exposure a
randomized, prospective, double-blind, controlled study of heart
failure: the FILTER-HF trial. JACC: Heart Failure 4(1): 55-64.
Vieira, JL, Guimaraes, GV, de Andre, PA, Nascimento Saldiva, PH and
Bocchi, EA (2016b). Effects of reducing exposure to air pollution on
submaximal cardiopulmonary test in patients with heart failure:
Analysis of the randomized, double-blind and controlled FILTER-HF
trial. International Journal of Cardiology 215: 92-97.
Ward-Caviness, CK, Weaver, AM, Buranosky, M, Pfaff, ER, Neas, LM,
Devlin, RB, Schwartz, J, Di, Q, Cascio, WE and Diaz-Sanchez, D
(2020). Associations between long-term fine particulate matter
exposure and mortality in heart failure patients. Journal of the
American Heart Association 9(6): e012517.
Wei, Y, Wang, Y, Di, Q, Choirat, C, Wang, Y, Koutrakis, P,
Zanobetti, A, Dominici, F and Schwartz, JD (2019). Short term
exposure to fine particulate matter and hospital admission risks and
costs in the Medicare population: time stratified, case crossover
study. BMJ (Clinical Research Edition) 367: l6258.
Wei, Y, Yazdi, MD, Di, Q, Requia, WJ, Dominici, F, Zanobetti, A and
Schwartz, J (2021). Emulating causal dose-response relations between
air pollutants and mortality in the Medicare population.
Environmental Health: A Global Access Science Source 20(1): 53.
WHO (2021). World Health Organization global air quality guidelines:
particulate matter (PM2.5 and PM10), ozone, nitrogen dioxide, sulfur
dioxide and carbon monoxide. World Health Organization. Geneva.
Wu, X, Braun, D, Schwartz, J, Kioumourtzoglou, MA and Dominici, F
(2020). Evaluating the impact of long-term exposure to fine
particulate matter on mortality among the elderly. Science Advances
6(29): eaba5692.
Wyatt, LH, Devlin, RB, Rappold, AG, Case, MW and Diaz-Sanchez, D
(2020). Low levels of fine particulate matter increase vascular
damage and reduce pulmonary function in young healthy adults.
Particle and fibre toxicology 17(1): 1-12.
Yorifuji, T, Kashima, S and Doi, H (2016). Fine-particulate air
pollution from diesel emission control and mortality rates in Tokyo:
a quasi-experimental study. Epidemiology 27(6): 769-778.
Zhang, H and Kondragunta, S (2021). Daily and hourly surface
PM2.5 estimation from satellite AOD. Earth and Space
Science 8(3): e2020EA001599.
Zhang, Z, Wang, J, Kwong, JC, Burnett, RT, van Donkelaar, A, Hystad,
P, Martin, RV, Bai, L, McLaughlin, J and Chen, H (2021). Long-term
exposure to air pollution and mortality in a prospective cohort: The
Ontario Health Study. Environment International 154: 106570.

List of Subjects

40 CFR Part 50

    Environmental protection, Air pollution control, Carbon monoxide,
Lead, Nitrogen dioxide, Ozone, Particulate matter, Sulfur oxides.

40 CFR Part 53

    Environmental protection, Administrative practice and procedure,
Air pollution control, Reporting and recordkeeping requirements.

40 CFR Part 58

    Environmental protection, Administrative practice and procedure,
Air pollution control, Intergovernmental relations, Reporting and
recordkeeping requirements.

Michael S. Regan,
Administrator.

    For the reasons set forth in the preamble, chapter I of title 40 of
the Code of Federal Regulations is proposed to be amended as follows:

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. Add Sec.  50.20 to read as follows:

Sec.  50.20  National primary ambient air quality standards for PM2.5.

    (a) The national primary ambient air quality standards for
PM2.5 are 9.0 to 10.0 micrograms per cubic meter ([mu]g/
m\3\) annual arithmetic mean concentration and 35 [mu]g/m\3\ 24-hour
average concentration measured in the ambient air as PM2.5
(particles with an aerodynamic diameter less than or equal to a nominal
2.5 micrometers) by either:
    (1) A reference method based on appendix L to this part and
designated in accordance with part 53 of this chapter; or
    (2) An equivalent method designated in accordance with part 53 of
this chapter.
    (b) The primary annual PM2.5 standard is met when the
annual arithmetic mean concentration, as determined in accordance with
appendix N to this part, is less than or equal to 9.0 to 10.0 [mu]g/
m\3\.
    (c) The primary 24-hour PM2.5 standard is met when the
98th percentile 24-hour concentration, as determined in accordance with
appendix N to this part, is less than or equal to 35 [mu]g/m\3\.
0
3. Amend appendix K to part 50 as follows:
0
a. In section 1.0 by revising paragraph (b);
0
b. In section 2.3 by adding paragraph (d); and
0
c. In section 3.0 by adding paragraphs (a) and (b).
    The revision and additions read as follows:

Appendix K to Part 50--Interpretation of the National Ambient Air
Quality Standards for Particulate Matter

1.0 General

* * * * *
    (b) The terms used in this appendix are defined as follows:
    Average refers to the arithmetic mean of the estimated number of
exceedances per year, as per section 3.1 of this appendix.
    Collocated monitors refer to two or more air measurement
instruments for the same parameter (e.g., PM10 mass)
operated at the same site location, and whose placement is
consistent with part 53 of this chapter. For purposes of considering
a combined site record in this appendix, when two or more monitors
are operated at the same site, one monitor is designated as the
``primary'' monitor with any additional monitors designated as
``collocated.'' It is implicit in these appendix procedures that the
primary monitor and collocated monitor(s) are all reference or
equivalent methods; however, it is not a requirement that the
primary and collocated monitors utilize the same specific sampling
and analysis method.
    Combined site data record is the data set used for performing
computations in this appendix and represents data for the primary
monitors augmented with data from collocated monitors according to
the procedure specified in section 3.0(a) of this appendix.
    Daily value for PM10 refers to the 24-hour average
concentration of PM10 calculated or measured from
midnight to midnight (local time).
    Exceedance means a daily value that is above the level of the
24-hour standard after rounding to the nearest 10 [mu]g/m\3\ (i.e.,
values ending in 5 or greater are to be rounded up).
    Expected annual value is the number approached when the annual
values from an increasing number of years are averaged, in the
absence of long-term trends in emissions or meteorological
conditions.
    Primary monitors are suitable monitors designated by a state or
local agency in their annual network plan as the default data source
for creating a combined site data record. If there is only one
suitable monitor at a particular site location, then it is presumed
to be a primary monitor.
    Year refers to a calendar year.
* * * * *

2.3 Data Requirements

* * * * *
    (d) 24-hour average concentrations will be computed from
submitted hourly PM10

concentration data for each corresponding day of the year and the
result will be stored in the first, or start, hour (i.e., midnight,
hour `0') of the 24-hour period. A 24-hour average concentration
shall be considered valid if at least 75 percent of the hourly
averages (i.e., 18 hourly values) for the 24-hour period are
available. In the event that fewer than all 24 hourly average
concentrations are available (i.e., fewer than 24 but at least 18),
the 24-hour average concentration shall be computed on the basis of
the hours available using the number of available hours within the
24-hour period as the divisor (e.g., the divisor is 19 if 19 hourly
values are available). 24-hour periods with seven or more missing
hours shall also be considered for computations in this appendix if,
after substituting zero for all missing hourly concentrations, the
resulting 24-hour average daily value exceeds the level of the 24-
hour standard specified in Sec.  50.6 after rounding to the nearest
10 [mu]g/m\3\.
* * * * *

3.0 Computational Equations for the 24-Hour Standards

    (a) All computations shown in this appendix shall be implemented
on a site-level basis. Site level concentration data shall be
processed as follows:
    (1) The default dataset for PM10 mass concentrations
for a site shall consist of the measured concentrations recorded
from the designated primary monitor(s). All daily values produced by
the primary monitor are considered part of the site record.
    (2) If a daily value is not produced by the primary monitor for
a particular day, but a value is available from a single collocated
monitor, then that collocated monitor value shall be considered part
of the combined site data record. If daily value data is available
from two or more collocated monitors, the average of those
collocated values shall be used as the daily value. The data record
resulting from this procedure is referred to as the ``combined site
data record.''
    (b) In certain circumstances, including but not limited to site
closures or relocations, data from two nearby sites may be combined
into a single site data record for the purpose of calculating a
valid design value. The appropriate Regional Administrator may
approve such combinations if the Regional Administrator determines
that the measured concentrations do not differ substantially between
the two sites, taking into consideration factors such as distance
between sites, spatial and temporal patterns in air quality, local
emissions and meteorology, jurisdictional boundaries, and terrain
features.
* * * * *
0
4. Amend appendix L to part 50 by revising section 7.3.4 and adding
section <IP_ADDRESS> to read as follows:

Appendix L to Part 50--Reference Method for the Determination of Fine
Particulate Matter as PM2.5 in the Atmosphere

* * * * *
    7.3.4 Particle size separator. The sampler shall be configured
with one of the three alternative particle size separators described
in this section. One separator is an impactor-type separator (WINS
impactor) described in sections <IP_ADDRESS>, <IP_ADDRESS>, and <IP_ADDRESS> of
this appendix. One alternative separator is a cyclone-type separator
(VSCC\TM\) described in section <IP_ADDRESS> of this appendix. The other
alternative separator is also a cyclone-type separator (TE-
PM2.5C) described in section <IP_ADDRESS> of this appendix.
* * * * *
    <IP_ADDRESS> A second cyclone-type separator is identified as a Tisch
TE-PM2.5C Cyclone particle size separator specified as
part of EPA-designated reference method RFPS-1014-219 and as
manufactured by Tisch Environmental Incorporated, 145 S Miami
Avenue, Village of Cleves, Ohio 45002.
* * * * *
0
5. Amend appendix N to part 50 as follows:
0
a. In section 1.0 by revising paragraph (a); and
0
b. In section 3.0 by adding paragraph (d)(3); and
0
c. In section 4.1 by revising paragraph (a); and
0
d. In section 4.2 by revising paragraph (a).
    The addition and revisions read as follows.

Appendix N to Part 50--Interpretation of the National Ambient Air
Quality Standards for PM2.5

1.0 General

    (a) This appendix explains the data handling conventions and
computations necessary for determining when the national ambient air
quality standards (NAAQS) for PM2.5 are met, specifically
the primary and secondary annual and 24-hour PM2.5 NAAQS
specified in Sec. Sec.  50.7, 50.13, 50.18, and 50.20.
PM2.5 is defined, in general terms, as particles with an
aerodynamic diameter less than or equal to a nominal 2.5
micrometers. PM2.5 mass concentrations are measured in
the ambient air by a Federal Reference Method (FRM) based on
appendix L to this part, as applicable, and designated in accordance
with part 53 of this chapter or by a Federal Equivalent Method (FEM)
designated in accordance with part 53 of this chapter. Only those
FRM and FEM measurements that are derived in accordance with part 58
of this chapter (i.e., that are deemed ``suitable'') shall be used
in comparisons with the PM2.5 NAAQS. The data handling
and computation procedures to be used to construct annual and 24-
hour NAAQS metrics from reported PM2.5 mass
concentrations, and the associated instructions for comparing these
calculated metrics to the levels of the PM2.5 NAAQS, are
specified in sections 2.0, 3.0, and 4.0 of this appendix.
* * * * *

3.0 Requirements for Data Use and Data Reporting for Comparisons With
the NAAQS for PM2.5

* * * * *
    (d) * * *
    (3) In certain circumstances, including but not limited to site
closures or relocations, data from two nearby sites may be combined
into a single site data record for the purpose of calculating a
valid design value. The appropriate Regional Administrator may
approve such site combinations if the Regional Administrator
determines that the measured concentrations do not differ
substantially between the two sites, taking into consideration
factors such as distance between sites, spatial and temporal
patterns in air quality, local emissions and meteorology,
jurisdictional boundaries, and terrain features.
* * * * *

4.1 Annual PM2.5 NAAQS

    (a) Levels of the primary and secondary annual PM2.5
National Ambient Air Quality Standards are specified in Sec. Sec.
50.7, 50.13, 50.18, and 50.20 as applicable.
* * * * *

4.2 Twenty-Four-Hour PM2.5 NAAQS

    (a) Levels of the primary and secondary 24-hour PM2.5
National Ambient Air Quality Standards are specified in Sec. Sec.
50.7, 50.13, 50.18, and 50.20 as applicable.
* * * * *

PART 53--AMBIENT AIR MONITORING REFERENCE AND EQUIVALENT METHODS

0
6. The authority citation for part 53 continues to read as follows:

    Authority: Sec. 301(a) of the Clean Air Act (42 U.S.C. sec.
1857g(a)), as amended by sec. 15(c)(2) of Pub. L. 91-604, 84 Stat.
1713, unless otherwise noted.

Subpart A--General Provisions

0
7. Amend Sec.  53.4 as follows:
0
a. By revising paragraph (a);
0
b. By adding paragraph (b)(7); and
0
c. By revising paragraph (d).
    The revisions and addition read as follows:

Sec.  53.4  Applications for reference or equivalent method
determinations.

    (a) Applications for FRM or FEM determinations and modification
requests of existing designated instruments shall be submitted to:
Director, Center for Environmental Measurement and Modeling, Reference
and Equivalent Methods Designation Program (MD-205-03), U.S.
Environmental Protection Agency, Research Triangle Park, North Carolina
27711 (commercial delivery address: 4930 Old Page Road, Durham, North
Carolina 27703).
* * * * *
    (b) * * *
    (7) All written materials for new FRM and FEM applications and
modification requests must be submitted in English in MS Word format.
For any calibration certificates originally written in a non-English
language, the original non-

English version of the certificate must be submitted to EPA along with
a version of the certificate translated to English. All laboratory and
field data associated with new FRM and FEM applications and
modification requests must be submitted in MS Excel format. All
worksheets in MS Excel must be unprotected to enable full inspection as
part of the application review process.
* * * * *
    (d) For candidate reference or equivalent methods or for designated
instruments that are the subject of a modification request, the
applicant, if requested by EPA, shall provide to EPA a representative
sampler or analyzer for test purposes. The sampler or analyzer shall be
shipped free on board (FOB) destination to Director, Center for
Environmental Measurements and Modeling, Reference and Equivalent
Methods Designation Program (MD D205-03), U.S. Environmental Protection
Agency, 4930 Old Page Road, Durham, North Carolina 27703, scheduled to
arrive concurrently with or within 30 days of the arrival of the other
application materials. This sampler or analyzer may be subjected to
various tests that EPA determines to be necessary or appropriate under
Sec.  53.5(f), and such tests may include special tests not described
in this part. If the instrument submitted under this paragraph (d)
malfunctions, becomes inoperative, or fails to perform as represented
in the application before the necessary EPA testing is completed, the
applicant shall be afforded the opportunity to repair or replace the
device at no cost to the EPA. Upon completion of EPA testing, the
sampler or analyzer submitted under this paragraph (d) shall be
repacked by EPA for return shipment to the applicant, using the same
packing materials used for shipping the instrument to EPA unless
alternative packing is provided by the applicant. Arrangements for, and
the cost of, return shipment shall be the responsibility of the
applicant. The EPA does not warrant or assume any liability for the
condition of the sampler or analyzer upon return to the applicant.
0
8. Amend Sec.  53.8 by revising paragraph (a) to read as follows:

Sec.  53.8  Designation of reference and equivalent methods.

    (a) A candidate method determined by the Administrator to satisfy
the applicable requirements of this part shall be designated as an FRM
or FEM (as applicable) by and upon publication of a notice of the
designation in the Federal Register. Applicants shall not publicly
announce, market, or sell the candidate sampler and analyzer as an
approved FRM or FEM (as applicable) until the Federal Register notice
has been published.
* * * * *
0
9. Amend Sec.  53.14 by revising paragraphs (c)(4), (5), and (6) to
read as follows:

Sec.  53.14  Modification of a reference or equivalent method.

* * * * *
    (c) * * *
    (4) Send notice to the applicant that additional information must
be submitted before a determination can be made and specify the
additional information that is needed (in such cases, the 90-day period
shall commence upon receipt of the additional information).
    (5) Send notice to the applicant that additional tests are
necessary and specify which tests are necessary and how they shall be
interpreted (in such cases, the 90-day period shall commence upon
receipt of the additional test data).
    (6) Send notice to the applicant that additional tests will be
conducted by the Administrator and specify the reasons for and the
nature of the additional tests (in such cases, the 90-day period shall
commence 1 calendar day after the additional tests are completed).
* * * * *
0
10. Revise table A-1 to subpart A of part 53 to read as follows:

  Table A-1 to Subpart A of Part 53--Summary of Applicable Requirements for Reference and Equivalent Methods for Air Monitoring of Criteria Pollutants
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                            Applicable appendix of            Applicable subparts of this part
        Pollutant         Reference or equivalent    Manual or automated        part 50 of this    -----------------------------------------------------
                                                                                chapter            A        B        C        D        E        F
--------------------------------------------------------------------------------------------------------------------------------------------------------
SO2.....................  Reference..............  Manual.................  A-2...................  .......  .......  .......  .......  .......  .......
                                                   Automated..............  A-1...................  [check]  [check]  .......  .......  .......  .......
                          Equivalent.............  Manual.................  A-1...................  [check]  .......  [check]  .......  .......  .......
                                                   Automated..............  A-1...................  [check]  [check]  [check]  .......  .......  .......
CO......................  Reference..............  Automated..............  C.....................  [check]  [check]  .......  .......  .......  .......
                          Equivalent.............  Manual.................  C.....................  [check]  .......  [check]  .......  .......  .......
                                                   Automated..............  C.....................  [check]  [check]  [check]  .......  .......  .......
O3......................  Reference..............  Automated..............  D.....................  [check]  [check]  .......  .......  .......  .......
                          Equivalent.............  Manual.................  D.....................  [check]  .......  [check]  .......  .......  .......
                                                   Automated..............  D.....................  [check]  [check]  [check]  .......  .......  .......
NO2.....................  Reference..............  Automated..............  F.....................  [check]  [check]  .......  .......  .......  .......
                          Equivalent.............  Manual.................  F.....................  [check]  .......  [check]  .......  .......  .......
                                                   Automated..............  F.....................  [check]  [check]  [check]  .......  .......  .......
Pb......................  Reference..............  Manual.................  G.....................  .......  .......  .......  .......  .......  .......
                          Equivalent.............  Manual.................  G.....................  [check]  .......  [check]  .......  .......  .......
                                                   Automated..............  G.....................  [check]  .......  [check]  .......  .......  .......
PM10-Pb.................  Reference..............  Manual.................  Q.....................  .......  .......  .......  .......  .......  .......
                          Equivalent.............  Manual.................  Q.....................  [check]  .......  [check]  .......  .......  .......
                                                   Automated..............  Q.....................  [check]  .......  [check]  .......  .......  .......
PM10....................  Reference..............  Manual.................  J.....................  [check]  .......  .......  [check]  .......  .......
                          Equivalent.............  Manual.................  J.....................  [check]  .......  [check]  [check]  .......  .......
                                                   Automated..............  J.....................  [check]  .......  [check]  [check]  .......  .......
PM2.5...................  Reference..............  Manual.................  L.....................  [check]  .......  .......  .......  [check]  .......
                          Equivalent Class I.....  Manual.................  L.....................  [check]  .......  [check]  .......  [check]  .......
                          Equivalent Class II....  Manual.................  L \1\.................  [check]  .......  [check]  .......  [check]  [check]
                                                                                \2\                     \1\ \2\
                          Equivalent Class III...  Automated..............  L \1\.................  [check]  .......  [check]  .......  [check]  [check]
                                                                                \1\
PM10-2.5................  Reference..............  Manual.................  L, O \2\..............  [check]  .......  .......  .......  [check]  .......

                          Equivalent Class I.....  Manual.................  L, O \2\..............  [check]  .......  [check]  .......  [check]  .......
                          Equivalent Class II....  Manual.................  L, O \2\..............  [check]  .......  [check]  .......  [check]  [check]
                                                                                \2\                     \1\ \2\
                          Equivalent Class III...  Automated..............  L,\1\ O \1\ \2\.......  [check]  .......  [check]  .......  [check]  [check]
                                                                                \1\
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ Some requirements may apply, based on the nature of each particular candidate method, as determined by the Administrator.
\2\ Alternative Class III requirements may be substituted.

Subpart B--Procedures for Testing Performance Characteristics of
Automated Methods for SO2, CO, O3, and NO2

0
11. Amend table B-1 to subpart B of part 53 by revising footnote 4 to
read as follows:

Table B-1 to Subpart B of Part 53--Performance Limit Specifications for
Automated Methods

* * * * *
    \4\ For nitric oxide interference for the SO2
ultraviolet fluorescence (UVF) method, interference equivalent is
0.003 ppm for the lower range.
* * * * *
0
12. Revise table B-3 to subpart B of part 53 to read as follows:

                                                     Table B-3 to Subpart B of Part 53--Interferent Test Concentration,\1\ Parts per Million
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
                                         Hydro-
    Pollutant      Analyzer type \2\     chloric     Ammonia    Hydrogen   Sulfur    Nitrogen   Nitric   Carbon    Ethylene   Ozone   M-xylene    Water     Carbon   Methane   Ethane    Naphth-
                                          acid                  sulfide    dioxide   dioxide    oxide    dioxide                                  vapor    monoxide                       alene
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
SO2.............  Ultraviolet          ..........  ..........    \5\ 0.1  \4\ 0.14        0.5      0.5  ........  .........     0.5        0.2     20,000  ........  .......  ........  \6\ 0.05
                   fluorescence.
SO2.............  Flame photometric..  ..........  ..........       0.01  \4\ 0.14  .........  .......       750  .........  ......  .........        \3\        50  .......  ........  ........
                                                                                20,000
SO2.............  Gas chromatography.  ..........  ..........        0.1  \4\ 0.14  .........  .......       750  .........  ......  .........        \3\        50  .......  ........  ........
                                                                                20,000
SO2.............  Spectrophotometric-         0.2         0.1        0.1  \4\ 0.14        0.5  .......       750  .........     0.5  .........  .........  ........  .......  ........  ........
                   wet chemical
                   (pararosanaline).
SO2.............  Electrochemical....         0.2         0.1        0.1  \4\ 0.14        0.5      0.5  ........        0.2     0.5  .........        \3\  ........  .......  ........  ........
                                                                                20,000
SO2.............  Conductivity.......         0.2         0.1  .........  \4\ 0.14        0.5  .......       750  .........  ......  .........  .........  ........  .......  ........  ........
SO2.............  Spectrophotometric-  ..........  ..........  .........  \4\ 0.14        0.5      0.5  ........  .........     0.5        0.2  .........  ........  .......  ........  ........
                   gas phase,
                   including DOAS.
O3..............  Ethylene             ..........  ..........    \3\ 0.1  ........  .........  .......       750  .........     \4\  .........        \3\  ........  .......  ........  ........
                   Chemiluminescence.                                                                                0.08                20,000
O3..............  NO-                  ..........  ..........    \3\ 0.1  ........        0.5  .......       750  .........     \4\  .........        \3\  ........  .......  ........  ........
                   chemiluminescence.                                                                                0.08                20,000
O3..............  Electrochemical....  ..........     \3\ 0.1  .........       0.5        0.5  .......  ........  .........     \4\  .........        \3\  ........  .......  ........  ........
                                                                                0.08                20,000
O3..............  Spectrophotometric-  ..........     \3\ 0.1  .........       0.5        0.5  \3\ 0.5  ........  .........     \4\  .........  .........  ........  .......  ........  ........
                   wet chemical                                                                                0.08
                   (potassium iodide).
O3..............  Spectrophotometric-  ..........  ..........  .........       0.5        0.5  \3\ 0.5  ........  .........     \4\       0.02     20,000  ........  .......  ........  ........
                   gas phase,                                                                                0.08
                   including
                   ultraviolet
                   absorption and
                   DOAS.
CO..............  Non-dispersive       ..........  ..........  .........  ........  .........  .......       750  .........  ......  .........     20,000    \4\ 10  .......  ........  ........
                   Infrared.
CO..............  Gas chromatography   ..........  ..........  .........  ........  .........  .......  ........  .........  ......  .........     20,000    \4\ 10  .......       0.5  ........
                   with flame
                   ionization
                   detector.
CO..............  Electrochemical....  ..........  ..........  .........  ........  .........      0.5  ........        0.2  ......  .........     20,000    \4\ 10  .......  ........  ........
CO..............  Catalytic            ..........         0.1  .........  ........  .........  .......       750        0.2  ......  .........     20,000    \4\ 10      5.0       0.5  ........
                   combustion-thermal
                   detection.
CO..............  IR fluorescence....  ..........  ..........  .........  ........  .........  .......       750  .........  ......  .........     20,000    \4\ 10  .......       0.5  ........
CO..............  Mercury replacement- ..........  ..........  .........  ........  .........  .......  ........        0.2  ......  .........  .........    \4\ 10  .......       0.5  ........
                   UV photometric.
NO2.............  Chemiluminescent...  ..........     \3\ 0.1  .........       0.5    \4\ 0.1      0.5  ........  .........  ......  .........     20,000  ........  .......  ........  ........
NO2.............  Spectrophotometric-  ..........  ..........  .........       0.5    \4\ 0.1      0.5       750  .........     0.5  .........  .........  ........  .......  ........  ........
                   wet chemical (azo-
                   dye reaction).
NO2.............  Electrochemical....         0.2     \3\ 0.1  .........       0.5    \4\ 0.1      0.5       750  .........     0.5  .........     20,000        50  .......  ........  ........
NO2.............  Spectrophotometric-  ..........     \3\ 0.1  .........       0.5    \4\ 0.1      0.5  ........  .........     0.5  .........     20,000        50  .......  ........  ........
                   gas phase.
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ Concentrations of interferent listed must be prepared and controlled to 10 percent of the stated value.
\2\ Analyzer types not listed will be considered by the Administrator as special cases.
\3\ Do not mix interferent with the pollutant.
\4\ Concentration of pollutant used for test. These pollutant concentrations must be prepared to 10 percent of the stated value.
\5\ If candidate method utilizes an elevated-temperature scrubber for removal of aromatic hydrocarbons, perform this interference test.
\6\ If naphthalene test concentration cannot be accurately quantified, remove the scrubber, use a test concentration that causes a full-scale response, reattach the scrubber, and evaluate
  response for interference.

0
13. Amend appendix A to subpart B of part 53 by revising figures B-3
and B-5 to read as follows:

Appendix A to Subpart B of Part 53--Optional Forms for Reporting Test
Results

* * * * *

Figure B-3 to Appendix A to Subpart B of Part 53--Form for Test Data
and Calculations for Lower Detectable Limit (LDL) and Interference
Equivalent (IE) (see Sec.  53.23(c) and (d))

BILLING CODE 6560-50-P
[GRAPHIC] [TIFF OMITTED] TP27JA23.006

BILLING CODE 6560-50-C
* * * * *

Figure B-5 to Appendix A to Subpart B of Part 53--Form for Calculating
Zero Drift, Span Drift and Precision (see Sec.  53.23(e))
[GRAPHIC] [TIFF OMITTED] TP27JA23.007

* * * * *

Subpart C--Procedures for Determining Comparability Between
Candidate Methods and Reference Methods

0
14. Amend Sec.  53.35 by revising paragraph (b)(1)(ii)(D) to read as
follows:

Sec.  53.35  Test procedure for Class II and Class III methods for
PM2.5 and PM10-2.5.

* * * * *
    (b) * * *
    (1) * * *
    (ii) * * *
    (D) Site D shall be in a large city east of the Mississippi River,
having characteristically high humidity levels.
* * * * *
0
15. Revise table C-4 to subpart C of part 53 to read as follows:

                    Table C-4 to Subpart C of Part 53--Test Specifications for PM10, PM2.5, and PM10-2.5 Candidate Equivalent Methods
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                PM2.5                                            PM10-2.5
          Specification                  PM10       ----------------------------------------------------------------------------------------------------
                                                          Class I             Class II            Class III            Class II            Class III
--------------------------------------------------------------------------------------------------------------------------------------------------------
Acceptable concentration range    5-300............  3-200............  3-200..............  3-200..............  3-200.............  3-200.
 (Rj), [mu]g/m\3\.
Minimum number of test sites....  2................  1................  2..................  4..................  2.................  4.
Minimum number of candidate       3................  3................  \1\ 3..............  \1\ 3..............  \1\ 3.............  \1\ 3.
 method samplers or analyzers
 per site.
Number of reference method        3................  3................  \1\ 3..............  \1\ 3..............  \1\ 3.............  \1\ 3.
 samplers per site.
Minimum number of acceptable
 sample sets per site for PM10
 methods:
    Rj <20 [mu]g/m\3\...........  3................
    Rj >20 [mu]g/m\3\...........  3................
                                 -----------------------------------------------------------------------------------------------------------------------
        Total...................  10...............

Minimum number of acceptable
 sample sets per site for PM2.5
 and PM10-2.5 candidate
 equivalent methods:
    Rj <15 [mu]g/m\3\ for 24-hr   .................  3................  3..................  3..................  3.................  3.
     or Rj <8 [mu]g/m\3\ for 48-
     hr samples.
    Rj>15 [mu]g/m\3\ for 24-hr    .................  3................  3..................  3..................  3.................  3.
     or Rj >8 [mu]g/m\3\ for 48-
     hr samples.
    Each season.................  .................  10...............  23.................  23.................  23................  23.
                                 -----------------------------------------------------------------------------------------------------------------------
        Total, each site........  .................  10...............  23.................  23 (46 for two-      23................  23 (46 for two-
                                                                                season sites).                           season sites).
Precision of replicate reference  5 [mu]g/m\3\ or    2 [mu]g/m\3\ or    10% \2\............  10% \2\............  10% \2\...........  10%.\2\
 method measurements, PRj or       7%.                5%.
 RPRj, respectively; RP for
 Class II or III PM2.5 or PM10-
 2.5, maximum.
Precision of PM2.5 or PM10-2.5    .................  .................  10% \2\............  15% \2\............  15% \2\...........  15%.\2\
 candidate method, CP, each site.
Slope of regression relationship  1 0.10.  1 0.10.  1 0.10  1 0.10.        minus>0.05.                                                                      minus>0.12.
Intercept of regression           0 5..  0 1..  Between: 13.55-      Between: 15.05-      Between: 62.05-     Between: 70.50-
 relationship, [mu]g/m\3\.                                               (15.05 x slope),     (17.32 x slope),     (70.5 x slope),     (82.93 x slope),
                                                                         but not less than-   but not less than-   but not less than-  but not less than-
                                                                         1.5; and 16.56-      2.0; and 15.05-      3.5; and 78.95-     7.0; and 70.50-
                                                                         (15.05 x slope),     (13.20 x slope),     (70.5 x slope),     (61.16 x slope),
                                                                         but not more than    but not more than    but not more than   but not more than
                                                                         +1.5.                +2.0.                +3.5.               +7.0.
                                                                       ---------------------------------------------------------------------------------
Correlation of reference method   >=0.97...........  >=0.97...........  >=0.93--for CCV <=0.4; >=0.85 + 0.2 x CCV--for 0.4 <= CCV <=0.5; >=0.95--for CCV
 and candidate method                                                                                >=0.5.
 measurements.
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ Some missing daily measurement values may be permitted; see test procedure.
\2\ Calculated as the root mean square over all measurement sets.

Subpart D--Procedures for Testing Performance Characteristics of
Methods for PM10

0
16. Amend Sec.  53.43 by revising the formula in paragraph (a)(2)(xvi)
and paragraph (c)(2)(iv) to read as follows:

Sec.  53.43  Test procedures.

    (a) * * *
    (2) * * *
    (xvi) * * *
    [GRAPHIC] [TIFF OMITTED] TP27JA23.008

* * * * *
    (c) * * *
    (2) * * *
    (iv) * * *

[GRAPHIC] [TIFF OMITTED] TP27JA23.009

if Cj is above 80 [mu]g/m\3\.

Subpart E--Procedures for Testing Physical (Design) and Performance
Characteristics of Reference Methods and Class I and Class II
Equivalent Methods for PM2.5 or PM10-2.5

0
17. Amend Sec.  [thinsp]53.51 by revising paragraph (d)(2) to read as
follows:

Sec.  53.51  Demonstration of compliance with design specifications and
manufacturing and test requirements.

* * * * *
    (d) * * *
    (2) VSCC and TE-PM2.5C separators. For samplers and monitors
utilizing the BGI VSCC or Tisch TE-PM2.5C particle size
separators specified in sections <IP_ADDRESS> and <IP_ADDRESS> of appendix L to
part 50 of this chapter, respectively, the respective manufacturers
shall identify the critical dimensions and manufacturing tolerances for
the separator, devise appropriate test procedures to verify that the
critical dimensions and tolerances are maintained during the
manufacturing process, and carry out those procedures on each separator
manufactured to verify conformance of the manufactured products. The
manufacturer shall also maintain records of these tests and their test
results and submit evidence that this procedure is incorporated into
the manufacturing procedure, that the test is or will be routinely
implemented, and that an appropriate procedure is in place for the
disposition of units that fail this tolerance tests.
* * * * *

Subpart F--Procedures for Testing Performance Characteristics of
Class II Equivalent Methods for PM2.5

0
18. Amend Sec.  53.61 by revising the heading of paragraph (g) and
paragraphs (g)(1) introductory text, (g)(1)(i) introductory text, and
(g)(2)(i) and adding paragraph (g)(2)(iii) to read as follows:

 Sec.  53.61   Test conditions.

* * * * *
    (g) Vibrating Orifice Aerosol Generator (VOAG) and Flow-Focusing
Monodisperse Aerosol Generator (FMAG) conventions. * * *
    (1) Particle aerodynamic diameter. The VOAG and FMAG produce near-
monodisperse droplets through the controlled breakup of a liquid jet.
When the liquid solution consists of a non-volatile solute dissolved in
a volatile solvent, the droplets dry to form particles of near-
monodisperse size.
    (i) The physical diameter of a generated spherical particle can be
calculated from the operational parameters of the VOAG and FMAG as:
* * * * *
    (2) * * *
    (i) Solid particle tests performed in this subpart shall be
conducted using particles composed of ammonium fluorescein. For use in
the VOAG or FMAG, liquid solutions of known volumetric concentration
can be prepared by diluting fluorescein powder
(C2OH12O5, FW = 332.31, CAS 2321-07-5)
with aqueous ammonia. Guidelines for preparation of fluorescein
solutions of the desired volume concentration (Cvol) are
presented in Vanderpool and Rubow (1988) (Reference 2 in appendix A to
this subpart). For purposes of converting particle physical diameter to
aerodynamic diameter, an ammonium fluorescein particle density of 1.35
g/cm\3\ shall be used.
* * * * *
    (iii) Calculation of the physical diameter of the particles
produced by the VOAG and FMAG requires knowledge of the liquid
solution's volume concentration (Cvol). Because uranine is
essentially insoluble in oleic acid, the total particle volume is the
sum of the oleic acid volume and the uranine volume. The volume
concentration of the liquid solution shall be calculated as:
Equation 5 to Paragraph (g)(2)(iii)
[GRAPHIC] [TIFF OMITTED] TP27JA23.010

Where:

Vu = uranine volume, ml;
Voleic = oleic acid volume, ml;
Vsol = total solution volume, ml;
Mu = uranine mass, g;
Pu = uranine density, g/cm\3\;
Moleic = oleic acid mass, g; and
Poleic = oleic acid density, g/cm\3\.
* * * * *

PART 58--AMBIENT AIR QUALITY SURVEILLANCE

0
19. 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.

Subpart A--General Provisions

0
20. Amend Sec.  58.1 as follows:
0
a. By removing the definition for ``Approved regional method (ARM)'';
and
0
b. By revising the definition for ``Traceable.''
    The revision reads as follows:

Sec.  [thinsp]58.1  Definitions.

* * * * *

    Traceable means a measurement result from a local standard whereby
the result can be related to the International System of Units (SI)
through a documented unbroken chain of calibrations, each contributing
to the measurement uncertainty. Traceable measurement results must be
compared and certified, either directly or via not more than one
intermediate standard, to a National Institute of Standards and
Technology (NIST)-certified reference standard. Examples include but
are not limited to NIST Standard Reference Material (SRM), NIST-
traceable Reference Material (NTRM), or a NIST-certified Research Gas
Mixture (RGM). Traceability to the SI through other National Metrology
Institutes (NMIs) in addition to NIST is allowed if a Declaration of
Equivalence (DoE) exists between NIST and that NMI.
* * * * *

Subpart B--Monitoring Network

0
21. Amend Sec.  58.10 as follows:
0
a. By revising paragraphs (a)(1) and (b)(10) and (13);
0
b. By adding paragraph (b)(14); and
0
c. By revising paragraph (d).
    The revisions and addition read as follows:

Sec.  58.10  Annual monitoring network plan and periodic network
assessment.

    (a)(1) Beginning July 1, 2007, the state, or where applicable
local, agency shall submit to the Regional Administrator an annual
monitoring network plan which shall provide for the documentation of
the establishment and maintenance of an air quality surveillance system
that consists of a network of SLAMS monitoring stations that can
include FRM and FEM monitors that are part of SLAMS, NCore, CSN, PAMS,
and SPM stations. The plan shall include a statement of whether the
operation of each monitor meets the requirements of appendices A, B, C,
D, and E to this part, where applicable. The Regional Administrator may
require additional information in support of this statement. The annual
monitoring network plan must be made available for public inspection
and comment for at least 30 days prior to submission to the EPA and the
submitted plan shall include and address, as appropriate, any received
comments.
* * * * *
    (b) * * *
    (10) Any monitors for which a waiver has been requested or granted
by the EPA Regional Administrator as allowed for under appendix D or
appendix E to this part. For those monitors where a waiver has been
approved, the annual monitoring network plan shall include the date the
waiver was approved.
* * * * *
    (13) The identification of any PM2.5 FEMs used in the
monitoring agency's network where the data are not of sufficient
quality such that data are not to be compared to the national ambient
air quality standards (NAAQS). For required SLAMS where the agency
identifies that the PM2.5 Class III FEM does not produce
data of sufficient quality for comparison to the NAAQS, the monitoring
agency must ensure that an operating FRM or filter-based FEM meeting
the sample frequency requirements described in Sec.  58.12 or other
Class III PM2.5 FEM with data of sufficient quality is
operating and reporting data to meet the network design criteria
described in appendix D to this part.
    (14) The identification of any site(s) intended to address being
sited in an at-risk community where there are anticipated effects from
sources in the area as required in section 4.7.1(b)(3) of appendix D to
this part. An initial approach to the question of whether any new or
moved sites are needed and to identify the communities in which they
intend to add monitoring for meeting the requirement in this paragraph
(b)(14), if applicable, shall be submitted in accordance with the
requirements of section 4.7.1(b)(3) of appendix D to this part which
includes submission to the EPA Regional Administrator no later than
July 1, 2024. Specifics on the resulting proposed new or moved sites
for PM2.5 network design to address at-risk communities, if
applicable, would need to be detailed in annual monitoring network
plans due to each applicable EPA Regional office no later than July 1,
2025. The plan shall provide for any required sites to be operational
no later than 24 months from date of approval of a plan or January 1,
2027, whichever comes first.
* * * * *
    (d) The state, or where applicable local, agency shall perform and
submit to the EPA Regional Administrator an assessment of the air
quality surveillance system every 5 years to determine, at a minimum,
if the network meets the monitoring objectives defined in appendix D to
this part, whether new sites are needed, whether existing sites are no
longer needed and can be terminated, and whether new technologies are
appropriate for incorporation into the ambient air monitoring network.
The network assessment must consider the ability of existing and
proposed sites to support air quality characterization for areas with
relatively high populations of susceptible individuals (e.g., children
with asthma) and other at-risk populations, and, for any sites that are
being proposed for discontinuance, the effect on data users other than
the agency itself, such as nearby states and tribes or health effects
studies. The state, or where applicable local, agency must submit a
copy of this 5-year assessment, along with a revised annual network
plan, to the Regional Administrator. The assessments are due every five
years beginning July 1, 2010.
* * * * *
0
22. Amend Sec.  58.11 by revising paragraphs (a)(2) and (e) to read as
follows:

Sec.  58.11  Network technical requirements.

    (a) * * *
    (2) Beginning January 1, 2009, state and local governments shall
follow the quality assurance criteria contained in appendix A to this
part that apply to SPM sites when operating any SPM site which uses an
FRM or an FEM and meets the requirements of appendix E to this part,
unless the Regional Administrator approves an alternative to the
requirements of appendix A with respect to such SPM sites because
meeting those requirements would be physically and/or financially
impractical due to physical conditions at the monitoring site and the
requirements are not essential to achieving the intended data
objectives of the SPM site. Alternatives to the requirements of
appendix A may be approved for an SPM site as part of the approval of
the annual monitoring plan, or separately.
* * * * *
    (e) State and local governments must assess data from Class III
PM2.5 FEM monitors operated within their network using the
performance criteria described in table C-4 to subpart C of part 53 of
this chapter, for cases where the data are identified as not of
sufficient comparability to a collocated FRM, and the monitoring agency
requests that the FEM data should not be used in comparison to the
NAAQS. These assessments are required in the monitoring agency's annual
monitoring network plan described in Sec.  58.10(b) for cases where the
FEM is identified as not of sufficient comparability to a collocated
FRM. For these collocated PM2.5 monitors, the performance
criteria apply with the following additional provisions:
    (1) The acceptable concentration range (Rj), [mu]g/m\3\ may include
values down to 0 [mu]g/m\3\.

    (2) The minimum number of test sites shall be at least one;
however, the number of test sites will generally include all locations
within an agency's network with collocated FRMs and FEMs.
    (3) The minimum number of methods shall include at least one FRM
and at least one FEM.
    (4) Since multiple FRMs and FEMs may not be present at each site,
the precision statistic requirement does not apply, even if precision
data are available.
    (5) All seasons must be covered with no more than 36 consecutive
months of data in total aggregated together.
    (6) The key statistical metric to include in an assessment is the
bias (both additive and multiplicative) of the PM2.5
continuous FEM(s) compared to a collocated FRM(s). Correlation is
required to be reported in the assessment, but failure to meet the
correlation criteria, by itself, is not cause to exclude data from a
continuous FEM monitor.
0
23. Amend Sec.  58.12 by revising paragraphs (d)(1) and (3) to read as
follows:

Sec.  58.12  Operating schedules.

* * * * *
    (d) * * *
    (1)(i) Manual PM2.5 samplers at required SLAMS stations
without a collocated continuously operating PM2.5 monitor
must operate on at least a 1-in-3 day schedule unless a waiver for an
alternative schedule has been approved per paragraph (d)(1)(ii) of this
section.
    (ii) For SLAMS PM2.5 sites with both manual and
continuous PM2.5 monitors operating, the monitoring agency
may request approval for a reduction to 1-in-6 day PM2.5
sampling or for seasonal sampling from the EPA Regional Administrator.
Other requests for a reduction to 1-in-6 day PM2.5 sampling
or for seasonal sampling may be approved on a case-by-case basis. The
EPA Regional Administrator may grant sampling frequency reductions
after consideration of factors (including but not limited to the
historical PM2.5 data quality assessments, the location of
current PM2.5 design value sites, and their regulatory data
needs) if the Regional Administrator determines that the reduction in
sampling frequency will not compromise data needed for implementation
of the NAAQS. Required SLAMS stations whose measurements determine the
design value for their area and that are within plus or minus 10
percent of the annual NAAQS, and all required sites where one or more
24-hour values have exceeded the 24-hour NAAQS each year for a
consecutive period of at least 3 years are required to maintain at
least a 1-in-3 day sampling frequency until the design value no longer
meets the criteria in this paragraph (d)(1)(ii) for 3 consecutive
years. A continuously operating FEM PM2.5 monitor satisfies
the requirement in this paragraph (d)(1)(ii) unless it is identified in
the monitoring agency's annual monitoring network plan as not
appropriate for comparison to the NAAQS and the EPA Regional
Administrator has approved that the data from that monitor may be
excluded from comparison to the NAAQS.
    (iii) Required SLAMS stations whose measurements determine the 24-
hour design value for their area and whose data are within plus or
minus 5 percent of the level of the 24-hour PM2.5 NAAQS must
have an FRM or FEM operate on a daily schedule if that area's design
value for the annual NAAQS is less than the level of the annual
PM2.5 standard. A continuously operating FEM or
PM2.5 monitor satisfies the requirement in this paragraph
(d)(1)(iii) unless it is identified in the monitoring agency's annual
monitoring network plan as not appropriate for comparison to the NAAQS
and the EPA Regional Administrator has approved that the data from that
monitor may be excluded from comparison to the NAAQS. The daily
schedule must be maintained until the referenced design values no
longer meets the criteria in this paragraph (d)(1)(iii) for 3
consecutive years.
    (iv) Changes in sampling frequency attributable to changes in
design values shall be implemented no later than January 1 of the
calendar year following the certification of such data as described in
Sec.  58.15.
* * * * *
0
24. Revise Sec.  58.15 to read as follows:

Sec.  58.15  Annual air monitoring data certification.

    (a) The state, or where appropriate local, agency shall submit to
the EPA Regional Administrator an annual air monitoring data
certification letter to certify data collected by FRM and FEM monitors
at SLAMS and SPM sites that meet criteria in appendix A to this part
from January 1 to December 31 of the previous year. The head official
in each monitoring agency, or his or her designee, shall certify that
the previous year of ambient concentration and quality assurance data
are completely submitted to AQS and that the ambient concentration data
are accurate to the best of her or his knowledge, taking into
consideration the quality assurance findings. The annual data
certification letter is due by May 1 of each year.
    (b) Along with each certification letter, the state shall submit to
the Regional Administrator an annual summary report of all the ambient
air quality data collected by FRM and FEM monitors at SLAMS and SPM
sites. The annual report(s) shall be submitted for data collected from
January 1 to December 31 of the previous year. The annual summary
serves as the record of the specific data that is the object of the
certification letter.
    (c) Along with each certification letter, the state shall submit to
the Regional Administrator a summary of the precision and accuracy data
for all ambient air quality data collected by FRM and FEM monitors at
SLAMS and SPM sites. The summary of precision and accuracy shall be
submitted for data collected from January 1 to December 31 of the
previous year.

Subpart C--Special Purpose Monitors

0
25. Amend Sec.  58.20 by revising paragraphs (b) through (e) to read as
follows:

Sec.  58.20  Special purpose monitors (SPM).

* * * * *
    (b) Any SPM data collected by an air monitoring agency using a
Federal reference method (FRM) or Federal equivalent method (FEM) must
meet the requirements of Sec. Sec.  58.11 and 58.12 and appendix A to
this part or an approved alternative to appendix A. Compliance with
appendix E to this part is optional but encouraged except when the
monitoring agency's data objectives are inconsistent with the
requirements in appendix E. Data collected at an SPM using a FRM or FEM
meeting the requirements of appendix A must be submitted to AQS
according to the requirements of Sec.  58.16. Data collected by other
SPMs may be submitted. The monitoring agency must also submit to AQS an
indication of whether each SPM reporting data to AQS monitor meets the
requirements of appendices A and E.
    (c) All data from an SPM using an FRM or FEM which has operated for
more than 24 months are eligible for comparison to the relevant NAAQS,
subject to the conditions of Sec. Sec.  58.11(e) and 58.30, unless the
air monitoring agency demonstrates that the data came from a particular
period during which the requirements of appendix A, appendix C, or
appendix E to this part were not met, subject to review and EPA
Regional Office approval as part of the annual monitoring network plan
described in Sec.  58.10.
    (d) If an SPM using an FRM or FEM is discontinued within 24 months
of start-up, the Administrator will not base

a NAAQS violation determination for the PM2.5 or ozone NAAQS
solely on data from the SPM.
    (e) If an SPM using an FRM or FEM is discontinued within 24 months
of start-up, the Administrator will not designate an area as
nonattainment for the CO, SO2, NO2, or 24-hour
PM10 NAAQS solely on the basis of data from the SPM. Such
data are eligible for use in determinations of whether a nonattainment
area has attained one of these NAAQS.
* * * * *
0
26. Amend appendix A to part 58 as follows:
0
a. By revising section 2.6.1 and adding sections <IP_ADDRESS> and <IP_ADDRESS>;
0
b. By removing section <IP_ADDRESS> and redesignating sections <IP_ADDRESS>,
<IP_ADDRESS>, <IP_ADDRESS>, and <IP_ADDRESS> as sections <IP_ADDRESS>, <IP_ADDRESS>, <IP_ADDRESS>,
and <IP_ADDRESS>, respectively;
0
c. By revising sections <IP_ADDRESS>, 3.2.4, 4.2.1, and 4.2.5; and
0
d. In section 6 by revising References (1), (4), (6), (7), (9), (10),
and (11) and table A-1.
    The revisions and additions read as follows:

Appendix A to Part 58--Quality Assurance Requirements for Monitors Used
in Evaluations of National Ambient Air Quality Standards

* * * * *
    2.6.1 Gaseous pollutant concentration standards (permeation
devices or cylinders of compressed gas) used to obtain test
concentrations for CO, SO2, NO, and NO2 must
be EPA Protocol Gases certified in accordance with one of the
procedures given in Reference 4 of this appendix.
    <IP_ADDRESS> The concentrations of EPA Protocol Gas standards used
for ambient air monitoring must be certified with a 95-percent
confidence interval to have an analytical uncertainty of no more
than 2.0 percent (inclusive) of the certified
concentration (tag value) of the gas mixture. The uncertainty must
be calculated in accordance with the statistical procedures defined
in Reference 4 of this appendix.
    <IP_ADDRESS> Specialty gas producers advertising certification with
the procedures provided in Reference 4 of this appendix and
distributing gases as ``EPA Protocol Gas'' for ambient air
monitoring purposes must adhere to the regulatory requirements
specified in 40 CFR 75.21(g) or not use ``EPA'' in any form of
advertising. Monitoring organizations must provide information to
the EPA on the specialty gas producers they use on an annual basis.
PQAOs, when requested by the EPA, must participate in the EPA
Ambient Air Protocol Gas Verification Program at least once every 5
years by sending a new unused standard to a designated verification
laboratory.
* * * * *
    <IP_ADDRESS> Using audit gases that are verified against the NIST
standard reference methods or special review procedures and
validated per the certification periods specified in Reference 4 of
this appendix (EPA Traceability Protocol for Assay and Certification
of Gaseous Calibration Standards) for CO, SO2, and
NO2 and using O3 analyzers that are verified
quarterly against a standard reference photometer.
* * * * *
    3.2.4 PM2.5 Performance Evaluation Program (PEP) Procedures. The
PEP is an independent assessment used to estimate total measurement
system bias. These evaluations will be performed under the national
performance evaluation program (NPEP) as described in section 2.4 of
this appendix or a comparable program. A prescribed number of
Performance evaluation sampling events will be performed annually
within each PQAO. For PQAOs with less than or equal to five
monitoring sites, five valid performance evaluation audits must be
collected and reported each year. For PQAOs with greater than five
monitoring sites, eight valid performance evaluation audits must be
collected and reported each year. A valid performance evaluation
audit means that both the primary monitor and PEP audit
concentrations are valid and equal to or greater than 2 [mu]g/m3.
Siting of the PEP monitor must be consistent with section <IP_ADDRESS>(c)
of this appendix. However, any horizontal distance greater than 4
meters and any vertical distance greater than one meter must be
reported to the EPA regional PEP coordinator. Additionally for every
monitor designated as a primary monitor, a primary quality assurance
organization must:
* * * * *
    4.2.1 Collocated Quality Control Sampler Precision Estimate for
PM10, PM2.5, and Pb. Precision is estimated via duplicate
measurements from collocated samplers. It is recommended that the
precision be aggregated at the PQAO level quarterly, annually, and
at the 3-year level. The data pair would only be considered valid if
both concentrations are greater than or equal to the minimum values
specified in section 4(c) of this appendix. For each collocated data
pair, calculate ti, using equation 6 to this appendix:

Equation 6 to Appendix A to Part 58
[GRAPHIC] [TIFF OMITTED] TP27JA23.011

Where Xi is the concentration from the primary sampler
and Yi is the concentration value from the audit sampler.
The coefficient of variation upper bound is calculated using
equation 7 to this appendix:

Equation 7 to Appendix A to Part 58
[GRAPHIC] [TIFF OMITTED] TP27JA23.012

Where k is the number of valid data pairs being aggregated, and
X\2\0.1,k-1 is the 10th percentile of a chi-squared
distribution with k-1 degrees of freedom. The factor of 2 in the
denominator adjusts for the fact that each ti is
calculated from two values with error.
* * * * *
    4.2.5 Performance Evaluation Programs Bias Estimate for PM2.5.
The bias estimate is calculated using the PEP audits described in
section 3.2.4. of this appendix. The bias estimator is based on,
si, the absolute difference in concentrations divided by
the square root of the PEP concentration.

Equation 8 to Appendix A to Part 58
[GRAPHIC] [TIFF OMITTED] TP27JA23.013

* * * * *

6. References

    (1) American National Standard Institute--Quality Management
Systems For Environmental Information And Technology Programs--
Requirements With Guidance For Use. ASQ/ANSI E4-2014. February 2014.
Available from ANSI Webstore https://webstore.ansi.org/.
* * * * *
    (4) EPA Traceability Protocol for Assay and Certification of
Gaseous Calibration Standards. EPA-600/R-12/531. May, 2012.
Available from U.S. Environmental Protection Agency, National Risk
Management Research Laboratory, Research

Triangle Park, NC 27711. https://www.epa.gov/nscep.
* * * * *
    (6) List of Designated Reference and Equivalent Methods.
Available from U.S. Environmental Protection Agency, Center for
Environmental Measurements and Modeling, Air Methods and
Characterization Division, MD-D205-03, Research Triangle Park, NC
27711. https://www.epa.gov/amtic/air-monitoring-methods-criteria-pollutants.
    (7) Transfer Standards for the Calibration of Ambient Air
Monitoring Analyzers for Ozone. EPA-454/B-13-004 U.S. Environmental
Protection Agency, Research Triangle Park, NC 27711, October, 2013.
https://www.epa.gov/sites/default/files/2020-09/documents/ozonetransferstandardguidance.pdf.
* * * * *
    (9) Quality Assurance Handbook for Air Pollution Measurement
Systems, Volume 1--A Field Guide to Environmental Quality Assurance.
EPA-600/R-94/038a. April 1994. Available from U.S. Environmental
Protection Agency, ORD Publications Office, Center for Environmental
Research Information (CERI), 26 W. Martin Luther King Drive,
Cincinnati, OH 45268. https://www.epa.gov/amtic/ambient-air-monitoring-quality-assurance#documents.
    (10) Quality Assurance Handbook for Air Pollution Measurement
Systems, Volume II: Ambient Air Quality Monitoring Program Quality
System Development. EPA-454/B-13-003. https://www.epa.gov/amtic/ambient-air-monitoring-quality-assurance#documents.
    (11) National Performance Evaluation Program Standard Operating
Procedures. https://www.epa.gov/amtic/ambient-air-monitoring-quality-assurance#npep.

                 Table A-1 to Appendix A to Part 58--Minimum Data Assessment Requirements for NAAQS Related Criteria Pollutant Monitors
--------------------------------------------------------------------------------------------------------------------------------------------------------
               Method                   Assessment method           Coverage           Minimum frequency     Parameters reported    AQS assessment type
--------------------------------------------------------------------------------------------------------------------------------------------------------
Gaseous Methods (CO, NO, SO, O):
    One-Point QC for SO2, NO2, O3,   Response check at       Each analyzer.........  Once per 2 weeks \5\.  Audit concentration    One-Point QC.
     CO.                              concentration 0.005-                                                   \1\ and measured
                                      0.08 ppm SO2, NO2,                                                     concentration \2\.
                                      O3, and 0.5 and 5 ppm
                                      CO.
    Annual performance evaluation    See section 3.1.2 of    Each analyzer.........  Once per year........  Audit concentration    Annual PE.
     for SO2, NO2, O3, CO.            this appendix.                                                         \1\ and measured
                                                                                concentration \2\
                                                                                for each level.
    NPAP for SO2, NO2, O3, CO......  Independent Audit.....  20% of sites each year  Once per year........  Audit concentration    NPAP.
                                                                                \1\ and measured
                                                                                concentration \2\
                                                                                for each level.
Particulate Methods:
    Continuous \4\ method--          Collocated samplers...  15%...................  1-in-12 days.........  Primary sampler        No Transaction
     collocated quality control                                                                              concentration and      reported as raw
     sampling PM2.5.                                                                                duplicate sampler      data.
                                                                                concentration \3\.
    Manual method--collocated        Collocated samplers...  15%...................  1-in-12 days.........  Primary sampler        No Transaction
     quality control sampling PM10,                                                                          concentration and      reported as raw
     PM2.5, Pb-TSP, Pb-PM10.                                                                                duplicate sampler      data.
                                                                                concentration \3\.
    Flow rate verification PM10      Check of sampler flow   Each sampler..........  Once every month \5\.  Audit flow rate and    Flow Rate
     (low Vol) PM2.5, Pb-PM10.        rate.                                                                  measured flow rate     Verification.
                                                                                indicated by the
                                                                                sampler.
    Flow rate verification PM10      Check of sampler flow   Each sampler..........  Once every quarter     Audit flow rate and    Flow Rate
     (High-Vol), Pb-TSP.              rate.                                           \5\.                   measured flow rate     Verification.
                                                                                indicated by the
                                                                                sampler.
    Semi-annual flow rate audit      Check of sampler flow   Each sampler..........  Once every 6 months    Audit flow rate and    Semi Annual Flow Rate
     PM10, TSP, PM10-2.5, PM2.5, Pb-  rate using                                      \5\.                   measured flow rate     Audit.
     TSP, Pb-PM10.                    independent standard.                                                  indicated by the
                                                                                sampler.
    Pb analysis audits Pb-TSP, Pb-   Check of analytical     Analytical............  Once each quarter \5\  Measured value and     Pb Analysis Audits.
     PM10.                            system with Pb audit                                                   audit value (ug Pb/
                                      strips/filters.                                                        filter) using AQS
                                                                                unit code 077.
    Performance Evaluation Program   Collocated samplers...  (1) 5 valid audits for  Distributed over all   Primary sampler        PEP.
     PM2.5.                                                   primary QA orgs, with   4 quarters \5\.        concentration and
                                                              <=5 sites.                                     performance
                                                             (2) 8 valid audits for                          evaluation sampler
                                                              primary QA orgs, with                          concentration.
                                                              >5 sites.
                                                             (3) All samplers in 6
                                                              years.
    Performance Evaluation Program   Collocated samplers...  (1) 1 valid audit and   Distributed over all   Primary sampler        PEP.
     Pb-TSP, Pb-PM10.                                         4 collocated samples    4 quarters \5\.        concentration and
                                                              for primary QA orgs,                           performance
                                                              with <=5 sites.                                evaluation sampler
                                                             (2) 2 valid audits and                          concentration.
                                                              6 collocated samples                           Primary sampler
                                                              for primary QA orgs                            concentration and
                                                              with >5 sites.                                 duplicate sampler
                                                                                concentration.
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ Effective concentration for open path analyzers.
\2\ Corrected concentration, if applicable for open path analyzers.
\3\ Both primary and collocated sampler values are reported as raw data.
\4\ PM2.5 is the only particulate criteria pollutant requiring collocation of continuous and manual primary monitors.
\5\ EPA's recommended maximum number of days that should exist between checks to ensure that the checks are routinely conducted over time and to limit
  data impacts resulting from a failed check.

* * * * *
0
27. Amend appendix B to part 58 as follows:
0
a. By revising section 2.6.1 and adding sections <IP_ADDRESS> and <IP_ADDRESS>;

0
b. By removing and reserving section <IP_ADDRESS>;
0
c. By revising sections <IP_ADDRESS> and 3.2.4;
0
d. By adding sections <IP_ADDRESS> through <IP_ADDRESS>;
0
e. By revising sections 4.2.1, and 4.2.5; and
0
f. In section 6 by revising References (1), (4), (6), (7), (9), (10),
and (11) and table B-1.
    The revisions and additions read as follows:

Appendix B to Part 58--Quality Assurance Requirements for Prevention of
Significant Deterioration (PSD) Air Monitoring

* * * * *
    2.6.1 Gaseous pollutant concentration standards (permeation
devices or cylinders of compressed gas) used to obtain test
concentrations for CO, SO2, NO, and NO2 must
be EPA Protocol Gases certified in accordance with one of the
procedures given in Reference 4 of this appendix.
    <IP_ADDRESS> The concentrations of EPA Protocol Gas standards used
for ambient air monitoring must be certified with a 95-percent
confidence interval to have an analytical uncertainty of no more
than 2.0 percent (inclusive) of the certified
concentration (tag value) of the gas mixture. The uncertainty must
be calculated in accordance with the statistical procedures defined
in Reference 4 of this appendix.
    <IP_ADDRESS> Specialty gas producers advertising certification with
the procedures provided in Reference 4 of this appendix and
distributing gases as ``EPA Protocol Gas'' for ambient air
monitoring purposes must adhere to the regulatory requirements
specified in 40 CFR 75.21(g) or not use ``EPA'' in any form of
advertising. The PSD PQAOs must provide information to the PSD
reviewing authority on the specialty gas producers they use (or will
use) for the duration of the PSD monitoring project. This
information can be provided in the QAPP or monitoring plan, but must
be updated if there is a change in the specialty gas producers used.
* * * * *
    <IP_ADDRESS> Using audit gases that are verified against the NIST
standard reference methods or special review procedures and
validated per the certification periods specified in Reference 4 of
this appendix (EPA Traceability Protocol for Assay and Certification
of Gaseous Calibration Standards) for CO, SO2, and
NO2 and using O3 analyzers that are verified
quarterly against a standard reference photometer.
* * * * *
    3.2.4 PM2.5 Performance Evaluation Program (PEP) Procedures. The
PEP is an independent assessment used to estimate total measurement
system bias. These evaluations will be performed under the NPEP as
described in section 2.4 of this appendix or a comparable program.
Performance evaluations will be performed annually within each PQAO.
For PQAOs with less than or equal to five monitoring sites, five
valid performance evaluation audits must be collected and reported
each year. For PQAOs with greater than five monitoring sites, eight
valid performance evaluation audits must be collected and reported
each year. A valid performance evaluation audit means that both the
primary monitor and PEP audit concentrations are valid and equal to
or greater than 2 [micro]g/m3. Siting of the PEP monitor must be
consistent with section <IP_ADDRESS>(c) of this appendix. However, any
horizontal distance greater than 4 meters and any vertical distance
greater than one meter must be reported to the EPA regional PEP
coordinator.
    Additionally for every monitor designated as a primary monitor,
a primary quality assurance organization must:
    <IP_ADDRESS> Have each method designation evaluated each year; and,
    <IP_ADDRESS> Have all FRM, FEM, or ARM 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.
    <IP_ADDRESS> Additional information concerning the PEP is contained
in Reference 10 of this appendix. The calculations for evaluating
bias between the primary monitor and the performance evaluation
monitor for PM2.5 are described in section 4.2.5 of this
appendix.
* * * * *
    4.2.1 Collocated Quality Control Sampler Precision Estimate for
PM10, PM2.5, and Pb. Precision is estimated via duplicate
measurements from collocated samplers. It is recommended that the
precision be aggregated at the PQAO level quarterly, annually, and
at the 3-year level. The data pair would only be considered valid if
both concentrations are greater than or equal to the minimum values
specified in section 4(c) of this appendix. For each collocated data
pair, calculate ti, using equation 6 to this appendix:

Equation 6 to Appendix B to Part 58
[GRAPHIC] [TIFF OMITTED] TP27JA23.014

Where Xi is the concentration from the primary sampler
and Yi is the concentration value from the audit sampler.
The coefficient of variation upper bound is calculated using
equation 7 to this appendix:

Equation 7 to Appendix B to Part 58
[GRAPHIC] [TIFF OMITTED] TP27JA23.015

Where k is the number of valid data pairs being aggregated, and
X\2\0.1,k-1 is the 10th percentile of a chi-squared
distribution with k-1 degrees of freedom. The factor of 2 in the
denominator adjusts for the fact that each ti is
calculated from two values with error.
* * * * *
    4.2.5 Performance Evaluation Programs Bias Estimate for PM2.5.
The bias estimate is calculated using the PEP audits described in
section 3.2.4. of this appendix. The bias estimator is based on,
si, the absolute difference in concentrations divided by
the square root of the PEP concentration.

Equation 8 to Appendix B to Part 58
[GRAPHIC] [TIFF OMITTED] TP27JA23.016

* * * * *

6. References

(1) American National Standard Institute--Quality Management Systems
For Environmental Information And Technology Programs--Requirements
With Guidance For Use. ASQ/ANSI E4-2014. February 2014. Available
from ANSI Webstore https://webstore.ansi.org/.
* * * * *
(4) EPA Traceability Protocol for Assay and Certification of Gaseous
Calibration Standards. EPA-600/R-12/531. May, 2012. Available from
U.S. Environmental Protection Agency, National Risk Management
Research Laboratory, Research Triangle Park, NC 27711. https://www.epa.gov/nscep.
* * * * *
(6) List of Designated Reference and Equivalent Methods. Available
from U.S. Environmental Protection Agency, Center for Environmental
Measurements and Modeling, Air Methods and Characterization
Division, MD-D205-03,

Research Triangle Park, NC 27711. https://www.epa.gov/amtic/air-monitoring-methods-criteria-pollutants.
(7) Transfer Standards for the Calibration of Ambient Air Monitoring
Analyzers for Ozone. EPA-454/B-13-004 U.S. Environmental Protection
Agency, Research Triangle Park, NC 27711, October, 2013. https://www.epa.gov/sites/default/files/2020-09/documents/ozonetransferstandardguidance.pdf.
* * * * *
(9) Quality Assurance Handbook for Air Pollution Measurement
Systems, Volume 1--A Field Guide to Environmental Quality Assurance.
EPA-600/R-94/038a. April 1994. Available from U.S. Environmental
Protection Agency, ORD Publications Office, Center for Environmental
Research Information (CERI), 26 W Martin Luther King Drive,
Cincinnati, OH 45268. https://www.epa.gov/amtic/ambient-air-monitoring-quality-assurance#documents.
(10) Quality Assurance Handbook for Air Pollution Measurement
Systems, Volume II: Ambient Air Quality Monitoring Program Quality
System Development. EPA-454/B-13-003. https://www.epa.gov/amtic/ambient-air-monitoring-quality-assurance#documents.
(11) National Performance Evaluation Program Standard Operating
Procedures. https://www.epa.gov/amtic/ambient-air-monitoring-quality-assurance#npep.

               Table B-1 to Appendix B to Part 58--Minimum Data Assessment Requirements for NAAQS Related Criteria Pollutant PSD Monitors
--------------------------------------------------------------------------------------------------------------------------------------------------------
               Method                   Assessment method           Coverage           Minimum frequency     Parameters reported    AQS assessment type
--------------------------------------------------------------------------------------------------------------------------------------------------------
Gaseous Methods (CO, NO2, SO2, O3):
    One-Point QC for SO2, NO2, O3,   Response check at       Each analyzer.........  Once per 2 weeks \5\.  Audit concentration    One-Point QC.
     CO.                              concentration 0.005-                                                   \1\ and measured
                                      0.08 ppm SO2, NO2,                                                     concentration \2\.
                                      O3, & 0.5 and 5 ppm
                                      CO.
    Quarterly performance            See section 3.1.2 of    Each analyzer.........  Once per quarter \5\.  Audit concentration    Annual PE.
     evaluation for SO2, NO2, O3,     this appendix.                                                         \1\ and measured
     CO.                                                                                concentration \2\
                                                                                for each level.
    NPAP for SO2, NO2, O3, CO\3\...  Independent Audit.....  Each primary monitor..  Once per year........  Audit concentration    NPAP.
                                                                                \1\ and measured
                                                                                concentration \2\
                                                                                for each level.
Particulate Methods:
    Collocated sampling PM10,        Collocated samplers...  1 per PSD Network per   Every 6 days or every  Primary sampler        No Transaction
     PM2.5, Pb.                                               pollutant.              3 days if daily        concentration and      reported as raw
                                                                                monitoring required.   duplicate sampler      data.
                                                                                concentration \4\.
    Flow rate verification PM10,     Check of sampler flow   Each sampler..........  Once every month \5\.  Audit flow rate and    Flow Rate
     PM2.5, Pb.                       rate.                                                                  measured flow rate     Verification.
                                                                                indicated by the
                                                                                sampler.
    Semi-annual flow rate audit      Check of sampler flow   Each sampler..........  Once every 6 months    Audit flow rate and    Semi Annual Flow Rate
     PM10, PM2.5, Pb.                 rate using                                      or beginning, middle   measured flow rate     Audit.
                                      independent standard.                           and end of             indicated by the
                                                                                monitoring \5\.        sampler.
    Pb analysis audits Pb-TSP, Pb-   Check of analytical     Analytical............  Each quarter \5\.....  Measured value and     Pb Analysis Audits.
     PM10.                            system with Pb audit                                                   audit value ([mu]g
                                      strips/filters.                                                        Pb/filter) using AQS
                                                                                unit code 077 for
                                                                                parameters: 14129--
                                                                                Pb (TSP) LC FRM/FEM
                                                                                85129--Pb (TSP) LC
                                                                                Non-FRM/FEM.
    Performance Evaluation Program   Collocated samplers...  (1) 5 valid audits for  Over all 4 quarters    Primary sampler        PEP.
     PM2.5 \3\.                                               PQAOs with <5 sites.    \5\.                   concentration and
                                                             (2) 8 valid audits for                          performance
                                                              PQAOs with >5 sites.                           evaluation sampler
                                                             (3) All samplers in 6                           concentration.
                                                              years.
    Performance Evaluation Program   Collocated samplers...  (1) 1 valid audit and   Over all 4 quarters    Primary sampler        PEP.
     Pb \3\.                                                  4 collocated samples    \5\.                   concentration and
                                                              for PQAOs, with <5                             performance
                                                              sites.                                         evaluation sampler
                                                             (2) 2 valid audits and                          concentration.
                                                              6 collocated samples                           Primary sampler
                                                              for PQAOs with >5                              concentration and
                                                              sites.                                         duplicate sampler
                                                                                concentration.
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ Effective concentration for open path analyzers.
\2\ Corrected concentration, if applicable for open path analyzers.
\3\ NPAP, PM2.5, PEP, and Pb-PEP must be implemented if data is used for NAAQS decisions otherwise implementation is at PSD reviewing authority
  discretion.
\4\ Both primary and collocated sampler values are reported as raw data.
\5\ A maximum number of days should be between these checks to ensure the checks are routinely conducted over time and to limit data impacts resulting
  from a failed check.

0
28. Amend appendix C to part 58 as follows:
0
a. By adding sections 2.2 and 2.2.1 through 2.2.19; and
0
b. By removing and reserving sections 2.4, 2.4.1, and <IP_ADDRESS> through
<IP_ADDRESS>.
    The additions reads as follows:

Appendix C to Part 58--Ambient Air Quality Monitoring Methodology

* * * * *
    2.2 PM10, PM2.5, or PM10-2.5
continuous FEMs with existing valid designations may be calibrated
using network data from collocated FRM and continuous FEM data under
the following provisions:
    2.2.1 Data to demonstrate a calibration may include valid data
from State, local, or Tribal air agencies or data collected by
instrument manufacturers in accordance with 40 CFR 53.35 or other
data approved by the Administrator.
    2.2.2 A request to update a designated methods calibration may
be initiated by the

instrument manufacturer of record or the EPA Administrator.
    2.2.3 Requests for approval of an updated PM10,
PM2.5, or PM10-2.5 continuous FEM calibration
must meet the general submittal requirements of section 2.7 of this
appendix.
    2.2.4 Data included in the request should represent a subset of
representative locations where the method is operational. For cases
with a small number of collocated FRMs and continuous FEMs sites, an
updated candidate calibration may be limited to the sites where both
methods are in use.
    2.2.5 Data included in a candidate method updated calibration
may include a subset of sites where there is a large grouping of
sites in one part of the country such that the updated calibration
would be representative of the country as a whole.
    2.2.6 Improvements should be national in scope and ideally
implemented through a firmware change.
    2.2.7 The goal of a change to a methods calibration is to
increase the number of sites meeting measurements quality objectives
of the method as identified in section <IP_ADDRESS> of appendix A to this
part.
    2.2.8 For meeting measurement quality objectives (MQOs), the
primary objective is to meet the bias goal as this statistic will
likely have the most influence on improving the resultant data
collected.
    2.2.9 Precision data are to be included, but so long as
precision data are at least as good as existing network data or meet
the MQO referenced in section 2.2.8 of this appendix, no further
work is necessary with precision.
    2.2.10 Data available to use may include routine primary and
collocated data.
    2.2.11 Audit data may be useful to confirm the performance of a
candidate updated calibration but should not be used as the basis of
the calibration to keep the independence of the audit data.
    2.2.12 Data utilized as the basis of the updated calibration may
be obtained by accessing EPA's AQS database.
    2.2.13 Years of data to use in a candidate method calibration
should include two recent years where we are past the certification
period for the previous year's data, which is May 1st of each year.
    2.2.14 Data from additional years is to be used to test an
updated calibration such that the calibration is independent of the
test years of interest. Data from these additional years need to
minimally demonstrate that a larger number of sites are expected to
meet bias MQO especially at sites near the level of the NAAQS for
the PM indicator of interest
    2.2.15 Outliers may be excluded using routine outlier tests.
    2.2.16 The range of data used in a calibration may include all
data available or alternatively use data in the range from the
lowest measured data available up to 125% of the 24-hour NAAQS for
the PM indicator of interest.
    2.2.17 Other improvements to a PM continuous method may be
included as part of a recommended update so long as appropriate
testing is conducted with input from EPA's Office of Research and
Development (ORD) Reference and Equivalent (R&E) Methods Designation
program.
    2.2.18 EPA encourages early communication by instrument
manufacturers considering an update to a PM method. Instrument
companies should initiate such dialogue by contacting EPA's ORD R&E
Methods Designation program. The contact information for this can be
found at 40 CFR 53.4.
    2.2.19 Manufacturers interested in improving instrument's
performance through an updated factory calibration must submit a
written modification request to EPA with supporting rationale.
Because the testing requirements and acceptance criteria of any
field and/or lab tests can depend upon the nature and extent of the
intended modification, applicants should contact EPA's R&E Methods
Designation program for guidance prior to development of the
modification request.
* * * * *
0
29. Amend appendix D to part 58 by revising sections 1 and 1.1(b), the
introductory text before the table in section 4.7.1(a), and sections
4.7.1(b)(3) and 4.7.2 to read as follows:

Appendix D to Part 58--Network Design Criteria for Ambient Air Quality
Monitoring

* * * * *

1. Monitoring Objectives and Spatial Scales

    The purpose of this appendix is to describe monitoring
objectives and general criteria to be applied in establishing the
required SLAMS ambient air quality monitoring stations and for
choosing general locations for additional monitoring sites. This
appendix also describes specific requirements for the number and
location of FRM and FEM sites for specific pollutants, NCore
multipollutant sites, PM10 mass sites, PM2.5
mass sites, chemically-speciated PM2.5 sites, and
O3 precursor measurements sites (PAMS). These criteria
will be used by EPA in evaluating the adequacy of the air pollutant
monitoring networks.
    1.1 * * *
    (b) Support compliance with ambient air quality standards and
emissions strategy development. Data from FRM and FEM monitors for
NAAQS pollutants will be used for comparing an area's air pollution
levels against the NAAQS. Data from monitors of various types can be
used in the development of attainment and maintenance plans. SLAMS,
and especially NCore station data, will be used to evaluate the
regional air quality models used in developing emission strategies,
and to track trends in air pollution abatement control measures'
impact on improving air quality. In monitoring locations near major
air pollution sources, source-oriented monitoring data can provide
insight into how well industrial sources are controlling their
pollutant emissions.
* * * * *
    4.7.1 * * *
    (a) State, and where applicable local, agencies must operate the
minimum number of required PM2.5 SLAMS sites listed in
table D-5 to this appendix. The NCore sites are expected to
complement the PM2.5 data collection that takes place at
non-NCore SLAMS sites, and both types of sites can be used to meet
the minimum PM2.5 network requirements. The total number
of PM2.5 sites needed to support the basic monitoring
objectives of providing air pollution data to the general public in
a timely manner, support compliance with ambient air quality
standards and emission strategy development, and support for air
pollution research studies will include more sites than the minimum
numbers required in table D-5 to this appendix. Deviations from
these PM2.5 monitoring requirements must be approved by
the EPA Regional Administrator.
* * * * *
    (b) * * *
    (3) For areas with additional required SLAMS, a monitoring
station is to be sited in an at-risk community, particularly where
there are anticipated effects from sources in the area (e.g., a
major port, rail yard, airport, industrial area, or major
transportation corridor).
* * * * *
    4.7.2 Requirement for Continuous PM2.5 Monitoring.
The state, or where appropriate, local agencies must operate
continuous PM2.5 analyzers equal to at least one-half
(round up) the minimum required sites listed in table D-5 to this
appendix. At least one required continuous analyzer in each MSA must
be collocated with one of the required FRM/FEM monitors, unless at
least one of the required FRM/FEM monitors is itself a continuous
FEM monitor in which case no collocation requirement applies. State
and local air monitoring agencies must use methodologies and quality
assurance/quality control (QA/QC) procedures approved by the EPA
Regional Administrator for these required continuous analyzers.
* * * * *
0
30. Revise appendix E to part 58 to read as follows:

Appendix E to Part 58--Probe and Monitoring Path Siting Criteria for
Ambient Air Quality Monitoring

1. Introduction
2. Monitors and Samplers with Probe Inlets
3. Open Path Analyzers
4. Waiver Provisions
5. References

1. Introduction

1.1 Applicability

    (a) This appendix contains specific location criteria applicable
to ambient air quality monitoring probes, inlets, and optical paths
of SLAMS, NCore, PAMS, and other monitor types whose data are
intended to be used to determine compliance with the NAAQS. These
specific location criteria are relevant after the general location
has been selected based on the monitoring objectives and spatial
scale of representation discussed in appendix D to this part.
Monitor probe material and sample residence time requirements are
also included in this appendix. Adherence to these siting criteria
is necessary to ensure the uniform collection of compatible and
comparable air quality data.

    (b) The probe and monitoring path siting criteria discussed in
this appendix must be followed to the maximum extent possible. It is
recognized that there may be situations where some deviation from