Document ID: EPA-HQ-OAR-2004-0018-0687
Agency: epa
Document Type: Rule
Title: Ambient Air Monitoring Regulations: Correcting and Other Amendments
Posted Date: 2007-06-12T04:00Z

[Federal Register: June 12, 2007 (Volume 72, Number 112)]
[Rules and Regulations]               
[Page 32193-32212]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr12jn07-10]                         

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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Parts 53 and 58

[EPA-HQ-OAR-2004-0018; FRL-8308-7]
RIN 2060-AO06

 
Ambient Air Monitoring Regulations: Correcting and Other 
Amendments

AGENCY: Environmental Protection Agency (EPA).

ACTION: Direct final rule.

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SUMMARY: The EPA is taking direct final action on ``Ambient Air 
Monitoring Regulations: Correcting and Other Amendments'' to correct 
and clarify parts of a recent final rule published on October 17, 2006, 
that amended the ambient air monitoring requirements for criteria 
pollutants. These errors included several instances where the wording 
in the preamble and regulatory text were not completely consistent, 
several regulatory text passages that contained some imprecise 
language, two instances of regulatory text omission, an outdated 
address reference, and numerous publication errors in tables and 
equations. EPA is also amending the monitoring rule to allow EPA 
Regional Administrators to approve departures from the minimum number 
of PM10 monitors otherwise specified in the rule.
    The October 17, 2006, final rule revised requirements for reference 
and equivalent method determinations, modified requirements for general 
monitoring network design, and modified other requirements pertaining 
to quality assurance, annual network plans and assessments, data 
reporting, monitoring methodology, and probe and monitor siting 
criteria. All other preamble and regulatory text printed in the October 
17, 2006, final rule is correct.

DATES: This rule is effective on September 10, 2007, without further 
notice, unless EPA receives adverse comment by July 12, 2007. If we 
receive adverse comment, we will publish a timely withdrawal in the 
Federal Register informing the public that some or all of the 
amendments in this rule will not take effect.

ADDRESSES: Submit your comments, identified under Docket ID No. EPA-HQ-
OAR-2004-0018 by one of the following methods:
     http://www.regulations.gov. Follow the on-line instructions for 

submitting comments.
     E-mail: a-and-r-docket@epa.gov.
     Fax: (202) 566-1741.
     Mail: Ambient Air Monitoring Regulations: Correcting and 
Other Amendments, Environmental Protection Agency, Mailcode: 6102T, 
1200 Pennsylvania Avenue, NW., Washington, DC 20460. Please include a 
total of 2 copies.
     Hand Delivery: EPA Docket Center, 1301 Constitution 
Avenue, NW., Room 3334, Washington, DC. Such deliveries are only 
accepted during the Docket's normal hours of operation, and special 
arrangements should be made for deliveries of boxed information.
    Instructions: Direct your comments to Docket ID No. EPA-HQ-OAR-
2004-0018. The EPA's policy is that all comments received will be 
included in the public docket without change and may be made available 
online at: http://www.regulations.gov including any personal information 

provided, unless the comment includes information claimed to be 
Confidential Business Information (CBI) or other information whose 
disclosure is restricted by statute. Do not submit information that you 
consider to be CBI or otherwise protected through http://www.regulations.gov 

or e-mail. The http://www.regulations.gov website is an ``anonymous access'' 

system, which means EPA will not know your identity or contact 
information unless you provide it in the body of your comment. If you 
send an e-mail comment directly to EPA without going through 
http://www.regulations.gov, your e-mail address will be automatically captured 

and included as part of the comment that is placed in the public docket 
and made available on the internet. If you submit an electronic 
comment, EPA recommends that you include your name and other contact 
information in the body of your comment and with any disk or CD-ROM you 
submit. If EPA cannot read your comment due to technical difficulties 
and cannot contact you for clarification, EPA may not be able to 
consider your comment. Electronic files should avoid the use of special 
characters, any form of encryption, and be free of any defects or 
viruses.
    Docket: All documents in the docket are listed in the 
http://www.regulations.gov index. Although listed in the index, some 

information is not publicly available, e.g., CBI or other information 
whose disclosure is restricted by statute. Certain other material, such 
as copyrighted material, will be publicly available only in hard copy. 
Publicly available docket materials are available either electronically 
in http://www.regulations.gov or in hard copy at the Revisions to the Ambient 

Air Monitoring Regulations Docket, EPA/DC, EPA West, Room 3334, 
Constitution Ave., NW., Washington, DC. The Public Reading Room is open 
from 8:30 a.m. to 4:30 p.m., Monday through Friday, excluding legal 
holidays. The telephone number for the Public Reading Room is (202) 
566-1744, and the telephone number for the Air Docket is (202) 566-
1742.

FOR FURTHER INFORMATION CONTACT: Mr. Lewis Weinstock, Air Quality 
Assessment Division (C304-06), Office

[[Page 32194]]

of Air Quality Planning and Standards, U.S. Environmental Protection 
Agency, Research Triangle Park, North Carolina 27711; telephone number: 
(919) 541-3661; fax number: (919) 541-1903; e-mail address: 
weinstock.lewis@epa.gov.

SUPPLEMENTARY INFORMATION:

Table of Contents

I. Why Is EPA Using a Direct Final Rule?
II. Does This Action Apply to Me?
III. Judicial Review
IV. Authority
V. Overview of the October 17, 2006 Rule Changes
VI. This Action
    A. Correction to Special Purpose Monitors
    B. Clarification to Requirement for Collocating Required 
Continuous Fine Particle (PM2.5) Monitors
    C. Clarification to Operating Schedule Requirements for Filter-
Based Manual PM2.5 Samplers
    D. Standard versus Daylight Savings Time Reference
    E. Corrections to Regulatory Text on Particulate Matter 
(PM10) Network Design Criteria
    F. Additional Regional Administrator Flexibility in Applying 
PM10 Minimum Monitoring Requirements
    G. Correction to Division Name and Address Reference
    H. Clarification to Conditions for Waiving Regional 
Administrator Comment Period on Submitted Annual Monitoring Network 
Plans
    I. Typographical Corrections
VII. Statutory and Executive Order Reviews
    A. Executive Order 12866: Regulatory Planning and Review
    B. Paperwork Reduction Act
    C. Regulatory Flexibility Act
    D. Unfunded Mandates Reform Act
    E. Executive Order 13132: Federalism
    F. Executive Order 13175: Consultation and Coordination With 
Indian Tribal Governments
    G. Executive Order 13045: Protection of Children From 
Environmental Health and Safety Risks
    H. Executive Order 12898: Federal Actions To Address 
Environmental Justice in Minority Populations and Low-Income 
Populations
    I. Executive Order 13211: Actions That Significantly Affect 
Energy Supply, Distribution, or Use
    J. National Technology Transfer Advancement Act
    K. Congressional Review Act

I. Why Is EPA Using a Direct Final Rule?

    The EPA is publishing this rule without a prior proposed rule 
because we view this as a non-controversial action and anticipate no 
adverse comment. None of the proposed changes creates additional 
regulatory requirements on affected entities compared to those that 
were promulgated in the final rule that was published in the Federal 
Register on October 17, 2006. However, in the ``Proposed Rules'' 
section of this Federal Register, we are publishing a separate document 
that will serve as the proposed rule to make corrections to the Ambient 
Air Monitoring Regulations if relevant adverse comments are received on 
one or more of the amendments in this direct final rule as described in 
sections VI.A. through VI.I of this preamble. We will not institute a 
second comment period on this action. Any parties interested in 
commenting must do so at this time. For further information about 
commenting on this rule, see the ADDRESSES section of this document. If 
EPA receives relevant adverse comment on one or more of the amendments 
included in this rulemaking, we will publish a timely withdrawal in the 
Federal Register indicating which amendment or amendments we are 
withdrawing. The provisions that are not withdrawn will become 
effective on the date set out above, notwithstanding any relevant 
adverse comment on any other provision.

II. Does This Action Apply to Me?

    Categories and entities potentially regulated by this action 
include:

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                   Category                     NAICS code \1\           Examples of regulated entities
----------------------------------------------------------------------------------------------------------------
Industry......................................          334513  Manufacturer, supplier, distributor, or vendor
                                                        541380   of ambient air monitoring instruments;
                                                                 analytical laboratories or other monitoring
                                                                 organizations that elect to submit an
                                                                 application for a reference or equivalent
                                                                 method determination under 40 CFR part 53.
Federal Government............................          924110  Federal agencies (that conduct ambient air
                                                                 monitoring similar to that conducted by States
                                                                 under 40 CFR part 58 and that wish EPA to use
                                                                 their monitoring data in the same manner as
                                                                 State data) or that elect to submit an
                                                                 application for a reference or equivalent
                                                                 method determination under 40 CFR part 53.
State/territorial/local/tribal government.....          924110  State, territorial, and local air quality
                                                                 management programs that are responsible for
                                                                 ambient air monitoring under 40 CFR part 58 or
                                                                 that elect to submit an application for a
                                                                 reference or equivalent method determination
                                                                 under 40 CFR part 53 or for an approved
                                                                 regional method approved under 40 CFR part 58
                                                                 appendix C. The proposal also may affect Tribes
                                                                 that conduct ambient air monitoring similar to
                                                                 that conducted by States and that wish EPA to
                                                                 use their monitoring data in the same manner as
                                                                 State monitoring data.
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\1\ North American Industry Classification System.

    This table is not intended to be exhaustive, but rather provides a 
guide for readers regarding entities likely to be regulated by this 
action. This table lists the types of entities that EPA is now aware 
could potentially be regulated by this action. Other types of entities 
not listed in the table could also be regulated. To determine whether 
your facility or Federal, State, local, tribal, or territorial agency 
is regulated by this action, you should carefully examine the 
requirements for reference or equivalent method determinations in 40 
CFR part 53, subpart A (General Provisions) and the applicability 
criteria in 40 CFR 51.1 of EPA's requirements for State Implementation 
Plans (SIPs). If you have questions regarding the applicability of this 
action to a particular entity, consult the person listed in the 
preceding FOR FURTHER INFORMATION CONTACT section.

III. Judicial Review

    Under section 307(b)(1) of the Clean Air Act (CAA), judicial review 
of the direct final rule amendments is available only by filing a 
petition for review in the U.S. Court of Appeals for the District of 
Columbia by August 13, 2007. Under section 307(d)(7)(B) of the CAA, 
only an objection to the direct final rule amendments that was raised 
with reasonable specificity during the period for public comment can be 
raised during judicial review. Moreover, under section 307(b)(2) of the 
CAA, the requirements established by the direct final rule amendments 
may not be challenged separately in any civil or criminal proceedings 
brought by EPA to enforce these requirements.

IV. Authority

    The EPA rules for ambient air monitoring are authorized under 
sections 110, 301(a), and 319 of the CAA. Section 110(a)(2)(B) of the 
CAA requires that each SIP provide for the establishment and operation 
of devices,

[[Page 32195]]

methods, systems, and procedures needed to monitor, compile, and 
analyze data on ambient air quality and for the reporting of air 
quality data to EPA. Section 103 authorizes, among others, research and 
investigations relating to the causes, effects, extent, prevention and 
control of air pollution. Section 301(a) of the CAA authorizes EPA to 
develop regulations needed to carry out EPA's mission and establishes 
rulemaking requirements. Uniform criteria to be followed when measuring 
air quality and provisions for daily air pollution index reporting are 
required by CAA section 319.

V. Overview of the October 17, 2006 Rule Changes

    On October 17, 2006 (71 FR 61236), EPA amended the rules for 
ambient air monitoring of criteria pollutants. The rule amendments 
established limited ambient air monitoring requirements for particles 
between 2.5 and 10 micrometers ([mu]m) in diameter 
(PM10-2.5) to support continued research into 
these particles' distribution, sources, and health effects. The rule 
amendments required each State to operate one to three ``NCore'' 
monitoring stations that will take an integrated, multipollutant 
approach to ambient air monitoring. In addition, the rule amendments 
modified the general monitoring network design requirements for minimum 
numbers of ambient air monitors to focus on populated areas with air 
quality problems and to reduce significantly the requirements for 
criteria pollutant monitors that have measured ambient air 
concentrations well below the applicable National Ambient Air Quality 
Standards. The rule amendments also revised certain provisions 
regarding monitoring network descriptions and periodic assessments, 
quality assurance, and data certifications. A number of the amendments 
related specifically to monitoring of fine particles (referring to 
particles less than or equal to 2.5 [mu]m in diameter, 
PM2.5), revising the requirements for reference and 
equivalent method determinations (including specifications and test 
procedures) for fine particle monitors.

VI. This Action

    EPA is taking the following actions:
     Correcting a statement in the regulatory text pertaining 
to the potential comparability of data collected from Special Purpose 
Monitors (SPM) with approved alternative quality assurance plans to the 
National Ambient Air Quality Standards (NAAQS).
     Correcting a statement in the preamble with regard to the 
requirement for collocating required continuous PM2.5 
monitors and clarifying associated regulatory text.
     Clarifying several ambiguous regulatory text passages 
pertaining to operating schedules for manual PM2.5 samplers.
     Correcting a reference regarding standard versus daylight 
savings time.
     Restoring two instances of regulatory text that were 
inadvertently omitted from the network design for monitoring particles 
less than or equal to 10 [mu]m in diameter (PM10).
     Adding authority for the Regional Administrator, 
consistent with the authority that already exists for PM2.5 
and ozone, to allow monitoring agencies to deviate from PM10 
monitoring requirements.
     Updating an organizational address reference within 
regulatory text pertaining to quality assurance requirements.
     Clarifying the conditions when the EPA Regional 
Administrator is not required to offer a public comment opportunity 
prior to approving a State's annual monitoring network plan.
     Correcting numerous typographical errors in tables and 
equations.

A. Correction to Special Purpose Monitors

    The intent of 40 CFR 58.20(c) (published at 71 FR 61302) was to 
describe the conditions when data from an SPM using a Federal reference 
method (FRM), Federal equivalent method (FEM), or Approved Regional 
Method (ARM) which has operated for more than 24 months is eligible for 
comparison to the relevant NAAQS. The rule text states that all data 
from an SPM is eligible for comparison to the relevant NAAQS unless the 
data from the particular monitor came from a period when the 
requirements of appendix A to part 58 (Quality Assurance Requirements 
for SLAMS, SPMs, and PSD Air Monitoring) or an approved alternative, 
appendix C to part 58 (Ambient Air Quality Monitoring Methodology), or 
appendix E to part 58 (Probe and Monitoring Path Siting Criteria for 
Ambient Air Monitoring) were not met in practice. This text does not 
reflect EPA's actual intention. Instead, as discussed in the preamble 
(71 FR 61253), the intention of the October 17, 2006, final rule was 
that if the Regional Administrator approved an alternative quality 
assurance plan in place of the requirements of appendix A to part 58, 
the data from the affected SPM would not be eligible for comparison to 
the relevant NAAQS. The unintentional inclusion in the rule text of the 
phrase ``or an approved alternative'' implied that data from SPMs 
operating during a period when approved alternative quality assurance 
requirements were in effect, rather than appendix A requirements, would 
still be eligible for comparison to the relevant NAAQS.
    The EPA provided the Regional Administrator with the authority to 
approve an alternative to the requirements of appendix A to part 58 
with respect to SPM sites when meeting those requirements would be 
physically and/or financially impractical due to physical conditions at 
the monitoring site and the requirements were not essential to 
achieving the intended data objectives of the SPM site.
    Therefore, EPA is clarifying the regulatory text by deleting the 
aforementioned words referencing alternative quality assurance plans. 
The corrected rule text 40 CFR 58.20(c) reads: ``All data from an SPM 
using an FRM, FEM, or ARM which has operated for more than 24 months is 
eligible for comparison to the relevant NAAQS, subject to the 
conditions of Sec.  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 in practice.''

B. Clarification to Requirement for Collocating Required Continuous 
Fine Particle (PM2.5) Monitors

    The regulatory text in 40 CFR part 58, appendix D (Network Design 
Criteria for Ambient Air Quality Monitoring), section 4.7.2 (71 FR 
61322) describes the minimum requirements for operating continuous 
PM2.5 analyzers.\1\ The text requires States to operate a 
minimum number of continuous PM2.5 analyzers equal to at 
least one-half (round up) the minimum required FRM/FEM/ARM 
PM2.5 sites listed in Table D-5 of appendix D to part 58. At 
least one required FRM/FEM/ARM PM2.5 monitor in each MSA 
must be collocated with a continuous analyzer. For example, if a MSA 
had three required FRM/FEM/ARM PM2.5 monitors, then two 
continuous monitors are required, and at least one of those continuous 
monitors must be collocated (placed at the same site) with one of the 
FRM/FEM/ARM PM2.5 monitors. The second

[[Page 32196]]

required continuous monitor could be collocated with one of the 
remaining two required FRM/FEM/ARM PM2.5 monitors at another 
site, or be located at a separate site based on monitoring objectives. 
The EPA did not intend that the continuous analyzers required under 
section 4.7.2 be required to be collocated with each other.
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    \1\ In 40 CFR part 58 and in this preamble, the terms monitor, 
analyzer, and sampler are sometimes used interchangeably. Monitor is 
the more general term. Most often, analyzer means a self-contained 
monitor which can produce concentration data on-site. Sampler means 
a device that collects a sample (e.g., a filter) which must be 
further processed at an outside laboratory to obtain the 
concentration value.
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    The October 17, 2006, rule text matches our intended meaning. 
However, when referencing this rule requirement in the preamble (71 FR 
61263), EPA incorrectly stated that the collocation requirement was 
adopted to address concerns about whether required continuous monitors 
needed to be collocated with a matching second continuous monitor, and 
that the final rule only required one of all the required 
PM2.5 continuous monitors in each MSA to have ``such a 
collocated match.'' This unintentional statement could be construed as 
a requirement for collocating two continuous monitors with each other, 
in addition to the requirement for collocation with at least one 
required FRM/FEM/ARM monitor, leading to the conclusion that EPA was 
requiring three PM2.5 monitors (two continuous, one filter-
based) at the first required site, subject to the requirements of 
section 4.7.2. Moreover, it was not our intention to require a second 
continuous monitor be sited with an FEM or ARM that itself provides 
continuous data.
    Therefore, EPA is clarifying the regulatory text to make clear the 
intentions described above. The EPA is also clarifying that an 
associated reference to quality assurance/quality control procedures 
refers to the continuous monitoring requirement by adding the words 
``for these required continuous analyzers.'' The corrected provision of 
40 CFR part 58, appendix D, section 4.7.2 now reads: ``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 of this appendix. At least one required 
continuous analyzer in each MSA must be collocated with one of the 
required FRM/FEM/ARM monitors, unless at least one of the required FRM/
FEM/ARM monitors is itself a continuous FEM or ARM 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.''

C. Clarification to Operating Schedule Requirements for Filter-Based 
Manual PM2.5 Samplers

    The regulatory text in 40 CFR 58.12(d) (71 FR 61299) describes the 
required sampling frequency for manual filter-based PM2.5 
samplers. Manual PM2.5 samplers at SLAMS stations must 
operate on at least a 1-in-3 day schedule at sites which do not also 
have a collocated continuously operating PM2.5 monitor. For 
SLAMS PM2.5 sites with both manual and continuous 
PM2.5 monitors operating, other than NCore stations, 
monitoring agencies may request approval from the EPA Regional 
Administrator for a reduction to 1-in-6 day PM2.5 sampling 
or for seasonal sampling. 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 the regulatory data needs of States and EPA. The regulatory 
text provides specific criteria under which a manual PM2.5 
sampler at a SLAMS station cannot be exempted by the Regional 
Administrator from at least 1-in-3 day sampling, and also includes a 
separate provision describing when a daily sampling schedule is 
required. The textual length of 40 CFR 58.12(d)(1) as well as the 
specific wording of certain statements could create difficulty in 
understanding the intended operating schedule requirements for manual 
PM2.5 samplers. Therefore, EPA is clarifying 40 CFR 
58.12(d)(1) as described below.
    The first sentence of 40 CFR 58.12(d)(1) stated that: ``Manual 
PM2.5 samplers at SLAMS stations other than NCore stations 
must operate on at least a 1-in-3 day schedule at sites without a 
collocated continuously operating PM2.5 monitor.'' This 
statement could be construed as meaning that manual PM2.5 
samplers at NCore stations were not required to maintain at least a 1-
in-3 day schedule. The rule in fact does require manual 
PM2.5 samplers at NCore stations to maintain at least a 1-
in-3 day sampling schedule, as later noted in 40 CFR 58.12(d)(2), and 
these samplers are not eligible for sampling frequency relief. 
Therefore, EPA is clarifying the rule text by deleting the phrase 
``other than NCore stations'' from first sentence of 40 CFR 
58.12(d)(1).
    Another potential ambiguity regarding the 1-in-3 day sampling 
frequency provision of 40 CFR 58.12(d)(1) is its geographic 
applicability. Since the regulatory language did not specify that the 
1-in-3 day sampling frequency requirement be applied only in areas in 
which PM2.5 monitoring is required, this requirement could 
be interpreted as applying to any manual PM2.5 sampler 
within a State that recorded the highest design value ``in an area'' 
whether or not any PM2.5 monitors were even required in that 
area according to 40 CFR part 58, appendix D. The EPA is concerned that 
such an interpretation would create a disincentive to monitoring by 
potentially requiring States that operated discretionary SLAMS monitors 
to sample on a 1-in-3 day frequency even though the monitor was in 
excess of minimum monitoring requirements. Therefore, the first 
sentence of 40 CFR 58.12(d)(1)(i) is amended to read: ``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.'' In this rule text, ``required 
SLAMS stations'' refers to minimum monitoring requirements as specified 
in 40 CFR part 58, appendix D, section 4.7. It does not include SPMs; 
therefore SPMs are not required to sample on a 1-in-3 day schedule.
    After stating the 1-in-3 day sampling requirement, the rule text at 
40 CFR 58.12(d)(1)(ii) goes on to allow the Regional Administrator to 
grant a reduction of this schedule to 1-in-6 day for SLAMS 
PM2.5 sites with both manual and continuous PM2.5 
monitors operating. In this context, the rule text contains a 
duplicated reference to SLAMS PM2.5 sites; the second 
reference, ``at SLAMS stations,'' is removed in the corrected rule 
language since the opening part of the sentence already states the 
applicability of the provision to SLAMS PM2.5 sites. The 
text goes on to describe two situations in which a manual 
PM2.5 sampler at a required SLAMS station could not be 
granted sampling frequency relief by the Regional Administrator from 
the minimum 1-in-3 day sampling schedule. In the first situation, the 
phrase: ``Sites that have design values that are within plus or minus 
10 percent of the NAAQS'' could be construed as applying to all sites 
within a particular area that have design values that are within plus 
or minus 10 percent of the NAAQS, when the intention was to apply the 
provision only to the site with the highest value in a particular area 
calculated in accordance with 40 CFR part 50, appendix N 
(Interpretation of the National Ambient Air Quality Standards for 
PM2.5).\2\ In the second

[[Page 32197]]

situation, the phrase: ``and sites where the 24-hour values exceed the 
NAAQS for a period of 3 years are required to maintain at least a 1-in-
3 day sampling frequency'' created ambiguity about whether the 
provision was applicable in situations where a single 24-hour value 
exceeded the NAAQS at a particular site during only 1 or 2 years of a 
3-year period. The EPA's intention was that at least one 24-hour value 
had to exceed the NAAQS in each of the years comprising the 3-year 
period situation for the provision to apply.
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    \2\ EPA notes that the term ``design value'' as defined in the 
final rule (40 CFR part 58.1, 71 FR 61296) is the calculated 
concentration of a pollutant according to the applicable appendix of 
part 50 for the highest monitoring site in an attainment or 
nonattainment area, and that EPA's usage of ``design value'' in the 
rule text was consistent with this definition.
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    Also, the regulatory text could be construed as requiring 1-in-3 
day manual PM2.5 sampling at all sites within a particular 
area that have design values within the plus or minus 10 percent 
criteria, regardless of whether the site is required and regardless of 
the potential availability of continuous PM2.5 FEM or ARM 
monitors which inherently would provide every-day data eligible for 
comparison to the NAAQS. The EPA anticipates the increasing 
availability of approved FEM and ARM methods over the next few years, 
and expects that many such approved continuous monitors will be 
deployed at sites formerly dedicated to manual filter-based FRM or FEM 
PM2.5 samplers, including design value sites subject to the 
plus or minus 10 percent criteria when compared with the 24-hour 
PM2.5 NAAQS. The EPA supports the deployment of approved FEM 
or ARM continuous PM2.5 methods to meet appropriate 
monitoring objectives as such monitors become available, and thus we 
did not intend to require 1-in-3 day sampling utilizing manual 
PM2.5 methods at design value sites, or any other sites, 
where monitoring agencies have deployed an approved continuous FEM or 
ARM.
    The clarified language of the restriction related to being within 
plus or minus 10 percent of the NAAQS now reads: ``Required SLAMS 
stations whose measurements determine the design value for their area 
and that are within plus or minus 10 percent of the NAAQS, and all 
required sites where one or more 24-hour values have exceeded the 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. A continuously 
operating FEM or ARM PM2.5 monitor satisfies this 
requirement.''
    At the end of 40 CFR 58.12(d)(1), EPA specified that manual 
PM2.5 samplers at sites that have a design value within plus 
or minus 5 percent of the daily PM2.5 NAAQS must have an FRM 
or FEM operate on a daily schedule. As with the previously discussed 
phrasing in the context of the 1-in-3 day sampling requirement, this 
text could be construed as applying to all sites within a particular 
area that have design values that are within plus or minus 5 percent of 
the NAAQS, when the intention was to apply the provision only to the 
required SLAMS site with the highest value in a particular area. Also, 
the above described concern regarding the acceptability of continuous 
PM2.5 analyzers applies in the case of this plus or minus 5 
percent criterion, and a similar clarification to the rule text is 
appropriate.
    Therefore, EPA is clarifying 40 CFR 58.12(d)(1) and for purposes of 
clarity is adding subparagraph (iii). It will read: ``Required SLAMS 
sites whose measurements determine the design value for their area and 
that are within plus or minus 5 percent of the daily PM2.5 
NAAQS must have an FRM or FEM operate on a daily schedule. A 
continuously operating FEM or ARM PM2.5 monitor satisfies 
this requirement.''
    The EPA notes that only population-oriented monitors are subject to 
the previously described percent-dependent sampling frequency 
requirements. In 40 CFR 58.30 (Special Considerations for Data 
Comparisons to the NAAQS), sites must be population-oriented to be 
comparable to either the annual or daily PM2.5 NAAQS. By 
implication, design value sites must be NAAQS comparable, therefore 
non-population oriented sites would not be affected by the plus or 
minus 10 percent or plus or minus 5 percent provisions.
    As previously mentioned, EPA is aware that the length of 40 CFR 
58.12(d)(1) creates the potential for ambiguity in the applicability of 
individual provisions related to sampling frequency requirements. To 
clarify the applicability of such provisions, EPA has restructured 40 
CFR 58.12(d)(1) to create distinct paragraphs encompassing the 
previously described amended language applicable to SLAMS sites without 
continuously operating PM2.5 monitors (now numbered 40 CFR 
58.12(d)(1)(i)), SLAMS sites with both manual and continuous 
PM2.5 monitors (now numbered 40 CFR 58.12(d)(1)(ii)), and 
design value sites within plus or minus 5 percent of the daily 
PM2.5 NAAQS (now numbered 40 CFR 58.12(d)(1)(iii)).
    In 40 CFR 58.12(d)(3), manual PM2.5 speciation samplers 
at required Speciation Trends Network (STN) stations are required to 
operate on a 1-in-3 day sampling frequency. The EPA intended the 1-in-3 
day sampling frequency to be a minimum sampling frequency and not to 
imply a prohibition against a more frequent sampling frequency, such as 
a daily sampling frequency, if such a frequency is appropriate for 
specific monitoring objectives. Consistent with the phraseology of 
sampling frequency requirements elsewhere in the regulatory text, EPA 
is correcting the aforementioned phrase to read: ``Manual 
PM2.5 speciation samplers at STN stations must operate on at 
least a 1-in-3 day sampling frequency.''

D. Standard versus Daylight Savings Time Reference

    40 CFR 58.12(e) requires that the operating schedule for 
PM10 samplers must be a 24-hour sampling period taken from 
midnight to midnight (local time) to ensure national consistency. In a 
1999 EPA memorandum,\3\ the use of standard time versus daylight 
savings time is discussed in the context of sample collection for 
particulate matter monitors, concluding with the recommendation that 
monitoring agencies operate their particulate matter sampler clocks on 
standard time to avoid the semi-annual time-shift issues associated 
with conversion between standard time and daylight savings time. 
Monitoring agencies have generally adopted the practice of keeping 
their particulate matter sampler clocks on standard time since the 
issuance of the 1999 memorandum. It was EPA's intention to codify the 
practice of keeping particulate matter clocks on standard time in the 
October 17, 2006, Revisions to the Ambient Monitoring Regulations; 
however, the codifying rule text was inadvertently omitted for 
PM10.\4\ If the aforementioned 40 CFR 58.12(e) reference to 
PM10 operating schedule is left uncorrected, this could 
create inconsistent interpretation of the standard versus daylight 
savings time issue among monitoring agencies causing unnecessary 
confusion in the interpretation of the air quality data.
---------------------------------------------------------------------------

    \3\ ``Use of PM Reference Methods and Daylight Savings Time,'' 
J. David Mobley; Office of Air Quality Planning and Standards, June 
11, 1999. http://www.epa.gov/ttn/amtic/files/ambient/pm25/stdtime.pdf
.

    \4\ The intention to base sampling on local standard time was 
correctly reflected in rule text applicable to PM2.5. 40 
CFR part 50, appendix N (Interpretation of the National Ambient Air 
Quality Standards for PM2.5) reads: ``Daily values for 
PM2.5 refers to the 24-hour average concentrations of 
PM2.5 calculated (averaged from hourly measurements) or 
measured from midnight to midnight (local standard time) that are 
used in NAAQS computations.''
---------------------------------------------------------------------------

    Therefore, EPA is correcting the reference to PM10 
operating schedules in

[[Page 32198]]

40 CFR 58.12(e) to read as follows: ``For PM10 samplers, a 
24-hour sample must be taken from midnight to midnight (local standard 
time) to ensure national consistency.''

E. Corrections to Regulatory Text on Particulate Matter 
(PM10) Network Design Criteria

    In the preamble to the final monitoring rule (71 FR 61240), EPA 
stated an intention to retain the pre-existing minimum monitoring 
network design requirements for PM10, which are based on the 
population of an MSA and its historical PM10 air quality. 
The EPA's intention in finalizing the regulatory text in section 4.6, 
Particulate Matter (PM10) Design Criteria, of 40 CFR part 
58, appendix D (Network Design Criteria for Ambient Air Quality 
Monitoring) (71 FR 61320) was to retain all PM10-relevant 
portions of the pre-existing regulatory text beginning with section 
3.7, Particulate Matter Design Criteria for NAMS (see 62 FR 38820, July 
18, 1997), with only minor changes necessary to maintain consistency of 
monitor type terminology (e.g., to eliminate obsolete references to 
National Air Monitoring Stations (NAMS)). The EPA inadvertently omitted 
several passages from the pre-existing regulatory text in section 3.7 
referencing PM10 network design criteria. If left 
uncorrected, these omissions could lead to misinterpretation of 
PM10 monitoring network design requirements. Three specific 
textual corrections are detailed below.
    First, in Table D-4, PM10 Minimum Monitoring 
Requirements (Number of Stations per MSA), the word ``Approximate'' 
which had appeared in the title of the pre-existing Table 4 was 
omitted. Therefore, in order to retain the earlier language EPA is 
revising the title of Table D-4 to read: ``PM10 Minimum 
Monitoring Requirements (Approximate Number of Stations Per MSA).''
    Second, the first footnote contains some words (``within the ranges 
shown in this table'') that were not part of the corresponding footnote 
to the pre-existing Table 4. Therefore, the first footnote is revised 
to read: ``Selection of urban areas and actual numbers of stations per 
area will be jointly determined by EPA and the State Agency.''
    Third, in paragraph (a) of section 4.6, the regulatory text notes 
that State, and where applicable local, agencies must operate the 
minimum number of required PM10 SLAMS sites listed in Table 
D-4 of appendix D. In the October 17, 2006, rulemaking, EPA intended to 
retain all of the pre-existing regulatory text in the pre-existing 
paragraph 3.7.1 (as last promulgated on July 18, 1997, at 62 FR 38850) 
in new paragraph (a) of new section 4.6, to explain in words the 
flexibility in minimum PM10 monitoring requirements as 
provided in the pre-existing Table 4 which had listed ranges of 
required numbers (rather than a single number) of monitors for each of 
the categories of MSA population and historical PM10 range. 
This regulatory text was inadvertently omitted. Therefore, EPA is 
restoring the omitted text and correcting paragraph (a) of section 4.6 
to read: ``Table D-4 indicates the approximate number of permanent 
stations required in MSAs to characterize national and regional 
PM10 air quality trends and geographical patterns. The 
number of PM10 stations in areas where MSA populations 
exceed 1,000,000 must be in the range from 2 to 10 stations, while in 
low population urban areas, no more than 2 stations are required. A 
range of monitoring stations is specified in Table D-4 because sources 
of pollutants and local control efforts can vary from one part of the 
country to another and, therefore, some flexibility is allowed in 
selecting the actual number of stations in any one locale.''

F. Additional Regional Administrator Flexibility in Applying 
PM10 Minimum Monitoring Requirements

    We are amending the monitoring rule to allow EPA Regional 
Administrators to approve departures from the minimum number of 
PM10 monitors otherwise specified in the rule.
    In the January 17, 2006, proposed monitoring rule (71 FR 2802), EPA 
proposed minimum network design monitoring requirements for 
PM10-2.5. In paragraph (b) of section 4.8.1 of 40 CFR part 
58, appendix D, (Network Design Criteria for Ambient Air Quality 
Monitoring), EPA proposed that modifications from the 
PM10-2.5 monitoring requirements must be approved by the 
Regional Administrator. The proposed regulatory language providing the 
Regional Administrator flexibility to modify the PM10-2.5 
monitoring requirements was consistent with similar language proposed 
for PM2.5 that read: ``Deviations from these 
PM2.5 monitoring requirements must be approved by the EPA 
Regional Administrator'' (71 FR 2801, paragraph (b) of section 4.7.1). 
Similar regulatory language was proposed for ozone monitoring 
requirements (71 FR 2798, paragraph (b) of section 4.1): ``Deviations 
from the above O3 requirements are allowed if approved by 
the EPA Regional Administrator.'' The EPA finalized the Regional 
Administrator authority to modify the PM2.5 and ozone 
monitoring requirements in the October 17, 2006, rule following a 
public comment period in which no adverse comments were received about 
the specific provisions concerning Regional Administrator flexibility 
in applying these regulations.
    The EPA did not adopt the proposed PM10-2.5 minimum 
monitoring network design including the Regional Administrator 
flexibility language. The EPA notes, however, that no adverse comments 
were received specifically addressing the proposed Regional 
Administrator authority to modify PM10-2.5 monitoring 
network requirements although voluminous comment was received on other 
proposed provisions of the PM10-2.5 monitoring network 
design and accompanying suitability test.
    The EPA also proposed and adopted requirements for ``NCore'' 
multipollutant monitoring sites, including a provision allowing the 
Administrator to approve modifications from these requirements. Again, 
no adverse comment was received on this modification provision. 
Finally, specific requirements in the rule for photochemical assessment 
monitoring stations (PAMS) have always been modifiable by the 
Administrator.
    Thus, EPA notes that under the current 40 CFR part 58, appendix D 
network design requirements, PM10 is the only pollutant with 
minimum monitoring requirements not subject to modification based on 
either Administrator or Regional Administrator evaluation and approval. 
Such flexibility, already finalized for ozone and PM2.5, can 
prove useful in particular cases where a State demonstrates that 
meeting the minimum monitoring requirements, for an individual MSA for 
example, may be impractical or contrary to the optimum use of 
monitoring resources.
    The EPA believes it is appropriate to allow the Regional 
Administrator to modify PM10 monitoring requirements, for 
the same reasons such authority was finalized for PM2.5 and 
ozone monitoring requirements. Such authority allows for specific local 
factors and information can be considered in order to make the 
PM10 monitoring network more economical while still meeting 
program data needs. In light of the absence of any comments of concern 
regarding very similar Administrator or Regional Administrator 
authority for other pollutants, we do not expect any adverse comment on 
this action. Therefore, EPA is amending paragraph

[[Page 32199]]

(a) of section 4.6 quoted in the section above and adding the following 
sentence so it now reads: ``Modifications from these PM10 
monitoring requirements must be approved by the Regional 
Administrator.'' See also section VI.E of this preamble for a 
clarifying amendment which also affects section 4.6 of appendix D to 
part 58 by restoring inadvertently omitted text.

G. Correction to Division Name and Address Reference

    The October 17, 2006, final rule provided an address reference in 
paragraph 2.4 of 40 CFR part 58 appendix A, to assist with 
communications regarding the National Performance Evaluation Programs. 
Monitoring agencies were advised to contact either the appropriate EPA 
Regional Quality Assurance (QA) Coordinator at the appropriate EPA 
Regional Office location, or the NPAP Coordinator, Emissions Monitoring 
and Analysis Division (D205-02), U.S. Environmental Protection Agency, 
Research Triangle Park, NC 27711. Due to a reorganization within the 
Office of Air Quality Planning and Standards and subsequent physical 
relocation within the North Carolina facility, the provided address 
mail code (D205-02) is no longer correct for quality assurance related 
communications. Additionally, the Emissions Monitoring and Analysis 
Division has been renamed to the Air Quality Assessment Division, as 
part of the same reorganization. Due to the possibility of future 
address changes, EPA believes a more general reference to quality 
assurance contact information is appropriate for inclusion in 
regulatory language. Updated contact information for all air monitoring 
program leads is maintained on the Ambient Monitoring Technology 
Information Center (AMTIC) Web site http://www.epa.gov/ttn/amtic/contacts.html.
 This website is well publicized and frequently accessed 

by all monitoring agencies; therefore, specific address entries in the 
rule are unnecessary and potentially misleading. Accordingly, EPA is 
amending the regulatory text in paragraph 2.4 to read: ``For 
clarification and to participate, monitoring organizations should 
contact either the appropriate EPA Regional Quality Assurance (QA) 
Coordinator at the appropriate EPA Regional Office location, or the 
NPAP Coordinator at the Air Quality Assessment Division, Office of Air 
Quality Planning and Standards, U.S. Environmental Protection Agency in 
Research Triangle Park, North Carolina.''

H. Clarification to Conditions for Waiving Regional Administrator 
Comment Period on Submitted Annual Monitoring Network Plans

    The regulatory text in 40 CFR 58.10(a)(2) (71 FR 61298) describes 
the approval process for State-submitted annual monitoring network 
plans that propose SLAMS network modifications. Such plans are subject 
to the approval of the Regional Administrator, including a new 
requirement for the Regional Administrator to provide opportunity for 
public comment during the 120-day period allowed for approval or 
disapproval. The rule permits the Regional Administrator to waive the 
separate public comment opportunity if the State or local agency has 
already provided a public comment opportunity on its plan and has made 
no changes to the plan subsequent to that comment opportunity.
    Implied but not explicitly stated in the regulatory language is 
that the Regional Administrator may forgo public comment only if the 
State or local agency submitted the full text of public comments 
received on its annual monitoring network plan to the Regional 
Administrator, because only the availability of such detailed comments 
would make a separate comment period by the Regional Administrator 
redundant.
    The EPA believes that the aforementioned regulatory language should 
be clarified to avoid ambiguity about what situations would require the 
Regional Administrator to provide a public comment opportunity on 
submitted annual monitoring network plans that contain SLAMS network 
modifications. The EPA notes that the clarification does not modify the 
minimum requirements for State and local agencies to make their plans 
available for public inspection for at least 30 days prior to 
submission to EPA.
    Accordingly, the clarified regulatory text in the second sentence 
of 40 CFR 58.10(a)(2) reads: ``If the State or local agency has already 
provided a public comment opportunity on its plan and has made no 
changes subsequent to that comment opportunity, and has submitted the 
received comments together with the plan, the Regional Administrator is 
not required to provide a separate opportunity for comment.''
    Such comments could be transmitted to the Regional Administrator in 
hard-copy or electronic format, and at a minimum, would include all 
relevant information supplied to the State or local agency by the 
commenters. Monitoring agencies would not be expected to provide 
comment summaries or comment responses, although those submissions 
could optionally be provided to the Regional Administrator in addition 
to the actual text of the received comments.

I. Typographical Corrections

    The Federal Register printing of the October 17, 2006, final rule 
contained typographical errors in equations, tables, and figures. These 
errors, as explained below and listed by Federal Register page 
reference and CFR section number, are corrected in this rulemaking.
     71 FR 61284. Subpart C of Part 53--Sec.  53.35(d)(4), 
Calculation of mean concentrations. Equation 12: The ``n'' over the 
summation symbol is replaced with ``m.''
     71 FR 61284. Subpart C of Part 53--Sec.  53.35(e) and 
Sec.  53.35(f), Tests for reference method and candidate method 
precision. Equations 13 and 15: 100% is moved to be outside the square 
root symbol.
     71 FR 61284. Subpart C of Part 53--Sec.  53.35(g), Test 
for additive and multiplicative bias (comparative slope and intercept). 
Equation 17: Left part of equation is changed to be R not 
Rj.
     71 FR 61284. Subpart C of Part 53--Sec.  53.35(h), Tests 
for comparison correlation. Equation 21: Radical sign in the 
denominator is extended to cover both summation signs.
     71 FR 61285. Table C-1 to Subpart C of Part 53, Test 
Concentration Ranges, Number of Measurements Required, and Maximum 
Discrepancy Specification. The four occurrences of ``Total'' in the 
first column are moved to the second column.
     71 FR 61285. Table C-1 to Subpart C of Part 53, Test 
Concentration Ranges, Number of Measurements Required, and Maximum 
Discrepancy Specification. Two entries of ``18'' are moved 3 columns 
left to appear in the ``Second Set'' column rather than as shown in the 
right-most column.
     71 FR 61285. Table C-4 to Subpart C of Part 53--Test 
Specifications for PM10, PM2.5 and 
PM10-2.5 Candidate Equivalent Methods. An erroneous ``R'' 
character in the table title is removed so that the title reads--Test 
Specifications for PM10, PM2.5 and 
PM10-2.5 Candidate Equivalent Methods.
     71 FR 61286. Table C-4 to Subpart C of Part 53--Test 
Specifications for PM10, PM2.5 and 
PM10-2.5 Candidate Equivalent Methods. In the column header 
for the last 2 columns, the ``PM10-2.5'' is corrected to be 
``PM10-2.5''.
     71 FR 61286. Table C-4 to Subpart C of Part 53--Test 
Specifications for PM10, PM2.5 and 
PM10-2.5 Candidate

[[Page 32200]]

Equivalent Methods. The horizontal line under ``Rj > 60 
[mu]g/m3'' in the table is removed.
     71 FR 61286. Table C-4 to Subpart C of Part 53--Test 
Specifications for PM10, PM2.5 and 
PM10-2.5 Candidate Equivalent Methods. In the first column, 
in the ``Precision of replicate reference method measurements * * *'' 
entry, the ``prime'' symbols are removed from ``RPRj'' and 
``PM10-2.5''.
     71 FR 61286. Table C-4 to Subpart C of Part 53--Test 
Specifications for PM10, PM2.5 and 
PM10-2.5 Candidate Equivalent Methods. An unintended period 
is removed at the end of the entry in the last column, Intercept row, 
and at the end of the second footnote.
     71 FR 61286. Table C-4 to Subpart C of Part 53--Test 
Specifications for PM10, PM2.5 and 
PM10-2.5 Candidate Equivalent Methods. Values for 
correlation of reference method and candidate method measurements for 
PM2.5 Class II and III, and PM10-2.5 Class II and 
III are added to all four columns:

 >=0.93 for CCV<=0.4;
 >=0.85 + 0.2xCCV for 0.4<=CCV<=0.5;
 >=0.95 for CCV>=0.5.

     71 FR 61287. Figure C-1 to Subpart C of Part 53--Suggested 
Format for Reporting Test Results for Methods for SO2, CO, 
O3, NO2. Title and the first lines of content are 
repositioned from being section text to being proper parts of Figure C-
1.
     71 FR 61287. Figures C-2 and C-3 to Subpart C of Part 53--
Illustration of the Slope and Intercept Limits for Class II and Class 
III PM2.5 Candidate Equivalent Methods and Illustration of 
the Slope and Intercept Limits for Class II and Class III 
PM10-2.5 Candidate Equivalent Methods. ``PM2.5'' 
is changed to ``PM2.5,'' ``PM10-2.5'' is changed 
to ``PM10-2.5,'' ``[mu]g/m3'' is changed to ``[mu]g/m\3\.'' 
Also, the ``Class II'' and ``Class III'' labels are related by arrows 
to the outline of the hexagons rather than the area inside, to be 
consistent with the title, which indicates ``Acceptance Limits.''
     71 FR 61289. Figure C-4 to Subpart C of Part 53--
Illustration of the Minimum Limits for Correlation Coefficient for 
PM2.5 and PM10-2.5 Class II and III methods. In 
the axes labels, the commas are deleted and the ``r'' and the ``CCV'' 
are placed within parentheses.
     71 FR 61293. Subpart E of Part 53--Sec.  53.58(g), 
Operational field precision and blank test. Equation 26: the symbol 
``C1,j'' is corrected to ``Ci,j.''
     71 FR 61294. Table E-1 to Subpart E of Part 53--Summary of 
Test Requirements for Reference and Class I Equivalent Methods for 
PM2.5 and PM10-2.5. In the 3rd column, row 
identified as ``Sec.  53.56* * *,'' a comma is added after ``16.67 
 5%'' and before ``L/min.''
     71 FR 61294. Table E-1 to Subpart E of Part 53--Summary of 
Test Requirements for Reference and Class I Equivalent Methods for 
PM2.5 and PM10-2.5. In the 3rd column, row 
identified as ``Sec.  53.57* * *,'' one of the two periods at the end 
of item 3 is removed.
     71 FR 61294. Table E-1 to Subpart E of Part 53--Summary of 
Test Requirements for Reference and Class I Equivalent Methods for 
PM2.5 and PM10-2.5. In the fourth column, row 
identified as ``Sec.  53.57* * *,'' item (c) is changed to read ``Solar 
flux of 1000  50 W/m\2\'' not ``Solar flux of 1000 ? 50 W/
m\2\.''
     71 FR 61294. Table E-1 to Subpart E of Part 53--Summary of 
Test Requirements for Reference and Class I Equivalent Methods for 
PM2.5 and PM10-2.5. Spurious ``?'' characters 
throughout the table are removed.
     71 FR 61294. Table E-1 to Subpart E of Part 53--Summary of 
Test Requirements for Reference and Class I Equivalent Methods for 
PM2.5 and PM10-2.5. Sec.  53.56 cell reference, 
Barometric pressure effect test, Sample flow rate performance 
specification, value is changed to be 16.67 (versus 16.6).
     71 FR 61296. Table F-1 to Subpart F of Part 53--
Performance Specifications for PM2.5 Class II Equivalent 
Samplers. In the last column, row identified as ``Sec.  53.64,'' 
``Dp50 = 2.5 [mu]m ? 0.2 [mu]m'' is changed to be 
``Dp50 = 2.5 [mu]m  0.2 [mu]m.''
     71 FR 61296. Table F-1 to Subpart F of Part 53--
Performance Specifications for PM2.5 Class II Equivalent 
Samplers. In the last column, last row, a comma is added after 
``0.15mg'' and before ``r >=0.97.''
     71 FR 61296. Table F-1 to Subpart F of Part 53--
Performance Specifications for PM2.5 Class II Equivalent 
Samplers. Spurious ``?'' characters throughout the table are removed.
     71 FR 61300. Figure 1 to Subpart B of Part 58--Ratio to 
Standard for PM10 Operating Schedule. A missing value (1.4) 
is added on the X axis.
     71 FR 61309. Appendix A of Part 58--Quality Assurance 
Requirements for SLAMS, SPMs, and PSD Air Monitoring. Equation 7: A 
missing ``'' character is added so that the equation reads: 
Lower Probability Limit = m-1.96  S.
     71 FR 61309. Appendix A of Part 58--Quality Assurance 
Requirements for SLAMS, SPMs, and PSD Air Monitoring. A missing minus 
sign is added in caption below Equation 11 so that it reads: a chi-
squared distribution with n-1 degrees of freedom.
     71 FR 61310. Appendix A of Part 58--Quality Assurance 
Requirements for SLAMS, SPMs, and PSD Air Monitoring. Equation 12: 
missing ellipsis is added in caption so that it reads: where, 
nj is the number of pairs and d1, d2, 
* * * dnj are the biases for each of the pairs to be 
averaged.
     ``PM10C'', where it appears in Part 53 without 
a subscripted ``C'', is replaced with ``PM10c.''

VII. Statutory and Executive Order Reviews

A. Executive Order 12866: Regulatory Planning and Review

    Under Executive Order 12866 (58 FR 51735, October 4, 1993), this 
action is a ``significant regulatory action'' because it may raise 
novel legal policy issues arising out of legal mandates, the 
President's priorities, or the principles set forth in the Executive 
Order. Accordingly, EPA submitted this action to the Office of 
Management and Budget (OMB) for review under Executive Order 12866 and 
any changes made in response to OMB recommendations have been 
documented in the docket for this action.

B. Paperwork Reduction Act

    This action does not impose any new information collection, as it 
only corrects printing errors, provides clarifications, and provides 
new flexibility for PM10 monitoring on a case-by-case basis. 
However, the OMB has previously approved the information collection 
requirements contained in the existing regulations for 40 CFR part 53 
and 40 CFR part 58 under the provisions of the Paperwork Reduction Act, 
44 U.S.C. 3501 et seq., and has assigned OMB control number 2060-0084, 
EPA ICR number 0940.20. A copy of the OMB approved Information 
Collection Request (ICR) may be obtained from Susan Auby, Collection 
Strategies Division, U.S. Environmental Protection Agency (2822T), 1200 
Pennsylvania Ave., NW., Washington, DC 20460 or by calling (202) 566-
1672. This action does not impose any new information collection burden 
beyond the already-approved ICR.
    Burden means the total time, effort, or financial resources 
expended by persons to generate, maintain, retain, or disclose or 
provide information to or for a Federal agency. This includes the time 
needed to review instructions; develop, acquire, install, and utilize 
technology and systems for the purposes of collecting, validating, and 
verifying

[[Page 32201]]

information, processing and maintaining information, and disclosing and 
providing information; adjust the existing ways to comply with any 
previously applicable instructions and requirements; train personnel to 
be able to respond to a collection of information; search data sources; 
complete and review the collection of information; and transmit or 
otherwise disclose the information. An agency may not conduct or 
sponsor, and a person is not required to respond to a collection of 
information unless it displays a currently valid OMB control number. 
The OMB control numbers for EPA's regulations in 40 CFR are listed in 
40 CFR part 9.

C. Regulatory Flexibility Act

    The Regulatory Flexibility Act (RFA) generally requires an agency 
to prepare a regulatory flexibility analysis of any rule subject to 
notice and comment rulemaking requirements under the Administrative 
Procedure Act or any other statute unless the agency certifies that the 
rule will not have a significant economic impact on a substantial 
number of small entities. Small entities include small businesses, 
small organizations, and small governmental jurisdictions.
    For purposes of assessing the impacts of today's rule on small 
entities, small entity is defined as: (1) A small business defined by 
the Small Business Administration's (SBA) regulations at 13 CFR 
121.201; (2) a small governmental jurisdiction that is a government of 
a city, county, town, school district or special district with a 
population of less than 50,000; and (3) a small organization that is 
any not-for-profit enterprise which is independently owned and operated 
and is not dominant in its field.
    After considering the economic impacts of today's final rule on 
small entities, I certify that this action will not have a significant 
economic impact on a substantial number of small entities.
    This final rule will not impose any requirements on small entities. 
None of the corrections and clarifications creates additional 
regulatory requirements on affected entities compared to those that 
were promulgated in the final rule that was published in the Federal 
Register on October 17, 2006. The rule changes being made only correct 
printing errors, provide clarifications, and provides new flexibility 
for PM10 monitoring on a case-by-case basis.

D. Unfunded Mandates Reform Act

    Title II of the Unfunded Mandates Reform Act of 1995 (UMRA), Public 
Law 104-4, establishes requirements for Federal agencies to assess the 
effects of their regulatory actions on State, local, and tribal 
governments and the private sector. Under section 202 of the UMRA, EPA 
generally must prepare a written statement, including a cost-benefit 
analysis, for proposed and final rules with ``Federal mandates'' that 
may result in expenditures to State, local, and Tribal governments, in 
the aggregate, or to the private sector, of $100 million or more in any 
one year. Before promulgating an EPA rule for which a written statement 
is needed, section 205 of the UMRA generally requires EPA to identify 
and consider a reasonable number of regulatory alternatives and adopt 
the least costly, most cost-effective or least burdensome alternative 
that achieves the objectives of the rule. The provisions of section 205 
do not apply when they are inconsistent with applicable law. Moreover, 
section 205 allows EPA to adopt an alternative other than the least 
costly, most cost-effective or least burdensome alternative if the 
Administrator publishes with the final rule an explanation why that 
alternative was not adopted. Before EPA establishes any regulatory 
requirements that may significantly or uniquely affect small 
governments, including Tribal governments, it must have developed under 
section 203 of the UMRA a small government agency plan. The plan must 
provide for notifying potentially affected small governments, enabling 
officials of affected small governments to have meaningful and timely 
input in the development of EPA regulatory proposals with significant 
Federal intergovernmental mandates, and informing, educating, and 
advising small governments on compliance with the regulatory 
requirements.
    The EPA has determined that this final rule does not contain a 
Federal mandate that may result in expenditures of $100 million or more 
for State, local, and tribal governments, in the aggregate, or the 
private sector in any one year, because the changes being made are 
merely clarifications and corrections. Thus, today's rule is not 
subject to the requirements of sections 202 and 205 of the UMRA.
    The EPA has determined that this final rule contains no regulatory 
requirements that might significantly or uniquely affect small 
governments. None of the changes creates additional regulatory 
requirements on affected entities compared to those that were 
promulgated in the final rule that was published in the Federal 
Register on October 17, 2006. The rule changes being made only correct 
printing errors, provide clarifications, and provide some new 
flexibility for PM10 monitoring on a case-by-case basis. 
Therefore, this final rule is not subject to the requirements of 
section 203 of the UMRA.

E. Executive Order 13132: Federalism

    Executive Order 13132 (64 FR 43255, August 10, 1999), requires EPA 
to develop an accountable process to ensure ``meaningful and timely 
input by State and local officials in the development of regulatory 
policies that have federalism implications.'' ``Policies that have 
federalism implications'' is defined in the Executive Order to include 
regulations that have ``substantial direct effects on the States, on 
the relationship between the national government and the States, or on 
the distribution of power and responsibilities among the various levels 
of government.''
    This final rule does not have federalism implications because it 
will not have substantial direct effects on the States, on the 
relationship between the national government and the States, or on the 
distribution of power and responsibilities among the various levels of 
government, as specified in Executive Order 13132. This is because the 
changes being made only correct printing errors, provide 
clarifications, and provides some new flexibility for PM10 
monitoring on a case-by-case basis. Thus, Executive Order 13132 does 
not apply to this final rule.

F. Executive Order 13175: Consultation and Coordination With Indian 
Tribal Governments

    Executive Order 13175, entitled ``Consultation and Coordination 
with Indian Tribal Governments'' (65 FR 67249, November 9, 2000), 
requires EPA to develop an accountable process to ensure ``meaningful 
and timely input by tribal officials in the development of regulatory 
policies that have tribal implications.'' This final rule does not have 
tribal implications, as specified in Executive Order 13175. The EPA 
consulted with tribal officials early in the process of developing the 
October 17, 2006, rule to permit them to have meaningful and timely 
input into its development. Although tribal governments may elect to 
conduct ambient air monitoring, none of the changes in today's rule 
apply directly to tribal governments. Thus, Executive Order 13175 does 
not apply to this rule.

G. Executive Order 13045: Protection of Children From Environmental 
Health and Safety Risks

    Executive Order 13045 ``Protection of Children from Environmental 
Health Risks and Safety Risks'' (62 FR 19885,

[[Page 32202]]

April 23, 1997) applies to any rule that: (1) Is determined to be 
``economically significant'' as defined under EO 12866, and (2) 
concerns an environmental health or safety risk that EPA has reason to 
believe may have a disproportionate effect on children. If the 
regulatory action meets both criteria, the Agency must evaluate the 
environmental health or safety effects of the planned rule on children, 
and explain why the planned regulation is preferable to other 
potentially effective and reasonably feasible alternatives considered 
by the Agency.
    EPA interprets EO 13045 as applying only to those regulatory 
actions that concern health or safety risks, such that the analysis 
required under section 5-501 of the EO has the potential to influence 
the regulation. This final rule is not subject to EO 13045 because it 
does not establish an environmental standard intended to mitigate 
health or safety risks.

H. Executive Order 12898: Federal Actions To Address Environmental 
Justice in Minority Populations and Low-Income Populations

    Executive Order 12898 (59 FR 7629, February 16, 1994) establishes 
federal executive policy on environmental justice. Its main provision 
directs Federal agencies, to the greatest extent practicable and 
permitted by law, to make environmental justice part of their mission 
by identifying and addressing, as appropriate, disproportionately high 
and adverse human health or environmental effects of their programs, 
policies, and activities on minority populations and low-income 
populations in the United States.
    EPA has determined that this final rule will not have 
disproportionately high and adverse human health or environmental 
effects on minority or low-income populations because it does not 
affect the level of protection provided to human health or the 
environment. The rule merely amends the October 17, 2006, final 
monitoring rule (71 FR 61236) by correcting printing errors, providing 
clarifications, and providing some new flexibility for PM10 
monitoring on a case-by-case basis.

I. Executive Order 13211: Actions That Significantly Affect Energy 
Supply, Distribution, or Use

    This rule is not a ``significant energy action'' as defined in 
Executive Order 13211, ``Actions Concerning Regulations That 
Significantly Affect Energy Supply, Distribution or Use'' (66 FR 28355, 
May 22, 2001) because it is not likely to have a significant adverse 
effect on the supply, distribution, or use of energy. No significant 
change in the use of energy is expected because the total number of 
monitors for ambient air quality measurements will not increase above 
present levels. Further, we have concluded that this rule is not likely 
to have any adverse energy effects.

J. National Technology Transfer Advancement Act

    Section 12(d) of the National Technology Transfer and Advancement 
Act of 1995 (``NTTAA''), Public Law No. 104-113, 12(d) (15 U.S.C. 272 
note) directs EPA to use voluntary consensus standards in its 
regulatory activities unless to do so would be inconsistent with 
applicable law or otherwise impractical. Voluntary consensus standards 
are technical standards (e.g., materials specifications, test methods, 
sampling procedures, and business practices) that are developed or 
adopted by voluntary consensus standards bodies. The NTTAA directs EPA 
to provide Congress, through OMB, explanations when the Agency decides 
not to use available and applicable voluntary consensus standards.
    This action does not involve technical standards, other than to 
make corrections and clarifications. Therefore, EPA did not consider 
the use of any voluntary consensus standards.

K. Congressional Review Act

    The Congressional Review Act, 5 U.S.C. 801, et seq., as added by 
the Small Business Regulatory Enforcement Fairness Act of 1996, 
generally provides that before a rule may take effect, the agency 
promulgating the rule must submit a rule report, which includes a copy 
of the rule, to each House of Congress and to the Comptroller General 
of the United States. EPA will submit a report containing this rule and 
other required information to the U.S. Senate, the U.S. House of 
Representatives, and the Comptroller General of the United States prior 
to publication of the rule in the Federal Register. A major rule cannot 
take effect until 60 days after it is published in the Federal 
Register. This action is not ``major rule'' as defined by 5 U.S.C. 
804(2). This final rule will not have an annual effect on the economy 
of $100 million or more, will not result in a major increase in costs 
or prices for State or local agencies, and will not affect competition 
with foreign-based enterprises in domestic and export markets. The 
final amendments will be effective on September 10, 2007.

List of Subjects in 40 CFR Parts 53 and 58

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

    Dated: April 30, 2007.
Stephen L. Johnson,
Administrator.

0
For the reasons stated in the preamble, title 40, chapter I, parts 53 
and 58 of the Code of Federal Regulations are amended as follows:

PART 53--[AMENDED]

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

    Authority: Section 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 C--[Amended]

0
2. Section 53.35 is amended by:
0
a. Revising Equation 12 of paragraph (d)(4),
0
b. Revising Equation 13 of paragraph (e)(1),
0
c. Revising Equation 15 of paragraph (f)(1),
0
d. Revising Equation 17 of paragraph (g)(1), and
0
e. Revising Equation 21 of paragraph (h)(1) to read as follows:

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

* * * * *
    (d) * * *
    (4) * * *
    [GRAPHIC] [TIFF OMITTED] TR41AD07.000
    
Where:

Cj = The mean concentration measured by the candidate 
method for the measurement set;
Ci,j = The measurement of the candidate method sampler or 
analyzer i on test day j; and
m = The number of valid candidate method measurements in the 
measurement set (normally 3).

    (e) * * *
    (1) * * *

[[Page 32203]]

[GRAPHIC] [TIFF OMITTED] TR41AD07.001

* * * * *
    (f) * * *
    (1) * * *
    [GRAPHIC] [TIFF OMITTED] TR41AD07.002
    
* * * * *
    (g) * * *
    (1) * * *
    [GRAPHIC] [TIFF OMITTED] TR41AD07.003
    
* * * * *
    (h) * * *
    (1) * * *
    [GRAPHIC] [TIFF OMITTED] TR41AD07.004
    
* * * * *

0
3. Table C-1 to subpart C is revised to read as follows:

   Table C-1 to Subpart C of Part 53--Test Concentration Ranges, Number of Measurements Required, and Maximum
                                            Discrepancy Specification
----------------------------------------------------------------------------------------------------------------
                                                          Simultaneous measurements required
                                                     --------------------------------------------     Maximum
                                     Concentration            1-hr                  24-hr           discrepancy
            Pollutant              range, parts per  -------------------------------------------- specification,
                                        million                    Second                Second      parts per
                                                      First set     set     First set     set         million
----------------------------------------------------------------------------------------------------------------
Ozone...........................  Low 0.06 to 0.10..          5          6  .........  .........            0.02
                                  Med 0.15 to 0.25..          5          6  .........  .........             .03
                                  High 0.35 to 0.45.          4          6  .........  .........             .04
                                                     -----------------------------------------------------------
                                  Total.............         14         18  .........  .........  ..............
                                                     -----------------------------------------------------------
Carbon monoxide.................  Low 7 to 11.......          5          6  .........  .........             1.5
                                  Med 20 to 30......          5          6  .........  .........             2.0
                                  High 35 to 45.....          4          6  .........  .........             3.0
                                                     -----------------------------------------------------------
                                  Total.............         14         18  .........  .........  ..............
                                                     -----------------------------------------------------------
Sulfur dioxide..................  Low 0.02 to 0.05..  .........  .........          3          3            0.02
                                  Med 0.10 to 0.15..  .........  .........          2          3             .03
                                  High 0.30 to 0.50.          7          8          2          2             .04
                                                     -----------------------------------------------------------
                                  Total.............          7          8          7          8  ..............
                                                     -----------------------------------------------------------
Nitrogen dioxide................  Low 0.02 to 0.08..  .........  .........          3          3            0.02
                                  Med 0.10 to 0.20..  .........  .........          2          3             .03
                                  High 0.25 to 0.35.  .........  .........          2          2             .03
                                                     -----------------------------------------------------------
                                  Total.............  .........  .........          7          8  ..............
----------------------------------------------------------------------------------------------------------------

0
4. Table C-4 to subpart C is revised 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  15-300................  3-200............  3-200               3-200               3-200               3-200
 (Rj), [mu]g/m3.
Minimum number of test sites..  2.....................  1................  2                   4                   2                   4

[[Page 32204]]

Minimum number of candidate     3.....................  3................  3 \1\               3 \1\               3 \1\               3 \1\
 method samplers or analyzers
 per site.
Number of reference method      3.....................  3................  3 \1\               3 \1\               3 \1\               3 \1\
 samplers per site.
Minimum number of acceptable
 sample sets per site for PM10
 methods:
    Rj <  60 [mu]g/m3..........  3
    Rj > 60 [mu]g/m3..........  3
    Total.....................  10
Minimum number of acceptable
 sample sets per site for
 PM2.5 and PM10-2.5 candidate
 equivalent methods:
    Rj <  30 [mu]g/m3 for 24-hr  ......................  3
     or Rj <  20 [mu]g/m3 for
     48-hr samples.
    Rj > 30 [mu]g/m3 for 24-hr  ......................  3
     or Rj > 20 [mu]g/m3 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          5 [mu]g/m3 or 7%......  2 [mu]g/m3 or 5%.  10% 2               10% 2               10% 2               10% 2
 reference method
 measurements, PRj or 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             1  0.10...  1      1       1       1       1 
 relationship..                                          0.05.              0.10                0.10                0.10                0.12
Intercept of regression         0  5......  0  1.  Between: 13.55 -    Between: 15.05 -    Between: 62.05 -    Between: 70.50 -
 relationship, [mu]g/m3.                                                    (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
                                                                            -1.5; and 16.56 -   -2.0; and 15.05 -   -3.5; and 78.95 -   than -7.0; and
                                                                            (15.05 x slope),    (13.20 x slope),    (70.5 x slope),     70.50 - (61.16 x
                                                                            but not more than   but not more than   but not more than   slope), but not
                                                                            +1.5                +2.0                +3.5                more than +7.0
                               -------------------------------------------------------------------------------------------------------------------------
Correlation of reference        >= 0.97...............  >= 0.97..........  >= 0.93--for CCV <= 0.4; >= 0.85 + 0.2 x CCV--for 0.4 <= CCV <= 0.5; >= 0.95--
 method and candidate method                                                                               for CCV >= 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.

0
5. Figures C-1 through C-4 to subpart C are revised to read as follows:

Figure C-1 to Subpart C of Part 53--Suggested Format for Reporting 
Test Results for Methods for SO 2, CO, O 3, NO 2

Candidate Method-------------------------------------------------------

Reference Method-------------------------------------------------------

Applicant--------------------------------------------------------------

[ballot] First Set [ballot] Second Set [ballot] Type [ballot] 1 Hour 
[ballot] 24 Hour

[[Page 32205]]

--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                Concentration, ppm
      Concentration range                      Date            Time      --------------------------------   Difference       Table C-1     Pass or fail
                                                                             Candidate       Reference                         spec.
--------------------------------------------------------------------------------------------------------------------------------------------------------
              Low                1
                                ------------------------------------------------------------------------------------------------------------------------
-------- ppm                     2
                                ------------------------------------------------------------------------------------------------------------------------
to -------- ppm                  3
                                ------------------------------------------------------------------------------------------------------------------------
                                 4
                                ------------------------------------------------------------------------------------------------------------------------
                                 5
                                ------------------------------------------------------------------------------------------------------------------------
                                 6
--------------------------------------------------------------------------------------------------------------------------------------------------------
             Medium              1
                                ------------------------------------------------------------------------------------------------------------------------
-------- ppm                     2
                                ------------------------------------------------------------------------------------------------------------------------
to -------- ppm                  3
                                ------------------------------------------------------------------------------------------------------------------------
                                 4
                                ------------------------------------------------------------------------------------------------------------------------
                                 5
                                ------------------------------------------------------------------------------------------------------------------------
                                 6
--------------------------------------------------------------------------------------------------------------------------------------------------------
              High               1
                                ------------------------------------------------------------------------------------------------------------------------
-------- ppm                     2
                                ------------------------------------------------------------------------------------------------------------------------
to -------- ppm                  3
                                ------------------------------------------------------------------------------------------------------------------------
                                 4
                                ------------------------------------------------------------------------------------------------------------------------
                                 5
                                ------------------------------------------------------------------------------------------------------------------------
                                 6
                                ------------------------------------------------------------------------------------------------------------------------
                                 7
                                ------------------------------------------------------------------------------------------------------------------------
                                 8
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                 .......  ..............  ..............  ..............  ..............  ..............           Total
                                                                                                                               Failures:
--------------------------------------------------------------------------------------------------------------------------------------------------------

[[Page 32206]]

[GRAPHIC] [TIFF OMITTED] TR41AD07.009

[[Page 32207]]

[GRAPHIC] [TIFF OMITTED] TR41AD07.010

[[Page 32208]]

[GRAPHIC] [TIFF OMITTED] TR41AD07.011

Subpart E--[Amended]

0
6. Section 53.58 is amended by revising Equation 26 of paragraph 
(g)(2)(i) to read as follows:

Sec.  53.58  Operational field precision and blank test.

* * * * *
    (g) * * *
    (2)(i) * * *
    [GRAPHIC] [TIFF OMITTED] TR41AD07.005
    
* * * * *
0
7. Table E-1 to subpart E is revised to read as follows:

  Table E-1 to Subpart E of Part 53.--Summary of Test Requirements for Reference and Class I Equivalent Methods
                                             for PM2.5 and PM10	2.5
----------------------------------------------------------------------------------------------------------------
                                                          Performance                          Part 50, appendix
       Subpart E procedure         Performance test      specification      Test conditions      L  reference
----------------------------------------------------------------------------------------------------------------
Sec.   53.52 Sample leak check    Sampler leak check  External leakage:   Controlled leak     Sec. 7.4.6.
 test.                             facility.           80 mL/min, max.     flow rate of 80
                                                      Internal leakage:    mL/ min.
                                                       80 mL/min, max.
----------------------------------------------------------------------------------------------------------------
Sec.   53.53 Base flow rate test  Sample flow rate..  1. 16.67 < plus-     (a) 6-hour normal   Sec. 7.4.1.
                                  1. Mean...........   minus> 5%, L/ min.  operational test   Sec. 7.4.2.
                                  2. Regulation.....  2. 2%, max........   plus flow rate     Sec. 7.4.3.
                                  3. Meas accuracy..  3. 2%, max........   cut-off test.      Sec. 7.4.4.
                                  4. CV accuracy....  4. 0.3% max.......  (b) Normal          Sec. 7.4.5.
                                  5. Cut-off........  5. Flow rate cut-    conditions.
                                                       off if flow rate   (c) Additional 55
                                                       deviates more       mm Hg pressure
                                                       than 10% from       drop to simulate
                                                       design flow rate    loaded filter.
                                                       for >60  30 seconds.  restriction used
                                                                           for cut-off test.

[[Page 32209]]

Sec.   53.54 Power interruption   Sample flow rate..  1. 16.67 < plus-     (a) 6-hour normal   Sec. 7.4.1.
 test.                            1. Mean...........   minus> 5%, L/ min.  operational test.  Sec. 7.4.2.
                                  2. Regulation.....  2. 2%, max........  (b) Nominal         Sec. 7.4.3.
                                  3. Meas. accuracy.  3. 2%, max........   conditions.        Sec. 7.4.5.
                                  4. CV accuracy....  4. 0.3% max.......  (c) Additional 55   Sec. 7.4.12.
                                  5. Occurrence time  5.  2    mm Hg pressure     Sec. 7.4.13.
                                   of power            min if >60          drop to simulate   Sec. 7.4.15.4.
                                   interruptions.      seconds..           loaded filter.     Sec. 7.4.15.5.
                                  6. Elapsed sample   6.  20  (d) 6 power
                                   time.               seconds.            interruptions of
                                  7. Sample volume..  7.       various durations.
                                                       2%, max.
----------------------------------------------------------------------------------------------------------------
Sec.   53.55 Temperature and      Sample flow rate..  1. 16.67 < plus-     (a) 6-hour normal   Sec. 7.4.1.
 line voltage test.               1. Mean...........   minus> 5%, L/ min.  operational test.  Sec. 7.4.2.
                                  2. Regulation.....  2. 2%, max........  (b) Normal          Sec. 7.4.3.
                                  3. Meas. accuracy.  3. 2%, max........   conditions.        Sec. 7.4.5.
                                  4. CV accuracy....  4. 0.3% max.......  (c) Additional 55   Sec. 7.4.8.
                                  5. Temperature      5. 2 [deg]C.......   mm Hg pressure     Sec. 7.4.15.1.
                                   meas. accuracy.                         drop to simulate
                                  6. Proper                                loaded filter.
                                   operation..                            (d) Ambient
                                                                           temperature at -
                                                                           20 and +40 [deg]C.
                                                                          (e) Line voltage:
                                                                           105 Vac to 125
                                                                           Vac.
----------------------------------------------------------------------------------------------------------------
Sec.   53.56 Barometric pressure  Sample flow rate..  1. 16.67 < plus-     (a) 6-hour normal   Sec. 7.4.1.
 effect test.                     1. Mean...........   minus> 5%, L/ min.  operational test.  Sec. 7.4.2.
                                  2. Regulation.....  2. 2%, max........  (b) Normal          Sec. 7.4.3.
                                  3. Meas. accuracy.  3. 2%, max........   conditions.        Sec. 7.4.5.
                                  4. CV accuracy....  4. 0.3% max.......  (c) Additional 55   Sec. 7.4.9.
                                  5. Pressure meas.   5. 10 mm Hg.......   mm Hg pressure
                                   accuracy.                               drop to simulate
                                  6. Proper                                loaded filter.
                                   operation..                            (d) Barometric
                                                                           pressure at 600
                                                                           and 800 mm Hg.
----------------------------------------------------------------------------------------------------------------
Sec.   53.57 Filter temperature   1. Filter temp.     1. 2 [deg]C.......  (a) 4-hour          Sec. 7.4.8.
 control test.                     meas. accuracy.    2. 2 [deg]C.......   simulated solar    Sec. 7.4.10.
                                  2. Ambient temp.    3. Not more than 5   radiation,         Sec. 7.4.11.
                                   meas. accuracy.     [deg]C above        sampling.
                                  3. Filter temp.      ambient temp. for  (b) 4-hour
                                   control accuracy,   more than 30 min.   simulated solar
                                   sampling and non-                       radiation, non-
                                   sampling.                               sampling.
                                                                          (c) Solar flux of
                                                                           1000 
                                                                           50 W/m 2.
----------------------------------------------------------------------------------------------------------------
Sec.   53.58 Field precision      1. Measurement      1. Pj <  2 [mu]g/m3  (a) 3 collocated    Sec. 5.1.
 test.                             precision.          or RPj <  5%.        samplers at 1      Sec. 7.3.5.
                                  2. Storage          2. 50 [mu]g max.     site for at least  Sec. 8.
                                   deposition test     average weight      10 days.           Sec. 9.
                                   for sequential      gain/blank filter. (b) PM2.5 conc. >   Sec. 10.
                                   samplers.                               3 [mu]g/m3.
                                                                          (c) 24- or 48-hour
                                                                           samples.
                                                                          (d) 5- or 10-day
                                                                           storage period
                                                                           for inactive
                                                                           stored filters.
----------------------------------------------------------------------------------------------------------------
              The Following Requirement Is Applicable to Class I Candidate Equivalent Methods Only
----------------------------------------------------------------------------------------------------------------
Sec.   53.59 Aerosol transport    Aerosol transport.  97%, min. for all   Determine aerosol
 test.                                                 channels..          transport through
                                                                           any new or
                                                                           modified
                                                                           components with
                                                                           respect to the
                                                                           reference method
                                                                           sampler before
                                                                           the filter for
                                                                           each channel.
----------------------------------------------------------------------------------------------------------------

Subpart F--[Amended]

0
8. Table F-1 to subpart F is revised to read as follows:

[[Page 32210]]

Table F-1 to Subpart F of Part 53.--Performance Specifications for PM2.5
                      Class II Equivalent Samplers
------------------------------------------------------------------------
      Performance test           Specifications      Acceptance criteria
------------------------------------------------------------------------
Sec.   53.62 Full Wind        Solid VOAG produced   Dp50 = 2.5 [mu]m
 Tunnel Evaluation.            aerosol at 2 km/hr     0.2
                               and 24 km/hr.         [mu]m Numerical
                                                     Analysis Results:
                                                     95% < = Rc < = 105%.
Sec.   53.63 Wind Tunnel      Liquid VOAG produced  Relative Aspiration:
 Inlet Aspiration Test.        aerosol at 2 km/hr    95% < = A < = 105%.
                               and 24 km/hr.
Sec.   53.64 Static           Evaluation of the     Dp50 = 2.5 [mu]m
 Fractionator Test.            fractionator under     0.2
                               static conditions.    [mu]m Numerical
                                                     Analysis Results:
                                                     95% < = Rc < = 105%.
Sec.   53.65 Loading Test...  Loading of the clean  Acceptance criteria
                               candidate under       as specified in the
                               laboratory            post-loading
                               conditions.           evaluation test
                                                     (Sec.   53.62, Sec.
                                                       53.63, or Sec.
                                                     53.64).
Sec.   53.66 Volatility Test  Polydisperse liquid   Regression
                               aerosol produced by   Parameters Slope =
                               air nebulization of   1  0.1,
                               A.C.S. reagent        Intercept = 0 < plus-
                               grade glycerol,       minus> 0.15 mg, r
                               99.5% minimum         >= 0.97.
                               purity.
------------------------------------------------------------------------

PART 58--[AMENDED]

0
9. The authority citation for part 58 continues to read as follows:

    Authority: 42 U.S.C. 7403, 7410, 7601(a), 7611, and 7619.

Subpart B--[Amended]

0
10. Section 58.10 is amended by revising the second sentence in 
paragraph (a)(2) to read as follow:

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

    (a)(1) * * *
    (2) * * * If the State or local agency has already provided a 
public comment opportunity on its plan and has made no changes 
subsequent to that comment opportunity, and has submitted the received 
comments together with the plan, the Regional Administrator is not 
required to provide a separate opportunity for comment.
* * * * *

0
11. Section 58.12 is amended by revising paragraph (d)(1), paragraph 
(d)(3), and the first sentence of paragraph (e) 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.
    (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. 
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. Required SLAMS stations whose measurements determine the design 
value for their area and that are within plus or minus 10 percent of 
the NAAQS; and all required sites where one or more 24-hour values have 
exceeded the 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. A continuously operating FEM or ARM PM2.5 monitor 
satisfies this requirement.
    (iii) Required SLAMS stations whose measurements determine the 
design value for their area and that are within plus or minus 5 percent 
of the daily PM2.5 NAAQS must have an FRM or FEM operate on 
a daily schedule. A continuously operating FEM or ARM PM2.5 
monitor satisfies this requirement.
* * * * *
    (3) Manual PM2.5 speciation samplers at STN stations 
must operate on at least a 1-in-3 day sampling frequency.
    (e) For PM10 samplers, a 24-hour sample must be taken 
from midnight to midnight (local standard time) to ensure national 
consistency. * * *

Sec.  58.12  [Amended]

0
12. Figure 1 of paragraph (e) of Sec.  58.12 is revised to read as 
follows:

Subpart C--[Amended]

0
13. Section 58.20(c) is revised to read as follows:

Sec.  58.20  Special purpose monitors (SPM).

* * * * *

[[Page 32211]]

[GRAPHIC] [TIFF OMITTED] TR41AD07.012

    (c) All data from an SPM using an FRM, FEM, or ARM which has 
operated for more than 24 months is eligible for comparison to the 
relevant NAAQS, subject to the conditions of Sec.  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 in practice.
* * * * *

Appendix A to Part 58--[Amended]

0
14. Appendix A is amended by:
0
a. Revising the third (last) sentence of section 2.4;
0
b. Revising Equation 7 of section 4.1.4;
0
c. Revising the definition of the symbol ``n'' for Equation 11 of 
section 4.2.1,
0
d. Revising the last sentence in section 4.2.2.2, and
0
e. Revising the definition of the symbol ``nj'' for Equation 
12 of section 4.3.2.1 to read as follows:

2. General Monitoring Requirements

* * * * *
    2.4 * * * For clarification and to participate, monitoring 
organizations should contact either the appropriate EPA Regional 
Quality Assurance (QA) Coordinator at the appropriate EPA Regional 
Office location, or the NPAP Coordinator at the Air Quality 
Assessment Division, Office of Air Quality Planning and Standards, 
U.S. Environmental Protection Agency in Research Triangle Park, 
North Carolina.
* * * * *

4. Calculations for Data Quality Assessments

* * * * *
    4.1.4 * * *
    [GRAPHIC] [TIFF OMITTED] TR41AD07.006
    
* * * * *
    4.2.1 * * *
    [GRAPHIC] [TIFF OMITTED] TR41AD07.007
    

 where, n is the number of valid data pairs being aggregated, and 
X2 0.1, n-1 is the 10th percentile of a chi-
squared distribution with n-1 degrees of freedom. The factor of 2 in 
the denominator adjusts for the fact that each di is 
calculated from two values with error.

    4.2.2 * * * The absolute volume bias upper bound is then 
calculated using equation 3 of this appendix, where n is the number 
of flow rate audits being aggregated; t0.95, n-1 is the 
95th quantile of a t-distribution with n-1 degrees of freedom, the 
quantity AB is the mean of the absolute values of the 
di's and is calculated using equation 4 of this appendix, 
and the quantity AS in equation 3 of this appendix is the standard 
deviation of the absolute values of the di's and is 
calculated using equation 5 of this appendix.
    4.3.2.1 * * *
    [GRAPHIC] [TIFF OMITTED] TR41AD07.008
    

    where, nj is the number of pairs and d1, d2, * * *, 
dnj are the biases for each of the pairs to be averaged.
* * * * *

Appendix D to Part 58--[Amended]

0
15. Appendix D is amended by:
0
a. Revising section 4.6(a);
0
b. Revising the title of Table D-4 and Footnote 1 to Table D-4; and
0
c. Revising section 4.7.2 to read as follows:

4. Pollutant-Specific Design Criteria for SLAMS Sites

* * * * *
    4.6 Particulate Matter (PM10) Design Criteria.
    (a) Table D-4 indicates the approximate number of permanent 
stations required in MSAs to characterize national and regional 
PM10 air quality trends and geographical patterns. The 
number of PM10 stations in areas where MSA populations 
exceed 1,000,000 must be in the range from 2 to 10 stations, while 
in low population urban areas, no more than two stations are 
required. A range of monitoring stations is specified in Table D-4 
because sources of pollutants and local control efforts can vary 
from one part of the country to another and therefore, some 
flexibility is allowed in selecting the actual number of stations in 
any one locale. Modifications from these PM10 monitoring 
requirements must be approved by the Regional Administrator.

Table D-4 of Appendix D to Part 58. PM10 Minimum Monitoring 
Requirements (Approximate Number of Stations Per MSA) \1\

* * * * *
---------------------------------------------------------------------------

    \1\ Selection of urban areas and actual numbers of stations per 
area will be jointly determined by EPA and the State agency.
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    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 of this 
appendix. At least one required continuous analyzer in each MSA must 
be collocated with one of the required FRM/FEM/ARM monitors, unless 
at least one of the required FRM/FEM/ARM monitors is itself a 
continuous FEM or ARM monitor in

[[Page 32212]]

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.
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[FR Doc. 07-2201 Filed 6-11-07; 8:45 am]

BILLING CODE 6560-50-P