[Federal Register Volume 61, Number 241 (Friday, December 13, 1996)]
[Proposed Rules]
[Pages 65780-65872]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 96-31437]



[[Page 65779]]

_______________________________________________________________________

Part VI





Environmental Protection Agency





_______________________________________________________________________



40 CFR Parts 53 and 58



Proposed Requirements for Designation of Reference and Equivalent 
Methods for PM2.5 and Ambient Air Quality Surveillance for 
Particulate Matter; Proposed Rule

  Federal Register / Vol. 61, No. 241 / Friday, December 13, 1996 / 
Proposed Rules  

[[Page 65780]]



ENVIRONMENTAL PROTECTION AGENCY

40 CFR Parts 53 and 58

RIN 2060-AH09
[AD-FRL-5659-2]


Proposed Requirements for Designation of Reference and Equivalent 
Methods for PM2.5 and Ambient Air Quality Surveillance for 
Particulate Matter

AGENCY: Environmental Protection Agency (EPA).

ACTION: Proposed rule.

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SUMMARY: The EPA proposes to revise 40 CFR part 58 to establish ambient 
air quality monitoring requirements for PM2.5 (particles with an 
aerodynamic diameter less than or equal to a nominal 2.5 micrometers) 
as measured by a new reference method being proposed in Appendix L to 
40 CFR part 50 or by an equivalent method designated in accordance with 
requirements being proposed in 40 CFR part 53. In addition, this 
document also proposes certain revisions to existing ambient air 
quality monitoring requirements for PM10 (particles with an 
aerodynamic diameter less than or equal to a nominal 10 micrometers). 
The changes proposed in this document address among other things, 
network design and siting, quality assurance and quality control, and 
monitoring methodology. The document also indicates EPA's intent to 
explore opportunities to coordinate and integrate the existing 
visibility monitoring requirements with the ambient air quality 
monitoring requirements for particulate matter being proposed today to 
accommodate a better regional haze program and to reduce burdens and 
achieve multiple monitoring objectives.

DATES: Comments must be submitted on or before February 18, 1997.

ADDRESSES: Comments should be submitted (in duplicate, if possible) to: 
Air Docket (LE-131), U.S. Environmental Protection Agency, Attn. Docket 
No. A-96-51, 401 M Street, SW, Washington, DC 20460. The docket may be 
inspected between 8:00 a.m. and 5:30 p.m. on weekdays. A reasonable fee 
may be charged for copying.
    Public hearing: The EPA will announce in a separate Federal 
Register document the date, time, and address of the public hearing on 
this proposed decision.
FOR FURTHER INFORMATION CONTACT: Mr. Neil Frank (MD-14), Monitoring and 
Quality Assurance Group, Emissions, Monitoring, and Analysis Division, 
U.S. Environmental Protection Agency, Research Triangle Park, North 
Carolina 27711, telephone (919) 541-5560.

SUPPLEMENTARY INFORMATION:

Table of Contents

I. Authority
II. Introduction
III. Discussion of Proposed Revisions to Part 53
    A. Designation of Reference and Equivalent Methods
    B. Quality Assurance
IV. Discussion of Proposed Revisions to Part 58
    A. Section 58.1  Definitions
    B. Section 58.13  Operating schedule
    C. Section 58.14  Special purpose monitors
    D. Section 58.15  PM2.5 NAAQS eligible monitors
    E. Section 58.20  Air quality surveillance: plan content
    F. Section 58.23  Monitoring network completion
    G. Section 58.25  System modification
    H. Section 58.26  Annual SLAMS summary report
    I. Section 58.30  NAMS network establishment
    J. Section 58.31  NAMS network description
    K. Section 58.34  NAMS network completion
    L. Section 58.35  NAMS data submittal
    M. Appendix A--Quality Assurance Requirements for State and 
Local Air Monitoring Stations (SLAMS)
    N. Appendix B--Quality Assurance Requirements for Prevention of 
Significant Deterioration (PSD) Air Monitoring
    O. Appendix C--Ambient Air Quality Monitoring Methodology
    P. Appendix D--Network Design for State and Local Air Monitoring 
Stations (SLAMS), National Air Monitoring Stations (NAMS), and 
Photochemical Assessment Monitoring Stations (PAMS)
    Q. Appendix E--Probe and Monitoring Path Siting Criteria for 
Ambient Air Quality Monitoring
    R. Cost Estimates for New PM Networks
    S. Reference
V. Administrative Requirements
    A. Regulatory Impact Analysis
    B. Reporting and Record keeping Requirements
    C. Impact on Small Entities
    D. Unfunded Mandates Reform Act of 1995

I. Authority

    Sections 110, 301(a), and 319 of the Clean Air Act as amended 42 
U.S.C. 7410, 7601(a), 7619.

II. Introduction

A. Proposed Revision to the Particulate Matter NAAQS

    Elsewhere in today's Federal Register, EPA announced proposed 
revisions to the national ambient air quality standards for particulate 
matter. In that notice, EPA proposes to amend the current suite of 
PM10 standards by adding new PM2.5 standards and by revising 
the form of the current 24-hour PM10 standard. Specifically, the 
EPA proposes to add two new primary PM2.5 standards set at 15 
g/m3, annual mean, and 50 g/m3, 24-hour 
average. The proposed new annual PM2.5 standard would be met when 
the 3-year average of the annual arithmetic mean PM2.5 
concentrations, spatially averaged across an area, is less than or 
equal to 15 g/m3. The proposed new 24-hour PM2.5 
standard would be met when the 3-year average of the 98th percentile of 
24-hour PM2.5 concentrations at each monitor within an area is 
less than or equal to 50.
    The EPA also proposes to retain the current annual PM10 
standard at the level of 50 g/m3, which would be met when 
the 3-year average of the annual arithmetic PM10 concentrations at 
each monitor within an area is less than or equal to 50 g/
m3. Further, EPA proposes to retain the current 24-hour PM10 
standard at the level of 150 g/m3, but to revise the form 
such that the standard would be met when the 3-year average of the 98th 
percentile of the monitored concentrations at the highest monitor in an 
area is less than or equal to 150 g/m3.
    In the part 50 notice, EPA also proposed to revise the current 
secondary standards by making them identical to the suite of proposed 
primary standards. The suite of PM2.5 and PM10 standards, in 
conjunction with the establishment of a regional haze program under 
section 169A of the Clean Air Act (Act), are intended to protect 
against PM-related welfare effects including soiling and materials 
damage and visibility impairment.
    As discussed in the part 50 notice, the proposed new PM2.5 
standards are intended to protect against exposures to fine particulate 
pollution, while the new PM10 standards are intended to protect 
against coarse fraction particles as measured by PM10.
    For PM2.5, the annual standard is intended to protect against 
both long- and short-term exposures to fine particle pollution. Under 
this approach, the PM2.5 24-hour standard would serve as a ``back 
stop'' to provide additional protection against days with high 
PM2.5 concentrations, localized ``hot spots,'' and risks arising 
from seasonal emissions that would not be well controlled by a national 
annual standard.
    In specifying that the calculation of the annual arithmetic mean 
for an area (for purposes of comparison to level of PM2.5 annual 
standard) should be

[[Page 65781]]

accomplished by averaging the annual arithmetic means derived from 
multiple, population-oriented monitoring sites, EPA took into account 
several factors. As discussed in the part 50 notice, many of the 
community-based epidemiologic studies examined in this review used 
spatial averages, when multiple monitoring sites were available, to 
characterize area-wide PM exposure levels and associated public health 
risk. Even in those studies that used only one monitoring location, the 
selected site was chosen to represent community-wide exposures, not the 
highest value likely to be experienced within the community. Because 
the annual PM2.5 standard would be intended to reduce aggregate 
population risk from both long- and short-term exposures by lowering 
the broad distribution of PM concentrations across the community, an 
annual standard based on spatially averaged concentrations from several 
population-oriented monitoring sites would better reflect areawide PM 
exposure levels and associated health risks than would a standard based 
on concentrations from a single monitor with the highest measured 
values in the area. The spatial average approach is not appropriate for 
PM10 because the spatial distribution of coarse particles is 
different and tends to be more localized in its behavior.
    Finally, under the policy approach presented in the part 50 notice, 
the 24-hour PM2.5 standard would be intended to supplement a 
spatially-averaged annual PM2.5 standard by providing protection 
against peak 24-hour concentrations arising from situations that would 
not be well-controlled by an annual standard. Accordingly, the 24-hour 
PM2.5 standard would be based on the single population-oriented 
monitoring site within a monitoring planning area with the highest 
measured values.
    In EPA's judgment, an annual PM2.5 standard expressed as a 
spatial average, established in conjunction with a 24-hour standard 
based on the monitoring site with the highest measured values, would 
provide the most appropriate target for reducing area-wide population 
exposure to fine particle pollution and would be most consistent with 
the underlying epidemiologic data base. On the other hand, EPA is 
mindful that adoption of spatial averaging for a PM2.5 standard 
would add a degree of complexity to the monitoring siting requirements 
and to the specification of those areas across which spatial averaging 
should be permitted. This approach may also require larger monitoring 
networks in some areas. By proposing a spatial averaging approach, the 
part 50 notice recognizes that some monitoring planning areas may have 
to be subdivided into smaller subareas to reflect gradients in particle 
levels (e.g., upwind suburban sites, central city sites, downwind 
sites) as well as topographical barriers or other factors that may 
result in a monitoring planning area having several distinct air 
quality regimes.
    Recognizing the complexities that spatial averaging may introduce 
into risk management programs and that unforeseen issues may arise from 
public comment on the requirements presented in this notice, the part 
50 notice also requests comment on the alternative of basing the 
PM2.5 annual standard on the population-oriented monitoring site 
within the monitoring planning area with the highest 3-year average 
annual mean. The part 50 notice indicates, based on comments received, 
that EPA may choose either of these two approaches for specifying the 
form of the annual PM2.5 standard at the time of promulgation of 
any revisions to the PM standards.
    In the part 50 notice, EPA also solicits comments on alternative 
levels of both annual and 24-hour PM2.5 primary standards and on 
revoking the current 24-hour primary PM10 standard.

B. Air Quality Monitoring Requirements

    Section 110(a)(2)(C) of the Act requires ambient air quality 
monitoring for purposes of the State implementation plans (SIP's) and 
for reporting data quality to EPA. Uniform criteria to be followed when 
measuring air quality and provisions for daily air pollution index 
reporting are required by section 319 of the Act. To satisfy these 
requirements, on May 10, 1979 (44 FR 27558), EPA established 40 CFR 
part 58 which provided detailed requirements for air quality 
monitoring, data reporting, and surveillance for all of the pollutants 
for which national ambient air quality standards have been established 
(criteria pollutants). Provisions were promulgated subsequently for 
particulate matter (PM10) on July 1, 1987 (52 FR 24740).
    The intent of the air quality surveillance requirement being 
proposed today is to establish a revised particulate matter monitoring 
network that would produce air quality data for the purpose of 
comparison to the proposed primary and secondary PM NAAQS and to 
facilitate implementation of a possible new regional haze program. In 
developing a new particulate matter monitoring network and associated 
requirements, consideration has been given to the indicators, forms, 
and levels of the proposed primary and secondary PM NAAQS. As a result, 
nationwide monitoring would be performed for two indicators of PM: 
PM2.5 and PM10. To be reflective of the basis for and the 
specification of the forms of the proposed new annual and 24-hour 
primary and secondary PM2.5 NAAQS, new monitoring network design 
and siting requirements are being proposed. For purposes of comparison 
to the proposed PM2.5 annual standard, such sites would be 
population-oriented and be representative of community-wide exposure 
levels. The siting criteria for monitors to be used for comparison to 
the proposed 24-hour PM2.5 standard would also be population-
oriented but reflective of the highest measured values within the 
community. To ensure PM data of the highest possible quality, new 
requirements for quality assurance and designation of new PM2.5 
reference or equivalent samplers are also described.
    With respect to NAAQS comparisons and visibility protection in more 
rural areas, the new network design and siting requirements would 
encourage the placement of PM2.5 monitors outside population 
centers with two purposes in mind: (1) To provide air quality data 
necessary to facilitate implementation of the proposed NAAQS, and (2) 
augmentation of the existing visibility fine particle monitoring 
network. The coordination of these two monitoring objectives would 
facilitate implementation of a regional haze program and lead to an 
integrated monitoring program for fine particles.
    The network design and siting requirements for the annual and 24-
hour PM10 NAAQS would continue to emphasize identification of 
locations at maximum concentrations. The PM10 network itself, 
however, would be revised because the proposed PM2.5 standards 
would likely be the controlling standards in most situations.
    The new network for PM10 would be derived from the existing 
network of State and Local Air Monitoring Stations (SLAMS), National 
Air Monitoring Stations (NAMS), and other monitors generically 
classified as Special Purpose Monitors (SPM's) which include industrial 
and special study monitors. Population-oriented NAMS will generally be 
maintained, other key sampling locations in existing nonattainment 
areas, and in areas whose concentrations are near the levels of the 
proposed PM10 NAAQS will be continued. Currently approved 
reference or equivalent PM10 samplers could continue to be 
utilized. The revised network would ensure that analysis of national 
trends in PM10 can

[[Page 65782]]

be continued, that air surveillance in areas with established PM 
emission control programs can be maintained, and that the PM10 
NAAQS will not be jeopardized by additional growth in PM10 
emissions. PM10 sites should be collocated with new PM2.5 
sites at key population-oriented monitoring stations so that better 
definition of fine and coarse contributions to PM10 can be 
determined to provide a better understanding of exposure, emission 
controls, and atmospheric processes. PM10 sites not needed for 
trends or for monitoring in areas with relatively high PM10 
concentrations would likely be discontinued in a longer-term PM10 
network. The sampling frequency at all PM10 sites would be reduced 
to a minimum of once in 6 days, which would be sufficient to make 
comparisons with proposed PM10 standards. The combination of fewer 
PM10 sites and the reduction in required sampling frequency would 
save significant resources that could be redirected to PM2.5 
monitoring.
    The new network for PM2.5 would consist of a ``core'' network 
of population-oriented SLAMS monitors, ``core'' regional background and 
regional transport SLAMS, a NAMS subset for long-term monitoring, other 
SLAMS monitors, and supplementary network of SPM's. The core 
population-oriented sites would be reflective of community-wide 
exposure and would be required in all of the largest metropolitan areas 
and must sample everyday. Frequent measurements are important to 
understand episodic behavior of PM2.5, and to establish effective 
emission control strategies to assure protection of the NAAQS. Many of 
the new PM2.5 sites are expected to be located at existing 
PM10 sites, and would be collocated with some PAMS sites.
    Consistency with the proposed new PM2.5 NAAQS necessitates the 
adoption of new concepts for identification and establishment of 
monitoring stations for the PM2.5 ambient air monitoring network 
as well as use of the data in relation to the proposed PM2.5 
NAAQS. These concepts include: (1) The addition of specially coded 
sites whose data would be used to compare to the levels of the annual 
and 24-hour PM2.5 NAAQS, and (2) the inclusion of monitoring 
planning areas and spatial averaging zones (SAZ) to correspond to the 
population-oriented, spatial averaging approach. These concepts and 
associated requirements are discussed in sections 58.15 and sections 
2.8.1-2.8.3 of Appendix D below.
    Although the major emphasis of the new PM networks is compliance 
monitoring in support of the NAAQS, the network is also intended to 
assist in reporting of data to the general public, especially during 
air pollution episodes and to assist in the SIP planning process. To 
these ends, additional monitoring and analysis requirements are 
proposed concerning the location of nephelometers (or other continuous 
particulate matter measuring devices) at some core monitoring sites and 
the archiving of filters for possible subsequent analysis for subsets 
of the PM2.5 SLAMS sites. Moreover, collection of meteorological 
data at core SLAMS sites (including background and regional transport 
sites) are suggested. The additional requirements should help to 
further characterize the composition and trends in PM2.5 and 
better understand the sources and processes leading to elevated 
PM2.5 concentrations. Because these proposed revisions do not 
specifically require the chemical analysis of collected PM2.5 or 
PM10 filters, the Administrator would welcome comments on this 
issue. In particular, comments are solicited on the need for 
alternative PM2.5 monitoring methodologies and additional 
monitoring requirements which might accompany the part 51 
implementation rules to identify the causes of detected PM2.5 
NAAQS violations and to assist in the development of PM2.5 
emission control strategies.
    While the proposed siting criteria and network designs are 
appropriate for both the proposed revisions to the primary and 
secondary NAAQS as a whole, additional consideration must be given to 
air quality surveillance in more rural/remote areas to characterize 
fine particle levels in order to protect against broader regional scale 
visibility impairment. To achieve the appropriate level of air quality 
surveillance in such areas, EPA believes it is important to coordinate 
and integrate the background and transport monitoring sites specified 
in this notice with the existing Interagency Monitoring of Protected 
Visual Environments (IMPROVE) monitors that are in place in a number of 
locations around the country to characterize fine particle levels and 
visibility in mandatory Federal Class I areas (e.g., certain national 
parks and wilderness areas). The need for coordination and integration 
of visibility-oriented monitoring sites will increase when EPA proposes 
rules under section 169A of the Act to supplement the secondary NAAQS 
in addressing regional haze. More detailed guidance on monitoring and 
assessment requirements will be provided when those rules are proposed. 
This will include details on topics such as monitor placement, 
monitoring methodology, duration of sampling and frequency of sampling. 
It is anticipated, however, that the existing IMPROVE network, together 
with sites established under this proposal, would be an integral part 
of the network for determining reasonable progress under a regional 
haze program.
    In the meantime, EPA recommends that States, in conjunction with 
EPA and Federal land managers, explore opportunities for expanding and 
managing PM2.5 and visibility monitoring networks in most 
efficient and effective ways to meet the collective goals of these 
programs. To facilitate this, EPA has proposed changes in Appendix C 
below, to allow use of existing or new IMPROVE monitoring sites to meet 
the requirements for a transport and/or background site for the 
proposed PM2.5 standards. States should consider the feasibility 
of siting new transport/background and/or visibility monitoring 
locations at or near mandatory Federal Class I areas currently without 
an IMPROVE site so that such sites could provide data to characterize 
both fine particle levels and visibility in or near Class I areas. It 
is EPA's intent that monitoring conducted for purposes of the PM 
primary and secondary NAAQS (including background and transport sites), 
and for visibility protection be undertaken as one coordinated national 
PM monitoring program, rather than as a number of independent networks.
    It is recognized by EPA as well as many outside groups including 
the Clean Air Act Advisory Committee's Subcommittee on Ozone, 
Particulate Matter, Regional Haze Implementation Programs and the 
National Research Council in its 1993 report ``Protecting Visibility in 
National Parks and Wilderness Areas'' that chemical speciation of PM 
data would permit development of more effective control strategies to 
better target those sources of emissions that are causing or 
contributing to elevated levels of PM2.5 and PM10. Speciation 
of PM2.5 data can also be used to develop reliable estimates of 
seasonal and annual average visibility conditions.
    Because of the costs associated with conducting filter analysis on 
a routine basis, this proposal only requires filters to be archived so 
they are available for analysis on an as needed basis. The EPA requests 
comment, however, on the extent to which chemical speciation should be 
conducted. This would include: (1) Whether specific monitoring sites 
should be designated for such analyses; (2) the criteria to be

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used to select sites for speciated sampling and analysis; (3) the 
extent and frequency to which speciation should be required by EPA for 
at least some monitoring stations and (4) the need for monitoring 
methodologies not described in this proposal which may be needed to 
facilitate compositional analysis. The EPA recognizes that there is a 
need for speciation and other specialized monitoring efforts which are 
not specifically required by this proposed rule. Accordingly, EPA will 
give these PM monitoring efforts high priority in its section 105 
grants program. The Administrator solicits comment on the appropriate 
portion of the nation's monitoring resources which should be dedicated 
to speciation and collection of special study data relative to the 
siting and collection of mass measurements for purposes of comparisons 
to the NAAQS and visibility assessments at permanent and temporary 
monitoring stations. The estimated cost for the new PM monitoring 
program is discussed further in Section IV. R.
    Finally, in anticipation of a new regional haze program and 
associated additional monitoring requirements, EPA also requests 
comment on ways that the future PM and IMPROVE networks can be 
coordinated to conserve resources and serve the goals of both the PM 
and regional haze implementation program.
    This proposed rulemaking is taken in conjunction with the proposed 
revisions to the PM NAAQS published elsewhere in today's Federal 
Register and pertains to changes in the ambient air monitoring 
requirements for particulate matter contained primarily in 40 CFR part 
58. A new Federal Reference Method for PM2.5, and changes to the 
definition of PM10 measurements are proposed in a new Appendix L 
and revisions to Appendix J respectively in 40 CR part 50. The 
effective date of these proposed monitoring regulations would be 6 
months after the actual promulgation date. The EPA is soliciting 
comment on all aspects of all of the proposed rules.

III. Proposed Revisions to Part 53

A. Designation of Reference Methods for PM2.5

    The specifications for reference methods for PM2.5 are 
described in Appendix L to part 50, proposed elsewhere in this issue of 
the Federal Register. The performance-based specifications for the 
operational aspects of a reference method sampler allow various sampler 
manufacturers to design and fabricate different samplers that would 
meet the specifications. Accordingly, multiple PM2.5 reference 
methods are expected to become available from several manufacturers, as 
is the case for reference methods for PM10 and most gaseous 
criteria pollutants. Similarly, each reference method for PM2.5, 
based on a particular sampler, would be formally designated as such by 
the EPA under new provisions added to part 53.
    These new provisions, primarily contained in a new subpart E, would 
require that the applicant submit information and documentation to 
demonstrate that a candidate reference method sampler meets the design 
specifications set forth in Appendix L of part 50. The provisions would 
also require that the applicant carry out specific tests to demonstrate 
that the sampler meets all performance specifications. The nature of 
these tests and the requirement that they be carried out by the 
applicant rather than the EPA is consistent with the current 
requirements in part 53 for designating reference methods for other 
criteria pollutants.
    Since the critical inlet and particle size separation components of 
the sampler are specified by design, no wind tunnel or aerodynamic 
performance tests of these components would be required. But 
documentation would be required to demonstrate that samplers to be sold 
as reference methods would be manufactured under an effective quality 
control system, such as required in an International Organization for 
Standardization (ISO) 1 9001-certified facility, or a quality 
control system otherwise certified to meet similar requirements. 
Specific tests would be required to verify that the critical PM2.5 
impact or jet diameter was within the design specifications, and that 
the surface finish of surfaces required to anodized meets the surface 
finish specifications. Also, a checklist certifying that reference 
method samplers are or will be manufactured under an acceptable quality 
assurance system would have to be completed by an ISO-certified or 
equivalent auditor and submitted initially and annually.
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    \1\ The ISO certification ensures compliance to international 
manufacturing standards from the design and engineering 
specifications. An ISO certification, or its equivalence for the 
manufacturing of the reference samplers is consistent with National 
Technology Transfer and Advancement Act Section 12(d), 15 U.S.C. 
Section 272 (1996).
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    The performance tests for reference method samplers would focus on 
testing of the sampler's operational performance parameters, the 
accuracy of its measurement systems, its field precision, and various 
other sampler control functions. A comprehensive test procedure is 
proposed for testing a representative candidate sampler for correct 
flow rate, flow rate regulation, flow rate measurement accuracy, 
ambient air temperature and barometric pressure measurement accuracy, 
filter temperature control and measurement accuracy, and sampling time 
accuracy. This test procedure would require a temperature-controlled 
environmental test chamber, a technique to simulate reduced barometric 
pressure, and facilities to generate simulated solar radiation. Other 
specific tests are proposed to test the sampler's post-sampling filter 
temperature control, leak check procedure, flow rate cut off function, 
and field operational precision. It should be noted that work to test 
the feasibility of these proposed test procedures has not been 
completed at this time; therefore, some technical changes to the 
proposed test procedures may be necessary following the results of that 
work.

B. Designation of Equivalent Methods for PM2.5

    In keeping with the EPA's largely performance-based approach for 
specification of measurement methods for environmental pollutants, 
provision is also proposed for designating equivalent methods for 
PM2.5. These provisions are contained in proposed additions to 
subparts A and C and proposed new subparts E and F of part 53. To 
minimize the number and extent of performance tests to which candidate 
equivalent methods would be subjected, three classes of equivalent 
method are proposed to be defined.
    The first class (Class I) would include PM2.5 methods based on 
samplers that are very similar to a reference method sampler as 
specified in appendix L to part 50. Class I would primarily include 
methods based on samplers whose primary difference from reference 
method samplers is one or more modifications necessary to provide 
capability for collection of several sequential samples automatically 
without intermediate operator service. Samplers capable of collecting 
multiple sequential samples are important because the sampling 
schedules proposed in Sec. 58.13 of part 58 call for daily sampling for 
certain SLAMS. With such a requirement, there is an expected need for 
samplers that will permit the collection of the required daily samples 
without the need for an operator to visit the site on a daily basis or 
for installing multiple samplers at the site. (Since the samplers would 
need to sample from midnight to midnight, a minimum of two single day 
samplers would be

[[Page 65784]]

required for full daily sampling; however, as a practical matter, 
additional single day samplers would generally be needed at a daily 
monitoring site to cover weekends, holidays, and personnel and 
scheduling logistics.) A sampler capable of automatically collecting 
five sequential samples would permit twice-weekly servicing of a 
monitoring site (assuming sample filters can be retrieved and reloaded 
on the inactive channels without affecting the actively sampling 
channel).
    Since the design of sequential samplers is not specified 
explicitly, sampler manufacturers would be able to design and develop 
their own techniques to provide for this capability. Where the 
sequential sample technique consists of relatively minor or simple 
modifications of the reference method sampler, the sampler would be 
classified as a Class I candidate equivalent method. (Sequential 
samplers would also be possible as Class II or III equivalent methods.)
    Class I equivalent method sequential samplers would have to be 
tested to make sure that the modifications required to provide for 
sequential sampling do not significantly compromise sampler 
performance. However, because of their similarity to the reference 
method sampler, the only additional test requirement for most Class I 
candidate equivalent methods--in addition to the tests and performance 
requirements applicable to reference method samplers--would be a test 
for possible loss of PM in any new or modified components in the 
sampler inlet upstream of the sample filter. This additional test for 
Class I samplers is set forth in the proposed new Subpart E, along with 
the tests for reference method samplers.
    Class II equivalent methods would include all other PM2.5 
methods that are based on a 24-hour integrated filter sample which is 
subjected to subsequent moisture equilibration and gravimetric mass 
analysis, but with an associated sampler having substantial deviations 
from the design or performance specifications for reference method 
samplers. These samplers may have a different inlet, a different 
particle size separator, a different volumetric flow rate, a different 
filter or filter face velocity, or other significant differences. More 
extensive performance testing would be required for designation of 
Class II candidate equivalent methods, with various tests required 
depending on the nature and extent of the differences between the 
candidate sampler and specified reference method samplers. These tests 
include a full wind tunnel evaluation, a wind tunnel inlet aspiration 
test, a static fractionator test, a fractionator loading test, and a 
volatility test. The tests and their specific applicability to various 
types of candidate Class II equivalent method samplers are set forth in 
proposed new subpart F.
    Finally, Class III equivalent methods would include any candidate 
PM2.5 methods that could not qualify as Class I or Class II. This 
class would include any filter-based integrated sampling method having 
other than a 24-hour PM2.5 sample collection interval followed by 
moisture equilibration and gravimetric mass. More importantly, class 
III would also include filter-based continuous or semi-continuous 
methods, such as beta attenuation instruments, harmonic oscillating 
element instruments, and other complete in situ monitor types, as well 
as non-filter-based methods such as nephelometry or other optical 
instruments.
    The testing requirements for designation of Class III candidate 
methods would be the most stringent, since quantitative comparability 
to the reference method would have to be shown under various potential 
particle size distributions and aerosol composition. However, because 
of the variety of measurement principles and types of methods possible 
for Class III candidate equivalent methods, the test requirements would 
have to be individually selected or specifically designed or adapted 
for each such type of method. Therefore, the EPA believes that it is 
not practical to attempt to develop and explicitly describe the test 
procedures and performance requirements for all of these potential 
Class III methods a priori. Rather, it is proposed that the test 
procedures and performance requirements applicable to specific Class 
III candidate methods would be determined by the EPA on a case-by-case 
basis upon request, in connection with each proposed or anticipated 
application for a Class III equivalent method determination. In this 
regard, the EPA is interested in receiving comments pertinent to the 
nature and extent of tests that would be appropriate and effectual in 
determining the performance of various types of Class III candidate 
equivalent methods relative to the performance of reference methods for 
PM2.5.
    All classes of candidate equivalent methods would have to be field-
tested to determine their comparability to measurements obtained with 
collocated reference methods. For Classes I and II, these collocated 
field test requirements are specified explicitly in Subpart C, which is 
proposed to be revised to include the specific requirements for 
PM2.5 candidate equivalent methods. The proposed requirements for 
PM2.5 methods are generally patterned after the existing 
requirements for PM10 candidate methods.
    However, because of the need for greater measurement precision for 
PM2.5, the comparability specifications, summarized in Table C-4, 
are somewhat more stringent than those previously established for 
PM10. Also, for Class II candidate equivalent methods--where two 
different test sites are required--more definitive specifications are 
proposed for the tests sites in terms of the PM2.5 to PM10 
measurement ratio for the test samples. This is necessary because 
experience with PM10 measurements has indicated that PM 
measurements made with dissimilar samplers are often considerably 
affected by differences in the ``character'' of the PM at different 
monitoring sites, as represented by differences in particle size 
distribution, composition, density, humidity, and other factors. For 
purposes of the comparability test, the character of the PM at each 
test site is represented by the measured PM2.5 to PM10 ratio, 
which must be greater than 0.75 for one site and less than 0.40 at the 
other site. (More definitive tests of PM character at the test site are 
deemed too difficult or costly to carry out for purposes of the 
comparability test.) Insuring comparability to reference method 
measurements at sites having profoundly different character of PM is 
critically important for Class II (and Class III) candidate equivalent 
methods. Note, however, that the PM2.5 to PM10 ratio 
requirement does not apply to testing of Class I candidate methods, 
where only one test site is required.

C. Quality Assurance

    Accurate measurement of ambient particulate matter concentrations 
is severely hampered by the impracticality of providing PM 
concentration standards for field (or even laboratory) testing of 
ambient samplers or monitors. Therefore, it is necessary to rely on a 
specific, well-defined reference method, uniformity of reference method 
devices and procedures, and continual assessment of bias and operating 
precision. For the purposes of this regulation, PM2.5 
concentration measurements would be referenced to measurements made 
with a reference method sampler in accordance with the reference method 
as specified in Appendix L of part 50 of this chapter. Monitoring for 
PM2.5 requires greater attention to achieving data of high 
quality, with minimal imprecision and

[[Page 65785]]

relative error. These higher quality monitoring data are essential to 
reduce the chance that PM2.5 measurements would potentially cause 
unjustified health risk to the population, when measurements 
underestimate true concentrations, or unnecessary control requirements, 
when measurements overestimate the true concentrations.
    To meet a data quality objective of 15% precision for 
ambient PM2.5 attainment measurements, enhanced quality assurance 
would be required in all areas relating to sampler performance 
including sampler manufacturing and sampler operation. This is 
especially important because a reference method sampler is proposed to 
be used to audit other field monitors, as described later.
    Designated reference and equivalent method samplers and monitors 
would be required to be manufactured in a manufacturing facility that 
is either (1) an ISO 9001-registered manufacturing facility, with 
registration maintained continuously, or (2) a facility that can be 
demonstrated, on the basis of information submitted to the EPA, to be 
operated according to an EPA-approved and periodically audited quality 
system which meets, to the extent appropriate, the same general 
requirements as for an ISO-registered facility. (This requirement is 
referred to in this document as an ISO-registered facility, regardless 
of the procedure taken for EPA approval.)
    In addition to the ISO registration (or equivalent) requirement, a 
quality assurance manufacturing checklist would have to be submitted 
annually attesting that the appropriate quality assurance procedures 
are routinely implemented in the manufacturing of samplers sold as 
reference or equivalent method samplers. This check list would have to 
be signed by an ISO-certified auditor or by an auditor who, based on 
information submitted to the EPA, meets the same general requirements 
as provided for ISO-certified auditors. (Similarly, an auditor approved 
by EPA through either mechanism is referred to in this document as an 
ISO-certified auditor.) This requirement allows for the demonstration 
of consistency in production and sustained uniformity in design and 
operation. Further, all testing related to an application for a 
reference or equivalent method determination under part 53 would have 
to be carried out in accordance with ISO 9001 and ANSI/ASQC E4 
standards.
    It is believed that these requirements are necessary to insure that 
all samplers or analyzers sold as reference or equivalent methods are 
manufactured to the high standard required to achieve the needed data 
quality. These procedures are in keeping with the developing 
international standards for manufacturing in this and other industries. 
However, comments on the appropriateness and impact of these proposed 
requirements are solicited. While these requirements are currently 
proposed to apply only to the manufacture of PM2.5 monitors, 
extending these requirements to the manufacture of PM10 monitors 
and possibly other types of SLAMS monitors will likely be considered at 
a later time.
    A new operational requirement would also have to be met by each 
PM2.5 sampler or monitor to retain its designation as a reference 
or equivalent method. Each user agency operating a SLAMS site would be 
required to obtain at least 6 collocated measurements (audits) per year 
with a reference method ``audit'' sampler for each routinely operating 
PM2.5 monitor. The data obtained from these collocated audits 
would be used to determine a national network integrated operating 
precision and relative accuracy performance indicator for each 
designated method. A PM2.5 monitoring method that fails to meet 
the specified limits for this performance indicator would be subject to 
possible cancellation of its reference or equivalent method designation 
under the provisions of Sec. 53.11. For more information on this 
provision, see section 6 of proposed revisions to Appendix A of part 58 
and its associated preamble, set forth elsewhere in this Federal 
Register.

D. Other Changes

    A number of other relatively minor technical changes are proposed 
to Appendix A, some of which affect designation of reference or 
equivalent methods for other criteria pollutants as well as for 
PM2.5. These changes include new definitions and clarifications of 
existing definitions in Sec. 53.1; clarifications of the reference and 
equivalent method designation requirements for methods for all 
pollutants, including the new classes of equivalent methods for 
PM2.5 and a new table summarizing all the designation 
requirements; and updating of the name of the EPA laboratory to which 
applications are to be sent. Additional changes include proposed 
clarifications of the content of information required in submitted 
applications regarding the candidate method test data, manufacturing 
quality assurance system, and product warranty, and the content 
required in the operation or instruction manual associated with a 
candidate method sampler or analyzer.
    Also, because of the increasing complexity of anticipated candidate 
methods for all criteria pollutants, an increase in the EPA's time 
limit for processing applications for reference and equivalent methods, 
from 75 to 120 days, is proposed. Finally, it is proposed (under 
Sec. 53.4) that applicants for a PM2.5 reference or equivalent 
method determination be required to provide a sampler or analyzer that 
is representative of the one associated with the candidate method for 
inspection and possible testing by the EPA in connection with 
processing of the application.

IV. Discussion of Proposed Revisions to Part 58

A. Section 58.1--Definitions

    The revisions proposed today would revise the definition of the 
term traceable and add definitions of the terms Consolidated 
Metropolitan Statistical Area (CMSA), core SLAMS, equivalent methods, 
Metropolitan Statistical Area (MSA), monitoring planning area (MPA), 
monitoring plan, PM2.5, Primary Metropolitan Statistical Area 
(PMSA), population-oriented, reference method, SAZ (SAZ), SPM fine 
monitors, and Annual State Monitoring Report.

B. Section 58.13--Operating Schedule

    1. PM10 Sampling. The current operating schedule for PM10 
is based primarily on an analysis of the ratio of measured PM10 
concentrations to the controlling PM10 standard. Depending upon 
the ratio, the sampling frequency is either every day, every other day, 
or every sixth day. The proposed operating schedule would reduce the 
sampling frequency at all PM10 sites to once every sixth day.
    The Administrator has proposed a new 24-hr PM10 standard based 
on the 98th percentile which offers a more stable statistical form. She 
has also solicited comment on the need to retain any 24-hour PM10 
standard. Unlike the current 24-hr PM10 standard, the proposed 
standard, if adopted, would not place emphasis on the most extreme 24-
hr concentrations, especially in areas influenced by fugitive dust. 
Furthermore, more emphasis for control requirements is anticipated to 
be placed on annual average concentrations and fewer nonattainment 
areas (i.e. violation areas) are expected to be based on peak daily 
concentrations. Consequently, 1 in 6 day sampling should be sufficient 
to support the new PM10 NAAQS and a less dense monitoring network 
would also be needed. Comments are solicited on the appropriate 
sampling schedules

[[Page 65786]]

for PM10 sites if the 24-hour NAAQS for PM10 is retained.
    2. PM2.5 Sampling. Core PM2.5 SLAMS (including NAMS and 
Core SLAMS collocated at PAMS sites) would be required to sample every 
day, unless an exception is approved by EPA during established seasons 
of low PM pollution during which time a minimum of once in 6 days 
sampling would be permitted. Non-core SLAMS sites would generally be 
required to sample a minimum of once every sixth day, although episodic 
or seasonal sampling could also be possible (e.g., in areas where 
significant violations of the 24-hour NAAQS are expected or at sites 
heavily influenced by regional transport or episodic conditions). 
Special purpose monitors, however, may sample on any sampling schedule.
    There is currently very little PM2.5 measurement data. New 
networks must be established as expeditiously as possible to help 
characterize the nature and extent of PM2.5 ambient air quality 
nationwide. Daily sampling for PM2.5 is especially important 
during the first few years of the new PM2.5 monitoring program to 
allow for the collection of complete sets of data in order to help with 
identifying temporal patterns and to understand the episodic behavior 
of fine particles.
    Although daily sampling with manual methods is labor intensive due 
to site visits and filter equilibration and weighing, semi-automatic 
sequential samplers are anticipated to be approvable as class I 
equivalent samplers (under the provisions of Part 53) which will 
simplify the data collection process. The EPA solicits comments on the 
need to extend the start date for a requirement to perform everyday 
sampling until the time when Class I equivalent samplers have been 
approved by the Agency.
    In addition, alternative PM2.5 operating schedules which 
combine intermittent sampling with the use of acceptable continuous 
fine particle samplers are approvable at some core sites. This 
alternative is intended to give the States additional flexibility in 
designing their PM2.5 monitoring networks and to permit data from 
continuous instruments to be telemetered. This would facilitate public 
reporting of fine particle concentrations, allow air pollution alerts 
to be issued and episodic controls to be implemented (as currently done 
in woodburning areas for PM10). Furthermore, this would permit 
monitoring agencies to take advantage of new and improved monitoring 
technologies that should become available during the first few years 
following the promulgation. As proposed, applicability of the 
alternative depends on population size of the monitoring area and 
PM2.5 air quality status.
    After the initial 3 years of PM2.5 data collection and after 
characterization of PM2.5 levels, determination of violation areas 
and development of State Implementation Plans), reductions in the 
frequency of PM2.5 sampling may be appropriate. The EPA welcomes 
comments on the need for continued long-term monitoring with reference 
or equivalent samplers on an every day schedule at some or all 
monitoring stations and on the appropriateness of the criteria for 
allowing alternative schedules.

C. Section 58.14--Special Purpose Monitors

    Special purpose monitoring is needed to help identify potential 
problems, to help define boundaries of problem areas, to better define 
temporal (e.g., diurnal) patterns, to determine the spatial scale of 
high concentration areas, and to help characterize the chemical 
composition of PM (using alternative samplers and supplemental 
analyzers), especially on high concentration days or during special 
studies. Special purpose monitors are an important part of the overall 
PM monitoring program, and sufficient EPA and State resources must be 
allocated for their use.
    Today's revisions propose that special purpose PM2.5 and 
PM10 monitors may sample with any measurement method on any 
sampling schedule. However, the data from SPM's would not be used for 
attainment/nonattainment designations if the monitoring method is not a 
reference or equivalent method or does not meet the requirements of 
Section 2.4 of Appendix C of Part 58. Moreover, in order to encourage 
the deployment of SPM's, today's revisions propose that nonattainment 
designations will not be based on data produced at an SPM site with any 
monitoring method for a period of 3 years following the promulgation 
date of the NAAQS.
    The rationale for this concept is based on the need for to 
encourage building from ``ground zero'' a monitoring infrastructure. 
Such an infrastructure is needed because of the complexity of the 
PM2.5 problem and the relative paucity of PM2.5 data to 
determine where problem areas lie, and the lack of information about 
sources and formation of aerosols in particular areas. The requirements 
for the NAMS, minimum core SLAMS, and minimum additional SLAMS sites, 
described in this notice, are designed to provide much of the 
information needed to merely define the location of problem areas.
    There is a need, however, to look beyond this minimal network to 
create an ``optimal'' network that would gather air quality data over a 
wider geographic area. The optimal network would consist of SLAMS 
monitors in addition to the required minimums and also SPM's. There are 
several reasons for a moratorium on regulatory use of data from the 
during the first 3 years following promulgation of the NAAQS:
    (1) SPM data have historically supplemented the SLAMS network to 
provide the States with a flexible monitoring program. Although the SPM 
monitoring does not have to use reference or equivalent monitors, the 
States tend to use these monitors for data collection. And although SPM 
data are not required to be submitted to EPA, the States tend to enter 
all such data into the AIRS data base. Because of the paucity of 
PM2.5 data, we want to encourage both the collection--with 
reference or equivalent monitors--and the reporting of as much new 
PM2.5 data as possible. This includes SPM data.
    (2) There is a general reluctance among State and local governments 
and businesses to monitor ambient air quality beyond those minimum 
requirements contained in regulations promulgated by the Environmental 
Protection Agency (EPA) in the Code of Federal Regulations at Part 58. 
The reluctance is based in part on the fact that areas have 
historically been designated to nonattainment where monitoring shows 
violations of the NAAQS and then classified according to the 
seriousness of the air pollution problem. Currently, such a 
nonattainment designation and classification automatically trigger the 
State implementation attainment planning and demonstration 
requirements, potential stationary and mobile source emission controls, 
nonattainment new source review for sources wanting to locate or expand 
in the new nonattainment area, and possibly additional requirements 
relating to nonattainment of the NAAQS. Thus, to many affected parties, 
the current regulatory system results in a disincentive for detecting 
violations.
    (3) The EPA is evaluating a concept involving the identification of 
areas that have measured or modeled violations and subsequent 
identification of other areas whose emissions contribute to those 
violations. The new required PM2.5 monitoring network, however, 
may be insufficient to determine all such violation areas and 
contributing areas, and therefore additional monitors may be desirable. 
Ambient air

[[Page 65787]]

monitoring will play an important and expanded role in defining 
violating and contributing areas; with a moratorium on the regulatory 
use of SPM data, States and businesses would have an additional 
incentive to monitor for data to more accurately determine the extent 
of these areas.
    (4) During the initial stages of development of a new PM2.5 
network, there is a greater need for experimental sampling--to move 
samplers around, to sample for short periods of time, and to utilize 
different methods. Incomplete data sets may not be fully representative 
of local air quality. For these and other similar reasons, there is a 
need for a pilot network that would not be subjected to the same rules 
as the full SLAMS network.
    (5) Finally, collecting data at a number of sites beyond either the 
minimum or optimal number proposed in these regulations would support 
modeling studies to better define pollution problems, identification of 
potential pollution problems for enhanced air management programs, the 
design and implementation of episodic control plans to encourage quick 
response actions for voluntary emission reduction measures to lower 
pollution and thereby possibly avoiding nonattainment or ``bump-ups'', 
and to measure progress toward attainment by relating air quality to 
population.
    The system of SPM's would at first not be part of the full required 
or even the ``optimal'' network. To provide the best kind of 
information, EPA believes that properly sited Federal Reference or 
Equivalent Methods be used for these SPM efforts in order to collect 
technically credible data. The EPA also believes that data from those 
efforts be reported to AIRS so that they are generally available to the 
public at large and to those who need them for understanding the nature 
of the problem and for developing solutions and control strategies.
    In proposing a 3-year moratorium on the regulatory use of SPM data, 
EPA is trying to establish an incentive for States to engage in this 
additional SPM monitoring using properly sited Federal Reference or 
Equivalent Monitors. The data from these SPM's would supplement the 
data collected by SLAMS sites. Although the SPM data would be exempt 
from regulatory use during the 3-year moratorium, they would 
nevertheless be evaluated by the State during its annual SLAMS network 
review. A notice of NAAQS violations resulting from PM SPM``s should be 
reported to EPA, such high concentrations should be evaluated by the 
State in the design of its overall SLAMS network and considered by EPA 
in its review and approval of the State''s monitoring plan. Therefore, 
during the first 3 years, the SPM data would still play an important 
role in the regulatory process. After the proposed 3-year exemption 
period, SPM locations should be considered as potential SLAMS in the 
State's development and subsequent EPA reviewal process of their 
monitoring plan network, if the sites record high concentrations which 
indicate potential violations of the PM NAAQS (for either PM10 or 
PM2.5) and have been operating for at least 6 months.
    The EPA could have taken a different approach to this problem and 
not propose a moratorium on the regulatory use of data from the SPM 
sites. States would still be able to deploy SPM monitors in ways to 
avoid legal consequences if an exceedance of the NAAQS were found. For 
instance, any State may use non-reference or non-equivalent methods, 
which do not meet EPA specifications. Any State could site monitors so 
that they do not meet EPA siting criteria. Such monitoring would avoid 
the above-described legal entanglements associated with any NAAQS 
exceedances, because the data collected would not, under current EPA 
regulations, be valid for use in comparison to the NAAQS. Moreover, any 
State could simply not submit the SPM data to EPA.
    The approach described in the above paragraph, however, does have 
major disadvantages. For instance, an approach that uses unacceptable 
monitors or siting would result in data that--even if close to being 
representative of the area or what a properly sited acceptable monitor 
would measure, would still be clouded with questions regarding its 
accuracy or precision, which would limit their value in the kinds of 
analyses mentioned above. In the case of data simply not submitted to 
EPA, data would not be available to either other States that would be 
working on development of a solution to the PM-fine problem, or, more 
important, to the public at large so that they could be aware if there 
really are problems detected by the monitor.
    In light of these concerns, EPA's proposal is an attempt to take a 
more straightforward approach, which will encourage collection of 
additional data that is technically credible and publicly available, 
and therefore address the Act's mandate for EPA to take the lead in 
this matter, as found in section 103(c).

D. Section 58.15--PM2.5 NAAQS Eligible Monitors

    This new section is proposed to define the PM2.5 monitors 
eligible for use in determining compliance with the PM2.5 annual 
and 24-hour NAAQS. The EPA proposes that States identify on EPA's AIRS 
monitoring site file, all PM2.5 sites eligible for both annual 
NAAQS comparisons and 24-hour comparisons and those only eligible for 
24-hour (daily) comparisons. The former sites are intended to be 
population oriented spatial averaging sites and the latter are intended 
to represent population-oriented ``hot spot'' locations. The reasons 
for the different types of monitors are discussed in the preamble to 40 
CFR part 50.

E. Section 58.20--Air Quality Surveillance: Plan Content

    The revisions proposed today would require States to submit a PM 
monitoring plan to the Regional Administrator within 6 months of the 
effective date promulgation. The monitoring plan would describe the PM 
monitoring strategy based on the use of SLAMS (including NAMS and PAMS) 
and SPM's for PM10 and PM2.5; describe the phase-in of 
PM2.5 monitors and changes in the existing PM10 monitoring 
program; describe monitoring objectives and scales of 
representativeness to facilitate subsequent interpretation of data; 
define sampling schedules; denote sites intended for comparison to the 
PM NAAQS; and define the monitoring planning areas (MPA's) and SAZ's 
(SAZ's) within the State. It should also reference the revised quality 
assurance plan which is required by Appendix A to Part 58. In regard to 
the use of air quality data for making comparisons to the NAAQS and 
other SIP related purposes, the monitoring plan shall also describe the 
SPM's whose data the State intends to use for SIP purposes. The 
monitoring plan must also provide for an annual review for termination, 
relocations, or establishment of new SLAMS or core SLAMS.

F. Section 58.23--Monitoring Network Completion

    Under the revisions proposed today, the PM networks would be 
expected to be completed within 3 years of the effective date of 
promulgation. While new PM2.5 networks are developed, existing 
PM10 networks should be considered for reductions consistent with 
the goals stated in the background section earlier. For PM2.5, a 
3-year phase-in would be used. The proposed schedule for deployment of 
new required PM2.5 monitors is described

[[Page 65788]]

here. During the first year, a minimum of one monitoring planning area 
per State would be required to have core PM2.5 SLAMS. This area 
would be selected by the State according to the likelihood of observing 
high PM2.5 concentrations and according to the size of the 
affected population. In addition, one PM2.5 site would be 
collocated at one site in each of the PAMS areas. During the second 
year, all other core population-oriented PM2.5 SLAMS, and all core 
background and transport sites, must be fully operational. During the 
third year, any additional required PM2.5 (non-core) SLAMS must be 
fully deployed and all NAMS sites must be selected from core SLAMS and 
proposed to EPA for approval.

G. Section 58.25--System Modification

    No changes to the regulatory language are proposed to Sec. 58.25; 
however, under the revisions proposed today, the annual system 
modifications review must include changes to PM2.5 site 
designations (e.g., NAAQS comparison sites), the number or boundaries 
of monitoring planning areas and/or SAZ's.

H. Section 58.26--Annual State Monitoring Report

    Under the current regulations, States are required to submit an 
annual SLAMS data summary report. Under today's proposed revisions, 
this report shall be expanded to include additional information. First, 
the new State Monitoring report shall describe the proposed changes to 
the State's Monitoring Plan, as defined in Sec. 58.20. It shall include 
a new brief narrative report to describe the findings of the annual 
SLAMS network review, reflecting within year and proposed changes to 
the State air quality surveillance system, and to provide information 
on PM SPM's and other PM sites described in the monitoring plan 
regardless of whether data from the stations are submitted to EPA 
(including number of monitoring stations; general locations; monitoring 
objective; scale of measurement; and appropriate concentration 
statistics to characterize PM air quality such as number of 
measurements, averaging time, and maximum, minimum, and average 
concentration). The latter is needed for EPA to ensure that a proper 
mix of permanent and temporary monitoring locations are used, that 
populated areas throughout the nation are monitored, and to provide 
needed flexibility in the State monitoring program. The content of this 
brief report shall be in accordance with EPA guidance, and will be 
available at the time of promulgation of the final Part 58 rule.
    Next, States would be required to describe the proposed changes to 
existing PM networks. Proposed changes to the existing networks may 
include modifications to the number, size, or boundaries of Monitoring 
Planning Areas or SAZ's, number and location of PM SLAMS; number or 
location of core PM2.5 SLAMS; alternative sampling frequencies 
proposed for PM2.5 SLAMS (including core PM2.5 SLAMS and 
PM2.5 NAMS); core PM2.5 SLAMS to be designated PM2.5 
NAMS; and PM SLAMS to be designated PM NAMS. SLAMS with NAAQS 
violations should be considered to become new or replacement core 
sites, and SPM's with NAAQS violations could become part of the SLAMS 
network. The proposed changes should be developed in close consultation 
with the appropriate EPA Regional Office and submitted to the 
appropriate Regional Office for approval. The portion of the plan 
pertaining to NAMS would be submitted to the Administrator (through the 
appropriate Regional Office).
    Finally, as a continuation of current regulations, the States shall 
be required to submit the Annual SLAMS summary report and to certify to 
the Administrator that the SLAMS data submitted are accurate and in 
conformance with applicable Part 58 requirements. Under the revisions 
proposed today, States would also be required to submit annual 
summaries of SPM data to the Regional Administrator for sites included 
in their Monitoring Plan and to certify that such data are similarly 
accurate and likewise in conformance with applicable Part 58 
requirements or other requirements approved by the Regional 
Administrator, if these data are intended to be used for SIP purposes.
    During the first 3 years following promulgation, the monitoring 
plan and any modifications of it must be submitted to EPA by July 1 
(starting on the year following promulgation) or by alternate annual 
date to be negotiated between the State and Regional Administrator, 
with review and approval/disapproval by the Regional Administrator 
within 45 days. After the initial 3-year period or once a SAZ has been 
determined to be violating any PM2.5 NAAQS, then changes to a 
monitoring planning area will require public review and notification to 
ensure that the appropriate monitoring locations and site types are 
included. Specific comment on or suggestions for alternate procedures 
that are not unduly time consuming or burdensome to allow public review 
and comment on changes in MPA's, SAZ's, or other elements of a 
monitoring plan developed by a State or local air pollution control 
agency are especially welcome.

I. Section 58.30--NAMS Network Establishment

    The revision proposed today would designate 6 months after the 
effective date of promulgation as the date by which the NAMS network 
portion (to be derived from core PM2.5 SLAMS) of each State's 
SLAMS network must be fully described and documented in a submittal to 
the Administrator (through the appropriate EPA Regional Office). At 
this time, a State's NAMS PM10 network must be reaffirmed if no 
changes are made to the existing network and if changed must also be 
fully described and documented in a submittal to the Administrator 
(through the appropriate EPA Regional Office).

J. Section 58.31--NAMS Network Description

    Today's proposed revision would require that the NAMS network 
description also include for PM2.5 the monitoring planning area, 
SAZ, and the site code designation to identify which site will be used 
to determine violation of the appropriate NAAQS (annual or 24-hour).

K. Section 58.34--NAMS Network Completion

    The revision proposed today would designate 3 years after the 
effective date of promulgation as the date by which the State must have 
all PM2.5 NAMS in operation, and 1 year after the effective date 
of promulgation as the date by which the State must have made all 
changes to the existing PM10 NAMS.

L. Section 58.35--NAMS Data Submittal

    This section defines the data submittal requirements for NAMS and 
SLAMS. Consistent with current requirements, only the total mass 
derived from PM10 and PM2.5 SLAMS would be required to be 
submitted to EPA. However, EPA encourages reporting all data from 
monitors proposed in the State monitoring plan. These optional data 
would include data from SPM's and compositional data from all monitors.

M. Appendix A--Quality Assurance Requirements for SLAMS

    Meeting the more stringent data quality objectives for ambient 
PM2.5 monitoring will require considerably enhanced quality 
assurance in the areas of sampler operation, filter handling, data 
quality assessment, and other

[[Page 65789]]

operator-related aspects of the PM2.5 measurement process.
    Most operational quality control aspects are specified in Appendix 
A in general terms. For PM2.5, however, explicit, more stringent, 
requirements are proposed for sample filter treatment--including the 
moisture equilibration protocol, weighing procedures, temperature 
limits for collected samples, and time limits for prompt analysis of 
samples. These requirements, which are specified in the reference 
method set forth in proposed new Appendix L to part 50, will help to 
control measurement precision. Additional or supplemental detailed 
quality assurance procedures and guidance for all operator-related 
aspects of the PM2.5 monitoring process will be developed and 
published as a new Section 2.12 of the EPA's, Quality Assurance 
Handbook for Air Pollution Measurement Systems series to assist 
monitoring personnel in maintaining high standards of data quality.
    Procedures for continually assessing the operational quality of the 
SLAMS monitoring data are specified explicitly in Appendix A of part 
58. Perhaps the most significant new data quality assessment 
requirement proposed for PM2.5 monitoring is the requirement that 
each routinely operating PM2.5 ``compliance'' monitor must be 
``audited'' at least 6 times per year. A compliance monitor is a 
monitor at a site which is included in the PM monitoring plan and whose 
data is intended for comparison to the NAAQS as described in Appendix 
D. This is the first time a requirement has been proposed to assess the 
relative accuracy of the mass concentration measured by a SLAMS PM 
monitor.
    Each of these 6 ``audits'' would be performed by the monitoring 
agency and would consist of concurrent operation of a collocated 
reference method audit sampler along with the routinely operated 
compliance sampler or monitor. The data from these collocated audits 
would be pooled by the EPA to assess the performance of PM2.5 
monitoring methods on a national basis and for each reporting 
organization. These data would also be used in a screening test of the 
performance of individual monitors at each monitoring location. Six has 
been determined to be the minimum number of audit data points needed to 
yield a reasonable assessment of individual monitor operational 
performance on an annual basis. This number is analagous to the data 
requirements for the precision and accuracy assessments for PM10, 
PM2.5 and other pollutants described in Section 5.
    The integrated operating precision and relative accuracy, evaluated 
annually, would have to meet a limit of 15 percent. A 
monitoring method that fails this requirement nationally would be 
placed in a probationary status pending resolution of the inadequate 
performance or possible cancellation of its reference or equivalent 
method designation under the provisions of Sec. 53.11 of part 53 of 
this chapter. While this action would not result in immediate 
cancellation of the designation, it would require the method applicant 
(e.g., the manufacturer) to correct the method performance problems or 
to submit alternative evidence or arguments (possibly in collaboration 
with other affected entities) that the method's designation should not 
be canceled.
    Reporting organizations whose monitoring data failed to meet this 
requirement (or are significantly worse than the national norm) would 
be notified that its quality assurance plan or procedures need 
improvement. Similarly, monitoring data from individual sites that fail 
the screening test would require remedial action or replacement of the 
monitoring method. Note, however, that failure of either of these tests 
or the national test would not automatically cause the associated 
monitoring data to be invalid.
    Comments are solicited on these method operating performance audits 
and particularly on the potential use of the audit data by EPA to: (1) 
Determine a national network operating precision and accuracy 
performance indicator for each type of designated method, (2) determine 
the operational performance of methods used by reporting organizations 
relative to the national norm, and (3) consider cancellation of the 
reference or equivalent method designation of methods failing to meet 
the 15 percent operational performance specification.
    Other data assessment requirements proposed in Appendix A for 
PM2.5 monitoring networks are patterned after the current 
requirements for PM10 networks and are intended to supplement the 
audit procedure. PM2.5 network monitors would be subject to 
precision and accuracy assessments for both manual and automated 
methods, using procedures similar or identical to the current 
procedures required for PM10 monitoring networks. Results of these 
field tests performed by the monitoring agencies (along with the 
results of the field audits) would be sent to the EPA, which then would 
carry out the specified calculations. These calculated statistics would 
become part of the annual assessment of the quality of the monitoring 
data.
    For automated methods, the additional assessment of the precision 
would consist of a one-point precision check performed at least once 
every 2 weeks on each automated analyzer used to measure PM2.5. 
This precision check would be made by checking the operational flow 
rate of the analyzer. A standard precision flow rate check procedure 
similar to that currently used for PM10 network assessments is 
proposed. Also proposed is an alternative procedure where, under 
certain specific conditions, it would be permissible to obtain the 
precision check flow rate data from the analyzer's internal flow meter 
without the use of an external flow rate transfer standard. (This 
alternative procedure would also be made applicable to PM10 
methods.)
    The additional accuracy assessment procedure proposed for 
PM2.5 automated methods is also similar to that used for PM10 
networks, although each PM2.5 analyzer would have to be audited 
quarterly rather than annually, as is the current requirement for 
PM10 analyzers. The assessment would be performed on the 
analyzer's operational flow rate using a flow rate transfer standard, 
with the accuracy calculated from the percent difference between the 
actual flow rate and the corresponding flow rate indicated by the 
analyzer.
    For manual methods, an additional precision assessment would be 
calculated from the data collected from collocated samplers, as is 
currently required for manual PM10 methods. The number of 
collocated samplers within each PM2.5 network is proposed to be 
based upon the total number of samplers within the reporting 
organization's network. For 1 to 10 total sites, 1 site would be 
selected for collocation; for 11 to 20 total sites, 2 sites would be 
selected for collocation; and if a reporting organization has over 20 
total sites, then 3 sites would be selected for collocation. As for 
PM10, one sampler of the collocated pair would be designated as 
the primary sampler whose samples would be used to report air quality 
for the site, and the other would be designated as the duplicate 
sampler. The percent differences in measured concentration between the 
two collocated samplers would be used to calculate this additional 
network precision.
    The accuracy of the flow rate system of manual methods for 
PM2.5 would be determined, as for automated methods, by auditing 
each sampler each calendar quarter. Using a flow rate transfer 
standard, each sampler would be audited at its normal operating flow

[[Page 65790]]

rate. The percent differences between these flow rates would be used to 
calculate an additional indicator of accuracy.
    Although the new quality assurance requirements for PM2.5 
would result in an increase in the quality of the PM monitoring data, 
the additional QA/QC checks would entail additional cost to the 
monitoring agency. Some of the new QA/QC assessment requirements may 
somewhat overlap the similar information provided by other checks, such 
as the periodic flow rate checks and the use of collocated samplers in 
monitoring networks. Consequently, the EPA solicits comments on the 
need to maintain all of these QA requirements and also on the adequacy 
of the proposed QA data assessments to ensure the defined quality for 
PM2.5 measurements.
    Table A-1, which summarizes the minimum data quality assessment 
requirements, would be updated to include the new requirements for 
PM2.5 methods, and other minor, mostly editorial changes are 
proposed to Appendix A to update and clarify the language and specific 
requirements.
    A change to section 2.5 of Appendix A is also being proposed to 
provide for technical system audits to be performed by EPA at least 
every three years rather than every year. This change to a less 
frequent system audit schedule recognizes the fact that for many well 
established agencies, an extensive system audit and rigorous inspection 
may not be necessary every year. The determination of the extent and 
frequency of system audits at an even lower frequency than the proposed 
three year interval is being left to the discretion of the appropriate 
Regional Office, based on an evaluation of the Agency's data quality 
measures. This change would afford both the EPA and the air monitoring 
agencies flexibility to manage their air monitoring resources to better 
address the most critical data quality issues.
N. Appendix C--Monitoring Methodology
    Section 2.2 of Appendix C is proposed to be amended to allow the 
use of PM10 monitors as surrogates for PM2.5 monitors for 
purposes of demonstrating compliance with the NAAQS. However, following 
the measurement of a PM10 concentration higher than the 24-hour 
PM2.5 standard or an annual average concentration higher than the 
annual average PM2.5 standard, the PM10 monitor would have to 
be replaced with a PM2.5 monitor. In addition, for NAMS that are 
converted to PM2.5 monitoring from PM10 monitoring, the 
PM10 monitoring must continue concurrently with the PM10 
monitoring for 1 year following the beginning of the PM2.5 
monitoring.
    Appendix C would also be amended to add a new section 2.4 
containing provisions that would allow the use at a SLAMS of a 
PM2.5 method that had not been designated as a reference or 
equivalent method under part 53. Such a method would be allowed to be 
used at a particular SLAMS site to make comparisons to the NAAQS if it 
met the basic requirements of the test for comparability to a reference 
method sampler for PM2.5, as specified in Subpart C of part 53 of 
this chapter, in each of the four seasons of the year at the site at 
which it is intended to be used. A method that meets this test would 
then be further subjected to the operating precision and accuracy 
requirements specified in section 6 of Appendix A of this part, at 
twice the normal evaluation interval (6 audits in 6 months instead of 6 
audits in 12 months). A method that meets these requirements would not 
become an equivalent method, but the method could be used at that 
particular SLAMS site for any regulatory purpose. The method would be 
assigned a special method code, and monitoring data obtained with the 
method would be accepted into AIRS as if they had been obtained with a 
reference or equivalent method. This provision could thus allow the use 
of non-conventional PM2.5 methods, such as optical or open path 
measurement methods, which would be difficult to test under the 
equivalent method test procedures proposed for part 53.
    In addition, Appendix C would also be amended to add two new 
sections. A proposed new section 2.5 would clarify that correlated 
acceptable continuous (CAC) methods for PM2.5 approved for use in 
a SLAMS under proposed new provisions in Sec. 58.13(f) would not become 
de facto equivalent methods. This applies to methods that have not been 
designated equivalent and do not satisfy the requirement of Section 2.4 
described above. The new section would further clarify that the 
monitoring data obtained with CAC methods would be restricted to use 
for the purposes of Sec. 58.13(f) and would not be used for making 
comparisons to the NAAQS. Proposed new section 2.9 would define so-
called ``IMPROVE'' samplers for fine particulate matter and clarify 
that IMPROVE samplers, although not designated as equivalent methods, 
could be used in SLAMS for monitoring regional background 
concentrations of fine particulate matter.
    Finally, minor changes are proposed to section 2.7.1 to update the 
address to which requests for approval for the use of methods under the 
various provisions of Appendix C should be sent, and section 5 to add 
additional references.

O. Appendix D

    The revisions to Appendix D proposed today would revise Sections 1, 
2, 2.8, 3, 3.7, and 5 to incorporate changes made necessary by the 
proposed new PM2.5 NAAQS. Section 1 is revised to add criteria for 
core PM2.5 stations. Two additional SLAMS monitoring objectives 
are added: the first is to determine the extent of regional pollutant 
transport among populated areas, which may originate from distant 
pollutant sources; the second is in support of secondary NAAQS, to 
determine the welfare-related impacts in more rural and remote areas 
(such as visibility impairment and effects on vegetation). Section 2 is 
revised to include information that would be useful in designing 
regulatory networks. Section 2.8 and 3.7 are revised to apply to 
PM2.5 as well as PM10. Section 2.8.1 is added to discuss 
monitoring planning areas and SAZ's. Section 2.8.2 is added to address 
the PM2.5 monitoring sites and other requirements to be discussed 
in the State PM monitoring plan. Finally, section 2.8.3 is added to 
describe the selection of monitoring locations and SAZ's within the 
monitoring planning area. A series of diagrams are used to illustrate 
the basic principles.
    The PM2.5 NAMS shall be selected from the core PM2.5 
SLAMS. This network will focus on population-oriented surveillance and 
is intended to provide a national trends network to study the impact of 
PM2.5 emission sources including regional transport. A new Table 
5, which lists the goals for the number of PM2.5 NAMS by EPA 
Region, is added to Section 3.7. Table 5 in Section 5 is redesignated 
as Table 6 and revised to include PM2.5.
    In Section 2.8.1, in particular, MPA's and SAZ's are introduced to 
conform to the population-oriented, spatial averaging approach taken in 
the proposed new PM2.5 NAAQS under 40 CFR Part 50. This approach 
is more directly related to the epidemiological studies used as the 
basis for the proposed revisions to the particulate matter NAAQS. This 
proposal recognizes that the use of MPA's and SAZ's introduces greater 
complexity into the network design process and the assessment of 
violations of the NAAQS. Thus, the Administrator would specifically 
welcome comments on the

[[Page 65791]]

network design approach described in Section 2.8.1 through Section 
2.8.3.
    Previous requirements for number of monitors in this appendix have 
been related to the urbanized area populations. The boundaries for the 
urbanized populations to do not follow political or geographical 
boundaries. Hence, it is difficult at times to determine the component 
populations, emissions, or location of monitoring sites. A new concept 
is being introduced with this proposal to change from urbanized area 
population to MSA/PMSA populations for PM10 and PM2.5. This 
will make it easier to track monitors for the above reasons, and to 
more accurately relate measured concentrations to population exposures.
1. NAAQS Comparison Sites and New Site Codes
    Through its monitoring plan, which is reviewed and approved by the 
Regional Administrator, a State would select the population-oriented 
2 sites eligible for NAAQS comparisons which are included in each 
monitoring planning area and its SAZ's. Comparisons with the annual 
primary PM2.5 NAAQS would be based on population oriented SLAMS 
sites as well as other sites representative of area-wide concentrations 
in SAZ's. Comparisons to the 24-hour primary PM2.5 NAAQS would be 
based on these sites as well as all other sites which are population-
oriented. To encourage PM2.5 monitoring initially, for the first 3 
years after effective date of promulgation a moratorium is proposed on 
using data from all eligible SPM's to determine violations of the 
NAAQS. After this time, any operating SPM site which records a 
violation of the NAAQS would become eligible for NAAQS comparisons, 
should be included in the State monitoring plan, and should be 
considered during the State's review and development of their 
monitoring network.
---------------------------------------------------------------------------

    \2\ As currently used in Part 58, population-oriented monitoring 
or sites applies to residential areas, commercial areas, 
recreational areas, industrial areas where workers from more than 
one company are located, and other areas where a substantial number 
of people may spend a significant fraction of their day.
---------------------------------------------------------------------------

    Figure 1 in Appendix D shows a conceptual Venn diagram that 
illustrates which PM2.5 sites in a MPA would be eligible for 
comparison to the 24-hour and annual PM2.5 NAAQS. To be eligible 
for NAAQS comparisons, sites must meet all three of the following 
requirements: (1) Are NAMS/SLAMS or other population oriented sites, 
(2) are included in the monitoring plan, and (3) meet the requirements 
of 58.13 and Appendices A, C, and E. Sites that meet the additional 
requirement of generally representing areawide concentrations in the 
SAZ are also eligible for comparison to the annual PM2.5 NAAQS 
using the spatial averaging procedure specified in Part 50 Appendix K. 
Such sites are designated ``B''. All core monitoring sites and NAMS 
sites, which are a subset of the core sites, are B sites as are many 
other SLAMS and some non-SLAMS sites. Other population-oriented sites 
which are more representative of localized hot spots are only eligible 
for comparison on a site-by-site basis to the 24-hour PM2.5 NAAQS 
and are designated ``D''. These may include population-oriented 
industrial monitors which meet the applicable Part 58 requirements and 
are also included in the PM monitoring plan. The figure shows that all 
PM2.5 SLAMS sites are designated ``B'' or ``D''. Sites not 
designated as ``B'' or ``D'' sites would be designated as ``O'' sites. 
These codes would become new pollutant specific codes on the AIRS 
monitoring site file. In addition, core SLAMS PM2.5 sites will 
receive a new AIRS site type code. These data reporting changes will be 
described more fully in future AIRS guidance.
    A network design issue that relates to the spatial averaging form 
of the annual standard is the selection of the first (and/or only) site 
in a prospective SAZ. Because the intent of the spatial average form of 
the PM2.5 NAAQS is to estimate community, area-wide air pollution, 
the emphasis on the first selected SLAMS sites (including core SLAMS) 
would be ``typical population exposure.''
2. Monitoring Planning Areas and SAZ's
    In order to acquire population-oriented, spatially averaged 
monitoring data that correspond more closely to the data that are the 
basis for the proposed PM2.5 NAAQS, the concepts of monitoring 
planning areas and SAZ's are used in Section 2.8.1. As part of its 
monitoring plan, a State will propose monitoring planning areas and 
also propose non-overlapping SAZ's for each monitoring planning area. 
The number of monitoring planning areas is determined by the State. 
This may be one area to cover a small State like Rhode Island or be as 
many as 25 to correspond to existing air pollution control districts in 
a State like California. Information to be considered includes 
topography, PM emissions, number and type of significant PM sources as 
well as population density and distribution. Monitoring planning areas 
are required to include all metropolitan statistical areas (MSA's) and 
Primary Metropolitan Statistical areas (PMSA's) with population greater 
than 500,000, and generally recommended to include MSA's/PMSA's with 
population greater than 250,000 and high pollution (defined as 
producing measurements greater than or equal to 0.8 times the level of 
the PM2.5 NAAQS) as well as other areas determined to be likely to 
have high concentration of PM2.5. In addition, optional MPA's may 
include other designated parts of a State. An MPA should not include 
different areas separated by topographical barriers. Each MPA can have 
one or more SAZ's representing the area. The SAZ define the area within 
which all eligible monitoring data (from ``B'' sites) will be averaged 
for comparisons with the annual PM2.5 NAAQS. The MPA's and SAZ's 
would be reviewed and approved annually by the Regional Administrator. 
Until the monitoring plan is approved, EPA intends to have the SLAMS 
and sites eligible for NAAQS comparisons default to the SLAMS 
previously approved. Sites which have discontinued monitoring would 
continue to be used for comparisons to the NAAQS until their monitoring 
type status changes.
    Multiple zones within an MPA are most appropriate for large 
metropolitan areas, large geographical monitoring regions and areas in 
which concentrated source regions are in low population portions of an 
MPA. All MPA's and SAZ's must be defined on the basis of some existing 
delineated mapping data such as county boundaries, zip codes, census 
blocks or groups of census blocks. This will assist in the proper 
characterization of the spatial representativeness of air monitoring 
sites and facilitate better presentations of air monitoring data on 
national, regional, and local maps.
    All areas in the ambient air may become a SAZ based on 
considerations of population density, pollution concentration gradients 
and or the physical size of the area. Generally, a SAZ should 
characterize an area of relatively homogeneous air quality (i.e., the 
annual average concentration of the individual monitoring locations 
within the area should be within 20 percent of the spatial 
average) and be affected by the same major source categories of 
particulate matter. In MSA's, the SAZ's must completely cover the 
entire MPA. In other MPA's, the SAZ's might not completely cover the 
entire MPA. For example, small networks consisting of say one or two 
monitoring sites may not adequately characterize the air quality in a 
large geographic area or in large areas of relatively low population or 
pollution density. In another situation,

[[Page 65792]]

population centers and pollution regions represented by monitoring 
sites may be geographically disjoint. In these cases, the spatial 
representativeness of the monitoring site should be considered in 
defining the SAZ boundaries. Until more monitoring sites are 
established, the monitored air quality in areas outside of SAZ's is not 
known. Although ideally all areas of a State should be included in a 
SAZ, monitoring density may be insufficient to completely characterize 
a specific MPA and more monitors would be needed. Nonetheless, in some 
circumstances a SAZ can be represented by a single monitoring location 
and this may be sufficient to properly characterize an MPA. The SAZ's 
should generally include a minimum population of 250,000 and not more 
than 2 million. Deviations from this criteria should be based on the 
area's physical size and population density.
    The Administrator recognizes that the designation of SAZ's within 
Monitoring Planning Areas introduces a certain degree of complexity 
into the monitoring network planning and data usage process. Comments 
are therefore solicited on the use of a simpler approach to satisfy the 
requirements for spatial averaging which are proposed in Part 50. In 
particular, comments are solicited on a approach wherein there is only 
one SAZ in each MPA which has the same boundaries as the MPA.
3. Core Monitoring Sites
    To provide a minimal PM2.5 network in all high population 
areas for protection of the annual and 24-hour PM NAAQS, each required 
monitoring planning area must have at least two core monitors. The new 
core monitoring locations would be an important part of the basic PM-
fine SLAMS regulatory network. These sites are intended to primarily 
reflect community-wide air pollution, which would reflect monitoring 
locations in residential areas or where people spend a substantial part 
of the day take. In addition to the population-oriented monitoring 
sites, core monitors would also be established for background and 
transport monitoring. States should work cooperatively in establishing 
their State networks in order to maximize the value of monitoring data 
to best understand the regional behavior of PM2.5.
    To permit interface with measurements of ozone precursors which are 
also contributors to PM2.5, an additional core monitor collocated 
at a PAMS site is required in those MSA's where both PAMS and 
PM2.5 monitoring are required. The core monitor to be collocated 
at a PAMS site is considered part of the MPA PM2.5 SLAMS network 
and is not considered as a part of the PAMS network as described in 
Section 4 of Appendix D.
    The new core population-oriented PM-fine network is conceptually 
similar to the existing NAMS for other pollutants, but would allow for 
some year to year changes in site location to ensure that the typical 
areas of high pollution, high population areas are always monitored. 
Core sites will be the key sampling locations designated for initial 
monitoring, and a subset would be selected for longer-term monitoring. 
The latter would become the NAMS.
    The core sites will also produce the most complete data in the PM-
fine network. Daily sampling would be required, except during low 
pollution seasons or other periods as exempted by EPA. As such, a 
subset of these sites should be considered as candidate locations for 
adding state-of-the-art research monitoring devices whose data might 
need to be considered in future reviews of the PM NAAQS. This will 
ensure continuity and comparability of past, present and future PM data 
bases.
    Finally, because the core sites would produce the most data, many 
would be the most likely locations for determining violations of a 
short-term NAAQS. The core locations would become critical for judging 
future attainment in an area that has been determined to violate the 
NAAQS, again putting emphasis on areas with the largest population 
impact. Complete data at background and transport core sites will also 
provide the needed data base to better understand the source-receptor 
relationships and assist the implementation program.
    Each SAZ in a required MPA must have at least one core monitor; the 
SAZ's in optional MPA's should have at least one core monitor; and it 
is also suggested that SAZ's should have at least one core site for 
every four SLAMS. Exemptions are allowed for required core stations in 
MSA's with population greater than 500,000, if measured or modeled 
concentrations of PM2.5 are less than 80 percent of the NAAQS for 
PM2.5. Specific comments on the required and suggested number of 
core monitoring locations are requested.
4. Examples of MPA's, SAZ's and NAAQS Eligible Monitors
    Some examples may better illustrate how the concepts of monitoring 
planning areas and SAZ's may be realized in practice. The San Joaquin 
Valley air basin in California could be an MPA. If emission sources are 
distributed throughout this region, then the entire MPA could also be 
the SAZ. For large counties, such as California's San Bernardino 
County, which have non-uniform emission sources and population density, 
there could be at least two SAZ's, such as an eastern SAZ and a western 
SAZ which is part of the South Coast Air Basin. For an MSA, such as the 
Philadelphia MSA, or MSA/MPA which crosses State boundaries, separate 
SAZ's are suggested for each State portion, with substantial population 
(e.g. greater than 250,000). For the Philadelphia PA-NJ MSA, this could 
mean at least separate zones for the Philadelphia, PA and NJ portions. 
In this manner, each State would be responsible for the networks in its 
SAZ portion of the MPA. (Each of these SAZ's must have at least one 
core monitor for a total of two for the MPA). Furthermore, for MSA's 
and large geographic areas with concentrated source regions or 
industrial areas, such as Philadelphia, separate SAZ's are suggested 
for the residential/city center and the industrial area to better 
characterize the gradients in PM2.5 concentrations. Downtown 
street canyons may be appropriate SAZ's if they also include 
residential areas, such as is the case in mid-town Manhattan, NY or if 
they include commercial areas which have higher PM2.5 
concentrations within the MPA and where significant numbers of people 
work during the day. Comments are solicited on criteria for defining 
SAZ's.
    A series of figures is presented to illustrate the concept of MPA's 
and SAZ's. A hypothetical MPA representing an Eastern urban area is 
given in Figure 2 of appendix D and illustrates how monitors can be 
located in relation to population and areas of poor quality. Figure 3 
in Appendix D shows the same MPA as Figure 2, but includes three SAZ's: 
an industrial zone, a downtown central business district, and 
residential areas. Figure 4 in Appendix D shows the same MPA 
illustrated in Figures 2 and 3. However, sites are denoted by whether 
they are eligible for comparison with the 24-hour PM2.5 NAAQS or 
both the 24-hour and the annual PM2.5 NAAQS. Figure 5 in Appendix 
D shows potential SAZ's in a hypothetical Western State. Figure 6 in 
Appendix D illustrates State coverage by SAZ's both within and outside 
MPA's. More detailed guidance for network design for PM2.5 using 
the concepts of core monitoring stations, MPA's, and SAZ's will be 
available shortly in an EPA guidance document which is in preparation.

[[Page 65793]]

5. Substitute PM Samplers
    Appendix C (Section 2.2) to Part 58 describes conditions under 
which TSP samplers may be used as substitutes for PM10 samplers 
and when such TSP samplers must be replaced with PM10 samplers. 
The proposed rule will describe similar language regarding PM10 
samplers which may be used as substitutes for PM2.5 and provide 
clarification to ensure that only the appropriate TSP or PM10 
sites are required to be converted to PM10 and PM2.5, 
respectively. This provision is intended to be used when PM 
concentrations are low and substitute samplers can be used to satisfy 
the minimum number of PM samplers needed for an adequate PM network. 
This may be most appropriate when sufficient resources to purchase new 
PM samplers may not exist and existing samplers can be temporarily used 
to serve a new PM network.
6. NAMS Network Design
    In Section 3.7, the PM10 design criteria for NAMS, namely 
monitoring objectives, spatial representativeness, the category ``a'' 
maximum concentration site, number of sites, etc., remains in effect. 
In addition, the traditional concept of NAMS as long-term monitoring 
stations to assess trends and to support national assessments and 
decisions is reiterated. However, concerning PM2.5 network design, 
a more flexible approach is proposed. First, the PM2.5 NAMS will 
be concentrated in metropolitan areas in keeping with the risk 
management approach of the proposed new PM2.5 NAAQS. Next, a 
numeric range of prospective PM2.5 NAMS by EPA Region are 
identified. These are based on consideration of a number of factors set 
by Regions to provide maximum flexibility for State and local agencies, 
but should represent the range of conditions occurring in the Regions 
taking into consideration such factors as the total number and types of 
sources, ambient characteristics of particulate matter, regional 
transport, geographic area, and affected population. The goals for 
Regions varies from a low of 10 to 15 for Regions VII, VIII and X to a 
high of 35 to 50 for Regions IV and V while the total ranges from 205 
to 295 with an expected national target of 250. In particular, comments 
are requested about the general approach of goals by Region and the 
numbers estimated.

P. Appendix E

    Today's revision to Appendix E consists of relatively minor changes 
to Section 8 which currently provides the sampler siting criteria for 
PM10. The modifications basically expand the siting requirements 
to include PM2.5 as well as PM10 by selectively replacing the 
term PM10 with PM which would be defined as applying to PM10 
and PM2.5. This will permit existing PM10 sites to continue 
to be used and, when appropriate, to serve as platforms for new 
PM2.5 sampling.

Q. Appendix F

    A new section has been added for the annual summary statistics for 
PM2.5 in Appendix F. It should be noted that the current 
procedures for reporting and certifying the air quality data may be 
changed later, since the AIRS system is undergoing reengineering.

R. Cost Estimates for New PM Networks

    The costs associated with the start-up of a PM2.5 network and 
the phase-down of the existing PM10 sampling network depend on the 
3-year phase-in of the new proposed requirements and the number of PM 
monitors that the Administrator believes are necessary in a mature 
network.

                                          Table 1. PM-2.5 Network Costs                                         
                                             [Thousands of dollars]                                             
----------------------------------------------------------------------------------------------------------------
                                 Number of   Number of    Capital    Sampling     Filter     Special     Total  
              Year                 sites      samplers      cost       & QA      analysis    studies      cost  
------------------------------------------------\1\--------------------------------\2\--------------------------
1997...........................          0           0      $4,095  .........  ...........  .........     $4,095
1998...........................        216         318       7,908     $4,382      $1,558      $2,600     16,478
1999...........................        714       1,004       6,850     11,514         926       1,300     20,590
2000...........................      1,200       1,490   .........     17,833         926       1,300    20,059 
----------------------------------------------------------------------------------------------------------------
\1\ The PM-2.5 Network includes 160 collocated monitors for QA purposes, and 130 collocated monitors to avoid   
  weekend site visits.                                                                                          
\2\ Three different types of filter analyses are anticipated (exceedances analyses, screening analyses, and     
  detailed analyses).                                                                                           


                Table 2.--Cost for PM2.5 Filter Analyses                
------------------------------------------------------------------------
                                                               Estimated
                   Type of filter analysis                      cost per
                                                                 sample 
------------------------------------------------------------------------
Exceedance Analysis:                                                $200
    High PM2.5 concentration events are optically analyzed              
     for particle size and composition utilizing electron               
     microscopy..............................................           
Screening Analysis:                                                     
    X-Ray Fluorescence (XRF) for elemental composition                  
     (crustal material, sulfur, and heavy metals)............         50
    Thermo-optical analysis for elemental/organic/total                 
     carbon..................................................         50
                      Detailed Analysis:                                
    Inductively Coupled Argon Plasma (ICAP) Analysis for                
     elemental composition...................................        100
    Analysis for speciated organic composition...............        400
    Analysis for sulfate, aerosol acidity....................        100
------------------------------------------------------------------------

    Table 3 presents the change in PM10 network costs. The costs 
are shown for a current network of 1,650 sites and the phase down to a 
future projected network of 600 sites. PM10 costs have been 
calculated for the continued operation on a one in 6-day schedule, and 
for the relocation or discontinuance of monitoring sites. Table 4 shows 
the cost of PM monitoring according to sampling frequency and the type 
of PM monitor. Details of this information can be found in the 
``Information Collection Request'' for these proposed requirements.

[[Page 65794]]



                                          Table3.--PM-10 Network Costs                                          
                                             [Thousands of dollars]                                             
----------------------------------------------------------------------------------------------------------------
                                                                                Capital                         
                                                       Number of   Number of    cost to   Operation &    Total  
                         Year                            sites    samplers\1\    remove   maintenance     cost  
                                                                                 sites        cost              
----------------------------------------------------------------------------------------------------------------
1997.................................................      1,650       1,810   .........     $15,474     $15,473
1998.................................................      1,374       1,544        $110      12,181      12,291
1999.................................................        972       1,132         174       8,914       9,088
2000.................................................        600         760         161       5,966       6,127
----------------------------------------------------------------------------------------------------------------
\1\ The PM10 network includes 160 collocated monitors for QA purposes.                                          


               Table 4.--Costs for Particulate Monitoring               
------------------------------------------------------------------------
    PM monitor and sampling        One-time capital   Annual operation &
           frequency                     cost          maintenance cost 
------------------------------------------------------------------------
PM-10 1-in-6 day sampling        $14,500............  $8,700.           
 schedule.                                                              
PM-2.5 1-in-6 day sampling       $9,600 to $16,900..  $11,200.          
 schedule.                                                              
PM-2.5 every day sampling......  $14,600 to $21,900.  $18,900.          
Nephelometer (continuous)......  $20,100 to $26,300.  $16,700 to        
                                                       $17,500.         
------------------------------------------------------------------------

S. Reference

    1. Information Collection Request, 40 CFR 58 Ambient Air Quality 
Surveillance, OMB #2060-0084, EPA ICR #0940.14, U.S. Environmental 
Protection Agency, Office of Air Quality Planning and Standards, 
Research Triangle Park, NC 27711 (October 23, 1996).

V. Administrative Requirements

A. Regulatory Impact Analysis

    Under Executive Order 12866 (58 FR 51735, October 4, 1993), the 
Agency must determine whether the regulatory action is ``significant'' 
and therefore subject to Office of Management and Budget (OMB) review 
and to the requirements of the Executive Order. The Order defines 
``significant regulatory action'' as one that is likely to result in a 
rule that may:
    (1) Have an annual effect on the economy of $100 million or more or 
adversely affect in a material way the economy, a sector of the 
economy, productivity, competition, jobs, the environment, public 
health or safety, or State, local, or governments or communities;
    (2) Create a serious inconsistency or otherwise interfere with an 
action taken or planned by another Agency;
    (3) Materially alter the budgetary impact of entitlements, grants, 
user fees, or loan programs or the rights and obligations or recipients 
thereof; or
    (4) Raise novel legal or policy issues arising out of legal 
mandates, the President's priorities, or the principles set forth in 
the Executive Order.
    It has been determined that this rule is not a ``significant 
regulatory action'' under the terms of the Executive Order 12866 and is 
therefore not subject to formal OMB review. However, this rule is being 
reviewed by OMB under Reporting and Record keeping Requirements (see 
below).

B. Paperwork Reduction Act

    The information collection requirements contained in this proposed 
rule have been submitted for approval to OMB under the Paperwork 
Reduction Act, 44 U.S.C. 3501 et seq. An Information Collection Request 
document has been prepared by the EPA (ICR No. 0940.14) and a copy may 
be obtained from Sandy Farmer, Information Policy Branch, EPA, 401 M 
Street SW, Mail Code 2137, Washington, DC 20460; or by calling (202) 
260-2740.
1. Need and Use of the Collection
    The main use for the collection of the data is to support the PM 
NAAQS revisions. The various parameters reported as part of this ICR 
are necessary to ensure that the information and data collected by 
State and local agencies to assess the nation's air quality are 
defensible, of known quality, and meet the EPA's data quality goals of 
completeness, precision, and accuracy.
    The need and authority for this information collection is contained 
in Section 110(a)(2)(C) of the Act, which requires ambient air quality 
monitoring for purposes of the SIP and reporting of the data to EPA, 
and Section 319, which requires the reporting of a daily air pollution 
index. The legal authority for this requirement is the Ambient Air 
Quality Surveillance Regulations, 40 CFR 58.20, 58.21, 58.25, 58.26, 
58.28, 58.30, 58.31, 58.35, and 58.36.
    The EPA's Office of Air Quality Planning and Standards uses ambient 
air monitoring data for a wide variety of purposes, including making 
NAAQS attainment/nonattainment decisions; determining the effectiveness 
of air pollution control programs; evaluating the effects of air 
pollution levels on public health; tracking the progress of SIP's; 
providing dispersion modeling support; developing responsible, cost-
effective control strategies; reconciling emission inventories; and 
developing air quality trends. The collection of PM2.5 data is 
necessary to support the PM2.5 NAAQS, and the information 
collected will have practical utility as a data analysis tool.
    The State and local agencies with responsibility for reporting 
ambient air quality data and information as requested by these proposed 
regulations will submit these data electronically to the U.S. EPA's 
Aerometric Information Retrieval System, Air Quality Subsystem (AIRS-
AQS). Quality assurance/quality control records and monitoring network 
documentation are also maintained by each State/local agency, in AIRS-
AQS electronic format where possible.
2. Reporting and Recordkeeping Burden
    The total annual collection and reporting burden associated with 
this proposal is estimated to be 490,526 hours. Of this total, 484,545 
hours are estimated to be for data reporting, or an average of 3,327 
hours for the estimated 130 respondents. The remainder of 5,981 hours 
for recordkeeping burden averages 46 hours for the estimated 130 
respondents. The capital O/M costs associated with this proposal are 
estimated to be $19,714,453. These estimates include time for reviewing 
instructions, searching existing data sources, gathering and 
maintaining the data needed, and completing and reviewing the 
collection of information.
    The frequency of data reporting for the NAMS and the SLAMS air 
quality data as well as the associated precision and accuracy data are 
submitted to EPA according to the schedule defined in 40 CFR part 58. 
This regulation currently requires that State and local air quality

[[Page 65795]]

management agencies report their data within 90 days after the end of 
the quarter during which the data were collected. The annual SLAMS 
report is submitted by July 1 of each year for data collected from 
January 1 through December 31 of the previous year in accordance with 
40 CFR 58.26. This certification also implies that all SPM data to be 
used for regulatory purposes by the affected State or local air quality 
management agency have been submitted by July 1.
3. Burden
    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 purpose of collecting, validating, and 
verifying 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 are listed in 40 CFR Part 9 and 48 CFR Chapter 15.
    Comments are requested on the Agency's need for this information, 
the accuracy of the provided burden estimates, and any suggested 
methods for minimizing respondent burden, including through the use of 
automated collection techniques. Send comments on the ICR to the 
Director, OPPE Regulatory Information Division; U.S. Environmental 
Protection Agency (2137); 401 M St., SW.; Washington, DC 20460; and to 
the Office of Information and Regulatory Affairs, Office of Management 
and Budget, 725 17th St., NW., Washington, DC 20503, marked 
``Attention: Desk Officer for EPA.'' Include the ICR number in any 
correspondence. Since OMB is required to make a decision concerning the 
ICR between 30 and 60 days after December 13, 1996, a comment to OMB is 
best assured of having its full effect if OMB receives it by January 
13, 1997. The final rule will respond to any OMB or public comments on 
the information collection requirements contained in this proposal.

C. Impact on Small Entities

    Pursuant to section 605(b) of the Regulatory Flexibility Act, 5 
U.S.C. 605(b), the Administrator certifies that this rule will not have 
a significant economic impact on a substantial number of small 
entities. This rulemaking package does not impose any additional 
requirements on small entities because it applies to governments whose 
jurisdictions cover more than 200,000 population. Under the Regulatory 
Flexibility Act, governments are small entities only if they have 
jurisdictions of less than 50,000 people. In addition, this rule 
imposes no enforceable duties on small businesses.

D. Unfunded Mandates Reform Act of 1995

    Under sections 202, 203 and 205 of the Unfunded Mandates Reform Act 
of 1995 (``Unfunded Mandates Act''), signed into law on March 22, 1995, 
the EPA must undertake various actions in association with proposed or 
final rules that include a Federal mandate that may result in estimated 
costs of $100 million or more to the private sector, or to State or 
local governments in the aggregate.
    The EPA has determined that this rule does not contain a Federal 
mandate that may result in expenditures of $100 million or more for 
State, and local governments, in the aggregate, or the private sector 
in any one year. Our economic analysis indicates that the total 
implementation cost will be approximately $88,728,000 in 1996 dollars 
for the 3 years to phase in the network, or an average of $29,576,000 
for the 3-year implementation. The table below shows how this 3-year 
average was derived for the various cost elements of monitoring. While 
this table represents the 3-year period 1998-2000, the total cost for 
PM2.5 monitoring include the initial capital costs anticipated in 
1997. In addition, this rule imposes no enforceable duties on small 
businesses.

                      Cost Based on 3-Year Average                      
                         [Thousands of dollars]                         
------------------------------------------------------------------------
                                                                 3 year 
              Cost/Element                  PM10      PM2.5      totals 
------------------------------------------------------------------------
Network design.........................         $0       $571       $571
Site installation......................        311      5,013      5,324
Sampling & analysis....................      2,647      6,758      9,405
Maintenance............................      1,233      1,928      3,161
Data management........................      1,245      1,574      2,819
Quality assurance......................      1,745      3,373      5,118
Supervision............................      1,988      1,189      3,177
                                        --------------------------------
    Summary \1\........................      9,169     20,407    29,576 
------------------------------------------------------------------------
\1\ Totals are rounded.                                                 

List of Subjects

40 CFR Part 53

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

40 CFR Part 58

    Air pollution control, Intergovernmental relations, Reporting and 
recordkeeping requirements.

    Dated: November 27, 1996.
Carol M. Browner,
Administrator.

    For the reasons set forth in the preamble, title 40, chapter I, 
part 53 and part 58 of the Code of Federal Regulations are proposed to 
be amended as follows:

[[Page 65796]]

PART 53--[AMENDED]

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

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

    2. Subpart A is revised to read as follows:

Subpart A--General Provisions

Sec.
53.1 Definitions.
53.2 General requirements for a reference method determination.
53.3 General requirements for an equivalent method determination.
53.4 Applications for reference or equivalent method determinations.
53.5 Processing of applications.
53.6 Right to witness conduct of tests.
53.7 Testing of methods at the initiative of the Administrator.
53.8 Designation of reference and equivalent methods.
53.9 Conditions of designation.
53.10 Appeal from rejection of application.
53.11 Cancellation of reference or equivalent method designation.
53.12 Request for hearing on cancellation.
53.13 Hearings.
53.14 Modification of a reference or equivalent method.
53.15 Trade secrets and confidential or privileged information.
53.16 Supersession of reference methods.

Tables to Subpart A of Part 53

Table A-1--Summary of Applicable Requirements for Reference & 
Equivalent Methods for Air Monitoring of Criteria Pollutants

Appendix A to Subpart A of Part 53--References

Subpart A--General Provisions


Sec. 53.1  Definitions.

    (a) Terms used but not defined in this part shall have the meaning 
given them by the Act.
    (b) Act means the Clean Air Act (42 U.S.C. 1857-1857l), as amended.
    (c) Agency means the Environmental Protection Agency.
    (d) Administrator means the Administrator of the Environmental 
Protection Agency or the Administrator's authorized representative.
    (e) Reference method means a method of sampling and analyzing the 
ambient air for an air pollutant that is specified as a reference 
method in an appendix to part 50 of this chapter, or a method that has 
been designated as a reference method in accordance with this part; it 
does not include a method for which a reference method designation has 
been canceled in accordance with Sec. 53.11 or Sec. 53.16.
    (f) Equivalent method means a method of sampling and analyzing the 
ambient air for an air pollutant that has been designated as an 
equivalent method in accordance with this part; it does not include a 
method for which an equivalent method designation has been canceled in 
accordance with Sec. 53.11 or Sec. 53.16.
    (g) Candidate method means a method of sampling and analyzing the 
ambient air for an air pollutant for which an application for a 
reference method determination or an equivalent method determination is 
submitted in accordance with Sec. 53.4, or a method tested at the 
initiative of the Administrator in accordance with Sec. 53.7.
    (h) Manual method means a method for measuring concentrations of an 
ambient air pollutant in which sample collection, analysis, or 
measurement, or some combination thereof, is performed manually. A 
method for PM10 or PM2.5 which utilizes a sampler that 
requires manual preparation, loading, and weighing of filter samples is 
considered a manual method even though the sampler may be capable of 
automatically collecting a series of sequential samples.
    (i) Automated method or analyzer means a method for measuring 
concentrations of an ambient air pollutant in which sample collection 
(if necessary), analysis, and measurement are performed automatically 
by an instrument.
    (j) Test analyzer means an analyzer subjected to testing as part of 
a candidate method in accordance with subparts B, C, D, E, or F of this 
part, as applicable.
    (k) Applicant means a person or entity who submits an application 
for a reference or equivalent method determination under Sec. 53.4, or 
a person or entity who assumes the rights and obligations of an 
applicant under Sec. 53.7. Applicant may include a manufacturer, 
distributer, supplier, or vendor.
    (l) Ultimate purchaser means the first person who purchases a 
reference method or an equivalent method for purposes other than 
resale.
    (m) PM10 sampler or PM2.5 sampler means a device, 
associated with a manual method for measuring PM10 or PM2.5 
(respectively), designed to collect PM10 or PM2.5 
(respectively) from an ambient air sample, but lacking the ability to 
automatically analyze or measure the collected sample to determine the 
mass concentration of PM10 or PM2.5 in the sampled air.
    (n) Test sampler means a PM10 sampler or a PM2.5 sampler 
subjected to testing as part of a candidate method in accordance with 
subparts C, D, E or F of this part.
    (o) Collocated describes two or more air samplers, analyzers, or 
other instruments which sample the ambient air that are operated 
simultaneously while located side by side, separated by a distance that 
is large enough to preclude the air sampled by any of the devices from 
being affected by any of the other devices, but small enough so that 
all devices obtain identical or uniform ambient air samples that are 
equally representative of the general area in which the group of 
devices is located.
    (p) Sequential samples for particulate matter samplers means two or 
more particulate matter samples for sequential (but not necessarily 
contiguous) time periods that are collected automatically by the same 
sampler without the need for intervening operator service.
    (q) Class I equivalent method means an equivalent method for 
PM2.5 which is based on a sampler that is very similar to the 
sampler specified for reference methods in Appendix L of part 50 of 
this chapter, with only minor deviations or modifications, as 
determined by the EPA. A common example of a Class I PM2.5 sampler 
is a reference method sampler that has been modified to provide 
automatic collection of sequential samples, as defined in paragraph (p) 
of this section.
    (r) Class II equivalent method means an equivalent method for 
PM2.5 that utilizes a PM2.5 sampler in which an integrated 
PM2.5 sample is obtained from the atmosphere by filtration and 
subjected to a subsequent filter equilibration process followed by a 
gravimetric mass determination, but which is not a Class I equivalent 
method because of substantial deviations from the design specifications 
of the sampler specified for reference methods in Appendix L of part 50 
of this chapter, as determined by the EPA.
    (s) Class III equivalent method means an equivalent method for 
PM2.5 that has been determined by the EPA not to be a Class I or 
Class II equivalent method. This fourth type of PM2.5 method 
includes alternative equivalent method samplers and continuous 
analyzers, based on designs and measurement principles different from 
those specified for reference methods (e.g., a means for estimating 
aerosol mass concentration other than by conventional integrated 
filtration followed by equilibration and gravimetric analysis). These 
samplers (or monitors) are those deemed to be substantially different 
from reference method samplers and may use components and methods other 
than

[[Page 65797]]

those specified for reference method samplers. Class III candidate 
samplers or analyzers require full equivalency testing and must meet 
all requirements specified in subpart F of this chapter.
    (t) An ISO-registered facility shall be defined as a manufacturing 
facility that is either:
    (1) An International Organization for Standardization (ISO) 9001-
registered manufacturing facility, with registration maintained 
continuously; or
    (2) A facility that can be demonstrated, on the basis of 
information submitted to the EPA, to be operated according to an EPA-
approved and periodically audited quality system which meets, to the 
extent appropriate, the same general requirements as an ISO registered 
facility for the design and manufacture of designated reference and 
equivalent method samplers and monitors.
    (u) An ISO-certified auditor shall be defined as an auditor either 
certified by an ISO accredited registrar or an auditor who, based on 
information submitted to the EPA, meets the same general requirements 
as provided for ISO-certified auditors.


Sec. 53.2  General requirements for a reference method determination.

    The following general requirements for a reference method 
determination are summarized in Table A-1 of this subpart.
    (a) Manual methods. (1) For measuring SO2 and lead, Appendices 
A and G of part 50 of this chapter specify unique manual reference 
methods for those pollutants. Except as provided in Sec. 53.16, other 
manual methods for SO2 and lead will not be considered for 
reference method determinations under this part.
    (2) A reference method for measuring PM10 must be a manual 
method that meets all requirements specified in Appendix J of part 50 
of this chapter and must include a PM10 sampler that has been 
shown in accordance with this part to meet all requirements specified 
in subpart D of this part.
    (3) A reference method for measuring PM2.5 must be a manual 
method that meets the requirements specified in Appendix L of part 50 
of this chapter and must include a PM2.5 sampler that has been 
shown in accordance with this part to meet the applicable requirements 
specified in subpart E of this part. Further, reference method samplers 
must be manufactured in an ISO 9001-registered facility as defined in 
Sec. 53.1(t) and , as set forth in Sec. 53.51 (subpart E, of this 
part), and the Product Manufacturing Checklist set forth in subpart E 
of this part must be completed by an ISO 9001-certified auditor, as 
defined in Sec. 53.1(u), and submitted to the EPA annually to retain a 
PM2.5 reference method designation. In addition, all designated 
reference methods for PM2.5 must meet requirements for network 
operating performance determined annually as set forth in section 6 of 
Appendix A of part 58 of this chapter.
    (b) ``Automated methods.'' An automated reference method for 
measuring CO, O3, and NO2 must utilize the measurement 
principle and calibration procedure specified in the appropriate 
appendix to part 50 of this chapter and must have been shown in 
accordance with this part to meet the requirements specified in subpart 
B of this part.


Sec. 53.3  General requirements for an equivalent method determination.

    (a) Manual methods. A manual equivalent method must have been shown 
in accordance with this part to satisfy the applicable requirements 
specified in subpart C of this part. In addition, PM10 or 
PM2.5 samplers associated with manual equivalent methods for 
PM10 or PM2.5 must have been shown in accordance with this 
part to satisfy the following additional requirements:
    (1) A PM10 sampler associated with a manual method for 
PM10 must satisfy the requirements of subpart D of this part.
    (2) A PM2.5 Class I equivalent method sampler must satisfy all 
requirements of subparts C and E of this part, which include 
appropriate demonstration that each and every deviation or modification 
from the reference method sampler specifications does not significantly 
alter the performance of the sampler.
    (3) A PM2.5 Class II equivalent method sampler must satisfy 
the requirements of subparts C, E, and F of this chapter.
    (4) Requirements for PM2.5 Class III equivalent method 
samplers are not provided in this part because of the wide range of no-
filter-based measurement technologies that could be applied and the 
likelihood that these requirements will have to be specifically adapted 
for each such type of technology. Specific requirements will be 
developed as needed.
    (5) All designated equivalent methods for PM2.5 must be 
manufactured in an ISO 9001-registered facility, as defined in 
Sec. 53.1(t) and as set forth in Sec. 53.51 (subpart E) of this part, 
and the Product Manufacturing Checklist set forth in Appendix E of this 
part must be completed by an ISO 9001-certified auditor, as defined in 
Sec. 53.1(u), and submitted to the EPA annually to retain a PM2.5 
equivalent method designation.
    (6) All designated equivalent methods for PM2.5 must also meet 
annual requirements for network operating performance determined as set 
forth in section 6 of Appendix A of part 58 of this chapter.
    (b) Automated methods. (1) Automated equivalent methods for 
pollutants other than PM2.5 or PM10 must have been shown in 
accordance with this part to satisfy the requirements specified in 
subparts B and C of this part.
    (2) Automated equivalent methods for PM10 must have been shown 
in accordance with this part to satisfy the requirements of subparts C 
and D of this part.
    (3) Requirements for PM2.5 Class III automated equivalent 
methods for PM2.5 are not provided in this part because of the 
wide range of non-filter-based measurement technologies that could be 
applied and the likelihood that these requirements will have to be 
specifically adapted for each such type of technology. Specific 
requirements will be developed as needed.
    (4) All designated equivalent methods for PM2.5 must be 
manufactured in an ISO 9001-registered facility, as set forth in 
Appendix E of this part, and the Product Manufacturing Checklist set 
forth in Appendix E of this part must be completed by an ISO 9001-
certified auditor and submitted to the EPA annually to retain a 
PM2.5 equivalent method designation.
    (5) All designated equivalent methods for PM2.5 must also meet 
annual requirements for network operating performance determined as set 
forth in section 6 of Appendix A of part 58 of this chapter.


Sec. 53.4  Applications for reference or equivalent method 
determinations.

    (a) Applications for reference or equivalent method determinations 
shall be submitted in duplicate to: Director, National Exposure 
Research Laboratory, Department E (MD-77B), U.S. Environmental 
Protection Agency, Research Triangle Park, North Carolina 27711.
    (b) Each application shall be signed by an authorized 
representative of the applicant, shall be marked in accordance with 
Sec. 53.15 (if applicable), and shall contain the following:
    (1) A clear identification of the candidate method, which will 
distinguish it from all other methods such that the method may be 
referred to unambiguously. This identification must consist of a unique 
series of descriptors such as title, identification

[[Page 65798]]

number, analyte, measurement principle, manufacturer, brand, model, 
etc., as necessary to distinguish the method from all other methods or 
method variations, both within and outside the applicant's 
organization.
    (2) A detailed description of the candidate method, including but 
not limited to the following: The measurement principle, manufacturer, 
name, model number and other forms of identification, a list of the 
significant components, schematic diagrams, design drawings, and a 
detailed description of the apparatus and measurement procedures. 
Drawings and descriptions pertaining to candidate methods or samplers 
for PM2.5 must meet all applicable requirements in Reference 1 of 
Appendix A to this subpart, using appropriate graphical, nomenclature, 
and mathematical conventions such as those specified in References 3 
and 4 of Appendix A to this subpart.
    (3) A copy of a comprehensive operation or instruction manual 
providing a complete and detailed description of the operational and 
calibration procedures prescribed for field use of the candidate method 
and all instruments utilized as part of that method (see Sec. 53.9a).
    (i) As a minimum this manual shall include:
    (A) Description of the method and associated instruments;
    (B) Explanation of all indicators, information displays, and 
controls;
    (C) Complete setup and installation instructions, including any 
additional materials or supplies required;
    (D) Details of all initial or startup checks or acceptance tests 
and any auxiliary equipment required;
    (E) Complete operational instructions;
    (F) Calibration procedures and required calibration equipment and 
standards;
    (G) Instructions for verification of correct or proper operation;
    (H) Trouble-shooting guidance and suggested corrective actions for 
abnormal operation;
    (I) Required or recommended routine, periodic, and preventative 
maintenance and maintenance schedules,
    (J) Any calculations required to derive final concentration 
measurements; and
    (K) Appropriate references to 40 CFR part 50, Appendix L, Reference 
6, and any other pertinent guidelines.
    (ii) The manual shall also include adequate warning of potential 
safety hazards that may result from normal use and/or malfunction of 
the method and a description of necessary safety precautions. [See 
Sec. 53.9(b)] However, the previous requirement shall not be 
interpreted to constitute or imply any warranty of safety of the method 
by the EPA. For samplers and automated methods, the manual shall 
include a clear description of all procedures pertaining to 
installation, operation, preventative maintenance, and troubleshooting 
and shall also include parts identification diagrams. The manual may be 
used to satisfy the requirements of paragraphs (b) (1) and (2) of this 
section to the extent that it includes information necessary to meet 
those requirements.
    (4) A statement that the candidate method has been tested in 
accordance with the procedures described in subparts B, C, D, E, and/or 
F of this part, as applicable.
    (5) Test data, records, calculations, and test results as specified 
in subparts B, C, D, E, and/or F of this part, as applicable. Data must 
be sufficiently detailed to meet appropriate principles described in 
paragraphs 4 through 6 of Reference 2, Part b, sections 3.3.1 
(paragraph 1) and 3.5.1 (paragraphs 2 and 3) and in paragraphs 1 
through 3 of Reference 5 (section 4.8, Records) of appendix A of this 
subpart. Salient requirements from these references include the 
following:
    (i) The applicant shall maintain and include records of all 
relevant measuring equipment, including the make, type, and serial 
number or other identification, and most recent calibration with 
identification of the measurement standard or standards used and their 
NIST traceability. These records shall demonstrate the measurement 
capability of each item of measuring equipment used for the application 
and include a description and justification (if needed) of the 
measurement setup or configuration in which it was used for the tests. 
The calibration results shall be recorded and identified in sufficient 
detail so that the traceability of all measurements can be determined 
and any measurement could be reproduced under conditions close to the 
original conditions, if necessary, to resolve any anomalies.
    (ii) Test data shall be collected according to the standards of 
good practice and by qualified personnel. Test anomalies or 
irregularities shall be documented and explained or justified. The 
impact and significance of the deviation on test results and 
conclusions shall be determined. Data collected shall correspond 
directly to the specified test requirement and be labeled and 
identified clearly so that results can be verified and evaluated 
against the test requirement. Calculations or data manipulations must 
be explained in detail so that they can be verified.
    (6) A statement that the method, analyzer, or sampler tested in 
accordance with this part is representative of the candidate method 
described in the application.
    (c) For candidate automated methods and candidate manual methods 
for PM10 and PM2.5, the application shall also contain the 
following:
    (1) A detailed description of the quality system that will be 
utilized, if the candidate method is designated as a reference or 
equivalent method, to ensure that all analyzers or samplers offered for 
sale under that designation will have essentially the same performance 
characteristics as the analyzer(s) or samplers tested in accordance 
with this part. In addition, the quality system requirements for 
candidate methods for PM2.5 must be described in sufficient 
detail, based on the elements described in section 4 of Reference 1 
(Quality System Requirements) of appendix A of this subpart. Further 
clarification is provided in the following sections of Reference 2: 
Part A (Management Systems), sections 2.2 (Quality System and 
Description), 2.3 (Personnel Qualification and Training), 2.4 
(Procurement of Items and Services), 2.5 (Documents and Records), and 
2.7 (Planning); Part B (Collection and Evaluation of Environmental 
Data), sections 3.1 (Planning and Scoping), 3.2 (Design of Data 
Collection Operations), and 3.5 (Assessment and Verification of Data 
Usability); and Part C (Operation of Environmental Technology), 
sections 4.1 (Planning), 4.2 (Design of Systems), and 4.4 (Operation of 
Systems) of appendix A of this subpart .
    (2) A description of the durability characteristics of such 
analyzers or samplers [see Sec. 53.9(c)]. For methods for PM2.5, 
the warranty program must ensure that the required specifications (see 
Table A-1 of this subpart) will be met throughout the warranty period 
and that the applicant accepts responsibility and liability for 
ensuring this conformance, or resolving any nonconformities, including 
all necessary components of the system, regardless of the original 
manufacturer. The warranty program must be described in sufficient 
detail to meet appropriate provisions of the ANSI/ASQC and ISO 9001 
standards (References 1 and 2 in appendix A of this subpart) for 
controlling conformance and resolving nonconformance, particularly 
sections 4.12, 4.13, and 4.14 of Reference 1 in appendix A of this 
subpart.

[[Page 65799]]

    (i) Section 4.12 in appendix A of this subpart requires the 
manufacturer to establish and maintain a system of procedures for 
identifying and maintaining the identification of inspection and test 
status throughout all phases of manufacturing to ensure that only 
instruments that have passed the required inspections and tests are 
released for sale.
    (ii) Section 4.13 in appendix A of this subpart requires documented 
procedures for control of nonconforming product, including review and 
acceptable alternatives for disposition; section 4.14 requires 
documented procedures for implementing corrective (4.14.2) and 
preventive (4.14.3) action to eliminate the causes of actual or 
potential nonconformities. In particular, section 4.14.3 requires that 
potential causes of nonconformities be eliminated by using information 
such as service reports and customer complaints to eliminate potential 
causes of nonconformities.
    (d) For candidate reference or equivalent methods for PM2.5, 
the applicant shall provide to EPA for test purposes one sampler or 
analyzer that is representative of the sampler or analyzer associated 
with the candidate method. The sampler or analyzer shall be shipped FOB 
destination to Department E, (MD-77B), U.S. EPA, 79 T.W. Alexander 
Drive, Research Triangle Park, NC 27709, scheduled to arrive concurrent 
with or within 30 days of the arrival of the other application 
materials. This analyzer or sampler may be subjected to various tests 
that the EPA determines to be necessary or appropriate under 
Sec. 53.5(e), and such tests may include special tests not otherwise 
described in this part. If the instrument submitted under this 
paragraph malfunctions, becomes inoperative, or fails to perform as 
represented in the application before the necessary EPA testing is 
completed, the applicant shall be afforded an opportunity to repair or 
replace the device at no cost to the EPA. Upon completion of the EPA 
testing, the analyzer or sampler submitted under this paragraph shall 
be repacked by the EPA for return shipment to the applicant, using the 
same packing materials used for shipping the instrument to the EPA 
unless alternative packing is provided by the applicant. Arrangements 
for, and the cost of, return shipment shall be the responsibility of 
the applicant. The EPA does not warrant or assume any liability for the 
condition of the analyzer or sampler upon return to the applicant.


Sec. 53.5  Processing of applications.

    After receiving an application for a reference or equivalent method 
determination, the Administrator will publish notice of the application 
in the Federal Register and, within 120 calendar days after receipt of 
the application, take one or more of the following actions:
    (a) Send notice to the applicant, in accordance with Sec. 53.8, 
that the candidate method has been determined to be a reference or 
equivalent method;
    (b) Send notice to the applicant that the application has been 
rejected, including a statement of reasons for rejection;
    (c) Send notice to the applicant that additional information must 
be submitted before a determination can be made and specify the 
additional information that is needed (in such cases, the 120-day 
period shall commence upon receipt of the additional information);
    (d) Send notice to the applicant that additional test data must be 
submitted and specify what tests are necessary and how they shall be 
interpreted (in such cases, the 120-day period shall commence upon 
receipt of the additional test data);
    (e) Send notice to the applicant that the application has been 
found to be substantially deficient or incomplete and cannot be 
processed until additional information is submitted to complete the 
application and specify the general areas of substantial deficiency; or
    (f) Send notice to the applicant that additional tests will be 
conducted by the Administrator, specifying the nature of and reasons 
for the additional tests and the estimated time required (in such 
cases, the 120-day period shall commence one calendar day after the 
additional tests have been completed).


Sec. 53.6  Right to witness conduct of tests.

    (a) Submission of an application for a reference or equivalent 
method determination shall constitute consent for the Administrator or 
the Administrator's authorized representative, upon presentation of 
appropriate credentials, to witness or observe any tests required by 
this part in connection with the application or in connection with any 
modification or intended modification of the method by the applicant.
    (b) The applicant shall have the right to witness or observe any 
test conducted by the Administrator in connection with the application 
or in connection with any modification or intended modification of the 
method by the applicant.
    (c) Any tests by either party that are to be witnessed or observed 
by the other party shall be conducted at a time and place mutually 
agreeable to both parties.


Sec. 53.7  Testing of methods at the initiative of the Administrator.

    (a) In the absence of an application for a reference or equivalent 
method determination, the Administrator may conduct the tests required 
by this part for such a determination, may compile such other 
information as may be necessary in the judgment of the Administrator to 
make such a determination, and on the basis of the tests and 
information may determine that a method satisfies applicable 
requirements of this part.
    (b) In the absence of an application requesting the Administrator 
to consider revising an appendix to part 50 of this chapter in 
accordance with Sec. 53.16, the Administrator may conduct such tests 
and compile such information as may be necessary in the Administrator's 
judgment to make a determination under Sec. 53.16(d) and on the basis 
of the tests and information make such a determination.
    (c) If a method tested in accordance with this section is 
designated as a reference or equivalent method in accordance with 
Sec. 53.8 or is specified or designated as a reference method in 
accordance with Sec. 53.16, any person or entity who offers the method 
for sale as a reference or equivalent method thereafter shall assume 
the rights and obligations of an applicant for purposes of this part, 
with the exception of those pertaining to submission and processing of 
applications.


Sec. 53.8  Designation of reference and equivalent methods.

    (a) A candidate method determined by the Administrator to satisfy 
the applicable requirements of this part shall be designated as a 
reference method or equivalent method (as applicable), and a notice of 
the designation shall be submitted for publication in the Federal 
Register not later than 15 days after the determination is made.
    (b) A notice indicating that the method has been determined to be a 
reference method or an equivalent method shall be sent to the 
applicant. This notice shall constitute proof of the determination 
until a notice of designation is published in accordance with paragraph 
(a) of this section.
    (c) The Administrator will maintain a current list of methods 
designated as reference or equivalent methods in accordance with this 
part and will send a copy of the list to any person or group

[[Page 65800]]

upon request. A copy of the list will be available for inspection or 
copying at EPA Regional Offices.


Sec. 53.9  Conditions of designation.

    Designation of a candidate method as a reference method or 
equivalent method shall be conditioned on the applicant's compliance 
with the following requirements. Failure to comply with any of the 
requirements shall constitute a ground for cancellation of the 
designation in accordance with Sec. 53.11.
    (a) Any method offered for sale as a reference or equivalent method 
shall be accompanied by a copy of the manual referred to in 
Sec. 53.4(b)(3) when delivered to any ultimate purchaser.
    (b) Any method offered for sale as a reference or equivalent method 
shall generate no unreasonable hazard to operators or to the 
environment during normal use or when malfunctioning.
    (c) Any analyzer, PM10 sampler, or PM2.5 sampler offered 
for sale as a reference or equivalent method shall function within the 
limits of the performance specifications referred to in Sec. 53.20(a), 
Sec. 53.40(a), Sec. 53.50(a), or Sec. 53.60(a), as applicable, for at 
least 1 year after delivery and acceptance when maintained and operated 
in accordance with the manual referred to in Sec. 53.4(b)(3).
    (d) Any analyzer, PM10 sampler or PM2.5 sampler offered 
for sale as a reference or equivalent method shall bear a prominent, 
permanently affixed label or sticker indicating that the analyzer or 
sampler has been designated by EPA as a reference method or as an 
equivalent method (as applicable) in accordance with this part and 
displaying any designated method identification number that may be 
assigned by the EPA.
    (e) If an analyzer is offered for sale as a reference or equivalent 
method and has one or more selectable ranges, the label or sticker 
required by paragraph (d) of this section shall be placed in close 
proximity to the range selector and shall indicate clearly which range 
or ranges have been designated as parts of the reference or equivalent 
method.
    (f) An applicant who offers analyzers, PM10 samplers, or 
PM2.5 samplers for sale as reference or equivalent methods shall 
maintain an accurate and current list of the names and mailing 
addresses of all ultimate purchasers of such analyzers or samplers. For 
a period of 7 years after publication of the reference or equivalent 
method designation applicable to such an analyzer or sampler, the 
applicant shall notify all ultimate purchasers of the analyzer or 
PM2.5 or PM10 sampler within 30 days if the designation has 
been canceled in accordance with Sec. 53.11 or Sec. 53.16 or if 
adjustment of the analyzer or sampler is necessary under Sec. 53.11(b).
    (g) If an applicant modifies an analyzer, PM10 sampler, or 
PM2.5 sampler that has been designated as a reference or 
equivalent method, the applicant shall not sell the modified analyzer 
or sampler as a reference or equivalent method nor attach a label or 
sticker to the modified analyzer or sampler under paragraph (d) or (e) 
of this section until the applicant has received notice under 
Sec. 53.14(c) that the existing designation or a new designation will 
apply to the modified analyzer, PM10 sampler, or PM2.5 
sampler or has applied for and received notice under Sec. 53.8(b) of a 
new reference or equivalent method determination for the modified 
analyzer or sampler.
    (h) An applicant who has offered PM2.5 samplers or analyzers 
for sale as part of a reference or equivalent method may continue to do 
so only so long as the reference or equivalent method meets the annual 
requirements for network operating performance determined as set forth 
in section 6 of Appendix A of part 58 of this chapter. In the event 
that the annual network operating performance does not meet those 
requirements, the EPA shall, within 90 days after the end of the 
calendar year, notify the applicant of the unacceptable network 
performance assessment and issue a preliminary finding and notification 
of possible cancellation of the reference or equivalent method 
designation under Sec. 53.11. (Net performance is generally assessed 
for each calendar year, although when the number of samples for a 
specific method is not great enough to determine precision with 
adequate confidence, more than 1 calendar year of data may be 
combined.)
    (i) An applicant who has offered PM2.5 samplers or analyzers 
for sale as part of a reference or equivalent method may continue to do 
so only so long as the facility in which the samplers or analyzers are 
manufactured continues to be an ISO-registered facility, as set forth 
in subpart E of this part. In the event that the ISO registration for 
the facility is withdrawn, suspended, or otherwise becomes 
inapplicable, either permanently or for some specified time interval, 
such that the facility is no longer an ISO-registered facility, the 
applicant shall notify EPA within 30 days of the date the facility 
becomes other than an ISO-registered facility, and upon such 
notification, the EPA shall issue a preliminary finding and 
notification of possible cancellation of the reference or equivalent 
method designation under Sec. 53.11.
    (j) An applicant who has offered PM2.5 samplers or analyzers 
for sale as part of a reference or equivalent method may continue to do 
so only so long as updates of the Product Manufacturing Checklist set 
forth in subpart E of this part are submitted annually. In the event 
that an annual Checklist update is not received by the EPA within 12 
months of the date of the last such submitted Checklist or Checklist 
update, the EPA shall notify the applicant within 30 days that the 
Checklist update has not been received and shall, within 30 days from 
the issuance of such notification, issue a preliminary finding and 
notification of possible cancellation of the reference or equivalent 
method designation under Sec. 53.11.


Sec. 53.10  Appeal from rejection of application.

    Any applicant whose application for a reference or equivalent 
method determination has been rejected may appeal the Administrator's 
decision by taking one or more of the following actions:
    (a) The applicant may submit new or additional information in 
support of the application.
    (b) The applicant may request that the Administrator reconsider the 
data and information already submitted.
    (c) The applicant may request that any test conducted by the 
Administrator that was a material factor in the decision to reject the 
application be repeated.


Sec. 53.11  Cancellation of reference or equivalent method designation.

    (a) Preliminary finding. If the Administrator makes a preliminary 
finding on the basis of any available information that a representative 
sample of a method designated as a reference or equivalent method and 
offered for sale as such does not fully satisfy the requirements of 
this part or that there is any violation of the requirements set forth 
in Sec. 53.9, the Administrator may initiate proceedings to cancel the 
designation in accordance with the following procedures.
    (b) Notification and opportunity to demonstrate or achieve 
compliance.
    (1) After making a preliminary finding in accordance with paragraph 
(a) of this section, the Administrator will send notice of the 
preliminary finding to the applicant, together with a statement of the 
facts and reasons on which the preliminary finding is based, and will 
publish notice of the preliminary finding in the Federal Register.
    (2) The applicant will be afforded an opportunity to demonstrate or 
to

[[Page 65801]]

achieve compliance with the requirements of this part within 60 days 
after publication of notice in accordance with paragraph (b)(1) of this 
section or within such further period as the Administrator may allow, 
by demonstrating to the satisfaction of the Administrator that the 
method in question satisfies the requirements of this part, by 
commencing a program to make any adjustments that are necessary to 
bring the method into compliance, or by taking such action as may be 
necessary to cure any violation of the requirements of Sec. 53.9. If 
adjustments are necessary to bring the method into compliance, all such 
adjustments shall be made within a reasonable time as determined by the 
Administrator. If the applicant demonstrates or achieves compliance in 
accordance with this paragraph (b)(2), the Administrator will publish 
notice of such demonstration or achievement in the Federal Register.
    (c) Request for hearing. Within 60 days after publication of a 
notice in accordance with paragraph (b)(1) of this section, the 
applicant or any interested person may request a hearing as provided in 
Sec. 53.12.
    (d) Notice of cancellation. If, at the end of the period referred 
to in paragraph (b)(2) of this section, the Administrator determines 
that the reference or equivalent method designation should be canceled, 
a notice of cancellation will be published in the Federal Register and 
the designation will be deleted from the list maintained under 
Sec. 53.8(c). If a hearing has been requested and granted in accordance 
with Sec. 53.12, action under this paragraph (d) will be taken only 
after completion of proceedings (including any administrative review) 
conducted in accordance with Sec. 53.13 and only if the decision of the 
Administrator reached in such proceedings is that the designation in 
question should be canceled.


Sec. 53.12  Request for hearing on cancellation.

    Within 60 days after publication of a notice in accordance with 
Sec. 53.11(b)(1), the applicant or any interested person may request a 
hearing on the Administrator's action. If, after reviewing the request 
and supporting data, the Administrator finds that the request raises a 
substantial issue of fact, a hearing will be granted in accordance with 
Sec. 53.13 with respect to such issue. The request shall be in writing, 
signed by an authorized representative of the applicant or interested 
person, and shall include a statement specifying:
    (a) Any objections to the Administrator's action; and
    (b) Data or other information in support of such objections.


Sec. 53.13  Hearings.

    (a)(1) After granting a request for a hearing under Sec. 53.12, the 
Administrator will designate a presiding officer for the hearing.
    (2) If a time and place for the hearing have not been fixed by the 
Administrator, the hearing will be held as soon as practicable at a 
time and place fixed by the presiding officer, except that the hearing 
shall in no case be held sooner than 30 days after publication of a 
notice of hearing in the Federal Register.
    (3) For purposes of the hearing, the parties shall include the 
Environmental Protection Agency, the applicant or interested person(s) 
who requested the hearing, and any person permitted to intervene in 
accordance with paragraph (c) of this section.
    (4) The Deputy General Counsel or the Deputy General Counsel's 
representative will represent the Environmental Protection Agency in 
any hearing under this section.
    (5) Each party other than the Environmental Protection Agency may 
be represented by counsel or by any other duly authorized 
representative.
    (b)(1) Upon appointment, the presiding officer will establish a 
hearing file. The file shall contain copies of the notices issued by 
the Administrator pursuant to Sec. 53.11(b)(1), together with any 
accompanying material, the request for a hearing and supporting data 
submitted therewith, the notice of hearing published in accordance with 
paragraph (a)(2) of this section, and correspondence and other material 
data relevant to the hearing.
    (2) The hearing file shall be available for inspection by the 
parties or their representatives at the office of the presiding 
officer, except to the extent that it contains information identified 
in accordance with Sec. 53.15.
    (c) The presiding officer may permit any interested person to 
intervene in the hearing upon such a showing of interest as the 
presiding officer may require; provided that permission to intervene 
may be denied in the interest of expediting the hearing where it 
appears that the interests of the person seeking to intervene will be 
adequately represented by another party (or by other parties), 
including the Environmental Protection Agency.
    (d)(1) The presiding officer, upon the request of any party or at 
the officer's discretion, may arrange for a prehearing conference at a 
time and place specified by the officer to consider the following:
    (i) Simplification of the issues.
    (ii) Stipulations, admissions of fact, and the introduction of 
documents.
    (iii) Limitation of the number of expert witnesses.
    (iv) Possibility of agreement on disposing of all or any of the 
issues in dispute.
    (v) Such other matters as may aid in the disposition of the 
hearing, including such additional tests as may be agreed upon by the 
parties.
    (2) The results of the conference shall be reduced to writing by 
the presiding officer and made part of the record.
    (e)(1) Hearings shall be conducted by the presiding officer in an 
informal but orderly and expeditious manner. The parties may offer oral 
or written evidence, subject to exclusion by the presiding officer of 
irrelevant, immaterial, or repetitious evidence.
    (2) Witnesses shall be placed under oath.
    (3) Any witness may be examined or cross-examined by the presiding 
officer, the parties, or their representatives. The presiding officer 
may, at his discretion, limit cross-examination to relevant and 
material issues.
    (4) Hearings shall be reported verbatim. Copies of transcripts of 
proceedings may be purchased from the reporter.
    (5) All written statements, charts, tabulations, and data offered 
in evidence at the hearing shall, upon a showing satisfactory to the 
presiding officer of their authenticity, relevancy, and materiality, be 
received in evidence and shall constitute part of the record.
    (6) Oral argument shall be permitted. The presiding officer may 
limit oral presentations to relevant and material issues and designate 
the amount of time allowed for oral argument.
    (f)(1) The presiding officer shall make an initial decision which 
shall include written findings and conclusions and the reasons therefor 
on all the material issues of fact, law, or discretion presented on the 
record. The findings, conclusions, and written decision shall be 
provided to the parties and made part of the record. The initial 
decision shall become the decision of the Administrator without further 
proceedings unless there is an appeal to, or review on motion of, the 
Administrator within 30 calendar days after the initial decision is 
filed.
    (2) On appeal from or review of the initial decision, the 
Administrator will have all the powers consistent with making the 
initial decision, including the discretion to require or allow briefs, 
oral argument, the taking of additional evidence or the remanding to 
the presiding officer for additional proceedings. The decision by the

[[Page 65802]]

Administrator will include written findings and conclusions and the 
reasons or basis therefor on all the material issues of fact, law, or 
discretion presented on the appeal or considered in the review.


Sec. 53.14  Modification of a reference or equivalent method.

    (a) An applicant who offers a method for sale as a reference or 
equivalent method shall report to the Administrator prior to 
implementation any intended modification of the method, including but 
not limited to modifications of design or construction or of 
operational and maintenance procedures specified in the operation 
manual [see Sec. 53.9(g)]. The report shall be signed by an authorized 
representative of the applicant, marked in accordance with Sec. 53.15 
(if applicable), and addressed as specified in Sec. 53.4(a).
    (b) A report submitted under paragraph (a) of this section shall 
include:
    (1) A description, in such detail as may be appropriate, of the 
intended modification;
    (2) A brief statement of the applicant's belief that the 
modification will, will not, or may affect the performance 
characteristics of the method;
    (3) A brief statement of the probable effect if the applicant 
believes the modification will or may affect the performance 
characteristics of the method; and
    (4) Such further information, including test data, as may be 
necessary to explain and support any statement required by paragraphs 
(b)(2) and (b)(3) of this section.
    (c) Within 30 calendar days after receiving a report under 
paragraph (a) of this section, the Administrator will take one or more 
of the following actions:
    (1) Notify the applicant that the designation will continue to 
apply to the method if the modification is implemented.
    (2) Send notice to the applicant that a new designation will apply 
to the method (as modified) if the modification is implemented, submit 
notice of the determination for publication in the Federal Register, 
and revise or supplement the list referred to in Sec. 53.8(c) to 
reflect the determination.
    (3) Send notice to the applicant that the designation will not 
apply to the method (as modified) if the modification is implemented 
and submit notice of the determination for publication in the Federal 
Register;
    (4) Send notice to the applicant that additional information must 
be submitted before a determination can be made and specify the 
additional information that is needed (in such cases, the 30-day period 
shall commence upon receipt of the additional information);
    (5) Send notice to the applicant that additional tests are 
necessary and specify what tests are necessary and how they shall be 
interpreted (in such cases, the 30-day period shall commence upon 
receipt of the additional test data); or
    (6) Send notice to the applicant that additional tests will be 
conducted by the Administrator and specify the reasons for and the 
nature of the additional tests (in such cases, the 30-day period shall 
commence one calendar day after the additional tests are completed).
    (d) An applicant who has received a notice under paragraph (c)(3) 
of this section may appeal the Administrator's action as follows:
    (1) The applicant may submit new or additional information 
pertinent to the intended modification.
    (2) The applicant may request the Administrator to reconsider data 
and information already submitted.
    (3) The applicant may request that the Administrator repeat any 
test conducted that was a material factor in the Administrator's 
determination. A representative of the applicant may be present during 
the performance of any such retest.


Sec. 53.15  Trade secrets and confidential or privileged information.

    Any information submitted under this part that is claimed to be a 
trade secret or confidential or privileged information shall be marked 
or otherwise clearly identified as such in the submittal. Information 
so identified will be treated in accordance with part 2 of this chapter 
(concerning public information).


Sec. 53.16  Supersession of reference methods.

    (a) This section prescribes procedures and criteria applicable to 
requests that the Administrator specify a new reference method, or a 
new measurement principle and calibration procedure on which reference 
methods shall be based, by revision of the appropriate appendix to 50 
part of this chapter. Such action will ordinarily be taken only if the 
Administrator determines that a candidate method or a variation thereof 
is substantially superior to the existing reference method(s).
    (b) In exercising discretion under this section, the Administrator 
will consider:
    (1) The benefits, in terms of the requirements and purposes of the 
Act, that would result from specifying a new reference method or a new 
measurement principle and calibration procedure;
    (2) The potential economic consequences of such action for State 
and local control agencies; and
    (3) Any disruption of State and local air quality monitoring 
programs that might result from such action.
    (c) An applicant who wishes the Administrator to consider revising 
an appendix to part 50 of this chapter on the ground that the 
applicant's candidate method is substantially superior to the existing 
reference method(s) shall submit an application for a reference or 
equivalent method determination in accordance with Sec. 53.4 and shall 
indicate therein that such consideration is desired. The application 
shall include, in addition to the information required by Sec. 53.4, 
data and any other information supporting the applicant's claim that 
the candidate method is substantially superior to the existing 
reference method(s).
    (d) After receiving an application under paragraph (c) of this 
section, the Administrator will publish notice of its receipt in the 
Federal Register and, within 120 calendar days after receipt of the 
application, take one of the following actions:
    (1) Determine that it is appropriate to propose a revision of the 
appendix to part 50 of this chapter in question and send notice of the 
determination to the applicant;
    (2) Determine that it is inappropriate to propose a revision of the 
appendix to part 50 of this chapter in question, determine whether the 
candidate method is a reference or equivalent method, and send notice 
of the determinations, including a statement of reasons for the 
determination not to propose a revision, to the applicant;
    (3) Send notice to the applicant that additional information must 
be submitted before a determination can be made and specify the 
additional information that is needed (in such cases, the 120-day 
period shall commence upon receipt of the additional information);
    (4) Send notice to the applicant that additional tests are 
necessary, specifying what tests are necessary and how they shall be 
interpreted (in such cases, the 120-day period shall commence upon 
receipt of the additional test data); or
    (5) Send notice to the applicant that additional tests will be 
conducted by the Administrator, specifying the nature of and reasons 
for the additional tests and the estimated time required (in such 
cases, the 120-day period shall

[[Page 65803]]

commence one calendar day after the additional tests have been 
completed).
    (e)(1)(i) After making a determination under paragraph (d)(1) of 
this section, the Administrator will publish a notice of proposed 
rulemaking in the Federal Register. The notice will indicate that the 
Administrator proposes:
    (A) To revise the appendix to part 50 of this chapter in question;
    (B) Where the appendix specifies a measurement principle and 
calibration procedure, to cancel reference method designations based on 
the appendix; and
    (C) To cancel equivalent method designations based on the existing 
reference method(s).
    (ii) The notice will include the terms or substance of the proposed 
revision, will indicate what period(s) of time the Administrator 
proposes to allow for replacement of existing methods under section 2.3 
of Appendix C to part 58 of this chapter, and will solicit public 
comments on the proposal with particular reference to the 
considerations set forth in paragraphs (a) and (b) of this section.
    (2) If, after consideration of comments received, the Administrator 
determines that the appendix to part 50 in question should be revised, 
the Administrator will by publication in the Federal Register 
promulgate the proposed revision, with such modifications as may be 
appropriate in view of comments received; where the appendix to part 50 
(prior to revision) specifies a measurement principle and calibration 
procedure, cancel reference method designations based on the appendix; 
cancel equivalent method designations based on the existing reference 
method(s); and specify the period(s) that will be allowed for 
replacement of existing methods under section 2.3 of Appendix C to part 
58 of this chapter, with such modifications from the proposed period(s) 
as may be appropriate in view of comments received. Canceled 
designations will be deleted from the list maintained under 
Sec. 53.8(c). The requirements and procedures for cancellation set 
forth in Sec. 53.11 shall be inapplicable to cancellation of reference 
or equivalent method designations under this section.
    (3) If the appendix to part 50 of this chapter in question is 
revised to specify a new measurement principle and calibration 
procedure on which the applicant's candidate method is based, the 
Administrator will take appropriate action under Sec. 53.5 to determine 
whether the candidate method is a reference method.
    (4) Upon taking action under paragraph (e)(2) of this section, the 
Administrator will send notice of the action to all applicants for 
whose methods reference and equivalent method designations are canceled 
by such action.
    (f) An applicant who has received notice of a determination under 
paragraph (d)(2) of this section may appeal the determination by taking 
one or more of the following actions:
    (1) The applicant may submit new or additional information in 
support of the application.
    (2) The applicant may request that the Administrator reconsider the 
data and information already submitted.
    (3) The applicant may request that any test conducted by the 
Administrator that was a material factor in making the determination be 
repeated.
Tables to Subpart A of Part 53

        Table A-1 to Subpart A--Summary of Applicable Requirements for Reference and Equivalent Methods for Air Monitoring of Criteria Pollutants       
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                                                  Applicable subparts of part 53        
              Pollutant                  Ref. or equivalent      Manual or automated    Applicable part  -----------------------------------------------
                                                                                          50 appendix        A       B       C       D       E       F  
--------------------------------------------------------------------------------------------------------------------------------------------------------
SO2.................................  Reference..............  Manual................  A                  ......  ......  ......  ......  ......  ......
                                      Equivalent.............  Manual................  .................                 >                         
                                                               Automated.............  .................         >       >                         
CO..................................  Reference..............  Automated.............  C                         >                                 
                                      Equivalent.............  Manual................  .................                 >                         
                                                               Automated.............  .................         >       >                         
O3..................................  Reference..............  Automated.............  D                         >                                 
                                      Equivalent.............  Manual................  .................                 >                         
                                                               Automated.............  .................         >       >                         
NO2.................................  Reference..............  Automated.............  F                         >                                 
                                      Equivalent.............  Manual................  .................                 >                         
                                                               Automated.............  .................         >       >                         
Pb..................................  Reference..............  Manual................  G                  ......  ......  ......  ......  ......  ......
                                      Equivalent.............  Manual................  .................                 >                         
PM10................................  Reference..............  Manual................  J                                         >                 
                                      Equivalent.............  Manual................  .................                 >       >                 
                                                               Automated.............  .................                 >       >                 
PM2.5...............................  Reference..............  Manual................  L                                                 >         
                                      Equivalent Class I.....  Manual................  L                                 >               >         
                                      Equivalent Class II....  Manual................  L                                 >               >       > 
                                      Equivalent Class III...  Manual or Automated...  .................             > \1\           > \1\   > \1\ 
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ Because of the wide variety of potential devices possible, the specific requirements applicable to a Class III candidate equivalent method for PM2.5
  are not specified explicitly in this part but, instead, shall be determined on a case-by-case basis for each such candidiate method.                  


[[Page 65804]]

Appendix A to Subpart A of Part 53--References

1. American National StandardQuality Systems-Model for Quality 
Assurance in Design, Development, Production, Installation, and 
Servicing, ANSI/ISO/ASQC Q9001-1994. Available from American Society 
for Quality Control, 611 East Wisconsin Avenue, Milwaukee, WI 53202.
2. American National Standard--Specifications and Guidelines for 
Quality Systems for Environmental Data Collection and Environmental 
Technology Programs, ANSI/ASQC E41994. Available from American 
Society for Quality Control, 611 East Wisconsin Avenue, Milwaukee, 
WI 53202.
3. Dimensioning and Tolerancing, ASME Y14.5M-1994. Available from 
the American Society of Mechanical Engineers, 345 East 47th Street, 
New York, NY 10017.
4. Mathematical Definition of Dimensioning and Tolerancing 
Principles, ASME Y14.5.1M-1994. Available from the American Society 
of Mechanical Engineers, 345 East 47th Street, New York, NY 10017.
5. ISO 10012, Quality assurance requirements for measuring 
equipmentPart 1: Meteorological confirmation system for measuring 
equipment):1992(E). Available from American Society for Quality 
Control, 611 East Wisconsin Avenue, Milwaukee, WI 53202.
6. Quality Assurance Handbook for Air Pollution Measurement Systems, 
Volume II, Ambient Air Specific Methods (Interim Edition), Section 
2.12. EPA/600/R-94/038b, April 1994. Available from CERI, ORD 
Publications, U.S. Environmental Protection Agency, 26 West Martin 
Luther King Drive, Cincinnati, Ohio 45268. [Note: Section 2.12 of 
Volume II is currently under development and will not be available 
from the CERI address until it is published as an addition to EPA/
600/R-94/038b. Prepublication draft copies of Section 2.12 will be 
available from Department E (MD-77B), U. S. EPA, Research Triangle 
Park, NC 27711 or from the contact identified at the beginning of 
this proposed rule.]

3. Subpart C is revised to read as follows:

Subpart C--Procedures for Determining Comparability Between Candidate 
Methods and Reference Methods
Sec.
53.30  General provisions.
53.31  Test conditions.
53.32  Test procedures for methods for SO2, CO, O3, and 
NO2.
53.33  Test procedure for methods for lead.
53.34  Test procedure for methods for PM10 and PM2.5

Tables to Subpart C of Part 53

Table C-1--Test Concentration Ranges, Number of Measurements 
Required, and Maximum Discrepancy Specification
Table C-2--Sequence of Test Measurements
Table C-3--Test Specifications for Lead Methods
Table C-4--Specifications for PM10 and PM2.5 Methods

Figures to Subpart C

Figure C-1--Suggested Format for Reporting Test Results

Appendix A to Subpart C to Part 53--References

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


Sec. 53.30  General provisions.

    (a) Determination of comparability. The test procedures prescribed 
in this Subpart shall be used to determine if a candidate method is 
comparable to a reference method when both methods measure pollutant 
concentrations in ambient air.
    (1) Comparability is shown for SO2, CO, O33, and NO2 
methods when the differences between:
    (i) Measurements made by a candidate manual method or by a test 
analyzer representative of a candidate automated method; and
    (ii) Measurements made simultaneously by a reference method, are 
less than or equal to the values specified in the last column of Table
C-1 of this subpart.
    (2) Comparability is shown for lead methods when the differences 
between:
    (i) Measurements made by a candidate method, and
    (ii) Measurements made by the reference method on simultaneously 
collected lead samples (or the same sample, if applicable), are less 
than or equal to the value specified in Table
C-3 of this subpart.
    (3) Comparability is shown for PM10 and PM2.5 methods 
when the relationship between:
    (i) Measurements made by a candidate method; and
    (ii) Measurements made by a reference method on simultaneously 
collected samples (or the same sample, if applicable) at each of two 
test sites, is such that the linear regression parameters (slope, 
intercept, and correlation coefficient) describing the relationship 
meet the values specified in Table C-4 of this subpart.
    (b) Selection of test sites. (1) All methods. Each test site shall 
be in a predominately urban area which can be shown to have at least 
moderate concentrations of various pollutants. The site shall be 
clearly identified and shall be justified as an appropriate test site 
with suitable supporting evidence such as maps, population density 
data, vehicular traffic data, emission inventories, pollutant 
measurements from previous years, concurrent pollutant measurements, 
and meteorological data. If approval of a proposed test site is desired 
prior to conducting the tests, a written request for approval of the 
test site or sites must be submitted prior to conducting the tests and 
must include the supporting and justification information required. The 
Administrator may exercise discretion in selecting a different site (or 
sites) for any additional tests the Administrator decides to conduct.
    (2) Methods for SO2, CO, O3, and NO2. All test 
measurements are to be made at the same test site. If necessary, the 
concentration of pollutant in the sampled ambient air may be augmented 
with artificially generated pollutant to facilitate measurements in the 
specified ranges. [See paragraph (d)(2) of this section.]
    (3) Methods for lead. Test measurements may be made at any number 
of test sites. Augmentation of pollutant concentrations is not 
permitted, hence an appropriate test site or sites must be selected to 
provide lead concentrations in the specified range.
    (4) Methods for PM10. Test measurements must be made, or 
derived from particulate samples collected, at not less than two test 
sites, each of which must be located in a geographical area 
characterized by ambient particulate matter that is significantly 
different in nature and composition from that at the other test 
site(s). Augmentation of pollutant concentrations is not permitted, 
hence appropriate test sites must be selected to provide PM10 
concentrations in the specified range. The tests at the two sites may 
be conducted in different calendar seasons, if appropriate, to provide 
PM10 concentrations in the specified ranges.
    (5) Methods for PM2.5. Augmentation of pollutant 
concentrations is not permitted, hence appropriate test sites must be 
selected to provide PM2.5 concentrations and PM2.5/PM10 
ratios (if applicable) in the specified ranges.
    (i) Where only one test site is required, as specified in Table C-4 
of this subpart, the site need only meet the PM2.5 ambient 
concentration levels required by Sec. 53.34(c)(3).
    (ii) Where two sites are required, as specified in Table C-4 of 
this subpart, each site must be selected to provide the ambient 
concentration levels required by Sec. 53.34(c)(3). In addition, one 
site

[[Page 65805]]

must be selected such that all acceptable test sample sets, as defined 
in Sec. 53.34(c)(3), have a PM2.5/PM10 ratio of more than 
0.75; the other site must be selected such that all acceptable test 
sample sets, as defined in Sec. 53.34(c)(3), have a PM2.5/
PM10 ratio of less than 0.40. At least two reference method 
PM10 samplers shall be collocated with the candidate and reference 
method PM2.5 samplers and operated simultaneously with the other 
samplers at each test site to measure concurrent ambient concentrations 
of PM10 to determine the PM2.5/PM10 ratio for each 
sample set. The PM2.5/PM10 ratio for each sample set shall be 
the average of the PM2.5 concentration, as determined in 
Sec. 53.34(c)(1), divided by the average PM10 concentration, as 
measured by the PM10 samplers. The tests at the two sites may be 
conducted in different calendar seasons, if appropriate, to provide 
PM2.5 concentrations and PM2.5/PM10 ratios in the 
specified ranges.
    (c) Test atmosphere. Ambient air sampled at an appropriate test 
site or sites shall be used for these tests. Simultaneous concentration 
measurements shall be made in each of the concentration ranges 
specified in Table C-1, C-3, or C-4 of this subpart, as appropriate.
    (d) Sample collection.
    (1) All methods. All test concentration measurements or samples 
shall be taken in such a way that both the candidate method and the 
reference method receive air samples that are homogenous or as nearly 
identical as practical.
    (2) Methods for SO2, CO, O3, and NO2. Ambient air 
shall be sampled from a common intake and distribution manifold 
designed to deliver homogenous air samples to both methods. Precautions 
shall be taken in the design and construction of this manifold to 
minimize the removal of particulates and trace gases, and to insure 
that identical samples reach the two methods. If necessary, the 
concentration of pollutant in the sampled ambient air may be augmented 
with artificially generated pollutant. However, at all times the air 
sample measured by the candidate and reference methods under test shall 
consist of not less than 80 percent ambient air by volume. Schematic 
drawings, physical illustrations, descriptions, and complete details of 
the manifold system and the augmentation system (if used) shall be 
submitted.
    (3) Methods for lead, PM10 and PM2.5. The ambient air 
intake points of all the candidate and reference method collocated 
samplers for lead, PM10 or PM2.5 shall be positioned at the 
same height above the ground level, and between 2 and 5 meters apart. 
The samplers shall be oriented in a manner that will minimize spatial 
and wind directional effects on sample collection.
    (4) PM10 methods employing the same sampling procedure as the 
reference method but a different analytical method. Candidate methods 
for PM10 which employ a sampler and sample collection procedure 
that are identical to the sampler and sample collection procedure 
specified in the reference method, but use a different analytical 
procedure, may be tested by analyzing common samples. The common 
samples shall be collected according to the sample collection procedure 
specified by the reference method and shall be analyzed in accordance 
with the analytical procedures of both the candidate method and the 
reference method.
    (e) Submission of test data and other information. All recorder 
charts, calibration data, records, test results, procedural 
descriptions and details, and other documentation obtained from (or 
pertinent to) these tests shall be identified, dated, signed by the 
analyst performing the test, and submitted. For candidate methods for 
PM2.5, all submitted information must meet the requirements of the 
ANSI/ASQC E4, sections 3.3.1, paragraphs 1 and 2 (Reference 1) of 
Appendix A of this Subpart.


Sec. 53.31  Test conditions.

    (a) All methods. All test measurements made or test samples 
collected by means of a sample manifold as specified in 
Sec. 53.30(d)(2) shall be at a room temperature between 20 deg. and 
30 deg.C, and at a line voltage between 105 and 125 volts. All methods 
shall be calibrated as specified in paragraph (c) of this section prior 
to initiation of the tests.
    (b) Samplers and automated methods. (1) Setup and start-up of the 
test analyzer, test sampler(s), and reference method (if applicable) 
shall be in strict accordance with the applicable operation manual(s). 
If the test analyzer does not have an integral strip chart or digital 
data recorder, connect the analyzer output to a suitable strip chart or 
digital data recorder. This recorder shall have a chart width of at 
least 25 centimeters, a response time of 1 second or less, a deadband 
of not more than 0.25 percent of full scale, and capability of either 
reading measurements at least 5 percent below zero or offsetting the 
zero by at least 5 percent. Digital data shall be recorded at 
appropriate time intervals such that trend plots similar to a strip 
chart recording may be constructed with a similar or suitable level of 
detail.
    (2) Other data acquisition components may be used along with the 
chart recorder during the conduct of these tests. Use of the chart 
recorder is intended only to facilitate visual evaluation of data 
submitted.
    (3) Allow adequate warmup or stabilization time as indicated in the 
applicable operation manual(s) before beginning the tests.
    (c) Calibration. The reference method shall be calibrated according 
to the appropriate appendix to part 50 of this chapter (if it is a 
manual method) or according to the applicable operation manual(s) (if 
it is an automated method). A candidate manual method (or portion 
thereof) shall be calibrated, according to the applicable operation 
manual(s), if such calibration is a part of the method.
    (d) Range. Except as provided in paragraph (d)(2) of this section, 
each method shall be operated in the range specified for the reference 
method in the appropriate appendix to part 50 of this chapter (for 
manual reference methods), or specified in Table B-1 of subpart B of 
this part (for automated reference methods).
    (e) Operation of automated methods. (1) Once the test analyzer has 
been set up and calibrated and tests started, manual adjustment or 
normal periodic maintenance is permitted only every 3 days. Automatic 
adjustments which the test analyzer performs by itself are permitted at 
any time. At 3-day intervals only adjustments and periodic maintenance 
as specified in the manual referred to in Sec. 53.4(b)(3) are 
permitted. The submitted records shall show clearly when manual 
adjustments were made and describe the operations performed.
    (2) All test measurements shall be made with the same test 
analyzer; use of multiple test analyzers is not permitted. The test 
analyzer shall be operated continuously during the entire series of 
test measurements.
    (3) If a test analyzer should malfunction during any of these 
tests, the entire set of measurements shall be repeated, and a detailed 
explanation of the malfunction, remedial action taken, and whether 
recalibration was necessary (along with all pertinent records and 
charts) shall be submitted.


Sec. 53.32  Test procedures for methods for SO2, CO, O3, and 
NO2.

    (a) Conduct the first set of simultaneous measurements with the 
candidate and reference methods:
    (1) Table C-1 of this subpart specifies the type (1- or 24-hour) 
and number of

[[Page 65806]]

measurements to be made in each of the three test concentration ranges.
    (2) The pollutant concentration must fall within the specified 
range as measured by the reference method.
    (3) The measurements shall be made in the sequence specified in 
Table C-2 of this subpart, except for the 1-hour SO2 measurements, 
which are all in the high range.
    (b) For each pair of measurements, determine the difference 
(discrepancy) between the candidate method measurement and reference 
method measurement. A discrepancy which exceeds the discrepancy 
specified in Table C-1 of this subpart constitutes a failure. (See 
Figure C-1 of this subpart for a suggested format for reporting the 
test results.)
    (c) The results of the first set of measurements shall be 
interpreted as follows:
    (1) Zero (0) failures. The candidate method passes the test for 
comparability.
    (2) Three (3) or more failures. The candidate method fails the test 
for comparability.
    (3) One (1) or two (2) failures. Conduct a second set of 
simultaneous measurements as specified in Table C-1 of this subpart. 
The results of the combined total of first-set and second-set 
measurements shall be interpreted as follows:
    (i) One (1) or two (2) failures. The candidate method passes the 
test for comparability.
    (ii) Three (3) or more failures. The candidate method fails the 
test for comparability.
    (4) For sulfur dioxide, the 1-hour and 24-hour measurements shall 
be interpreted separately, and the candidate method must pass the tests 
for both 1- and 24-hour measurements to pass the test for 
comparability.
    (d) A 1-hour measurement consists of the integral of the 
instantaneous concentration over a 60-minute continuous period divided 
by the time period. Integration of the instantaneous concentration may 
be performed by any appropriate means such as chemical, electronic, 
mechanical, visual judgment, or by calculating the mean of not less 
than 12 equally spaced instantaneous readings. Appropriate allowances 
or corrections shall be made in cases where significant errors could 
occur due to characteristic lag time or rise/fall time differences 
between the candidate and reference methods. Details of the means of 
integration and any corrections shall be submitted.
    (e) A 24-hour measurement consists of the integral of the 
instantaneous concentration over a 24-hour continuous period divided by 
the time period. This integration may be performed by any appropriate 
means such as chemical, electronic, mechanical, or by calculating the 
mean of twenty-four (24) sequential 1-hour measurements.
    (f) For oxidant and carbon monoxide, no more than six (6) 1-hour 
measurements shall be made per day. For sulfur dioxide, no more than 
four (4) 1-hour measurements or one (1) 24-hour measurement shall be 
made per day. One-hour measurements may be made concurrently with 24-
hour measurements if appropriate.
    (g) For applicable methods, control or calibration checks may be 
performed once per day without adjusting the test analyzer or method. 
These checks may be used as a basis for a linear interpolation-type 
correction to be applied to the measurements to correct for drift. If 
such a correction is used, it shall be applied to all measurements made 
with the method, and the correction procedure shall become a part of 
the method.


Sec. 53.33  Test procedure for methods for lead.

    (a) Sample collection. Collect simultaneous 24-hour samples 
(filters) of lead at the test site or sites with both the reference and 
candidate methods until at least 10 filter pairs have been obtained. If 
the conditions of Sec. 53.30(d)(4) apply, collect at least 10 common 
samples (filters) in accordance with Sec. 53.30(d)(4) and divide each 
to form the filter pairs.
    (b) Audit samples. Three audit samples must be obtained from the 
Quality Assurance Branch (MD-77B), Air Measurements Research Division, 
National Exposure Research Laboratory, U.S. Environmental Protection 
Agency, Research Triangle Park, NC 27711. The audit samples are \3/4\ 
x  8-inch glass fiber strips containing known amounts of lead at the 
following nominal levels: 100 g/strip; 300 g/strip; 
750 g/strip. The true amount of lead in total g/strip 
will be provided with each audit sample.
    (c) Filter analysis.
    (1) For both the reference method and the audit samples, analyze 
each filter extract 3 times in accordance with the reference method 
analytical procedure. The analysis of replicates should not be 
performed sequentially (i.e., a single sample should not be analyzed 
three times in sequence). Calculate the indicated lead concentrations 
for the reference method samples in g/m3 for each 
analysis of each filter. Calculate the indicated total lead amount for 
the audit samples in g/strip for each analysis of each strip. 
Label these test results as R1A, R1B, R1C, R2A, 
R2B, * * *, Q1A, Q1B, Q1C, * * *., where R denotes 
results from the reference method samples; Q denotes results from the 
audit samples; 1, 2, 3 indicates filter number and A, B, C indicates 
the first, second, and third analysis of each filter, respectively.
    (2) For the candidate method samples, analyze each sample filter or 
filter extract three times and calculate, in accordance with the 
candidate method, the indicated lead concentration in g/
m3 for each analysis of each filter. Label these test results as 
C1A, C1B, C2C, * * *, where C denotes results from the 
candidate method. (For candidate methods which provide a direct 
measurement of lead concentrates without a separable procedure, 
C1A=C1B=C1C, C2A=C2B=C2C, etc.)

[GRAPHIC] [TIFF OMITTED] TP13DE96.051


    (d) For the reference method, calculate the average lead 
concentration for each filter by averaging the concentrations 
calculated from the three analyses: where I is the filter number.
    (e) Disregard all filter pairs for which the lead concentration as 
determined in the previous paragraph (d) of this section by the average 
of the three reference method determinations, falls outside the range 
of 0.5 to 4.0 g/m3. All remaining filter pairs must be 
subjected to both of the following tests for precision and 
comparability. At least five filter pairs must be within the 0.5 to 4.0 
g/m3 range for the tests to be valid.
    (f) Test for precision. (1) Calculate the precision (P) of the 
analysis (in percent) for each filter and for each method, as the 
maximum minus the minimum divided by the average of the three 
concentration values, as follows:

[GRAPHIC] [TIFF OMITTED] TP13DE96.052


or
[GRAPHIC] [TIFF OMITTED] TP13DE96.053


where I indicates the filter number.
    (2) If any reference method precision value (PRi) exceeds 15 
percent, the precision of the reference method analytical procedure is 
out of control. Corrective action must be taken to determine the 
source(s) of imprecision and the reference method determinations must 
be repeated

[[Page 65807]]

according to paragraph (c) of this section, or the entire test 
procedure (starting with paragraph (a) of this section) must be 
repeated.
    (3) If any candidate method precision value (PCi) exceeds 15 
percent, the candidate method fails the precision test.
    (4) The candidate method passes this test if all precision values 
(i.e., all PRi's and all PCi's) are less than 15 percent.
    (g) Test for accuracy.
    (1) (i) For the audit samples calculate the average lead 
concentration for each strip by averaging the concentrations calculated 
from the three analyses:

[GRAPHIC] [TIFF OMITTED] TP13DE96.054


where i is audit sample number.
    (ii) Calculate the percent difference (Dq) between the 
indicated lead concentration for each audit sample and the true lead 
concentration (Tq) as follows:

[GRAPHIC] [TIFF OMITTED] TP13DE96.055


    (2) If any difference value (Dqi) exceeds 5 
percent the accuracy of the reference method analytical procedure is 
out of control. Corrective action must be taken to determine the source 
of the error(s) (e.g., calibration standard discrepancies, extraction 
problems, etc.) and the reference method and audit sample 
determinations must be repeated according to paragraph (c) of this 
section or the entire test procedure (starting with paragraph (a) of 
this section) must be repeated.
    (h) Test for comparability.
    (1) For each filter pair, calculate all nine possible percent 
differences (D) between the reference and candidate methods, using all 
nine possible combinations of the three determinations (A, B, and C) 
for each method, as:

[GRAPHIC] [TIFF OMITTED] TP13DE96.056


where i is the filter number, and n numbers from 1 to 9 for the nine 
possible difference combinations for the three determinations for each 
method (j= A, B, C, candidate; k= A, B, C, reference).
    (2) If none of the percent differences (D) exceed 20 
percent, the candidate method passes the test for comparability.
    (3) If one or more of the percent differences (D) exceed 
20 percent, the candidate method fails the test for 
comparability.
    (i) The candidate method must pass both the precision test and the 
comparability test to qualify for designation as an equivalent method.


Sec. 53.34  Test procedure for methods for PM10 and PM2.5.

    (a) Collocated measurements. Set up three reference method samplers 
collocated with three candidate method samplers or analyzers at each of 
the number of test sites specified in Table C-4 of this subpart. At 
each site, obtain as many sets of simultaneous PM10 or PM2.5 
measurements as necessary (see 53.34(c)(3)), each set consisting of 
three reference method and three candidate method measurements, all 
obtained simultaneously. For PM2.5 Class II candidate methods, at 
least two collocated PM10 reference method samplers are also 
required to obtain PM2.5/PM10 ratios for each sample set. 
Candidate PM10 method measurements shall be 24-hour integrated 
measurements; PM2.5 measurements may be either 24- or 48-hour 
integrated measurements. All collocated measurements in a sample set 
must cover the same 24- or 48-hour time period. For samplers, retrieve 
the samples promptly after sample collection and analyze each sample 
according to the reference method or candidate method, as appropriate, 
and determine the PM10 or PM2.5 concentration in g/
m3. If the conditions of Sec. 53.30(d)(4) apply, collect sample 
sets only with the three reference method samplers. Guidance for 
quality assurance procedures for PM2.5 methods is found in section 
2.12 of the Quality Assurance Handbook.
    (b) Sequential samplers. For sequential samplers, the sampler shall 
be configured for the maximum number of sequential samples and shall be 
set for automatic collection of all samples sequentially such that the 
test samples are collected equally, to the extent possible, among all 
available sequential channels or utilizing the full available 
sequential capability. At least 2 valid samples, one each above and 
below the applicable concentration limit specified in paragraph (c)(3) 
of this section, shall be obtained from each sequential channel in the 
maximum-channel configuration of the sampler.
    (c) Test for comparability. (1) For each of the measurement sets, 
calculate the average PM10 or PM2.5 concentration obtained 
with the reference method samplers:

[GRAPHIC] [TIFF OMITTED] TP13DE96.057


where R denotes results from the reference method, I is the sampler 
number, and j is the set.
    (2)(i) For each of the measurement sets, calculate the precision of 
the reference method PM10 or PM2.5 measurements as:

[GRAPHIC] [TIFF OMITTED] TP13DE96.058


if Rj is below:

80 g/m3 for PM10 methods;
40 g/m3 for 24-hour PM2.5 at single test sites for 
Class I candidate methods;
40 g/m3 for 24-hour PM2.5 at sites having 
PM2.5/PM10 ratios >0.75;
30 g/m3 for 48-hour PM2.5 at single test sites for 
Class I candidate methods;
30 g/m3 for 48-hour PM2.5 at sites having 
PM2.5/PM10 ratios >0.75;
30 g/m3 for 24-hour PM2.5 at sites having 
PM2.5/PM10 ratios <0.40; and
20 g/m3 for 48-hour PM2.5 at sites having 
PM2.5/PM10 ratios >0.75.

    (ii) Otherwise, calculate the precision of the reference method 
PM10 or PM2.5 measurements as:


[[Page 65808]]

[GRAPHIC] [TIFF OMITTED] TP13DE96.059



    (3) If Rj falls outside the acceptable concentration range 
specified in Table C-4 of this subpart for any set, or if Pj or 
RPj, as applicable, exceeds the value specified in Table C-4 of 
this subpart for any set, that set of measurements shall be discarded. 
For each site, Table C-4 of this subpart specifies the minimum number 
of sample sets required for various conditions, and Sec. 53.30(b)(5) 
specifies the PM2.5/PM10 ratio requirements applicable to 
Class II candidate equivalent methods. Additional measurement sets 
shall be collected and analyzed, as necessary, to provide a minimum of 
10 acceptable measurement sets for each test site. If more than 10 
measurement sets are collected that meet the above criteria, all such 
measurement sets shall be used to demonstrate comparability.
    (4) For each of the acceptable measurement sets, calculate the 
average PM10 or PM2.5 concentration obtained with the 
candidate method samplers:
[GRAPHIC] [TIFF OMITTED] TP13DE96.060


where C denotes results from the candidate method, I is the sampler 
number, and j is the set.
    (5) For each site, plot the average PM10 or PM2.5 
measurements obtained with the candidate method (Cj) against the 
corresponding average PM10 or PM2.5 measurements obtained 
with the reference method (Rj). For each site, calculate and 
record the linear regression slope and intercept, and the correlation 
coefficient.
    (6) If the linear regression parameters calculated above meet the 
values specified in Table C-4 of this subpart for all test sites, the 
candidate method passes the test for comparability.

Tables to Subpart C of Part 53

                      Table C-1.--Test Concentration Ranges, Number of Measurements Required, and Maximum Discrepancy Specification                     
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                            Simultaneous measurements required               Maximum    
                                                                                   ----------------------------------------------------    discrepancy  
               Pollutant                   Concentration range parts per million              1-hr                      24-hr            specification, 
                                                                                   ----------------------------------------------------     parts per   
                                                                                     First set    Second set   First set    Second set       million    
--------------------------------------------------------------------------------------------------------------------------------------------------------
Oxidants..............................  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  ................
--------------------------------------------------------------------------------------------------------------------------------------------------------


[[Page 65809]]


                Table C-2.--Sequence of Test Measurements               
------------------------------------------------------------------------
                                           Concentration range          
          Measurement           ----------------------------------------
                                      First set           Second set    
------------------------------------------------------------------------
1..............................  Low...............  Medum.             
2..............................  High..............  High.              
3..............................  Medium............  Low.               
4..............................  High..............  High.              
5..............................  Low...............  Medium.            
6..............................  Medium............  Low.               
7..............................  Low...............  Medium.            
8..............................  Medium............  Low.               
9..............................  High..............  High.              
10.............................  Medium............  Low.               
11.............................  High..............  Medium.            
12.............................  Low...............  High.              
13.............................  Medium............  Medium.            
14.............................  Low...............  High.              
15.............................  ..................  Low.               
16.............................  ..................  Medium.            
17.............................  ..................  Low.               
18.............................  ..................  High.              
------------------------------------------------------------------------


            Table C-3.--Test Specifications for Lead Methods            
------------------------------------------------------------------------
                                                                        
------------------------------------------------------------------------
Concentration range, g/m\3\..........................   0.5-4.0
Minimum number of 24-hr measurements..........................         5
Maximum analytical precision, percent.........................         5
Maximum analytical accuracy, percent..........................  10 and PM2.5 Methods                           
----------------------------------------------------------------------------------------------------------------
                                                                                    PM2.5                       
         Specification                      PM10           -----------------------------------------------------
                                                                     Class I                    Class II        
----------------------------------------------------------------------------------------------------------------
Acceptable concentration range   30-300...................  10-200...................  10-200                   
 (Rj), g/m3.                                                                                           
Minimum number of test sites...  2........................  1........................  2                        
Number of candidate method       3........................  3........................  3                        
 samplers per site.                                                                                             
Number of reference method       3........................  3........................  3                        
 samplers per site.                                                                                             
Minimum number of acceptable                                                                                    
 sample sets per site for PM10:                                                                                 
    Rj < 80 g/m3......  3........................  .........................  .........................
    Rj > 80 g/m3......  3........................  .........................  .........................
        Total..................  10.......................  .........................  .........................
Minimum number of acceptable                                                                                    
 sample sets per site for                                                                                       
 PM2.5:                                                                                                         
    Single test site for Class                                                                                  
     I candidate equivalent                                                                                     
     methods:                                                                                                   
        Rj < 40 g/m3      .......................  3a.......................  .........................
         for 24-hr or Rj < 30                                                                                   
         g/m3 for 48-                                                                                  
         hr samples.                                                                                            
        Rj > 40 g/m3      .......................  3a.......................  .........................
         for 24-hr or Rj > 30                                                                                   
         g/m3 for 48-                                                                                  
         hr samples.                                                                                            
    Sites at which the PM2.5/                                                                                   
     PM10 ratio must be > 0.75:                                                                                 
        Rj < 40 g/m3      .......................  .........................  3a                       
         for 24-hr or Rj < 30                                                                                   
         g/m3 for 48-                                                                                  
         hr samples.                                                                                            
        Rj > 40 g/m3      .......................  .........................  3a                       
         for 24-hr or Rj > 30                                                                                   
         g/m3 for 48-                                                                                  
         hr samples.                                                                                            
    Sites at which the PM2.5/                                                                                   
     PM10 ratio must be < 0.40:                                                                                 
        Rj < 30 g/m3      .......................  .........................  3a                       
         for 24-hr or Rj < 20                                                                                   
         g/m3 for 48-                                                                                  
         hr samples.                                                                                            
        Rj > 30 g/m3      .......................  .........................  3a                       
         for 24-hr or Rj > 20                                                                                   
         g/m3 for 48-                                                                                  
         hr samples.                                                                                            
Total, each site...............    .......................  10a......................  10a                      
Precision of replicate           5 g/m3 or 7%....  2 g/m3 or 5%....  2 g/m3 or 5%    
 reference method measurements,                                                                                 
 Pj or RPj.                                                                                                     
Slope of regression              10.1.........  10.05........  10.05        
 relationship.                                                                                                  
Intercept of regression          05...........  01...........  01           
 relationship, g/m3.                                                                                   
Correlation of reference method  0.97..........  0.97..........  0.97          
 and candidate method                                                                                           
 measurements.                                                                                                  
----------------------------------------------------------------------------------------------------------------
a For sequential samplers, at least 2 samples, one above and one below the applicable concentration limit shall 
  be obtained from each sequential channel in the maximum sequential configuration of the sampler. Therefore,   
  the number of samples in each category, and possibly the total number of samples, will be dependent on the    
  number of sequential channels available.                                                                      


BILLING CODE 6560-50-P

[[Page 65810]]

FIGURES TO SUBPART C OF PART 53

Figure C-1.--Suggested Format for Reporting Test Results
[GRAPHIC] [TIFF OMITTED] TP13DE96.061



[[Page 65811]]


BILLING CODE 6560-50-C

Appendix A to Subpart C of Part 53--References

    1. American National Standard--Specifications and Guidelines for 
Quality Systems for Environmental Data Collection and Environmental 
Technology Programs, ANSI/ASQC E4-1994. Available from American Society 
for Quality Control, 611 East Wisconsin Avenue, Milwaukee, WI 53202.
    4. Subpart E is added to read as follows:
Subpart E--Procedures for Testing Physical (Design) and Performance 
Characteristics of Reference Methods and Class I Equivalent Methods for 
PM.2.5
Sec.
53.50  General provisions.
53.51  Requirements to show compliance with design specifications.
53.52  Comprehensive procedure to test sampler performance under 
various environmental conditions (environmental chamber tests).
53.53  Post-sampling filter temperature control test.
53.54  Leak check test.
53.55  Flow rate cut-off test.
53.56  Operational field precision test.
53.57  Aerosol transport test for Class I sequential samplers.

Tables to Subpart E of Part 53

Table E-1--Test conditions for Sec. 53.52 comprehensive 24-hour 
tests
Table E-2--Summary of test requirements for reference and Class I 
equivalent methods for PM.2.5

Figures to Subpart E of Part 53

Figure E-1--Designation Check List
Figure E-2--Product Manufacturing Check List
Figure E-3--Suggested test configuration for simulating reduced 
barometric pressure for comprehensive test procedure (Sec. 53.52)

Appendix to Subpart E of Part 53--References

Subpart E--Procedures for Testing Physical (Design) and Performance 
Characteristics of Reference Methods and Class I Equivalent Methods 
for PM.2.5


Sec. 53.50  General provisions.

    (a) This subpart sets forth the specific tests that must be carried 
out and the test results, evidence, documentation, and other materials 
that must be provided to EPA to demonstrate that a PM2.5 sampler 
associated with a candidate reference method or Class I equivalent 
method meets all design and performance specifications set forth in 
Appendix L of part 50 of this chapter as well as additional 
requirements specified in this subpart E. Some of these tests may also 
be applicable to portions of a Class II or III equivalent method 
sampler, as determined under subpart F of this part.
    (b) Samplers associated with candidate reference methods for 
PM2.5 shall be subject to the provisions, specifications, and test 
procedures prescribed in Secs. 53.51 through 53.56. Samplers associated 
with candidate Class I equivalent method for PM2.5 shall be 
subject to the provisions, specifications, and test procedures 
prescribed in all sections of this Subpart. Samplers associated with 
candidate Class II or Class III equivalent method for PM2.5 shall 
be subject to the provisions, specifications, and test procedures 
prescribed in all applicable sections of this Subpart, as specified in 
subpart F of this part.
    (c) Section 53.51 pertains to test results and documentation 
required to demonstrate compliance of a candidate method sampler with 
the design specifications set forth in Appendix L of part 50 of this 
chapter. Test procedures prescribed in Secs. 53.52 through 53.56 
pertain to performance tests required to demonstrate compliance of a 
candidate method sampler with the performance specifications set forth 
in Appendix L of part 50 of this chapter, as well as additional 
requirements specified in this subpart E. These latter test procedures 
shall be used to test the performance of candidate samplers against the 
performance specifications and requirements specified in each procedure 
and summarized in Table E-1 of this subpart.

[[Page 65812]]

    (d) Test procedures prescribed in Sec. 53.57 do not apply to 
candidate reference method samplers. These procedures apply primarily 
to candidate class I equivalent method samplers for PM2.5 that 
have a sample air flow path configuration upstream of the sample filter 
that is modified from that specified for the reference method sampler--
as set forth in Drawings L-18 and L-24 of Appendix L to part 50 of this 
chapter to provide for sequential sample capability. The additional 
tests determine the adequacy of aerosol transport through any altered 
components or supplemental devices that are used in a candidate sampler 
upstream of the filter to achieve the sequential sample capability. 
These tests may also apply, with appropriate adaptation, if necessary, 
to candidate samplers having minor deviations from the specified 
reference method sampler for purposes other than sequential operation. 
In addition to the other test procedures in this subpart, these test 
procedures shall be used to further test the performance of such 
equivalent method samplers against the performance specifications given 
in Table E-2 of this subpart.
    (e) Tests of a candidate sampler for sample flow rate capacity and 
regulation, flow rate control, flow rate measurement accuracy, ambient 
temperature and pressure measurement accuracy, filter temperature 
control during sampling, and correct determination of elapsed sample 
time, average volumetric flow rate, and flow rate variation are all 
combined into a comprehensive test procedure (Sec. 53.52) that is 
carried out over four 24-hour test periods under multiple test 
conditions. Other performance parameters are tested individually with 
specific test procedures (Secs. 53.53--53.57).
    (f) A 10-day field test of measurement precision is required for 
both reference and equivalent method samplers. This test requires 
collocated operation of 3 candidate method samplers at a field test 
site. For candidate equivalent method samplers, this test may be 
combined and carried out concurrently with the test for comparability 
to the reference method specified under Sec. 53.34, which requires 
collocated operation of three reference method samplers and three 
candidate equivalent method samplers.
    (g) All tests and collection of test data shall be in accordance 
with the requirements of Reference 1, section 4.10.5 (ISO 9001) and 
Reference 2, Part B, section 3.3.1, paragraphs 1 and 2 and Part C, 
section 4.6 (ANSI/ASQC E4) in appendix A of this subpart. All test data 
and other documentation obtained specifically from or pertinent to 
these tests shall be identified, dated, signed by the analyst 
performing the test, and submitted to EPA in accordance with subpart A 
of this part.


Sec. 53.51  Requirements to show compliance with design specifications.

    For the purposes of this document the definitions of ISO registered 
facility and ISO-certified auditor are found in Sec. 53.1(t) and (u). 
An exception to this reliance by EPA on ISO affiliate audits is the 
requirement of the submission of the operation or instruction manual 
associated with the candidate method to EPA prior to designation. This 
manual is required under Sec. 53.4(b)(3). The EPA has determined that 
acceptable technical judgment for review of this manual may not be 
assured by ISO affiliates, and approval of this manual will therefore 
be accomplished by the EPA.
    (a) Overview. (1) In the absence of performance standards for some 
features of the FRM sampler system, and of the EPA resources to 
directly review and ensure manufacturer performance in producing 
samplers according to the EPA design specifications in 40 CFR part 50, 
Appendix L, EPA considers it necessary to require manufacturers to meet 
two kinds of requirements to ensure their compliance with the design 
specifications of 40 CFR part 50, Appendix L.
    (2) The subsequent paragraphs of this section specify certain 
documentation that must be submitted and tests that are required to 
demonstrate that instruments associated with a designated reference or 
equivalent method for PM2.5 are properly manufactured to meet all 
applicable design specifications and have been properly tested 
according to all applicable test requirements for such designation. 
Documentation is required to show that instruments and components are 
manufactured or assembled in an ISO-9001-registered (or equivalent) 
facility under a quality system that meets ISO-9001

[[Page 65813]]

requirements for manufacturing quality control and testing.
    (3) In addition, specific tests are required to verify that two 
critical features of reference method samplersimpactor jet diameter 
and the surface finish of surfaces specified to be anodizedmeet the 
specifications of 40 CFR part 50, Appendix L. A checklist is required 
to provide certification by an ISO-certified auditor that all 
performance and other required tests have been properly and 
appropriately conducted. Following designation of the method, another 
checklist is required, initially and annually, to provide an ISO-
qualified (or equivalent) auditor's certification that an adequate and 
appropriate quality system is being implemented in the instrument 
manufacturing process.
    (b) ISO Registration of manufacturing facility. (1) The applicant 
must submit documentation verifying that the samplers associated with 
the candidate method will be manufactured in an ISO 9001-registered 
facility (as defined in Sec. 53.1(u)) and that the manufacturing 
facility is maintained in compliance with all applicable ISO 9001 
requirements (Reference 1 in appendix A of this subpart). The 
documentation shall indicate the date of the original ISO 9001 
registration for the facility and shall include a copy of the most 
recent certification of continued ISO 9001 facility registration. If 
the manufacturer does not wish to initiate or complete ISO 9001 
registration for the manufacturing facility, documentation must be 
included in the application to EPA describing an alternative method to 
demonstrate that the facility meets the same general requirements as 
required for ISO registration. In this case, the applicant must provide 
documentation in the application to demonstrate, by required ISO-
certified auditor's inspections, that a quality system is in place 
which is adequate to document and monitor that the sampler system 
components all conform to the design, performance and other 
requirements specified in Appendix L of part 50 of this chapter.
    (2) Phase-in period. For a period of 1 year following the effective 
date of this subpart, a candidate reference or equivalent method for 
PM2.5 that utilizes a sampler manufactured in a facility that is 
not ISO 9001-registered or otherwise approved by the EPA under 
paragraph (b)(1) of this section may be conditionally designated as a 
reference or equivalent method under this part. Such conditional 
designation will be considered on the basis of evidence submitted in 
association with the candidate method application showing that 
appropriate efforts are currently underway to seek ISO 9001 
registration or alternative approval of the facility's quality system 
under paragraph (b)(1) of this section within the next 12 months. Such 
conditional designation shall expire 1 year after the date of the 
Federal Register notice of the conditional designation unless 
documentation verifying successful ISO 9001 registration for the 
facility or other EPA-acceptable quality system review and approval 
process of the production that will manufacture the samplers is 
submitted at least 30 days prior to the expiration date.
    (c) Sampler Manufacturing Quality Control. The manufacturer must 
ensure that all components used in the manufacture of PM2.5 
samplers to be sold as reference or equivalent methods and that are 
specified by design in Appendix L of part 50 of this chapter are 
fabricated or manufactured exactly as specified. If the manufacturer's 
QC records show that its QC and QA system of standard process control 
inspections (of a set number and frequency of testing that is less than 
100%) complies with the applicable QA provisions of section 4 of 
Reference 4 in Appendix A of this subpart and prevents nonconformances, 
100% testing shall not be required until that conclusion is disproved 
by customer return or other independent manufacturer or customer test 
records. If problems are uncovered, inspection to verify conformance to 
the drawings, specifications, and tolerances shall be performed. See 
also paragraph (e) of this section (final assembly and inspection 
requirements).
    (d) Specific tests and supporting documentation required to verify 
conformance to critical component specifications. (1) Verification of 
PM2.5 impactor jet diameter.  The diameter of the jet of each 
impactor manufactured for a PM2.5 sampler under the impactor 
design specifications set forth in Appendix L of part 50 of this 
chapter shall be verified against the tolerance specified on the 
drawing, using standard, NIST-traceable plug gages. This test shall be 
a final check of the jet diameter following all fabrication operations, 
and a record shall be kept of this final check. Submit evidence that 
this procedure is incorporated in the ISO 9001-certified manufacturing 
procedure, that the test is or will be routinely implemented, and that 
an appropriate procedure is in place for the disposition of units that 
fail this tolerance test.
    (2) Verification of surface finish. The anodization process used to 
treat surfaces specified to be anodized shall be verified by testing 
treated specimen surfaces for weight and corrosion resistance to ensure 
that the coating obtained conforms to the coating specification. The 
specimen surfaces shall be finished in accordance with military 
standard specification 8625F, Type II, Class I (Reference 4) in the 
same way the sampler surfaces are finished, and tested, prior to 
sealing, as specified in Section 4.5.2 of Reference 4 in Appendix A of 
this subpart.
    (e) Final assembly and inspection requirements. Each sampler shall 
be tested after manufacture and before delivery to the final user. Each 
manufacturer shall document its post-manufacturing test procedures. As 
a minimum, each test shall consist of the following: Tests of the 
overall integrity of the sampler, including leak tests; calibration or 
verification of the calibration of the flow measurement device, 
barometric pressure sensors, and temperature sensors; and operation of 
the sampler with a filter in place over a period of at least 48 hours. 
The results of each test shall be suitably documented and shall be 
subject to review by an ISO 9001 auditor.
    (f) Manufacturer's audit checklists. Manufacturers shall require 
ISO 9001 auditors to sign and date a statement indicating that the 
auditor is aware of the appropriate manufacturing specifications 
contained in Appendix L of part 50 of this chapter and the test or 
verification requirements in this subpart. Manufacturers shall also 
require ISO 9001 auditors to complete the checklists, shown in Figures 
E-1 and E-2 of this subpart, which describe the manufacturer's ability 
to meet the requirements of the standard for both designation testing 
and product

[[Page 65814]]

manufacture. Refer to Reference 5 for additional guidance on the scope 
and detail required for the checklist evaluations.
    (1) Designation testing checklist. The completed statement and 
checklist as shown in Figure E-1 of this subpart shall be submitted 
with the application for reference or equivalent method determination.
    (2) Product manufacturing checklist. Manufacturers shall require 
ISO 9001 auditors to complete the attached Production Checklist, which 
evaluates the manufacturer on its ability to meet the requirements of 
the standard in maintaining quality control in the production of 
reference or equivalent devices. The completed statement and checklist 
shall be submitted with the application for reference or equivalent 
method determination. As set forth in subpart A of this part, this 
checklist must be completed and submitted annually to retain a 
reference or equivalent method designation for a PM2.5 method.
    (3) If the conditions of paragraph (b)(2) of this section apply, a 
candidate reference or equivalent method for PM2.5 may be 
conditionally designated as a reference or equivalent method under this 
part 53 without the submission of the checklists described in 
paragraphs (f) (1) and (2) of this section. Such conditional 
designation shall expire 1 year after the date of the Federal Register 
notice of the conditional designation unless the checklists are 
submitted at least 30 days prior to the expiration date.


Sec. 53.52  Comprehensive procedure to test sampler performance under 
various environmental conditions (environmental chamber tests).

    (a) Overview. This test procedure is a combined procedure to test 
the following performance parameters:
    (1) Sample flow rate, flow rate regulation, and flow rate 
measurement accuracy;
    (2) Ambient air temperature and barometric pressure measurement 
accuracy;
    (3) Filter temperature control during sampling; and
    (4) Elapsed sampling time accuracy.
    The performance parameters tested under this procedure, the 
corresponding minimum performance specifications, and the applicable 
test conditions are summarized in Table E-2 of this subpart. Each 
performance parameter tested, as described or determined in the test 
procedure, must meet or exceed the performance specification given in 
Table E-2 of this subpart. The candidate sampler must meet all 
specifications for the associated PM2.5 method to be considered 
for designation as a reference or equivalent method.
    (b) Technical definition. Sample flow rate means the quantitative 
volumetric flow rate of the air stream caused by the sampler to enter 
the sampler inlet and pass through the sample filter, measured in 
actual volume units at the temperature and pressure of the air as it 
enters the inlet.
    (c) Required test equipment.
    (1) Environmental chamber or other temperature-controlled 
environment or environments, capable of obtaining and maintaining the 
various temperatures between -20  deg.C to +40  deg.C as required for 
the test with an accuracy of 2  deg.C. The test 
environment(s) must be capable of maintaining temperature within the 
specified limits continuously with the additional heat load of the 
operating test sampler in the environment. [Henceforth, where the test 
procedures specify a test or environmental ``chamber,'' an alternative 
temperature-controlled environmental area or areas may be substituted, 
provided the required test temperatures and all other test requirements 
are met. See paragraph (f)(1) of this section]
    (2) Variable voltage ac power transformer, range 100 to 130 Vac, 
with sufficient VA capacity to operate the test sampler continuously 
under the test conditions.
    (3) Flow rate meter, suitable for measuring the actual volumetric 
sampler flow rate at the sampler downtube in either an open system or 
in a closed system operating below atmospheric pressure, range 10 to 25 
actual L/min, 2 percent certified accuracy, NIST-traceable, over a 
temperature range of -30  deg.C to +50  deg.C and pressure range of 600 
to 800 mm Hg, with continuous (analog) recording capability or digital 
recording at intervals of not more than 5 minutes. Mass flow meter type 
recommended; however, note that temperature and pressure corrections 
are generally required to convert measured mass flow rate to actual 
volumetric flow rate.
    (4) Ambient air temperature recorder, range -30 deg.C to +50 deg.C, 
certified accurate to within 0.5  deg.C with a radiation error of 0.2 
deg.C or less under a solar radiation intensity of 1000 watts/m2, 
as described in Reference 6 in appendix A of this subpart.
    (5) Barometric pressure meter, range 600 to 800 mm Hg, certified 
accurate to 2 mm Hg.
    (6) Miniature temperature sensor, capable of being installed in the 
sampler without introducing air leakage and capable of measuring the 
sample air temperature within 1 cm of the center of the filter, 
downstream of the filter, certified accurate to within 0.5  deg.C, NIST 
traceable, with continuous (analog) recording capability or digital 
recording at intervals of not more than 5 minutes.
    (7) Means for creating or simulating the effect of a reduced 
barometric pressure on the test sampler during sampler operation, 
capable of simulating barometric pressures ranging from 730 to 600 mm 
Hg. A suggested, closed-system technique for a hypothetical sampler is 
illustrated in Figure E-3 of this subpart, but the configuration shown 
may have to be modified or adapted to accommodate the specific design 
of the actual candidate method sampler. The sampler-specific technique 
or apparatus proposed by the applicant for simulating barometric 
pressure for purposes of this test may be submitted for pre-approval of 
concept prior to conducting the test. Alternatively, a hypobarometric 
chamber or other test environment with capability of maintaining 
barometric pressures ranging from local actual barometric pressure to 
600 mm Hg, as well as the temperature capability specified in paragraph 
(c)(1) of this section, shall be used.
    (8) Means, such as a solar-spectrum lamp or lamps, for generating 
or simulating thermal radiation in approximate spectral content and 
intensity equivalent to solar insolation of 1000 watts/m2 (1.43 
langleys/min) inside the environmental chamber.
    (9) AC rms voltmeter, accurate to 0.5 volts.
    (10) Means for creating an additional pressure drop of 55 mm Hg in 
the sampler to simulate a heavily loaded filter, such as an orifice or 
flow restrictive plate installed in the filter holder or a valve or 
other flow restrictor temporarily installed in the flow path near the 
filter.
    (11) Time measurement system, accurate to within 10 seconds per 
day.
    (12) Radiometer, to measure the intensity of the simulated solar 
radiation in the test environment, range 0--1500/m2.
    (d) Calibration of test measurement instruments. Submit 
documentation showing evidence of recent calibration, calibration 
accuracy, and NIST-traceability (if required) of all measurement 
instruments used in the tests. The accuracy of flow meters shall be 
verified at the highest and lowest pressures and temperatures used in 
the tests and shall be checked at zero and one or more non-zero flow 
rates within 7 days of test use. Where an instrument's measurements are 
to be recorded with an analog recording

[[Page 65815]]

device, the accuracy of the entire instrument-recorder system shall be 
calibrated or verified.
    (e) Test setup. (1) The test sampler shall be set up for testing in 
the temperature-controlled chamber. Setup of the sampler shall be 
performed as described in the sampler's operation or instruction manual 
referred to in Sec. 53.4(b)(3). The sampler shall be installed upright 
and set up in its normal configuration for collecting PM2.5 
samples, except that the sample air inlet shall be removed to permit 
measurement of the sampler flow rate.
    (2) The certified flow rate meter shall be connected to the test 
sampler so as to accurately measure the sampler flow rate at the 
entrance to the sampler (i.e., the flow rate that would enter the 
sampler inlet if the inlet had not been removed).
    (3) The sampler shall be provided with ac line power from the 
variable voltage ac power transformer, which shall be initially set to 
a nominal voltage of 115 volts ac (rms).
    (4) The miniature temperature sensor shall be installed in the test 
sampler such that it accurately measures the air temperature 1 cm from 
the center of the filter on the downstream side of the filter. The 
sensor shall be installed in a way such that no external or internal 
leakage is created by the sensor installation.
    (5) If a closed-system means for simulating reduced barometric 
pressure in the sampler, as suggested in paragraph (c)(7) of this 
section, is to be used in lieu of a hypobarometric chamber, the 
necessary apparatus shall be installed on the test sampler as 
appropriate, in such a way that the certified flow rate meter will 
still accurately measure the sampler flow rate. Also, the barometric 
pressure meter shall be installed to accurately measure the simulated 
or actual reduced barometric pressure to which the sampler is subjected 
during the test.
    (6) The solar radiant energy source shall be installed in the test 
chamber such that the entire test sampler is irradiated in a manner 
similar to the way it would be irradiated by solar radiation if it were 
located outdoors in an open area on a sunny day, with the radiation 
arriving at an angle of between 30 and 45 degrees from vertical and 
such that the intensity of the radiation received by all sampler 
surfaces that receive direct radiation is not less than 1000 watts/
cm2, measured in a plane perpendicular to the incident radiation. 
The incident radiation shall be oriented with respect to the sampler 
such that the area of the sampler's ambient temperature sensor (or 
temperature shield) receives direct radiation as it would or could 
during normal outdoor installation. Also, the sensor must not be 
shielded from the radiation by a sampler part in a way that would not 
occur at other normal insolation angles or directions.
    (7) The ambient air temperature recorder shall be installed in the 
test chamber such that it will accurately measure the temperature of 
the air in the chamber without being unduly affected by the chamber's 
air temperature control system or by the radiant energy from the solar 
radiation source that may be present inside the test chamber.
    (f) Procedure. (1) The test sampler shall be tested during 
operation over four (4) 24-hour sample collection periods (Test numbers 
1--4) under the conditions specified in Table E-1 of this subpart. The 
test chamber temperature shall be held at the specified initial 
temperature for the first 8 hours of each test period, during which 
various performance parameters are measured. During hours 9 through 21 
of each test period, the chamber temperature is transitioned from the 
initial to the final specified temperature; the temperature profile is 
unspecified during this period, provided that the final specified 
temperature is achieved before the start of hour 22 of each test 
period. The specified final temperature shall be maintained during 
hours 22 through 24 of each test period.
    (2) Prepare the test sampler for normal sample collection operation 
as directed in the sampler's operation or instructional manual. If the 
sampler has multiple (sequential) sample capability, this capability 
may be used for the four 24-hour tests, if desired. Convenient start 
and stop times for a 240.1 hour test period shall be set in 
the test sampler to effect automatic sampler operation for each test 
period. Test periods are not required to start at midnight; each test 
period may start at any time of day.
    (3) Carry out a leak test of the sampler as described in the 
sampler's operation manual. The leak test must be properly passed 
before other tests are carried out.
    (4) At the beginning of each test period, the solar insolation 
source, as described in paragraph (c)(8) of this section, shall be off, 
and the sampler shall be subject to barometric pressure of not less 
than 730 mm Hg.
    (5) During each 24-hour test period, continuously record the test 
chamber air temperature, the filter temperature, and the sampler flow 
rate, as measured by the test equipment [paragraph (c) of this 
section], either via a continuous analog recording or digital recording 
at intervals of not more than 5 minutes. Note and record the actual 
start and stop times for the sample period. The sampler power line 
voltage shall be measured and recorded during hours 1 and 24 of the 
test period and following completion of the specific performance 
parameter tests during the initial 8-hour portion of the test period.
    (6) The following tests shall be carried out at some time during 
hours 1-8 of each 24-hour test period. The time at which the test data 
for each test are obtained (either time of day or elapsed time since 
the start of the 24-hour test period, whichever system is used to 
record flow rate and chamber temperature, to the closest 1 minute) 
shall be recorded along with the test data. If analog recording is 
used, the time of each test shall be identified or annotated directly 
on the strip chart record.
    (i) Determine and record the sampler flow rate, in actual 
volumetric units, indicated by the sampler, and the corresponding flow 
rate measured by the flow rate test meter specified in paragraph (c)(3) 
of this section.
    (ii) Determine and record the ambient (chamber) temperature 
indicated by the sampler and the corresponding ambient (chamber) 
temperature measured by the ambient temperature recorder specified in 
paragraph (c)(4) of this section.
    (iii) Determine and record the ambient (chamber) barometric 
pressure indicated by the sampler and the corresponding ambient 
(chamber) barometric pressure measured by the barometric pressure meter 
specified in paragraph (c)(5) of this section.
    (iv) Activate the solar radiation source; after at least 2 hours 
(120 minutes) of sampler operation following the start of simulated 
insolation exposure, repeat tests in paragraphs (f)(6) (i) and (ii) of 
this section under continuation of the insolation exposure.
    (v) Activate the solar radiation source; after at least 2 hours 
(120 minutes) of sampler operation following the start of simulated 
solar insolation exposure, subject the sampler to a barometric pressure 
(actual or simulated) of 600 mm Hg (absolute) while 
continuing the insolation exposure. After at least 1 hour (60 minutes) 
of sampler operation at this barometric pressure, repeat tests in 
paragraphs (f)(6) (i), (ii), and (iii) of this section under 
continuation of the reduced barometric pressure and insolation 
exposure.
    (vi) Activate the solar radiation source; after at least 2 hours 
(120 minutes) of sampler operation following the start of insolation 
exposure, subject the sampler to a barometric pressure (actual or 
simulated) of 600 mm Hg

[[Page 65816]]

while continuing the insolation exposure. After at least 1 hour (60 
minutes) of sampler operation at this barometric pressure, provide an 
additional filter pressure drop of 55 mm Hg, as specified in paragraph 
(c)(10) of this section and repeat tests in paragraphs (f)(6)(i), and 
(iii) of this section under continuation of the reduced barometric 
pressure, increased pressure drop, and insolation exposure. One or more 
of the power interruptions required in paragraph (f) (6)(vii) of this 
section may be used, if appropriate, to make necessary adjustments to 
the sampler to effect the additional filter pressure drop.
    (vii) Interrupt the ac line electrical power to the sampler for 
periods of 20 seconds, 40 seconds, 2 minutes, 7 minutes, and 20 
minutes, with not less than 5 minutes of electrical power, at the 
voltage specified for the test, between each power interruption. Record 
the hour and minute of each power interruption.
    (7) After completing the special tests under paragraph (f)(6) of 
this section, the remainder of the 24-hour test period may be completed 
with the test sampler subjected to any barometric pressure within the 
range specified in Table
E-2 of this subpart, with or without the additional filter pressure 
drop, and with the solar radiation either off or on.
    (g) Test Results. All requirements in this procedure must be passed 
in full for each of the four 24-hour tests; no provision is made for 
additional trials to compensate for failed tests. For each of the four 
24-hour test periods, validate the test conditions and determine the 
test results as follows:
    (1) Chamber temperature control. Examine the continuous record of 
the chamber temperature obtained in test procedure paragraph (f)(5) of 
this section and verify that the temperature met the requirements 
specified in Table E-1 of this subpart at all times during the test. If 
not, the entire 24-hour test is not valid and must be repeated.
    (2) Power line voltage. Verify that each of the three power line 
voltage measurements obtained in test procedure in paragraph (f)(5) of 
this section met the line voltage requirements specified in Table E-1 
of this subpart. If not, the entire 24-hour test is not valid and must 
be repeated.
    (3) Sample flow rate. (i) From the continuous record of the test 
sampler flow rate obtained from the flow rate meter in test procedure 
paragraph (f)(5) of this section, determine the average or 
instantaneous sampler flow rate, or average flow rate, at intervals of 
not more than 5 minutes for the entire 24-hour sample period. Calculate 
the percent difference between the sampler interval flow rate, in 
actual liters per minute (L/min), and 16.67 L/min, for each interval in 
test procedures in paragraphs (f)(6)(i), (6)(iv), (6)(v), and (6)(vi) 
of this section, as follows:

[GRAPHIC] [TIFF OMITTED] TP13DE96.062


Where Fi is the measured sampler flow rate for interval I, in 
actual L/min.
    (ii) All calculated sampler flow rate percent differences must meet 
the sample flow rate specification listed in Table E-2 of this subpart.
    (4) Sample flow rate regulation. (i) Using the sampler interval 
flow rates obtained in paragraph (g)(3) of this section, calculate the 
average sampler flow rate in actual liters per minute for the 24-hour 
period, excluding periods of electrical power interruption, as,

[GRAPHIC] [TIFF OMITTED] TP13DE96.063


where
Fave = average sampler flow rate over the 24-hour test period,
Fi = sampler flow rate for interval I
n = number of flow intervals over the 24-hour period, excluding 
intervals of no flow rate during power interruptions.
    (ii) For each interval over the 24-hour period, calculate the 
difference between the interval sampler flow rate and the average 
sampler flow rate. The difference between the interval sampler flow 
rate and the average sampler flow rate must meet the flow rate 
regulation specification listed in Table E-2 of this subpart for all 
intervals during the 24-hour test period, excluding periods of 
electrical power interruption.
    (5) Sample flow rate coefficient of variation. (i) Using the 
sampler interval flow rates determined in paragraph (g)(3) of this 
section, calculate the sampler flow rate coefficient of variation, 
CVflow as:

[GRAPHIC] [TIFF OMITTED] TP13DE96.064


Where

CVflow = coefficient of variation of sampler flow rate, and 
Fave, Fi, I, and n are as defined previously.

    (ii) The CVflow calculated must meet the sampler flow rate 
coefficient of variation specification listed in Table E-2 of this 
subpart for each test. Also the coefficient of variation reported by 
the sampler at the end of the sample period must agree with CVflow 
calculated here within 0.5%.
    (6) Flow rate measurement accuracy. (i)(A) Calculate the percent 
difference between the sampler flow rate, in actual liters per minute 
(L/min), indicated by the sampler, and the sampler flow rate measured 
with the flow rate test meter [paragraph (c)(3) of this section] in 
test procedures in paragraphs (f) (6)(i), (6)(iv), (6)(v), and (6)(vi) 
of this section, for each set of measurements as:

[GRAPHIC] [TIFF OMITTED] TP13DE96.065


Where

Fsi = sampler flow rate indicated by the sampler, in actual L/
min., for measurement set I.

    (B) All calculated sampler flow rate percent differences must meet 
the flow

[[Page 65817]]

rate measurement accuracy specification listed in Table E-2 of this 
subpart.
    (ii)(A) Obtain the value for the average sampler volumetric flow 
rate reported by the sampler at the end of the sample period and 
calculate the percent difference between the reported average sampler 
flow rate and the average flow rate determined in paragraph (f)(4) of 
this section as:

[GRAPHIC] [TIFF OMITTED] TP13DE96.066


Where

Fs,ave = average sampler flow rate reported by the sampler.

    (B) This calculated percent difference must also meet the flow rate 
measurement accuracy specification listed in Table E-2 of this subpart.
    (7) Ambient temperature measurement accuracy. (i) Calculate the 
difference between the ambient air temperature indicated by the sampler 
and the ambient (chamber) air temperature measured with the ambient air 
temperature recorder, paragraph (c)(4) of this section, in test 
procedures paragraphs (f) (6)(ii), (6)(iv), and (6)(v) of this section, 
as:

[GRAPHIC] [TIFF OMITTED] TP13DE96.067


Where

Ts = ambient air temperature indicated by the sampler,  deg.C; and
Tm = ambient air temperature measured by the test temperature 
instrument,  deg.C.

    (ii) All calculated temperature differences must meet the ambient 
air temperature measurement accuracy specification listed in Table E-2 
of this subpart.
    (8) Ambient barometric pressure measurement accuracy. (i) Calculate 
the difference between the ambient barometric pressure indicated by the 
sampler and the ambient barometric pressure measured with the ambient 
barometric pressure meter, paragraph (c)(5) of this section, in test 
procedures in paragraphs (f)(6)(iii), (6)(v), and (6)(vi) of this 
section, as:

[GRAPHIC] [TIFF OMITTED] TP13DE96.068


Where

Ps=ambient barometric pressure indicated by the sampler, mm Hg; 
and
Pm=ambient barometric pressure measured by the test barometric 
pressure meter, mm Hg.

    (ii) All calculated differences for barometric pressure must meet 
the ambient barometric pressure measurement accuracy specification 
listed in Table E-2 of this subpart.
    (9)(i) Filter temperature control (sampling). From the continuous 
record of the test sampler filter temperature obtained from the filter 
temperature sensor, paragraphs (c)(6) and (e)(4) of this section, in 
test procedure in paragraph (f)(5) of this section, determine the 
measured instantaneous or average filter temperature at intervals of 
not more than 5 minutes for the entire 24-hour sample period. From the 
continuous record of the ambient air temperature obtained from the 
ambient (chamber) air temperature recorder, paragraph (c)(4) of this 
section, in test procedure paragraph (f)(5) of this section, determine 
the measured instantaneous or average ambient (chamber) air temperature 
at intervals of not more than 5 minutes for the entire 24-hour sample 
period. For each interval over the 24-hour period (excluding intervals 
during power interruptions), calculate the difference, in  deg.C, 
between the measured interval filter temperature and the measured 
interval ambient temperature for the corresponding interval, as:

[GRAPHIC] [TIFF OMITTED] TP13DE96.069


    (ii) The difference between the interval filter temperature and the 
interval average ambient temperature for all intervals must meet the 
filter temperature control specification listed in Table E-2 of this 
subpart, excluding periods of electrical power interruption.
    (10) Elapsed sample time accuracy. Calculate the sample time for 
the 24-hour sample period as the difference between the sample end time 
and the sample start time, as recorded in paragraph (f)(5) of this 
section, less the total time duration of all power interruptions. The 
difference between the actual sampler time calculated and the sample 
time reported by the sampler at the end of the sample period must meet 
the elapsed sample time accuracy specification listed in Table E-2 of 
this subpart.
    (11) Record of power interruptions. Verify that the sampler 
provides a visual display of the correct year, month, day-of-month, 
hour, and minute, within 2 minutes, of the start of each 
power interruption of more than 60 seconds.


Sec. 53.53  Post-sampling filter temperature control test.

    (a) Overview. This procedure provides for testing the temperature 
control of the sample filter during the post-sampling (non-sampling) 
mode following sample collection. The test conditions and performance 
specifications are summarized in Table E-2 of this subpart. This 
performance parameter, when tested or determined as described in this 
test procedure, must meet or exceed the performance specification given 
in Table E-2 of this subpart for the associated PM2.5 method to be 
considered for designation as a reference or equivalent method.
    (b) Technical Definition. Post-sampling temperature control is the 
ability of a sampler to maintain the temperature of the particulate 
matter sample filter within the specified deviation from ambient 
temperature during the period between the end of active sample 
collection of the PM2.5 sample by the sampler until the filter is 
retrieved from the sampler for laboratory analysis.
    (c) Required test equipment. (1) Environmental chamber or other

[[Page 65818]]

temperature-controlled environment or environments, capable of 
obtaining and maintaining the various temperatures between -20  deg.C 
to +40  deg.C as required for the test with an accuracy of 
2  deg.C. The test environment(s) must be capable of 
maintaining temperature within the specified limits continuously with 
the additional heat load of the operating test sampler in the 
environment. [Henceforth, where the test procedures specify a test or 
environmental ``chamber,'' an alternative temperature-controlled 
environmental area or areas may be substituted, provided the required 
test temperatures and all other test requirements are met. See 
Sec. 53.52(f)(1)].
    (2) Variable voltage ac power transformer, range 100 to 130 Vac, 
with sufficient VA capacity to operate the sampler continuously under 
test conditions.
    (3) Ambient air temperature recorder, range -30 deg.C to +50 deg.C, 
certified accurate to within 0.5  deg.C with a radiation error of 0.2 
deg.C or less under a solar radiation intensity of 1000 watts/m2, 
as described in Reference 6 in Appendix A of this subpart.
    (4) Miniature temperature sensor, capable of being installed in the 
sampler without introducing air leakage and capable of measuring the 
sample air temperature within 1 cm of the center of the filter, 
downstream of the filter, certified accurate to within 0.5 deg.C, NIST 
traceable, with continuous (analog) recording capability or digital 
recording at intervals of not more than 5 minutes.
    (5) Means, such as a solar-spectrum lamp or lamps, for generating 
or simulating thermal radiation in approximate spectral content and 
intensity equivalent to solar insolation of 1000 watts/m2, inside 
the environmental chamber.
    (6) AC rms voltmeter, accurate to 0.5 volts.
    (7) Time measurement system, accurate to 10 seconds per day.
    (d) Calibration of test measurement instruments. Submit 
documentation showing evidence of recent calibration, calibration 
accuracy, and NIST-traceability (if required) of all measurement 
instruments used for the tests. Where an instrument's measurements are 
to be recorded with an analog recording device, the accuracy of the 
entire instrument-recorder system shall be calibrated or verified.
    (e) Test Setup. (1) The test sampler shall be set up for testing in 
the temperature-controlled chamber. Setup of the sampler shall be 
performed as described in the sampler's operation or instruction manual 
referred to in Sec. 53.4 (b)(3). The sampler shall be installed upright 
and set up in its normal configuration for collecting PM2.5 
samples with a filter installed, except that the sample air inlet may 
be removed, if desired.
    (2) The sampler shall be provided ac line power from the variable 
voltage ac power transformer, which shall be set to provide power to 
the sampler at a voltage of 105 1 volts ac (rms) during 
this test.
    (3) The miniature temperature sensor shall be installed in the test 
sampler such that it accurately measures the temperature of the air 1 
cm from the center of the filter on the downstream side of the filter.
    (4) The solar radiant energy source shall be installed in the test 
chamber such that the entire test sampler is irradiated in a manner 
similar to the way it would be irradiated by solar radiation if it were 
located outdoors in an open area on a sunny day, with the radiation 
arriving at an angle of between 30 and 45 degrees from vertical and 
such that the intensity of the radiation received by all sampler 
surfaces that receive direct radiation is not less than 1000 watts/
m2 (measured in a plane perpendicular to the incident radiation). 
The incident radiation shall be oriented with respect to the sampler 
such that the area of the sampler's ambient temperature sensor (or 
temperature sensor shield) receives direct radiation as it would or 
could during normal outdoor installation. Also, the sensor must not be 
shielded from the radiation by a sampler part in a way that would not 
occur at other normal insolation angles or directions.
    (5) The ambient air temperature recorder shall be installed in the 
test chamber such that it will accurately measure the temperature of 
the air in the chamber without being unduly affected by the chamber's 
air temperature control system or by the radiant energy from the solar 
radiation that may be present inside the test chamber.
    (f) Procedure. (1) The test sampler shall be tested during 
operation in the post-sample collection operational mode (operation of 
the sampler during the period from the end of active sample collection 
of the PM2.5 sample by the sampler until the filter is retrieved 
from the sampler for laboratory analysis) over seven (7) hours, 
following one of the 24-hour tests described in Sec. 53.52. The test 
chamber temperature shall be initially set to -20  deg.C, 
raised to 40  deg.C, held at 40  deg.C for one 
hour, then reduced to -20  deg.C during the test.
    (2) Prepare the sampler for the test by allowing the sampler to 
operate for a normal 24-hour sample collection period, as directed in 
the sampler's operation or instruction manual. If the sampler has 
multiple (sequential) sample capability, any of the sequential channels 
may be used for the test; however, if the sampler has multiple filter 
holders, each filter holder must be tested for temperature control. 
Convenient start and stop times for a 24  0.1 hour sample 
collection period shall be set in the sampler to effect automatic 
sampler operation for each test period. The active sample collection 
period may start at any time of day and is not required to start at 
midnight. One or more of the test periods associated with test 
procedure set forth in Sec. 53.52 may be used for this test 
preparation.
    (3) At the beginning of the 7-hour test period, the solar 
insolation source, as described in paragraphs (c)(4) and (e)(4) of this 
section, shall be on, the ambient (chamber) temperature shall be set to 
-20  deg.C, and the sampler power line voltage shall be set 
to 105 1 volts ac (rms).
    (4) During the 7-hour test period, continuously record the test 
chamber air temperature and the filter temperature, as measured by the 
test equipment in paragraph (c) of this section, either via a 
continuous analog recording or digital recording at intervals of not 
more than 5 minutes. Note and record the actual start and stop times 
for the sample period. The sampler power line voltage shall be measured 
during hours 1 and 7 of the test and at any other time during the test 
period when there is a possibility that the voltage may have changed.
    (5) During the first 3 hours of the test, the chamber air 
temperature shall be increased such that the chamber air temperature is 
40  deg.C 3 hours after the beginning of the test. The 
chamber air temperature shall be maintained at 40  deg.C for 
one hour (until 4 hours after the beginning of the test), then 
decreased over the next 3 hours of the test such that the chamber air 
temperature is -20  deg.C at the end of the test (7 hours 
after the beginning of the test. The chamber air temperature profile 
during the first and last three hours of the test is unspecified, 
provided the initial, central hour, and final temperatures are as 
specified in paragraph (f)(1) of this section.
    (g) Test Results--(1) Filter temperature control (post-sampling). 
From the continuous record of the test sampler filter temperature 
obtained from the filter temperature sensor, paragraphs (c)(3) and 
(e)(3) of this section, determine the measured instantaneous or average 
filter temperature at intervals of not more than 5 minutes for the 
entire 7-hour test

[[Page 65819]]

period. From the continuous record of the ambient air temperature 
obtained from the ambient (chamber) air temperature recorder, 
paragraphs (c)(4) and (e)(5) of this section, determine the measured 
instantaneous or average ambient (chamber) air temperature at the same 
intervals used for filter temperature for the entire 7-hour sample 
period. For each interval over the 7-hour period, calculate the 
difference, in  deg.C, between the measured interval filter temperature 
and the measured interval ambient temperature for the corresponding 
interval, as:

[GRAPHIC] [TIFF OMITTED] TP13DE96.070


    (2) The difference between the interval filter temperature and the 
interval average ambient temperature for each and all intervals must 
meet the filter temperature control specification listed in Table E-2 
of this subpart, excluding periods of electrical power interruption, if 
any.


Sec. 53.54  Leak check test.

    (a) Overview. Under section 7.4.6 of Appendix L of part 50 of this 
chapter, the sampler is required to include a facility--including 
components, instruments, operator controls, a written procedure, and 
other capabilities as necessary--to allow the operator to carry out a 
leak test of the sampler at a field monitoring site without additional 
equipment. This procedure is intended to test the adequacy and 
effectiveness of the sampler's leak check facility. Because of the 
variety of potential sampler configurations and leak check procedures 
possible, some adaptation of this procedure may be necessary to 
accommodate the specific sampler under test.
    (b) Technical definitions. (1) External leakage includes the total 
flow rate of external ambient air which enters the sampler other than 
through the sampler inlet and which passes through any one or more of 
the impactor, filter, or flow rate measurement components.
    (2) Internal leakage is the total sample air flow rate that passes 
through the filter holder assembly without passing through the sample 
filter.
    (c) Required test equipment.
    (1) Flow rate measurement device, range 70 to 130 mL/min, 2 percent 
certified accuracy, NIST-traceable.
    (2) Flow control device, capable of providing a controlled, 
simulated leak flow rate of 100 mL/min.
    (3) Flow rate measurement adaptor (Drawing L-27, Appendix L of part 
50 of this chapter) or equivalent adaptor to facilitate measurement of 
sampler flow rate.
    (4) A disk, such as a sample filter that is heavily loaded or a 
flow-impervious membrane containing one or more pinholes, which can be 
installed into the sampler's filter cassette (either with or without a 
normal sample filter) and which blocks the normal flow rate through the 
filter cassette but which, instead, provides a simulated leak flow rate 
through the disk of not more than 100 mL/min under the conditions 
specified for the leak check in the sampler's leak check procedure.
    (d) Calibration of test measurement instruments. Submit 
documentation showing evidence of recent calibration, calibration 
accuracy, and NIST-traceability (if required) of all measurement 
instruments used in the tests. The accuracy of flow meters shall be 
verified at the highest and lowest pressures and temperatures used in 
the tests and shall be checked at zero and one or more non-zero flow 
rates within 7 days of test use.
    (e) Test setup. (1) The test sampler shall be set up for testing as 
described in the sampler's operation or instruction manual referred to 
in Sec. 53.4(b)(3). The sampler shall be installed upright and set up 
in its normal configuration for collecting PM2.5 samples, except 
that the sample air inlet shall be removed and a device such as a flow 
rate measurement adaptor shall be installed on the sampler's downtube.
    (2) The flow rate control device shall be set up to provide a 
constant, controlled flow rate of 100 mL/min into the sampler downtube 
under the conditions specified for the leak check in the sampler's leak 
check procedure.
    (3) The flow rate measurement device shall be set up to measure the 
controlled flow rate of 100 mL/min into the sampler downtube under the 
conditions specified for the leak check in the sampler's leak check 
procedure.
    (f) Procedure. (1) Install a sample filter in the test sampler and 
ensure that the sampler has no internal or external leaks.
    (2) Carry out both the external and internal leak check procedure 
as described in the sampler's operation/instruction manual and verify 
that both leak checks indicate no significant leaks in the test 
sampler.
    (3) Arrange the flow control device, flow rate measurement device, 
and other apparatus as necessary to provide a simulated leak flow rate 
of 100 mL/min into the test sampler through the downtube during the 
specified external leak check procedure. Carry out the external leak 
check procedure as described in the sampler's operation/instruction 
manual but with the simulated leak of 100 mL/min.
    (4) Install the disk that simulates a filter-bypass leak in the 
filter cassette and carry out the internal leak check procedure as 
described in the sampler's operation/instruction manual.
    (g) Test results. The requirements for successful passage of this 
test are:
    (1) That the leak check procedure indicates no significant external 
or internal leaks in the test sampler when no simulated leaks are 
introduced.
    (2) That the external leak check procedure properly identifies the 
simulated external leak of 100 mL/min.
    (3) That the internal leak check procedure properly identifies the 
simulated internal leak of 100 mL/min.


Sec. 53.55  Flow rate cut-off test.

    (a) Overview. This test is intended to verify that the sampler 
carries out the required automatic sample flow rate cut-off function 
properly.
    (b) Technical definition. The flow rate-cut off function requires 
the sampler to automatically stop sample flow and terminate the current 
sample collection if the sample flow rate becomes less than the minimum 
flow rate specified in Table E-2 of this subpart (10 percent below the 
nominal sample flow rate) for more than 60 seconds during a sample 
collection period.
    (c) Required test equipment. (1) Flow rate meter, suitable for 
measuring the sampler flow rate at the sampler inlet in a closed system 
below atmospheric pressure, range 10 to 25 actual L/min, 2 percent 
certified accuracy, NIST-traceable, with continuous (analog) recording 
capability or digital recording at intervals of not more than 5 
seconds. Mass flow meter type recommended; however, note that 
temperature and pressure corrections are generally required to convert 
measured mass flow rate to actual volumetric flow rate.
    (2) Valve or other means to restrict or reduce the sample flow 
rate.
    (d) Calibration of test measurement instruments. Submit 
documentation showing evidence of recent calibration, calibration 
accuracy, and NIST-traceability of the flow rate meter used for this 
test. The accuracy of the flow meter shall be verified at the highest

[[Page 65820]]

and lowest pressures used in the tests and shall be checked at zero and 
one or more non-zero flow rates within 7 days of test use. Where an 
instrument's measurements are to be recorded with an analog recording 
device, the accuracy of the entire instrument-recorder system shall be 
calibrated or verified.
    (e) Test setup. (1) The test sampler shall be set up for testing at 
any temperature and barometric pressure within the specified ranges. 
Setup of the sampler shall be performed as described in the sampler's 
operation or instruction manual referred to in Sec. 53.4(b)(3). The 
sampler shall be installed upright and set up in its normal 
configuration for collecting PM2.5 samples, except that the sample 
air inlet shall be removed to permit measurement of the sampler flow 
rate by the certified flow rate meter.
    (2) The flow rate meter shall be connected so as to measure the 
sampler flow rate at the entrance to the sampler (i.e. the flow rate 
that would enter the sampler inlet if the inlet had not been removed).
    (3) The valve or means for reducing sampler flow rate shall be 
installed such that the sampler flow rate can be manually restricted 
during the test.
    (f) Procedure. (1) Prepare the sampler for normal sample collection 
operation as directed in the sampler's operation or instruction manual. 
Set the sampler to automatically start a normal 24-hour sampler 
collection period at a convenient time.
    (2) Continuously record the sampler flow rate and the time during 
the sample period, with at least 5-minute resolution during the normal 
operation of the sampler and at least 5-second resolution during the 
time period when the sampler flow rate is manually reduced.
    (3) After at least 1 hour of normal sampler operation at a sample 
flow rate within the specified flow rate range specified in Table E-2 
of this subpart, manually restrict the sampler flow rate such that the 
sampler flow rate is decreased slowly over several minutes to a flow 
rate less than the flow rate cut off value specified in Table E-2 of 
this subpart. Maintain this flow rate for at least 2.0 minutes or until 
the sampler stops the sample flow automatically.
    (g) Test Results. (1) Inspect the continuous record of the sampler 
flow rate and determine the time at which the sampler flow rate 
decreases to a value less than the cut-off value specified in Table E-2 
of this subpart. To pass this test, the sampler must automatically stop 
the sampler flow at least 30 seconds but not more than 50 seconds after 
the time at which the sampler flow rate was determined to have 
decreased to a value less than the value specified in Table E-2 of this 
subpart.
    (2) Verify that the elapsed sample time and average flow rate 
reported by the sampler for this test sample period are accurate within 
2 percent. The sampler must provide the same information to the 
operator as is required following a normal sample collection period, 
and the information reported in this test must accurately reflect the 
substantially shortened sample collection period caused by the 
automatic sample flow cut off.
    (3) Verify that the sampler's required ``Flow-out-of-spec'' and the 
``Incorrect sample period'' flag indicators are set at the end of the 
test.


Sec. 53.56  Operational field precision test.

    (a) Overview. This test is intended to determine the operational 
precision of the candidate sampler during a minimum of 10 days of field 
operation, using three collocated test samplers. Measurements of 
PM2.5 are made with all of the samplers and then compared to 
determine replicate precision. This procedure is applicable to both 
reference and equivalent methods. In the case of equivalent methods, 
this test may be combined and conducted concurrently with the 
comparability test for equivalent methods (subpart C of this part), 
using three reference method samplers collocated with three candidate 
equivalent method samplers and meeting the applicable site and other 
requirements of subpart C of this part.
    (b) Technical definition. Field precision means the standard 
deviation or relative standard deviation of a set of measurements 
obtained concurrently with three or more collocated samplers in actual 
ambient air field operation.
    (c) Test site. Any outdoor test site having PM2.5 
concentrations that are reasonably uniform over the test area and that 
meet the minimum level requirement of Sec. 53.56(g) is acceptable for 
this test.
    (d) Required facilities and equipment. An appropriate test site and 
suitable electrical power to accommodate three test samplers.
    (e) Test setup. (1) Three identical test samplers shall be 
installed at the test site in their normal configuration for collecting 
PM2.5 samples in accordance with the instructions in the 
associated manual referred to in Sec. 53.4(b)(3) and in accordance with 
applicable supplemental guidance provided in Reference 3 in Appendix A 
of this subpart. The test sampler inlet openings shall be located at 
the same height above ground and between 2 and 4 meters apart 
horizontally. The samplers shall be arranged or oriented in a manner 
that will minimize spatial and wind directional effects on sample 
collection of one sampler on the other samplers.
    (2) Each test sampler shall be leak checked, calibrated, and set up 
for normal operation in accordance with the instruction manual and with 
any applicable supplemental guidance provided in Reference 3 in 
Appendix A of this supbart.
    (f) Test procedure. (1) Install a specified filter in each sampler 
and otherwise prepare each sampler for normal sample collection. Set 
identical sample collection start and stop times for each sampler.
    (2) Collect either a 24-hour or a 48-hour atmospheric PM2.5 
sample simultaneously with each of the three test samplers.
    (3) Determine the measured PM2.5 mass concentration for each 
sample in accordance with the procedures prescribed for the candidate 
method in the associated manual referred to in Sec. 53.4(b)(3) and in 
accordance with supplemental guidance in Reference 3 in Appendix A of 
this subpart.
    (4) Repeat this procedure to obtain a total of 10 sets of 24-hour 
or 48-hour PM2.5 measurements over 10 test periods.
    (g) Calculations. (1) Record the PM2.5 concentration for each 
test sampler for each test day as Ci,j, where I is the sampler 
number (I=1,2,3) and j is the test day (j=1,2, . . . 10).
    (2) For each test day, calculate and record the average of the 
three measured PM2.5 concentrations as Cj where j is the test 
day:

[GRAPHIC] [TIFF OMITTED] TP13DE96.071


    If Cj<10 g/m\3\ for any test day, data from that test 
day are unacceptable and an additional sample collection set must be 
performed to replace the unacceptable data.
    (3) Calculate and record the precision for each of the 10 test days 
as:


[[Page 65821]]

[GRAPHIC] [TIFF OMITTED] TP13DE96.072



    if Cj is below 40 g/m\3\ for 24-hour measurements or 
below 30 g/m\3\ for 48-hour measurements; or

[GRAPHIC] [TIFF OMITTED] TP13DE96.073


    if Cj is above 40 g/m3 for 24-hour measurements 
or above 30 g/m3 for 48-hour measurements.
    (h) Test results. The candidate method passes the precision test if 
all 10 Pj or RPj values meet the specifications in Table E-2 
of this subpart.


Sec. 53.57  Aerosol transport test for class I sequential samplers

    (a) Overview. This test is intended to verify adequate aerosol 
transport through any air flow splitting components that may be used in 
a Class I candidate equivalent method sampler to achieve sequential 
sampling capability. This test is applicable to all Class I candidate 
samplers in which the aerosol flow path (the flow of air upstream of 
filtration) differs from that specified for reference method samplers 
as set forth in Drawings L-18 and L-24 of Appendix L to part 50 of this 
chapter. This test does not apply to candidate Class I equivalent 
method samplers in which each channel consists of a separate inlet, 
impactor, and filter holder of the exact same internal geometry as 
specified for the reference method sampler. The test requirements and 
performance specifications for this test are summarized in Table E-1 of 
this subpart.
    (b) Technical Definitions. (1) Aerosol transport is the percentage 
of the laboratory challenge aerosol which penetrates to the active 
sample filter of the candidate Class I sampler.
    (2) The active sample filter is the exclusive filter through which 
air is flowing during performance of this test.
    (3) A no-flow filter is a sample filter through which no air is 
flowing during performance of this test.
    (4) A channel is a flow path that the aerosol make take, only one 
of which may be active at a time.
    (5) An added component is any physical part of the sampler which is 
different from that specified for the reference method sampler and 
which allows or causes the aerosol to be routed to a different channel.
    (c) Required facilities and test equipment. (1) Aerosol generation 
system, as specified in Sec. 53.64(c)(1).
    (2) Aerosol delivery system, as specified in Sec. 53.64(c)(2).
    (3) Particle size verification equipment, as specified in 
Sec. 53.64(c)(3).
    (4) Fluorometer, as specified in Sec. 53.64(c)(4).
    (5) Candidate sampler, with the inlet and impactor or impactors 
removed, and with all internal surfaces of added components electroless 
nickel coated as specified in Sec. 53.64(d)(5)
    (d) Calibration of test measurement instruments. Submit 
documentation showing evidence of recent calibration, calibration 
accuracy, and NIST-traceability (if required) of all measurement 
instruments used for the tests. Where an instrument's measurements are 
to be recorded with an analog recording device, the accuracy of the 
entire instrument-recorder system shall be calibrated or verified.
    (e) Test setup. (1) The candidate sampler, with its inlet and 
impactor(s) removed, shall be installed in the particle delivery system 
so that the test aerosol is introduced at the top of the downtube that 
connects to the exit adaptor of the inlet. If the candidate sampler has 
a separate impactor for each channel, then for this test the filter 
holder assemblies must be connected to the physical location on the 
sampler where the impactors would normally connect.
    (2) Filters that are appropriate for use with fluorometric methods 
(e.g., glass fiber) shall be used for particle collection for these 
tests.
    (f) Procedure. (1) All surfaces of the added component(s) which 
come in contact with the aerosol flow shall be thoroughly washed with 
0.01 N NaOH and then dried.
    (2) Generate aerosol composed of oleic acid with a uranine 
fluorometric tag of 4 m 0.25 m using a 
vibrating orifice aerosol generator according to procedures specified 
in Sec. 53.61(g). Check for the presence of satellites and adjust the 
generator to minimize their production. Calculate the aerodynamic 
particle size using the operating parameters of the vibrating orifice 
aerosol generator and record. The calculated aerodynamic diameter must 
be within 0.25 m of 4 m.
    (3) Verify the particle size according to procedures specified in 
Sec. 53.62(d)(4)(i).
    (4) Collect particles on filters for a time period such that the 
relative error of the measured fluorometric concentration in the active 
filter is less than 5 percent.
    (5) Determine the quantity of material collected on the active 
filter using a calibrated fluorometer. Record the mass of fluorometric 
material for the active filter as Mactive(I) where I = active 
channel number.
    (6) Determine the quantity of material collected on the no-flow 
filter(s) using a calibrated fluorometer. Record the mass of 
fluorometric material on each no-flow filter as Mno-flow(ij) where 
I = active channel number and j = no-flow filter number.
    (7) Wash the surfaces of the added component(s) which contact the 
aerosol flow with 0.01N NaOH and determine the quantity of material 
collected using a calibrated fluorometer. Record the mass of 
fluorometric material collected in the wash as Mwash(I), where I = 
replicate number.

[[Page 65822]]

    (8) Calculate and record the aerosol transport as:

    [GRAPHIC] [TIFF OMITTED] TP13DE96.074
    

    where I = active channel number and j = no-flow filter number.

    (9) Repeat paragraphs (f) (1) through (6) of this section for each 
channel, making each channel in turn the exclusive active channel.
    (g) Evaluation of test results. The candidate Class I sampler 
passes the aerosol transport test if the specification in Table E-1 of 
this subpart is met for each channel.

Tables to Subpart E of Part 53

 Table E-1--Test Conditions for Sec.  53.52 Comprehensive 24-Hour Tests 
------------------------------------------------------------------------
                                               Initial         Final    
                                Power Line   temperature    temperature,
     24-hour test number         voltage     Deg C, Hours  Deg. C, Hours
                                                 1-8           22-24    
------------------------------------------------------------------------
1............................   105 -2  15.0 1   0.0            minus>2.0   
2............................   125 40
                                   minus>1   minus>2.0      .0          
3............................   125 40  15.0 1   .0             minus>2.0   
4............................   105 -2
                                   minus>1   minus>2.0      0.0         
------------------------------------------------------------------------


BILLING CODE 6560-50-P

[[Page 65823]]

[GRAPHIC] [TIFF OMITTED] TP13DE96.075



[[Page 65824]]

Figures to Subpart E
[GRAPHIC] [TIFF OMITTED] TP13DE96.076


[[Page 65825]]

[GRAPHIC] [TIFF OMITTED] TP13DE96.077



[[Page 65826]]

[GRAPHIC] [TIFF OMITTED] TP13DE96.078



[[Page 65827]]

Appendix A to Subpart E of Part 53--References

    1. ``Quality systems--Model for quality assurance in design, 
development, production, installation and servicing,'' ISO9001. July 
1994. Available from American Society for Quality Control, 611 East 
Wisconsin Avenue, Milwaukee, WI 53202.
    2. ``American National Standard--Specifications and Guidelines 
for Quality Systems for Environmental Data Collection and 
Environmental Technology Programs.'' ANSI/ASQC E4-1994. January 
1995. Available from American Society for Quality Control, 611 East 
Wisconsin Avenue, Milwaukee, WI 53202.
    3. Quality Assurance Handbook for Air Pollution Measurement 
Systems, Volume II, Ambient Air Specific Methods (Interim Edition), 
section 2.12. EPA/600/R-94/038b, April 1994. Available from CERI, 
ORD Publications, U.S. Environmental Protection Agency, 26 West 
Martin Luther King Drive, Cincinnati, Ohio 45268. [Section 2.12 is 
currently under development and will not be available from the 
previous address until it is published as an addition to EPA/600/R-
94/038b. Prepublication draft copies of section 2.12 will be 
available from Department E (MD-77B), U.S. EPA, Research Triangle 
Park, NC 27711 or from the contact identified at the beginning of 
this proposed rule].
    4. Military standard specification (mil. spec.) 8625F, Type II, 
Class 1 as listed in Department of Defense Index of Specifications 
and Standards (DODISS), available from DODSSP-Customer Service, 
Standardization Documents Order Desk, 700 Robbins Avenue, Building 
4D, Philadelphia, PA 1911-5094.
    5. ``Guidance for the Use and Application of Designation Testing 
and Sampler Manufacturing Checklists, as Required under 40 CFR 
53.51'' U.S. EPA Publication No. [To be prepared.]
    6. Quality Assurance Handbook for Air Pollution Measurement 
Systems, Volume IV: Meteorological Measurements. Revised March, 
1995. EPA-600/R-94-038d. Available from U.S. EPA, ORD Publications 
Office, Center for Environmental Research Information (CERI), 26 
West Martin Luther King Drive, Cincinnati, Ohio 45268-1072 (513-569-
7562).

    5. Subpart F is added to read as follows:

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

Sec.
53.60 General provisions.
53.61 Test conditions for PM2.5 reference method equivalency.
53.62 Test procedures: Full wind tunnel test.
53.63 Test procedures: Wind tunnel inlet aspiration test.
53.64 Test procedures: Static fractionator test.
53.65 Test procedures: Loading test.
53.66 Test procedures: Volatility test.

Tables to Subpart F of Part 53

Table F-1  Performance Specifications for PM2.5 Class II 
Equivalent Samplers
Table F-2  Particle Size and Wind Speeds for Full Wind Tunnel 
Evaluation, Wind Tunnel Inlet Aspiration Test, and Statics Chamber 
Test
Table F-3  Critical Parameters of Idealized Ambient Particle Size 
Distributions
Table F-4  Estimated Mass Concentration of PM2.5 for Idealized 
Coarse Aerosol Size Distribution
Table F-5  Estimated Mass Concentration Measurement of PM2.5 
for Idealized ``Typical'' Coarse Aerosol Size Distribution
Table F-6  Estimated Mass Concentration Measurement of PM2.5 
for Idealized Fine Aerosol Size Distribution

Figures to Subpart F of Part 53

Figure F-1  Flowchart for Determining Requirements for Class II 
Samplers Equivalent
Figure F-2  Designation Testing Checklist

Appendix A to Subpart F of Part 53--References

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


Sec. 53.60  General provisions.

    (a) This subpart sets forth the specific requirements that a 
PM2.5 sampler associated with a candidate Class II equivalent 
method must meet to be designated as an equivalent method for 
PM2.5. This subpart also sets forth the explicit test procedures 
that must be carried out and the test results, evidence, documentation, 
and other materials that must be provided to EPA to demonstrate that a 
sampler meets all specified requirements for designation as an 
equivalent method.
    (b) A candidate method described in an application for a reference 
or equivalent method application submitted under Sec. 53.4 shall be 
determined by the EPA to be a Class II candidate equivalent method on 
the basis of the definition of a Class II equivalent method given in 
Sec. 53.1.
    (c) Any sampler associated with a Class II candidate equivalent 
method (Class II sampler) must meet all requirements for reference 
method samplers or Class I equivalent method samplers specified in 
subpart E of this part, as appropriate. In addition, a Class II sampler 
must meet the additional requirements as specified in Sec. 53.60(d) of 
this part.
    (d) Except as provided in paragraph (d) (1), (2) and (3) of this 
section, all Class II samplers are subject to the additional tests and 
performance requirements specified in Sec. 53.62 (full wind tunnel 
test), Sec. 53.65 (loading test), and Sec. 53.66 (volatility test). 
Alternative tests and performance requirements, as described in 
paragraphs (d) (1), (2), and (3) of this section, are optionally 
available for certain Class II samplers which meet the requirements for 
reference method or Class I samplers given in Appendix L of part 50 of 
this chapter and in Subpart E of this part, except for specific 
deviations of the inlet, fractionator, or filter. These requirements 
and the exceptions in paragraphs (d) (1), (2), and (3) of this section 
are summarized in the flowchart given in Figure F-1 of this subpart.
    (1) Inlet deviation. A sampler which has been determined to be a 
Class II sampler (rather than a reference method or Class II sampler) 
solely because the design or construction of its inlet deviates from 
the design or construction of the inlet specified in Appendix L for 
reference method samplers shall not be subject to the requirements of 
Sec. 53.62 (full wind tunnel test), provided that it meets all 
requirements of Sec. 53.63 (inlet aspiration test), Sec. 53.65 (loading 
test), and Sec. 53.66 (volatility test).
    (2) Fractionator deviation. A sampler which has been determined to 
be a Class II sampler solely because the design or construction of its 
particle size fractionator deviates significantly from the design or 
construction of the particle size fractionator specified in 40 CFR part 
50, Appendix L for reference method samplers shall not be subject to 
the requirements of Sec. 53.62 (full wind tunnel test), provided that 
it meets all requirements of Sec. 53.64 (static fractionator test), 
Sec. 53.65 (loading test), and Sec. 53.66 (volatility test).
    (3) Filter size deviation. A sampler which has been determined to 
be a Class II sampler solely because the size of its sample collection 
filter deviates from the sampler filter size specified in Appendix L 
for reference method samplers shall not be subject to the requirements 
of Sec. 53.62 (full wind tunnel test) nor Sec. 53.65 (loading test), 
provided it meets all requirements of Sec. 53.66 (volatility test).
    (e) The test specifications and acceptance criteria for each test 
are summarized in Table F-1 of this subpart. The candidate sampler must 
demonstrate performance that meets the acceptance criteria for each 
applicable test to be designated as an equivalent method.
    (f) Overview of various test procedures for Class II samplers. (1) 
Full wind tunnel test. This test procedure is designed to ensure that 
the candidate sampler's aspiration of an ambient aerosol and 
penetration of the sub 2.5-micron fraction to its sample filter will be 
comparable to that of a reference method sampler. The test conditions 
are

[[Page 65828]]

summarized in Table F-2 of this subpart (under the heading, ``Full Wind 
Tunnel Test'), and the candidate sampler must meet the acceptance 
criteria specified in Table F-1 of this subpart.
    (2) Wind tunnel inlet test. The wind tunnel inlet aspiration test 
challenges the candidate sampler with a monodisperse aerosol that is 
specified in Table F-2 of this subpart (under the heading, ``Inlet 
Aspiration Test'). The aerosol is introduced into a wind tunnel 
environment, and the aspiration of the candidate sampler is compared 
with that of the reference method sampler at wind speeds of 2 km/hr and 
24 km/hr. The acceptance criteria presented in Table F-1 of this 
subpart is based on the relative aspiration between the candidate 
sampler and federal reference method sampler.
    (3) Static 2.5-micron fractionator test. The static 2.5-micron 
fractionator test determines the effectiveness of the candidate 
fractionator under static conditions for aerosols of the size and type 
specified in Table F-2 of this subpart (under the heading, ``Static 
Fractionator Test'). The candidate sampler must meet the acceptance 
criteria presented in Table F-1 of this subpart.
    (4) Loading test. (i) The loading test is used to ensure that the 
performance of a candidate sampler is not significantly affected by the 
amount of material deposited on its interior surfaces between periodic 
cleaning. This test is divided into two distinct experiments:
    (A) A mandatory demonstration of no significant performance shift 
over a 24-hour time period; and
    (B) An optional demonstration of no significant performance shift 
over an extended time period for approval of a cleaning interval 
greater than 24 hours.
    (ii) In the initial evaluation, the candidate sampler is operated 
in test environment equivalent to sampling 150 g/m3 
coarse mode aerosol over a 24-hour time period. The candidate's 
performance must then be evaluated by Sec. 53.62 (full wind tunnel 
evaluation) with the exception being a modification to the fractionator 
alone, in which case the performance may be optionally evaluated by 
Sec. 53.64 (static fractionator test). If the results of the 
appropriate test meet the criteria presented in Table F1 of this 
subpart, then the candidate sampler passes the loading test under the 
condition that it be cleaned after each 24-hour use.
    (iii) An extended loading test may be performed to gain approval of 
a longer time period between periodic cleaning of the fractionator. In 
this extended loading test, the candidate sampler is loaded with a mass 
equivalent to operating the unit in an environment of 150 g/
m3 coarse mode aerosol over the time period proposed by the 
manufacturer between cleaning. Reevaluation of the expected mass 
collected is performed via the wind tunnel test or the static 2.5-
micron fractionator test, depending upon which test was used for the 
initial evaluation. If the results meet the criteria presented in Table 
F-1 of this subpart, then the candidate sampler passes the loading test 
under the condition that it be cleaned at least as often as the 
proposed cleaning frequency.
    (5) Volatility test. The volatility test challenges the candidate 
sampler with a polydisperse, semi-volatile liquid aerosol. This aerosol 
is simultaneously sampled by the candidate method sampler and a 
reference method sampler for a specified time period. Clean air is then 
passed through the samplers for an additional time period. The filters 
are then reweighed to determine residual mass of the collected aerosol. 
The candidate sampler passes the volatility test if the candidate 
method meets the specifications presented in Table F-1 of this subpart.
    (g) Test data. All test data and other documentation obtained from 
or pertinent to these tests shall be identified, dated, signed by the 
analyst performing the test, and submitted to EPA as part of the 
equivalent method application. Schematic drawings of each particle 
delivery system and other information showing complete procedural 
details of the test atmosphere generation, verification, and delivery 
techniques for each test performed shall be submitted to EPA. All 
pertinent calculations shall be clearly presented. In addition, 
manufacturers are required to complete and submit the designation 
testing checklist presented in Figure 2 of this subpart as part of the 
application.


Sec. 53.61  Test conditions.

    (a) Sampler surface preparation. Internal surfaces of the candidate 
sampler shall be cleaned and dried prior to performing any Class II 
sampler test in this Subpart. The internal collection surfaces of the 
sampler shall then be prepared in strict accordance with the operating 
instructions specified in the sampler's operating manual referred to in 
Sec. 53.4(b)(3).
    (b) Sampler setup. Set up and start up of all test samplers shall 
be in strict accordance with the operating instructions specified in 
the manual referred to in Sec. 53.4(b)(3), unless otherwise specified 
within this subpart.
    (c) Sampler adjustments. Once the test sampler or samplers have 
been set up and the performance tests started, manual adjustment shall 
be permitted only between test points for all applicable tests. Manual 
adjustments and any periodic maintenance shall be limited to only those 
procedures prescribed in the manual referred to in Sec. 53.4(b)(3). The 
submitted records shall clearly indicate when any manual adjustment or 
periodic maintenance was made and shall describe the operations 
performed.
    (d) Sampler malfunctions. If a test sampler malfunctions during any 
of the applicable tests that test run shall be repeated. A detailed 
explanation of all malfunctions and the remedial actions taken shall be 
submitted as part of the equivalent method application.
    (e) Particle concentration measurements. All measurements of 
particle concentration must be made such that the relative error in 
measurement is less than 5.0 percent. Relative error is defined as (s x 
100 percent)/(X), where s is the sample standard deviation of the 
particle concentration detector, X is the measured concentration, and 
the units of s and X are identical.
    (f) Operation of test measurement equipment. All test measurement 
equipment shall be setup, calibrated, and maintained according to the 
manufacturer's instructions by qualified personnel only. All 
appropriate calibration information and manuals for this equipment 
shall be kept on file.
    (g) Aerosol generation parameters. This section prescribes 
conventions regarding aerosol generation techniques. Size-selective 
performance tests outlined in Secs. 53.62, 53.63, 53.64, and 53.65 
specify the use of the vibrating orifice aerosol generator (VOAG) for 
the production of test aerosols. The volatility test in Sec. 53.66 
specifies the use of a nebulized polydisperse aerosol.
    (1) Particle aerodynamic diameter. The VOAG produces near-
monodisperse droplets through the controlled breakup of a liquid jet. 
When the liquid solution consists of a non-volatile solute dissolved in 
a volatile solvent, the droplets dry to form particles of near-
monodisperse size.
    (i) The physical diameter of a generated spherical particle can be 
calculated from the operating parameters of the VOAG as:

[GRAPHIC] [TIFF OMITTED] TP13DE96.079


where:

Dp=particle physical diameter, m
Q=liquid volumetric flow rate, m3/sec

[[Page 65829]]

Cvol=volume concentration (particle volume produced per drop 
volume), dimensionless
f=frequency of applied vibrational signal, sec-1.
    (ii) A given particle's aerodynamic behavior is a function of its 
physical particle size, particle shape, and density. Aerodynamic 
diameter is defined as the diameter of a unit density 
(o=1 g/m3) sphere having the same settling velocity 
as the particle under consideration. For converting a spherical 
particle of known density to aerodynamic diameter, the governing 
relationship is:

[GRAPHIC] [TIFF OMITTED] TP13DE96.080


where

Dae=particle aerodynamic diameter, m
p=particle density, g/cm3
o=aerodynamic particle density=1 g/m3
CDp=Cunningham's slip correction factor for physical particle 
diameter, dimensionless
CDae=Cunningham's slip correction factor for aerodynamic particle 
diameter, dimensionless.

    (iii) At room temperature and standard pressure, the Cunningham's 
slip correction factor is solely a function of particle diameter:

[GRAPHIC] [TIFF OMITTED] TP13DE96.081


or
[GRAPHIC] [TIFF OMITTED] TP13DE96.082


    (iv) Since the slip correction factor is itself a function of 
particle diameter, the aerodynamic diameter cannot be solved directly 
but can be determined by iteration.
    (2) Solid particle generation. As specified in Table F-2 of this 
subpart, all solid particle tests in this subpart shall be conducted 
using particles composed of ammonium fluorescein. For use in the VOAG, 
liquid solutions of known volumetric concentration can be prepared by 
diluting fluorescein powder (C20H12O5, FW=332.31, CAS 
2321-07-5) with aqueous ammonia. Guidelines for preparation of 
fluorescein solutions of the desired volume concentration (Cvol) 
are presented by Vanderpool and Rubow (1988) (Reference 2 in Appendix A 
of this subpart). For purposes of converting particle physical diameter 
to aerodynamic diameter, an ammonium fluorescein density of 1.35 g/
cm3 shall be used. Mass deposits of ammonium fluorescein shall be 
extracted and analyzed using solutions of 0.01 N ammonium hydroxide.
    (3) Liquid particle generation. (i) Oleic acid particles. (A) Tests 
prescribed in Sec. 53.63 for inlet aspiration require the use of liquid 
particle tests composed of oleic acid tagged with uranine to enable 
subsequent fluorometric quantitation of collected aerosol mass 
deposits. Oleic acid (C18H34O2, FW=282.47, CAS 112-80-1) 
has a density of 0.8935 g/cm3. Because the viscosity of oleic acid 
is relatively high, significant errors can occur when dispensing oleic 
acid using volumetric pipettes. For this reason, it is recommended that 
oleic acid solutions be prepared by quantifying dispensed oleic acid 
gravimetrically. The volume of oleic acid dispensed can then be 
calculated simply by dividing the dispensed mass by the oleic acid 
density.
    (B) Oleic acid solutions tagged with uranine shall be prepared as 
follows. A known mass of oleic acid shall first be diluted using 
absolute ethanol. The desired mass of the uranine tag should then be 
diluted in a separate container using absolute ethanol. Uranine 
(C20H10O5Na2, FW=376.3, CAS 518-47-8) is the 
disodium salt of fluorescein and has a density of 1.53 g/cm3. In 
preparing uranine tagged oleic acid particles, the uranine content 
shall not exceed 20 percent on a mass basis. Once both oleic acid and 
uranine solutions are properly prepared, they can then be combined and 
diluted to final volume using absolute ethanol.
    (C) Calculation of the physical diameter of the particles produced 
by the VOAG requires knowledge of the liquid solution's volume 
concentration (Cvol). Because uranine is essentially insoluble in 
oleic acid, the total particle volume is the sum of the oleic acid 
volume and the uranine volume. The volume concentration of the liquid 
solution shall be calculated as:

[GRAPHIC] [TIFF OMITTED] TP13DE96.083


where:

Vu=uranine volume, ml
Voleic=oleic acid volume, ml
Vsol=total solution volume, ml
Mu=uranine mass, g
u=uranine density, g/cm3
Moleic=oleic acid mass, g
oleic=oleic acid density, g/cm3

    (D) For purposes of converting the particles' physical diameter to 
aerodynamic diameter, the density of the generated particles shall be 
calculated as:

[GRAPHIC] [TIFF OMITTED] TP13DE96.084



[[Page 65830]]


    (E) Mass deposits of oleic acid shall be extracted and analyzed 
using solutions of 0.01 N sodium hydroxide.
    (ii) Glycerol. Tests prescribed in Sec. 53.66 for conducting 
volatility tests shall be conducted using ACS reagent grade glycerol 
(C3H8O3, FW=92.09, CAS 56-81-5) with a minimum purity of 
99.5 percent.


Sec. 53.62  Test Procedure: Full wind tunnel test.

    (a) Overview. The full wind tunnel test evaluates the effectiveness 
of the candidate sampler at 2 km/hr and 24 km/hr for aerosols of the 
size and type specified in Table F-2 of this subpart (under the 
heading, ``Full Wind Tunnel Test''). For each wind speed, a smooth 
curve is fit to the effectiveness data and corrected for the presence 
of multiplets in the wind tunnel calibration aerosol. The cutpoint 
diameter (Dp50) at each wind speed is then be determined from the 
corrected effectiveness curves. The two resultant penetration curves 
are then numerically integrated with three idealized ambient particle 
size distributions to provide an estimate of measured mass 
concentration. Critical parameters for these idealized distributions 
are presented in Table F-3 of this subpart.
    (b) Technical definitions. Effectiveness is the ratio (expressed as 
a percentage) of the mass concentration of particles of a specific size 
reaching the sampler filter or filters to the mass concentration of 
particles of the same size approaching the sampler.
    (c) Facilities and equipment required. (1) Wind tunnel. The 
particle delivery system shall consist of a blower system and a wind 
tunnel having a test section of sufficiently large cross-sectional area 
such that the test sampler, or portion thereof, as installed in the 
test section for testing, blocks no more than 15 percent of the test 
section area. The wind tunnel blower system must be capable of 
maintaining uniform wind speeds at the 2 km/hr and 24 km/hr.
    (2) Aerosol generation system. A vibrating orifice aerosol 
generator shall be used to produce monodisperse solid particles of 
ammonium fluorescein with equivalent aerodynamic diameters as specified 
in Table F-2 of this subpart. The geometric standard deviation for each 
particle size and type generated shall not exceed 1.1 (for primary 
particles) and the proportion of multiplets (doublets and triplets) in 
all test particle atmosphere shall not exceed 10 percent. The 
aerodynamic particle diameter, as established by the operating 
parameters of the vibrating orifice aerosol generator, shall be within 
the tolerance specified in Table F-2 of this subpart.
    (3) Particle size verification equipment. The size of the test 
particles shall be verified during this test by use of a suitable 
instrument (e.g., scanning electron microscope, optical particle 
counter, time-of-flight apparatus). The instrument must be capable of 
measuring solid and liquid test particles with a size resolution of 0.1 
m or less. The accuracy of the particle size verification 
technique shall be 0.15 m or better.
    (4) Wind speed measurement. The wind speed in the wind tunnel shall 
be determined during the tests using an appropriate technique capable 
of a precision of 5 percent or better (e.g., hot-wire anemometry). For 
the wind speeds specified in Table F-2 of this subpart, the wind speed 
and turbulence intensity (longitudinal component and macro scale) shall 
be measured at a minimum of 12 test points in a cross-sectional area of 
the test section of the wind tunnel. The mean wind speed in the test 
section must be within 10 percent of the value specified in 
Table F-2 of this subpart, and the variation at any test point in the 
test section may not exceed 10 percent of the measured mean.
    (5) Aerosol rake. The cross-sectional uniformity of the particle 
concentration in the sampling zone of the test section shall be 
established during the tests using an array of isokinetic samplers, 
referred to as a rake. Not less than five evenly spaced isokinetic 
samplers shall be used to determine the particle concentration spatial 
uniformity in the sampling zone. The sampling zone shall be a 
rectangular area having a horizontal dimension not less than 1.2 times 
the width of the test sampler at its inlet opening and a vertical 
dimension not less than 25 centimeters.
    (6) Total aerosol isokinetic sampler. A single isokinetic sampler 
may be used in place of the array of isokinetic samplers for the 
determination of particle mass concentration used in the calculation of 
sampling effectiveness of the test sampler in Sec. 53.62(e)(5). In this 
case, the array of isokinetic samplers must be used to demonstrate 
particle concentration uniformity prior to the replicate measurements 
of sampling effectiveness.
    (7) Fluorometer. A series of calibration standards shall be 
prepared to encompass the minimum and maximum concentrations measured 
during size-selective tests. Prior to each calibration and measurement, 
the fluorometer shall be zeroed using an aliquot of the same solvent 
used for extracting aerosol mass deposits.
    (8) Sampler flow rate measurements. All flow rate measurements used 
to calculate the test atmosphere concentrations and the test results 
must be accurate to within 2 percent, referenced to a NIST-
traceable primary standard. Any necessary flow rate measurement 
corrections shall be clearly documented. All flow rate measurements 
shall be performed and reported in actual volumetric units.
    (d) Test procedures. (1) Establish and verify wind speed.
    (i) Establish a wind speed specified in Table F-2 of this subpart.
    (ii) Measure the wind speed and turbulence intensity (longitudinal 
component and macro scale) at a minimum of 12 test points in a cross-
sectional area of the test section of the wind tunnel using a device as 
described in Sec. 53.62(c)(4).
    (iii) Verify that the mean wind speed in the test section of the 
wind tunnel during the tests is within 10 percent of the value 
specified in Table F-2 of this subpart. The wind speed measured at any 
test point in the test section shall not differ by more than 10 percent 
from the mean wind speed in the test section.
    (2) Generate aerosol. Generate particles of a size and type 
specified in Table F-2 of this subpart using a vibrating orifice 
aerosol generator. Check for the presence of satellites and adjust the 
generator as necessary. Calculate the physical particle size using the 
operating parameters of the vibrating orifice aerosol generator and 
record. Determine the particle's aerodynamic diameter from the 
calculated physical diameter and the known density of the generated 
particle. The calculated aerodynamic diameter must be within the 
tolerance specified in Table F-2 of this subpart.
    (3) Introduce particles into the wind tunnel. Introduce the 
generated particles into the wind tunnel and allow the particle 
concentration to stabilize.
    (4) Verify the quality of the test aerosol. (i) Extract a 
representative sample of the aerosol from the sampling test zone and 
measure the size distribution of the collected particles using an 
appropriate sizing technique. If the measurement instrumentation does 
not provide a direct measure of aerodynamic diameter, calculate the 
geometric mean aerodynamic diameter using the known density of the 
particle type in conjunction with the measured mean physical diameter. 
The determined mean aerodynamic diameter of the test aerosol must be 
within 0.15 m of the aerodynamic diameter calculated from the 
operating parameters of the vibrating orifice aerosol generator. The 
geometric

[[Page 65831]]

standard deviation of the primary particles must not exceed 1.1.
    (ii) Determine the population of multiplets in the collected 
sample. The multiplet population of the particle test atmosphere must 
not exceed 10 percent of the total particle population.
    (5) Aerosol uniformity and concentration measurement. (i) Install 
an array of five or more evenly spaced isokinetic samplers in the 
sampling zone [Sec. 53.62(c)(5)]. Collect particles on appropriate 
filters over a time period such that the relative error of the measured 
particle concentration is less than 5.0 percent.
    (ii) Determine the quantity of material collected with each 
isokinetic sampler in the array using a calibrated fluorometer. 
Calculate and record the mass concentration for each isokinetic sampler 
as:

[GRAPHIC] [TIFF OMITTED] TP13DE96.085


Where

i=replicate number
j=isokinetic sampler number
Miso=mass of material collected with the isokinetic sampler
Q=isokinetic sampler volumetric flow rate
t=sampling time.

    (iii) Calculate and record the mean mass concentration as:
    [GRAPHIC] [TIFF OMITTED] TP13DE96.086
    

Where

I=replicate number
j=isokinetic sampler number
n=total number of isokinetic samplers.

    (iv) Precision calculation. (A) Calculate the coefficient of 
variation of the mass concentration measurements as:

[GRAPHIC] [TIFF OMITTED] TP13DE96.087


Where

i=replicate number
j=isokinetic sampler number
n=total number of isokinetic samplers.

    (B) If the value of CViso(I) for any replicate exceeds 10 percent, 
the particle concentration uniformity is unacceptable and step 5 must 
be repeated. If adjustment of the vibrating orifice aerosol generator 
or changes in the particle delivery system are necessary to achieve 
uniformity, steps 2 through 5 must be repeated. When an acceptable 
aerosol spatial uniformity is achieved, remove the array of isokinetic 
samplers from the wind tunnel.
    (6) Alternative measure of wind tunnel total concentration. If a 
single isokinetic sampler is used to determine the mean aerosol 
concentration in the wind tunnel, install the sampler in the wind 
tunnel with the sampler nozzle centered in the sampling zone 
[Sec. 53.62(c)(6)].
    (i) Collect particles on an appropriate filter over a time period 
such that the relative error of the measured concentration is less than 
5.0 percent.
    (ii) Determine the quantity of material collected with the 
isokinetic sampler using a calibrated fluorometer.
    (iii) Calculate and record the mass concentration as Ciso(I) 
as in Sec. 53.62(e)(4)(ii).
    (iv) Remove the isokinetic sampler from the wind tunnel.
    (7) Measure the aerosol with the candidate sampler. (i) Install the 
test sampler (or portion thereof) in the wind tunnel with the sampler 
inlet opening centered in the sampling zone. To meet the maximum 
blockage limit of Sec. 53.62(c)(1) or for convenience, part of the test 
sampler may be positioned external to the wind tunnel provided that 
neither the geometry of the sampler nor the length of any connecting 
tube or pipe is altered. Collect particles for a time period such that 
the relative error of the measured concentration is less than 5.0 
percent.
    (ii) Remove the test sampler from the wind tunnel.
    (iii) Determine the quantity of material collected with the test 
sampler using a calibrated fluorometer. Calculate and record the mass 
concentration for each replicate as:

[GRAPHIC] [TIFF OMITTED] TP13DE96.088


Where

i=replicate number
Mcand=mass of material collected with the candidate sampler
Q=candidate sampler volumetric flow rate
t=sampling time.

    (iv) (A) Calculate and record the sampling effectiveness of the 
candidate sampler as:
[GRAPHIC] [TIFF OMITTED] TP13DE96.089


Where:

 i = replicate number.

    (B) If a single isokinetic sampler is used for the determination of 
particle mass concentration, replace Ciso(I) with Ciso.
    (8) Obtain a minimum of three replicate measures of sampling 
effectiveness and calculate the mean sampling effectiveness. (i) Repeat 
steps in paragraphs (d) (5) through (7) of this section, as 
appropriate, to obtain a

[[Page 65832]]

minimum of three valid replicate measurements of sampling 
effectiveness.
    (ii) Calculate and record the average sampling effectiveness of the 
test sampler for the particle size and type as:

[GRAPHIC] [TIFF OMITTED] TP13DE96.090


Where:

i = replicate number
n = number of replicates.

    (iii) Sampling effectiveness precision. (A) Calculate and record 
the coefficient of variation for the replicate sampling effectiveness 
measurements of the test sampler as:

[GRAPHIC] [TIFF OMITTED] TP13DE96.091


Where:

i = replicate number
n = number of replicates.

    (B) If the value of CVE exceeds 10 percent, the test run 
(steps in paragraphs (d)(2) through (8) of this section) must be 
repeated until an acceptable value is obtained.
    (9) Repeat for each particle size and type for the selected wind 
speed. Repeat steps in paragraphs (d)(2) through (8) of this section 
until the sampling effectiveness has been measured for all particle 
sizes and types specified in Table F-2 of this subpart.
    (10) Repeat for each wind speed. Repeat steps in paragraphs (d)(1) 
through 9 of this section until tests have been successfully conducted 
for both wind speeds of 2 km/hr and 24 km/hr.
    (e) Calculations. (1) Graphical treatment of effectiveness data. 
For each wind speed given in Table F-2 of this subpart, plot the 
particle sampling effectiveness of the test sampler as a function of 
aerodynamic particle diameter (Dae) on semi-logarithmic graph 
paper where the aerodynamic particle diameter is the particle size 
established by the parameters of the VOAG in conjunction with the known 
particle density. Construct a best-fit, smooth curve through the data 
by extrapolating the sampling effectiveness curve through 100 percent 
at an aerodynamic particle size of 0.5 m and 0 percent at an 
aerodynamic particle size of 10 m. Correction for the presence 
of multiplets shall be performed using the techniques presented by 
Marple, et al (1987).
    (2) Cutpoint determination. For each wind speed determine the 
sampler Dp50 cutpoint defined as the aerodynamic particle size 
corresponding to 50 percent effectiveness from the multiplet corrected 
smooth curve.
    (3) Expected mass concentration calculation. For each wind speed, 
calculate the estimated mass concentration measurement for the test 
sampler under each particle size distribution (Tables F-4, F-5, and F-6 
of this subpart) and compare it to the mass concentration predicted for 
the reference sampler, as follows:
    (i) Determine the value of corrected effectiveness using the best-
fit curve at each of the particle sizes specified in the first column 
of Table F-4 of this subpart. Record each corrected effectiveness value 
as a decimal between 0 and 1 in column 2 of Table F-4 of this subpart.
    (ii) Calculate the interval estimated mass concentration 
measurement by multiplying the values of corrected effectiveness in 
column 2 by the interval mass concentration values in column 3 and 
enter the products in column 4 of Table F-4 of this subpart.
    (iii) Calculate the estimated mass concentration measurement by 
summing the values in column 4 and entering the total as the estimated 
mass concentration measurement for the test sampler at the bottom of 
column 4 of Table F-4 of this subpart.
    (iv) Calculate the estimated mass concentration ratio between the 
candidate method and the reference method as:

[GRAPHIC] [TIFF OMITTED] TP13DE96.092


Where:

Ccand(est)=estimated mass concentration measurement for the test 
sampler, g/m3; and
Cref(est)=estimated mass concentration measurement for the 
reference sampler, g/m3 (calculated for the reference 
sampler and specified at the bottom of column 7 of Table F-4 of this 
subpart).

    (v) Repeat steps in paragraphs (e) (1) through (3) of this section 
for Tables F-5 and F-6 of this subpart.
    (f) Evaluation of test results. The candidate method passes the 
wind tunnel effectiveness test if the Rc value for each wind speed 
meets the specification in Table F-1 of this subpart for each of the 
three particle size distributions.


Sec. 53.63  Test Procedure: Wind tunnel inlet aspiration test.

    (a) Overview. This test applies to a candidate sampler which 
differs from the reference method sampler only with respect to the 
design of the inlet. The purpose of this test is to compare the 
aspiration of a Class II candidate sampler to that of the reference 
method sampler's inlet. This wind tunnel test uses a 3.5-micron liquid 
aerosol in conjunction with wind speeds of 2 km/hr and 24 km/hr. The 
test atmosphere concentration is alternately measured with the 
candidate sampler and a reference method device, both of which are 
operated without the 2.5-micron fractionation device installed. The 
test conditions are summarized in Table F-2 of this subpart (under the 
heading of wind tunnel inlet aspiration test). The candidate sampler 
must meet or exceed the acceptance criteria given in Table F-1 of this 
subpart.
    (b) Technical definition. Relative aspiration is the ratio 
(expressed as a percentage) of the aerosol mass concentration measured 
by the candidate sampler to that measured by a reference method 
sampler.
    (c) Facilities and equipment required. The facilities and equipment 
are identical to those required for the full wind tunnel test 
[Sec. 53.62(c)].
    (d) Test procedure. (1) Establish the wind tunnel test atmosphere. 
Follow the procedures in Sec. 53.62(e)(1) through Sec. 53.62(e)(4) to 
establish a test atmosphere for one of the two wind speeds specified in 
Table F-2 of this subpart.
    (2) Measure the aerosol concentration with the reference sampler. 
(i) Install the reference sampler (or portion thereof) in the wind 
tunnel with the sampler inlet opening centered in the sampling zone. To 
meet the maximum blockage limit of Sec. 53.62(c)(1) or for convenience, 
part of the test sampler may be positioned external to the wind tunnel 
provided

[[Page 65833]]

that neither the geometry of the sampler nor the length of any 
connecting tube or pipe is altered. Collect particles for a time period 
such that the relative error of the measured concentration [as defined 
in Sec. 53.61(5)] is less than 5.0 percent.
    (ii) Determine the quantity of material collected with the 
reference method sampler using a calibrated fluorometer. Calculate and 
record the mass concentration as:

[GRAPHIC] [TIFF OMITTED] TP13DE96.093


Where:

i=replicate number
Mref=mass of material collected with the reference method sampler
Q=reference method sampler volumetric flowrate
t=sampling time.

    (iii) Remove the reference method sampler from the tunnel.
    (3) Measure the aerosol concentration with the candidate sampler. 
(i) Install the candidate sampler (or portion thereof) in the wind 
tunnel with the sampler inlet centered in the sampling zone. To meet 
the maximum blockage limit of Sec. 53.62(c)(1) or for convenience, part 
of the test sampler may be positioned external to the wind tunnel 
provided that neither the geometry of the sampler nor the length of any 
connecting tube or pipe is altered. Collect particles for a time period 
such that the relative error of the measured concentration is less than 
5.0 percent.
    (ii) Determine the quantity of material collected with the 
candidate sampler using a calibrated fluorometer. Calculate and record 
the mass concentration as:

[GRAPHIC] [TIFF OMITTED] TP13DE96.094


Where:
i=replicate number
Mcand=mass of material collected with the candidate sampler
Q=candidate sampler volumetric flow rate
t=sampling time.

    (iii) Remove the candidate sampler from the wind tunnel.
    (4) Repeat steps in paragraphs (d) (2) and (3) of this section. 
Alternately measure the tunnel concentration with the reference sampler 
and the candidate sampler until four reference sampler and five 
candidate sampler measurements of the wind tunnel concentration are 
obtained.
    (e) Calculations. (1) Aspiration ratio. Calculate aspiration ratio 
for each candidate sampler run as:

[GRAPHIC] [TIFF OMITTED] TP13DE96.095


where

i=replicate number.

    (2) Precision of aspiration ratio. Calculate the precision of 
aspiration ratio measurements as the coefficient of variation for each 
aspiration ratio:

[GRAPHIC] [TIFF OMITTED] TP13DE96.096


where:

i=replicate number
n=total number of measurements of aspiration ratio.
    (f) Evaluation of test results. The candidate method passes the 
inlet aspiration test if all values of A and CVA meet the 
acceptance criteria specified in Table F-1 of this subpart.


Sec. 53.64  Test Procedure: Static fractionator test.

    (a) Overview. This test applies only to those candidate methods in 
which the sole deviation from the reference method is in the design of 
the 2.5-micron fractionation device. The purpose of this test is to 
ensure that the fractionation characteristics of the candidate 
fractionator are acceptably similar to that of the reference method 
sampler. It is recognized that various methodologies exist for 
quantifying fractionator effectiveness. The following commonly-employed 
techniques are provided for purposes of guidance. Other methodologies 
for determining sampler effectiveness may be used contingent upon prior 
approval by the Agency.
    (1) Wash-off method. Effectiveness is determined by measuring the 
aerosol mass deposited in the candidate sampler's afterfilter versus 
the aerosol mass deposited in the fractionator. The material deposited 
in the fractionator is recovered by washing its internal surfaces. For 
these wash-off tests, a fluorometer must be used to quantitate the 
aerosol concentration. Note that if this technique is chosen, the 
candidate must be reloaded with coarse aerosol prior to each test point 
when reevaluating the curve as specified in the loading test.
    (2) Static chamber method. Effectiveness is determined by measuring 
the aerosol mass concentration sampled by the candidate's sampler's 
afterfilter versus that which exists in a static chamber. A calibrated 
fluorometer must be used to quantify the collected aerosol deposits. 
The aerosol concentration is calculated as the measured aerosol mass 
divided by the sampled air volume.
    (3) Divided flow method. Effectiveness is determined by comparing 
the aerosol concentration upstream of the candidate sampler's 
fractionator versus that concentration which exists downstream of the 
candidate fractionator. These tests may utilize either fluorometry or a 
real-time aerosol measuring device to determine the aerosol 
concentration.
    (b) Technical definition. Effectiveness under static conditions is 
the ratio (expressed as a percentage) of the mass concentration of 
particles of a given size reaching the sampler filter to the mass 
concentration of particles of the same size approaching the sampler.
    (c) Facilities and equipment required.

[[Page 65834]]

    (1) Aerosol generation. Methods for generating aerosols shall be 
identical to those prescribed in Sec. 53.62(c)(2).
    (2) Particle delivery system. Acceptable apparatus for delivering 
the generated aerosols to the candidate fractionator is dependent on 
the effectiveness measurement methodology and are defined as follows:
    (i) Wash-off test apparatus. The aerosol may be delivered to the 
candidate fractionator through direct piping (with or without an in-
line mixing chamber). Particle size and quality validation shall be 
conducted at the point where the fractionator attaches.
    (ii) Static chamber test apparatus. The aerosol shall be introduced 
into a chamber and sufficiently mixed such that the aerosol 
concentration within the chamber is spatially uniform. The chamber must 
be of sufficient size to house at least four total filter samplers, as 
well as the inlet of the candidate size discriminator. Particle size 
validation and quality validation shall be conducted on representative 
aerosol samples extracted from the chamber.
    (iii) Divided flow test apparatus. The apparatus shall allow the 
aerosol concentration to be measured upstream and downstream of the 
fractionator. The particles shall be delivered to the divided flow 
apparatus via a symmetrical flow path.
    (3) Particle concentration measurement.
    (i) Fluorometry. Fluorometers used for quantifying extracted 
aerosol mass deposits shall be set up, maintained, and calibrated 
according to the manufacturer's instructions. A series of calibration 
standards shall be prepared to encompass the minimum and maximum 
concentrations measured during size-selective tests. Prior to each 
calibration and measurement, the fluorometer shall be zeroed using an 
aliquot of the same solvent used for extracting aerosol mass deposits.
    (ii) Number concentration measurement. A number counting device may 
be used in conjunction with the divided flow test apparatus as 
described above. This device must have a resolution and accuracy such 
that primary particles may be distinguished from multiplets for all 
test aerosols. The measurement of number concentration shall be 
accomplished by integrating the primary particle peak.
    (d) Setup. (1) Remove the inlet from the candidate fractionator. 
All tests procedures shall be conducted with the inlet removed from the 
candidate sampler.
    (2) Surface treatment of the fractionator. Rinsing aluminum 
surfaces with alkaline solutions has been found to adversely affect 
subsequent fluorometric quantitation of aerosol mass deposits. If wash-
off tests are to be used for quantifying aerosol penetration, internal 
surfaces of the fractionator must first be plated with electroless 
nickel. Specifications for this plating are specified in MIL.C-26074 
Grade B, Class 4 (Reference 4 in appendix A of Subpart E).
    (e) Test Procedure: Wash off method. (1) Clean and dry internal 
surfaces. Thoroughly clean and dry all internal surfaces of the 
candidate particle size fractionator. The internal surfaces of the 
fractionator shall then be prepared in strict accordance with the 
operating instructions specified in the samplers operating manual. 
Note: The procedures in this paragraph must be omitted if this test is 
being used to evaluate the fractionator after being loaded as specified 
in Sec. 53.65.
    (2) Generate aerosol. Follow the procedures for aerosol generation 
prescribed in Sec. 53.62(e)(2).
    (3) Verify the quality of the test aerosol. Follow the procedures 
for verification of test aerosol size and quality prescribed in 
Sec. 53.62(e)(4).
    (4) Determine effectiveness for the particle size and type being 
produced. (i) Collect particles downstream of the fractionator on an 
appropriate filter over a time period such that the relative error of 
the measurement is less than 5.0 percent.
    (ii) Determine the quantity of material collected on the 
afterfilter of the candidate method using a calibrated fluorometer. 
Calculate and record the aerosol mass concentration for the sampler 
filter as:

[GRAPHIC] [TIFF OMITTED] TP13DE96.097


where:
i=replicate number
Mcand=mass of material collected with the candidate sampler
Q=candidate sampler volumetric flowrate
t=sampling time.

    (iii) Wash all interior surfaces upstream of the filter and 
determine the quantity of material collected using a calibrated 
fluorometer. Calculate and record the fluorometric mass concentration 
of the sampler wash as:

[GRAPHIC] [TIFF OMITTED] TP13DE96.098


where:
i=replicate number
Mwash=mass of material washed from the interior surfaces of the 
fractionator
Q=candidate sampler volumetric flowrate
t=sampling time.
    (iv) Calculate and record the sampling effectiveness of the test 
sampler for this particle size as:

[GRAPHIC] [TIFF OMITTED] TP13DE96.099


where i=replicate number.

    (v) Repeat steps in paragraphs (e)(4)(9) through (iv) of this 
section, as appropriate, to obtain a minimum of three replicate 
measurements of sampling effectiveness.
    (vi) Calculate and record the average sampling effectiveness of the 
test sampler as:
[GRAPHIC] [TIFF OMITTED] TP13DE96.100


where:
i=replicate number
n=number of replicates.
    (vii) (A) Calculate and record the coefficient of variation for the 
replicate sampling effectiveness measurements of the test sampler as:


[[Page 65835]]

[GRAPHIC] [TIFF OMITTED] TP13DE96.101



where:
i=replicate number
n=total number of measurements.
    (B) If the value of CVE exceeds 10 percent, then steps in 
paragraphs (e) (2) through (4) of this section must be repeated. Note 
that the sampler must be loaded according to the test procedures in 
Sec. 53.65 prior to retesting each point if this test is being used as 
a post-evaluation to satisfy the requirements of Sec. 53.65.
    (5) Repeat steps in paragraphs (e) (1) through (4) of this section 
for each particle size and type specified in Table F-2 of this subpart.
    (f) Test procedure: Static chamber method.
    (1) Generate aerosol. Follow the procedures for aerosol generation 
prescribed in Sec. 53.62(e)(2).
    (2) Verify the quality of the test aerosol. Follow the procedures 
for verification of test aerosol size and quality prescribed in 
Sec. 53.62(e)(4).
    (3) Introduction of particles into chamber. Introduce the particles 
into the static chamber and allow the particle concentration to 
stabilize.
    (4) Install and operate the candidate sampler and at least four 
total filters. (i) Install the fractionator and an array of four or 
more equally spaced filter samplers such that the filters surround and 
are in the same plane as the inlet of the fractionator.
    (ii) Collect particles on an appropriate filter for a time period 
such that the relative error of the measured concentration is less than 
5.0 percent.
    (5) Calculate the aerosol spatial uniformity in the chamber. (i) 
Determine the quantity of material collected with each total filter 
sampler in the array using a calibrated fluorometer. Calculate and 
record the mass concentration for each total filter sampler as:

[GRAPHIC] [TIFF OMITTED] TP13DE96.102


where:
i=replicate number
j=total filter sampler number
Mtotal=mass of material collected with the total filter sampler
Q=total filter sampler volumetric flowrate
t=sample time.

    (ii) Calculate and record the mean mass concentration as:

    [GRAPHIC] [TIFF OMITTED] TP13DE96.103
    

where:
n=total number of samplers
i=replicate number
j=filter sampler number.

    (iii) (A) Calculate and record the coefficient of variation of the 
total mass concentration as:

[GRAPHIC] [TIFF OMITTED] TP13DE96.104


where:
i=replicate number
j=total filter sampler number
n=number of total filter samplers.

    (B) If the value of CVtotal exceeds 10 percent, then the 
particle concentration uniformity is unacceptable, alterations to the 
static chamber test apparatus must be made, and steps in paragraphs (f) 
(1) through (5) of this section must be repeated.
    (6) Calculate the effectiveness of the candidate sampler. (i) 
Determine the quantity of material collected on the candidate sampler's 
afterfilter using a calibrated fluorometer. Calculate and record the 
mass concentration for the candidate sampler as:

[GRAPHIC] [TIFF OMITTED] TP13DE96.105


where:
i=replicate number
Mcand=mass of material collected with the candidate sampler
Q=candidate sampler volumetric flowrate
t=sample time.

    (ii) Calculate and record the sampling effectiveness of the 
candidate sampler as:

[GRAPHIC] [TIFF OMITTED] TP13DE96.106


where i=replicate number.

    (iii) Repeat step in paragraph (f)(4) through (6) of this section, 
as appropriate, to obtain a minimum of three replicate measurements of 
sampling effectiveness.
    (iv) Calculate and record the average sampling effectiveness of the 
test sampler as:

[GRAPHIC] [TIFF OMITTED] TP13DE96.107


where i=replicate number.

    (v)(A) Calculate and record the coefficient of variation for the 
replicate sampling effectiveness measurements of the test sampler as:


[[Page 65836]]

[GRAPHIC] [TIFF OMITTED] TP13DE96.108



where:
i = replicate number
n = number of measurements of effectiveness.

    (B) If the value of CVE exceeds 10 percent, then the test run 
(steps in paragraphs (f) (2) through (6) of this section).
    (7) Repeat steps in paragraphs (f) (1) through (6) of this section 
for each particle size and type specified in Table F-2 of this subpart.
    (g) Test procedure: Divided flow method.--(1) Generate calibration 
aerosol. Follow the procedures for aerosol generation prescribed in 
Sec. 53.62(e)(2).
    (2) Verify the quality of the calibration aerosol. Follow the 
procedures for verification of calibration aerosol size and quality 
prescribed in Sec. 53.62(e)(4).
    (3) Introduce the calibration aerosol into the static chamber and 
allow the particle concentration to stabilize.
    (4) Validate that transport is equal for the divided flow option.
    (i) With fluorometry (this applies only if fluorometry is used for 
detection of particles):
    (A) Install a total filter on each leg of the divided flow 
apparatus.
    (B) Collect particles simultaneously through both legs at 16.7 aLpm 
onto an appropriate filter for a time period such that the relative 
error of the measured concentration is less than 5.0 percent.
    (C) Determine the quantity of material collected on each filter 
using a calibrated fluorometer. Calculate and record the mass 
concentration measured in each leg as:

[GRAPHIC] [TIFF OMITTED] TP13DE96.109


where:
i = replicate number
M = mass of material collected with the total filter
Q = candidate sampler volumetric flowrate.

    (D) Repeat steps in paragraphs (g)(4)(i) (A) through (C) of this 
section at until a minimum of three replicate measurements are 
performed.
    (ii) With a number counting device such as an aerosol detector:
    (A) Remove all flow obstructions from the flow paths of the two 
legs.
    (B) Quantify the aerosol concentration of the primary particles in 
each leg of the apparatus.
    (C) Repeat steps in paragraphs (g)(4)(i) (A) through (B) of this 
section at until a minimum of three replicate measurements are 
performed.
    (iii) (A) Calculate the mean concentration and coefficient of 
variation as:

[GRAPHIC] [TIFF OMITTED] TP13DE96.110


[GRAPHIC] [TIFF OMITTED] TP13DE96.111


where:
i = replicate number
n = number of replicates.

    (B) If the coefficient of variation is not less than 10 percent, 
then adjustments may be made in the setup, and this step must be 
repeated.
    (5) Determine the sampling effectiveness of the test sampler with 
the inlet removed by one of the following procedures. (i) With 
fluorometry as a detector:
    (A) Install the particle size fractionator. Install a filter 
downstream of one leg and a total filter on the bypass leg of the flow 
dividing apparatus.
    (B) Collect particles simultaneously through both legs at 16.7 aLpm 
onto appropriate filters for a time period such that the relative error 
of the measured concentration is less than 5.0 percent.
    (C) Determine the quantity of material collected on each filter 
using a calibrated fluorometer. Calculate and record the mass 
concentration measured by the total filter and that measured after 
penetrating through the candidate fractionator as follows:

[GRAPHIC] [TIFF OMITTED] TP13DE96.112


[GRAPHIC] [TIFF OMITTED] TP13DE96.113


where i= replicate number.
    (ii) With a number counting device as a detector:
    (A) Install the particle size fractionator into one of the legs of 
the divided flow apparatus.
    (B) Quantify and record the aerosol number concentration of the 
primary particles passing through the fractionator as Ccand(I).
    (C) Divert the flow from the leg containing the candidate 
fractionator to the bypass leg. Allow sufficient time for the aerosol 
concentration to stabilize.
    (D) Quantify and record the aerosol number concentration of the 
primary particles passing through the bypass leg as Ctotal(I).
    (iii) Calculate and record sampling effectiveness of the candidate 
sampler as:

[GRAPHIC] [TIFF OMITTED] TP13DE96.114


where i = replicate number.

    (6) Repeat step in paragraph (g)(5) of this section, as 
appropriate, to obtain a minimum of three replicate measurements of 
sampling effectiveness.
    (7) Calculate the mean and CV for replicate measurements.
    (i) Calculate and record the mean sampling effectiveness of the 
candidate sampler as:


[[Page 65837]]

[GRAPHIC] [TIFF OMITTED] TP13DE96.115



Where i=replicate number.

    (ii)(A) Calculate and record the coefficient of variation for the 
replicate sampling effectiveness measurements of the candidate sampler 
as:

[GRAPHIC] [TIFF OMITTED] TP13DE96.116


Where:
i=replicate number
n=number of replicates.

    (B) If the coefficient of variation is not less than 10 percent, 
then the test run must be repeated (steps in paragraphs (g) (1) through 
(7) of this section).
    (8) Repeat steps in paragraphs (g) (1) through (7) of this section 
for each particle size and type specified in Table F-2 of this subpart.
    (h) Calculations. (1) Treatment of multiplets. For all measurements 
made by fluorometric analysis, data shall be corrected for the presence 
of multiplets as described in Sec. 53.62(f)(1). Data collected using a 
real-time device with sufficient resolution to discriminate primary 
particles from multiplets will not require multiplet correction.
    (2) Cutpoint determination. For each wind speed determine the 
sampler Dp50 cutpoint defined as the aerodynamic particle size 
corresponding to 50 percent effectiveness from the multiplet corrected 
smooth curve.
    (3) Graphical analysis and numerical integration with ambient 
distributions. Follow the steps outlined in Sec. 53.62(f)(3) through 
Sec. 53.62(f)(4) to calculate the estimated concentration measurement 
ratio between the candidate sampler and a reference method sampler.
    (i) Test evaluation. The candidate method passes the static 
fractionator test if the values of Rc and Dp50 for each 
distribution meets the specifications in Table F-1 of this subpart.


Sec. 53.65  Test Procedure: Loading Test

    (a) Overview. (1) The loading tests are designed to quantify any 
appreciable changes in a candidate method's performance as a function 
of coarse aerosol collection. This test is divided into two phases:
    (i) A mandatory demonstration that the candidate method is capable 
of single-day sampling with periodic maintenance after each 24 hours of 
operation; and
    (ii) An optional demonstration that the candidate is capable of 
multi-day sampling with the periodic maintenance schedule as defined by 
the manufacturer.
    (2) In the first phase, the candidate sampler is first exposed to a 
laboratory-generated aerosol equivalent to sampling a nominal 
concentration of 150 g/m\3\ over a 24-hour time period. 
Following this initial loading, the candidate sampler's effectiveness 
as a function of particle aerodynamic diameter must then be evaluated 
using by performing the test in Sec. 53.62 (full wind tunnel test). A 
sampler which fits the category of fractionator deviation in 
Sec. 53.60(e)(2) may opt to perform the test in Sec. 53.64 (static 
fractionator test) in lieu of the full wind tunnel test. The candidate 
sampler is approved for single day sampling with maintenance after each 
24 hours of operation if the criteria in Table F-1 of this subpart are 
met for the 24-hour loading test.
    (3) In the test for extended periodic maintenance, the candidate 
sampler is exposed to a mass of coarse aerosol equivalent to sampling a 
mass concentration of 150 g/m\3\ over the time period that the 
manufacturer has specified between periodic cleaning. The candidate 
sampler's effectiveness as a function of particle aerodynamic diameter 
must then be evaluated by performing the test in Sec. 53.62 (full wind 
tunnel test). A sampler which fits the category of fractionator 
deviation in Sec. 53.60(e)(2) may opt to perform the test in Sec. 53.64 
(static fractionator test) in lieu of the full wind tunnel test. If the 
criteria presented in Table F-1 of this subpart are met for this test, 
the candidate sampler is approved for multi-day sampling with the 
periodic maintenance schedule as specified by the manufacturer. For 
example, if the candidate sampler passes the reevaluation tests 
following loading with an aerosol mass equivalent to sampling a 150 
g/m\3\ aerosol continuously for 7 days, then the sampler is 
approved for 7 day field operation before cleaning is required.
    (b) Technical Definitions. (1) Effectiveness after loading. 
Effectiveness after loading is the ratio (expressed as a percentage) of 
the mass concentration of particles of a given size reaching the 
sampler filter to the mass concentration of particles of the same size 
approaching the sampler.
    (2) Effectiveness after extended loading. Effectiveness after 
extended loading is the ratio (expressed as a percentage) of the mass 
concentration of particles of a given size reaching the sampler filter 
to the mass concentration of particles of the same size approaching the 
sampler.
    (c) Facilities and equipment required. (1) Particle delivery 
system. The particle delivery system shall consist of a static chamber 
or a low velocity wind tunnel having a sufficiently large cross-
sectional area such that the test sampler, or portion thereof, may be 
installed in the test section. At a minimum, the system must have a 
sufficiently large cross section to house the candidate sampler inlet 
as well as a collocated isokinetic nozzle for measuring total aerosol 
concentration. The mean velocity in the test section of the static 
chamber or wind tunnel shall not exceed 2 km/hr.
    (2) Aerosol generation equipment. For purposes of these tests, the 
test aerosol shall be produced from commercially available, bulk 
Arizona road dust. To provide direct interlaboratory comparability of 
sampler loading characteristics, the bulk dust is specified as 0-10 
m ATD available from Powder Technology Incorporated 
(Burnsville, MN). To efficiently deagglomerate the bulk test dust, 
either a fluidized bed aerosol generator, Wright dust feeder, or sonic 
nozzle shall be used for the aerosol generation. Other dust generators 
may be used contingent upon prior approval by the Agency.
    (3) Isokinetic sampler. Mean aerosol concentration within the 
static chamber or wind tunnel shall be established using a single 
isokinetic sampler containing a preweighed high-efficiency total 
filter.
    (d) Test Procedure: 24 hour loading test. (1) Clean the candidate 
sampler. Internal surfaces of the candidate sampler shall be thoroughly 
cleaned and dried prior to performing these tests. The internal 
fractionator surfaces shall then be prepared in strict accordance

[[Page 65838]]

with the operating instructions in the sampler's operating manual 
referred to in Sec. 53.4(b)(3). Install the candidate sampler's inlet 
and the isokinetic sampler within the test chamber or wind tunnel.
    (2) Generate a dust cloud. Generate a dust cloud composed of 
Arizona test dust and introduce the dust cloud into the chamber. Allow 
sufficient time for the particle concentration to become steady within 
the chamber.
    (3) Sample aerosol with a total filter and the candidate sampler. 
Sample the aerosol for a sufficient time to produce an equivalent time 
weighted concentration (TWC) of 3600 g hr /m\3\. For example, 
this TWC level may be achieved by sampling a 150 g/m\3\ mean 
concentration for 24 hours. Alternatively, a 900 g/m\3\ 
concentration may be sampled for a 4-hour time period to produce an 
equivalent TWC value. Following shutdown of the system, record the 
sampling time and all aerosol generation parameters.
    (4) Determine the time-weighted concentration. (i) Weigh the 
isokinetic sampler's total filter on a gravimetric balance such that 
the relative error is less than 5.0 percent. Subtract the filter's 
initial mass from the final mass to determine the collected aerosol 
mass.
    (ii)(A) Calculate and record the TWC as:

    [GRAPHIC] [TIFF OMITTED] TP13DE96.117
    

where:
M=collected aerosol mass, g
Q=candidate volumetric flowrate, m\3\/hr
t=sampling time, hr.

    (B) If the value of TWC deviates from 3600 g hr /m\3\ 
 15 percent, then the loaded mass is unacceptable and steps 
in paragraphs (d) (1) through (3) of this section must be repeated.
    (5) Determine the candidate's performance after loading. The 
candidate sampler's effectiveness as a function of particle aerodynamic 
diameter must then be evaluated using by performing the test in 
Sec. 53.62 (full wind tunnel test). A sampler which fits the category 
of fractionator deviation in Sec. 53.60(e)(2) may opt to perform the 
test in Sec. 53.64 (static fractionator test) in lieu of the full wind 
tunnel test.
    (e) Test Procedure: Extended loading test. (1) Calculate the target 
loading mass. Calculate and record the time weighted concentration of 
Arizona road dust which is equivalent to exposing the sampler in an 
environment of 150 g/m\3\ over the time specified by the 
vendor as:

[GRAPHIC] [TIFF OMITTED] TP13DE96.118


where t = the number of hours specified by the manufacturer prior to 
periodic cleaning.

    (2) Clean the candidate sampler. Internal surfaces of the candidate 
sampler shall be cleaned and dried prior to performing these loading 
tests. The internal fractionator surfaces shall then be prepared in 
strict accordance with the operating instructions specified in the 
sampler's operating manual referred to in Sec. 53.4(b)(3). Install the 
candidate sampler's inlet and the isokinetic sampler within the test 
chamber or wind tunnel.
    (3) Generate a dust cloud. Generate a dust cloud composed of 
Arizona test dust and introduce the dust cloud into the chamber. Allow 
sufficient time for the particle concentration to become steady within 
the chamber.
    (4) Sample aerosol with a total filter and the candidate sampler. 
Sample the aerosol for a time sufficient to produce an equivalent TWC 
equal to that of the target TWC 15 percent. Following 
shutdown of the system, record the sampling time and all aerosol 
generation parameters.
    (5) Determine the time weighted concentration. Weigh the isokinetic 
sampler's total filter on a gravimetric balance such that the relative 
measurement error is less than 5.0 percent. Subtract the filter's 
initial mass from the final mass to determine the collected aerosol 
mass.
    (i) (A) Calculate and record the TWC as:

    [GRAPHIC] [TIFF OMITTED] TP13DE96.119
    

    (B) If the value of TWC deviates from the target TWC  
15 percent, then the loaded mass is unacceptable and steps in 
paragraphs (e) (1) through (4) of this section must be repeated.
    (6) Determine the candidate's effectiveness after extended loading. 
The candidate sampler's effectiveness as a function of particle 
aerodynamic diameter must then be evaluated by performing the test in 
Sec. 53.62 (full wind tunnel test). A sampler which fits the category 
of fractionator deviation in Sec. 53.60(e)(2) may opt to perform the 
test in Sec. 53.64 (static fractionator test) in lieu of the full wind 
tunnel test.
    (f) Test results. (1) 24-hour test results. If the C's 
determined in the effectiveness evaluation pass the criteria 
established in Table F-1 of this subpart for the 24-hour loading test, 
then the candidate passes this test with the stipulation that the 
sampling train be cleaned after each 24 hours of operation.
    (2) Extended test results. If the C's determined in the 
effectiveness evaluation pass the criteria established in Table F-1 of 
this subpart for the extended loading test, then the candidate sampler 
passes this test with the stipulation that the sampling train be 
cleaned at least of often as the frequency tested.


Sec. 53.66  Test Procedure: Volatility test.

    (a) Overview. This test procedure is designed to ensure that the 
candidate sampler's volatility losses when sampling semi-volatile 
ambient aerosol will be comparable to that of a federal reference 
method sampler. The candidate sampler must meet or exceed the 
acceptance criteria in Table F- 1 of this subpart.
    (b) Technical definition. Residual mass (RM) is defined as the 
difference between the final filter weight following the blow-off phase 
and the initial filter weight preceding the loading phase.
    (c) Facilities and equipment required. (1) Chambers and test 
atmosphere. This test requires two chambers, one inside the other. The 
internal chamber is used to produce a well-mixed test atmosphere from 
which the sampling is performed. The air velocity in the chamber shall 
be 2.0 km/hr  10 percent, perpendicular to the sampling 
inlet. The test section shall be sufficiently large such that the 
inlet, or portion installed thereof, shall block no more than 15percent 
of the chamber cross section in the test area. At least one reference 
and one candidate sampler must be tested simultaneously. Such a 
configuration is designated as a case. Each case needs to be repeated 
three times for each of the different blow-off phases (1, 2, 3, 4 hours 
in duration). The external chamber is used to condition, handle and 
weigh filters. The temperature in both chambers shall be maintained at 
22  0.5  deg.C. The relative humidity (RH) in both chambers 
shall be maintained at 40 percent  3 percent.

[[Page 65839]]

    (2) Aerosol generation system. A pressure nebulizer shall be used 
to produce a polydisperse aerosol at a mass median diameter of less 
than 2.5 m. The polydisperse aerosol shall be generated from 
A.C.S. reagent grade glycerol of 99.5 percent minimum purity. To 
provide direct interlaboratory comparability of sampler volatility 
characteristics, the required nebulizer is Part # 5207, manufactured by 
Seamless, a division of Professional Medical Products, Inc (Greenwood, 
SC). The concentration of the aerosol inside the internal chamber shall 
not exceed 2 mg/m3, or any concentration that would overload the 
filters; (such overloading can be observed as ``wetted areas'). The 
concentration inside the chamber shall be at least 1 mg/m3 to 
obtain significant filter loading.
    (3) Air velocity verification. The chamber air velocity must be 
measured using an appropriate technique capable of 5 percent precision 
or better.
    (d) Test procedures. (1) This procedure shall be used to test the 
performance of candidate equivalent methods of type I and type II in 
which suspended particulate matter is collected on a filter. Two 
candidate samplers and two reference method samplers must be tested. 
One reference method sampler and one candidate sampler must be 
simultaneously subjected to the entire test procedure to ensure that 
both samplers are exposed to the identical aerosol. This can be 
achieved by using a manifold which allows connection of two samplers 
outside the internal chamber.
    (2) This method consists of three consecutive phases. In the first 
phase designated as A, temperature, relative humidity inside and 
outside the internal chamber must be maintained at the levels in 
paragraph (d)(1) of this section and the aerosol concentration and size 
distribution inside the internal chamber must be stabilized at the 
level prescribed in paragraph (d)(1) of this section. The samplers'' 
filters are conditioned dynamically by drawing aerosol-free air. Such 
air can be produced by filtering air from the external chamber through 
the absolute (HEPA) filter. The duration of filter conditioning shall 
be sufficient to obtain complete filter equilibration. In the second 
phase, designated as B, both samplers shall draw aerosol-laden air at a 
constant flow rate for 30 minutes. In the third phase designated as C, 
samplers draw aerosol-free and aerosol compound vapor free air, to 
produce partial volatilization of the collected aerosol, over single 
time periods of 1, 2, 3, and 4 hours. In each test, phase C is preceded 
by phase A and phase B using a new set of filters. Phase C shall be 
conducted immediately after completion of the phase B. The setup used 
in phase A can be used to produce air needed in phase C.
    (e) Filter handling. Careful handling of the filter during 
sampling, conditioning, and weighing is necessary to avoid errors due 
to damaged filters or loss of collected particles from the filters. All 
filters must be weighed immediately after phase A and phase C.
    (f) Temperature, humidity, and static charge considerations.--(1) 
Temperature and humidity. The effects of temperature and humidity can 
be minimized by equilibrating the test filters at conditions inside the 
external chamber. Total dynamic conditioning can be established by 
sequential filter weighing every 30 minutes following repetitive 
dynamic conditioning. The filters are considered sufficiently 
conditioned if the sequential weights are repeatable to 
3g. The temperature and relative humidity changes 
in which the filter is exposed during the entire procedure must not 
exceed + 0.5  deg.C for the temperature and  3 
percent RH, respectively.
    (2) Static charge. The following procedure is suggested for 
minimizing charge effects. Place six or more Polonium static control 
devices (PSCD) inside the microbalance weighing chamber, (MWC). Two of 
them must be placed horizontally on the floor of the MWC and the 
remainder placed vertically on the back wall of the MWC. Taping two 
PSCD's together or using double-sided tape will help to keep them from 
falling. Place the filter that is to be weighed on the horizontal PSCDs 
facing aerosol coated surface up. Close the MWC and wait 1 minute. Open 
the MWC and place the filter on the balance dish. Wait 1 minute. If the 
charges have been neutralized the weight will stabilize within 30-60 
seconds. Repeat the procedure of neutralizing charges and weighing as 
prescribed above several times (typically 2-4 times) until consecutive 
weights will differ by no more than 3 micrograms. Record the last 
measured weight and use this value for all subsequent calculations.
    (g) Artifacts. Additional negative or positive artifacts in 
collected mass during the first sampling period may occur. Such 
artifacts shall be minimized by producing and preserving the chemical 
composition of the air inside the internal chamber to provide 
thermodynamic and physicochemical states of equilibrium for the 
particles.
    (h) Calculations. Filters shall be weighed before the aerosol 
loading phase and immediately after the blow-off phase. The latter 
weight is subtracted from the former weight to calculate the residual 
mass (RM). The mass on the filter from the tested candidate sampler is 
multiplied by the volumetric sampling flows ratio, i.e., Frm flow rate/
Candidate flow rate, to produce a corrected residual mass (CRM).
    (i) Test for comparability. Comparability of the candidate method 
shall be established by calculating regression parameters for the 
regression of the CRMs obtained using candidate devices on RMs obtained 
using FRM devices. If the linear regression parameters [slope, 
intercept and correlation] meet the following values: Slope=1 
 0.1, intercept=0  0.15, correlation r 
0.97, the candidate method passes this test for 
comparability.

Tables to Subpart F of Part 53

  Table F-1.--Performance Specifications for PM2.5 Class II Equivalent  
                                Samplers                                
------------------------------------------------------------------------
      Performance test           Specifications      Acceptance criteria
------------------------------------------------------------------------
Full Wind Tunnel Evaluation   VOAG produced         Dp50 = 2.5 m    
                               and 24 km/hr.         0.2 m;    
                                                     Numerical Analysis 
                                                     Results: 95% Rc105% for          
                                                     distributions      
                                                     presented in Tables
                                                     F-4, F-5, and F-6. 
Wind Tunnel Inlet Aspiration  3.5 m        Relative Aspiration:
 Test Sec.  53.63.             liquid VOAG           95% Means
                               size in conjunction   105%, CV  10%.           
                               2 km/hr and 24 km/                       
                               hr.                                      
Static Fractionator Test      Evaluation of the     Dp50 = 2.5 m    
                               static conditions.    0.2 m;    
                               See Table F-2 for     Numerical Analysis 
                               specifications        Results: 95% Rc105% for          
                               types.                distributions      
                                                     presented in Tables
                                                     F-4, F-5, and F-6. 

[[Page 65840]]

                                                                        
Loading Test Sec.  53.65....  Loading of the clean  24 hour test and    
                               candidate under       Extended test; Dp50
                               laboratory            = 2.5 m   
                               conditions: 24 hour    0.2   
                               test, extended test.  m;        
                                                     Numerical Analysis 
                                                     Results: 95% Rc105% for          
                                                     distributions      
                                                     presented in Tables
                                                     F-4, F-5, and F-6. 
Volatility Test Sec.  53.66.  Polydisperse liquid   Regression          
                               aerosol produced by   Parameters Slope = 
                               air nebulization of   1  0.1,
                               A.C.S. reagent        Intercept = 0  0.15 r      
                               99.5% minimum         0.97.              
                               purity.                                  
------------------------------------------------------------------------


 Table F-2.--Particle Sizes and Wind Speeds for Full Wind Tunnel Evaluation, Wind Tunnel Inlet Aspiration Test, 
                                             and Static Chamber Test                                            
----------------------------------------------------------------------------------------------------------------
                                         Full wind tunnel test   Inlet aspiration test     Static               
 Primary partical mean size a (m)                     2 km/hr    24 km/hr     2 km/hr    24 km/hr       test         test   
----------------------------------------------------------------------------------------------------------------
1.50.25...................          S           S                                    S              
2.00.25...................          S           S                                    S              
2.50.25...................          S           S                                    S              
2.80.25...................          S           S                                    S              
3.50.25...................          S           S           L           L            S              
4.00.5....................          S           S                                    S              
Polydisperse Glycerol Aerosol.........                                                                        L 
----------------------------------------------------------------------------------------------------------------
a Aerodynamic diameter.                                                                                         
S=solid particles.      L=liquid particles.                                                                     


                                    Table F-3.--Critical Parameters of Idealized Ambient Particle Size Distributions                                    
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                             Fine particle mode                    Coarse particle mode                      FRM sampler
                                                  ------------------------------------------------------------------------------   PM2.5/     expected  
              Idealized distribution                                            Conc.                                  Conc.        PM10     mass conc. 
                                                   MMD (g/  MMD (g/    ratio    (g/
                                                       m>m)         Dev.         m3)          m>m)         Dev.         m3)                      m3)    
--------------------------------------------------------------------------------------------------------------------------------------------------------
Coarse...........................................         0.50           2         12.0            10           2         88.0        0.27       13.814 
``Typical''......................................         0.50           2         33.3            10           2         66.7        0.55       34.284 
Fine.............................................         0.85           2         85.0            15           2         15.0        0.94       78.539 
--------------------------------------------------------------------------------------------------------------------------------------------------------


BILLING CODE 6560-50-P

[[Page 65841]]

[GRAPHIC] [TIFF OMITTED] TP13DE96.120



[[Page 65842]]

[GRAPHIC] [TIFF OMITTED] TP13DE96.121



[[Page 65843]]

[GRAPHIC] [TIFF OMITTED] TP13DE96.122



[[Page 65844]]

Figures to Subpart F of Part 53
[GRAPHIC] [TIFF OMITTED] TP13DE96.123


[[Page 65845]]

[GRAPHIC] [TIFF OMITTED] TP13DE96.124



BILLING CODE 6560-50-C

[[Page 65846]]

Appendix A to Subpart F of Part 53--References

1. Marple, V.A., K.L. Rubow, W. Turner, and J.D. Spangler, Low Flow 
Rate Sharp Cut Impactors for Indoor Air Sampling: Design and 
Calibration., JAPCA, 37: 1303-1307 (1987).
2. Vanderpool, R.W. and K.L. Rubow, ``Generation of Large, Solid 
Calibration Aerosols'', J. of Aer. Sci. and Tech., 9:65-69 (1988).

PART 58--[AMENDED]

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

    Authority: 42 U.S.C. 7410, 7601(a), 7613, and 7619.

    2. Section 58.1 is amended by revising paragraph (s) and adding 
paragraphs (jj) through (vv) to read as follows:


Sec. 58.1  Definitions.

* * * * *
    (s) Traceable means that a local standard has been compared and 
certified, either directly or via not more than one intermediate 
standard, to a National Institute of Standards and Technology (NIST)-
certified primary standard such as a NIST-Traceable Reference Material 
(NTRM) or a NIST-certified Gas Manufacturer's Internal Standard (GMIS).
* * * * *
    (jj) Consolidated Metropolitan Statistical Area means the most 
recent area as designated by the U.S. Office of Management and Budget 
and population figures from the Bureau of the Census. The Department of 
Commerce provides ``that within metropolitan complexes of 1 million or 
more population, separate component areas are defined if specific 
criteria are met. Such areas are designated primary metropolitan 
statistical areas (PMSAs; and any area containing PMSAs is designated 
consolidated metropolitan statistical area (CMSA).''
    (kk) Core PM2.5 SLAMS means SLAMS sites which are the basic 
component sites of the PM2.5 SLAMS regulatory network. Population-
oriented core sites are intended to reflect community-wide exposure to 
air pollution.
    (ll) Equivalent method means a method of sampling and analyzing the 
ambient air for an air pollutant that has been designated as an 
equivalent method in accordance with this part; it does not include a 
method for which an equivalent method designation has been canceled in 
accordance with 40 CFR 53.11 or 53.16.
    (mm) Metropolitan Statistical Area (MSA) means the most recent area 
as designated by the U.S. Office of Management and Budget and 
population figures from the U.S. Bureau of the Census. The Department 
of Commerce defines a metropolitan area as ``one of a large population 
nucleus, together with adjacent communities which have a high degree of 
economic and social integration with that nucleus.''
    (nn) Monitoring Planning Area (MPA) means a contiguous geographic 
area with established, well defined boundaries, such as a metropolitan 
statistical area, county or State, having a common area that is used 
for planning monitoring locations for PM2.5. MPAs may cross State 
boundaries, such as the Philadelphia PA-NJ MSA, and be further 
subdivided into spatial averaging zones. MPAs are generally oriented 
toward areas with populations greater than 250,000, but for 
convenience, those portions of a State that are not part of MSAs can be 
considered as a single MPA. MPAs must be defined, where applicable, in 
a State monitoring plan.
    (oo) Particulate Matter Monitoring Plan means a detailed plan, 
prepared by control agencies and submitted to EPA for approval, that 
describes their PM2.5 and PM10 air quality surveillance 
network.
    (pp) PM2.5 means particulate matter with an aerodynamic 
diameter less than or equal to a nominal 2.5 micrometers as measured by 
a reference method based on appendix L of part 50 of this chapter and 
designated in accordance with part 53 of this chapter or by an 
equivalent method designated in accordance with part 53 of this 
chapter.
    (qq) Population oriented monitoring or sites applies to residential 
areas, commercial areas, recreational areas, industrial areas where 
workers from more than one company are located, and other areas where a 
substantial number of people may spend a significant fraction of their 
day.
    (rr) Primary Metropolitan Statistical Area (PMSA) is a separate 
component of a consolidated metropolitan statistical area. For the 
purposes of this regulation, PMSA is used interchangeably with MSA.
    (ss) Reference method means a method of sampling and analyzing the 
ambient air for an air pollutant that is specified as a reference 
method in an appendix to part 50 of this chapter, or a method that has 
been designated as a reference method in accordance with this part; it 
does not include a method for which a reference method designation has 
been canceled in accordance with 40 CFR 53.11 or 53.16.
    (tt) Spatial averaging zone (SAZ) means an area with established, 
well defined boundaries, such as a county or census block, within a MPA 
that has relatively uniform concentrations of PM2.5. Monitors 
within a SAZ that meet certain requirements as set forth in Appendix D 
of this part are used to compare with the primary annual PM2.5 
NAAQS using a spatial averaging procedure specified in Appendix K of 40 
CFR Part 50. A SAZ may have one or more monitors. An MPA must have at 
least one SAZ and may have several SAZs.
    (uu) SPM monitors is a generic term used for all monitors other 
than SLAMS, NAMS, PAMS, and PSD monitors included in an agency's 
monitoring plan or for monitors used in special study whose data are 
officially reported to EPA.
    (vv) Annual State Air Monitoring Report (ASAMR) is an annual 
report, prepared by control agencies and submitted to EPA for approval, 
that consists of an annual data summary report for all pollutants and a 
detailed report describing any proposed changes to their air quality 
surveillance network.
    3. Section 58.13 is amended by revising paragraph (d) and adding 
new paragraphs (e) and (f) as follows:


Sec. 58.13  Operating schedule.

* * * * *
    (d) For PM10 samplers--a 24-hour sample must be taken a 
minimum of every sixth day.
    (e) For PM2.5 samplers, everyday sampling is required for all 
core SLAMS, including NAMS and PAMS core stations, except during 
seasons or as otherwise exempted by the Regional Administrator in 
accordance with EPA guidance. For other SLAMS, a minimum frequency of 1 
in 6 day sampling schedule is allowed and suggested. Alternative 
sampling frequencies are also allowed for SLAMS sites which are 
principally intended for comparisons to the 24-hour NAAQS. Such 
modifications must be approved by the EPA Administrator in accordance 
with EPA guidance.
    (f) Alternatives to everyday sampling. (1) PM2.5 core SLAMS 
sites located in monitoring planning areas (as described in section 2.8 
of Appendix D of this subpart) are required to sample every day with a 
reference or equivalent method operating in accordance with 40 CFR part 
53 and Section 2 of Appendix C to this part. However, in accordance 
with the monitoring priority as defined in paragraph (f)(2) of this 
section, established by the control agency and approved by EPA, a core 
SLAMS monitor may operate with a reference or equivalent method on a 1 
in 3 day schedule and produce data that may be compared to the NAAQS, 
provided that

[[Page 65847]]

it is collocated with an acceptable continuous fine particle PM 
analyzer that is correlated with the reference or equivalent method. If 
the alternative sampling schedule is selected by the control agency and 
approved by EPA, the alternative schedule shall be implemented on 
January 1 of the year in which everyday sampling is required. The 
selection of correlated acceptable continuous PM analyzers and 
procedures for correlation with the intermittent reference or 
equivalent method shall be in accordance with procedures to be 
established and included in EPA guidance. Unless the continuous fine 
particle analyzer satisfies the requirements of Section 2 of Appendix C 
to 40 CFR Part 58, however, the data derived from the correlated 
acceptable continuous monitor are not eligible for direct comparisons 
to the NAAQS in accordance with Part 50.
    (2) A Metropolitan Statistical Area (or primary metropolitan 
statistical area) with greater than 1 million population and high 
concentrations of PM2.5 (greater than or equal to 80 percent of 
the NAAQS) shall be a Priority 1 PM monitoring area. Other monitoring 
planning areas may be designated as Priority 2 PM monitoring areas.
    (3) Core SLAMS having a correlated acceptable continuous analyzer 
collocated with a reference or equivalent method in a Priority 1 PM 
monitoring area may operate on the 1 in 3 sampling frequency only after 
reference or equivalent data are collected for at least two complete 
years and the area is determined to be attainment with the PM2.5 
NAAQS in accordance with Appendix K to 40 CFR Part 50. See Figure 
below. After this time and for as long as the area is in attainment 
with the PM2.5 NAAQS, the correlated acceptable continuous option 
may be used in conjunction with 1 in 3 day intermittent sampling. Other 
core SLAMS may utilize correlated acceptable continuous monitors in 
conjunction with intermittent sampling on a 1 in 3 schedule for the 
first year of required PM2.5 sampling.
    (4) After one complete year of PM2.5 sampling, if a violation 
of the NAAQS is determined (in accordance with Appendix K to 40 CFR 
part 50), then everyday sampling with reference or equivalent method 
would be required subsequently. Otherwise, the core SLAMS in this area 
may continue to sample a minimum of 1 in 3 days using a reference or 
equivalent method together with the correlated acceptable continuous 
monitor. Background and transport PM2.5 core SLAMS in States with 
population-oriented core monitors may sample with correlated acceptable 
continuous alternative in accordance with the highest priority 
PM2.5 core SLAMS for the State. In States without population-
oriented core monitors or where operation of population-oriented core 
monitors has been exempted by the Regional Administrator, the 
background and transport PM2.5 core SLAMS may also sample a 
minimum of 1 in 3 days. Background PM2.5 sites which are downwind 
of areas without anthropogenic sources of PM2.5, (e.g., the 
Pacific Ocean) may also sample 1 in 3 days.
    (5) In all monitoring situations, with a correlated acceptable 
continuous alternative, FRM samplers or filter-based equivalent 
analyzers should preferably accompany the correlated acceptable 
continuous monitor.
    4. Section 58.14 is revised as follows:


Sec. 58.14  Special purpose monitors.

    (a) Except as specified in paragraph (b) of this section, any 
ambient air quality monitoring station other than a SLAMS or PSD 
station from which the State intends to use the data as part of a 
demonstration of attainment or nonattainment or in computing a design 
value for control purposes of the National Ambient Air Quality 
Standards (NAAQS) must meet the requirements for SLAMS as described in 
Sec. 58.22 and, after January 1, 1983, must also meet the requirements 
for SLAMS described in Sec. 58.13 and Appendices A and E of this part.
    (b) PM2.5 NAAQS violations shall not be made based on data 
produced at an SPM site during the first 3 years following the 
effective date of the final rule. However, a notice of NAAQS violations 
resulting from SPMs shall be reported to EPA in the State's annual 
monitoring plan and be considered by the State in the design of its 
overall SLAMS network, and should be considered to become permanent 
SLAMS during the annual network review in accordance with Sec. 58.25.
    (c) Any ambient air quality monitoring station other than a SLAMS 
or PSD station from which the State intends to use the data for SIP-
related functions other than as described in paragraph (a) of this 
section is not necessarily required to comply with the requirements for 
a SLAMS station under paragraph (a) of this section but must be 
operated in accordance with a monitoring schedule, methodology, quality 
assurance procedures, and probe or instrument-siting specifications 
approved by the Regional Administrator.
    5. A new Sec. 58.15 is added to read as follows:


Sec. 58.15  Designation of monitoring sites eligible for comparison to 
the PM2.5 NAAQS.

    (a) SLAMS and SPM monitors that will be used to make comparisons 
with the 24-hour and annual NAAQS for PM2.5 shall be identified in 
the State's monitoring plan, subject to annual review and approval by 
the Regional Administrator, and designated as code ``B'' in EPA's AIRS 
monitoring site file.
    (b) SLAMS and SPM monitors that will be used to make comparisons 
only with the 24-hour NAAQS for PM2.5 shall be identified in the 
States monitoring plan, subject to annual review and approval by the 
Regional Administrator, and designated as code ``D'' in EPA's AIRS 
monitoring site file.
    (c) All other PM2.5 sites would be designated as code ``O'' 
sites in EPA's AIRS monitoring site file.
    6. Section 58.20 is amended by revising paragraphs (d), (e) 
introductory text, and (e)(5); by redesignating paragraph (f) as (g); 
and adding a new paragraph (f) to read as follows:


Sec. 58.20  Air quality surveillance: Plan control.

* * * * *
    (d) Provide for the review of the air quality surveillance system 
on an annual basis to determine if the system meets the monitoring 
objectives defined in Sec. 2.8 of appendix D to this part as well as 
the minimum requirements for networks of SLAMS stations for PM2.5 
described in Sec. 2.8.2 of appendix D of this part. Such review must 
identify needed modifications to the network such as termination or 
relocation of unnecessary stations or establishment of new stations 
which are necessary. For PM2.5, the review must identify needed 
changes to core stations, monitoring planning areas, spatial averaging 
zones, or monitoring sites which are eligible for comparison to the 
NAAQS.
    (e) Provide for having a SLAMS network description, including 
monitoring planning areas and spatial averaging zones for PM2.5, 
available for public inspection and submission to the Administrator 
upon request. The network description must be available at the time of 
plan revision submittal except for PM10 and PM2.5, which must 
be available by 6 months after the effective date of promulgation and 
must contain the following information for each SLAMS:
* * * * *
    (5) The monitoring objective, spatial scale of representativeness, 
and for PM2.5, the monitoring planning area, spatial averaging 
zone, and the site code designation to identify which site will be used 
to determine violations of the appropriate PM NAAQS (annual or 24-

[[Page 65848]]

hour), as defined in appendix D to this part.
    (f) Provide for having a list of all PM2.5 monitoring 
locations including SLAMS, NAMS and SPMs, which are included in the 
State's monitoring plan and are intended for comparison to the NAAQS, 
available for public inspection
* * * * *
    7. Section 58.23 is amended by revising the introductory text and 
adding a new paragraph (c) to read as follows:


Sec. 58.23  Monitoring network completion.

    By January 1, 1983, with the exception of PM10 samplers which 
shall be within 6 months of the date of publication of the final rule 
and with the exception of PM2.5 samplers which shall be as 
described in paragraph (c) of this section.
* * * * *
    (c) Each PM2.5 station in the SLAMS network must be in 
operation in accordance with the minimum requirements of appendix D of 
this part, be sited in accordance with the criteria in appendix E to 
this part, and be located as described on the station's AIRS site 
identification form, according to the following schedule:
    (1) Within 1 year of the effective date of promulgation, the 
required core PM2.5 SLAMS for at least one MPA must be in 
operation;
    (2) Within 2 years of promulgation, all other required core-
population oriented sites and core background and transport sites must 
be in operation; and
    (3) Within 3 years of promulgation, a continuous PM monitor in 
areas with greater than 1 million population, all NAMS sites and all 
additional required PM2.5 SLAMS must be in operation.
    8-9. In Sec. 58.26, revise the section heading paragraph (b) 
introductory text and add paragraphs (d) and (e) to read as follows:


Sec. 58.26  Annual State Air Monitoring Report.

* * * * *
    (b) The SLAMS annual data summary report must contain:
* * * * *
    (d) For PM--
    (1) The State shall submit a summary to the appropriate Regional 
Office (for SLAMS) or Administrator (through the Regional Office) (for 
NAMS) which details proposed changes to the PM Monitoring Plan and to 
be in accordance with the annual network review requirements 
Sec. 58.25. This shall discuss the existing PM networks, including 
modifications to the number, size or boundaries of monitoring planning 
areas and spatial averaging zones; number and location of PM SLAMS; 
number or location of core PM2.5 SLAMS; alternative sampling 
frequencies proposed for PM2.5 SLAMS (including core PM2.5 
SLAMS and PM2.5 NAMS), core PM2.5 SLAMS to be designated 
PM2.5 NAMS; and PM SLAMS to be designated PM NAMS.
    (2) the State shall submit an annual summary to the appropriate 
Regional Office of all the ambient air quality monitoring PM data from 
all special purpose monitors which are described in the States 
monitoring plan and are intended for SIP purposes. These include those 
population oriented SPMs which are eligible for comparison to the PM 
NAAQS. The State shall certify the data in accordance with paragraph 
(c) of this section.
    (e) The Annual State Air Monitoring Report shall be submitted to 
the Regional Administrator by July 1 or by alternative annual date to 
be negotiated between the State and Regional Administrator. The Region 
shall provide review and approval/disapproval within 45 days. After the 
first 3 years following effective promulgation of the PM2.5 NAAQS 
or once a SAZ has been determined to violate the NAAQS, then changes to 
an MPA shall require public review and notification.


Sec. 58.30  NAMS network establishment.

    10. In Sec. 58.30, paragraph (a) introductory text is revised to 
read as follows:
    (a) By January 1, 1980, with the exception of PM10 samplers, 
which shall be by 6 months after the effective date of the final rule, 
and PM2.5, which shall be by 3 years after the effective date of 
promulgation, the State shall:
* * * * *
    11. In Sec. 58.31, paragraph (f) is revised to read as follows:


Sec. 58.31  NAMS network description.

* * * * *
    (f) The monitoring objective, spatial scale of representativeness, 
and for PM2.5, the monitoring planning area, spatial averaging 
zone, and the site code designation to identify which site will be used 
to determine violations of the appropriate NAAQS (annual or 24-hour), 
as defined in appendix D to this part.
* * * * *
    12. In Sec. 58.34, the introductory text is revised to read as 
follows:


Sec. 58.34  NAMS network completion.

    By January 1, 1981, with the exception of PM10 samplers, which 
shall be by 6 months after the effective date of final rule, and 
PM2.5, which shall be by 3 years after the effective date of final 
rule:
* * * * *
    13. In Sec. 58.35, the first sentence of paragraph (b) is revised 
to read as follows:


Sec. 58.35  NAMS data submittal.

* * * * *
    (b) The State shall report to the Administrator all ambient air 
quality data for SO2, CO, O3, NO2, Pb, PM10, and 
PM2.5, and information specified by the AIRS Users Guide (Volume 
II, Air Quality Data Coding, and Volume III, Air Quality Data Storage) 
to be coded into the AIRS-AQS format.
* * * * *
    14. Revise Appendix A of part 58 to read as follows:

Appendix A to Part 58--Quality Assurance Requirements for State and 
Local Air Monitoring Stations (SLAMS)

1. General Information.

    1.1 This appendix specifies the minimum quality assurance/
quality control requirements applicable to SLAMS air monitoring data 
submitted to EPA. State and local agencies are encouraged to develop 
and maintain quality assurance programs more extensive than the 
required minimum.
    1.2 To assure the quality of data from air monitoring 
measurements, two distinct and important interrelated functions must 
be performed. One function is the control of the measurement process 
through broad quality assurance activities, such as establishing 
policies and procedures, assigning roles and responsibilities, 
conducting oversight and reviews, and implementing corrective 
actions. The other function is the control of the measurement 
process through the implementation of specific quality control 
procedures, such as calibrations, checks, replicates, routine self-
assessments, etc. In general, the greater the control of a given 
monitoring system, the better will be the resulting quality of the 
monitoring data. The results of quality assurance reviews and 
assessments indicate whether the control efforts are adequate or 
need to be improved.
    1.3  Documentation of all quality assurance and quality control 
efforts implemented during the data collection, analysis, and 
reporting phases is important to data users, who can then consider 
the impact of these control efforts on the data quality (see 
Reference 1 of this appendix). Both qualitative and quantitative 
assessments of the effectiveness of these control efforts should 
identify those areas most likely to impact the data quality and to 
what extent.
    1.4  Periodic assessments of SLAMS data quality are required to 
be reported to EPA. To provide national uniformity in this 
assessment and reporting of data quality for all SLAMS networks, 
specific assessment and reporting procedures are prescribed in 
detail in sections 3, 4, and 5 of this appendix. On the other hand, 
the selection and extent of the quality assurance and quality 
control

[[Page 65849]]

activities used by a monitoring agency depend on a number of local 
factors such as the field and laboratory conditions, the objectives 
of the monitoring, the level of the data quality needed, the 
expertise of assigned personnel, the cost of control procedures, 
pollutant concentration levels, etc. Therefore, the quality system 
requirements, in section 2 of this appendix, are specified in 
general terms to allow each State to develop a quality assurance 
program that is most efficient and effective for its own 
circumstances.

2. Quality System Requirements

    2.1  Each State and local agency must develop and implement a 
quality assurance program consisting of policies, procedures, 
specifications, standards, and documentation necessary to:
    (1) Provide data of adequate quality to meet monitoring 
objectives, and
    (2) Minimize loss of air quality data due to malfunctions or 
out-of-control conditions. This quality assurance program must be 
described in detail, suitably documented, and approved by the 
appropriate Regional Administrator, or the Administrator's designee. 
The Quality Assurance Program will be reviewed during the systems 
audits described in section 2.5 of the appendix.
    2.2  Primary guidance for developing the quality assurance 
program is contained in References 2-7 of this appendix, which also 
contain many suggested procedures, checks, and control 
specifications. Reference 7 of this appendix describes specific 
guidance for the development of a Quality Assurance Program for 
SLAMS. Many specific quality control checks and specifications for 
manual methods are included in the respective reference methods 
described in part 50 of this chapter or in the respective manual 
equivalent method descriptions available from EPA (see Reference 8 
of this appendix). Similarly, quality control procedures related to 
specifically designated reference and equivalent method analyzers 
are contained in the respective operation or instruction manuals 
associated with those analyzers. Quality assurance guidance for 
meteorological systems at PAMS is contained in Reference 9. Quality 
assurance procedures for VOC, NOx (including NO and NO2), 
O3, and carbonyl measurements at PAMS must be consistent with 
EPA guidance. Quality assurance and control programs must follow the 
requirements established by ANSI E-4 (Reference 2 of this appendix) 
and must undergo systems audits demonstrating attainment of the 
requirements. This guidance, and any other pertinent information 
from appropriate sources, should be used by the agencies in 
developing their quality assurance programs. As a minimum, each 
quality assurance program must include operational procedures for 
each of the following activities:
    (1) Selection of methods, analyzers, or samplers;
    (2) Training;
    (3) Installation of equipment;
    (4) Selection and control of calibration standards;
    (5) Calibration;
    (6) Zero/span checks and adjustments of automated analyzers;
    (7) Control checks and their frequency;
    (8) Control limits for zero, span and other control checks, and 
respective corrective actions when such limits are surpassed;
    (9) Calibration and zero/span checks for multiple range 
analyzers (see section 2.6 of Appendix C of this part);
    (10) Preventive and remedial maintenance;
    (11) Quality control procedures for air pollution episode 
monitoring;
    (12) Recording and validating data;
    (13) Data quality assessment (precision and accuracy);
    (14) Documentation of quality assurance and quality control 
information; and
    (15) Control of pertinent documents and records in print and 
electronic forms.
    2.3  Pollutant Concentration and Flow Rate Standards.
    2.3.1  Gaseous pollutant concentration standards (permeation 
devices or cylinders of compressed gas) used to obtain test 
concentrations for CO, SO2, NO, and NO2 must be traceable 
to either a National Institute of Standards and Technology (NIST) 
NIST-Traceable Reference Material (NTRM) or a NIST-certified Gas 
Manufacturer's Internal Standard (GMIS), certified in accordance 
with one of the procedures given in Reference 10.
    2.3.2  Test concentrations for O3 must be obtained in 
accordance with the UV photometric calibration procedure specified 
in appendix D of part 50 of this chapter, or by means of a certified 
ozone transfer standard. Consult References 11 and 12 for guidance 
on primary and transfer standards for O3.
    2.3.3  Flow rate measurements must be made by a flow measuring 
instrument that is traceable to an authoritative volume or other 
applicable standard. Guidance for certifying some types of 
flowmeters is provided in Reference 7.
    2.4  National Performance Audit Program. Agencies operating 
SLAMS are required to participate in EPA's National Performance 
Audit Program. These audits are described in sections 2.0.10 and 
2.0.11 of Reference 7. For further instructions, agencies should 
contact either the appropriate EPA Regional Quality Assurance 
Coordinator or the National Performance Audit Program Coordinator, 
Quality Assurance Branch (MD-77B), National Exposure Research 
Laboratory, U.S. Environmental Protection Agency, Research Triangle 
Park, NC 27711.
    2.5  Systems Audit Programs. Systems audits of the ambient air 
monitoring programs of agencies operating SLAMS shall be conducted 
at least every three years by the appropriate EPA Regional Office. 
Quality assurance and control programs must follow the requirements 
established by ANSI E-4 (Reference 2 of this appendix) and described 
in Reference 7. For further instructions, agencies should contact 
either the appropriate EPA Regional Quality Assurance Coordinator or 
the Systems Audit Quality Assurance Coordinator, Office of Air 
Quality Planning and Standards, Emissions Monitoring and Analysis 
Division (MD-14), U.S. Environmental Protection Agency, Research 
Triangle Park, NC 27711.

3. Data Quality Assessment Requirements.

    3.0.1  All ambient monitoring methods or analyzers used in SLAMS 
shall be tested periodically, as described in this section, to 
quantitatively assess the quality of the SLAMS data being routinely 
produced. Measurement accuracy and precision are estimated for both 
automated and manual methods. The individual results of these tests 
for each method or analyzer shall be reported to EPA as specified in 
section 4. EPA will then calculate quarterly integrated estimates of 
precision and accuracy applicable to the SLAMS data as described in 
section 5 of this appendix. Data assessment results should be 
reported to EPA only for methods and analyzers approved for use in 
SLAMS monitoring under appendix C of this part.
    3.0.2  The integrated estimates of the data quality will be 
calculated on the basis of ``reporting organizations'' and may also 
be calculated for each region and for the entire nation. These 
estimates will primarily pool all methods for each pollutant, but 
estimates may also be made for specific instrument types identified 
by EPA method code, which is uniquely related to each reference and 
equivalent method designated by the EPA under part 53 of this 
chapter. A ``reporting organization'' is defined as a State, 
subordinate organization within a State, or other organization that 
is responsible for a set of stations that monitors the same 
pollutant and for which precision or accuracy assessments can be 
pooled. States must define one or more reporting organizations for 
each pollutant such that each monitoring station in the State SLAMS 
network is included in one, and only one, reporting organization.
    3.0.3  Each reporting organization shall be defined such that 
precision or accuracy among all stations in the organization can be 
expected to be reasonably homogeneous, as a result of common 
factors. Common factors that should be considered by States in 
defining reporting organizations include:
    (1) Operation by a common team of field operators;
    (2) Common calibration facilities; and
    (3) Support by a common laboratory or headquarters. Where there 
is uncertainty in defining the reporting organizations or in 
assigning specific sites to reporting organizations, States shall 
consult with the appropriate EPA Regional Office for guidance. All 
definitions of reporting organizations shall be subject to final 
approval by the appropriate EPA Regional Office.
    3.0.4  Assessment results shall be reported as specified in 
section 4 of this Appendix. Concentration and flow rate standards 
must be as specified in sections 2.3 or 3.4 of this Appendix. In 
addition, working standards and equipment used for accuracy audits 
must not be the same standards and equipment used for routine 
calibrations. Additional information and guidance in the technical 
aspects of conducting these tests may be found in Reference 7 or in 
the operation or instruction manual associated with the analyzer or 
sampler. Concentration measurements reported from analyzers or 
analytical systems (indicated concentrations) should be based on 
stable readings and must

[[Page 65850]]

be derived by means of the same calibration curve and data 
processing system used to obtain the routine air monitoring data 
(see Reference 1 and Reference 7 of this Appendix). Table A-1 of 
this Appendix provides a summary of the minimum data quality 
assessment requirements, which are described in more detail in the 
following sections.
    3.1  Precision of Automated Methods.
    3.1.1  Methods for SO2, NO2, O3 and CO. A one-
point precision check must be performed at least once every two 
weeks on each automated analyzer used to measure SO2, NO2, 
O3 and CO. The precision check is made by challenging the 
analyzer with a precision check gas of known concentration 
(effective concentration for open path analyzers) between 0.08 and 
0.10 ppm for SO2, NO2, and O3 analyzers, and between 
8 and 10 ppm for CO analyzers. To check the precision of SLAMS 
analyzers operating on ranges higher than 0 to 1.0 ppm SO2, 
NO2, and O3, or 0 to 100 ppm for CO, use precision check 
gases of appropriately higher concentration as approved by the 
appropriate Regional Administrator or the Regional Administrator's 
designee. However, the results of precision checks at concentration 
levels other than those specified above need not be reported to EPA. 
The standards from which precision check test concentrations are 
obtained must meet the specifications of section 2.3 of this 
Appendix.
    3.1.1.1  Except for certain CO analyzers described below, point 
analyzers must operate in their normal sampling mode during the 
precision check, and the test atmosphere must pass through all 
filters, scrubbers, conditioners and other components used during 
normal ambient sampling and as much of the ambient air inlet system 
as is practicable. If permitted by the associated operation or 
instruction manual, a CO point analyzer may be temporarily modified 
during the precision check to reduce vent or purge flows, or the 
test atmosphere may enter the analyzer at a point other than the 
normal sample inlet, provided that the analyzer's response is not 
likely to be altered by these deviations from the normal operational 
mode. If a precision check is made in conjunction with a zero or 
span adjustment, it must be made prior to such zero or span 
adjustments. Randomization of the precision check with respect to 
time of day, day of week, and routine service and adjustments is 
encouraged where possible.
    3.1.1.2  Open path analyzers are tested by inserting a test cell 
containing a precision check gas concentration into the optical 
measurement beam of the instrument. If possible, the normally used 
transmitter, receiver, and as appropriate, reflecting devices should 
be used during the test, and the normal monitoring configuration of 
the instrument should be altered as little as possible to 
accommodate the test cell for the test. However, if permitted by the 
associated operation or instruction manual, an alternate local light 
source or an alternate optical path that does not include the normal 
atmospheric monitoring path may be used. The actual concentration of 
the precision check gas in the test cell must be selected to produce 
an ``effective concentration'' in the range specified above. 
Generally, the precision test concentration measurement will be the 
sum of the atmospheric pollutant concentration and the precision 
test concentration. If so, the result must be corrected to remove 
the atmospheric concentration contribution. The ``corrected 
concentration'' is obtained by subtracting the average of the 
atmospheric concentrations measured by the open path instrument 
under test immediately before and immediately after the precision 
check test from the precision test concentration measurement. If the 
difference between these before and after measurements is greater 
than 20 percent of the effective concentration of the test gas, 
discard the test result and repeat the test. If possible, open path 
analyzers should be tested during periods when the atmospheric 
pollutant concentrations are relatively low and steady.
    3.1.1.3  Report the actual concentration (effective 
concentration for open path analyzers) of the precision check gas 
and the corresponding concentration measurement (corrected 
concentration, if applicable, for open path analyzers) indicated by 
the analyzer. The percent differences between these concentrations 
are used to assess the precision of the monitoring data as described 
in section 5.1.
    3.1.2  Methods for particulate matter. A one-point precision 
check must be performed at least once every two weeks on each 
automated analyzer used to measure PM10 and PM2.5. The 
precision check is made by checking the operational flow rate of the 
analyzer. If a precision flow rate check is made in conjunction with 
a flow rate adjustment, it must be made prior to such flow rate 
adjustment. Randomization of the precision check with respect to 
time of day, day of week, and routine service and adjustments is 
encouraged where possible.
    3.1.2.1  Standard procedure: Use a flow rate transfer standard 
certified in accordance with section 2.3.3 to check the analyzer's 
normal flow rate. Care should be used in selecting and using the 
flow rate measurement device such that it does not alter the normal 
operating flow rate of the analyzer. Report the actual analyzer flow 
rate measured by the transfer standard and the corresponding flow 
rate measured, indicated, or assumed by the analyzer.
    3.1.2.2  Alternative procedure:
    3.1.2.2.1  It is permissible to obtain the precision check flow 
rate data from the analyzer's internal flow meter without the use of 
an external flow rate transfer standard, provided that--
    3.1.2.2.1.1  the flow meter is audited with an external flow 
rate transfer standard at least every 6 months;
    3.1.2.2.1.2  records of at least the 3 most recent flow audits 
of the instrument's internal flow meter over at least several weeks 
confirm that the flow meter is stable, verifiable and accurate to 
4%; and
    3.1.2.2.1.3  the instrument and flow meter give no indication of 
improper operation.
    3.1.2.2.2  With suitable communication capability, the precision 
check may thus be carried out remotely. For this procedure, report 
the set-point flow rate as the ``actual flow rate'' along with the 
flow rate measured or indicated by the analyzer flow meter.
    3.1.2.2.3  For either procedure, the percent differences between 
the actual and indicted flow rates are used to assess the precision 
of the monitoring data as described in section 5.1 of this Appendix 
A (using flow rates in lieu of concentrations). The percent 
differences between these concentrations are used to assess the 
precision of the monitoring data as described in section 5.1.
    3.2  Accuracy of Automated Methods.
    3.2.1  Methods for SO2, NO2, O3, or CO.
    3.2.1.1  Each calendar quarter (during which analyzers are 
operated), audit at least 25 percent of the SLAMS analyzers that 
monitor for SO2, NO2, O3, or CO such that each 
analyzer is audited at least once per year. If there are fewer than 
four analyzers for a pollutant within a reporting organization, 
randomly reaudit one or more analyzers so that at least one analyzer 
for that pollutant is audited each calendar quarter. Where possible, 
EPA strongly encourages more frequent auditing, up to an audit 
frequency of once per quarter for each SLAMS analyzer.
    3.2.1.2  The audit is made by challenging the analyzer with at 
least one audit gas of known concentration (effective concentration 
for open path analyzers) from each of the following ranges 
applicable to the analyzer being audited:

------------------------------------------------------------------------
                                           Concentration range, ppm     
              Audit level            -----------------------------------
                                        SO2, O3        NO2         CO   
------------------------------------------------------------------------
1...................................    0.03-0.08    0.03-0.08      3-8 
2...................................    0.15-0.20    0.15-0.20     15-20
3...................................    0.35-0.45    0.35-0.45     35-45
4...................................    0.80-0.90  ...........     80-90
------------------------------------------------------------------------


[[Page 65851]]

    NO2 audit gas for chemiluminescence-type NO2 analyzers 
must also contain at least 0.08 ppm NO.
    3.2.1.3  NO concentrations substantially higher than 0.08 ppm, 
as may occur when using some gas phase titration (GPT) techniques, 
may lead to audit errors in chemiluminescence analyzers due to 
inevitable minor NO-NOX channel imbalance. Such errors may be 
atypical of routine monitoring errors to the extent that such NO 
concentrations exceed typical ambient NO concentrations at the site. 
These errors may be minimized by modifying the GPT technique to 
lower the NO concentrations remaining in the NO2 audit gas to 
levels closer to typical ambient NO concentrations at the site.
    3.2.1.4  To audit SLAMS analyzers operating on ranges higher 
than 0 to 1.0 ppm for SO2, NO2, and O3 or 0 to 100 
ppm for CO, use audit gases of appropriately higher concentration as 
approved by the appropriate Regional Administrator or the 
Administrators's designee. The results of audits at concentration 
levels other than those shown in the above table need not be 
reported to EPA.
    3.2.1.5  The standards from which audit gas test concentrations 
are obtained must meet the specifications of section 2.3. The gas 
standards and equipment used for auditing must not be the same as 
the standards and equipment used for calibration or calibration span 
adjustments. The auditor should not be the operator or analyst who 
conducts the routine monitoring, calibration, and analysis.
    3.2.1.6  For point analyzers, the audit shall be carried out by 
allowing the analyzer to analyze the audit test atmosphere in its 
normal sampling mode such that the test atmosphere passes through 
all filters, scrubbers, conditioners, and other sample inlet 
components used during normal ambient sampling and as much of the 
ambient air inlet system as is practicable. The exception provided 
in section 3.1 for certain CO analyzers does not apply for audits.
    3.2.1.7  Open path analyzers are audited by inserting a test 
cell containing the various audit gas concentrations into the 
optical measurement beam of the instrument. If possible, the 
normally used transmitter, receiver, and, as appropriate, reflecting 
devices should be used during the audit, and the normal monitoring 
configuration of the instrument should be modified as little as 
possible to accommodate the test cell for the audit. However, if 
permitted by the associated operation or instruction manual, an 
alternate local light source or an alternate optical path that does 
not include the normal atmospheric monitoring path may be used. The 
actual concentrations of the audit gas in the test cell must be 
selected to produce ``effective concentrations'' in the ranges 
specified in this section 3.2. Generally, each audit concentration 
measurement result will be the sum of the atmospheric pollutant 
concentration and the audit test concentration. If so, the result 
must be corrected to remove the atmospheric concentration 
contribution. The ``corrected concentration'' is obtained by 
subtracting the average of the atmospheric concentrations measured 
by the open path instrument under test immediately before and 
immediately after the audit test (or preferably before and after 
each audit concentration level) from the audit concentration 
measurement. If the difference between the before and after 
measurements is greater than 20 percent of the effective 
concentration of the test gas standard, discard the test result for 
that concentration level and repeat the test for that level. If 
possible, open path analyzers should be audited during periods when 
the atmospheric pollutant concentrations are relatively low and 
steady. Also, the monitoring path length must be reverified to 
within 3 percent to validate the audit, since the 
monitoring path length is critical to the determination of the 
effective concentration.
    3.2.1.8  Report both the actual concentrations (effective 
concentrations for open path analyzers) of the audit gases and the 
corresponding concentration measurements (corrected concentrations, 
if applicable, for open path analyzers) indicated or produced by the 
analyzer being tested. The percent differences between these 
concentrations are used to assess the accuracy of the monitoring 
data as described in section 5.2.
    3.2.2  Methods for particulate matter.
    3.2.2.1  Each calendar quarter, audit the flow rate of each 
SLAMS PM2.5 analyzer and at least 25 percent of the SLAMS 
PM10 analyzers such that each PM10 analyzer is audited at 
least once per year. If there are fewer than four PM10 analyzers 
within a reporting organization, randomly re-audit one or more 
analyzers so that at least one analyzer is audited each calendar 
quarter. Where possible, EPA strongly encourages more frequent 
auditing, up to an audit frequency of once per quarter for each 
SLAMS analyzer.
    3.2.2.2  The audit is made by measuring the analyzer's normal 
operating flow rate, using a flow rate transfer standard certified 
in accordance with section 2.3.3. The flow rate standard used for 
auditing must not be the same flow rate standard used to calibrate 
the analyzer. However, both the calibration standard and the audit 
standard may be referenced to the same primary flow rate or volume 
standard. Great care must be used in auditing the flow rate to be 
certain that the flow measurement device does not alter the normal 
operating flow rate of the analyzer. Report the audit (actual) flow 
rate and the corresponding flow rate indicated or assumed by the 
sampler. The percent differences between these flow rates are used 
to calculate accuracy as described in section 5.4.1.
    3.3  Precision of Manual Methods.
    3.3.1  For each network of manual methods other than for 
PM2.5, select one or more monitoring sites within the reporting 
organization for duplicate, collocated sampling as follows: for 1 to 
5 sites, select 1 site; for 6 to 20 sites, select 2 sites; and for 
over 20 sites, select 3 sites. For each network of manual methods 
for PM2.5, select one or more monitoring sites within the 
reporting organization for duplicate, collocated sampling as 
follows: for 1 to 10 sites, select 1 site; for 11 to 20 sites, 
select 2 sites; and for over 20 sites, select 3 sites. Where 
possible, additional collocated sampling is encouraged. For purposes 
of precision assessment, networks for measuring TSP, PM10, and 
PM2.5 shall be considered separately from one another. Sites 
having annual mean particulate matter concentrations among the 
highest 25 percent of the annual mean concentrations for all the 
sites in the network must be selected or, if such sites are 
impractical, alternative sites approved by the Regional 
Administrator may be selected.
    3.3.2  In determining the number of collocated sites required 
for PM10, monitoring networks for lead should be treated 
independently from networks for particulate matter, even though the 
separate networks may share one or more common samplers. However, a 
single pair of samplers collocated at a common-sampler monitoring 
site that meets the requirements for both a collocated lead site and 
a collocated particulate matter site may serve as a collocated site 
for both networks.
    3.3.3  In determining the number of collocated sites required 
for PM2.5, monitoring networks for visibility should not be 
treated independently from networks for particulate matter, as the 
separate networks may share one or more common samplers. However, 
for class I visibility areas, EPA will accept visibility aerosol 
mass measurement in lieu of a PM2.5 measurement if the latter 
measurement is unavailable.
    3.3.4  The two collocated samplers must be within 4 meters of 
each other, and particulate matter samplers must be at least 2 
meters apart to preclude airflow interference. Calibration, 
sampling, and analysis must be the same for both collocated samplers 
and the same as for all other samplers in the network.
    3.3.5  For each pair of collocated samplers, designate one 
sampler as the primary sampler whose samples will be used to report 
air quality for the site, and designate the other as the duplicate 
sampler. The paired samplers must each have the same designation 
number. Each duplicate sampler must be operated concurrently with 
its associated routine sampler at least once per week. The operation 
schedule should be selected so that the sampling days are 
distributed evenly over the year and over the seven days of the 
week. The every-6-day schedule used by many monitoring agencies is 
recommended. Report the measurements from both samplers at each 
collocated sampling site, including measurements falling below the 
limits specified in 5.3.1. The percent differences in measured 
concentration (g/m\3\) between the two collocated samplers 
are used to calculate precision as described in section 5.3.
    3.4  Accuracy of Manual Methods. The accuracy of manual sampling 
methods is assessed by auditing a portion of the measurement 
process. For particulate matter methods, the flow rate during sample 
collection is audited. For SO2 and NO2 methods, the 
analytical measurement is audited. For Pb methods, the flow rate and 
analytical measurement are audited.
    3.4.1  Methods for PM2.5 and PM10.
    3.4.1.1  Each calendar quarter, audit the flow rate of each 
PM2.5 sampler and audit at least 25 percent of the PM10 
samplers such

[[Page 65852]]

that each PM10 sampler is audited at least once per year. If 
there are fewer than four PM10 samplers within a reporting 
organization, randomly reaudit one or more samplers so that one 
sampler is audited each calendar quarter. Audit each sampler at its 
normal operating flow rate, using a flow rate transfer standard 
certified in accordance with section 2.3.3. The flow rate standard 
used for auditing must not be the same flow rate standard used to 
calibrate the sampler. However, both the calibration standard and 
the audit standard may be referenced to the same primary flow rate 
standard. The flow audit should be scheduled so as to avoid 
interference with a scheduled sampling period. Report the audit 
(actual) flow rate and the corresponding flow rate indicated by the 
sampler's normally used flow indicator. The percent differences 
between these flow rates are used to calculate accuracy as described 
in section 5.4.1.
    3.4.1.2  Great care must be used in auditing high-volume 
particulate matter samplers having flow regulators because the 
introduction of resistance plates in the audit flow standard device 
can cause abnormal flow patterns at the point of flow sensing. For 
this reason, the flow audit standard should be used with a normal 
filter in place and without resistance plates in auditing flow-
regulated high-volume samplers, or other steps should be taken to 
assure that flow patterns are not perturbed at the point of flow 
sensing.
    3.4.2  SO2 Methods.
    3.4.2.1  Prepare audit solutions from a working sulfite-
tetrachloromercurate (TCM) solution as described in section 10.2 of 
the SO2 Reference Method (appendix A of part 50 of this 
chapter). These audit samples must be prepared independently from 
the standardized sulfite solutions used in the routine calibration 
procedure. Sulfite-TCM audit samples must be stored between 0 and 5 
deg.C and expire 30 days after preparation.
    3.4.2.2  Prepare audit samples in each of the concentration 
ranges of 0.2-0.3, 0.5-0.6, and 0.8-0.9 g SO2/ml. 
Analyze an audit sample in each of the three ranges at least once 
each day that samples are analyzed and at least twice per calendar 
quarter. Report the audit concentrations (in g SO2/ml) 
and the corresponding indicated concentrations (in g 
SO2/ml). The percent differences between these concentrations 
are used to calculate accuracy as described in section 5.4.2.
    3.4.3  NO2 Methods. Prepare audit solutions from a working 
sodium nitrite solution as described in the appropriate equivalent 
method (see Reference 8). These audit samples must be prepared 
independently from the standardized nitrite solutions used in the 
routine calibration procedure. Sodium nitrite audit samples expire 
in 3 months after preparation. Prepare audit samples in each of the 
concentration ranges of 0.2-0.3, 0.5-0.6, and 0.8-0.9 g 
NO2/ml. Analyze an audit sample in each of the three ranges at 
least once each day that samples are analyzed and at least twice per 
calendar quarter. Report the audit concentrations (in g 
NO2/ml) and the corresponding indicated concentrations (in 
g NO2/ml). The percent differences between these 
concentrations are used to calculate accuracy as described in 
section 5.4.2.
    3.4.4  Pb Methods.
    3.4.4.1  For the Pb Reference Method (appendix G of part 50 of 
this chapter), the flow rates of the high-volume Pb samplers shall 
be audited as part of the TSP network using the same procedures 
described in Section 3.4.1. For agencies operating both TSP and Pb 
networks, 25 percent of the total number of high-volume samplers are 
to be audited each quarter.
    3.4.4.2  Each calendar quarter, audit the Pb Reference Method 
analytical procedure using glass fiber filter strips containing a 
known quantity of Pb. These audit sample strips are prepared by 
depositing a Pb solution on unexposed glass fiber filter strips of 
dimensions 1.9 cm by 20.3 cm (\3/4\ inch by 8 inch) and allowing 
them to dry thoroughly. The audit samples must be prepared using 
batches of reagents different from those used to calibrate the Pb 
analytical equipment being audited. Prepare audit samples in the 
following concentration ranges:

------------------------------------------------------------------------
                                                           Equivalent   
                                             Pb            ambient Pb   
                Range                  concentration,    concentration, 
                                      g/strip    g/m3 
---------------------------------------------------------------\1\------
1...................................           100-300           0.5-1.5
2...................................          600-1000          3.0-5.0 
------------------------------------------------------------------------
\1\ Equivalent ambient Pb concentration in g/m3 is based on    
  sampling at 1.7 m3/min for 24 hours on a 20.3 cm x 25.4 cm (8 inch x  
  10 inch) glass fiber filter.                                          

    3.4.4.3  Audit samples must be extracted using the same 
extraction procedure used for exposed filters.
    3.4.4.4  Analyze three audit samples in each of the two ranges 
each quarter samples are analyzed. The audit sample analyses shall 
be distributed as much as possible over the entire calendar quarter. 
Report the audit concentrations (in g Pb/strip) and the 
corresponding measured concentrations (in g Pb/strip) using 
unit code 77. The percent differences between the concentrations are 
used to calculate analytical accuracy as described in section 5.4.2.
    3.4.4.5  The accuracy of an equivalent Pb method is assessed in 
the same manner as for the reference method. The flow auditing 
device and Pb analysis audit samples must be compatible with the 
specific requirements of the equivalent method.

4. Reporting Requirements

    For each pollutant, prepare a list of all monitoring sites and 
their AIRS site identification codes in each reporting organization 
and submit the list to the appropriate EPA Regional Office, with a 
copy to AIRS-AQS. Whenever there is a change in this list of 
monitoring sites in a reporting organization, report this change to 
the Regional Office and to AIRS-AQS.
    4.1  Quarterly Reports. For each quarter, each reporting 
organization shall report to AIRS-AQS directly (or via the 
appropriate EPA Regional Office for organizations not direct users 
of AIRS) the results of all valid precision and accuracy tests it 
has carried out during the quarter. The quarterly reports of 
precision and accuracy data must be submitted consistent with the 
data reporting requirements specified for air quality data as set 
forth in Sec. 58.35(c). Each organization shall report all 
collocated measurements including those falling below the levels 
specified in section 5.3.1. Report results from invalid tests, from 
tests carried out during a time period for which ambient data 
immediately prior or subsequent to the tests were invalidated for 
appropriate reasons, and from tests of methods or analyzers not 
approved for use in SLAMS monitoring networks under Appendix C of 
this part. Such data should be flagged so that it will not be 
utilized for quantitative assessment of precision and accuracy.
    4.2  Annual Reports.
    4.2.1  When precision and accuracy estimates for a reporting 
organization have been calculated for all four quarters of the 
calendar year, EPA will calculate the properly weighted probability 
limits for precision and accuracy for the entire calendar year. 
These limits will then be associated with the data submitted in the 
annual SLAMS report required by Sec. 58.26.
    4.2.2  Each reporting organization shall submit, along with its 
annual SLAMS report, a listing by pollutant of all monitoring sites 
in the reporting organization.

5. Calculations for Data Quality Assessment

    Calculation of estimates of integrated precision and accuracy 
are carried out by EPA according to the following procedures. 
Reporting organizations should report the results of individual 
precision and accuracy tests as specified in sections 3 and 4 of 
this appendix even though they may elect to perform some or all of 
the calculations in this section on their own.
    5.1  Precision of Automated Methods. Estimates of the precision 
of automated methods are calculated from the results of biweekly 
precision checks as specified in section 3.1. At the end of each 
calendar quarter, an integrated precision probability interval for 
all SLAMS analyzers in the organization is calculated for each 
pollutant.
    5.1.1  Single Analyzer Precision.
    5.1.1.1  The percent difference (di) for each precision 
check is calculated using equation 1, where Yi is the 
concentration indicated by the analyzer for the I-th precision check 
and Xi is the known concentration for the I-th precision check.

[GRAPHIC] [TIFF OMITTED] TP13DE96.125


    5.1.1.2  For each analyzer, the quarterly average (dj) is 
calculated with equation 2, and the standard deviation (Sj) 
with equation 3, where n is the number of precision checks on the 
instrument made during the calendar quarter. For example, n should 
be 6 or 7 if precision checks are made biweekly during a quarter.

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[[Page 65853]]

[GRAPHIC] [TIFF OMITTED] TP13DE96.127



    5.1.2  Precision for Reporting Organization.
    5.1.2.1  For each pollutant, the average of averages (D) and the 
pooled standard deviation (Sa) are calculated for all analyzers 
audited for the pollutant during the quarter, using either equations 
4 and 5 or 4a and 5a, where k is the number of analyzers audited 
within the reporting organization for a single pollutant.
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[GRAPHIC] [TIFF OMITTED] TP13DE96.129

[GRAPHIC] [TIFF OMITTED] TP13DE96.130

[GRAPHIC] [TIFF OMITTED] TP13DE96.131


    5.1.2.2  Equations 4 and 5 are used when the same number of 
precision checks are made for each analyzer. Equations 4a and 5a are 
used to obtain a weighted average and a weighted standard deviation 
when different numbers of precision checks are made for the 
analyzers.
    5.1.2.3  For each pollutant, the 95 Percent Probability Limits 
for the precision of a reporting organization are calculated using 
equations 6 and 7.

Upper 95 Percent Probability

Limit=D+1.96 Sa    (6)

Lower 95 Percent Probability

Limit=D-1.96 Sa    (7)
    5.2  Accuracy of Automated Methods. Estimates of the accuracy of 
automated methods are calculated from the results of independent 
audits as described in section 3.2. At the end of each calendar 
quarter, an integrated accuracy probability interval for all SLAMS 
analyzers audited in the reporting organization is calculated for 
each pollutant. Separate probability limits are calculated for each 
audit concentration level in section 3.2.
    5.2.1  Single Analyzer Accuracy. The percentage difference 
(di) for each audit concentration is calculated using equation 
1, where Yi is the analyzer's indicated concentration 
measurement from the I-th audit check and Xi is the actual 
concentration of the audit gas used for the I-th audit check.
    5.2.2  Accuracy for Reporting Organization.
    5.2.2.1  For each audit concentration level of a particular 
pollutant, the average (D) of the individual percentage differences 
(di) for all n analyzers audited during the quarter is 
calculated using equation 8.
[GRAPHIC] [TIFF OMITTED] TP13DE96.132


    5.2.2.2  For each concentration level of a particular pollutant, 
the standard deviation (Sa) of all the individual percentage 
differences for all n analyzers audited during the quarter is 
calculated, using equation 9.
[GRAPHIC] [TIFF OMITTED] TP13DE96.133


    5.2.2.3  For reporting organizations having four or fewer 
analyzers for a particular pollutant, only one audit is required 
each quarter. For such reporting organizations, the audit results of 
two consecutive quarters are required to calculate an average and a 
standard deviation, using equations 8 and 9. Therefore, the 
reporting of probability limits shall be on a semiannual (instead of 
a quarterly) basis.
    5.2.2.4  For each pollutant, the 95 Percent Probability Limits 
for the accuracy of a reporting organization are calculated at each 
audit concentration level using equations 6 and 7.
    5.3  Precision of Manual Methods. Estimates of precision of 
manual methods are calculated from the results obtained from 
collocated samplers as described in section 3.3. At the end of each 
calendar quarter, an integrated precision probability interval for 
all collocated samplers operating in the reporting organization is 
calculated for each manual method network.
    5.3.1  Single Sampler Precision.
    5.3.1.1  At low concentrations, agreement between the 
measurements of collocated samplers, expressed as percent 
differences, may be relatively poor. For this reason, collocated 
measurement pairs are selected for use in the precision calculations 
only when both measurements are above the following limits:

TSP: 20 g/m3;
SO2: 45 g/m3;
NO2: 30 g/m3;
Pb: 0.15 g/m3;
PM10: 20 g/m3; and
PM2.5: 6 g/m3.

    5.3.1.2  For each selected measurement pair, the percent 
difference (di) is calculated, using equation 10,

[[Page 65854]]

[GRAPHIC] [TIFF OMITTED] TP13DE96.134



where Yi is the pollutant concentration measurement obtained 
from the duplicate sampler and Xi is the concentration 
measurement obtained from the primary sampler designated for 
reporting air quality for the site. For each site, the quarterly 
average percent difference (dj) is calculated from equation 2 
and the standard deviation (Sj) is calculated from equation 3, 
where n=the number of selected measurement pairs at the site.
    5.3.2  Precision for Reporting Organization.
    5.3.2.1  For each pollutant, the average percentage difference 
(D) and the pooled standard deviation (Sa) are calculated, 
using equations 4 and 5, or using equations 4a and 5a if different 
numbers of paired measurements are obtained at the collocated sites. 
For these calculations, the k of equations 4, 4a, 5 and 5a is the 
number of collocated sites.
    5.3.2.2  The 95 Percent Probability Limits for the integrated 
precision for a reporting organization are calculated using 
equations 11 and 12.

Upper 95 Percent Probability
[GRAPHIC] [TIFF OMITTED] TP13DE96.135


Lower 95 Percent Probability

Limit=D  1.96 Sa/2    (12)

    5.4  Accuracy of Manual Methods. Estimates of the accuracy of 
manual methods are calculated from the results of independent audits 
as described in section 3.4. At the end of each calendar quarter, an 
integrated accuracy probability interval is calculated for each 
manual method network operated by the reporting organization.
    5.4.1  Particulate Matter Samplers other than PM2.5 
(including reference method Pb samplers).
    5.4.1.1  Single Sampler Accuracy. For the flow rate audit 
described in Section 3.4.1, the percentage difference (di) for 
each audit is calculated using equation 1, where Xi represents 
the known flow rate and Yi represents the flow rate indicated 
by the sampler.
    5.4.1.2  Accuracy for Reporting Organization. For each type of 
particulate matter measured (e.g., TSP/Pb), the average (D) of the 
individual percent differences for all similar particulate matter 
samplers audited during the calendar quarter is calculated using 
equation 8. The standard deviation (Sa) of the percentage 
differences for all of the similar particulate matter samplers 
audited during the calendar quarter is calculated using equation 9. 
The 95 percent probability limits for the integrated accuracy for 
the reporting organization are calculated using equations 6 and 7. 
For reporting organizations having four or fewer particulate matter 
samplers of one type, only one audit is required each quarter, and 
the audit results of two consecutive quarters are required to 
calculate an average and a standard deviation. In that case, 
probability limits shall be reported semi-annually rather than 
quarterly.
    5.4.2  Analytical Methods for SO2, NO2, and Pb.
    5.4.2.1  Single Analysis-Day Accuracy. For each of the audits of 
the analytical methods for SO2, NO2, and Pb described in 
sections 3.4.2, 3.4.3, and 3.4.4, the percentage difference 
(dj) at each concentration level is calculated using equation 
1, where Xj represents the known value of the audit sample and 
Yj represents the value of SO2, NO2, or Pb indicated 
by the analytical method.
    5.4.2.1  Accuracy for Reporting Organization. For each 
analytical method, the average (D) of the individual percent 
differences at each concentration level for all audits during the 
calendar quarter is calculated using equation 8. The standard 
deviation (Sa) of the percentage differences at each 
concentration level for all audits during the calendar quarter is 
calculated using equation 9. The 95 percent probability limits for 
the accuracy for the reporting organization are calculated using 
equations 6 and 7.

6.0  Annual Operational Evaluation of PM2.5 Methods.

    All PM2.5 monitoring methods or analyzers used in SLAMS 
shall be evaluated annually, as described in this section, to 
quantitatively assess the quality of the SLAMS data being routinely 
produced. This evaluation is derived from the results of collocated 
PM2.5 measurements made at each monitoring station at least 6 
times per year and applies to both automated and manual methods. 
Individual samplers or monitors are screened for bias and excessive 
imprecision. Estimates of integrated measurement precision and 
accuracy, in the form of 95 percent probability limits, for each 
designated PM2.5 method are determined for each reporting 
organization and on a national basis. Reporting organizations are 
defined as in section 3 of this Appendix. The results of the latter 
evaluation shall be used to review instrument and reporting 
organization performance. The absolute value of the 95 percent 
probability limits on a national basis for each designated method 
must be within 15 percent for the method to maintain its reference 
or equivalent method designation.
    6.1  Operational field test audits. For each SLAMS PM2.5 
monitor, collocate a PM2.5 reference method sampler, referred 
to as an ``audit sampler,'' and operate it simultaneously with the 
SLAMS monitor at least 6 times per year. These collocated audits are 
required even for SLAMS PM2.5 monitors located at sites that 
have a collocated PM2.5 monitor as required under section 3.3 
of this appendix, unless the collocated monitor is a PM2.5 
reference method sampler and is a designated audit device as 
described in the Section 2.12 of the Quality Assurance Handbook 
(Reference 7). The collocated audit sampler shall be located between 
2 and 4 meters from the SLAMS monitor, with its inlet at the same 
height above ground as the inlet of the SLAMS monitor. Calibration 
and operation of the audit sampler and analysis of the audit sample 
filter shall be as specified in the sampler's operation or 
instruction manual and in general accordance with the guidance 
provided in Section 2.12 of Reference 7. Calibration and operation 
of the SLAMS monitor shall be the same as for its routine SLAMS 
operation, and it shall not receive any special or non-scheduled 
service immediately prior to, or specifically associated with, the 
collocated sample collection. The 6 or more collocated PM2.5 
measurement pairs shall be obtained at approximately equal intervals 
over the year, such as every other month, and shall be reported to 
the EPA as set forth in Section 4 of this Appendix for other 
precision and accuracy test results. All collocated measurements 
shall be reported, even those which might be considered invalid 
because of identified malfunctions or other problems occurring 
during the sample collection period. Collocated measurements shall 
be reported to EPA only for methods and analyzers approved for use 
in SLAMS monitoring under part 58 of this chapter. The EPA will 
calculate annual evaluations from the reported test measurements, as 
described in sections 6.2 and 6.3.
    6.2  Screening Test for Bias and Excessive Imprecision of 
Individual Monitors. This section describes a simple test, based on 
the

[[Page 65855]]

binomial distribution, that checks for gross bias or inadequate 
precision in the field operation of either the SLAMS monitor or the 
audit sampler. However, since the audit sampler is a reference method, 
the test results apply primarily to the SLAMS monitor. The test uses 
the collocated audit measurements described in section 6.1, and may be 
used with 4 to 12 measurement pairs.
    6.2.1  (1) For the annual evaluation, the EPA will calculate the 
relative percent difference (RPD) for each measurement pair obtained 
for the year as:
[GRAPHIC] [TIFF OMITTED] TP13DE96.137


where
C = the concentration measured by the SLAMS monitor, and
Caudit = the concentration measured by the audit sampler.
    (2) All collocated measurements will be used for this test, even 
those which might be considered invalid because of identified 
malfunctions or other problems occurring during the sample 
collection period.
    6.2.2  There are three situations that can develop from 
analyzing the collocated data:
    Situation A: All the RPD's are within 15% in absolute value. For 
situation A, the SLAMS monitor shows no indication of bias or 
inadequate precision and therefore passes this screening test.
    Situation B: Some or all of the RPD's are extreme in that they 
exceed 15% in absolute value, and the extreme RPD's all have the 
same sign (for example, -19, -21, -16). This may indicate a bias. 
For situation B, Table A-2 specifies the minimum number of extreme 
RPD's, all having the same sign, that indicates that the SLAMS 
monitor has a significant, unacceptable bias with respect to the 
audit reference method.
    Situation C: Some or all of the RPD's are extreme in that they 
exceed 15% in absolute value, and the extreme RPD's do not all have 
the same sign (for example, -17, +19, -18). This may indicate 
unacceptable precision. For situation C, Table A-2 specifies the 
minimum number of extreme RPD's, all not having the same sign, that 
indicate that the SLAMS monitor has excessive imprecision with 
respect to the audit reference method.
    6.2.3  If either bias (Situation B) or excessive imprecision 
(Situation C) is indicated by this screening test for a particular 
SLAMS monitor, the reporting organization will be notified by the 
EPA within 60 days after the end of the year that no monitors of the 
type (identified by its reference or equivalent method designation 
number) that failed the screening test shall be used for further 
SLAMS monitoring at any SLAMS site in the reporting organization 
unless and until the probable cause or causes of the test failure 
have been identified and corrected, the correction has been 
appropriately addressed in the applicable quality assurance plan, 
and the organization has received approval by the EPA Regional 
Office to resume use of monitors of the type identified for SLAMS 
purposes. General guidance in identifying and correcting common or 
typical types of such quality assurance problems for reference 
methods and Class I equivalent methods is provided in section 2.12 
of Reference 7 of this appendix.

Table A-2.--Table for Determining Bias or Excessive Inadequate Precision
                           for Screening Test                           
------------------------------------------------------------------------
                                                             Situation C
                                                Situation B    Number of
                                                  Number of    RPD's of 
                                                  RPD's of     absolute 
                                                  absolute    value over
                                                 value over    15%--all 
                                                  15%--all    not having
          Number of measurement pairs            having the    the same 
                                                same sign--   sign--that
                                                    that       indicate 
                                                  indicate    excessive 
                                                significant  imprecision
                                                bias of the     of the  
                                                   SLAMS        SLAMS   
                                                  monitor      monitor  
------------------------------------------------------------------------
4.............................................            2            3
5.............................................            2            3
6.............................................            3            4
7.............................................            3            4
8.............................................            3            4
9.............................................            3            5
10............................................            4            5
11............................................            4            5
12............................................            4            6
------------------------------------------------------------------------

    6.2.4  The basis of this test is as follows:
    6.2.4.1  For both instruments, the precision is assumed to be a 
percentage of the concentration being measured. The distributions of 
the instruments measurements are assumed to be normal, with an 
operating precision (1.96  x  standard deviation) of no more than 
15%. The relative percent difference (RPD) is then approximately 
normally distributed, with a standard deviation of about 15  x  
sqrt(2)/1.96 = 10.7%. Thus, the absolute value of RPD will exceed 
15% approximately 20% of the time.
    6.2.4.2  In the first situation (situation A), all the RPD's are 
within 15% in absolute value, and the performance is acceptable.
    6.2.4.3  When encountering a situation where RPD's are to one 
extreme or the other (situation B), one can set up the following 
hypotheses. Null Hypothesis: The mean measurements of both 
instruments are the same. Alternative Hypothesis: The mean of 
measurement of the SLAMS instrument is higher (lower) than the mean 
measurement of the audit instrument. The test of these hypotheses is 
based on the binomial distribution. Table A-2 gives the number of 
extreme values, for various numbers of measurement pairs, that would 
lead to a rejection of the null hypothesis in favor of the 
alternative hypothesis.
    6.2.4.4  When encountering the situation where RPD's are extreme 
in both directions (situation C), one can set up the following 
hypotheses. Null Hypothesis: The precisions of both instruments are 
less than or equal to 15% (2-sigma). Alternative Hypothesis: The 
precision of at least one instrument exceeds 15%. Again, the test is 
based on the binomial distribution, and Table A-2 gives the number 
of extreme values, for various numbers of measurement pairs, that 
would lead to a rejection of the null hypothesis in favor of the 
alternative hypothesis.
    6.2.4.5  These tests described above are stringent, using 
p=0.01, meaning that less than 1 time out of 100 would one expect to 
find the result randomly.
    6.2.4.6  As an example, suppose one takes 6 pairs of 
simultaneous measurements and finds that 4 of the 6 RPD's for the 
SLAMS monitor are greater than 15% and none of the remaining two 
RPD's are below--15%. Since there are 4 RPD's with absolute value 
above 15% and they all have the same sign (i.e. they are all above 
15%), this example would be situation B. Table A-2 indicates that 
for situation B with 6 measurement pairs, 3 or more extreme RPD's 
means that the SLAMS monitor is biased (in this case, higher) than 
the audit (reference) method.
    6.3  Integrated Precision and Accuracy for Reporting 
Organizations and for Specific Methods.
    This section describes how integrated estimates of monitoring 
data quality are calculated for specific monitoring methods (as 
identified by a unique reference or equivalent method designation 
number) on a national basis and for each reporting organization. 
These estimates are based on the collocated audit measurements 
described in section 6.1.
    6.3.1  Annual evaluation. Using the collocated measurement pair 
data, as described in Section 6.1 for the applicable year, the EPA 
shall determine the operating precision for each designated method, 
on a national basis and for each reporting organization, as follows:
    6.3.1.1.  For each monitoring station for which PM2.5 data 
has been reported to AIRS during the year, calculate the percent 
difference (di) for each measurement pair using equation 1 in 
section 5.1.1 of this Appendix, where Yi is the concentration 
measurement from the SLAMS monitor for the I-th audit measurement 
pair, Xi is the concentration measurement from the audit 
sampler. Include only stations at which at least 4 collocated 
measurement pairs are available for the year, and only measurement 
pairs in which Xi is above the limit for PM2.5 specified 
in section 5.3.1 of this Appendix.
    6.3.1.2  For each monitoring station for which PM2.5 data 
has been reported to AIRS, calculate the average (dj) and the 
standard deviation (Sj) for the year for each station at which 
the method is used for SLAMS monitoring, using equations 2 and 3

[[Page 65856]]

(respectively) in section 5.1.1 of this Appendix, where n is the 
number of measurement pairs reported for the year. Include only 
stations at which at least 4 collocated measurement pairs are 
available for the year.
    6.3.1.3  For each designated method and for each reporting 
organization, calculate the average of averages (D) and the pooled 
estimate of standard deviation (Sa), using equations 4a and 5a 
(respectively) of Section 5.1.2, where k in this case is the number 
of stations in the reporting organization at which the method is 
used for SLAMS monitoring (and at least 4 measurement pairs are 
reported). Call these estimates DR,M and SR,M, where R 
identifies the reporting organization and M identifies the 
designated method.
    6.3.1.4  For each designated method, calculate the average of 
averages (D) and the pooled standard deviation (Sa) at the 
national level using equations 4a and 5a (respectively) of Section 
5.1.2, where k in this case is the number of sites nationwide at 
which the method is used for SLAMS monitoring (and at least 4 
measurement pairs are reported). Call these estimates 
Dnational, M and Snational, M, where M identifies the 
designated method. A 95 percent confidence interval shall also be 
determined for each national pooled standard deviation.
    6.3.1.5  For each designated method, calculate the 95 percent 
probability limits for each reporting organization, using equations 
6 and 7 of Section 5.1.2, where D=DR,M and Sa=SR,M. 
Similarly, calculate the 95 percent probability limits for each 
method on a national basis, using equations 6 and 7 of Section 
5.1.2, where D=Dnational,M and Sa=Snational,M.
    Note: Pooling individual site estimates of precision across a 
reporting organization or across the nation using equation 5a 
assumes that the individual site estimates of precision using 
equation 3 are reasonably homogeneous across the year for a 
designated method.
    6.3.2  Reporting organization method operational performance. A 
summary of the results calculated in section 6.3.1.5 shall be 
reported annually to the appropriate EPA Regional Office. If the 
absolute value of either the upper or lower probability limit for a 
reporting organization calculated in section 6.3.1.5 for any 
designated method is found to be greater than 15 percent or 
substantially higher than the corresponding limits calculated for 
the method on the national basis, the reporting organization shall 
be identified and notified by the EPA that its quality assurance in 
the operation of the particular PM2.5 method may be inadequate. 
Each reporting organization so identified and notified must 
demonstrate, through an appropriate quality assurance plan or 
modified plan, that it will achieve better performance in future 
monitoring operations using the method. General guidance in 
identifying and correcting common or typical types of such quality 
assurance problems for reference methods and Class I equivalent 
methods is provided in section 2.12 of Reference 7 of this appendix.
    6.3.3  National method operational performance. If the absolute 
value of either the upper or lower probability limit calculated in 
section 6.3.1.5 for any designated method on a national basis is 
found to be greater than 15 percent, the method shall be deemed to 
have failed the annual operational performance assessment test. This 
result shall constitute a ground for cancellation of the reference 
or equivalent method in accordance with Sec. 53.11 of this chapter, 
and the EPA shall take the actions specified in that section within 
150 days.

References in Appendix A of Part 58

    1. Rhodes, R.C. Guideline on the Meaning and Use of Precision 
and Accuracy Data Required by 40 CFR part 58 appendices A and B. 
EPA-600/4-83/023. U.S. Environmental Protection Agency, Research 
Triangle Park, NC 27711, June, 1983.
    2. ``American National Standard--Specifications and Guidelines 
for Quality Systems for Environmental Data Collection and 
Environmental Technology Programs.'' ANSI/ASQC E4-1994. January 
1995. Available from American Society for Quality Control, 611 East 
Wisconsin Avenue, Milwaukee, WI 53202.
    3. ``EPA Requirements for Quality Management Plans.'' EPA QA/R-
2. August 1994. Available from U.S. Environmental Protection Agency, 
ORD Publications Office, Center for Environmental Research 
Information (CERI), 26 W. Martin Luther King Drive, Cincinnati, OH 
45268.
    4. ``EPA Requirements for Quality Assurance Project Plans for 
Environmental Data Operations.'' EPA QA/R-5. August 1994. Available 
from U.S. Environmental Protection Agency, ORD Publications Office, 
Center for Environmental Research Information (CERI), 26 W. Martin 
Luther King Drive, Cincinnati, OH 45268.
    5. ``Guidance for the Data Quality Objectives Process.'' EPA QA/
G-4. September 1994. Available from U.S. Environmental Protection 
Agency, ORD Publications Office, Center for Environmental Research 
Information (CERI), 26 W. Martin Luther King Drive, Cincinnati, OH 
45268.
    6. ``Quality Assurance Handbook for Air Pollution Measurement 
Systems, Volume 1--A Field Guide to Environmental Quality 
Assurance.'' EPA-600/R-94/038a. April 1994. Available from U.S. 
Environmental Protection Agency, ORD Publications Office, Center for 
Environmental Research Information (CERI), 26 W. Martin Luther King 
Drive, Cincinnati, OH 45268.
    7. ``Quality Assurance Handbook for Air Pollution Measurement 
Systems, Volume II--Ambient Air Specific Methods (Interim 
Edition).'' EPA-600/R-94/038b. April 1994. Available from U.S. 
Environmental Protection Agency, ORD Publications Office, Center for 
Environmental Research Information (CERI), 26 W. Martin Luther King 
Drive, Cincinnati, OH 45268. [Note: Section 2.12 of Volume II is 
currently under development and will not be available from the CERI 
address until it is published as an addition to EPA/600/R-94/038b. 
Prepublication draft copies of section 2.12 will be available from 
Department E (MD-77B), U.S. EPA, Research Triangle Park, NC 27711, 
or from the contact identified at the beginning of this proposed 
rule].
    8. ``List of Designated Reference and Equivalent Methods.'' 
Available from U.S. Environmental Protection Agency, National 
Exposure Research Laboratory, Quality Assurance Branch, MD-77B, 
Research Triangle Park, NC 27711.
    9. Technical Assistance Document for Sampling and Analysis of 
Ozone Precursors. Atmospheric Research and Exposure Assessment 
Laboratory, U.S. Environmental Protection Agency, Research Triangle 
Park, NC 27711. EPA 600/8-91-215. October 1991.
    10. ``EPA Traceability Protocol for Assay and Certification of 
Gaseous Calibration Standards.'' EPA-600/R-93/224. September 1993. 
Available from U.S. Environmental Protection Agency, ORD 
Publications Office, Center for Environmental Research Information 
(CERI), 26 W. Martin Luther King Drive, Cincinnati, OH 45268.
    11. Paur, R.J. and F.F. McElroy. Technical Assistance Document 
for the Calibration of Ambient Ozone Monitors. EPA-600/4-79-057. 
U.S. Environmental Protection Agency, Research Triangle Park, NC 
27711, September, 1979.
    12. McElroy, F.F. Transfer Standards for the Calibration of 
Ambient Air Monitoring Analyzers for Ozone. EPA-600/4-79-056. U.S. 
Environmental Protection Agency, Research Triangle Park, NC 27711, 
September, 1979.

Tables to Appendix A of Part 58

                                Table A-1.--Minimum Data Assessment Requirements                                
----------------------------------------------------------------------------------------------------------------
                                                                                                  Parameters    
             Method                Assessment method       Coverage        Minimum frequency       reported     
----------------------------------------------------------------------------------------------------------------
Precision:                                                                                                      
    Automated methods for SO2,    Response check at   Each analyzer.....  Once per 2 weeks..  Actual            
     NO2, O3, and CO.              concentration                                               concentration \2\
                                   between .08 and                                             and measured     
                                   .10 ppm (8 & 10                                             concentration \3\
                                   ppm for CO) \2\.                                            .                

[[Page 65857]]

                                                                                                                
    Manual methods: All methods   Collocated          1 site for 1-5      Once per week.....  Two concentration 
     except PM25.                  samplers.           sites; 2 sites                          measurements.    
                                                       for 6-20 sites; 3                                        
                                                       sites >20 sites;                                         
                                                       (sites with                                              
                                                       highest conc.).                                          
    PM25 methods................  Collocated          1 site for 1-10     Once per week.....  Two concentration 
                                   samplers.           sites; 2 sites                          measurements.    
                                                       for 11-20 sites;                                         
                                                       3 sites >20                                              
                                                       sites; (sites                                            
                                                       with highest                                             
                                                       conc.).                                                  
Accuracy:                                                                                                       
    Automated methods for SO2,    Response check at   1. Each analyzer;   1. Once per year;   Actual            
     NO2, O3, and CO.              .03-.08 ppm,1,2     2. 25% of           2. Each calendar    concentration \2\
                                   .15-.20 ppm;1,2     analyzers (at       quarter.            and measured     
                                   .35-.45 ppm;1,2     least 1).                               (indicated)      
                                   ,80-.90 ppm;1,2                                             concentration \3\
                                   (if applicable).                                            for each level.  
    Manual methods for SO2, and   Check of            Analytical system.  Each day samples    Actual            
     NO2.                          analytical                              are analyzed, at    concentration and
                                   procedure with                          least twice per     measured         
                                   audit standard                          quarter.            (indicated)      
                                   solutions.                                                  concentration for
                                                                                               each audit       
                                                                                               solution.        
    TSP, PM10...................  Check of sampler    1. Each sampler;    1. Once per year;   Actual flow rate  
                                   flow rate.          2. 25% of           2. Each calendar    and flow rate    
                                                       samplers (at        quarter.            indicated by the 
                                                       least 1).                               sampler.         
    PM25........................  1. Check of         1. Each sampler,    1. Minimum of       1. Actual flow    
                                   sampler flow rate.  all locations.      every calendar      rate and flow    
                                                                           quarter, 4 checks   rate indicated by
                                                                           per year.           sampler.         
                                  2. Audit with       2. Each sampler,    2. Minimum of       2. Particle mass  
                                   reference method.   all locations.      every other         concentration    
                                                                           month, 6            indicated by     
                                                                           measurements per    sampler and by   
                                                                           year.               audit reference  
                                                                                               sampler.         
    Lead........................  1. Check of         1. Each sampler...  1. Include with     1. Same as for    
                                   sampler flow rate                       TSP.                TSP.             
                                   as TSP;.                                                                     
                                  2. Check of         2. Analytical       2. Each quarter...  2. Actual         
                                   analytical system   system.                                 concentration and
                                   with Pb audit                                               measured         
                                   strips.                                                     (indicated)      
                                                                                               concentration of 
                                                                                               audit samples    
                                                                                               (g Pb/  
                                                                                               strip).          
----------------------------------------------------------------------------------------------------------------
\1\ Concentration times 100 for CO.                                                                             
\2\ Effective concentration for open path analyzers.                                                            
\3\ Corrected concentration, if applicable, for open path analyzers.                                            

Appendix C--[Amended]

    15. Appendix C, is amended by revising section 2.2 and adding 
sections 2.2.1 through 2.2.2.2 to read as follows:

2.2  Substitute PM samplers.

    2.2.1  Substitute PM10 samplers.
    2.2.1.1  For purposes of showing compliance with the NAAQS for 
particulate matter, a high volume TSP sampler described in Appendix 
B of part 50 of this chapter may be used in a SLAMS in lieu of a 
PM10 monitor as long as the ambient concentrations of particles 
measured by the TSP sampler are below the PM10 NAAQS. If the 
TSP sampler measures a single value that is higher than the 
PM10 24-hour standard, or if the annual average of its 
measurements is greater than the PM10 annual standard, the TSP 
sampler operating as a substitute PM10 sampler must be replaced 
with a PM10 monitor. For a TSP measurement above the 24-hour 
standard, the TSP sampler should be replaced with a PM10 
monitor before the end of the calendar quarter following the quarter 
in which the high concentration occurred. For a TSP annual average 
above the annual standard, the PM10 monitor should be operating 
by June 30 of the year following the exceedance.
    2.2.1.2  In order to maintain historical continuity of ambient 
particulate matter trends and patterns for PM10 NAMS that were 
previously TSP NAMS, the TSP high volume sampler must be operated 
concurrently with the PM10 monitor for a one-year period 
beginning with the PM10 NAMS start-up date. The operating 
schedule for the TSP sampler must be at least once every six days 
regardless of the PM10 sampling frequency.
    2.2.2  Substitute PM2.5 samplers.
    2.2.2.1  For purposes of showing compliance with the NAAQS for 
particulate matter, a PM10 monitor designated as a reference or 
equivalent method for PM10 under part 53 of this chapter may be 
used in a SLAMS in lieu of a PM2.5 monitor as long as the 
ambient concentration of particles measured by the PM10 monitor 
is below the PM2.5 NAAQS. If the PM10 monitor measures a 
single value that is higher than the PM2.5 24-hour standard, or 
the annual average of its measurements is greater than the 
PM2.5 annual standard, the PM10 monitor operating as a 
substitute PM2.5 monitor must be replaced with a PM2.5 
monitor. For a PM10 measurement above the 24-hour PM2.5 
standard, the PM10 monitor should be replaced with a PM2.5 
monitor before the end of the calendar quarter following the quarter 
in which the high concentration occurred. For a PM10 annual 
average above the annual PM2.5 standard, the PM2.5 monitor 
should be operating by June 30 of the year following the exceedance.
    2.2.2.2  In order to maintain historical continuity of ambient 
particulate matter trends and patterns for PM2.5 NAMS that were 
previously PM10 NAMS, the PM10 monitor must be operated 
concurrently with the PM2.5 monitor for a one-year period 
beginning with the PM2.5 NAMS start-up date. The operating 
schedule for the PM10 monitor must be at least once every six 
days regardless of the PM2.5 sampling frequency.

    16. Appendix C amended by adding a new sections 2.4 through 2.4.6 
to read as follows:

    2.4  Approval of non-designated PM2.5 methods operated at 
specific individual sites. A method for PM2.5 that has not been 
designated as a reference or equivalent method as defined in 
Sec. 50.1 of this chapter may be approved for use for purposes of 
section 2.1 of this Appendix at a particular SLAMS under the 
following stipulations.
    2.4.1  The method must be demonstrated to meet the comparability 
requirements (except as provided in this section 2.4.1) set forth in 
Sec. 53.34 of this chapter in each of the four seasons at the site 
at which it is intended to be used. For purposes of this

[[Page 65858]]

section 2.4.1, the requirements of 40 CFR 53.34 shall be modified as 
follows:
    2.4.1.1  The method shall be tested at the site at which it is 
intended to be used, and there shall be no requirement for tests at 
any other test site.
    2.4.1.2  For purposes of this section 2.4, the seasons shall be 
defined as follows: spring shall be the months of March, April, and 
May; summer shall be the months of June, July, and August; fall 
shall be the months of September, October, and November; and winter 
shall be the months of December, January, and February.
    2.4.1.3  No PM10 samplers shall be required for the test, 
as determination of the PM2.5/PM10 ratio at the test site 
shall not be required.
    2.4.1.4  The specifications given in Table C-4 of part 53 of 
this chapter for Class I methods shall apply, except that there 
shall be no requirement for any minimum number of sample sets with 
Rj above 40 g/m\3\ for 24-hour samples or above 30 
g/m\3\ for 48-hour samples.
    2.4.2  The monitoring agency wishing to use the method must 
develop and implement appropriate quality assurance procedures for 
the method.
    2.4.3  The monitoring agency wishing to use the method must 
develop and implement appropriate procedures for assessing and 
reporting the precision and accuracy of the method comparable to the 
procedures set forth in Appendix A of this part for designated 
reference and equivalent methods.
    2.4.4  The assessment of network operating precision using 
collocated measurements with reference method ``audit'' samplers 
required under section 6 of Appendix A of this section shall be 
carried out semi-annually rather than annually (i.e., monthly audits 
with assessment determinations each 6 months).
    2.4.5  Requests for approval under this section 2.4 must meet 
the general submittal requirements of sections 2.7.1 and 2.7.2.1 of 
this appendix and must include the requirements in sections 2.4.5.1 
through 2.4.5.7 of this appendix.
    2.4.5.1  A clear and unique description of the site at which the 
method or sampler will be used and tested, and a description of the 
nature or character of the site and the particulate matter that is 
expected to occur there.
    2.4.5.2  A detailed description of the method and the nature of 
the sampler or analyzer upon which it is based.
    2.4.5.3  A brief statement of the reason or rationale for 
requesting the approval.
    2.4.5.4  A detailed description of the quality assurance 
procedures that have been developed and that will be implemented for 
the method.
    2.4.5.5  A detailed description of the procedures for assessing 
the precision and accuracy of the method that will be implemented 
for reporting to AIRS.
    2.4.5.6  Test results from the comparability tests required 
above.
    2.4.5.7  Such further supplemental information as may be 
necessary or helpful to support the required statements and test 
results.
    2.4.6  Within 120 days after receiving a request for approval of 
the use of a method at a particular site under this section 2.4 and 
such further information as may be requested for purposes of the 
decision, the Administrator will approve or disapprove the method by 
letter to the person or agency requesting such approval.

    17. Appendix C is amended by adding a new section 2.5 to read as 
follows:

    2.5  Approval of non-designated methods under Sec. 58.13(f). An 
automated (continuous) method for PM2.5 that is not designated 
as either a reference or equivalent method as defined in Sec. 50.1 
of this chapter may be approved under Sec. 58.13(f) for use at a 
SLAMS for the limited purposes of Sec. 58.13(f). Such an analyzer 
that is approved for use at a SLAMS under Sec. 58.13(f), identified 
as correlated acceptable continuous (CAC) monitors, shall not be 
considered a reference or equivalent method as defined in Sec. 50.1 
of this chapter by virtue of its approval for use under 
Sec. 58.13(f), and the PM2.5 monitoring data obtained from such 
a monitor shall not be otherwise used for purposes of part 50 of 
this chapter.

    18. Appendix C is amended by revising the section 2.7.1 to read as 
follows:

    2.7.1  Requests for approval under sections 2.4, 2.6.2, or 2.8 
must be submitted to: Director, National Exposure Assessment 
Laboratory, Department E, (MD-77B), U.S. Environmental Protection 
Agency, Research Triangle Park, North Carolina 27711.

    19. Appendix C is amended by adding a new section 2.9 to read as 
follows:

    2.9  Use of IMPROVE Samplers at a SLAMS. ``IMPROVE'' samplers 
may be used in SLAMS for monitoring of regional background 
concentrations of fine particulate matter. The IMPROVE samplers were 
developed for use in the Interagency Monitoring of Protected Visual 
Environments (IMPROVE) network to characterize all of the major 
components and many trace constituents of the particulate matter 
that impair visibility in Federal Class I Areas. These samplers are 
routinely operated at about 70 locations in the United States. 
IMPROVE samplers consist of four sampling modules that are used to 
collect twice weekly 24-hour duration simultaneous samples. Modules 
A, B, and C collect PM2.5 on three different filter substrates 
that are compatible with a variety of analytical techniques, and 
module D collects a PM10 sample. PM2.5 mass and elemental 
concentrations are determined by analysis of the 25mm diameter 
stretched Teflon filters from module A. More complete descriptions 
of the IMPROVE samplers and the data they collect are available 
elsewhere (References 5.2, 5.3, and 5.4 of this Appendix).

    20. Appendix C, section 6.0 amended by adding references, 4 through 
6 to read as follows:

6.0  References

* * * * *
    4. Eldred, R.A., Cahill, T.A., Wilkenson, L.K., et al., 
``Measurements of fine particles and their chemical components in 
the IMPROVE/NPS networks,'' in ``Transactions of the International 
Specialty Conference on Visibility and Fine Particles,'' Air and 
Waste Management Association: Pittsburgh, PA, 1990; pp 187-196.
    5. Sisler, J.F., Huffman, D., and Latimer, D.A.; ``Spatial and 
temporal patterns and the chemical composition of the haze in the 
United States: An analysis of data from the IMPROVE network, 1988-
1991,'' ISSN No. 0737-5253-26, National Park Service, Ft. Collins, 
CO, 1993.
    6. Eldred, R.A., Cahill, T.A., Pitchford, M., and Malm, W.C.; 
``IMPROVE--a new remote area particulate monitoring system for 
visibility studies,'' Proceedings of the 81st Annual Meeting of the 
Air Pollution Control Association, Dallas, Paper 88-54.3, 1988.

Appendix D--[Amended]

    21. In Appendix D the first three paragraphs and Table 1 of section 
1 are revised as follows:

1. SLAMS Monitoring Objectives and Spatial Scales

    The purpose of this appendix is to describe monitoring 
objectives and general criteria to be applied in establishing the 
State and Local Air Monitoring Stations (SLAMS) networks and for 
choosing general locations for new monitoring stations. It also 
describes criteria for determining the number and location of 
National Air Monitoring Stations (NAMS), Photochemical Assessment 
Monitoring Stations (PAMS), and core Stations for PM2.5. These 
criteria will also be used by EPA in evaluating the adequacy of the 
SLAMS/NAMS/PAMS and core PM2.5 networks.
    The network of stations which comprise SLAMS should be designed 
to meet a minimum of six basic monitoring objectives. These basic 
monitoring objectives are:
    (1) To determine highest concentrations expected to occur in the 
area covered by the network;
    (2) To determine representative concentrations in areas of high 
population density;
    (3) To determine the impact on ambient pollution levels of 
significant sources or source categories;
    (4) To determine general background concentration levels;
    (5) To determine the extent of Regional pollutant transport 
among populated areas; and in support of secondary standards; and
    (6) To determine the welfare-related impacts in more rural and 
remote areas (such as visibility impairment and effects on 
vegetation).
    It should be noted that this appendix contains no criteria for 
determining the total number of stations in SLAMS networks, except 
that a minimum number of lead SLAMS and PM2.5 are prescribed 
and the minimal network introduced in 58.20 is explained. The 
optimum size of a particular SLAMS network involves trade offs among 
data needs and available resources which EPA believes can best be 
resolved during the network design process.
* * * * *

[[Page 65859]]



     Table 1.--Relationship Among Monitoring Objectives and Scale of    
                           Representativeness                           
------------------------------------------------------------------------
           Monitoring objective               Appropriate siting scales 
------------------------------------------------------------------------
Highest concentration.....................  Micro, Middle, neighborhood 
                                             (sometimes urbana).        
                                            Neighborhood, urban.        
Population................................  Micro, middle, neighborhood.
Source impact.............................  Neighborhood, urban,        
                                             regional.                  
General/background........................  Urban/regional.             
Regional transport........................  ............................
Welfare-related impacts...................  Urban/regional.             
------------------------------------------------------------------------
a Urban denotes a geographic scale applicable to both cities and rural  
  areas.                                                                

* * * * *
    22. In Appendix D, section 2 is amended by revising the second 
paragraph and adding a new paragraph to the end of the section before 
section 2.1 to read as follows:

2. SLAMS Network Design Procedures

* * * * *
    The discussion of scales in sections 2.3 through 2.8 does not 
include all of the possible scales for each pollutant. The scales 
which are discussed are those which are felt to be most pertinent 
for SLAMS network design.
* * * * *
    Information such as emissions density, housing density, 
climatological data, geographic information, traffic counts, and the 
results of modeling will be useful in designing regulatory networks. 
Air pollution control agencies have shown the value of screening 
studies, such as intensive studies conducted with portable samplers, 
in designing networks. In many cases, in selecting sites for core 
PM2.5 or carbon monoxide SLAMS, and for defining the boundaries 
of PM2.5 spatial averaging zone, air pollution control agencies 
will benefit from using such studies to evaluate the spatial 
distribution of pollutants.
* * * * *
    23. Section 2.8 is revised as follows:

2.8  Particulate Matter Design Criteria for SLAMS

    As with other pollutants measured in the SLAMS network, the 
first step in designing the particulate matter network is to collect 
the necessary background information. Various studies in References 
11, 12, 13, 14, 15, and 16 of this appendix have documented the 
major source categories of particulate matter and their contribution 
to ambient levels in various locations throughout the country.
    2.8.0.1  Sources of background information would be regional and 
traffic maps, and aerial photographs showing topography, 
settlements, major industries and highways. These maps and 
photographs would be used to identify areas of the type that are of 
concern to the particular monitoring objective. After potentially 
suitable monitoring areas for particulate matter have been 
identified on a map, modeling may be used to provide an estimate of 
particulate matter concentrations throughout the area of interest. 
After completing the first step, existing particulate matter 
stations should be evaluated to determine their potential as 
candidates for SLAMS designation. Stations meeting one or more of 
the six basic monitoring objectives described in section 1 of this 
appendix must be classified into one of the five scales of 
representativeness (micro, middle, neighborhood, urban and regional) 
if the stations are to become SLAMS. In siting and classifying 
particulate matter stations, the procedures in reference 17 should 
be used.
    2.8.0.2  The most important spatial scales to effectively 
characterize the emissions of particulate matter from both mobile 
and stationary sources are the middle and neighborhood scales. For 
purposes of establishing monitoring stations to represent large 
homogenous areas other than the above scales of representativeness 
and to characterize Regional transport, urban or regional scale 
stations would also be needed.
    2.8.0.3  Microscale--This scale would typify areas such as 
downtown street canyons and traffic corridors where the general 
public would be exposed to maximum concentrations from mobile 
sources. In some circumstances, the microscale is appropriate for 
particulate stations; core SLAMS on the microscale should, however, 
be limited to urban sites that are representative of long-term human 
exposure and of many such microenvironments in the area. In general, 
microscale particulate matter sites should be located near inhabited 
buildings or locations where the general public can be expected to 
be exposed to the concentration measured. Emissions from stationary 
sources such as primary and secondary smelters, power plants, and 
other large industrial processes may, under certain plume 
conditions, likewise result in high ground level concentrations at 
the microscale. In the latter case, the microscale would represent 
an area impacted by the plume with dimensions extending up to 
approximately 100 meters. Data collected at microscale stations 
provide information for evaluating and developing ``hot spot'' 
control measures. Unless these sites are indicative of population-
oriented monitoring, they may be more appropriately classified as 
SPMs.
    2.8.0.4  Middle Scale--Much of the measurement of short-term 
public exposure to particulate matter is on this scale and on the 
neighborhood scale; core SLAMS especially should represent 
community-wide air pollution. People moving through downtown areas, 
or living near major roadways, encounter particles that would be 
adequately characterized by measurements of this spatial scale. 
Thus, measurements of this type would be appropriate for the 
evaluation of possible short-term public health effects of 
particulate matter pollution. This scale also includes the 
characteristic concentrations for other areas with dimensions of a 
few hundred meters such as the parking lot and feeder streets 
associated with shopping centers, stadia, and office buildings. In 
the case of PM10, unpaved or seldom swept parking lots 
associated with these sources could be an important source in 
addition to the vehicular emissions themselves.
    2.8.0.5  Neighborhood Scale--Measurements in this category would 
represent conditions throughout some reasonably homogeneous urban 
subregion with dimensions of a few kilometers and of generally more 
regular shape than the middle scale. Homogeneity refers to the 
particulate matter concentrations, as well as the land use and land 
surface characteristics. Much of the PM2.5 exposures are 
expected to be associated with this scale of measurement. In some 
cases, a location carefully chosen to provide neighborhood scale 
data would represent not only the immediate neighborhood but also 
neighborhoods of the same type in other parts of the city. Stations 
of this kind provide good information about trends and compliance 
with standards because they often represent conditions in areas 
where people commonly live and work for periods comparable to those 
specified in the NAAQS. This category also may include industrial 
and commercial neighborhoods especially in districts of diverse land 
use where residences are interspersed.
    2.8.0.6  Neighborhood scale data could provide valuable 
information for developing, testing, and revising models that 
describe the larger-scale concentration patterns, especially those 
models relying on spatially smoothed emission fields for inputs. The 
neighborhood scale measurements could also be used for neighborhood 
comparisons within or between cities. This is the most likely scale 
of measurements to meet the needs of planners.
    2.8.0.7  Urban Scale--This class of measurement would be made to 
characterize the particulate matter concentration over an entire 
metropolitan or rural area ranging in size from 4 to 50 km. Such 
measurements would be useful for assessing trends in area-wide air 
quality, and hence, the effectiveness of large scale air pollution 
control strategies.
    2.8.0.8  Regional Scale--These measurements would characterize 
conditions over areas with dimensions of as much as hundreds of 
kilometers. As noted earlier, using representative conditions for an 
area implies some degree of homogeneity in that area. For this 
reason, regional scale measurements would be most applicable to 
sparsely populated areas with reasonably uniform ground cover. Data 
characteristics of this scale would provide information about larger 
scale processes of particulate matter emissions, losses and 
transport. Especially in the case of PM2.5, transport 
contributes to particulate concentrations and may affect multiple 
urban and State entities with large populations such as in the 
Eastern United States. Development of effective pollution control 
strategies requires an understanding at regional geographical scales 
of the emission sources and atmospheric processes that are 
responsible for elevated PM2.5 levels and may also be 
associated with elevated ozone and regional haze.

    24. New sections 2.8.1, 2.8.2, 2.8.3, and 2.8.4 are added after 
Section 2.8 to read as follows:

[[Page 65860]]

2.8.1  Monitoring Planning Areas and Spatial Averaging Zones

    2.8.1.1  Monitoring planning areas (MPA's) and spatial averaging 
zones (SAZ's) shall be used to conform to the population-oriented, 
spatial averaging approach used for the PM2.5 NAAQS given in 40 
CFR Part 50. MPA's are required to include all metropolitan 
statistical areas (MSA's) with population greater than 500,000, and 
all other areas determined to be in violation of the PM2.5 
NAAQS.1 Although not required, MPA's should generally be 
designated to also include all MSA's with population greater than 
250,000 which have measured or modeled PM2.5 concentrations 
greater than 80 percent of the PM2.5 NAAQS. Monitoring planning 
areas for other designated parts of the State are optional.
---------------------------------------------------------------------------

    \1\ The boundaries of MPA's do not have to necessarily 
correspond to those of MSA's and existing intra or interstate air 
pollution planning districts may be utilized.
---------------------------------------------------------------------------

    2.8.1.2  The SAZs shall define the area within which monitoring 
data will be averaged for comparison with the annual PM2.5 
NAAQS. This approach is directly related to epidemiological studies 
used as the basis for the PM2.5 NAAQS. A SAZ should 
characterize an area of relatively similar annual average air 
quality (e.g., the annual average concentrations at individual sites 
should not exceed the spatial average by more than +/- 20 percent) 
and exhibit similar day to day variability (e.g., the monitoring 
sites should not have low correlations, say less than 0.8). 
Moreover, the entire SAZ should principally be affected by the same 
major emission sources of particulate matter.
    2.8.1.3  Each monitoring planning area shall have at least one 
spatial averaging zone, which may or may not cover the entire MPA. 
In metropolitan statistical areas (MSA's) for which MPA's are 
required, the SAZ's shall completely cover the entire MSA. 
Exceptions to the requirement are allowed (say for areas with low 
population density) provided that it receives approval from the 
appropriate EPA Regional Administrator. In MPA's for other areas, 
the SAZ's are not required to completely cover the entire MPA. All 
MPA's and SAZ's shall be defined on the basis of existing, 
delineated mapping data limited to State boundaries, county 
boundaries, zip codes, census blocks, or census block groups; 
however, SAZ's shall not overlap in their geographical coverage.
    2.8.1.4  Spatial averaging zones should generally include a 
minimum of 250,000 and not more than two million population, but all 
areas in the ambient air may become a spatial averaging zone. The 
SAZ should emphasize population that spends a substantial portion of 
time within the zone to reflect exposure from multiple spatial 
locations, but does not need to account for all day-night population 
shifts. Consequently, large MSA's with population greater than one 
million should be subdivided into smaller portions, such as 
counties, to better reflect the variability in exposure to the 
average population for large numbers of people.
    2.8.1.5  A SAZ can be represented by a single monitoring 
location, but in most cases multiple locations will be needed. For 
example, a single monitor may not be adequate to characterize the 
average air quality in a large geographic area; in large areas of 
relatively low population or population density, population centers 
and monitoring sites may be geographically disjoint. In such cases, 
the spatial representativeness of the monitoring site should be 
considered in defining the SAZ boundaries. Until more monitoring 
stations are established, the monitored air quality in areas outside 
of SAZ's is unknown. Accordingly, a station that is established in 
the ambient air outside the boundaries of a SAZ but that is in or 
near a populated area, meets siting criteria, and produces quality-
assured data (i.e., meets the requirements of Part 58, 58.13, and 
Appendices A, C, and E) can also be presumed to produce data that is 
eligible for comparison to both the 24-hour and annual NAAQS for 
PM2.5 and to represent some zone. At the discretion of the 
responsible air pollution control agency, such a zone should be 
defined as a SAZ during the annual network review. In this way, the 
network coverage of the population can be gradually improved.

2.8.2  PM2.5 Monitoring Sites within the State PM Monitoring Plan

    2.8.2.0.1  The minimum required number and type of monitoring 
sites and sampling requirements for PM2.5 are based on 
monitoring planning areas and spatial averaging zones for each MPA, 
which must be included in a monitoring plan and proposed by the 
States in accordance with Sec. 58.20.
    2.8.2.0.2  As stated in Sec. 58.15, comparisons to the 
PM2.5 NAAQS may be based on data from SPMs in addition to SLAMS 
(including NAMS, core SLAMS and collocated PM2.5 sites at 
PAMS), which meet the requirements of part 58, 58.13, and appendices 
A, C and E, which are population-oriented and which are included in 
the monitoring plan. Figure 1 of this Appendix shows a conceptual 
(Venn) diagram illustrating which PM2.5 sites in an MPA and SAZ 
are eligible for comparison with the PM2.5 NAAQS. Special 
purpose monitors which meet part 58 requirements will be exempt from 
NAAQS comparisons with the PM2.5 NAAQS for 3 years following 
promulgation of the PM2.5 NAAQS to encourage PM2.5 
monitoring initially. After this time, however, any SPM which 
records a violation of the PM2.5 NAAQS must be seriously 
considered as a potential SLAMS site during the annual SLAMS network 
review in accordance with Sec. 58.25. If such SPM's are not 
established as a SLAMS the agency must document in its annual 
report, the technical basis for excluding it as a SLAMS.

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    2.8.2.0.3  Figure 1 is intended to show the relationship between 
NAAQS eligible sites to the entire monitoring network. Sites 
eligible for comparison to both standards and only the daily (i.e, 
24-hour) standard are shown. The diagram applies to all the sites in 
a Monitoring Planning Area including special purpose, industrial as 
well as the NAMS/SLAMS/Core networks. The sub-areas shown do not 
necessarily represent contiguous geographic regions.
    2.8.2.0.4  All sites eligible for PM2.5 NAAQS comparisons 
would be designated ``B'' or ``D'', and all other sites would be 
designated ``O.'' Sites ``B'' and ``D'' must be NAMS/SLAMS or other 
population-oriented sites, be included in the State's Monitoring 
Plan and meet requirements of Part 58 .13 and Appendices A, C and E. 
The codes ``B,'' ``D'' and ``O'' would become new pollutant specific 
codes on the AIRS monitoring site file to identify PM-2.5 sites 
eligible for NAAQS comparisons. The codes could distinguish between 
State submitted codes and those receiving EPA Regional Office 
approval (as currently done with Exceptional Event data codes). This 
will reflect EPA review and approval of the site information 
presented in the State's annual Monitoring Plan.
    2.8.2.0.5  Within each MPA and SAZ, the responsible air 
pollution control agency shall install core SLAMS, other required 
SLAMS and as many PM2.5 stations judged necessary to satisfy 
the SLAMS requirements and monitoring objectives of this appendix.
    2.8.2.1  Core Monitoring Stations for PM2.5
    Core monitoring stations or sites are a subset of the SLAMS 
network for PM2.5 for which more frequent (daily) sampling of 
PM2.5 is required. These core sites fall into three categories:
    Population-oriented SLAMS monitors, background and transport 
sites, and sites to be collocated at PAMS.
    2.8.2.1.2  Within each monitoring planning area, the responsible 
air pollution control agency shall install:
    (a) At least two population-oriented core stations for 
PM2.5, unless exempted by the Regional Administrator, including 
at least one station in a population oriented area of expected 
maximum concentration; (b) At least one station in an area of poor 
air quality and representative of maximum population impact and (c) 
At least one additional core monitor collocated at a PAMS site if 
the MPA is also a PAMS area.2
---------------------------------------------------------------------------

    \2\ The core monitor to be collocated at a PAMS site shall not 
be considered a part of the PAMS as described in section 4 of this 
appendix, but shall instead be considered to be a component of the 
particular MPA PM2.5 network
---------------------------------------------------------------------------

    2.8.2.1.3  The site situated in the area of expected maximum 
concentration is analogous to NAMS ``category a.'' 3 This will 
henceforth be termed a category a core SLAMS site. The site located 
in the area of poor air quality with high population density or 
representative of maximum population impact is analogous to NAMS, 
``category b.'' 4 This second site will be called a category b 
core SLAMS site.
---------------------------------------------------------------------------

    \3\ The measured maximum concentrations at core population-
oriented sites should be consistent with the averaging time of the 
NAAQS. Therefore, sites only with high concentrations for shorter 
averaging times (say 1-hour) should not be core SLAMS monitors and 
may in fact be more appropriately designated special purpose 
monitors.
    \4\ Population-oriented sites are representative of residential, 
recreational and business locations where people are present for a 
substantial portion of the NAAQS averaging time period or locations 
indicative of ambient air to which the population can be expected to 
be exposed.
---------------------------------------------------------------------------

    2.8.1.1.4  Those MPA's which are substantially impacted by 
several different and geographically disjoint local sources of fine 
particles should have separate core sites to monitor each 
influencing source region.
    2.8.2.1.5  Each spatial averaging zone in a required MPA shall 
have at least one core monitor; the SAZ for an optional MPA should 
have at least one core monitor; and there should be one core site 
for each SAZ with four or more SLAMS. Rural MPA's and areas with 
disperse towns and small cities may have a single core station per 
MPA but may have additional PM2.5 stations of other categories.
    2.8.2.1.6  The State shall also install at least one core SLAMS 
to monitor for regional background and at least one core SLAMS to 
monitor regional transport. These core monitoring stations may be 
population oriented and their requirement may be satisfied by a 
corresponding core monitoring in a representative area having 
similar air quality in another State.
    2.8.2.1.7  Within each monitoring planning area, one core 
monitor may be exempted by the Regional Administrator. This may be 
appropriate in areas where the highest concentration is expected to 
occur at the same location as the area of maximum or sensitive 
population impact, or areas with low concentrations (e.g. highest 
concentrations are less than 80 percent of the NAAQS). When only one 
population-oriented core monitor for PM2.5 may be included in a 
MPA/SAZ, however, a ``type b'' core site is strongly preferred to 
determine representative PM2.5 concentrations in areas of high 
population density.
    2.8.2.1.8  A subset of the core PM2.5 SLAMS shall be 
designated NAMS as discussed in section 3.7 of this appendix. The 
selection of core monitoring sites in relation to MPA's and SAZs is 
discussed further in section 2.8.3 of this appendix.
    2.8.2.2.  Other PM2.5 SLAMS locations
    In addition to the required core sites described in section 
2.8.2.1 of this appendix, the State shall also be required to 
establish a minimum number of additional SLAMS. The number of 
stations shall be based on the total population outside the 
monitoring planning areas which contain population-oriented core 
SLAMS. There shall be one such additional SLAMS for each 250,000 
people. This number of monitors are in addition to the core SLAMS 
required for monitoring planning areas. This may be satisfied, in 
part, by the regional background and regional transport core SLAMS 
if the latter sites are population-oriented. The minimum number of 
SLAMS may be developed anywhere in the State to satisfy the SLAMS 
monitoring objectives described in Section 1 of this appendix. Other 
SLAMS may also be established and are encouraged in a State 
PM2.5 network.
    2.8.2.3  Continuous fine particle monitoring at Core SLAMS
    At least one continuous fine particle analyzer (e.g., beta 
attenuation analyzer; tapered-element, oscillating microbalance 
(TEOM); transimissometer; nephelometer; or other acceptable 
continuous fine particle monitor) shall be located at a core 
monitoring PM2.5 site in each metropolitan area with a 
population greater than 1 million. The analyzer shall preferably 
sample the ambient air of the same spatial averaging zone as a 
category (b) core SLAMS. These analyzers shall be used to provide 
improved temporal resolution to better understand the processes and 
causes of elevated PM2.5 concentrations and to facilitate 
public reporting of PM2.5 air quality. The methodology and QA/
QC requirements will be provided in supplementary EPA guidance.
    2.8.2.4  Additional PM2.5 Analysis Requirements
    Air pollution control agencies shall archive PM2.5 filters 
from all SLAMS sites for a minimum of one year after collection. All 
PM2.5 filters from core NAMS sites shall be archived for a 
minimum of 5 years. These filters shall be made available for 
supplemental analyses at the request of EPA or to provide 
information to State and local agencies on the composition and 
trends for PM2.5. The filters shall be archived in accordance 
with EPA guidance.
    2.8.3  Selection of Monitoring locations within SAZs and MPA's
    2.8.3.1  Figure 2 of this appendix illustrates a hypothetical 
monitoring planning area and shows the location of monitors in 
relation to population and areas of poor air quality. Figure 3 of 
this appendix shows the same hypothetical MPA as Figure 2 of this 
appendix and illustrates potential spatial averaging zones and the 
location of core monitoring sites within them. Figure 4 of this 
appendix illustrates which sites within the SAZs of the same MPA may 
be used for comparison to the PM2.5 NAAQS.

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    2.8.3.2  In Figure 2 of this appendix, a hypothetical monitoring 
planning area is shown representing a typical Eastern US urban 
areas. The ellipses represent zones with relatively high population 
and poor air quality, respectively. Concentration isopleths are also 
depicted. The highest population density is indicated by the urban 
icons, while the area of worst air quality is presumed to be near 
the industrial symbols. Each monitoring planning area is required to 
have at least two core population-oriented monitors (with PAMS areas 
requiring three) and may have as many other SLAMS and SPMS as 
necessary. All SLAMS should generally be population-oriented, while 
the SPMs can focus more on other monitoring objectives, e.g. 
identifying source impacts and the area boundaries with maximum 
concentration. ``Ca'' denotes ``category a'' core SLAMS site 
(populated-oriented site in area of expected maximum concentration); 
shown within the populated area and closest to the area with highest 
concentration. `` Cb'' denotes a ``category b'' core SLAMS site 
(area of poor air quality with high population density or 
representative of maximum population impact); it is shown in the 
area of poor air quality, closest to highest population density. 
``S'' denotes other SLAMS sites (monitoring for any objective: max 
concentration, population exposure, source-oriented, background, or 
regional transport or in support of secondary NAAQS). Finally, `` 
p'' denotes a Special Purpose Monitor (a specialized monitor which 
may use a non-reference sampler).
    2.8.3.3  A Monitoring Planning Area would have one or more 
Spatial Averaging Zones (SAZ) for aggregation of data for comparison 
to the annual NAAQS. The planning area has large gradients of 
average air quality and, as shown in Figure 3 is assigned 3 SAZs: an 
industrial zone, a downtown central business district (CBD) and a 
residential area. (If there is not a large difference between 
downtown concentrations and other residential areas, a separate CBD 
zone would not be necessary). If a required Monitoring Planning Area 
has multiple SAZ's, then each SAZ must have at least one core 
location. Therefore, in this example with 3 SAZ's, the MPA must have 
at least one additional core site (i.e. one SLAMS in the downtown 
CBD must be a core site).

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    2.8.3.4  The Figure 4 of this appendix diagram shows the 
designation of monitoring sites according to the eligible NAAQS with 
which comparisons are permitted. Note that site type ``B'' can be 
core, SLAMS or SPMs. D's may be SLAMS or SPMs. Within the 
residential zone, all monitors shown represent areawide air quality 
and can be averaged for comparison to the annual PM-2.5 NAAQS 
and also be used for comparison to the daily PM-2.5 standard. 
In the downtown CBD, one site is a local ``hot spot,'' used for 
comparison to the daily NAAQS only. The other site is typical of the 
CBD and can by itself represent this zone for comparison to the 
annual NAAQS. In this example area, the State might need to further 
subdivide the CBD into additional sub-zones: if concentration 
gradients are large or are associated with large areas/populations 
(e.g. Madison Avenue NYC with diesel buses). Then one or more sites 
in each sub-zone would be averaged and be eligible for comparison to 
the annual NAAQS. In the industrial zone shown, three sites shown 
are averaged for comparison to the annual NAAQS and are also used 
individually for comparison to the daily NAAQS. One site is 
additionally used for comparison to the daily standard and the 
remaining two special study sites shown either do not satisfy Part 
58 requirements or are not in the Monitoring Plan and therefore are 
not eligible for comparison to either PM2.5 NAAQS. One of the 
sites identified as ``B'' was a SPM. Finally note that all SPM's 
would be subject to the 3-year moratorium against data comparison to 
the NAAQS.

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    2.8.3.5   Figure 5 of this appendix illustrates how potential 
SAZs and PM2.5 monitors might be located in a hypothetical MPA 
typical of a Western State. Figure 6 of this appendix shows how the 
MPA's, SAZs, and PM2.5 monitors might be distributed within a 
hypothetical State. Western States with more localized sources of PM 
and larger geographic area could require a different mix of SLAMS 
and SPM monitors and may need more spatial averaging areas. Figure 5 
of this appendix illustrates a monitoring planning area for a 
hypothetical western State in which ``B's'' and ``D's'' represent 
the sites which are eligible for comparison the both NAAQS or the 
daily NAAQS only. Triangles are other special study sites. Spatial 
averaging zones are shown by shaded areas. As the networks are 
deployed, the available monitors may not be sufficient to completely 
represent all geographic portions of the Monitoring Planning Area. 
Due to the distribution of pollution and population and because of 
the number and spatial representativeness of monitors, the MPA's and 
SAZ's may not cover the entire State. NAAQS are indicated by ``X.'' 
The appropriate monitors within an SAZ would be averaged for 
comparison to the annual NAAQS and examined individually for 
comparison to the daily NAAQS. Other monitors are only eligible for 
comparison to the daily NAAQS. Both within the MPA's and in the 
remainder of the State, some special study monitors might not 
satisfy applicable part 58 requirements or will not be included in 
the State Monitoring Plan and will not be eligible for comparison to 
the NAAQS. The latter may include SLAMS monitors designated to study 
regional transport or to support secondary NAAQS in unpopulated 
areas.

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    2.8.4   Substitute PM Monitoring Sites
    2.8.4.1  Appendix C (section 2.2) to part 58 describes 
conditions under which PMPM10 samplers may be used as 
substitutes for PM2.5 samplers and when such PM10 samplers must 
be replaced with PM2.5 samplers. Analogous rules are described 
for TSP samples which can be used as substitutes for PM10. This 
provision is intended to be used when PM concentrations are low and 
substitute samplers can be used to satisfy the minimum number of PM 
samplers needed for an adequate PM network. This may be most 
appropriate when sufficient resources to purchase new PM samplers 
may not exist and existing samplers can be temporarily used to serve 
a new PM network.
    2.4.4.2  Monitoring sites at which PM10 samplers are 
intended to be used as substitute PM2.5 samplers must be 
identified in the PM monitoring plan. In order for a PM10 
sampler to be used as a substitute for PM2.5, the existing 
PM10 samplers must meet the quality assurance requirements of 
appendix A of this part, the siting requirements of appendix E of 
this part, and are located in areas of suspected maximum 
concentrations as described in section 3 of this appendix, and if 
the PM10 levels are below the ambient PM2.5 standards, 
analogous language applies to substitute TSP samplers for PM10. 
Moreover, if existing TSP sites satisfy these criteria, the TSP 
samplers may continue to be used as substitutes for PM10 SLAMS 
samplers under the provisions of section 2.2 of Appendix C of this 
part.
    2.4.4.3  If data produced by substitute PM samplers exceed the 
concentration levels described in Appendix C of this part, then this 
sampler shall be converted to a PM10 or PM2.5 sampler, 
whichever is indicated. If the State does not believe that a 
PM10 or PM2.5 sampler should alternatively be sited in a 
different location, the State shall submit documentation to EPA as 
part of its annual PM report to justify this decision. If a PM site 
is not designated as a substitute site in the PM monitoring plan, 
then high concentrations at this site would not necessarily cause 
this site to become a PM10 site.
    2.4.4.4  Consistent with Sec. 58.1, combinations of SLAMS 
PM10 or PM2.5 monitors and other monitors may occupy the 
same structure without any mutual effect on the regulatory 
definition of the monitors.

    25. Section 3 is amended by revising the third and fifth paragraphs 
to read as follows:

3. Network Design for National Air Monitoring Stations (NAMS)

* * * * *
    Category (a): Stations located in area(s) of expected maximum 
concentrations (generally microscale for CO, microscale or middle 
scale for Pb, middle scale or neighborhood scale for population 
oriented particulate matter, urban or regional scale for Regional 
transport PM2.5, neighborhood scale for SO2, and NO2, 
and urban scale for O3.
* * * * *
    For each MSA where NAMS are required, both categories of 
monitoring stations must be established. In the case of SO2 if 
only one NAMS is needed, then category (a) must be used. In the case 
of PM2.5, category (b) is strongly. The analysis and 
interpretation of data from NAMS should consider the distinction 
between these types of stations as appropriate.
* * * * *
    26. Section 3.7 is revised and section 3.7.1 through 3.7.6.4 are 
added to read as follows:

    3.7  Particulate Matter Design Criteria for NAMS
    3.7.1  Table 4 indicates the approximate number of permanent 
stations required in MSA's 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 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.
    3.7.2  Through promulgation of the NAAQS for PM2.5, the 
number of PM10 SLAMS is expected to decrease, but requirements 
to maintain PM10 NAMS remain in effect. The PM10 NAMS are 
retained to provide trends data, to support national assessments and 
decisions, and in some cases to continue demonstration that a NAAQS 
for PM10 is maintained as a requirement under a State 
Implementation Plan.
    3.7.3  The PM2.5 NAMS shall be a subset of the core SLAMS 
network. The PM2.5 NAMS are planned as long-term monitoring 
stations concentrated in metropolitan areas. A target range of 200 
to 300 stations shall be designated nationwide. The largest 
metropolitan areas (those with a population greater than 
approximately one million) shall have at least two PM2.5 NAMS 
stations.
    3.7.4  The number of total PM2.5 NAMS per Region will be 
based on recommendations of the EPA Regional Offices, in concert 
with their State and local agencies, in accordance with the network 
design goals described in sections 3.7.5 and 3.7.6 of this Appendix. 
The selected stations should represent the range of conditions 
occurring in the Regions and will consider factors such as total 
number or type of sources, ambient concentrations of particulate 
matter, and regional transport.
    3.7.5  The approach is intended give State and local agencies 
maximum flexibility while apportioning a limited national network. 
By advancing a range of monitors per Region, EPA intends to balance 
the national network with respect to geographic area and population. 
Table 5 presents the target number of NAMS per Region to meet the 
national goal of 200 to 300 stations. These numbers consider a 
variety of factors such as Regional differences in metropolitan 
population, population density, land area, sources of particulate 
emissions, and the numbers of PM10 NAMS.
    3.7.6  Since emissions associated with the operation of motor 
vehicles contribute to urban area particulate matter levels, 
consideration of the impact of these sources must be included in the 
design of the NAMS network, particularly in MSA's greater than 
500,000 population. In certain urban areas particulate emissions 
from motor vehicle diesel exhaust currently is or is expected to be 
a significant source of particulate matter ambient levels. The 
actual number of NAMS and their locations must be determined by EPA 
Regional Offices and the State agencies, subject to the approval of 
the Administrator as required by Sec. 58.32. The Administrator's 
approval is necessary to insure that individual stations conform to 
the NAMS selection criteria and that the network as a whole is 
sufficient in terms of number and location for purposes of national 
analyses.

                             Table 4.--PM10 National Air Monitoring Station Criteria                            
                                    [Approximate Number of Stations per MSA]                                    
----------------------------------------------------------------------------------------------------------------
                                                                          High          Medium          Low     
                        Population category                          concentration  concentration  concentration
                                                                           (b)            (c)            (d)    
----------------------------------------------------------------------------------------------------------------
>1,000,000.........................................................      6-10               4-8          2-4    
500,000-1,000,000..................................................       4-8               2-4          1-2    
250,000-500,000....................................................       3-4               1-2          0-1    
100,000-250,000....................................................       1-2               0-1            0    
----------------------------------------------------------------------------------------------------------------

    3.7.6.1  Selection of urban areas and actual number of stations 
per area will be jointly determined by EPA and the State agency.
    3.7.6.2  High concentration areas are those for which: Ambient 
PM10 data show ambient

[[Page 65872]]

concentrations exceeding either PM10 NAAQS by 20 percent or 
more.
    3.7.6.3  Medium concentration areas are those for which: Ambient 
PM10 data show ambient concentrations exceeding either 80 
percent of the PM10 NAAQS.
    3.7.6.4  Low concentration areas are those for which: Ambient 
PM10 data show ambient concentrations less than 80 percent of 
the PM10 NAAQS.


           Table 5.--Goals for Number of PM2.5 NAMS by Region           
------------------------------------------------------------------------
                                                           Percent of   
            EPA region                Number of NAMS     national total 
-------------------------------------------\1\--------------------------
1.................................  15 to 20.........  6 to 8.          
2.................................  20 to 30.........  8 to 12.         
3.................................  20 to 25.........  8 to 10.         
4.................................  35 to 50.........  14 to 20.        
5.................................  35 to 50.........  14 to 20.        
6.................................  25 to 35.........  10 to 14.        
7.................................  10 to 15.........  4 to 6.          
8.................................  10 to 15.........  4 to 6.          
9.................................  25 to 40.........  10 to 16.        
10................................  10 to 15.........  4 to 6.          
                                   -------------------------------------
    Total.........................  205-295..........  100.             
------------------------------------------------------------------------
\1\ Each region will have one to three NAMS having the monitoring of    
  regional transport as a primary objective.                            

    27. Section 4.2 is amended by redesignating Figures 1 and 2 as 
Figures 7 and 8.
    28. Section 5 is revised to read as follows:

5. Summary

    Table 6 of this appendix shows by pollutant, all of the spatial 
scales that are applicable for SLAMS and the required spatial scales 
for NAMS. There may also be some situations, as discussed later in 
appendix E of this part, where additional scales may be allowed for 
NAMS purposes.


                   Table 6.--Summary of Spatial Scales for SLAMS and Required Scales for NAMS                   
----------------------------------------------------------------------------------------------------------------
                                                          Scales applicable for SLAMS                           
        Spatial scale        -----------------------------------------------------------------------------------
                                  SO2         CO          O3          NO2         Pb         PM10        PM2.5  
----------------------------------------------------------------------------------------------------------------
Micro.......................                                                        
Middle......................                                   
Neighborhood................                                   
Urban.......................                                          
Regional....................                                                 
                                                                                                                
                                                                                                                
(6)Scales required for NAMS                                                                                     
                                                                                                                
Micro.......................                                                     \1\  
Middle......................                                                               
Neighborhood................                                   
Urban.......................                                                            \2\  
Regional....................                                                                          \2\   
----------------------------------------------------------------------------------------------------------------
\1\ Only permitted if representative of many such micro-scale environments.                                     
\2\ Either urban or regional scale for regional transport sites.                                                

    28. Section 6 is amended by revising reference 18 to read as 
follows:

6. References

* * * * *
    18. Network Design and Siting Criteria for PM2.5 prepared 
for U.S. Environmental Protection Agency, Research Triangle Park, 
NC. In preparation.

    29. Appendix E is amended by revising the heading of section 8, 
adding a sentence to the last paragraph of section 8.1 to read as 
follows, and in section 8.3 removing the term PM10 and adding in 
its place ``PM.''

Appendix E--Probe and Open Path Siting Criteria for Ambient Air 
Quality Monitoring

* * * * *

8. Particulate Matter (PM10 and PM2.5)

    8.1  Vertical Placement
    * * * Although microscale stations are not the preferred spatial 
scale for PM2.5 sites, there are situations where microscale 
sites representative of several locations within an area where large 
segments of the population may live or work (e.g., mid-town 
Manhattan in New York City). In these cases, the sampler inlet for 
such microscale PM2.5 stations must also be 2-7 meters above 
ground level.

Appendix F--[Amended]

    30. Appendix F is amended by redesignating section 2.7.3 as section 
2.7.4 and adding a new section 2.7.3 to read as follows:

    2.7.3  Annual Summary Statistics. Annual arithmetic mean 
(g/m3) as specified in appendix K of 40 CFR part 50. 
All daily PM-fine values above the level of the 24-hour PM-fine 
NAAQS and dates of occurrence. Sampling schedule used such as once 
every 6 days, everyday, etc. Number of 24-hour average 
concentrations in ranges:

------------------------------------------------------------------------
                                                              Number of 
                           Range                                values  
------------------------------------------------------------------------
0 to 15 (g/m\3\)..................................             
16 to 30...................................................             
31 to 50...................................................             
51 to 70...................................................             
71 to 90...................................................             
91 to 110..................................................             
Greater than 110...........................................             
------------------------------------------------------------------------

[FR Doc. 96-31437 Filed 12-12-96; 8:45 am]
BILLING CODE 6560-50-P