128 of 128 Complete Record

  00637859
  Revised Requirements for Designation of Reference and Equivalent Methods for PM sub 
  2.5 and Ambient Air Quality Surveillance for Particulate Matter
                               Vol. 62,No. 138
                                   Part IV
                                 62 FR 38764
                           Friday, July 18, 1997

  AGENCY:  ENVIRONMENTAL PROTECTION AGENCY (EPA)
  DOC TYPE:  Rules and Regulations
  CFR:  40 CFR Parts 53 and 58
  NUMBER:  AD-FRL-5725-6; RIN 2060-AE66
  DATES:  EFFECTIVE DATE: This regulation is effective September 16, 1997.
  CONTACT:  FOR FURTHER INFORMATION CONTACT: For general information, contact Brenda 
    Millar (MD-14), Monitoring and Quality Assurance Group, Emissions Monitoring, and 
    Analysis Division, Environmental Protection Agency, Research Triangle Park, North 
    Carolina 27711, Telephone: (919) 541-5651, e-mail: millar.brenda@email.epa.gov. 
    For technical information, contact Neil Frank (MD-14), Monitoring and Quality 
    Assurance Group, Emissions, Monitoring, and Analysis Division, Environmental 
    Protection Agency, Research Triangle Park, North Carolina 27711, Telephone: (919) 
    541-5560.
  ADDRESS:  ADDRESSES: All comments received relative to this rule have been placed 
    in Docket A-96-51, located in the Air Docket (LE-131), Environmental Protection 
    Agency, 401 M St., SW., Washington, DC 20460. The docket may be inspected between 
    8 a.m. and 5:30 p.m., Monday through Friday, excluding legal holidays. A 
    reasonable fee may be charged for copying.
  ACTION:  ACTION: Final rule.
  SUMMARY:  SUMMARY: This final rule revises the 40 CFR part 58 ambient air quality 
    surveillance regulations to include provisions for PM sub 2.5 (particulate matter 
    with an aerodynamic diameter less than or equal to a nominal 2.5 micrometers), as 
    measured by a new reference method being published in 40 CFR part 50, Appendix L, 
    elsewhere in this issue of the Federal Register or by an equivalent method 
    designed in accordance with requirements being promulgated in 40 CFR part 53. In 
    addition, this rule also revises existing ambient air quality monitoring 
    requirements for PM sub 10 (particles with an aerodynamic diameter less than or 
    equal to 10 micrometers). These revisions address network design and siting, 
    quality assurance (QA) and quality control (QC), operating schedule, network 
    completion, system modifications, data reporting, and other monitoring subjects.
  WORD COUNT:  116,356
  TEXT: 
   SUPPLEMENTARY INFORMATION:
  
  Table of Contents
  
  I. Authority
  
  II. Introduction
  
      A. Revision to the Particulate Matter NAAQS
  
      B. Air Quality Monitoring Requirements
  
  III. Discussion of Regulatory Revisions and Major Comments on 40 CFR Part 53
  
      A. Designation of Reference and Equivalent Methods for PM sub 2.5
  
      B. Reference Method Designation Requirements
  
      C. Equivalent Method Designation Requirements
  
      D. Proposed Reference and Equivalent Method Requirements
  
      E. Changes to the Proposed Method Designation Requirements
  
  IV. Discussion of Regulatory Revisions and Major Comments on 40 CFR Part 58
  
      A. Overview of Part 58 Regulatory Requirements
  
      B. Section 58.1 - Definitions
  
      C. Section 58.13 - Operating schedule
  
      D. Section 58.14 - Special purpose monitors
  
      E. Section 58.15 - Designation of monitoring sites
  
      F. Section 58.20 - Air quality surveillance: plan content
  
      G. Section 58.23 - Monitoring network completion
  
      H. Section 58.25 - System modification
  
      I. Section 58.26 - Annual State monitoring report
  
      J. Section 58.30 - NAMS network establishment
  
      K. Section 58.31 - NAMS network description
  
      L. Section 58.34 - NAMS network completion
  
      M. Section 58.35 - NAMS data submittal
  
      N. Appendix A - Quality Assurance Requirements for State and Local Air 
  Monitoring Stations (SLAMS)
  
      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. Appendix F - Annual Summary Statistics
  
      S. Review of Network Design and Siting Requirements for PM
  
      T. Resources and Cost Estimates for New PM Networks
  
  V. Reference
  
  VI. Regulatory Assessment Requirements
  
      A. Regulatory Impact Analysis
  
      B. Paperwork Reduction Act
  
      C. Impact on Small Entities
  
      D. Unfunded Mandates Reform Act of 1995
  
  I. Authority
  
      Section 110, 301(a), 313, and 319 of the Clean Air Act (Act) as amended 42 
  U.S.C. 7410, 7601(a), 7613, 7619.
  
  II. Introduction
  
  A. Revision to the Particulate Matter NAAQS
  
      Elsewhere in this issue of the Federal Register, EPA announced revisions to the 
  national ambient air quality standards (NAAQS) for particulate matter (PM). In that 
  document EPA amends the current suite of PM standards by adding PM sub 2.5 
  standards and by revising the form of the current 24-hour PM sub 10 standard. 
  Specifically, EPA is adding two primary PM sub 2.5 standards set at 15  mu g/m sup 
  3, annual mean, and 65  mu g/m sup 3, 24-hour average. The annual PM sub 2.5 
  standard would be met when the 3-year average of the annual arithmetic mean PM sub 
  2.5 concentrations is less than or equal to 15  mu g/m sup 3 from single or 
  multiple community-oriented monitors in accordance with 40 CFR part 50, Appendix K 
  and requirements set forth in this final rule. The 24-hour PM sub 2.5 standard 
  would be met when the 3-year average of the 98th percentile of 24-hour PM sub 2.5 
  concentrations at each population-oriented monitor within an area is less than or 
  equal to 65  mu g/m sup 3.
  
      EPA also retained the current annual PM sub 10 standard at the level of 50  mu 
  g/m sup 3 which would be met when the 3-year average of the annual arithmetic PM 
  sub 10 concentrations at each monitor within an area is less than or equal to 50  
  mu g/m sup 3. Further, EPA retained the current 24-hour PM sub 10 standard at the 
  level of 150  mu g/m sup 3, but revised the form such that the standard would be 
  met when the 3-year average of the 99th percentile of the monitored concentrations 
  at the highest monitor in an area is less than or equal to 150  mu g/m sup 3.
  
      In the part 50 final rule published elsewhere in this issue of the Federal 
  Register, EPA is also revising the current secondary standards for PM by making 
  them identical to the suite of primary standards. The suite of PM sub 2.5 and PM 
  sub 10 standards, in conjunction with the establishment of a regional haze program 
  under section 169A of the Clean Air Act (the Act), are intended to protect against 
  PM-related welfare effects including soiling and materials damage and visibility 
  impairment.
  
      As discussed in the part 50 final rule for the PM NAAQS, the PM sub 2.5 
  standards are intended to protect against exposures to fine particulate pollution, 
  while the PM sub 10 standards are intended to protect against coarse fraction 
  particles as measured by PM sub 10.
  
      For PM sub 2.5, the annual standard is intended to protect against both long- 
  and short-term exposures to fine particle pollution. Under this approach, the PM 
  sub 2.5 24-hour standard would serve as a supplement to PM sub 2.5 annual standard 
  {pg 38765} to provide additional protection against days with high PM sub 2.5 
  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 PM sub 2.5 annual standard) should be 
  accomplished by comparing the annual mean from a community-oriented monitor that is 
  representative of average community-wide exposure, or averaging the annual 
  arithmetic means derived from multiple, community-oriented monitoring sites, EPA 
  took into account several factors. As discussed in the part 50 final rule, many of 
  the community-oriented 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. 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 PM sub 2.5 standard is 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 
  monitoring data reflecting average community wide exposure would better reflect 
  area-wide PM sub 2.5 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 concept of average community exposures is not appropriate 
  for PM sub 10 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 final rule, the 24-
  hour PM sub 2.5 standard is intended to supplement an annual PM sub 2.5 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 
  PM sub 2.5 standard will 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 PM sub 2.5 standard based on monitoring data 
  representative of community average air quality, established in conjunction with a 
  24-hour standard based on the population-oriented monitoring site with the highest 
  measured values, will provide the most appropriate target for reducing area-wide 
  population exposure to fine particle pollution and will be most consistent with the 
  underlying epidemiological data base.
  
  B. Air Quality Monitoring Requirements
  
      A new Federal Reference Method (FRM) for PM sub 2.5 is promulgated in a new 
  Appendix L to 40 CFR part 50. Section 319 of the Act requires that uniform criteria 
  be followed when measuring ambient air quality. To satisfy these requirements, EPA 
  established procedures on February 10, 1975, in 40 CFR part 53 for the 
  determination and designation of reference or equivalent monitoring methods (40 FR 
  7049). Accordingly, new provisions are added to 40 CFR part 53 so that each 
  reference method for PM sub 2.5, based on a particular sampler, will be formally 
  designed as such by EPA. Similarly, samplers demonstrated as equivalent to the FRM 
  can also be designated. Furthermore, section 110(a)(2)(C) of the Act requires 
  ambient air quality monitoring for purposes of the State Implementation Plans 
  (SIPs) 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.
  
  fn 1 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 PM measured as PM sub 10 on July 1, 
  1987 (52 FR 24740); provisions for PM sub 2.5 are published in this final rule.
  
  fn 1 EPA intends to develop and propose for public comment a revised Pollutant 
  Standards Index that will address PM sub 2.5 as well as PM sub 10, at a later date.
  
      On December 13, 1996, these rules were proposed in the Federal Register as 
  amendments to 40 CFR parts 53 and 58. The intent of the monitoring method 
  designations and air quality surveillance requirements being promulgated today are 
  to establish a revised particulate matter monitoring network that will produce air 
  quality data utilizing uniform criteria for the purpose of comparison to the 
  revised primary and secondary PM NAAQS and to facilitate implementation of a 
  forthcoming regional haze program. The effective date of today's monitoring 
  regulation is September 16, 1997.
  
  III. Discussion of Regulatory Revisions and Major Comments on 40 CFR Part 53
  
  A. Designation of Reference and Equivalent Methods for PM sub 2.5
  
      Provisions for EPA designation of reference and equivalent methods for PM sub 
  10 and gaseous criteria pollutants have been previously established and are set 
  forth in 40 CFR part 53. On December 13, 1996, EPA proposed to amend part 53 to add 
  new provisions to govern designation of reference and equivalent method for PM sub 
  2.5. The December 13th notice proposed new, detailed sampler testing and other 
  requirements that would apply to candidate reference and equivalent PM sub 2.5 
  methods and describes how EPA proposed to determine whether a candidate method 
  should be designated as either a reference or equivalent method. The notice further 
  solicited public comments on the proposed new provisions. Those provisions, 
  modified somewhat based on the public comments received, are being promulgated 
  today as amended part 53.
  
      As for the other criteria air pollutants, reference methods for PM sub 2.5 are 
  intended to provide for uniform, reproduceable measurements of PM sub 2.5 
  concentrations in ambient air to serve as a measurement standard for the primary 
  purpose of making comparisons to the NAAQS. Equivalent methods for PM sub 2.5 allow 
  for the consideration and introduction of new and innovative PM sub 2.5 measurement 
  technologies for this same purpose, provided such new technologies can be shown to 
  provide PM sub 2.5 measurements comparable to reference measurements under a 
  variety of typical monitoring conditions.
  
  B. Reference Method Designation Requirements
  
      The new reference method for PM sub 2.5, described in 40 CFR part 50, Appendix 
  L contains a combination of design and performance specifications to define the 
  reference method PM sub 2.5 sampler. The performance-based specifications for the 
  reference method sampler allow manufacturers to design and fabricate different 
  samplers that would meet all reference method requirements. Accordingly, multiple 
  PM sub 2.5 reference methods are expected to become available from several 
  manufacturers, as is the case for reference methods for PM sub 10 and most gaseous 
  criteria pollutants. Each reference method for PM sub 2.5, based on a particular 
  sampler, will be formally designated as such by EPA under the new provisions added 
  to 40 CFR part 53.  {pg 38766}
  
      The requirements for designation of PM sub 2.5 reference methods are set forth 
  in subparts A and E of 40 CFR part 53. These requirements include specific tests to 
  show conformance with all design and performance specifications, an operational 
  field precision test, a comprehensive operation/instruction manual, and 
  documentation of an adequate manufacturing and testing quality system. Subpart A, 
  which has been amended to add provisions for PM sub 2.5 methods, sets forth the 
  general requirements for both reference and equivalent methods and for the process 
  under which applications are submitted and reference and equivalent method are 
  designated. New subpart E, which is devoted exclusively to PM sub 2.5 methods, 
  describes the test procedures and related requirements for candidate reference 
  methods.
  
  C. Equivalent Method Designation Requirements
  
      The requirements for designation of equivalent methods for PM sub 2.5 are also 
  set forth in amended part 53. The general requirements are set forth in subpart A. 
  All candidate equivalent methods are subject to the field tests for operational 
  precision and comparability to reference method measurements, which are specified 
  in subpart C. Both subparts A and C have been amended to include the provisions for 
  PM sub 2.5 methods.
  
      To minimize the number and extent of performance tests to which candidate 
  equivalent methods must be subjected, three classes of equivalent methods are 
  defined.
  
      Class I equivalent methods are based on samplers that have relatively small 
  deviations from the specifications for reference method samplers. Therefore, in 
  addition to the tests and other requirements applicable reference method samplers, 
  candidate Class I equivalent samplers must be tested only to make sure that the 
  modifications do not significantly compromise sampler performance. The additional 
  test requirements for most Class I candidate equivalent methods are a test for 
  possible loss of PM sub 2.5 in any new or modified components in the sampler inlet 
  upstream of the sample filter, and the field testing for comparability to reference 
  method samplers. These additional tests are described in subparts E and C, 
  respectively.
  
      Class II equivalent methods include all other PM sub 2.5 methods that are based 
  on a 24-hour integrated filter sample that is subjected to subsequent moisture 
  equilibration and gravimetric mass analysis. A sampler associated with a Class II 
  equivalent method will generally have one or more substantial deviations from the 
  design or performance specifications of the reference method, such that it cannot 
  qualify as a Class I equivalent method. 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 is required for designation of Class II candidate equivalent 
  methods, with the specific tests required depending on the nature and extent of the 
  differences between the candidate sampler and the specifications for reference 
  method samplers. These tests may include a full wind tunnel evaluation, a wind 
  tunnel inlet aspiration test, a static fractionator test, a fractionator loading 
  test, a volatility test, and field testing against reference method samplers. The 
  tests and their specific applicability to various types of candidate Class II 
  equivalent method samplers are set forth in the new subpart F.
  
      Finally, Class III equivalent methods include any candidate PM sub 2.5 methods 
  that cannot qualify as either Class I or Class II. This class includes any filter-
  based integrated sampling method having other than a 24-hour PM sub 2.5 sample 
  collection interval followed by moisture equilibration and gravimetric mass. More 
  importantly, Class III also includes filter-based continuous or semi-continuous 
  methods, such as beta attenuation instruments, harmonic oscillating element 
  instruments, and other complete in situ monitor types. Non-filter-based methods 
  such as nephelometry or other optical instruments will also fall into the Class III 
  category.
  
      The testing requirements for designation of Class III candidate methods are the 
  most stringent, because quantitative comparability to the reference method will 
  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 
  must be individually selected or specifically designed or adapted for each such 
  type of method. Therefore, EPA has determined 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, the specific test 
  procedures and performance requirements applicable to each Class III candidate 
  method will be determined by EPA on a case-by-case basis upon request, in 
  connection with each proposed or anticipated application for a Class III equivalent 
  method determination.
  
  D. Proposed Reference and Equivalent Method Requirements
  
      The proposed changes to 40 CFR part 53 to provide for designation of reference 
  and equivalent methods for PM sub 2.5 consisted of revisions to subparts A and C, 
  and new subparts E and F. The proposed revisions to subpart A included new 
  definitions applicable to PM sub 2.5 methods and clarifications of existing 
  definitions, clarifications of the reference and equivalent method designation 
  requirements for all pollutants including the new classes of equivalent methods for 
  PM sub 2.5, and requirements for PM sub 2.5 samplers to be manufactured in an 
  International Organization for Standardization (ISO) 9001- registered facility (or 
  equivalent). Additional proposed changes included clarifications of the test data 
  and other information required to be submitted in applications for a reference or 
  equivalent method determination, clarification of requirements for product warranty 
  and content of operation or instruction manuals, an increased time limit for 
  processing applications; and provisions for providing EPA with a candidate test PM 
  sub 2.5 sampler or analyzer to evaluate in connection with an application for 
  reference or equivalent method determination.
  
      Revisions to subpart C included new procedures and specifications for comparing 
  candidate equivalent methods for PM sub 2.5 to reference method samplers. The 
  entirely new subpart E described the technical procedures for testing the physical 
  (design) and performance characteristics of reference methods and Class I 
  equivalent candidate methods for PM sub 2.5. The new subpart F described the 
  procedures for testing the performance characteristics of Class II equivalent 
  methods for PM sub 2.5.
  
  E. Changes to the Proposed Method Designation Requirements
  
      The tests of the design and performance characteristics of candidate samplers 
  for designating reference methods as well as equivalent methods are intimately 
  related to the specifications for reference methods in 40 CFR part 50, Appendix L. 
  Many of the concerns expressed by commenters regarding the reference method for PM 
  sub 2.5 in 40 CFR part 50, Appendix L also apply to some of the provisions of part 
  53. Other comments were more directly concerned with the provisions of 40 CFR part 
  53, and these comments are summarized in this unit. {pg 38767}
  
      Several commenters addressed the responsibilities of EPA and manufacturers in 
  the method designation process. Specific comments included the suggestions that: 
  (1) It would be more appropriate for EPA to conduct the necessary testing of a 
  candidate method before designating a reference method; (2) that EPA should clarify 
  how it will respond to possible poor sampler performance under extreme 
  environmental conditions encountered in some areas of the United States, since the 
  samplers are not required to meet such extreme conditions; (3) that EPA should 
  clarify that specifications for completing sampler modifications or retrofits to 
  work in nonstandard environments should be included as part of a sampler purchase 
  contract; and (4) that EPA should clarify that the required method specifications 
  must be met throughout the warranty period and that the applicant accepts 
  responsibility and liability for ensuring conformance or resolving nonconformities, 
  including all necessary components of the system, regardless of the original 
  manufacturer.
  
      The new provisions contained in the modified 40 CFR part 53 require the 
  applicant to submit information and documentation to demonstrate that the 
  applicant's candidate reference method sampler meets all design specifications set 
  forth in 40 CFR part 50, Appendix L. The provisions also require the applicant to 
  carry out specific tests to demonstrate that the candidate reference or equivalent 
  method meets all performance specifications. The nature of these tests and the 
  requirement that they be carried out by the applicant rather than by EPA is 
  consistent with the previously established requirements in 40 CFR part 53 for 
  designating reference or equivalent methods for other criteria pollutants. Section 
  53.9 clearly states that a sampler sold as part of a designated method must meet 
  the applicable performance specifications for at least 1 year after delivery. 
  Section 53.9 further requires that ISO 9001 registration of the manufacturing 
  facility be maintained and that a Product Manufacturing Checklist signed by a 
  certified ISO auditor be submitted annually to verify manufacturing quality 
  control.
  
      In response to concerns about the performance of the sampler under extreme 
  weather conditions, EPA has established sampler specifications that are intended to 
  cover reasonably normal environmental conditions at about 95 percent of expected 
  monitoring sites. The performance tests in subpart E address essentially all of 
  these operational requirements. Specification of the sampler performance for sites 
  with extreme environmental conditions would substantially raise the cost of the 
  sampler for users, most of whom do not require the extra capability. EPA strongly 
  recommends that users requiring operation of samplers under extreme environmental 
  conditions develop supplemental specifications for modified samplers to cover those 
  specific conditions. Sampler manufacturers have indicated a commitment to respond 
  to such special operational needs.
  
      Documentation is required to demonstrate that samplers to be sold as reference 
  or equivalent methods for PM sub 2.5 will be manufactured under an effective 
  quality control system. Although some commenters supported the general quality 
  assurance concepts contained in the proposed method, several questioned the 
  inclusion of the ISO 9001- registration requirement. EPA believes that the ISO 9001-
   registration requirement and related provisions are the most cost- effective way 
  to ensure that samplers are manufactured in a facility conforming to 
  internationally recognized quality system standards.
  
      Several comments questioned the proposed requirement that each PM sub 2.5 
  sampler model be subjected to a specific annual evaluation of performance and meet 
  certain operating performance specifications. In response to these comments, this 
  requirement has been deleted. However, EPA will review the performance of each PM 
  sub 2.5 sampler model on an annual basis, and if compelling evidence indicates a 
  significant bias or other operational problem, the EPA Administrator may make a 
  preliminary finding to cancel a reference or equivalent method designation in 
  accordance with the provisions of Sec. 53.11 in subpart A.
  
      Otherwise, the provisions of 40 CFR part 53 have been retained to conform with 
  the requirements described in 40 CFR part 50, Appendix L. The proposed revisions to 
  subparts A and C have been retained with no substantive changes. However, minor 
  technical and editorial changes have been made to subparts A and C to clarify or 
  simplify proposed provisions. Subpart E has undergone extensive revision and 
  reorganization. Although these changes do not affect the objectives and nature of 
  the tests, they are intended to make the test requirements easier to understand and 
  the tests easier to perform. The changes were based on EPA's own experience in 
  performing tests of prototype candidate samplers and on comments from prospective 
  sampler manufacturers. Subpart F has also been revised to some extent. The changes 
  to subpart F are not substantive in nature, but numerous technical and editorial 
  changes were made to clarify the test requirements and make the tests, particularly 
  the volatility test, more straightforward to carry out.
  
      All testing related to an application for a PM sub 2.5 reference or equivalent 
  method determination under 40 CFR part 53 must be carried out in accordance with 
  American National Standards Institute/American Society for Quality Control 
  (ANSI/ASQC) E4 standards. These requirements are necessary to ensure that all 
  samplers or analyzers sold as reference or equivalent methods are manufactured and 
  tested to the high standards required to achieve the needed data quality. These 
  procedures are in keeping with the developing international standards for 
  manufacturing and testing in this and other industries.
  
  IV. Discussion of Regulatory Revisions and Major Comments on Part 58
  
      The following discussion presents an overview of the final part 58 monitoring 
  regulation. This is followed by a detailed discussion of the basic concepts 
  outlined in the December 13, 1996 monitoring proposal and addresses those comments 
  received on the proposed part 58 regulations that EPA considered to be most 
  relevant to the changes and additions adopted in the final rule. Comments not 
  addressed in this preamble are found in a Summary and Response to Comment document 
  that has been placed in Docket A-96-51. Those parts of the proposed regulations 
  which were not commented on have not been changed. The items are discussed in the 
  order in which they appear in the regulation.
  
  A. Overview of Part 58 Regulatory Requirements
  
      The requirements set forth in this rule simultaneously preserve the underlying 
  intent of the revised NAAQS and respond positively to the very substantial and 
  reasoned comments received on the proposal. Specifically, the major monitoring 
  requirements and principles set forth by the revised part 58 regulation include:
  
      1. PM sub 2.5 network design. Community- oriented (core) monitors that 
  represent community-wide average exposure, form the basis of PM sub 2.5 network 
  design. This approach is consistent with the data bases used to develop the NAAQS. 
  While all population-oriented monitoring locations are eligible for comparison to 
  the 24-hour PM sub 2.5 NAAQS, only locations representative of neighborhood or 
  larger spatial scales {pg 38768} are eligible for comparison to the annual NAAQS. 
  Community monitoring zones with constrained criteria may be also used to define 
  monitors acceptable for spatial averaging for comparison to the annual NAAQS. 
  Monitoring for regional transport and regional background is required to assist 
  with implementation of the air quality management program. The combination of 
  emphasis on well- sited community-oriented monitors and the feasibility by the 
  States to select the preferred community monitoring approach reduces complexity 
  associated with network design and planning. The number of required core PM sub 2.5 
  State and Local Air Monitoring Stations (SLAMS), and other PM sub 2.5 SLAMS results 
  in a minimum national requirement of approximately 850 PM sub 2.5 sites (compared 
  to 629 proposed); the total PM sub 2.5 network is projected to approach 1,500 PM 
  sub 2.5 sites. Exceptions to the minimum number of required samplers may be 
  approved by the EPA Regional Administrator. As proposed, the mature network of 
  1,500 PM sub 2.5 sites would be in place within 3 years. The phase-in of the 
  required network has been reduced from 3 to 2 years.
  
      2. PM sub 10 monitoring networks. Requirements for PM sub 10 network design and 
  siting are unchanged. Reductions in PM sub 10 networks are encouraged in areas of 
  low concentrations where the PM sub 10 NAAQS are not expected to be violated.
  
      3. Sampling frequencies. The sampling frequencies stipulated in 40 CFR 58.13 
  for both PM sub 2.5 and PM sub 10, have been modified to reflect a one in 3-day 
  minimum requirement. Required every day sampling at certain core sites may be 
  reduced to one in 3-day sampling after at least 3 complete years of data collection 
  with a reference or equivalent method or when collocated with a correlated 
  acceptable continuous (CAC) fine particulate monitor; background and regional 
  transport may also sample once every third day. Exceptions to the minimum 
  requirement may be approved by the EPA Regional Administrator for seasonal or year- 
  round sampling.
  
      4. Chemical speciation. A modest chemical speciation network of 50 PM sub 2.5 
  sites that provides a first order characterization of the metals, ions, and carbon 
  constituents of PM sub 2.5 is a requirement of this rule. These sites will be part 
  of the National Air Monitoring Stations (NAMS) network and will provide national 
  consistency for trends purposes and serve as a model for other chemical speciation 
  efforts. This required network represents a small fraction of all the chemical 
  speciation work that EPA expects to support with Federal funds. Additional efforts 
  may be used to enhance the required network and tailor the collection and analysis 
  of speciated data to the needs of individual areas.
  
      5. Quality assurance. The QA program is collectively based on a variety of QA 
  tools resulting in a program which is more efficient, less costly, and relaxes the 
  burden on State and local agencies. The key program requirements include:
  
      a. Independent field audits with a PM sub 2.5 FRM are used to evaluate the bias 
  of PM sub 2.5 measurements. The number of PM sub 2.5 audited sites compared to the 
  proposal are reduced from all non-collocated sites to 25 percent of all SLAMS sites 
  (including NAMS) and the audit frequency per site is reduced from 6 to 4 visits per 
  year.
  
      b. Flow checks will also be used to evaluate bias of PM sub 2.5 and PM sub 10 
  measurements and are conducted on a quarterly basis as proposed.
  
      c. Collocation with PM sub 2.5 FRM and Federal Equivalent Methods (FEM) 
  samplers at SLAMS sites is used to judge precision. The number of collocated sites 
  per reporting organization is 25 percent of all PM sub 2.5 SLAMS sites (20 percent 
  were proposed) and approximately 20 percent of all PM sub 10 SLAMS sites (which is 
  current practice).
  
      d. Systems audits are used to evaluate an agency's QA system and will be 
  performed by EPA every 3 years as originally proposed.
  
      In an effort to assist the State and local agencies in achieving the data 
  quality objectives of the PM sub 2.5 monitoring program, an incentive program has 
  been established that is based on network performance and maturity that can reduce 
  these QA requirements.
  
      6. Moratorium on the use of special purpose monitor (SPM) data. The moratorium 
  on the use of PM sub 2.5 data ( Sec. 58.14) collected by SPMs, has been changed 
  from the first 3 calendar years following the effective date of this rule to the 
  first 2 complete calendar years of operation of a new SPM. If such monitors produce 
  valid data for more than 2 years, then all historical data for that site may be 
  used for regulatory purposes.
  
      7. Monitoring methodology. Appendix C has been revised to allow the use of 
  Interagency Monitoring of Protected Visual Environments (IMPROVE) samplers at 
  regional transport and regional background sites to satisfy the SLAMS requirements.
  
      8. PM monitoring network description. The State shall submit a PM monitoring 
  network description to the EPA Regional Administrator by July 1, 1998, which 
  describes the PM monitoring network, its intended community monitoring approach for 
  comparison to the annual PM sub 2.5 standard, use of non-population-oriented 
  special purpose PM sub 2.5 monitors or alternative samplers, and proposed 
  exceptions to EPA's requirements for minimum number of monitors or sampling 
  frequency. The description shall be available for pubic inspection and EPA shall 
  review and approve/disapprove the document within 60 days. A State air monitoring 
  report with proposed network revisions, if any, shall be submitted annually.
  
      EPA believes that the aforesaid revisions to the rule, as proposed, provide a 
  firm basis for the uniform implementation of a national particulate monitoring 
  network which is responsive to a revised NAAQS expressed as PM sub 2.5. The 
  following is a section-by-section discussion of comments received and any resulting 
  modifications to the proposal.
  
  B. Section 58.1 - Definitions
  
      EPA proposed to add several definitions applicable to PM monitoring. This 
  consisted of revising the definition of the term traceable and definitions of the 
  terms Consolidated Metropolitan Statistical Area (CMSA), core SLAMS, equivalent 
  methods, Metropolitan Statistical Area (MSA), monitoring planning area (MPA), 
  monitoring plan, PM sub 2.5, Primary Metropolitan Statistical Area (PMSA), 
  population-oriented, reference method, spatial averaging zone (SAZ), SPM fine 
  monitors, and Annual State Monitoring Report. In response to comments, EPA is 
  modifying the proposed approach and is introducing new terminology and definitions. 
  First, EPA is changing the definition of core SLAMS monitors to describe community-
  oriented monitors that are representative of neighborhood or larger spatial scales 
  and will be key monitoring entities in the new PM sub 2.5 SLAMS network. As 
  discussed later, a subset of these monitors will be required to sample everyday in 
  the most populated metropolitan areas with the stated emphasis on community-
  oriented monitoring. Although very important, the background and regional transport 
  monitors in the SLAMS network are no longer called core sites. Secondly, EPA is 
  replacing the definition of spatial averaging zone with a definition of community 
  monitoring zone (CMZ). This is consistent with the intent of the annual PM sub 2.5 
  standard, that is to be judged at monitoring stations that are representative of 
  community-wide air quality. EPA is also renaming the PM monitoring plan as the PM 
  monitoring network description. EPA's rationale for {pg 38769} these changes, 
  together with a more complete description of community monitoring zones, are 
  discussed in 40 CFR part 58, Appendix D.
  
      In addition, several commenters addressed the definition of population- 
  oriented monitoring, objecting to the narrowness of the definition with respect to 
  industrial areas, and noting that if people are present in an area, the site should 
  be considered population- oriented.
  
      EPA assessed these comments and concluded that the definition of population-
  oriented monitoring or sites proposed in Sec. 58.1 is essentially appropriate and 
  as such will provide monitoring agencies with the flexibility to design networks 
  that are consistent with the population-oriented approach described by the PM sub 
  2.5 standards. Therefore EPA is retaining this definition in the final rule with a 
  minor simplifying change as follows: population- oriented monitoring (or sites) 
  applies to residential areas, commercial areas, recreational areas, industrial 
  areas and other areas where a substantial number of people may spend a significant 
  fraction of their day. The definition of population-oriented monitoring will be 
  further deliniated in future EPA guidance. As proposed, the final rule states that 
  all population-oriented PM sub 2.5 monitoring locations shall be eligible for 
  comparison to both the 24-hour PM sub 10 and PM sub 2.5 standards. In order to make 
  these concepts clearer for the final rule, however, several changes to the proposed 
  language were made in the final rule regarding eligibility of monitoring sites for 
  comparisons to the PM sub 2.5 NAAQS. First, the new PM sub 2.5 network will place 
  emphasis on community-oriented monitoring for making comparisons to both the annual 
  and 24-hour PM sub 2.5 NAAQS. Secondly, as proposed, unique population-oriented 
  microscale and middle-scale monitoring sites shall only be used for comparisons to 
  the 24-hour NAAQS. Furthermore, violations detected at rural background and 
  regional transport sites are more appropriately addressed by the implementation 
  program which EPA is developing.
  
  C. Section 58.13 - Operating Schedule
  
      EPA proposed that core PM sub 2.5 SLAMS (including NAMS and core SLAMS 
  collocated at Photochemical Assessment Monitoring Stations (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 one in 6-day 
  sampling would be permitted. The proposal stated that 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). The proposed and final 
  rule state that special purpose monitors may sample on any sampling schedule. The 
  proposal also recognized that 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 FRMs or Class I equivalent 
  samplers (under the provisions of part 53) that will simplify the data collection 
  process. Finally, EPA proposed that alternative PM sub 2.5 operating schedules that 
  combine intermittent sampling with the use of acceptable continuous fine 
  particulate samplers are approvable at some core sites. This alternative was 
  intended to give the States additional flexibility in designing their PM sub 2.5 
  monitoring networks and to permit data from continuous instruments to be 
  telemetered. This would facilitate public reporting of fine particulate 
  concentrations, and allow air pollution alerts to be issued, and allow episodic 
  controls to be implemented (as currently done in woodburning areas for PM sub 10). 
  Furthermore, this alternative 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 of this rule. As proposed, applicability 
  does not apply to areas with population greater than 1 million during the first 2 
  years of required sampling.
  
      Many commenters supported daily PM sub 2.5 sampling, citing the need to target 
  sources, aid enforcement, and provide exposure measurements for future community 
  health studies. Additionally, commenters supported daily PM sub 2.5 sampling to 
  cover the most polluted and most populated areas and to capture all violations. 
  Other commenters supported daily sampling but suggested limiting it to key 
  locations or seasons (e.g., only the largest metropolitan areas or those areas with 
  the highest PM sub 2.5 concentrations, only during seasons when high values are 
  likely). Other commenters suggested allowing a reduction in sampling frequency to 
  one in 6 days under certain conditions; for example, at sites that have 
  demonstrated attainment, at sites with CAC analyzers, following the third year of 
  data collection, and during the portion of the year with low PM sub 2.5 
  concentrations at a site with a district seasonal pattern.
  
      In addition, a number of commenters suggested a delay of everyday sampling 
  until the Class I equivalent samplers are available. It was noted that over the 
  short- term, only designated manual samplers capable of collecting single 24-hour 
  samples, could be available. Consequently, to meet an everyday sampling schedule, 
  several samplers would need to be installed at each everyday sampling site to 
  satisfy the daily schedule, and cover weekend and holiday sampling periods.
  
      Based on its review of these comments, EPA is retaining its everyday sampling 
  schedule for certain community-oriented (core) SLAMS (i.e., two monitoring sites in 
  each MSA greater than 500,000 population and SLAMS collocated at PAMS for a total 
  of 313 nationwide). The remaining SLAMS including NAMS and other core SLAMS are 
  required to sample every third day.
  
      Because of concerns over the potential unavailability of Class I sequential 
  samplers, EPA is allowing a waiver of the everyday or every third day sampling 
  schedule, when appropriate, in those situations where such sampling is not needed. 
  This waiver would expire 1 calendar year from the time a sequential sampler has 
  been approved by EPA. When the waiver is granted for every day sampling, one in 3-
  day sampling would be required. As proposed, EPA encourages the use of a 
  supplemental CAC analyzer as a means of facilitating a reduction of the reference 
  or equivalent method everyday sampling schedule to once in 3 days. The CAC 
  monitoring option, however, will not be allowed in areas greater than 1 million 
  population that have high PM sub 2.5 concentrations during the first 2 years of 
  daily data collection. A minimum frequency of one in 6-day sampling is still 
  required during periods for which exemptions to everyday or every third day 
  sampling are allowed for PM sub 2.5 SLAMS.
  
      For PM sub 10, the EPA Administrator proposed that one in 6-day sampling should 
  be sufficient to support the proposed PM sub 10 NAAQS and a less dense monitoring 
  network would also be needed.
  
      A number of commenters supported the typical one in 6-day sampling frequency 
  for PM sub 10. On the other hand, a number of commenters opposed the proposed 
  reduction in PM sub 10 sampling frequency to one in 6 days, stating that one in 6-
  day sampling is inadequate to evaluate impacts on the 24-hour PM sub 10 {pg 38770} 
  standard, especially in areas with episodic events or localized hot spots, and that 
  extreme pollutant conditions could be missed.
  
      In response to the general concerns that sampling for PM sub 10 is not 
  sufficient and in accordance with the choice of the 99th percentile as the form of 
  the 24-hour PM sub 10 standards as discussed in 40 CFR part 50, EPA has changed the 
  minimum required sampling frequency from one sample every 6 days to one sample in 
  every 3 days.
  
      The specified minimum sampling frequency of one in 3 days for PM sub 2.5 and PM 
  sub 10 will provide for a more statistically stable representation of actual air 
  quality at each monitor as discussed in 40 CFR part 50. Further, increasing the 
  sampling frequency from one in 6- to one in 3-days will ensure that the 24-hour 
  NAAQS comparisons are not based on the highest measured values per year, and thus 
  will significantly reduce the chances of incorrectly classifying a "clean" area as 
  nonattainment, and at the same time provide enough information to confidently 
  classify "dirty" areas as nonattainment without requiring those areas to sample 
  every day.
  
      EPA believes that once in 6-day sampling is sufficient to estimate an annual 
  mean concentration for PM sub 2.5 or PM sub 10. Furthermore, every day or every 
  third day sampling is not generally needed during periods of the lowest ambient PM 
  concentrations. Therefore, EPA is allowing exemptions to the every day or the one 
  in 3-day sampling requirement to individual areas with the approval of the EPA 
  Regional Administrator, in accordance with forthcoming EPA guidance. In general, 
  exemptions to the minimum one in 3-day sampling frequency will be approvable when 
  existing information suggests that maximum 24-hour measurements are less than the 
  level of the standard. In these cases, a minimum of one in 6-day sampling will be 
  required to ensure that sufficient data are available to calculate an annual 
  average concentration. Areas adopting less frequent sampling would be advised of 
  the risks involved in such a choice; namely, that a single high value in 1 year 
  could end up causing the area to be declared in violation of the 24-hour NAAQS. The 
  guidance will also recommend that more frequent sampling be considered for those 
  areas that are relatively close to the level of the standard. For example, areas 
  whose PM sub 2.5 or PM sub 10 data indicate that they meet the annual PM NAAQS, but 
  have the potential to not meet the 24-hour PM NAAQS will be encouraged to sample 
  everyday for PM sub 2.5 or PM sub 10, as appropriate, during the high PM seasons in 
  order to better assess their status to the standards. While such an option may be 
  more costly for individual areas, the risk of inaccurately declaring an attainment 
  area to be nonattainment would be reduced.
  
  D. Section 58.14 - Special Purpose Monitors
  
      EPA proposed that special purpose monitoring (SPM) is needed in a new PM sub 
  2.5 monitoring program 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. It was 
  proposed, however, that data from SPMs would not be used for 
  attainment/nonattainment designations if the monitor is located in an unpopulated 
  area, if the monitoring method is not a reference or equivalent method or does not 
  meet the requirements of section 2.4 of 40 CFR part 58, Appendix C. Moreover, in 
  order to encourage the deployment of SPMs, EPA proposed 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.
  
      Numerous commenters opposed the proposed 3-year exclusion of SPM data as a 
  basis for NAAQS violations, noting that all measured violations from all monitors 
  should be used for nonattainment designations. Other commenters supported the 
  exclusion, suggesting that SPM data should always be considered exploratory in 
  nature and should remain exempt from inclusion in regulatory data bases.
  
      EPA has revisited its position on SPMs in light of these comments. In order to 
  encourage the deployment of SPMs, EPA has decided to continue to provide States 
  with the flexibility to exempt SPM data from regulatory use, but limit the period 
  of the moratorium to the first 2 complete calendar years of operation of a new SPM. 
  Given the currently limited amount of PM sub 2.5 data and the complexity of the PM 
  sub 2.5 air quality problem, the Agency feels that this approach still provides a 
  significant incentive for States to engage in additional monitoring and thereby 
  collect data that would supplement the data collected at SLAMS sites. This can be 
  very helpful for establishing an optimum network design, for a better understanding 
  of the impacts of specific emission sources, and for other planning purposes. If a 
  monitoring site satisfies all applicable part 58 requirements including use of 
  reference or equivalent methods, meeting siting criteria, and other requirements as 
  explained in Sec. 58.14 and it continues to collect data beyond the first 2 
  complete calendar years of its operation, the data from such SPM sites would then 
  be generally eligible for comparisons to the NAAQS. One exception is when a 
  monitoring agency intends to evaluate a special situation which is not 
  representative of population-oriented monitoring. In this case, the data from the 
  special purpose monitor would not be used for comparison to the PM sub 2.5 
  standards. A second exception is when the agency intends to evaluate a unique 
  impact area that represents a small spatial scale (micro or middle). In this case, 
  the site would only be eligible for comparison to the 24-hour NAAQS. Although SPM 
  data will be exempt from regulatory use during the 2- year moratorium, EPA 
  emphasizes that SPM data should nevertheless be considered in the State's PM 
  monitoring network description and in the design of its overall SLAMS network. 
  Moreover, SPM sites reporting values greater than the level of a NAAQS should be 
  considered during the annual network review in accordance with Sec. 58.25, and 
  summary data from SPM sites must be included in the annual State Air Monitoring 
  report described in Sec. 58.26.
  
  E. Section 58.15 - Designation of Monitoring Sites
  
      The proposed monitoring regulations defined categories of sites that would be 
  eligible for comparisons to the annual or 24-hour NAAQS. This included certain 
  sites that could be used for comparison to both standards (B sites), to only the 
  daily standard (D sites) and certain special purpose monitors (O sites) that 
  potentially would not be used for comparison to any standard. Due to significant 
  concern regarding the complexity of implementing those concepts to handle a small 
  number of unique monitoring situations, the final rule has eliminated the coding of 
  sites as type B, D, and O sites. Therefore, Sec. 58.15 has been deleted in its 
  entirety. The principal reasons also include the emphasis on community-oriented 
  monitors, the new terminology and modified approach associated with CMZs, and more 
  precise descriptions of SLAMS and SPMs. The final rule provides a more streamlined 
  and simplified monitoring approach that retains the basic community average air 
  quality exposure tenets of the PM sub 2.5 annual NAAQS and, as proposed, {pg 38771} 
  recognizes that population-oriented hot spot monitoring may be more reflective of 
  situations applicable to the purposes of the 24-hour PM sub 2.5 standard.
  
      The changes to community monitoring and site categorization are well 
  integrated. EPA agrees with public comment that the proposed spatial averaging 
  approach may not have been properly communicated by suggesting that it allowed 
  averaging of monitors across widely disparate areas not reflective of average 
  community-oriented exposure and a homogeneous emission source mix. EPA believes 
  that by clarifying the criteria that determine which monitors can be averaged 
  together (i.e., monitors in areas affected by similar emission sources), along with 
  emphasizing that well sited community-oriented monitors should be used, 
  environmental equity concerns and related issues are effectively addressed. First, 
  a single SLAMS or SPM that adequately represents a local area can reflect its own 
  community monitoring area. If its annual average concentrations are more than 20 
  percent higher than the surrounding average PM sub 2.5 air quality, it would not be 
  eligible to be averaged in with the surrounding sites of the larger geographic 
  domain. In addition, unique population-oriented hot spot impact sites are not 
  eligible for comparison to the annual PM sub 2.5 NAAQS and are only eligible for 
  comparison to the 24-hour NAAQS. Additional details about CMZs are provided later.
  
  F. Section 58.20 - Air Quality Surveillance: Plan Content
  
      Although no comments were received on proposed changes to this section, the 
  title was inadvertently stated as Plan Control; this title has been changed to Plan 
  Content. In addition, the first sentence of paragraph (d) has been changed by 
  deleting the words "section 2.8 of" and the words "as well as the minimum 
  requirements for networks of SLAMS stations for PM sub 2.5 described in section 
  2.8.2 of 40 CFR part 58, Appendix D." Since Sec. 58.20 requires an annual review of 
  the air quality surveillance system for all SLAMS, these changes were instituted 
  for clarity. The reference to PM sub 2.5 in the third sentence of Sec. 58.20 was 
  retained to ensure that the review includes the unique requirements of the PM sub 
  2.5 monitoring network.
  
      The proposal indicated that a detailed Particulate Matter Monitoring Plan (see 
  Sec. 58.1, as proposed) must be prepared by the affected air pollution control 
  agency and submitted to EPA for approval. This plan was designed to comprehensively 
  describe the Agency's PM sub 2.5 and PM sub 10 air quality surveillance networks. 
  Comments received noted that the term PM monitoring plan could be confused with the 
  network description required by Sec. 58.20. Accordingly, EPA has replaced 
  references to the "PM Monitoring Plan or monitoring plan" in this final rule with 
  references to the "particulate matter monitoring network description or PM 
  monitoring network description." The Agency notes, however, that the rule published 
  today requires a more expanded and comprehensive network description for PM than 
  has previously been required for other networks. Therefore, a new paragraph (f) has 
  been added to Sec. 58.20 to delineate the requirements for PM monitoring network 
  descriptions. According to Sec. 58.20(e), as amended, this network description must 
  be submitted to the EPA Regional Administrator for approval.
  
      To ensure opportunities for public review and inspection of the monitoring 
  network, States must maintain information and records on such items as the station 
  location, monitoring objectives, spatial scale of representativeness, optional 
  CMZs, and schedule for completion of the network. Such information and records are 
  included in a State's PM monitoring network description. The PM monitoring network 
  description prepared by States and submitted to EPA for approval should be viewed 
  as a long-term network of SLAMS and NAMS sites that meet the variety of monitoring 
  objectives specified in 40 CFR part 58, Appendix D of these regulations. These 
  objectives include determining compliance with air quality standards, developing 
  appropriate control strategies as required, and preparing short- and long-term air 
  quality trends. However, modifications to the network can be made without a formal 
  SIP revision thus encouraging States to make any needed yearly (or alternate 
  schedule as determined by the EPA Regional Administrator) changes to the SLAMS 
  network to make it more responsive to data needs and resource constraints. In order 
  to avoid making major modifications to the PM monitoring network description during 
  the annual review, the detailed network, including monitoring planning areas and 
  CMZs, should be carefully planned and designed to provide a stable base of air 
  quality data. Since no formal SIP revision (that entails Federal Register proposal 
  and public comment) is required for the PM monitoring network description 
  revisions, EPA encourages public involvement in the review of a State's PM 
  monitoring network description particularly when the spatial averaging monitoring 
  approach is selected for comparisons to the annual standard.
  
  G. Section 58.23 - Monitoring Network Completion
  
      EPA proposed that the PM networks would be expected to be completed within 3 
  years of the effective date of promulgation. While new PM sub 2.5 networks are 
  developed, reductions in existing PM sub 10 networks would be considered. The 
  proposal stated that during the first year, a minimum of one monitoring planning 
  area per State would be required to have core PM sub 2.5 SLAMS. This area would be 
  selected by the State according to the likelihood of observing high PM sub 2.5 
  concentrations and according to the size of the affected population. In addition, 
  one PM sub 2.5 site was proposed to be collocated at one PAMS site in each of the 
  PAMS areas. During the second year, all other core population-oriented PM sub 2.5 
  SLAMS, and all core background and transport sites, were proposed to be fully 
  operational. During the third year, any additional required PM sub 2.5 (non-core) 
  SLAMS was proposed to be fully deployed and all NAMS sites would be selected from 
  core SLAMS and proposed to EPA for approval.
  
      Several commenters discussed the proposed phase-in schedule. One commenter 
  supported an accelerated phase-in schedule, while other commenters supported a 
  longer phase- in period. Several State commenters expressed reservations about 
  their ability to meet the proposed phase-in schedule, due to limited resources and 
  the unavailability of monitoring equipment. One commenter felt that the phase-in 
  should require one core monitor in each of a few geographically diverse areas per 
  State, as this would provide more valuable information than only one per MPA.
  
      As noted in the comments on 40 CFR part 58, Appendix D, a large number of 
  commenters cited the immediate need for an expansive PM sub 2.5 monitoring network 
  to provide adequate monitoring data to satisfy the monitoring objectives of the 
  SLAMS network, in particular, to provide 3 years of PM sub 2.5 data in order to 
  make comparisons with the NAAQS. As noted in the discussion below on resources and 
  costs, the Agency's grant allocations for fiscal years 1997-1998 include 
  significant resources to accelerate the implementation schedule and increase the 
  number of monitoring sites included in today's final rule. In view of these 
  actions, the Agency is accelerating the SLAMS monitoring {pg 38772} network 
  completion schedule to require at least one core monitor in each MSA greater than 
  500,000 population plus one PM sub 2.5 site to be collocated with a PAMS site in 
  each PAMS area and at least 2 additional SLAMS per State to be in operation by 
  1998; to require all other required SLAMS including required regional transport and 
  regional background sites to be in operation by 1999; and to encourage all 
  additional sites (to complete the network) to be in operation by 2000. In addition, 
  the States should have at least one core SLAMS to be deployed in all areas expected 
  to have the potential for high PM sub 2.5 concentrations, in accordance with EPA 
  guidance, to be in operation by 1998 which will be supported with funding from 
  EPA's section 105 grant program.
  
  H. Section 58.25 - System Modification
  
      The preamble to the proposal noted that although no changes to the regulatory 
  language were proposed for this section, the annual monitoring system modifications 
  review must include changes to PM sub 2.5 site designations (e.g., NAAQS comparison 
  sites), and the number or boundaries of monitoring planning areas and/or spatial 
  averaging zones, now referred to as community monitoring zones. This information is 
  included for explanatory purposes only and does not necessitate changes to the 
  regulatory language.
  
  I. Section 58.26 - Annual State Monitoring Report
  
      Under the current regulations, States are required to submit an annual SLAMS 
  data summary report. EPA proposed that this report shall be expanded to: (1) 
  Describe the proposed changes to the State's PM Monitoring Network Description, as 
  defined in Sec. 58.20; (2) include a new brief narrative report to describe the 
  findings of the annual SLAMS network review, reflecting within the year and 
  proposed changes to the State air quality surveillance system; and (3) provide 
  information on PM SPMs and other PM sites noted in the PM monitoring network 
  description 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 for EPA to ensure that a proper mix of 
  permanent and temporary monitoring locations are used and that populated areas 
  throughout the Nation are monitored, and to provide needed flexibility in the State 
  monitoring program.
  
      In addition, the proposed changes to the PM monitoring network description 
  included changes to existing PM networks. The proposed changes to existing PM 
  networks included modifications to the number, size, or boundaries of MPAs or 
  SAZ's, number and location of PM SLAMS; number or location of core PM sub 2.5 
  SLAMS; alternative sampling frequencies proposed for PM sub 2.5 SLAMS (including 
  core PM sub 2.5 SLAMS and PM sub 2.5 NAMS); core PM sub 2.5 SLAMS to be designated 
  PM sub 2.5 NAMS; and PM SLAMS to be designated PM NAMS. SPM's with measured values 
  greater than the level of the NAAQS would become part of the SLAMS network. The 
  proposed changes would be developed in close consultation with the appropriate EPA 
  Regional Office and submitted to the appropriate Regional Office for approval. The 
  portion of the document pertaining to NAMS would be submitted to the EPA 
  Administrator (through the appropriate Regional Office).
  
      Finally, as a continuation of current regulations, the States would be required 
  to submit the annual SLAMS summary report and to certify to the EPA Administrator 
  that the SLAMS data submitted are accurate and in conformance with applicable part 
  58 requirements. Under the proposed revisions, States would also be required to 
  submit annual summaries of SPM data to the EPA Regional Administrator for sites 
  included in their PM monitoring network description and to certify that such data 
  are similarly accurate and likewise in conformance with applicable part 58 
  requirements or other requirements approved by the EPA Regional Administrator, if 
  these data are intended to be used for SIP purposes. All of the proposed changes 
  described above did not receive substantive comment and were retained in the final 
  rule.
  
      During the first 3 years following promulgation, the proposal stated that the 
  State's PM monitoring description (changed to PM monitoring network description) 
  and any modifications of it would 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 EPA Regional Administrator, with review and approval/disapproval by 
  the EPA Regional Administrator was proposed to occur within 45 days. After the 
  initial 3-year period or once an SAZ (now called CMZ) has been determined to be 
  violating any PM sub 2.5 NAAQS, then changes to a MPA would require public review 
  and notification to ensure that the appropriate monitoring locations and site types 
  are included.
  
      Several commenters addressed the requirements for the Annual State Monitoring 
  Report. Some commenters felt that the 45-day review was too restrictive and should 
  be extended to 60 days. Other commenters felt that the annual review requirement 
  was reasonable in the short-term, but should be reconsidered after 3 years.
  
      In response to these comments, the Agency is extending the Regional review 
  period to 60 days. After the first 3 years, the required annual review can be 
  reconsidered and its schedule revised as determined by the EPA Regional 
  Administrator. As discussed earlier in this preamble, EPA will entertain 
  suggestions for modifications to the published monitoring network requirements. 
  States can request exemptions from specific required elements of the network design 
  (e.g., required number of core SLAMS sites, other SLAMS sites, sampling frequency, 
  etc.) through the Annual Monitoring Report.
  
  J. Section 58.30 - NAMS Network Establishment
  
      The preamble to the proposal called for States to submit a NAMS network 
  description (which is to be derived from the core PM sub 2.5 SLAMS) of each State's 
  SLAMS network to the EPA Administrator (through the appropriate EPA Regional 
  Office) within 6 months of the effective date of the final rule. At the same time, 
  a State's NAMS PM sub 10 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 EPA Administrator (through the appropriate EPA Regional Office). 
  The proposed Sec. 58.34 stated that the NAMS Network completion shall be by 3 years 
  after the effective date of the final rule. This has not been changed in this final 
  rule. However, the proposed revisions to this section inadvertently called for the 
  PM sub 2.5 network description to be submitted 3 years after the effective date of 
  promulgation. The final rule has been changed to read July 1, 1998.
  
  K. Section 58.31 - NAMS Network Description
  
      The term spatial averaging zone was used in the proposed revisions to this 
  section. In the final rule, this term has been replaced by the term community 
  monitoring zone (CMZ). {pg 38773}
  
  L. Section 58.34 - NAMS Network Completion
  
      The preamble to the proposal called for changes to the NAMS PM sub 10 network 
  to be completed by 1 year after the effective date of the final rule and to the 
  NAMS PM sub 2.5 network to be completed by 3 years after the effective date of the 
  final rule. The proposed rule incorrectly stated 6 months instead of 1 year for the 
  PM sub 10 network to be completed. The final rule has been changed to read 1 year 
  after the effective date of these regulations for PM sub 10 and 3 years after the 
  effective date of these regulations for PM sub 2.5.
  
  M. Section 58.35 - NAMS Data Submittal
  
      The proposed revision to this section added PM sub 2.5 as an additional 
  indicator of PM to the list of pollutants that must submit air quality data and 
  associated information to the EPA Administrator as specified in the AIRS Users 
  Guide. This section is promulgated as proposed.
  
  N. Appendix A - Quality Assurance Requirements for SLAMS
  
      1. Summary of proposal. The proposal addressed the fact that enhanced QA and QC 
  procedures were required in the areas of sampler operation, filter handling, data 
  quality assessment, and other operator-related aspects of the PM sub 2.5 
  measurement process. These enhanced QA/QC procedures were necessary for meeting the 
  data quality objectives for ambient PM sub 2.5 monitoring.
  
      Most operational QC aspects were specified in 40 CFR part 58, Appendix A in 
  general terms. However, for PM sub 2.5, explicit, more stringent, requirements were 
  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. Details concerning these operator-related 
  procedures were proposed to be published as a new section 2.12 of EPA's Quality 
  Assurance Handbook for Air Pollution Measurement Systems, Volume II to assist 
  monitoring personnel in maintaining high standards of data quality.
  
      Procedures were proposed for assessing the resulting quality of the monitoring 
  data in 40 CFR part 58, Appendix A. Perhaps the most significant new data quality 
  assessment requirement proposed for PM sub 2.5 monitoring was the requirement that 
  each PM sub 2.5 SLAMS monitor was to be audited at least six times per year. This 
  was the first time a requirement had been proposed to assess the relative accuracy 
  of the mass concentration measured by a PM SLAMS monitor. Each of these six audits 
  would have been performed by the monitoring agency and would have consisted of 
  concurrent operation of a collocated reference method audit sampler along with the 
  PM sub 2.5 SLAMS monitor. The data from these collocated audits were proposed to 
  have been used by EPA to assess the performance of the PM sub 2.5 SLAMS monitor and 
  to identify reporting organizations or individual sites that had abnormal bias or 
  inadequate precision for the year.
  
      Other data assessment requirements proposed for PM sub 2.5 monitoring networks 
  were patterned after the current requirements for PM sub 10 networks and were 
  intended to supplement the audit procedure. The proposal required PM sub 2.5 
  network monitors to be subject to precision and accuracy assessments for both 
  manual and automated methods, using procedures similar or identical to the current 
  procedures required for PM sub 10 monitoring networks. Results of the field tests 
  performed by the monitoring agencies (including the field tests) would have been 
  sent to EPA. EPA then would have carried out the specified calculations which would 
  have become part of the annual assessment of the quality of the monitoring data.
  
      Although the proposed QA requirements for PM sub 2.5 would have resulted in an 
  increase in quality assessment requirement for PM monitoring, the additional QA/QC 
  checks would have incurred more cost to the monitoring agency. Some of the proposed 
  new QA/QC assessment requirements would have somewhat overlapped the information 
  provided by other checks, such as the periodic flow rate checks and the use of 
  collocated samplers in monitoring networks.
  
      A revision to 40 CFR part 58, Appendix A, was also proposed to provide for 
  technical system audits to be performed by EPA at least every 3 years rather than 
  every year. This change to a less frequent system audit schedule recognized the 
  fact that for many well established agencies, an extensive system audit and 
  rigorous inspection may not have been necessary every year. The determination of 
  the extent and frequency of system audits at an even lower frequency than the 
  proposed 3-year interval was being left up to the discretion of the appropriate EPA 
  Regional Office, based on an evaluation of the Agency's data quality measures. This 
  change would have afforded both EPA and the air monitoring agencies flexibility to 
  manage their air monitoring resources to better address the most critical data 
  quality issues.
  
      2. The PM sub 2.5 QA system. Based upon public comments, the Agency has 
  reviewed 40 CFR part 58, Appendix A and re- evaluated several aspects of the QA and 
  QC quality control system used to assess the particulate monitoring data. The 
  requirements associated with the PM sub 10 QA system remained unchanged by these 
  modifications. Specifically for PM sub 2.5, the major modifications include 
  focusing 80 percent of the QA resources to sites with concentrations of greater 
  than or equal to 90 percent of the annual PM sub 2.5 NAAQS (or 24-hour NAAQS if 
  that is affecting the area), increasing the amount of collocated monitors to 25 
  percent of the total number of SLAMS monitors within a reporting organization, and 
  changing the FRM audit procedures to an independent assessment of the bias of the 
  PM sub 2.5 monitoring network. The FRM audits were reduced in number to 25 percent 
  of the SLAMS monitors at a frequency of 4 times per year. All modifications are 
  discussed in detail in the following paragraphs.
  
      In response to comments that the proposed QA requirements were inadequate, and 
  in order to clarify the intent of the quality system, EPA is incorporating the 
  concept and definition of a quality system into section 2, Quality System 
  Requirements. EPA defines QA as an integrated system of management activities 
  involving planning, implementation, assessment, reporting, and quality improvement 
  to ensure that a process, item, or service is of the type and quality needed and 
  expected by the customer. QC is defined as the overall system of technical 
  activities that measures the attributes and performance of a process, item, or 
  service against defined standards to verify that they meet the stated requirements 
  established by the customer. A quality system is defined as a structured and 
  documented management system describing the policies, objectives, principles, 
  organizational authority, responsibilities, accountability, and implementation plan 
  of an organization for ensuring quality in its work processes, products (items), 
  and services. The quality system provides the framework for planning, implementing, 
  and assessing work performed by the organization and for carrying out required QA 
  and QC.
  
      The Agency used the data quality objective (DQO) process to specifically 
  develop the QA system for the new PM sub 2.5 program. The DQO process is a 
  systematic strategic planning tool based {pg 38774} on the scientific method that 
  identifies and defines the type, quality, and quantity of data needed to satisfy a 
  specific use. Meeting the new data quality objectives for ambient PM sub 2.5 
  monitoring requires a combination of QA and QC procedures to evaluate and control 
  data measurement uncertainty. For this reason, EPA has developed a quality system 
  specifically for PM sub 2.5 which incorporates procedures to quantify total 
  measurement uncertainty, as it relates to total precision and total bias, within 
  the PM sub 2.5 monitoring network. In order to clarify the tools used in the QA 
  system, the Agency has included definitions in 40 CFR part 58, Appendix A. Total 
  bias is defined as the systematic or persistent distortion of a measurement process 
  which causes errors in one direction (i.e., the expected sample measurement is 
  different from the sample's true value). Total precision is defined as a measure of 
  mutual agreement among individual measurements of the same property, usually under 
  prescribed similar conditions, expressed generally in terms of the standard 
  deviation. Accuracy is defined as the degree of agreement between an observed value 
  and an accepted reference value, accuracy includes a combination of random error 
  (precision) and systematic error (bias) components which are due to sampling and 
  analytical operations. The Agency will use various QA tools to quantify this 
  measurement uncertainty; this includes collocation of monitors at various PM sub 
  2.5 sites, use of operational flow checks, and implementation of an independent FRM 
  audit.
  
      The measurement system represents the entire data collection activity. This 
  activity includes the initial equilibration, weighing, and transportation of the 
  filters to the sampler; calibration, maintenance, and proper operation of the 
  instrument; handling/placement of the filters; proper operation of the instrument 
  (sample collection); removal/handling/transportation of the filter from the sampler 
  to the laboratory; weighing, storage, and archival of the sampled filter; and 
  finally, data analysis and reporting. Additional or supplemental detailed quality 
  assurance procedures and guidance for all operator-related aspects of the PM sub 
  2.5 monitoring process will be published as a new section 2.12 of EPA's Quality 
  Assurance Handbook for Air Pollution Measurement Systems, Volume II, Ambient Air 
  Specific Methods to assist monitoring personnel in maintaining high standards of 
  data quality.
  
      To clarify the requirements and guidance concerning the SLAMS ambient air 
  network, the Agency has developed Quality Assurance Division (QAD) requirements 
  documents, which are referenced in section 2.2. For simplification, the Agency has 
  removed the list of pertinent operational procedures from this section and has 
  replaced the list with the updated reference. In response to comments about 
  potential difficulties in following the requirements in ANSI E-4, EPA has instead 
  required quality assurance and control programs to follow the requirements for 
  quality assurance project plans contained in EPA requirements for quality assurance 
  project plans for environmental data operations, EPA QA/R- 5 an EPA QAD document.
  
      EPA received many comments on the proposed bimonthly audits for each PM sub 2.5 
  site as proposed in section 6.0 of Appendix A. Commenters expressed concerns about 
  the excessive burden the requirement would put on State and local air pollution 
  control agencies, the length of time involved with the process, and the quality 
  control, reliability, and logistical aspects of a portable audit device.
  
      Based upon these comments, the Agency re- assessed its position concerning the 
  number of sites and the frequency of audits that the State and local agencies 
  perform. The Agency feels that independent FRM audits are essential to reaching the 
  goal of the data quality objectives for PM sub 2.5 because these audits evaluate 
  the total bias for each designated PM sub 2.5 Federal Reference and Equivalent 
  monitoring method within the monitoring network. Therefore, the Agency has modified 
  the proposed audit program to make it independent and also to reduce the burden on 
  State and local agencies. Section 6.0 as proposed has been deleted, with remaining 
  data quality assessment requirements for PM sub 2.5 included in section 3.5 of 40 
  CFR part 58, Appendix A. The resulting data will be assessed at three distinct 
  levels--single monitor level, reporting organization level, and at a national 
  level. Details of the assessment process will be published in EPA's Quality 
  Assurance Handbook for Air Pollution Measurement Systems, Volume II, Ambient Air 
  Specific Methods.
  
      Commenters endorsed the reduction in the frequency of systems audits from every 
  year to every 3 years as proposed in section 2.5. Therefore, the requirement for a 
  3-year schedule for system audits remains unchanged.
  
      3. Evaluation of measurement uncertainty. EPA received several comments on the 
  procedures used to address the quality assurance of the data as proposed in section 
  3 of the Appendix. Commenters were concerned about the limited resources available 
  to properly comply with all aspects of the proposed quality system. In the initial 
  deployment of the SLAMS PM sub 2.5 network, special QA emphasis should be placed on 
  those sites likely to be involved in possible nonattainment decisions. Once the 
  initial attainment/nonattainment designations have been made, the Agency recommends 
  focusing 80 percent of the QA activity (collocated monitors and FRM audits) at 
  sites with concentrations greater than or equal to 90 percent of the mean annual PM 
  sub 2.5 NAAQS (or 24-hour NAAQS if that is affecting the area); this percentage 
  will be 100 percent if all sites have concentrations above either NAAQS. The 
  remaining 20 percent of the QA activity would be at sites with concentrations less 
  than 90 percent of the PM sub 2.5 NAAQS. If an organization has no sites at 
  concentration ranges greater than or equal to 90 percent of the PM sub 2.5 NAAQS, 
  the Agency recommends 60 percent of the QA activity be at sites among the highest 
  25 percent for all PM sub 2.5 sites in the network. The Agency understands the 
  initial selection of sites will likely be subjective and based upon the experience 
  of State and local organizations.
  
      Other data assessment requirements for PM sub 2.5 monitoring networks are 
  patterned after the current requirements for PM sub 10 networks and are intended to 
  quantify the monitoring network's total precision and bias. PM sub 2.5 network 
  monitors will be subject to performance assessments for both manual and automated 
  methods, using procedures similar or identical to the current procedures required 
  for PM sub 10 monitoring networks. The Agency received several comments describing 
  incentives for acceptable performance in the QA field. In response to these 
  concerns, EPA intends to reduce the QA burden in accordance with network monitoring 
  and acceptable performance of the QA program. Based upon EPA's yearly data quality 
  assessment, acceptable performance could result in a reduction in the frequencies 
  of QA/QC requirements. Additional details for the incentive program will be 
  provided in the Quality Assurance Handbook for Air Pollution Measurement Systems, 
  Volume II, Ambient Air Specific Methods.
  
      The Agency believes that to develop a national, consistent monitoring network 
  with quantifiable data quality, a quality system must be developed that permits 
  maximum flexibility yet ensures that the measurement uncertainty is known and under 
  control. For this {pg 38775} reason, the Agency has removed the requirement in 
  section 3.3.5 that the paired monitors have the same FRM or equivalent sampler 
  designation number, but now formalizes the 6-day sampling schedule for collocated 
  monitors into the regulation; this was previously described in guidance.
  
      With regard to the requirements for evaluating measurement uncertainty, the 
  estimates of bias within the monitoring network will be evaluated with flow audits 
  (section 3.5.1) and independent FRM audits (see comments concerning section 3.5.3). 
  An audit of the operational flow rate determines bias as performed by the local 
  operators of manual methods for PM sub 2.5 with each sampler each calendar quarter. 
  Using a flow rate transfer standard, each sampler will be audited at its normal 
  operating flow rate. The percent differences between the standard and sampler flow 
  rates will be used to evaluate instrument-specific bias.
  
      Specifically, for Federal Reference and Equivalent automated methods, an 
  additional assessment of the precision will consist of a one-point precision check 
  performed at least once every 2 weeks on each automated analyzer used to measure PM 
  sub 2.5. This precision check is performed by checking the operational flow rate of 
  the analyzer, using a procedure similar to that currently used for PM sub 10 
  network assessments. In addition, an alternative procedure may be used where, under 
  certain specific conditions, 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. This alternative procedure is also made applicable to 
  PM sub 10 methods.
  
      With regard to the proposed requirements in section 3.5.2, (Measurement of 
  precision using collocated procedures for automated and manual methods of PM sub 
  2.5) several commenters felt that invalid data or data of questionable quality 
  should not be a part of the data base, since the general public and many end-users 
  of the data such as consultants and modelers do not always make distinctions about 
  data. Data reporting requirements specify that all valid monitoring data be 
  reported to AIRS. EPA believes that the requirement contained in section 4.1 to 
  report all QA/QC measurements including results from invalid tests is necessary to 
  fully assess the performance of reporting organizations and to allow EPA to 
  recommend appropriate corrective actions. Such data will be flagged so that it will 
  not be utilized for quantitative assessments of precision, bias, and accuracy. EPA 
  also received many comments on the use of collocated samplers to assess precision. 
  Most of these comments advocated an increase in the number of collocated monitors 
  as an alternative to reduce the burden of the independent audit system. Based upon 
  these comments, EPA has reassessed its position on the number of collocated 
  monitors and now requires 25 percent of the total number of monitors for each 
  designated Federal Rand Equivalent Method within a reporting organization to be 
  collocated. To further assess the total precision and bias of the monitoring 
  network, half of the collocated monitors for each designated Federal Reference and 
  Equivalent Method must be collocated with a Federal Reference Method (FRM) 
  designated monitor and half must be collocated with a monitor of the same 
  designated method type as the primary monitor. An example is shown in Table A-2 in 
  40 CFR part 58, Appendix A.
  
      The Agency received numerous comments concerning the burden of the proposed FRM 
  audit procedures for PM sub 2.5 (section 3.5.3), which consisted of having every 
  site audited six times each year with a portable FRM audit sampler. In response to 
  these comments, EPA has reduced the number of audits to 25 percent of the total 
  number of SLAMS PM sub 2.5 sites to be audited 4 times each year. In addition, EPA 
  has reduced the burden of the State and local agencies responsibility for 
  implementing the audits by providing access to the existing EPA National 
  Performance Audit Program (NPAP) or other comparable programs. The details 
  concerning the assessment of the resulting data will be published in EPA's Quality 
  Assurance Handbook for Air Pollution Measurement Systems, Volume II, Ambient Air 
  Specific Methods.
  
      4. Reporting requirements. EPA received several comments concerning the 
  adequacy of QA reporting requirements (section 4). The Agency has addressed these 
  comments by strongly encouraging earlier QA data submittal in order to assist the 
  State and local agencies in controlling and evaluating the quality of the ambient 
  air SLAMS data.
  
      5. Data quality assessment. In response to several comments concerning the 
  adequacy of the QA data assessment procedures for the PM sub 2.5 program, including 
  parts of proposed section 6.0, EPA developed a new section 5.5 to consolidate and 
  simplify the procedures and calculations for the precision, accuracy, and bias 
  measurements used to quantify PM sub 2.5 data quality. The quality assurance system 
  has been nested in such a manner that will allow for the assessment of total 
  measurement bias and precision, as well as portions of the measurement system (i.e. 
  field operations, laboratory operations, etc.). Four distinct quality control 
  checks and audits are implemented to evaluate total measurement uncertainty: (1) 
  Determine instrument accuracy and instrument bias from flow rate audits, (2) 
  determine precision from collocated monitors where the duplicate monitor has the 
  same method designation, (3) determine a portion of the measurement bias from 
  collocated monitors where the duplicate sampler is an FRM device, and (4) determine 
  total measurement bias from FRM audits. This design will allow for early 
  identification of data quality issues in the measurement phases (field/laboratory 
  operations) where they may be occurring and therefore, effective implementation of 
  corrective actions.
  
      6. FRM audit requirements. The Agency received many comments concerned with the 
  burden the proposed FRM audit system (the deleted Section 6: Annual Operational 
  Evaluation of PM sub 2.5 Methods) would put upon the individual State and local air 
  pollution agencies. Based upon the numerous comments, the Agency has re- assessed 
  its position concerning the audit system. The Agency reduced this burden by 
  providing the State and local agencies the flexibility to access the existing NPAP 
  program or comparable program, additionally reducing the burden to 25 percent of 
  the total number of SLAMS PM sub 2.5 sites each year, and reducing the frequency of 
  the audits to 4 per year. EPA has removed section 6.0 from the regulations and 
  incorporated the appropriate information into other sections within 40 CFR part 58, 
  Appendix A. Additional information will be provided in the Quality Assurance 
  Handbook for Air Pollution Measurement Systems, Volume II, Ambient Air Specific 
  Methods.
  
  O. Appendix C - Ambient Air Quality Monitoring Methodology
  
      EPA proposed that 40 CFR part 53, subpart C, be amended to allow the use of 
  certain PM sub 10 monitors as surrogates for PM sub 2.5 monitors for purposes of 
  demonstrating compliance with the NAAQS. The proposal further stated however, 
  following the measurement of a PM sub 10 concentration higher than the 24-hour PM 
  sub 2.5 standard or an annual average concentration higher than the annual average 
  PM sub 2.5 standard, the PM sub 10 monitor would have to be replaced with a PM sub 
  2.5 monitor. In the proposal of Appendix C, EPA also discussed the use of several 
  types of PM sub 2.5 samplers at a SLAMS that are not designated as a {pg 38776} 
  reference or equivalent method under 40 CFR part 53. First, EPA proposed the use of 
  certain nonreference/nonequivalent PM sub 2.5 methods that could 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 PM sub 
  2.5, as specified of 40 CFR part 53, subpart C 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 the proposed Appendix A to 40 CFR part 53, at twice the 
  normal evaluation interval. A method that meets these proposed requirements would 
  not become an equivalent method, but the method could be used at that particular 
  SLAMS site for any regulatory purpose. Second, EPA discussed the use of CAC methods 
  described in Sec. 58.13(f) which are intended to supplement a reference or 
  equivalent manual method at certain SLAMS, so that the manual method could reduce 
  its sampling frequency from every day to once in 3 days. In addition, the proposed 
  Appendix C clarifies that the monitoring data obtained with CAC methods would be 
  restricted to use for the purposes of the proposed Sec. 58.13(f) and would not be 
  used for making comparisons to the NAAQS. Finally, the proposal also described 
  samplers for fine particulate matter used in the IMPROVE network (hereafter termed 
  IMPROVED samplers) and clarified that IMPROVE samplers, although not designated as 
  equivalent methods, could be used in SLAMS for monitoring regional background 
  concentrations of fine particulate matter.
  
      Some commenters questioned the proposed use of PM sub 10 samplers as 
  substitutes for PM sub 2.5 samplers to satisfy requirements for PM sub 2.5 SLAMS 
  monitoring. EPA reassessed the logic behind this proposal and agreed with 
  commenters that substitute samplers should not be allowed. In order for a PM sub 10 
  sampler to be a substitute PM sub 2.5 sampler, the annual average PM sub 10 would 
  have to be less than 15  mu g/m sup 3 and the annual maximum 24-hour PM sub 10 
  would have to be less than 65  mu g/m sup 3. This situation would not be 
  representative of community-oriented monitoring, would only exist at a few rural 
  locations and would not even provide useful information about PM sub 2.5 background 
  concentrations; therefore EPA has deleted this provision from Appendix C.
  
      Appendix C is being amended to add a new section 2.4 continuing provisions that 
  allow the use of a PM sub 2.5 method that had not been designated as a reference or 
  equivalent method under 40 CFR part 53 at a SLAMS under special conditions. Such a 
  method will be allowed to be used at a particular SLAMS site to make comparisons to 
  the NAAQS if it meets the basic requirements of the test for comparability to a 
  reference method sampler for PM sub 2.5, as specified in 40 CFR part 53, subpart C, 
  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 will then be further subjected to the operating 
  precision and accuracy requirements specified in 40 CFR part 53, Appendix A, at 
  twice the normal evaluation interval. A method that meets these requirements will 
  not become an equivalent method, but can be used at that particular SLAMS site for 
  any regulatory purpose. The method will be assigned a special method code, and data 
  obtained with the method will be accepted into AIRS as if they had been obtained 
  with a reference or equivalent method. This provision will allow the use of non-
  conventional PM sub 2.5 methods, such as optical or open path measurement methods, 
  which would be difficult to test under the equivalent method test procedures 
  proposed for 40 CFR part 53.
  
      In addition, Appendix C is being amended to add a new section 2.5 to clarify 
  that CAC methods for PM sub 2.5 approved for use in a SLAMS under new provisions in 
  Sec. 58.13(f) will not become de facto equivalent methods as proposed. This applies 
  to methods that have not been designated equivalent or do not satisfy the 
  requirements of section 2.4 previously described. In response to recommendations 
  that IMPROVE samplers be allowed for use at core background and core transport 
  sites, EPA is revising section 2.9 to define 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 and regional 
  transport concentrations of fine particulate matter.
  
      Finally, minor changes are being made 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.
  
  P. Appendix D - Network Design For State and Local Air Monitoring Stations (SLAMS), 
  National Air Monitoring Stations (NAMS) and Photochemical Assessment Monitoring 
  Stations (PAMS)
  
      1. Section 2.8.1 - Specific design criteria for PM sub 2.5. The proposed 
  regulation contained language regarding the implementation of spatial averaging 
  through the design of PM sub 2.5 monitoring networks. MPAs and SAZs were introduced 
  to conform to the population-oriented, spatial averaging approach taken in the 
  proposed PM sub 2.5 NAAQS under 40 CFR part 50. While this proposed approach is 
  more directly related to the epidemiological studies used as the basis for the 
  proposed revisions to the particulate matter NAAQS, it recognized that the use of 
  MPAs and SAZs introduced greater complexity into the network design process and the 
  comparison of observed values to the level of the PM sub 2.5 annual NAAQS.
  
      A great number of comments were received concerning the communication and 
  complexity of spatial averaging, the selection of monitors, and the need for 
  providing flexibility in specifying network designs and spatial averaging given 
  that the nature and sources of fine particles vary from one area to another.
  
      In response to concerns about the implementation and communication of spatial 
  averaging, EPA is clarifying the requirement for SAZs by changing some terminology. 
  EPA is also making it clear that the annual mean PM sub 2.5 from a single properly 
  sited monitor that is representative of community-wide exposures or an average of 
  annual mean PM sub 2.5 concentrations produced by one or more of such monitors that 
  meet siting requirements and other constraints as set forth in this rulemaking can 
  be compared to the PM sub 2.5 annual standard. Specifically, this rule indicates 
  that comparisons to the annual PM sub 2.5 standard can be made through the use of 
  individual monitors or the annual average of monitors in specific CMZs. Community-
  oriented monitors should be used for these comparisons. This approach will provide 
  State and local agencies with additional flexibility in defining community-wide air 
  quality and in designing monitoring networks. The annual average PM sub 2.5 
  concentration from one or more monitoring sites within a CMZ may be averaged to 
  produce an alternative indicator of annual average community-wide air quality. 
  However, the criteria for establishing CMZs have been modified (compared to the 
  previous SAZs) so that initial monitors will be located in those {pg 38777} areas 
  expected to have the highest community-oriented concentrations. It should be noted 
  that many of the sites meeting the siting, monitoring methodology, and other 
  monitoring requirements in 40 CFR part 58 include population- oriented SPMs and 
  industrial monitors.
  
      The eligible core monitors in a CMZ still must be properly sited and meet the 
  constraints specified in section 2.8.1.6 of 40 CFR part 58, Appendix D. The term 
  SAZ has been replaced with CMZ and zone throughout Appendix D. If the State chooses 
  to make comparisons to the annual PM sub 2.5 NAAQS directly with individual 
  monitors that use the siting requirements of section 2.8.1.6.3 of 40 CFR part 58, 
  Appendix D then it is not required to perform the analyses needed to establish a 
  CMZ. A State still would be expected to justify that the site meets the specified 
  siting requirements and is representative of community-wide exposures. Then it 
  would not be expected, apriori, to define the boundaries of zones within which the 
  monitoring data would be averaged. This section, that was proposed as "Monitoring 
  Planning Areas and Spatial Averaging Zones," has been retitled as "Specific Design 
  Criteria for PM sub 2.5."
  
      2. Section 2.8.1.3 - Core monitoring stations for PM sub 2.5. The proposed 
  regulations described requirements for the numbers of SLAMS sites including core 
  SLAMS. To provide a minimal PM sub 2.5 network in all high population areas for 
  protection of the annual and 24-hour PM NAAQS, each required MPA was proposed to 
  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 in residential areas or 
  where people spend a substantial part of the day. In addition to the population-
  oriented monitoring sites, core monitors would also be established for regional 
  background and regional transport monitoring.
  
      To permit interface with measurements of ozone precursors and related emission 
  sources that may contribute to PM sub 2.5, an additional core monitor collocated at 
  a PAMS site was proposed to be required in those MSAs where both PAMS and PM sub 
  2.5 monitoring are required. The core monitor to be collocated at a PAMS site would 
  be considered to be part of the MPA PM sub 2.5 SLAMS network and would not be 
  considered to be a part of the PAMS network as described in section 4 of 40 CFR 
  part 58, Appendix D. Each SAZ in a required MPA was proposed to have at least one 
  core monitor; SAZs in optional MPAs were proposed to have at least one core 
  monitor; and SAZs were proposed to have at least one core site for every four 
  SLAMS.
  
      Several commenters addressed issues related to the number of core SLAMS, 
  population-oriented SLAMS, and other SLAMS. Numerous commenters supported 
  increasing the number of stations while few supported decreasing the number of 
  stations. In addition, some commenters addressing the issue of spatial averaging 
  also suggested that more monitors might be needed to address less populated areas 
  and areas near hot spots. A few commenters suggested that large States or 
  geographic areas might require several regional background or regional transport 
  sites and that increased monitoring in rural or remote areas would be needed to 
  establish naturally occurring concentrations produced by biogenic sources.
  
      EPA agrees with commenters that more monitors are needed to address smaller 
  communities, larger MSAs with several source categories of fine particulate 
  emissions, to address coverage for multiple sites in optional CMZs, regional 
  transport monitoring upwind of the major population centers in the country, and 
  additional sites near population-oriented pollution hot spots. Accordingly, EPA has 
  revised the regulation to increase the number of required core SLAMS and other 
  SLAMS. These changes result in approximately 220 more required sampling sites, 
  nationally, as compared to the number proposed (850 versus 629). At least one core 
  SLAMS is now required in any MSA with a population greater than 200,000. EPA is 
  requiring additional sites in all MSAs with population greater than 1 million in 
  accordance with the following table:
  
  
   Table 1.-Required Number of Core SLAMS According to MSA
   Population
   
   MSA Population        Minimum Required No.
                         of Core Sites fn a
   
   >1 M                  3
   >2 M                  4
   >4 M                  6
   >6 M                  8
   >8 M                  10
   
   fn  a Core SLAMS at PAMS are in addition to these numbers.
   
   
  This section, which was proposed as section 2.8.2.1, has been renumbered as section 
  2.8.1.3.
  
      As discussed in Sec. 58.13, Operating Schedule, all PM sub 2.5 SLAMS are 
  required to have a minimum operating schedule of once every 3 days, except for a 
  subset of at least two core PM sub 2.5 sites per MSA with population greater than 
  500,000 and one site in each PAMS area that is required to conduct daily sampling 
  as proposed.
  
      3. Section 2.8.1.4 - Other PM sub 2.5 SLAMS locations. EPA is retaining the 
  requirement to have a minimum of one regional background and one regional transport 
  site per State and recognizing the need for exceptions when appropriate, 
  particularly in small States; however, these sites are no longer designated as core 
  SLAMS. EPA also is requiring additional SLAMS monitors based upon the State 
  population less the population in all required MSA monitoring areas (i.e., MSAs 
  greater than 200,000), to provide population coverage throughout the State, 
  particularly in States with fewer urbanized areas. For this remaining population 
  there should be one additional SLAMS per 200,000 population. These additional sites 
  may be used to satisfy any SLAMS objective anywhere in the State including 
  population areas (large cities or small towns) or regional transport in rural 
  areas. The requirement for the additional SLAMS is over and above the requirement 
  for one regional background and regional transport site per State as mentioned 
  above. This section, which was proposed as section 2.8.2.2, has been renumbered as 
  section 2.8.1.4. For planning purposes, EPA expects that the total number of sites 
  in a mature, fully-developed PM sub 2.5 network will exceed these required 
  minimums. The projected total number is 1,500 sites, as compared to the proposed 
  1,200 sites. This is an increase of 25 percent compared to the number proposed and 
  is based on the recognized need for more monitoring in smaller communities, more 
  monitors in larger MSAs with several source categories of fine particulate 
  emissions, the possible need for multiple sites in optional CMZs, the need to 
  support regional transport monitoring upwind of the major population centers in the 
  country, and the need for additional sites near pollution hot spots.
  
      4. Section 2.8.1.5 - Additional PM sub 2.5 Analysis Requirements. EPA 
  recognizes the need for chemical speciation of particulate matter. Such data are 
  needed to characterize PM sub 2.5 composition and to better understand the sources 
  and processes leading to elevated PM sub 2.5 concentrations. Because of the costs 
  associated with conducting filter analysis on a routine basis, however the {pg 
  38778} proposal only required filters to be archived so they would be available for 
  subsequent chemical analysis on an as needed basis. EPA recognizes that there is a 
  need for speciation and other specialized monitoring efforts that were not 
  specifically required by the proposed rule. Accordingly, EPA intended to give these 
  PM monitoring efforts high priority in its section 105 grants program.
  
      Many commenters supported the concept of chemical speciation, noting that 
  speciation was essential for identifying all of the components of fine particles 
  and developing control strategies. Some commenters recommended that the program be 
  conducted under national or regional supervision to ensure consistency and reduce 
  costs, and that routine chemical analyses are conducted in a centralized 
  laboratory. EPA also received several comments on the proposed archival 
  requirements. Some commenters suggested that if chemical speciation was required, 
  the filter archival requirement could be eliminated. Other commenters noted that 
  the long-term archival requirements placed additional resource burdens on agencies, 
  and that possible filter degradation and/or bias could result from archiving 
  samples prior to analysis.
  
      Based on these comments, the Agency reassessed its position concerning chemical 
  speciation as an optional part of the PM sub 2.5 monitoring program. Although 
  speciation is resource intensive, EPA believes that its overall value in satisfying 
  control strategy and other data needs justifies the added expense. Chemical 
  speciation is critically important for the implementation efforts associated with 
  air quality programs. Specific subject areas supported by chemical speciation 
  include source attribution analysis (i.e., determining the likely mix of sources 
  impacting a site) and emission inventory and air quality model evaluation. Emission 
  inventory and modeling tools are used to develop sound emission reduction 
  strategies. Speciated data are especially critical for air quality model evaluation 
  since resolved chemical measurements provide greater assurance that acceptable 
  model behavior results from appropriate process characterization rather than 
  through the collective effect of compensating errors. Speciated data provide 
  greater ability to identify the causes of poor model performance and implement 
  corrective actions. After strategies are developed and controls are implemented, 
  chemically resolved PM sub 2.5 data provide a tracking and feedback mechanism to 
  assess the effectiveness of controls and, if necessary, provide a basis for 
  adjustment. Chemical speciation provides an additional quality check on data 
  consistency since a basis for comparing the sum of individual components (i.e., 
  speciated data) with total mass measurement is available. Also, speciated data 
  supports the forthcoming regional haze program by providing a basis for developing 
  reliable estimates of seasonal and annual average visibility conditions. Chemically 
  resolved data should provide more complete data for future health studies. EPA 
  believes that speciation should be part of the final PM sub 2.5 monitoring program 
  due to the collective value of speciation. However, the Agency also believes that 
  flexibility must be provided to the States to tailor efforts to the needs of 
  specific areas. Based on public comments, a minimum chemical speciation trends 
  network will be required to address the needs discussed above.
  
      Based on this requirement to collect speciated data at NAMS sites, EPA is 
  eliminating the requirement to archive filters from NAMS. However, all other SLAMS 
  sites will still be required to archive filters for a minimum of 1 year after 
  collection. Access to these archived filters for chemical speciation would be 
  helpful in cases where: (1) Exceedances or near exceedances of the standard have 
  occurred and additional information and data are needed to determine more precisely 
  possible sources contributing to the exceedances or high concentrations, and (2) 
  certain sites may have shown marked differences in air quality trends at the local 
  or national level for no apparent reason and analysis of filters from more than one 
  site might be required to determine the reason(s) for the differences. EPA intends 
  to assign a high priority to this program through its section 105 grant allocation 
  program and will issue guidance describing the monitoring methods and scenarios 
  under which speciation should be performed. The FRM described in 40 CFR part 50, 
  Appendix L, is finalized as a single-filter based method. Therefore, supplementary 
  monitoring equipment that, for example, permits the use of additional filter media 
  will be needed to perform the appropriate speciation. Additional details on the 
  monitoring methodology for performing speciation and related information on filter 
  handling and/or storage will be addressed in forthcoming EPA guidance.
  
      EPA is now instructing the States to initiate chemical speciation in accordance 
  with forthcoming EPA guidance at PM sub 2.5 core sites collocated at approximately 
  25 PAMS sites and at approximately 25 other core sites for a total of approximately 
  50 sites nationwide. These sites would be selected as candidates for future NAMS 
  designation. Depending on available resources, chemical speciation could be 
  expanded to additional sites in the second and third years. The requirement to 
  collect speciated data will be reexamined after 5 years of data collection. Based 
  on this review, the EPA Administrator may exempt some sites from collecting 
  speciated data. At a minimum, chemical speciation will include analysis for metals 
  and other elemental constituents, selected anions and cations, and carbon.
  
      EPA recognizes that advantages related to consistency, quality assurance and 
  scales of economy would result from using centralized laboratories for conducting 
  chemical analyses. However, EPA is concerned about the available laboratory 
  capacity for meeting the needs of a national PM sub 2.5 speciation network. Several 
  options are under consideration that include developing new central and regional 
  laboratories and exploring the use of existing federal and State facilities. This 
  section, which was proposed as section 2.8.2.4, has been renumbered as section 
  2.8.1.5.
  
      5. Section 3.7.6 - NAMS speciation. Consistent with the previous discussion on 
  speciation, the requirement to establish a subset of approximately 50 NAMS sites 
  for routine speciation is described in a new section 3.7.6 of 40 CFR part 58, 
  Appendix D. The approximately 50 sites will include the ones collocated at PAMS and 
  approximately 25 other sites to be selected by the EPA Administrator, in 
  consultation with the Regional Administrators and the States. After 5 years of data 
  collection, the EPA Administrator may exempt some sites from collecting speciated 
  data. The number of NAMS sites at which speciation will be performed each year and 
  the number of samples per year will be determined in accordance with EPA guidance. 
  The subsequent sections of section 3.7 have been renumbered accordingly.
  
  Q. Appendix E - Probe and Monitoring Path Siting Criteria for Ambient Air Quality 
  Monitoring
  
      The proposed revisions to this Appendix consisted of relatively minor changes 
  in the siting criteria to expand the requirements to include PM sub 2.5. Minor 
  changes were made to the example monitoring location in section 8.1 of the proposed 
  revisions to 40 CFR part 58, Appendix E, to replace "mid- {pg 38779}  town 
  Manhattan in New York City" with "central business district of a Metropolitan 
  area."
  
  R. Appendix F - Annual Summary Statistics
  
      A new section was proposed to be added to 40 CFR part 58, Appendix F, to 
  include annual summary statistics for PM sub 2.5. No changes were made to the 
  proposed revisions.
  
  S. Review of Network Design and Siting Requirements for PM
  
      1. PM sub 10. The network design and siting requirements for the annual and 24-
  hour PM sub 10 NAAQS will continue to emphasize identification of locations at 
  maximum concentrations. The PM sub 10 network itself, however, will be revised 
  because the new PM sub 2.5 standards will likely be the controlling standards in 
  most situations.
  
      The new network for PM sub 10 will be derived from the existing network of 
  SLAMS, NAMS, and other monitors generically classified as SPMs which include 
  industrial and special study monitors. Population-oriented PM sub 10 NAMS will 
  generally be maintained as will other key sampling locations in existing 
  nonattainment areas, and in areas whose concentrations are near the levels of the 
  revised PM sub 10 NAAQS. Currently approved reference or equivalent PM sub 10 
  samplers can continue to be utilized. The revised network will ensure that analysis 
  of national trends in PM sub 10 can be continued, that air surveillance in areas 
  with established PM emission control programs can be maintained, and that the PM 
  sub 10 NAAQS will not be jeopardized by additional growth in PM sub 10 emissions. 
  PM sub 10 sites should be collocated with new PM sub 2.5 sites at key community-
  oriented monitoring stations so that better definition of fine and coarse 
  contributions to PM sub 10 can be determined to provide a better understanding of 
  exposure, emission controls, and atmospheric processes. PM sub 10 sites not needed 
  for trends or with maximum concentrations less than 60 percent of the NAAQS should 
  be discontinued in a longer-term PM sub 10 network.
  
  fn 2 The sampling frequency at all PM sub 10 sites can be changed to a minimum of 
  once in 3 days, which will be sufficient to make comparisons with the new PM sub 10 
  standards at most locations. Locations without high 24- hour concentrations of PM 
  sub 10 (e.g., 140  mu g/m sup 3) may be exempted from this provision, and their 
  sampling frequency reduced to a minimum of once in 6 days.
  
  fn 2 Memorandum from William F. Hunt, Jr., Director, Emissions, Monitoring, and 
  Analysis Division dated April 22, 1997, to EPA Regional Directors entitled Ambient 
  Monitoring Reengineering (found in Docket A-96-51).
  
      2. PM sub 2.5. Consistency with the new PM sub 2.5 NAAQS demands the adoption 
  of new perspectives for identifying and establishing monitoring stations for the PM 
  sub 2.5 ambient air monitoring network. First, sites which are representative of 
  community-wide air quality shall be the principal focus of the new PM sub 2.5 
  monitoring program; however, all eligible population-oriented PM sub 2.5 sites 
  (including regional background and regional transport sites) will be used for 
  comparisons to the new NAAQS. Second, eligible SLAMS and other eligible SPMs may be 
  averaged within properly defined CMZs to better characterize exposure and air 
  quality for comparison to the annual PM sub 2.5 NAAQS. Third, population-oriented 
  PM sub 2.5 SLAMS and SPMs representative of unique microscale or middle scale 
  impact sites would not be eligible for comparison to the annual PM sub 2.5 NAAQS 
  and would only be compared to the 24-hour PM sub 2.5 NAAQS. The 24-hour PM sub 2.5 
  NAAQS is intended to supplement the annual PM sub 2.5 standard by providing 
  additional protection at these small spatial scales. A violation of the annual PM 
  sub 2.5 NAAQS at localized hot spot and other areas of a small spatial scale (i.e., 
  less than 0.5km in diameter) are not reflective of the data used to establish the 
  annual PM sub 2.5 NAAQS. It is also not indicative of a greater area-wide problem 
  which would initiate the need for an area-wide implementation strategy. Clearly, 
  the combination of careful network design, i.e., one that identifies the 
  differences in monitor locations, and an implementation policy that strives to 
  develop effective strategies optimizing regional and local efforts is required to 
  address the intent of the PM sub 2.5 NAAQS.
  
      The new network for PM sub 2.5 consists of a core network of community- 
  oriented SLAMS monitors (including certain SLAMS collocated at PAMS), other SLAMS 
  monitors (including background and regional transport sites), a NAMS network for 
  long-term monitoring for trends purposes, and a supplementary network of SPMs. 
  Daily sampling is required at a subset of core SLAMS located in MSAs with 
  population greater than 500,000 and at core SLAMS collocated at PAMS sites. This 
  will provide more accurate and complete information on population exposure. One in 
  3-day sampling is required at NAMS and at all other SLAMS, except when exempted by 
  the Regional Administrator, in which case one in 6-day sampling is required. 
  Frequent measurements are important to characterize the day-to-day variability in 
  PM sub 2.5 concentrations, and to understand episodic behavior of PM sub 2.5. 
  Routine chemical speciation of PM sub 2.5 will be required for a small subset of 
  the core SLAMS. This is necessary to establish and track effective emission control 
  strategies to assure protection of the NAAQS. These sites shall be part of the 
  future PM sub 2.5 NAMS network. Overall, many of the new PM sub 2.5 sites are 
  expected to be located at existing PM sub 10 sites, that are representative of 
  monitoring oriented exposures and would be collocated with some PAMS sites.
  
      The concepts that address the intent of PM sub 2.5 network for making 
  comparisons to the NAAQS are embodied through: (1) Monitoring planning areas; (2) 
  specially coded sites including community-oriented (core) SLAMS, regional transport 
  and regional background SLAMS, and other SLAMS or SPMs whose data would be used to 
  compare to the levels of the annual and 24-hour PM sub 2.5 NAAQS; (3) SLAMS or SPMs 
  representative of unique population-oriented microscale or middle scale locations 
  that are only eligible for comparison to the 24-hour PM sub 2.5 NAAQS, and (4) 
  individual community-oriented sites or CMZs to correspond to the spatial averaging 
  approach defined by the annual PM sub 2.5 NAAQS.
  
      Core sites are community-representative monitoring sites which are among the 
  most important SLAMS for identifying areas that are in violation of the PM sub 2.5 
  NAAQS and to be used for the associated SIP planning process. Because of their 
  generally larger spatial scales of representativeness, the core sites are the sites 
  most likely to be eligible for spatial averaging and are also vital in order to 
  establish the boundaries of potential areas of violation of the NAAQS that would be 
  reflective of the areas of highest population exposure to fine particles. Core 
  sites are neighborhood scale in their spatial dimensions. Core SLAMS and specific 
  SPM monitoring locations which are eligible for spatial averaging must be 
  identified in the PM monitoring network description, satisfy criteria outlined in 
  Appendix D, and be approved by EPA. In accordance with information to be specified 
  by the AIRS guidance, the State shall assign the appropriate monitoring site code 
  when reporting these data to EPA.
  
      Regional transport and regional background sites are located outside major 
  metropolitan areas and would generally be upwind of one or more high concentration 
  PM sub 2.5 impact areas. These sites are expected to be in areas {pg 38780} of 
  relatively low population density or in unpopulated regions. The collection of data 
  at these sites is encouraged because they are critical for the complete 
  understanding of potential pollutant transport and for the development and 
  evaluation of emission control strategies. Although violations of the NAAQS may be 
  observed at these sites, the interpretation and use of such data observed at 
  regional transport and regional background locations will be addressed in the PM 
  implementation program.
  
      SLAMS monitoring locations generally should reflect the population-oriented 
  emphasis of the new NAAQS' population risk management approach and its data would 
  be used for NAAQS comparisons. SPMs, on the other hand, could represent a variety 
  of monitoring situations, some of which are not appropriate for comparison to the 
  PM sub 2.5 standards. This includes monitoring at non-population-oriented hot spots 
  or special emissions characterization sites that do not meet EPA siting criteria or 
  required SLAMS monitoring methodology, but provide valuable planning information to 
  support the SIP process. In addition, certain SLAMS and SPMs that represent small 
  spatial scales (i.e., sites that are classified as microscale or middle scale, in 
  accordance with Appendix D) would not represent average, community- oriented air 
  quality. In general, such locations would be relatively close to a single PM 
  emission source or a collection of small local sources. An example of such a 
  location is a unique microscale site in a non-residential part of an urban area and 
  which may be zoned industrial. Clearly, such a site should not be called a SLAMS. 
  There might also be SLAMS sites in residential districts which are representative 
  of small maximum concentration impact areas. Due to the greater spatial homogeneity 
  of fine particles, the existence of such small scale impact locations is expected 
  to be much less than that for coarse particles. When SLAMS or SPMs do represent 
  small, unique population-oriented impact areas, they should be used for comparison 
  to the 24-hour PM sub 2.5 standard but not for the annual standard. This is 
  especially true when the site is dominated by a single emission source. In general, 
  these types of small impact sites may be surrounded by broader areas of more 
  homogeneous concentrations which are reflective of community-wide air quality. 
  However, if the State chooses to monitor at a unique population- oriented 
  microscale or middle scale location and the monitoring station meets all applicable 
  40 CFR part 58 requirements (including monitoring methodology), then the data shall 
  be used only for comparison to the 24-hour PM sub 2.5 standard. This is consistent 
  with the underlying rationale of the PM sub 2.5 NAAQS. Such monitors would require 
  a special AIRS code when their data are submitted to EPA, as specified by AIRS 
  guidance.
  
      Exceptions to the use of micro and middle scale PM sub 2.5 for comparison only 
  to the 24-hour standard may exist when micro or middle scale PM sub 2.5 sites 
  represent several small areas in the monitoring domain which collectively identify 
  a larger region of localized high concentration. For example, there may be two or 
  more disjoint middle scale impact areas in a single residential district that are 
  not predominantly influenced by a single PM sub 2.5 emission source. In this case, 
  these small scale sites should be used for comparison to the annual NAAQS. This is 
  because their annual average ambient air concentrations can be interpreted as if 
  they collectively represent a larger scale. In a sense, this situation can be 
  viewed as a neighborhood of small scale impact areas. These concepts and associated 
  requirements are discussed in section 2.8.1 of 40 CFR part 58, Appendix D.
  
      The new network design and siting requirements encourage the placement of PM 
  sub 2.5 monitors both within and outside of population centers in order to: (1) 
  Provide air quality data necessary to facilitate implementation of the PM sub 2.5 
  NAAQS, and (2) augment the existing visibility fine particle monitoring network. 
  The coordination of these two monitoring objectives will facilitate implementation 
  of a regional haze program and lead to an integrated monitoring program for fine 
  particles.
  
      To achieve the appropriate level of air quality surveillance in such areas, EPA 
  believes it is important to coordinate and integrate the regional background and 
  regional transport monitoring sites specified in this final rule with the existing 
  IMPROVE monitors that have been in place in a number of locations around the 
  country since the late 1980s to characterize fine particulate 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 forthcoming to support this 
  program. 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 rule, 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 PM sub 2.5 
  and visibility monitoring networks in the most efficient and effective ways to meet 
  the collective goals of these programs. It is EPA's intent that monitoring 
  conducted for purposes of the PM sub 2.5 primary and secondary NAAQS (including 
  regional background and regional transport sites), and for visibility protection be 
  undertaken as one coordinated national PM sub 2.5 monitoring program, rather than 
  as a number of independent networks.
  
      Although the major emphasis of the new PM sub 2.5 network 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 
  analyses are suggested concerning the location of nephelometers (or other 
  continuous PM measuring devices) at some core monitoring sites and the collection 
  of meteorological data at core SLAMS sites (including background and regional 
  transport sites).
  
  T. Resources and Cost Estimates for New PM Networks
  
      The proposed rules contained a discussion of the costs associated with the 
  start-up and implementation of a PM sub 2.5 network and the phase-down of the 
  existing PM sub 10 network.
  
      1. Resources and costs. Several commenters expressed concern about the costs of 
  the proposed monitoring and QA/QC requirements. Most commenters wanted EPA to 
  provide the funds to meet the increased effort and costs with new monies to the 
  agencies, noting that implementing the network in a timely manner will depend 
  heavily on timely grant assistance from EPA.
  
      Numerous commenters expressed concern that either not enough monitoring money 
  was projected or that the program would be an unfunded mandate. Commenters felt 
  that EPA should budget the funds necessary to develop an adequate PM sub 2.5 
  network that will support all SIP obligations, including support for speciation. 
  Funds to implement a new monitoring network should include one-time funding to {pg 
  38781} procure sampling, calibration, laboratory, and audit equipment, plus annual 
  funding to support field and laboratory operations.
  
      Several commenters felt that EPA estimates were too low, citing underestimates 
  for additional operational, analytical, and equipment costs including daily 
  sampling; speciation; startup for new monitoring locations; laboratory 
  modifications; operator training; travel; data collection and reporting; greater QA 
  equipment and manpower needs; field testing of reference and equivalent methods; 
  and continuous monitors. No commenter felt that EPA estimates were too high.
  
      A few commenters addressed the suggested portions of the total monitoring 
  program cost for speciation. Several commenters suggested that the cost of 
  requiring speciation could be reduced by limiting the requirement to a subset of 
  the daily monitoring sites, or offset by eliminating the requirement for daily 
  sampling, noting that any cost savings would be overwhelmed by the greater number 
  of PM sub 2.5 sites and the number of sites conducting everyday sampling.
  
      EPA understands the complexities and resource demands required by State and 
  local agencies in establishing and implementing the new regulations. In its review 
  of the comments on the use of the proposed Federal reference sampler and associated 
  quality assurance requirements, the Agency has published more cost-effective 
  requirements with this final rule for monitoring network design, methodology, and 
  quality assurance. Likewise, EPA recognizes the subsequent need for it to provide 
  technical and financial assistance. In this regard, some control agencies have used 
  FY-97 grant allocations to procure PM sub 2.5 prototype instruments or upgrade 
  their filter weighing facilities. Additionally, the Agency has designated 
  approximately $10,935,000 in section 105 grant monies for distribution to States in 
  FY-98. EPA intends to assign a high priority to the PM sub 2.5 monitoring program 
  through its section 105 grants, and additional grant dollars have been earmarked by 
  EPA for subsequent years which should ensure successful implementation of the PM 
  sub 2.5 monitoring program.
  
      2. Revised cost analysis. In response to comments on cost estimation and new 
  requirements described earlier, EPA has revised its estimates for the projected PM 
  sub 10 and PM sub 2.5 networks. EPA believes that it has both improved its cost 
  estimates and more adequately addressed the needs for the PM monitoring program. 
  The net costs associated with the final PM rules promulgated today include the 
  start-up and implementation costs associated with the new PM sub 2.5 network and 
  the cost savings associated with phase-down of the existing PM sub 10 network. The 
  estimated costs in the preamble have been revised to reflect changes to the 
  regulations based on comments received on the proposed changes in 40 CFR parts 50, 
  53, and 58. In particular, PM sub 2.5 network costs have been revised to reflect an 
  increase in the number of sites to 1,500, newer cost estimates for prototype 
  samplers, equipping many sites with sequential samplers to provide for greater 
  operational flexibility, reducing the number and frequency of audits with federal 
  reference method samplers, and providing for additional multi-filter sampling to 
  determine PM sub 2.5 constituent species. In addition, PM sub 10 network costs have 
  been revised to reflect an increase in the remaining number of PM sub 10 sites to 
  900 and a sampling frequency of once every 3 days (instead of once every 6 days, as 
  proposed) for those sites that previously had been sampling everyday, every 2 days, 
  or every 6 days.
  
      Table 2 shows the PM sub 2.5 network phase-in data including number of sites 
  and samplers, costs for capital equipment, sampling and quality assurance, filter 
  analyses, and special studies. Table 3 provides a breakdown of the costs associated 
  with the filter analyses. Table 4 provides a breakdown of the phase-down costs for 
  the PM sub 10 network. The costs are shown for a current network of approximately 
  1,650 sites in 1997 and the phase-down to a future projected network of 900 sites. 
  Table 5 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 requirements. Tables 2 through 5 follow.
  
  
   Table  2.- PM sub 2.5  Network Costs
   
    Thousands of Actual Dollars 
   
   Year            Number of       Number of       Capital Cost
                   Sites           Samplers fn 1
   
   1997            0               0               $ 4,500
   1998            724             861             $ 8,963
   1999            1,200           1,512           $ 14,877
   2000            1,500           1,887           $ 7,155
   
   Year         Sampling &   Filter       Special      Total Cost
                QA           Analysis     Studies
                             fn 2
   
   1997                                                $ 4,500
   1998         $ 10,216     $ 472        $ 1,426      $ 18,225
   1999         $ 17,938     $ 2,325      $ 3,004      $ 38,143
   2000         $ 26,697     $ 3,649                   $ 37,502
   
   fn 1 The PM sub 2.5 network includes a mature network of 332
   collocated samplers for QA purposes.
   
   fn 2 Three different types of filter analyses are anticipated
   (exceedance analyses, screening analyses, and detailed analyses).
   
   
  
   Table  3.- Cost for PM sub 2.5  Filter Analyses
   
   Type of Filter Analysis                             Estimated
                                                       Cost per
                                                       Sample
   
   Exceedance Analysis                                 $ 200
   High PM sub 2.5 concentration events are analyzed
   for particle size and composition utilizing
   optical or electron microscopy
   Screening Analysis                                  $ 150
   Multi-filter analyses including (1) x-ray
   fluorescence (XRF) for elemental composition
   (crustal material, sulfur, and heavy metals); (2)
   ion chromatography for ions such as sulfate,
   nitrate, and chloride; (3) thermal-optical
   analysis for elemental/organic/total carbon
   Detailed Analysis                                   $ 400
   Analysis for speciated organic composition
   
   
   {pg 38782}
  
  
   Table  4.- PM sub 10  Network Costs
   
    Thousands of Actual Dollars 
   
   Year            Number of       Number of       Capital Cost
                   Sites           Samplers fn 1   to Remove
                                                   Sites
   
   1997            1,650           1,810
   1998            1,450           1,610           $ 137
   1999            1,250           1,410           $ 89
   2000            900             1,060           $ 159
   
   Year            Operation &     Total Cost
                   Maintenance
                   Cost
   
   1997            $ 15,861        $ 15,861
   1998            $ 13,358        $ 13,495
   1999            $ 11,946        $ 12,035
   2000            $ 9,134         $ 9,293
   
   fn 1 The PM sub 10 network includes 160 collocated samplers for
   QA purposes.
   
   
  
   Table  5.- Costs for Particulate Monitoring
   
    In 1997 Dollars 
   
   PM Monitor and        One-Time Capital      Annual Operation &
   Sampling Frequency    Cost                  Maintenance Cost
   
   PM sub 10 1-in-6 day  $ 7,700 to $ 14,800   $ 8,000 to $ 8,900
   sampling schedule
   PM sub 10 1-in-3 day  $ 7,700 to $ 19,400   $ 12,400
   sampling schedule
   PM sub 2.5 1-in-6     $ 9,300 to $ 20,700   $ 11,300 to $ 12,500
   day sampling
   schedule
   PM sub 2.5 1-in-3     $ 12,800 to $ 20,700  $ 17,000 to $ 18,600
   day sampling
   schedule
   PM sub 2.5 every day  $ 12,900 to $ 20,700  $ 20,700 to $ 22,200
   sampling
   Nephelometer          $ 21,000              $ 19,700
   (continuous)
   
   
  V. References
  
      (1) Information Collection Request, 40 CFR Part 58, Ambient Air Quality 
  Surveillance, OMB 2060-0084, EPA ICR No. 0940.14, U.S. Environmental Protection 
  Agency, Office of Air Quality Planning and Standards, Research Triangle Park, NC 
  27711.
  
  VI. Regulatory Assessment 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 
  Recordkeeping Requirements.
  
  B. Paperwork Reduction Act
  
      The information collection requirements contained in this 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 EPA (ICR No. 
  0940.14) and a copy may be obtained from Sandy Farmer, Information Policy Branch, 
  EPA, 401 M St., 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 implement the air quality standards. 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 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, that requires ambient air quality monitoring for purposes 
  of the SIP and reporting of the data to EPA, and section 319, that 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.
  
      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 SIPs; providing dispersion modeling support; developing 
  responsible, cost- effective control strategies; reconciling emission inventories; 
  and developing air quality trends. The collection of PM sub 2.5 data is necessary 
  to support the PM sub 2.5 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 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 rule is estimated to be 785,430 hours. Of {pg 
  38783} this total, 778,826 hours are estimated to be for data reporting, or an 
  average of 5,991 hours for the estimated 130 respondents. The remainder of 6,604 
  hours for recordkeeping burden averages 51 hours for the estimated 130 respondents. 
  The capital operation/maintenance costs associated with this rule are estimated to 
  be $32,463,626. 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 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 part 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.
  
  C. Impact on Small Entities
  
      Pursuant to section 605(b) of the Regulatory Flexibility Act, 5 U.S.C. 605(b), 
  the EPA 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 
  signed into law on March 22, 1995, 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.
  
      EPA has determined that this rule does not contain a Federal mandate that may 
  result in an administrative burden of $100 million or more for State and local 
  governments, in the aggregate, or the private sector in any one year. The Agency's 
  economic analysis indicates that the total incremental administrative cost will be 
  approximately $56,611,000 in 1997 dollars for the 3 years to phase in the network, 
  or an average of $18,820,000 per year for the 3-year implementation period. Table 6 
  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 PM sub 2.5 monitoring include the initial capital costs anticipated in 1997. In 
  addition, this rule imposes no enforceable duties on small businesses.
  
  
   Table 6.-Cost Elements for PM Monitoring
   
   Administrative Cost Based on 3-year Average (thousands of
   constant 1997 dollars)*
   
   Cost/Element          Current              Revised
                         PM sub 10   PM sub 10     PM sub 2.5
   Network design                    $ 0           $ 1,174
   Site installation                 $ 0           $ 1,532
   Sampling & analysis   $ 3,518     $ 2,528       $ 7,915
   Maintenance           $ 1,658     $ 1,192       $ 2,285
   Data management       $ 2,098     $ 1,508       $ 3,370
   Quality assurance     $ 2,940     $ 2,113       $ 3,342
   Supervision           $ 3,350     $ 2,408       $ 3,068
   Summary               $ 13,564    $ 9,749       $ 22,684
   *Totals are rounded
   
   Cost/Element                  Revised        Net Change
                          Totals
   Network design         $ 1,174               $ 1,174
   Site installation      $ 1,532               $ 1,532
   Sampling & analysis    $ 10,443              $ 6,926
   Maintenance            $ 3,477               $ 1,818
   Data management        $ 4,878               $ 2,780
   Quality assurance      $ 5,455               $ 2,515
   Supervision            $ 5,476               $ 2,125
   Summary                $ 32,433              $ 18,820
   *Totals are rounded
   
   
   {pg 38784}
  
  List of Subjects in 40 CFR Parts 53 and 58
  
      Environmental protection, Administrative practice and procedure, Air pollution 
  control, Intergovernmental relations, Reporting and recordkeeping requirements.
  
      Dated: July 16, 1997.
  
  Carol M. Browner,
  
  Administrator.
  
      For the reasons set forth in the preamble, title 40, chapter I, parts 53 and 58 
  of the Code of Federal Regulations are amended as follows:
  
  PART 53- AMENDED 
  
      1. In part 53:
  
      a. 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.
  
      b. 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.
  
      Terms used but not defined in this part shall have the meaning given them by 
  the Act.
  
      Act means the Clean Air Act (42 U.S.C. 1857-1857l), as amended.
  
      Administrator means the Administrator of the Environmental Protection Agency or 
  the Administrator's authorized representative.
  
      Agency means the Environmental Protection Agency.
  
      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, distributor, supplier, or vendor.
  
      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.
  
      Candidate method means a method for measuring the concentration of an air 
  pollutant in the ambient air 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.
  
      Class I equivalent method means an equivalent method for PM sub 2.5 which is 
  based on a sampler that is very similar to the sampler specified for reference 
  methods in Appendix L of this part, with only minor deviations or modifications, as 
  determined by EPA.
  
      Class II equivalent method means an equivalent method for PM sub 2.5 that 
  utilizes a PM sub 2.5 sampler in which an integrated PM sub 2.5 sample is obtained 
  from the atmosphere by filtration and is subjected to a subsequent filter 
  conditioning 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 EPA.
  
       Class III equivalent method means an equivalent method for PM sub 2.5 that has 
  been determined by EPA not to be a Class I or Class II equivalent method. This 
  fourth type of PM sub 2.5 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 are likely 
  to use components and methods other than those specified for reference method 
  samplers.
  
      Collocated describes two or more air samplers, analyzers, or other instruments 
  which sampler the ambient air that are operated silmultaneously 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.
  
      Equivalent method means a method for measuring the concentration of an air 
  pollutant in the ambient air 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.
  
      ISO 9001-registered facility means a manufacturing facility that is either:
  
      (1) An International Organization for Standardization (ISO) 9001-registered 
  manufacturing facility, registered to the ISO 9001 standard (by the Registrar 
  Accreditation Board (RAB) of the American Society for Quality Control (ASQC) in the 
  United States), with registration maintained continuously.
  
      (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 9001-registered facility for the design and manufacture of 
  designated reference and equivalent method samplers and monitors.
  
      ISO-certified auditor means an auditor who is either certified by the Registrar 
  Accreditation Board (in the United States) as being qualified to audit quality 
  systems using the requirements of recognized standards such as ISO 9001, or who, 
  based on information submitted to the EPA, meets the same general requirements as 
  provided for ISO-certified auditors.
  
      Manual method means a method for measuring concentrations of an ambient air 
  pollutant in which sample collection, analysis, or measurement, or some combination 
  therof, is performed manually. A method for PM sub 10 or PM sub 2.5 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 {pg 38785}  
  automatically collecting a series of sequential samples.
  
      PM sub 2.5 sampler means a device, associated with a manual method for 
  measuring PM sub 2.5, designed to collect PM sub 2.5 from an ambient air sample, 
  but lacking the ability to automatically analyze or measure the collected sample to 
  determine the mass concentrations of PM sub 2.5 in the sampled air.
  
      PM sub 10 sampler means a device, associated with a manual method for measuring 
  PM sub 10, designed to collect PM sub 10 from an ambient air sample, but lacking 
  the ability to automatically analyze or measure the collected sample to determine 
  the mass concentrations of PM sub 10 in the sampled air.
  
      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.
  
      Sequential samples for PM samplers means two or more PM samples for sequential 
  (but not necessarily contiguous) time periods that are collected automatically by 
  the same sampler without the need for intervening operator service.
  
      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. 
  Test sampler means a PM sub 10 sampler or a PM sub 2.5 sampler subjected to testing 
  as part of a candidate method in accordance with subparts C, D, E, or F of this 
  part.
  
      Ultimate purchaser means the first person or entity who purchases a reference 
  method or an equivalent method for purposes other than resale.
  
   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 sulfur dioxide (SO sub 2) 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 SO sub 2 and lead will not be considered for reference method 
  determinations under this part.
  
      (2) A reference method for measuring PM sub 10 must be a manual method that 
  meets all requirements specified in Appendix J of part 50 of this chapter and must 
  include a PM sub 10 sampler that has been shown in accordance with this part to 
  meet all requirements specified in subparts A and D of this part.
  
      (3) A reference method for measuring PM sub 2.5 must be a manual method that 
  meets all requirements specified in Appendix L of part 50 of this chapter and must 
  include a PM sub 2.5 sampler that has been shown in accordance with this part to 
  meet the applicable requirements specified in subparts A and E of this part. 
  Further, reference method samplers must be manufactured in an ISO 9001- registered 
  facility, as defined in Sec. 53.1 and as set forth in Sec. 53.51, and the Product 
  Manufacturing Checklist set forth in subpart E of this part must be completed by an 
  ISO-certified auditor, as defined in Sec. 53.1, and submitted to EPA annually to 
  retain a PM sub 2.5 reference method designation.
  
      (b) Automated methods. An automated reference method for measuring carbon 
  monoxide (CO), ozone (O sub 3), and nitrogen dioxide (NO sub 2) 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, PM sub 10 or PM sub 2.5 samplers associated 
  with manual equivalent methods for PM sub 10 or PM sub 2.5 must have been shown in 
  accordance with this part to satisfy the following additional requirements:
  
      (1) A PM sub 10 sampler associated with a manual method for PM sub 10 must 
  satisfy the requirements of subpart D of this part.
  
      (2) A PM sub 2.5 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 PM sub 2.5 Class II equivalent method sampler must satisfy the applicable 
  requirements of subparts C, E, and F of this part.
  
      (4) Requirements for PM sub 2.5 Class III equivalent method samplers 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 and may include selected requirements from 
  subparts C, E, or F of this part or other requirements not contained in this part.
  
      (5) All designated equivalent methods for PM sub 2.5 must be manufactured in an 
  ISO 9001-registered facility, as defined in Sec. 53.1 and as set forth in Sec. 
  53.51, and the Product Manufacturing Checklist set forth in subpart E of this part 
  must be completed by an ISO- certified auditor, as defined in Sec. 53.1, and 
  submitted to EPA annually to retain a PM sub 2.5 equivalent method designation.
  
      (b) Automated methods. (1) Automated equivalent methods for pollutants other 
  than PM sub 2.5 or PM sub 10 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 PM sub 10 must have been shown in 
  accordance with this part to satisfy the requirements of subparts C and D of this 
  part.
  
      (3) Requirements for PM sub 2.5 Class III automated equivalent methods for PM 
  sub 2.5 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 and may include selected 
  requirements from subparts C, E, or F of this part or other requirements not 
  contained in this part.
  
      (4) All designated equivalent methods for PM sub 2.5 must be manufactured in an 
  ISO 9001-registered facility, as set forth in subpart E of this part, and the 
  Product Manufacturing Checklist set forth in subpart E of this part must be 
  completed by an ISO-certified auditor and submitted to EPA annually to retain a PM 
  sub 2.5 equivalent method designation.
  
      (5) All designated equivalent methods for PM sub 2.5 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. {pg 38786}
  
      (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 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 PM sub 2.5 must meet all applicable requirements in Reference 1 of 
  Appendix A of this subpart, using appropriate graphical, nomenclature, and 
  mathematical conventions such as those specified in References 3 and 4 of Appendix 
  A of this subpart.
  
      (3) A copy of a comprehensive operation or instruction manual providing a 
  complete and detailed description of the operational, maintenance, and calibration 
  procedures prescribed for field use of the candidate method and all instruments 
  utilized as part of that method (under Sec. 53.9(a)).
  
      (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.
  
      (K) Appropriate references to Appendix L of part 50 of this chapter; Reference 
  6 of Appendix A of this subpart; 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 EPA. For samplers and automated methods, the manual shall include 
  a clear description of all procedures pertaining to installation, operation, 
  preventive maintenance, and troubleshooting and shall also include parts 
  identification diagrams. The manual may be used to satisfy the requirements of 
  paragraphs (b)(1) and (b)(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) Descriptions of test facilities and test configurations, 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 of 
  Appendix A of this subpart, 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 National Institute of Standards and Technology (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 PM sub 10 
  and PM sub 2.5, 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 PM sub 2.5 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 of Appendix A of this subpart: 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).
  
      (2) A description of the durability characteristics of such analyzers or 
  samplers (see Sec. 53.9(c)). For methods for PM sub 2.5, the warranty program must 
  {pg 38787} 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 for 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.
  
      (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 in Appendix A of this subpart 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 PM sub 2.5, 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 27711, 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 EPA 
  determines to be necessary or appropriate under Sec. 53.5(f), and such tests may 
  include special tests not described in this part. If the instrument submitted under 
  this paragraph 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 EPA. Upon completion of EPA testing, the analyzer or sampler submitted 
  under this paragraph shall be repacked by EPA for return shipment to the applicant, 
  using the same packing materials used for shipping the instrument to EPA unless 
  alternative packing is provided by the applicant. Arrangements for, and the cost 
  of, return shipment shall be the responsibility of the applicant. 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 the tests 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.
  
      (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 1 
  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 {pg 38788} 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 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 to 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, PM sub 10 sampler, or PM sub 2.5 sampler offered for sale as 
  part of a reference or equivalent method shall function within the limits of the 
  performance specifications referred to in Sec. 53.20(a), Sec. 53.30(a), Sec. 53.50, 
  or Sec. 53.60, 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, PM sub 10 sampler, or PM sub 2.5 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 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, PM sub 10 samplers, or PM sub 2.5 
  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 PM sub 2.5 or PM 
  sub 10 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, PM sub 10 sampler, or PM sub 2.5 
  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, PM sub 10 sampler, or PM sub 2.5 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 PM sub 2.5 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 
  9001-registered facility, as set forth in subpart E of this part. In the event that 
  the ISO 9001 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 9001-registered facility, the applicant shall 
  notify EPA within 30 days of the date the facility becomes other than an ISO 9001-
  registered facility, and upon such notification, EPA shall issue a preliminary 
  finding and notification of possible cancellation of the reference or equivalent 
  method designation under Sec. 53.11.
  
      (i) An applicant who has offered PM sub 2.5 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 EPA within 12 months of the date of the last such submitted Checklist 
  or Checklist update, 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 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 {pg 38789} 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.
  
      (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 EPA, 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 EPA in any hearing under this section.
  
      (5) Each party other than EPA 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 
  EPA.
  
      (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/her 
  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 therefore 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 Administrator will include written findings and conclusions and the 
  reasons or basis therefore 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 EPA Administrator prior to implementation any intended 
  modification of the {pg 38790} 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.
  
      (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).
  
      (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 1 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 part 50 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.
  
      (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 the test shall be interpreted (in such 
  cases, the 120-day period shall commence upon receipt of the additional test data).
  
      (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 commence 1 
  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 of proposed rulemaking 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. {pg 
  38791}
  
      (C) To cancel equivalent method designations based on the existing reference 
  method(s).
  
      (ii) The notice of proposed rulemaking 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)(i) 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:
  
      (A) Promulgate the proposed revision, with such modifications as may be 
  appropriate in view of comments received.
  
      (B) Where the appendix to part 50 (prior to revision) specifies a measurement 
  principle and calibration procedure, cancel reference method designations based on 
  the appendix.
  
      (C) Cancel equivalent method designations based on the existing reference 
  method(s).
  
      (D) 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.
  
      (3) 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.
  
      (4) 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.
  
      (5) 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.- Summary of Applicable Requirements for Reference and
   Equivalent Methods for Air Monitoring of Criteria Pollutants
   
   Pollutant       Ref. or Equivalent     Manual or     Applicable
                                          Automated     part 50
                                                        Appendix
   
   SO sub 2        Reference              Manual        A
                                          Manual
                   Equivalent             Automated
   CO              Reference              Automated     C
                                          Manual
                   Equivalent             Automated
   O sub 3         Reference              Automated     D
                                          Manual
                   Equivalent             Automated
   NO sub 2        Reference              Automated     F
                                          Manual
                   Equivalent             Automated
   Pb              Reference              Manual        G
                   Equivalent             Manual
   PM sub 10       Reference              Manual        J
                                          Manual
                   Equivalent             Automated
   PM sub 2.5      Reference              Manual        L
                   Equivalent Class I     Manual        L
                   Equivalent Class II    Manual        L
                   Equivalent Class III   Manual or
                                          Automated
   
   Pollutant               Applicable Subparts of part 53
                   A               B               C
   
   SO sub 2
                   check                           check
                   check           check           check
   CO              check           check
                   check                           check
                   check           check           check
   O sub 3         check           check
                   check                           check
                   check           check           check
   NO sub 2        check           check
                   check                           check
                   check           check           check
   Pb
                   check                           check
   PM sub 10       check
                   check                           check
                   check                           check
   PM sub 2.5      check
                   check                           check
                   check                           check
                   check                           check fn 1
   
   Pollutant               Applicable Subparts of part 53
                   D               E               F
   
   SO sub 2
   
   CO
   
   O sub 3
   
   NO sub 2
   
   Pb
   
   PM sub 10       check
                   check
                   check
   PM sub 2.5                      check
                                   check
                                   check           check
                                   check fn 1      check fn 1
   
   fn 1 Note: Because of the wide variety of potential devices
   possible, the specific requirements applicable to a Class III
   candidate equivalent method for PM sub 2.5 are not specified
   explicitly in this part but, instead, shall be determined on a
   case-by-case basis for each such candidiate method.
   
   
  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 E41994. 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) Copies of section 2.12 of the Quality Assurance Handbook for Air Pollution 
  {pg 38792} Measurement Systems, Volume II, Ambient Air Specific Methods, EPA/600/R-
  94/038b, are available from Department E (MD-77B), U.S. EPA, Research Triangle 
  Park, NC 27711.
  
      c. 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 SO sub 2, CO, O sub 3, and NO sub 2.
  
  53.33 Test procedure for methods for lead.
  
  53.34 Test procedure for methods for PM sub 10 and PM sub 2.5.
  
  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.-Test Specifications for PM sub 10 and PM sub 2.5 Methods
  
  Figures to Subpart C of Part 53
  
  Figure C-1.-Suggested Format for Reporting Test Results
  
  Appendix A to Subpart C of 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 SO sub 2, CO, O sub 3, and NO sub 2 methods when 
  the differences between:
  
      (i) Measurements made by a candidate manual method or by a test analyzer 
  representative of a candidate automated method.
  
      (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.
  
      (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 PM sub 10 and PM sub 2.5 methods when the 
  relationship between:
  
      (i) Measurements made by a candidate method.
  
      (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 SO sub 2, CO, O sub 3, and NO sub 2. 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 described under paragraph (d)(2) of 
  this section.
  
      (3) Methods for Pb. 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 PM sub 10. 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 PM sub 10 concentrations in the 
  specified range. The tests at the two sites may be conducted in different calendar 
  seasons, if appropriate, to provide PM sub 10 concentrations in the specified 
  ranges.
  
      (5) Methods for PM sub 2.5. Augmentation of pollutant concentrations is not 
  permitted, hence appropriate test sites must be selected to provide PM sub 2.5 
  concentrations and PM sub 2.5/PM sub 10 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 PM sub 2.5 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 must be selected such that all acceptable 
  test sample sets, as defined in Sec. 53.34(c)(3), have a PM sub 2.5/PM sub 10 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 PM sub 2.5/PM sub 10 ratio of 
  less than 0.40. At least two reference method PM sub 10 samplers shall be 
  collocated with the candidate and reference method PM sub 2.5 samplers and operated 
  simultaneously with the other samplers at each test site to measure concurrent 
  ambient concentrations of PM sub 10 to determine the PM sub 2.5/PM sub 10 ratio for 
  each sample set. The PM sub 2.5/PM sub 10 ratio for each sample set shall be the 
  average of the PM sub 2.5 concentration, as determined in Sec. 53.34(c)(1), divided 
  by the average PM sub 10 concentration, as measured by the PM sub 10 samplers. The 
  tests at the two sites may be conducted in different calendar seasons, if 
  appropriate, to provide PM sub 2.5 concentrations and PM sub 2.5/PM sub 10 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 Tables 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 SO sub 2, CO, O sub 3, and NO sub 2. 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 ensure that identical samples reach the two methods. If necessary, 
  the concentration of pollutant in the sampled ambient air may be augmented {pg 
  38793} 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 Pb, PM sub 10 and PM sub 2.5. The ambient air intake points of 
  all the candidate and reference method collocated samplers for lead, PM sub 10 or 
  PM sub 2.5 shall be positioned at the same height above the ground level, and 
  between 2 and 4 meters apart. The samplers shall be oriented in a manner that will 
  minimize spatial and wind directional effects on sample collection.
  
      (4) PM sub 10 methods employing the same sampling procedure as the reference 
  method but a different analytical method. Candidate methods for PM sub 10 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 PM sub 2.5, all submitted information must meet the 
  requirements of the ANSI/ASQC E4 Standard, 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 C 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. (1) 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).
  
      (2) For a candidate method having more than one selectable range, one range 
  must be that specified in Table B-1 of subpart B of this part and a test analyzer 
  representative of the method must pass the tests required by this subpart while 
  operated on that range. The tests may be repeated for a broader range (i.e., one 
  extending to higher concentrations) than the one specified in Table B-1 of subpart 
  B of this part, provided that the range does not extend to concentrations more than 
  two times the upper range limit specified in Table B-1 of subpart B of this part 
  and that the test analyzer has passed the tests required by subpart B of this part 
  (if applicable) for the broader range. If the tests required by this subpart are 
  conducted or passed only for the range specified in Table B-1 of subpart B of this 
  part, any equivalent method determination with respect to the method will be 
  limited to that range. If the tests are passed for both the specified range and a 
  broader range (or ranges), any such determination will include the broader range(s) 
  as well as the specified range. Appropriate test data shall be submitted for each 
  range sought to be included in such a determination.
  
      (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 
  as specified in the manual referred to in Sec. 53.4(b)(3) is permitted only every 3 
  days. Automatic adjustments which the test analyzer performs by itself are 
  permitted at any time. 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 SO sub 2, CO, O sub 3, and NO sub 2.
  
      (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 
  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 SO sub 2 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. Figure C-1 of this subpart contains a suggested format for 
  reporting the test results.
  
      (c) The results of the first set of measurements shall be interpreted as 
  follows: {pg 38794}
  
      (1) Zero failures. The candidate method passes the test for comparability.
  
      (2) Three or more failures. The candidate method fails the test for 
  comparability.
  
      (3) One or two 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 or two failures. The candidate method passes the test for 
  comparability.
  
      (ii) Three or more failures. The candidate method fails the test for 
  comparability.
  
      (4) For SO sub 2, 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 24 sequential 1-hour measurements.
  
      (f) For ozone and carbon monoxide, no more than six 1-hour measurements shall 
  be made per day. For sulfur dioxide, no more than four 1-hour measurements or one 
  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 address given 
  in Sec. 53.4(a). The audit samples are 3/4 x 8- inch glass fiber strips containing 
  known amounts of lead at the following nominal levels: 100 mu g/strip; 300 mu 
  g/strip; 750 mu g/strip. The true amount of lead, in total mu g/strip, will be 
  provided with each audit sample.
  
      (c) Filter analysis. (1) For both the reference method samples and the audit 
  samples, analyze each filter extract three 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  mu 
  g/m sup 3 for each analysis of each filter. Calculate the indicated total lead 
  amount for the audit samples in mu g/strip for each analysis of each strip. Label 
  these test results as R sub 1A, R sub 1B, R sub 1C, R sub 2A, R sub 2B, ..., Q sub 
  1A, Q sub 1B, Q sub 1C, ..., where R denotes results from the reference method 
  samples; Q denotes results from the audit samples; 1, 2, 3 indicate the filter 
  number, and A, B, C indicate 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 concentrates in  mu g/m sup 3 for each analysis of each filter. 
  Label these test results as C sub 1A, C sub 1B, C sub 2C, ..., where C denotes 
  results from the candidate method. For candidate methods which provide a direct 
  measurement of lead concentrations without a separable procedure, C sub 1A C sub 1B 
  C sub 1C, C sub 2A C sub 2B C sub 2C, etc.
  
      (d) Average lead concentration. For the reference method, calculate the average 
  lead concentration for each filter by averaging the concentrations calculated from 
  the three analyses:
  
  Equation 1
  
  {SEE ILLUSTRATION(S) IN ORIGINAL DOCUMENT}
  
  where:
  
  i is the filter number.
  
      (e) Acceptable filter pairs. 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  mu g/m sup 3. 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  mu g/m sup 3 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:
  
  Equation 2
  
  {SEE ILLUSTRATION(S) IN ORIGINAL DOCUMENT}
  
      or
  
  Equation 3
  
  {SEE ILLUSTRATION(S) IN ORIGINAL DOCUMENT}
  
  where:
  
  i indicates the filter number.
  
      (2) If any reference method precision value (P sub Ri) 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 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 (P sub Ci) exceeds 15 percent, the 
  candidate method fails the precision test.
  
      (4) The candidate method passes this test if all precision values (i.e., all P 
  sub Ri's and all P sub Ci'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:
  
  Equation 4
  
  {SEE ILLUSTRATION(S) IN ORIGINAL DOCUMENT}
  
  where:
  
  i is audit sample number. {pg 38795}
  
      (ii) Calculate the percent difference (D sub q) between the indicated lead 
  concentration for each audit sample and the true lead concentration (T sub q) as 
  follows:
  
  Equation 5
  
  {SEE ILLUSTRATION(S) IN ORIGINAL DOCUMENT}
  
      (2) If any difference value (D sub qi) 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:
  
  Equation 6
  
  {SEE ILLUSTRATION(S) IN ORIGINAL DOCUMENT}
  
  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) exceeds +/- 20 percent, the 
  candidate method passes the test for comparability.
  
      (3) If one or more of the percent differences (D) exceeds +/- 20 percent, the 
  candidate method fails the test for comparability.
  
      (i) The candidate method must pass both the precision test (paragraph (f) of 
  this section) and the comparability test (paragraph (h) of this section) to qualify 
  for designation as an equivalent method.
  
   Sec. 53.34 -- Test procedure for methods for PM sub 10 and PM sub 2.5.
  
      (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 PM sub 10 or PM sub 2.5 measurements as necessary (see paragraph 
  (c)(3) of this section), each set consisting of three reference method and three 
  candidate method measurements, all obtained simultaneously. For PM sub 2.5 
  candidate Class II equivalent methods, at least two collocated PM sub 10 reference 
  method samplers are also required to obtain PM sub 2.5/PM sub 10 ratios for each 
  sample set. Candidate PM sub 10 method measurements shall be 24-hour integrated 
  measurements; PM sub 2.5 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 PM sub 10 or PM sub 2.5 concentration in  
  mu g/m sup 3. 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 PM sub 2.5 methods is found in section 2.12 of the Quality Assurance Handbook 
  (Reference 6 of Appendix A to subpart A of this part).
  
      (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.
  
      (c) Test for comparability and precision. (1) For each of the measurement sets, 
  calculate the average PM sub 10 or PM sub 2.5 concentration obtained with the 
  reference method samplers:
  
  Equation 7
  
  {SEE ILLUSTRATION(S) IN ORIGINAL DOCUMENT}
  
  where:
  
  R denotes results from the reference method;
  
  i is the sampler number; and
  
  j is the set.
  
      (2)(i)(A) For each of the measurement sets, calculate the precision of the 
  reference method PM sub 10 or PM sub 2.5 measurements as:
  
  Equation 8
  
  {SEE ILLUSTRATION(S) IN ORIGINAL DOCUMENT}
  
      (B) If the corresponding j is below:
  
      80  mu g/m sup 3 for PM sub 10 methods.
  
      40  mu g/m sup 3 for 24-hour PM sub 2.5 at single test sites for Class I 
  candidate methods.
  
      40  mu g/m sup 3 for 24-hour PM sub 2.5 at sites having PM sub 2.5/PM sub 10 
  ratios >0.75.
  
      30  mu g/m sup 3 for 48-hour PM sub 2.5 at single test sites for Class I 
  candidate methods.
  
      30  mu g/m sup 3 for 48-hour PM sub 2.5 at sites having PM sub 2.5/PM sub 10 
  ratios >0.75.
  
      30  mu g/m sup 3 for 24-hour PM sub 2.5 at sites having PM sub 2.5/PM sub 10 
  ratios <0.40.
  
      20  mu g/m sup 3 for 48-hour PM sub 2.5 at sites having PM sub 2.5/PM sub 10 
  ratios >0.75.
  
      (ii) Otherwise, calculate the precision of the reference method PM sub 10 or PM 
  sub 2.5 measurements as:
  
  Equation 9
  
  {SEE ILLUSTRATION(S) IN ORIGINAL DOCUMENT}
  
      (3) If j 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 
  PM sub 2.5/PM sub 10 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 PM sub 
  10 or PM sub 2.5 concentration obtained with the candidate method samplers:
  
  Equation 10
  
  {SEE ILLUSTRATION(S) IN ORIGINAL DOCUMENT}
  
  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 PM sub 10 or PM sub 2.5 measurements 
  obtained with the candidate method (C sub j) against the corresponding average PM 
  sub 10 or PM sub 2.5 measurements obtained with the reference method (R sub j). For 
  each site, calculate and record the linear regression slope and intercept, and the 
  correlation coefficient.
  
      (6) If the linear regression parameters calculated under paragraph (c)(5) of 
  this section meet the values specified in Table C-4 of this subpart for all test 
  sites, the candidate method passes the test for comparability. {pg 38796}
  
  Tables to Subpart C of Part 53
  
  
   Table C -1.- Test Concentration Ranges, Number of Measurements
   Required, and Maximum Discrepancy Specification
   
   Pollutant        Concentration      Simultaneous Maximum
                    Range Parts per    Measurements Discrepancy
                    Million            Required     Specification,
                                                    Parts per
                                                    Million
                                                    1-hr
                                                    First Set
   Ozone            Low 0.06 to 0.10   5            6
                    Med 0.15 to 0.25   5            6
                    High 0.35 to 0.45  4            6
                    Total              14           18
   Carbon Monoxide  Low 7 to 11        5            6
                    Med 20 to 30       5            6
                    High 35 to 45      4            6
                    Total              14           18
   Sulfur Dioxide   Low 0.02 to 0.05
                    Med 0.10 to 0.15
                    High 0.30 to 0.50  7            8
                    Total              7            8
   Nitrogen         Low 0.02 to 0.08
   Dioxide
                    Med 0.10 to 0.20
                    High 0.25 to 0.35
                     Total
   
   Pollutant          Maximum Discrepancy Specification,
                               Parts per Million
                                 24-hr
                    Second Set   First Set    Second Set
   Ozone                                      0.02
                                              .03
                                              .04
   
   Carbon Monoxide                            1.5
                                              2.0
                                              3.0
   
   Sulfur Dioxide   3            3            0.02
                    2            3            .03
                    2            2            .04
                    7            8
   Nitrogen Dioxide 3            3            0.02
                    2            3            .03
                    2            2            .03
                    7            8
   
   
  
   Table C -2.- Sequence of Test Measurements
   
   Measurement     Concentration Range
                   First Set             Second Set
   
   1               Low                   Medium
   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, mu g/m fn 3                  0.5-4.0
   Minimum number of 24-hr measurements              5
   Maximum analytical precision, percent             5
   Maximum analytical accuracy, percent              +/- 5
   Maximum difference, percent of reference method   +/- 20
   
   
  
   Table C- 4.- Test Specifications for PM sub 10  and PM sub 2.5
   Methods
   
   Specification                   PM sub 10       PM sub 2.5
                                              Class I    Class II
   
   Acceptable concentration range  30-300     10-200     10-200
   (R sub j), mu g/m sup 3
   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 PM
   sub 10:
   R sub j < 80 mu g/m sup 3       3
   R sub j > 80 mu g/m sup 3       3
   Total                           10
   Minimum number of acceptable
   sample sets per site for PM
   sub 2.5:
   
   Single test site for Class I
   candidate equivalent methods:
   R sub j < 40 mu g/m sup 3  for             3
   24-hr or R sub j < 30 mu g/m
   sup 3  for 48-hr samples
   R sub j > 40 mu g/m sup 3  for             3
   24-hr or R sub j > 30 mu g/m
   sup 3  for 48-hr samples
   
   Sites at which the PM sub
   2.5/PM sub 10 ratio must be >
   0.75:
   R sub j < 40 mu g/m sup 3  for                        3
   24-hr or R sub j < 30 mu g/m
   sup 3  for 48-hr samples
   R sub j > 40 mu g/m sup 3  for                        3
   24-hr or R sub j > 30 mu g/m
   sup 3  for 48-hr samples
   
   Sites at which the PM sub
   2.5/PM sub 10 ratio must be <
   0.40:
   R sub j < 30 mu g/m sup 3  for                        3
   24-hr or R sub j < 20 mu g/m
   sup 3  for 48-hr samples
   R sub j > 30 mu g/m sup 3  for                        3
   24-hr or R sub j > 20 mu g/m
   sup 3  for 48-hr samples
   Total, each site                           10         10
   Precision of replicate          5 mu g/m   2 mu g/m   2 mu g/m
   reference method measurements,  sup 3  or  sup 3  or  sup 3  or
   P sub j or RP sub j             7%         5%         5%
   respectively, maximum
   Slope of regression             1 +/- 0.1  1 +/-      1 +/- 0.05
   relationship                               0.05
   Intercept of regression         0 +/- 5    0 +/- 1    0 +/- 1
   relationship, mu g/m sup 3
   Correlation of reference        "0.97      "0.97      "0.97
   method and candidate method
   measurements
   
   
   {pg 38798}
  
  Figures to Subpart C of Part 53
  
  
   Figure C-1.-Suggested Format for Reporting Test Results
   
   Candidate Method------------------------------
   
   Reference Method------------------------------
   
   Applicant-----------------------------------
   
     First Set   Second Set   Type   1 Hour   24 Hour
   
      Concentration Range     Date       Time       Concentration,
                                                    ppm
   Candidate     Reference
   
   Low ----- ppm ppm          1
   to ----
                 2
                 3
                 4
                 5
                 6
   Medium -----  1
   ppm to ----
   ppm
                 2
                 3
                 4
                 5
                 6
   High -----    1
   ppm to ----
   ppm
                 2
                 3
                 4
                 5
                 6
                 7
                 8
   
   Concentration   Difference      Table C-1       Pass or Fail
   Range                           Spec.
   Candidate
   
   Low ----- ppm
   to ----
   Medium -----
   ppm to ----
   ppm
   
   High ----- ppm
   to ---- ppm
   
                                                   Total
                                                   Failures:
   
   
   {pg 38799}
  
  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.
  
      d. 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 sub 2.5
  
  Sec.
  
  53.50 General provisions.
  
  53.51 Demonstration of compliance with design specifications and manufacturing and 
  test requirements.
  
  53.52 Leak check test.
  
  53.53 Test for flow rate accuracy, regulation, measurement accuracy, and cut-off.
  
  53.54 Test for proper sampler operation following power interruptions.
  
  53.55 Test for effect of variations in power line voltage and ambient temperature.
  
  53.56 Test for effect of variations in ambient pressure.
  
  53.57 Test for filter temperature control during sampling and post-sampling 
  periods.
  
  53.58 Operational field precision and blank test.
  
  53.59 Aerosol transport test for Class I equivalent method samplers.
  
  Tables to Subpart E of Part 53
  
  Table E-1.-Summary of Test Requirements for Reference and Class I Equivalent 
  Methods for PM sub 2.5.
  
  Table E-2.-Spectral Energy Distribution and Permitted Tolerance for Conducting 
  Radiative Tests.
  
  Figures to Subpart E of Part 53
  
  Figure E-1-Designation Testing Checklist
  
  Figure E-2-Product Manufacturing Checklist
  
  Appendix A 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 sub 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 PM sub 2.5 sampler associated with a candidate reference 
  method or Class I equivalent method meets all design and performance specifications 
  set forth in 40 CFR part 50, Appendix L, as well as additional requirements 
  specified in this subpart E. Some of these tests may also be applicable to portions 
  of a candidate Class II equivalent method sampler, as determined under subpart F of 
  this part. Some or all of these tests may also be applicable to a candidate Class 
  III equivalent method sampler, as may be determined under Sec. 53.3(a)(4) or Sec. 
  53.3(b)(3).
  
      (b) Samplers associated with candidate reference methods for PM sub 2.5 shall 
  be subject to the provisions, specifications, and test procedures prescribed in 
  Secs. 53.51 through 53.58. Samplers associated with candidate Class I equivalent 
  methods for PM sub 2.5 shall be subject to the provisions, specifications, and test 
  procedures prescribed in all sections of this subpart. Samplers associated with 
  candidate Class II equivalent methods for PM sub 2.5 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) The provisions of Sec. 53.51 pertain to test results and documentation 
  required to demonstrate compliance of a candidate method sampler with the design 
  specifications set forth in 40 CFR part 50, Appendix L. The test procedures 
  prescribed in Secs. 53.52 through 53.59 pertain to performance tests required to 
  demonstrate compliance of a candidate method sampler with the performance 
  specifications set forth in 40 CFR part 50, Appendix L, 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.
  
      (d) Test procedures prescribed in Sec. 53.59 do not apply to candidate 
  reference method samplers. These procedures apply primarily to candidate Class I 
  equivalent method samplers for PM sub 2.5 which have a sample air flow path 
  configuration upstream of the sample filter that is modified with respect to that 
  specified for the reference method sampler, as set forth in 40 CFR part 50, 
  Appendix L, Figures L-1 to L-29, such as might be necessary 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 sample filter. In addition to the other 
  test procedures in this subpart, these test procedures shall be used to further 
  test the performance of such an equivalent method sampler against the performance 
  specifications given in the procedure and summarized in Table E-1 of this subpart.
  
      (e) A 10-day operational field test of measurement precision is required under 
  Sec. 53.58 for both candidate reference and equivalent method samplers. This test 
  requires collocated operation of three 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.
  
      (f) All tests and collection of test data shall be performed 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 -- Demonstration of compliance with design specifications and 
  manufacturing and test requirements.
  
      (a) Overview. (1) The subsequent paragraphs of this section specify certain 
  documentation that must be submitted and tests that are required to demonstrate 
  that samplers associated with a designated reference or equivalent method for PM 
  sub 2.5 are properly manufactured to meet all applicable design and performance 
  specifications and have been properly tested according to all applicable test 
  requirements for such designation. Documentation is required to show that 
  instruments and components of a PM sub 2.5 sampler are manufactured in an ISO 9001-
  registered facility under a quality system that meets ISO-9001 requirements for 
  manufacturing quality control and testing.
  
      (2) 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, based on a reasonable and appropriate sample of the actual 
  operations or their documented records. Following designation of the method, 
  another checklist is required, initially {pg 38800} and annually, to provide an ISO-
  certified auditor's certification that the sampler manufacturing process is being 
  implemented under an adequate and appropriate quality system.
  
      (3) For the purposes of this section, the definitions of ISO 9001-registered 
  facility and ISO-certified auditor are found in Sec. 53.1. An exception to the 
  reliance by EPA on ISO affiliate audits is the requirement for the submission of 
  the operation or instruction manual associated with the candidate method to EPA as 
  part of the application. This manual is required under Sec. 53.4(b)(3). 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 performed 
  by EPA.
  
      (b) ISO registration of manufacturing facility. (1) The applicant must submit 
  documentation verifying that the samplers identified and sold as part of a 
  designated PM sub 2.5 reference or equivalent method will be manufactured in an ISO 
  9001-registered facility 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 registration to ISO-9001. 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 and final 
  assembled samplers all conform to the design, performance and other requirements 
  specified in this part and in 40 CFR part 50, Appendix L.
  
      (2) Phase-in period. For a period of 1 year following the effective date of 
  this subpart, a candidate reference or equivalent method for PM sub 2.5 that 
  utilizes a sampler manufactured in a facility that is not ISO 9001-registered or 
  otherwise approved by 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 facility 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 PM sub 2.5 samplers to be sold as part of 
  a reference or equivalent method and that are specified by design in 40 CFR part 
  50, Appendix L, are fabricated or manufactured exactly as specified. If the 
  manufacturer's quality records show that its quality control (QC) and quality 
  assurance (QA) system of standard process control inspections (of a set number and 
  frequency of testing that is less than 100 percent) complies with the applicable QA 
  provisions of section 4 of Reference 4 in Appendix A of this subpart and prevents 
  nonconformances, 100 percent 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. Refer also to 
  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 PM sub 2.5 impactor jet 
  diameter. The diameter of the jet of each impactor manufactured for a PM sub 2.5 
  sampler under the impactor design specifications set forth in 40 CFR part 50, 
  Appendix L, shall be verified against the tolerance specified on the drawing, using 
  standard, NIST-traceable ZZ go/no go 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. The manufacturer shall submit evidence that this 
  procedure is incorporated into the manufacturing procedure, that the test is or 
  will be routinely implemented, and that an appropriate procedure is in place for 
  the disposition of units that fail this tolerance 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 Appendix A of this subpart) 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 sensor, 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- 
  certified auditor.
  
      (f) Manufacturer's audit checklists. Manufacturers shall require an ISO-
  certified auditor to sign and date a statement indicating that the auditor is aware 
  of the appropriate manufacturing specifications contained in 40 CFR part 50, 
  Appendix L, and the test or verification requirements in this subpart. 
  Manufacturers shall also require an ISO-certified auditor 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 manufacture.
  
      (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 an ISO-
  certified auditor to complete a Product Manufacturing Checklist (Figure E-2 of this 
  subpart), 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 initial completed checklist shall be submitted with the 
  application for reference or equivalent method determination. Also, this checklist 
  (Figure E-2 of this subpart) must be completed and submitted annually to {pg 38801} 
  retain a reference or equivalent method designation for a PM sub 2.5 method.
  
      (3) Phase-in period. If the conditions of paragraph (b)(2) of this section 
  apply, a candidate reference or equivalent method for PM sub 2.5 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 (f)(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 -- Leak check test.
  
      (a) Overview. In section 7.4.6 of 40 CFR part 50, Appendix L, the sampler is 
  required to include the 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 test 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. The test conditions and performance specifications associated with this 
  test are summarized in Table E-1 of this subpart. The candidate test sampler must 
  meet all test parameters and test specifications to successfully pass this 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 mL/min 
  to 130 mL/min, 2 percent certified accuracy, NIST-traceable.
  
      (2) Flow rate measurement adaptor (40 CFR part 50, Appendix L, Figure L-30) or 
  equivalent adaptor to facilitate measurement of sampler flow rate at the top of the 
  downtube.
  
      (3) Impermeable membrane or disk, 47 mm nominal diameter.
  
      (4) Means, such as a micro-valve, of providing a simulated leak flow rate 
  through the sampler of approximately 80 mL/min under the conditions specified for 
  the leak check in the sampler's leak check procedure.
  
      (5) Teflon sample filter, as specified in section 6 of 40 CFR part 50, Appendix 
  L.
  
      (d) Calibration of test measurement instruments. Submit documentation showing 
  evidence of appropriately recent calibration, certification of calibration 
  accuracy, and NIST-traceability (if required) of all measurement instruments used 
  in the tests. The accuracy of flow rate 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 use for this test.
  
      (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 PM sub 2.5 samples, except that the sample air inlet shall be removed 
  and the 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 80 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 80 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 the impermeable membrane in a filter cassette and 
  install the cassette into the sampler. Carry out the internal leak check procedure 
  as described in the sampler's operation/instruction manual and verify that the leak 
  check acceptance criterion specified in Table E-1 of this subpart is met.
  
      (2) Replace the impermeable membrane with a Teflon filter and install the 
  cassette in the sampler. Remove the inlet from the sampler and install the flow 
  measurement adaptor on the sampler's downtube. Close the valve of the adaptor to 
  seal the flow system. Conduct the external leak check procedure as described in the 
  sampler's operation/instruction manual and verify that the leak check acceptance 
  criteria specified in Table E-1 of this subpart are met.
  
      (3) Arrange the flow control device, flow rate measurement device, and other 
  apparatus as necessary to provide a simulated leak flow rate of 80 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 80 mL/min.
  
      (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 leak check procedure properly identifies the occurrence of the 
  simulated external leak of 80 mL/min.
  
   Sec. 53.53 -- Test for flow rate accuracy, regulation, measurement accuracy, and 
  cut-off.
  
      (a) Overview. This test procedure is designed to evaluate a candidate sampler's 
  flow rate accuracy with respect to the design flow rate, flow rate regulation, flow 
  rate measurement accuracy, coefficient of variability measurement accuracy, and the 
  flow rate cut-off function. The tests for the first four parameters shall be 
  conducted over a 6-hour time period during which reference flow measurements are 
  made at intervals not to exceed 5 minutes. The flow rate cut-off test, conducted 
  separately, is intended to verify that the sampler carries out the required 
  automatic sample flow rate cut-off function properly in the event of a low-flow 
  condition. The test conditions and performance specifications associated with this 
  test are summarized in Table E-1 of this subpart. The candidate test sampler must 
  meet all test parameters and test specifications to successfully pass this test.
  
      (b) Technical definitions. (1) 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.
  
      (2) 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 
  deviates by more than the variation limits specified in Table E-1 of this subpart ( 
  +/- 10 percent from the nominal sample flow rate) for more than 60 seconds during a 
  sample collection period. The sampler is also required to properly notify the 
  operator with a flag warning indication of the out-of- specification flow rate 
  condition and if the flow rate cut-off results in an elapsed sample collection time 
  of less than 23 hours.
  
      (c) Required test equipment. (1) Flow rate meter, suitable for measuring and 
  recording the actual volumetric sample flow rate at the sampler downtube, with {pg 
  38802} a minimum range of 10 to 25 L/min, 2 percent certified, NIST-traceable 
  accuracy. Optional capability for continuous (analog) recording capability or 
  digital recording at intervals not to exceed 30 seconds is recommended. While a 
  flow meter which provides a direct indication of volumetric flow rate is preferred 
  for this test, an alternative certified flow measurement device may be used as long 
  as appropriate volumetric flow rate corrections are made based on measurements of 
  actual ambient temperature and pressure conditions.
  
      (2) Ambient air temperature sensor, with a resolution of 0.1 deg C and 
  certified to be accurate to within 0.5 deg C (if needed). If the certified flow 
  meter does not provide direct volumetric flow rate readings, ambient air 
  temperature measurements must be made using continuous (analog) recording 
  capability or digital recording at intervals not to exceed 5 minutes.
  
      (3) Barometer, range 600 mm Hg to 800 mm Hg, certified accurate to 2 mm Hg (if 
  needed). If the certified flow meter does not provide direct volumetric flow rate 
  readings, ambient pressure measurements must be made using continuous (analog) 
  recording capability or digital recording at intervals not to exceed 5 minutes.
  
      (4) Flow measurement adaptor (40 CFR part 50, Appendix L, Figure L-30) or 
  equivalent adaptor to facilitate measurement of sample flow rate at the sampler 
  downtube.
  
      (5) Valve or other means to restrict or reduce the sample flow rate to a value 
  at least 10 percent below the design flow rate (16.67 L/min). If appropriate, the 
  valve of the flow measurement adaptor may be used for this purpose.
  
      (6) 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.
  
      (7) Teflon sample filter, as specified in section 6 of 40 CFR part 50, Appendix 
  L (if required).
  
      (d) Calibration of test measurement instruments. Submit documentation showing 
  evidence of appropriately recent calibration, certification of calibration 
  accuracy, and NIST-traceability (if required) of all measurement instruments used 
  in the tests. The accuracy of flow-rate meters shall be verified at the highest and 
  lowest pressures and temperatures used in the tests and shall be checked at zero 
  and at least one flow rate within +/- 3 percent of 16.7 L/min within 7 days prior 
  to use for this test. 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) Setup of the sampler shall be as required in this paragraph 
  (e) and otherwise 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 PM sub 2.5 samples. A sample filter and 
  (or) the device for creating an additional 55 mm Hg pressure drop shall be 
  installed for the duration of these tests. The sampler's ambient temperature, 
  ambient pressure, and flow rate measurement systems shall all be calibrated per the 
  sampler's operation or instruction manual within 7 days prior to this test.
  
      (2) The inlet of the candidate sampler shall be removed and the flow 
  measurement adaptor installed on the sampler's downtube. A leak check as described 
  in the sampler's operation or instruction manual shall be conducted and must be 
  properly passed before other tests are carried out.
  
      (3) The inlet of the flow measurement adaptor shall be connected to the outlet 
  of the flow rate meter.
  
      (4) For the flow rate cut-off test, the valve or means for reducing sampler 
  flow rate shall be installed between the flow measurement adaptor and the downtube 
  or in another location within the sampler such that the sampler flow rate can be 
  manually restricted during the test.
  
      (f) Procedure. (1) Set up the sampler as specified in paragraph (e) of this 
  section and otherwise 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 6-hour sample collection period at a convenient time.
  
      (2) During the 6-hour operational flow rate portion of the test, measure and 
  record the sample flow rate with the flow rate meter at intervals not to exceed 5 
  minutes. If ambient temperature and pressure corrections are necessary to calculate 
  volumetric flow rate, ambient temperature and pressure shall be measured at the 
  same frequency as that of the certified flow rate measurements. Note and record the 
  actual start and stop times for the 6-hour flow rate test period.
  
      (3) Following completion of the 6-hour flow rate test period, install the flow 
  rate reduction device and change the sampler flow rate recording frequency to 
  intervals of not more than 30 seconds. Reset the sampler to start a new sample 
  collection period. Manually restrict the sampler flow rate such that the sampler 
  flow rate is decreased slowly over several minutes to a flow rate slightly less 
  than the flow rate cut-off value (15.0 L/min). Maintain this flow rate for at least 
  2.0 minutes or until the sampler stops the sample flow automatically. Manually 
  terminate the sample period, if the sampler has not terminated it automatically.
  
      (g) Test results. At the completion of the test, validate the test conditions 
  and determine the test results as follows:
  
      (1) Mean sample flow rate. (i) From the certified measurements (Q sub ref) of 
  the test sampler flow rate obtained by use of the flow rate meter, tabulate each 
  flow rate measurement in units of L/min. If ambient temperature and pressure 
  corrections are necessary to calculate volumetric flow rate, each measured flow 
  rate shall be corrected using its corresponding temperature and pressure 
  measurement values. Calculate the mean flow rate for the sample period (Q sub 
  ref,ave) as follows:
  
  Equation 1
  
  {SEE ILLUSTRATION(S) IN ORIGINAL DOCUMENT}
  
  where:
  
  n equals the number of discrete certified flow rate measurements over the 6-hour 
  test period.
  
      (ii)(A) Calculate the percent difference between this mean flow rate value and 
  the design value of 16.67 L/min, as follows:
  
  Equation 2
  
  {SEE ILLUSTRATION(S) IN ORIGINAL DOCUMENT}
  
      (B) To successfully pass the mean flow rate test, the percent difference 
  calculated in Equation 2 of this paragraph (g)(1)(ii) must be within +/- 5 percent.
  
      (2) Sample flow rate regulation. (i) From the certified measurements of the 
  test sampler flow rate, calculate the sample coefficient of variation (CV) of the 
  discrete measurements as follows:
  
  Equation 3
  
  {SEE ILLUSTRATION(S) IN ORIGINAL DOCUMENT}
  
      (ii) To successfully pass the flow rate regulation test, the calculated 
  coefficient of variation for the certified flow rates must not exceed 2 percent. 
  {pg 38803}
  
      (3) Flow rate measurement accuracy. (i) Using the mean volumetric flow rate 
  reported by the candidate test sampler at the completion of the 6- hour test period 
  (Q sub ind,ave), determine the accuracy of the reported mean flow rate as:
  
  Equation 4
  
  {SEE ILLUSTRATION(S) IN ORIGINAL DOCUMENT}
  
      (ii) To successfully pass the flow rate measurement accuracy test, the percent 
  difference calculated in Equation 4 of this paragraph (g)(3) shall not exceed 2 
  percent.
  
      (4) Flow rate coefficient of variation measurement accuracy. (i) Using the flow 
  rate coefficient of variation indicated by the candidate test sampler at the 
  completion of the 6-hour test (%CV sub ind), determine the accuracy of this 
  reported coefficient of variation as:
  
  Equation 5
  
  {SEE ILLUSTRATION(S) IN ORIGINAL DOCUMENT}
  
      (ii) To successfully pass the flow rate CV measurement accuracy test, the 
  absolute difference in values calculated in Equation 5 of this paragraph (g)(4) 
  must not exceed 0.3 (CV%).
  
      (5) Flow rate cut-off. (i) Inspect the measurements of the sample flow rate 
  during the flow rate cut-off test and determine the time at which the sample flow 
  rate decreased to a value less than the cut-off value specified in Table E-1 of 
  this subpart. To pass this test, the sampler must have automatically stopped the 
  sample flow at least 30 seconds but not more than 90 seconds after the time at 
  which the sampler flow rate was determined to have decreased to a value less than 
  the cut-off value.
  
      (ii) At the completion of the flow rate cut-off test, download the archived 
  data from the test sampler and verify that the sampler's required Flow-out-of-spec 
  and Incorrect sample period flag indicators are properly set.
  
   Sec. 53.54 -- Test for proper sampler operation following power interruptions.
  
      (a) Overview. (1) This test procedure is designed to test certain performance 
  parameters of the candidate sampler during a test period in which power 
  interruptions of various duration occur. The performance parameters tested are:
  
      (i) Proper flow rate performance of the sampler.
  
      (ii) Accuracy of the sampler's average flow rate, CV, and sample volume 
  measurements.
  
      (iii) Accuracy of the sampler's reported elapsed sampling time.
  
      (iv) Accuracy of the reported time and duration of power interruptions.
  
      (2) This test shall be conducted during operation of the test sampler over a 
  continuous 6-hour test period during which the sampler's flow rate shall be 
  measured and recorded at intervals not to exceed 5 minutes. The performance 
  parameters tested under this procedure, the corresponding minimum performance 
  specifications, and the applicable test conditions are summarized in Table E-1 of 
  this subpart. Each performance parameter tested, as described or determined in the 
  test procedure, must meet or exceed the associated performance specification to 
  successfully pass this test.
  
      (b) Required test equipment. (1) Flow rate meter, suitable for measuring and 
  recording the actual volumetric sample flow rate at the sampler downtube, with a 
  minimum range of 10 to 25 L/min, 2 percent certified, NIST-traceable accuracy. 
  Optional capability for continuous (analog) recording capability or digital 
  recording at intervals not to exceed 5 minutes is recommended. While a flow meter 
  which provides a direct indication of volumetric flow rate is preferred for this 
  test, an alternative certified flow measurement device may be used as long as 
  appropriate volumetric flow rate corrections are made based on measurements of 
  actual ambient temperature and pressure conditions.
  
      (2) Ambient air temperature sensor (if needed for volumetric corrections to 
  flow rate measurements), with a resolution of 0.1 deg C, certified accurate to 
  within 0.5 deg C, and continuous (analog) recording capability or digital recording 
  at intervals not to exceed 5 minutes.
  
      (3) Barometer (if needed for volumetric corrections to flow rate measurements), 
  range 600 mm Hg to 800 mm Hg, certified accurate to 2 mm Hg, with continuous 
  (analog) recording capability or digital recording at intervals not to exceed 5 
  minutes.
  
      (4) Flow measurement adaptor (40 CFR part 50, Appendix L, Figure L-30) or 
  equivalent adaptor to facilitate measurement of sample flow rate at the sampler 
  downtube.
  
      (5) 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.
  
      (6) Teflon sample filter, as specified in section 6 of 40 CFR part 50, Appendix 
  L (if required).
  
      (7) Time measurement system, accurate to within 10 seconds per day.
  
      (c) Calibration of test measurement instruments. Submit documentation showing 
  evidence of appropriately recent calibration, certification of calibration 
  accuracy, and NIST- traceability (if required) of all measurement instruments used 
  in the tests. The accuracy of flow rate meters shall be verified at the highest and 
  lowest pressures and temperatures used in the tests and shall be checked at zero 
  and at least one flow rate within +/- 3 percent of 16.7 L/min within 7 days prior 
  to use for this test. 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.
  
      (d) Test setup. (1) Setup of the sampler shall be performed as required in this 
  paragraph (d) and otherwise 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 PM sub 2.5 samples. A sample 
  filter and (or) the device for creating an additional 55 mm Hg pressure drop shall 
  be installed for the duration of these tests. The sampler's ambient temperature, 
  ambient pressure, and flow measurement systems shall all be calibrated per the 
  sampler's operating manual within 7 days prior to this test.
  
      (2) The inlet of the candidate sampler shall be removed and the flow 
  measurement adaptor installed on the sample downtube. A leak check as described in 
  the sampler's operation or instruction manual shall be conducted and must be 
  properly passed before other tests are carried out.
  
      (3) The inlet of the flow measurement adaptor shall be connected to the outlet 
  of the flow rate meter.
  
      (e) Procedure. (1) Set up the sampler as specified in paragraph (d) of this 
  section and otherwise 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 6-hour sample collection period at a convenient time.
  
      (2) During the entire 6-hour operational flow rate portion of the test, measure 
  and record the sample flow rate with the flow rate meter at intervals not to exceed 
  5 minutes. If ambient temperature and pressure corrections are necessary to 
  calculate volumetric flow rate, ambient temperature and pressure shall be measured 
  at the same frequency as that of the certified flow rate measurements. Note and 
  record the actual start and stop times for the 6-hour flow rate test period.
  
      (3) During the 6-hour test period, interrupt the AC line electrical power to 
  {pg 38804} the sampler 5 times, with durations of 20 seconds, 40 seconds, 2 
  minutes, 7 minutes, and 20 minutes (respectively), with not less than 10 minutes of 
  normal electrical power supplied between each power interruption. Record the hour 
  and minute and duration of each power interruption.
  
      (4) At the end of the test, terminate the sample period (if not automatically 
  terminated by the sampler) and download all archived instrument data from the test 
  sampler.
  
      (f) Test results. At the completion of the sampling period, validate the test 
  conditions and determine the test results as follows:
  
      (1) Mean sample flow rate. (i) From the certified measurements (Q sub ref) of 
  the test sampler flow rate, tabulate each flow rate measurement in units of L/min. 
  If ambient temperature and pressure corrections are necessary to calculate 
  volumetric flow rate, each measured flow rate shall be corrected using its 
  corresponding temperature and pressure measurement values. Calculate the mean flow 
  rate for the sample period (Q sub ref,ave) as follows:
  
  Equation 6
  
  {SEE ILLUSTRATION(S) IN ORIGINAL DOCUMENT}
  
  where:
  
  n equals the number of discrete certified flow rate measurements over the 6-hour 
  test period, excluding flow rate values obtained during periods of power 
  interruption.
  
      (ii)(A) Calculate the percent difference between this mean flow rate value and 
  the design value of 16.67 L/min, as follows:
  
  Equation 7
  
  {SEE ILLUSTRATION(S) IN ORIGINAL DOCUMENT}
  
      (B) To successfully pass this test, the percent difference calculated in 
  Equation 7 of this paragraph (f)(1)(ii) must be within +/- 5 percent.
  
      (2) Sample flow rate regulation. (i) From the certified measurements of the 
  test sampler flow rate, calculate the sample coefficient of variation of the 
  discrete measurements as follows:
  
  Equation 8
  
  {SEE ILLUSTRATION(S) IN ORIGINAL DOCUMENT}
  
      (ii) To successfully pass this test, the calculated coefficient of variation 
  for the certified flow rates must not exceed 2 percent.
  
      (3) Flow rate measurement accuracy. (i) Using the mean volumetric flow rate 
  reported by the candidate test sampler at the completion of the 6-hour test (Q sub 
  ind,ave), determine the accuracy of the reported mean flow rate as:
  
  Equation 9
  
  {SEE ILLUSTRATION(S) IN ORIGINAL DOCUMENT}
  
      (ii) To successfully pass this test, the percent difference calculated in 
  Equation 9 of this paragraph (f)(3) shall not exceed 2 percent.
  
      (4) Flow rate CV measurement accuracy. (i) Using the flow rate coefficient of 
  variation indicated by the candidate test sampler at the completion of the 6-hour 
  test (%CV sub ind), determine the accuracy of the reported coefficient of variation 
  as:
  
  Equation 10
  
  {SEE ILLUSTRATION(S) IN ORIGINAL DOCUMENT}
  
      (ii) To successfully pass this test, the absolute difference in values 
  calculated in Equation 10 of this paragraph (f)(4) must not exceed 0.3 (CV%).
  
      (5) Verify that the sampler properly provided a record and visual display of 
  the correct year, month, day-of-month, hour, and minute with an accuracy of +/- 2 
  minutes, of the start of each power interruption of duration greater than 60 
  seconds.
  
      (6) Calculate the actual elapsed sample time, excluding the periods of 
  electrical power interruption. Verify that the elapsed sample time reported by the 
  sampler is accurate to within +/- 20 seconds for the 6-hour test run.
  
      (7) Calculate the sample volume as Q sub ref,ave the sample time, excluding 
  periods of power interruption. Verify that the sample volume reported by the 
  sampler is within 2 percent of the calculated sample volume to successfully pass 
  this test.
  
      (8) Inspect the downloaded instrument data from the test sampler and verify 
  that all data are consistent with normal operation of the sampler.
  
   Sec. 53.55 -- Test for effect of variations in power line voltage and ambient 
  temperature.
  
      (a) Overview. (1) This test procedure is a combined procedure to test various 
  performance parameters under variations in power line voltage and ambient 
  temperature. Tests shall be conducted in a temperature controlled environment over 
  four 6-hour time periods during which reference temperature and flow rate 
  measurements shall be made at intervals not to exceed 5 minutes. Specific 
  parameters to be evaluated at line voltages of 105 and 125 volts and temperatures 
  of -20 deg C and +40 deg C are as follows:
  
      (i) Sample flow rate.
  
      (ii) Flow rate regulation.
  
      (iii) Flow rate measurement accuracy.
  
      (iv) Coefficient of variability measurement accuracy.
  
      (v) Ambient air temperature measurement accuracy.
  
      (vi) Proper operation of the sampler when exposed to power line voltage and 
  ambient temperature extremes.
  
      (2) The performance parameters tested under this procedure, the corresponding 
  minimum performance specifications, and the applicable test conditions are 
  summarized in Table E-1 of this subpart. Each performance parameter tested, as 
  described or determined in the test procedure, must meet or exceed the associated 
  performance specification given. The candidate sampler must meet all specifications 
  for the associated PM sub 2.5 method to pass this test procedure.
  
      (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 
  temperatures at -20 deg C and +40 deg C as required for the test with an accuracy 
  of +/- 2 deg C. The test environment(s) must be capable of maintaining these 
  temperatures 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.
  
      (2) Variable voltage AC power transformer, range 100 Vac to 130 Vac, with 
  sufficient current capacity to operate the test sampler continuously under the test 
  conditions.
  
      (3) Flow rate meter, suitable for measuring and recording the actual volumetric 
  sample flow rate at the sampler downtube, with a minimum range of 10 to 25 actual 
  L/min, 2 percent certified, NIST-traceable accuracy. Optional capability for 
  continuous (analog) recording capability or digital recording at intervals not to 
  exceed 5 minutes is recommended. While a flow {pg 38805} meter which provides a 
  direct indication of volumetric flow rate is preferred for this test, an 
  alternative certified flow measurement device may be used as long as appropriate 
  volumetric flow rate corrections are made based on measurements of actual ambient 
  temperature and pressure conditions.
  
      (4) Ambient air temperature recorder, range -30 deg C to +50 deg C, with a 
  resolution of 0.1 deg C and certified accurate to within 0.5 deg C. Ambient air 
  temperature measurements must be made using continuous (analog) recording 
  capability or digital recording at intervals not to exceed 5 minutes.
  
      (5) Barometer, range 600 mm Hg to 800 mm Hg, certified accurate to 2 mm Hg. If 
  the certified flow rate meter does not provide direct volumetric flow rate 
  readings, ambient pressure measurements must be made using continuous (analog) 
  recording capability or digital recording at intervals not to exceed 5 minutes.
  
      (6) Flow measurement adaptor (40 CFR part 50, Appendix L, Figure L-30) or 
  equivalent adaptor to facilitate measurement of sampler flow rate at the sampler 
  downtube.
  
      (7) 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.
  
      (8) AC RMS voltmeter, accurate to 1.0 volt.
  
      (9) Teflon sample filter, as specified in section 6 of 40 CFR part 50, Appendix 
  L (if required).
  
      (d) Calibration of test measurement instruments. Submit documentation showing 
  evidence of appropriately recent calibration, certification of calibration 
  accuracy, and NIST-traceability (if required) of all measurement instruments used 
  in the tests. The accuracy of flow rate meters shall be verified at the highest and 
  lowest pressures and temperatures used in the tests and shall be checked at zero 
  and at least one flow rate within +/- 3 percent of 16.7 L/min within 7 days prior 
  to use for this test. 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) Setup of the sampler shall be performed as required in this 
  paragraph (e) and otherwise 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 the temperature-controlled chamber in its normal configuration for 
  collecting PM sub 2.5 samples. A sample filter and (or) the device for creating an 
  additional 55 mm Hg pressure drop shall be installed for the duration of these 
  tests. The sampler's ambient temperature, ambient pressure, and flow measurement 
  systems shall all be calibrated per the sampler's operating manual within 7 days 
  prior to this test.
  
      (2) The inlet of the candidate sampler shall be removed and the flow 
  measurement adaptor installed on the sampler's downtube. A leak check as described 
  in the sampler's operation or instruction manual shall be conducted and must be 
  properly passed before other tests are carried out.
  
      (3) The inlet of the flow measurement adaptor shall be connected to the outlet 
  of the flow rate meter.
  
      (4) 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 vicinity of 
  the candidate sampler without being unduly affected by the chamber's air 
  temperature control system.
  
      (f) Procedure. (1) Set up the sampler as specified in paragraph (e) of this 
  section and otherwise prepare the sampler for normal sample collection operation as 
  directed in the sampler's operation or instruction manual.
  
      (2) The test shall consist of four test runs, one at each of the following 
  conditions of chamber temperature and electrical power line voltage (respectively):
  
      (i) -20 deg C +/- 2 deg C and 105 +/- 1 Vac.
  
      (ii) -20 deg C +/- 2 deg C and 125 +/- 1 Vac.
  
      (iii) +40 deg C +/- 2 deg C and 105 +/- 1 Vac.
  
      (iv) +40 deg C +/- 2 deg C and 125 +/- 1 Vac.
  
      (3) For each of the four test runs, set the selected chamber temperature and 
  power line voltage for the test run. Upon achieving each temperature setpoint in 
  the chamber, the candidate sampler and flow meter shall be thermally equilibrated 
  for a period of at least 2 hours prior to the test run. Following the thermal 
  conditioning time, set the sampler to automatically start a 6-hour sample 
  collection period at a convenient time.
  
      (4) During each 6- hour test period:
  
      (i) Measure and record the sample flow rate with the flow rate meter at 
  intervals not to exceed 5 minutes. If ambient temperature and pressure corrections 
  are necessary to calculate volumetric flow rate, ambient temperature and pressure 
  shall be measured at the same frequency as that of the certified flow rate 
  measurements. Note and record the actual start and stop times for the 6-hour flow 
  rate test period.
  
      (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 at intervals not 
  to exceed 5 minutes.
  
      (iii) Measure the power line voltage to the sampler at intervals not greater 
  than 1 hour.
  
      (5) At the end of each test run, terminate the sample period (if not 
  automatically terminated by the sampler) and download all archived instrument data 
  from the test sampler.
  
      (g) Test results. For each of the four test runs, examine the chamber 
  temperature measurements and the power line voltage measurements. Verify that the 
  temperature and line voltage met the requirements specified in paragraph (f) of 
  this section at all times during the test run. If not, the test run is not valid 
  and must be repeated. Determine the test results as follows:
  
      (1) Mean sample flow rate. (i) From the certified measurements (Q sub ref) of 
  the test sampler flow rate, tabulate each flow rate measurement in units of L/min. 
  If ambient temperature and pressure corrections are necessary to calculate 
  volumetric flow rate, each measured flow rate shall be corrected using its 
  corresponding temperature and pressure measurement values. Calculate the mean flow 
  rate for each sample period (Q sub ref,ave) as follows:
  
  Equation 11
  
  {SEE ILLUSTRATION(S) IN ORIGINAL DOCUMENT}
  
  where:
  
  n equals the number of discrete certified flow rate measurements over each 6-hour 
  test period.
  
      (ii)(A) Calculate the percent difference between this mean flow rate value and 
  the design value of 16.67 L/min, as follows:
  
  Equation 12
  
  {SEE ILLUSTRATION(S) IN ORIGINAL DOCUMENT}
  
      (B) To successfully pass this test, the percent difference calculated in 
  Equation 12 of this paragraph (g)(1)(ii) must be within +/- 5 percent for each test 
  run.
  
      (2) Sample flow rate regulation. (i) From the certified measurements of the 
  test sampler flow rate, calculate the sample coefficient of variation of the 
  discrete measurements as follows: {pg 38806}
  
  Equation 13
  
  {SEE ILLUSTRATION(S) IN ORIGINAL DOCUMENT}
  
      (ii) To successfully pass this test, the calculated coefficient of variation 
  for the certified flow rates must not exceed 2 percent.
  
      (3) Flow rate measurement accuracy. (i) Using the mean volumetric flow rate 
  reported by the candidate test sampler at the completion of each 6-hour test (Q sub 
  ind,ave), determine the accuracy of the reported mean flow rate as:
  
  Equation 14
  
  {SEE ILLUSTRATION(S) IN ORIGINAL DOCUMENT}
  
      (ii) To successfully pass this test, the percent difference calculated in 
  Equation 14 of this paragraph (g)(3) shall not exceed 2 percent for each test run.
  
      (4) Flow rate coefficient of variation measurement accuracy. (i) Using the flow 
  rate coefficient of variation indicated by the candidate test sampler (%CV sub 
  ind), determine the accuracy of the reported coefficient of variation as:
  
  Equation 15
  
  {SEE ILLUSTRATION(S) IN ORIGINAL DOCUMENT}
  
      (ii) To successfully pass this test, the absolute difference calculated in 
  Equation 15 of this paragraph (g)(4) must not exceed 0.3 (CV%) for each test run.
  
      (5) Ambient temperature measurement accuracy. (i) Calculate the absolute value 
  of the difference between the mean ambient air temperature indicated by the test 
  sampler and the mean ambient (chamber) air temperature measured with the ambient 
  air temperature recorder as:
  
  Equation 16
  
  {SEE ILLUSTRATION(S) IN ORIGINAL DOCUMENT}
  
  where:
  
  T sub ind,ave mean ambient air temperature indicated by the test sampler, deg C; 
  and
  
  T sub ref,ave mean ambient air temperature measured by the reference temperature 
  instrument, deg C.
  
      (ii) The calculated temperature difference must be less than 2 deg C for each 
  test run.
  
      (6) Sampler functionality. To pass the sampler functionality test, the 
  following two conditions must both be met for each test run:
  
      (i) The sampler must not shutdown during any portion of the 6-hour test.
  
      (ii) An inspection of the downloaded data from the test sampler verifies that 
  all the data are consistent with normal operation of the sampler.
  
   Sec. 53.56 -- Test for effect of variations in ambient pressure.
  
      (a) Overview. (1) This test procedure is designed to test various sampler 
  performance parameters under variations in ambient (barometric) pressure. Tests 
  shall be conducted in a pressure-controlled environment over two 6- hour time 
  periods during which reference pressure and flow rate measurements shall be made at 
  intervals not to exceed 5 minutes. Specific parameters to be evaluated at operating 
  pressures of 600 and 800 mm Hg are as follows:
  
      (i) Sample flow rate.
  
      (ii) Flow rate regulation.
  
      (iii) Flow rate measurement accuracy.
  
      (iv) Coefficient of variability measurement accuracy.
  
      (v) Ambient pressure measurement accuracy.
  
      (vi) Proper operation of the sampler when exposed to ambient pressure extremes.
  
      (2) The performance parameters tested under this procedure, the corresponding 
  minimum performance specifications, and the applicable test conditions are 
  summarized in Table E-1 of this subpart. Each performance parameter tested, as 
  described or determined in the test procedure, must meet or exceed the associated 
  performance specification given. The candidate sampler must meet all specifications 
  for the associated PM sub 2.5 method to pass this test procedure.
  
      (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) Hypobaric chamber or other pressure-controlled 
  environment or environments, capable of obtaining and maintaining pressures at 600 
  mm Hg and 800 mm Hg required for the test with an accuracy of 5 mm Hg. Henceforth, 
  where the test procedures specify a test or environmental chamber, an alternative 
  pressure-controlled environmental area or areas may be substituted, provided the 
  test pressure requirements are met. Means for simulating ambient pressure using a 
  closed-loop sample air system may also be approved for this test; such a proposed 
  method for simulating the test pressure conditions may be described and submitted 
  to EPA at the address given in Sec. 53.4(a) prior to conducting the test for a 
  specific individual determination of acceptability.
  
      (2) Flow rate meter, suitable for measuring and recording the actual volumetric 
  sampler flow rate at the sampler downtube, with a minimum range of 10 to 25 L/min, 
  2 percent certified, NIST-traceable accuracy. Optional capability for continuous 
  (analog) recording capability or digital recording at intervals not to exceed 5 
  minutes is recommended. While a flow meter which provides a direct indication of 
  volumetric flow rate is preferred for this test, an alternative certified flow 
  measurement device may be used as long as appropriate volumetric flow rate 
  corrections are made based on measurements of actual ambient temperature and 
  pressure conditions.
  
      (3) Ambient air temperature recorder (if needed for volumetric corrections to 
  flow rate measurements) with a range -30 deg C to +50 deg C, certified accurate to 
  within 0.5 deg C. If the certified flow meter does not provide direct volumetric 
  flow rate readings, ambient temperature measurements must be made using continuous 
  (analog) recording capability or digital recording at intervals not to exceed 5 
  minutes.
  
      (4) Barometer, range 600 mm Hg to 800 mm Hg, certified accurate to 2 mm Hg. 
  Ambient air pressure measurements must be made using continuous (analog) recording 
  capability or digital recording at intervals not to exceed 5 minutes.
  
      (5) Flow measurement adaptor (40 CFR part 50, Appendix L, Figure L-30) or 
  equivalent adaptor to facilitate measurement of sampler flow rate at the sampler 
  downtube.
  
      (6) 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.
  
      (7) Teflon sample filter, as specified in section 6 of 40 CFR part 50, Appendix 
  L (if required).
  
      (d) Calibration of test measurement instruments. Submit documentation showing 
  evidence of appropriately recent calibration, certification of calibration 
  accuracy, and NIST-traceability (if required) of all measurement instruments used 
  in the tests. The accuracy of flow rate meters shall be verified at the highest and 
  lowest pressures and temperatures used in the tests and shall be checked at zero 
  and at least one flow rate within +/- 3 percent of 16.7 L/min within 7 days prior 
  to use for this test. Where an instrument's measurements are to be {pg 38807} 
  recorded with an analog recording device, the accuracy of the entire instrument-
  recorder system shall be calibrated or verified.
  
      (e) Test setup. (1) Setup of the sampler shall be performed as required in this 
  paragraph (e) and otherwise 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 the pressure-controlled chamber in its normal configuration for 
  collecting PM sub 2.5 samples. A sample filter and (or) the device for creating an 
  additional 55 mm Hg pressure drop shall be installed for the duration of these 
  tests. The sampler's ambient temperature, ambient pressure, and flow measurement 
  systems shall all be calibrated per the sampler's operating manual within 7 days 
  prior to this test.
  
      (2) The inlet of the candidate sampler shall be removed and the flow 
  measurement adaptor installed on the sampler's downtube. A leak check as described 
  in the sampler's operation or instruction manual shall be conducted and must be 
  properly passed before other tests are carried out.
  
      (3) The inlet of the flow measurement adaptor shall be connected to the outlet 
  of the flow rate meter.
  
      (4) The barometer shall be installed in the test chamber such that it will 
  accurately measure the air pressure to which the candidate sampler is subjected.
  
      (f) Procedure. (1) Set up the sampler as specified in paragraph (e) of this 
  section and otherwise prepare the sampler for normal sample collection operation as 
  directed in the sampler's operation or instruction manual.
  
      (2) The test shall consist of two test runs, one at each of the following 
  conditions of chamber pressure:
  
      (i) 600 mm Hg.
  
      (ii) 800 mm Hg.
  
      (3) For each of the two test runs, set the selected chamber pressure for the 
  test run. Upon achieving each pressure setpoint in the chamber, the candidate 
  sampler shall be pressure-equilibrated for a period of at least 30 minutes prior to 
  the test run. Following the conditioning time, set the sampler to automatically 
  start a 6- hour sample collection period at a convenient time.
  
      (4) During each 6-hour test period:
  
      (i) Measure and record the sample flow rate with the flow rate meter at 
  intervals not to exceed 5 minutes. If ambient temperature and pressure corrections 
  are necessary to calculate volumetric flow rate, ambient temperature and pressure 
  shall be measured at the same frequency as that of the certified flow rate 
  measurements. Note and record the actual start and stop times for the 6-hour flow 
  rate test period.
  
      (ii) Determine and record the ambient (chamber) pressure indicated by the 
  sampler and the corresponding ambient (chamber) pressure measured by the barometer 
  specified in paragraph (c)(4) of this section at intervals not to exceed 5 minutes.
  
      (5) At the end of each test period, terminate the sample period (if not 
  automatically terminated by the sampler) and download all archived instrument data 
  from the test sampler.
  
      (g) Test results. For each of the two test runs, examine the chamber pressure 
  measurements. Verify that the pressure met the requirements specified in paragraph 
  (f) of this section at all times during the test. If not, the test run is not valid 
  and must be repeated. Determine the test results as follows:
  
      (1) Mean sample flow rate. (i) From the certified measurements (Q sub ref) of 
  the test sampler flow rate, tabulate each flow rate measurement in units of L/min. 
  If ambient temperature and pressure corrections are necessary to calculate 
  volumetric flow rate, each measured flow rate shall be corrected using its 
  corresponding temperature and pressure measurement values. Calculate the mean flow 
  rate for the sample period (Q sub ref,ave) as follows:
  
  Equation 17
  
  {SEE ILLUSTRATION(S) IN ORIGINAL DOCUMENT}
  
  where:
  
  n equals the number of discrete certified flow measurements over the 6-hour test 
  period.
  
      (ii)(A) Calculate the percent difference between this mean flow rate value and 
  the design value of 16.67 L/min, as follows:
  
  Equation 18
  
  {SEE ILLUSTRATION(S) IN ORIGINAL DOCUMENT}
  
      (B) To successfully pass this test, the percent difference calculated in 
  Equation 18 of this paragraph (g)(1) must be within +/- 5 percent for each test 
  run.
  
      (2) Sample flow rate regulation. (i) From the certified measurements of the 
  test sampler flow rate, calculate the sample coefficient of variation of the 
  discrete measurements as follows:
  
  Equation 19
  
  {SEE ILLUSTRATION(S) IN ORIGINAL DOCUMENT}
  
      (ii) To successfully pass this test, the calculated coefficient of variation 
  for the certified flow rates must not exceed 2 percent.
  
      (3) Flow rate measurement accuracy. (i) Using the mean volumetric flow rate 
  reported by the candidate test sampler at the completion of each 6-hour test (Q sub 
  ind,ave), determine the accuracy of the reported mean flow rate as:
  
  Equation 20
  
  {SEE ILLUSTRATION(S) IN ORIGINAL DOCUMENT}
  
      (ii) To successfully pass this test, the percent difference calculated in 
  Equation 20 of this paragraph (g)(3) shall not exceed 2 percent for each test run.
  
      (4) Flow rate CV measurement accuracy. (i) Using the flow rate coefficient of 
  variation indicated by the candidate test sampler at the completion of the 6-hour 
  test (%CV sub ind), determine the accuracy of the reported coefficient of variation 
  as:
  
  Equation 21
  
  {SEE ILLUSTRATION(S) IN ORIGINAL DOCUMENT}
  
      (ii) To successfully pass this test, the absolute difference in values 
  calculated in Equation 21 of this paragraph (g)(4) must not exceed 0.3 (CV%) for 
  each test run.
  
      (5) Ambient pressure measurement accuracy. (i) Calculate the absolute 
  difference between the mean ambient air pressure indicated by the test sampler and 
  the ambient (chamber) air pressure measured with the reference barometer as:
  
  Equation 22
  
  {SEE ILLUSTRATION(S) IN ORIGINAL DOCUMENT}
  
  where:
  
  P sub ind,ave mean ambient pressure indicated by the test sampler, mm Hg; and
  
  P sub ref,ave mean barometric pressure measured by the reference barometer, mm Hg.
  
      (ii) The calculated pressure difference must be less than 10 mm Hg for each 
  test run to pass the test.
  
      (6) Sampler functionality. To pass the sampler functionality test, the 
  following two conditions must both be met for each test run:
  
      (i) The sampler must not shut down during any part of the 6-hour tests; and
  
      (ii) An inspection of the downloaded data from the test sampler verifies that 
  all the data are consistent with normal operation of the sampler.
  
   Sec. 53.57 -- Test for filter temperature control during sampling and post-
  sampling periods.
  
      (a) Overview. This test is intended to measure the candidate sampler's ability 
  to prevent excessive overheating of the PM sub 2.5 sample collection filter (or 
  filters) under conditions of elevated solar insolation. The test evaluates 
  radiative effects on filter temperature during a 4-hour period of active sampling 
  as well as during a subsequent 4-hour non- sampling time period prior to filter 
  retrieval. Tests shall be conducted in an environmental chamber which provides the 
  proper radiant wavelengths and energies to adequately simulate the sun's radiant 
  effects under clear conditions at sea level. For additional guidance on conducting 
  solar radiative tests under controlled conditions, consult military standard 
  specification 810-E (Reference 6 in Appendix A of this subpart). The performance 
  parameters tested under this procedure, the corresponding minimum performance 
  specifications, and the applicable test conditions are summarized in Table E-1 of 
  this subpart. Each performance parameter tested, as described or determined in the 
  test procedure, must meet or exceed the associated performance specification to 
  successfully pass this test.
  
      (b) Technical definition. Filter temperature control during sampling is the 
  ability of a sampler to maintain the temperature of the particulate matter sample 
  filter within the specified deviation (5 deg C) from ambient temperature during any 
  active sampling period. 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 from the end of 
  active sample collection of the PM sub 2.5 sample by the sampler until the filter 
  is retrieved from the sampler for laboratory analysis.
  
      (c) Required test equipment. (1) Environmental chamber providing the means, 
  such as a bank of solar- spectrum lamps, for generating or simulating thermal 
  radiation in approximate spectral content and intensity equivalent to solar 
  insolation of 1000 +/- 50 W/m sup 2 inside the environmental chamber. To properly 
  simulate the sun's radiative effects on the sampler, the solar bank must provide 
  the spectral energy distribution and permitted tolerances specified in Table E-2 of 
  this subpart. The solar radiation source area shall be such that the width of the 
  candidate sampler shall not exceed one-half the dimensions of the solar bank. The 
  solar bank shall be located a minimum of 76 cm (30 inches) from any surface of the 
  candidate sampler. To meet requirements of the solar radiation tests, the chamber's 
  internal volume shall be a minimum of 10 times that of the volume of the candidate 
  sampler. Air velocity in the region of the sampler must be maintained continuously 
  during the radiative tests at 2.0 +/- 0.5 m/sec.
  
      (2) Ambient air temperature recorder, range - 30 deg C to +50 deg C, with a 
  resolution of 0.1 deg C and certified accurate to within 0.5 deg C. Ambient air 
  temperature measurements must be made using continuous (analog) recording 
  capability or digital recording at intervals not to exceed 5 minutes.
  
      (3) Flow measurement adaptor (40 CFR part 50, Appendix L, Figure L-30) or 
  equivalent adaptor to facilitate measurement of sampler flow rate at the sampler 
  downtube.
  
      (4) Miniature temperature sensor(s), 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; with a 
  resolution of 0.1 deg C, 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) Solar radiometer, to measure the intensity of the simulated solar radiation 
  in the test environment, range of 0 to approximately 1500 W/m sup 2. Optional 
  capability for continuous (analog) recording or digital recording at intervals not 
  to exceed 5 minutes is recommended.
  
      (6) Sample filter or filters, as specified in section 6 of 40 CFR part 50, 
  Appendix L.
  
      (d) Calibration of test measurement instruments. Submit documentation showing 
  evidence of appropriately recent calibration, certification of calibration 
  accuracy, and NIST-traceability (if required) of all measurement instruments used 
  in the tests. The accuracy of flow rate meters shall be verified at the highest and 
  lowest pressures and temperatures used in the tests and shall be checked at zero 
  and at least one flow rate within +/- 3 percent of 16.7 L/min within 7 days prior 
  to use for this test. 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) Setup of the sampler shall be performed as required in this 
  paragraph (e) and otherwise 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 the solar radiation environmental chamber in its normal configuration for 
  collecting PM sub 2.5 samples (with the inlet installed). The sampler's ambient and 
  filter temperature measurement systems shall be calibrated per the sampler's 
  operating manual within 7 days prior to this test. A sample filter shall be 
  installed for the duration of this test. For sequential samplers, a sample filter 
  shall also be installed in each available sequential channel or station intended 
  for collection of a sequential sample (or at least 5 additional filters for 
  magazine-type sequential samplers) as directed by the sampler's operation or 
  instruction manual.
  
      (2) The miniature temperature sensor shall be temporarily 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 
  such that no external or internal air leakage is created by the sensor 
  installation. The sensor's dimensions and installation shall be selected to 
  minimize temperature measurement uncertainties due to thermal conduction along the 
  sensor mounting structure or sensor conductors. For sequential samplers, similar 
  temperature sensors shall also be temporarily installed in the test sampler to 
  monitor the temperature 1 cm from the center of each filter stored in the sampler 
  for sequential sample operation.
  
      (3) 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 deg and 45 deg 
  from vertical. The intensity of the radiation received by all sampler {pg 38809} 
  surfaces that receive direct radiation shall average 1000 +/- 50 W/m sup 2, 
  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 full, direct radiation 
  as it would or could during normal outdoor installation. Also, the temperature 
  sensor must not be shielded or shaded from the radiation by a sampler part in a way 
  that would not occur at other normal insolation angles or directions.
  
      (4) The solar radiometer shall be installed in a location where it measures 
  thermal radiation that is generally representative of the average thermal radiation 
  intensity that the upper portion of the sampler and sampler inlet receive. The 
  solar radiometer shall be oriented so that it measures the radiation in a plane 
  perpendicular to its angle of incidence.
  
      (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 source that may be present inside the 
  test chamber.
  
      (f) Procedure. (1) Set up the sampler as specified in paragraph (e) of this 
  section and otherwise prepare the sampler for normal sample collection operation as 
  directed in the sampler's operation or instruction manual.
  
      (2) Remove the inlet of the candidate test sampler and install the flow 
  measurement adaptor on the sampler's downtube. Conduct a leak check as described in 
  the sampler's operation or instruction manual. The leak test must be properly 
  passed before other tests are carried out.
  
      (3) Remove the flow measurement adaptor from the downtube and re-install the 
  sampling inlet.
  
      (4) Activate the solar radiation source and verify that the resulting energy 
  distribution prescribed in Table E-2 of this subpart is achieved.
  
      (5) Program the test sampler to conduct a single sampling run of 4 continuous 
  hours. During the 4-hour sampling run, measure and record the radiant flux, ambient 
  temperature, and filter temperature (all filter temperatures for sequential 
  samplers) at intervals not to exceed 5 minutes.
  
      (6) At the completion of the 4-hour sampling phase, terminate the sample 
  period, if not terminated automatically by the sampler. Continue to measure and 
  record the radiant flux, ambient temperature, and filter temperature or 
  temperatures for 4 additional hours at intervals not to exceed 5 minutes. At the 
  completion of the 4-hour post-sampling period, discontinue the measurements and 
  turn off the solar source.
  
      (7) Download all archived sampler data from the test run.
  
      (g) Test results. Chamber temperature control. Examine the continuous record of 
  the chamber radiant flux and verify that the flux met the requirements specified in 
  Table E-2 of this subpart at all times during the test. If not, the entire test is 
  not valid and must be repeated.
  
      (1) Filter temperature measurement accuracy. (i) For each 4-hour test period, 
  calculate the absolute value of the difference between the mean filter temperature 
  indicated by the sampler (active filter) and the mean filter temperature measured 
  by the reference temperature sensor installed within 1 cm downstream of the 
  (active) filter as:
  
  Equation 23
  
  {SEE ILLUSTRATION(S) IN ORIGINAL DOCUMENT}
  
  where:
  
  T sub ind,filter mean filter temperature indicated by the test sampler, deg C; and
  
  T sub ref,filter mean filter temperature measured by the reference temperature 
  sensor, deg C.
  
      (ii) To successfully pass the indicated filter temperature accuracy test, the 
  calculated difference between the measured means (T sub diff,filter) must not 
  exceed 2 deg C for each 4-hour test period.
  
      (2) Ambient temperature measurement accuracy. (i) For each 4-hour test period, 
  calculate the absolute value of the difference between the mean ambient air 
  temperature indicated by the test sampler and the mean ambient air temperature 
  measured by the reference ambient air temperature recorder as:
  
  Equation 24
  
  {SEE ILLUSTRATION(S) IN ORIGINAL DOCUMENT}
  
  where:
  
  T sub ind,ambient mean ambient air temperature indicated by the test sampler, deg 
  C; and
  
  T sub ref,ambient mean ambient air temperature measured by the reference ambient 
  air temperature recorder, deg C.
  
      (ii) To successfully pass the indicated ambient temperature accuracy test, the 
  calculated difference between the measured means (T sub diff,ambient) must not 
  exceed 2 deg C for each 4-hour test period.
  
      (3) Filter temperature control accuracy. (i) For each temperature measurement 
  interval over each 4-hour test period, calculate the difference between the filter 
  temperature indicated by the reference temperature sensor and the ambient 
  temperature indicated by the test sampler as:
  
  Equation 25
  
  {SEE ILLUSTRATION(S) IN ORIGINAL DOCUMENT}
  
      (ii) Tabulate and inspect the calculated differences as a function of time. To 
  successfully pass the indicated filter temperature control test, the calculated 
  difference between the measured values must not exceed 5 deg C for any consecutive 
  intervals covering more than a 30-minute time period.
  
      (iii) For sequential samplers, repeat the test calculations for each of the 
  stored sequential sample filters. All stored filters must also meet the 5 deg C 
  temperature control test.
  
   Sec. 53.58 -- Operational field precision and blank 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 PM sub 2.5 are made at a test site with 
  all of the samplers and then compared to determine replicate precision. Candidate 
  sequential samplers are also subject to a test for possible deposition of 
  particulate matter on inactive filters during a period of storage in the sampler. 
  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 (described in 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. (1) Field precision is defined as the standard 
  deviation or relative standard deviation of a set of PM sub 2.5 measurements 
  obtained concurrently with three or more collocated samplers in actual ambient air 
  field operation.
  
      (2) Storage deposition is defined as the mass of material inadvertently 
  deposited on a sample filter that is stored in a sequential sampler either prior to 
  or subsequent to the active sample collection period.
  
      (c) Test site. Any outdoor test site having PM sub 2.5 concentrations that are 
  reasonably uniform over the test area and that meet the minimum level requirement 
  of paragraph (g)(2) of this section is acceptable for this test.
  
      (d) Required facilities and equipment. (1) An appropriate test site and 
  suitable {pg 38810} electrical power to accommodate three test samplers are 
  required.
  
      (2) Teflon sample filters, as specified in section 6 of 40 CFR part 50, 
  Appendix L, conditioned and preweighed as required by section 8 of 40 CFR part 50, 
  Appendix L, as needed for the test samples.
  
      (e) Test setup. (1) Three identical test samplers shall be installed at the 
  test site in their normal configuration for collecting PM sub 2.5 samples in 
  accordance with the instructions in the associated manual referred to in Sec. 
  53.4(b)(3) and should be in accordance with applicable supplemental guidance 
  provided in Reference 3 in Appendix A of this subpart. The test samplers' 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 the spatial and wind directional effects on sample collection of 
  one sampler on any other sampler.
  
      (2) Each test sampler shall be successfully 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 
  subpart.
  
      (f) Test procedure. (1) Install a conditioned, preweighed filter in each test 
  sampler and otherwise prepare each sampler for normal sample collection. Set 
  identical sample collection start and stop times for each sampler. For sequential 
  samplers, install a conditioned, preweighed specified filter in each available 
  channel or station intended for automatic sequential sample filter collection (or 
  at least 5 additional filters for magazine-type sequential samplers), as directed 
  by the sampler's operation or instruction manual. Since the inactive sequential 
  channels are used for the storage deposition part of the test, they may not be used 
  to collect the active PM sub 2.5 test samples.
  
      (2) Collect either a 24-hour or a 48-hour atmospheric PM sub 2.5 sample 
  simultaneously with each of the three test samplers.
  
      (3) Following sample collection, retrieve the collected sample from each 
  sampler. For sequential samplers, retrieve the additional stored (blank, unsampled) 
  filters after at least 5 days (120 hours) storage in the sampler if the active 
  samples are 24-hour samples, or after at least 10 days (240 hours) if the active 
  samples are 48-hour samples.
  
      (4) Determine the measured PM sub 2.5 mass concentration for each sample in 
  accordance with the applicable procedures prescribed for the candidate method in 
  Appendix L, 40 CFR part 50 of this chapter, in the associated manual referred to in 
  Sec. 53.4(b)(3) and in accordance with supplemental guidance in Reference 2 in 
  Appendix A of this subpart. For sequential samplers, also similarly determine the 
  storage deposition as the net weight gain of each blank, unsampled filter after the 
  5-day (or 10-day) period of storage in the sampler.
  
      (5) Repeat this procedure to obtain a total of 10 sets of any combination of 24-
  hour or 48-hour PM sub 2.5 measurements over 10 test periods. For sequential 
  samplers, repeat the 5-day (or 10-day) storage test of additional blank filters 
  once for a total of two sets of blank filters.
  
      (g) Calculations. (1) Record the PM sub 2.5 concentration for each test sampler 
  for each test period as C sub i,j, where i is the sampler number (i 1,2,3) and j is 
  the test period (j 1,2, . . . 10).
  
      (2)(i) For each test period, calculate and record the average of the three 
  measured PM sub 2.5 concentrations as C sub j where j is the test period:
  
  Equation 26
  
  {SEE ILLUSTRATION(S) IN ORIGINAL DOCUMENT}
  
      (ii) If C sub ave,j < 10  mu g/m sup 3 for any test period, data from that test 
  period are unacceptable, and an additional sample collection set must be obtained 
  to replace the unacceptable data.
  
      (3)(i) Calculate and record the precision for each of the 10 test days as:
  
  Equation 27
  
  {SEE ILLUSTRATION(S) IN ORIGINAL DOCUMENT}
  
      (ii) If C sub ave,j is below 40  mu g/m sup 3 for 24-hour measurements or below 
  30  mu g/m sup 3 for 48-hour measurements; or
  
  Equation 28
  
  {SEE ILLUSTRATION(S) IN ORIGINAL DOCUMENT}
  
      (iii) If C sub ave,j is above 40  mu g/m sup 3 for 24-hour measurements or 
  above 30  mu g/m sup 3 for 48-hour measurements.
  
      (h) Test results. (1) The candidate method passes the precision test if all 10 
  P sub j or RP sub j values meet the specifications in Table E-1 of this subpart.
  
      (2) The candidate sequential sampler passes the blank filter storage deposition 
  test if the average net storage deposition weight gain of each set of blank filters 
  (total of the net weight gain of each blank filter divided by the number of filters 
  in the set) from each test sampler (six sets in all) is less than 50 mu g.
  
   Sec. 53.59 -- Aerosol transport test for Class I equivalent method samplers.
  
      (a) Overview. This test is intended to verify adequate aerosol transport 
  through any modified or air flow splitting components that may be used in a Class I 
  candidate equivalent method sampler such as may be necessary to achieve sequential 
  sampling capability. This test is applicable to all Class I candidate samplers in 
  which the aerosol flow path (the flow path through which sample air passes upstream 
  of sample collection filter) differs from that specified for reference method 
  samplers as specified in 40 CFR part 50, Appendix L. 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 a 
  laboratory challenge aerosol which penetrates to the active sample filter of the 
  candidate equivalent method sampler.
  
      (2) The active sample filter is the exclusive filter through which sample air 
  is flowing during performance of this test.
  
      (3) A no-flow filter is a sample filter through which no sample air is intended 
  to flow during performance of this test.
  
      (4) A channel is any of two or more flow paths that the aerosol may 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 
  in some way from that specified for a reference method sampler in 40 CFR part 50, 
  Appendix L, such as a device or means to allow or cause the aerosol to be routed to 
  one of several channels.
  
      (c) Required facilities and test equipment. (1) Aerosol generation system, as 
  specified in Sec. 53.62(c)(2).
  
      (2) Aerosol delivery system, as specified in Sec. 53.64(c)(2).
  
      (3) Particle size verification equipment, as specified in Sec. 53.62(c)(3).
  
      (4) Fluorometer, as specified in Sec. 53.62(c)(7).
  
      (5) Candidate test 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)(2).
  
      (6) Filters that are appropriate for use with fluorometric methods (e.g., glass 
  fiber). {pg 38811}
  
      (d) Calibration of test measurement instruments. Submit documentation showing 
  evidence of appropriately recent calibration, certification of calibration 
  accuracy, and NIST-traceability (if required) of all measurement instruments used 
  in the tests. The accuracy of flow rate meters shall be verified at the highest and 
  lowest pressures and temperatures used in the tests and shall be checked at zero 
  and at least one flow rate within +/- 3 percent of 16.7 L/min within 7 days prior 
  to use for this test. 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 test sampler shall have its inlet and 
  impactor or impactors removed. The lower end of the down tube shall be reconnected 
  to the filter holder, using an extension of the downtube, if necessary. 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) The test particle delivery system shall be connected to the sampler 
  downtube so that the test aerosol is introduced at the top of the downtube.
  
      (f) Test procedure. (1) All surfaces of the added or modified component or 
  components which come in contact with the aerosol flow shall be thoroughly washed 
  with 0.01 N NaOH and then dried.
  
      (2) Generate aerosol. (i) Generate aerosol composed of oleic acid with a 
  uranine fluorometric tag of 3 +/- 0.25 mu m aerodynamic diameter using a vibrating 
  orifice aerosol generator according to conventions specified in Sec. 53.61(g).
  
      (ii) Check for the presence of satellites and adjust the generator to minimize 
  their production.
  
      (iii) Calculate the aerodynamic particle size using the operating parameters of 
  the vibrating orifice aerosol generator. The calculated aerodynamic diameter must 
  be 3 +/- 0.25 mu m aerodynamic diameter.
  
      (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 resulting measured fluorometric concentration for 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 M sub active (i) where i the active channel number.
  
      (6) Determine the quantity of material collected on each no-flow filter using a 
  calibrated fluorometer. Record the mass of fluorometric material on each no- flow 
  filter as M sub no-flow.
  
      (7) Using 0.01 N NaOH, wash the surfaces of the added component or components 
  which contact the aerosol flow. Determine the quantity of material collected using 
  a calibrated fluorometer. Record the mass of fluorometric material collected in the 
  wash as M sub wash.
  
      (8) Calculate the aerosol transport as:
  
  Equation 29
  
  {SEE ILLUSTRATION(S) IN ORIGINAL DOCUMENT}
  
  where:
  
  i the active channel number.
  
      (9) Repeat paragraphs (f)(1) through (8) of this section for each channel, 
  making each channel in turn the exclusive active channel.
  
      (g) Test results. The candidate Class I sampler passes the aerosol transport 
  test if T sub (i) is at least 97 percent for each channel.
  
  Tables to Subpart E of Part 53
  
  
   Table E-1.-Summary of Test Requirements for Reference and Class I
   Equivalent Methods for PM sub 2.5
   
   Subpart E Procedure   Performance Test      Performance
                                               Specification
   
   Sec. 53.52 Sampler    Sampler leak check    External leakage: 80
   leak check test       facility              mL/min, max Internal
                                               leakage: 80 mL/min,
                                               max
   Sec. 53.53 Base flow  Sample flow rate: 1.  1. 16.67 +  5%,
   rate test             Mean 2. Regulation    L/min 2. 2%, max 3.
                         3. Meas. accuracy 4.  2%, max 4. 0.3%, max
                         CV accuracy 5. Cut-   5. Flow rate cut-off
                         off                   if flow rate
                                               deviates more than
                                               10% from design flow
                                               rate for >60 +  30
                                               seconds
   Sec. 53.54 Power      Sample flow rate: 1.  1. 16.67 +  5%,
   interruption test     Mean 2. Regulation    L/min 2. 2%, max 3.
                         3. Meas. accuracy 4.  2%, max 4. 0.3%, max
                         CV accuracy 5.        5. +  2 min if >60
                         Occurrence time of    seconds 6. +  20
                         power interruptions   seconds 7. +  2%,
                         6. Elapsed sample     max
                         time 7. Sample
                         volume
   Sec. 53.55            Sample flow rate: 1.  1. 16.67 +  5%,
   Temperature and line  Mean 2. Regulation    L/min 2. 2 %, max 3.
   voltage effect test   3. Meas. accuracy 4.  2 %, max 4. 0.3 %,
                         CV accuracy 5.        max 5. 2 deg C
                         Temperature meas.
                         accuracy 6. Proper
                         operation
   Sec. 53.56            Sample flow rate: 1.  1. 16.67 +  5%,
   Barometric pressure   Mean 2. Regulation    L/min 2. 2%, max 3.
   effect test           3. Meas. accuracy 4.  2%, max 4. 0.3%, max
                         CV accuracy 5.        5. 10 mm Hg
                         Pressure meas.
                         accuracy 6. Proper
                         operation
   Sec. 53.57 Filter     1. Filter temp meas.  1. 2 deg C 2. 2 deg
   temperature control   accuracy 2. Ambient   C 3. Not more than 5
   test                  temp. meas. accuracy  deg C above ambient
                         3. Filter temp        temp. for more than
                         control accuracy,     30 min
                         sampling and non-
                         sampling
   Sec. 53.58 Field      1. Measurement        1. P sub j <2  mu
   precision test        precision 2. Storage  g/m sup 3 for conc.
                         deposition test for   <40  mu g/m sup 3
                         sequential samplers   (24-hr) or <30  mu
                                               g/m sup 3 (48-hr);
                                               or RP sub j < 5% for
                                               conc. >40 mu g/m3
                                               (24-hr) or >30 mu
                                               g/m3 (48-hr) 2. 50
                                               mu g, max weight
                                               gain
   The Following
   Requirement is
   Applicable to
   Candidate Equivalent
   Methods Only
   Sec. 53.59 Aerosol    Aerosol transport     97%, min, for all
   transport test                              channels
   
   Subpart E Procedure   Test Conditions       Part 50, Appendix L
                                               Reference
   
   Sec. 53.52 Sampler    Controlled leak flow  Sec. 7.4.6
   leak check test       rate of 80 mL/min
   Sec. 53.53 Base flow  (a) 6-hour normal     Sec. 7.4.1 Sec.
   rate test             operational test      7.4.2 Sec. 7.4.3
                         plus flow rate cut-   Sec. 7.4.4 Sec.
                         off test (b) Nominal  7.4.5
                         conditions (c)
                         Additional 55 mm Hg
                         pressure drop to
                         simulate loaded
                         filter (d) Variable
                         flow restriction
                         used for cut-off
                         test
   Sec. 53.54 Power      (a) 6-hour normal     Sec. 7.4.1 Sec.
   interruption test     operational test (b)  7.4.2 Sec. 7.4.3
                         Nominal conditions    Sec. 7.4.5 Sec.
                         (c) Additional 55 mm  7.4.12 Sec. 7.4.13
                         Hg pressure drop to   Sec. 7.4.15.4 Sec.
                         simulate loaded       7.4.15.5
                         filter (d) 6 power
                         interruptions of
                         various durations
   Sec. 53.55            (a) 6-hour normal     Sec. 7.4.1 Sec.
   Temperature and line  operational test (b)  7.4.2 Sec. 7.4.3
   voltage effect test   Nominal conditions    Sec. 7.4.5 Sec.
                         (c) Additional 55 mm  7.4.8 Sec. 7.4.15.1
                         Hg pressure drop to
                         simulate loaded
                         filter (d) Ambient
                         temperature at -20
                         and +40 deg C (e)
                         Line voltage: 105
                         Vac to 125 Vac
   Sec. 53.56            (a) 6-hour normal     Sec. 7.4.1 Sec.
   Barometric pressure   operational test (b)  7.4.2 Sec. 7.4.3
   effect test           Nominal conditions    Sec. 7.4.5 Sec.
                         (c) Additional 55 mm  7.4.9
                         Hg pressure drop to
                         simulate loaded
                         filter (d)
                         Barometric pressure
                         at 600 and 800 mm
                         Hg.
   Sec. 53.57 Filter     (a) 4-hour simulated  Sec. 7.4.8 Sec.
   temperature control   solar radiation,      7.4.10 Sec. 7.4.11
   test                  sampling (b) 4-hour
                         simulated solar
                         radiation, non-
                         sampling (c) Solar
                         flux of 1000 W/m sup
                         2
   Sec. 53.58 Field      (a) 3 collocated      Sec. 5.1 Sec. 7.3.5
   precision test        samplers at 1 site    Sec. 8 Sec. 9 Sec.
                         for at least 10 days  10
                         (b) PM sub 2.5
                         conc.>10  mu g/m sup
                         3 (c) 24- or 48-hour
                         samples (d) 5- or
                         10-day storage
                         period for inactive
                         stored filters
   The Following
   Requirement is
   Applicable to
   Candidate Equivalent
   Methods Only
   Sec. 53.59 Aerosol    Determine aerosol
   transport test        transport through
                         any new or modified
                         components with
                         respect to the
                         reference method
                         sampler before the
                         filter for each
                         channel.
   
   
  
   Table E-2.-Spectral Energy Distribution and Permitted Tolerance
   for Conducting Radiative Tests
   
   Chacteristic                   Spectral Region
                   Ultraviolet     Visible         Infrared
   
   Bandwidth (mu   0.28 to 0.32    0.40 to 0.78    0.78 to 3.00
   m)              10.32 to 0.40
   Irradiance      5 56            450 to 550      439
   (W/m sup 2 )
   Allowed         2   35% 2       2   10%         2   10%
   Tolerance       25%
   
   
   {pg 38813}
  
  Figures to Subpart E of Part 53
  
  Figure E-1.- Designation Testing Checklist
  
  DESIGNATION TESTING CHECKLIST
  
   X X X
  
  Auditee Auditor signature Date
  
  
   Compliance Status: Y   Yes N   No NA   Not applicable/Not
   available
                         Verification          Verified by Direct
                                               Observation of
                                               Process or of
                                               Documented Evidence:
                                               Performance, Design
                                               or Application Spec.
                                               Corresponding to
                                               Sections of 40 CFR
                                               Part 53 or 40 CFR
                                               Part 50, Appendix L
                                               Y
   
   The Following Requirements Apply Only to Class I Candidate
   Equivalent Methods
   
     Compliance Status: Y   Yes N   No NA   Not    Verification
              applicable/Not available             Comments
                                                   (Includes
                                                   documentation
                                                   of who, what,
                                                   where, when,
                                                   why) (Doc.   ,
                                                   Rev.   , Rev.
                                                   Date)
   
                   N               NA
                   Performance
                   Specification
                   Tests
                   Sample flow
                   rate
                   coefficient of
                   variation
                   (Sec. 53.53)
                   (L 7.4.3)
                   Filter
                   temperature
                   control
                   (sampling)
                   (Sec. 53.57)
                   (L 7.4.10)
                   Elapsed sample
                   time accuracy
                   (Sec. 53.54)
                   (L 7.4.13)
                   Filter
                   temperature
                   control (post
                   sampling)
                   (Sec. 53.57)
                   (L 7.4.10)
                   Application
                   Specification
                   Tests
                   Field
                   Precision
                   (Sec. 53.58)
                   (L 5.1)
                   Meets all
                   Appendix L
                   requirements
                   (part 53,
                   subpart A,
                   Sec.
                   53.2(a)(3))
                   (part 53,
                   subpart E,
                   Sec.
                   53.51(a),(d))
                   Filter
                   Weighing (L-8)
                   Field Sampling
                   Procedure
                   (Sec. 53.30,
                   .31, .34)
                   Design
                   Specification
                   Tests
                   Filter ( L-6)
                   Range of
                   Operational
                   Conditions (L-
                   7.4.7)
   The Following
   Requirements
   Apply Only to
   Class I
   Candidate
   Equivalent
   Methods
                   Aerosol
                   Transport
                   (Sec. 53.59)
   
   
   {pg 38814}
  
  Figure E-2.-Product Manufacturing Checklist
  
  PRODUCT MANUFACTURING CHECKLIST
  
   X X  X
  
  Auditee Auditor signature Date
  
  
   Compliance Status: Y
     Yes N   No NA  
   Not applicable/Not
   available
                         Verification          Verified by Direct
                                               Observation of
                                               Process or of
                                               Documented Evidence:
                                               Performance, Design
                                               or Application Spec.
                                               Corresponding to
                                               Sections of 40 CFR
                                               Part 53 or 40 CFR
                                               Part 50, Appendix L
                                               Y
   
   Compliance Status: Y   Yes N   No NA   Not        Verification
   applicable/Not available                          Comments
                                                     (Includes
                                                     documentation
                                                     of who, what,
                                                     where, when,
                                                     why) (Doc.   ,
                                                     Rev.   , Rev.
                                                     Date)
   
                   N                    NA
                   Performance
                   Specification Tests
                   Assembled
                   operational
                   performance (Burn-
                   in test) (Sec.
                   53.53)
                   Sample flow rate
                   (Sec. 53.53) (L
                   7.4.1, L 7.4.2)
                   Sample flow rate
                   regulation (Sec.
                   53.53) (L 7.4.3)
                   Flow rate and
                   average flow rate
                   measurement
                   accuracy (Sec.
                   53.53) (L 7.4.5)
                   Ambient air
                   temperature
                   measurement
                   accuracy (Sec.
                   53.55) (L 7.4.8)
                   Ambient barometric
                   pressure
                   measurement
                   accuracy (Sec.
                   53.56) (L 7.4.9)
                   Sample flow rate
                   cut-off (Sec.
                   53.53) (L 7.4.4)
                   Sampler leak check
                   facility (Sec.
                   53.52) (L 7.4.6)
                   Application
                   Specification Tests
                   Flow rate
                   calibration
                   transfer standard
                   (L-9.2)
                   Operational
                   /Instructional
                   manual (L-7.4.18)
                   Design
                   Specification Tests
                   Impactor (jet
                   width) (Sec.
                   53.51(d)(1)) (L-
                   7.3.4.1)
                   Surface finish
                   (Sec. 53.51( d)(2))
                   (L-7.3.7)
   
   
  Appendix A to Subpart E of Part 53--References
  
      (1) Quality systems--Model for quality assurance in design, development, 
  production, installation and servicing, ISO 9001. 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) Copies of section 2.12 of the Quality Assurance Handbook for Air Pollution 
  Measurement Systems, Volume II, Ambient Air Specific Methods, EPA/600/R-94/038b, 
  are available from Department E (MD-77B), U.S. EPA, Research Triangle Park, NC 
  27711.
  
      (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) 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).
  
      (6) Military standard specification (mil. spec.) 810-E 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.
  
      e. Subpart F is added to read as follows:
  
  Subpart F-Procedures for Testing Performance Characteristics of Class II Equivalent 
  Methods for PM sub 2.5
  
  Sec.
  
  53.60 General provisions.
  
  53.61 Test conditions for PM sub 2.5 reference method equivalency.
  
  53.62 Test procedure: Full wind tunnel test.
  
  53.63 Test procedure: Wind tunnel inlet aspiration test.
  
  53.64 Test procedure: Static fractionator test.
  
  53.65 Test procedure: Loading test.
  
  53.66 Test procedure: Volatility test.
  
  Tables to Subpart F of Part 53
  
  Table F-1- Performance Specifications for PM sub 2.5 Class II Equivalent Samplers
  
  Table F-2-Particle Sizes and Wind Speeds for Full Wind Tunnel Test, Wind Tunnel {pg 
  38815} Inlet Aspiration Test, and Static Chamber Test
  
  Table F-3-Critical Parameters of Idealized Ambient Particle Size Distributions
  
  Table F-4-Estimated Mass Concentration Measurement of PM sub 2.5 for Idealized 
  Coarse Aerosol Size Distribution
  
  Table F-5-Estimated Mass Concentration Measurement of PM sub 2.5 for Idealized 
  "Typical" Coarse Aerosol Size Distribution
  
  Table F-6 Estimated Mass Concentration Measurement of PM sub 2.5 for Idealized Fine 
  Aerosol Size Distribution
  
  Figures to Subpart F of Part 53
  
  Figure F-1- 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 PM sub 2.5
  
   Sec. 53.60 -- General provisions.
  
      (a) This subpart sets forth the specific requirements that a PM sub 2.5 sampler 
  associated with a candidate Class II equivalent method must meet to be designated 
  as an equivalent method for PM sub 2.5. 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 and 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 
  paragraph (d) of this section.
  
      (d) Except as provided in paragraphs (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 40 CFR part 50, Appendix L, and in subpart E of 
  this part, except for specific deviations of the inlet, fractionator, or filter.
  
      (1) Inlet deviation. A sampler which has been determined to be a Class II 
  sampler solely because the design or construction of its inlet deviates from the 
  design or construction of the inlet 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. 53.63 
  (wind tunnel 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 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 its effective filtration area deviates from that of the 
  reference method filter 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) 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 
  effectiveness (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 candidate sampler is challenged at wind speeds of 2 and 24 
  km/hr with monodisperse aerosols of the size specified in Table F-2 of this 
  subpart. The experimental test results are then integrated with three idealized 
  ambient distributions (typical, fine, and coarse) to yield the expected mass 
  concentration measurement for each. The acceptance criteria are based on the 
  results of this numerical analysis and the particle diameter for which the sampler 
  effectiveness is 50 percent.
  
      (2) Wind tunnel inlet aspiration test. The wind tunnel inlet aspiration test 
  directly compares the inlet of the candidate sampler to the inlet of a reference 
  method sampler with the single-sized, liquid, monodisperse challenge aerosol 
  specified in Table F-2 of this subpart 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 inlet and the reference method inlet.
  
      (3) Static fractionator test. The static fractionator test determines the 
  effectiveness of the candidate sampler's 2.5-micron fractionator under static 
  conditions for aerosols of the size specified in Table F-2 of this subpart. The 
  numerical analysis procedures and acceptance criteria are identical to those in the 
  full wind tunnel test.
  
      (4) Loading test. The loading test is conducted to ensure that the performance 
  of a candidate sampler is not significantly affected by the amount of particulate 
  deposited on its interior surfaces between periodic cleanings. The candidate 
  sampler is artificially loaded by sampling a test environment containing 
  aerosolized, standard test dust. The duration of the loading phase is dependent on 
  both the time between cleaning as specified by the candidate method and the aerosol 
  mass concentration in the test environment. After loading, the candidate's 
  performance must then be evaluated by Sec. 53.62 (full wind tunnel evaluation), 
  Sec. 53.64 (wind tunnel inlet aspiration test), or Sec. 53.64 (static fractionator 
  test). If the results of the appropriate test 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 cleaning frequency proposed 
  by the candidate method and that has been demonstrated to be acceptable by this 
  test.
  
      (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 during a blow-
  off time period. Residual mass is then calculated as the weight of the filter after 
  the blow-off phase is subtracted from the initial weight of the filter. Acceptance 
  criteria are based on a comparison of the residual mass measured by the candidate 
  sampler (corrected for flow rate variations from that of the reference method) to 
  the {pg 38816} residual mass measured by the reference method sampler for several 
  specified clean air sampling time periods.
  
      (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 
  submit as part of the application, a Designation Testing Checklist (Figure F-1 of 
  this subpart) which has been completed and signed by an ISO-certified auditor.
  
   Sec. 53.61 -- Test conditions for PM sub 2.5 reference method equivalency.
  
      (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 section 7.4.18 of 40 CFR part 50, Appendix L.
  
      (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 
  section 7.4.18 of 40 CFR part 50, Appendix L, 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 section 7.4.18 of 40 CFR part 50, Appendix L. 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 set up, calibrated, and maintained by qualified personnel according to the 
  manufacturer's instructions. All appropriate calibration information and manuals 
  for this equipment shall be kept on file.
  
      (g) Vibrating orifice aerosol generator conventions. This section prescribes 
  conventions regarding the use of the vibrating orifice aerosol generator (VOAG) for 
  the size- selective performance tests outlined in Secs. 53.62, 53.63, 53.64, and 
  53.65.
  
      (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:
  
  Equation 1
  
  {SEE ILLUSTRATION(S) IN ORIGINAL DOCUMENT}
  
  where:
  
  D sub p particle physical diameter, mu m;
  
  Q liquid volumetric flow rate, mu m sup 3/sec;
  
  C sub vol volume concentration (particle volume produced per drop volume), 
  dimensionless; and
  
  f frequency of applied vibrational signal, 1/sec.
  
      (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 ( rho sub o 1 g/m sup 3) 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:
  
  Equation 2
  
  {SEE ILLUSTRATION(S) IN ORIGINAL DOCUMENT}
  
  where:
  
  D sub ae particle aerodynamic diameter, mu m;
  
   rho sub p particle density, g/cm sup 3;
  
   rho sub o aerodynamic particle density 1 g/m sup 3;
  
  C sub Dp Cunningham's slip correction factor for physical particle diameter, 
  dimensionless; and
  
  C sub Dae 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:
  
  Equation 3
  
  {SEE ILLUSTRATION(S) IN ORIGINAL DOCUMENT}
  
  or
  
  Equation 4
  
  {SEE ILLUSTRATION(S) IN ORIGINAL DOCUMENT}
  
      (iv) Since the slip correction factor is itself a function of particle 
  diameter, the aerodynamic diameter in Equation 2 of paragraph (g)(1)(ii) of this 
  section cannot be solved directly but must be determined by iteration.
  
      (2) Solid particle generation. (i) Solid particle tests performed 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 (C sub 20H sub 12O sub 5, FW 332.31, CAS 2321-07-5) 
  with aqueous ammonia. Guidelines for preparation of fluorescein solutions of the 
  desired volume concentration (C sub vol) 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/cm sup 3 shall be used.
  
      (ii) Mass deposits of ammonium fluorescein shall be extracted and analyzed 
  using solutions of 0.01 N ammonium hydroxide.
  
      (3) Liquid particle generation. (i) 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 (C sub 18H sub 34O sub 2, FW 282.47, CAS 112-80-1) has a 
  density of 0.8935 g/cm sup 3. 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 {pg 38817} dispensed mass 
  by the oleic acid density.
  
      (ii) 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 (C sub 20H sub 10O sub 5Na sub 2, FW 376.3, CAS 518-47-8) 
  is the disodium salt of fluorescein and has a density of 1.53 g/cm sup 3. 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.
  
      (iii) Calculation of the physical diameter of the particles produced by the 
  VOAG requires knowledge of the liquid solution's volume concentration (C sub vol). 
  Because uranine is essentially insoluble in oleic acid, the total particle volume 
  is the sum of the oleic acid volume and the uranine volume. The volume 
  concentration of the liquid solution shall be calculated as:
  
  Equation 5
  
  {SEE ILLUSTRATION(S) IN ORIGINAL DOCUMENT}
  
  where:
  
  V sub u uranine volume, ml;
  
  V sub oleic oleic acid volume, ml;
  
  V sub sol total solution volume, ml;
  
  M sub u uranine mass, g;
  
   rho sub u uranine density, g/cm sup 3;
  
  M sub oleic oleic acid mass, g; and
  
   rho  sub oleic oleic acid density, g/cm sup 3.
  
      (iv) For purposes of converting the particles' physical diameter to aerodynamic 
  diameter, the density of the generated particles shall be calculated as:
  
  Equation 6
  
  {SEE ILLUSTRATION(S) IN ORIGINAL DOCUMENT}
  
      (v) Mass deposits of oleic acid shall be extracted and analyzed using solutions 
  of 0.01 N sodium hydroxide.
  
   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 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 (D sub p50) at each wind speed is then determined from the corrected 
  effectiveness curves. The two resultant penetration curves are then each 
  numerically integrated with three idealized ambient particle size distributions to 
  provide six estimates 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 in the test section.
  
      (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 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 of the particle 
  population. 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 sizer, time-of-flight apparatus). The 
  instrument must be capable of measuring solid and liquid test particles with a size 
  resolution of 0.1 mu m or less. The accuracy of the particle size verification 
  technique shall be 0.15 mu 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 2 percent and an accuracy 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 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. After cross-sectional uniformity has been 
  confirmed, 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 paragraph (d)(5) 
  of this section. 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 fluorometer 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.
  
      (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. {pg 38818}
  
      (ii) Measure the wind speed 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 paragraph (c)(4) of this section.
  
      (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. (i) Generate particles of a size specified in Table F-2 
  of this subpart using a vibrating orifice aerosol generator.
  
      (ii) Check for the presence of satellites and adjust the generator as 
  necessary.
  
      (iii) Calculate the physical particle size using the operating parameters of 
  the vibrating orifice aerosol generator and record.
  
      (iv) 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 
  technique does not provide a direct measure of aerodynamic diameter, the geometric 
  mean aerodynamic diameter of the challenge aerosol must be calculated using the 
  known density of the particle and the measured mean physical diameter. The 
  determined geometric mean aerodynamic diameter of the test aerosol must be within 
  0.15 mu m of the aerodynamic diameter calculated from the operating parameters of 
  the vibrating orifice aerosol generator. The geometric 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 (paragraph 
  (c)(5) of this section). 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:
  
  Equation 7
  
  {SEE ILLUSTRATION(S) IN ORIGINAL DOCUMENT}
  
  where:
  
  i replicate number;
  
  j isokinetic sampler number;
  
  M sub iso mass of material collected with the isokinetic sampler;
  
  Q isokinetic sampler volumetric flow rate; and
  
  t sampling time.
  
      (iii) Calculate and record the mean mass concentration as:
  
  Equation 8
  
  {SEE ILLUSTRATION(S) IN ORIGINAL DOCUMENT}
  
  where:
  
  i replicate number;
  
  j isokinetic sampler number; and
  
  n total number of isokinetic samplers.
  
      (iv) Precision calculation. (A) Calculate the coefficient of variation of the 
  mass concentration measurements as:
  
  Equation 9
  
  {SEE ILLUSTRATION(S) IN ORIGINAL DOCUMENT}
  
  where:
  
  i replicate number;
  
  j isokinetic sampler number; and
  
  n total number of isokinetic samplers.
  
      (B) If the value of CV sub iso(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 1 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 (paragraph (c)(6) of this section).
  
      (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 C sub iso(i) as in 
  paragraph (d)(5)(ii) of this section.
  
      (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 paragraph 
  (c)(1) of this section 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:
  
  Equation 10
  
  {SEE ILLUSTRATION(S) IN ORIGINAL DOCUMENT}
  
  where:
  
  i replicate number;
  
  M sub cand mass of material collected with the candidate sampler;
  
  Q candidate sampler volumetric flow rate; and
  
  t sampling time. {pg 38819}
  
      (iv)(A) Calculate and record the sampling effectiveness of the candidate 
  sampler as:
  
  Equation 11
  
  {SEE ILLUSTRATION(S) IN ORIGINAL DOCUMENT}
  
  where:
  
  i replicate number.
  
      (B) If a single isokinetic sampler is used for the determination of particle 
  mass concentration, replace C sub iso(i) with C sub iso.
  
      (8) Replicate measurements and calculation of mean sampling effectiveness. (i) 
  Repeat steps in paragraphs (d)(5) through (d)(7) of this section, as appropriate, 
  to obtain a 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 as:
  
  Equation 12
  
  {SEE ILLUSTRATION(S) IN ORIGINAL DOCUMENT}
  
  where:
  
  i replicate number; and
  
  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:
  
  Equation 13
  
  {SEE ILLUSTRATION(S) IN ORIGINAL DOCUMENT}
  
  where:
  
  i replicate number, and
  
  n number of replicates.
  
      (B) If the value of CV sub E exceeds 10 percent, the test run (steps in 
  paragraphs (d)(2) through (d)(8) of this section) must be repeated until an 
  acceptable value is obtained.
  
      (9) Repeat steps in paragraphs (d)(2) through (d)(8) of this section until the 
  sampling effectiveness has been measured for all particle sizes specified in Table 
  F-2 of this subpart.
  
      (10) Repeat steps in paragraphs (d)(1) through (d)(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 average sampling 
  effectiveness of the candidate sampler as a function of aerodynamic particle 
  diameter (D sub ae) 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 mu m and 0 percent at an aerodynamic 
  particle size of 10 mu m. Correction for the presence of multiplets shall be 
  performed using the techniques presented by Marple, et al (1987). This multiplet-
  corrected effectiveness curve shall be used for all remaining calculations in this 
  paragraph (e).
  
      (2) Cutpoint determination. For each wind speed determine the sampler Dp sub 50 
  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, 
  multiplet-corrected 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:
  
  Equation 14
  
  {SEE ILLUSTRATION(S) IN ORIGINAL DOCUMENT}
  
  where:
  
  C sub cand(est) estimated mass concentration measurement for the test sampler,  mu 
  g/m sup 3; and
  
  C sub ref(est)  estimated mass concentration measurement for the reference sampler, 
   mu g/m sup 3 (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 (e)(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 R sub c 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 ensure that the aspiration of a Class II candidate sampler is 
  such that it representatively extracts an ambient aerosol at elevated wind speeds. 
  This wind tunnel test uses a single-sized, 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) Setup. The candidate and reference method samplers shall be operated with 
  the PM sub 2.5 fractionation device removed from the flow path throughout this 
  entire test procedure. Modifications to accommodate this requirement shall be 
  limited to removal of the fractionator and insertion of the filter holder directly 
  into the downtube of the inlet.
  
      (e) Test procedure-(1) Establish the wind tunnel test atmosphere. Follow the 
  procedures in Sec. 53.62(d)(1) through (d)(4) to establish a test atmosphere for 
  one of the two wind speeds specified in Table F-2 of this subpart. {pg 38820}
  
      (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 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 reference method 
  sampler using a calibrated fluorometer. Calculate and record the mass concentration 
  as:
  
  Equation 15
  
  {SEE ILLUSTRATION(S) IN ORIGINAL DOCUMENT}
  
  where:
  
  i replicate number;
  
  M sub ref mass of material collected with the reference method sampler;
  
  Q reference method sampler volumetric flow rate; and
  
  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:
  
  Equation 16
  
  {SEE ILLUSTRATION(S) IN ORIGINAL DOCUMENT}
  
  where:
  
  i replicate number;
  
  M sub cand mass of material collected with the candidate sampler;
  
  Q candidate sampler volumetric flow rate; and
  
  t sampling time.
  
      (iii) Remove the candidate sampler from the wind tunnel.
  
      (4) Repeat steps in paragraphs (d) (2) and (d)(3) of this section. Alternately 
  measure the tunnel concentration with the reference sampler and the candidate 
  sampler until four reference sampler and three candidate sampler measurements of 
  the wind tunnel concentration are obtained.
  
      (5) Calculations. (i) Calculate and record aspiration ratio for each candidate 
  sampler run as:
  
  Equation 17
  
  {SEE ILLUSTRATION(S) IN ORIGINAL DOCUMENT}
  
  where:
  
  i replicate number.
  
      (ii) Calculate and record the mean aspiration ratio as:
  
  Equation 18
  
  {SEE ILLUSTRATION(S) IN ORIGINAL DOCUMENT}
  
  where:
  
  i replicate number; and
  
  n total number of measurements of aspiration ratio.
  
      (iii) Precision of the aspiration ratio. (A) Calculate and record the precision 
  of the aspiration ratio measurements as the coefficient of variation as:
  
  Equation 19
  
  {SEE ILLUSTRATION(S) IN ORIGINAL DOCUMENT}
  
  where:
  
  i replicate number; and
  
  n total number of measurements of aspiration ratio.
  
      (B) If the value of CV sub A exceeds 10 percent, the entire test procedure must 
  be repeated.
  
      (f) Evaluation of test results. The candidate method passes the inlet 
  aspiration test if all values of A 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 on the candidate sampler's after filter 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 sampler's after filter versus that 
  which exists in a static chamber. A calibrated fluorometer shall 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 
  existing in the test atmosphere.
  
      (c) Facilities and equipment required-(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 shall be 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). 
  Validation particle size and quality shall be conducted at a point directly 
  upstream of the fractionator. {pg 38821}
  
      (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 in addition to the inlet of the candidate method 
  size fractionator. Validation of particle size and quality 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 
  aerosol shall be delivered to a manifold with two symmetrical branching legs. One 
  of the legs, referred to as the bypass leg, shall allow the challenge aerosol to 
  pass unfractionated to the detector. The other leg shall accommodate the 
  fractionation device.
  
      (3) Particle concentration measurement- (i) Fluorometry. Refer to Sec. 
  53.62(c)(7).
  
      (ii) Number concentration measurement. A number counting particle sizer may be 
  used in conjunction with the divided flow test apparatus in lieu of fluorometric 
  measurement. This device must have a minimum range of 1 to 10 mu m, a resolution of 
  0.1 mu m, and an accuracy of 0.15 mu m 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 and downtube from the candidate fractionator. 
  All tests procedures shall be conducted with the inlet and downtube 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 
  Society of Automotive Engineers Aerospace Material Specification (SAE AMS) 2404C, 
  Electroless Nickel Plating (Reference 3 in Appendix A of Subpart F).
  
      (e) Test procedure: Wash-off method-(1) Clean the candidate sampler. Note: The 
  procedures in this step may be omitted if this test is being used to evaluate the 
  fractionator after being loaded as specified in Sec. 53.65.
  
      (i) Clean and dry the internal surfaces of the candidate sampler.
  
      (ii) Prepare the internal fractionator surfaces in strict accordance with the 
  operating instructions specified in the sampler's operating manual referred to in 
  section 7.4.18 of 40 CFR part 50, Appendix L.
  
      (2) Generate aerosol. Follow the procedures for aerosol generation prescribed 
  in Sec. 53.62(d)(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(d)(4).
  
      (4) Determine effectiveness for the particle size being produced. (i) Collect 
  particles downstream of the fractionator on an appropriate filter over a time 
  period such that the relative error of the fluorometric measurement is less than 
  5.0 percent.
  
      (ii) Determine the quantity of material collected on the after filter of the 
  candidate method using a calibrated fluorometer. Calculate and record the aerosol 
  mass concentration for the sampler filter as:
  
  Equation 20
  
  {SEE ILLUSTRATION(S) IN ORIGINAL DOCUMENT}
  
  where:
  
  i replicate number;
  
  M sub cand mass of material collected with the candidate sampler;
  
  Q candidate sampler volumetric flowrate; and
  
  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:
  
  Equation 21
  
  {SEE ILLUSTRATION(S) IN ORIGINAL DOCUMENT}
  
  where:
  
  i replicate number;
  
  M sub wash mass of material washed from the interior surfaces of the fractionator;
  
  Q candidate sampler volumetric flowrate; and
  
  t sampling time.
  
  (iv) Calculate and record the sampling effectiveness of the test sampler for this 
  particle size as:
  
  Equation 22
  
  {SEE ILLUSTRATION(S) IN ORIGINAL DOCUMENT}
  
  where:
  
  i replicate number.
  
      (v) Repeat steps in paragraphs (e)(4) of this section, as appropriate, to 
  obtain a minimum of three replicate measurements of sampling effectiveness. Note: 
  The procedures for loading the candidate in Sec. 53.65 must be repeated between 
  repetitions if this test is being used to evaluate the fractionator after being 
  loaded as specified in Sec. 53.65.
  
      (vi) Calculate and record the average sampling effectiveness of the test 
  sampler as:
  
  Equation 23
  
  {SEE ILLUSTRATION(S) IN ORIGINAL DOCUMENT}
  
  where:
  
  i replicate number; and
  
  n number of replicates.
  
      (vii)(A) Calculate and record the coefficient of variation for the replicate 
  sampling effectiveness measurements of the test sampler as:
  
  Equation 24
  
  {SEE ILLUSTRATION(S) IN ORIGINAL DOCUMENT}
  
  where:
  
  i replicate number; and
  
  n total number of measurements.
  
      (B) If the value of CV sub E exceeds 10 percent, then steps in paragraphs (e) 
  (2) through (e)(4) of this section must be repeated.
  
      (5) Repeat steps in paragraphs (e) (1) through (e)(4) of this section for each 
  particle size 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(d)(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(d)(4).
  
      (3) Introduce particles into chamber. Introduce the particles into the static 
  chamber and allow the particle concentration to stabilize.
  
      (4) Install and operate the candidate sampler's fractionator and its after-
  filter and at least four total filters. (i) Install the fractionator and an array 
  of four or more equally spaced total filter samplers such that the total filters 
  surround and are in the same plane as the inlet of the fractionator.
  
      (ii) Simultaneously collect particles onto appropriate filters with the total 
  filter samplers and the fractionator for a time period such that the relative error 
  {pg 38822} 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:
  
  Equation 25
  
  {SEE ILLUSTRATION(S) IN ORIGINAL DOCUMENT}
  
  where:
  
  i replicate number;
  
  j total filter sampler number;
  
  M sub total mass of material collected with the total filter sampler;
  
  Q total filter sampler volumetric flowrate; and
  
  t sample time.
  
      (ii) Calculate and record the mean mass concentration as:
  
  Equation 26
  
  {SEE ILLUSTRATION(S) IN ORIGINAL DOCUMENT}
  
  where:
  
  n total number of samplers;
  
  i replicate number; and
  
  j filter sampler number.
  
      (iii) (A) Calculate and record the coefficient of variation of the total mass 
  concentration as:
  
  Equation 27
  
  {SEE ILLUSTRATION(S) IN ORIGINAL DOCUMENT}
  
  where:
  
  i replicate number;
  
  j total filter sampler number; and
  
  n number of total filter samplers.
  
      (B) If the value of CV sub total 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 (f)(5) of this 
  section must be repeated.
  
      (6) Determine the effectiveness of the candidate sampler. (i) Determine the 
  quantity of material collected on the candidate sampler's after filter using a 
  calibrated fluorometer. Calculate and record the mass concentration for the 
  candidate sampler as:
  
  Equation 28
  
  {SEE ILLUSTRATION(S) IN ORIGINAL DOCUMENT}
  
  where:
  
  i replicate number;
  
  M sub cand mass of material collected with the candidate sampler;
  
  Q candidate sampler volumetric flowrate; and
  
  t sample time.
  
      (ii) Calculate and record the sampling effectiveness of the candidate sampler 
  as:
  
  Equation 29
  
  {SEE ILLUSTRATION(S) IN ORIGINAL DOCUMENT}
  
  where:
  
  i replicate number.
  
      (iii) Repeat step in paragraph (f)(4) through (f)(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:
  
  Equation 30
  
  {SEE ILLUSTRATION(S) IN ORIGINAL DOCUMENT}
  
  where:
  
  i replicate number.
  
      (v)(A) Calculate and record the coefficient of variation for the replicate 
  sampling effectiveness measurements of the test sampler as:
  
  Equation 31
  
  {SEE ILLUSTRATION(S) IN ORIGINAL DOCUMENT}
  
  where:
  
  i replicate number; and
  
  n number of measurements of effectiveness.
  
      (B) If the value of CV sub E exceeds 10 percent, then the test run (steps in 
  paragraphs (f)(2) through (f)(6) of this section) is unacceptable and must be 
  repeated.
  
      (7) Repeat steps in paragraphs (f)(1) through (f)(6) of this section for each 
  particle size 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(d)(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(d)(4).
  
      (3) Introduce aerosol. 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 as a detector:
  
      (A) Install a total filter on each leg of the divided flow apparatus.
  
      (B) Collect particles simultaneously through both legs at 16.7 L/min 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:
  
  Equation 32
  
  {SEE ILLUSTRATION(S) IN ORIGINAL DOCUMENT}
  
  where:
  
  i replicate number,
  
  M mass of material collected with the total filter; and
  
  Q candidate sampler volumetric flowrate.
  
      (D) Repeat steps in paragraphs (g)(4)(i)(A) through (g)(4)(i)(C) of this 
  section 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. {pg 
  38823}
  
      (B) Quantify the aerosol concentration of the primary particles in each leg of 
  the apparatus.
  
      (C) Repeat steps in paragraphs (g)(4)(ii)(A) through (g)(4)(ii)(B) of this 
  section until a minimum of three replicate measurements are performed.
  
      (iii) (A) Calculate the mean concentration and coefficient of variation as:
  
  Equation 33
  
  {SEE ILLUSTRATION(S) IN ORIGINAL DOCUMENT}
  
  Equation 34
  
  {SEE ILLUSTRATION(S) IN ORIGINAL DOCUMENT}
  
  where:
  
  i replicate number; and
  
  n number of replicates.
  
      (B) If the measured mean concentrations through the two legs do not agree 
  within 5 percent, then adjustments may be made in the setup, and this step must be 
  repeated.
  
      (5) Determine effectiveness. 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) Prepare the divided flow apparatus for particle collection. Install a total 
  filter into the bypass leg of the divided flow apparatus. Install the particle size 
  fractionator with a total filter placed immediately downstream of it into the other 
  leg.
  
      (B) Collect particles simultaneously through both legs at 16.7 L/min 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:
  
  Equation 35
  
  {SEE ILLUSTRATION(S) IN ORIGINAL DOCUMENT}
  
  Equation 36
  
  {SEE ILLUSTRATION(S) IN ORIGINAL DOCUMENT}
  
  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 C sub cand(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 C sub total(i).
  
      (iii) Calculate and record sampling effectiveness of the candidate sampler as:
  
  Equation 37
  
  {SEE ILLUSTRATION(S) IN ORIGINAL DOCUMENT}
  
  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 coefficient of variation for replicate measurements 
  of effectiveness. (i) Calculate and record the mean sampling effectiveness of the 
  candidate sampler as:
  
  Equation 38
  
  {SEE ILLUSTRATION(S) IN ORIGINAL DOCUMENT}
  
  where:
  
  i replicate number.
  
      (ii)(A) Calculate and record the coefficient of variation for the replicate 
  sampling effectiveness measurements of the candidate sampler as:
  
  Equation 39
  
  {SEE ILLUSTRATION(S) IN ORIGINAL DOCUMENT}
  
  where:
  
  i replicate number; and
  
  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 (g)(7) of this section).
  
      (8) Repeat steps in paragraphs (g)(1) through (g)(7) of this section for each 
  particle size 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 (as 
  described in paragraph (c)(3)(ii)) of this section will not require multiplet 
  correction.
  
      (2) Cutpoint determination. For each wind speed determine the sampler Dp sub 50 
  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(e)(3) through (e)(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 Dp sub 50 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 sampler's performance as a function of coarse aerosol 
  collection. The candidate sampler is exposed to a mass of coarse aerosol equivalent 
  to sampling a mass concentration of 150  mu g/m sup 3 over the time period that the 
  manufacturer has specified between periodic cleaning. After loading, the candidate 
  sampler is then evaluated by performing the test in Sec. 53.62 (full wind tunnel 
  test), Sec. 53.63 (wind tunnel inlet aspiration test), or Sec. 53.64 (static 
  fractionator test). If the acceptance criteria are met for this evaluation test, 
  then the candidate sampler is approved for multi- day sampling with the periodic 
  maintenance schedule as specified by the candidate method. For example, if the 
  candidate sampler passes the reevaluation tests following loading with an aerosol 
  mass equivalent to sampling a 150  mu g/m sup 3 aerosol continuously for 7 days, 
  then the sampler is approved for 7 day field operation before cleaning is required.
  
      (b) Technical definition. 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.
  
      (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 {pg 38824} 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 mu m ATD available from Powder Technology Incorporated 
  (Burnsville, MN). A fluidized bed aerosol generator, Wright dust feeder, or sonic 
  nozzle shall be used to efficiently deagglomerate the bulk test dust and transform 
  it into an aerosol cloud. 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.
  
      (4) Analytic balance. An analytical balance shall be used to determine the 
  weight of the total filter in the isokinetic sampler. The precision and accuracy of 
  this device shall be such that the relative measurement error is less than 5.0 
  percent for the difference between the initial and final weight of the total 
  filter. The identical analytic balance shall be used to perform both initial and 
  final weighing of the total filter.
  
      (d) Test procedure. (1) Calculate and record the target time weighted 
  concentration of Arizona road dust which is equivalent to exposing the sampler to 
  an environment of 150  mu g/m sup 3 over the time between cleaning specified by the 
  candidate sampler's operations manual as:
  
  Equation 40
  
  {SEE ILLUSTRATION(S) IN ORIGINAL DOCUMENT}
  
  where:
  
  t the number of hours specified by the candidate method prior to periodic cleaning.
  
      (2) Clean the candidate sampler. (i) Clean and dry the internal surfaces of the 
  candidate sampler.
  
      (ii) Prepare the internal surfaces in strict accordance with the operating 
  manual referred to in section 7.4.18 of 40 CFR part 50, Appendix L.
  
      (3) Determine the preweight of the filter that shall be used in the isokinetic 
  sampler. Record this value as InitWt.
  
      (4) Install the candidate sampler's inlet and the isokinetic sampler within the 
  test chamber or wind tunnel.
  
      (5) Generate a dust cloud. (i) Generate a dust cloud composed of Arizona test 
  dust.
  
      (ii) Introduce the dust cloud into the chamber.
  
      (iii) Allow sufficient time for the particle concentration to become steady 
  within the chamber.
  
      (6) Sample aerosol with a total filter and the candidate sampler. (i) Sample 
  the aerosol for a time sufficient to produce an equivalent TWC equal to that of the 
  target TWC +/- 15 percent.
  
      (ii) Record the sampling time as t.
  
      (7) Determine the time weighted concentration. (i) Determine the postweight of 
  the isokinetic sampler's total filter.
  
      (ii) Record this value as FinalWt.
  
      (iii) Calculate and record the TWC as:
  
  Equation 41
  
  {SEE ILLUSTRATION(S) IN ORIGINAL DOCUMENT}
  
  where:
  
  Q the flow rate of the candidate method.
  
      (iv) If the value of TWC deviates from the target TWC +/- 15 percent, then the 
  loaded mass is unacceptable and the entire test procedure must be repeated.
  
      (8) Determine the candidate sampler's effectiveness after 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 inlet deviation in Sec. 53.60(e)(1) may 
  opt to perform the test in Sec. 53.63 (inlet aspiration test) in lieu of the 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 results. If the candidate sampler meets the acceptance criteria for 
  the evaluation test performed in paragraph (d)(8) of this section, then the 
  candidate sampler passes this test with the stipulation that the sampling train be 
  cleaned as directed by and as frequently as that specified by the candidate 
  sampler's operations manual.
  
   Sec. 53.66 -- Test procedure: Volatility test.
  
      (a) Overview. This test is designed to ensure that the candidate method's 
  losses due to volatility when sampling semi-volatile ambient aerosol will be 
  comparable to that of a federal reference method sampler. This is accomplished by 
  challenging the candidate sampler with a polydisperse, semi-volatile liquid aerosol 
  in three distinct phases. During phase A of this test, the aerosol is elevated to a 
  steady- state, test-specified mass concentration and the sample filters are 
  conditioned and preweighed. In phase B, the challenge aerosol is simultaneously 
  sampled by the candidate method sampler and a reference method sampler onto the 
  preweighed filters for a specified time period. In phase C (the blow-off phase), 
  aerosol and aerosol- vapor free air is sampled by the samplers for an additional 
  time period to partially volatilize the aerosol on the filters. The candidate 
  sampler passes the volatility test if the acceptance criteria presented in Table F-
  1 of this subpart are met or exceeded.
  
      (b) Technical definitions. (1) Residual mass (RM) is defined as the weight of 
  the filter after the blow-off phase subtracted from the initial weight of the 
  filter.
  
      (2) Corrected residual mass (CRM) is defined as the residual mass of the filter 
  from the candidate sampler multiplied by the ratio of the reference method flow 
  rate to the candidate method flow rate.
  
      (c) Facilities and equipment required-(1) Environmental chamber. Because the 
  nature of a volatile aerosol is greatly dependent upon environmental conditions, 
  all phases of this test shall be conducted at a temperature of 22.0 +/- 0.5 deg C 
  and a relative humidity of 40 +/- 3 percent. For this reason, it is strongly 
  advised that all weighing and experimental apparatus be housed in an environmental 
  chamber capable of this level of control.
  
      (2) Aerosol generator. The aerosol generator shall be a pressure nebulizer 
  operated at 20 to 30 psig (140 to 207 kPa) to produce a polydisperse, semi-voltile 
  aerosol with a mass median diameter larger than 1 mu m and smaller than 2.5 mu m. 
  The nebulized liquid shall be A.C.S. reagent grade glycerol (C sub 3H sub 8O sub , 
  FW 92.09, CAS 56-81-5) of 99.5 percent minimum purity. For the purpose of this test 
  the accepted mass median diameter is predicated on the stable aerosol inside the 
  internal chamber and not on the aerosol emerging from the nebulizer nozzle. Aerosol 
  monitoring and its stability are described in (c)(3) and (c)(4) of this section.
  
      (3) Aerosol monitoring equipment. The evaporation and condensation dynamics of 
  a volatile aerosol is greatly dependent upon the vapor pressure of the volatile 
  component in the carrier gas. The size of an aerosol becomes fixed only when an 
  equilibrium is established between the aerosol and the surrounding vapor; 
  therefore, aerosol {pg 38825} size measurement shall be used as a surrogate measure 
  of this equilibrium. A suitable instrument with a range of 0.3 to 10 mu m, an 
  accuracy of 0.5 mu m, and a resolution of 0.2 mu m (e.g., an optical particle 
  sizer, or a time-of-flight instrument) shall be used for this purpose. The 
  parameter monitored for stability shall be the mass median instrument measured 
  diameter (i.e. optical diameter if an optical particle counter is used). A stable 
  aerosol shall be defined as an aerosol with a mass median diameter that has changed 
  less than 0.25 mu m over a 4 hour time period.
  
      (4) Internal chamber. The time required to achieve a stable aerosol depends 
  upon the time during which the aerosol is resident with the surrounding air. This 
  is a function of the internal volume of the aerosol transport system and may be 
  facilitated by recirculating the challenge aerosol. A chamber with a volume of 0.5 
  m sup 3 and a recirculating loop (airflow of approximately 500 cfm) is recommended 
  for this purpose. In addition, a baffle is recommended to dissipate the jet of air 
  that the recirculating loop can create. Furthermore, a HEPA filtered hole in the 
  wall of the chamber is suggested to allow makeup air to enter the chamber or excess 
  air to exit the chamber to maintain a system flow balance. The concentration inside 
  the chamber shall be maintained at 1 mg/m sup 3 +/- 20 percent to obtain consistent 
  and significant filter loading.
  
      (5) Aerosol sampling manifold. A manifold shall be used to extract the aerosol 
  from the area in which it is equilibrated and transport it to the candidate method 
  sampler, the reference method sampler, and the aerosol monitor. The losses in each 
  leg of the manifold shall be equivalent such that the three devices will be exposed 
  to an identical aerosol.
  
      (6) Chamber air temperature recorders. Minimum range 15-25 deg C, certified 
  accuracy to within 0.2 deg C, resolution of 0.1 deg C. Measurement shall be made at 
  the intake to the sampling manifold and adjacent to the weighing location.
  
      (7) Chamber air relative humidity recorders. Minimum range 30 - 50 percent, 
  certified accuracy to within 1 percent, resolution of 0.5 percent. Measurement 
  shall be made at the intake to the sampling manifold and adjacent to the weighing 
  location.
  
      (8) Clean air generation system. A source of aerosol and aerosol-vapor free air 
  is required for phase C of this test. This clean air shall be produced by filtering 
  air through an absolute (HEPA) filter.
  
      (9) Balance. Minimum range 0 - 200 mg, certified accuracy to within 10 mu g, 
  resolution of 1 mu g.
  
      (d) Additional filter handling conditions. (1) 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 dynamic conditioning 
  and phase C.
  
      (2) Dynamic conditioning of filters. Total dynamic conditioning is required 
  prior to the initial weight determined in phase A. Dynamic conditioning refers to 
  pulling clean air from the clean air generation system through the filters. 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 +/- 3 mu g.
  
      (3) 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.
  
      (e) Test procedure-(1) Phase A - Preliminary steps. (i) Generate a polydisperse 
  glycerol test aerosol.
  
      (ii) Introduce the aerosol into the transport system.
  
      (iii) Monitor the aerosol size and concentration until stability and level have 
  been achieved.
  
      (iv) Condition the candidate method sampler and reference method sampler 
  filters until total dynamic conditioning is achieved as specified in paragraph 
  (d)(2) of this section.
  
      (v) Record the dynamically conditioned weight as InitWt sub c and InitWt sub r 
  where c is the candidate method sampler and r is the reference method sampler.
  
      (2) Phase B - Aerosol loading. (i) Install the dynamically conditioned filters 
  into the appropriate samplers.
  
      (ii) Attach the samplers to the manifold.
  
      (iii) Operate the candidate and the reference samplers such that they 
  simultaneously sample the test aerosol for 30 minutes.
  
      (3) Phase C - Blow-off. (i) Alter the intake of the samplers to sample air from 
  the clean air generation system.
  
      (ii) Sample clean air for one of the required blow-off time durations (1, 2, 3, 
  and 4 hours).
  
      (iii) Remove the filters from the samplers.
  
      (iv) Weigh the filters immediately and record this weight, FinalWt sub c and 
  FinalWt sub r, where c is the candidate method sampler and r is the reference 
  method sampler.
  
      (v) Calculate the residual mass for the reference method sampler:
  
  Equation 41a
  
  {SEE ILLUSTRATION(S) IN ORIGINAL DOCUMENT}
  
  where:
  
  i repetition number; and
  
  j blow-off time period.
  
      (vi) Calculate the corrected residual mass for the candidate method sampler as:
  
  Equation 41b
  
  {SEE ILLUSTRATION(S) IN ORIGINAL DOCUMENT}
  
  where:
  
  i repetition number;
  
  j blow-off time period;
  
  Q sub c candidate method sampler flow rate, and
  
  Q sub r  reference method sampler flow rate.
  
      (4) Repeat steps in paragraph (e)(1) through (e)(3) of this section until three 
  repetitions have been completed for each of the required blow-off time durations 
  (1, 2, 3, and 4 hours).
  
      (f) Calculations and analysis. (1) Perform a linear regression with the 
  candidate method CRM as the dependent variable and the reference method RM as the 
  independent variable.
  
      (2) Determine the following regression parameters: slope, intercept, and 
  correlation coefficient (r).
  
      (g) Test results. The candidate method passes the volatility test if the 
  regression parameters meet the acceptance criteria specified in Table F-1 of this 
  subpart.
  
  Tables to Subpart F of Part 53 {pg 38826}
  
  
   Table F-1.-Performance Specifications for PM sub 2.5  Class II
   Equivalent Samplers
   
   Performance Test      Specifications        Acceptance Criteria
   
   Sec. 53.62 Full Wind  Solid VOAG produced   Dp sub 50   2.5 mu m
   Tunnel Evaluation     aerosol at 2 km/hr    +/- 0.2 mu m;
                         and 24 km/hr          Numerical Analysis
                                               Results: 95% >R sub
                                               c>105%
   Sec. 53.63 Wind       Liquid VOAG produced  Relative Aspiration:
   Tunnel Inlet          aerosol at 2 km/hr    95% >A>105%
   Aspiration Test       and 24 km/hr
   Sec. 53.64 Static     Evaluation of the     Dp sub 50   2.5 mu m
   Fractionator Test     fractionator under    +/- 0.2 mu m;
                         static conditions     Numerical Analysis
                                               Results: 95% >R sub
                                               c>105%
   Sec. 53.65 Loading    Loading of the clean  Acceptance criteria
   Test                  candidate under       as specified in the
                         laboratory            post-loading
                         conditions            evaluation test
                                               (Sec. 53.62, Sec.
                                               53.63, or Sec.
                                               53.64)
   Sec. 53.66            Polydisperse liquid   Regression
   Volatility Test       aerosol produced by   Parameters Slope   1
                         air nebulization of   +/- 0.1, Intercept  
                         A.C.S. reagent grade  0 +/- 0.15 r -  0.97
                         glycerol, 99.5%
                         minimum purity
   
   
  
   Table F-2.-Particle Sizes and Wind Speeds for Full Wind Tunnel
   Test, Wind Tunnel Inlet Aspiration Test, and Static Chamber Test
   
   Primary Partical   Full Wind Tunnel Test  Inlet Aspiration Test
   Mean Size fn a
   ( mu m)
                      2 km/hr     24 km/hr   2 km/hr    24 km/hr
   
   1.5 +/- 0.25       S           S
   2.0 +/- 0.25       S           S
   2.2 +/- 0.25       S           S
   2.5 +/- 0.25       S           S
   2.8 +/- 0.25       S           S
   3.0 +/- 0.25                              L          L
   3.5 +/- 0.25       S           S
   4.0 +/- 0.5        S           S
   Polydisperse
   Glycerol Aerosol
   
   Primary Partical      Static Fractionator   Volatility Test
   Mean Size fn a  ( mu  Test
   m)
   
   1.5 +/- 0.25          S
   2.0 +/- 0.25          S
   2.2 +/- 0.25          S
   2.5 +/- 0.25          S
   2.8 +/- 0.25          S
   3.0 +/- 0.25
   3.5 +/- 0.25          S
   4.0 +/- 0.5           S
   Polydisperse                                L
   Glycerol Aerosol
   
   fn  a Aerodynamic diameter.
   
   fn S Solid particles.
   
   fn L Liquid particles.
   
   
  
   Table F-3.-Critical Parameters of Idealized Ambient Particle Size
   Distributions
   
   Idealized                     Fine Particle Mode
   Distribution
                   MMD ( mu m)     Geo. Std. Dev.  Conc. ( mu g/m
                                                   sup 3 )
   
   Coarse          0.50            2               12.0
   "Typical"       0.50            2               33.3
   Fine            0.85            2               85.0
   
   Idealized                    Coarse Particle Mode
   Distribution
                   MMD ( mu m)     Geo. Std. Dev.  Conc. ( mu g/m
                                                   sup 3 )
   
   Coarse          10              2               88.0
   "Typical"       10              2               66.7
   Fine            15              2               15.0
   
   Idealized             PM sub 2.5/PM sub 10  FRM Sampler Expected
   Distribution          Ratio                 Mass Conc. ( mu g/m
                                               sup 3 )
   
   Coarse                0.27                  13.814
   "Typical"             0.55                  34.284
   Fine                  0.94                  78.539
   
   
  
   Table F- 4.- Estimated Mass Concentration Measurement of PM sub
   2.5  for Idealized Coarse Aerosol Size Distribution
   
   Particle                         Test Sampler
   Aerodynamic
   Diameter ( mu
   m)
                   Fractional      Interval Mass   Estimated Mass
                   Sampling        Concentration   Concentration
                   Effectiveness   ( mu  g/m sup   Measurement (
                                   3 )             mu  g/m sup 3
                                                   )
   (1)             (2)             (3)             (4)
   <0.500          1.000           6.001
   0.625                           2.129
   0.750                           0.982
   0.875                           0.730
   1.000                           0.551
   1.125                           0.428
   1.250                           0.346
   1.375                           0.294
   1.500                           0.264
   1.675                           0.251
   1.750                           0.250
   1.875                           0.258
   2.000                           0.272
   2.125                           0.292
   2.250                           0.314
   2.375                           0.339
   2.500                           0.366
   2.625                           0.394
   2.750                           0.422
   2.875                           0.449
   3.000                           0.477
   3.125                           0.504
   3.250                           0.530
   3.375                           0.555
   3.500                           0.579
   3.625                           0.602
   3.750                           0.624
   3.875                           0.644
   4.000                           0.663
   4.125                           0.681
   4.250                           0.697
   4.375                           0.712
   4.500                           0.726
   4.625                           0.738
   4.750                           0.750
   4.875                           0.760
   5.000                           0.769
   5.125                           0.777
   5.250                           0.783
   5.375                           0.789
   5.500                           0.794
   5.625                           0.798
   5.75                            0.801
                                   C sub sam(exp)
                                    
   
   Particle                        Ideal Sampler
   Aerodynamic
   Diameter ( mu
   m)
                   Fractional      Interval Mass   Estimated Mass
                   Sampling        Concentration   Concentration
                   Effectiveness   ( mu  g/m sup   Measurement (
                                   3 )             mu  g/m sup 3
                                                   )
   
   (1)             (5)             (6)             (7)
   <0.500          1.000           6.001           6.001
   0.625           0.999           2.129           2.127
   0.750           0.998           0.982           0.980
   0.875           0.997           0.730           0.728
   1.000           0.995           0.551           0.548
   1.125           0.991           0.428           0.424
   1.250           0.987           0.346           0.342
   1.375           0.980           0.294           0.288
   1.500           0.969           0.264           0.256
   1.675           0.954           0.251           0.239
   1.750           0.932           0.250           0.233
   1.875           0.899           0.258           0.232
   2.000           0.854           0.272           0.232
   2.125           0.791           0.292           0.231
   2.250           0.707           0.314           0.222
   2.375           0.602           0.339           0.204
   2.500           0.480           0.366           0.176
   2.625           0.351           0.394           0.138
   2.750           0.230           0.422           0.097
   2.875           0.133           0.449           0.060
   3.000           0.067           0.477           0.032
   3.125           0.030           0.504           0.015
   3.250           0.012           0.530           0.006
   3.375           0.004           0.555           0.002
   3.500           0.001           0.579           0.001
   3.625           0.000000        0.602           0.000000
   3.750           0.000000        0.624           0.000000
   3.875           0.000000        0.644           0.000000
   4.000           0.000000        0.663           0.000000
   4.125           0.000000        0.681           0.000000
   4.250           0.000000        0.697           0.000000
   4.375           0.000000        0.712           0.000000
   4.500           0.000000        0.726           0.000000
   4.625           0.000000        0.738           0.000000
   4.750           0.000000        0.750           0.000000
   4.875           0.000000        0.760           0.000000
   5.000           0.000000        0.769           0.000000
   5.125           0.000000        0.777           0.000000
   5.250           0.000000        0.783           0.000000
   5.375           0.000000        0.789           0.000000
   5.500           0.000000        0.794           0.000000
   5.625           0.000000        0.798           0.000000
   5.75            0.000000        0.801           0.000000
                                   C sub           13.814
                                   ideal(exp)  
   
   
   {pg 38828}
  
  
   Table F -5.- Estimated Mass Concentration Measurement of PM sub
   2.5  for Idealized "Typical" Coarse Aerosol Size Distribution
   
   Particle                         Test Sampler
   Aerodynamic
   Diameter ( mu
   m)
                   Fractional      Interval Mass   Estimated Mass
                   Sampling        Concentration   Concentration
                   Effectiveness   ( mu  g/m sup   Measurement (
                                   3 )             mu  g/m sup 3
                                                   )
   
   (1)             (2)             (3)             (4)
   <0.500          1.000           16.651
   0.625                           5.899
   0.750                           2.708
   0.875                           1.996
   1.000                           1.478
   1.125                           1.108
   1.250                           0.846
   1.375                           0.661
   1.500                           0.532
   1.675                           0.444
   1.750                           0.384
   1.875                           0.347
   2.000                           0.325
   2.125                           0.314
   2.250                           0.312
   2.375                           0.316
   2.500                           0.325
   2.625                           0.336
   2.750                           0.350
   2.875                           0.366
   3.000                           0.382
   3.125                           0.399
   3.250                           0.416
   3.375                           0.432
   3.500                           0.449
   3.625                           0.464
   3.750                           0.480
   3.875                           0.494
   4.000                           0.507
   4.125                           0.520
   4.250
   4.375
   4.500
   4.625
   4.750
   4.875
   5.000
   5.125
   5.250
   5.375
   5.500
   5.625
   5.75
                                   C sub sam(exp)
                                    
   
   Particle                        Ideal Sampler
   Aerodynamic
   Diameter ( mu
   m)
                   Fractional      Interval Mass   Estimated Mass
                   Sampling        Concentration   Concentration
                   Effectiveness   ( mu  g/m sup   Measurement (
                                   3 )             mu  g/m sup 3
                                                   )
   
   (1)             (5)             (6)             (7)
   <0.500          1.000           16.651          16.651
   0.625           0.999           5.899           5.893
   0.750           0.998           2.708           2.703
   0.875           0.997           1.996           1.990
   1.000           0.995           1.478           1.471
   1.125           0.991           1.108           1.098
   1.250           0.987           0.846           0.835
   1.375           0.980           0.661           0.648
   1.500           0.969           0.532           0.516
   1.675           0.954           0.444           0.424
   1.750           0.932           0.384           0.358
   1.875           0.899           0.347           0.312
   2.000           0.854           0.325           0.277
   2.125           0.791           0.314           0.248
   2.250           0.707           0.312           0.221
   2.375           0.602           0.316           0.190
   2.500           0.480           0.325           0.156
   2.625           0.351           0.336           0.118
   2.750           0.230           0.350           0.081
   2.875           0.133           0.366           0.049
   3.000           0.067           0.382           0.026
   3.125           0.030           0.399           0.012
   3.250           0.012           0.416           0.005
   3.375           0.004           0.432           0.002
   3.500           0.001           0.449           0.000000
   3.625           0.000000        0.464           0.000000
   3.750           0.000000        0.480           0.000000
   3.875           0.000000        0.494           0.000000
   4.000           0.000000        0.507           0.000000
   4.125           0.000000        0.520           0.000000
   4.250           0.000000        0.532           0.000000
   4.375           0.000000        0.543           0.000000
   4.500           0.000000        0.553           0.000000
   4.625           0.000000        0.562           0.000000
   4.750           0.000000        0.570           0.000000
   4.875           0.000000        0.577           0.000000
   5.000           0.000000        0.584           0.000000
   5.125           0.000000        0.590           0.000000
   5.250           0.000000        0.595           0.000000
   5.375           0.000000        0.599           0.000000
   5.500           0.000000        0.603           0.000000
   5.625           0.000000        0.605           0.000000
   5.75            0.000000        0.608           0.000000
                                   C sub           34.284
                                   ideal(exp)  
   
   
   {pg 38829}
  
  
   Table F -6.- Estimated Mass Concentration Measurement of PM sub
   2.5  for Idealized Fine Aerosol Size Distribution
   
   Particle                         Test Sampler
   Aerodynamic
   Diameter ( mu
   m)
                   Fractional      Interval Mass   Estimated Mass
                   Sampling        Concentration   Concentration
                   Effectiveness   ( mu  g/m sup   Measurement (
                                   3 )             mu  g/m sup 3
                                                   )
   
   (1)             (2)             (3)             (4)
   <0.500          1.000           18.868
   0.625                           13.412
   0.750                           8.014
   0.875                           6.984
   1.000                           5.954
   1.125                           5.015
   1.250                           4.197
   1.375                           3.503
   1.500                           2.921
   1.675                           2.438
   1.750                           2.039
   1.875                           1.709
   2.000                           1.437
   2.125                           1.212
   2.250                           1.026
   2.375                           0.873
   2.500                           0.745
   2.625                           0.638
   2.750                           0.550
   2.875                           0.476
   3.000                           0.414
   3.125                           0.362
   3.250                           0.319
   3.375                           0.282
   3.500                           0.252
   3.625                           0.226
   3.750                           0.204
   3.875                           0.185
   4.000                           0.170
   4.125                           0.157
   4.250                           0.146
   4.375                           0.136
   4.500                           0.129
   4.625                           0.122
   4.750                           0.117
   4.875                           0.112
   5.000                           0.108
   5.125                           0.105
   5.250                           0.102
   5.375                           0.100
   5.500                           0.098
   5.625                           0.097
   5.75                            0.096
                                   C sub sam(exp)
                                    
   
   Particle                        Ideal Sampler
   Aerodynamic
   Diameter ( mu
   m)
                   Fractional      Interval Mass   Estimated Mass
                   Sampling        Concentration   Concentration
                   Effectiveness   ( mu  g/m sup   Measurement (
                                   3 )             mu  g/m sup 3
                                                   )
   
   (1)             (5)             (6)             (7)
   <0.500          1.000           18.868          18.868
   0.625           0.999           13.412          13.399
   0.750           0.998           8.014           7.998
   0.875           0.997           6.984           6.963
   1.000           0.995           5.954           5.924
   1.125           0.991           5.015           4.970
   1.250           0.987           4.197           4.142
   1.375           0.980           3.503           3.433
   1.500           0.969           2.921           2.830
   1.675           0.954           2.438           2.326
   1.750           0.932           2.039           1.900
   1.875           0.899           1.709           1.536
   2.000           0.854           1.437           1.227
   2.125           0.791           1.212           0.959
   2.250           0.707           1.026           0.725
   2.375           0.602           0.873           0.526
   2.500           0.480           0.745           0.358
   2.625           0.351           0.638           0.224
   2.750           0.230           0.550           0.127
   2.875           0.133           0.476           0.063
   3.000           0.067           0.414           0.028
   3.125           0.030           0.362           0.011
   3.250           0.012           0.319           0.004
   3.375           0.004           0.282           0.001
   3.500           0.001           0.252           0.000000
   3.625           0.000000        0.226           0.000000
   3.750           0.000000        0.204           0.000000
   3.875           0.000000        0.185           0.000000
   4.000           0.000000        0.170           0.000000
   4.125           0.000000        0.157           0.000000
   4.250           0.000000        0.146           0.000000
   4.375           0.000000        0.136           0.000000
   4.500           0.000000        0.129           0.000000
   4.625           0.000000        0.122           0.000000
   4.750           0.000000        0.117           0.000000
   4.875           0.000000        0.112           0.000000
   5.000           0.000000        0.108           0.000000
   5.125           0.000000        0.105           0.000000
   5.250           0.000000        0.102           0.000000
   5.375           0.000000        0.100           0.000000
   5.500           0.000000        0.098           0.000000
   5.625           0.000000        0.097           0.000000
   5.75            0.000000        0.096           0.000000
                                   C sub           78.539
                                   ideal(exp)  
   
   
   {pg 38830}
  
  Figures to Subpart F of Part 53
  
  Figure E-1.- Designation Testing Checklist
  
  DESIGNATION TESTING CHECKLIST FOR CLASS II
  
   X X X
  
  Auditee Auditor signature Date
  
  
   Compliance Status: Y   Yes N   No NA   Not
   applicable/Not available
   Verification          Verified by Direct
                         Observation of Process or
                         of Documented Evidence:
                         Performance, Design or
                         Application Spec.
                         Corresponding to Sections
                         of 40 CFR Part 53, Subparts
                         E and F
   
      Compliance Status: Y   Yes N   No NA   Not     Verification
               applicable/Not available              Comments
                                                     (Includes
                                                     documentation
                                                     of who, what,
                                                     where, when,
                                                     why) (Doc.   ,
                                                     Rev.   , Rev.
                                                     Date)
   
   N                                     NA
   Subpart E: Performance Specification
   Tests
   Evaluation completed according to
   Subpart E Sec. 53.50 to Sec. 53.56
   Subpart E: Class I Sequential Tests
   Class II samplers that are also Class
   I (sequentialized) have passed the
   tests in Sec. 53.57
   Subpart F: Performance Spec/Test
   Evaluation of Physical
   Characteristics of Clean Sampler -
   One of these tests must be performed:
   Sec. 53.62 - Full Wind Tunnel Sec.
   53.63 - Inlet Aspiration Sec. 53.64 -
   Static Fractionator
   Evaluation of Physical
   Characteristics of Loaded Sampler
   Sec. 53.65 Loading Test One of the
   following tests must be performed for
   evaluation after loading: Sec. 53.62,
   Sec. 53.63, Sec. 53.64
   Evaluation of the Volatile
   Characteristics of the Class II
   Sampler Sec. 53.66
   
   
  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).
  
      (3) Society of Automotive Engineers Aerospace Material Specification (SAE AMS) 
  2404C, Electroless Nickel Planting, SAE, 400 Commonwealth Drive, Warrendale PA-
  15096, Revised 7-1-84, pp. 1-6.
  
  PART 58- AMENDED 
  
      2. In part 58:
  
      a. The authority citation for part 58 continues to read as follows:
  
      Authority: 42 U.S.C. 7410, 7601(a), 7613, 7619.
  
      b. Section 58.1 is amended by removing the existing alphabetic paragraph 
  designations, by alphabetizing the existing definitions, by revising the definition 
  Traceable and by adding in alphabetical order the following definitions to read as 
  follows:
  
   Sec. 58.1 -- Definitions.
  
      * * * * *
  
      Annual State air monitoring report 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.
  
      * * * * *
  
      Community Monitoring Zone (CMZ) means an optional averaging area with 
  established, well defined boundaries, such as county or census block, within a MPA 
  that has relatively uniform concentrations of annual PM sub 2.5 as defined by 
  Appendix D of this part. Two or more core SLAMS and other monitors within a CMZ 
  that meet certain requirements as set forth in Appendix D of this part may be 
  averaged for making comparisons to the annual PM sub 2.5 NAAQS.
  
      Consolidated Metropolitan Statistical Area (CMSA) 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 
  CMSA.
  
      Core PM sub 2.5 SLAMS means community-oriented monitoring sites representative 
  of community-wide exposures that are the basic component sites of the PM sub 2.5 
  SLAMS regulatory network. Core PM sub 2.5 SLAMS include community-oriented {pg 
  38831} SLAMS monitors, and sites collocated at PAMS.
  
      * * * * *
  
      Correlated acceptable continuous (CAC) PM analyzer means an optional fine 
  particulate matter analyzer that can be used to supplement a PM sub 2.5 reference 
  or equivalent sampler, in accordance with the provisions of Sec. 58.13(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 part 53 of this chapter; 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 of 
  this chapter.
  
      * * * * *
  
      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 that have a high 
  degree of economic and social integration with that nucleus.
  
      * * * * *
  
      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 PM sub 2.5. MPAs may cross State boundaries, such as the Philadelphia 
  PA-NJ MSA, and be further subdivided into community monitoring zones. MPAs are 
  generally oriented toward areas with populations greater than 200,000, but for 
  convenience, those portions of a State that are not associated with MSAs can be 
  considered as a single MPA. MPAs must be defined, where applicable, in a State PM 
  monitoring network description.
  
      * * * * *
  
      Particulate matter monitoring network description, required by Sec. 58.20(f), 
  means a detailed plan, prepared by control agencies and submitted to EPA for 
  approval, that describes their PM sub 2.5 and PM sub 10 air quality surveillance 
  network.
  
      * * * * *
  
      PM sub 2.5 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 40 
  CFR part 50, Appendix L, and designated in accordance with part 53 of this chapter 
  or by an equivalent method designated in accordance with part 53 of this chapter.
  
      * * * * *
  
      Population-oriented monitoring (or sites) applies to residential areas, 
  commercial areas, recreational areas, industrial areas, and other areas where a 
  substantial number of people may spend a significant fraction of their day.
  
      Primary Metropolitan Statistical Area (PMSA) is a separate component of a 
  consolidated metropolitan statistical area. For the purposes of this part, PMSA is 
  used interchangeably with MSA.
  
      * * * * *
  
      Reference method means a method of sampling and analyzing the ambient air for 
  an air pollutant that will be 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 of 
  this chapter.
  
      * * * * *
  
      Special Purpose Monitor (SPM) is a generic term used for all monitors other 
  than SLAMS, NAMS, PAMS, and PSD monitors included in an agency's monitoring network 
  for monitors used in a special study whose data are officially reported to EPA.
  
      * * * * *
  
      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).
  
      * * * * *
  
      c. Section 58.13 is amended by revising paragraphs (b) and (d) and adding new 
  paragraphs (e) and (f) to read as follows:
  
   Sec. 58.13 -- Operating schedule.
  
      * * * * *
  
      (b) For manual methods (excluding PM sub 10 samplers, PM sub 2.5 samplers, and 
  PAMS VOC samplers), at least one 24-hour sample must be obtained every sixth day 
  except during periods or seasons exempted by the Regional Administrator.
  
      * * * * *
  
      (d) For PM sub 10 samplers--a 24-hour sample must be taken a minimum of every 
  third day.
  
      (e) For PM sub 2.5 samplers, a 24-hour sample is required everyday for certain 
  core SLAMS, including certain PAMS, as described in section 2.8.1.3 of Appendix D 
  of this part, except during seasons or periods of low PM sub 2.5 as otherwise 
  exempted by the Regional Administrator. A waiver of the everyday sampling schedule 
  for SLAMS may be granted by the Regional Administrator or designee, and for NAMS by 
  the Administrator or designee, for 1 calendar year from the time a PM sub 2.5 
  sequential sampler (FRM or Class I equivalent) has been approved by EPA. A 24- hour 
  sample must be taken a minimum of every third day for all other SLAMS, including 
  NAMS, as described in section 2.8.1.3 of Appendix D of this part, except when 
  exempted by the Regional Administrator in accordance with forthcoming EPA guidance. 
  During periods for which exemptions to every third day or every day sampling are 
  allowed for core PM sub 2.5 SLAMS, a minimum frequency of one in 6-day sampling is 
  still required. However, alternative sampling frequencies are allowed for SLAMS 
  sites that are principally intended for comparisons to the 24-hour NAAQS. Such 
  modifications must be approved by the Regional Administrator.
  
      (f) Alternatives to everyday sampling at sites with correlated acceptable 
  continuous analyzers. (1) Certain PM sub 2.5 core SLAMS sites located in monitoring 
  planning areas (as described in section 2.8 of Appendix D of this part) are 
  required to sample every day with a reference or equivalent method operating in 
  accordance with part 53 of this chapter and section 2 of Appendix C of 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 it is 
  collocated with an acceptable continuous fine particulate 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 approved by the Regional Administrator. 
  Unless the continuous fine particulate analyzer satisfies the requirements of 
  section 2 of Appendix C of this part, however, the data derived from the correlated 
  acceptable continuous monitor are not eligible for direct comparisons to the NAAQS 
  in accordance with part 50 of this chapter. {pg 38832}
  
      (2) A Metropolitan Statistical Area (MSA) (or primary metropolitan statistical 
  area) with greater than 1 million population and high concentrations of PM sub 2.5 
  (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 2 complete years.
  
      (4) 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.
  
      d. Section 58.14 is revised to read 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) Based on the need, in transitioning to a PM sub 2.5 standard that newly 
  addresses the ambient impacts of fine particles, to encourage a sufficiently 
  extensive geographical deployment of PM sub 2.5 monitors and thus hasten the 
  development of an adequate PM sub 2.5 ambient air quality monitoring 
  infrastructure, PM sub 2.5 NAAQS violation determinations shall not be exclusively 
  made based on data produced at a population-oriented SPM site during the first 2 
  complete calendar years of its operation. However, a notice of NAAQS violations 
  resulting from population-oriented SPMs shall be reported to EPA in the State's 
  annual monitoring report and be considered by the State in the design of its 
  overall SLAMS network; these population-oriented SPMs should be considered to 
  become a 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.
  
      e. Section 58.20 is amended by revising the section heading, paragraph (d), and 
  the introductory text of paragraph (e), by designating the flush text at the end of 
  the section as paragraph (i) and amending the third sentence by removing the words 
  "(a) through (f)" and adding in their place, "(a) through (h)", by redesignating 
  paragraph (f) as paragraph (h), and adding new paragraphs (f) and (g) to read as 
  follows:
  
   Sec. 58.20 -- Air quality surveillance: plan content.
  
      * * * * *
  
      (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 
  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 that are necessary. For PM sub 2.5, the review must identify needed 
  changes to core SLAMS, monitoring planning areas, the chosen community monitoring 
  approach including optional community monitoring zones, SLAMS, or SPMs.
  
      (e) Provide for having a SLAMS network description available for public 
  inspection and submission to the Administrator upon request. The network 
  description must be available at the time of plan revision submittal and must 
  contain the following information for each SLAMS:
  
      * * * * *
  
      (f) Provide for having a PM monitoring network description available for public 
  inspection which must provide for monitoring planning areas, and the community 
  monitoring approach involving core monitors and optional community monitoring zones 
  for PM sub 2.5. The PM monitoring network description for PM sub 10 and PM sub 2.5 
  must be submitted to the Regional Administrator for approval by July 1, 1998, and 
  must contain the following information for each PM SLAMS and PM sub 2.5 SPM:
  
      (1) The AIRS site identification form for existing stations.
  
      (2) The proposed location for scheduled stations.
  
      (3) The sampling and analysis method.
  
      (4) The operating schedule.
  
      (5) The monitoring objective, spatial scale of representativeness, and 
  additionally for PM sub 2.5, the monitoring planning area, optional community 
  monitoring zone, and the site code designation to identify which site will be 
  identified as core SLAMS; and SLAMS or population-oriented SPMs, if any, that are 
  microscale or middle scale in their representativeness as defined in Appendix D of 
  this part.
  
      (6) A schedule for:
  
      (i) Locating, placing into operation, and making available the AIRS site 
  identification form for each SLAMS which is not located and operating at the time 
  of plan revision submittal.
  
      (ii) Implementing quality assurance procedures of Appendix A of this part for 
  each SLAMS for which such procedures are not implemented at the time of plan 
  revision submittal.
  
      (iii) Resiting each SLAMS which does not meet the requirements of Appendix E of 
  this part at the time of plan revision submittal.
  
      (g) Provide for having a list of all PM sub 2.5 monitoring locations including 
  SLAMS, NAMS, PAMS and population-oriented SPMs, that are included in the State's PM 
  monitoring network description and are intended for comparison to the NAAQS, 
  available for public inspection.
  
      * * * * *
  
      f. 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.
  
      With the exception of the PM sub 10 monitoring networks that shall be in place 
  by March 16, 1998 and with the exception of the PM sub 2.5 monitoring networks as 
  described in paragraph (c) of this section:
  
      * * * * *
  
      (c) Each PM sub 2.5 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 of this part, and be located as 
  described on the station's AIRS site identification form, according to the 
  following schedule:
  
      (1) Within 1 year after September 16, 1997, at least one required core PM sub 
  2.5 SLAMS site in each MSA with population greater than 500,000, plus one site in 
  each PAMS area, (plus at least two additional SLAMS sites per State) must be in 
  operation.
  
      (2) Within 2 years after September 16, 1997, all other required SLAMS, {pg 
  38833} including all required core SLAMS, required regional background and regional 
  transport SLAMS, continuous PM monitors in areas with greater than 1 million 
  population, and all additional required PM sub 2.5 SLAMS must be in operation.
  
      (3) Within 3 years after September 16, 1997, all additional sites (e.g., sites 
  classified as SLAMS/SPM to complete the mature network) must be in operation.
  
      g. Section 58.26 is amended by revising the section heading and the 
  introductory text of paragraph (b), and adding 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 monitoring and data-(1) The State shall submit a summary to the 
  appropriate Regional Office (for SLAMS) or Administrator (through the Regional 
  Office) (for NAMS) that details proposed changes to the PM Monitoring Network 
  Description and to be in accordance with the annual network review requirements in 
  Sec. 58.25. This shall discuss the existing PM networks, including modifications to 
  the number, size or boundaries of monitoring planning areas and optional community 
  monitoring zones; number and location of PM sub 10 and PM sub 2.5 SLAMS; number and 
  location of core PM sub 2.5 SLAMS; alternative sampling frequencies proposed for PM 
  sub 2.5 SLAMS (including core PM sub 2.5 SLAMS and PM sub 2.5 NAMS), core PM sub 
  2.5 SLAMS to be designated PM sub 2.5 NAMS; and PM sub 10 and PM sub 2.5 SLAMS to 
  be designated PM sub 10 and PM sub 2.5 NAMS respectively.
  
      (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 
  that are described in the State's PM monitoring network description and are 
  intended for SIP purposes. These include those population-oriented SPMs that 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 an alternative annual date to be negotiated between 
  the State and Regional Administrator. The Region shall provide review and 
  approval/disapproval within 60 days. After 3 years following September 16, 1997, 
  the schedule for submitting the required annual revised PM sub 2.5 monitoring 
  network description may be altered based on a new schedule determined by the 
  Regional Administrator. States may submit an alternative PM monitoring network 
  description in which it requests exemptions from specific required elements of the 
  network design (e.g., required number of core sites, other SLAMS, sampling 
  frequency, etc.). After 3 years following September 16, 1997 or once a CMZ 
  monitoring area has been determined to violate the NAAQS, then changes to an MPA 
  monitoring network affecting the violating locations shall require public review 
  and notification.
  
      h. Section 58.30 is amended by revising the introductory text of paragraph (a) 
  to read as follows:
  
   Sec. 58.30 -- NAMS network establishment.
  
      (a) By January 1, 1980, with the exception of PM sub 10 and PM sub 2.5 
  samplers, which shall be by July 1, 1998, the State shall:
  
      * * * * *
  
      i. 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 PM 
  sub 2.5, the monitoring planning area and community monitoring zone, as defined in 
  Appendix D of this part.
  
      * * * * *
  
      j. In Sec. 58.34, the introductory text is revised to read as follows:
  
   Sec. 58.34 -- NAMS network completion.
  
      With the exception of PM sub 10 samplers, which shall be by 1 year after 
  September 16, 1997, and PM sub 2.5, which shall be by 3 years after September 16, 
  1997:
  
      * * * * *
  
      k. 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 SO sup 2, CO, O sub 3, NO sub 2, Pb, PM sub 10, and PM sub 2.5, 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. * * *
  
      * * * * *
  
      l. Revise Appendix A of part 58 to read as follows:
  
  Appendix A- 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 
  (QA/QC) 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, developing data quality objectives, 
  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 audits, 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 QA and QC activities used by a monitoring agency 
  depend on a number of local factors such as the field and laboratory conditions, 
  the objectives for 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 
  while achieving the Ambient Air Quality Programs data quality objectives.
  
  2. Quality System Requirements.
  
      2.1 Each State and local agency must develop a quality system (Reference 2 of 
  this Appendix) to ensure that the monitoring results:
  
      (a) Meet a well- defined need, use, or purpose.
  
      (b) Satisfy customers' expectations.
  
      (c) Comply with applicable standards specifications.
  
      (d) Comply with statutory (and other) requirements of society.
  
      (e) Reflect consideration of cost and economics.
  
      (f) Implement a quality assurance program consisting of policies, procedures, 
  specifications, standards, and documentation necessary to: {pg 38834}
  
      (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 in accordance with Agency requirements (Reference 4 of this Appendix), 
  and approved by the appropriate Regional Administrator, or the Regional 
  Administrator's designee. The Quality Assurance Program will be reviewed during the 
  systems audits described in section 2.5 of this Appendix.
  
      2.2 Primary requirements and guidance documents for developing the quality 
  assurance program are contained in References 2 through 7 of this Appendix, which 
  also contain many suggested and required procedures, checks, and control 
  specifications. Reference 7 of this Appendix describes specific guidance for the 
  development of a QA Program for SLAMS. Many specific quality control checks and 
  specifications for methods are included in the respective reference methods 
  described in part 50 of this chapter or in the respective equivalent method 
  descriptions available from EPA (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 of this Appendix. Quality assurance 
  procedures for VOC, NO sub x (including NO and NO sub 2), O sub 3, and carbonyl 
  measurements at PAMS must be consistent with Reference 15 of this Appendix. 
  Reference 4 of this Appendix includes requirements for the development of quality 
  assurance project plans, and quality assurance and control programs, and systems 
  audits demonstrating attainment of the requirements.
  
      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, SO sub 2, 
  NO, and NO sub 2 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 of this Appendix.
  
      2.3.2 Test concentrations for O sub 3 must be obtained in accordance with the 
  UV photometric calibration procedure specified in 40 CFR part 50, Appendix D, or by 
  means of a certified ozone transfer standard. Consult References 11 and 12 of this 
  Appendix for guidance on primary and transfer standards for O sub 3.
  
      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 of this Appendix.
  
      2.4 National Performance Audit Program (NPAP). Agencies operating SLAMS are 
  required to participate in EPA's NPAP. These audits are described in Reference 7 of 
  this Appendix. For further instructions, agencies should contact either the 
  appropriate EPA Regional QA Coordinator at the appropriate EPA Regional Office 
  location, or the NPAP Coordinator, Emissions Monitoring and Analysis Division (MD- 
  14), 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 3 years by 
  the appropriate EPA Regional Office. Systems audit programs are described in 
  Reference 7 of this Appendix. For further instructions, agencies should contact 
  either the appropriate EPA Regional QA Coordinator or the Systems Audit QA 
  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. Measurement uncertainty is estimated for both automated and manual 
  methods. Terminology associated with measurement uncertainty are found within this 
  Appendix and includes:
  
      (a) Precision. A measurement of mutual agreement among individual measurements 
  of the same property usually under prescribed similar conditions, expressed 
  generally in terms of the standard deviation;
  
      (b) Accuracy. The degree of agreement between an observed value and an accepted 
  reference value, accuracy includes a combination of random error (precision) and 
  systematic error (bias) components which are due to sampling and analytical 
  operations;
  
      (c) Bias. The systematic or persistent distortion of a measurement process 
  which causes errors in one direction. The individual results of these tests for 
  each method or analyzer shall be reported to EPA as specified in section 4 of this 
  Appendix. EPA will then calculate quarterly assessments of measurement uncertainty 
  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 Estimates of the data quality will be calculated on the basis of single 
  monitors and reporting organizations and may also be calculated for each region and 
  for the entire Nation. 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 data quality 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 measurement 
  uncertainty among all stations in the organization can be expected to be reasonably 
  homogeneous, as a result of common factors.
  
      (a) 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.
  
      (3) Oversight by a common quality assurance organization.
  
      (4) Support by a common laboratory or headquarters.
  
      (b) 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. 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. 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 Excluding PM sub 2.5.
  
      3.1.1 Methods for SO sub 2, NO sub 2, O sub 3 and CO. A one- point precision 
  check must be performed at least once every 2 weeks on each automated analyzer used 
  to measure SO sub 2, NO sub 2, O sub 3 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 SO 
  sub 2, NO sub 2, and O sub 3 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 SO sub 2, NO sub 2, and O sub 3, or 0 to 100 ppm for CO, use precision check 
  gases of appropriately higher concentration as approved by the appropriate Regional 
  Administrator or their 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. {pg 38835}
  
      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 in section 
  3.1.1. 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. of 
  this Appendix.
  
      3.1.2 Methods for Particulate Matter Excluding PM sub 2.5. A one-point 
  precision check must be performed at least once every 2 weeks on each automated 
  analyzer used to measure PM sub 10. 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 of this Appendix 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 three 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%.
  
      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 
  indicated flow rates are used to assess the precision of the monitoring data as 
  described in section 5.1 of this Appendix (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. of this 
  Appendix.
  
      3.2 Accuracy of Automated Methods Excluding PM sub 2.5.
  
      3.2.1 Methods for SO sub 2, NO sub 2, O sub 3, 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 SO sub 2, NO sub 2, O sub 
  3, 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 (a) 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:
  
  
   Audit Level                Concentration Range, PPM
                   SO sub 2, O     NO sub 2        CO
                   sub 3
   
   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
   
   
  
      (b) NO sub 2 audit gas for chemiluminescence-type NO sub 2 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-NO sub x 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 NO sub 2 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 SO sub 2, NO sub 2, and O sub 3 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 of this Appendix. 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 
  of this Appendix 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 of 
  this Appendix. {pg 38836} 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 of this Appendix.
  
      3.2.2 Methods for Particulate Matter Excluding PM sub 2.5.
  
      3.2.2.1 Each calendar quarter, audit the flow rate of at least 25 percent of 
  the SLAMS PM sub 10 analyzers such that each PM sub 10 analyzer is audited at least 
  once per year. If there are fewer than four PM sub 10 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 of this Appendix. 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 (PM sub 10) as 
  described in section 5.2 of this Appendix.
  
      3.3 Precision of Manual Methods Excluding PM sub 2.5.
  
      3.3.1 For each network of manual methods other than for PM sub 2.5, 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. Where possible, additional 
  collocated sampling is encouraged. For purposes of precision assessment, networks 
  for measuring TSP and PM sub 10 shall be considered separately from one another. PM 
  sub 10 and TSP 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 PM sub 10, 
  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 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.
  
      3.3.4 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. 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. A six-day sampling 
  schedule is required. Report the measurements from both samplers at each collocated 
  sampling site. The calculations for evaluating precision between the two collocated 
  samplers are described in section 5.3 of this Appendix.
  
      3.4 Accuracy of Manual Methods Excluding PM sub 2.5. The accuracy of manual 
  sampling methods is assessed by auditing a portion of the measurement process.
  
      3.4.1 Procedures for PM sub 10 and TSP.
  
      3.4.1.1 Procedures for flow rate audits for PM sub 10. Each calendar quarter, 
  audit the flow rate of at least 25 percent of the PM sub 10 samplers such that each 
  PM sub 10 sampler is audited at least once per year. If there are fewer than four 
  PM sub 10 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 of this Appendix. 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 and bias as described in section 5.4.1 of this Appendix.
  
      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 SO sub 2 Methods.
  
      3.4.2.1 Prepare audit solutions from a working sulfite-tetrachloromercurate 
  (TCM) solution as described in section 10.2 of the SO sub 2 Reference Method (40 
  CFR part 50, Appendix A). 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 mu g SO sub 2/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 mu g SO sub 2/ml) and the 
  corresponding indicated concentrations (in mu g SO sub 2/ml). The percent 
  differences between these concentrations are used to calculate accuracy as 
  described in section 5.4.2 of this Appendix.
  
      3.4.3 NO sub 2 Methods. Prepare audit solutions from a working sodium nitrite 
  solution as described in the appropriate equivalent method (see Reference 8 of this 
  Appendix). 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 mu g NO sub 2/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 mu g NO sub 2/ml) and the corresponding indicated concentrations (in mu g NO 
  sub 2/ml). The percent differences between these concentrations are used to 
  calculate accuracy as described in section 5.4.2 of this Appendix.
  
      3.4.4 Pb Methods.
  
      3.4.4.1 For the Pb Reference Method (40 CFR part 50, Appendix G), 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 of this Appendix. 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 {pg 38837} 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:
  
  
   Range       Pb Concentration, mu  Equivalent Ambient
               g/Strip               Pb Concentration, mu
                                     g/m sup 3  fn 1
   
   1           100-300               0.5-1.5
   2           600-1000              3.0-5.0
   
   fn 1  Equivalent ambient Pb concentration in mu  g/m sup 3  is
   based on sampling at 1.7 m sup 3 /min for 24 hours on a 20.3
   cmx25.4 cm (8 inchx10 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 mu g 
  Pb/strip) and the corresponding measured concentrations (in mu 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 of this Appendix.
  
      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.
  
      3.5 Measurement Uncertainty for Automated and Manual PM sub 2.5 Methods. The 
  goal for acceptable measurement uncertainty has been defined as 10 percent 
  coefficient of variation (CV) for total precision and +/- 10 percent for total bias 
  (Reference 14 of this Appendix).
  
      3.5.1 Flow Rate Audits.
  
      3.5.1.1 Automated methods for PM sub 2.5. A one-point precision check must be 
  performed at least once every 2 weeks on each automated analyzer used to measure PM 
  sub 2.5. 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.
  
      3.5.1.1.1 Standard procedure: Use a flow rate transfer standard certified in 
  accordance with section 2.3.3 of this Appendix 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.
  
      3.5.1.1.2 Alternative procedure: 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 the flow meter is audited with 
  an external flow rate transfer standard at least every 6 months; records of at 
  least the three 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 the instrument and flow meter give no indication of 
  improper operation. 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.
  
      3.5.1.1.3 For either procedure, the differences between the actual and 
  indicated flow rates are used to assess the precision of the monitoring data as 
  described in section 5.5 of this Appendix.
  
      3.5.1.2 Manual methods for PM sub 2.5. Each calendar quarter, audit the flow 
  rate of each SLAMS PM sub 2.5 analyzer. 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 of this Appendix. 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 
  procedures used to calculate measurement uncertainty PM sub 2.5 are described in 
  section 5.5 of this Appendix.
  
      3.5.2 Measurement of Precision using Collocated Procedures for Automated and 
  Manual Methods of PM sub 2.5.
  
      (a) For PM sub 2.5 sites within a reporting organization each EPA designated 
  Federal reference method (FRM) or Federal equivalent method (FEM) must:
  
      (1) Have 25 percent of the monitors collocated (values of .5 and greater round 
  up).
  
      (2) Have at least 1 collocated monitor (if the total number of monitors is less 
  than 4). The first collocated monitor must be a designated FRM monitor.
  
      (b) In addition, monitors selected must also meet the following requirements:
  
      (1) A monitor designated as an EPA FRM shall be collocated with a monitor 
  having the same EPA FRM designation.
  
      (2) For each monitor designated as an EPA FEM, 50 percent of the designated 
  monitors shall be collocated with a monitor having the same method designation and 
  50 percent of the monitors shall be collocated with an FRM monitor. If there are an 
  odd number of collocated monitors required, the additional monitor shall be an FRM. 
  An example of this procedure is found in Table A-2 of this Appendix.
  
      (c) For PM sub 2.5 sites during the initial deployment of the SLAMS network, 
  special emphasis should be placed on those sites in areas likely to be in violation 
  of the NAAQS. Once areas are initially determined to be in violation, the 
  collocated monitors should be deployed according to the following protocol:
  
      (1) Eighty percent of the collocated monitors should be deployed at sites with 
  concentrations " ninety percent of the annual PM sub 2.5 NAAQS (or 24-hour NAAQS if 
  that is affecting the area); one hundred percent if all sites have concentrations 
  above either NAAQS, and each area determined to be in violation should be 
  represented by at least one collocated monitor.
  
      (2) The remaining 20 percent of the collocated monitors should be deployed at 
  sites with concentrations < ninety percent of the annual PM sub 2.5 NAAQS (or 24-
  hour NAAQS if that is affecting the area)
  
      (3) If an organization has no sites at concentration ranges " ninety percent of 
  the annual PM sub 2.5 NAAQS (or 24-hour NAAQS if that is affecting the area), 60 
  percent of the collocated monitors should be deployed at those sites with the 
  annual mean PM sub 2.5 concentrations (or 24-hour NAAQS if that is affecting the 
  area) among the highest 25 percent for all PM sub 2.5 sites in the network.
  
      3.5.2.1 In determining the number of collocated sites required for PM sub 2.5, 
  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 instead of a PM sub 2.5 measurement if the latter 
  measurement is unavailable. Any PM sub 2.5 monitoring site which does not have a 
  monitor which is an EPA federal reference or equivalent method is not required to 
  be included in the number of sites which are used to determine the number of 
  collocated monitors.
  
      3.5.2.2 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.
  
      3.5.2.3 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. Each duplicate sampler must be 
  operated concurrently with its associated primary sampler. The operation schedule 
  should be selected so that the sampling days are distributed evenly over the year 
  and over the 7 days of the week and therefore, a 6-day sampling schedule is 
  required. Report the measurements from both samplers at each collocated sampling 
  site. The calculations for evaluating precision between the two collocated samplers 
  are described in section 5.5 of this Appendix.
  
      3.5.3 Measurement of Bias using the FRM Audit Procedures for Automated and 
  Manual Methods of PM sub 2.5.
  
      3.5.3.1 The FRM audit is an independent assessment of the total measurement 
  system bias. These audits will be performed under the National Performance Audit 
  Program {pg 38838} (section 2.4 of this Appendix) or a comparable program. Twenty-
  five percent of the SLAMS monitors within each reporting organization will be 
  assessed with an FRM audit each year. Additionally, every designated FRM or FEM 
  within a reporting organization must:
  
      (a) Have at least 25 percent of each method designation audited, including 
  collocated sites (even those collocated with FRM instruments), (values of .5 and 
  greater round up).
  
      (b) Have at least one monitor audited.
  
      (c) Be audited at a frequency of four audits per year.
  
      (d) Have all FRM or FEM samples subject to an FRM audit at least once every 4 
  years. Table A-2 illustrates the procedure mentioned above.
  
      3.5.3.2 For PM sub 2.5 sites during the initial deployment of the SLAMS 
  network, special emphasis should be placed on those sites in areas likely to be in 
  violation of the NAAQS. Once areas are initially determined to be in violation, the 
  FRM audit program should be implemented according to the following protocol:
  
      (a) Eighty percent of the FRM audits should be deployed at sites with 
  concentrations " ninety percent of the annual PM sub 2.5 NAAQS (or 24-hour NAAQS if 
  that is affecting the area); one hundred percent if all sites have concentrations 
  above either NAAQS, and each area determined to be in violation should implement an 
  FRM audit at a minimum of one monitor within that area.
  
      (b) The remaining 20 percent of the FRM audits should be implemented at sites 
  with concentrations < ninety percent of the annual PM sub 2.5 NAAQS (or 24-hour 
  NAAQS if that is affecting the area).
  
      (c) If an organization has no sites at concentration ranges " ninety percent of 
  the annual PM sub 2.5 NAAQS (or 24-hour NAAQS if that is affecting the area), 60 
  percent of the FRM audits should be implemented at those sites with the annual mean 
  PM sub 2.5 concentrations (or 24-hour NAAQS if that is affecting the area) among 
  the highest 25 percent for all PM sub 2.5 sites in the network. Additional 
  information concerning the FRM audit program is contained in Reference 7 of this 
  Appendix. The calculations for evaluating bias between the primary monitor and the 
  FRM audit are described in section 5.5.
  
  4. Reporting Requirements.
  
      (a) 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, bias 
  and accuracy tests it has carried out during the quarter. The quarterly reports of 
  precision, bias 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). EPA strongly encourages early submittal of the QA data in order to assist 
  the State and Local agencies in controlling and evaluating the quality of the 
  ambient air SLAMS data. Each organization shall report all QA/QC measurements. 
  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, 
  bias and accuracy.
  
      4.2 Annual Reports.
  
      4.2.1 When precision, bias and accuracy estimates for a reporting organization 
  have been calculated for all four quarters of the calendar year, EPA will calculate 
  and report the measurement uncertainty 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.
  
      (a) Calculations of measurement uncertainty are carried out by EPA according to 
  the following procedures. Reporting organizations should report the data for 
  individual precision, bias 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 Excluding PM sub 2.5. Estimates of the 
  precision of automated methods are calculated from the results of biweekly 
  precision checks as specified in section 3.1 of this Appendix. 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 (d sub i) for each precision check is calculated 
  using equation 1, where Y sub i is the concentration indicated by the analyzer for 
  the I-th precision check and X sub i is the known concentration for the I-th 
  precision check, as follows:
  
  Equation 1
  
  {SEE ILLUSTRATION(S) IN ORIGINAL DOCUMENT}
  
      5.1.1.2 For each analyzer, the quarterly average (d sub j) is calculated with 
  equation 2, and the standard deviation (S sub j) 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. 
  Equation 2 and 3 follow:
  
  Equation 2
  
  {SEE ILLUSTRATION(S) IN ORIGINAL DOCUMENT}
  
  Equation 3
  
  {SEE ILLUSTRATION(S) IN ORIGINAL DOCUMENT}
  
      5.1.2 Precision for Reporting Organization.
  
      5.1.2.1 For each pollutant, the average of averages (D) and the pooled standard 
  deviation (S sub a) 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, as follows:
  
  {SEE ILLUSTRATION(S) IN ORIGINAL DOCUMENT}
  
      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, as follows: {pg 
  38839}
  
  {SEE ILLUSTRATION(S) IN ORIGINAL DOCUMENT}
  
      5.2 Accuracy of Automated Methods Excluding PM sub 2.5. Estimates of the 
  accuracy of automated methods are calculated from the results of independent audits 
  as described in section 3.2 of this Appendix. 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 of this 
  Appendix.
  
      5.2.1 Single Analyzer Accuracy. The percentage difference (d sub i) for each 
  audit concentration is calculated using equation 1, where Y sub i is the analyzer's 
  indicated concentration measurement from the I-th audit check and X sub i 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 (d sub i) for all n analyzers 
  audited during the quarter is calculated using equation 8, as follows:
  
  Equation 8
  
  {SEE ILLUSTRATION(S) IN ORIGINAL DOCUMENT}
  
      5.2.2.2 For each concentration level of a particular pollutant, the standard 
  deviation (S sub a) of all the individual percentage differences for all n 
  analyzers audited during the quarter is calculated, using equation 9, as follows:
  
  Equation 9
  
  {SEE ILLUSTRATION(S) IN ORIGINAL DOCUMENT}
  
      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 Excluding PM sub 2.5. Estimates of precision of 
  manual methods are calculated from the results obtained from collocated samplers as 
  described in section 3.3 of this Appendix. 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:
  
      (a) TSP: 20  mu g/m sup 3.
  
      (b) SO sub 2: 45  mu g/m sup 3.
  
      (c) NO sub 2: 30  mu g/m sup 3.
  
      (d) Pb: 0.15  mu g/m sup 3.
  
      (e) PM sub 10: 20  mu g/m sup 3.
  
      5.3.1.2 For each selected measurement pair, the percent difference (d sub i) is 
  calculated, using equation 10, as follows:
  
  Equation 10
  
  {SEE ILLUSTRATION(S) IN ORIGINAL DOCUMENT}
  
  where:
  
  Y sub i is the pollutant concentration measurement obtained from the duplicate 
  sampler; and
  
  X sub i is the concentration measurement obtained from the primary sampler 
  designated for reporting air quality for the site.
  
      (a) For each site, the quarterly average percent difference (d sub j) is 
  calculated from equation 2 and the standard deviation (S sub j) 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 (S sub a) 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, as follows:
  
  Equation 11
  
  {SEE ILLUSTRATION(S) IN ORIGINAL DOCUMENT}
  
  Equation 12
  
  {SEE ILLUSTRATION(S) IN ORIGINAL DOCUMENT}
  
      5.4 Accuracy of Manual Methods Excluding PM sub 2.5. Estimates of the accuracy 
  of manual methods are calculated from the results of independent audits as 
  described in section 3.4 of this Appendix. 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 PM sub 2.5 (including reference 
  method Pb samplers).
  
      5.4.1.1 Single Sampler Accuracy. For the flow rate audit described in section 
  3.4.1 of this Appendix, the percentage difference (d sub i) for each audit is 
  calculated using equation 1, where X sub i represents the known flow rate and Y sub 
  i 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 (S sub a) 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 SO sub 2, NO sub 2, and Pb.
  
      5.4.2.1 Single Analysis-Day Accuracy. For each of the audits of the analytical 
  methods for SO sub 2, NO sub 2, and Pb described in sections 3.4.2, 3.4.3, and 
  3.4.4 of this Appendix, the percentage difference (d sub j) at each concentration 
  level is calculated using equation 1, where X sub j represents the known value of 
  the audit sample and Y sub j represents the value of SO sub 2, NO sub 2, or Pb 
  indicated by the analytical method.
  
      5.4.2.2 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 (S sub a) 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.
  
      5.5 Precision, Accuracy and Bias for Automated and Manual PM sub 2.5 Methods.
  
      (a) Reporting organizations are required to report the data that will allow 
  assessments of the following individual quality control checks and audits:
  
      (1) Flow rate audit.
  
      (2) Collocated samplers, where the duplicate sampler is not an FRM device.
  
      (3) Collocated samplers, where the duplicate sampler is an FRM device.
  
      (4) FRM audits.
  
      (b) EPA uses the reported results to derive precision, accuracy and bias 
  estimates according to the following procedures.
  
      5.5.1 Flow Rate Audits. The reporting organization shall report both the audit 
  standard flow rate and the flow rate indicated by the sampling instrument. These 
  results are {pg 38840} used by EPA to calculate flow rate accuracy and bias 
  estimates.
  
      5.5.1.1 Accuracy of a Single Sampler - Single Check (Quarterly) Basis (d sub 
  i). The percentage difference (d sub i) for a single flow rate audit d sub i is 
  calculated using Equation 13, where X sub i represents the audit standard flow rate 
  (known) and Y sub i represents the indicated flow rate, as follows:
  
  Equation 13
  
  {SEE ILLUSTRATION(S) IN ORIGINAL DOCUMENT}
  
      5.5.1.2 Bias of a Single Sampler - Annual Basis (D sub j). For an individual 
  particulate sampler j, the average (D sub j) of the individual percentage 
  differences (d sub i) during the calendar year is calculated using Equation 14, 
  where n sub j is the number of individual percentage differences produced for 
  sampler j during the calendar year, as follows:
  
  Equation 14
  
  {SEE ILLUSTRATION(S) IN ORIGINAL DOCUMENT}
  
      5.5.1.3 Bias for Each EPA Federal Reference and Equivalent Method Designation 
  Employed by Each Reporting Organization - Quarterly Basis (D sub k,q). For method 
  designation k used by the reporting organization, quarter q's single sampler 
  percentage differences (d sub i) are averaged using Equation 16, where n sub k,q is 
  the number of individual percentage differences produced for method designation k 
  in quarter q, as follows:
  
  Equation 15
  
  {SEE ILLUSTRATION(S) IN ORIGINAL DOCUMENT}
  
      5.5.1.4 Bias for Each Reporting Organization - Quarterly Basis (D sub q). For 
  each reporting organization, quarter q's single sampler percentage differences (d 
  sub i) are averaged using Equation 16, to produce a single average for each 
  reporting organization, where n sub q is the total number of single sampler 
  percentage differences for all federal reference or equivalent methods of samplers 
  in quarter q, as follows:
  
  Equation 16
  
  {SEE ILLUSTRATION(S) IN ORIGINAL DOCUMENT}
  
      5.5.1.5 Bias for Each EPA Federal Reference and Equivalent Method Designation 
  Employed by Each Reporting Organization - Annual Basis (D sub k). For method 
  designation k used by the reporting organization, the annual average percentage 
  difference, D sub k, is derived using Equation 17, where D sub k,q is the average 
  reported for method designation k during the qth quarter, and n sub k,q is the 
  number of the method designation k's monitors that were deployed during the qth 
  quarter, as follows:
  
  Equation 17
  
  {SEE ILLUSTRATION(S) IN ORIGINAL DOCUMENT}
  
      5.5.1.6 Bias for Each Reporting Organization - Annual Basis (D). For each 
  reporting organization, the annual average percentage difference, D, is derived 
  using Equation 18, where D sub q is the average reported for the reporting 
  organization during the qth quarter, and n sub q is the total number monitors that 
  were deployed during the qth quarter. A single annual average is produced for each 
  reporting organization. Equation 18 follows:
  
  Equation 18
  
  {SEE ILLUSTRATION(S) IN ORIGINAL DOCUMENT}
  
      5.5.2 Collocated Samplers, Where the Duplicate Sampler is not an FRM Device. 
  (a) At low concentrations, agreement between the measurements of collocated 
  samplers 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:
  
      PM sub 2.5 : 6  mu g/m sup 3
  
  (b) Collocated sampler results are used to assess measurement system precision. A 
  collocated sampler pair consists of a primary sampler (used for routine monitoring) 
  and a duplicate sampler (used as a quality control check). Quarterly precision 
  estimates are calculated by EPA for each pair of collocated samplers and for each 
  method designation employed by each reporting organization. Annual precision 
  estimates are calculated by EPA for each primary sampler, for each EPA Federal 
  reference method and equivalent method designation employed by each reporting 
  organization, and nationally for each EPA Federal reference method and equivalent 
  method designation.
  
      5.5.2.1 Percent Difference for a Single Check (d sub i). The percentage 
  difference, d sub i, for each check is calculated by EPA using Equation 19, where X 
  sub i represents the concentration produced from the primary sampler and Y sub i 
  represents concentration reported for the duplicate sampler, as follows:
  
  Equation 19
  
  {SEE ILLUSTRATION(S) IN ORIGINAL DOCUMENT}
  
      5.5.2.2 Coefficient of Variation (CV) for a Single Check (CV sub i). The 
  coefficient of variation, CV sub i, for each check is calculated by EPA by dividing 
  the absolute value of the percentage difference, d sub i, by the square root of two 
  as shown in Equation 20, as follows:
  
  Equation 20
  
  {SEE ILLUSTRATION(S) IN ORIGINAL DOCUMENT}
  
      5.5.2.3 Precision of a Single Sampler - Quarterly Basis (CV sub j,q).
  
      (a) For particulate sampler j, the individual coefficients of variation (CV sub 
  j,q) during the quarter are pooled using Equation 21, where n sub j,q is the number 
  of pairs of measurements from collocated samplers during the quarter, as follows:
  
  Equation 21
  
  {SEE ILLUSTRATION(S) IN ORIGINAL DOCUMENT}
  
      (b) The 90 percent confidence limits for the single sampler's CV are calculated 
  by EPA using Equations 22 and 23, where X sup 2  sub 0.05,df and X sup 2  sub 
  0.95,df are the 0.05 and 0.95 quantiles of the chi-square (X sup 2) distribution 
  with n sub j,q degrees of freedom, as follows:
  
  Equation 22
  
  {SEE ILLUSTRATION(S) IN ORIGINAL DOCUMENT}
  
  Equation 23
  
  {SEE ILLUSTRATION(S) IN ORIGINAL DOCUMENT}
  
      5.5.2.4 Precision of a Single Sampler - Annual Basis. For particulate sampler 
  j, the individual coefficients of variation, CV sub i, produced during the calendar 
  year are pooled using Equation 21, where n sub j is the number of checks made 
  during the calendar year. The 90 percent confidence limits for the single sampler's 
  CV are calculated by EPA using Equations 22 and 23, where X sup 2  sub 0.05,df and 
  X sup 2  sub 0.95,df are the 0.05 and 0.95 quantiles of the chi-square (X sup 2) 
  distribution with n sub j degrees of freedom.
  
      5.5.2.5 Precision for Each EPA Federal Reference Method and Equivalent Method 
  Designation Employed by Each Reporting Organization - Quarterly Basis (CV sub k,q).
  
      (a) For each method designation k used by the reporting organization, the 
  quarter's single sampler coefficients of variation, CV sub j,qs, obtained from 
  Equation 21, are pooled using Equation 24, where n sub k,q is the number of 
  collocated primary monitors for the designated method (but not collocated with FRM 
  samplers) and n sub j,q is the number of degrees of freedom associated with CV sub 
  j,q, as follows:  {pg 38841}
  
  Equation 24
  
  {SEE ILLUSTRATION(S) IN ORIGINAL DOCUMENT}
  
      (b) The number of method CVs produced for a reporting organization will equal 
  the number of different method designations having more than one primary monitor 
  employed by the organization during the quarter. (When exactly one monitor of a 
  specified designation is used by a reporting organization, it will be collocated 
  with an FRM sampler.)
  
      5.5.2.6 Precision for Each Method Designation Employed by Each Reporting 
  Organization- Annual Basis (CV sub k). For each method designation k used by the 
  reporting organization, the quarterly estimated coefficients of variation, CV sub 
  k,q, are pooled using Equation 25, where n sub k,q is the number of collocated 
  primary monitors for the designated method during the qth quarter and also the 
  number of degrees of freedom associated with the quarter's precision estimate for 
  the method designation, CV sub k,q, as follows:
  
  Equation 25
  
  {SEE ILLUSTRATION(S) IN ORIGINAL DOCUMENT}
  
      5.5.3 Collocated Samplers, Where the Duplicate Sampler is an FRM Device. At low 
  concentrations, agreement between the measurements of collocated samplers 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: PM sub 2.5: 6  mu g/m sup 3. These duplicate sampler results are used to 
  assess measurement system bias. Quarterly bias estimates are calculated by EPA for 
  each primary sampler and for each method designation employed by each reporting 
  organization. Annual precision estimates are calculated by EPA for each primary 
  monitor, for each method designation employed by each reporting organization, and 
  nationally for each method designation.
  
      5.5.3.1 Accuracy for a Single Check (d' sub i). The percentage difference, d' 
  sub i, for each check is calculated by EPA using Equation 26, where X sub i 
  represents the concentration produced from the FRM sampler taken as the true value 
  and Y sub i represents concentration reported for the primary sampler, as follows:
  
  Equation 26
  
  {SEE ILLUSTRATION(S) IN ORIGINAL DOCUMENT}
  
      5.5.3.2 Bias of a Single Sampler - Quarterly Basis (D' sub j,q).
  
      (a) For particulate sampler j, the average of the individual percentage 
  differences during the quarter q is calculated by EPA using Equation 27, where n 
  sub j,q is the number of checks made for sampler j during the calendar quarter, as 
  follows:
  
  Equation 27
  
  {SEE ILLUSTRATION(S) IN ORIGINAL DOCUMENT}
  
      (b) The standard deviation, s' sub j,q, of sampler j's percentage differences 
  for quarter q is calculated using Equation 28, as follows:
  
  Equation 28
  
  {SEE ILLUSTRATION(S) IN ORIGINAL DOCUMENT}
  
      (c) The 95 Percent Confidence Limits for the single sampler's bias are 
  calculated using Equations 29 and 30 where t sub 0.975,df is the 0.975 quantile of 
  Student's t distribution with df n sub j,q-1 degrees of freedom, as follows:
  
  Equation 29
  
  {SEE ILLUSTRATION(S) IN ORIGINAL DOCUMENT}
  
  Equation 30
  
  {SEE ILLUSTRATION(S) IN ORIGINAL DOCUMENT}
  
      5.5.3.3 Bias of a Single Sampler - Annual Basis (D' sub j).
  
      (a) For particulate sampler j, the mean bias for the year is derived from the 
  quarterly bias estimates, D' sub j,q, using Equation 31, where the variables are as 
  defined for Equations 27 and 28, as follows:
  
  Equation 31
  
  {SEE ILLUSTRATION(S) IN ORIGINAL DOCUMENT}
  
      (b) The standard error of the above estimate, se sub j' is calculated using 
  Equation 32, as follows:
  
  Equation 32
  
  {SEE ILLUSTRATION(S) IN ORIGINAL DOCUMENT}
  
      (c) The 95 Percent Confidence Limits for the single sampler's bias are 
  calculated using Equations 33 and 34, where t sub 0.975,df is the 0.975 quantile of 
  Student's t distribution with df (n sub j,1+n sub j,2+n sub j,3+n sub j,4-4) 
  degrees of freedom, as follows:
  
  Equation 33
  
  {SEE ILLUSTRATION(S) IN ORIGINAL DOCUMENT}
  
  Equation 34
  
  {SEE ILLUSTRATION(S) IN ORIGINAL DOCUMENT}
  
      5.5.3.4 Bias for a Single Reporting Organization (D') - Annual Basis. The 
  reporting organizations mean bias is calculated using Equation 35, where variables 
  are as defined in Equations 31 and 32, as follows:
  
  Equation 35
  
  {SEE ILLUSTRATION(S) IN ORIGINAL DOCUMENT}
  
      5.5.4 FRM Audits. FRM Audits are performed once per quarter for selected 
  samplers. The reporting organization reports concentration data from the primary 
  sampler. Calculations for FRM Audits are similar to those for collocated samplers 
  having FRM samplers as duplicates. The calculations differ because only one check 
  is performed per quarter.
  
      5.5.4.1 Accuracy for a Single Sampler, Quarterly Basis (d sub i). The 
  percentage difference, d sub i, for each check is calculated using Equation 26, 
  where X sub i represents the concentration produced from the FRM sampler and Y sub 
  i represents the concentration reported for the primary sampler. For quarter q, the 
  bias estimate for sampler j is denoted D sub j,q.
  
      5.5.4.2 Bias of a Single Sampler - Annual Basis (D' sub j). For particulate 
  sampler j, the mean bias for the year is derived from the quarterly bias estimates, 
  D sub j,q, using Equation 31, where n sub j,q equals 1 because one FRM audit is 
  performed per quarter.
  
      5.5.4.3. Bias for a Single Reporting Organization - Annual Basis (D'). The 
  reporting organizations mean bias is calculated using Equation 35, where variables 
  are as defined in Equations 31 and 32.
  
  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 {pg 
  38842} 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 EPA-600/R-94/038b. 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.
  
      (7a) Copies of section 2.12 of the Quality Assurance Handbook for Air Pollution 
  Measurement Systems, are available from Department E (MD-77B), U.S. EPA, Research 
  Triangle Park, NC 27711.
  
      (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.
  
      (13) Musick, D.R. The Ambient Air Precision and Accuracy Program: 1995 Annual 
  Report. EPA-454/R97001. U.S. Environmental Protection Agency, Research Triangle 
  Park, NC 27711, February 1997.
  
      (14) Papp, M.L., J,B., Elkins, D.R., Musick and M.J., Messner, Data Quality 
  Objectives for the PM sub 2.5. Monitoring Data, U.S. Environmental Protection 
  Agency, Research Triangle Park, NC 27711. In preparation.
  
      (15) Photochemical Assessment Monitoring Stations Implementation Manual. EPA-
  454/B-93-051, U.S. Environmental Protection Agency, Research Triangle Park, NC 
  27711, March 1994.
  
  Tables to Appendix A of Part 58
  
  
   Table  A-1.- Minimum Data Assessment Requirements
   
   Method                Assessment Method     Coverage
   
   Precision:
   Automated Methods     Response check at     Each analyzer
   for SO sub 2, NO sub  concentration
   2, O sub 3, and CO    between .08 and .10
                         ppm (8 & 10 ppm for
                         CO) fn 2
   Manual Methods: All   Collocated samplers   1 site for 1-5 sites
   methods except PM                           2 sites for 6-20
   sub 2.5                                     sites 3 sites >20
                                               sites (sites with
                                               highest conc.)
   Accuracy:
   Automated Methods     Response check at     1. Each analyzer 2.
   for SO sub 2, NO sub  .03-.08 ppm fn 1,2    25% of analyzers (at
   2, O sub 3, and CO    .15-.20 ppm fn 1,2    least 1)
                         .35-.45 ppm fn 1,2
                         80-.90 ppm fn 1,2
                         (if applicable)
   Manual Methods for    Check of analytical   Analytical system
   SO sub 2, and NO sub  procedure with audit
   2                     standard solutions
   TSP, PM sub 10        Check of sampler      1. Each sampler 2.
                         flow rate             25% of samplers (at
                                               least 1)
   Lead                  1. Check of sample    1. Each sampler
                         flow rate as for TSP
                         2. Check of           2. Analytical system
                         analytical system
                         with Pb audit strips
   PM sub 2.5
   Manual and Automated  Collocated samplers   25% of SLAMS
   Methods-Precision                           (monitors with Conc
                                               affecting NAAQS
                                               violation status)
   Manual and Automated  1. Check of sampler   25% of SLAMS
   Methods-Accuracy and  flow rate             (monitors with Conc
   Bias                                        affecting NAAQS
                                               violation status)
                         2. Audit with
                         reference method
   
   Method                Minimum Frequency     Parameters Reported
   
   Precision:
   Automated Methods     Once per 2 weeks      Actual concentration
   for SO sub 2, NO sub                        fn 2 and measured
   2, O sub 3, and CO                          concentration fn 3
   Manual Methods: All   Once every six days   Particle mass
   methods except PM                           concentration
   sub 2.5                                     indicated by sampler
                                               and by collocated
                                               sampler
   Accuracy:
   Automated Methods     1. Once per year 2.   Actual concentration
   for SO sub 2, NO sub  Each calendar         fn 2 and measured
   2, O sub 3, and CO    quarter               (indicated)
                                               concentration fn 3
                                               for each level
   Manual Methods for    Each day samples are  Actual concentration
   SO sub 2, and NO sub  analyzed, at least    and measured
   2                     twice per quarter     (indicated)
                                               concentration for
                                               each audit solution
   TSP, PM sub 10        1. Once per year 2.   Actual flow rate and
                         Each calendar         flow rate indicated
                         quarter               by the sampler
   Lead                  1. Include with TSP   1. Same as for TSP
                         2. Each quarter       2. Actual
                                               concentration and
                                               measured (indicated)
                                               concentration of
                                               audit samples ( mu g
                                               Pb/strip)
   PM sub 2.5
   Manual and Automated  Once every six days   1. Particle mass
   Methods-Precision                           concentration
                                               indicated by sampler
                                               and by collocated
                                               sampler 2. 24-hour
                                               value for automated
                                               methods
   Manual and Automated  1. Minimum of every   1. Actual flow rate
   Methods-Accuracy and  calendar quarter, 4   and flow rate
   Bias                  checks per year       indicated by sampler
                         2. Minimum 4          2. Particle mass
                         measurements per      concentration
                         year                  indicated by sampler
                                               and by audit
                                               reference sampler
   
   fn 1 Concentration times 100 for CO.
   
   fn 2 Effective concentration for open path analyzers.
   
   fn 3 Corrected concentration, if applicable, for open path
   analyzers.
   
   
  
   Table  A-2.- Summary of PM sub 2.5  Collocation and Audits
   Procedures As an Example of a Typical Reporting Organization
   Needing  43  Monitors, Having Procured FRMs and Three Other
   Equivalent Method Types
   
   Method          Total   of      Total             of
   Designation     Monitors        Collocated      Collocated
                                                   FRMs
   
   FRM             25              6               6
   Type A          10              3               2
   Type C          2               1               1
   Type D          6               2               1
   
   Method Designation      of Collocated         of Independent FRM
                         Monitors of Same      Audits
                         Type
   
   FRM                   n/a                   6
   Type A                1                     3
   Type C                0                     1
   Type D                1                     2
   
   
  
      m. Appendix C is amended by revising section 2.2 and adding sections 2.2.1 and 
  2.2.2, adding sections 2.4 through 2.5, revising section 2.7.1, and adding section 
  2.9 and references 4 through 6 to section 6.0 to read as follows:
  
  Appendix C-Ambient Air Quality Monitoring Methodology
  
      * * * * *
  
      2.2 Substitute PM sub 10 samplers.
  
      2.2.1 For purposes of showing compliance with the NAAQS for particulate matter, 
  a high volume TSP sampler described in 40 CFR part 50, Appendix B, may be used in a 
  SLAMS in lieu of a PM sub 10 monitor as long as the ambient concentrations of 
  particles measured by the TSP sampler are below the PM sub 10 NAAQS. If the TSP 
  sampler measures a single value that is higher than the PM sub 10 24-hour standard, 
  or if the annual average of its measurements is greater than the PM sub 10 annual 
  standard, the TSP sampler operating as a substitute PM sub 10 sampler must be 
  replaced with a PM sub 10 monitor. For a TSP measurement above the 24-hour 
  standard, the TSP sampler should be replaced with a PM sub 10 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 PM sub 10 monitor 
  should be operating by June 30 of the year following the exceedance.
  
      2.2.2 In order to maintain historical continuity of ambient particulate matter 
  trends and patterns for PM sub 10 NAMS that were previously TSP NAMS, the TSP high 
  volume sampler must be operated concurrently with the PM sub 10 monitor for a one-
  year period beginning with the PM sub 10 NAMS start-up date. The operating schedule 
  for the TSP sampler must be at least once every 6 days regardless of the PM sub 10 
  sampling frequency.
  
      * * * * *
  
      2.4 Approval of non-designated PM sub 2.5 methods operated at specific 
  individual sites. A method for PM sub 2.5 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 section 2.4.1, the requirements of Sec. 53.34 of this chapter 
  shall apply except 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; 
  when alternate seasons are approved by the Administrator.
  
      2.4.1.3 No PM sub 10 samplers shall be required for the test, as determination 
  of the PM sub 2.5/PM sub 10 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 greater than 40  mu g/m sup 3 for 24-hour 
  samples or greater than 15 mu g/m sub 3 average concentration collected over a 48-
  hour period.
  
      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 3 of 
  Appendix A of this part 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. {pg 38844}
  
      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 as required in section 2.4.1 
  through 2.4.1.4 of this Appendix.
  
      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.
  
      2.5 Approval of non-designated methods under Sec. 58.13(f). An automated 
  (continuous) method for PM sub 2.5 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 PM sub 2.5 monitoring data 
  obtained from such a monitor shall not be otherwise used for purposes of part 50 of 
  this chapter.
  
      * * * * *
  
      2.7.1 Requests for approval under sections 2.4, 2.6.2, or 2.8 of this Appendix 
  must be submitted to: Director, National Exposure Assessment Laboratory, Department 
  E, (MD-77B), U.S. Environmental Protection Agency, Research Triangle Park, North 
  Carolina 27711.
  
      * * * * *
  
      2.9 Use of IMPROVE Samplers at a SLAMS. "IMPROVE" samplers may be used in SLAMS 
  for monitoring of regional background and regional transport 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 PM sub 2.5 on three different 
  filter substrates that are compatible with a variety of analytical techniques, and 
  module D collects a PM sub 10 sample. PM sub 2.5 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 4, 5, and 6 of this Appendix).
  
      * * * * *
  
  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.
  
      n. Appendix D is amended by revising in the table of contents the entries for 
  2.8, 3.7, 4., and 5. and adding an entry for 6., by revising the first three 
  paragraphs and Table 1 of section 1., revising the second paragraph in section 2. 
  and adding a new paragraph to the end of the section before section 2.1, revising 
  section 2.8 and adding sections 2.8.0.1 through 2.8.2.3, revising the third and 
  fifth paragraphs in section 3., revising section 3.7 and adding sections 3.7.1 
  through 3.7.7.4, revising the sixth paragraph in section 4.2 and redesignating 
  Figures 1 and 2 as Figures 5 and 6 respectively, and revising the redesignated 
  figures, revising footnote 3 of Table 2 of section 4.4, revising section 5. and 
  reference 18 in section 6. to read as follows:
  
  Appendix D- Network Design for State and Local Air Monitoring Stations (SLAMS), 
  National Air Monitoring Stations (NAMS), and Photochemical Assessment Monitoring 
  Stations (PAMS)
  
      * * * * *
  
      2.8 Particulate Matter Design Criteria for SLAMS
  
      * * * * *
  
      3.7 Particulate Matter Design Criteria for NAMS
  
      4. Network Design for Photochemical Assessment Monitoring Stations (PAMS)
  
      5. Summary
  
      6. References
  
  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 PM sub 2.5. These criteria will also be used by EPA in 
  evaluating the adequacy of the SLAMS/NAMS/PAMS and core PM sub 2.5 networks.
  
      The network of stations that 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.
  
      (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 PM sub 2.5 are prescribed and the minimal network introduced in Sec. 
  58.20 is explained. The optimum size of a particular SLAMS network involves trade 
  offs among data needs and available resources that EPA believes can best be 
  resolved during the network design process.
  
      * * * * *
  
  
   Table  1.- Relationship Among Monitoring Objectives and Scale of
   Representativeness
   
   Monitoring Objective            Appropriate Siting Scales
   
   Highest concentration           Micro, Middle, neighborhood
                                   (sometimes urban fn 1 )
   Population                      Neighborhood, urban
   Source impact                   Micro, middle, neighborhood
   General/background              Neighborhood, urban, regional
   Regional transport              Urban/regional
   Welfare-related impacts         Urban/regional
   
   fn  fn 1 Urban denotes a geographic scale applicable to both
   cities and rural areas
   
   
  
      * * * * *
  
  2. SLAMS Network Design Procedures.
  
      * * * * *
  
      The discussion of scales in sections 2.3 through 2.8 of this Appendix does not 
  include all of the possible scales for each pollutant. The scales that are 
  discussed are those that 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 {pg 38845} screening studies, such as intensive studies conducted with 
  portable samplers, in designing networks. In many cases, in selecting sites for 
  core PM sub 2.5 or carbon monoxide SLAMS, and for defining the boundaries of PM sub 
  2.5 optional community monitoring zones, air pollution control agencies will 
  benefit from using such studies to evaluate the spatial distribution of pollutants.
  
      * * * * *
  
      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 section 6 
  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 references 17 and 18 of section 6 of 
  this Appendix 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 scales for PM sub 10 and neighborhood scales for both PM sub 10 and PM sub 
  2.5. 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. Most PM 
  sub 2.5 monitoring in urban areas should be representative of a neighborhood scale.
  
      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 
  coarse fraction particles (PM sub 10) is on this scale and on the neighborhood 
  scale; for fine particulate, much of the measurement is on the neighborhood scale. 
  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 exposure public health effects of particulate matter pollution. 
  In many situations, monitoring sites that are representative of micro-scale or 
  middle- scale impacts are not unique and are representative of many similar 
  situations. This can occur along traffic corridors or other locations in a 
  residential district. In this case, one location is representative of a 
  neighborhood of small scale sites and is appropriate for evaluation of long-term or 
  chronic effects. 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 PM sub 10, 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 PM sub 2.5 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. In general, most PM sub 2.5 monitoring in urban areas should have this 
  scale. A PM sub 2.5 monitoring location is assumed to be representative of a 
  neighborhood scale unless the monitor is adjacent to a recognized PM sub 2.5 
  emissions source or is otherwise demonstrated to be representative of a smaller 
  spatial scale by an intensive monitoring study. 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. Core PM sub 2.5 SLAMS may have this scale.
  
      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 PM sub 2.5, 
  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 PM sub 2.5 levels and may also be associated with 
  elevated ozone and regional haze.
  
      2.8.1 Specific Design Criteria for PM sub 2.5.
  
      2.8.1.1 Monitoring Planning Areas.
  
      Monitoring planning areas (MPAs) shall be used to conform to the community-
  oriented monitoring approach used for the PM sub 2.5 NAAQS given in part 50 of this 
  chapter. MPAs are required to correspond to all metropolitan statistical areas 
  (MSAs) with population greater than 200,000, and all other areas determined to be 
  in violation of the PM sub 2.5 NAAQS. fn 1 MPAs for other designated parts of the 
  State are optional. All MPAs shall be defined on the basis of existing, delineated 
  mapping data such as State boundaries, county boundaries, zip codes, census blocks, 
  or census block groups.
  
  fn 1 The boundaries of MPAs do not have to necessarily correspond to those of MSAs 
  and existing intra or interstate air pollution planning districts may be utilized.
  
      2.8.1.2 PM sub 2.5 Monitoring Sites within the State's PM Monitoring Network 
  Description.
  
      2.8.1.2.1 The minimum required number, type of monitoring sites, and sampling 
  {pg 38846} requirements for PM sub 2.5 are based on monitoring planning areas 
  described in the PM monitoring network description and proposed by the State in 
  accordance with Sec. 58.20.
  
      2.8.1.2.2 Comparisons to the PM sub 2.5 NAAQS may be based on data from SPMs in 
  addition to SLAMS (including NAMS, core SLAMS and collocated PM sub 2.5 sites at 
  PAMS), that meet the requirements of Sec. 58.13 and Appendices A, C and E of this 
  part, that are included in the PM monitoring network description. For comparison to 
  the annual NAAQS, the monitors should be neighborhood scale community-oriented 
  locations. Special purpose monitors that meet part 58 requirements will be exempt 
  from NAAQS comparisons with the PM sub 2.5 NAAQS for the first 2 calendar years of 
  their operation to encourage PM sub 2.5 monitoring initially. After this time, 
  however, any SPM that records a violation of the PM sub 2.5 NAAQS must be seriously 
  considered as a potential SLAMS site during the annual SLAMS network review in 
  accordance with Sec. 58.25. If such SPMs are not established as a SLAMS, the agency 
  must document in its annual report the technical basis for excluding it as a SLAMS.
  
      2.8.1.2.3 The health-effects data base that served as the basis for selecting 
  the new PM sub 2.5 standards relied on a spatial average approach that reflects 
  average community-oriented area-wide PM exposure levels. Under this approach, the 
  most effective way to reduce total population risk is by lowering the annual 
  distributions of ambient 24-hour PM sub 2.5 concentrations, as opposed to 
  controlling peak 24-hour concentrations on individual days. The annual standard 
  selected by EPA will generally be the controlling standard for lowering both short- 
  and long-term PM sub 2.5 concentrations on an area-wide basis and will achieve this 
  result. In order to be consistent with this rationale, therefore, PM sub 2.5 data 
  collected from SLAMS and special purpose monitors that are representative, not of 
  area-wide but rather, of relatively unique population-oriented microscale, or 
  localized hot spot, or unique population-oriented middle-scale impact sites are 
  only eligible for comparison only to the 24-hour PM sub 2.5 NAAQS. However, in 
  instances where certain population-oriented micro- or middle-scale PM sub 2.5 
  monitoring sites are determined by the EPA Regional Administrator to collectively 
  identify a larger region of localized high ambient PM sub 2.5 concentrations, data 
  from these population-oriented sites would be eligible for comparison to the annual 
  NAAQS.
  
      2.8.1.2.4 Within each MPA, the responsible air pollution control agency shall 
  install core SLAMS, other required SLAMS and as many PM sub 2.5 stations judged 
  necessary to satisfy the SLAMS requirements and monitoring objectives of this 
  Appendix.
  
      2.8.1.3 Core Monitoring Stations for PM sub 2.5.
  
      Core monitoring stations or sites are a subset of the SLAMS network for PM sub 
  2.5 that are sited to represent community-wide air quality. These core sites 
  include sites to be collocated at PAMS.
  
      2.8.1.3.1 Within each monitoring planning area, the responsible air pollution 
  control agency shall install the following core PM sub 2.5 SLAMS:
  
      (a) At least two core PM sub 2.5 SLAMS per MSA with population greater than 
  500,000 sampling everyday, unless exempted by the Regional Administrator, including 
  at least one station in a population-oriented area of expected maximum 
  concentration and at least one station in an area of poor air quality and at least 
  one additional core monitor collocated at a PAMS site if the MPA is also a PAMS 
  area fn 2.
  
  fn 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 PM sub 2.5 network.
  
      (b) At least one core PM sub 2.5 SLAMS per MSA with population greater than 
  200,000 and less than or equal to 500,000 sampling every third day.
  
      (c) Additional core PM sub 2.5 SLAMS per MSA with population greater than 1 
  million, sampling every third day, as specified in the following table:
  
  
   Table  1.- Required Number of Core SLAMS According to MSA
   Population
   
   MSA Population       Minimum Required No. of Core
                        Sites fn 1
   
   >1 M                 3
   >2 M                 4
   >4 M                 6
   >6 M                 8
   >8 M                 10
   
   fn  1 Core SLAMS at PAMS are in addition to these numbers.
   
   
  
      2.8.1.3.2 The site situated in the area of expected maximum concentration is 
  analogous to NAMS "category a."  fn3 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." This second site will be called a category b core SLAMS site.
  
  fn 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 category "a" 
  core SLAMS monitors.
  
      2.8.1.3.3 Those MPAs that are substantially impacted by several different and 
  geographically disjoint local sources of fine particulate should have separate core 
  sites to monitor each influencing source region.
  
      2.8.1.3.4 Within each monitoring planning area, one or more required core SLAMS 
  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 
  core monitor for PM sub 2.5 is included in a MPA or optional CMZ, however, a 
  "category a" core site is strongly preferred to determine community- oriented PM 
  sub 2.5 concentrations in areas of high average PM sub 2.5 concentration.
  
      2.8.1.3.5 More than the minimum number of core SLAMS should be deployed as 
  necessary in all MPAs. Except for the core SLAMS described in section 2.8.1.3.1 of 
  this Appendix, the additional core SLAMS must only comply with the minimum sampling 
  frequency for SLAMS specified in Sec. 58.13(e).
  
      2.8.1.3.6 A subset of the core PM sub 2.5 SLAMS shall be designated NAMS as 
  discussed in section 3.7 of this Appendix. The selection of core monitoring sites 
  in relation to MPAs and CMZs is discussed further in section 2.8.3 of this 
  Appendix.
  
      2.8.1.3.7 Core monitoring sites shall represent neighborhood or larger spatial 
  scales. A monitor that is established in the ambient air that is in or near a 
  populated area, and meets appropriate 40 CFR part 58 criteria (i.e., meets the 
  requirements of Sec. 58.13 and Sec. 58.14, Appendices A, C, and E of this part) can 
  be presumed to be representative of at least a neighborhood scale, is eligible to 
  be called a core site and shall produce data that are eligible for comparison to 
  both the 24-hour and annual PM sub 2.5 NAAQS. If the site is adjacent to a 
  dominating local source or can be shown to have average 24-hour concentrations 
  representative of a smaller spatial scale, then the site would only be compared to 
  the 24-hour PM sub 2.5 NAAQS.
  
      2.8.1.3.8 Continuous fine particulate monitoring at core SLAMS. At least one 
  continuous fine particulate analyzer (e.g., beta attenuation analyzer; tapered- 
  element, oscillating microbalance (TEOM); transmissometer; nephelometer; or other 
  acceptable continuous fine particulate monitor) shall be located at a core 
  monitoring PM sub 2.5 site in each metropolitan area with a population greater than 
  1 million. These analyzers shall be used to provide improved temporal resolution to 
  better understand the processes and causes of elevated PM sub 2.5 concentrations 
  and to facilitate public reporting of PM sub 2.5 air quality and will be in 
  accordance with appropriate methodologies and QA/QC procedures approved by the 
  Regional Administrator.
  
      2.8.1.4 Other PM sub 2.5 SLAMS Locations.
  
      In addition to the required core sites described in section 2.8.1.3 of this 
  Appendix, the State shall also install and operate on an every third day sampling 
  schedule at least one SLAMS to monitor for regional background and at least one 
  SLAMS to monitor regional transport. These monitoring stations may be at a 
  community-oriented site and their requirement may be satisfied by a corresponding 
  SLAMS monitor in an area having similar air quality in another State. The State 
  shall also be required to establish additional SLAMS sites based on the total 
  population outside the MSA(s) associated with monitoring planning areas that 
  contain required core SLAMS. There shall be one such additional SLAMS for each 
  200,000 people. The minimum number of SLAMS may be deployed anywhere in the State 
  to satisfy the SLAMS monitoring objectives including monitoring of small scale 
  impacts which may not be community-oriented or for regional transport as described 
  in section 1 {pg 38847} of this Appendix. Other SLAMS may also be established and 
  are encouraged in a State PM sub 2.5 network.
  
      2.8.1.5 Additional PM sub 2.5 Analysis Requirements.
  
      (a) Within 1 year after September 16, 1997, chemical speciation will be 
  required at approximately 25 PM sub 2.5 core sites collocated at PAMS sites (1 type 
  2 site per PAMS area) and at approximately 25 other core sites for a total of 
  approximately 50 sites. The selection of these sites will be performed by the 
  Administrator in consultation with the Regional Administrator and the States. 
  Chemical speciation is encouraged at additional sites. At a minimum, chemical 
  speciation to be conducted will include analysis for elements, selected anions and 
  cations, and carbon. Samples for required speciation will be collected using 
  appropriate monitoring methods and sampling schedule in accordance with procedures 
  approved by the Administrator.
  
      (b) Air pollution control agencies shall archive PM sub 2.5 filters from all 
  other SLAMS sites for a minimum of one year after collection. 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 for PM sub 2.5. The 
  filters shall be archived in accordance with procedures approved by the 
  Administrator.
  
      2.8.1.6 Community Monitoring Zones.
  
      2.8.1.6.1 The CMZs describe areas within which two or more core monitors may be 
  averaged for comparison with the annual PM sub 2.5 NAAQS. This averaging approach 
  as specified in 40 CFR part 50, Appendix N, is directly related to epidemiological 
  studies used as the basis for the PM sub 2.5 NAAQS. A CMZ should characterize an 
  area of relatively similar annual average air quality (i.e., the average 
  concentrations at individual sites shall 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 0.6). Moreover, the entire 
  CMZ should principally be affected by the same major emission sources of PM sub 
  2.5.
  
      2.8.1.6.2 Each monitoring planning area may have at least one CMZ, that may or 
  may not cover the entire MPA. In metropolitan statistical areas (MSAs) for which 
  MPAs are required, the CMZs may completely cover the entire MSA. When more than one 
  CMZ is described within an MPA, CMZs shall not overlap in their geographical 
  coverage. All areas in the ambient air may become a CMZ.
  
      2.8.1.6.3. As PM sub 2.5 networks are first established, core sites would be 
  used individually for making comparisons to the annual PM sub 2.5 NAAQS. As these 
  networks evolve, individual monitors may not be adequate by themselves to 
  characterize the annual average community wide air quality. This is especially true 
  for areas with sharp gradients in annual average air quality. Therefore, CMZs with 
  multiple core SLAMS or other eligible sites as described in accordance with section 
  2.8.1.2 to this Appendix, may be established for the purposes of providing improved 
  estimates of community wide air quality and for making comparisons to the annual 
  NAAQS. This CMZ approach is subject to the constraints of section 2.8.1.6.1 to this 
  Appendix.
  
      2.8.1.6.4 The spatial representativeness of individual monitoring sites should 
  be considered in the design of the network and in establishing the boundaries of 
  CMZs. Communities within the MPA with the highest PM sub 2.5 concentrations must 
  have a high priority for PM sub 2.5 monitoring. Until a sufficient number of 
  monitoring stations or CMZs are established, however, the monitored air quality in 
  all parts of the MPA may not be precisely known. It would be desirable, however, to 
  design the placement of monitors so that those portions of the MPAs without 
  monitors could be characterized as having average concentrations less than the 
  monitored portions of the network.
  
      2.8.1.7 Selection of Monitoring Locations Within MPAs or CMZs.
  
      2.8.1.7.1 Figure 1 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 2 of this Appendix shows the same hypothetical 
  MPA as Figure 1 of this Appendix and illustrates potential community monitoring 
  zones and the location of core monitoring sites within them. Figure 3 of this 
  Appendix illustrates which sites within the CMZs of the same MPA may be used for 
  comparison to the PM sub 2.5 NAAQS.
  
      2.8.1.7.2 In Figure 1 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. The monitoring area should have at least one core 
  monitor to represent community wide air quality in each sub-area affected by 
  different emission sources. Each monitoring planning area with population greater 
  than 500,000 is required to have at least two core population-oriented monitors 
  that will sample everyday (with PAMS areas requiring three) and may have as many 
  other core SLAMS, 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. C sub a denotes "category a" core SLAMS site (community-oriented 
  site in area of expected maximum concentration); it is shown within the populated 
  area and closest to the area with highest concentration. C sub b 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). P 
  denotes a Special Purpose Monitor (a specialized monitor that, for example, may use 
  a non-reference sampler). Finally, note that all SPMs would be subject to the 2-
  year moratorium against data comparison to the NAAQS for the first 2 complete 
  calendar years of its operation.
  
      2.8.1.7.3 A Monitoring Planning Area may have one or more community monitoring 
  zones (CMZ) for aggregation of data from eligible SLAMS and SPM sites for 
  comparison to the annual NAAQS. The planning area has large gradients of average 
  air quality and, as shown in Figure 2 may be assigned three CMZs: 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 appropriate).
  
  {SEE ILLUSTRATION(S) IN ORIGINAL DOCUMENT}
  
      2.8.1.7.4 Figure 3 of this Appendix illustrates how CMZs and PM sub 2.5 
  monitors might be located in a hypothetical MPA typical of a Western State. Western 
  States with more localized sources of PM and larger geographic area could require a 
  different mix {pg 38849} of SLAMS and SPM monitors and may need more total 
  monitors. 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 MPAs and CMZs may not 
  cover the entire State.
  
  {SEE ILLUSTRATION(S) IN ORIGINAL DOCUMENT}
  
      2.8.1.7.5 Figure 4 of this Appendix shows how the MPAs, CMZs, and PM sub 2.5 
  monitors might be distributed within a hypothetical State. Areas of the State 
  included within MPAs are shown within heavy solid lines. Two MPAs are illustrated. 
  Areas in the State outside the MPAs will also include monitors, but this monitoring 
  coverage may be limited. This portion of the State may also be represented by CMZs 
  (shown by areas enclosed within dotted lines). The monitors that are intended for 
  comparison to the NAAQS are indicated by X. Furthermore, eligible monitors within a 
  CMZ could be averaged for comparison to the annual NAAQS or examined individually 
  for comparison to both NAAQS. Both within the MPAs and in the remainder of the 
  State, some special study monitors might not satisfy applicable 40 CFR part 58 
  requirements and will not be eligible for comparison to the NAAQS.
  
  {SEE ILLUSTRATION(S) IN ORIGINAL DOCUMENT}
  
      2.8.2 Substitute PM Monitoring Sites.
  
      2.8.2.1 Section 2.2 of Appendix C of this part describes conditions under which 
  TSP samplers can be used as substitutes for PM sub 10. This provision is intended 
  to be used when PM sub 10 concentrations are expected to be very low and substitute 
  TSP samplers can be used to satisfy the minimum number of PM sub 10 samplers needed 
  for an adequate PM sub 10 network.
  
      2.8.2.2 If data produced by substitute PM samplers exceed the concentration 
  levels described in Appendix C of this part, then the need for this sampler to be 
  converted to a PM sub 10 or PM sub 2.5 sampler, shall be considered in the PM 
  monitoring network review. If the State does not believe that a PM sub 10 or PM sub 
  2.5 sampler should be sited, 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 network description, then high concentrations 
  at this site would not necessarily cause this site to become a PM sub 2.5 or PM sub 
  10 site, whichever is indicated.
  
      2.8.2.3 Consistent with Sec. 58.1, combinations of SLAMS PM sub 10 or PM sub 
  2.5 monitors and other monitors may occupy the same structure without any mutual 
  effect on the regulatory definition of the monitors.
  
  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 PM sub 2.5, neighborhood scale for SO2, and NO2, and 
  urban scale for O sub 3.
  
      * * * * *
  
      For each MSA where NAMS are required, both categories of monitoring stations 
  must be established. In the case of SO sub 2 if only one NAMS is needed, then 
  category (a) must be used. The analysis and interpretation of data from NAMS should 
  consider the distinction between these types of stations as appropriate.
  
      * * * * *
  
      3.7 Particulate Matter Design Criteria for NAMS.
  
      3.7.1 Table 4 indicates the approximate number of permanent stations required 
  in MSAs to characterize national and regional PM sub 10 air quality trends and 
  geographical patterns. The number of PM sub 10 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 PM sub 2.5, the number of PM sub 10 
  SLAMS is expected to decrease, but requirements to maintain PM sub 10 NAMS remain 
  in effect. The PM sub 10 NAMS are retained to provide trends data, to support 
  national assessments and decisions, and in some cases to continue demonstration 
  that a NAAQS for PM sub 10 is maintained as a requirement under a State 
  Implementation Plan.
  
      3.7.3 The PM sub 2.5 NAMS shall be a subset of the core PM sub 2.5 SLAMS and 
  other SLAMS intended to monitor for regional transport. The PM sub 2.5 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 one PM sub 2.5 NAMS stations.
  
      3.7.4 The number of total PM sub 2.5 NAMS per Region will be based on 
  recommendations of the EPA Regional Offices, in concert with {pg 38851} their State 
  and local agencies, in accordance with the network design goals described in 
  sections 3.7.5 through 3.7.7 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 for PM sub 2.5 NAMS is intended to 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 PM sub 2.5 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 PM sub 10 NAMS.
  
      3.7.6 States will be required to establish approximately 50 NAMS sites for 
  routine chemical speciation of PM sub 2.5. These sites will include those 
  collocated at approximately 25 PAMS sites and approximately 25 other core SLAMS 
  sites to be selected by the Administrator. After 5 years of data collection, the 
  Administrator may exempt some sites from collecting speciated data. The number of 
  NAMS sites at which speciation will be performed each year and the number of 
  samples per year will be determined by the Administrator.
  
      3.7.7 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 
  MSAs 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 ensure 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.- PM sub 10  National Air Monitoring Station Criteria
   
    Approximate Number of Stations per MSA  fn 1
   Population      High            Medium          Low
   Category        Concentration   Concentration   Concentration
                   fn 2            fn 3            fn 4
   
   >1,000,000      6-10            4-8             2-4
   500,000-        4-8             2-4             1-2
   1,000,000
   250,000-        3-4             1-2             0-1
   500,000
   100,000-        1-2             0-1             0
   250,000
   
   fn  1 Selection of urban areas and actual number of stations per
   area will be jointly determined by EPA and the State agency.
   
   fn  2 High concentration areas are those for which ambient PM sub
   10 data show ambient concentrations exceeding either PM sub 10
   NAAQS by 20 percent or more.
   
   fn  3 Medium concentration areas are those for which ambient PM
   sub 10 data show ambient concentrations exceeding 80 percent of
   the PM sub 10 NAAQS.
   
   fn  4 Low concentration areas are those for which ambient PM sub
   10 data show ambient concentrations less than 80 percent of the
   PM sub 10 NAAQS.
   
   
  
      3.7.7.1 Selection of urban areas and actual number of stations per area will be 
  jointly determined by EPA and the State agency.
  
      3.7.7.2 High concentration areas are those for which: Ambient PM sub 10 data 
  show ambient concentrations exceeding either PM sub 10 NAAQS by 20 percent or more.
  
      3.7.7.3 Medium concentration areas are those for which: Ambient PM sub 10 data 
  show ambient concentrations exceeding either 80 percent of the PM sub 10 NAAQS.
  
      3.7.7.4 Low concentration areas are those for which: Ambient PM sub 10 data 
  show ambient concentrations less than 80 percent of the PM sub 10 NAAQS.
  
  
   Table  5.- Goals for Number of PM sub 2.5  NAMS by Region
   
   EPA Region            Number of NAMS fn 1   Percent of National
                                               Total
   
   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
   
   fn 1 Each region will have one to three NAMS having the
   monitoring of regional transport as a primary objective.
   
   
  
      * * * * *
  
      4.2 PAMS Monitoring Objectives.
  
      * * * * *
  
      States choosing to submit an individual network description for each affected 
  nonattainment area, irrespective of its proximity to other affected areas, must 
  fulfill the requirements for isolated areas as described in section 4 of this 
  Appendix, as an example, and illustrated by Figure 5. States containing areas which 
  experience significant impact from long-range transport or are proximate to other 
  nonattainment areas (even in other States) should collectively submit a network 
  description which contains alternative sites to those that would be required for an 
  isolated area. Such a submittal should, as a guide, be based on the example 
  provided in Figure 6, but must include a demonstration that the design satisfies 
  the monitoring data uses and fulfills the PAMS monitoring objectives described in 
  sections 4.1 and 4.2 of this Appendix.
  
  {SEE ILLUSTRATION(S) IN ORIGINAL DOCUMENT}
  
      * * * * *
  
      4.4 Minimum Monitoring Network Requirements.
  
      * * * * *
  
      Table 2 * * *
  
       fn3See Figure 5.
  
      * * * * *
  
  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
   
   Spatial Scale           Scales Applicable for SLAMS
                  SO sub 2     CO         O sub 3     NO sub 2
   
   Micro                       check
   Middle         check        check      check       check
   Neighborhood   check        check      check       check
   Urban          check                   check       check
   Regional       check                   check
   
   (6)Scales Required for NAMS
   Micro                       check
   Middle
   Neighborhood   check        check      check       check
   Urban                                  check       check
   Regional
   
   Spatial Scale            Scales Applicable for SLAMS
                   Pb              PM sub 10       PM sub 2.5
   
   Micro           check           check           check
   Middle          check           check           check
   Neighborhood    check           check           check
   Urban           check           check           check
   Regional        check           check           check
   
                    (6)Scales Required for NAMS
   Micro           check           check           check fn 1
   Middle          check           check           check fn 1
   Neighborhood    check           check           check
   Urban                                           check fn 2
   Regional                                        check fn 2
   
   fn 1 Only permitted if representative of many such micro-scale
   environments in a residential district (for middle scale, at
   least two).
   
   fn 2 Either urban or regional scale for regional transport sites.
   
   
  6. References.
  
      * * * * *
  
      18. Watson et al. Guidance for Network Design and Optimum Site Exposure for PM 
  sub 2.5 and PM sub 10. Prepared for U.S. Environmental Protection Agency, Research 
  Triangle Park, NC.
  
      o. Appendix E is amended by revising the entry for 8. in the table of contents, 
  by revising the heading to section 8., adding a sentence at the end of the first 
  paragraph of section 8.1, and in section 8.3 removing the term "PM sub 10" wherever 
  it appears and adding in its place "PM" to read as follows:
  
  Appendix E-Probe and Monitoring Path Siting Criteria for Ambient Air Quality 
  Monitoring
  
      * * * * *
  
      8. Particulate Matter (PM sub 10 and PM sub 2.5)
  
      * * * * *
  
  8. Particulate Matter (PM sub 10 and PM sub 2.5).
  
      8.1 Vertical Placement * * * Although microscale or middle scale stations are 
  not the preferred spatial scale for PM sub 2.5 sites, there are situations where 
  such sites are representative of several locations within an area where large 
  segments of the population may live or work (e.g., central business district of 
  Metropolitan area). In these cases, the sampler inlet for such microscale PM sub 
  2.5 stations must also be 2-7 meters above ground level.
  
      * * * * *
  
      p. Appendix F is amended by revising in the table of contents the entry for 
  2.7.3 and adding a new entry for 2.7.4, by redesignating section 2.7.3 as section 
  2.7.4 and adding a new section 2.7.3 to read as follows:
  
  Appendix F-Annual SLAMS Air Quality Information
  
      * * * * *
  
      2.7.3 Annual Summary Statistics
  
      2.7.4 Episode and Other Unscheduled Sampling Data
  
      * * * * *
  
      2.7.3 Annual Summary Statistics. Annual arithmetic mean ( mu g/m sup 3) as 
  specified in 40 CFR part 50, Appendix N. 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:
  
  
   Range                           Number of Values
   
   0 to 15 ( mu g/m fn 3)
   16 to 30
   31 to 50
   51 to 70
   71 to 90
   91 to 110
   Greater than 110
   
  
  INTERNAL DATA:  FR Doc. 97-18579; Filed 7-17-97; 8:45 am; BILLING CODE 6560-50-F