# '~IEPA United Slates Environmental Protection Agency OffiCe ofAirQuality Planning and Standards ResearchTrianglePark. NC 27711 EPA-452/R-93-008 April**~993**

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# PM-lO GUIDELINE DOCUMENT

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## @**Print~d**on RecycledPaper

## PM-lO GUIDELINE DOCUMENT



# u.s. Environmental Protection Agency Office ofAir and Radiation 

### Office ofAir Quality Planning and Standards Research Triangle Park, Nonh Carolina 277 11 April 1993 EPA-452/R-93

-008

### TABLE OF CONTENTS Section Page ListofReferences
...... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Vlll 

### List ofTables
.. .. .. ......... ...... ..... ..... . ...... ................ x 1.0 Introduction.
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . " 1·1 1.1 Overview
................. . ............................ 1·1 1.2 Provisions for Updating the Guideline
.......................... 1·3 1.3 Additional Information Sources
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 1·3 2.0 State Implementation Plans
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2·1 2.1 General
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 2·1 2.2 General SIPApproach
.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-4 2.3 Statutory Requirements for PM-I0 SIP's
........................ 2-7 3.0 Detennining Air 

### Quality Status
............................ .. . ... " 3-1 3.1 Section 107 Designations
.......... . ..................... ... 3-1 3.1.1 General
................................ ..... . .... 3·1 3.1.2 Designating Areas as Nonattainment
. . . . . . . . . . . . . . . . . . . . . . 3-1 3.1.3 Area Boundaries
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-2 3.1.4 Redesignating Areas to Attainment
....................... 3-2 3.2 Ambient Air
........... . .......... ..... ... ...... .. ..... 3-13 3.2.1 General.....................................
.... 3-13 3.2.2 Location Aspects
.................................. 3-13 3.2.3 Time Aspects ., ........... . ....................... 3·14 3.2.4 Public Access
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 3·14 3.2.5 PSD Considerations.
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 3-14 3.2.6 Land Acquisition
.................................. 3-15 3.2.7 Monitor Siting Location Considerations
................... 3-15 4
.0 Emission Inventories
. ..... .... ... ... ...... ... .................. 4-1 5.0 Ambient Air Quality Monitoring and Data Usage
....................... 5-1 5.1 General.
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-1 5.2 Quality Assurance
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-5 5.3 Ambient Monitoring Methodology.
. . . . . . . . . . . . . . . . . . . . . . . . . . .. 5-8 5.3.1 General
.................................... - -...... 5-8 5.3.2 Sampling Schedule
.................................. 5-9 5.3.3 Data Completeness
. ................................ 5·10 5.4 Network Design
........................................ 5-13 5.5 Probe Siting Criteria
..................................... 5-19 ii 

### April 1993TABLE OF CONTENTS (Continued) Section Page
5.6 Episode Monitoring
...................................... 5-22 5.7 Ambient 

### Air Quality Data Reporting
.......................... 5-24 5.7.1 General
......................................... 5-24 5.7.2 

### Air Pollution Index
................................. 5-25 5.7.3 Exceptional Events
................................. 5-25 6.0 

### Air Quality Modeling
........................................... 6-1 6.1 General
.......................................... _. . . . . 6-1 6.2 Guidance on Air Quality Models
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-4 6.3 Model Selection
.......................................... 6-7 6.4 Meteorological Input
..................................... 6-11 6.5 Source Input
........................................... 6-15 6.5.1 General
......................................... 6-15 6.5.2 Allowable Versus Actual Emissions
. . . . . . . . . . . . . . . . . . . . .. 6-15 6.5.3 Area Sources
..................................... 6-16 6.5.4 Background Concentration
............................ 6-16 6.5.5 Stack Height Inputto Air Quality Modeling
. . . . . . . . . . . . . . .. 6-17 6.5.6 Stack Downwash and Building Wake Effects
............... 6-18 6.6 Receptor Analysis
....................................... 6-22 6.7 Other Model Requirements
................................. 6-24 6.7.1 Stagnation
....................................... 6-24 6.7.2 Fumigation
....................................... 6-24 6.7.3 Long Range Transport
............................... 6-25 6.7.4 Settling and Deposition
.............................. 6-25 6.7.5 Model Limitations.
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 6-25 6.8 Receptor Modeling
...................................... 6-28 7.0 StackHeight Regulations
........................................ 7-1 7.1 General Regulations
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-1 7.2 Good Engineering Practice Stack Height
........................ 7-3 7.2.1 General
.......................................... 7-3 7.2.2 Definition of "Nearby" for GEP
......................... 7-4 7.2.3 Definition of "Excessive Concentration"
.................... 7-4 7.3 Dispersion Techniques
.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 7-6 7.3.1 General
.......................................... 7-6 7.3.2" Prohibitions
....................................... 7-6 7.3.3 Exceptions........................................ 7-6 7.4 Remanded Regulations
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-8

III April 1993

### TABLE OF CONTENTS (Continued) Section Page
7.5 Specific Stack Height Policies
............................... 7-10 7.5.1 Definition of "In 

### Existence"
............... . ........... 7-10 7.5.2 Tie-ins to Existing Stacks
............................. 7-11 7.6 Demonstrations byFluid Modeling, Field Studies or Nuisance
........ 7-13 7.6.1 Applicability
...................................... 7-13 7.6.2 Field Studies
..................................... 7-13 7.6.3 Fluid Modeling
.................................... 7-14 7.6.4 Emission Rate for Physical Demonstrations
................ 7-14 7.6.5 Not in Ambient Air
................................. 7-15 7.6.6 Additional Guidance
................................ 7-15 7.7 Merged Stacks
......................................... 7-20 7.7.1 General
........"
................................. 7-20 7.7.2 Exceptions
....................................... 7-20 7.8 Stack Height Negative Declarations
........................... 7-23 7.8.1 General
......................................... 7-23 7.8.2 Infonnation Needed
................................. 7-23 7.8.3 Modeling Needed
.................................. 7-23 8.0 Control Strategies
............................................. 8-1 8.1 General.
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 8-1 8.2 Control Strategy Transition
.................................. 8-3 8.3 Establishing Emission Limitations
. . . . . . . . . . . . . . . . . . . . . . . . . . . .. 8-5 8.3.1 General
.......................................... 8-5 8.3.2 Design Concentrations
................................ 8-5 8.3.3 Averaging Periods
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-6 8.3.4 Compliance Methods
................................. 8-7 8.4 Control Methods for PM-lO Sources
...... . . . . . . . . . . . . . . . . . . .. 8-10 8.4.1 RACMIBACM Issuance
.................. . ........... 8-10 8.4.2 RACM/BACM SIP Requirement.
. . . . . . . . . . . . . . . . . . . . . .. 8-10 8.4.3 Determining RACM/RACT
........................... 8-10 8.4.4 PM-lO Precursors
.................................. 8-11 8.4.5 Condensible PM-lO
.........................'
. . . . . . .. 8-13 8.4.6 Control Measures Available for Fugitive DustRACM
. . . . . . . .. 8-13 8.4.7 Control Measures Available for Residential Wood Combustion RACM
.......................................... 8-14 8.4.8 Control Measures Available for Prescribed Burning RACM 8-16 8.4.9 RACfDetermination for Stationary Sources
............... 8-17

IV 

### April 1993TABLE OF CONTENTS (Continued) Section Page 

### 9.0 General Provisions
............................................. 9-1 9.1 General
............................................... 9-1 9.2 Clean Air

### Act Requirements: Tune Frames and PM-lO NAAQS SIP Requirements
........................................... 9-3 9.2.1 Designations....................................... 9-3 9.2.2 Classification
...................................... 9-3 9.2.3 Attainment Dates
................................... 9-4 9.2.4 Plan Submission
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 9-5 9.3 Current NAAQS and PSD Program
........................... 9-13 9.3.1 National Ambient Air 

### Quality Standards
.................. 9-13 9.3.2 Prevention ofSignificantDeterioration Program
.. . . . . . . . . . .. 9-13 9.4 SIP Revisions
.......................................... 9-16 9.4.1 General
......................................... 9-16 9.4.2 SIP Completeness
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 9-16 9.4.3 Approval Options
.................................. 9-17 9.4.4 Grandfathering
.................................... 9-18 9.4.5 SIP Relaxations
................................... 9-19 9.4.6 SIP Tightening
................................... 9-19 9.5 Sanctions and FIP Requirements
............................. 9-26 9.5.1 Actions Triggering Sanctions and FIP Requirements
.......... 9-26 9.5.2 Sanction and FIP Clocks
............................. 9-26 9.5.3 Available Sanctions
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 9-27 9.6 Interim Control Strategies
.................................. 9-31 9.7 SIP Calls
... . . ... ..... ............................... 9-33 10
..0 PermitRequirements
.......................................... 10-1 10.1 General
.............................................. 10-1 10.2 Nonattainment Areas
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 10-3 10.2.1 Applicability.
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 10-3 10.2.2 Control Technology Requirements
....................... 10-3 10.2.3 Emission Offsets
................................... 10-3 10.2.4 NetAir Quality Benefit
. . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 10-4 10.2.5 Other Requirements
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 10-4 10.2.6 NSR Transition
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 10-4 10.3 PSD Areas
.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 10-11 10.3.1 Applicability.
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 10-11 10.3.2 Control Technology Requirements
. . . . . . . . . . . . . . . . . . . . .. 10-11 10.3.3 Air Quality Analysis
.. . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 10-11 10.3.4 Other Impacts.
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 10-12

v 

### April 1993TABLE OF CONTENTS (Continued) Section Page
10.3.5 Class I Areas
.................................... 10-13 10.4 SIPPermitRequirements
.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 10-15 10.5 Visibility
............................................ 10-17 10.6 Emissions Trading
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 10-18 10.6.1 General Policy Aspects
............................. 10-18 10.6.2 Bubbling
....................................... 10-18 10.6.3 Netting
........................................ 10-18 10.6.4 Offsets.
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 10-19 10.6.5 Banking
........................................ 10-19 10.6.6 Emission Reduction Credits
.......................... 10-19 10.7 PM-lO Specific Policy Aspects
. . . . . . . . . . . . . . . . . . . . . . . . . . . .. 10-21 11.0 Compliance and Enforcement
.................................... 11-1 11.1 General.............................................. 11-1 11.2 Enforceability Criteria
.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 11-1 11.3 Continuous Compliance
................................... 11-5 11.3.1 General
......................................... 11-5 11.3.2 EnforcementDiscretion Approach
....................... 11-5 11.3.3 Malfunctions and Unusual Start-up or Shut-down
.. . . . . . . . . .. 11-6 11.4 Compliance Monitoring
. . ................................ 11-8 ll.4.1 Compliance Monitoring Strategy
. . . . . . . . . . . . . . . . . . . . . . .. 11-8 11.4.2 Compliance Monitoring Requirements
. . . . . . . . . . . . . . . . . . .. 11-8 11.4.3 State Inspection Plan Submittal
. . . . . . . . . . . . . . . . . . . . . . . .. 11-9 11.4.4 Negotiated Inspection Plans
.......................... 11-10 11.5 Compliance Plans/Schedules.
. . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 11-13 11.6 Compliance Testing Methods
.............................. 11-13 12.0 New Source Performance Standards
............................... 12-1 12.1 General
.............................................. 12-1 12.2 NSPS Provisions for Particulate Matter
........................ 12-4 12.2.1 Subpart D--Fossil-Fuel Fired Steam Generators
............. 12-4 12.2.2 Subpart Da--Electric Utility Steam Generating Units
. . . . . . . . .. 12-4 12.2.3 Subpart Db--Industrial-Conunercial-Institutional Steam Generating Units.
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 12-5 12.2.4 SubpartI--Petroleum Refineries
........................ 12-6 12.2.5 SubpartL--Secondary Lead Smelters
..'
................... 12-6 12.2.6 SubpartP--Primary Copper Smelters
..................... 12-6 12.2.7 Subpart Q--Primary Zinc Smelters
....................... 12-7 12.2.8 SubpartR--Primary Lead Smelters
...................... 12-7 vi April 1993

### TABLE OF CONTENTS (Continued) Section Page 12.2.9 Subpart AAA--New Residential Wood Heaters
.............. 12-8 12.3 ModificationlReconstruction Provisions
....................... 12-10 Appendix A. Referenced Materials ., ....................................A-I Appendix B. Compendium ofInformation Sources on PM-lO Policy and Guidance
.... B-1

Vll 

### April 1993

### LIST OF REFERENCES Subject Page References for Section 2.1
. . . ..... .. .. . . .... .. ... ... . ... ..... . . . ... ... 2-3 References for Section 2.2
............................................ 2-6 References for Section 2.3
............................................ 2-9 References for Section 3.1
.. .... .. .... . . ... ... . .. . . . ... .. .. . . . . . . ..... 3-6 References for Section 3.2
........................................... 3-16 References for Section 5.1
........................................... . 5-3 References for Section 5.2
............ .. .............................. 5-7 References for Section 5.3
............................... . ........... 5-11 References for Section 5.4
........................................... 5-16 References for Section 5.5
... ... .. . ..... ... . .... .. . .. .... . . . .. . .... .. 5-20 References for Section 5.6
............. . .............................. 5-23 References for Section 5.7
........................................... 5-27 References for Section 6.1
. .... . . . . . . . . ... . ......... . .. . ......... . . . .. 6-2 References for Section 6.2
............... . ............................ 6-5 References for Section 6.3
.................. . ........ . ................ 6-9 References for Section 6.4
....... . ........ . . . .... . .. .. . ... .... . .... .. 6-13 References for Section 6.5
................................ . ... . ...... 6-19 References for Section 6.6
........ . .................................. 6-23 References for Section 6.7
. . . . . . . . ... . . . ..... . . .. . .......... ..... . . . . 6-26 References for Section 6.8
. . . . . . ... .. . . ... ...... . ...... . . .. . ... . .. ... 6-31 References for Section 7.1
. . . . .. . . . . . .... . ... . . .'
.. . ........ ..... . . . . .. 7-2 References for Section 7.2
... . . ... .. .... .. . . .. . ... . ..... .... .. . . . .. .. . 7-5 References for Section 7.3
. . .. . . ...... . .... .... .. .... . .. . .. . .... . ..... 7-7 References for Section 7.4
............................................ 7-9 References for Section 7.5
. .. ....... .. . ..... ... .. ... ..... . .. ... . .. .. . 7-12 References for Section 7.6
. . . . . . .. . . . .... . ......... . . .. . . ...... .... .. 7-16 References for Section 7.7
. .. .. .. . . . . . .... . .... .. . .. ..... . .. . .. . ... . . 7-21 References for Section 7.8
............. . ............................. 7-25 References for Section 8.1
... . . . .. .. . . .. .. . ..... .. .... . ... . . . .. . . .. ... 8-2 References for Section 8.2
............. . .............................. 8-4 References for Section 8.3
............................................ 8-8 References for Section 8.4
. . .............................. . . . ........ 8-19 References for Section 9.1
.. . . .. . ... . ... ............ . ...... . ... . . .... . 9-2 References for Section 9.2
............. . .. . ............. . . .. ...... . .. 9-11 References for Section 9.3
............. . ... . ......................... 9-15 References for Section 9.4
........................................... 9-20 References for Section 9.5
........................................... 9-28 References for Section 9.6
........................................... 9-32 References for Section 10.1
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 10-2 References for Section 10.2
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 10-7

Vlll April 1993LIST OFREFERENCES (Continued) Subject Page 

### References for Section 10.3
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-14 References for Section lOA
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 10-16 References for Section 10.6
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 10-20 References for Section 10.7
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 10-23 References for Section 11.2
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 11-4 References for Section 11.3
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 11-7 References for Section 11.4
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 11-11 Referencesfor Section 11.6
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 11-15 References for Section 12.1
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 12-3 References for Section 12.2
......... : . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 12-9 References for Section 12.3
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 12-11

IX 

### April 1993

### LIST OFTABLES Number Page

5-1 Manual and Automated Methods Approved as ofFebruary 14, 1992
.......... 5-8 9-1 CurrentPSD Increments for PM-lOMeasured as TSP
................... 9-14 12-1 NSPS ParticulateMarter Source Categories
.......................... 12-2



### x April 1993

### 1.0 INTRODUCTION

1.1 OVERVIEW This PM-lO (particles with an aerodynamic diameter less than or equal to a nominal 10 micrometers) guideline represents a compilation ofcurrently available policy and guidance for PM-lO programs and does notpresent any new policy or guidance. The guideline is organized into 12 chapters as follows: Chapter 1 Chapter 2 Chapter 3 Chapter4 Chapter 5 Chapter 6 Chapter7 Chapter 8 Chapter 9 Chapter 10 Chapter 11 Chapter 12 Introduction State Implementation Plans Determining Air 

### Quality Status Emission Inventories Ambient Air 

### Quality Monitoring and Data Usage Air 

### Quality Modeling Stack Height Regulations Control Strategies General Provisions PermitRequirements Compliance and Enforcement New Source Performance Standards Each chapter summarizesrelevantpolicy and guidance and provides detailed references to guide the user to more complete sources. References include statutory and regulatory sources [Clean Air Act and Code ofFederal Regulations (CFR)], Federal ReE!ister notices, U.S. Environmental Protection Agency (EPA) guideline documents, EPA policy, questions and answers (Q & 

### A's), and guidance memoranda. Where appropriate, quotations are provided from the applicable reference materials to be used as a quick reference. Citations to the CFR should be checked regularly as itis updated annually, and the updated versions may not always be reflected in this document This guideline is intended to provide a guide to policy and guidance in effect at the time ofits preparation. 

### ThePM-IO 

### guideline should not be cited in regulatory actions because any regulatory decisions should be based on the original sources, rather than
1-1 April 1993the summaries in each chapter. In 

### addition, in some instances, it is possible that only part ofa document still represents current EPA policy or guidance. Therefore, before citing a document section notexcerpted from the PM-lO policy and guidance in

### the references at the end ofeach chapter, please consultEPA to assure the infonnation is still current It

### is particularly importantto consultwith EPA because significant changes were made to the Clean Air Act (Act) in

### the 1990 Amendments. Section 193 ofthe Actprovides that regulations and guidance issued by EPA prior to the 1990 Amendments remain in effect, exceptto the extent inconsistent with the Act orrevised by EPA. EPA has notundertaken a systematic review ofall ofits previously-issued regulations and guidance to assess its consistency with the revised Act. However, EPA has issued significant guidance since the 1990 revisions to the Act. Thus, the key source to focus on in determining the State implementationplan (SIP) requirements applicable to PM-10 nonattainment areas is, ofcourse, the statute itself. Part 0, 

### Title I ofthe Actcontains the statutory requirements applicable to PM-IO nonattainment areas. Further, importantrecently-issued guidance includes the General Preamble 

### cited in section 1.3 below. Finally, the underlying guidance and memoranda summarized in 

### this document describe EPA's non-binding interpretations ofcertain SIP and SIP-relatedrequirements. Therefore, for example, these interpretations will be given binding effect for a SIP submitted for a particular area only after final EPA rulemaking action on the submittal. During the course ofthis rulemaking action the public will be afforded an opportunity to comment on the application ofany guidance or memoranda to the particular area in question. Thus, EPA will consider the factual circumstances associated with a particular submittal and the submissions made by any persons before giving the preliminary interpretations expressed in guidance and memoranda binding legal effect. Further, use ofwords like "must", "shall" and "required" in this document or the underlying documents should not be treated as having binding legal effect unless the words are employed to describe or recite an already-adopted statutory or regulatory requirement. Except where noted, Appendix A to this guideline contains copies ofall the memoranda, Federal Register notices, and 

### Q& 

### A's cited in the reference sections arranged in chronological order (lengthier documents, such as guidance documents, guidelines, manuals,
1-2 

### April 1993 I•

### etc., are notincluded inAppendix A, but can be obtained from EPA orelsewhere). Appendix B contains a compendium ofsources ofinformation on PM-lO policy and guidance. It consists ofa list ofPM-IO policy and guidance and a table indicating what subjects the policy and guidance covers. The listincludes items that are not specificallyreferenced in the chapters ofthis guideline. These materials are intended to supplementthe materials referenced in this guideline with additional information as needed. The table indicates which policy and guidance items are referenced in this document and which are not.



### 1.2 PROVISIONS FORUPDATING THE GUIDELINE The guideline will be updatedperiodically by adding newpages orreplacing existing pages. Revised pages will be dated and copies will beprovided by the EPA's Office ofAir Quality Planning and Standards (OAQPS) to the EPA Regional Office PM-lO contacts. Citations ofthe CPR are to the most current version at the time ofpreparation ofthis guideline. Users ofthe guideline should refer to later versions ofthe CPR since itis updated on aregular basis. The CFR is published annually including changes for that year. However, newIrevised regulations can be promulgated at any time and States should be aware ofthose prior to publication in the bound CPR. 

### 1.3 ADDITIONAL INFORMATION SOURCES This guideline is intended to be used in conjunction with other guidance documents and policy statements including the following:

• General Preamble (see 57 PR 13598, April 16, 1992 and 57 FR 18070, April 29, 1992).
• Air Programs Policy and Guidance Notebook. Contains many references cited in this guideline which are cross referenced by PN number from the notebook.
• New Source Review Workshop Manual. Contains comprehensive New Source Review guidance.
• New Source Review (NSR)/Prevention ofSignificantDeterioration (PSD) Notebook: contains comprehensive NSR/PSD guidance.

1-3 April 1993

### • Clean Air

### Act Compliance/EnforcementPolicy Compendium: contains comprehensive compliance guidance.
• Guideline for Review ofState implementation plan (SIP) Revisions by EPA Regional Offices: contains references on SIPprocessing.
• Processing procedures for SIP revisions for Part 52, Part 62-ill(d) Plans, and Part 82 Redesignations.
• Guideline on Air 

### Quality Models: contains comprehensive modeling guidance. Where existing guidance is insufficient, State and local agencies should seek clarification from their Regional Office contact. Regional Offices are encouraged to solicit additional guidance when needed from EPA Headquarters personnel. Contactthe SOiParticulate Matter Programs Branch, AQMD, OAQPS at 919/541-5628.

1-4 April 1993

### 2.0 STATE IMPLEMENTATION PLANS

2.1 GENERAL Section 101(b)(1) ofthe Act as amended in 1990 notes that one ofthe purposes ofthe Actis "to protect and enhance the quality ofthe Nation's airresources so as to promote the public health and welfare and the productive capacity ofits popUlation." To this end, the amended Actestablished provisions for setting national ambient air quality standards (NAAQS) for certain airpollutants, including PM-lO. NAAQS for PM-lO were promulgated in 1987. The amended Act establishes the system ofState implementation plans as the method for ensuring that NAAQS are met (section 110). Specifically, the amended Act states that, after promulgation ofNAAQS, each State must adopt and submit to EPA aplan which provides for implementation, maintenance, and enforcement ofthe NAAQS. According to section 107(d)(1) and (4), areas are to be designated as attainment, nonattainrnent, or unclassifiable with respect to the NAAQS. When any area's designation changes to nonattainment, the State mustprepare a revision to the SIP pursuant to section 172 showing how the area will be brought into attainment. Prior to 1990, PM-lO areas were classified in terms ofthe probability ofviolating the NAAQS. As such, PM-lO areas were divided into three groupings identified as Group I, Group 

### IT or Group 

### III areas. 1 Group 

### I areas were areas where the probability ofviolation of the PM-lO NAAQS was 95 percent or greater. Group 

### IT areas were areas where the probability ofviolation was between 20 and 95 percent. In Group III areas, the probability of violation was less than 20 percent. The GeneralPreamble for the Implementation ofTitle I ofthe amended Act states that "on the date ofenactment ofthe 1990 Act, PM-lO areas meeting the qualifications of section 107(d)(4)(B) ofthe amended act were designated nonattainment by operation oflaw. These areas included all former Group I areas identified in 52 FR 29383 and clarified in 55 FR45799 and any other areas violating the PM-lO NAAQS prior to January 1, 1989. All other areas were designated unclassifiable."2 The General Preamble also states that "once an
2-1 April 1993

### areais designated nonattainment, section 188 ofthe amended Act outlines the process for classification ofthe area and establishes the area's attainment date.,,3 

### A detailed discussion of area designation and classification and attainment dates is presented in Section 9.2 ofthis guideline.

2-2 April 1993

### REFERENCES FOR SECTION 2.1



### 1. 52 Federal Register 29,383-85 (August7, 1987), PM-lO Group I and Group IT Areas; List ofPM-lO Group I and Group IT Areas. 2. 57 FederalRegister 13,537 (April 16, 1992), General Preamblefor the Implementation ofTitle I 

### ofthe Clean 

### Air Act Amendments of 1990; Proposed Rule; SIP Requirements; Particulate Matter; Statutory Background; Designations. 3. 57 Federal Register 13,537 (April 16, 1992), General Preamble for the Implementation ofTitle I 

### ofthe Clean 

### Air Act Amendments of 1990; Proposed Rule; SIP Requirements; Particulate Matter; Statutory Background; Classifications and Attainment Dates.

2-3 April 1993

### 2.2 GENERAL SIP APPROACH
The general steps for developing a SIP orrevising a SIP for a PanD nonattainment area are outlined below.
1. Determine the existing PM-lO concentrations in the ambient air to establish the initial (baseline) air qUality. Baseline air quality is determined by using measured air quality data. These baseline air quality data determine the attainment status for an area with regard to PM-lO. 2. Determine whether an area is meeting the NAAQS. The 24-hourNAAQS for PM-lO is 150 pg/m3 , 24-hour average concentration. The 24-hourNAAQS is considered violated when the expected number ofdays percalendar year having a 24-hour average concentration above 150 pg/m3 is greater than one. The annual NAAQS for PM-lO is 50 pg/m3 , arithmetic mean. The annual PM-lO NAAQS isviolated when the expected annual arithmetic mean concentration is greater than 50 pg/m3.1 Ifan area is in violation ofthe NAAQS, EPA will designate the area as nonattainment. The State will then berequired to submit a SIP addressing how the nonattainment area will be brought into compliance with the NAAQS. The amount of time which the State is given to submit the SIP is dependent on whether an area is classified as moderate or serious. 3. Prepare emissions inventories. Emission inventories are needed to determine which industrial sectors or area sources will cause an area to achieve or exceed the ambient standards in future years. The baseline inventory estimates current emissions. A baseline projection estimates future emissions given current controls by taking into account expected emissions growth. Control strategy projections estimate future emissions considering modified or additional controlregulations which affect baseline projections. Development ofemissions inventories is addressed in Section4 ofthis guideline. 4. Evaluate ambient air quality. Developing an implementation plan requires a suitable method for relating pollutant emissions to ambient air quality. The most commonly used method is atmospherIc dispersion modeling. When dispersion models are applied to projected emissions, projected air quality can be determined and used to demonstrate attainment ofthe standard by the attainment deadline. 5. Develop control strategies that ensure attainment and maintenance ofthe NAAQS. Specific control strategies needed to attain the NAAQS are based on projected controlled emissions and the associated ambient air qUality. Control strategies are addressed in Section 8 ofthis document.

2-4 April 1993 Ii I

### 6. Documentthe plan for attainment in 

### the SIP. Requirements for content ofthe SIP are addressed in Section 2.3 ofthis document 7
. Perform post-SIP air 

### quality monitoring to track air quality maintenance and progress toward attainment.

2-5 April 1993

### REFERENCES FOR SECTION 2.2
1. U.S. Environmental Protection Agency. 

### Code of FederalRegulations. Title 40, Cha.pter L Subchapter C, Pan50.6. July 1, 1991.

2-6 April 1993

### 2.3 STATUTORY REQUIREMENTS FORPM·tO 

### SIP's Subsections (A) through (M) ofsection llO(a)(2) ofthe amended Act setforth the elements that a SIP mustcontain 

### inorder to be fully approved.l Under section llO(a)(2), SIP's mustinclude,among other things, the following:

• Enforceable emissions limitations
• Ambient air quality monitoring
• Provisions for enforcement ofcontrol measures and emissions limitations
• Provisions to prohibit sources from significantly affecting NAAQs attainment or maintenance, or conformance with PSD or visibilityrules 

### in a neighboring State
• Assurance ofadequate personnel, funding and authority to carry out the SIP
• Requirements for emissions monitoring and reporting
• Provisions for emergency powers and contingency plans
• Provisions for plan revisions, as necessary
• Provisions for SIP revisions to meet applicable nonattainment area requirements
• Provisions for necessary air quality modeling
• Provisions to collect permit fees required under the Act from major stationary sources adequate to recover the costs ofreviewing and acting upon permit applications and administering the provisions ofthe permit
• Provisions for participation oflocal political subdivisions affected by the plan PM-IO nonattainment area SIP's must meet the following section 172(c) requirements applicable to nonattainment area SIP's generally:

• Implementation ofall reasonably available control measures (RACM) (including reductions in emissions from existing sources in the area obtainable by adopting, at a minimum, reasonably available control technology) and attainmentofthe NAAQS
. • Demonstration ofreasonable further progress (RFP) toward attaining the NAAQS by the applicable date
2-7 April 1993• A comprehensive, accurate, and currentinventory ofactual emissions from all sources oftherelevantpollutant
• Identification and quantification ofPM-lO emissions from the construction or operation ofmajor new ormodified stationary sources. The SIP must demonstrate that these emissions will be consistent with the achievement ofRFP and 

### will notinterfere with attainment ofthe NAAQS
• Require permits for the construction and operation ofmajornew ormodified stationary sources in the nonattainment area
• Provisionsfor appropriate measures to ensure attainmentby applicable date, including enforceable emission limits and other necessary control measures, as well as schedules for compliance
• Compliance with applicable provisions of section 11O(a)(2)
• Provisions for the implementation of specific contingency measures to be taken ifthe nonattainment area fails to make RFP or to meetthe NAAQS by the applicable date PM-lO nonattainment area SIP's must meetthe following PartD, Subpart4 PM-lO specific requirements:

• Provisions for implementation ofRACM for moderate areas according to a specific schedule.
• Provisions for implementation ofbest available control measures (BACM) for serious areas according to a.specific schedule.
• An attainment demonstration (including air**q~ality** modeling).
• Establishment ofa permitprogramproviding that permits meeting the requirements of section 173 are required for the construction and operation ofmajor new or modified PM-lO stationary sources.
• The attainment demonstration planrevision must include quantitative milestones to be achieved every 3 years until the area is redesignated attainment and which demonstrate RFP toward attainment by the applicable date.

2-8 April 1993

### REFERENCES FOR SECTION2.3

1. 57 FederalRegister 13,556 (April 16, 1992), General Preamblefor the Implementation ofTItleI ofthe Clean 

### AirActAmendments of 1990; Proposed Rule; SIP Requirements; General; PartD, Subpart l/Section 1l0{to the ExtentNot Covered UnderPollutant-Specific).

2-9 April 1993

### 3.0 DETERMINING AIR QUALITY STATUS

3.1 SECTION 107 DESIGNATIONS 3.1.1 General According to the General Preamble for the Implementation ofTitle I ofthe Clean Air 

### Act Amendments of 1990, on the date ofenactment ofthe amended Act (November 15, 1990), PM-1O areas meeting the qualifications ofsection 107(d)(4)(B) were designated nonattainmentby operation oflaw.l 

### These areas included all former Group I areas and any other areas violating the PM-1O NAAQS priorto January 1, 1989. All other areas were designated unclassifiable. A Federal Register notice announcing all 

### ofthe areas designated nonattainment for PM-1O at enactment ofthe amended Act and classified as moderate was published in 56 FR 11101 

### (March 15, 1991) and corrected in 56 FR 

### 37654 (August 8, 1991).1 Section 188 ofthe amended Act outlines the process for classification of nonattainment areas and establishes area-specific attainment dates.2 

### At the time of designation, and in accordance with section 188(a), all PM-1O nonattainment areas are initially classified as moderate. In accordance with section 188(b), a moderate area can be reclassified as serious prior to the passage ofthe applicable attainment date if

### EPA determines the area cannot "practicably" attain the PM-lO NAAQS by that date. For the initial moderate PM-1O nonattainment areas, the amended Act specifies certain dates by which EPA must propose to reclassify appropriate moderate areas as serious and take final action. In 

### addition, a moderate area can be reclassified as serious subsequent to the passage ofthe applicable attainment date if

### EPA determines the area has failed to attain by that date?



### 3.1.2 Designating Areas as Nonattainment The amended Act, in accordance with section 107(d)(3), authori::?es EPA to promulgate the designation ofnew areas as nonattainment for PM-lO on the basis ofair quality data, planning and control considerations, or any other air 

### quality-related consideration that the Administrator deems appropriate.3 

### As part ofthe designation process, EPA notifies the governors ofthose States with areas that EPA believes should be redesignated as
3-1 April 1993

### nonattainment Governors ofaffected States mustthen submitto EPA the designation they consider appropriate for each area in question within 120 days. No laterthan 120 days after a Governor's response, if

### any, EPA mustpromulgate those redesignations which EPA deems necessary and appropriate.3 

### On April 22, 1991 EPA announced in 56 FR 16274thatithad initiated the redesignation process for 16 areas. Pursuant to section 189(a)(2)(B) ofthe amended Act, States must submit PM-lO SIP'sfor these areas to EPA within 18 months after EPA promulgates the nonattainment designation.3 

### 3.1.3 Area Boundaries Section 107 nonattainment areas for PM-lO must have clearly identifiablepolitical or physical boundaries and are generally described by EPA as acity, county, ortownship.4 Generally, when EPA lists municipal boundaries or other boundaries identifying aperimeter, all ofthe area within those boundariesispart ofthe nonattainment area unless otherwise specified. In the process ofmonitoring and modeling PM-I0 concentrations and determining the extent ofsources ofPM-lO emissions that impact the areas, the States will

### better identify the boundaries ofthe area thatis or may be violating the standards.5 

### Guidance was provided in the PM-10 SIP Development Guideline 

### on how to further define the extent ofareas violating the PM-lO standards in the process ofdeve19ping PM-lO SIP's. On October 31, 1990, EPA clarified the description ofcertain Group I and Group IT areas ofconcern listed in the original August 7, 1987 notice.6 

### Further corrections for the initial moderate areas were published on August 8, 1991 in response to comments from States.7



### 3.1.4 Redesignating Areas to Attainment The following is an expanded discussion ofthe criteria which must be met before an area can be redesignated from nonattainment to attainment. It is suggested that the reader refer to the memorandum dated September4, 1992 from John Calcagni to the Regional Air Division Directors entitled Proceduresfor Processing Requests to RedesignateAreas to Attainment

### for an extended discussion ofthese criteria.s



### 3-2 April 1993• Attainment ofthe NAAQS: The State must show that the area is attaining the PM-lO NAAQS. There are two components involvedin making this demonstration which should be considered interdependently. The first component relies on air quality data. The showing of attainment for PM-lO through air quality data mustrely on 3 complete, consecutive calendar years ofquality-assured air quality monitoring data, collectedin accordance with 40 CFR 50, Appendix K.9 According to 40 CPR 50.6, the area may be considered as attaining the primary and secondary 24-hourNAAQS (150 Jlg/m3) when the expected number ofexceedances per year ateach monitoring site is less than or equal to one. In the simplest case, the expected numberofexceedances is determined by recording the number ofexceedances in each calendar year, and then averaging over the past 3 years. The annual primary and secondary PM-lO NAAQS are attained when the expected annual arithmetic mean PM-lO concentration is less than orequal to the level ofthe standard (50 Jlg/m3). In the simplest case, the expected annual arithmetic mean is determined by averaging the annual means for the past 3 calendar years. Situations in which 3 years ofdata are not available and possible adjustments for unusual events ortrends are necessary are discussed in Sections 2.3 and 2.4 of40 CFR 50, Appendix K.ID
The second componentrelies on supplemental airquality modeling. Modeling may be necessary to determine the representativeness ofthe monitored data. For PM-lO, dispersion modeling will generally be necessary to evaluate comprehensively a source's impacts and to determine the areas ofexpected high concentrations based upon current conditions. Regions should consult with OAQPS for further guidance addressing the need for modeling in specific circumstances.I I Approved 110(k) SIP for the area The SIP for the area must be fully approved under section llO(k) ofthe Act and must satisfy all requirements that apply to the area. "An area cannot be redesignated ifa required element ofits plan is the subject ofa disapproval; a finding offailure to submit or to implement the SIP; orpartial, conditional, or limited approval. However, this does not mean that earlier issues with regard to the SIP will be reopened."12

3-3 April 1993• Permanent and enforceable improvement in air quality The State must be able to reasonably attribute the improvementin air quality to emission reductions which are pennanentand enforceable. 

### In making this showing, the State should estimate the percentreduction achieved from Federal measures. 13

• Section 

### 110 and PartD Requirements A State must meet all requirements ofsection llO and Title I, PartD ofthe Act that were applicable prior to submittal ofthe complete redesignationrequest. Section 110(a)(2) contains generalrequirements for nonattainment SIP's. Part D consists of general requirements applicable to all areas designated nonattainment and specific requirements applicable to certain NAAQS including PM_1O.14

• Fully approved maintenanceplan

plan: Before an area can be redesignated to attainment, EPA must approve a maintenance plan which meets the requirements ofsection l75A.IS The maintenanceplan will constitute a SIPrevision and mustprovide for maintenance ofthe PM-lO NAAQS in the area for at least 10 years after redesignation. 16 

### In addition, the maintenance plan shall contain such contingency measures necessary to ensure prompt correction ofany violation ofthe PM-I0 NAAQS. At a minimum, these measures mustinclude a requirement that the State will implement all measures contained in the nonattainment SIP priorto redesignationP

The following is a list ofthe provisions that should be included in a maintenance

Attainmentinventory: The State should develop an attainment emissions inventory to identify the level ofemissions in the area which is sufficient to attain the PM-lO NAAQS.18
Maintenance demonstration: A State may generally demonstrate maintenance ofthe NAAQS by either showing that future emissions ofPM-lO will not exceed the level ofthe attainment inventory, or by modeling to show that the future mix of sources
3-4 April 1993and emission rates will not cause a violation ofthe PM-lO NAAQS.19 Ineither case, the State should project emissions for the lO-year period following redesignation.20 

### Monitoring network: Once an area has beenredesignated, the State should continue to operate an appropriate air quality monitoring network to verify the attainment status ofthe area.21 

### Verification ofcontinuedattainment: Each State should ensure that ithas the legal authority to implement and enforce all measures necessary to attain and to maintain the PM-lO NAAQS. The State submittal should indicate how the State will track the progress ofthe maintenance plan.22 

### Contingencyplan: The maintenance plan must contain contingencyprovisions that will promptly correct any violation ofthe PM-lO NAAQS that occurs after redesignation. For the purposes ofsection 175A, a State is notrequired to have fully adopted contingency measures that will take effect without further action by the State in orderfor the maintenance plan to be approved. However, the contingencyplan is considered to be an enforceablepart ofthe SIP and should ensure that contingency measures are adopted expediently once they are triggered. Theplan should clearly identify the measures to be adopted, a schedule and procedure for adoption and implementation, and a specific time limitfor action by the State.23 The EPA will review what constitutes
.a contingencyplan on a case-by-case basis. Ata minimum, itmust require that the State will implement all measures contained 

### in the PartD nonattainmentplan for the area prior to redesignation. This language suggests that a State may submit a SIP revision at the time ofits redesignation request to remove or reduce the stringency ofcontrol measures. The EPA can approve such arevision 

### if itprovides for compensating equivalentreductions. Alternatively, a State might be able to demonstrate that the measures are not necessary for maintenance ofits standard.24

3-5 April 1993

### REFERENCES FOR SECTION3.1

1. 57 Federal Register 13,537 (April 16, 1992), General Preamble for the Implementation ofTItle I ofthe Clean Air Act Amendments of 1990; Proposed Rule; SIP Requirements; Particulate Matter; Statutory Background; Designations. 2
. 57 Federal Register 13,537 (April 16, 1992), General Preamblefor the Implementation ofTItle I ofthe Clean 

### Air Act Amendments of 1990; Proposed Rule; SIP Requirements; Particulate Matter; Statutory Background; Classifications and Attainment Dates. 3. 56 Federal Register 16,274-77 (April 22, 1991), Preparation, Adoption, and Submittal ofState Implementation Plans; PM-lO, Sulfur Dioxide, and Lead Nonattainment and Unclassifiable Area Designations; Background for PM-I0. 4. "Using the above criteria, boundaries offuture nonattainment areas should be specified using clearly identifiable political or physical boundaries. This could include city, county, or State boundaries orrivers and mountain ranges. However, the boundaries should encompass the entire area to which a control strategy is expected to 3.pply. The default area for PM-lO designations are the county boundaries." Memorandum from Seitz, John S., Director, OAQPS, to Addressees
. Nonattainment Designations and Classifications. November 14, 1990. 5. 52 Federal Register 29,383-85 (August 7, 1987), PM-lO Group I and Group IIAreas. 

### 6. 55 Federal Register 45,799-803 (October 31, 1990), Preparation, Adoption, and Submittal ofState Implementation Plans; Corrections to PM-lO Areas ofConcern. 7. 56 Federal Register 37,654-65 (August 8, 1991), Designations and Classifications for Initial PM-lO NonattainmentAreas. 

### 8
. Memorandum from Calcagni, John, Director, 

### Air Quality ManagementDivision, OAQPS, U.S. EPA, Research Triangle Park, NC, to Director, Air, Pesticides and Toxics ManagementDivision, Regions 

### I and IV; Director, 

### Air and Waste Management Division, Region II; Director, Air, Radiation and Toxics Division, Region 

### ill; Director, Air and Radiation Division, Region V; Director, 

### Air, Pesticides, and Toxics Division, Region VI; and Director, Air and Toxics Division, Regions 

## vn, VIII, IX, and X. Procedures for Processing Requests to Redesignate Areas to Attainment. September 4, 1992. 9. "The State must show that the area is attaining the applicable NAAQS
. There are two components involved in making this demonstration which should be considered interdependently. The first component relies upon ambient air quality data. The data that are used to demonstrate attainment should be the product ofambient monitoring 3-6 April 1993thatis representative ofthe area ofhighest concentration. These monitors should remain at the same location for the duration ofthe monitoring periodrequired for demonstrating attainment
... For PM-I0, the areamay be considered attaining the NAAQS 

### ifthe number ofexpected exceedancesperyear, according to 40 CFR 50.6, 

### is less than orequalto 1.0. Inmaking this showing, both PM-lO and 0 3 mustrely on 3 complete, consecutive calendaryears ofquality-assured air quality monitoring data, collectedin accordance with 40 CFR 50, Appendices Hand K. II Memorandum from Calcagni, John, Director, Air Quality ManagementDivision, OAQPS, U.S. EPA, Research Triangle Park, NC, to: Director, Air, Pesticides and Toxics Management Division, Regions I and IV; Director, Air and Waste ManagementDivision, Region IT; Director, Air, Radiation and Toxics Division, Region 

### ill; Director, Air and Radiation Division, Region V; Director, Air, Pesticides, and Toxics Division, Region VI; and Director, 

### All- and Toxics Division, Regions VIT, VITI, IX, and X. Procedures for Processing Requests to Redesignate Areas to Attainment. September 4, 1992. 10. U.S. Environmental Protection Agency, Code ofFederal Regulations, Title 40, Chapter I, Subchapter C, Part 50, Appendix K. July 1, 1991. 11. "The second componentrelies on supplemental EPA-approved air qUality modeling
..

. Modeling may be necessary to detennine the representativeness ofthe monitored data
... When dealing with S02' Pb, PM-lO (exceptfor a limited number ofinitial moderate nonattainment areas),
...dispersion modeling will generally be necessary to evaluate comprehensively sources' impacts and to deterniine the areas ofexpected high concentrations based upon current conditions. Areas which were designated nonattainment based on modeling will generally not be redesignated to attainment unless an acceptable modeling analysis indicates attainment. Regions should consult with OAQPS for further guidance addressing the need for modeling in specific circumstances. II Memorandum from Calcagni, John, Director, Air Quality ManagementDivision, OAQPS, U.S. EPA, Research Triangle Park, NC, to: Director, Air, Pesticides and Toxics Management Division, Regions I and IV; Director, Air and Waste Management Division, Region II; Director, Air, Radiation and Toxics Division, Region III; Director, Air and Radiation Division, Region V; Director, Air, Pesticides, and Toxics Division, Region VI; and Director, Air and Toxics Division, Regions VII, VIII, IX, and X. Procedures for Processing Requests to Redesignate Areas to Attainment. September4, 1992. 12. "The SIP for the area must be fully approved under section 11O(k), and must satisfy all requirements that apply to the area. Itshould be noted that approval action on SIP elements and the redesignation request may occur simultaneously. An area cannot be redesignated 

### ifarequired element ofitsplan is the subject ofa disapproval; a finding offailure to submit or to implement the SIP; orpartial, conditional, orlimited approval. However, this does not mean that earlierissues with regard to the SIP will be reopened. Regions should notreconsider those things that have already been approved and for which the Clean Air Act Amendments did notalter what is required. In contrast, to the extent the amendments add a requirement or alter an existing requirement so that it adds something more, Regions should consider those issues. In 3-7 April 1993addition, requests from areas known to be affected by dispersion techniques which are inconsistent with EPA guidance will continue to be considered unapprovable under section 110 and will not qualify forredesignation." Memorandum from Calcagni, John, Director, AirQuality ManagementDivision, OAQPS, U.S. EPA, Research Triangle Park, NC, to: Director, Air, Pesticides and Toxics ManagementDivision, Regions I and IV; Director, Air andWaste ManagementDivision, Region II; Director, Air, Radiation andToxics Division, Region III; Director, Air and Radiation Division, Region V; Director, Air, Pesticides, and Toxics Division, Region VI; andDirector, Air andToxics Division, Regions VII, VIII, IX, and X. Procedures for Processing Requests to Redesignate Areas to Attainment. September4, 1992. 13. "The State must be able to reasonably attribute the improvement in air quality to emission reductions which are permanent and enforceable. Attainmentresulting from temporary reductions in emission rates (e.g., reducedproduction or shutdown due to temporary adverse economic conditions) or unusually favorable meteorology would not qualify as an air quality improvement due to permanent and enforceable emission reductions. In making this showing, the State would estimate the percentreduction (from the year that was used to determine the design value for designation and classification) achieved from Federal measures..." Memorandum from Calcagni, John, Director, Air Quality ManagementDivision, OAQPS, U.S. EPA, Research Triangle Park, NC, to: Director, Air, Pesticides and Toxics ManagementDivision, Regions I and IV; Director, Air and Waste ManagementDivision, Region II; Director, Air, Radiation andToxics Division, Region III; Director, Air and Radiation Division, Region V; Director, Air, Pesticides, and Toxics Division, Region VI; andDirector, Air and Toxics Division, Regions VII, VIII, IX, and X. Procedures for Processing Requests to Redesignate Areas to Attainment. September4, 1992. 14. "For the purposes ofredesignation, a State must meet all requirements of section 110 and Part D ofthe Act that were applicable prior to submittal ofthe complete redesignation request. When evaluating a redesignation request, Regions should not consider whether the State has met requirements that come due under the Act after submittal ofa complete redesignation request. However, any requirements that came due prior to submittal ofthe redesignation request must be fully approved into the plan at or before the time EPA redesignates the area. Section llO(a)(2) contains general requirements for nonattainment plans. Most ofthe provisions ofthis section are the same as those contained in the pre-amended Act.
.. Part D consists ofgeneral requirements applicable to all areas which are designated nonattainment based on a violation ofthe NAAQS. The general requirements are followed by a series of subparts specific to each pollutant. The general requirements appear in subpart 1. The requirements relating to 03' CO, PM-IO, S02' N02, and Pb appear in subparts 2 through 5. In those instances where an area is subject to both the general nonattainment provisions in subpart 1 as well as one ofthe pollutant-specific subparts, the general provisions may be subsumed within, or superseded by, the more specific requirements of subparts 2 through 5." Memorandum from Calcagni, John, Director, Air Quality ManagementDivision, OAQPS, U.S. EPA, Research Triangle Park, NC, to: Director, Air, Pesticides and Toxics ManagementDivision, Regions I and IV; 3-8 April 1993Director, Air andWaste Management Division, Region II; Director, Air, Radiation and Toxics Division, Region

### ill; Director, Air and Radiation Division, Region 

### V; Director, Air, Pesticides, and Toxics Division, Region VI; and Director, Air and Toxics Division, Regions

## vn,vm, IX, and X
. Procedures for Processing Requests to**Red~signate** Areas to Attainment. September4, 1992. 15. "Section 107(d)(3)(E) ofthe amended Act stipulates thatfor an area to be redesignated, EPA must fully approve a maintenance plan which meets the requirements ofsection 175A. A State may submitboth theredesignation request and the maintenance plan atthe same time and rulemaking on both mayproceed on a parallel track. Maintenance plans may, ofcourse, be submitted and approved by EPA before aredesignation isrequested. However, according to section 175A(c), pending approval ofthe maintenance plan and redesignation request, all applicable nonattainment arearequirements shall remain in place." Memorandumfrom Calcagni, John, Director, Air Quality Management Division, OAQPS, U.S. EPA, Research Triangle Park, NC, to: Director, Air, Pesticides and Toxics ManagementDivision, Regions I and IV; Director, Air and Waste ManagementDivision, Region II; Director, Air, Radiation and Toxics Division, Region 

### In; Director, Air and Radiation Division, Region V; Director, Air, Pesticides, and Toxics Division, Region VI; and Director, Air and Toxies Division, Regions VII, VIII, IX, and X. Procedures for Processing Requests to Redesignate Areas to Attainment. September

### 4, 1992. 16. "Section 175A defines the general framework ofa maintenance plan. The maintenance plan will constitute a SIPrevision and must provide for maintenance of the relevant NAAQS in the area for atleast 10 years afterredesignation. Section 175A further states that the plan shall contain such additional measures, ifany, as may be necessary to ensure such maintenance. Because the Actrequires a demonstration of maintenance for 10 years after an area isredesignated (not 10 years after submittal of a redesignation request), the State should plan for some lead time for EPA action on the request .. Indetermining the amountoflead time to allow, States should considerthat section 107(d)(3)(D) grants the Administrator up to 18 months from receipt ofa complete submittal to process aredesignation request." Memorandum from Calcagni, John, Director, Air Quality Management Division, OAQPS, U.S. EPA, Research Triangle Park, NC, to: Director, 

### Air, Pesticides and Toxics Management Division, Regions 

### I and 

### IV; Director, Air and Waste ManagementDivision, Region 

### n; Director, Air, Radiation and Toxics Division, Region 

### ill; Director, Air and Radiation Division, Region V; Director, 

### Air, Pesticides, and Toxics Division, Region VI; and Director, 

### Air and Toxics Division, Regions VII, VIII, IX, and X
. Procedures for Processing Requests to Redesignate Areas to Attainment. September

### 4, 1992. 17. "In addition, the maintenanceplan shall contain such contingency measures as the Administrator deems necessary to ensureprompt correction ofany violation ofthe NAAQS [see section 175A(d)]. The Actprovides that, at a minimum, the contingency measures must include arequirement that the State 

### will implement all measures contained in the nonattainment SIPprior to redesignation. Failure to maintain the NAAQS and triggering ofthe contingencyplan will not necessitate a revision ofthe 3-9 April 1993SIP unless required by the Administrator, as stated in section 175A(d)." Memorandum from Calcagni, John, Director, 

### Air Quality ManagementDivision, OAQPS, U.S
. EPA, Research Triangle Park, NC, to: Director, 

### Air, Pesticides andToxics Management Division, Regions I and 

### N; Director, 

### Air and Waste ManagementDivision, Region II; Director, 

### Air, Radiation and Toxics Division, Region 

### ill; Director, 

### Air and Radiation Division, Region 

### V; Director, 

### Air, Pesticides, and Toxics Division, Region 

### VI; and Director, 

### Air and Toxics Division; Regions 

### VIT, VIII, IX, and

### X. Procedures for Processing Requests to Redesignate Areas to Attainment September

### 4, 1992. 18. "The State should develop an attainment emissions inventory to identify the level of emissions in the area which is sufficientto attain the NAAQS. This inventory should be consistent with EPA's mostrecent guidance on emission inventories for nonattainment areas available at the time and should include the emissions during the time period associated with the monitoring data showing attainment Source size thresholds are 100 tons/year for 

### SOz, NOz , andPM-lO areas, and 5 tons/year for Pb based upon 40 CFR 5l.100(k) and 51.322, as well as established practice for AIRS data. The source size threshold for serious PM-lO areas is70 tons/year according to Clean 

### Air Act section 189(b)(3)." Memorandum from Calcagni, John, Director, Air Quality Management Division, OAQPS, U.S. EPA, Research Triangle Park, NC, to:

19. Director, Air, Pesticides and Toxics Management Division, Regions I and

### N; Director, Air and Waste Management Division, Region IT; Director, Air, Radiation and Toxies
. Division, Region 

### ill; Director, 

### Air and Radiation Division, Region 

### V; Director, Air, Pesticides, and Toxics Division, Region 

### VI; and Director, Air and Toxics Division, Regions VII, VllI, 

### IX, and X. Procedures for Processing Requests to Redesignate Areas to Attainment. September4, 1992. "A State may generally demonstrate maintenance ofthe NAAQS by either showing that future emissions ofa pollutant or its precursors will not exceed the level ofthe attainment inventory, orby modeling to show that the future mix ofsources and emission rates will not cause a violation ofthe NAAQS. Under the Clean Air Act, many areas are required to submitmodeled attainment demonstrations to showthat proposedreductions in emissions will 

### be sufficient to attain the applicable NAAQS. Forthese areas, the maintenance demonstration should be based upon the same level ofmodeling. In areas where no such modeling was required, the State should be able to rely on the attainmentinventory approach. 

### In both instances, the demonstration should be for a period of 10 years following the redesignation." Memorandum 

### from Calcagni, John, Director, Air Quality Management Division, OAQPS, U.S. EPA, Research Triangle Park, NC, to: Director, 

### Air, Pesticides and Toxies Management Division, Regions 

### I and 

### N; Director, 

### Air and Waste ManagementDivision, Region 

### II; Director, 

### Air, Radiation and Toxics Division, Region 

### ill; Director, Air and Radiation Division, Region 

### V; Director, 

### Air, Pesticides, and Taxies Division, Region 

### VI; and Director, Air and Toxics Division, Regions VII, VIII,

### IX, and 

### X. Procedures for Processing Requests to Redesignate Areas to Attainment. September 

### 4, 1992. 20
. "In either case, to satisfy the demonstration requirement the State should project emissions for the lO-year period following redesignation, eitherfor the purpose of 3-10 April 1993

### showing that emissions will not increase over the attainment inventory orfor conducting modeling. The projectedinventory should considerfuture growth, including population andindustry, should be consistent with the attainment inventory, and should document data inputs and assumptions. All elements ofthe demonstration (e.g., 

### emissions projections, new source growth, and modeling) should be consistent with currentEPA modeling guidance." Memorandum from Calcagni, John, Director, Air Quality ManagementDivision, OAQPS, U.S
.EPA, Research Triangle Park, NC, to: Director, Air, Pesticides and Toxics Management Division, Regions I and IV; Director, Air andWaste Management Division, Region II; Director, Air, Radiation and Toxics Division, Region III; Director, Air and Radiation Division, Region V; Director, Air, Pesticides, and Toxics Division,Region VI; and Director, Air and Toxics Division, Regions VII,

### vrn, IX, and X. Procedures for Processing Requests to Redesignate Areas to Attainment. September 4, 1992. 21. "Once an area has been redesignated, the State should continue to operate an appropriate air quality monitoring network, in accordance with 40 CFRPan58, to verify the attainment status ofthe area. The maintenance plan should contain provisions for continued operation ofair quality monitors that will provide such verification. In cases where measured mobile source parameters have changed over time (e.g., 

### vehicles miles traveled congestion), the State may also need to perfonn a saturation monitoring study to determine the need for, and location of, additional pennanent monitors." Memorandum from Calcagni, John, Director, Air Quality Management Division, OAQPS, U
.S. EPA, Research Triangle Park, NC, to: Director, Air, Pesticides and Toxics Management Division, Regions I and IV; Director, Air and Waste Management Division, Region II; Director, Air, Radiation and Toxies Division, Region III; Director, Air and Radiation Division,Region V; Director, Air, Pesticides, and Toxics Division, Region VI; and Director, Air and Toxics Division, Regions VII, VIII, IX, and X. Procedures for Processing Requests to Redesignate Areas to Attainment. September4, 1992. 22. "Each State should ensure that it has the legal authority to implement and enforce all measures necessary to attain and to maintain the NAAQS
. Section 1l0(a)(2)(b) and (F) ofthe Clean Air Act, as amended, and regulations promulgated at 40 CFR 51.110(k), suggest that one such measure is the acquisition ofambient and source emission data to demonstrate attainment and maintenance. Regardless ofwhether the maintenance demonstration is based on a showing that future emission inventories will not exceed the attainment inventory or on modeling, the State submittal should indicate how the State will track the progress ofthe maintenance plan. This is necessary due to the fact that the emission projections made for the maintenance demonstration depend on assumptions ofpoint and area source growth." Memorandum from Calcagni, John, Director, Air Quality ManagementDivision, OAQPS, U
.S. EPA, Research Triangle Park, NC, to: Director, Air, Pesticides and Toxics Management Division, Regions I and IV; Director, Air and Waste Management Division, Region II; Director, Air, Radiation and Toxics Division, Region III; Director, Air and Radiation Division, Region V; Director, Air, Pesticides, and Toxics Division, 3-11 

### April 1993Region VI; and Director, Airand Toxics Division, Regions VIT,

# vrn, IX, and X. Procedures for Processing Requests to Redesignate Areas to Attainment. September 4, 1992. 23. "Section 175A ofthe Actalso requires that a maintenance plan include contingency provisions, as necessary, to promptlycorrect any violation ofthe NAAQS that occurs afterredesignation ofthe area. .. Forthe purposes ofsection 175A, a State is not required to have fully adopted contingency measures that

### will take effectwithout further action by the Statein orderfor the maintenanceplan to be approved. However, the contingencyplan is considered to be an enforceablepart ofthe SIP and should ensure thatthe contingency measures are adopted expediently once they are triggered. Theplan should clearly identify the measures to be adopted, a schedule and procedure for adoption and implementation, and a specific time limitfor action by the State. As a necessary part' ofthe plan, the State should also identify specific indicators, ortriggers, which will be used to determine when the contingency measures need to be implemented." Memorandumfrom Calcagni, John, Director, Air Quality Management Division, OAQPS, U.S. EPA, Research Triangle Park, NC, to: Director, Air, Pesticides and Toxics ManagementDivision, Regions I and IV; Director, Air and Waste Management Division, Region II; Director, Air, Radiation and Toxics Division, Region 

### ill; Director, Airand Radiation Division, Region V; Director, Air, Pesticides, and Toxics Division, Region VI; and Director, Air and Toxies Division, Regions VII, VITI, IX, and X. Procedures for Processing Requests to Redesignate Areas to Attainment. September4, 1992. 24. "The EPA will review what constitutes a contingency plan on a case-by-case basis. At a minimum, itmustrequire that the State will implement all measures contained in the Part D nonattainmentplan for the areaprior to redesignation [see section 175A(d)]. This language suggests that a State may submit a SIP revision atthe time ofits redesignation request to remove orreduce the stringency ofcontrol measures. Such a revision can be approved by EPA ifitprovides for compensating equivalent
. reductions. A demonstration that measures are equivalent would have to include appropriate modeling or an adequatejustification. Alternatively, a State might be able to demonstrate (through EPA-approved modeling) that the measures are not necessary for maintenance ofthe standard. In either case, the contingency plan would have to providefor implementation ofany measures that were reduced orremoved after redesignation ofthe area." Memorandumfrom Calcagni, John, Director, Air Quality Management Division, OAQPS, U.S. EPA, Research Triangle Park, NC, to: Director, Air, Pesticides and Toxics Management Division, Regions I and IV; Director, Air and Waste ManagementDivision, Region IT; Director, Air, Radiation and Toxics Division, Region

### ill; Director, Air and Radiation Division, Region V; Director, Air, Pesticides, and Toxics Division, Region VI; and Director, Air and Toxics Division, Regions VIT, VIII, IX, and X. Procedures for Processing Requests to Redesignate Areas to Attainment. September4, 1992.

3-12 April 1993

### 3.2 AMBIENT AIR

3.2.1 General Ambient airis defined in40 

### CPR 50.1(e) as "thatportion ofthe atmosphere, external to buildings, to which the general public has access." Generally, this definition signifies that ambient air would constitute any air to which the public could be exposed, even for a short period oftime. The only exemption from the ambient airprovision is the attnosphere over land that is owned or controlled by the source and to whichpublic access (and, therefore, exposure) isprecluded by a fence or other physical barrier.l It should be noted thatfor sources operating on leased property, ambient air is considered to exclude only the atmosphere over the land leased and controlled by the source?



### 3.2.2 Location Aspects The EPA considers ambient air to include elevated building receptor sites and parking lots to which the public has access. Although itmay notbe practical to analyze the air quality at every such location, States should evaluate the airquality impact at these sites ifit seems necessary to protect health and welfare.3• 4
For modeling purposes, ambient airis considered to be everything outside of contiguousplantproperty where public access is notprecluded by an effective physical barrier. Therefore, modeling receptors should be placed anywhere outside ofinaccessible plantproperty, including over bodies ofwater, unfenced plantproperty, on buildings, over roadways and overproperty owned by ·other sources.5• 6 Thefollowing examples should clarify potential uncertainties regarding receptor location. Inthe case ofwaterways, receptors should be placed over any body ofwater not privately owned and to which public access is allowed. Even where public recreational traffic is limited, the air above a body ofwater should be considered ambient air as long as the potential for public exposure exists.7 With respect to roadways dividing plantproperty, the air above the roadway should be monitored by areceptor, even ifthe road separates otherwise inaccessibleprivate property owned by a single source.8• 9 Regarding property owned by other
3-13 April 1993sources, currentpolicyrequires thatreceptors be placed over neighboring propertyregardless ofpublic accessibility: the atmosphere above neighboring property is considered "ambient air" 

### inrelation to emissions from a given source.to 

### 3.2.3 Time Aspects
Even ifpublic access to a given site is time-limited, the site should not

### be excluded from the ambient air definition as long as the other conditions apply. Regardless ofthe period ofexposure at a given site (orreceptor), ambient air is defined 

### in tenns ofpublic access, notfrequency ofaccess, length ofstay, age ofperson or otherfactors. ll



### 3.2.4 Public Access Ifan area is owned orleased by the source and public access is prevented, the area is not ambient air with respect to the source's own emissions. However, there must be sufficient barriers to preventpublic access. Barriers considered sufficient to prevent access are generally limited to fences. However, a clearlyposted area alongside ariver thatis regularly patrolled by security guards has beendetermined to qualify as sufficient protection.12.13



### 3.2.5 PSD Considerations Unlike the NAAQS, PSD increments apply only to the ground level and not to building rooftops. The PSD system, unlike the NAAQS system, does not attempt to achieve one single goal: instead, itrepresents a balance determined by Congress between economic growth and deterioration ofair quality. Ifbuilding rooftops were included in PSD permitting strategy, the PSD system would be appreciably more stringentthan Congress had contemplated.14 Althoughrooftops are not defined as ambient air when calculating PSD increment consumption, a State may measure PSD increments at the top ofbuildings ifit so desires.15.16

3-14 April 1993

### 3.2.6 

### Land Acquisition Land acquisition and removal ofthe area from ambient air 

### is not automatically considered a dispersion technique prohibitedby section 123, but will 

### instead be

### reviewed on a case-by-case basis. (Also see the discussion on stackheightregulations in Section 7 ofthis report) In 

### only afew instances has the EPA tolerated land acquisition to contain modeled violations ofthe NAAQS.17



### 3.2.7 Monitor Siting Location Considerations With respectto receptor locations for modeling and ambient air purposes, EPA does not consider whether such sites could meet standard siting criteria for monitors. Although siting criteria may preclude the placement ofambient monitors at certain locations, this does notpreclude the placement ofmodel receptors at these sites.18



### 3-15 April 1993

### REFERENCES FOR SECTION 3.2

1. "We are retaining the policy thatthe exemptionfrom ambient air is available only for the atmosphere overland owned or controlled by the source and to which public access is precluded by a fence or otherphysical barriers." Letterfrom Douglas M. Costle to Jennings Randolph, Chairman, Committee on Environment and Public Works, United States Senate, Washington, D.C. Reply to letter ofOctober 23, expressing continued interestin the Agency's definition of "ambient air." December 19, 1980. (pN-123-80-12-19-001). 2. "We agree with yourposition that allproperty outside ofthe property leased and controlled by EFKI would be considered ambient air." Memorandumfrom Helms, G.T., OAQPS, U.S. EPA, to W.S. Baker, 

### Air Branch Chief, Region

### n. Ambient

### Air Issues from New Jersey Department ofEnvironmental Protection. July 27, 1987. 3. "Ourgeneral policyis that the only exemption to compliance with the provisions of ambient air is for the atmosphere over land owned or controlled by the source and to which public access is precluded by a fence or otherphysical barriers. While EPA considers ambient air to include elevated building receptor sites, itis notpractical to analyze the air quality at every such existing location. Therefore, both EPA and the States mustexercise their best technicaljudgment as to when such sites must be evaluated so as to protectpublic health and welfare." Letter from Kathleen M. Bennett, Assistant Administrator for Air, Noise, and Radiation, to Harry H. Hovey, Jr. P.E., Director, Division ofAir, New York State Department ofEnvironmental Conservation, Albany, New York. March 18, 1983. (PN-llO-83-03-18-063). 4. "Having concluded that the air above the parking lot is ambient air, we see no basis for excluding itfrom coverage by the State's implementationplan." Memorandum from James, M.A., OGC, to C. Simon, Chief, 

### Air Programs Branch, U.S. EPA. Region

### n. Attainment ofNational Standards in Open Air Parking Lots. September 27, 1972. 5. "The Regional Meteorologists propose that for modeling purposes the air everywhere outside ofcontiguous plantproperty to which public access is precluded by a fence or other effective physical barrier should be considered 

### in locating receptors. Specifically, for stationary source modeling, receptors should be placed everywhere outsideinaccessibleplantproperty. For example, receptors should be included over bodies ofwater, over unfenced plantproperty, on buildings, overroadways, and over property owned by other sources." Memorandum from Koerber, M., U.S. EPA. Region V, to 

### J. Tikvart, OAQPS, U.S. EPA. Ambient

### Air. May 16, 1985. 6. "The Regional Meteorologists' memorandum to which you refer does not imply any change in this national policy and simply harmonizes modeling procedures with our long-standing policy. It is intended to ensure consistentRegional implementation of 3-16 April 1993

### thatpolicy and to dispel any questions aboutpollutant concentrations at locations where the general public has access." Letter from Emison, G.A., OAQPS, U.S. EPA, to W.P. O'Keefe, AmericanPetroleum Institute. January 22, 1986. 7. "Case 3 (Wayne County. MI): this case involves the**~** 

### over the Detroit River. the Rouge River. and the Short-cut Canal. We agree that the air 

### over all 

### three ofthese is ambient air, 

### since none ofthe companies owns them or controlspublic access to them." Memorandum from G.T. Helms. Chief, ControlPrograms Operations Branch, OAQPS, U.S. EPA, to Steve Rothblatt, Chief, Air

### Branch, U.S. EPA. Region V. Ambient Air. 

### April 30, 1987. (PN-llO-87-04-30-083). 8. "Case 1 (Dakota County, MN): This case involves two noncontiguous pieces of fenced property owned by the same source, divided by apublic road. We agree that the road is clearly ambient air and that both fenced pieces ofplantproperty are not." Memorandum from G.T. Helms, Chief, Control Programs Operations Branch, OAQPS, U.S. EPA, to Steve Rothblatt, Chief, Air 

### Branch, U.S. EPA. Region V. Ambient Air. April 30, 1987. (PN-llO-87-04-30-083). 9. "Scenario One: We agree with you thatthe road and the unfenced property are ambient air 

### and could be locations for controlling receptor." Memorandumfrom G.T. Helms, Chief, Controlled Programs Operations Branch, OAQPS, U.S. EPA, to Bruce Miller, Chief, AirPrograms Branch, U.S. EPA. Region IV. Ambient Air. April 30, 1987. (PN-110-87-04-30-082). 10. "Case 5: (involves the placementofreceptors on another source's fenced property): As mentioned above in 

### case 2, we feel thatpresent policy does require thatreceptors be placed over another source'sproperty to measure the contribution ofthe outside source to its neighbor's ambient air." 

### Memorandum from G.T. Helms, Chief, Control Programs Operations Branch, OAQPS, U.S. EPA, to Steve Rothblatt, Chief, Air 

### Branch, U.S. EPA. Region V. Ambient Air. 

### April 30, 1987. (pN-110-87-04-30- 083). 11. "Regardless ofwhether any member ofthe public is expected to remain at aparticular placefor a specific period oftime, ambient air

### is defined in terms ofpublic access, not frequency ofaccess, length ofstay, age ofthe person or other limitations." Memorandum from Tyler, D.O., OAQPS, U.S. EPA, to A. Davis, U.S. EPA. Region VI. Definition ofAmbient Air for Lead. May 26, 1983. 12. "We do not think 

### that any ofthe barriers mentioned are sufficient to preclude public access so as to allow the source to dispense'with afence. An example ofan unfenced boundary that would qualify is aproperty line along ariver thatis clearlyposted and regularlypatrolled by security guards." Memorandum from G.T. Helms, Chief, Controlled Programs OperationsBranch, OAQPS, U.S. EPA, to Bruce Miller, Chief, Air

### Programs Branch, U.S. EPA. Region IV. Ambient Air. April 30, 1987. (PN110-87-04-30-082).


### 3-17 April 199313. "Case 2 (Warrick County, IN): This caseinvolves two large sources on both sides of the Ohio River. We agree that receptors should be located over the river since this is a public waterway, notcontrolled by the sources. We also agree thatthe river does indeedfonn a sufficientnatural boundary/barrier and thatfencing is notnecessary, since the policyrequires a fence or otherphysicalbarrier. However, some conditions mustbe met The riverbank mustbe clearly posted and regularlypatrolled by plant security. Itmust be very clearthat the area is notpublic. Any areas where there is any question 

### --i.e., grassy areas, etc.-- should be fenced and marked, even ifthere is only a veryremote possibility that the public would attempt to use this property." Memorandumfrom G.T. Helms, Chief, Control Programs Operations Branch, OAQPS, U.S. EPA, to Steve Rothblatt, Chief, AirBranch, U.S. EPA. Region 

### V. Ambient Air. April 30, 1987. (PN-IlO-87-04-30-083). 14. "Given this conclusion, one could argue, based on the text ofthe relevant regulations and the Clean Air Act, that the PSD increments apply whenever the NAAQS apply, and that both must apply throughout the 'ambient 

### air'. However, the PSD system, unlike the NAAQS system, does not aim at achieving one single goal. Rather it represents a balance struck first by Congress between a given level ofprotection against degradation and a given potential for economic growth. It appears that the calculations on which that balancingjudgment was based all assumed that PSD increments would be measured at ground level." Memorandumfrom Joseph A. Cannon, Assistant Administrator for Air and Radiation, Office ofAir, Noise, and Radiation, to Charles Jeter, Regional Administrator, U.S. EPA. Region IV. Applicability ofPSD Increments to Building Rooftops. June 11, 1984. (PN-165-84- 06-11-014). 15. "Accordingly, I recommend that we infonnAlabamathatwe do not now require that compliance with PSD increments be measured at the tops ofbuildings. A State may, ofcourse, adopt such an approach ifitso desires." Memorandum from Joseph A. Cannon, Assistant Administrator for Air and Radiation, Office ofAir, Noise, and Radiation, to CharlesJeter, Regional Administrator, U.S. EPA. Region IV. Applicability ofPSD Increments to Building Rooftops. June 11, 1984. (PN-165-84- 06-11-014). 16. liAs you correctly pointed out, PSD increment consumption does not apply at the tops ofbuildings." Memorandumfrom G.T. Helms, Chief, Control Programs Operations Branch, OAQPS, U.S. EPA, to Bruce P. Miller, Chief, Air Programs Branch, U.S. EPA. Region 

### IV. Ambient Air Definition. September 21, 1987. (PN-110-87-09-21- 086). 17. "We have never eitherflatly stated that land acquisition in general is acceptable or unacceptable under section 123 ofthe Clean Air Act
. . . we will review individual situations on a case-by-case basis." Memorandum from Tyler, D., OAQPS, U.S. EPA, to I. Dickstein, U.S. EPA. Region 

### Vill. Wyoming--Definition ofAmbient Air. April 7, 1987. 3-18 April 199318. "Allreceptor locations that may affectcontrol strategy requirements, and meet the definition of 'ambient air', must be included in regulatory modeling applications. Ambient air is defined in 40 CPRPart50.I(e) as 'thatportion ofthe atmosphere, external to buildings, to which the generalpublic has access'. Receptorpoints 180 and 197 are adjacent to a roadway to which the public clearly has access; thus, they mustbe included in the SIP modeling analysis. Although siting criteria maypreclude placement ofambient monitors atthesereceptors, as was discussed by Asarco, this does.!!Q!preclude the placement ofmodelreceptors atthese sites." Letterfrom Douglas M. Skie, Chief, AirPrograms Branch,

### U.S. EPA. Region

## vm, to Jeffrey 

### T. Chaffee, Montana Department ofHealth and Environmental Sciences. EastHelena Lead SIP. March 13, 1992.

3-19 April 19934.0 EMISSION INVENTORIES

TO BE PROVIDED

4-1 April 1993

### 5.0 AMBIENT AIR QUALITYMONITORING AND DATA USAGE



### 5.1 GENERAL According to the regulations establishedin 40 CFR Part58, States are required to establish and maintain an air quality surveillance system for the purpose ofmeasuring ambient air concentrations ofthose pollutants for which national ambient air quality standards (NAAQS) have been defined. The network ofmonitoring stations that is to be provided for in State implementationplans is designated as the State and Local 

### Air Monitoring Stations (SLAMS) network. The general SIP monitoring requirements are contained in 40 CFR 58.20 and include the following.1
1. Requirements in Appendices A, C, D, and E of40 CPR Part 58 which pertain to quality assurance for monitoring stations, monitoring methodology, monitoring network design, and probe siting criteria, respectively 

### 2. An annual review ofthe monitoring network to assure that the monitoring objectives as defined in Appendix D ofPart 58 are satisfied 

### 3. Operation ofatleast one station ofthe SLAMS networkperpollutant during any stage ofan airpollution episode 4. Provision of

### a SLAMS network description for public review and submission to the EPA Administrator The SIP itselfdoes not have to contain the network description; however, these must be kept on file at the State agency's office, made available for public inspection, and submitted to the Administrator upon request. A State'sprior SIP submission that covers 

### air quality monitoring in general may meet the requirements for PM-lO SIP's. The Regional Office should determine whether the State'spriormonitoring submission includes PM-lO. If the monitoring submission specifically excludes PM-lO, the SIP mustprovide the necessary information on PM-lO monitoring?·3 Further information on whatthe SIP itselfmustcontain is provided in GuidelinesforImplementation oftheAmbientAirMonitoring Regulations, EPA-450/4-79-038.
5-1 April 1993Any ambient air quality station other than a SLAMS or PSD station from which a State intends to use data for demonstrating attainment or nonattainmentor for computing a design value for control purposes must meet the requirements for SLAMS as described in 40 

### CFR Parts 58.13 and 58.22 as well as the requirements ofAppendices A and E ofPart**58:~** In addition, any ambient air quality station other than a SLAMS orPSD station from which a State intends to use data for SIP-related functions otherthan as part ofan attainment or nonattainment demonstration orfor computing a design value for NAAQS control purposes, need not necessarily satisfy the requirements for a SLAMS station, but must be operatedin accordance with specifications approved by the Regional Administrator.s
Measurement ofmeteorological variables at the location ofan air quality monitoring station provides a basis for correlating air pollutant levels with local weatherpatterns. Meteorological monitoring data are also required for the purposes of air quality modeling. Meteorological inputs to modeling are discussed in Section 6.0 ofthis document.6 Finally, guidelines for sources required to monitor ambient air quality under PSD regulations are contained in theAmbientMonitoring Guidelinesfor Prevention ofSignificant Deterioration (PSD

## Fand general considerations for requiring ambient air monitoring under PSD regulations are contained in theNew SourceReview Workshop Manual (draft}.8 Section 165(e)(2) ofthe Act requires conducting preconstruction air quality monitoring to determine whether emissions from new sources or source modifications located in attainment or unclassifiable areas willresult in exceedance ofthe NAAQS. Section 167(a)(7) ofthe Act gives EPA the discretion to require postconstruction air quality monitoring to determine the ambient air quality impacts from emissions ofnew sources or source modifications on such areas.7 Under PSD regulations, source applicants are generally required to collect ambient air quality data for 1year, but EPA has the discretion to allow a shorter collecting period (not less than 4 months) ifthe resulting data can demonstrate a complete analysis ofthe ambient air quality impacts the source will have on the area. Source applicants must also use quality assurance procedures pursuantto Appendix 

### B of40 

### CFR Part 58 in order to ensure the accuracy and precision ofthe data collected.8• 9 EPA requirements for incorporating PSD provisions in SIP's are contained in 40 

### CFR Part 51.166.

5-2 April 1993

### REFERENCES FOR SECTION 5.1

1. U.S. Environmental Protection Agency. Code of FederalRegulations. Title 40, ChapterI, Subchapter C, Pan 58.20. July 1, 1991. 2. U.S. Environmental Protection Agency. PM-10 SIPDevelopment Guideline. Office of Air QualityPlanning and Standards, Research Triangle Park, North Carolina. EPA450/4-87-013. June 1987. Section 3.0. 3. "Any ambient air quality monitoring station otherthan a SLAMS orPSD station from which the State intends to use the data as part ofa demonstration ofattainment or nonattainment orin computing a design value for control purposes ofthe National Ambient Air Quality Standards (NAAQS) must meetthe requirements for SLAMS described in section 58.22 and, after January 1, 1983, must also meet the requirements for SLAMS as described in section 58.13 and Appendices A andE to this part." U.S. Environmental Protection Agency. Code ofFederalRegulations. Title 40, ChapterI, Subchapter C, Part 58.14 (a)
. July 1, 1991. 4. "The State shall adopt and submit to the Administrator a revision to the plan which will:
... (e) Provide for having a SLAMS network description available for public inspection and submission to the Administrator upon request." U.S. Environmental Protection Agency. Code ofFederalRegulations. Title 40, ChapterI, Subchapter C, Pan 58.20(e). July 1, 1991. 5. "Any ambient air quality monitoring station other than a SLAMS or PSD station from which the State intends to use data for SIP-related functions other than described in paragraph (a) ofthis section is not necessarily required to comply with the requirements ofa SLAMS station under paragraph (a) but must be operated in accordance with a monitoring schedule, methodology, quality assurance procedures, and probe orinstrument-siting specifications approved by the Regional Administrator." U.S. Environmental Protection Agency. Code of FederalRegulations. Title 40, Chapter I, Subchapter C, Part 58.14 (b). July 1, 1991 6. U.S. Environmental Protection Agency. On-site Meteorological Program Guidance for RegulatoryModeling Applications. PB87-227542. June 1987. 7. "The court ruled that section 165(e)(2) ofthe Clean Air Act requires that continuous preconstruction air quality monitoring data must be collected to determine whether emissions from a source will result in exceeding the National Ambient Air Quality Standards (NAAQS)
..." U.S. EPA. AmbientMonitoring Guidelinesfor Prevention ofSignificantDeterioration (PSD). Office ofAir Quality Planning and Standards, Research Triangle Park, NC. EPA Publication No. EPA-450/4-87-007. May 1987. page 3.
5-3 April 19938. "(m)(1)(iv) The plan shallprovide that, in general, the continuous air monitoring data that is required shall have been gathered over a period ofone year . . . except that, if the reviewing authority determines that a complete and adequate analysis can be accomplished with monitoring data gathered over aperiod shorterthan one year (but notto be less than four months)
... (m)(3) The plan shallprovide that the owner or operator ofa major stationary source ormajormodification shall meet the requirements ofAppendix B to Part 58 ofthis chapter
..." U.S. Environmental Protection Agency, 

### Code of FederalRegulations. Title 40 ChapterI, Subchapter C, Part 51.166. July 1, 1991. 9. U.S. Environmental Protection Agency. 

### New Source Review Workshop Manual. Draft document Office ofAir Quality Planning and Standards, Research Triangle Park, North Carolina. October 1990.

5-4 April 1993

### 5.2 QUALITYASSURANCE Quality Assurance requirements for SLAMS networks are contained inAppendix A of 40 CFR Part 58, and requirements for PSD monitoring are contained in Appendix B of40 CFR Part 58. The requirements in Appendix A are generalin nature in order to allow each State the opportunity to develop the mostefficient and effective quality assurance system for its specific circumstances.1 Accuracy and precision tests for both manual and automated PM10 sampling are the essence ofthe quality assurance system established. Theresults ofall valid precision and accuracy tests must be reported on a quarterly basis to the Atmospheric Research and Exposure Assessment Laboratory (AREAL) (formerly the Environmental Monitoring Systems Laboratory (EMSL)). A list ofall PM-IO monitoring sites and their Aerometric Information Retrieval System (AIRS) site identification codes shall be kept updated and on file with the appropriate EPA Regional Office and with AREAL.1 AIRS was formerly known as the Storage and Retrieval ofAerometric Data (SAROAD) system. The quality assuranceprocedures ofAppendix A of40 CFR Part 58 do not cover PM10 methods other than the reference method defined in Appendix J ofPart50 (see Section 5.3 ofthis document) or equivalent methods designated in accordance with Part 53. Other methods may be allowed for conducting PM-lO episode monitoring. Episode monitoring is discussed in Section 5.6 ofthis document. States will need to develop their own quality assurance procedures for those methods not defined in Appendix 

### J. Such procedures should be similar or analogous to those procedures described in Section 3.0 ofAppendix A for the PM-lO reference method.2 Primary guidance for developing the quality assurance program for ambient air monitoring isprovided in the QualityAssuranceHandbookforAirPollution-Measurement Systems, Volume I

- Principles (EPA-600/9-76-005), and in the QualityAssuranceHandbook forAirPollution Measurement Systems, Volume II

-AmbientAirSpecific Methods (EPA600/4-77-027a). These documents contain suggested procedures, checks, and control specifications. Specifically, section 2.11.0 provides quality assurance procedures for the reference method for determination ofparticulate matter as PM-lO in the atmosphere (High Volume PM-lO Sampler Method). As a minimum, each quality assurance programmust include operational procedures for the following activities:3

5-5 April 19931. Selection ofmethods, analyzers, or samplers 2. Training 3. Equipmentinstallation 4. Selection and control ofcalibration standards 5. Calibration procedures andfrequency 6. Zero/span checks and adjustments ofautomated analyzers 7. Control checks and their frequency 

### 8. Controllimits for zero, span, and other control checks, and respective corrective actions when such limits are surpassed 9. Calibration and zero/span checks for multiplerange analyzers 10. Preventive andremedial maintenance 11. Recording and validating data 12. Dataquality assessment (precision and accuracy) 

### 13. Documentation ofquality control information Generally, standards used for ambient air monitoring quality assurance must be traceable to standards or devices certified by the National Institute ofStandards Technology (NIST), or other approved reference material. Flow and mass standards used for PM-lO sampling and analysis must be traceable to the NIST.4 Agencies operating SLAMS network stations are subjectto annual EPA systems audits oftheir ambient air monitoringprogram and are required to participate in EPA's National Performance Audit Program.5 Auditprocedures are described in section 

### 1.4.16 ofthe Quality AssuranceHandbookforAirPollution Measurement Systems, Volume I

- Principles (EPA600/9-76-005). The EPA's NationalPerformance Audit Program is described in section 2.0.10 ofthe QualityAssuranceHandbookforAirPollution Measurement Systems. Volume II

-AmbientAirSpecific Method. Systems audit criteria and procedures are given in section 2.0.11 ofthe same document.

5-6 April 1993

### REFERENCES FORSECTION 5.2

1. U.S. Environmental Protection Agency. Code of FederalRegulations. 

### Title 40, Chapter I, Subchapter C, Part 58, Appendix A. July 1, 1991 2. "4.2 Quality Assurance. PM-lO

### methods other than the reference method are not covered under the quality assessmentrequirements ofAppendix A. Therefore, States mustdevelop and implement their own quality assessmentprocedures for those methods allowed underthis section 4. 

### These quality assessmentprocedures should be similar or analogous to those described in 

### section 3 

### ofAppendix A for the PM-lO 

### reference method." U.S. Environmental Protection Agency. Code of Federal Regulations. 

### Title 40, Chapter I, Subchapter C, Part58, Appendix C July 1, 1991. 3. 

### U.S. Environmental Protection Agency. Code of FederalRegulations. 

### Title 40, 

### Chapter I, Subchapter C, Part 58, Appendix A. 

### Section 2.2. July 1, 1991. 4. 

### U.S. Environmental Protection Agency. Code of FederalRegUlations. 

### Title 40, 

### Chapter I, Subchapter C, Part 58, Appendix A. 

### Section 2.3. July 1, 1991. 5. 

### U.S. Environmental Protection Agency. Code of FederalRegulations. 

### Title 40, Chapter I, Subchapter C, Part 58, Appendix A. 

### Section 2.4. July 1, 1991.

5-7 

### April 1993

### 5.3 AMBIENT MONITORING METHODOLOGY

5.3.1 General The reference or equivalentmethods which must be used in the monitoring methods used in SLAMS networks are defined in 40 CFRPart 50.1 and are listed inTable 5-1. 1


### TABLE 5-1. MANUAL AND AUTOMATED METHODS APPROVED AS OF FEBRUARY 14, 1992 Manual Reference Methods Wedding & Associates PM-10 Critical Flow HV Sampler Sierra-AndersenlGMW 1200 Sierra-Andersen/GMW 321-B Sierra-Andersen/GMW 32l-C Oregon DEQMV Special Sampler Sierra-AndersenlGMW 241 & 241M Dichot Sampler 

### Automated EquivalentMethods Andersen Inst. FH62I-N PMlO Beta Attenuation Monitor Rupprecht & PatashnickTEOM Series 1400 PM-1O Monitor Wedding & Associates PM-lO Beta Gauge Automated Particle Sampler

The reference method to be used for measuring ambient concentrations ofPM-lO to determine compliance with the primary and secondary NAAQS, as specified in 40 CFRPart 50.6, is contained in Appendix J to 40 CFR Part 50.2
In general, the reference method is based on selection ofparticulate matter with an aerodynamic diameter ofless than or equal to a nominal 10 micrometers by inertial separation, followed by filtration and gravimetric determination ofthe PM-lO mass on filter substrate. Inpractice, high-volume air samplers with a size selective inlet are used for most sampling for ambient PM-lO concentrations.2

5-8 April 1993SLAMS data collected after August I, 1988 are not allowed to include datafrom nonreference method samplers. In the event that a nonreference method sampleris designated as a reference sampler withoutfurther future modification, all historical data produced by that sampler are retroactively defined as dataproduced by a reference sampler.3 

### In addition, at collocated sample sites, datafrom reference samplers are always precedent over data from nonreference samplers. Ifmultiple samplers are collocated for data quality assessment purposes (i.e., precision and accuracy) similar sampler types mustbe used, and one sampler must be designated apriori for datareporting purposes as defined in Appendix A of40 CFR Part 58. 

### In situations where more than one type ofsampler is used by areporting organization, collocated precision sites should be established for each sampler type.4
The air quality regulations allow the use, for a period oftime determined by the Administrator, ofany manual method or analyzer purchased priorto cancellation ofits reference or equivalentmethod designation in 40 CFR 53.11 or40 CFR 53.16.5 Certain allowances are also made, for samplers with more than one range and in specific geographical

### areas**~** for methods with higher, nonconforming measurementranges.6 No reference method or equivalentmethod that has been modified in a manner that will, ormight, significantly alter the perfonnance characteristic ofthe method, may be used in a SLAMS network without prior approval by the Administrator.7 Finally, additional requirements pertaining to ambient monitoring methodology and data usage under PSDregulations are contained inAmbientMonitoring Guidelinesfor Prevention ofSignificantDeterioration. 8



### 5.3.2 Sampling Schedule From an historical perspective, the sampling interval for PM-lO monitors consisted of a short-term and long-term sampling strategy as prescribed by 40 CFR Part 58.13. In general, the short tenn strategy was used during the first full year of sampling and required daily sampling (at a site designated as the site ofexpected highest concentration) in Group I areas, every other day in Group IT areas, and once every six days in Group illareas. The longtenn sampling strategy occurred after the short-tenn strategy ended (in mostcases after the first full year ofsampling), and the sampling interval varied according to the relationship of air quality levels to the NAAQS. For most PM-lO areas in the United States, itislikely that
5-9 April 1993the short-term sampling requirements have been met and the long-term sampling strategy is currentlyin effect. The current sampling schedule requirements for ambient concentrations ofPM-lO are as follows:9


### • In those areas in which the short-term (24-hour) standardis controlling (i.e., has the highestratio ofdesign concentration atthe site to the NAAQS) the sampling interval isprescribed in Figure 1 ofPart 58.13 (the prescribed sampling intervals are once every day, once every other day, or once every six days). 

### In general, Figure 1 shows that the closer the air quality levels are to the NAAQS, the greater the sampling frequency required
• In areas in which the annual standard is the controlling standard, the minimum sampling period for all monitors in a given area is once every six days The sampling interval for ambientPM-lO monitors under PSD regulations are consistent with the Part 58 regulations for SLAMS networks.lo



### 5.3.3 Data Completeness According to 40 CFR Part 50, Appendix K, for PM-la, all dataproduced by the National Air Monitoring Stations (NAMS) and SLAMS networks are required to be used in making comparisons with the PM-IO NAAQS and a minimum of75 percent ofthe scheduled PM-1O samples per quarter arerequired. ll For monitors used in PSD networks, a minimum of 80 percent ofthe individual 24-hourly values for manual methods should be reported in any sampling period. 12



### 5-10 April 1993REFERENCES FOR SECTION 

### 5.3

1. "(f) 

### Reference method means a method ofsampling and analyzing the ambient air

### for an air

### pollutantthat is specified as a reference method in an appendix to this part, or a method that has been designated as areference method in accordance with part 53 of this chapter; it

### does notinclude a method for which a reference method designation has been canceled in accordance with 53.11 or 53.16 ofthis chapter." and "(g) Equivalentmethod means a method ofsampling and analyzing the ambient air

### for an air

### pollutantthat has been designated an equivalentmethod in accordance with part 53 ofthis chapter; 

### itdoes notinclude a method for which an equivalent method designation has been canceled in accordance with 53.11 or 53.16 ofthis section." U.S. Environmental Protection Agency. Code ofFederalRegulations. Title 40, Chapter I, Subchapter C, Part 50.1. (f) 

### and (g). July

-I, 1991. 2. U.S. Environmental Protection Agency. Code of FederalRegulations. Title 40, Chapter I, Subchapter C, Part 50, Appendix 1. 

### July 1, 1991 3. "If

### a nonreference sampler withoutfurther modification is designated as areference sampler in the future, then all 

### ofits historical data is retroactively defined as data produced by areference sampler" Memorandum from Gerald Emison, Director, OAQPS, U.S. EPA, to Distribution. Revision to Policy on the Use ofPM-lO Measurement Data. November 21, 1988. 4. "In 

### the event that more than one PM-lO sampler is operating concurrently at a location, data from reference method samplers always takes precedence over data from nonreference samplers. If

### multiple samplers are collocated for data quality assessmentpurposes (i.e., 

### precision and accuracy), similar sampler types mustbe used and one sampler must be designated apriori for data reporting purposes (Appendix A to 40 CFR 58). Furthermore, ifmore than one type of sampler is used by areporting organization, collocated precision sites should be established for each sampler type." Memorandumfrom Gerald Emison, Director, OAQPS, U.S. EPA, to Distribution. Revision to Policy on the Use ofPM-lO Measurement Data. November 21, 1988. 5. "2.3 Any manual method or analyzerpurchased prior to cancellation ofits reference or equivalent method designation under 53.11 or 53.16 ofthis chapter may be used in a SLAMS following cancellation for areasonable period oftime to be determined by the Administrator." U.S. Environmental Protection Agency. Code of Federal Regulations. Title 40, Chapter I, Subchapter C, Part58, Appendix C. July 1, 1991. 6. "2.6 Use ofMethods with Higher, Nonconforming Ranges in Certain Geographical Areas
... 2.6.2 Nonconforming ranges. An analyzer may be used (indefinitely) on a range which extends to concentrations higher than two times the upper limit specified in Table B-1 ofPart 53 ofthis chapter if
..." 

### U.S. Environmental Protection Agency.
5-11 April 1993Code of FederalRegulations. Title 40, Chapter I, Subchapter C, Part 58, Appendix C. July 1, 1991. 7. "2.8 Modifications ofMethods by Users. 2.8.1 Except as otherwiseprovided in this section (2.8), noreference method; equivalentmethod, or alternative method may be used in a SLAMS if

### ithas been modified in a manner that will, ormight, significantly alter the perfonnance characteristics ofthe method withoutprior approval by the Administrator." U.S. Environmental Protection Agency. Code of FederalRegulations. Title 40, ChapterI, Subchapter C, Part58, Appendix C. July 1, 1991. 8. U.S. Environmental Protection Agency. AmbientMonitoring Guidelinesfor Prevention ofSignificantDeterioration (PSD

### J. Office ofAir QUality Planning and Standards, Research Triangle Park, NC. EPA-450/4-87-007. May 1987. 9. U.S. Environmental Protection Agency. Code of FederalRegulations. Title 40, ChapterI, Subchapter C, Part 58.13. July 1, 1991. 10. "2.7 Frequency ofSampling
...The frequencies discussed below are consistent with the Part 58 sampling frequencies." U.S. Environmental Protection Agency. Ambient Monitoring GuidelinesforPrevention of SignificantDeterioration (PSD). Office of Air Quality Planning and Standards, Research Triangle Park, NC. EPA-450/4-87-007. May 1987. 11. "2.3
...For the purposes ofmaking comparisons with the particulate matter standards, all data produced by National 

### Air Monitoring Stations (NAMS), State and Local Air Monitoring Stations (SLAMS) and other sites submitted to EPA in accordance with the Part 58 requirements mustbe used, and a minimum of75 percent ofthe scheduled PM-I0 samples perquarter are required." U.S. Environmental Protection Agency. Code ofFederalRegulations. Title 40. Part 50, Appendix K. Interpretation ofthe National Ambient Air Quality Standards for Particulate Matter. June 1990. 12. "8.1 Air quality Data Reporting
... Formanual methods, 80 percent ofthe individual 24-hour values should be reported in any samplingperiod." U.S. Environmental Protection Agency. AmbientMonitoring Guidelinesfor Prevention of SignificantDeterioration (PSD). Office ofAir Quality Planning and Standards, Research Triangle Park, NC. EPA-450/4-87-007. May 1987.

5-12 April 1993

### 5.4 NETWORK DESIGN Appendix 0 of

### 40 CFR Part58 provides general criteria for
.establishing SLAMS networks and for selecting new monitoring stations. EPA employs these criteria in evaluating the adequacy ofSLAMS networks. In general. SLAMS networks should be designed to comply with four basic monitoring objectives:1
1. To determine the highest concentrations expected to occurin the area encompassed by the network 2. To determine representative concentrations in areas ofhigh population density 3. To determine the impacts on ambientpollution levels ofsignificant sources or source categories 4. To determine general background levels Proper siting ofa monitoring station requires exact specification ofthe monitoring objective and commonly involves a definition ofa spatial scale ofrepresentativeness.2 Appendix 0 states that the goal in siting monitoring stations is to correctly match the spatial scale that the sample ofmonitored 

### airrepresents with the spatial scale most appropriate for the monitoring objective ofthe station.3 The mostimportant spatial scalesrepresented for PM-lO SLAMS monitoring networks are the micro, middle and neighborhood scales. For establishing SLAMS networks to represent large homogeneous areas other than the above scales ofrepresentativeness, urban orregional scales would also be needed.4 It should be noted that in order for States to use receptor modeling for control strategy demonstrations, the following considerations pertaining to spatial scales ofrepresentativeness in network design must be addressed:5

• PM-lO monitoring networks must be designed in orderto monitor the maximum air qUality impacts from the predominant sources (i.e., around 

### 90 percent) and source categories in the PM-lO emissionsinventory

5-13 April 

### 1993• For ambientimpacts ofPM-lO emissions from anti-skid materials used inroad surfaces, the PM-lO monitoring networks must be designed in accordance with EPA's monitoring guidance and spatiallyrepresentative ofthe maximum air quality impacts from that source category

• In situations where the 24-hour NAAQS is controlling, monitoring networks must collect samples at such frequent intervals which ensure that emissions impacts from the predominant sources are being monitored adequately
In addition to Appendix D, further information pertaining to designing PM-lO networks and siting ambient samplers is contained in

### NetworkDesign and Optimum Site Exposure CriteriaforParticulateMatter. 6 Questions and answers pertaining to ambient monitoring network design for PM-lO are contained in

### Response to QuestionsRegarding PM10 State Implementation Plan (SIP) Development.7
In designing ambient monitoring networks under PSD regulations, such factors as topography, climatology, population, and existing emission sources mustbe considered; therefore, the ultimate design ofthe network will be determined on a case-by-case basis by the pennitting authority.8 

### In general, ambient networks under PSD are designed during a preconstruction phase and a post-construction phase. Forboth the preconstruction phase and the post-construction phase, the number and location ofmonitors will be determined through appropriate dispersion modeling techniques. In addition, the number ofmonitors will depend on the expected spatial variability ofthe pollutantin the area being studied (i.e., the higher the spatialvariability ofthe pollutantunder study, the greater the number ofmonitors needed in that area).9 During thepreconstructionphase, the monitors should be (l) located in the area of maximum concentration increase expected from the proposed source or modification; (2) located in the area ofthe maximum expected concentrations from emissions ofexisting sources; and (3) located in the area ofmaximum impact ofthe pollutant from the combination effect ofexisting SOQI"ces and the proposed source or modification. In most multisource settings, one to four sites would be sufficient. Forremote settings (i.e., in areas with no significant existing sources), a minimum number ofmonitors would need to be located 

### (i.e., one or two atthe most). Where industrial process fugitive particulate emissions are involved,

5-14 April 1993a monitor should be located atthe proposed source site and a downwind location would also need to be sited ifstack emissions are also involved. 10
Forthe postconstruction phase, two or three sites would probably be sufficient for most situations involving multi-source areas. Forremote areas, one ortwo sites would be sufficient.11 Appendix B of40 CFRPart 58 specifies the minimum quality assurance requirements for controlling and assessing the quality ofthe PSD ambient air monitoring data submitted to EPA by organizations operating a network ofPSD stations. Onerequirementis thatfor a given organization's monitoring network, one sampling site oughtto have collocated samplers. 12 For each pair ofcollocated samplers, one sampler will be designated as the sampler to be used to report air quality for the site and the second sampler willbe designated as the duplicate sampler. The difference in measured concentration between each pair of collocated samplers will be used to calculate precision ofthe PM-lO manual method. 12 Monitors should be located in areas which satisfy the definition ofambient air. According to 40 CFR 50.1(e), ambient airis defined as "thatportion ofthe atmosphere, external to buildings, to which the generalpublic has access." The definition ofAmbient Air as well as related issues such as location and time aspects, public access, PSD considerations, and land acquisition are discussed in detail in Section 3.2 ofthis document. In situations where modeled locations are in areas excluded from the ambient air, the monitors should be located downwind at the boundary ofthat area. 13

5-15 April 1993

### REFERENCES FORSECTION5.4

1. "The network ofstations which comprise SLAMS should be designed to meeta minimum offour basic monitoring objectives. These basic objectives are: (1) To detennine highest concentrations expected to occur in the area covered by the network; (2) to detenninerepresentative concentrations in areas ofhigh population density; (3) to detennine the impact on ambientpollution levels ofsignificant sources or source categories; and (4) to determine general background concentration levels." U.S. Environmental Protection Agency. 

### Code of FederalRegulations. Title 40. Part 58, Appendix D. "NetworkDesign for State and Local AirMonitoring Stations (SLAMS) and National Air Monitoring Stations (NAMS)" 1. SLAMS Monitoring Objectives and Spatial Scales. July 1, 1990. 2. "Proper siting ofa monitoring station requires precise specification ofthe monitoring objective which usually includes a desired spatial scale ofrepresentativeness." U.S. Environmental Protection Agency. 

### Code of FederalRegulations. Title 40, ChapterI, Subchapter C, Part 58, Appendix D. "NetworkDesign for State and Local Air Monitoring Stations (SLAMS) and National AirMonitoring Stations (NAMS)" 1. SLAMS Monitcring Objectives and Spatial Scales. July I, 1990. 3. "The goal in siting stations is to correctly match the spatial scale represented by the sample ofmonitored air with the spatial scale most appropriate for the monitoring objective ofthe station." U.S. Environmental Protection Agency. 

### Code of Federal Regulations. Title 40, Chapter I, Subchapter C, Part58, Appendix D. "Network Design for State and Local Air Monitoring Stations (SLAMS) and National Air Monitoring Stations (NAMS)" 1. SLAMS Monitoring Objectives and Spatial Scales. July 1, 1990. 4. "The most important spatial scales to effectively characterize the emissions ofPM-lO from both mobile and stationary sources are the micro, middle, and neighborhood scales. For purposes ofestablishing monitoring stations to represent large homogeneous areas other than the above scales ofrepresentativeness, urban or regional scale stations would also be needed." U.S. Environmental Protection Agency. 

### Code ofFederalRegulations. Title 40, Chapter I, Subchapter C, Part 58, Appendix D. "NetworkDesign for State and Local Air Monitoring Stations (SLAMS) and National Air Monitoring Stations (NAMS)" 2.7 Lead. July 1, 1990. 5. "The PM-lO monitoring network must be representative ofthe maximum air quality impacts from the predominant (i.e., generally on the order of90 percent) sources and sourcecategories in the PM-lO emission inventory
... 

### In a few areas, emissions of antiskid materials from a small number ofroad surfaces constitute thepredominant PM-lO source category. These emissions should be unifonnly distributed along these road surfaces. The monitoring network must be shown to be in accordance with EPA's monitoring guidance and spatially representative ofthe maximum air quality 5-16 April 1993

### impactfrom this source category .. , If

### the 24-hour NAAQS iscontrolling, the networkmust have samples collected at sufficiently frequent intervals to ensure that the impacts from the governing emission sources are adequately monitored." Memorandum. Bauman, RobertD., Chief, SOJParticulate Matter Programs, Branch, U.S. EPA, and Joseph A. TIkvart, Chief, Source Receptor AnalysisBranch, U.S. EPA, to Chief, Air 

### Branch, U.S. EPA. Regions I-X. PM-lO SIP Demonstration for Small Isolated Areas with Spatially Uniform Emissions. July 5, 1990. 6. U.S. Environmental Protection Agency. NetworkDesign and Optimum Site Exposure CriteriaforPaniculateMatter. 

### Office ofAir Quality Planning and Standards. Research Triangle Park, N.C. EPA-450/4-87-009. May 1987. 7. U.S. Environmental Protection Agency. Responses to QuestionsRegarding PM-IO StateImplementation Plan (SIP) Development. 

### Office ofAir Quality Planning and Standards, Research Triangle Park, N.C. June 1988. 8
. "3.1 Network Design. The design ofa network for criteria and noncriteria pollutants will be affected by many factors such as topography, climatology, population, and existing sources. Therefore, the ultimate design ofa networkfor PSD purposes must be decided on a case-by-case basis by the permit granting authority." U.S. Environmental Protection Agency. AmbientMonitoring GuidelinesforPrevention of SignificantDeterioration (PSD). 

### Office ofAir Quality Planning and Standards, Research Triangle Park, NC. EPA-450/4-87-007. May 1987. 9. "3.2.2. As discussed above for preconstruction monitoring, appropriate dispersion modeling techniques are used to estimate the location ofthe air 

### quality impact ofthe new source or modification. Monitors should then be placed at (a) the expected area ofthe maximum concentrations from the new source or modification, and (b) the maximum impact area(s), i.e., 

### where the maximum pollutantconcentration will occur based on the combined effect ofexisting sources and the new source or modification

. .. 3.2 Number and Location ofMonitors
...Generally, the number ofmonitors will be higher where the expected spatial variability ofthe pollutantin the area(s) ofstudy is higher." U.S. Environmental Protection Agency. AmbientMonitoring Guidelines forPrevention ofSignificantDeterioration (PSD). 

### Office ofAir Quality Planning and

Standards, Research Triangle Park, NC. EPA-450/4-87-007. May 1987. 10. "3.2.1 Preconstruction Phase.
.. This would provide sufficient infonnation for the applicantto place a monitor at (a) the location(s) ofthe maximum concentration increase expected from the proposed source or modification, (b) the location(s) ofthe maximum air 

### pollutantconcentration from existing sources ofemissions, and (c) the location(s) ofthe maximumimpact area, i.e., 

### where the maximum pollutant concentration would hypothetically occur based on the combinationeffect ofexisting sources and the proposed new source or modification
... Generally, one to four sites would cover most situations in multisource settings. For remote areas in which the permit granting authority has determined that there are no significant existing sources, a minimum number ofmonitors would be needed, 

### i.e., one orprobably two at the 

### 5-17 April 1993

### most. .. When industrial process fugitive particulate emissions are involved, the applicant should locate a monitor atthe proposed source site. H stack emissions are also involved, a downwind location should also be selected." U.S. Environmental Protection Agency. AmbientMonitoring GuidelinesforPrevention ofSignificant Deterioration (PSD). 

### Office ofAir 

### Quality Planning and Standards, Research Triangle Park, NC. EPA-450/4-87-007. May 1987. 11. "3.2.2 Postconstruction Phase
. .. Generally, two or three sites would be sufficient for most situations in multisource areas. In

### remote areas where there are no significantexisting sources, one or two sites would be sufficient." U.S. Environmental Protection Agency. AmbientMonitoring GuidelinesforPrevention of Significant Deterioration (PSD). 

### Office ofAir 

### Quality Planning and Standards, Research Triangle Park, NC. EPA-450/4-87-007. May 1987. 12. "3.3.1 TSP and PM-lO Methods.
.. A site with the highest expected 24-hour pollutant concentration must be selected. The two samplers must be within 4 meters ofeach other but at least2 meters apart to preclude airflow interference. The collocated samplers must be operated as a minimum every third day when continuous sampling is used. When a less frequent sample schedule is used, the collocated samplers must be operated atleast once each week." U.S. Environmental Protection Agency. Code of FederalRegulations. 

### Title40, Chapter I, Subchapter C, Part 58, Appendix B. 

### "Quality Assurance Requirements for Prevention ofSignificant Deterioration (PSD) Air Monitoring." 3.3 Precision ofManual Methods. July 1, 1992. 13. "3.2.3 Special Concerns for Location ofMonitors.
.. However, monitors should be placed in those locations satisfying the definition ofambient air. Ambient air 

### is defined in40 CFR 50.I(e) as "thatportion ofthe atmosphere, external to buildings, to which the general public has'access." Therefore, if

### the modeled locations are within an area excluded from ambient air, the monitors should be located downwind at the boundary ofthat area." U.S. Environmental Protection Agency. AmbientMonitoring GuidelinesforPrevention ofSignificantDeterioration (PSD). 

### Office ofAir Quality Planning and Standards, Research Triangle Park, NC. EPA-450/4-87-007. May 1987.

5-18 April 1993

### 5.5 

### PROBE SITING CRITERIA The criteria for determining the correct siting ofPM-lO samplers are discussed in Appendix E of40 CFR Part58. 1 

### The criteria are similar to the previous siting criteriafor high-volume samplers used in the TSP networks. The new criteria for PM-lO networks include microscale stations which were notpreviouslyrequired for the TSP SLAMS networks.2


### For the microscale stations, an inlet height of2 to 7 meters is specified. For all other scales, the inlet height for PM-lO stations is 2 to 15 meters. Spacing requirements from roadways as specified in Part58, Appendix E are as follows: 3



### • Microscale stations - 5 to 15 meters from major roadways
• Middle, neighborhood, and urban scale stations - arange ofseparation distances are specified for each as afunction oftraffic volume and the scale ofrepresentativeness. (This range of separation distances is contained in Appendix E ofPart 58, section 8, Figure 2.) When placed on the tops ofbuildings, samplers must be located at least 2 meters from walls, with no furnace or incineration flues nearby. The samplers should be placed atleast 20 meters from trees and must be 10 meters from the drop line when the tree(s) acts as an obstruction. The sampler must be located away from obstacles such as buildings, so thatthe distance between obstacles and the samplers is atleast twice the height thatthe obstacle protrudes above the sampler, except for street canyons sites. Exceptfor street canyon sites, there must be unrestricted airflow in an arc ofat least 270 degrees around the sampler.4 

### These criteria must be adhered to as strictly as possible. In 

### the event that the siting criteria cannot be met, a written requestfor a waiver must be madejustifying the differences in the proposed siting criteria.s Section 10 ofAppendix E gives the conditions under which EPA would consider an application for waiver from these siting criteria. The criteria**fo~**

### determining the correct siting ofambient PM-1O samplers under PSD regulations are the same as those contained in Appendix E to Part 58 with the exception that there are no requirements pertaining to considerationsregarding scales ofrepresentativeness when locating the sampler inlet.6



### 5-19 April 1993

### REFERENCES FOR SECTION 5.5 1. U.S. Environmental Protection Agency. Code of FederalRegulations. 

### Title 40, ChapterI, Subchapter C, Part 58, Appendix E. "Probe Siting Criteria for Ambient Air Quality Monitoring."8. Particulate Matter (PM-1O). July 1, 1992. 2. "3.2.6 Sampler Inlet Siting
...The new criteriafor the PM-lO SLAMS include microscale stations which were notpreviouslyincluded for the TSP SLAMS network." U.S. Environmental Protection Agency. PM-IO SIPDevelopment Guideline. 

### EPA450/2-86-001. June 1987. 3. "3.2.6 Sampler Inlet Siting
...An inletheight of2 to 7 meters is specified for PM-lO microscale stations. The inlet heightfor all other scales for PM-1O stations is 2 to 15 meters as itwas previously for all TSP SLAMS. The spacing requirementfrom roadways is also different. For microscale roadway stations, the PM-1O sampler must be between 5 to 15 meters from majorroadways. For middle, neighborhood, and urban scale PM-10 stations arange ofseparation distances are specified for each as a function oftraffic volume and the scale ofrepresentativeness." U.S. Environmental Protection Agency. PM-IO SIP Development Guideline. 

### EPA-450/2-86-001. June 1987. 4. "If

### the sampler is located on aroofor other structure, then there must be a minimum of2 meters separation from wails, parapets, penthouses, etc. No furnace or incineration flues should be nearby
...Therefore, the sampler should be placed at least 20 meters from the dripline and must be 10 meters from the dripline when the tree(s) acts as an obstruction. The sampler must also be located away from obstacles such as buildings, so thatthe distance between obstacles and the sampleris at leasttwice the height that the obstacleprotrudes above the sampler except for street canyon . sites
...There must be unrestricted airflow in an arc ofat least 2700 

### around the sampler exceptfor street canyon sites." U.S. Environmental Protection Agency. Code of FederalRegulations. 

### Title 40, Chapter I, Subchapter C, Part 58, Appendix E. "Probe Siting Criteria for Ambient Air Quality Monitoring."8.2 Spacing From Obstructions. July 1, 1992. 5. "The probe siting criteria as discussed below must be followed to the maximum extent possible. Itis recognized that there may be situations when the probe siting criteria cannot be followed. If

### the siting criteria cannotbe met, this must be thoroughly documented with a written request for a waiver which describes how and why the siting criteria differ." U.S. Environmental Protection Agency. Code of Federal Regulations. 

### Title 40, Chapter I, Subchapter C, Part 58, Appendix E. "Probe Siting Criteria for Ambient Air 

### Quality Monitoring." 1. 

### Introduction. July 1, 1992.

5-20 April 19936. U.S. Environmental Protection Agency. AmbientMonitoring Guidelinesfor Prevention of SignificantDeterioration (PSD). 

### Office ofAir Quality Planning and Standards, Research Triangle Park, NC. EPA-450/4-87-007. May 1987. Section 3.3.2.

5-21 April 1993 

## ,5.6 EPISODE MONITORING Episode contingencyplans are used to prevent airpollution levels from reaching levels which would cause imminent and substantial endangerment to the health ofthe general public.l Suchplans are required pursuant to section 1l0(a)(2)(g) ofthe amended Act. Classification ofregions required to have airpollution episode contingency plans is discussed in 40 CFRPart51 SubpartH. The definition ofan air qUality emergency and the level of PM-lO associated with itare defined in Appendix L ofPart 51. In general, 40 CPR Part 51.152 states that each State contingencyplan must satisfy the following:2
• Specify two or more stages ofepisode criteria, as set forth in Appendix L, or their equivalent
• Provide for public announcement whenever any episode stage has been determined to exist
• Specify adequate emission control actions to implement at each episode stage Section 4.0 ofAppendix C ofPart 58 describes the sampling procedures to be used for determining airquality levels during airpollution episodes.3 These procedures are further described in GuidelineforPM-IO Episode Monitoring Methods.4 

### In general, two methods based on the filtration principle are recommended. They are the staggered sampling procedure and the short-term interval sampling method. The staggered sampling procedure uses a 24-hour sampling procedure followed by a 2-hourpost sampling filter equilibration period. The short-term interval sampling method requires a 4-hour sampling period followed by a 2-hour filter equilibration period. In addition to these two procedures, other methods may be used provided the user demonstrates a site-specific correlation ofthe alternative method with the reference method.s

5-22 April 1993

### REFERENCES FOR SECTION 5.6

1. "The exampleregulations presented hereinreflect generally recognized ways of preventing air

### pollution from reaching levels that would cause imminent and substantial endangerment to the health ofpersons." U.S. Environmental Protection Agency. Code of FederalRegulations. 

### Title 40, ChapterI, Subchapter C, Part 51, Appendix L. 

### July 1, 1991. 2. "(a) Each contingency plan must
- (1) Specify two or more stages ofepisode criteria such as those setforth in Appendix L to this Part, or their equivalent; (2) Provide for public announcementwhenever any episode stage has been detennined to exist; and (3) Specify adequate emission control actions to be taken ateach episode stage." U.S. Environmental Protection Agency. Code ofFederalRegulations. 

### Title 40, Chapter I, Subchapter C, Part 51.52. July 1, 1991. 3. "4.1. For short-term measurements ofPM-lO during air 

### pollution episodes the measurement method mustbe: 4.1.1 Either the "Staggered PM-lO" method or the "PM-lO Sampling Over Short Sampling Times" method, both ofwhich are based on the reference method for PM-1O
...4.1.2 Any other method for measuring PM-lO: 4.1.2.1 Which has a measurementrange orranges appropriate to accurately measure air

### pollution episode concentration ofPM-lO, 4.1.2.2 Which has a sample period appropriate for shortterm PM-lO measurements, and 4.1.2.3 For which a quantitative relationship to a reference or equivalent method for PM-10 has been established at the use site." U.S. Environmental Protection Agency. Code ofFederaLRegulations. 

### Title 40, Chapter I, Subchapter C, Part 58, Appendix C. "Ambient Air Quality Monitoring Methodology." 4.0 Particulate Matter Episode Monitoring. July 1, 1992. 4. U.S. Environmental Protection Agency. GuidelineforPM-10 Episode Monitoring Methods. 

### EPA-450/4-83-Q05, February 1985. 5. "3.3.3 Episode Monitoring
...Briefiy, two methods based on the filtration principle are recommended: staggered PM-lO sampling and short-term interval sampling. The staggered sampling procedure uses a 24-hour sampling procedure followed by a 2-hour post-sampling filter equilibration period. The short-term interval sampling method requires a 4-hour sampling period followed by a 2-hour filter equilibration period. In addition to these two procedures, other methods may be used provided the user demonstrates a site-specific correlation ofthe alternative method with the reference method." U.S. Environmental Protection Agency. PM-10 SIP Development Guideline. 

### EPA-450/2-86-001. June 1987.

5-23 April 19935.7 

### AMBIENT AIR QUALITYDATA REPORTING

5.7.1 

### General States are required to submit an annualreport ofall the ambient air quality monitoring data from their SLAMS networks (40 CFRPart 58.26). These annual summaries must contain, as a minimum, the following:l
• The annual arithmetic mean (Jlg/m3) as specified in Appendix K ofPart 50
• All daily PM-lO values above the level ofthe 24-hourNAAQS and dates of occurrence
• The sampling schedule, used such as once every six days, once every three days, etc.
• The number ofadditional sampling days beyond the sampling schedule used
• The number of24-hour average concentrations in the ranges as specified in section 2.7 ofAppendix F
• Thelocation, date, pollution source, and duration during which ambientlevels ofa pollutantreached orexceeded the level ofPM-lO specified by 40 CFR Part 51.16(a) as a level which could cause significant harm to the health ofthe generalpublic • A certification ofaccuracy by the State's senior airpollution control officer or his designee Part 58.26 requires that the annual report be submitted by July 1 ofeach year for data collected from January 1to December 31 ofthe previous year. fu addition, the States are required to submit, upon Regional Administrator request, all orpartofSLAMS data.2 As a subset ofthe SLAMS network, NAMS data are required, under Part 58.35, to be reported quarterly and within 120 days ofthe end ofa quarter.3
In addition to the annual SLAMS reporting requirements, section 4.0 ofAppendix A of40 CFRPart 58 requires that the results ofall validprecision and accuracy tests be reported to AIRS via the appropriate EPA Regional Office within 120 calendar days after the end ofeach calendarquarter. The report should include the results ofall collocated measurements including those**fallin~** below the levels specified in section 5.3.1 ofAppendix A (e.g., 20 Jlg/m3 for PM-lO). Data from invalid tests, from tests performed during a period 5-24 April 1993

### oftime for which ambient dataimmediatelyprior or subsequentto the tests were invalidated for appropriate reasons, and from tests ofmethods or analyzers not approved for SLAMS network use under Appendix C ofPart 58, 

### should not be reported.4



### 5.7.2 AirPollution Index Appendix G of40 

### CPR Part 58 

### requires States to report a daily air

### quality index to the general public through some prominent means (e.g., 

### radio, television, newspaper) and in accordance with the procedures contained in Appendix G.5,6 

### This index provides the general public with an idea ofhow healthy the ambient air

### is on aparticular day. The air

### quality index is required to bereported for all 

### urban areas with populations exceeding 200,000 

### (based on the most current decennial U.S. Census ofPopulation Report).5



### 5.7.3 Exceptional Events High ambient values ofPM-lO may be flagged by the State due to exceptional events. According to 40 

### CFR Part 50, 

### Appendix K, an exceptional eventis an uncontrollable event caused by natural sources ofparticulate matter or an eventthat is not expected to recur at a given location.7 

### The use ofambient monitoring data which include exceptional events data could result in inappropriate estimates ofthe expected annual value as outlined in Appendix K ofPart 50.8 

### As such, EPA has provided criteria and procedures for flagging such exceptional events in the Guideline on the Identification and Use of AirQualityDataAffected byExceptional Events.9 

### However, because ofnew waiverprovisions in section 188(f) 

### ofthe amended Act, which, in effect modify aspects ofthe exceptional events guidelines, the reader should consult EPA headquarters at the address provided in Section 1.0 ofthis document before using the exceptional events guidelines. In general, EPA recognizes 17 exceptional events flags applicable to PM-lO. These flags are described in 

### the Exceptional Events 

### guideline document. States and local agencies are responsible for the**ide~ltification** 

### and documentation ofambient PM-lO air 

### quality data influenced by exceptional events. The State/local agency must also provide background information in support of such determinations and this information mustbe submitted to the appropriate EPA Regional Office for concurrence and must be made available for public
5-25 

### April 1993review. Decisions on how flagged data are used for a specificpurpose 

### (e.g., attainment designation/demonstration, control strategy, etc.) are made on a case-by-case basis.lO Appendix K ofPart 50 describes the procedure for.making the necessary adjustments for exceptional events and trends when estimating the number ofexceedances for a single year. Questions and answerspertaining to exceptional events are contained in

### Response to QuestionsRegardingPM-IO StateImplementation Plan (SIP) Development. ll
Other statutoryrequirements and EPA policy related to nonanthropogenic and/or uncontrollable PM-lO emissions include the section 188(f) waiverprovisions under which EPA may waive any requirement applicable to any serious area where EPA detennines that anthropogenic sources ofPM-lO do not contribute significantly to the violation ofthe PM-lO standard in the area. EPA may also waive a specific attainmentdate where the Agency determines that nonanthropogenic sources contribute significantly to the violation ofthe PM10 standard in the area. Otherrelated statutory requirements include the section 179B provisions relating to exemptions for States which submitplans that demonstrate attainment or maintenance ofthe PM-lO NAAQS, but for emissions emanating from outside the United States. These requirements are discussed in more detail in Section 9.2 ofthis guideline.

5-26 April 1993

### REFERENCES FORSECTION 5.7

1. U.S. Environmental Protection Agency. Code of FederalRegulations. Title 40, ChapterI, SubchapterC, Part 58.26, and AppendixF 2.7.1 and 2.7.2. July 1, 1990. 2. "The State shall submitall or a portion ofthe SLAMS data to the Regional Administrator uponhis request. U.S. Environmental Protection Agency. Code of FederalRegulations. Title 40. Part 58.28. "Regional Office SLAMS data Acquisition
." July 1, 1992. 3. "(b) The State shall reportquarterly to the Administrator (through the appropriate Regional Office) all ambient air quality data andinformation
...(c) The quarterly report must: (1) Bereceived by the National Aerometric Data Bank within 120 days ofthe end ofeach reporting period, after being submitted by the States to the Regional Offices for review; (2) Contain all data and information gathered during the reporting period." U.S
. Environmental Protection Agency. Code of FederalRegulations. Title 40, Chapter I, Subchapter C, Part 58.35. "NAMS Data Submittal
." July 1, 1992. 4. U.S. Environmental Protection Agency
. Code of FederalRegulations
. Title 40, Chapter I, Subchapter C, Part 58, Appendix A 4.1. July 1, 1991. 5. "(a) The State shallreport to the general public on a daily basis through prominent notice an air quality index in accordance with the requirements ofAppendix G to this part. (b) Reporting must commence...for all urban areas with a population exceeding 200,000. (c) Thepopulation ofan urban area for purposes ofindex reporting is the mostrecent U
.S. censuspopUlation figure asdefined in 58.1 ofparagraph (s)." U.S. Environmental Protection Agency. Code ofFederalRegulations. Title 40, Chapter I, Subchapter C, Part 58.40. July 1, 1991. 6. "Prominentpublic notification consists ofat a minimum: (1) Furnishing the daily report to one or more ofthe appropriate news media (radio, television, newspapers); and (2) making the daily index reportpublicly available at one or more places of public access. Indexreports may also be disseminated by means ofrecorded messages" U
.S. Environmental Protection Agency. Code ofFederalRegulations. Title40, Chapter I, Subchapter C, Part 58, Appendix G 6. July 1, 1991. 7. "An exceptional event is an uncontrollable event caused by natural sources of particulate matter or an event that is not expected to recur at a given location." U.S. Environmental Protection Agency. Code ofFederalRegulations. Title 40, Chapter I, Subchapter C, Part 50, Appendix K 2.4. July 1, 1991. 8
. "Inclusion of such a value in the computation ofexceedances or averages couldresult in inappropriate estimates oftheir respective expected annual values." U.S.
5-27 April 1993Environmental Protection Agency. Code ofFederalRegulations. Title 40, ChapterI, Subchapter C, Part 50, Appendix K 2.4. July 1, 1991. 9. U.S. Environmental Protection Agency. Guideline on theIdentification and Use of Air QualityDataAffectedbyExceptional Events. EPA-450/4-86-007. July 1986. 10. "Underthis system, the State and local agency isresponsible for identifying and documenting data influenced by exceptional events. Background information in support ofthis detennination mustthen be submitted to the appropriate EPA Regional Officefor concurrence and must also be available for public review. Decisions on how flagged data are used for a specific purpose (attainmentdesignation, control strategy, etc.) are made on a case-by-case basis." U.S. Environmental Protection Agency. Guidancefor Completing the USEPA PM-10 ExceedanceReport (draft). Office ofAir Quality Planning and Standards. Research Triangle Park, N.C. May 1991. Section 5.0. 11. U.S. Environmental Protection Agency. Responses to QuestionsRegarding PM-10 StateImplementation Plan (SIP) Development. Office ofAir Quality Planning and Standards, Research Triangle Park, N.C. June 1988.

5-28 April 1993

### 6.0 AIR QUALITY MODELING 6.1 GENERAL Air quality modeling analyses are perfonned to demonstrate that aproposedcontrol strategy provides for attainment and maintenance ofthe NAAQS (40 CFR 51.112a) and protection ofthe PSD increments (40 CFR 51.1661). SIP submittals must include a description ofhow the modeling analysis was conducted by providinginfonnation on the models used; thejustification ofmodel selection; the modes ofmodels used; assumptions involved in model application; the meteorological data; ambient monitoring data used; the justification ofoff-site data, ifused; the model input data; and the model output data. 1


### In certain cases, a modifieddemonstration may be used in place ofa full SIP demonstration, as required in current guidance for the initial moderate PM-lO nonattainment areas, (i.e., 

### those areas, by operation oflaw, designated nonattainment upon enactment ofthe Clean Air Act Amendments of 1990 and classified as moderate upon enactme' nt). Forthose areas, EPA stated that modified demonstrations may be made in those situations where time constraints, inadequate resources, inadequate data bases, lack ofa model for some unique situations, and other unavoidable circumstances leave an area unable to submit an attainment demonstration within the short timeframe provided by the 1990 amendments (i.e., 

### by November 15, 1991). With regard to modeling requirements, all modified demonstrations should be accompanied by documentation ofthe modified modeling method, rationale for the modified demonstration, andjustification ofthe modified demonstration.2 

### Demonstrations based on this policy will be considered on acase-by-case basis.3



### 6-1 April 1993

### REFERENCES FOR SECTION 6.1

1. "(e) Modeling infonnationrequired to support the proposedrevision, including input data, outputdata, models used,justification ofmodel selections, ambientmonitoring data used, meteorological data used,justification for use ofoffsite data (where used), modes ofmodels used, assumptions, and other infonnation relevant to the detennination ofadequacy ofthe modeling analysis." Appendix V. 

### "Criteria for Determining the Completeness ofPlan Submissions." 54Federal Register 2,138-41 (January 19, 1989), State Implementation Plan Completeness Review. 2. "Generally, all SIP submittals for the initial moderate PM-lO nonattainment areas should follow the existing guidance on PM-10 modeling as noted above. In

### the situation where an area has completed or can complete its demonstration by November 15, 1991 consistent with existing guidance, an attainment demonstration based on the existing guidance should be submitted. However, in those situations where time constraints, inadequate resources, inadequate data bases, lack ofa model for some unique situations, and other unavoidable circumstances would leave an area unable to submit an attainment demonstration within the short timeframe provided by the newly revised law, then a modified demonstration based on the policy statement may be submitted. Section 189(a)(1)(B) ofthe recentlyrevised Clean Air Actrequires that all modified demonstrations be based on some form of 'air

### quality modeling.' In addition, 40 CFR §51.1l2requires that a demonstration be shown to be 'adequate and appropriate.' This supplemental policy is issued in accordance with these statutory and regulatory requirements. All such modified demonstrations should be accompanied by the following: 1. Documentation ofModified Modeling Method. Documentation ofthe procedures or analyses used in lieu ofthose set forth in the previously issued guidance. 2. Rationale for Modified Demonstration. An explanation ofwhy the alternative modeling techniques set forth in the guidance were not used. 3. Justification ofModified Demonstration. A description ofhow and why the SIP provides an adequate and appropriate demonstration ofareawide attainment." Memorandum. Calcagni, John, Director, Air Quality Management Division, Research Triangle Park, N.C., and Laxton, WIlliam G., Director, Technical Support Division, U 

### .S. EPA, Research Triangle Park, N.C., to Director, Air

### Pesticides and Toxics Management Division, Regions I, IV, VI; Director, Air and Waste Management Division, Region II;'

### Director, Air Management Division, Regions ill 

### and IX; Director, Air and Radiation Division, Region V; Director, Air and Toxics Division, Regions VII,

6-2 

### April 1993VIII, X. PM-lO SIP Attainment Demonstration Policy for Initial Moderate Nonattainment Areas. March 4, 1991. 3. "Demonstrations based on this policy will be considered on a case-by-case basis. The policy applies only to those initial moderate PM-I0 nonattainment areas which have completed the technical analysis for their SIP submittal andhave made a good-faith effort to submit a final SIP by their November 15, 1991 due date." Memorandum. Calcagni, John, Director, Air Quality Management Division, U.S. EPA, Research Triangle Park, N.C., and Laxton, William G., Director, Technical Support Division, U.S. EPA, Research Triangle Park, N.C., to Director, AirPesticides and Toxics Management Division, Regions I, IV, VI; Director, Air andWaste Management Division, Region II; Director, AirManagement Division, Regions III and IX; Director, Air and Radiation Division, Region V; Director, Air and Toxics Division, Regions Vil, VIII, X. PM-lO SIPAttainment Demonstration Policy for InitialModerate Nonattainment Areas. March 4, 1991.

6-3 April 1993

### 6.2 GUIDANCE ON AIR QUALITY MODELS Air quality dispersion modeling techniques appropriate for use in SIP, New Source Review (NSR), and PSD analyses are specifiedin the Guideline OnAirQualityModels (Revised) and SupplementA (Guideline).l.2 The Guideline is a primary source ofinformation on the proper selection and regulatory application ofdispersion models. Announcements of proposed and final revisions to the Guideline are made

### in the Federal Register as needed. Refined dispersion models are generallyrecommended for PM-lO regulatory application; however, modeling demonstrations may, 

### in some instances, includereceptor modeling, and combined dispersion and receptor modeling.3 Guidance on when and how these various techniques may be applied is provided in the PM-IO SIP Development Guideline.4 Guidance for model reconciliation,5 and an example model application,6 are available to assist in PM-lO modeling analyses and control strategy development. The ReceptorModel Technical Series (Volumes I

- VIP provides substantial additional guidance on the theory and application ofreceptor-oriented techniques. Clarifications and interpretations ofmodeling procedures become official EPA guidance through several courses ofaction: (1) the procedures are published as regulations or guidelines; (2) the procedures are formally transmitted as guidance to Regional Office managers; (3) the procedures are formally transmitted as guidance to Regional Modeling Contacts as a result ofa Regional consensus on technical issues; or (4) the procedures are a result ofdecisions by the Model Clearinghouse that effectively establish a national precedent.8 The Model Clearinghouse is the single EPA focal pointfor the review ofcriteriapollutant modeling techniques for specific regulatory applications.9 The Clearinghouse serves a major role in promoting fairness and consistency in modeling decisions that deviate from the established modeling guidance.lo Model Clearinghouse memoranda involving significant decisions with respect to interpretation ofmodeling guidance are available on the Support Center for Regulatory Air Models Electronic Bulletin Board. ll
The time at which changes in modeling guidance affect modeling analyses in progress will depend on the type of agreement under which those analyses are being conducted.l2 Normally, ongoing analyses will be grandfathered ifthere is a written protocol with a.legal or regulatory basis or ifthe analysis is complete and regulatory action is imminent or underway.13
6-4 April 1993 

## "REFERENCES FOR SECTION 6.2

1. "This guideline recommends air quality modeling techniques that should be applied to State ImplementationPlan (SIP) revisions for existing sources and to new source reviews, including prevention of significant deterioration (PSD)." U.S. Environmental Protection Agency. Guideline OnAir QualityModels (Revised), Office ofAir Quality Planning and Standards, Research Triangle Park, NC. EPA-450/2-78-027R. July 1986. p. 1-1. 2. U.S. Environmental Protection Agency. SupplementA to the Guideline OnAir Quality Models (Revised). Office ofAir Quality Planning and Standards, Research Triangle Park, NC. EPA-450/2-78-027R. July 1987. 3. U.S. Environmental Protection Agency. Guideline OnAir QualityModels (Revised), Office ofAir Quality Planning and Standards, Research Triangle Park, NC. EPA450/2-78-027R. July 1986. p.7-4. 4
. U.S. Environmental Protection Agency. PM-10 SIP DevelopmentGuideline, Office of Air Quality Planning and Standards, Research Triangle Park, NC. EPA-450/2-86-001. June 1987. pp. 4-1 through 4-14. 5. U.S. Environmental Protection Agency. ProtocolforReconcilingDifferencesAmong Receptor andDispersionsModels. EPA-450/4-87-008, 1987. 6. U.S. Environmental Protection Agency. Example Modeling to ILLustrate SIP Developmentfor the PM-10NAAQS. EPA-450/4-87-012, 1987
. 7. U.S. Environmental Protection Agency. Receptor Model Technical Series (Vols. I - VI).
• Volume I: Overview of ReceptorModelApplication to Particulate Source Apportionment, Office ofAir Quality Planning and Standards, Research Triangle Park, NC. EPA-450/4-81-016a. July 1981. • Volume II: ChemicalMass Balance, Office ofAir Quality Planning and Standards, Research Triangle Park, NC. EPA-450/4-81-016b. July 1981. • Volume III (1989Revision): CMB7 User's Manual, Office ofAir Quality Planning and Standards, Research Triangle Park, NC. EPA-450/4-90-004. January 1990. • Volume IV: Summary ofParticleIdentification Techniques. Office ofAir Quality Planning and Standards, Research Triangle Park, NC. EPA-450/4-83- 018. June 1983. • Volume V: SourceApportionmentTechniques and Considerationsfor Combining Their Use, Office ofAir Quality Planning and Standards, Research Triangle Park, 

### NC. EPA-450/4-84-020. July 1984.
6-5 April 1993

### • Volume VI: A Guide to the Use of FactorAnalysis andMultipleRegression (FAIMR) Techniques in SourceApportionment, Office of

### Air Quality Planning and Standards, Research Triangle Park, NC. EPA-450/4-85-007. June 1985. 8. "Changes in EPA modeling procedures become official Agency guidance when: (1) 

### they are published as regulations or guidelines, (2) they are formally transmitted as guidance to Regional Office managers, (3) they are formally transmitted as guidance to Regional Modeling Contacts as theresult ofa Regional consensus on technical issues, or (4) they are a result ofdecisions by the Model Clearinghouse that effectively set a national precedent" Attachment 2 ofmemorandum from Tlkvart, J.A., OAQPS, U.S. EPA, to Regional Modeling Contacts. January 2, 1985. (PN 110-85-01-02-070). 9. "The Model Clearinghouse is the single EPA focal pointfor reviewing the use of modeling techniques for criteria pollutants in specific regulatory applications." Memorandumfrom Tikvart, J.A., OAQPS, U.S. EPA, to Regional Chiefs, Air

### Branch Region VIT, Technical Support Branch Region I, Air and Radiation Branch Region V, Air Programs Branch Regions IT, III, IV, VI,

## vrn, IX, X. June 7, 1988. 10. "However, there is also aneed to provide for a mechanism thatpromotes fairness and consistency in modeling decisions among the various Regional Offices and the States." Memorandum from Tikvart, J.A., OAQPS, U.S. EPA, to Regional Chiefs, Air Branch Region VIT, Technical Support Branch Region I, 

### Air and Radiation Branch Region V, Air Programs Branch Regions IT, 

## m, IV, VI,

## vm, IX, X. June 7, 1988. 11. The Support Center for Regulatory Air Models (SCRAM) Electronic Bulletin Board, Office ofAir Quality Planning and Standards, Research Triangle Park, NC 27711. 12. "(T)he time at which changes in modeling guidance affect on-going modeling analyses is a function ofthe type ofagreement under which those analyses are being conducted." Attachment 2 ofmemorandum from Tikvart, lA., OAQPS, U.S. EPA, to Regional Modeling Contacts. January 2, 1985. (PN 110-85-01-02-070). 13. "On-going analyses should normally be 'grandfathered' if (1) there is a written protocol with a legal or regulatory basis (such as the Lovett Power Plant) or (2) the analysis is complete and regulatory action is imminent or underway." Attachment 2 of memorandum from Tlkvart, J.A., OAQPS, U.S. EPA, to Regional Modeling Contacts. January 2, 1985. (pN 110-85-01-02-070).

6-6 April 1993 

## !-

### 6.3 MODEL SELECTION Models selected to provide estimates ofambient concentrations ofPM-lO must be consistent with therequirements and guidelines specified in the Guideline onAirQuality Models (Revised).l
Two levels ofmodel sophistication exist: screening and refined. Screening techniques are used initially to eliminate more extensive modeling ifit is clearly established, through their application, that the proposed source or control strategy 

### will not cause or contribute to ambient concentrations in excess ofeither the NAAQS or the allowable PSD increments.2 Refined air quality models require more detailed and precise input data and consequently provide more accurate estimates of source impact. These refined models are used ifa screening technique indicates that a concentration resulting from the source may cause or contribute to'an exceedance ofthe PSD increment or the NAAQS.3 The refined model selected should be the one which most accurately represents atmospheric transport, dispersion, and chemical transformations in the areaunder analysis.4 Models have been developed for both simple and complex terrain situations; some are designed for urban applications while others are designed for rural applications. In simple terrain, RAM is recommended for urban sources. CRSTER and MPTER are recommended, respectively for single and multiple sources (without downwash) in rural areas. ISCST is recommended for complex industrial sources (with or withoutdownwash) in urban or rural areas. Separaterecommendations are provided for areas with intermediate or complex terrain. No model recommended for general use at this time accounts for secondary particulate formation or other transformations in a manner suitable for SIP control strategy demonstrations.5
The use ofreceptor models in conjunction with dispersion models can help to more precisely characterize specific source contributions. Where possible, the use ofcombined dispersion and receptor modeling is encouraged.6 The chemical mass balance (CMB) model is considered to be the most advanced ofthe available receptor models and its use is the most acceptablefor attainment demonstration purposes. Otherreceptor-oriented techniques include factor analysis, and optical and scanning electron microscopy.7

6-7 April 1993Undercertain conditions, there may be no recommended dispersion model, or the recommended model may not be applicable. Forexample, ifarea sources are the dominant contributors to ambientPM-lO concentrations, an attainmentdemonstration mightbe based on rollback ofthe apportionment derived from two reconciled receptor models. In such instances, the modeling approach mustbe approved by the appropriate Regional Office on a case-by-case basis.8•9 Procedures for objectively evaluating alternative modeling techniques are discussed in the EPA documents,Interim ProceduresforEvaluatingAirQualityModels (Revised) andInterim Proceduresfor EvaluatingAirQualityModels: Experience with Implementation.1o,ll

6-8 April 1993

### REFERENCESFORSECTION 6.3

1. "(1) All estimates ofambientconcentrationsrequired under this paragraph shall be based on the applicable air quality models, data bases, and otherrequirements specified in the 'Guideline on Air Quality Models (Revised), (1986) which is incorporated by reference." 51 Federal Register 32,178 (September 9, 1986); Requirements for Preparation Adoption and Submittal ofImplementation Plans. 2. "The purpose ofsuch techniques is to eliminate the need offurther more detailed modeling for those sources that clearly will not cause or contribute to ambient concentrations in excess ofeither the National Ambient Air Quality Standards or the allowableprevention ofsignificant deterioration concentration increments." U.S. Environmental Protection Agency. 

### Guideline OnAir QualityModels (Revised). Office ofAir Quality Planning and Standards, Research Triangle Park, NC. EPA450/2-78-027R. July 1986
. p. 2-6. 3. "Ifa screening technique indicates that the concentration contributed by the source exceeds the PSD increment or the incrementremaining tojustmeet the NAAQS, then the second level ofmore sophisticated models should be applied." U.S. Environmental Protection Agency. 

### Guideline OnAir QualityModels (Revised). Office ofAir Quality Planning and Standards, Research Triangle**~ark,** NC. EPA-450/2-78-027R. July 1986. p. 2-6. 4. "In all cases, the model applied to a given situation should be the one that provides the most accurate representation ofatmospheric transport, dispersion, and chemical transformations in the area ofinterest." U.S. Environmental Protection Agency. 

### Guideline OnAir Quality Models (Revised). Office ofAir Quality Planning and Standards, Research Triangle Park, NC. EPA-450/2-78-027R. July 1986. p. 1-3. 5. "For urban-wide refined analyses CDM 2.0 or RAM should be used. CRSTER and MPTER are recommended for point sources ofsmall particles. For source-specific analyses ofcomplicated sources, the ISC model is preferred
. No model recommended for general use at this time accounts for secondaryparticulate formation or other transformations in a manner suitable for SIP control strategy demonstrations." U.S. Environmental Protection Agency. 

### Guideline OnAir Quality Models (Revised). Office ofAir QUality Planning and Standards, Research Triangle Park, NC. EPA450/2-78-027R. July 1986. p. 7-4

6-9 April 1993

### 6. "Wherepossible, the use ofreceptor models in conjunction with dispersion models is encouraged to more precisely characterize the emissions inventory and to validate source-specific impacts calculated by the dispersion model." U.S. Environmental Protection Agency. Guideline OnAir QualityModels (Revised). 

### Office ofAir 

### QualityPlanning and Standards, Research Triangle Park, NC. EPA-450/2-78-027R. July 1986. p. 7-4 7. "Onekey, overriding selection consideration is that CMB is considered the most advanced ofthe receptor models
...The other methods include factor analysis'(FA), automatic scanning electron microscopy (ASEM), and microscopy (OM)." U.S. EnvironmentalProtection Agency. PM-10 SIP Development Guideline, 

### Office ofAir 

### Quality Planning and Standards, Research Triangle Park, NC. EPA-450/2-86-001. 

### June 1987. pp. 4-1 through 4-14, 8, "For those cases where no recommended technique is available or applicable, modeling approaches should be approved by the appropriate Regional Offices on a case-by-case basis," U.S. Environmental Protection Agency. Guideline OnAir QualityModels (Revised). 

### Office ofAir Quality Planning and Standards, Research Triangle Park, NC. EPA-450/2-78-027R. July 1986. p. 7-4 9. "
...This approach is an option provided for in sections 4 and 5 ofthe PM-i0 SIP Development Guideline. 

### While itis clear from the guideline that use ofdispersion models in combination with receptor models is the preferred approach, in certain limited situations, the use ofan RM demonstration alone may be adequate to demonstrate attainment The State must obtain approval to use the RM demonstration priorto SIP submittal. The decision that an RM demonstration is adequate to demonstrate attainmentis the responsibility ofthe Regional Office; however, the Region should consult the Model Clearinghouse for advice in making this determination." Memorandum. Bauman, Robert D. Chief, SOJParticulateMatter Programs Branch, U.S. EPA, Research Triangle Park, NC, and Joseph A. Tikvart, Chief, Source Receptor Analysis Branch, U.S. EPA, Research Triangle Park, NC, to Chief, Air Branch, Regions I-X. PM-lO SIP Demonstration for Small Isolated Areas with Spatially Uniform Emissions. July 5, 1990. (PN-llO-90-07-05-106). p. 1. 

### 10. U.S. Environmental Protection Agency. Interim Proceduresfor Evaluating Air Quality Models (Revised). 

### Office ofAir Quality Planning and Standards, Research Triangle Park, NC. EPA-450/4-84-023. September 1984.
. 11. U.S. Environmental Protection Agency. Interim Proceduresfor EvaluatingAir Quality Models: Experience with implementation. 

### Office ofAir Quality Planning and Standards. Research Triangle Park, NC. EPA-450/4-85-006. July 1985.

6-10 April 1993

### 6.4 METEOROLOGICAL INPUT Meteorologicaldataused in air quality modeling should be spatially and climatologically (temporally) representative ofthe area ofinterest.l Use ofsite-specific data is preferred for air quality analyses provided that one year ormore ofquality-assured data are available.2 Suggestions for the collection and use ofon-site data are provided in the Guideline and in the EPA documents, 

### On-Site Meteorological Program Guidancefor RegulatoryModelingApplications,AmbientMonitoring GuidelinesforPrevention of SignificantDeterioration (PSD) and 

### QualityAssuranceHandbook/orAirPollution MeasurementSystems: Volume IV. Meteorological Measurements. 3•s Ifone year ofsite-specific data is not available, five years ofotherrepresentative meteorological data (ordinarily obtained from the nearest National Weather Service (NWS) station) may be used in the modeling analysis. These five years should be the mostrecent, readily available consecutive five years ofdata.6 The five year period is defined to ensure that the model results adequately represent meteorological conditions conducive to the prediction ofmaximum ambient concentrations. Potential sources ofrepresentative meteorological data include the National Weather Service, local universities, the Federal Aviation Administration, military stations, and air quality agencies. Meteorological data collected by the National Weather Service may be obtained from the Support Center for Regulatory Air Models Electronic Bulletin Board.7
When modeling previously permitted sources whose emission limitations are based on a specific year ofmeteorological data, that year ofdata should be added to any longerperiod involved in the modeling analysis.8
Gaussian models do not address calm wind conditions. Ambient concentrations predicted by such models during calm conditions should not be considered valid.9 Proper procedures for calculating average concentrations during calm wind conditions are provided in the Guideline. Some air quality models recommendedin the Guideline include algorithms to identify periods ofcalm so that they may be dealtwith separately. As mentioned earlier, meteorological data collected on-site must be quality-assured prior to their application in air quality modeling analyses. At sites with collocated, continuous air quality monitors, the inspection, maintenance and calibration ofeach
6-11 April 1993meteorological instrument operated must be conducted to guarantee a minimum of90 percent dataretrieval (80 percentforremote sites).lo Atthe initiation ofthe monitoring program, and at least every six months thereafter, routine system calibrations and audits should be performed.11 Meteorological audits, performed independently ofthe organizationresponsible for data collection and system maintenance, should be scheduled on a semiannual basis.ll Aside from providing for on-site calibration ofinstruments, these independent evaluations should address network installation; inspection, maintenance and calibration procedures; data reduction procedures; and data logging and tabulation procedures.12
As recommended in the 

### QualityAssuranceHandbook, meteorological data validation can be conducted using a three-fold approach ofinitial hardcopy audit ofthe data followed by screening the data through a program designed to note and flag questionable values and finally passing the data through a comparisonprogram which evaluates how well the data fit the synoptic conditionsprevalentin the area ofon-site measurement.

6-12 April 1993

### REFERENCES FORSECTION 6.4

1. "The meteorological data used as inputto a dispersion model should be selected on the basis ofspatial and climatological (temporal) representativeness as well as the ability ofthe individual parameters selected to characterize the transport and dispersion conditions in the area ofconcern." U.S. EnvironmentalProtection Agency. Guideline OnAir QualityModels (Revised). Office ofAir QUality Planning and Standards, Research Triangle Park, NC. EPA-450/2-78-027R. July 1986. p. 9-10. 2. "Ifone year or more, up to five years, ofsite-specific datais available, these data are preferred for use in air quality analyses." U.S. Environmental Protection Agency. Guideline OnAir QualityModels (Revised). Office ofAir Quality Planning and Standards, Research Triangle Park, NC. EPA-450/2-78-027R. July 1986. p. 9-12. 3. U.S. Environmental Protection Agency. On-SiteMeteorologicalProgram Guidance forRegulatoryModeling Applications. Office ofAir Quality Planning and Standards, Research Triangle Park, NC. EPA-450/4-87-013. June 1987. 4. U.S. Environmental Protection Agency. AmbientMonitoring Guidelinesfor Prevention ofSignificantDeterioration (PSD). Office ofAir Quality Planning and Standards, Research Triangle Park, NC. EPA-450/4-87-007. May 1987. 5. U.S. Environmental Protection Agency. QualityAssuranceHandbookforAir PollutionMeasurementSystems: Volume 

### Iv. MeteorologicalMeasurements. Atmospheric Research and Exposure Assessment Laboratory, Research Triangle Park, NC. ·Office ofResearch and Development, EPA-600/4-90-003. September 1989. 6. "Five years ofrepresentative meteorological data should be used when estimating concentrations with an air quality modeL Consecutive years from the mostrecent, readily available 5-yearperiod are preferred." U.S. Environmental Protection Agency. Guideline OnAir Quality Models (Revised). Office ofAir Quality Planning and Standards, Research Triangle Park, NC. EPA-450/2-78-027R. July 1986. p. 9-12. 7. The Support Center for Regulatory AirModels (SCRAM) Electronic Bulletin Board, Office ofAir Quality Planning and Standards, Research Triangle Park, NC 27711. 8. "For permitted sources whose emission limitations are based on a specific year of meteorological data that year should be added to any longer period being used (e.g., 5 years ofNWS data) when modeling the facility at a later time." U.S. Environmental Protection Agency. Guideline OnAir QualityModels (Revised). Office ofAir Quality Planning and Standards, Research Triangle Park, NC. EPA-450/2-78-027R. July 1986. p. 9-12.
6-13 April 1993

### 9. "Hourly concentrations calculated with Gaussian models using calms should not be considered valid; the wind and concentration estimates for these hours should be disregarded and considered to be missing." U.S. Environmental Protection Agency. Guideline OnAirQualityModels (Revised). 

### Office ofAir 

### Quality Planning and Standards, Research Triangle Park, NC. EPA-450/2-78-027R. July 1986. p. 9-24. 10. "Inspection, servicing, and calibration ofequipment must be scheduled throughout the measurementprogram at appropriate intervals to assure atleast 90 percent data retrieval for each variable measured at sites where continuous air

### qUality monitors are being operated. Atremote sites, dataretrieval for measured variables should not fall below 80 percent." U.S. Environmental Protection Agency. AmbientMonitoring GuidelinesforPrevention ofSignificantDeterioration (PSD). 

### Office ofAir Quality Planning and Standards, Research Triangle Park, NC. EPA-450/4-87-007. May 1987. p.55. 11. "Routine system calibrations and system audits should be performed at the initiation of a monitoring program and at least every six months thereafter. More frequent calibrations and audits may be needed in 

### the early stages ofthe program ifproblems are encountered, or if

### valid data retrieval rates are unacceptably low." U.S. Environmental Protection Agency. On-Site Meteorological Program Guidancefor RegulatoryModeling Applications. 

### Office ofAir Quality Planning and Standards, Research Triangle Park, NC. EPA-450/4-87-013. June 1987. p. 8-38. 12. "An independent meteorological audit (by other than one who conducts the routine calibration and operation ofthe network) should be performed to provide an on-site calibration ofinstruments as well as an evaluation of(a) the network installation, (b) inspection, maintenance, and calibration procedures, and logging thereof, (c) data reduction procedures, including spot checking ofdata, and (d) data logging and tabulation procedures. [S]uch independent meteorological audit-evaluations should be performed about each 6 months." U.S. Environmental Protection Agency. Ambient Monitoring GuidelinesforPrevention ofSignificantDeterioration (PSD). 

### Office of Air Quality Planning and Standards, Research Triangle Park, NC. EPA-450/4-87-007. May 1987. p.55.

6-14 April "1993

### 6.5 SOURCEINPUT 6.5.1 General Emission input data to be used to evaluate SIP's and PSD analyses for compliance with the annual and short-term ambient standards are described in Table 9-1 ofthe Guideline OnAirQualityModels (Revised).i The model input datarequirements in this table apply to stationary point source control strategies.2 Othermodel inputcriteria may apply with regard to emissions trading or NSR. Determination ofemissionlimits for these purposes is discussed in section 9 ofthis document.



### 6.5.2 Allowable Versus Actual Emissions PM-lO concentrations estimated from stationary point sources undergoing a SIP emission limitreview must reflect the maximum allowable emission limit or federally enforceable permitlimit ofthe source.3 A source's total emissions reflected in modeling analyses are determined as the product ofthe source's emission limit, operating level, and operating factor. The operating level used must be the actual or design capacity (whichever is greater) or the federally enforceable permitcondition. Operating levels less than 100 percent ofcapacity should also be modeled for those cases in which the source operates at a capacity substantially less than design and in which changes in stackparameters associated with the operating conditions couldresultin higher ground level concentrations.4 In the case oflarge powerplants, for example, loads such as 50 and 75 percent ofcapacity should also be modeled. Ifa source operates at greater than 100 percent load for periods during nonnal operation that couldresultin violations ofthe NAAQS or PSD increments, this load should be modeled. The operating factor (e.g., hours/year or hours/day) for annual averages should be the actual operating factor averaged over the mostrecent two years (unless itis determined that this period is notrepresentative). For short term (24-hour) averages, the operating factor should be based on continuous operation; however, 

### ifoperation is not continuous, and is constrained by a federally enforceablepermit condition, an appropriate adjustment to the

6-15 April 1993modeled emission rate may be made (i.e., modeling for only those hours during which the sourceis operating).s Identical inputrequirements apply to sources defined as "nearby" background sources. Theterm "nearby" refers to those sources expected to cause a significant concentration gradient in the vicinity ofthe source or sourcesunder consideration.6 Ifother background sources are modeled, the maximum allowable emission limit or federally enforceablepermit limit should be used in estimating average concentrations. The operating level used for estimating concentrations from these sources should be the annual level when actually operating, averaged over the mostrecent two years (unless this period is deemed unrepresentative). The operating factors used for other background sources are identical to those indicated previously in this section.



### 6.5.3 Area Sources
To estimate PM-lO concentrations from area sources, emissions input data should generally be based on annual average conditions.7



### 6.5.4 Background Concentration Background concentrations are an essential element ofthe total air quality concentration to be considered in the determination ofsource impacts for 

### SIP'S.8 These concentrations may include contributions from natural sources, nearby sources other than those currently under consideration, and unidentified sources. Recommendations for determining background concentrations are provided in the Guideline.9
In the case ofisolated sources, air quality data monitored in the vicinity ofthe source(s) under consideration should beused to determine the background concentrationfor the averaging times ofconcern.to Concentrationsrecorded while the source in question is impacting the monitor should not be used in determining the background concentration. 11 Use ofmonitored air quality data is recommended for determining thatportion ofthe background attributable to sources other than those nearby (e.g., natural sources, minor sources, and distant major sources).t2 However, Tables 9-1 and 9-2 ofthe 

### Guideline onAir Quality
6-16 April 1993Models (Revised) may be used to determine background concentrations for modelling applications. Inmulti-source areas, nearby sources that are anticipated to cause a concentration gradient inthe vicinity ofthe source or sources under consideration for emission limit(s) should be explicitly modeled. 13•14 The impact ofnearby sources should be examined at those locations where interaction exists between the plume ofthe source under consideration and those ofthe nearby sources (including natural background).



### 6.5.5 Stack Height Inputto Air Quality Modeling Specification ofstack height is an important consideration in the development of source inputfor an air quality modeling analysis. Generally, the lesser ofthe actual stack height or good engineeringpractice (GEP) stack heightis used for airquality modeling (refer to Section 7.2 ofthis documentfor definition ofGEP). The following guidance on a number ofparticular modeling questions has been provided by EPA: 1S

• Ifthe actual stack height is greater than GEP height and where itis necessary to reduce stack height credit: Use existing stack gas exitparameters
-- temperature, flow rate and stack top diameter

-- and model the stack at GEP height.
• Ifthe actual stack height is less than GEPheight and dispersion techniques are employed: Two cases should be modeled in orderto establish an appropriate emission limitation for the situation in which it is desired to construct a source atless than GEP height and use dispersion techniques to make up the difference in plume rise. First conduct a modeling analysis using the GEP stack height without enhanced dispersion parameters. Secondly, conduct a modeling analysis using the less than GEP stack height with the increased plume rise. The more stringent emission limitation resulting from each ofthe two model runs should be the one specified as the enforceable limitation.
• Stack height input for point sources modeled for the purpose ofdemonstrating protection ofthe NAAQS or PSD increments:

6-17 April 1993The lesser ofactual or GEP stack height should be used as input.
• Stack height for background sources: The lesser ofactual or GEP stack height should be used for each background source.
• Excluding the effects ofprohibited dispersion techniques for modeling purposes: Modeling to exclude the effects ofprohibited dispersion techniques on the emission limitations will be accomplished byusing the temperature and flow rates as the gas stream enters the stack, and recalculating stack parameters to exclude the use ofprohibited techniques.
• Ifsingle-flued, merged stacks ormultiflued stacks are involved in a modeling analysis refer to Section 7.7 ofthis guideline to determine ifthis merging is creditable.
• Ifplume merging from multiflued stacks is not allowed, then each flue/liner must be modeled as a separate source and the combinedimpactdetermined. For single fiued, merged stacks where creditis not allowed, each unit should be modeled as a separate stack located at the same point. The stack exit velocity and temperature would be the same as for the existing merged stack conditions and the volume flow rate based on an apportionment ofthe flow from the individual units.
6.5.6 Stack Downwash and BuildingWake Effects
Air quality modeling ofsources with stacks which are less than GEP should consider the impacts associated with building wake effects both for the source inquestion and for nearby sources. 16 In determining which background sources constitute "nearby" sources, the reviewing agency must exercisejudgement. Exercisingjudgementin these cases can minimize the resource burden associated with collecting building dimension data. 17

6-18 April 1993REFERENCES FOR SECTION 6.5

1. 

### U.S. Environmental Protection Agency. Guideline OnAir QualityModels (Revised), Office ofAir 

### QUality Planning and Standards, Research Triangle Park, NC. EPA450/2-78-027R. July 1986. p. 9-5. 2. "The EPA's policy for demonstrating stationarypoint source compliance with the NAAQS for SIPpurposes clearly requires the use ofemissions which are more closely tied to allowable emissions. The modelemission inputdatarequirements for such SIP demonstrations are contained in Table 9-1 ofthe 'Guideline for Air 

### Quality Models (Revised)'
..." Memorandum from Calcagni, J., and Laxton, W., OAQPS, U.S. EPA, to T.J. Maslany, Air

### Management Division, Region III, and W.B. Hathaway, Air 

### Pesticides, and Toxics Division Region VI. March 16, 1989. 3. U.S. Environmental Protection Agency. Guideline OnAirQuality Models (Revised), Office ofAir 

### Quality Planning and Standards, Research Triangle Park, NC. EPA450/2-78-027R. July 1986. Table 9-1 p. 9-5. 4. "Where a source operates at substantially less than design capacity, and the changes in the stackparameters associated with the operating conditions could lead to higher ground level concentrations, loads such as 50 percent and 75 percent ofcapacity should also be modeled." U.S. Environmental Protection Agency. Guideline OnAir QualityModels (Revised), Office ofAir Quality Planning and Standards, Research Triangle Park, NC. EPA-450/2-78-027R. July 1986. 5. U.S. Environmental Protection Agency. Guideline OnAirQuality Models (Revised), Office ofAir Quality Planning and Standards, Research Triangle Park, NC. EPA450/2-78-027R. July 1986. Table 9-1 p. 9-5. 6. "Nearby Sources: All sources expected to cause a significant concentration gradient in the vicinity ofthe source or sources under consideration for emission limit(s) should be explicitly modeled." U.S. Environmental Protection Agency. Guideline OnAir QualityModels (Revised), Office ofAir 

### Quality Planning and Standards, Research Triangle Park, NC. EPA-450/2-78-027R. July 1986. p. 9-8. 7. "Emissions from area sources should generally be based on annual average conditions." U.S. Environmental Protection Agency. Guideline OnAir Quality Models (Revised), Office ofAir Quality Planning and Standards, Research Triangle Park, NC. EPA-450/2-78-027R. July 1986. p. 9-4.

6-19 April 19938. "Background concentrations are an essential partofthe total air quality concentration to be considered in determining source impacts." U.S. Environmental Protection Agency. 

### Guideline OnAirQualityModels (Revised), Office ofAir Quality Planning and Standards, Research Triangle Park, NC. EPA-450/2-78-027R. July 1986. p. 9-7. 9. U.S. Environmental Protection Agency. 

### Guideline OnAirQualityModels (Revised), Office ofAir Quality Planning and Standards, Research Triangle Park, NC. EPA450/2-78-027R. July 1986. 10. "Use 

### air quality data collected in the vicinity ofthe source to determine the background concentration for the averaging times ofconcern." U.S. Environmental Protection Agency. 

### Guideline OnAirQualityModels (Revised), Office ofAir Quality Planning and Standards, Research Triangle Park, NC. EPA-450/2-78-027R. July 1986. p. 9-8. 11. "Determine the mean background concentration at each monitor by excluding values when the source in question is impacting the monitor." U.S. Environmental Protection Agency. 

### Guideline OnAir QualityModels (Revised), Office ofAir Quality Planning and Standards, Research Triangle Park, NC. EPA-450/2-78-027R. July 1986. p. 9-8. 12. "Other Sources: Thatportion ofthe background attributable to all other sources (e.g., natural sources, minor sources and distant major sources) should be determined either by the procedures found in section 9.2.2 or by application ofa model using Table 9- 1." U.S. Environmental Protection Agency. 

### Guideline OnAir Quality Models (Revised), Office ofAir Quality Planning and Standards, Research Triangle Park, NC. EPA-450/2-78-027R. July 1986. p. 9-9. 13. "Nearby Sources: All sources expected to cause a significant concentration gradientin the vicinity ofthe source or sources under consideration for emission limit(s) should be explicitly modeled." U.S. Environmental Protection Agency. 

### Guideline OnAir Quality Models (Revised), Office ofAir Quality Planning and Standards, Research Triangle Park, NC. EPA-450/2-78-027R. July 1986. p. 9-8. 

### 14. "Nearby sources which are expected to cause a significant concentration gradient in the vicinity ofthe source under consideration should be explicitly modeled (as 'background' sources)." Memorandumfrom Calcagni, J., OAQPS, U.S. EPA, to 

### W. Laxton, OAQPS. May 3, 1989. 15. Memorandum from Helms, G.T., OAQPS, U.S. EPA, to Air Branch Chief, Regions 

### 1- 

### X. October 10, 1985. (PN 123-85-10-10-007). 16. 

### "Ifstacks for new or existing major sources are found to be less than the height defined by EPA's refined fonnula [H

### + 1.5L] for determining GEP height, then 

### air quality impacts associated with cavity or wake effects due to the nearby building structures should be determined." U.S. Environmental Protection Agency. 

### Guideline
6-20 April.1993

### OnAirQualityModels (Revised), 

### Office ofAir 

### QUality Planning and Standards, Research Triangle Park, NC. EPA-450/2-78-027R. July 1986. p. 7-7. 17. "This guidance provides considerable flexibility and requiresjudgementto be exercised by the reviewing agency in

### identifying which background sources should be fully modeled. The burden ofcollecting building dimension data may be mitigated somewhatby application ofthisjudgement" Memorandumfrom Calcagni, J., OAQPS, U.S. EPA, to 

### W.B. Hathaway, Air Pesticides, andToxics Division, Region

### VI. March 31, 1989.

6-21 April 1993 1-

### 6.6 RECEYfOR ANALYSIS Defining the receptor network used for air quality analyses in support ofSIPrevisions should be made on a case-by-case basis, taking into consideration the topography, the climatology, existing monitor locations, andresults ofthe initial screeningprocedure.l Receptor sites for any analysis should be assignedin sufficientdetail to estimate the highest concentrations and predict any potentialviolations ofthe NAAQS or the PSD increment.2 A modeling analysis performed for the puxpose ofredesignating an area to attainment must follow the Guideline with respectto the scope ofthe receptor network and not necessarily address only the area to be redesignated.3

6-22 April 1993

### REFERENCES FOR SECTION 6.6 1. 

### "This selection ofreceptor sites should be a case-by-case detennination taking into considerationthe topography, the climatology, monitor sites, and the results ofthe initial screening procedure." U.S. Environmental Protection Agency. Guideline On AirQualityModels (Revised). 

### Office ofAir 

### Quality Planning and Standards, Research Triangle Park, NC. EPA-450/2-78-027R. July 1986. p.8-4. 2. "Receptor sites for refined modeling should be utilized in sufficient detail to estimate the highest concentrations and possible violations ofa NAAQS or a PSD increment." U.S. Environmental Protection Agency. Guideline OnAirQualityModels (Revised). 

### Office ofAir Quality Planning and Standards. Research Triangle Park, NC. EPA-45- O/2-78-027R. July 1986. p.8-4. 3. "If

### a modeling analysis is required for any reason, that analysis mustmeet the requirements ofthe Guideline." Memorandum from Bauman, R.D., OAQPS, U.S. EPA, to J. Tikvart, Office ofAir 

### QUality Planing and Standards. February 15, 1989.

6-23 April 1993 

## ...

### 6.7 OTHER MODEL REQUIREMENTS The 

### Guideline onAirQualityModels (Revised) provides discussion and guidance relative to a number ofspecial modeling considerationsfor PM-lO. Issues that may arise in modeling analyses ofPM-IO emissions are treatment ofstagnation, fumigation, long range transport, particle settling and deposition, complex terrain, and other situations where model appli9ations are limited.



### 6.7.1 Stagnation Stagnation events are characterized by periods ofcalm or very light winds and variable wind direction. Such conditions may persistfrom several hours.up to several days and may lead to high ground level concentrations. Treatment ofcalm wind conditions poses a special problem in model applications since Gaussian models assume thatconcentration is inverselyproportional to wmd speed. Thus concentrations become unrealisticalJy large when wind speeds are less than 1

### mlS.l Stagnationperiods should be addressed in the air quality modeling analysis; however, special precautions are warranted. The user should consult with the appropriate EPA Regional Office priorto modeling stagnation events for regulatory applications.2



### 6.7.2 Fumigation Fumigation occurs when aplume is emitted into a stable layer ofair that is subsequently mixed to ground level through convective transfer ofheat from the surface or through advection to less stable surroundings. Fumigation can cause high ground level concentrations and is an important consideration for sources located near bodies ofwater. There are no recommended refined techniques to model fumigation conditions; however, there are screening procedures that may be used to approximate expected concentrations. Results obtained from the screening procedures should be used with care.3• 4

6-24 April 1993

### 6.7.3 Long Range Transport Detennining the long range transport ofPM-lO emissions may be significant in the analysis ofsource impacts on PSD Class I areas.s Assistance with the appropriate techniques to utilize in these modeling situations should be obtained from the EPA Regional Office.



### 6.7.4 Settling and Deposition Gravitational settling and deposition may be included in the modeling analysis ifeither is a significantfactor. Given the small particle size, particle settling for PM-IO may be considered as negligible. Neglecting deposition is a conservative approach that is warranted for screening analyses.6 The Industrial Source Complex (ISC) model contains settling and deposition algorithms and isrecommended for use when the size distribution is quantified.7



### 6.7.5 Model Limitations While modeling is the preferred method , for determining emission limitations for both new and existing sources, there may be circumstances in which there is no applicable refined model. These include complex terrain situations, land water interface areas, secondary particulate formation, and urban locations where a large fraction ofparticulates originate from nontraditional sources. The Guideline provides criteria for detennining the acceptability of measured data to be used in these instances.8 Also, while generally not encouraged, model calibration oflong term (annual average) models may be acceptable in some situations as the best alternative for improving the accuracy ofthe predicted concentration.9

6-25 April 1993REFERENCES FOR SECTION 6.7

1. "Treatment ofcalm orlight and variable wind poses a special problem in model applications since Gaussian models assume that concentration is inverselyproportional to wind speed. Furthermore, concentrations become unrealistically large when wind speeds less than 1

### mls are input to the model." U.S. Environmental Protection Agency. Guideline OnAir QualityModels (Revised). Office ofAir QualityPlanning and Standards, Research Triangle Park, NC. EPA-4S0/2-78-027R. July 1986. p.9- 

### 23. 2. "When stagnation periods such as these are found to occur, they should be addressed in the airquality modeling analyses. WYND valley, listed in Appendix B, may be applied on a case-by-case basis for stagnation periods of24 hours orlonger in valleytype situations. Caution should be applied when applying the model to elevated point sources. Users should consult with the appropriate Regional Office prior to regulatory application ofWYND valley." U.S. Environmental Protection Agency. Guideline On Air Quality Models (Revised). Office ofAir Quality Planning and Standards, Research Triangle Park, NC. EPA-450/2-78-027R. July 1986. p. 8-12. (Draft Revised September 1990) 3. "There are no recommended techniques to model this phenomenon [fumigation]. There are, however, screening procedures (see Screening ProceduresforEstimating the Air Quality Impact ofStationary Sources) that may be used to approximate the concentrations. Considerable care should be exercised in using the results ofthe screening techniques." U.S. Environmental Protection Agency. Guideline OnAir QualityModels (Revised). Office ofAir Quality Planning and Standards, Research Triangle Park, NC. EPA-450/2-78-027R. July 1986. p. 8-11. 4. U.S. Environmental Protection Agency. Screening Proceduresfor Estimating theAir QualityImpact ofStationary Sources. Office ofAir Quality Planning and Standards, Research Triangle Park, NC. EPA-4S0/4-88-01O. August 1988. 5. "However, the useful distance to which most Gaussian models are considered accurate for setting emission limits is SO km. Sincein many cases Class I areas may be threatened at distances greater that SO km from new sources, some procedure is needed to (1) determine ifa significant impact will occur, and (2) identify the model to be used in setting an emission limit ifthe Class I increments are threatened
..." U.S. Environmental Protection Agency. Guideline OnAir Quality Models (Revised). Office of

### Air Quality Planning and Standards, Research Triangle Park, NC. EPA4S0/2-78-027R. ,July 1986. p. 7-8. 6. "For screening analyses, the conservative assumption ofnegligible removal is warranted, considering the size ofthe particles." U.S. Environmental Protection Agency. PM-JO SIP Development Guideline, Office ofAir Quality Planning and 6-26 April 1993Standards, Research Triangle Park, NC. EPA-450/2-86-001. June 1987. pp. 4-1 through 4-14. 7. "Gravitational settling and deposition may be directly included in a model ifeitheris a significantfactor. Atleastone preferred model (ISC) contains settling and deposition algorithms and is recommended for use whenparticulate matter sources can be quantified and settling and deposition are problems." U.S. Environmental Protection Agency. 

### Guideline OnAirQualityModels (Revised). Office ofAir QUality Planning and Standards, Research Triangle Park, NC. EPA-450/2-78-027R. July 1986. p. 8-9. 8. "Modeling is the preferred method for determining emission limitations for both new and existing sources . .. [T]here are circumstances where there is no applicable model, and measured data may need to be used. Examples ofsuch situations are: (1) complex terrain locations; (2) land/water interface areas; and (3) urban locations with a large fraction ofparticulate emissions from nontraditional sources." U.S. Environmental Protection Agency. 

### Guideline On Air QualityModels (Revised). Office ofAir Quality Planning and Standards, Research Triangle Park, NC. EPA450/2-78-027R. July 1986. p. 11-5. 9. "Calibration oflong tenn multi-source models has been a widely usedprocedure even though the limitations imposed by statistical theory on the reliability ofthe calibration process for long tenn estimates are well known.61 In some cases, where a more accurate model is not available, calibration may be the best alternative for improving the accuracy ofthe estimated concentrations needed for control strategy evaluations" U.S. Environmental Protection Agency. 

### Guideline onAirQuality Models (Revised). Office ofAir Quality Planning and Standards, Research Triangle Park, NC. EPA450/2-78-027R. July 1986. p. 8-13.

6-27 April 1993

### 6.8 RECEPTOR MODELING Volume I ofthe Receptor Model Technical Series describes eight categories of receptor models as follows: 

### ChemicalMass Balance This method matches sourceparticle size and chemical "fingerprints" to those measured atthe receptor to back-calculate the impact ofspecific sources or source classes of similar chemical composition. Given data on the ambient concentrations ofseveral chemical species and the percentby weight ofthese species in the emissions from the sources, a set of equations is prepared and solved to determine the source impacts. 

### EnrichmentFaCtors Ambient aerosol composition data are used in association with areference element (usually a crustal element such as Fe, Al or Si) to provide an estimate ofthe degree to which a specific ambient aerosol element has been "enriched" by an anthropogenic source. If

### the "enriched" element is known to be a unique tracer for a specific source, and the concentration ofthe tracerin the source emissions is known, a crude estimate ofthe source's impact can be made. 

### Microscopic Techniques Particle identification by optical microscopy was one ofthe first and the most widely used methods ofsource apportionment ofcoarse mode particles. Current technology has been expanded to include computer-driven scanning electron microscopy coupled with x-ray fluorescence analysis to provide a particle-by-particle analysis ofambient course particulate filters. As a consequence, particle identification methods traditionally founded on particle size shape, color, bifringence, and surface properties have been expanded to include elemental composition and rapid, computer assisted analysis permitting large numbers ofparticles to be analyzed at minimum cost.

6-28 

### April 1993MultivariateMethods Statisticalmethods include factor analysis, regression methods, principal component and cluster analysis techniques. These methods deduce information on sourceimpacts on the basis ofthe variability ofchemical species measured within a large set ofparticulate samples. Given the premise that chemical species emitted from a specific source will vary in time (as measured atthe receptor) in the same manner, multivariate methods detectthe common variability ofthe chemical species. The analyst then identifies the contributing source by comparing those species with similar variability to the chemical composition ofsources within the airshed. RadioisotopeAnalysis Measurements ofcarbon-l4/total carbon ratios have recently been used to distinguish "modern" from fossil fuel carbon. Using this method, carbon emitted from contemporary sources (wood burning, fireplaces, leaffragments) has been distinguished from particles released by the combustion offossil fuels, e.g., auto and diesel exhaust, coal and fuel oil carbonaceous aerosols. Spatial Series Analysis Spatial relationships between aerosol chemistry measured at numerous receptors can provide important clues to likely contributing sources when viewed in relation to emission density maps and given a basic understanding ofthe chemical composition ofsource emissions. Time SeriesAnalysis Qualitative indications ofsource impacts based on temporal variations in aerosol mass and chemistry can be used, in association with source emission activity and transport data, to gain insight into likely source impacts over time.

6-29 April 1993 ,"X-rayDiffraction (XRD) 

### Quantitative identification ofcrystalline substances in the coarse mode (>2.5 urn) by XRD has enabled analysts to determine impactsfrom fugitive emission sources within reasonable accuracy (±25 percent) for moderate to he!lvily loaded filters.III 

### Ofthese eight model types, the chemical mass balance (CMB) is the most widely used and accepted quantitative receptor model. (PM-tO SIP Development Guideline document p. 4-1). Sources ofinformation on the CMB model includeReceptorModel Technical Series, Volume III 

### (1989Revision): CMB7 User's Manual; ProtocolForApplying and Validating the CMB ModeL, ProtocolforReconcilingDifferencesAmongReceptor andDispersion Models; 

### and ReceptorModel Technical Series, Volume II: Chemical Mass Balance.2•3,4 Th: ProtocolforReconcilingDifferencesAmongReceptor andDispersionModels 

### states that a minimum offive samples ofexceedance-day data should be analyzed and compared. Ifthere are fewer than five observed "exceedances" ofthe NAAQS, the five highest values overall should be used. Ifareceptor model study were undertaken for a short time period, it mustbe shown that the period covered was generally representative ofthe type of source activity and meteorology associated with exceedances observed in otherreceptor model studies.s

6-30 

### April 1993

### REFERENCES FORSECTION 6.8 1. U.S. Environmental Protection Agency. ReceptorModeL TechnicaL Series. VoLume I: Overview of ReceptorModelApplication to Particulate SourceApportionment, 

### Office ofAir 

### Quality Planning and Standards, Research Triangle Park, NC. EPA-450/4-81- 016a. July 1981. pp. vii-x. 2. U.S. Environmental Protection Agency. ReceptorModeL TechnicaL Series Volume 

### III (1989Revision): CMB7 User's Manual, 

### Office ofAir Quality Planning and Standards, Research Triangle Park, NC. EPA-450/4-90-004. January 1990. 3. U.S. Environmental Protection Agency. ProtocolforReconcilingDifferencesAmong ReceptorandDispersionModels, 

### Office ofAir Quality Planning and Standards, Research Triangle Park, NC. EPA-450/4-87-008. March 1987. 4. U.S. Environmental Protection Agency. ReceptorModeL TechnicaL Series Volume 

### II: ChemicalMass Balance, 

### Office ofAir 

### Quality Planning and Standards, Research Triangle Park, NC. EPA-450/4-81-016b. July 1981. 5. "For violations ofthe 24-hour NAAQS, itis preferable to apply the CMB model on the days on which 'exceedances' ofthe NAAQS were observed. 

### III this case, one would analyze and compare all observations greater than the level ofthe NAAQS. In order to obtain representative results, a minimum offive samples (e.g., 

### the five highest values) should be compared. If

### there are fewer than five observed 'exceedances' of the NAAQS, the five highest values overall should be used so that the analysis is based upon arepresentative number ofdays. If

### areceptor model study were undertaken for a short time period, it must be shown that the period covered was generally representative ofthe types ofsource activity and meteorology which are associated with exceedances measured outside ofthe receptor model study." U.S. Environmental Protection Agency. ProtocolforReconciling DifferencesAmong ReceptorandDispersionModeLs, 

### Office ofAir Quality Planning and Standards, Research Triangle Park, NC. EPA-450/4-87-008. March 1987. pp. 5-6.

6-31 April 1993

### 7.0 STACK HEIGHT REGULATIONS

7.1 GENERAL REGULATIONS Stackheightregulations affect all criteriapollutants. Revised stack heightregulations were promulgated by EPA on July 8, 1985 and implementprovisions ofsection 123 ofthe Act which dictate that the degree ofemission limitation required for pollutant control under an applicable SIP shall not be affected by stacks in excess ofgood engineering practice (GEP), stack height, or.by any other dispersion technique.1,2 

### Stacks in 

### existence or dispersion techniques implemented before December 31, 1970 are exempt from these provisions (see Section 7.5.1 for definition of "in 

### existence").3 

### However, sources defined in section 110(a)(3) ofthe Act which were constructed, reconstructed or for which major modifications were performed after December 31, 1970 are not exemptfrom these provisions.4


### A comprehensive overview ofstack heightpolicy is contained in the Workshop on Implementing the StackHeightRegulations (Revised).5 

### This documentincludes a discussion ofSIP stack height requirements, documentation in outline format and presents several checklists for GEP stack height review.

7-1 April 1993

### REFERENCES FOR SECTION7.1

1. "Section 123, which was added to the Clean Air Act by the 1977 Amendments, regulates the manner 

### in which techniques for dispersion ofpollutants from a source may be considered 

### in setting emission limitations. Specifically, section 123 requires that the degree ofemission limitation shall not be affected bythatportion ofa stack which exceeds GEP or by lany other dispersion technique.III 50 Federal Register 27,892-907 (July 8, 1985), Stack HeightRegulation. 2. U.S. Environmental Protection Agency. Code of FederalRegulations. Title 40, ChapterI, Subchapter C, Parts 51.118, 51.164, and 52.21(h). July 1, 1991. 3. U.S. Congress. Clean Air Act, as amended November 1990. 42 U.S.C. 7401 et. seq. Section 123(a). Washington, D.C. U.S. Government Printing Office. 4. U.S. Environmental Protection Agency. Code ofFederalRegulations. Title 40, Chapter I, Subchapter C, Part 51.1l8(b). July 1, 1991. 5. U.S. Environmental Protection Agency. Workshop onImplementing the Stack Height Regulations (Revised). Office ofAir Quality Planning and Standards, Research Triangle Park, NC. October 1985.

7-2 April 1993

### 7.2 GOOD ENGINEERING PRACTICE STACK IJEIGHT

7.2.1 General Discussion ofthe technical basis and procedures for determining GEP stack height are provided in

### the GuidelineforDetermination ofGoodEngineering Practice StackHeight (Revised).l 

### GEP, with respect to stack height, is defined by section 123 ofthe Act as, "the height necessary to insure that emissions from the stack do notresult in excessive concentrations ofany air 

### pollutant in the immediate vicinity ofthe source as aresult of atmospheric downwash, eddies or wakes which may be created by the source itself, nearby structures or nearby terrain obstacles." According to 40 CFR 51.100(ii), GEP stack height is determined, quantitatively, as the greatest ofthe following elements:

• De Minimis The de minimis 

### height is 65 

### meters, measured from the ground-level elevation atthe base ofthe stack.
• FormulaHeight The formula height is given by: Hg 

# = Hg = H = L = 

### H + l.SL where, good engineering practice stackheight, measured from the ground-level elevation at the base ofthe stack height ofnearby structure(s) measured from the ground-level elevation at the base ofthe stack lesser dimension, height or projected width, ofnearby structure(s) The EPA, or State or local control agencies may require the use ofa field study or fluid modeling to verify GEP stack height for the source. For stacks in existence prior to January 12, 1979 and after December 31, 1970 for which the owner or operator had obtained all applicablepermits or approvals required under 40 CFR Parts 51 and 52, Hg

# =2.5H, provided thatthe owner or operator furnishes evidence that this equation was actually used in establishing an emission limitation.
. 7-3 April 1993For stacks which existed prior to December 31, 1970, use the actual stack height to set emission limitations.
. • Physical Demonstrations The heightmaybe demonstrated by a fluid modeling or field study approved by the EPA, which ensures that the stackemissions do not resultin excessive concentrations ofany 

### airpollutant

### as a result ofatmospheric downwash, wakes, or eddy effects created by the source itself, nearby structures ornearby terrain features (see Section 7.6).**7.~.2** 

### Definition of"Nearby" for GEP
Forthepurpose ofdetermining GEP stack height, "nearby" is limited to five times the structure height or width, whichever is less (a distance not to exceed one-halfmile) and in the case ofa fluid model or field study is limited to one-halfmile. This range may be extended for the portion ofa terrain feature which exists within a distance ofup to 10 times the maximum height ofthe feature (not to exceed two miles), ifsuch feature reaches a height, at one-halfinile from the stack, that is at least 40percent ofthe GEP stack height determined by Hg = H 

### + 1.5L above or 26 meters, whichever is greater, as measured from the groundlevel elevation at the base ofthe stack?



### 7.2.3 Definition of "Excessive Concentration" The term "excessive concentration," as it applies to a physical (fluid or field) demonstration ofGEP stack height, is defined in 40 CFR 51.100(kk) for several situations, all of which require showing a 40 percentincrease in the maximum ground-level concentration relative to the maximum concentration observed in the absence ofdownwash, wakes, or eddy effects. Certain situations also require showing thatthe stack contributes to a total concentration, due to emissions from all sources, that exceeds the NAAQS or PSD increment. The stack emission rate shall be based on an NSPS emission rate applicable to the source category unless demonstrated infeasible (See Section 7.6.4for more detailed discussion).



### 7-4 April 1993 I
.

### REFERENCES FORSECTION 7.2
1. 

### U.S. Environmental Protection Agency. GuidelineforDetermination ofGood EngiMering Practice StackHeight (Revised). Office ofAir 

### Quality Planning and Standards, Research Triangle Park, NC. EPA-450/4-80-023R. June 1985. 2. 

### U.S. Environmental Protection Agency. Code of FederalRegulations. Title 40, 

### ChapterI, Subchapter C, Part 51.100Gj). July 1, 1991.

7-5 

### April 1993 I' I I

### 7.3 DISPERSION TECHNIQUES

7.3.1 General Therevised EPA stack heightregulations generally prohibit stationary sources from taking creditfor dispersion techniques in determining allowable emission limitations.



### 7.3.2 Prohibitions As stated in 40 CPR 51.100(hh)(1), the prohibited dispersion techniques are as follows:

• Using thatportion ofa stack in excess ofGEP stack height
• Varying the pollutant emission rate according to atmospheric conditions or ambient concentrations ofthat pollutant (referred to as intermittent or supplemental control systems
- ICS or SCS)
• Increasing final exhaust gas plumerise by manipulating source process parameters, exhaust gas parameters, stackparameters or combining exhaust gases from several existing stacks into one stack, or other selective handling ofexhaust gas streams so as to increase the exhaust gas plumerise


### 7.3.3 Exceptions Although credit for selective handling ofexhaust gas streams to increase the exhaust gas plume rise is generally prohibited, in certain circumstances, creditis allowed for the following:
• Merging ofgas streams in original design and construction (also see Section 7.7)
• Smoke management techniques involved in agricultural or silviculturalprograms
• Episodic restrictions on residential wood burning and open burning
• Reheating after apollution control systeml

7-6 April 1993

### REFERENCES FORSECTION7.3
1. U.S. Environmental Protection Agency. 

### Code of FederalRegulations. Title 40, 

### ChapterI, Subchapter C, Part 51.100(hh)(2). July 

### 1, 1991.

7-7 April 1993

### 7.4 REMANDED REGULATIONS The following three portions ofthe revised EPA stack heightregulations, promulgated on July 8, 1985, were litigated and remanded to EPA for review: 1

• Under the definition ofexcessive concentration: Grandfathering pre-October 11, 1983 within-formula stack height increases from demonstration requirements [40 CFR 51.100(kk)(2)]
• Under the definition ofdispersion technique: Dispersion creditfor sources originally designed and constructed with merged or multifiue stacks [40 CFR 51.100(hh)(2)(ii)(A)]
• Under the definition ofGEP stack height: Grandfathering ofpre-1979 use ofthe unrefined "H

### + 2.5L" formula [40 CPR 51.100(ii)(2)]. As a result ofthe remand, an interim policy on stack height regulatory actions is in effect. This policy provides that most actions affected by the remand may proceed, provided appropriate caveat language is incorporated indicating that the action is subject to review and modification on completion ofEPA's response to the court decision?

7-8 April 1993 

# ..

### REFERENCES FOR SECTION7.4

1. "Althoughthe courtupheld mostprovisions ofthe rules, three portions were remanded to EPA for review: 1. Grandfatheringpre-October 11, 1983 within-formula stack heightincreases from demonstrationrequirements [40 CFR 51.100(kk)(2)]; 2. Dispersion creditfor sources originally designed and constructed with merged or multifiue stacks [40 CFR 51.100(hh)(2)(ii)(A)]; and 3. Grandfathering ofpre-1979 use oftherefined H + 1.5L formula [40 CFR 51.100(ii)(2)]." Memorandumfrom Potter, 

### J.C., OAR, to AirManagement Division Director, Regions

### I, 

### ill, and 

### IX, Air and Waste ManagementDivision Director, Region 

## n, Air, Pesticides, and Toxics Management Division Director, Regions 

### IV, and 

### VI, Air and Radiation Division Director, Region 

### V, Air and Toxics Division Director, Regions 

## vn, VITI, and 

### X. InterimPolicy on StackHeightRegulatory Actions. April 22, 1988. 2. "In general, actions taken atthis time to approve or disapprove statewide stack height rules which are affected by the remand must include the qualification thatthey are subjectto review and modification on completion ofEPA's response to the court decision." Memorandum from Calcagni, 

### 1., OAQPS, to AirBranch Chief, Regions 

### I-X. Application ofthe Interim Policy for StackHeight Regulatory Actions. May 17, 1988. (PN 123-88-05-17-016).

7-9 April-I993

### 7.5 SPECIFIC STACK HEIGHT POLICIES

7.5.1 Definition of 

### "InExistence" In

### promulgating the 1982 stackheightregulations, EPA adopted a definition of "stack heights in existence before December 31, 1970."1 This definition allowed the grandfathering ofstacks either: (a) physically completed; (b) for which continuous construction had begun; or (c) for which construction had notyet commenced, but for which binding contracts had been signed that could not be canceled without substantial loss to the source owner or operator. Therevised stack heightregulation promulgated on July 8, 1985 does not modify this definition except to restrict its applicability to facilities that have not undertaken major modifications orreconstruction and have notducted effluent gas streams from post-1970 units into pre-1971 stacks? Grandfathering exemptions may be supported in one ofthree ways.3 (1) In the case ofstacks physically completed prior to December 31, 1970, proofof stack completion must be documented (an acceptable form ofdocumentation, for example, would be a copy ofthe 1970 Federal Power Commission ReportForm 67, which includes information on stack height); (2) Evidence submitted to supportthe commencement date ofstack construction can include any contemporaneous documentation such as building inspection records, delivery receipts ofconstruction materials, or news clippings that clearly indicate that construction activities were under way before December 31, 1970; or (3) Date ofsignature on a contractfor stack construction is acceptable for applying

.grandfathering exemptions provided the "binding contract" is one that commits the

source owner or operator to financially undertake stack construction and that did not have an "escape" provision in effect on December 31, 1970 allowing cancellation by the owner or operator without penalty. H

### a contract contains provisions for assessing penalties for modification or cancellation that were in effect before December 31, 1970, then the provisions must be reviewed to determine whether the penalties and other costs ofcancellation would have imposed a "substantial loss" on the owner or operator. In 

### general, EPA willpresume that a substantial loss would have resulted in those situations in which penalties exceed 10 percent ofthe projectcost. Documentation supporting any ofthese grandfathering exemptions must be made available for public review by the State or source owner or operator.4


### 7-10 April 1993 I ,. '"

### 7.5.2 Tie-ins to Existing Stacks The definition of "source" that should be used in determining whether tie-ins to grandfathered stacks should be pennitted orprohibited is a single emission unit. Hence, creditfor tying a single, post-1970 unit(s) into a grandfathered stack serving a number ofold units is prohibitedunder the revised stackheightregulations.S

7-11 

### April 1993

### REFERENCES FOR SECTION 7.5
1. 

### "Grandfathered StackHeight. The 1970 Clean 

### Air Act became effective on December 31, 1970. Prior to that date some sources had constructed stacks taller than their GEP height. In 

### section 123, Congress recognized this and exempted those sources' stack heights. Section 123 allows credit for stackheight in existence on December 31, 1970. A source's stack is considered to be 'in

### existence' if

### that stack was part ofthe design ofafacility on which construction commencedpriorto December 31, 1970." 47 Federal Register 5,865-69 (February 8, 1982), StackHeight Regulations. 2. "The EPA's definition was upheld by the U.S. Court ofAppeals for the D.C. circuit in Sierra Club v. EPA, 719 F.2d 436, and has not been modified in any way by the rule revisions promulgated on July 8, 1985, except to restrictits applicability to facilities that have not undertaken major modifications orreconstruction, and have not dueted the effluent gas streams from post-1970 units into pre-1971 stacks." Memorandum from D.D., Tyler, OAQPS, to Regional Air Management Division Director, Regions I-X. Determining StackHeights "In 

### Existence" Before December 31, 1970. October 28, 1985. (pN 123-85-10-28-010). 3. Memorandumfrom D.D., Tyler, OAQPS, to Regional Air Management Division Director, Regions I-X. Determining Stack Heights "In Existence" Before December 31, 1970. October 28, 1985. (pN 123-85-10-28-010). 4. "The burden ofprooffor showing that a stack is eligible for grandfathering exemption lies with either the State or the source owner or operator, as appropriate, and documentation in support ofexemptions must be made available for public review during the rulemaking process." Memorandum from D.D., Tyler, OAQPS, to Regional Air Management Division Director, Regions I-X. Determining Stack Heights "In Existence" Before December 31, 1970. October 28, 1985. (PN 123-85-10-28-010). 5. "Q: What 'source' definition should be used in determining whether tie-ins to grandfathered stacks should be permitted or prohibited? A: The term 'source' in this instance means a single emitting unit. Thus, credit for tying a single post-1970 unites) into a grandfathered stack serving a number ofold units is prohibited under the regUlation." Memorandum from Helms, G.T., OAQPS, to Air Branch Chief, Regions I-X. Questions and Answers on Implementing the Revised Stack Height Regulation. October 10, 1985. (PN 123-85-10-10-007).

7-12 April 1993

### 7.6 DEMONSTRATIONS BY FLUID MODELING, FIELD ST-UDIES OR NIDSANCE

7.6.1 Applicability Sources seeking creditfor stack height above GEP fonnula height must demonstrate by a field study or fluid modeling analysis that this heightis necessary to avoid excessive pollutant concentrations as aresult ofdownwash, wakes or eddy effects created by the source itself, nearby structures ornearby terrain (refer to Section 7.2 for definitions of "excessive concentration" and "nearby").l Sources seeking credit within fonnula height may also need to conduct such demonstrations in those cases where itis believed thatthe fonnula may significantly overstate the appropriate stack height credit, and tojustify certain increases in stack height.2 Sources seeking creditfor increasesin stackheights up to fonnula GEP mayjustify the increase by demonstrating the actual presence ofa local nuisance caused by the existing stack, as determined by the authority administering the SIP.3



### 7.6.2 Field Studies A field demonstration ofGEP heightinvolves the
.installation and operation ofa monitoring network designed to clearly identify maximum downwind concentrations. Concentrationpatterns from two release points must be determined: one near the source in the presence ofstructure(s) and/or terrain and the otherin the absence ofsuch features. Except for differences due to structure(s) and/or terrain, the atmospheric flow at the latter location must be similar to that near the source, as verified by meteorological observations upwind of both sites.4



### 7-l3 April 1993

### 7.6.3 Fluid Modeling CreditforHeightAbove GEP Formula. In

### performing fluid modeling demonstrations, sources seeking credit for stacks greater than formula heightmustuse the appropriate emission ratefor the source category (see Section 7.6.4) and add the background air quality as determined by procedures described in 

### Section 6.5.3.5 

### The following "excessive concentration" criteria must be met: (a) exceedance ofthe NAAQS or PSD increment, and (b) a concentration ofatleast 40percentin excess ofthe maximum concentration experiencedin the absence ofdownwash, wakes or eddy effects. After these criteria are met, the source must use the lowest stack height necessary to meet the more restrictive ofthe two excessive concentration criteria in order to set emission limitations. This lowest height becomes the new GEP height6 

### CreditforHeightLess than orEqual to GEP Formula. For sources seeking credit after October 11, 1983 for increases in 

### existing stack height up to GEP formula height, the excessive concentration criteria (a) and (b) given above generally apply. For sources seeking credit after January 12, 1979 for a stack height less than or equal to formula height; for sources seeking credit after November 9, 1984 based on the aerodynamic influence ofcooling towers; and for sources seeking credit after December 31, 1970 based on the aerodynamic influence ofstructures not adequately represented by GEP formula, the 40 percent excess concentration is the only criterion needed to demonstrate equivalence to formula height.7



### 7.6.4 Emission Rate for Physical Demonstrations For sources seeking credit above formula GEP heil!ht, the stack height regulations require that apresumptive emission rate equivalent to the NSPS be established for the source in question before fluid modeling is initiated to determine the stack height necessary to avoid excessive concentrations due to downwash.8 The NSPS emission rate is "presumptive" in 

### that EPA presumes that all 

### sources seeking tojustify stack heights in excess ofthose established by GEP formulae are capable ofcontrolling their emissions to NSPS levels. If

### it is infeasible for a source to control its emissions to NSPS levels, then an alternative emission limit representing the lowestfeasible emission limit mustbe met before credit for stack height in 

### excess ofGEP formula height can be obtained. These alternative emission rates will be reviewed by EPA based on the Best Available Retrofit Technology (BART) guidelines.9,lo


### 7-14 April 1993Unless the source owner or operator demonstrates that the emission rate prescribed by the NSPS applicable to the source category is infeasible, the allowable emission rate to be used in conducting the field study or fluid modeling demonstrations must be the NSPS emission
_ rate.11 Incases where no NSPS limitis applicable, a BART analysis must be conducted to determine the emissionrate to be used in studies demonstrating GEP stack height greater than formula height12 For certain sources seeking creditfor increases in existing stack heights up to GEP formula height, the emission rate used in the demonstration shall be the emission rate specified by the applicable SIP, or, in the case ofno established limit, the actual emission rate shall be used. 13 For other sources for which verification ofcorrect GEP height is requested, the satisfying40 percent excess concentration criterion is sufficient demonstration. 14



### 7.6.5 Not in Ambient Air For the purpose ofthe physical demonstration, the exceedance ofthe NAAQS or PSD increment need not occur at a location meeting the definition ofambient 

### air.1S



### 7.6.6 Additional Guidance Sources ofguidance on conducting fluid modeling demonstrations have been identified by EPA. 16 Documents which form the basis ofinformation include Guidelinefor Use of FluidModeling to Determine GoodEngineering StackHeight;17 Determination ofGood Engineering Practice StackHeight

-A FluidModelDemonstration Studyfor a PowerPlant;18 Guidelinefor FluidModeling of AtmosphericDif/usion;19 and FluidModelingDemonstration ofGoodEngineering Practice StackHeight in Complex Terrain.20

7-15 April 1993

### REFERENCES FOR SECTION 7.6

.1. U.S. Environmental Protection Agency. Code of FederalRegulations. Title 40, ChapterI, Subchapter C, Pan51.100(ii)(3). July 1, 1991. 2. "Nevertheless, inresponse to the court'sremand, EPA is includingin this final rule a provision for the authority administering these rules to require field studies orfluid modeling demonstrations, even for stacks builtto formula height, in cases where it believes that the formula may significantly overstate the appropriate stackheight credit. (Quite apartfrom any such regulatory provision, States have authority to require such demonstrations, on the terms outlined or on stricter ormore lenientterms, under the savings provision ofsection 116 ofthe Oean 

### AirAct)." 50 Federal Register 27,892-907 (July 8, 1985), StackHeight Regulations. 3. "
... (ii) the actualpresence ofa local nuisance caused by the existing stack, as determined by the authority administering the State implementation plan;." U.S. Environmental Protection Agency. Code ofFederalRegulations. Title 40, Chapter I, Subchapter C, Pan51.100(kk)(2). Washington, D.C. Office ofthe Federal Register. July 1, 1991. 4. "A field demonstration ofGEP stack heightrequires experiments to determine the concentration patterns from two release points

-- one with the structure(s) and/or terrain; the other in the absence ofstructure(s) and/or terrain. [A] monitoring array mustbe arranged to clearly identify the maximum concentrations downwind ofsimilar releases at both sites." U.S. Environmental Protection Agency. Guidelinefor Determination ofGoodEngineering Practice StackHeight (Technical Support
. DocumelltFor the StackHeightRegulations) (Revised). Office ofAir Quality Planning and Standards, Research Triangle Park, NC. EPA-450/4-80-023R, June 1985. p.47. 5. "In conducting a demonstration, a source should use the modeled stackheight, input the applicable emission rate that is equivalentto NSPS for that source category (however, sources may on a case-by-case basis demonstrate that such an emission is notfeasible for their situations and determine their emission limitations based on Best Available Retrofit Technology), and add in the background air quality as determined byprocedures contained in two EPA guidance documents (EPA, 1978, 1981)." U.S. Environmental Protection Agency. GuidelineforDetermination ofGoodEngineering Practice StackHeight (Technical SupportDocumentFor the StackHeightReguLations) (Revised). Office ofAir Quality Planning and Standards, Research Triangle Park, NC. EPA-450/4-80-023R, June 1985. p. 52.

7-16 April 1993

### 6. "After demonstrating thatboth excessive concentration criteria are metas defined in section 1, the source mustdetennine the lowest stackheight necessary to meet the morerestrictive ofthe two excessive concentration criteria. Thislower heightis the new GEP height" U.S. Environmental-Protection Agency. 

### Guidelinefor Determination ofGoodEngineering Practice StackHeight (TechnicalSupport DocumentForthe StackHeigh(Regulations) (Revised). Office ofAir 

### Quality Planning and Standards, Research Triangle Park, NC. EPA-450/4-80-023R, June 1985. p. 52. 7. U.S. Environmental Protection Agency. 

### Code of FederalRegulations. Title 40, ChapterI, Subchapter C, Part 51.100(kk)(3). July 1, 1991. 8. "Theregulationsrequire thata presumptive emission rate equivalentto the new source performance standards (NSPS) be established for the source in

### question before modeling may be conducted to determine stack height needed to avoid excessive concentrations due to downwash (where the NSPS has been subjectto revision, and the source in question is not subjectto the revised NSPS, the earliest standard will be applied; 

### e.g., for powerplants a rate of 1.2 lb/MM Btu would be used)." Memorandum from Tyler, D.O., OAQPS, to Regional AirManagement Division Director, Regions I-X. Implementation ofStackHeightRegulations

- Presumptive NSPS Emission Limitfor fluidModeling Stacks Above Formula GEP Height. October 28, 1985. (pN 123-85-10-28-009). 9. "This emission rate is described as 'presumptive' because it is EPA's presumption that all sources seeking tojustify stack heights exceeding those provided by the GEP formulae are capable ofcontrolling their emissions to NSPS levels. However, the regulations also allow source owners or operators to rebut this presumption, establishing an alternative emissionrate thatrepresents the most stringentlevel of control that can feasibly.be metby that source in excess ofthe NSPS level. In 

### the preamble to the regulations, EPA indicated thatit will

### rely on the 'Guidelines for Determination ofBest Available Retrofit Technology for Coal Fired Power Plants and other Existing Stationary Facilities' EPA-450/3-80-009b (BART Guidelines) when reviewing these rebuttals." Memorandum from Tyler, D.O., OAQPS, to Regional Air Management Division Director, Regions I-X. Implementation ofStackHeight
. Regulations

- Presumptive NSPS Emission Limitfor fluid Modeling Stacks Above Formula GEP Height. October 28, 1985. (PN 123-85-10-28-009). 10. "In 

### conclusion, we are in full agreement with the position taken by Region ill

### that sources seeking credit above formula height must meet an emissionrate consistent with BART/NSPS." Letter from Gerald A. 

### Emison, G.A., OAQPS, to J.P. Proctor. April 20, 1989. 11. "Q: Can new or modified sources who have agreed to a case-by-case bestavailable control technology (BACT) emission rate be required to use this rate for fluid modeling rather than a less strip.gent new sourceperformance standard (NSPS)

· emissionrate? A: As set forth in 40 CFR 51.1(kk), the allowable emission rate to be 7-17 April 1993used in making demonstrations under thispart shall be prescribed by the NSPS thatis applicable to the source category unless the owner or operator demonstrates that this emissionrate isinfeasible." Memorandumfrom Helms, G.T., OAQPS, to 

### AirBranch Chief, Regions I-X. Questions and Answers on Implementing

-theRevised 

### Smck HeightRegulations. October 10, 1985. (PN 123-85-10-10-007). 12. "Issue: A source seeking stack height credit above formula GEPisrequired by regulation to demonstrate an exceedance ofan ambient air quality standard. The regulation also provides that the allowable emissionrateto be used in making the demonstration shallbe the new sourceperformance standard (NSPS), unless this is shown to be infeasible. Theregulations, however, do not address what emission rates to use when there are no NSPS emissionrates applicable. Answer: The preamble to the stack heightregulation is clear that the emissionrate must be limited to the NSPS orbest available retrofit technology (BART) rate (50 FR 27898). The legislative history ofthe stackheightrequirement cautioned that creditfor stacks above formula heightbe granted only inrare cases. Forthis reason, EPA determined that sources seeking credit above formula height should first attempt to reduce their emissions. In establishing an emissionrate other than NSPS, the preamble states thatEPA will rely on its BART guideline. Thus, we believe that a BART analysis must

### be conducted to determine the emission rate to be used in studies demonstrating GEP stackheight greater than formula height when no NSPS limitis applicable." Memorandum from Calcagni, J., OAQPS, U.S. EPA, to I.L. Dickstein. StackHeight Questions. November 27, 1990. 13. U.S. Environmental Protection Agency. 

### Code of FederalRegulations. Title 40, ChapterI, SubchapterC, 51.100(kk)(2). July 1, 1991. 14. U.S. Environmental Protection Agency. 

### Code of FederalRegulations. Title 40, ChapterI, Subchapter C, Part 51.100(kk)(3). July 1, 1991.
. 15. "Q: Must the exceedance ofNAAQS orPSD incrementdue to downwash, wakes or eddies occur ata location meeting the definition ofambient air? A: No, the exceedance may occur at any location, including thatto which the general public does not have access." Memorandumfrom Helms, G.T., OAQPS, U.S. EPA, to Air Branch Chief, Regions I-X. Questions and Answers on Implementing the Revised Stack HeightRegulations. October 10, 1985. (PN 123-85-10-10-007). 16. Memorandum from Tikvart, J.A., OAQPS, U.S. EPA, to D. Stonefield, OAQPS. 

### Guidance onFluidModel DemonstrationsforDetermining GEP StackHeight in Complex Terrain. September 19, 1985. (PN 123-85-09-19-006). 17. U.S. Environmental Protection Agency. 

### Guidelinefor Use ofFluidModeling to Determine GoodEngineering StackHeight. Office of

### Air Quality Planning and Standards, Research Triangle Park, NC
. 

### EPA-450/4-81-003. July 1981.

7-18 April 1993

### 18. U.S. Environmental Protection Agency. Determination ofGoodEngineering Practice StackHeight

-A FluidModelDemonstration Studyfor aPowerPlant. 

### Environmental ScienceResearchLaboratory. EPA-600/3-83-024. April 1983.
. 19. U.S. Environmental Protection Agency. Guidelinefor FluidModeling of Atmospheric Diffusion. 

### Environmental Science Research Laboratory. EPA-600/8-81-009. 20. U.S. Environmental Protection Agency. FluidModeling Demonstration ofGood Engineering Practice StackHeight in Complex Terrain. 

### Atmospheric Sciences Research Laboratory, EPA-600/3-85-022. April 1985.

7-19 April 1993

### 7.7**~RGED** 

### STACKS

7.7.1 General Dispersion creditfor the retrofit combining or merging ofgas streams is generally not allowed under the stack heightregulations. 1 Originally designed and constructed merged streams are creditable atthis time [40 CFR 51.100(hh)(2)]; however, this provision is affected by the stack heightremand (see Section 7.4).



### 7.7.2 Exceptions Creditfor retrofit merging is allowed under the following circumstances:2

• After July 8, 1985 such merging is part ofa change in facility operation that includes the installation ofpollution controls and is accompanied by a netreduction in the allowable emissions ofapollutant. This exclusion from the definition of "dispersion techniques" shall only apply to the emission limitation for the pollutant affected by such change in operation; and
• Before July 8, 1985 such merging: (1) was part ofa change in operation at the facility thatincluded the installation ofemission control equipment; (2) was conducted for sound economic orengineering reasons;3 or (3) was not "significantly motivated by an intent to obtain emissions creditfor increased dispersion."4 Such a demonstration could be made by submitting evidence showing that consideration ofdispersion advantages was conspicuously absent in the intent ofthe source owner or operator.5 In addition, exemption from prohibitions on gas stream merging isprovided for sources which constructed their stacks before December 31, 1970. It is incumbent on the State or source owner or operator to demonstrate that any retrofit merging was not motivated by an intent to avoid emission controls. Information indicating that merging was specifically carried out to increase final exhaust gas plumerise serves as a demonstration ofdispersion intent thatjustifies denial ofcredit for merged gas streams.6

7

-20 April 1993

### REFERENCES FORSECTION 7.7

1. Memorandumfrom Tyler, D.O., OAQPS, U.S. EPA, to Air Management Division Directors, Regions I-X. Implementation ofStack HeightRegulations

- Exceptions FromRestrictions on Creditfor Merged Stacks. October 28, 1985. (pN 123-85-10-28-008). 2. U.S. Environmental Protection Agency. Code of FederalRegulations. 

### Title 40, ChapterI, Subchapter C, Part 51.100(hh)(2)(ii). July 1, 1991. 3. "Sources that are not covered under these criteria may still qualify for exemption if 

### they can show thatmerging was conductedfor.sound economic or engineering reasons." Memorandum from Tyler, D.O., OAQPS, U.S. EPA, to Air Management Division Directors, Regions I-X. Implementation ofStack Height Regulations

- Exceptions FromRestrictions on Creditfor Merged Stacks. October 28, 1985. (PN 123-85-10-28-008). 4. "In some instances, a State or emission source owner may not be able to make a demonstration as described above, or believe that sound economic reasons existed for merging stacks, regardless ofthe relationship between financial savings attributable to reduced emission control requirements versus lower stack construction costs. In such cases, an opportunity should be provided to affmnatively demonstrate that merged stacks were not 'significantly motivated by an intentto obtain emissions creditfor increased dispersion'." Memorandum from Tyler, D.O., OAQPS, U.S. EPA, to Air Management Division Directors, Regions I-X. Implementation ofStack Height Regulations

- Exceptions From Restrictions on Credit for Merged Stacks. October 28, 1985. (PN 123-85-10-28-008). 5. "Forinstance, such ademonstration could be made by submitting documentary or other evidence (e.g., 

### internal company memoranda presenting the alternative construction opportunities available to the company) thatindicates the intent ofthe source owner or operator and shows that consideration ofdispersion advantages was conspicuously absent." Memorandum from Tyler, D.O., OAQPS, U.S. EPA, to Air Management Division Directors, Regions I-X. Implementation ofStack Height Regulations

- Exceptions From Restrictions on Creditfor Merged Stacks. October 28, 1985. (PN 123-85-10-28-008). 6. 

### "Because merged gas streams are generally regarded as prohibited dispersion techniques under the regulations, itis incumbent on the State or the source owner or operator to demonstrate that such merging was conducted for sound economic or engineering reasons, and was not significantly motivated by an intent to avoid emission controls. Consequently, the first step should entail areview ofState and EPA files to determine the existence ofany evidence ofintent on the part ofthe source owner or operator. Information showing that merging was conducted 7-21 April 1993specifically to increase final exhaust gas plume rise serves as a demonstration of dispersion intentthatjustifies a denial ofcreditfor merged gas streams." Memorandumfrom Tyler, D.O., OAQPS, U.S. EPA, to Air ManagementDivision Directors, Regions I-X. Implementation ofStack Height Regulations

- Exceptions FromRestrictions on Creditfor Merged Stacks. October 28, 1985. (PN 123-85-10-28-008).

7-22 April 1993

### 7.8 STA.CK HEIGHT NEGATIVE DECLARATIONS

7.8.1 General FollowingpromUlgation ofthe revised stack heightregulations on July 8, 1985, each State was required to review its SIP and determine if

### any sources were credited with stack heights or dispersion techniques not in accordance with the revised regulations. l 

### Where sources are found to be in 

### compliance with the revised regulations, a "negative declaration" is issued in the Federal Register for that State. A Federal Register notice ofnegative declaration for the stack heightrequirements does notneed to be incorporated into the SIP since it is notrequired under section 110 ofthe Act.



### 7.8.2 Information Needed There are three primary ways to declare a source as unaffected by the stack height

• Source was constructed prior to December 31, 1970
• Source stackheight is less than GEP formula height
• Source emission limitation was not affected by stack height or by any other dispersion technique It

### is very important that a description ofthe grandfathering documentation is provided along with the date ofdocumentation, so thatproofofthe grandfathering can be easily traced back to a specific document.3



### 7.8.3 Modeling Needed Source remodeling would be required in those situations in which credit for excess stack height or dispersion techniques has been taken. Any remodeling must follow the



### 7-23 April 1993

### Guideline onAir QualityModels (Revised) and Supplement

### A.4 Ifa source has never been analyzed for dispersion, then no modeling is required.s

7-24 April 1993REFERENCES FOR SECTION 

### 7.8

1. 

### "(2)(B) nine months after date ofpromulgation
..." U.S. Congress. Clean Air 

### Act, as amended August 1977. 42 U.S.C. 1857 et. seq. section 406(2)(b). Washington, D.C. U.S. Government Printing Office. November 1977. 2. U.S. Environmental Protection Agency. Workshop onImplementing the StackHeight Regulations (Revised). Control Programs Development Division, Office ofAir 

### Quality Planning and Standards, Research Triangle Park, NC. October 1985. 3. "For grandfathering documentation, the date the source was builtis not essential, but the type and date ofthe documentation that the source was builtprior to December 31, 1970, mustbe listed." Memorandum from Helms, G.T., OAQPS, U.S. EPA, to Air Branch Chief, Region I-X. Processing ofStack Height Negative Declarations. October 9, 1987. (PN 123-87-10-09-014). 4. U.S. Environmental Protection Agency. Guideline onAir QualityModels (Revised). Office ofAir Quality Planning and Standards. Research Triangle Park, NC. EPA450/2-78-027R. July 1986. 

### 5. "If

### a source has never been analyzed for dispersion, then itis not necessary to conduct a dispersion analysis now." Memorandum from Tyler, D.D., OAQPS, U.S. EPA, to Air Division Director, Regions I-X. Clarification ofExisting Guidance on Dispersion Modeling Requirements for Plants with "Tall Stacks" and Other Prohibited Dispersion Techniques. February 11, 1986. (PN 123-86-02-11-012).

7-25 April 1993

### 8.0 CONTROL STRATEGIES

8.1 GENERAL Pursuant to section llO(a)(2) ofthe amended act, each SIPmust contain an enforceable control strategy thatprovides the degree ofemissions reductions required to ensure attainment and maintenance ofall NAAQS. The emissions reductions must be sufficient to offset any expected increases in concentrations ofairpollutants that might result from population growth, industrial activity, motor vehicle traffic, or other factors. l In 

### general, a control strategy will consist ofemission limitations applicable to sources within specified categories. Specific emissions limitations are established based on what is required for NAAQS attainment.

8-1 

### April 1993

### REFERE, NCES FOR SECTION 8.1

1. "Eachplan must setforth a control strategy thatprovides the degree ofemission reductions necessary for attainment and maintenance ofthe national ambient air quality standards. The emission reductions mustbe sufficientto offset any increase in air quality concentrations that are expected due to projected growth ofpopulation, industrial activity, motorvehicle traffic, or other factors." 51 FederalRegister 40,665 (November 7, 1986), Attainment and Maintenance ofNational Standards.

8-2 April 1993

### 8.2 CONTROL STRATEGYTRANSITION Particulate matter emissions from mostpoint

### sources- arretmany-area-somces- Itave-been 

### controlled through SIP's designed to implementthe former NAAQS for total suspended particulate (TSP). Existing regulatoryrequirements (e.g., 

### emission limitations) must continue to be enforced by Federal and State agencies during the transition from a TSP SIP to a PM10 SIP. H the existing regulations require using reasonably available control technology (RACT), 

### thisrequirementcontinues and sources must comply with theregulations. Existing emissionsrequirements can be 

### relaxed only ifthe State uses dispersion modeling to demonstrate that ahigher allowable emissionrate will notresultin degradation ofthe existing air 

### quality and that the PM-lO NAAQS will be maintained. States should utilize the existing control strategy in a TSP SIP as the basis for a PM-lO SIP!,2,3

8-3 April 1993

### REFERE
. NCES FORSECTION 8.2

1. "Existing regulatoryrequirements (e.g., emission PM limits) must continue to be enforced by Federal and State agencies during the transition from a total suspended particulate (TSP) SIP to a PM-I0 SIP. Ifthe existingregulations require using reasonably available controltechnology (RACT), this requirement continues and sources must comply with the regulation. Existing emissions requirements can be relaxed only 

### ifthe State demonstrates with dispersion modeling that a higher allowable emission rate will notresultin degradation ofthe existing air quality and still maintain the PM-1O NAAQS." U.S. Environmental Protection Agency. PM-10 SIP Development Guideline

- Supplement. Office ofAir Quality Planning and Standards. June 1988. p. 15. 2. "Particulate matter emissions from most point sources and many area sources have been controlled through SIP's designed to implementthe former NAAQS for TSP
... States should utilize the existing control strategy in a TSP SIP as the basis for a PM10 SIP." U.S. Environmental Protection Agency. PM-10 SIP Development Guideline. Office of

### Air QUality Planning and Standards. EPA-450/2-86-001. June 1987 p. 7-6. 3. "The State should focus on developing approvable PM-1O SIP's. However, it is likely that the elements ofthe TSP SIP that were disapproved will be needed for the PM-lO SIP." U.S. Environmental Protection Agency. Response to Questions Regarding PM10 State Implementation Plan (SIP) Development. Office ofAir Quality Planning and Standards. June 1988. p. 33.

8-4 April 1993

### 8.3 ESJ'ABLISHING EMISSION LIMITATIONS

8.3.1 General Emission limitations for pointand area sources ofPM-IO are established based on an analysis ofambientconcentrations and source contributions to determine the level ofcontrol needed to demonstrate attainment ofthe NAAQS. This involves determination ofdesign concentrations for the appropriate averaging intervals for each location that must

### be reduced to the level ofthe respective NAAQS. After design concentrations have been established, a proportioning method is used to estimate the required emission limitations for primary PM10.1
Under section 189(e) ofthe Act, the control requirements applicable for major stationary sources ofPM-lO are also applicable to major stationary sources ofPM-lO precursors, exceptwhere EPA determines that such sources do not contribute significantly to PM-lO levels which exceed the PM-lO NAAQS in the area. Such a determination will be based on air quality analyses, technical information provided by individual States, and on any other studies conducted by the State or EPA which may help to indicate whether major stationary sources ofspecific precursors contribute significantly to PM-lO concentrationsin a particular area. EPA intends to make a formal determination as to whether major stationary sources ofPM-lO precursors contribute significantly to PM-lO levels in a particular area when it takes rulemaking action on the individual moderate area SIP's? Section 8.4.4 ofthis guideline provides a more detailed discussion ofEPA policy on PM-lO precursors.



### 8.3.2 Design Concentrations The design concentration is the ambient PM-lO level for a particular site that must be reduced to the level ofthe NAAQS. With the PM-lO annual and 24-hour NAAQS, two separate design concentrations, one for each standard, are needed per site. The annual design concentration is the expected annual arithmetic mean determined in accordance with Appendix K to 40 CPR Part 50. The 24-hour design concentration is the level at which the expected number ofexceedances ofthe 24-hour standard is less than or equal to one. There are several acceptable approaches for determining the expected number ofexceedances ofthe
8-5 April 1993

### 24-hour standard. These include a table look-up procedure, fitting a statistical distribution, graphical estimation, and conditionalprobabilities.3 

### Design concentrations may be 

### based on ambientmeasurements ofPM-lO, or model estimates ofambientconcentrations atindividual sites during one or more years ofstable emissions conditions. In all 

### cases where dispersion model estimates are used, the design concentration is assumed to be 

### the sum ofthe concentrations contributed by the sources and an appropriate background concentration. Thepreferred approach for estimating a design value is through the use ofan applicable dispersion model corroborated by receptor models, any available PM-lO data, and any available TSP data. If

### corroboration is notpossible, a dispersion model should be 

### used exceptfor periods ofstagnation. Monitoring data should be used for stagnation periods.4 In 

### limited instances, the use ofa receptor model alone may be sufficient to demonstrate attainment. Approval for such an approach must be obtained prior to SIP submittal.s The uncertainty in the design concentration estimate is 

### reduced to the extent that sufficient, representative meteorological and monitoring data are available. Modeling estimates using 5 years ofNational Weather Service meteorological data (or atleast one year ofon-site data), or three years ofrepresentative air

### quality measurements should be considered in determining 24-hour design concentrations. If

### more years ofdata with relatively unchanging emissions are available, they also may be considered in calculating design concentrations.4



### 8.3.3 Averaging Periods Enforceable emission limits must be sufficient to protect both the short-term (24-hour) and annual NAAQS for PM-lO. Thus, SIP emission limits should be based on the NAAQS (annual or 24-hour) which result in the most stringent control requirements.6 

### Each emission limit must state the appropriate averaging time for that limit. Specific control measures designed to achieve the required emission limitations must then be implemented in the SIP (40 CPR 51.111). Specific control measures for PM-lO are discussed in Section 8.4 ofthis guideline.

8-6 April 1993

### 8.3.4 Compliance Methods Each SIP must identify methods for determining compliance 

### with the emission limitations, according to requirements in 40 CPR 51.111. These methods must be consistent with the averaging period appropriate to eachlimitation. Thus, a SIP may contain separate compliancetestmethods for each averaging period. According to section 504(b) ofthe Act, compliancemay 

### be detennined by any method thatprovides sufficientlyreliable and timely information for determining compliance, notwithstanding specific requirements elsewhere in the Act. Such methods include source testing, continuous emissions monitoring, or monitoring operating parameters related to the emission rate. Section 11.4 ofthis guideline provides a more detailed discussion ofcompliance

-monitoring.

8-7 April 1993**REFERE~CES** FOR

### SECTION 8.3

1. "Once PM-lO design concentrations have been established through the use ofair quality measurements ormodel estimates, a proportioning method can be used at each site to estimate control requirements for SIP development. This proportioning method differs from simplerollbackin that the source contributions are determined from receptor ordispersion modeling and not directly from the emissions as in simple rollback." U.S. Environmental**Prote~tion** 

### Agency. PM-10 SIPDevelopment Guideline. 

### Office ofAir Quality Planning and Standards. EPA-450/2-86-001. June 1987.p. 6-8. 2. "
...the controlrequirements applicable under PM-lO SIP'sin effectfor major stationary sources ofPM-lO are also applicable to major stationary sources ofPM-lO precursors, except where EPA determines that such sources do not contribute significantly to PM-lO levels which exceed the PM-lO NAAQS in the area ... a determination will be based on air

### quality analyses, on any additional technical information discovered by individual States during SIP development, and on any other studies conducted by the State or EPA which may help to indicate whether major stationary sources ofspecific precursors contribute significantly to PM-lO concentrations in 

### a particular area....EPA intends to make a formal determination as to whether major stationary sources ofPM-lO precursors contribute significantly to PM-lO levels in a particular area when it takes rulemaking action on the individual moderate area SIP's." 57 Federal Register 13.541 (April 16, 1992), General Preamble for the Implementation ofTitle I ofthe Clean Air Act Amendments of 1990; Proposed Rule; SIP Requirements; Particulate Matter; Determination ofRACM/RACf; PM-lO Precursors. 3. "There are several acceptable approaches for determining appropriate 24-hour PMIO 

### design concentrations. These approaches which are described in the next sections are based on monitored or modeled PMIO 

### concentrations. They include: (1) 

### a table lookup procedure; (2) fitting a statistical distribution; (3) graphical estimation; and (4) 

### the use ofconditional probabilities. Each ofthese approaches and corresponding data usage requirements are presented in detail in the ozone guideline." U.S. Environmental Protection Agency. PM-10 SIP Development Guideline. 

### Office ofAir Quality Planning and Standards. EPA-450/2-86-001. 

### June 1987. pp. 6-1 through 6-8. 4. 

### "Section 6.2 ofthe PM-lO SIP Development Guideline states that the preferred approach for estimating 

### adesign value is through the use ofan applicable dispersion model corroborated by receptor models, any available total suspended particulates data, and any available PM-lO data. Ifcorroboration is not possible, we recommend that the dispersion model be used except for periods ofstagnation; for periods of stagnation, monitored PM-lO data should be used to establish the design value." Memorandum from Emison, Gerald A., 

### Director, OAQPS, U.S. EPA, to Irwin L.


### 8-8 April 1993 

# r**Di~kstein,** 

### Director, Air 

### and Toxics Division, Region VIII. Response to PM-IO Control Strategy Issues. June 30, 1989. (PN 110-89-06-30-103). 5
. "It is appropriatein certain situations to rely on areceptor model (RM) 

### demonstration as a basisfor a control strategy demonstration. While itis clearfrom the guideline that the use ofdispersion models in combination with receptor models is the preferred approach, in certain limited situations, the use ofan RM 

### demonstration alone may be adequate to demonstrate attainment. The State must obtain approval to use the RM 

### demonstration option prior to SIP submittal. The decision that an RM 

### demonstration is adequate to demonstrate attainmentis the responsibility ofthe Regional Office. Even when an RM

### is employed, consideration should be given to initiation ofbasic meteorological measurements as a contingency to the control programbeing found inadequate and predictive dispersion modeling being necessary at a later time. The use ofdispersion modeling and receptor modeling in combinationremains the preferred approach when both models are applicable to aparticular circumstance." Memorandumfrom Bauman, Robert D. Chief, SOJParticulate Matter Programs Branch and Joseph A. Tikvart, 

### Chief, Source Receptor Analysis Branch, to Chief, Air Branch, Regions I-X. PM-lO SIP Demonstration for SmallIsolated Areas with Spatially Uniform Emissions. July 5, 1990. (PN 110-90-07-05-106). 6. "The SIP-related emission limits should be based on the NAAQS (annual or 24-hour) which result in the most stringentcontrol requirements. For example, if

### the annual NAAQS requires more stringentcontrol requirements than the 24-hour NAAQS, the annual NAAQS is considered the more restrictive standard and the corresponding emission limit(s) would be adopted
." U.S. Environmental Protection Agency. 

### PM-10 SIP DeveLopment Guideline. Office ofAir 

### QUality Planning and Standards. EPA450/2-86-001. June 1987. pp. 6-1 through 6-8.

8-9 April 1993

### 8.4 CONTROL METHODS FORPM-I0 SOURCES

8.4.1 RACMlBACM Issuance Under section 190 ofthe amended Act, EPA was required to issue technical guidance on reasonably available control measures (RACM) and best available control measures (BACM) for three PM-lO area source categories: (1) urban fugitive dust, (2) residential wood combustion, and (3) prescribed silvicultural and agricultural burning. EPA satisfied its obligation as to the RACM portion ofsuch guidance when it

### published the GeneralPreamble. 

### Specific guidance on RACM for these source categories is provided in appendices Cl, C2, and C3, respectively, to the GeneralPreamble. In 

### addition, section 190 requires EPA to examine other source categories contributing to PM-lO nonattainment, determine ifadditional guidance for RACM and BACM is needed, and issue any such guidance by November 15, 1993. 1



### 8.4.2 RACMlBACM SIP Requirement Under section 189(a)(1)(C) ofthe amended Act, moderate PM-lO nonattainment area SIP's must control PM-lO emissions by providing for the implementation ofRACM. In 

### addition, section 172(c)(1) states that the RACM which nonattainment areaplans must provide be implemented, must include such reductions in emissions from existing sources in 

### the area as may be obtained through the adoption, at a minimum, ofreasonably available control technologies (RACT). Thus, as stated in the GeneralPreamble, 

### together these two provisions require that moderate area PM-lO SIP's include RACM and RACffor existing sources ofPM-IO emissions. 1



### 8.4.3 DeterminingRACMlRACT The suggested starting point for specifying RACM in each SIP is the listing of available control measures for fugitive dust, residential" wood combustion, and prescribed burning including measures selected from among those listed in the appendices to the General Preamble. 

### EPA does not presume that these control measures are reasonably available in any
8-10 

### April 1993 

## t·or all areas; however, EPA expects States to providereasonedjustification for rejection of any measures listed as available in these appendices. Measures determined to be unreasonable because ofinsignificantemtssioMcontribtrtitms from the-soarces affectedmay be excluded fromfurther consideration. Theresulting available control measures should then be evaluated for reasonableness, considering theirtechnological feasibility and the costof control·in the applicable area. Ifa Statereceivespublic comment, in particular circumstances, demonstrating that additional control measures may be reasonably available, such measures should be added to the list ofavailable measures for that area. The RACM is then determined for the affected area's SIP. States should also considerthe feasibility of implementing measures in part when full implementation would be infeasible. When the process ofdetermining RACM is completed, the individual measures should then be converted into a legally enforceable vehicle meeting EPA's criteriaregarding the enforceability ofSIP's and SIPrevisions [see section 172(c)(6) and 110(a)(2)(A) ofthe Act].2 Historically, EPA has defined 

### RACTas "the lowestemission limitation that a particular source is capable ofmeeting by the application ofcontrol technology thatis reasonably available considering technological and economic feasibility." RACT applies to existing sources ofPM-lO stack, process fugitive, and fugitive dust emissions [see section 172(c)(l) ofthe Act]. EPA recommends that, in moderate nonattainment areas, major stationary sources be the minimum starting pointfor RACT analysis. EPA also recommends that available control technology be applied to existing sources that arereasonable to control in light ofthe attainment needs ofthe area and the feasibility ofsuch controls. Thus, RACT analyses for existing stationary sources should not be limited to major stationary sources, but should include other sources in the areathat are reasonable to control given the area's attainment needs.3



### 8.4.4 PM-lO Precursors Primary emissions ofsulfur dioxide, nitrogen oxides, and volatile organic compounds (VOCs) can be converted in the atmosphere to particulate sulfates, nitrates, and organic compounds thatcontribute to PM-lO levels. According to section 189(e) ofthe amended Act, the control requirements applicable under PM-lO SIP's 

### in effectfor major stationary sources ofPM-lO are also applicable to major stationary sources ofPM-lOprecursors, except where the EPA determines that such sources do not contribute significantly to PM-lO levels which
8-11 April 1993exceed the PM-10NAAQS in the area. Thus, for example, because moderate PM-lO nonattainment area SIP's should contain RACffor major stationary sources ofPM-lO, they should also contain RACffor major stationary somces ofPM-lOprecwsOls, mtless-EPA
. . determines otherwise. EPA intends to make a formal determination ofwhethermajor stationary sources ofPM-lOprecursors contribute significantly to PM-lO levels in aparticular are. a when EPA takes rulemaking action onindividual moderate area SIP's. The discussion in the 

### GeneralPreamble is intended to provide initial guidance for controlling PM-lOprecursors for major stationary sources in PM-lO moderate nonattainment areas. This guidance does not preclude any specific findings made by EPA based on its review ofindividual PM-IO nonattainment area SIP'S.4
In the western United States, EPA generally believes that sources ofsulfur dioxide and nitrogen oxides may contribute to PM-lO exceedances in several major metropolitan areas, but are not as likely to be significant contributors to the nonattainmentproblemin other western areas. IfEPA determines that major stationary sources ofS02and 

### NOx in western areas do not contribute significantly to exceedances ofthe PM-lO NAAQS, such sources would not be expected to meet the control requirements (e.g., RACT) applicable to major stationary sources ofPM-lO. This detennination will bebased on information contained in the SIP submittals, and on any other additional available information States may provide. In making its detennination, EPA will consider the presence offactors which enhance the likelihood ofsecondary particulate formation, such as source mix and density, nonattainment area size, meteorology and topography.4
In the eastern United States, pollutant transp.ort between airsheds can beresponsible for a large portion of secondary particle concentrations in nonattainment areas. Under these circumstances, determining whether PM-I0 precursor sources in a nonattainment area contribute significantly to PM-lO concentrations in the same area is more difficult. In all cases, as stated earlier, EPA will detennine the applicability of section 189(e) based on all available technical information including any information provided by States in their individual SIP submittals. EPA will assess the reasonableness ofeach SIP submittal inpart by considering the fact
.thatregionwide reductions in precursor emissions are expected to result from the implementation ofotherprovisions ofthe Act. These reductions may mitigate precursor contributions to PM-lO concentrations.4



### 8-12 April 1993EPA will considerthe infonnation submittedby States containing major stationary sources ofVOCs in PM-tOnonattainment areas to determine ifVOC emissions from such sources contribute significantly to exceedances ofthe ambient standard. EPA willassess the reasonableness ofthe submission when reviewing a SIP submittalcontaining a request for an exemption from PM-tO precursor controls because ofVOCreductions obtained from implementing other control requirements ofthe amended Act.4



### 8.4.5 Condensible PM-lO Condensible particulate matter (CPM) is particulate matter that forms in the atmosphere as exhaust gases from a source cool. CPM emissions form particles in the PM-tO size range and are considered cool PM-tO emissions.5 EPA believes that it is reasonable (and therefore constitutes RACT) to control CPM only where CPM comprises a significant proportion ofthe emissions from an existing stationary source.5 A list of sources suspected ofemitting significant amounts ofcondensible material is providedin the

### PM-IO SIP Development Guideline.6



### 8.4.6 Control Measures Available for Fugitive Dust RACM Fugitive dust is particulate matter suspendedin the aireither by mechanical disturbance or by blowing wind. EPA policy is to reduce fugitive dust emissions using preventive measures ratherthan mitigative measures. Available control measures are listed in Appendix C 1ofthe GeneralPreamble and include the following.7

1. Pave, vegetate, orchemically stabilize access points where unpaved traffic surfaces adjoin pavedroads and unpavedparking areas. 2. Require dust control plans for construction or land clearing projects.
3. Require haul trucks to be covered. 4. Provide for traffic rerouting orrapid cleaning oftemporary sources ofdust onpaved roads.
8-13 April 19935. Require paving or stabilizing ofpermanentunpaved haulroads, andparking or staging areas atcommercial, municipal, or industrial facilities. 

### 6. Develop traffic reductionplansfor unpavedroads and apply measures to encourage the use ofpavedroads.
7. Limituse ofrecreational vehicles on open land. 

### 8. Require improved material specification for and reduction ofusage of skid control sand or salt 9. Require curbing and pave or stabilize**s~oulders** ofpavedroads. 

### 10. Pave or chemically stabilize unpaved roads. 11. Establish dustcontrol measures ofmaterial storage piles. 12. Provide for storm water drainage to prevent water erosion into paved roads. 

### 13. Require vegetation, chemical stabilization, or other abatement ofwinderodible soil, including lands subjected to water mining, abandoned farms, and abandoned construction sites. 14. Rely upon the soil conservationrequirements ofthe Food Security Actto reduce emissions from agriCUltural operations. These measures apply to all fugitive dust sources except those associated with stationary sources where RACT is applicable. Technical guidance on fugitive dust control measures is found in 

### Control ofOpen Fugitive DustSources. 8



### 8.4.7 Control Measures Availablefor Residential Wood Combustion RACM
Wood smoke from residential wood combustion (RWC) is a significant source of PM-lO in some PM-lO nonattainment areas in the western United States. EPA has provided a
8-14 April 1993new sourceperformance standard for RWC (53 FR 5860, February 26, 1988) to improve the performance ofwood burning devices nationwide. EPA does not believe, however, that this standard alone will resultin attainment ofthe PM-IO standards 

### inareas affectedbywood smoke.9 Therefore, additional control measures were identified and are listed in Appendix C2 ofthe GeneralPreamble. Theseinclude the following:9
1. Establish an episode curtailmentprogram. 2. Establish apublic information program. 3. Encourage improved performance ofwood burning devices by:

• Establishing a program to identify, through opacity observation, deficiencies in stove operation and maintenance.
• Providingvoluntary dryness certification for wood moisture.
• Evaluating and encouraging the accelerated changeover ofexisting devices to the new source performance standard orother clean burning stoves. 4. Provide inducements that would lead to reductions in the stove and fireplace population (or use) by:

• Slowing the growth ofwoodburning devices in new housing units.
• Encouraging a reduction in the number ofwoodburning devices.
• Discouraging the resale ofused stoves.
• Discouraging the availability offree (or very inexpensive) firewood. Additional guidance on control measures for residential wood combustion is contained in GuidanceDocumentforResidential Wood Combustion ControlMeasures. lO

8-15 April 1993

### 8.4.8 Control Measures Available for Prescribed BurningRACM
Forthe purpose ofPM-I0 SIPdevelopment, prescribed burning consists ofall open burning ofvegetative matter, including silvicultural and agricultural burning. This includes planned ignitions, and prescribed natural fire. Prescribed burning contributes to PM-lO nonattainment in some regions ofthe United States.ll
EPA believes that States should establish a smoke management (SM) program which will constitute RACM. Such programs should reduce population exposure to smoke from prescribed burning, while assuring thatresource management goals are met Nothing in a smokemanagement program constituting RACM is intended to influence vegetation management or fire suppression practices so as to increase the potential for wildfire to the point that natural resources orpublic safety are compromised. ll
EPA believes thatitis reasonable to apply a SM program in those moderate PM-lO nonattainment areas where it has been shown, through monitoring, modeling, or other analysis, thatprescribed burning can or does contribute to exceedances ofthe PM-lO NAAQS. The smoke managementprogram should also apply to those areas outside ofthe nonattainment area if

### itis shown thatprescribed burning outside ofthe nonattainment area can or does contribute to the exceedances. The prescribed burning RACM may be limited only to the season(s) when PM-lO exceedances occur ifitcan be shown that the annual PM10 NAAQS is not violated. In addition, it may not be reasonable to control certain source categories with 

### de minimis impact based on consideration oftheir collective influence on PM-lO emissions, duration, season, and proximity to affected populations.ll Appendix C3 ofthe 

### GeneralPreamble discusses the control measures available for prescribed burning.ll An SM program should consist ofatleast the following components:



### 1. Smoke dispersion evaluation. The program should use meteorological analyses to determine when meteorological conditions are favorable or unfavorable for burning. 2. Burn

### planning authorization andadministration. The smoke management program should provide a process 

### (e.g., telephone call-in) for receiving burn requests, evaluatingrequests and granting approval ofburns.

8-16 April 1993 

## I::

### 3. Requirementsfor ensuring burnerqualifications. Voluntary training in smoke managementtechniques should bereasonably available for all burners. 

### 4. Public education andawareness. Information programs on the nature ofand reasons for smokemanagement should beperiodicallypresented to the public. 

### 5. Surveillance andenforcement. The SM program should rely on routinePM-lO monitoring, and/or modeling supplemented byperiodic visual assessments ofthe effectiveness ofthe dispersion evaluationprogram. 

### 6. Emission inventories and emission ejfons. States should develop and maintain an emission inventory for prescribed burning and all burns should be categorized as to their purpose. 

### 7. State oversight. The relationship ofthe State airpollution agency with other State agencies to which management ofthe SM program may have been delegated will need to be determined on a State-by-State basis.



### 8.4.9 RACT Determination for Stationary Sources
The amended Actrequires RACTfor PM-lO nonattainment area SIP's. Appendix C4 ofthe 

### GeneralPreamble discusses RACTdeterminations for stationary sources. The EPA recommends thatRACTfor a particular source be determined on a case-by-case basis depending on both the technological and economic feasibility ofreducing emissions from that source. Control may be implemented through process changes or through add-on control technology. The technological feasibility ofapplying an emission reduction should consider the source's process and operating procedures, raw materials, physicalplantlayout, and any other environmental impacts such as waterpollution, waste disposal, and energy requirements. Analysis ofeconomic feasibility should include the costofreducing emissions and the cost differential between the particular source and other similar sources that have implemented emission reductions. 12

.

8-17 April 1993Alternative approaches to reducing emissions ofPM-IO are discussed in 

### Control TechniquesforParticulate Emissionsfrom Stationary Sources

- VolumeIand Volume II.13·I4 Additional sources ofinfonnation on control technology are backgroundinfonnation documents for new source perfonnance standards and

### Identification,Assessment, and Control of Fugitive ParticulateEmissions. Is

8-18 April '1993

### REFERENCES FORSECTION 8.4

1. 

### 57 Federal Register, 13,540 (April 16, 1992), General Preamble for the Implementation ofTitleI ofthe Clean Air

### Act Amendments of 1990; Proposed Rule; SIP Requirements; Particulate Matter; Statutory Background; RACM/RACf. 2. 57 Federal Register, 13,540 (April 16, 1992), General Preamble for the Implementation ofTitle I ofthe Clean Air

### Act Amendments of 1990; Proposed Rule; SIPRequirements; Particulate Matter; Determination ofRACM/RACf; RACM. 3. 57 Federal Register, 13,541 (April 16, 1992), General Preamble for the Implementation ofTitleI ofthe Clean Air Act Amendments of 1990; Proposed Rule; SIPRequirements; Particulate Matter; Determination ofRACM/RACf; RACf. 4. 57 Federal Register, 13,541-2 (April 16, 1992), General Preamble for the Implementation ofTitle I ofthe Clean Air Act Amendments of 1990; Proposed Rule; SIP Requirements; Particulate Matter; Determination ofRACMlRACf; PM-1O Precursors. 5. 57 Federal Register, 13,542-3 (April 16, 1992), General Preamble for the Implementation ofTitle I ofthe Clean Air Act Amendments of 1990; Proposed Rule; SIP Requirements; Particulate Matter; Determination ofRACMlRACf; Condensible PM-IO. 6. U.S. Environmental Protection Agency, PM-10 SIP Development Guideline, 

### EPA450/2-86-001, Research Triangle Park, NC, June 1987. P.5-33. 7. 57 Federal Register, 18,072 (April 28, 1992), General Preamble for the Implementation ofTitle I ofthe Clean Air

### Act Amendments of 1990; Supplemental; Proposed Rule; Appendix Cl

- Available Fugitive Dust Control Measures. 8. U.S. Environmental Protection Agency, Control ofOpen FugitiveDustSources. 

### EPA450/3-88-008, Research Triangle Park, NC, September 1988. 9. 57 Federal Register, 18,072 (April 28, 1992), General Preamble for the Implementation ofTitle I ofthe Clean Air Act Amendments of 1990; Supplemental; Proposed Rule; Appendix C2

- Available Residential Wood Combustion Control Measures
. 10. U.S. Environmental Protection Agency, Guideline Series

- GuidanceDocumentfor Residential Wood Combustion Emission ControlMeasures, 

### EPA-450/2-89-015, Research Triangle Park, NC, September 1989.

8-19 April 199311. 57 Federal Register, 18,072-3 (April 28, 1992), General Preamble for the Iniplementation ofTitle I ofthe Clean Air ActAmendments of 1990; Supplemental; Proposed Rule; Appendix C3

- Prescribed Burning Control Measures. 12. 57 Federal Register, 18,073-4 (April 28, 1992), General Preamblefor the Implementation ofTitle I ofthe Clean AirAct Amendments of 1990; Supplemental; Proposed Rule; Appendix C4

- RACT Determinationsfor Stationary Sources. 13. U.S. Environmental Protection Agency, Control Techniquesfor Particulate Emissions from Stationary Sources

- Volume I. EPA 450/3-81-005a. Research Triangle Park, NC, September 1982. 14. U.S. Environmental Protection Agency, Control TechniquesforParticulate Emissions from Stationary Sources

- Volume II. EPA 450/3-81-005b. Research Triangle Park, NC, September 1982. 

### 15. U.S. Environmental Protection Agency, Identification, Assessment, and Control of Fugitive ParticuLate Emissions. EPA 600/8-86-023. Research TrianglePark, NC, August 1986.

8-20 April 1993

### 9.0 GENERAL PROVISIONS

9.1 GENERAL NAAQS are established at a level to protect the public health and welfare. 

### On July 1, 1987, EPA revised the NAAQS forparticulate matter, replacing TSP as the indicatorfor particulate matter with a new indicator that included only thoseparticles with an aerodynamic diameter less than or equal to a nominal 10 micrometers (called PM·lO).l The amount of time that areas are given to reach the NAAQS depends on whether the standard is a primary standard (health based) or'a secondary standard (welfare based).2.3 The PSD increments are setto preventrelative deterioration in air quality for different classes. SIP's and SIP revisions provide for the implementation, maintenance, and enforcement ofmeasures needed to attain and maintain the NAAQS. Ifthe provisions in a SIP are found to be substantially inadequate, a SIPcall may be issued by the U
.S. EPA.

9-1 April 1993

### REFERENCES FOR SECTION9.1

1. 

### 52 Federal Register 24,634 (July 1, 1987), Revisions to the National Ambient Air Quality Standards for Particulate Matter. 2. U.S. Congress. Clean Air Act, as amended November 1990. 42 U.S.C. 7401 

### et. seq. Section 109. Washington, D.C
. U.S. GovernmentPrinting Office. 3
. U.S. Congress
. Clean Air Act, as amended November 1990. 42 U.S.C. 7401 

### et. seq. Section IIO(a). Washington, D.C. U.S. Government Printing Office.

9-2 April 1993

### 9.2 CLEAN AIR ACT REQUIREMENTS: TIME FRAMES AND PM·I0NAAQS SIP REQUIREMENTS

9.2.1 Designations On the date the Clean Air ActAmendments were enacted, (November 15, 1990), by operation oflaw PM-lO areas were designated as either nonattainment orunclassifiable. Areas meeting the qualifications of section 107(d)(4)(B) were designated nonattainment. These areas included all former Group I areas identified in 52 FR 29383 (August7, 1987) and 55 FR45799 (October 31, 1990) and other areas violating the PM-lO NAAQS prior to January 1, 1989. All other areas were designated unclassifiable. A Federal Registernotice announcing all ofthe areas designated nonattainmentfor PM-IO at enactment ofthe amended Act and classified as moderate was published in 56 FR 11101 (March 15, 1991). A subsequentnotice correcting certaininformation in the March 15, 1991 notice was published in 56 FR 37654 (August 8, 1991). The amended Act allows EPA to redesignate any ofthe areas designated unclassifiable to nonattainment in accordance with section 107(d)(3), after the date ofenactment. On April 22, 1991 EPA announced in 56 

### FR 16274 that ithad initiated the redesignation process for 16 areas. 1



### 9.2.2 Classification Section 188 ofthe amended Actoutlines the process for classification ofareas designated nonattainment and establishes the corresponding attainment date. In accordance with section 188(a), all PM-lO nonattainment areas are initially classified as moderate. If, at any time before the applicable attainmentdate, EPA determines that a moderate area cannot "practicably"**at~** the PM-lO NAAQS by the Act deadline, the area may be reclassified as serious. A moderate area may also be reclassified as serious after the passage ofthe moderate area attainment date ifEPA determines that the area has failed to attain the standard. EPA's decisions to reclassify areas will be based on facts specific to each area underreview. EPA mustprovide notices in the Federal Register and an opportunity for public comment before making reclassification decisions. EPA believes its policy of reclassification creates an incentivefor the timely submittal and effective implementation of moderate area SIP requirements and facilitates the PM-lO attainment objective.2
9-3 April 1993

### 9.2.3 AttainmentDates The GeneralPreamble 

### addresses only the control measures recommended for moderate PM-lO nonattainrnent areas. As such, the following discussion is limited to the attainment dates for moderate nonattainrnent areas. Section 188(c)(I) ofthe amended Act specifies that moderate nonattainrnent areas designated nonattainrnentupon enactment (initial moderate nonattainrnent areas) are to attain the PM-lO NAAQS as expeditiously as practicable, butno later than December 31, 1994, unless they are reclassified as serious. Those areas designated nonattainrnent subsequent to enactment and classified as moderate must attain the PM-lO NAAQS as expeditiously as practicable, but no later than the end of the sixth calendaryear after the area's designation as nonattainment.2 

### Under section 188(d) ofthe Act, the attainment date for a moderate area may be extended for 1year provided that the State has fully complied with the applicable SIP, no more than one exceedance ofthe 24- hour PM-10 standard has occurred in the year preceding the extension year, and the annual mean PM-IO concentration is less than or equal to the annual PM-lO standard. For an area, no more than two such extensions may be granted by EPA. Formoderate areas designated nonattainment by operation oflaw upon enactment of the amended Act and subsequently determined by EPA to 

### be unable to "practicably" attain the NAAQS by December 31, 1994, the amended Act specifies certain dates by which EPA must propose to reclassify those areas as serious and take final action. Those areas designated nonattainment after enactment, must be reclassified as serious within 18 months after the required submittal date for the moderate area SIP. Taken together with the requirement that a SIP be submitted 18 months after an area is designated nonattainment, EPA is required to reclassify an appropriate moderate area as serious within 3 years ofthe nonattainment designation.2



### 9.2.3.1 Attainmentdatewaiver Under section 188(f) ofthe amended Act, EPA has the authority to waive specific attainment dates for moderate PM-lO nonattainment areas where nonanthropogenic sources contribute significantly to the violation ofthe PM-lO NAAQS. The attainment date may be waived, however, only for areas thatfully implement their moderate area SIP requirements.
9-4 April 1993

### As aresult, any State requesting an attainment date waiver should nevertheless proceed with SIP development and implementation. Nonanthropogenic sources include only those emissions where the human role is slight ornonexistent. EPA will be issuing additional guidance on the scope ofthe waiverprovision as it

### applies to both moderate and serious PM-lO nonattainment areas.3

.


### 9.2.3.2 International borderareas Under section 179B ofthe amended Act, a SIP for a moderate PM-lO nonattainment area affected by emissions from sources located outside the United States may be approved by EPA, although it fails to demonstrate attainment by the applicable date, provided the plan meets all other applicable requirements ofthe Act. The State must satisfy EPA that the SIP would be adequate to attain by the applicable date, except for emissions originating outside the United States. The SIP must also meet all ofthe applicable requirements (e.g., 

### RACMJRACT) under the Act. In general, EPA expects that such areas will be adjacentto international borders.4



### 9.2.4 Plan Submission States must develop and submit SIP's providing for the attainment ofthe PM-lO NAAQS for every area designated as nonattainment and classified as moderate for PM-lO under the amended Act. For initial moderate PM-lO areas (designated nonattainment upon enactment), section 189(a)(2) ofthe amended Act requires States to submit a SIP revision (e.g., 

### including RACMJRACT and an attainment demonstration) by November 15, 1992. The NSR program provisions for these areas were due June 30, 1992. ForPM-lO areas designated nonattainment after enactment ofthe Act, States are required to submit SIP's within 18 months ofthe date ofdesignation. Specific requirements applicable to moderate nonattainment areas include the requirement that SIP's provide for an NSR permit program; an attainment demonstration (or a demonstration that attainment is impracticable); RFP/quantitative milestones; the control ofPM-lO precursors; RACM/RACT; and contingency measures. These requirements are discussed below.5



### 9-5 April 1993

### 9.2.4.1 NSR permitprogram Section 189(a)(l) ofthe amende<tACLrequires States with moderate PM-lO nonattainment areas to meetthe requirements ofsection 172(c)(5) by submitting an implementation plan containing a permitprogrammeeting therequirements of section 173 for the construction and operation ofnew and modified major stationary sources ofPM-lO (and, in some cases, PM-lO precursors). For initial moderate PM-lO areas designated nonattainmentupon enactment, States must submit a SIPrevision to EPA containing the NSR programprovisions for these areas by June 30, 1992. ForPM-lO areas designated nonattainment after enactment ofthe Act, States are required to submit SIP's containing the NSRprogramwithin 18 months after designation ofeach affected area.6
Section 10.2.6 ofthis guideline provides additional information on NSRpermit programrequirements under the amended Act.



### 9.2.4.2 Attainment demonstration
States with moderate PM-lO nonattainment areas are required under section 189(a)(l)(B) ofthe amended Act to submit a demonstration showing attainment by the applicable attainmentdate. Such demonstrations mustinclude air quality modeling. Alternatively, the State may show that attainmentby the applicable date is impracticable. A SIP submittal demonstrating attainment mustcontain a comprehensive, accurate, current inventory ofactual emissions from all sources ofPM-10 in the area as established in section 172(c)(3).7 Modeling guidelines to be followed in the demonstration ofattainmentfor the initial moderate PM-lO nonattainment areas include PM-IO SIP Development Guideline (June 1987); Guideline onAir QualityModels (Revised); a memorandumfrom Tikvart and Bauman titled PM-IO SIP Demonstration/or SmallIsolatedAreas with Spatially Uniform Emissions (July 5, 1990); and any applicableregulatory requirements. In addition, Appendix C5 ofthe General Preamble provides EPA's supplemental attainment demonstration policy that may be followed in some special circumstances. Formoderate areas designated after enactment ofthe amended Act, the attainment demonstration will be reviewed in accordance with the general guidelines cited above and any other applicable EPA guidance orregulations. The
9-6 April 1993**suppleme~tal** policyprovided in Appendix C5 ofthe GeneralPreamble will not apply to these areas.7



### 9.2.4.3 Reasonable further progress States must submitPM-lO nonattainment area SIP's which include quantitative emissionsreductions milestones to be achieved every 3 years until an area isredesignated attainment. Thesemilestones should demonstrate RFP as described under section 171(1). States mustdemonstrate to EPA that the SIP measures are being implemented and the milestones have been metwithin 90 days afterthe milestone due date. Itis then EPA's responsibility to determine whether the State's demonstration is adequate within 90 days of receiving the demonstration. Ifa State fails to submitthe quantitative milestone demonstration, orEPA determines that a milestone was notmet, the State isrequired to submit a SIPrevision due within 9 months ofeither the missed reporting date or EPA's determination that a milestone was missed. The SIPrevision must also ensure that the next milestone will be achieved by the applicable date and/or the PM-lO attainmentdate will be met ifthere are no additional milestones.8
Section 189(c) does notdefine the starting pointfor counting the 3-yearperiod for RFP milestones. EPA's position concerning this issue is provided in the GeneralPreambLe. The first quantitative milestone deadline for initial PM-lO moderate nonattainment areas is November 15, 1994.8
Note that the December 31, 1994 attainment date is only 46 days after the November 15, 1994 milestone deadline. Therefore, EPA's policyfor initial PM-lO moderate nonattainment areas is that the emissions reductionsprogress made between the SIP submittal due date (November 15, 1991) and the attainment date (December 31, 1994) will satisfy the first quantitative milestone. This policy was adopted because itis administratively impracticable to require separate milestone and attainment demonstrations within such a narrow timeframe. EPA is required to determine whether a nonattainment area has attained the standards within 6 months after the applicable attainmentdate under sections 179(c) and 188(b)(2) ofthe Act. Therefore, consistent with the milestone requirement, within 90 days
9-7 April 1993after the December 31, 1994 attainment date, States must demonstrate that the SIP has been implemented and the area has attained the standards or, alternatively, qualifies for a I-year extension ofthe attainment date under section 188(d) ofthe ActS EPA plans to issue future guidance on the RFP/quantitative milestonerequirements for those areas designated moderate PM-lO nonattainment after enactment ofthe amended Act.s

9.2.4.4 

### PM-IO precursors Section 189(e) ofthe Actprovides that the applicable controlrequirements underPM10 nonattainment area SIP'sin effectfor major stationary sources ofPM-lO are also applicable to major stationary sources ofPM-lO precursors, except where EPA determines that the sources ofPM-lO precursors do not contribute significantly to PM-lO levels which exceed the PM-lO NAAQS in the area. In general, EPA's determination will be based upon air quality analysis in which States assess the contribution ofprecursors. Ifprecursors do contribute to nonattainment, States must consider both the source-receptorrelationship and the significance ofprecursor contributions to overall nonattainment.9 Section 8.4.4 ofthis guideline discusses EPA's initial guidance for controlling PM-lO precursors for major stationary sources in moderate PM-lO nonattainment areas. In determining the significance ofand the need to control precursors in a specific area, EPA will rely in part on the technical information contained in the State's submittal. This information includes, butis notlimited to, filter analysis, the relative contribution of precursors to overall nonattainment, and the State's RACT/RACM strategy. EPA encourages the States to submit additional material for consideration. All findings will be made·on a case-by-case basis due to the different conditions present among the various nonattainment areas. EPA has provided initial guidance for controlling PM-lO precursors for major stationary sources in moderate PM-lO nonattainment areas in the General Preamble. EPA intends to provide additional guidance, ifnecessary, on control requirements for major stationary sources ofPM-lO precursors when itissues proposed regulations for the NSR permitprogram applicable to PM-lO nonattainment areas, and when it issues guidance on control technology requirements applicable to major stationary sources 

### in serious PM-IO nonattainment areas.9

9-8 April 1993

### 9.2.4.5 RACMlRACT Section 189(a)(l)(C) ofthe amended Actrequires that moderate area SIP's include RACM for the control ofPM-1O emissions. Section 172(c)(l) ofthe amended Act requires that RACM for nonattainment areas include "suchreductions in emissions from existing sources in the area as may be obtained through the adoption, at a minimum, ofreasonably available control technology
... " Together these two provisions require that moderate area PM-I0 SIP's include RACM and RACT for existing sources ofPM-1O emissions.1O
Under section 189(a)(I) ofthe amended Act, initial moderate PM-1O nonattainment areas must submit SIP's containing RACM/RACT control measures by November 15, 1991. These SIP's must provide for the implementation ofRACM/RACT no later than December 10, 1993. Under section 189(a)(2)(B), areas designated nonattainment and classified as moderate after enactment must submit SIP's containing RACM/RACT control measures 18 months after the nonattainment designation. Under section 189(a)(1)(C), these SIP's must provide for the implementation ofRACM/RACT no later than 4 years after designation, which is 30 months after the applicable SIP submittal deadline.1O



### 9.2.4.6 Contingency measures As provided in section 172(c)(a) ofthe amended Act, all moderate PM-1O nonattainment area SIP's must include contingency measures. Contingency measures are measures that become effective without further action by the State orEPA, upon determination by EPA that the area has failed to make RFP or to attain the PM-1O NAAQS by the statutory deadline. Contingency measures should consist ofavailable control measures not included in the primary control strategy.11 Under section 172(b), the Administrator ofEPA sets a schedule (not to extend 3 years from the affected areas' nonattainment designation) for when the provisions required under section 172(c) must be submitted. The Administrator has not set a schedule for when contingency measures are due for the initial moderate PM-lO nonattainment areas and, therefore, States are not obligated to submit contingency measures. EPA has provided guidelines in a February 25, 1992 memorandum on the contingency measure due date for the

9-9 April 1993initial moderate PM-lO nonattainment areas. Among other things, guidance also addresses how EPA may treat contingency measure States have already submitted
.12

9-10 April 1993

### REFERENCES FORSECTION 9.2
1. 57 Federal Register 13,573 (April 16, 1992), General Preamble-for the-lmplementation ofTitle I ofthe Clean Air Act Amendments of 1990; Proposed Rule; SIP Requirements; Particulate Matter; StatutoryBackground; Designations. 2. 57 Federal Register l3,537 (April 16, 1992), General Preamble for the Implementation ofTitle I ofthe Clean AirAct Amendments of 1990; Proposed Rule; SIP Requirements;
.Particulate Matter; StatutoryBackground; Classifications and AttainmentDates. 3. 57 Federal Register 13,544-5 (April 16, 1992), General Preamble for the Implementation ofTitle I ofthe Clean AirAct Amendments of 1990; Proposed Rule; SIPRequirements; Particulate Matter; SIP's ThatDo Not Demonstrate Attainment; AttainmentDate Waiver Nonanthropogenic Sources. 4. 57 Federal Register 13,545 (April 16, 1992), General Preamble for the Implementation ofTitle I ofthe Clean Air Act Amendments of 1990; Proposed Rule; SIP Requirements; Particulate Matter; SIP's ThatDo Not Demonstrate Attainment; International Border Areas. 5. 57 Federal Register l3,538 (April 16, 1992), General Preamble for the Implementation ofTitle I ofthe Clean Air Act Amendments of 1990; Proposed Rule; SIP Requirements; Particulate Matter; Statutory Background; General SIP Requirements. 6. 57 Federal Register 13,538 (April 16, 1992), General Preamble for the Implementation ofTitle I ofthe Clean Air Act Amendments of 1990; Proposed Rule; SIP Requirements; Particulate Matter; Statutory Background; NSR PermitProgram. 7. 57 Federal Register 13,538-9 (April 16, 1992), General Preamble for the Implementation ofTitle I ofthe Clean Air Act Amendments of 1990; Proposed Rule; SIPRequirements; Particulate Matter; StatutoryBackground; Attainment Demonstration. 8. 57 Federal Register l3,539 (April 16, 1992), General Preamble for the Implementation ofTitle I ofthe Clean Air Act Amendments of 1990; Proposed Rule; SIP Requirements; Particulate Matter; StatutoryBackground; RFP/Quantitative Milestones. 9. 57 Federal Register 13,539-40 (April 16, 1992), General Preamble for the Implementation ofTitle I ofthe Clean AirActAmendments of 1990; Proposed Rule; SIPRequirements; Particulate Matter; Statutory Background; PM-1O Precursors. 10. 57 Federal Register 13,539-40 (April 16, 1992), General Preamble for the Implementation ofTitle I ofthe Clean Air Act Amendments of 1990; Proposed Rule; SIP Requirements; Particulate Matter; Statutory Background; RACM/RACT. 9-11 April 199311. 57 Federal Register 13,543-4 (April 16, 1992), General Preamble for the Implementation ofTitle I ofthe Clean 

### Air Act Amendments of 1990; Proposed Rule; SIPRequirements; Particulate Matter; SIP's That Demonstrate Attainment. 12.
.. However, the Administratorhas not seta schedule for the PM-lO contingency measure submittal. The August 1991 guidance was notissued bythe Administrator. Therefore, until the Administrator establishes the due date, States are not obligated to submitcontingency measures." Memorandum. John Calcagni, Director, Air Quality Management Division, Office of

### Air Quality Planning and**Standards~** 

### U.S. EnvironmentalProtection Agency, Research Triangle Park, 

### NC, to Director, Air Pesticides and Toxics ManagementDivision, Region 

### I and 

### IV; Director, Air and Waste Management Division, Region II; Director, Air, Radiation and Toxics Division, Region

### ill; Director, Air and Radiation Division; Director, Air, Pesticides, and Toxics Division VI; and Director, Air and Toxics Division, Regions

## vn, VllI, IX, and X. 

### Contingency Measure DueDateforInitialPM-IO ModerateNonattainmentAreas. February 25, 1992.

9-12 April 1993

### 9.3 CURRENT NAAQS AND PSD PROGRAM

9.3.1 National AmbientAir Quality Standards The EPA is required, under section 109 ofthe Act, to establish NAAQS for each pollutantfor which air quality criteria are established (under Section 108 ofthe Act). There are two types ofNAAQS: primary and secondary. The primary NAAQS are established to protectpublic health with an adequate margin ofsafety. The secondary NAAQS protect public welfare (soil, crops, vegetation, animals, visibility, building materials,etc.) from known or anticipated effects. ForPM-lO, the primary and secondary NAAQS are the same. The current PM-IO NAAQS is 50 pg/m3 based on an expected annual arithmetic mean and 150 pg/m3 based on the expected maximum 24-hour concentration not to be exceeded more than once per year.l



### 9.3.2 Prevention ofSignificant Deterioration Program Part C ofTitle I ofthe Act (sections 160-169) establishes the basis for the PSD program. The PSD regulations apply in section 107 areas designated as attainment or uncIassifiable. Each applicable SIP mustcontain emission limitations and other measures as needed to prevent significant deterioration ofair quality in such areas. The PSD permittingprogramis intended to balance three primary goals. The first of these goals is to protectpublic health and welfare. This goal includes avoiding air quality degradation in all areas that are attaining the NAAQS. The second goal emphasizes the protection ofair quality in national parks, wilderness areas, and similar areas ofspecial concern where air quality is considered particularly important The third goal is to ensure that economic growth which causes environmental degradation in clean areas occurs only after careful deliberation by State and local communities. The PSD regulations require that "major" new stationary sources and "major" modifications be carefully reviewed prior to construction to ensure compliance with the NAAQS, the applicable PSD air increments, and the requirement to apply best available control technology (BACT) to minimize the project's emissions ofairpollutants.


### 9-13 April 1993The PSD permittingprogramrequirements become effective when the net emissions increase for any pollutant emitted by a source is "significant."z The significance threshold established forparticulate matter is 25 tpy oftotal particulate matter emissions and 15tpyaf PM-1O emissions.3 Ifa source is subject to PSDreview, then PSDreview will be applied to eachpollutantthe source emitsin greater than de minimis amounts, unless the area is designated a nonattainment. The PSD programisimplemented through the use ofambient 

### air quality increments and area classifications that effectively define "significantdeterioration" in a given area for individual pollutants. Air quality increments are the maximum allowable increase in ambient air concentration above a baseline concentration. Note that emissions from all sources within the area, including minor sources, are considered for the purpose ofestablishing increments. The area classifications establish three classes ofgeographical areas. Class I areas are regions ofspecial national environmental concern such as national parks
. Class IT areas are PSD areas not identified in the Act as Class I areas. There are currently no Class illareas. Table 9-1 shows the current PSD increments for particulate matter.4


### TABLE 9-1. CURRENT PSD INCREMENTS FORPM MEASURED AS TSP Class I IT 

### ill 

### MaximumAllowable Increase (pg/m3) 5 

### 10 19 37 37 75 (TSP, annual geometric mean) (TSP, 24-hour maximum) (TSP, annual geometric mean) (TSP, 24-hour maximum) (TSP, annual geometric mean) (TSP, 24-hour maximum)

9-14 April 1993

### REFERENCES FOR SECTION 9.3
1. U.S. Environmental Protection Agency. Code of FederalRegulations. 

### Title 40, ChapterI. Subchapter C, Part 50.6. July 1, 1991. 2. U.S. Environmental Protection Agency. Code of FederalRegulations. 

### Title 40, Chapter 1. 

### Subchapter C, Part 51.166(b)(2)(i). July 1, 1991. 3. U.S. Environmental Protection Agency. Code of FederalRegulations. 

### Title 40, Chapter 

### 1. Subchapter C, Part 51.166(b)(23)(i). July 1, 1991. 4. U.S. Congress. Clean Air Act, as amended November 1990. 42 U.S.C 7401 

### et. seq. Section 163(b). Washington, D.C. U.S. Government Printing Office.

9-15 April 1993

### 9.4 SIPREVISIONS

9.4.1 General All SIP revisions mustinclude a demonstration that the NAAQS and PSD increments are not violated in the area. Specific requirements for SIP processing are contained in 

### Guidelinesfor theReview ofSIPRevisions

### by EPA Regional Offices. l



### 9.4.2 SIP Completeness In accordance with the requirements ofsection 11O(k)(I) ofthe amended Act, EPA has promulgated minimum completeness criteria that any SIP submittal must meet [see 56 FR 23826 and 56 FR 42216]. The minimum completeness criteria serve as a tool for EPA to assess whether a SIP submittal is complete and, therefore, adequate to trigger an EPA review and action on the submittal. The completeness criteria provide criteria and procedures that can be used by States to prepare adequate SIP submittals.2
Two categories ofcriteria have been developed in order to determine whether a submittal by a State is complete: (1) administrative information and (2) technical support information. Administrative information includes the documentation necessary to demonstrate that the State has adhered to basic administrative procedures during the rule adoption process. Technical supportinformation includes the documentation that adequately identifies all ofthe required technical components ofthe plan submission. Ifa submittal is determined to be complete, EPA will inform the State by letter ofits determination and then begin the formal review for approvability. If a submittal is determined to be incomplete, EPA will return it to the State with a letter listing the deficiencies. EPA will attempt to make completeness determinations within 60**d~ys** ofreceiving a submittal in accordance with section 11O(k)(1)(B) ofthe amended Act. However, ifa completeness determination is not made by EPA within 6 months ofits receipt ofthe submittal, the submittal will be deemed complete.2

9-16 April 1993

### 9.4.3 Approval Options In theprocessing



### - 0£ SIP 

### subntitr.:ds; thereare three generalsituations thatcan occur related to each required submittal: (1) the State may fail to submitthe required plan; (2) 

### the State may make a submittal thatis deemed incomplete; or (3) the State may make a complete submittal. If

### the State fails to make a required submittal ormakes a submittal thatis determined by EPA to be incomplete, the sanctions and FIPprovisions ofsections 179 and 11O(c) willbe triggered. (The sanctions and 

### PIP provisions ofthe Act are discussed in section 

### 9.5 ofthis guideline.) If

### EPA determines that a submittal is complete, itmust either approve ordisapprove the submittal within a certain period oftime.3 

### However, in some instances a State's complete SIP submission may include provisions that do notcomply with applicablerequirements ofthe Act. In 

### those instances, EPA may issue apartial approval, a limited approval, or 

### a conditional approvaL4• S 

### Section 110(k)(3) ofthe amended Act addresses the situation in which a separable portion ofa submittal meets all applicable requirements ofthe Act. If

### the disapproved portions ofa SIP submittal are separable (i.e., 

### disapproval ofa provision does not affect the stringency ofotherportions ofthe SIP), EPA will grant a partial approval ofthe SIP submittal.s 

### The disapproval ofany part ofa SIP submittal starts the clocks for the sanction and FIP requirements.6


### In some instances, inseparable portions ofa SIP submittal may be disapproved. However, ifthe submittal as a whole has a strengthening effect on the SIP, EPA may grant a limited approval ofthe SIP submittal.s

.7 

### The amended Actdoes not address situations requiring limited approval. Rather, EPA 

### is using its "gap-filling" authority under sections 301(a) and llO(k)(3) to interpret the Act to provide for such actions.s,s 

### Under section 1

### lO(k)(4) 

### ofthe amended Act, EPA may conditionally approve a plan based on a commitment ofthe State to adopt specific enforceable measures by a specified date within 1 year from the date ofapproval ofthe plan revision thatincorporated that commitment.9•10 If

### EPA determines that the State fails to meet the commitment within that year, the conditional approval would automatically become a disapproval. The sanctions and PIP clocks do not begin to run until the conditional approval becomes a disapproval.lo



### 9-l7 April 1993 I (.,**E~A's** 

### stated policy is to grant conditional approvals only in

### rare situations thatmerit special consideration and after evaluating specific types ofSIP submittals. To ensure consistency, EPA's policy 

### isto urge the Regions notto use conditionalapplovals without inputfrom Headquarters as to whether such an approach is appropriate. ll In 

### general, the greater the extentto which a submittal is lacking in importantplan elements, the less appropriate the use ofconditional approval may be. In 

### some cases, EPA may accept a SIP revision consisting ofa commitment only (with no specifically adopted rules) as a candidate for conditional approval. 12


### Because conditional approval relies on a commitmentfrom the State, EPA needs to make a determination ofwhether the State can reasonably be expected to meet its commitment. This determination would be based on consideration ofa number offactors including, but not limited to, (I) the amount oftechnical work necessary for the measures to be adopted; (2) 

### whether the measures are controversial; (3) 

### the average length ofthe State adoption process and how far along in 

### the process the State is; and (4) 

### the State'spast track record.13 Forconditional approvals, sanctions and PIP 

### clocks startifand when the approval is converted to a disapproval. 14

9.4.4 

### Grandfathering Generally, all SIPrevisions are evaluated based on the requirements in 

### existence at the time ofEPA's rulemaking. However, EPA does have the flexibility to grandfather certain provisionsin new regulations ifthe following conditions are met: (1) 

### the new rule would represent an abrupt departure from existingpractice; (2) 

### affected partiesmusthaverelied on the old rule; (3) 

### the new rule would impose a large burden on those affected; and (4) 

### there would be little statutory interest in applying the new rule.IS 

### (For grandfathering ofmodeling analyses, see Section 6.2.) 

### Grandfathering is neither mandatory nor automatic. In 

### determining whether to grandfather a State-submitted rule, the decision-maker should focus on whether good-faith efforts were made to comply with the existingrules. Grandfathering should not allow sources to circumvent tighter requirements or agencies to avoid difficultdecisions.16



### 9-18 April 1993

## .' Exceptions to the allowance ofgrandfathering provisions include the following:
• Ifa courtruling has explicitly changed a currentFederalrequirement
• Ifthe old regulation or policy wasill-founded
• Ifitwould have substantial adverse environmentalimpact
• Iflack ofcompliance with the newrequirements renders the SIPinadequate for NAAQS attainmentl'
. 

### 9.4.5 SIP Relaxations All SIPrelaxations should contain the following information in a Federal Reeister notice and/or technical supportdocument: (1) plantname and location; (2) facility size (including number ofunits); (3) revised PM-lO emissionlimit, existing SIP limit, and corresponding averaging times; and (4) actual and "paper" (allowable) emissions decrease or increase.18



### 9.4.6 SIPTightening In general, where a SIP revision willresultin an emissions decrease at a specific source and there is no other change in the stackparameters, a new control strategy demonstration will not be required.

9-19 April 1993REFERENCES FOR SECTION 9.4

1. U.S. Environmental Protection Agency, 

### Guidelinesfor the ReviewofSIP Revisions by 

### EPA Regional Offices. EPA-450/2-89-005, Research Triangle Park, NC, February 1989. 2. 57 FederalRegister 13,565 (April 16, 1992), General Preamble for the Implementation ofTitle I ofthe Clean Air ActAmendments of 1990; Proposed Rule; EPA Requirements; SIP Processing Requirements; Completeness. 3. "In general, there are three situations that can oecurrelated to eachrequired submittal: the State may fail to submittherequired plan, the State may make a submittal thatis notcomplete, or the State may make a complete submittal. Once a State submits a SIP and EPA has determined that the submittal is complete, EPA must either approve or disapprove the submittal within a specified time period. However, ifthe State fails to make a required submittal or makes a submittal thatis determined to be incomplete, the sanctions and FIP provisions ofsection 179 and 1l0(c),respectively, will be triggered." Memorandumfrom Calcagni, John, Director, Air Quality Management Division, OAQPS, U.S. EPA, Research Triangle Park, NC, to Director, Air, Pesticides, and Toxics Management Division, Regions I and IV; Director, Air and Waste ManagementDivision, Region II; Director, Air, Radiation, and Toxics Division, Region III; Director, Air and Radiation Division, Region V; Director, Air, Pesticides and Toxies Division, Region VI; Director, Air and Toxies Division, Regions VII, VIII,IX, and X. Processing ofState Implementation Plan (SIP) Submittals. July 9, 1992. 4. "There are, however, three alternatives to full approval or full disapproval ofa complete SIP submittal: partial approval, limited approval, and conditional approval." Memorandumfrom Calcagni, John, Director, 

### Air Quality ManagementDivision, OAQPS, U.S. EPA, Research Triangle Park, NC, to Director, Air, Pesticides, and Toxies ManagementDivision, Regions I and IV; Director, Air and Waste Management Division, Region II; Director, Air, Radiation, and Toxics Division, Region

### ill; Director, Air and Radiation Division, Region V; Director, Air, Pesticides and Toxies Division, Region VI; Director, Air and Toxics Division, Regions VIT, 

### vrn,IX, and X. Processing ofState Implementation Plan (SIP) Submittals. July 9, 1992. 5. 57 Federal Register 13,565-6 (April 16, 1992), General Preamble for the
. Implementation ofTitle I ofthe Clean AirAet Amendments of 1990; Proposed Rule; EPA Requirements; SIP Processing Requirements; Partial Approvals; Full, Partial, and Limited Approval and Disapproval. 6. "In the case where a separable portion ofthe submittal meets all ofthe applicable requirements, partial approval may be used to approve thatpart ofthe submittal and disapprove the remainder. Itis important that the two parts ofthe submittal be 9-20 April 1993separable. TheEPA can approve some ofthe rules and disapprove the rest as long as therules that are disapproved do notaffectthose that are approved. The disapproval ofanypart ofarequired SIP submiual stamuhecl.acksdiscusscd...above.for.sanctions and FJP's." Memorandumfrom Calcagni, John, Director, Air Quality Management Division, OAQPS, U.S. EPA, Research Triangle Park, NC, to Director, Air, Pesticides, and Toxics ManagementDivision, Regions I and

### N; Director, Air and Waste ManagementDivision, Region

## n; Director, Air, Radiation, and Toxics Division, Region

### ill; Director, Air and Radiation Division, Region V; Director, Air, Pesticides and Toxics Division, Region VI; Director, Air and Toxics Division, Regions VIT, VITI,IX, and X. Processing ofState Implementation Plan (SIP) Submittals. July 9, 1992. 7. "In some cases, a submittal may contain certainprovisions thatmeetthe applicable requirements ofthe Actalong with otherprovisions that do notmeetthe requirements, and the provisions are not separable. Although a submittal may notmeetall ofthe applicablerequirements, EPA maywantto consider whether the submittal as a whole has strengthening effect on the SIP. Ifthis is the case, limited approval may be used to approve a rule that strengthens the existing SIP as representing an improvement over what is currently in the SIP and as meeting some ofthe applicable requirements ofthe Act" Memorandum from Calcagni, John, Director, Air Quality Management Division, OAQPS, U.S. EPA, Research Triangle Park, NC, to Director, Air, Pesticides, and Toxics ManagementDivision, Regions I and 

### N; Director, Air and Waste ManagementDivision, Region 

## n; Director, Air, Radiation, and Toxics Division, Region

### ill; Director, Air and Radiation Division, Region V; Director, Air, Pesticides and Toxics Division, Region VI; Director, Air and Toxics Division, Regions VII, VITI,IX, and X. Processing ofState Implementation Plan (SIP) Submittals. July 9, 1992. 8. "The Act does not expresslyprovidefor limited approvals. Rather, EPA is using its 'gap-filling' authority under section 301(a) ofthe Actin conjunction with section 11O(k)(3) approval provision to interpret the Act to provide for this type ofapproval action.
.. A key distinction between the**~ted** approval and a partial approval is that under a limited approval EPA's approval action goes to the entire rule. In other words, althoughportions ofa rulepreventEPA from finding that the rule meets a certain requirement ofthe Act, EPA believes that the rule, as a whole, strengthensthe SIP. Therefore, EPA approves the entirerule

-- even thoseportions thatprohibitfull approval. Likewise, when EPA issues the limited disapproval, the disapproval applies to the entire rule as failing to meet a specific requirement ofthe Act Therule remains a part ofthe SIP, however, underthe limited disapproval, because therule strengthens the SIP. The primary advantage ofusing the limited approval approach is to make the State submittalfederally enforceable and to increase the SIP'spotential to achieve additionalreductions. Therefore, limited approval should notbeused to approve any rule thatisunenforceable for all situations. These rules and any other rules that do not have an overall strengthening effect on the SIP should be disapproved. Limited approval can be used, however, where the rule is unenforceable for some limited number ofsituations butis enforceable for the majority of situations, 9-21 April 1993ifthe rule, as a whole, strengthens the SIP
. .. The disapproval coinciding with (or following) the limited approval also starts the sanctions and FIP clocks discussed above." Memorandum from Calcagni, John, Director, 

### Air QUality Management Division, OAQPS, U.S. EPA, Research Triangle Park, NC, to Director, Air, Pesticides, and Toxics ManagementDivision, Regions I and IV; Director, 

### Air and Waste Management Division, Region IT; Director, 

### Air, Radiation, and Toxics Division, Region

### ill; Director, 

### Air and Radiation Division, Region V; Director, 

### Air, Pesticides andToxics Division, Region VI; Director, 

### Air and Toxics Division, Regions VIT, 

### vm,IX, and X. Processing ofState Implementation Plan (SIP) Submittals. July 9, 1992. 9. "Under section 1l0(k)(4) ofthe Act EPA may conditionally approve a plan based on a commitmentfrom the State to adopt specific enforceable measures within 1year from the date ofapproval." Memorandumfrom Calcagni, John, Director, Air Quality Management Division, OAQPS, U.S. EPA, Research Triangle Park, NC, to Director, 

### Air, Pesticides, and Toxics ManagementDivision, Regions I and IV; Director, Air and Waste Management Division, Region II; Director, Air, Radiation, and Toxics Division, Region

# m; Director, 

### Air and Radiation Division, Region V; Director, 

### Air, Pesticides and Toxics Division, Region VI; Director, Air and Toxics Division, Regions VII, 

### VITI,IX, and X. Processing ofState Implementation Plan (SIP) Submittals. July 9, 1992. 10. 57 Federal Register 13,566 (April 16, 1992), General Preamble for the Implementation ofTitle I ofthe Clean Air Act Amendments of 1990; Proposed Rule; EPA Requirements; SIP Processing Requirements; Partial Approvals; Conditional Approval. 11. "We will evaluate specific types ofSIP submittals [e.g., reasonable available control technology (RACT) catch-ups, particles with aerodynamic diameter less than or equal to a nominal 10 micrometers (PM-1O) SIP's] to determine whether certain elements of that type ofsubmittal, orthat type ofsubmittal as a whole, merit conditional approval. Forthis reason and to ensure consistency, Regions should notuse conditional approvals withoutinputfrom Heaqquarters as to whether such an approach is appropriate." Memorandumfrom Calcagni, John, Director, Air Quality Management Division, OAQPS, U.S. EPA, Research Triangle Park, NC, to Director, Air, Pesticides, and Toxics ManagementDivision, Regions I and IV; Director, 

### Air and Waste Management Division, Region IT; Director, Air, Radiation, and Toxics Division, Region 

### ill; Director, 

### Air and Radiation Division, Region V; Director, 

### Air, Pesticides and Toxics Division, Region VI; Director, Air and Toxics Division, Regions VII, 

### VITI,IX, and X. Processing of State Implementation Plan (SIP) Submittals. July 9, 1992. 12. "As a general matter, the greater the extentto which a submittalis lacking in importantplan elements, the less appropriate the use ofconditional approval may be. It should be noted however, that there may be circumstances under which EPA would accept a SIPrevision consisting ofa commitment only (without specifically adopted rules) as a candidate for conditional approval. In such cases, the commitment should 9-22 April 1993 

### I

-also be accompanied by a workplan detailing any specific measures to be adopted, the steps that 

### will be taken to adoptthe measures, and the schedule for adoption ofthose measures. As stated earlier, a submittal thatconsists entirely ofa commitment 

### wilLb.econsidered a SIPrevision thatis subjectto the Stateprocess for submitting SIP revisions. Where the submittal contains specifically adoptedrules thatneed some revisions orcorrections to be fully-approvable, the commitmentmay not need to be as comprehensive. The commitment should, however, be as explicit as possible concerning the measures that will be adopted, the steps that will be taken to adopt the measures, and the schedule for adoption ofthose measures." Memorandumfrom Calcagni, John, Director, 

### Air Quality Management Division, OAQPS, U.S. EPA, Research Triangle Park, NC, to Director, 

### Air, Pesticides, and Toxics Management Division, Regions I and IV; Director, 

### Air and Waste Management Division, Region II; Director, 

### Air, Radiation, and Toxics Division, Region 

### ill; Director, Air and Radiation Division, Region V; Director, 

### Air, Pesticides and Toxics Division, Region VI; Director, 

### Air and Toxics Division, Regions VII, VllI,IX, and X. Processing ofState Implementation Plan (SIP) Submittals. July 9, 1992. 13. "Because the conditional approval relies on a commitmentfrom the State, EPA would need some level ofconfidence that the State would be able to meet such a commitment. Inmaking a determination as to whether a State could reasonably be expected to meetits commitment, EPA would need to consider a number offactors such as: the amount oftechnical work necessary for measures to be adopted; whether adoption ofthe measures is expected to be controversial; the average length ofthe State adoption process; how far along in the process the State is; and the State's past trackrecord. It should be noted that these are only some ofthe factors that should be considered. Each Region, in making a determination regarding the credibility ofthe State'scommitment, may have to look at a number ofother factors." Memorandum from Calcagni, John, Director, 

### Air Quality ManagementDivision, OAQPS, U.S. EPA, Research Triangle Park, NC, to Director, 

### Air, Pesticides, and Toxics Management Division, Regions I and IV; Director, 

### Air and Waste ManagementDivision, Region II; Director, 

### Air, Radiation, and Toxies Division, Region 

### ill; Director, Air and Radiation Division, Region V; Director, 

### Air, Pesticides and Toxics Division, Region VI; Director, 

### Air and Toxics Division, Regions VII, VIII,IX, and X. Processing ofState Implementation Plan (SIP) Submittals. July 9, 1992. 14. "Unlike the limited approval/disapproval, the conditional approval does not immediately start the sanctions and FIP clocks. These clocks startifand**whe~** the approval is converted to a disapproval. There are atleasttwo ways that the conditional approval may beconverted to a disapproval. There are atleasttwo ways thatthe conditional approval may be converted to a disapproval. First, ifthe State fails to adopt and submitthe specified measures by the end of 1year (from the final conditional approval), orfails to submit anything at all, EPA will have to issue a finding ofdisapproval but will not have to propose the disapproval
. .. Therefore, at the end of 1year from the conditional approval, the Regional Administrator (RA) will send a letterto the State finding that it had failed to meetits commitment and that the SIP submittal is disapproved. The 18-month clockfor sanctions and the 2-year clock 9-23 April 1993for. FIP start as ofthe date ofthe letter. Subsequently, a notice to that effect will be publishedin the Federal Register, and appropriate language will beinsenedinthe Code ofFederal Regulations. Similarly, ifEPA receives a submittal addressinKthe commitmentbutdetermines that the submittalis incomplete, the RA will send a letter to the Statemaking such a finding. As with the failure to submit, the sanctions and FIP clocks willbegin as ofthe date ofthe finding letter. Second, where the State does make a complete submittal by the end ofthe I-yearperiod, EPA will have to evaluate that submittal to determineifitmaybe approved and take final action on the submittal within 12months after the date EPA determines the submittalis complete. Ifthe submittal does not adequately address the deficiencies that were the subject of the conditional approval, and is therefore not approvable, EPA will have to go through notice-and-commentrulemaking to disapprove the submittal. The 18-month clock for sanctions and the 2-year clockfor a FIP startas ofthe date offinal disapproval." Memorandumfrom Calcagni, John, Director, Air QUality ManagementDivision, OAQPS, U.S. EPA, Research Triangle Park, NC, to Director, Air, Pesticides, and Toxics ManagementDivision, Regions I and IV; Director, Air and Waste Management Division, Region II; Director, Air, Radiation, and Toxics Division, Region ill; Director, Air and Radiation Division, Region 

### V; Director, Air, Pesticides and Toxics Division, Region VI; Director, Air and Toxics Division, Regions VII, vrn,IX, and X. Processing ofStateImplementation Plan (SIP) Submittals. July 9, 1992. 15. "However, an agency does have some flexibility to provide grandfathering provisions in new regulations. Generally, such provisions are appropriate where they meet 

### a four-pantest. First, the newrulerepresents an abrupt departure from well-established practice. Second, affected parties have relied on the oldrule. Third, the new rule imposes a large burden on those affected. Fourth, there is no strong statutory interest in applying the new rule." Memorandum from Emison, G.A., OAQPS, to Director, AirManagementDivision Regions I, 

### ill, and IX; Director, Air, andWaste Management Division, Region 

### II; Director, AirPesticides and Toxics Division Region IV and VI; Director, Air and Radiation Division Region V; and DirectorAir and Toxics Division, Regions

## vn,vrn, and X. June 27, 1988. (PN 110-88-06-27-095).
16. "Grandfathering is not to be considered mandatory or automatic. In determining whether grandfathering should apply, and whatthe appropriate date should be, the decision maker should keep in mind the thrust ofthis guidance, 

### i.e., to honor good faith effon on the pan ofthe State/local agency submitting the revision, balancing equity with other considerations. This guidance expressly is notintended as a vehicle to allow circumvention oftighterrequirements or to facilitate the avoidance ofdifficult decisions." Memorandum from Emison, G.A., OAQPS, to Director, AirManagement Division Regions I, ill, and IX; Director, Air, and Waste ManagementDivision, RegionII; Director, AirPesticides and Toxics Division Region IV and VI; Director, Air and Radiation Division Region 

### V; and Director Air and Toxics Division, Regions 

## vn, vm, and X. June 27, 1988. (PN 110-88-06-27-095).

9-24 April 199317. "B. There are certain exceptions to the general grandfathering guidance:" Items 2,3,4 and 6. Memorandumfrom Emison, G.A., OAQPS, to Director, AirManagement Division Regions I, III, and IX; Directar,..Air.,and.Waste ManagementDivision, Region IT; Director, AirPesticides andToxics Division Region IVandVI; Director, Air and Radiation Division Region 

### V; and Director Air and Toxics Division, Regions VIT, VIll, and X. June 27, 1988. (PN 110-88-06-27-095). 18. "In orderto allow us to assess the relative impact ofeach 

### S02 relaxation more accurately, I askthatthe following information be included in each action memo. 1. Plant name and location. 

### 2. Size ofthe facility (including the number ofboilers) expressed in megawatts or Btu/hour firing capacity (design). 

### 3. Amount, type, and sulfur content ofactual fuel combusted during the previous year. 

### 4. Therevised 

### S02 emission limit, the existing SIPlimit, and the corresponding averaging times for these limits. 5. The "paper" as well as actual increase ordecrease in emissions. Memorandumfrom Rhoads, R.G., OAQPS, to Director, Air and Hazardous Materials Division, Regions I-V and VIll. Information Required in Federal Register Packages. June 12, 1980.

9-25 April 1993

### ·9.5 SANCTIONS AND FIPREQUIREMENTS Section 179(a) ofthe amended Act sets forth specific criteria for EP'A to determine when to apply sanctions. Two types ofsanctions are specified under section 179(b): (1) highway funding restrictions, and (2) increased emissions offsetratios for new and modified sources. A third type ofsanction,restrictions on air grant funding, is provided for under section 179(a). The construction ban provisions ofsection 110(a)(2)(I) ofthe 1977 Clean Air Act Amendments were largelyrepealed with the passage ofthe amended Act in 1990. 1



### 9.5.1 Actions Triggering Sanctions and FIPRequirements Section 179(a) (1) through (4) ofthe amended Act setsforth four types offindings which may trigger sanctions. The first is a finding that a State has failed to submit a SIP or an elementofa SIP, orthat the submittal fails to meet the completeness criteria. The second is a finding that a SIP submission for a nonattainment area is disapproved for failure to meet one or more elements ofthe plan required by the Act. The third is a finding that the State has not made any other submission required by the Act thatmeets the completeness criteria or has made a required submission that is disapproved by EPA for not meeting the Act's requirements. The fourth is a finding that arequirement of an approved plan is not being implemented.1• 2
Section 1l0(c) sets forth two types offindings thattrigger

### FIPrequirements: (1) a finding that a State has failed to make a required submittal or that a submittal does not satisfy the minimum completeness criteria under section 1l0(k)(1)(A), and (2) a disapproval ofa SIP submittal in whole orin part.3



### 9.5.2 Sanction and FIP Clocks The amended Act provides a "clock" for imposing sanctions and 

### FIPrequirements. Section 179(a) allows up to 18 months for the State to correctthe deficiency that triggered EPA's disapproval before EPA must impose sanctions. Section 1l0(c)(1) gives the State two years to correct a deficiency and EPA to approve a new submittal before EPA is obligated to promulgate a FIP.4
9-26 April -1993The sanctions clock, triggered under section 179(a), stops when the State corrects the deficiency prompting the finding. Unless the deficiency is corrected the EPA must apply one ofthe two sanctions specified"under section !19(b) 

## nrmonths afterthe date ofthe finding. If the deficiencypersists, EPA must apply the second sanction 6 months later. EPA must apply both sanctions after 18 months ifit determines there is a lack ofgood faith on thepartofthe State.S The FIPclockcan be stopped only ifthe State corrects the deficiency prompting the finding andEPA issues a final approval ofthe State submittal.6



### 9.5.3 Available Sanctions The two sanctions available to EPA are provided under section 179(b) andinclude restriction on highway funding, and a 2 to 1emission offset requirement. Underthe highway funding sanction, EPA prohibits approval by the Secretary ofTransportation ofprojects or grants in the affected area.? Section 179(b)(1) ofthe amendedActprovides exemptions for certain projects and grants for air quality or safety purposes.8
The emissions offset sanction refers to the application ofthe emission offset requirements of section 173 relating to new ormodified sources. Underthis sanction, the ratio ofemissions reductions that must be obtained to offset increased emissions (caused by the new or modified source) in the sanctioned area must be at least 2 to 1.8,9

9-27 April 1993

### REFERENCES FORSECTION9.5 1. 57 Federal Register 13,566 (April 16, 1992), GeneralPreamble far.the 

### Implementation ofTitle I ofthe'Clean Air ActAmendments of 1990; Proposed Rule; EPA Requirements; Sanctions and Other Safeguards; Available Measures Under 1990 

### CAAA. 2. "The Actin section 179 requires EPA to impose sanctions based on four types of actions (findings) providedin section 179(a): (1) a finding that the State has failed to submit a SIP, a SIP element, or has submitted a SIP or SIP element that does not satisfy the completeness criteria; (2) that EPA disapproval ofa SIP submission for a nonattainment area based on its failure to meet one or more elementsrequired by the Act; (3) a determination that the State has not made any other submission, has made an inadequate submission (as required by the Act), or that EPA disapproves such submission; or (4) a finding that arequirement ofan approved plan

### IS not being implemented." Memorandumfrom Calcagni, John, Director, 

### Air QualityManagement Division, OAQPS, U.S. EPA, Research Triangle Park, NC, to Director, 

### Air, Pesticides, and Toxics ManagementDivision, Regions I and IV; Director, 

### Air and Waste Management Division, Region ll; Director, 

### Air, Radiation, and Toxics Division, Region

### ill; Director, Air and Radiation Division, Region V; Director, Air, Pesticides and Toxics Division, Region VI; Director, 

### Air and Toxics Division, RegionsVII, VIII,IX, and X. Processing of State Implementation Plan (SIP) Submittals. July 9, 1992. 3. "Under section IlO(c)(1), EPA is required to promulgate a FIPbased on two types of findings: (1) a finding that a State has failed to make a required submittal or that a submittal does not satisfy the minimum completeness criteriaunder section IlO(k)(l)(A), or the EPA disapproval ofa SIP submittal in whole or in part" Memorandum from Calcagni, John, Director, 

### Air Quality Management Division, OAQPS, U.S. EPA, ResearchTriangle Park, NC, to Director, Air, Pesticides, and Toxics ManagementDivision, Regions I and IV; Director, 

### Air and Waste Management Division, Region II; Director, Air, Radiation, and Toxics Division, Region III; Director, Air and Radiation Division, Region V; Director, Air, Pesticides and Toxics Division, Region VI; Director, Air and Toxics Division, Regions VII, VITI,IX, and X. Processing ofState Implementation Plan (SIP) Submittals. July 9, 1992. 4. "For plan submittalsrequired under PartD or 

### in response to a SIP call, section l79(a) allows for up to 18 months for the State to correct the deficiency thatis the subject of a finding or disapproval before EPA is required to impose sanctions. Section 1l0(c)(1)provides for up to 2 years for the State to correct the deficiency and for EPA to approve a new submittal before EPA is obligated to promulgated a FIP." Memorandumfrom Calcagni, John, Director, 

### Air Quality Management Division, OAQPS, U.S. EPA, ResearchTriangle Park, NC, to Director, 

### Air, Pesticides, and Toxics ManagementDivision, Regions I and IV; Director, Air and Waste Management Division, Region II; Director, Air, Radiation, and Toxics Division, Region III; Director, Air and Radiation Division, Region V; Director, Air, Pesticides and Toxics 9-28 April 1993

### Division, Region VI; Director, Air 

### and Toxics Division, Regions VII, VITI,IX, and X. Processing ofState hnplementation Plan (SIP) Submittals. July 9, 1992. 5
. "Under section 179(a), in order to stop the sanctions clock, the State must correct the 'deficiency'prompting the finding. The EPA must apply one ofthe two sanctions availableunder section 179(b) within 18 months after the date ofthe finding and both sanctions at 24 months, unless the deficiency has been corrected. Section 179(a) also requires EPA to apply both sanctions after 18 months ifEPA finds a lack ofgood faith on the partofthe State." Memorandum from Calcagni, John, Director, Air Quality ManagementDivision, OAQPS, U.S. EPA, Research Triangle Park, NC, to Director, Air, 

### Pesticides, and Toxics ManagementDivision, Regions I and IV; 

### Director, Air 

### and Waste Management Division, Region 

### IT; Director, Air, Radiation, and Toxics Division, Region 

### lIT; Director, Air 

### and Radiation Division, Region 

### V; Director, Air, 

### Pesticides and Toxics Division, Region VI; Director, Air and Toxics Division, Regions VII, Vill,IX, and X. Processing ofState Implementation Plan (SIP) Submittals. July 9, 1992. 6. "In 

### other words, EPA must approve the State submittalin order to stop the FIP 

### clock. Where the sanctions and PIP 

### clocks were started by EPA disapproval ofaplan, the clocks willrun concurrently. In this case, to correct the deficiency for purposes ofthe sanctions clock, the State mustmake a submittal which EPA finds approvable. Such a 

### determination is not made until EPA issues a final approval ofthe plan. Final approval ofaplan is also what is needed to stop the PIP 

### clock." Memorandum from Calcagni, John, Director, Air 

### Quality Management Division, OAQPS, U.S. EPA, Research Triangle Park, NC, to Director, Air, Pesticides, and Toxies Management Division, Regions I and IV; 

### Director, Air and Waste Management Division, Region IT; 

### Director, Air, Radiation, and Toxics Division, Region ill; Director, Air 

### and Radiation Division, Region V;**Dire~tor,** 

### Air, Pesticides and T<>xics Division, Region VI; Director, Air and Toxics Division, Regions 

### vn, vm,IX, and 

### X. Processing ofState Implementation Plan (SIP) Submittals. July 9, 1992. 7. "For

### plan submittals required under PartD or in response to a SIP call, if

### the State does not correct the specific deficiency within the 18-month period allowed under section 179(a), EPA must apply at least one ofthe two sanctions available under section 179(b) as described: (1) 

### Highway funding sanctions: The EPA may impose a 

### prohibition on the approval by the Secretary ofTransportation ofcertain projects, or the awarding ofcertain grants." Memorandum from Calcagni, John, Director, Air Quality Management Division, OAQPS, U.S. EPA, Research Triangle Park, NC, to Director, Air, 

### Pesticides, and Toxics Management Division, Regions I and IV; 

### Director, Air and Waste Management Division, Region 

### IT; Director, Air, Radiation, and Toxics Division, Region ill; Director, Air 

### and Radiation Division, Region V; Director, Air, 

### Pesticides and Toxics Division, Region VI; Director, Air

### and Toxics Division, Regions VII, Vill,IX, and X. Processing ofState Implementation Plan (SIP) Submittals. July 9, 1992.

9-29 April 19938. 57
.Federal Register 13,566 (Apri116, 1992), General Preamble for the Implementation ofTItle I ofthe Clean AirAct Amendments of 1990; Proposed Rule; EPA Requirements; Sanctions and Other Safeguards; Available Measures Under 1990 CAAA; Highway Funding Sanctions. 9. "(2) Offset sanctions. A ratio ofat least 2-to-1 will be required for emissions reductions within the nonattainment area to offset emissions from new ormodified majorfacilities (as required under section 173)." Memorandumfrom Calcagni, John, Director, 

### Air Quality ManagementDivision, OAQPS, U.S. EPA, Research Triangle Park, NC, to Director, Air, Pesticides, and Toxics ManagementDivision, Regions I and IV; Director, Air and Waste Management Division, RegionIT; Director, 

### Air, Radiation, and Toxies Division, Region 

### ill; Director, Air and Radiation Division, Region V; Director, Air, Pesticides and Toxics Division, Region VI; Director, Air and Toxies Division, Regions VII, VllI,IX, and X. Processing ofState Implementation Plan (SIP) Submittals. July 9, 1992.

9-30 April 1993

### 9.6 INTERIM CONTROL STRATEGIES In certain situations, airpollutioncontrol equipment may needtoberepaired, upgraded orreplaced to meetthe applicable emission limitations in a revised SIP. During the period until new or upgraded control equipmentis operational and the source is in compliance, emissions from the source mustnotbe allowed to increase. The existing control equipment mustremain operational to the maximum extentpossible, with appropriate maintenance and repair, until construction orlinking ofnew equipmentrequires its shutdown or removal. A source may choose to implementinterim controls that offer a higher degree of emission reduction instead ofmaintaining existing equipment. However, the use ofsuch interim controls should not be allowed to unnecessarily delay the installation offinal control equipment.l Additional interim controls or other interim measures are required to prevent excess emissions during periods when existing control equipment must be takenoffline to 

### link or complete construction ofnew or upgraded equipment. Such measures may include installing additional temporary control equipment or operational controls (such as curtailing production rates, relocating production to complyingprocess lines, "purchasing power orproduct elsewhere," or temporary shutdown).2 The source should also berequired to implement an interim continuous emissions monitoring program. This will enable the agency to monitoremissions from the source during the interimperiod
.3

9-31 April 1993

### REFERE.NCES FORSECTION9.6

1. "During the interimperiod until the new or upgraded control equipmentis operational and the sourceis in compliance, emissions from the source must not be allowed to increase. The existing though inadequate control equipmentmustremain operational to the maximum extentpossible, including being maintained and repaired, until such time that construction ortie-in ofnew equipmentrequires its shutdown orremoval. In lieu ofmaintaining the existing though inadequate control equipment, interim controls which offer a higher degree ofemission reduction and are readily and reasonably available may be installed. The use ofsuch interimcontrols shall not unduly delay the installation offinal control equipment" Memorandum. Seitz, John S., Director, Stationary Source Compliance Division, OAQPS, U.S. EPA, Washington, DC, to AirManagementDivision Directors, Regions I, III, and IX; Air and Waste Management Division Director, Region II; Air, Pesticides and Toxics Management Division Directors, Regions IV and VI; Air and Toxics Division Directors, Regions VII, VIII and X; and Air and Radiation Division Director, Region V. Transmittal of OAQPS Interim Control Policy Statement March 31, 1988. (pN 113-88-03-31-047). 2. "When existing control equipment must be taken offline to tie in or complete construction ofnew orupgraded equipment, additional interim controls or other interimmeasures are required to ensure no increase in excess emissions occurs during the tie in period. Such measures may include installation ofadditional temporary control equipment or operational controls, e.g., curtailment ofproduction rates, relocation ofproduction to complying process lines orfacilities, purchase ofpower or product elsewhere as needed, or temporary shutdown." Memorandum. Seitz, John S., Director, Stationary Source Compliance Division, OAQPS, U.S. EPA, Washington, DC,

# to AirManagementDivision Directors, Regions I, III, and IX; Air and Waste Management Division Director, Region II; Air, Pesticides and Toxics Management Division Directors, Regions IV and VI; Air and Toxics Division Directors, Regions Vii, VIII and X; and Air and Radiation Division Director, Region 

### V. Transmittal of OAQPS Interim Control Policy Statement. March 31, 1988. (PN 113-88-03-31-047). 3. "The source should also be required to implement an interim continuous emissions monitoring program, to enable the agency to monitor the emissions performance ofthe source during the interim period." Memorandum. Seitz, John 

### S., Director, Stationary Source Compliance Division, OAQPS, U.S. EPA, Washington, DC, to Air Management Division Directors, Regions I, Ill, and IX; Air and Waste Management Division Director, Region II; Air, Pesticides and Toxics Management Division Directors, Regions IV and VI; Air and Toxics Division Directors, Regions Vii,

## vrn and X; and Air and Radiation Division Director, Region V. Transmittal ofOAQPS Interim Control Policy Statement. March 31, 1988. (PN 113-88-03-31-047).

9-32 April 1993

### 9.7 SIP CALLS In accordance with Section llO(k)(5) ofthe amendedAct, the Administrator shall require the State to revise the SIP as necessary ifthe Administrator detennines that the applicable implementation plan for any area is substantially inadequate to attain or maintain the relevant NAAQS. The Administrator shall establish deadlines (18 months maximum after date ofnotice) for the submittal ofrevised plans. Inadequate plan findings and notice shall be public. Section llO(a)(2)(H)requires that SIP's provide for plan revisions as necessary to take account ofNAAQS revisions orthe availability ofimproved ormore expeditious methods for attaining the standards. Such revisions should also be provided for should the Administrator find that the plan is substantially inadequate to attain the applicable NAAQS, orto otherwise comply with any additional requirements ofthe Act. Relevant exceptions to these requirements for plan revisions are set forth in section 11O(a)(3)(C). Plan revisions for nonattainment areas are addressed in part D ofTitle I ofthe Act. Any plan revision for a nonattainment area that is required in response to a section llO(k)(5) finding must correct the plan deficiency and meet all other applicable plan requirements under sections llO(a)(2) and partD ofthe Act. EPA may reasonably adjust the applicable deadlines to achieve a consistent application ofplan requirements ifthe applicable attainment date has elapsed. EPA will issue written guidelines, as necessary. to facilitate submittal of adequate and approvable plans.

9-33 April 1993

### 10.0 PERMIT REQUffiEMENTS The discussion belowpertainsto permit'requirements for construction and operation of major new ormodified sources. Title V ofthe Clean 

### Air Act of 1990, however, does include provisions for establishing State-administered operatingpermitprograms. The EPA has promulgatedregulations containing the minimum elements necessary for federally enforceable operating permitprograms,l while EPA has notreached a final determination about the relationship between SIP's and Title V permits.2 

### Operating permits may, among other things, largely codify present SIP regulations. For this reason, it is important that SIP's are adequate and enforceable before operating permitprograms are in place. The operating permitprogram is not discussed in 

### this guideline.



### 10.1 GENERAL Major new sources and existing sources that have undergone major modifications are generally required to obtain air

### pollution permits prior to construction/modification and operation. Permits are required to assure that sources do notjeopardizeplans to attain or maintain NAAQS or PSD increments. Therequirements for these permits vary depending on the size and location ofthe proposed source. For a complete compendium ofnew source review and permitting guidance seeNew SourceReview/Prevention ofSignificant Deterioration andNonattainmentArea Guidance 

### Notebook.3 

### Additional information is available on the New Source Review Electronic Bulletin Board and the New SourceReview Workshop Manual.4



### 10-1 April.1993

### REFERENCES FOR SECTION 10.1

1. 

### 57 Federal Register 32,250 (July 21, 1992), Operating PennitProgram. 2. 57 Federal Register 13,567-9 (April 16, 1992), General Preamble for the Implementation ofTitle I ofthe Clean Air Act Amendments of 1990; Proposed Rule; Miscellaneous. 3. U.S. Environmental Protection Agency. New SourceReview/Prevention of Significant Deterioration andNonattainmentArea Guidance Notebook, Volumes I andIIand Updates. 

### 4. U.S. Environmental Protection Agency. New Source Review Workshop Manual, (Draft). 

### Office ofAir Quality Planning and Standards, Research Triangle Park, NC 27711. October 1990. pp. F.2-F.4.

10-2 

### April 1993

### 10.2 NONATTAINMENT AREAS

10.2.1 Applicability
All new ormodified major stationary sources located within an area designated under section 107 ofthe Act as nonattainment are required to obtainpennitsfor construction and operation thatmeet the requirements ofsection 173. MajorPM-lO sources in moderate PM10 nonattainment areas are sources that have the potential to emit greaterthan 100 tpy; major modifications occur ifthey increase emissions by a significant amount. 1



### 10.2.2 Control Technology Requirements
All major sources subjectto nonattainment area new sourcereview requirements are required to control emissions to a degree that reflects the lowest achievable emissionrate (LAER).2 LAER is defined as the most stringent emission control actually achieved in practice or contained in any SIPregulations. These control techniques must be applied to the proposed new source unless they are demonstrated to be technically infeasible, cost considerations notwithstanding.3



### 10.2.3 Emission Offsets Offsetting emissionreductions in actual emissions for sources locating in nonattainment areas must be obtained to offset increases in allowable emissions thatresult after the application ofLAER.4 The emission offset must exceed the net increase from the proposed source and the source growth previously accounted for sothatreasonable progress toward attainment ofthe NAAQS continues. Consistent withprovisions of40 CFR 51.165(a), new sources for which emission offsets arerequired must also comply with proceduresrelating to the permissible location ofoffsetting emissions, which are equivalent or more stringent than those set out in 40 CFR Part 51 Appendix S section IV.D.

10-3 April 1993

### 10.2.4 Net Air QualityBenefit
Forthose sources thatdo not satisfy the locationrequirements**for~**emission offsets as specified in 40 CPRPart

### 51 Appendix S section IV.D, a net air quality benefit must be demonstrated.s This demonstration is made with a modeling analysis thatpredicts that the proposed emissionincreaseLAER and emission offsets proposed will notincrease the concentration at an agreed upon number ofreceptors where NAAQS exceedances have been identified and will not significantly increase the concentration atall otherreceptors where NAAQS exceedances have been identified.



### 10.2.5 OtherRequirements Any applicant for a new source permit within a nonattainment area must certify that all othermajor stationary sources owned or operated by the applicant are in compliance with applicable air quality regulations. Compliance includes being on an approved compliance schedule.6 An analysis ofalternative sites, sizes, production processes, and environmental control techniques is required to demonstrate thatthe benefits ofthe proposed source outweigh the environmental and social costs imposed as a result ofits location, construction, and modification.7



### 10.2.6 NSR Transition The amended Act makes numerous changes to the NSRrequirements for nonattainment and PSDprograms. These include creation ofnew and expanded nonattainment areas, extension ofPSD coverage to Class I area boundaries, and a mandate for a PSD exemption for certain hazardous airpollutants. The EPA has provided its interpretation ofthe new or revised NSRnonattainment permitprogramrequirements contained in Part D ofthe amended Actin the General Preamble, New Source Review NonattainmentPermit Requirements. The EPA intends to issueregulations setting forth specific requirements for an approvable NSRprogram.s

10-4 April 1993EPA has published transitional guidance on the most importantissues involving the NSRprogramto be usedin preparing SIPrevisions in the interimbetween passage ofthe amendedAct and adoption ofthe**A.gency~** finalregulations. This guidance appeared in a March 11, 1991 memorandum and is published in Appendix D ofthe GeneralPreamble. The transitional guidance is not intended to replace existing State regulations or approved SIP's; however, it calls upon States to implement their NSR programs consistent with provisions of the amended Actthat are applicable immediately.9 The transitional guidance, since it does notrepresent final EPA action, has not been subject tojudicialreview and is not intended, and cannot be relied upon, to create any rights enforceable in litigation with the United States. The EPA may decide to follow the transitional guidance, orto act at variance with it based on specific circumstances. The Agency may also change the guidance at any time withoutpublic notice.10 Major issues relating to NSR PM-lO nonattainment dealt with in the transitional guidance include the following: NSR constructionpermit requirements in nonattainmentareas. In States where the existing PartD permit program covers all designated nonattainment areas in the State, the program will automatically cover any new orexpanded areas under the amended Act and States should apply the requirements oftheir existing programs. In other States, where a Part D program may be limited to specific areas and does not apply to new orexpanded areas, States mustimplement a transitional permitprogram until their existingprograms are revised to meetthe requirements ofthe amended Act, and expanded to cover all nonattainment areas in the State.I I Status ofconstruction bans. An existing construction ban that was imposeddue to the absence ofapproved Part D NSR rules remains in effect until a revised NSR SIP is approved. Specific construction bans may be lifted where appropriate. The status of construction bans in general will be published in the Federal Register. Ifa construction ban is lifted in a nonattainment area, and the area lacks an approved Part D NSR rule, the State should meet the requirements ofappendix S to 40 CFR part 51 in issuing permits for major new sources or major modifications until NSR rules meeting the requirements ofthe amended Act are adopted. 12

• Federal implementationplans. The NSR permitting program in an existing FIP remains in effect until a SIP is approved or a revised FIP is adopted. 13 Use of previously approved growth allowances. Growth allowances in existing SIP's are invalidated [pursuant to section 173 (b) ofthe amended Act] in areas where a SIP call has been received either before or after enactment ofthe 1990 Amendments. In such areas, previously approved growth allowances cannot be used for NSR permits 10-5 April 1993iss.ued on or afterNovember 15, 1990. Construction permits thatrely on previously approved growth allowances cannotbe issued in SIP call areas under existing, approved PartD programs. Emission offsets must be obtained on a case by case basis for any suchpermits, and any otherexisting PartD requirements must be met.f4 In a September 3, 1992 memorandum, the EPA provided a supplementto the transitional guidance in orderto clarify EPA's positionregarding the NSR permitting when a State does not submit a SIPrevision implementing the additional PartD NSRprovisions of the amended Actby the applicable statutory deadline. ForPM-10, the statutory submittal deadline for such revisions was June 30, 1992. This supplemental guidance is nonbinding in the same sense as the initial transition guidance and does not affect EPA's interpretations of NSRprovisions in the amended Act as published in the GeneralPreamble.IS The supplemental guidance addresses conditions under which permits may be issued to sources and obtain EPA recognition as being in compliance with the Act In general, sources that have submitted complete permit applications by the submittal deadline may receivepermits and be recognized as complying with the Act, provided that specific conditions are met. These conditions are spelled outin the guidance.I6 Sources that have not completed applications by the submittal deadline may be considered as complying with the Actprovided thatthe source obtains apermitfrom the State that is consistent with the substantive new NSR PartD provisions. Those applicable to PM-lO include new applicability thresholds, offsetratios, and section 173 offsetrequirements.I7 This guidance does not overrule any State rules ortransitional guidance thatmay be more stringent.IS

10-6 April 1993

### REFERENCES FOR SECTION 10.2



### 1. U.S. Environmental Protection Agency. Code of FederalRegulations. 

### Title 40, Chapter I. 

### Subchapter C, Part 51.165(a)(1)(iv). July 1, 1991. 2. U.S. Congress. Clean Air Act, as amended November 1990. 42 U.S.C. 7401 et. seq. Section 171(3). Washington, D.C. U.S. GovernmentPrinting Office. 3. U.S. Environmental Protection Agency. Code of FederalRegulations. 

### Title 40, ChapterI, Subchapter C,

- Part 51. Appendix S. July 1, 1991. 4. U.S. Congress. Clean Air Act, as amended November 1990. 42 U.S.C. 7401 et. seq. Section 173(a). Washington, D.C. U.S. Government Printing Office. (See also U.S. Environmental Protection Agency. Code ofFederalRegulations. 

### Title 40, ChapterI, Subchapter C, Pan 51. Appendix S. July 1, 1991.) : 5. U.S. Environmental Protection Agency. Code of FederalRegulations. 

### Title 40, ChapterI, Subchapter C, Part 51. Appendix S.lV.A. July 1, 1991. 6. U.S. Congress. Clean Air Act, as amended November 1990. 42 U.S.c. 7401 et. seq. Section 173(3). Washington, D.C. U.S. GovernmentPrinting Office. 7. U.S. Congress. Clean Air Act, as amended November 1990. 42 U.S.c. 7401 et. seq. Section 173(a). Washington, D.C. U.S. Government Printing Office. 8. "The Clean Air Act Amendments of 1990 (1990 Amendments) make numerous changes to the NSR requirements ofthe prevention ofsignificant deterioration (PSD) and nonattainment area programs. The 1990 Amendments create new and expanded nonattainment areas, extend PSD coverage to current Class I area boundaries, and mandate aPSD exemption for cenain hazardous airpollutants. The Environmental Protection Agency (EPA) intends to propose by Septemberofthis year aregulatory package that will implement these and other changes to the NSR provisions. Final adoption ofthese revised regulations is projected for August 1992. In the interim period between passage ofthe 1990 Amendments and adoption ofthe Agency's final regulations EPA expects that numerous issues regarding the 1990 Amendments will arise." Memorandum from Seitz, John S., Director, OAQPS, U.S. EPA, Research Triangle Park, NC, to Addressees. New Source Review (NSR) Program Transitional Guidance. March 11, 1991. 9. "This guidance document does not supersede existing State regulations or approved State implementation plans. However, in some cases, it

### calls upon States to implement their NSR programs in a manner consistent with provisions ofthe 1990 Amendments that are applicable immediately and with the requirements that flow directly from these provisions
." Memorandum from Seitz, John S., Director, OAQPS, 10-7 

### April 1993

### U.S. EPA, Research Triangle Park, NC, to Addressees. New Source Review (NSR) Program Transitional Guidance. March 11, 1991. 10. "Nonetheless, the policies set out in the transition memorandum are intended solely as guidance and do notrepresent final Agency action. They are notripe forjudicial review for this reason. Moreover, they are not intended, nor can they be relied upon, to create any rights enforceable by any party in litigation with the United States. The EPA officials may decide to follow the guidance providedin this memorandum, or to act at variance with the guidance, based on an analysis ofspecific circumstances. The Agency also may change this guidance at any time without public notice." Memorandum from
.John S., Director, OAQPS, U.S. EPA, Research Triangle Park, NC, to addressees. New Source Review (NSR) Program Transitional Guidance. March 11, 1991. 11. "In many States, the existing approvedPart Dpermit program by its terms covers all designated nonattainment areas in the State, so PartD permitprogram will automatically apply to the new and expanded nonattainment areas which are established under provisions ofTitle I ofthe 1990 Amendments. Thus, until new rules are adopted for these new or expanded nonattainment areas, States should apply the requirements oftheir existing approved PanD permit program. However, in .Jther States Part D program may be limited to 

### specified areas and does not apply to new or expanded areas. In these cases, States must implement a transitional permitting program until their existingPart Dprograms are revised to meet the requirements of the 1990 Amendments and expanded to cover all nonattainment areas in the State. Otherwise, both the goals ofpart D and Congress' intent in creating new or expanded nonattainment areas will be frustrated." Memorandum from Seitz, John S., Director, OAQPS, U.S. EPA, Research Triangle Park, NC, to addressees. New Source Review (NSR) Program Transitional Guidance. March 11, 1991. 12. "Pursuant to section 110(n)(3), an existing construction ban that was imposed due to the absence ofapproved PartD NSR rules remains in effect until arevised NSR SIP is approved. Existing construction bans imposed due to disapproval ofprimary sulfur dioxide NAAQS attainment plans alsoremain in effect. A Federal Register notice will be published soon announcing the status ofconstruction bans in general and also lifting specific bans where appropriate. Should a construction ban be lifted in any area designated as nonattainment, and the area lacks an approved Part D NSR rule, the State should meet the requirements of40 CFR part 51, appendix S, in issuing permits to major new sources ormajor modifications prior to the adoption ofNSR rules meeting the requirements ofthe 1990 Amendments." Memorandum from Seitz, John S., Director, OAQPS, U.S. EPA, Research Triangle Park, NC, to addressees. New Source Review (NSR) Program Transitional Guidance. March 11, 1991. 13. "The NSR permitting program in an existing FIPremains in effect until a SIP is approved or arevised FIP is adopted." Memorandum from Seitz, John S., Director, OAQPS, U.S. EPA, Research Triangle Park, NC, to addressees. New Source Review (NSR) Program Transitional Guidance. March 11, 1991. 10-8 

### April 1993

### 14. "Section 173(b) invalidates growth allowances in existing SIP's in areas thatreceived a SIP call prior to enactment ofthe 1990 Amendments, or that received one thereafter. ForNSR permits issued on or after November 15,**1990~** 

### previouslyapproved growth allowances cannot be used in these areas. Construction permits cannot be issued in SIP-call areas under existing EPA-approvedPartD programs to the extent that such permits rely on previously-approved growth allowances. Case-bycase emission offsets must be obtainedfor any such permits, andother existing PartD requirements must be met." Memorandum from Seitz, John S., 

### Director, OAQPS, U.S. EPA, Research Triangle Park, NC, to addressees. New Source Review (NSR) ProgramTransitional Guidance. March 11, 1991. 15. "To address some immediate concerns generated by the 1990 CAAA, the Environmental Protection Agency (EPA) issued an initial NSR transitional memorandum on March 11, 1991, entitled 'New Source Review ProgramTransitional Guidance.' This memorandum supplements that effort by clarifying EPA guidance regarding the permitting ofnew ormodified sources in situations where a State does not submit a State implementation plan (SIP) revision implementing the augmented Part D NSR provisions ofthe 1990 CAAA by the applicable statutory deadline. The statutory deadlines for submission ofrevised NSR SIP's are listed in the attachment. Moreover, as more fully set forth in the March 11, 1991 transitional memorandum, this supplemental memorandum sets forth nonbinding guidance that does not create any rights or otherwise predetermine the outcome ofany procedures. Also, many of EPA's interpretations ofthe new Part D NSR requirements are in the 'General Preamble for the Implementation ofTitle I ofthe Clean Air Act Amendments of 1990' (General Preamble) (see 57 FR 1398, 13552-556, April 16, 1992). These interpretations are not affected by this memorandum." Memorandum from Seitz, John S., 

### Director, OAQPS, U.S. EPA, Research Triangle Park, NC, to Addressees. New Source Review (NSR) Program Supplemental Transitional Guidance on Applicability ofNew Part D NSR Permit Requirements. September 3, 1.992. 16. "Where States do not submit the Part D NSR SIP by the applicable statutory deadline

... sources that have submitted complete permit applications
... by the submittal deadline may receive final permits under existing State NSR rules. In this situation, such sources will be considered by EPA to be in compliance with the Act without meeting the amended Part D NSR provisions ofthe 1990 CAAA, provided they meet the following conditions: 1. The State and source move expeditiously towards final permit issuance. 2. Construction begins no later than 18 months from the date ofpermit issuance unless an earlier time is required under the applicable SIP. 3. Construction is not discontinued for a period of 18 months ormore.

10-9 

### April 19934.
. Constructionis completedwithin areasonable time. States may not grant permit extensions beyond these time periods unless the permittee is required in a federally-enforceable manner to meet the new Part D NSR provision." Memorandum from Seitz, John S., Director, OAQPS, U.S. EPA, Research Triangle Park, NC, to Addressees. New Source Review (NSR) Program Supplemental Transitional Guidance on Applicability ofNew PartD NSR Permit Requirements. September 3, 1992. 17. "Also, undertoday's guidance, where States miss the statutory deadline forPartD NSR SIP submittal, for sources that have not submitted complete permit applications by the SIP submittal deadline, EPA will also considerthe source to be in compliance with the Act where the source obtains from the State a permit that is consistentwith the substantive new NSR Part D provisions in the 1990 CAAA. The substantive new provisions are the new applicability thresholds, the new offsetratios, the offset requirements ofSection 173, and the NOx requirements ofsection 182(f) for most 0 3 nonattainment areas and the NOTR." Memorandum from Seitz, John S., Director, OAQPS, U.S. EPA, Research Triangle Park, NC, to Addressees. New Source Review (NSR) Program Supplemental Transitional Guidance on Applicability ofNew PartD NSR Permit Requirements. September 3, 1992. 18. "Please note that the Act allows States to implementthe new Part D NSR provisions prior to the statutory deadlines and in a mannermore stringent than EPA guidance or rules. Thus, today's guidance does not apply in any State to the extent that the State's own rules ortransitional guidance is more stringent." Memorandum from Seitz, John S., Director, OAQPS, U.S. EPA, Research Triangle Park, NC, to Addressees. New Source Review (NSR) Program Supplemental Transitional Guidance on Applicability ofNew Part D NSR Permit Requirements. September 3, 1992.
.

10-10 April 1993

### 10.3 PSD AREAS

10.3.1 Applicability Majornew stationary sources located within areas designated attainment or unclassifiable pursuant to section 107 ofthe Act are required to undergo preconstruction review in accordance with regulations for the prevention ofsignificant deterioration.1.2 Prevention ofsignificant deterioration defines a new orexisting major stationary source as one which has the potential to emit 250 tpy ormore (or 100 tpy, ifthe source category is one ofthe 28 categories specifically listed in the PSD regulations) ofanypollutant subject to regulation under the Act. Any new major stationary source that also has the potential to emit 15 tpy or more ofPM-I0 in an area designated attainment orunclassifiable for PM-1O (or 25 tpy ofparticulate matter emissions in an area designated attainment orunclassifiable for TSP) mustundergo PSD review with respectto those emissions. Similarly, any existing major stationary source thatproposes aphysical or operational change that would increase emissions ofPM-1O by 15 tpy or more (25 tpy or more for particulate matter emissions) is also subject to PSD review for the resulting net emissions increase.



### 10.3.2 ControlTechnology Requirements Major sources subjectto PSD review for PM-1O are required to control emissions of that pollutant to a degree thatreflects the best available control technology (BACf)? A BACfanalysis is completed on a case-by-case basis, and considers energy, environmental, and economic impacts in detennining the maximum degree ofreduction achievable for the proposed source or modification. In no event can the detennination ofBACTresult in an emission limitation which would not meetany applicable standard ofperformance under 40 CFR Parts 60 and 61.



### 10.3.3 Air Quality Analysis The applicant for a PSD pennitis required to demonstrate via a modeling analysis that the proposed new emissions will not cause or constitute to a violation ofany NAAQS and
10-11 April 1993PSD incre
. ments.4• S The NAAQS impose a ceiling on total ambientconcentrations. Increments impose a limit on the maximum amount ofincrease in ambient concentrations relative to a baseline concentration. NAAQS for PM-lO and increments for TSP are expressed for annual and 24-hourperiods. A demonstration ofcompliance with the NAAQS is based on a modeling analysis in a manner that is consistentwith the 

### Guideline onAirQualityModeling (Revised) (see Chapter 6 for more detail). To meetpreconstruction monitoringrequirements underthe PSD program, monitoring data may need to beprovided by the applicant. When monitoring data are required, guidance is available in the

### AmbientMonitoring Guidelinesfor Prevention of SignificantDeterioration (PSDl (see Chapter 5 for more detail). The air quality analysis should also be used as a basis for establishing PM-lO emission limits ifBACT-derived limits are not sufficient In either case, the limits mustbe sufficient to protectthe NAAQS and the PSD increments. Thus, PSD emission limits thatreflectthe air quality analysis will need to be specified based on annual and 24-hour averaging periods.7



### 10.3.4 Other Impacts

Pursuant to 40 CFR Part51.166(0), the applicantmustprepare additional impact analyses for each pollutant subject to regulation under the Act which will be emitted by the proposed new source or modification.2• 8 The analysis assesses the impacts ofair, ground, and water pollution on soils, vegetation, and visibility caused by any increase in emissions ofany regulated pollutant from the source or modification under review, and from associated growth. Other impact analysis requirements may also beimposed on apermit applicant under local, State, or Federal laws which are outside the PSD permitting process. Receipt of a PSD permit does notrelieve an applicantfrom the responsibility to comply fully with such requirements. For example, two Federal laws which may apply on occasions are the 

### EndangeredSpeciesActand the

### NationalHistoric PreservationAct. Such legislation may require additional analyses (although not as part ofthe PSD permit) ifany federally-listed rare or endangered species, or any sites that are included (or are eligible to be included) inthe National Register ofHistoric Sites, are identified in the source's impact area. Secondary

10-12 April 1993emissions (i.e., emissions not caused by the new source itself, but from associated growth) mustbe included in the impact analyses.
An analysis ofvisibility impairmentis conducted using a three-level screening technique. The analysis method is described in the EPA document entitled, Workbookfor Estimating Visibility Impairment.9



### 10.3.5 ClassI Areas The PSD program is designed to provide the greatestdegree ofprotection to Class I areas. Mandatory Class I areas are those specified by the Act They are protected by stringent Class I PSD increments and air quality-related values (AQRV's) thatthe Federal Land Manager (FLM) has an affIrmative duty to protect AQRV's are those attributes of

### a Class I area that are dependent on the maintenance ofa high level ofambient air quality. These may include, among other things, acid deposition effects and visibility impairment in Class I areas. Sources located within 100 kilometers ofa designated Class I area with an ambient impact greater than 

### 1microgramper cubic meterfor a 24-hour average are required to notify the FLM, who mayrequire the applicant to conduct a Class I area impact assessment A Class I impact analysis must show that the source will not cause or contribute to a Class I increments violation
. Otherwise, the applicant must demonstrate to the satisfaction ofthe FLM that no AQRV's are adversely affected. 

### Hno incrementviolations are shown to occur, then the FLM may call for denial ofthe PSD permit, ifadverse impacts on any AQRV can bedemonstrated. Procedures for Class I review, includingresponsibilities for both the FLM and the reviewing agency, are contained in the EPA New SourceReview Workshop Manual (Draft, October 1990, ChapterE) and in guidance documents produced by the National Parks Service, Forest Service, and Fish and Wildlife Service.

10-13 April 1993

### REFERENCES FOR

### SECTION 10.3

1. 

### U.S. Environmental Protection Agency. Code of FederalRegulations. 

### Title 40, Chapter I, Subchapter C, Part 51.166(b)(I)(i). July 1, 1991. 2. U.S. Environmental Protection Agency. New SourceReview Workshop Manual-PartI, 

### (Draft). Office ofAir Quality Planning and Standards, Research Triangle Park, NC 27711. October 1990. 3. U.S. Congress. Clean Air Act, as amended November 1990. 42 U.S.C. 7401 et. seq. Section 165(a)(4). Washington, D.C. U.S. Government Printing Office. (See also U.S. Environmental Protection Agency. Code of FederalRegulations. 

### Title 40, ChapterI, Subchapter C, Part 51.166(j)(2). July 1, 1991.) 4. U.S. Environmental Protection Agency. NewSourceReview Workshop Manual, 

### (Draft). Office of

### Air Quality Planning and Standards, Research Triangle Park, NC 27711. October 1990. Chapter C. 5. U.S. Environmental Protection Agency. Code of FederalRegulations. 

### Title 40, ChapterI, Subchapter C, Part 51.166(k). July 1, 1991. 6. U.S. Environmental Protection Agency. AmbientMonitoring Guidelinesfor Prevention ofSignificantDeterioration (PSD). 

### Office ofAir Quality Planning and Standards, Research Triangle Park, NC. EPA-450/4-87-007. May 1987. 7. "This is in

### response to your November 17, 1986 memorandum in which you requested comment on Region V's beliefthat PSD permits must contain short-term emission limits to ensureprotection ofthe NAAQS and PSD increments. I concur with 

### your position and emphasize that this position reflects our national policy." Memorandum from Emison, G., OAQPS, to D. Kee., Region V. November 24, 1986. 8. U.S. Environmental Protection Agency. Code of FederalRegulations. 

### Title 40, Chapter I, Subchapter C, Part 51.166(0). July 1, 1991. 9. U.S. Environmental Protection Agency. Workbookfor Estimating Visibility Impairment. 

### Office ofAir Quality Planning and Standards, Research Triangle Park, NC. EPA-450/4-87-031. November 1980.

10-14 April 1993

### 10.4 SIP PERMIT REQUIREMENTS In addition to the special major somcepermitrequirements listed above, SIP permit requirements are specified in 40 CPR Part51.165(b). Theserequirements govern the permitting ofmajor new and modified sources in attainment and unclassifiable areas where NAAQS violations existor are discovered as part ofthe permitting analysis. Essentially, whatis required for PM-lOisthata source demonstrate thatits ambient impact would be less than the PM-lO air quality significance levels in all areas and for all time periods where PM10 NAAQS violations are or will occur.' Itis not necessary to demonstrate an insignificant impacteverywhere in the impact area. The 40 

### CFR Part 165(b)(3) requirements also provide for sources that do cause or contribute to PM-lO violations (i.e., cannot demonstrate insignificance at noncomplying receptors)
. In such situations, sources may devise PM-lO emission reductions to offsettheir ambient impacts. The particular ambient criteriathatmustbe satisfied to conform to 

### SIP provisions developed pursuant to 40 CPR Part 51.165(b) must be discussed with the reviewing agency and reflect local plans for maintenance and attainment ofthe PM-lO NAAQS.

10-15 April 1993

### REFERENCES FOR SECTION 10.4

1. 

### "I believe the most appropriate course ofaction to follow is the second approach which considers the significant impact ofthe source in a way thatis spatially and temporally consistent with the predicted violations." Memorandumfrom Emison, G.A., OAQPS, to T.S. Maslany, Air

### ManagementDivision, Region ill. 

### July 5, 1988.

10-16 April 1993

### 10.5 VISmn..ITY With respectto visibility protection, PSD permitreviews fornew ormodified major stationary sources mustprovide for the following:

• Written notification (including the visibility analysis) ofFLMs ofany affected Federal Class I areas within 30 days ofreceipt ofand atleast 60 days prior to public hearing or, in cases where the

-reviewing agencyreceives advance notification (e.g., 

### early consultation with the source prior to submission ofthe application), written notification shall be provided to the affected FLM(s) within 30 days ofsuch advance notification
• Consideration ofany analysisperformed by the FLM that is provided within 30 days ofwritten notification as specified above and concludes that the proposed new major stationary source ormajor modification may have an adverse impact on visibility in any Federal Class I area. Where the reviewing agency finds that such an analysis does not demonstrate to the satisfaction ofthe State that an adverse impact will resultin the Federal Class I area, the State must, in the notice ofpublic hearing, either explain its decision or give notice as to where the explanation can be obtained New source review with respectto visibility protection mustprovide for review ofany new major stationary source ormajor modification that:

• Has an impact on any integral vista ofaFederal Class I area, ifthe vista is identified in accordance with 40 CPR Part 51.304 by the FLM at least 12 months before submission ofa completepermit application (or within 6 months ifthe FLM has provided notice and opportunity for public comment)
• Proposes to locate in an area classified as nonattainment under section 107(d)(l)(A)(B)(C) ofthe Act but which may have an impact on visibility in any Federal Class I area States may also require monitoring ofvisibility in any Federal Class I area near the proposed new stationary source or major modification. All new source reviews with respect to 

### visibility shall be performed in accordance with 40 CFR Part 51.320 and 40 CFR Part 52.24 and must ensure that the source's emissions will be consistent with making reasonable progress toward the national visibility goal referred to in40 CPRPart 51.300(a).

10-17 April 1993

### 10.6 EMISSIONS TRADING

10.6.1 General Policy Aspects Emissions trading consists ofbubbles, netting, offsets, and emission reduction banking. These trading alternatives do not alter existing 

### air qualityrequirements (e.g., 

### this policy and guidance does not affectthe applicable NSR/PSD rules for offsetting and netting). Still, these trading alternatives provide flexibility to States and industry in meeting theirrequirements. Emission trading can result 

### in reduced costs and faster compliance with applicable regulations. Any use ofbubbles, banking, or similar emissions trading provisions must be approved by the EPA as a SIP revision or must be approved by the State under an EPA approved generic bubble rule. A summary ofemissions trading alternatives follows. l



### 10.6.2 Bubbling EPA's bubblepolicy lets existing plants (or groups ofplants) increase emissions at one or more emission sources in exchange for compensating extra decreases in emissions at other emission sources. To be approvable, each bubble mustproduceresults which are equivalentto or better than the baseline emission levels in terms ofambient impact and enforceability. Thus, bubbles shouldjeopardize neither ambient standards nor applicable PSD increments and visibility requirements. Under EPA's bubble policy, emissions reductions from existing sources can not be used to meet technology-based requirements applicable to new or modified stationary sources.2



### 10.6.3 Netting Netting refers to the policy by which EPA may exempt "modifications" ofexisting major sources from certain preconstruction permitrequirements under the New Source Review (NSR) program, so long as there is no net emissions increase within the major source or any such increase falls below significance levels. By "netting out," the modification is not considered "major" and is therefore not subject to associated preconstruction permit requirements for major modifications under 40 CFR 51.18, 52.21, 52.24, 52.27, or 52.28.
10-18 April 1993The modi!ication mustnevertheless meet applicable NSPS, NESHAPs, preconstruction applicability reviewrequirements under 40 CFR 51.18(a)-(h) and (1), and SIPrequirements.3 However, 

### in addition to these Federal,definitions'for majornew sources and modifications, Statepreconstructionpermits for major or minor new**~ources** and modifications may be required under40 CFR 51.18(a), and some States preclude netting.



### 10.6.4 Offsets In nonattainment areas, major new stationary sources and major modifications are subject to a preconstructionpermit requirement thatthey obtain enough emissionreductions to more than "offset" their emissions. This requirement is designed to allowindustrial growth 

### in nonattainment areas without interfering 

### with attainment and maintenance ofthe**NAAQS~4**


### 10.6.5 Banking Firms may store or bank qualified emission reduction credits (ERC's) in EPAapprovable banks for later use in bubble, offset or netting transactions. Depending on the bank's rules, banked ERe's may also be sold ortransferred to other firms which seek to meet certain regulatory requirements by use ofemissions trades.5



### 10.6.6 Emission Reduction Credits Emission reduction credits are the common currency ofall trading activity. To ensure that emission trades do notcontravenerelevantrequirements ofthe Act, only reductions which are surplus, enforceable, permanent, and quantifiable can qualify as emission reduction credits and be banked orused in an emissions trade.

10-19 April 1993 •

### REFERENCES FORSECTION 10.6

1. 51 Federal Register43,824-25 (December 4, 1986), Emissions Trading Policy Statement; General Principles for Creation, Banking and Use ofEmission Reduction Credits; Final Policy Statements and Accompanying Technical Issues Document 2. 51 Federal Register 43,830 (December 4, 1986), Emissions Trading Policy Statement; Introduction: Basic Elements ofEmissions Trading; The Bubble. 3. 51 Federal Register43,830 (December 4, 1986), Emissions Trading Policy Statement; Introduction: Basic Elements ofEmissions Trading; Netting. 4. 51 Federal Register43,830-31, (December 4, 1986), Emissions Trading Policy Statement; Introduction: Basic Elements ofEmissions Trading; Emission Offsets. 5. 51 Federal Register 43,831 (December 4, 1986), Emission Trading Policy Statement; Introduction: Basic Elements ofEmissions Trading; Emission Reduction Banking.

10-20 April 1993

### 10.7 PM-lO SPECIFICPOLICYASPECTS Generally, an emissionstIading applicantnmsHiemonstrate-

### that the-pwposecttrades will notcause an increase inbaseline emissions. The baseline emission depends upon the type ofareain which the source operates. Usually, an air quality demonstration for PM-I0 using ambientdispersion modeling isrequired. l
The emissions trading policy offers four alternatives States can follow to evaluate whether any bubble oroffsetis approvable: 

### 1. DeMinimis. In general, no modeling isneeded to detennine the ambient equivalence to trades in which applicable netbaseline emissions do notincrease and in which the gross sum ofthe emissions increases, after applicable controlrequirements, total less than 25 tpy for particulate matter.2
2. Level I. In general, no modeling is needed to determine ambientequivalence if:

a. The trade does not result in an increase in applicable net baseline emissions b. The relevant sources are located in the same vicinity (within 250 meters ofeach other)
c. No increase in baseline emissions occurs in the source with the lower effectiveplume height as determined under EPA's 

### Guidelines onAirQuality Models d. No complex terrain is within the area ofsignificantimpact ofthe trade or 50 kilometers, whichever is less
e. Stacks with increasing baseline emissions are tall enough to avoid possible downwash situations, as determined by the formula at 50 Federal Register 27,892 (July 8, 1985) f. The trade does not involve open dust sources 

### 3. Level

## n. Bubble trades which are neither 

### de minimis nor Level 

### I may nevertheless be evaluated for approval based on modeling to determine ambient equivalence limited solely to the impacts ofthe specific emission sources involved in the trade, if: ( 1)
10-21 April 1993there is no increase in applicable net baseline emissions; (2) the potential change in emissions before and after the trade 

### will notcause a significant increase in pollutant concentrations at any receptor for any averaging time specified

### in

### an applicable ambient air quality standard; and (3) such an analysis does notpredict any increasein ambient concentrations in a mandatory Federal Class I area. The definition of "significant" as used above can be found in the Emission Trading Policy Federal Register Notice, 51 FR43845 (December 4, 1986), footnote 38. 

### 4. Level

### ID. Full dispersion modeling considering all sources affecting the trade's area ofimpactis required to determine ambient equivalence ifapplicable net baseline emissions will increase as a result ofthe trade, or ifthe trade cannotmeetcriteria for approval under 

### de minimis, Level 

### I or Level 

### 11.3 See Section 7.9 ofthis guideline for discussion on stackheight emissions balancing policy
.

10-22 . April 1993

### REFERENCES FOR SECTION 10.7

1. "Bubble applicants must show thattheir proposed trades are at least equivalentin ambient effectto the SIP emission limits the bubble would replace. For some criteria pollutants (e.g., VOC orNOx) this test may generally be metby showing equal reduction in emissions. For otherpollutants (e.g., 

### S02, TSP, or CO) itwas traditionally met, prior to the 1982 policy, through ambient dispersion modeling." 51 Federal Register43,827 (December4. 1986), Emissions Trading Policy Statement; General Principles for Creation. Banking and Use ofEmission Reduction Credits; Final Policy Statements and Accompanying Technical Issues Document. 2. 51 Federal Register 43,828 (December 4, 1986). Emissions Trading Policy Statement; General Principles for Creation, Banking and Use ofEmission Reduction Credits; Final Policy Statements and Accompanying Technical Issues Document. 3. 51 Federal Register 43.844-5. (December4, 1986), Emissions Trading Policy Statement; General Principles for Creation, Banking and Use ofEmission Reduction Credits; Final Policy Statements and Accompanying Technical Issues Document

10-23 April 1993 

## r

### 11.0 COMPLIANCE AND ENFORCEMENT

11.1 GENERAL Implementation and enforcementprovisions mustbeincluded in a SIP to show how the requirements ofthe plan will beputinto effect and how sources that are inviolation of the plan'srequirements will be brought into compliance. Therefore, the emission limits and other requirements must (1) be written so that they are enforceable; (2) mustrequire continuous compliance with the SIPprovisions and with the NAAQS; (3) must include provisions for monitoring, testing, and recordkeeping and reporting to determine compliance; and (4) mustinclude specific, expeditious final compliance data!



### 11.2 ENFORCEABILITY CRITERIA To be enforceable, the wording ofSIPregulations must unambiguously describe what facilities are affected by the rule and what they are required to do to be in compliance. The requirements should be within the statutory authority ofthe regulatory agency and, in all cases, the owner or operator ofa source should be aware ofthe standard ofconductrequired by the regulation? A SIP regulation should address the following issuesrelated to enforceability.3
Applicability
• What sources are being regulated?
• What are the criteriafor exemption?
• Is the calculation procedure for exemption clearly specified?
• Is the emission inventory listed in the background document ofthe attainment demonstration?
• Is the averaging time(s) used in the rule differentfrom that ofthe ambient standard?
• Whatare the units ofcompliance?
11-1 April 1993• Is.bubbling or averaging ofany type allowed? Ifyes, state criteria. Could a U.S. EPA inspectorindependently determine ifthe criteria were met? Does EPA have to approve each case?
• Ifthere is a redesignation, will this change the emission limitations? 

### Ifyes, which ones and how? Compliance Dates
• Whatis the attainment date?
• Whatis the date by which compliance is expected (or the date on which noncompliance will be considered a violation ofthe rule) Specificity ofConduct
• Whattestmethod is required to determine compliance?
• Whatis the averaging time in compliance test method?
• Is a compliance calculation or evaluation required? Ifyes, listthe fonnula, period of compliance, and/or evaluation method. Incorporation by Reference
• Whatis State authority for rulemaking?
• Are methods/rules incorporated byreference in the right manner? Record Keeping
• Whatrecords are required to determine compliance?
• In what fonn or units must the record be kept? On what time basis?
• Does the rule affIrmatively require that the records be kept? Exemption
• What are the allowable exemptions?
• Is the criteriafor application clear? Malfunction Provisions
• Whatexceedance may be excused? 11-2 April 1993• How is the standard to be applied?
• Who includes the determinations? Any exemptions to the regulation should be clearly stated in the text ofthe regulation. For example, exemptions based onthe size ofthe facility or on the emission levels from a source should state explicitly how the owner or operator ofthe source is to determine size and emission level (e.g., whether emissions are actual or design emissions and how actual emissions are calculated). In addition, provisions ofaregulation that allow for variations in the normal mode ofcompliance should be clearly specified. These variance provisions should also make clear whether case by case approval from EPA isrequired in orderto qualify for the variance, or whether there is general approval.4 Ifthe SIPregulation includes provisions ofFederalregulations that are incorporated byreference, the wording ofthose Federalregulations should be examined to determine their appropriateness and relevance. To allow for future changes to thereferenced Federal regulations, the SIPregulation could reference the current version ofthe Federal regulation or any subsequentversion promulgated by EPA. The SIP regulations should explicitly state recordkeeping and reporting requirements. They should describe the records that are to bekept to demonstrate compliance, how long and where the records are to be maintained, accessibility for inspection, and schedules and content requirements for any required reports. Wheneverpossible, the SIP should specify the form and format ofreports or itshould give an example of an acceptable report. The SIP regulations should be written so that failure to submit arequired report is itselfa violation of ' the regulations.

11-3 April 1993

### REFERENCES FOR SECTION 11.2

1. "Eachplan mustprovide for monitoring the status ofcompliance with any rules and regulations that setforth anyportion ofthe control strategy. Specifically the plan mustmeetthe requirements ofthis subpart." U.S. Environmental Protection Agency. 

### Code of FederalRegulations. Title 40, Chapter I, Subchapter 

### K. July 1, 1991. 2. "The notion ofenforceability encompasses severalconcepts. At the most basic level, a regulation must be within the statutory authority ofthe promulgating agency." Memorandumfrom Alushin, M.S., Associate Enforcement Counsel for Air Enforcement, 

### et. al. to Regional Administrators. Regions I-X, 

### et. al. Review ofState Implementation Plans and Revisions for Enforceability and Legal Sufficiency. September 23, 1987. (PN 113-87-09-23-041) 

### 3. "One critical function that your offices performis to assure thatregulations developed for stationary sources by the States underthe Clean Air Act are enforceable and legally sufficient Ourregulations require that the state implementation plans ("SIP's") must "be adopted as rules and regulations enforceable (emphasis added) by the State agency" [40 CPR 51.281 (1987)]. We are concerned thatreview ofSIP'sfor enforceability has not been receiving adequate attention. The Agency sometimes experiences difficulties in its efforts to enforce the currentrules because they are not sufficiently clear. The Regional Offices are at the forefront ofthe Federal SIP approval process. The purpose ofthis memorandum is to remind you ofthe importance ofdoing the review necessary to assure that all SIP plans and revisions are enforceable and 

### in conformance with the Act. Please do not forward for approval SIP's which fail to satisfy the enforceability criteriain this memorandum. Memorandumfrom Alushin, M.S., Associate Enforcement Counsel for Air Enforcement, 

### et. al. to Regional Administrators. Regions I-X, et. 

### al. Review of State Implementation Plans and Revisions for Enforceability and Legal Sufficiency. September 23, 1987. (PN 113-87-09-23-041) 4. "Yourreview should ensure that the rules in question are clearly worded and explicit in their applicability to the regulated sources." Memorandum from Potter, J.C., OAR, Adams, T.L., Jr., OECM, and Blake, ES., General Counsel to Regional Administrators, Regions I - X, et

### al. September 23, 1987. (PN 113-87-09-23-041)

11-4 April 1993 

# ,.

### 11.3 CONTINUOUS COMPLIANCE

11.3.1 General As a generalrule, sources are required to meet all 

### applicable emission limitations and other control requirements incorporated into a SIP regulation at all times. Continuous compliance means that excess emissions should be avoided by properdesign, operation, and maintenance ofair

### pollution sources and air

### pollution control equipment.l



### 11.3.2 EnforcementDiscretion Approach The enforcementdiscretion approach allows the enforcing agency to determine whether emission limit
. violations are cases which do notrequire enforcement actions. In these situations, the**~ource** 

### is responsible for proving that enforcement action would be inappropriate. An advantage to this approach is that by using enforcement discretion, an agency encourages sources to establish and follow proper operating and maintenance procedures. Properprocedures help to minimizeperiods ofexcess emissions.2 If

### a malfunction occurs such that bypassing pollution control equipment will prevent death, personal injury, or severeproperty damage, the pollution control agency can consider specific circumstances before choosing to take enforcement action. During such a malfunction or emergency situation, the owner or operator ofthe pollution source is expected to minimize and eliminate emission limit exceedances as quickly as possible. When an emission exceedance occurs in emergency situations, the source owner or operator is responsible for proving that the excess emissions resulted from a true malfunction (i.e., 

### unpreventable, unavoidable).3 Some SIP'sprovide for an automatic emission limitation exemption during periods of excess emission due to startup, shutdown, maintenance, ormalfunction
. "Excess emission" means an air 

### emission rate which exceeds any applicable emission limitation. "Malfunction" means a sudden and unavoidable breakdown ofprocess or control equipment. Generally, EPA agrees that imposing apenalty for sudden and unavoidable malfunctions caused by circumstances entirely beyond the control ofthe owner and/or operator is not appropriate.
11-5 April 1993However, any activity which can be foreseen and avoided, orplanned. is not within the definition ofa sudden and unavoidable breakdown. SIPprovisions concerning malfunctions mustbe clearly defined. SIP's may, however, omit any specialprovisions for malfunctions:'

11.3.3 Malfunctions and Unusual Start-up or Shut-down Any activity orevent which can be foreseen and avoided fans outside ofthe definition of sudden and unavoidable breakdown ofequipment. For example, a sudden breakdown which could have been avoided by better operation and maintenance practice is not a malfunction. In such cases, the control agency mustenforce violations ofthe emission limitation. A SIP cannotprovide an automatic exemption where a malfunction is claimed by a source.5 Startup and shutdown ofprocess equipment are part ofthe normal operation ofa source and should be accounted for in the planning, design, and implementation ofoperating procedures for theprocess and control equipment. Therefore, itis reasonable to expect that careful and prudentplanning and design will eliminate violations ofemission limitations during startup and shutdown. However, for a few sources there may existinfrequent short periods ofexcess emissions during startup and shutdown which cannot be avoided. Excess emissions during these infrequent shortperiods do nothave to be treated as violations providing thatthe source adequately shows that the excess could not have been prevented through careful planning and design and that bypassing ofcontrol equipmentwas unavoidable to preventloss oflife, personal injury, or severeproperty damage. Scheduled maintenance is a predictable event which can be scheduled atthe discretion ofthe operator and therefore, be made to coincide with maintenance on production equipment or otlier source shutdowns. Therefore, excess emissions during periods ofscheduled maintenance should be treated as a violation unless a source can demonstrate that such emissions could not have been avoided through better scheduling for maintenance or through better operation and maintenance practices.

11-6 April 1993

### REFERENCES FORSECTION 11.3

1. "In the strictlegal sense, sources arerequired to meet, without interruption, all applicableemission limitations and controlrequirements, unless suchlimitations
. specificallyprovide otherwise." Memorandumfrom Bennett, K.M., OANR, to Directors, Air and Waste ManagementDivisions and 

### AirManagementDivisions, Regions 

### I-X. Definition of "Continuous Compliance and Enforcement ofO&M Violations." June 21, 1982. 2. "EPA can approve SIPrevisions which incorporate the enforcement discretion approach." Memorandum from Bennett, K.M., OANR, to Regional Administrators, Regions 

### I-X. Policy on Excess Emissions During Startup, Shutdown, Maintenance, and Malfunctions. September 28, 1982. (PN 113-83-02-15-017). 3. "Therefore, during this latter situation, ifeffluent gases are bypassed which cause an emission limitation to be exceeded, this excess need not be treated as a violation ifthe source can show that the excesses could nothave been prevented through careful and prudentplanning and design and thatb'ypassing was unavoidable to preventloss of life, personalinjury, or severe property damage." Memorandum from Bennett, K.M., OANR, to Regional Administrators, Regions 

### I-X. Policy on Excess Emissions During Startup, Shutdown, Maintenance, and Malfunctions. February 15, 1983. (PN 113-83-02-15-017) 4. "Several ofthe existing State implementationplans (SIP's) provide for an automatic emission limitation exemption during periods ofexcess emissions due to startup, shutdown, maintenance or malfunction." Memorandumfrom Bennett, K.M., OANR, to Regional Administrators, Regions 

### I-X. Policy on Excess Emissions During Startup, Shutdown, Maintenance, and Malfunctions. September28, 1982. (PN 113-83-02-15-017). 5. "If a SIP contains a malfunction provision, itcannot be the type that provides for automatic exemption where a malfunction is alleged by a source." Memorandumfrom Bennett, K.M., OANR, to Regional Administrators, Regions 

### I-X. Policy on Excess Emissions During Startup, Shutdown, Maintenance, and Malfunctions. September 28, 1982. (PN 113-83-02-15-017).

11-7 April 1993

### ll.4 COMPLIANCE MONITORING

ll.4.1 Compliance Monitoring Strategy The ComplianceMonitoring Strategy (CMS) provides a flexible approach for detennining State inspection commitments. The eMS stresses flexibility with accountability. This strategy recommends the development ofa comprehensive inspection plan that identifies all the sources in a source category committed to beinspected by the State agency during the fiscal year. The objectives ofthe CMS are as follows:

• To identify monitoring objectives vis-a-vis availableresources through the development ofan inspectionplan
• To ensure effective national oversight ofthe air compliance monitoring program, to permitits evaluation, and to establish a feedback mechanism
• To ensure emission standards are met through effective compliance monitoring activitiesI
11.4.2 

### Compliance Monitoring Requirements The EPA regulations require SIP's to containlegally enforceableprocedures to require stationary sources to install and operate equipmentfor continuously monitoring, recording and reporting emissions [40 CFR 51.214(a)]? The SIP should identify the types ofsources (by source category and capacity) that mustinstall, maintain, and operate the equipment; the planned use ofdata; calculations, recordkeeping, reporting, and qUality assurance procedures; and thepollutants that must be monitored [40 CFR 51.214(b)V Industries and control agencies benefitfromroutinely monitoring emissions, keeping records and periodic reporting. Thebenefits include increased cost-effectiveness by increasing the sources' energy efficiency and through pollution prevention and better targeting of "problem sources".4 Continuous emission monitoring systems (CEMS) provide the best means for directly determining source compliance with emissionregulations. In some situations, CEMS technology might notbe feasible, in which case a,lternative methods of compliance might be necessary. These alternative technologies might include instrumental monitoring ofprocess parameters, such as, temperature, pressure, and voltage. Where 11-8 April 1993

### instrumental or manual continuous emission monitoring is notfeasible, manual monitoring of process infonnation such as pressure drop reading would be acceptable. Currently, there are no CEMS available for PM-lO.s 

### Wherever feasible, CEMS should be 

### the required method for monitoring emissions from a source. This is particularly true for major sources and for sources located in nonattainment areas. CEMS should be used to monitor the continuous compliance ofNSPS and PSD sources in attainment areas. Whereveritis technically feasible, CEMS requirements should also be incorporated into NSR preconstructionreviews, operating permits, and resolution ofenforcement actions.6 

### EPA also intends to require the use ofCEMS at all major sources required to have permits under Title V and those subjectto NESHAPS regulations.7 

### EPA regulations require SIPrevisions to require source-continuous monitoring to determine compliance for some types of sources [40 CFR Part 51, Appendix Pl. These sources includepower plants, sulfuric acid plants, and FBCcatalytic cracking unit regenerators atpetroleumrefineries that exceed size thresholds
. If

### a State does nothave plants that meet these qualifications, these provisions need not be included in the SIP. The State, however, should submit a certification with the SIP'thatthere are no plants meeting these specifications. Many States require CEMS on major sources, such as pulp and paper plants and smelters. The primary purposes ofrequiring such monitoring are to assure that the source (I) has timely and accurate compliance data; (2) has a quantitative basis to monitor emissions changes which are caused by process orcontrol equipmentchanges (e.g., 

### so the source is able to modify maintenance procedures); and (3) can minimize energy and raw productuse rates by using infonnation made available by the CEMS. Such monitoring measurably helps agencies ensure continuous compliance and allows them to targetresources for the sources' which violate their emission limits.6



### 11.4.3 StateInspection Plan Submittal Each inspection plan submittal will present how that State will address national priorities and willjustify exceptions to the national priorities. The plan will also identify

11-9 April 1993

### specific sources to be

### inspected, allocate the total inspection budget among source groups, and cover otherissues that are necessary to meet the eMS objectives and requirements. The targeting model should be 

### used to determine Group I and Group IT sources to be included in this inspection plan, in 

### addition to, theirpriority ofinspection. 1 

### The above steps will allow the State agency to develop their initial comprehensive inspection plan which will 

### be submitted to the EPA Region for review. Tojustify exceptions to national priorities, the State must submit the basis for their decisions, such as the inspection targeting model inputs and results.8



### 11.4.4 Negotiated Inspection Plans State agencies areresponsible for providing information and for running the inspection targeting model where applicable. State agencies are also responsible for meeting the commitments oftheir negotiated inspection plans. Finally, the State agencies are responsible for ensuring the appropriate data are reported in a timely and complete fashion to the Regional Office or directly into AIRS.9 When preparing an inspection plan submittal, itis recommended that the State use the inspection targeting model for ranking Group I sources and those Group IT sources that may be substituted for Group I 

### source inspections on a State-widelevel. The inputs and results are then presented at the inspection plan negotiation meeting with EPA.6

11-10 

### April 1993

### REFERENCES FORSECTION 11.4

1. Memorandum. John Rasnic, Acting Director, Stationary Source Compliance Division, OAQPS, U.S. EPA, Washington, D.C., to Air

### ManagementDivision Directors, Regions I, ill, 

### and IX; Air 

### and Waste ManagementDivision Director, Region TI; Air. 

### Pesticides, and Toxics Management Division Directors, Regions IV and VI; Air 

### and Toxics Division Directors, Region

## vn,.VIII, X; and Air and Radiation Division Director, Region V. RevisedComplianceMonitoring Strategy. 

### March 29, 1991. 2. "Theplan must contain legally enforceable procedures to
- (1) 

### Require stationary sources subject to emission standards as part ofan applicableplan to install, calibrate, maintaln, and operate equipment for continuously monitoring and recording emissions." U.S. Environmental Protection Agency, Code of FederalRegulations. 

### Title 40. Chapter I, Subchapter C, Part 51.214(a). July 1, 1991. 3. "Theprocedures must
- (1) Identify the types ofsources, by source category and capacity, that must install the equipment; and (2) Identify for each source category the pollutants which must be 

### monitored." U.S. Environmental Protection Agency, Code of FederalRegulations. 

### Title 40. Chapter I, Subchapter C, Part51.214(b). July 1, 1991.
4. "EPA recognizes the value ofroutinely monitoring emissions, keeping records, and requiring periodic reporting from major stationary sources. EPA believes such monitoring is ofgreat benefit both to industry in pollutionprevention and energy minimization and to control agencies in continuous compliance and targeting of "problem sources." Letter from William K. Reilly, U.S. EPA, OAQPS, Washington. D.C., to John D. Dingell, Chairman, Subcommittee on Oversight and Investigations, Committee on Energy and Commerce, House ofRepresentatives, Washington, D.C. April 10, 1991. 5. "While EPA considers continuous emission monitoring systems (CEMS) to be the most useful means ofdirectly determining source compliance with emission regulations, the agency also recognizes the need to rely on the application ofother means ofcontinuous monitoring. These include instrumentalmonitoring ofprocess parameters such as temperature, pressure, and voltage, and manual monitoring of process infonnation such as the number ofgallons and chemical analysis of specific paints used to coat automobiles. These alternative continuous monitoring techniques are appropriate in situations where the technology does notexistfor CEMS or the application oftechnology is notfeasible. Letterfrom William K. 

### Reilly, U.S. EPA, OAQPS, Washington, D.C., to John D. Dingell, Chairman, Subcommittee on Oversight and Investigations, Committee on Energy and Commerce, House of Representatives, Washington, D.C. April 10, 1991.

ll-ll 

### April 19936. "This states the OAQPS policy, which is effective immediately, on the use ofCEM data and provides guidance as to how that policy should be implemented." Memorandumfrom Emison, G.A.,**OAQPS~**toAirManagementDivision**Direc~** Regions I, 

### ill, and IX, Air and Waste Management Division Director, Region IT, Air, Pesticides and Toxics Management Division Director, Regions VIT,

## vrn, and X, Air and Radiation Division Director, Region V. March 31, 1988. (pN 113-88-03-31-048) 7. "EPA intends to require the use ofcontinuous monitoring atall "major" sources required to have permits underTitle V and those subject to new orrevised NSPS and NESHAPS regulations, including those defined by the Clean 

### AirActAmendments of 1990." Letter from William 

### K. Reilly, U.S. EPA, OAQPS, Washington, D.C., to John D. Dingell, Chairman, Subcommittee on Oversight and Investigations, Committee on Energy and Commerce, House ofRepresentatives, Washington, D.C. April 10, 1991. 8. Memorandum. John S. Seitz, Director, Stationary Source ComplianceDivision, OAQPS, U.S. EPA, Washington, D.C., to Air Management Division Directors, Regions I, ITI, and IX; Air and Waste Management Division Director, Region IT; Air, Pesticides, and Toxics ManagementDivision Directors, Regions IV and VI; Air and Toxics Division Directors, Region VII,

## vm, X; and Air and Radiation Division Director, Region V. ComplianceMonitoring Strategyfor FY89. March 31, 1988. (PN 114-88-31-006). Inspections, Monitoring, and Entry. 9. "The tracking system for CMS stationary sources in Group I is the AIRS/AFS system. As Group II sources are substituted for Group I sources, they are to be entered and subsequently tracked in AIRS/AFS as well
... In addition, States are responsible for meeting the negotiated commitments, providing the necessary information to the Regional Office to both negotiate the reference level and enable the Regional Office to conductthe evaluation at the end ofthe year, reporting inspections in a timely manner to the Regional Office, ordirectly into AFS, and keeping Regional Office staff informed ofproblems as well as successes in the implementation ofCMS." Memorandumfrom John Rasnic, Acting Director, Stationary Source Compliance Division, OAQPS, U.S. EPA, Washington, D.C., to Air ManagementDivision Directors, Regions I, ill, and IX; Air and Waste ManagementDivision Director, Region II; Air, Pesticides, and Toxics Management Division Directors, Regions IV and VI; Air and Toxics DivisionDirectors, Region VII,

## vrn, X; and Air and Radiation Division Director, Region V. Revised ComplianceMonitoring Strategy. March 29, 1991.

11-12 April 1993

### 11.S 

### COMPLIANCE PLANS/SCHEDULES The EPA regulations require each SIPto contain legally enfOrceable compliance schedules that setforth the dates by which all stationary and mobile sources orcategories must be in compliance with the SIP [40 CFR 51.260(a)]. Compliance plans/schedules should include enforceable milestones, stipulatedpenalties, final compliance dates, and compliance test method. The compliance schedules containedin the SIP mustprovide for attainment of compliance with the primary standards as soon as practicable, orno laterthan a specified date [40 CFR 51.26 l(a)].



### 11.6 COMPLIANCE TESTING METHODS In accordance with the requirements ofSubpart K ofTitle 40, Chapter I, Part 51 of the Code ofFederalRegulations, 

### each SIP must provide for monitoring the status of compliance with any rules and regulations that set forth any portion ofthe control strategy, specifically for testing and enforcement. The plan must provide for periodic testing and inspection ofstationary sources and enforceable test methods for each emission limit specified in the plan.1 

### Appendix M ofTitle 40, Chapter I, Part 51 ofthe Code ofFederalRegulations 

### recommends two test methods, Method 201 and 20lA, for the determination ofPM-lO emissions in the preparation ofState implementation plans.2 

### Method 201 is based on an exhaust gas recycle procedure, and applies to the in-stack measurement ofparticulate matter ofa size less than or equal to that ofPM-lO emitted from stationary sources. In this method, a gas sample is isokinetically extracted from the source. An in-stack cyclone is used to separate particulate matter larger than PM-lO, and an in-stack glass fiber filter is used to collect the PM-lO. To maintain isokinetic flow rate conditions at the tip ofthe probe and a constant flow rate through the cyclone, a clean, dried portion ofthe sample gas at stack temperature is recycled into the nozzle. The particulate mass is determined gravimetrically after removal ofuncombined water. Method 201A, based on a constant sampling rate procedure, applies to the in-stack measurement ofparticulate matter ofa size less than or equal to that ofPM-lO emitted from stationary sources.2 

### In this method, a gas sample is extracted at a constant flow rate through
11-13 

### April 1993

### an in-stack sizing device, which separates PMlarger than PM-lO. Variations from isokinetic sampling conditions are maintained within well-defined limits. The particulate mass is detennined gravimetrically afterremoval ofuncombined water. Since condensible particulate matter (CPM) emissions form very fine particles in the PM-IO size range and are consideredPM-lO emissions, EPA added (to Appendix M ofTitle 40, ChapterI, Part 51 ofthe Code of FederalRegulations3) 

### a method202, for measuring CPM emissions from stationary sources. The method may be used in conjunction with Method 201 or 201A ifthe probes are glass-lined. The CPM is collected in the impinger portion ofaMethod 17 (Appendix A, 40 CFR Pan 60) type sampling train.4 

### The impinger contents are immediately purged after the run with nitrogen to remove dissolved sulfur dioxide gases from the impinger contents. The impinger solution is then extracted with methylene chloride. The organic and aqueous fractions are then taken to dryness and the residues weighed. The total ofboth fractions represents the CPM. Method 5 is another method used for the determination ofparticulate emissions from stationary sources.5 

### In this method, paniculate matter is withdrawn isokinetically from the source and collected on a glass fiber filter maintained at temperatures approved by EPA. The particulate mass, which includes any material that condenses at or above the filtration temperature, is determined gravimetrically after removal from uncombined water.

11-14 April 1993REFERENCES FOR SECTION 11.6 

### 1. "As an enforceable method, States may use: (1) 

### Any ofthe.appropriate.,

### methods.in. 

### appendix M to this part, Recommended Test Methods for State Implementation Plans; or (2) An alternative method following review and approval ofthat method by the Administrator; or (3) Any appropriate method in Appendix A to 40 CFR part 60." U.S. Environmental Protection Agency, Code ofFederalRegulations. 

### Title 40. ChapterI, Subpart K, Pan 51.212. July 1, 1991. 2. U.S. Environmental Protection Agency, Code ofFederalRegulations. 

### Title 40. ChapterI, Subchapter C, Pan 51, Appendix M. July 1, 1991. 3. 56Federal Register 65,433-9 (December 17, 1991), Preparation, Adoption, and Submittal ofState Implementation Plans, Method for Measurement ofCondensible Particulate Emissions from Stationary Sources. 4. U.S. Environmental Protection Agency, Code ofFederal Regulations. 

### Title 40, Chapter I, Subchapter C, Part 60, Appendix A. 

### July 1, 1991. 5. U.S. Environmental Protection Agency, Code ofFederalRegulations. 

### Title 40, Chapter I, Subchapter C, Part 60, Appendix A. 

### July 1, 1991.

11-15 

### April 1993
.

### 12.0 NEW SOURCE PERFORMANCE STANDARDS

U.l GENERAL Under section III ofthe Act, EPA isrequired to develop emission regulations for a category ofsources which "
...causes, orcontributes significantly to, air pollution whichmay reasonably be anticipated to endangerpublic health or welfare.III Theseregulations, referred to as new source performance standards (NSPS), are to reflect the degree ofemission reduction achievable through technology that has been adequately demonstrated, taking into consideration the cost ofthe emission reductions and any air quality, health, environmental and energyimpacts on meeting the standard.2
This chapter summarizesrelevantNSPS provisions (including emission limits,**complianc~** testing, and monitoring procedures) for several source categories that are significantemitters ofPM-lO. NSPS provisions are generally applicable to total particulate matter. At present, there are no NSPS provisions specific to PM-lO. NSPS particulate source categories generally include steam generators, smelters, petroleumrefineries, and new residential wood heaters. A complete list ofNSPS sources ofparticulate matter is included in Table 12-1. Relevant NSPS provisions for selected particulate matter source categories are discussed in Section 12.2. Aspects ofthe provisions for modifications and reconstructions are clarified in Section 12.3.

12-1 April 1993TABLE 12-1. NSPS PARTICULATE MATTER SOURCE CATEGORIES


### Part60 Subpart D: SubpartDa: Subpart Db: SubpartE: SubpartF: Subpart I: Subpart

### J: SubpartL: SubpartM: SubpartN: Subpart Na: Subpart 0: Subpart P: Subpart Q: 

### Subpart R: Subpart Y: SubpartZ: Subpart AA: Subpart AAa: Subpart BB: Subpart CC: Subpart DD: SubpartHH: Subpart LL: Subpart NN: Subpart PP: Subpart UU: Subpart AAA: Subpart 000: Subpart PPP: Source Category 

### Fossil-Fuel Fired Steam Generators Electric Utility Steam Generating Units Industrial-Commercial-Institutional Steam Generating Units Incinerators Portland Cement Plants Asphalt Concrete Plants Petroleum Refineries Secondary Lead Smelters Secondary Brass and Bronze Production Plants Basic Oxygen Process Furnaces (Primary Emissions) Basic Oxygen Process Steelmaking Facilities (Secondary Emissions) SewageTreatment Plants Primary Copper Smelters Primary Zinc Smelters Primary Lead Smelters Coal Preparation Plants Ferroalloy Production Facilities Steel Plants: Electric Arc Furnaces Steel Plants: Electric Arc Furnaces and Argon-Oxygen Decarburization Vessels Kraft Pulp Mills Glass Manufacturing Plants Grain Elevators Lime Manufacturing Plants Metallic Mineral Processing Plants Phosphate Rock Plants Ammonium Sulfate Manufacture Asphalt Processing and AsphaltRoofing Manufacture New Residential Wood Heaters Nonmetallic Mineral Processing Plants Wool Fiberglass Insulation Manufacturing Plants

12-2 

### April 1993

### REFERENCES FORSECTION 12.1 

### 1. U.S. Congress. Clean AirAct,as amended November 1990. 42 U.S.C 7401 

### etseq. Section 111(b)(I)(A). Washington, D.C. U.S. Government Printing Office. 2. U.S. Congress. CleanAir Act, as amended November 1990. 42 U.S.C. 7401 

### etseq. Section 111(a). Washington, D.C.**U.S~** GovernmentPrinting Office.

12-3 April 1993

### 12.2 NSPS PROVISIONS FORPARTICULATE MATTER

12.2.1 SubpartD--Fossil-Fuel Fired Steam Generatorsl 

### This subpart applies to fossil-fuel 

### fired steam generating units that commenced construction after August 17, 1971, and that have a heat input capacity greater than 250 MM Btu/hr. A fossil-fuel fired steam generating unit is defined as a furnace or boiler used in the process ofburning fossil fuel for the purpose ofproducing steam by heat transfer. For this source category, particulate matter emissions are limited to 43 nanograms perjoule (nglJ) (0.10 lb/MM Btu) heatinput derived from fossil fuel or fossil fuel and wood residue and 20 percent opacity (exceptfor one six-minuteperiod per hour ofnotmore than 27 percent opacity). Complianceis generally determined by Method 5 to determine the PM concentration at affected facilities without wetflue-gas-desulfurization (FOD) systems and Method 5B at affected facilities after FOD systems; the sampling time and sample volume for each run shall be at least 60 minutes and 0.85 dscm (30 dsct). Method 9 shall be used to determine opacity.



### 12.2.2 SubpartDa--Electric Utility Steam Generating Unit,sl This subpart applies to electric utility steam generating units that commenced construction after September 18, 1978, and thathave a design heat capacity greater than 250 MM Btu/hr. An 

### electric utility steam generating unit is defined as 

### a steam electric generating unit that supplies more than one-third ofits potential electric output and more than 25 MW 

### electrical output to any utility power distribution system for sale. Forthis source category, particulate matter emissions are limited to 13 

### nglJ (0.03 Ib!MM Btu) heat input derived from the combustion ofsolid, liquid, or gaseous fuel; 1percent ofthe potential combustion concentration when combusting solid fuel; and 30percent ofpotential combustion concentration when combusting liquid fuel. Opacity is limited to 20 percent. Compliance is generally determined by Method 5 to determine PM concentration at affected facilities without FOD systems and Method 5B at affected facilities after FOD systems; the sampling time and sample volume for each run shall be at least 120 minutes and 1.70 dscm (60 dscf). Method 9 shall be used to determine opacity.

12-4 April 1993

### 12.2.3 SubpartDb--Industrial-Commercial-InstitutionalSteam Generating Units3 

### This subpart applies to industrial, commercial, and institutional steam generating units that commencedconstruction, modification, orreconstruction after June 19, 1984, and that have a heatinputcapacity greater than 100 MM Btu/hr. The steam generating unitin this category is defined as a device that combusts any fuel or by-product/waste to produce steam or to heat water or any other transfermedium. Forthis category, particulate matteremissions are limited to the following: 1. For affected facilities which combustcoal or amixture ofcoal and other fuels and have an annual operating capacity of**~1O** 

### percent, PM emissions are limited to 22 ng/l (0.05 Ib/MM Btu) heatinput for affected facilities which combust coal or a mixture of coal and other fuels and have an annual operating capacity of**~**

### 10 percent, PM emissions are limited to 43 ng/J (0.10 IbIMM Btu) heat input for affected facilities which combustcoal or a mixture ofcoal and other fuels and have an annual operating capacity of$30 percent, PM emissions are limited to 86 ng/J (0.20 lb/MM Btu) heat input 2. For affected facilities which combust oil, PM emissions are limited to 43 ng/l (0.10 

### lb/MM Btu) heatinp.ut 3. For affected facilities which combust wood or amixture ofwood and other fuels and have an annual operating capacity >30 percent, PM emissions are limited to 43 ng/l (0.10 Ib/MM Btu) heatinput; for affected facilities which combust wood or a mixture ofwood and other fuels and have an annual operating capacity of**~30** 

### percent, PM emissions are limited to 86 ng/l (0.20 lblMM Btu) heat input 4. For affected facilities which combust solid waste or a mixture ofsolid waste and other fuels and have an annual operating capacity of**~1O** 

### percent, PM emissions are limited to 43 ng/l (0.10 lb/MM Btu) heat input; for affected facilities which combust solid waste or a mixture ofsolid waste and otherfuels and have an annual operating capacity of$30 percent, PM emissions are limited to 86 ng/J (0.20 lb/MM Btu) heat input. Compliance is determined by Method 5 to measure PM concentration at affected facilities without wet FOD systems and by Method 5B at affected facilities after wet FOD systems; Method 17 may be used atfacilities with or without wet scrubber systemsprovided the stack gas temperature does not exceed 1600 

### C (3200 

### F). Method 9 shall be used to determine opacity.
12-5 

### April 1993

### 12.2.4 SubpartJ--Petroleum Refineries4
This subpart applies to petroleumrefineries with fuel combustion devices that commenced construction after June 11, 1973, and with Claus sulfur recoveryplants (>20 long tons/day capacity) thatcommenced construction after October 4, 1976. Particulatematter emissions are limited to 1.0kg/lOOO kg (1.0 Ib/1000 lb) ofcoke burn-offin the catalyst regenerator (exception). Opacityis limited to 30percent (except for one six-minute average opacity reading in anyonehourperiod). Compliance is generally determined by Method 5B or SF to determine PM emissions and associated moisture contentfrom affected facilities without wet FGD systems; only Method 5B is to be used after wet FGD systems. Sampling time and sampling rate for each run shall be atleast 60 minutes and 0.015 dscm/min (0.53 dscf/min) (except that shorter sampling times may be approved by the Administrator when process variables or other factors preclude sampling for at least 60 minutes).



### 12.2.5 SubpartL--Secondary Lead**Smelter~** This subpart applies to potfurnaces with a charging capacity ofmore than 250 kg (550 lb), blast (cupola) furnaces, and reverberatory furnaces in secondary lead smelters that commenced construction or modification after June 11, 1973. A secondary lead smelter is defined as any facility producing lead from a landbearing scrap material by smelting to the metallic form. For blast and reverberatory furnaces, particulate matter emissions are limited to 50 mg/dscm (0.022 gr/dscm). Opacity is limited to 10 percentfor potfurnaces and to 20 percent for blast and reverberatory furnaces. Compliance is determined using Method 5 to determine the PM concentration during representative periods offurnace operation, including charging and tapping; the sampling time and sample volume for each run shall be at least 60 minutes and 0.90 dscm (31.8 dscf). Method 9 shall be used to determine opacity.



### 12.2.6 SubpartP--Primary CopperSmelters6 This subpart applies to dryers, roasters, smelting furnaces, and copper convertersin primary copper smelters that commenced construction or modification after October 16, 1974. A primary copper smelter is defined as any installation or any intermediate process engaged in the production ofcopper from copper sulfide ore concentrates through the use of
12-6 April 1993

### pyrometallurgical techniques. For this source category, particulate emissions are limited to 50 mg/dscm (0.022 gr/dscf). Visible emissions are limited to 20percent opacity. Compliance is detennined using Method 5 to determine PM concentration; sampling time and sampling volume for eachrun shall be at least60 minutes and 0.85 dscm (30 dscf). Method 9 shall be used to determine opacity.



### 12.2.7 SubpartQ--PrimaryZinc Smelters' This subpart applies to roaster and sintering machines in primary zinc smelters that commenced construction or modification after October 16, 1974. Aprimary zinc smelteris defined as any installation engaged in the production, or any intennediateprocess in the production, ofzinc or zinc oxide from zinc sulfide ore concentrates through the use of pyrometallurgical techniques. For this source category, particulate matter is limited to 50 mg/dscm (0.022 gr/dscf). Visible emissions are limited to 20 percent opacity. Compliance is determined using Method 5 to determine the particulate matter concentration; sampling time and sample volume for each run shall be at least 60
.minutes and 0.85 dscm (30 dscf). Method 9 shall be used to determine opacity.



### 12.2.8 SubpartR--Primary Lead Smelters8 

### This subpart applies to sintering machine, sintering machine discharge end, blast furnace, dross reverberatory furnace, electric smelting furnace, and converters in primary lead smelters that commenced construction or modification after October 16, 1974. A primary lead smelteris defined as any installation or any intennediate process engaged in the production oflead from lead sulfide ore concentrates through the use ofpyrometallurgical techniques. For this source category, particulate emissions are limited to 50 mg/dscm (0.022 gr/dscf). Visible emissions are limited to 20 percent opacity. Compliance is determined using Method 5to determine PM concentration; the sampling time and sample volume for each run shall be at least 60 minutes and 0.85 dscm (30 dscf). Method 9 shall be used to determine opacity.

12-7 April 1993

### 12.2.9 SubpartAAA--New Residential Wood Heaters This subpart applies to wood**he~**manufactured on orafter )aly 1, 1988, or soldat retail on or afterJuly 1, 1990. A wood heateris defined as an enclosed, woodburning appliance capable ofandintendedfor space heating and domestic waterheating thatmeets the following criteria: (1) an average air-to-fuel ratio in the combustionchamberless than 35:1; (2) a useable firebox volume ofless than 20 cubic feet; (3) a minimum burn rate less than 5 kg!hr; and (4) a maximum weight of

### 800kg. For affected facilities manufactured on or after July 1, 1988 or sold atretail on or after July 1, 

### 1990, which are equipped with catalytic combustors, particulate matter emissions are limited to a weighted average of5.5 g/hr; for affected facilities not equipped with catalytic combustors, emissions are limited to a weighted average of 8.5 g/hr. For wood heaters manufactured on or after July 1, 1990 or sold atretail on or after July 1, 1992, which are equipped with catalytic combustors, particulate matter emissions are limited to a weighted average of4.1 g/hr. For affected facilities which are not equipped with catalytic combustors,particulate matter emissions are limited to 7.5 

### gIhr. Compliance is deterniined using Method 28 to establish the certification test conditions and the particulate matter weighted emission values.

12-8 April 1993 

### ...

### REFERENCES FORSECTION 12.2

1. U.S. Environmental Protection Agency. Code of FederalRegulations. Title 40, Chapter I, Subchapter C, Part 60. SubpartD. July 1, 1991. 2. U.S. Environmental Protection Agency. Code of FederalRegulations. Title 40, Chapter 

### I, Subchapter C, Part 60. SubpartDa. July 1, 1991. 

### 3. U.S. Environmental Protection Agency. Code of FederalRegulations. Title 40, Chapter 

### I, Subchapter C, Part 60. SubpartDb. July 1, 1991. 

### 4. U.S. Environmental Protection Agency. Code of FederalRegulations. Title 40, Chapter 

### I, Subchapter C, Part 60. SubpartJ. July 1, 1991. 5. U.S. Environmental Protection Agency. Code of FederalRegulations. Title 40, Chapter 

### I, Subchapter C, Part 60. Subpart L. July 1, 1991. 6. U.S. Environmental Protection Agency. Code of FederalRegulations. Title 40, Chapter 

### I, Subchapter C, Part 60. SubpartP. July 1, 1991. 

### 7. U.S. Environmental Protection Agency. Code ofFederalRegulations. Title 40, Chapter 

### I, Subchapter C, Part 60. Subpart Q. July 1, 1991. 

### 8. U.S. Environmental Protection Agency. Code of FederalRegulations. Title 40, Chapter 

### I, Subchapter C, Part 60. Subpart R. July 1, 1991.

12-9 April 1993

### 12.3 MODIFICATIONIRECONSTRUCTION PROVISIONS
"Modification" refers to "anyphysiCalor operational change to an existing facility whichresults in an increase in the emissionrate to the atmosphere ofanypollutantto which a standard applies
... " as described in the NSPS general provisions. Some ofthe possible changes that do notqualify as modifications include (1) routine maintenance, repair, and replacement; (2) increases in productionrate not accompanied by capital expenditures; (3) increased capacity utilization; (4) fuel switching, provided that facility was originally designed to handle the new fuel; (5) addition ofair pollution control and related equipment; and (6) the change in ownership ofan existing facility.l "Reconstruction" generally includes "the replacement ofcomponents ofan existing facility to such an extent that (1) the fixed capital cost ofthe new components exceeds 50 percent ofthe fixed capital costthat would be required to construct a comparable entirely new facility, and (2) itis technologically and economically feasible to meetthe applicable standards
..." 2

12-10 April 1993

### REFERENCES FOR SECTION 12.3

1. 

### U.S. Environmental Protection Agency. Code of FederalRegulations. Title 40, Chapter I, Subchapter C, Part 

### 60.14. July 

### 1, 1991. 2. U.S. Environmental Protection Agency. Code of FederalRegulations. Title 40, Chapter I, Subchapter 

### C, Part

### 60.15. July 

### 1, 1991.



### 12-11 April 1993