United States
Environmental Protection
Agency
Office of Air Quality
Planning and Standards
Research Triangle Park NC 27711
EPA-450/2-79-001a
OAQPS No. 1.2-120
April 1979
Air
&EPA Guidelines Series
Example Control
Strategy for Ozone
Volume 1:
General Guidance for
Nonattainment Areas
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EPA-450/2-79-001a
OAQPS No. 1.2-120
Example Control Strategy
for Ozone
Volume 1:
General Guidance for
Nonattainment Areas
by
Association of Bay Area Governments
Hotel Claremont
Berkeley, California 94705
Contract No. 68-02-3001
Andrew T.Creekmore, Project Officer
Prepared for
U.S. ENVIRONMENTAL PROTECTION AGENCY
Office of Air, Noise, and Radiation
Office of Air Quality Planning and Standards
Research Triangle Park, North Carolina 27711
April 1979
EPA [
I',
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OAQPS GUIDELINE SERIES
The guideline series of reports is being issued by the Office of Air Quality Planning and Standards (OAQPS) to
provide information to state and local air pollution control agencies; for example, to provide guidance on the
acquisition and processing of air quality data and on the planning and analysis requisite for the maintenance of
air quality. Reports published in this series will be available-as supplies perm it-from the Library Services Off ice
(MD35), U.S. Environmental Protection Agency, Research Triangle Park, North Carolina 27711; or, fora nominal
fee, from the National Technical Information Service, 5285 Port Royal Road, Springfield, Virginia 22161.
Publication No. EPA-450/2-79-001a
OAQPS No. 1.2-120
ii
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TABLE OF CONTENTS
CHAPTER TITLE PAGE
LIST OF TABLES v
LIST OF FIGURES vi
GLOSSARY vii
1. INTRODUCTION 1-1
2. SPECIAL PROBLEMS OF PHOTOCHEMICAL OXIDANT CONTROL 2-1
Dynamics of Oxidant Formation 2-1
Characterization of Sources 2-2
Multiple Scales of Effect 2-3
Institutional/Regulatory Implications 2-3
References 2-5
3. INTERGOVERNMENTAL COORDINATION AND PUBLIC INVOLVEMENT 3-1
IN THE PLANNING PROCESS
Requirements of the Clean Air Act 3-1
State and Local Consultation Process 3-2
Determination of Responsibilities
Local Lead Agency Designation 3-4
Intergovernmental Coordination 3-5
Public Participation 3-6
References 3-9
4. GENERAL TECHNICAL APPROACHES 4-1
Various Levels of Analysis and the Corresponding 4-2
Analysis Elements
Level 1 Analysis 4-2
Level 2 Analysis 4-6
Level 3 Analysis 4-10
Summary of Various Approaches 4-12
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PAGE
4. General Guidelines for Technical Analysis 4-15
References 4-20
5. DETERMINING BASEYEAR OXIDANT CONCENTRATION 5-1
Interpretation of Air Quality and Ozone Standard 5-1
Determination of Design Value 5-2
References 5-3
6. EMISSION INVENTORY AND PROJECTION 6-1
Planning for Emission Inventory/Projection 6-2
Overview of Emission Inventory/Projection Process 6-5
Evaluation of Existing Emission Inventories 6-9
Determination of the Grid System 6-10
Data Collection 6-10
Data Analysis and Emissions Calculations 6-11
Spatial Resolution of Emissions 6-13
Temporal Resolution of Emissions 6-17
Emissions (VOC and NOX) Species Allocation 6-18
Emission Projections 6-18
Problems 6-19
Guiding Principles . 6-21
Overview of Projection Approaches 6-22
References 6-24
7. OXIDANT PREDICTION METHODS 7-1
Level 1: Photochemical Dispersion 7-1
Models - Grid or Trajectory Models
General Description 7-1
Input Data Requirements 7-4
Model Validation 7-7
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PAGE
7. Baseline Oxidant Predictions and 7-8
Development of Alternative Emission
Control Strategies
Sensitivity Analysis 7-8
Level 2: EKMA 7-9
General Description 7-9
EKMA Using Standard Isopleths 7-11
EKMA Using OZIPP-Generated Isopleths 7-12
Level 3: ROLLBACK 7-13
Application Procedure 7-13
References 7-15
8. DEVELOPMENT AND ASSESSMENT OF OXIDANT CONTROL STRATEGIES 8-1
Determination of Requirements for Oxidant Control 8-3
Inventory of Existing and Currently Scheduled 8-4
Control Programs
Development of Candidate Control Measures, 8-5
Including RACTs
Screening the Options 8-8
Selection and Definition of Alternative Control 8-9
Strategies
Assessment of Alternative Control Strategies 8-10
Technical Effectiveness 8-11
Economic Considerations 8-11
Institutional Impacts 8-13
Overall Assessment 8-13
Staff-Recommended Control Plan 8-14
References 8-17
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PAGE
9. PLAN REVIEW, ADOPTION AND APPROVAL PROCESS 9-1
Providing Adequate Time for Public Review g_]
Availability of Review Documents 9-2
Demonstration of Reasonable Further Progress 9-2
Compliance with EPA RACT Measures 9-5
Demonstration of Legal, Financial and Manpower 9-6
Commitment to Implementation
References 9-7
10. THE CONTINUING PLANNING PROCESS 10-1
Tracking Reasonable Further Progress 10-1
Work Program Submittals 10-4
APPENDIX A - BIBLIOGRAPHY OF URBAN SYSTEM MODELS A-l
APPENDIX B - EPA CONTROL TECHNOLOGY GUIDELINE DOCUMENTS B-l
IV
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List of Tables
Table PAGE
2-1 Summary of Oxides of Nitrogen (NOX) Control Issues 1n 2-4
the Bay Area
3-1 Sample Division of Responsibilities for Non-Attainment 3-7
Planning
4-1 Comparison of the Three Levels of Technical Analysis 4-13
6-1 Comparison of Three Different Levels of Emission 6-3
Inventory
6-2 Comparison of Various Data Collection Techniques for 6-12
Baseyear Emission Inventory
6-3 Alternative Methods for Spatial Distribution of Area 6-14
Source Emissions
6-4 Comparison of Emissions Estimate Methods 6-16
8-1 Forthcoming CTGs for Stationary VOC Sources 8-6
8-2 List of Reasonably Available Transportation Control 8-7
Measures
8-3 Washington Environmental Research Center (WERC) Matrix 8-15
8-4 Format of Decision Mjatrlx Suggested in EPA AQMP Guidelines 8-16
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List of Figures
Figure
PAGE
4-1 A Simplified Flow Diagram for (h Non-attainment 4-4
Planning Analysis: Level 1 Analysis Using Complex
Models
4-2a A Simplified Flow Diagram for Oq Non-attainment 4-8
Planning Analysis: Level 3 Analysis Using EKMA
Standard Curves
4-2b A Simplified Flow Diagram for (h Non-attainment 4-9
Planning Analysis: Level 2 Analysis Using EKMA
along with OZIPP Curves
4-3 A Simplified Flow Diagram for (h Non-attainment 4-11
Planning Analysis: Level 3 Analysis Using
Rollback Model
6-1 Block Diagram for Aggregated Emission Inventory/ 6-6
Projection Procedures
6-2 Block Diagram for Disaggregated Emission Inventory/ 6-7
Projection Procedures
7-1 Example Ozone Isopleths Used in EKMA 7-10
8-1 Overview of Procedures for Developing Oxidant Control 8-2
VI
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GLOSSARY
The definition of acronyms and terms used in this document are
given below.
ABAG:
APCD:
AQMD:
AP-42:
CARB or ARB:
CFR:
COG:
EIS:
EKMA:
ELSTAR:
EPA:
HC:
Level:
LIRAQ:
MTC:
MPO:
NEDS:
NMHC:
NOx:
OPR:
OZIPP:
Association of Bay Area Governments
Air Pollution Control District
Air Quality Management District
EPA document, Compilation of Air Pollutant Emission
Factors, including supplements
California Air Resources Board
Code of Federal Regulations
Council of Governments
Emission Inventory System. (This term refers to the
system used by the U.S. Environmental Protection Agency.)
Empirical Kinetic Modeling Approach
Environmental Lagrangian Simulator of Transport and
Atmospheric Reactions
U.S. Environmental Protection Agency
hydrocarbons
three levels of sophistication are given for the oxidant
modeling approaches; Levels 1, 2, and 3 are characterized
as complex, intermediate, and simple, respectively.
Livermore Regional Air Quality Model
Metropolitan Transportation Commission
Metropolitan Planning Organization
National Emission Data System
Non-methane hydrocarbons
Oxides of Nitrogen
Oxidant Prediction Relationship
EPA's Kinetics Model and Ozone Isopleth Plotting Package
VII
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ppm: parts per million
RACM: Reasonably available control measure
RACT: Reasonably available control technology
RATCM: Reasonably available transportation control measure
SIP: State Implementation Plan
UTM: Universal Transverse Mercator Coordinate System
VMT: Vehicle miles travelled
VX: Volatile organic compounds
viii
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Chapter 1
INTRODUCTION
The Clean Air Act Amendments of 1977 continue the requirement for
State Implementation Plans (SIP) to be prepared to attain and maintain
national ambient air quality standards. For a variety of reasons, the
deadlines for submittal of the SIP's and the dates by which the plans
are to demonstrate meeting the various air quality standards have been
revised. Wherever possible, SIP's are to show meeting all applicable
standards no later than 1982. For carbon monoxide and photochemical
oxidants, under specific conditions, a five-year extension to 1987 is
possible.
An important factor in determining what strategies are needed in an
air quality plan is the level at which air quality standards are set.
Recently, for example, the Environmental Protection Agency changed the
photochemical oxidant 0.08 parts per million (ppm) - 1-hour standard to
an ozone (0 ) 0.12 ppm - 1-hour standard. At the time the Bay Area
non-attainment plan was adopted locally, the oxidant standard was still
0.08 ppm; therefore, the plan was developed to meet this standard.
Although the standard has been changed to 0.12 ppm, the techniques used
to develop the control strategy for the study are still valid.
Currently, the Bay Area is re-examining its adopted plan to see what
changes are appropriate. Other non-attainment areas may prepare plans
for the new standard.
These reports have been prepared to assist those involved in
preparing non-attainment plans for use in SIP submittals. Specifically,
the reports deal with preparing photochemical oxidant or ozone control
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strategy plans. Depending on where a particular region 1s 1n the
development of Its plants), these guidance materials should be useful
for the 1982 SIP submittals.
Volume I provides general guidance to non-attainment oxldant areas.
This guidance 1s sufficiently broad In scope that all areas experiencing
oxldant problems should find the report to be useful. Discussions are
presented on the technical procedures for analyzing the oxldant problem
and alternative control strategies. The Intergovernmental coordination
and public Involvement required in the planning process are similarly
described. A systematic approach to plan development is given. This
approach acknowledges the widespread differences experienced across the
nation in the extent and severity of oxldant air pollution. Three
different levels of analysis are proposed depending on regional
availability of data, staff and budgetary resources, and overall
schedules for plan preparation. These three levels of analysis vary in
the degree of sophistication of the models employed for land use and
transportation simulation, emission Inventories, and oxidant
predictions. The modeling approaches can be broadly characterized as
complex, intermediate and simple. The confidence and accuracy of
technical analysis should be proportional to the degree of
sophistication of the models used and the amount of effort expended in
modeling. As conclusions and recommendations derived from the technical
analysis are often important and costly, emphasis of this guideline is
placed on analyses using complex or intermediate models to obtain more
accurate results. The simple models, e.g., rollback technique, are
discussed only for the purpose of preliminary assessment.
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Volume II documents the results of a planning program to develop an
oxidant plan for the San Francisco Bay Area during the period from 1976
to 1978. This volume is a detailed case study of the planning process,
analysis procedures and development of final plan recommendations.
Volume II is intended primarily for air quality planners and/or
technical personnel. As other non-attainment areas embark on similar
planning programs, the recent experiences of the Bay Area should be
instructive. The Bay Area efforts attempted to maintain an open and
highly visible process for developing the plan. At the same time, the
technical approach and analytical methodologies were as rigorous and
objective as possible given the staff and budgetary resources available
to the program. Throughout the plan development as both process and
products were balanced, lessons were learned for conducting similar work
in the future. The documentation of these lessons learned In the Bay
Area—what to do and what not to do--is a major purpose of this report.
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Chapter 2
SPECIAL PROBLEMS OF
PHOTOCHEMICAL OXIDANT CONTROL
The special problems of oxldant control can be categorized under
the following headings:
0 Dynamics of Oxldant Formation
t Characterization of Sources
• Multiple Scales of Effect
0 Institutional/Regulatory Implications
DYNAMICS OF OXIDANT FORMATION
Oxidants in urban areas result primarily from complex Interactions
among reactive hydrocarbons and nitrogen oxides in the presence of
sunlight. The magnitude and distribution of oxidant in an urban area
are affected by a number of factors, including: 1) the amount and
distribution (spatial and temporal) of emissions of reactive
hydrocarbons and oxides of nitrogen; 2) composition of reactive
hydrocarbons; 3) meteorological and topographical conditions; and 4)
other factors, such as background conditions. A reasonable degree of
technical understanding of the dynamics of oxidant formation is
considered crucial to establishing the technical credibility of the
oxidant non-attainment planning effort. Detailed discussions of the
dynamics of oxldant formation may be found in References 2-1, 2-2, and
2-3. The dynamics of oxidant formation can be simulated by
sophisticated, "state-of-the-art" photochemical dispersion models, which
are very data-intensive and resource-intensive. On the other hand,
simplified oxidant models are available which are relatively easy to
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apply but do not consider the complicated photochemical reactions. The
level of accuracy desired for oxidant modeling must be evaluated against
the resources (money, skill, manpower and equipment) available, overall
schedule for the planning effort, and other factors.
CHARACTERIZATION OF SOURCES
The characterizing of sources leading to oxidant formation in an
urban area has been an area of research for many years. Generally
speaking, oxidant concentrations measured in an urban area may be
attributable to the following sources:
0 emissions of man-made organic and nitrogen compounds from
the study area
0 emissions of natural organic and nitrogen compounds from
the study area
0 oxidant (and/or precursors) transported from areas
outside the study area.
Relative levels of oxidant resulting from each of these three
sources will significantly affect the planning strategy for attainment
and maintenance of oxidant standards. Unfortunately, detailed
information on the relative contributions of various sources to oxidant
formation is not available for most non-attainment areas. Based on the
most recent studies of this issue, the U.S. Environmental Protection
Agency has suggested in a draft policy statement that a natural
background concentration of 0.04 ppm oxidant be assumed for the purpose
of control strategy planning (2-4). Further investigations of the
sources of oxidant precursors and their chemistry, meteorological
effects, and long-range transport of oxidant and precursors are
necessary in order to better understand and control the oxidant
problems.
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MULTIPLE SCALES OF EFFECT
The multiple geographical scales of photochemical oxidant impact
was an issue which surfaced in the oxidant modeling analysis in the San
Francisco Bay Area (2-5). The LIRAQ model was used to test the
sensitivity of maximum oxidant levels to changes in hydrocarbon and
nitrogen oxides emission levels. As an example, Table 2-1 summarizes
what is known and what is suspected in regard to the effects of further
control of NOV emission on oxidant levels in the San Francisco Bay Area.
A
The LIRAQ sensitivity analysis indicates that further NOx control
will result in higher oxidant levels within the region than would occur
with a "hydrocarbon only" control strategy. On the other hand, by not
controlling nitrogen oxides, it is suspected that the oxidant problem of
the Bay Area may be transported to a neighboring airshed (e.g., to
Sacramento, 90 miles to the northeast, or to Monterey, 70 miles to the
south). The implications to be drawn are that hydrocarbons should be
stringently controlled and that care should be exercised in deciding the
appropriate degree of nitrogen oxides emissions control.
EPA is continuing studies of this 03/NOX relationship and the
control strategy implications likely to result from additional
information.
INSTITUTIONAL/REGULATORY IMPLICATIONS
A number of agencies have direct control over air pollution
sources. Many other agencies affect air quality indirectly through
agency policies. A non-attainment area plan must be concerned with both
direct and indirect causes of the oxidant problem. In other words, both
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THE IMPACTS OF ADDITIONAL NOX CONTROLS
THE IMPACTS OF NO ADDITIONAL NOX CONTROLS
OXIDANT AIR QUALITY
Within the Bay Area
LIRAQ analysis indicates
that higher levels of
oxidant occur with NOX
controls in the proposed
comprehensive strategy.
Outside the Bay Area
It is su s p e ct ed that
downwind areas where
transport may contribute
to existing oxidant
problems would be
improved.
OXIDANT AIR QUALITY
Within the Bay Area
LIRAQ analysis indicates
that lower levels of
oxidant occur with m> NOy
controls in the proposed
comprehensive strategy.
Outside the Bay Area
It is suspected that
downwind areas where
transport may contribute
to existing problems
would experience worse
oxidant air quality.
NITROGEN DIOXIDE (N02) AIR QUALITY
Within the Bay Area
May reduce N0£ violations
jrf appropriate controls
can be identified, e.g.,
stationary vs. mobile and
ground level vs. elevated
emissions.
Outside the Bay Area
Not of concern (noNOx
violations are recorded
in neighboring air
basins).
NITROGEN DIOXIDE (N02) AIR QUALITY
Within the Bay Area
NOX emissions are
projected to be
relatively constant
between 1975-2000.
However, the relative
contributions from mobile
sources and industry
change substantially.
N0£ violations may
decrease as the motor
vehicle NCL emissions
decrease by 2QQQ.
Outside the Bay Area
Not of concern (no.NOp
violations are recorded
in neighboring air5
basins).
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control strategies and policies influencing air quality should be dealt
with, and all agencies involved directly and indirectly should be
coordinated and consulted in the planning process. The Clean Air Act is
explicit in the requirements that each plan provide for the exchange of
Information and identification of intergovernmental responsibilities as
necessary to develop and implement the plan. Unless all agencies
Involved are well coordinated, any proposed oxidant control program may
create conflicts between the various agencies over responsibilities,
jurisdiction, control philosophy, etc. Institutional coordination and
cooperation 1s an important part of the air quality planning. Chapter 3
of this guidance addresses the various aspects of this issue.
REFERENCES
2-1 Jerskey, T.N., and J.H. Seinfeld, "Continued Research in Mesoscale
Air Pollution Simulation Modeling: Vol. IV - Examination of the
Feasibility of Modeling Photochemical Aerosol Dynamics,"
EPA-600/4-76-016d, U.S. Environmental Protection Agency, Office of
Research and Development, Research Triangle Park, N.C., May, 1976.
2-2 Roth, P.M., et al , "An Evaluation of Methodologies for Assessing
the Impact of Oxidant Control Strategies," prepared for the
American Petroleum Institute, EF76-112R, Systems Applications, Inc.
San Rafael, California August, 1976.
2-3 MacCracken, M.C., et al , "The Liver-more Regional Air Quality Model:
Volume 1. Concept and Development," Lawrence Livermore Laboratory,
University of California, Livermore, California, Report No. UCRL -
77475, August, 1977.
2-4 "Uses, Limitations and Technical Basis of Procedures for
Quantifying Relationships Between Photchemical Oxidants and
Precursors," EPA 450/2-77-021a, U.S. EPA, Office of Air Quality
Planning and Standards, Research Triangle Park, N.C. November,
1977-
2-5 DeMandel , R.E., L.H. Robinson, J.S.C. Fong, and R.Y. Wada,
"Comparisons of EPA Rollback, Empirical/Kinetic, and
Physicochemical Oxidant Prediction Relationships in the San
Francisco Bay Area," J. Air Poll. Control Assoc., 29(4) , 352
(1979).
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Chapter 3
INTERGOVERNMENT COORDINATION
AND PUBLIC INVOLVEMENT
IN THE PLANNING PROCESS
Central to the success or failure of air quality planning in
non-attainment areas is the intergovernmental coordination and local and
public involvement necessary to begin and carry out the planning
program. This chapter briefly describes key requirements of the 1977
Clean Air Act with respect to intergovernmental coordination and public
involvement. It also covers some important organizational aspects of an
air quality planning program in non-attainment regions. For additional
information, earlier EPA guidance materials on these topics are also
available (3-1, 3-2).
REQUIREMENTS OF THE CLEAN AIR ACT
The Clean Air Act Amendments of 1977~as did the previous version
of the Act—require the development of air quality plans in regions
where the national ambient air quality standards are not being achieved.
The 1977 Amendments, however, go much further than previous legislation
in specifying the content and organizational requirements to preparing
such plans. For example, the 1977 Act also specified that, where
possible, the non-attainment plan is to be prepared by an organization
of elected officials of local governments. Section 174 further
specified that, where feasible, the agency designated to prepare the
revised implementation plan shall be the metropolitan planning
organization (transportation planning) or the organization responsible
for air quality maintenance planning, or the organization with both
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responsibilities. The language noted above contains a great deal of
flexibility for states and local governments to determine how such plans
are to be prepared.
STATE AND LOCAL CONSULTATION PROCESS
Section 121 of the 1977 Amendments ensures an orderly process for
organizing and carrying out the planning process. The section provides
that each State shall provide a "satisfactory" process of consultation
with general purpose local governments and designated air quality
planning organizations of local elected officials. The consultation
process covers the actual process of designation of agencies under S.
174 of the Act and the process of developing plans required by the Act.
A consultation process for plan preparation is defined in EPA
regulations (40 CFR Part 51) as satisfactory if it includes:
t Information dissemination and education of relevant
organizations and individuals
• Opportunity for involvement of affected governmental
organizations and elected officials
• Opportunity for joint resolution by affected governmental
organizations and Individuals on key issues (including
selection of control strategies, especially those
requiring local enforcement, implementation or commitment
of resources).
The regulations on intergovernmental consultation also provide for
coordination of other Federally assisted regional planning programs,
State and areawide clearinghouse review, summaries of plan development,
and public and agency participation.
DETERMINATION OF RESPONSIBILITIES
Although it is readily apparent from the 1977 amendments that the
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states continue to be responsible for adoption of the State
Implementation jjlans, the partnership emphasis of the 1977 Amendments
presents the states and local agencies with a wide array of choices
about assigning planning tasks. Among the regulatory requirements under
S. 121 1s that the governor of each state discuss the "alternatives
investigated for consolidation of environmental and other planning
functions."
In determining responsibilities to be divided, a number of
different approaches can be taken. The central features of any planning
process as rigorous as that required by the Clean Air Act are these:
§ Technical analysis (including baseline emission inventory,
future emission inventory projections, oxidant prediction,
modeling)
0 Control strategy analysis (including assessment of
effectiveness, costs, and environmental, social and
economic effects)
• Public participation
• Plan review and adoption
The more complicated the organizational setting, the less readily
apparent will be the division of responsibility. For example, in a
state where a branch of state government serves as an air pollution
control agency and has authority over a wide variety of air pollution
sources, but where there is no comparable local regulatory agency, the
state may play a more significant role in planning than in a state where
local/regional agencies are more capable of performing of the necessary
tasks.
Another example of the decisions to be made in the process of
"joint determination" is what pollutants to cover. For example, some
states have chosen to interpret various provisions of the Act to mean
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that they (the states) have responsibility over total suspended
participates and sulfur dioxide—with local governments' tasks covering
the transportation-related pollutants (hydrocarbon, nitrogen oxides and
carbon monoxide). Other states have determined it appropriate to have
local agencies deal with all pollutants where a standard is violated.
As long as a plan is prepared to meet the requirements of the law,
however, how such a plan is prepared will depend on the desires of both
state and local officials. Wherever a local agency has demonstrated a
willingness or capability to address all pollutants, it makes sense that
they do so, because a single, coordinated planning and public
participation process can be used to examine alternative controls and
assess their costs and benefits. It also tends to present information
in a standardized fashion to Improve public understanding.
LOCAL LEAD AGENCY DESIGNATION
Although the Act itself does not use the phrase "lead agency" the
concept of a lead agency is used in EPA's S. 121 regulations. The
responsibility for ensuring satisfactory intergovernmental consultation
is assigned by the regulations to any governmental organization that has
the "lead responsibility for development" of ai.y of the following
Implementation plan elements:
• Procedures for pre-construction review of direct sources
• Transportation-related control measures
• Control measures other than transportation-related
measures.
• Measures for prevention of significant deterioration of
air quality and protection of visibility
• Air quality maintenance measures
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t Delayed compliance orders under S. 113 (d).
The regulations, therefore, contemplate substantial involvement in
the planning process by many agencies.
INTERGOVERNMENTAL COORDINATION
In many respects the 1977 amendments and EPA's implementing
regulations recognize the intergovernmental complexities of most of the
nation's metropolitan areas, and the varying degrees of organizational
levels in the different states.
In most states there is no single statewide agency responsible for
both air pollution controls and transportation. Thus, just as there is
a national interagency agreement on air quality/transportation
coordination, there may have to be state-level agreements between a
state transportation agency and the state air pollution control agency.
Similar agreements might be necessary or desirable to coordinate air
quality activities with energy facility siting agencies.
At the metropolitan level, similar coordination activities will be
required. For example, at least 10 of the states have designated air
quality planning organizations that are not metropolitan planning
organizations in their respective urban areas. These states include
California, Illinois, Montana, Nevada, New York, Ohio, Pennsylvania,
South Carolina, Virginia and Washington.
Another example where coordination is needed is for stationary and
mobile sources. In many states--Cal ifornia is one example—mobile
source controls are the sole responsibility of the state. Regional or
local air quality regulatory agencies may exist independent of areawide
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planning organizations.
In most areas, sucessful air quality planning will require
extensive cooperation among local, regional and state agencies. The
coordination and organizational cooperation needed will vary from region
to region, reflecting differing organizational authority and air quality
planning capability. Table 3-1 depicts a sample division of
responsibilities for non-attainment planning purposes. It is intended
only to illustrate the kinds of determinations that should occur during
the initial planning period, before the technical analysis begins.
PUBLIC PARTICIPATION
Most Federal programs, including those of EPA, require public
participation as an integral part of planning. As noted previously in
this chapter, the "intergovernmental consultation" requirements
generally apply to parties interested in or affected by the air quality
planning provisions.
Numerous techniques for public participation programs ar«
available; most are familiar to organizations and agencies experienced
with Federal programs. What techniques are chosen for the air quality
planning programs should be an essential feature of the designated
agency's overall public participation efforts. Goals and objectives of
the public participation program should be defined in measureable terms,
and the overall project budget should adequately support a well-designed
public participation program. A central feature of the public
participation program should be evaluation of its strengths and
weaknesses during the planning project so that, as problems occur, they
can be corrected.
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Table 3-1
Sample Division of Responsibilities
for Non-Attainment Planning
Program Component
Planning Coordination/Program
Management
Provision of Policy Guidance Task
Force
Organization of
Participation Program
Public
Organization of Joint Technical
Staff
Development of regional land use
and population activity forecasts
Analysis and monitoring of effects
of land uses on air quality
Monitoring and data analysis of
ambient air quality and related
meteorology
Maintenance of emissions inventory
for modeling purposes, assessment
of emission trends and projection
of future emissions for
non-vehicular sources
Assessment of air quality trends
and projections of future air
quality
Development, analysis and
monitoring of stationary source
control measures
«*
Preparation, adoption and
enforcement of stationary source
control measures
Air quality impact analysis
proposed projects
for
Responsible Agency
Council of governments (COG)
COG
COG
COG
COG
COG
Local air pollution control
district (APCD)
APCD
Development of regional
transportation policies and plans
APCD
APCD
APCD
APCD
Metropolitan planning organization
for transportation (MPO)
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Program Component Responsible Agency
Development of regional travel MPO
demand forecasts
Development, analysis and MPO
monitoring of transportation
control measures
Projection of emissions from MPO
transportation sources
Adoption of Mobile Source Control State air pollution agency
Measures
Overall review and coordination of COG
air quality planning effort (data
analysis, modeling, control
strategy development and
assessment)
Analysis of plan's environmental, COG
social and economic impacts
Plan adoption and submittal to Air COG
Resources Board
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REFERENCES
3-1 U.S. Environmental Protection Agency, Office of Air and Waste
Management, Office of Air Quality Planning and Standards,
"Guidelines for Air Quality Maintenance Planning and Analysis,
Volume 2: Plan Preparation", Report No. EPA-450/4-74-002, July
1974.
3-2 U.S. Environmental Protection Agency and U.S. Department of
Transportation, "Section 174 Guidelines", December 1977.
3-3 U.S. Environmental Protection Agency, "Requirements for
Preparation, Adoption and Submittal of Implementation Plans", 40
CFR Part 51, Subpart M (Intergovernmental Cooperation), May 1978.
3-9
-------
Chapter 4
GENERAL TECHNICAL APPROACHES
This chapter discusses planning of the technical analysis for
oxldant control programs. As there 1s a great variation among
non-attainment areas with respect to the magnitude of the oxldant
problem and resources available for plan preparation, the technical
approaches presented are deliberately general and flexible. In order to
be useful to a variety of non-attainment areas, three different levels
of technical analysis are discussed. These three levels of analysis
vary In the degree of sophistication between the models used, and
involve different levels of available resources (manpower, money, time,
skill and equipment). The accuracy of the technical analysis generally
increases as the level of effort increases. However, there are other
factors to be considered in selecting the level of analysis for a
non-attainment area. The following section describes these three
general technical approaches which can be used in non-attainment
planning and analysis, The subsequent section summarizes and compares
various technical approaches. The last section of this chapter presents
several general guidelines, which if followed, can help improve the
technical credibility of a non-attainment planning analysis. More
specific guidelines to each technical analysis element, e.g., compiling
emissions inventory, are discussed in other chapters of this guidance.
It should be pointed out that the U.S. EPA is currently developing
a guidance specifying what levels of ozone modeling analysis various
non-attainment areas should undertake for the 1982 SIP's. Five levels
of analysis are under consideration. These include:
4-1
-------
Level 1 - Photochemical Grid Models
Level 2 - Photochemical Trajectory Models
(Including Intensive City-Specific EKMA)
Level 3 - Application of Basic City-Specific EKMA
Level 4 - Application of Standard EKMA, and
Level 5 - Application of Rollback Model.
The U.S. EPA is also considering various criteria which should be
used in selecting an appropriate level of analysis.
VARIOUS LEVELS OF ANALYSIS AND THE CORRESPONDING ANALYSIS ELEMENTS
An overview of the three different technical approaches to oxidant
planning and analysis are given in this section. For each technical
approach, a simplified flow diagram for major analysis tasks is
presented. These flow diagrams illustrate where to start a technical
analysis for oxidants, what tasks are involved and the interrelationship
and time sequence of those tasks. The major analysis elements involved
in each level of analysis are also briefly discussed. The information
provided is intended to give readers a clear understanding of the
analysis process involved. They will be useful to the project manager
in developing project organization and in preparing a detailed
management plan for conducting the technical analysis.
LEVEL 1 ANALYSIS
The Level 1 analysis involves the most detailed techniques
considered to be available. It employs a grid-based photochemical
dispersion model such as LIRAQ (4-1) or SAI (4-2), or a trajectory model
such as ELSTAR (4-3), as the primary tool for oxidant control analysis.
4-2
-------
Because of the extensive input data required by the oxidant prediction
model, high levels of effort (manpower, time, skill, etc.) are needed to
carry out this level of analysis. This analysis may provide the most
accurate answers to a number of non-attainment planning questions.
Figure 4-1 is a simplified flow diagram illustrating the analysis
process and specific tasks involved. As noted, there are five major
tasks involved in one analysis cycle. The initial cycle begins with
land use, economic, demographic and transportation analyses in order to
determine urban activity levels. Then the emission inventories and
projections are made based on regional activity levels and emissions
data. As required by the photochemical dispersion model, spatial and
temporal resolution of emissions and species allocation of organic
(and/or NOx) emissions are conducted. The next task is to predict
oxidant concentrations using a selected photochemical model. The
additional inputs required (e.g., meteorological and topographical data,
and initial and boundary emission concentrations) are prepared. By
comparing predicted oxidant concentrations with the oxidant standard,
the emission reductions necessary to attain the standard are determined.
At the end of the initial analysis cycle, candidate oxidant control
strategies are developed. The effectiveness of emission reductions of
candidate control strategies are assessed. Then, a new set of
regionwide gridded emission data is developed by considering the
emission reductions resulting from the selected control strategies.
With the new set of emission data, a second analysis cycle is initiated
to analyze the effect of the selected control strategies on regional
oxidant concentrations. This cycle is repeated to evaluate various
oxidant control packages until an appropriate control package is
4-3
-------
Figure 4-1 A Simplified Flow Diagram for O3
Non-attainment Planning Analysis:
Level 1 Analysis Using Complex Models*
1.1 Detailed land use,
employment, and
population analysis
(complex urban
system models)
i
-P.
2. Emission inventory/
projection (using
disaggregated
emission models to
generate regionwide
gridded emission data)
1.2 Detailed travel
demand and
network modeling
3. Oxidant modeling
(using a grid or a
trajectory model)
i
> i
fc/
Meteoro
/logical and
topographic/
data"
' compare
withO,
. standard y
Meet standard
4. Determination
of required HC
and/or NOx
emissions
reduction
Baseline
emission
projections
5. Development of
alternative HC
and/or NOx
emissions control
strategies
Recommended
oxidant control
program
•This is the level of analysis used In the non-attainment planning analysis In the San Francisco Bay Area.
-------
selected.
The five major tasks included in one technical analysis cycle are
summarized in terms of their purposes and products in the following
paragraphs. More detailed guidelines for each specific task are
discussed in Chapters 5, 6, 7 and 8 of this guidance.
Task 1.1: Land Use, Economic and Demographic Analysis
The purpose of this task is to estimate present and
future levels of urban activity for traffic analysis and
emission inventory preparation. This task is generally
conducted by regional and local planning agencies. To
project regional land use, employment, population and
housing, a number of models may be used (EAAM, PLUM,
USM, ALDM, LUAM, LUPDM, NBER-USM, ITL4SMP, BEMOD, etc.,
see Appendix A). Since a disaggregated emission
inventory is required by the photochemical model, the
result of this task is a set of disaggregated
employment, population, and land use data suitable for
use in preparing the emission inventory.
Task 1.2; Travel Demand and Network Analysis
The purpose of this task is to generate the travel data
necessary for projecting transportation-related
emissions. Using the outputs of Task 1.1, and present
and future transportation networks and travel
assumptions, this task generates the traffic volumes and
average speed for each segment in the regional network.
Trip generation data are also generated in this task. A
number of common travel demand models (trip generation
model, trip distribution model, modal choice model,
network assignment model, etc.), may be used for the
analysis. (See Appendix A.) In areas where there is a
high level of air travel activity, air travel may be
considered separately from ground travel.
Task 2: Emissions Inventory/Projections
Based on the urban activity data generated in Tasks 1.1
and 1.2, this task projects emissions inventories for
the baseyear and selected future years. The level of
detail of the emissions inventory must be consistent
with the requirement of the photochemical model to be
used. At this level of analysis, a grid model or a less
complex trajectory model may be used. A grid model
requires a spatial and temporal resolution of emissions
inventory, while a trajectory model considers only the
4-5
-------
pollutants emitted into the air parcel along the
trajectory path. Both types of model require that the
emissions be broken down into certain species classes.
Task 3: Prediction of Peak Oxidant Concentrations
This task is to estimate peak oxidant levels in the
non-attainment area in order to calculate the required
emission reductions. This task includes preparation of
inputs, execution of computer modeling, and
interpretation of modeling results. In addition to
emissions data, a grid or trajectory model will require
several types of inputs. This may include:
• Meteorological data - wind speed, wind direction,
mixing height, etc.
t Sun radiation data - Light intensity, etc.
0 Topographical data, and/or
• Initial and boundary ozone concentrations (or
natural and transported ozone concentrations)
Detailed guidance to photochemical modeling is presented
in Chapter 7 of this document. The peak oxidant
concentrations determined from computer modeling are
used as a basis for calculating emissions reductions
required and developing oxidant control strategies in
the following tasks.
Task 4; Determination of Emissions Reductions
By comparing the estimated peak oxidant level to the
oxidant standard, the emission reductions required to
attain air quality standards can be calculated. The
required reductions establish the goal for developing
various oxidant control strategies.
Task 5: Development of Oxidant Control Strategies
Alternative oxidant control strategies are developed and
assessed in this task. The developed control strategies
should demonstrate that the oxidant standard will be
attained as expeditiously as practicable, but no later
than 1987.
LEVEL 2 ANALYSIS
This level of analysis employs a less complex model, i.e., EPA's
4-6
-------
Empirical Kinetic Modeling Approach (EKMA) (4-4), to estimate the
required oxidant controls. There are two types of EKMA which should be
distinguished. The standard EKMA uses a standard set of ozone isopleths
to calculate the required ozone control (4-4). Another EKMA uses the
Kinetics Model and Ozone Isopleth Plotting Package (OZIPP) to calculate
maximum one-hour average ozone concentrations for the non-attainment
area (4-5). The OZIPP is a "trajectory" photochemical model, and
requires a number of city-specific inputs, including initial precursor
concentrations, light intensity, dilution, diurnal and spatial emission
patterns, transported ozone concentrations and reactivity of the
precursor mix. The results of OZIPP simulations are used to produce an
ozone isopleth diagram. This diagram is then used in EKMA procedure to
calculate the necessary ozone controls.
Figure 4-2a shows a simplified flow diagram for the standard EKMA
procedure. This procedure uses a standard set of ozone isopleths to
determine the HC and/or NOX emission reduction required to attain the
ozone standard. The standard ozone isopleths were developed by EPA
based on fixed assumptions of sunlight intensity, atmospheric dilution
rate, reactivity and diurnal emission patterns. For this reason the
standard EKMA has relatively limited flexibility in application and
cannot treat city-specific factors such as emission patterns or
meteorological conditions. Nevertheless, transported ozone
concentration can be crudely treated by this method using a modified
procedure.
Figure 4-2b shows a flow diagram for EKMA using OZIPP- The initial
task is to collect data for baseyear emissions inventory and to estimate
future land use, economic, demographic data and future transportation
4-7
-------
Figure 4-2a A Simplified Flow Diagram for Oa
Non-attainment Planning Analysis:
Level 2 Analysis Using EKMA Standard Curves
Determination of
Design value for the Base Year
and the corresponding
6-9 am HC and NOx
levels
00
Establish annual total
non-methane HC and
NOx emissions for the
base year (aggregated)
Use standard EKMA
curves to determine
required HC and/or
NOx reductions
Adjustment for
Transported Ozone
Concentrations
Land use, employment,
popujation and
housing analysis
Development of
alternative HC/NOx
emission control
strategies
Recommended
oxidant control
program
Future year projected
annual (aggregated)
non-methane HC and
NOx emissions
-------
Figure 4-2b A Simplified Flow Diagram for O3 Non-attainment
Planning Analysis: Level 2 Analysis Using
EKMA along with OZIPP
-pi
VO
Simulation day
selection; Daily
HC and NOx
emissions
i
^**~
\ 4
•^»^ ^~"
»-
Using OZIPP to
Simulate max. 1-hr
Ozone Concentrations
and to produce an
ozone isopleth
diagram.
I t
>"^ ^^
i i
m^. ' ^f
»-
Using the generated
ozone isopleths in
EKMA procedure to
calculate the required
HC and/or NOx controls
t
^^
•+
t
L
Development of
alternative HC/NOx,
emission
control strategies
Recommended
oxidant
control
program
'Mixing
height
light
intensity
Base year emissions
inventory
Land use, employment,
population and
housing analysis
Future year HC
and NOx emissions
-------
activity for emission projections. As required by the OZIPP, the
diurnal and spatial distribution pattern of emissions are estimated.
Other input data required by OZIPP are also prepared; this includes
natural and transported ozone concentrations, light intensity, dilution,
reactivity of the precursor mix, and others. The next task is to use
OZIPP to simulate maximum 1-hour average ozone concentrations in the
non-attainment area. The results of OZIPP simulations are subsequently
used to produce an ozone isopleth diagram. This diagram is then used in
the EKMA procedure to calculate the necessary HC and/or NOX reductions.
LEVEL 3 ANALYSIS
This level of analysis uses a simple technique, i.e., rollback
technique (4-4), to estimate the necessary emissions reductions.
Rollback requires even less data than EKMA used in the Level 2 analysis.
A flow diagram for Level 3 analysis is shown in Figure 4-3. This level
of analysis may also be a possible alternative for estimating bounds on
control requirements for hydrocarbon emissions. The rollback technique
is based on the assumption that a fractional reduction in hydrocarbon
emissions will result in an identical reduction in the maximum oxidant
concentration; it does not consider the effect of nitrogen oxides on
oxidant formation. Thus the application of the rollback technique Is
limited to a first order approximation, and 1s viewed by many to be of
questionable validity.
Using the rollback method, the HC emission reduction necessary to
achieve the oxidant standard can be calculated using the following
equations:
4-10
-------
Figure 4-3 A Simplified Flow Diagram for Oa
Non-attainment Planning Analysis:
Level 3 Analysis Using Rollback Model
Determination of
Design value for
the base year
Establish annual
total non-methane
HC emissions for
the base year
Use rollback model
to determine percent
HC reduction to
meet standard
i
Estimate transported
ozone concentrations
and the related
additivity factor
i
i
i
Development of
alternative HC
emission control
strategies
Future year
projected annual
non-methane
HC emissions
-------
R = (03)adj - X
(03)adj
(03)adj = (03)design - A(To)
where
(03)adj = the adjusted ozone concentration to be used in
estimating control requirements;
(03) design = the 03 design value for the base period;
X = a specified air quality goal, usually the ozone
standard;
A = the additivity factor for transported ozone;
To = the concentration of transported ozone estimated
for the base period;
R = the emission reduction required.
SUMMARY OF VARIOUS APPROACHES
In a non-attainment planning effort, technical analysis of oxidant
concentrations and estimated emissions reduction requirements serve as
the basis for formulating needed oxidant control strategies. The
adopted oxidant control program usually involves costly or controversial
emission control measures. Thus, selection of an appropriate level of
technical analysis is important. Table 4-1 summarizes the advantages
and disadvantages of the above-mentioned three levels of technical
analysis. The major tasks involved in each of the three levels of
analysis are also compared in the table.
4-12
-------
Tiblt 4-1. Comparison of thi Thrte Levels «f Technical Analysis*
Level of
Analysis
Land use. employment.
population and trans-
portation analysis
Emission
projection/Inventory
Oxldant
prediction Mthods
Oeter*1nat1on of
emission reductions;
Development of
control strategy
Advantages of
OPRUsed
Disadvantages of
On Used
e Use computer models
to estimate size and
distribution of urban
activities.
o Use computer models
to generate special
and temporal distribu-
tion of HC and NO
emissions. HC enfl/or
NO, emissions tarn to
be divided Into species
classes.
e Use a grid-based or a
trajectory photo-
chemical dispersion
model to estimate re-
glonwlde grldded oxidant
itratlons.
complex
models to estimate
levels of urban
activities at county
or county-equiva-
lent level.
e Use manual or computer
models to estimate
aggregated HC a NO,,
emissions; relative
distribution patterns
of emission on
simulation day are
required.
o Consider a variety of
HC and NO. emission control
strategies (e.g., spatially
or temporally variable
controls).
e Consider complex
topography, meteorology,
source distribution, and
tnuuimrhnl uione '
concentrations.
e Use EPA's EMU to relate e Consider total HC and/or
oxidant levels to f — - -
cursors concentrat
e Treat limited HC and/or
NO, control measures.
pre- NO emission reductions.
lions. *
e EKHA cannot predict ab-
solute ambient oxidant
concentrations; OZIPP
may be used to estimate
amb1ent_ozone concen-
trations "
o Transported ozone can
be crudely treated
e The models have the highest
potential for validation
Kith observed oildint
concentrations.
e Can provide estimates of
magnitude. Ijcatlon and time
period of the peak oxidant
concentretions•
e Consider composition of HC
and treat NO. emissions;
treat spatial and tem-
poral distributions and
transport of constituents;
consider background con-
centrations
e Capable of evaluating •
wide range of oxidant con-
trol strategies such as
emission reduction at
specific sources, emis-
sion controls at certain'
locations or time periods,
HC emissions control com-
bined with NO, emission
control, etc.
e Less extensive data re-
quirements
e Relatively easy to prepare
the Inputs and apply the
model
e Can evaluate certain types
. of oxidant. control .
strategies
e Consider the effect of both
HC and NO,, and 03 levels;
allow for consideration of
background concentrations
o Data requirements are very ex-
tensive; great amount of man-
power, time and money re-
quired to prepare the Inputs.
• Expensive to execute the model
(cost Is on the order of 1500
per run); computer with large
storage capacity Is required
e Require experienced pertcnmel
to perform the modeling;
difficult to Interpret the
model's outputs
o Model
difficult to validate.
Analysis agrees with smog
chamber experiments; accuracy
In atmosphere may not be good
because of gross simplification
of meteorology.
e Relatively limited application
for oxidant control evaluation
o Is not feasible to apply the
Em In areas where the observed
ratio Is low (<2:1)
e Use simple tech-
niques to estimate
levels of activities
at county or county-
equivalent level.
for the study area are
needed.
e Aggregated HC emissions e Cannot predict oxidant o Consider total HC
concentrations. emission reductions
e Use modified rollback only-
technique to determine
emission reductions required.
e Transported ozone can be
crudely treated.
Technical analysis Includes 1) analysis ef urban activities, 2) emission Inventory and projection, 3) oxidant prediction
and 4) determination of oxtdant control requirements. The results of technical analysis provide a basis for developing
alternative control strategies.
e Easy to apply
e Does not consider NO, emissions;
does not treat spatial or tem-
poral distribution of HC emis-
sions
e Model Is not verified
e Can only be used as a first order
approximation
-------
As noted, the advantages of the Level 1 analysis include a high
level of sophistication, completeness and accuracy. The oxidant
analysis results can be verified with observed concentrations and a wide
range of HC and NOX emission control strategies can be evaluated. This
level of analysis was selected and successfully carried out in several
air quality maintenance areas such as San Francisco and Denver. However,
the emissions and meteorological data required are very extensive and a
substantial amount of manpower, time and money is needed to perform the
analysis.
Level 2 analysis may use either the standard EKMA or OZIPP-EKMA
procedures to determine the required emission reductions. Both EKMA
procedures are the result of several years of studies conducted by the
U.S. EPA. The standard EKMA requires less extensive data and is a less
time-consuming technique, but has relatively limited flexibility in
application. The OZIPP-EKMA procedure is more complicated, and requires
a computer facility to execute the OZIPP and to plot an ozone isopleth
diagram. City-specific factors are considered in the OZIPP-EKMA
procedure. In general, the Level 2 analysis, especially the OZIPP-EKMA
procedure, may be a desirable alternative to the Level 1 analysis, if
the available data and resources are limited. However, the results of
EKMA procedures are generally more difficult to verify as compared to
Level 1 analysis.
Level 3 analysis is a simple technique for calculating the
emissions reductions. However, this technique does not consider the
effect of NOX emissions on oxidant levels. The assumption used in the
model, i.e., the maximum one-hour average oxidant concentration is a
linear function of hydrocarbon emissions, has been criticized in many
4-14
-------
reports (4-6, 4-7, 4-8). This technique may be used for a first order
approximation. Use of this technique for non-attainment planning and
analysis may require EPA's approval in advance.
Strictly from the technical point of view, the Level 1 analysis is
the most desirable approach to a non-attainment planning analysis.
Level 2 can be considered as an acceptable alternative and level 3
analysis may be used only for preliminary assessment.
GENERAL GUIDELINES FOR TECHNICAL ANALYSIS
Several general guidelines for technical analysis are presented in
this section. These guidelines, if followed, could help to facilitate
future oxidant non-attainment analysis. These guidelines stem primarily
from the experiences and lessons gained in preparing the 1979 oxidant
non-attainment plan for the San Francisco Bay Region (4-9).
Recommendations are presented for what to do and what not to do when
selecting and conducting technical analyses. It is hoped that other
•
non-attainment areas may extrapolate from the Bay Area's experience and
gain useful insight into how to improve the technical analysis work in
their non-attainment planning efforts.
As noted previously, the oxidant control analysis involves various
kinds of uncertainties, assumptions, and simplifications. The
techniques used are at best classified as "projection", "estimate", or
"prediction". Such an analysis is frequently frustrated by the lack of
data, guidelines, resources and experienced personnel. Tradeoffs
between degree of accuracy desired and available resources have to be
made at most steps of the analysis. Analyses and predictions, whether
they be land use, emissions, or future oxidant levels, will not be
4-15
-------
completely defensible. Credibility of the technical analysis in an
oxidant non-attainment planning effort is of importance as it usually
leads to a costly and frequently controversial control program. The
following basic considerations are suggested for improving future
non-attainment analysis efforts.
t Emphasize the Initial Planning and Design of Technical
Analysis
A successful non-attainment planning effort requires a
sound initial planning and well-organized management
approach. Before initiating the actual technical
analysis, the non-attainment lead agency must carefully
define what objectives and requirements of the Clean Air
Act the non-attainment plan has to meet. Then an
appropriate level of analysis can be selected. The
selection must be based on a systematic evaluation of a
number of factors including:
• magnitude of oxidant problem
• level of sophistication and degree of accuracy
desired
• time schedule for the non-attainment planning
• availability of data, budget, manpower, equipment
and other resources
• capability of staff
Once the level of analysis (either Level 1 or Level 2) is
selected, a sufficiently detailed project plan should be
prepared. As a minimum, the project plan should cover:
• specific analysis elements and tasks which must
be completed
t time schedule and interrelationship of those
tasks
• approximate manpower resources requirements for
each task
In addition to these technical analysis elements, the
public and local government coordination should be
initiated into the project plan along with a
non-attainment plan review, revision, adoption and
approval process. The initial planning effort should
4-16
-------
cover a sufficient level of detail to ensure the
successful completion of the entire non-attainment
analysis. The Guidance discussed throughout this document
can be used in planning and design of a successful
non-attainment planning program.
• Balance the Process and the Product
Virtually all of the analysis elements, e.g., emission
projection, oxidant prediction, etc. previously discussed
contain some kind of process. Since it is difficult at
best to verify the product (an emission inventory or an
air quality projection for some future years), the most
that can be expected is some general agreement that the
analysis is as good as can be performed at the moment.
The process by which the analysis is conducted is crucial
to obtaining such an agreement. Conversely, as the number
of individuals involved increases, staff resource
requirements, review time, and coordination requirements
multiply. It is therefore necessary to strike a balance
between process and product according to the circumstances
under which a particular analysis is being made.
• Keep All Analysis Elements Consistent
As noted previously, outputs of one element (e.g.,
emission inventory) are usually to be used as inputs to a
subsequent analysis element (e.g., oxidant projection).
The consistency of all analysis elements must be
maintained. A technically sound and defensible air
quality projection is all but impossible without a
technically sound and defensible emission projection.
Similarly, the quality of an emission projection is
largely affected by the quality of land use, economic,
population and transportation projections. The allocation
of resources to the analysis elements should be
commensurate with the estimated significance of the
element. For example, it is not prudent to spend 50
percent of the resources on 10 percent of the problem.
t Maintain Flexibility in the Choice of Methodology
In an oxidant control analysis, techniques (especially
projection techniques) and available data bases are still
at a crude stage of development. Maintaining flexibility
in the methodology used from one analysis to the next is
important. Both methods and data bases, as well as the
resources used to prepare the analysis, will change. The
most appropriate methodology at any given time should be
selected on the basis of conditions and constraints
applicable to that time frame, rather than using one set
of methodologies.
4-17
-------
• Perform Sensitivity Analysis
Projections, whether they be emissions or future oxidant
levels, always have a number of inherent uncertainties,
e.g., emission growth rate, meteorological conditions,
etc. One way to deal with uncertainty is to conduct
sensitivity analyses. Rough sensitivity analyses can be
performed to determine whether the method(s) used is
appropriate to the policy decisions being made. If
significant uncertainty exists, the sensitivity of the
decisions to such uncertainty should be examined. If the
sensitivity is significant, then additional effort should
be devoted to improving the methods and data bases used.
(Several examples of sensitivity analyses are presented in
Volume II of this Guidance.;
• Technical Analysis Should be Objective and Open
Because a non-attainment planning program will be highly
visible (due to public participation required by the Clean
Air Act), objectivity is very important in all aspects of
the work. Several methods can be used to maintain the
professional integrity of the planning effort. An
advisory committee may be established to provide early
review and comment on the analysis. This group may meet
on an as-needed basis for all the technical work,
including technical assumptions, projection methodology,
emission controls, etc. The comments received from this
group should be incorporated into the work of the
technical staffs. When agreement can not be reached on a
particular assumption, it should be clearly stated and
documented along with the rationale for each argument.
Documentation of the key dssumptions is also critical in
projecting future land use, population, emissions and air
quality. At a minimum, sufficient documentation should be
provided for others to be able to reproduce the results.
Where other reports are used, both the actual data and
methodologies used should be cited. For the more complex
analyses, sample calculations or interim data should be
provided. As part of any non-attainment planning effort,
time and money should be allocated in advance for
providing reasonably detailed documentation of references,
assumptions, projection methodologies, sources of data and
the actual results.
• Be Consistent With Other Data
Air pollution emissions and concentrations are directly
related to urban activity in many forms. An air pollution
emission-projection is generally based upon the projected
levels of urban activities. In any given area where
emission projections are being conducted, other
4-18
-------
projections are also being undertaken for population,
employment, land use, transportation, water quality and
supply, energy supply and demand, etc. To the extent
possible, information from this other work should be used
to ensure consistency of data from one program to another.
A questionable assumption can always be debated and
defended if it has been clearly documented. Very seldom,
if ever, can inconsistencies (internal or external) in
projections data be defended.
4-lg
-------
REFERENCES
4-1 MacCracken, M.C., et al, "The Livermore Regional Air Quality Model:
Volume 1. Concept and Development," Lawrence Livermore Laboratory,
California, Livermore, California, Report No. LICRL-77475, August,
1977.
4-2 Reynolds, S.D., "Further Development and Evaluation of a Simulation
Model for Estimating Ground Level Concentrations of Photochemical
Pollutants," Systems Applications, Inc., San Rafael, California
February, 1973.
4-3 Environmental Research and Technology, Inc. ERT Newsletter No.
1-79, Concord, Mass. 01742, May, 1979
4-4 "Uses, Limitations and Technical Basis of Procedures for
Quantifying Relationships Between Photochemical Oxidants and
Precursors," EPA-450/2-77-021a, U.S. EPA Office of Air Quality
Planning and Standards, Research Triangle Park, N.C. 27711
November, 1977.
4-5 "User's Manual for Kinetics Model and Ozone Isopleth Plotting
Package", EPA-600/8-78-014a, U.S. Environmental Protection Agency,
Environmental Sciences Research Laboratory. Research Triangle Park
N.C. 27711, July, 1978.
4-6 Reynolds, S.D. and J.H. Seinfeld, "Interim Evaluation of Strategies
for Meeting Ambient Air Quality Standard for Photochemical
Oxidant," Environ. Sci. Techno!.. 9(5), 433 (1975).
4-7 National Academy of Sciences, "Air Quality and Automobile Emission
Control," Vol. 3. "The Relationship of Emissions to Ambient Air
Quality," a report by the Coordinating Committee on Air Quality
Studies to the Committee on Public Works, U.S. Senate, Washington,
D.C., 1974.
4-8 Schuck, E.A., and R.A. Papetti, "Examination of Photochemical Air
Pollution Problem in the Southern California Area," Appendix D of
"Technical Support Document for the Metropolitan Los Angeles
Control Plan Final Promulgation,"U.S. Environmental Protection
Agency, Region IX, San Francisco, California, 1973.
4-9 Leong, E.Y. and R.Y. Wada, "Emission Inventory Projections:
Hindsight, Insight and Foresight," paper presented at the Air
Pollution Control Association, Specialty Conference on Emission
Factors and Inventories, Anaheim, California, November, 1978.
4-20
-------
Chapter 5
DETERMINING BASE YEAR
OXIDANT CONCENTRATION
For ozone control planning and analysts, one of the initial tasks
is to define the baseline ozone concentrations. The baseline ozone
concentrations are to be used to assess compliance with the ozone
standard; they also provide a basis for determining an appropriate
design value for use in developing control strategies. In most
non-attainment areas, baseyear ozone concentrations are determined based
on ozone sampling data obtained at existing monitoring stations.
In February 1979, U.S. EPA promulgated a new ozone standard (5-1).
The new standard is defined as "the expected number of days per calendar
year with maximum hourly average concentrations above 0.12 ppm must be
less than or equal to 1". This differs from the previous standard for
photochemical oxidants, which simply states a particular standard not to
be exceeded more than once per year. As a result, the approaches to
interpreting compliance with the ozone standard, and the procedures for
determining an appropriate design value have also changed. The
following two subsections briefly discuss the procedures for
interpretation of the new ozone standard and for determination of a
design value.
INTERPRETATION OF AIR QUALITY AND THE OZONE STANDARD
The key issue in interpreting air quality data and the ozone
standard is to determine when the expected number of exceedances is
equal to or less than 1. In the areas where sampling is complete, i.e.,
a valid daily maximum hourly average value is available for each day of
5-1
-------
the year, the procedure for determining the expected number of
exceedances is straight forward. The expected number of exceedances at
a monitoring site is determined by calculating the average of the number
of exceedances recorded for each of the past 3 calendar years.
Compliance with the standard is determined based on whether this average
is less than or equal to 1.
In reality, a valid daily maximum 1-hour average ozone value may
not be available for each day of the year. Incomplete sampling must be
accounted for in determining expected number of exceedances. This can
be done by using the following formula:
v
e = v + - • (N-n-z)
n
Where
e = the estimated number of exceedances for the year
N = the number of required monitoring days in the year
n = the number of valid daily maxima
v = the number of daily values above 0.12 ppm, and
z = the number of days assumed to be less than the
standard level.
More detailed information on the procedures for analyzing sampling
data and computing the expected number of exceedances can be founded in
References 5-1 and 5-2.
DETERMINATION OF DESIGN VALUE
Conceptually, the design value for a non-attainment area is the
value that should be reduced sufficiently to ensure that the area will
5-2
-------
meet the standard. The design value is important in determining
required emission controls and in developing control strategies,
especially when EKMA (Level 2 analysis) or Rollback technique (level 3
analysis) is to be used. Under the previous photochemical oxidants
standard, a design value is the second highest measured value. The
promulgation of the new ozone standard has resulted in a revision to the
definition of the design value. With the wording of the new standard,
an appropriate design value is the concentration with expected number of
exceedances equal to 1. In other words, the design value is chosen so
that the probability of exceeding this concentration is 1 out of 365.
Four alternative methodologies which may be used to estimate a design
value are discussed in detail in Reference 5-2. They are: (1) fitting a
statistical distribution method; (2) table look-up procedure; (3)
graphical estimation; and (4) conditional probability approach. The
first three methods group sampling data from several years into a single
frequency distribution and estimate the design value at the frequency
equal to 1/365. The last method treats sampling data from each year
individually in determining a design value. For the uses, limitations
and examples of these methods, the reader is referred to Reference 5-2.
REFERENCES
5-1 U.S. EPA," National Primary and Secondary Ambient Air Quality
Standards, Revisions to the National Ambient Air Quality Standards
for Photochemical Oxidants." Federal Register, pp 8202 to 8237,
February 8, 1979.
5-2 U.S. EPA," Guideline for Interpretation of Ozone Air Quality
Standards," Office of Air Quality Planning and Standards, Research
Triangle Park, North Carolina 27711, January, 1979.
5-3
-------
Chapter 6
EMISSION INVENTORY AND PROJECTIONS
In an oxidant non-attainment planning analysis, the emissions
inventory and projections are used as the basis for predicting oxidant
concentrations and subsequently for developing control strategies.
Additionally, the emissions inventory and projections can be used to
evaluate "reasonable further progress" toward attainment of the oxidant
standard. A sound non-attainment plan relies heavily upon developing a
detailed and objective emissions inventory.
As required by the Clean Air Act, an emissions inventory must be
accurate, comprehensive, and current. The inventory is an accurate
accounting and characterization of all emissions and their sources in
the non-attainment area. To compile an inventory, the following
information is needed: location of emission, type of process, type and
quantity of emissions, type and efficiency of control system and
stack/effluent parameters. Additionally, significant sources affecting
non-attainment outside the non-attainment area need to be included.
Because the emissions inventory for an oxidant control program should be
as current as possible, a recent baseyear must be selected. Consistency
with air quality data should also be considered in selecting a baseyear
for the emissions inventory. To determine whether the oxidant standard
-j
is to be achieved in future years, emissions projections for those years
need to be developed. These projections are based on assumptions for
future emission source growth and development, technical developments,
and various emission limitations. This chapter presents guiding
principles for preparing the emission inventory and projections.
6-1
-------
PLANNING FOR EMISSIONS INVENTORY/PROJECTIONS
Before compiling an emission inventory, some initial planning with
a sufficient level of detail must be carried out in order to ensure
successful completion of the project. During the planning, the
objectives and specific needs of the emission inventory with respect to
the oxidant control program must be defined first. Consistency among
the oxidant analysis elements, e.g., urban activities projection and
oxidant modeling, needs to be determined. Appropriate methodology is
then developed to meet the objectives. Levels of detail, manpower,
time, equipment and expertise requirements of each methodology must be
evaluated against the availability of source data, resources, and other
constraints. General Guidelines for planning the technical analysis
have been discussed in Chapter 4. The considerations specifically
related to emission inventory and projections are discussed in the
following paragraphs.
As noted previously, one of the primary uses of an emission
inventory is as input to an oxidant model that relates source emissions
to ambient oxidant concentrations. The emission inventory must be
designed so that the results can be interfaced with control strategy
development activities. Before planning an emission inventory, the
oxidant prediction relationship (OPR) to be used should be determined.
Then an emission inventory with a similar level of detail can be
designed. Three levels of OPR are discussed in Chapter 4. The level of
detail for the emission inventory and projections required by these
three levels of analysis are different. Table 6-1 summarizes the three
levels of emission inventories corresponding to each level of analysis.
6-2
-------
Table 6-1. Comparison of Three Different Levels of Emission Inventory
Level
of
Analysis
1
2
3
OPR
Used
photo-
chemical
disper-
sion
model
EKMA
Rollback
Details of Emission Inventory Required
Precursor
Emissions
Considered
reactive
volatile
organic
compounds*
NO , CO.
anfi some-
times SO*
and particu-
lates.
reactive
volatile
organic
compounds
and NO,
reactive
volatile
organic
compounds
Geographical
Area
entire non-
attainment
area (signif-
icant sources
affecting non-
attainment
outside the
non-attain-
ment area also
considered)
entire non-
attainment
area (signif-
icant sources
affecting non-
attainment
outside the
non-attain-
ment area also
considered)
entire non-
attainment
area
Spatial
Resolution
grid cell
level
(1 .2 or
5 Km grid
cell)
county or
county
equivalent
level
county or
county-
equivalent
level
Temporal
Distribution
hourly
annual (or
seasonal —
sunnier
months)
annual (or
seasonal —
summer
months)
Consideration
of Species and
Reactivity
Classification
VOC and NO
species allo-
cation are
required
aggregated
VOC emissions
and NOX
aggregated
VOC emis-
sions
Information
on Indivi-
dual Source
required
desired
but not
required
.
desired
but not
required
Use of Exist-
ing County
Inventory
(NEDS or EIS)
substantial
modifications and
dlsaggregatlon
of existing
county Inven-
tory are
necessary.
may be used
directly or
with minor
modifications
may be used
directly or
with minor
modifications
Requirement
for Computer
to Process
Data
computer with
large storage
capacity Is
required
not required
but desirable
not required
CO
-------
As can be seen, the Level 3 analysis (rollback method) requires an
aggregated, annual HC emissions inventory for the baseyear. The Level 2
analysis (EKMA) requires an emission inventory with a degree of detail
similar to that of Level 3; the only difference is that a NOx emission
inventory is also required by the Level 2 analysis. In the Level 2
analysis, the relative temporal (posts a.m. period) and spatial
distribution patterns of HC and NOX emissions for the selected
simulation day are needed if the city-specific (instead of standard)
EKMA is to be used. In both Levels 2 and 3, the emission inventory can
be compiled at county or county-equivalent levels and then aggregated
for the entire non-attainment area.
The Level 1 analysis (photochemical dispersion model) requires a
much more detailed emission inventory for HC, NO and other pollutants.
rt
A disaggregated emission inventory with spatial and temporal details,
i.e., hourly emissions for each grid cell (1, 2, or 5 km) level, is
required by photochemical dispersion models. Additionally, organic
emissions must be broken down by species classes; ground-level and
elevated emissions can also be treated separately. For this level of
analysis, a significant portion of the effort will be expended on the
preparation of the emission inventories.
Based on the above discussions, an emission inventory can be
broadly grouped into two categories—aggregated and disaggregated. An
aggregated emission inventory can be used in the Level 3 (rollback
model) and Level 2 (EKMA) analyses. The disaggregated (spatially and
temporally distributed) emission inventory is used for Level 1
(photochemical dispersion model) analysis. The basic differences
between the aggregated and disaggregated emission inventory and
6-4
-------
projections are already summarized in Table 6-1. The information
provided can be used for planning and designing the various levels of
emission inventory required for the desired level of analysis in order
to meet the oxidant control objectives.
OVERVIEW OF EMISSION INVENTORY AND PROJECTIONS PROCESS
To gain a perspective of the overall emission inventory and
projections process, Figures 6-1 and 6-2 present block diagrams for the
tasks involved in preparing the aggregated and disaggregated emission
inventory and projections.
The process for compiling an aggregated emission inventory and
projections begins with planning and design of the work tasks. A review
and evaluation of existing emission inventories is the next task to be
conducted. The guiding principle for this task is to utilize the
existing emissions data and inventories to the fullest extent possible.
Various techniques can then be used to collect missing data such as
activity levels, process and operating variables of major sources, etc.
Once the data collection phase is completed, the collected data are
analyzed and compiled, and emissions are calculated. The baseyear
emissions inventory is then established. The next step is to project
the baseyear emission inventory to future years. Both the annual
emissions inventory and projections are made at the county or
county-equivalent levels, and then summed together for the entire
non-attainment area.
Compared to an aggregated emissions inventory, a disaggregated
emissions inventory involves many more tasks and a much greater level of
effort. After completing the initial planning and evaluation of
6-5
-------
Figure 6-1 Block Diagram for Aggregated Emission
Inventory/Projection Procedures
Inventory
planning
and design
Evaluation
of existing
inventories
CTi
Data
collection
point source
Data collection
area source
Data collection
mobile source
Data analysis
and emission
calculations
point source
Data analysis
and emission
calculations
area source
Data analysis
and emission
calculations
mobile source
Base year
emission
inventory
Emission
projection
point source
Emission
projection
area source
Emission
projection
mobile source
Interfacing
with OPR's;
reporting
-------
Figure 6-2 Block Diagram for Disaggregated Emission
Inventory/Projection Procedures
Point source
data collection
Point source
spatial
resolution
Point source
, temporal
' resolution
Highway motor
vehicle temporal
resolution
6-7
-------
existing emission inventories, a grid system upon which the emission
inventory will be based is determined. The next step is to collect data
on urban activity levels, major point source operation, and others.
Then, substantial amounts of effort are required to translate the data
into emissions and to spatially and temporally distribute the emissions.
From this the baseyear emissions inventory is established. A similar
process using areal and source growth projections, legal requirements
and technological advancements is then used to prepare the emissions
projections for the future years. Another major task in the preparation
of disaggregated inventories is the splitting of the HC and NOx
emissions into the various species classes required by the photochemical
model. This effort requires the expertise of an organic chemist and
detailed knowledge of the model's photochemistry and the region's
emission inventories.
Some of the tasks, e.g., "Evaluation of Existing Emission
Inventories" and "Data Collection", are common to both aggregated and
disaggregated inventories. In these cases, the data and information as
well as level of detail required by the same tasks are more substantial
in the disaggregated inventories than for the aggregated inventories.
However, the techniques employed to carry out the tasks may be similar.
For this reason, the guiding principles for those tasks common to both
levels of inventory compilation are discussed jointly in the following
task description sections. Tasks unique to each type of inventory
(either aggregated or disaggregated) are noted. The planning and design
of emission inventory and projections have been addressed in previous
sections.
6-8
-------
EVALUATION OF EXISTING EMISSION INVENTORIES
Following completion of all preliminary tasks, a review and
evaluation of the existing emission Inventories should be made. In most
non-attainment areas, a conventional annual, count/wide emission
Inventory, I.e., EPA's NEDS and/or EIS (6-1, 6-2, 6-3) already exists.
Additional permit and compliance related emissions data are also
maintained by local air pollution control agencies. More importantly,
an inventory for oxidant precursor emissions has been prepared and is
generally available in most designated non-attainment areas. Many of
these data may be used directly in the oxidant control program. In many
cases, the existing Inventories can be updated or upgraded through
limited contact with the sources or through the use of an abbreviated
questionnaire. Attempts should also be made to identify the data
collection, data processing systems, and other framework already
established for the inventory. Thus, 1f the existing inventory does not
meet the current needs, data collection and updating procedures can be
built upon the existing framework. In principle, an emission inventory
should make use of the existing data and system to the fullest extent
possible.
The following considerations are suggested for the evaluation of
any existing emission inventory:
0 Representative of current conditions - is the existing
inventory current or out-of-date?
• An accurate accounting of all appropriate sources - as
most existing inventories were not originally prepared for
oxidant control programs, there may be a number of major
organic and NOX emitters that may either be omitted from
the inventory or treated collectively as area sources
because their emissions of some other pollutants are
small; look for any obvious errors or omissions of large
point sources.
6-9
-------
• Consistency with the needs of the non-attainment plan -
level of detail of the Inventory should be consistent with
the OPR to be used. In general, the existing NEDS or EIS
may be suitable for Level 2 (EKMA) and Level 3 (Rollback)
analyses. Substantial modification and disaggregation of
existing NEDS and/or EIS are required if the Level 1
analysis (Involving a grid-based photochemical model) is
to be used.
• Consistency in institutional boundaries - most existing
emission inventories are at county levels. If a county is
not entirely located within the non-attainment area, extra
effort is needed to apportion that county's total
emissions to the non-attainment area.
DETERMINATION OF THE GRID SYSTEM
This task is needed only when a grid-based photochemical dispersion
model is used as a primary tool in oxidant control analysis (see Figure
6-2). A grid-based photochemical model requires distribution of total
emissions to the grid cell level. Therefore, developing an appropriate
grid system at the start of the emission inventory effort is important.
Generally, rectangular grid cells of equal size are chosen. Selection
of the cell size and the overall grid system is affected by the
resources available for the detailed emission inventory and the computer
model to be used. More detailed guidelines can be found in references
6-4 and 6-5.
DATA COLLECTION
As shown in Figures 6-1 and 6-2, data for emission estimates are
generally collected and compiled in three separate categories: point
source, area source, and mobile source. This is because the methodology
for preparing emission estimates and the required data are different for
each category- For each of the three categories, there are several
6-10
-------
techniques which can be used to obtain the necessary data. In general ,
the necessary data for large and small point sources are the process and
operating variables, and test emissions data if available. For mobile
and area sources, activity levels and emission factors are needed.
Selection of particular techniques or combination of techniques must be
based on the guiding principles discussed previously (objectives, level
of accuracy and detail desired, consistency with the requirements of
OPR, overall time schedule, resources available, etc.). The most
commonly used data collection techniques are summarized in Table 6-2.
The mail survey approach and plant inspection are most useful for
gathering data from point sources. Field surveys and review of
published data sources are useful for collecting area source
information. The urban systems modeling is a primary tool for
estimating the size and distribution of urban activities. It is the
best way to produce the detailed urban activity data necessary for
spatial and temporal distribution of emissions. A number of references
for urban systems modeling is given in Appendix A. Table 6-2 also
briefly describes the advantages and disadvantages of each technique.
The "how to" procedures for these techniques can be found in References
6-6 and 6-7.
DATA ANALYSIS AND EMISSIONS CALCULATIONS
Once the necessary data have been obtained, they must be
interpreted, compiled and entered into the data base. With these data,
various methods can be used to estimate emissions for area and mobile
sources. The "emission factors method" is most commonly used. An
emission factor for a particular source is defined as the amount of
6-11
-------
TABLE 6-2
COMPARISON OF VARIOUS DATA COLLECTION TECHNIQUES
FOR BASEYEAR EMISSION INVENTORY
Technique
Mall Survey Approach
(Questionnaire)
Plant Inspection
Field Surveys
Published Data Source
Urban Systems Modeling
Characteristics
• Most common technique for
collecting point source data.
• Also useful for collecting snail
point sources to be reported
collectively as area source.
• Response of questionnaire varies.
•Errors may result from
Interpretation of questionnaire, or
from Incomplete questionnaire.
• Provide most complete and accurate
Information.
• Resource-Intensive; usually
performed only at Important or
unique large point sources.
• A primary tool for directly
gathering Information on certain
area sources, such as agricultural
burning.
•Errors may result from
extrapolating the survey results to
the entire area.
• Costly method; used only when It Is
absolutely necessary.
• Primary tool for obtaining activity
level Information on most area
sources.
• Supplemental method for gathering
point source data 1f a
questionnaire Is not returned.
• Published data are generally not as
current as required.
• Primary tool for estimating size
and distribution of urban
activities.
• Best way to produce urban activity
data necessary for spatial and
temporal distribution of area
source emissions.
• Re source-1ntens1ve; only
experienced staff can perform the
modeling.
6-12
-------
pollutant released to the air from that source divided by the activity
level of that source; for example, grams of hydrocarbons per vehicle
mile traveled. The emission factor method calculates the total
emissions simply by applying a representative activity level to an
emission factor. EPA has published numerous techniques for estimating
emissions for many pollutant sources, e.g., AP-42 and its Supplements.
For point sources, attempts should be made to collect emissions
data directly from the owners (see previous section on Data Collection).
If they are not collected or not available, the "source test" method or
"material balance method" may be used to determine the emissions. The
source test method monitors the source to determine the actual
emissions. The material balance method calculates emissions by
analyzing the material composition and balance for a process. It should
be noted that the emission factor method is also frequently used for
estimating point source emissions.
Table 6-3 compares the above-mentioned three emission estimation
methods in terms of their application, resource requirements and
limitations. More detailed information on the procedures can be found
in references 6-6 and 6-7.
SPATIAL RESOLUTION OF EMISSIONS
If a grid-based photochemical dispersion model(s) is to be used in
an oxidant control program, emissions data must be resolved to the grid
cell level. The effort needed to spatially resolve emissions data
varies, depending on the type of emissions involved. For point sources,
it is easy to assign the emissions to the appropriate grid cell as one
can pinpoint their locations with a street map and a USGS map of the
6-13
-------
Method
Source Test
TABLE 6-3
COMPARISON OF EMISSION ESTIMATE METHODS
Characteristics
• Most accurate
resource-intensive method.
Material Balance
Emission Factors
but
• Particularly useful for quantifying
major point sources; also useful
for developing emission factors for
area sources.
• Statistical validity of testing
results greatly affected by the
number of tests, time period and
duration of testing, and other
factors.
• Useful method to determine certain
types of large and small sources,
e.g., evaporative, low level,
intermittent or fugitive organic
emissions, for which source testing
method cannot be used.
•Needs detailed process and
operational information; only
experienced engineers can do the
calculations.
• Most commonly used method for area
sources. EPA AP-42 has developed
emission factors for most pollutant
sources.
• Most suitable for estimating mobile
source emissions, petroleum storage
and handling emissions, and other
area sources.
6-14
-------
same scale.
For area sources, spatial distribution of emissions may require
substantial effort. In most cases, area source emissions are reported
at county or county-equivalent levels. Various alternatives may be used
in distributing the countywide emissions to the grid cell level (6-4,
6-5). Table 6-4 compares four commonly-used techniques for spatially
distributing area source emissions. Reference 6-4 has detailed
discussions on spatial resolution of various types of area source
emissions (petroleum storage and marketing, solvent evaporation,
residential fuel combustion, etc). More information on spatial
distribution of emissions may be found in Reference 6-5.
Mobile source emissions represent a challenge for spatial
resolution. In conventional countywide emission inventories, mobile
source emission estimates are usually based on countywide gasoline sales
or total VMT. This kind of inventory does not provide the information
necessary for spatial distribution. Since mobile sources generally
represent a large fraction of total organic emissions, a more detailed
procedure is needed to estimate and distribute mobile source emissions.
Procedures for estimating and distributing mobile source emissions
generally include:
• obtaining detailed traffic data from transportation
planning agencies (link-by-link VMT, trip generation data,
etc.), or by using travel demand forecasting models (see
Appendix A),
• allocating link-by-link VMT and trip generation data to
the grid cell level, and
• estimating emissions at a grid cell level using EPA's
methodology for calculating mobile source emission
factors.
6-15
-------
TABLE 6-4
ALTERNATIVE METHODS FOR SPATIAL
DISTRIBUTION OF AREA SOURCE EMISSIONS
1.
Method
Uniform distribution of
emissions.
2.
Distribution of emissions
as a function of
population.
3.
Distribution of emissions
as a function of
surrogate Indicators.
4.
Emission 1nventory
directly for each grid
cell.
Characteristics
• This 1s the simplest method,
and might be accepted for
fairly uniform residential or
agricultural area.
• Cannot be used In areas with
diverse land uses.
• Useful technique to distribute
residential areas' emissions.
• Most census data concerns
residential population only,
and would thus displace many
non-major point sources which
operate 1n Industrial and
commercial areas.
• Spatial detail may be limited
by census tract size,
especially 1n sparsely
populated areas.
• Most commonly used technique;
a great Improvement over
methods 1 and 2.*
•Require Information on
population, land uses,
employment and others; a
resource-Intensive method.
• Most accurate method.
• Most resource-Intensive;
computer 1s required.
*Used 1n the non-attainment planning
discussed 1n Volume II of this Guidance.
In the Bay Area. Details are
6-16
-------
Allocation of link-by-link VMT and trip generation data to the grid
cell level is usually a simple matter. It can be done by using a
network map and a same scale USGS map and then determining the UTM
coordinates for each segment of traffic network and each traffic zone.
More detailed discussions on spatial resolution of mobile sources can be
found in References 6-4 and 6-5.
Errors in spatial distribution do not change the total mass of
pollutant emissions. In this case, a photochemical dispersion model is
intended for regional photochemical modeling (as opposed to local plume
modeling) so small distribution errors should not be critical to the
oxidant analysis result.
TEMPORAL RESOLUTION OF EMISSIONS
In order to be used in photochemical dispersion modeling, emissions
must be resolved to the hourly level. For major point sources, the
hourly and seasonal process variations are generally known. This
temporal resolution of point source emissions constitutes no problem.
For mobile source and other area sources, the most accurate and most
resource-intensive approach is to determine the emissions of each
individual source for each hour of the time period being modeled. A
less resource-intensive and more commonly used approach is to develop
typical hourly patterns of activity levels for each source category, and
then to apply these hourly factors to annual or daily emissions to
estimate hourly emissions. In developing hourly factors, considerations
should be given to seasonal, weekend/weekday, and peak and average
condition variations. The factors important to temporal resolution of
point, area, and mobile sources are discussed in detail in Reference
6-4.
6-17
-------
EMISSIONS (HC AND NOX) SPECIES ALLOCATION
Since a photochemical dispersion model simulates the process of
photochemistry, precursor emissions must be distributed into the various
species classes required by the model. Generally speaking, hydrocarbon
(HC) emissions are divided into several species classes that behave
similarly in photochemical reactions. One classification scheme groups
HC into four classes: paraffins, olefins, aromatics and aldehydes;
another scheme divides HC by the number of certain types of carbon bonds
present in each HC molecule. Some models also require breakdown of NOX
into NO and N02- Actual species classification required by various
photochemical models can be found in Reference 6-4.
The HC and NOX species allocation scheme used in the photochemical
model must be known before compiling an emission inventory because the
classification scheme influences the information requirements for each
source category and thus the data handling process. If the emissions
data collected are not broken down into species classes, assumptions
about HC and NOX species distribution must be made for each source
category in order to allocate emissions to various species classes.
Techniques for HC and NOX species allocation are discussed in detail in
Reference 6-4.
EMISSIONS PROJECTIONS
Emissions projections include not only forecasting changes in
activity levels, but also involve estimating the effects of emission
control regulations to be implemented. Estimates of changes in activity
levels are usually based on projections of land use, population,
housing, employment and travel demands. These forecasts are generally
6-18
-------
made by regional, local and/or state planning agencies (see Appendix A.)
Additionally, construction of new sources, expansion of existing
facilities, closing of old plants and other similar information on
individual sources must also be included.
Estimating the effect of emission control regulations is also a
complicated task. It requires an evaluation of the effect of the
promulgated "reasonable available control technologies", compliance
schedules, new source emission standards and change in emission factors.
There are two types of emissions projections: baseline emission
projections and control strategy emissions projections. Baseline
emissions projections are prepared by considering the projected changes
in activity levels and the effects of control regulations already
scheduled or in effect. Baseline emissions projections serve as a basis
for determining the emissions reductions necessary to attain the oxidant
standard.
Control strategy emissions projections are emissions estimates
which incorporate the effects of new, changed, and/or additional control
strategies not included in the baseline projection. Control strategy
emissions projections are used as inputs to a photochemical dispersion
model to predict the ambient oxidant concentrations resulting from the
proposed control strategies.
Problems
Emissions projections, by their very nature, are speculative and
represent nothing more than a "best guess" of future conditions. They
frequently involve a number of assumptions, judgments, and other similar
uncertainties. There are generally inherent problems in any emission
6-19
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projections. These may include the following (6-8):
Defensibility - Projections, whether they be population,
unemployment, or emissions, will always be attacked because of
their speculative nature. The technical credibility of
emissions projections will be a function of their
reasonableness (i.e., is it plausible), the amount of research
and documentation of assumptions, and the procedures or
methodologies used to make the projections. In the final
analysis, no projections are completely defensible; however,
there is no reason why they should not be clearly documented,
reasonable and technically credible.
Objectivity - Because of the importance emission inventory
projections play in urban activity planning—e.g., industrial
siting decisions, air quality control strategies, highway and
sewage treatment construction programs—the motives of
projecting emission inventories are always questioned.
Depending on the perspective being pursued the forecast
emissions are "too high,", "too low," "surprisingly
conservative," or "unduly optimistic". It is not uncommon for
a particular set of projections to be a\± of the above at the
same time! Projections will be perceived very differently
depending on the eye of the beholder and what must be strived
for is technical objectivity in the process.
Openness - Because of the previous two problems--defensibility
and objectivity--openness and candor in making emission
projections is needed to gain any credibility. Many a
projection has been made by junior staff in a "closet" which
upon closer examination was not documented, and thus seemingly
arbitrary, or which though documented was clearly
unsupportable. Internal and external review of emission
inventory projections will almost always improve their
technical quality and enhance their credibility.
Uncertainty - Simply stated, projecting emission inventories
is fraught with uncertainty. Some uncertainty can be
accommodated by projecting in ranges or conducting sensitivity
analyses with different assumptions. However, some degree of
uncertainty will always accompany emission projections. This
fact should always be acknowledged immediately. The art of
projecting emission inventories is not eliminating
uncertainty, but learning how to minimize it.
Consistency - Emission inventories are seldom compiled in a
vacuum.Tn any given area where emission inventories are
being projected, other projections are also being undertaken
for population, employment, land use, transportation, water
quality and supply, energy supply and demand, etc. To the
extent possible, information from this other work should be
used to ensure consistency of data from one program to
another. A questionable assumption can always be debated and
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defended if 1t has been clearly documented. Very seldom, if
ever, can inconsistencies (internal or external) of
projections data be defended.
Resources - Very substantial amounts of time and money can be
spent on emission inventory projections. Generally though,
since neither a lot of time or money are available, common
sense should dictate the resources to be allocated to this
task. Seldom are too many resources devoted to this
assignment (if anything the converse is true). As a rule of
thumb, sufficient resources should be committed to conducting
emission inventory projections to circumvent many of the
problems cited above. Also, the allocation of resources
should be commensurate with the estimated significance of a
particular source category. For example, it is not prudent to
spend 50 percent of the resources on 10 percent of the
problem.
Guiding Principles
The general guidelines for technical analysis discussed in Chapter
4, if kept in mind, will help to minimize the above-mentioned problems.
Additionally, the following guidance is also important to improving
emission projections.
t Methodology consistent with that used in baseyear
emissions inventory - it is essential to project emissions
based on methodology and computation principles consistent
with those used in the emission inventory for the
baseyear. This procedure, which should be applied to each
emission category, will insure consistency between
baseyear emissions inventory and the future year emission
projections. For example, if a predictive land use model
(PLUM) is used to estimate land use activity levels in the
baseyear, the same model should be used to project future
land use activity levels. Otherwise, spurious emission
differences may result from changes in methodology and the
associated assumptions.
• Close coordination with planning agencies - as noted
previously, forecasts of future urban activities (land
use, population, employment, transportation, etc.) are
generally conducted by agencies other than air pollution
control agencies. The benefits of close coordination with
planning agencies are two-fold: 1) consistency with other
planning programs - in a non-attainment area where
emission projections are being made, there are probably
several other projections also being undertaken for land
use, population, employment, etc. Emission projections
6-21
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should be based on the information from this other work,
thus, the consistency of data from the oxidant control
programs to others can be established; and 2) optimizing
the usefulness of planning data already developed for the
non-attainment area - this may substantially reduce the
effort required for emission projections.
Overview of Projection Approaches
There is no one correct way of projecting emissions. Many factors
influence the procedures to be used. These factors include availability
of data and resources, personnel, and level of sophistication or degree
of detail required. Since so many air pollution emission source
categories exist, it is prudent to be cognizant of as many projection
techniques available as possible so that different procedures can be
used as appropriate and as differing circumstances dictate.
Perhaps the simplest and most frequently used technique is linear
extrapolation or regression where a series of historical data points are
projected into the future in some simple linear fashion. This procedure
has obvious advantages and disadvantages which will not be articulated
here. A more rigorous extension of the linear regression techniques is
the time series multiple regression procedure. Here the historical
emission estimates are correlated to any number of independent variables
(e.g., population, automobiles, income, fuel use). What results is an
equation which represents the "best" correlation cf the independent
variables with emissions for use in projecting future emissions. The
theory of this technique is that the historical factors which have
apparently accounted for emissions will continue to do so in the future
in the same manner. To accurately forecast emissions using this
technique requires an accurate forecast of all the independent variables
assumed to be important in accounting for historical emission trends.
6-22
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Frequently, very little data are available to assist in making
future projections. In these cases, engineering or scientific judgment
must be used. This can be done in one step in what amounts to be a
"best guess" or in more systematic group techniques such as the Delphi
method. Other gaming procedures are also possible.
Another emission projection methodology is the use of surrogate
variables. This procedure assumes that a given pollution source
category can be accurately projected by projecting some related
variable. For example, increases in aircraft emissions might be based
on projected increases in passenger air travel. Similarly, hydrocarbon
emissions from service stations might be projected on the basis of
forecasts of gasoline sales.
The EPA and other agencies have published several reports and
guidelines addressing emission projections. Detailed "how to"
procedures for the above-mentioned approaches can be found in References
6-7, 6-9, 6-10 and 6-11. The surrogate indicators methodology, used in
the oxidant planning program in the San Francisco Bay Area, is detailed
in Volume II of this Guidance. Selection of particular techniques or a
combination of techniques should be based on the guiding principles
discussed above.
6-23
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6-1
REFERENCES
U.S. EPA, "AEROS Manual Series, Volume I: AEROS Overview," U.S.
EPA, Office of Air Quality Planning and Standards, publication no.
EPA-450/2-76-001, February. 1976.
6-2 , "AEROS Manual Series, Volume II: AEROS User's Manual,"
publication no. EPA-450/2-76-029, December, 1976.
6-3 , "AEROS Manual Series, Volume III: Summary and
Retrieval," publication no. EPA-450/2-76-009a, July, 1977.
6-4 Drivas, P.J., L.G. Wayne, and K.W. Wilson, revised draft final
report, "Procedures for the Preparation of Emission Inventories for
Volatile Organic Compounds, Volume II: Emission Inventory
Requirements for Photochemical Air Quality Simulation Models,"
prepared for U.S. EPA, Office of Air Quality Planning Standards,
Pacific Environmental Services, Inc., Santa Monica, California,
September, 1978.
6-5 U.S. EPA, "Guidelines for Air Quality Maintenance Planning and
Analysis, Volume 8: Computer-Assisted Area Source Emissions
Gridding Procedure." U.S. EPA, Office of Air Quality Planning and
Standards, Research Triangle Park, N.C. 27711, September, 1974.
6-6 U.S. EPA, "Procedures for the Preparation of Emission Inventories
for Volatile Organic Compounds, Volume I," U.S. EPA, Office of Air
Quality Planning and Standards, publication no. 450/2-77-028,
December, 1977.
6-7 U.S. Environmental Protection Agency, "Guidelines for Air Quality
Maintenance Planning and Analysis - Volume 7: Projecting County
Emissions," EPA-450/4-74-008, U.S. EPA, Office of Air Quality
Planning and Standards, January, 1975.
6-8 Leong, E.Y., and R. Wada, "Emission Inventory Projections:
Hindsight, Insight and Foresight," paper presented at the APCA
Specialty Conference on Emission Factors and Inventories, Anaheim,
California, November, 1978.
6-9 TRW, Inc., "Development of a Sample Air Quality Maintenance Plan
for San Diego," prepared for U.S. Environmental Protection Agency,
Report No. EPA-450/3-74-051, 1974.
6-10 Booz-Allen and Hamilton, "Regional Emission Projection System,"
prepared for U.S. Environmental Protection Agency,
EPA-450/3-75-037, 1975.
6-11 Bay Area Air Pollution Control District, "Method of Projection,"
San Francisco, California, May 31, 1977.
6-24
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Chapter 7
OXIDANT PREDICTION METHODS
Three levels of sophistication in oxldant prediction methods are
presented In this guidance. The most sophisticated Is the Level 1
analysis. At this level of analysis, a dynamic grid-based photochemical
model or a trajectory model may be used for predicting oxidant levels
resulting from proposed emission control strategies of oxidant
precursors. The Empirical-Kinetic Modeling Approach, EKMA, is the Level
2 analysis. A standard set of ozone isopleths can be used in the EKMA
procedure to assess emission control strategies. Another option of EKMA
is to use a trajectory photochemical model, i.e., the Ozone Isopleth
Plotting Package (OZIPP), to simulate maximum 1-hour average ozone
concentrations. The results of OZIPP simulations are used to generate
an ozone Isopleth diagram. This diagram is then used in the EKMA
procedure to calculate the required ozone controls. Last is the
rollback technique (I.e., Level 3 analysis). The rollback model is
based on the assumption that for a given region, a reduction in
hydrocarbon emissions will produce a proportional reduction in maximum
oxidant levels. This chapter discusses these three levels of analysis.
LEVEL 1 - PHOTOCHEMICAL DISPERSION MODELS: GRID OR TRAJECTORY MODELS
General Description
Photochemical dispersion models attempt to describe in mathematical
terms the various physical and chemical processes that are responsible
for ozone formation. They can be used to quantify the relationships
between emission sources and ozone concentrations at various receptor
7-1
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locations, and similarly to evaluate the effectiveness of proposed
emission control strategies on oxidant precursors. At this level of
analysis, a grid (Eulerian) or a trajectory (Lagrangian) model may be
used. The following paragraphs briefly discuss these two types of
models. For more detailed information on application of photochemical
dispersion models, the reader is referred to Reference 7-1.
A grid-based photochemical dispersion model simulates ozone
formation and transportation on a grid over the region of interest by
considering diffusion and chemical reactions of oxidant precursors as
they are passed from grid to grid according to the wind field defined
for each grid. The atmospheric diffusion of pollutants is treated in
three or two spatial dimensions. Among various photochemical models,
the grid-based models are the most sophisticated and offer the highest
accuracy of ozone prediction. However, the level of effort required is
the greatest and the data and resources needed are the most extensive.
A trajectory model may be a compromised alternative to a grid-based
model if available data and resources are relatively limited. A
trajectory model considers oxidant precursors as they enter into a air
parcel moving along a trajectory path according to local mean wind speed
and direction. Ozone formation and transportation is simulated by
solving equations of chemical reactions and vertical mixing of
pollutants in the air parcel.
The following is a list of example photochemical dispersion models
available:
Grid or Eulerian models -
t LIRAQ-2, developed by Lawrence Livermore Laboratory. This
was the model used for the San Francisco Bay Area
non-attainment analysir (7-2)*.
7-2
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t SAI 'Urban Airshed Model, developed by Systems
Applications, Inc. The model has been used for several
urban studies (7-3)*.
t IMPACT, developed by Science Applications, Inc. The model
was developed for the CARB (7-4)*.
• MADCAP, developed by Form and Substance, Inc. San Diego
is using this model for its non-attainment planning
analysis (7-5)*.
Trajectory or Lagrangian models -
• ELSTAR, developed by Environmental Research and
Technology, Inc. This model was developed for the
Coordinating Research Council (7-6, 7-7)*; an official
document is to be published in the near future.
• OZIPP, developed by the U.S. EPA. This model is usually
used along with EKMA and will be discussed in the Level 2
analysis of this guidance (7-8)*.
Because of their sophistication, photochemical dispersion models
have the highest potential for answering a number of strategic oxidant
control issues. These issues would be of importance in evaluating the
effectiveness of alternative emission control strategies in reducing
ambient oxidant levels. Among these issues are the following:
• Hydrocarbon versus NCX control - These pollutants are the
primary ingredients in the photochemical reaction for
ozone formation, and changes in the hydrocarbon/NOx ratio
due to various emission control strategies would change
the resultant oxidant concentration. Eulerian or
Lagrangian models can be used to provide estimates of the
degree of both hydrocarbon and NOX control required to
meet the standard.
• Assessing attainment of oxidant versus short-term N02
standard - A short term N02 standard is called for in the
1977 Clean Air Act Amendments. Eulerian and Lagrangian
models can theoretically perform both oxidant and NOg
predictions. The validity of the latter prediction still
needs to be field-verified.
*References cited are the user's manual(s) for the model.
7-3
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• Control of low-level vs. elevated sources - This issue
weighs the cost-benefit ratio of one type of source
control policy vs. another. Vertical resolution is needed
to address this issue. All but the LIRAQ-2 models are
multi-layer models in the vertical and can be used for
such a policy evaluation.
• Selective control of hydrocarbon compounds - It is
possible that in the preparation of alternative emission
control strategies, sources emitting a single hydrocarbon
class might be singled out for control. The effect of
such a policy on ambient ozone levels can be assessed by
the complex models to a degree. The number of hydrocarbon
classes ranges from three to five and these specific
hydrocarbons can be used for control strategy testing.
• Long-range transport - Oxidants and its precursors are
known to be capable of long-range atmospheric transport
from ojie air region to another. In such an instance, the
boundary and initial concentrations of the air region into
which the pollutants are carried would reflect this effect
as would the ambient oxidant levels. The magnitude of
such an effect has not yet been assessed.
• Effect of spatial and temporal variation - Selective
siting and defined operating schedules for projected
sources would affect ambient oxidant levels. As the
photochemical dispersion models are space and time
dependent, they are most suited for such a growth policy
study.
Input Data Requirement
Input data for a photochemical dispersion model can be broken down
into three categories: 1) emissions, 2) meteorology, and 3) initial and
boundary ozone and precursors levels (see Figure 4-1). For a grid
model, these data need to be spatially and temporally distributed over a
grid over the region. In other words, data are needed for each of the
grid cells in the region. Efforts required for preparing such detailed
inputs could be substantial. However, it should be pointed out that it
is not necessary to observe all of the required data directly.
Reasonable compromises can be made; such compromises were made with
LIR'AQ as described in Chapter 5 of the Volume II of this guidance.
7-4
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Additionally, each of the above-mentioned grid models has
preprocessor programs for manipulating raw input data into computer
readable codes. This would minimize computation time and data
preparation effort. Most grid models have preprocessor routines for
each of the three input data categories. These are described below:
"(Emissions: A complete, chemically disaggregated,
spatially and temporally varying emission inventory must
be developed for the study area. The amount of
disaggregation necessary is dependent on the specific
model. At the least, the hydrocarbon sources must be
divided into those classes used in the photochemical
simulation. N0y emissions need to be divided among NO and
N02-
Because the models are space dependent, the emission
sources must be located to the resolution of the grid
except for point sources. These are specifically located
at a grid point. For those models incorporating
multi-vertical layers, a vertical resolution of the point
source is also required. This is accomplished via plume
rise calculations so that the stack and plume design
conditions are required input.
The temporal variation of each emission source must be
stated. Usually, a one hour resolution is adequate.
Area and mobile sources can be defined on the grid by a
complex urban system model and a detailed traffic demand
and network model.
The labor requirement to produce this inventory is
dependent on the existing data. However, most air quality
regions either do not have a complete inventory and/or it
is in the wrong format. Several man-months are normally
required.
t Meteorology: A mass consistent wind field is used by all
the models for pollutant transport. All the models except
LIRAQ-2 use a three dimensional field. LIRAQ is single
layered. Input to generate the wind field are wind
direction and speed at different heights (except for LIRAQ
which requires only surface measurements); wind shear
between layers; inversion height; insolation; topography;
latitude and longitude and date. Except for the last
three inputs, all the date needed to generate the wind
field should ideally be available for each grid. This not
being the case usually, interpolation between sites of
actual measured data must be carried out. Because of the
7-5
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lack of data and interpolation, the resultant field must
be scrutinized by an experienced meteorologist to appraise
its consistency, especially in complex terrain. This
process needs to be repeated for each simulation day as
they are selected. This is nontrivial task in itself,
requiring several person-days per simulation day.
t Initial and boundary ozone and precursor levels: These
specify the concentration of ozone and precursors at the
edge of the study area and at the start of the model
simulation for each grid. Most of the time, little or no
actual data are available and professional judgment is
applied.
Generally, the types of input data required for a trajectory model
are similar to those for a grid model, but the level of detail may be
less. Theoretically, a trajectory model requires input data only for
the corridor encompassing the trajectory path. However, general
application of a trajectory model to a non-attainment area usually
requires that emissions and meteorological data be assembled for a
significant portion of the non-attainment area.
The most advanced trajectory model, i.e., ELSTAR, requires input
data with a level of detail almost identical to that required for a grid
model. The ELSTAR requires the following inputs:
t Area Source Emissions
• Point Source Emissions
t Diffusivity Coefficients and Spatial Mesh
• Initial Concentrations of Species
• Latitude, Longitude, and Date
The area and point source emissions including NOX, CO, and five
separate classes of hydrocarbons must be prepared as a function of time
(e.g., hourly). The emissions data are created by an emissions source
flux generation program. This preprocessor program requires a gridded
emission inventory to compute schedule fluxes for a specified
7-6
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trajectory. The fluxes are computed by summing up all of the emissions
from all sources types in the inventory that exist in a given grid cell
at a given time.
The data measured at meteorological stations (surface wind speed,
surface temperature data and radiosonde data) are required by another
preprocessor program to determine the diffusivity coefficients. The
output from the program also supplies information necessary to the user
to specify mesh geometry. The last two items of the required inputs can
be readily obtained or estimated from existing sources.
Model Validation
Because a photochemical dispersion model attempts to duplicate a
real world situation mathematically, its predictions should be verified
by comparison with observed data. If all the input data were correct
and the input assumptions were within reason, the modeling results
should parallel the measured data. If possible, input information may
be adjusted within their range of uncertainty to see if agreement is
improved.
A model which is sufficiently complex to simulate chemical-physical
processes should not have to be calibrated. There are two options for
dealing with the problem of imperfect model performance. The first
option is to accept the model results as they are, making no attempt to
"correct" or "calibrate" the results according to observed data. This
may be done with confidence if more than one prototype day is used
during the model evaluation and validation process to eliminate any
systematic bias in model results. However, it may not always be
possible to eliminate all systematic bias or to obtain satisfactory
results for several different prototype days, particularly if schedules
7-7
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are constrained by regulatory deadlines. In such cases, some method
should be considered for appropriately compensating the results to
ensure that control requirements are not either understated or
overstated. Issues relating to model validation or calibration need
further investigation.
Baseline Oxidant Predictions and Development of Alternative
Emission Control Strategies'
The baseline oxidant prediction is defined as the oxidant level for
some future year if only current regulations for emission control were
applied. Calculation of this baseline prediction involves developing a
future emission inventory based on regional growth and development
policies; regional transportation plans and policies; and regional
stationary source development. The meteorological scenarios for the
simulation days are used. Boundary and initial conditions used for the
simulation day can be used or others can be input. Once the baseline
oxidant predictions are made, various emission control strategies can be
applied to the future year inventory and the effect on oxidant formation
can be discerned. However, because of the large computational costs of
running these models, the labor requirements to develop the emission
inventory and to interpret the output, the number of control strategies
should not be excessive. A prior screening is advisable.
Sensitivity Analysis
The model predictions should be used with discretion because the
results are only as good as the input. Many assumptions and
simplifications have gone into the model formulation and input due to
inadequate knowledge of certain actual phenomena, limited computer
capability and lack of good data.
7-8
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The initial and boundary levels are an important assumption,
especially in a short (e.g., 12 hours) simulation. The time required to
derive input values from the simulation is equal to or greater than the
time needed to perform the short simulation.
Some sensitivity studies have been performed on these models. A
common one is the effect of varying precursor levels on oxidant
formation, which is another way of looking at emission control
strategies. LIRAQ has been used in San Francisco for such a study. SAI
AIRSHED addressed this in the Denver area. Results for both' studies are
applicable only to these specific sites.
LEVEL 2 - EKMA
General Description
EKMA was developed by the EPA as an oxidant prediction relationship
a step beyond ROLLBACK (7-9, 7-10). It is based on a series of curves
relating observed early morning NOX and non-methane hydrocarbon (NMHC)
levels with the predicted maximum oxidant level downwind of a city
center (see Figure 7-1). With the ozone isopleths, relative changes in
ozone levels can be assessed as a function of changing NOX and NMHC
levels.
»
There are two ways to use EKMA. One is to use the standard set of
ozone isopleths which are non-site specific and which reflect only one
meteorological scenario to assess alternative control strategies.
Another way is to make the set of isopleths city-specific. This is done
by using the Kinetics Model and Ozone Isopleth Plotting Package (OZIPP)
(7-8). By using OZIPP, the city specific factors including morning
concentration of precursors; post 8 a.m. precursor emissions; mixing
7-9
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!
I—'
C
ri
o
1J
Figure 7-1. Examole ozone Isopleths used 1n EKMA
-------
height; latitude, longitude and date; reactivity of precursor mix;
transported ozone from upwind areas; and ozone and precursors from aloft
are reflected in the generated ozone isopleth diagram. In other words,
the city-sped f ic factors can be considered in developing ozone
controls.
EKMA 1s particularly useful for addressing the "hydrocarbon vs NOx
control" strategic oxidant control issue. It can do this because EKMA
is basically a photochemical simulation model. Various combinations of
hydrocarbon and NOX control can be evaluated of their effectiveness in
oxidant control.
The two EKMA procedures using either the standard ozone isopleths
or OZIPP-generated isopleths are illustrated in Figures 4-2a and 4-2b
respectively. EKMA application procedures are briefly discussed below.
For more detailed information, the reader is referred to references 7-8,
7-9, and 7-10.
EKMA Using Standard Isopleths
The data required for this analysis are: ozone design value for
the baseyear and the corresponding 6-9 am measured non-methane
hydrocarbon (NMHO/NO ratio, and the baseyear and future year
A
hydrocarbon and NOX regional emission inventory. Care must be exerted
in determining a design value for the baseyear (details are discussed in
Chapter 5). A selected design value for the baseyear is located on the
set of isopleths (see Figure 7-1). Changes in hydrocarbon and/or NOX
levels needed to meet the oxidant standard can then be determined. A
direct relationship is assumed between the hydrocarbon and NOX
measurements and emissions.
For each control strategy, a "target" emission rate of hydrocarbons
7-11
-------
and/or NO is determined. This is an absolute quantity. Comparing this
n
with the projected future year emissions, the relative reduction
required for each pollutant can be determined and the various control
strategies can be developed.
EKMA Using OZIPP-Generated Isopleths
This approach tunes the model to a particular site. In addition to
the data required by the standard method, the following is also needed:
• hydrocarbons split into propylene, butane, and aldehyde
fractions
• NOX/N02 ratio
• concentration of transported ozone and precursors
t mixing heights at 8 a.m. and 3 p.m.
• longitude, latitude and date
With this information, the computer program OZIPP is used to
calculate maximum 1-hr average ozone concentrations. The results of
OZIPP simulation are then used to generate an ozone isopleth diagram.
The procedure for the use of this city specific isopleth diagram is the
same as for the standard isopleth diagram previously described.
The additional labor costs associated with generating the
city-specific isopleth are minimal. Given the total hydrocarbon and NOX
emissions, only relative ratios are needed to separate these two sets of
compounds into their respective species classes. The meteorological
data is easily taken from published sources. Transported ozone and
precursor concentrations can be obtained from upwind measurements.
Also, there are default values for all these inputs. Computation time
to generate a set of city-specific isopleths is insignificant at 3
minutes on an IBM 370/168 computer.
7-12
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EKMA cannot be used to predict absolute ambient oxidant values;
rather, it is meant to be used for evaluating the effects of relative
changes in precursor levels on oxidant formation on a regional basis.
The EKMA model hasn't been validated or verified, though its chemistry
has been verified in the sense that it is based on smog chamber tests.
LEVEL 3 - ROLLBACK MODEL
In the brief history of oxidant modeling for control strategy
evaluation since the 1970 Clean Air Act, only rollback models have been
sanctioned by the U.S. Environmental Protection Agency. These are the
"Appendix J" rollback model and the rollback model. However, recent EPA
announcements imply that Appendix J is no longer an acceptable method
(7-9). The rollback model is based on the assumption that for any given
region, reduction in hydrocarbon emissions will produce a proportional
reduction in oxidant levels (7-11). Thus by using the rollback equation
and knowing the ozone design value for the baseyear and transported
ozone concentration, one could compute the percentage control for
hydrocarbon emissions necessary to achieve the ozone standard.
Application Procedure
Figure 4-3 is a flow diagram of the application sequence for a
rollback calculation. The first step is to determine an appropriate
design value for the baseyear. A design value is the concentration with
expected number of exceedances equal to 1. The procedures for
estimating a design value from sampling data are discussed in Chapter 5
of this guidance. Once the design value is selected, the total
non-methane hydrocarbon inventory for the region can be assembled on an
annual basis. This inventory is represented by an annual total tonnage
7-13
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of emissions which becomes the foundation for hydrocarbon rollback
calculations.
The rollback model also requires estimates of transported ozone
concentrations for the baseyear. Transported ozone concentrations in
the baseyear can be obtained from upwind measurements or estimated from
published sources. Additionally, the addivity factors for transported
ozone are required. Addivity factors for transported ozone generally
range from 0.2 to 0.7; more detailed information can be found in
Reference 7-9.
With the above-mentioned information, the relative hydrocarbon
reduction, i.e., % reduction, necessary to meet the oxidant standard can
be calculated using the rollback equations (see Chapter 4 of this
guidance). This number applied to the baseyear emission inventory gives
the allowable amount of NMHC that can be emitted and still meet the
ozone standard for the baseyear and for any future year. The NHMC
reduction for the future year is simply the projected emissions minus
the allowable emissions divided by the projected emissions. The
emissions control for the future year is thus identified given the total
NMHC cannot exceed a stated quantity.
The rollback model is the cheapest and easiest to use. It is also
generally acknowledged to be the least precise- No computer is
necessary and only aggregated emissions data for the region are needed.
7-14
-------
REFERENCES
7-1 Association of Bay Area Governments," Application of Photochemical
Models in the Development of State Implementation Plans," 3
volumes, being prepared for the U.S. Environmental Protection
Agency, Office of Air Quality Planning and Standard, Research
Triangle Park, N.C., 27711.
7-2 MacCraken, M.C. and G.D. Santer, eds, "Development of an Air
Pollution Model for the San Francisco Bay Area," prepared for U.S.
Energy Research and Development Administration, Lawrence Livermore
Laboratory, University of California, Livermore California, Report
No. UCRL 51983, December, 1975.
7-3 Reynolds, S.D. and L.E. Reid," An Introduction to the SAI Airshed
Model and Its Usage," System Applications, Inc., San Rafael,
California, December, 1978.
7-4 Fabrick, A., R.C. Sklarew; et. al., "Point Source Model Evaluation
and Development Study," prepared for the California Air Resources
Board and the California Energy Commission, Contract No. A5-058087,
Science Applications Inc., Westlake Village, California, March,
1977.
7-5 Sklarew, R.C., M.A. Joncich, and K.J. Iran, "An Operational Air
Quality Modeling System for Photochemical Smog in the San Diego Air
Basin," paper presented at the Annual American Meteorological
Society, Reno, Nevada, January, 1979.
7-b Environmental Research and Technology, Inc., ERT Newsletter, No.
1-79, Concord, Mass. 01742, May, 1979.
7-7 Personal Communication with Alan C. Lloyd of Environmental Research
and Technology, Inc., Santa Barbara, California.
7-8 "User's Manual for Kinetics Model and Ozone Isopleth Plotting
Package," EPA-600/8-78-014a U.S. Environmental Protection Agency,
Research Triangle Park, N.C. 27711, July, 1978.
7-9 "Uses, Limitations and Technical Basis of Procedures for
Quantifying Relationships between Photochemical Oxidant and
Precursors," EPA-450/2-77-021a, U.S. Environmental Protection
Agency, Office of Air Quality Planning and Standards, Research
Triangle Park, N.C. 27711, November, 1977.
7-10 "Procedures for Quantifying Relationships between Photochemical
Oxidants and Precursors: Supporting Documentation,"
EPA-450/2-77-021b, U.S. Environmental Protection Agency, Office of
Air Quality Planning and Standards, Research Triangle Park, N.C.
27711, February, 1978.
7-15
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7-11 Roth, P.M., S.D. Reynolds, G.E. Anderson, R.J. Polack, M.A. Yucke,
and J.P. Killus, "An Evaluation of Methodologies for Assessing the
Impacts of Oxidant Control Strategies," prepared for the American
Petroleum Institute, Report No. EF76-112R, Systems Applications,
Inc., San Rafael, California, August, 1976.
7-16
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Chapter 8
DEVELOPMENT AND ASSESSMENT
OF OXIDANT CONTROL STRATEGIES
This chapter discusses the procedure for developing and evaluating
alternative oxidant control strategies as part of a non-attainment area
plan. As required by the Clean Air Act, an acceptable oxidant control
plan must demonstrate that the oxidant standard will be attained and
maintained as expeditiously as possible, but no later than 1987. To
achieve this air quality goal, a wide range of control strategies must
be considered. In addition to air quality, the health, welfare,
economic, energy, and social impacts of alternatives considered must be
analyzed. Formulation and assessment of alternative control strategies
is one of the most complex tasks in a non-attainment planning effort.
To gain a perspective of the overall process, an overview of the
procedure for developing oxidant control strategies is shown in Figure
8-1. This overview illustrates the time sequence of several major tasks.
They are:
• Determination of requirements for oxidant control
• Inventory of existing and currently scheduled control
programs
t Development of candidate control measures, including
RACM's
• Screening the options
• Selection and definition of alternative control strategies
• Assessment of alternative control strategies, and
• Recommendation of an oxidant control plan.
8-1
-------
Figure s-1 Overview of Procedures for
Developing Oxidant Control Strategy
1. Requirements
for oxidant
control
2. Inventory
of existing and
currently
scheduled
programs
3. Development
of candidate
control
measures
including
RACM
4. Screen
the options
i
r
5. Selection
and definition
of alternative •
control
strategies
i
k
6. Assessment
of alternative
control
strategies
®
(Recycle as necessary)
o
o
D_,
i
P
7. Staff
recommended
control plan
Non-attainment
plan assembly
h
Local
adoption
State approval
and adoption
Submittal
to EPA
^
Approved
non-attainment
plan and SIP
t
Additional
requirements of
1977 Clean Air
Act
-------
Each of these tasks is discussed in the following sections. The
remaining tasks shown in the Figure (local adoption, state approval and
adoption, etc.) will be discussed in the next chapter.
DETERMINATION OF REQUIREMENTS FOR OXIDANT CONTROL
The initial step in developing an oxidant control strategy is to
determine how much control is needed. The control requirements are
determined by a series of technical analyses including determining the
baseline oxidant concentrations and emission inventories for the
baseyear and future years, and relating these oxidant concentrations to
the precursor emissions. Control requirements have been discussed in
Chapters 4 through 7 of this guidance. Overviews of the technical
analyses which lead to the determination of requirements for oxidant
control have been shown in Figure 4-1, 4-2, and 4-3, for the Level 1, 2,
and 3 analyses, respectively.
Briefly, in the Level 1 analysis, a photochemical dispersion model
is used to relate precursor emissions to ambient oxidant concentrations.
The requirements for emissions (HC and/or NOX) control are determined by
comparing the predicted oxidant concentrations with the oxidant
standard. The disaggregated emission inventory used in the analysis has
detailed information for identifying the major emission sources, with
spatial and temporal details as the primary targets of control.
In the Level 2 analysis, EKMA is used to determine the necessary
emissions (HC and/or NOX) reductions for attainment of the oxidant
standard. In the Level 3 analysis, the percentage reduction of HC
emission necessary to attain the oxidant standard is determined by the
rollback calculations. The rollback model can be used to determine the
8-3
-------
control requirement for HC emissions only; NOX emissions are ignored by
this method.
INVENTORY OF EXISTING AND CURRENTLY SCHEDULED CONTROL PROGRAMS
Prior to actual development of alternative control measures, an
accurate inventory of existing and planned programs which affect the
ability of a non-attainment area to attain the oxidant standard is
necessary. Therefore, an assessment of the effectiveness of ongoing and
currently scheduled controls is made. This will provide a starting
point for developing additional measures for further air quality
improvement.
The inventory should be a complete accounting and characterization
of all existing programs directly or indirectly affecting the oxidant
concentrations in a non-attainment area, e.g., air pollution controls,
land use policies and transportation programs. One direct way to obtain
the necessary information is to survey all cities, counties, districts,
regional agencies, and other political jurisdictions wholly or partly
within the non-attainment area. Additionally, any applicable State and
Federal air pollution control rules and regulations should be included.
In the inventory, a brief definition of the existing programs
should be provided. Additionally, information on the program's current
and future applications, estimated potential effectiveness, responsible
agency, and implementation status and schedules should be included, if
possible. It is also suggested that all the existing and planned
programs be classified into appropriate categories, such as
technological control, land use management, transportation control, etc.
A complete and well-documented inventory of the existing and planned
8-4
-------
programs provides a good starting point for development of additional
measures for consideration.
DEVELOPMENT OF CANDIDATE CONTROL MEASURES INCLUDING RACT'S
After the Initial Inventory of the existing and planned control
programs 1s completed, the next task 1s to Inventory many of the still
remaining control measures which might be considered for further air
quality Improvement. Any measures which have a potential for reducing
or preventing VOC and/or NOX emissions should be Included.
Additionally, the measures which will result in spatial and/or temporal
redistribution of emissions within a non-attainment area should also be
considered. In some cases, the measures which are considered may in
fact already be in existence, e.g., transit service and vehicle exhaust
emission standards. What is considered then is a further strengthening
or expansion of the program 1n place, e.g., more transit service or more
stringent vehicle exhaust emission standards.
All the reasonably available control technologies (RACTs)
identified by EPA must also be Included. The Clean Air Act Amendments
of 1977 require the use of RACTs—at a minimum—in all areas of the
country where the oxldant standard is being exceeded. Up to the
present, EPA has Identified RACTs, also known as Control Technology
Guidelines (CTGs) for 12 categories of sources. Additional source
categories of VOC for which EPA will identify RACTs are listed in Table
8-1.
In addition to RACTs, EPA has published a list of 19 reasonably
available transportation control measures (RATCMs) (see Table 8-2). A
non-attainment plan should consider all of the 19 RATCMs for adoption,
8-5
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TABLE 8-1. FORTHCOMING CTGs FOR STATIONARY VOC SOURCES
GROUP I*
Large Appliance Manufacture
Magnet Wire Insulation
Gasoline Bulk Plants
Metal Furniture Manufacture
Petroleum Liquid Storage,
Fixed Roof Tanks
Degreasing
Bulk Gasoline Terminals
Petroleum Refinery Vacuum Systems,
Waste Water Separators and
Process Unit Turnaround
Service Stations, Stage I
GROUP II
Petroleum Refinery Fugitive
Emissions (leaks)
Surface Coating of Other Metal
Products - Industrial
Pharmaceutical Manufacture
Rubber Products Manufacture
Paint Manufacture
Vegetable Oil Processing
Graphic Arts (Printing)
Flat Wood Products
Service Stations, Stage II
Petroleum Liquid Storage
Floating Roof Tanks
GROUP III
Ship and Barge Transport of
Gasoline and Crude Oil
Organic Chemical Manufacture
Process Streams
Fugitive (Leaks)
Dry Cleaning
Wood Furniture Manufacture
Architectural and Miscellaneous
Coatings
GROUP IV
Organic Chemical Manufacture
Waste Disposal
Storage and Handling
OTHERS
Natural Gas and Crude Oil
Production
Adhesives
Other Industrial Surface
Coatings
Auto Refinishing
Other Solvent Usage
*CTGs have been published for this group.
Source: Reference 8-1.
8-6
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TABLE 8-2. LIST OF REASONABLY AVAILABLE TRANSPORTATION CONTROL MEASURES
MEASURES
Inspection/maintenance
Vapor recovery
Improved public transit
Exclusive bus and carpool lanes
Areawide carpool programs
Private car restrictions
Long-range transit Improvements
On-street parking controls
Park and ride and fringe parking lots
Pedestrian malls
Employer programs to encourage car and van pooling,
mass transit, bicycling and walking
Bicycle lanes and storage facilities
Staggered work hours
Road pricing to discourage single occupancy auto
trips
Controls on extended vehicle idling
Traffic flow improvements
Alternative fuels or engines and other fleet vehicle
controls
Other than light duty vehicle retrofit
Extreme cold start emission reduction programs
Source:Reference «-l.
8-7
-------
or docunentation must be made for not adopting the RATCMs.
In short, the guiding principle for this task is to develop as
complete an inventory of candidate control measures as possible. A
suggested approach is to have each of the agencies participating in the
plan development prepare a list of options for their area of expertise
and/or responsibility. For example, the transportation agency prepares
transportation control options, the air pollution control agency
prepares stationary source control options, etc. Properly executed,
this task will result in a wide range of options for the staff and other
decision-making bodies to choose from in developing alternative control
strategies.
SCREENING THE OPTIONS
The purpose of this task is to screen the inventory of options down
to a more manageable size for further evaluation. This initial
screening should be based on technical effectiveness, applicability, and
other preliminary criteria. For example, RACTs for all 12 CTG source
categories of VOC are supposed to be considered in all non-attainment
plans, however, RACTs for the source categories which do not exist in a
particular non-attainment area should be eliminated from consideration.
Information on the effectiveness of various measures can be found in
EPA's CTG document series (see Appendix B). The screening primarily on
the basis of technical effectiveness will avoid the technical staff
making political judgments regarding an option's political merits and
implementabil ity. Elected officials and the public could judge its
political merits and public acceptability in the later phase of the plan
development. This task will result in a refined list of options which
8-8
-------
are considered as technically effective and applicable for the
non-attainment area.
SELECTION AND DEFINITION OF ALTERNATIVE CONTROL STRATEGIES
Up to this stage of the plan development process, the measures
.represent nothing more than "ideas". For example, "Ramp metering" is
listed only as an "idea" without any detailed information regarding the
implementation. This task will define the measures in a more detailed
fashion. For example, where to apply ramp meters and when to start the
implementation will be defined and the effectiveness of that particular
application will be estimated. The control measures for mobile and
stationary sources have traditionally been direct controls. As such
they should be specified in precise terms. Many of the land use
planning and transportation measures are Indirect controls. Thus, they
may be described in more general terms.
In the process of defining the detailed measures the possibility of
establishing and implementing them is concurrently evaluated.
Availability of resources necessary to implement and enforce the
measure, time requirements, and legal authority are among the factors
that should be considered. Additionally, compatability of the measures
should also be considered. For example, a successful vanpool and
carpool program may not be considered as compatible with a measure
calling for capital improvement of a mass transit system. During the
evaluation process, the number of feasible measures will be reduced, and
it is conceivable that it may clearly Indicate the superiority of
certain measures over others. As a result, this task will develop
several preliminary packages of alternative control strategies for
8-9
-------
further assessment.
Public and local government and intergovernmental coordination is
especially important during this grouping process. Understanding and
agreements should be obtained regarding those measures to be eliminated
from further consideration and those measures to be included for further
assessment. Public participation and intergovernmental cooperation are
discussed in detail in Chapter 3 of this guidance.
ASSESSMENT OF ALTERNATIVE CONTROL STRATEGIES
This task is to conduct a systematic assessment of the various
packages of control strategies selected in the previous task. The
objective is to identify an optimum package of control strategies for
inclusion in the non-attainment plan. The control strategies still
under consideration at this point are effective in emission reduction.
The next step is to quantify their effectiveness. From this a technical
ranking of the control strategies can be made.
In addition to technical effectiveness, the overall economic and
institutional impacts of the control strategies must be analyzed. Each
control strategy will impact the community in various ways. These
impacts may be beneficial to one segment of the cormmity and adverse to
another. As mandated by the Clean Air Act Amendments of 1977, a
non-attainment plan should include identification and analysis of
economic, social, welfare, energy, health, and air quality effects of
the control strategies. The final selection of control strategies
should be based an on overall evaluation of all appropriate factors.
In the following paragraphs, the above-mentioned technical,
economic, institutional and other effects of control strategies are
8-10
-------
discussed and an overall procedure leading to an assessment of these
effects is recommended.
Technical Effectiveness
In the previous tasks, the technical effectiveness of the
individual control strategies has been identified and analyzed. Based
on that information, the purpose of this task is to analyze the
composite effectiveness of various packages of control strategies. The
estimated effectiveness of a control package must then be evaluated
against the requirements for oxidant control previously determined. A
selected package of control strategies should meet the necessary
requirements and provide for attainment of the standard as expeditiously
as practicable. In the Level 2 (EKMA) and Level 3 (Rollback) analyses,
attainment of the oxidant standard is determined by calculating whether
the required emission reduction is met. In the Level 1 analysis, the
effectiveness of a control package is translated into the appropriate
variable or into an adjustment of the emission inventory. Then, the
adjusted emission inventory is input to a photochemical dispersion model
to project ambient oxidant concentrations to determine whether the
oxidant standard will be attained.
Economic Considerations
Economic considerations of control strategies should include
cost-benefit and cost-effectiveness analyses. There are direct and
indirect costs of oxidant control strategies. The direct costs include
all expenditures required of a source, including capital construction
costs, operational and maintenance costs, and administrative/regulatory
costs. The indirect costs include the incremental costs to sectors of
economy other than an emission source, such as price changes for
8-11
-------
materials, changes in property value, etc.
The benefits of control strategies include better protection of
health, vegetation and materials due to cleaner air. Some control
strategies may generate revenues, e.g., increasing tolls as a means to
discourage auto driving. Cost-effectiveness can be measured in terms of
the cost ($) per unit mass (ton) of emission reduced or prevented.
Since various control strategies will have the same benefits—the
control of oxidant pollution—the cost-effectiveness (dollars per ton of
emission reduced) may serve as a common indicator for ranking various
control measures.
Not all of the above mentioned costs and benefits can be measured
quantitatively. The costs of many technological control measures, e.g.,
a device applied to an emission source, a fuel switch, etc. may be
quantified quite precisely. However, for those control strategies
described only in general terms, e.g., land use planning and emission
density zoning, the cost estimate can only be qualitative. In this
case, the assessment may have to rely on subjective judgment. Cost data
sources for a number of selected control strategies can be found in
References 8-2 and 8-3.
Since most control strategies will be implemented over a period of
time, the associated costs should be computed in terms of present value.
The resultant present values should be converted into equivalent annual
costs so that all costs can be compared on a common basis. The
procedure for cost analysis can be found in many engineering economics
textbooks. The factors (interest rate, rate of return, etc.) used in
computing the costs should be consistent for all control strategies.
The total costs of a control strategy should be distributed to the
8-12
-------
appropriate recipients (consumer, owner, government, etc.).
Institutional Impacts
Institutional impacts of control strategies should be assessed in
terms of implementability, public acceptance (social impact), welfare,
legal authority, social effects and others. These institutional impacts
are difficult to measure in quantitative terms.
Public hearings and review meetings are probably the best way to
measure some of the institutional impacts. Public acceptability,
political merits and implementability of each control strategy are best
judged by elected officials and the public whom are likely to be
affected by the proposed strategies. Adequate time should be provided
for elected officials and the public to review the plan or alternative
controls. In the evaluation of public opinions on control strategies,
care should be taken to ensure that undue weight is not given to
opinions of special interest groups.
Other institutional factors such as the welfare costs and social
effects of control strategies are even more difficult to assess than
political merits and public acceptability. The EPA AQMP Guideline
Series (8-2) suggests using social indicators as criteria to assess the
social effects of control strategies. Ranking the strategies in terms
of their social effects can be done by comparing the impact of each
strategy upon each of the social indicators. The procedures for ranking
strategies in terms of their social effects are discussed in detail in
Reference 8-4.
Overall Assessment
To facilitate an overall assessment of various control strategies,
a decision matrix which includes all the above-mentioned technical,
8-13
-------
economic, and institutional factors is suggested. Table 8-3 is an
example evaluation matrix developed by the Washington Environmental
Research Center. Table 8-4 is the evaluation format suggested in the
EPA AQMP document series (8-2). As a rule, the first column of the
evaluation matrix should include all the control strategies to be
assessed; the evaluation factors (cost, benefit, social effects, etc.)
are listed in columns 2 and so on.
For each control strategy, a relative score with respect to each of
the evaluation factors is given in an appropriate column. For the
factors which can be quantified, (costs, emission reduction, cost
effectiveness, etc.), ranking the strategies is relatively easy. For
the factors which cannot be quantified, (social effects, welfare costs,
etc.), ranking must rely upon subjective judgment. An appropriate
methodology should be used to weigh each of the evaluation factors;
thus, an overall ranking of the strategies based upon weighed evaluation
factors can be determined. The completed assessment matrix can then be
carried forward for further evaluation. The public and various
governing bodies of the political jurisdictions within the
non-attainment area will probably make the final judgment of the control
strategies.
STAFF-RECOMMENDED CONTROL PLAN
After completion of the overall assessment process, an optimum
package of control strategies is identified and recommended for
inclusion in the non-attainment plan. In addition to other
requirements, the recommended control plan must demonstrate numerically
that the oxidant standard would be achieved as expeditiously as
8-14
-------
TABLE 8-3.' Washington Environmental Research Center (KERC) Matrix
Implemen-
tation
Tool
in
in
«
*
*j
u
o
«+H
U4
(U
•N»
g
*J
u
1
•»
ECOI
1 - J
5:
Direct
Costs
t.
0)
1-1
1— 1
o
9U
£
*+
y
•f.
§
^
1
&
0
OMIC CONSIDERATIONS
•tost Expensive
foderately Expensive
.east Expensive
Admin.
Costs
4-»
io
i
o
o.
4-1
u
J-
5
tS
00
Monitori
1
0
Social
Costs
i
u
c
a
1
I
0
i— i
f-
C3
1
8
•rt
U
C.
Regional
1
Social
Responsiveness
•
3
0.
u
4-1
i
*
f%
Ij
O.
O
U
s
4-1
2
o
Administrative
Considerations
Control
Application
4-1
«-> in
in rt
X i
l-t •
•i.CM
*,=?
o
•a en
o» i
VI
1-4 4J
« -y.
00—
P
i o
w 3
l!-S
.Slg
4-»j U
«S'2
Selective
Uniform
00
I
_J
en
Strategy 1
Strategy 2
Strategy 3
Source: Reference 8-1.
-------
TABLE 8-4. FORMAT OF DECISION MATRIX SUGGESTED IN EPA AQMP GUIDELINES
Arti of KJNA nhere
Pollutant
Deduction or redistribution required.
Measure
Land Use and Planning
1. [Mission allocation
2. Regional devtlO»»*nl
planning
J. Eaittston density lontm
4. Ion ing approval
5. Transportation control
6. E«
-------
practicable, but no later than 1987. A summary of the recommended
control plan should be prepared, and supporting technical data and the
analysis and decision processes should be documented and retained for
future reference.
In the recommended plan, a concise description of the actions
should be provided. In addition, the plan should include the agencies
responsible for implementation, the implementation schedule, the costs
of the plan, sources of finances, the direct benefits of the plan (in
terms of emission reductions), and other relevant environmental,
institutional, financial, economic, and social information.
The recommended control plan and the other additional requirements
of the Clean Air Act will then be assembled as a complete non-attainment
plan. This plan will subsequently go through local adoption, state
approval and adoption, and EPA approval processes.
REFERENCES
8-1 U.S. Environmental Protection Agency, "Workshop on Requirements for
Non-Attainment Area Plans - Compilation of Presentations," workshop
held in San Francisco, California, March, 1978.
8-2 U.S. EPA "Guidelines for Air Quality Maintenance Planning and
Analysis, Volume 2: Plan Preparation," publication no.
450-4/74-002.
8-3 U.S. EPA, "Guidelines for Air Quality Maintenance Planning and
Analysis, Volume 3: Control Strategies," publication no.
450-4/74-003.
8-4 Klee, A.J., "The Role of Decision Models in the Evaluation of
Competing Environmental Health Alternatives." Management Science,
Journal of the Institute of Management Sciences, 18, No. Z,
October, 1971.
8-17
-------
Chapter 9
PLAN REVIEW, ADOPTION
AND APPROVAL PROCESS
The Clean Air Act requires that the State Implementation Plan be
adopted by a state after a public hearing. The Act does not specify a
local process for adoption of non-attainment plans. As with other parts
of the air quality planning program, the nature and schedule of the
local approval process may vary from region to region, depending on the
geographic size of the non-attainment planning area, the number of local
jurisdictions in the area, and the number and authority of other
agencies involved in the planning program.
PROVIDING ADEQUATE TIME FCR PUBLIC REVIEW
EPA regulations (4C CFR Part 61) require that any draft of a major
implementation plan revision (including any of six elements listed in
51.244 of the regulations) shall be submitted to the state and areawide
clearinghouses for review and comment. The review-and-comment period is
established at 45 days, and comments received during that time are to be
considered before an SIP revision is adopted.
As a practical matter, experience in preparing the 1979 plan
submissions suggests that a 45-day review-end-comment period is not
adequate. To ensure effective and informed decision-making, review
periods of 60-120 days or longer are likely. If control programs
recommended are likely to be highly controversial, requests will
probably be made for more public review time. Schedules for 1982 plan
revisions should provide for some margin toward the end of the plan
9-1
-------
revision process for schedule changes to accommodate, where appropriate,
public requests for extensions in the review period.
AVAILABILITY OF REVIEW DOCUMENTS
Plan revision documents should be made available well in advance of
public hearings. Where possible, non-technical summaries should be
prepared. All material should be readily available to interested
parties, and local libraries and other public locations can be used
effectively in ensuring access to information about what is recommended
and why.
DEMONSTRATION OF REASONABLE FURTHER PROGRESS
The 1977 Clean Air Act Amendments provide an important concept
missing from the 1970 Act—the requirement for "reasonable further
progress." Section 171 defines the term "reasonable further progress"
as annual incremental reductions in emissions of the applicable air
pollutant--(including substantial reductions in the early years
following approval or promulgation of plan provisions under Part D and
Section 110(a)(2)(I) and regular reductions thereafter) —sufficient, in
the judgment of the EPA Administrator, to provide for attainment of the
applicable national ambient air quality standard by the date required in
Section 172(a).
Section 172(b)(3) provides that the "non-attainment" SIP submittal
shall require, in the interim, reasonable further progress (RFP) (as
defined above), including such reduction in emissions from existing
sources in the area as may be obtained through the adoption, at a
9-2
-------
minimum of, reasonably available control technology.
Non-attainment plans should include an RFP schedule. The purpose
of an RFP schedule is to verify that the emission reductions obtained
are being accomplished at a reasonable and efficient rate so that
attainment by the prescribed time will take place. Where only
violations of the annual primary NAAQS are involved, RFP is intended to
represent the application of effective controls as expeditiously as
practicable. RFP schedules to correct violations of the secondary
standards are again intended to depict a timetable for compliance within
"a reasonable time." Where attainment of the oxidant standard can not
be accomplished by 1982, then an RFP schedule reflecting application of
reasonably available control measures will be acceptable as long as
attainment is accomplished by the agreed upon date (not to exceed 1987).
For the majority of cases, EPA expects that RFP schedules will be
linear. A linear RFP schedule is thought by EPA to be completely within
the intent of the Section 171 definition. That is, such a line would
effect substantial reductions in the early going and not put off
accomplishing most of the required reductions until the last year(s). A
linear schedule is also thought to be a stringent timetable to
accomplish emission reductions in light of the lag time for installing
control technology.
In terms of answering the 1979 plan requirement to show RFP, the
submission of a linear RFP schedule will be acceptable even if initially
a linear timetable would be thought inappropriate. Unless the state or
region on its own chooses to submit a detailed nonlinear RFP, a linear
schedule for 1982 attainment SIPs will be acceptable to EPA. Such a
9-3
-------
schedule Is thought to reflect a reasonable rate of progress considering
the relatively short time frame allotted for attainment (maximum of 4 to
5 years). To routinely require a detailed RFP may direct critical
resources from accomplishing the actual attainment. Only in certain
cases where the controls necessary for attainment cannot be reasonably
applied as quickly as required by a linear RFP would it be in the best
interest of a state or region to develop and submit a "less-than-linear"
RFP schedule.
The linear assumption is initially acceptable for all 1979 plan
submittals. Of course, some of the plans, particularly those attaining
standards after 1982, may have to amend their schedules over the year
following the 1979 submittal to make RFP more meaningful. Where the
linear assumption is thought to be inappropriate, an acceptable
alternative RFP schedule must be submitted to the Regional
Administrator. Such nonlinear schedules should be developed over the
year following the 1979 plan submission. EPA acknowledges that
developing such RFPs is more resource intensive and should be attempted
only when absolutely necessary.
A non-linear RFP will typically be developed in the case of oxidant
plans that fail to attain by 1982 but do so not later than 1987.
Herein, the aggregate nature of the emission inventory must be
considered. Individual RFP schedules for each gener-1 component of the
1977 emissions inventory (i.e., mobile, major stationary, and minor/area
sources) must be developed. For post 1982 oxidant SIPs, reductions from
mobile sources until 1983 are expected to follow as a minimum a schedule
consistent with the Federal Motor Vehicle Control Program (FMVCP) and
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the application of RACMs. Beyond 1982 until attainment, the reductions
from mobile sources will reflect the imposition of other measures (as
necessary) as well as the continuing cleanup accomplished by the FMVCP.
Major stationary sources correspondingly must be controlled until 1982
at least as effectively as they would under an RFP schedule exhibiting
the application of RACT. After 1982 and until attainment (no later than
1987) the schedule for reductions will reflect the application of other
control measures. A linear assumption can be made for the portion of
the RFP schedule beyond 1982. Finally, a linear assumption Is
appropriate throughout the RFP schedule for controlling minor and area
(other than mobile) source growth.
COMPLIANCE WITH EPA RACT MEASURES
The Clean Air Act Amendments of 1977 require the use of reasonably
available control technology—at a minimum—1n all areas of the country
where a standard is being exceeded. EPA has identified reasonably
available control technologies (RACTs), also known as control technology
guidelines (CTGs), for 12 categories of sources. Controls for
additional source categories are forthcoming.
Local districts and air quality planning organizations should
review their regulations and, by comparing the regulations with the CTG
requirements, determine if all RACT measures are being implemented.
Where they are not, local agencies should proceed promptly with
development of regulations to comply with the 1977 Clean A1 r Act
requirements for implementation of all reasonably available control
technologies.
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DEMONSTRATION OF LEGAL, FINANCIAL AND MANPOWER COMMITMENT TO
IMPLEMENTATION
This requirement is established in S. 172 of the act. The
requirement itself is a principal reason why implementing agencies
should be directly involved in the planning process and adoption of the
non-attainment plan. The Act requires that the SIP be legally
enforceable. For example, stationary source controls are primarily
implemented by local or regional districts by regulation. A
demonstration of commitment to implement stationary source control
measures occurs only when the local district agrees to carry out the
measures and it has the authority to do so. Similar demonstrations for
other control strategies can only occur as part of the plan development
and approval process. For actions assigned to the state, demonstrated
commitment to implement control measures—as opposed to expressions of
willingness to carry out control measures made by state agencies prior
to local adoption--can only be reasonably expected to occur after the
plan is approved locally and submitted to the state.
For actions for which there does not yet exist legal authority,
demonstrated commitment can be reasonably expected to consist of: a) a
willingness to carry out a reasonably available control measure, and b)
a willingness to seek legal authority. Actions assigned by locally
adopted plans to the State but for which no legal authority to implement
the measures exist require that the State seek legal authority, or
provide adequate documentation of the infeasibility of the proposed
action. Preferably this documentation should occur during the
review-and-comment period prior to local adoption, so the plan may be
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revised. Otherwise the locally adopted plan must be revised at the
state level or by a local-state negotiation process.
Financial and manpower commitments are dealt with using a similar
line of reasoning. Unless an agency demonstrates lack of financial and
manpower commitments, it can reasonably be expected that such
commitments are available if an agency agrees to carry out a control
measure.
REFERENCES
9-1 Environmental Protection Agency, Workshop on Requirements for
Nonattainment Area Plans, revised edition, April
Requii
, 1978.
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Chapter 10
THE CONTINUING PLANNING PROCESS
The continuing air quality planning process should logically follow
from the process and work accomplished during the initial planning
period. Two key tasks to be carried out during the continuing planning
process are to: 1) respond to issues raised during state and federal
review of the 1979 plan submittal when such issues cannot be
satisfactorily resolved prior to plan approval at the state or federal
level, and 2) monitor implementation of initial plan control measures to
ensure that reasonable further progress (described in Chapter 9) is
achieved. The first key task is self-explanatory; the second deserves
further explanation.
TRACKING REASONABLE FURTHER PROGRESS
RFP is to be tracked primarily by a yearly assessment of the net
reductions to actual emissions (including growth) that have taken place.
A summary of these reductions will be submitted as an annual report.
The S. 171 definition of RFP is non-specific as to what type of
emissions inventory should be tracked and reported on an annual basis.
For several reasons, however, EPA believes that the intent of Congress
was to monitor yearly trends in actual emissions to assess if RFP is
being accomplished. Section 172(b)(4) requires emission inventory
development on an actual emissions basis and sufficient revisions
thereafter to enable a determination regarding RFP to be made. The
tracking of actual emissions also seems to be reasonable in that air
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quality trends are best linked to changes in this emissions inventory.
Finally, actual emissions are also important since they are most likely
the basis for determining what controls are needed for cleanup.
The annual report should summarize how total actual emissions have
been reduced relative to the applicable RFP milestones. Only where
special non-linear RFPs are applicable will the annual report be more
specific than reporting total actual emissions (i .e., mobile, major
stationary, and minor/area). Although not formally required, a state or
local agency might also report or at least keep track of how maximum and
allowable emissions have changed over the same time period.
Section 171 defines RFP in terms of annual emission reductions and
does not mention changes in air quality directly. EPA's position is
that air quality changes should be taken into account, at least
qualitatively, in determining if RFP is being accomplished. That is,
the intent of reviewing air quality changes with the associated emission
reductions is to ensure that the reductions accomplished are meaningful
in terms of actual air quality improvement.
The annual report for RFP or the air quality trends data are
expected to identify from time to time the existence of some control
strategy or implementation problems. In fact, this is precisely the
intended function of RFP. That is, the RFP report attempts to identify
problems so that they can be resolved without jeopardizing attainment by
the prescribed date.
Three types of problems can occur. The first is simply failing to
obtain sufficient actual emission reductions to meet the specific RFP
milestone. Such a problem could be the result of excessive growth
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(major and/or minor area growth), enforcement problems, or the lag time
to install control equipment.
The second problem identified is poor air quality improvement
despite the accomplishing of all the emission reductions called for
under RFP. Conceivably, this problem could be caused by the persistence
of unusual meteorological conditions, overestimating the value for
cleaning up certain emissions sources (bad emission factors), or the
omission of key sources from the inventory altogether. The latter more
specifically refers to the lack of control on key sources which have not
been included in the initial emissions inventory developed for the
non-attainment area.
The third and final potential problem is the inability of maximum
emissions to decline at an acceptable rate even though actual emissions
have been reduced in accordance with the RFP schedule. This problem
will likely be noticed by only those states or local areas tracking
trends in maximum emissions. The problem may occur due to delays in
converting SIP allowable emission limits that far exceed what a source
could physically emit to more realistic emission rates or the failure to
constrain the operating hours and/or capacity use of key sources as
appropriate.
In general, no sanctions will be imposed when problems such as
those mentioned are identified if a justification is presented that
demonstrates that attainment by the prescribed date is not jeopardized.
However, in many cases some additional corrective action(s) may be
necessary.
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WORK PROGRAM SUBMITTALS
The 1979 plan submlttals, plus issues raised in the state/federal
approval process, should provide adequate task and schedule detail for
submittal of work programs for the first round of S. 175 grants. Each
year's previous work, plus information gained from tracking RFP and
changes in EPA requirements, should be used in the succeeding work
programs. The key to the work, however, will be the 1982 plan submittal
and the necessity to keep the program on track to meet the plan
submittal deadline.
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Appendix A
Bibliography of Urban System Models
Urban system modeling 1s a primary tool for predicting the size and
distribution of land use activities 1n an urban area; the modeling
results provide .necessary Information for estimating mobile and
area-source emissions. If a photochemical dispersion model Is to be used
as a primary tool 1n a non-attainment planning analysis, a region wide,
grldded emission Inventory Is needed. In this case, urban system
modeling Is the best way to generate the urban activity data necessary
for spatial and temporal resolution of emissions. In a non-attainment
planning effort, urban system modeling, If required, 1s usually conducted
by regional planning agencies.
Urban activity data required to project emissions Include the levels
and distribution of land use, population, employment, housing, and travel
activities. A system capable of producing the necessary Information Is
generally composed of the following types of models:
• Regional Projection Models
- Regional Demographic Model
- Regional Econometric Model, etc.
• Activity Allocation (Zone Level) Models
- Basic Employment Model
- Protective Land Use Model (PLUM)
- Urban System Model (USM)
- Empiric Model, etc.
• Travel Demand Forecasting Models
- Trip Generation Model
- Trip Distribution Model
- Modal Split Model
- Network Assignment Model, etc.
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The following is a compilation of several of the most widely used
models. A number of special-case models (i.e., the models which cannot
be easily applied to other non-attainment areas) are not included in the
list.
REGIONAL PROJECTION MODELS
ABA6 Regional Demographic Model (APPLE); ABAG Regional Econometric Model:
AQMP/Tech Memo 2, "Projections/Forecasting: System Description and
Technical Assumptions," Association of Bay Area Governments, Berkeley,
December, 1976.
Simple Economic Model:
Kogiku, K.C., "An Introduction to Macroeconomic Models," New York,
McGraw-Hill, 1968.
Input-Output Models:
Miernyk, W.H., "The Elements of Input-Output Analysis," New York, Random
House, 1967.
Other Models:
Comprehensive Planning Organization, "IPEF73, Interactive Population
Employment Forecasting Model, Technical User's Manual," San Diego,
California, March, 1974.
Puget Sound Governmental Conference, "Population and Employment Forecasts
and Distributions for the Central Puget Sound Region, 1975-1990,"
Seattle, Washington, 1972.
Lockfeld, F.M., "Short Term Projection of House Values, Rents and Income
for Small Areas: The Santa Clara County Housing Projection Model,"
Monterey, California, 1973.
Southwestern Pennsylvania Regional Planning Commission, "Forecasting
Framework: JOBS, PEOPLE, and LAND," Pittsburgh, PA, 1974.
Metropolitan Council, "Urban Activity Forecast Study Design," St. Paul,
Minnesota, 1971.
A-2
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,_____, A Summary of the Urban Systems Model. McLean, Virginia,
January, 1974. "
Access and Land Development Model (ALP):
Creighton, Hamburg, and Associates, Inc., et. al.. Summary Final Report -
Access and Land Development (ALP), prepared for Chicago Area
Iransportation Study, September, 19/4., Praft CATS Publication.
,^__^ , The Access and Land Development Model Technical Report,
Volume I -"Computer Software Documentation and Base Year Data Assembly,
Draft CATS Publication. ~~~
. The Access and Land Development Model Technical Report,
YoVume II - TheTalibration of the ALP Travel Function, Draft
Publication.
, The Access and Land Development Model Technical Report,
Volume III - Calibration and Evaluation of the ALP Equilibrium Model,
Praft CATS Publication.
, The Access and Land Development Model Technical Report,
Volume IV - Development and Testing of the ALP Dynamic Model, Draft CATS
Publication.
Land Use Allocation Model (LUAM):
Computer Sciences Corporation, LUAM - Land Use Allocation Model for Urban
and Transportation Systems Simulations.
Mahonlng - Trumben Counties Comprehensive Transportation and Development
Study Land Use Allocation Model, prepared for Mahonlng - Trumbell
Counties Comprehensive Transportation and Development Study of Ohio,
reprinted for Eastgate Development and Transportation Agency, by E.S.
Preston Associates, Inc., July, 1973.
Land Use Plan Design Model:
Southeastern Wisconsin Regional Planning Commission, A Mathematical
Approach to Urban Design, Technical Report No. 3, Waukesha, Wisconsin,
1966.
, A Land Use Plan Design Model - Model Development. Volume
Report No. 8, Waukesha, Wisconsin, 1968.
A Land Use Plan Design Model_ - Model Test. Volume 2,
Technical Report No. 8, wauicesha, Wisconsin, 1969.
, A Land Use Plan Design Model - Final Report. Volume 3.
Technical Report No. 8, wauicesha, Wisconsin, 1973.
validation and Test of a Land Use Plan Design Model. Department of Civil
Engineering, Marquette University, Milwaukee, Wisconsin, May, 1973.
1, Technica
A-3
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ACTIVITY ALLOCATION (ZONE LEVEL) MODELS
EMPIRIC Activity Allocation Model;
Peat, Marwick, Mitchell, & Co., EMPIRIC Activity Allocation Model:
Summary. Washington, D.C., April 1971.
. EMPIRIC Activity Allocation Model: Final Report.
prepared for the Metropolitan Washington Council of Governments.
Washington, D.C., May 1972.
, EMPIRIC Activity Allocation Model User's Manual,
prepared for the Federal Highway Administration (FHWA).Washington,
D.C., January, 1974.
Protective Land Use Model (PLUM):
Goldner, W., Protective Land Use Model, Institute of Traffic and
Transportation Engineering, University of California, Berkeley, 1968.
Goldner, W., et al, Protective Land Use Model: Volume 1 - Plan Making
With A Computer Model, Volume 2 - Theory and Application, Volume 3 -
Computer Systems GuTae, prepared by University of California for FHWA,
Urban Planning Division, 1972.
, Economic and Spatial Impacts of Alternative Airport
Sites and Locations In the San Francisco Bay Region, Institute of Traffic
and Transportation Engineering, University of California, Berkeley, 1971.
PLUM/SD The Urban Development Model: Volume 1 - A
Regional Planning Tool, Volume 2 - Technical Manual, Volume 3 - Computer
Systems Guide, prepared by San Diego Comprehensive Planning Organization
and Institute of Traffic and Transportation Engineering, University of
California, 1973.
Urban Systems Model (USM);
Turner, C.G., The Development of an Activity Allocation Model for the
Bristol Sub-ReigToh, Urban Systems Research Unit, University of Reading,
England, 1970.
Alan M. Voorhees & Associates, Inc., Application o. the Urban Systems
Model (USM) To A Region - North Central Texas, Volume 1; Conceptual
Basis of the USM And Application to The Planning Process, prepared for
the North Central Texas Council of Governments, McLean, Virginia,
October, 1972.
, Application of the Urban Systems Model (USM) to a Region
- North Central Texas, Volume II: Data Base, Calibration Procedure and
Results, prepared for the North Central Texas Council of Governments,
McLean, Virginia, December, 1972.
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NBER Urban Simulation Model:
Ginn, J. Royce, "The NBER Prototype Urban Simulation Model," paper
presented at the Convention of the American Institute of Planners,
October, 1971.
Ingram, G.K., Ka1n, J.F., and 61nn, J.R., The Detroit Prototype of the
NBER Urban Simulation Model, New York: National Bureau of Economic
Research, 1972.
Integrated Transportation and Land Use Models Package (ITLUP):
Putman, Stephen H., University of Pennsylvania, The Interrelationships of
Transportation Development and Land Development, volumes I and II,
prepared for the U.S. Department of Transportation, FHWA, Urban Planning
Division, June, 1973.
„-*»>,'•« • •
.i_ -J^""^i-1fc-'"
, "Further Results From, and Prospects for Future Research
With, the Integrated Transportation and Land Use Model Package (ITLUP),"
presented at the Annual Conference of the Southern Regional Science
Association, April 3-4, 1975, Atlanta, Georgia.
, "Calibrating a Disaggregated Residential Allocation
Model - DRAM: The Residential Submodel of the Integrated Transportation
and Land Use Package - ITLUP," presented at the Regional Science
Association - British Section, Eighth Annual Conference, September 4-5,
1975, London, England.
TRANSPORTATION SYSTEM MODELS
Trip Generation Models;
"Guidelines for Trip Generation Analysis," Federal Highway
Administration, Report No. HHP-22, Washington, D.C., June, 1967.
"Trip Generation Analysis," Federal Highway Administration, Report No.
HHP-20, Washington, D.C., August, 1975.
"Trip Generation by Land Use," Maricopa Association of Governments,
Marlcopa County, Arizona, April, 1974.
"Trip Generation," Institute of Transportation Engineers, 1976.
Trip Distribution Models;
"Calibrating and Testing a Gravity Model for any Sized Urban Area,"
Federal Highway Administration, Report No. HHP-20, Washington D.C '
October, 1965.
A-5
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"Urban Trip Distribution Friction Factors," Federal Highway
Administration, Report No. HHP-20, Washington, D.C., November, 1974.
"Computer Programs for Transportation Planning - PLANPAC/BACKPAC General
Information," Federal Highway Administration, Report No. HHP-20,
Washington, D.C., 1977.
Model Split Models;
"Modal Split, Documentation of Nine Methods for Estimating Transit
Usage," Federal Highway Administration, 1966.
"Introduction to Urban Travel Demand Forecasting," Urban Mass
Transportation Administration, NTIS-236-848/AS, March, 1974.
"Applications of New Travel Demand Forecasting Techniques to
Transportation Planning - A Study of Individual Choice Models," Federal
Highway Administration, March, 1979.
"Estimating Auto Occupancy, A Review of Methodology," Federal Highway
Administration, 1972.
Network Assignment Models:
"UTPS Network Development Manual," Federal Highway Administration, Covers
Network Assignment Computer Package Including ULOAD (Transit), LOADVN
(Highway), CAPRES (Highway Capacity Restraint), and others.
"Traffic Assignment," Federal Highway Administration, Report No. HHP-20,
August, 1973.
"Computer Programs for Transportation Planning - PLANPAC/BACKPAC General
Information Manual," Federal Highway Administration, Washington, D.C.,
1977.
GENERAL REFERENCES
Wilson, A.G., Urban and Regional Models in Geography and Planning. New
York: John Wiley and Sons, 1974.
Yupo Chan, et al, A Review of Operational Urban Transportation Models,
prepared for IT.S. DOT, Transportation System Center, Peat, Marwick,
Mitchell and Co., Washington, D.C., 1973.
Peat, Marwick, Mitchell & Co., _A_R_eview of Operational Urban
Transportation Models, Report No. DOT-TSC-496, prepared for U.S. DOT,
Transportation System Center. Cambridge, Massachusetts, April, 1973.
U.S. EPA, "A Guide to Models in Governmental Planning & Operations," U.S.
EPA, Office of Research and Development, Washington, D.C., 1974.
A-6
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U.S. DOT, An Introduction to Urban Development Models and Guidelines for
ineir Use in Urban Transportation Planning," Federal Highway
Administration, October, 1975.
fl'iT* I.n*roduction to Urban Travel Demand Forecasting," Federal Highway
Aomimstration and Urban Mass Transportation Administration, 1977.
piffivi MV, "Urban Modellin9 - Algorithms, Calibrations, Predictions,"
Cambridge University Press, Cambridge, 1976.
c?fnk« Jn R<> "ur?an Models: Diffusion and Policy Application," Regional
Science Research Institute, Philadelphia, 1978. "»•«"«,
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APPENDIX B
EPA CONTROL TECHNOLOGY GUIDELINE DOCUMENTS*
Control of Volatile Organic Emissions from Existing Stationary Sources
Volume V: Surface Coating of Large Appliances - EPA-450/2-77-034.
Control of Volatile Organic Emissions from Existing Stationary Sources
Volume IV: Surface Coating for Insulation of Magnetic Wire -
EPA-450/2-77-033.
Control of Volatile Organic Emissions from Bulk Gasoline Plants -
EPA-450/2-77-035.
Control of Volatile Organic Emissions from Existing Stationary Sources
Volume III: Surface Coating of Metal Furniture - EPA-450/2-77-032.
Control of Volatile Organic Emissions from Storage of Petroleum Liquids
In Fixed Roof Tanks - EPA-450/2-77-036.
Control of Volatile Organic Emissions from Solvent Metal Cleaning -
EPA-450/2-77-022.
Control of Hydrocarbons from Tank Truck Terminals - EPA-450/2-77-026.
Control of Refinery Vacuum Producing Systems, Wastewater Separators, and
Process Unit Turnarounds - EPA-450/2-77-025.
Control of Volatile Organic Compounds from Use of Cutback Asphalt.
Control Volatile Organic Emissions from Existing Stationary Sources
Volime II: Surface Coating of Cans, Colls, Paper, Fabrics, Automobiles,
and Light-Duty Trucks - EPA-450/2-77-008.
Design Criteria for State I Vapor Control Systems - Gasoline Service
Stations.
Control of Volatile Organic Emissions from Existing Stationary Sources
Volume I: Control Methods for Surface-Coating Operations
EPA-450/2-76-028.
*Reproduced from "workshop on Requirements for Non-Attainment Area
Plans—Compilation of Presentations," U.S. Environmental Protection
Agency, March, 1978.
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EPA 450/2-73-002 A Technique for Calculating Overall Efficiencies of
Particulate Control Devices. 8/73.
EPA 450/2-74-002A Background Information for New Source Performance
Standards: Primary Copper, Zinc, and Lead Smelters.
Vol. 1 - Proposed Standards. 10/74.
EPA 450/2-74-008 Air Pollution Control Engineering and Cost Study of
the Ferroalloy Industry. 5/74.
EPA 450/2-74-009A Background Information on National Emission Standards
for Hazardous Air Pollutants, Proposed Amendments to
Standards for Asbestos and Mercury. 10/74.
EPA 450/2-74-017A Background Information for Standards of Performance:
Electric Arc Furnaces in the Steel Industry. Vol. 1
- Proposed Standards. 10/74.
EPA 450/2-74-017B Background Information for Standards of Performance:
Electric Arc Furnaces in the Steel Industry.
EPA 450/2-74-018A Background Information for Standards of Performance:
Electric Submerged Arc Furnaces Producing
Ferroalloys. Vol. 1: Proposed Standards. 10/74.
EPA 450/2-74-018B Background Information for Standards of Performance:
Electric Submerged Arc Furnaces for Production of
Ferroalloys. Vol. 2: Test Data Summary. 10/74.
EPA 450/2-74-018C Background Information for Standards of Performance -
Electric Submerged Arc Furnaces for Production of
Ferroalloys. Vol. 3 - Supplemental Information.
4/75.
EPA 450/2-74-019A Background Information for Standards of Performance:
Phosphate Fertilizer Industry. Vol. 1 - Proposed
Standards. 10/74.
EPA 450/2-74-019B Background Information for Standards of Performance:
Phosphate Fertilizer Industry. Vol. 2: Summary of
Test Data. 10/74.
EPA 450/2-74-020A Background Information for Standards of Performance:
Primary Aluminum Plants. Vol. 1 - Proposed
Standards. 10/74.
EPA 450/2-74-020B Background Information for Standards of Performance:
Primary Aluminum Plants. Vol. 2: Summary of Test
Data. 10/74.
EPA 450/2-74-020C Background Information for Standards of Performance:
Primary Al urn in urn Industry. Vol. 3 - Supplemental
Information. 1/76.
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EPA 450/2-74-021A Background Information for Standards of Performance:
Coal Preparation Plants. Vol. 1: Proposed
Standards. 10/74.
EPA 450/2-74-021B Background Information for Standards of Performance:
Coal Preparation Plants. Vol. 2 - Summary of Test
Data. 10/74.
EPA 450/2-74-021C Background Information for Standards of Performance:
Coal Preparation Plants. Vol. 3 - Supplemental
Information. 1/76.
EPA 450/2-75-009 Standard Support and Environmental Impact Statement -
Emission Standard for Vinyl Chloride. 10/75.
EPA 450/2-75-009B Standard Support and Environmental Impact Statement:
Volume 2 Promulgated Emission Standard for Vinyl
Chloride. 1976.
EPA 450/2-76-002 State Implementation Plan Emission Regulations for
Sulfur Oxides - Fuel Combustion. 3/76.
EPA 450/2-76-012 Field Evaluation of Reid Jacket Vapor Control System.
1976.
EPA 450/2-76-014A Standards Support and Environmental Impact Statement:
Yol. 1 Proposed Standards of Performance for Kraft
Pulp Mil Is. 1976.
EPA 450/2-76-016A Standards Support and Environmental Impact Statement:
Vol . 1 Proposed Standards of Performance for
Petroleum Refinery Sulfur Recovery Plants. 1976.
EPA 450/2-76-028 Control of Volatile Organic Emissions from Existing
Stationary Sources: Vol. 1 - Control Methods for
Furnace Coating Operation. 1976.
EPA 450/2-76-030A Standards Support and Environmental Impact Statement:
Vol. 1 - Proposed Standard of Performance for
L1gn1te-F1red Steam Generators. EPA: OAQPS 1976.
EPA 450/2-77-001A Standards Support and Environmental Impact Statement:
Vol. 1 - Proposed Standards of Performance for the
Grain Elevator Industry. EPA: OAQPS 1977.
EPA 450/2-77-005 Control of Fluoride Emissions from Existing Phosphate
Fertilizer Plants: Final Guideline Document. EPA:
OAQPS 1977.
EPA 450/2-77-007A standards Support and Environmental Impact Statement:
Vol. 1 - Proposed Standards of Performance for Lime
Manufacturing Plants. EPA: OAQPS 1977.
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EPA 450/2-77-008 Control of Volatile Organic Emissions from Existing
Stationary Sources: Vol. II - Surface Coating of
Cans, Coils, Paper, Fabric, Automobiles and Light
Duty Trucks. EPA: OAQPS 1977.
EPA 450/2-77-019 Final Guideline Document: Control of Sulfuric Acid
Mist Emissions from Existing Sulfuric Add Production
Units. EPA: OAQPS 1977.
EPA 450/2-77-022 Control of Volatile Organic Emissions from Solvent
Metal Cleaning.
EPA 450/2-77-025 Control of Refinery Vacuum Producing Systems -
Wastewater Separators: Process Unit Turnarounds.
EPA 450/2-77-026 Control of Hydrocarbons from Tank Truck Gasoline
Loading Terminals.
EPA 450/2-77-032 Control of Volatile Organic Emissions - Surface
Coating Vol. III.
EPA 450/2-77-033 Control of Volatile Organic Emissions - Magnetic Wire
Vol. 4.
EPA 450/3-73-003A Emissions Control in the Grain and Feed Industry,
Vol. 1. Engineering and Cost Study. 12/73. Midwest
Research Inst. 1973.
EPA 450/3-73-003B Emissions Control in the Grain and Feed Industry.
Vol. 2. Emission Inventory. 9/74. Midwest Research
Inst. 1974.
EPA 450/3-73-004A Air Pollution Control 1n the Primary Aluminum
Industry. Vol. 1 of 2 (Sections 1 through 10).
7/73. Singmaster and Breyer. 1973.
EPA 450/3-73-004B Air Pollution Control in the Primary Aluminum
Industry. Vol. 2 of 2 (appendices). 7/73.
EPA 450/3-74-002 Evaluation of the Controllability of Power Plants
Having a Significant Impact on Air Quality Standards.
2/74.
EPA 450/3-74-015 Factors Affecting Ability to Retrofit Flue Gas
Desulfurization Systems. 12/73. Radian Corp. 1973.
EPA 450/3-74-036A Investigation of Fugitive Dust: Vol. I - Sources,
Emissions, and Control. PEDCo Env. Specialists.
1974.
EPA 450/3-74-036B Investigation of Fugitive Dust: Vol. II - Control
Strategy and Regulatory Approach. PEDCo Env.
Specialists. 1974.
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EPA 450/3-74-060 Air Pollution Control technology and Costs - Seven
Selected Emission Factors. 12/74. Indust. Gas
Cleaning Inst. 1974.
EPA 450/3-74-063 Participate Emission Control Systems for Oil-Fired
Boilers. 12/74. Geomet. 1975.
EPA 450/3-75-046A A Study of Vapor Control Methods for Gasoline
Marketing Operations. Vol. 1 - Industry Survey and
Control Techniques. 4/75. Radian Corp. 1975.
EPA 450/3-75-046B A Study of Vapor Control Methods for Gasoline
Marketing Operations. Vol. 2 - Appendix. 4/75.
Radian Corp. 1975.
EPA 450/3-75-047 Comparison of Flue Gas Desul furl zatlon Coal
Liquefaction and Coal Gasification for Use at
Coal-Fired Power Plants. Kellogg MS Co. 1975.
EPA 450/3-76-005 Control of Partlculate Matter from 011 Burners and
Boilers. Aerotherm Corp. 1976.
EPA 450/3-76-013 Cost of Retrofitting Coke Oven Partlculate Controls.
Vulcan Cincinnati. 1974.
EPA 450/3-76-036 Evaluation of Methods for Measuring and Controlling
Hydrocarbon Emissions from Petroleum Storage Tanks.
Battelle Memorial Inst. 1976.
EPA 450/3-76-038A Background Information on Hydrocarbon Emissions from
Marine Terminal Operations: Vol. I - Discussion.
Radian Corp. 1976.
EPA 450/3-76-038B Background Information on Hydrocarbon Emissions from
Marine Terminal Operations: Volume II - Appendices
Radian Corp. 1976.
EPA 450/3-76-042 Economic Impact of Stage II Vapor Recovery
Regulations: Working Memoranda. Little Ad. 1976.
EPA 450/3-77/-010 Technical Guidance for Control of Industrial Process
Fugitive Partlculate Emissions. PEDCo Env.
Specialists. 1977.
EPA 450/3-77-026 Atmospheric Emissions from Offshore Oil and Gas
Development and Production, Energy Resources Co.
1977.
EPA 450/3-77-046 Screening Study to Determine Need for SOx and
Hydrocarbon NSPS for FCC Regenerators.
B-5
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TECHNICAL REPORT DATA
(Please read Inslructions on the reverse before completing)
1. REPORT NO.
FPA-45n/?-7Q-nnia
2.
4. TITLE AND SUBTITLE
Example Control Strategy for Ozone, Volume I:
General Guidance to Nonattainment Areas
3. RECIPIENT'S ACCESSIOr»NO.
5. REPORT DATE
April, 1979
6. PERFORMING ORGANIZATION CODE
7. AUTHOR(S)
8. PERFORMING ORGANIZATION REPORT NO
OAQPS No. 1.2-120
9. PERFORMING ORGANIZATION NAME AND ADDRESS
10. PROGRAM ELEMENT NO.
Association of Bay Area Governments
Environmental Quality and Energy Resources Department
Hotel Claremont
Berkeley, California 94705
11. CONTRACT/GRANT NO.
68-02-3001
12. SPONSORING AGENCY NAME AND ADDRESS
U.S. Environmental Protection Agency
Office of Air Quality Planning and Standards
Research Triangle Park, North Ca/olina 27711
13. TYPE OF REPORT AND PERIOD COVERED
Final
14. SPONSORING AGENCY CODE
15. SUPPLEMENTARY NOTES
Association of Bay Area Governments Project Manager:
EPA Project Officer: Andrew Creekmore
Eugene Leong
16. ABSTRACT
This guideline presents information to assist States and local agencies in
preparing ozone control strategies for nonattainment areas. The guidance should
be most useful in preparing 1982 State Implementation Plan revisions.
The guideline covers the following topics: Intergovernmental Cooperation,
Development and Assessment of Air Quality and Emissions Data, Modeling to Related
Air Quality to Emissions, Control Strategy Analysis and Assessment, Plan Adoption,
and the Continuing Planning Process. This volume covers general guidance to
nonattainment areas.
7.
KEY WORDS AND DOCUMENT ANALYSIS
DESCRIPTORS
b IDENTIFIERS/OPEN ENDED TERMS
c. COSATI Field/Group
Air Pollution
Atmospheric Contamination Control
Ozone
State implementation
plan control strategy
National ambient air
quality standard
8. DISTRIBUTION STATEMENT
19. SECURITY CLASS (This Report)
Unclassified
21. NO. OF PAGES
139
Unlimited
20. SECURITY CLASS (Thispage)
Unclassified
22. PRICE
EPA Form 2220-1 (9-73)
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