EPA-450/3-76-009 September 1
PROCEEDINGS OF THE CONFERENCE
AIR QUALITY IMPACT ANALYSIS
FOR APPLICATION IN LAND USE AND
TRANSPORTATION PLANNING
\
SEPTEMBER, 1975
Office of Air and Waste Management
Office of Air Quality Planning and Standards
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Proceedings of the Conference
I AIR QUALITY IMPACT ANALYSIS FOR APPLICATION IN
LAND USE AND TRANSPORTATION PLANNING
* June 24 -26,1974
I Berkeley, California
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CONFERENCE COORDINATORS
Richard H. Thuillier
George Hagevik
PROCEEDINGS EDITOR
Elaine T. Hussey
Continuing Education in City, Regional, and Environmental Planning
University Extension, University of California, Berkeley
With the Assistance of the
United States Environmental Protection Agency
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This conference report has been reviewed by the Office
of Air Quality Planning and Strategies, linvironmental
Protection Agency, and approved for publication. Approval
does not signify that the contents necessarily reflect
the views and policies of the linvironmental Protection
Agency, nor does mention of trade names or commercial
products constitute endorsement or recommendation for use.
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Preface
This conference was supported in part by EPA Air Pollution Training
Grant Number T-900345 from the Air Pollution Training Institute, Research
Triangle Park, North Carolina 27711. The unstinting efforts of the
following individuals in their respective roles are gratefully acknowledged.
PROGRAM COORDINATORS
Richard H. Thuillier, Chief of Research and Planning, Bay Area Air
Pollution Control District, San Francisco
George Hagevik, Chief of the Environmental Resources Division,
Association of Bay Area Governments (ABAC), Berkeley
INSTRUCTIONAL STAFF
Howard Harawitz, Air Pollution Engineer, Bay Area Air Pollution
Control District, San Francisco
Warren B. Johnson, Assistant Director, Atmospheric Sciences
Laboratory, Stanford Research Institute, Palo Alto
David A. Levaggi, Director of Technical Services, Bay Area Air
Pollution Control District, San Francisco
Daniel Lieberman, Program Manager, Land Use Planning Program,
California Air Resources Board, Sacramento
Daniel Mandelker, Professor of Law, School of Law, Washington
University, St. Louis
Ralph A. Mead, Senior Planner, Bay Area Air Pollution Control
District, San Francisco
Elaine T. Hussey, Planning and Management Consultant, Berkeley
MILTON R. STERN, DEAN
University Extension} University of California, Berkeley
WARREN W. JONES, CHAIRMAN
Continuing Education in City, Regional}and
Environmental Planning
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Table of Contents
INTRODUCTORY STATEMENT
R. Thuillier
KEYNOTE ADDRESS - AIR QUALITY AND LAND USE 1
D. Morrell
Introduction
Transportation Control Plans
Indirect Source Regulations
Air Quality Maintenance Plans
Localization of Air Quality Efforts
Air Quality Land Use and Institutional Structures
Conclusion
AIR QUALITY MANAGEMENT AND LAND USE REGULATION 21
D. R. Mandelker
The Clean Air Act and Land Use
Complex and Indirect Source Review
Local and Regional Roles Within the Framework of the
Clean Air Act
NEPA and CEQA
Summary
References Cited
INSTITUTIONAL ISSUES IN AIR QUALITY MANAGEMENT 35
G. Hagevik
Basic Questions
Air Quality Maintenance
The Air Quality Maintenance Process
Emission Allocation Planning
Air Quality Analysis at the Project Level
References Cited
AIR QUALITY CONSIDERATIONS AND LOCAL LAND USE PLANNING 49
R. Mead
Growth Policies
Land Use Policies
Transportation Policies
Land Use Planning Methodology
Development Timing Considerations
Quantifying the General Plan
"VMT" Reduction
A Personal Perspective
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EMISSIONS ALLOCATIONS: A NEEDED FRAMEWORK FOR RELATING 73 I
AIR QUALITY CONTENT OF EIRs TO DECISION MAKING
D. Lieberman
Introduction |
Interrelation of the Land Use and Transportation
Planning Processes
The Emissions Allocation Process I
Conclusion
Bibliography
TRANSCRIPT OF THE PANEL DISCUSSION - INTERACTION OF THE PLANNING 81 I
AND REGULATORY COMMUNITIES
GENERAL ASPECTS OF AIR POLLUTION 109 |
D. Levaggi
AIR POLLUTANT EMISSIONS AND EMISSION FACTORS 157
H. Harawitz
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Introduction
Air Pollution
Stationary Pollutant Sources
Mobile Pollutant Sources
Ambient Air Standards
Conclusion
Bibliography
THE ROLE OF METEOROLOGY IN AIR QUALITY 123
R. Thuillier
Introduction
Weather Systems and Pollutant Episodes
Weather Elements and Pollutant Dispersion
Visibility and Air Quality Awareness |
Conclusion
THE STATE OF THE ART IN AIR QUALITY MODELING 133 I
W. Johnson and R. Thuillier
Introduction
Air Quality Modeling in the Decision Making Process
Basic Modeling Approaches
Modeling Resolution
Conclusions and Recommendations p
Bibliography
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Introduction
Pollutant Source Categories
Emission Factors and Emission Rates
Computation of Emissions
Use of Emissions Data I
References Cited
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METEOROLOGICAL MODELING INPUT 169
R. Thuillier
Introduction
Mixing Height Characteristics
Air Flow Characteristics
Stability Characteristics
Pollutant Level Variability as a Meteorological Parameter
References Cited
SIMPLIFIED TECHNIQUES FOR AIR QUALITY IMPACT QUANTIFICATION 187
R. Thuillier
Preface
Introduction
Modeling Rationale
Analysis Techniques for Non-Project Sources
Analysis Techniques for Project-Related Sources
Concentrations, Averaging Times and Recurrence Frequencies
Analysis Techniques for Reactive Pollutant Species
Regional Modeling Applications
Model Accuracy and Model Tuning
References Cited
Appendix A - A Note on Formula Derivation
Appendix B - Summary of Simplified Formulas
ELEMENTS OF AN ADEQUATE IMPACT PRESENTATION 237
R. Mead
Introduction: NEPA and CEQA
Description of Existing Conditions
Project Description
Project Traffic Study
Other Anticipated Local Development
Air Quality Impact Analysis
Mitigation Circumstances
Alternative Intensities, Uses and Sites for the Project
Growth Inducing Effects of the Project
TRANSCRIPT OF THE PANEL DISCUSSION - CRITIQUE OF SAMPLE IMPACT 257
REPORTS
DISCUSSIONS OVER LUNCH JUNE 26, 1974 279
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INTRODUCTORY STATEMENT
Richard H. Thuillier
Good morning! I greatly relish and appreciate the opportunity to
welcome you here and to set the tone for this short course in Air Quality
Impact Analysis. As we indicated in our brochure, the purpose of this
course is to bring a workable air quality analysis approach to the
I attention of an extended segment of the user community. The desire to
do this was stimulated by local requests for assistance, indicating that
the copious published material relating to air quality analysis was not
imparting a clear message or indicating a discernible direction. The
very gratifying and somewhat unexpected attendance here would seem to
bear out the existence of a gap between the development and application
of techniques. We hope and will certainly attempt to insure that you
leave here on Wednesday with an improved albeit imperfect knowledge in
this respect.
The story to be told in this course is structured, as is any good
story, with a beginning, a middle and an end. In the beginning there
was the Clean Air Act, NEPA, CEQA, etc., forming the framework of the
I legislative and regulatory approach to the attainment and maintenance
j of a high level of air quality. The bulk of this first day will be
devoted to an examination of the setting in which the air quality analysis
requirement exists. We will examine the legislation and regulations,
particularly as they bear upon land use and transportation. We will
I discuss the relationship and interaction between the planning and
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regulatory communities. Finally, we will apprise you of the expectations |
of agencies currently responsible for setting policy and with the prospects _
for future evolution of the air quality management process. After the
setting is established, we will introduce the very technical business of
assessing air quality impact by discussing the nature of the pollutants
with which we must deal and the atmospheric processes which transform I
pollutant emissions into health or welfare related concentrations.
On the second day, we will concern ourselves exclusively with pro-
cedures for assessing the impact of land use and transportation projects
upon the quality of the air. Since standards have been set in very
quantitative terms, it is essential that decision making aimed at
achieving or maintaining these standards be provided with information
which is also quantitative in nature. Such information should be obtained
on a systematic and scientific basis, concern itself with all relevant
pollutants and be presented in a form which is readily evaluated in terms
of applicable standards. While an exact technique for accomplishing this I
task may never exist, there does exist a variety of techniques which
yield approximate solutions quite suitable for effective decision-making.
Our second day will explore the entire state of the art in air quality
analysis but will concentrate on simplified methods since adequate and
meaningful air quality analysis is the responsibility of the pauper as
well as of the prince. Our intent is to provide an alternative to the
choice between a costly, esoteric and time consuming analysis and no |
analysis at all. mt
We will conclude our story on the third day by discussing appropriate
procedures for the written presentation of analysis results. The emphasis I
will be on environmental impact statements and reports and the discussion
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will include both quantitative and qualitative aspects of the analysis.
A focus for the discussion will be provided via a critique of sample
I impact reports indicating the faults and merits of some of the impact
reporting to date. Our story thus completed, we will view our perfor-
mance through the looking glass of our audience so that we too can learn
£ from our experience. As in any first effort, we anticipate many wrinkles
which will have to be ironed out. We welcome your suggestions in so
I doing.
Due to the great number of participants, which in all honesty ex-
I ceeded our greatest expectations, we would like to beg your indulgence
« in a couple of areas in which our performance will probably fall short
of your expectations. We have attempted to provide each of you, free
of charge, a small library of the published material which we feel is
basic to the process of air quality analysis. This material will be
| available at the beginning of the session on the second day. Our second
p request for indulgence concerns audience participation. We ask you to
reserve any philosophical discussion for the lunch, coffee break and
I cocktail hour periods so that we may get through the material we have to
present. The speakers will attempt to provide some of their alloted
time for questions and answers.
_ With that, I conclude my introduction, wish you all a profitable
' experience and return the podium to Dr. Hagevik who will introduce the
next speaker. Thank you for your kind attention.
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KEYNOTE ADDRESS
AIR QUALITY AND LAND USE
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David Morell
Introduction
I would like this morning to set the stage for some of the issues
to be covered during the next two days of this seminar by exploring with
I you three sides of a triangle: one side is Air Quality and the second
side Land Use. The third side involves Intergovernmental Relations, the
institutional structures which perform the integration, hopefully, of
air quality concerns with land use decisions. The challenge of
institutionalization to cope with these new issues is particularly
important. We face the need to create new institutional structures, or
at least to use our existing institutions in new ways. In integrating
" air quality and land use, a vertical institutional network is required.
Traditionally, the functional federalism of the next fifteen or
twenty years has coped with--or tried to cope with--the problems in our
metropolitan areas through creation and support of horizontal, area-wide
structures. But how do we join land use decisions, traditionally made
9 at city and county levels, with air quality standards, regulations, goals
and objectives which traditionally emanate from federal and state levels?
Our need is to effect a vertical synthesis of these two activities.
I would like to review some of our activities at the federal
Environmental Protection Agency concerning four of the air pollution
control programs which affect land use: Transportation Control Plans,
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Indirect Source Reviews, Air Quality Maintenance Plans, and regulations m
to prevent Significant Deterioration of air quality in clean-air areas.
Before I go into these programs, however, it seems only fitting
that we examine where we've been in EPA relationships with states and
cities and counties, through a story--an analogy, if you will--that I
think hopefully sets the stage for vastly different relationships in |
the future. This is the story of the hippopotamus that fell in love ^
with the pigeon; but he didn't know quite what to do to effectuate this
relationship. So, he went to see the wise old owl, and he said,
"Listen, Mr. Owl, I have a problem; I'm in love with a pigeon and I
don't know what to do." The owl, being a wise old owl, scratched his
beak, and he thought, and he said finally, "Listen, Hippo, there's only _
one thing you can do: turn yourself into a pigeon." Well, the Hippo *
nodded his head, and he thought that sounded like good advice, and V
he lumbered away down the forest path. As he was walking away it
dawned on him, "Well, I was given good advice, to turn myself into a I
pigeon; but how do I do that?" So he turned around and went back to the
wise old owl, and he said, "Look, you told me to turn myself into a
pigeon; how do I do that?" And the owl looked him right in the eye and
he said, "Listen, Hippopotamus, I only make policy, I don't implement it!"
Well, too often in the past, that's where we've been in EPA
relations with state and local governments. Under the mandates of the
Clean Air Act of 1970, we have engaged in a good deal of publication of
regulations in the Federal Register; we have been making policy. Who's
going to implement it? What kind of institutional structures, procedures,
commitments, political will, taxing authority and financing are to be I
involved? We have to move now from regulations--policy, if you will--
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_ such as 38 transportation control plans across this country, including
much of California, to a mode of implementation, taking these plans and
I saying, how do we move from a plan to cleaner air, to a reduction in
photo- chemical oxidants in the air here around the Bay Area, or in
| California's South Coast Air Basin, or in Denver. So this story from
^ the animal kingdom really sets the stage for where I think we want to
go together, between the federal government and state and local
governments, in terms of institutionalization and implementation of
these programs.
I One other concept that forms the basis for understanding the
relationship between air quality and land use is to view a hierarchy of
B three objectives in the Clean Air Act in terms of air quality:
m attainment, maintenance, and preservation. Attainment of what?
Attainment of national ambient air quality standards, which have been
established for six criteria pollutants. In the areas which are now
dirtier than the standards, therefore, we are talking about techniques,
8 technology, land use review, whatever, to attain the standards as
expeditious ly as possible; under the present mandate of the Clean Air
Act, by July 1, 1977, at the latest. Thus one of the main goals, and
in many ways the first significant goal of the Clean Air Act, involves
attainment of national standards. Once attained, the second goal comes
| into effect: maintenance. These two goals, however, must and will
« relate to one another in actual practice. In other words, while you're
in an attainment phase, you need to be taking certain actions to insure
that you can maintain that air quality, once you get there. We can't
suddenly switch from attainment to maintenance on the day when you
| hit that line, the national standard. Instead we must begin creating a
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political process, and a decision making process now in the South Coast I
Air Basin looking toward maintenance of air quality in the 1980's.
Therefore, when we talk about an Air Quality Maintenance Plan (ACMP) as |
needed for maintenance standards, we might as well change the "M" to
Management in some of the very heavily impacted areas like the South
Coast Air Basin. This air quality management plan involves the same H
process and the same procedures as the air quality maintenance plan.
The third objective, preservation, is my shorthand for the phrase that I
is so lengthy in the court orders and the discussions: "prevention of
significant deterioration of air quality." Preservation is the objective
in areas where the air is cleaner than the standards. Normally, these
are rural areas, occasionally elsewhere. What special steps ought to be
taken to preserve that air quality? Later I'11 describe some of the I
procedures we are attempting to devise in this area of air quality
preservation.
Transportation Control Plans J
All four of the programs I named earlier deal in one way or another «
with the integration of air quality concerns into state and local land
use planning and decision making. Transportation control plans are I
primarily oriented toward the attainment objective. They deal with
the pollutants associated with automobiles, and contain a wide variety J
of measures, some of which have been highly controversial. The plans _
include measures to influence the pattern of automobile transportation *
in 38 of our largest metropolitan areas heavily impacted by auto
pollution. These measures are designed to shift people over time out of
automobiles into buses, fixed rail systems, car pools, bicycles, their I
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_ own feet, whatever. The volume of auto traffic, its density and conges-
tion and the overall vehicle miles traveled ^vMT) are causing the vast
majority of the air pollution problems in those cities.
Some measures in the transportation control plans are highly
g technological, such as the retro-fit of emission control devices on
_ older cars. Inspection and maintenance of automobiles is very important.
Although we have had our problems in achieving a cleaner car, the newer
ones are certainly much cleaner than the ones made five years ago.
Inspection and maintenance programs ensure that the technology we've
paid for on the newer cars is at least in working order, rather than
allowing these devices to deteriorate. The plans call for improvements
to mass transit, and because of the time frames of the Clean Air Act for
attainment of standards, we're talking primarily about buses and car
pools. There are car pool incentive schemes, moral suasion and
caj oiling to attempt to attempt to obtain additional car-pooling in lieu
of one-man, one-car commuting. Transportation control plans call for in-
creased numbers of buses and improved bus service. One of the ways you
improve the attractiveness of the bus is to move it faster than a car.
So some plans require exclusive bus lanes, which can move car pools
and buses across a bridge, like the Bay Bridge, or down an expressway
like the Shirley Highway in Washington, much more rapidly than the
| congested automobile traffic and thereby might induce somebody to get
M out of their car and into the bus. We're also working closely with the
Department of Transportation on financing for bus system improvements.
And we're talking, or at least certainly did talk last year, about a
variety of disincentives, because as the buses become available, one
| is faced with the question of "How do you encourage people who have
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grown up in an automobile culture, in a suburban bedroom community where I
all mobility relies on automobile traffic, to use the bus more frequently?"
One way, we felt, was through a variety of disincentive measures. One
of these was called a parking surcharge, which can be very effective. It
didn't receive a very favorable reception here in the state of California,
to put it mildly. I
The parking surcharge controversy is an excellent example of EPA's
desire to have local governments develop programs, policies, plans, I
techniques of their own that they're committed to. It is also an
excellent example of what happens when they don't. Under the Clean
Air Act, EPA must promulgate these plans, such as a transportation
control plan including the parking surcharge. The local government,
or the political constituency, if you will, essentially has two choices: |
one is to say, "Allright, we don't want the Feds to do that, so we'll M
do it ourselves, we'll get organized and prepare our own plan." The
other alternative is to say, "We don't want the Feds to do that, so
we'll call our congressman and object." Well, with the parking surcharge
it's fairly clear that the second choice was the one selected. During JJ
December and January last winter, there was a great deal of pressure g
from Congress to rescind the parking surcharge, and on January 15th,
EPA did so. V
The auto-related air pollution problem is so severe in California
in terms of having any chance of approaching the standard by the dates g
mandated in the Clean Air Act, that major and provocative actions were ^
needed; and these were included in the California plans. For example,
in areas where there is already, or where there is projected to be, mass
transit availability, such as parts of a central business district, a
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selective parking surcharge used only against 8-hour parkers, not against
shoppers, could be both effective and reasonable. There are ways to do
this, applying the surcharge only at certain times of the morning, and
only for commuters who are going to park for 8 hours. This could be an
| essential step toward increasing the load factor on buses. Used broad-
« scale, as in the California plans, the surcharge would again be a
political disaster. But used selectively it is an effective device not
only providing a model shift from one-man, one-car into mass transit,
or into a carpool as a way to share the cost of the surcharge with your
neighbor, but the surcharge would provide the revenue needed to cover
the operating deficit on the buses. This subsidy is a very significant
issue with which the Congress, DOT, and EPA are still groping, in terms
of its implications for incentives for management efficiency of bus
systems.
I Other components of the management of parking supply continue to be
emphasized by EPA in the transportation control plans. New parking-
related facilities in areas heavily impacted by auto pollution must
undergo pre-construction review to ensure that all reasonable steps have
been taken to minimize the new facility's impact on vehicle miles
traveled and to ensure that localized carbon monoxide standards are not
violated. It is EPA's intention that state and local governments begin
to carry out these source-by-source parking management reviews, either
ft through adoption of their own legal requirements or through delegation
of EPA's authority. Until this happens, however, EPA is responsible for
implementing these review procedures.
Furthermore, EPA is emphasizing development by the affected local
I jurisdictions of comprehensive Parking Management Plans to provide the
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analytical framework for these source-by-source reviews. VMT is an I
areawide problem, which can best be viewed in this context. Although
EPA is not by itself going to develop Parking Management Plans, we are «
encouraging local jurisdictions to do so.
Perhaps that's enough on transportation control plans. They're
terribly important. They pose major challenges for implementation by I
state, regional, county and city officials. They contain a variety of
measures which in general are not yet fully integrated with one another.
One factor I have realized more and more, and I encourage you all to
assess: any single measure by itself isn't going to be enough. Parking
surcharge, more buses, inspection and maintenance.. .what we need is an I
orchestration of these measures, integrating them so that they support
one another, and as a whole take us where we need to go in terms of I
air quality.
Indirect Source Regulations ^
Let us turn now to the indirect source regulations. An indirect
source is a facility which itself does not pollute, but which attracts
or may attract large amounts of automobile traffice: shopping centers,
parking lots, stadiums, commercial and industrial facilities, recreation-
al areas, highways, airports. These are facilities that can cause
violations of the national standards for carbon monoxide due to
automobile congestion in and around the facility, particularly into and
out of the parking lot associated with the large regional shopping
center, for example. We are requiring the developer to examine
features for automobile entrance to and egress from that parking lot.
Does it have only two entrances, one on each end; or is there one on each
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« corner, plus in the middle? What's the flow of traffic, and what can be
done to avoid congestion? We believe that basically it is congestion
I that causes localized carbon monoxide violations, and that this design
issue can be handled in the planning stages of a shopping center or
a commercial facility. The focus is on traffic design to avoid
_ congestion and thereby prevent possible violation of the localized
* carbon monoxide standards. Large new airports and highways will also
be reviewed to ensure their consistency with national standards for
photo-chemical oxidants (the VMT issue), as are other parking-related
facilities in the transportation control plan areas.
Pre-construction review and issuance of a permit is required for
all indirect sources which begin construction on or after January 1, 1975.
As of July 1st we in EPA will be available officially to begin to consult
with developers on this matter. The applicable regulations in the
Federal Register were dated February 25th this year, and a revised set
will be issued in early July.
As with parking management, EPA is deeply committed to state and
local government implementation of the indirect source regulations.
Again, this can occur either through EPA approval of locally-adopted
review regulations, or through direct delegation of EPA's review
authority under the Clean Air Act.
Air Quality Maintenance Plans
U Air Quality Maintenance Plans, or as noted in some areas really Air
Quality Management Plans, are a very important element of the overall
program. These plans have been little discussed by the concerned public,
certainly less than indirect source reviews and parking management. This
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is somewhat ironic, for in the long run the Air Quality Maintenance Plans
may be far more important. Perhaps this difference in emphasis occurs
because shopping center owners and developers feel deep and direct con-
cern about what EPA is going to do with their new facilities proposed
to start construction next year, whereas an Air Quality Maintenance Plan
sounds like a process air quality planners carry out in a corner
somewhere, sometime in the future. Air Quality Maintenance Plans
broaden the analytical scope of source-by-source pre-construction reviews
of indirect sources, parking lots, and single highways in two critical
dimensions. Geographically, the plan covers the entire relevant problem I
shed, or air basin. For example, the entire Bay Area or the entire South
Coast Air Basin of California, with parts or all of six counties and I
scores of component cities would be covered under one air quality
management structure. This poses directly the question of institutional-
ization: "Who is going to prepare and implement an Air Quality
Maintenance Plan in the Los Angeles area?" The second dimension being
broadened from source-by-source reviews is the temporal one. The Air |
Quality Maintenance Plan, or management plan, takes today's air quality
problem, projects growth over the 1975-85 decade and assesses what that
growth is going to mean for air quality. Essentially this process I
involves looking at two curves: one is the growth curve, of increased
emissions; the other is the technological reduction curve, whether |
through cleaner automobiles or scrubbers or whatever, to reduce ^
pollution per source. Thus there are both a per-source reduction curve **
and a growth-related aggregate increase curve. For example, one of the fl
problems with automobile pollution is that as we get increasingly
cleaner new cars, we also have more cars on the roads. The Air Quality |
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_ Maintenance Plan takes today's problem, projects those two curves out,
and sees that if there are going to be violations of national air quality
fl standards during the 1975-85 period, then regulations, techniques,
devices, procedures, decision making bodies, whatever must be developed
I to get air quality down to the health-related national standards and
keep it there. These plans represent a terribly important air quality
management device, replete with implications for institutional procedures.
Prevention of significant deterioration, or "preservation" of air
quality, is the fourth air quality program which impacts on land use.
EPA was faced with a court order last year which said that in addition to
attaining and maintaining national standards of air quality, the federal
Environmental Protection Agency in concert with the states had to
promulgate regulations to prevent significant deterioration of air quality
in areas presently cleaner than the standards. These regulations
essentially affect rural areas and deal with developments related to
the energy supply situation in this country: power plants, oil refiner-
I ies, and other essential elements of increasing the supply of energy.
Because of the complexity of this issue, EPA decided to innovate. You're
supposed to go into the Federal Register with a proposed regulation,
review public comments, modify the regulation, and then promulgate a
final regulation. In air quality preservation, on September 16, 1973,
| EPA placed in the Federal Register a proposed regulation which contained
mm four alternatives, and accepted public comments on all four. We have
received extension public comment, and we've had a continuing series of
discussions within this Administration regarding the role of the federal
government in this issue. The Administration had wanted a Clean Air Act
I amendment which would remove the federal government from the preservation
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issue and explicitly leave all of it to the states. Administrator Train
found himself unable to accept this, and so it was sent up to the Congress *
not as a proposed amendment but as an issue for Congressional discussion.
The Congress is deeply interested in this issue, and several federal
agencies are quite interested in it. We're now in the process of getting I
ready to re-propose one alternative which sets out a national procedural
framework for land use and area classification by the states on the basis
of air quality and other goals and then for the review of new sources in
19 categories. These exclude the automobile pollutants, but do cover
power plants, oil refineries, smelters, and other categories, essentially
the "big dirties" of stationary source pollution. The regulation sets
out techniques for new source review of these categories against
stipulated increments. But the system is sufficiently flexible that at
levels below the national standards trade-offs can be made by the states,
balancing socio-economic benefits against air quality degradation. At
least there is a national framework, which in many ways forms a pretty
good model for relating land use to environmental quality. Land use I
choices in cities, counties, and states have to reflect a broad range
of community goals: employment, income, tax-ratable base, as well as
environmental goals. As we look back over recent history, it seems
clear that the environmental goals tend to have been neglected by most
land use decision makers. So these preservation regulations inject |
them into the system. M
Localization of Air Quality Efforts
In many ways, the issue in all four of these programs is how to
institutionalize these air quality efforts related to land use at the
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governmental echelon where these decisions have traditionally been made:
in the cities and counties. How do we avoid the federal government
making these decisions, instead of the counties and cities. Legislation
tends to arrive in the Congress in two sets of relationships: action/
reaction (the typical physics principle); and inaction/reaction. The
Clean Air Act falls into the second category. The Act of 1967 had a lot
I of nice words, patted everyone on the back, and very little happened.
m 1970 came around and the Congress produced a very strong act. Thus
inaction led to reaction. However, if we find the federal government--
in the person of EPA--attempting to make all land use decisions in this
nation, we will then witness an example of action leading to reaction.
| How do we institutionalize these measures to adequately preserve
M and protect air quality--attainment, maintenance, and preservation--
through land use decision making, recognizing that as many decisions as
I possible should continue to be made where they've traditionally been made,
in the cities and counties. At the same time we must ensure that two
J other things occur: First, that these national air quality standards are
_ achieved expeditiously, in all areas, and are maintained in the face
of new growth. Second, and equally troublesome, how are these decisions
made in the cities and counties while still adequately taking care of the
externalities, the fact that air pollution blows all over across
jurisdictional boundaries? How do these decisions get made where they
have been made, where they ought to be made, and sill insure that they
adequately reflect our new environmental air quality concerns?
It might be easier if a city had to live with its own pollution; in
this event, the city's constituents might really put pressure on the
Mayor for effective actions. But what happens is that much of the air
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pollution in the Los Angeles area, for example, because of the prevailing
winds and the location of mountains--meteorology and topography--pockets
in Riverside and San Bernardino Counties. What can the county commission-
er in San Bernardino County do about the fact that it's all blowing into
his area from Los Angeles County, Orange County, and so on. The problem
also exists in the Phoenix metropolitan area, where the city of Phoenix
has done relatively little in the way of planning and decision making with
respect to photo-chemical oxidant control. The City of Scottsdale on I
the continguous boundary, with a population of about 90,000, has sponsored
effective land use planning for years, particularly because its a |
tourist center. The tourists come there for sunshine and clean air and
a view of the mountains. Scottsdale, similar to Riverside and San
Bernardino, is located to the north and east of Phoenix, and the pre- I
vailing winds are southwesterly. So the pollution blows into Scottsdale
from Phoenix. What do you do? How does the mayor of Scottsdale cope |
with this? If these decisions are left to the city of Phoenix alone,
how do you set parameters and constraints for Phoenix to begin to make
decisions that will protect Scottsdale? This is a serious issue. How
do you create an institutional structure that can cope with these
fragmented jurisdictional boundaries, that can cope with the complexi- Q
ties of metropolitan government and of air pollution that blows across
these boundaries?
In conceptualizing this problem, I've found it useful to think of I
a simple three by two matrix: down the left side, State, Regional, and
Local levels of government; across the top, General Purpose Government
units and Special Purpose Agencies. The first question to resolve is: _
"Where should the primary locus of authority or responsibility for
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relating air quality to land use lie--State level? Regional level?
Local level? A general purpose agency? (the governor? the county?
the mayor?) Or a special purpose agency? An air pollution control
district at a regional level? An air board at the state level?"
Once the decision about where the primary locus of responsibility
ought to reside has been made, one is then left with deciding how that
institution is to relate to all the others. For example, how will the
Bay Area Air Pollution Control District relate to the Association of
Bay Area Governments with respect to indirect source regulations? In
I preparing a parking management plan and an Air Quality Maintenance Plan,
how will the City of Los Angeles relate to the County of Los Angeles,
and to the Los Angeles Air Pollution Control District, and to the
Southern California Association of Governments, and to the air quality
task force for the six counties in the South Coast Air Basin? As we
move into this institutional issue more and more, these institutional
relationships must be determined. Our role as outsiders really is to
| encourage the responsible, politically accountable decision makers to
« themselves meet with their colleagues--the county commissioners with
the mayor, for example--and determine how their respective institutions
I are going to relate. I see this as an essential pre-requisite to making
the kinds of changes to the system that are critical if these air programs
| which relate to land use programs are going to be effective.
I Air Quality and Land Use Institutional Structures
I want finally to suggest a number of concepts that seem valid and
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important in terms of thinking through this issue of air quality/land
use institutional structures. First, we are focusing primarily on the
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preventitive rather than the curative mode. The prevent!tive mode deals I
solely with new growth, with new facilities. It requires a certain level
of technology to be placed on those facilities, such as New Source
Performance Standards. It requires review of new shopping centers to
insure that they do not produce terrible congestion that violates the "
standards, rather than an examination of all existing shopping centers flj
to change those which cause undue congestion. Even the preventive mode
of dealing with air quality and land use is politically explosive; but
imagine going backwards, to the whole universe of existing facilities.
The parking surcharge did exactly this, covering existing as well as new
facilities. I think it's critical to preclude further obvious violations
of air quality standards by doing a good job in the preventive mode, and
essentially let technology catch up on the curative side. That's the
focus I think we want to have.
Secondly, what we advocate clearly is not "no growth", but instead
"managed growth." We see a change from the traditional concept of: "I
own the land--I'll do anything I damn please with it--it's my land" to
a concept of "All right, what do you want to do with your land, let's
review it, let's discuss it--is it responsible in the Environmental Age?
Is it responsive to the new environmental ethic or not?" This is
managed growth, which requires planning as a pre-requisite to decision
making. Or, it might be termed "environmentally responsible new growth."
Another basic theme is that as many decisions as possible should be
made at the lowest levels of government, bringing higher only those with
externalities or regional impact. Decisions on smaller, localized |
projects should remain with the cities and counties, introducing new M
parameters for their decision making. Decisions on projects with major
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externalities must be brought up the line, through review and appeal
processes of various kinds.
Another major point is that we're concerned with emissions of air
pollutants, not with growth per se. We want new growth in this country
which is non-polluting, or minimally polluting, or polluting as little
as possible, rather than no growth. Because we're concerned with the
| relationship of growth to emissions, pollution abatement technology is
M a critical factor. As we get better technology on automobiles, or
smokestacks, more growth can ensue at the same level of environmental
quality or environmental degradation.
Another basic theme calls for general purpose units of government
| to be involved. Too often over the past 20 years the federal government
has relied on creation of special purpose districts to solve critical
problems. That may work as long as the primary focus is on technology,
but as you begin to get into issues related to land use, the politically
accountable officials must be involved: the County Commissioner who
stands for election, the Mayor, the Governor. These officials, of course,
_ will rely on their staff people to a great extent, but they must be
involved in these air quality/land use decisions. They must know what's
going on, and they must be committed early to full participation in
relevant decisions. All of us must take the time to insure that this
happens before we proceed to implement our programs.
For example, the air quality maintenance planning process is very
important, it's not the plan by itself that's important. How many of us
have seen zoning plans and beautiful 8-colored zoning maps on the wall,
that don't mean a thing? The omnipresent variances have altered the
plans every time a developer has come along with a little political
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leverage. So, it's not the Air Quality Maintenance Plan in which I'm
primarily interested, it's the air quality decision making process.
And when you're talking about a decision making process, you're talking I
about the mayor, and the city council; you're talking about the county
councillors; you're talking about the governor, and his political aides, |
and the State legislature, as well as the air pollution director. These _
politically accountable officials must be involved to relate the
technology of air pollution control to all the other things being done.
The air quality programs must be integrated with comprehensive planning
and zoning, with transportation planning, with sewerage decisions which |
relate to housing which relate to the use of automobiles. It sounds _
simple for an ecologist to admit that everything affects everything else. "
But although it's not simple, as you try to relate air quality to land fl
use, it really is true. The only officials who can make this integration
of goals, objectives and techniques are those who are at the apex of the I
pyramid at each level of government: the governor, county supervisors,
the mayor, the city council.
Lastly, to the degree possible, individual source by source decisions
should be made in an appropriately broader context. Thus we intend to
emphasize the areawide plan rather than the individual source-by-source
review, considering the plan part of the overall decision making process.
If possible, we should not review the individual shopping center alone
as an indirect source, but should consider it within the context of an
overall Air Quality Maintenance Plan. Because through the plan rather
than by the individual source-by-source review, you can sequence
development over time. You can make some trade-offs between this
shopping center making air quality a little worse, and additional
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M controls on other existing or new facilities. This allows creation of a
balance, and may allow approval of a shopping center which looked at all
by itself might have to be disapproved. Too many "no" decisions on
proposed facilities are going to place you, me, the mayor, and everybody
I else in trouble with the developer. We expect some controversy, but if
^ there is too much we will not be able to cope with it. So, we are
emphasizing parking management plans or parking resource plans rather
flj than individual parking lot reviews alone. The plan or the planning
process must incorporate source-by-source reviews as an integral component.
I But these reviews will be placed in a broader geographic and temporal
context.
Conclusion
In conclusion, EPA's air pollution abatement and control activities
are bringing the agency inexorably into the land use arena. This
involvement is essential for attainment and maintenance of national air
quality standards, and for preservation of clean air. A judicious
combination of pollution control technology and more responsible land
| use decision making in the Environmental Age provides the only effective,
g long-term solution to the challenge of air pollution. We are committed
to effective state and local implementation of these air quality
programs which influence patterns of land use, and are working closely
with the private development community and with state and local officials
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to ensure that this occurs.
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AIR QUALITY MANAGEMENT AND LAND USE REGULATION
_ Daniel R. Mandelker
The Clean Air Act and Land Use
| In approaching the structural framework that the Clean Air Act has
given us for dealing with land use problems we find two major sections
of the statute in which land use issues are treated. The first is in
those sections of the statute providing for state implementation plans.
Here the statute authorizes the inclusion of land use controls in state
I plans as may be necessary to achieve air quality standards. This
« provision in the statute is broadly stated, and can be read as an alterna-
tive to the more conventional pollution controls over technology and
I emissions. Just how this authority is to be used by the states is not
made clear, however. There are few clues in the statute's legislative
| history which can tell us how this power in the Clean Air Act is to be
a carried out; neither has there been much effort in practice to use
this authority in the implementation plans that have been prepared. EPA
has been proceeding in other directions and has been implementing other
sections of the statute dealing with land use controls. Yet the basic
I land use control power in the statute is in the implementation plan
section and the question now is how to make use of this power.
The second set of provisions in the statute that have a land use
control potential are the provisions dealing with stationary source
2
performance standards. These provisions require an authority at the
state level which, in addition to including the performance standards
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that are required by the law, also authorizes the review of new
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stationary sources to determine whether their construction or modification
at a proposed location will violate an air quality standard. Presumably
this power must also be applied to prevent the degradation of the air in
areas in which the quality of the air exceeds the statutory standards,
assuming that the nondegradation principle remains in the law. What is
novel in the execution of this provision is its present application to
indirect as well as direct sources of pollution. As presently inter-
preted by EPA, the new source performance standards have been extended
to indirect as well as direct sources, in order to control motor vehicle I
emissions that are attributable to the construction of these indirect
sources. They have been defined to include major shopping centers,
airports, highways, and other large-scale developments. These develop-
ments do not pollute directly, but contribute to pollution by attracting
automobile traffic that increases or adds to congestion and thus to the |
build-up of pollution from automobile exhausts. M
This extension of new source performance standards control to
indirect sources has not so far been found to be outside the authority
of the statute, although arguments have been made that EPA has no
authority under the law to extend new source performance standards J
review to cover indirect sources. While litigation to settle the »
question may be necessary, this extension of the act arguably appears
to be within the statutory terms. B
A third provision in the Clean Air Act does not relate directly to
land use control problems, but bears on these issues indirectly. While
plausibly simple in theory, this provision has proved to be considerably
more complex in practice. My reference here is to the provision of the
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law which states, with reference to the primary air quality standards,
that an extension for compliance with these standards may be granted by
EPA for periods up to two years, but only in cases in which the state
has considered all reasonably available alternative means of achieving
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these standards.' The problem here is whether the state in taking into
consideration these alternative methods of achieving the primary
standards must consider land use controls as one possibility. It happens
that the states that have asked for two-year extensions have not consider-
ed land use controls as one means of achieving the standards, either be-
cause this type of control has not been promoted aggressively enough by
EPA or because the exercise of land use controls has met social
resistance in some states.
Just how critical is the failure of the Clean Air Act to specify
_
* more explicitly the types of alternative methods that must be considered
I
is illustrated by a case just decided by the federal Court of Appeals in
4
the Second Circuit. In this case, New York State applied for and
received from EPA an approval of its decision to extend compliance with
the statutory air quality standards in Metropolitan New York City.
_
New York State had rejected land use controls as an alternative method
for achieving the standards , in part on the ground that these controls
would meet social resistance. The federal statute does not explicitly
cite social resistance as a reason for not using the land use control
approach. Nevertheless, the federal court upheld EPA's approval of the
New York extension, holding that it is within the agency's discretion to
decide whether or not all reasonably alternative means had been considered,
and that the agency does not have to meet an unreasonable burden by
finding that all alternatives that might have been used have been
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considered and rejected. The court also agreed with New York State on _
the issue of social resistance, holding that some of the proposed
alternative land use controls, such as the elimination of all steam
plants from New York City, would require too long a time to execute to
contribute to compliance with the statutory air quality goal.
This case raises several complex issues in the administration of
the Clean Air Act, especially as the air quality goals specified by the
statute relate to the types of land use controls that can be helpful in
meeting these goals, and to the time frame within which these controls
can realistically be helpful. Hopefully EPA will respond to this I
problem, first by specifying more explicitly the kinds of land use
controls that can be helpful in achieving the desired air quality, and
next by indicating what time periods should be considered in the execu-
tion of these controls. EPA's authority to grant extensions of time
for statutory compliance should then be geared to these directions.
Perhaps additional Congressional direction will also be needed on this
problem. I
Complex and Indirect Source Review
Let us turn next to issues of a more specific nature. One of these
is the question of complex source review, or what is now known as the
review of indirect in contrast to direct pollution sources. This review,
as indicated above, considers those sources which do not contribute
directly to pollution but which aggravate pollution by attracting
additional automobile traffic and increasing traffic congestion. These
indirect sources have been divided into publicly built and privately
built facilities. Indirect source review of public facilities presents
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M some special problems. Many of these public facilities, in addition to
being subject to indirect source review under the air quality program,
I are also subject to massive statutory controls and review under other
federal statutes, as is the case with airport and major highway
construction. For example, the federal-aid highway statute contains a
_ wide variety of environmental requirements that must be met in the
* construction of federally-aided highway projects, including noise
I standards. Compliance with air quality standards is also required.
Federal agencies having direct responsibility for the funding of these
major public facilities also exercise considerable power and exert
_ considerable influence on this own, and this power and influence affects
the character of programs such as airport and highway construction.
From this wider perspective, the problem is that indirect source
review under the Clean Air Act has been approached solely from the
perspective of air quality standards. Unfortunately, this approach does
not consider important factors such as the effect that indirect source
review will have on patterns of land development. In addition, federal
agencies having a direct responsibility for public facility programs
will not so easily be eased from their positions of responsibility.
Direct inter-agency coordination and consultation will probably be
needed to work out the complex issues that the application of air
quality standards to public facility projects raises, and paper edicts
from the Federal Register will not in the long run be enough to resolve
these problems.
As far as private indirect sources are concerned, the EPA's author-
ity in this area has been extended to major residential developments as
well as to nonresidential uses, the indirect source regulations seem to
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be relying on two kinds of controls to achieve their objectives. The
first of these is design requirements including modifications in the
design of parking facilities, which are intended to alleviate major I
congestion problems. The second set of controls lie in the conditions
that may be attached to approval for indirect sources. These conditions, |
to take one example, may include assurances that the operator of the mm
indirect source will supply his employees with incentives to use mass
transit facilities. We shall see later that this kind of condition I
creates some serious problems of implementation in the context of the
Clean Air Act and its state counterparts. |
We should also note that the extension of time provisions for _
compliance with air quality standards do not apply to indirect source
review. Review of indirect sources is based on the new source perfor- I
mance standards section of the act, which is mandatory for all state
air quality agencies, making indirect source review likewise mandatory.
As a consequence, states may not excuse themselves from utilizing indirect _
source controls on the basis of social resistance, an argument which EPA
apparently is authorized to accept with reference to other types of land
use controls that may be utilized as part of the state's implementation
plan. I
This mandatory character of indirect source review forces us to look
closely at its implications for urban growth and land development patterns.
EPA's indirect source review regulations require a source turndown if
interference with the achievement of air quality standards will result.
But conditions may be attached to the approval of indirect sources which
include elements such as modifications in design features in order to
prevent or minimize the impact of the source on the achievement of
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_ quality goals. This emphasis on design considerations may cloud the real
impact of indirect source review, which is its consequences for major
land development patterns. For example, EPA has used a threshold
quantitative cutoff point to identify those sources that are subject to
indirect source approval. If developers then attempt to evade review by
building under the threshold figure, scattered, strip, and dispersed
development may result which is inconsistent with area-wide land develop-
ment objectives. More explicit attention needs to be given to the
locational impact of decisions over indirect sources that are taken in
the name of air quality, and design factors should enter later. Again,
as in the case of public facilities, indirect review of private sources
raises complex and interconnected planning and land development problems
which need to be answered from more than just the air quality perspective.
From what has been said, and considering in particular the role
that other public agencies will play and the major effects that location
decisions will have on urban development patterns, it may be expected
| that the administration of indirect source review may often be politically
« maneuvered. Moreover, the major decisions applicable to indirect source
construction will probably have to be taken at least on a regional scale.
An example of both of these possibilities occurred during the preparation
of a strategy plan for the city of Melbourne, Australia.
I Melbourne is one of the few modern cities in the western world which
_ has an active, growing, and dominant central business district. More than
85 per cent of the workers who come into this district still arrive on
I public transportation. As the work on the strategy plan proceeded it
became clear that there were heavy pressures on foot in the area to create
I a secondary central business district at a point some distance from the
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primary CBD. This secondary CBD would not be nearly as well served by _
the public transportation network as the primary CBD. Planners working
on the strategy plan suggested that to approve the secondary CBD would I
encourage the further suburban spread of shopping areas. By destroying
the dominance of the primary CBD with its dependence on the public
transportation network, a secondary CBD would also increase motor
vehicle use and thus the air pollution that goes with it. For this and
other reasons the proposals for a secondary CBD have now been shelved.
Essentially, this decision was taken by the political leadership in the
state in which Melbourne is located. They have more control of the I
policy decisions that back up the planning process than do their
American counterparts.
But the Melbourne example also illustrates the need for a regional
perspective on land development decisions that have an air quality impact.
Melbourne planners are in general more sensitive to the need for a major I
structural framework within which land development and its attendant air
quality impacts can be considered. Decisions about proposed secondary M
business districts clearly affect this overall developmental structure,
and such decisions must be made with the regional consequences in mind.
A comparable regional framework is absent from EPA's indirect source
review, though presumably it can be supplied by the state agencies that
are initially authorized to administer the indirect source regulations. I
There is, however, no statutory mention of a regional input into the
administration of the new source review provisions on which indirect
source review is based.
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Local and Regional Roles Within the Framework
of the Clean Air Act
I The Clean Air Act is similarly silent on state-regional and on
state-local rules in the administration of the act, which must be
spelled out if statewide policies are to be effectively translated both
_ at regional and local levels. EPA has authorized the delegation of
B administrative authority by the states to local governments, but has not
specified how state or regional policies in programs such as indirect
source review will be monitored or enforced. More attention needs to be
given to this problem as well.
The need to provide more clearly for a local and regional role in
indirect source review is illustrated by some of the conditions that EPA
m authorizes for inclusion in indirect source approvals. Recall that one
of these conditions requires the developers of indirect sources, such as
shopping centers, to provide assurances that their employees will utilize
mass transit facilities. The question is how this condition can be
enforced. First, this condition cannot be enforced within the traditional
land development control framework, and secondly, the regulations do not
state how this condition is to be made effective within the intergovern-
mental framework. In particular, neither the states nor their local
governments to which indirect source review may be delegated have any
| control over mass transit operations, which are usually confided to inde-
pendent public authorities. What is needed is a framework for regional
decision making of the kind that was possible in the Melbourne area, and
travel.
fl that will help ensure that mass transit will be the preferred mode of
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Another approach to this problem is provided in the Model Land
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Development Code which is about to be adopted by the American Law
Institute. This code provides for state-level review of local govern-
ment decisions on the siting of major public facilities, such as
transportation facilities, but only when the local government decision |
is unfavorable. The Institute's code thus provides for a review of _
siting decisions on the transportation facility network, at which point a
more effective control may be exercised over the provision of mass transit I
opportunities. There is no explicit tie to air quality control in this
code, however, and its failure to provide for review of local government |
approvals as well as disapprovals may limit the effectiveness of the _
state-level review that is authorized. But the Code does deal with the
intergovernmental decision making structure within which these decisions
are made by specifying clearly the supervisory role of the state reviewing
agency and by providing standards for this state-level authority. I
NEPA and CEQA
Let us look next at the impact of the federal National Environmental
Policy Act on air quality problems, as well as the impact of its state |
counterparts, such as the California Environmental Quality Act. Under ^
federal guidelines for the implementation of NEPA it is clear that
approvals of indirect sources will also require the preparation of an I
environmental impact statement, and the California law will also be
applicable, both to public and to private developments. Moreover, the |
impact statement prepared under NEPA-like acts requires more than the _
consideration of air quality, since it must extend to all significant
impacts on the human environment. This impact may include the impact
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of the proposed development on urban and growth patterns. For example,
7
a Federal District Court case in Vermont held recently that one of the
impacts to be considered in an environmental impact statement for a state
highway was the growth-incuding effect of that highway. California's law
also includes growth-inducing effects explicitly as one of the impact to
be considered in statements to be prepared under the California statute.
The application of the impact statement requirement to indirect
M sources may not be too troublesome if the statement is considered only
as an informational document and does not have any substantive implica-
I tions. But it is not clear that this is so. Some federal courts have
held that NEPA provides "law to apply", and have held that a reviewing
| court may reject a project on its merits on the basis of adverse
« environmental effects disclosed by an impact statement. There is a
possibility that the California statute will be interpreted in the same
I manner. To the extent that the NEPA-like statutes impose on additional
environmental and substantive review, these statutes must be considered
| along with the Clean Air Act as providing substantive policy for the review
_ of indirect sources.
The addition of a new substantive element by way of the impact
statement will also produce additional confusions because in most states
and at the federal level there is no institutionalized administrative
process in which the statement can be considered and a formal decision
on its adequacy taken. As a result, the ultimate control over the ade-
quacy of impact statements lies with the courts. Any party having
standing to sue may challenge the adequacy of an impact statement in
the courts, and the federal courts have so far given standing a liberal
interpretation. As a result, decisions taken about indirect sources
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under EPA regulations may also be brought into court for additional review «
by way of the impact statement requirement.
I view this result as unfortunate, for it presents some real
problems of coordination between the indirect source review procedures
and the federal and state environmental policy acts. EPA's regulations, pj
of course, do provide that impact statements must be looked at for - _
information relevant to the indirect source review. I think this
approach is correct, but it is not enough. More coordination will be I
necessary. We simply have too much environmental law floating around,
and we haven't hooked it all up.
Conclusion
I
In summary, the intrusion of air quality controls in the land use
methods of regulation. Most of the techniques which are contemplated m
are already available. What is needed are new institutional arrangements
to better carry out these programs. Since the major problems arise from
the legal fragmentation of environmental legislation in fields other than
air quality control, there is a need for better and increased governmental |
coordination, to the increased use of well-established regional agencies «
for the largely insular regions like those in California, or to a *
delegation of approving authority to local governments, subject to very
specific substantive criteria in the statutes, which will in turn provide
the basis for a higher-level review. J
These air quality land use requirements and their implementation
will also lead to trial and error experiments. But if we aim especially
at achieving and maintaining air quality goals in the long run and over
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an extended time framework, we will be able to develop a better re-
structuring of governmental land use mechanisms in which air quality
control can play a leading part.
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REFERENCES CITED
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1. 42 U.S.C. §1857c-5(a)(2)(B) (1970). For further discussion o£ land
use issues in air pollution control see Mandelker § Rothschild, The Role
of Land-Use Controls in Combating Air Pollution Under the Clean Air Act
of 1970, 3 Ecology L.Q. 235 (1973).
2. 42 U.S.C. §1857c-5(a)(4) (1970). I
3. 42 U.S.C. §1875c-5(e)(l)(B) (1970).
4. Natural Resources Defense Council v. EPA, 494 F.2d 519 (2nd Cir.
1974). I
5. See the statutory provisions beginning with 23 U.S.C.A. 109(h)
(Supp. 1973). I
6. 40 C.F.R. §§52.22(b)(4)(ii); 52.22(b) (9) (ii) (1974). _
7. Conservation Society of Southern Vermont, Inc. v. Secretary of
Transportation, 362 F.S. 627 (D. Vt. 1973).
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m INSTITUTIONAL ISSUES IN AIR QUALITY MANAGEMENT
George Hagevik
The papers by David Morell and Daniel Mandelker provide an excellent
| setting for the subsequent discussion of specific techniques for air
m quality impact analysis. Before making the transition from the general
to the specific, however, it is necessary to examine further a number of
I the issues raised by both Morell and Mandelker. The thrust of the
following comments relates primarily to the question of institutional
Jj mechanisms for implementing the Air Quality Act.
I Basic Questions
The question that we must ask ourselves is, in the final analysis,
what is the purpose of all of EPA's air quality regulations and the
actual air quality impact analysis that we are carrying out? Judging
by the comments that I have heard at public hearings over the last
year there is considerable confusion about the answer to this seemingly
straightforward question. I place part of the blame for this development
| on EPA because, quite frankly, I feel that they have not had a clear idea
« in their own minds of the purpose of their various air quality management
regulations. This criticism needs to be tempered by the realization
that the EPA staff has had a very difficult time responding to legislative
and court-ordered mandates with exceedingly limited personnel. But in
| any case, the fact remains that confusion has indeed been fostered in
part by the Federal government. Only quite recently have we seen
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relatively clear and straightforward statements from EPA concerning the
role of their various air quality management relations.
This problem seems to be more or less behind us now judging by what
I have read lately in the Federal Register and in various EPA documents.
Probably the more important criticism now must be laid at the feet of
planners and air pollution personnel in state and local government and
representatives of various environmental groups. The creative solutions I
to problems that David Morell would like to see arising from state and ft
local government are more the exception than the rule. To my mind it is
now clearly the time for this creative initiative to take place. EPA
has finally wholeheartedly embraced the concept that air quality
management is really an inter-governmental relations problem and that
every level of government has a distinct role to play. For better or <*
worse, the burden of responsibility really lies at the present time with
the planners and air pollution control personnel at the state, regional, I
and local level.
I am afraid that this conclusion is not readily accepted by many |
environmental groups, who view the court suit as their primary means of w
having an impact on the air quality management process. This procedure
has been very productive in encouraging EPA to play closer attention to I
the mandate specifically written into the Air Quality Act but the
litigation approach now must be complemented by a broader based effort |
by the environmentalists to work with state and local officials whom ^
they have, by and large, ignored to date.
Because I am somewhat of an optimist by nature, let us assume that
these criticisms are really only of historical interest. There is thus
one remaining problem that we need to deal with: attempts to use air
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quality regulations for purposes for which they were not designed. In
much the same manner that the environmental impact statement process is
tt sometimes used to delay or defeat projects which might be opposed on
other than environmental grounds, air quality regulations are sometimes
viewed as a general technique for achieving further governmental control
over the land use development decision process. As a planner, I support
a strengthened role of government in land use planning, but I think we
must resist efforts to use air quality regulations as a means to achieve
comprehensive planning goals. Air quality regulations are also sometimes
used like the environmental impact statement process whereby projects or
plans are delayed or defeated by individuals or groups who oppose projects
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on environmental grounds while the real basis for their resistance might
be of a social or economic nature.
m Air Quality Maintenance
' It is useful for land use and transportation planners to view air
quality regulations as primarily relating to the maintenance of acceptable
levels of air quality over the long term. Ignoring for the moment air
pollution problems that are of a localized or short term nature, the
long term perspective provides us with a useful insight into what infor-
B mation land use and transportation planners need from any air quality
impact analysis. What we are talking about here is air quality mainte-
nance. A-recent preliminary draft paper by EPA entitled "Uncle Sam as
Pollution Regulator," puts air quality maintenance in a proper perspective.
Referring to EPA's air quality maintenance regulations, the paper states:
"In June of 1975, states must submit 10 year growth plans
covering any area whose attainment or maintenance of the
I national ambient air quality standards is in doubt; these
plans must show how the area will maintain the standards
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through control of design, and placement of all new
sources of air pollution. Air quality maintenance |
areas will be designated by the states, and will
include not only currently polluted areas, but also ^
areas whose present or anticipated growth and develop-
ment patterns, left unchecked, could lead to future
standards violations. The growth plans prepared for
these areas will be just that, land use and growth V
plans consciously tied to air quality considerations. I
They offer a formal mechanism for state and local
governments to make long term reconciliations between
air quality and other social and economic goals."
The issues can scarcely be stated more succinctly than they are in _
this brief paragraph. It is essential, I believe, to understand the air
quality maintenance process if one is to play an active role in a Federal
environmental program that will have a pervasive influence on state and
local governments. I
The Air Quality Maintenance Process
To date, EPA's air pollution programs have utilized the State
Implementation Plan (SIP) as the technique for attacking existing air |
pollution problems in specific geographical locations. Because of _
continued urban growth not only these areas but additional geographical *
areas with air quality better than the national air quality standards l|
will now have to cope with long range planning. Recognizing the effects
of future urban growth of air quality, EPA in 1973 expanded the SIP £
requirements designed to guarantee attainment of national air quality _
standards. The maintenance regulations request that all states identify
those areas within their boundaries where there is a possibility that
air quality standards will be exceeded during the 1975-1985 period,
either because of existing air quality problems or because of the I
potential for degraded air quality due to new urban growth. These areas,
1
to be designated as Air Quality Maintenance Areas (AQMA.), are to be
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covered by an air quality maintenance plan which EPA hopes will be a
comprehensive analysis of the air quality problem and contain regulatory
measures on air pollutant emissions, including land use and transportation
controls, as may be necessary to prevent a violation of the national air
| quality standards.
It is important to note that it is EPA's position that the air
quality maintenance plan will integrate all air quality regulations
including indirect source reviews, transportation control plans and
stationary source controls. Quite clearly the air quality maintenance
| plan effort must be integrated with land use and transportation planning
« to insure a consistent approach with comprehensive planning efforts and
to provide a mechanism for recognizing potential environmental problems
ftj early on. The development and implementation of this plan will require
complicated intergovernmental relationships. State, regional, and
| local single and multi-purpose governmental agencies will all have to be
_ involved. It is EPA's position that whatever specific agency is assigned
responsibility for air quality maintenance as a "lead agency," coordina-
tion with all other relevant agencies will be essential to produce
effective regulatory programs.
The air quality maintenance plan at the State and area-wide level
will form the basis upon which to evaluate all new sources of air pollu-
tion. We see here the necessary relation between local plan and project
review and the larger air quality maintenance planning process. EPA
thus argues that the air quality maintenance planning process will assist
I communities in managing future growth by effectively integrating air
quality constraints into planning and decision making processes at all
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levels of government. Air quality maintenance will serve to define air
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performance standards to fuel conversions to transportation control
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quality constraints within which localities can grow while still main-
taining national air quality standards. For this reason it is mandatory
that the general public have an understanding of the various regulatory
measures which are part of the air quality maintenance plan and support
their implementation as a part of overall community goals. Similarly, |
the various land use, transportation, and air pollution agencies must m
start working with each other in order to guarantee that all plans are
consistent with the maintenance plan. I
It is EPA's position that a framework for the necessary inter-
governmental relations in a particular area will depend upon the institu- ]|
tional frameworks existing in that state or region as well as the tradi-
tional relations between the states and localities in the United States
with the qualification that, regardless of the particular framework £
selected, the planning process must involve participation by those who
will have ultimate authority for implementation and enforcement of the
plan. One might accuse EPA of passing the buck to the States and
localities on air quality maintenance since the set of intergovernmental B
relations that will be necessary will have to be developed by the partici-
pants. It seems that after being "burned" on the initial go-around with
the transportation control strategies, EPA has realized that they cannot I
carry the major responsibility in air quality management. After some
reflection I would think you would agree that their position is a very
reasonable one. In any case EPA will provide technical support to the
respective states and localities. For example, in one recent EPA report
nineteen different measures which could be useful in maintaining air
quality standards are reviewed. These measures range from new source
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strategies as well as some more general approaches related to land use
planning. One approach which seems to have considerable potential is
emission allocation planning.
^mission Allocation Planning
Emission allocation is a maintenance strategy which requires that
I emissions of pollutants be limited to prescribed levels within an airshed.
On the regional (airshed) level a relationship is established between
the assimilative capacity of the ambient air in the region and the amount
m of emissions within the region which would not violate air quality
standards. The emission allocation procedure would be administered joint-
ly by air pollution control agencies and land use planning agencies.
The procedure may be applied to all pollutants and to both existing
and new point, line, and area sources. Although related to emission
density zoning, emission allocation should be viewed as a much more
generalized technique concerned with regional air pollution problems that
I has a focus on the comprehensive land use plan as the basic document
2
from which future levels of air quality are estimated.
The purpose of emission allocation is to utilize land use based
emission factors to evaluate the air pollution potential of comprehensive
land use plans within a defined region. The land use plans therefore need
to be viewed as an accurate representation of the future development that
can be expected in the region under study and thus assume a position of
importance in estimating future levels of air quality.
The concept of emission allocation procedures is that there should
be some relationship established between total air pollutant emissions in
a region and the assimilative capacity of the ambient air in the region,
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and that this relationship should be projected into the future to estab-
lish the total amount of emissions that can be allowed at some future
point in time. The assumption is made that there is a fairly close I
relationship between urban growth and increasing levels of air
pollution. Thus, if we had a picture of the future levels of land I
development in a region, one could select the type of air quality
maintenance strategies that would be necessary to insure that air
quality standards will not be violated. The comprehensive land use plan I
provides this picture of future development. Thus, emission allocation
planning is both an air quality management and land use planning technique. |
The recognition of the importance of land use planning as a «
technique for maintaining air quality standards led the California
Legislature in 1972 to direct the California Air Resources Board (ARE)
to prepare a report on proposed guidelines for the preparation of an air
pollution control element in city and county general plans. In response |
to this mandate, the ARE let a contract to the consulting firm of «
Livingston and Blayney to prepare such a report in cooperation with the
ARE staff. However, as the study progressed in early 1973, it became I
apparent that air quality management can be effectively integrated with
land use and transportation planning only on an air basin-wide basis. f
Accordingly, the procedures which the consultant recommended would vest _
responsibility for allocating air pollutant emission limits within each
air basin in the State in a regional agency.
Six steps were proposed in the consultant's report to integrate air
quality goals into the land use and transportation planning process under I
the emission allocation procedures:
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1) Compile detailed inventories of air pollution emissions
in planning sub-areas of an air basin. The assumption
is made that present inventories for counties and the
air basin are too generalized for detailed air quality
planning.
2) Designate maximum emissions allowable in each planning
sub-area to achieve and maintain air quality standards,
based on an analysis of present air quality and the
assimilative capacity of the air to absorb pollutants
and still maintain air quality standards.
3) Project planning sub-area emissions likely to be
generated by sources indicated in land use and
transportation plans for designated future time
periods and compare these emissions with the allowable
emission limits.
4) Evaluate and revise land use and transportation plans
so that prescribed emissions limits would not be exceeded.
5) Adopt and implement land use and transportation plans which
are prepared to meet air quality goals and standards.
6) Monitor public and private development through a refined
environmental impact assessment process in which emissions
projected directly or indirectly from proposed are
accounted for in environmental impact reports.
The key to this process is the concept of allocating air pollutant
emissions within an air basin. As long as plans and projects conform to
prescribed emission limits air quality standards will be maintained. An
appeal process would permit deviation from prescribed limits where
technical information is available to ensure that air quality standards
will not be exceeded by the proposed deviation.
The designated regional agency in the air basin would compile the
planning sub-area emissions inventory and then designate the emissions
limits for each planning sub-area. City and county planning agencies
would make emissions projections based on their land use and transporta-
tion plans, using emission factors provided by the Air Resources Board
and the Environmental Protection Agency, and then adjust their plans to
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meet prescribed emission limits. Transportation planning agencies like- w
wise would make projections of the emissions that would be generated by
their proposed plans, and revise them accordingly. A significant amount
of interactions between the agencies involved would be necessary before
all plans throughout an air basin met the prescribed emissions limits. |
Appeals to exceed emissions limits would be decided by the designated .
regional agency. Once the plans had been approved by this agency, the
responsibility for implementing them would rest with the cities and I
counties. However, the designated regional agency would continue to
monitor development through the environmental impact assessment process |
to ensure that emission limits would not be violated. _
This general approach to air quality maintenance has a great deal
of logic but there are problems with it. Among the many issues which
could be raised, I would like to discuss two: (1) the impact of an
emission allocation planning strategy on land use and transportation
planning, and (2) administrative arrangements. By placing a ceiling
on the total amount of air pollutant emissions in a region, while
leaving the determination of how to maintain this lid to the appropriate
planning and air pollution control agencies, obvious trade-offs between
alternatives become possible. For example, hydrocarbons, along with
oxides of nitrogen and sunlight, form the basis of photochemical
oxidants. An appropriate governmental agency might control hydrocarbons, I
and maintain emissions within the specified ceiling, by either of two m
strategies. Either the automobile, which emits significant quantities of
hydrocarbons, would be controlled, or hydrocarbon producing stationary I
sources such as petrochemical complexes, would be restricted.
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Clearly the number of potential alternative approaches which could
meet emission ceilings for a set of pollutants is very large. The number
of reasonably feasible alternatives, however, is much smaller. For
example, while vehicle miles could be cut back to some degree in a
metropolitan area, massive shifts in automobile use, while desirable,
would be difficult to implement. While the emissions from industrial
sources can be controlled at the stack through performance standards,
the aggregate effects of many installations clustering in one locality
may mean that emissions are excessive. In turn, this may mean that there
is relatively little that can be done to permit new polluting industries
if emissions are near the specified ceiling for the planning area. It
should be clear, therefore, that an effective implementation of emission
allocation planning would involve some very tough political decisions.
There is no question that the actual implementation of such a
procedure could only take place if a number of conditions are met.
These include:
1) The availability of a current emissions inventory and land use
data. This land use data would be for current land use and for
expected future development.
2) The availability of sufficient resources to develop the
emission rates and to administer the regulations related
to air quality maintenance over time.
3) The availability of sufficient monitoring data to either
calculate the emission ceiling of the proportional model
or calibrate the dispersion model.
4) A well-developed land use planning capability on the part
of municipal and county government.
5) A well-developed procedure for relating project review
decisions to land use and transportation plans and the air
quality maintenance plan.
A number of other pre-conditions could be listed but I think you
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have a fair idea of some of the problems that must be addressed before
we have an adequate air quality maintenance planning process in operation.
The administrative arrangements for implementing emission allocation
planning is a topic that is bound to elicit strong reactions from indivi-
duals depending on what type of governmental agency or jurisdiction they I
represent. For example, municipalities and counties, allocated emission
levels by a regional agency, may feel that local autonomy has been
diminished. Recalling that total regional emissions are initially deter-
mined and then allocated to sub-areas, such as counties and municipalities,
an appropriate regional agency must be chosen to make this allocation. |
In California, the debate centers on whether this agency should be a «
council of governments (COG), an air pollution control district, or a
basin-wide air pollution control coordinating council composed of the
air pollution control districts within a given air basin. A second
administrative problem centers on the exact determination of the airshed. |
Generally, an airshed encompasses a geographic area which is meaningful »
from the perspective of pollutants generated and dispersed as a function
of meteorology. This airshed concept is not usually coterminous with 8
political boundaries. However, air quality maintenance areas (AQMAs)
to be designated by the States and EPA will be coterminous with the J
boundaries of municipalities, counties, standard metropolitan _
statistical areas, and the like. Consider the difficulties of defining
the amount of "background" air pollution drifting into an airshed when
the decision is being made to relate emissions to ambient air quality
concentrations within the airshed.
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Air Quality Analysis at the Project Level
In the papers that follow, there is considerable discussion of the
localized air quality impact of projects. We know a great deal more
about how stable pollutants behave in the vicinity of the emission source
| than we do about the behavior of the reactive pollutants on the regional
_ scale. Even though the information which follows is exceedingly useful,
it needs to be pointed out that the major air pollution problem we face
in California is with the reactive pollutants. Procedures for relating
emissions to ambient air concentration when photochemical reaction takes
place is very complicated and, unfortunately, cannot be given extended
discussion in this workshop. Hopefully we do have the building blocks at
' hand which will allow us to approach the more complicated long-term
issues with the proper perspective. Defining your own personal role in
air quality management should be something that you should keep in the
back of your mind as you read the following papers.
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REFERENCES CITED
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1. Guidelines for Air Quality Maintenance, Planning and Analysis, M
Vol. 3: Control Strategies, July 1974. Office of Air and Waste *
Management, EPA, Research Triangle Park, North Carolina. I
2. For a more detailed discussion, see: George Hagevik, Daniel Mandelker,
and Richard Brail, Air Quality Management and Land Use Planning. New J
York: Praeger, 1974. ^
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I AIR QUALITY CONSIDERATIONS AND
LOCAL LAND USE PLANNING
Ralph A. Mead
While decisions made at state and national levels are of great
importance for the growth and development of our urban areas, most land
use and transportation decisions are still made at the local level.
Cities and counties have a major role to play in relating long-range
mm planning to air quality, a role largely neglected to date by local
planners, in part due to the "top-down" approach taken by EPA and
I acquiesced to by others. The first part of this paper will focus on
local planning policies, while the second part will consider Land Use
I Planning Methodology. Local planning for improved air quality will be
_ considered under three broad categories: growth policies, land use
policies and transportation policies.
Growth Policies
Some local governments have no-growth or limited growth policies,
some are avowedly expansionist, and many have no explicit aims. Clearly,
I however, local growth is rapidly coming into the public arena for
discussion and policy-making, and bears a close relation to air quality.
| In most communities (and certainly in California) the primary
source of air pollution is the automobile. Since virtually all develop-
ment generates traffic, the automobile is the vital link between growth
policy and air quality. The main emissions associated with auto traffic,
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for the foreseeable future, are carbon monoxide, reactive hydrocarbons,
nitrogen oxides and (perhaps temporarily] lead; secondary pollutants are
photochemical oxidant (smog) and nitrogen dioxide. Of these, carbon |
monoxide and photochemical oxidant are of greatest concern to local _
planners--the former very localized in its impact and the latter *
affecting an area measured in miles and sometimes tens of miles. I
It has been suggested that the total amount of a given pollutant
permitted in a community should be limited, the "holding capacity" £
approach, or stated simply, putting a lid on emissions. This would set
an upper limit on growth, barring an unexpected breakthrough in source *
technology. Such a policy would have greater relevance to oxidant than
to carbon monoxide, for which a finer-grained control system would be
required. For a relatively large and isolated jurisdiction, an oxidant
lid (in practice a lid on reactive hydrocarbon emissions) is conceivable.
For most cities however, atmospheric transport, lack of control over
major highways and technical difficulties in long-range projection make
this policy unrealistic. A regional approach has been suggested, but
this raises extremely tough technical, institutional, and political
problems.
A more promising and widely applicable concept for local planners
to consider is linking air quality to the rate of growth, rather than
the total amount. This would require the application of time-specific
projections based largely on expectations about legally-mandated
automobile exhaust controls. The planner would have to know, for example,
what emissions and air quality to expect in 1977, 1980, and 1985 for a
given growth rate as new, cleaner autos gradually replace older, dirtier
ones. While the aforementioned difficulties associated with a "holding
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capacity" approach would still exist, the short and mid-range time frame
would reduce the uncertainties of projection and also enable the local
planner to take most or all of the highway network as a given.
Any local growth policy in which air quality is a factor must con-
8 sider regional and local meteorology and topography. If possible,
M atmospheric dispersion models now available and becoming available should
be employed; in this event, outside expert assistance will usually be
necessary. Where cost or other considerations preclude an extensive
modeling program, simple models may be used, including the advice and
I guidance of a knowledgeable meteorologist or air quality expert.
. Judgments about meteorological considerations can be valuable even
though non-quantitative in nature. Obviously, a numerical growth limita-
I tion cannot be based solely on non-quantitative studies. Unless the
meteorology is simple and the land is flat, extreme caution must be
| exercised in accepting statements about the "pollution potential" of an
_ area, much less basing growth controls on such statements; this is true
" for all pollutants, but particularly where oxidant is concerned. An
I experienced specialist is needed to make judgments inter-relating
meteorology, topography and air quality and frequently, even a specialist
cannot do so in the absence of adequate data or without undertaking a
detailed study.
Assuming that growth policies are decided on, how are they to be
implemented at the local level? Zoning and other land use controls are
universally available to local governments; their capabilities and
weaknesses are well known. A less common approach involves limiting the
timing, location and extent of growth-inducing or growth-enabling public
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works: highways, sewerage and water facilities. Sometimes these
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facilities are subject to local control; sometimes they are not. Where a
local control does exist, it might be used as a mechanism to implement a *
growth policy based entirely or partially on air quality. It is inter- I
esting to note that the lack of highways, sewers or water has been used
in some communities as a reason for limiting growth; here, on the other I
hand, the provision of these facilities is seen as a tool for implementing
a growth policy based on other considerations.
A word about New Towns and growth: however desirable they may be
for a variety of reasons, a New Town will not serve the cause of air
quality in the absence of an effective growth policy in the jurisdiction
where the New Town lies. Given the current opposition in many areas to
extensive growth, some New Towns are being packaged and sold as an
alternative to sprawl and as a means of limiting growth. But approval of
a New Town does not per se assure that growth will be limited--it is
entirely possible that the opposite will in fact take place, with the
New Town being used as a device to promote growth in the face of public
resistance. In those areas large enough to contain a New Town, the
proposal of such a development should be reason for intensive considera-
tion of the area's attitude towards growth.
Land Use Policies
careful and informed attention to air quality than local governments and
planners have so far exercised.
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Except in a very few totally built-up or exclusive communities, some
degree of development is bound to occur and land use decisions must be
made. Although land use policies will rarely be based on air quality
considerations alone, the formation of such policies require a more
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Generally speaking, land uses are related to future air quality by
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virtue of the automobile. Therefore, local planners need to have some
familiarity with traffic generation factors, modal split and trip length
frequencies--the tools of transportation planning and traffic analysis.
This means that any local planning agency seriously concerned about air
quality should have transportation and traffic expertise on its staff or
readily available.
Another way to look at land uses is as receptors of pollution, rather
than sources. It is possible to make quantitative estimates (for various
pollutants) in terms of pollutant exposure units per person in a land use
m configuration, e.g., the number of parts per million of oxidant, measured
during a given time period, times the number of persons exposed to that
I level of pollution in a particular geographical area. This kind of
"exposure index" could be useful in comparing land use alternatives; its
I application awaits the initiative of local planners.
Land use policies inevitably involve density, and we need more hard
thinking about density in an air quality context. There are times when
an informed judgment can be made about the density level that will
minimize future air pollution, but such judgments cannot be made in the
| abstract. Judgments can be made only in relation to a specific area, with
« knowledge of its development patterns and pressures. There is no reason
to believe that high density is always better than low density because
I concentrated development is conducive to mass transit. In the abstract,
there is equally good reason to speculate that a low density pattern
| would in fact minimize air pollution from automobiles. Before venturing
a judgment in a particular situation planners should consider such
questions as:
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1) Will high-density development in one area be "balanced" _
by non-development somewhere else, or will it tend to I
induce a higher density overall in the community?
2) Will high-density development produce a localized air
pollution problem? I
3) Will high-density development in fact be accompanied
by mass transit? I
4) Who is going to play for the mass transit and when will
it be available?
5) Will the number of trips diverted to transit exceed the
additional automobile trips produced by the higher density
of development?
Most importantly, density and land use in general must be viewed in M
terms of locational relationships. By reducing auto trip generation
and/or trip length, high-density housing located near a transit station I
may make sense from an air quality standpoint. We can assume that a
sports stadium should have ready access to a transit station. And we |
can recommend that a large residential area should have neighborhood
services located within it (which argues against exclusive residential
zoning for large areas). I
On the other hand, high-density housing located near an employment
center may not benefit air quality, nor is a regional shopping center's |
location on a transit line certain to do so. We should not be too quick
to jump from the motherhood statement that "Housing should be located *
near places of employment" to the conclusion that planning a high-density
housing zone in City X adjacent to the industrial center will improve air
quality (quite apart from whether or not the industrial center contains
large point sources of air pollution). The British New Towns experience
may be relevant here--people don't always work where the planners say
they should work.
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Redevelopment is a special kind of land use planning aimed at re-
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building the core of the older city. By and large, the revitalization of
central cities is desirable from an air quality standpoint, because
many redevelopment areas are centrally located with respect to existing
public transit routes and existing urban centers have high-density,
frequently congested patterns which tend to support mass transit as well
as discourage high auto ownership. Nevertheless, uncritical acceptance
I of redevelopment plans overlooks the possibility of localized air pollu-
tion problems, and the "halo" generally given to redevelopment by its
laudable social purposes is insufficient reason to ignore such problems.
Where a redevelopment area provides housing, there should be particular
concern about the localized air pollution impact on the future residents.
Among the local land use planning questions arising in an air quality
context, none are more puzzling or more tantalizing than those involving
| open space. At the crudest level, "open space" connotes the absence of
M development and thus the absence of pollutant emissions. This observation
has obvious implications for down wind locations, but since we cannot keep
all "upwind" areas free of development, the practical planning value of
the observation is limited. Still, the obvious should not be ignored,
| and a reasonable balance should be struck between open space and
_ development.
If we look at open space as a "sink" for pollution or a cleanser of
B the air, the question of scale becomes important. Large-scale vegetation
is effective in filtering out particulates (thus useful for industrial
| buffer zones), but much less so with respect to gaseous pollutants. In
the case of oxidant formation, pollutant transport occurs largely above
ground level, so is little affected by vegetation. On the other hand,
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vegetation at a receptor site is quite effective in reducing gaseous
pollutant levels experienced by persons at the site. Thus, the nature
and extent of landscaping at homes, work places, hospitals, schools, and I
the like are highly relevant. Unfortunately, specific guidelines are
hard to come by. |
Industrial or stationary pollution sources may be dealt with in a
local land use planning framework, but generally require individualized
attention. For the most part, decisions on industrial location will I
depend on the nature of the particular industry proposed, which is not
known at the advance planning stage. When a specific proposal is made, |
detailed diffusion studies may be done, or required of the industrial _
firm. Buffer zones could be considered at that time. Local air
pollution control agencies will enforce source controls and may consider I
the effects on ambient air quality. In those cases where local planning
policy can affect the establishment or expansion of an entire industrial
area, a thorough study of local meteorology can be made, comparing
alternative locations if possible. Where extensive industrial develop-
ment is planned, an "emission density" approach could be explored by the
locality.
Transportation Policies
In many ways, transportation is a regional problem, but local I
decisions are also significant from an air quality point of view. Local
governments are often instrumental in affecting or modifying state and |
federal highway decisions. While few counties build expressways, as «
Santa Clara County does in the Bay Area, almost all cities and counties
build or plan arterial streets and often these arterials carry high I
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traffic volumes.
In technical terms, roads can be analyzed as line sources and as
B area sources. Standard techniques measure the air pollution impact of a
road as line source chiefly in terms of carbon monoxide concentrations at
roadside and at various distances from the roadside. Pollutant concen-
trations fall off rapidly, and few line sources will show a significant
impact beyond the first few hundred feet from the roadside. Since the
analytical techniques are available, it is unfortunate that so far few
local planners have taken a hard look at line source impact and tried
I to use it in policy formulation. Although noise is usually a more
serious problem with respect to roads and adjacent land uses, there are
situations where air pollution can be viewed as a constraint. Analytical
procedures analogous to those now common for noise could be used locally.
True, there are no specific standards for roadside air quality other than
the federal ambient standards; but this should, not preclude planners
from proposing setback policies based on what the community considered
acceptable health risks from line source pollution.
Area source analysis can be employed where there is a fairly dense
network of roads and parking facilities in a local area as in a downtown
section or a shopping center. The result of the analysis will show levels
of a given pollutant averaged over the local area. These techniques are
I available, although not as standardized as for line sources, and special
M expertise is required. For both line and area sources, background
concentrations must also be considered.
I Another dimension to analyze, though more difficult to quantify,
involves the regional effects felt largely in terms of photochemical
| oxidant. When considering the air quality effects of roads, especially
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in a general planning context, the planner should be concerned with
regional as well as local effects--for most purposes, this means
oxidant as well as carbon monoxide.
Clearly traffic flow improvements may result from building new
highways and widening existing ones. Assuming no increase in total
traffic within a local area, the air quality impact of such improvements
should be positive because higher speeds and smoother flow reduce
emissions per vehicle/mile (for carbon monoxide and reactive hydro- I
carbons). However, it is not uncommon for highways to induce or enable
growth to take place, either locally or within a broader geographical
area. If this is the likely result, it should be reflected in air
quality analysis and planning. This means bucking the traditional highway
department thesis that highways always follow growth and never cause it, I
but it is (to switch the metaphor) a bull planners should take by the
horns. |
In defining planning and air quality relationships, great emphasis M
has properly been placed on public transit. There is no question about
the urgent need in metropolitan areas for alternative forms of transpor-
tation, nor is there any question that improving air quality is an
important component of that need. Nevertheless, a finer sense of I
discrimination is necessary with respect to the effects of public transit,
not least among planners. Simply stating the desirability or even the
imminence of some form of public transportation in a locality is not a I
substitute for hard thinking and technical analysis.
Plainly put, the role of transit is frequently overstated in |
planning documents, particularly its prospective effects in reducing air _
pollution. Whether this hyperbole occurs through an excess of zeal or
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for other reasons is moot. The fact is that it does occur, as evidenced
by many cases of over-optimism both in estimating modal split and in
anticipating the advent of public transit.
Just as locational relationships between land uses are crucial for
air quality, so is the relation of transit to particular land uses. It
is hard to quibble with the idea that a sports stadium should be located
| near a mass transit stop, or that mass transit should be extended to
im serve an airport. On the other hand, a transit station near a regional
shopping center may be of marginal benefit to air quality, and could even
be a net detriment because of the combined effect of auto traffic to the
two facilities. Moreover, mass transit may itself be a generator of
| growth, particularly where highway facilities are improved concurrently
with transit construction.
But clearly these caveats do not negate the potential of transit
I for reducing dependence on the automobile, or at least limiting the
growth rate of automotive travel. Nor is the local community's role in
| transit to be minimized. Mass transit systems are often regional in
_ scope, but many localities maintain extensive bus systems. Even the
small community can sometimes institute a bus system, or equally
important, do its land use planning with transit in mind. With recent
changes in the financing picture, one good test of a locality's commitment
to reduced automobile dependence may be the dollars it budgets for road
purposes as against public transit. Surely the local planner is relevant
here.
Transportation policies for improved air quality can also be related
to parking as an implementation tool. Aside from fees and surcharges,
parking measures may be divided into two principal categories, regulatory
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actions and provisions for public parking including off-street parking
requirements and off-street parking limitations.
Up until now local zoning ordinances and regulatory actions I
affecting private development have focused on requiring adequate off-
street parking. In many cases the problem was (and is) too little off-
street parking rather than too much. It is folly to expect this reality
to dissolve today or tomorrow. However, there are situations where
requirements can be lessened because of the ready availability and
adequacy of public transportation and the compactness of development,
as, around mass transit stops and in high-intensity downtown areas. In
San Francisco, off-street parking requirements were reduced or eliminated
some years ago in much of the downtown core area, pursuant to planning
and zoning studies. Obviously the intent was to reduce automobile usage, I
traffic congestion and air pollution.
The San Francisco downtown experience also illustrates the other I
side of the regulatory coin--off-street parking limitations. Not only
does San Francisco's zoning ordinance reduce parking requirements, it
also severely limits the voluntary provision of "accessory" parking.
For example, an office building can contain only a small amount of
parking in relation to its total floor area. This type of limitation |
can often be exercised on a case-by-case as well as through a uniform M
ordinance regulation, since large developments frequently require a
special permit from the city. In addition, parking can (and should)
be limited in downtown redevelopment projects, which are planned and
approved under special legal procedures. |
Few cities have the compactness and transit availability that «
downtown San Francisco has, and the regulatory measures employed there
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are not readily applicable in most places. In contrast, questions of
public parking supply and location are relevant in many jurisdictions,
Planning and construction of "fringe" parking facilities next to transit
stations, and refusal to build parking garages in the central core area,
are two examples of the use of parking as a tool to improve air quality.
Nor are such tools confined to large cities. Even a small community
can provide parking (either on or off-street) to serve a regional transit
stop, or encourage public transportation in lieu of building a parking
garage.
| The most important thing to realize about parking is that it cannot
be treated as a separate subject for planning and regulation, but must be
integrated with long-range land use and transportation planning, including
I transit. Thus, the concept of a "Parking Management Plan" is open to
considerable question; the idea that such a plan could be short-range in
| nature or regional in scope is also somewhat troubling.
Land Use Planning Methodology
It is unlikely that local land use and transportation planning will
I undergo drastic changes in method solely to accommodate air quality
considerations. Nor is it necessary or desirable that this occur. Air
quality can, however, be an initial constraint on local planning and a
"tuning" factor for plans. There are a number of air quality planning
considerations that local planners should be aware of, including basic
| assumptions, timing factors, General Plan quantification and "VMT"
reduction.
All long-range planning involves assumptions about the future. Air
I quality planning requires numerous assumptions relating not only to
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future land use and transportation parameters (themselves based on many
assumptions about human behavior and technology) but also to those
parameters more directly associated with air pollution, including control
technology, fuel usage and even meteorological trends.
In the land use transportation area, the most basic assumptions I
involve growth within the community and external to it. Whether or not «
an explicit local growth policy exists, it is necessary to project in-
ternal growth on a spatially distributed basis in order to engage in
meaningful air quality analysis. The simplest projection is an extra-
polation of past trends, but the local general planning process should if |
possible include one or more alternative growth and land use scenarios.
The objective is to arrive at a desirable growth level and pattern
through a feedback process, using air quality as part of the feedback. I
Growth external to the community can often be treated in a less
detailed fashion, since most air pollution impacts are local in origin.
When dealing with secondary pollutants such as oxidant, however, it may _
be necessary to pay more attention to external sources. It will often be
unfeasible to consider a large number of alternatives for external growth
for three reasons: quite a few jurisdictions may be involved; the data
may be hard to come by; and the sheer volume and complexity of data I
handling and manipulation could be a serious problem. Therefore, one
or two alternatives for external growth may have to be played off against
a greater number of scenarios for growth within the community.
The key assumptions related directly to air pollution are those
concerning automobile emission factors. Federal law provides for re- I
duction of up to 90% in emissions of carbon monoxide, reactive hydro-
carbons and oxides of nitrogen within a few years. Since old cars have
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M incomplete controls, overall emissions from the total automobile popula-
tion are expected to diminish year-by-year as old cars are scrapped and
new, highly-controlled vehicles replace them. More precisely, the
emission factors used for planning purposes should diminish every year,
|' at least for the next decade or so.
_ Underlying any given set of emission factors are: changes made by
Congress or the EPA in auto emission control requirements and deadlines;
the relation of car speed to emissions for various pollutants; data on
the actual effectiveness of already-existing emission controls as
I measured by testing of representative cars; the degree of control devices
maintenance that can be anticipated in the future; the "vehicle mix" used
as the basis for the emission factors (including car age distribution as
well as percentage of trucks); and the test cycle or modal configuration
on which the emission factors were based, e.g. whether single mode or
multi-modal, hot starts vs. cold starts, etc.
In view of the variety of factors mentioned and the controversial
I nature of many of them, there is ample justification for using alterna-
tive emission factor assumptions, or a range of assumptions, for long-
range planning purposes. The significance of this approach for air
quality projections can hardly be overestimated. Other important
assumptions for air quality planning concern transportation planning
I essentials--trip-making behavior factors like automobile occupancy ratios,
trip length and trip generation characteristics, and modal split (the
allocation of trips between motor vehicles and public transit). These
factors are based on professionally-educated guesses, and on land use
assumptions which in turn are based on other guesses.
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With respect to stationary sources of air pollution, the matter of _
future fuel usage is paramount. Assumptions must be made as to the amounts
of natural gas, high-sulfur oil, low-sulfur oil and coal that will be I
burned in electrical power plants and industrial boilers, in various
future years. These parameters will determine projected levels of sulfur vj|
dioxide. As any casual reader of the newspapers knows, future energy
sources are the subject of some uncertainty.
Virtually all assumptions used for projecting the future are based
to some degree on "soft" behavioral and policy considerations, however
quantitative and "hard" they may appear to be in print. Enough examples I
have been presented to make the point that most assumptions used in air
quality planning are not engraved on stone tablets but are subject to I
discussion, and if need be, revision. This cannot happen unless all
relevant assumptions are clearly defined and set forth--a seemingly
obvious principle frequently ignored even in voluminous studies. In many
cases, alternative assumptions should be used in air quality planning,
and the results under each alternative should be set forth. This latter I
principle is subject to practical limitations of computational capacity,
time and cost.
Development Timing Consideration^
There has long been a debate in the land use planning field between
those who-view the community General Plan as a fairly definite, end-state
ideal and those who see long-range planning more in terms of policies and
process. In recent years the latter view has tended to prevail. Among
other shortcomings, the static, end-state model ignores vital considera-
tions of development timing, which is increasingly recognized as important;
indeed, for air quality planning purposes it is crucial.
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The "traditional" General Plan, consisting of a colored map with
1
supporting text, gives some idea of what will happen where, but not
when or how much. On the other hand, the policies/process plan doesn't
always answer even the basic what and where . Air quality planning
| requires all of these elements --concreteness and specificity are required
_ in terms of magnitudes, spatial distribution and development timing.
Thus, policies planning must be accompanied by a more sophisticated,
I detailed and timephased version of the traditional colored wall map.
To repeat, a General Plan is not well suited to air quality
planning purposes without a temporal component. Where will development
_ take place within the next five years? What are the growth pressures
during that time period? The question of growth rate is crucial in
order to determine air quality levels in early years before auto
emission controls reach maximum effectiveness, and the relation between
air quality improvement due to auto emission controls and air quality
deterioration due to growth in any given time period. Thus, the General
Plan should be phased. This is happening anyway in the planning field;
air quality considerations could help it to happen faster and in more
places.
Failure to view future development in a temporal framework can
conceal air pollution problems. While a static, end-state General
V Plan may be "comprehensive" and spatially balanced, there can be
disequilibria during interim time periods before the plan is completely
carried out. For example, high-density development may be favored because
it will tend to support mass transit; but if the transit is not available
for ten years or more, the intense development may cause a serious
| interim air pollution problem. Concerned professionals might well feel
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that ten years of breathing polluted air cannot be glassed over as a B
"short-term" problem (to say nothing of the question of the degree to
which the mass transit will actually reduce pollution). To take another m
example, the General Plan may call for a "balanced" transportation
system of highways and transit, but if the highways are constructed first, 1
they may not only cause air pollution problems but also induce development
patterns which will destroy the feasibility of transit.
It should be noted that the problems of timing may be more manage-
able when large-scale development is phased in a specific manner and is
under unified control. Thus, a "New Town" may have an advantage in this fl
respect over a like amount of random and piecemeal development. rm
Quantifying the General Plan
Much has been said about the need to integrate air quality consider-
ations into the land use and transportation planning process. At the
present state of the art, the most promising possibility of achieving
this integration lies in quantification and analysis of existing and
proposed plans as a starting point, rather than attempting to include
air quality as an a. priori ingredient in the planning process. The I
approach is an iterative one starting from a plan developed without air tm
quality considerations, quantifying that plan and then taking action as
necessary and desired to accommodate air quality. Put in an obvious
fashion, a plan must exist before it can be quantified. Efforts have
been made to derive generalized "land use emission factors" in order to |
allow a building-block approach to land use planning with air quality
factors included at the outset. Such efforts have not been successful.
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Air quality planning methodology leans heavily on the quantification
of land use and transportation parameters on a spatially distributed basis.
I The purpose of projecting emissions may be to compare alternative General
Plans, to evaluate a plan in relation to air quality standards, or to
impose land use/transportation controls. For each of these purposes, a
A different degree of detail may be acceptable. At the grossest level,
total emissions within the community or planning area, to a rough order
of magnitude, might be sufficient for a particular purpose. At the other
extreme, emissions on a one-kilometer grid with a relatively high degree
| of precision might be required. In brief, the method of projecting
M emissions from a long-range plan depends on the purpose for which such
" quantification is desired.
An interesting aspect of plan quantification (and of air quality
planning in general) is that it tends to put land use and transportation
d' plans "on the spot" by taking them seriously and forcing their proposals
. to be considered as though they would be implemented. Decisions which are
* normally clouded over or deferred in General Plans must be "made" for
V purposes of analysis and evaluation. Nevertheless these decisions will
not have been "made" in a real (i.e., political) sense. This discrepancy
I can have educational value for decision-makers and the public at large.
Although emissions are the initial objective in quantifying a plan,
" they are not the final result desired in professional air quality planning.
Too often an "air quality" analysis stops with emissions and states or
implies that the task has been accomplished. There are situations
where emissions are an adequate surrogate for air quality, but such a
^ judgment can only be reached after taking into account two paramount facts:
* 1) the extent to which emissions of specific pollutants are proportional
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to ambient concentrations of those pollutants at a given location, and
2) the relationship of emissions to air quality standards.
Therefore, plan quantification can be a.complex matter requiring
the application of meteorological, air monitoring and statistical exper-
tise. While the process can be simplified to some degree, it is not m
advisable to undertake a serious project without the active assistance ti
or supervision of a group possessing such expertise, such as an air
pollution control agency or specialized consulting firm. M
"VMT" Reduction V
A simple and popular concept for relating air quality to land use/
transportation planning is Vehicle Miles Traveled (VMT). Since the auto-
mobile is the major source of pollution in most areas, a limitation on
automobile travel will lower pollution levels--hence the idea of VMT
reduction. M
I
This strategy can be applied in either a short-term or a long-term
context. EPA in its Transportation Control Plans has taken the short-
term approach, based on the mandate of the Clean Air Act for early
attainment of air quality standards. The measures advocated by EPA to W
reduce VMT have included exclusive bus lanes and ramp metering, greater if
carpool and bus use, parking surcharges and project review, and even
gasoline rationing. Many of these techniques have been evaluated for
their possible effectiveness in reducing VMT.
In a long-range planning sense, VMT can be a valuable tool in making 9
rough comparisons of alternative land use and transportation plans, as a m
parameter useful for plan quantification. However, its use for imple-
mentation and control purposes should be approached with extreme caution fl
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m because of the crude nature of its relationship to air quality. As
stated above, emissions are not a direct substitute for air quality.
M Carrying the process one step further, VMT is not a direct substitute
for emissions. One must consider questions involving emission factors,
J vehicle speeds, spatial distribution and temporal variation. Unless all
M relevant technical factors have been considered in detail, it is not valid
I
to impose location-specific regulatory controls based on VMT in the name
of air quality.
B A Personal Perspective
The objective of this paper has been to provide some overall
perspective on the fledgling field of air quality/land use planning at
the local level, as seen by a professional planner who works for a
m regional air pollution control district in California. The author has
ft not hesitated to venture opinions based on his professional background
and day-to-day experience. There is nothing sacred about these opinions,
I but they do stem from a fairly unique opportunity to observe and partici-
pate in both the air quality and land use sides of the equation. They
£ also stem from a personal conviction that planning for air quality is not
£ just a game to be played, but is an activity worth pursuing seriously
(albeit reasonably) in the interests of public health and welfare. With
ft this confessional prelude, a final group of hortatory comments follows,
addressed to the local planning community and to anyone else who cares to
| listen:
^ a) The cliche has it that air pollution is a regional, not a local
ft problem. The cliche is only partly right. Air pollution is in fact a
ft national, state, regional and local problem--with solutions required at
I
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each level of government. In at least two ways, air pollution must be I
viewed in a local framework: the effects of air pollution are usually
felt in a small, localized area around the sources of pollutant emissions; £
and the long-range solutions dependent on land use planning must be _
effectuated mainly at the local level. "
Conclusion: Don't rely exclusively on higher levels of government
--there is much to be done within the local community. Cities (and coun-
ties in some places) are not irrelevant. A
b) The hard evidence so far, together with the continuing resis-
tence of Detroit to cleaning up the automobile, provides insufficient W
assurance to prudent professionals that automobile emission controls
will be fully effective. A Congressional fiat is no substitute for
proven technology and demonstrated enforcement capability.
Conclusion: Land use and transportation planning should be both _
conservative and flexible--conservative with respect to the public health V
and welfare and flexible enough to take account of the evidence on emission
controls as it comes in, particularly over the next five years.
c) Pollutant emissions are very important, but they should not be V
confused with air quality. Meaningful planning and implementation for
air quality require detailed consideration of meteorology, temporal and P
spatial variations, air quality standards and if possible, photochemistry. «i
Conclusion: Don't undertake a serious air quality/land use planning
effort without expert technical assistance, including close cooperation
with the local or state air pollution control agency. And don't "simplify
can't balance interests unless those interests are first defined honestly
and thoroughly.
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d) Ambient air quality standards represent the "best judgment" of
the EPA, taking into account the available scientific evidence and
M allowing for a margin of safety in protecting the public health and
welfare. Like all governmental judgments they are political to a degree,
but they are not arbitrary and they have the sanction of law. Neverthe-
less, the air quality standards represent goals to be achieved, and there
are unresolved questions concerning how one decides whether those goals
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have in fact been satisfied. For example, what statistical "confidence
limits" are appropriate in predicting future violations of air quality
standards? Did Congress intend that air quality standards apply at every
M point in space? To what extent and over what areas can pollutant concen-
trations be area- averaged for prediction, planning and control purposes?
ft
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'
V
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Should compliance with air quality standards for "attainment" purposes
(to 1978) be measured in the same way as compliance for "maintenance"
purposes (after 1978)?
Conclusion: While employing the best available methodology and
technical expertise, those engaged in planning for air quality should
recognize that projected compliance with ambient air quality standards
is often a judgmental matter, not an all-or-nothing comparison of two
numbers. This is particularly the case in a long-range planning context.
While air quality standards cannot be ignored, don't settle for simplistic
criteria as to whether a plan "meets" or "does not meet" those standards.
e) Air quality considerations are frequently consistent with other
land use planning criteria, but this is not always the case. Several
examples on both sides have been given in this paper. Where air quality
support can be gained for otherwise desirable plans and projects this
should by all means be done, but data should not be strained to achieve
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this end.
Conclusion: In a general sense, clean air goes hand-in-hand with
"good planning", but don't sacrifice analytical integrity to support this I
statement in a specific case. If a proposal is good for housing or
transportation but demonstrably bad for air quality, say so. Where
trade-offs are to be made, the politicians should make them not the »
planners. The primary charge of the professional in air quality planning
is to do their best to ensure that first, air quality is not traded off
at the expense of the public health and welfare; and second, where
trade-offs are justifiable, they are made with full knowledge of the air j[
quality effects, based on technically sound analysis, carried out in an «
institutional framework that guarantees scientific integrity and broad
public exposure. M
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EMISSIONS ALLOCATIONS: A NEEDED FRAMEWORK FOR
RELATING AIR QUALITY CONTENT OF EIRs TO DECISION MAKING
Daniel Lieberman
Introduction
H Since the passage of the National Environmental Policy Act of 1969
(NEPA), the California Environmental Quality Act of 1970 (CEQA), and
m California Assembly Bill 889 in 1972, there has been a continuing
sophistication of air quality impact analysis in the reports required
f by these statutes. Report writers and developers have begun to analyze
^ alternatives and have been able to project and quantify the emissions
associated with projects including those from projected automotive
traffic.
Some progress has been made in projecting levels of conservative
pollutants associated with projects and including forecast background
_ levels for use in decision making. No methodology for relating precursors
" of oxidant from individual projects to future oxidant levels in the basin
seems to be operative. Instead a steadily growing frustration is
developing with the utility of the massive amounts of data being
V accumulated as a guide in decision making. Whether to proceed with
- projects or to modify projects so as to relate them to future oxidant
w readings in the atmosphere is a continuous topic of discussion.
Interrelation of the Land Use and Transportation Planning Processes
In August of 1973, in response to California SB 981 (1972) the
Air Resources Board transmitted a Report to the Legislature on Guidelines
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for Relating Air Pollution Control to Land Use and Transportation M
Planning in the State of California. This report contains as an
appendix, a report to the Air Resources Board by Livingston and Blayney, B
City and Regional Planners, which proposed six steps to integrate air quality
goals into the land use and transportation planning processes: |
1. Compile detailed inventories of air polluting emissions _
in planning sub-areas of air basins. The present V
inventories for counties and air basins are too *
general for detailed air quality planning.
2. Designate maximum emissions allowable in each planning v
sub-area to achieve and maintain air quality standards,
based on an analysis of present air quality and the £
environmental capacity of the atmosphere to absorb M
air pollutants and still maintain air quality standards.
3. Project planning sub-area emissions likely to be V
generated by sources indicated in land use and trans- "
portation plans for designated future time periods,
say 1985 and 1995, and compare these emissions with
the allowable emissions limits. ^
4. Evaluate and revise land use and transportation ^
plans so that prescribed emissions limits would not
be exceeded.
5. Adopt and implement land use and transportation plans A
which are prepared to meet air quality goals and ij
standards.
6. Monitor public and private development through a refined Jj
environmental impact assessment process in which
emissions projected directly or indirectly by projects _
are accounted for in environmental impact reports.
All of these steps were proposed primarily as an aid to planning. An
examination shows the process provides a framework for decision-making
with regard to the air quality impact of the EIRs. jfi
Decision making on oxidant precursors does not seem manageable
without looking at the cumulative impact of growth and development.
Rollback models have related total emissions in an air basin to future
i
air quality. Technical judgment should make us aware that the spatial
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flj distribution of precursors of oxidant along a wind trajectory will affect
future air quality readings. Analyzing individual projects without being
B aware of the future cumulative growth or reduction in emissions in a
spatial and temporal analysis makes it very difficult if not impossible
to provide decisions on whether a project should be approved.
Response to the report has been varied. The question of a govern-
mental mechanism has been a central issue in most comments. Many responses
tend to advocate the commentor's organization for carrying out the
^ recommended process but do not question the requirement for a basinwide
M framework. Questions have also been asked about the technical approaches
m to carry out the process.
The Emissions Allocation Process
The emissions allocation process is envisioned to work as follows:
V A rollback model would be used to develop basinwide allowable emissions
for each category of pollutant. The rollback model is the methodology
used in the State Air Implementation Plan (SIP) for determining allowable
emissions. Local existing planning jurisdictions--county, city, and when
necessary, special districts--would then be assigned emission limits. The
initial allocation would be based on the following formula:
I
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E planning sub-area base year E allowable in planning sub-area
E air basin base year E allowable in air basin (SIP)
E = emissions for each pollutant category
If planning jurisdictions are extremely large, agreements on assignment
of limits for sub-areas would be required. Local planners would use
| existing methods to predict emissions from their plans. This would
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involve both emissions from mobile sources using projected traffic and _
appropriate vehicle emission factors, and emissions from stationary *
sources, point and area. Such land use based emission factors (as M
described previously) could be related to current emission factors used
in developing emission inventories. As sophistication in projecting |
future emissions develops, new emission factors extablished for _
forecasting would be utilized. Obviously, there will be uncertainties
in many areas as to which stationary industrial sources would be built.
It is presumed that in those areas where it was not possible to predict
emissions because of an inability to specify the future type of industrial m
or commercial establishments that would be contained in a geographical
, _ __
the planning area would be applied by the planners. The projected
allowable emissions would provide a basis for comparison in approving
or disapproving projects proposed for the area. When the cumulative
prelected emissions associated with a proposed project and the other
r_ __, i ^ _.._. .. _ -**-- --,
project would be refused a permit or plans would be modified so that the
sum total of emissions in the planning area do not exceed the limit of
emissions allocated. I
This is a technical structure, but it does provide a feasible
process for decision-making. In the near future computer photochemical B
models are expected to be available. These would allow more flexibility m
in designating emissions allocations and in making tradeoffs between *
allocations to different areas.
The councils of governments (COGs) are expected to be a portion of
the process. The role of the COGs, as flexibility and tradeoffs enter the |
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picture, would be analogous with regard to air limitations as they now
are with regard to funding limitations on grants from the federal govem-
M ment. When there is a limited amount of grant money for the development
of sewage facilities in a planning area, the COGs act as a mediator between
local jurisdictions and comment on grant applications so that an equitable
distribution of grant funds is made. The emissions allocations limits
to protect the health of the people can be mediated in the same fashion.
< Predictions of future emissions and air quality in evaluating the
present state of the art are not precise but neither is the result of
V other long-range planning. The question of energy concerns, the profi-
tability of private enterprise, changes in birth rate, the changing
m fortunes of the aerospace industry, etc. are unknown factors which the
m planning process compensates for as more information becomes available.
The emissions allocations framework provides a basis for decision
V making. Questions have been raised as to interference with achievement
of economic and social goals of a region. In the long range timeframe,
it would seem that air quality standards which are based on health should
f not be subject to tradeoffs. Congress has made this decision in the
Clean Air Act of 1970. Achievement of health-based standards is a social
goal. Economic and other social goals can be achieved using air quality
as a constraint.
In addition, if in the initial analysis there is a serious conflict
1 between future air quality and other goals, the regulatory/political
process would result in the inclusion of economic and social considerations
fl| in setting the allowable basinwide emissions. These tradeoffs can only
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be realistically made after an initial emissions allocation and a serious
effort to develop land use and transportation plans compatible with these
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allocations have been made. ^
The California Legislature has mandated consideration of air
quality in decision-making in the California Environmental Quality Act. ^
A framework to cope with the cumulative impact of many small projects and
to provide a basis for decision-making is necessary. Emissions allocations |
techniques form that framework. There may be questions about the ^
institutions that allocate emissions, carry out the review and made *
decisions, but the need is here, the tools are available, and we should be V
deciding on the institutions to carry out the process or propose an
appropriate, effective alternative. M
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BIBLIOGRAPHY
Clean Air Act (42 USC 1857 et seq.) includes the Clean Air Act of 1963
(PL 88-206), and amendments made by the Motor Vehicle Air Pollution
Control Act (PL 89-272, October 20, 1965), the Clean Air Act
amendments of 1966 (PL 89-675, October 25, 1966), the Air Quality
Act of 1967 (PL 90-148, November 21, 1967), and the Clean Air
Act amendments of 1970 (PL 91-604, December 31, 1970).
The National Environmental Policy Act of 1969, 42 USC § 4321-47 (1970).
The California Environmental Quality Act of 1969 as amended by AB 889
(Statutes of 1972).
Resources Agency Guidelines for the California Environmental Quality Act
published December 17, 1973.
California Air Resources Board, A Report to the Legislature on Guidelines
for Relating Air Pollution Control to Land Use and Transportation
Planning in the State of California, August 1973.
Environmental Protection Agency, Guide for Compiling a Comprehensive
Emission Inventory (Revised). Office of Air Quality Planning and
Standards, Research Triangle Park, North Carolina, March 1973.
, Compilation of Air Pollutant Emission Factors, Research
Triangle Park, North Carolina, April 1973, AP442.
, Compilation of Air Pollutant Emission Factors, Supplement
2. Research Triangle Park, North Carolina, September 1973. AP 42
Supplement 2.
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1
Dan Leiberman, Moderator
PANEL DISCUSSION
INTERACTION OF THE PLANNING AND REGULATORY COMMUNITIES
There has been a lot of talk this morning about institutions, and I
think the question of institutions comes down to what people are doing
now. And possibly by listening to some of the people here today, and
asking questions, we can get some understanding of where we are now,
because in the last two years we have been developing the institutions in
IB the framework of the existing law. The law did not make the institutional
constraints clear, but I think that part of what you're interested in is--
V what do you expect from regulatory agencies and what can you do with
planning agencies?
The gentlemen here- -John Wise on the left is the Chief of Inter -
agencies Activities of EPA Region 9. Milton Feldstein is the Deputy
Air Pollution Control Officer in the Bay Area Air Pollution Control
1 District. Bill Rugg is the planning director for the City of San
Leandro. Graham Smith is an environmental advisor to Los Angeles'
| Mayor Bradley.
M JOHN WISE: IWiat I plan to focus my remarks on this afternoon is
' to give an overview of EPA's role in the question of the inter-action of
planning and regulatory communities from an air quality perspective.
Before I begin I note that David Morell from our Washington office gave a
J| talk this morning and I may be retracking a bit of his thinking, so if I
» do please bear with me. I do hope to go beyond just a simple enumeration
* of where EPA is with respect to our individual programs and regulations,
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and try to weave the interface of the regulations into the planning m
community. There are three basic issues or subjects which I want to
focus on today, which provide a fairly good format for trying to bring
together the considerations of regulatory systems under the Clean Air
Act, as we seek to attain and maintain national Ambient Air Quality 1
standards, and the traditional role which is played by planners, whether ^
they are state planners, regional planners, local planners, or any other
kind of planning fraternity. I
First of all, let me give a very brief background sketch on the kind
of regulatory system we're dealing with. The Clean Air Act specifies J[
rather broad but at the same time specific mandates on EPA to attain and «
maintain national Ambient Air Quality standards. Within that general
mandate EPA has over the last three years come up with several distinct
and somewhat different strategies. The strategies are in and of them-
selves somewhat single purpose. For example, we have strategies to attain Jj
the standards; we have strategies to maintain the standards; and now,
we're developing the standards to prevent the significant deterioration '
of air quality. The point that becomes rather cumbersome in this whole It
regulatory system, is that we are imposing requirements which in and of
themselves are single purpose and tend to be rather cumbersome. Relating
those kinds of requirements to the planning community presents a real
obstacle. A very major difficulty which we're facing here today is how w
to relate EPA's single purpose requirements to the broad and more general
concerns of the planning community.
Three specific issues which we want to focus on today are the issues V
of air quality and transportation planning; air quality and the question
I
of facilities siting; and the question of air quality with respect to
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growth and development.
Let's deal with the first one first: the question of air quality
fl and transportation planning. As most of you know, and I'm sure some of
you I see in the audience here are working intimately within this area,
the 1973 Federal Aid Highway Act specifies in section 109-J that the
projects and plans conceived under federal funding shall be consistant
m with the goals and objectives of the Clean Air Act. To implement this,
the Federal Highway Administration has put together a set of guidelines
known as the air quality guidelines which mandate a consistency between
transportation planning and transportation projects and the applicable
state air implementation plan. This poses an overview requirement that
I all transportation facilities must henceforth be consistent with the
M overall goal of attaining and maintaining air quality. EPA has a role to
play in all of this, and our role is principally in terms of implementing
our own regulatory programs. We serve as a consultant to the Federal
Highway Administration in actually implementing these guidelines. In
| the course of implementation we've begun to run into some very significant
4* aspects of transportation planning and how that planning relates to the
more fundamental land-use planning which is going on. I believe it's
clear to all of us by now that this is a rather primitive area in terms
of relating transportation systems and transportation plans to what is on
£ the ground in terms of land-use planning and land-use decision making. To
m the extent that the Federal Highway Administration and EPA acting together
in implementing the air quality guidelines, are going to come up with an
tt overall constraint which is then imposed on transportation facility
planning, we're going to again force the system into consideration of
J the key elements of transportation and air quality in comprehensive
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land-use plans. Now, the local planning community, be it state, regional,
or local planners, must certainly be aware of this. This is a very major
and powerful tool which opens the door towards mutual cooperation and
integrating the three distinct areas of air quality, land-use and
transportation.
Somewhat related to this is the second issue which I want to dis-
cuss, the issue of the siting of key facilities. This of course has been 9
a traditional role which has been played by local general purpose
governments in their traditional prerogative of making land-use decisions.
These decisions include the location of residential areas, industrial I
areas, commercial areas by means of a zoning map, but more specifically
individual approval through the permit process, determining where speci- I
fically a shopping center or an airport may be located. JM
Again, there are air quality implications which are now being
superimposed on that traditional decision-making process. As you I
probably learned this morning, these take the form of the review and
permit authority on the construction of a so-called indirect source |
(a key facility such as a highway segment with a certain traffic load, £.
an airport, or a major shopping center). These key siting decisions as
they're related to air quality then impose an additional constraint on fl
the local planning community. How do you rationalize land-use decisions
within the explicit mandates to attain and maintain the air quality
standards? _
Let's proceed on to the third area I want to talk about, and this l
is more generalized in scope: the relationship between air quality and
the generalized process of growth and development within a community.
Here again EPA, in our regulatory wisdom, is coming up with another
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M program, another constraint on the whole system, in that we are now
mandating that a new concept of air quality maintenance planning be
I developed by the state or state designated agencies, to begin to relate to
the maintenance of the national Ambient Air Quality standards, over time,
specifically over a 10-year period of time. What we're talking about is
«| a continuing planning process really, and when we speak in terms of
planning over time we must accomodate the rates of change or growth, if
you will, of population, the rates of change of vehicle miles traveled,
the economic and social indicators, and we must begin to work these kinds
m of indicators into the process of maintaining air quality. All of this
jf " is going to lead us to the point where the regulatory system finally comes
to grips with the local planning community. That to really effectively
W maintain standards over a long period of time using all available control
technologies and control methodologies, including land-use and transpor-
| tation controls, we must begin to say, okay the regulatory system cannot
_ function by itself. Here at last is an institutional focus where we can
begin to put everything together. I'm sure some of the other speakers
* will build upon this theme that perhaps we're leading to a point where
the regulatory system can now step back and say here are the overall
P requirements--this is what has to be done--and let's put together the
local, state, and regional institutions to accomplish that. Following
* me will be representatives from some of those institutions which will
provide you with specific insight on some of these general programs
which I've outlined.
M MILTON FELDSTEIN: I hope you will forgive me in terms of my remarks which
relate more to a technical background than to a planning background.
I
Perhaps there's an oversimplification when one looks at the complex
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inter-relationships between land-use planning and air-quality, if one looks
at it from an engineering or chemical point of view. Recognizing that
this is a tremendous over-simplification, I would like to briefly point I
out some of the aspects of this kind of relationship that is presently
going on at the Bay Area Air Pollution Control District. During the
morning, and I'm sure for the next day or two, you'll be hearing a lot of f
information about how one determines the air quality impact of a particu-
lar complex source and what kind of specific engineering and technical I
calculations have to be made. All of this, I think, leads to the concept
that we are not dealing with abstractions--we're dealing with specific m
emissions, we're dealing with emissions primarily, at least in the land A
use planning aspect, of the so-called indirect or complex source, the
emissions which come from the attraction of motor vehicles. V
Now it was mentioned earlier that the regulatory process which must
be instituted to at least get a handle on a control of these kinds of |
developments generally occurs through a permit kind of system. The Bay
Area Air Pollution Control District (BAAPCD), along with other districts
in the State of California, has had a permit system and up until this *
point in time it has been concerned primarily with stationary source
emissions. No one gets excited when one has to apply for a permit for g
a new refinery or a new chemical plant or a cement plant in terms of the ^
standards and criteria that have to be met, consistent with maintaining
and achieving air quality standards.
In the BAAPCD, which developed a permit system only two years ago,
this same approach is also true. There are three tests that a new
stationary source has to meet when it applies for a permit in relationship
to emissions: The first test is that that source has to meet the emissions 9
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regulatory requirements that the district has established (we have
established emission limits for the five primary contaminants: sulphur
oxides , particular matter and so on) ; each new source has to meet that
emission limitation, otherwise, a permit can be denied for that source.
The second test is that even though this particular stationary source
A meets the emission limitations, the emissions must not cause an air
quality standard to be exceeded. Even though one meets the particulate
rule or the sulphur dioxide rule, the emissions within that limitation
cannot cause downwind an air quality standard for that emission to be
| exceeded. The last test is that even though the emissions meet the
j» regulatory requirements, the permit may be denied if the emissions occur
in an area where an air quality standard is already exceeded. So these
V are the three tests which are applied to stationary sources which apply
for permits to construct and operate.
P The indirect source rule, which is currently being considered by the
Board of Directors of the BAAPCD follows similar reasoning. There are
* three questions that the Board is considering. I should emphasize that at
~fl the present time, these regulations are undergoind public hearing. There
were two public hearings held; one in May and one in June, and another
| one is to be held this coming Thursday, in which input from all diverse
_ views is being received by the Board. I hasten to add that the Board of
Directors of the district is the group charged with the responsibility
of developing the regulations which, when adopted, become part of the
enforcement process of the district as a whole.
M The three areas that the Board is currently receiving testimony on
relate to the following items: First, what sources should come under
9 private review? What are the cut-off criteria and what size of an
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indirect source should be reviewed in terms of its impact on air quality?
Obviously a single family dwelling is at one end of the scale, and a
10,000 unit residential development is at the extreme other end of the A
scale. .What is the kind of numbers that we're talking about which would
bring these sources before the permit section of the district, if you
will, in order to determine whether or not that particular project would
indeed have an effect on air quality. I'll mention in a moment what the V
cut-off criteria currently being considered are, so that you may have
those in mind.
The second major question which is appearing in public testimony
is what is the grandfather, or the grandparent, if you will, type of
legislation which would permit ongoing projects (projects which have had 1
substantial investments in time and money and effort) to be excluded from ^
review of these indirect sources?
The third question and here again I feel one of the most serious I
questions to come in public testimony before the Board, is what are the
appeal procedures? What are the social and economic factors that should If
be considered in the granting or denial of a particular indirect source? ^.
This is a problem which has no recognition when one looks unilaterally at *
the requirements of air quality over any other requirements. The Board of
Directors has made it clear that it is our purpose to at least provide a
mechanism whereby a review can occur if the air pollution control officer I
for example denied a particular project on the basis of air quality. Such _
a review would consider social and economic problems which may result from
the building or the denial of the building of that particular project.
This essentially then is the kind of approach that a local agency, a
regional agency in this case, comprised of the nine counties that surround
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IB the Bay Area, is attempting to do, in order to bring under its jurisdiction
the review of indirect sources related to their impact on air quality.
I I mentioned a moment ago I would briefly mention the kind of sizes
that we're talking about now,relative to bringing a source under review.
I And I must emphasize that this does not mean that any such source that
» is required to have a permit and be reviewed will automatically be denied.
You, as planners, I am sure know the mitigating effects that can occur in
developments in terms of reducing vehicle miles traveled, in terms of
siting (as was mentioned earlier) so that the impact on air quality would
| not be directly associated with the particular project that is being
^ built. So the staff has recommended to the Board, and again I must
* emphasize that this is all preliminary in terms of the testimony that will
V appear before the Board, that any non-residential indirect source which
has a new associated parking area with a capacity of 1000 cars or more be
subject to permit review, not be_ denied, but be subject to permit review.
_ Additionally, any existing facility which adds 500 or more parking places;
any facility which induces 1000 or more vehicle trip ends in any one hour
period or 5000 or more vehicle trip ends in any 8 hour period; any road
or highway with the following anticipated average annual daily traffic
I volumes with 10 years: for new roads--20,000 or more vehicles per day,
for modified roads--an increase of 10,000 vehicles per day; any airport
with the following expected aircraft operation within the next 10 years:
new airports--50,000 or more commercial operations, modified airports--
the same number; and finally any residential development with greater than
1000 units. These have been proposed and I think they follow fairly
closely the EPA proposals and they followed the original proposals of the
I Air Resources Board (ARE) until the ARE decided to delay discussion of
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this topic.
In terms of those sources which would be required to get a permit to ii
construct and a permit to operate, the permit would be based upon the M
impact on air quality after making a thorough environmental impact study
on air quality emissions relative to that project. In summary, I think
then we are now facing in the Bay Area, at least from a local regulatory
agency, intense discussions on the part of those who are affected,
developers, and those who will be effected, the citizens who feel that air m
quality should be an important constraint in planning.
I think we have to recognize that there are some problems in terms
of assessing the air quality impact of these particular sources. For
example, the technology in terms of assessing the impact on oxidant, which 1
is the major air pollutant in the Bay Area, related to the emission of ^
hydrocarbon, is still in a state of infancy. And the thing that concerns
me, someone who is inter-twined with these kinds of regulations, is that ff
we know that as soon as a specific project is denied on the basis of its
impact on oxidant formation, the procedure will revert to the courts. £
The courts will make the final decision as to whether or not the technology »
we had was adequate to deny the permit for a particular source. Be that
as it may, I think that indirect source controls are a first step in the B
necessary long-range planning which you will be discussing for the next
two days in terms of bringing all development at least within the con-
straints of air quality along with other constraints that now exist in
long-range planning.
BILL RLfGG: I'll have to admit to feeling a little bit like a sacrificial
lamb this afternoon--! think they needed someone here who is a local
planner from a small community to come up here and raise a little hell-- I
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« and I'm about to do that. In fact George said that one of the things my
assignment included was to stir people up after lunch. Anyway I'm a
registered student like all of you here, and I don't claim to any more
expertise any more than any of you have, but I gather that my vantage
jj point as a local land-use planner may be a little bit different. As I
recall about a fifth of us here are local planners. So, what I will do
is to give you some observations from a guy who's on the firing line most
I of the time, a guy who meets face to face with the developer who walks in
with his plan, and in fact, I double in brass as a developer myself in a
way, because in San Leandro we have a combined office--the planning function
_ and the redevelopment function are in the same office--and so I end up
half the time trying to beat my own building codes as the redevelopment
director at the same time. So I really think I have a fair view of how
the poor developer feels when he's confronted not only with EPA but with
I BCDC, the Seismic Hazards Act, and the Environmental Quality Act--some
very large and expensive unknowns before he even gets into the business.
Well, first I'd like to thank both the Sierra Club and EPA for
getting us all here today. Because without that 2x4 hitting us on the
side of the head last fall--the parking surcharge--! don't think our
attendance would have been so great. At least, if nothing else, it got
our attention. I wanted to say something nice about EPA because I may
I not say anything nice about EPA during the rest of my remarks. However,
there is a real problem--I'd like to get a little information for myself
about you--a little bit more than Warren Jones gave us this morning by
asking a couple of questions: How many of you here are City Councilmen
or members of the Board of Supervisors. One. How many of you are planners
| from an operating transit district? Not CALTRANS, but an operating transit
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district. None. Maybe I don't need to go any further on that. jl
Anyway, my purpose here is to point out some frustrations about what
you heard here this morning and about what's been published. I would £
like to offer six (I've been writing these down during the morning)-- _
I can probably add a few more and I'm sure you can too, but let me lay
six different ones on you for argument. Again I say these are frustra- f|
tions, they do not mean there are not answers to them, they just mean that
I do not know what those answers are. I'm before you as a modestly I
informed planner--! don't proclaim to be an expertbut if I don't know
the answers, the chances are that an awful lot of other planners and cer-
tainly decision makers don't know them either. So perhaps one of those 4|
problems is getting the word out.
Number one, we're talking about land-use planning and air quality, ff
and land-use planning is not a technical problem as is air quality
planning; it is a people problem. What we're really talking about
in getting to amend our land-use planning techniques, is the changing of
habit patterns of people. There is nothing much more difficult in this
big wide world than the changing of habit patterns of people. We've got to I
take people as they are, I think, and try to figure out, perhaps modestly,
how to circumvent their prime moving impulses about driving automobiles. £
That is not going to be easy, and it is not going to be answered by the
Federal Register.
Second, are a whole series of things: but one of them, to start I
off with is that the regulations such as those that Milt Feldstein has
just mentioned, are so vague, that I cannot analyze their impact on £
land-use. I testified against the ARE regulations on indirect sources
I
for that particular reason. I was unable, in reading the regulations as *
I
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proposed, to tell my community what those would do in terms of land-use
planning changes. Now somebody presumably knows this, but I think it is
something all of us are going to need to know before we can buy the concept.
I don't know, for instance, what specific tests are going to be applied
to any indirect source in my community. How do I know in advance? How do
M- I inform the developer? How do I know for the projects that I run? Are
they going to be turned down or not turned down or conditioned? What are
the specific tests? What land-use patterns are going to emerge? And I
thought it was kind of interesting this morning to find out there is a
| study now going on, now that the regulations have already been adopted,
« to find out what land-use patterns might emerge. As Ralph Mead said, he's
not ready to say that high density is better than low density. Well I'm
f| not either. The point is we don't know what density is the right density
and under the circumstances what energy problems are created?
| My third frustration I guess, is the large number of apparent
control strategies which have been apparently ignored. It was interesting
* to note that there has been no EIR appear in the federal regulations or
1| the state. I'd like to know what the section might have said that covered
what alternatives to the proposed plan are proposed. But who is pushing
g the transit districts? There are no transit planners here today,
apparently. Who is pushing the differential parking fees and the differ-
ential bridge tolls and the horsepower tax, the various selective disin-
centives that could affect specific kinds of trips, not just all trips?
Fourth, there seems to be no money to help with the alternatives.
We need additional studies. We need help on more busses, on PRT's, on
people movers. We need all kinds of help to provide alternatives to
private vehicles. If any of you have applied for grants recently, you
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are familiar with the fact that there are very few, certainly nothing
available that is going to match the problem. But, if our objective is m
not just to curtail mobility, we've got to provide some alternatives. So H
far, the regulations we've heard are largely negative, and will tend to
curtail mobility. That has to be the result, as far as I can see.
Fifth, there has been a very distinct lack of local input, and I'm
not talking about public hearings. As every public local land-use planner |
knows, by the time he gets to public hearings, it's too late to logic. «
I'm talking about early work with your friendly local planner, EPA, to *
devise regulations and strategies that can be implemented by local govern- f
ments. And the only way I know of that that can be done is to work with
local planners early, before the regulations are adopted, not afterwards, g
or at least not at a public hearing when the large amount of public
testimony is for or against, and not what the alternatives might be. '
Finally, sixth, we're talking again about a large single-purpose
agency, or agencies, trying to solve a single problem without really
interacting with all the other problems. Now, if my function here may be
a little different, I'd like to end on a positive note. That may not be
easy but I'll try.
We do need to have some land-use rules and so far we haven't really
got any. As I said we don't seem to know what our best densities are,
and what our alternatives are. I'm not even sure we know what our
objectives are. Basic to setting up our objective, I think would be the
proposition that the solution to this problem should not aggravate other m
problems. So far in the planning business, our failure to work with the fl|
relationships between problems has led to our current preoccupation with
drastic single purpose solutions, developed by large single purpose agencies. I
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The second would be that most of our current plans and our current
problem activities tend to seriously discount the future. I don't know
how many of you are involved in future research and this kind of thing,
but the term discounting has a real connotation here: it simply means
9 that you place less value on a future solution than you do on a current
M short term solution. Here we're looking at--we've got to solve the air
quality problem right now--and what the results of this solution might
be in 20 years is discounted at 5% per year. What does that give you?
Zero. It is a little like the old story, and I probably shouldn't tell
| it, but you all know it anyway--about the old bull and the young bull that
M were standing on top of the hill looking at all of the cows down below.
The young bull said let's run down the hill and get a cow. And the old
IB bull said let's walk down the hill and get all the cows--I'm not even sure
we can find the cows at this point.
Yet anyway, whatever is our real planning objective? I don't think,
^ from my standpoint, that it's just to improve air quality, because that's
something I cannot relate to, and neither can my city council. They don't
know how to do that. It's too general. But what is our objective? I
think it is to reduce vehicle miles traveled, to put it very simply. Now,
that's something that people can at least understand--the lay person can
understand what reducing vehicle miles traveled is. It does take a little
explanation, but it is possible to explain it. You can go one step
further, how do you reduce vehicles miles traveled? Not by reducing
mobility, which has some tremendously serious social and economic effects
as we've said, but by doing two other things: minimizing the need for
mobility, and providing alternative forms of mobility. Now this is where
it's at, I think, and here I'm putting up a straw person for you to shoot
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at--two of than actually. If you don't agree, you're going to say so-- M
but from a land-use planner's standpoint, these two things are under-
standable, and the planner can sit down and try to figure out what kinds V
of land-use planning changes can be made in the community that will either
in the long run reduce the need for mobility (Ralph Mead alluded to some £
of those this morning such as locational relationships), but also provide M
alternative forms of mobility, and I've mentioned some of those too.
One of the things that I would like to suggest, and this is why I asked if
there were any transit district planners here, is that in reviewing
applications from developers, we habitually say, first off, how many park- I
ing spaces are you going to provide, Mr. Developer? Secondly, what street
widening are we going to hook you for? That's about where it ends. From
now on, however, we're going to have to include on our planning review
team those transit planners from the operating transit agency, most of
which don't exist now. We must ask, how can this development be best
served by public transportation--not how much street widening would we
get, and how many parking spaces, but what kind of a shuttle system, or
can you build a bus shelter, or what can we do to improve the public
transit access to that development? These relationships don't exist now;
they're the kinds of things we're going to have to work on.
I would end with an appeal to all of you from EPA, and your bosses,
who may or may not be out there in the audience, to please get together
with your local planners, and your planning directors in particular. Let's m
try to work out what this jargon that we all use--land-use impact of air
quality regulations--really means to the individual city councilman who
makes that final decision.
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GRAHAM SMITH: I really feel like a visitor today, although Berkeley is
* my home town. Also, I notice in the program there is a considerable
domination of Northern Californians and I feel a little sensitive about
being from the air pollution capital of the world. The title of the
I panel, you know, is Interaction of the Planning and Regulatory Communities,
and ever since I went back to school to study planning, I have been
profoundly taken with the lack of interaction of the planning and regula-
tory communities in any kind of planning one may wish to talk about.
Kerry Mulligan, who was the head of the State Water Resources Control
Board some time ago, said he knew a guy who was planning to sleep with
Raquel Welsh for years, but it was the implementation he couldn't figure
out. The circumstances we have before us here are compelling some very
m lively action now, and I think perhaps it's going to start getting very
interesting. For planners, we're finding that in the city we're finding
it first at the regulatory end, and we're having a little difficulty
bringing some of our planners along. Let me illustrate that.
I The society today seems to be creating institutions before it knows
m what to do under those institutions. It knows the outcome, this is a
very interesting switch to outcome type of planning rather than input
measurement. The Coastal Commissions are a beautiful example; the people
had a idea,, they wanted some rational thought process applied to the use
| of the coast, they didn't know what the processes should be and when it
m came time to start hiring prople for the new Commissions one may seriously
question the qualifications. I taught a year of Coastal Planning at U.S.C.
and it was hard to get the students to take it seriously because at that
time a law didn't exist. In the same sense, in a very comparable fashion,
| the Clean Air Act was passed. The Feds, very properly I think, tossed
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the ball to the states and said "You do it--you achieve this outcome--and
you do it by this time." The states--in the case of the State of Calif-
ornia, and this is some time ago--pretty much scoffed at the standards,
and at the deadlines for that matter. I remember Ari Hagen Smith saying
that he thought there would be a Boston Tea Party if ever the Feds tried
to enforce the act. In the same sense down South, which I think may be
more characteristic of the existing institution, the Los Angeles County
Air Pollution Control District scoffed, in fact rancorously, and said the m
whole thing was silly.
Beyond that, there was a separation of course, between the county
air pollution control district which has single purpose air pollution
control functions, and the city planning departments. Land use has |
traditionally been a city function, and our city planning department m
reflects a knowledge only of land use at this time. Correspondingly the
Air Pollution Control District only seems to know about reciprocity between
hydrocarbons and oxides of nitrogen, and puts no stock in any other
techniques. I'm using a little poetry or color here to try and make the |
point. ^
What are we doing in Los Angeles in City Planning in relation to air *
pollution? I want you to understand that we have huge departments, 214
people in our planning department and they've been there a long time and
we have a new mayor. We have been a rather sleepy city in the past--now p
for 11 months--and therefore I do not want to hang the mayor, yet, for
some of the things I'm going to say about the way we're approaching the
problem. All we do in the City of Los Angeles is review air quality
considerations in environmental impact reports. We have a 12 person unit
in the planning department reviewing environmental impact reports, and I
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someone there generally reviews what the developer has proposed will be
* the air quality impact. I would point out that at the same time in the
planning department, the people who decide zoning or the granting of
sub-division permits and so forth, are going ahead on their own. So
there is a good question as to just how much of a role the EIR process
plays. Remember we're talking first about air quality considerations.
We're now within the City Planning Department, and we've just sort of
eliminated air quality considerations under the EIR. So, there is very
slight consideration. We have our own department of environmental quality
that has one air pollution specialist, and they have discretionary review
over EIRs, the very important ones, and so forth. I have yet to see that
any of their reviews have played a very significant role in granting or
denying approval on a project. So, we're really very far down the
line.
I'd like to point out that the Council is supposedly, by charter,
the policy making body in the city. There's nothing more that I dread
| than to go into council to explain the Mayor's position on one or another
m of the aspects of the Clean Air Act. There are 15 gentlemen who are
utterly oblivious--perhaps two or three of them have some sense of the
intricacies of the Clean Air Act. My best job I think, was once about a
year ago to get across the major provisions of the Act and their rela-
| tionships in a three hour seminar. We're all learning what the law means,
^ slowly and surely, but the Councilmen have no idea at all and don't have
any time to learn. How then, are we going to move to develop something
that is concrete both institutionally and substantively in terms of what
we want to do. This should be important to every planner here, or
anyone in local government. My gut sense now is that EPA did sort of get
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its ears pinned back in the parking surcharge, going through the other
process with the built-in delays from state to local government, and they
are going to short-circuit things if they can and go directly to local I
government. We're all for that and I think that the City of Los Angeles
will try to be in the vanguard, to the best of it's ability as a peculiar »
shaped jurisdiction. The only other jurisdiction in California which is
so bizarre is the City of San Jose, which doesn't relate to air pollution
at all.
We've been pressing for Regional Air Pollution Control Districts and
support AB 1556 in the State Legislature. We will probably come forward V
with our own parking management plan, we hope, perhaps, by the deadline f
next January 1st. The Parking Management Plan is a little microcosmic
Air Quality Management Plan (AQMP), it is single purpose perhaps, but it
sure is land use. The commercial parking business in Los Angeles is a
$2,000,000,000.00 a year business. If you just measure the surface area |
of the parking lots you're dealing with a significant percentage of the m
land in Los Angeles, let alone locational considerations or the efficiency
of traffic flows in and out of parking lots and so forth. We will
probably come forward with that. That's the direct, frontal approach.
The Bay Area Air Pollution Control District is developing its own guide- |
lines for indirect sources, since for the time being the Air Resources ^
Board seems to have set aside its indirect source review. I spoke on *
behalf of the Mayor on SB 1543 and proposals of the ARB on indirect ft
source review, and we strongly supported that. What we pointed out was
that that proposal was only to bring out an individual indirect source g
review function, and not to go the whole route as in SB 1543 which set up ^
a planning and allocation framework within which to judge individual
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projects. We pressed for the whole bit. I'd like to point out that all
of this is a real guess. My best sense is that in Los Angeles if we go
ahead it will get very hot in the kitchen, but I think we'll be sustained
in taking a fairly progressive position, and pushing for these regulations.
Other places it may not happen. It may be beaten down again. There's
something--! say this with reserve--there's something in knowing that
you're right, and in having some faith that the outcome is going to be a
positive.
There's one other aspect for planners which should be sort of
| interesting. We're finding that SCAG, the Southern California Association
m of Governments, which is a much younger equivalent of ABAC up here,
some time ago developed growth policies and adopted them. I think when
they adopted them, they were in a sort of never-never-land of going through
the paces of stating nice policiesbut it did become a plan--a policies
| plan. And now lo! and behold now that we're talking about a specific
transportation proposal, as much as 240 miles of rail rapid transit by
some peoples desire, all of a sudden we find that that is in direct
fl conflict with the growth policy dictated by the Southern California
Association of Governments. The SCAG has decided now under the transpor-
| tation bill, the Dedham Bill AB 69, that it does in fact want to be the
« Regional Agency rather than a token thing and they've all of a sudden
* gotten tough, and under law they can. It will be very interesting to see
fl what happens there. Some of the outlying counties, the equivalent say of
Contra Costa County and the City of Concord here, are very unhappy at
0 the thought that they will not be able to continue to spread in a bedroom
community fashion. In the same way, these growth projections and this
adopted growth plan, which may have been inadvertently adopted for all I
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know, are consistently working out at great variants with the individual M
community plans, even of our own City of Los Angeles. When you start
adding up each of our individual community plans you come up with an I
enormous population growth which is utterly different from what is the
official Regional plan now. That battle hasn't been joined, but somewhere £
in the midst of that battle, if there are some articulate planners who m
know what they are talking about, who know about air quality and location
and growth and so forth, the plan may be resolved rationally. I'd advise V
everyone here to keep very close touch with old laws on the books of
regional agencies and see how they might relate to your individual agency I
if they ever in fact sprang into life.
DAN LEIBERMAN: One thing that I think we would like to see planners
consider is the real cost of strategies relating to transportation. The
kind of thing I'm thinking of is a RAND Report a couple of years ago for
the San Diego area, which said that mass transit was not cost efficient
because it cost too much per pound of pollutant to change the transporta-
tion system. A later study in the San Diego area--what's called a radial
corridor study--showed that if you want a mass transit alternative, the
change in the land use would reduce sewage system costs by $500 million
in 20 years, and that the yearly reduction in 20 years of energy utiliza-
tion was about 20 per cent. So a strategy that might be carried out for
clean air should be considered in terms of the secondary social and
economic effects, and these are not always negative. In fact they may
be positive, so if you do that kind of analysis, what you come back with
is, if we want to drive the automobile, and that's the decision made,
we should not do it on the basis of considering economic implications, as
a mass transit strategy is an economic saving in the long run. Those
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are the kinds of things that we have not really considered.
The other thing is, from the ARE standpoint, when we see EIRs, and
any project which involves federal or state funds will get to the ARE for
review, we will look first for adequacy, and second, when it comes to
oxidant, whether we can put it in a regional framework. These are very
concrete things that you'll have to face when EIR's get to the ARE for
review.
Questions
What i£ an applicable implementation Plan?
JOHN WISE: Under the Clean Air Act EPA has set forth procedures for
receiving a document known as a state air implementation plan from the
state air pollution control agency, and approving that as the applicable
state implementation plan to attain the air quality standards. In the
event that parts of that plan are not approvable, then the Clean Air Act
specifies that EPA shall provide the implementation plan in its place.
Specifically, what has happened to attain the national ambient air quality
standards has required that we go beyond the traditional stationary source
controls which are, of course, listed and accepted by EPA in the state
implementation plan, and go beyond that to the consideration of mobile
sources. This has manifest itself in terms of a document known as the
transportation control plan, a plan which has been promulgated by EPA as
supplementing and actually taking the place of the state air implementation
| plan for the State of California. With that kind of background the
« applicable air implementation plan becomes the portion that has been
accepted by EPA and the portion that has been promulgated by EPA in a
total and comprehensive package. For those transportation agencies who
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wish that kind of definition, I think that in general it includes the
entire array of regulatory activities set forth by the state and approved
by EPA. Does that answer the question, Dan? I
DAN: Yes, I would point out that in raising this, the disagreement between
EPA and ARE. The ARE does not necessarily view EPAs plan as applicable "
to the state when it is not one that has been adopted by the governor.
This is one of the difficulties, and I guess the reason I want to clarify
this, is you find that all regulatory agencies are open to discussion,
and EIRs go through a very difficult path when they contain federal or
state actions. They go usually through a local air regulatory agency,
then the state, then EPA, all of which may have different views. So if you A
are in doubt, the thing to do is to interrogate the agency, and ask them
what the view of the situation is.
DAVID R. DIJULIO from the Washington Council of Governments: I have an
observation, and then a question. One is that it seems to me that we have
to recognize that the automobile provides us an essential role in our
societyit gives us something--a bit of mobility that we can't have in
any other type of system. But the other side of that coin is that if I
we're to solve air pollution and noise problems, urban run-off water
pollution problems, each of which are linked to the automobile, then
there's no way to solve the problem, even the transportation crisis that m
most of our cities have, without limiting the use of automobiles in
certain areas of the cities. I think this group ought to face that
sometime here in the next 2 or 3 days. We can talk around and around it
but we're going to have to say that we're going to limit the use of j§
automobiles. The question really is to the two gentlemen representing
the planning organization. You discussed in your remarks the problems of
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m incorporating air quality in to land use planning, but it seems to me
from my point of view that there are some advantages. Air quality has
standards based on health effects; it has the power of Congress and
regulatory authority behind it. And it can be a tool to be used by
local planners to enforce all the other sort of less quantitative regula-
« tions or ideas you have about open space, shopping and that type of
thing. I wondered if you see the benefits there? Do you see it as a
I tool to help enforce zoning regulations?
GRAHAM SMITH: I'd like to answer that from our position in L.'A. The
| Nfeyor has tried to provide leadership to make things happen, and that's
^ precisely the way he has seen it. I mentioned in that brief fast talk
~ that its hard sometimes to get our planners to pick up a book- -on city
flj time--and read about air quality and land use, just because of habit
perhaps. The Clean Air Act offers an opportunity or a lever where there
| hasn't been one before. I also believe that the lever is related to the
truth of the matter. But I'd like to point out one thing. There has
been a lot of talk about VMT reduction, and there are lots of ways to do
it. But after the parking surcharge matter, we in L.A. went through the
parking surcharge problem and the energy crisis, and we had an incredibly
severe situation in L.A. with the energy crisis simultaneously. I came
away with the distinct feeling that it would be political suicide even
for the strongest political favorite of the public in the nation to
propose a disincentive. The state went through a short period, 2 months,
under a voluntary gasoline rationing plan and in Los Angeles it was
mandatory, where we were cut some 19% over our use in the previous year.
What man or woman, if she were mayor, could possibly call for people- -
on the basis of air quality- -to go through the same inconvenience. I
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would like to advise the Mayor to call for that. The political reality
is that it would be suicidal. I'm not down on air quality, I want you
to have the sense of the strength of that lever--it's very tenuous. But I
it's something.
CONMENT: I'd like to echo that. There are some very distinct advantages |
of course, to combining land use and air quality planning. I'd like to ^
echo the political disaster that befalls anybody that tries to ration gas
for the purposes of air quality. Because I think that is going to destroy l|
EPA and destroy all of us along with it. On the other hand, there are
going to be things that we as professionals and land use planners are |
going to want to do in our communities, that will be politically inad-
visable for local city councilmen to do in the interests of air quality *
planning. We are going to need to have either ARE or EPA as support.
Now this may be the whipping boy impulse, but nevertheless it is a
valuable one and it takes the local politician off the hook in many cases,
the cases short of suicide. I don't want to minimize the political _
importance of having a state or federal grandfather insisting on certain
things that we really want to do anyway, but we haven't got the guts to
do.
COMMENT: I have an observation to make in response to a point Bill Rugg
made. I think its really a very, very important point, particularly
since we're talking about the relationship between the regulatory system
and the planning community. Bill's point, for those of you who are
writing furiously was point #5, that there is a distinct lack of local
input into regulatory rule making. What I want to indicate is that EPA
as a federal agency is particularly sensitive to this. We recognize the
validity in the charge. But there must also be recognized that there are
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M some very significant procedural problems involved here. Maybe I can
just enumerate a few of them, and then try to explain what we are trying
to do to remedy this problem. Number one is that the Clean Air Act
itself, and all of its regulatory provisions, impose time schedules which
| are to say the least very very near term. Time schedules which don't
^ leave time in fact to do the proper job of involving the public in regula-
* tory rule making. But moreover, in many instances, EPA has been confronted
I with court orders which substantially accelerate that rulemaking process.
So, there's a question of timing involved. There's also a question of
national applicability of our standards, or in California, there might be
_ a question of statewide applicability, and for one single federal agency
to reach down into every single grassroots of each and every city, county,
and planning agency to solicit their views is a monumental task. What EPA
is trying to do about it is through a procedure which is in and of itself
not very efficient,.that procedure is, when we do a regulatory rule
making, that first rule making is a proposed rule making, which then
appears in the Federal Register, specifically inviting public comments.
The commenting period is variable but it is usually a period of 30 days.
Subsequently the rule making becomes final, after adjusting for all of
I the comments received. Now that's kind of a formal process for soliciting
public comment, and not many people really read the Federal Register.
But nevertheless the procedure is there for those of you diligent enough
to search it out and use it. But in the larger sense I believe that
Bill's comment is still appropriate. We need to improve the involvement
of the public within these regulatory rulemakings.
DAN LEIBERMAN: I think our time is up. I recognize from what I've heard
this morning and what I see here, that we are all faced with an evolving
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problem and I think that there are many people on different sides of the .
fence, who are struggling together to evolve a solution so that we begin
to make decisions that improve air quality without causing reactions that V
damage the position of air quality in this societal structure.
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g GENERAL ASPECTS OF AIR POLLUTION
Dario A. Levaggi
Introduction
| The addition of an air pollution element in land use planning will
have profound effect on air pollution control. The people most intimate-
ly involved in this application will obviously have had formal training
in areas other than purely technical. The intent of this short paper
will be to introduce to planners, public administrators, and the like a
rudimentary overview of air pollution with respect to sources, available
controls and the present ambient air standards. It is strongly recommend-
ed that the attached bibliography be utilized to render more detailed
information in specific areas of interest.
The Clean Air Act of 1970 has in essence mandated that a land use
planning element be introduced into.air pollution control programs. The
eventual form and implementation is at present undetermined and somewhat
in a state of flux. Considerations are being given in such areas as
indirect sources, parking regulations and regional "pollutant" allocation.
Any and/or all of these concepts are new arenas of air pollution control
which have controversial aspects, but may well hold the key to the even-
tual solving of urban air pollution problems.
Air Pollution
Air pollution has different meanings to the public at large. To
the scientist its meaning is tied to concentration levels, classes of
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chemicals and intricate meteorological patterns. To the sociologist and _
economist its meaning is tied to odor episodes, vegetation damage, re-
duced visibility and public health. Figure 1 illustrates how different B
the basic air pollution problem is for diverse areas of the world. An
already complex problem poses then added complications such as "standard- I
ized" ambient air standards for the whole country, country-wide control
of contaminant "A" etc. B
Stationary Pollutant Sources B
Stationary sources include not only industrial complexes but also ^
domestic emissions from fireplaces, heating, cooking, etc. Additional
point sources include community waste disposal facilities and agricul- B
tural waste disposal in the form of open burning of diseased crops and
stubble destruction by incineration. |
The following is a brief description of source inventories for the _
four major pollutant classes from stationary sources: *
Sulfur Dioxide: this gaseous pollutant accounts for the B
greatest tonnage release of any contaminant, and has a long
and infamous history. The London crisis of 1952 and the Donora I
Pennsylvania incident of 1948 accounted for some 4,000 deaths
above the normal rate. Sweden in recent years has complained
that its northern lakes are increasing in acidity due to
transport of acidic sulfur compounds originating from the
industrial complexes of Germany and Great Britain. Air
pollution knows not of national boundaries!
Major sources of sulfur dioxide occur from the burning of
fossil fuels such as coals and heavy oils, both of which I
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Nomenclature
Location
Major Pollutants
TYPES OF AREA WIDE AIR POLLUTION
CD
Photochemical
California
0 (.1 - .6 ppm)
Relative Humidity
Chem. Characteristics
Health Effects
Meteorology
Season
(2)
Classical
East. USA-Europe
S02 (.2 - 1.0 ppm)
Part, (visible Reduction) Part. (300-1000 ugm/m )
Low High
Oxid. Atmos. Reduc. Atmos.
Mildly Acidic Highly Acidic
Yes Yes
Calm-Inversion Calm-Inversion
Summer Winter
Figure 1
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normally contain from .5-5% sulfur by weight. On combustion the «
primarily organic bound sulfur is converted to gaseous sulfur
dioxide. These fuels are burned to generate electrical power, run
industrial boilers, propel ships and heat homes and apartments.
Figure 2 shows emission data for the San Francisco Bay Area which |
is typical of a west coast urban area not burning oil or coal but _
rather natural gas as a primary fuel. An eastern city such as
Boston, New York or Chicago would have a distribution considerably I
different, some 50% or more of the emissions being from power
generation facilities. Additionally the tonnage emissions are
very much greater in these eastern urban areas. _
Great strides have taken place in recent years for sulfur
dioxide control. Abatement devices are now available for |
the petro- chemical industry as well as for power generation «
plants. Though expensive ($158,000,000 for the Four Corners
Power Generation Plan) these control units are slowly being I
installed country-wide due to regulations being promulgated and
the general milieu of the time. The devices employed are |
called "scrubbers", basically units causing contact between _
the gaseous emissions and either wet or dry chemicals
causing reactions to take place ridding the exit gas of its B
contained sulfur dioxide.
Oxides of Nitrogen and Carbon Monoxide: Both these contaminant
gases are the result of combustion processes. Their distribution
in a typical urban area is shown in Figure 3. It is readily
seen that both may be considered mainly due to vehicular
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BAY AREA AIR POLLUTION CONTROL DISTRICT, 1972
DISTRIBUTION OF EMISSIONS - S02
Motor Vehicles 6%
Petroleum Refinery
Miscellaneous \ 32%
16%
Chemical, Food Industry 46%
PARTICULATES
1.
2.
3.
4.
5.
6.
Motor Vehicles
Chem. & Food Industry
Metallurgical Industry
Petroleum Refinery
Aircraft
General Combustion
24%
22%
18%
7%
7%
22%
Figure 2.
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Figure 3.
BAY AREA AIR POLLUTION CONTROL DISTRICT 1972
DISTRIBUTION OF EMISSIONS
NO.
Combustion 21% / Other
Motor Vehicles 68%
CO
Motor Vehicles 93%
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« activity, overwhelmingly so in the case of carbon monoxide.
These pie distributions are of the Bay Area but the distributions
I would hold with little change for any urban industrial city
in the nation.
Control equipment for stationary sources for these pollutants
is nonexistent at this time. There are process changes now
taking place in power plants which reduce the output of nitrogen
| oxides, however, this reduction is only in the order of 301.
M For carbon monoxide all that can be stated is that the more
complete combustion is, the lower the levels of emission.
Since, however, only 1% of all the carbon monoxide is non-
vehicular in origin its abatement at stationary sources is of
| little concern. The oxides of nitrogen are of particular
« importance due to their participation in the photochemical
process. This is the major problem on the west coast, the
fl end result being the formation of ozone, nitrogen dioxide
and aerosals. Eye irritation, haze formation and vegetation
I-
damage are some of the end effects to the public of this
_ photochemical phenomena commonly called "smog".
Hydrocarbons: the stationary sources of hydrocarbon gases
| are varied and include as major emission points gasoline
marketing, degreasing operations, petroleum refining,
incineration, printing, and dry cleaning. Figure 4 shows
a national as well as a Bay Area emission distribution.
^ain, as in the case of nitrogen oxides and carbon
| monoxide we see that vehicular activity predominates and
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Organic Solvents
10%
Miscellaneous
21%
Industrial 15%
Gasoline Marketing 4%
Transportation 50%
. NATIONAL EMISSION OF HYDROCARBONS (1968)
Gasoline Marketing 3%
Miscellaneous 36%
Organic Solvents 8%
Transportation 53%
116
BAY AREA AIR POLLUTION CONTROL DISTRICT, 1972
Figure 4.
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_ accounts for approximately 50% of the total emissions.
The importance of hydrocarbon emission is their participation,
V along with oxides of nitrogen in the presence of sunshine to
trigger the photochemical sequence previously described.
The hydrocarbon classes which partake in this reaction to the
greater extent are the olefin and substituted aromatics
portions. Regional and state controls of hydrocarbon
0 stationary sources are now becoming more numerous throughout
« the country. The pioneering efforts in hydrocarbon control
and regulation began in California many years ago due to the
fl high ambient air ozone concentrations in the state, a
precursor of which are the hydrocarbons.
The abatement of hydrocarbons may be accomplished by any of
the following techniques; incineration, reformulation of
solvents, condensation processes, floating roofs for storage
| tanks and carbon absorption. In addition new developments
j and regulations are in process in many localities for the
control of vehicle tank fillings and underground gasoline
storage tanks.
Mobile Pollutant Sources
Transportation sources, essentially the automobiles, contribute
the greatest amounts of carbon monoxide (93%), nitrogen oxides (681)
and hydrocarbons (501+) to the atmosphere. Of all the major primary
gaseous contaminants only sulfur dioxide is not associated in a major
way with the automobile. What makes these auto emissions so important
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aside from the sheer quantities involved are: 1) their low level «
emission points, 2) their containing both oxides of nitrogen and *
hydrocarbons for the photochemical process and 3) the extremely high 8
local carbon monoxide levels which may occur.
Control of the automobile was started in the State of California in |
1966. Figure 5shows in detail the history of the automotive control _
programs up to the present time. All 1975 models will contain catalytic
devices which will further reduce hydrocarbon emissions greatly, as well
as carbon monoxide. These automobiles will use only lead-free gasoline
as lead can "poison" the catalyst rendering it ineffective.
I
Ambient Air Standards
Figure 6 shows the national ambient air standards (AAS) promulgated by
the EPA compared with the State of California Standards. The ultimate |
aim of the Clean Air Act is of course for the entire nation to have at «
least this quality of air in all urban areas. These ASS were arrived at
by numerous committees, hearings, and investigations and are all based on I
health effects. It should be borne in mind that these standards are
intended to protect the most susceptible portions of the public, not the jj
average healthy individual, and may therefore in general be considered
conservative.
To say the least these AAS have been controversial, some saying
they are too stringent, others that they are too lenient. The medical
evidence is on close examination found to be voluminous but contradictory.
A recent meeting convened by the National Research Council's Assembly of
Life Sciences on the status of knowledge of health effects of air
pollution left these tentative conclusions: 1) due to limits of present
118
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1
1
I^V
1
1
1
1
1
1
IHV
1
I
1
1
AXI lulletin Figure 5 March-April, 1972
New vehicle standards summary
Increasingly stringent emission standards for new ve- The summary of regulations is printed below :
hides sold in California have been imposed by State and
Federal law.
Light-duty Vehktos uncWr 6,OOO Ibs.
YEAR
Prior to
controls
1966-1967
1968-1969
1970
1971
1972
1973
1974
1975
1976
STANDARD
State
State &
Federal
State &
Federal
State
Federal
State
Federal
State
Federal
State
Federal
State
Federal
State
Federal
COLD START
TEST
7 -mode
7 -mode
50-100 CID
101-140 CID
over 140 CID
7 -mode
7 -mode
7 -mode
7 -mode
or
CVS-1
CVS-1
CVS-1
CVS-1
CVS-1
CVS-1
CVS-1
CVS-2
CVS-1
CVS-2
HYDROCARBONS
850 ppm
(11 gm/mi)
275 ppm
410 ppm
350 ppm
275 ppm
2.2 gm/mi
2.2 gm/mi
2.2 gm/mi
1.5 gm/mi
3.2 gm/mi
3.4 gm/mi
3.2 gm/mi
3.4 gm/mi
3.2 gm/mi
3.4 gm/mi
1 gm/mi
0.41 gm/mi
1 gm/mi
0.41 gm/mi
CARBON
MONOXIDE
OXIDES OF
NITROGEN
3,A7, 1000 ppm
(80 gm/wi,
1.57.
2.37.
2.07.
1.57.
23 gm/mi
23 gm/mi
23 gm/mi
23 gm/mi
39 gm/mi
39 gm/mi
39 gm/mi
39 gm/mi
39 gm/mi
39 gm/mi
24 gm/mi
3.4 gm/mi
24 gm/mi
3.4 gm/mi
(4 gm/mi)
no std.
no std.
no std.
no std.
no std.
4 gm/mi
-
3 gm/mi
*3.2 gm/mi
*
3 gm/mi
3 gm/mi
2 gm/mi
3 gm/mi
1 . 5 gm/mi
3 gm/mi
1 . 5 gm/mi
0.4 gm/mi
ppm parts per million concentration
gm/mi grams per mile
7 -mode is a 137 second driving cycle test.
CVS-1 is a Constant Volume Sample cold start test.
CVS-2 is a Constant Volume Sample cold start test average with a
Constant Volume Sample hot start test, both with the Federal,
22 minute driving cycle.
The values in parentheses are approximately equivalent values.
* hot seven-mode
119
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_ knowledge, it is impossible at this time to establish an ambient air
concentration of any pollutant--other than zero--below which it is certain
that no human beings will be adversely affected, 2) evidence suggests
that the reaction products of a mixture of pollutants may be more
significant in impairing health than any primary pollutant alone.
The health effects associated with ozone, sulfur dioxide and nitro-
m gen dioxide are, from epidemiological studies, due to irritations and
aggravations to the upper respiratory tract. These effects are more
pronounced for persons having histories of chronic asthma, bronchitis
and general respiratory illnesses. The carbon monoxide standard is to
protect persons with cardiac disease and maintain a level of 2% carboxy-
I
I
I
hemoglobin or less in individuals. High continuous levels of carbon
monoxide may dull senses, cause dizziness and nausea.
Conclusion
I concur with the opinion held by many, that the eventual
attainment and maintenance of the Ambient Air Standards cannot be
accomplished without sound land use and transportation planning.
I Stationary and mobile controls are well on the way. The elements now
missing in our control program are the formentioned ones of land use
and transportation planning. On close examination one finds that many
of the problems now faced in air pollution are the sins of the past
regarding land use and lack of mass transit systems.
The road to be hoed will be a difficult one, for these elements
are those which affect the general public in a most intimate and
economic way, and may well-result in a change in today's life styles.
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BIBLIOGRAPHY
London, 1962.
I
I
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Air Pollution, Stern, Vol. I § II, Academic Press, New York and
Air Pollution Control Guidebook for Management, edited by A. T.
Rossano, Jr., BRA Inc., Stamford, Conn. 1969.
Air Pollution Handbook, Magill, Holden § Ackley, McGraw-Hill Book
Co., New York, 1956._
Proceedings of the Conference on Health Effects of Air Pollutants.
NAS-NRC October 3-5, 1973, United States Senate Serial No. 93-15, United
States Government Printing Office, Washington, B.C. 20402. I
The Clean Air Act, December, 1970, Environmental Protection Agency,
Washington, B.C.
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I
THE ROLE OF METEOROLOGY IN AIR QUALITY
1
I
I
Richard H. Thuillier
Introduction
The quality of the air we breathe depends primarily upon two factors:
the type and amount of pollutants emitted from the source complex and the
M
extent to which these pollutants are dispersed in the atmospheric medium.
The former is at least partially under the control of man (nature is also
a source of pollution) while the latter is almost entirely beyond his
| control. Before one can assess the impact of a pollutant emitting source,
_ whether it be a stack, a road, a shopping center or a regional transpor-
tation system, an understanding of the role of atmospheric processes
(meteorology) in dispersing pollutants is required.
Weather Systems and Pollutant Episodes
If we consult the weather section of the daily newspaper, we will
usually find a weather "map" which indicates the distribution across the
country of "highs", "lows", and "fronts". These features are indicative
| of motions induced in the atmospheric fluid by the sun's heating of the
rough and varied surface of the rotating earth. The weather map, by
indicating the patterns of barometric pressure observed at least four
I times each day by a network of stations, provides, as it were, a snapshot
of the disturbed fluid at a particular time of a particular day. If we
| were to examine the weather maps in successive editions of the newspaper,
we would notice that each successive weather map is different from the
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one before and that certain identifiable features may be seen to move _
along well defined paths from one location to another. A closer look
at the individual weather maps will reveal that associated with certain
of the map features we have just described are areas with greatly varying
weather such as clear and cloudy areas, calm and windy areas, quiet and 'f
stormy areas. Such an examination will also reveal that the direction _
of the wind is closely associated with the moving map features. Since
the dispersing capacity of the atmosphere responds to the type of weather
existing at a given place and a given time, we would expect, and do in
fact'find a great variability in the day to day quality of the air we
breathe, even with little or no variability in the rate of emission of
pollutants from sources. The variability in weather patterns and
associated dispersion of pollutants brings us an occasional episode of
several days duration characterized by especially poor air quality,
underscored by reduced visibility and a distasteful discoloration of the
air. The same variability provides those sparkingly clear days which
belie the relentless emission of pollutants from myriad sources. By
studying directly the statistical distribution of weather conditions in
an area or at a site (climatology) or indirectly the statistical distri-
bution of pollutant concentration values (parts per million) measured
by air monitoring stations, the potential or tendency for the development
of pollution episodes may be assessed. This potential will vary from
place to place and should be of concern to anyone engaged in planning m
land use or transportation.
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Weather Elements and Pollutant Dispersion
I
The specific way in which the weather features discussed above
affect the dispersion of pollutants is by affecting locally or regionally
the characteristics of certain weather elements which are in turn directly
m involved in the pollutant dispersion process. Of these, the most funda-
mental are the characteristics of air flow and temperature structure.
Air flow characteristics: The direction of air flow is very
important from an air pollution standpoint, since it determines the
location of receptors relative to the location of sources. Wind direction
depends, in a gross sense, upon the orientation of the isobars or lines
of equal barometric pressure which delineate the lows and highs on the
B weather map. It is also influenced to a considerable extent by the
presence of topographical features and man-made structures. Topographical
features such as canyon walls, valley floors and bodies of water can be
heated (by day) or cooled (by night) in a horizontally non-uniform
manner due to different surface and slope characteristics, giving rise
I to local air circulations such as sea breezes and valley winds. Air flow
can also be channeled around obstructions such as ranges of hills or
large structures. Consequently, wind direction in hilly or mountainous
I terrain or in urban street canyons may be quite different from that which
is indicated by a weather map or the data taken at an airport in nearby
but locally flat terrain.
H In extensively flat areas such as the central plains of the United
States, wind direction information from a single airport station may be
V quite representative of hundreds or even thousands of square miles
surrounding the station. In topographically complex areas, however,
| stations farther away from a site than the nearest hill may not be
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representative. Another characteristic of wind direction in complex
terrain is a large diurnal (during the day) variability. Local circula-
tions such as sea breezes or valley winds will cause different and
frequently opposite directions to occur at different times of the day.
I
In such situations, separate wind roses should be prepared for different m
times of the day as well as the standard rose for all hours. While wind
roses are useful for indicating the relative frequency of various wind
directions, it should be borne in mind that for short periods of time, I
the wind can come from any direction. For this reason, wind direction
characteristics of a site may be of little importance in assessing air f|
quality impact of a source relative to a standard which is not to be m*
1
exceeded more than one hour per year.
The other important characteristic of air flow is the wind speed. I
While sources emit pollutants at a fairly constant rate, the speed with
which a volume of air passes a source will determine the quantity of |
pollutant the volume receives from the source. Since the concentration »
or quantity of pollutant per unit volume of air, rather than the rate
of emission from the source, is of importance in determining the quality I
of the air, wind speed and the associated dilution of pollutants at the
source is an important meteorological parameter. In addition to the
mechanism just described, wind speed has an indirect effect upon dilution
by aiding in the production of turbulence in the air. As a general rule, ."
turbulence will increase with an increase in the speed of airflow over
the ground. Since increased turbulence leads to increased dilution of
pollutants by mixing with cleaner air, wind speed is indirectly V
associated with this dilution.
I
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Temperature structure and atmospheric stability: Due to the
I
differential heating and cooling of the earth's surface as mentioned
above and due, also, to vertical and horizontal movements of air in
various layers above the surface, air temperature will vary both
P horizontally and vertically. When large temperature differences occur
horizontally, as mentioned earlier, local air circulations will sometimes
occur. Large temperature differences in the vertical will affect the
I development of turbulence and vertical circulations which are necessary
for effective dilution of pollutants from surface sources by mixing with
| the cleaner air above. In this section we will discuss the relationship
§ between vertical temperature structure and air quality.
On an averaged basis, all over the globe and in the first few miles
above the surface, temperature decreases with altitude at the rate of
several (usually no more than about five and one-half) degrees Fahrenheit
| per thousand feet. There are a number of processes, however, that can
_ cause the temperature structure to differ, at a given place and time,
from the average condition. Strong heating of the surface of the earth
tt on a hot summer day will cause the air in contact with the ground to
reach high temperatures. If the rate of heating near the ground is
M faster than the rate at which the heat can be transferred to the air
_ higher up, a temperature change of more than five and one-half degrees
* Fahrenheit per thousand feet may occur near the ground. If the ground
is cooled instead of heated, smaller decreases or even increases in
temperature with altitude may occur. Departures may occur within
discreet layers at any altitude due to different directions of transport
at different altitudes. Thus cool marine air may be transported in the
» lower layers to a site onshore by the action of the Seabreeze while the
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upper layers remain warm on offshore winds. Finally, air which descends
I
from higher to lower altitudes can be heated by compression since atmos-
pheric pressure increases as the surface of the earth is approached. .
The rate with which temperature increases or decreases with altitude
has a lot to do with the development of atmospheric turbulence which is 9
necessary for dilution of pollutants in the air by mixing. When the .
temperature in a layer of air decreases rapidly with altitude, turbulence
can develop readily and we say that the layer is unstable. When the
decrease with altitude is slight or when an increase in temperature with
altitude occurs, we say that the layer is stable, since the development
of turbulence is inhibited in such cases. Layers in which the temperature
increases with altitude are termed inversion layers. Inversion layers
are very stable and the development of turbulent conditions in such layers m
is difficult. Consequently, inversion layers are characterized by a
|
very slow rate of mixing. If a plane or cloud of pollutant gas is
emitted into an inversion layer, it will mix very slowly with the m
surrounding cleaner air and stay fairly concentrated for a long distance
downwind of the source. If a plume or cloud of pollutant gas is emitted
into an unstable layer adjoining the inversion layer, the gas will be
readily mixed by turbulence in the unstable layer but will not readily 0
mix into the inversion layer the boundaries of which act as barriers to a
the vertical transport of pollutants.
It is quite common in most parts of the world, over the land areas, V
for stable layers to form near the surface as the result of night-time
cooling of the ground in conjunction with one or more of the other J
processes described earlier. Such a stable layer, or possibly even an ^
inversion layer, may extend several thousands of feet above the ground.
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Heating of the ground (by day) or air flow over the rough surface at any
time will usually result in the formation of unstable conditions in the
air immediately adjacent to the ground. In such situations, when unstable
air next to the ground is overlain by more stable air above, pollutants
P emitted at ground level will be mixed in the unstable air near the
M- ground. The mixing will continue until the pollutants are distributed
vertically throughout the unstable layer, but mixing will not proceed
into the more stable air above, the base of which acts as a lid. The
boundary between the stable and unstable layers is called the mixing
J height and varies in both space and time. The mixing height is usually
m greatest in the mid afternoon (several thousand feet) when the surface
I
heating and wind speeds are greatest and least in the early morning
flt (several hundred feet or near zero) when surface cooling and wind speeds
are least.
Information on temperature structure in the vertical is obtained
by sending up balloons equipped with radio transmitters. As the balloon
ascends, information on the temperature structure is transmitted to a
receiver on the ground. Statistics on the mixing height characteristics
of an area may be obtained from such balloon sounding (radiosonde) data,
but as in 'the case of the winds, care should be exercised in extrapolating
such data throughout complex terrain.
Visibility and Air Quality Awareness
I One of the most pervasive and persistent indicators of the presence
_ of air pollution is reduced visibility. During pollution episodes, our
* treasured views of mountain and sky are partially or totally obscured
due to the scattering or absorption of light by the particles in the
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polluted air. The same optical properties of the particles, and certain
I
gases, give rise to a distasteful coloration of the air. If the air were
completely free of particles, scattering by the air molecules alone would
reduce visibility to about 150 miles. When particles are present,
visibility may be reduced to a couple of miles and fog droplets, of course, 9
can reduce visibility to near zero. As it turns out, the amount of light '
scattering by particles in the air is very highly dependent upon the size
of the scattering particles as well as the number of particles present.
Particles in the size range from one-tenth to one micron (millionth of a
scatter less efficiently. When the relative humidity exceeds 70 percent, M
many types of pollutant particles take on water to form droplets which
are larger in size than the original particles. This process can m
frequently enhance the reduction of visibility when small particles grow
to the optimum scattering size. As with all pollutants, the concentra- f
tion of particulate matter in the air will increase under conditions of «
light wind and a stable temperature structure. The increase in particle
concentration may lead to visibility reduction in and of itself, but high
humidity may be an added weather element of concern. In any event, the
formation of water droplets in the form of fog or haze is always indica- £
tive of the presence of particles in the air. In regions with frequent _
incidence of high relative humidity, the aesthetic impact of air pollution
in the form of visibility reduction will usually be more severe than is fl
the case in the drier regions.
Conclusion
As we have seen in the foregoing discussion, weather elements play
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£ an important role in determining the impact of a given air pollutant
emission. When analyzing air quality impact, care should be given to
obtain meteorological information for the site or area of concern and a
professional meteorologist should be consulted in complex situations.
It would be well for those engaged in air quality impact analysis on a
continuing basis to collect and maintain a library of meteorological
, and climatological data for their areas of concern, as a ready reference.
Sources of such information include the National Weather Service, Air
Force, Navy, and some Army bases, air pollution control agencies,
universities and colleges and industrial plants, sewage treatment plants
and others. A centralized source of weather information from all over
the country is the National Climatic Center, Federal Building,
Asheville, North Carolina.
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Warren B. Johnson, Jr. and Richard H. Thuillier
I
I
I THE STATE OF THE ART IN AIR QUALITY MODELING
I
Introduction
Before proceeding with an exposition of the state of the art in air
quality modeling, it will be worthwhile to define the terms "modeling"
and "state of the art" and to say a few words about the development of the
| current need for air quality models.
I Air quality depends, quite simply, upon the degree to which our air
is contaminated by harmful substances. Such substances are emitted from
a great variety of sources and mixed with the air. Once the contaminant
leaves the source, it is subject over time to increasing dilution as the
m process of mixing continues. As dilution increases, the degree of
M contamination decreases and the quality of the air improves. The more
* highly the parcel is contaminated at the source, the less effective will
I be the dilution upon the quality of the air. The more sources which
contribute to the contamination of the parcel as it moves along, the
poorer will be the quality of air in the parcel. Finally, the more
vigorous the mixing, the greater the dilution and the better the air
~ quality for a given amount of source contamination.
All of these things are somewhat obvious to us in a qualitative and
general sense, but when the source structure and the meteorological
m conditions become complex, intuition fails and a formal, systematic
procedure is required to establish a meaningful relationship between
I
source emissions and air quality through the intervening action of
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meteorological dilution. Such a procedure is referred to as an air «
quality model.
The degree to which we may formalize the intricate relationships
involved in air quality depends upon our knowledge of the existence and
nature of contaminant sources and the atmospheric processes involved in |
mixing contaminants with and removing them from the air. The rapidity «
and thoroughness with which we can handle analyses involving vast source *
complexes and intricate meteorological interactions depends upon the V
development of efficient data processing facilities and analysis methods.
Finally, the ability of the user to comprehend and utilize modeling jj
techniques and incorporate them in the decision making process depends m
upon the user's technical and fiscal resources and the credibility of *
the modeling process itself. All of these considerations are intimately Ij
involved in determining the state of the art of air quality modeling.
In the early days of air quality control, little need existed for 1
a formalized approach to air quality evaluation. Technological reduction
of emissions at the source of curtailment of certain source operations
was a direct and cost-effective method of effecting substantial improvement
in air quality. The recent introduction of comprehensive and quantitative
air quality standards, however, coupled with a rapid increase in the
number of sources, has given rise to a need for far greater control than
had heretofore been envisioned or achieved. Control costs have increased
tremendously as has the political sensitivity of many control decisions. 1|
Control effectiveness must therefore be carefully and accurately evaluated
and the need for formalized air quality modeling is obvious.
1
134 m
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Air Quality Modeling in the Decision Makingj'rocess
There are two principal uses to which air quality models may be put.
H The first of these is to serve as tools for research in gaining a better
understanding of the processes involved in the determination of air
quality. The second is to serve as tools to aid the decision maker in the
_ day to day effort to hold the line on air quality degradation and in
planning for the eventual attainment and maintenance of air quality
IB standards.
In view of the symposium's orientation toward the latter use of
modeling, it will be worthwhile to discuss the context or framework of
the decision making process vis a vis the use of air quality modeling
as outlined in Figure 1. In this context, the specific relationship
between emissions and air quality, involving the processes of meteorology,
will be referred to as an air quality "simulation" model (AQSM) in order
to distinguish it from the more general framework which itself may be
thought of as an air quality model of broader context.
When used by itself, the AQSM provides information on a relative
m though quantitative scale. We may relate conditions of source configura-
tion and meteorology to greater or lesser levels of contamination but we
cannot attach any objective significance to those levels. Decision
making is better served when the results of the AQSM are coupled with a
| set of standards against which one can objectively gauge significance.
«| Such standards exist today as promulgated by federal and state government,
based directly on health, biological, materials and aesthetic effects.
If the direct effects of contamination levels, as embodied in the
standards, were the only item of concern, effective decision making
B could proceed at this point. This is frequently the case with single
135
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_ purpose air pollution control agencies and single purpose legislation
such as the Clean Air Act. Realities, however, require that social,
I
economic and political considerations be included.
IB Bas i c Modeling Approaches
As mentioned above, the process of air quality modeling is simply a
formal, systematic procedure for relating source emissions to air quality.
Historically, this procedure has involved a_ priori approaches based on
|| mathematical physics or the statistical theory of turbulence, a_ posteriori
M approaches based on empirical relationships deduced from an analysis of
observed data, or a combination of the two approaches. When reviewing the
literature, it soon becomes evident that there are just about as many
models as there are individuals who are inclined to model. Excellent and
P detailed summarizations, analyses and bibliographies relating to the gamut
of research in air quality modeling are presented by Sutton (1933),
* Pasquill (1962), Moses (1969), Stern (1970), Eschenroeder et al (1972),
Dodge (1972) and Seinfeld et al (1973). All of the modeling approaches
described in these reports are reasonable methods for arriving at the
relationship between the emission rate of contaminants and resultant air
quality. The choice of any one approach depends primarily upon the qual-
ity of the input data, the fiscal and technical resources of the user and
IB the nature of the problem to be solved. We shall not devote time to
each of the modeling approaches described in the aforementioned summaries
. but will treat, rather, the basic classes of models with specific
references to some typical and widely accepted examples.
I
_ 137
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I
Boundary layer models : The most generalized and sophisticated class .
of models is based on the physical principle of conservation of mass
applied to the turbulent layer of air near the surface of the earth. A I
mathematical equation which may be written in the form of equation (1)
describes the balance of physical processes that must be satisfied under
the assumption of pollutant mass conservation. In equation (1)
v
138
_
H
which is usually referred to as the diffusion equation, C is the concen- m
tration (mass per unit volume) of a given contaminant in the air. The
first term on the left represents the rate of change of concentration with
time; the second term represents the transport of contaminated air by
the three components of the rne^n wind (advection) ; the first term to the |
right of the equal sign represents the transport of contaminated air by &
turbulent motion (diffusion) and the last two terms represent respectively
the changes in contaminant concentration due to chemical reactions in the I
air and the changes due to the contributions from sources and the removal
by processes such as deposition and rainout. The equation is valid at |
a given point in space (x,y.z) and time (t) . The quantities K, and K
are related to the scale and intensity of turbulence and are derived from *
the statistical and dimensional theory of turbulence in the boundary V
layer. The form in which equation (1) appears is termed "Eulerian" which
means that the equation is solved for a fixed point in space as the air £
flows by. _
The usual method of solution of equation (1) is by the technique of *
numerical integration in which the derivatives, which are instantaneous
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rates of change at a point, are replaced by finite differences, which are
average rates of change between two points. The points between which the
finite differences are evaluated are arranged on a uniformly spaced grid
covering the geographical area in which air quality is to be modeled and
m the contaminant concentrations are evaluated at discrete points in time
at each of the geographical grid points. Since the equation involves only
rates of change in concentration with time, concentration values must be
M provided at each grid point for some initial (starting) time. A high
speed computer is used to do the "bookkeeping" involved in keeping track
| of the many interacting processes taking place on the grid.
^ An alternative approach to the "Eulerian" is the so called "Lagrangian"
approach. In this approach, concentration changes are calculated within
V a specified parcel of air as it travels along in the flow of air. The
form of the equation is essentially the same as equation (1) except that
P the advection term is absent. Strictly speaking, the Lagrangian approach
involves the statistics of the displacements of contaminated parcels in a
* turbulent flow field along with the mass balance associated with each
Ij parcel. In practice, parcels are followed along mean wind trajectories.
Advantages: The boundary layer approach, since it involves physical,
| deterministic modeling, is potentially the most general of all modeling
techniques. Since the diffusion equation is prognostic in form, containing
* the time derivative of concentration, the approach is applicable to time
V dependent input such as changing meteorological conditions in evolving air
pollution episode situations. Since the rate equations for chemical
I transformation are similar in form, chemical transformations of pollutant
species may be handled in conjunction with advective and turbulent trans-
port to produce a comprehensive transport and air chemistry model. Finally
^ 139
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I
since advective and turbulent transport are contained in separate terms
of the equation, the approach can readily handle the light and variable
or even the calm conditions of air motion associated with severe pollu- I
tion episodes.
Disadvantages: The principal disadvantages to the use of boundary g
layer modeling is one of cost. In order to achieve any useful degree of «
resolution in space or time, the iterative schemes for solution of the *
equation in its most general form require large amounts of computer time V
and core storage. Use of such models is usually limited to agencies with
substantial computational facilities. Even with the availability of such J
facilities, the use of such models for routine operational purposes or ^
for climatological studies involving large numbers of component meteoro-
logical regimes is largely precluded by factors of cost. Finally, it IT
should be noted that the accuracy implied in the solution of the
physically based diffusion equation can, in reality, be greatly diluted I
by virtue of the approximate nature of the numerical integration and the
high degree of parameterization required to facilitate a solution
particularly in the case of sparse or inadequate input data. }
Among the examples of boundary layer models we might mention the
models of Lamb (1969), Shir and Shieh (1973), MacCracken (1971),
Eschenroeder and Martinez (1971), Wayne et: al. (1971), and Sklarew
et^ al. (1972). The first three of these are Eulerian grid models, the 9
next two are Lagrangian trajectory models and the last is a hybrid form
known as a "particle-in-cell" model which involves the movement of dis-
crete particles, representing given masses of contaminant, through an
Eulerian grid. Each of the above models handles the modeling problem in
a slightly different way with differing advantages and disadvantages. V
140
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I
tt Most o£ them are equipped to handle the full range of reactive and
non-reactive species of contaminant.
I Chemical sub-models: As mentioned earlier, the boundary layer
models are capable of addressing the problem of chemical reactions in
the atmosphere. When used for this purpose, a sub-model based on the
theory of chemical kinetics is involved. Large numbers of chemical
reactions are involved in the transformation of contaminant species which
takes place in the atmosphere. Chemical kinetics schemes have been
. devised to account for varying numbers of these reactions as indicated in
i Figures 2 and 3. Rate constants for the various reactions are varied
within their respective ranges of uncertainty and schemes for lumping
similar classes of reacting species are devised with a view toward
simulating the atmospheric chemistry as closely as possible with the
least number of reaction steps. Almost all of the verification studies
for the kinetic sub-models are conducted by comparing the predictions of
m the model with results obtained by combining contaminants in a laboratory
as indicated in Figure 4 for reaction chamber studies but little has
been done to validate such schemes in the real atmosphere due to the almost
insurmountable complexities involved in such experiments.
m Gaussian models: Probably the most widely used of the various
» modeling approaches is the so called Gaussian plume model. This model
assumes that the contaminant plume from a single point source is
characterized by a normal (Gaussian) distribution of contaminant
concentration about the plume centerline. The spread of the plume with
| distance downwind of the source is represented by treating the standard
deviation of the concentration distribution as an increasing function of
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downwind distance. The algorithm for the Gaussian model takes the
generalized form:
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where C is contaminant concentration; H is the height of the plume above
the ground; u is the wind speed, a and a are the horizontal and verti-
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_ cal standard deviations, respectively of the Gaussian distribution; y and
z are, respectively the vertical and crosswind distances from the plume
centerline; and e is the base of the natural logarithms. Figure 5 gives
a schematic presentation of the spreading plume from an automotive line
source and Figure 6 gives a definition of the variation of standard
deviation (vertical) with distance for various meteorological conditions
on the basis of empirical studies.
Advantages: The principal advantage of the Gaussian approach is
the relative simplicity of the modeling algorithm. Properties of the
I normal distribution have been extensively documented and the solution of
the algorithm as a function of space is straightforward. Fjctensive field
investigations have provided considerable data on the concentration
« standard deviation as a function of downwind distance and broad classes
of meteorological conditions. The model can readily be extended to two
and three dimensional source configurations by spacial integration of the
point source algorithm. Multiple sources can be handled by superposition
| of point source plumes. Finally, due to the simplicity of the algorithm
«l and its algebraic nature, the Gaussian models are very inexpensive to
implement, may be run on desk calculators or by hand and are easily
reduced to nomographic solution form.
1
145
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I
Disadvantages: The principal disadvantage of Gaussian models is jft
the requisite assumption of "steady state" meteorological conditions.
These conditions must prevail for a minimum time period on the order of I
ten minutes to one hour and up to a time period equal to the furthest
downwind distance of concern divided by the wind speed. Curvature of the
plume centerline cannot readily be handled. Since most of the empirical ||
data on plume concentration standard deviation has been obtained at
locations characterized by relatively flat terrain, use of the models is
usually restricted to similarly flat terrain locations. The form of the
Gaussian algorithm itself presents a problem since wind speed in the
denominator can not approach zero too closely without causing unreasonable M
results. Therefore, the model is not applicable in calm or very light
wind situations. Finally, the method of plume superposition does not I
lend itself to the consideration of chemical reaction between contami-
nants from different sources. Some of these disadvantages, specifically 9
those associated with steady state requirements and light wind conditions ||
may be overcome by treating individual contaminant "puffs" in a Lagrangian
manner. The added flexibility, however, is offset by a much greater
computational burden.
Among the many examples of Gaussian modeling, we may mention the |
work of Turner (1964, 1969), Miller and Holzworth (1967), Johnson, Ludwig «
and Moon (1970). The monograph of Turner (1969) is an excellent combi-
nation text and workbook which provides a thorough introduction to the
use of the Gaussian modeling technique. A simplified version of the
Gaussian model which is useful in many urban modeling situations has been I
presented by Gifford and Hanna (1973) and a number of simplified versions ^
are presented in this symposium in the paper entitled "Simplified
146
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Techniques for Air Quality Impact Analysis."
* Statistical models: In addition to the Boundary Layer and Gaussian
tt modeling techniques, which are essentially a priori techniques based on
physical relationships, there is a third class of models which relies
I primarily on a posteriori statistical relationships. This modeling
approach takes advantage of the information which is contained in
existing data sets, involving emissions and concentrations of pollutants
with or without meteorological factors.
The principal advantage in the use of statistical models lies in
their derivation from observed data, reflecting processes as they actually
took place in the atmosphere. They also lend themselves to probabilistic
assessments of air quality impact. The principal disadvantage of such
models is their inability to handle substantial changes in the amount
or geographical distribution of pollutant emissions from the situation
which pertained during the data collection. Some of the disadvantages of
both the physical and the statistical modeling techniques may be overcome
V by combining the two approaches. Thus, for example, the annual average
£ pollutant concentration in some future year might be simulated by using
a Gaussian or Boundary Layer model. Statistical techniques based on past
data might then be used to estimate the frequency with which a one-hour
air quality standard will be exceeded during the year.
Some examples of statistical modeling applications are given by
M Moses (1969), Larsen (1971), Wilting and Van den Berge (1971), and
Thuillier (1973). The simple proportional rollback approach which is
often used in impact estimations is itself a form of statistical modeling.
I
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Modeling Resolution
One of the most important factors in air quality modeling is the '
modeling resolution or the scale in space and time on which the modeling
is to operate. Some modeling applications might require the estimation
of contaminant concentrations occurring on a single street corner and I
averaged over the period of an hour while other applications might
require the annual average contaminant concentration, spatially averaged B
over an entire city. In addressing the federal and/or state air quality
standards, a large variety of averaging times from hourly to annual average
must be handled. The desired space and time resolution of the modeling
results, coupled with the space and time resolution of available input
data and the resources of the user will determine the type of model which
will be desirable or suitable for a particular analysis. Fine resolution
analyses covering extensive geographical areas and long time intervals
tend to be expensive and require considerable modeling sophistication
while coarse resolution analyses tend to be simpler and less expensive.
In any event, it is never possible to achieve a resolution finer than that 9
of the input emissions or meteorological data. Figures 7 and 8 provide f
some insights into the interrelationships among uses, users, and reso-
lution of air quality simulation models. I
Conclusions and Recommendations
The foregoing has been a brief exposition of air quality modeling
as it exists today. No attempt has been made to present the individual I
modeling techniques in detail since such would be a monumental task
out of all proportion in this symposium. The references cited at the end
of this paper and throughout the symposium provide a thorough and detailed
150
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exposition of the air quality modeling.approach and technique. These and
similar references should be carefully studied by anyone interested in
developing an air quality modeling expertise. For those of limited
technical, fiscal and computational resources, the Gaussian approach
will serve to provide useful solutions to a great many problems. Even the
simplest of modeling techniques, however, can benefit greatly from the
insights of an expert in air quality impact analysis and such a person
should be consulted whenever possible.
The presentation on this topic was made at the Symposium by Dr.
Johnson who spoke in reference to a number of slides, some of which
appear in this paper. Due to a malfunction of the taping procedure,
the transcript of Dr. Johnson's talk was lost and no written version
of the talk was available. Since a prior and protracted commitment
has prevented Dr. Johnson from writing on the subject himself, Mr.
Richard Thuillier, Conference Coordinator, lias written this paper
with Dr. Johnson's permission, using Dr. Johnson's figures.
153
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BIBLIOGRAPHY
154
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Dodge, M.C., 1972. Workshop on Mathematical Modeling of Photochemical
Smog, Summary of the Proceedings, EPA-R4-73-010.I
Eschenroeder, A.Q. and J.R. Martinez, 1971. Concepts and Applications of
Photochemical Smog Models, Tech. Memo 1
Corporation, Santa Barbara, California.
Photochemical Smog Models, Tech. Memo 1516, General"ResearchB
Eschenroeder, A.Q. , J.R. Martinez and R.A. Nordesieck, 1972. A View of
Future Problems in Air Pollution Modeling, General Research |
Corporation Technical Memo 1631, Santa Barbara, California.
Johnson, 17. B. , F. Ludwig, and A. E. Moon, 1970. Development of a Practical,
Multi-purpose, Urban Diffusion Model for Carbon Monoxide, Pro- *
ceedings of the Symposium on Multiple Source Urban Diffusion Models,
EPA/AP-86.
Lamb, R. , 1969. An Air Pollution Model for Los Angeles, Master's Thesis,
UCLA. g
Larsen, R.I., 1971. A Mathematical Model for Relating Air Quality
Measurements to Air Quality Standards, EPA/OAP Publication No. AP-89.
MacCracken, M.C., T.V. Crawford, K.R. Peterson and J.B., Knox, 1971.
Development of a Multi-Box Air Pollution Model and Initial Verifi-
cation for the San Francisco Bay Area, Lawrence Livermore Laboratory,
Preprint No. UCRL- 73348. |
Miller, M.E. and G.C. Holzworth, 1967. An Atmospheric Diffusion Model M
for Metropolitan Areas, JAPCA, Vol. 17, No. l.
Moses, H. , 1969. Mathematical Urban Air Pollution Models, Argonne National
Laboratory, Argonne, Illinois, ANL/iS-RPY-.OOl . '
Moses, H. and J.J. Roberts, 1969. Statistical Studies of Air Pollution,
Argonne National Laboratory, Argonne, Illinois.
Pasquill, F. , 1962. Atmospheric Diffusion, London, D. Van Nostrand Co.,
Ltd. _
Seinfeld, J.II. , T.A. Hecht and P.M. Roth, 1973. Existing Needs in the
Experimental and Observational Study of Atmospheric 'Chemical
Reactions , EPA-R4-73-031.
Shir and Shieh, 1973. A Generalized Urban Air Pollution Model and its
Application to the Study of SO., Distribution in the St. Louis
Metropolitan Area, IBM Research Report RJ 1227.
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Sklarew, R.C., A.J. Fabrick and J.E. Prager, 1972. A Particle in Cell
Method for Numerical Solution of the Atmospheric Diffusion
Equation, Final Report, EPA Contract No. 68-02-006.
Stern, A.C., ed., 1970. Proceedings of the Symposium on Multiple Source
Urban Diffusion Models, EPA, Research Triangle Park, North Carolina.
Sutton, O.G., 1953. Micrometeorology, McGraw Hill, New York.
Thuillier, R.1J., 1973. Air Quality Statistics in Land Use Planning
Applications, Preprint, Third Conference on Probability and
Statistics in Atmospheric Science, Boulder, Colorado, June, 1973.
Turner, B., 1964. A Diffusion Model for an Urban Area, J. Appl. Meteor.,
3 (1): 83-91.
, 1969. Workbook of Atmospheric Dispersion Estimates, U.S.
Public Health Service Publication No. 999-AP-26, Revised.
Wayne, L.G., M. Weisburd, R. Danchick, and A. Kobin, 1971. Final Report-
Development of a Simulation Model for Estimating Ground Level
Concentrations of Photochemical Pollutants, Technical Memo, Systerns
Development Corporation, Santa Monica, California.
Wilting, J.J. and H. Van Den Berge, 1971. Air Pollution Monitoring Network
in the Netherlands, Computer, Jul/Aug, 1971.
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AIR POLLUTION EMISSIONS AND EMISSION FACTORS
Howard Harawitz
Introduction
This paper will describe how to estimate the quantity of pollutants
emitted into the atmosphere as a result of community development. Together
with meteorological data these quantitative estimates of pollutant
emiss-ions serve as the input to air pollution models which are used to
predict the effect of development on air quality. The models take
» emission rates from all kinds of human activities and transform those
rates into concentrations of contaminants in the atmosphere.
For example, a number representing a quantity of carbon monoxide
emitted into the atmosphere would be converted by a model into numbers
representing the concentration of carbon monoxide in the air we breathe.
The emission rate of carbon monoxide could be expressed as tons-per-day
j emitted by a source or group of sources. The model would transform the
tons-per-day figure into concentrations throughout the modeling area
expressed as parts per million.
There are many different kinds of sources of air pollutant emissions,
| including factories, power plants, dry cleaning establishments, residences,
_ motor vehicles, ships and airplanes. Some of these sources are themselves
made up of other sources of air pollution. A factory, for example may
II contain furnaces, chemical reactors, space heaters and degreasers--all of
which are emitters of air contaminants.
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Motor vehicles are a most significant and extremely complex pollution
source. There are many different kinds of motor vehicles operating in
many different modes. There are light and heavy duty trucks and cars,
with and without emission controls; there are vehicles accelerating, de-
I
celerating and cruising at steady speeds; and there are vehicles idling
in parking lots--all contributing different amounts of pollutants to the
atmosphere.
Because of these complexities it is not feasible to determine exactly
the quantities of pollutants emitted in our existing communities. If it
is not possible to determine precisely these existing emissions, how then |
are we to predict future emissions from communities that do not yet exist? ^
Fortunately, for most planning purposes exact values of these variables
are not required. Reasonable estimates, averages and approximations will I
generally provide enough information so that alternative strategies may
be compared, evaluated, and related to air quality standards so that f
decisions can be made. _
It is the purpose of this presentation to familiarize you with ideas *
and concepts as well as specific methods used in estimating air pollutant 0
emissions for planning purposes.
Pollutant Source Categories
Most agencies divide pollutant sources into the categories of
stationary and mobile sources. Stationary sources consist of power
plants, refineries, residences, and the like. Mobile sources include |
automobiles, trucks, trains, ships, and airplanes.
For convenience in the development of an emission inventory for use
in modeling, the multiplicity of different kinds of sources can be placed I
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into the following categories:
Point sources
Area sources
Line sources
Mathematically speaking, a point source is a pollutant source the
dimensions of which are negligible compared to the area being studied.
The term "point source" is most commonly used, however, to specify a
single source that emits a relatively high quantity of one or more pollu-
tants. The Bay Area Air Pollution Control District's published
m Emissions Inventory, for example, lists about 100 specific sources that
« emit at least 0.1 ton/day of any contaminant. While it is often useful
to single out substantial emitters for individual treatment, it is
usually more convenient to treat smaller sources like automobiles, houses
and small commercial units by aggregating them into area or line sources.
| An area source is a collection of small sources, stationary and/or
« mobile, distributed over some geographical area. The area source boundary
might coincide with a jurisdictional boundary, a physical boundary that
affects the dispersal of pollutants, or the lines of a convenient
geographical grid system.
g A line source is a collection of individual sources distributed
alone a single line, rather than a geographical area. The most obvious
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example of a line source is a highway or road. In this case, the indivi-
dual sources are motor vehicles.
Emission Factors and Emission Rates
An emission factor is used to compute the rate at which a pollutant
is released into the atmosphere by a source. For a given pollutant
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source, the emission rate is equal to an emission factor multiplied by A
a number expressing the level pf activity of that source. Emission
rates are expressed in units of mass per unit time, e.g., tons/year,
tons/day, kg/day, Ibs/hr, or grams/second.
For example, the emission factor for auto body incineration is 1.1
kilogram of carbon monoxide emitted per car body incinerated. (AP-42, »
2.2-1) If six car bodies per hour are incinerated and the incinerator
operates 8 hours per day, then the daily emissions can be computed as
t
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follows:
1.1 kg CO/car x 6 cars/hr x 8 hrs/day = 52.8 kg CO/day.
Emission factors for a great number of different kinds of industrial,
and other, activities like furnace operation, cement manufacturing, oil flj
refining, aircraft operations, etc. can be found in the U.S. Environmental
Protection Agency publication, Compilation of Air Pollutant Emission
Factors (AP-42). It should be pointed out that a great deal of judgment m
is required in using much of the information contained in that publication
because things like process operating conditions and emission control
devices must often be taken into account in computing emissions. However,
reference to AP-42 in conjunction with conversations with appropriate I
air pollution control agency personnel can often enable planners to m
I
obtain useful approximations.
When emission factors for mobile sources are discussed, we generally
mean emission factors for automobiles and trucks, although ships, trains,
tractors and airplanes are mobile sources too. It is just that in most I
communities the highway vehicles account for almost all the emissions
from mobile sources. (Emission Factors for motor vehicles are also
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included in the EPA publication AP-42.).
Computation of emissions from motor vehicles is complex because, as
mentioned, the pollutant emission rate from any vehicle depends on its
speed, mode of operation (that is, cruising, acceleration, deceleration),
| presence or absence of air pollution control devices, maintenance, etc.
M The situation is made even more difficult because of the great variety
of vehicles on the road and the variation in traffic conditions during almost
any given time period.
To make it possible for air pollution control districts, planners,
g| developers and other interested parties to estimate emissions from motor
vehicles, the EPA (and other agencies) have computed average emission
* factors. These are factors based upon statistical data for the average
mix of vehicles on the streets and roads of the United States in a given
year. They take into account mileage, emission control devices, deteri-
oration, etc. Because of the changing emission control devices required
_ in different model years, and the gradual replacement of older -non-
controlled vehicles by newer ones, emission factors are available for the
predicted mix that will be on the highways in future years. This permits
pollution control agencies, planners and others to estimate the impact of
M motor vehicles on air quality in future years.
The emission factor data for motor vehicles are derived from a test
cycle through which various makes and models of vehicles are run, and
their emissions measured. The cycle is presumed to represent some sort of
typical everyday driving pattern. There is substantial controversy about
whether the Federal Government's, or any other, test cycle is in fact
representative of real driving conditions anywhere. The State of
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California, for example, has its own cycle which it claims is a more
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realistic representation of California-driving patterns. We, in Northern m
California, wonder if that cycle, based upon Los Angeles driving conditions
several years ago, is representative of driving in the San Francisco Bay
Area. The average emission factor data in AP-42, as noted, is based upon
the vehicle mix for the entire nation. In the absence of other data, or |
if more elaborate computations are not warranted, these data should be «
used in estimating motor vehicle pollution.
Because of the required installation of certain pollution control
devices in California before they were required elsewhere, special
factors should be used. Information for computing these factors is |
available in the EPA application, An Interim Report on Motor Vehicle M
Emission Estimation, by Kircher and Armstrong (EPA-450/2-73-003). This *
report also contains data and instructions for calculation of average B
emission factors for a vehicle mix that is different from the national
average. Some communities, for example, may have a higher proportion of |
new cars, with tighter emission controls, than the average. For other _
communities the reverse may be true. *
Data on the model year mix for different regions are often available B
from state motor vehicle bureaus, if one is interested in taking these
variations into account in their calculations. The California Air I
Resources Board and the California Department of Transportation have
emission factors for the California vehicle mix, and the Bay Area Air .
Pollution Control District has factors for the Bay Area mix. The latter
factors were obtained using data derived from the California driving
cycle and happen to be the ones I use at the moment. I
While the compilations of emission factors cited show how to obtain
emission factors for vehicles operating at different speeds, none of them
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« list an emission factor for idling emissions, or for speeds below about
10 miles per hour. Factors for these modes are required when evaluating
B emissions from parking lots, drive-in operations, downtown core city
areas, etc.. The chart that has been distributed shows how to obtain
£ idling emission factors for the various contaminants. They were derived
from information presented in the report, A Study of Emissions From Light
Duty Vehicles in Six Cities, prepared for EPA by Automotive Environmental
Systems, Inc., March, 1973 (EPA No. APTD-1497).
Computation of Emissions
As previously discussed, emissions data for use as model imput
usually must be supplied as emission rates, that is, mass of pollutant
emitted per unit time (grams per second, tons per day, etc.). An
| example was provided earlier showing how to do this for a single
. stationary pollution source, the car body incinerator. The calculation
is somewhat more complicated for mobile sources, but the principle is
flj the same.
The trick is to find a way to treat a mobile source as if it were
| stationary. One way to do this is to take the emissions averaged over a
^ period of time along the path of a vehicle. The path then becomes the
source, and if the path happens to be a road, it usually remains
stationary for whatever period one wishes to consider its emissions.
Thus, a convenient way to treat motor vehicle emissions in a model is
to treat the roadways full of vehicles as line sources. As an example,
let's take the following data and compute the average carbon monoxide
emissions along a road segment:
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Length of road = 2 miles g
Average vehicle speed = 25 mph
Average hourly traffic = 200 vehicles per day
Assume that the'year is 1974 and the vehicle mix is about the same
as the national average. From Figure 1, the emission factor for CO for
the 1974 vehicle mix is 56 grams per vehicle-mile. The speed correction
factor to be applied can be determined from the figure to be about 0.8. I
The corrected factor is 56 x 0.8 = 45 grams per vehicle-mile. Then:
45 grams/vehicle-mile x 200 vehicles/hr x 2 miles = fl
18000 .grams/hour, or after conversion of units,
5 grams/second over the 2 miles length.
Some line source models require that emissions be expressed as _
emission rate per unit length. In the above example, that figure could
be obtained by multiplying the emission factor by the average hourly
traffic. The result is 7000 grams/hour mile, and could, of course, be
converted into whatever units are appropriate for the model in which the I
data is to be used.
Use.of Emissions Data
It was mentioned earlier that an area source is simply a collection |
of small point sources distributed and averaged over a geographical area. _
The degree of resolution of most regional air pollution models is at
best the order of a square kilometer. That is, most models cannot dis- I
tinguish -between sources that are enclosed within an area smaller than
that. Therefore, it is reasonable in many instances to lump groups of 8
small sources together and to treat them as an area source. By doing this, _
the necessity for obtaining detailed emissions data for each individual
source is eliminated and overall average data for the area may be used
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Figure 1
AVERAGE EMISSION FACTORS FOR HIGHWAY VEHICLES BASED ON NATIONWIDE STATISTICS
Carbon
monoxide
Hydrocarbons
Exhaust
Year
g/mi
g/km ! g/mi
g/km
Crankcase and
evaporation
g/mi
Nitrogen
oxides
(NOxasNO2)
g/km
g/mi
g/km
Participates
Exhaust
g/mi g/km
Tire wear
g/mi g/km
Sulfur
oxides (S02)
g/mi
g/km
1965
1970
1971
1972
1973
1974
1975
1976
1977
1978
1979
1980
1990
89
78
74
68
62
56
50
44
37
31
27
23
12
55
48
46
42
39
35
31
27
23
19
17
14
7 5
9.2
78
7.2
6.6
6.1
5.5
5.0
4 3
3.7
3.2
2.7
2.4
1.3
5 7
4.8
4.5
4.1
3.8
3.4
3.1
2.7
2.3
20
1.7
1.5
0 81
5.8
3.9
3.5
2.9
2.4
2.0
1.5
1.3
1.0
0.83
0.67
0.53
0.38
3.6
2.4
2.2
1.8
1.5
1.2
0.93
0.81
0.62
0.52
0.42
0.33
0.24
4.8
5.3
5.4
5.4
5.4
5.2
5.0
4.8
4.3
3.8
3.4
3.1
1.8
3.0
3.3
3.4
3.4
3.4
3.2
3.1
3.0
2.7
2.4
2.1
1.9
1.1
0.38
0.38
0.38
0.38
0.38
0.38
0.38
0.38
0.38
0.38
0.38
0.38
0.38
0.24
0.24
0.24
0.24
0.24
0.24
0.24
0.24
0.24
0.24
0.24
0.24
0.24
0.20
0.20
0.20
0.20
0.20
020
0.20
0.20
0.20
0.20
0.20
0.20
0.20
0.12
0.12
0.12
0.12
0.12
0.12
0.12
0.12
0.12
0.12
0.12
0.12
0.12
0.20
0.20
0.20
0.20
0.20
020
0.20
0.20
020
0.20
0.20
0.20
020
0.12
0.12
0.12
0.12
0 12
0 12
0 12
0.12
0.12
0.12
0.12
0.12
0 12
1.5
tt:
o
o
o
LU
DC
O
O
Q
LU
LU
Q.
1.0
0.5
SULFUR OXIDES-PARTICUIATE (0.25L
ASSUMING SPEED INDEPENDENCE
Parenthetical
quantities are
factors for obtaining
idling emission factors
from the average emission
factors in the table.
(0
Multiply the factor in paren- >*
thesis by the average emission
factor in grams per mile to obtain an
idling emission factor in grams per minute.
hydrocarbons, use total emissions ("exhaust
case and evaporation). For particulates, use
exhaust factor only. Speed correction curves are
not involved in idling emissions.
For
+ crank-
165
15
30 45
AVERAGE ROUTE SPEED, mi/hr
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to estimate emissions.
This means that one can start with emissions data for a region or
county to derive an emission factor that can be used to compute emissions
for a much smaller area. For example, since pollution from residences is
primarily a result of fuel burned in heating and cooking, if pollutant |
emissions from domestic fuel consumption are available for a county (as «|
they are for the Bay Area), those figures could be divided by the county
population (or number of dwelling units) and a figure for emissions per
person (or dwelling unit) can be obtained. This factor can then be used
to compute the emissions for any development or sub-area of the county |
with a specified population. Similarly, if county-wide data for emissions «
from industrial sources is available, factors could be developed that *
would express emission rates per unit of industrial area or per person I
employed. In the absence of more detailed information these factors
could be useful in estimating pollutant emissions for some projected J
industrial development. '
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REFERENCES CITED
| 1) The table and curves were taken from Compilation of Emission Factors,
» EPA publication No. AP-42, April, 1973. The idling emission factors were
* derived from data presented in A Report by GEQMET Concerning Traffic
I Behavior in and Around Shopping Centers and Related Shopping Center
Characteristics, 1975.
| The units of the numbers shown in parenthesis, from which idling
emission factors are to be computed, are miles/minute. In order to
obtain idling emission factors with proper units (grams/minute) the
numbers in parenthesis should be multiplied by the factors in the table
with units of grams/mile.
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METEOROLOGICAL MODELING INPUT
Richard H. Thuillier
Introduction
As has already been discussed, there are a number of meteorological
elements, such as wind speed and direction and atmospheric stability,
which are important in determining the extent to which pollutants
M emitted from sources are dispersed or diluted in the atmospheric medium.
A subsequent presentation will discuss the use of mathematical models in
relating emissions of air pollutants to the resultant concentrations.
Since meteorological factors determine the extent of dispersion, the
| models, quite obviously, must utilize meteorological information as input.
_ Some of the meteorological elements, such as wind speed, are input
directly to the modeling algorithms while others which may be necessary
B but are not readily obtained, such as atmospheric stability, are "para-
meterized" before being input to the models. Parameterization means that
| the element is not input directly to the model but is substituted for by
_ another factor which is related and more readily obtainable.
This presentation will describe the specific types of direct or
parameterized meteorological information which are necessary as input to
the types of models which will be used. In selecting meteorological input
data, and in utilizing the models, the aid of a professional meteorologist
or a professional engineer with a background in meteorology is most
desirable. Those agencies which expect to be involved on a continuing
basis with air quality impact analyses should strongly consider employing
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a staff person who can engage full time or a good part of the time in
developing and utilizing modeling techniques, with appropriate meteoro-
logical and emissions inputs, specifically tailored to the needs of the
agency or firm. A library of meteorological and climatological data
should be assembled to be used as a ready reference to avoid repeated
consultation with data source agencies.
I
Mixing Height Characteristics
Some of the models which will be discussed require the height of I
the mixing layer which is the unstable layer next to the ground through
which pollutants omitted at ground level are vigorously mixed. In
general, the mixing height will only be useful when the impact of the
source is to be obtained for a receptor site some ten kilometers or more
from the source. The reason for this is that the pollutants are mixed
relatively slowly up from ground level and must be carried a considerable
distance downwind before they will ever reach the top or "lid" of the » I
mixing layer.
As mentioned in the presentation on Meteorology, the height of the
mixing layer varies from place to place and from time to time at a given
place. Since it is rare that there will be more than one observing
station in a region from which statistics on the characteristics of |
mixing height may be obtained, the place to place variability within a
region will be a desirable but unobtainable item of information. In
such cases one must assume that the information from that station is
representative of the entire region, although it may qualitatively be
assumed that parts of the region with appreciably warmer (or colder) |
temperatures than the location of the observing site will have correspond- ^
ingly higher (or lower) mixing heights. In any event, since there is a V
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whole spectrum of mixing heights which-occur in the course of a year, as
| many different weather regimes affect the region. One must decide which
« of these to use as modeling input. One statistic which is quite useful
in modeling is the annual average mixing height. Two other statistics of
fl use are the average morning mixing height and the average afternoon
mixing height. Finally, the lowest mixing height expected in the course
| of a year will be useful in worst case analysis applications.
^ Calculation procedure: Throughout the continental United States,
balloon (radiosonde) soundings are made twice a day, between three and
B six in the morning, approximately, and between three and six in the
afternoon, approximately. The temperature of the air as a function of
height may be plotted on graph paper as shown in Figure 1. The standard
procedure for calculating both the morning (minimum) and afternoon
(maximum) mixing depth is to use the balloon sounding. The minimum
mixing depth is obtained by adding 5 degrees Centigrade to the minimum
(lowest) temperature during the day and drawing a line representing a
decrease in temperature of 3 degrees Centigrade per thousand feet of
altitude as shown in Figure 1. The point of intersection of this line
with the plotted sounding curve indicates the minimum mixing height. The
maximum mixing height is obtained using the same procedure but substitu-
ting the maximum ground level temperature as shown in the figure. Where
the soundings are made at official National Weather Service sites,
statistics on mixing height have already been obtained on a climatological
basis. These statistics have been summarized in the form of isopleth maps
over the contiguous United States in Mixing Heights, Wind Speeds and
Differential for Urban Air Pollution Throughout the Contiguous United
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States.
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A
H
H
I
G
H
T
Observed
temperature
sounding
Afternoon Glaxinmm)
mixing height
. Temperature decrease
.-^ of 3 deg. C per
\ 1000 feet.
\
Morning
mixing height
i
\ Min. Temp.
7+ 5 deg. C.
\
\ Max. Temp
TEMPERATUkh
rri^ure 1. Illustration of mixing height computation
172
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Air Flow Characteristics
As input to dispersion models, two items of information relative
to the characteristics of air flow are necessary: the direction and the
speed of the wind. For impact analyses in the immediate vicinity of a
project, such as a shopping center, wind information should be obtained
from an observing site as close to the site as possible, since wind
characteristics vary from place to place, particularly in areas with
complex terrain. As a general rule of thumb, wind information from a
| site further away from the project site than the nearest prominent
« terrain feature should not be used without consulting a professional
~ meteorologist regarding its representativeness. As in the case of mixing
B height, wind information is profitably obtained on a annual averaged
morning, afternoon and worst case basis. In the case of wind direction,
B we do not usually obtain averages of different directions but rather we
obtain the frequency of occurrence of the various directions.
Wind roses: A wind rose may be defined as a comprehensive descrip-
tion of wind characteristics at a site in terms of a fixed number of wind
directions observed at a site and the wind speed characteristics associated
| with each direction. The statistics included in a wind rose consist of
the frequency (number of times or percent of the time) with which each
direction has been observed to occur and the average wind speed or
frequency of occurrence of different wind speeds associated with each
direction. Usually, the wind rose also contains information on the
frequency of "calms" which is the frequency with which the instrument used
to measure the wind ceases to be moved by the flow of air. Caution
should be exercised in interpreting the percent of calms, since different
instruments will show greater or lesser sensitivity to air motion due to
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factors such as age, quality or maintenance and type of instrument.
Typical airport wind instrumentation, particularly the older models, will
cease to record air movement when the speed of the wind drops below 3 I
or 4 miles per hour. More sensitive; research type instrumentation may
respond to wind speeds of 1 mile per hour or less. True calms usually
occur only momentarily, if at all, and the usual practice when inputing
wind rose information to a model is to distribute the indicated calms
by apportioning them to the various wind directions in accordance with I
i
either the frequency of occurrence of the individual directions or with M
the frequency of occurrence of the lowest measureable wind speed range
in each of the directions. Strictly speaking, a wind rose is only
representative of the site of the measuring instrument although in
relatively flat and uniform terrain they may be extrapolated with caution jj
for miles or even tens of miles. A meteorologist should be consulted .
if possible before such extrapolation is attempted. Figure 2 illustrates
a wind rose with sixteeen direction sectors. ' I
Wind patterns: When impact is to be analyzed over an entire region
or at a considerable distance from a project site, wind patterns may be ||
more beneficial than wind roses. A wind pattern consists of curved _
arrows indicating the direction of air flow throughout a region and is
obtained by mapping wind direction observations at a given time from all
stations in the region and drawing arrows following the indicated flow
of the air. Statistics on the frequency of occurrence of each of a number I
of patterns may be developed in the same way that such statistics are
developed for each of a number of wind directions at a site. Unfortunately,
wind pattern information is not as readily available as wind rose infor-
mation. Wind speed can be represented in pattern form by drawing isotachs
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percentage distribution of wind directions
with mean wind speed beneath
1
*
a-
D
0)
13
u
K5
§c
i
o
1
0)
E
^*
«*-
0
>«
0-
10-
20-
30-
40-
50-
60-
70-
80-
90-
inn.
\
x
\
\
\
\
\
\
\
\
\
\
\
X
^>
station: San Jose AP
location la: 37°22'N|o;i2i°55'w
period: 1965-1967
no. of observations: 26,276
frequency: hourly
10
35
1$ . 20 .25 30
wind speed (mph)
cumulative wind speed distribution
40
45
Figure 2. Example of a wind rose consisting of sixteen direction
sectors. Large numbers in the sectors indicate the percentage of
time that the wind is from the indicated direction in the course
of a year. Small numbers are the average wind speeds for the
indicated directions. The percentage of calms is in the center.
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or lines of equal wind speed on the same map as the direction arrows or K
flow lines. Figure 3 illustrates a wind pattern for a given region.
Vertical structure: Because of the drag exerted on the air as it I
flows over the rought surface of the earth, the speed of the wind in the
mixing layer is usually lowest at the ground and increases gradually with
altitude reaching a maximum or attaining a nearly constant value several _
hundred feet above the ground. In the case of a city or town with a
fairly high density of structures, the same description applies with the
average rooftop height substituted for the ground. Below rooftop height,
the wind characteristics become very complicated and may differ consider- I
ably over distances of tens of feet horizontally and vertically. Above
relatively smooth and level ground such as that which exists at an airport
site, wind speed my increase by 50 percent between the level of the in-
strument and the top of the mixing layer. Over a city or town, the
increase in wind speed with height above the rooftops may be somewhat
greater.
When modeling the impact of a project in the immediate vicinity, M
the ground level or rooftop wind speeds will usually suffice. When
modeling impact regionally or at a considerable distance from a source,
it is reasonable to increase the ground level or rooftop wind speeds by I
some 25 percent to account for the higher average wind speed over the
vertical extent of the plume (pollutant cloud). When modeling the impact 0
of elevated sources such as power plant stacks, a wind speed representa-
tive of the height of the plume should always be used. Finally, regardless
of the application, care should be taken to ascertain that the instruments
used to obtain wind data used in an impact analysis are reasonably well
maintained and located in an area which is relatively free of nearby p
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Figure 30 Example of a wind pattern. Short arrows through dots
indicate wind observations at stations. Curved arrous indicate
the assumed pattern of wind flow based on the observations.
Dashed lines are isotachs or lines of equal speed based also on
the wind observations. Wind observations are those taken at the
same time of day.
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obstructions to wind flow. Suspect data should be eliminated from use in
the analysis.
Stability Characteristics
As mentioned previously in the meteorology paper, the temperature
structure, or stability, of the mixing layer will determine the extent to
which the plume emitted from a source is diluted after traveling a given |
distance. In most cases, it is almost impossible to obtain direct infor- «
mation on the temperature structure in the vicinity of a project site or
even for the region as a whole. Moreover, the extent of dilution is V
partially determined by other factors such as terrain roughness, wind
speed and the degree of isolation or solar heating of the ground in con- |
junction with the temperature structure, the interrelationship of these _
being somewhat complicated. To get around most of the problems of
stability input to air quality models of the type which will be illustrated,
an empirical system for relating the rate of plume dilution to readily
obtainable information has been devised. This system termed the Pasquill-
Gifford approach, after the two researchers involved in its development,
relates the spread of a gaussian or normally distributed plume to six
categories of stability which are in turned defined in terms of the
general weather conditions in the area of concern. Figure 4 provides
the description of the stability categories and Figure 5 indicates the
relationship between the stability categories and the rate of plume
dilution taken as the change in plume standard deviation with distance
from the source. The curves in Figure 5 may be fit with straight line
segments on the log-log plot which segments are represented by the equation
a = aX
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Figure- 4.
KEY TO STABILITY CATEGORIES
Surface Wind
Speed (at 10 m)
m/sec
< 2
2-3
3-5
5-6
> 6
Strong
A
A-B
B
C
C
Insolation
Moderate
A-B
B
B-C
C-D
D
Slight
B
C
C
D
D
Night
Thinly Overcast
or
>4/8 Low Cloud
-
E
D
D
D
< 3/8
Cloud
-
F
E
D
D
The neutral category, D, should be assumed for overcast conditions
during day or night
Strong insolation is nsrociated uitb a sun's elevation
of greater than 60 dejrees above the horizon. Moderate
insolation is associates with an elevation between 30
and oO de,;r-.-es ana sligit insolation is associated with
at- elevation ot less than 30 degrees. Categories have
^een ceveloped from ch.ta gathered in ri'ral locations
with relatively smooth terrain and tend to indicate
greater stability than that : hich actually exists in
urban locations. In such urban settings, it is con11 on
practice to shift toward instability by one category
to account for the tic re unstable conditions associated
ith highly developed areas.
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10,000
1,000
0)
-P
0)
S
Figure 5a.
DOWN₯IOT) DISTANCE X (Kilometers)
VarJation of horizontal plume concentration standard
devlat.ion,CT, with downwind distance from a point
source. Constants in the fitted function 0"=aX"
av*.; fjivGii for the entire range of down-rind ydistance.
( /'" r- . reference 2i
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1 10
DOWNWIND DISTANCE X (Kilometers)
igure 5b. Variation of vertical plume concentration standard
deviation,,^, with downwind distance from a point
Gonrco. Constants in the fitted function CT^aX"
are given for the less than IKrn and l-10Km ranges
of downwind distance. (After reference 3)
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where a is the plume standard deviation and X is the distance from the
source. Figure 5a indicates the characteristics of horizontal plume
spread while Figure 5b indicates the characteristics of vertical plume
spread. The full six categories of stability are usually found only in
rural areas and, indeed, the empirical studies from which the curves and
categories were derived were conducted in flat rural areas. When using
the system in a relatively urban setting, it is reasonable, based on
observations,to select the next most unstable category to the one indicated |
by the meteorology. Thus an E category might be chosen where an F is mt
indicated. In large cities, the mixing layer rarely becomes more stable
than a C or D category and a B or C is usually appropriate as an average
condition as opposed to a C or D in a more rural setting. A computer
program called the STAR program is available from the National Climatic |
Center, Asheville, North Carolina, which provides a statistical frequency
distribution of the various stability categories for each direction of the *
wind rose, based on meteorological observations primarily at airport Ij
stations. While this information is quite useful, care should be exer-
cised in extrapolating the data to other sites. |
Pollutant Level Variability as a
Me teorologica1 Paramter
Since the federal and most of the state and local air quality I
standards are given in terms of a pollutant level which must not be ex-
ceeded more than a certain percentage of the time, usually no more than
one time per year, it is usually only the extreme situations that we
wish to model. Unfortunately it is quite difficult to define the
combination of meteorological conditions that lead to the highest |
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concentration of the year or to distinguish those conditions from condi-
tions associated with lower concentrations. When we can define them, it
is often difficult to model them since they involve such intractable
situations as calm or variable winds. Finally, since the standards in-
volve different averaging times, such as 1, 3, 8 and 24 hours, it is
difficult if not impossible to average the meteorology over all the
applicable averaging times.
One very handy way to circumvent this problem is to take advantage
j of a statistical model (reference 2) based on the log-normal distribution
function observed to fit most pollutant concentration data. To use this
approach, the standard geometric deviation, which describes the annual
variability of the data, is obtained as described in the reference for
| any given averaging time. Pollution data is usually obtained in the form
_ of one-hour averages. Once we know the standard geometric deviation and
the frequency of occurrence of any concentration over any averaging annual
I average concentration (arithmetic mean), standard geometric deviation and
the ratio of annual maximum to annual average concentration is given in
| Table 1.
The principal advantage in using this approach is that the various
meteorological regimes leading to the various levels of pollution ob-
M served in the course of a year are represented on a statistical basis by
the pollutant concentration distribution itself. If we are not concerned
E about the specific days of the year on which concentration extremes occur,
we can estimate those extremes from the distribution function without any
knowledge of the extreme meteorological conditions which produced them.
If, further, we can assume that the annual variability is related primari-
ly to the climatology of an area, a one time determination of standard
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Table 1.
Standard geometric deviation for
averaging times of:
1 sec
1.00
1.07
1.14
1.21
1.29
1.36
1.44
1.51
1.59
1.67
1.75
1.83
1.91
1.99
2.08
2.16
2.25
2.34
2.42
2.51
2.60
2.69
2.78
2.87
2.97
3.06
3.15
3.25
3.34
3.44
3.54
3.64
3.74
3.83
3.93
4.04
4.14
4.24
4.34
4.45
4.55
4.66
4.76
4.87
4.97
5min
1.00
1.06
1.11
1.17
1.23
1.29
1.34
1.40
1.46
1.52
1.58
1.64
1.70
1.76
1.82
1.88
1.94
2.00
2.06
2.12
2.19
2.25
2.31
2.37
2.43.
2.50
2.56
2.62
2.69
2.75
2.81
2.88
2.94
3.00
3.07
3.13
3.20
3.26
3.33
3.39
3.46
3.52
3.59
3.65
3.72
1hr
1.00
1.05
1.10
1.15
1.20
1.25
1.30
1.35
1.40
1.45
1.50
1,55
1.60
1.65
1.70
1.75
1.80
1.85
1.90
1.95
2.00
2.05
2.10
2.15
2.20
2.25
2.30
2.35
2.40
2.45
2.50
2.55
2.60
2.65
2.70
2.75
2.80
2.85
2.90
2.95
3.00
3.05
3.10
3.15
3.20
3hr
1.00
1.05
1.09
1.14
1.19
1.23
1.28
1.32
1.37
1.42
1.46
1.51
1.55
1.60
1.64
1.69
1.74
1.78
1.83
1.87
1.92
1.96
2.00
2.05
2.09
2.14
2.18
2.23
2.27
2.32
2.36
2.41
2.45
2.49
2.54
2.58
2.63
2.67
2.71
2.76
2.80
2.84
2.89
2.93
2.98
8hr
1.00
1.04
1.09
1.13
1.17
1.22
1.26
1.30
1.34
1.39
1.43
1.47
1.51
1.55
1.59
1.63
1.68
1.72
1.76
1.80
1.84
1.88
1.92
1.96
2.00
2.04
2.08
2.12
2.16
2.20
2.24
2.27
2.31
2.35
2.39
2.43
2.47
2.51
2.55
2.59
2.62
2.66
2.70
2.74
2.78
1day
1.00
1.04
1.08
1.12
1.16
1.20
1.24
1.27
1.31
1.35
1.39
1.42
1.46
1.50
1.53
1.57
1.61
1.64
1.68
1.71
1.75
1.78
1.82
1.85
1.89
1.92
1.96
1.99
2.03
2.06
2.09
2.13
2.16
2.19
2.23
2.26
2.29
2.33
2.36
2.39
2.42
2.46
2.49
2.52
2.55
4 days
1.00
1.04
1.07
1.10
1.14
1.17
1.20
1.24
1.27
1.30
1.33
1.36
1.39
1.42
1.45
1.48
1.51
1.54
1.57
1.60
1.63
1.66
1.69
1.72
1.74
1.77
1.80
1.83
1.85
1.88
1.91
1.93
1.96
1.99
2.01
2.04
2.07
2.09
2.12
2.14
2.17
2.20
2.22
2.25
2.27
1 mo
1.00
1.03
1.05
1.08
1.10
1.12
1.15
1.17
1.19
1.21
1.24
1.26
1.28
1.30
1.32
1.34
1.36
1.38
1.40
1.42
1.44
1.46
1.47
1.49
1.51
1.53
1.55
1.56
1.58
1.60
1.62
1.63
1.65
1.67
1.68
1.70
1.71
1.73
1.75
1.76
1.78
1.79
1.81
1.82
1.84
Ratio of annual maximum concentration to mean
concentration for averaging times of:
1 sec
1.00
1.44
2.04
2.83
3.86
5.18
6.85
8.94
11.53
14.69
18.53
23.14
28.65
35.16
42.83
51.78
62.18
74.18
87.96
103.70
121.61
'.41.88
164.73
190.39
219.09
251.07
286.61
325.94
369.37
417.15
469.60
527.00
539.67
657.92
732.07
812.47
899.45
993.34
1094.51
1203.31
1320.11
1445.27
1579.16
1722.17
1874.68
5 min
1.00
1.27
1.59
1.97
2.42
2.93
3.51
4.18
4.93
5.77
6.71
7.76
8.92
10.19
11.58
13.11
14.76
16.56
18.50
20.59
22.83
25.24
27.81
30.55
33.47
36.56
39.84
43.31
46.97
50.82
54.88
59.14
63.60
68.28
73.17
78.28
83.61
89.16
94.94
100.94
107.17
113.64
120.34
127.28
134.46
1 hr
1.00
1.20
1.43
1.69
1.97
2.28
2.63
3.00
3.41
3.84
4.32
4.82
5.37
5.95
6.56
7.21
7.90
8.62
9.39
10.19
11.03
11.91
12.83
13.78
14.78
15.81
16.89
18.00
19.15
20.34
21.57
22.84
24.14
25.49
26.87
28.29
29.75
31.24
32.78
34.35
35.95
37.60
39.28
40.99
42.74
3hr
1.00
1.17
1.37
1.57
1.80
2.05
2.31
2.60
2.90
3.22
3.56
3.92
4.30
4.70
5.12
5.55
6.01
6.49
6.98
7.49
8.03
8.58
9.15
9.74
10.34
10.97
11.61
12.27
12.94
13.64
14.35
15.07
15.82
16.58
17.35
18.14
18.95
19.77
20.60
21.45
22.32
23.20
24.09
25.00
25.92
8hr
1.00
1.15
1.31
1.48
1.66
1.86
2.06
2.28
2.51
2.75
3.00
3.26
3.53
3.81
4.10
4.40
4.71
5.03
5.36
5.70
6.04
6.40
6.76
7.14
7.52
7.91
8.30
8.71
9.12
9.54
9.97
10.40
10.84
11.28
11.74
12.20
12.66
13.13
13.61
14.09
14.58
15.07
15.57
16.07
16.57
1day
1.00
1.12
1.25
1.38
1.52
1.67
1.82
1.98
2.14
2.31
2.48
2.65
2.84
3.02
3.21
3.40
3.60
3.80
4.00
4.21
4.42
4.64
4.85
5.07
5.29
5.52
5.75
5.98
6.21
6.44
6.68
6.92
7.16
7.40
7.64
7.89
8.13
8.38
8.63
8.88
\\ -X
9.13
9.38
9.64
9.89
10.15
4 days
1.00
1.09
1.18
1.27
1.36
1.46
1.56
1.65
1.75
1.85
1.95
2.05
2.15
2.26
2.36
2.46
2.57
2.67
2.77
2.88
2.98
3.09
3.19
3.30
3.40
3.51
3.61
3.72
3.82
3.93
4.03
4.13
4.24
4.34
4.44
4.55
4.65
4.75
4.86
4.96
5.06
5.16
5.26
5.36
5.46
1 mo
1.00
1.04
1.08
1.12
1.16
1.20
1.24
1.28
1.31
1.35
1.38
1.42
1.45
1.48
1.52
1.55
1.58
1.61
1.64
1.67
1.70
1.73
1.75
1.78
1.81
1.83
1.86
1.88
1.91
1.93
1.96
1.98
2.00
2.03
2.05
2.07
2.09
2.11
2.13
2.16
2.18
2.20
2.22
2.24
2.25
Tc use this table, find the line containing the appropriate
standard geometric deviation for any single averaging time (left
side). h'rom that line may be obtained either the standard geo-
metric deviation for ether averaging times (left side) or the
ratic cf maximun concentration at various averaging tines to the
annual averaged concentration (From Reference 2).
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geometric deviation will suffice as a "climatological" parameter for use
m in future years, if based on a number of years of data. This is quite
convenient for land use planning applications since we need only model
I the annual average concentration in future years and apply the climato-
logical standard geometric deviation in order to estimate the frequency
| of excess of any air quality standard.
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REFERENCES CITED
1. Holzworth, G.C., 1972. Mixing Heights. Wind Speeds and Potential
for Urban Air Pollution throughout the Contiguous Unites States, EPA ]|
Office of Air Programs Publication No. AP-101.
2. Larsen, R.I., 1971. A Mathematical Model for Relating Air Quality I
Measurements to Air Quality Standards, EPA Office of Air Programs
Publication No. AP-89.
3. Turner, D.R., 1969. Workbook of Atmospheric Dispersion Estimates, I
EPA Office of Air Programs Publication No. AP-26.
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SIMPLIFIED TECHNIQUES FOR AIR QUALITY
IMPACT QUANTIFICATION
_ Richard H. Thuillier
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Preface
The formulas presented herein represent adaptations of the basic
gaussian plume model which treats the pollutant plume from a point source
as though the concentrations in the plume are distributed normally about
the centerline. iVhen the input parameters such as wind speed, stability
category and emission rate are thoughtfully chosen, preferably with
| professional consultation, the results should prove adequate as input for
_ many of the day to day decisions related to the air quality impact of
projects. Except in instances where emissions and meteorological data of
high quality and fine spatial and temporal resolution are available, it
is doubtful that more sophisticated techniques will yield results of any
greater validity. A summary of formulas is presented in Appendix B.
In utilizing the formulas, the units of the input parameters should
I
be consistent throughout the formulas. The most convenient units to use
V are micrograms, meters and seconds for mass, length and time, respectively.
If these units are used, the concentration values derived from the formu-
las will be in the units of micrograms per cubic meter, units .which are
directly comparable to those used in the published ambient air quality
standards. While the gaussian plume model has been extensively verified,
use of these adaptations in specific situations is best preceeded by a
test of the formulas in known situations, if possible. The models may
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then be adjusted to conform more closely to the local situation. Such
adjustment may be accomplished by varying the values of the input
parameters within their respective ranges of uncertainty. m
The example problems worked out in the course of this presentation
have assumed carbon monoxide as the pollutant. The choice of carbon |
monoxide was made since this pollutant is considered most representative .
of the surface emitted and relatively inert pollutant type for which these *
modeling procedures are best suited. The techniques, however, may be H
applied quite successfully to other pollutants such as suspended particu-
lates, total oxides of nitrogen, hydrocarbons and sulfur dioxide. I
In making this presentation, we do not wish to imply that the
methodology described will be sufficient in and of itself. Utilization
of the methods will be greatly facilitated by background knowledge gained
by reading the reference material. In cases where the validity of the
assumption is in doubt, competent professional assistance should be
obtained. It is strongly recommended that public and private agencies,
involved on a continuing basis with the performance or evaluation of air
quality analyses, designate a staff person with technical background to
develop a familiarity with and competence in the use of these and other
techniques of air quality modeling. M
9
Introduction
As the result of provisions in the National Environmental Policy
Act and the Clean Air Act and as the result, also, of ensuing legislative, £
regulatory and judicial action on the federal, state and local level,
there exists today a requirement to analyze and report upon the impact on
air quality of a large variety of land use and transportation projects.
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For the sole purpose of accomplishing this task, a large variety of
_ analysis techniques, usually referred to as air quality "models" have
been developed. Some of these models, in attempting to simulate with
I great fidelity the complex physical and chemical processes involved in
the transport, dispersion and transformation of the various pollutant
I species in the atmosphere, have evolved as sophisticated mathematical
systems and require a considerable expenditure of time and money for their
application. Other models, highly parameterized and simplified in their
mathematics, are applied quite readily at minimal expense.
- Studies such as those described in references 1 and 2 have indicated
that for reasons probably related to the limited quantity and quality of
modeling input data, the added complexity of the sophisticated models is
no guarantee of improvement over the more simplified versions. My own
experience, over several years of providing guidance for decision making
in the area of air quality impact, strongly suggests that many and perhaps
most of the decisions relating to air quality impact can be made with
confidence on the basis of highly simplified analyses. This is quite
fortunate since limitations of time, funding and manpower frequently
dictate a choice between a simplified analysis and no analysis at all.
Having made a case for simplified approach to air quality impact
analysis, the problem still remains of choosing from the great variety
of available techniques. The appropriate choice and effective application
of even the simplest techniques requires some familiarity with the
« atmospheric processes which the "models" seek to represent. For the
uninitiated, there is no substitute for competent consultation in this
regard. In many cases, however, not even this avenue is open to the
harried individual charged with the preparation of an air quality impact
B 189
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report. This being the case, effective techniques, though available, will
go unused due to lack of guidance in their application.
I
All of this would seem to suggest that there is a need for guidance
relating to the choice and use of adequate, pertinant and highly cost I
effective analysis techniques. In the interest of filling this need to
some extent, I have put together a set of guidelines for analyzing the
impact on air quality of a variety of source types. The methods are I
those which I, myself, employ routinely as a professional meteorologist
and air quality analyst. In providing these guidelines, there is no |
intent to deny the value or deprecate the use of other approaches. The .
intent is simply to provide a cost effective and feasible alternative to *
the virtual neglect of air quality considerations which so often
characterizes environmental impact reporting.
1
Modeling Rationale
In an approach to simplified but meaningful analysis, I have
assembled a number of formulas or algorithms and will describe their
requirements of an adequate impact evaluation. In this regard, the
analysis should:
a. Consider the contribution from all sources; local and
regional, anthropogenic and natural, project and non-project.
The reason, of course, is that the significance of a project's |
impact must be judged in terms of the setting in which it . M
occurs.
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b. Provide a quantitative description of the impact which may
readily be compared with applicable federal, state and local
air quality standards, for all standard-related pollutants.
c. Estimate the impact in the immediate vicinity of the project
site as well as at more distant locations.
d. Estimate the impact on a number of spatial scales reflecting
the mobility of receptors over the time periods associated
with the air quality standards.
g| e. Take cognizance of any sensitive receptor sites such as
hospitals or playgrounds at locations subject to potentially
significant project impact.
Since air quality standards specify an allowable frequency of
P occurrence (usually once per year) of given pollutant levels when
£ averaged over specified time periods, two basic approaches may be used
in the modeling. One approach, which we may call the "worst case"
tt approach, consists of applying the model under the assumption of extreme
(adverse) meteorological conditions expected to occur with the same
g frequency as that specified in a particular standard when averaged over
-- the applicable time period. The other approach, which we may call the
* "climatological" approach, consists of applying the model under climato-
logically average meteorological conditions to obtain an average level
of air quality and then estimating the extreme, infrequent levels using
statistical estimates of pollutant level variability. In attempting the
former approach, we face the problem that most models, particularly the
simpler versions, perform rather unsatisfactorily in the extreme
meteorological situations of interest. In addition, it is quite difficult
to determine the combination of meteorological conditions that constitute
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a worst case, especially over the longer averaging times, a factor which
most likely contributes to a common failure in impact reporting to address
averaging times other than one hour. The climatological approach seems
better suited to the use of simplified modeling and provides information
in a statistical form which is particularly well suited to land use I
planning applications. The analysis approach outlined in this paper m
will favor the statistical approach, although many of the techniques
are applicable in worst case situations as well. Appendix A shows the
derivation for most formulae presented.
Analysis Techniques for Non-Project Sources
Anthropogenic background: Pollutant concentrations resulting from
sources other than the project in question may be designated as background
concentrations (C, ). A convenient approach to calculating C, is to treat m
as contributors all sources lying upwind within a sector of the compass
rose as indicated in Figure 1. The width of the sector should correspond
to the width of available wind rose sectors for the location in question,
usually 22.5, 45 or 90 degrees. Within the sector, divisions should be
made at convenient distances upwind. Divisions should be made specifi- A
cally at 10 kilometers and at any upwind distance at which substantial ||
changes in source characteristics occur. The result of this procedure
is the delineation of a number of upwind source areas, the contributions
of which to C, will be determined as described below.
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In calculating the contribution of source areas greater than 10
kilometers from the receptor site, we may take advantage of the fact
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that uniform vertical mixing is usually approximated after 10 kilometers
or so of pollutant travel. This fact enables us to use the simple formula
where (C, ). is the contribution to C, from source area i in units of
micrograms per cubic meter (yg/m ),
Q is the total emission rate in micrograms per second from
* all sources in area i,
fl L is the distance from the closest to the farthest upwind
boundary of the source area in units of meters,
g A is the source area in units of square meters,
^ H is the mixing height of the source area in units of meters
' and
M U is the average wind speed in the source area in units of
meters per second.
Formula (1) is based on a box model which assumes that pollutants are
uniformly mixed in a vertical slab as it moves with the wind.
EXAMPLE 1
In this example, we refer to Figure 1. Large numbers are expressed
I in floating point or scientific notation as three digit, two decimal
place numbers followed by 10 raised to a positive or negative exponent.
In this notation, the exponent indicates the number of places to the
m right (+) or to the left (-) that the decimal point must be moved in
order to obtain the number represented by the floating point notation.
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10 Km
20 km
Wind
grid square
la
Emissions derived for
annular sectors
Ib
Emissions derived by
aggregating and appor-
tioning emissions in
individual grid squares
Figure 1. Illustration of the methodology for calculating back-
ground concentrations from source areas within a wind rose sector
of angular v\idth 0. In calculating an annual average concentra-
tion, a separate calculation is made for each sector in the wind
rose (0 usually 22j Ox 45 degrees) and the average is taken over
all sectors with each sector v.eighted by its frequency of occur-
rence. In calculating a short term average concentration when the
i.ind i?= from a single direction, an angle,^, of 22-| degrees should
be used.
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Suppose that we want to calculate the contribution of sources in
source area 4 (Figure la) to the carbon monoxide concentration at receptor
point R when the wind is from the direction indicated by the wind rose
A sector RAB. The geometric area of source area 4 may be obtained by using
the formula for the area of an annulus
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source areas to the concentration of carbon.monoxide at a receptor site
is relatively negligible when compared to the concentrations used as the
air quality standard, even under adverse meteorological conditions.
In calculating the contributions of source areas less than 10
kilometers from the receptor site, we may no longer, reasonably, take |
advantage of the uniform mixing assumption. In the case of these more »
nearby areas, a more reasonable assumption is a gaussian (normal) distri- *
bution of concentration in the vertical with the dsitribution standard fl
deviation as an increasing function of distance downwind from the source.
With' this assumption, the contribution of a nearby source area may be |
modeled as the sum of contributions from an infinite number of crosswind _
line sources assumed to comprise the source area. The algorithm for "
this model takes the form
0.8Q
AU
where a and b are the constants in the formula
= axb , (5)
(4) 1
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an empirically derived formula relating the vertical standard deviation
of the diffusing line source pollutant plume, a , as a function of down- |
wind distance, x. Definitions of the other parameters in formula (4) wm
have been, given earlier. The values of a and b depend upon general
meteorological conditions along the path of the diffusing plume as de-
scribed in reference 3 and may be obtained by fitting straight line seg-
ments to the curves in Figure 2. For the stability category C (slightly |
unstable), which I have found useful as an annual average category, a ^
and b are approximately equal to 0.11 and 0.91 respectively. ~
196 m
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1
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51 3 5 10
DOWNWIND DISTANCE X (Km)
100
Figure 2. Variation of vertical plume concentration standard
deviation 0"z with downwind distance from a point
source. Constants in the fitted function 0_=aX6
are given for the less than 1 Km and l-10Km ranges
of downwind distance. (After reference 3)
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EXAMPLE 2
Suppose we wish to calculate the contribution of sources in source
0.8xl.54xl08
1.47x10x3
0.11(0.09)
2
of 10 tons/day/km and higher can occur, concentrations 10 times higher
I
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area 3 (Figure la) to the carbon monoxide concentration at receptor point
R when the wind is from the direction indicated by the wind rose sector B
RAB. The geometric area of source area 3 is obtained from formula (2)
as 1.47 x 10 square meters. Using the values of a and b given above for J
stability category C, formula (4) may be written as _
I
where we have assumed a source area emission rate of 1.54x10 micrograms j*
per second (1 ton per square kilometer per day) and a wind speed of 3
meters per second. Solution of the above yields
i
= 39yg/m3.
Finally, applying the same formulae to source areas 2 and 1, we would ^
obtain 106 and 488 yg/m , respectively, and a total contribution from
the wind rose sector (C, ) of 703 yg/m at receptor point R. This is I
equivalent to about 0.6 parts per million. If this value seems low,
we should recall that it is based on the assumption of a 3 m/sec wind £
speed, a source emission density of 1 ton/day/km and a C stability _
category. In central business districts where emission density values *
I
as an annual average and 50 times higher during peak traffic and adverse
meteorological conditions are not uncommon. M
The calculations in examples 1 and 2 illustrate a procedure for
obtaining the concentration at a receptor point from upwind, non-project
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|[ sources. The concentration, as calculated, represents the average con-
centration over a period of time when the wind can be assumed to remain
" within the defined wind rose sector and the meteorological conditions can
A be assumed relatively uniform in space and time (quasi-steady state). If
the receptor concentration is desired as an average over a time period
involving a number of wind directions and/or meteorological states, the
procedure may be carried out separately for each and the receptor concen-
tration taken as the frequency weighted average of the individual calcu-
lations. This is commonly done when an annual average is desired by
performing and weighting the resultant concentration by the annual fre-
quency of occurrence of the sector wind direction. The weighted sector
concentrations can then be added to yield the annual average.
The procedure just described is a very satisfactory one for
m situations in which the upwind source structure consists of a relatively
dense and spatially uniform network of roads, residences, commercial and
W light industrial establishments and other source types which emit
pollutants close to ground level. Large upwind point sources such as
industrial stacks, which emit pollutants at substantial elevations,
4» should be modeled separately in accordance with procedures outlined in
detail in reference 3. Line sources such as roads, when they are
situated within 100 meters of the receptor point, should not be included
in the background analysis as described above, but should be modeled
| separately using techniques to be described below.
« Where emissions data is available in the form of average emissions
within grid squares, the same procedure may be used after aggregating or
II apportioning the gridded emissions to approximate the emissions from the
polar areas within the wind rose sector. This is illustrated in Figure
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Ib. An alternative procedure for treating the individual grid squares B
directly and for treating regional transport in rugged terrain is de-
scribed in detail in reference 4. A method for estimating the pollutant
levels averaged over an entire city is found in reference 5. _
Natural background: In addition to the background concentrations *
arising from non-project anthropogenic sources, consideration must also
be given to the background arising from natural sources of pollution.
In an urban setting, the background for most pollutants will be dominated
by the contribution from anthropogenic sources and the natural back-
ground may safely be neglected. About the only exception to this is in m
I
the case of suspended particulates. Air with an oceanic trajectory may
contain 10 to 15 yg/m of particulate on the average with an equal amount
added over land. To account for this natural background as well as for
particulate arising from anthropogenic sources but unaccounted for in
emissions inventories, it is reasonable to add from 30 to 40 yg/m to the
background levels of particulate calculated by the methods outlined in 4*
the previous section. Additional information on the natural background
of both gaseous and particulate pollutants may be found in references 6
and 7.
Use of air monitoring data.: In many urban regions, levels of 0
gaseous and particulate air pollution are monitored by air pollution g
control agencies at a number of air monitoring stations. These stations
are normally located in areas where the highest levels of air pollution
are expected to occur. When a proposed project is located in the immediate
vicinity of an air monitoring station or in an area with similar charac- £
teristics of source distribution and meteorology, pollutant concentration ^
statistics obtained at the air monitoring station may be used in place of
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* calculations for the purpose of estimating local background in the base
V year or year in which the estimate is being made. Background estimates
in future years must be made on the basis of projected emissions and the
projected effect of emission control strategies. Air monitoring statis-
_ tics may not be very useful in this regard.
Analysis Techniques for Project-Related Sources
M In the previous section, techniques were discussed for obtaining
A the background concentration in the area where a proposed project is to
be located. Concentrations arising from project emissions may be added
to the background to obtain the total air quality level in the area or
may be compared to the background level to assess the relative contribu-
B tion of the project to the ambient pollutant level. In order to estimate
M the impact of the project, whether alone or in concert with other contri-
* buting sources, three basic types of analysis are useful:
to a. An analysis of the impact spatially averaged over the area of
the project site and the immediate surroundings. A one square kilometer
f area is convenient for this, and in the case of geographically extensive
^ projects, analyses may be made separately for a number of separate areas
representing the sites of greatest emission density. The purpose of the
spatially averaged analysis is to assess the impact of the project on
receptors which move about in the project's vicinity.
b. An analysis of the impact at a substantial distance downwind
of the project site. A ten kilometer distance is recommended for this.
The purpose of the downwind analysis is to gauge the regionwide signifi-
jjf cancy of the project by estimating the impact of its emissions on distant
receptors. The distance of 10 kilometers is chosen as a typical distance
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required for concentrations to become thoroughly mixed with the ambient 9
air and hence present a reasonable basis for comparison with the
background from other regional sources. In view of the lack of a good £
definition of "regional impact", it is felt that this approach is an _
improvement over the common practice in environmental impact reporting '
of comparing project emissions with total emissions from a region.
c. An analysis of the impact of specific source elements such as
roads, parking lots and project power plant stacks, at the sites of 1
sensitive receptors such as schools, hospitals, playgrounds, nursing
f
homes and residences. The purpose of this analysis is to assess the
impact of the project emissions on receptors which might reasonably be A
expected to remain in a confined area for periods of time comparable with
the averaging times associated with the air quality standards. I
Spatially averaged analysis: If a receptor moves around in the
vicinity of a project (such as a shopper might do in the vicinity of a m
shopping center), the concentration to which the receptor will be exposed «k
will consist of the average of concentrations at all points along the path
of travel. Ideally, we would like to obtain the individual point concen-
trations, weighted by the period of time spent at each point, and average
them over an appropriate period related to an air quality standard. Since £
such an analysis would be quite extensive and since the typical receptor M
paths and microscale concentration distributions are not readily obtain-
able, a surrogate technique is suggested. For this technique, the total
emissions from all sources within a designated one by one kilometer square
(or a circle of one kilometer diameter) are obtained. This includes j§
emissions from roads, parking lots and other sources near ground level ^
but should not include emissions from elevated stacks such as project *
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f
1
f
power plant stacks. The total emissions are divided by the source area
to simulate a uniform area- wide
emission rate.
Finally, the uniform area-
wide emissions are modelled on the assumption that the concentration
produced by the area averaged emissions will approximate the path averaged
concentration produced by the actual emissions.
is a variant of formula (4) and
The algorithm for this
gives the average concentration within a
source area treated as an infinite number of cross-wind line sources and
takes the form
r °-8Q
L AU
~~"
LCl-t>J
a(l-b)(2-b)
(6)
where L is the alongwind dimension of the source area, that is one
1
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t
1
kilometer, and the other parameters are as defined earlier. If we use
a one kilometer areal dimension
as suggested and average meteorological
conditions of stability category C (a=0.113 and b=0.91), formula (6)
reduces to a simpler form suitable for a quick
concentration:
C = 150
AU '
estimate of annual averaged
(7)
The bar over C in formulas (6) and (7) indicates a spatially averaged
2
concentration, in this case over a 1 KB area.
EXAMPLE 3
Suppose a project is proposed in an area
where the average annual
wind speed is 3 meters per second and the average emission rate of
carbon monoxide from all project related sources within a one square
A
kilometer area is 30x10" micrograms per second.
1
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written as
Formula (7) may be
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C 150 ,
1x10x3
yielding an estimate o£ 1500 yg/m (1.2 ppm) as the annual averaged carbon
monoxide concentration. If concentration estimates are desired for
averaging times other than the annual average, emission rates and meteoro-
logical parameters appropriate to the desired averaging time may be used
in formula (6), or we may use Table 1.
EXAMPLE 4
an emission rate of 300x10 micrograms per second. Formula (6) may be
written as
TT 0.8x300xl06
Ixl06x2
0.094(1-0.79)(2-0.79)
yielding an estimate of 21,431 yg/m (18 ppm) as the peak hour carbon
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Suppose we wish to estimate the impact of the project in example 3 m
during the peak hour of project activity. For this case assume a 2 meter
per second wind speed, an E stability category (a=0.094 and b=0.79) and
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monoxide concentration under relatively extreme meteorological conditions. ^
While a source area dimension of one kilometer was used in the *
examples, the technique may be used with larger areas such as whole ^jt
cities or towns (reference 5) or with smaller areas such as parking lots.
In the case of very large or very small areas, the concentration average M
obtained may not be representative of the path averaged concentration of
mobile receptors. The most reasonable application of the technique is to
areas in which a large number of source elements such as road links,
parking lots and residences are distributed rather evenly over the source
area. Best results are obtained over longer averaging times such as
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Table 1.
Standard geometric deviation for
averaging tim« of:
1sec
1.00
1.07
1.14
1.21
1.29
1.36
1.44
1.51
1.59
1.67
1.75
1.83
1.91
1.99
2.08
2.16
2.25
2.34
2.42
2.51
2.60
2.69
2.78
2.87
2.97
3.06
3.15
3.25
3.34
3.44
3.54
3.64
3.74
3.83
3.93
4.04
4.14
4.24
4.34
4.45
4.55
4.66
4.76
4.87
4.97
5 min
1.00
1.06
1.11
1.17
1.23
1.29
1.34
1.40
1.46
1.52
1.58
1.64
1.70
1.76
1.82
1.88
1.94
2.00
2.06
2.12
2.19
2.25
2.31
2.37
2.43
2.50
2.56
2.62
2.69
2.75
2.81
2.88
2.94
3.00
3.07
3.13
3.20
3.26
3.33
3.39
3.46
3.52
3.59
3.65
3.72
1hr
1.00
1.05
1.10
1.15
1.20
1.25
1.30
1.35
1.40
1.45
1.50
1.55
1.60
1.65
1.70
1.75
1.80
1.85
1.90
1.95
2.00
2.05
2.10
2.15
2.20
2.25
2.30
2.35
2.40
2.45
2.50
2.55
2.60
2.65
2.70
2.75
2.80
2.85
2.90
2.95
3.00
3.05
3.10
3.15
3.20
3hr
1.00
1.05
1.09
1.14
1.19
1.23
1.28
1.32
1.37
1.42
1.46
1.51
1.55
1.60
1.64
1.69
1.74
1.78
1.83
1.87
1.92
1.96
2.00
2.05
2.09
2.14
2.18
2.23
2.27
2.32
2.36
2.41
2.45
2.49
2.54
2.58
2.63
2.67
2.71
2.76
2.80
2.84
2.89
2.93
2.98
8hr
.00
.04
.09
.13
.17
.22
.26
.30
.34
.39
1.43
1.47
1.51
1.55
1.59
1.63
1.68
1.72
1.76
1.80
1.84
1.88
1.92
1.96
2.00
2.04
2.08
2.12
2.16
2.20
2.24
2.27
2.31
2.35
2.39
2.43
2.47
2.51
2.55
2.59
2.62
2.66
2.70
2.74
2.78
1day
1.00
1.04
1.08
1.12
1.16
1.20
1.24
1.27
1.31
1.35
1.39
1.42
1.46
1.50
1.53
1.57
1.61
1.64
1.68
1.71
1.75
1.78
1.82
1.85
1.89
1.92
1.96
1.99
2.03
2.06
2.09
2.13
2.16
2.19
2.23
2.26
2.29
2.33
2.36
2.39
2.42
2.46
2.49
2.52
2.55
4 days
1.00
1.04
1.07
1.10
1.14
1.17
1.20
1.24
1.27
1.30
1.33
1.36
1.39
1.42
1.45
1.48
1.51
1.54
.57
.60
.63
.66
.69
.72
.74
1.77
1.80
1.83
1.85
1.88
1.91
1.93
1.96
1.99
2.01
2.04
2.07
2.09
2.12
2.14
2.17
2.20
2.22
2.25
2.27
1 mo
1.00
1.03
1.05
1.08
1.10
1.12
1.15
1.17
1.19
1.21
1.24
1.26
1.28
1.30
1.32
1.34
1.36
1.38
1.40
1.42
1.44
1.46
1.47
1.49
1.51
1.53
1.55
1.56
1.58
1.60
1.62
1.63
1.65
1.67
1.68
1.70
1.71
1.73
1.75
1.76
1.78
1.79
1.81
1.82
1.84
Ratio of annual maximum concentration to mean
concentration for averaging times of:
1sec
1.00
1.44
2.04
2.83
3.86
5.18
6.85
8.94
11.53
14.69
18.53
23.14
28.65
35.16
42.83
51.78
62.18
74.18
87.96
103.70
121.61
141.88
164.73
190.39
219.09
251.07
286.61
325.94
369.37
417.15
469.60
527.00
589.67
657.92
732.07
812.47
899.45
993.34
1094.51
1203.31
1320.11
1445.27
1579.16
1722.17
1874.68
5 min
1.00
1.27
1.59
1.97
2.42
2.93
3.51
4.18
4.93
5.77
6.71
7.76
8.92
10.19
11.58
13.11
14.76
16.56
18.50
20.59
22.83
25.24
27.81
30.55
33.47
36.56
39.84
43.31
46.97
50.82
54.88
59.14
63.60
68.28
73.17
78.28
83.61
89.16
94.94
100.94
107.17
113.64
120.34
127.28
134.46
1hr
1.00
1.20
1.43
1.69
1.97
2.28
2.63
3.00
3.41
3.84
4.32
4.82
5.37
5.95
6.56
7.21
7.90
8.62
9.39
10.19
11.03
11.91
12.83
13.78
14.78
15.81
16.89
18.00
19.15
20.34
21.57
22.84
24.14
25.49
26.87
28.29
29.75
31.24
32.78
34.35
35.95
37.60
39.28
40.99
42.74
3hr
1.00
1.17
1.37
1.57
1.80
2.05
2.31
2.60
2.90
3.22
3.56
3.92
4.30
4.70
5.12
5.55
6.01
6.49
6.98
7.49
8.03
8.68
9.15
9.74
10.34
10.97
11.61
12.27
12.94
13.64
14.35
15.07
15.82
16.58
17.35
18.14
18.95
19.77
20.60
21.45
22.32
23.20
24.09
25.00
25.92
8hr
1.00
1.15
1.31
1.48
1.66
1.86
2.06
2.28
2.51
2.75
3.00
3.26
3.53
3.81
4.10
4.40
4.71
5.03
5.36
5.70
6.04
6.40
6.76
7.14
7.52
7.91
8.30
8.71
9.12
9.54
9.97
10.40
10.84
11.28
11.74
12.20
12.66
13.13
13.61
14.09
14.58
15.07
15.57
16.07
16.57
1day
1.00
1.12
1.25
1.38
1.52
1.67
1.82
1.98
2.14
2.31
2.48
2.65
2.84
3.02
3.21
3.40
3.60
3.80
4.00
4.21
4.42
4.64
4.85
5.07
5.29
5.52
5.75
5.98
6.21
6.44
6.68
6.92
7.16
7.40
7.64
7.89
8.13
8.38
8.63
8.88
\\ *-*.
9.13
9.38
9.64
9.89
10.15
4 days
1.00
1.09
1.18
1.27
1.36
1.46
1.56
1.65
1.75
1.85
1.95 ,
2.05
2.15
2.26
2.36
2.46
2.57
2.67
2.77
2.88
2.98
3.09
3.19
3.30
3.40
3.51
3.61
3.72
3.82
3.93
4.03
4.13
4.24
4.34
4.44
4.55
4.65
4.75
4.86
4.96
5.06
5.16
5.26
5.36
5.46
1 mo
1.00
1.04
1.08
1.12
1.16
1.20
1.24
1.28
1.31
1.35
1.38
1.42
1.45
1.48
1.52
1.55
1.58
1.61
1.64
1.67
1.70
1.73
1.75
1.78
1.81
1.83
1.86
1.88
1.91
1.93
1.96
1.98
2.00
2.03
2.05
2.07
2.09
2.11
2.13
2.16
2.18
2.20
2.22
2.24
2.25
To use this table, find the line containing the appropriate
standard geometric deviation for any single averaging time (left
side). Prom that line, we may obtain either the standard geome-
tric deviation for other averaging times (left side) or the ratio
of maximum concentration at various averaging times to the annual
average concentration. (From Reference 2)
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24-hours or 1-year. The technique may be used also with non-project *
emissions for an estimate of background when upwind emission rates are
small compared with those in the area of concern. Wind direction does
not enter the calculation.
Downwind regional scale analysis: As one phase of the project
impact analysis, it is useful to determine whether the project's ^
emissions will have an appreciable effect outside the immediate vicinity '
of the project itself. One way to do this is to obtain the concentration I
of project emitted pollutants after they have travelled a considerable
distance downwind. If we define a "considerable distance" as the travel |
distance required for project pollutants to thoroughly diffuse throughout _
the vertical extent of the mixing layer, it can be shown that ten *
kilometers would be a reasonable minimum distance at which to determine It
the regional scale impact of a project. By treating the project emissions
as though they come from a single point (a reasonable assumption at a 10
kilometer distance), the well mixed concentration downwind of the project
may be obtained by use of the algorithm
C - TO? (8) I
C
where X is the desired downwind distance from the center of the project
site. Other parameters in the equation are as previously defined.
Formula (8) assumes, in addition to the vertical uniformity of pollutant 9
concentration, that the pollutant is distributed uniformly throughout >
an angular plume width of 22-1/2 degrees.
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EXAMPLE 5
Suppose we wish to estimate the regional impact of the project in
example 3 under conditions of a C stability category (a=0.113 and b=0.91)
and a northwest wind at 3 meters per second. If we use Formula (8) for
our computation and an emission rate (30x10 yg/sec) as in the example,
ft formula (8) may be written as
- _ 2.55x30xlC6
I
C = 2.55x50x10
SOOxSxlO4
where X has been taken as 10 kilometers. The calculation yields a con-
centration of 5.1 yg/m . If the background from all other sources were
estimated for the same downwind location, the project impact could be
^ compared for significance. If, for example, the background were calcu-
* lated as 714 yg/m as in examples 1 and 2, the project would be found to
contribute 5.1/714 or 0.71 to the ambient pollutant level downwind. In
a relatively source free area, the same project might assume a greater
I regional significance. If the regional scale impact is desired as an
^ average over a period of time involving a. number of wind directions, a
calculation may be made for the wind direction bringing project pollutants
1M to the downwind location in question, and the result weighted by the
frequency of occurrence of the applicable wind direction during the
I desired averaging time. Thus, if the wind is from the northwest ten
percent of the time in the course of a year, the regional scale concen-
9 tration at a point southeast of the project, as an annual average, will
be ten percent of the calculated value using a northwest wind since the
concentration will be zero for all other wind directions.
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Source-specific analysis: The final type of analysis which is use-
ful in quantifying the impact of a project is one which addresses elements
in the project source complex. Such elements might consist of individual I
road links, parking areas, freeway interchanges, project power plant
stacks, airport runways, aircraft engine test stands, etc. n/hatever the V
nature of the source, it may usually be categorized as either a point,
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EXAMPLE 6
Suppose we wish to estimate the impact of a parking lot's emissions
within the confines of the lot, on a picnic area 10 meters from the parking
lot boundary and in a residential area 1 kilometer from the boundary.
Assume that the parking lot is square, 100 meters on a side. Assume
meteorological conditions consisting of a D stability category (a=0.105
and b=0.83), a 2 meter per second wind speed and a parking lot emission
rate of 3x10 micrograms per second of carbon monoxide in the peak hour.
The average concentration of carbon monoxide within the confines of the
lot from parking lot sources alone may be estimated using formula (6) as
C =
= 12,571 yg/V(10 ppm)
The CO concentration 10 meters downwind of the boundary may be estimated,
using formula (4) and the same meteorological conditions, as
0.8x3xl06
Ixl04x2
100
0.105(1 -
»
(1-0.83)
0.83) (2-0.
83)
0.8x3xl06
Ixl04x2
no(l-0.83) _ 10(1-0.83)
0.105(1-0.83)
= 5004 yg/m (4 ppm)
Finally, the CO concentration 1 kilometer downwind of the boundary may be
estimated, using formula (9), as
r 2.08x3xl06xlOOQ-(1+0-83)
L 0.105x3
= 62.6 ug/m (0.05 ppm)
b. Line sources: If we wish to evaluate the impact of a line
source such as a road link carrying project traffic, either inside or
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outside the project boundaries, a line source dispersion model may be m
used. Based on the findings in reference 8, a suitable algorithm for
estimating the pollutant concentration in the vicinity of roads at grade
level may be derived in the form:
I
_
(10)
Usin
where Q. is the emission rate per unit length of the line (micrograms per Q
second per meter), cj> is the angle the wind direction makes with the road, m
X is the perpendicular distance from the receptor point to the edge of the
road and C and U are as defined earlier. The exponent, p, is the function
of stability category and may be given values of 0.30, 0.25 and 0.21 for
C, D and E stability categories respectively. Formula (10) should not be |
used for cut or significantly elevated road sections or in cases where the p
wind direction is within 22-1/2 degrees or less of the road axis. Refer-
ence 8 should be consulted for guidance in these cases.
EXAMPLE 7
0.25x8.65xlQ4xlO'°'25
2x0.5
= 12,161 ug/m3 (10 ppm)
210
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Suppose a private residence is located with its front windows 10
meters from the edge of a freeway (by the edge of the freeway, we mean *
the edge of the outside lane). Assume a D stability category (p=0.25), fl
a wind at an angle of 30 degrees to the road at a speed of 2 meters per
4
second and carbon monoxide from traffic emitted at the rate of 8.65x10 M
micrograms per meter of road per second. Formula (10) may be written as ^
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1
1
1
1
1
1
1
1
1
1
Two special cases of the line source situation are worthy of further
exposition. One of these is the case of an airport runway which is a line
source of finite length and with the wind frequently at a relatively small
angle to the line. The pollutant concentration at a point downwind of the
end of an active airport runway
the form
2.04Q
r -
L abU
where X, and X~ are the distance
may be estimated using an algorithm of
*
X~b Y~b
Xl X2
5S to the closest and farthes
(11)
t ends of the
runway, measured from the receptor point, and the other parameters are
as defined earlier.
EXAMPLE 8
Suppose the edge of a residential subdivision is located 100 meters
downwind of the active runway of a metropolitan airport. Assume a wind
speed of 3 meters per second down the runway under conditions of stability
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1
1
1
1
1
category D (a=0.105 and b=0.83).
Assume also that aircraft operations
on the runway, including taxi, takeoff and landing, utilize 2000 meters
4
of the runway with an emission rate of 5x10 micrograms per second per
meter. The concentration at the edge of the subdivision may
by writing formula (11) in the form
r 2.04x5x10^
0.105x0.833
= 7853 yg/m3
3 ICO'0'83 - 2100-0-83
(7 ppm)
be estimated
A second special case of the line source situation is that of the
urban street canyon. On the basis of evidence suggesting a helical air
*
When using this formula with airport runways, values of X, less than 100
meters may yield unreasonable results. 2n
-------
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circulation in the urban street canyon, a simple model has been developed
as outlined in reference 10. When the wind direction at roof level makes
an angle of greater than 30 degrees with the street axis, concentrations
of auto emitted pollutants may be estimated separately for the leeward m
(C,) and windward (C ) sides of the street using the formulas
7Q1 I
C = ^ 2 1/2 C12) *
1 (U+0.5)((xz+zV +2)
7Qx(H-z) |
Cw ~ WH(U+0.5) (13)
where H is the average building height, W is the width of the street
(building to building) and x and z are the horizontal and vertical m
distances from the receptor to the center of the modeled traffic lane,
as indicated in Figure 3. When the wind direction is within 30 degrees
or less of the road axis, the concentration at all points is better
represented by taking an average of the results of formulas (12) and |
(13).
EXAMPLE 9
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Suppose that carbon monoxide is emitted on a three lane street at
4
the rate of 6x10 micrograms per meter per second and we wish to estimate £
the concentration at a second floor window of an apartment house on the
leeward side of the street. Assume a rooftop wind of 3 meters per second, *
perpendicular to the street axis, a street width of 20 meters and an
average building height of 30 meters. Assume also that the edge of the
apartment building in question is 6 meters from the center of the nearest M
traffic lane and the window in question is 6 meters above the ground. The
concentration at the window resulting from emissions in the nearest lane
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windvard
W
leeunrd
U
Figure 3. Schematic di,gram of conditions in an urban street
canyon.
213
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is obtained by writing formula (12) in the form
C = 7x2xl04
1 (3+0.5)((32+62)1/2+2) V
3
= 4077 Ug/m (3.4 ppm) g
where one-third of the street emissions have been assumed for each lane.
The computation should be done separately for each lane, changing the
distance, x, each time. The results are then added to obtain the impact
from the entire street. If this were done, assuming 4-meter lanes, we
would, obtain a total of 8.36 ppm at the apartment window. At a similar
apartment window on the windward side of the street we would obtain:
r = 7x2xlQ4x24 *
w 20x30x3.5
equal to 1.34 ppm for each of the three lanes or 4.02 ppm from the entire
road. This means that under the conditions chosen, leeward concentrations £
are about twice the windward values. ^
c. Point sources: Two types of point sources merit discussion here:
ground level point sources and elevated point sources. The types of ground V
level point sources which we normally encounter in impact analysis problems
are usually small area sources treated as though their emissions emanated
from a point. Such cases may be handled nicely by using either formula _
(8) or formula (9). In the case of the elevated point sources, the analy- '
sis becomes a bit more complex and cannot be reduced adequately to one
or two simple algorithms, as has been done with the other source types
discussed so far. When a large elevated point source such as a power
plant boiler stack exists either on the project site or near enough to
affect the project site, its impact should be analyzed. A thorough and
214
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I
lucid description of analysis procedures for point sources is provided
f in reference 3. As a first approximation, an estimate of the maximum
ground level concentration to be expected from an elevated point source
* may be made by using figures 4 and 5 which are based on the assumption of
U a B stability category and a 2 meter per second wind speed as a "worst
case" for the meteorology.
Concentrations, Averaging Times and
I Recurrence Frequencies^
The ambient air quality standards promulgated by the federal govern-
| ment and by some state and local jurisdictions require that specified
M concentrations averaged over specified time periods recur no more than
a specified number of times per year (usually once per year). When
fl analyzing the air quality impact of a project, therefore, the analysis
must provide information on the specified concentrations, averaging times
P and recurrence frequencies specified by the standards.
^ Averaging times: Three approaches are applicable to obtaining the
* pollutant concentrations at the proper averaging times:
jB a. Averaged parameter method: In this approach, the analysis
procedures described earlier are applied using values for emission rates
£ and meteorological conditions which are considered as a mean over the
time period in question. In the case of a road analysis, for example, if
we want an 8-hour averaged carbon monoxide concentration, we would obtain
the emissions from an 8-hour averaged traffic volume on the road and
select a wind direction, wind speed and stability category which we con-
M sidered to represent an average over the 8-hour period. We would then
use formula (10) with the time averaged input parameters to obtain an
215
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Figure 4.
COMPUTATION SHEET
Point source impact computation sheet
(numbers in circles indicate previous entries)
Emission point code number 1
(reference project site plan)
Calculation of plume rise and concentration-source strength ratio
L
7
9.
10
Emission point orifice height above grade,
Orifice inside diameter
Gas exit temperature (at orifice) ,
Gas exit velocity (at orifice) ,
20
300
5
m
la
°X
m-sec'
Temperature difference parameter (1- (288 (3*))... 0.04
Buoyancy factor (2.4x(£)x(2)2x(5)) 0»-i£ m -sec
Distance to ground level max. cone. ((T)xl5)...... 300 m
Plume rise (l4. lx@1//3) 11.3 m
Effective stack height (©+©) 31.3 m
Concentration-source strength ratio (from Pig. 1) 70
-3
gm/sec
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Calculation of maximum ground level impact
Pollutant
source strength
gm/sec
Ground level maximum concentration c.alcuia-
ted as (10) multiplied by pollutant source
strength and in turn multiplied by the aver-
aging time conversion parameter...m. (^g/m3)
Averaging time conversion parameters
1-hr 3-hr 8-hr 24-hr 1-mo 1-yr
m=2.0 31=0.8 m=0.7 m=0.6 ra=0.3 m=0.1
ORGAKICS
PARTICUIATE
216
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217
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I
estimate of the 8-hour averaged concentration. This method will
generally be valid in the absence of large non-uniform variations in
the values of the input parameters during the averaging period.
b. Weighted sub -interval method: A second and more precise
method is to devide the time period over which the concentration is to «
be averaged into sub- intervals of time characterized by distinct and
different values of emissions and/or meteorological parameters. An
analysis can then be performed for each of the component sub- intervals I
and the resultant concentrations weighted and added to obtain the desired
time-averaged concentration. This approach is used when obtaining the
annual averaged background concentration at a point by considering the m
frequency weighted contribution of upwind sources in each individual wind
rose sector. Another application would be in obtaining the carbon
monoxide concentration from a road source averaged over an 8-hour period
spanning peak and off-peak periods.
c. Statistical methods: A third and relatively simple approach M
makes use of a statistically derived relationship between concentration
values at different averaging times as described in reference 9. The
relationship is based upon the assumption of a lognormal distribution of
pollutant values for all averaging times and requires for its use the |
standard geometric deviation for one averaging time (see Table 1) . In &
using the table, the procedure would be to perform an analysis of .
concentration for a specific averaging time for which the best input B
information is available and then obtain concentration estimates for the
other applicable averaging times by applying the ratios indicated in
the table.
218
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ff Recurrence frequency : In addition to obtaining concentrations for
appropriate averaging times, we must also find out whether the time
f averaged concentrations specified in the standards are exceeded, and,
if possible, how often. Two approaches are applicable to the recurrence
problem:
a. Worst case method: The simplest approach to testing for air
quality standard exceedance is to perform an analysis of the impact under
I conditions of emission and meteorology which are the worst conceivable
from an air quality standpoint. If the concentration specified in the
standard is not exceeded under such extreme conditions, we can reasonably
conclude that the source in question meets the requirements of the
standard. If, however, we find that the standard is exceeded, the ques-
tion of how often still remains to be answered. While the worst case
approach seems quite useful on the surface, a number of factors argue
against its use. The principal problem with the method is that the
m meteorological conditions associated with extreme concentrations are
often difficult to define, involving, in many cases, subtleties in the
microscale effects of structures, terrain features and localized
gradients in the meteorological variables. In addition, those meteoro-
logical conditions which have generally been associated with elevated
g* pollutant levels, such as stagnant, windless conditions and associated
thermally driven local circulations, are usually rather poorly represented
by the models.
b. Statistical distribution method: Probably the most useful
£ and most generalized of the simplified approaches to meaningful air
quality analysis is to make use of the characteristics of the lognormal
frequency distribution for time averaged pollutant concentrations as
I
219
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outlined in reference 9. In such a lognormal distribution, the logarithm
of observed pollutant concentrations have a normal or gaussian distribu-
tion. We may therefore define a standardized variable or "z-score" in
the form
z - (14)
where m and s are the mean and standard deviation of logarithms of a
sample of time averaged pollutant concentrations (e.g. , 1-hour averaged
carbon monoxide concentrations) and X is a single concentration value
in the sample. The quantity z, then, represents the number of standard
deviations between the median value and the value X and is associated with
the probability of exceeding the value of X. The relationship between
z and probability of exceedance may be obtained by referring to any
standard set of statistical tables. Formula (14) may be solved for X in
the form
X = (em)(eS)Z (15)
where e and e are the geometric mean (GM) and the standard geometric 0
deviation (SGD) , respectively, of the distribution of pollutant values,
and e is the base of the natural logarithms. If we rewrite Formula (15)
in the form
X = (MG)(SGD)Z (16)
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we can readily see that when pollutant values are distributed lognormally,
individual values, X, and the probability of their exceedance (represented
by z) are related through the geometric mean and standard geometric
deviation of the distribution. Detailed guidance for the application of M
the lognormal model to air pollution problems is given in reference 9.
Use of the model in land use planning situations is discussed in reference
220
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STANDARD GEOMETRIC DEVIATION
1.00 1.10 1 .20 1.30 1.40 1.50 1.60 1.70 1.80 1-90 2.00
ii.;
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1.51
1 . 60
i « 68
i . 7 7
1.85
i .9''
P . 0 2
2.10
P . i 9
2.27
2 . 3 6
2 .44
P . 52
P . 6 1
P . 69
P . 78
P. 8 6
? . 9 /)
3 . 0 3
3 . i 1
3 .20
3-R8
3 . 3 7
3 A ;s
'. i - '?
, > . ..i v i
3.6p
3 . 70
3 79
3 . '6 7
3 . 9 5
4 . 0 4
4.12
G .0''.
0 . } '>
O.P4
0.33
0 . 4 1
0 . A 9
007
0 . 6 5
0 . 73
0 . 8 i
0 . c> 0
0 .98
1 - 0 6
1 i 4
1 . P P
1 - 3 0
i 8 i
1 A 6
1 - 5 5
i « i )3
* *7 ,
A * .' *
1 .79
1 . ! , 7
i «9 5
P . 0 3
P . i r
P.PO
r\ -> y
f . r u
P . 3 6
P . A A
2 . :-P
P . 60
P . 69
r -' */
r , « / /
P . 0 5
2.93
3 . 0 1
3 . f ) 9
3 . 1 7
3 . P 6
, '; « . 'r ' i
3 A '1
8 . :.')
^-, -- r
. 'l W . ) I '
3 "> »'
3 . 7'i
3 . 8 3
3.91
3.99
0 .08
0 . 1 6
0 . P /i
0.31
0 .39
0 . A 7
0 . 5 5
0 . i' 3
0.71
0 . 79
0 . ( i 7
0.9/:
1 .OP
1 . 1 0
1.18
i . 2 '
1 . 3 /
i . /i '
1 ./<_>
1 » 8 7
i . '!>
1 . 73
1 . . . 1
i . .9
1 .97
2 -0 A
2. 12
2 . 2 0
P .;:'
(* ' i '/ '
2 ./-''
2 . :;"'
2 . 6 ' ;
P - 6 7
P . 7 f.
P, . '. 3
P.''l
P 99
3 .07
3 - 1 5
3 « /" '
3 « ,' ' '.'
.'' « ; -
, * ' ' i i
3 r ''
3..'.':
3 . '/',
3. 77
3 8 3
Table 2. Relationship between arithmetic mean on the left and geometric
mean in the body for various standard geometric deviations. Other values may
be obtained by corresponding movement of the decimal point right or left for
both arithmetic and geometric mean.
221
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STANDAJiD GEOMETRIC DEVIATION
I .00 I '10 1.20 1.30 1.40 1-50 1.60 1.70 1-80 1.90 2.00
5 - ( i
5 « 1
5-2
5-3
5- A
5 5
5.6
5 . 7
5 . 8
5 - 9
6 . 0
6 . 1
6 . 2
6 « 3
6 . /I
n « 5
6 « 6
r; . 7 '
6 . 9
7 . 0
7. j
7 °
7 . :-\
7 A
7-5
7.6
7.7
7.8
7 .9
r, . o
r; « i
\ » ( t
' ') * ,'>
f-i » ';
;j !"i
">''*
> ' /
r; ^ f p
{ ; * ^j
* 1 i
. . ".
9 . ','
1 ' A
9 . 5
9 . 6
9 . 7
9 . r.
9 . 9
s . ,'; p.
5 . L 0
. 5-20
5.30
5.40
5.50
5.60
5 . 70
5.80
5.90
6 . 0 0
6.10
6 . 2 0
6 . 3 0
6.AQ
6 . 50
6> 60
6 * 7*0
6.80
6 . 9 0
7.00
7-10
7.20
7.30
7.40
7 . 50
7 . 60
7.70
7.80
7.90
8-00
8 . i o
8-20
8 . 3 0
8 .40
8 . 30
8 . 60
8 . 70
8 .80
8.90
9.00
' . 1 1 >
9 .20
9 . 8 0
9 .AO
9 . 50
9 . 60
9 . 70
9.80
9.90
A .98
5 . 0 8
5.18
5.28
5.38
5.48
5-57
5-67
5 . 7 7
5 « 8 7
5 . 9 7
A . 0 7
6 . 1 7
6 . 2 7
6 . 3 7
6 /! 7
6 5 7
O ("> V
6-77
6 - 8 7
6 - 9 7
7 0 7
7.17
7 . 2 7
7 . 3 7
7 . 4 7
7.57
7 6 7
7-76
7 . 8 6
7 . 9 6
8 . 0 6
8 . 1 6
8 . 2 6
8.36
8 . 4 6
8 5 6
8 . 6 6
8 « 7 6
8 . 8, 6
o; . 9 6
1 > . ( 1 6
9.1.,
9 . 2 6
9 . 3 6
9 . A r>
9.56
9.66
9.76
9.86
A . 9 2
5-02
5-11
5.21
5-31
5-41
5 . 5 i
5-61
5.70
5.80
5.90
6.00
6.10
6.20
6-29
6 . 3 9
6. A 9
6 « 59
6.69
6 7 9
6 « 8 8
6.98
7.08
7.18
7.28
7.38
7-47
7.57
7.67
7 . 7 7
7 . 8 7
7.. 9 7
8.06
8 « i 6
8 . 2 6
8 . 3 6
8.46
8. 56
8-65
8 . 75
8.85
'-; . 9 5
9.05.
9 . i 5
9.25
9.34
9 . A 4
9 . 54
9 . 64
9 . 74
4.83
4.93
5.02
5-12
5,22
5.31
5 . 4 1
5.51
5-60
5 . 70
5.80
5.89
5.99
6.09
6«i6
6 . 2 8
6.38
6 .47
6.57
6.67
6 . 7 6
6 8 6
6 . 9 6
7 . 0 5
7.15
7.25
7.34
7.44
7.54
7.63
7.73
7.83
7.92
8.02
8.12
8- . 2 1
8 . 3 i
8 . xi 1
8. 50
8 . 60
8- . 70
8. 79
8 . ; .. ','
8.99
9.08
9.18
9.28
9-37
9 . 4 7
9.57
4 . 72
4.82
4.91
5.01
5.10
5.20
5.29
5.39
5 . 4 8
5.58
5.67
5.76
5 . 8 6
5 . 9 5
6.05
6 .14
6.24
6 . 3 3
6. A 3
6.52
6 . 6 1
6.71
6.60
6.90
6.99
7.09
7.18
7.28
7 . 3 7
7 . x,1 7
7. 56
7.65
7.75
7.84
7.94
8.03
8.13
8.22
8.32.
8.41
8 . 50
;,,r,f)
f. . 69
8 . 79
8 . o 8
8.98
9 . 0 7
9 . i 7
9.26
9 . 3 6
4.61
4 . 70
4.79
4-88
4.97
5.07
5.16
5-25
5.34
5.43
5.53
5 . 62
5.71
5.80
5.89
5-99
6 « 0 8
6«17
6.26
6 « 3 6
6 . X) 5
6 . 54
6-63
6 . 72
6-82
6-91
7.00
7.09
7 . i 8
7.28
7 . 3 7
7.46
7.55
7 . 6 5
7.74
7.83
7 9 2
8-01
8.1 i
8-20
8 . 2 9
8.3;;
8 . /i 7
8 . 5 7
8 « 66
8.75
8.84
8.93
9 . 0 3
9-12
4.48
4. 57
Xi . 6 6
4.75
4.84
4.92
5.01
5. 1C
5.19
5.28
5 . 3 7
5 . X; 6
5.55
5.64
5 . 73
5-82
5 . 9 1
6 . 0 0
6.09
6 .18)
6 . 2 7
6 . 3 6
6 Xi 5
6. 5 A
6.63
6 . 72
6.81
6.89
6.98
7.07
7 . 1 6
7 . 2 5
7 . 3 X)
7. A3
7.52
7 . 6 1
7.70
7 . 79
7-38
7.97
8.0 6
> ' * I . *
;' . r:X;
8.33
8.A2
o 5 i
8 60
8 69
8 . 76
8-86
4.34
4.. A 3
4 . 52
4.60
4 . 69
4 78
X-i . 8 6
4 . 9 5
5.04
5 . i 3
5.21
5 . 3 0
5.39
5 . 4 7
5 . 5 6
5 . 6 5
5. 73
5 . < o 2
5-91
5 . 9 9
6> « 0 8
6.1 7
6 2 5
6 . 3 X.
6 . Xi 3
6 52
6 « 60
6 . 69
6 73
6 . 1', 6
6 . 9 5
7 . 0 X|
7.12
7.21
7.30
7.38
7 . X: 7
7.56
7 . 64
7.73
7.82
7.90
7.99
8 « 0 c
8 . 1 7
8.25
8 . 3 Xj
8.43
8.51
8.60
4 - 2 1
X; , 2 9
4.38
4 . 4 6
4 54
4.63
4.71
4 6 0
4.88
4 9 6
5 . 0 5
5 . i 3
5-22
5-30
5 . 3 6
5 . 4 7
5 5 5
5 . 6 Xi
5. 72
5 . 6 1
5.89
5 9 7
6 « 0 6
6 . 1 4
6.23
6 3 i
6 . 3 9
6-48
6.56
6 . 6 5
6 73
6 . 8 1
6.90
6.98
7 . 0 7
7 . 1 5
7 . 2 4
7.32
7.40
7 Xi 9
7 . 5 7
7 6 6
7 . 7Xi
7-82
7 . 9 1
7.99
8.08
8 . 1 6
8.25
8.33
X: . 0 7
A . i 5
Xi . 2 3
4 . 3 1
4.3,9
4 . A;^
4 . 5 6
4. 64
4 . 72
4 . nO
X: . 8 6
X; . 9 0
5 0 5
5 > 1 3
5 ? 1
5-29
5 :, 7
5 . A -,
5. 53
5. 62
5« 70
5 78
5-^6
5. '.''4
6-02
6. 10
6 . i 9
6 2 7
6 . 3 5
6. A 3
6 5 1
6. 59
6 . 6 7
6-75
6.84
6 « 92
7-00
7 « i j 8
7 . I 6
7 . 2 4
7 - 3 2
'/ . 'i 1
7- A .
7 5 7
7.65
7. 73
7. ''51
7. 89
7.98
8-06
3 . 9 3
A .01
4.09
4.17
4 . 2 5
4 . 3 3
XI.AO
X; . Xi ;;
4.56
X) . 6/'
4 . 72
4.30
Xi ."&8
4.95
5. 03
5 . 1 1
5 . : 9
5 '" 7
5-35
5 X; 8
5 . 5 1
5. 58
t- * -
5. 7 A
t_' 'y o
. i ' ' J / j
5 . r; o
5-9,8
6 . 0 6
6.13
6-21
6 . 2 ;
6 . 3 7
,% . /, r,
6.55
t " * t ; I
r, . r- : ,
6.76
A . 8 Xi
6. 92
7.00
7.08
* 7
. *
7 . 8 1
7.89
7. A 7
7 . ! 5
7.65
7.71
7 . 79
GEOMETRIC MEAN
222
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4. Relationships between variables are found in Tables 1 and 2.
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EXAMPLE 10
Suppose that the 1-hour averaged values of carbon monoxide observed
in the course of a year have a geometric mean of 4 ppm and a standard
geometric deviation of 2, and suppose we wish to estimate how often the
federal 1-hour standard of 35 ppm was exceeded in the course of the
V year. We may rewrite Formula (16) in the form
35 = (4)(2)z
Solving for z, we obtain z=3.1 which equates to a 0.2% exceedance rate.
This means that for the given distribution of 1-hour averaged values,
the standard value of 35 ppm was exceeded 13 times out of 8700 1-hour
«
periods in the annual sample.
Analysis Techniques for Reactive
Pollutant Species
Currently there exist no simplified techniques for handling the
problem of chemical transformations in the atmosphere. In fact, even
the sophisticated modeling techniques which have been developed are
still somewhat experimental and not yet suited to generalized applica-
tion. The modeling techniques which we have just described are intended
for use with the primary pollutant species actually emitted from the
sources and do not account in any way for chemical transformations which
take place in the atmosphere between source and receptor. Most local
0 impacts tend to be related to primary rather than secondary pollutants.
M Since there are standards for secondary pollutants such as oxidant and
nitrogen dioxide which are formed by such chemical transformations, we
223
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I
must have methods alternative to the techniques we have discussed in order
to address ourselves to the impact of projects in terms of these secondary
pollutants. In this section we will discuss a few such methods. It is
the author's feeling, however, that few projects will be large enough to
cause a secondary pollutant impact in and of themselves. Such impacts,
when they do occur, tend to be distant from the source.
The substitute standard method: In the case of oxidant, lack of a
deterministic relationship between oxidant precursor emissions and
oxidant concentrations has led to the promulgation of a substitute or
guideline standard for one of the primary pollutants, non-methane hydro-
carbons, which is involved in the oxidant producing chemical reactions
and is considered by many to be the controlling reagent. One method of
handling the oxidant problem, therefore, is to model non-methane hydro-
carbon dispersion using the techniques we have described and to compare
the resultant concentrations to the substitute standard. The assumption
is that compliance with the substitute standard will assure compliance
with the oxidant standard as well.
The ratio method: In the case of the oxides of nitrogen, emissions
from the source are usually given in terms of total oxides of nitrogen
and consist mainly of nitric oxide and a lesser amount of nitrogen
dioxide. Chemical transformations in the atmosphere convert much of
the nitric oxide to nitrogen dioxide, the rate and amount of conversion |
depending on a number of factors which are difficult to account for in a
straightforward manner. In view of this, there are two ways in which we
can attempt to account to some extent for the conversion. One method is
to model the dispersion of total oxides of nitrogen using the techniques
we have discussed and to assume that the ratio of nitrogen dioxide f
224
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concentration to that of total oxides of nitrogen is the same as the
ratio obtained from data taken at a nearby air monitoring station.
Another is to simply assume that the emissions from the source are 100
percent nitrogen dioxide. The latter approach will usually over-estimate
I the nitrogen dioxide concentration which may be considered as a safety
M factor favoring air quality.
The proportional trend method: If we are interested only in the
comparison between impacts in various future years or between alternative
land use strategies in the same and/or future years, a variation of the
| ratio method may be used. In this case, we simply compare the modeled
« concentrations of the primary pollutants and assume that the concentrations
of the secondary pollutants will be in the same proportion. Thus, if
one strategy yields twice the concentration of non-methane hydrocarbons
or oxides of nitrogen as does an alternative strategy, we may assume that
| the concentrations of oxidant or nitrogen dioxide will also be in the
proportion of 2 to 1.
Regional Modeling Applications
Throughout this presentation, we have concerned ourselves primarily
with the impact of individual projects such as shopping centers or parking
lots. The same techniques, however, may be used to model extensive
source configurations such as regional land use or transportation plans.
In doing this, we simply divide the source area or region into a number
| of grid squares as described in reference 4 and treat each grid square
M as an individual area source. The impact of each grid square's emissions
upon a given receptor may be modeled using the techniques discussed
earlier.
225
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Model Accuracy and Model Tuning _
The gaussian modeling techniques which we have described have been *
found to yield reasonably accurate estimates of concentrations resulting
from point and line source emissions on an ensemble averaged basis. That
is, if we were to measure the actual concentrations on a large number of
days characterized by a given set of emissions and meteorological condi-
tions, we would expect the average of all the observed concentrations to
be estimated rather closely by the model. An individual observation,
however, might differ significantly from the prediction of the model,
typically by a factor of 2. The difference between estimate and observa-
tion usually decreases with longer averaging times so that annual averages
are typically within 10 to 20 percent of observations if the modeling is
carefully done. Spatial averaging also increases the accuracy of the
modeling so that a modeled estimate of the concentration averaged over a
square kilometer can be expected to agree more closely with the observed I
concentration than a modeled estimate of concentration at a given point.
To be on the safe side, as far as air quality is concerned, in view of
the factor of 2 mentioned above, we might at least entertain the possibility
that a concentration might occur which is twice that which we estimate
with the model or similarly that the frequency of exceeding the standard
might be twice that which we expect. In augmenting our modeling estimate,
however, we should be careful not to exceed values which have actually |
been observed in situations similar to those assumed in the model. M
Even if the assumptions of the dispersion and statistical models
were realized in every detail, we would not expect even the ensemble
averages of observation and prediction to be in perfect agreement. Such
agreement is precluded by a variety of factors such as instrument f
226
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I
accuracy, the inability of monitoring sites to represent spatially
I
averaged concentrations and the fact that certain depletion mechanisms
such as chemical and gravitational deposition and chemical transformation
have not been and, in fact, could not successfully be included in the
| models. Since there is no way of successfully separating the error due
£ to these sources from that due to inadequate modeling assumptions, it is
logical to deal with the residual error from all sources by means of an
empirical or tuning adjustment. This is done by using the model in an
area or location for which monitoring data is available and comparing
| the modeled and observed concentrations under the same conditions of
M emissions and meteorology. On the assumption that the observation is
correct, we may then adjust the modeled estimates by a factor necessary
fl to bring the estimates and observations into agreement. The tuned model
may then be used with greater confidence in situations where monitoring
jj data is not available.
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REFERENCES CITED
1. Gifford, F.A. and S.R. Hanna, 1972. Modeling Urban Air Pollution,
Atmospheric Environment, Vol. 6, Pergamon Press, London. |
2. User's Guide for the Climatological Dispersion Model, EPA Publication M
No. EPA-R4-73-024, December, 1973.
3. Turner, I).II. , 1969. Workbook of Atmospheric Dispersion Estimates,
LiPA Office of Air Programs Publication No. AP-26.
4. Thuillier, R.H., 1973. A Regional Air Pollution Modeling System for
Application in Land Use Planning Studies, Bay Area Air Pollution
Control District Information Bulletin 5-17-73. |
5. tiolzworth, C.C., 1972. Mixing Heights, Wind Speeds and Potential for ^
Urban Air Pollution Throughout the Contiguous United States, EPAI
Office of Air Programs Publication No. AP-101.
6. Robinson, E., and R.C. Robbins, 1968. Sources, Abundance and Fate tt
of Particulate Atmospheric Pollutants, Stanford Research Institute
No. 6755.
7. , 1971. Emissions, Concentrations and Fate of Partial- g
late Atmospheric Pollutants, Stanford Research Institute No. 8507'.
8. Beaton, ct al., 1972. Air Quality Manual, California Division of
Highways, Sacramento, California.
9. Larsen, R.I., 1971. A Mathematical Model for Relating Air Quality
Measurements to Air Quality Standards, EPA Office of Air Programs 8
Publication No. AP-89.
10. Mancuso, R.L. and F.L. Ludwig, 1972. User's Manual for the APRAC-1A |
Urban Diffusion Model Computer Program, Stanford Research Institute
No. 8563.
228
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APPENDIX A
A Note on Formula Derivation
I
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The modeling algorithms which we have suggested for use in estima-
ting the air quality impact of projects have been presented without a
great deal of information relative to their derivation. It is the
purpose of this short appendix to indicate the manner in which the
formulas have been obtained for those who might be interested in a more
critical assessment of their validity.
Formula (1), the box model formula, is derived by assuming that a
column of air with unit area and a height equal to the height of the
m mixing layer moves across a source area with the speed of the wind. It
m is further assumed that pollutants emitted into the column as it moves
are thoroughly mixed between the lower surface and the top of the mixing
layer. With these assumptions, the concentration in the column, when it
reaches the downwind edge of the source area, is obtained by multiplying
| the emission rate into the column (Q/A) by the time the column spends
in the source area (L/U) and dividing by the height of the mixing layer
* (H).
I Formulas (4) , (6) and (7) are derived on the assumption that the
source area has a uniform emission rate and that the area source can be
| treated as though it were composed of an infinite number of line sources,
^ one next to the other. With this assumption, the concentration at a
downwind receptor may be obtained as the sum of the concentrations pro-
I duced by the individual line sources comprising the uniform area source.
229
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The algorithm for concentration downwind of a ground level line source is
given in reference 3, page 40 as
I
C = - (A.1}
(27T)i//azU
where q is the emission rate per unit length of the line (gm/m-sec) and
a is the standard deviation of the plume, in the vertical, at the
I
distance of the receptor. Integration of this formula (A-l) from one
end of the area source to the other, after substituting for a using I
Formula (5) , will yield formula (4) . Averaging of upwind line source
contributions for all receptor points within the area source, via a
double integration of formula (A-l) as outlined in reference 5, will yield
formula (6). See Figure A-l.
Formulas (8) and (9) are derived on the assumption of a point source
plume with uniform concentration across the width of the plume (assessed
to be 22-1/2 degrees) and a gaussian distribution in the vertical I
(reference 3, page 38). Formula (8) makes the further assumption that M
beyond 10 kilometers, the plume also has a uniform concentration between
the ground and the top of the mixing layer. See Figure A- 2.
Formula (10) is derived as indicated in reference 8 by treating a
street or highway as a line source with the wind at some arbitrary angle |
(j) to the road axis. The formula for the concentration downwind of such
a line source is simply Formula (A-l) with the sine of the wind angle in
the denominator. Formula (10) is a modification of these line source I
formulas based on the assumption of initial mixing on the road due to
the turbulence created by the cars and based also on empirical studies |
conducted by the California Division of Highways.
230
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1
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Formula (11) is obtained by treating a line source as a series of
point sources, one next to the other, and summing the impacts of the
| individual points downwind by integrating formula (9) over the length
_ of the line.
Finally, formulas (12) and (13) are taken from reference 10 where
flj they are given as the result of an empirical study.
The foregoing is but a thumbnail sketch of the derivation of
formulas used in our presentation. A thorough familiarity with gaussian
_ modeling obtained by a study of the cited references will aid greatly
in an understanding of the reasoning behind the techniques.
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APPENDIX B
A Summary of Formulas
The following is a summary of line and area source formulas con-
tained in the foregoing paper. Constants are non-dimensional so that
any set of consistent units may be used in the formulas. If micrograms,
meters and seconds are used as units, as is suggested in the definition |
of variables, concentration estimates will be in the units of micrograms
per cubic meter, units which are readily comparable with air quality
standards.
Formulas may be used for any averaging time (e.g., 1-hour, 8-hour,
24-liour, annual average) provided that meteorological conditions and |
emission rates are appropriate to the averaging time used. Concentrations
for longer averaging times may be calculated as the average of concentra-
tions for a series of shorter averaging times. The use of wind speeds of
less than 1 meter per second and extreme (A or F) stabilities will result
in questionable results and such use should be avoided. The validity of |
the parameterization of complex source configurations as points, lines .
or areas will generally increase with distance from the source.
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Summary of simple formulas for the approximation of line and area source impact
|.n _ QL
Al n
A fnr
.M liU
I,** Q/*\/V 1 1 b ) v ( 1 ~ b ) ^
CO ,, O.OQ(A2^ ' ~ A]_ \ ')
_j A 2 \ . S2
3 , ,
g AUa(l-b)
| £ A, n = 2.55Q
w
S HUXC
,_. . ce: u
^Hk HM
^1 '~>
Q -(1-fb)
IP CO A Ji p £. U j *&X(2
10 Km)
for small area sources with centers
less than 10 kilometers from
receptor (Xc ( 10 Km)
for average concentration within
the boundaries of the area source
(mobile receptors)
I-P
0 . 25QjX]_
J_jl r ^^
S Usin0
1
.. J-lt v^ __^______^___^___
I1^ , TT
H abU
S
P 7Qi
o 1.3 n -
1 .(U+0.5)((x2+z2)V2 + 2)
- ^ Tj4 p 7Q!(D-Z)
| WD(U+0.5)
Definition
Q = emission rate of pollutant
(micrograms per second)
Qj = emission rate per unit length
of line (micrograms per meter
Iper second)
,
U = wind speed (meters per second)
IL = Alongwind dimension of area
source (meters)
*Note: The constant a has the dimension
length (1-b)
Formulae A- 3 and A- 4 assume a
plume width of 22-1/2 degrees
1
for line sources (roads) with
receptors located laterally
for line sources (runways) with
receptors located longitudinally.
Wind parallel.
for leeward side of street canyon
(wind angle ) 30 deg. ) Do separate
computation for each lane.
for windward side of street canyon
(wind angle )> 30 deg. ) Do separate
computation for each lane.
of Variables
X, and Xp = distance to closest and
farthest boundaries of area
source with respect to the
receptor, (meters)
X = distance from receptor to center
or small area source (meters)
H = mixing height, (meters)
W and D = width and depth of street
canyon (meters )
z = height of receptor above street (meter)
a and b are stability constants
x = distance to center of closest
traffic lane
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ELEMENTS OF AN ADEQUATE IMPACT PRESENTATION
Ralph A. Mead
Introduction - NEPA and CEQA
* The National Environmental Policy Act, and similar laws in many
states, require the environmental impact of various public (and in some
states private) developments and other actions to be described in
I detail. The basic intent of such legislation is to require a "full
disclosure" of anticipated impacts, and the legislation has been
successfully used by environmental groups to halt or delay action in
cases where the environmental impact report or statement (EIR) fails
to spell out the impact completely. Careful preparation can avoid
making the EIR an easy target for litigation and more important, can
help focus the attention of the public and the decision makers on the
significant impacts.
While it is theoretically possible to prepare an "Air Quality
impact analysis" separate from the EIR, it is infinitely more sensible
to integrate the two. An EIR will include necessary descriptive and
analytical elements, aside from the technical Air Quality analysis,
which is essential for any informed judgment about Air Quality impact.
The Air Quality analysis may or may not be prepared as a separate
document, depending partly on local legal requirements; in substance,
however, the two are interwoven. Especially where (as in California)
a comprehensive EIR requirement exists for private as well as public
I
projects, the reviewer of an air quality impact analysis should have the
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benefit of a contemporaneous EIR. (Arguably, certain specialized studies, f
e.g. flora and fauna, could be kept at a generalized level or omitted for
air quality review purposes.) I
It is sometimes maintained that individual projects can be analyzed
for air quality only in a broader planning context. While there is some |
merit in this statement, it is nevertheless true that most air quality «
impacts, especially local ones, can be defined regardless of the breadth *
of the planning framework. Both viewpoints are important, but the need
for a broader context should not be accepted as an excuse for avoiding
analysis of major projects. J
A great deal of controversy surrounds the question of regulation
of indirect sources. While this is a matter of considerable interest,
it is not the subject of this paper. Whether and to what extent indirect
sources should be regulated depends on a set of judgments about the
significance of air quality impacts and the role of air quality in the I
value system of the people and their representatives. Such judgments are
partly technical, partly political and partly legal. It is not necessary
to debate these complex questions in order to discuss the elements of an
adequate impact presentation, but the readers are invited to pursue them
on their own. I
Description of Existing Conditions I
Three aspects of existing conditions are fundamental: meteorology,
air quality and land use-transportation patterns. A description of |
regional meteorology is important, and it should be concise and relevant. _
A common failing of EIR's is that there is page after page of meteorologi-
cal data and comments of little or no significance for air quality, while fl
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the succeeding sections on impact are quite sketchy and skimpy. Emphasis
should be placed on parameters such as wind speed, inversion height and
Jj atmospheric stability which are paramount for air quality. On the local
scale, available data should be utilized, but very often such data does
not exist on a systematic basis for local areas. The informed judgment
of a qualified meteorologist is far better than the guess of a non-
meteorologist based on minimal local data. Professional judgment is
also essential in evaluating the role of localized topography; superficial
judgments in this area are common, due to a lack of understanding of the
relationships between topography and meteorology.
Existing and historic air quality data may be obtained from air
pollution control agencies and sometimes other sources. Such data,
gathered at fixed monitoring stations, is of course subject to qualifi-
cation and interpretation. Like all statistical data, it is subject to
misuse, whether knowingly or unknowingly. The analyst should relate the
air quality data to federal and state standards, which require:
a) that these standards be set forth in summary form and
b) that specific relationships be drawn for standard-related
pollutants in terms of averaging times.
Monitoring station data must also be adapted to the project site,
which can be done in several ways. Reliance may be placed on the
opinion of a competent meteorologist familiar with the area. Site
monitoring may be performed, although an adequate monitoring program is
technically difficult and may be expensive. Air quality modeling is
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another possibility, again demanding specialized competence, and requiring
substantial input data; modeling for the site has the advantage of
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facilitating comparison of existing air quality with projections for I
future years.
Existing land use and traffic information in an EIR will normally |
be found outside of the air quality section. The important consideration _
for air quality is that this information be comparable in geographical
area, scale and level of detail to similar data for future years as
discussed below. Particularly important are traffic volumes on major
roads and location of sensitive receptors. I
Project Description
If an EIR is being prepared concurrently with the air quality
analysis, a project description will be available. This description 8
(or one prepared specially for the analysis) must contain information
useful for air quality analysis, and should not be accepted uncritically.
Project land uses should be expressed in terms related to their I
pollutant emissions characteristics. Since automobile emissions are of
primary concern, land uses should be given in units amenable to standard |
trip generation analysis, e.g. gross floor area of commercial space, «
number and type of dwelling units, number of students, parking area, etc.
Roads to be built as part of the project should be shown in
detailed fashion, and parking areas, entrances and exists should be
similarly detailed. Circulation and parking patterns are of major |
importance for automobile emissions; avoidance of congestion within and
surrounding the project is an objective for air quality as well as traffic
engineering. I
Relevant operational characteristics of the project should be
described. Hours and days of operation will be of interest, particularly |
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I as compared with traffic peaking patterns. For point sources, detailed
operational data will be needed, and usually required by the local air
I pollution control agency.
Any sensitive receptors to be included in the project must be
specifically located and described. The term "sensitive receptor"
includes any location or facility where health effects are especially
pertinent because "sensitive" elements of the population will be present
I for extended time periods. At a minimum, this would include hospitals,
M nursing homes, retirement homes, schools, playgrounds, single family
homes and family-oriented multiple dwellings.
I The phasing and the construction schedule of a project are directly
relevant to pollutant emissions because of increasingly effective auto
P exhaust controls in the years ahead. For a multiphased project this
_ factor can be of crucial importance. For example, assume that an
* office complex is going to be built in three phases extending over an
I eight-year period, with the first and largest phase scheduled for
completion in 1976. It is quite possible that one or more air quality
j| standards will be exceeded in 1976 and for several years thereafter,
_ while at completion of the entire project in 1982 no standard will be
* exceeded. If the phasing is inadequately treated in the project descrip-
tion, the air quality analysis will be incomplete and the impact will be
mis-stated.
I In describing the project, care should also be taken to specify
_ features to be built as part of the project which will facilitate further
development by either the project sponsor or other adjacent landowners.
Such "directly associated development" may be presumed to have a high
probability of occurrence in the eyes of the developer or the locality,
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or both. For example, a city may require a developer to install oversized
water pipes to facilitate development of parcels lying beyond his project
area. While the timing of development of those parcels may be uncertain,
it is a reasonable assumption that they are expected to be developed; plans
may be available or it may otherwise be possible to take account of this |
development in the air quality analysis.
Project Traffic Study _
For almost any sizeable project, a detailed traffic study will *
be prepared independently of air quality considerations. The traffic
study will either be part of the EIR or an essential background document
to the EIR (assuming one is required); in any event it will be indis- I
pensable for project planning. In the absence of a detailed traffic
study it is generally impossible to perform an adequate air quality impact
analysis--a rather vital fact sometimes overlooked or ignored.
The requirements of a traffic study for air quality purposes do
not differ from those standards in traffic engineering and transportation
planning practice, and may be briefly described as follows. First,
traffic (trip) generation is typically based on factors derived from B
specific case studies in the state or region of concern, usually
conducted by the state highway department. Such factors will generally
be applicable unless the particular project or area can be shown to have
special characteristics justifying the use of other factors. Second,
traffic distribution procedures, i.e. distribution of trips by geographical I
zones or sectors, often rely on local, regional, or highway department
transportation planning studies, or in the absence of such studies, on
standard trip length frequency curves. At this stage of the analysis I
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"modal split" procedures are important (it should be noted that estimates
of transit patronage are frequently over-optimistic). Third, the traffic
assignment phase relates to assignment of trips to specific roads of "links"
of the traffic network, both within the project boundaries and beyond.
Assignment is generally made on a least time or shortest path basis.
Finally, the traffic engineer will examine the capacities of access
points, roads and intersections affected by the project in relation to the
traffic volumes projected for those locations. Average road speeds and
levels of service will be predicted. ("Level of service" is a technical
traffic term used as an index to the degree of congestion on a road.)
Where less than optimal traffic conditions are expected, recommendations
for road improvements are made. Such recommendations represent only the
opinion of the traffic consultant and, unless incorporated in the project
funding program or officially approved by the appropriate governmental
I agency, cannot be relied on by the air quality analyst to represent
reality.
Other Anticipated Local Development
In order for the reviewer, the decision-makers and the general
public to arrive at their own assessments of air quality impact, the
person or agency preparing the analysis must address the question of
expected development in the vicinity of the project at the time of its
_ completion (or maximum impact). In other words, the project will not
proceed in a vacuum. The local air quality will be determined not only
by the project itself, but also in part by other nearby projects (as
well as local and regional activity). The air quality impact of the
I project can be fairly assessed only if the significance of other
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anticipated local development is known. The geographical area within
which such other development should be described will vary to some extent
with the locale and the situation, but a one-quarter to one-half mile S
radius around the project boundary will normally be appropriate.
approval and funding. Others may be definitely planned, by public
agencies or private developers, for construction within the relevant time
period. These two categories--committed and specifically planned projects-- I
can be quantified in air quality terms in many cases. A third less well
defined category is "permitted" development, i.e. development permitted ||
pursuant to local zoning and other regulations; ordinarily this category
will not require quantification, but it should be described graphically
and verbally. I
For example, assume that a shopping center under evaluation is
due for completion in 1976, and that a large high-density apartment |
complex approved for construction across the street will also be finished »
in 1976. To proceed with analysis of the shopping center while ignoring
the apartment complex would not be appropriate. Similarly, new sensitive I
receptors, and new or modified roads, traffic controls and transit
improvement, committed or definitely planned in the vicinity within (|
the time period of concern, should be taken into account to the greatest _
extent possible. .
The burden of securing and utilizing this additional information
falls on the public or private organization preparing the air quality
analysis or EIR. However, the information should be available from |
local, state, and other public agencies--which are normally contacted _
for other data. The reviewer in turn can contact these agencies, if
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necessary, to verify the information. Obviously, the most detailed
information on "other anticipated local developments" will be for
earlier years; where there is a long time span until project completion,
_ the later data will tend to be sparser and less detailed.
I
Air Quality Impact Analysis
The core of the presentation is the technical, numerical analysis
m of air quality impact. The first task is to select an appropriate year
or years for which to estimate the project's impact. If construction is
I to occur within, say, a two year period, the year of completion is the
likely choice. If construction will take longer than two years, consider-
| ation should be given to selecting more than one analysis year. Desirably,
u the year of maximum expected impact should be analyzed--this may or may
not coincide with the year of completion. Consider for example a project
I in two phases, the first to be finished in 1977 and the second in 1980.
The greater impact will probably occur in 1977 (especially if the first
P phase is larger) because the effect of improved auto emission controls
« will be felt less in the earlier year. Regardless of the outcome of the
* analysis in such a case, the report will be more valid and informative if
ft both years are considered.
The calculation of project impact can take a number of forms. The
Research and Planning Section of the Bay Area Air Pollution Control
_ District has evolved a methodology addressed to three levels or scales of
impact: roadside, area-averaged and "regional." Aircraft emissions and
industrial point sources can be modeled independently and are not dis-
cussed here.
For roadside impact, peak and off-peak vehicular emissions are
1
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for each road, whether within or beyond the project boundaries, on which fl
project traffic forms a substantial part (say 10$) of total traffic
volume. Using a readily available line source model and "adverse-case"
meteorology, pollutant concentrations are modeled at roadside and at one
or more distances from the road; background concentrations are added.
This approach is used chiefly for carbon monoxide.
The area-averaged approach uses total emissions from the project,
defined as emissions from all line, point and area sources within one or I
more (one-kilometer) squares centered on areas of highest source activity.
Accepted Gaussian dispersion modeling techniques are used to calculate
annual average pollutant concentrations, which may then be converted
statistically to any desired averaging time. The result is averaged
pollutant concentrations over the one-kilometer square, representing the
project's impact on ambient air quality. Background concentrations are A
added to derive projected ambient air quality. This approach may be used
for any non-reactive pollutant. M
The regional impact on photochemical oxidant can be approximated
by treating total project emissions of hydrocarbons as a point source,
diffusing it downwind for ten kilometers, and comparing the resultant
concentration to the ambient background concentration of hydrocarbons.
While this is not a photochemical modeling process, it does give a «|
general idea of the magnitude of oxidant impact resulting from a single
source. It should be observed that over the time and distance required
for oxidant formation, this impact is rarely expected to be significant.
After project impact has been calculated, the analyst should I
calculate the impact of "other anticipated local developments" in the m
year(s) of concern. Where possible, this consideration should be
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quantitative; at a minimum, a qualitative assessment is called for.
Returning to the previous example (i.e., high-density apartments across
fj from a shopping center under review) the pollutant concentrations
g resulting from the apartments should be calculated, or if that is
impossible, a general idea of the magnitude of the problem should be
B given so that the reviewer or decision-maker has an understanding of
the situation.
I
Finally, background concentrations should be added to arrive at
_ total ambient air quality. Except in the case of particulates, back-
ground is often secondary to localized source concentrations, but can
v still be important. Projected background concentrations may be
extrapolated from existing ambient air quality data or modeled in
| various ways. The Bay Area Air Pollution Control District uses a
f projected regional source inventory to provide background distributed
over a fine grid. In general, air pollution control agencies are in a
M good position to supply background concentrations for the near term, or
these may be estimated through extrapolation. For the long term, the
f accuracy of background estimates is subject to greater error, but this
^ is equally true of all long-range projections.
* Having calculated project impact and added background concentra-
M tions and the effects of "other anticipated local development," the air
quality analyst can proceed to the interpretation stage. What does it
all mean? At this stage opinions may reasonably differ on some points,
v but it is the job of the person preparing the impact analysis to set
forth his professional judgment. The primary consideration is how the
A project's impact on air quality relates to federal and state air quality
standards, taking non-project sources into account. The key parameter in
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this respect (obtainable through statistical analysis) is the frequency
1
with which those standards are expected to be exceeded, on a climato-
logical basis. Comparisons "with" and "without" the project are valuable.
For some projects, another valid approach to interpretation little
used up to now, is to consider air quality impact in terms of exposure of Ji
sensitive receptors. For example, one could attempt to quantify the
exposure of sensitive groups in a residential project in terms of an index
like person/hours over the oxidant standard. The concept of impact on I
the project differs from the conventional concept of impact of_ the
project, but it is clearly an appropriate subject for analysis in the sense |
that without the project this impact would not occur. m
Finally, brief mention should be made of impacts during the con-
struction period. Except for large projects in densely built-up areas,
construction impacts will generally be tolerable, provided standard relief
measures (such as wetting down the site) are used. For the more severe y|
situations, especially where the construction period will be long, an M
attempt should be made to quantify the impacts, even though emission factors *
for construction equipment are acknowledged to be less than precise.
Mitigating Circumstances
I
Having stated the air quality impacts, the analyst can then present
information regarding the ways in which those impacts will or could be
mitigated. Experience in reviewing EIR's in California indicates that
this section of the report is frequently a "mixed bag" (at least where 8
air quality is concerned) consisting of desires, hopes, possibilities, ^
miscellaneous comments and at times, firm data. The following discussion
will consider a number of items often claimed to be mitigating circumstances. V
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Perhaps the most common category of mitigation includes planned
and projected actions of national, state or local governments. For
example, the air quality benefit anticipated from automobile emission
control devices is sometimes set forth in mitigation of adverse impacts.
Likewise, the prospect of better public transportation, or road
m improvements, is said to be a mitigating factor.
" Several comments are appropriate with respect to this type of
statement. First, some would say that true "mitigating conditions"
must be within the control of the developer; if not, the factors at
issue should really be a part of the impact analysis proper. Second,
« the timing involved before the control devices, transit, roads, etc.
actually come "on line" should be set forth, rather than simply stating
I that certain events will (or may) occur at some indefinite future time.
Third, just as the impact should be quantified, so should the mitigation.
p How much will control devices help, in any given year? What will be the
"modal split" between transit and cars when transit becomes a reality?
(Over-optimism is rampant in EIR's on this subject.) What will be the
M quantitative effect, on traffic volumes, speeds and patterns, of an
anticipated road improvement?
m Fourth and perhaps most important, the chances of the claimed
£> mitigating factors ever becoming reality must be soundly appraised.
' Will promised transit really happen--is the funding there? Will a
9 particular road really be widened within the next five years, or is it
a "paper project?" 'what do real-world studies show about the probable
effectiveness of auto emission controls? The degree of "proof" required
is a matter of judgment; but if the pollution impacts are likely to be
real, the mitigating circumstances must be real as well.
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Another "mitigation" statement found in many impact reports is that
I
air pollution will be increased in the vicinity of the project but will be
reduced overall in the locality or region. This reduction is usually
expressed in terms of "VMT"--Vehicle Miles Traveled. Such a claim, even
quality trade-offs, somewhat akin to saying "I'll fix your broken leg if m
you let me choke you." The localized impact is not mitigated, but is
allegedly offset by an improvement somewhere else. The problem here is
that "localized" air quality violations are not some second-class form of
air pollution--they are health-related effects measured by legally- P
established air quality standards. One cannot simply wish them away by *
pointing out reductions occuring elsewhere. *
Moreover, the claim of reduced VMT can rarely be sustained. New
developments generally cause an overall increase in vehicle travel and
air pollution, not a reduction. And the state of the art in "market |
studies" is such that although traffic attracted to a project can be
estimated and distributed fairly well, it is extremely difficult to make ^
defensible estimates of the effects of a project on remote traffic m
generators.
An example of true mitigation would be a change in proposed |
operational characteristics of a project, e.g. staggering work hours to
1
lessen congestion and distribute vehicular emissions over a longer time
period so as to decrease oxidant potential; or scheduling sports events ,fi
at times when stadium traffic will not conflict with peak hour freeway
traffic. Obviously there should be guarantees that these desirable J
things will in fact happen.
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Design and layout changes can also be legitimate mitigation
measures. Redesign of parking areas, internal circulation patterns or
entrances and exits is a promising avenue to reduction of pollutant
concentrations, especially for carbon monoxide. Building design and
placement can have pollution micro- effects, but to determine these
effects precisely requires an expensive and detailed study which is
rarely justified (wind effects might be a better reason to undertake
m a study of this nature) .
The amount, placement, and character of landscaping should not be
q| ignored, because levels of both particulate and gaseous pollutants
experienced at a receptor site can be mitigated by vegetation. Un-
' fortunately, the state of the art does not allow us to quantify these
effects reliably.
Finally, construction impacts of major projects may be mitigated
I'
if necessary, by such means as ensuring that construction vehicles do not
« congest nearby highways during peak hours, or even (in rare cases)
prohibiting or limiting construction activities on meteorologically
9 adverse days. However, it is a fact that construction impacts tend to
be given less weight in decision-making, partly because of the temporary
1'
nature of construction activities and partly due to uncertainties regarding
equipment emission factors.
^
I
Alternative Intensities, Uses, and Sites for the Project
f Federal and state environmental impact legislation require a
M discussion of alternatives to the project. The most important consideration
for the preparer of the EIR or similar documents is that the alternatives
V should be real ones. Little is gained by an extensive treatment of
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academic alternatives (although at times a brief mention of unreal «
alternatives may be useful simply in order to dismiss them); rather, a
detailed treatment of one or two real possibilities is much to be
preferred. Three types of alternatives may be distinguished: different
site; and different sites for the proposed use. .
It is obvious that the air pollution impact of a project will be
decreased if the intensity of development is reduced, whether it be a fl
shopping center, sports stadium or residential development. What may
not be so obvious is that a reduction in intensity can sometimes bring fi
about a disproportionately large decrease in pollution. For example, if _
the project would overload a major highway, a relatively small decrease
in project size might improve the highway's level of service substantially, W
causing nearby pollution levels to improve. Because less intense develop-
ment is frequently desirable for other reasons besides air quality, and m
is often subject to negotiation under local customs and zoning ordinances,
this kind of alternative can be realistic and should be explored and P
quantified. £
The question of altered layout was mentioned under "mitigating
circumstances," but is equally pertinent in this section. Through I
redesign of a project it is sometimes possible to effect substantial
reductions in localized pollutant concentrations. This might involve ]i
changes in roadways within and serving the project, better parking lot te
design, additional entrances, exits and the like; or altering the siting
of a "sensitive receptor" facility such as a hospital.
Alternative uses for the project site may be limited by zoning,
I
location or economic feasibility. Moreover, in some cases the air
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quality impact of an alternative use may not differ substantially from
what is proposed. But it is certainly conceivable for a realistic
alternative use to be demonstrably better (or worse) than the proposed
_ use because of differences in trip generation rate, "model split," or
traffic peaking pattern in relation to adjacent highway traffic peaks;
or because of the nature of the use as a sensitive receptor. These
factors should be quantified and converted into air pollution estimates.
The final type of alternative involves different sites for the
proposed use. If realistic alternative sites exist, the analyst can
compare these to the project site in terms of potential for public
transit, anticipated traffic volumes and congestion levels on adjacent
highways, air pollution impact on the proposed use viewed as a sensitive
receptor, local meteorology and topography, or growth-inducing effects.
Recent experience in the Bay Area indicates that for large projects
ft1 such as regional shopping centers and sports arenas, alternative sites
im are actively considered. For example, a major department store may
desire to locate within a general area and will negotiate for several
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sites simultaneously, but only one will ultimately be selected. In
this kind of situation a detailed comparison of the sites is appropriate.
Unfortunately practical problems can arise here, because a) additional
work is required for a detailed comparison; b) the project proponent
I
sometimes lacks control over data and timing for alternate proposals;
V c) the alternative site(s) may be located in another jurisdiction,
introducing the additional consideration of economic incentives by two
P or more jurisdictions vying for one facility.
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Nevertheless, a comparison of sites can be extremely important and (H
valuable. The challenge to the reviewing agency is to seek complete
information about alternate sites despite the problems cited, but without
imposing an unfair burden on the project proponent. ^
Growth-inducing Effects of the Project
The growth-inducing effects of a project are not a part of the air f|
quality impact analysis in the quantitative, location-specific sense used m
in this paper. Nonetheless these effects may be extremely significant
and should be addressed. A three-way classification of projects may be
useful here. First, there are projects which in themselves are negligible
polluters but which may induce growth, e.g. sewer and water projects. p
Second, many projects are both polluters in themselves (direct or indirect »
sources) and inducers of growth, e.g. some highways and industrial plants.
Third, other projects have little or no growth-inducing effects, regard-
less of their own pollution-emitting characteristics.
With respect to the second type of project, the EIR or air quality |
analysis should treat both the specific air pollution impacts and the ^
I
more general growth-inducing effects. For the first type, i.e., the m
"pure" growth-inducing project, only the more general approach to air
quality impact is possible.
Each of these contrasting approaches--the general and the specific-- p
has its own validity and its own applications. Statements about growth-
inducing effects assume greater meaning within an overall context of
planning and growth policy as related to air quality, e.g. an emissions
I
allocation program. The specific project impact analysis which is the
main subject of this paper can be carried out more-or-less independently I
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of a growth framework, and is too detailed to handle growth -inducement
questions. However, data on growth inducement is still important in a
| specific project context- -and can be handled in a qualitative, judgmental
g fashion rather than a quantitative, location- specific sense.
With this background in mind, we can proceed to consider some
questions about the nature of growth inducement. Vfliat kinds of land use
are apt to induce growth which affects air quality? Sewer and water facili-
jj ties, highways and industries have all been mentioned. Generalizations
^ are insufficient however; each case must be examined with respect to
location and local development patterns and plans. For example, a major
IB highway connecting an isolated development to an urban area might well
be growth- inducing because it would tend to "open up" the intervening
I land to development which would not otherwise occur. On the other hand,
fa new highway to improve service in an already developed area might
have a minimal effect on growth.
This raises an even more basic question- -what kind of "growth"
are we talking about? For air quality purposes, population growth with
m its associated automobile-serviced residential and commercial facilities
is of course important, but other parameters of growth are also relevant,
including land development patterns and vehicular travel. Locational
relationships are also vital. Consider a large residential project
proposed for a presently undeveloped area at the edge of the metropolitan
region. Questions should be asked (and answered) regarding the project's
locational relationships to employment centers, to roads and transit
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systems and to existing and planned sewer and water facilities.
the commuting patterns of the residents result in excessive
amounts of vehicle travel? Will densities be too low to support effective
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bus service or mass transit? Will the project require lengthy utility V
and road extensions which are themselves growth-inducing? Will the
project tend to induce extensive land development in area planned for g
open space and agricultural use or in an area susceptible to poor air ^
quality conditions? Viewed in light of these questions, even a residen-
tial development may in certain circumstances be seen to have substantial It
growth-inducing effects relevant to air quality.
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I AIR QUALITY IMPACT ANALYSIS
1
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PANEL DISCUSSION
QUESTION: How do you determine significant impact?
ANSWER: (Ralph Mead, Bay Area Air Pollution Control District) I don't
think your environmental impact report can do it in and of itself. At
1
w least as far as air quality is concerned, one way to look at it is to look
at the total emissions of the project as compared to total emissions in
the area in which you're modeling, or considering. At some point, some-
£ body has to pick a number or a percent and say that we feel that that is
significant. That's one approach. Another one is to say, does the
*' . project in and of itself cause an excess of air quality standards? I'm
M not suggesting that those are the only tests of significance. There may
be cases where something is significant and there is no excess of air
quality standards. Perhaps you're putting something where there was no
development before, and it's eating up 501 of the way to an excess of air
I quality standards. I think each professional and each agency is going to
m have to determine that, and most often on an individual case basis. That's
the only way I can answer it.
I QUESTION: I/ho determines significant impact?
ANSWER.: (R. Mead) In the first instance, the decision, or the judgment
on whether the impact is significant should be made by the preparer of
m the EIR. In California it will then be submitted to the city (or in some
instances prepared by city staff) and the city has to determine whether
they agree with that determination. The standards of the person preparing
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the EIR for what's significant may not agree with what the city reviewer
thinks is significant or what is city policy. In turn, that may not agree
with what a regional air pollution agency or other agency may consider
significant. I'm not trying to evade that question; we don't have any
hard and fast rules for what is a significant impact. It requires *
judgment, we're not discussing specific projects. M
(A member of the audience asks that a letter be read by the speaker.) _
The following are the comments of the air pollution agency relative to the *'
Draft Environmental Impact Report on the airport expansion as requested
by you:
The report indicates the total operations will be reduced from
330,000 passenger airline operations currently to 310,000 by 1985. There
may be questions raised on this estimated number of operations. And '*
we suggest that information in the regional airport systems study should
be carefully examined in so far as it discusses possible changes in
scheduling and the effect of the total number of operations and use of
element engines. That's point one. Point two: assuming a maximum of
310,000 operations per year, which is what they say, there will be a
decrease in emissions from aircraft by 1985, because of the lower number
of operations and the use of cleaner engines. Three: the report indi-
cates --and I would make a point here that again you're talking about I
certain assumptions, so you have to say whether you're making certain
assumptions and the reviewer has to say whether he's basinghis judgment
on those assumptions, and those assumptions can in some cases be questioned.
The report indicates that by 1985, twice as many vehicles will travel to
the airport as today, but that automobile emissions will be reduced from
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183 tons per day today to 38 tons per day in 1985. This should, or
would improve air quality by 1985 given those assumptions. Fourth: the
impact of auto emissions on air quality in the intervening years between
1972 and 1985 was not evaluated. That statement is saying, in my opinion,
* that the Impact Report was inadequate. Fifth: the impact of auto
emissions on air quality in surrounding local communities caused by
changes in the local traffic resulting from congested routes to the
airport was not evaluated for the 1985 period nor for the intervening
period of 1972-1985.
W I mentioned these points before--what I'm getting at is that we do
m not always say yes this is significant, or no, this is not significant,
as a single statement. First you have to have an adequate impact report
I before you can determine whether the impact is significant or not
significant. And I think that really is the more important point as far
as this course is concerned. If there has not been an adequate impact
mt report prepared, it is not possible to determine whether the impact is
significant. Then we talk about motor vehicle mixes during those years
from '72 to '85 in terms of vehicles being improved and auto exhaust
controls inproved over the years. Sixth, the proposed, projected increase
P in fuel requirements for heating purposes at the airport should be
« evaluated in terms of the impact on air quality based on fuels which will
be available during the period 1972-1985, specifically the use of high
A sulphur fuel oil for such purposes should be evaluated in terms of air
quality effects. You see, what we're saying in this letter, and what
p we're usually saying, is that we want a better job done, we need a better
_ job done in order to make any kind of judgments at all--let alone about
I
significance. Then we point out that a permit is required if the BTU
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heat in-put exceeds 10 million BTUs per hour, M
And lastly we mention that complex source permits may be coming along
from EPA and you'd better think about that, and then we say at the end, I.
it is not clear at this time if complex sources which have had substantial
work started prior to the extension of the district's authority to such f
sources, would be required to obtain a permit, '.{hich means we don't know _
whether this project or some other project would be grandfathered in
(grandpersoned in? grandparented in?), because we don't know what the
regulations will say as regards which projects will be grandparented in.
This'letter is an official letter which is a matter of public record, so, y
if that's what you wanted _
QUESTION: I had a question on a different point. I don't see how the
air quality impact analysis can be evaluated, in and by itself. For
instance, in this case the San Francisco Bay Area economy is dependent H
upon air travel, or connection in that way with other parts of the world.
Wouldn't you have to evaluate the project in relationship to if that
airport is not expanded, would it be necessary to build another one in
another portion of the Bay Area. If so, what would be the impact of ||
that on air quality? _
ANSWER: (Waide Egener) I think this is the point again of using a
systems approach, and in this situation we have a broader plan, and that IT
broader plan said--okay, we can accomplish certain environmental objec-
tives and yet fulfill our economic objectives if each airport adheres to
certain criteria and standards, so what we're looking for is not a _
justification of aviation, but a demonstration by whoever is doing the
report that the operator or the facility is capable of meeting the A
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' criteria and standards which are included in the overall plan.
QUESTION: I believe in this discussion there!ve been several points that
have been alluded to which I think are significant. One is just what
is significant, and what is an adequate report? It's been discussed very
* frequently, but I think it is all in the eyes of the beholder, and that
is the real problem that we have right now--what constitutes an adequate
report. The man who prepares it thinks it's the best report he ever
prepared. The sponsor thinks it's overdone, many times. The local agency
may have their own opinion. The regional agency has another opinion,
and finally the citizens who might be for or against the particular project
t have got another opinion, and it's all tossed into one great big mess,
if you want to call it that and sometimes it goes on and on--without any
real standards of what constitutes an adequate report.
ANSWER: (Herman Volk) I'd just like to say that I think it's possible
| to read any EIR that's written and make a good case for it not being
m adequate. I don't think you'll ever get an adequate EIR that suits
everybody--it's just not possible. I'd also like to make a point about
V determining significance of projects, and perhaps I could just point out
what we do in our agency when we receive these EIRs. We receive some-
P thing like 20 to 30 EIRs a month, and we have essentially two people that
M review them. They are farmed out to other people but essentially it's
two people. First of all in the sorting out process, we spend time
fl logging EIRs. We have to make some kind of a preliminary priority deter-
mination. We sit down, once a week, and we try to sort them out. Both
0 Ralph and I agree that when you get a freeway project or a highway project,
_ it's potentially a very significant project. It may not be so in all
I
cases, but potentially it's a significant project, and I personally
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consider all EIRs or EISs for highway projects as significant, particularly
if there are a number of miles of new road. Also, widening and inter-
changes can be significant. There are wastewater treatment EIRs that
are really significant. If there's an approval to put in a wastewater
treatment facility, it's growth. That's significant. There are shopping '*
centers: I view all regional shopping centers as significant, those are
ones with about 250,000 square feet. So a lot of the stuff that we get
is significant in our view in terms of what will be emitted as a result
of the activity that will be generated by it. On the other hand, you
may get a project that is much smaller than the community shopping center,
but it's located in a really poor air quality area. It's our view that tm
those should not be overlooked. That's also significant.
We just don't have the time to look at all these EIRs and EISs, un-
fortunately, and when we do look at these, and I want to make this per-
fectly clear (I never thought I'd say that...) but it's this, when we |
look at it--and this is a point that Vivian made, and Ralph made and George «
made: and that is that the air quality element by itself really doesn't
tell you much. You have to look at the traffic part, and the growth II
inducing aspect, as vague as that is, and as many red flags as that raises
every time somebody mentions it; in point of fact it must be considered; £
also, mitigation measures and alternatives are important. You have to look »
particularly at the air quality components of each of those related . *
elements, and how they relate. So what that means is that when we get an B
EIR we read it cover to cover. Now, there are meteorologists who may
look at the air quality part and there's a traffic engineer who looks
at the traffic, but essentially we review that damn thing cover to cover,
and I don't think you can make an adequate review without doing so. And
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I I think we do a pretty good job of it. And another point is that we
planners have been with an air pollution agency now--I've been there for
£ a year, Ralph has been there 3 years. It's a 220 person organization
_ that we're trying to move in our direction, supposedly, and without
* compromising any goals we may have. You really have to walk on eggshells
and you have to weigh everything you say and consider it. And I just
get a sense that there's a feeling here that somebody may not be doing
an adequate job, and I suggest, I throw the ball back to you, that if
you feel an adequate job isn't being done, then say something at this
meeting, get up and protest. I think we are all in our own way really
A doing an adequate job. When I talk to local planners, and I talk to a
lot of them, I make known what our concerns are, and they make known
what their concerns are to me, and I think we're really talking at the
same level and I think we really are moving in the right direction. And
9 it's really difficult to say things perhaps so bluntly as some would
m like them to be said; of course somebody could always say, okay how do
you really know what the impact will be, did you really do a study, is
it really adequate, and I guess that's correct.
QUESTION: itfhat happens next in the scenario? You've made comments of
P informational inadequacy and that generally appies to a draft impact
statement...and then they go on with a final--Ito you get'another crack
at it? Would you want another crack at it? What did you do at this
stage? Do you ever make a determination once you feel they've done
the most complete job they could as to whether it is significantly
0 adverse or not? In other words, do you take a position at a final point?
ANSWER: (Herman Volk) In my opinion we don't take a position on as
many projects as we should. Also, I think we really have to follow our
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comments all the way down the line, and if we really want to get some-
thing done we can't just mail a letter in and assume we did our job.
To some extent that happens--you know we can only control so much. We're
only willing to putwell I guess it's our jobs on the line--to a limited
extent. I think there's real need to follow all comments through and one £
of the points I try to make known to anybody who listens is that we «
really have to go out there and start talking to people and say we really
believe in what we say! We really think there's an adverse air quality ft
impact, and we're serious about it. however, there's a tendancy, perhaps
because we're overworked to some extent, to avoid meetings, not to follow ^
things through and to assume they are followed through. To some extent ^
I've been unhappy with the follow-up on reviews. Very often it's not me *
who follows it through, it's somebody working above me. Hopefully some I
of that will change, but it's a matter of building up confidence in your
ability on the lower staff level, that's the position I'm in.
QUESTION: ...
ANSWER: (Herman Volk) What I'd like to do is critique the EIR that was "
summarized on the hand-out. (Note: the hand-out describes a project
that consists of a 1.2 million square foot regional shopping center in
the first phase. Subsequent phases consist of a 1.5 million square
foot office complex and many other traffic generators.) I will be speci-
fic and I'm focusing on one EIR, but you can relate it to just about any , P
other. First of all, for this specific EIR there were a lot of the
standard statements that there would not be an air pollution problem at
ultimate development even locally, since all of the controls of motor M
vehicles would take care of the contaminants. This is a statement which
I'm sure you've heard over and over again at this course, but it's
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I something we read continuously in EIRs. You get to the point of saying
well, why are you reviewing them if all the controls will take care of
| everything. It's very upsetting to me to accept that statement, and
I've come to the conclusion that I won't accept that statement. But, in
* this specific EIR ultimate development will take place in 1995, that's
I some 20 years away, and the EIR did point out that there's an air quality
impact of some excess of the standards in 1977. But the next date chosen
to analyze was 1995! I submit to you that that is not an adequate way of
_ doing it. Each EIR should consider some interim period when a worst case
traffic condition might occur and when there might be a worst combination
fe of emission factors. If you plug it all together you'll probably come
up with more excesses of the air quality standard than in 1977. This is
I really important to keep in mind--I see this all the time. Determine the
impact in 1980, for example, if you are dealing with 1977 to 1995. I
9 can't give you a specific interim date, but you should focus on some
M period that would be a worst case period and you should address yourselves
to it. Also, in this particular EIR there was no discussion of emission
factors, no discussion of speeds, and no references, but this is really
atypical.
I
Another problem in this particular EIR, and I think it's a problem
with many EIRs, is the optimistic, and I would say misleading statement
about the kinds of road improvements that will actually be in place, in
V the time period corresponding to the time frame of the development. This
particular project required a new interchange with an interstate road, in
V order to make the project go. If the interchange is not built, the EIR
j| writer says that traffic would be forced to use narrow streets which
would cause the level of service to drop to E, that is, near breakdown
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conditions. Since cars would be moving at very slow speeds under stop «
and go conditions, there would be more pollution. Now, the impact of ~
that possibility was not discussed. It was just an assumption, a tacit B
assumption that the interchange would be in place--and we're dealing with
an interstate raod. Additionally, the EIR writers pointed out the State I
indicated that it was very unlikely that they would build an interchange _
at that location because it was too close to another interchange. So,
what seems to follow from all this is that there is absolutely no guaran-
tee that that interchange will be built, or, that if it is built, it will
be built in the time frame corresponding to the development. Again, I m
see these statements very often in EIRs, and I think it is very important
to be wary of them. I don't know what should be accepted in the way of a
guarantee, but I would certainly be something more than a statement such
as, "It is anticipated that the interchange will be in place."
There's a section entitled "Measures to Mitigate Increased Traffic"
which is interesting in itself. There's a discussion of transit, of
staggering work hours, discussion of parking costs, and of car pooling. w
All valid things to try out and test. But there was no discussion con- m
cerning what would be needed to implement these mitigation measures and
there was no discussion regarding probable traffic impact, although M
I think there is very little you can do to mitigate the volume of auto
traffic that a shopping center generates. I'd be really amazed if you . V
could reduce auto traffic by 10% or by 20%. For suburban shopping m
centers, it's difficult to reduce auto traffic enough to reduce overall
pollution emissions or the amount of road improvements needed. Another M
mitigation measure that was not discussed, which I think is valid, is
the possibility of scaling down the project, although this is not usually
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talked about. This project consists of a 1,200,000 square foot shopping
center, but maybe a 1,000,000 would do. Maybe 900,000. Something on
that order. And along with those considerations, there should be some
discussion about not permitting development to proceed until the infra-
structure is in place, until you have your roads. I don't know if that's
* reasonable, but it may be in certain cases, and it is something you can
keep in the back of your mind and apply it if appropriate because it is
important.
CEQA requires a discussion of project alternatives, and that involves
m consideration of alternative locations. In this particular case, as I
te recall, there were two alternative locations that were downtown locations;
one downtown location was located in the same city as the shopping center
I site that was studied in detail, while another downtown location was in
another city. Now, you know that no proponent, no city would want to say
that a shopping center in another city would be better, because of the
m revenue generated. I think that's a controlling factor and one that I 'in
glad George mentioned. It's extremely significant because a lot of this
is tied up to where the money's coming from, where it's going to, and
who's getting it. Also, it seems to me that it makes sense to develop
H more than one air pollution impact analysis, particularly if you're
M dealing with a site located outside of a downtown center, and a site
in a downtown center. If you're talking about two sites located across the
V street from each other, it may not make any sense in a regional context,
but it may make sense in a local context. However, where there are
P different urban forms, or other characteristics which differ, I think
that those things should be addressed fully in an air quality impact
* analysis. It's usually not done--it can be expensive to do two impact
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studies but CEQA calls for it, and I think it should be considered.
The air quality analysis for the 1977 phase, as I indicated, did
show excesses of the air quality standard. In this case the excesses
were in the 8 hour carbon monoxide standard, and the excesses occurred
where homes were located. But there was no indication of the number of M
homes for example, and no indication of the number of people affected.
I think this is a prime consideration--how many people are affected?
That wasn't in there. My last point is that the EIR does point out that B
significant increases in air pollution will occur although they will not
necessarily exceed the standard for certain areas. Unfortunately the
location where these contaminent increases will occur is where there is a
nursing home and an elementary school. Now, there has been a lot of
discussion and cavalier attitude about the kinds of things we're doing m,
here, but it seems to me that these are the kinds of sensitive receptors--
the people--most sensitive to air pollution and they are often not con-
sidered. Older people and younger people, people who have respiratory
problems are affected most severely. Now it seems to me that given the
uncertainty of the road improvements that I discussed, questions concern- H.
ing the correct emission factors, and all of the questions about correct
deterioration rates and the like, it seems to me that it is prudent to say
that the impact analysis should assume that there may be a slowdown in the
road improvement program, or that the emission factors won't be applied f
or will be put off...and see what the impact will be on those 50 or so old _
people living near that road. Perhaps they shouldn't have been put there,
but they are there, and I think that that has to be considered. I think ff
it is extremely serious and I urge you all to keep it in mind, and to
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require in any EIR a thorough discussion of where hospitals are located,
where schools are located, where playgrounds are located, and where they
will or are likely to be located. And I think that is a responsibility of
the proponent of the project in combination with local planners to locate
where those existing and future sensitive receptors are. Sensitive
> receptors also include you and I--people living in the residential areas.
It includes human beings, and that is often not considered for some
reason. And I think it should be.
QUESTION: (Waide Egener) I think a project of this sort demonstrates the
difficulty of doing, even with the best of intentions, an adequate
m Environment Import Report at the local level under prevailing circumstances.
The question to an air pollution agency would be: Suppose the proponent
evaluated a number of alternative locations and the impact of building
the facility at those alternate locations at the microscale. That is to
say, in the downtown or in the next community right next door or a little
« way up the road, liow is the proponent to know--how is anyone to know--that
given the condition of the air quality in that area, none of these sites
will be satisfactory. What direction is offered to project proponents by
any agency on what kinds of alternatives beyond the immediate area they
£ ought to take into account.
ANSWER: (Herman Volk) A good question. Unfortunately, it's difficult
* to determine what the impact of a project will be without doing some kind
tl of analysis. And heretofore, before Dick Thuillier's really superb de-
scription of what you can do, it was too mind boggling to entertain. Now,
IE after this course, if everybody goes out and spreads the gospel, it may be
possible to do a kind of quickie analysis for each one of the sites, and
try to come up with some idea of what the impact would be. But before
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generally go along with what Herman said. But I would make a
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this course I wouldn't know exactly what to tell you; I'm glad I took the
course.
QUESTION: (Bill Rugg, Planning Director, San Leandro) I wonder if the V
panel would play a little game with me. I want to ask each of you to give
us three pieces of information--on say, the last project. First, as a |
staff person, if the indirect source regulations were in effect, would «
you approve it, or recoFtoiend approval, or recommend disapproval. Second,
if you recommend approval, what specific conditions of approval would
you recommend?
ANSWER: (Herman Volk) With no authority invested in me, I will answer £
that question. I think what the staff would like me to do is to determine
the number of excesses in the air quality standard that would occur, and
perhaps state that the excesses are significant or are not significant. I
And perhaps what they would do, and I really don't know, is to leave it
up to the Board itself to determine whether or not it is really significant--
the Board being the Board of Directors of the air pollution agency. I ^
don't know if that's really a "cop-out" or not, you'll have to really *
judge for yourself, but if something will exceed the standard, say two
more times, or three more times a year, the question is: is it signifi-
cant or isn't it significant? I don't know how to make a determination M
without some kind of maintenance plan, something else to relate it to,
and not just hang it on the air quality standard. If you can say it -
exceeds the standard two times more a year and also is inconsistant with A
a control strategy or a maintenance strategy, it seems to me that you
have better backing. I
ANSWER: (Ralph Mead) It seems to me as a staff person that I would
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A recommendation--not as me individually, but as part of the technical
staff in general--! would make a finding or a determination to the air
pollution control officer who has the administrative power to make the
decision. That finding would include such things as how many times the
f standard would be exceeded. Now, I would anticipate that if there were
^ indirect source regulations that there would have to be--concurrent with
the adoption of those regulations or subsequently before the review of
projects--the question of significance would have to be addressed in
some either general or specific way. It certainly would be desirable
£ that' there be a publicly known position on that, as to whether a certain
number of excesses in and of themselves require a turndown. My guess
is that it would not--that is the number of excesses alone would not--
fl| but that there would be guidelines which would leave the final decision in
the judgment of the administrator and would include such factors as how
many people would be affected, as well as other factors that have not
been discussed here, might even have something to do with VMT (although
that's a concept that I abhor and hate to work with. But that's another
story , VMT, though it can be a rough guide to magnitude of impact.)
The answer I would give--I think it's up to the administrator or decision-
making person, given the technical information as to the impact, how many
times the standards will be exceeded, where, how many people will be
affected and so forth, and there may be other factors as well. There
was the whole question that was raised: how do you take social and
economic considerations into account? The answer to these questions, of
I course, is something that I don't have complete control over, nor does
anybody else here, and we'll have to wait and see.
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ANSWER: (Vivian Brown) I think in view of the fact that I don't think
decisions should be made solely on the basis of one factor, be it air
quality, water quality or economic growth, that if I were Queen of the
region I'd make the decision that the project should go ahead provided
that since it is in a corridor that will be developed, prior to the time I
that development be undertaken of this specific portion of the corridor
the staging plan be produced for the entire corridor that would indicate V
how growth was going to take place and how local transit and internal A
transit could be provided to alleviate the problems that have been
identified. Again, it would be doing it in a context of a plan for the
entire area which is one that we've already said should be developed.
|
ANSWER: (Waide Egener) I'll make it very brief. Since there's been a
lot of controversy about indirect source control, I'll just turn the m
question around and say perhaps as planners for local jurisdictions, if
you were reviewing a project for a shopping center in your jurisdiction,
and if the Environmental Impact Report that you had prepared technically
indicated that the center would produce considerable revenue for your |
community, would permit you perhaps to lower the tax rate, or at least «
keep it where it was, but nevertheless it was quite plain from the
information that it would have a severe impact on air quality, would V
you recommend to your council the denial of that shopping center?
QUESTION: (Michael Lake, Planner with the City of Sacramento) I would . |
like to think that I'm something less than an ivory tower planner. As a _
result, I'd like to be a pragmatist. To do that, however, I'd like to be "
able to relate air impact to a given set of standards on what was signi-
ficant, what was adverse, etc. I think I speak as a layman, not as an
expert, as many of you people here today are. But I'd like to know if
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what I propose as mechanism for achieving those standards is possible.
Perhaps some of you in the audience would also like to contribute. I'd
m like to see it done before I leave today, otherwise my three days have
m been wasted. I would suggest that one of the means of approaching this
on a more practical level, would be to relate these standards which we
V generate for air pollution, in terms of air, quantity of particulate
matter, whatever }to a set of standards which would be addressed first of
| all to the microlevel of a community or a site, whatever, as well as the
m macro-level, that you use as the mechanism for adoption the legislative
body,'the control agency, whatever, use it as a sounding board to revive
public hearings on it, and thereby, have a given set of practical
evaluation measures. We do it everyday in normal living...we're condi-
| tioned as human beings to equating a set of values against a given norm.
M It seems to me it has tremendous possibilities in terms of making our
* day-to-day functions more practical and efficient, wasting less of our
taxpayers' money, etc. Do you want to make any comments on that?
ANSWER: (Herman Volk) I don't know if I understand the question, but I
| just want to mention something. If you want to relate something to a
standard, you could use the federal standards or the state standards, for
* example--standards which say that if you exceed the CO level more than
JB once a year it's a no-no--don't do it. But you could literally determine
whether you do or you don't exceed the standard with a project, and if you
do exceed the standard you can say you don't want to approve it. The
problem with that is that, in the Bay Area we exceed many of these
standards already, so what do you say..do you say, well therefore we're
not going to develop? Do we all want that? We kind of go around and say,
well let's question the standard again, and this is done. The standards
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have been questioned ever since they were written. No one has stopped £
questioning the standards. *
QUESTION: (Michael Lake) Yes, I can appreciate that fact very much, I
however, the general overtone is one that we should use first of all--
models--they are a practical vehicle for addressing the whole issue |
of air quality impact. We should use standards, however imperfect they _
may be, as a means of getting quantifiable data. Now, it only seems '
practical to me that you take that one step further--that you have a ft
structure or a mechanism for evaluating what comes out of that. Hopefully,
the three days we've spent here we've been trying to learn how to get
to that point and evaluate it against standards. Until we do that--we've _
accomplished nothing.
ANSWER: (Herman VoIk) Well, you will be doing that. Perhaps I'm not
hitting the mark, but you will be evaluating your results against a
standard to determine the number of excesses, and then it's up to the one
who makes the decision as to whether or not they want to live with it.
QUESTION: (Michael Lake) Perhaps I have misunderstood some of your
general thinking. It appeared to me, however, that you did not have a A
given set of criteria on which to evaluate what is significant, or what
is adverse impact, whatever you want to call it. I would like that I
criteria.
ANSWER: (Ralph Mead) I just want to say one thing which may or may not .
answer the question: We have a couple of other considerations here. fe
When the Clean Air Act was passed, I doubt whether anybody thought
specifically--including the people passing the Act--and said, "do we
really mean we want to stop growth, for example, in a given area if
that's what it comes to, in order to, (if that may arguably be proven to B
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0 be necessary) to prevent any excess of the ambient air quality standards
at any point anywhere within that area. I doubt whether that happened.
J| Now, with the indirect source regulations, the EPA is taking that
^ approach, and promulgating the regulations, so we may be faced with having
to address exactly that question. It's not an easy question, and if I had
to make that kind of determination, I think I would be very hesitant to say
that an important project, which might for many reasons be important for
g the community, should be denied because there was a single, or two, minor
_ excesses of a certain standard at some point. I would be very hesitant
to do 'that.
Responses from Michael Lake: I would concur with you, all I'm suggesting
is that in the area of air quality you need to reach a point, and a deci-
sion as to the air quality and its impact. Unless we have definable
levels, then we aren't there. The total, the economics, all the other
variables of course have to be considered.
QUESTION: (Arthur Schwartz) This actually goes back to Bill Rugg's
question, and it's really a statement. Somebody once a long time ago
V said "If you can't stand the heat, get out of the kitchen." The law is
fairly specific and court decisions have been very specific. UIR's are
supposed to be prepared by qualified experts who can make judgments
based on their experience. We can play around with all the numbers we
want, and determine how many days a year we might exceed the standard,
but in the end the judgment that must be made, and is ultimately made by
the decision-making body, the Board of Supervisors, the City Council, is
V one to approve or disapprove. These people are generally not technical
people. They need guidance from the technical people, they need a
statement as to whether this project does or does not have a significant
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impact on the environment. We as consulting engineers, myself with M
Ecological Impact Studies, have taken the position that we must make
those judgments, even if they happen to be subjective. We still have I
to make them and we have to stand up and be prepared to defend them.
We think that every staff member of every jurisdiction and special |
agency must do the same thing, otherwise they are abrogating their _
responsibility both to society and under the law. The statements I've
heard today about the lack of our ability to make judgments, or the jt
lack of our readiness to make judgments OF whether or not something is
significant, and to go back instead of playing around with some numbers,
one-or-two-days-a-year type of thing, is really very depressing, because
this way we will never solve air quality or any other problems.
Response from Person in Audience: I think in trying to set the significance ft
and set the level or reach the levels of criteria that we're looking at
today, I think we have to fall back on the one solid thing we have, which I
is the Act as the gentleman before me started to mention. I'd like to
just very quickly review what the Act tells us. The Clean Air Act says
that we are to consider land use controls and it specifically mentions
those controls. I think that the framers of the Act certainly considered
that in some cases you might have to affect land use. I think it very M
specifically says in its present form that economic and social considera-
tions are not to be taken into account. I repeat, NOT. That is speci- V
fically excluded from the Act. The Act further sets air quality standards fe
and required that the administrator of EPA set them, based on health
effects. Those standards are set to protect the public health. They are
not to be violated; it is as simple as that. I think therein lies the
first standard. If a project or a group of projects violates air quality
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tt standards, then it has to be modified or it cannot be built. Here are
two levels of analysis: one is the immediate and local impact, rind the
£ second is the broader, regional impact. The second level that we have to
^ look for significance in is the State Implementation Plan- -we went through
* four years of developing plans to implement those air quality standards
and they call for reductions in emissions. If some project is not consis-
tant with reducing emissions, then again, I think you have reason to object
| to that project. The third level is the Air Quality Maintenance Plan.
Again, we're required to maintain air standards throughout the future. If
the project is inconsistent with plans to maintain air quality standards,
there is another reason for refusing the project in the form which is
presented. I couldn't agree more with the gentleman before me saying that
those on the regulatory side have to stand up and say that the project as
presented is inconsistent. It needs to be amended or dropped, and leave
it to the planners, the developer who has the interest in changing the
project to find an acceptable means of presenting the project. I have
one suggestion that we're working on in the Washington area, and it may be
of help. Perhaps the planners in the land use, air quality, and
transportation fields in conjunction with those in the private development
9 side could set up some basic conditions: Say, in this metropolitan area
there is a certain kind of air quality. We'll assume certain things about
meteorology, we'll assume certain things about transportation. Then have
standards for preparing Environmental Impact Statements. We will review
certain things on all EIRs, and then have mutually agreed upon criteria
m for reviewing those statements. I think that would simplify and solve a
lot of the problems that we've been addressing here today. A large
portion of this is judgmental, professionally judgmental, and I think we
need to come to an agreement of these judgments. 277
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£ DISCUSSIONS OVER LUNCH
June 26, 1974
GEORGE 1IAGEVIK: ...we can point out which social disruptions these
£ programs are going to cause. What we see happening now is an attempt to
M push back the deadline '75 to '77 and give us more lead time. If we
have to achieve standards by '75,draconian measures are called for. If
we push back the time frame to '85 or '81 or what have you, we dramatically
increase our options. Some of these options involve positive programs
P rather than negative ones; the best example is provision of transit
facilities. I think we're going to see in the oversight hearings on the
Clean Air Act that Muskie's going to hold in 6 or 7 months hence
jl discussions of moving the dates back, We don't see any significant
attempt to change the standards. There might be a possibility that the
standards for sulphur oxides might be made more stringent, rather than
~ weakened. The question of the planner from Sacramento was we need a set
of operational procedures that we, meaning the planners, had operation-
alized air quality management, from the land use planning sector.
Traditionally, planners have been concerned with health and welfare in
their land regulatory programs. We have things like set-back requirements
where you have to build your house so many feet back from the roadway.
We have building codes which are supposedly health and welfare related.
One could argue that the planners traditionally should have been dealing
with these kinds of problems. Unfortunately, the mechanisms that the
planners have had have not been adequate to deal with these problems. As
most of you are aware, one of the major difficulties is the variance
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procedure. You can have the most beautiful plan, but if the elected _
officials will allow projects to go through by gi\ing them variances-- *
out the window goes your plan--your grand design. Similarly, with I
environmental control programs historically you could get a variance.
That's much more difficult to get today because we do have these p
quantitative standards that we're working with. We don't have opera- ^
tional standards for planners at the local level. Other than to say
you need a buffer zone here, let's have a set-back requirements of 50 ft
or 60 feet so the carbon monoxide can diffuse a little bit; and change
the design of the structure a little bit so that the windows open away
from the roadway rather than facing the roadway. We can deal with the
micro-design solutions. The problem seems to be is that the problems
are regional in nature and require actions, as we've heard earlier, by It
many more than just one agency. It's difficult to give a set of specific
procedures to the planner at the local level. Now in terms of saying
yes or no on a project if we accept the Air Quality Act at face value
and the regulations at face value, we indeed should turn down these
projects just like that. This doesn't seem to be happening because the
final decision on these projects rests with elective boards by and large,
and that's as it should be. In the final analysis decision, the technician I
will advise members of the board and they will made decisions as they
see fit. Often you might argue it is counter-productive to the air quality 9
objectives; that seems to be a fact of life. That's my interpretation of ft
why you get this ambivalence on the part of people who are involved in the
evaluation of impact statements, rather than saying no just like that.
Because when they say no it might not be supported higher up.
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DAVE HASKINS (attorney): Responding to what you just finished saying,
I think that the problem is, not that the staff technicians are saying
this is a violation and therefore should not be done- -and then their
^ superiors are countermanding their recommendations --the problem is that
* the technical people are fuzzing it to start with. That is the problem.
fl The political system has made a judgment which may be a hypocritical
judgment, but the hypocrisy is only going to be demonstrated if the people
| who are delegated the responsibility to make the technical decisions, make
them straight and make them strong. The discussion we heard this morning
showed an unwillingness to take that first step. The political system can
make efforts to deal with the unwillingness of the representatives to
follow up on what the technical analysis indicates. But what we're not
seeing such a statement. For example, during the discussion of the airport
expansion, there was a simple statement that certain air quality impacts
» weren't assessed. In my view, making that simple statement is not
adequate. There should have been a critique of the fact that those
impacts were not assessed. There should have been a statement by the
board charged with the responsibility that- -Dammit you had a job to do
and you didn't do it and it's wrong that you didn't do it. Here's why
9 it's wrong, and here's what should have been done. That's what you need.
You need the first order activity by the technicians that have been
delegated the responsibility so that you can see whether the system
I
works or not.
GEORGE HAGEVIK: My response would be a question to you then. That if
the system is not operating this way, what recourse does the average
P citizen then have to the fact that the Act is not being followed? For
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example, an organization such as yours responds, in the case of signi-
ficant deterioration, say, by a lawsuit. Is that the only alternative
I
to improve the quality of decisions, or are there other ones?
HASKINS: In an ideal system there are a myriad of alternatives. The way m
tax structures work, our organization cannot lobby for legislative change
because of our tax deductible status. We can bring lawsuits, and we V
can put the politicians to the test of their often hypocritical gifts to
the public. The public starts making a lot of noise about air pollution, |
and so the politicians get up and pass the Clean Air Act, which says that m
everything is going to be taken care of, I would rather see a realistic
piece of legislation which says they're going to have to be criteria for
making balanced decisions, and they should be criteria that reflect the
best interests of the public and have the act carried out that way. But |
if an act is going to be passed which says and gives the public at large «
the impression that the air pollution is going to be solved, I'm going to *
make it my organization's business to see that the words of that law are B
enforced. And if people don't want to obey the law, then the alternative
is not to violate the law, but to change it so that it's more responsive |
to what people really do want. So, yes we would bring a lawsuit. If
the technical staff says that the analysis indicates that there's going
to be a violation; the law says if there's a violation that the project
should not be built. Then if the political board above it goes ahead and
recommends building it without making any modifications, then I would urge
citizen groups that are upset by that decision to sue, and to enforce the
provisions of the law. I might say that there is a false dilemma being
presented, and it is that say the image of a needed hospital, or a needed
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social service that can't be built just because there are one or two
days worth of violations. Well that's an avoidable dilemma. The
dilemma here is not whether needed social services are going to be able
to be provided to the areas that need them, the option is that they have
to depend entirely on the automobile. We're talking now about the in-
direct source related measures. They don't have to depend entirely on
the automobile. It may require somewhat greater lead time in constructing
them, and it may require--! think that citizen groups and courts might be
likely to uphold conditional permits which would permit the start of
construction provided that there were enforceable conditions- -conditions
that would be enforceable in a court of law, that there would be transit
improvements to serve those areas. This would mean that the transit
improvements would have to be supported by votes of the legislative body,
and things like that, before the construction could begin. What you would
do then is create a political force working in the legislature to get
M those transit improvements, because they know they can't start putting
those shovels in the ground until the transit legislation is on the books.
That's the kind of thing- -you have to start building coalitions, and you
can do it by making conditions and not by saying flat out- -No you cannot
0 build this hospital because it would attract too many people and their
cars going to see the doctors. There are modifications, there are
* alternative control strategies. If you have a hydrocarbon problem, you
jl
can look toward more stringent revisions of the hydrocarbon standards.
For the emission controls on stationary sources you can look toward
improvement of emission control reduction techniques. There are a variety
of options and I think that what we are faced with is the question that
* was put by one of the panel this morning--If you were a planner, would
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you recommend that a facility that was going to generate a lot of revenue,
be turned down. Well, if you don't have some rules when you're going to
turn down some of these--if you don't have rules when you're faced with
a project that has an employment opportunity or a revenue opportunity,
then we might as well go back to the days of slavery and the earliest
days of industrial revolution. Because the very same arguments were
made then--about the textile mills, about the cotton plantations, about m
the coal mines--the very same arguments were made, and if you don't have
rulesare you going to accept slavery or are you going to refuse it. And
if it costs you something are you going to refuse it? If you don't have
the standards, you're just wallowing through a marsh that's very frustra-
ting to citizens and very frustrating to me to hear that kind of m
discussion. m
JIM ASHTON (APCD, Las Vegas, Nevada): I just had the opportunity of
taking a T.V. course sponsored by the consortium of colleges in that area,
and the University of Nevada. In that the question came up this morning
as to what defines significant impact. Yet you have right here in the
law or in the guidelines that follow it a very well-defined definition,
which in essence says that significant impact is anything which interferes
with the achievement or maintenance of air quality standards. Nobody on
the panel or anybody else brought it up. I would have thought that
would have been an adequate answer to the question that came up several
times. Also, CEQA in their guidelines gives a significant basis of
evaluation for EIRs and EISs. One further source where one can find
some general guidelines, would be the Geomet reports that came out, the
ones that were done under contract to EPA. They provide some basic
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M information and some fairly good data. However, one must recognize that
this data has to be adjusted to the given set of conditions or locations
under consideration at a given time. The question came up of somebody
putting their job on the line. I think those of us that are in the
| enforcement activity are getting paid in one sense or the other by the
taxpayer's dollar, whether by gifts to the department they're working
* for or through direct taxation. And I would ask- -What in hell are you
fl getting paid for?- -if it's not to protect the environment through the
group that you're working for? It does not seem out of line at all to
make ~a recommendation if something is going to violate the standard to
_ the deciding board, that it will be in violation. That is a part of what
we're getting paid for.
I DICK THUILLIER: I'd like to address myself to that particular question.
M And after sitting up here and watching everybody munch their chicken, it
was reassuring to find out that we definitely are all human, and I think
I the idea here is that in a political system such as we have, we have
people having to deal with other people. And we have a very wide diver-
| gence of opinion on what is good and what is not good. Basically, as
^ far as getting the provisions of these various pieces of legislation put
into effect, we have a stratification I think in terms of decision-makers
B and their staff. I doubt if there are very many people in this room right
now who are in a position to actually turn down a project. I think most
P of us are in a position of providing information to decision makers who
will in turn, turn down the project or not. Now, I think it's the re-
* sponsibility of the staff people to present the information in the most
fl objective manner possible. And I agree with the gentleman who just spoke,
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and also with Herman Volk before who did in fact indicate that we M
could use the ambient air quality standards are our criterian of
significance. As a matter of fact, the standards are the only defined
criteria for significance that we have. In the case of our own staff,
when we submit a recommendation to our air pollution control officer, |
that recommendation very simply takes a form of stating: This project ^
will cause the air quality standards to be exceeded. Now we could also *
add: "Therefore, we must recommend that the project be turned down." I I
don't know that we have to make that specific recommendation because
that's fairly clear in the law. However, the particular regulations
of the individual control districts frequently will contain their own _
woiding that will enable them to handle some of the trivial situations
in the law. The law is meant to be interpreted in some way and I think
that's why we have courts. To the degree that the ability exists to
interpret laws there are always going to be interpretations made. We I
run into the problem in the Pollution Control District when we first
frame a regulation such as this. Our original regulation stated that
in an area where the air quality standards are exceeded, a permit for
the project must be denied. But very soon after that regulation was
adopted, questions began to come up. I'm going to open up a bottle of I
ammonia in my area--is that going to be cause for denial of a permit,
because standards of the odor regulations for ammonia might be exceeded 0
two feet from the source, or something like that. So, after you come
out with the original draft of a regulation, then you start to get
feedback on some of the types of projects that could be construed to fall
under the wording of the regulation but are obviously not the type of
thing you want to stop from being built. Therefore, what has gotten into
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our regulation now is the term significant--in other words suppose the
air quality standard has already been exceeded, but you're going to
build a project--say it's a hot-dog stand in that area--do you want
to require a permit for a hot-dog stand, and do you want to refuse per-
mission to put that project into effect because it's obviously going to
contribute additional pollutants in an area where an air quality
standard has already been exceeded. I think that the decision makers
and their legal staffs have the prerogative wherein they're able to put
their interpretations on some of these regulations, some of the legisla-
tion,'and they do in fact do that. I think all that we can do as staff
people is indicate that the criteria by which we work, which in our case
is the air quality standards, are exceeded, and then let the decision-
maker put the interpretation on the law. I don't really feel myself
that staff people should try to interpret the law. I think they should
take the law that is given to them, and they should analyze things with
respect to that. In our case, it's the air quality standards, and we
can objectively indicate whether the criteria in those regulations arc
met or whether they are not met. Since we do not have the prerogative
to make the final decision I'm not sure that we have the responsibility
I to try to interpret the law.
BILL RUGG: Dick, let me pursue a little bit more what I started to a
few minutes ago. If you take what you just said literally, I think that
this is one of the things that those of us in the audience are objecting
to. i/hat I would hope that I would see in the staff is that you might
report to your Board that--yes, as submitted, such-and-such does exceed
such-and-such standard, however, with certain changes in the submission,
I
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under certain conditions that you could list, it could be made to fit V
into the standards. In other words I'm talking about a very distinctly
positive view--you and I talked about this a little bit yesterday--where I
you'd work with the developer or with the applicant to find other ways of
doing what wants to be done, but ways that fit into the standards. We
looked into that hypothetical airport this morning, and there may be ways
that that hypothetical airport may be less injurious than as proposed.
I would hope that the staff at the pollution control districts would
include a positive input, and some rather distinctly specific work with _
the proponents. Rather than simply say--yes it does, or no it doesn't
meet standards. If you could comment a little bit more on what kind of
positive input the pollution control district staffs are willing and able
to and are equipped to make, I think this might clear up some of the I
problems that we've had out here in the audience.
DICK THUILLIER: O.K. Thank you. I think I am addressing myself pri-
marily to the idea of commenting on the significance of the particular g
project. .But certainly the remark that was just made is very valid and .
very apt in the case of the Bay Area Air Pollution Control District. *
I'll give you a scenario of what normally goes on when an application fl
for a permit is received in the district. We receive the permit applica-
tion from the applicant, the impact of the project is evaluated, and
let's say we come up with a clear-cut situation that the standards or the
District regulations or whatever criteria we're measuring against are
exceeded so that a permit must be denied. This has happened in a great
number of cases. I might just indicate the type project that will come
in: one type of project was a refinery expansion in Richmond. Some
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B of you may be familiar with it. In this case, a project might come in
and we would evaluate it and decide that, we're going to have to deny a
permit, because the wording of the regulation is very specific in regard
to one or more areas of the analysis. The next thing that happens in the
scenario is that we notify the applicant that it looks as if we're going
to have to deny the permit on the basis of certain criteria and develop-
ments in the analysis, and the applicant normally comes into the District
and we sit down with them and discuss the problems that are involved. Then
in the case of some of the projects modifications can be made. They'll
» say okay well we'd like to expand this refinery and we think it's very
important therefore we're willing to curtail some other aspect of our
operations so that the net effect will not run afoul of your requirements.
So, go back and re-submit your application with the new data that would
result from this modification, and this is done, and we re-evaluate the
project. In most cases, in situations where we originally would have to
deny a permit, we are able to grant the permit on the basis of the
modifications. Now, the other aspect of the question you asked involves
the business of getting together with the applicant prior to the submittal
of the application so that we can foresee the problems and iron them out
8 ahead of time. And with respect to this aspect I can only say that we
m are continually having representatives of consulting firms and planning
agencies coming in to the district. We're sitting down with these
people and talking about upcoming projects and trying to indicate what
types of analyses will be involved, what we'll be looking for and where
8 some of the problem areas might arise. So, I would certainly say that
M what you suggested is certainly the way it should be done, and I think
to a great extent the way we do this in our present operations.
I
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BILL RUGG: I think that the next step then Dick, one that presumably you
will be getting into either this fall or next winter, would be doing this "
kind of staff work with indirect source regulations in which you may be
making recommendations on land use. This is an area that is quite differ-
ent from modifications on a refinery. You'd be making recommendations I
presumably on, Yes, Mr. Developer, what you want to do is fine, but it
ought to be someplace else. Or, you've got to extend the BART System,
or build a shuttle system or something of this sort. It's a whole new
area for air pollution control staff personnel to be working in, and
this is the area, of course, that has the land use planners concerned. I
Certainly, getting in before the application is submitted and working
with your staff, is going to be very important. I wonder if you would
comment on the ability and willingness and availability of your staff to
make recommendations and provide real assistance in land use planning
decisions before applications for indirect sources are submitted.
DICK THUILLIER: O.K. Well, first of all, I think that any staff that
is going to do this type of thing is going to have to have expertise in
a number of areas that usually are not found in air pollution control
districts, and this includes both the areas of land-use planning and of
transportation planning. In our case, we do have this expertise, but
it's embodied in one or two people, and our staff is obviously involved
in things other than just sitting down with applicants. So, I think all
I can say there is that we have the expertise if we're provided with
the type of information that we need to make judgments in that regard,
and we can in fact do it. However, frequently, far in advance of a
project's coming in for a permit, there is just not the specific type of
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information available on which to base an analysis, and perhaps to answer
your question, I might say that it's usually not very easy to anticipate
the problems involved with the permit very much prior to the development
_ of hard information, that accompanies a permit application itself.
LEE SINCLAIR (San Bernardino APCD): As I understand it, in the South
B Coast Basin of which we're a part (a part of our county is part of the
m basin), the indirect source regulation will in essence say that the APCD
shall review all projects that may have an effect on air quality, and
shall deny authority to carry out that project unless the air quality
standards are maintained, or words to that effect. My point is that we
| have a system of reviewing applications and issuing authority to construct
and later permits to operate for stationary sources, and under the proposed
* regulations for indirect sources, I see nothing but to take a very similar
approach on them. 1'his would follow the procedure that Dick outlined a
little bit ago. I think it's going to boil down to the place that the
jj APCD--or perhaps myself or another engineer as the representative, will
^ review the project and will make a determination that it either does or
does not prevent the maintainance and attainment of air quality standards.
If it prevents that, we will have to deny the permit. That can be appealed
to the Board of Supervisors sitting as the Air Pollution Control Board,
or to others, perhaps even taken to court, but we will have no choice than
_ to say, No--if it does not meet those criteria.
DICK THUILLIER: I think I would agree with you there. I think the ideal
| situation for a single purpose agency such as an air pollution control
IB district is to address itself simply to the air quality standards that
are available and make the decision as to whether or not the air quality
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standards are met. Then pass their decision on to the decision making
authority, or in the case of the air pollution control district, if there
are clear criteria available, it should simply grant or deny based on the B
fact that the criteria are or are not met. I think one of the purposes
of this course was the fact that the analysis procedures for determining |
whether or not the criteria are or are not in fact met, was an item of «
some confusion, particularly among a lot of the non-technical staff people
who are involved in the business of evaluating air quality impact. We I
were hoping to give a suggestion and not give a mandate on how this
analysis should be done. A lot of people have come to us and said, Well
O.K. you say we should do a quantitative analysishow do we do it? This
course is our response to that. Here are some suggestions as to what you
might do, and perhaps the weight of our remarks would consist in the fact
that we are an agency that makes requirements, an agency that must be
satisfied as far as air quality is concerned and we're saying--this is
how an agency that must be satisfied would like to see its input data
developed. B
JAY BATES (Federal Highway Administration): It looks like the one thing |
we've been addressing is amendments to the Clean Air Act--I'd like to
make one comment to the effect that you do have other federal laws in
which established planning procedures, established national goals, and
things of this regard also come into play within indirect source reviews
and some of these other things. For instance, there's some basic |
disagreement between the Federal Highway Administration and EPA regarding ^
indirect source regulations which is going to have to be worked out in
the future. Some of these things will be worked out, but it's not clear
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that you can make reviews and permits on certain other facilities which
involve other federal laws other than the Clean Air Act.
| GEORGE HAGEVTK: I'd like to respond to the point. One example of that
problem would be in the Bay Area, where the Metropolitan Transportation
Commission (the Regional Transportation Planning Agency) essentially for
I all practical purposes does give permits on all highway segments proposed.
Now, with the promulgation of indirect source regulations we could have
I two essentially separate agencies giving permits for the same highway.
_ The trouble is- -if one agency says yes and the other agency says no--
what conflict resolution procedures do we have? At the present time the
B way it's structured, indirect source regulations would prevail over the
two, based on my reading of the respective legislative mandates. But
that's not clear, because it hasn't really occurred yet. These problems
do exist.
MARVIN HYMAN (Frederickson Engineering Consultants) : This is getting
| back to the critique of the course. In circulating around yesterday, I
heard some of the people from planning agencies complaining that the
material was too technical and above their head, and we who are in the
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consulting business feel that yesterday's presentation was very to the
point and helped simplify a lot of the correlations that could be used.
I'm wondering, is there some better means than presently exists of
getting consultants and planning agencies together- -the only thing our
firm can do right now is to write to every city and county planning
agency in the state and say we exist and here are our capabilities, and
if you want us we are available. Is there some other means that we can
make our presence and capabilities known, and that the planning agencies
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whether they're city or county or whatever can make their needs known.
Maybe there's a list of people who are taking this course that could be
made available, and I would like to know if people who are planners here |
would be offended if consultants started sending them solicitations? ^
DICK THUILLIER: We certainly intend to provide a list of participants
in the course along with the proceedings so that everybody can know by 8
name and address who everybody else is in the course. I really don't
know how to answer your question as to how to get these people together.
I think the only real way is for the consultants to knock on the door of I
the planning agencies, and if the planning agencies are seriously inter-
ested in hiring consultants they should be going out and looking up |
consultants and finding out what they can do. When they do get together, m
I would strongly recommend that both the consultants and the agencies
that are hiring them in the air quality area would also make contact with
the local regulatory authority, in this case the air pollution control
district, so that all three of these people if you will can be sure that |
they're all talking on the same wave-length, so to speak. It's not «
going to do a planning agency any good to hire a consultant if the
planning agency doesn't know what the consultant should be doing for I
them to satisfy the pollution control agency. And I think this triangle
is very intimately connected here, and I would like to see each planning
agency that does hire a consultant have a consultant available that it _
knows can meet the requirements of the local regulatory agency and can
do a good job. The agency should maintain a working relationship with
these consultants on a long term basis--and not just go out and quickly
hire a consultant at the last minute to do something. If anyone else
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has any suggestions on that topic we'd sure like to hear them.
« ANN RENNER (California Air Resources Board): I just have a few comments
* by way of a critique. I think that this is a very good first step and I
think that we are going to be seeing more of these kinds of workshops as
we pull this thing together. One of the things that I hope is as
planners we will see air quality as an opportunity rather than as a
_ requirement. There were bills signed by the Governor, just in the last
* month, I believe, that sets a new requirement for the Environmental
Impact Reports and requires some description of energy mitigation
measures, so that these things will be tied together to support the
goals of air quality rather than just balancing against social and
economic considerations.
QUESTION: I still have a technical question, that means away from the
| political questions. I'd still like to know how you predict the effect
am of air quality for future years. r»/hen you evaluate air quality,
you know the future traffic, you know the future emissions, but you still
need the future background data for your air quality study. How do you
do this? Do you have a formula or a curve to do this?
DICK THUILLIER: Well, the same formulas that are used to calculate back-
ground in the base year can be used in future years if you have an
estimate of future emissions. This means obtaining an inventory of
emissions in the future year, and then applying the same modeling tech-
m niques. I think that the main problem in the projection arena is the
emissions, because the modeling techniques remain the same, and the
atmospheric processes never change.
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(Inaudible question)
DICK THUILLIER: No. The background air quality in 1974 is the result of
the 1974 emissions distribution throughout the region, and the action of
the atmosphere in transporting and dispersing emissions. Now if we go j|
to 1990 we have the same atmospheric processes at work, but the sources _
are located in different areas perhaps and the amounts of emissions from
each source is different. So you simply re- apply the same techniques I
you used in '74, the same modeling techniques, but you'd use different
emissions, a different "Q" to the formula, and that would give you I
different concentrations in 1990, but the formula would stay the same. _
(Inaudible question)
I
DICK THUILLIER: Yes... I think what you're saying is you can get the
projected emissions for your project in 1990 but how do you get the
projected emissions from the other sources in the region. The answer
is that there are two ways you can do it. One, you can get it from the
air pollution control agency or any other agency that's involved in
modeling in future years. In the case of the Bay Area Air Pollution
Control District we expect in a very short time to have a projected I
source inventory at least through 1980 for every square kilometer in
the nine county bay area. You would simply come to us and say you wanted
this for 1990 and we'd give you a computer tape or something with in on.
Another alternative would be to go to the Metropolitan Transportation
Commission or the Association of Bay Area Governments, the people who
are responsible for projecting the parameters that go into determining
the emissions inventory (such as traffic assignments, population |
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distributions), and then get somebody who knows how to construct an
emissions inventory from these input parameters to construct for you
the future emissions. There are very few private individuals or
even consultants who would be able to do this type of job on their own
without consulting the appropriate agency involved.
0 (Inaudible question)
I DICK THUILLIER: I'd like to respond to that point by saying that many
impact statements that I've seen in urbanizing parts of metropolitan
areas^-by urbanizing I mean out in the suburbs--just assume a zero
background because they have no monitoring equipment. The monitoring
equipment is around where the hot-spots are, not out in the suburbs
which are undergoing rapid development. The real problem is that most
planning agencies--for better or for worse--have very imperfect mechanisms
for projecting future levels of industrial emissions. One of the Catch
22 aspects of it is that we're projecting growth, but we're having air
quality affecting the spatial distribution of growth. For example, in the
South Bay Area now, for all practical purposes, we're having air pollution
constraints operative on our planning process, because the population
I forecasts for funding sewage treatment plants are lower in critical air
M basins. So--you're getting less amount of sewage treatment capacity and
slower growth--this is all interacting. So, to get the background for any
specific point in a region 15 or 20 years hence is very chancy. You have
to guess.
(Inaudible question)
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DICK THUILLIER: Let me just make one more point on that. If you can't fl
do this, and in most cases people just don't go through these tremendous
background analyses every time they're going to do a project, and I
especially for the future years, as an approach that's better than just _
assuming zero background or assuming that it's the same as it is in the "
base year, you can apply a growth factor based on what projected growth
for the region is, say in terms of vehicle miles traveled--VMT will
increase by 131 by 1990, but the emission factor will decrease by 50% I
therefore I have a net decrease of 20%. Now that is a fairly crude way
to do it, but it does give you a feeling for whether the background is B
going to go up or down and approximately how much, and that would be
better than doing nothing at all.
(Inaudible question)
DICK THUILLIER: In response to this question of background levels, I I
think there's a source of technical help that's been alluded to a number
of times, but I would like to emphasize it. As we go from the short term
control plans to long term air quality maintenance, one of the things
that could really provide a basis for evaluating EIRs and making
planning decisions would be an area-wide monitoring program where instead |
of monitoring only trouble spots or or monitoring only pollutants that «
are easy to monitor and map, which is being done now, some type of
systematic area-wide monitoring that would provide an historical data
base of the changing pollutant concentrations and would provide a basis
for evaluating the EIRs. |
(Inaudible question)
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DICK THUILLIER: I would agree with you that that would be a very desirable
thing to have, but I would just indicate that unfortunately it seems to
be a very difficult thing to achieve. We have just now, or are just now
are getting to the point where we are going to have our first clean air
station in the Bay Area and this means a station that's not in the
central business district of a city. And I think there are two reasons
why it's basically difficult to field these monitoring programs. One
is that the cost tends to be fairly high, and it's not always possible
to get the budgeting or to get the grants that you need to put the
| stations out into the field. The other is that politically or perhaps
because of non-contact with the scientific aspects of this air pollution
business, its hard to convince people that it's really cost-effective or
necessary at all to put an air-monitoring station where there aren't any
people around. The idea is that we want to see what's happening where
| most of the people are--and why do you want to put a station up on the
hill up there? So I think what you suggest is very desirable but I don't
think it's very easy to do. But it's something that we ought to encourage
I
whenever we have the opportunity to do so.
COMMENT: I'd like to second what you just said about putting out
background monitoring stations, because the first background monitoring
station that we put out had some of the highest peaks in our area. We
havenit figured that one out yet, but we're working on it.
DICK THUILLIER: We run into the same situation. Usually you find when
P you do put a new station out in an area where it was not thought it
_ would provide any information, you find peaksin the case of photo-
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chemical oxidants, that happens quite often, because photo-chemical
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oxidant impact is never in the source area--it's always down-wind maybe
10 or 15 miles. So, you can have the highest oxidant impact out in rural
areas where there aren't any people at all. I
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TECHNICAL REPORT DATA
(Please read Instructions on tha reverse before completing)
1. REPORT NO.
EPA-450/3-76-009
4. TITLE AND SUBTITLE
Air Quality Impact Analysis for Application in Land
Use and Transportation Planning, Proceedings of the
Conference
3. RECIPIENT'S ACCESSION-NO.
5 REPORT DATE
September 1975
6. PERFORMING ORGANIZATION CODE
7. AUTHOR(S)
8. PERFORMING ORGANIZATION REPORT NO.
9. PERFORMING ORGANIZATION NAME AND ADDRESS
10. PROGRAM ELEMENT NO.
Continuing Education in City, Regional, and Environmen-
tal Planning, University of California at Berkeley
11. CONTRACT/GRANT NO.
T-900345
12. SPONSORING AGENCY NAME AND ADDRESS
13. TYPE OF REPORT AND PERIOD COVERED
Environmental Protection Agency
Office of Air and Waste Management
Office of Air Quality Planning and Strategies
Control Programs Development Division
14. SPONSORING AGENCY CODE
15. SUPPLEMENTARY NOTES
Addresses and Discussions of the Proceedings of Conference, June 24-26, 1974.
Conference coordinators were R. H. Thuillier and George Hagevic. Proceedings Editor,
E. T. Hussey. Topics of the addresses were: Air Quality and Land Use, D. Morrell;
Air Quality Management and Land Use Regulation, D. R. Mandelker; Institutional Issues
in Air Quality Management, G. Hagevic; Air Quality Considerations and Local Land Use
Planning, R. Mead; Emissions Allocations-A Needed Framework for Relating Air Quality
Content of EIR's to Decision Making, D. Lieberman; Interaction of the Planning and
Regulatory Communities, Panel Discussion; General Aspects of Air Pollution, D. Levaggi1
Role of Meteorology in Air Quality, R. Thuillier; State of the Art in Air Quality
Modeling, W. Johnson and R. Thuillier; Air Pollutant Emissions and Emission Factors,
H. Harawitz; Meteorological Modeling Input, R. Thuillier; Simplified Techniques for
Air Quality Impact Quantification, R. Thuillier; Elements of an Adequate Impact
Presentation, R. Mead.
17.
KEY WORDS AND DOCUMENT ANALYSIS
DESCRIPTORS
b.IDENTIFIERS/OPEN ENDED TERMS C. COSATI Field/Group
13. DISTRIBUTION STATEMENT
Release unlimited
19. SECURITY CLASS (This Report)
UNCLASSIFIED
21. NO. Or PAGES
20. SECURITY CLASS (This page)
UNCLASSIFIED
22. PRICE
EPA Forrn.2220-1 (9-73)
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