REPORT FOR CONSULTATION ON THE
METROPOLITAN DENVER
AIR QUALITY CONTROL REGION
. U.S. DEPARTMENT OF HEALTH, EDUCATION, AND WELFARE
Public Health Service
Consumer Protection and Environmental Health Service
National Air Pollution Control Administration
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REPORT FOR CONSULTATION ON THE
METROPOLITAN DENVER
AIR QUALITY CONTROL REGION
U.S. DEPARTMENT OF HEALTH, EDUCATION, AND WELFARE
Public Health Service
Consumer Protection and Environmental Health Service
National Air Pollution Control Administration
October 1968
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CONTENTS
PREFACE. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3
INTRODUCTION. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4
PROPOSED REGION.......................................... .10
PROPO SAL. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .10
DISCUSSION OF PROPOSAL.............................. .13
EVALUATION OF URBAN FACTORS...............................20
EVALUATION OF ENGINEERING FACTORS.........................36
APPENDICES. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .50
A.
EMISSION INVENTORY............................... 51
B.
DIFFUSION MODEL DESCRIPTION AND RESULTS..........66
1"-
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3
PREFACE
The Secretary, Department of Health, Education, and Welfare, is
directed by the Air Quality Act of 1967 to designate "air quality
control regions" to provide a basis for the establishment of air
quality standards and the implementation of air quality control
programs.
In addition to listing the major factors to be considered
in the development of region boundaries, the Act stipulates that the
designation of a region shall be preceded by consultation with appro-
priate State and local authorities.
The National Air pollution Control Administration, DREW, has
conducted a study of the Metropolitan Denver Area, the results of
which are presented in this report.
The Region* boundaries proposed
in this report reflect consideration of all available and pertinent
data; however, the boundaries remain subject to revisions suggested
during consultation with State and local authorities.
Formal designa-
tion of a Region will follow the consultation'meeting.
This report is
intended to serve as background material for the consultation.
The Administration appreciates assistance received either directly
during the course of this study or indirectly during previous activities
in the Denver Metropolitan Area from the official air pollution agencies,
The Denver Regional Council of Governments, the Colorado State Planning
Office and Larimer County Planning Commission.
*For the purposes of this report, the word region, when capitalized,
will refer to the Metropolitan Denver Air Quality Control Region. When
not capitalized, unless otherwise hoted, it will refer to air quality
control regions in general.
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4
INTRODUCTION
"For the purpose of es tablishing ambient air
quality standards pursuant to section 108, and for
administrative and other purposes, the Secretary,
after consultation with appropriate State and local
authories shall, to the extent feasible, within
18 months after the date of enactment of the Air
Quality Act of 1967 designate air quality control
regions based on jurisdictional boundaries, urban-
industrial concentrations, and other factors
including atmospheric areas necessary to provide
adequate implementation of air quality standards.
The Secretary may from time to time thereafter, as
he determines necessary to protect the public health
and welfare and after consultation with appropriate
State and local authorities, revise the designation
of such regions and designate additional air quality
control regions. The Secretary shall immediately
notify the Governor or Governors of the affected
State or States of such designation."
Section 107 (a) (2), Air Quality Act of 1967
THE AIR QUALITY ACT
Air pollution in most of the Nation's urban areas is a regional
problem.
Consistent with the problem, the solution demands coordinated
regional planning and regional effort.
Yet, with few exceptions, such
coordinated efforts are notable by their absence in the Nation's urban
complexes.
Beginning with the Section quoted above, in which the Secretary
is required to designate air quality control regions, the Air Quality
Act presents an approach to air pollution control involving closely
coordinated efforts by Federal, State, and local governments, as shown
in Figure 1.
After the Secretary has (1) designated regions, (2) published
air quality criteria, and (3) published corresponding documents on
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States establish plans for implementation,
HEW designates considering factors such as: .
. Existing pollutant levels in the region
air quality - .Number, location, and types of sources
. Meteorology
control regions. . Control technology
. Air pollution growth trends
Implementation plans would set forth
~ abatement procedures, outlining factors
such as:
States hold . Emission standards for the categories of
~ sources in the region.
HEW develops and -
publishes air heari ngs and . How enforcement will be employed to
HEW insure uniform and coordinated control
quality criteria set air quality reviews action involving State, local, and regional
~ ~ authorities.
based on scientific standards in the r State
evidence of air standards. . Abatement schedules for the sources to
air quality ~ insure that air quality standards wi!1 be
pollution effects. achieved within a reasonable time.
control regions. I
~
'""I
HEW reviews
HEW prepares State implementation pia ns.
and pUblishes
information on
States' act to control air
available control pollution in accordance with
techniques. air quality standards and plans
for impleme 1 ation.
Figure 1. Flow diagram for State action to control air pollution on a regional )j sis.
\JI
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6
control technology and associated costs, the Governor(s) of the
State(s) must file with the Secretary within 90 days a letter of
intent, indicating that the State(s) will adopt within 180 days
ambient air quality standards for the pollutants covered by the
published criteria and control technology documents and adopt within
an additional 180 days plans for the implementation, maintenance,
and enforcement of those standards in the designated air quality control
regions.
The new Federal legislation provides for a regional attack on
air pollution and, at the same time, allows latitude in the form
which regional efforts may take.
While the Secretary reserves
approval authority, the State(s) involved in a designated region
assumes the responsibility for developing standards and an imp1emen-
tation plan which includes administrative procedures for abatement and
control.
Informal cooperative arrangements with proper safeguards may
be adequate in some regions, whereas in others, more formal arrangements,
such as interstate compacts, may be selected.
The objective in each
instance will be to provide effective mechanisms for control on a
regional basis.
PROCEDURE FOR DESIGNATION OF REGIONS
Figure 2 illustrates the procedures used by the National Air
Pollution Control Administration for designating air quality control
regions.
A preliminary delineation of the region is developed by bringing
together two essentially separate studies --the "Evaluation of
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ENGINEERING EVALUATION
Input Computer Output
I . Emissions ... Pollutant ... Iso-Intensity
I . Meteorology Diffusion Graphs 4
. Physical Dim. Model
I
Existing Air -
Quality
Sampling
Data
Prelim inary Consultation Formal
Delineation ... with State .... Designation
of and Local by
Regions Officials Secretary-HEW
URBAN FACTORS 4 ~
. Jurisdictional Boundaries
8 Urban-Industrial Concentrations
-Cooperative Regional Arrangements
. Pattern and Rate of Growth
. Existing State and Local Air
Pollution Control Legislation & Programs
Figure 2. Flow diagram for the designation of air quality control regions.
-...J
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8
Engineering Factors," and the "Evaluation of Urban Factors."
The study of "Engineering Factors" indicates the location of
pollution sources and the geographic extent of serious pollutant
concentrations in the ambient air.
Pollution sources are located
by an inventory of emissions from automobiles, industrial activities,
space heating, waste disposal, and other pollution generators.
Pollution concentrations in the ambient air are estimated from air
quality sampling data and from a theoretical diffusion model.
When
it exists, air quality sampling data is more reliable than the
theoretical diffusion model results since the data is directly recorded
by pollution measuring instruments.
Unfortunately, in many cases
air quality sampling data is available for only one or two pollutants
measured at an insufficient number of locations.
The the ore t ica I
model is used to supplement inadequate air quality sampling data.
The box labeled "Input" in Figure 2 describes the information
required to apply the diffusion model.
This information consists of data
on the type, quantity, and location of pollution emissions, the average
depth of air available for mixing and dilution, the frequency of various
wind velocities (direction and speed), and the physical dimensions of
the urban area under study.
Calculations are made with this information
in the next step, labeled "Computer."
The result, or "Output," of the
diffusion model estimates the
geographic pattern of air pollution
caused by pollution sources within the study area, and serves as a
guide to the appropriate size of the air quality control region.
As
a whole, the engineering study indicates how large the air quality
control region must be in order to encompass most pollution sources
and most people and property affected by those sources.
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9
The study of "Urban Factors" encompasses all non-engineering
considerations.
It reviews existing governmental jurisdica tions,
current air pollution control programs, present concentrations of pop-
ulation and industry, and expected patterns of urban growth.
Other
non-engineering factors are discussed when they are relevant.
As a
whole, the study of urban factors indicates how large an air quality
control region must be in order to encompass expected growth of
pollution sources in the future.
It also considers which group of
governmental jurisdictions will most effectively administer a strong
regional air quality control program.
The conclusions of the engineering study are combined with the
results of the urban factors study to form the basis of an initial
proposal for an air quality control region.
As shown in figure 2,
the proposal is then submitted for consultation with State and local
officials.
After reviewing the suggestions raised during the consulta-
tion, the Secretary formally designates the region with a notice in the
Fed~ Register and notifies the governors of the States affected by the
designation.
The body of this report contains a proposal for the boundaries of
the Metropolitan Denver Air Quality Control Region and supporting studies
on engineering and urban factors.
The report itself is intended to serve
as the background document for the formal consultation with appropriate
State and local authorities.
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10
THE PROPOSED REGION
PROPOSAL
Subject to the scheduled consultation, the Secretary, Department
of Health, Education and Welfare, proposes to designate an air quality
control region for the metropolitan Denver area, consisting of the
following jurisdictions:
All lands lying within the counties of Boulder and
Jefferson, and in addition thereto, the following
described area lying adjacent thereto, commencing
at the Northwest corner of Section 6, Township 1
South, Range 68 West; thence East along the section
lines approximately 18 miles to the Northeast
corner of section 1, Township 1 South, Range 66 West;
thence South along the section lines approximately 36
miles to the Southeast corner of Section 36, Township
6 South, Range 66 West; thence West along the section
lines approximately 22 miles to the Jefferson County
line.
The boundaries of the proposed Region are illustrated in Figure 3.
Figure 4 locates the Region in relation to the rest of Colorado and
surrounding states.
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Figure 3.
PROPOSED
METROPOLITAN DENVER
AIR QUALITY CONTROL
REGION
~
Region
Boundary
LARIMER
Ft. Collins.
WELD
. Greeley
CLEAR
CREEK
PARK
OOUGLAS
ELBERT
MORGAN
ADAMS
ARAPAHOE
SCALE
o 5 10
.
MILES
25
.
I-'
I-'
-------
J
I
,
--l
,
L
UTAH
-- ---
ARIlONA
---,
WYOMING
- -- ---
,-
I
I
I
I
I
I-~-'
Proposed Metropolitan
Denver A~r Quality Control
Region
I
I
I
I
I
I
---t-
J
I
,
I
COLORADO
--
-----
I-'
N
NEW MEXICO
1'1 E BRA S K A
-,
I
\ --
.--
I
I
\
I
,
I
\
I
I-~--
, OKLAHOMA
r---
I
I
---
KANSAS
_.----
-\
,
\
TEXAS
Figure 4.
Relationship of Proposed Metropolitan Denver I
Air Quality Control Region to surrounding areas~
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13
DISCUSSION OF PROPOSAL
Introduction:
To be successful, an air quality control region should meet three
basic conditions. First, its boundaries should encompass most pollution
sources as well as most people and property affected by those sources.
Second, the boundanes should encompass those locations where industrial
and residential development will create significant air pollution
problems in the near future. Third, the boundaries should be chosen
in a way which is compatible with and even fosters unified and
cooperative governmental administration of the air resource throughout
the region. The proposed boundaries of the Metropolitan Denver Air
Quality Control Region were designed to satisfy these three requirements.
As proposed, the Region boundaries coincide with the Denver Air
Basin boundaries established by the State of Colorado during May,
1967. In general, state-defined air basins do not automatically
qualify as air quality control regions. However, the Air Quality
Act of 1967 requires region boundartesto take into account existing
jurisdictions, among other factors. Clearly, a state-designated basin
is an important jurisdictional consideration. Therefore, this study
of the geographic extent of the air pollution problem indirectly
evaluates the suitability of the state-designated basin as a geographic
basis of attack on the problem. As discussed below, the Denver Air Basin
satisfies the three requirements for air quality control region bound-
aries, although certain marginal areas on the outer periphery of the
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14
Basin should be re-examined periodically and included in the Region
if warrented by future population and industrial growth.
The Core Area:
The core area of the proposed Region centers on the City ~f
Denver. Nearly 50 percent of the residents of the metropolitan area
live in the City, the heaviest concentrations of industry and automo-
bile traffic are in the City, and the largest air pollution program
in the area is operated by the City. Suburban communities located
in eastern portions of Jefferson County and western portions of Adams
and Arapahoe Counties are also part of the core area. In these com-
munities, automobiles emit significant amounts of carbon monoxide,
while various point sources are major emitters of particulates. The
analysis of air quality indicates that the suburban residents, more
than 400,000 people, are subjected to air pollutant concentrations
significantly above the background level. Furthermore, industry
and population in these areas are expected to grow rapidly during
the next decade. Thus, Denver City and surrounding suburban areas
represent the core area of the metropolitan air pollution problem,
and clearly should be included in the Metropolitan Denver Air Quality
Control Region.
Areas on the Periphery:
Some communities outside the core area are still linked to
the metropolitan air pollution problem. The emission inventory
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15
reveals important pollutant sources in Boulder County. The air
quality analysis shows that the southeast portion of Boulder County
experiences
carbon monoxide and particulate concentrations which
are above the background level and affect a large majority of the
~)
117,000 residents in the County. The western portions of Boulder
and Jefferson Counties are mountainous areas, have only a small
population, and are essentially unaffected by air pollution from
the Metropolitan areas. Douglas County, on the southern periphery
of the core area, contains less than 7,000 residents, but experiences
pollutant concentrations slightly higher than background levels,
and has a few emission sources. The City of Aurora marks the eastern
edge of the core area. Emission sources, pollutant concentrations
and population density decline sharply to the east of Aurora. The
southwest tip of Weld County contains less than 10,000 residents
and only a few emission sources. But the prevailing southerly wind
carries air pollution from the core area down the South Platte
valley and into this portion of Weld County. The pollutant concentra-
tions are about the same as those in the southeast portion of Boulder
County, and taper off to background levels long before reaching
Greeley, 45 miles northeast of downtown Denver. Greeley contains
less than 40,000 residents. Although significant sources of carbon
monoxide and particulates are located in Greeley, the air pollution
problem which they create is presently separate and independent of
the Denver problem. A twenty mile buffer zone lies between the
Denver core area and Greeley. In addition, Greeley is not closely
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16
linked to Denver on an economic or political level. Particulate
emission sources extend north from Boulder County into Larimer County,
but the air quality analysis did not reveal the presence of air
pollutant concentrations significantly above the background level
in Larimer. The only major population concentration in Larimer
County is Fort Collins, which has fewer than 40,000 residents and
is located about twenty miles north of Boulder County. The mountainous
portions of Boulder and Jeffersqn, the southern portion of Douglas,
the eastern portions of Adams and Arapahoe, and most of Weld and
Larimer Counties are essentially unaffected by air pollution from
the core area.
Growth:
Growth in the Denver area is predicted to expand along a
north-south corridor. The foothills, extending north and south
along the edge of the Rocky Mountains, are attractive residential
areas. Convenient north-south transportation arteries will influence
growth patterns of industrial development. During the next decade,
the bulk of residential expansion is expected to occur in the
suburban areas and in Boulder. Population concentrations are likely
to reach into northern Douglas County and into the southwestern
tip of Weld County. Thus, time will tend to alter the rural character
of Douglas County and to bridge the buffer zone separating Denver
from Fort Collins and Greeley. Although the majority of growth is
expected to occur along the north-south axis, some expansion east-
ward from Aurora is also likely.
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17
Governmental Jurisdictions:
During 1966 the State of Colorado first designated an air
basin for the Denver area. The original Denver Air Basin included
Denver County and parts of Boulder, Jefferson, Douglas, Adams,
and Arapahoe Counties. In 1967 the Basin was extended to include
all of Jefferson and Boulder Counties, in order to facilitate the
administration of air pollution programs throughout those counties.
However, with support from the county governments of Douglas, Adams,
and Arapahoe, the Denver Air Basin continued to include only parts
of these three counties. Colorado State law provides the State
Department of Public Health with authority to enforce emission
standards in the Air Basin, but this authority has been redelegated
to local enforcement agencies. Representatives of the local enforce-
ment agencies have formed the Regional Air Pollution Control Agency
in order to promote uniform emission standards and enforcement pro-
cedures throughout the Basin. An amendment to the State law also
promotes regional cooperation and coordination through a provision
requiring air pollution control agencies to review period~cally
each other's programs and plans.
Summary:
In sum, the evidence seems to indicate that the Denver Air
Basin satisfies the three conditions for establishing air quality
control regions. It contains the important emission sources as
well as the people and property affected by those sources. By
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18
including part of Douglas County it allows room for growth of
industry and population towards the south. Finally, governmental
jurisdictions within the Air Basin have taken initial steps
towards developing a unified and coordinated administration of
air pollution control. However, expected growth patterns suggest
that the southern portions of Weld and Larimer Counties will
beco~e more strongly connected to the metropolitan Denver air
pollution problem with the passage of time. In addition, growth
eastward from Aurora may carry the pollution problem past the
present eastern boundary of the Denver Air Basin. Therefore, the
boundaries of the Metropolitan Denver Air Quality Control Region
should be re-examined periodically to determine if they are keeping
pace with growth in these directions.
Previous proposals for air quality control regions have avoided
splitting county jurisdictions in order to promote ease of admin-
istration of air pollution control. However, when a county is large
and when only a small part of it is involved in an air pollution
problem, ease of administration may dictate the splitting of the
county. Since State and especially local governments will be re~on-
sible
for administering air pollution control in the Region,
they should be given an important voice in determining whether
splitting or not splitting a county is beneficial to overall
administration of a regional program. The existing boundaries of the
Denver Air Basin seem to indicate that program administration is
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19
not hampered by the cutting of Adams, Arapahoe, and Douglas Counties.
When air quality control region boundaries have been designated,
a situation may develop involving a source of pollution on one side
of the region boundary which affects in some real Way air quality
on the other side of the boundary. If adjustment of the boundary
is not a practical way to aleviate the situation, relief should be
found in the control implementation plan which follows the designation.
The plan should contain provisions for the control of sources located
close to but beyond the region boundaries. The level of control for
such sources should depend, in part, upon the degree to which emissions
from the source cause air quality levels to exceed the standards
chosen for application within the region.
The Metropolitan Denver Air Quality Contr~l Region proposed
herein is considered on the whole to be the most cohesive and yet
inclusive area within which an effective regional effort can be
mounted to prevent and control air pollution in the urban area
surrounding Denver. The remaining two sectionsof this report describe
the initial evaluation of urban and engineering factors.
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20
EVALUATION OF URBAN FACTORS
INTRODUCTION
A number of urban factors are relevant to the problem of de-
fining air quality control region boundaries. First, the location of
population is an important consideration, since human activity is the
ultimate source of air pollution, and humans are the ultimate victims.
The population growth pattern is another important consideration,
since an air quality control region should be designed not only for
the present but also for the future. For similar reasons, the location
of industrial activity and the industrial growth pattern are relevant
considerations. Political and jurisdictional factors are also important,
since the 1967 Air Quality Act envisions air pollution programs based
on cooperative efforts among many political jurisdictions. In many urban
areas cooperative arrangements among cities and counties have been
developed for planning and other regional programs. An air quality
control region
should take note of existing regional cooperation
among governmental units and should avoid a combination of jurisdictions
which would irritate local political relationships. It should consider
also the strength of regional cooperation among existing local air
pollution programs. The following discussion of urban factors will
present these considerations as they apply to the Denver area.
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21
POPULATION
Figure 5 displays present population concentrations in the
Denver metropolitan area. About 500,000 people, who represent nearly
50% of the metropolitan population, reside within the City of Denver.
Most of the remainder reside in adjacent suburban areas in Jefferson,
Adams, and Arapahoe Counties. Population outside of the immediate
Denver area spreads generally northward, with concentrations in
Boulder, Fort Collins, Greeley, Brighton, Longmont, and Loveland.
Collectively, these areas contain less than 150,000 residents.
Figure 6 shows expected population growth in the Denver metro-
politan area. Table 1 gives county-wide population projections.
Population growth is expected to occur in the suburbs immediately
south and west of the City of Denver, in the foothills around Boulder,
and north of Denver towards Fort Collins and Greeley. Expansion east-
ward from Denver along interstate highway 70 will probably be less
rapid than expansion north and south along interstate highway 25.
Douglas County will probably remain sparsely populated for at least
10 years except in its northern portion.
INDUSTRY
Figure 7 displays the present location of industrial activity
in the Denver area, according to land use maps. Table 2 indicates land
use by various industrial categories for four counties. Heavy industry
is most densely located in the City of Denver. Jefferson County is the
site of major industrial establishments also. Concentrations of light
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LARIMER
Figure 5
1968 POPULATION DENSITY
Each Dot Represents 5,000 Residents
(approximately 500,000 people
reside in Denver City)
WELD
Ft. Collins .,
.
fJtGreeley
'.
BOULDER
Boulder 111
.
, righton
z
o
en
:::::::
~
u...
r.x...
~
'J
, "
'", ,
" '. " . .
.', .,t..
'~ '
, ,~
.., ,
"
,
DOUGLAS
ELBERT
Sources: Population Estimates, State Budget Office.
1968 Commercial Atlas and Marketing Guide, Rand McNally.
Community Development Area Population, Denver Council of Goverments.
MORGAN
,
ADAMS
ARAPAHOE
N
N
SCALE
o 5 10
.
25
.
MILES
-------
LARIMER
WELD
.
...
.
".
.
BOULDER
.:
~:.
.,., .
.
.:
Figure 6.
ELBERT
.
POPULATION GROWTH: 1968 - 1980
z
55
0::::
r.Ll
~
~
r.Ll
t-;)
Each Dot Represents 5,000
Additional Residents
DOUGLAS
Sources: Population Projection For Colorado Counties, State Budget Office.
Population, Inter-County Regional Planning Commission.
Community Development Area Population, Denver Council Of Governments.
MORGAN
ADAMS
ARAPAHOE
SCALE
o 5 10
.
25
.
MILES
N
W
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24
Table 1.
Denver SMSA Population Projections by County
Year County
Denver
Adams Arapahoe Boulder Denver Jefferson SMSA
1900 4,100 6,200 21,544 140,500 9,306 181,650
1910 8,892 10,263 30,330 213,381 14,231 277,097
1920 14,430 13,766 31,861 256,491 14,400 330,948
1930 20,245 22,647 32,456 287,861 21,810 385,019
1940 22,481 32,150 37,438 322,412 30,725 445,206
1950 40,234 52,125 48,296 415,786 55,687 612,128
1960 120,296 113,426 74,254 493,887 127,520 929,383
1965 156,000 138,000 95,000 505,000 180,000 1,074,000
1970* 175,000 150,000 125,000 525,000 225,000 1,200,000
1975 233,000 193,000 160,000 551,000 275,000 1,412,000
1980 270,000 225,000 200,000 570,000 325,000 1,590,000
1985 325,000 260,000 238,000 595,000 388,000 1,806,000
1990 380,000 295,000 275,000 620,000 450,000 2,020,000
1995 425,000 327,000 313,000 630,000 525,000 2,220,000
2000 470,000 360,000 350,000 640,000 600,000 2,420,000
ICRPC projections based on revised growth rates for the 1965-1970 period.
Sources:
u. S. Census figures for 1900-1960 as of April 1; ICRPC estimates and
projections for 1965-2000 as of January 1.
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25
Table 2. Industrial Land Use (Acres)
Adams Arapahoe Denver Jefferson Total
Manufacturing....... 366.5 123.0 1,386.0 381.0 2,256.5
Storage, Research... 268.5 136.5 1,827.5 149.0 2,381.5
Air Transportation.. 57.0 2,182.0 185.0 2,424.0
Rail Yards.......... 54.0 824.5 878.5
Truck Terminals..... 29.5 552.0 581. 5
Public Utilities.... 194.0 95.5 114.0 297.5 701.0
Survey of 1962 Generalized Land Use in the Denver Metropolitan Region, Master
Plan Report No. 21, ICRPC, Denver, Colorado, December, 1962.
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26
WELD COUNTY
mJ
~
BOULDER COUNTY
ADAMS
COUNTY
~
~
.
.-
JEFFERSON
COUNTY
.
.
ARAPAHOE
COUNTY
t----~----
V
Source: Existing Land (
Use, Master Plan Report \
n:-28, Inter-County J
Regional Planning
Commission, October 1968.
DOUGLAS COUNTY
.
~ Residential Areas
. Industrial Areas
'. .
Figure 7. Preseut Industrial Land Use
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27
industry and warehouse storage are located in Denver and in Commerce
City, just north of Denver in Adams County. Boulder City contains light,
research-oriented industry. Greeley, Longmont, and Brighton contain
industrial activity oriented towards agricultural processing.
Figure 8 shows planned industrial parks and areas zoned for
industrial land use but partially undeveloped. Thus, it indicates
areas where industrial growth is likely to occur. Figure 9 indicates
the major expressway arteries in the Denver metropolitan area.
Significant industrial expansion is likely to occur both within the
City of Denver and also in outlying areas. Industrial growth located
within the urban center will strengthen present commuting patterns
between the suburbs and the center city. Counteracting this trend will
be the attraction which outlying areas offer to large developments
of light industry, storage warehouses, and research firms. These
developments will be economically linked to the Denver urban center
but will be located outside it. In a similar category is the power
plant project which is expected to locate in Platteville.
Figures 5-9 show that present concentrations and expected growth
of population and industry are contained in an area bounded by the
mountains on the west, Fort Collins and Greeley on the north, Brighton
and Aurora on the east, and the northern portion of Douglas County
on the south. Presently there are large open spaces between the Denver
urban center and the two northern communities, Fort Collins and
Greeley. Fort Collins and Greeley have approximately 35,000 to
40,000 residents each. They are located about 45 miles north of down-
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28 ~
~ WELD COUNTY
U
BOULDER COUNTY
ADAMS COUNTY
~ 34
JEFFERSON COUNTY (7
..
~
.
~~
~
LAND ZONED FOR
INDUSTRIAL USE
..
PLANNED INDUSTRIAL
PARKS
Figure 8.
AREAS FOR FUTURE
Source: Existing Land
Use, Master Plan Report
D.28, Inter-County
Regional Planning
Commission, October 1968.
DENVER COUNTY
.
. ARAPAHOE
, COUNTY
.,.
DOUGLAS COUNTY
'\
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Figure 9.
MAJOR EXPRESSWAY
ARTERIES
LARIMER
WELD
BOULDER
ADAMS
ARAPAHOE
N
\0
-------
30
town Denver, and at the present time their economic links with Denver
are not strong. For example, the 1959 traffic study conducted by the
Colorado State Highway Department revealed that on an average day less
than 6,000 motor vehicles (cars and trucks) traveled from the whole
of Larimer and Weld Counties into Denver. Residents of Fort Collins
and Greeley do not generally consider themselves to be part 9f the
Denver metropolitan population. In sum, many indications reveal that
Fort Collins and Greeley are separate from Denver. Growth of populatbn,
industry, and traffic along interstate highway 25 will tend in the
future to bridge existing open spaces. But for the next ten years,
Fort Collins and Greeley will probably retain independence from the
Denver urban center.
EXISTING AIR POLLUTION PROGRAMS
Colorado State law requires the State Department of Public
Health to designate air basins wherever the ambient air exceeds air
quality standards set by the State legislature. The State law further
specifies emission standards which apply only within air basins and
authorizes the State Department of Public Health to enforce those
emission standards. The Department has re-delegated this enforcement
responsibility to those county and local air pollution programs which
have jurisdiction in the air basins. The local programs enforce State
emission standards except in counties which have adopted emission
standards more stringent
than the State standards, where the counties
enforce their own standards.
-------
31
During 1966 the State Department of Public Health designated
the Denver Air Basin. It encompassed Denver County, those portions of
Jefferson and Boulder Counties east of the Rocky Mountains, those
portions of Adams and Arapahoe counties west of range 65 west, and
those portions of Douglas County west of range 65 west and north of
township 7 south. The boundaries of this basin were based on topo-
graphical and meteorological considerations. During 1967, this basin
was enlarged to include all of Jefferson and Boulder Counties, in
accordance with the desires of county enforcement officials. Figure 10
shows the present boundaries. Figure 10 also shows the boundaries of
the Larimer Weld Air Basin, designated by the State in 1967.
Although the State Department of Public Health has re-delegated
enforcement authority to county and local agencies, it retains legal
authority to enforce State emission standards in any area where
local enforcement is considered inadequate. For the most part, the
Department has left enforcement activities in the hands of local
agencies. In the Denver Air Basin, the local enforcement agencies are
the Denver Building Department and the Denver Department of Health
and Hospitals for Denver County; the Tri-county Health Department for
Adams, Arapahoe, and Douglas; the Boulder Health Department for
Boulder County; and the Jefferson Health Department for Jefferson.
The Larimer Weld Air Basin falls under the jurisdiction of the Larimer
and Weld County health departments.
Table 3 shows the approximate total and per-capita budgets of these
local air pollution control programs for 1969. The City of Denver has
-------
JACKSON
LARIMER
Larimer-Weld
Air Basin
~ ~~::.:-:.:.:.:.:.:.:.:.:.,;.;.:.:.: ~~~
GRAND
CLEAR
CREEK
PARK
OOUGLAS
Figure 10.
WELD
AIR BASIN BOUNDARIES
ELBERT
MORGAN
ADAMS
ARAPAHOE
VJ
N
SCALE
o 5 10
.
25
.
MILES
-------
33
Table 3.
Budgets of Air Pollution Control Programs
Total Percapita
Annual Annual
Budget 1969 Budget 1969
County (approximate) (approximate)
Denver $ 302,000 $ 0.59
Boulder 14,000 0.12
Jefferson 38,000 0.18
Tri-County 97,000 0.30
-------
34
by far the largest per-capita annual budget, at $0.59 per resident.
The programs in the surrounding counties have annual budgets on the
order of $0.20 per resident. These differences reflect variations in
the severity of air pollution and in the density of sources among
the counties.
So far, regional cooperation among the local control programs
has been fostered by two actions. First, the Regional Air Pollution
Control Agency (RAPCA), a subcommittee of the Denver Regional Council
of Governments, was established to coordinate standards and enforcement
among member agencies. RAPCA serves as an advisory committee to its
members; its resolutions do not have any binding force. Nonetheless,
all of the member agencies except one have adopted the model air
pollution control code developed by RAPCA. Second, a recent amend-
ment to the Colorado law requires the State Department of Public
Health and local air pollution control agencies to review periodically
each other's programs and plans, and to coordinate air pollution
control efforts on the basis of those reviews. These initial two
methods of strengthening regional cooperation indicate a promising
trend towards coordination of air pollution control efforts within
the Denver Air Basin. This trend is moving towards the goal of the
Air Quality Act of 1967, which calls for state and local administration
of regional air quality control programs. An air quality control region
which coincides with the existing Denver Air Basin would take full
advantage of these hopeful developments towards regional air pollution
control.
-------
35
SUMMARY
At the present time the Denver Air Basin designated ~y the
State of Colorado contains all significant population and industrial
concentrations in the Denver area. Fort Collins and Greeley lie
outside of the Denver Air Basin, but they are independent of the Denver
urban center. Air pollution control agencies have been established to
enforce emission standards throughout the Denver Air Basin. These
agencies concur with the present location of the Basin boundaries.
They have taken initial steps to promote regional cooperation and
uniformity. On the basis of these considerations, it appears that
the boundary of the Metropolitan Denver Air Quality Control Region
should coincide with the existing boundary of the Denver Air Basin.
As growth in the Denver area spreads north and south along the existing
transportation arteries, the boundaries of the Air Qulaity Control
Region should be reconsidered and perhaps extended to include the
southwest tip of Weld County or even the whole Larimer Weld Air Basin,
and a larger portion of Douglas County.
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36
EVALUATION OF ENGINEERING FACTORS
The engineering evaluation for the Denver area was based on
a study of pollutant emissions, meteorology, topography, estimated
air quality levels and available ambient air quality data.
The
emission inventory indicated the location of point and area sources,
the quantity of pollutants emitted from these sources, and the
resulting emission densities.
These data were subsequently used in
a diffusion mode16 to estimate air quality levels in the Denver area.
EMISSION INVENTORY
The National Air Pollution Control Administration* conducted an
inventory of air pollutant emissions for the Denver area.**
Three
major po11utants--su1fur oxides, carbon monoxide, and suspended
particu1ates--have been considered in previous studies by NAPCA to
aid in designating air quality control regions.
Since sulfur oxides
emissions in the Denver area are low~** only carbon monoxide and
suspended particulates are treated as significant pollutants in
this study, and they provide a measure of the general geographic
extent of the overall problem.
Carbon monoxide pollutant levels
~The Air Quality and Emissions Data Program of NAPCA
**For a more detailed treatise, see Appendix A.
***Kansas City's seven county metropolitan area (includes Johnson,
Leavenworth, and Wyandott Counties in Kansas, and Cass, Clay,
Jackson, and Platte counties in Missouri) with a population of
1,288,600 compared to 1,235,000 in the Denver study area, has an
annual SOX emission rate of over 4 times that of the Denver area.
-------
37
provide the best indication of the impact of gasoline-powered motor
vehicles on the regional air pollution pattern since over 94% of all
carbon monoxide emitted in the Denver area comes from motor vehicles.
Particulate emission data provide an indication of the combined effect
of all source categories since emissions of this pollutant are more
evenly distributed among the possible source categories (no single
source category accounts for more than 27% of the total).
Results
of the emission inventory are tabulated in Table A-3 in Appendix A.
The Denver study included emissions estimates for the counties
of Denver, Adams, Arapahoe, Boulder, Jefferson, Larimer, Weld, and
part of Douglas.
This area was divided into the grid coordinate system
shown
in Figure A-I, Appendix A.
The estimated annual emissions
of each of the three pollutants by grid zone were converted to
average daily emissions for three different time periods--annual,
winter, and summerl (Table A-4).
Average annual emission densities for each of the three pollutants
in tons/square mile/day were determined by relating the total
quantity of pollutants emitted in each of the grid zones to the
land area of each zone.
The resulting emission densities are shown
graphically in Figures A-3, A-4, and A-5.
The general pattern of
emission densities for each of the three pollutants is closely
related to the pattern of urbanization in the central part of the
Denver study area.
The highest emission densities occur in or
close to the Denver City area, but the density patterns extend into
all of the remaining counties in the study area.
-------
38
Major point sources contributing to the Denver air pollution
problem are shown in Figure A-2 in Appendix A.
AIR QUALITY ANALYSIS
The geographical distribution of pollutant sources illustrates
the core of the problem area.
It does not, however, elucidate the
extent of the influence of pollution sources on the people and
property located outside the highly urbanized portion of the Denver
metropolitan area.
A study of air quality levels known or estimated
to occur is useful in determining the area affected by the pollution
sources and thus subject to inclusion in the air quality control
region.
Such analysis can be based directly on air quality sampling
data in those instances where the sampling program covers a large-
enough area and has been in existence long enough to provide reliable
patterns of air quality throughout the region under study.
Since
such air quality data rarely exists, it becomes necessary to develop
estimates of prevailing air quality.
Diffusion modeling is a technique
by which such estimates can be made based on the location and quantity
of pollutant emissions and on meteorological conditions.
The influence
of topography on ambient air quality levels is reflected in the results
of the model, but only to the extent that it influences meteorological
conditions.
The diffusion model results become invalid in the Rocky
Mountain Range west of Denver.
The concentration contours presented
in this section, therefore, are dotted in the mountainous area.
The
diffusion model used in this study and the results obtained are
covered in detail in Appendix B.
-------
39
The diffusion model was applied for each of the three pollutants
for three different time periods--annual, winter, and summer.
Figure 11
and Tables B-1 and B-2 show the meteorological data required to apply
the model for each of the three time periods.
Figure 11 shows the
percent frequency of occurrence of wind direction from 1951 through
1960 in Denver for summer, winter, and annual conditions.
T1.1e wind
speed and direction data used in the diffusion model were considered
representative of the prevailing wind patterns throughout the general
Denver area.
Since the Martin-Tikvart mode16 used in this study
attempts to show long-term rather than episodic air quality conditions,
only average emissions and long-term average meteorology are considered.
If episodic data (i.e., data with very low frequency of occurrence)
were used to aid in delineating a region boundary, the region would
be unnecessarily large.
Even the "smaller" region defined on the
basis of mean conditions would undoubtedly encompass the area of
maximum concentration upon which a reduction plan is to be developed.
Some studies2,3,4,S have reported a pronounced diurnal variation in
wind direction with south to southwest winds prevailing in the
morning and evening and an opposing afternoon flow.
The wind rose
data (FigurelU show that the south to southwest winds predominate
but that winds from remaining directions show little variation in
frequency.
Pollutant concentration contours based on mean conditions
for the Denver area show a general SSW-NNE elongation thus reflecting
the predominate wind directions.
The mixing depths for the time periods are an average of the
mean morning and afternoon values as shown in Table B-2 in Appendix B;
-------
I
40
6.4
Figure 11.
Percent frequency
of wind direction
for various averaging
times, based on
1951-1960 data.
4.4
4.0
N
16.2
5
PERCENT
10
15
20
16.6
ANNUAL
4.8
5.7
6.3
4.4
.9
3.6
16.5
15.7
18.3
SUMMER
(June, July, August)
18.4
WINTER
(December,January, February)
-------
41
these data were obtained from the National Weather Records Center
(ESSA).
Combined with wind data, these data are used in the diffusion
model to assess the spatial distribution of pollution concentrations.
The pollutant concentrations estimated by the diffusion model
process are in addition to "background" levels since the model was
not supplied with information on sources located outside the area
initially surveyed.
The results are presented in Figures B-1 through
B-9 in Appendix B as theoretical concentrations and are discussed in
greater detail below.
Sulfur Oxides
Sulfur oxides pollution in the Denver area is not considered a
serious problem.
Emissions are low due to the extensive use of
natural gas and low sulfur coals.
As a result the diffusion model
contour lines for SOX, shown in Figures A-I through A-3 in Appendix A,
indicate relatively low values.
Figure 12,' representing winter
(December, January, and February) conditions, was chosen for dis-
cuss ion since, of the three conditions winter averages were the most
extensive.
Comparison of the diffusion model results with air quality
data shows no significant variation near the core of the study area.
SOx data from the CAMP station located in downtown Denver gives a
winter SOx average of 0.017 ppm (December, 1965, January and Feb-
ruary, 1966) and 0.007 ppm for December, 1967.
This station lies
within the 0.01 ppm contour line produced by the model.
Another
0.01 ppm contour line is located in the Boulder area.
Despite
-------
42
\- \----r ----I
'\ "~~ II ~ i
" ~ ~
"'d" 0 0 (
\\ .~~ ~ II ~ I
'" ~ ~i ~ 0006 I---~
\ ~ I
'\ ~ ~ I
!"-- BOUi.DER~ --1 I
~ COUNT/,~ J' !
/ ,,0. 06 I
L' e 1----- ------1------,
0, .006 ADAMS COUNTY I
--r--" 01 I
"
I " . I
!~ ':::~ j~' ---ARAPAHOECOUNTY-----l
I~ A~A ~-- ~--_._-_.~
U I'
I I DENVER
16 /~ COUNTY
II) A. I
~ A. I
I'; / \ I
1,1 DO~lAS !
LL. __C,?UN_T~_J
I I
o 10
Miles
Figure 12.
1
N
SOx-ppm
Theoretical SOX concentration, winter average, above
background.
-------
43
relatively low SOX values, the diffusion model contours illustrate
the SSW-NNE orientation of the diffusion pattern.
Carbon Monoxide
The results of the theoretical' model estimates of carbon
monoxide concentrations for the three seasonal conditions are
presented in Figures B-4 through B-6 in Appendix B.
The results for
and average summer day are discussed here since, of the three
conditions considered, summer day isop1eths showed the highest cone en-
trations.
Air quality data from Denver's CAMP station indicate
that the model underestimates concentrations by a factor of about
10.*
For the purpose of showing relative distribution of CO levels,
the model estimates are adequate; but they are less adequate for the
purpose of assessing the extent of serious CO concentrations because
of the discrepancy between measured and theoretical values.
The
diffusion model does not reflect the built-up nature of the area in
which most of the CO is emitted and thus assumes that the pollutant
has more immediate space and volume within which to disperse.
This
fact is assumed to cause much of the discrepancy between estimated
and measured concentrations.
Based on this difference, a factor of 10 was applied to the
theoretical diffusion model estimates to give "adjusted" CO cone en-
trations.
In so doing, the relative distribution of CO levels
calculated by the model is preserved, while the absolute values
*
CAMP Station results for June, July,
average CO concentration of 6.9 ppm.
near the 6 ppm contour line given by
for CO in Figure 13.
and August, 1966, give an
The station is located very
the "adjusted" model results
-------
44
assigned to the contours are brought more in line with actual sampling
results.
Tha resulting CO level estimate is shown in Figure 13.
Theoretical contours have been plotted for 6, 2, and 1 ppm of the
pollutant.
1 ppm is assumed to be close to the background level in
most highly urbanized areas; this value at the outskirts of an area,
then, might be used as a starting point in defining the area affected
by sources within the region.
Suspended Particulates
Figures B-7 through B-9 in Appendix B show the diffusion model
results for suspended particulates.
Winter (December, January, and
February) concentration contours give the highest results of the three
time periods considered and will be discussed in this section.
Table 4 shows a comparison of diffusion model estimates and measured
*
suspended particulate data from 14
sampling stations in the Denver
core area.
Measured values were an average of 3.85 times greater
than diffusion model estimates.
In adjusting the model contour lines
by this multiplier, the theoretical isop1eths become comparable to
measured values while the relative concentrations are not disturbed.
Figure 14 shows the "adjusted" theoretical concentration contours
for the Denver area.
Two Hi-Vol samplers are located in Greeley.
The winter averages
(1964-1968 for Central Fire Station and 1966-1968 for fire station
72 fg/m~
Using a factor of 3.85 to adjust the two
are 96 f g/m3 and
isop1eths surrounding
at 23rd and Reservoir Rd.) reported by the stations
Greeley, the values of the contours become more consistant with actual
* Data provided by the Colorado Department of Public Health
-------
LARIMER
CO--ppm
Figure 13.
1-
"-
"
f\.
!'f-.
"i'
~ r:.
~ ""
~ ""
~ f'.
$ /\
/\
""
~""
CJ "
0/\
~/\
.A
/\
BOULDER:
/\
/\
'"
f'...
A
"-
/'-
'A
DOUGLAS
'\
1'\
1\
Adjusted Theoretical CO concentration based
on summer emission levels.
WELD
ELBERT
MORGAN
ADAMS
ARAPAHOE
SCALE
o 5 10
.
25
L
MILES
~
V1
-------
46
Table 4.
Relationship of Diffusion Model Results to
Aerometric Data for Suspended Particulates
County Station Measured Estimated Ratio
M E M/E
Hull Photoa 87 38 2.29
State Health B1dg.a 86 39 2.20
Shwayder Bros.a 146 32 4.56
Denver Sewer P1anta 179 39 4.59
School Adm.a 153 39 3.92
North Higha 114 37 3.08
lAdams Aurorab 89 32 2.78
Adams Citya 156 32 4.87
Arapahoe Eng1ewooda 131 28 4.32
Cherry Creek Damc 41 16 2.56
Lakewoodd 73.5 33 2.23
Jefferson Arvadae 135 30 4.50
Go1dene 92 20 4.60
Boulder a 74.5 10 7.45
Boulder
53.95
Average ratio---53.95 = 3.85
14 -
Averaged over the time periods listed below:
a
December, January, February,
b December, January, February,
c December, January, February,
d December, January, February,
for January, 1966
e February 1967 and December, January, February, 1967-1968
1963-1968
1963-1964 and
1967-1968
1963-1965 and
1966-1968
1966-1968 plus a reading
-------
47
,,- --~-
~ >-,'
/' I- >-
~/' ~I"~
/' u 0
"'I' U
" I' a:: .
'o/' WIO
C/' :::i:;;:;
~I\. iX ~
01\. «'
:::i: /\ -'
:>/,
\. #1 i
)--BOUlDER f
\ COUNTY :::: I
. /\
/ ~
. /'.
L__,:
, ,..
! ~ r'\. 1 -i.RAPA-HOE COUNTy----j
18 I,,~~ - .- --------1
i ~;;.. ! g~~~~
" ~ / f'~ !
,/' DOU~AS I
LL__C_O~NT~__J
,-
'\
'\
\
\
\
---
-,
i
,
r
i---J
I
I
I
I
~o
,
------L----.
ADAMS COUNTY I
I
o 10
Miles
1
N
Particulate -fl9jm3
Figure 14.
Adjusted theoretical suspended particulate concentration,
winter average.
-------
48
measurements (Figure 14).
The Hi-Vol sampler at Cherry Creek Reservoir gives the lowest
winter average suspended particulate values of all stations in the
Denver area.
For winter, 1967-1968 the average suspended particulate
level was 4l;ug/m3 which is considered very close to background level
in the non-urban area surrounding Denver. The region enclosed by
this "background level" isopleth might be considered the area most
affected by particulate emissions in the Denver area.
SUMMARY
The 1 ppm CO contour line encloses the whole of Denver City-
County, the western portions of Adams and Arapahoe Counties, the
southeast corner of Boulder County, the eastern half of Jefferson
County, and the northwest corner of Douglas County.
The 40~g/m3 suspended particulate concentration line includes
essentially the same area as the 1 ppm CO contour; also included is
a portion of west-central Weld County in the Greeley vicinity.
-------
49
REFERENCES
1.
"Rapid Survey Technique for Estimating Conununity Air
Pollution Emissions," PHS Publication No. 999-AP-29,
Environmental Health Series, USDHEW, NCAPC, Cincinnati,
Ohio, October, 1966.
2.
"Report on Graphic Climatology Related to Air Pollution,
Denver, Colorado," Wayne H. May, Air Pollution Control
Section, Colorado Department of Health, Denver, Colorado,
July 1, 1968.
3.
"Air Pollution in the Denver Area," Loren W. Crow,
Certified Consulting Meteorologist, Denver, Colorado.
4.
"Airflow Related to Denver Air Pollution," Loren W. Crow,
Consulting Meteorologist, Denver, Colorado (presented
at the 56th Annual Meeting of APCA, Sheraton-Cadillac
Hotel, June 9-13, 1963, Detroit, Michigan).
5.
"Further Studies of Denver Air Pollution," N. Djordevic,
W. Ehrman, G. Swanson, Elmar R. Reiter (principal
investigator), Atmospheric Science Paper No. 105,
Department of Atmospheric Science, Colorado State
University, Fort Collins, Colorado.
6.
"General Atmospheric Diffusion Model for Estimating
the Effects on Air Quality of One or More Sources,"
Martin, D. and Tikvart, J., Paper No. 68-148, 6lst
Annual Meeting, APCA, St. Paul, Minnesota, June, 1968.
-------
50
APPENDIX A.
APPENDIX B.
APPENDIX C.
APPENDICES
Emission Inventory
Diffusion Model Description and Results
Demographic Data
-------
51
APPENDIX A.
EMISSION INVENTORY
The emission inventory used in this study resulted from a rapid
emission inventory of air pollutant sources in the Denver Metropolitan
area.
The objectives of the inventory were to determine the total
quantities of various air pollutants emitted, using appropriate emis-
sion factors2, and to estimate the geographical and seasonal variation
in air pollutant emissions.
To accomplish this task, the study area
was divided into a grid coordinate system and the emission quantities
were reported in terms of tons of pollutant per grid on an average
annual day, average summer day, and average winter day.
The pollutants considered in this survey are sulfur oxides,
particulates, and carbon monoxide.
Data presented herein are
representative of 1967 and were mainly gathered by State and local
agencies.
The study area, as presented in Figure A-I, consists of the City
and County of Denver, and the Counties of Adams, Arapahoe, Boulder,
Jefferson, Larimer, Weld, and part of Douglas.
For the purposes of
this survey, the study area was divided into 81 grids based on latitude
and longitude.
Five grid sizes of 2 minute, 4 minute, 16 minute, and
32 minute grids were utilized depending upon the extent of urbani-
zation of the area.
Figure A-I indicates the grid system used for
reporting the emissions.
In those cases where sections of outlying
counties are omitted, the air pollutant emissions are considered
negligible.
-------
52
The air pollutant emissions by political jurisdiction are given in
Table A-l.
Table A-2 lists the breakdown of pollutant emissions by
source category in the study area.
The following is a brief summary
of pollutant emissions and sources:
(1)
Of the 31,400 tons of SOX' emitted annually, 67% originate from
fuel combustion sources, 28% from industrial process losses,
and 5% from mobile sources.
The contribution from solid waste
disposal is negligible.
The combustion of coal, mainly in steam
electric power plants, produces 62% of the total sulfur oxides
in the area.
(2)
Particulate emissions from fuel combustion contributes 54%,
solid waste disposal 4%, industrial process losses 27%, and
mobile sources 15% of the 33,400 tons of particulates enlitted
in the study area.
The combustion of coal produces 50% of the
total particulate emissions.
(3)
Mobile sources contribute 94% of the 616,000 tons of CO emitted
per year.
Other sources are the combustion of fuels in stationary
sources which contribute less than 1%, solid waste disposal 1%,
and industrial process losses, 4%.
For the purpose of modeling the air pollutant emissions in the study
area, the emissions are apportioned on the grid coordinate system.
Six-
teen point sources of SOx' 15 point sources of particulates, and 2 point
sources of CO are identified individually with respect to location and
emissions. The emissions for SOx' particulates, and CO are presented
in Tables A_4 and A-5 as average summer day, average winter day, and
-------
53
average annual day estimates.
Figures A-2 through A-5 illustrate
the point source locations and the maximum emission densities of
the three time periods.
The daily emission rates were obtained by dividing yearly totals
by appropriate operating day values.
Fuel combustion was divided
into space heating and constant emissions.
Space heating was appor-
tioned on the basis of degree day variations.
Unless specific data
were obtained from individual sources, industrial, commercial, and
institutional sources were assumed to operate from 250 to 310 days
per year.
Mobile sources and solid waste disposal sources were
assumed to be spread throughout the year.
The seasonal variations in
motor vehicle emissions were based on average daily traffic factors.
-------
:~~it'::::;:::~:::::::::::::::::::~:::::::::::::::::~~::::::~::::::?:::::~:~:::::::::~:::::::::::::::::::::~:::::~:::::::::::~:~~~:~:::::::::::::::::~::::::~::::~~::::::~~:::~::::::::::::::t:~::::
ADAMS
35 36 37 11 13 14 15 16
4/ 43 15 47 49
5/ 18 20 21 ADAMS
.;,.;. '':'::.;.:.:
22 23 24 25
66
::1:,34
"'" it
II'I! 3:3
...
DOUGLAS
76 179 180
8/
DENVER INSERT
72
L ARIME R
2
7
2
Figure A- 1.
WELD
4
o
ARAPAHOE
. see insert)
ELBERT
Emission inventory zones
f'or Denver area study.
VI
"'"
MORGAN
-------
55
Table A-I.
Emissions By Political Jurisdiction
tons/year
County SO Particulate CO
x
Adams 15,100 8,980 94,300
Arapahoe 320 1,180 81,700
I Boulder 5,630 4,550 33,600
Denver 6,950 9,.370 241,600
Jefferson 1,350 4,670 115,700
Larimer 910 2,000 22,200
Weld 1,070 2,600 26,400
Study Area Total 31,330 33,350 615,500
5
-------
56
Table A-2.
Emissions By Source Category In Study Area, 1967
tons/year
Source Category SO Particulate CO
x
Fuel combustion
(Stationary sources)
Coal 19,300 16,700 4,400
Oil 1,000 300 100
Gas 570* 1,200 n
Total 20,870 18,200 4,500
Solid waste disposal
Open burning n 100 970
Incineration n n n
On-site
Backyard 13 550 6,600
Incineration 39 650 2,200
Total 52 1,300 9, 770
Industrial process 8,800 8,900 24,700
Mobile sources
Gasoline combustion 1,000 2,300 563,900
Diesel combustion 500 1,300 800
Railroads 100 300 200
Aircraft n 1,100 11,500
Total 1,600 5,000 576,000
n = negligible
*500 tons/year due to burning of mustard gas.
-------
Table A-3.
Pollutant Emissions by Source Category and Political
Jurisdiction in the Denver Study Area.
County Fuel Conbustion Sources
Ind. Com. & Res. Power Total Ind. Trans. Refuse Total
Inst. Plants Fuel Process Disposal
Adams 1070 130 90 2820 4110 4200 580 80 8980
QJ ~rapahoe 210 140 60 ---- 410 90 680 n 1180
.j.J Boulder 1140 520 140 1520 3320 940 300 4550
C1S n
r-I Denver 680 1570 360 1120 3730 2900 2130 590 9370
::I
() Jefferson 1500 2140 110 3750 230 690 20 4670
.~ ----
.j.J r...arimer 510 120 300 470 1400 250 230 120 2000
1-1
C1S
Pol Weld 1000 150 280 ---- 1430 230 460 480 2600
rota1 6110 4770 1340 5930 ---- 8840 5070 1290 33350
% of Total 18.4 14.3 4.0 17.8 ---- 26.4 15.2 3.9 100
!\dams 440 600 40 7860 8940 6000 n 240 15100
en !\rapahoe 80 40 20 ---- 140 n 190 n 320
QJ Boulder 880 210 80 4240 5410 120 5630
't:I n n
~ Denver 210 380 120 2860 3570 2800 520 30 6950
~
o Jefferson 500 540 40 ---- 1080 n 270 n 1350
1-1 r...arimer 500 30 190 100 820 90 910
::I n n
4-1 Weld 670 40 180 890 170 10 1070
r-I ---- n
::I ota1 3280 1840 670 15060 8800 1360 280 31330
U) ----
~ of Total 10.5 5.9 2.1 48.0 ---- 28.1 4.5 0.9 100
'l.dams 70 40 50 ---- 160 24300 69700 240 94300
QJ ~rapahoe 30 70 10 110 60 81400 10 81700
't:I ----
~ !Boulder 130 290 120 110 650 190 32700 60 33600
~
o penver 50 800 190 90 1130 80 237800 1970 241600
s::
o lJefferson 60 1060 20 1140 114300 220 115700
::0:: ---- n
s:: ,r...arimer 80 70 340 n 490 n 20800 980 22200
o ~e1d 90 90 320 500 19600 6350 26400
,Q ---- n
1-1 lI'ota1 510 2420 1050 200 24630 576300 9830 615500
C1S ----
U ~ of Total neg. 0.4 neg. neg. 4.0 94.0 1.6 100
----
n = not available
VI
-...J
,.
-------
L------- -----------
58
Table A- 4. Summary of Emissions From Area Sources By Season
ton/day
Grid Area SO Particulate CO
x
Sq. KIn. S W A S W A S W A
1 2,741 .0 .0 .0 .01 .01 .01 .69 .57 .61
2 2,741 .47 1.23 .85 2.03 3.88 2.96 44.74 36.56 39.24
3 2,741 .16 .42 .29 .63 .89 .76 12.28 10.52 11.10
4 2,741 .01 .03 .02 .16 .20 .18 3.61 3.03 3.22
5 171.4 .0 .02 .01 .08 .12 .10 1.36 1.11 1.19
6 171. 4 .0 .0 .0 .02 .02 .02 1.31 1.06 1.14
7 171.4 .10 .40 .24 .45 1. 32 .89 21. 27 17.49 18.73
8 171.4 .39 .65 .52 .47 .77 .62 8.25 7.08 7.46
9 171.4 .48 1.33 .91 2.09 4.04 3.07 39.37 33.51 35.43
10 171.4 .08 .08 .08 .08 .08 .08 1.25 1.01 1.09
11 171.4 .0 .02 .01 .04 .08 .06 4.11 3.32 3.58
12 171. 4 .47 1.44 .96 1.40 4.38 2.90 51. 50 41.67 44.89
13 171.4 .49 1.11 .80 2.23 4.10 3.17 22.11 18.17 19.46
14 171. 4 .08 .20 .14 .41 .69 .55 8.57 7.40 7.78
15 171.4 .05 .07 .06 .16 .20 .18 2.67 2.31 2.43
16 171. 4 .0 .0 .0 .19 .19 .19 2.24 2.00 2.08
17 171. 4 .0 .0 .0 .04 .04 .04 5.31 4.29 4.62
18 42.84 .82 1.24 1.03 1.14 1.38 1.26 29.64 23.97 25.83
19 42.84.21 .43 .32 .55 1.17 .86 29.75 24.47 26.20
20 42.84 .04 .04 .04 .10 .10 .10 5.77 4.67 5.03
21 42.84 .07 .07 .07 .27 .27 .27 12.68 10.25 11.05
22 42.84 .27 .63 .45 .73 1.92 1.33 49.43 40.06 43.13
23 171.4 .0 .0 .0 .04 .04 .04 .78 .65 .69
24 171. 4 .0 .0 .0 .11 .11 .11 1.25 1.12 1.16
25 171.4 .0 .0 .0 .0 .0 .0 .46 .37 .40
26 171.4 .07 .07 .07 .15 .15 .15 23.64 19.09 20.58
27 42.84 .36 .60 .48 .71 1.58 1.15 61.09 49.34 53.19
28 42.84 .04 .04 .04 .08 .08 .08 16.20 13.08 14.10
29 171.4 .0 .0 .0 .04 .04 .04 5.74 4.64 5.00
30 171.4 .0 .0 .0 .04 .04 .04 5.74 4.64 5.00
31 171. 4 .0 .0 .0 .05 .05 .05 5.77 4.67 5.03
32 . 171.4 .01 .01 .01 .04 .04 .04 4.08 3.29 3.55
33 171.4 .0 .0 .0 .01 .01 .01 1.63 1.32 1.42
34 42.84 .05 .05 .05 .10 .10 .10 19.02 15.36 16.56
35 42.84 .12 .16 .14 .27 .43 .35 38.10 30.78 33.18
36 42.84 .14 .18 .16 .95 1.03 .99 4~.59 36.01 38.82
37 42.84 .20 .26 .23 .83 .97 .90 33.69 27.27 29.37
38 42.84 .16 .50 .33 .28 1.43 .86 40.37 32.68 35. 20
39 10. 71 .05 .53 .29 .62 .94 .78 13.58 10.98 11. 83
40 10. 71 . 07 .65 .36 .16 2.17 1.17 20.99 17.01 18.31
41 10.71 .10 .20 .15 .20 .28 .24 12.19 9.85 10.62
42 10.71 .12 .26 .19 .36 .80 .58 59.76 48.31 52.06
43 10.71 .09 .15 .12 1.27 1.41 1. 34 15.09 12.19 13 .14
44 10.71 .29 .43 .36 3.30 3.66 3.48 50.43 38.98 42.73
45 10.71 .11 .17 .14 1.63 1. 77 1. 70 15.67 12. 77 13.72
46 10. 71 .15 .41 .28 3.08 3.91 3.50 59.80 48.35 52.10
-------
59'
(Continuation of Table A-4)
Sq. Km.S
SO
x
W
Particulate
co
Grid
Area
A
s
w
A
S
w
A
47 10.71 .08 .16 .12 .79 1.03 .91 20.70 16.73 18.03
48 10.71 .15 .21 .18 .48 .68 .58 23.94 19.37 20.87
49 10.71 .02 .02 .02 .02 .02 .02 3.73 3.01 3.25
50 10.71 .01 .01 .01 2.45 2.45 2.45 32.06 30.93 31. 30
51 171.4 .12 .20 .16 .40 .64 .52 26.12 21.11 22.75
52 42.84 .18 .92 .55 .19 3.15 1.68 33.58 27.27 29.34
53 10.71 .10 .70 .40 .20 2.49 1.35 28.16 22.79 24..55
54 10.71 .05 .23 .14 .10 .64 .37 19.07 15.41 16.61
55 10.71 .09 .31 .20 1.02 1.66 1.34 60.28 48.83 52.58
56 10.71 .08 .20 .14 1.39 1. 79 1.59 36.88 29.83 32.14
57 10.71 .31 1.09 .70 .81 3.28 2.05 111.57 90.19 97.19
58 10.71 .21 .39 .30 1. 76 2.28 2.02 59.83 48.38 52.13
59 10.71 .13 .55 .34 .33 1. 78 1.06 59.77 48.32 52.07
60 10.71 .06 .18 .12 .20 .60 .40 31.90 25.82 27.81
,61 10.71 .09 .29 .19 .23 .99 .61 36.89 29.84 32.15
62 10.71 .04 .06 .05 .06 .22 .14 15.79 12.75 13.75
63 10.71 .32 64 .48 .09 .53 .31 19.72 15.94 17.18
64 10.71 .04 .04 .04 .01 .01 .01 3.91 3.15 3.40
65 42.84 .22 .40 .31 .19 .67 .43 37.37 30.19 32.54
66 42.84 .01 .01 .01 .72 .72 .72 23.31 19.44 20. 71
67 42.84 .07 .07 .07 .10 .16 .13 16.29 13.16 14.19
68 42.84 .27 .35 .31 .74 1.06 .90 41. 77 33.81 36.42
69 42.84 .38 .60 .49 .97 2.02 1.50 53.43 43.18 46.54
70 42.84 .15 .15 .15 .45 .55 .50 31.96 26.63 28.38
71 42.84 .05 .05 .05 .05 .05 .05 13.21 10.67 11.50
72 42.84 .0 .0 .0 .01 .01 .01 2.87 2.32 2.50
73 42.84 .05 .05 .05 .08 .08 .08 16.20 13.08 14.10
74 42.84.13 .15 .14 .27 .39 .33 19.28 15.57 16. 79
75 42.84 .08 .08 .08 .10 .16 .13 16.40 13 . 25 14.38
76 42.84 .04 .04 .04 .04 .06 .05 9.17 7.40 7.98
77 42.84 .02 .02 .02 .05 .05 .05 4.08 3.29 3.55
78 42.84 na na na na na na na na na
79 42.84 na na na na na na na na na
80 42.84 na na na na na na na na na
81 171.4 .04 .04 .04 .08 .08 .08 14.91 12.04 12.98
na = not available (Douglas County)
S = Average summer day
W = Average winter day
A = Average day
-------
60
Table A- 5
Summary of Emissions From Point Sources By SeaSon
ton/day
Type of Plant
Grid
SO
x
Particulate
co
S
w
A
S
w
A
S
w
A
Chemical Plant 56 4.49 4.49 4.49
Chemical Plant 58 3.60 3.60 3.60
Industry 22 0.81 1.20 1.01 4.14 5.70 4.90
Grain Elevator 41 7.70 7.70 7.70
Grain Elevator 47 2.42 2.42 2.42
Industry 13 1.94 2.88 2.41 1.81 2.46 2.18
Industry 21 neg. 4.00 1.43 neg. 10.00 3.60
Industry 9 neg. 2.44 0.89 neg. 6.45 2.32
Federb~ Facility 51 2.20 2.20 2.20
Federal Facility 63 2.11 6.30 4.18
Industry 7 neg. 4.45 1.59 neg. 3.06 1.10
Industry 9 neg. 2.67 0.97 neg. 3.78 1.36
Federal Facility 52 0.05 1.59 0.80 0.19 7.53 3.78
Power Plant 55 1.10 6.20 . 2.95 0.55 2.15 1.15
Power Plant 68 0.53 8.92 4.88 0.55 3.23 1.95
Power Plant 45 16.80 23.20 21. 50 6.03 8.35 7.73
Power Plant 13 11.85 13 . 50 11.60 4.28 4.88 4.18
Power Plant 2 1. 30 1.30 1.30
Refinery 45 16.91 16.91 16.91 27.20 27.20 27.20
Refinery 45 1.80 1.80 1.80 37.00 37.00 37.00
-------
L--
I
I
61
\: ----T -,
\ ~I~ !
. 8'5 (
\ . ~19 I
\ ~.~. r---.-J
\ ~. i
.\- - BOUloER----i II
~ COUNTY .j I
I ' --L
L . ~--..-- ADAMsCOUNTY ----T
--,---, . i
, ~ .. JU --:""'PAHOECOUNTY -----i
!8 ;"'. -~- ._._---~
I ~ I DENVER
~ /' COUNTY
i!!: // DOUGlAS i
LL__~~~__J
I J
o 10
MILES
1
N
. Industrial Sources
. Power Plants
Figure A-2. Major Point Sources
-------
SOx DENSITY
tons/day per mi2
0(0.01
[]ill
Lorimer
Weld
0.01-0.05
0.05-0.10
II >0.10
11I1111111111jll!11
c.I)
~
I~
'w
1-,
I
I
I
I
I
LL~UGLAS
c
o
...
...
QI
ARAPAHOE
QI
-,
/
//
Elbert
Douglas
..._-~..
Figure A- 3.
Sulfur oxides emission density by
zone in study area; annual average.
a-
N
Morgan
-------
CO Density
tons/dIiY/m12
o
Bill
<0.5
0.5 --2
2 ---10
II >10
Larimer
.~
L
I
I
I
; I
! '
DOUGLAS ------1
Weld
:-:':::;:':-:':':-:':',
,',',',',','
.,' ,.. ,','0.
j ~ j j j j j j j j j ~ ~ ~ ~ ~ ~; j ~ ~ j
111.1'1 ~ I ~. [11'i~i II"
.:.:-:.;.:.:-:-:.;.;.:
B~~~:;'::il~\[~dN~
..' ...~1
.... .... .... ... ..-.-
....................,
...................,"
....................,
....................
,.,................,.
,...................
...........,.........
...,...............,
..,..................
...........,........
.............,.......
..........,.........
..... ... .......... ...
,-.." .... ..........
............,......,-
......,.............
....... ... ,_...... ...
....................
..,..,......,........
...,.,......,.......
..,..................
... ... .......,......
.....................
....................
....................
.............,......
.............,......
....................
....................
...........,........
...... ........ ......
------.. -
. Denver
I
../'
/'
./'
Elbert
----
c:
o
..
...
GI
~
7-//
Douglas
Figure A-4. Carbon monoxide emission density by
zone in st.udy area; annual conditions
Morgan
----
0\
LV
-------
Particulate Density
tons/day/mi. 2
o < 0.01
Bf]
Larimer
0.01 ~ 0.10
II
> 0.50
0.10 ~ 0.50
.rlll.'11 !f!t.IIJIJIIIIII
DOUGLAS
ARAPAHOE
Figure A-5.
Weld
Douglas
Elbert
Particulate emission density
by zone in study area; annual
average.
0\
~
Morgan
-------
65
References for Appendix A
1.
"Rapid Survey Technique for Estimating Community Air Pollution
Emissions," PHS, ~ublication No. 999-AP-29, Environmental Health
Series, USDHEW, NCAPC, Cincinnati, Ohio, October 1966.
2.
Duprey, R. L., "A Compilation of Air Pollution Emission Factors,"
USDHEW, PHS, BDPEC, NCAPC, Durham, North Carolina, 1968.
-------
66
APPENDIX B.
DIFFUSION MODEL DESCRIPTION AND RESULTS
Title I, Section 107 (a) (2) of the Air Quality Act of 1967 (Public
Law 90-148, dated November 21, 1967), calls for the designation of air
quality control regions, based on a number of factors, including "atmo-
spheric conditions," interpreted to mean that the boundaries of air
quality control regions should reflect the technical aspects of air
pollution and its dispersion.
Within this guideline, hOwever, the posi-
tion has been taken that region boundaries cannot be based on an extreme
set of circumstances which might have a theoretical chance of occurrence.
Hence, the analysis of a region's atmospheric dilution potentia~ is largely
based on mean annual values, although summer and winter mean values are
analyzed with respect to reviewing seasonal variations in meteorology and
pollutant emissions.
With the realization that the meteorological analysis would help
define tentative boundaries only and that final boundaries would be
developed subsequently to reflect local government aspects, it was decided
that the meteorological assessment should be as unpretentious as possible.
Accordingly, the widely accepted long-term Gaussian diffusion equation,
:1 2
described by Pasqui11 and Turner, has been applied with a few modifi-
cations to accommodate certain requirements inherent to the delineation
of air quality control regions.
In summary, the Gaussian diffusion
equation is utilized to provide a theoretical estimate of the geographical
distribution of long-period mean ground-level concentrations of SOX' CO,
and suspended particulates.
The model used has the necessary flexibility
to utilize information on emissions from both point and area-wide sources.
-------
67
To maintain simplicity, all pollutant sources were assumed to be
at ground level; for CO this assumption is realistic.
The same assump-
tion is used for major point sources of SOX and particulates, since the
distances of interest are sufficiently great to obviate the source-
height effect for most receptors.
Also, since there is no agreement
on an appropriate half-life and deposition rate for SOX and particulates,
respectively, these factors were not applied to the computations of
ground-level pollutant concentrations during the initial diffusion
model analysis.
METHODOLOGY
The diffusion model used is based on the Gaussian diffusion
equationl,2, as modified by Martin3.
Essentially, the model sums the
effects (ground-level concentration) of a number of sources (area and
point) for a specified number of receptors, averaged over a season
or a year.
For this study, 97 receptor points were used ( 20, 30, 40,
50, 70, and 100 kilometers from an assumed center, at each of 16
compass points).
The meteorological data input to the model is screened to
determine the representiveness of the data.
Appropriate surface wind
rose data are selected from U.S. Weather Bureau records; if necessary,
special wind data tabulutions are obtained from the National Weather
Records Center (NWRC).
Table B-1 presents the wind data in the form
utilized by the diffusion model.
The data are given in terms of a
ratio of the relative frequency (F) with which a particular wind
direction occurs to the effective wind speed (u) for the respective
direction.
The mean mixing depth for each region, for each
-------
68
respective time period (seasonal and average), is determined on the basis
4 5
of computed mixing depths documented by Holzworth' , and recent tabula-
tions furnished the Meteorology Program by the National Weather Records
Center (ESSA).
Table B-2 gives the mixing depth values utilized by the
model for computing theoretical ground level concentrations in the Denver
area.
Figures B-1 through B-9 present unmodified theoretical ground level
concentrations of SOX' CO, and suspended particulates during the three
time periods, annual, summer, and winter.
-------
Table B-1.
Denver Region ~ind Rose Data
Flu
SEASON N NNE NE ENE E ESE SE SSE S SSW SW WSW W WNW NW NNW
WINTER
(Dec., Jan., Feb.) 2.06 2.26 1.85 1. 75 1.42 1.54 2.01 2.19 5.65 5.57 2.05. 1.32 1.25 1.93 2.18 1.5
SUMMER
(June, July, Aug.) 2.16 2.11 1. 87 1.92 1.83 1.62 1.93 2.12 5.19 5.72 2.95 2.27 1. 75 1.86 2.53 2.19
ANNUAL 2.15 2,.31 1. 96 1.90 1. 75 1.73 1.95 2.21 5.26 5.34 2.30 1.68 1.39 1.77 2.37 1.93
I I
F = Relative frequency of occurrence of wind direction.
U = Effective Wind speed (meters/second).
0-
\0
-------
,--
70
Table B-2. Average Mixing Depths
for Denver Area by Season
Season Mixing Depths. meters
Morning Afternoon Average,
Average Average morning and after-
noon
Winter (Dec.,
Jan.. Feb.) 178 1357 768
Summer (June,
July, AURust) 243 3358 1800
Annual
(4 seasons) 236 2438 1337
!:Jt
-------
LARIMER
002
80 --ppm
X
Figure Bl. Theoretical SOX
Concentration--Annual Average
Above background.
DCUGLAS
WELD
ELBERT
K1RGAN
ADAMS
ARAPAOOE
SCALE
o 5 10
MILES
2S
'I
.--.----
.....
......
-------
LARIMER
SOx--pp
Figure B2. Theoretical SOX
Concentration--Summer Average,
Above background.
BOULDER
z
@
ex:
~
~
~
~
'J
DOOGLAS
WELD
ELBERT
MORGAN
ADAMS
ARAPAHOE
SCALE
o 5 10
.
MILES
~
N
25
.
-------
,-
LARIMER
SO --ppm
X
Figure B3. Theoretical SOx
Concentration--Winter Average
Above background.
.002
OOJGLAS
WELD
ELBERT
~RGAN
ADAMS
ARAPAHOE
SCALE
o 5 10
.
MILES
25
.
........
UJ
-------
LARIMER
CO--pp
Figure B-4. Theoretical CO
Concentration--Annual Average,
Above background.
BOULDER
WELD
DOUGLAS
ELBERT
MORGAN
ADAMS
ARAPAHOE
"
SCALE
o 5 10
.
MILES
--.J
~
25
1
-------
LARIMER
CO--ppm
Figure ~-S. Theoretical CO
Concentration--Summer Average
Above background.
BCXJWER
DOOGLAS
WELD
ELBERT
M)RGAN
ADAMS
ARAPAHOE
SCALE
o 5 10
~-
MILES
25
.
'-I
VI
-------
LARIMER
CO--ppm
Figure B-6. Theoretical CO
Concentration--Winter Average,
Above background.
BOULDER
WELD
DOUGLAS
ELBERT
MORGAN
ADAMS
ARAPAHOE
SCALE
o 5 10
.
MILES
-...J
0\
25
.
-------
.
LARIMER
Particulate~g/m
Figure B-1. Theoretical
Particulate Concentration--
Annual Average, above back-
ground.
- ---.- -~- -
-.-.- -
BalLDER
WELD
OOlGLAS
ELBERT
MORGAN
ADAMS
ARAPAfI)E
SCALE
o 5 10
.
MILES
25
.
'-J
'-J
-------
LARIMER
BOULDER
particulate-~g/m3
Figure B-8. Theoretical Particulate
Concentration--Summer Average,
Above Background.
WELD
z
@
c:x:
~
~
~
~
I-)
DOOGLAS
ELBERT
MORGAN
ADAMS
ARAPAHOE
-
SCALE
o 5 10
.-----
MILES
......
00
25
1
-------
LARIMER
particulatej48/m3
Figure B-9. Theoretical
Particulate Concentration--
Winter Average, Above Background.
WELD
BOOLDER
DOOGLAS
ELBERT
MORGAN
ADAMS
ARAPAHOE
SCALE
o 5 10
.
MILES
25
I
"
\0
-------
80
References for Appendix B
1.
Pasquill, F., "The Estimation of the Dispersion of Windborn
Material," Meteorology Magazine, 90, 1963, pp. 33-49.
2.
Turner, D. B., "Workbook of Atmospheric Dispersion Estimates,"
USDHEW, Cincinnati, Ohio, 1967.
3.
Martin, D. 0., and Tikvart, J. A., "General Atmospheric Diffusion
Model for Estimating. the Effects on Air Quality of One or More
Sources," Paper No. 68-148, 6lst Annual Meeting, APCA, St. Paul,
Minnesota, June, 1968
4.
Holzworth, G. C., "Mixing Depths, Wind Speeds and Air Pollution
Potential for Selected Locations in the United States," J. Appl.
Meteor., No.6, December, 1967, pp. 1039-1044.
5.
Holzworth, G. C., "Estimates of Mean Maximum Mixing Depths in the
Contiguous United States," Mon. Weather Rev. 92, No.5, May, 1964,
pp. .235-.24.2.
~1r@LQJ~~ Of 1
~ ~ A lLD ~1r(zHi1f
Ruf?> NCC ~7111
------- |