PROPOSED NATIONAL AMBIENT
AIR QUALITY STANDARDS FOR
CARBON MONOXIDE
DRAFT
ENVIRONMENTAL IMPACT STATEMEN1
STRATEGIES AND AIR STANDARDS DIVISION
OFFICE OF AIR QUALITY PLANNING AND STANDARDS
U.S. ENVIRONMENTAL PROTECTION AGENCY
Research Triangle Park, North Carolina 27711
July 1980
-------
TABLE OF CONTENTS
LIST OF ILLUSTRATIONS . . . iii
LIST OF TABLES iv
1. CONCLUSIONS 1
1.1 Nature of the Proposed Action 1
1.2 Non Attainment Areas 1
1.3 Summary of Environmental Impacts 1
1.3.1 Biological, Ecosystems and Esthetics Impacts . . 1
1.3.2 Ambient CO Levels 4
1.3.3 Energy Impacts 4
2. INTRODUCTION AND BACKGROUND 6
2.1 Introduction 6
2.2 Background .•' 6
3. DESCRIPTION OF THE PROPOSED ACTIONS 11
3.1 Alternative Standards Investigated ..... 11
3.1.1 Allowable Concentrations and Averaging Times - • 11
3.1.2 Compliance Schedule 11
3.2 Monitoring Methods 13
4. DESCRIPTION OF SOURCES AND AMBIENT CONCENTRATIONS OF CO . • 14
4.1 Ambient CO Formation 14
4.2 Sources of CO in Ambient Air 16
4.2.1 Natural Sources 16
4.2.2 Man-Made Sources 16
4.3 Ambient Concentrations and Total Emissions of CO . . '. 18
4.3.1 Trends in Ambient Concentrations of CO 19
4.3.2 Existing Ambient Concentrations of CO 31
4.3.3 Trends in Nationwide CO Emissions 36
4.3.4 Projected Ambient Emissions of CO in the
Absence of Proposed Action • 40
5. CARBON MONOXIDE CONTROL OPTIONS 46
5.1 Control Options Related to Mobile Sources 46
-------
5.1.1 Control for New Mobile Sources 46
5.1.2 Inspection and Maintenance Programs 50
5.1.3 Transportation Control Measures (TCM) Programs ... 53
5.2 Control Options Related to Stationary Sources 60
5.2.1 Traditional Control Options 60
5.2.2 Nontraditional Control Methods 62
5.2.3 Effectiveness of Stationary Source Control Options . 68
5.2.4 Resource Utilization 69
5.3 Prevention of Significant Deterioration (PSD) 70
6. PRIMARY ENVIRONMENTAL IMPACTS OF THE PROPOSED ACTIONS 74
6.1 General 74
6.2 Air Quality • 75
6.3 Energy Impacts 78
.7. SECONDARY ENVIRONMENTAL IMPACTS OF THE PROPOSED ACTIONS . . . . 82
7.1 Other Air Pollutants 82
7.1.1 Mobile Source Controls '. 82
7.2 Alteration of Atmospheric Properties 83
7.3 Water Quality 84
7.4 Ecosystems 85
7.5 Esthetics . . . .' 88
8. OTHER RELATED CONSIDERATIONS 90
8.1 Potential Mitigating Measures 90
8.2 Unavoidable Adverse Impacts 90
8.2.1 Air Quality 90
8.2.2 Water Quality 90
8.2.3 Ecosystems 90
8.2.4 Esthetics 91
8.3 Relationship between Short-Term Uses of Man's Environ-
ment and Enhancement of Long Term Productivity 91
8.4 Irreversible and Irretrievable Commitment of Resources . . 91
APPENDICES
A Non Attainment Areas for CO NAACS (1978) 92
B List of the 272 Counties Included in the County Files ... 96
C Methodology to Project CO Emissions and Analyze the
Effects of I/M and TCM Programs 99
ii
-------
ILLUSTRATIONS
4-1 Relationship between Air-Fuel Ratio and Concentration
Percent by Volume 15
4-2a Hourly Variations of Ambient CO Concentrations for
Los Angeles, CA 22
4-2b Hourly Variations of Ambient CO Concentrations for
Baltimore, MD 23
4-3 8-Hour Average Concentrations of Ambient CO for
Washington, B.C. CAMP Station " 25
4-4 Seasonal Variations of Ambient CO Concentrations for
Baltimore, MD 26
4-5 Seasonal Variations of Ambinet CO Concentrations for
Los Angeles, CA 27
4-6 Annual Variations of Ambient CO Concentrations for
Baltimore, MD 29
4-7 Annual Variations of Ambinet CO Concentrations for
Los Angeles, CA 30
4-S Histogram of 8-Hour Design Values of CO and the Number
of Counties having Design Values in Various Ranges ...... 35
4-9 Trends in CO Emissions (based on Table 4-5) 38
iii
-------
TABLES
1-1 Alternative CO Standards Under Consideration 2
1-2 Non Attainment Areas (Counties) in 1987 3
3-1 Alternative CO Standards Under Consideration 12
4-1 Nationwide Emission Estimates', 1977 17
4-2 List of Counties in Violation of Current 1-Hour
Standards of CO - 40 ing/m3 (1976/1977) 33
.4-3 Counties in Violation of Current 8-Hour Standard for
CO: 10 mg/m3 34
4-4 Summary of Total Nationwide CO Emissions, 1970-1977 ... 36
4-5 Nationwide CO Emissions from Various Sources, 1970-1977. . 37
4-6 Current and Projected Total CO Emissions and Number of
Non Attainment Counties Considering Only the Federal
Motor Vehicle Emission Control Program (FMVECP) 43
5-1 Carbon Monoxide Control Techniques for New Mobile Sources. 48
5-2 Carbon Monoxide Emission Reduction from I/M Programs ... 52
5-3 Percentage Reduction Accomplished in Mobile Source
Emissions in Target Year 1987 with 30% Stringency
I/M using Mobile 1 Output 54
5-4 Example of TCM Programs 56
6-1 Status and Number of Counties Projected to be in
Violation of Various Standards in 1987 76
6-2 Estimated Fuel Savings in 1987 Due to I/M and TCM
Programs to Meet Varius CO Standards 80
C-l Basic County Related Data Stored in the County File . . . 100
IV
-------
1.' CONCLUSIONS
1.1 Nature of the Proposed Action
This Draft Environmental Impact Report examines potential environ-
mental effects of implementing various National Ambient Air Quality
Standards for Carbon Monoxide (CO). Fourteen possible standards are
assessed, seven of which are one-hour standards and the other seven are
eight-hour standards as shown in Table 1-1.
1.2 Non Attainment Areas
The number of counties projected to be in non attainment of each
alternative in 1987 with only Federal Motor Vehicle Emission Control
Program (FMVECP) and with FMVEC? plus additional Inspection an/ Mainten-
ance (I/M) and Transportation Control Measures (TCM) programs are
indicated in Table 1-2 considering two scenarios. The basic assumptions
associated with each of two scenarios are also indicated in Table 1-2.
1.3 Summary of Environmental Impacts
1.3.1 Biological, Ecosystems and Esthetics Impacts
Controlling CO emissions to meet any of the proposed standards will
result in beneficial biological, ecosystems and esthetics impacts. In
fact the very motivation of implementing the FMVEC program was the reali-
zation that high emission levels of CO from automobiles were found to
2
have detrimental effects on human health.
Carbon monoxide is not considered a hazardous or toxic pollutant in
drinking water and, therefore, any reduction in CO emissions as a result
-------
Table i-l
ALTERNATIVE CO STANDARDS UNDER CONSIDERATION
One-Hour Standard
Konometric SI Equivalent
Eight-Hour St;mdard
Konometric SI Equivalent
M) (nig /in 3)
35 40
35 40^]
25 [ 29
15 J 17
35^ 4o"|
25 > 29?
15 J J
Annual Second
High Existing
> Statistical, on
an annual maxi-
mum basis *
Statistical, on
a daily maxi-
mum basis //
(PPM) (mg/m3)
9 10
N \
12 14
9 I 10
7 8
/ /
12 > U -
9 / 10 ^
7
Annual Second
High Existing
Statistical, on
an annual maxi-
mum basis *
Statistical, on
a daily maximum
basis //
* Where the expected number of annual maximum exceedances is
-------
Table 1-2
NON ATTAINMENT AKEAS (COUNTIES) IN 1%7
Standards
One-Hour Standards
3
40 mg/M Second high
40 inb/M3 Statistical
40 mg/M" Daily maximum
29 mg/M3 Statistical
3
29 mg/M Daily maximum
3
17 mg/M Statistical
17 mg/M Daily maximum
!. Eight-Hour Standards
10 mg/M3 Second high
10 wg/M Statistical
10 mg/M Daily maximum
3
14 mg/M Statistical
14 mg/M Daily maximum
3
8 mg/M Statistical
3
8 mg/M Daily maximum
Scenario 1
• VMT growth rates historical and county specific
o Area emissions population proportional
• Point emissions national manufacturing income
proportion
<» All sources fully effective in producing
CO concentrations
• I/M effectiveness factors reduced by 0.5
for <50°F
with only
FMVECP
2
2
2
11
10
56
51
79
89
68
30
21
123
116
with FMVECP
and I/M and TCM
2
2
2
4
5
39
38
44
57
43
15
9
99
87
Scenario 2
o VMT growth rate IX annual
• Area emission growth IX annual
• Point source as in scenario 1
• 20% area, 0% point, 100% line source,
effectiveness
o I/M factors not changed
with only
FMVECP
0
0
0
0
0
26
27
24
32
19
5
2
73
57
with FMVECP
and I/M and TCM
0
0
0
0
0
6
6
3
7
2
2
0
24
13
Source: Results generated by SRI International's computer program.
-------
of proposed standards will have no effect on water quality.
Plants are relatively resistant to Carbon Monoxide compared to
several other major air pollutants such as SO™, CL and HC. Consequently,
any reduction in CO emissions as a result of proposed standards will have
4 5
no effect on plant life. '
CO being a colorless, odorless and tasteless gas does not create
any problems related to esthetics. As a matter of fact, a reduction in
CO in the atmosphere might be helpful in reducing the smog problems
6
since the presence of CO contributes in the formation of smog.
1.3.2 Ambient CO Levels
In urban areas having a CO ambient air quality problem, reducing
the CO emissions through FMVECP, I/M and TCM programs to meet various al-
ternative standards should reduce peak CO levels.
1.3.3 Energy Impacts
The setting up of various standards and implementation of I/M and
TCM programs should result in some saving in gasoline consumption by
automobiles. These savings could potentially be of the order of hundreds
of millions of gallons per year as shown in Chapter 6 of this report.
-------
REFERENCES CITED IN CHAPTER 1
1. SRI International, Computor Aided Methodologies to Conduct
Regulatory Impact Analysis of Ambient Air Quality Standards
for Carbon'Monoxide, Menlo Park, California, September 1979
(SRI project 6780).
2. Office of Research and Development, Air Quality Criteria for Carbon
Monoxide, External Review Draft, Research Triangle Park, North
Carolina, U.S. Environmental Protection Agency, November 1978.
3. Toxic Materials News, March 21, 1979.
4. Chakrabarti, A.G., "Effects of Carbon Monoxide and Nitrogen Dioxide
on Garden Peas and Stringfaeans," 1976 (Bull. Environ. Contam. Toxical.
15: 214-22).
5. Bidwell, R.G.S., and D. E..Frazer,"Carbon Monoxide Uptake and
Metabolism by Leaves," 1972 (Can. J. of Botany 50: 1435-1439).
6. Calvert, J.G., "Hydrocarbon Involvement in Photochemical Smog",
Environmental'Science and 'Technology, Vol. 10, Number 3, 1976,
pp. 256-262.
-------
2. INTRODUCTION AND BACKGROUND
2.1 Introduction
The National Environmental Policy Act of 1969 (PI 91-190) requires that
federal agencies prepare detailed environmental statements on major
federal actions that significantly affect the quality of the human
environment. In 1973,. federal courts determined that the EPA was not
required to prepare such statements if they related to environmentally
protective activities. Nevertheless, the Agency has been urged to
prepare them through a U.S. House of Representatives Resolution (H. R.
Rep. No. 93-520) in 1973 and the passage of a public law in 1974 (PL 92-
135) that appropriated funds for that purpose. As a result, the EPA
decided to voluntarily prepare environmental impact statements in connec-
tion with its major regulatory actions that include the promulgation
of national ambient air quality standards. This EIS, which deals with
alternative carbon monoxide standards, is a result of that decision.
2.2 Background
Federal legislation related to air pollution began in 1955 with passage
of the Air Pollution Control Act. However, it was not until 15 years
later that federal legislation called for ambient air quality standards
for various pollutants. The Clean Air Act of 1970 (PL 91-604, Section
108) directed that the Administrator of EPA publish a list of air pollu-
tants that appeared to endanger public health or welfare and that air
quality criteria for these pollutants be issued within one year* As a
result of these actions, standards were set for six pollutants, one of
-------
which was carbon monoxide, in April 1971.
The primary (public health) and secondary (public welfare) standards
set for carbon monoxide were the same:
Maximum mean
8 hours Not to exceed once per year 10 milligrams per cubic
meter (9 p.p.m.)
1 hour Not to exceed once per year 40 milligrams per cubic
meter (35 p.p.m.)
Note:
These standards have been in effect for the past eight years.
In 1977, Congress passed The Clean Air Amendments Act of 1977 (PL 95-95,
Section 109), which required that the Administrator of EPA complete a
thorough review of the pollutant criteria and standards by not later
than December 31, 1980 and at least every five years therafter. He will
promulgate new standards as appropriate.
The EPA review of carbon monoxide was set for 1979. In November 1978,
an external review draft of Air Quality Criteria for Carbon Monoxide was
published and circulated for comments on its technical accuracy and
policy implications.1 A revised external review draft was published in
April 1979. This version was reviewed by the Clean Air Scientific Ad-
visory Committee of EPA's Science Advisory Board on June 15, 1979. Minor
revisions will be made to the report, and it will be released in final
form when CO standard is formally proposed.
-------
Because this draft Environmental Impact Statement (EIS) was developed
before a decision was reached on a specific proposed standard level,
the analysis covers a range of ambient CO levels considered to be prob-
able candidate standards. These are listed in Section 3.
The EIS employs actual and estimated air quality data, adjusted for
growth, to predict areas of the country which may exceed a particular
proposed standard by a particular date. The percentage emissions reduc-
tion necessary to attain each proposed standard is calculated using the
linear rollback approach. The extent of the required rollback is influ-
enced heavily, by the large emission reductions expected with the imple-
mentation of Federal Motor Vehicle Emission standards for motor vehicles.
The EIS describes the effectiveness of implementing additional emissions
controls on mobile and stationary sources selected to meet the various
proposed standards. Additional Mobile source control strategies in-
clude the inspection and maintenance program and local and area-wide
transportation system management strategies. Other resources affected
by establishing and implementing a short-term CO standard are discussed
also, including fuel consumption.
Primary and secondary environmental impacts of the proposed action are
identified and assessed for each of four potential impact areas; air •
quality, water quality, natural ecosystems, and esthetic values. Poten-
tial mitigating actions also are identified and assessed where appro-
priate. Finally, the EIS summarizes the unavoidable adverse impacts
P
associated with the proposed short-tern standard, as well as (1) the
-------
relationship between short-term environmental use and long-term
productivity, (2) irreversible and irretrievable commitment of re-
sources needed to implement the NAAOS, and (3) alternatives to the pro-
posed action.
Much of the input data used in this analysis is derived from the
documents listed under "References" at the end of each chapter.
These sources are discussed in the EIS or incorporated by reference
where appropriate.
-------
REFERENCE CITED IN CHAPTER 2
1. Office of Research and Development, Air Quality Criteria for Carbon
Monoxide, External Review Draft, Research Triangle Park, North
Carolina, U.S. Environmental Protection Agency, November 1978.
10
-------
3. DESCRIPTION OF THE PROPOSED ACTIONS
3.1 Alternative Standards Investigated
3.1.1 Allowable Concentrations and Averaging Times
The EPA is considering 7 one-hour and 7 eight-hour alternative
ambient CO standards as shown in Table 3-1. The first one-hour stan-
dard and the first eight-hour standard in this table are the existing
standards that have been in effect for the past eight years. The other
alternative standards shown in Table 3-1 are currently being investi-
gated for their suitability in comparison to current standards. The
. statistical form of standards take into account the probability of
unusual meteorological occurances which could cause unusually high
CO levels. Proposed actions, in addition to the Federal Motor Vehicle
Emission Control program, include Inspection and Maintenance (1/11) pro-
grams and Transportation Control Measures (TCM) for Automobile and installa-
tion of suitable devices for stationary sources of CO.
3.1.2 Compliance Schedule
The Clean Air Act Amendments of 1977 (Section 110) require that
if the Administrator sets new ambient air quality standards, each State
shall, after reasonable notice and public hearing, adopt and submit a
plan that provides for implementation, maintenance, and enforcement of
those standards within nine months. The Amendments (Section 172) require
that plans provide for attainment of national primary ambient air quality
standards related to CO and 0- not later than December 31, 1982'. If the
State demonstrates that this attainment is not possible by that date despite
implementing all reasonably available measures, including inspection
and maintenance of automobiles, provisions for attainment must be made
not later than December 31, 1987.
11
-------
K)
Table 3-1
ALTERNATIVE CO STANDARDS UNDER CONSIDERATION
One-Hour Standard
Konometric SI Equivalent
(mg/m3)
(PPM)
35
35
25
15
40
29
17
/
«
\
35
25
15
40
> 29
17
40 Annual Second
High Existing
Statistical, on
an annual maxi-
mum basis *
Statistical, on
a daily maxi-
mum basis II
Eight-Hour Standard
Konometric SI Equivalent
(mg/m3)
(PPM)
9
\
10 Annual Second
High Existing
12
9
7
14
10
8
14
10
8
Statistical, on
an annual maxi-
mum basis *•
Statistical, on
a daily maximum
basis tf
* Where the expected number of annual maximum exceedances is ^ 1 per year.
// Where the expected number of daily maximum exceedances is ^ 1 per year.
-------
3.2 Monitoring Methods
In 1971, the EPA specified nondispersive infrared (NDIR) analyzers as
*
the reference method for continuous measurement of CO. Automatic
NDIR analyzers are the most common method for measuring CO in urban
areas. The method used is relatively reliable and is based on the
absorption of infrared radiation by CO. Water vapor and C02 interfere
in the process, but filter cells and treatment of the incoming gas
are used to minimize the interferences. Because of its importance,
EPA has issued specifications for calibration and data quality of the
monitors.
Gas chromatographic analyzers provide an alternative method for moni-
toring. This method offers greater sensitivity than NDIR, a wide
linear range, and a high degree of specificity. It therefore is more
\
often used for measuring^, nonurban or global background levels where
concentrations may be as low as 0.1 to 1 ppm.
Other methods for measuring atmospheric concentrations have been
developed, but they have not been evaluated for routine monitoring.
California is the major contributor to the national CO data base with
59 CO monitoring sites. As of 1977, there were 456 monitors nationwide
Approximately 200 monitors provided three or more years of CO history,
while 75 provided five or more years of CO history.
Federal Register 36, No. 84, 8186-8201 (.1971)
13
-------
4. DESCRIPTION OF SOURCES AND AMBIENT CONCENTRATIONS OF CO
4.1 Ambient CO Formation
Carbon monoxide is a colorless, odorless, tasteless gas. It is emitted
into the atmosphere in greater quantities than any other urban air
pollutant. In 1976, the total U.S. emissions of suspended particulates,
sulphur oxides, nitrogen oxides, and hydrocarbons only slightly exceeded
that -of carbon monoxide—91.2 million metric tons vs. 87.2 million metric
tons of CO.
Carbon monoxide arises primarily from incomplete or inefficient combustion
of carbon or carbon-containing substances, such as gasoline, wood, or
coal. That is, it is formed when these substances are burned in a
limited supply of air or oxygen. The result of the incomplete combustion
is the combination of one carbon atom with one oxygen atom into CO.
Because air is used in. an internal combustion engine, carbon monoxide
(as well as other pollutants) are formed in- the engine and emitted through
the exhaust. Concentrations of combustion by-products are influenced by
several factors, but the most important is the air-fuel ratio.
For a given amount of fuel, a precise amount of air is required for
complete combustion according to the fundamental relationship:
C H + (X + 1/4Y) 0 + X C09 -t- 1/2Y HO
X y £ to £f
If less than the "correct" amount of oxygen (air) is included in the
mixture, it is considered to be "rich", i.e., rich .in fuel. If excess
14
-------
oxygen is introduced, the mixture is said to be "lean", i.e., deficient
in fuel. The chemically correct mixture, in which the carbon, hydrogen
and oxygen are in balance according to the equation above, is called a
stoichiometric mixture. Figure 4-1 shows the relationship between air-
fuel ratio and concentration percent by volume. The stoichiometric mixture
requires about 14-1/2 pounds of air per pound of gasoline. This would imply
a 14.5:1 air-fuel ratio. A 12:1 air-fuel ratio is considered to be decidedly
rich, while a 17:1 ratio is quite lean. Combustion of rich mixtures
produces carbon monoxide and tends to result in residual fuel in the
exhaust, either unburned or only partially burned. The use of lean •
mixtures produces much less CO. However, if the mixture is excessively
lean, the engine will misfire and all emissions may be quite high.
o z
Z U4
1= O
CORRECT
XTURE
IU
3
S
4
2
n
\.
\
\
III i
! Ml !
1
i ill 1 1
1 Ml 1
X i III !/-«R80N I
\ 1 111 / '•'QNOXIOE i
XI II! fl . i
X M ! /i
1 NJ i 1 / !
1 NL 1 / i
1 i iV^
1
i
10 11 12 13 U 15 IS 17 13 19
AIR: FUEL RATIO
Figure 4-1. Relationship Between Air-Fuel Ratio and
Concentration Percent by Volume.
Source': Greiner Engineering Sciences, Inc. 'Fundamentals of Air Quality.
Washington D. C.: Offices of Research and Development, Federal
Highway Administration, U.S. Department of Transportation.
-------
4.2 Sources of CO in Ambient Air
4.2.1 Natural Sources
The major natural known sources of CO are methane oxidation, hydrocarbon
oxidation, oceans, plants, forest fires, and rainwater. Estimates of
methane oxidation have varied widely over the past decade. At the
present time, it appears that it is not the dominant source of global CO
as was the belief in the early 1970's. The most.recent estimates (1977
and 1978) indicate that methane may account for between 60 and 700
million metric tons per year, rather than the high of 5,000 million metric
tons estimated earlier. Another great uncertainty is the amount of CO
produced by hydrocarbon oxidation.• Estimates vary from 'a low of 50
million metric tons to a high of 1,300 million metric tons. Much more
research is required to reduce the uncertainty about the emissions from
this source. Estimates of the amount of CO emitted from oceans, plants,
forest fires, and rain are also uncertain, but are estimated to be much
less than emissions from methane and hydrocarbon oxidation. In metro-
politan areas, these sources are negligible. '
4.2.2 Man-Made Sources
Table 4-1 shows the man-made sources of CO in the United States in 1977,
in terms of estimated tons emitted by each source. Emissions from forest
wildfires are also included in the Table but account for a small amount
of the total given. Man-made sources account for about 103 million metric
tons of pollutants. About 83% of the total CO emissions are from trans-
portaton vehicles, inlcuidng both highway and nonhighway vehicles.
16
-------
Table 4-1
NATIONWIDE EMISSION ESTIMATES, 1977
(10 metric tons/year)
Source Category
Transportation
Highway vehicles
Non-highway vehicles
Stationary fuel combustion
Electric utilities
• - -Industrial
Residential, commercial & institutional
Industrial processes
Chemicals
Petroleum refining
Metals
Mineral products
Oil & gas production and marketing
Industrial organic solvent use
Other processes
Solid waste (burning)
Miscellaneous
Forest wildfires and managed burning
Agricultural burning
Coal refuse burning
Structural fires
Miscellaneous organic solvent use
Total
Emissions Trends Report, 1977. Research Triangle Park, North
Carolina: U.S. Environmental Protection Agency, December 1978'
(EPA-450/2-78-052).
CO
85.7
77.2
8.5
1.2
0.3
0.6
0.3
8.3
2.8
2.4
2.0
0
0 -
0
1.1
2.6
4.9
4.3
0.5
0.0
0.1
0
102.7
National
Percent
83.4%
75.2
8.3
1.2
0.3
0.6
0.3
8.1
2.7
2.3
1.9
0
0
0
1.1
2.5
4.8
4.2
0.5
0.0
0.1
0_
100.0
Air Qaulity and
17
-------
Nonhighway vehicles include aircraft, railraods, vessels, and miscellaneous
mobile engines such as farm equipment, industrial and construction machinery,
lawnmowers, and snowmobiles. The second largest category of CO emissions
come from industrial processes and account for about 8% of the total.
Included in this category, other than chemicals, petroleum refining, metals
and mineral products, are oil and gas production and marketing, which
includes crude oil and natural gas production, petroleum storage tanks
and transfer facilities, and gasoline service stations. Industrial
organic solvent use includes surface coating and degreasing of manufactured
products, printing and publishing. The subcategory "other processes11
includes emissions from pulp and paper, wood products, agricultural, rubber
and plastics, and textile industries. Forest fires and controlled
burning are estimated to emit 5% Of the total, followed in order of
magnitude by solid waste—about 2.6%, stationary fuel combustion—1.2%,
and miscellaneous sources—1%.
4.3 Ambient Concentrations and Total Emissions of CO
Current ambient CO concentrations (usually measured in parts per
3
million or mg/m ) and total emissions (usually measured in tons) and
their trends in the United States are important in determining the air
quality improvements required to meet the existing and any other proposed
standards. Current measurements of CO levels are reported quarterly to
EPA by State, local and federal agencies. There are about 450 CO monitor-
ing sites throughout U.S.A., of which 230 sites are operated by state
agencies and 220 by local agencies. A few sites are operated by federal
agencies also. Continuous measurements of ambient CO concentrations from
numerous cities throughout the United States are available from the U.S.
18
-------
Environmental Protection Agency's National Aerometric Data Bank (NADB)
in Standard Storage and Retrieval of Aerometric Data (SAROAD) reporting
format. A discussion of trends in ambient CO concentrations (measured in
ppm or mg/m and present CO concentrations'in various locations is
presented in sections 4.3.1 and 4.3.2 respectively. A discussion of
trends in nationwide CO emissions (measured in tons) is presented in
Section. 4.3.3. Projected ambient emissions of CO for several counties,
that were identified as- having the potential of being non-attainment
areas1, based on current CO concentrations, are presented in Section 4.3.4.
4.3.1 Trends in Ambient Concentrations of CO '
Ambient levels of carbon monoxide (CO) generally improved from 1972
to 1977. The nationwide data base over the years for CO has not been
extensive as those for TSP and S02; however, there was a 20% increase in
the number of sites with sufficient data for trends analysis, due to the
expansion of State and local monitoring programs. Data for CO trend
analyses were obtained from EPA's National Aerometric Data Bank. All
sites having at least 4,.QOO annual values during both 1972-74 and 1975-88
were designated as trend sites. For carbon monoxide, 243 sites met this
selection criterion, and more than 80% of these sites had at least 4 years
of data.
During the 1972-77 period, 80% of selected CO sites showed long-term
improvement and this trend was fairly consistent for all 10 EPA Regions.
The median rate of improvement for the 90th percentile of 8-hour values
was approximately 6% per year.
From 1976 to 1977, 70% of the 243 sites improved. Consistent with
this downward trend, almost one-third of these sites reported their lowest
values in 1977.
19
-------
Emission changes and meteorology can influence CO levels. An analysis
of CO levels in New Jersey from 1971 to 1977 revealed that the 1974
gasoline shortage with its changing driving habits had strong effects
during the winter of 1973-74, but the effects gradually diminished with
time. All sites showed significant improvement in ambient CO levels;
the results were valid even after accounting for the effects of meteorology.
The continuing improvement at the CO sites in this study were attributed
to both State and Federal CO emission reduction programs.
- • -In discussing the relationship between ambient CO levels and CO
emissions, it is important to clarify certain components involved in
estimating CO emissions. Two key factors are the vehicle miles travelled
(VMT) and the emission per VMT. In its simplest form, total CO emissions
may be viewed as merely the product of emissions per mile multiplied by
the number of miles travelled. Total CO emissions in 1976-77 were higher
than in 1974-75. During this time, the emissions per VMT actually decreased
due to emission controls but this was more than offset by an even greater
increase in VMT. Therefore, the net effect was an overall increase in
total CO emissions. Translating these emission components in terms of
ambient CO levels, it would be reasonable to expect improvement at down-
town locations that are saturated with traffic because the emissions per
mile reductions would outweigh any increase in VMT. On the other hand,
growth areas could record increases in ambient CO levels because increases
in VMT offset the reduction in emissions per VMT.
Carbon monoxide concentrations vary considerably from hour to hour,
day to day, season to season, and year to year. These variations are
20
-------
usually not random but follow fairly predictable temporal patterns
according to season of the year, day of the week, and hour of the day.
Hourly Patterns
The National Ambient Air Quality Standards (NAAQS) for CO are
currently based on a 1-hour and an 8-hour averaging time. Carbon monoxide
data are most frequently collected using time averages of 1-hour. Evaluat-
ing compliance with the 1-hour standard simply requires rank ordering
1-hour values for a year and comparing the second highest value with
3
1-hour standard, which is currently 40 mg/m (35ppm).
Ambient CO concentrations often follow regular hourly patterns of
variation which result from nearby vehicular traffic activity and meteoro-
logical factors affecting the dispersion of the CO. Two examples are
shown in Figures 4-2a and 4-2b which illustrate the "worst case day"
hourly CO curves based on 1977 data from CO monitoring sites in
* **
sites in Baltimore, Maryland , and Los Angeles, California , respectively.
(The "worse case day" is defined, herein as that day on which the annual
maximum 8-hr average CO concentration was observed.) While the exact
shape and magnitude of the hourly CO curve for these communities is
dependent to a large extent on meteorological factors, two peaks corres-
ponding with the morning and evening "rush hour" traffic are evident in
the figures. A third peak in CO concentration during the late evening/early
morning hours can also be noted in several of the figures.. This peak is
most likely influenced by late night calm meteorological conditions which
allow CO emissions to build up.
*
Maryland State Division of Air Quality Control. Carbon Monoxide data
supplied for the air monitoring site at 200 East Road Street, Baltimore,
MD, 1977.
*
Southern California Air Pollution Control District. Carbon Monoxide data
supplied by Station #76, Los Angeles, Ca, 1977.
21
-------
33
34
33
SO
20
26
24
ii i
Los Angeles
WORST CASE DAY
I I T I
10
8
O
O
12
10
B
a
4
1.1
A
/ V
_l_
•' vx I
/ ^ i
_i.
-o_ 1 .
10 Tl 12
12 1 23
4 5 A 7
AM
00
11 11 1
noon
2 3 4
567
PM
Figure 4-2a. Hourly variations of ambient CO
concentrations for Los Angeles, CA.
-------
—i 1 r
Baltimore
WORST CASE DAY
p.
30
20
26
22
to
in
;: 15
O
O
O
O
10
e
r>
II
.' i
/ i
/ i
/ i
12
2 3
fl
AM
0 W 11
12
noon
0
PM
10 Tl 12
Figure 4-2i>. Hourly variations of ambient CO
concentrations for Baltimore, MD.
-------
8-hour Patterns
As indicated earlier, the carbon monoxide data are generally collected
using time averages of 1-hour. ' Evaluating compliance with 8-hour standard
involves the calculation of 8-hour averages from the 1-hour data
set. These 8-hour averages are also rank-ordered to obtain the second
highest non overlapping value for comparison with the 8-hour standard,
3
which is currently 10 mg/m (9ppm). For enforcement purposes, only non
overlapping 8-hour intervals are counted as violations.
A typical example of average 8-hour values of CO concentrations calcu-
lated from 1-hour values, for Washington, D.C., is shown in Figure 4-3.
The 1-hour values are also shown as a convenient reference. In this ex-
ample, the value of 8-hour average shown at, say 8 AM, is the average of
1-hour values during the period midnight til 8 AM, and the value of
8-hour average shown at 9 AM is the average of 1-hour values during the
perod 1 AM til 9 AM and so on. There is some difference of opinion
among experts regarding the method of calculating the 8-hour averages
and regarding the selection of non overlapping 8-hour periods. However,
the purpose here is to present a typical pattern of the variation of CO con-
centrations measured in terms of 8-hour averages. It is seen that the
8-hour average curve is relatively smoother than the 1-hour curve and
generally lagging behind the 1-hour curve because of the averaging effects.
Seasonal Patterns
Ambient CO levels also follow seasonal patterns, which result primarily
from changes in meteorological factors.. Figures 4-4 and 4-5 show the
seasonal arithmetic mean, maximum 8-hr and maximum 1-hr CO concentrations
based on'1977 data for Baltimore, and Los Angeles, respectively. These
24
-------
6 8 10 12
8 10 12
MIDNIGHT
TUESDAY. 12-9-75-
FIGURE 4-3 8-HOUR AVERAGE CONCENTRATIONS OF AMBIENT CO FOR WASHINGTON, D.C. CAMP STATION
-------
42
4G
39 •
38
34
Baltimore
30
23
.29
24
U
o
U
H
4
t6*
12
X3
$-
*•
2
7 - hr. max.
8-hr. max.
Seasonal avg.
M
Winter
Spring
Summer
Fall
Figure 4-4w
Seasonal variations of ambient CO
concentrations for Baltimore, MD.
26
-------
Los Angeles
4D
33
36
34
32
30
23
26
24
22
20
18
16
14
12
10
8
6
4
2
*&§
££<
m
«-.- L; --r
m
/.
1-hr. max.
8-hr. max.
Seasons! avg.
'•'"* '-*2i
.%
Winter
Spring
Summer
Fall
Figure 4-5. Seasonal variations of ambient CO
concentrations for Los Anceles, CA.
27
-------
figures show that highest ambient CO concentrations are generally
observed during the winter and fall seasons.
In the winter and fall seasons, the tendency toward colder ambinet
temperatures results in increased production of CO emissions from cars,
in addition to CO emitted from other fuel burning sources. Also, the
more stable atmospheric conditions and low wind speeds which occur during
winter and fall result in decreased dispersion of CO emissions and contribute
a substantial part to the occurrence of high ground level CO concentrations.
Annual Patterns
Annual trends of CO concentrations are presented in Figures 4-6 and
4-7 for Baltimore, and Los Angeles. Each of the two cities shows a down-
ward trend in ambient CO concentrations.
For Baltimore County, monitoring data from 1976 shows a. factor of
3.4 decrease in annual maximum- 1-hr average CO concentrations and a similar
decrease (i.e., a factor of 3.1) in annual maximum 8-hr average CO concen-
trations compared with 1968 levels.
For Los Angeles, a 44 percent and 41 percent decrease in annual
maximum 1-hr and 8-hr average CO concentrations, respectively, has been
observed from 1968 to 1977.. A 50 percent decrease in the geometric mean
CO concentration has been observed from 1968 to 1975. Although a signifi-
cant reduction in ambient CO concentrations has been observed in Los
Angeles, the number of observed NAAQS violations still remains relatively
high. One-hundred thirty-two violations of the 8-hr standard were observed
in 1974 compared to 182 observed violations in 1968. For the 1-hr standard,
7 violations were observed in 1974 compared to 10 violations observed in
1968.
28
-------
68
78
Figure 4-6 Annual variations of ambient CO
concentrations for BaItimore, .MO.
29
-------
96
88
Cv.
1 I
i l I
55-
L
48
I 40(-
u
5 32
o
u 24
15
8
0
58
70
72 74
YEAR
76
78
Figure 4-7 Annual variations of ambient CO
concentrations for Los Angeles, CA.
30
-------
Air monitoring results have been presented only from selected sites
in several major U.S. cities. These sites are generally those located
close to major highways (i.e., microscale) and measure some of the highest
CO concentrations in these cities. Mesoscale CO sites in the same cities
would be expected to record much lower concentrations. More information
on CO levels measured in U.S.. cities is published annually in EPA's Air
Quality Trends Reports..
4.3.2 Existing Ambient Concentrations of CO
'in the Federal Register of March 3, 1978, the Office of Air Quality
Planning and Standards (OAQPS) set forth the attainment status of all
states in relation to the current national ambient air quality standards
•5
(NAAQS) i.e.. One hour second high standard of 35 ppm (40 mg/m ) and 8
hour second high standard of 9 ppm (10 mg/m ). A listing of the geographi-
cal areas that reported non-attainment of the NAAQS for CO in 1976-77 is
presented in Appendix A. A more comprehensive list of the counties that
potentially could be in violation of the existing and other proposed
standards was prepared by EPA. In doing this, the Agency:
1. Started, with the list as given in the Federal Register mentioned
above.
2. Added to this list those counties that showed design values that
are equal to or greater than 80% of the current standard values.
The design values were obtained from the Storage and Retrieval of
Aerometric Data (SAROAD) reporting system.
3. Checked the emission densities of those counties for which no
ambient concentration data exists and whose emission densities
were greater than a cutoff value of 100 tons/sq. mile/year
Added the names of the counties whose emission densities were
greater than the cutoff values to the list above.
31
-------
4. Included all those counties that are part of the same urban
area as those counties mentioned above.
The comprehensive list of the 272 counties selected in accordance
with the above guidelines is included in Appendix B. These 272 counties •
account for about 78% of national CO emissions. It is stressed that
this is the list of those counties that could be potentially in violation
of the present and proposed standards. A detailed analysis showed, as
will be discussed later in the report, that several of the counties were
not-and will not be in violation of any of the standards considered.
Table 4-2 showc a list of 19 counties that had a 1-hour design
value (i.e. , 1-hour second highest value) in violation of the current
1-hour standard in 1976/1977. The design values for each country are
also shown. Table 4-3 shows a list of those counties that in 1976/1977
had an 8-hour design value in violation of the current 8-hour standard.
The counties have been grouped in five categories. The logic of groupings
is self-explanatory from the Table. 'The total number of counties that
had a design value in violation of current 8-hour standard is about 164.
3
Of these counties, 72 had a design value in the range of 10-15 nig/m ,
63 had a design value in the range of 15-20 mg/m , 27 had a design value
3 3
in the range of 20-30 mg/m , 2 had a value in the range of 30-40 mg/m •
These results are shown also in the form of a histogram in Figure 4-8.
The sites where NAAQS violations occur tend to be those loacted
within urban areas near major streets.
32
-------
Table 4-2
LIST OF COUNTIES IN VIOLATION OF CURRENT
1-HOUR STANDARDS OF CO—40 mg/m3
(1976/1977)
County Name Design Value (mg/m )
Fairbanks, AK 47.10
Los Angeles, CA 54.00
Denver, CO 53.00
Fairfield, CT 50.60
Washington, D.C. 53.00
Ada, ID 45.30
Jefferson, KY 43.70
Montgomery, MD 40.20
Clark, NV 45.20
Morris, NJ 48.60
Bernalillo, NM 51.70
Bronx, NY 4502.00*
Kings, NY 56.30
New York, NY 43.70
Jefferson, OH 45.00
Oklahoma, OK 51.30
Northampton, PA 41.20
Arlington, VA 4467.90*
Alexandria, VA 5323.30*
Note: These values are in densities in tons/sq. mile/year.
Approximate equivalent design value is obtained by dividing
these numbers by 107.43. The conversion factor 107.43
was calculated by SRI International based on Holzworth
Model 3 with a correction due to Calder.9
Source: EPA's National Aerometric Data Bank (NADB) in Standard
Storage and Retrieval of Aerometric Data (SAROAD).
33
-------
Table 4-3
COUNTIES IN VIOLATION OF C'JRKENT 3-HOUR STANDARD FOR CO: 10 ng/a'
. 3
Jefferson, AL
Aianeda. CA
3ucto. CA
Merced, CA
Riverside, CA
San Oi«i;o, CA
San Francisco, CA
San Macao, CA
Stanislaus, CA
Tolo, CA
Arapahoe, CO
Jouldar, CO
£1 Paso, CO
Hew Haven, CT
B reward, FL
Dad«,.FL
Duval. DL
Hillsborough, DL
Orange , FL
Cook, IL
Madison. IL
Psorta, IL
Will, IL
Lake, IS
Urn, IA
Saavnee , XS
Vyandocta, XS
Aonaarundel, MD
3alii=ora, MO
»asMngtao, MS
Macomb, MX
Vayna, MI
•taooey, MX
Cascade. MX
Tail sws tone, MI
Clark, 57
Douglas, XV
3illsboraugh , MH
Atlantic, :.'J
Sergen, MJ
Merear, MJ
Middlesex, MJ
Moneouca, SJ
Donnana, :H
San Juan, MM
Irla, XT
Xiags, ST
Monroe, XT
Queans, MY
Scfaecectady, MT
Clark, OS
Cuyahoga, OH
tranklin, OH
Lucas, OH
Mahonig, OH
Oklahoma, OK
Tulsa, OK
Lane, OK
Marlon, OR
Lahigh, ?A
Luxerne. ?A
Richlind, SC
Tork, SC
Hamilton, TX
Shelby, TH
£1 ?aao, TX
Harris, TX
Chlctandon, VT
Fairfax, VA
itoanoke . VA
Hampcon, '/A
Pierce, WA
n»t. AZ
Kara, CA
Marion, CA
Sacrnaento, CA
San Jouquln, CA
Santa Barbara, CA
Solano, CA
Tulara, CA
>^daos , CO
Jefferson, CO
Veld, CO
Han ford, CT
Marion. LM
Polls, IA
Scott, LA
Douglas, :!0
Montgomery, MD
Prince George, MD
Jalciaora, MD
Cantral, MA.
Pioneer, MA
3obonnet, MA
iennacia, MK
Olascad, MH
SC. Louis, MH
Creeae, MO
St. Louis, MO
Douglas , :.~
Vashoe, :?V
COOS , :3
3urlington, MS
is3»xf :u
jlausascar, IIJ
Ocean, MJ
Paasaic, .'U
Somerset, MJ
Santa Fa, MH
Bronx, MT
Massau, MT
Mecklenburg. MC
Tamil ton. OH
Jefferson, OS
SumrrU, OH
Horthampton, ?A
Philadeipiua, PA
Providence, SI
Davidson, TX
£oox, TS
Davis, 7T
Salt Lake, 'JT
QCan, UT
Arlington, 7 A
Alaxaadria, '/A
Norfolk, VA
Richmond, 7A
King, WA
Milwaukee, WI
Anchorage, .\X
Fnlrbaiiks, AX
Marlcapa, AZ
Fresno, CA
Sunta Clara, CA
Denver, CO
Laciaer, CO
Washington , DC
Fulton, CA
Ada, 10
Jefferson, XT
Saglnatr, MI
St. Louis City, MO
Missoula, MT
Lancaster, ME
Canden, MJ
Hudson, :U
Morris, MJ
Union, J5I
3ernaJJ.Ho, MM
C-.avea, MM
Mew fork, MY
Montgoner/, OH
Mulcoaomah, OS
Allegheny , PA
Weber, VT
Spokane, WA
Los Angeles, CA
"airtiald, CT
72
27
Total: 154
34
-------
100
c
3
O
y
"S5-0
OJ
.fl
72
63
27
10
15
20
30
40
50
Range of Design Values for CO
(mg/m )
Figure 4-8.
Histogram of 8-Hour Design Values for CO and the
the Number of Counties Having Design Values in
Various Ranges. '
35
-------
4.3.3 Trends in Nationwide CO Emissions
Total nationwide CO emissions did not change substantially from
1970-1977 as can be seen from Table 4-4. Nationwide CO emissions from
various sources for the years 1970 through 1977 are summarized in Table
4-5. A graphical presentation of trends in the CO emissions is included
in Figure 4-9.
Table 4-4
SUMMARY OF TOTAL NATIONWIDE CO EMISSIONS, 1970-1977
Total Nationwide Emission
Year (10 metric tons/year)
1970 102.2
1971 102.5
1972 103.8
1973 103.8
1974 99.7
1975 96.9
1976 102.9
1977 102.7
Source: Office of Air Quality Planning and Standards, National Air
Quality Monitoring and Emissions Trend Report, 1977, Research
Triangle Park, North Carolina, U.S. Environmental Protection
Agency, December 1978 (EPA-450/2-78-052)..
An emission reduction resulting from less burning of solid wastes and
agricultural materials was offset by a 9% increase in emissions from
highway motor vehicles. As stated in section 3.3 the emissions per vehicle
mile travelled (VMT) actually decreased, due to emission controls, but,
was more than offset by an even greater increase in VMT. Therefore, the
net effect was an overall increase in total CO emissions.
36
-------
Table 4-5
NATIONWIDE CO EMISSIONS FROM VARIOUS SOURCES, 1970-1977
(106 METRIC TONS/YEAR)
Source Category
1970
1971
1972
1973
1974
1975
1976
1977
Transportation
Highway vehicles
Non-highway vehicles
Stationary fuel combustion
Electric utilities
Industrial
Residential, commercial & institutional
Industrial processes
Chemicals
Petroleum refining
Metals
Mineral products
Oil £< gas production and marketing
Industrial organic solvent use
Other processes
80.5
70.9
9.6
1.3
0.2
0.6
0.5
8.0
2.9
2.1
2.1
0
0
0
0.9
81.1
71.7
9.4
1.4
0.2
0.6
0.6
7.9
2.7
2.1
2.2
0
0
0
0.9
85.4
76.1
9.3
1.3
0.2
0.6
0.5
7.9
2.5
2.2
2.3
0
0
0
1.0
85.9
76.5
9.4
1.4
0.3
0.6
0.5
8.2
2.7
2.2
2.3
0
0
0
1.0
81.7
73.3
8.4
1.3
0.3
0.6
0.4
8.2
2.5
2.3
2.4
0
0
0
1.0
82.0
73.8
8.2
1.1
0.3
0.5
0.3
7.3
2.2
2.4
1.8
0
0
0
0.9
85.1
76.6
8.5
1.2
0.3
0.6
0.3
7.8
2.4
2.4
1.9
0
0
0
1.1
85.7
77.2
8.5
1.2
0.3
0.6
0.3
8.3
2.8
2.4
2.0
0
0
0
1.1
Solid waste 6.2 4.7 4.0 3.6 3.2 2.9 2.9 2.6
Mi scellaneous
Forest wildfires and managed burning
Agricultural burning
Coal refuse burning
StrucLui'al flx'us
Miscellaneous organic solvent use
Total 102.2 102.5 103.8 103.8 99.7 96.9 102.9 102.7
6.2
4.3
1.5
0.3
0.1
0
7.4
5.9
1.2
0.2
0.1
0
5.2
4.2
0.8
0.1
0.1
0
4.4
3.5
0.7
0.1
0.1
0
5.3
4.5
0.6
0.1
•0.1
0
3.6
3.0
0.5
0
0.1
0
5.9
5.3
0.5
0
0.1
0
4.9
4.3
0.5
0
0.1
0
Note: A zero indicates emissions of less than 50,000 metric tons per year.
Source: Office of Air Quality Planning and Standards, National Air Quality Monitoring and
Emissions Trend Report, 1977, Research Triangle Park, North Carolina, U.S. Environmental
Protection Agency, December 1978 (EPA-450/2-78-052).
-------
100
c/i '70
z
o
2 60
a
O
Z
O
UJ
50
<
£ 40
30
20
O TOTAL
-Q M08H.E SOURCES
-& INDUSTRIAL PROCESSES
-« MISCELLANEOUS
SOLID WASTE
STATIONARY SOURCES
77
FIGURE 4-9 TRENDS IN CO EMISSIONS (BASED ON TABLE 4-5)
38
-------
4
These CO emission trends differ from the 1976 report, because
of a change in the calculation of emission factors. The data in the
1976 report were based on vehicle emission factors given in reference
5. Emission estimates for 1970-1977 have been revised upward according
to the new data and calculation methodology.0' These new emission factors
were based on measured emission of in-use vehicles through model-year 1975
and on analytical estimates of emission for the 1976 and 1977 model-year
vehicles. Previous emission factors were based on measured vehicular
emissions only through calendar year 1972; projected emissions factors
.were used for subsequent years.
39
-------
4.3.4 Projected Ambient Emissions of CO in the Absence of Proposed
Action
Future ambient CO concentrations will clearly depend to a great
degree upon future amounts of CO emissions into the atmosphere and future
CO emission patterns. Since highest concentrations of CO generally result
from auto emissions, "the federal government has initiated a Motor Vehicle
Emission Control Program (FMVECP) to reduce the emissions of CO and hydro-
carbons from new vehicles over a period of years to the point where the
emissions from these vehicles will be only one tenth of the emissions from
1970'models. The final emission levels of 10% of- the 1970-1971 levels
are the legislative requirements of the Clean Air Act. However, even with
these impressive emission reductions in newer motor vehicles, the emissions
from all vehicles on the road do not drop fast enough in many ares to
meet the national air quality standards by established deadlines. The
main reason for this is that the total emissions are heavily influenced by
the number of miles driven by older, uncontrolled and moderately controlled
vehicles. That is,, even if all new vehicles produced zero emissions, the
rate of decrease in total emissions would still be- governed by the rate
of which the older, high emitting vehicles are retired from service. Of
course, after a time period long enough to turn over the vehicles popu-
lation the total emission would be strongly influenced by the particular
emission level of new vehicles. But due to growth in number of vehicles,
emissions are projected to increase after the mid-1980's. This projected
growth emphasizes the need for transportation controls to complement the
Federal Motor Vehicle Emission Control Program.
The other sources of CO emissions, i.e., point sources and area
40
-------
sources will also have to be considered while projecting the total
future CO emission concentrations.
In order to estimate the future emissions of CO associated with the
272 counties without any controls other than the FMVECP, two scenarios
were analyzed using a computer program developed by SRI International ,
namely:
• Scenario 1
- Line emissions assumed to decrease due to FMVECP according
*
to FMVECP reduction factors developed by EPA but to increase
due to county specific historic Vehicle Mile of Travel (VMT)
growth rates, i.e., the combined effect of nationally effective
FMVECP related reductions and county specific VMT growth
rates were considered.
- Area emissions assumed to increase in proportion to population.
- Point emissions assumed to increase in proportion to increase
in national manufacturing income.
- The. effectiveness of area, point and line emissions in pro-
ducing the CO concentration levels was assumed to be 100%,
0%, and 100%.
•; Scenario 2
- Line emissions change calculated as above except VMT growth
rate assumed to be uniformly equal to 1% annually.
- Area emissions assumed to increase at a level of 1% annually.
EPA has developed a methodology, that is available in the form of a
computer program—MOBILE 1 , to calculate several pollution related attri-
butes for specified conditions.
41
-------
- Point emissions assumed to increase as in Scenario 1.
- Effectiveness of area emissions was assumed to be 20%,
point emissions 0%, and line emissions 100%.
Scenario 1 is believed to present a relatively pessimistic scenario
wherein VMT growth rates are based on DMVT estimates by FHWA 10, and
area emissions are assumed to be proportional to population. Scenario 2
assumes a generally reduced VMT and area source emission growth rates due
to energy shortages predicted for future. The future emissions were cal-
culated for the years 1982, 1984, and 1987 for both scenarios. Summaries
of the analysis results are presented in Table 4-6.
Table 4-6 indicates that total emissions from the 272 counties studied
will decrease by about 28% in 1987 in scenario 1 and by about 3 9% in
scenario 2 due to FMVECP. Since the total national emissions of 1979
were not readily available, these were estimated by assuming that the
change in national emissions from 1976 to 1979 were in the same proportion
as the change in line emissions form 1976 to 1979. This assumption is
justifiable since about 85% of the national emissions consist of line
emissions. The reduction in line emissions from 1976 to 1979 was calcu-
lated to be about 5% in scenario 1 and 10.4% in scenario 2 using the
SRI International's program. Similarly, the national emissions in 1982,
1984, and 1987 were assumed to change in the same proportion as those for
the 272 counties.
Table 4-6 also indicates the number of counties that are likely to
*
be in violation of various proposed standards in 1982 ., 1984, and 1987
* 3
It was assumed that stricter standards, i.e., 1-hour 29 and 17 mg/m and
8-hour 8 mg/m^ will be implemented, if at all, no earlier than 1984. As
such, the number of counties in violation were calculated only for 1984
and 1987 for stricter standards.
42
-------
Talile 4-6
CUKKKHT AND rKO.IKCTT.I) TOTAL CO EMISSIONS AND NIIHIIKH OK NON ATTAINMENT COUNTIES
CONS IIH:K INC OMI.Y TUP: KFUKKAI. MI iron vrmu.ic EMISSION CONTKOI. CKOCKAM (iwi-:i:i')
1. Total emissions (10 cons/year
for 212 count11 us
2. Ksi iiiiau-d equivalent national
Clili liS UulS
. Number of cuur.trtos projected
to be In violation of various
standards.
A. 1-liour Standards
40 tig/I" second Itlch
40 iug/m .slalisLic.il
40 ni^/i:i daily maximum
29 uig/;o st.aistlt.il
29 mg/ia dally maximum
17 rag/iu st.lL l;,l i«:.il
17 m^/:.i daily uiixliuuii:
b. ti-liour standards
10 luj;/ ^' iu:i:und lil^ll
10 mg/W statistical
10 tug/tii daily m.-.xlrium
K mg/iu statistical
14 mg/iu daily maximum
ti nig/in statistical
b oi^/ai dully maxiuium
Sci;nario 1
• VMT Drouth county ^|>L>cltlc uiid lilutorlcul
• Area emission growth proportional to
populat lita
• Folnt emission prouort lunal to national
maiiuf ai: tur Injj income
• Effect Ivenuss of area, point & lint;
emissions in producing CO concntru-
llon - 100X, 100Z. 100X*
1979
78.4
% . 5
19
15
U
50
48
96
9U
164
165
162
98
95
176 -
17 J
1982
70.1
86.3
11
8
6
146
145
139
79
64
1984
63.5
78.2
3
2
3
18
18
74
67
118
119
109
51
38
159
151
1987
56.5
69.6
2
2
2
11
10
56
51
79
88
68
30
21
123
116
Sc<:»ai to 2
• VMT groutli rate IX
• Area emission growth rate 1Z
• I'olnt source emissions aa in scenario 1
• Effectiveness: Area - 20%; point - OZ;
line - 100**
1979
V3.7
94
19
15
14
50
48
96
98
164
165
162
98
95
176
173
1982
62.9
80.2
5
2
2
125
124
114
63
45
1984
55.5
70.8
0
0
0
9
8
61
55
83
89
77
24
14
130
119
1987
47.8
60.9
0
0
0
0
0
26
27
24
32
19
5
2
73
57
Source: Kesulis generated by SKI International'a computer prograw.
7
To iJcntify OHHU IUL; In violation, cite area, poiiU aaj line source emit;;,Imib wurt* multiplied respectively by fractions corresponding to the
ind 1 c.'itt.-d per cunt ages, and effective total emission values were calculated. Tlifcae effective total emission values of the count lea were used
to ideiit i I y 'the noii attainment count leu. The euiiaulou valuta given la the t'iruc two rows ore, however, without the appl Icatlou of the
effect I veaesii factors .
-------
under the two assumed scenarios. It is seen that inspite of the FMVECP,
there will still be several counties that will not meet the standards by
1987. In these counties additional CO control strategies, e.g., Inspec-
tion and Maintenance Program and Traffic Control Measures (TCM) will be
required if the standards are to be met by 1987.
A discussion of various control options for both mobile (line) and
stationary (point and area) sources is presented in the following chapter.
Primary impacts of judiciously selected control options are presented
in Chapter 6.
44
-------
REFERENCES CITED IN CHAPTER 4
1. Greiner Engineering Sciences, Inc., Fundamentals of Air Quality,
Washington, D.C. : Offices of Research and Development, Federal
Highway Administration, U.S. Department of Transportation.
2. Office of Air and Waste Management, National Air Quality and
Emissions Trands Report, 1977, Research Triangle Park, North
Carolina, U.S. Environmental Protection Agency, December 1977
(EPA-450/2-78-052).
3. ;/Office of Research and Development, Air Quality Criteria for Carbon
Monoxide, External Review Draft, Research Triangle Park, North
Carolina, U.S. Environmental Protection Agency, November 1978.
4. Office of Air and Waste Management, National Air Quality and
Emission's Trends Report 1976, Research Triangle Park, North
Carolina, U.S. Environmental Protection Agency, December 1977
(SPA-450/1-77-002).
5. Compilation of Air Pollutant Emission Factors, Research Triangle
Park, North Carolina, U.S. Environmental Protection Agency,
(AP-42, 3rd edition, including Supplement 1-7).
6. Office of Transportation and Land Use Policy, Mobile Source Emission
Factors, Washington, D.C., U.S. Environmental Protection Agency,
March 1978 (EPA-400/9-78-005).
7. SRI International, Computer Aided Methodologies to Conduct Regulatory
Impact Analysis of Ambient Air Quality Standards for Carbon Monoxide,
Menlo Park, California, September 1979 (SRI Project 6780).
8. Holtzworth, G. C. Mixing Heights, Wind Speeds, and Potential for
Urban Air Pollution Through the Contiuous Reneted States. U.S. En-
vironmental Protection Agency, CEPA. AP-101
9. Calder, K. L.. A Correlation to Holtzworth Model for Metereological
Potential for Urban Air Pollution. Atmospheric Environment, Vol. II
p. 761-764. 1977.
10. Program Management Division, FHWA, National Functional System Mileage
Travel Summary, U.S. Department of Transportation, Washington, D.C.,
1977.
45
-------
5 CARBON MONOXIDE CONTROL OPTIONS
5.1 Control Options Related to Mobile Sources
Nationwide emission estimates indicate that slightly over 80% of the
annual mass emissions of carbon monoxide from manmade sources are due to
mobile combustion sources. Control techniques for mobile sources are
thus the most effective and importatn methods for reducing carbon mono-
xide ambient air concentrations.
The discussion of control options for mobile sources can be divided
into three' major parts, namely:
1) Control of new mobile sources
2) Inspection and. Maintenance (I/M) Programs
3) Transportation Control Measures (TCM)
Each of these options is discussed below in some detail.
7 3
5.1.1 Control for New Mobile Sources '
Control of new mobile sources has received, significant development
efforts in recent years.. The driving force for this has been the imple-
mentation and enforcement of increasingly stringent CO exhaust emission
standards in accordance with the Clean Air Act Amendments of 1977. For
example, non-California Vehicle Exhaust Emission Standard for 1980
model light duty vehicles is 7.0 gms/mile and for 1981 and beyond, it is
3.4 gms/mile as compared to the current standard (1975-1979) of 15 gm/mile,
Similar stringent standards have been established for light duty trucks.
The California Vehicle Exhaust Emission Standard for 1975 and beyond is
9 gms/mile for light duty vehicles.
There are basically three approaches for controlling carbon monoxide
emissions from new mobile sources. The first and currently most
46
-------
effective method ±s treatment of engine exhaust gases for removal'of
the CO. The second method is to reduce formation of CO in- vehicle
engines by improving fuel/air mixture control. The third is to replace
conventional spark-ignited gasoline engines with alternative types
of engines which produce less CO, e.g., diesel engines. Table 5,1
contains a list of specific control devices and alternatives under each
of the three general methods and summarizes the status of development.
The CO emission reduction potential for the Exhaust Gas Treatment and
Fuel/Air Mixture Control are variable. The basic goal of these and
.other similar techniques is to comply with the Federal exhaust emmis-
sion standards. The percentage of new cars with reduced emissions will
gradually increase as the years pass by. The net effect is estimated
co be a 50-70% reduction in area wide CO emissions by 1987. Eventually,
the emissions from the mobile sources are expected to be reduced by at
least 90% taking the emission rates of 1970-1971 as the base values,
in accordance with the Clean Air Act.
Automobiles with stratified charge mechanism, gas turbine engines,
steam engines and electric cars emit very little carbon monoxide. How-
ever, these types of engines are either in a developmental stage or
are not yet economical to be used, as an alternative to the gasoline
automobile. As such 'their impact on CO emissions is not likely to be
significant for several years. Diesel engine automobiles are however
available in various models and deserve some discussion.
47
-------
Table 5-1
CARBON MONOXIDE CONTROL TECHNIQUES
FOR NEW MOBILE SOURCES
Type of Concrol
Status of Development
Fuel/Air Mixture Cor.:roL
Fuel/air feedback metering
Improved EGR*
Electronic ccncrol of spark
timing, EGR, cold enrich-
ment, and idle soeed
Extensive efforts currently underlay by
virtually every auto manufacturer on
feedback carburetion. and feedback fuel
injection.
Ford, GM, and Chrysler are all developing
electronic EGR systems.
GM has develooed and testing a system.
Exhaust Gas Treatment
3-way cacalyst
Oxidation catalyse
Thermal reactors
Altema tive £neinos
Stratified charge'
Diesel
Gas turbine
Steam engine
Electric
Currently available and receiving mosc
development work.
Currently available and receiving some
development work.
Currently used in many exhaust control
systems.
One variation is currently available
through Honda and others currently re-
ceiving extensive development work
(Ford and Texaco).
Numerous models available.
Currently undergoing extensive development
by s.everal major manufacturers.
Has been tested by several investigators.
Currently available via special production.
Exhaust gas recirculation.
Sources:
••Stern, Arthur C., ed. Air Pollution, Vol. 5, Air Quality Management, 3rd ed.
New York, Academic, 1977.
• Office of Air & Waste Management, Automobile Emission Control - The Development
Status. Trends, and Outlook as of December 1976, Research Triangle Park, N.C.,
U.S. Environmental Protection Agency, April 1977.
48
-------
Diesel engines emit CO in much smaller quantities than required
by the 1977 Clean Air Act Amendments (3.4 g/mi for 1981 models). In fact,
all diesel cars tested in 1978 by EPA emitted less CO than the emission
standard. The average CO emissions for the cars tested was 1.4 g/mi,'
4
compared to 5.4 g/mi for comparable gasoline engines.
Diesel cars also tend to be more fuel efficient than their gasoline counter-
parts, demonstrating approximately 50% better fuel/mileage.
;.' . The impact of diesel cars on CO levels will be determined by the
percentage of the vehicle fleet that changes from gasoline to diesel.
The increase .in the number of diesels on the road coupled with the decrease
in the amount of fuel burned will have a beneficial effect on CO levels.
Several market surveys have estimated future diesel car sales.
Most of the estimates are for the year 1985 and project that diesel sales
will be around 25% (America's Way, July 197'8). A National Highway Traffic
Safety Administration study (1977) projected diesel penetration to be:
5% in 1981; 10% in 1982; 15% in 1983; 20% in 1984; and 25% in 1985.6
Therefore, about 15% of new cars in the 1981-85 period will be diesel.
Given this projected penetration, the new car emission rate would also
be reduced. If the current 3.4 g/mi standard for 1981 and later model
year is maintained, the reduction would be about 8-9%. If this standard
is waived, and the 1980 model year standard of 7 g/mi is continued, the
reduction in the average new car emission rate would be about 11-12%.
49
-------
5.1.2 Inspection and Maintenance Programs
- Overview of I/M Programs
There are several types of inspection and maintenance programs and
several other variables which determine how most common types of inspection
and maintenance programs are thff-idle test program and the loaded mode test
program. In the idle test program emissions from the vehicle are measured
while the vehicle is running in neutral at idle. In the loaded mode test,
the emissions are measured while the vehicle is running in gear on a
treadmill-like device called a dynamometer. By operating the vehicle on
•a dynamometer the vehicle can be driven in several modes such as accelera-
tion, cruise, deceleration, and idle. A driving cycle made up of a series
of different driving mdoes more accurately represents actual driving
conditions than just the- idle mode. Thus, emission measurements taken
in the loaded mode test are more representative of actual driving emissions
than the measurements taken in the idle test. The choice of which in-
spection and maintenance program to implement, is a function of several
factors including the desired emission reduction, ownership and operation
of the inspection station, and the relationship of the inspection and
maintenance program with existing vehicle safety inspection programs.
In general, it is desirable to incorporate the inspection and
maintenance program into a vehicle safety inspection program if one exists.
If this is done, the manner in which the safety program is operated will
have an effect of the type of inspection and maintenance program chosen.
Loaded mode test inspection and maintenance programs could be incorporated
into a State owned safety program, but it would be difficult to incorporate
the loaded mode test program into a State licensed safety program because
50
-------
of the high cose of the testing equipment. Thus, in most cases idle tests
could be incorporated with State licensed safety inspections and loaded
mode tests with State owned safety inspection stations. If a loaded
mode test is required in a State with a State licensed safety inspection
program, it is most likely that a separate State operated emission test
program would have to be started.
" Effectiveness °f. Inspection and Maintenance Programs
Air quality data now available strongly suggests inspection and
maintenance programs result in improved air qualtiy. A recent study'of
seven years of carbon monoxide (CO) data in New Jersey has led the
researchers to conclude that; the I/M program, which began in 1974, and
increasingly stringent new car emission standards are together responsible
for a 28% decrease in ambient CO levels. The University of Wisconsin
statisticians found that the improvement in the air quality occurred
independent of year-to-year weather- patterns and at a time when traffic
•8.
volume was increasing.
The effectiveness of an. I/M program is determined by the standards
of "cut points" usually expressed, as stringency factors.. The cut point
is that level of emissions which distinguishes between those vehicles
requiring emission related maintenance and those not requiring maintenance.
Table 5-2. lists credits in emission reductions- that can be achieved
9
through I/M-programs. Technology I vehicles include those light-duty
vehicles subject to pre-1975 federal emission standard; Technology II
vehicles are those subject to 1975 and later model year emission standards.
51
-------
Table 5-2
CARBON MONOXIDE EMISSION REDUCTION
FROM-1/M PROGRAMS
Firet yc.ir
Vehicle typo
Seriuscacy
factor
0.10
0.20
' 0.30
' 0.40
0.50
Technology Tc<
I
3
8 '
13
19 '
22
Analog
II
3
20
28
33
37
Motorcycles
y aad ,
dti
lishe-ducy
trucks
3
3 8.
• 13 9.
19 10.
22. 12.
Subsequent years program
Additional benefits
icy Technology
iciifi I
5
3 7
2 9' .
5 a
0 7
credic.i
training
Technology
II
7
10
10
7
5
Stisicacua I
iusp-sccioa
0.2
0.2
0.2
0'.2
0.2
.. . Additior.il bea-ftcs
Ihsabcr of Insect ioaa
Addicts credit
n
Additive crsdiu CO (pcrcaac)
. Kechacic: criiaiss
Tcchnalo^y I Techno Logy II
Icapacciocs Iasp
-------
The percent reductions given in the table for mechanics training and
semi-annual inspections (as opposed to annual) are additive to the other
emission reductions. Refined I/M effectiveness factors as a function of
temperature and location (low altitude, high altitude, California) are
also calculable using MOBILE 1 program developed by EPA. A sample of I/M
effectiveness factors developed using MOBILE 1 program is shown in Table 5-3.
The effectiveness of. I/M programs in accomplishing fuel savings has been
under study by EPA's Inspection and Maintenance staff of the Emission
Q
Control Technology Division, Ann Arbor. It is believed that the fuel
'savings due to I/M programs will not be significant for the pre 1981
cars. However, beginning with model year 1981, passenger cars will
commonly utilize mini-computer controlled fuel and ignition systems.
Failures associated with these systems are likely to cause significant
fuel economy penalties. Based on some initial test data, it is believed
that the following fuel economy benefits are realizable through the
maintenance of 1981 and post 1981 cars:
I/M with 20% stringency - 7.5%
I/M with 30% stringency - 6%
I/M with 40% stringency - 4.5%
The percentage of 1981 and post 1981 cars in the year 1987 is estimated
to be about 78%, based on the study of historical trends.
5.1.3 Transportation Control Measures (TCM) Programs
- Overview of TCM Programs
Transportation Control Measures cover a wide range of transportation
related improvements or modifications, affecting either the supply or
53
-------
Table 5-3
PERCENTAGE REDUCTION ACCOMPLISHED IN MOBILE SOURCE EMISSIONS
IN TARGET YEAR 1987 WITH 30% STRINGENCY I/M USING MOBILE OUTPUT
(Without Mechanics Training)
Location
0)
3
U
0
a
3
«4
*
90
. T-t
a
e
a
'2
a
u
Ta-oeracurs
0
10
20
30
40
50
60
70
75
'- SO
0
10
20
30
40
50
60
70
75
80
0
10
20
30
40
50
60
70
75
80
I/M Initiation Year
-
1982
25.6
24.9
24.3
23.8
23.4
23.1
22.8
22.7
22.6
22.5
26.0
25.2
24.6
24.0
23.6
23.2
22.9
22.7
22.6
22.5
20.7
20.7
20.6
20.5
20.4
20.4
20.3
20.3
20.3
20.2
1983
22.9
22.2
21.7
21.2
20.8
20.5
20.3
20.1
' 20.0
19.9
23.2
22.5
21.9
21.4
21.0
20.6
20.3
20.1
20.0
19.9
18.4
13.3
18.2
" ' 18,1
13.1
13.0
13.0
17.9
17.9
17.9
1984
19.3
13.7
13.2
17.3
17.5
17.1
16.9
15.3
16.7
16.6
19.7
19.1
18.5
13.0
17.6
17.3
17.0
16.9
16.3
16.7
15.0
15.0
14.9
14.9
14.3
14.3
.14.7
14.7
14.7
14.6
Source: Results calculated by using MOBILE 1 program.
54
-------
demand for transportation service. The TCM programs can be broadly
divided into two groups:
1. Programs to reduce areawide CO emissions.
2. Programs to reduce local CO emissions.
A sufficiently detailed list of various transportation control measures
is presented in Table 5-4.
- Effectiveness of TCM Programs '
Based on the study of readily available literature and discussions
with-several transit authority officials, it is concluded that TCM
•programs can accomplish a maximum of about 5% reduction in CO emissions
on an area wide basis. About 3% of the reduction is realizeable through
a combination of such programs as signal timing optimization, freeway
surveillance and computerized control of street flow. The rest, 2%, is
realized through a combination of such programs as ride sharing,
work rescheduling, transit improvements, etc. Higher emission reductions,
e.g., 10-15%, result in specific hot spots by appropriately selected local
TCM control strategies during peak periods. However, the selection of
a suitable local TCM strategy requires the detailed knowledge of the
street network geometry, traffic volumes and the environments. In
this connection it is to be noted that almost all of the TCM programs
are primarily implemented to improve the transit'operations and con-
serve energy. The reductions in CO and other pollutants are usually
cited as additional advantages. However, for the sake of consistency
and completeness^a brief discussion of several TCM programs is
presented below.
55
-------
Table 5- 4
EXAMPLE OF TCM PROGRAMS
1. Programs to Reduce Area-wide CO Emissions
- Improved public transit.
- Area-wide ride sharing program.
- Provisions for employer participation in programs to encourage
car pooling, van pooling, transit, bicycling and walking.
- Distribute traffic peaks by implementing staggered work
hours and flextime.
Reduction in number of commute trips by encouraging
four day work weeks.
Institute road user charges, tolls, parking charges"at
employer lots or deferential rates to discourage single
occupancy automobile andlight pick-up truck use.
- Limit portions of roads or certain sections of the metro-
politan area for bicycle or pedestrian use,, both as to
time and place.
Construct new parking facilities and operate existing
parking facilities as park and ride lots and fringe parking.
- Long-range transit improvements involving new transportation
policies and transportation facilities or major changes in
existing facilities.
2. Programs to Reduce Local CO Emissions
-• Improve signalized intersections..
Establish exclusive bus and car pool lanes.
- Implement ramp metering at suitable locations.
- Control on-street parking.
- Limit portions of roads.or certain sections of the metropolitan
areas to the use of common carriers, both as to time and place.
- Designate certain streets as one way streets.
- Relocate certain stop signals and signs.
- Divert through traffic to bypass roads.
56
-------
• Ride Sharing - Ride sharing or car pooling programs offer the
potential for reducing the number of vehicles on the streets
and highways thereby reducing the vehicle miles travelled which
result in the reduction of CO emission's. The three most success-
ful demonstration programs in Portland, San Antonio and Sacramen-
to exhibited VMT reductions of 1%, 0.8%, and 0.7% respectively.
Assuming a corresponding reduction in CO, it can be expected that
the ride sharing programs have a potential of reducing the CO
emissions by about 0.8% on an area wide basis.
• Work Rescheduling - The main thrust of work rescheduling strategy
is to reduce conjestion within and to and from major employ-
ment centers, particularly "CBD's", by spreading out the peak.
There are two basic alternative forms of variable work hours:
1) Staggered hours in which changes in fixed schedules of
starting and quitting times are implemented, and 2) Flexitime
in which employees have freedom to adjust their working hours,
within limits..
Staggered and flexible work hour programs have been implemented
by six Federal departments in Washington, D.C. and by some
private firms in many U.S. cities. The most ambitious program
was implemented in New York City by 400 Manhattan firms affect-
ing 220,000 employees. Based on the study of the effects of
work rescheduling programs in various cities, it is antici-
pated that potentially an area wide reduction in travel time of
about 0.4% can be expected due to work reschedule programs.
57
-------
Assuming a corresponding reduction in CO, it can be assumed
that work rescheduling .programs have a potential of reducing
the area wide CO emissions by about 0.4%.
• Public Transit Improvements
This program includes a number of actions that can be taken
collectively or individually to improve transit operations.
- Transit route modifications
- Transit schedule modifications
- Transfer improvements
- Express bus service
- Park-ride facilities, and
- Simplified fare collection
In certain cases where comprehensive improvements were imple-
mented, e.g., increased express bus service and a busway on the
San Bernardino Freeway in Los Angeles, increased peak bus
fleet in Miami,. Florida, greatly expanded service in Eugene,
Oregon, the areawide VKT were reduced by 0.22% to 0.24%.
With the recent indications of gasoline shortage, it is to be
expected that an increased number of people will be motivated
to use public transit if it offered a reasonably attractive
alternative. Therefore, it is expected that improvement in
public transit systems can have an equivalent effect of reducing
area wide CO emissions by 0.5 - 1%.
58
-------
• Signal Timing Optimization
If a CBD traffic signal network is not set for progression,
the potential improvement in travel speed with a well-
timed system and selected other traffic improvements is as
as high as 40%, In many cases, however, some progression
already exists and the potential for improvement is
significantly less. Most probably the potential of area
wide CO reduction associated with signal timing optimizations
is about 1.5%.
• Computerized Control of Street Flow
Traffic actuated signals tied to computerized signal
systems have been installed in or planned over 115 cities
• in U.S.A.. San Jose, Wichita Falls,. Baltimore, Washington
D.C. and Charleston are some of these cities. The area
wide effect of computerized control of traffic flow is to
increase overall travel speed. It is to be expected
that the effect of improved traffic flow due to computerized
signals on areawide CO is a potential reduction of about 1%.
•• Freeway Surveillance and Control
Signalizing freeway ramp intersections to control or meter
the entry of vehicles onto the freeway systems is an increas-
ingly popular and successful way of improving the use of
existing facilities, increasing overall flow speeds, and
decreasing total travel time. Many cities have installed
ramp metering equipment, e.g., New York City, Los Angeles,
59
-------
Atlanta, Detroit, Dallas, etc. The effectiveness of free-
way control techniques on areawide CI reduction is esti-
mated to be less than 1%.
• Street Parking Restrictions
Removing on-street parking helps to improve vehicular flow
by increasing street capacity. Furthermore, by discouraging
the use of automobiles in crowded central business districts
(CBD), the institution of on-street parking constitutes an
..-. • important element of TCM programs. The estimated potential
CO reduction due to parking restrictions is about 0.2%.
5.2 Control Options Related to Stationary Sources
5.2.1 Traditional Control Options
Control of CO emissions from stationary sources is achieved by
reducing the amount of CO created, by limiting the amount released, or
by destroying the CO (i.e.,. burning it to convert it to CO-) , or by a
combination of these approaches. CO is emitted as a byproduct of both
combustion and noncombustion processes.
In combustion processes, CO emissions are controlled by establishing
and maintaining proper combustion conditions. The basic variables that
affect CO production are oxygen concentration (air/fuel ratio), flame
1 2
temperature, residence time (at high temperature), and turbulence.
The objective of combustor design is to arrive at the least
practical design that provides a near stoichiometric air/fuel ratio, high
flame temperature, sufficient residence time, and high turbulence. The
same design objective applies to all combustion processes, including home
furnaces, industrial boilers, and utility power plant boilers.
60
-------
CO is created in a variety of industrial processes. In some cases,
especially in petroleum refining and iron and steel manufacturing, operating
procedures or equipment adopted for production efficiency or to control
other pollutants (e.g., particulates, H_S) also limit releases of CO. _
CO that escapes, or in the case of byproduct CO in other industrial
processes, is typically controlled by supplemental equipment applied to waste
13
gas streams . This equipment includes incinerators, flares or
plume burners, and CO boilers.
.. • Incineration is the most appropriate and efficient technique for
controlling CO emissions from most, industrial process sources .
Two basic incinerator (or afterburner) designs)—thermal and catalytic—
are currently used. Each has advantages in certain applications, but both
have been used extensively. Thermal incinerators can be applied to virtually
all CO-containing waste gases that are below the lower explosive (i.e.,
combustion) limit. Heat recovery is an option in some cases. Gas streams
that can support combustion would be flared, or sent to a boiler or process
furnace for heat recovery rather than incinerated. Application of catalytic
incinerators is somewhat limited by the possibility of catalyst poisons
in the waste gas.
Flares and plume burners are devices that thermally incinerate waste
gases such as carbon monoxide, with no recovery of heat.. The
primary distinction between a flare and a plume burner is the amount of
supplemental fuel necessary to maintain combustion: A flare requires sup-
plemental fuel, while a plume burner is compeltely self-supporting. In
the past flares and plume burners have been most commonly used as safety
devices to incinerate waste gases from petroleum refining and petrochemical
61
-------
manufacturing operations. More recently, other industries, such as carbon
black manufacturing, have also been using flares and plume burners to dispose
of waste gases.
Control of CO emissions by oxidation in a boiler is generally employed
13
only when the waste gas has a relatively high heating valve.
The use of CO boilers is limited to those situations in which large quantities
of supplemental fuel are not required, the waste gas is free of fouling con-
stituents, and the waste gas rsource can operate independently-of the CO
boiler. CO boilers have been applied to petroleum refining fluid catalytic
cracker regenerators, fluid cokers, and carbon black plants.
5.2.2 Nontraditional Control Methods
In addition to the methods discussed in the previous- section, a
number of other 'methods have been proposed to control the ambient con-
centrations of air pollutants. These methods are nontraditional because
they differ from the direct regulation of pollutants from single sources
or source types, which has been the usual approach to air pollution con-
trol to date. None of these methods was considered as part of the con-
trol strategies analyzed in this EIS, but some of the methods have been
implemented by states or air pollution control districts, or have been
approved by EPA. Nontraditional control methods include emission off-
sets, indirect source reviews, use of open space, emission density zon-
ing, transferable emission rights, and emission fees.
Emission Offsets
- Emission offsets were first proposed by EPA in an Interpretive
Ruling in December 1976 as one means to accommodate economic growth- while
62
-------
pursuing clean air goals (41 FR 55524). The principle of offsets is
that, for a new source to locate in a nonattainment area, emissions from
existing sources must be reduced more than the expected level of emis-
sions from the new source. The intent is to make progress toward the
NAAQSs.
In the Clean Air Act Amendments of 1977 (42 U.S.C. 7401 et seq.)
Congress made the EPA offset policy, with some modifications, effective
until July 1, 1979. After that date a state may use an offset approach
if it is part of its revised State Implementation Plan (SIP). To comply
with the legislation, EPA revised its interpretive ruling in January
1979 (44 FR 3274). Major new or modified sources proposing to locate
in a nonattainment area after July 1, 1979 will have to apply for a per-
mit. The- conditions of receiving the permit include a requirement that
the proposed new source use pollution control technology that will res-
ult .in the lowest, achievable emission rate (LAER) , and one that the
applicable SIP is being carried out. Among the provisions that the SIP
must have are a plan to assure reasonable progress toward meeting the
deadlines for achieving the NAAQSs and an allowance for new growth. These
two provisions are to be linked to show that reductions of emissions
from existing sources will more than offset the emissions from new and
modified sources. Thus, taken together, these two provisions will allow
each state to apply an offset policy for the nonattainment area as a
14
whole as well as one tied to specific new sources .
As noted in Section 4, CO is produced primarily by motor veh-
icles. Therefore, the opportunities for offsets are quite limited, and
almost certainly will be available only through an areawide offset stra-
tegy.
53
-------
Indirect Source Review
Indirect sources are facilities such as major highways and
airports that lead to generation of large amounts of mobile source
emissions. The goal of indirect source review is to reduce emissions by
minimizing vehicle miles traveled (VMT) and reducing engine operating
time. This may be done by such measures as improving traffic flows
through design and spacing of entrances and exits, eliminating left-turn
20
movements, staggering operating hours, and improving mass transit.
• •' • Indirect source review has been a highly controversial issue.
'In 1973, states were required by court order to revise their implemen-
tation plans to include preconstruction review of indirect sources, and
in 1974, EPA issued final regulations. However, enforcement of the reg-
ulations was repeatedly deferred because of widespread disapproval of
the strategy and congressional interest in the issue. Finally,
in the Clean Air Act Amendments of 1977, Congress restricted EPA's
authority to require review of indirect sources to only "federally
assisted highways, airports, and other major federally assisted
indirect sources and federally owned or operated indirect sources." A
state may include in its implementation plan the requirement that all
new indirect sources be reviewed prior to construction to determine if
the source will prevent the attainment or maintenance of an ambient air
quality standard. EPA may approve indirect source review when proposed
by a state but may not require indirect source review except for pro-
jects that have Federal participation.
64
-------
Open Space Utilization
This control method involves locating emission sources or cre-
ating and maintaining open space to use the natural ability of soils and
vegetation to remove pollutants from the air. A recent report docu-
mented that open space (e.g., bare soil, vegetation, water can trap air
pollutants through the natural processes of adsorption, absorption,
impingement, and deposition.
In particular, soil and (to a lesser degree) vegetation, are
effective removers of CO. Laboratory experiments have shown that soil
2
can be a significant sink capable of removing CO at about 0.02 g/m /hr.
Vegetation removal rates are about an order of magnitude lower.
The principle of open space utilization is to reduce pollutant
exposure by siting emission sources near open space or by creating open
space adjacent to sources. In addition to their removal ability, open
space and buffer strips can be used to separate sources from receptors.
Emission Density Zoning
This method -is designed to limit air pollution by placing upper
limits on emissions from a geographic area, rather than on emissions
from individual sources. In other words, the maximum emission rate is
based on location, area, and land use, as well as ambient air quality
standards.
EDZ is based on the premises that (1) the regional air mass
has a certa-in assimilative capacity which depends on local meteorology
and the nature and concentrations of pollutants, and (2) by dispersing
65
-------
•pollutant sources, air pollution concentrations can more effectively
be kept below ambient standards.
EDZ is very similar to traditional land use zoning. It may be
thought of as an air pollution control regulation that is superimposed
20
on an existing land use zoning ordinance. That is, EDZ adds an
additional constraint on development by specifying the maximum allowable
emissions of a given pollutant per unit of time and unit of area. Under
EDZ, unusually large sources may have to buy up adjacent land or emission
rights from other land owners (see next section).
Because EDZ is tied to land and land use, it cannot be used
to regulate motor vehicles, which are the source of nearly all CO emis-
sions. Thus, while an allowance can be made for mobile emissions in
the calculation of emission density limits, vehicles would fall outside
the scope of this control method. Including mobile sources would require
a broader EDZ concept of greater complexity and possibly a change in the
special regulatory attention given to motor vehicles.
Transferable Emission Rights
Transferable emission rights may be used as a mechanism for
the exchange of allowable pollutant emissions among sources (EPA, 1978a;
Loehman, 1979). The mechanism may be part of EDZ or may be embodied in
a system of marketable permits for individual sources. For example, a
land owner may purchase "air rights" for a prescribed amount of emis-
sions from another landowner, who then is restricted in the amount of
emissions permitted from his land. Emission rights generally will be
more expensive where there is a high demand from many sources than .in
66
-------
areas where there are fewer sources of comparable size. More expensive
emission rights would be justified in order to buy the remaining rights.
'This control method suffers the same deficiency as EDZ with respect to
regulating the primary sources of CO: motor vehicles are not tied
to particular parcels of land.
Emission Fees
In an emission fee system, a charge is assessed for each unit
of pollutant emitted. Those sources whose abatement costs are less than
the'fee would chose to limit their pollution, whereas those whose costs
are greater would chose to pollute. All pollution sources would choose
the level of control that equates their marginal cost of control with
the fee. The fee can be set to achieve any desired level of control,
18
and thus of ambient air quality.
In principle, this control method could be applied to individual
mobile sources based on information from EPA's current new model emis-
sions testing program. The fee levied would be added to other vehicle
costs and the buyer would consider- the cost of polluting as well as of .
other features against the value he or she would expect to derive from
the vehicle. A fee-based control method would have to supercede or be
integrated with the present standards approach to regulating mobile
sources.
67
-------
5.2.3 Effectiveness of Stationary Source Control Options
Emissions from existing space heating units can be reduced by
proper operation and maintenance of the equipment. This attention to
good practice ensures that the best possible combustion conditions are
achieved. Potentially extremely high CO concentrations in the flue gas
can be dramatically reduced by proper adjustment of the air/fuel ratio
(HEW, 1970). Emissions may also be reduced by replacing the burner or
the entire furnace. Burner maintenance or replacement typically has a
20
beneficial impact on all pollutant emissions except NO .
X
New furnaces in which all combustion parameters can be controlled are
the most promising approach to reducing all pollutants, especially NO .
Unfortunately, replacement of old furnaces is prohibitively expensive.
Good initial design and proper operation and maintenance are the
only available CO control techniques for industrial and utility boilers.
13 19-
Th ere are no add-on devices. '
Control of CO emitted in industrial operations can be achieved
with thermal or catalytic incinerators, CO boilers, or flares or plume
burners.
The efficiency with which CO in dilute quantities in a. waste stream
can be controlled by thermal incineration depends primarily on residence
time, • temperature, and degree of mixing within the incinerator.
Proper design can result in. CO removal efficiencies consistently exceeding
90%. Higher efficiencies can be achieved by designing for longer residence
times and higher temperatures at the expense of higher capital and operating
costs.
68
-------
CO control by catalytic incineration depends primarily on the
13
operating temperature and catalyst bed volume . With proper •
design and operation, CO removal efficiencies greater than 90% can be
consistently achieved. Achieving higher efficiencies requires greater
capital investment, primarily for increasing catalyst bed volume. To
ensure good CO removal over a period of time, the design must compensate
x
for catalyst deactivation.
Control efficiencies of a properly operated CO boiler are on the
order of 99%. The effectiveness of flares or plume burners is uncertain
because of the lack of information.
5.2.4 Resource Utilization
CO control techniques that involve modification to the combustion
process, whether in residential furnaces or industrial and utility boilers,
do not require additional resources. Replacement of residential burners
or furnaces would, of course, require additional materials and energy to
manufacture.
Resource requirements for the various techniques for controlling
industrial CO emissions vary greatly.. They may include
supplemental fuel to ensure stable combustion in thermal incinerators,
CO boilers, and flares or plume burners. Some of this cost may be balanced
by the gain from heat recovery, if it is practical. Catalytic incinerators
require platinum or platinum-family catalyst materials. All CO control
devices require resources for construction and operation, but the amount
depends in each case on the. characteristics and size of the production
unit and the properties of the waste gas stream.
69
-------
5.3 Prevention of Significant Deterioration (PSD)
The concept of PSD emerged from successful litigation over a phrase
in the original Clean Air Act.' Its purpose is to prevent significant
deterioration of air quality in areas where it is already cleaner than
the ambient standards. The 1977 Amendments specified allowable increases
(increments) in concentration only for sulfur dioxide and particulate
matter. The law directs EPA to issue PSD regulations for the other
14
criteria pollutants, including CO, by August 1979.
• The current PSD regulations apply to large, new or modified stationary
sources in 28 specified industrial categories located or seeking to locate
in clean air areas. Most major industrial sources of CO fall within these
categories. A similar limitation in applicability to the most significant
stationary emitters can be expected when the PSD regulations for CO are
issued.
Mobile sources are the most important component of ambient CO concen-
tration. However, EPA has not yet issued PSD regulations for CO, and
it is not yet known whether mobile sources will be regulated or if so, in
what manner. In the absence of direct PSD regulation, their influence
will probably be similar to that in the SO, and TSP cases, for-which
emissions growth from general commercial, residential, industrial, and
other sources must be considered when determining the remaining available
PSD increment. On the other hand, states will have the freedom to
regulate mobile CO sources directly through review of facilities that
attract mobile sources.
The PSD regulations were issued by EPA, and are being used by EPA
to review projects subject to the regulations until each state adopts its
70
-------
own PSD regulations as part of its SIP. States may adopt regulations
different from those of EPA as long as they are not inconsistent with
EPA's. Therefore, for determining which projects are to be reviewed,
states may choose to lower the emissions threshold below the 100-ton
level established by EPA. They may also make all stationary sources
exceeding the threshold subject to review, thereby not limiting the
review only to those sources in the 28 industrial categories specified
by EPA.
PSD rules for CO will not have a bearing on the ambient CO standard
in the near future. When issued, the rules will apply only in clear air
areas. In these areas, the ambient CO concentration will be allowed to
increase an amount equal to the specified increment, but not to exceed
the ambient standard. Taking the increment as a measure of significance,
ambient air quality will not be permitted to deteriorate significantly
as new CO sources locate in the clean air area. In situations where the
full increment cannot be used up without violating the ambient standard,
a lower standard would allow less degradation of the air. At some point,
new sources of CO may find it too expensive or even impossible to locate
in a given clean air area. These sources would then turn to other clean
air areas or to nonattainment areas.
71
-------
REFERENCES CITED IN CHAPTER 5
1. Office of Air and Waste Management, National Air Quality and Emission
Trends Report - 1976, Research Triangle Park, North Carolina, U.S.
Environmental Protection Agency, December 1977 (EPA-450/1-77-002).
2. Stern, Arthur C., ed., Air Pollution, Vol. 5, Air Quality Management,
3rd edition, New York, Academa, 1977.
3. Office of Air and Waste Management, Automobile Emission Control - The
Development Status, Trends, and Outlook as of December 1976, Research
. .Triangle Park, North Carolina, U.S. Environmental Protection Agency,
April 1977.
4. Goen, Richard L., and Mary E. Ivory, Diesel Cars in the United States,
• Menlo Park, California, SRI International, Report for U.S. Department
of Energy, 1978.
5. EPA/DOE, Gas Mileage Guide, 1976, 1977, 1988.
6. National Highway Traffic Safety Administration, 1977, Rule Making
Support Paper Concerning the 1981-1984 Passenger Auto Average Fuel
Economy Standards, Washington, D.C. 1977.
7. Emission Standards and Engineering Division, Control Techniques for
Carbon Monoxide Emissions, Chapter 3, Durham, North Carolina, U.S.
Environmental Protection Agency, June 1979 (EPA 450-3-79/116).
8. Inspection and Maintenance Staff, Emission Control Technology Division,
Questions and Answers Concerning the Technical Details of Inspection
and Maintenance, Ann Arbor, Michigan, U.S. Environmental Protection
Agency, April 1979.
9. Kincannon, Benjamin F., and Alan H. Castaline, Information Documents
on Automobile Emission's Inspection and Maintenance Programs, Final
Report, Washington, D.C., U.S. Environmental Protection Agency,
1978 (EPA 68-01-4458).
10. Alan M. Voorhees, Inc., Transportation System Management, An Assess-
ment of Impacts, McLean, Virginia, U.S. Department of Transportation,
November 1978.
!!• SRI International, Draft Report, Assessment of Mobile Source Control
Strategy Cost Effectiveness, Menlo Park, California, June 1979
(SRI project 6780), EPA Contract 68-02-2835.
72
-------
12. Office of Research and Development, Environmental Criteria and
Assessment Office, Air Quality Criteria for Carbon Monoxide,
External Review Draft, Research Triange Park, North Carolina,
U.S. Environmental Protection Agency, 1978.
13. Emission Standards and Engineering Division, Control Techniques for
Carbon Monoxide Emissions, Chapter 6, Durham, North Carolina, U.S.
Environmental Protection Agency, June 1979 (EPA 450-3-79/006).
14. Raffle, Bradley I., The New Clean Air Act—Getting Clean and Staying
Clean, Environmental Reporter Monograph No. 26, May 19, 1978.
15. CEQ, Environmental Quality, The Sixth Annual Report of the Council
on Environmental Quality, 1975.
16. Office of Air Quality Planning and Standards, Open Space as an Air
Resource Management Measure, Vol. I Sink Factors, Vol. II Design
' Criteria, Vol. Ill Demonstration Plan, Research Triangle Park,
North Carolina, U.S. Environmental Protection Agency, 1976 (EPA-'
450/3-76-028).
17. Office of Air Quality Planning and Standards, Emission Density Zoning
Guidebook, A Technical Guide to Maintaining Air Quality Standards
Through Land-Use-Based Emission Limits, Research Triangle Park,
North Carolina, U.S. Environmental Protection Agency, 1978 (EPA
450/3-78-048).
18. Dick, Danial T., Working paper on Emission Charges or Taxes, Menlo
Park, .California, SRI International, 1979.
19. Letter from Donald J. Henz to Ms. Susan E. Schechter of Energy and
Environmental Analysis, Inc., PEDCO Environment, Inc. 1979.
73
-------
6. PRIMARY ENVIRONMENTAL IMPACTS OF THE PROPOSED ACTIONS
6.1 General
Primary impacts of a proposed action are those that can be directly
attributable to the proposed action, i.e., setting and enforcing an am-
bient air quality standard for Carbon Monoxide. Since fourteen alternative
standards for CO are currently being considered, the primary impacts of
setting and enforcing each of these fourteen standards has to be analyzed
separately.
The primary impacts in each case will be: . •'
1. A decrease in the quantity of CO emitted to the atmosphere.
2. A decrease in the number of counties exposed to high ambient
levels of CO.
3. A saving in gasoline used in automobiles.
However, the extent of reduction in CO emissions and concentrations,
saving in gasoline and reduction in number of counties exposed to high
ambient levels of CO will depend upon the selected standards and control
strategies implemented to meet the standards.
The projected. CO emissions for the years 1982, 1984, and 1987 con-
sidering the effects of only the Federal Motor Vehicle Emission Control
Programs were presented in Table 4-6. Also indicated in that table were
the number of counties that were projected, to be in violation-'in 1982,
1984 and 1987 of various standards if only FMVECP is considered. In
this chapter the primary impacts of implementing Inspection and Main-
tenance (I/M) programs and Traffic Control Measures (TCM) is presented
in some detail. The analysis was conducted using a computer program
1 2
developed by SRI International ' in accordance with the guidelines
74
-------
provided by EPA. A summary of the basic assumptions and procedures used
in the program.is included in Appendix C for convenience.
6.2 Air Quality
Direct impacts of setting and enforcing various CO standards on air
quality will be a.reduction in the tonnage of CO emitted annually to the
atmosphere and a reduction in the number of non-attainment counties.
Procedures to calculate the needed reductions in- the years 1982, 1984,
and 1987 and the criteria to select a set of control strategies to
accomplish CO reductions is explained in Appendix C. Using the proce-
dures explained in Appendix C, the emission reductions required in each
of the non-attainment counties were calculated and summed to determine
the total reductions which would be required to attain and maintain the
alternative standards. Effects of reasonably realistic Inspection and
Maintenance programs and Transportation Control measures were then tested
for various urban areas and counties as explained in Appendix C to
accomplish reductions in CO emissions. Control strategies for area
sources'and point sources were not considered, and it was assumed that
the burden of reducing CO emissions will be on mobile sources. A summary
of the results similar in format to Table. 4-6 is presented in Table 6-1.
This table includes certain useful information from Table 4-2 for easy
comparison and is organized around the same two scenarios that were con-
sidered in Table 6-1. As indicated, it was assumed that the maximum
allowable level of I/M stringency is 30% and that a maximum of 5% reduc-
tion in CO emissions is realizable through TCM strategies. The improve-
ment in CO reductions by using higher stringency levels, e.g., 40% was
found to be disproportionally small compared to the increased repair and
75
-------
Stamlurdu
A. One-Hour Standarda
1,0 mi;/"' Second lilgll
40 u.i;/ai Statistical
40 ui);/ot^ Ually maximum
'it u.K/013 Slill6tli.il
29 iu>;/in - Ditlly mil x 1 amu
1?
Slat lutlcal
I? m>;/iu Oally
KlKl't-llour Standards
IO cug/n.' Second hlgli
IO nig/in^ Statistical
10 IIIK/OI Dally maKlmunt
14 I»K/"' Statistical
14 in^/ia* Dally maximum
R mg/iu Slat I a lira I
'8 m|;/u>' Dully maximum
1.-ll.il- (.-I
STATUS AND NIIHHF.II OF COUNTII..S rilO.IIXTF.II TO UK IN VIOLATION OF
VAN HIUS KTANIIAKDS IN 1987
Scenario 1
I/H i-f li-ct IveiiL'h.s factors from HOIII I.F. 1 reduced by a factor 0.5* for
I, -ii |>erauiri'S ^50°F. Otlu-r as.-iuiunt Ions as In Table 4-6 — Scenario 1.
loi.il n.iiluiiat |>rojei:u-.l i:ml s:> Inns In 19117 wltb FMVF.CI' only - 69.6 x
No. of Couii-
tlus In Vio-
lation In
19
15
14
50
48
96
98
164
165
162
98
*5
176
171
No. of Coun-
tli-a Projec-
ted to be In
Violation In
1987 with
only FMVECP
2
2
2
11
10
56
51
79
H9
6H
10
21
121
116
Total Addi-
tional Needed
reduc t ionti
1000 tons
1.110
1.040
610
2.890
2.B60
10,480
10,190
I0.4HO
12.060
10.020
5.140
4.620
16.190
11.150
deductions ACCOIIT-
ullfthed by 1/Mwlil
'10 1 stringency anil
5* TCH 1000 ioiia
950
B60
4 'Ml
1.410
1.190
1 . 40O
1.100
4,220
4.450
4 . 1 1)0
1,200
2 , 700
4 , H90
4.750
No. of cour-
Hllll 111
Violation
2
2
2
4
5
19
1H
44
57
41
15
9
99
B7
Scenario 2
I/H effect Ivene.-is f.iclora given by MOUI I.C 1 used wltliout any ad)usl-
ueiit. Ollu-r assumnl Ions as In Table 4-6, Scenario 2. Total natlon-
il |>roj>-cted emlnn Ions In I9B7 will. t'MVKCf only - 60.9 x IO6
tons/year .
No . of coun-
ties still
In Violation
19
15
14
50
4a
96
98
164
165
162
9B
95
176
171
No . of Count lea
I'lOjecteil to
be In Viola-
tion in 1987
will, only KHVtCP
0
0
0
0
0
26
27
24
12
19
5
2
71
57
Total Addi-
tional Needed
Reduct iona
1000 tons
0
0
0
0
0
1.510
1,005
4.B90
5.210
4,760
4,170
2, BOO
6.180
S.420
Hedurt Ions Accon|>l islied
by I/H with 10Z strin-
gency and 51 TCH 10OO
tonu
0
0
0
0
0
210
50
4 . 600
4.600
4 . 600
4.070
2. BOO
6.180
5.420
Nu. of
Count l<-o
still In
Violation
0
O
0
0
O
6
6
7
2
2
u
24
11
•I/H fmrtora ralcululi'd by HOHIl.tlaru believed to be loo i>pc luilHl li- for t eiuyeral ureu <5O»F. AH atirll flli-ut:
fnctoru were reduc.t-d by 0.5 to l.o on tin- ronsi-rvnt Ive Hlilc In Srenurlii I.
.Source: Ki-uultti gi-neraird by Sill Inti-mnt lonuI'« com|iutt!r
-------
and maintenance costs.
Referring now to Tables 4-6 and 6-1, the following observation can
be made.
1. As is expected, the higher the stringency of standards, the
higher the needed reductions in CO. Whereas a substantial
number of counties are projected to attain the various
standards in 1987 due to the effects of FMVECP, a significant
number of counties will still fail to meet the standards,
3
particularly the 1-hour 17 rag/in- standards and almost all of
the eight-hour standards. For example, even in the optimistic
case of scenario 2, there will be potentially 24 counties that
might be in violation of the current 8-hour standards of
2
10 mg/'ar (second high) . If. more stringent standards are con-
sidered, e.g., 8-hour standard of 8 mg/'m , the number of
counties potentially in violation will be 73 and 57 respective-
ly for statistical and daily maximum standards. The numbers
are considerably higher for the relatively more pessimistic
case (scenario 1), e.g., 123 and 116 as compared to 73 and 57.
2. The implementation of I/M programs and TCM strategies is quite
effective in reducing the number of non-attainment counties
by 1987. For example, considering the current 8-hour standard
of 10 mg/m , second high, the number of counties presently in
violation is 164. If only FMVECP is considered, then by 1987
this number is reduced to 79 in scenario 1 and to 24 in scenario
2. The implementation of I/M and TCM programs reduces this
number further from 79 to 44 in the pessimistic case (scenario
77
-------
1) and from 24 to 3 in the optimistic case (scenario 2).
3. There will still be a few counties in violation of the
proposed standards in 1987 even after implementing FMVECP and
suitable I/M and TCM programs. For example, in the pessimistic
case, the number of counties projected to be in violation of
present 8-hour standard is 44 and in the optimistic case it is
3 even after implementing I/M and TCM strategies.
The basic conclusion based on the study of Table 4-6 and 6-1 is
that setting and enforcing of any of the fourteen standards will result
in considerable reduction in CO emissions in future years. The number
of counties projected to be in violation will also decrease substantially.
However, some control strategies in addition to I/M and TCM might be
needed if it is to be ensured that no county remains in violation by
1987. These might include some stationary and point source control
strategies. Specific details will have to be analyzed on a county by
county basis.
6.3 Energy Impacts
The setting up of various standards and implementation of I/M and
TCM programs to meet the standards results not only in CO emission re-
ductions but also in some saving in gasoline. In case of I/M programs,
this saving results because the automobiles that, are required to be
repaired to meet emission standards run more efficiently after being
repaired and, thereby, consume less gasoline. In case of TCM, the
saving results because each of the TCM strategies result either in re-
duced vehicle miles of travel or improved traffic flows, both of
which also result in saving in gasoline. Estimated savings in gasoline
78
-------
for Che two scenarios presented above were calculated using judiciously
selected procedures and assumptions. A brief description of these
procedures and assumptions is included in Appendix C for quick reference,
Details of the methodology are included in References 1 and 2.
Table 6-2 shows the estimated gasoline savings for various
standards due to the implementation of I/M and TCM strategies.
79
-------
Table 6-2
ESTIMATED FUEL SAVINGS IN 1987 DUE TO I/M AND TCM
PROGRAMS TO MEET VARIOUS CO STANDARDS
CD
o
A. One-Hour Standard
3
40 mg/m second high
3
40 nig /in Statistical
40 ing/m Daily maximum
3
29 nig/ in Statistical
3
29 mg/ni Daily maximum
17 mg/m Statistical
3
17 mg/m Daily maximum
15. Eight-Hour Standard
10 mg/m Second high
3
10 mg/m Statistical
10 mg/m Daily maximum
3
14 mg/m Statistical
14 mg /m Daily maximum
3
8 mg/m Statistical
3
8 nig /m Daily maximum
Scenario 1
(Refer to Table 6-1 for details)
10 gallons/year
55.9
48.9
29.2
96.9
90.6
631
611
661
875
647
380
287
1213
1120
Scenario 2
(Refer to Table 6-1 for details)
10 gallons/year
46.3
17.8
17.8
62
43
240
234
293
322
270
237
104
553
348
Source: Results generated by SRI International's computer program.
1,2
-------
REFERENCES CITED IN CHAPTER 6
1. SRI International, Computer Aided Methodologies to Conduct Regula-
tory Impact Analysis of Ambient Air Quality Standards for Carbon
Monoxide, Menlo Park, CA. September 1979. (SRI project 6780)
2. SRI International, Programmer's Manual "Programs to Conduct Regu-
latory Impact Analysis of Ambient Air Quality Standards for Carbon
Monoxide", Menlo Park, CA. September 1979. (SRI project 6780)
81
-------
7. SECONDARY ENVIRONMENTAL IMPACTS
OF THE PROPOSED ACTIONS
7.1 Other Air Pollutants
7.1.1 Mobile Source Controls
The most common exhaust device for controlling CO and HC emissions
from automobiles in the United States is the oxidation catalyst. Cata-
lytic efficiency is determined to a large extent by air/fuel mixture
control. Because there is a trade-off between the formation of NOX
and CO, air-rich combustion used to reduce CO encourages the formation
of NOX (due to oxidation of the nitrogen in the air).
While controlling CO may result in the formation of other air
pollutants such as NOx, advances in technology have made possible the
control of these other pollutants. Reduction.catalysts, for example, can
reduce nitrogen oxides to nitrogen and oxygen in a fuel rich atmosphere.
An oxidation and reduction catalyst are sometimes used in series, and
the combination is called a dual catalyst system.
Thermal reactors use excess oxygen and high temperatures to
oxidyze CO and HC. They are sometimes used in connection with a
reduction catalyst to also control the NOX. Since the introduction of
the oxidation catalyst, thermal reactors are found primarily on rotary,
lean-burn, and stratified-charge engines.
Three-way catalyst systems simultaneously reduce oxides of nitrogen
while oxidizing hydrocarbons and CO. These catalysts are being
developed to meet the new, stricter air pollution standards. Some are
already in service. The most effective, if also the most expensive,
appears to be Volvo's Lambda-sond system, where exhaust emissions are
passed over a three-way catalyst that enables the unburned hydrocarbons
and CO to react with the NOX and eliminate all three pollutants.
82
-------
Other than NO , there has been some concern that catalysts would
oxidize sulfur dioxide into sulfuric acid, resulting in high levels of
S02 along heavily traveled roads. Two tests performed in the mid-1970s
found that the catalysts do not oxidize as much of the sulfur as originally
estimated and that, because the acid is formed as very small aerospls.^,
it disperses as though it were gas. Also, the reducing segment of three-
way catalysts substantially reduces emissions of sulfuric acid.
• Inspection and Maintenance Programs
• - There are no secondary pollutant emissions from inspection and
2
maintenance programs.
• Transportation Systems Management Programs
The strategies that reduce CO emissions (e.g., traffic operations im-
provement, signalization improvement, freeway management, etc.) tend to
increase NO^ emissions. Typically, a 1% reduction in CO emissions due to
TCM could potentially result in 0.2% increase in NO . However, future auto-
X
mobiles are believed to have devices that will reduce CO, NO and HC simul-
X
taneously. . HC emissions are also reduced by about 0.5% for every 1% re-
duction in CO due to TCM.
7.2 Alteration of Atmospheric Properties
Carbon monoxide does not absorb radiation in the visible and near ultra-
violet region of the electromagnetic spectrum. As such it is inferred that
the light transmissions and heat transmission properties of atmosphere are
not affected by CO. Any contribution that CO could make in the formation of
smog will be reduced by reductions in CO emissions due to the implementation
of any of the standards and can only be beneficial.
83
-------
7.3 Water Quality
Present evidence suggests that the projected emissions of carbon
monoxide in the atmosphere from man-made sources will not degrade water
quality. Carbon monoxide is a stable compound which is only slightly
soluble in water (2.14 ml/100ml at 25°C). The oceans contain high
concentrations in their surface waters as a result of the production by
CO by algae and other microorganisms. In fact, natural sources of
carbon monoxide are much larger than man-made sources, and, therefore,
have a substantial buffering effect on man's influence.
Carbon monoxide is not now considered a hazardous or toxic pollu-
tant in drinking water. It does not appear in the Proposed Water Criteria
for Toxic Pollutants or among the pollutants identified by the proposed
Q
regulations implementing the Safe Drinking Water Act.
The fate of carbon monoxide in the atmosphere has not been well
characterized. Some research indicates that CO may react to form nitro-
gen dioxide and carbon dioxide in the atmosphere. These two compounds
have been linked to potentially significant water quality problems.
Nitrogen dioxide has been implicated as a contributor to acid rain prob-
9
lams, whereas, carbon dioxide has recently been identified as a contri-
butor to long-term increased acidity in the oceans. However, the degree
to which CO-NO- and CO-CO™ reactions occur and their effect on atmospheric
5 9
levels of nitrogen dioxide and carbon dioxide is unclear. ' Much
additional research is required to identify the importance, of these
reactions to the biogeochemical cycle of carbon monoxide.
84
-------
7.4 Ecosystems
Plants are relatively resistant to carbon monoxide, compared to
several other major air pollutants such as SO^, 0., and HF. Consequently,
few studies have been conducted on the effects of CO at ambient concen-
trations. The limited data that are available have been recently summa-
rized by the National Research Council (1977) and by EPA (1978). These
reviews point out that visible effects on plants at typical ambient CO
concentrations (from one hundred to several thousand ppm) can produce
various abnormalities. These include leaf abnormalities, the suppression
of nitrogen fixation in the soil or root nodule formation, suppression
of photosynthetic rate, and alteration of sexual expression.
Alteration of leaf formation has been shown in chamber studies
at concentration.as low as 24 ppm of CO. However, no difference was
- A
noted in the growth rates of exposed plants compared to the controls.
One ctudy hac unexpectedly shown that low CO levels (l-10ppn) inhibit
C0? uptake by the detached leaves of four plant species. These results
have not been confirmed. This same study, as well as several others,
have shown that several plant species metabolize CO photosynthetically
under conditions of unnaturally high CO levels, and thus act as a natural
sink for this pollutant. Soil microorganisms, however, are generally
considered to be a much larger natural sink for CO than plants. Moreover,
certain species of plants, particularly aquatic plants, have been shown
to produce CO. (As noted in Section 7.3, CO is not a water pollutant.)
Since plants can both metabolize and produce CO, low levels of this
pollutant are now-being considered a normal constituent of the plant
environment, and a "threshold" concentration for CO does not appear to
exist for plants.
85
-------
Little is known about the effects of CO on consumer organisms in
ecosystems under field conditions. Most animal studies on CO effects
have been conducted in laboratory conditions with mammals being used as
surrogates for humans. It has been well established, however, that
adverse health effects of CO in mammals are due primarily to diminished
oxygen (0-) transport by the blood and to interference with biochemical
utilization of .0- in tissues. Hemoglobin, the iron-containing protein
in blood, combines readily with either Q, or CO, but its affinity for CO
is 240 times greater than its affinity for 0~.
6
Experiments on mammals have shown the following:
Toxic effects of high levels of CO (greater than 100 ppm)
are well documented.
Definite effects of CO may be seen in general overt behavior
at. 200 ppm and, possibly low as 100 ppm, depending on the
species and test.
Abnormalities of the cardiovascular system have been noticed
after relatively long-term intermittent exposure to 100 ppm
CO and sometimes,, depending upon the species, exposure to
regimen and other experimental variables, at as low as 500
ppm.
Several other physiological changes have been shown at levels
of 50 ppm and greater; a few studies have shown minor biologi-
cal effects.(e.g., small changes in enzyme activity) at levels
around 20 ppm. However, no studies have shown long-term
effects on animals at levels as low as 15 ppm, including the
results of special risk, cases such as pregnant females.
86
-------
Several studies have shown that animals exposed to CO
eventually develop some physiological responses which tend
to offset the deleterious effects; however, little is known
about the interactions of CO with other pollutants, drugs,
and other environmental conditions.
On the basis of the above information, reducing the one-hour CO
standard from 35 ppm to any of the proposed values
have no adverse effects on animals, and might have some minor beneficial
effects. Changing the eight-hour standard from 9 ppm to any of the pro-
posed values (7-15 ppm) would probably have no appreciable effects on
animals, since the proposed values appear to be below the concentrations
at which adverse effects are observed.
All of the alternative CO standards fall into a relatively narrow
range of low concentrations generally below levels at which adverse
effects are observed in vegetation or animals. Although there are evi-
dently no studies of the subject, chere probably are no ecosystem effects
(i.e., effects on the relationship among plants and animals) at these
levels either. Consequently, no differences in effects can be attributed
to the alternative standards under consideration.
87
-------
7.5 Esthetics
Carbon monoxide is a colorless, odorless and tasteless gas with
no known detrimental esthetic effects and no effects on eye irritation.
88
-------
REFERENCES CITED IN CHAPTER 7
1. Stern, Arthur C., School of Public Health, University of North
Carolina, Air Pollution, Volume IV, Engineering Control of
Air Pollution, Academic Press, New York 1977.
2. Emission Standards and Engineering Division, Control Techniques for
Carbon Monoxide Emissions, Durham, North Carolina, U.S. Environmental
Protection Agency, June 1979 (EPA 450-3-79/116).
3. System Design Concepts, Inc., and JHK Associates, TSM Planning,
Vol. II, The Effects of TSM Actions in Selected Applications,
June 1978.
4. Frank P. Grad et. al., The Automobile and the Regulation of Its
Impact on the Environment, p. 52, University of Oklahoma Press,
Norman, 1975.
5. National Academy of Sciences, Committee on Medical and Biologic
Effects of Environmental Pollutants, Carbon Monoxide, Washington
D.C. 1977.
6. Office of Research and Development, Environmental Criteria and
Assessment Office, Air Quality Criteria for Carbon Monoxide External
Review Draft, Research Triangle Park, North Carolina, U.S. Environ-
mental Protection Agency, 1978.
7. Toxic Material News. March 21, 1979.
8. Federal Register. December 24, 1975, p. 59566.
9. Office of Air Quality Planning and Standards, Draft Environmental
Impact Statement: Proposed Short-Term National Ambient Air Quality
Standard for Nitrogen Dioxide, Research Triangle Park, North
Carolina, U.S. Environmental Protection Agency, 1978.
10. Chakrabarti, A.G., "Effects of Carbon Monoxide and Nitrogen
Dioxide on Garden Peas and Stringbeans", Bull. Environ. Contam.
Toxicol.. (15: 214-22, 1976).
11. Bidwell, R.G.S. and D. E. Frazer, "Carbon Monoxide Uptake and
Metabolism by Leaves," Can. S. Botany, (50: 1435-1439, 1972).
89
-------
8. OTHER RELATED CONSIDERATIONS
8.1 Potential Mitigating Measures
While controlling CO may potentially result in a slight increase
in NO , advances in technology have made it possible to minimize this
effect as was discussed in Chapter 7. For example, reduction catalysts
can reduce nitrogen oxides to nitrogen and oxygen. Thermal reactors
can also be used in connection with reduction catalyst to control NO .
• - J x
•On a nationwide scale, any potential adverse effect due to increase in
NO , which is likely to be minimal, is greatly outweighted by the ex-
*t
pected benifits from reduced CO emission and and ambient concentrations.
8.2 Unavoidable Adverse Impacts
8.2.1 Air Quality
No mention of any unavoidable adverse impacts due to
control of CO could be found in literature or discussions with experts.
8.2.2 Water Quality
As indicated in Chapter 7, the projected emissions of
CO will not degrade water quality and as such are not expected to have
any unavoidable adverse impacts on water quality.
8.2.3 Ecosystems
No significant adverse effects on plants, animals, or
ecosystems are expected for any of the proposed standards, as discussed
in Chapter 7.
90
-------
8.2.4 Esthetics
No adverse esthetic effects are expected due to reduction
in CO emissions as indicated in Chapter 7.
8. 3 Relationship Between Short-Term 'Uses of Man's 'Environment and
Enhancement'of Long Term Productivity
Th.e short term effects of CO control are a potential increase in
NO emissions that is expected to be minimal. Furthermore, the new
iC
technology for controlling CO is being improved to simultaneously reduce
NO'.' The long term impacts of the proposed actions are primarily
^£
'associated with reduced levels of CO at the urban areas and national
levels and. will produce substantial beneficial effects, related parti-
cularly to human health.
8.4 Irreversible and Irretrievable 'Commitment of Resources
Materials required to implement the Mobile Source Control strategies,
e.g., testing equipment at I/M stations, automobile exhaust emission
control devices, etc., may commit resources such as certain metals and
chemicals that may be considered irreversibly committed. However, this
resource commitment has not been quantified.
91
-------
Appendix A
Non-Attainment Areas for CO NAAQS (1973)
state
Alaska
Arizona
Cal 1 form' a
••*
Colorado
ConncCT.il.-..
O.C.
Florida
Georgia
Idaho
Illinois
Indiana
AOCR
8
10
15
15
28
28
28
29
30
31
31
31
31
3i
32
36
36
'•35
• • 36
36
36
37
37
38
• f
t( '
43
• 47
50
56
56
56
64
65
67
67
80
county
District 8
District 16-
Maricopa
Pima
.. .Sacramento
Butte
Suttar
West San Diego
San Francisco
Fresno
Karn
San Joaquin
Stanislaus
;- TulaTt
Santa Barbara
Arapahoe
• ' Adams .
•• -•••••• Denver-'
• • • --- Jefferson
- • Bouldsr
..Douglas
Larimer
Weld,
£1 Paso
„
Broward
Clayton
DeKalb
Fulton
Ada
Peoria
Cook -.
Lake
Marion
city
Anchorage
Fairbanks
Phoenix-Tucson
Phoenix-Tucson
. (Sacramento)
(Chico)
(Yuba City)
(San Diego)
(San Francisco)
(Fresno)
( Bakers f is lei;
(Stockton)
(Modesto)
(ViSa; iu/
(Santa Barbara)
(Aurora)
. (Aurora)
-. (Denver;
'(Wheat Ridgo/
"(Boulder)
Fort Collins
Greely
Colorado Springs
Atlanta
Atlanta
Atlanta
Boise
Peoria
Chicago
(Hamond)
Indianapol is
:rom Federal Register of March 3, 1978,
92
-------
state
AQCR
county
Iowa
Kansas
Kentucky
Maine
Maryland
Massachusetts
Michigan
Minnesota
Missouri
Montana
Nebraska
Nevada
65
65
94
100
78
107
109
113
113
115
47
118
119
"119
119
119
121
42
122
123
127
128
129
131
. 70'
140
144
85
145
13
148
148
Des Moines
Lee
Wyandotte
Wichita
Jefferson
Androscoggi.n
Penobscot
Allegany
Washington
Baltimore
National Capital
Worchester
• . • Suffolk
• Middlesex
Middlesex
Middlesex
... Meddlesex
•.. ..- Harapden
Wayne
Benton-Sherfaorne-
Stearns
Olmstaad
St. Louis
Hennepin-Ramsay
.St.. Louis
Yellowstone
Missoula
. Douglas
Lancaster
Clark
Washoe
Douglas
Des Moines
Lee Township
Kansas City
Wichita
Louisville
Lewiston
Bangor
Cumber! and
Hagerstown
Baltimore
Worchester
Bostci.
•Cambridge
Medford
Waltham
.Lowell
- ...Springfield
• Detroit
St. Cloud
Rochester
Duluth
•Minneapol is-St. Pau
. . St. Louis
Billings
Missoula
Omaha
Lincoln
Las Vegas
Truckee Meadows
. Lake Tahoe
New Hampshire
121
Hillsborough
Manchester
93
-------
stats
AQCR
county
city
New Jersey 43
43
43
43
43
43
43
43
43
43
43
45
45
150
150
150
.'.... . ... 150
New Mexico 14
. 152
153
.. . 157
.- New .York 43
• • • 43 •
. 43
43
153
160
•• • • • 151
161
161
161
161
162
162
162
161
North Carolina 166
167
Ohio 79
124
173
174
174
Passaic
Bergen
Hudson
Essex
Union
Morris
Middlesex
Somerset
Monmouth
Monmouth
Mercer
Burlington
Camden
Salem
Camp May
Atlantic
. . r Ocean
San Juan
Bernadillo
. ; Dona Ana
... .....Santa Fe
• • Westchester
Westchester
Nassau
Onondagn
Monro
Rensselaer
-
Albany
Al bany
Al bany
Erie
Erie
. • -.• Schenectady
Durham
Mecklenburg
Hamilton
Lucas
Montgomery
Summit
Cuyahoga
Paterson
Hackensack
Jersey City
Newark
Elizabeth
Morn's town
Perth Amboy
Somerville
Asbury Pauk
Freehold
Trenton
Burl ington
Camden
Penns Grove
Wildwood
Atlantic Ci
. /. Toms River
Farmingtcn
Albuquerque
. .. • Las Cruses
. . . Santa Fe
. New York Ci
Yonkers
Mt. Vernon
Syracuse
• Rochester
Troy
Waterford
Water/I iet
Albany
Colonie
Buffalo
Cheektowaga
Amherst
Schenectady
Durham
Charlotte
Cincinnati
Toledo
Dayton
Acron
Cleveland
ty
ty
\
94
-------
state
AQCR
county
city
Ohio
Oklahoma
Oregon
Pennsylvania
Rhode Island
South Carolina
Tennessee
.Texas
Utah
Vermont
Verginia
Washington
176
178
181
186
193
193
193
194
45
197
120
. 167
200
' 18
. 207
.-. .208
' ,.153
•220
220
220
- 220
159
47
47.
62
'229
230
Franklin
Mohoning
. Jefferson
Tulsa
Marion-Polk
Clackamas-
Multnomah
Lane
Jackson
Philadelphia
Allegheny
Providence
York
Rich! and
Shelby
.Knox . '
•. - ..'....Davidson • •
• . ...El Paso ' '- "
Salt Lake
Davis
Weber
Utah
(Champlain Valley)
Alexandria
Fairfax
Spokane
King-Pierce
Yakima
Columbus
(Youngs town)
.(Steubenvil le)
Tulsa
Salem
Portland-Vancouver
Eugene-Springfield
.Medford-Ashland
Philadelphia
Pittsburgh
Providence
•Rock Hill
Columbia
Memphis
Knoxville
Nashvil le
£1 -Paso
Salt Lake City
Bountiful
Ogden
Prove
• Alexandria
Fairfax
Spokane
Seattle-Taccma
Yakima
Wisconsin
239
Milwaukee
Milwaukee
Note: counties or city listed in parentheses were not listed in the
.Federal Register notice; they represent best judgement estimates
of specific geographical areas mentioned in more general terms
in the notice.
95
-------
APPENDIX B
List of the 272 Counties Included in the County Files
1
2
3
4
5
*
7
8
Q
10
11
12
13
14
*15
*16
17
18
19
*20
21
22
23
£4
25
26
27
23
29
30
31
32
*"i-*t
•30
34
35
3*
OT*
•V 1
33
39
40
41
42
43
44
45
46
47
4:5
49
50
51073
51 097
52020
52090
54 0 1 :":
54019
56001 i
56007
56013 i
06019
06029
06 037
06041
0.6047
06055
•06059
06061
06065
U 6 U 6 7
0607 1
06073
06075
06077
06 0:? 1
060:33
060S5
06037
06095
06097
06 1)99
06 1 0 1
061 07
06 1 1 1
06113
0300 1
0:3005
OS 0 1 3
0:3031
0:3035
0:3041
03059
0-3069
0:3123
0900 1
09003
09005
090i''7
09009
0901 1
09013
JEFFERSON
•1GB I LE
^NCHGPRbE
-RIPERNKS
•1RPICCFR
5 I MR
=>LRNEDR
BUTTE
"'GNTRRCGSTR
FRESNO
KERN
LOS RNGELES
MRP IN
MERCED
NRPR
OPRNGE
PLRCEP
RIVERSIDE
;:HL:RR'ME:NTa
SRN BEPr-iRDING
2RN DIEGO
iRN FFRNCISCG
i.RN JGROUIN
JRN MR TEG
SRNTR 5RPERRR
SRNTR CLRPR
SRNTR CRUZ
SCLRNG .
SONG MR
STRNISLRUS
SUTTER
TULRRE
VENTURA
YGLG
RBRNS
RPRPRHGE
EOULIiEP
DENVER
BGUGLRS
ELPRSO
JEFFERSON
LRPIMER
MELD
FRIPFIELD
HRPTFOPD
LITCHFIELD
MIDDLESEX
NEi.'iHRVEM
NEI.ILONDON
TOLLRND
RL
RL
RK
RK
RZ
RZ
T-R
I:R
I'R
CR
CR
CR
CR
CR
CR
CR
CR
/CR
CR
CR
CR
CR
CR
CR
CR
CR
CR
CR
CR
CR
Cfl
CR
CR
CR
CD
CD
CD
CD
CG
CG
CO
CD
CO
CT
CT
CT
CT
CT
CT
CT
51
52
53
*54
55
56
57
53
59
60
61
*6£
63
*64
65
A6
*67
63
69
*70
71
72
c-.<
74
*75
76
*77
*7:3
*79
30
31
*:32
33
84
*'S5
36
37
-' 1-1.-!
'.'O
39
90
*91
*92
93
94'
*95
96
97
<3O
1 0003
11 0 0 0
12011
12019
12025
12031
12057
12095
12099
12103
12127
13047
13063
13067
130=39
13121
13295
16001
17 031
17097
17119
17143
17161
17163
17179
17197
13 019
13043
13057
130:39
13097
13127
19113
19153
19155
19163
2 0 0 0 0
20173
2 0177
20209
21015
21037
21059
21111
21117
21145
22 033
NEI..JCRSTLE
DIST COLUMBIA
99 23019
100 24001
CLRY
DRDE
DUVRL
HILLSEOROUGH
ORANGE
•PRLM BERCH
FINELLRS
VGLUSIR
CRTOGSR
CLRYTQN
COBE
DEKRLB •-
FULTON
WALKER
RDR •
COOK-
LAKE
MADISON
FEGPIR
ROCK ISLAND
ST CLRIR
TPZEWELL
MILL
CLARK
FLCYD
HAMILTON
LRKE
MARION
PGPTER
LINN
POLK
PGTTfli.lRTRME
SCOTT
DOUGLAS
SEDGWICK
SHRi.iNEE
WYANDOTTE
BOONS
CAMPBELL
DRV I ESS
JEFFERSON
KENTGN
MCCPACKEN
E.BATOMPDUGE
RNDFG:-~CQGGIN
PENOBSCOT
ALLEGHANY
DE
DC
FL
FL
FL
FL
FL
FL
FL
FL
FL
GA
GA
GA
GA
GA
ID
IL
IL
IL
IL
IL
IL
IL
IL
IN
IN
IN
IN
IN
IN
IA
IA
IA
IA
•_>
KS
KS
KS
KY
KY.
KY
KY
KY
KY
LR
ME
ME
MD
These counties have only population data"(1970, 1980, 1985, 1990) and 1977
car count in the file. These counties are included to complete urban area
tables and to calculate I/M costs and gasoline savings for urban areas assuming
the CO emissions are proportioned to car counts.
-------
101
102
1 03
104
*1 05
1 06
107
1 OS
' 1 09
*110
111
112
113
114
115
*116
117
113
119
120
121
122
123
*124
125
126
*127
*t£3
129
130
131
132
133
134
135
*136
137
133
139
140
141
142
143
144
145
146
147
143
149
150
24 0 03
24005
24031
24033
24043
24510
25005
25007
25 0 03
26031
26099
26125
26145
26163
£7.0.03
27009
27019
27037
27053
27109
27123
27137
27139
27141
27145
27163
29077
291*3
29139
295 1 0
3 0 0 0 0
30063
30111
31 055
31 109
31153
32003
32 0 05
32029
32031
32510
33 0 0 1
33011
33013
33015
34001
34003
34005
34007
34 0 09
RNNE RPUNBEL
BRLTIMCPE
MONTGOMERY
PRINCE GEDRGE
WASHINGTON
BRLTIMGPE CIT
CENTFRL
PIONEER
BOSTON MET
KENT
MRCGME
CRKLRMD
SRGINfiW
WAYNE
RNGKR
BENTGN
CRPVER
BRKGTR
HENNEPIN
DLMSTED .
PRMSEY
ST LOUIS
SCOTT
SHEPBOPNE
S i EfiRNS
WRSHINGTGN
GREENE
ST CHRFLES
ST LOUIS
ST LOUIS CITY
URSCRBE
MI 3 SOUL A
YELLOWSTONE
DOUGLAS
LRNCRSTEP
SRPPY
CLRPK
DOUGLAS
STOREY
WfiSHDE
CRPSDN CITY
CDDS
HILLS BOROUGH
MEPPIMACK
PQCKINGHAM
RTLRNTIC
BE P GEN
BURLINGTON
C RMD EN
CRPEMRY
MD
MD
MD
SMD
MD
YMD
MR
MR
MR
MI
MI
MI
MI
MI
MM
MM
MM
MN
MM
MN
MM
MM
MM
MN
MN
MN
MD
MI
MD
MO
MT
MT
MT
ME
ME
ME
NV
NV
NV
NV
NV
NH
NH
NH
NH
NJ
NJ
NJ
NJ
NJ
Mil
MD
MD
JMIi
MD
Y'MD
MR
MR
MR
MI
MI
MI
MI
MI
MM
MN
MN
MM
MN
MM
MM
MM
MN
MM
MN
MD
MI
MD
MD
MT
MT
MT
ME
NE
ME
NV
NV
NV
NV
NV
NH
NH
NH
NH
NJ
NJ
NJ
NJ
NJ
151 34013
• 152 34015
153 34017
154 34021
155 34023
156 34025
157 34027
153 34029
159 34031
*160 34033
161 34035
162 34039
*163 34041
164 35001
165 35002
166 3501:":
167 35045
lf.fi •md4*
169 36ui.il
17i"i ssrifi.s
171 36029
172 36047
173 36055
174 36059
175 36061
176 36063
177 36067
173 36031
179 36033
*130 36035
*131 36037
132 36093
- 133 36097
*1 34 36 1 1 9
135 .37063
136 37119
*1S7 39017
. 133 39023
*139- 39025
190 39035
191 39049
192 39057
193 39061
194 39031
* 195 39035
196 39095
197 39099
193 39H3
*199 39133
£00 39151
3 ESSEX NJ
GLDUCESTER NJ
HUDSON NJ
MERCER NJ
MIDDLESEX NJ
MDNMDUTH NJ
MCPPIS NJ
DCEHN NJ
PRSSRIC NJ
SRLEM NJ
SOMERSET NJ
UNION • NJ
WflRREN NJ
BERNhLILLD MM
CHhVES NM
DOM* HNR • • NM
S*N JUhN NM
SHNTR FE NM
RLBRNY NY
BRONX NY
ERIE ' NY
KINiJS NY
MONROE NY
NRSSRU NY
MEW YORK . NY
NlRijRRR MY
ONONDft'Sfi MY
QUEENS MY
PENSSELRER NY
RICHMOND MY
ROCKLRMD MY
SCHENECTfiDY NY
SUFFOLK MY
WESTCHESTEP NY
DUPHRM MC
MECKLENBURG NC
BUTLER DH
CLRPK OH
CLEPNCMT ' DH
CUYRHDGR GH
FPRNKLIN DH
GREENE OH '
HAMILTON DH
JEFFERSON DH
LRKE DH
LUCRS DH
MRHDMIMG DH
MONTGOMERY DH
PDPTRGE DH
STRRK OH
97
-------
£01 39153 SUMMIT
£0£ 39153 TPUMBULL
*£03 39173 MOOD
*£04 40027 CLEVELAND
£05 40109 OKLAHOMA
206 40143 TULSA
£07 41003 CLACK AM AS
£•0:3 41029 JACKSON
• £09 41039 LANE
£10 41047 MARION
£11 41031 MULTNCMAH
£1£ 41067 WASHINGTON
£13 4 £003 ALLEGHENY
*£14 4£ 007 'BEAVER
*£15 4£017 BUCKS
£16 4£043 DAUPHIN
*£17' 4£045 DELfiWRPE
£13 4£069 LRCK'Ri.'.iRNHR
£19 4£077 LEHIGH
££0 4£079 LUZEPNE
££1 4£095 NGPTHRMPTDN
£££ 4£101 PHILRDELPHIR
*££3 4£1£9 WESTMCRSLPNIi
*££4 44001 BRISTOL
££5 -14003 KENT
££6 44007 PROVIDENCE
££7 -44009 l.iiRSHINGTGN
££S 43019 CHARLESTON
*££9 45063 LEXINGTON
£30 45079 PICHLRND
£31 45091 YORK
£3£ 47037 DRVIDSGN
£33 47065 HRMILTDN
•£34 47093 KNOX
£35 47157 SHELBY
'£36 4oO£9 BEXRR
£37 43113 DfiLLfiS
£33 43141 EL PflSO
£39 43£01 HRPPIS
£40 43353 NUECES
£41 43439 TRPPRNT
£4£ 43453 TPRVIS
£43 4901 1 DRV IS
£44 49035 SRLT LflKE
£45 49049 l.iTRH
£46 49057 MEEER
£47 5 0 0 0 7 C H I T T E N D E f-J
£43 51013 RPLINGTOfi-
*£49 51041 CHESTERFIELD
£50 51059 FAIRFAX
QH
GH
GH
GK
GK
OK
OR
OP
OR
OR
OP
GP
PR
PR
PR
PR
PR
PR
PR
PR
PR
PR
PR
PI
PI
PI
PI
SC
sc
SC
sc
TN
TN
TN
TN
TX
TX
TX
TX
TX
TX
TX
UT
UT
UT
UT
VT
VR
VR
VA
HENRI CO
PCANGKE
RLEXANCPIA
CHESAPEAKE
HAMPTON
NORFOLK
PDPTSMDUTH
RICHMOND
VIRG BEACH
CLARK
KING
PIERCE
SNOHCMISH
SPOKANE
YAK IMA
BROOK
HANCOCK
DOUGLAS
KENOSHA
MILWAUKEE
GZAUKEE
I..JAUKESHA
L- r
VR
VR
VR
VR
VR
VR
VR
VR
VR
I...IR
I...IR
I.IR'
I...IR
l.JR
WR
WV
I...IV
i.i I
w r
i.i i
i...i i
i.i i
98
-------
APPENDIX C
Methodology to Project CO Emissions and Analyze
The Effects of I/M and TCM Programs
The overall logic of the computer program developed by SRI Inter-
«s
national in close consultation with EPA can conveniently be esplained by
*
considering a single county and noting that certain basic data about
each county is stored in a county file, Tables of CO reduction factors
due to Federal Motor Vehicle Emission Control Program (FMVECP) and re-
duction factors due to Inspection and Maintenance (I/M) programs are also
stored separately.
With the above-noted background information, the basic logic of the
program can be stated as follows.
1. The existing design value of CO concentration corresponding
to the standard being considered is comprared with the value
of the standard. If the design value is less than the value of
the standard, the county is net in violation of the standard
and is not analyzed any further for that standard. If the
design value is greater than the value of the standard, the
needed percentage reduction (also called Roll Back) is calcu-
lated. For example, suppose the current eight-hour second
high design value of a county is 14 mg/m . Comparing it with
the eight hour second high standard of 10 -g/m , it is seen
that the needed percentage reduction is: —^.— x 100 3 23.6% (1)
*
See Table C-l.
99
-------
Table C-i
BASIC COUNTY RELATED DATA STORED
IN THE COUNTY FILE
1. County Code
2. County name
3.. State code
4. Area emissions 1979
5. Point emissions 1979
6. Mobile emissions 1976*
7. Emission density
8. Population 1970
9. Population 1980
10. Population 1985
11. Population 1990
12. Population adjustment factor
1980
13. Population adjustment factor
1985
14. Population adjustment factor
1990
15. VMT growth factor
16. County passenger car count
1977
17. 14 design values.
18. Temperature
19. Location code
20. Background concentration level
21. Code indicating I/H program
in county
22. Code indicating I/H program
in state
23. Urbanized area code
(e.g., 01073)
(e.g., Jefferson)
(e.g.., AL)
(tons/year)
(tons/year)
(tons/year)
(tons/sq. mile/year)
(SMSA or urban area popu-
lation to which the
county belongs)
(Based on 3EA data)
(Annual %)
(tag An 3)
(degrees F)
(low altitude, high altitude,
California)
(mg/m )
The 1979 line emissions were not readily available. However 1976 estimated
values were available based on 75° temperature. These are used as a base
value and the projecced values for 1979, 19S2, etc. are calculated by the
program using suitable factors.
100
-------
2. The above-noted reduction faccor is applied to the current
emissions of the county and total allowable emissions for the
county are calculated"by subtracting the needed emission reductions
from the existing total CO emissions. For .example suppose
the total 1979 emissions of the above-noted county is 333,870
tons/year. The needed reductions then are:
333370 x 0.286 - 95392 tons (2)
and the allowable emissions are:
•- ' 333370 - 95392 = 238478 tons • (3)
3. Projected emissions for the years 1982, 1984 and 1987 are calculated
for area, point and line source emissions. Area source emissions
are assumed either to be directly proportional to population or can
be assumed to increase with a judicously selected annual rate. Point
source emissions are projected using projections for national total
manufacturing income. Line source emissions are projected based on
the FMVECP related reduction factors and VMT growth factors. The
VMT growth factor could be chosen either on a county specific basis
based on historical data or an overall common growth rate can be
assumed for all counties.
\
4. The total projected emission for each of the three years
1982, 1984 and 1987 are compared with the allowable emissions.
If the projected emissions in 1982, 1984 and 1987 a-re all less
than the allowable emissions, the county data is not analyzed
any further. In case the projected emissions in any of the
years 1982, 1984 and 1987 is greater than the allowable
emissions, the needed reductions for the respective years'is
calculated as:
101
-------
Needed Reduction in 1982 (1984, 1987) = Projected emissions
in 1982 (1984, 1987) - Allowable Emissions.
The needed reduction is then converted to a percentage of needed re-
duction using the projected emissions of the corresponding year as
the base value. If the projected emissions are less than the allowable
emissions, the needed reductions are assumed to be zero. For example,
suppose the projected total emissions are calculated to be:
1982 267,720 tons/year
'' ' 1984 221,010 tons/year
1987 168,728 tons/year
Therefore, the needed reductions are:
1982: 267,720-238,478 = 29,242 tons
The projected emissions in 1984 and 1987 are both lass than the allow-
able emissions, therefore the needed reductions for 1984 and 1987
are assumed to be zero. The needed reduction of 29,242 tons in 1982
is expressed as a percentage of 1982 emissions, i.e.,
29 ?42
percentage reduction needed in 1982 = ?ft '" fl x 100 = 11%
5. An I/M program with an appropriate stringency is then selected. Three
stringency levels are included in the program, namely 20%, 30%, and
40%. Associated with each stringency level is an estimated percentage
reduction in CO emissions of the total car population. For example,
an I/M program with a 20% stringency, initiated in 1984 in a low
altitude area with an ambient temperature of 50°F is estimated to
reduce the CO emissions of th total car population by 13.8%. Factors
similar to this are stored in a table for various temperatures, loca-
tions and I/M program initiation years. These factors were established
102
-------
using the MOBIL 1 program developed by EPA. The values of I/M effec-
tiveness given by MOBIL 1 are believed to be optimistic for temperatures
below 50°F. As such these factors were reduced by a factor of 0.5
for regions with temperatures below 50° in scenario 1.
If possible, the smallest of the three stringency factors (i.e.,
20,30, and 40%) that produces an overall reduction at least as high
as the needed reduction is selected. However, if even the highest
of the three stringency factors does not produce the needed reduc-
.tion, then the highest stringency is selected and a need for additional
transportation control measures (TCM) is established.
6. The expected fuel saving in 1987 due to the implementation of I/M
program is calculated using essentially the following relation-
ship:
Fuel saving due to I/M = (car population) (Stringency factor)
(estimated fuel savings per repaired
car) (average annual gasoline consumption)
The results presented in this report are based on the assumption that
fuel savings due to I/M is neglegible for pre 1981 cars. For 1981
and post 1981 cars the fuel savings are assumed to be 7.5%, 6% and
4.5% for stringency factors of 20%, 30% and 40% respectively. The
percentage of 1981 and post 1981 cars in the year 1987 is assumed to
be 78.1% and annual gasoline consumption per car in 1987 is assumed to
be 430 gallons.
7. If the needed reductions in the future years are less than 5%, this is
assumed to be- realizable by TCM programs unless an I/M program already
exists or is already planned for the county. Also, if an I/M program
with the maximum allowable stringency is unable to accomplish the needed
103
-------
reduction, it is assumed that up to 5% additional reduction can be
realized through TCM programs.
Fuel saved by TCM is calculated using a relationship of the
form:
Fuel saved by TCM = (tons reduced by TCM) (Fuel saved per ton
of CO reduction by
TCM)
The results presented in this report are based on a fuel savings of
1088 gallons saved per Ton reduced of CO.
Readers who are interested in further derails of the methology are
referred to the following report:
SRI International, Computer Aided Methodologies to Conduct Regula-
tory Analysis of Ambient Air Quality Standards for Carbon Monoxide,
Menlo Park, California, September 1979 (SRI project 6780).
104
------- |