ANNUAL REPORT
OF THE
ENVIRONMENTAL PROTECTION AGENCY
TO THE
CONGRESS OF THE UNITED STATES
In Compliance With
Section 202(b)(4)
Public Law 90-148
THE CLEAN AIR ACT AS AMENDED
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PREFACE
This report is submitted to Congress in accordance with
Section 202(b)(4) of Public Law 90-148, the Clean Air Act,
as Amended. Section 202(b)(4) reads as follows:
"On July 1 of 1971, and of each year thereafter,
the Administrator shall report to the Congress
with respect to the development of systems neces-
sary to implement the emission standards established
pursuant to this section. Such reports shall include
information regarding the continuing effects of such
air pollutants subject to standards under this section
on the public health and welfare, the extent and
progress of efforts being made to develop the neces-
sary systems, the costs associated with development
and application of such systems, and following such
hearings as he may deem advisable, any recommendations
for additional congressional action necessary to achieve
the purposes of the Act. In gathering information for
the purposes of this paragraph and in connection with
any hearing, the provisions of section 307(a) (relating
to subpoenas) shall apply."
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TABLE OF CONTENTS
Page
PREFACE [[[ ii
Chapter 1: Introduction .................................... 1-1
A. Summary ............................................ 1-1
B. Conclusions ........................................ 1-8
Chapter 2 : Background ...................................... 2-1
A. History of State and Federal Emission
Standards .......................................... 2-1
B. Testing Procedures ................................. 2-3
C . Significant EPA Actions ........................... 2-5
Chapter 3: Related EPA Programs and Activities ............. 3-1
A. Introduction ....................................... 3-1
B . Establishing Standards ............................. 3-1
C. Testing and Enforcement ............................ 3-2
D. Monitoring Technological Developments .............. 3-6
E. National Academy of Sciences Contract .............. 3-7
F. Regulation of Fuel Content ......................... 3-8
G . Alternative Power Systems .......................... 3-9
H. Federal Clean Car Incentive Program ................ 3-15
I. Federal Low Emission Vehicle Purchase Program ...... 3-16
Chapter 4: Health and Welfare Effects ...................... 4-1
A. Emission Levels and Ambient Air Quality .......... 4-1
B. Photochemical Oxidants, Hydrocarbons, Carbon
Monoxide, and Oxides of Nitrogen ................. 4-1
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Page
Chapter 5: Industry Progress 5-1
A. Basic Technology 5-1
B. Typical Control Concepts and Devices 5-2
C. Industry Concerns 5-12
D. Exchange of Technical Information 5-13
Chapter 6: Costs
A. Cost of Attaining the 1975 and 1976 Standards 6-1
B. Cost Effectiveness of Motor Vehicle Control 6-5
C. Relationship between Costs and Effectiveness
in Reducing Air Pollution 6-7
D. Industry Sponsored Research and Development 6-12
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CHAPTER I: INTRODUCTION
A. Summary
The Clean Air Act as amended charges the Administrator of
the Environmental Protection Agency with major responsibilities
for the control of motor vehicle emissions. These duties
include: establishing emission standards for pollutants
which endanger public health and welfare; administrating a
number of related activities concerned with vehicle testing,
certification and enforcement; regulating the content of
fuels; demonstrating the feasibility of low-emission vehicles;
monitoring the development of improved devices to control
emissions from internal combustion engines; and directing
research and development activities related to alternative
power systems.
In addition Sections 202(b)(l)(A) and 202(b)(l)(B)
require that:
(1) 1975 automobiles achieve a 90% reduction in the
emissions of hydrocarbons (HC) and carbon monoxide (CO)
which were allowable in 1970, and
(2) 1976 automobiles achieve a 90% reduction in the
emissions of oxides of nitrogen (NOX) from the average levels
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measured on 1971 automobiles which were not subjected to
any federal or state NOX emission standards.
Under Section 202(b) (5)(D) the Administrator is per-
mitted to suspend the 1975 and 1976 standards for up to one
year, only if he determines that:
"(i) such suspension is essential to the public in-
terest or the public health and welfare of the
United States,
(ii) all good faith efforts have been made to meet
the standards established by this subsection,
(iii) the applicant has established that effective
control technology, processes, operating methods or
other alternatives are not available or have not
been available for a sufficient period of time to
achieve compliance prior to the effective date of
such standards, and
(iv) the study and investigation of the National
Academy of Sciences conducted pursuant to subsection
(c) and other information available to him has not
indicated that technology, processes or other alter-
natives are available to meet such standards."
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Since the establishment of the Environmental Protection
Agency on December 2, 1970, EPA has completed a number of
actions related to the control of emissions from motor
vehicles. An initial contract has been signed with the
National Academy of Sciences to identify the resources
necessary to study the technological feasibility of attaining
the 1975 and 1976 standards.
EPA has published an advance notice of proposed rule-
making indicating its intention to control or prohibit the
use of alkyl lead in motor vehicle gasoline. Detailed
studies of scientific, medical, economic, and technological
data concerning this matter are currently under review.
In February, the Administrator sent a letter to all
domestic and foreign auto manufacturers requesting informa-
tion about research and testing activities related to the
development of emission control systems designed to meet
the 1975 and 1976 standards. EPA also conducted two days
of public hearings on this subject during May of 1971.
Twenty-one representatives of the automotive and related
industries, of the academic and scientific communities,
and of public interest organizations and groups presented
statements and responded to questions.
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EPA has published certification test results for 1971
model vehicles and engines. National ambient air quality
standards have been promulgated which include motor vehicle
related pollutants. Regulations have been proposed defining
the useful life of vehicles and requiring the inclusion
in owners' manuals of maintenance instructions
for emission control systems. Specific numerical standards
and test procedures have been established for 1975 and
1976 emissions of HC, CO and NOx.
Demonstration programs relating to low-emission vehicles
have been initiated. Three contracts have been signed under
the Federal Clean Car Incentive Program whereby manufacturers
provide prototype vehicles for government testing and eval-
uation.
The Low-Emission Vehicle Certification Board prescribed
by Section 212 of the Act has been established. The Board
held its first meeting in June, 1971, and adopted procedural
regulations related to the preferential purchase of low-
emission vehicles for use in government fleets.
EPA is also directing a research and development program
for low-emission vehicular power systems other than the in-
ternal combustion engine.
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Chapter 2 of this report includes a brief history of
federal and state emission control standards and test pro-
cedures. It also contains a more elaborate explanation of
EPA's initial accomplishments. Chapter 3 provides an over-
view of all of EPA's programs and activities related to the
control of motor vehicle emissions. While the industry is
giving prime attention to the development of add-on devices
to enable the internal combustion engine to meet the emission
standards prescribed in the law, EPA is also directing research
and development programs concerning alternative power systems.
Chapter 4 deals with the health and welfare effects of
motor vehicle related pollutants. While vehicular emissions
are important sources of pollution, especially in congested
urban areas, they are not the only sources of these contaminants.
In discussing health and welfare impacts it is important to
note that it is ambient air quality, the composition of a local
air mass, rather than emission levels from particular sources,
which is the significant factor although the two are clearly
related.
It is difficult to generalize about the relative importance
of various contributions of the same air contaminants to am-
bient air quality because most air masses undergo lateral
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movements. Thus relative impacts must be looked at in terms
of specific localities reflecting differences in geography,
meteorological conditions, traffic patterns and the size
and locations of all sources of the same pollutants.
A detailed discussion of the progress reported by
industry is contained in Chapter 5. This material describes
a number of control devices under development and outlines
some of the technical problems facing the industry. This
material also reiterates a number of concerns experssed by
the manufacturers in their communications with EPA.
The final section of this report, Chapter 6, deals with
the costs associated with motor vehicle emission control. It
is not yet possible to provide precise estimates of the cost
per vehicle of attaining the 1975 and 1976 standards established
in the Act. The total cost to the public will, however, include
the initial cost of the control system, its maintenance after
warranty, and expected increases in fuel consumption and
reductions in vehicle performance.
Neither the final control system needed to achieve
the 1975 standards nor the technology for attaining the 1976
standards, have yet been identified. Thus, the cost figures
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contained in Chapter 6 must be considered preliminary and
include informal industry estimates of initial costs ranging
from $80 to $600 per car for 1975. However, it appears
clear that the costs associated with 1975 and 1976 standards
will be considerably greater than those experienced in
reaching Federal emission standards through 1974.
Information provided to EPA by auto manufacturers
revealed a significant increase in emission control systems
research and development activity since the passage of the
1970 amendments to the Clean Air Act. During the first six
months of accelerated development, industry laboratories have
reported the attainment of reduced emission levels. While
there are many problems to be overcome to convert laboratory
results into reduced emission levels from mass-produced autos,
the added industry effort should improve prospects for signifi-
cant technological improvements.
B. Conclusions
During the recent public hearings industry spokesmen
expressed major reservations about the technological feasi-
bility of achieving the statutory emission standards within
the time limits prescribed by law. The manufacturers were
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unanimous in asserting that the levels of reduction
required for 1975/76 precluded the substitution of alter-
native power systems, making it essential that emission
control be achieved through an improved internal combustion
engine. Industry representatives consistently stated that
reaching the 1976 NOx emission levels goes beyond the limits
of current knowledge and will require some major technological
breakthrough early enough to permit mass production of 1976
models. They also expressed concern about the high cost of
attaining the low levels of emissions required by the statute.
At these same hearings representatives of public interest
organizations were skeptical of industry statements about
their inability to develop the necessary technology to
reduce emissions to the required levels. These witnesses
pointed to previous instances of resistance by the industrial
community to deadlines which were ultimately achieved. Sus-
picion was also voiced about the vigor of government enforcement
concerning interim standards and test procedures. This
climate of mistrust makes it important that, to the degree
possible, matters related to motor vehicle emission control
be given full public exposure.
Motor vehicle emissions are important sources of HC,
CO, and NOX pollutants especially in congested urban areas.
However, they are not the only sources of these contaminants.
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The specific contribution of vehicle emissions to the
degradation of ambient air quality is a complex matter and
varies from place to place. These variations are attributable
to differences in geography, meteorological conditions,
traffic patterns, and the size and location of other
sources of these pollutants. More information on these
matters is expected with the completion of State implementation
plans required under the legislation. These plans are also
expected to include a variety of alternative abatement
strategies. With additional information about the costs
and effectiveness of emission control from all types of
sources, it should be possible to undertake detailed cost-
effectiveness analyses in order to insure that the ambient
air quality standards are achieved at the most reasonable
cost to the American people.
One of the unfortunate aspects of motor vehicle emission
control is that reducing levels of hydrocarbons and carbon
monoxide, which is done primarily through increasing the
efficiency of combustion, tends to make more difficult the
control of oxides of nitrogen, whose formation is largely a
function of the heat of combustion. Thus, a major
technological challenge faces the Nation's auto industry
in meeting these emission standards.
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EPA is moderately optimistic that the 1975 standards
can be attained especially since it is expected that
unleaded gasoline will be generally available at that
time. We are also hopeful that technological developments
will enable the manufacturers to reach the 1976 standards.
However, the costs associated with achieving these standards
may be high. Therefore, the Agency is not recommending any
legislative changes at this time, although they may be needed
in the future.
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CHAPTER 2: Background
A. History of State and Federal Standards
The control of motor vehicle emissions was initiated in
the State of California in 1959 with the adoption of standards
to control exhaust hydrocarbons and carbon monoxide. This was
supplemented in 1960 with standards to control emissions
resulting from crankcase blowby. The early generations of
California standards were goals requiring the demonstration of
feasible technology before the establishment of implementation
deadlines. Such scheduling was contingent upon the availability
and certification of devices, systems, or modifications which
would enable motor vehicles to meet the standards. In 1963,
California adopted diesel smoke standards; however, a-s with the
previous standards, there was no immediate implementation
schedule. As a result of the certification of appropriate
devices and systems, California required a first level of
crankcase emission control effective with the 1963 models,
improved crankcase emission control for 1964, and control of
exhaust hydrocarbons and carbon monoxide in 1966.
The 1965 Amendments to the Federal Clean Air Act gave the
Secretary of the Department of Health, Education and Welfare,
the authority to control emissions from motor vehicles.
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Accordingly/ on March 30, 1966, the initial Federal motor
vehicle emission standards were adopted to become applicable
with the 1968 models. The standards and procedures were similar
to those which had been employed by California and required some
control of exhaust hydrocarbons and carbon monoxide from light-
duty vehicles and one hundred percent control of crankcase
emissions from gasoline-fueled cars, buses, and trucks. The
term light-duty vehicle refers to self-propelled vehicles
designed for street or highway use, which weigh less than 6,000
pounds and carry no more than twelve passengers. Thus, the
vehicle population is divided into two groups, light and heavy-
duty which generally correspond to cars as opposed to buses
and trucks.
On June 4, 1968, revised Federal standards were published
which required more stringent control of hydrocarbons and
carbon monoxide from light-duty vehicles,of evaporative emissions
from the fuel tanks and carburetors of light-duty vehicles, of
exhaust hydrocarbon and carbon monoxide emissions from gasoline-
fueled engines for heavy-duty vehicles,and of smoke emissions
from diesel engines for heavy-duty vehicles. The fuel
evaporative emission standards became fully effective with
model-year 1971. The other standards applied to 1970 model year
vehicles and engines. Thus with the introduction of 1970
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models, the industry had reduced hydrocarbon emissions by
almost three-quarters and carbon monoxide emissions by about
two-thirds.
On November 10, 1970, standards were published applicable
to 1972 model light and heavy-duty vehicles and heavy-duty
engines. The significant modification in these standards
pertained to the method of evaluating the exhaust hydrocarbon
and carbon monoxide emissions from light-duty vehicles.
Improved methods of test operation, exhaust sampling and gas
analysis had been developed so that emissions measurements would
be more representative of actual discharges from in-use vehicles.
B. Testing Procedures
Testing procedures are complicated and require some added
explanation. Numerical emission standards are meaningful only
when related to the specific test procedure employed. As with
many other aspects of auto pollution control, test and
analytical procedures have undergone modifications and
improvements over the years. The initial testing in California
and at the Federal level used a 7-mode 7-cycle test procedure.
During this type of testing, a vehicle is run through seven
driving conditions or modes such as low and high speed
acceleration. The resulting emission measurements are
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representative of the rate of emission during these particular
driving conditions, but do not measure total emissions.
In 1970, the Federal Government adopted a Constant Volume
Sample or CVS procedure during which the vehicle is run through
? test cycle designed to simulate urban driving. The
characteristics of the standard test drive were based on an
elaborate study of Los Angeles traffic patterns in 1965. All
emissions from ignition key-on after a 12-hour storage period
to the end of the test cycle are collected and analyzed. The
CVS procedures result in measurements which are considered
more representative of actual emissions from vehicles as used
in urban areas. However, the resulting numerical standards
are different from those revealed by earlier test procedures.
EPA has recently announced a further refinement in test
procedures to include both a cold start (after a 12-hour
storage) and a hot start (after a 10-minute wait) and the
computation of a weighted average as a basis for 1975 and
1976 numerical standards. These changes, as well as certain
minor modifications in analytical techniques, are intended
to make test results more representative of emissions from
in-use vehicles. The new test procedures are also expected
to be used in connection with the proposed 1973 emission standards,
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C. Significant EPA Actions
1) On January 30, 1971, the Environmental Protection Agency
published an advance notice of proposed rule-making concerning
its intention to promulgate controls or prohibitions on the addition
of alkyl lead to gasoline fuels for motor vehicles at the earliest
possible date. In accordance with the requirements of Section
211 of the Act, EPA is considering relevant, scientific, medical,
economic, and technological data prior to final rule-making
in this area. Systems designed to control NOX emissions to meet
standards applicable to 1973 model year cars may require that
a low lead gasoline be generally available in late 1972 and the
probable use of catalytic converters to achieve the 1975 HC-CO
standards makes it imperative that unleaded gasoline be generally
available by that time. These developments underscore the need
for implementing the President's request for a tax on lead
in gasoline to insure that unleaded gasoline will be competitively
priced.
2) On February 26, 1971, all domestic and foreign auto
manufacturers were requested by the Administrator to furnish
EPA with the following information:
1. A description of the basic techniques being explored as a
means of meeting the emission standards required under Section
202 (b) (1).
2. With respect tt> the techniques identified and described:
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a. An indication of the current state of development
and testing, including durability testing of each
one.
b. A summary of the emission data derived from any
such testing.
c. An assessment of the prospects for perfecting each
one to a point at which it could be used on production-
line motor vehicles.
d. A description of the major problems that remain to be
solved in order to perfect each type of unit.
e. An identification of all other companies participating
in the development and testing.
f. A summary of the resources in dollars and professional-
technical man years applied during calendar year 1970
and expected to be applied during 1971 to the
development and testing of the various units.
3) On April 7, 1971, a notice of proposed rule-making
was published concerning the requirement for the preparation of
State implementation plans necessary to achieve national
ambient air quality standards. Under Sections 109 and 110 of
the Act, EPA is required to publish national ambient air
quality standards and States are required to prepare specific
implementation documents detailing how they propose to attain
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the prescribed ambient standards. In this notice, attention
was called to the potential need to develop aftermarket
strategies to control motor vehicle emissions, which might
include vehicle inspection programs, mandatory maintenance,
and/or retrofit control systems for the existing auto population.
fhe technology for periodic inspection is being developed and
will be evaluated in terms of benefits, costs, and effectiveness.
4) On April 10. 1971. the Federal certification test
results for 1971 model year motor vehicles and engines were
published.
5) On April 30, 1971, national primary and secondary
ambient air quality standards were published as final rule-
making, including standards for hydrocarbons, carbon monoxide,
and oxides of nitrogen. These pollutants are associated with
motor vehicle emissions.
6) Also on April 30. 1971. the State of California was
granted waiver of Federal preemption for motor vehicle emission
standards more stringent than those currently in effect by
Federal regulation. These pertain to:
a. Auto emission standards and test procedures for the 1972
model year.
b. Auto assembly line standards and test procedures for the 1972
model year.
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3. Prohibition of the sale of automobiles that require
gasoline of research octane greater than 91 effective with
the 1973 model year.
4. Gasoline powered truck emission standards and test
procedures for the 1973 model year and more stringent
standards for the 1975 model year.
'j. Diesel powered truck emission standards and test procedures
for the 1973 model year and more stringent standards for
the 1975 model year.
The waiver was granted on the basis of testimony presented
at a hearing held in Los Angeles, California, on January 26 and
27, 1971, additional material provided prior to February 22,
1971, and other related information available to the Environmen-
tal Protection Agency. Additional waiver requests were denied
at that time but are under review within EPA.
The legal basis for granting this waiver is contained
in Section 209 of the statute which concerns Federal preemption
of State and local emission standards. However, the law also
permits EPA to issue waivers to California if, after public
hearing, the Administrator finds that State standards more
stringent than the Federal requirements are necessary to meet
compelling and extraordinary local conditions.
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7) On May 6 and 7. 1971. hearings were held in
Washington, D. C. to supplement the industry responses to
the Administrator's letter of February 26, 1971. Twenty-one
representatives of the automotive and related industries, of
the academic and scientific communities, and of public interest
groups and organizations presented statements and responded to
questions related to meeting the 1975-76 emission standards.
In his introductory comments, the Administrator stated:
"The law itself does not permit traditional
conceptions of satisfactory driving performance
to stand in the way of whatever changes in vehicle
design and power system are needed to control
emissions. The same is true with regard to vehicle
cost. This hearing is part of the continuing effort
by the Environmental Protection Agency to find out
just what sacrifices might be needed in cost, in
fuel economy, in power, in acceleration and in other
historic yardsticks of vehicle performance to produce
an automobile that we can live with as a people.
"The low emission car of the future may be a more
expensive car. It may not equal today's car in road
performance, but this is a price that may be
necessary if we are to have and preserve a healthy
environment for ourselves and our families,
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"As a consequence, we cannot and will not accept
anything less than a wide open research and
development effort to meet the actual requirements.
We will not, for example, find acceptable a
manufacturers decision not to explore innovative
designs or power systems on the grounds that a vehicle
so designed or so powered would be more costly or
would not meet traditional performance criteria. We
must develop and apply whatever technology is needed
to achieve the degree of emission control required by
the Act and we must be willing to accept any necessary
sacrifices in other areas of vehicle performance."
He further stated a second point concerning,
"The specific power conferred upon me by the Clean Air
Act to suspend the effective date of an emission
standard for one year. Exercise of this power is
carefully circumscribed by law. I am required to make
a determination relating to good faith and two
separate determinations concerning the technological
feasibility of meeting the statutory standards."
"I have given serious considerations to the proper
construction of the statutory provision for suspension,
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It is my present judgment that the required determinations
relating to technological feasibility do not permit me to
suspend an emission standard in favor of a single appli-
cant or a group of applicants if technical knowledge
exists, in the industry or elsewhere, which would enable
any member of the industry to mass produce a light-duty
vehicle in compliance with the Act."
"It is important that all of the implications of this
construction of the law be well understood at the
earliest possible time. It means that if any member of
the industry could meet the Act's deadlines for
compliance, all applications for extension will be denied.'
"Any other construction of the suspension provision would
be incompatible with the clear intent of the law to
require whatever changes in design or power systems are
needed to control emissions. Where some manufacturers
meet the statutory deadlines by making major changes
which substantially increase the cost of the vehicles or
which require major sacrifices in vehicle performance, I
do not believe that Congress intended to subject such
manufacturers to competition from cars produced by other
manufacturers who are required to meet a less stringent
standard."
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"As I read the law, the separate determination
concerning good faith becomes applicable where it
is not technologically possible for any member of the
industry to comply with the Act's requirements. In that
event, suspensions for one year would be granted only
to applicants who can establish that they made a good
faith effort to meet the statutory deadlines for com-
pliance. Here, on the separate issue of good faith, the
specific problems which may face a particular
manufacturer appear to be pertinent."
8) On May 11, 1971. the proposed definition of useful
life for vehicles and requirements for the inclusion of
maintenance instructions for emission control systems in
owner's manuals were published to implement Sections 202(d)
and 207 of the Act.
9) In May, 1971, three contracts were awarded to provide
prototype cars for government ter-ting and ova Nation under the
Federal Clean Car Incentive Program.
10) On June 18. 1971, the Low-Emission Vehicle Certifica-
tion Board held its initial meeting and approved procedural
regulations concerning preferential purchasing of low-emission
vehicles for use in government fleets. These activities
are prescribed in Section 212 of the Act.
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11) On June 29, 1971, the first Federal standards were
issued requiring control of oxides of nitrogen emissions and
prescribing measurement techniques for this pollutant
applicable to 1973 model light-duty motor vehicles.
12) On June 29, 1971, standards were promulgated to
prescribe the 1975 exhaust hydrocarbon and carbon monoxide
emission requirements,and 1976 oxides of nitrogen emission
requirements applicable to light-duty vehicles as required by
Sections 202(b)(1)(A) and 202(b)(1)(B). In addition,
modifications in test and analytical procedures were included
as described in Section B of this Chapter.
In addition, EPA has entered into an initial contract
with the National Academy of Sciences to study the
technological feasibility of meeting the 1975 and 1976
standards in accordance with the provisions of Section 202c of
the Act.
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CHAPTER 3: Related EPA Programs and Activities
A. Introduction
The Environmental Protection Agency has been assigned
responsibility for a number of programs and activities
designed to abate pollution emanating from motor vehicles.
Regulations establishing standards, testing procedures, and
enforcement practices have been developed and promulgated
to guide future actions. Staff and contract personnel from
the National Academy of Sciences are assessing the technological
feasibility of attaining the 1975 and 1976 standards established
in tne legislation. EPA is expanding its capability to monitor
industry progress whicn is primarily focused upon add-on
devices to clean up the internal comoustion engine. Demon-
stration programs have been initiated concerning the
feasibility of low-emission vehicles. EPA is also directing
a research and development program for alternative power
systems.
B. Estab1ishing Standards
The Clean Air Act as amended establishes specific
emission requirements for hydrocarbons, carbon monoxide, and
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oxides of nitrogen for 1975 and 1976. However, EPA was
required to convert these parameters into specific numerical
standards related to 1970 and 1971 emission levels. This
work has been completed, and the standards for 1975 and
1976 have been published.
In addition, EPA also has responsibility under Section
202(a)(l) of the Act for promulgating emission standards for
other exhaust pollutants if they are found to endanger public
health and welfare. Due consideration must be given to the
availability of appropriate control technology and the cost
of compliance. These responsibilities carry EPA into analysis
of exhaust materials, research concerning health and welfare
impacts of pollutants, assessment of available control tech-
nology and studies of the economic impact of alternative
abatement strategies.
C. Testing and Enforcement
The enabling legislation assigns EPA responsibility for
testing, certification, and enforcement activities concerning
emission controls for new motor vehicles and engines. At
present these programs generally follow the procedures outlined
below: A quantifiable emission standard is promulgated
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to be met by a set deadline. Manufacturers develop and
test prototype vehicles, with some confirmatory testing by
EPA. If the prototype design is found to comply with the
standard, the group of vehicles represented by that unit is
certified for production and sale. In-use vehicles are later
t.ested to determine whether production vehicles continue to
meet the standards.
EPA's testing and enforcement procedures require the
certification of manufacturers' vehicle and engine product
lines based on the satisfactory testing of prototype
designs. In formal application for certification, the
manufacturer is required to delineate pertinent mechanical
characteristics of the vehicles or engines and emission
control systems, and the projected sales of each configuration,
This information provides the basis for EPA selection of
configurations to be tested for establishing eligibility
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for certification. The actual testing program involves two
groups of vehicles or engines. One group is tested to
determine emission levels after engine break-in. The second
group consists of vehicles or engines which are operated for
for extended periods with limited maintenance
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to simulate the rate of emissions degradation with normal
usage. The certificability of a group or engine family is
established if the emission value of each engine tested,
adjusted by the appropriate deterioration factor, is in
compliance with the standards.
Surveillance testing of vehicles in routine service
has shown that production vehicles in use do not consistently
•display the low emission levels indicated in prototype
certification testing. Procedures for assembly line testing
are under development but they require solutions to serious
problems. High volume testing dictates the need for quick
test procedures which can be consistently related to the
certification test results. Such procedures should ideally
provide diagnostic information so that appropriate repairs
can be made at minimum expense and with minimum loss of
time. An effective quick test procedure could also be
useful in expanding the present surveillance programs to
determine when manufacturers should institute recall programs,
An extensive program is being conducted by EPA to identify
appropriate equipment and procedures.
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To implement Section 207, manufacturers of nev motor
vehicles and engines will be required to warrant to the
ultimate purchaser that the vehicle or engine is designed,
built, and equipped to conform with applicable
emission standards, and is free from defects in materials
and workmanship which might result in failure to conform to
appropriate regulations during its useful life. Sur-
veillance studies will be strengthened and regulations will
be promulgated requiring manufacturers to recall vehicles
which are found to be out of conformity with standards
during the warranty period.
The testing of heavy-duty vehicles entails the ap-
lication of substantially different procedures than those
associated with light-duty vehicles. Heavy-duty engines,
both gasoline-fueled and diesel have a broad range of
uses in vehicles larger than 6000 pounds. Present pro-
cedures, therefore, involve engine testing as opposed to
vehicle testing. EPA is currently reevaluating the
heavy-duty testing procedures with the objective of as-
suring that they reflect, as much as possible, the emissions
from such vehicles in actual use.
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Another important feature of EPA's testing program
concerns the verification of new control devices developed
by non-automobile manufacturers. Section 206 provides for
the testing or any emission control system incorporated in
a motor vehicle or motor vehicle engine submitted to the
Administrator by any person. If it is determined that the
vehicle or engine conforms to appropriate standards, the
Administrator shall issue a verification of compliance with
emission standards for the system. The manufacturers and
the National Academy of Sciences shall be informed of these
results which shall also be made available to the public.
Hopefully these provisions will accelerate the pace of
development of new emission control devices.
D. Monitoring Technological Developments
In order to carry out EPA responsibilities concerning
the 1975 and 1976 emission standards for light-duty vehicles,
we are expanding our capability to monitor the development
of appropriate control technology both within and without
the auto industry. As described in Chapter 2 the Administrator
has requested specific information from the auto manufacturers
and has held public hearings on these subjects. The results
of our initial contacts are reflected in Chapter 5.
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E. National Academy of Sciences Contract
Section 202(c)(l) of the Act directs that the Administrator
"enter into appropriate arrangements with the National
Academy of Sciences to conduct a comprehensive study and
investigation of the technological feasibility of meeting
the emission standards required to be prescribed by the
Administrator" (for 1975 and 1976 light-duty motor vehicles).
In addition* the Administrator is directed to request the
National Academy of Sciences to submit semi-annual reports
on its progress to the Administrator and to Congress begin-
ning on July 1, 1971.
Shortly after the passage of the Act, EPA contacted
the staff of the Academy concerning this work. A preliminary
contract was awarded to the Academy to allow them to assemble
the necessary resources, and develop specific plans and budgets
for carrying out the work. The involvement of the National
Academy of Sciences will provide the Congress and the Admin-
istrator with an independent assessment of technological
feasibility of meeting the 1975 and 1976 standards.
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F. Regulation of Fuel Content
The fuel additive which has received most attention
related to auto emissions is lead. It has been well docu-
mented that catalytic converters, which are among the
devices being developed to remove carbon monoxide, hydro-
carbons, and nitrogen oxides from vehicle exhaust, deteriorate
rapidly when exposed to fuels containing lead compounds.
Lead additives have also been shown by several investigators
to contribute to fouling of exhaust gas recirculation systems
used for nitrogen oxides control.
As directed in Chapter 4, the health effects of
lead emissions are now under serious review. Studies are
also being sponsored by EPA to evaluate the economic impact
of curtailing or eliminating the use of lead in gasoline.
A comprehensive report concerning this matter is expected
later this year which will serve as a basis for further
discussion and eventual rulemaking.
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G. Alternative Power System
In order to meet the 1975-76 standards, the automobile
industry is concentrating its efforts on modifications of
the conventional internal combustion engine. There is serious
question, however, about the ability of the conventional engine
to meet long term health and welfare needs of the nation as
now perceived. Accordingly, the Environmental Protection
Agency has embarked on a program of federally sponsored re-
search and development of alternative engine systems which
are inherently cleaner than the conventional engine. This
development activity is embodied in the Advanced Automotive
Power System Program (AAPSP).
Five types of power systems initially were part of the
program when it began in July of 1970. These include Rankine
cycle, the gas turbine, heat engine/electric hybrid, heat
engine/flywheel hybrid, and all-electric. Two additional
systems, the stratified charge engine and the advanced design
diesel engine, have been added to the program. Limited
privately sponsored research has been underway for some time
on all of those systems.
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Each candidate system was at a different stage of
development when the program began and, depending on tech-
nical developments, may enter the hardware phase at a
different time. The first 18-month phase of the program
is intended to be a period of evaluation wherein complete
systems are designed, critical components bench tested, and
decisions made on whether to proceed to first generation
system hardware.
In the Rankine Cycle Engine, there is an external
combustor and an enclosed working fluid which is heated, ex-
panded to do work, then condensed into a liquid, with the
fluid being continuously recycled. Three types of Rankine
systems are presently in the design and component test phase,
Two systems use organic working fluids one with a recipro-
cating expander, the other with a turbine expander. The
third Rankine system is the steam engine. The technical
problems confronting the successful development of the
Rankine cycle system are understood and are being studied.
Major problems appear in the inefficiency of components, and
complexity of the control systems. Parallel research and
development of components for all three types of engines
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is currently underway. The first prototype engines are
expected to be available for testing in 1972.
More work has been conducted by the domestic auto
manufacturers on the gas turbine engine than on any other
candidate. EPA sponsored research efforts are being focused
on solving specific problems which have made the gas turbine
unattractive for use in cars. These problems include the
need for reducing the nitrogen oxide emissions in the exhaust,
developing manufacturing techniques for mass producing turbines
inexpensively, and increasing system reliability. As
solutions to-these problems become available, it is anticipated
that industry will apply them to their own turbine designs.
The hybrid engine candidates include the heat engine/
electric and the heat engine/flywheel. The heat engine/
electric hybrid consists of a small size low-powered engine
(80-100 hp) and an array of batteries. The hybrid system is
designed to extract power from the engine alone, or from
both engine and battery at the same time. The basic system
is compatible with either a conventional internal combustion
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engine or a small gas turbine. In either configuration the
system operates best by running the heat engine at a constant
speed with additional power for acceleration supplied from
the battery system.
This hybrid concept offers potential advantages. The
engine speed range is relatively small with an attendant
ease of control of exhaust emissions under such conditions.
Good road performance for a standard size American automobile
can be obtained with a relatively small and inexpensive heat
engine. The basic problems of this system are its relative
complexity, higher cost, and the greater space required for the two
sources. Development of improved lead-acid batteries to
accommodate the rapid charge-discharge characteristics needed
for this hybrid mode of operation is now underway.
The heat engine/flywheel system would function in a
manner similar to the heat engine/electric with the battery
replaced by a mechanical storage device, a spinning flywheel.
Research has progressed from the analysis of practical fly-
wheel materials to the design and fabrication of specific
flywheels for cars.
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The all-electric car engine development has been
underway for more than a year at Argonne National Laboratories,
It is anticipated that "proof-of-principle" for a high
temperature lithium-sulfur system will be demonstrated
within the next 8 months. Once proof-of-principle has been
achieved, the study will move into a development phase, first
with si goal of a 2 kilowatt (kw) battery, then a 5 kw battery
and then a 20 kw battery system. Development of the all-
electric system will not be completed early enough to meet
1975 standards because the project is still in the fundamental
research stage. Moreover, an environmental cost/benefit
analysis is yet to be undertaken which would indicate whether
there would be a net gain from the environmental viewpoint
given the added burdens such a system might place on electric
power generation requirements. However, such a low emission
vehicle might be highly desirable for conjested urban areas.
The stratified charge engine is a gasoline-fueled
internal combustion engine with many hardware characteristics
of the conventional engine. Differences appear mainly in
the combustion chamber design and the use of fuel injection.
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Much of the initial work on this engine was sponsored by
the U.S. Army Tank-Automotive Command. The measured ex-
haust emission levels for an experimental stratified charge
engine installed in a small military vehicle and employing
a catalytic muffler are below the standards for hydrocar'. jns
and carbon monoxide set for 1975. Further work must be con-
ducted to reduce the nitrogen oxide emissions to attain the
1976 standards. Several generations of development have been
funded by the Army with some assistance by HEW. EEA's work
on this engine has emphasized the reduction of nitrogen
oxide emissions. Testing of this system in a fleet of vehicles
is now being contemplated. However, there are many problems
to overcome to convert experimental engines into mass
produced vehicles with similar emission characteristics.
The diesel enqine is not commonly used in American
made automobiles because it is heavier and more expensive
than the conventional automobile engine. Emphasis is being
directed toward the development of a low compression diesel
with high-swirl injection and a modified prechamber design.
Exhaust emission levels for hydrocarbons and carbon monoxide
lower than the 1975 standards have been shown for this type
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of engine without the need for a catalytic converter. The
measured nitrogen oxide levels of the first generation
engine are relatively low although above the 1976 standards.
Studies are concentrating on nitrogen oxides reduction and
on performance, durability ind driveability testing.
H. Federal Clean Car Incentive Program
The Federal Clean Car Incentive Program (FCCIP) is
designed to foster private development of new types of
low emission vehicles related to the 1975 and 1976 emission
standards. In the first stage of the program the developer
leases to the Government a candidate prototype vehicle
which is subjected to rigorous evaluation. After success-
fully passing stringent emissions and performance testing
on the leased prototype car, 10 additional vehicles may
be purchased for more comprehensive testing. The govern-
ment may later buy up to 100 vehicles for further evaluation.
If the low emission levels are maintained and road per-
formance is found to be satisfactory, the car is then
eligible for certification as a low-pollution vehicle
under the program described in the next section of this
report.
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This program began in January* 1971, with approximately
20 initial proposals from industry. Ten different vehicle
systems have been accepted into the program. In May of this
year three contracts were approved to provide prototype cars
for testing. The Incentive Program is expected to provide
valuable information about the feasibility of reaching the
1975-76 emission standards.
I. Low-Emission Vehicles Purchase Program
Section 212 of the Act provides for the creation of a Low-
Emission Vehicle Certification Board (LEVCB). EPA initially
certifies vehicles which discharge significantly less pol-
lutants than required by current Federal regulations. The
LEVCB identifies the class of vehicle for which the selected
cars are considered suitable substitutes taking into consider-
ation factors such as performance and cost of maintenance.
Certified vehicles may be purchased for use in government
fleets at premiums of up to 100% over the prices normally paid
by the government for equivalent vehicles. The non-statutory
members of the Board have been named by the President and its
first meeting was held on Jufle 18, 1971. At that time the
board adopted initial procedural regulations.
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CHAPTER 4: Health and Welfare Effects
A. Emission Levels and Ambient Air Onalil-y
Motor vehicle emissions are important sources of air
pollutants especially in our congested urban areas. The
following figures indicate EPA's estimate of the relative
contribution of vehicle emissions of HC, CO, and NOX-
% of National Emissions in 1969
Source CO HC NOX
Motor Vehicles 64.7 45.7 36.6
Other forms of
transportation 9.0 7.2 10.5
Fuel Combustion
in stationary
sources 1.2 2.4 42.0
Industrial Processes 7.9 14.7 0.8
Solid Waste Disposal 5.2 5.3 1.7
Miscellaneous 12.0 24.7 8.4
100.0 100.0 100.0
In addition, emissions of HC and NOX from motor vehicles
and other sources undergo complex chemical reactions in the
atmosphere and contribute to the formation of photochemical
oxidants associated with urban smog.
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While the proportions indicated above hold true nationally,
the relative contributions of vehicle emissions to ambient
air quality varies among communities. These variations result
from differences in geography, meteorological conditions,
traffic patterns, and the size and location of other sources
of the same pollutants. Thus in discussing health and
welfare impacts the key factors are ambient air concentrations
resulting from emissions fron all sources, rather than
emissions from any particular source.
In accordance with Section 109 of the Clean Air Act,
EPA has published national primary and secondary ambient air
quality standards for a variety of air pollutants. Primary
standards define levels of air quality which the Administrator
judges to be necessary, with an adequate margin of safety,
to protect public health. Secondary standards reflect
concentrations judged necessary to protect public welfare
from any known or anticipated adverse effects. Of interest
to a discussion of motor vehicle emissions are the ambient
air quality standards for photochemical oxidants, hydrocarbons,
nitrogen dioxide, and carbon monoxide which are shown in
Table 1.
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Table 1
NATIONAL PRIMARY AND SECONDARY AMBIENT AIR QUALITY STANDARDS
For Motor Vehicle Related Pollutants
(Concentrations not to be exceeded more than once per year)
Pollutant
Concentration Limit
Micrograms Per
Cubic Meter
Parts Per
Million
Averaging Time
Photochemical
Oxidants
Hydrocarbons
(Methane free)
Nitrogen
Dioxide
160
160
0.8
0.24
1 hour
3 hours
Carbon
Monoxide
10,000
40,000
9
35
8 hours
1 hour
For the above pollutants, adverse welfare effects have not been
observed to occur at levels below those judged necessary to
protect the public health. Accordingly, the secondary standard
has been set at the same level. Pursuant to the Act, primary
ambient air quality standards must generally be achieved by
June 1, 1975.
Standards for short-term exposure rates for nitrogen dioxide
have not been promulgated. EPA has established safe annual
exposure rates of 100 ug/m3 or 0.05 p.p.m.
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Related to the establishment of national ambient air
quality standards are the provisions of Section 110 of the
legislation, which require that States prepare implementation
plans indicating how they will attain the national ambient
standards within their boundaries by 1975. These documents,
which are to be submitted to EPA by January 30, 1972, will
indicate the relative contribution of motor vehicle emissions
to ambient air quality for communities in many parts of the
Nation. They are also expected to include a variety of
abatement strategies and contribute greatly to our under-
standing of the significance of motor vehicle emissions
control.
B. Photochemical Oxidants, Hydrocarbons, Carbon Monoxide,
and Oxides of Nitrogen
Detailed discussions of the effects of photochemical
oxidants, hydrocarbons, nitrogen oxides, and carbon monoxide
may be found in their respective Air Quality Criteria
Documents. The following is a summary of the more important
effects of these pollutants in ambient air masses coming
from all sources and not just motor vehicles.
Photochemical oxidants result from a complex series
of atmospheric reactions initiated by sunlight. When
reactive organic substances and nitrogen oxides accumulate
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in the atmosphere and are exposed to the ultraviolet
components of sunlight, the formation of new compounds,
including ozone and peroxyacyl nitrates, takes place.
Photochemical oxidants may adversely affect vegetation,
human health, animals, and certain man-made materials. They
can cause injury to many important species of plants such as
beans, tobacco, petunias, peanuts, and pine trees. Injury
to sensitive species has occurred after exposure of 4 hours
to 0.05 ppm of photochemical oxidants. In southern California
hundreds of acres of pondercsa pine forest have been affected
by photochemical oxidants.
The principal human effect associated with photochemical
oxidants include impairment of athletic performance and an
increase in attacks among asthmatics, the latter effect
having been observed when oxidant levels reached 0.15 ppm
for one hour. Although eye irritation has been associated
with oxidant levels of 0.10 ppm in Southern California, it
has not been shown conclusively that any particular species
of photochemical oxidants is responsible.
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Rubber, fabrics, and dyes are particularly sensitive
to photochemical oxidants as evidenced by rubber cracking,
reduced strength in cellulose fabrics, and the fading of
certain dyes after exposure.
Hydrocarbons represent the major class of reactive
organic matter in the atmosphere that is responsible for
photochemical smog. Through their reaction intermediates
and photochemical oxidation products, they are directly
responsible for the eye irritation associated with
photochemical smog and much of the characteristic vegetation
damage. Hydrocarbon oxidation products are also believed
to be important contributors to the atmospheric aerosols
responsible for the reduced visibility associated with
photochemical smog. In addition, ethylene, a specific
hydrocarbon, is directly responsible for certain forms of
plant injury—orchids are especially sensitive.
The presence of nitrogen oxides in the atmosphere
is essential to the photo-oxidation of hydrocarbons and the
development of photochemical oxidants. Sufficiently reduced
level? of either NOX or HC alone in the air tend to alleviate
the formation of photochemical oxidants, but the exact
relationships are extremely complex.
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Nitrogen dioxide, a type of oxide of nitrogen, is also a
specific air pollutant associated with increased incidences
of acute bronchitis in infants and school children and
acute respiratory disease in the entire faimily group.
Nitrogen dioxide has also been associated with damage to
vegetation and corrosion of electronic components. Increases
in the incidence of respiratory disease were associated with
nitrogen dioxide levels ranging from 0.06 ppm to 0.08 ppm
over a 6-month period.
Carbon monoxide is well known for its poisonous effects
at high concentrations. It is absorbed through the lungs
and reacts primarily with the hemoglobin of red blood
cells. As an air pollutant, carbon monoxide represents a
potential danger to human health and safety. It decreases
the oxygen carrying capacity of the blood and reduces the
availability of oxygen-transported to vital tissues by the
blood. Carbon monoxide concentrations of 10 ppm produce
blood carboxyhemoglobin levels of 2% in non-smokers. This
carboxyhemoglobin level has been associated with impaired
time interval discrimination.
Carbon monoxide concentrations of 30 ppm for 8 to 12
hours have been associated with impaired psychomotor performance
and reduced visual acuity in normal subjects and with
increased physiological stress to patients with heart disease.
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C. Other Pollutants
1. Lead
Evaluations of available evidence are presently underway
to determine the specific health effects of lead particulate
matter emanating from auto emissions. These evaluations
should be completed in the near future. It is already known
that lead is a biologically nonessential metallic element
which is clearly toxic under conditions of prolonged and
excessive exposure (e.g., ingestion of paint containing lead).
Furthermore, lead accumulates in persons exposed to high
atmospheric concentrations. Lead is absorbed primarily
through the gastrointestinal and respiratory tracts.
As noted in Chapter 3, in addition to health effects,
lead in gasoline has been found to greatly reduce the
effectiveness of catalysts and therefore the availability
of unleaded gasoline is needed if these devices are to be
used on production vehicles.
Since about 96 percent of the lead particulate matter
found in the atmosphere results from gasoline-fueled engines,
the reduction or elimination of lead from gasoline should
significantly reduce the incidence of lead particulate matter
in the future.
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2. Other Substances
The significance of the relationship between auto emission:;
of the materials listed below and the health or welfare dangers
has not been established. Medical and biological investigations
of the following items are underway:
(1) Particulate materials—both organic and inorganic.
(2) Aldehydes and other carbonyl compounds.
(3) Nitrogen compounds other than nitrogen oxides,
such as ammonia.
(4) Miscellaneous organic materials, such as polynuclear
aromatic hydrocarbons.
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CHAPTER 5: Industry Progress
A. Basic Technology
The gasoline-fueled internal combustion engine is the
best understood and most reliable propulsion system currently
available. The auto industry maintains that it is also the
only prospect for mass production in 1975-76. Unfortunately,
it is also an inherently high-emission propulsion system. These
high emissions are caused, to a major degree by the fuel
itself and relate to the difficulty in supplying thermody-
namically ideal air and fuel charges to the cylinders and
bringing about complete combustion over the full range of
vehicle operating requirements.
The problem is maximized at low engine start-up temper-
atures and when the humidity and temperature of the air supply
vary widely. Additionally, variability in fuel density and
viscosity are factors which inhibit precise metering of the
fuel. Gasoline in the liquid state will not burn and thus
the higher boiling point hydrocarbons do not vaporize and
burn when the engine is cold. Cold engine starts require
extra amounts of gasoline to produce enough vaporized fuel to
provide a combustible mixture at the sparkplug. The excess
non-vaporized portions then pass through the engine unturned .
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The problem is reduced as the volatility of the gasoline is
increased and the boiling range reduced. The importance of
the fuel volatility factor is dramatized by the emission
performance of the internal combustion engines when operated
on natural gas or liquified petroleum gas (LPG). Typically,
such changes in fuels result in lover emissions of HC and CO.
While efforts aimed at leaner air-fuel mixtures tend to
reduce hydrocarbons and carbon monoxide, they tend to increase
emissions of nitrogen oxides. This occurs because improved
combustion results in higher temperatures which in turn promote
the union of nitrogen and oxygen. Efforts to control nitrogen
oxides to high levels within the engine tend to negate the
improvement gained in HC and CO control. Thus NOx control
will probably require other measures to reduce peak combustion
chamber temperatures and/or the addition of an external control
system.
B. Typical Controj^ Concepts and Devices
Engine modificationsdesigned to reduce emissions during
the combustion process represent the principal approach used
for compliance with motor vehicle exhaust emission standards
now in effect. Such modifications, refined to promote even
more efficient combustion, will continue to be a fundamental
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part of the systems approach leading to compliance with future
standards. However, add-on devices such as thermal reactors
and catalytic converters will most likely be required to
complete the system.
Modification in gasoline composition, such as the elimination
of lead and, possibly, changes in volatility characteristics,
may also be required in order to facilitate the use of certain
control techniques and optimize the potential of others. A
review of the emission control techniques, components and
concepts, known to be under development by industry for gasoline
fueled motor vehicle follows:
1. Modification of Combustion Chamber Design
A major source of hydrocarbon emissions from auto-
mobiles is unreacted fuel-air mixtures expelled through
the tailpipe. This occurs primarily because the very
thin layer of gaseous mixture which makes contact with
the relatively cool combustion chamber surfaces does not
burn. By modifying the combustion chamber design to
reduce the surface-to-volume ratio and by minimizing
crevices, more nearly complete combustion of the full
cylinder charge is promoted.
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2. Modification of Induction System
Carbon monoxide in the exhaust results from insuf-
ficient oxygen in the fuel-air mixture and consequent
incomplete combustion. Incomplete combustion is also an
important source of hydrocarbons. Leaner air-fuel mixtures
to assure more complete combustion can be accomplished by
converting more of the liquid gasoline into the vapor
form and by providing for improved fuel-air mixing and
distribution among the cylinders. Air-fuel induction
systems can be adapted to provide heated intake air for
more uniform carburetor inlet temperatures thus allowing
leaner fuel-air mixtures to be used. Air temperature can
be maintained by a thermostatically controlled mixing
valve in the air cleaner. Intake manifold heating tends
to provide more uniform fuel distribution. Intake ports can
also be re-designed to give improved induction turbulence
and mixing. More uniform distribution of the fuel-air
mixture to the cylinders can likewise be accomplished through
design changes. Unfortunately, modification of induction
systems which improve combustion and reduce HC and CO
emissions also raise temperatures and worsen NOx control.
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3. Carburetor Modifications
The carburetor is a key element in effective emission
control by virtue of its role in metering the fuel in
proper proportion to inlet air. Precise fuel metering, in
accordance with changing engine requirements, makes possible
operation with lean air-fuel mixtures. Carburetors can be
designed with stronger fuel metering signals end closer
calibration tolerances to assure better fuel mixing pre-
paration. Fuel injection systems can provide more accurate
metering and deliver fuel under pressure for maximum
atomization. Electronic fuel metering could also allow for
altitude compensation and more precise mixture control.
4. Choke Modifications
Gasoline in liquid form does not burn. Consequently,
when an engine is started cold, an extra amount of gasoline
is needed in order to obtain enough vaporized hydrocarbons
to mix with air and provide a combustible mixture at the
sparkplug. The function of the carburetor choke is to
supply the added fuel. However, the unvaporized hydrocarbons
pass through the engine unburned. By tailoring choke action
to car requirements, enrichment during starting and warm-up
can be made compatible with satisfactory driveability over
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a wide temperature range. Modification of the fuel to
achieve greater vaporization could obviate the need for
the choke or drastically reduce its periods of actuation.
5. Ignition System Modifications
Ignition systems optimized to initiate combustion in
accordance with engine operation and emission control
requirements, support improvements in fuel metering and
mixture control. Spark retardation can be employed to
reduce emissions of hydrocarbons and nitrogen oxides.
Electronic ignition systems have been developed which will
improve control of spark timing at all engine operating
conditions greatly facilitate adjustments of spark timing on
vehicles in consumer use, and improve system reliability.
Retarding ignition timing results in more fuel being
burned during the exhaust phase of the combustion cycle.
Accordingly, some loss in power and fuel economy results
and demands on the engine cooling system are increased.
6. Lower Compression Ratio
The use of high compression ratios improves engine
efficiency and results in more power output for a given
amount of fuel. Combustion temperatures are high, however,
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causing high emission of nitrogen oxides. The
octane requirements of high compression ratio engines
are high, necessitating the use of lead or expensive
fuel modification. The presence of lead in gasoline
severely limits the effectiveness of catalytic converters
and reduces the life of other emission control system
components. For these reasons, compression ratios of
new cars are being redured to curtail NOx emissions
and promote the removal of lead additives.
7. Air Injection
Exhaust port air injection is one of the oldest concepts
used for controlling motor vehicle exhaust emissions.
Increased oxidation of hydrocarbons and carbon monoxide
is achieved by pumping air into the exhaust ports and
manifold. Major revisions to the cylinder head and exhaust
manifold are required. Since NOx control during
the combustion process has tended to increase HC and CO
emissions, interest in exhaust port air injection is
reviving. Air injection pumps are also helpful
for effective operation of catal^ic converters
and thermal reactors.
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8. Exhaust Gas Recirculation
Recirculation of a portion of the exhaust gas into
the air-fuel mixture causes a reduction in the peak
combustion temperature and a reduction in the formation of
oxides of nitrogen. Dilution of the fuel charge with
inert gases has the secondary effect of reducing engine
octane requirements, but with some loss in power. Extreme
dilution causes misfiring and deterioration in driveability.
This can be compensated for by increased throttle openings
and providing richer carburetion mixtures, but with some
loss of fuel economy. Improved systems provide for
proportioning the recirculated exhaust gas to the air flow
demanded by the engine. Sensitive induction system
components can be corroded and plugged by acid condensate and
dirt in the recycled exhaust. The removal of lead and
associated scavengers from gasoline is expected to moderate
these problems.
9. Thermal Reactors
A thermal reactor functions as a combustion chamber
outside the engine and normally appears in the form of an
oversized exhaust manifold. Thermal reactors receive the
hot exhaust gas from the engine, retaining as much heat as
possible with insulation. Additional heat is generated by
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oxidation of carbon monoxide in the exhaust gases. High
carbon monoxide concentrations are obtained by operating
the engine with rich fuel mixtures. Such reactors are
known as "rich thermal reactors." Supplementary air is
required and it is necessary to create appropriate mixing
and provide adequate residence time for the combustibles
present to react with the oxygen. When designed for
rich fuel-air mixtures to promote NOX control, there is a
substantial fuel penalty. In a "lean thermal reactor"
system the carburetion is set lean so that the exhaust
is inherently oxidizing and a secondary air pump is not
required. Emissions are generally higher than from "rich"
reactors.
Because of the extremely high temperatures that can
be reached, the selection of suitable materials to give
satisfactory durability is a major challenge. Special
protective systems will be needed to prevent overheating
vvhich could damage the engine or create a general
safety hazard for the vehicle occupants.
10. Afterburner
The afterburner is designed to oxidize unburned
hydrocarbons and carbon monoxide in the exhaust gas.
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It includes a precoihbustion chamber in which secondary
air and fuel are sparkignited to provide thermal energy
for the associated reaction chamber. Over-temperature
problems present a serious handicap to its use.
11. Catalytic Converters
Catalytic converters are devices designed to
receive exhaust gases and foster chemical changes associated
with reducing levels of undesired pollutants.
The catalyst bed generally consists of an inert support
material on which the active material is deposited in a
thin layer. Alumina is the most common support whereas
platinum, or platinum group metals, and transition metal
oxides are the most common active materials. Catalysis
may be used for oxidizing the hydrocarbons and carbon
monoxide or reducing nitric oxide. The basic construction
of reducing catalysts is similar to that for oxidizing
catalysts. Reasonable effectiveness can be obtained for
both reactions with identical catalysts under ideal
conditions.
The catalytic converter is a relatively low-temperature
device and need not be located in the engine compartment
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with attendant space problems. Under body modifications
may be required, however, for heat insulation and adequate
ground clearance. It has a high heat capacity, requiring
a relatively long time to reach activation temperature,
but by the same token, it remains warm longer. A catalyst
and thermal reactor combination represents an attractive
system for controlling vehicle emissions. The thermal
reactor increases the exhaust gas and catalyst temperatures
and provides improved control during cold-start and warm-
up. Deterioration tends to occur as a result of cyclic
exposure to a high temperature environment* AS with
thermal reactors, fail-safe over-temperature controls
are required to prevent permanent damage resulting
unit or engine malfunction.
Oxidizing and reducing catalysts may be used in
combination but some mixture enrichment is needed to provide
the necessary reducing atmosphere in the reducing stage, and
supplemental air may be required for the oxidation stage.
Warm-up problems in the second stage are accentuated in
"dual catalytic converters." Good driveability and
minimal economy loss is possible with this concept.
However, reducing • -analysts with good endurance are
not yet available.
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C. Industry Concerns
Various industry representatives have expressed a
number of concerns about the prospect of meeting the 1975
and 1976 standards. While no one speaks for "the industry,"
there is enough commonality in content to identify a number
of major concerns shared by many of the manufacturers. It
has been asserted that the proposed standards cannot be attained
with available techro)ogy, would be far too expensive compared to
their effectiveness on axr quality and include deadlines that pro-
vide the industry with insufficient lead time. A number of
manufacturers have also expressed concern over increases in
costs and reductions in fuel economy and driveability after
modification to meet the 1975 and 1976 standards.
Various manufacturers have pointed out that t'.ie law
requires them to solve two very different technical problems
almost simultaneously. Hydrocarbon and carbon monoxide controls
needed for the 1975 standards dictate more complete combustion
in an oxidation atmosphere while controlling oxides of
nitrogen necessitates lower combustion temperatures and/or
a reduction atmosphere to convert these emission to nitrogen
and oxygen gases.
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A number of officials of both domestic and foreign
producers indicated that achieving the 1976 NOX standards
takes them beyond existing knowledge and will require some
technological breakthrough.
D. Exchange of Technical Information
Several manufacturers have complained about present
limitations on exchange of technical information concerning
vehicle emission control. These problems relate to the
civil antitrust action brought by the Department of Justice
in early 1969. The Government's complaint alleged that the
Automobile Manufacturers Association and the four major United
States manufacturers of motor vehicles, conspired to eliminate
competition among themselves in the development and installation
of motor vehicle air pollution control equipment. The
Government charged specifically that the defendants had agreed
to restrict public knowledge of research and development efforts
related to control of motor vehicle emissions, that the defendants
had delayed installation of control equipment, and that the
defendants had deliberately misinformed California regulatory
officials about the technical feasibility of reducing motor
vehicle emissions. On September 11, 1969, the defendants,
without admitting the truth of these allegations, entered into
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a consent decree which, among other things, prohibits each
defendant from agreeing with any other defendant, or with any
manufacturer of motor vehicles, to exchange unpublished technical
information for developing, improving or lowering the cost of
motor vehicle air pollution control equipment.
The consent decree expressly permits the defendants to
continue to exchange "basic research," as distinguished from
"applied research," and defines "basic research" to include
"theories of control of motor vehicle emissions..., "as well
as information pertinent to gaining a fuller knowledge or
understanding of the presence, nature, amount, causes, sources,
(or) effects... of motor vehicle emissions in the atmosphere."
The decree also permits the defendants to exchange information
that relates primarily to the "testing or measurement" of control
equipment and information that results from testing or measuring
"advanced stage" production prototypes. In addition, the decree
expressly permits the defendants to exchange information that
is made public through disclosure to news media or at meetings
where persons other than employees of motor vehicles manufacturers
are permitted to be present.
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The decree contains other provisions which specifically allow
the defendants to purchase from each other or from other
motor vehicle manufacturers "specific commercial products*"
"specific existing patent rights," and "specific existing..."
information or "engineering services" related to vehicle emission
control. Finally, the decree does not prohibit any defendent
from entering into or performing an agreement to which the
Department of Justice consents in writing.
A number of manufacturers of motor vehicles, including
most foreign manufacturers who sell motor vehicles in the
United States, contend that progress in emission control
technology is best achieved through unrestricted information
sharing. The smallest of the major United States manufacturers
claims that exchange of technical information is essential
to permit it to design engine systems that are compatible with
components that it must continue to purchase from other
manufacturers. In general, the smaller manufacturers contend
that their resources are inadequate to support an independent
research and development program which encompasses more than
a few areas of technological promise. They contend that only
the large vehicle manufacturers are able to seek answers
simultaneously to all of the interdependent engineering and
scientific challenges that are encountered in attempting
to mass produce vehicles that perform adequately and meet
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statutory emission standards.
While industry-wide research programs have been effectively
deterred by restrictions imposed on the major United States
manufacturers through the consent decree, the Department of
Justice has approved certain limited arrangements involving
specific research projects in which participation from related
industries is regarded as particularly important or involving
vehicle manufacturers who must purchase essential engine
components from other manufacturers. Pursuant to the decree,
the Department has consented to annual renewals of an inter-
industry research program which includes the Ford Motor Company,
certain foreign vehicle manufacturers, and a group of oil
companies.
The "Inter-Industry Emission Control Project" is specifically
limited to five or six defined research topics, and it is
understood that the vehicle manufacturers participating in the
project undertake substantial research and development activity
independent of the project. Foreign particpants are: Fiat,
S.P.A., Mitsubishi Heavy Industries. Ltd., Nissan Motor Company,
and Toyo Kogyo Company, Ltd. In addition, Volkswagenwerk A.G.
and Toyoto Motor Company, Ltd., have more recently purchased
rights of access to the project's technical work. However, these
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two additional foreign manufacturers are not full participants
in that they do not themselves provide the other project
members with technical information. The Justice Department
has also permitted American Motors to purchase certain
emission control engineering services from General Motors.
In general, the Environmental Protection Agency agrees with
the Department of Justice that technological progress in auto-
mobile emission control is best assured through primary reliance
on competition and independence in research and development
efforts conducted by manufacturers. At the same time, it
must be recognized that the emission reductions required by
law present a technological challenge that may severely strain
the resources of smaller manufacturers and may raise special
problems in the case of manufacturers who must continue to
purchase major engine components from other manufacturers.
It is also possible that a vehicle emission control
system or device could be independently discovered which,
if not generally known to members of the industry in time to
make necessary modifications in production facilities, could
radically affect existing competitive relationships in the
industry and could significantly reduce the number of independent
manufacturers. The possibility that severe competitive dislocation
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could result from independent research and development activity
is a matter of major concern. The compulsory licensing provisions
contained in Section 308 of the Act may not obviate this problem
because it applies only to patented devices. The Environmental
Protection Agency will closely monitor research and development
activities conducted by each member of the industry. In addition,
the Agency will urge the Department of Justice to continue to
approve limited arrangements between particular manufacturers
that may be needed to meet special problems.
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CHAPTER 6: Costs
A. Cost of Attaining the 1975 and 1976 Standards
Precise estimates of the cost of attaining the 90%
reductions in HC, CO, and NOX required by the Clean Air Act
amendments of 1970 cannot be made at this time. The total
cost to the public will, however, include the initial cost
of the control system, its maintenance after warranty,
and expected increases in fuel consumption and reductions in
vehicle performance.
Preliminary estimates of the cost of the 1975 HC and CO
control systems have been made by the manufacturers. However,
no final decision on the control system to be used has yet
been made. Since the technology for achieving the desired
levels of NOX control for 1976 is not now available,
estimates of the related costs are even more speculative.
However, it appears that costs associated with 1975 and 1976
standards will be considerably greater than those experienced
in achieving Federal emission standards through 1974.
A variety of control systems are under development for
meeting the 1975 HC and CO standards. Figure 1 indicates the
estimated cost per car of achieving control standards through
1975. Costs through 1974 are derived from estimates published
in EPA's Cost of Clean Air report of March 1971. Estimates
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of the cost of 1975 vehicles were provided informally by
manufacturers and range from 80 to 600 dollars per car.
Thus far, EPA has not been able to develop an independent
estimate for 1975 costs. As indicated above, precise cost
estimates cannot be made for 1976 standards.
Also included on Figure 1 is a table showing the
percent reductions in emissions for the various model years
compared to those emanating from uncontrolled vehicles.
As explained in Chapter 1, the legislation requires that
1975 vehicles include a 90% reduction in HC and CO emissions
compared to the levels permissible in 1970, and that 1976
vehicles include a 90% reduction of NOX from the levels
observed in 1971 uncontrolled autos. Since the 1970 base-
line vehicles included some emission controls of HC and CO,
the 1975 standards for these emissions require very high
levels of control when measured against uncontrolled
vehicles. It should also be noted that the cost per car
indicated in Figure 1 covers only the initial production
costs and does not reflect any costs for maintenance after
warranty or increases in fuel consumption or reductions or
vehicle performance.
Figure 2 was prepared by the Department of Commerce
on the basis of informal information obtained from automobile
industry sources. This graph depicts the estimated increases
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INITIAL COST PER CAR
OF EMISSION
CONTROL SYSTEMS
Does not include the cost of
maintenance after warranty and
_^ • • • I j, • • m •
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500
400
300
200
100
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ecomony and performance f
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69|70 71| 72 73|74 75 71
MODEL YEAR
% REDUCTIONS OF POLLUTANTS REQUIRED
BY FEDERAL STANDARDS COMPARED
TO UNCONTROLLED VEHICLES
62
0
69
25
FIGURE 1
97
25
97
90
-------
ESTIMATED COST PRICE PER CAR
TO CONTROL AUTO EMISSIONS
COST(price)PER CAR
S600
500 -
400 -
300 -
200
100
0 10 20 30 40 50 60 70 80 90
FIGURE 2 Percent AUTO EMISSION CONTROL June 1971
Source Generalized from manufacturers'private estimates prepared by the Department of Commerce
100
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in production costs per car in the 1976 model year of
controlling HC, CO, and NOX at various levels of emission
reduction—assuming that all three pollutants would be
controlled at the same level. Since all three pollutants
will not be reduced by the same amount from the baseline of
uncontrolled vehicles, this graph is merely illustrative
of the principle that costs of control are expected to rise
steeply as emission reductions move beyond some point. The
thrust of this illustration is that the last 5-10% is likely
to be much more costly to remove than the first 5-10%, but
these figures are not known with certainty.
B. Cost-Effectiveness of Motor Vehicle Emission Control
Under Section 312(a) of the Act, the Administrator of
EPA is required to report to Congress on January 10 of each
year concerning the economic impact of achieving air quality
standards. Among other things, that report is intended to
provide a basis for evaluating the program and costs for
achieving air quality standards. Accordingly, future reports
submitted under Section 312(a) will address some of the key
economic issues involved. In the public interest, ambient air
6-5
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quality standards should be achieved at the least cost
possible. Since knowledge of effects of air pollution and
of technology for controlling emissions is constantly
improving, it will be necessary to periodically review the
effectiveness and costs associated with alternative approaches
of meeting ambient air Quality standards and thus protecting
the Nation's health and welfare.
As indicated in Chapter 4, the control of auto emissions
is an important element in achieving the ambient air standards
for HC, CO, NOX, and photochemical oxidants. However, the
relationships between automobile emissions control and the
achievement of national ambient air quality standards is
extremely complex. For example:
a) Motor vehicles are not the only important sources
of HC, CO, and NOX. Other sources are identified
in the table on page 4-1.
b) The significance of auto emissions upon ambient air
quality varies from place to place, and therefore
so does the effectiveness of auto emission controls
compared to controls over other sources.
c) The cost of HC, CO, and NOX control for motor
vehicles are interrelated since some types of HC
and CO control make it more difficult to reduce
emissions of NOx-
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d) Meeting the 1975/76 standards will have a cumulative
impact over time on air quality as new controlled vehicles
replace older models in the automobile fleet. This can
be seen on Figures 3, 4, and 5, which depict EPA estimates of
future national levels of NOx, HC and CO emissions from gasoline-
fueled motor vehicles assuming all future Federal standards are
achieved. The graphs do not reflect the possible impact of
modifying used vehicles to attain emission reductions.
Considerations such as these are particularly important
in attempting to find the least cost means of achieving ambient
air quality standards, since the impact of achieving various
reductions in automobile emissions will influence the costs
of reducing pollutants from other sources. Other sources
of particular pollutants (e.g., NOX from power plants) may be
so important in some areas that the reduction of automobile
emissions will contribute relatively little to meeting ambient
standards in that area.
C. The Relationships between Costs and Effectivensss in
Reducing Air Pollution
As suggested earlier in this chapter, many of the
relationships between costs and effectiveness are not yet
well understood. All of these factors require further study
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<
Q
(/) Q.
UJ O
OXIDES OF NITROGEN EMISSIONS FROM
MOTOR VEHICLES IN THE UNITED STATES
1965-1990
10.0
8.0
6.0
P § 4.0
O =!
2.0
1965
FIGURE
3
1970
1990
1975 1980 1985
MODEL YEAR
PROJECTIONS BASED ON ACHIEVING
ALL FEDERAL EMISSION STANDARDS
-------
HYDROCARBON EMISSIONS FROM
MOTOR VEHICLES IN THE UNITED STATES
1965-1990
O d
1965
FIGURE
4
1970
1990
1975 1980 1985
MODEL YEAR
PROJECTIONS BASED ON ACHIEVING
ALL FEDERAL EMISSION STANDARDS
-------
er
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HI O
CARBON MONOXIDE EMISSIONS FROM
MOTOR VEHICLES IN THE UNITED STATES
1965-1990
100
80
60
40
20
1965
FIGURE
5
1970
1990
1975 1980 1985
MODEL YEAR
PROJECTIONS BASED ON ACHIEVING
ALL FEDERAL EMISSION STANDARDS
-------
to ensure that desirable levels of air quality are achieved
at the most reasonable level of costs to the American people.
Knowledge today is simply not adequate to identify specific
numerical values for costs and benefits.
However, even without the specific data, some conclusions
can be drawn. Beyond some point, costs will increase more
rapidly as successively greater reductions in emissions are
achieved. However, in some situations, the la.<*t increment
of impurity in the air will be less important to remove than
the earlier increments. Thus it will be important to consider
both the cost and value of incremental improvements in air
quality.
A great deal of the knowledge required to assess the
cost-effectiveness of various alternative pollution control
strategies is expected from the review of State implementation
plans which must be prepared during the coming months. These
implementation plans will provide considerable information on
the sources and amounts of emissions. This knowledge will
increase further as monitoring and surveillance programs are
improved and expanded. In addition, EPA's research programs
are designed to improve knowledge of the health and other
effects of various pollutants. This information, together
with economic analyses that will be carried out or supported
by EPA should provide an improved basis for future program
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decisions.
D. Industry Sponsored Research and Development
In response to the Administrator's letter of February 26,
1971, the industry supplied EPA with information concerning
their expenditures for developing and testing emission control
systems. These responses indicated industry-wide costs of
nearly $250 million in 1970 with a one-third increase
projected for 1971. This information also revealed that
about six thousand professional and technical personnel were
engaged in emission control research and development programs
for the manufacturers in 1970, with a similar one-third expan-
sion projected for 1971. Thus, there has been a significant
increase in industry resources devoted to emission control
programs since the passage of the 1970 amendments to the Act.
The information supplied by the industry appears to lack
total comparability due to the variations in definitions and
allocations of cost figures. In addition, much of this
information furnished was indicated as being confidential
by the manufacturers who alleged that it related to "trade
secrets." Section 208 of the Act allows the Administrator
to keep information confidential if he finds that it does in
fact relate to "trade secrets." EPA does not agree that all
of the information so indicated relates to "trade secrets."
V7ork is underway to develop appropriate protocols to permit
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the collection of data on the magnitude of the industry's
emission control efforts on a fairly consistent basis. This
information should be available for public distribution at
some time in the future.
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