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NATIONAL ACADEMY OF SCIENCES

OFFICE OF THE PRESIDENT 2101 CONSTITUTION AVENUE WASHINGTON, DC 20418

February 15, 1973

The President of the Senate
The Speaker of the House of Representatives
The Administrator of the Environmental Protection Agency

Sirs:

I have the honor to transmit a report summarizing the work and findings of our Committee on Motor Vehicle Emissions in accord with the provisions of Section 6 of Public Law 91-604, the Clean Air Amendments of 1970. We trust that this report will be of assistance to the Administrator of the Environmental Protection Agency in discharging his responsibilities under that Act and that it will inform the Congress of the progress which has been made, to date, toward achieving some of the goals of that Act.

The report constitutes a description, as of 1 February, of the "technological feasibility," on the part of the automobile and related industries, of achieving the automotive emissions control standards established by the Act. As the report reveals, that Act has stimulated an almost worldwide effort to develop effective emissions control systems. Of necessity, however, this report is presented at a time when the pace of developments can readily overtake categorical conclusions based on the information available today; it is, therefore, a review of the current "stateof-the-art," presented while that state is changing rapidly, and not a summary of a stabilized situation. It is for that reason, inter alia, that the report presents an analysis but offers no recommendations concerning enforcement, on schedule, of the relevant provisions of the Act.

The Committee defined "technological feasibility" to mean that an emissions control system capable of meeting the standards set for the three major pollutants can be developed, designed, produced in large numbers, and maintained in service, all at reasonable cost. By these criteria, the Committee's analysis indicates that achievement of the 1975 standards may be technologically feasible and that achievement of the 1976 standards is likely but may not be attainable on the established schedule.

However, these seemingly definitive conclusions are offered with several reservations which are held in varying degrees of

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gravity by individual members of the Committee. The nature of these reservations will be found in the report. They are concerned, variously, with the durability in customer use of catalystdependent control systems, the requirement for a network of inspection and maintenance stations, the actual likelihood of sufficiently early development of a dual-catalyst system capable of achieving the 1976 standards, and the likelihood of manufacture for Model Year 1976, on a scale commensurate with projected total national production, of a sufficient number of vehicles actually capable of meeting the 1976 standards in customer use.

The Committee is seriously concerned that the certification procedure may not prove to be an adequate indicator of the continuing reliability of catalyst-dependent, emissions control systems under the more stressful, varied conditions of consumer use. Data in this regard are not yet available, even for systems intended to meet the 1975 standards. To assure that vehicle classes certified for production actually do continue to meet the prescribed standards, the Committee considers it advisable to develop a network of inspection and maintenance stations and to train a corps of mechanics sufficient to that task. Some of the Committee, however, suggest that no more need be done than to enforce the recall provision of the Act, when so indicated by defective behavior of a reasonable sample of vehicles. It should be noted, however, that whereas that provision is binding upon the manufacturer, it is not mandatory for the vehicle owner to respond. In view of the low response to recalls for defects relating to passenger safety (30 to 50%), simple use of the recall provision under these circumstances would not suffice to meet the goals of the Act.

In this regard also, it should be noted that there is not available, for such national use, a relatively simple, foolproof, reliable, diagnostic instrument for assessment of the automotive enission of the three pollutants with which the Act is concerned. It may be necessary for the Environmental Protection Agency to stimulate the research and development required to make such instrumentation available on the schedule necessitated by the Act.

The Committee found it unnecessary and inadvisable to recommend a set of interim standards for 1975 or 1976 model year vehicles. But, while contemplating its responsibility for such a recommendation, under the terms of the contract, the Committee became aware of controversies surrounding many aspects of the problem of standard setting, e.g., the nature and magnitude of the hazards to health posed by the pollutants released in automotive emissions, the relationships among the various pollutants and their ambient concentrations with respect to their health effects, the relative contributions of mobile and stationary power sources, etc. Resolution of these controversies appears imperative to long-term policy with respect to the protection of air quality. Hence, on page 127, the Committee urges that Congress and the Environmental

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Protection Agency initiate a comprehensive study of these and related matters. This Academy would be pleased to be of assistance in such an effort. That recommendation should not be interpreted as taking exception to the standards established by the Clean Air Act of 1970. Most of the Committee believes that only if such an examination were to reveal compelling evidence and arguments to the contrary should the effort to achieve the emissions control standards established by the Act be relaxed; indeed, the Committee is particularly concerned that continued progress be made with respect to improvement of air quality in those urban centers where, patently, automotive emissions have contributed significantly to the deterioration of the local environment.

A major quandary which the Committee wishes to place before the Congress and the Environmental Protection Agency (page 5) arises from awareness of the relatively recent development, largely in the hands of a Japanese manufacturer, of a dual-carbureted, stratified charge engine. Although the general principle is not new, the particular design in question, incorporated into small size engines, has met the 1975 certification standards and bids fair to meet the 1976 standards. As compared with the catalyst-dependent systems now being emphasized by the major manufacturers this system offers the promise of lower initial purchase costs, greater durability in service and significantly greater fuel economy. The Committee is concerned that mass production of what are presently deemed to be relatively fragile, catalyst-dependent systems,

of unproved reliability in actual service, may engender an episode of considerable national turmoil. It is further concerned that, once committed to the manufacture of catalyst-dependent control systems, rather than switch to some more generally acceptable system such as a version of the stratified charge engine that now offers great promise, the relatively ponderous automobile industry will continue to manufacture catalyst-dependent systems for some years, albeit, presumably, while also seeking more durable catalysts and mechanisms to reduce the severe fuel penalty of current catalyst-dependent systems with their associated mechanical features. The dilemma, then, is to determine what course of action, by government, would assure the earliest possible optimal outcome while scrupulously avoiding dictation, by government, of the technology to be used. The Committee offers no recommendations in this regard.

Relevant to this situation are the costs, per vehicle, associated with the initial purchase, `maintenance and operation (including the effects on fuel consumption) of the various emissions control systems under consideration. The annualized incremental costs, viz., the cost per car/year for a standard engine, relative to a 1970 standard engine, due to the emission control system, for operation and maintenance of the vehicle with the purchase cost of the system amortized over the first five years of operation, were

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