Imágenes de página
PDF
ePub

about 8 percent above. Reports in 1970 show hydrocarbon emissions higher than the standard by 25 percent and carbon monoxide by about

10 percent.

TABLE 2.-Exhaust Emission Standards and Uncontrolled Vehicle Emission Levels Based on Current and Proposed 1972 Test Procedures

[merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][ocr errors][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small]

Remedies for the failure of production line cars to perform as well as their prototypes are both administrative and legislative. New tests to be applied for the first time to 1972 models include a revised durability test. It will more accurately reflect actual operating conditions. And the manufacturer will be required to make available to NAPCA test cars to be under the control of the Federal Government in accumulating durability mileage.

Proposed Presidential amendments to the Clean Air Act would authorize HEW to withdraw approval of a particular model of car if vehicles coming off the production lines do not meet the Federal standards. Moreover, the Secretary of HEW would be explicitly authorized to test, or require manufacturers to test, vehicles at the end of production lines. Even with these safeguards, many automobiles will not meet the standards. In addition to systems that break down or are not sufficiently durable, the car owner may not provide proper maintenance. The data on present levels of pollution in our urban environment,

the projected increase in urban traffic in the years ahead, and the performance of pollution control systems under actual driving conditions make it clear that even applying stricter standards in 1975 will only prolong the downward curve in vehicle emissions until the middle 1980's. After that, carbon monoxide levels will again rise because of the sheer number of automobiles on the roads and highways.

Motor vehicle pollution is the product of a complex combustion system of engines, fuels, and fuel additives. Effective control, then, means dealing not only with engines and control devices but with the fuel itself and with fuel additives. The President's proposed legislation includes authority to establish standards and regulations for both fuel and fuel additives.

The key additive from an air pollution control viewpoint is tetraethyl lead in gasoline. It accounts for a significant portion of the particulate pollution from automobiles. Most experts believe that control systems incorporating chemical catalysts will be required to meet 1975 standards. Experience to date indicates that lead in gasoline poses serious problems to the use of catalytic control devices. Although other control methods are likely to be available, the catalyst appears to be most economical and durable. A panel of the Commerce Technical Advisory Board concluded that lead-free gasoline should be ready within the next few years so that industry will have the chance to roadtest these catalytic devices. Automobile manufacturers say that they intend to market vehicles with low-octane requirements in their 1971 models, thus reducing or even eliminating the need for lead in gasoline.

The Secretary of HEW has asked the chief executives of the Nation's petroleum companies to work toward production of a lead-free gasoline. The Secretary suggested a plan to reduce lead levels in regular grades to 0.5 gram per gallon by July 1, 1971, and to zero lead content by July 1, 1974. However, since premium gasoline containing lead will still be needed for a number of years to meet the requirements of high compression engines in older cars, the Secretary's plan provides for leaded premium gasoline as long as it is needed. To make the new gasolines competitive, the administration has requested a $4.25 per pound tax on lead used in gasoline.

An alternative to the internal combustion engine may be necessary if it cannot meet the increasingly stiff standards. The President announced in his February 10, 1970, environmental message a program to develop one or more alternatives within 5 years. He called for:

Carbon Monoxide Emissions by Motor Vehicles

in the United States, 1960-90

[blocks in formation]

• An extensive research and development program to be conducted under the general direction of the Council on Environmental Quality;

• An incentive program to private developers, through Government purchase of privately produced unconventional vehicles for testing and evaluation.

Controlling Sulfur Oxides

Sulfur oxides are one of the most difficult classes of air pollutants to control. Because of their toxicity and pervasiveness, they are among the most dangerous air pollutants to human health and are clearly the most harmful to vegetation, buildings, and materials. Because their source is chiefly the electric power industry, their potential increase is tied to that burgeoning industry, which almost doubles its output every 10 years.

At present about 65 percent of the energy for generating electricity stems from coal; gas, oil, and hydroelectric sources account for about 34 percent; and nuclear energy the remaining 1 percent. By 1980, 22 percent of the total installed electric power capacity is expected to be nuclear. By 1990, it will be 40 percent. However, by far the greatest source of energy is now, and will continue to be for the rest of this century, the burning of coal and oil. The amount of coal used for power by the year 2000 will be four times greater than it is today.

A number of alternatives are available to control sulfur oxide pollution over the next decade. Switching fuels is possible, but only when an alternative, low-sulfur fuel is available. Most coal near the Nation's centers of population and power demand is high in sulfur. Lowsulfur coal not only is far away but also commands a higher price for use as coke by domestic and foreign steelmakers. North Africa and other areas are rich in low sulfur oil but are limited by low production and refinery capabilities. Oil import quotas bar it from certain areas of the Midwest and the West Coast, although the oil may be imported to other areas of the United States. The United States will probably continue to rely primarily on residual oil from the Western Hemisphere. And that oil will have to be desulfurized before it is used. Natural gas carries an insignificant sulfur content, but it is the scarcest of fossil fuels, and most of it is being conserved for nonpower purposes. Sulfur can be separated from coal and oil, but the processes are costly, and some are not fully developed technically. Methods to remove sulfur from the stack gases after the fuel is burned are under

[merged small][merged small][subsumed][subsumed][merged small][subsumed][merged small][merged small][merged small][graphic][subsumed][subsumed][subsumed][subsumed][subsumed][subsumed][subsumed][subsumed][merged small][merged small][merged small]

Sources: Water Resources Council; Bureau of Mines, Department of the Interior.

« AnteriorContinuar »