CHAPTER 11 CONTROL OF AIR POLLUTION FROM MOTOR VEHICLE TRANSPORTATION BY THE FEDERAL AND STATE GOVERNMENTS
| Jurisdiction | United States |
(2000)
CONTROL OF AIR POLLUTION FROM MOTOR VEHICLE TRANSPORTATION BY THE FEDERAL AND STATE GOVERNMENTS
George Washington University Law School
Washington, D.C.
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§ 11-1. Introduction
Since 1967 the Clean Air Act (CAA) has had a program to control the common air pollutants that are emitted in large quantities in order to achieve the prescribed ambient air quality standards.1 Since 1970 this CAA program has been based on uniform national ambient air quality standards (NAAQS)2 first promulgated by the Administrator of the newly created Environment Protection Agency (EPA)3 on April 30, 1971.4 The NAAQS are numerical values for the concentration of criteria pollutants in the ambient air. These "criteria" pollutants have not changed much in thirty years. There were six original criteria pollutants: particulates, sulfur dioxide (SO2), carbon monoxide (CO), ozone, nitrogen dioxide (NO2), and hydrocarbons (HC).5 In 1978 the EPA added lead as a criteria pollutant,6 and in 1983 the Agency delisted hydrocarbons.7 In 1987, the EPA changed the particulate standard to only control particles less than or equal to ten micrometers in diameter (PM10).8 While hydrocarbons were removed as criteria pollutants, chemically reactive hydrocarbons known as non-methane hydrocarbons (NMHCs) and volatile organic compounds (VOCs) continued to be regulated by the CAA because they are chemical precursors to the formation of tropospheric ozone, which is a criteria pollutant; nitrogen oxides also are regulated because they are precursors to ozone formation.9
The significance of an air pollution control program based on NAAQS is that the various sources of air pollutants compete to use the atmosphere's capacity to assimilate pollutants because the government's air pollution control officials allocate emissions reduction requirements among the various sources of air pollution. The United States, pursuant to CAA section 107,10 has been divided into 264 air quality control regions (AQCRs) for air pollution control planning.11 The plans for each AQCR in a state are aggregated to become the state implementation plan (SIP) that is the
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basic template for air pollution control efforts by the state.12 Most of the effort to control air pollution focuses on the 130 nonattainment areas on the EPA's nonattainment list.13 There are seventy particulate matter (PM10) areas, thirty-eight ozone areas, and twenty CO areas on the nonattainment list. There are no nonattainment areas for NO2.14
The EPA uses the threat of sanctions15 to force the states to develop a SIP detailing the process by which the state intends to control emissions in order to meet the NAAQS.16 The SIPs must include plans to control stationary sources, transportation sources, and other sources necessary to meet the NAAQS.17 The EPA must approve each SIP,18 and it retains jurisdiction to impose requirements or penalties if a state fails to perform its duties under the Clean Air Act.19 But it is the states, with one significant exception, that usually implement the CAA. The exception is the program to control emissions from new motor vehicles based on the provisions of subchapter II of the CAA.20 Since 1967 the federal government has preempted, with some exceptions,21 the control of emissions from new motor vehicles.22 To control air pollution from motor vehicles Congress enacted a four pronged approach in the CAA Amendments of 1970,23 which, with numerous modifications,24 continues after several major amendments to the Act. The major mobile source program is found in CAA subchapter II, and aims to control emissions from new engines and vehicles.25 Other CAA programs control fuels and fuel additives,26 emissions from in-use vehicles,27 and transportation planning.28 These programs are addressed below.29
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The major regulated pollutants from motor vehicles are carbon monoxide (CO), nitrogen oxides (NOx), VOCs or NMHCs,30 and particulate matter (PM10) from diesel engines.31 VOCs and NOx react in the presence of sunlight to produce photochemical oxidants.32 Photochemical oxidants, regulated as ozone, and a myriad of less easily identifiable air pollutants are commonly known as smog.33 Transportation sources in the United States in 1997 were responsible for a large percentage of the nation's total emissions. These included 76.6% of the CO emissions, 49.2% of the NOx, and 39.9% of the VOCs, as well as 23.0% of the PM10, 13.3% of the lead, and 6.8% of the SO2 emissions.34 From 1988 to 1997, CO emissions in the United States from transportation sources decreased twenty-two percent,35 and VOCs decreased twenty-eight percent.36 Nitrogen oxide emissions from highway vehicles decreased eight percent from 1988 to 1997.37 Based on 1997 data, about 52.6 million people in the United States reside where an air quality standard is violated. Over forty-seven million people live where the ozone standard is exceeded, and 9.1 million live where the CO standard is violated.38
Other substances emitted from motor vehicles may be regulated as hazardous air pollutants (HAPs).39 Motor vehicles are responsible for the release of approximately twenty-one percent of the nation's HAPS, although the contribution ranges from as much as fifty-five percent in Hawaii to as low as ten percent in Alabama.40 The EPA estimates that HAP emissions from mobile sources decreased about sixteen percent from 1993 to 1996, primarily because of the shift to the use of reformulated gasoline.41 For the thirty HAPs that pose the most significant health risk, EPA estimates that mobile sources contribute thirty-one percent in rural areas and forty-five percent in urban areas.42 In addition, motor vehicles are significant sources of stratospheric ozone depleting
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substances because of the chemicals used in motor vehicle air conditioners.43
Transportation sources also account for thirty-two percent of the U.S. carbon dioxide emissions from fossil fuel consumption in 1997,44 which are the leading cause of global warming.45 Each gallon of gasoline used by a motor vehicle results in about twenty pounds of CO2 (containing 5.47 pounds of carbon) being released into the atmosphere.46 Since 1984, CO2 emissions from United States transportation sources have increased from 379.0 million metric tons (mmt) of carbon to 473.1 mmt in 1997.47 However, this tonnage increase represents just a 1.7% increase in the transportation share of the overall CO2 emissions from total fossil fuel use over the same period of time.48 The worldwide contribution of motor vehicles to the emissions of global warming gases is far more dramatic. Since 1950 there has been an increase in automobiles in the world from about fifty-three million to about 486 million in 1996, which has resulted in the U.S. percentage of the world's registered automobiles decreasing from 76.0% to 26.7% in forty-six years.49
Today motor vehicles used in the United States emit significantly less pollution per mile traveled than the vehicles of the 1960s.50 As previously discussed, however, in 1997 transportation sources still accounted for over three-quarters of the CO, about two-fifths of the VOC, and about half of the NOx emissions in the U.S.51 The improvements in emissions from mobile sources were made while annual vehicle miles traveled (VMT) were increasing. Since the 1970 CAA was enacted, annual VMT has increased from slightly over 1.100 trillion miles to 2.560 trillion miles in 1997.52 This increase in the use of motor vehicles helped nullify the reductions in exhaust emissions per VMT achieved through the use of air pollution controls. In addition, the increased size of the vehicle fleet reduced the overall effectiveness of evaporative controls. In 1970 there were 89.244 million automobiles and 14.211 million light trucks registered in the United States; in 1997 the number had increased to 129.749 million automobiles and 70.224 million light trucks.53
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These figures show the mix of vehicles changed dramatically as sport utility vehicles (SUVs) and light-duty trucks were used as substitutes for automobiles. In 1976, pickup trucks, vans, and utility vehicles made up 19.8% of vehicle sales; in 1998 it was 30.69%.54 The expanded use of trucks and SUVs results in higher emissions55 and significantly lower fuel efficiency than if the vehicle fleet was primarily automobiles.56 The fuel economy of automobiles for the model year (MY) 1999 averages 28.3 miles per gallon (mpg), while MY 1999 light-duty trucks average 20.8 mpg.57 Fossil fuels used for transportation went from 8.38 quadrillion BTU (quads) in 195058 to 16.04 quads in 1970 and then increased to 19.24 quads in 1977 and 21.80 quads in 1990.59 In 1998 it had climbed to 24.25 quads.60 This is an increase, for the 1988 to 1998 period of 1.1% per year. The reason that air quality in the United States has modestly improved despite substantial increases in vehicle miles traveled and in the size of the vehicle fleet is due to the development of technologies that have produced significant reduction in emissions per vehicle mile traveled. The continuing increase in the consumption of transportation, however, requires continuing efforts to develop technology that will control emissions. But with transportation using two-thirds of the petroleum consumed in the U.S. in 1998,61 the air quality impacts of transportation makes this sector of the economy a major competitor with the other sectors of the economy for the right to use the atmosphere for pollution discharges.
§ 11-1(a). The Failure to Attain The NAAQS
The NAAQS define air quality goals and have the effect of limiting total emissions. Thus, emissions from motor vehicles are in competition with stationary sources to use the finite carrying capacity of the atmosphere to transport and disperse pollution emissions. The failure to...
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