Module 46 Major Air Pollutants and Their Sources

Module 47 Photochemical Smog and Acid Rain

Module 48 Pollution Control Measures

Module 49 Stratospheric Ozone Depletion

Module 50 Indoor Air Pollution

The summer of 2012 was not kind to Chattanooga, Tennessee. Dust storms in the West led to a number of poor air quality days in a city that is generally known for very good air quality. Chattanooga sits along the Tennessee River in a natural basin formed by the Appalachian Mountains, one of which—Lookout Mountain—rises 600 m (1,970 feet) over the city. After the Civil War, foundries, textile mills, and other industrial plants were quickly built and Chattanooga soon became one of the leading manufacturing centers in the nation.

The economic boom in Chattanooga had an environmental cost. Like Los Angeles and many other highly polluted cities, Chattanooga is located in a bowl formed by surrounding mountains. This geography traps pollutants that hover above the city. By 1957, Chattanooga had the third-worst particulate pollution in the country and rates of respiratory diseases were well above the national average. Over the next decade conditions worsened and by the 1960s, people were often unable to see Lookout Mountain even from a distance of a quarter mile. In 1969, a U.S. survey of the nation’s air quality confirmed what many Chattanooga residents suspected: Their city topped the list of the worst cities in the United States for particulate air pollution.

Obviously the poor quality of the air needed to be addressed. In 1969, Chattanooga, in conjunction with Hamilton County, created its own air pollution legislation by enacting the Air Pollution Control Ordinance. It controlled the emissions of sulfur oxides, allowed open burning by permit only, placed regulations on odors and dust, outlawed visible automobile emissions, capped the sulfur content of fuel at 4 percent, and limited visible emissions from industry. At the same time, the city and county governments put in place new pollution monitoring techniques to make sure the ordinance was being followed.

518

The city and county governments, along with private industry, poured approximately $40 million into the cleanup effort. Actions to improve air quality did not hinder business, as some people feared, but rather created new industrial opportunities related to the cleanup effort, such as the establishment of a local manufacturer of smokestack scrubbers. As a result of all these measures, in 1972—just 3 years after passage of the city ordinance and 2 years after the passage of the Federal Clean Air Act—Chattanooga achieved compliance with Clean Air Act air-quality standards.

The people of Chattanooga and the local governments recognized that keeping their air clean and maintaining economic sustainability would be an ongoing effort. To maintain their newly improved air quality, the city government and local businesses began several programs. One such program was a comprehensive recycling program, chosen as an alternative to a waste incinerator that would have added particles to the air. Public and private sectors successfully partnered to achieve both environmental and economic sustainability in creating the largest municipal fleet of electric buses in the United States, manufactured by another local business.

Unfortunately, while Chattanooga’s efforts dramatically reduced the levels of particulate pollutants, the concentration of ozone, mostly from automotive pollutant precursors within and beyond the city limits, continued to climb. Ozone concentrations exceeded the 1997 standard of 0.08 parts per million by volume set by the Environmental Protection Agency. Chattanooga has responded to the new air pollution problem in the same way it faced the particulate pollutant problem of the 1960s—through a combined effort of government, the public, and local industries. The city and county governments formed an Early Action Compact with the EPA, agreeing to improve ozone concentrations ahead of EPA requirements in return for not being labeled a “nonattainment area,” a designation that can result in the loss of federal highway funds and create a negative image that makes industrial recruitment and economic development more difficult. Like the 1969 Air Pollution Control Ordinance, the new Early Action Compact calls for a concerted effort by private and public sectors, and includes educating people on how they can limit ozone production on high-ozone days.

Chattanooga attained the 0.08 parts per million standard in 2007, two years ahead of schedule. However, national legislation has since lowered the ozone standard to 0.075 parts per million. In 2011, before the dust storms from the West, Chattanooga met the new, lower ozone standard. However, residents know that to achieve their goals of an economically vibrant city with clean air, they must continue to encourage cooperation among government, people, and business. They also need fewer dust storms from the West.

Sources: Chattanooga Area Chamber of Commerce, Summary of the Chattanooga Area Chamber of Commerce’s Position on Strengthening the National Ambient Air Quality Standard for Ozone, 2010, www.chattanoogachamber.com; National Ambient Air Quality Standards: www.epa.gov/ttn/naaqs.