Clean Air Act Timeline

A short history of key moments in one of the most effective public health campaigns in U.S. history


1923: Putting the Lead In

Leaded gas — gasoline spiked with lead to enhance engine performance — is introduced to the market.  Although the harmful effects of lead to health are increasingly recognized, auto makers fight mandatory emissions control for their cars.

1967: Air Quality Act of 1967

Congress passes the first federal legislation aimed at reducing pollution. Without setting standards, imposing hard deadlines, and providing enforcement, though, it fails to accomplish its goals; however, it is a good first step that will provide a framework for more effective legislation down the pipeline.


1970: Earth Day

After seven years of trying to put the environment on the political map, Earth Day founder Senator Gaylord Nelson (D-WI, 1963-1981) finds inspiration in the 1969 anti-war movement and proposes a large-scale demonstration on behalf of the environment. The idea is big enough to make headlines across the country in major news outlets, which report on the planned event in the preceding months. On April 22, 1970 millions of participants across the country organize to voice environmental concerns, a grassroots effort that finally helps put the environment on the political agenda. Sen. Nelson said years later, "We had neither the time nor resources to organize 20 million demonstrators and the thousands of schools and local communities that participated. That was the remarkable thing about Earth Day. It organized itself."

1970: Clean Air Act

Congress passes ground-breaking rules to curb pollution, its principal provisions are:

1. Establishing National Ambient Air Quality Standards (NAAQS). The law requires that EPA identify and set standards for pollutants identified as harmful to human health and the environment. The six "criteria" pollutants are:

·         Carbon monoxide

·         Nitrogen dioxide

·         Ozone

·         Sulfur dioxide

·         Particulate matter with aerodynamic size less than or equal to 10 micrometers (PM-10)

·         Lead.

2. Primary and Secondary Standards. The Clean Air Act establilshes two categories of air quality standards: Primary standards set limits to protect public health. Secondary standards set limits to protect against public welfare effects, such as damage to farm crops and vegetation.

3. Leaded gasoline phasedown. The law requires leaded gas to be phased out by the mid-1980s — one of the single most important and successful environmental health initiatives of the last century.


1976-1980: Getting the Lead Out

With the phase-out of lead underway, blood-lead levels in human beings drop 50 percent by 1980.

1977: Clean Air Act Amendments

Because many states fail to meet mandated targets, the first set of Clean Air Act amendments is adopted. One of the most effective of these is the New Source Review (NSR), which addresses older facilities that had been "grandfathered" by the original law.

New Source Review. In 1970 Congress had assumed that older industrial facilities, such as power plants and refineries, would be phased out of production, so they were exempted from the legislation. But when these big polluters continued to operate and emit pollution at much higher levels than new facilities that were built with modern pollution-control equipment, lawmakers knew they had to act. The resulting New Source Review requires older industrial facilities that want to expand to undergo an EPA assessment and install pollution control technologies if their planned expansion will produce significantly more emissionsg. Alternately, these facilities can opt to offset the increased emissions by lowering them in other units they own. This way, older plants will not impinge on the cleaner air more modern plants are responsible for.

1980: Lead Phase-out Gets an Unlikely Boost

A year after the National Academy of Sciences reports that leaded gasoline is the largest single source of atmosphere lead, the Reagan administration’s Task Force on Regulatory Relief (chaired by Vice President George H. W. Bush) proposes abandoning the phase-out of leaded gas. When EPA Administrator Ann Gorsuch admits to a gas refiner that the agency would not enforce lead limits, the resulting bad publicity prompts a reversal ... and an unplanned speedup of the leaded gasoline phase-out.

1983: Blood-Lead Levels Continue to Drop

EPA reports that between 1976 and 1980, as the amount of lead in gasoline dropped 50 percent, blood-lead levels in children dropped 37 percent.

1988: New Source Review Challenged in Court

Wisconsin Electric Power Company sues EPA, challenging its application of NSR enforcement. In 1990 the Seventh Circuit Court rules that the company should not be subject to NSR because the new method EPA used to estimate emissions ("actual-to-future-actual") was not as appropriate a test as the one they had been using ("actual-to-future-potential"). Nevertheless, the ruling also qualified WEPCO's expansions as “non-routine.”

1990: Clean Air Act Amendments

Additional amendments to the Clean Air Act include acid rain control and the prohibition of leaded gasoline in motor vehicles by the end of 1995. Regarded as an innovative approach toward curbing sulfur dioxides (SO2) and nitrogen oxides (NOx), the two main sources of acid rain, the new provisions offered companies an array of choices to meet emissions standards.

1. Phase I and Phase II. The acid rain control provision targets SO2 and NOx producers in two phases. The first phase, from 1991 - 1995, affects the largest sources of SO2 and NOx. Phase II applies to virtually all fossil-fuel electric power producers.

Compliance Methods. Utilities have the choice of using any of the following ways to meet the standard annual emissions allowance limit:

·         Fuel switching or blending — using a cleaner fuel or choosing lower sulfur coal

·         Obtaining additional allowances

·         Installing glue gas desulfurization equipment, commonly referred to as scrubbers

·         Using previously implemented controls

·         Retiring units

·         Boiler repowering

·         Substituting Phase II units

·         Compensating with Phase II units

1995: Blood-Lead Levels Reach Single Digits

By 1995, the percentage of U.S. children with elevated blood-lead levels has dropped from 88.2% in the 1970s to 4.4%, according to data compiled by the Centers for Disease Control and Prevention.

1995: Cheap Victory

Despite protestations by some industry interests to the Clean Air Act regulations are prohibitively costly, the Department of Energy estimates that costs to power plants to reduce their pollution levels under the 1990 Clean Air Act Amendments accounted for merely 0.6 percent of the utilities’ overall $151 billion operating expenses.

1995: Acid Rain Reductions

Phase I units reduce their SO2 emissions by 45% from 1990 levels, while non-Phase I units emissions emit 12% more than in 1990.

2000: Cleaner Air Milestones

Almost all the pollutants that contribute to the National Ambient Air Quality Standards have significantly decreased since 1970:

Carbon Monoxide: 31% decrease
Sulfur Dioxide: 27% decrease
Particulate Matter* (PM-10): 71% decrease
Lead: 98% decrease

*Particulate matter — particles in the air — include soot, smoke, dirt, and liquid droplets.
Though not one of the six critieria pollutants,
volatile organic compounds, such as dry cleaning fluids and paint thinners, which contribute significantly to photochemical smog production and certain health problems, have also declined some 42% from their 1970 levels.

1999-2000: DOJ Sues

The U.S. Department of Justice files suit against seven utilities claiming that “repairs” undertaken over the past two decades without corresponding pollution control upgrades violate New Source Review. In 2001, however, incoming EPA administrator Christie Whitman publicly indicates to the defendants that they should refrain from settlement in the case — a move that suggests that the new administration would not pursue enforcement.

1999: TVA Lawsuit

In response to the compliance order that the Department of Justice issued against the Tennessee Valley Authority sues the EPA, challenging its interpretation of NSR. TVA charges that EPA is applying NSR to routine maintenance and repair.

2002: AMA Report

A report by the Journal of the American Medical Association credits Clean Air Act regulations pertaining to automobile emissions with a reduction in carbon monoxide-related deaths, saving 11,700 lives between 1968-1998.

2002: Walkout at the EPA

After ten years on the job, the head of EPA's Office of Regulatory Enforcement, Eric Schaeffer, resigns, claiming that the Bush administration is on a course to change environmental policies that have been touted for having eliminated millions of tons of air pollution. Schaeffer also claimed the Bush adminstration's changes would benefit power companies, charging that Energy Department officials treat the energy industry as their “client.”

2002: NSR Rollback Initiative

On Dec. 31, exactly 32 years after President Richard Nixon signed the Clean Air Act into law, the Bush administration announces significant rollbacks to New Source Review pollution control provisions. Highlights:

1. New rules will allow virtually all pollution increases from old, high-polluting sources to go unregulated. EPA will allow companies to avoid updating emission controls if their plant’s equipment has been reviewed at any time within the past decade, and the measures used to calculate emissions levels will be reconfigured.
2. The review process built into NSR will be drastically scaled back. Until now, when facilities wanted to expand their production, thereby increasing their emissions, they would have to apply for permission and undergo EPA scrutiny and public comment. The rollback will do away with this requirement. Communities will now not know when a nearby power plant is increasing the amount of pollutants pumped into their backyards. The new regulations are slated to go into effect in March 2003.

2003: Senate Rolls Back NSR

An attempt by Sen. John Edwards (D-NC) to postpone a rollback of the New Source Review rules is defeated in the Senate (46-50) during amendment votes on the 2003 budget bill; a competing amendment by Sen. James Inhofe (R-OK) wins (51-46), clearing the way for the Clean Air Act rollback.

by Erica Rowell  

Additional Information

Lead Phase-out
Starting in the 1920s, oil companies began adding tetraethyl lead to (TEL) gasoline to deliver greater power to internal-combustion engines. Although this added a lethal element to the air, auto manufacturers resisted efforts to install more effective emission controls in their cars. By the 1960s, though, the tide began to turn. Scientific studies showed that the high incidence of lead in industrial communities (compared to non-industrial ones) proved that man-made lead sources had an impact on clean air (while deadly effects of lead on human beings had been known for years.) Though these findings did not push gas manufacturers to stop producing leaded gasoline — Standard Oil's Frank Howard called TEL "a gift of God" — car companies initiated a change. Catalytic converters were the answer to improved engine efficiency, and leaded gasoline would not work with them. In 1970, General Motors announced it would make the switch to cleaner gas by 1974 to meet the requirements of the Clean Air Act. The other major auto companies followed suit.

a) 1975 – 1979: Permissible lead levels in unleaded and leaded gasoline reduced from 1.7 grams/gallon to 0.5 grams/gallon

b) 1984: Permissible lead levels in “leaded” gasoline reduced first to 0.5 grams/gallon, then to 0.1 grams/gallon

The New York Times coverage of the first Earth Day:
"Rising concern about the environmental crisis is sweeping the nation's campuses with an intensity that may be on its way to eclipsing student discontent over the war in Vietnam ... a national day of observance of environmental problems ... is being planned for next spring ... when a nationwide environmental 'teach-in' ... coordinated from the office of Senator Gaylord Nelson is planned."
                         Gladwin Hill,
The New York Times, Nov. 30, 1969