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Clean Air Facts

The Clean Air Act Cleans Up Old Power Plants

Each year coal-fired power plants pump tens of millions of tons of toxic pollutants into the air, endangering our health and the health of our environment. Today, there are more than 500 such facilities in the U.S., and the majority of them were built decades ago. These older plants are significantly dirtier than their modern counterparts, emitting up to ten times more pollution than facilities built today.

Why do Older Plants Pollute More?

In passing the Clean Air Act in the late 1970s, Congress included a "grandfathering" loophole that allowed older power plants to avoid meeting the modern pollution control standards that new facilities had to adopt. Congress permitted such a loophole with the expectation that these "grandfathered" facilities would soon retire and be replaced by cleaner, newer plants. However, the majority of these older plants are still in operation today.

Closing the Loophole: New Source Review

In an effort to limit the abuse of the "grandfathering" loophole and protect Americans from vast increases in pollution, Congress created a key provision in the Clean Air Act known as "New Source Review" (NSR). This provision treats "grandfathered" power plants as "new sources" when they expand or significantly modify their facilities. It requires them to either (1) prevent additional pollution by offsetting any increases with reductions in other sources at the same plant site, or (2) obtain a clean air permit demonstrating that the best available pollution control technology has been installed.

New Source Review: Avoidance and Enforcement

NSR is triggered only when plants expand capacity or significantly modify their facilities. The EPA maintains that engaging in routine maintenance does not trigger this provision. In an attempt to bypass illegally NSR's requirements, many plants have claimed that they are engaging in routine maintenance when in fact they are making significant modifications or expanding capacity. These changes result in pollution that would have otherwise been avoided.

Over the past ten years, the EPA and Department of Justice have begun investigating this trend, finding many potential violators of NSR. To date, the EPA has brought enforcement actions against thirteen power companies at 51 power plants in twelve Midwestern and Southeastern states.

These facilities have, without exception, made modifications that were anything but "routine." The modifications were often the largest capital projects ever undertaken at the plants. These projects often involved years of planning and usually enabled the plants to operate more hours and produce more electricity. Without this so-called "routine maintenance" many of the power plants would have been retired.

Health Effects from Plants Charged with NSR Violations

According to the Justice Department and EPA, the failure of owners to install new emissions controls when they upgrade their facilities has resulted in tens of millions of tons of sulfur dioxide, nitrogen oxides and particulate matter. These pollutants increase airborne concentrations of fine particles, which are associated with a variety of serious health effects, including increased heart attacks and adverse birth impacts.

According to Power to Kill, Death and Disease from Power Plants Charged with Violating the Clean Air Act, a report released this month by the Clean Air Task Force, the 51 targeted plants shorten the lives of as many as 9,000 people and cause as many as 170,000 asthma attacks each year. Installing the modern pollution control technology required by NSR would avoid between 4,300 and 7,000 of these deaths and up to 120,000 asthma attacks. In Ohio, which has seven power plants under investigation, as many as 638 premature deaths occur each year as a result of pollution from power plants. Between 306 and 459 of these deaths could be avoided with modern emissions controls.

Although the current NSR cases involve plants located in the Midwest and Southeast, areas outside that targeted region have had to deal with the effects of this pollution. The Clean Air Task Force reports that emissions from these plants harm downwind states resulting in up to 2,100 premature deaths and 39,000 asthma attacks each year in the Northeast. If the targeted plants met modern pollution standards, as many as 1,700 deaths and 31,000 asthma attacks in Northeastern states would be avoided each year. In fact, Pennsylvania, which does not have any power plants under investigation, is among the top three states for deaths attributable to pollution from power plants. Between 546 and 705 premature deaths occur each year in Pennsylvania, up to 515 of which could be avoided annually if these power plants installed modern emissions controls.

Environmental Effects from Plants Charged with NSR Violations

NSR violators also harm our environment. As a group, the NSR violators currently under investigation make up a little more than 11 percent of the nation's electric capacity from fossil-fueled plants. However, these plants are responsible for more than 24 percent of the nitrogen oxides emissions and more than 27 percent of the sulfur dioxide emissions from all fossil-fueled plants nationally. These emissions contribute heavily to smog, acid rain, global warming and mercury contamination.

Great Smoky Mountains National Park experiences the environmental problems caused by NSR violators. Located in Tennessee and North Carolina where eleven power plants are under investigation for alleged NSR violations, this park recorded 52 days in 1999 where air pollution levels violated the federal health standard, according to the National Park Service. As a result, the air in the park was unhealthy to breathe one out of every three summer days.

The Future of Clean Air

Despite the high stakes for public and environmental health, the Bush Administration froze its investigation and enforcement actions against electric power generators on June 28, 2001 pending a review of the NSR cases by the Justice Department and a review of the NSR policy by the EPA. The key issue in these reviews is whether the law should be applied more leniently or even suspended in order to increase energy supply.

These reviews have hindered the start of new investigations and have also thrown into limbo settlements already agreed upon by power companies. Before the mandated reviews, EPA had reached a final settlement with Tampa Electric, and had reached agreements-in-principle with Cinergy, Inc. and Dominion Power. These settlements provide for a total emissions reduction of nearly 650,000 tons of sulfur dioxide and 300,000 tons of nitrogen oxides per year. Between 780 and 1,150 premature deaths would be avoided if such reductions occurred.

Now that these reviews are underway, however, the Cinergy, Inc. and Dominion Power settlements have been called into question. The Justice Department negotiators have informed Dominion Power that it should wait until August 17 before continuing with negotiations. In addition, Cinergy has indicated that it wants to reexamine its position and has joined other power companies in an alliance to fight the NSR enforcement effort.

Despite claims to the contrary, the EPA has found no evidence that companies obeying the rules established by the Clean Air Act and New Source Review have been prevented from expanding to meet the country's energy demands. There is evidence, however, that without such rules in place, future damage will be done to our health and our environment.

Power Plant Facts

Dirty Coal Power

We all use electricity in our daily lives, almost without thinking about it -- turning on the lights, listening to the radio, and using computers. If we stopped and learned about the energy we use, we would encounter some shocking realities about the impacts of the energy production process on the environment and our health.

Where Our Power Comes From

With all the amazing technological advancements over the last century, one thing that has not changed very much is our reliance on fossil fuels, in particular, dirty coal to generate electricity. In the US today, coal is the number one source of electricity produced (54%), followed by nuclear sources (21%), hydropower (16%), natural gas (9%), oil (2%), and other non-renewables (3%). As the producer of the largest share of our nation's energy, coal-fired plants are also some of the dirtiest.

Coal-Fired Power Plants Creating Pollution

Many older coal-fired power plants have enjoyed a loophole in the Clean Air Act, allowing them to avoid modernizing with pollution controls. As a result, as many as 600 existing power plants are between 30-50 years old and are up to 10 times dirtier than new power plants built today. When the Clean Air Act was proposed, this loophole was included to get it passed because Congress assumed that newer plants would come into compliance with the Clean Air Act standards and soon replace the older more polluting plants. For a variety of reasons, including efforts to heavily subsidize coal, this has not happened. Therefore, we are now faced with a disproportionate amount of pollution coming from these old, dirty, under-controlled plants.

Air Pollution from Coal-Fired Power Plants

Out of the entire electric industry, coal-fired power plants contribute 96% of sulfur dioxide emissions, 93% of nitrogen oxide emissions, 88% of carbon dioxide emissions, and 99% of mercury emissions.


When nitrogen oxide (NOx) reacts with volatile organic compounds (VOCs) and sunlight ground level ozone, or smog forms. Power plants are second only to automobiles as the greatest source of NOx emissions. NOx emissions from huge dirty coal plants with tall smokestacks in the midwest are often blamed for increased smog levels in many eastern regions because smog and its precursor pollutants are easily transported hundreds of miles downwind from pollution sources. More than 100 million Americans live in regions that fail to meet health-based smog standards.

Even our national parks have not escaped the smog caused by coal-fired power plants. Regional haze from airborne pollutants has reduced annual average visibility in the U.S., to about one-third in the west and to one-quarter in the east, of natural conditions. Smog concentrations increased at 17 of 24 National Park Service monitoring sites from 1992-1998. In fact, recently Cape Cod National Sea Shore has had higher pollution levels and more bad air days than Boston, and Shenandoah National Park in Virginia recorded higher levels of smog than any city in the Southeast except Atlanta, GA and Charlotte, NC in 1998.

When inhaled, smog causes a burning of the cell wall of the lungs and air passages. This eventually weakens the elasticity of the lungs, making them more susceptible to infections and injury and causing asthma attacks and other respiratory illnesses. This danger is present for anyone who inhales smog, although children, elderly, and those with respiratory problems are at a higher risk of developing health problems associated with smog pollution. A UCLA School of Medicine study found that over time, repeated exposure to smog and other air pollutants can cause as much damage to the lungs as smoking a pack of cigarettes a day. In addition, a recent Abt Associates study found that high smog levels in the eastern US cause 159,000 trips to the emergency room, 53,000 hospital admissions, and 6 million asthma attacks each summer.


The burning of coal emits sulfur dioxide (SO2) and nitrogen oxide (NOx) gases, which can form fine particles, or soot, when they react with the atmosphere. In addition, coal-fired power plants also emit soot directly from their smokestacks. Scientists increasingly believe soot to be the most dangerous air pollutant, blaming it for 64,000 deaths per year in the US, which is almost twice the number of deaths due to auto crashes. Cutting power plant pollutants by 75% would avoid more than 18,000 of those deaths.

Soot causes bacterial and viral respiratory infections like pneumonia, as well as chronic lung diseases, like asthma, that destroy lives over the course of years. Soot from power plants triggers an estimated 603,000 asthma attacks nationwide every year. Bringing old plants up to modern standards would be avoid 366,000 of these attacks. In addition, studies have found that soot may cause heart attacks and arrhythmia (irregular heartbeat) and that the incidence of strokes and heart failure is greater in areas with high levels of soot.

Acid Rain

Acid rain is formed when sulfur dioxide (SO2) and nitrogen oxide (NOx) react with water and oxygen in the atmosphere to form acidic compounds, most commonly sulfuric and nitric acid. These compounds can become incorporated into natural precipitation and fall to the earth as rain or snow. Coal-fired power plants are the largest source of SO2, 66%, and second to automobiles in NOx emissions. The Northeast and eastern Canada are home to some of the worst acid rain pollution, because emissions produced from large dirty midwestern coal power plants waft in the wind toward the northeast. For instance, numerous lakes and streams in the Adirondack mountains of upstate New York are too acidic to support fish life, and half of Virginia's native trout streams have reduced capacity due to acid rain.

Acid rain destroys the ecosystems, including streams and lakes, upsetting the delicate balance and making them unable to support life. It also can destroy forests, killing plant and animal life and eats away at man-made monuments and buildings, effectively destroying our natural and historical treasures.

While the 1990 amendments to the Clean Air Act have made great progress in reducing SO2 emissions from many of the midwestern coal power plants, more needs to be done. Too many of the lakes and streams in our country continue to suffer from the devastating effects of acid rain.


Power plants are one of the largest sources of toxic metal compound pollution. Together they released more than one billion pounds of toxic pollution in 1998, including 9 million pounds of toxic metals and metal compounds and 750 million pounds of dangerous acid gases. Many of these compounds are known or suspected carcinogens and neurotoxins and can cause acute respiratory problems, and aggravate asthma and emphysema.

One of the most dangerous toxins emitted is mercury. Coal contains trace amounts of mercury that are released into the air when the fuel is burned to produce electricity. The health hazard results when mercury falls to the earth with rain, snow, and in dry particles.

Mercury causes brain, lung, and kidney damage, as well as reproductive problems, and even death in humans and other animals. Mercury is found in fish after it falls into a lake or stream. Just one drop of mercury can contaminate a 25-acre lake to the point where fish are unsafe to eat, making mercury contamination the most common reason for fish advisories issued by States and Native American tribes. The EPA estimates that at least six million women of childbearing age have levels of mercury in their bodies that exceed what the EPA considers acceptable and that 375,000 babies born each year are at risk of neurological problems due to exposure to mercury in the womb.

Global Warming

Burning fossil fuels such as coal releases carbon dioxide (CO2) pollution. The US has four percent of the world's population yet emits 25% of the global warming pollution. Power plants emit 40% of US carbon dioxide pollution, the primary global warming pollutant. In 1999, coal-fired power plants alone released 490.5 million metric tons of CO2 into the atmosphere (32% of the total CO2 emissions for 1999). Currently there is 30% more CO2 in the atmosphere than there was at the start of the Industrial Revolution, and we are well on the way to doubling CO2 levels in the atmosphere during this century.

The 1990s were the hottest decade on record. Average global temperatures rose one degree Fahrenheit during the last century and the latest projections are for an average temperature increase of two to as much as ten degrees during this century. In February 2001, the Intergovernmental Panel on Climate Change (IPCC) reported that global warming threatens human populations and the world's ecosystems with worsening heat waves, floods, drought, extreme weather and by spreading infectious diseases. To address the problem of global warming, steps need to be taken to slash the amount of CO2 power plants emit. We need to switch from burning coal to cleaner burning natural gas and dramatically increase energy efficiency and renewable wind and solar energy.

What Can Be Done?

By the Government:

The government should expand the Clean Air Act to include protections from old and dirty power plants and provide incentives for the use of cleaner fuels. The government should also work towards the replacement of the existing infrastructure with a more sustainable means of producing electricity.

Congress is currently considering the Clean Power Act and Clean Smokestacks Act of 2001. These companion bills would dramatically cut power plant emissions for four major pollutants by 2007. Smog-forming nitrogen oxide emissions would be cut by 75%, acid rain-forming sulfur dioxide would also be cut by 75%, toxic mercury emissions would be cut by 90%, and carbon dioxide emissions would return to 1990 levels. In addition, the these companion bills would require every power plant to meet the most recent pollution controls required for new sources.

By Individuals:

Individuals can help by conserving electricity in the home and office by:

  • replacing incandescent light bulbs with compact fluorescent bulbs;
  • caulking and weather-strip doorways and windows;
  • installing low-flow showerheads and faucets;
  • keeping the furnace and air conditioner working properly;
  • buying energy-efficient electronics and appliances and make sure to turn them off when they're not in use;
  • raise awareness in the community by speaking with friends and neighbors and by; writing, faxing, calling and emailing to representatives in government and the President.
Source: Sierra Club Clean Air Program
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