The largest electricity generating utility in the United States, American Electric Power, as agreed to pay billions to cut pollutants regulated under the Clean Air Act by two-thirds over the next decade. The $4.6 billion settlement with the EPA and others ended the company's legal battle which began in 1999.

The Columbus, Ohio - based electricity giant agreed to install $4.6 billion in pollution-control measures at 16 existing plants and pay $75 million in penalties. The anti-pollution systems at the 16 plants it has expanded over the years will effectively remove  more than 813,000 tons of pollution from the air annually by 2018. The plants will emit 79 percent less sulfur dioxide and 69 percent less nitrogen oxides, as compared to 2006 emissions.

"Today's settlement will save $32 billion in health costs per year for Americans," said Granta Nakayama, Assistant Administrator for EPA's enforcement and compliance assurance program. "Less air pollution from power plants means fewer cases of asthma and other respiratory illnesses."

AEP claims that most of the settlement money had already been dedicated to installing pollution control equipment. The company said that the present value of the additional installations is $1.6 billion and that the 10-year investment will not affect its current bond rating or its projected capital expenditure program. However, American Electric Power did not want to admit any wrongdoing.

Moreover, AEP managed to insert in paragraph 133 of the agreement a section that assures AEP that the government will not pursue any action stemming from the "modification" of these plants between now and Dec. 31, 2018. This was opposed by the other plaintiffs, who instead mentioned in paragraph 140 they could again sue the utility over violations of the law.

Federal officials from the EPA "have written in the ability for AEP to violate [the law] in those plants for the next 10 years," alleges Natural Resources Defense Council senior attorney John Walke.

The U.S. Environmental Protection Agency was joined in the case as plaintiffs by eight states: New York, New Jersey, Massachusetts, Vermont, Connecticut, New Hampshire, Maryland, and Rhode Island; and many citizen groups: Natural Resources Defense Council, National Wildlife Federation, Sierra Club, United States Public Interest Research Group, Izaak Walton League of America, Ohio Citizen Action, Citizens Action Coalition of Indiana, Hoosier Environmental Council, Ohio Valley Environmental Coalition, West Virginia Environmental Council, Clean Air Council, Indiana Wildlife Federation, and the League of Ohio Sportsmen.

Last April, the U.S. Supreme Court issued a ruling that now forces utilities with older coal fired plants to pony up for new technologies if they upgrade to produce more power.

American Electric Power serves parts of 11 states and also owns and operates the Donald C. Cook nuclear power plant in Bridgman, Michigan. The company was founded in 1906 and is reportedly the 35th-largest corporate producer of air pollution in the United States, with roughly 88 million pounds of toxic chemicals released annually into the air (per a 2006 study by scientists at the University of Massachusetts Amherst).