In a sweeping legal settlement, the Tennessee Valley Authority has agreed for the first time to reduce its overall capacity to generate coal-fired electricity, promising to close 18 of its coal-burning generators over the next six years while spending $3 billion to $5 billion on pollution controls on any remaining units that use coal.
The accord, announced Thursday by the Environmental Protection Agency, will bring about one of the most significant cuts in coal-fired power generation by any utility that relies heavily on coal in its fuel mix. The closings will eliminate 16 percent of the authority’s coal-fired capacity, and the accord holds out the prospect that some or all of another 18 units will shut down as well, for a total loss of as much as a third of the authority’s coal-burning capacity.
By the end of 2017, the utility’s emissions of nitrogen oxides, a crucial component in smog and ground-level ozone, will be reduced by at least 69 percent, and sulfur dioxide emissions will be cut by 67 percent, the E.P.A. said, compared with 2008 levels. Sulfur dioxide can react with other compounds to form ultrafine particles, which are associated with heart and lung disease.
The actions dictated in the sweeping 120-page settlement, reached with four states and three environmental groups that sued the T.V.A. over air pollution, signal a fundamental shift for an agency that was created during the Depression to bring electricity to rural America In the 1960s and ’70s, it became one of the largest users of coal in the utility industry. Coal makes up more than half of the fuel that the utility burns to generate electricity for nine million people.
Emissions from coal-fired plants have been implicated in respiratory illness, acid rain and, most recently, climate change. “This agreement will save lives and prevent billions of dollars in health costs,” the E.P.A. quoted its administrator, Lisa P. Jackson, as saying.
The agency estimated that the actions would avoid at least 1,200 premature deaths and prevent hundreds of cases of bronchitis and nonfatal heart attacks, as well as 21,000 asthma attacks.
Roy Cooper, the attorney general of North Carolina, which originally sued the T.V.A. in 2002 to rein in its pollution, said in an interview, “This is what we wanted — a broad-based agreement for the reduction of pollution from all its plants.”
“It’s been a long time coming,” Mr. Cooper said. Alabama, Tennessee and Kentucky were also part of the settlement.
Besides a commitment to shutter 18 coal-fired generating units, the utility said that the additional 18 units being scrutinized, representing 4,600 megawatts of capacity, would be retrofitted with pollution controls, closed or reconfigured to burn a renewable fuel like wood or crop waste.
Beyond the health impact of coal plant emissions in recent decades, there have been significant environmental changes in places like Great Smoky Mountains National Park, which straddles North Carolina and Tennessee. Since the 1970s, pollution-related haze has greatly reduced visibility — although there have been improvements in recent years — and the chemical pollutants brought to earth by raindrops have sickened some plants and shrubs.
In a statement, Tom Kilgore, the T.V.A.’s president, said the authority was moving to diversify its energy portfolio. “A variety of electricity sources, rather than heavy reliance on any single source, reduces the long-term risks and helps keep costs steady and predictable,” he said.
The organizations that intervened in the states’ case were the National Parks Conservation Association, Our Children’s Earth Foundation and the Sierra Club. Mary Anne Hitte, the director of the Sierra Club’s “Beyond Coal” campaign, called the settlement “a game changer for how we power our homes and businesses in the Southeast.”