Pollution controls don't prove as costly as critics forecast

Breathing easier in the Valley

A look at TVA emission levels compared to levels during peak periods:› Sulfur dioxide is down 98 percent from the 1978 peak.› Nitrogen oxide is down 94 percent from the 1995 peak.› Carbon dioxide is down nearly 50 percent from the 2005 peak.Source: Tennessee Valley Authority

America's biggest public utility has completed the closing and cleanup of its aging fleet of coal plants to comply with clean air requirements and has done so while keeping power rate increases below the rate of inflation.

When the Tennessee Valley Authority reached a settlement with the U.S. Environmental Protection Agency and environmental groups in 2011 to clean up its power generation, coal industry advocates warned closing fossil plants would push up power rates and cut jobs in TVA's seven-state region.