The Dirtiest of the Dirty Power Plants

It's that time of year when people compile Top 10 lists—10 best of this, 10 worst of that, 10 best funny cat videos, 10 worst campaign ads (which presupposes the questionable assumption that there are any good campaign ads).

Just in time for the coffee table book season, the North American Commission on Environmental Cooperation has published an online volume (Spanish and French versions also available) detailing the air emissions of some 3,000 power plants in the U.S., Canada, and Mexico—the three parties to the NAFTA trade deal that has a lesser-known environmental side agreement that spawned the commission.

The document, which details top 10 lists for power plants in each of the three countries, is a treasure trove for pollution voyeurism, although the data is of 2005 vintage, the most recent year the commission could pull together information from across the continent. Being parochial, we'll let our Canadian and Mexican readers explore the emissions profiles of their countries' champion power plants. Here in the U.S., the winners, all of them coal-fired, are:

Carbon dioxide - Top spot belongs to the mammoth Scherer facility near Macon, Ga., a 3,520-megawatt plant owned by a group of Southeastern utilities. Scherer emitted more than 23.4 million tons of CO2 in '05. Going full blast, Scherer burns nearly 1,300 tons of coal per hour. But Scherer's CO2 emissions rate—tons per megawatt-hour—was not the highest. Within the top 10 for CO2, that honor goes to Westar Energy's 1,857-megawatt Jeffrey Energy Center, a plant burning Powder River Basin coal north of Topeka, Kansas, that powered out 1,086 kilograms of CO2 per megawatt-hour.

Mercury - The top emitter was Luminant's 1,880-megawatt Monticello plant in northeast Texas, which burns mostly lignite, a low-grade coal variety, but also throws some higher quality Powder River Basin coal into the mix. A total of 977 kilograms of mercury went out Monticello's stacks in '05.

Sulfur dioxide - Georgia Power's 3,500-megawatt Bowen plant, north of Atlanta, released more than 169,000 tons of SO2, an acid precipitation and particulate precursor, back in 2005. Scrubbers went operational at Bowen three years later with the goal of knocking SO2 emissions down by 95 percent, so the commission's numbers don't reflect the better news coming out of Bowen.

Nitrogen oxides - The 2,040-megawatt Four Corners coal plant, located on Navajo land in northwestern New Mexico and owned by a consortium of Arizona, California, New Mexico, and Texas utilities, released 37,870 tons of NOx, another acid precipitation and particulate precursor. Four Corners is the focus of a legal battle over its emissions; a coalition of tribal and environmental organizations filed suit two months ago under the Clean Air Act's New Source Review provision to force plant owners to install NOx controls.

There's more data for numbers junkies to trawl through in an interactive database here. Meanwhile, I'm going Christmas shopping. Don't think I'll be buying any books about coal for the kids' stockings, however.