Sulfur dioxide emissions from power plants across the U.S. fell 52% compared with 1990 levels, and they are already below the statutory annual emission cap of 8.95 million tons set for compliance in 2010 under the Acid Rain Program, the Environmental Protection Agency (EPA) reported last week. The EPA’s annual national analysis of the Toxics Release Inventory showed similar decreases by electric utilities for chemicals released into the air, land, and water.

The agency said in a new report that all 3,572 electric generating units subject to the program’s SO2 requirements held enough allowances to cover their SO2 emissions, resulting in 100% compliance in 2008. The total value of the SO2 allowance market at the close of the year was $2.9 billion with prices averaging $179 a ton.

Power plants released 7.6 million tons of SO2 last year, well below allowed emissions levels for the year. The declines were tagged to a growing number of scrubber units installed. These grew 20% to 295 in 2008 from 246 in 2007, the EPA said.

The EPA attributed the reductions to the Acid Rain Program, which was established under the 1990 Clean Air Act to reduce SO2 and nitrogen oxide (NOx) emissions from the electric power industry. The program set a permanent cap on the total amount of SO2 emitted and included provisions for trading and banking allowances.

Prices for allowances have plunged since a federal appeals court struck down the Clean Air Interstate Rule (CAIR).

The EPA’s 2008 Toxics Release Inventory showed that air emissions from electric utilities decreased nearly 5%, or 4,412 pounds, from 93,885 pounds in 2007 to 89,444 pounds in 2008. The agency said, however, that electric utilities reported the largest amount of air emissions of any industry sector, with 72% (89,444 pounds) of all air emissions of mercury and mercury compounds.

The database (PDF) contains information on 650 chemical releases (from more than 21,000 facilities in several sectors) into the air, land, and water, as well as waste management and pollution prevention activities.

Analysis showed that electric utilities had the second-largest total of toxic chemicals including lead, dioxin, and mercury in 2001 and 2008 (910 million pounds in 2008), but the sector also showed the second-largest decrease—of 161 million pounds, or 15%—from 2001. From 2007 to 2008, electric utilities reported a decrease of 10%, or 106 million pounds, the EPA said.

Decreases in 2008 from the sector included a 3% drop (more than 290,000 pounds) in lead releases and a 42% drop in air releases of dioxins. Total increases in surface water releases surged 3% in 2008, however, partially because of the coal ash spill at the Tennessee Valley Authority’s facility in Kingston, Tenn.

Source: EPA