GAO: Scrubbers slash power plant mercury

WASHINGTON, Oct. 8 (UPI) -- Sorbent-injection scrubbers cut mercury emissions at 14 U.S. coal-fired power plants by 90 percent, the U.S. Government Accountability Office said Thursday.

The GAO said in a report that the sorbent-injection systems used at 14 plants enabled them to meet various state mandates for mercury reductions.

"Importantly, the substantial mercury reductions using these systems commercially and in tests were achieved with all three main types of coal and on boiler configurations that exist at nearly three-fourths of U.S. coal-fired power plants," the report said.

The 491 coal-fired power plants in the United States are the leading source of mercury emissions in the nation, annually producing about 48 tons of the toxic heavy metal.

Sorbent-injection scrubbers are seen by the Department of Energy as a promising technology since they cost an average of $3.6 million per plant, which is low compared to other types of emission-control equipment.

The GAO said some plants had been able to reduce mercury pollution with their existing emissions control equipment; however other plants will need scrubbers as well as additional steps such as coal blending.