Texas power plants tops for mercury emissions

Mercury emissions from power plants remain flat despite the availability of the technology to cut back on the dangerous toxin, according to a report released today by the Environmental Integrity Project.

Texas has five power plants in the top 10 list of worst emitters of mercury, according to the study. Leading the pack: Luminant's Martin Lake power plant in Rusk County, which reported a 4.56 percent increase from 2007 to 2008 (the most recent data available).

Other Texas-related findings in the report:

• Dallas-based Luminant (formerly TXU) has three of the nation's top five largest mercury emitters, in terms of total pounds emitted, all operating in East Texas. Luminant's Big Brown power plant reported a 32.89 percent increase from 2007 to 2008.

• In Texas, just four Luminant power plants -- Martin Lake, Monticello, Big Brown, and Sandow 4 -- reported 5,259 pounds of mercury emissions in 2008, or almost 6 percent of all mercury reported nationwide. Two new Luminant plants currently under construction in the state -- Oak Grove and Sandow 5 -- are expected to come on line in 2010 and are permitted to emit up to 1,632 pounds of mercury a year.

• NRG's Limestone County plant, located about an hour east of Waco, emitted 1,251 pounds of mercury in 2008, a 4.55 percent increase over its reported 2007 emissions. NRG is currently constructing a third coal-fired boiler at this plant.

Interestingly, NRG's W.A. Parish plant, located south of Houston in Fort Bend County, saw its mercury emissions drop 7.75 percent from 2007 to 2008.

Mercury emissions don't need to be as high as they've been at the nation's power plants, according to the report:

Sorbent injection, which can achieve mercury reductions up to 90 percent from coal-fired power plants, has been proven by more than 30 full scale demonstrations performed by the U.S. Department of Energy, Electric Power Research Institute, and the utility industry. Existing power plants can be retrofitted with sorbent injection with little or no downtime and with a capital cost of between $1 and $3 per megawatt hour.

In addition, mercury can be significantly reduced as a "co-benefit" of pollution controls for other key pollutants like particulate matter, sulfur dioxide, and ozone-causing nitrogen oxides. Mercury is removed as a co-benefit of controlling these pollutants through the use of fabric filters, sulfur dioxide scrubbers, and selective catalytic reduction.