Pennsylvania Deptartment Of Environmental Protection [This story printer-friendly]
May 31, 2006

MERCURY CONCENTRATES NEAR COAL-BURNING POWER PLANTS

Data Collected Over Eight Years Show Mercury Levels 47% Higher In Areas Near Power Plants Results Add to Body of Scientific Work Demonstrating Mercury 'Hot Spots'

HARRISBURG -- Sample results from Pennsylvania's two longest-running mercury deposition collection sites reinforce other state and national studies that show the neurotoxin tends to concentrate around local emission sources, creating "hot spots" of contamination. Data collected over eight years by Penn State University for the Department of Environmental Protection show mercury levels 47 percent higher in areas closer to power plants.

"Several independent studies have shown how local efforts to control mercury protect public health, improve air quality and clean the environment," DEP Secretary Kathleen A. McGinty said.

"The data show that if Pennsylvania wants to protect the unborn, young children and other vulnerable populations, mercury needs to be controlled at its source," McGinty said.

The data were collected at two sites -- Cresson in Cambria County and Wellsboro in Tioga County -- between 1997 and 2004. The sites were selected because of their significantly different profile relative to locations to nearby coal-fired electric generating stations.

The Cresson site, which is fairly close to and downwind of a number of large coal-fired electric utilities in southwestern Pennsylvania, reported an average wet deposition rate of mercury that was 47 percent higher than results collected at the northern tier monitoring site. Wellsboro is at a much greater distance from any coal-fired utilities.

A year-by-year breakdown of the results in nanograms per liter (ug/m2):

1997 1998 1999 2000 2001 2002 2003 2004 8-Yr.Avg.

Cresson 10.863 9.767 8.985 8.854 11.933 9.596 11.628 11.233 10.36

Wellsboro 7.217 7.500 6.853 7.599 4.929 6.214 7.838 8.343 7.06

Penn State's eight years of sampling results for DEP add to the body of scientific work already completed on mercury deposition.

In February, research funded by the U.S. Environmental Protection Agency showed that nearly 70 percent of the mercury collected at an Ohio River Valley monitoring site originated from nearby coal-burning industrial plants. Conducted over two years in Steubenville, Ohio, the study is the first in which scientists used rain samples and meteorological data to track mercury from smokestacks to monitors.

An earlier EPA Office of Water study found local sources within a state commonly contribute more than 50 percent to 80 percent of the mercury deposition.

Last month, Massachusetts reported a 32-percent average decrease in the level of mercury found in a signature freshwater fish, yellow perch, caught in nine lakes in the northeast corner of the state, where a cluster of incinerators is located. The reductions came seven years after the state enacted the nation's toughest mercury emission laws for incinerators. Comparatively, yellow perch from lakes elsewhere in the state recorded a 15 percent drop on average.

Massachusetts' Department of Environmental Protection Deputy Commissioner Arleen O'Donnell said in published reports officials were stunned by the dramatic turnaround.

"We weren't expecting to see such drastic reductions in such a short time frame," she said. "This is really significant because this is a cumulative toxin -- the thought was it took a long time to get this high in the environment and it was going to take a long time to reverse it."

Other studies have had similar findings. A Florida Everglades study showed that mercury concentrations found in fish and wading birds there dropped by 60 to 70 percent due to local mercury emission reduction efforts.

Pennsylvania has a compelling case for seeking a state-specific rule that cuts mercury emissions faster and more substantially than EPA's Clean Air Mercury Rule.

The commonwealth has 36 coal-fired power plants with 78 electric generating units that represent 20,000 megawatts of capacity. These units accounted for approximately three-fourths of the more than 5 tons of mercury emitted into the air from all contamination sources in the commonwealth, ranking us second only to Texas in terms of total mercury emissions.

According to the latest Toxic Release Inventory report, which EPA released April 12, Pennsylvania moved from third to second in the total amount of EGU-specific mercury emissions in 2004. The commonwealth had been third behind Texas and Ohio, respectively.