Tags:Elevated arsenic levels have been found in a preliminary sampling of water and sediment collected downstream from Progress Energy's Skyland power plant and coal-ash pond. A water sample taken from an unnamed French Broad River tributary nearby contained arsenic at slightly above the permissible level for surface waters -- and seven times higher than the U.S. Environmental Protection Agency's limit for drinking water, says Steve Patch, director of UNCA's Environmental Quality Institute. Patch and a research assistant also collected a sediment sample that yielded a more alarming arsenic level of 258 parts per million.
That's more than 15 times arsenic's "probable effect level" -- the point at which a toxic element frequently has negative effects on organisms -- as opposed to its "threshold effect level," at which organisms might experience negative effects but rarely do, he explains. The naturally occurring arsenic level in U.S. soils, notes Patch, averages about 5 ppm.
According to fact sheets issued by the EPA and other federal agencies, arsenic is a recognized carcinogen, and exposure can cause stomach irritation, liver damage, skin discoloration and other problems. At high exposure levels, it can kill. Arsenic is also a byproduct of coal combustion that's found in coal ash.
The Environmental Quality Institute, founded about 20 years ago by chemist and environmental advocate Rick Maas, focuses on arsenic, lead and mercury research, Patch says, providing data and other support to citizens, organizations and regulators as well as offering educational-outreach programs. "A lot of environmental issues are statistical," says Patch, who's taught statistics at UNCA since 1985 and who worked closely with Maas, who died in 2005. Patch has co-authored more than 40 publications on water quality, ecology and exposure to environmental toxins.
The Skyland study was spurred by the disastrous coal-ash spill near Kingston, Tenn., on Dec. 22, 2008. Patch's interest was also sparked by a query from Xpress in early January concerning water-quality monitoring near Progress Energy's coal-ash pond.
The 42-acre pond stores the wet ash produced by burning coal and by the process that removes particulates and toxins from the leftover gases. Built in 1982, the pond isn't lined. Water from it drains into a second, smaller collection pond that allows more coal ash to settle out. After that, the water flows out through a culvert that travels under Interstate 26 before emptying into the French Broad (see Green Scene, Jan. 14 and 21 Xpress).
Progress Energy has a wastewater permit for that discharge, state Division of Water Quality officials confirm. The agency, notes Asheville-based Environmental Officer Jeff Menzel, recently conducted its own water sampling at the plant but hasn't yet gotten the results back from the lab. Reports dating back to 2002 show no evidence of violations or trends that would trigger further investigation, says Menzel.
Nonetheless, says Patch, if the pond isn't lined, contaminants will leach out. Aided by research assistant Melissa Kline, a UNCA student, Patch reviewed topographic maps to discern which tributaries might be most affected by any leaching. In mid-January, the two canoed to selected sites on the French Broad and four tributaries, both upstream and downstream from the plant. At each site, they collected a number of water and sediment samples.
The institute and its affiliate, the Volunteer Water Information Network, have conducted a variety of tests near the Progress Energy plant over the years, Patch mentions, including fish-tissue sampling to check mercury levels. A 2003 study at Lake Julian -- an artificial lake whose water is used by the plant -- detected no mercury in sampled fish, Patch recalls. But low levels of both lead and arsenic have shown up in French Broad fish caught downstream in Tennessee and in other sampling projects, he adds.
The January 2009 test results, however, leave Patch wishing he had the funding to conduct further study. Although the contaminants appear to be sufficiently diluted by the time they reach the French Broad so that the utility isn't violating federal standards, some toxins are reaching the river and are contaminating at least one stream, he emphasizes.
Is the contamination coming from the coal-ash pond? Is it affecting aquatic life in the stream?
At present, Patch can't answer those questions, but he'd like to. "We've done a fair amount of soil sampling in this area [over the years], and we've never found anything close to 258 ppm," he notes, adding, "That's not natural."
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