State: Duke must test water near ash ponds
By Bruce Henderson-Charlotte Observer-Wednesday, Feb. 03, 2010
Duke Energy must test groundwater around ash ponds at its coal-fired power plants, state officials say, as scrutiny of the waste grows.
Burning coal leaves millions of tons of ash, which holds potentially toxic metals that can taint groundwater, rivers and lakes. A burst dam buried a Tennessee community in ash sludge in 2008, and state and federal enforcers are tightening their oversight.
Duke has already found contaminated groundwater near its ash ponds. Now the state wants to know how far the contamination extends.
The N.C. Division of Water Quality, for the first time, will make Duke test groundwater as part of water permits coming up for renewal at its three Charlotte-area coal plants. The permits now address only discharges of water from the ash ponds into local lakes.
The permit for Duke’s Riverbend plant on Mountain Island Lake expires Feb. 28. The permit for the Marshall plant in Catawba County is up April 30 and Allen’s, on Lake Wylie, is up May 31. None have records of recent water-quality violations.
But Catawba Riverkeeper David Merryman said the state hasn’t previously focused enough scrutiny on the ash ponds to know whether they’re safe.
Duke voluntarily drilled groundwater sampling wells near its ponds. The state allows some leeway around the ponds - the contaminated groundwater found in some of those wells aren’t considered violations of safe-water standards.
All the ponds at Duke’s plants showed contamination, Appalachian Voices, a Boone-based environmental group, reported in October. So did the ponds of Progress Energy of Raleigh.
The state now wants Duke to install wells farther from the ponds, to learn whether contamination has spread. Duke says the state has proposed wells on what’s called the compliance boundary, 250 to 500 feet from the wells.
“The state’s interest is that groundwater meet (state) standards outside the compliance boundary,” said Debra Watts, a state groundwater official.
Duke spokesman Andy Thompson said the utility agrees with the state proposal.
“We feel like the state is well positioned to protect the public health and to ensure that we’re having a minimal impact,” he said.
But riverkeeper Merryman, called the state’s plan a “baby step” that needs to go further.
“Really we need wells on the border of the property,” he said, “and if there’s contamination they need to look outside the boundary.”
Merryman also worries about what flows from Riverbend’s ash ponds into Mountain Island Lake, the drinking water source for Charlotte, Gastonia and Mount Holly.
Coal ash mixed with water is piped into one large pond, where heavy particles settle to the bottom. Water then flows to a lower pond, which discharges 2.8 million gallons daily into the lake.
Riverbend’s state discharge permit requires Duke to report the amounts of two toxic elements, arsenic and selenium, it releases.
But it doesn’t place limits on either. Merryman calculates that Duke dumps 1 pound of arsenic a day into Mountain Island.
Duke doesn’t have to test for other metals in Riverbend’s discharge.
“All those things we know are in coal, they’re not being tested for,” Merryman said. “There’s no reason that facility should be discharging into the same water supply that nearly 1 million people use.” Read entire article.