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Is coal ash poisoning Charlotte-area drinking water?

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But Jimmy Knowles from the South Eastern Fly Ash Group says the industry has overcome coal ash-related stigma in the past. In the 1970s, he says, the product he wholesales for companies like Duke Energy was known as "fly trash." His customers didn't like the idea of including trash in their products, so orders slipped. But because it costs a third to half the cost of comparable alternatives, they eventually got over it. Incidentally, he also says the same people who didn't like the word "trash" are now balking at the word "hazardous." When asked if the impending regulations have hurt his business, he says, "There's been a downturn in the whole U.S. economy, so it's hard to say." Like Duke Energy, Knowles' company is in favor of federal regulation for coal ash but not if it means reclassifying it as hazardous waste. Although he acknowledges: "It has the potential to become hazardous if it's mismanaged."

Of course, not all coal ash can be re-purposed. Whether it can be or not depends on the waste management technology at each individual plant. Riverbend, the 80-year-old Duke Energy coal plant on Mountain Island Lake, is not one of the plants that produces the type of coal ash that can be re-purposed in concrete or asphalt manufacturing. Instead, the two unlined, high-hazard ponds behind the plant hold the waste until the ponds are too full to accept any more, then they're drained into the lake and excavated. The sludge, which looks a lot like lava, is then piled around the plant's property, or sold as cheap landfill, and seeded with grass.

Most wastewater is subject to treatment before it's released into area waterways for use by the next downstream municipality. But the tainted water pouring out of Riverbend's ponds, at a rate the company estimates to be many millions of gallons per day, isn't treated at all — even though wastewater (like the stuff you flush) and other debris from the plant is also pumped into the ponds. Additionally, data collected by both Duke and Progress Energy indicate the groundwater beneath every unlined coal ash pond in the state is contaminated. But because the collection of such data is deemed voluntary by both state and federal regulators, and because it hasn't been collected for very long (only since December 2008 at Riverbend), there isn't enough data to determine whether or not the contamination is getting better or worse.

Besides mucky ponds soaking in our groundwater and discharging into our lakes, there's another way coal ash can contaminate water. When it's used as cheap landfill beneath buildings, parks, golf courses and any number of other construction projects, it's easier for stormwater to carry coal ash — and everything in it — into area waterways. Because coal ash is currently not regulated at all by the federal government and only minimally by some states, there are no safeguards for such practices.

Charlotte Mecklenburg Utilities and Mecklenburg County test our water for substances like arsenic before it's treated and pumped into homes and businesses. According to their tests, the water's fine; however, no one seems to know where all of the heavy metals go. The likely answer is that they're stuck in the sediment at the bottom of the lake, which is the second smallest on the Catawba River and only 17 feet deep at its deepest. That's because gravity is the treatment for coal ash wastewater. The job of a coal ash pond is to hold the water for a few days while gravity does its work, ideally, pulling the heavy metals to the bottom of the ponds.

Unfortunately, not all of the metals sink. According to Duke Energy's recordkeeping, which is sometimes shared with the N.C. Department of Environmental and Natural Resources, 1-3 pounds of arsenic are discharged from the ponds behind Riverbend into Mountain Island Lake every day, depending on how much electricity the plant is producing to meet our demands. Currently, the state does not limit the amount of arsenic the company is allowed to discharge into the lake and calls that type of monitoring "voluntary," too. But that could change. The plant's discharge permit expired in February and the new five-year permit is currently under review.

Both Duke Energy and Mecklenburg County conduct periodic sediment sample tests and claim the sediment's fine as well — or at least the amounts of heavy metals they find aren't illegal. This summer, Merryman, our Riverkeeper, also conducted sediment testing in Mountain Island Lake and found it contains arsenic, barium, lead, selenium and mercury. This is of concern because the shallow lake is also used for recreational purposes and fishing. Which means boat motors and feet can stir up the sediment, reintroducing it — and whatever's in it — back into the water.

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