MECKLENBURG COUNTY, N.C. - A 9 Investigation found high levels of arsenic were discovered in Charlotte's main source of drinking water, Mountain Island Lake.
Channel 9 was first to report the story Wednesday on the WSOC-TV app.
Mecklenburg County water officials said they tracked the toxins back to Duke Energy's coal ash pits.
In January, Duke Energy started taking steps to drain the coal ash pond at the Riverbend Steam Station, and that discharge feeds into a cove on Mountain Island Lake. In June, tests found arsenic levels at the highest rate they've been in the twelve years since the county started monitoring the lake.
Catawba river keeper, Sam Perkins, is pleased Duke is closing its coal ash ponds but concerned about the amount of arsenic being released into local lakes.
"The last thing we need to be doing is adding a significant amount of arsenic back into the region's primary reservoir of drinking water," Perkins said.
But that is what water quality tests found.
The state standard for arsenic levels in the lake is 10 parts-per-billion. In June, monthly tests near the Riverbend Station found arsenic at 95 parts-per-billion, which is nearly 10 times the standard.
Eyewitness News anchor, Brittney Johnson, asked county officials if Duke is responsible for those higher levels.
"The arsenic is originating at the coal ash basins, yes," Environmental Quality Program Director, Rusty Rozzelle, said.
A Duke Energy spokesperson told Channel 9 they regularly monitor the water, and started noticing a rise in arsenic levels in March. They stopped draining the pond once the county alerted them to the high levels in June.
"We continued to operate within the levels of our permit, and as a precautionary measure, we have stopped work at this time," Zenica Chatman said.
The company is expecting a permit later this year that will allow it to have arsenic levels of 72. 5 ppb as water goes through the drainage pipes. Arsenic levels jumped to 150 in June.
Duke Energy and county officials are adamant the arsenic did not impact drinking water. Charlotte Water officials confirm any toxins from the coal ash would be filtered out and kept away from the drinking water supply.
The county retested the water near Riverbend four days after finding the alarming levels of arsenic and the levels dropped below the standard.
Duke Energy is building a treatment system to help solve the problem and says they will resume work when it's complete in September. A team from the North Carolina Department of Environmental Quality will visit the lake Thursday to take samples and analyze them for arsenic. The state has not determined if Duke Energy will face any enforcement action.
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