LAKE WYLIE — For more than a year, one Charlotte environmental group has warned of what could happen if coal ash ponds leak into local lakes. Now, they say, it’s happening.
The Catawba Riverkeeper Foundation on Thursday informed state and federal environmental regulators they’d discovered four seepage points, one into Lake Wylie and three into Mountain Island Lake. Along with recreational uses, Lake Wylie provides drinking water for York County and Belmont. Mountain Island Lake provides drinking water for Mecklenburg County.
“These leaks from the ash ponds are unpermitted, unhealthy and illegal,” Riverkeeper Rick Gaskins said. “They are of particular concern because the leaks discharge into drinking water reservoirs and because (Duke Energy) does not test the leaking material for hazardous constituents.”
Duke Energy manages the two power plants and the lake system. Company spokesperson Erin Culbert said seeps are treated “on a site-specific basis” but these are “extremely minute amounts” that shouldn’t be of major concern.
“Seepage is a normal function of a healthy engineered dam,” Culbert said.
Culbert said seepage points are “very common” and small ones “do not have any implications for dam integrity” other than, perhaps, a positive one. By relieving pressure, she said, seepage can help avoid a larger dam breach.
The Riverkeeper group says the leaks result from coal ash storage in unlined lagoons with earthen dams. Coal ash is a byproduct of energy production at coal powered plants. A “large seep” was discovered from Allen Steam Station on Lake Wylie from an ash pond dike and across a beach. The foundation found “at multiple points, free liquid is visibly seeping through exposed sediment.”
The foundation tested the material and found levels of barium, chromium, lead and selenium, Gaskins said. Similar findings were found on Mountain Island Lake near Riverbend Steam Station. There, results showed “a definitive coal ash signature” of arsenic.
Duke says regular testing of surface water and fish tissue show no ill-effects as a result of the seeps.
The contaminants were “not particularly surprising,” Gaskins said, since North Carolina allows Duke the use the opposite side of the river as a compliance boundary. The foundation is challenging that rule in a North Carolina Environmental Management Commission case. A hearing is set for Dec. 3.
Recent testing has shown drinking water is safe in both Lake Wylie and Mountain Island Lake, according to the utilities that use it.
Coal ash ponds have for many months been the topic of concern among environmental groups. In 2008, an ash pond failure in Tennessee caused widespread damage and prompted calls for increased regulation.