Eyewitness News met Eric Crabbe as he was enjoying his night on the water at Mountain Island Lake.
"I live down the road, come here fishing a couple times a week," he said.
Eyewitness News has learned that the state has filed a lawsuit against Duke Energy, over that water.
"The lawsuit alleges they are violating the law by having illegal discharges into Mountain Island Lake," said Rick Gaskins, the Catawba Riverkeeper.
Gaskins says Duke Energy built coal ash ponds near Mountain Island Lake. That is where it used to dump ash from its old coal plant.
Duke was allowed, by the state, to dump some of that water into Mountain Island Lake, so the ash ponds wouldn't overflow. But the state lawsuit alleges that more water got into the lake, from unpermitted locations.
Gaskins says Mountain Island Lake is the source of drinking water for more than 860,000 people. He says the drinking water is safe right now because it's purified by the city.
But he is worried about what could happen if what is in the ash continues to build up in the water. He says it could impact the sediment, the fish, the plants. Now that the coal plant is shut down, he would like to see the ash ponds removed for good.
"Dig them up, take them away, put them in a lined landfill where these hazardous constituents won't continue to leech out into peoples drinking water," said Gaskins.
Duke Energy released a statement Tuesday saying, "We are reviewing the filing and believe we have diligently complied with Riverbend's Water Discharge permit. We appreciate the State's desire to obtain as much information as possible related to discharges to Mountain Island Lake and groundwater, and we expect to work closely with them on this matter."
The company also says it has been monitoring the water quality on the lake for decades and it says the water quality is good.
It says the volume of the ash basin seepage is small and is needed to maintain the dam's structural integrity.
Duke Energy says it has routinely let the state known about seepage happening at the basin dams.