CHARLOTTE, N.C. (AP) -- Duke Energy Corp. and North Carolina environmental regulators have proposed a settlement in a lawsuit that said coal ash at a power plant threatens Charlotte's water supply.
The settlement calls for Duke to assess the sources and extent of contamination at the Riverbend power plant and also at a power plant in Asheville.
The settlement will be open for public comment for a month.
Duke would be fined $99,000 if the settlement is approved.
Jamie Kritzer with the North Carolina Department of Environment and Natural Resources Department says the settlement allows regulators to determine the extent of contamination before a plan is developed.
The Southern Environmental Law Center says the settlement does not go far enough, saying it allows more study of Mountain Island Lake on a problem that has been known for years.
The lake provides drinking water for 750,000 people.
Frank Holleman with the Southern Environmental Law Center said the order could have forced Duke to take immediate steps to stop the contamination.
"It gives Duke amnesty for its past pollution in return for a token penalty that amounts to a parking ticket for contaminating Mountain Island Lake," he said. "And it doesn't stop one ounce of pollution from entering that lake in the future."
Duke says its ash has not harmed the lake's overall water quality. It says seepage from the lagoons' earthen dams, cited by the state, is normal and doesn't indicate structural problems.