In a proposed order that will be open for public comment for 30 days, Duke agrees to assess the sources and extent of contamination at its Riverbend and Asheville power plants and will be fined $99,000 if the order becomes final.

In addition, if Duke fails to comply in a timely manner with any provision of the consent order, it will be subject to fines of $1000 per day for the first 30 days and $5000 per day thereafter for each violation.

The Mountain Island Lake near Charlotte is a source of drinking water for more than 750,000 people.

The agency alleges that Duke allowed toxic substances from coal ash stored in unlined lagoons at its Riverbend facility to leak into the lake, a nearby river and groundwater for years.

The NC Division of Water Quality filed a suit regarding pollution from Riverbend in May in response to a notice of intent to sue filed by the environmental law firm Southern Environmental Law Centre in March.

The state's claims were added to an existing suit dealing with the Asheville Plant, after contaminants from that plant flowed into the French Broad River.

The suit states that Duke's "unpermitted seeps" violate North Carolina law and the pollution "poses a serious danger to the health, safety, and welfare of the people of North Carolina and serious harm to the water resources of the state".

Testing by the Catawba Riverkeeper Foundation indicates that Duke is discharging arsenic into Mountain Island Lake in concentrations at least twice the applicable standard, cobalt at 52 times the standard, manganese at 128 times the standard and iron at 27 times the standard, according to SELC.

SELC and other groups fighting Duke’s pollution have come out in arms against the proposed settlement, saying it nowhere near reflects the damage done.

A state campaign finance watchdog claimed the settlement was particularly lenient because of the relationship between the company and Governor Pat McCrory, a former Duke executive.

The group called it “a remarkable sweetheart deal” and claimed it was softened by $1 million in campaign contributions from Duke to McCrory over the past five years.

Democracy North Carolina said McCrory’s 2008 and 2012 campaigns for governor received $308,836 from employees and former employees (and their spouses) of Duke and Progress Energy, which merged in 2012.

Duke’s and Progress’ political action committees donated another $24,000, it said.

The group said the companies also donated $761,800 in that period to the Republican Governors Association, which supported McCrory’s campaigns with $10.4 million in advertising and other spending.

“The cozy relationship between Duke Energy and the McCrory administration becomes clearer when you follow the political money.

“In addition to working at Duke for nearly 30 years, holding its stock and recruiting several Duke executives into his administration, McCrory has greatly benefited from the political contributions of

Duke Energy and Progress Energy,” the group said in a statement on Tuesday.

“McCrory’s Department of Environment and Natural Resources signed an agreement that delays remedial action, calls for more study of the pollution and fines Duke a piddling $99,112.

“Given Duke’s $19.6 billion in 2012 operating revenues, that’s the equivalent of fining a person with a $60,000 salary a total of 30c.”

Democracy North Carolina also reported campaign donations to Attorney General Roy Cooper and Mitch Gillespie, a former Republican legislator who is now an assistant environment secretary.

Federal regulations require that the state must provide the public 30 days to comment on the proposed settlement.