TVA contractors have dug up and hauled away half the coal residue that spilled into the Emory River last December from a ruptured ash pond at the Kingston Fossil Plant.

But TVA President Tom Kilgore said Tuesday that removing the stain on TVA’s reputation from one of America’s worst industrial spills will take more than hydraulic dredgers and rail cars.

“We’re challenging the culture at TVA,” Mr. Kilgore said during a meeting with reporters and editors at the Chattanooga Times Free Press. “When I look at Kingston, it certainly can be argued that we missed some red flags.”

The TVA president conceded that agency employees through the years didn’t raise enough questions, pay enough attention to details or spend enough money to maintain its aging fleet of coal plants or their method of wet ash storage. Like a repentant sinner, Mr. Kilgore said TVA “has to ‘fess up to the problem and get it cured.”

“The Good Book says whoever covers their sins won’t prosper, but somebody who confesses them can get rid of them,” he said. “We’re trying to change the behavior of our employees so that, when they have concerns, they speak up and we need to get those concerns elevated so that we can properly address those concerns.”

Mr. Kilgore said the removal of half of the 3 million cubic yards of ash and muck that spewed into the Emory River “is a good milestone for us” and he vowed to have all of the ash out of the river by early next summer.

The coal ash is being shipped to a lined landfill in Perry County, Ala.

“Everybody told us to get it out of the river fast, and we feel pretty good about that,” he said.

Next year, TVA will lead a process to determine what should be done with the other 2.4 million cubic yards of coal ash that spilled over about 300 acres in Kingston. That ash could be dug up and removed or capped and covered to reuse the land for parks, recreation or other uses, Mr. Kilgore said.

Internal auditors and outside consultants have criticized TVA for not paying enough attention to employee warnings about leaks and potential problems from a half century of ash stored behind an earthen dam that rose 60 feet above the Emory River in Kingston.

Audits also found that TVA managers dismissed preliminary plans for dry ash storage at Kingston seven years ago in favor of the cheaper alternative of building more wet ash storage ponds.

But not addressing the problems has proven far more costly for TVA. The utility estimates it will spend from $933 million to $1.2 billion to clean up the Kingston spill over the next couple of years. Another $2 billion likely will be spent to convert all six of TVA’s coal plants that use wet ash storage to dry ash disposal methods.

TVA is spreading the costs of those investments over several decades, but the expense this year was a key reason the utility raised its base electric rates by 8 percent on Oct. 1, officials said.

Mr. Kilgore said he hasn’t “found anyone at TVA who I would say was culpable” and should be fired for the Kingston spill, although he conceded that “we didn’t have accountability clearly aligned” in the agency’s management.

To some neighbors of the Kingston plant, whose lives and properties were upset by the ash spill, that isn’t enough.

“I no longer trust what TVA says and, at this point, I think Tom Kilgore should be fired,” said Sandy Gupton, who owns a 250-acre farm in Kingston and is suing TVA for damage to her property from the spill. “We had water on our pasture until September because the river was clogged with ash and we had to go elsewhere to water our cows. But TVA withdrew its offer to negotiate the purchase of our land that they damaged.”

TVA has spent more than $40 million to buy 140 properties around the Kingston plant this year, and Mr. Kilgore said the agency still may buy other properties.

“We’re trying to rebuild trust with the people we serve one step at a time,” Mr. Kilgore said. “I can’t undo the problem, but if I fix the problem, I know we’re going to be much better than we were before.”

To help avoid a repeat of the Kingston disaster, Mr. Kilgore appointed Bob Deacy as a senior vice president for coal byproducts to focus on coal ash problems. The TVA president also created a corporate governance and compliance office headed by former TVA Controller John Thomas and hired another communications senior vice president, David Mould, to improve community relations.

TVA also is paying the business consulting firm of McKinsey & Co. up to $5 million to assist in restructuring its processes.