Tennessee Valley Authority President and CEO Tom Kilgore, left, and TVA spokesman Mike Bradley, are shown leaving the federal courthouse in Knoxville, Tenn., on Wednesday, Sept. 21, 2011. Kilgore earlier testified at a trial on lawsuits seeking damages for the utility's Dec. 2008 coal ash spill in East Tennessee. (AP Photo/Bill Poovey)

TVA President and CEO Tom Kilgore, testifying Wednesday in the Kingston coal ash spill lawsuit trial, acknowledged TVA's responsibility for the safe operation of its facilities but admitted no blame on the part of the federal utility for the Dec. 22, 2008 environmental disaster.

Later in the hearing, an acknowledged expert on civil engineering, hydrology and dam safety, Dr. Bruce A. Tschantz, blasted the inspection TVA did on the coal fly ash holding cells at the Kingston fossil plant as severely lacking.

"It was a sham," he said.

Tschantz served on a Tennessee Department of Environment and Conservation advisory committee that examined lessons to be learned from the 2008 spill, which sent 5.4 million cubic yards of coal ash into the Emory River and onto surrounding countryside.

Jeff Friedman, attorney for some of the 230 plaintiffs suing TVA for property and health-related damages from the spill, questioned Kilgore on TVA's stated goals on observing regulations, protecting the environment and ensuring safety.

"I agree we have a responsibility to take care of our property so we don't impinge on our neighbors," Kilgore said.

Kilgore said TVA does its best but it is inevitable things will still go wrong.

"There is not a point where you can say that something out there can't happen," he said.

Throughout questioning, Kilgore was guarded in his comments as Friedman tried to get him to admit blame.

Friedman produced documents from the TVA Office of the Inspector General, in which consultant William Walton, hired by TVA to do a root cause analysis on the ash spill, said he was told by TVA to limit his investigation so as not to place blame on anyone at TVA. Kilgore said he never gave any such directive to Walton.

"I asked that we get the best or one of the best firms available to find out what happened and why it happened. That was simply my instruction," he said.

Friedman also pressed Kilgore on why no one had been fired or reprimanded in the aftermath of the Kingston disaster, although Kilgore had said TVA would do an appraisal of itself and hold people accountable. Kilgore said the agency has focused on improving policies and procedures as a result of what it has learned from the incident.

Plaintiffs' attorney Gary Davis put Tschantz on the stand as an expert witness to review TVA's ash cell inspection procedures. Tschantz is a professor emeritus in civil engineering at the University of Tennessee, developed courses at UT including on dam engineering and hydrology, and was the former head of the federal dam safety program and member of the TDEC advisory committee.

Tschantz said TVA engineers who conducted the last stability inspection of the coal ash holding area before the 2008 collapse noted surface erosion issues that were minor but failed to note signs of sinkholes, drop outs and other more serious signs of soil instability and include them in their report.

The dikes at the holding cells were essentially dams, and Tschantz said the TVA engineers inspecting them had no training or background in dam safety, there was no formal procedure for the inspection, the engineers were not prepped for what they were to do and they turned in their report late.