KNOXVILLE, Tenn. — Plaintiff attorneys who contend that the Tennessee Valley Authority should pay damages for the Kingston Plant coal ash spill cross-examined a TVA consultant who testified Friday that he was hired to find the "mechanics" of the cause, not to place blame.
Geotechnical engineer William H. Walton was on the witness stand for a second day at the federal bench trial on damage lawsuits by property owners who contend that TVA negligence in training, operations and construction caused the December 2008 disaster.
Walton testified Friday that TVA hired him as AECOM USA Inc.'s chief investigator to determine "why the structure failed." He said he was not hired to determine any TVA management or operational problems.
"I conducted a probable failure modes analysis," Walton said of his work investigating the spill and preparing the report in 2009.
The nation's largest public utility is trying to avoid lawsuit payouts from the spill of about 5.4 million cubic yards of ash into the Emory River and on a Roane County river community about 35 miles west of Knoxville after an ash pond breached. Along with a $1.2 billion cleanup that is costing ratepayers an average of 69 cents a month each until 2024, TVA has bought 889 nearby acres for $46.6 million.
TVA previously said it had bought more than 180 properties and settled more than 200 other claims from people living near the spill.
Walton answered questions about his report, which partly blamed the storage pond spill on a "slime layer" of ash deep underneath the surface. His report said the slime tended to move and add hydraulic pressure to the dikes. He described it as being like yogurt, seeming to be stiff until it is stirred.
The chief of TVA's watchdog agency, TVA Inspector General Richard Moore, has criticized Walton's report, saying it did not address TVA failures to heed advance warnings about the storage pond and did not take into account management issues as a possible cause.
Moore has testified that he stands by his criticism that the consultant's report failed to consider management practices and placed too much of the blame on the slime layer.
Another study said the spill "could have possibly been prevented" if TVA had heeded concerns raised previously by TVA employees and consultants about the stability of the ash pond.
Walton, whose study for TVA cost $3 million, testified that he has since received other TVA contracts and is being paid about $180,000 for his testimony as an expert.