Changes

A report released in late June 2009 identified the main factors contributing to the massive Kingston coal ash spill. TVA hired engineering firm AECOM to analyze the underlying causes of the spill. According to the report, the underlying layer of the coal ash sludge was unstable and went undiscovered for decades by previous TVA stability analyses. The "creep failure" of this layer and liquefaction of the ash triggered the spill. The report also identified other factors including the construction of terraced retaining walls on top of the wet ash, which narrowed the area for storing the ash and in turn increased the pressure exerted by the rising stacks. Engineer Bill Walton said these factors created a "perfect storm" leading to the Kingston disaster. AECOM's report discounted heavy rains and seismic activity as contributing causes.<ref>Scott Barker, [http://www.knoxnews.com/news/2009/jun/26/report-four-factors-led-to-fly-ash-spill/ "Report: Four factors led to fly ash spill,"] ''Knoxville News Sentinel,'' June 26, 2009.</ref><ref>[http://www.wbir.com/news/local/story.aspx?storyid=91400&provider=top "Fly ash pond too high, filled too fast,"] WBIR, June 25, 2009.</ref>

On July 28, 2009, TVA's Inspector General Richard Moore released a report concluding that the agency had improperly directed AECOM's investigation into the causes of the Kingston spill in order to protect itself from lawsuits. Moore criticized the decision to allow TVA's attorneys to hire the consultant and narrow the report in a way that "predetermined the choice that would be made between accountability and litigation strategy." As a result, the report overemphasized an underlying layer of slimy ash as the trigger for the collapse, an explanation Moore said was intended to reduce the legal culpability and liability of TVA management. According to Moore, "it appears TVA management made a conscious decision to present to the public only facts that supported an absence of liability for TVA for the Kingston spill." The report also revealed internal agency memos about warnings that could have prevented the spill, and suggested that other TVA sites may be at risk of similar collapses.<ref name="tenn">Bill Theobald, [http://www.federaltimes.com/article/20090728/AGENCY03/907280304/-1/RSS "TVA schemed to avoid blame in spill, report says,"] ''Federal Times,'' July 28, 2009.</ref>

Also in July 2009, consultants McKenna Long and Aldridge of Atlanta released a report commissioned by TVA following the massive Kingston spill. The report cited widespread problems with how the federal utility deals with its coal ash storage, saying that the controls, systems, and corporate culture required for proper management of the coal ash sties at its power plants were not in place. According to the consultants, TVA had no standard operating or maintenance procedures prior to the spill and neglected to provide annual training for its safety inspectors.<ref>Duncan Mansfield, [http://www.oakridger.com/breaking/x1885905608/TVA-consultants-criticize-coal-ash-operations "Report blasts TVA on coal ash storage after spill" ] Oak Ridger, July 21, 2009.</ref>