A new report says four main causes led to the catastrophic Tennessee Valley Authority (TVA) fly ash spill that dumped a devastating 5.4 million cubic yards—over one billion gallons—of toxic coal sludge into Tennessee’s Emory and Clinch rivers and the 300 acres surrounding the TVA Kingston plant. According to KnoxNews, William Walton, AECOM engineer, and TVA’s Chief Operating Officer, Bill McCullum, recently discussed the report.
In addition to a layer of unstable ash sludge—“slimes”—that went undetected, the “construction of retaining walls on top of the ash,” “saturation of the stored ash,” and “pressure exerted by rising stacks,” led “to this problem,” said Walton, who added that, “It’s almost a perfect storm,” quoted KnoxNews. Walton said the slimes were “comprised of fine particles of fly ash, water, and sediments underneath the ash stacked in one area of the pond,” explained KnoxNews, which noted that Walton compared the consistency to that of yogurt. (more…)