The Public Service Commission staff blames management problems at Ameren for the Taum Sauk reservoir collapse. The report calls the dam collapse an avoidable accident. The collapse sent a billion gallons of water down Taum Sauk Mountain into the Johnson’s Shut-Ins State Park. It occurred December 14, 2005.
The report submitted to the full commission by the PSC staff is 85 pages long. It states that "the plant was customarily operated with an insufficient margin of safety". It found that the water level sensors had broken free from their anchoring system, which made them unreliable, and that the emergency back-up sensors, intended to prevent a breach in the reservoir dam, had been improperly set too high.
The staff writes that the breach as "entirely avoidable" in that Ameren knew for more than two months that the water level sensors had broken free from their anchors.
PSC Chairman Jeff Davis says the full commission is studying the report and will decide what actions should be taken.
Ameren, which is based in St. Louis, has 90 days to respond to the report. In a memo sent to the Missourinet, Ameren states, "…there is nothing in this report that has not been analyzed over the last 22 months and in the previous five investigations conducted by state and federal authorities." An Ameren spokesman says that a preliminary review of the recommendations indicates the utility has fully adopted or is in the process of adopting many of the recommendations.
Ameren points out that the PSC staff found that there was no tampering of evidence as alleged by Chief Dam Safety Engineer James Alexander. The statement provided to the Missourinet also says that if Ameren decides to rebuild the plant, it will meet or exceed the highest safety standards.
The Taum Sauk collapse could have been much worse. It occurred in December, the off-season for Johnson’s Shut-Ins. Still, the flood wiped out the park superintendent’s residence and injured the family. The park has been under repair and opened for limited use this past summer.