PSC: Taum Sauk collapse was Ameren management failure

ST. LOUIS -- The Taum Sauk reservoir collapse was an avoidable accident that resulted from management problems at Ameren Corp., a report released late Wednesday by the Missouri Public Service Commission said.

The report marks the conclusion of a PSC investigation that began this summer. The investigation involved testimony of several Ameren officials and employees from the Taum Sauk plant.

To prevent similar accidents, the report recommends the St. Louis-based utility make a number of companywide management changes, including assigning one official to oversee safety at all the company’s power plants.

PSC chairman Jeff Davis said Wednesday that he hadn’t read the whole report, but he noted the investigation indicated Ameren managers did not intentionally tamper with evidence when they removed safety probes at the reservoir the day of the collapse.

Delayed repairs of faulty instrumentation caused the mountaintop reservoir to breach Dec. 14, 2005, sending more than 1 billion gallons of water rushing down over Johnson’s Shut-Ins State Park. The deluge injured a family and devastated much of the park.

“This failure was a management failure,†the report said. “Ameren had organized the operation of its plants and the performance of maintenance, repair and improvement activities at its plants in such a way that overall direction was lacking and crucial information was not shared.â€

Ameren spokeswoman Susan Gallagher said late Wednesday the company had not had time to exhaustively review the 85-page-report.

“However, a preliminary review indicates 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,†Gallagher said in an e-mail.

The company has 90 days to file its response to the report’s conclusions and recommendations.

Ameren is currently involved in settlement negotiations with state agencies to compensate the state for damages from the collapse. Gallagher said the company already has paid $40 million to clean up damage from the accident.

A key focus of the PSC investigation was the placement and removal of crucial backup safety probes at the reservoir, which was automatically filled with water each night. The probes were designed to stop the automatic filling if water got too close to the top of the reservoir walls and threatened to overflow.

The probes were set so high that water never touched them the morning the reservoir overflowed and collapsed.

Davis said this summer a big reason he wanted to launch the investigation was to find out why the probes were moved to an unsafe level, and why Ameren employees removed them the day of the collapse.

The report says the probes were moved a year before the collapse by Taum Sauk manager Jeffry Scott and Tony Zamberlan, a contractor working for Ameren. The report says they moved the probes to the final, unsafe level where they were eventually found.

The report says there was no documentation of resetting the probes, but that Ameren engineer Tom Pierie said they were likely raised because waves often hit them and cause false alarms.

The probes were removed the day of the collapse by Pierie and Ameren employee Rob Scott at the direction of James Witges, whom Pierie identified as supervisory engineer at Ameren.

Missouri’s top dam safety official told the PSC the probes should not have been removed immediately after the reservoir collapse. James Alexander, Missouri Department of Natural Resources dam safety chief, said officials might never know if the probes were properly set the morning of the accident because they were removed.

Davis said he now thinks Ameren managers were simply trying to test the probes, and not trying to tamper with evidence in the reservoir collapse.

“I don’t think there was anything malicious behind their decision to do that. I think they were just concerned with what happened,†Davis said.

Alexander did not return a message left at his office Wednesday evening.