Missouri utility AmerenUE said Nov. 7 it hired joint venture Ozark Constructors LLC to rebuild the breached upper reservoir of the 408-MW Taum Sauk pumped-storage project.
Taum Sauk (No. 2277) has not operated since the reservoir’s ring dam breached Dec. 14, 2005, releasing 1.4 billion gallons of water down the Black River, injuring nine people, and damaging property. A Missouri Public Service Commission investigation cited a failure of utility management for the breach. (HNN 10/26/07)
AmerenUE said Ozark Constructors is a joint venture of Colorado-based heavy civil contractor ASI Constructors Inc. and St. Louis-based Fred Weber Inc., which works in mining, aggregate processing, and heavy civil construction.
The utility said it also selected Paul Rizzo Associates Inc. as engineer of record and project manager. Rizzo designed a roller-compacted-concrete replacement dam that has been approved by the Federal Energy Regulatory Commission.
AmerenUE said it only can rebuild the upper reservoir if it can successfully resolve outstanding issues with the state. It expects the plant to remain out of service through at least the fall of 2009.
It said insurance should cover substantially all of the cost to rebuild the project.
The Missouri Public Service Commission staff issued a report Oct. 24 blaming utility management for the failure.
�The breach was entirely avoidable in that the company knew for over two months that the water level sensors were unreliable, as they had broken free from their anchoring system, but unaccountably failed to make repairs,� PSC staff said. �This failure was a management failure in that 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.�
The reservoir was overtopped when pumps failed to shut off. Once overtopping began, erosion undercut the rockfill dam and soon formed a breach about 656 feet wide at the top of the dam and 496 feet at the base. The reservoir was emptied within 25 minutes.
PSC staff: Ratepayers should not pay rebuilding costs
The PSC staff asked the state regulatory commission to adopt proposed recommendations, including one that stipulates all costs associated with the Taum Sauk incident are to be excluded from AmerenUE’s electricity rates.
Additionally, the staff recommended appropriate accounting treatment be given to monies expended to rebuild Taum Sauk, to protect the interests of Missouri ratepayers. AmerenUE, an Ameren company, also could be required to submit its accounting treatment for all transactions related to project reconstruction.
Gov. Matt Blunt said the 85-page report affirms Ameren acted inappropriately and is responsible to the state. He said Missourians should not pay for Ameren’s conduct, which he labeled as misconduct. Ameren has a responsibility to fully compensate the state for loss, he added.
The Federal Energy Regulatory Commission authorized AmerenUE in August to begin rebuilding the upper reservoir. (HNN 8/16/07)
Missouri, Ameren close to settlement in civil case
The governor said officials have been working diligently on a settlement of the case that is in the best interest of Missouri, tough on Ameren, and provides fair compensation for the people of Reynolds County, in eastern Missouri.
A civil suit brought by the state attorney general against AmerenUE seeking costs, expenses, penalties, and damages is pending in Reynolds County Circuit Court, but is reported to be close to settlement, PSC staff said.