Taum Sauk Updates
Key Dam Safety Features
Working with Paul C. Rizzo and Associates, AmerenUE has determined that the safest method of rebuilding the upper reservoir would be to use a roller compacted concrete (RCC) design. This design would employ the latest in overflow structures, monitoring and control systems, seismic design criteria and other safety features.    Here are some highlights:
	Dam Foundation: The foundation would first be cleaned of all loose rock and soil. Then, the foundation will be thoroughly repaired, if needed, to create most stable foundation possible for the new dam.
	RCC Dam: The RCC Dam is designed to satisfy the current guidelines published by the Federal Energy Regulatory Commission (FERC) and to meet industry standard dam safety engineering practices. In addition:
	-		The design has been peer-reviewed and critiqued by Ameren’s dam safety group, Ameren’s independent Board of consultants, FERC’s staff, FERC’s own independent panel of consultants, and other FERC regional office staff members.
	-		Extensive testing has been conducted using the actual mix components planned for Taum Sauk Plant. Construction would only proceed based on the satisfactory results of engineering studies.
	-		Rizzo, the contractor, and an independent quality control testing firm would conduct testing and inspection throughout the construction process to ensure that the dam material is of consistently high quality.
	Dam Crest: The crest elevation would be two feet above the highest anticipated water surface. In addition, with the exception of the overflow release structure that is two feet above the water surface, there will be a three-and-one-half foot wall above the dam crest to protect against potential wave action.
	Overflow Release Structure: Modern standards require such an overflow release structure that is not expected to ever be used but that will be in place in the highly unlikely event that all systems fail and the upper reservoir overflows.
	Monitoring and Control: Multiple, independent lines of defense—including continuous video camera monitoring of the upper reservoir water levels—will ensure that proper water levels are maintained in both the upper and lower reservoirs. Separate instrumentation and control systems would be dedicated to dam safety. Continuous video camera monitoring of the upper reservoir water levels, as well as a redundant monitoring and control system, will be put in place to safeguard against any potential over-pumping.
	Seismic Design Criteria: The re-built project is designed to accommodate the most recent seismic design criteria and will be designed to withstand potential ground shaking from both near-field and far-field earthquake events up to a 2,500-year return period. The seismic design basis has undergone significant review by the five groups mentioned above.
	In addition to these many structural features, well-trained personnel will also be critical to the project’s success. That’s why AmerenUE and Rizzo have also worked with FERC to develop a new dam safety program and extensive design review process that are industry models.