Taum Sauk Updates
Restoration Project: Taum Sauk Upper Reservoir Dam
	The Right Team to Safely Construct the New Dam
	AmerenUE announced on Nov. 7, 2007, that the company engaged Ozark Constructors, LLC, to rebuild the company’s Taum Sauk pumped storage hydroelectric plant upper reservoir. Ozark Constructors is a venture partnership formed by ASI Constructors, Inc., and St. Louis-based Fred Weber, Inc.    The company also announced that Paul Rizzo Associates, Inc., was selected engineer of record and project manager. RIZZO is a world-recognized engineering and construction management firm for dams. Read more in the news release.
	Illustration of the Taum Sauk Plant Upper Reservoir after rebuilding.
	Key Design Features
	Working with RIZZO 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.    Design highlights include:
		Dam Foundation The foundation will first be cleaned of all loose rock and soil. Then, the foundation will be thoroughly repaired, if needed, to create the most stable foundation possible.
		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.
		-	RIZZO, the contractor and an independent quality control testing firm, will conduct testing and inspection throughout the construction process to ensure that the dam material is of consistently high quality.
	Illustration showing a cross section of the rigorous RCC design for the upper reservoir of the Taum Sauk Plant.
		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 will be dedicated to dam safety.
		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 peer-review groups.
		Other Safety Features Well-trained personnel will be critical to the project’s success, and AmerenUE and RIZZO have worked with FERC to develop a new dam safety program and an extensive design review process, all emulating industry models.
	Ameren’s Dam Safety Program
	In 2006, AmerenUE established a robust dam safety program that has been approved for the FERC. The dam safety program is intended to ensure that Ameren’s employees, agents and consultants have a complete understanding and constant awareness of the need to fully comply with all necessary dam safety measures and requirements.    To accomplish this mission, AmerenUE created an organization of professionals who are independent of daily operators. The chief dam safety engineer leads this multi-disciplinary team of engineers dedicated to engineering and managing ongoing upgrades, conducting safety and other operational inspections and implementing safety improvements at company plants.    The chief dam safety engineer is also responsible for communicating policies and expectations regarding dam safety and regulatory compliance and for monitoring compliance with FERC dam safety-related requirements. This includes the use of sound and prudent engineering practices and notification to the FERC about any condition affecting the safety of a project or any modification to a project.    The chief dam safety engineer is also charged with implementing quality management initiatives―from documenting dam inspections to establishing qualification standards to dam inspection personnel. He has the authority to conduct unannounced facility inspections and take corrective actions―up to and including shutdown―if dam safety is threatened.
	Illustration shows the design for the overflow release structure that would be used in the highly unlikely event of over-topping.