Earlier this month, the Federal Energy Regulatory Commission authorized AmerenUE to resume normal project operations at the project, with FERC Regional Engineer Peggy Harding writing to the utility: “Through participation in all phases of the design and construction of this project and as a result of our review of all documentation provided in support of your request, you may begin normal project operations.”

AmerenUE provided FERC a final design and construction report dated March 24 that included certifications from the utility and its design engineer and quality control manager that the project was constructed as designed and in accordance with approved plans and specifications. It also submitted a dam performance and instrumentation report that detailed the satisfactory performance of the rebuilt upper reservoir during a test refill program in March.

AmerenUE reported it completed a successful test March 20 of the upper reservoir level control and protection system, which is designed to provide adequate and redundant safeguards to ensure safe operation through the reservoir’s full range of operations.

Paul C. Rizzo Associates Inc., AmerenUE’s design engineer and quality control manager, provided FERC a commissioning notice to operate the project March 26.

Ozark Constructors – a a venture partnership formed by ASI Constructors Inc. of Pueblo West, Colo., and St. Louis-based Fred Weber Inc – rebuilt the upper reservoir under the guidance Paul C. Rizzo Associates Inc. Other firms that worked on the project included PayneCrest Electric and Communications, Haberberger Inc., B&P Construction, Castle Contracting and Tarlton Corp.

According to AmerenUE, about 1,000 employees were engaged at some point over the course of the project.

Taum Sauk has not operated since the reservoir’s mountaintop ring dam breached on 14 December 2005, when 5.9B litres of water from the plant’s upper reservoir flooded Johnson’s Shut-Ins state park and nearby roads.

The rebuilt reservoir project is currently the largest RCC dam in North America, and was recently named the recipient of the Award of Excellence in the Constructed Project during the US Society on Dams 2010 Annual Meeting and Conference.