RESTON, Va. — After setting a North American record for the most roller compacted concrete placed in a single day — 18,590 cubic yards — Columbia, S.C.’s Saluda Dam Remediation Project has been honored with the American Society of Civil Engineers’ 2006 Outstanding Civil Engineering Achievement award.

The OCEA award recognizes the project’s significant contribution to the civil engineering profession and its local community.

“South Carolina Electric & Gas Co. officials were faced with an extraordinary challenge when they realized the impact a repeat of the 1886 Charleston earthquake could have on Columbia’s three-quarters-of-a-century-old Saluda Dam,” ASCE President Dennis R. Martenson said. “Their proactive approach to protecting the surrounding communities, and the innovative methods they implemented to achieve that goal, make this project the embodiment of everything for which the OCEA award stands. We are proud to honor the Saluda Dam Remediation Project with this year’s award.”

When SCE&G officials learned their 1.5-mile-long, 200-foot-high Saluda Hydroelectric Project dam embankment could liquefy during a repeat of the 1886 Charleston earthquake, they knew something had to be done. However, whatever solution they developed had to keep a 78-square-mile reservoir rimmed with homes and businesses nearly full and keep a hydroelectric plant and coal-fired steam plant operational, all the while ensuring the safety of the 120,000 residents living in the floodplain. The result was a 1.3-million-cubic-yard RCC backup dam with zoned earthen abutments.

The project’s challenges prompted the patenting of a method of expeditiously placing filter zones and the design of a cooling method to enable concrete production during extremely high temperature. It also required utilization of on-site waste ash and quarried aggregates, as well as the removal of roughly 10 million cubic yards of material. Because of the volume required, finding materials proved challenging, and ultimately, on-site borrow sources proved the best option. A rock quarry was designed to utilize available gneiss rock formations while avoiding schist formations and the on-site coal-fired steam plant served as a source of fly ash. The benefit to the project was the use of 150 pounds of fly ash per cubic yard of RCC, resulting in the use of approximately 200 million pounds of on-site waste ash.

The project faced numerous challenges, including considerations for the local community. Lowering Lake Murray to rebuild the dam would have had unthinkable social and economic impacts, but the backup dam would have to be founded on dense soil or rock and some areas would require extensive excavation — as much as 60 feet below existing grades. However, the toe of a 200-foot-high, active dam is a very dangerous place to dig.

Extraordinary measures were required to maintain public and worker safety while retaining the 78 square miles and 750 billion gallons of water that make up Lake Murray. The only practical means to improve excavation slope stability was through intense dewatering efforts. In total, 94 deep wells, 43 shallow wells and 824 educator wells were installed to lower the ground water and to improve stability of the existing dam during construction.

Due to the array of environmental concerns the project created — protecting surrounding wetlands and a trout stream, etc. — full-time environmental engineers were included in the project staff to take a hands-on approach to staying within regulations. Winner of the Engineers’ Society of Western Pennsylvania’s 2003 Heavy Construction Project of the Year award, the project also, whenever possible, arranged work activities around residents’ schedules. For example, all blasting was done at lunch time when it was least disruptive to the neighbors. A sprinkler system and water truck were also installed to ensure dust arising from the three onsite batching plants and other activities could be immediately mitigated.

The project, owned by SCE&G, was led by Paul C. Rizzo Associates, Inc., with Barnard Construction Company serving as contractor. Subcontractors included: Kleinfelder, Griffin Dewatering Southeast, H. B. Mellott Estate and Hayward-Baker/Nicholson JV.

Merit finalists for the 2006 OCEA award included two other South Carolina- based projects, the Liberty Bridge in Greenville, and the Arthur Ravenel Jr. Bridge in Charleston, in addition to the Neutrinos at the Main Injector Project in Batavia, Ill. and Soudan, Minn., and the Bridge Apollo in Bratislava, Slovakia.

Established in 1960 by ASCE, the OCEA program recognizes projects on the basis of their contributions to the well-being of people and communities, resourcefulness in planning and design challenges, and innovations in materials and techniques. Selected from a group of 20 entries, the 2006 winner and merit finalists are outstanding examples of how civil engineering can contribute to a community’s economic success, improve residents’ quality of life and facilitate scientific advancement.

Previous winners include the relocation of the Cape Hatteras Lighthouse, the Trans-Alaska Pipeline and the World Trade Center Towers.

The OPAL awards honor outstanding projects and professional civil engineers for lifelong contributions in five categories: public works, construction, management, design and education.

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