SC 133 Bridge over Lake Hartwell
Pickens County, SC

The SC 133 Bridge over Lake Hartwell, built in the 1950s, was woefully outdated. As part of a major thoroughfare to Clemson University, the bridge was not only too narrow for current traffic demands, it had become structurally unsound, too.

Given its projections that traffic to and from Clemson University would only grow heavier, the S.C. Department of Transportation had to act.

The department chose Mulkey to conduct the final design and construction plans for a replacement structure over Lake Hartwell.

Mulkey’s replacement bridge will be wider, providing an additional lane of traffic and wide shoulder for each direction. And the new structure will prove much safer for many generations of commuters to come – with eight 53’-9” spans, Type II AASHTO girders founded on drilled shaft bents, and abutments founded on steel piles.

Ever mindful of its client’s needs, Mulkey’s bridge design team investigated several superstructure alternatives and presented them to S.C. Department of Transportation officials to ensure that the most economically feasible structure was carried into final design.

To make certain drivers continue to reach their destinations while the bridge is constructed, Mulkey designed a detour around the bridge site. This project also includes the redesign of an existing interchange to improve traffic flow. The design required detailed roadway and hydraulic work, as well as a signalized intersection design (Madden Bridge Road & Pike Road), from the Mulkey team.

During final design, Mulkey’s environmental experts discovered that the project was located in one of the U.S. Environmental Protection Agency’s “Superfund” sites. The EPA study indicated that an industrial hazardous waste, polychlorinated biphenyls (PCBs), had been dumped in the lake bottom. Testing is being done to determine the contamination concentration level and appropriate disposal method. Construction will involve encasement of lake soil to ensure that any PCBs will be properly disposed of before drilling shaft foundations.

The Mulkey team is proactively collaborating with the S.C. Department of Transportation, the S.C. Department of Health & Environmental Control, the U.S. EPA and the U.S. Army Corps of Engineers’ lake management officials to get the construction effort finished as close to the original schedule as possible.

Said one project manager from the S.C. Department of Transportation of Mulkey: “Consultant has been very proactive on this project and has done a good job coordinating and communicating with DOT.”