Wastewater treatment system for 4 units to economically meet 2020 Effluent Limitation Guidelines while maintaining unit fuel flexibility

Santee Cooper Cross Generating Station FGD Wastewater Treatment System

When Santee Cooper, the largest power plant in South Carolina, needed to meet effluent limitation guidelines (ELG) set by the Environmental Protection Agency, they set out to implement a wastewater treatment system that would be flexible. The goal? To continue to operate and provide power with variable fuel sources while maintaining air emissions and wastewater effluent.

We completed the project’s define phase including an alternatives analysis, preliminary design, and cost estimate. In the execution phase, we’re providing specifications, finalizing design, and supporting construction and startup activities. One important consideration was the inclusion of bench and pilot testing for worst-case scenarios as the system’s chloride concentration surpassed previous biological treatment system operations and—depending on which units were cycled in service—the quality of the wastewater to be treated varied significantly.

Renewable energy sources are not always available or sufficient. This upgrade will supplement power on demand to provide economical and uninterruptible service to over a million households—all while meeting air and water quality standards.