Case Study: AECOM Process Technologies designed an innovative, lower-cost solution to bottom ash dewatering that allowed a coal-fired power plant to comply with both the CCR Rule and updated ELGs.
AECOM worked with a midwestern coal-fired power plant to replace a pond-based bottom ash sluice system with a continuous-flow, concrete dewatering tank (CDT) from which ash can be removed with an excavator with the system in service. Through careful design and with appropriate chemical addition, the clarified ash transport water can be reused for ash sluicing while complying with discharge restrictions.
AECOM was responsible for engineering and design services, procurement of engineered equipment, and support for construction, commissioning and startup. Despite the COVID-19 pandemic, the system was completed within budget and began operation in advance of the compliance date, with all performance guarantees met. The resulting system provided a solution for regulatory compliance that required a lower capital investment than the market alternatives.