Design-Build Mine Water Treatment Plant
HDR was the design engineer for a design-build team that completed the largest mine water treatment system in the U.S. in 2010 — a two million gallons per day (mgd) Zero Liquid Discharge (ZLD) water treatment system at an underground coal mine in Virginia. The plant receives water from coal mine dewatering operations needed to keep nearby longwall mines operational. The plant also serves dual purpose as a water supply facility, by returning the treated effluent to the coal preparation plant.
The project objectives were to simultaneously dewater a flooded inoperable mine seam and to treat the water for subsequent reuse in nearby coal washing operations. A secondary goal of the project was to further process the salt removed from the saline water to process it into commercially viable road salt for beneficial reuse.
HDR's scope of work consisted of civil, structural, electrical, process and mechanical design. HDR's structural engineering tasks included the design of building foundations, deep auger cast piling foundations for heavy thermal equipment, steel platforms for process equipment and steel pipe rack systems. Detailed process design efforts consisted of unit process connection and integration to assist the technology provider, design of filter cake and dried salt conveyor systems, design of the chemical storage and metering facilities and detailed pipe design for the clarification, water tank, filtration and dewatering areas of the facility.