Established in 2012, Eagle Rock Concrete is a start-up ready-mixed concrete producer headquartered in Raleigh, NC. For their main operations, they chose to build a new ready-mix batch concrete plan on the site of a former concrete and asphalt crushing operation in Wake County. The facility consists of a material storage area and yard, a truck wash-down facility, a drum rinse-out area, and the concrete plant itself. WithersRavenel designed the plant’s wastewater collection system to fully capture, store, and reuse industrial runoff using a closed loop design, which protects that environment from harmful runoff contamination while saving the plant money by reducing the amount of water and material lost in the course of normal operations.
The design incorporates a detailed surface grading plan that prevents non-industrial stormwater and wastewater commingling while directing all surface wastewater toward three ramped wash-out chambers. Overflow concrete flume openings offset in each chamber basin provide extended detention settling time and allow suspended material to be captured and reclaimed. Sloped ramps allow for easy access by heavy equipment to recover settled material for reuse. To minimize clogging and provide better long-term site maintenance, no underground stormwater piping is used in the industrial plant yard area.
Within the industrial footprint of the plant, the wastewater collection system also captures and stores surface runoff from a 25-year 24-hour design storm event. Since moisture control is essential to optimum performance in the manufacturing process, the industrial stormwater is reused for aggregate hydration and in the batching process.
WithersRavenel involved Eagle Rock owners and managers throughout project development, construction monitoring, and post-build follow-up and closeout. The design, construction, and operation of the process water recycling system is as cost-effective a solution as possible to meet permit requirements. Project estimates were within tolerance in meeting budget. All phases of the project were produced on time and within budget.