PROJECT SCOPE

This 100-acre ash pond closure began with a strategic and complex dewatering approach that required several dewatering systems to be online and operational prior to the start of the closure. In addition to the plant processing waters being channeled through the pond, it also had substantial influences from the adjacent river and groundwater.

For additional storage and treatment, CBP constructed environmentally secure compacted soil / HDPE lined ponds with concrete fabric-formed protection. The system was equipped with multiple pumping stations and over 10,000 feet of HDPE piping. Once these were in place, CBP’s next water management task was to create an adequate series of rim ditches and canals to allow the perched and surface waters within the ash pond to flow to several strategic pumping locations. These stations would then pump the contact water to an adjacent polishing pond for treatment and release to the river.

Two additional methods that we used were well points with limited success and a much more beneficial process of mechanical stimulation of the ash that proved in this pond to be very beneficial. Although these efforts require strategic planning and tireless maintenance, they allowed CBP to maintain good progress with the ash excavation and quicker recovery after significant weather events.