Arapahoe Station Coal Combustion Residual Pond Closure

Our team successfully excavated and disposed of more than 421,000 tons of coal and fly ash from a high-visibility decommissioned power plant located near the heart of downtown Denver.

Driven by EPA regulations for the management of coal combustion residuals (CCR), our client, a large Colorado utility provider, was required to remove all infrastructure and waste from their decommissioned Arapahoe Station coal-fired power plant. With plans to market the 50-acre property for future development, the client turned to us for the excavation and closure of six coal ash ponds.

As part of this effort, our team performed the excavation and off-site disposal of more than 421,000 tons of coal and fly ash from the site. Located in a logistically challenging area adjacent to the South Platte River, we coordinated more than 19,000 loads of material for disposal in a nearby Subtitle-D landfill through a transportation subcontractor.

Once all waste was removed, our team performed final grading and construction of 1,200 linear feet of surface water controls and 260,000 square feet of infiltration ponds. In total, the final site regrading required the cut and fill placement of more than 580,000 cubic yards of backfill material – enough to fill more than 175 Olympic swimming pools.