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CUMBERLAND MAIN ASH POND REPURPOSING
ENVIRONMENTAL

The hot and dry summer provides an opportunity for crews to make headway in converting the Main Ash Pond into a new lined Process Water Basin.

Barnard continues to work with the Tennessee Valley Authority (TVA) in converting the Cumberland Fossil Plant’s Main Ash Pond into two lined Process Water Basins (PWB). In the spring of 2022, crews removed the final loads of CCR from the Main Ash Pond and placed and graded that material in the temporary stacking area, where it received an intermediate cover cap. The majority of the earthwork was completed over the summer, with only subgrade finishing left within the new PWB. Currently, crews focus on installing the Basin Liner System, which will contain the rerouted process and storm water flows from the Plant. The Basin Liner System consists of three layers of geosynthetics and rock lined for long term protection.

OVERVIEW

Location: Cumberland City, Tennessee

Owner: Tennessee Valley Authority (TVA)

Design Engineer: Stantec Consulting Services, Inc.

Contract Type: Cost Reimbursable

HIGHLIGHTS

  • Installation of 630 wellpoints and 10 deep wells
  • Emergency stormwater pumping system capable of bypass pumping 15 MGD
  • Foundation treatment via moisture conditioning, bridge lift, or lime treatment of subgrade
  • Clean closure of 20 acres of the Main Ash Pond by removing CCR material and verification testing
  • Installation of an underdrain system to control ground water infiltration and heave
  • Construction of cast-in-place diversion structure
  • Temporary bypass pumping system capable of 143 MGD during tie-in work
  • Initial filling of Process Water Basin at 1 ft. per day

510,000 CY of CCR excavation and placement

100,000 tons of aggregate for the Basin Liner System

430,000 CY of structural fills, including soil liner

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