For the timely and effective closure of Coal Combustion Residual (CCR) impoundments, there is no substitute for experience. Keller provides engineered construction services for new and existing impoundments (construction, closure, and remediation), geotechnical enhancements (dam rehabilitation, slope stabilization, dewatering, karst, etc.), water management (diversion, unwatering, dewatering, passive and active treatment, OM&M), and slope stabilization.

Sector challenges we can solve

Ash dewatering/drainage to facilitate excavation and ash removal, regrading and capping, or a “hybrid” approach
Geostructural improvements in ash with jet grouting, soil mixing, or conventional earth retention

Working with Keller, you get a solution tailored to the site-specific conditions to meet the project objective. We have performed the following scopes of work that at coal-fired power plants and fly ash ponds:

  • Dewatering for fly ash stabilization and rapid excavation
  • Installation of temporary earth support within ash for CCR excavation
  • Groundwater cutoffs within ash
  • Treatment of ash pore water
  • Dewatering for dam seepage mitigation
  • Environmental encapsulation with deep and shallow soil mixing technologies
  • Storage pond/dike and embankment stabilization
  • Instrumentation and monitoring programs for monitoring key indicators such as pore pressures and ground (ash) movements during construction activities

Each site is unique due to differences in pond construction, degree of saturation, and geologic and ash deposition conditions. Keller has worked on more ash ponds than any other specialty geotechnical contractor. These have included ash ponds impounded in low permeability soil and those stored directly in contact with shallow high permeability aquifers, all with different ash properties (depending on layering and its overall particle size distribution).