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Closure of an Ash Storage Facility at Kingston Thermal Plant

Helping a power utility to restore public confidence following an environmental disaster

  • $1.2B

    Project Budget

  • 10

    Miles Slurry Walls

  • 230AC

    Geosynthetic Cap

  • Kingston, Tennessee

    Kingston, Tennessee

Restoring the environment after a disaterous fossil plant failure

Tennessee Valley Authority’s (TVA) Kingston Fossil Plant supplies power that is critical to the regional economy. For over 50 years, coal ash by-products were stored in ponds and wet stacks along the Emory River. A failure in 2008 released over 5 million cubic yards of ash, impacting 40 residences, destroying a public highway, and closing the river. In response, we quickly mobilized to assist TVA with emergency actions.

Designs to stabilize the site and support construction of critical infrastructure were prepared for the recovery. This included extensive instrumentation and a monitoring program to verify stable conditions during rapid stacking of recovered ash. Concurrently, engineering designs were developed for the site closure. Regulations required the recovered ash stack withstand a 2,500-year seismic event. Our team realized that widespread liquefaction would occur within the foundation ash and native silt/sand layers during such an event; thus, foundation improvements were required.

A sophisticated, dynamic numerical simulation of the facility was completed for the design earthquake event, in addition to conventional ground response, liquefaction, slope stability, and 3D structural analyses. Our solution of a stabilized perimeter consisting of buried, cement-bentonite slurry walls keyed into bedrock at depths up to 70 feet does not require dewatering. The largest wall of its kind in the U.S. at nearly 64,000 linear feet—the equivalent of 12 miles—it is designed to withstand a magnitude 6.0 earthquake. More than 200,000 tons of cement and other materials were used. The new capped facility contains roughly 12 million cubic yards of coal ash produced by the power plant over the last six decades including ash recovered from the 2008 failure.

We are proud to have worked with TVA to close the site and restore the environment shared with their neighbors.

At a Glance

Offices
News
Recovery at Kingston
Award
ACEC Engineering Excellence
Award
American Council of Engineering Companies of Kentucky - Engineering Excellence Awards, Grand Award
Meet Our Team

Adam Crace, Principal, Geotechnical Engineering

I enjoy waking up every day to a new challenge, whether it’s drilling a geotechnical boring or safely executing an underwater inspection.
Adam Crace Principal, Geotechnical Engineering Read More

Jeff Dingrando, Principal, Geotechnical Engineering

I enjoy opportunities where we can bring value to our clients, exceed their expectations, and separate ourselves from the competition.
Jeff Dingrando Principal, Geotechnical Engineering Read More

Alan Rauch, Vice President, Discipline Lead, Water (Geotechnical)

I am immensely satisfied when our technical knowledge and hard-earned experience lead to elegant solutions for complex problems.
Alan Rauch Vice President, Discipline Lead, Water (Geotechnical) Read More

Angus McGrath, Principal Geochemist

I believe in being open-minded about potential solutions, looking at alternative technologies, and finding the best solution for each site.
Angus McGrath Principal Geochemist Read More
  • Adam Crace

    Principal, Geotechnical Engineering

  • Jeff Dingrando

    Principal, Geotechnical Engineering

  • Alan Rauch

    Vice President, Discipline Lead, Water (Geotechnical)

  • Angus McGrath

    Principal Geochemist

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