Geosyntec has had a strong and continuous involvement in engineering projects at TVA Kingston since the 2008 geotechnical failure. Our involvement includes the following and serves as a demonstration of our experience with coal combustion residuals (CCR) management, disposal, and associated activities:
Post-Failure Activities (Ash Recovery Project) Geosyntec took lead roles in the ash recovery project, including: (i) initial assessment of the extent of ash release; (ii) review of operations leading up to the release; (iii) design and construction monitoring for a permeable rock dike to mitigate further release of ash from the former dredge cell area; (iv) preparation of the Ballfield Area for use as a temporary staging area for dredged ash over a former ash pond area; (v) immediate removal of ash from a public highway and repair of a railroad line serving the facility (including stability evaluation of temporary slopes, and safety assessments of intact areas of the dredge cells); and (vi) assisting TVA with the development of a long-term strategy for CCR management.
Short-Term Ash Management: Following the ash release at TVA Kingston, Geosyntec developed a two- to five-year disposal plan that utilizes the Ballfield Area as an interim disposal/storage area to ensure continued operation of the TVA Kingston plant and to meet the U.S. Environmental Protection Agency requirements. Previous ground improvement measures designed by Geosyntec were used to assure regulators of the suitability of this area for short-term use.
Long-Term CCR Management: Geosyntec also assisted TVA in the development of long-term strategies for the management and disposal of CCR. Geosyntec participated in planning activities to assess the feasibility of off-site versus on-site disposal of CCR. In addition, we assisted in evaluating the feasibility of converting the facility from wet to dry disposal of CCR. TVA elected to re-permit the facility for dry disposal of CCR. This was a difficult task, since it was necessary to keep power generation activities operational while design modifications were completed, and a revised state permit was obtained.
To fulfill TVA's objectives, Geosyntec developed a corrective action plan that involved designing, re-permitting, and constructing the disposal facility in phases to address underlying karst and anticipated requirements of U.S. EPA's proposed CCR regulations. This resulted in returning the disposal facility to operation successfully while obtaining the regulator approvals from the Tennessee Department of Environment and Conservation in an expedited manner. Geosyntec also supported TVA with regulatory negotiations and public meetings.
This project received the American Council of Engineering Companies (ACEC) – Georgia 2014 Engineering Excellence Grand Award on the basis of future value to the engineering profession; social, economic and sustainable development considerations; complexity; and successful fulfillment of client/owner's needs.