Lessons Learned Through the Implementation of In-Situ Stabilization for the Closure of a Coal Combustion Residue Site.pdf

Vincent Spillane, Geo-Solutions, Inc.
Michael Fisher, Geo-Solutions, Inc.
Darin Payne, Geo-Solutions, Inc.

Description

Lessons Learned Through the Implementation of In-Situ Stabilization for the Closure of a Coal Combustion Residue Site Authors Mr. Vincent Spillane - United States - Geo-Solutions, Inc. Mr. Michael Fisher - United States - Geo-Solutions, Inc. Mr. Darin Payne - United States - Geo-Solutions, Inc. Abstract The traditional means of dealing with coal combustion residual (CCR) materials include excavation and off-site disposal. This approach can be impacted by site-specific geotechnical and hydrological features which dramatically increase cost and complexity. In many cases, it makes sense to consider a way to keep the material on site, for example using in-situ stabilization/solidification (ISS). ISS is a technically sound and economical solution for remediating CCR and other wastes and was recently used as part of the in-place closure of a 2.25-acre ash pond. Transitioning from the bid stage to the in-field pilot program and then full scale, the Contractor evaluated multiple means of ash stabilization through the use of vertical auger and hydraulic excavator mixing. In total, 48,000 cubic yards of CCR material was stabilized reaching depths of approximately 25 feet below a prepared working platform. A site-specific mixture of blast-furnace slag and Portland cement grout was used to improve the physical properties of the material contained within the pond footprint and to reduce its impact on the surrounding soil and water. This paper describes various lessons learned through the development and completion of the project including pre-construction considerations and full-scale implementation of ISS in an ash pond environment. The authors further outline general constructability concerns for future use of ISS in similar applications. Overall, this case study paper shows that all performance requirements were achieved with the project being completed safely, on budget, and within the estimated schedule.

 
May 15th, 8:00 AM May 15th, 8:30 AM

Lessons Learned Through the Implementation of In-Situ Stabilization for the Closure of a Coal Combustion Residue Site.pdf

Grand Rapids, Michigan

Lessons Learned Through the Implementation of In-Situ Stabilization for the Closure of a Coal Combustion Residue Site Authors Mr. Vincent Spillane - United States - Geo-Solutions, Inc. Mr. Michael Fisher - United States - Geo-Solutions, Inc. Mr. Darin Payne - United States - Geo-Solutions, Inc. Abstract The traditional means of dealing with coal combustion residual (CCR) materials include excavation and off-site disposal. This approach can be impacted by site-specific geotechnical and hydrological features which dramatically increase cost and complexity. In many cases, it makes sense to consider a way to keep the material on site, for example using in-situ stabilization/solidification (ISS). ISS is a technically sound and economical solution for remediating CCR and other wastes and was recently used as part of the in-place closure of a 2.25-acre ash pond. Transitioning from the bid stage to the in-field pilot program and then full scale, the Contractor evaluated multiple means of ash stabilization through the use of vertical auger and hydraulic excavator mixing. In total, 48,000 cubic yards of CCR material was stabilized reaching depths of approximately 25 feet below a prepared working platform. A site-specific mixture of blast-furnace slag and Portland cement grout was used to improve the physical properties of the material contained within the pond footprint and to reduce its impact on the surrounding soil and water. This paper describes various lessons learned through the development and completion of the project including pre-construction considerations and full-scale implementation of ISS in an ash pond environment. The authors further outline general constructability concerns for future use of ISS in similar applications. Overall, this case study paper shows that all performance requirements were achieved with the project being completed safely, on budget, and within the estimated schedule.