Preparing to Dewater a CCR Pond

Ron Hager, Burns & McDonnell
James Feild, Burns & McDonnell

Description

PREPARING TO DEWATER A CCR POND: WAYS TO BETTER UNDERSTAND YOUR POND CHARACTERISTICS AND PLAN FOR A SUCCESSFUL DEWATERING EFFORT Authors Mr. Ron Hager - United States - Burns & McDonnell Dr. James Feild - United States - Burns & McDonnell Abstract Prior to dewatering a CCR pond, Owners and Operators should make the financially responsible decision to invest in the data gathering process to better understand the conditions of the surface impoundment, the properties of the CCR materials contained in the impoundment, and the potential approaches to remove the separable pore water from the ash materials prior to closure. This proactive approach includes a review of historical data, a field investigation, and a pilot study prior to moving to a full-scale dewatering approach. Prior to conducting a field investigation on the emplaced ash materials, the results of previous investigations were gathered to create a repository of data and analyzed to construct an initial conceptual site model. A field investigation was implemented that included piezometers, cone penetrometer tests, hydraulic profiling tool, and in-situ vane shear testing to create a more robust set of data regarding the response of ponded CCR during dewatering. This data was used to measure hydraulic conductivity, collect soil samples for grain size analysis, and verify the lithology. In-situ vane shear testing was also performed to measure the material's shear strength to better understand the risk for instability during unwatering. This field investigation provided the key data to identify the proposed dewatering methods to be implemented in the pilot study. A dewatering pilot study has been proposed for implementation at the site in the summer of 2024. The objectives of the pilot study will be to implement multiple dewatering techniques that were identified as being compatible with site conditions based on data gathered during the field investigation. The key to a successful dewatering program is to do the necessary upfront research to understand the characteristics of your pond, the CCR materials, and what techniques will help to dewater your pond in the most effective and cost-efficient manner.

 
May 14th, 2:30 PM May 14th, 3:00 PM

Preparing to Dewater a CCR Pond

Grand Rapids, Michigan

PREPARING TO DEWATER A CCR POND: WAYS TO BETTER UNDERSTAND YOUR POND CHARACTERISTICS AND PLAN FOR A SUCCESSFUL DEWATERING EFFORT Authors Mr. Ron Hager - United States - Burns & McDonnell Dr. James Feild - United States - Burns & McDonnell Abstract Prior to dewatering a CCR pond, Owners and Operators should make the financially responsible decision to invest in the data gathering process to better understand the conditions of the surface impoundment, the properties of the CCR materials contained in the impoundment, and the potential approaches to remove the separable pore water from the ash materials prior to closure. This proactive approach includes a review of historical data, a field investigation, and a pilot study prior to moving to a full-scale dewatering approach. Prior to conducting a field investigation on the emplaced ash materials, the results of previous investigations were gathered to create a repository of data and analyzed to construct an initial conceptual site model. A field investigation was implemented that included piezometers, cone penetrometer tests, hydraulic profiling tool, and in-situ vane shear testing to create a more robust set of data regarding the response of ponded CCR during dewatering. This data was used to measure hydraulic conductivity, collect soil samples for grain size analysis, and verify the lithology. In-situ vane shear testing was also performed to measure the material's shear strength to better understand the risk for instability during unwatering. This field investigation provided the key data to identify the proposed dewatering methods to be implemented in the pilot study. A dewatering pilot study has been proposed for implementation at the site in the summer of 2024. The objectives of the pilot study will be to implement multiple dewatering techniques that were identified as being compatible with site conditions based on data gathered during the field investigation. The key to a successful dewatering program is to do the necessary upfront research to understand the characteristics of your pond, the CCR materials, and what techniques will help to dewater your pond in the most effective and cost-efficient manner.