Liner Systems for Aggressive Coal Combustion Product Leachates

Investigator: George Mason University

Start Date:
October 2017

Award Amount:
$150,000

New regulations established for disposal of coal combustion products (CCPs) require that disposal facilities include a composite liner consisting of a geomembrane overlying a 0.6-m-thick clay liner. An economical alternative is to use of a geosynthetic clay liner (GCL) in lieu of the clay liner. Implementation of the new regulations has revealed a large number of waste streams from coal-fired power plants that generate leachates much more concentrated than those from historical coal-combustion wastes (5 M vs. 0.7 M). Preliminary tests show the currently available GCLs cannot retain these concentrated leachates. Finding GCL materials that can withstand these aggressive leachates is critical to prevent leachate from entering the groundwater. The overall objectives of the proposed study are:

  1. Develop and evaluate new bentonite-polymer (B-P) composite GCL materials to manage aggressive leachates.
  2. Understand key parameters that affect the hydraulic conductivity of B-P GCLs.