Hydraulic Conductivity of Compacted Soil Liners Permeated with Coal Combustion Product Leachates

Craig H Benson,Jiannan N Chen,William J Likos,Tuncer B Edil

doi:10.1061/(asce)gt.1943-5606.0001855

Abstract

AbstractTests were conducted on eight soils to determine how coal combustion product (CCP) leachates may affect the hydraulic conductivity of compacted soil liners (CSLs) used for CCP disposal faci...

Highlights

Federal regulations in the United States require that waste containment facilities for disposal of coal combustion products (CCPs) use a composite liner consisting of a geomembrane at least 0.75 mm thick placed directly on top of a soil liner at least 0.6 m thick
Tests were only conducted on SC10 with DI water and with trona leachate because the high hydraulic conductivity (>1 × 10−7 m=s) to DI water was unrealistic for a compacted soil liner (CSL)
Tests were conducted on eight finer-grained soils to evaluate how coal combustion product leachates may affect the hydraulic conductivity of compacted soil liners used for CCP disposal facilities

Summary

Introduction

Federal regulations in the United States require that waste containment facilities for disposal of coal combustion products (CCPs) use a composite liner consisting of a geomembrane at least 0.75 mm thick placed directly on top of a soil liner at least 0.6 m thick. Previous studies have evaluated how the hydraulic conductivity of CSL soils is affected by permeation with organic liquids and leachates containing organic compounds (e.g., Brown and Anderson 1983; Fernandez and Quigley 1985, 1988; Evans and Fang 1986; Bowders and Daniel 1987; Broderick and Daniel 1990; Shackelford 1994), municipal solid waste leachates (Yanful et al 1990), and inorganic industrial solutions such as wastewater effluent and mine tailings drainage (Edil et al 1987; Yanful et al 1995; Alston et al 1997). Permeation with inorganic solutions that are very dilute, have lower cation valence than the original pore water, or contain suspended solids can result in lower hydraulic conductivity due to an increase in thickness of the bound water layer or deposition of solids (Yanful et al 1990; Bradshaw and Benson 2013; Setz et al 2017)

Methods

Results

Conclusion