Geosynthetics August/September 2020 - 21

CCR landfill final
cover test pad-Part 1
By Nina J. Balsamo, John Massey-Norton, John R. Klamut, Terry Queen,
Charles F. Straley and Mark R. Lehner

n integrated drainage system (IDS) geomembrane, which provides both
a low-permeability membrane and drainage space above the geomembrane, is being used in the final cover at a coal combustion residuals (CCR)
landfill in West Virginia. Part 1 of this article presents construction in 2016
of the test pad (Figure 1) to evaluate 1-inch (2.5-cm) maximum subgrade
protrusions beneath the geomembrane, placement of cover soil with a 9-inch
(22.9-cm) maximum particle size using a low ground pressure (LGP) dozer,
and the condition of the geosynthetics. Part 2 of this article will present the
application of heavy traffic loads over the benched portion of the test pad to
evaluate its use as a temporary haul road (in 2016), and additional exhumation of the test pad in 2018.

PROJECT HIGHLIGHTS
COAL COMBUSTION
RESIDUALS TEST PAD
DESIGN ENGINEER

GAI Consultants Inc.
GEOSYNTHETICS PRODUCTS

Agru Super Gripnet® 50 mil
HDPE liner and AgruTex 081
nonwoven geotextile
GEOSYNTHETICS MANUFACTURER

Agru America Inc.

Background and purpose
GAI Consultants Inc. (GAI) is the engineer of record for an active landfill
located in West Virginia and owned by a North American electric utility company. The landfill is permitted for disposal of fly ash, bottom ash
and synthetic gypsum by the West Virginia Department of Environmental
Protection (WVDEP). The approximate surface area of the completed landfill
will be 192 acres (77.7 ha).
A final cover system design was submitted to the WVDEP to meet the
requirements of 40 Code of Federal Regulations Part 257.102, "Criteria for
conducting the closure or retrofit of coal combustion residual (CCR) units"
(CFR 2015).
The Geosynthetic Institute's GRI Guide GS11, "Standard Guide for
Constructing Test Pads to Assess Protection Materials Intended to Avoid
Geomembrane Puncture" (GRI 2012) provides guidance on methodology and construction of field test pads to assess puncture performance
of geomembranes. Based on the GRI Guide (modified), a 46-foot (14.0m) wide by 103-foot (31.4-m) long test pad, consisting of a lower and

Nina J. Balsamo, P.E., is a senior project
engineer at GAI Consultants Inc. based
in Pittsburgh, Pa.
John T. Massey-Norton is a retired
hydrogeologist at a major electric
utility company.
John R. Klamut, P.E., is a senior project
manager with GAI based in Pittsburgh, Pa.
Terry Queen is senior lead construction
technician with GAI based in Charleston, W.V.
Charles F. Straley, P.E., P.S., is a senior
engineering manager at GAI based in
Charleston, W.V.
Mark R. Lehner, P.E., is a senior engineering
manager at GAI based in Pittsburgh, Pa.
All figures courtesy of the authors

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Geosynthetics August/September 2020

Table of Contents for the Digital Edition of Geosynthetics August/September 2020