Geosynthetics August/September 2020 - 22

CCR landfill final cover test pad-Part 1

Test pad description

upper bench, and separated by a 3H:1V
slope, was constructed at the landfill
site to establish appropriate specifications for the landfill final cover design
and construction.
The purpose of this article is to
describe the materials, procedures and
equipment used to construct the landfill
final cover system test pad and the evaluation of the completed test pad.

FIGURE 2 Final cover system
cross section. Note drainage
space between geotextile and
IDS geomembrane. (Not to scale,
figure courtesy of AGRU)

The test pad layers followed the requirements of the WVDEP permit and U.S.
Environmental Protection Agency (EPA)
rule for a landfill final cover, and included
the following (from the bottom up):
*	 Earthen subgrade
*	 50-mil (1.27-mm) high-density
polyethylene (HDPE) integrated
drainage system geomembrane
*	 Minimum 8-ounce/square-yard
(271-g/m2) nonwoven IDS geotextile
*	 A 6-inch (15.2-cm) diameter perforated bench collection pipe
*	 Minimum 18-inch (45.7-cm) thickness of final cover soil over the IDS
geomembrane and geotextile
The IDS geomembrane is manufactured to provide a studded drainage surface on the top side and a spiked friction
surface on the bottom side. When covered

FIGURE 3 Test pad cross section, subareas C, E and A

Upper Bench

Top of Final Cover
Soil

18 in (46 cm) Lift Unprocessed Soil
(see Note 1)
8 oz/yd2 (271 g/m2) Nonwoven Geotextile
Subarea C

6 in (15 cm) Lift
Processed Soil
(See Note 2)

SUBAREA C

SUBAREA E E
Subarea

Top of CCR

6.1(6.1
m (20m)
ft)
20 ft

CCR

IDS Geomembrane

See Detail A
Min. 6 in (15 cm)Temporary Cover Soil
Prepared Subgrade

12 in (30.5 cm) Lift
Processed Soil
Cushion Geotextile
(Bench Only)

rea A

Suba

8 oz/yd2 (271 g/m2) Nonwoven Geotextile
(Installed in Contact with the IDS
Geomembrane)
IDS Geomembrane (Installed in Contact with
the Subgrade)

See Detail B

(20 m)
ft)
206.1
ft m
(6.1
CCR

Legend

Prepared Subgrade

Prepared Subgrade

Temporary Soil Cover

Added Protrusion (No. 57 Aggregate)
Added Protrusion

Top of
CCR

IDS Geomembrane
Nonwoven Geotextile
Hard Angular Rock, Approximate Maximum Dimension 4 in (10 cm)
Cushion Geotextile

Notes:

IDS Geomembrane (Installed in Contact
with the Cushion Geotextile)

1. Unprocessed soil had rocks and woody material
greater than 9 in (23 cm) in any dimension removed
prior to placement.

Cushion Geotextile (on Bench Only)
Prepared Subgrade

2. Processed soil is soil from the stockpile which had
application of the root rake to remove rocks and
woody material larger than 4 in (10 cm).

GAI FILE NUMBER:

22

Geosynthetics
| August September 2020
C130109-05-A2-002

8 oz/yd2 (271 g/m2) Nonwoven Geotextile
(Installed in Contact with the IDS
Geomembrane)

Top of CCR

FIGURE: 2

GAI DRAWING NUMBER:

002

DRAWN BY:

CLIENT

MAYHOEJ

TEST PAD CROSS SECTION

APPALACHIAN POWER CO.

SHEET NO.:

SCALE:

SUBAREAS C, E, AND A

JOHN E. AMOS LANDFILL

OF

N.T.S

PROJECT
Figure 2. Test
Pad Cross Section Subareas C, E, and A

0820GS_p20-27.indd 22

CHECKED BY: APPROVED BY:
ISSUE DATE:

© 2019 GAI Consultants 7/22/20

9:30 PM
Geosynthetics August/September 2020

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