United States
Environmental Protection
Agency
National Risk Management
Research Laboratory
Cincinnati, OH 45268
Research and Development
EPA/600/SR-93/182 September 1995
4>EPA Summary
Quality Assurance and Quality
Control for Waste Containment
Facilities
David E. Daniel and Robert M. Koerner
It is generally agreed that both qual-
ity assurance (QA) and quality control
(QC) are essential to the proper instal-
lation and eventual performance of en-
vironmentally safe and secure waste
containment systems. Even further,
there are both manufacturing and con-
struction aspects to many of the natu-
ral and synthetic materials that are
involved. At issue, however, is the ap-
propriate level of QA and QC, the
specific measures to be taken, the par-
ticular test methods to be used, the
frequency of these test methods and
the interrelationships of the various
personnel that may be involved. This
technical guidance document (TGD), or
"manual", has been prepared in an ef-
fort to address these issues.
The manual is not design oriented. It
presumes that a separate set of plans
and specifications has been, or will be,
prepared for the specific site in ques-
tion. Instead, the manual is focused on
the preparation and necessary ingredi-
ents of a QA plan (synonymously called
a QA document). This EPA technical
guidance document presents informa-
tion that can be used to craft a site-
specific plan for QA (and QC) purposes.
The opening chapter is focused on
the organizational concepts of a typi-
cal project and presents an overview
of QA/QC activities. It is an updated
and greatly expanded version of an ear-
lier EPA technical guidance document
on the same topic, i.e., EPA/530-SW-
86-031. Following the opening chapter
they are separate chapters on the spe-
cific components of waste containment
systems. In the order of their presenta-
tion they are as follows:
• compacted soil liners
• geomembranes
• geosynthetic clay liners
• soil drainage systems
• geosynthetic drainage systems
• vertical cutoff walls
• ancillary materials, appurtenances
and other details
This Summary was developed by
EPA's National Risk Management Re-
search Laboratory, Cincinnati, OH, to
communicate the salient points of the
state of the practice for construction
quality at waste containment facilities
that are fully documented in a separate
report of the same title (see Report
ordering information at back).
Chapter 1 - Concepts and
Overview
Upon defining the interrelated terms of
manufacturing quality control (MQC),
manufacturing quality assurance (MQA),
construction quality control (CQC) and con-
struction quality assurance (CQA), a flow
chart describing the organizational struc-
ture of a typical project is presented, see
Figure 1. Within this flow chart and its
description are a number of contentious
issues. For example, the corporate asso-
ciation between owner/operator, design
engineer and QA organization must be
kept separate so that a constant set of
checks and balances can result. If such
separateness is challenged the interrela-
tions between organizations can be re-
quested by the permitting agency. Also,
the geosynthetics manufacturer/fabricator
must have at least 10,000,000 ft2 (250
acres) of experience. This may be difficult
for new suppliers/installers, but the re-
quirement is considered to be necessary.
Lastly, both CQC and CQA organizations
must have a minimum number and expe-
rience level of "certified" personnel on
projects by Jan 1, 1996. The following
Printed on Recycled Paper
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Project Manager
or
General Contractor
Final
Approved Facility
Figure 1. Organizational structure of QA/QC inspection activities.
schedules are recommended (Tables 1
and 2). A certification program is ongoing
and is available through the National Insti-
tute for Certification in Engineering Tech-
nologies (NICET), at 1420 King Street,
Alexandria, VA 22314.
Interspersed throughout the opening
chapter is the critical nature of the QA plan.
The chapter clarifies and elaborates upon
all issues and details that are not included
in the project-specific plans and specifica-
tions. As with the project plans and speci-
fications, the QA plan is always site
specific. The QA plan must be submitted
to, and approved by, the regulatory agency
before a construction permit is issued. The
QAplan should also be available for all
construction organizations (i.e., general
contractor, earthwork contractor, geosyn-
thetic manufacturer and geosynthetic in-
staller) to review before the project is bid.
This is necessary so that the level of pro-
posed QA effort is clearly known and an-
ticipated by all parties involved with
manufacturing, construction and installa-
tion of the various materials.
Chapter 2 - Compacted Soil
Liners
Compacted soil liners consist of natural
clay materials or amended soil liners (usu-
ally with bentonite) to achieve the regula-
tory required value of the hydraulic
conductivity. Generally the value must be
equivalent to, or lower than, 1 X 1 Q~7 cm/
sec. The chapter provides detailed infor-
mation concerning critical variables, field
measurements, inspection of borrow ser-
vices and their excavation, preprocessing
of materials, placement of loose lifts, re-
molding and compaction, protection of the
compacted soil, test pads and final ap-
proval. The critical relationship between
clay soil moisture content and density are
explained thoroughly as illustrated in Fig-
ures 2 and 3. Soils must be compacted at
the proper water content to achieve the
desired low hydraulic conductivity. For the
soil illustrated in Figures 2 and 3, the
optimum water content is 17%. The soil
shown in Figure 2 was compacted with
standard Proctor energy at a water con-
tent of 16%, which left large voids be-
tween clods of clay and which produced
an unsatisfactorily large hydraulic conduc-
tivity. When the soil was wetted up to a
water content of 20%, the chunks of clay
were softened sufficiently to enable good
remolding during compaction; hydraulic
conductivity was adequately low. Specific
guidance on test methods, procedures,
sampling frequency, accept/reject consid-
erations and field experiences are de-
scribed throughout the chapter.
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Construction guidelines are included when-
ever appropriate since much of the rou-
tine testing in installation of compacted
soil liners is provided by the CQA person-
nel who must interact with the CQC per-
sonnel on a continuous basis.
Chapter 3 - Geomembranes
Geomembranes, also called flexible
membrane liners (FMLs) in many state
regulations, are factory manufactured syn-
thetic liner materials made from various
polymers. As such, there are both manu-
facturing and construction aspects to be
considered. This chapter addresses the
types and manufacturing of the most com-
monly used geomembranes. They are
listed in Table 3 along with their appropri-
ate formulations. Elements of manufactur-
ing are described so as to develop
adequate MQC/MQA protocol for
geomembranes made from extrusion pro-
cesses as well as calendered types.
The chapter also focuses on the con-
struction aspects of geomembranes, i.e.,
CQA and CQC, insofar as proper seam-
ing and joining is concerned. Emphasis is
placed on the various field seaming meth-
ods as noted in Table 4. All types are
described in a complete manner.
A complete description of seam tests
(shear and peel) is presented with appro-
priate guidelines on sampling strategies
and generally accepted minimum values.
The various nondestructive test (NOT)
methods given in Table 5 are addressed
with detailed descriptions of each method.
Handling, storage, backfilling and cov-
ering of geomembranes are also ad-
dressed. Included in the chapter are the
commonly referenced test methods, in-
sight into the recommended test frequen-
cies and the necessary information with
which to formulate a QA plan.
Chapter 4 - Geosynthetic Clay
Liners
The newest of liner, or barrier, materi-
als are called geosynthetic clay liners
(GCL's). These materials are composed
of geosynthetics (either geotextiles or
geomembranes) with an encapsulated or
associated layer of bentonite. While the
layer of bentonite is much thinner than a
compacted soil liner, the hydraulic con-
ductivity of bentonite is the lowest of any
naturally occurring soil material, e.g., it
typically varies from 1 X 1Q-9 to 5 X 1Q-9
cm/sec. Cross sections of the various com-
mercially available types of GCL's are il-
lustrated in Figure 4.
The chapter describes the type and
composition of GCLs followed by salient
features of the manufacturing process.
Bentonite tests and their recommended
frequencies are suggested. Sufficient de-
tail as to the associated geotextiles or
geomembranes are presented. This is fol-
lowed by sections on handling, installa-
tion, and backfilling/covering. Included are
recommended test methods for manufac-
turing and construction and the recom-
mended frequency of testing for the
formation of an appropriate QA plan.
Chapter 5 - Soil Drainage
Layers
Both sands and gravels are utilized in
waste containment facilities for leachate
collection layers beneath the waste, leak
detection layers between two liners be-
neath the waste, and for surface water
drainage layers above the waste in the
final cover. Thus it is necessary to include
them as an essential part of a waste con-
tainment liner system.
The chapter presents an introduction,
the relevant soil types, control of materi-
als, location of borrow sources, process-
ing of materials, placement, compaction
and protection of granular drainage soils
and filters. Both sands and gravels are
considered. Test methods and frequen-
cies are presented, e.g., see Table 6.
Concerns are also addressed. The use of
limestone sources is critiqued and some
identification materials and controls are
offered.
Chapter 6 - Geosynthetic
Drainage Systems
So as to counterpoint the natural soil
drainage and filter layers just described,
this chapter presents geosynthetic drain-
age and filter materials. The decision to
use natural soil materials or geosynthetics
is a design decision and is not addressed
in this manual.
Geonets are generally made from high
density polyethylene (HOPE) and the typi-
cal formulation along with the variations in
manufacturing are presented. Handling,
storage, acceptance/conformance testing,
placement, joining, and backfilling are ad-
dressed in a sequential manner.
Other types of drainage cores made
from columns, prisms, cuspations (single
or double), meshes and mats are also
described. As with other chapters, the req-
uisite test methods, their suggested fre-
quencies and construction details are
presented.
Insofar as geosynthetic drainage mate-
rials are concerned (i.e., they all provide
for in-plane flow of leachate or water)
geonets and geocomposite drainage cores
have open spaces to allow the liquid to
flow within them. Necessarily, they have a
geotextile covering attached to their ex-
posed surface(s). The geotextile acts as
both a filter and a separator. Geotextiles
are described in this chapter with respect
to their resin types, formulations and manu-
facturing. Protection (via wrapping), han-
dling, storage, placement, seaming and
backfilling/ covering are all described.
Seam types and tests, along with the rel-
evant geotextile tests are described.
Chapter 7 - Vertical Cutoff Walls
While most of the topics discussed in
this manual have the barrier material in a
horizontal or gently sloped orientation,
there is also a pressing need at some
sites for vertical barriers. Many sites (both
abandoned and newly constructed) require
vertical cutoffs which are either extended
into a low hydraulic conductivity layer be-
neath it (an aquiclude), or are deep enough
to thwart underlying seepage. These cut-
off walls are generally constructed using
the slurry wall method and are then back-
filled with a low permeability material, e.g.,
soil/bentonite. Figure 5 shows the con-
cept.
The chapter progresses through an in-
troduction, the concept of vertical cutoff
walls, construction issues, various types
of cutoff walls, specific CQA requirements
and post construction tests to assure con-
tinuity of the completed wall against seep-
age losses. The inclusion of a
geomembrane within the final backfill soil/
material is also described insofar as the
various types available and the methods
for joining the individual panels together.
Chapter 8 - Ancillary Materials,
Appurtenances and Other
Details
Clearly, waste containment systems are
a juxtaposition of an array of elements, all
of which are necessary to have an envi-
ronmentally safe and secure waste con-
tainment system. Thus, the concluding
chapter of the manual describes the "other''
details and materials necessary to achieve
the final goal of a complete waste con-
tainment system.
Included in the chapter are plastic pipe
(aka "geopipe") which is used for leachate
collection and removal systems, leak de-
tection systems and peripheral drainage
around the perimeter of the site for sur-
face water removal being shed from cover
systems. The pipes are made from either
HOPE or PVD and both smooth wall and
corrugated plastic pipe systems are in use.
The types of pipe, handling and conform-
ance testing are included in this subsec-
tion.
Sumps, manholes and risers to remove
leachste and to assess leak detection are
also included. Various strategies used by
designers are noted with appropriate com-
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mentary. Necessary In this regard are pen-
etrations of various barrier layers. Differ-
ent types of compacted clay liner,
geomembrane, and geosynthetic clay liner
penetrations are presented, although the
final decision and its appropriate design is
obviously at the discretion of the design
engineer.
Anchor trenches are illustrated with pros
and cons of the various configurations.
Access ramps are critically important
for below-grade waste containment facili-
ties. Numerous problems have arisen by
improper design and/or construction prac-
tices. Selected comments and precautions
are given.
Geosynthetic reinforcement materials
are seeing an increased use in waste
containment facilities. Veneer reinforce-
ment of leachate collection systems and
cover soils represents a major need for
the use of geogrids or high strength
geotextiles. The growing tendency of ver-
tical and lateral expansions of existing
landfill facilities for additional waste place-
ment also uses geogrids and high strength
geotextiles. Both of these applications are
illustrated in Figure 6 and are described in
this subsection.
The exposed surface of the landfills and
waste piles must necessarily be resistant
to water and wind erosion. Thus a sub-
section on the use of geosynthetic ero-
sion control systems is included.
Lastly, the use of geomembranes as
floating covers for surface impoundments
is included in the manual. Details of their
installation and inspection are included.
In conclusion, this technical guidance
document (or "manual") addresses QC and
QA for all facets of the individual compo-
nents of a waste containment system for
landfills, surface impoundments and waste
piles. Not only are the liner and cover
systems addressed, but vertical barriers
as well. Note that the QA plan is not
written In a "cook book" fashion since the
final QA plan is clearly site specific and
material specific. However, the essential
items for a successful QA plan are pre-
sented and with judicious use of the
manual, coupled with the experience of
the designer and CQA organization, a
proper QA plan can be written.
Accompanying this technical guidance
document are numerous references, most
of which are EPA manuals or ASTM test
methods. The EPA manuals are available
either from the Agency or NT1S. To assist
the reader in gathering the various test
methods, a companion document pub-
lished by the American Society of Testing
and Materials (ASTM) is available which
reprints all of the test methods referenced
in the manual. Included are 79 separate
ASTM test methods and 10 additional ref-
erenced test methods by other standard-
ization group.
Footnotes:
I.This EPA manual is available
from NTIS at a cost of $44.50
each. The NTIS Number is
PB94-159100.
2. The companion document of 89
test methods referenced in the
manual is available from ASTM
for $77.00. The ASTM member
price is $69.00. The ASTM Pub
lication Code Number (PCN) is
03-435193-38.
3. An expanded and somewhat
modified version of the manual is
available from ASCE Sales De
partment at the list price of $48.00
and the ASCE member price of
$36.00.
Table 1. Recommended Implementation Program for Construction Quality Control (CQC) of
Geosynthetics* (Beginning Jan 1, 1993)
No. of Field Crews"
At Each Site
End of 18 Mo
(i.e., June 30, 1994)
End of 36 Mo
(i.e, Jan 1, 1996)
1-4
>5
1 - Level II
1 - Level II
2 - Level I
1 - Level III"
1 - Level ///**'
1 - Level I
Table 2. Recommended Implementation Program for Construction Quality Control (CQA) of
Geosynthetics' (Beginning Jan 1, 1993)
No. of Field Crews"
At Each Site
1-2
3-4
End of 18 Mo
(i.e., June 30, 1994)
1 - Level II
1 - Level II
End of 36 Mo
(i.e, Jan 1, 1996)
1 - Level III*"
^ 1 ™,al III**"
>5
1 - Level I
1 - Level II
2 - Level I
1- Level I
1 - Level III"'
1 - Level II
1 - Level I
Certification for natural materials is under development as of this writing.
Performing a Critical Operation; Typically 4 to 6 People/Crew.
Or PE with applicable experience.
Table 3. Types of Commonly Used Geomembranes and Their Approximate Weight Percentage Formulations'
Geomembrane
Type
HOPE
VLDPE
Other Extruded Types
PVC
CSPE-R
Other Calendered Types
Resin
95-98
94-96
95-98
50-70
40-60
40-97
Plasticizer
0
0
0
25-35
0
0-30
Filter
0
0
0
0-10
40-50
0-50
Carbon Black
or Pigment
2-3
2-3
2-3
2-5
5-40
2-30
Additives
0.25-1.0
1-4
1-2
2-5
5-15
0-7
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16
STANDARD
PROCTOR
Figure 2. Photograph of highly plastic clay compacted with standard proctor effort at a water content of 16% (1% dry of optimum).
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STANDARD
PROCTOR
F/3l/rfl 3. Photograph of highly plastic clay compacted with standard proctor effort at
i water content of 20% (3% wet of optimum).
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Table 4. Possible Field Seaming Methods for Various Geomembranes Listed in this Manual
Type of Seaming
Method HOPE
extrusion
(fillet and flat) A
thermal fusion
(hot wedge and hot air) A
chemical
(chemical and bodied
chemical)n/a n/a
adhesive
(chemical and contact) n/a
Note: A = applicable; n/a = not applicable
Table 5. Applicability of Various Nondestructive
NOT Method
1. air lance
2. mechanical point stress
3. dual seam
4. vacuum chamber
5. electric wire
6. electric current
7. ultrasonic pulse echo
8. ultrasonic impedance
9. ultrasonic shadow
" E Fit. - extrusion fillet
E Fit. = extrusion flat
HW = hot wedge
HA = hot air
Type of Geomembrane
VLDPE Other PE PVC
A A n/a
A A A
n/a A A
n/a n/a A
Test Methods to Different Seam Types and Geomembrane Types
Seam Types*
C, BC, Chem A, Cont. A
all
HW, HA
all
all
all
HW,HA
C, BC,
Chem. A, Cont. A
HW,HA
C, BC,
Chem. A, Cont. A
E Fit., E Fit., HW, HA
C — chemical
BC = bodied chemical \
Chem. A = chemical adhesive
Cont. A = contact adhesive
CSPE-H Other Flexible
n/a A
A A
A
A A.
Geomembrane Types
all except HOPE
all
all
all
all
all
HOPE, VLDPE, PVC
HOPE, VLDPE, PVC
HOPE, VLDPE
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~5mm
Upper Geotextile
A x___ Lower Geotextile
(a) Adhesive Bound Clay to Upper and Lower Geotextiles
- 5mm
Upper Geotextile
Stitch Bonded
in Rows
Lower Geotextile
(b) Stitch Bonded Clay Between Upper and Lower Geotextiles
Upper Geotextile
• 4-6 mm y
Needle Punched
Fibers Throughout
Lower Geotextile
(c) Needle Punched Clay Through Upper and Lower Geotextiles
~4.5 mm
Lower or Upper
Geomembrane
Figure 4. Cross section sketches of currently available geosynthetic clay liners (GCLs).
8
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Table ft Recommended Tests and Testing Frequencies for Soil Drainage Materials
Location of Sample
Type of Test
Potential Borrow Source
Onsite; After Placement
and Compaction
Grain Size (ASTM D-422)
Hydraulic Conductivity (ASTMD-2434)
Carbonate Content' (ASTM D-4373)
Grain Size (ASTM D-422)
Hydraulic Conductivity (ASTM D-2434)
Minimum Frequency
2500yd3
2500yd3
2500yd3
1 per Hectare tor Drainage
Layers; 1 per 650 yd3 for Other Uses
1 per Hectare for Drainage
Layers; 1 per 650 yd3 for Other Uses
1 per 2500 yd3
— Moonne content' (ASTM D-4373) 1 per 2500 yd3
^notS^
Backfill
Mixing Area
Trench Spoils
ir
Area of Active.
Excavation
Figure 5. Diagram of construction process for soil-bentonite-backfilled slurry trench cutoff wall.
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Reinforcement
(Geogrid or Geotextile)
Cover Soil
(a) Cover Soil Veneer Stability
Geomembrane
r
Separate
Anchor
Trenches
Proposed
Waste
Leachate Collection Soil
Reinforcement
(Geogrid or Geotextile)
(b) Leachate Collection Soil Veneer Stability
Geomembrane
Reinforcement
(Geogrid or
Geotextile)
(c) Liner System Reinforcement for "Piggy backing"
Figure 6. Geogrid or geotextite reinforcement of (a) cover soi, above waste, (b) legate collection layer beneath waste, and (c) liner system place*
above existing waste ("Piggybacking").
10
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David E. Daniel is with the University of Texas at Austin, Department of Civil
Engineering, Austin, TX 78712.
Robert M. Koemerls with Drexel University's Geosynthetic Research Institute,
Philadelphia, PA 19104.
David Carson is the EPA Project Officer (see below).
The complete report, entitled "Quality Assurance and Quality Control for Waste
Containment Facilities," (EPA/600/R-93/182); (Order No. PB94-159
100AS; Cost: $44.50, subject to change) is available only from:
National Technical Information Service
5285 Port Royal Road
Springfield, VA 22161
Telephone: 703-487-4650
The EPA Project Off leer can be contacted at:
National Risk Management Research Laboratory
U.S. Environmental Protection Agency
Cincinnati, OH 45268
United States
Environmental Protection Agency
National Risk Management Research Laboratory (G-72)
Cincinnati, OH 45268
Official Business
Penalty for Private Use
$300
BULK RATE
POSTAGE & FEES PAID
EPA
PERMIT No. G-35
EPA/600/SR-93/182
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