530-SW-85-013
DRAFT
Mininum Technology Guidance
on
Single Liner Systems
for
Landfills, Surface Inpoundrents, and Waste Piles—
Design, Construction, and Operation
U.S. Environmental Protection Agency
Region 5, Library (PL-12J)
77 w«st Jackson Boulevard. 12th Floor
Chicago.it 60604-3590
Second version
May 24,1985
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OSWER POUCT DIRECTIVE NO.
A-
— o
OSWER POLICY DIRECTIVE NO.
9480-00-1
MEMORANDUM
SUBJECT* Draft Guidance on Implementation of the Minimum
Technological Requirements of the Hazardous and
Solid Waste Amendments of 1984
FROMt John H. Skinner, Director
Office of Solid Waste (WH-562)
TOt Division Directors, Regions 1-10
Attached is the second draft of our guidance for implementing
the minimum technological requirements of Sections 3004(o) and
3015 of the Resource Conservation and Recovery Act, as amended
by the Hazardous and Solid Waste Amendments (USWA) of 1984.
As you know, Sections 3004(o) and 3015 require, for hazardous
waste landfills and surface inpoundwents, installation of two
or more liners and a leachate collection system above (in the
case of landfills) and between such liners. As of November 8,
1964, permits cannot be issued to landfills and surface impoundments
unless they address these requirements. Certain interim status
landfills and surface impoundments had to meet these requirements
by May 8, 1985. In addition, Section 3015 requires certain
interim status waste piles to meet our existing single liner
and. leachate collection system requirements that had previously
been in effect for only new permitted waste piles.
•A:.~--:"S^MFh«) second draft of our guidance for implementing the
minimum technological requirements is a result of our review
and incorporation of eone 100 sets of comments that we received
on the first draft,of the^guidance from the Regional Offices,
States, facility owners an* operators, environmental groups,
liner irjinufacturers and installers, and others. The first
draft was cade available for comment in two portions, on
December 20, 19£4, and on February 1, 1985.
Following is a brief list of major comments received on the
firat draft of the guidance and a statement of how the comments
were uaed in developing the second draft.
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OSWER POLICY DIRECTIVE i\G.
-•U
1 tt ,V Q
OSV • POEICY i
2
94.S •:) « 00- 1 00
* Many comments asked for clarification as to the
applicability of the minimum technological requirements
to various unit-apeci.fic situations. we have riaae rr;ore
clear the discussion of applicability iu the guidance
and have included a series of questions anu answers
addressing the key cor.icients raised.
* Comnienters asked that the recommendation that the unit
be above the seasonal high water table be deleted. This
guidance was not changed because installation of the
double liner systems described in the guidance below the
water table could change the function/objective of these
designs. however, double liner systems in saturated soils
may be acceptable depending on site-specific consideratons.
* Sore conur.enters stated that the primary leachate collection
system should cover the siciewalls as well as the base of the
unit. This comment was adopted in the guidance.
* Gome cotomeriters recommended deletion of the synthetic/
conpacted soil double liner system from the guidance
because this design would require a contacted soil layer
of impractical thickness, and because it is not aa
protective as the synthetic/composite double liner design.
We retained the synthetic/compacted soil design in the
guidance because it is similar to the interim statutory
design of Section 3004(o)(5)(B).
Comrrtenters recorwnended that the compacted soil component
in the composite bottom liner should be chemically
rtsistant to the waste and leachate in the unit. We
adopted this recoiwuendation.
* Several commenters asked that the minimum six inches of
bedding naterial recommended in the guidance as a protective
layer for synthetic liners be increased to twelve inches.
We adopted this recommendation.
This second draft of our guidance updates the December 20,
1984, and February 1, 1S85, versions. The attached guidance is
in the form of a draft Reauthorization Statutory Interpretation
document, which discusses policy and interpretational issueo, and
two attachments that contain detailed technical guidance for the
design, construction, and operation of both single and double
liner and leachate collection systems. Attached is the following
guidance:
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POLICY DIRECTIVE HO.
NO.
9*80-00-1 Qs
Draft Guidance on Implementation of the Minijauzu Technological
Requirements of HSWA of 1984, Respecting Liners and
Leachate Collection Systems; Pe authorization Statutory
Interpretation *5D; EPA/530-SW-4J5-012; (earlier draft
issued February 1, 1985)
Draft Minimum Technology Guidance on Double Liner Systems
for Landfills and Surface Impoundments — Design, Construction,
and Operation; EPA/530-SW-85-014; (earlier draft issued
December 20, 1934)
Draft Minimum Technology Guidance on Single Liner Systems
for Landfills, Surface Impoundments, and Waste Piles —
Design, Construction, and Operation; EPA/530-SW-65-013;
(earlier draft guidance issued July 1982)
We will shortly be proceeding with final clearance of the
guidance. If you have any comments or questions on this draft,
please contacts Robert Tonetti, Land Disposal Branch, Waste
Management and Economics Division, Office of Solid Waste (WH-565E),
Washington, D.C. 20460, phone (202) . 382-4654.
Within the next two or three months, we expect to propose
a rule (the "proposed codification rule") that will meet the
requirements of Section 3004 (o) (5) (A) and include one or more
double liner and leachate collection system designs. When
promulgated in final form, this rule will supersede the interim
statutory double liner standard of Section 3004 (o) (5) (B) . Our
current plans are for final promulgation of the rule in the
spring of 19 8G. At that tiiae, it will likely be necessary to
update the attached guidance further.
Attachments
WH-565EsBob Tonetti*pm:S206: 382-4654: WSMi 5/23/85
i
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Minimum Technology Guidance on
Single Liner Systems for
Landfills, Surface Inpoundments, and
Waste Piles
TABLE OF CONTENTS
PAGE
INTRODUCTION 1
I. Leachate Collection and Removal Systems for 9
Landfills and Waste Piles
A. Guidance 9
B. Discussion.... 11
II. Liner Specifications 16
A. Guidance 33
B. Discussion 47
III. Construction Quality Assurance 47
A. Guidance 47
B. Discussion 49
References 54
Suggested Reading List 57
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Introduction
On November 8, 1984, the President signed into law the Hazardous and Sol.
Waste Amendments of 1984 (HSWA). Section 3015(a) of HSWA contains rainiirum
technology requirements for interim status waste piles. Such waste piles are
initially required by ^3015 to meet the existing EPA requirements under $264. '<
i.e., certain interim status waste piles must have single liner systems. The
new requirements for interim status waste piles apply to new units and replace
and lateral expansions of existing units. In addition, the existing single
liner standards of $264.221(a), for surface impoundments, and §264.301(a), for
landfills, still have applicability to portions of existing units that are not
covered by waste at the time of permit issuance. The single liner design
requirements of Part 264 are expressed in terms of the performance to be achie
by the unit design rather than specific design standards, such as type and
thickness of liner naterial. This guidance docutmit is intended to provide
-guidance for owners/opera tors and EPA and State regulatory personnel on design:
that the Agency believes meet the requirements of $$264.221(a), 264.251(a),
and 264.301(a). This document identifies design, construction, and operation
specifications that can be used by owners and operators in order to comply
with the requirements of $§264.221(a), 264.251(a), and 264.301(a).
The designs included in this guidance are by no means intended to cover th
entire spectrum of acceptable liner systems. CVners or operators wishing to
use a different design, but one that contains the basic design components of
$§264.221(a), 264.251(a), or 264.301(a), i.e., liners and/or leachate collectic
systems, may be able to demonstrate compliance with the performance requirement
for the specific facility components. An easy way to demonstrate compliance
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with the performance requirements would be to show that the specific ^esi^n
for a particular unit provides the same level of performance as would the
design contained in this guidance if it were installed under similar circumstances
(such as waste characteristics, location, rainfall, etc.). The Agency will
accept convincing performance equivalency demonstrations to the specifications
in this guidance as adequate demonstration of compliance with the appropriate
performance statenents of §S264.221(a), 264.251(a), or 264.301(a).
The designs included in this guidance are intended only for use in the
unsaturated zone (i.e., above the high water table). This does not mean that
the Agency has ruled out the location of facilities in the saturated zone.
However, permit applicants seeking to locate in the saturated zone cannot
necessarily rely on the designs specified in this guidance but rather must
demonstrate that their intended design meets the applicable standards of
S§264.221(a), 264.251(a), or 264.301(a) in their specific location.
The Part 264 single liner regulations require that landfills, surface
impoundments, and waste piles have liners designed to prevent migration to the
adjacent subsurface soil or ground water or surface water during their active
lives. In the case of a storage or treatment unit (i.e., a waste pile or a
surface impoundment from which wastes and waste residues will be removed or
decontaminated at closure), the liner may be constructed of materials that may
allow wastes to migrate into the liner (but not into the adjacent subsurface
soil or ground water or surface water) during the active life of the unit,
provided that the liner is removed at closure. (The active life of the unit
includes all closure activities, but does not include the post-closure care
period.) '"hug, -in ^pproprMtf si niHti'-.m.b, "lay nr artmittcd materials may be
acceptable liner materials (Figures 1 and 2). In the cases of landfills
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and surface inpoundnents used to dispose of hazardous waste, the regulations
provide that the liner must be constructed of materials that prevent wastes
from passing into the liner (Figures 3 and 4). Synthetic liners are the only "
conrncnly used raaterials of which EPA is aware that would meet this standard.
This guidance is intended to incorporate the current state-of-the-art
regarding the design, construction, and operation of hazardous waste land dispos
units. The attenpt has been made to include an element of practicality in
specifying how to construct a unit. However, this guidance does not address
all conrponents of facility design, construction, operation, and closure. For
exanple, it does not address the final cover requirements for landfills and
certain surface impoundments, nor does it discuss considerations for freeboard
in impoundment design and operation. The Agency's previously issued guidance
(July 1982) continues to be applicable in these areas.
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Leachate
Collection
and
Removal
System
FIGURE 1
SCHEMATIC OF A COMPACTED SOIL SINGLE LINER SYSTEM
FOR A WASTE PILE
Protective
Soil or Cover
(optional)
Thick Layer"
Compacted Low Permeability Soil
C
I
n>
Liner
(compacted soil)
Filter Medium
'Thickress to be determined by break-through time.
(Nut to Scale)
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FIGURE 2
SCHEMATIC OF A COMPACTED SOIL SINGLE LINER SYSTEM
FORA
TREATMENT. STORAGE, OR DISPOSAL SURFACE IMPOUNDMENT
IQ
Protective
Spil or Cover
(optional)
Thick Layer*
Compacted Low Permeability Soil
Native Soil Foundation
Liner
(compacted soil)
Thickne ,s to be determined by break through time.
(Not to Scjle)
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Leachate Co lection
and
Removal System
FIGURE 3
SCHEMATIC OF AN FML SINGLE LINER SYSTEM
FOR A LANDFILL
ua
c
OJ
Protective
Soil or Cover
(optional)
IIMIMIH '"
Native Soil Foundation
(Nut
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FIGURE 4
SCHEMATIC OF AN FML SINGLE LINER SYSTEM
FORA
TREATMENT. STORAGE. OR DISPOSAL SURFACE IMPOUNDMENT
to
c
CD
4*
Protective
Soil or Cover
(optional)
Native Soil Foundation
(Not to Scale t
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I. Leachate Collection and Removal Systems for Landfills and
'^'aste Piles
Contents
Page
A. Guidance 9
Objective 9
Design specifications 9
Construction specifications 11
Operation specifications 11
B. Discussion 11
A. Guidance
Overall Design, Construction/ and Operation Objective
The system should be designed to ensure that the leachate depth above
the liner does not exceed one foot; be constructed of materials that can
withstand the chemical attack that results from waste liquids or leachates;
be designed and constructed so as to withstand the stresses and disturbances
from overlying wastes, waste cover materials, and equipment operation; be
designed and operated to function without clogging through the scheduled
closure period; and be operated to collect and remove leachate through
the scheduled closure of the landfill or waste pile. Components should be
properly installed to assure that the specified performance of the leachate
collection system is achieved.
Design
The leachate collection and removal system should have:
(a) At least a 30 centimeter (12 inch) thick granular drainage layer that
is chemically resistant to the waste and leachate, with a hydraulic conductivity_
not less than 1 x 10"2 cm/sec with a minimum bottom slope of 2 percent.
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Innovative leacbate collection systems incorporating synthetic drainage layers
or nets rray be used if they are shown to te equivalent to or more effective tha
the granular design, including chemical cortpatibility, flow under load, and
protection of the flexible membrane liner (FML) (e.g., from puncture) if an
EML is included in the design.
(b) A graded granular or synthetic fabric filter above the drainage
layer to prevent clogging. Criteria for graded granular filters and for
synthetic fabric filters are found in numerous publications such as the
Geotextile Engineering Manual available from the Federal Highway Administration
and others. The granular drainage material should be washed to remove fines
before installation.
(c) A drainage system of appropriate pipe size and spacing on the bottom
of the unit to efficiently collect Ieachate. These pipe materials should be
chemically resistant to the waste and Ieachate. The piping system should be
enouch to withstand the weight of the waste materials and vehicular traffic
placed on or operated on top of it.
(d) The Ieachate collection system should cover the bottom and sidewalls
of the unit.
(e) A sump in each unit or cell should be capable of automatic and continue*.
functioning. The sump should contain a conveyance system for the removal of
Ieachate from the unit such as either a sump pump and conveyance pipe or gravity
drains.
(f) A written construction quality assurance (OQA) plan prepared by the
owner/operator to be used during construction of the liner system including the
leachaLe col lection dial leuuv/dl bysLem.—See SecLiou III, "Construction QuaiAty—
Assurance", for specific details.
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Construction
(a) The owner/operator siculd use the ccnstruction quality assurance
plan to monitor and document the quality of materials used and the conditions
and manner of their placement during construction of the leachate collection
and removal system. See Section III, "Construction Quality Assurance",
for specific details.
(b) The documentation for the OQA program should be kept on-site in the
facility operating record maintained for the landfill or waste pile unit.
Operation
The following operational procedures should be followed:
(a) The leachate removal system should operate automatically whenever leachate
is present in the sump and should remove accumulated leachate at the earliest
practicable time to minimize the leachate head on the liner (not to exceed
12 inches);
(b) Inspect weekly and after major storm events for proper functioning
of the leachate collection and removal system and for the presence of leachate
in the removal sump. The owner or operator should keep records on the system
to provide sufficient information that the leachate collection system is
functional and operating properly. We recommend the amount of leachate collected
be recorded in the facility operating record on each unit on a weekly basis;
(c) Clean out collection lines periodically; and
(d) A storage permit for collected leachate, if required.
B. Discussion
The Agency believes that practical designs for leachate collection and
removal ayatoms ran maintain a loar-hat-^ ctepth of one foot or less, excep_t
perhaps temporarily (for a few days) after major storms. The specifications
presented here, judiciously applied, are expected to accomplish that requirement.
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The :.iir.i:T_Lm thickness (2C ^ent^-etters or ^2 inches) of the drainage layer
allows sufficient cross sectional area for transport of drainage leachate. The
two-percent minimum slope is also intended to proncte drainage. In most cases,-
the Agency believes thicker drainage layers and greater slopes will be selected
owners and operators to maximize the efficiency of the leachate collection and
removal system. The hydraulic conductivity of not less than 1 X 10~2 on/sec was
chosen because materials widely used as drainage media are coarse enough that
their hydraulic conductivities are estimated to be 1 X 1CT2 cm/sec or greater.
It is not clear if the statutory requirements of §3004(o) (1) (A) (i) require
the primary leachate collection to be on the sidewalls of a landfill. The curre
Part 264 requirements in §264.251(2) and 264.301(2) require a collection and rem
system iinnediately above the liner to collect and remove leachate. The previous
single liner guidance dated July 1982, did not specify whether the leachate colli
system was only to cover the bottom or also the sidewalls of the unit. The Perm
Writer's Guidance Manual for Hazardous Waste Land Treatment, Storage, and Dispose
Facilities, October 1983, indicates that the need for a leachate collection syste
on the sidewalls at a landfill should be based on site-specific conditions on
expected leachate flow over the life of the facility. Generally, we encourage dr
installation of leachate collection systems on both the base and sidewalls. The
designs in this guidance recommend leachate collection system on the sidewalls
because it allows leachate to drain to the sump faster and minimize ponding of
leachate within the waste on 'the side of the liner.
The following is a list of factors that affect liquid transmission in
the leachate collection system drain layer:
* Impingement rate of-liquid-on the collection drain layer;
8 Slope of the drain layer;
* Diameter and spacing between the drainage pipes;
8 Coefficient of hydraulic conductivity of the saturated sand or
gravel drain layer; and _
0 Cleanliness (lack of fines) of the sand or gravel.
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A method for estimating quantity of liquids collected and aepth above the liner is
presented in Landfill and Surface Impoundment Performance Evaluation, SW-369,
April 1983 (EPA 1983).
Drain pipe diameter and spacing are inportant because they affect the
head that builds up on the liner between pipes. The closer the pipes are
together, the less the head. Also, the pipe diameter should be large enough
to efficiently carry off the collected leachate. Since the philosophy for
all aspects of liner design is to minimize liquid transmission through the
liner system, the head on the liner should be minimized. But the spacing
and size of the drainage piping system necessary to acconplish this depends
on other characteristics of the drainage layer (e.g., hydraulic conductivity)
and on the iirpingement rate of liquids, vduch is a function of precipitation.
The Agency is, therefore, not specifying minimm spacing or pipe diamet«r in
this guidance. However, EPA believes that designs incorporating 6-inch
diameter perforated or slotted pipes spaced 50 to 200 feet (15 to 60 meters)
apart will effectively minimize head on the liner system in most cases.
Information on leachate collection is presented in Appendix V of Lining of
Waste Iirpoundment and Disposal Facilities, EPA 1983A. The owner or operator
should demonstrate through appropriate design calculations in his application
that the maximum one-foot head requirement will not be exceeded.
The leachate collection and removal system should be overlain by a graded
granular filter or synthetic fabric filter. The purpose of this is to prevent
clogging of the voids in the drain layer by infiltration of fines from the waste.
If a granular filter is used, it is important that the relationship of grain
sizes of the filter medium and the drainage layer be appropriate if the filter
is to fulfill its function to prevent clogging of the drainage layer and not
contribute to clogging. Criteria for graded-granular filters and for synthetic
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fabric filters are found in numerous sources such as:
Graded granular filters:
- Earth Manual. 1984. Bureau of Reclamation, U.S. Department of the
Interior. Government Printing Office, Washington, DC.
- Geotextile Enginnering Manual, Training Manual, Federal Highway
Administration.
Geotextiles:
- Koerner, Robert M., and J.P. Welsh. 1980. Construction and Geotechnical
Engineering Using Synthetic Fabrics. John Wiley and Sons, New York.
- Horz, R.C. 1984. Geotextiles for Drainage and Erosion Control at
Hazardous Waste Landfills. EPA Interagency Agreement No. AD-96-F-1-400-:
U.S. EPA, Cincinnati, Ohio.
- Geotextile Engineering Manual, Training Manual, Federal Highway
Administration.
Innovative leachate collection systems that are equivalent to, or more
effective than, the granular system described above may be used. These
innovative systems such as plastic nets can be very thin, on the order of
one-inch thick, and have the drainage capacity of a sand layer one-foot
thick. These systems should be capable of maintaining a leachate head of one
foot or less. The following criteria should be addressed for determining
equivalence:
0 Design
- hydraulic transmLssivity (i.e., the amount of liquid that
can be removed)
- compressibility (i.e., ability to withstand expected overburden
pressures while remaining functional)
- conpatibility (chemical) with waste liquid
- compatibility (mechanical) with the liner (i.e., will not
deform the FML under the expected overburden)
- slope stability.
0 Construction
- construction characteristics (i.e., ease of construction).
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15
0 Operation/performance characteristics
- drainage or flow characteristics (i.e., how fast liquids will
flow and what volume will flow)
- time required to return the leachate head to one foot or less
after a rainfall event
- material creep
- useful life of system
- ability to resist clogging
- ability to verify performance.
An owner or operator wishing to use a leachate collection system other than
the recommended one should compare the properties of his design against the
recommended design using the above criteria. If equivalent or better, he
should proceed; if not, he should abandon the alternate design. If one or
more of the factors is not equivalent, the collection system will probably
not perform well, and will potentially become a source of constant trouole
to its owner/operator.
If a waste pile is very small a separate drainage layer below the waste
may not be needed. Instead, merely using a liner and sloping the liner so
that any leachate will flow to a sump that provides leachate collection and
removal and meets the maximum one-foot head requirement is adequate.
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16
II. Liner Specifications
Contents
Page
A. Guidance 16
Requirements 16
Design 17
a. Disposal 18
b. Storage and treatment 22
Construction 24
a. FML 24
b. Low permeability soil 25
Operation 32
B. Discussion 33
A. Guidance
Regulatory and Statutory Requirements for Overall Design, Construction,
and Operation
For interim status waste piles, at least one liner must be installed
for new units or replacement or lateral expansion of an existing unit.
Permitted waste piles must have a single liner that meets §264.251(a)(1).
Both interim status and permitted waste piles that are inside or under a
structure are not subject to the liner requirements. One liner is also
required at tine of permit issuance for those portions of existing units at
landfills and surface impoundments that are not covered by waste at the
time the permit is issued. The liner must be designed, constructed, and
installed to achieve containment of the waste in the liner during the active
life of the unit, thus preventing the escape of hazardous constituents. The
liner for a disposal unit must be designed and constructed of materials to
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1 /
prevent the migration of any hazardous constituents into such liner except
for de minimus infiltration of waste constituents during the active life of
the unit (including the closure period). For a storage unit (i.e., a pile
or surface inpoundment from which wastes and waste residue will be removed
or decontaminated at closure), the liner may be constructed of materials
that nay allow wastes to migrate into the liner but not into the adjacent
subsurface soil or ground water or surface water at any time during the
active life (including the closure period) of the unit. The liner materials
must be resistant to the hazardous constituents the liner will encounter,
and be of sufficient strength and thickness to withstand the forces it will
encounter during construction and the active life. The foundation must be
prepared to ensure that the structural stability of the subgrade is sufficient
to support the liner and to prevent failure due to pressure gradients. The
liner must cover all areas likely to be exposed to waste and leachate.
Design
e This liner system should be constructed conpletely above the seasonal
high water table (i.e., in unsaturated soil).
0 Liners for disposal surface inpoundment and landfill units should oe
designed with a single flexible membrane liner (FML).
0 The liner for storage or treatment inpoundments, and storage piles
where the waste will be removed at closure should consist of a single FML
or ccnpacted low permeability soil liner.
' The following are single liner specifications which the Agency
believes will produce stable construction and which will prevent the release
of hazardous constituents. : :
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13
(a) A FML liner:
(1) The FML should be of at least 30 mils thick; however, if the liner
is to be exposed to the weather for an extended period before it is covered
by a protective soil layer or the waste, or if the liner is to be operated
without a protective cover, it should be at least 45 mils in thickness.
Many units will require a thicker liner to prevent failure while the unit is
operating, including any closure period. The adequacy of the selected thickne
should be demonstrated by an evaluation considering the type of FML material
and site-specific factors such as: expected operating period of the landfill
or surface impoundment unit, pressure gradients, physical contact with the
waste and leachate, climatic conditions (environmental factors), the stress
of installation, and the stress of daily operation (e.g., placing wastes in
the landfill or sludge removal in surface impoundments}* Stresses tend to
be higher for surface impoundment units than for landfill units. Several
factors can increase liner stresses in surface impoundments such as: (1)
cleaning or maintenance activities; (2) thermal stress; (3) hydrostatic
pressure (head and wave action); (4) abrasion; (5) weather exposure (ultraviole
light, oxygen, ozone, heat, and wind); and (6) operating conditions (inlet
and outlet flow, active life, exposure to animals, treatment processes).
Because of these factors, uncovered surface impoundments generally require
thicker liners than the 45 mil minimum. Thicknesses of 60-100 mils have
teen necessary in some applications. A protective layer covering the liner
in surface impoundments can reduce the stresses on the liner. The Agency
will consider appropriate historical data and actual test data regarding the
performance of liner materials of the designed thickness as part of the
evaluation of the permit application.
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19
(2) Liners must be chemically resistant to the waste and leachate
managed at the unit. Generally, test data will be required because the
demonstration of chemical resistance should be based on representative waste
effects. The EPA Test Method 9090 (October 1, 1984, proposal or revised
editions) or an Agency approved equivalent test method should be used to
test chemical resistance of liners. Complete copies of Test Methods for
Evaluating Solid Waste which contains the sampling and analytical methodologies
addressed in the October I, 1984, proposed rules (including Method 9090) are
available from the National Technical Information Service (OTIS), 5285 Port
Royal Road, Springfield, Virginia 22161, (703) 487-4650. The document number
is PB-85-103-026. In judging chemical compatibility of wastes and membranes,
the Agency will consider appropriate historical data or actual test data if
obtained under longer or more severe.test conditions*
(3) The National Sanitation Foundation (NSF) presents liner material
properties and factory seam requirements in their Standard Number 54 for Flexible
Membrane Liners, November 1983. The Agency suggests that material and seam
specifications such as those in the National Sanitation Foundation standard be
used to assure material quality from the liner manufacturer. Liner materials
listed by the National Sanitation Foundation for industrial service, or liner
materials that are not listed but consistently meet the specifications of the
NSF Standard 54, are acceptable for assuring quality from the manufacturer.
Test methods used to estblish these requirements should comply with applicable
American Society of Testing and Materials (ASTM) procedures, recommended methods
in EPA document SW-870 Lining of Waste Iirpoundment and Disposal Facilities (tables
VIII-1 to 7) (EPA 1983a), or an equivalent method when available.—The-FMLs
covered by NDF Standard 54 include at least the following:
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Tl
0 Jciyvinyl Chloride (?VC)
" Pclyvinyl Chion.de Oil Res is cant (7VC-GR)
0 Chlorinatea Polyethylene (CPE)
* Butyl Rubber (IIR)
0 Polychloroprene (CR)
0 High Density Polyethylene (HDPE)
0 Ethylene-Propylene Diene Terpolymer (EPDM)
0 Epichlorohydrin Polymers (CO)
6 Polyethylene Ethylene Propylene Alloy (PE-EP-A)
0 High Density Polyethylene Elastomeric Alloy (HDPE-A)
0 Chlorosulfonated Polyethylene (CSPE)
0 Chlorosulfonated Polyethylene, Low Water Absorption (CSPE-LW)
8 Thermoplastic Nitrile - PVC (TN-PVC)
0 Thermoplastic EPDM (T-EPDM)
0 Ethylene Interpolymer Alloy (EIA)
0 Chlorinated Polyethylene Alloy (CPE-A)
The address for the National Sanitation Foundation is:
3475 Plymouth Road
P.O. Box 1468
Ann Arbor, Michigan 48106 USA
(4) FMLs should be free of pinholes, blisters, holes, and contaminants,
which include, but are not limited to, wood, paper, metal, and nondispersed
ingredients.
(5) The compounding ingredients used in producing FMLs should be first
quality, virgin materials providing durable and effective fornulations for
liner applications. Clean rework materials containing encapsulated scrim or
other fibrous materials should not be used in the manufacture of FMLs used
for hazardous waste containment. Clean rework materials of the same virgin
ingredients generated from the manufacturer' s own production may be used by
the same manufacturer, provided that the finished products meet the material
specification requirements.
(6) FMLs in landfill and waste pile units, and in surface impoundment
units with the minimum i-onotmqnded thickness, should be protected from damage
from above and below the membrane by a least 30 centimeters (12 inches)
nominal, 25 centimeters (10 indies) miniitum of bedding material (no coarser
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than r;nifieci Soil Classification System (USCS) sand (SP) with 100 percent cf
the washed, rounded sand passing the 1/4-inch sieve) that is free of rock,
fractured stone, debris, cobbles, rubbish, and roots, unless it is known
that the FML material is not physically inpaired by the material under load.
The surface of a completed substrate should be properly conpacted, smooth,
uniform, and free from sudden changes in grade. A low-permeable soil may
serve as bedding material when in direct contact with FMLs if it meets the
requirements specified herein. Polymeric materiala such as geotextiles and
synthetic drainage layers may also serve as bedding materials when in direct
contact with either surface of the FML, if they provide equivalent protection.
In determining equivalent protection given by geotextile or other specific
materials, the Agency will consider historical data and actual test data
that relate to site-specific conditions. To demonstrate that a synthetic
drainage layer can serve as bedding material, it should be shown that the
synthetic drainage layer does not exhibit brittle failure under overburden
stresses and stresses caused by equipment used for construction or waste
placement.
Note: In most cases a F74L should not be in contact with native, in
situ soil.
Note: Light geotextile bedding material may require an additional
precaution if the slopes are exposed to high velocity winds.
(7) For surface impoundment and landfill units in which the sidewalls
will be uncovered and exposed for extended periods before wastes are placed,
the design of the bedding material used below the liner should be highly
permeable and include gas venting if the potential for gas generation under
the liner exists, or if the slopes or a surface iitpoundment will be
exposed to high velocity winds.
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ti.ne to Breakthrough: liner thickness, water content, capillary forces, and
unsaturated hydraulic conductivity at various depths in the liner over tinre.
Conservative assumptions should be used in estimating the necessary liner
thickness to prevent migration of any constituent through the conpacted low
permeability soil bottom liner. Examples of assurrptions that should be made
are as follows:
(i) Inpingement rate on the liner would be equivalent to the rate of moisture
infiltration into the waste pile, and, for surface impoundments, the head
would be equal to the maximum operating head for the impoundment;
(ii) Leakage into the liner would occur throughout the active life;
(iii) Nature and quantity of the waste would be considered;
(iv) Any allowance for attentuation should take into account the nature of the
waste and any factors that may reduce attenuation.
(v) The effective porosity would be 0.05; and
(vi) The compacted low permeability soil liner and adjacent soil strata would
be initially unsaturated.
The compacted material must be free of rock, fractured stone, debris, cobbles,
rubbish, and roots, that would increase hydraulic conductivity or serve to
promote preferential leachate flow paths.
(2) The owner/operator should document methods used to estimate the
necessary liner thickness. These evaluations should also cover the following:
(i) Horizontal hydraulic conductivity within and between the individual
lifts (Brown et al, 1983 Boynton, 1983);
(ii) Variability in the hydraulic conductivity of the compacted soil liner
in the field (Eaniel, 1984);
(iii) The potential for long term changes in hydraulic conductivity resulting
from loss of moisture by the liner due to climatic conditions or the
equilibrium moisture content in the adjacent soil deposits; and
(iv) The effect of liner aging on the long term equilibrium hydraulic
conductivity of the liner (Mitchell et al, 1965; Dunn and Mitchelll
1984. Boynton, 1983).
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(3) The foundation subsoil that underlies the soil liner should be
structurally immobile during construction and operation of the unit (including
any closure period).
(c) The owner/operator should prepare a written construction quality
assurance plan to be used during construction of the liner system. Section
III, "Construction Quality Assurance," should be used to assure that the
conpleted liner system meets the design criteria and specifications.
Construction
8 The earth substrates and base materials should be maintained in a
smooth, uniform, and compacted condition during installation of the liner
and components*
0 Waste pile, surface impoundment, and landfill units should be constructed
with liners that meet the following, as a minimum:
(a) FML liners:
(1) The liner should be installed (seamed) at ambient temperatures within
the range specified by the manufacturer of the particular liner. Temperature
extremes may have an effect on transportation, storage, field handling,
placement, seaming, and backfilling (where required).
(2) When the field seaming of the FML is adversely affected by moisture,
portable protective structures and/or other methods should be used to maintain
a dry sealing surface.
(3) Liner installation should be suspended when wind conditions may
adversely affect the ability of the installers to maintain alignment of
seams and integrity of membranes and seams.
(4) Field seaming of FMLs should be performed when weather conditions
are favorable. The contact surfaces of the FML should be free of dirt,
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25
dust, and moisture including films resulting from condensation in weatner
conditions of high humidity. Seams should be made and bonded in accordance
with the supplier's recommended procedures. Both destructive and nondestructive
testing methods should be used to evaluate seam integrity. All on-site
seams should be inspected by nondestructive testing techniques to verify their
integrity. Periodic samples should be removed from both factory and field
seams and tested for seam integrity by destrictive tests (tension and peel
tests). On-site nondestructive seam samples should be made and evaluated with
identical liner material, adhesive/ and technique prior to actual field seaming
each day, or when conditions change.
(5) Proper equipment should be selected in placing bedding material
over FMLs to avoid undue stress.
(b) Low permeability soil liners:
(1) EPA is conducting studies to evaluate the construction criteria
that most significantly influence the hydraulic conductivity of compacted
low permeability soil liners. Until specific research and/or demonstration
data are available, the following are suggested as the best available procedures
for optimizing construction of compacted soil liners:
(i) Remove all lenses, cracks, channels, root holes, or other structural
nonuniformities that can increase the nominal in-place saturated hydraulic
conductivity of the liner above 1 X 10~^ cm/sec.
(ii) Construct the liner in lifts not exceeding 15 centimeters (6 inches)
after compaction to maximize the effectiveness of compaction throughout the
lift thickness. Each lift should be properly interfaced by scarification
between lifts.
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26
(iii) Scarify sufficiently between each lift so as not to create a zone
of higher horizontal hydraulic conductivity at the interface of the lifts.
(iv) Break up clods and homogenize the liner material before conpaction
of each lift using mixing devices such as pug mills or rotary tillers. All
oversized materials (such as trash, large roots, wood, or large clods) should
be removed in order to facilitate moisture control operations, maximize
conpaction, reduce heterogenity, and minimize overall hydraulic conductivity
of the corpacted liner.
(v) Thoroughly mix in moisture needed to bring the liner to the desired
water content using mixing devices such as pug mills, rotary tillers, or
other effective methods.
(vi) Compact the liner after allowing a sufficient time for added water
to penetrate to the center of the larger diameter clods while not allowing
so much time after water addition that the exterior of the larger clods
becomes drier than optimum. The larger clods should be field checked for
moisture distribution.
(vii) Take the necessary precautions to assure that the desired moisture
content is maintained in the compacted liner to avoid desiccation crackinq.
Precautions that are effective at preventing desiccation cracking should be
taken both between the placement of lifts and after completion of the liner.
(viii) Construction should not take place using frozen or other indurated
soil/ and precautions should be taken to assure that the liner is not allowed
to freeze after placement.
(ix) Sidewalls should be constructed so as to minimize flow between the
lifts. EPA believes this can best be accomplished with lifts that are laid
down parallel to the slope.
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27
(x) A demonstration should be made that sidewalls can be effectively
compacted at the maximum slope to be used in the design. The Agency suggests
a maximum slope of 3 horizontal to 1 vertical.
(XL) Consideration should be made of the vector of compactive effort
when calculating the number of passes necessary to obtain a certain degree
of compaction on sidewalls.
(xii) The uppermost lift should be scraped and steel rolled to produce a
smooth surface prior to placement of the leachate collection and removal system.
(2) EPA recommends that a representative test fill be constructed using
the soil, equipment, and procedures to be used in construction of the compacted
low permeability soil liner in the full scale facility. The test fill should
be used to verify that the specified density/moisture content/hydraulic
conductivity values can be consistently achieved in the full scale facility.
Test fills have been used to validate both design and construction procedures
for critical earthen structures around dams and nuclear power plants. In
order for the data collected from the test fill to be useful, however,
construction control of the test fill must be strict and well documented.
Previously-developed data that describes the performance of an installed
liner can be used, provided documentation is available on all the factors
discussed above. EPA is not, however aware of any facility that currently
has this data on hand.
All information gathered during construction and subsequent testing of
the test fill should be documented. The CQA program to be followed during
construction of the full scale facility should be strictly followed during
construction of the test fill (Corps of Engineers, 197T)~. Recommended" minimum
test fill construction details are as follows:
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28
(i) Construction using the same compactable materials, compaction equicm
and exact procedures as will be used to construct the full scale facility lin
All applicable parts of the quality assurance plan should be precisely follow
to monitor and document construction of the test fill.
(ii) The test fill should be constructed at least four times wider than tfr
widest piece of equipment to be used in construction of the full scale facilit
(iii) The test fill should be long enough to allow construction equipment t
reach normal operating speed before entering the area to be used for testing
(see Figure 5).
(iv) Construction so as to facilitate the use of field hydraulic conductiv
tests and/or a complete quantification of all underdrainage. Field hydraulic
conductivity tests should be conducted on the compacted test fill material as
a verification of results of laboratory tests conducted on undisturbed samples
taken from the compacted- test fill material. The field hydraulic conductivity
tests need only verify that the hydraulic conductivity i& 1 x 10~7 cm/sec or le
not its actual value. These undisturbed samples can then be used for compacted
liner/leachate compatibility testing.
(v) Construction so as to determine the relationship of the following to
the moisture content/density/hydraulic conductivity values obtained in the fielc
0 Compaction method (detailed specifications of the compaction equipment);
0 Number of passes of the compaction equipment;
0 Mixing method (and resulting maximum clod size);
0 CcniMCtion equipment speed; and
4 Uhconopacted and compacted lift thickness.
(vi) A set of index properties should be selected that will be used to monitc
and document the quality of construction obtained in the test fill. These inde>
properties should include at least the following:
Hydraulic conductivity (undisturbed samples);
In-place density and water content;
Maximum clod size;
Particle size distribution; and
Atterberg limits.
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>>»»>))»>»»»» >»»»»))
LEAST THREE SIX-INCH THICK LIFTS OF COMPACTED SOIL
DRAINAGE LAYER OR UNDERDRAINAGE COLLECTION SYSTEM
a.
C
0>
u»
Ul
a.
3
2:1 SLOPE
L- DISTANCE REQUIRED FOR CONSTRUCTION EQUIPMENT TO REACH NORMAL
NNING SPEED
W- DISTANCE AT LEAST FOUR TIMES WIDER THAN THE WIDEST PIECE OF
CONSTRUCTION EQUIPMENT
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30
Data from these tests shall be used as standards for comparison with values
obtained on samples from the full scale liner to indicate inplace field
hydraulic conductivity.
(3) All lifts of the compacted low permeability soil liner that are
part of the 3-ft minimum thickness, should have an in-place hydraulic conduct
of 1X10~7 cm/sec or less. This hydraulic conductivity value should be
verified both in the test fill liner and by comparison of index property
values between the test fill and each lift in the full scale liner. The valu<
obtained should be numerous enough to fully document the degree of variability
of all the index properties in both the test fill and each lift in the full
scale liner.
Conservative assumptions should be used in estimating the compacted low
permeability soil liner thickness because of the lack of precision with which
such estimates can be made. There are several difficult to estimate variables
that affect the thickness needed to prevent migration of hazardous constituent
over the operational life of the soil liner. Examples of the conservative
assumptions that should be used to estimate soil liner thickness are as follow:
1. The leakage/impingement rate of leachate to the soil liner should
be based on an estimate of active life and closure period conditions.
For waste piles during the active life the leakage into the compacted
soil liner should be based on the rate of moisture/liquid infiltration into
the waste pile considering (1) leachate collection and removal by the leachate
collection system under proposed removal conditions, and (2) the compacted
soil liner surface conditions.
~ For treatment and storage surface impoundments during the active 1 tfe
the leakage rate into the compacted soil liner should be based on (1) the
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31
maximum designed operating head for the inpoundment, and (2) the compacted
soil liner surface conditions.
2. Nature and quantity of the waste should be considered.
Volume of leachate released by the waste as decomposition by-products will
depend on the total organic content of the waste. The higher the organic content
of a waste, the greater would be the fraction of the waste which could be liquifiec
during its decomposition. The total quantity of organic materials in the facility
would affect the total volume of leachate that could eventually be generated from
decomposition of the waste.
Composition of a waste will affect the composition of the leachate. High
concentrations of certain leachate components may increase the rate at which a
soil liner transmits leachate (Anderson, 1982). If a waste has a flow rate through
the compact soil liner faster than water this should also be considered in the
evaluation of required liner thickness.
3. Any allowance for attenuation of the waste constituents by the soil
liner should take into account the nature of the waste and any factors
that may reduce attenuation.
Some waste constituents (such as cations) can be strongly attenuated by
soils under ideal conditions (EPA, 1983c). The extent to which many of these
are attenuated can, however, be greatly decreased in the acidic and anaerobic
conditions that are often present near soil liners. Other waste constituents
(such as anions) nay not be appreciably attenuated by soil. Movement of waste
constituents^will also be affected by the effective porosity of the soil liner.
There are a number of other conditions under which attenuation can be greatly
reduced. In addition, the conditions that optimize attenuation of one constituent
may promote leaching of another (Lindsey, 1979).
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32
4. The effective porosity would be 0.05.
Total porosity of a contacted soil will usually be less than 0.5
(Anderson et al., 1984; and Brown and Anderson, 1983). Effective porosity
can be much less than total porosity in fine-grained soils (Gibb et al., ~
1985). Green et al., (1985) found that in some compacted sanples only 10% of
the total porosity was effective in transmitting liquids. Ten percent of
even the highest total porosity likely in a compacted specimen would result
in an effective porosity of no greater than 0.05.
5. The compacted low permeability soil liner and adjacent soil strata
would be initially unsaturated.
Design criteria given elsewhere in this document state that the "liner
system should be constructed completely above the seasonal high water table
(i.e., in unsaturated soil)." Under these conditions, the soil strata
immediately adjacent to the liner would probably also be unsaturated.
(c) The owner/operator should implement a written quality assurance
plan to monitor and document the quality of liner materials used and the
conditions and manner of their placement during construction. See Section III
"Construction Quality Assurance", for specific recommendations.
(d) The documentation for the CQA program for construction of the liner
should be kept on-site in the facility operating record.
Operation
The following operational criteria are suggested:
(a) The placement of removable coupons of the FML (if this type of liner
is used) above the top liner is a technique for providing waste/liner chemical
compatibility infonnation during the operating period. Coupons are samples
of the FML used in the construction of the liner that are placed in contact
with wastes or leachate in the landfill, waste pile, or surface impoundment.
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33
The coupons are tested after various exposure periods in the unit to determine
how the properties of the liner change over the active life. This information/
when compared to short-term compatibility data, can provide an early warninq
that the liner is degrading faster than anticipated and allow for corrective
measures by the owner. The Agency recommends that landfill, waste pile, and
surface impoundment owners consider removable coupon testing if wastes are
likely to vary somewhat during operation.
(b) The owner should have on-site guidelines for operation and maintenance
of the liner system, which include recommendations on such subjects as:
- Frequency and documentation of inspection,
- Testing and repair of liner,
- Animal and plant control,
- Erosion control,
- Unacceptable practices,
- Placement of waste, and
- Coupon test schedule (optional).
B. Discussion
The EPA believes that a FML should meet the following criteria:
- A minimum thickness depending on the service;
0 For buried FMLs the minimum thickness should be 30 mils when the
membrane will be covered within three months by a protective layer
against mechanical and weather conditions.
0 For membranes that will be buried, but left unprotected for periods
greater than 3 months, the minimum thickness should be 45 mils.
0 For all liners used in impoundments that are left uncovered and
exposed to the weather and experience light work on the surface,
the minimum thickness should be 45 mils.
• The thickness of scrim layer, geotextile backing, or other
reinforcing material should not be used in computing a minimum
reoommendation.
0 For many units, particulary surface impoundments with exposed
surfaces, FMLs of 60-100 mils may be required to meet the mechanical
stress requirements.~
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34
3 The stresses on exposed liners are generally greater for surface
impoundments because of exposure to more severe environmental
conditions (climate)/ loading and unloading during daily operati
and sludge removal. Because of the more severe operation condit
surface impoundments require substantially thicker liners. A
protective layer covering the liner can reduce the stresses on
the liner.
- Sufficient strength to prevent failure due to pressure gradients
(including static head and external hydrologic forces, stresses of
installation, and the stresses of daily operation);
- Compatibility with the waste to be managed in the unit;
- Low permeability; and
- Capable of being seamed to produce high-strength, liquid-tight seams
that retain their integrity during liner installation and on exposure
to wastes for the duration of the operating life of the unit, includi
the closure period.
One of the primary reasons for failure of synthetic liners is damage
(i.e., punctures, rips, and tears). Damage occurs during installation and/or
during operation. The owner/operator needs to demonstrate that the selected
FML thickness is adequate for the site-specific conditions the liner will
encounter while the unit is in operation (including any closure period).
EPA believes thickness and strength of the liner material are major
factors in maximizing serviceability and durability. However, the lack of
current technical data relating liner thickness for specific material types
to successes and failures of liner systems prevents more specific guidance
on thickness. The following is a list (EPA, 1983) of potential failure
modes that should be considered in selecting the FML polymer type and thickness
to maximize liner serviceability and durability:
Physical Modes of Failure
Abrasion
Creep
Differential settling
Hydrostatic pressure
Puncture
Stress-cracking (partly chemical)
Tear stress
Thermal stress
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35
Chemical Modes of Failure
Extraction of plasticizer and soluble ingredients
High pH>10
Hydrolysis
Attack by ionic species
Low pH<2
Ozone-cracking
Attack by solvents and organic chemical species
Ultraviolent light attack
Biological Modes of Failure
Microbial attack (of plasticizers in FML compounds)
Liner failure mechanisms are addressed in a U.S. EPA Technical Resource
Document/ Lining of Waste Impoundment and Disposal Facilities, SW-870,
March 1983. This document describes and discusses the categories and charac-
teristics of liner failure in a service environment. The document is available
from the U.S. Government Printing Office, publication number S/tt 055-000-00231-2,
$11.00, Superintendent of Documents, Washington, D.C. 20460. Kays (1977)
also provides detailed discussion en liner failure mechanisms and methods to
avoid failures for cut-and-fill reservoirs.
To help guard FMLs against damage, such as punctures, tears, and rips
due to contact with sharp objects or other conditions, it is good practice to
protect them from above and below by a minimum of 12 inches of bedding material.
In landfills, the act of placing wastes sometimes causes damage (e.g., due to
dropping of wastes or driving of vehicles on the liner) ; also, over extended
time periods the wastes themselves may be capable of causing damage to the
FML and to the leachate drainage and collection system because they contain
sharp objects or abrasives.
landfill nnil-q, a Iparhat-a rtrainaqft and ffQilerfcinn and removal __
system must be placed above the liner. This layer can be made of materials
that meet both bedding and drainage material requirements. However, EPA
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36
suggests that for these units an additional layer of bedding material be
installed above the top filter layer as well as below the FML, unless it is
known that the FML is not physically impaired by the materials and operating "
practices. The drain pipes in the collection system should be adequately
protected against damage caused by waste placement and/or equipment operating
on the working surface.
Bedding layers should consist of materials that are no coarser than
sand (SP) as defined by the Uniform Soil Classification System (USCS). Use
of a sand layer is cannon practice for protection of membranes and pipes
from damage due to contact with grading equipment and materials, sharp material
in the soil, etc.
For surface impoundments, a bedding layer above a FML also protects the
FML from damage due to exposure to sunlight and wind while the unit is in
operation. However, the bedding material is not always necessary above the
top liner, since direct contact with the liquid wastes does not represent
the same potential for puncture that is present in landfills. Nevertheless,
the liner can be damaged, for example during sludge removal, other dredging
operations, or normal operating practices. Where mechanical equipment is
used, EPA recommends a minimum of 45 centimeters (18 inches) of protective soil
or the equivalent covering the liner, unless it is known that the FML will not
be damaged by the sludge removal practices. Some FML materials are known to be
degraded by ultraviolet radiation and must be covered. Also, wind can get undei
the edge of exposed FMLs, causing flapping and whipping, which can lead to tear;
These problems have occurred most camionly above the liquid level near the edge
of the FML. As a result, it is carmen practice to cover FMLs with 6 to 12 inch*
of earthen material to prevent degradation due to sunlight and to hold the linei
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37
down. The edges of FMLs are usually secured by anchor trenches at their perimeter
Of course, if the design is such that wind creates no difficulties, and if it is
known that the FML is not subject to solar degradation, then these precautions
are not necessary. The addition of a cover over the FML is expected to extend
the service life of the liner.
Chemical testing of all construction material corrponents is prudent
because liners can be degraded by certain chemical species that may be present
in the waste. Because wastes and liner chemical characteristics are almost
infinitely variable, it is difficult to generalize concerning incompatibility
or compatibility. The Agency/ therefore, strongly suggests (and prefers)
test data as the appropriate way to demonstrate the compatibility of the
waste to be managed and the liner materials under consideration. Test results
should demonstrate the acceptability of the selected liner materials. New
test data may not be needed for units that have a well defined waste composition
and for which previous test data showing that the proposed liner chemical
characteristics are very predictable.
Waste liner material compatibility tests should be conducted using
representative samples of wastes and leachates to which the liner is to be
exposed. Several methods for obtaining samples of hazardous waste are discussed
in Section one of Test Methods for Evaluating Solid Waste (SW-846).
An acceptable test method for assessing the compatibility of waste
liquids and FMLs is the "Immersion Test of Membrane Liner Materials for
Chemical Compatibility with Wastes," found in EPA's Method 9090. In this test,
samples of the candidate FMLs are immersed at two temperatures in samples
of the waste liquid to be managed and exposed for four months. After exposure
for one-month intervals, a FML sample is tested for important strength
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38
characteristics (tensile, tear, and puncture) and weight loss or ..ain. The
Agency ccnsiders any significant deterioration in any of the measured propertie
to be evidence of incorrpatibility unless a convincing demonstration can be
made that the deterioration exhibited will not inpair the liner integrity !
over the life of the facility. Even though the tests may show the amount of
deterioration to be relatively small, the Agency is concerned about the
cumulative effects of exposure over very nuch longer periods than those
actually tested.
At present, no standard test method is available for assessing the
compatibility of specific low permeability soils with a given waste liquid.
Nevertheless, the compatibility of a soil with a waste liquid has been measured
by conparing the permeability of the soil to water and to the waste liquid.
The Agency incorporated the National Sanitation Foundation's (NSF)
standard specifications fox flexible membrane liners into this guidance to
provide suggested minimum values for physical properties. A NSF committfie has
been studying the subject for some time, and EPA believes that the specifications
developed are reasonable and well thought out. Compliance with the NSF
standard attests only to the basic quality of the liner itself and not to
the advisability of its application under any given set of waste and unit-
specific circumstances.
A EML is required to be designed to prevent migration of constituents
of the wast« liquid into the liner during the active life of the unit (including
the closure period) except for de minimis leakage. CPA recognizes that
membranes will not always have zero leakage and that de minimis leakage may
occur. De minimis leakage can occur as a result of vapor passing through the
liner, very small imperfections in the liner that occur very rarely, or a seam
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41
(1) There are no clear criteria or techniques available for making breakthrough
determination. While several methodologies have been suggested, the Agency is not
aware of any methods which have undergone rigorous field-verification testinc,.
(2) It is not clear whether it would be economically feasible to construct
a low permeability soil liner thick enough to prevent breakthrough during the
active life of the unit assuming adequate flow from the overlying waste pile or
surface inpoundment to maintain continuous unsaturated (capillary) flow through
the soil liner.
(3) Hydraulic conductivities of 1 X 10"? cm/sec or less have not been routinely
and consistently obtained in the past on an overall in-field scale liner system.
A number of studies have suggested that actual field scale hydraulic conductivities
may be in the range of 10 to 1000 times higher than the 1 X 10~7 to 1 X 10"8 on/sec
values that are routinely obtainable in laboratory tests. The Agency believes that
if a testfill (described in the section on construction of low permeability soil)
is used, a hydraulic conductivity of 1 X 10"? can be achieved in the liner.
(4) The capability of current testing methods to verify with a high degree of
confidence the actual field performance of a compacted low permeability soil
liner has not been demonstrated.
Consequently, the Agency currently believes that the best method would include
construction of a test fill and the collection of field hydraulic conductivity
data.
Minimizing the flux of liquid through the conpacted soil to prevent break-
through can be accomplished as follows:
(1) minimizing the hydraulic gradient under which leachate will move; and
(2) minimizing hydraulic conductivity of the conpacted soil.
There are tvo ways to minimize the hydraulic gradient: 1) reduce the depth of
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standing liquids in ti'r.a Leacoate collection syste.-rs; and 2) construct a thicke
ccnpacted soil liner. Besides lowering the hydraulic gradient, constructing a
thicker ccnpacted liner should reduce the probability that a blemish of any kii
would penetrate all the way through the conpacted soil. ]
Whether referred to as blemishes, macrofea tares, or structural non-unifor-
mities, construction imperfections may increase the overall saturated hydraulic
conductivity by several orders of nnagnitude. Methods to reduce actual in-the-
field hydraulic conductivity of a conpacted soil should be included in the
construction inspection program to both prevent and detect these imperfections.
Details of the infornation that should be gathered before, during, and after
construction of a conpacted soil (which should serve to reduce the number of
these inperfections) are given under "Construction Quality Assurance" (section
Hydraulic conductivity testing on the in-plaoe conpacted low permeability
soil is reconmended because of concern that laboratory tests tend to underestirrv
the actual hydraulic conductivity in the field by a factor of 10 to 1000. The
following recent references discuss the causes and magnitude of differences
between field-measured and laboratory-measured hydraulic conductivity:
0 Daniel, D. E., 1984. Predicting Hydraulic Conductivity of Clay Liners.
ASCE, Journal of Geotechnical Engineering, 110(2) : 285- 300.
9 Griffin, R. A. et. al. 1984. Migration of Industrial Chemicals and Soil-
Interactions at Wilscnville, Illinois. In Proceedings of the Tenth Annua
Research Symposium on Land Disposal of Hazardous Waste. (EPA 600/9-84-007
USEPA Municipal Environmental Research Laboratory, Cincinnati, OH 45268.
9 Herzog, B. L. and W. J. Morse. 1984. A Comparison of Laboratory and
Field DeLernilned Values of Hydraulic Conductivity at a Waste Disposal
Site, Iri Proceedings of the Seventh Annual Madison Waste Conference.
University of Wisconsin-Extension, Madison, Wisconsin, p. 30-52.
- " Boutwoll, G.C. and V.R. Donald, L982. — ronpart or? riay rin^r* for Industri
Waste Disposal, Presented ASCE National Meeting Las Vegas, April 26, 1982
One reason why higher hydraulic conductivities are often obtained with
field tests is that samples used in laboratory tests can be more readily
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39
that has a very small crack or hole. Although FMLs are nonporous-homoger.eous
materials vapor diffusion can transmit water and other liquids with dissolved
constituents through synthetic liners. The transmission involves 1) sorption
the constituents of the waste liquid into the membrane, 2) diffusion through the
FML, and 3) evaporation or dissolution of the constituents on the downstream
side of the membrane. The principal driving force for permeation through a FML
is the gradient across the liner in concentration/ chemical potential, or vapor
pressure of the individual constituents in the liquid or vapor. Permeability of
an individual permeant depends upon its solubility and diffusion characteristics
in a specific liner. De minimis leakage can also occur because of small and
infrequent breaches in the liner that were not detectable during construction
with current practical state-of-the-art construction quality assurance programs.
EPA believes that current state-of-the-art technology for FML installation
allows for hazardous waste management units to be built that will have very
low leakage rates at installation. EPA does not have a specific maximum de
minimis leakage rate that can be recommended. However, based on currently
available preliminary field data, laboratory test results, and professional
judgment, EPA believes that de minimis leakage should be approximately
1 gallon/acre/day or less. This rate should not be taken as a hard and fast
rule because there are conditions where vapor transmission potentially could
exceed this value. Also, this value does not apply to organic liquids, many
of which can permeate a FML independently of the water in waste liquid. Some
organic constituents can transmit at considerably higher rates than water,
if the organic constituents are soluble in the membrane and organic concentration
on the downstream side of the rnamfiraisr is essentially zero;—Dr. H. August-et al,
(1984), has shown laboratory permeation rates for concentrated hydrocarbons on
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40
1 mm thick HLPE FMLs were between 1 and 50g/m2/day varying with the waste chemical
structure and its affinity to the HCPE. Another finding of this study was that
very dilute hydrocarbon solutions sometimes give high permeation rates of the
hydrocarbons because of the relatively high solubility of the hydrocarbons compared
to water in the HDPE. The concentration of organic waste in the liner surface can
be higher by several orders of magnitude than the adjacent leachate or liquid
waste containing hydrocarbons. Current laboratory tests cannot be related directly
to estimate field rates of permeation because the tests do not simulate the ability
of soil under the liner to transport the waste away from the liner. (See the
suggested reading material list for additional information.) Review of information
from recently constructed double synthetically lined surface impoundments shows
that current state-of-the-art technology for installing synthetic liners is close
to achieving 100% containment efficiency. The liner installations studied had
extensive construction quality control to assure the seams did not leak.
Soil liners will normally be of clay. For purposes of this guidance, "compacted
soil" is not meant to include materials such as soil cement, lime soil mixtures,
or fly ash soil mixtures. EPA recoimends that an owner or operator who wishes to
install a compacted lew permeability soil liner to comply with the requirements of
§264.221(a) or 264.251(a)(l) use this guidance to determine the thickness of the
bottom liner. EPA's recommendation for soil liners is : (1) that it consist of a
minimum 90 centimeters (3 feet) of compacted soil with an in-place saturated hydraulic
conductivity of not more than 1 X 10~7 cm/sec; and (2) that it is sufficiently thick
so as to prevent any constituent from migrating through the bottom of the compacted
soil liner prior to the end of the closure period. In cases were the active life
of the unit covers an extended time period the Agency has reservations concerning
the likelihood that such a design is either economically or technically feasible.
Some of the issues underlying these reservations are as follow:
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prepared without the defects that can greatly affect actual hydraulic conductivity.
Methods that are used to prepare soil liners in the field are difficult to
siirulate in the laboratory. One exanple is the method of conpaction. Soil
liners are often compacted in the field with a kneading action through the
use of sheepsfoot rollers. In contrast, soil liner sanples are usually
prepared in the laboratory using impact conpaction. Even though identical
densities nay be obtained with different methods of conpaction, the soil
sanples conpacted by different methods may have very different hydraulic
conductivities (Mitchell, 1976).
There are a variety of other reasons for the large discrepancies reported
between laboratory and field tests. Sanples prepared in a laboratory are
not subject to the climatic variables (such as cracking due to either freezing
or desiccation) (EPA 1984A). There way also be a tendency to run laboratory
tests on sanples of selected finer textured soil materials (Olson and Daniel
1981). It is often suggested, however, that the most inportant reason for
observed differences is that field tests can evaluate much larger and, hence,
more representative sanples than is practical in laboratory tests.
EPA believes that field hydraulic conductivity tests are essential to
verify the requirement to have an in-place hydraulic conductivity of 1X10~7
cm/sec or less. Currently available field hydraulic conductivity tests, if
conducted on the actual conpacted soil liner may, however, cause substantial
delays in construction and result in other problems due to prolonged exposure
of the liner. In addition, it would be extremely costly if it were determined
from field tests on the actual liner that it did not meet or exceed performance
standards. Much tima and effort, can Be saved if, prior to construction of—
the actual liner, a test section of the liner is prepared and tested. These
tests can be used to document the capability; of the proposed materials and
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44
construction procedures that result in a corrpaoted soil liner that rreets the
desired performance standards. Therefore, the EPA recornnends that a test
fill be constructed using the same borrow soil, compaction equipment, and
construction procedures as proposed for the full scale facility. The test
fill is also recommended for use in demonstrating the actual in-place hydraulj
conductivity of the compacted soil liner.
Test fills have been used by the geotechnical engineering community to
evaluate the design of soil liners used in cooling ponds for the nuclear
power industry. Test fills have also been used during the design stage of
dams to obtained information on engineering properties of the compacted soil
such as density, strength, and hydraulic conductivity (Barron, 1977).
Construction control of test fills mist be very strict and well dooznented
or the data obtained will be of questionable value (Corps of Engineers, 1977).
Field hydraulic conductivity tests of the compacted soil in the test fill
are necessary to assure that the materials and procedures used in the field
will result in a compacted soil liner with a hydraulic conductivity of 1X10"7
on/sec or lower. Field testing is not intended to preclude the use of laboratc
testing in the design or construction phase or as a means of evaluating
liner-leachate compatibility. It is expected that the overall design and
construction quality assurance (CQA) program will include a mixture of both
field and laboratory hydraulic conductivity tests.
As appropriate methods are developed and verified, the EPA intends to
require field hydraulic conductivity tests be conducted on the full scale
facility. Field hydraulic conductivity testa can be performed in the test
fill without causing delays during construction of the full scale facility.
The field test used should be capable of verifying that the hydraulic conducti\
of the compacted soil liner is 1X10"7 cm/sec or less.
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45
Field infiltroneters capable of measuring very low hydraulic conductivities
in conpacted soil liners have been developed and reported by Anderson et al
(1984), Day (1984) and Day et al (1985). An alternative to the use of field
infiltrometers is the use of a system for capturing and collecting all under-
drainage fron the test fill. Day (1984) used such an underdrain to evaluate
the accuracy of results obtained from field infiltrometers. While the field
infiltrometers were found to accurately measure hydraulic conductivity, the
underdrain was considered even more accurate.
Both infiltration and underdrainage tests should be conducted until
stable flow and/or drainage rates are obtained. Where infiltrometers are
used, there should be enough replicate tests to document area! variability
in the hydraulic conductivity of the liner to the test fill. A sufficient
number of index property tests (listed earlier in this section) should be
conducted to accomplish the following:
(1) verification of the aspects of the OQA plan related to conpacted
soil liners; and
(2) document the degree of variability in each of the properties tested
in the compacted soil liner for both the test fill and full scale
facility.
In addition to being used as a site for field hydraulic conductivity
tests, the test fill should be used to verify all elements of the design and
construction of the soil liner. These elements should include at least the
following!
(1) verification that the proposed soil material is uniformly suitable
to be conpacted into a liner (i.e. no cobbles, sand lenses, or indurated
materials).
(2) verification that the equipment and procedures for breaking up
cl
consistently achieving the required hydraulic conductivity specifi-
cation.
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-tO
(3) verification tiiat tiie CGA plan is sound in all respects. The prcpos
CQA. plan for construction of the full scale facility should be
followed exactly as applied to construction of the test fill. If
methods to iitprove the CQA plan are documented during construction
and testing of the test fill, these inproveitients should be incorpors
into the CQA program inplemented during full scale facility construe
Technical personnel who will be in charge of day to day inplementation '
of the OQA plan on the full scale facility should also monitor and thoroughly
document construction and testing of the test fill. This docunentation
should include at least the following:
(1) a detailed description of for the type of equipment used during the
borrow and construction operations,
(2) location of work, including borrow and construction sites;
(3) size, location, number, and identification of test sanples collected
and results of all tests performed;
(4) a diary of all relevant climatic and working conditions that may
affect construction of the full scale liner;
(5) index of all tests and'lfesults that will be used to compare
the liner constructed in the test fill to the full scale liner; and
(6) a test fill report that compiles all docunentation on the constructs
of the test fill and includes all raw data and test results.
Laboratory hydraulic conductivity tests should be conducted on undisturb*
sanples collected from the soil liner in the test fill. Care should be
taken to avoid conditions that bias test results. Examples of these conditior
include excessive effective confining pressure (Boynton and Daniel, 1985;
Anderson, 1982) and sidewall flow (Daniel et al, 1985). Methods for collectir
undisturbed sanples of soil liners have been suggested by Anderson et al
(1984) and Day (1984). The undisturbed sanples may not provide hydraulic
conductivity values that precisely reflect field values. However, comparison
of values obtained from the test fill and full scale- liners- should provide
an indicator of gross changes in either the materials or procedures used in
construction.
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47
EPA believes that additional testing is warranted to evaluate the hydraulic
conductivity of landfill and surface impoundment sidewalls. Especially in
surface impoundments, the sidewalls ray be the predominant pathway by which
leachate can migrate beyond the liner systems. At this time however, the
Agency is not asrare of a suitable method for evaluating hydraulic conductivity
of the sidewalls other than by construction of a costly scale inpoundment.
There would need to be separate underdrains for the sidewalls and bottom
portions of the liner or it would be difficult to determine how much each
portion was contributing to the total underdrainage. EPA is temporarily
deferring the recommendation for sidewall testing to allow interested parties
to develop economical and effective test methods. Comments are requested on
the following:
(1) Are tests of the hydraulic conductivity of landfill and surface
impoundment sidewalls necessary?
(2) Are there methods available for evaluating the hydraulic conductivity
of sidewalls?
(3) Are there additional methods that should be developed to facilitate
this testing?
In construction of EMLs, consideration should be given to the effects
from humidity in the air. Seaming of EMLs with some solvent cements at
high levels of relative humidity can result in moisture condensation on the
adhesive surface during the seaming process and may result in poor adhesion.
A relative humidity requirement may not be necessary for seaming techniques
that rely on heat to bond the liner sheets, as the heat could prevent moisture
from condensing on warm surfaces of the FML.
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43
III. Construction Quality Assurance
Contents
Page
A. Guidance 47
Objective 47
Design and Construction 47
0 Elements of a CQA plan
B. Discussion 49
A.
Overall Design/ Construction, and Operation Objective
Certain surface impoundment and landfill units and most interim status an
permitted waste piles most have a single liner with a leachate collection
system above the liner for landfills and waste piles. The liner must be desig
constructed, and installed to prevent any migration of wastes out of the unit
during the active live (including closure period). The Leachate collection
system nust be designed, constructed, maintained, and operated to collect and
remove leachate from the landfill or waste pile. To assure that a corrpleted
liner system meets or exceeds all projected design criteria, plans, and
specifications, a construction quality assurance (CQA) program is necessary.
In addition, the regulations for permitted units (§§264.226, 264.253, and
264.303) specifically require liners to be inspected during construction for
uniformity, damage, and imperfect Jons (e.g., holes, cracks, thin spots, or
foreign materials); immediately after construction, EMLs must be inspected to
ensure tight seams and joints, and the absence of tears, punctures, or blister:
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49
As part, of the CQA program for conpacted soil liners, a test fill should
be constructed using the sane rraterial procedures and equipment that will be
used in the full scale facility. The CQA plan to be followed during the full
scale facility construction should be exactly followed during construction of
the test fill.
Design and Construction
(a) The owner/operator should submit and inplement a written construction
quality assurance plan to be used during construction of the leachate collection
system (for landfills and waste piles) and liner. The plan should be used in
monitoring and documenting the quality of materials used and the conditions
and manner of their placement. The plan should be developed, administered,
and documented by a registered professional civil or geotechnical engineer
with experience in hazardous waste disposal facility construction and construction
site inspections. While the specific content of the construction quality
assurance plan will depend on site-specific factors, the following specific
components should be included, at a mininun:
0 Areas of responsibility and lines of authority in executing the CQA
plan;
0 Qualifications of CQA personnel; •
0 Specific construction quality control (CQC) activities, observations,
and tests - preconstruction, construction, and post-construction
testa to verify that materials and equipment will perform to specifications,
and that the performance of the individual parts of the liner system
conform to design specifications. As completed, the individual parts
of the liner installation should t« tested for functional integrity^
For FMLs, joints, seams, and mechanical seals should be checked both
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50
during and after installation. A variety of testing methods can be
used such as:
- hydrostatic
- vacuum
- ultrasonic :
- air jet
- spark testing.
For soil liners, the conpacted soil should be tested to verify that it
has an in-place field hydraulic conductivity of 1X10"7 cm/sec or less.
Testing should include undisturbed samples taken from the compacted soil
layers during contruction of the liner. The collection layer should be
tested to assure the components are functioning as designed.
0 Sampling program design; the frequency and scale of such observations and
tests, acceptance-rejection criteria, corrective measures, and statistical
evaluation.
0 Documentation of CQA should include daily recordkeeping (observation and
test data sheets, problem reporting and corrective measures data sheets),
block evaluation reports for large projects, design engineer acceptance
reports (for errors, inconsistencies, and other problems), and final docum
tation. After completion of the liner system, a final documentation repor
should be prepared. This report should include summaries of all construct.
activities, observations, test data sheets, problem reports and corrective
measures data sheets, deviations from design and material specifications,
and aa-built drawings.
(b) The documentation for the OQA program for the construction of the unit
should be kept en-site in the facility operating record.
&*—Discussion
Construction quality assurance (OQA) during construction of the liner
system is essential to assure, with a reasonable degree of certainty, that
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Dj.
the system meets the design specifications. This involves inspecting and
documenting the quality of materials used and the construction practices
employed in their placement. OQft. serves to detect deviation from the design
caused by error or negligence on the part of the construction contractor,
and to allow for suitable corrective measures before wastes are disposed.
Without proper construction quality assurance, problems with the leachate
collection system, and FML or soil liner due to construction nay not be
discovered until the system fails during operation.
A recent survey of hazardous waste surface inpoundment technology has
found that rigorous quality assurance is necessary to achieve good unit
performance (Ghassemi, et al 1984). Liner failures at several impoundments
were attributed to various factors including "failure to execute proper
quality assurance and control." The success of surveyed facilities that have
performed well is attributed to many factors including "the use of competent
design, construction, and inspection contractors, close scrutiny of all
phases of design, construction,.and QA inspection by the owner/operator,
excellent QA/QC and recordkeeping during all phases of the project, and good
connunications between all parties involved in constructing the units."
Specific problems that can cause failure of the liner system and that
can be avoided with careful construction quality assurance include:
Collection System
* The use of naterials other than those specified in the approved design;
* Foreign objects (e.g., soil) left in drain pipes, which plug or restrict
flow and may not be removable using currently available maintenance
procedures;
* Neglecting to install materials at locations specified in the design;
* Neglecting to follow installation procedures specified in the design;
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52
0 Siltation of drainaye material resultiny from inproper upgradient drair.a
during construction and/or careless construction techniques;
8 Inprcper use of construction equipment causing crushing or misalignment"
of pipes;
0 Inprcper layout of the system, including misalignment of pipe joints
or inproper slopes and elevation of pipes; and
0 Use of unwashed gravel or sand in drain layers.
EMLs Used as the Liner
0 The use of materials other than those specified in the approved design;
0 Inproper preparation of the supporting surface (usually soil subgrade)
to receive the liner;
0 The use of inprcper installation techniques and procedures by the
contractor;
0 The inproper use of construction tools and equipment;
* Inadequate sealing and anchoring of the liner to structures, pipes,
and other penetrations tlirough the liner;
* Installation of the liner during inclement weather; and
0 Inproper repair of defects in the installed liner resulting from
manufacturing processes and installation methods.
Low-Permeability Soil Liner
0 The use of materials other than those specified in the approved design;
0 Inproper conpaction equipment;
* Inadequate conpactive effort;
0 Inproper corrpaction procedures;
9 Inadequate scarification between lifts;
0 Excessive lift thickness;
0 Inadequate liner thickness;
e Excessive field hydraulic conductivity;
0 Inadequate method of water addition;
8 Inadequate time allowed for even distribution of moisture;
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53
0 Iriadequate method used to raintain the optimum moisture content in
the liner between construction of each lift and after conpletion of
the liner; and
c The use of an inadequate quantity of added fine-grained materials
(important with bentonite/soil liners).
The ability of the hazardous waste disposal unit to meet its designed
regulatory performance goals depends on adherence to approved design plans
and specifications during construction. Confidence in the ability of
installed liners to perform properly is attained through a well-developed,
well-implemented, and well-documented CQA program. The program should be
developed by the design engineer, who can focus the emphasis of quality
assurance on those elements of the design that are critical to FML or low-
permeability soil liner performance. Implementation of the OQA program should
include participation by the design engineer in resolving construction or
design problems that rnay be identified during construction. Timely identifi-
cation of such problems during construction allows corrective measures to be
taken before construction is completed and wastes are deposited. Confidence
in the liner is established through:
* Careful documentation of:
- Construction scheduling, conditions, and progress;
- Site inspections;
- Material/equipment testing results and data verification; and
- As-built conditions.
' The owner/operator providing the opportunity for review, inspection,
and approval by appropriate regulatory and permitting agencies.
Each of the elements identified as components of the written construction
"quality assurance plan will be described in detail in all upcoming document
on the subject of construction quality assurance for hazardous waste land
disposal units. The document will address"the components listed below:
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54
0 Low-permeability soil liners;
° Flexible membrane liners (EMLs) or synthetic meniarane liners;
9 Dikes;
' Low-permeability soil caps and cover systems; and
8 Leachate collection systems.
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55
References
Anderson, D.C. (1982), Clay Liner-Hazardous Waste Compatibility. Report to
the U.S. EPA, K.W. Brown and Associates, College Station, Texas. (EPA
Contract * 68-01-6515)
Anderson, D.C., J.O. Sai, and A. Gill (1984), Surface Impoundment Soil
Liners: Permeability and Morphology of a Soil Liner Permeated by Acid and
Field Permeability Testing for Soil Liners. Report to U.S. EPA, K.W.
Brown and Associates, College Station, Texas. (EPA Contract # 68-03-2943)
August, H., R. Tatzky, G. Pastuska, and T. Win (1984), Study of the Permeation
Behavior of Commercial Plastic Sealing Sheets as a Bottom Liner for Dumps
Report No. 103 02 208, Federal Minister of the Interior, Berlin, West Germany.
Barron, R.A. (1977), The Design of Earth Dams. (Chapter 6) In (A.R. Golze,
ed) Handbook of Dam Engineering. Van Nostrand Reinhold Company, N.Y. p.
291-318.
Boutwell, G.P. and V.R. Donald (1982), Compacted Clay Liners for Industrial Waste
Disposal, Presented ASCE National Meeting, Las Vegas, April 26, 1982.
Boynton, S.S. (1983), An Investigation of Selected Factors Affecting the
Hydraulic Conductivity of Compacted Clay. M.S. Thesis, University of
Texas, Geotechnical Engineering Thesis GT83-4, Geotechnical Engineering
Center, Austin, Texas. 79 p.
Boynton, S.S. and D.E. Daniel (1985), Questions Concerning Hydraulic Conductivity
of Compacted Clay. Journal of Geotechnical Engineering, Vol. Ill, No. 4.
Brown, K.W. and D.C. Anderson. (1983), Effects of Organic Solvents on the
Permeability of Clay Soils. United States Enviromental Protection Agency.
Grant No. R806825010. 153 p.
Brown, K.W., J.W. Green, and J.C. Thomas, J.C. (1983), The Influence of Selected
Organic Liquids on the Permeability of Clay Liners. In Proceedings of
the Ninth Annual Research Symposium on Land Disposal oT Hazardous Waste,
(EPA-600/9-83-018). p. 114-125.
Corps of Engineers (1977), Earth-fill and Rock-fill Construction. (Chapter 5)
In Construction Control for Earth and Rock-Fill Dams. U.S. Army Engineer
Manual EM1110-2-1911
Daniel, D»B» (1984), Predicting Hydraulic Conductivity of Clay Liners.
Journal of Geotechnical Engineering, Vol. 110, No. 2 p. 285-300.
Daniel, D.E., D.C. Anderson and S.S. Boynton (1985), Fixed-Wall vs Flexible-Wall
Permeameters. In Hydraulic HarHo>r« In Qni 1 and Hnrkr ACT* STP 874 (In
—Press).
Day, S.R. (1984), A Field Permeability Test for Compacted Clay Liners. M.S.
Thesis/ University of Texas, Austin, Texas 105 p.
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56
Day, S.R., D.E. Daniel, and S.S. Boynton, (1985),"Field Permeability Test
for Clay Liners. Jin Hydraulic Barriers in Soil and Rock, ASTM STP 874
(In Press).
Dunn, R.J. and J.K. Mitchell (1984), Fluid Conductivity Testing of Fine-Grain
Soils. Journal of Geotechnical Engineering, Vol. 110, No. 11, p. 1648-1665
i
Earth Manual. (1984), Bureau of Reclamation, U.S. Department of the Interior.
Government Printing Office, Washington, D.C.
EPA (1982), Test Methods for Evaluating Solid Waste. United States Environme
Protection Agency, Washington, D.C. (SW-846).
EPA (1983), Landfill and Surface Impoundment Performance Evaluation United
States Environmental Protection Agency, Washington, D.C. (SW-869), April 19;
(S/N 055-000-00233-9, $5.00), Superintendent of Documents, U.S. Government
Printing Office, Washington, D.C. 20402, 69 pages.
EPA (1983A), Lining of Waste Impoundment and Disposal Facilities. United Stai
Environmental Protection Agency, Washington, D.C. (SW-870), March 1983.
(S/tt 055-000-66231-2, $11.00), Superintendent of Documents, U.S. Government
Printing Office, Washington, D.C. 20402, 448 pages.
EPA (1984B), Procedures for Modeling Flow Through Clay Liners to Determine
Required Liner Thickness. (Draft Technical Resource Document for Public
Comment) United States Environmental Protection Agency, Washington, D.C.
(EPV530-SW-84-001). 32 p.
EPA (1984A), Soil Properties, Classification, and Hydraulic Conductivity
Testing. United States Environmental Protection Agency, Washington, D.C.
(SW-925). 167 p.
EPA (1983C), Hazardous Waste Land Treatment. United States Environmental
Protection Agency, Washington, D.C. (SW-874).
Geotextile Engineering Manual, Training Manual, Federal Highway Administration
Ghassemi, M., M. Haro, and L. Fargo (1984), Assessment of Hazardous Waste
Surface Impoundment Technology Case Studies and Perspective of Experts.
Report to the U.S. EPA, MEESA, Torrance, CA. (EPA Contract 169-02-3174).
Green, J.W., K.W. Brown, J.D. Thomas (1985), Effective Porosity of Compacted
Clay Soils Permeated with Organic Chemicals. ^n_ Land Disposal of Hazardous
Waste/ Proceedings of the Eleventh Annual Research Synposium, pp. 270-271.
Griffin, R.A. et al. (1984), Migration of Industrial Chemicals and Soil-waste
Interactions at Wilsonville, Illinois. In Proceedings of the Tenth Annual
Research Symposiumon Land Disposai-olHazdtUuus Wasle (CPA COO/9 04—0074-
USEPA Municipal Environmental Research Laboratory, Cincinnati, OH 45268.
Griffin, R.A., N.F. Shrimp, Attenuation of Pollutants in Municipal Landfill
Leachate by Clay Minerals, EPA-600/2-78-157, U.S. EPA, MERL, Cincinnati, OH
{OTIS PB 287-140/AS].
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Griffin, R.A., R.E. Hughes, L.R. Follmer, C.J. Stohr, W.J. Morse, T.M. Johnson,
J.K. Bartz, J.D. Steele, K. Cartwright, M.M. Killey and P.B. DuMontelle
(1984), Migration of Industrial Chemicals and Soil-Waste Interactions at
Wilsonville, Illinois. In; Proceedings of the Tenth Annual Research
Symposium on Land Disposal of Hazardous Waste, (EPA 600/9-84-007).
Herzog, B.L. and W.J. Morse (1984), A Comparison of Laboratory and Field
Determined Values of Hydraulic Conductivity at a Waste Disposal Site. In:
Proceedings of the Seventh Annual Madison Waste Conference, University of
Wisconsin-Extension, Madison, Wisconsin/ pp 30-52.
Horz, R.C. (1984)/ Geotextiles for Drainage and Erosion Control at Hazardous Waste
Landfills. EPA Interagency Agreement No. AD-96-F-1-400-1. U.S. EPA,
Cincinnati, Ohio.
Johnson, Russell and Eric Wood, (1984), Unsaturated Flow Through Clay Liners.
Report to the U.S. EPA, GCA Corporation, Bedford., MA. (EPA Contract
#68-01-6871).
Johnson, Russell and Eric Wood, (1984), Unsaturated Flow Through Clay Liners
(Letter Report). Prepared for the Office of Solid Waste, Washington, D.C.,
OCA Corporation, Bedford, MA. (QCA-TR-85-01-G) 29 p.
Kays, W.B. (1977), Construction of Linings For Reservoirs, Tanks, and Pollution
Control Facilities. John Wiley & Sons, Inc. NY. 379 p.
Koerner, Robert M., and J.P. Welsh (1980), Construction and Geotechnical Engineer!™
Using Synthetic Fabrics. John Wiley and Sons, New York.
Lindsey, W.L. (1979), Chemical Equilibria in Soils. John Wiley and Sons, Inc.,
449 p.
Mitchell, J.K. (1976), Fundamentals of Soil Behavior. John Wiley and Sons,
Inc.-, N.Y. 422p.
Mitchell, J.K., D.R. Hooper, and R.G. Campanella (1965), Permeability of
Compacted Clay. Journal of the Soil Mechanics and Foundations Division,
ASCE, Vol. 91, No. SM4. p. 41-65.
NSF (1983), Standard Number 54, Flexible Membrane Liners. National Sanitation
Foundation, Ann Arbor, Michigan. 69p.
Olson, R.E. and D.C. Daniel (1981), Field and Laboratory Measurement of the
Permeability of Saturated and Partially Saturated Fine-Grained Soils. In_
Permeability and Groundwater Contaminant Transport, ASTM STP 746.
U.S. Environmental Protection Agenc»
Region 5, Library (PL-12J)
77 West Jackson Boulevard, 12tfl Flow
Chicago. It. 60604-3590
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Suggested Reading List
Flexible Membrane Liner Permeation
Haxo, H. E., j. A. Miedema, and N. A. Nelson (1984), Permeability of Polymer,*
Membrane Lining Materials for Waste Management Facilities. In Proceedings
of the Education Symposium on Migration of Gas, Liquids, and~sblids in Elastome
Denver, Colorado. Sponsored by Rubber Division, American Chemical Society,
Oct. 23-26, 1984.
August, H., R. Tatzky, G. Pastuska, and T. Win (1984), Study of the Permeation
Behavior of Commercial Plastic Sealing Sheets as a Bottom Liner for Dumps
Against Leachate, Organic Solvents, and their Aqueous Solutions. Research
Report No. 103 02 208, Federal Minister of the Interior, Berlin, West Germany.
Mitchell, J. K., D. R. Hooper, and R. G. Campanella, (1965), Permeability of
Compacted Clay. Journal of Soil Mechanics Foundation Division, ASCE, 91 (SM4):
41-65.
Statistical earthwork control
Hinterkorn, H., and H. Y. Fang. Foundation Engineering Handbook, Van-Nostrand-
Reinhold, Publishers (1975), See Chapter 7 by Jack W. Hilf, section 7.4:
Control of Compaction.
Lee, I. K., W. Mute, and 0. G. Ingles. Geotechnical Engineering, Pitman Publi:
(1983), See Chapter 2, Soil Variability; and Chapter 9, Soil Treatment:
Quality Assurance. (Good general introduction to the use of statistics).
Representative samples
U.S. Environmental Protection Agency. Test Methods for the Evaluation of
Solid Waste. SW-846, Washington, D.C., July 1982 Second Edition.
U.S. Environmental Protection Agency. Draft Solid Waste Leaching Procedure
Manual. Washington, D.C., 1983.
Graded granular filters
U.S. Environmental Protection Agency. Guide to the RCRA Land Disposal Permit
Writers' Training Program, Volume 1, Sept. 1984, Chapter 3, p. 3-38 to 3-41.
Synthetic fabric filters
U.S. Environmental Protection Agency. Guide to the RORA Land Disposal Permit
Writ-ptrs's Training Program, Volume 1, Sept., 1984, Chapter 3, p. 3-44 to 3-46.
U.S. Federal Highway Administration. Geotextile Engineering Manual.
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