VOLUME I
DATA BASE DEVELOPMENT: PERSPECTIVES OF INDUSTRY EXPERTS,
STATE REGULATORS, AND OWNERS AND OPERATORS
By:
M. Ghaseomi (Program Manager and Technical Director),
M. Haro, J. Metzgar, M. Powers, S. Quintivan, L. Scinto and H. White
EPA Contract No. 68-02-3174
Work Assttjmrant No. 109
MAY, 1983
EPA Project Officers:
Otte C-.rlton Wiles
Office of Solid Waste Municipal flnviro.imenUl Research Laboratory
Washington, DC 20460 Cincinnati, OH 46236
TRW
Erwrgy and EnrwonmBnta! Division
23900 Hawthorne Bnul^ard, Suite 200
Torrancfl. CA 90505
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ABSTRACT
This effort Is part of a broader effort to collect ‘ real wor1d and
up-to-date information for use by EPA In its regulatory reform review of the
sections of the July 1982 InterIm final land disposal regulations pertaining
to liners for hazardous waste management facilities. Interviews were con-
ducted with some 40 Individuals/organIzations representing a spectrum of view-
points/Interests and having expertise In various aspects of selection, design,
manufacturing, fabrication, and installation of liners (primarily flexible
mentrane liner or FML and clay liner). This compendium presents the opinions
expressed by those Interviewed on topics which include: (1) clay and FML
systems used In hazardous waste land disposal application; (2) factors/problems
associated with manufacturing, fabrication, Installation, etc., wMch Impact
liner performance 1 and recoumended changes to mitigate problems; (3) research
and development needs for addressing problems; and (4) role of regulations and
regulatory needs. The Information collected during the interviews Is primarily
the opinions of those interviewed and is reported here without any change or
an attempt by the authors or EPA to interpret or analyze the opinions expressed
or to present opposing views.
The opinions collected Indicate a reasonable consensus on the following
points:
• The technology and know-how currently exist to produce installed
liners that will not fall. Such technology and know-how, however, are
not necessarily always employed in actual practice primarily due to:
(1) Inadequate familiarity of many users and permitting agencies with
potential problems and mitigation measures; (2) failure of the user
to consider factors other than cost In selecting contractors; (3) lack
of adequate coninunicatlon among all parties involved; and (4) absence
of an effective quality assurance/quality control program at all steps
leading to the development of a completed installation.
• Because of the Involvement of fewer steps/parties and the more de-
veloped state-of-the—art for clay liners, construction of such liners
presents fewer and more manageable problems. There Is a general
ii
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agreement, however, that a clay-FML combination system can offer the
most protection.
• Ptst liner failures can be traced to Inadequate designs. Next to
design, installation (especially field seaming of FIlL sheets) Is the
most critical factor in developing an adequate installation.
• There Is a lack of long-term engineering data on the performance of
both clay and FML In field Installations, and there exists a need for
documentation and analysis of design and installation practices which
have led to failures and successes of actual Installations.
iii
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ii
vi
vii
1—1
• . 2—1
• . 3—1
3-1
3-3
• . . 3-3
• . . 3-5
• , . 3-8
• • . 3-13
3-17
3-17
3-19
3-19
3-21
3-23
3-26
3-27
3-27
3-28
3-29
3-29
3-30
3-31
3-31
3-31
3-33
3-33
CONTENTS
Abstract
Tables
Acknowledgements
1. Background, Objective, and Scope
2. Indlviduals/Organizations Interviewed and Data Acquisition
Methodology
3. Overview of the Collected Opinions
3.1 OpInions on Clay and FIlL Systems Used In Hazardous Waste
Land Disposal Application
3.2 Factors Affecting FML Performance and Measures for
Mitigating Problems
3.2.1 General Considerations
3.2.2 Design Considerations
3.2.3 Installation (Seaming Problems)
3.2.4 Raw Materials and Manufacturing Considerations.
3.2.5 FabrIcation and Transportation
3.2.6 Research and Development Needs
3.3 Factors Affecting Clay Liner Performance and Measures for
Mitigating Problems
3.3.1 General Considerations
3.3.2 DesIgn Considerations
3.3.3 InstallatIon Considerations
3.3.4 Research and Development Needs
3.4 Performance Considerations and Problem Mitigation Measures
for Other Liner Types
3.4.1 General Considerations (Comparison with FML and
Clay)
3.4.2 Asphaltic Concrete
3.4.3 Asphaltlc Rubber
3.4.4 Asphaltic Emulsion Spray-On
3.4.5 Bentonlte-Soll Admixture
3.4.6 Research and Development Needs
3.5 Perspectives on Regulations
3.5.1 Limitations of the Interim Final Regulations.
3.5.2 QA/QC Requirements
3.5.3 Miscellaneous
lv
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CONTENTS (Continued)
4. Interview Reports 4-1
4.1 IntervIew Reports With Suppliers, Manufacturers,
Fabricators. Designers, and Installers of FML, Clay,
and Other Liners . . 4-2
4.2 Interview Reports With Owners/Operators of Hazardous
Waste Management Facilities . . 4-132
4.3 Interview Reports With State Regulatory Agencies . . . 4-161
4.4 Interview Reports With Researchers in Academic and
Research Organizations 4-201
4.5 IntervIew Reports With Trade/Professional and Standards
Setting Organizations 4-253
V
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TAB L ES
No.
1. Typical Interview Date Confirmation Letter 2-2
2. Suppliers, Manufacturers, Fabricators, Designers, and
Installers of FML, Clay, and Other Liners Interviewed 2-3
3. Owners/Operators of Hazardous Waste Management Facilities
Interviewed 2-5
4. State Regulatory Agencies Interviewed 2-6
5. Researchers in Academic and Research Organizations Interviewed. . 2-7
6. Trade/Professional and Standards Setting Organizations
Interviewed 2-8
7. TypIcal Letter Requesting Review Coninents on Draft Interview
Reports 2-10
vi
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ACKNOWLEDGEMENTS
This effort has been carried out under a contract with U.S. EPA as a
joint program of the Land Disposal Branch of EPA’s Office of Solid Waste,
Washington, DC, and the Solid and Hazardous Waste Research Division of EPA’S
Municipal Environmental Research Laboratory, Cincinnati, OH. Gratitude is
expressed to the EPA Project Officers, Messrs. Alessi Otte and Carlton Wiles,
and to other technical staff of the two EPA offices, in particular to Messrs.
Robert Tonetti, James Bachmaler, Glen Galen, Robert Landreth, Michael Rouller,
and Doug Aim on, for their support and guidance during the course of the
effort.
This compendium presents the views of a sampling of liner material
suppliers, manufacturers, fabricators, designers, and Installers; technical
experts and researchers at academic and research institutions; trade associa-
tions; technical staff at state regulatory agencies; and owners and operators
of hazardous waste nanagement facilities. TRW wishes to express Its deepest
gratitude to the individuals/organizations listed In Tables 2 through 6 who
made this project feasible by fully cooperating with the study via granting
of interviews and reviewing the draft interview reports.
Special thanks are due to Mrs. Monique Tholke for her Invaluable secre-
tarial support to the project.
vii
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1. BACKGROUND, OBJECTIVE, AND SCOPE
The Environmental Protection Agency’s Office of Solid Waste is currently
engaged In a review of the Part 264 land disposal regulations (promulgated In
July 1982 as Interim Final Regulations) to determine If there are areas where
regulatory reform would be appropriate. One of the areas which Is being re-
viewed relates to the requirement for liners (and covers) for new land dis-
posal facilities which stipulates prevention of the migration of waste during
the active life of a facility and minimization of the migration during the
post-closure care period. The liner requirement review effort involves prima-
rily a detailed examination of the efficacy of flexible membrane liners (FML),
clay and other types of liners (and caps) used in various locations to minimize
groundwater contamination.
The present effort, which has been carried out under a work assignment
contract for EPA’s Office of Solid Waste, has had as its objective the develop-
ment of a technical data base for the evaluation of the ability of current
manufacturing, fabrication, design, construction, and installation practices
to produce clay, FML, and other types of liners meeting the performance stan-
dards stipulated In the interim regulations. More specifically, the data base
is to be used to answer the following:
• Can liners be Installed near design conditions so that they will not
fail?
• Are such liners actually installed near design conditions?
To ensure the incorporation of “real world” data and up-to-date informa-
tion in the data base for liner capability evaluation, the data base develop-
ment effort has emphasized data acquisition from technical experts and indi-
viduals/organizations engaged In actual manufacturing, fabrication, design
and Installation of liners, and in operation and regulation of hazardous waste
management facilities. To this end, face-to-face discussions have been con-
ducted with a relatively large sample of indivIduals/organIzations representing
1—1
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a spectrum of viewpoints/interests and having expertise in various aspects of
liner selection, design, etc. This report presents the opinions of mdlvi-
duals/organizations interviewed on topics such as:
• Use of clay and FML systems In hazardous waste land disposal
application.
• Factors/problems associated with manufacturing, fabrication, etc.,
which Impact liner performance, and recomended changes to mitigate
problems.
• Research and development needs for addressing problem areas.
• Role of regulations and regulatory needs.
Many of the individuals who were interviewed saw a great need for sys-
tematic and continual transfer of information on the latest developments in
liner technologies, design advances, and R&D needs to the user comunIty
(designers, Installers, permitting agencies, owners/operators of disposal
sites, researchers, etc.). To this end, this compendium can serve as an
important step toward the goal of promoting exchange of opinions among
agencies/organizations with Interest in various aspects of hazardous waste
management. As a result of the preparation of this compendium, important
contacts have been developed and a dialogue has been established with key
experts and various interested parties. Steps should thus be taken to main-
tain and expand these contacts and dialogue so that this compendium can be
periodically updated in the future.
This compendium is organized Into four major sections: Section 1 (thIs
section) revIews the background for and the intended use(s) of this document.
Section 2 describes the methodology for data acquisition and identifies
Individuals/organizations providing input to the compendium. Section 3 Is an
overview of the information collected during Interviews. Reports on Indivi-
dual Interviews are presented in Section 4.
It should be noted that the perspectives expressed In this compendium
constitute merely one input to an analysis which draws upon a much broader
data base, including results of many recent EPA-sponsored studies and other
published literature which might contradict (or support) certain opinions
expressed by the interviewees. In line with this consideration and other
1—2
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possible uses of the document, the opinions collected during the Interviews
are presented in this compendium without any change or discussion, and hence,
no attempt has been made to analyze views expressed or to present opposing
viewpoints on certain controversial assertions. Some technical analysis of a
number of points raised relating to liner Installation, compatibility, and
failure mechanisms can be found In Volume II of this document and in the final
reports being prepared for EPA by Research Triangle Institute (Research
Triangle Park, NC) and Arthur D. Little, Inc. (Cambridge, MA) In connection
with two companion liner studies.
1-3
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2. INDIVIDUALS/ORGANIZATIONS INTERVIEWED
AND DATA ACQUISITION METHODOLOGY
The initial identification of potential interviewees was via review of
the literature arid discussions with the EPA Project Officers and the technical
staff at EPA’s Solid and Hazardous Waste Research Division in Cincinnati, OH.
The potential Interviewees were then contacted (“screened”) by telephone to
gauge their interest in the study and the type and relative value of their
potential inputs. Mutually agreeable dates for the Interviews were then set
and subsequently confirmed In formal letters. With each letter a copy of the
“work plan”, which provided a more elaborate description of the study and its
objectives, was enclosed. A copy of the typical letter Is reproduced as
Table 1.
The individuals/organizations interviewed are listed In Tables 2 through
6, broadly grouped into the following categories:
a Suppliers, manufacturers, fabricators, designers, and Installers of
FML, clay, and other liners.
• Owners/operators of hazardous waste management facilities.
• State regulatory agencies.
• Researchers in academic and research organizations.
• Trade/professional associations and standards setting organizations.
The categorization in the tables is for presentation purposes only since,
in some cases, an organization may be involved in or represent more than one
category. Within each table, the interviewees are listed in chronological
order of the interviews. Overall, a total of 39 IntervIews were conducted.
Except for three telephone discussions, the Interviews involved face-to-face
discussions which took place in a very informal atmosphere. In most cases 1
more than one Individual represented the participating organization.
2-1
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TABLE 1. TYPICAL INTERVIEW DATE CONFIRMATION LETTER
TRW
T300-MG .83-008
19 Januory 1983
Mr. Gary Sherlaw
National Sanitation Foundation
3475 Plymouth koad
Ann Arbor 1 M I 48105
Dear Mr. Sherlaw:
This is with reference to our telephone conversation of today, confirmin’j
our meetiu.g scheduled for 9 00 AM, 243 January 1983, ii , your office n Ann ArLaur.
Our purpose is to obtain technical information and your perspectives on various
aspects of the manufacture, fabrication 1 and installation of liners. This In-
formation will be used In an EPA study, the work plan of which is enclosed for
your review.
As mentioned to you in our conversation and described in more detail in
the enclosed work plan, it n the objective of the subject study to develop the
technical data base for use by EPA in its review of the Part 264 land disposal
regulations promulgated July 26, 1982, to determine if there are areas where
rtgulatory reform would be appropriate. The review would particularly address
the requirements for liners and covers for new land disposal units. Under the
new regulations, the migration of wastes must be prevented during the active
life of a unit, and minimized during the post-closure care period.
The subject study will seek to develop the data base needed for the evalua-
tion of the ability of current manufacturing, construction, and installation
practices to produce clay, synthetic u thrane, and other types of liners to IT,eet
the above performance standards. To ensure an objective evaluation bised on
TM real world data and sound technical rationale, in developing the daL base we
are supplementing the information in the published literature with updated data
acquired through discussions with a spectrwi of individuals/organications repre-
senting different viewpoints/interests and having expertise on various aspects
of liner design, construction, and installation, it is to this end that we are
soliciting your participation in and input to our data base development effort.
I trust that you will find the enclosed work plan of help to you in a;-
plaining the nature and objective of our study, and I look forward to meeting
with you.
Sincerely, -
Masood’t sstmi, Ph.D., P.E.
Senior Project Engineer
Mall Station: k4/ll42
MG/mt
Enclosure
C: A. Ofle (EPA/OSW; Washington, DC}
C. Wiles (EPA/Mit; Cincinnati, OH)
•iv.a S ‘a D’vaa Saa ravgt wgar *eo.ot rmvsc’ , pwa Mat IUCMJO aao,. cat ,#o*n’& .ni • n ra is s,e
2-2
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TABLE 2. SUPPLIERS, MANUFACTURERS, FABRICATORS, DESIGNERS, AND INSTALLERS OF
FML, CLAY, AND OThER LINERS INTERVIEWED
Coqany and Address Intervie e(s) and
Date
of Background/Expertise Interview
Telephone
er
Inter
view
k.
Schlegel Lining Technology, Inc. James Price, 14 Deconber 1982 Manufacturer and installer of A-I
200 S. Trade Center Parkway brris Jett, high density polyethylene
P. 0. Box 7730 Robert Clarke, FPt.
The odlands, TX 77380 Jan Braun
(713) 350-1813
Ste-Flex Corporation Louis Peloquln 14 December 1982 Pt installer. A-2
4917 Mew Ramsey Court (408) 224-0604
San Jose, CA 95136
Burke Rubber Coa any 0. Kutnewsky 16 December 1982 FMI. manufacturer and fabrica- A-3
2250 South 10th Street Ralph Woodley tor.
San Jose, CA 95112 (408) 297-3500
Gundle Lining Systems. Inc. Richard ScPldt 17 December 1982 FMI. manufacturer. A-4
1340 East Richey Road (713) 443-8564
Houston, TX 77073
Watersaver Co any, Inc. Bill Slifer 17 December 1982 P11 fabricator. A-5
5870 F. 56th Avenue (303) 623-4111
P. 0. Box 16465
Denver. CO 80216
(.1. DePont de Neoours A Co. Gerald FIsher 18 January 1983 Supplier of raw elastociers for A-6
10 S. 224 Terry Trail (312) 485-6881 31 January 1983 Pt.
Hinsdale, II 60521
H Putter n & Co. Jack Ptreland 24 January 1983 Fit fabricator. A-7
2221 West 43rd Street (312) 927-4121
Chicago, II 60609
knerican Colloid Coe any Christopher Jepsen 26 January 1983 Supplier of bentonite clay; A-8
5100 Suffield Court Robert Massini markets bentonite admixture
Skokie II 60077 (312) 966-5720 lIner.
(Continued)
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TABLE 2. (Continued)
Cot any and Address Interviewee(s) arid Date of Background/Expertise Interv iew
Telephone Number Interview No.
Woodward-Clyde Consultants Jean-Pierre Giroud 27 January 1983 Dr Giroud is a leading ex- A-9
11. East Adams (312) 939-1000 pert on Fi n, design.
Chicago. IL 60603
Roy F Weston knir Netry 31 January 1983 Liner design experience. A-l U
Weston Way (215) 692-3030
Westchester, PA 19380
Slurry Systems Frank Zlainal 2 February 1983 ( signer, constructor, and A-li
7100 Industrial Avenue (219) 949-0561 installer of bentonite liner
Gary, I II 46406 and asphalt nision slurry
walls and spray—on liners.
B.F Goodrich Richard Ward 4 February 1983 Ibtenal supplier, manufactu- A-l2
P. 0. Box 657 (614) 373-6611 u-er, fabricator, and installer
a flarietta, OH 45750 of
The Pantasote Conçany of Larry Karip 6 February 1933 FM manufacturer. A-l3
New York, Inc * (201) 277-8500
26 Jefferson Street
Passaic, NJ 07055
Gulf Seals William Way 7 February 1983 FM installer. A- 14
601 Jefferson, Suite 558 Ralph Crst,liss
Houston, IX 77002 (713) 759-0861
Arizona Refining Co William Naunlin 8 February 1983 rwfacturer and installer of A- iS
P 0 Box 1458 Elizabeth Wilkes asphaltic rubber liner.
Phoenix, AZ 85001 William Ham
(800) 528-5305
‘As of 25 April 1983, no ccsrmients have been received on the draft interview reports sutmitted to
these c ipanles for review.
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TABLE 3. OWNERS/OPERATORS OF HAZARDOUS WASTE MANAGEMENT FACILITIES INTERVIEWED
Company/Organization
and Address
Interviewee(s) and
Telephone Number
Date of
Interview
Interview
No.
CECOS International, Inc. Frank Nero 14 December 1982 B-i
2321 Kerinore Avenue Robert Stadelmaier
Kenmore, NY 14217 Kenneth Malinowski
Peter Tarnawskyj
Ernest Gedeon
Anne Burke
(716) 873-4200
Gulf Coast Waste Disposal Authority Robert Dyer 15 December 1982 B-2
P. 0. Box 1026 (713) 935-4783
La Marque, TX 77568
Browning-Ferris Industries Robert Johnson 17 December 1982 8-3
14701 St. Marie’s, P. 0. Box 3151 Jerry Duggan
Houston, TX 77001 (713) 870-7913
Waste Management, Inc.* John Rohr 27 January 1983 B-4
3003 Butterfield Road Steven Menoff
Oakbrook, IL 60521 Don Waligreen
(312) 654-8800
Lanchester Corporatfon* Morris Holman, Jr. 1 February 1983 B-5
P. 0. Box 490 (717) 354-4351
Honeybrook, PA 19344
Monsanto Polymer Product Co. Jerry McGuire 2 February 1983 8-6
800 North Lindberg (314) 694-5262
St. Louis, MO 63166
*As of 25 April 1983, no coments have been received on the draft interview reports submitted to
these companies for review.
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TABLE 4. STATE REGULATORY AGENCIES INTERVIEWED
Agency and Address Intervie e(s) end
Telephone er
Date of Cou nts Interview
Intervi No.
N Y State Dept. of (nviron. enta1 Conservation
600 DeLaware Street
Buffalo. NY 14202
PA Dept. of Env1ron nta1 Resources
Bureau of Solid Waste Management
200 Pine Street
W11l1a. ort, PA 17701
and
tycoming County Planning Coari1s Ion
48 V. Third Street
Wl)liag ,ort. PA 17701
hark Hans
(716) 847-4585
Richard I Sittle
(717) 327—3653
and
Jerry S. Walls
(717) 327-2230
13 Dec er 1982
15 Dece er 1982
Agency has peraitted and
inspected a ni *r of .ajor
lined facilities.
lycoming County also owns/
operates a landfill with
nt.
C-2
PA Dept. of Env1rot ntal Resources
Bureau of Solid Waste hianagement
1875 New Hope Street
Norristown, PA 19401
Dennis C Orenshaw
(215) 631-2420
16 Dece er 1982
The Norristown Region has
jurisdiction over several
landfills using different
liner types.
C-3
PA Dept. of Enviror enta1 Resources
Bureau of Water Quality Management
100 Forbes Ave.; Koss an Bldg.. Poor 600
Pittsburgh, PA 15222
Plichael Hospodar
Andrew kondis
Scott McDougall
(412) 565-5091
17 Dec er 1982
Department has jurisdiction
over several clay-lined
landfil Is.
C-4
NJ Dept. of Env1ror enta1 Protection
- Division of Water Resources
1474 Prospect Street, CN029
Trenton, P 13 08625
- Solid Waste Adoinistration
1474 Prospect Street, C 1t029
Trenton, NJ 08625
- Bureau of Hazardous Waste
32 E. Hanover Street, CN027
Trenton, NJ 08625
Merry rr1s
David Kaplan
William Brown
(609) 292-0424
John Castner
(609) 292-7744
Ernest K ih1weIn
(609) 984-4061
20 Dece er 1982
Department has jurisdiction
over a large n er of clay-
and Itt-lined landfills.
C-5
P ) Dept. of Health and l ntal Hygiene
Office of Envlrorriental Programs
201 V. Preston Street
Baltiemre, J 21201
Robert H. Byer
Reid 3. Rosnlck
(301) 383-5736
21 Dece er 1982
Clay-lined landfills are
co n in state.
WI Dept. of Natural Resources
Bureau of Solid Waste Management
101 S Webster Street, GEF-ll, Box 7921
Madison, WI 53707
Peter kmet
(608) 266-8804
14 January 1983
Department has strong pre-
ference for clay Over F*.
C- i
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TABLE 5. RESEARCHERS IN ACADEMIC AND RESEARCH ORGANIZATIONS INTERVIEWED
Organization Interviewee(s) and
Date
of Background/Expertise Interview
Telephone P er
Interview
Iso.
Southwest Research Institute David Shultz 13 Deceiiiber 1982 Problems of liner installa- 0-1
6220 Culebra Road (512) 684-5111 tion, testing, and performance.
San Antonio, TX 78284
University of Texas David Daniel 13 Deceether 1982 Leakage through cor acted clay 0—2
ECJ 6.2 (512) 471-1555 liners; laboratory vs. field
Austin, IX 78712 per abil1t1e s.
Texas AYI University kirk Brown 14 Decen er 1982 Waste i. act or clay perema- 0-3
Soil and Crop Sciences Dept. (713) 845-5286 b llity.
College Station, IX 77843
Matrecon, Inc. Henr Kaxo 15 December 1982 Coriatlbility of waste with FMI. 0—4
2811 Adelime (415) 451-2757 terials; developed lechnical
Oakland, CA 94623 Resource Dectaients on Liners
for EPA.
Denver Research Institute William Culbertson 16 Decen er 1982 Developeent of liner amterial 0—5
University of Denver Charles Habenlcht from spent shale.
Denver, C D 80008 (303) 753-2911
U.S. Ar ’ Corps of Engineers Michael Kelley 16 Deceether 1982 Research on liners and covers D-6
Waterways Experiment Station (601) 634-3378 for waste disposal sites.
Geotechnical Laboratory Patrick Tucker
Vlcksburg, 39180 Paul Miller
CoHn Aneny
George Regan
Phil Malone
Robert Larson
Richard Lutton
William P¼irphy
Gordon Carr
U.S. Bureau of Reclamation Bernard Jones 16 Decether 1982 StudIes of coç acted earth, 0-7
P. 0. Box 25007 Ron Forbel asphalt, and Pt as liner in
O 1520, Denver Federal Bldg. Chester Jones water projects.
Denver, CO 80225 (303) 234-7044 -
Illinois State Geological Survey t keros Cartwr lght 25 January 1983 Research on clay permeability. 0-8
The Natural Resources Building (217) 333-5113
615 E. Peabody Drive
Chauialgn, II 61820
As of 25 Ap i -I l 1983. no c nts have been received on the draft Interview r p rt submitted for review
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TABLE 6. TRADE/PROFESSIONAL AND STANDARDS SETTING ORGANIZATIONS INTERVIEWED
Organization
and Address
Interviewee(s) and
Telephone Number
Date of
Interview
Background!
Expertise
Interview
No.
American Water Works Association John Capito 15 December 1982 Developed manual E-l
6666 W. Quincy Avenue George Craft on FML in potable
Denver, CO 80235 (303) 794-7711 water application;
standards under
development.
Electric Power Research Institute Dean Golden 17 December 1982 Studies in liner E-2
P. 0. Box 10412 (415) 855-2516 evaluation.
3412 HilIview Avenue
Palo Alto, CA 94303
National Sanitation Foundation Gary Sherlaw 28 January 1982 Developing standards E-3
P. 0. Box 1468 (313) 769-8010 for FML.
3475 Plymouth Road
Ann Arbor, MI 48105
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Following each interview, an Interview sun nary report highlighting the
key and relevant points of the discussion was drafted, based on notes taken
during the interview. The draft interview sun ary report was then forwarded
to the Interviewee for review to assure accuracy and completeness, and to
provide the interviewee with an opportunity to expand or supply additional
lnformatlon/clariflcation on various Issues discussed. To meet the very
stringent project schedule, the draft Interview reports were mailed via an
overnight coninercial delivery service and the interviewees were requested to
submit their coninents by a specified date (usually about two weeks). It was
stated in the transmittal letter that If no coninents were received before the
indicated date, it would be assumed that the draft report is correct and meets
the approval of the Interviewee. Since no response had been received by the
requested dates from about 34 percent of the interviewees to whom the draft
Interview reports had been sent for review, It was assumed that certain of the
non-respondents may have found it very difficult to comply with our quick
turn-around review request. Accordingly, while the first draft of this com-
pendium was under review at EPA, all non-respondents were recontacted and
given additional time to submit corrinents (If any). As of 25 AprIl 1983, com-
ments on or approvals of the as-submitted drafts have been received on 34 of
the 39 Interview reports (an 87 percent response). The changes suggested by
the Interviewees were generally minor and were incorporated in the final
interview reports which are presented in Section 4. A typical letter request-
Ing review of the draft Interview report from a group of Interviewees is
reproduced as Table 7.
2-9
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TABLE 7. TYPICAL LETTER REQUESTING REVIEW COMMENTS
ON DRAFT INTERVIEW REPORTS
ENERGY AND ENVIRONMENTAL DIvISIO i , 20 January 1983 s_a
DIlL SPACE PARK R4/l 142 T300-H6-83-009
RLOOJWO BEACH. CA 90278
Ta
Distribution
ties Hasoud Ghassemi
21 3-535-6219
cc
i t .m
Request for Review of the Draft
68-02-3174, Work Assignment No.
and Installing Cover and Bottom
Interview Swm ary Reports (PA Contract No.
109. Assessmeni of technology for Constructing
Liner .ystems for Hazardous West. Facilities”.
Enclosed Is a “trip reporr which st ar1zes the highlights of the dIicu-
sions which our representative(s) recently had with you for the purpose of
acquiring first hand/ ”real world” technical data for use In the subject assign-
ment for (PA. The report is based on notes taken during the interview ” and
does not contain our analysis of the various topics discussed which we plan to
carry out In connection with the preparation of the final report for the pro-
ject. The trip report is being forwarded to you for review to assure accuracy
and completeness, and to provide you with an opportunity to expand or supply
additional inforsatlon/clarification on the various itsues discussed. Where
applicable, we would appreciate receiving any quantitative engineering and
technical data (“facts and figures”) which you might have since identified to
support some of the statements and assertions which appear somewhat qualitative.
Until we receive your review cosnents, we will continue to treat the •nclo .d
report as preliminary draft and subject to change. To meet our very stringent
project schedule, we would very much like to receive your review coements on the
report no later than February 4, 1983. Unless we hear train you by that date.
we will ass that the material meets with your approval.
On behalf of the TRW project staff and EPA. I went to thank you for your
time and courtesy. The incorporation of the Informetion that you have provided
us in the data base for our study will significantly i rove the qualit ’of the
data base which will be used by EPA in its regulatory refers analysis effort.
Distribution :
Robert Byer. M D Department of Health and Mental Hygiene
John Capito. American Water Works Association
John Caitner, NJ Dept. of Environmental Protection, Solid Waste Mm.
William Culbertson, Denver Research Institute
Henry tiaxo. Matrecon, Inc.
Michael Hospodar, PA Dept. of Environmental Resources, Wetar Quality M t.
Robert Johnson, Brs ing-Ferris Industries
Capt Michael e11ey. IJSAE Waterways Experiment Station
Peter Kmet. WI Department of Natural Resources
Erne .t Kuhlwein, II .) Dept. of Environmental Protection. Hazardous Waste
0. Kutnewiky • Burke Rubber Company
Harry P rr1s, NJ Dept. of Environmental Protection. Water Resources
Dennis Orenshaw, PA Dept. of Environmental Resources. Solid Waste M t.
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3. OVERVIEW OF THE COLLECTED OPINIONS
This section of the report, which is based on the Individual interview
reports presented In Section 4, is an overview of the opinions collected from
technical experts 1 Industry representatives, and state regulatory agencies on
the relative effectiveness of clay and FML, factors affecting liner performance,
research and development needs, and regulatory concerns/needs. This overview
is primarily Intended to provide Insight as to the type and significance of
the collected perspectives and is, by no means, a summary of all the material
contained in the interview reports for which separate individual summaries are
also included in Section 4. This overview also does not Include many of the
general Information items (e.g., descriptions of various seaming methods) which
are contained In the Interview reports and for which considerable data are also
available in the open literature.
It should be emphasized that the material presented here In this section
and In the Interview summary reports contained In Section 4 represents the
opinions of the individuals Interviewed. As would be expected In any survey
of a diverse group of Individuals representing a range of Interests, there are
some conflicts in the opinions expressed. These opinions are presented here
without any change or discussion and no attempts have been made by the authors
or EPA to analyze the views expressed or to present opposing viewpoints. Some
technical analysis of a number of points raised relating to liner Installation,
compatibility, and failure mechanisms can be found in Volume II of this docu-
ment and in the final reports being prepared for EPA by Research Triangle
Institute tResearch Triangle Park, NC) and by Arthur 0. Little, Inc. (Cambridge,
MA) in connection with two companion liner studies.
3.1 OPINIONS ON CLAY AND FM!. SYSTEMS USED IN HAZARDOUS WASTE LAND DISPOSAL
APPLICATION
Proper and objective assessment of the relative merits and demerits of FM!.
and clay in hazardous waste disposal application is hindered by a fundamental
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lack of long-term performance data (successes and failures) on engineered
sites using either type of liner. While there appears to be plenty of state-
ments and assertions as to the actual or expected liner performance, such
statements and assertions are primarily opinions (often motivated by self-
interests) and are not supported by technical data. Because of the difficulty
of assessing liner performance (e.g., seam Integrity for FMLs) under actual
use conditions, liner failures which have been documented generally represent
cases of catastrophic failures and not failures which would ordinarily go un-
detected with the presently available monitoring systems (e.g., cases of slow
leaks). There also appears to be a lack of agreement as to what constitutes a
failure. According to some designers, a leaking liner Is not a failure per se
since “all liners leak to a certain extent”; a leakage would be considered a
failure if it exceeds the rate stipulated in the design.
In general, people in the FML industry are of the opinion that if FML is
properly selected, manufactured, fabricated, designed, and installed, it should
outperform clay in the long run. Owners and operators of hazardous waste
management facilities who are the actual users of liners and who would have
first-line liability responsibility for their performance, as well as state
regulatory agencies who issue operating permits for such facilities, generally
do not argue the point that FilL can be installed to perform satisfactorily, but
Insist that the present practices of manufacturing, design, installation, etc.,
are largely inadequate and cannot be relied upon to consistently produce
quality installation. They argue that there are simply too many things which
can go wrong with FM!.. In general, less objection is expressed for the use of
F L. as caps than as bottom liners because of the greater accessibility of
caps for repair, absence of contact with waste and leachate, and the superior
ability of certain FMLs to absorb subsidence under certain conditions.
The manufacturers, fabricators, and Installers of FM!. who were interviewed
generally consider their own operation of very high standards and blame the
“other guys” for heretofore incidences of bad performance which have generated
some of the current negative Image for FML. In defending FML, they point to
some of the shortcomings of clay, including reported increases in permeability
upon prolonged contacts with concentrated solvent wastes and the difficulty of
predicting the performance of the installed liner based on laboratory permea-
bility tests.
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Those Interviewees expressing a strong preference for clay over FML admit
to the fact that the Installation of clay liners also presents opportunities
for mistakes and poor quality work. They, however, consider that the problems
with clay Installation are fewer and more manageable than those for FML. Their
preference for the use of clay also appear to stem from a presumed greater body
of knowledge and experience which currently exists for clay (largely as the
result of extensive design and construction experience with clay structures
such as dams and entankments). The clay proponents cite published literature
which indicates deterioration of the physical properties of certain FMLs when
exposed to municipal waste leachate and a range of other chemicals. The abil-
Ity of clay to attenuate pollutant movement Is considered a very desirable
safety factor and, hence, a definite advantage of clay over Fit. Indeed, some
researchers believe that the landfill liner should be capable of absorbing all
the leachate which is generated In a landfill, and that the removal of leachate
which necessitates perpetual care connotates waste storage and not disposal.
Because of a lack of trust in FML which is In some cases reinforced by bad
experience with a company 1 s own facilities lined with FML, owners and operators
of major coninerclal hazardous waste management facilities prefer the use of
clay-Fit combination or clay over Ff11. alone. The concern for safe operation
and avoidance of potential liability is reflected In the apparently significant
overdesign which Is typical of many such facilities. Thus, the liner system
at one facility consists of 10 feet of compacted clay, topped by an HDPE liner
which Is, In turn, covered by 2-foot thick clay. Certain state regulatory
agencies (most notably, Wisconsin Department of Natural Resources) also have a
strong preference for clay over FML.
Generally, considerably less information is available on the characteris-
tics and performance of admixes and spray-on liners than on FML and clay. Some
of the information obtained from different sources on the performance of
specially-treated bentonite clay was also contradictory (e.g., from the stand-
point of compatibility with leachate).
3.2 FACTORS AFFECTING Ff11 PERFORMANCE AND MEASURES FOR MITIGATING PROBLEMS
3.2.1 General Considerations
Because a relatively large number of steps and parties are Involved in
producing the final product (i.e., an installed FML), a range of problems
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present themselves during the sequence of raw material preparation, manufac-
turing, fabrication, transportation, design, site preparation, and field In-
stallation. Although certain steps (e.g., design and field Installation) are
considered more critical than others to the performance of the final product,
there is generally a concensus of opinion among the individuals/organizations
interviewed that failure to properly address the problems at each and all of
the steps can lead to inadequate liner performance. Thus, a weak or broken
link in the required chain of custody for quality control and quality assurance
(QC/QA) is believed to be conducive to poor liner performance. Given the
standard business practice of selecting contractors based on evaluation of the
bids submitted, cost consciousness, and the intense competition which often
promotes underbidding, there exists, therefore, an ample opportunity for the
occurrence of weak links and hence inadequate liners.
Educating customers to recognize the importance of and the need for
maintaining an unbroken chain of QA/QC, to demand comprehensive QA/QC programs
at all stages of design, manufacturing, etc., and, above all, to consider
factors other than cost In selecting contractors was most often cited as
perhaps the only practical solution to the liner installation problem. The
very slow nature of such an education process, however, Is recognized and
measures such as organization of the profession and dissemination of informa-
tion on the latest developments in liner technolociy (e.g., via the holding of
technology transfer seminars, training sessions, etc.) are suggested as means
for speeding up the process. The use of a turn key contract management system
which makes a single party responsible for the performance of the installed
liner, or the development and enforcement of performance standards, Is con-
sidered appealing but Impractical. These approaches would increase the cost
and are fraught with technical and legal problems. These difficulties, which
could promote unwillingness on the part of contractors to bid on liner Jobs,
can best be illustrated by the reluctance of liner manufacturers to offer
meaningful and extended warranties on their products. Even when every con-
ceivable precaution is taken, including extensive overdesign, there is an
inherent statistical risk that cannot be overcome completely. In many cases,
it would also be almost impossible to pinpoint specific causes for observed
failures.
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The problem of lack of a QA/QC chain of custody is addressed tn part by
some firms/contractors which take upon themselves to “police” the operations
at certain steps which preceed or follow their own. Thus, one liner fabricator
Indicated that it requires the material suppliers to certify their product
based on certain tests which it specifies, and provides field seaming specifi-
cations based on its assessment of the capability of the Installer. In one
installation case, the site owner inspected the manufacturer’s and fabricator’s
facilities and operations as well as those of the independent laboratories they
hired. The qualifications and experience of the installers were also consi-
dered before selecting an Installation contractor.
3.2.2 DesIgn Considerations
Design engineers who were Interviewed consider proper design as the most
Important single factor In developing a successful Installation. They believe
very strongly that many of the documented cases of liner failures can be traced
to improper design and could have been avoided with the proper approach and
supporting Investigations. Thus, identification of conditions which may lead
to failure and hence developing the basis for design Is considered the first
and most important design element. Because the conditions vary significantly
from job to job, the design must be tailored to the specific requirements of
the site which must be defined in terms of the characteristics of the waste to
be handled (liner-waste compatibility), expected waste/equipment load on the
liner, site climate (wind, temperature, precipitation), and soil stability and
subsurface characteristics. The Identification of the many site-specific con-
ditions often requires an extensive geotechnical Investigation which is,
however, seldom undertaken.
The designers consider Sound structural design an Important factor in
determining the success or failure of an Installation. Important design as-
pects are considered to Include proper siting, use of a suitable side slope
(2:1 Is the limit and 3:1 is preferred), preparation of the soil support to
ensure proper and uniform compaction, use of geotextiles or other suitable
materials when rocks are likely to be a problem In the finished subgrade,
backfllling to provide adequate protection against damages from equipment and
weathering, use of protective measures (e.g., fences, intentional alternate
watering and feeding areas) to keep animals away from the operational areas,
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and installation of gas vents to release gas generated by the decomposition of
the residual organics in the subsoil. While one liner manufactUrer believes
that the thickness of its liners allows for equipment operation on the liner
without damage to the liner material, one designer feels that under no circum-
stances should operation of equipment on the unprotected liner be permitted.
irrespective of how thick the liner is.
Taking full advantage of favorable geological conditions (e.g., natural
cut-off walls and thick and homogenous clay strata) should be an important
consideration in siting disposal facilities. Other important siting consider-
ations mentioned by interviewees included availability of adequate supply of
cover material, and local sentiment and political factors. Political opposi-
tion can be a formidable force and, In some instances, has forced owners/
operators to expand existing facilities rather than seeking additional sites
in new locations. In some areas, a facility has been located in the ground-
water table (the “intragradient” design) with the objective of providing a
hydraulic gradient against leachate movement into the groundwater.
Clear and easily understood design specifications are considered by some
designers and installers as an important contribution to an adequate installa-
tion job. According to one expert, the wide differences which are observed
among bids for the same job would be substantially reduced If specifications
were written in a concise and unambiguous language. This expert also felt
that specifications requiring goals which are unrealistic or very costly to
achieve may favor low bidding by unscrupulous firms or by firms who, because
of the lack of appropriate expertise, may not recognize the difficulties in-
volved in meeting the stated goals. The term “or equal” which is often
included in specifications essentially nullifies any intent for securing a
specific product or contractor. Some experts questioned the competency and
practices of many of the design engineering firms which they hold responsible
for some of the heretofore cases of liner failure. Examples noted include the
“recycling” of certain construction drawings (e.g., detailed drawings for
liner anchor trenches) from previous projects, and reliance on inputs from
sales personnel who may lack objectivity or necessary design expertise. One
waste management company who operates a number of facilities Indicated that,
because of its poor experience with design/construction companies, it has been
forced to develop its own in-house design capabilities.
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Many of the individuals/organizations Interviewed elaborated on a key de-
sign problem, namely that of liner material selection. In evaluating prospec-
tive liners, the designers generally rely on the manufacturers’ literature on
liner properties (e.g., sheet/seam strength, high and low temperature resis-
tance, compatibilit y with various chemicals, and costs). In this connection,
one interviewee Indicated that compatibility testing should Indeed be solely
the responsibility of the supplier/manufacturer. Most of the manufacturers’
literature are derived from short-tern tests carried out under controlled
conditions and, hence, may not represent the actual field environment, espe-
cially from the standpoint of liner-waste compatibility. According to one
designer, these tests are primarily suitable for ranking materials for use in
a specific application and, even at that, the results can be misleading Inso-
far as a fully suitable material may be eliminated from further consideration.
The problem Is further complicated by a lack of uniform standards for compati-
bility testing and on the interpretation of the test results. Thus, one
manufacturer considers a sample which deforms to greater than 10 percent of
its original weight and tensile strength to be Incompatible with the waste
tested, but a strong technical basis has not been developed for this and other
arbitrary values which are in cotmion use. Because of the shortcomings of the
compatibility tests, one owner/operator felt that the selection of suitable
material for a specific application can best be made by relying upon any ex-
perience available from parallel field situations.
The selection of a suitable liner Is also complicated by the extreme
difficulty in defining the average as well as the range of fluctuations In the
waste/leachate characteristics. One designer indicated that It uses the
manufacturers’ literature to select a liner; once the liner Is selected, It
conducts its own compatibility tests to identify incompatible wastes which
will then be required to be excluded from the facility.
There is no single liner material which would be compatible with the com-
bination of wastes encountered in a hazardous waste disposal site. Based on
the results from in-house laboratory tests, one supplier concludes that the
range of wastes encountered in a disposal site can be handled by no more than
3 or perhaps even 2 FNLs. Segregation and screening of wastes (especially
that which is placed In direct contact with the liner), banning or pretreat-
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nient of certain problem wastes, the use of multiple liners to compensate for
single liner deficiencies, minimizing opportunities for contact with the
leachate (via removal of the leachate), and monitoring changes in liner charac-
teristics using coupon programs are some of the suggested approaches to miti-
gating the liner compatibility problem. Some designers consider a 2 percent
bottom slope, which is coninonly used In design, inadequate In preventing
ponding and hence extended liner contact with high strength leachate.
An inadequate data base currently exists for judging the longevity of FML
under full scale use conditions. In one county installation where the liner
adequacy has been contested, the testing of the PVC liner after 4 years of
service showed no difference In characteristics when compared to the unused
material. Because of the uncertainties as to the long-term Integrity of FML,
some designs have intentionally promoted infiltration Into the facility and
incorporate leachate recirculation during the operational life of the site,
thus accelerating the process of waste stabilization. This, It is believed,
will result in the formation of the largest volume of leachate when the liner
is new and probably better able to resist the corrosive characteristics of the
leachate.
The connections between the liner and the structure Is an important but
often overlooked problem in design. The liner Is especially susceptible to
failure at such connections due to heavy stresses resulting from differential
settlement, gravity pull on slopes, and Incompatible expansion/contraction
characteristics. Since connecting to structures is usually one of the last
Items of field activity (and hence Is often done in a hurry), the connections
generally also receive inadequate quality control. The designer can address
the connection problems by avoiding certain geometries (e.g., sharp corners
which are not easily handled), specifying compatible materials, and requiring
greater quality control. One interviewee suggested doubling the thickness of
the liner at connections to better resist abrasion around structures.
3.2.3 Installation (Seaming Problems )
Next to poor design, inadequate seams (especially field seams) are cited
as the most comon cause of liner failure. The people associated with the
liner industry and the design engineers are generally in agreement that, with
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the present equipment and technology know-how, field seams can be made so that
they will not fail. They, however, also agree that In actual practice there
is not always an adequate QA/QC program In effect to ensure compliance with
the recomended seaming procedures, and the seaming Is not done under speci-
fied weather conditions. The owners and operators of hazardous waste disposal
facilities cite from their own experience specific cases of liner failure to
support their assertion that the present practice and technology cannot In all
cases guarantee Installation of liners that will not fail. The large number of
factors which affect seam integrity (and, hence, necessitate the use of ex-
perienced labor), the lack of adequate quality control and quality assurance on
many installation jobs, Inadequacies of some of the seam testing methods, and
poor seaming specifications are among the factors most often cited by the inter-
viewees as the causes of poor field seams. Although the impact on seam quality
varies somewhat with the specific seaming method used (e.g., solvent seaming
vs. heat welding), extremes of temperature, high wind and precipitation (“wet
jobs”) can result in poor bonding and, hence, Inadequate seams. There appears
to be some differences of opinion regarding the suitability of solvent seaming.
Thus, while one designer indicated a preference for solvent seaming because of
its ability to consistently produce high quality seams and to enable easy
visual inspection of the finished seams, another Interviewee felt that in the
solvent seaming process the solvent attack might become excessive and, hence,
possibly damaging to the liner.
The ability to recognize job-specific requirements and to pass on-the-
spot judgement as to the adequacy of the field procedures and, hence, of the
resulting seams, requires that the workers assigned to the seaming jobs have
some prior seaming experience or be at least supervised by very experienced
foremen. Most interviewees, however, point out that in actual practice this
is seldom possible and, In most cases, economic considerations force many
installers to hire untrained local labor, often directly from the unemployment
line. (The use of local labor Is also often a deliberate act to get around
some of the labor union restrictions.) The problem of finding experienced
seamers is compounded by the fact that the type of seams and the skills re-
quired for each type vary with the type of lining material which, In turn,
changes from job to job. There are also variations in the seaming specifica-
tions for the same material supplied by different manufacturers.
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The Issue of suitable supply of skilled and reliable labor force at a
reasonable price for seaming tasks has been addressed, at least in part, by a
number of installers who report successful experience with training and use of
off-duty firemen and policemen. To provide for continuity of service and
hence accumulation of experience, one installer in the Southwest has success-
fully used a group of so-called “camp followers” who are encouraged to follow
the Installer from job to job; the camp followers themselves usually spread
the word as to the location of a forthcoming job and, because of the reasona-
bly high pay which is sometimes involved with contracts requiring a “prevailing
wage clause”, are willing to provide their own transportation to relatively
distant new job sites. Some fabricators who also provide installation service
have successfully engaged their factory personnel in the actual Installation
work.
The importance of adequate supervision and use of capable foremen who can
guide/teach the individuals carrying out the actual seaming was pointed out by
several of the installers and designers. It is generally considered that a
good foreman can adequately compensate for the lack of previous experience of
the crew members. For this reason, and because it is not practical to require
previous experience from all individuals engaged in seaming, there were a
number of suggestions that any training/certification program should be di-
rected at the foreman level. One expert expressed some skepticism as to the
effectiveness of a certification/licensing program to weed out poor installers.
One interviewee suggested that any training, certification, or licensing pro-
gram could probably be financed via a user fee attached to the facility permit.
The question of material compatibility with the waste is considered some-
what less critical in designing covers than liners. Weathering and uv resis-
tance are considered the Important criteria in the selection of material for
caps. While most designers recomend only the use of unreinforced material
for caps (to provide ability to elongate in response to any subsidence),
another expert considers reinforced material more suitable. A 2 percent slope
Is considered an adequate design for preventing ponding on the top surface of
the cap. Proper design also requires adequate prior compaction to prevent
extensive subsidence, and use of protective cover material (gravel or soil).
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To reduce potential for slippage of the soil cover, some designers suggest the
use of a geotextile at the FML-clay interface.
According to one fabricator, only few installers can be “trusted” with
simple overlap field seams, which presents the greatest opportunity for mis-
takes. For most Installers, this fabricator specifies tongue—and-groove seams
which it fabricates for field installation. A number of contractors and
owners/operators of disposal sites have used various criteria to screen poten-
tial installers. These criteria Include passage of written and mock seaming
tests, and the extent of previous experience (judged, for example, by the
square footage of liner installed). One designer indicated a noticeable Im-
provement in seam quality by numbering the seams on design drawings and re-
cording the Individual assigned to specific seams. In the opinion of one
expert, firms specializing In Installation would generally have a wider range
of installation experience, including involvements in some very difficult In-
stallation jobs, than firms which are engaged in manufacturing and fabrication
as well as installation. One interviewee pointed out that on occasions some
dirt contractors who have not been very experienced in liner Installation have
beeo hired to also do the actual Installation, and the outcome has been less
than satisfactory. Some opinions were expressed as to the quality of work and
stability of small vs. large Installers. One interviewee Indicated a preference
for smaller contractors which he characterized as being more anxious to do a
quality job and more receptive to technical inputs from manufacturers, designers,
and fabricators. Large installers, however, are viewed as being financially
more stable and better equipped to handle business fluctuations than smaller
contractors and, hence, more likely to remain in business after a work is com-
pleted and their services may be needed for follow-on or repair works.
The many job-specific factors which can affect seam properties In parti-
cular, and liner Integrity In general, underline the need for an effective QA
program during liner installation. It should be the responsibility of the QA
Inspector to ensure compliance with design specifications, Including testing
of seams in the manner specified. To be effective, the inspection should be
carried out by an independent party not affiliated with the installation con-
tractor. The presence of an inspector on site would also discourage sloppy
operation and unauthorized deviations from the design specifications. Some
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interviewees Indicated that the competency of the Inspector is very essential
and cited a number of examples where the Inspector assigned to a job lacked
credentials and technical expertise to properly discharge his QA/QC responsi-
bility. One interviewee Indicated that, on occasions, installers have raised
their price or modified their contract after learning that a particular In-
spector with the reputation of being very thorough and critical had been
assigned to a specific job.
Although there is agreement among the industry representatives and ex-
perts interviewed as to the need for a comprehensive QA/QC program, the scope
of such a program is not clearly defined and Its impacts on the overall cost
of installation is not quantified. For example, there are some uncertainties
as to the effectiveness of a number of seam testing methods (e.g., visual
inspection or ultrasonic test) and the material—specific applications and
significance of methods for testing seam strength and integrity. In a number
of cases, experience seems to indicate a preference for the peel test over the
shear test. It is also noted that the effectiveness of various tests vary
with the liner thickness, and field temperature and humidity conditions. Some
installers have developed and used patented seaming methods which they claim
are superior to the standard technology. One expert pointed out that a
sufficient number of seam testing units are not always available at the
job site, and this can result in testing to significantly lag seam construc-
tion, thereby promoting less than proper testing of seams.
In general, a good quality assurance check for seams Is considered to
Include nondestructive testing of 100 percent of the seams. Unless certain
precautions are observed (e.g., in unannounced inspections, requiring the
seaming crew to construct a test seam on scrap material using the exact tech-
nique that was Just being used on the liner), mock seams constructed especial-
ly for QA testing would not be representative of the quality of the installed
seams. In one field installation, the peel failure rate for cut-out peel
samples was significantly lower than for the mock seams. While some re-
searchers see no reason why the patches installed to fill in where the cut-out
samples were taken should create a lower quality material, others believe
that destructive testing can be detrimental to the liner Integrity. To be
effective for quality assurance purposes, cut-out samples should be taken from
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unspecified locations (unknown to the seaming crew) and not only from the
edges of the liner, as has sometimes been suggested to limit any possible liner
damage to the less critical areas. Quality assurance programs should especial-
1y address quality of liner connections to structures. Since these connections
are usually made last, and the contractor Is anxious to move Its crew to
another job, either the work is done In a hurry or an Inexperienced crew is
sent to finish the project.
At least from the Incompatibility standpoint, seams in the FML caps pre-
sent less critical problems than those in the bottom liners. Cap seams are
not subject to as severe Incompatibility conditions as the bottom liner seams,
and would be accessible for repair in case of failure. Seaming new liner caps
to old (aged) bottom liners (or seaming of different liner materials) is con-
sidered to present some installation problems. Good seams, however, can be
achieved by removing the surface cure from the old material prior to bonding.
Even though factory seams are generally considered superior to field
seams, in the view of at least one expert, this Is not necessarily always the
case. This expert also believes that, compared to the European practice,
field installation techniques and quality control are superior in the U.S.
Poorly written seaming specifications which are difficult to follow are
considered by some experts as a major problem area in liner installation. For
example, it is pointed out that for a reinforced liner the specifications
frequently give the SISCr 1m_to_scrimll overlap requirement. This, however, is
difficult to maintain since the distance between the end of the scrim and the
edge of the sheet always varies widely because the scrim is very flexible and,
during manufacturing, it cannot be held in place when It Is laminated between
the panels.
3.2.4 Raw Materials and Manufacturing Considerations
Few companies can be considered as major suppliers of raw elastomers (In
the form of latex or chips) for the manufacture of FML. With some exceptions,
the suppliers are not generally involved In and have no direct control over
the subsequent manufacturing, fabrication, and installation steps. Suppliers
and, to a lesser extent, the manufacturers, however, are major companies with
assets which are generally substantially higher than those of a typical
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fabricator or installer, and hence are attractive targets for any litigatlons
stermilng from damages from liner failures In waste disposal application.
Because of this and their desire to avoid bad publicity which could be damaging
to their markets, suppliers and manufacturers generally feel some corporate
responsibility for the ultimate performance of their products. Some suppliers
thus have active programs to interface with and advise manufacturers, fabrica-
tors, designers, and installers on such topics as material compatibility,
proper design and installation procedures. One supplier interviewed has ex-
tensive R&D effort for testing, screening, and improving product quality.
Unless involved in the manufacturing step, suppliers exert no control
over the selection of compounding ingredients (e.g., carbon black, pigments,
fillers, plasticizers, accelerators, and antloxidants) used In manufacturing
to impart various properties to the finished product. The current material
specifications are too broad and hence permit significant variations in the
properties of the same liner type from different manufacturers. Thus, speci-
fications for Hypalon merely require that the material contains at least 45
percent by weight of Hypalon 45 as the sole elastomer, and meets certain
physical criteria. Consequently, as with all generic classes of liners (e.g.,
PVC, HDPE, EPDM, etc.), Hypalon liners available from different manufacturers
may vary widely in properties. Beyond requiring compliance with this minimal
specification, the suppliers exert no control over manufacturing and cannot
refuse to sell their elastomer products to any manufacturer. Several inter-
viewees, however, indicated that withholding of the product from unscrupulous
customers can be an effective quality control measure and should be exercised
by responsible suppliers, manufacturers, and fabricators. This variation in
product quality has been a major impetus for the current effort of the National
Sanitation Foundation to develop liner standards applicable to the manufactu-
rers (and fabricators) of FML.
In addition to the specific formulation which affects liner properties,
the method and equipment used in manufacturing also have significant Impacts
on the properties of the finished sheets. One expert compared calendering and
spread coating methods of sheet manufacturing from the standpoint of product
quality and quality control. Spread coating, which involves building up of
the sheets from layers of material applied as liquid coats, is considered to
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provide less opportunity for pinhole development and to allow the use of higher
scrim densities for reinforced products. The extent of recycling scraps
(especially reinforced material scraps which contain scrims) to the polymer
melting pot also Impacts product quality, and there Is currently no standards
governing the extent of recycling which can be tolerated. One owner/operator
who also manufactures synthetic sheet materials for miscellaneous uses Indi-
cated some quality assurance problems in the manufacturing of synthetic liners;
the company, for example, has experienced difficulties with thickness, rein-
forcing scrim, and material uniformity.
One FML manufacturer indicated that its QA/QC program lr .cIudes: (a) sam-
pling at top and bottom of each raw material rail car; (b) visual inspection
of product as it rolls off the production machine; (C) laboratory testing of
at least two samples of the finished product per shift; Cd) documentation,
including batch coding, date coding, and numbering of each role; and (e)
issuance of a quality control certificate to the customer. One Interviewee
suggested that quality control in the manufacturing step is often Inadequate
and that several new and potentially very effective techniques such as spark-
gap and vacuum testing are not yet In widespread use.
There appears to be significant differences of opinion among the experts
Interviewed on the pinhole problem and Its significance In liner performance.
Thus, while some indicate that it IS not possible to produce pinhole-free
liners, there are others who believe that pinholes in liner sheets is a problem
of the past and that the present manufacturing methods, and the quality con-
trol which is exercised In the manufacturing step, can guarantee liners without
pinholes. There appears to be a lack of technical data to support either
assertion. Some manufacturers which were interviewed Indicated that their
material would be “nominally” pinhole-free and that they “would be hard put”
to guarantee that their product is completely free of pinholes. Pinholes which
penetrate the liners are considered less of a problem for multi-ply than for
single-ply liners because the chances of a pinhole In one ply matching up with
pinholes In a second ply are very small. There might be some potential pro-
blems, however, if a pinhole exposes the scrim such that contact with waste
fluids could cause wicking along the scrim, build-up of fluid between plies,
and eventual delamination. The probability of this happening, however. Is
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very small and it might only be a potential problem with tightly-woven scrims
and thick yarns.
Pinholes can originate during the calendering process where air bubbles,
contaminant particles, or poorly dispersed granules (e.g., unmelted modules of
carbon black or scrim scrap) in the mixed stock can mar the otherwise smooth
surface between rollers and result In indentations which pass through the liner.
The pinholes can vary In size, from a few microns in diameter to a size which
can be spotted by the naked eye when the sheet is held against light (e.g.,
passed over a light bar). Quality control for pinhole prevention during manu-
facturing can Include fine screening of the mixed stock before calendering or
extrusion, limiting the amount of scrap recycling, and visual inspection of the
sheets on both sides to Identify and repair pinholes.
Technical data have not been generated through any systematic studies to
enable quantitative assessment of the significance of and the extent of problem
with pinholes in liner performance. Liner designers and Installers generally
down-play the significance of pinholes In liner performance and find little
evidence indicting pinholes In liner failures. One designer reports that, based
on oi e study with a water containment system 1 2000 pinholes may be considered
equivalent to one hole of 10 m diameter or ten holes of 3 m diameter. The
amount of weepage through pinholes would probably be orders of magnitude less
than through a bad seam or a substantial tear. Moreover, since all liners
possess sufficient puncture resistance, pinhole enlargement during actual use
would be unlikely.
One expert pointed out a general misconception that the thickness of a
liner is the principal factor determining Its performance. He Indicated that
he has actual comparative test data which prove, at least from the viewpoint
of resistance to puncturing, that the “thicker is not always the better”.
Most warranties offered by manufacturers are generally very limited in
scope and, in the opinion of some, are “full of holes” (especially the exten-
ded warranties). In most cases, exceptions are taken to incidental and conse-
quential damages which could occur as the result of liner failure. These
warranties generally limit liability to a dollar amount which does not exceed
the selling price of a particular project.
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The technical experts most familiar with the European technology Indicated
that overall, the quality of the liner products manufactured lnthe U.S. are
superior to those of European counterparts.
3.2.5 Fabrication and Transportation
Transportation of the liner material from the manufacturing facility to
the fabricating plant, and from the fabricating plant to the Installation site
offers opportunities for damage to the liner product. Visual Inspection at the
fabrication plant (both before and after seaming) as well at the Installa-
tion site as the material Is unloaded Is generally considered necessary to
detect transportation-related damages (or other faults). There are generally
two methods of transportation which can be specified In the bid specifications:
“FOB plant” and “FOB site”. It would be to the advantage of the site owner to
select “FOB site”, as this would transfer the responsibility for transportation
to the job site, including writing of all specifications (e.g., crate specs)
and handling all damage claims, to the shipper. If damages are substantial
and cannot be repaired on site, the shipments should be rejected.
The factory seams are developed by a number of methods, with the choice
beit g dependent on the liner material. Some fabricators have developed special
modifications to the standard equipment designs which they claim enable them
to Improve seam quality. One fabricator which uses heat-weld seams Indicates
that, with reinforced thermoplastic material and 2-inch overlap, Its particular
techniques can duplicate the strength of the material in the seam. The QAIQC
program employed by this fabricator reportedly includes the use of “peel test”
on test seams to establish optimum seaming conditions (temperature, pressure,
and speed), use of experienced operators/technicians, visual Inspection of
seams for extrusion of material at the interface of the welded sheets, stress
and creep testing of seam samples, and use of tick marks to ensure proper
lining of sheets prior to feeding into the seaming machine (to avert stresses
being built into the seams).
3.2.6 Research and Development Needs
Many of the cotrinents received from the interviewees on FML-related R&D
needs pertained to: (a) establishment of a better basis for design through
systematic and “real world” studies; (b) development of Improved seaming
methods, compatibility tests, and liner materials for specific applications;
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and (c) Investigation of new concepts and approaches to seaming. Some experts,
particularly those confronted with the “real world” problems, see laboratory
test results as a poor substitute for design data coflected through systematic
studies of the performance of liners and design approaches In fufl-scale
applications. Thus, while research to date is considered very fruitful , it is
suggested that It be extended to also address some of the practical concerns of
the design. Some of these concerns relate to the following:
• Development of better design/construction criteria for connecting liner
to concrete structures in liquid impoundments.
• Development of better sump systems for landfills to allow more durable
connections (the concept of a prefabricated unit is considered worth
investigating).
• Definition of conditions where geotextiles can be cost-effectively used
In conjunction with reinforced and unreinforced FIlL.
• Observation of the performance of liner in actual field Installations
or in “prototype” cells dedicated to systematic studies. These studies
could, for example, address the behavior of liners and seams In deep
and shallow ponds and under a range of exposure conditions.
• Scientific cause-and-effect investigation and documentation of the
reported cases of liner failures (and successes).
• Investigation of new concepts to seaming (e.g., use of a “mechanical
zipper”), development of new seaming methods, and test and evaluation
to generate the technical basis for more concise seaming specifications
(e.g., as to the required overlap width).
In underlining the need for documentation of liner failures and successes,
several Interviewees pointed out that some data currently exist in the files
of manufacturers, designers, and installers, but such data are considered con-
fidential and hence not releasable. Several interviewees emphasized the need
for Improvements in liner performance tests (in particular compatibility and
permeability tests), and for quantification of the credibility of the test
results In predicting performance under field conditions. Especially needed
are accelerated tests which can condense 25 years or more of service into a
short period of laboratory tests. To be of greater value, compatibility tests
should utilize actual leachate solutions representative of leachate character-
istics. To this end, information is needed on the characteristics of leachate
from large-scale facilities and the time variance and waste source dependency
of such characteristics.
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Two interviewees saw a great demand for developing suitable liner mate-
rials for certain specific service requirements (e.g., containment of brine
and low pH wastes). Although compatibility with waste generally has been con-
sidered of little concern in selecting liner material for covers, the magnitude
of the problem (especially in cases involving volatile wastes) has not been
addressed and must be researched. One interviewee pointed out a much broader
need for an investigation of viable alternatives to landfllllng or restricting
the use of landfills to those wastes which cannot be handled by other disposal
methods. He also suggested Investigating the technical and economic merits of
using above-ground containment systems where any liner used would be more
easily accessible for observation and repair.
3.3 FACTORS AFFECTING CLAY LINER PERFORMANCE AND MEASURES FOR MITIGATING
PROB LEMS
3.3.1 General Considerations
Some of the problems associated with producing a quality FML installation
(e.g., deficiencies In design, Inadequate QA/QC, material incompatibility, etc.)
also apply to clay Installations. Additional problems with clay liners which
were pointed out by a number of Interviewees related to general over-reliance
on construction techniques and experience from other geotechnical projects and
the inadequacies of the data presented to support the asserted good performance
of certain operating clay-lined facilities. Thus, it is stated that not all
practices and experience from dam and embankment construction would be appli-
cable to or should be used in constructing clay liners. For example, the
degree of compaction used In the construction of large embankments may not be
suitable for liners. Some of the problems with clay liners have Indeed been
attributed to faulty designs developed by engineers and hydrologists who are
familiar with saturated flows when In liner/cap application, the clay is, in
fact, placed in an unsaturated condition. One expert suggested that Input of
a soil scientist night be helpful to avoid certain design problems and pointed
out that various properties of clay, especially under varying conditions of
moisture content, are very poorly understood. In this connection, one owner/
operator indicated that because of the inexact nature of the soil science In
designing his facility, he solicited inputs/opinions from two different geo-
technical consul tants.
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Some experts question the validity and comprehensiveness of some of the
data which are presented to indicate adequate performance of operating clay-
lined facilities; it is felt that, unless support data are obtained through
systematic and well-designed extended studies, the long-term performance of
clay liners (as well as FMLs) in hazardous waste disposal site application will
continue to remain a matter of speculation and controversy. Thus, while clay-
lined facilities for which there is no apparent evidence of failure are cited
by some to indicate a lack of Incompatibility problem, others make references
to documented cases of clay liner failure due to Incompatibility and cite the
research carried out by Dr. Kirk Brown of Texas A&M University Indicating
marked Increases In clay permeability upon exposure to high-strength organic
solvents. Both Dr. Brown and other researchers, however, point out that the
referenced research results are preliminary and that the test conditions used
to obtain data (i.e., high pressures and use of concentrated waste streams) do
not represent all field conditions.
As noted previously, and despite the above-listed shortcomings, a segment
of the individuals/organizations Interviewed (particularly those associated
with the operation of waste disposal sites) indicated a very strong preference
for clay. Even those associated with the FML industry see justifiable uses
for clay and there seems to be a consensus of opinion that a clay-FML combina-
tion offers the best protection. Some of the advantages cited for the use of
clay over FML were reviewed in Section 3.1; these and other asserted advantages,
some of which are not supported by technical data, include the following:
• Fewer steps and parties involved, and simpler procedures for develop-
ing a completed installation. There is thus less opportunity for
mistakes and the problems are more manageable.
• More developed state-of-the-art due to considerable experience with
other geotechnical projects (e.g., construction of dams and embank-
ments).
• Favorable operating experience with sanitary landfills sited on native
clay deposits and from limited sites lined with recompacted clay.
• Less catastrophic failures and the ability of clay to attenuate pollu-
tant migration In case of failure.
• Better ability to resist mechanical damage due to the much greater
thickness of the clay liner.
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As with FML, two problems which were cited as being niost Important in pro-
ducing a quality Installation relate to deficiencies in design and inadequate
QA/QC during clay liner installation. These are briefly reviewed below.
3.3.2 Design Considerations
The importance of design and some of the general design considerations
discussed in Section 3.2.2 in connection with FML are also applicable to clay
liners. These common factors, which will not be elaborated upon here, Include
Identification of conditions which may lead to failure through site surveys
and geotechnical Investigations, tailoring design to meet the Identified con-
ditions of failure and site-specific requirements, proper siting of the
facility, use of suitable slopes, preparation of adequate support for recom-
pacted clay liner, use of clear and easily understood specifications, and
design of suitable structures for leachate collection and removal.
Except where a facility is underlaid by a relatively thick and homogenous
clay stratum, native clay is not generally considered a suitable liner because
of the presence of discontinuities (sand and silt lenses, roots, and debris).
Some of these discontinuitles can escape even the most comprehensive geologi-
cal Investigations. Some concern was also expressed about the wisdom of
undertaking an extensive geological Investigation involving soil borings, as
such borings can introduce their own discontinuitles and hence promote down-
ward movement of leachate. When clay is available at a site, It should thus
be recompacted to improve uniformity and eliminate major discontinuities.
Although there are some state guidelines as to the thickness or the permeabi-
lity of clay liner (e.g., Louisiana requires a minimum 3-foot clay liners for
hazardous waste facilities), such guidelines generally vary.
Based on the Interviews, there appear to be two distinct design philoso-
phies for the management of leachate In a clay-lined facility. One school of
thought, which is promoted by designers, sees a need for the removal of
leachate for above-ground treatment and disposal. Leachate removal Is con-
sidered necessary to reduce potential for liner deterioration due to Incompa-
tibility with waste, and to reduce the hydraulic head which can promote liquid
penetration. The concept of intentionally allowing the leachate to percolate
into and be absorbed by the liner, as is advanced by a second group of experts
(represented by certain researchers), is considered a potentially dangerous
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proposition and contrary to the goal of protecting groundwater. It is thus
pointed out that the poorly understood chemistries and transport mechanisms
involved preclude proper assessment of the capacity of clay to absorb various
chemicals present in a complex leachate solution and, hence, It Is not possible
to develop the proper basis for liner design to accon odate leachate. The
objective of leachate collection and removal Is viewed as one of transferring
hazardous and potentially mobile material from a difficult-to-control environ-
ment (i.e., the landfill) to a more easily controlled environment (e.g., an
above-ground treatment system).
Those who promote the deliberate percolation of leachate into the clay
liner view any effort at leachate removal contrary to the concept of permanent
waste disposal, since it implies perpetual care. These experts contend that
leachate collection is neither needed nor desirable, and that clay liners
should be designed to accomodate leachate absorption. To avoid accumulation
and overflow, it is also recomended that the cap for a facility be designed
to be less permeable than the bottom liner. One Interviewee, however, pointed
out that this might not be practical in all cases since permeabilities less
than that for coninonly developed bottom liners (10-8 to lO cm/sec) may
not be readily achievable. To lessen the strength of leachate and hence the
load on the liner, It is further suggested that disposal of liquids and very
troublesome wastes in landfills should, with only few exceptions, be eliminated.
Perspectives expressed regarding cap designs generally point out the
difficulty of developing a system (clay, FML, or other materials) that can
remain viable over a long period. While some experts favor caps constructed
of clays or other natural materials, most agree that all caps are subject to
deterioration due to subsidence and erosion and must be repaired. Although
subsidence will occur in every case, it can be minimized by proper design
which will reduce the amount of moisture entering the facility. One researcher
cited that in Northern Illinois where there are only 30 to 34 Inches of rain
per year, only 2 percent of the precipitation normally reaches the groundwater.
By comparison, infiltration into poorly designed/constructed caps can exceed
60 percent. A different philosophy on cap design was expressed by some state
regulatory agencies who favor design to intentionally promote Infiltration to
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accelerate waste stabilization which is further aided by leachate recircula-
tion during the operational life of the facility and before placement of the
cap.
Coninenting on regulations requiring a specific thickness for clay caps,
one researcher pointed out that a uniform requirement would not be applicable
to all sites. Thus, a 2-foot compacted clay would not be sufficient in certain
cold climates where, In winter, the frost line may extend to more than 30
Inches deep. The thickness of clay caps which have been used tn actual In-
stallations has varied and depths of up to several feet were reported. The
w1 dom of planting grass in the soil cover for the cap was questioned by one
researcher on the grounds that while such practice might minimize erosion, by
holding water it can increase infiltration. It Is cited that compared to row
crops such as corn, Infiltration with a grass cover may be four to five times
higher.
One researcher is investigating a cap design with a gravel layer sand-
wiched between two clay layers. In this system, which is believed to offer
good long-term perfomance, the gravel layer perches the water in the upper
cla y layer where It Is removed by evapotranspiratlon during dry weather condi-
tions. During the wet weather conditions 1 when the storage capacity of the
top layer Is exceeded, some of the water would be transmitted to the gravel
layer and drained out and away from the site.
3.3.3 Installation Considerations
As with FML, inadequate Installation Is ranked next to poor design as the
most connon cause of failure of clay liners. Elements of good installation
practice Include proper care to identify and eliminate discontinuitles in clay
during excavation, use of acceptable equipment operating practices during
liner emplacement and compaction, development of proper and uniform moisture
level during compaction, and use of protective measures to minimize dessica-
tion and cracking prior to use. A quality assurance program which will ensure
compliance to recomnended procedures during each step of Installation is
essential to the development of an adequate installation.
Removal of discontinulties in clay (sand and silt lenses, roots, etc.) Is
very essential to ensure the Integrity of a recompacted clay liner developed
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from clay excavated from the site. (One interviewee, however, indicated that
sand lenses would only present problems if they are hydraulically connected).
In practice, however, the critical task of removing discontinuities has often
received inadequate attention due to time and hence cost considerations.
According to one expert, failure to eliminate silt lenses have been respon-
sible for inadequate performance of several surface impoundments, and similar
cases of landfill failures have been attributed to such discontinuitles In the
finished liner although, in the case of landfills, the cause-and-effect rela-
tion is more uncertain due to the inaccessibility of the buried liner. Because
of the Inability of an average equipment operator to identify subtle discon-
tinuities (in particular, presence of silt lenses since they generally resemble
the surrounding clay in color and texture), one expert feels that the presence
of a highly qualified inspector at the site during excavation to watch for
sand and silt lenses is almost mandatory.
Use of proper construction techniques and adherence to acceptable equip-
ment operating practices during liner emplacement and compaction are considered
necessary to avoid possible damage to the finished liner. Thus, use of in-
appropriate techniques (e.g.. use of standard road construction practices) and
careless equipment operation (e.g., dead standing turns) which could wreck, to
varying degrees, work that Is supposedly completed, should be avoided. This,
however, is considered to be much less of a problem than with an FIlL since,
because of the thickness of the clay liner, damage would be limited to the sur-
face (it will not penetrate through the liner) and can be more readily spotted.
Development of proper and uniform moisture level in clay during compac-
tion is very essential to the performance of a finished clay liner. Case
study research data developed by one interviewee Indicate that soil compacted
“dry of optimum can be several orders of magnitude more permeable than soil
compacted at or greater than optimum. The reconinended practice is to compact
the clay wet of optimum to about 95 percent of Proctor test density. Non-
uniform addition or distribution of water and failure to break up large clods
during compaction can result in the formation of cracks and clods with wet
surfaces, but dry, cracked interiors that will allow rapid leachate migration.
Thus, during compaction, large clods of clay must be broken up. It is corisi-
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dered that clods larger than 3 inches should be eliminated, but a maximum of
6 Inches may have to be tolerated due to the limitations of current technology
and equipment. Nonuniform and Inadequate moisture level can also result from
Inadequate time allowed for water to penetrate clay. The difficulty is espe-
cially pronounced on side slopes where much of the water may run off, sometime
forming pools at the bottom of the slopes.
Unless adequate measures are taken to prevent moisture loss, an installed
clay liner is subject to dessication and cracking. It was cited that cracks
extending 6 to 8 inches can form following a single day’s exposure to ambient
conditions. Conflicting views were expressed as to whether or not in actual
practice necessary precautions are taken to protect the liner. Thus, while
one interviewee indicated that installers are not generally careful about
protecting the newly constructed portions of a liner, a number of other Inter-
viewees disagreed. In any event, there is a general agreement that protective
measures are very effective and easy to Implement, These measures include
use of a temporary cover such as a thin layer of asphalt, a layer of soil, a
plastic sheet, or even a layer of rock rubble. Alternatively, the liner can
be constructed a foot or so thicker than required with the extra thickness
scraped off before the liner is placed into service.
Laboratory permeability tests have been shown to be inadequate for
assessing the quality of an installed clay liner. Based on a thorough evalua-
tion of design and actual performance of several clay-lined impoundments, one
researcher showed that the actual permeability of an Installed liner may be 2
or 3 orders of magnitude greater than that predicted by laboratory permeabili-
ty tests. In addition to possible dessication which may have occurred between
the end of construction and beginning of operation, the differences were
attributed to the inadequacy of laboratory tests to simulate field conditions.
The problem was attributed to: (a) differences in compactive effort between
laboratory and field conditions; (b) the small samples used in laboratory not
being representative of the overall liner; and (c) laboratory samples being
uniformly moistened prior to compaction whereas uniform moisture distribution
may not be attainable in the field. One research group indicated that it does
not use permeability tests on Installed liners, but rather conducts soil densi-
ty tests to ensure compaction to 95 or 98 percent of Proctor test density.
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3.3.4 Research and Development Needs
Some of the general R&D needs discussed In Section 3.2.6 In connection
with FML (e.g., development of a more extensive data base for design through
systematic studies of long-term performance of actual facilities, investigation
of alternatives to Iandfilling of certain wastes, and transfer of technical
information to field personnel and permit writers) are also applicable to
clay-lined facilities. Suggested R&D works more specific to clay include the
following:
• Development of better design/construction criteria for clay liners (e.g.,
lift thickness, method of moisture distribution, compaction, etc.).
• Assessment of liner compatibility (long-term changes in permeability)
with actual leachate and model wastes or simulated leachate.
• Development of laboratory permeability tests which would more closely
correlate with actual fiel data.
o AdditIonal studies of clay/natural soils attenuation with organic
chemicals.
• Assessment of contaminant transport In fine grain sediments, including
in fracture networks.
• Stu ies of the validity of Darcy’s law at permeabilities of 10-7 to
l0 .o cm/sec, including the effect of the porosity term used in the
relations hi p.
• Investigation of the bonding energies of clays with organics versus
water.
• Assessment of the effect of subsidence on rate of infiltration through
clay caps.
• Standardization and survey of methods used to measure design parame-
ters and assembling of information on current practice in one location.
• Investigation of use of chemicals such as lime or limestone on top
of the liner to effect in-situ neutralization of leachate.
One research group with extensive experience with soil l1ner used in
potable wtc’r applications suggested the following two research Lich
could have applications to engineered clay liners for waste disposal: (1) use
of dispersants to compact soils to higher densities, and (2) development of
methods to evaluate soil liners after placement without violating liner inte-
grity.
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3.4 PERFORMANCE CONSIDERATIONS AND PROBLEM MITIGATION MEASURES FOR OTHER
LINER TYPES
3.4.1 General Considerations (Comparison with FML and Clay )
Reflecting the lesser uses of liners other than FI’L and clay, a consider-
ably smaller data base exists for these other liner types. There are usually
only a few suppliers for each type of these “specialty products” and, with some
exceptions, the suppliers seem to hold a monopoly on the available experience.
The key exception Is the asphaltic concrete, where the product and the method
of its use are the same or modifications from pavement/highway construction,
and this Is cited both as an advantage (existence of extensive experience) as
well as a disadvantage (not taking into account unique liner application re-
quirements) of these products. In general, what little performance data that
have been made public by the suppliers appear to be aimed primarily at promo-
ting the product and, hence, may not be objective; the data also appear con-
tradictory and have not been independently verified.
The specialty products for which varying amounts of Information were
collected In the Interviews are asphaltic rubber, asphaltic cement, asphaltic
emulsion spray-ons, and bentonite soil admixture. In general, the suppliers of
these liners claim the following advantages for their products:
• Absence of seams - The Installed material forms a continuous liner,
thus eliminating the seaming problem which is a major drawback for
FML.
• Involvement of fewer parties In steps leading to and including Instal-
lation - Because only one or two firms are usually involved in the
design of the mix and in the actual installation, there Is probably
less opportunities for mistakes and for quality compromises, and the
supplier can also exercise tighter control to ensure proper product
use.
• Formulation to acconinodate site-specific variations - Based on previous
experience and some laboratory tests, the mix of ingredients for
bentonite and asphaltic rubber can reportedly be adjusted to respond
to specific application conditions (e.g., type of soil and waste
characteristics).
• Suitability for caps - Since bentonite is reportedly more flexible
than clay or soil, and asphaltic liners can undergo a substantial elon-
gation (perhaps in excess of 300 percent), both materials should be
suitable for caps. One firm also claims better uv-resistance and
chemical-resistance properties for asphaltic emulsion than for most
FMLs.
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Many of the obstacles to producing quality installation with F?IL and clay
are also applicable to the specialty liners. Most noteworthy of these relate
to deficiencies In design and lack of quality control during installation.
Quality control is especially important with these products because conformance
with the supplier’s reconinended procedures is very necessary to ensure a qua-
lity product. Inadequate cover protection for liner, reliance on liner to
provide structural support (instead of the subgrade) are two comon design
pitfalls.
3.4.2 Asphaltic Concrete
The difficulty in developing adequate impermeability and potential In-
compatIbility of the material with the harsh nature of waste/leachate are the
two main concerns expressed by those providing Information on asphaltic
concrete liners. Most asphaltic concrete liners are constructed by general
asphalt contractors whose experience might be exclusively with highways.
parking lots, or similar applications of the material. While this considerable
experience is cited by some as a decisive advantage for using asphaltic con-
crete, there are others who point out distinct differences between the two
types of applications and note that the standard procedures might be inade-
quate to develop the characteristics needed of the material In a liner appli-
cation. To develop the lower permeability needed for use as a liner, the
mix should be modified to increase the asphalt and fines contents; a higher
degree of compaction should also be used (via increasing the number of roller
passes over the material). These required adjustments to the mix and the
installation procedures, however, are not generally done (one interviewee
indicated that the asphaltic concrete liner at his facility was based on a
standard mix established by the state for highway construction).
Even though impermeability is of significantly less concern for the
slopes than for the bottom, the difficulty In operating equipment on slopes
can lead to Inadequate compaction which can threaten the Integrity of the
material on steep slopes.
Those interviewed were also tn reasonable agreement that asphaltic
concrete would not be suitable in applications where ground movement is a
distinct possibility.
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3.4.3 Asphaltic Rubber
Better resistance to chemical attack and weathering are considered two
major advantages of asphaltic rubber over many FMLs. Tests indicate that ex-
posure to uv or ozone, for example, results only in surface degradation of
the entrained asphalt and the formation of a protective layer on the surface
which prevents degradation of the asphalt-rubber matrix of the Interior.
Asphaltic rubber, however, is a relatively new product and has not received
as much attention as FML. Based on Its apparently desirable properties, one
supplier predicted that It is only a matter of time before asphaltic rubber
Is widely used in liner applications.
Although long-term data on the performance of asphaltic rubber in waste
disposal applications are unavailable, one Interviewee indicated that based on
compatibility tests in which the time factor was compressed 1 asphaltic rubber
is at worst more durable than other asphaltic-based products. Asphaltic-based
products in general have registered long-term durability in a variety of
potable water applications (e.g., lining of canals). One supplier/Installer
of asphaltic rubber liners indicated that as part of Its R&D program (and as
a matter of policy for new applications), it routinely carries out compatibi-
lity testing using a range of chemicals at varying concentration levels; the
company believes that major Incompatibility problems would surface within 30
days.
Although somewhat more of an economic/political factor than a performance
consideration, asphaltic rubber can often be formulated to utilize some local
sources of raw materials (especially the asphalt), thus reducing cost and
enhancing the acceptance of the project by the local corTinunity.
3.4.4 Asphaltic Emulsion Spray-on
One interviewee who has carried out extensive R&D work and developed a
soon-to-be-marketed asphaltic emulsion spray-on product, believes that Its
product will be superior to most currently available FMLs. The product will
have as its ingredients elastoiners, diluters, fillers, urethane, polybentylene,
and a number of other proprietary additives. The reconinended installation
will consit of compaction of support soil and placement of a fiberglass mesh
on top of the compacted soil onto which the emulsion will be sprayed to form
3-29
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a 1/16 Inch thick layer. A double liner system can be installed by sandwich-
Ing 18 inches to 2 feet of graded material (containing the leachate detection
system) between the two spray-on liners. Excellent puncture resistance, re-
sistance to degradation by chemicals and sunlight, quick setting properties,
and absence of seams are claimed to be the major desirable features of the new
product. Although no independent data are available to confirm or disprove
the supplier’s claims, one finn could foresee no liner application for asphal-
tic emulsion spray-ons.
3.4.5 Bentonite-Soil Admixture
One major supplier of bentonite (sodium montmorillonite) and a company
providing engineering and construction services for specialty—type liners
(including bentonite) were Interviewed. The bentonite supplier considers its
product distinctly superior to convnon clay for use as a waste disposal site
liner because of the more desirable characteristics of sodium montmorillonite
and the contaminant resistance properties which are imparted to the product
by treatment with certain proprietary chemicals. According to the supplier,
low-head permeability tests conducted using a range of solutions (generally
containing about 10 percent of a contaminant) have indicated no change in
bentonite permeability upon prolonged contact with the tested solutions. The
supplier also notes that bentonite has been successfully used in tank farm
spills containment applications involving short term contacts with organic
solvents and industrial grade chemicals. Theoretically, polar compounds such
as acetone and lower alcohols at high concentration levels would be expected
to displace the bound water, thereby causing the collapse of the bentonite
structure and hence increased permeability.
The supplier’s view (and data) on the contaminant resistance property of
bentonite is challenged by one engineering/installation company who recoinnends
bentonite only for potable water liner applications. This company indicates
that, based on the results from its own testing effort, even the so-called
contaminant resistance material would be incompatible with waste/leachate and
that failure of the bentonite liner (i.e., increase in permeability) in a full-
scale application would just be a matter of time (most likely after the first
or second year of installation).
3-30
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As with clay liners, a bentonite liner is susceptible to dessicatlon and
cracking. The dessication potential, however, can be minimized during iristal-
lation by quickly covering the bentonite with soil (usually about 6 Inches
thick) or with a sheet of plastic. According to the supplier, a successful
bentonite liner installation requires: (a) prior site surveillance and labo-
ratory testing to determine the required bentonite-soll mixture and the suita-
bility of the site soil for use in the admix, and (b) strict work supervision
to ensure adherence to the recomended Installation procedures. A liner thick-
ness of 6 to 12 inches Is generally considered satisfactory.
Even if bentonite exhibited excellent performance characteristics, its
use as a liner material would be limited only to certain geographic areas
where the cost of transporting the material from mines and processing facili-
ties In Wyoming and Dakota would be acceptable.
3.4.6 Research and Oevelopment Needs
The following areas were suggested for further research and development:
• Evaluation of the effects of heavy metals and aromatics on the per-
meability of bentonite, and elucidation of the reaction mechanisms
Involved.
• Development of specific tests for and determination of those
characteristics of asphaltic rubber most Important to liner perfor-
mance. Any Independent effort should enlist the assistance of prin-
cipal suppliers who are most familiar with the product.
3.5 PERSPECTIVES ON REGULATIONS
While a number of individuals interviewed considered the July 1982 InterIm
final land disposal regulations adequate, a number of criticisms were also
raised on certain specific points in the regulations. There were also a number
of suggestions for incorporating some sort of QA/QC requirements in the regu-
lations.
3.5.1 LImitations of the Interim Final Regulations
There appears to be a consensus of opinion that land disposal regulations
should not disallovd the use of clay liners, that under most conditions a cloy-
FilL combination system could provide the most protection, and that there must
be a greater emphasis on siting factors since under certain circumstances a
3-31
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clay liner can prove very suitable. Some experts believe that the EPA ’s
decision to disallow the use of clay liners in favor of FML was very premature
and was apparently prompted by research results from the work of Dr. Kirk
Brown of Texas A&M University which Indicated that under certain conditions
some organics can increase clay permeability. It is, however, pointed out (by
Dr. Brown, among others) that the test conditions used In Browns experiments
(I.e., pure solvents and high pressures) are in no way representative of the
actual landfill environment.
There were a number of coninents on the desirability of expanding monitor-
ing requirements of the existing regu1ations and the possible pitfalls of
exempting double-lined facilities from monitoring. One designer pointed out
that such an exemption would provide Incentive to Intentionally construct an
inadequate lower liner so that any leachate passing through the first liner
would pass through the second liner, thus escaping detection by any leachate
detection system placed between the two liners. Since monitoring wells would
not be required for double-lined facilities, the escaping leachate would move
unnoticed Into the ground. For this reason, and because of the general diffi-
culty of defining and determining liner failure, performance standards are
thus not favored. Performance standards, however, were considered desirable
by some Interviewees as a mechanism for enforcing compliance and for enticing
owners/operators to seek quality contractors/installers.
With respect to FML standards, the requirement for a minimum liner thick-
ness (e.g., 30-mU) is generally considered inappropriate and a preference is
expressed for stating the requirements in terms of liner permeability. The
general difficulty of setting standards to cover all types of FML is also
acknowledged.
One owner/operator pointed out the need for writing clearer regulations.
He believes, for example, the statement limiting the depth of leachate over
the liner to a maximum of 30 cm Is somewhat confusinci without defining what
constitutes the bottom since the liners are designed with a slope and some
siltation occurs in the leachate collection reservoirs during the service life
of a facility. Also, the provision requiring operation of the leachate and
detection system until leachate is no longer detected needs some clarification
3-32
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to define, in quantitative terms, as to what would constitute “no leachate
detected” since a very low level of leachate generation would be expected for
a significant length of time.
3.5.2 QA/QC Requirements
The need for Incorporating some kind of QA/QC requirements In the regula-
tions was pointed out by several of the interviewees. It was suggested, for
example, that the submission of a comprehensive QA/QC program be required as
part of the permit application for hazardous waste land disposal facilities.
The QA/QC programs should be so designed and Implemented that they would force
owners/operators of facilities to hire competent contractors and reputable
suppliers, and to consider factors other than cost in evaluating and awarding
construction bids. This objective could be aided significantly by EPA educa-
tional programs (e.g., training sessions and technology transfer seminars)
aimed at elevating the technical familiarity of the personnel at permit issuing
agencies on various aspects of site design, construction, and operation. It
was also suggested that QA/QC programs be designed and run, not necessarily by
EPA, but by a team of qualified Independent experts.
3.5.3 Miscellaneous
There appears to be a consensus of opinion that education, and not ne-
cessarily only regulations, Is the key to ensuring environmentally adequate
waste disposal facilities. This education would also be very conducive to
Improving coninunication between regulators, designers, material suppliers,
liner manufacturers, fabricators, installers, etc. , which Is so essential to
developing adequate facilities. Improved comunicatlon can publicize cases
of failure (and success) and expose Incompetent contractors, unscrupulous
suppliers, manufacturers, etc.
Although admitting that perhaps somewhat impractical and contrary to the
present trend, one researcher suggested that regulations should promote con-
struction of more smaller landfills over construction of fewer but larger land-
fills; the failures of smaller landfills would not have very catastrophic en-
vironmental Impacts and, in most cases, the resulting damages can be corrected.
3-33
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Some interviewees attributed the shortcomings of the existing environ-
mental regulations to what they perceive as a lack of technical competence
and “real world” experience on the part of individuals writing regulations.
It is also pointed out that a very high staff turn-over, which is characteris-
tic of regulatory agencies, prevents the individuals drafting regulations (who
are asserted to be largely administrative personnel) to accumulate and apply
experience on any given subject matter.
3-34
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4. INTERVIEW REPORTS
• Suppliers, Manufacturers, Fabricators, Designers, and Installers of FML,
Clay, and Other Liners.
• Owners/Operators of Hazardous Waste Management Facilities.
• State Regulatory Agencies.
• Researchers in Academic and Research Organizations.
• Trade/Professional and Standards Setting Organizations.
4-1
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4.1 INTERVIEW REPORTS WITH SUPPLIERS, MANUFACTURERS, FABRICATORS, DESIGNERS,
AND INSTALLERS OF FML, CLAY, AND OTHER LINERS
A-i. Schiegel Lining Technology, Inc.
A-2. Sta-Fiex Corporation
A-3. Burke Rubber Company
A-4. Gundie Lining Systems, Inc.
A-5. Watersaver Company, Inc.
A-6. E.I. DuPont de Nemours & Co.
A-7. M. Putterman & Co.
A-8. American Colloid Co.
A-9. Woodward-Clyde Consultants
A-iD. Roy F. Weston
A-il. Slurry Systems
A-i2. B.F. Goodrich
A-i3. The Pantasote Company of New York
A-l4. Gulf Seals
A-l5. Arizona Refining Company
4-2
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ASSESSMENT OF TECHNOLOGY FOR CONSTRUCTING AND
INSTALLING COVER AND BOTTOM LINER SYSTEMS
FOR HAZARDOUS WASTE fACILITIES
EPA Contract No. 68-02-3174; Work Assignment No. 109
INTERVIEW NO. A-i
Schiegel Lining Technology: James Price TRW: Michael D. Powers
Inc., The Woodlands, TX Morris Jett Michael 1. Haro
Robert Clarke
Jan Brunri
713-350-1813
14 December 1982
Sumnia ry
• Schiegel is attempting to change the historically negative image of
synthetic liners by marketing a high quality, high technology product.
They offer a competitively priced product when viewed from a life-cycle
cost benefit analysis.
• Schiegel has demonstrated that it is possible to install a 100 percent
leak proof liner. There are several installations of double liner
containment with monitoring systems that have passed stringent long
term testing to ensure a 100 percent leak proof system.
• Schlegel controls and performs QA/QC, for all operations, from receipt
of raw polymer to installation.
• QA/QC procedures should be specified in regulations and include a re-
quirement for a third party QA/QC audit. Standards-setting organiza-
tions such as ASTM take too long to reach a concensus.
Background
Schiegel Lining Technology, Inc. is a subsidiary of Schiegel Corpora-
tion, a Rochester based company. Other lining divisions with manufacturing
capabilities are located in Hamburg, West Germany, and Waterford, Ireland.
Schlegel manufactures, tests, and installs high density polyethylene (HOPE)
liners in 60, 80, and 100 mil thicknesses.
The following are perspectives of the company on: (a) various aspects
of their operating philosophy; (b) installation procedures; (c) quality
assurance/quality control procedures; (d) warranties; (e) major causes of
liner failures; and (f) adequacy of regulations and regulatory reform needs.
The statements and assertions, which are largely qualitative, reflect the
extensive experience of the company; quantitative technical and engineering
data to support the statements and assertions were not provided.
4-3
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Interview No. A-i
Schiegel Lining Technology, Inc.
Page 2
Schiegel’s General Operating Philosophy
• Historically, the synthetic liner industry has a very negative image.
There are a lot of fly-by-night operators who do sloppy work, as well
as other more-or-less reputable firms whose products do not perform
satisfactorily.
• Schiegel is trying to change the negative image of the liner industry.
They put out a product that they regard as being high quality, high
technology, and consequently higher priced. They are not in the “thin
membrane” market; while some companies manufacture a 30, or even 20,
mu liner sheet, Schiegel ‘s material comes in 60, 80, and 100 mu
thicknesses.
• There often are problems with synthetic liner installation. A “total-
ly leak-proof” liner system is possible. Only when the most stringent
controls are exercised during design and installation can a system be
considered as 100 percent leak-proof. Post completion monitoring is
essential to establishing a totally leak-proof installation.
Schlegel continually strives to improve their practices in order to
achieve the leak-proof installation.
• Schiegel believes that because the regulations allow liners as thin as
30 mil, other manufacturers and installers have greater difficulty in
providing a leak-proof system. Physical properties such as tear and
puncture resistance are directly related to thickness and significant-
ly affect the liner installation by providing a factor of safety for
damage from external forces imposed on the liner.
• Although Schlegel’s first contact with a customer is usually through
a design or engineering consultant, the final contact is directly with
the end user of the liner in 95 percent of their business. In this
way, Schlegel is responsible only to the end user of the liner, rather
than to some contractor. Schiegel does advise the engineer and in-
fluence design, but it does not do any of the civil engineering work
for a facility, nor does it stamp plans for dirt work or piping.
• Schiegel carefully tests compatibility of the liner material with the
waste to be contained, working in close cooperation with the owner’s
design engineers. They run a high temperature immersion test at 1580F
(700C) for 28 days in the customer’s waste, or until the weight of the
sample stabilizes. Changes in weight and tensile strength are deter-
mined; weight changes greater than ± 3 percent and changes in tensile
properties greater than ± 10 percent indicate that the liner is dele-
teriously affected by the waste.
4-4
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Interview No. A-i
Schiegel Lining Technology, Inc.
Page 3
Schiegel’s Liner Installation Procedures
• All welding and QA/QC testing is performed by independent Schiegel per-
sonnel. Schiegel uses a year-round core group of welding technicians,
adding trainees as the need arises. The usual company crew consists
of a site superintendent, a senior welding technician, and three or
four other welding technicians. Non-welding laborers are hired local-
ly to perform such duties as unloading, cutting, and positioning the
liner sheeting, sand bagging it to prevent wind damage or movement,
and surface grinding in the areas to be welded.
• Usual procedure for installation is to position, cut, and prepare
liner surfaces during the day, and then do the actual welding at night
when the material has contracted.
• Because of the thickness of Schiegel’s material, heavy rubber-tired
equipment can work on top of the liner. This allows grading during
the placement of a soil cover. Schiegel does insist on having a
welding technician on-site to watch for punctures or other damage
during the placement of soil cover.
• Schiegel feels that their patented extrusion welding process is criti-
cal to the success of their liners. This process extrudes a ribbon of
molten HOPE between the liner sheets, and then pressure rollers force
the sheets together. This method of joining sheets results in a seam
with physical and chemical properties identical to that of the sheet
itself, as opposed to solvent or contact cement joints comon to other
materials.
Schiegel’s QA/QC Practices
• Schiegel tests each shipment of raw polymer prior to unloading; it is
unloaded only if it meets specifications.
• Ouring the manufacturing process, the sheeting is visually inspected
for flaws and holes; imperfections are marked and noted for repair in
the field.
• Field welds are tested in several ways:
- Visual.
— “Point-stress test apparatus”. A screwdriver is inserted and twisted
to see if a spot on a weld fails.
- Ultrasonic. Because Schlegel’s welds are designed to be homogeneous,
inhomogeneities such as gaps, bubbles, and holes in the welds are
easily detected.
— Vacuum box. For testing fillet welds.
4-5
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Interview No. A-i
Schiegel Lining Technology, Inc.
Page 4
- Tensile and peel strength. Samples are taken and tested in field
prior to welding. Post-installation samples are also sent to the
Schlegel Lab for confirmation testing.
• Schiegel is disturbed that some companies still do installation during
the winter. They refuse to do it except under the most controlled
conditions. This includes covering the entire installation and main-
taining adequate temperature ranges. They feel that welding cannot be
done when the ambient temperature is below 450F. If only the welding
temperature is raised to compensate (as opposed to raising the sheet
material temperature) the adjacent material can become crystallized
and significantly weakened.
Incorporation of QA/QC Requirements in Regulations
• Schlegel would like to see QA/QC procedures written into the regula-
tions. Because they put a lot of time and expense into QA/QC already,
regulatory requirements would not adversely affect them, but would in-
crease the expenses of others in the industry; this would help Schiegel
to reduce the cost advantage others presently enjoy. A third party
QA/QC audit should be made mandatory. Standards setting organizations
(e.g., ASTM) may take too long to reach a consensus, and may be in-
fluenced by certain portions of the industry.
• Because there are still a number of fly-by-night lining manufacturers
and installers, Schlegel feels that the licensing of installers has
merit. However, they also feel that such a program would be an admi-
nistrative nightmare, and impossible to carry out effectively.
• The industry does currently have adequate technology to test the inte-
grity of a synthetic liner system but improvements could be made to
improve the speed and accuracy of the testing procedures. Part of the
problem is in personnel training, both for installers and QA inspectors.
• Regulations should put a ban on liner installation during adverse
weather conditions.
Major Causes of Liner Failure
• Liners can fail for a variety of reasons, including the following:
- Failures at welds or seams.
- Punctures due to equipment or carelessness (e.g., workmen dropping
hot welding tips onto the liner and heavy equipment digging through
a soil cover into the liner).
- Incompatibility. This can cause failures at the weakest point.
Often times, the waste contains contaminants that were not specified
(e.g., oil wastes in a brine pond).
4-6
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Interview No. A-i
Schiegel Lining Technology, Inc.
Page 5
- Penetrations. This is Schiegel’s biggest problem. They try to have
piping passing through the liner made of HDPE, so that they can make
a direct bond. When pipes of other composition are used, they
sleeve the pipe with HDPE and use a closed-cell neoprene gasket
compressed by clamps. Stresses at penetrations may also induce me-
chanical failure of the liner sheeting unless proper design is in-
corporated into the system.
Warranties
• Schlegel gives a two-year warranty on material and workmanship; problems
uncovered during the warranty will be repaired or replaced. Schiegel
has had warranty repairs; where they have made mistakes, they have gone
back and fixed the problems. They try to eliminate them, but human
errors do occur.
• Schlegel has never had a waste/liner incompatibility failure. When the
waste is identifiable and tested prior to installation, failures can be
eliminated. After installation, problems can occur when different
wastes are entered into the basin. Schlegel will not attempt to sell a
liner where the waste is incompatible with the sheet material.
• There are many irresponsible warranties in the market. Many of the
twenty year (or longer) extended warranties are full of loop-holes and
worthless. Schlegel may offer an extended warranty if certain parame-
ters such as controls over operating conditions, security, waste con-
centration, etc., can be achieved and maintained.
Materials Supplied to TRW
The following “non-confidential” materials were supplied to TRW by
Schlegel during the interview:
• Schlegel Lining Technology, Inc. Evaluating Lining Materials. The
Woodlands, Texas. 1982. 13 pp.
• Schlegel Lining Technology, Inc. Test Procedure for Determining
Chemical Resistance of Flexible Membrane Liners. 2 December 1980.
3 pp.
• Schlegel Lining Technology, Inc., The Woodlands, Texas. (Company lite-
rature and related technical data on Schlegel liner applications,
flexible membrane properties, and design and installation details.)
Approximately 100 pp.
In addition, Schlegel has agreed to forward copies of certain proprie-
tary technical data upon receipt of a confidentiality agreement signed by
TRW. Because of the schedule constraints for the project, however, it was
decided at this time to avoid the often lengthy process of drafting and
signing a mutually agreeable secrecy agreement.
4-7
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ASSESSMENT OF TECHNOLOGY FOR CONSTRUCTING AND
INSTALLING COVER AND BOTTOM LINER SYSTEMS
FOR HAZARDOUS WASTE FACILITIES
EPA Contract No. 68-02-3174; Work Assignment No. 109
INTERVIEW NO. A-2
Sta-Flex Corporation: Louis Peloquin TRW: Louis L. Scinto
San Jose, CA 408-224-0604
14 December 1982
Surnma ry
• The performance of a properly selected, designed, and installed FML will
exceed that of a clay liner over the long term.
• Most liner failures can be traced back to improper design or inadequate
design specifications.
• Each liner material has different installation requirements; therefore,
any installation standards must be written to be material-specific.
• Installers should be responsible for quality control during liner instal-
lation. Inattention to recommended installation and quality control pro-
cedures by inexperienced installers (particularly general “dirt contrac-
tors) can lead to serious deficiencies in the quality of the job and
increases the probability of liner failure.
• Locational standards for hazardous waste facilities should be adopted to
restrict siting of these facilities in environmentally sensitive areas.
Background
Sta-Flex Corporation is a well-known installer of flexible membrane
liners (FML), headquartered in Greenland, NH; Mr. Peloquin is in charge of the
West Coast Office in San Jose, CA. The company was founded in 1970. Mr.
Peloquin joined the firm in 1977. Prior to that time, he had been with Burke
Rubber Co. and was in charge of engineering, manufacturing, marketing, sales,
and installation of Hypalon for the company. Sta-Flex employs four full-time
superintendents and four foremen who travel between job sites supervising
installation work. Local labor is employed at each project, but only to per-
form such manual labor as positioning sheets of liner material. Seams are
all done by experienced Sta-Flex personnel. The company will install most
liner materials, but the majority of their experience has been with Hypalon,
and more recently HOPE.
The following are the perspectives of Sta-Flex Corporation (as conveyed
by Mr. Peloquin to TRW) on: (a) long—term performances of clay vs. flexible
membrane liners (FML); (b) design considerations; (c) FML installation prac-
tices; (d) quality control and testing requirements; (e) standards and regula-
tory reforms; and (f) miscellaneous considerations including contacts for
additional data. 4—8
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Interview No. A-2
Sta-fl ex Corporation
Page 2
Performance of Clay vs. Synthetic Liners
• If properly selected to be compatible with the waste contained and de-
signed and installed properly, FML will outperform clay in the long run.
The Bureau of Reclamation has a lot of information on the compatibility
of clays with wastes which basically shows clay is only good over the
long term to contain fresh water.
Design Considerations for Flexible Membrane Liners
• Some failures of FML can be related to installation problems, e.g., in-
adequate seams. However, most of the failures can be related directly
or indirectly to improper design and/or inadequate design specifications.
• Proper design, including siting, can prevent many potential problems such
as chemical attack of the liner material by the waste, and generation of
gas under the liner and subsequent formation of “bubbles” in the liner.
One example of a failure which resulted from improper design was a lined
pond constructed at a Scott Paper mill in Wisconsin in the early 1970’s.
The lined pond was built directly over an older unlined pond site which
had contained organic sludges. The pond was designed and constructed
with a flat bottom. Gas was generated under the liner from the residual
organics in the subsoil, causing large gas bubbles in the liner. The
design should have incorporated a slightly sloped bottom with vents on
the slopes for gas.
• One aspect of a proper design is selecting a liner material that is com-
patible with the waste to be contained, and that will resist degradation
due to weathering. Most membrane liners show good weatherability (with
the exception of PVC which degrades when exposed to ultraviolet light and,
therefore, must be covered with earth). Large differences between mate-
rials in terms of their weatherability do not usually exist. However, in
designing a lined disposal facility, compatibility tests must be run to
determine the suitability of the membrane for the specific application.
Some weatherability and compatibility data can be extrapolated from the
use of certain liner materials (e.g., PVC) in other applications such as
piping. Data on specific materials and wastes are usually developed by
liner manufacturers.
• Failures due to chemical attack are not widespread occurrences. Sometimes
the introduction of an unexpected waste constituent or a large quantity
of a normal trace constituent into a lined disposal facility can cause
problems due to chemical interactions between the waste and the liner.
Such a condition, however, may not necessarily lead to liner failure. For
example, a Hypalon liner installed in a pond operated by Buckeye Cellulose
in Perry, Florida, was subjected to higher than expected concentrations of
oil which caused swelling and bubbling of the liner. After draining the
pond, removing the oil, and drying the liner in the sun, the swelling sub-
sided. No permanent damage to the liner was experienced. Thus, some
potential damage to liners due to waste variations or incompatible wastes
may be reversible.
4-9
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Interview No. A—2
Sta-flex Corporation
Page 3
• Structural design of the waste facility has a lot to do with the final
success or failure of the liner. Slopes should not be too steep (2:1 is
about the limit, 3:1 is preferred for most FML). Soil should be proper-
ly and uniformly compacted. Geotextiles should be considered if rocks
are likely to be a problem in the finished subgrade. Penetrations of the
liner, such as for inlet/outlet structures, should be minimized and care
should be taken in specifying proper methods of installing liners around
these penetrations.
• Designing a lined facility to use two or more different liner materials
is a mistake. Seams between different materials are not as strong as
between two pieces of the same type of material. Seams can be made
where no other solution exists, but should be avoided if possible.
Installation Practices
• Subgrade preparation is important. It is hard to define an “acceptabl&’
surface quantitatively. The decision whether or not to accept a prepared
subyrade prior to placement of FML should be left to the installer to
make, based on his experience.
• Each liner material installer has different techniques which are used for
seaming. Even for the same material , different manufacturers may recom-
mend slightly different seaming methods.
• Seams in HOPE are done exclusively by heat welding (as opposed to Hypalon
for which bodied solvent adhesives are commonly used). Hot air, hot
wedge, or hot melt (extrudate) systems are used. One type of seaming
method uses a hot wedge to make a double seam in the liner with an air
pocket between the seams. Testing of these seams is performed by in-
jecting 60 psi compressed air into the space between the seams, waiting
10 minutes, and checking for leaks or drops in pressure. Such a technique
can be used both during installation and later when the facility is in
operation. Care must be taken in seaming HDPE to prevent crystallization
in the seam. Crystallization weakens the seam by making it susceptible
to flex cracking. Since HOPE expands and contracts quite a bit with
changes in temperature, stress cracking at crystallized seams could be
a problem, particularly on parts of the liner which are exposed to the
elements.
Quality control and Testing
• Quality control is an essential part of all installations. Tests with
such devices as the air lance, vacuum box, spark testers (not applicable
for some Hypalons), or ultrasonic testers should be done by the installer.
• A big concern of installation contractors such as Sta—Flex, which specia-
lize in installation of FML, is that general contractors which have little
or no experience installing FML will win contracts by bidding low and will
4-10
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Interview No. A-2
Sta-flex Corporation
Page 4
not be able to do an adequate job. This will give specific products and/
or the entire industry a bad name. The opportunity for big profits has
lured a number of general contractors into buying liner material off the
shelf, and installing the material without consulting with the manufac-
turer on recommended installation and quality control practices, or ob-
taining test data on compatibility. This can lead to problems with or
failure of the liner. Solutions to this problem might be to have all
manufacturers approve fabricators and installation contractors before
selling them materials or to better educate design engineers in the pre-
paration of detailed specifications for installation contractors to
follow.
• Properties of liner materials affect seam strength. For example, re-
inforced membranes with 6 x 6 scrim form stronger seams than the same
material with 10 x 10 scrim. The 6 x 6 scrim provides greater strike
through, allowing more surface area for bonding between the two materials,
with only a slight reduction in tear resistance compared to 10 x 10.
Peel strength of a seam is often as important as (and may be totally un-
related to) shear strength. Many seanis turn out like adhesive bandages;
they are very easy to peel apart but very difficult to shear. As for
properties of the liner material itself, elongation and tear are better
indicators of suitability than tensile strength, because the ability to
elongate (e.g., due to local subsidence of the subgrade) is what makes
flexible liners useful in pollution control applications.
Standards and Regulatory Reforms
• NSF’s proposed standards may suffer because the range of inputs used to
develop the standards was not broad enough. In order to set good stan-
dards input needs to be obtained from a variety of sources.
• The major problem with setting standards for FML is that it is difficult
or impossible to imagine a standard generally applicable to all types of
materials. Individual standards for each material , covering specifica-
tions and installation procedures, may be worth considering.
• There should be restrictions on location of hazardous waste disposal
facilities to mitigate environmental damage in the event of liner failure
because there can never be total assurance of 100 percent containment of
wastes in man-made structures.
Miscellaneous, Including Additional Contacts
• A potentially popular new material for liners is linear low density poly-
ethylene.
• The polyethylenes such as HOPE will be a dominant factor in the liner
market.
4-11
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Interview No. A-2
Sta-flex Corporation
Page 5
u A leachate detection system purported to be capable of locating leaks
is being used at a solar brine pond in Nevada. It is part of the State
Public Works Board’s Playa Project in Boulder City. Don Day is the
Project Manager. Copper wires intersect in a grid pattern of 6 foot
squares under the pond. Any leaks from the pond can be detected as
short circuits in the grid. This technique is only applicable in a
limited number of cases (e.g., where shallow groundwater would not
trigger the short circuit).
• Research on compatibility of polyethylene resins with various materials
is done by Clark Gunness in Canton, Massachusetts, for liner manufac-
turers like Sarnafil. Mr. Gunness can be reached at 617-828-5400.
4-12
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ASSESSMENT OF TECHNOLOGY FOR CONSTRUCTING AND
INSTALLING COVER AND BOTTOM LINER SYSTEMS
FOR HAZARDOUS WASTE FACILITIES
EPA Contract No. 68-02-3174; Work Assignment No. 109
INTERVIEW NO. A-3
Burke Rubber Company: D. Kutnewsky TRW: Louis L. Scinto
San Jose, CA Ralph Woodley
408—297-3500
16 December 1982
Summary
• The best way to assure the quality of a liner installation is to adopt
a systems approach, where there is an unbroken chain of responsibility
for quality assurance/quality control (QA/QC) from designer to manu-
facturer to fabricator to installer to operator.
• Pinholes can be present in any single ply membrane and the manufactu-
rers of single ply materials are hard put to guarantee a pinhole-free
product.
• The amount of weepage through pinholes would be orders of magnitude
less than through a bad seam or a substantial tear. The puncture re-
sistance of most materials is sufficient to prevent enlargement of
pinholes under most circumstances.
• Both non-destructive in-place testing and testing of random samples
cut from the finished liner should be performed to test the quality of
field seams.
• It is difficult or impossible to define the quantitative effects that
deviations from recommended installation practices have on liner per-
formance.
• Liner warranties cover material quality, workmanship, and “normal
weathering”. Damage resulting from exposure of the liner to harmful
chemicals is excluded from the warranty.
• Tensile strength alone is insufficient to characterize the performance
of reinforced synthetic membrane liners. The relationship between
tensile strength and elongation defines an important property of a
liner material, its “tensile performance factor”, or “work-to-break”
as defined in ASTM D-885.
4-13
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Interview No. A-3
Burke Rubber Company
Page 2
Background
Burke Rubber is a major manufacturer and fabricator of synthetic liner
materials. The company has done some installation work through a subsidiary,
Burkeline Construction Company; however, most installations of Burke material
are done by independent, specialty contractors approved by the company.
Burke will only sell material to approved contractors, or to firms which
agree to allow a Burke supervisor on-site to oversee the installation and
provide technical assistance.
Discussions with Burke personnel encompassed primarily the following
areas: (a) general aspects of QA/QC requirements for flexible membranes;
(b) QA/QC during liner installation; (c) sources, significance, and control
of pinholes in flexible membranes; (d) construction/installation specifica-
tions; and (e) liner warranties. Outcomes of discussions of these topics
are summarized below.
General Aspects of QA/QC Requirements for Flexible Membranes
• The best way to assure quality is to use a systems approach. •Burke
attempts to do this by requiring a continuity of control through all
stages of the project: design, manufacturing, fabrication, and installa-
tion. By exerting direct control or providing technical assistance
during all stages of the project, the manufacturer is the master link
in an unbroken chain of responsibility for quality assurance. For the
installation stage of the project, control is maintained through either
direct supervision of the work by Burke personnel , or by use of contrac-
tors approved by Burke who have proven their qualifications by receiving
on-site training by the manufacturer in the installation of at least
250,000 square feet of the material being used.
• Responsibilities for QA should be clearly delineated. The design engineer
should be responsible for ensuring that waste/liner compatibility is con-
sidered and that the impoundment is properly designed and sited. The
manufacturer should ensure that the material meets or exceeds its speci-
fications. QA/QC for factory seams is the responsibility of the fabrica-
tor. The installation contractor has the job of ensuring that earthwork
and field seaming are done properly and that the liner is not damaged
during installation. The owner’s responsibility for QA/QC during instal-
lation should be to define the overall QA/QC program, incorporating a
level of detail that is consistent with the waste being contained and the
location of the facility*.
*FOr example, some facilities may require greater attention to QA/QC than
others because they will contain a highly toxic and mobile constituents
which, if the liner were to fail, could migrate from the facility and ad-
versely affect human health or the environment.
4-14
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Interview No. A—3
Burke Rubber Company
Page 3
• In reviewing bids for lining jobs, operators must realize the importance
of QA/QC and that this necessary aspect of the job has costs associated
with it. Price should not be the only consideration in selecting an
installer.
QA/QC During Installation
• Some form of certification for liner installers is necessary. One means
of certification would be for manufacturers to approve installation
contractors (this is the approach taken by Burke). Licensing of in-
stallation contractors (e.g., by EPA using some type of standard) might
not be sufficient to maintain the continuity of control which is so
important in QA. Such an approach, in combination with requirements
that the installer post a surety bond against installation-related
failures, may provide more assurance that the job will be done properly,
since there would be a financial incentive for the installer to perform
adequate QA/QC.
• Quality control testing of field seams by the installation contractor
should include both non-destructive testing of 100 percent of the field
seams (e.g., using an air lance) and testing of samples of field seams
cut from the finished liner at random for shear testing, per specifica-
tions. If non-specification seams are detected by either method,
further testing of the same kind should be done in both directions to
the point where the seam again meets specification requirements; and
then a cap strip should be placed over the suspect seam between the
tested acceptable points and seamed using standard seaming methods
(applied with extra care). The same basic methods would apply to test-
ing of factory seams by the fabricator.
• The air lance method of QC testing of field seams has fewer disadvan-
tages than tests such as the vacuum box or ultrasonic measurements.
The vacuum box method is not as reliable for thin, flexible materials
as it is for thick, stiff materials. Temperature and humidity varia-
tions can affect the reliability of ultrasonic methods.
• It would be difficult, if not impossible, to develop a single Q 1 4/QC
procedure applicable to all flexible membrane liner installations.
Sources, Significance, and Control of Pinholes in Flexible Liners
• Pinholes can be present in any single ply membrane. The largest of
these may be visible to the naked eye or may be spotted by passing
the liner over a light bar; the smallest may be a few microns in dia-
meter. Pinholes in a single ply can originate during the calendering
or extrusion process where air bubbles, raw material contaminants, or
poorly dispersed granules (e.g., undispersed carbon black) in the
mixed stock can pass through, or nearly through, the single ply.
4-15
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Interview No. A-3
Burke Rubber Company
Page 4
Quality control during manufacturing may include fine screening of
the mixed stock before calendering or extrusion. Post-manufacturing
QC can consist of merely visual inspection of the finished liner on
both sides (usually during fabrication) and patching of any holes
that are found.
• Pinholes which penetrate the liner are less of, a problem for multi-ply
liners (such as most Hypalon) because the chances of a pinhole in one
ply matching up with another pinhole in a second ply are very small.
The only potential problem is if a pinhole exposes scrim such that
contact with waste fluids could cause wicking along the scrim to a
pinhole in the opposite ply, or build-up of fluid between plies and
eventual delamination. The probability of this happening is greatest
for tightly-woven scrims and thick yarns (e.g., 10 x 10 - 1000 denier),
but in any case is small.
• Any single ply material is very difficult to manufacture completely
free of pinholes. Most lining materials possess sufficient puncture
resistance to minimize significant pinhole enlargement. In multiple—
ply construction, the amount of weepage through pinholes would proba-
bly be orders of magnitude less than through a bad seam or a substan-
tial tear or delamination.
• Burke multi-ply membrane materials are specified as “pinhole-free”.
Some manufacturers of thin single-ply liner membranes include a
maximum allowable pinhole count. NSF did not include a pinhole count
as a standard for thinner plies of single-ply membranes for liners
used for waste containment.
Construction/Installation Specifications
• Burke provides detailed procedural instructions in its company litera-
ture for field seaming of Burke membrane lining materials. Bonded
seam strength and shear must meet the specification requirements for
both factory and field seams. These specification requirements for
installation represent the best methods known to ensure that liners
are installed properly, but a low bond seam may not significantly
affect liner performance. If a failure occurs, the impoundment must
be emptied and the point of leakage inspected to determine the cause
of failure. The responsibility for repairs is usually indicated by
the type of failure. A factory seam failure is the responsibility of
the fabricator; a field seam failure is the responsibility of the
installing contractor; and a mechanical failure due to damage follow-
ing installation is the responsibility of the owner.
• Burke specifications recommend the use of optimum size factory seamed
panels to minimize field seaming and time of installation. It is
important to minimize installation time to decrease the probability
of inclement weather adversely affecting the condition of the subgrade.
4-16
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Interview No. A-3
Burke Rubber Company
Page 5
• Thermal expansion and contraction of some liner materials must be
considered to avoid undue stress on the seams. Materials with high
rates of thermal expansion and thick cross-section are sometimes
seamed at night to minimize the effects of contraction. Sandbagging
the edges of panels during field installation also prevents the ten-
dency of some membranes to shrink in an unrestrained state. Some
materials require excess wrinkles to allow for shrinkage caused by
reduction in mass.
Warranties
• Burke generally provides a limited warranty for its Hypalon liners
and covers. The warranty is only valid if installation is supervised
by Burke or is done by an approved installer. The warranty guarantees:
(a) that the material will be free from manufacturing defects in work-
manship or materials for one year, and (b) that the membrane will not
develop cracks/holes which penetrate the liner due to the effects of
“normal weathering” for 20 years.
• Fitness for use (i.e., compatibility of the liner and waste) is not
specifically covered by most limited warranties. Effluent imersion
testing is often conducted by the manufacturer of the liner material
to indicate the effects of a specific effluent on a specific lining
material as a service to the end user.
• Requests are growing for manufacturers to extend current warranties
for certain types of installation. One possible solution might be to
increase the material cost per square foot for each incremental exten-
sion of the warranty beyond normal limits.
Miscellaneous
• Installation procedures for landfill closure covers is essentially
the same as for liners.
• Leak detection systems are sometimes installed under liners to collect
and identify leakage. As an impoundment is filled, the compression of
the soil below the liner can squeeze liquid out of the compressed
soil. This can show up as an apparent leak in the liner, and the
“de-watering” may show up in the leakage monitoring system for a
period of time. Care should be exercised to determine that the liquid
appearing in the leak detection system comes from the impoundment
rather than the compressed subgrade material.
• Burke has studied the effects of fabric reinforcement on tensile pro-
perties of its Hypalon products, and has developed a means of charac-
terizing a material’s ability to absorb deformation forces through
4-17
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Interview No. A-3
Burke Rubber Company
Page 6
its strength and conformational properties. Data from measurements
of tensile properties (ASIM D751-Grab Method) provide the basis for
defining the “tensile performance factor” of a material. This factor
is equal to the area under the Load/Elongation curve (referred to in
ASTM D885 as “work-to-break”) and gives a value (in inch-pounds) that
relates the energy absorbed by the liner before it ruptures. Burke
data for reinforced Hypalon of different scrirn sizes show that while
breaking strength increases with finer scrim weaves (e.g., 10 x 10
>6 x 6), elongation at break decreases. The effect of reduced elon-
gation is greater than the effect of increased breaking strength,
such that the reduced elongation accompanying the more tightly woven
high-strength fabric accounts for a lower overall tensile performance
factor. Thus, tensile strength alone, as measured by breaking strength
of the reinforcing fabric, does not represent the total tensile per-
formance capability of a fabric-reinforced membrane liner. Since
tensile performance (e.g., the ability to bridge gaps in the sub-
surface due to subsidence or sink holes) is such an important property
of a liner, elongation to the point of rupture must also be tested to
determine optimum performance. A carefully considered balance of
properties should be considered by the design engineer in determining
the choice of flexible membrane liners.
4-18
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ASSESSMENT OF TECHNOLOGY FOR CONSTRUCTING AND
INSTALLING COVER AND BOTTOM LINER SYSTEMS
FOR HAZARDOUS WASTE FACILITIES
EPA Contract No. 68-02-3174; Work Assignment No. 109
INTERVIEW NO. A-4
Gundle Lining Systems, mc: Dr. Richard K. Schmidt TRW: Michael T. Haro
Houston, TX 713-443-8564 Michael D. Powers
17 December 1982
Summary
• The major problems/concerns with flexible membrane liner installation
are as follows: (a) extremes of temperatures; (b) a wet job site; (c)
high wind conditions; and (d) cross joint and T—joint seaming (seaming
areas where 3 or 4 sheets come together).
• Quality assurance/quality control guidelines for both installing and
manufacturing of flexible membrane liners should be added to the regula-
tions, as well as QA auditor program for liner installation.
• Flexible membrane liner customers must be aware of all the factors
which affect the quality of the final product, including liner mate-
rial and compatibility, seam quality, and financial condition of the
manufacturer.
• Forcing manufacturers to warranty flexible membrane liners for the
life of the facility is not practical because: (a) warranties are
only as good as the financial strength of the company that provides
them; (b) in most cases, companies take exception to incidental and
consequential damages which could occur as a result of failure; and
(c) companies attempt to limit their liability to a dollar amount
which does not exceed the selling price of a particular job. Warran-
ties for synthetics should be comparable to those required for clay
liners.
• It is important that qualified, experienced flexible membrane liner
contractors be used to install liner material. This is a specialized
business, and should not be left to a general contractor who has no
liner installation experience. The best installation can be obtained
when a qualified licensed contractor is used in conjunction with a
quality control technician from the liner manufacturer.
Background
Gundle Lining Systems Inc. is a manufacturer of the following flexible
membrane liners: high density polyethylene (HDPE), elastomeric polyolefin
alloy based HOPE, ethylene vinyl acetate co-polymer, and co-polymer low den-
sity polyethylene. Over the past 20 years, the company has installed over
4-19
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Interview No. A-4
Gundle Lining Systems Inc.
P age 2
50 million square feet of liners and covers worldwide. Gundle produces a
22-1/2 foot wide, totally seamless roll of HOPE that ranges in thickness
from 20 to 100 mils. The company subcontracts with about 6 licensed instal-
lers that are trained by Gundle. The company also subcontracts the earthwork
construction and has a representative on site to ensure quality.
Presented below are the perspectives and recommendations of the company
on the following: (a) specifications and quality assurance/quality control
(QA/QC) of liner manufacturer; (b) warranties; and (c) installation and field
QA/QC. The statements and assertions, which are largely qualitative, reflect
the extensive experience of the company; quantitative technical data on HOPE
physical properties and chemical resistance were provided.
Specifications and QA/QC of Manufacturer
• Liner manufacturers should be required to certify their products almost
to the point of “finger printing”. A common problem in the industry is
when a company shows prospective customers high quality material, but
actually delivers low-grade material. For example, in order to qualify
for the Hypalon trade name, the liner material is only required to be
40 percent Dupont polymer. Other materials that are used in the liner
vary from company to company and, therefore, the liner specifications
will also vary.
• Flexible membrane liner customers need to take cognizance of the total
quality of the product they are purchasing. Many customers emphasize
the quality of the material, but ignore seam quality or the financial
stability of the manufacturer. Overall, the industry needs a better
educated customer.
• Quality control in all phases of the process is essential to a secure
containment system. Quality control starts with the raw materials. Out
of hundreds of polyethylene formulations tested, Gundle uses only 3 types
of resins to make their 97.5 percent pure HDPE liner. The quality con-
trol procedure used is as follows:
- Raw material received from each rail car is sampled top and bottom.
A screening analysis is performed on each resin sample in the labora-
tory. The material is unloaded into the storage silos only if it
passes the screening analysis tests.
- Visual inspection of the liner material occurs as the liner rolls off
the machine. Samples of each roll are taken twice a shift for labora-
tory analysis. Gundle will not ship out a roll of material that does
not pass the laboratory tests.
- Each roll is batch-coded, date-coded, and numbered before being shipped
to the field.
- A quality control certificate is provided to the customer documenting
the approval of the liner material according to specifications.
4-20
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Interview No. A-4
Gundle Lining Systems Inc.
Page 3
• Immersion tests should be carried out at the design stage of the pro-
ject in order to confirm waste-liner compatibility. Gundle uses a
90-day room temperature imersion test with the customer’s wastes on
both sheets and seams. Tests at higher temperatures are performed if
the liner will be subject to higher temperatures in the disposal envi-
ronment.
• Price is extremely important in the liner industry market. Municipa-
lities are notorious for compromising on liner quality for lower
prices.
Warranties
• The strength of an individual warranty is only as good as the financial
strength of the company providing them. In general , most companies
limit their warranty to the actual product that they are supplying and
in most cases take exception to incidental and consequential damages
which could occur as a result of failure. Further, they attempt to
limit their liability to a dollar amount which does not exceed the
selling price of a particular project. No company wishes to take on a
warranty liability which can far exceed the revenue that would generate
from a specific project. Warranties for synthetic liners should be
comparable to those required for clay liners. In general, most respon-
sible companies will readily live up to the terms of their warranty
agreement.
• Because of the July 1982 regulations, customers will soon ask for 30-year
warranties. Typically, there are companies that will give a 30-year
warranty, but realistically, they are worthless because the companies
that give them are small, under-capitalized firms. Most 30—year warran-
ties will probably be around a lot longer than the companies that pro-
vided them.
• Gundle provides a 20-year weathering warranty for their liner. The com-
pany guarantees the liner will serve its intended purpose for 20 years.
The warranty excludes physical or mechanical damage caused by the cus-
tomer, acts of God, and chemical incompatibilities other than those which
have been certified. Normally, the company limits the value of the
warranty to the selling price of the project. (The licensed installers
for Gundle also provide a 2—year workmanship warranty on liner installa-
tion.)
• Gundle has contacted many insurance companies. For 2 to 3 percent of
Gundle’s annual sales, these companies would be willing to provide Gundle
with coverage, but they will not insure individual jobs.
4-21
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Interview No. A-4
Gundle Lining Systems Inc.
Page 4
Installation and Field QA/QC
• The major problems with flexible membrane liner installation are as
follows: (a) extremes of temperatures; (b) a wet job site; Cc) high wind
weather; and (d) cross—joint and T-joint seams (seams of 3 or 4 liner
sheets).
• EPA should provide quality assurance guidelines in the regulations for
both the installer and manufacturer. Less than 5 percent of the hazardous
waste facility operators check on the liner material used or workmanship
of the installer once the liner has been placed in the field.
• EPA should also provide a third party QA auditor requirement in the regu-
lations for liner installation. A third party auditor is not necessary
for the manufacturer; instead, have the customer (operator) perform
their own immersion and physical property tests on the prospective liner
material to ensure quality.
• Gundle’s field installation and quality control procedures are as follows:
- To ensure an adequate containment system, the subgrade must be firm
and void of debris or sharp angular rocks.
— The installation begins in the morning with a test weld to ensure good
seaming technique. The installer uses Gundle’s patented fusion/ex-
trusion welding process that mixes liner sheets with extrudate. Because
proper welding temperature is very important, the installer double
checks the weld temperature with a hand held pyrometer.
- Preparation of the area to be welded is also important. The installer
will double tape liner sheets together to avoid too much slack in the
sheets (a condition that results in “fish mouths”). The sheet surfaces
are cleaned by grinding; then the sheets are welded together.
- Gundle’s QC technician will visually inspect seams and questionable
areas will be marked for repair. The final control checks on seams
are performed with vacuum box tester and a field tensiometer. (More
and more clients are requesting 100 percent vacuum testing of seams.)
— Gundle’s QC technician has unilateral authority to shut down the in-
staller in bad weather. When day—time temperatures rise above 950F,
they will work at night. They will work in temperatures as low as 25SF
as lonci as there is no wind.
• Gundle asserts that the benefits of subcontracting licensed installers are
greater than those incurred by installing liners themselves. Gundle’s
installers have been in the business for 5 to 10 years and have relatively
stable work forces and local geographical experience.
4-22
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ASSESSMENT OF TECHNOLOGY FOR CONSTRUCTING AND
INSTALLING COVER AND BOTTOM LINER SYSTEMS
FOR HAZARDOUS WASTE FACILITIES
EPA Contract No. 68-02-3174; Work Assignment No. 109
INTERVIEW NO. A-5
Watersaver Company, Inc.: Bill Slifer TRW: Heather White
Denver, CO Jim Bryan
303-623-4111
17 December 1982
Summary
• Quality assurance/quality control procedures must be followed throughout
the manufacturing process as well as during installation of the flexible
membrane liner or cover.
• The July 1982 regulations are reasonable because they recognize that
clay has not proved effective in containing certain wastes.
• Quality assurance/quality control requirements and installation contrac-
tor requirements should be added to the regulations.
• Installation procedures should not be specified in the regulations because
each facility is different and may require that unique installation
methods be used.
• Liner designs that incorporate both clay and synthetic materials are
particularly good because they provide the assurance of both.
• Solvent and dielectric seaming methods are preferable to hot air seam-
ing methods (where applicable to the particular type of liner) for
factory fabrication of liners.
• A solvent bodied adhesive (at least 10 parts solids) is a superior
method to any other type of seaming system in the field, since changing
weather and temperatures affect working conditions. Seam quality is
more consistent no matter what material is used. Visual inspection can
be used to spot field seaming problems.
• Destructive testing of solvent seams is unwarranted because visual in-
spection by experienced QA/QC personnel can ensure at least gg percent
seam integrity. Moreover, destructive tests are inappropriate because
the cutting and seaming allows more chances for failure. Some destruc-
tive testing with representative samples seamed under the same instal-
lation (weather) conditions should be required.
4-23
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Interview No. A-5
Watersaver Company, Inc.
Page 2
Background
Watersaver Co. is a fabricator of synthetic membrane liners and covers.
The company has been in business since 1953 and has sold over 300,000,000
square feet of liners worldwide. They do some installation work on occasion
but prefer to concentrate on fabrication. Watersaver Co. is a proponent of a
systems approach to liner and cover design, construction, and installation.
They believe that ignorance in any area is the primary cause of liner failure
and that the experience of the designer, manufacturer, fabricator, installer,
and lab and quality control personnel is vital to the success of the liner
system.
The following are perspectives of the company on: (a) various aspects
of liner and cap design and installation; (b) quality assurance/quality control
requirements; (c) standards and warranties; (d) adequacy of regulations and
regulatory reform needs; and (e) research needs. Listing of additional sug-
gested contacts and data sources are also provided. The statements and
assertions, which are largely qualitative, reflect the extensive experience of
the company; quantitative technical and engineering data to support the state-
ments and assertions were not provided.
Design Considerations for Liners
• During the design phase, the long-term use of the site must be considered.
The site owner/operator must be very specific regarding the types and
quantities of wastes to be disposed in the facility so that the designer
and manufacturer may recommend the best possible liner system.
• Designs that incorporate both clay and synthetic liners are particularly
good because they provide the assurance of both materials. In addition,
the clay serves to protect the primary synthetic liner.
• Solvent seaming systems (used with CPE, PVC, Hypalon, etc.) are more
dependable than heat seaming systems (used with HOPE and similar type of
materials) because the quality of the seam is more consistent and can
easily be inspected visually. The temperature at which solvent seaming
takes place influences the time it takes the solvent to take effect, not
the ability of the seaming process to work at all as with heat seaming
methods. Because of this solvent systems seam faster and are not as de-
pendent on weather conditions as heat seaming methods.
Construction and Installation Considerations for Liners
• For large or complex facilities (e.g., facilities with many structures to
which the liner must be sealed), it is best to work with an installer who
specializes in flexible membrane liner installation. He should have
installed many types of facilities in many geographical areas. Possible
minimum qualifications might be fifty jobs in five years for a total of
five to ten million square feet of liner material installed.
4-24
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Interview No. A-5
Watersaver Company, Inc.
Page 3
• For small, simple jobs (earthwork and some sednling), a general contractor
may carry out the installation work. Someone with experience in field
installation of flexible membrane liners should, however, be on hand to
guide the contractor and to thoroughly inspect all aspects of the construc-
tion.
• Subgrade preparation is particularly important to liner performance.
Smoothing the subgrade with a vibratory roller is preferable to simply
spreading a layer of sand over the subgrade. The use of black liner
material is preferable because the heat absorbed by the liner brings soil
moisture to the surface. This softens the subgrade and reduces the chances
of puncturing the liner with the subgrade material.
• The weight of a roll of liner material is a major factor in determining
the size of the roll. 4000 pounds have been found to be the maximum
convenient size for field equipment and personnel to work with.
• No equipment should be driven across any type of synthetic liner, no
matter how thick. To provide a good safety margin, soil lifts should be
at least twelve inches deep.
Caps vs. Liners Requirements
• The cap on a landfill is very important because it prevents liquid from
accummulating and exerting pressure on the liner system. A minimum cap
grade of 2% may prevent surface runoff from exerting pressure on the cap.
“Hounding” may be an option to encourage drainage from larger areas.
• Waste resistance is not as important for cap selection because the cap
will not be in direct contact with the waste. However, factors such as
weatherability and strength may be more important for a cap than for a
liner. The cap and liner must be designed as a system to ensure compati-
bility for field seaming, if required.
• Subgrade preparation is even more important for cap installation than for
liner installation. Good compaction is necessary to prevent later sub-
sidence and possible damage to the cap.
• Caps are much easier to repair in case of damage (e.g., due to subsidence)
because they are above the waste.
Quality Assurance/Quality Control
• Quality control begins with the liner manufacturer. They must have per-
formed research to back up their materials formulations. They should have
their own government-approved laboratories capable of performing certified
tests. They should have tested their products with a variety of effluents.
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Interview No. A-5
Watersaver Company, Inc.
Page 4
• It is advantageous to have the design engineer at the site during cons-
truction to ensure the design is followed. This is particularly valuable
for large, complex facilities.
• Upon request by the customer, Watersaver will send a technical service
representative (TSR) to the construction site. These TSRs are full-time
Watersaver employees with good training and field experience. The TSR
instructs the construction contractor in proper field techniques for the
particular liner system and weather conditions, and performs QA/QC acti-
vities (e.g., seam inspection, etc.).
• Watersaver has had very few problems in working with general contractors
on small jobs. In general, they are eager to do a good quality job and
to cooperate with and learn from the TSR. For small jobs, having an ex-
perienced TSR who can teach the contractor exactly what to do is more
important than the experience of the contractor with flexible membranes.
• Destructive testing of solvent seams is unwarranted because visual in-
pection by experienced QA/QC personnel can ensure at least 99 percent
seam integrity. Moreover, destructive tests are inappropriate because
the cutting and seaming allows more chances for failure. Some destruc-
tive testing with representative samples seamed under the same instal-
lation (weather) conditions should be required.
Standards and Warranties
• Mr. Slifer has been involved with NSF’s standards comittee for synthetic
liners and on AWWA’s committee for developing a manual of recommendations
for liners and floating covers.
• A standard is not believed to be necessary because the liner industry is
so small and specialized. There is no one liner that will work for all
conditions, and giving any or all types of liners the NSF seal of approval
will not change that fact. (A national standard cannot be written that
excludes any company which wants to be included.) Each liner must be
chosen specifically for the waste and environment that it will be subjected
to.
• The materials standards under consideration by NSF’s committee are only
a half-way step toward assuring liner quality. The only control occurs
at the manufacturer’s and fabricator’s plant with no assurance of per-
formance. After that, there are still many opportunities for liner
quality to be compromised (e.g., during installation).
• Standard warranties cover only normal weathering processes. They do not
warranty against contact with harmful chemicals, acts of God., etc.
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Interview No. A-5
Watersaver Company, Inc.
Page 5
• A rider can be added to the standard warranty. It may ensure the liner
against damages due to the specific chemicals and concentrations thereof
that the liner is designed for. It may also specify that the warranty
is only valid if the facility is capped within one year, etc.
• Watersaver’s standard warranty states that their fabricated seams will
last as long as the liner does. In other words, if the liner manufac-
turer guarantees the liner for five years, Watersaver’s seams are gua-
ranteed for five years.
Perspectives on Regulations and Regulatory Reform Needs
• The July 1982 regulations are reasonable because they address the fact
that clay has not proved effective in combination with certain wastes.
• Other good aspects of the regulations are that they address the longevi-
ty of a site and how the site should be capped.
• Some types of liner systems that will be built because of the regula-
tions will be expensive in the short term. However, these liner systems
will be cost-effective in the long term, and will save clean-up costs
that will be in the billions of dollars.
• QA/QC requirements should be added to the regulations. However, they
should be written very carefully so that they are cost-effective and not
too restrictive. For instance, Watersaver likes to have the design en-
gineer on-site during construction and installation, but that is not
necessary for many small jobs.
• Installing contractor qualifications could also be added to the regula-
tions. As with QA/QC requirements, however, they should not be too
restricti ye.
• Installation procedures should not be specified in the regulations because
each facility is unique and may require special installation methods.
Research Needs
• Research on combining the use of geotextiles and synthetic membranes would
be useful. Watersaver has found that geotextiles are very useful when
placed on the bottom of a site because they can protect the subsoil and
provide an avenue for gas or liquid movement away from the site. However,
they can cause installation problems on exposed side slopes because they
alter the way the liner reacts to wind and other conditions.
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Interview No. A-5
Watersaver Company, Inc.
Page 6
• Research on the behavioral differences of liners in deep and shallow
ponds would also be helpful in tailoring fabrication techniques to the
specific conditions experienced by the liner.
Additional Suggested Contacts
The following companies/individuals can be contacted for further infor-
mation:
• Gaston Containment Systems, Inc.; El Dorado, KS. Contact Larry Gaston,
President. The firm is an excellent installing contractor.
• Dynamint Nobel of America (Harte); Rockleigh, NJ. Richard Dickenson is
the contact here; he has extensive experience with adhesive systems and
with CPE and PVC.
• J.P. Stevens; Arnold Peterson. The company is currently the top Hypalon
manufacturer and has good data on chemical resistance. They have per-
formed both accelerated laboratory tests and tests of liners which have
been in place for several years.
• SCA; John DiNapoli, Project Engineer. They have used synthetic liners
extensively in their facilities.
• Wehren Engineers; Middletown, NY; Dave Phillips. The company designs
all types of liner systems.
• Carlisle Tire & Rubber has been manufacturing liner materials continuous-
ly since the 1960’s and would be a good contact.
• Brookhaven, NY. Watersaver worked with them on a landfill liner system.
Contact Jim Hile for data on the installation.
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ASSESSMENT OF TECHNOLOGY FOR CONSTRUCTING AND
INSTALLING COVER AND BOTTOM LINER SYSTEMS
FOR HAZARDOUS WASTE FACILITIES
EPA Contract No. 68-02-3174; Work Assignment No. 109
INTERVIEW NO. A-6
E.I. DuPont De Nemours & Co.: Gerald E. Fisher TRW: Masood Ghassemi
I-Iinsdale, IL 312-986-0990 Michael Haro
John Metzger
Michael Powers
Sandra Quinlivan
18 January 1983 Louis Scinto
31 January 1983 Heather White
Summa ry
• Liners for hazardous waste facilities can be designed, constructed, and
operated so that they will not fail for 30 years or more. This, how-
ever, requires that the liner material suppliers, manufacturers, fabri-
cators, design engineers, dirt work contractors, installers, and facil-
ity operators recognize their respective responsibilities and communicate
effectively through all stages of material selection, manufacturing, etc.
Inadequate communication and failure to recognize and discharge respon-
sibilities are primary causes of liner failures. Education and communi-
cation are more effective in preventing such failures than regulation
alone.
• DuPont has developed and promotes the use of a liner ‘material qualifi-
cation form” which identifies the types of information required and
factors which should be considered in assuring a successful lining job.
The format is based on the premise that “the job dictates what liner
material should be used”. The information required includes: process!
waste compatibility data (waste composition, equipment, etc.), site
characteristics (temperature, wind velocity, soil type, etc.), and de-
sign requirements (unit size, dimensions and configurations., connec-
tions, etc.).
• Most cases of liner failure can be attributed to improper design due
to a lack of communication which leads to a poor installation. It is
possible to design around many of the potential problems if such
problems are identified during the design state.
• There is no single liner material (including clay) which would be com-
patible with all waste types. Based on short term laboratory compati-
bility tests, however, the spectrum of waste types encountered in a
commercial hazardous waste facility can be adequately handled with no
more than 3 or perhaps even 2 types of synthetic liner material.
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Interview No. A-6
E.I. DuPont de Nemours & Co.
Page 2
• Currently, there are no long term performance data for any liner mate-
rial (clay included) in actual landfill service. Laboratory compatibi-
lity tests and limited short term field experience indicate that
flexible membranes should withstand 30 years or more of service if
field installations incorporate systems for collection and continuous
removal of leachate and for waste segregation to keep out waste catego-
ries known to be incompatible with the liner material.
• It is very difficult to simulate actual field conditions in laboratory
compatibility tests (e.g., fluid immersion tests) and this should be
considered in the selection of liner material and estimation of per-
formance based on laboratory results.
• Singly or in combination with flexible membranes, clay liners can be
very suitable for certain applications and there should be no regula-
tory restrictions on the use of clay. In a multiple liner system
arrangement, clay and synthetic liners can compensate for the inherent
deficiencies of any single liner material.
• To date, there is not one set of specific criteria which is used
throughout the industry to define liner material uniformity and waste!
liner compatibility. For example, Hypalon liners must meet the require-
ments of containing at least 45 percent Hypalon 45 by weight as the sole
elastonier and a minimum set of physical specifications. Consequently,
as with all generic classes of liners (e.g., PVC, EPDM, HDPE, etc.),
Hypalon liners available from different manufacturers may vary widely
in properties. If verification of the physical properties is desired,
it should be so stated in the specifications.
• The present manufacturing equipment and methods (including QA/QC pro-
cedures) allow the production of a virtually pinhole-free liner and
the presence of pinholes in liners is no longer a matter of concern.
• To avoid damage to synthetic liners by construction equipment during
backfilling, it is necessary to specify the maximum weight for the
equipment which can be driven on the liner backfill. A QA technician
must also be present at the site to watch the equipment operator.
• 4ny regulations on liners and caps should include/address the following
concepts: (a) design flexibility to allow the use of clay and/or
flexible membranes as appropriate and to take into account site-specific
(location) factors; (b) minimum permeability (and not minimum liner
thickness) consideration; and (c) requirement for submission of detailed
analysis and documentation of the basis for design as part of the fa-
cility permit application.
• Areas in need of research and development include: (a) better defini-
tion of conditions and circumstances requiring the use of geotextiles
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Interview No. A-6
E.I. DuPont de Nemours & Co.
Page 3
or reinforced membranes; (b) development of long-term data on use of
backfills and leachate removal as measures to protect and extend the
life of liners; (c) development and demonstration of better seaming
methods; and (d) quantification of the credibility of liner materials.
Background
DuPont is a major supplier of raw elastomers (in the form of latex or
chips) for the manufacture of flexible membrane liners. It supplies material
to six manufacturers which market polyethylene, Neoprene, Hypalon, Nordel,
and Hytrel. The company is not involved in the actual manufacture of liners
and has no control over the selection of compounding ingredients (e.g., car-
bon black, pigments, fillers, plasticizers, accelerators, and antioxidants)
used in the manufacturing to impart various properties to the finished pro-
duct, but offers a suggested starting compound and sets required minimum
physical specifications. The company is also not involved in design and
installation of liners and covers, but it interfaces and offers guidance to
the manufacturers, fabricators, and installers as well as to the design en-
gineering contractors and facility operators. The company has an extensive
research and development effort aimed at developing improved elastomers with
a range of properties for different application needs.
The concept of “the job dictating what liner material should be used”
is actively promoted by DuPont which has developed a liner “material quali-
fication form” for addressing key information factors which should be con-
sidered in material selection, design, installation, and operation of liners
and covers. This interview report summarizes a presentation by Mr. Gerald
Fisher of DuPont to TRW, in which Mr. Fisher described various elements of
DuPont’s material qualification form and answered a number of questions re-
lating to Hypalon manufacture and performance; membrane-waste compatibility;
failure mechanisms; regulatory considerations; research and development
needs; quality assurance and quality control considerations; and additional
contacts and referrals.
On 31 January 1983, Mr. Fisher also arranged for TRW to visit: (a) its
Elastomers Laboratory in the Chestnut Run area of Wilmington, Delaware, where
the company conducts liner R&D work and compatibility tests, and (b) its
landfill at the Chambers Works (Deepwater, New Jersey). Mr. Fisher was
present during both visits. Additional information collected as a result
of these visits to DuPont R&D and testing laboratory and to the disposal
site is also included in this interview summary report. Many of the state-
ments and assertions made are largely qualitative and reflect the extensive
experience of Mr. Fisher; quantitative technical and engineering data to
support some of the statements and assertions were not provided. A copy of
DuPont’s “Material Qualification Form”, which is the basis for the following
discussion relating to liner selection, installation, and operation, appears
as an attachment to this interview report.
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Interview No. A-6
E.I. DuPont de Neniours & Co.
Page 4
Liner Selection, Installation, and Operation
• The principal design criteria for flexible membrane liners are: waste
(process) compatibility, sheet and seam strength, high and low tempe-
rature resistance, impermeability, longevity, and cost. The success
of any liner installation is highly dependent upon whether or not many
site-specific factors are met. DuPont has developed a “Liner Materials
Qualification” questionnaire which addresses these site-specific factors
and is intended to serve as an aid to the design engineer or purchasing
agent. The form, which is presented as an attachment, addresses the
following seven major topics or “factors” which bridge the coniniunica-
tion gap between engineering and sales: user identification; compati-
bility of liner material with waste input; site correlation; dimensions
and connections; landfill design; and bidding and follow—up considera-
tions. The following paragraphs discuss some highlights and several
major points associated with each of the seven factors.
Factor No. 1 - User Identification.
• This includes the general information on the prospective liner user.
DuPont believes that good communication between the client and the manu-
facturer is essential for a successful project.
Factor No. 2 - Compatibility (Liner With Input Waste).
• Waste temperature is an important consideration in liner material selec-
tion, since temperature variations cause liner expansion and contraction
and may result in seam rupture. Sometimes published liner temperature
tolerances do not apply to seams, and this factor is overlooked in liner
applications and may result in failures.
• Flow rate is another factor. Seams should be able to withstand high
flow rates. However, direct impurgement should be compensated for.
• Perhaps the most significant factor on the subject of compatibility is
waste composition. There is no single perfect liner for a combination
of all wastes. If there were, there would be no need for waste neutra-
lization and other pretreatment steps prior to disposal. Waste segre-
gation is also very important, as evidenced by the fact that most land-
fills today practice waste segregation.
• With respect to waste height, care must be taken to control load, in-
cluding vehicular traffic over the liner, which may cause puncturing
in unsupported materials. Factors such as the loading of the tires
then must be taken into account.
• Freeboard height for waste impoundments is an important but frequently
overlooked design factor. In general, gas vents are recommended around
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Interview No. A-6
E.I. DuPont de Nemours & Co.
Page 5
the freeboard area 12 inches down from the top of the berm, in order
to release gas caused by decomposing organics and air sucked in under
the liner by receding groundwater tables or other causes.
Factor No. 3 - Site Correlation.
• Site location is extremely relevant from the standpoint of liner selec-
tion and installation. For example, sites underlain with large deposits
of natural, high-quality, process compatible clay do not require syn-
thetic liners.
• There are a number of considerations involving site temperature. Field
seaming operations are dependent upon pressure, dwell time, and tempera-
ture. Wind chill factors cannot be disregarded in assessing whether
the seaming temperature lower limit can be met. It also determines the
choice of solvent used for seaming. For example, FMLs can be seamed
using trichioroethylene or toluene. If the ambient temperature is
above 65°F, toluene should be used since it has a lower flash point.
If the ambient temperature is below 55-65°F, seaming should be conducted
using a hot air gun. FMLs can be seamed under a mini-greenhouse at sub-
zero temperatures.
• The amount of rainfall is an important factor with respect to seaming
scheduling. Although liner repair work can be performed under wet con-
ditions, seaming cannot. In some cases, floating platforms have to be
used during repair operations in order to provide dry working areas.
• The amount and size of hail is a critical factor. Liners are designed
to elongate under field conditions. If a clay or sandy loam is used
under the liner, it will elongate properly and the hail will not punc-
ture the liner.
• Regarding side slopes, a s teep (3:1) slope may mandate the use of special
seaming techniques. To properly seam PVC using trichloroethylene/TFX
blends on steep slopes, the solvents should be applied from a poly-
ethylene bottle attached to a paint roller which prevents the solvents
from flowing out of the weld area. This eliminates tack welds.
• Regarding flexible membrane liner backfill requirements, a backfill or
a geotextile must be placed over Hypalon in order to reduce equipment
damage.
• A geotextile and rip rap should be used on impoundment slopes because a
soil backfill on a lined impoundment slope will eventually erode. This
leads to high maintenance costs.
• Animals can severely damage liners, especially deer. Preventative mea-
sures include use of fences, geotextiles, or vertical slopes, or instal-
lation of intentional watering and feeding areas away from operational
areas.
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E.I. DuPont de Nemours & Co.
Page 6
• Liner material selection is also dependent upon the degree of waste com-
paction. A thin, unsupported liner material requires good compaction
to eliminate subsidence which would create stress, cause distortion,
and result in liner fractures or seam failure.
Factor No. 4 - Dimensions and Connections.
• The best leak detection system is a French drain underlain with filter
cloth or having a backwash (flushing) system. The electrical conducti-
vity wire bridge system is not a long-term reliable leak detection
system because there often is natural oxidation of the wire grids and
the resultant resistance curves constantly vary.
• The types of foreign material (projections) the liner must be attached
to should have compatible expansion/contraction characteristics.
Stainless steel is a good choice. Concrete may also be used, but if
poor quality material or irresponsible labor is used, there may be void
spaces in the concrete. These voids can later be filled, however, if
discovered during final inspections.
Factor No. 5 - Landfill Design and Operation.
• Rapid removal of leachate can help protect flexible membrane liners
by reducing the contact time. This may eliminate the need for long-
term compatibility testing. Leachate collection systems are easy to
install in new facilities, but can be quite costly at older existing
sites.
• Synthetic liners can be very effective as caps in preventing rainwater
infiltration. The waste input should be well compacted to minimize
subsidence. The site should be graded to be self-draining and should
have a collection sump or runoff at the bottom, and the FML design should
anticipate additional spot subsidence.
• Only reinforced and uv resistant flexible membranes should be used as
capping material. Clay alone does not have any credibility as a cap-
ping material because of its tendency to fracture, erosion susceptibili-
ty, etc.
Factor No. 6 - Bidding.
• One should try to avoid giving bid specifications to anyone that does not
fulfill prior performance, reference, warranty, or bonding requirements.
• Bidders can be chosen from a variety of firms that manufacture, fabri-
cate, install, or perform a combination of all of the above; however,
verification of persons performing the installation is important as to
the degree of capability and past performance. Generally, firms specia-
lizing in installation would have the widest range of experience in
difficult installation conditions.
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E.I. DuPont de Nemours & Co.
Page 7
• If an FML is to be stored for a duration prior to site mobilization,
conditions and methods of storing should be predetermined and included
in the bid specifications. Timing of seaming operations to meet
weather conditions are also important.
• Labor rates and union considerations are noteworthy. At one site,
installation operations were shut down for six months because of a
strike. The weather became inclement over that period of time and
caused many problems.
• Utility requirements must be ascertained. For example, if Lyster hot
air guns are to be used, local codes must be identified and complied
with.
Factor No. 7 - Follow-Up.
• Numerous safety factors must be considered at each facility. Flexible
membrane liners can become very slippery when wet. Lagoons may need
to be fenced off, and/or tie-off ropes installed to assist in pulling
personnel from the lagoons. Adequate lighting is essential.
• QC measures must be taken to insure all systems remain intact over the
life of the site and after closure.
• Waste input loads should be periodically tested to see if their con-
tents match their reported values.
• There must be a good system of liner longevity backup testing. Samples
of the liner should be placed in strategic positions so that samples
can periodically be removed and sent back to the manufacturer in order
to identify changes in physical characteristics.
Hypa ion Manufacture and Performance
• Hypalon liners must, as a minimum specification, contain at least 45
percent by weight of Hypalon 45 as the sole elastomer and must meet
minimum physical specifications. Consequently, as with all generic
classes of liners (e.g., PVC, EPOM, HDPE, etc.), Hypalon liners avail-
able from different manufacturers may vary widely in properties.
• Hypalon leaves the plant uncured in order to make a film carrying bond
at the site. All FMLs should be spot checked upon delivery for physi-
cal specifications compliance; but this practice is not an industry
standard.
• Hypalon’s properties will vary over time. For example, tensile strength
will increase and elasticity will decrease. This change is altered by
different types of compounding which suit different applications. In-
dustrial grade (lead-based) Hypalon rather than “potable grade” Hypalon
is specified for hazardous waste landfill applications.
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Interview No. A-6
E.I. DuPont de Nemours & Co.
Page 8
• DuPont cannot refuse to sell its polymers to any liner manufacturer.
• Hypalon is a good landfill cover material because it is strong and uv
resistant; it is far superior to clay covers in preventing rainfall
penetration and infiltration.
Perspectives on Waste/Liner Compatibility
• Although waste inputs are complex and vary considerably, liner systems
can be designed to work successfully. However, one cannot say how
long the liner will work. The results of actual field performance are
generally more reliable than laboratory testing results.
• All liners are incompatible with certain waste types. For example,
solvents will dissolve most FMLs. Even clays are incompatible with
certain waste types. The type of clay is also an important factor which
should be taken into consideration.
• Compatibility tests provide important inputs in the process of selecting
a liner, but much of the information is limited to indicating potential
problem areas that need to be investigated. However, a good compatibi-
lity test result only means that the material meets the process require-
ments and not necessarily the physical and site conditions.
• Compatibility tests that reasonably simulate field conditions are very
difficult to devise. Even where the exact characteristics of the
corrosive fluid are known, a suitable test may not be possible. For
example, in certain immersion tests, all the contaminant may be sorbed
by the test material without any apparent change in its characteristics.
However, the physical characteristics of the material may in fact not
change until its sorptive capacity for the subject chemical is exhausted.
In the field, this sorptive capacity of the material may be quickly
overwhelmed.
• Compatibility tests should be done using fluids with contaminant levels
simulating those anticipated in the field. No pure level should be
used, as it is the combination that will be contained.
• All FMLs’ physicals change when wet vs. dry, or with age.
• Immersion tests should expose the material on one side only to realisti-
cally simulate its field condition. The dominant mechanism responsible
for mass transfer through a synthetic membrane is probably vapor trans-
fer. There is probably no gross movement of material through the mem-
brane and molecular diffusion probably involves a flux too small to be
important. The driving force for vapor transfer is differential vapor
pressure so that once the pressures on the two sides of the material
equilibrate, flow stops.
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Page 9
• For facilities that accept a large variety of waste inputs, use of
multiple liners is necessary to compensate for single liner deficien-
cies. For example, a comercial hazardous waste facility handling
virtually all types of wastes could definitely operate successfully
using three different liners, and could possibly get by with two.
Waste segregation is very important in such a case.
• At the DuPont testing laboratories in Wilmington, DE, materials are
tested both for customers who request the service and as part of the
company’s on-going research and development. Mixing facilities, small
calenders, and all other equipment needed to fabricate sheets support
the operations. All tests listed in the proposed NSF standards can be
done, plus more complex ones such as complete material fingerprinting.
The most routine physical tests made are tensile strength, stress—
strain (Young’s Modulus), and high/low temperature breakpoint.
• In selecting a specific liner material, the customer should follow a
step-wise process of elimination approach. First, they should try to
identify which process may contact the liner. Certain polymers will be
eliminated from further consideration based on this analysis. Next,
try to identify which acids and bases are involved, and eliminate other
candidate materials. Finally, physical factors which require use of
certain materials should be identified (e.g., use of a 2:1 slope ratio
will eliminate unsupported PVC and CPE liners). Most customers rely
heavily on the manufacturer’s experience when selecting a liner and con-
sider especially the material warranties that are available.
• DuPont strongly encourages customers who have made a materials selection
to obtain a letter of certification from the liner manufacturer guaran-
teeing that the liner will be compatible with the input waste, both from
the standpoint of waste composition and site design features.
• There currently is no one set of specific criteria which is used uni-
formly throughout the industry to define waste/liner compatibility and/
or material uniformity (QA). However, there are a few standards in
limited use. For example, one manufacturer considers a sample which
deforms to greater than 10 percent of its original weight and tensile
strength to be incompatible with the waste tested. DuPont has, for a
long time, wanted one set of ASTM standards to be applicable to all
FMLs. It has also wanted certain modifications to the existing ASTM
standards, many of which originated within the pulp and paper industry.
• Since FML manufacturers will provide clients interested in the compatibi-
lity/performance of its liner materials with the names of past customers
and/or with references to where, in general geographic terms, the mate-
rial has been successfully used, so that waste input and climatic!
topographic factors can be taken into consideration in liner selection.
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Page 10
• Many FML manufacturers believe that there are synthetic liners that can
withstand up to 30 years contact with leachate. However, there is a
paucity of long-term test data on the compatibility of both synthetic
and clay liners and leachate.
Perspectives on Liner Failure
• Both improper installation and design contribute to liner failure;
however, most problems are due to designs based on poor communication
between the engineer and the FML industry.
• Although liners can be designed and installed so that they will not
fail, whether or not they actually are well designed and installed is
a separate issue. DuPont’s approach is to work with the customer and
use the Liner Material Qualification form to help assure the landfill
operator and end user of a proper design.
• For flexible membranes, if there is to be a liner failure, it will
generally occur within the first two years following installation. More
rigid membranes can fail within five years of the installation, due to
steam, thermal, and stress fatigue.
• There is very little published information available on installations
and, for proprietary and business confidentiality reasons, manufacturers
cannot provide site specific liner failure data.
Perspectives on Regulations and Regulatory Needs
• Regulations should define acceptable limits and conditions. Methods
should be the sole prerogative of industry, engineering, and end users.
However, proof of performance and compliance should be incorporated in
said regulations.
• DuPont feels that education and communication are better approaches to
preventing liner failures than regulation alone. “Regulation provides
the. need; education and communication provide the means.” DuPont is
currently educating engineering firms and facility operators to use
the company’s Liner Material Qualification form. DuPont has suggested
that EPA consider this form or a similar one be submitted with facility
permit applications.
• The July 1982 regulations have serious problems. They were probably
written hastily and under pressure from numerous interested groups.
The liner/locational study is worthwhile in that it may result in the
incorporation of many needed compromises.
• The regulations should be made more site-specific. For example,
facilities should not be located into a water table since synthetic
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Page 11
liner seams cannot be properly made in the presence of moisture. Also,
sites located in areas of existing high groundwater contamination
should not be told to exceed conditions that already exist.
• EPA should not disallow the use of clay. There are justifiable appli-
cations for all liner materials.
• Rather than have the EPA run a QA program during liner installation, it
would be better to leave that task to existing qualified engineering
firms. One of their tasks should be to inspect the liner on the job
site and, if it was not up to specifications, order it returned to the
manufacturer at his expense.
• In promulgating a synthetic liner thickness requirement, the regula-
tions should require a minimum permeability specification, not a minimum
thickness.
• EPA should not get too involved with compounding because this consti-
tutes specifying a product for which the agency then becomes liable.
• In the area of foreign regulations, the Europeans are starting to follow
the lead of the United States. France, Italy, and Spain are just
starting to get interested. The more sophisticated countries of
Germany, The Netherlands, England, Switzerland, and the Scandinavian
countries do not have specific requirements regarding clay or synthetic
liners as yet, but do require that facilities be well operated. In
Australia, although there are currently no specific regulations,
various environmentalists and public interest groups are exerting
pressure on the larger firms to use liners.
Quality Assurance/Quality Control
• Whether or not bid specifications are actually followed during instal-
lation is not always verified. however, there are systems available
to determine the credibility of the liner and its seams. These include
seam peel and shear tests. The best test is the peel test; one can
improve shear test results simply by increasing the width of the seam.
• Field seams should be tested for credibility and in the lab for strength.
Useful seam testing techniques include the air lance test, conductivity
test, vacuum test, and standing water or dye test. There are new test-
ing concepts under development by the industry. One manufacturer
asserts that 1 mm is the limit for the ultrasonic test, but this has
not been verified. Seam voids are temperature dependent. Heat
collapses voids. Thus, measurements are temperature dependent.
• Field seam integrity is a function of: (a) leachability/impermeability
of the seam; (b) the physical strength of the seam; and (c) the degree
of variation in the seam based on installation conditions.
4-39
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Interview No. A-6
E.I. DuPont de Nemours & Co.
Page 12
• The more seams that can be done under controlled conditions at the
fabricator’s plant, the greater the integrity of the installation.
• The air lance test must be applied to every foot of seam in order to
test for leaks. But to test for strength, only one sample from every
500 to 1 ,000 linear feet of seam needs to be tested.
• It is virtually impossible to backfill a disposal unit without tearing
the flexible membrane unless a proper design and placement is specified
and followed. One of the most critical areas is where the equipment
is driven on and off the disposal unit. Having a QC technician con-
stantly watch the equipment operator and specifying the maximum weight
to be driven on the liner are two ways to alleviate this problem.
R&D Needs
The following areas would be good candidates for research and develop-
ment activities:
• Seams. Better methods need to be developed.
• Quantification of the credibility (permeability limits) of liner mate-
rials.
• Use of geotextile versus reinforced materials. When does one stop
using a reinforced material and convert to a geotextile? Some experts
believe geotextiles should be used everywhere. DuPont feels its usage
is more site-specific and based on experience. Specific criteria and
guidelines need to be developed.
Site Visit to the Land Disposal Facility at Chambers Works, Deepwater, NJ
• The land disposal facility receives waste sludges from a wastewater
treatment plant servicing the Chambers Works and drums containing tars
(these are placed in the center of the facility). There are three
five-acre fields. Field 1 is closed; Field 2 is being filled; and
Field 3 has just been constructed. A double liner was constructed in
Field 3, consisting of the following layers (extending from the upper
surface downward): Typar (a geotextile), 12-inch gravel layer with
leachate collection pipes, Typar, Hypalon, 4-inch sand layer, Typar,
8-inch gravel layer with leak detection pipes, Typar, Hypalon, and a
12-inch sand layer.
• Groundwater is at a depth of only 2 to 3 feet below the bottom of the
facility. To provide additional safety, the site was built up with
several feet of added soil, and French drains were installed to remove
excess water.
4-40
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Interview No. A-6
E.I. DuPont de Neniours & Co.
Page 13
• The following quality control measures were taken during the seaming
operation. Seams in the bottom Hypalon liner were checked with an air
lance. However, this method does not detect very small holes, and
since the upper Hypalon liner was considered more sensitive to the pro-
ject’s success, seams in it were checked by vacuum testing. The overall
integrity of the upper liner was also tested by a spark test. This test
detects small holes in the entire sheet by a conductivity method. It
requires a water layer below the material being tested, which was pro-
vided by moisture in the underlying sand layer.
• Field 2 has a liner system similar to that of Field 3. Shortly after
opening, the leak detection system showed a large flow, but its source
is believed to be water held by the sand layer. More water than nor-
mally expected may be squeezed out by the weight of the waste. Flows
from the leak detection system also showed some of the same character-
istics as leachate collected from that field. This, however, was not
believed indicative of a leak in the upper Hypalon liner. With time,
the strength of the leachate increased greatly while the strength of
the fluid from the leak detection system increased only marginally.
The leachate-like characteristics are believed to result from some
waste from Field 1 that accidentally got between the Hypalon liners of
Field 2 during its construction.
Miscellaneous
• DuPont can supply EPA/TRW with a rebuttal to Dr. Peter Montague’s re-
port on the liner failures in New Jersey, including the DuPont Chambers
Works Hypalon failure.
• The DuPont’s “Liner Materials Qualification” form is not perfect and
many factors could be added. Also, only ranges of certain values are
called for. However, it is a starting point toward responsible liner
design, installation, and maintenance.
• Recent advances in manufacturing technologies now allow manufacturing
of liners which are virtually free of pinholes and hence, presence of
pinholes in liners (laminated or single layers) is no longer a matter
of concern.
Additional Contacts/Referrals
The following individuals are additional contacts:
• John Pacey; Emcon Associates.
• Bill Way; Gulf Seal; Houston, TX. 713-359-2607.
4-41
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Interview b. A-6
E.I. DuPont de Nemours & Co.
Page 14
• Bill Karns; Project Engineer; Watkins Engineers and Constructors;
Route 3, Box 260; Perry, FL 32347. 904-584-0493.
Documents Provided
• E.I. DuPont de Nemours & Co., Wilmington, DE. (Company literature and
related journal articles on liner properties, design, and installation
specifications for Hypalon, Hytrel , Neoprene, and Nordel flexible mem-
branes.) Approximately 100 pp.
• “Preparing a Bid Specification”; Dupont, 7 pp.
• “Expansive Clays”; excerpt from reference handbook, 3 pp.
• HDPE failure test described in letter from W. Halter, Resin Search, Inc.
to Mr. B. Zolin, DuPont, dated March 2, 1981; 6 pp.
• “Installation Equipment and Methods”, describing weld (joint) testing
methods; 1 p.
• “American Vacuum Seal Tester” flyer; 1 p.
• “ASTM D34-05.Ol Guidelines”.
4-42
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DuPont’s Liner Materials Qualification Form
PREFACE
This material qualification form should not be misconstrued
as a design standard. It is intended to be an aid to the designing
engineer or purchasing agent. The format is based on the premise
that “the job dictates what liner material should be used”.
The majority of projects have in common, general qualifiers,
based on requirements the liner must fulfill:
• Process compatibility
• Sheet and seam strength
• High and low temperature resistance
• Impermeability
• Longevity
• Cost
These six basic liner requirements are fundamental and sound
but narrow in job scope. They acknowledge the basic liner needs,
but offer little understanding of the sites contributing factors
that determine the installation’s success.
A lining membrane is meant to be an impermeable container.
It is not compounded to be a structural entity. This is a function
of the design engineer, based on the following variables:
• Lining material
• Labor
• Site
• Service
This design versus use concept is intended as a bridge to cross
the communication gap between engineering and sales. Each knows his
own service requirements and abilities but only through communication
can individual job stresses be compensated for by engineering, and
the total cost of in line service life be determined.
4-43
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Liner Materials Qualification
Based on Design Vs. Use
Factor fl — Identification :
End User Engr. Firm_______________________________
Location Location________________________________
Contact Contact__________________________________
Telephone_ Telephone_______________________________
Factor U - Compatibility :
Process Composition
Temp. __________°C PH_________ Flow Rate__________ %Solids__________ _________
Aeration_____________________ Type_______________ No. _________
Freeboard Height Process Height_________________________
Product Reclamation Method Freq. ____________
Factor *3 - Site Correlation :
Site Location -
Ambient Temp High Low_______________ _________
100 yr. elev. of Ground Water Table________________
Aveiage Rainfall_____________________ _____________________
Liner Backfill Requirements _____________________
Type of Soil_______________________________
Type of Clay_________________________________ % Sand ________
% Orqanics________________ % Gypsum________________
Type of Traffic______________________________
Types of Vegetation
Floisture control-Method & Degree_____________
Cut & nil Requirements
Service
Size __________
Evaporation
Rate__________
Wind Velocity_________
Reservoir Base
Elev.
Amount & Size of Hail____________________
Application
Type Method
No. of Core Samples __________________
Limes tone_________
- Type of Anima]s
De j ice
of Compaction
4-44
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F actor #4 - Dimensions 6 Conr.ections :
- Slope
Reservoir Size. Length _Width Depth Ratio__________
Monitor System Method____________________________________________________________
Pipe
No. of Process Inlets Outlets Size Type__________
No. of projections through liner ______________Type Location_____________
Type of process impingement on Liner_____________________________________________
Type of foreigh material Liner must be attached to________________________________
Factor #5 - Landfill :
Composition__________
(8OUlbs/c ’ for
Fill Depth Age Volume sanitary fills)
Type of protective fill cover___________________________________________________
Type of Leachate Collection System______________________________________________
Type of Recirculation System_____________________________________________________
Temp. & Location of Fill Hot Spots_________________________________________________
Ratio of Carbon Dioxide to Methane______________________________________________
Gas Vent & Fleshback Design_____________________________________________________
Existing Type of Liner__________________________________________________________
Describe the Site Location & Surrounding Area___________________________________
Factor #6 — Bidding :
Approximate Bid Date Has Specification Been Written___________
Type of Installer Preferred_______________________________
Time Allotted for Installation____________________________
Mobilization Date________________________
Type of Labor: Union Non-Union_________ Plant..
4-45
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LaboL Rate & Type of Trade Required
Utility Services Required___________
Safety Requirements_________________
Terms of Contract & Delivery________
Factor *7 — Follow-Up :
Safety____________
Quality Control_____________________
Abuse Protection____________________
Longevity Back-Up___________________
Cominun ication ________________
4-46
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ASSESSMENT OF TECHNOLOGY FOR CONSTRUCTING AND
INSTALLING COVER AND BOTTOM LINER SYSTEMS
FOR HAZARDOUS WASTE FACILITIES
EPA Contract No. 68-02-3174; Work Assignment No. 109
INTERVIEW NO. A-7
M. Putternian & Co.: Jack Moreland TRW: Masood Ghassemi
Chicago, IL 312-927-4121 John F. Metzger
24 January 1983
Summary
• Good quality control at the fabrication stage alone is not sufficient
to ensure adequate liner performance. Quality control should be in
place throughout all stages of manufacturing, fabrication, transporta-
tion, site preparation, and installation. To this end, a turn key
approach which assigns the “chain of custody” for QA/QC to a single
contractor has substantial merits.
• Through regulations, education or other means, the user community
should be made to recognize the value of quality products, and to
consider more than merely costs in awarding bids.
• Because of the current lack of a QA/QC chain of custody, M. Putterman
& Co. (MPC) takes upon itself to “police” material suppliers by re-
quiring them to certify their products based on certain tests. The
material is also inspected at least at three points: when received
from the manufacturers, at the seaming machine, and when folded for
shipment. The capability of installers is also taken into account in
designing/specifying field seams (e.g., simple overlap vs. tongue-and-
groove).
• MPC’s QA/QC program for factory heat-weld seams includes the use of
“peel test” on test seams to establish optimum seaming conditions (tem-
perature, pressure, speed), use of experienced operators/technicians,
visual inspection of seams for extrusion of material at the interface
of the welded sheets, stress and creep testing of seam samples, and use
of tick marks to ensure proper lining of sheets prior to feeding into
the seaming machine.
• Spread coating method of liner manufacture is superior to calendering
as it provides little potential for formation of pinholes and allows
the use of higher scrim density, and thus development of higher strength
material and seams.
• R&D effort should emphasize development of new methods for joining liner
sheets and generation of “real world” data via tests in prototype
applications.
4-47
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Interview No. A-7
M. Putterman & Co.
Page 2
Background
M. Putterman and Company (MPC) is a fabricator of liner materials.
They seam sheets of the material received from the manufacturer into large
panels deliverable to the use site. MPC considers itself a leading fabri-
cator with a reputation for high fabricating standards. The firm specia-
lizes in liner fabrication for heavy duty uses and estimates that it now
commands a 45 percent share of the market for reinforced membrane liners
used in waste disposal applications. MPC has pioneered certain modifica-
tions to standard seaming equipment which allow better quality control and
more efficient operation. MPC’s asserted good reputation stems from the
thorough familiarity of several of MPC’s technical managers (in particular
Mr. J. Moreland) with all aspects of liner material formulation, fabrica-
tion, and installation. Thus, on major jobs, MPC’s personnel interface
with material suppliers, sheet manufacturers, design engineers, and instal-
lers, advising them on liner selection, required seam strength, chemical
compatibility, etc. This total involvement, which MPG considers not typical
of the fabricating industry as a whole, is based on the premise that fabri-
cation is only one of the elements of a chain which will lead to high liner
performance in actual field application.
The objective of this interview, which included a first—hand observa-
tion of a factory seaming operation, was to determine aspects of the fabri-
cating operation which influences eventual performance of a liner in a
waste disposal site application, and to obtain the perspectives of a
fabricator on liner installation problems, QA/QC issues, applicable regu-
lations, and research and development needs.
Fabricating Operation at MPC
• Many of the reported problems with synthetic membranes in land disposal
applications can be traced to faulty seams. The fabricator can greatly
reduce these problems by making high quality factory seams and provi-
ding guidance for field seams. High quality factory seams require a
good understanding of the factors affecting seam properties, and this
may necessitate a careful structural analysis of the seam, something
that is not done by most fabricators.
• Temperature and pressure are the critical variables that must be con-
trolled carefully during seaming.
• Factory seams are developed by several techniques, the choice being
dependent on the liner material. In the dielectric bar seaming method
used with certain materials, a current is passed through a bar im-
planted between the overlapped materials. The heat thereby generated
in combination with applied pressure welds the material. This method
is limited by the pressure which can be applied to a material to effect
seaming without causing excessive thinning of the heat-softened mate-
rial at the seam.
4-48
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Interview No. A-7
N. Putterman & Co.
Page 3
MPC usually fabricates seams for materials having a high melting
point. A specially-developed machine, modified from a standard de-
sign is used. The surfaces to be joined are heated to about 1000°F
(by a 10000F blast of air) and are pressed together at about 80 psi.
The two sheets are fed both by hand and by the machine advancing on
a track. The sheets overlap varies with the intended application of
the liner, but 2” is typical.
• MPC’s method of seaming liner sheets results in a weld with a strength
12 to 15 percent greater than by other systems. Where the material is
a reinforced thermoplastic and the overlap is 2 inches, the strength
of the material can be duplicated in the seam. The same seam strength
can sometimes be developed with certain unsupported copolynieric liners.
• Liner panels can be constructed to a maximum area of about 20,000
square feet. Smaller sizes, however, are more comonly handled as
better control can be maintained with smaller total areas. An average
sized panel of copolymer material is about 10,000 to 12,000 square
feet.
MPC’s Quality Control for Factory Seams and for Sheeting Materials Used in
Fabri cation
• At the start of the seaming operation, test sections of the material
are welded to obtain proper application temperature and pressure. The
correct combination, which is determined via “peel” test, corresponds
to conditions resulting in peeling off the liner material (top “coat”)
from the scrim reinforcement rather than separation of the sheets di-
rectly at the interface of the two surfaces.
• The main technique of quality control during seaming is visual inspec-
tion. An extrusion of material at the interface of the welded sheets
is a strong indication of a homogeneous bond, and the seal of the edges
of the material thereby formed encapsulates the scrin reinforcement and,
hence, prevents possible wickinq of leachate in actual field instal-
lations (wicking involves a slow flow/leak of leachate drawn through
the fiber reinforcement by capillary flow). These extrusions, however,
do not occur with Hypalon or butyl rubber.
• Every 400 feet, a sample of the seam is taken and tested in MPC’s
laboratories. Two of the tests are done to simulate creep of a stressed
liner in an unsupported condition, such as where it is pushed into a
sink hole. The material is loaded to 50 percent of its normal tensile
strength for 4 hours at room temperature. A similar test is made at 25
percent of its tensile strength for 4 hours at 160°F. Both tests are
evaluated on a pass or fail basis.
• Seams of highly elastic materials are sometimes also tested by an air
lance.
4-49
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Interview No. A-7
M. Putterman & Co.
Page 4
a Tick marks are made at equal distances from the end of each of the
two liner sections being joined. As the panels feed into the machine,
adjustments are made to keep the marks aligned. If the panels are not
aligned, one panel is elongated more than the other, building a stress
directly into the seam.
• MPC’s equipment and operations are often inspected by the customer
before bids are awarded and during the job. This practice is encou-
raged by MPG, especially for jobs requiring high liner performance
(e.g., for a hazardous waste facility).
• MPC frequently interfaces with its sheeting material suppliers to en-
sure use of high quality material in its fabrication operation. This
is done by requiring manufacturers to certify the material on the basis
of a series of tensile, tear, adhesion, and total weight tests. The
material is also inspected visually at three points: when received
from the manufacturer, at the seaming machine, and when folded.
Interaction With Field Operations
• The most important liner characteristics for good performance are
chemical compatibility, puncture resistance, and factory and field
seam integrity. The integrity of field seams is most difficult to en-
sure. MPC generally specifies to the installing contractors the re-
quired conditions for field seaming and the inspection procedures
needed to guarantee quality seams. Similar guidelines are generally
not given for Hypalon liners since there generally exists a much
broader experience with this material
• In specifying a particular seaming method to installers, MPC pays care-
ful attention to the qualifications of the installer. In IIPC’s judge-
rnent, there are only one or two contractors with a hiqh enouqh level of
expertise to produce high quality seams via simple overlapping methods.
For most others, a tongue and groove seam is specified because tongue
and groove can be fabricated in the factory, and there is little
opportunity for mistakes during field seaming.
• The liner can be damaged during transportation from the fabricator
to the job site. One of two methods of transportation is written into
the bid specifications: “FOB plant” and “FOB site”. FOB plant should
generally be avoided because the site owner will be responsible for
transportation to the job site, including writing of all specifica-
tions (e.g., crate specs) and handling all damage claims, and this is
often not conducive to assuring actual installation of a high quality
product. With FOB site, the fabricator assumes responsibility for
delivery of the product to the job site and, hence, checks the de-
livered material, and records and repairs minor damages. If damage is
too extensive, the shipment is rejected and the fabricator’s insurance
company takes up the subject.
4-50
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Interview No. A—7
M. Putterman & Co.
Page 5
Other QA/QC and Performance and Cost-Related Considerations
• Some competitors repeatedly underbid legitimate fabricators by offer-
ing inferior products for which there has been little or no quality
control. When the cost of QA/QC is deducted from the total price,
nearly all fabricators are competitive. (Because of its more elabo-
rate QA/QC program, MPC’s prices are usually 12 to 15 percent higher
than the competitors’. This problem, however, has been a manageable
one since a large part of MPC’s liner business is for complex jobs for
which there are no competitors or for which owners write specifications
so that potential competitors are discouraged from bidding.)
• Although more costly, a turn key approach to project management would
have a substantial potential for ensuring good liner performance.
Assigning the total responsibility to a single contractor is more con-
ducive to ensuring adequate quality control at all levels of the pro-
ject.
• Liner manufacturers most willing to stand behind their products ge-
nerally favor reinforced materials. A 36-mu reinforced membrane of
the type manufactured by MPC can perform equal or better than a clay
or a clay-reinforced synthetic membrane combination system.
• There are two fundamentally different methods of manufacturing a
synthetic liner: by calendering and by spread coating. The spread
coating method generally results in a higher quality product.
- For the calendered product, the pulp layers (sheets) are made
separately, then laminated. The density of the reinforcing scrim
is limited (generally to 10 per inch) because there is limited
opportunity for the two laminated sheets to flow across the voids
in the scrim to make a positive seal.
- In spread coating, the liner Is built up from layers of the mate-
rial applied as a liquid “coat”, and cured in an oven. The scrim
reinforcement is therefore completely encapsulated, permitting a
very high density scrim to be used. Since the strength of seams
is partly a function of scrim density, liners manufactured by the
spread coating method can be joined by very high strength seams.
- With the calendered product, pinholes are a possibility. However,
if the liner is constructed of several sheets, the pinholes of
adjacent layers are unlikely to line up. The pinholes, though,
may provide a point of liquid entry and hence leaking due to the
wicking action of certain scrims. Liners constructed by the spread
coating method should have no pinholes.
• A general misconception exists that the thickness of a liner is the
principal factor determining its performance (i.e., “thicker is always
better”). However, in an MPC-sponsored test, MPC’s 30-mil reinforced
4-51
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Interview No. A-7
M. Putterman & Co.
Page 6
liner developed fewer punctures than an unspecified 80-mil liner when
both were sandwiched between a base of 1-1/2 inch stone and a cover
of 8 inch diameter, angular stones.
Perspectives on Regulations
• Regulations (perhaps in the form of performance standards) can be
effective if they result in forcing the owners/operators of disposal
sites to consider more than merely cost when evaluating bids. Through
regulations, education or other means, the customer should be made to
recognize the value and the long-term benefits of good quality con-
trol programs, and to require such programs throughout manufacturing,
fabrication, transportation, and installation of liners.
Research and Development Needs
• R&D effort should emphasize development of new approaches to joining
liner sheets. For example, the engineering and cost aspects of a
mechanical seam (a “zipper”), which has been designed and tested by
Mr. Moreland of MPC in a grain storage facility application, should
be evaluated for possible use in landfill lining.
• R&D effort should also emphasize generation of “real world” data,
perhaps through studies involving testing of new designs and installa-
tion methods in prototype disposal sites.
Miscellaneous
• Synthetic liner materials manufactured in Europe are largely inferior
to U.S. products. Some European liners require a geotextile to pro-
vide additional strength.
• Polyethylene is a better material than PVC for piping of leachate.
PVC enibrittles.
• The principal suppliers of scrim to synthetic membrane manufacturers
are Burlington and J.P. Stevens. These companies can be contacted
for information on scrim properties and their importance in liner per-
formance.
4-52
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ASSESSMENT OF TECHNOLOGY FOR CONSTRUCTING AND
INSTALLING COVER AND BOTTOM LINER SYSTEMS
FOR HAZARDOUS WASTE FACILITIES
EPA Contract No. 68-02-3174; Work Assignment No. 109
INTERVIEW NO. A—8
American Colloid: Christopher Jepsen TRW: Masood Ghassenii
Skokie, IL Robert J. Masini John F. Metzger
312-966-5720
26 January 1983
Summary
• When treated with certain proprietary formulations to improve expanda-
bility and contaminant resistance, sodium montmorillonite can be mixed
with other soils to produce a material of low permeability (10-8 crn/sec)
suitable for use as liners. In mixed-blanket applications, the liner
permeability and self-healing properties are claimed to be superior to
those of native and reconipacted clay.
• American Colloid has made many laboratory permeability determinations
on its products over the years, using a low head test that passes two
pore volumes of permeate. Excellent correlation has been found between
these tests and the field condition, and the results have been confirmed
by the later performance of large—scale facilities.
• Based on extended laboratory permeability tests, chemically conditioned
bentonite is compatible with most leachate constituents with possible
exception of acetone and alcohols in concentrations exceeding 10 per-
cent. Possible effect of acetone and alcohols at concentrations ex-
ceeding 10 percent is currently under investigation. In a parallel
application as a liner material to contain tank farm spills, the ben-
tonite was compatible, at least on a short term basis, with concentrated
chemicals.
• As with other liner types, quality control during installation is essen-
tial to developing an adequate bentonite admix liner.
Background
American Colloid is the largest producer of sodium montmorillonite
(bentonite). It mines and processes bentonite at its facilities in Wyoming
and South Dakota. The largest current uses of bentonite, in the order of use
quantities, are in oil well drilling muds, iron ore pelletizing (taconite),
and foundry sand binding. These three uses account for 80 percent of the
tonnage used, Bentonite has characteristics largely unlike other clays. It
has the lowest permeability of all clays, is extremely expansive, and has
very high liquid and plastic limits. In liner applications, bentonite is
4-53
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Interview No. A-8
American Colloid
Page 2
used as an admixture. When mixed with another soil and hydrated, the bento-
nite swells and expands into voids, making a highly impermeable material that
is suitable as a liner. American Colloid asserts that for regulatory pur-
poses, its product should not be considered a “clay” material, but rather as
an admixture which has liner properties superior to both native and recom-
pacted clay. American Colloid does about 200 admixture lining jobs per year;
only about one to three of these jobs are landfills, the remainder are
lagoons and tank farm spill containment systems. Several bentonite liners
have been installed for DuPont for storage of chemicals and radioactive
wastes.
The purpose of the interview with American Colloid was to obtain tech-
nical information on the properties and installation of the bentonite admix-
tures.
Characteristics of Sodium Montmorillonite (Bentonite )
• For certain landfill applications, bentonite is treated to increase
its expandability and its resistance to various chemicals. It is
generally compatible with many chemicals likely to be present in hazar-
dous waste, with the exception of acetone and alcohols which are so
polar that they easily displace the bound water. Results of laboratory
tests assessing the long—term impact of various chemicals on the permea-
bility of bentonite products are presented in Table 1. As noted in the
table, there is no notable increase in permeability for the specific
solutions tested over extended contact periods. In applications where
bentonite is used for soil containment at tank farms, short-term con-
tact between the bentonite and concentrated chemicals has shown no
evidence of incompatibility.
• During the past 10 years, American Colloid has run upwards of 1,300 per-
meability columns. These tests have represented field conditions very
well, with no performance of any completed facility being contrary to
the permeability test predictions.
• When conducting permeability tests, American Colloid does not accele-
rate the time factor by using a high head, such as was done in some of
the testing by Dr. Kirk Brown (Texas A&M University; College Station,
TX). Instead, two pore volumes of fluid are collected under a maximum
head of 2.5 to 5 feet. This volume has been suggested in the litera-
ture as producing results that correlate well with field conditions.
• American Colloid specifies the amount of bentonite to be mixed with a
particular soil by applying empirically developed relationships to in—
house laboratory analyses of soil samples from the site. Soils exceed-
ing 40 percent gravel cannot be combined with bentonite because the
structure is not fine enough for the clay to seal.
4-54
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Interview No. A-8
American Colloid
Page 3
• Soils contaminated with oils or organics can affect the swell character-
istics of bentonite. Potential problems due to high concentrations of
ionizable species are indicated by a conductivity exceeding 250 iimho/cm
of a 200 gm sample added to 400 nil DI water. A free swell test is then
made to determine exactly how the swell properties are affected. Some-
times the clay particles flocculate rather than swell. The two condi-
tions are dissimilar in appearance, and the seal and long—term stability
of the flocculated state is considerably less. The usual remedial
action for contaminated soil is to use clean soil from another source
for mixing with bentonite. There has never been a need to excavate the
material or later add gas vents where organics are involved.
• American Colloid has not developed data on contaminant attenuation ca-
pacity of its products and has not carried out any side-by-side compa-
rison test with natural clay.
Liner Installation
• Several methods can be used to mix the bentonite with the soil, the most
expensive of which is use of a pugmill. An approximately 6-inch layer
of local soil is excavated (or, more likely, some other soil such as
sand is hauled in) and mixed with bentonite and water on a batch or con-
tinuous basis. The water used for hydration is always high quality,
usually drinking water quality. After pugnnilling, the admixed soil is
piled and bladed into place (or is laid with an asphalt paver). As an
alternative to pugmilling, the bentonite can be mixed into the in-situ
soil using a rotary tiller. Earlier methods substituted a discing or
raking device.
• Widths of the admixed soil are rolled for compaction. The edge of each
width is not rolled until the next width is applied and the edges are
overlapped. These successive widths bond together well and appear as a
continuous material.
• When bentonite is mixed into the local soil using a rotary tiller,
attaining the proper moisture content for compaction can be a problem.
If the local soil is too wet, the contractor may have to wait for it to
dry, whereupon any additional rain may resoak the soil , hence requiring
further delays.
• Bentonite holds water very well, but dessication can occur if the mate-
rial is not covered quickly enough after hydration. A cover of at least
6 inches is always used, although much less is actually required (just
a thin film of plastic or even a layer of gravel) to protect the mois-
ture. In an arid, southwest facility, dessication has not been a problem.
• The bentonite admixed soil has been placed in a 4-inch thick layer until
recently. A thicker layer of approximately 6 to 12 inches is now con-
sidered more satisfactory and is usually used.
4-55
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Interview No. A-8
American Colloid
Page 4
• The main requirement needed to ensure a successful facility is on-site
supervision. American Colloid usually maintains contact with the field
engineer to ensure that quality control is adequate and when requested,
will have a company representative on-site during actual installation.
• The failure rate of American Colloid lined sites is less than 1 percent
per year, and nearly all are attributed to the recommendations for
installation not being followed, especially mixing specifications.
Surface impoundments that fail at all usually do so shortly after being
filled.
Perspectives on Caps
• Differential settling is responsible for many cap failures. Bentonite,
however, is more plastic and therefore better able to follow deforma-
tions than native clays.
• Clay caps of any kind adhere poorly to an underlying synthetic membrane.
quality Control Considerations
• Bentonite is an effective liner material, but it, like others, requires
adequate quality control during installation. This, however, increases
costs so that underbidding by less consciencious competitors is a pro-
blem. In many cases, the bid specifications can be written sufficiently
restrictive to eliminate less competent companies. However, even many
design engineers do not fully appreciate the quality control needed when
applying a liner. Therefore, contractors should be required to have
quality control supervisors on-site at all times.
Miscellaneous
• Bentonite is more expensive than thin synthetic liners of about 20 mu
thickness. Depending on the hauling distance (the product has to be
shipped from mining/processing sites in the Northwest), it can be com-
petitive with the higher performance liner systems such as Hypalon.
• Some competitors have recently entered the landfill lining market because
their principal market of drilling muds has declined. Unfortunately,
the material being sold as a liner admixture is essentially the same as
a drilling mud and has not received the special treatment that American
Colloid’s products receive to make them suitable for liner application.
• The following facilities are examples of American Colloid’s jobs:
- A site near Queensbury, New York, owned by the Ciba Geigy Company.
This landfill is one of the documented cases of a contaminant resis-
4-56
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Interview No. A-8
American Colloid
Page 5
tant bentonite being used successfully. American Colloid is re-
quired to maintain a column simulation of the field (a clay liner
overlaid by a sludge from the manufacture of dye with DI water
added) conditions throughout the entire active life of the facil-
ity. A second facility is to be installed soon. Contact: Basil
Burns.
- General Electric Corp.; Gainsville, FL. Contact: J. Mary Phillips;
Environmental Engineering, Building 36/120; Schenectady, New York
12345. 518-385-5161
— Olin Chemical, Tenn. This facility contains a calcium hypochlorite
sludge. The liner system consists of the following layers from the
top surface working downward: 8-inch gravel, 7-inch concrete sand,
1-foot native clay compacted, two 6-inch lifts of bentonite, 3-feet
compacted clay, 4-inch gravel, 4-inch concrete sand, and 4-inch
gravel. The following layers are on the sideslopes: 1-foot gravel,
3—feet native clay, two 3-inch bentonite soil mixtures. Contact:
Charles Hawk, 615_336_2251*.
• Art Clem is a good source of experience with bentonite. He was previous-
ly with American Colloid for 40 years and has developed numerous products
for the company. His address: Cleni International; Des Plains, Illinois.
312-296-3834.
*
TRW later contacted Charles Hawk and was told that the waste is a mercury-
contaminated sandy sludge. A calcium hypochlorite sludge is also somehow
involved, but it was not certain how. TRW was referred to Dave Vaughn,
61 5—336—4555.
4-57
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(71
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LONG-TERM LABORATORY PERMEABILITY DATA FOR BENTONITE WITH VARIOUS SOLUTIONS AND LEACHATE
Col. No.
Thickness
Leachate Product (inches)
ApI
Rate
ppsf
Dates Run
of
Days
Run
rn/s
Passed
Through
PVD
Head
Permeability
R8 1-65
760
729
8061/1636A
10% CaC1 2 (L) SS-100 4
1% CaC1 2 SLS-71 2
10% CaC1 2 (B) 55-100 2
10% Ca(OC1) 2 SLS-70 4
PCB Soin. SLS-7 1 2
3 30
1.65
3 30
2 50
1 65
2/17/81 - 9/4/81
6/13/77 - 1/3/80
8/23/76 - 1/13/77
7/27/79 - 8/15/79
3/31/76 - 8/4/76
197
934
141
19
126
126
11210
136
58
2.8
0.5
91.1
1.1
0.2
0.02
2.5
2.5
2.5
2.5
2.5
2.8 x io _8
4.4 x
3.5 x
1.0 x io_6
1.0 x 10
712
Gasoline SS-l00 2
1 32
7/30/76 - 10/6/76
68
61.2
0.6
2.5
4.7 x l0
Kerosene 55-100 4
3 90
1/4/81 - 4/8/81
85
40 2
0.16
2.5
4.7 x io_8
457
Lime sludge SS-100 2
3.30
5/11/76 - 6/1176
20
---
---
2.5
NLD
818
Ether TFS-81 4
3.30
10/17/79- 1/4/80
79
41.9
0.17
2.5
1.5 x 10 ’
756
10% KC1 SS-100 2
3.30
5/23/77 - 3/14/78
326
232.5
1.89
2.5
3.4 x 10
825-D
Acid waste SS-100 4
9.00
3/14/80 - 6/4/80
82
194.5
0.79
5.0
5.9 x 10_8
737
715
804
801
799A
2506P
3% NH C1 SS-100 2
10% NH 4 C1 SS-100 2
10% NH 4 C1 Improved SS-100 2
10% NH 4 C1 SS-100 2
10% NH 4 C1 SS-100 2
Acid waste sludge SS-lOO 4
3.30
3.30
1.65
1.65
2 00
3.30
1/31/77 - 7/22/77
3/8/77 - 1/3/80
11/2/78 - 1/3/80
10/30/78- 6/21/82
1/29/79 - 6/21/82
2/18/81 -11/20/82
173
1090
481
1330
1266
375
172.8
3625.5
1615 8
18665
15983
235 4
1.40
29.4
13.1
152.0
130.0
0.95
2.5
2.5
2.5
2.5
2.5
2.5
2.8 x l0
2.7 x io_6
1.5 x 10
8.3 x 10
7.6 x lO
9.5 x io_8
R81-62
Sludge from paper mill SS-l00 4
3 30
2/18/81 - 3/29/82
414
784.6
2.97
2.5
2 0
Oil w/low level PCB SS-lOO 4
3.30
2/17/81 - 9/14/81
210
125.6
0.51
2.5
2.8 x io_8
R81-1678
Paper mill w.w SS-100 6
3 70
7/13/81 - 4/2/82
264
1048
2.84
5.0
2.2 x l0_8
2” volume = 411.3 cc @ 30 PV = 123 rn/s.
4 volume 822.6 cc @ 30 PV 247 rn/s
NLD = No loss detected.
-------
ASSESSMENT OF TECHNOLOGY FOR CONSTRUCTING AND
INSTALLING COVER AND BOTTOM LINER SYSTEMS
FOR HAZARDOUS WASTE FACILITIES
EPA Contract No. 68-02-3174; Work Assignment No. 109
INTERVIEW NO. A-9
Woodward-Clyde Consultants: Jean-Pierre Giroud TRW: Masood Ghassemi
Chicago, IL 312-939-1000 John F. Metzger
27 January 1983
Summary
• With the proper approach and supporting investigations, liner systems
can be designed so that they will not fail. Most failures result from
poor design or the use of low quality materials due to owners consider-
ing cost as the overriding decision variable. Education to upgrade
the profession is needed and can perhaps be best accomplished by EPA
through technology transfer seminars and training courses with emphasis
on increasing the understanding of the personnel at regulatory per-
mitting agencies so that they can require proper design and installa-
tion procedures from permit applicants.
• The argument that clay is a natural product that has been around for
millions of years and, hence, has a better track record and can, there-
fore, be trusted more than synthetic materials for lining hazardous
waste sites is too simplistic. It can be countered with an equally
simplistic argument that, in its natural environment, clay has not been
in contact with waste products of a modern industrial society and that
man-made liners can perhaps provide a better answer to man-made
problems than natural liners. Many designers feel more comfortable
with clay because they are more familiar with clay properties and there
is more experience with design of clay structures.
• In some respect, a synthetic liner is probably superior to a clay liner
although a clay underlying a synthetic liner has merit. In all cases,
leachate should be removed from the facility and attenuation properties
of clay liners should not be relied upon as the sole means to prevent
migration of pollutants.
• Pinholes in synthetic liners, if they exist, do not pose a major problem.
No known failures have been promoted by pinholes.
• Research and development effort to date has not been sufficient regarding
practical design concerns. Areas requiring emphasis include development
of: (a) design/construction criteria for making connections between geo-
membrane and concrete structures; (b) better sump systems for leachate
collection in landfills; and (c) development of seaming specifications.
4-59
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Interview No. A-9
Woodward-Clyde Consul tants
Page 2
• Overall, the liner manufacturing, fabrication, and installation techno-
logies in the U.S. are superior to those used overseas.
Background
Woodward-Clyde Consultants provides consulting services in the field
of geomembranes and geotextiles out of their Chicago office. Dr. Jean-Pierre
Giroud, Director of the Geotextiles and Geornembranes group, is an interna-
tionally-recognized expert on the subject and has authored numerous tech-
nical papers on the design of geomembranes and geotextiles. He has indeed
coined the terms geoniembrane” and “geotextile” and has extensive experience
in both academic and consulting practice. The purpose of the interview was
to obtain Dr. Giroud’s perspectives on liner installation problems and
related matters.
General Design Considerations
• Identification of conditions which may lead to failure is an important
design element. For example, a small leak might not be a problem
unless it can trigge.r a larger problem. A case in point is an inci-
dence where a small hole in a surface impoundment holding acidic
waste (pH ‘ 1.0) resulted in a major failure within 11 months of in-
stallation. The slow but continuous leakage into the underlying
carbonate—containing stratum resulted in a very large sink hole.
• With the conditions of failure established, all potential mechanisms
of failure must be identified and addressed during design. With current
technology, most failure mechanisms can be mitigated. The analyses
generally require an extensive geotechnical investigation, but such an
investigation is seldom undertaken and this can lead to poor design and
hence possible liner failure. Thus, liners can be designed and instal-
led so that they will not fail.
• A leaking liner does not fit the definition of a failure per se since
all liners leak to a certain extent. Instead, the amount of leakage
that can be tolerated and is expected must be identified and worked
into the design.
• All land disposal systems should provide leachate removal. The concept
of using only attenuation by leachate flowing through a clay liner to
control pollution is a poor one. Deliberate movement of leachate into
the ground is always a highly uncertain and potentially dangerous pro-
position. However, clay layers as an attenuating backup to a synthetic
membrane have plenty of merit. Leachate should be removed from the
landfill in all cases, although this may often be difficult with a com-
monly used bottom slope of 2 percent which promotes ponding.
• Leachate removal essentially provides for the transfer of the leachate
from a difficult-to-control environment (i.e., the landfill) to a more
4-60
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Interview No. A-9
Woodward-Clyde Consul tants
Page 3
controllable one (i.e., surface treatment and/or direct discharge to
public wastewater treatment plants). This approach is preferable to
leachate recirculation schemes. One scheme involves circulation of
leachate through the gravel liner cover layer thereby promoting dilu-
tion of any highly corrosive leachate and hence drastic impact on the
liner. This system, however, may not be feasible due to shallow bottom
slopes which may not sustain adequate flow.
Relative Merits of Clay and Synthetic Liners
• Many opportunities exist for problems to develop with a synthetic
membrane liner, but these generally result from a lack of knowledge.
The body of knowledge and level of experience of all concerned parties
is more highly developed for clay liners than for synthetic liners.
• Arguments asserting that clay is a good liner material because it is
highly stable as evidenced by its being around for millions of years
are not valid. More importantly, the material has not been in con-
tact with a leachate environment for the same or even a much shorter
period.
• Precautions must be taken with clay liners to prevent cracking as the
result of dessication. One method of preventing this loss of moisture
is to place an extra foot of clay, then scrape it off at the last
opportunity. Alternatively, a temporary cover can be placed.
• The method of clay compaction and, hence, the degree of compaction
achieved has often been the same as that practiced for large embank-
inents or dams; this degree of compaction, however, may not be appro-
priate for liners. A highly compacted clay can be more sensitive to
changes in density resulting from loss of moisture. Slightly less com-
paction than is generally used may, therefore, be optimal. (Dr. 3.
Mitchell, of the University of California at Berkeley, can be consulted
for additional details on the effect of compaction on clay properties.)
• The current regulations suggest that a synthetic membrane placed direct-
ly on top of clay can provide a good liner system. This assessment
would probably be true if leachate passing through the synthetic liner
would be absorbed by the clay liner at the close vicinity of the leak.
In actual practice, however, there will seldom be perfect contact
between the synthetic and clay liners, and channels will be present
through which leachate will flow and accumulate at low points in the
interface. The condition of perfect and continuous contact between the
two layers may only be approached when the facility is full and, hence,
large pressures are exerted on the liner. Also, better contact occurs
if the clay is soft, compacted at less than its maximum. Including a
layer of permeable material, such as a geotextile, between the two
liners can increase the potential for flow between the two liners.
4-61
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Interview No. A-9
Woodward-Clyde Consul tants
Page 4
• Contrary to the generally held view, pinholes are not much of a problem
in liner design and performance (consult H. Haxo for data). While there
seems to be no evidence indicting pinholes in a liner failure, they
could conceivably present a problem with a reinforced liner due to
wicking action of the reinforcing scrim.
• Pinholes are much less of a problem than it has been generally asserted
and there seems to be no evidence indicting pinholes in liner failures.
• The assertion that pinholes would not be of consequence with laminated
liners due to a very low probability that pinholes in different layers
would ‘line up” at exactly the same spots may not always be true because
of the possible wicking action of certain scrims.
• In general, because of their characteristics, geomembranes would per-
form better on slopes than on bottoms. A reasonable solution would
perhaps be to use clay as the bottom liner and to use geomembrane on
the side slopes.
• Pinholes can be defined to have a maximum diameter of approximately 0.1
nm. The larger ones can be detected visually if there is sufficient
light behind the material. The results of one study with a water con-
tainnient system suggested that 2000 pinholes are equivalent to one hole
of 10 mm diameter or 10 holes of 3 mm diameter. (More information on
pinholes can be obtained from Dr. Henry Haxo of Matrecon, Oakland, CA.)
• Recycling of scrap material to the polymer melting pot can result in
pinhole formation during calendering. This is especially true with re-
inforced liners when scrirn material is present in the recycled scraps.
The liner product quality standards which are being developed by the
National Sanitation Foundation NSF) are expected to address the scrim
recycl ing problem.
• There is no clear way to establish compatibility of a synthetic liner
with leachate. In selecting and designing liners, Woodward-Clyde follows
the following steps:
a) Identify chemicals in waste.
b) Screen available geornembranes for chemical compatibility using data
in manufacturers’ literature.
c) Discuss anticipated chemical composition of waste with manufacturers
of prospective liners.
d) Select liner candidate(s) based on steps b) and c) above.
e) After a liner material has been selected, conduct compatibility tests
(which usually take upwards of four months) to identify incompatible
wastes so that restrictions can be placed on their acceptance to the
proposed site.
4-62
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Interview No. A-9
Woodward-Clyde Consul tants
Page 5
• Animals can be a potential problem. Any rodent so inclined can chew
through the liner; however, this does not seem to be much of a problem.
Perspectives on Caps
• Clay will not slip on a synthetic membrane if it is underlaid by a pro-
perly designed geotextile.
a Synthetic materials can better handle subsidence than clays and are
therefore preferred as a cap. Unreinforced membranes can elongate up-
wards of 300 percent (maximum elongation for reinforced liners is
usually about 20 percent). The ability of liners to elongate decreases
somewhat with time, but the decrease is not large if the liner has been
protected by a cover.
Quality Control Considerations
• Quality control requirements are specific to each project, but special
attention should always be given to seaming and connections between
liners and structures.
• All seams should be inspected visually and with at least one piece of
equipment such as an air lance, an ultrasonic detector, or a vacuum
detector. Factory seams are not necessarily always better than field
seams and it is good practice to test factory seams in both the factory
and the field.
• Criticism of the ultrasonic test is largely unfounded. In one job, one
mile of seams was checked and the ultrasonic test was in error on only
four inches.
• Manufacturing limitations involving the scrim make it difficult to follow
seam specifications. A minimum scrim to scrim overlap is generally re-
quired with no loose, upper flap. The width of the seam is, therefore,
measured from the upper edge backward, but the width of selvage is highly
variable, even on one roll, resulting in a variable scrim overlap if a
constant seam width is constructed. Further complicating field opera-
tions, seam specifications are sometimes poorly written with requirements
that, when considered together, are contradictory.
• Connections between the liner and structures are often poorly designed.
Certain aeonetries (e.g., sharp corners) are not easily handled and
should be avoided in the design of structures. Quality control of con-
nections is also very important since the liner is usually heavily
stressed in these areas. Stresses include those resu1ting from differen-
tial settlement, gravity pull on slopes, and differential contraction.
• The quality of connections has, in the past, been poor because they were
made last. At that point, the contractor is usually anxious to move
his crews to another job. Either the work is done in a hurry or an in-
experienced crew is sent to finish the project.
4-63
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Interview No. A-9
Woodward-Clyde Consultants
Page 6
Institutional Barriers to Development of Adequate Facilities
• There are numerous problems within the industry that result from a poor
understanding of liner and land disposal technology. Two problems in
particular are design of facilities by inexperienced engineers, and the
proliferation of low bids that subvert the efforts of quality contrac-
tors and suppliers. If, for example, a material supplier does not com-
promise quality or quality control, he will probably be underbid (a good
turn key liner project which would have reasonable assurance of good
performance may cost 25 percent or more than an average job). Unfor-
tunately, the principal decision variable considered by owners is
often cost. Generally, two types of clients can be identified: those
who are willing to accept marginal designs and materials and those who
want superior designs and materials with no costs spared. The latter
is characteristic of private companies and commercial waste disposal
firms. But the purchasing departments of these firms also apply pres-
sure, at times, to cut costs.
• In the past, there has been little incentive to develop an adequate
land disposal facility. But with increasing public attention and lia-
bility problems, the incentive may now exists to develop a facility
that works rather than one that is within budget. Education is an on-
going process and should naturally upgrade the profession within 10 to
20 years to a point where adequate facilities are developed. However,
such a lengthy period cannot be afforded, and something is needed to
speed up the process. EPA can be very instrumental in speeding up the
educational process by promoting transfer of information on latest
technologies to the user community, in particular to the personnel at
regulatory agencies responsible for permit review and approval. This
education process should be very specific, should address facts as well
as philosophy, and should be aimed at increasing the awareness of all
parties involved. This awareness can be promoted by requiring each
facility to meet a checklist of general procedures for design and
quality control. Specific requirements (most importantly, quality con-
trol) can be written directly into the permit application.
• A checklist of design procedures and quality control providing detailed
instructions for installation of synthetic liners for land disposal fa-
cilities has been developed by Woodward-Clyde under a subcontract to TRW
in connection with present effort. The detailed instructions, which
address the following topics, follow this interview summary:
- Selection of suppliers (manufacturers, fabricators, and installers).
- Installation procedures, including ground preparation and general re-
commendations regarding seaming procedures with specific examples for
three liner types: high density polyethylene (HDPE), Hypalon, and
polyvinyl chloride (PVC).
- Quality control to be requested from suppliers.
- Quality assurance to be requested from site engineers.
4-64
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Interview No. A—9
Woodward-Clyde Consultants
Page 7
• Sometimes even respectable firms send inexperienced field crews to a
site. Some structure may therefore be needed to guarantee minimum
qualifications of individuals within firms actually involved in the
installation, particularly seaming. On some projects, Woodward-Clyde
requires passage of a practical examination. On another project (in
Africa), local people were trained to do the seaming; practice
seams were made and tested, and the most accomplished seamers
were selected for the job. Quality control of seams has also been im-
proved by numbering the seams (on design drawing) and recording the
individual assigned to specific seams.
• Performance standards are not an appropriate approach to ensuring
quality installation, mainly because it is difficult to both define
and determine a failure. Also, such a system could, in some instances,
be subverted. For example, facilities having a double synthetic
membrane might intentionally be constructed with the lower membrane
being less than adequate so that any leachate passing the first liner
would pass through the second liner, thus escaping detection by any
leachate collection detection system placed in between the two liners.
Since monitoring wells are also not required for double-lined facili-
ties, the escaping leachate would move unnoticed into the ground.
U.S. Vs. Foreign Technologies
• Possibly more mistakes are made at foreign installations than in
U.S. installations and, in this respect, foreign experience can pro-
vide valuable lessons.
• A foreign method of welding elastonierics is superior but is not usable
in the U.S., apparently because of differences in materials. Foreign
fabricators seem to work with EPOM and butyl rubber that is less fully
cured. In general, field techniques and quality control are better in
the U.S. than in Europe.
• In general, fabrication is better in the United States than overseas.
• Insurance companies are involved in European facilities but do not play
the prominant role that they could. Requirements are set forth for
issuing insurance, but these requirements, especially for quality con-
trol, are minimal.
Research and Development Needs
• More important than technical improvements is organization of the pro-
fession so that information on current technologies is fully dissemi-
nated and properly applied. A large gap exists here. For example,
quality control guidance could be included in permit requirements.
4-65
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Interview No. A-9
Woodward-Clyde Consultants
Page 8
• While research to date has been very fruitful , practical concerns of
designs have not been addressed. For example, the recommended seam
width values which are presumably based on capabilities of existing
equipment have not been supported by data from systematic engineering
and scientific research.
• The following can be cited as technical research needs:
- For liquid impoundments: improvement of connections between the
geomembrane and concrete structures (development of design/con-
struction criteria).
- For landfills: development of a good sump system. Sumps are the
most delicate part of the entire landfill system because there are
many connections to it and the largest concentration of leachate
exists in its vicinity. A standard, prefabricated sump might be
appropriate.
- Development of a good set of specifications for seaming, particular-
ly the practical aspects that have largely not been addressed to
date. The specifications should be compatible with seaming equip-
ment, existing or proposed.
4-66
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GUIDE
SPECIFICATIONS
FOR
CONSTRUCTION
OF
FLEXIBLE MEMBRANE UNERS
FOR
HAZARDOUS WASTE DISPOSAL FACILITIES
Prepared for
TRW INC
Energy and Enivron mental Division
Suite 200
23900 Hawthorne Blvd
Torrance, California 90505
P
ierre Giroud Kenneth H. Kastman
Voodward-Clyde Consultants
Suite 1500
11 East Adams Street
Chicago, Illinois 60603
83C005-2
15 February 1983
4-67
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GUIDE
SPECIFICATIONS
FOR
CONSTRUCTION
OF
FLEXIBLE MEMBRANE LINERS
FOR
HAZARDOUS WASTE DISPOSAL FACILITIES
FOREWORD
The following Guide Specifications represent an
effort to establish a comprehensive framework to
verify and document the construction of a flexible
membrane liner (FML) system for hazardous waste
disposal facilities. Some of the technical requirements
may have significant impact upon the FML industry
and review and comments should be solicited from
industry representatives.
WOOD WARD-CLYDE CONSULTANTS
4-68
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—2-
TABLE OF CONTENTS
Page
INTRODUCTION 5
FML CONSTRUCTORS 6
1.1 FML Manufacturer 6
1.2 FML Fabricator 6
13 FML Installer 6
2 FLEXIBLE MEMBRANE LINER 7
2.1 Raw Materials 7
2.2 Rolls
2.3 Blanket Fabrication 9
2.3.1 Blanket Geometry 9
2.3.2 Factory Seaming 9
3 INSTALLATION 11
3.1 Definition of Responsibilities ii
3.2 Surface Preparation 11
3.3 Handling of FML 12
3.3.1 Packaging 12
3.3.2 Transportation 12
3.3.3 On-site Storage 12
3.3.4 On-site Handling 12
3.3.5 Panel Placement 12
3.4 Considerations of Site Geometry 14
3.4.1 Layout Drawings 14
3.4.2 Anchor Trench 14
3.4.3 Installation Around Appurtenances 14
4-69
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-3-
TABLE OF CONTENTS
(continued)
Page
3.5 Field Seaming 15
3.5.1 Requirements of Personnel 15
3.5.2 Overlapping 15
3.5.3 Preparation 15
3.5.4 Seaming Equipment and Products 15
3.5.5 Weather Conditions for Seaming 16
3.5.6 Seaming Procedure 16
3.5.7 Procedure for Seaming Wrinkles 17
3.5.8 Cap-Strips 18
3.6 Installation of Materials in Contact with
the Geomembrane 19
3.6.1 Granular Materials 19
3.6.2 Concrete 19
3.6.3 Geotextiles 20
4 QUALITY CONTROL AND INSPECTION 20
4.1 Materials 20
4.2 Factory Seams 20
4.2.1 Inspection 20
4.2.2 Non-Destructive Testing 21
4.2.3 Destructive Testing 22
4.3 Transportation, Handling and Placement 22
4.4 Field Seams 23
4.4.1 Field Seaming Operations 23
4.4.2 Test Seams 23
4.4.3 Non-Destructive Seam Testing 23
4.4.4 Destructive Seam Testing 24
4.4.5 Verification of Special Seams 25
4.5 Defects and Repairs 26
4.5.1 Identification 26
4.5.2 Evaluation 26
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TABLE OF CONTENTS
(continued)
Page
4.5.3 Repair Procedures 26
4.5.4 Verification of Repairs 26
4.6 Documentation 27
4.6.1 Material Quality Control Certificates 27
4.6.2 Surface Preparation Certificate 27
4.6.3 Daily Fabrication Reports 27
4.6.4 Daily Field Installation Reports 27
5 PERFORMANCE REQUIREMENTS AND ACCEPTANCE OF INSTALLATION 28
5.1 Guarantees 29
5.2 Performance Expectations 29
5.3 Long Term Monitoring 29
5.3.1 Exterior Monitoring System 29
5.3.2 Leak Detection System 29
5.3.3 Leachate Collection (Specific For Land 29
Disposal Cells and Waste Piles)
5.3.4 Coupon Monitoring Program 29
5.4 FML Acceptance 30
NOTES 31
APPENDIX: DEFINITION OF TERMS 32
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INTRODUCTION
The Guide Specifications which follow are intended to be used by persons writing
specifications for the Construction of a flexible membrane liner (FML) for land disposal
of hazardous wastes.
The specifications do not relate to design of the FML system but rather provide
guidelines for control and verification of construction of the designed FML system. The
guidelines are not all inclusive to the needs of each site but form a framework into which
site specific requirements can be inserted. Where appropriate, choices are provided,
with examples for high density polyethylene (HDPE), reinforced chiorosulfonated
polyethylene (CSPER, known as “Hypalon”) and polyvinyl chloride (PVC).
These specifications have recognized the need to verify that the installed FML
must provide total containment of hazardous waste fluids. This recognition resulted in
requirements for thorough quality control during FML fabrication and installation, and
systematic documentation. Further, the recognition of the parties involved in FML
installation and the need for these parties of agree on individual responsibilities have
been highlighted.
Parties who may be involved with FML installation include: Designer, Earthwork
Constructor, FML Fabricator, FML Installer, FML Manufacturer, Inspector, Monitor,
Owner, Regulatory Authority, and Specifier. These terms are defined in the Appendix.
Each of these parties may be involved in FML installation, or responsibilities defined for
one party may be assumed by another party (ie, the FML Manufacturer may also be the
FML Fabricator).
Reference is made in the text to the test procedures of the American Society or
Testing and Materials (ASTM) and the Proposed Standards for Flexible Membrane Liners
of the National Sanitation Foundation (NSF).
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1 FML CONSTRUCTORS
LI FML Manufacturer
To demonstrate an ability to manufacture the FML rolls, the FML Manufacturer
shall provide the Monitor with a list of at least — projects totaling a minimum of
hundreds of thousands m 2 (millions sq. it), for which the FML Manufacturer supplied the
same generic type of FML. For each project, the following information shall be
provided: name and purpose of project, location, date, name of owner, designer, fabri-
cator, and installer, type of FML, thickness, surface area, and available written informa-
tion on the performance of the project.
1.2 FML Fabricator
The FML Fabricator shall be trained and qualified to fabricate the type of FML
to be used for the project. The FML Fabricator shall be an approved and/or licensed
Fabricator of the FML Manufacturer. A copy of the approval letter or license shall be
submitted to the Monitor.
To demonstrate an ability to fabricate FML, the FML Fabricator shall provide
the Monitor with a list of at least ____ previous fabrications, totaling a minimum of —
hundreds of thousands m 2 (millions sq. ft), completed with the same generic type of
FML. For each fabrication, the following information shall be provided: name and
purpose of project, location, date, name of owner, designer, manufacturer, and installer,
type of FML, thickness, total amount of FML fabricated, type of seaming, and available
written information on the performance of the project. Also, the FML Fabricator shall
provide information on the factory size and equipment, and daily production quantity
available.
1.3 FML Installer
The FML Installer shall be trained and qualified to install the type of FML to be
used for the project. The FML Installer shall be an approved and/or licensed Installer of
the FML Manufacturer and/or FML Fabricator. A copy of the approval letter or license
shall be submitted to the Monitor.
To demonstrate an ability to install FM!.., the FML Installer shall provide the
Monitor with a list of at least _____ previous installations, totaling a minimum of —
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hundreds of thousands m 2 (millions sq. ft). For each installation, the following infor-
mation shall be provided: name and purpose of project, location, date, name of owner,
designer, manufacturer, fabricator and leader of the installer’s crew, type of FML,
thickness, surface area, type of seaming, duration of installation, and available written
information on the performance of the project.
2 FLEXIBLE MEMBRANE LINER
2.1 Raw Materials
The FML shall be manufactured of first quality newly produced raw materials.
The use of reclaimed polymers and other materials shall not be permitted. Recycling of
materials containing reinforcing scrim shall not be permitted. Recycling scrap that does
not contain scrim may be permitted.
The FML Manufacturer shall: (i) indicate the origin of raw materials; (II) provide
a copy of quality control certificates issued by the producer of raw materials; and (iii)
provide reports on the tests conducted to verify the quality of the raw materials. These
tests should include at least:
Density (ASTM D792-66) and melt index (ASTM D 1238-79), for HDPE.
Analysis of the chemical composition of the plasticizers, for PVC.
2.2 RoLls
The FML rolls shall be designed and manufactured specifically for the purpose of
fluid containment. The FML shall be free of holes, blisters, undispersed raw materials,
and any sign of contamination by foreign matter.
The FML to be used for this project shall be mm (_ mil) thick — (mention
here the type of FML, such as HDPE; 1 -lypalon; PVC). The FML shall meet the
specifications listed in Table 1. (Note 1)
The following information shall be provided by the FML Manufacturer as an
indication of the quality of the material supplied:
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Material properties sheet, pertaining to the FML to be used for the
project, (including data regarding chemical compatibility of the FML with
contacting fluids) shall be provided. The sheet should at least include all
properties listed in Table 1. The allowable range in values of properties
listed in the sheet must meet the specifications given in Table 1. The
sheet shall provide minimum properties guaranteed by the FML
Manufacturer and indicate test methods used. Unless otherwise specified,
test methods shall be in accordance with NSF Proposed Standards.
Quality control certificates pertaining to the rolls of material delivered
to the site shall accompany the rolls. Each roll shall be identified by a
unique manufacturing number. The quality control certificate shall
include results of at least the following tests: thickness, tensile charac-
teristics, and tear resistance (also, coefficient of thermal expansion-
contraction for I-IDPE) (also: hydrostatic burst resistance, and ply
adhesion, in the case of Hypalon). Unless otherwise necessary, test
methods shall be in accordance with NSF Proposed Standards. The quality
control certificates shall be signed by a responsible party employed by the
FML Manufacturer, such as production manager, and shall be notarized.
2.2 (Continued for Hypalon)
The FML Manufacturer shall indicate the composition of roll material. The
polymeric compound shall contain at least 45% by weight of “Hypalon type 45” as the
sole elastomer. The reinforcing scrim shall be defined by the number of yarns per unit
width (eg. per meter or per inch) in each direction and by the linear density (in kg/rn, tex,
or deniers) of the yarns. The type of polymer used for the reinforcing scrim shall also be
indicated.
2.2 (Continued for unreinforced PVC)
The FML Manufacturer shall indicate the proportion by weight of plasticizers,
and the amount of volatile loss measured using ASTM 0 1203, method A. The maximum
value of the volatile loss shall be —. (Note: the NSF Proposed Standards recommend
0.7% for a 0.75 mm (30 mil) thick FML and 0.5% for a 1.15 mm (45 mil) thick FML;
values for other FML thicknesses may be interpolated or extrapolated beyond the
1.15 mm (45 mil) value).
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2.3 Blanket Fabrication
(Note: The entire section 2.3 shall be deleted if the rolls are riot fabricated into
blankets in a plant. This is usually the case for HDPE FML.)
2.3.1 Blanket Geometry
The FML shall be fabricated into blankets. Blanket sizes shall be: (i) proposed
by the FML Fabricator; (ii) consistent with the instructions (if any) given by the
Designer; and (iii) approved by the Monitor and the FML Installer.
2.3.2 Factory Seaming
The rolls shall be fabricated into the designed blanket sizes using one of the
following seaming techniques: adhesive, heat seaming, or dielectric seaming.
The overlap shall provide the minimum required seam width (as indicated
below). The seam shall extend to the edge of the sheet, so that no loose flap is present
on the top side of the blanket. A loose flap is permissible ori the bottom side of the
fabricated blanket.
The rolls shall be laid out without tension and seamed without wrinkles or fish-
mouths. If wrinkles occur within the sheet due to the seaming process, the wrinkle shall
not extend into the seamed width. Wrinkles which extend into the seamed width shall be
treated as specified in Section 3.5.7.
The overlap area to be seamed shall be free from moisture, dust, dirt, debris of
any kind, and foreign material. The fabrication area shall be in a clean, enclosed,
temperature controlled facility.
The dielectric and heat seaming devices shall be accurately monitored and
controlled at all times to effect a consistently acceptable seamed width. Dielectric bars
or wheels with ribs shall effect the full specified seam width. Space between the bar ribs
shall not be counted in the seam width.
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2.3.2 (Continued for Hypalon)
To effect a clean, bondable surface, the seam interfaces shall be cleaned with
trichiorethylene or perchiorethylene solvent before the Hypalon adhesive is applied. The
1-lypalon based adhesive product for seaming the rolls together shall be as recommended
by the Hypalon FML Manufacturer. The adhesive product shall be applied as specified by
the Hypalon FML Manufacturer with special attention to the ambient temperature and
rolling pressure.
The minimum scrim-to-scrim seam widths shall be:
Hypalon based adhesive
Heat seaming
Dielectric seaming
50 mm (2 in.)
25 mm (1 in.)
25 mm (1 in.)
The minimum seam width shall be the scrim-to-scrim seam width, plus the
selvage width.
2.3.2 (Continued for PVC)
The PVC adhesive used for seaming the rolls together shall be as recommended
by the PVC FML Manufacturer and shall not be deleterious to the PVC FML material in
any way after seaming. The adhesive product shall be applied as specified by the PVC
PML Manufacturer with special attention to the ambient temperature and rolling
pressure. The adhesive shall have been tested for longevity in contact with the PVC FML
material and its application shall result in no appreciable stiffening of the FML.
Prepared adhesive tapes shall not be used.
The minimum seam widths shall be:
PVC adhesive seaming
Heat seaming
Dielectric seaming
Unreinforced
25 mm (1 in.)
25 mm (1 in.)
20 mm (314 in.)
Reinforced
50 mm (2 in.)
25 mm (1 in.)
25 mm (1 in.)
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3 INSTALLATION
3.1 Definition of Responsibilities
All parties involved with FML installation shall attend a meeting held prior to
installation of any FML. The purpose of this meeting is to: (i) define the responsibilities
of each party (ii) establish lines of authority and lines of communication; (iii) establish
site specific quality control and monitoring procedures; and (iv) define the method of
acceptance of the completed liner. The meeting shall be documented and minutes trans-
mitted to all parties.
3.2 Surface Preparation
The upper 0.1 m (4 in.) of the supporting soil shall not contain stones larger than
25 mm (1 in.). The surface to be lined shall be rolled with a smooth drum steel or pneu-
matic roller so as to be free of irregularities, loose earth, and abrupt changes in grade.
The surface preparation shall be done by the Earthwork Constructor. The FML Installer
shall certify in writing that the surface on which the FML is to be installed is accept-
able. Thereafter, the FML Installer shall provide the necessary equipment and personnel
to maintain an acceptable soil surface during liner installation.
No FML shall be placed in an area which has become softened by precipitation
(ie, unconfined compressive strength less than 50 kPa (05 tsf)).
3.2 (Specific to surface preparation when the FML is supported on a soil liner)
Special care must be taken to maintain the prepared soil surface in areas where
the soil functions as an impermeable soil liner. The soil surface shall be observed daily
by the Monitor and FML Installer to evaluate desiccation cracking. The daily
observations shall also ascertain the effects of surface desiccation cracking upon the
integrity of the soil liner. Prior to installation of any FML, the Designer and Monitor
shall define in writing the maximum allowable crack depth and width which wifl not
significantly affect the soil liner design intent. The Monitor shall inform the FML
Installer of the requirements regarding crack depth and width. Precautions for reducing
desiccation potential (le, temporary FML cover) and crack repairs shall also be defined
by the Designer and approved by the Monitor. (Note 2)
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3.3 Handling of FML
3.3.1 Packaging
FML rolls or blankets shall be packaged and labeled prior to shipment to the
site. The label shall indicate the FML Manufacturer, FML Fabricator, type of FML,
thickness, and roll or blanket number.
3.3.2 Transportation
When transported to the site, FML rolls or blankets shall be handled by appro-
priate means so that no damage is caused. Wooden cases shall be strong enough to
withstand impacts and rough handling without breaking or splintering.
Transportation shall be the responsibility of the FML Manufacturer (if fabrica-
tion is not required, which is usually the case of l-IDPE), or of the FML Fabricator (if
fabrication is required, which is usually the case of 1-lypalon and PVC).
3.3.3 On-site Storage
Once on-site, storage of the FML is the responsibility of the FML Installer. The
FML shall be protected from direct sunlight and heat to prevent degradation of the FML
material and adhesion of individual whorls of a roil or layers of a blanket.
Adequate measures shall be taken to keep FML materials away from possible
deteriorating sources (ie, vandalism, theft).
3.3. On-site Handling
On-site handling of the FML is the responsibility of the FML Installer. Appro-
priate handling equipment shall be used when moving rolled or folded FML from one
place to another. Instructions for moving the FML shall be given by the FML Installer to
the workers and shall be approved by the Monitor.
3.3 . 5 Panel Placement
Each roll or blanket shall be redesignated with a panel number. A panel is the
unit area of in-place membrane which is to be seamed (ie, one roll may be cut into
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several panels). The FML shall be positioned on the site as shown in the layout
drawings. Instructions on the boxes or wrapping containing the FM!.. materials shall be
followed to assure the panels are unrolled or unfolded in the proper direction for
seaming. Only the panels which are to be anchored or seamed together in one day shall
be unrolled or unfolded. Care shall be exercised to not damage the FML during this
operation. All workers shall wear shoes which will not damage the FML.
Pulling FML panels shall be minimized to reduce permanent tension.
The following precautions should be taken to minimize the risk of damage by
wind during panel placement:
• No more than one panel should be unrolled prior to seaming (unless
authorized by the Monitor);
• Work shall be oriented according to the direction of prevailing winds if
possible, unless otherwise specified;
• Adequate loading on FML panels to prevent uplift by wind shall be
provided by sand bags, tires or any other means which will not damage the
FML. Along the edges, loading shall be continuous, to avoid possible wind
flow under the panels.
Any panels, which, in the judgenient of the Monitor, become seriously damaged (torn or
twisted permanently), shall be replaced. Less serious damage should be repaired
according to Section 4.4.
FML placement shall not proceed at an ambient temperature below 5°C (41°F)
or above 35°C (95°F), unless otherwise specified.
FML placement shall not be done when raining nor in an area of ponded water.
3.3.4 (Specific to HDPE)
The HDPE roll shall be installed so that there will be neither tension nor wrinkles
at the average expected temperature of the final use condition.
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3.3.4 (Specific to PVC)
Unless otherwise specified, the PVC panels shall be installed in a slack unten-
sioned condition allowing for a 5% excess in each direction (unless otherwise specified).
3.4 Considerations of Site Geometry
3.4.1 Layout Drawings
The FML Installer shall produce layout drawings of the proposed FML placement
pattern and seams prior to FML placement. The drawings shall indicate the panel
configuration and location of seams. Field seams should be differentiated from factory
seams (if any). (Note 3)
3.4.2 Anchor Trench
The anchor trench (if required) shall be constructed to the lines and width shown
on the design drawings prior to FML placement. If clay soils, susceptible to desiccation,
will be encountered in the anchor trench, no more than one days trench length shall be
excavated in advance of the FML placement. Backfilling shall proceed rapidly, unless
otherwise specified, to minimize desiccation potential of the anchor trench clay soils.
3.4.3 Installation Around Appurtenances
The FML shall be installed around any pipes, piers, concrete pits (or other appur-
tenance protruding through the FML) as detailed on the design drawings. Unless other-
wise specified, a FML sleeve or shield shall initially be installed around each appur-.
tenance, prior to the areal FML installation. After the FML has been placed and seamed,
the final field seam connection between the appurtenance sleeve or shield and the FML.
shall be completed. A sufficient initial overlap of the appurtenance sleeve shall be
maintained so that shifts in location of the FML can be accomodated.
Installation on rough surfaces such as concrete shall be carefully performed to
minimize FML damage. Additional, loosely placed FML or geotextile sections may be
used by the FML Installer as protection for the FML if approved by the Monitor. (Note 4)
All clamps, clips, bolts, nuts or other fasteners used to secure the FML around
each appurtenance shall have a life-span equal to or exceeding the FML.
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3.5 Field Seaming
3.5.1 Requirements of Personnel
All personnel performing seaming operations shall be qualified by experience or
by successfully passing seaming tests.
At least one seamer shall have experience seaming at least one hundred thousand
m 2 (1 million sq. ft.) of a FML of the same generic type as the FML used for the project
using the same type of seaming method. This master seamer shall provide direct super-
vision over apprentice seamers.
Apprentice seamers shall be qualified by attending training sessions taught by
the master seamer and performing at least two successful seaming tests under similar
weather conditions using the seaming method used for production seaming.
3.5.2 Overlapping
3.5.2 (Specific to HDPE)
The panels shall be overlapped a minimum of 75 mm (3 in.)
3.5.2 (Specific to Hypalon and PVC, Heat Seaming)
The panels shall be overlapped a minimum of 100 mm ( in.)
3.5.3 (Specific to Hypalon and PVC, Adhesive Seaming)
The panels shall be overlapped a minimum of 150 mm (6 in.).
33.3 Preparation
Prior to seaming, the seam area shall be clean and free of moisture, dust, dirt,
debris of any kind, and foreign material.
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3.5.3 (Specific to HDPE)
The seam overlaps shall be ground according to the FML Manufacturer’s instruc-
tions.
3.5.3 (Specific to Hypalon)
The seam overlaps shall be cleaned with thrichlorethylene or perch lorethylene in
accordance with the FML Manufacturer’s instructions.
k$ 4 Seaming Equipment and Products
3.5.4 (Specific to HDPE)
Each seaming unit must include thermometers giving the temperature of the
extrudate in the machine and at the nozzle.
3.5.4 (Specific to Hypalon and PVC, Heat Seaming)
The heat seaming device (hot air or hot wedge) shall include a thermometer
allowing the temperature to be monitored.
3.5.4 (Specific to 1 -lypalon and PVC, Adhesive Seaming)
The adhesive (bodied solvent compound or cement) shall be formulated in accor-
dance with the FML Manufacturer’s specifications.
33.5 Weather Conditions for Seaming
Weather conditions required for seaming are as follows: (i) no weld shall be done
below 1°C (34°F); (ii) between 1°C (34°F) and 10°C (50°F), seaming is possible if the
FML is preheated by either sun or hot air device, and if there is not excessive cooling
resulting from wind (as determined by the Monitor); and (iii) above 10°C (50°F), no pre-
heating is required. In all cases, the FML shall be dry.
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3.5.6 Seaming Procedure
Seaming on horizontal surfaces shall commence at the center of a panel side and
proceed to either end of a side (if possible) in an effort to reduce wrinkles and subsequent
fishmouths at the seam interface. The direction of seaming on slopes shall be the most
expedient direction for the type of seaming used. Seaming shall extend to the outside
edge of panels to be placed in the anchor trench.
If the supporting soil is soft, a firm substrate shall be provided by using a homo-
geneous board, a conveyor belt, or similar hard surface directly under the seam overlap
to effect proper rolling pressure.
3.5.6 (Specific to Hypalon and Reinforced PVC, Heat Seaming)
The width of the seam shall be 25 mm (1 in.) scrim to scrim. Then, the loose
upper flap shall be bonded using either a hot air gun or an adhesive (bodied solvent or
cement).
3.5.6 (Specific to Hypalon and PVC, Adhesive Seaming)
The width of the seam shall be 100 mm (4 in.) starting from the edge of the FML
placed on top (so there is no loose flap).
3.5.6 (Specific to Unreinforced PVC, Heat Seaming)
The width of the seam shall be 25 mm (1 in.) starting, if possible, from the edge
of the FML placed on top. Any loose flap shall be bonded using either a hot air gun or an
adhesive.
35.7 Procedure for Seaming Wrinkles
Fishmouths or wrinkles at the seam overlaps shall be cut along the ridge of the
wrinkle back into the panel so as to effect a flat overlap. The cut fishmouths or wrinkles
shall be seamed as well as possible, and shall then be patched with an oval or round patch
of the same generic FML extending a minimum of 150 mm (6 in.) beyond the cut in all
directions.
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3.5.7 (Specific to Hypalon and PVC)
The patch shall be bonded over its entire area, using either a hot air gun or an
adhesive (bodied solvent or cement).
3.5.8 Cap-strips
Cap-strips shall be at least 75 mm (3 in.) wide and shall be centered over the
completed seam edge. Cap-strips shall be of the same generic FML material as the liner
but without reinforcing scrim. The thickness of cap-strip shall be — mm (_ mils) (at
least 0.75 mm (30 mils)).
Cap-strips shall shall be placed on all field seams. They shall be placed only
after quality control of the original seam has been performed.
3.5.8 (Specific to 1-IDPE)
Cap-strips shall not be longer than 3 m (10 ft) long if they are not bonded over
their entire surface.
3.5.8 (Specific to Hypalon and PVC)
Cap-strips shall not be placed on a loose flap (loose flaps shall be bonded as
explained in Section 3.5.6). Cap-strips shall be bonded over their entire surface, using
hot air gun or adhesives (either bodied solvent or cement).
3.5.8 (Specific to 1-lypalon and Reinforced PVC)
Cap-strips shall be placed on all seams where the reinforcing scrim daylights: (i)
ends of rolls; (ii) tapered rolls in corners and other special locations of cells or ponds; and
(iii) places where the unreinforced selvage is too narrow (smaller than 3 mm (1/8 in.)) or
has been damaged.
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3.6 Installation of Materials in Contact with the FML
3.6.1 Granular Materials
Granular materials (ie, for FML protection or as a leachate collection system)
shall be placed by the FML Installer or Earthwork Constructor at the direct supervision
of the FML Installer in a manner so as not to damage the FML.
Placement of a granular material layer shall commence after the FML anchor
trench (if any) has been completely backfilled and compacted and the leachate collection
sump structures (if any) have been installed.
Unless otherwise specified, initial granular material placement shall be done by
placing the material at the toe of the lined slope and pushing the material up the side
slope with a light dozer (eg. D-6) or other equipment approved by the Monitor. The full
design thickness of the granular material layer shall be maintained when spreading the
material. The granular layer shall be placed over the FML before any construction
traffic is allowed. If necessary, an access ramp comprised of granular material shall be
gradually advanced over the geomembrane to the bottom of the disposal cell. The access
ramp and other highly trafficked areas shall be a minimum of 0.9 m (3 ft) thick. Rubber
tired vehicles shall not be allowed where the granular layer is less than 0.9 rn (3 ft) thick.
The layer of material shall be compacted using the dozer. The Monitor shall
obtain direct layer thickness measurements to verify conformance with design drawing
requirements.
3.6.2 Concrete
If concrete is to be placed on the FML, care should be taken to avoid all damage
to the FML. Additional layers of FML or geotextiles should be considered as protection
layers for the FML.
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3.6.3 Geotextiles
Geotextiles shall be overlapped 0.3 m (1 ft) unless otherwise specified (Note 5).
If necessary because of the wind, the overlaps can be glued together with spots of glue
(one to three per meter) (at a distance of one to three feet). In general, overlaps shall be
oriented parallel to the lines of maximum slope.
During the placement of the geotextile, care should be taken not to entrap
stones in the geotextile.
Unless specially selected for their ultraviolet light resistance, geotextiles shall
not be exposed more than seven days.
4 QUALITY CONTROL AND INSPECTION
4.1 Materials
The test reports, material properties sheets, and quality control certificates
required in Sections 2.1 and 2.2 shall be supplied to the Monitor by the FML
Manufacturer prior to fabrication (or installation if there is no fabrication).
The quality control certificates shall be reviewed by the Monitor to verify that a
certificate has been received for all rolls.
4.2 Factory Seams
(Note: The entire Section 1 •3 shall be deleted it the rolls are not fabricated into
blankets in a plant. This is usually the case for HDPE F ML.)
4bLl bispection
The Monitor shall visit the FML Fabricator’s plant and verify that:
• The plant is clean.
Ambient temperature in the plant is adequate (higher than 10°C (50°c)).
• The specified rolls are used.
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• The unreinforced selvage is wide enough (at least 3 mm (1/8 in.)).
• Seaming procedures recommended by the FML Manufacturer are followed.
Appropriate seaming equipment and adhesive products are used.
• The specified overlaps are used.
• The factory seams have no upper loose flap.
Non-destructive and destructive testing equipment is available in the
plant.
The Monitor shall also:
Observe non-destructive testing.
• Collect samples for destructive laboratory testing.
• Obtain, from the FML Fabricator, reports on quality control tests
performed on factory seams.
Obtain, from the FML Fabricator, daily reports on the plant’s production,
including number and identification of blankets, and number and
identification of rolls used to fabricate each blanket.
2.2 Non-Destructive Testing
Non-destructive testing of factory seams shall be performed by the FML
Fabricator. All factory seams shall be checked for loose flaps using an air nozzle
directed on the upper seam edge and surface to detect unbonded overlaps within the
seam. In addition, random vacuum seam testing shall be performed if required by the
Monitor. All required repairs shall be made by the FML Fabricator before the FML
blanket is packed for shipment.
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4.2.3 Destructive Testing
Destructive testing of specimens of factory seams shall be done by the FML
fabricator and by an independant laboratory designated by the Monitor.
One 0.45 m (18 in.) square sample, with a seam in the middle, shall be cut-off
from each fabricated blanket. This sample can be cut-off at the edge of a blanket, or
from an extra length of seam, in order not to make a hole. All holes, if any, remaining in
the FML from destructive seam testing shall be immediately repaired in accordance with
repair procedures described in Section 4.5.3.
Each sample for destructive seam test shall be numbered. The number and the
location where the sample was taken from the blanket shall be recorded by the Monitor.
One half of the sample shall be retained by the FML Fabricator, the other half by the
Monitor.
Tests to be performed in a laboratory designated by the Monitor include “Bonded
Shear Strength” (ie, tensile shear) and “Peel Adhesion”, as recommended in the NSF
Proposed Standards for FML. The specified values to be obtained in these tests are the
values recommended in the NSF Proposed Standards for FML for the particular type of
FML tested.
43 Transportation, Handling and Placement
Upon arrival at the site, the FML Installer and Monitor shall inspect all materials
for defects in the manufacturing process and for damage during transportation.
Materials judged by the Monitor to be severly damaged shall be rejected and removed
from the site. Minor damages and other defects shall be repaired.
The Monitor shall inspect each panel, after placement and prior to seaming, for
damage caused by placement operations or by wind. Damaged panels or portions of
damaged panels which have been rejected, as judged by the Monitor, shall be marked and
their removal from the work area recorded.
The Monitor shall also verily that the weather conditions (air temperature, non-
excessive wind, and lack of precipitation) are acceptable for panel placement, in
accordance with Section 3.3.5.
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4.4 Field Seams
4.4.1 Field Seaming Operations
The Monitor shall verify that:
• The seaming personnel have the qualifications required in Section 3.5.1.
• The overlaps meet the requirements presented in Section 3.5.2.
• The seaming area is clean, as described in Section 3.5.3.
• A hard substrate such as a board or a piece of conveyor belt is used if the
supporting soil is soft.
Seaming equipment and adhesive products are available on the site and
meet the requirements presented in Section 3.5.4.
• Weather conditions for seaming are acceptable, as required in
Section 3.5.5.
• Seaming procedures described in Section 3.5.6 are followed.
• The panels are properly positioned to minimize wrinkling and wrinkled
areas are seamed according to the procedures presented in Section 3.5.7.
• All cap-strips required in Section 3.5.8 are placed.
• Equipment for testing seams is available on site.
4.4.2 Test Seams
Test seams shall be performed to verify that seaming conditions are adequate.
Test seams shall be conducted at the Monitor’s discretion and at least two times each day
(at the beginning of the morning and the beginning of the afternoon), for each seaming
equipment or adhesive product used that day. Also, each seamer shall perform at least
one test seam each day. Test seaming shall be performed under the same conditions as
production seams. The test seam shall be at least 0.6 m (2 ft) long.
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Specimens shall be cut from the test seam. These specimens shall be — mm
(_in.,) wide (eg, 10 mm (0.5 in.) in the case of HDPE or 50 mm (2.in.) in the case of
Hypalon or PVC). Specimens shall be tested by hand in shear and peel, and shall not fail
in the joint. If a test seam fails, an additional test seam shall be immediately
conducted. If the additional test seam fails, the seaming equipment or product shall be
rejected and not used for production seaming until the deficiencies are corrected and a
successful full test seam is produced.
The Monitor shall observe all test seams. A sample from each test seam shall be
retained and labeled with the date, ambient temperature, number of seaming unit,
seamer, and pass or fail description. One half of the sample shall be given to the FML
installer for subsequent laboratory testing and the other half retained by the Monitor.
4.4.3 Non-Destructive Seam Testing
All field seams shall be non -destructively tested over their full length. Each
seam shall be numbered or otherwise designated. The location, date, test unit, name of
tester, and outcome of all non-destructive testing shall be recorded by the Monitor.
The Monitor shall observe all testing. Testing shall be done as the seaming work
progresses, not at the completion of all field seaming. All defects found during testing
shall be numbered and marked immediately after detection. All defects found shall be
repaired, retested and remarked to indicate completion of the repair and acceptability.
4.4.3 (Continued for HDPE)
The test unit shall be a vacuum test unit or an ultrasonic test unit.
4.4.3 (Continued for Hypalon and PVC)
The test unit shall be air lance or vacuum test unit.
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4.4.4 Destructive Seam Testing
Destructive seam testing involves cutting out a sample of an existing seam for
the purpose of verifying seam conditions through laboratory testing. Unless otherwise
noted, destructive seam testing shall not be performed except as directed in Section 5.4.
The destructive testing specimen shall be a 0.45 m (18 in.) square sample with
the seam in the middle.
Each destructive seam test sample shall be numbered. The sample number, seam
number, location of sample along the seam, and reason for the destructive seam test
shall be recorded on the test sample by the Monitor. One half of the test sample shall be
retained by the FML. Installer, the other half by the Monitor.
All holes remaining in the FML from taking destructive seam sample shall be
immediately repaired in accordance with repair procedures described in Section 4.5.3.
The new seams in the repaired area shall be tested according to Section 4.4.3.
Destructive seam test samples shall be stored and shipped in a manner which will
not damage the test sample.
Tests to be performed in a laboratory designated by the Monitor include “Bonded
Shear Strength” (le, tensile shear) and “Peel Adhesion”, as recommended in the NSF
Proposed Standards for FML. The specified values to be obtained in these tests are the
values recommended in the NSF Proposed Standards for FML for the particular type of
FML tested.
44.5 VerifIcation of Seams in Special Locations
All seams in special locations shall be non-destructively tested if the seam is
accessible to testing equipment. If the seam cannot be tested in-place, but is accessible
to testing equipment prior to final installation, the seam shall be non-destructively
tested prior to final installation (eg, seams around pipes and appurtenances). The
Monitor shall observe all seam testing operations. If the seam cannot be tested in-place,
nor prior to final installation, it shall be observed by the Monitor and FML Installer, for
uniformity and completeness.
The seam number, date of observation, name of tester, and outcome of the test
or observation shall be recorded by the Monitor.
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All defective seams shall be promptly repaired, retested and remarked to
indicate completion of the repair.
4.5 Defects and Repairs
4.5.1 Identification
All seams and non-seam areas of the FML shall be inspected for identification of
defects, holes, blisters, undispersed raw materials and any sign of contamination by
foreign matter.
The surface of the FML shall be clean at the time of inspection. Brooming
and/or washing of the FML surface shall be required if the amount of surface dust or mud
inhibits inspection.
*J.2 Evaluation
Each suspect location both in seam and non-seam areas shall be non-
destructively tested using the methods described in Section 4.4.3. Each location which
fails the non-destructive testing shall be marked and repaired.
4.53 Repair Procedures
Defective seams shall be repaired by reseaming or applying a cap-strip. Tears or
pinholes shall be repaired by seaming or patching. Blisters, larger holes, undispersed raw
materials, and contamination by foreign matter shall be repaired by patches. Each patch
shall be numbered. Patches shall be round or oval in shape, made of the same generic
FML, and extend a minimum of 150 mm (6 in.) beyond the edge of defects.
4.5.4 Verification of Repairs
Each repair shall be non-destructively tested using the methods described in
Section 4.4.3. Tests which pass the non-destructive test shall be taken as an indication
of an adequate repair. Failed tests shall be reseamed and retested until a passing test
results. The Monitor shall observe all non-destructive testing of repairs and shall record
the number of each patch, date, location, patcher and test outcome.
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4.6 Documentation
4.6.1 Material Quality Control Certificates
The quality control certificates pertaining to raw materials and manufactured
FML rolls required in Sections 2.1 and 2.2 shall be provided by the FML Manufacturer to
the Monitor prior to installation. The Monitor shall review the test results for
completeness and for compliance with the required minimum properties for both the raw
materiais and manufactured FML rolls. Materials and rolls which are in non-compliance
with the minimum required properties shall be rejected.
4.6.2 Surface Preparation Certificate
The FML tnstaller shall provide the certification of acceptance of surface
preparation to the Monitor prior to any FML installation. Thereafter the FML Installer
shall provide the Monitor written acceptance daily for the surface to be covered by FML
in that days operations.
4.6.3 Daily Fabrication Reports
The FML Fabricator shall provide the Monitor with daily reports addressing: Ci)
the total amount of FML seamed; (ii) identifiers of rolls and fabricated blankets; (iii)
quality control tests of materials used during the day; (lv) seaming equipment and
products used; (v) names of seamers; and (vi) seam testing performed. The Monitor shall
visit the FML Fabricator’s plant and independently record observations of daily
fabrication activities, including all testing performed.
4.6.4 Daily Field Installation Reports
The FML Installer shall provide the Monitor with daily reports of: (i) the total
amount and location of FML placed; (ii) total amount and location of seams completed
and seamer and Units used; (ui) changes in layout drawings; (iv) results of test seams; Cv)
location and results of non-destructive testing; (vi) location and results of repairs and;
(vii) location of destructive test samples.
The Monitor shall record daily all activities of the FML installation, which shall
include but not be limited to:
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• receipt of the written daily acceptance of surface preparation from the
FML Installer;
• observations of all FML placement activities and record of defects caused
during transportation and handling;
• observations of test seams, including seaming unit number or
identification of adhesive products, names of seamers, weather conditions
and results;
• observations of anchor trench excavation, backfilling and compaction;
• observations of field seaming operations, including weather conditions,
cleaning, overlaps, rate of seaming, names of seamers and units used;
• observations of seams around appurtenances, and connection to
appurtenances;
• observations of non-destructive seam testing, including testing location,
location of defects and testing unit used;
• observations of repairs and retesting, including locations, name of
repairer and seaming equipment or product used.
5. PERFORMANCE REQUIREMENTS AND ACCEPTANCE OF INSTALLATION
5.1 Guarantees
The FML Manufacturer shall guarantee the FML materials to be free of defects
for a period of — years after manufacture.
The FML Fabricator shall guarantee the factory seams to be free of defects for
a period of — years after fabrication.
The FML Installer shall guarantee the installed FML and field seams to be free
of defects for a period of — years after installation.
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5.2 Performance Expectations
It is expected that the FML installation will perform satisfactorily for a period
of not less than — years. The intent of the FML is to minimize the migration of fluids to
the adjacent subsurface soils and to ground water and surface water. Performance of the
FML will be partially evaluated by observations and testing of the long term monitoring
system.
5.3 Long Term Monitoring
5.3.1 Exterior Monitoring System
It shall be the responsibility of the Owner or Owner’s representative to observe
and test monitor wells exterior to the cell or impoundment area for compliance with the
permitted monitoring program. The presence of significant levels of contaminants in
these exterior monitoring wells may be judged to indicate non-performance of the FML
installation.
53.2 Leak Detection System
If the cell or impoundment design incorporates a leak detection system below or
outside of the FML., it shall be the responsibility of the Owner or Owner’s representative
to monitor the leak detection system at regular intervals. Detection of leaks by the leak
detection system may be judged to indicate non-performance of the FML installation.
533 Leachate Collection System (Specific to Land Disposal Cells and Waste Piles)
If a leachate collection system is incorporated into the design, it shall be the
responsibility of the Owner or Owner’s representative to monitor the leachate collection
system and remove leachate at design levels or designated intervals. Failure to maintain
design levels or pumping intervals may negate FML performance guarantees.
$ 3.4 Coupon Monitoring Program
A coupon monitoring program shall be a part of the long term monitoring of
durability of the FML and FML seams. Coupons (small samples of the FML with and
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without seam) shall be buried at the disposal site under the same construction conditions
and shall be placed for ready retrieval at construction intervals to be determined by the
Monitor.
5.4 FML Liner Acceptance
The FML liner shall be accepted by the Monitor when: (1) the installation is
finished; (ii) all documentation of installation is completed; and (iii) verification of the
adequacy of all field seams and repairs, and associated testing is complete.
A passing test seam shall be an indicator of the adequacy of the seaming unit and
seamer working under prevailing site conditions, but not necessarily an indicator of seam
adequacy. A passing non-destructive test of seams and repairs shall be taken to indicate
the adequacy of field seams and repairs. If the laboratory tests of the field test seams
fail, they shall be taken as an indicator of the possible inadequacy of the entire seamed
length corresponding to the test seam. Destructive test portions shall then be taken by
the FML Installer at locations suggested by the Monitor and the same laboratory tests
required of test seams shall be performed. Passing tests shall be taken as an indicator of
adequate seams. Failing tests shall be an indicator of non-adequate seams and all seams
represented by the destructive test location shall be repaired with a cap-strip. The cap-
strip shall be non-destructively tested and repaired, as required, until adequacy of the
seams is achieved.
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NOTES
Note I Table 1 should list the required properties of the FML, as determined by the
Designer. Table 1 can be presented in a way similar to the tables of material
properties presented in the NSF proposed standards.
Note 2 FML, such as 10 ml! polyethylene, or other available FML may be used for
temporary protection. A temporary FML should be overlapped 0.3 m (1 ft) and
does not need to be seamed. The temporary FML may remain in place under
the design FML. Crack repairs may Consist of re-wetting, if a sufficient time
is available for crack healing, or brooming dry powdered bentonite onto the soil
surface to fill the cracks.
Note 3 In general, seams should be oriented parallel to line of the maximum slope. In
corners and odd shaped geometric locations, the total length of field seams
should be minimized. No seams should be placed at the toe but should be a
minimum of 1.5 m (5 ft) away from the toe toward the inside of the cell or
impoundment.
Note 4 Additional, loosely placed FML or geotextile sections may create a potential
path for liquids between the FML and the supporting soil, which may be
detrimental, especially if the supporting soil is a liner.
Note 5 Specifications regarding geotextiles (including plastic nets) used as drains
should be prepared by the Designer.
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APPENDIX
DEFINITION OF TERMS
Designer - The organization or person who generated the
design drawings and plans of the FML system
including the supporting soil.
Earthwork Constructor - The organization who is responsible for the
preparation of the surface on which the FML
is to be installed; also the party responsible
for placing the granular materials over the
installed FML.
FML Fabricator - The organization responsible for production of
FML blankets from FML rolls.
FML Installer - The organization responsible for field unroll-
ing, placing, seaming and other site aspects of
the FML Construction.
FML Manufacturer - The organization responsible for production of
FML rolls from raw materials.
Inspector - A person who observes the FML construction
but is not responsible for the monitoring,
testing or documentation.
Monitor - The organization or person independent of the
FML Manufacturer, Fabricator and Installer
that is responsible for observing and docu-
menting most activities and testing and
approving Certain other activities relating to
FML construction.
Owner - The organization or person that owns the
hazardous waste disposal facility.
Regulatory Authority - The organization responsible for issuing a
permit for the completed waste disposal
facility.
Specifier - The organization or person who generated the
specifications for the FML construction.
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ASSESSMENT OF TECHNOLOGY FOR CONSTRUCTING AND
INSTALLING COVER AND BOTTON LINER SYSTEMS
FOR HAZARDOUS WASTE FACILITIES
EPA Contract No. 68-02-3174; Work Assignment No. 109
INTERVIEW NO. A-1O
Weston Designers, Consultants: Amir A. Metry TRW: John F. Metzger
West Chester, PA 215-692-3030
January 31, 1983
Summary
• There is often a conflict between developing a ‘real world” solution
and meeting a regulatory requirement. The most suitable approach is
to use the best possible design without regard to artificially set per-
formance standards.
• No guarantee can be made that an engineered system will perform ade-
quately over a very long design life in excess of perhaps 20 years.
Even where every conceivable precaution is taken, including extensive
overdesign, there is an inherent statistical risk that cannot be over-
come completely.
• Liner compatibility tests may not correlate well with field conditions.
The tests are, however, useful for comparative ranking of candidate
liners for specific applications.
Background
Weston has a number of facilities in the design and construction phase
for disposal of hazardous wastes or low level nuclear wastes. Dr. Metry has
worked directly with many of these and other facilities, and has considerable
field experience on liner design. Because ofa time constraint, the discussion
with Dr. Metry was very brief and primarily centered on the most relevant and
controversial issues pertaining to liner installation.
Liner Installation
• There is a certain statistical risk associated with every liner system
such that a facility cannot be developed that will succeed under all cir-
cumstances. However, catastrophic failures can be largely eliminated.
• Most obvious failures occur within the first several years after a
facility is constructed, and many of these result directly from inade-
quate design and inadequate quality control during installation. How-
ever, while any initial absence of failure provides no measure of the
probability of failure over a future period, this can provide some
assurance that there are no gross inadequacies in the system.
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Interview No. A-lU
Weston Designers, Consultants
Page 2
• While compatibility test results rarely correiate well with field con-
ditions, these tests are a useful tool to establish general, compara-
tive rankings between candidate liner materials. Better results can
be had by lengthening the period of the test, but cost considerations
nearly always constrain the time period to something much less than
desired.
• A geotextile can be used where the liner requires additional structural
support. This approach also permits better analysis of the adequacy of
the various materials of the liner system to carry out the functions
assigned to or expected from them.
• The preferred method of field seaming is by application of heat to the
overlapped panels with an extrudate sandwiched in between. Adhesive
seams using solvents are less desirable because of possible excessive
solvent on the sheets which are being joined.
Liner Caps
• A typical cap system might involve the following successive layers on
top of the waste pile: soil, geotextile, more soil, clay or geomem-
brane barrier, a thick geotextile drain, gravel (possibly 18 inches),
and topsoil to support vegetation.
• Subsidence normally cannot be eliminated, only reduced by good practices
of placing and compacting wastes into the facility.
• It is probably not possible, nor is it always desirable, to construct a
cap requiring no maintenance. A more economical approach might be to
construct the cap to last a short period and replace it repeatedly as
needed.
• There can be some conflict between developing a ‘real world” solution
and meeting a regulatory requirement. Construction of caps provides a
suitable example. At a nuclear waste disposal facility, a cap was re-
quired to last 1Q00 years. No such performance guarantee is possible
under any circumstances, but in this case, the cap could be developed
to have an extraordinary, though not fully known, service life. This
was possible because the contained material was nearly homogeneous and
could be stabilized to greatly minimize subsidence.
• A larger market demand is expected for cover systems than for bottom
liners because of Superfund-related remedial work being done at old
dump sites.
Perspectives on Regulations
• The preamble to EPA’s interim final land disposal regulations establishes
the appropriate philosophy. It correctly asserts industry’s respon-
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Interview No. A-lO
Weston Designers, Consultants
Page 3
sibility to dispose of their waste materials in an environmentally
acceptable manner, but equally important, places a time limit on that
responsi bill ty.
• Performance standards are a good approach to regulating •facilities
because failures can be reasonably defined. Most of the requirements
of performance standards would be site-specific, but some reasonable,
general requirements might include:
- Dye testing of the facility before it begins operation (or by use
of some other tracer).
- A structure paralleling the NPDES system for surface waters except
that, in this case, compliance would be determined by a system of
monitoring wells (although it is important to note that leachate
can unexpectedly bypass monitoring wells).
• All parties involved in developing a land disposal facility are partial-
ly liable for its performance. However, court interpretation of liabi-
lity has most often been by the “deep pockets” philosophy - the party
having the most money is assigned the principal burden of payment.
• EPA sometimes sets goals that are unattainable. The only option for
design engineers then is to develop the best possible system regardless
of how it compares with some ideal or otherwise artificially set goals.
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ASSESSMENT OF TECHNOLOGY FOR CONSTRUCTING AND
INSTALLING COVER AND BOTTOM LINER SYSTEMS
FOR HAZARDOUS WASTE FACILITIES
EPA Contract No. 68-02-3174; Work Assignment No. 109
INTERVIEW NO. A-li
Slurry Systems: Frank Ziamal TRW: Masood Ghassenii
Gary, IN 219-949-0561
2 February 1983
Summary
• Laboratory test results indicate that even the so—cailed contaminant-
resistant bentonite is an inadequate liner material for hazardous
wastes. Prolonged contact with leachate results in gradual increase
in permeability and hence, ultimate failure.
• Provided that it is designed and constructed properly, bentonite is
an excellent material for lining potable water impoundments (where the
harsh leachate conditions are absent).
• Asphalt emulsion slurry walls have proven very effective in containing
lateral escape of pollutants from hazardous waste disposal sites.
Several large-scale systems handling chlorinated hydrocarbon, pesti-
cide manufacturing and other hazardous wastes are in successful opera-
tion.
• R&D effort at the company has resulted in the development of a soon-
to-be marketed asphalt emulsion spray-on liner system which, based on
laboratory tests, is believed to be superior to most currently avail-
able flexible membrane liners. The spray-on system will consist
of two 1/16-inch polyurethane layers which are sprayed onto a fiber-
glass mesh support reinforcement. The two liner layers are separated
with a layer of porous material for the purpose of leachate collection
and removal. The elimination of the field seams is considered the
single big advantage of the spray-on system.
• Educating customers to use competent designers and engineers and to
demand quality work is a better approach to ensuring liner performance
than regulations which cannot be made specific enough to cover the
spectrum of field conditions requiring site-specific solutions. In
the past, many of the EPA regulations have been written by individuals
who have lacked the necessary technical background and who generally
do not stay on an assignment long enough to gain experience and to
become fully familiar with a specific subject matter.
• R&D effort should emphasize development of a better understanding of
the mechanism of interactions between bentonite and heavy metals and
organics in the leachate.
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Interview No. A-li
Slurry Systems
Page 2
Background
Slurry Systems, a division of Thatcher Engineering, provides design
and construction/installation services for bentonite liners for potable
water impoundments and asphalt emulsion slurry walls for hazardous waste
disposal sites. Slurry Systems had sales of about $3 million last year
and expects higher sales this year. The annual sales for the parent com-
pany, Thatcher Engineering, are about $20 million. Slurry Systems has
branch offices/licensees at five different locations in the U.S., and in
two locations in Canada. The company has been in business since 1974
and has considerable on-going R&D effort aimed at developing new formula-
tions and equipment for slurry wall and liner applications. It has de-
veloped a special urethane spray-on liner formulation which it expects to
actively market in the future and which it believes will prove superior
to the present-day factory-fabricated, field-installed flexible membrane
liners. The company prefers to be responsible for both design and instal-
lation as a means of providing better assurance for the good performance
of the final product and, hence, reducing its potential liability.
The objective of this interview, which was carried out via telephone,
was to expand the data base on clay and admix liners. The following
topics were discussed: bentonite liners, slurry walls, asphalt emulsion
spray-on liners, perspectives on regulations, and R&D needs.
Bentonite As a Liner Material
• Based on laboratory tests conducted by Slurry Systems, bentonite is
not considered a suitable liner material for hazardous waste disposal
facilities. Regardless of pretreatment to impart contaminant resis-
tance properties, the treated bentonite will not withstand, over the
long term, the harsh leachate conditions. Laboratory tests in which
bentonite treated with carboxy methyl cellulose was kept in contact
with actual leachate having a pH of 5.2 indicated a gradual loss of
permeability after 3 to 4 years. These and similar tests in which
bentonites from major commercial suppliers have been used indicate
that the increase in permeability is “just a matter of time”. Slurry
Systems thus questions the statements and data presented by certain
bentonite suppliers indicating that bentonite treated with polymeric
(e.g., methyl, ethyl, or higher polymers) and other proprietary for-
mulations will withstand extended contacts with actual or simulated
leachates without loss of impermeability. Even though Slurry Systems
would stand to benefit from any large-scale use of bentonite as a
liner material, it will not recommend or use bentonite for lining
hazardous waste disposal sites.
• Based on laboratory tests, it is postulated that the carbonic and
organic acids present in the leachate cause the release of adsorbed
water, and hence, collapse of the bentonite platelets and increase in
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Interview No. A-il
Slurry Systems
Page 3
permeability. The test results also indicate that chlorinated hydro-
carbons and aromatic compounds such as benzerie and its derivatives
are most destructive to the bentonite structure. Higher valency
compounds such as sulfate and sulfite also promote degradation of
bentonite (but not of kaolonite or illite which do not expand to the
same extent as sodium montmorillonite).
• Bentonite can provide an effective liner material for potable water
impoundments where harsh leachate conditions of disposal sites are
non—existent. Slurry Systems has extensive experience in the use of
bentonite for this purpose, and has developed and patented special
machines for installing such bentonite liners.
• Bentonite liners for potable water impoundments should be designed
for the most permeable conditions existing in the support soil at the
site. Typically, 2.7 lb of bentonite per square foot is mixed with
the topsoil of K = 1 x i0 cm/sec, and compacted to a depth of 6
inches. If the topsoil is not suitable (e.g., due to high organic
content), clean soil (or preferably sand) brought in from off-site can
be used in preparing the bentonite admixture. Using special machines,
fresh water is metered in to establish proper moisture level (14-16
percent) during mixing. Compaction is very critical to liner perfor-
mance and achievement of a 90 percent Proctor density is considered
desirable.
Asphalt Emulsion Slurry Walls
• When natural geological substrata provide an effective barrier against
downward (but not lateral) movement of pollutants at a disposal site,
the lateral pollutant migration can be arrested via slurry walls con-
structed around a disposal site. Slurry Systems has successfully
used asphalt emulsion slurry walls for such a purpose in several large-
scale applications. The formulation consists of a minimum of 30 per-
cent asphalt emulsion, minus 60 mesh graded material, anionic surfac-
tants and other proprietary additives. This slurry, which sets in 4
to 6 hours, has been found to exhibit excellent chemical compatibility
properties both in laboratory tests and in full-scale applications.
In a laboratory test, a 4-inch thick column of asphalt emulsion slurry
was placed under a 40-inch column of free-standing gasoline for more
than one year with no gasoline detected as having passed through the
test section.
• To be effective, the slurry wall should extend down to and make con-
tact with the bottom liner (the natural clay). The slurry wall thus
may be as much as 100 feet deep, although 40 to 50 feet have been more
common in cases designed by Slurry Systems. The construction of the
asphalt emulsion slurry wall does not require digging (a substantial
advantage), and the soil is merely displaced in-situ using special
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Interview No. A—li
Slurry Systems
Page 4
machines which deliver the slurry behind a beam operated under 25 tons
of force. The width of the slurry wail is usually between 3 to 6
inches.
• The following three large-scale asphalt emulsion slurry walls, which
have been constructed by Slurry Systems, have performed very success-
fully:
- A site in suburban Detroit handling chlorinated hydrocarbon waste.
This site is owned and operated by Chemical Recovery Company.
- A “Class-Il” hazardous waste disposal site in Pasadena, Texas.
This site is owned and operated by Western Refuse of Texas.
- A liquid waste containment site in Richmond, California, for
Chevron Chemical Company’s Ortho Division. This site, which con-
sists of 5 lagoons receiving pesticide manufacturing wastes, has
been surrounded by a single slurry wall. To date, the data from
monitoring wells have indicated very satisfactory performance.
(For further information on this site, contact Mr. Heino Jogis
of Chevron at 415-231-4453.)
Asphalt Emulsion Spray-on Liners
• Although not yet a marketed technology/product of Slurry Systems, the
company has carried out R&D effort, including extensive testing, and
has developed an asphalt emulsion spray-on liner which it considers
superior to most currently available flexible membrane liners. The
special formulation has, as its ingredients, elastomers, dilutors,
fillers, urethane, polybutylene, and a number of other proprietary
additives which have been developed.
• The following installation procedures are recommended for the asphalt
emulsion spray-on liner:
- Excavate supporting soil as necessary and compact to about 80
percent proctor density.
- Spread a fiberglass mesh on the top of the prepared surface.
- Spray on a liner layer of about 1/16-inch thick onto the fiber-
glass reinforcement.
- Place 18 inches to 2 feet of graded material (e.g., sand with
permeability of about l0 cm/sec) which will also constitute the
leachate collection system and will contain the necessary piping.
- Place a second layer of fiberglass mesh on top of the graded
material and spray on a second coat (1/16-inch thick) of liner
onto the fiberglass reinforcement.
- Cover the top liner with about 6 inches of soil.
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Interview No. A—li
Slurry Systems
Page 5
• Among the advantages claimed for the spray-on system are the following:
- Elimination of field seaming which has been a major installation
problem and the cause of most failures with other flexible membrane
liners (in the spray-on system, the fiberglass mesh widths are over-
lapped by 6 inches).
- Quick setting properties; the spray-on material sets in about 1/2
hour.
- Resistance to degradation by sunlight and chemical action. In a
laboratory test, a 1-inch thick specimen has been kept submerged in
a gasoline/naphtha mixture for over one year with no noticeable
change in color to indicate degradation.
- Excellent puncture resistance property. In small scale tests,
operation of the equipment on the liner has caused no apparent
damage. Tests have also indicated a puncture resistancy of about
250 lb per square inch.
Perspectives on Regulations
• Educating customers to use competent designers and installers and to
demand quality work is a far better approach to ensuring adequate liner
performance than issuing more bureaucratic regulations. No regulations
can be responsive to the wide range of site-specific conditions which
are encountered in practice.
• A major problem with the EPA regulations in the past has been that they
were written by administrative personnel who lacked experience and
were not fully familiar with the “real world” problems and the avail-
able approaches for addressing such problems. There is also a very
high staff turn-over at regulatory agencies, and this prevents the in-
dividuals drafting regulations to accumulate and apply experience in
connection with a specific subject matter.
Research and Development Needs
• Reflecting the interest of Slurry Systems, R&D efforts are suggested
for assessing the impact of heavy metals and aromatics on properties
of bentonite, including the elucidation of the mechanism and chemistry
involved.
Miscellaneous
• Mr. Zlamal indicated that he will forward to TRW, for use in the subject
study, laboratory test results and technical data to support the claims
and assertions discussed in this interview report. (Some research
materials have been mailed to TRW.)
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ASSESSMENT OF TECHNOLOGY FOR CONSTRUCTING AND
INSTALLING COVER AND BOTTOM LINER SYSTEMS
FOR HAZARDOUS WASTE FACILITIES
EPA Contract No. 68-02-3174; Work Assignment No. 109
INTERVIEW NO. A—12
B.F. Goodrich, : T.R. Ward TRW: John F. Metzger
Fabricated Polymers Division 614-373-6611
Marietta, OH
February 4, 1983
Surna ry
• Most installation contractors use unskilled workers for field operations,
including constructing seams. Few problems result though because while
the work must be done exactly, it is not difficult and can be quickly
learned using skilled supervision.
• No method of checking field seams is completely adequate. Nondestruc-
tive tests such as by the vacuum method or air lance give good results,
but these only indicate the seal and not the seam strength. To test
for seam strength, a sample of the material must be taken, but this
then requires a patch whose integrity is never fully certain.
• Due to potential liability, the manufacturer of synthetic membranes has
an interest in ensuring adequate use of his product. However, this can
be frustrated by the general lack of information that is often avail-
able for a particular site and the lack of design expertise often
represented on the manufacturer’s staff. Probably the best approach
is to deal with reputable firms as much as possible.
Background
B.F. Goodrich manufactures, fabricates, and installs reinforced CPE and
Hypalon; and manufactures, subcontracts fabrication, and installs PVC and non—
reinforced CPE. There are a number of advantages for a single company to
handle the full range of liner operations; however, the overall industry is
highly competitive, requiring Goodrich to supply fabricators or installation
contractors other than their own.
The purpose of the interview was to determine the company’s perspectives
on installation problems associated with synthetic membrane liners, including
technical and non-technical problems.
Perspectives on Liner Installation Problems
• Each land disposal project can develop its own unique installation
problems, many of which cannot be anticipated. Therefore, individuals
4-108
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Interview No. A-l2
B.F. Goodrich
Page 2
with installation expertise are needed on-site to address problems as
they develop. The attitude of workers involved in the installation is
likewise important.
• A few firms that both fabricate and install liners use the same person-
nel for both operations. However, most firms install liners using un-
skilled workers that are locally available. Due to high transportation
costs and the fluctuating availability of installation jobs, no other
approach to doing business is cost competitive.
• Unskilled workers must be closely attended to initially. But the field
operations are not difficult, and once trained, the laborers generally
do a good job. The capability of the foreman to communicate with his
workers is particularly important for ensuring an adequate job.
• Most field seams are made by an adhesive method, except HDPE which is
made by applying heat to the overlapped sheets with an extrudate of the
liner material sandwiched in between. Weather conditions must always
be considered during seaming operations. Some adhesives will blush
when the humidity is high, and temperature can cause the solvent to
volatilize at a less than optimal rate. If the ambient temperature is
too cold, the seam may set too slowly; if too hot, the solvent may eva-
porate too quickly, resulting in too little residence time for the seam
to “bite 11 deep enough into the two materials.
• While factory seams are generally one inch in width, field seams are
made wider, usually 4 to 6 inches, to increase the opportunity for a
continuous connection to be made.
• Several methods should be used to check field seams. An air lance only
establishes whether there is a leak across the interface. Structural
weaknesses are not detected. Cut samples tested for peel and shear
strength can more fully evaluate the seams, but only on a limited spot
basis since this is a destructive test method, and the integrity of a
patch is as uncertain as the integrity of the seam. To minimize the
number of patches, cut samples are sometimes taken at the end of the
sheet. If the seaming crews know where the sample will be taken, they
may do an especially careful job in that section. A sampling program
should be developed to provide a representative sampling.
• All methods of testing field seams provide some assurance of their in-
tegrity, but none is fool—proof. Simple visual inspection can provide
an excellent check on more sophisticated test methods.
• Puckers, wrinkles, and all questionable areas within a seam should be
patched. It is common practice, however, to leave wrinkles in the liner
to allow for contraction and compaction.
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Interview No. A-12
B.F. Goodrich
Page 3
• Precautions should be taken where nutgrass is indigenuous to the region.
This plant can grow through most liners and must be eliminated by
sterilizing the ground below the facility.
• Geotextiles can be useful in areas where there are problem soils.
• Some failures blamed on inadequate installation are actually the result
of operating practices that were not designed for. A common example
is emergency discharge of chemicals during a plant upset.
Installation Problems Related to Institutional Relationships Between
Involved Parties
• Manufacturers of synthetic membranes can be somewhat vulnerable to
claims of liability because often the manufacturer is the only involved
party that has large assets worth suing for. Therefore, the manufac-
turer’s best interests are served by monitoring his product to ensure
no abuses occur. If there is a high enough potential for misuse, the
manufacturer may choose to not bid the job. However, there is a deli-
cate balance between the competing interests of maximizing profits by
increased sales and taking reasonable precautions to avoid liability or
other problems at a future time.
• Goodrich benefits by its vertical organization of manufacturer/fabrica-
tor/installer in several ways. Most importantly, the company is less
susceptible to legal claims and can better defend itself against these
because tighter control can be maintained on operations that are nor-
mally beyond the company’s influence. Each of the separate operating
sections communicates well, and information concerning the problems at
a particular job site are therefore available first-hand.
• Goodrich fabricates only reinforced CPE and reinforced Hypalon. The
following quality control checks are made:
- Sections of joined panels are tested at the start of the seaming
operation because this is the time when the process is most likely
to not be adjusted properly.
- Three tests are made on seam samples. The fabric to fabric overlap
of the joined sheets is inspected, checking that there is a minimum
of one—inch scrim overlap. Shear and peel strength are tested.
- A final check of all seams is made by air lancing.
• Goodrich also subcontracts fabrication of its liners to other companies.
Samples of the seams are submitted for testing. The frequency depends
upon the fabricators’ experience, equipment, and the use of the liner.
• While Goodrich manufactures, fabricates or subcontracts fabrication,
and installs liners, roll goods are also sold to fabricator/installers
4-110
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Interview No. A-12
S.F. Goodrich
Page 4
and fabricated blankets are also sold to installers. Goodrich often
encourages its larger volume roll goods customers to become approved
fabrication subcontractors. Goodrich can then work more closely to
insure adequate quality control. When fabricated blankets are sold
directly to an installation contractor, there is generally less oppor-
tunity to influence the use. Most installation contractors, however,
are receptive to manufacturers input.
• Goodrich may request the owner of a proposed facility to make design
changes if a high probability of failure is suspected. These judge-
ments, however, can be difficult to make. Site—specific information,
for example geological data, is often not readily available. Unless a
site is grossly inadequate, a judgement has to be based on less precise
information. Also, Goodrich often has only limited design expertise
in comparison with consulting engineers making Goodrich’s position
difficult to argue. But not all consultants are a iare of all design
factors. For example, it is not unusual to request a liner having
characteristics that do not exist. Therefore, if the design is judged
seriously inadequate and if changes are not agreed to, Goodrich may
choose not to bid it.
• On 1arge installations, the liner installation is generally done under
subcontract to a general contractor who has been awarded the entire
project (including earthwork). In some cases, the general contractor
may elect to handle the installation. Goodrich will provide technical
support including supervision if requested. In rarer cases, liner
material has been supplied to a general contractor with no support
other than written instructions. Such an arrangement has not always
worked well.
Miscellaneous
• Calendered products cannot be guaranteed to be free of pinholes. The
number depends on the manufacturing process used and the materials.
However, the materials that are most susceptible to pinholes are the
same materials most commonly laminated. It is unlikely that pinholes
of adjacent plies will align to form a continuous path for leachate or
other fluids to cross.
• While no hard data can be cited, it is believed that loss of leachate
or other fluids through pinholes is insignificant, and that the pinhole
issue itself is therefore not significant as well.
• Caps are always subject to pressures of subsidence. However, the main
purpose of a cap is usually to keep moisture out of the waste pile to
minimize leachate generation. Caps usually perform well if the subsi-
dence is not dramatic.
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Interview No. A—12
B.F. Goodrich
Page 5
• Compatibility testing is done by Goodrich as part of its research and
development and in support of customers. Most tests involve exposing
liner materials to varying concentrations of standard chemical solu-
tions such as acids, bases, and selected organic solvents. Immersion
tests using a sample of the customer’s synthesized or actual wastes are
also done. An actual waste sample is preferred and is sometimes the
only reliable approach when the composition of the waste is not known.
Unknown waste compositions are often encountered, and this creates
problem in assessing compatibility.
• Most companies have similar programs for bringing new products onto the
market. However, while extensive testing is involved, every field con-
dition cannot be anticipated nor simulated.
• The only warranty issued by Goodrich is for weathering of Hypalon. No
other guarantee is practical since the end use service conditions can
never be completely quarariteed.
• The overall regulation of hazardous wastes is appropriate but there is
a tendency to adopt unreasonable standards (as was the parallel case
for wastewater where zero discharge was made a goal). A more realistic
determination is needed of goals that are both attainable and represent
an appropriate balance between risk and cost efficiency.
• Performance standards for hazardous waste facilities is probably an un-
workable approach. The boundaries of a properly functioning system
would have to be defined arbitrarily. An unreasonable financial risk
would then be presented to a contractor trying to construct a system
because many of the factors contributing to failure, including opera-
tion, are outside his control. Bids would be made strictly on the basis
of risk management, and the average bid price would increase dramatical-
ly. Many reputable firms would likely withdraw from the liner business.
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ASSESSMENT OF TECHNOLOGY FOR CONSTRUCTING AND
INSTALLING COVER AND BOTTOM LINER SYSTEMS
FOR HAZARDOUS WASTE FACILITIES
EPA Contract No. 68-02-3174; Work Assignment No. 109
INTERVIEW MO. A-l3
Pantasote, Inc.: Larry Kamp TRW: John F. Metzger
Passaic, NJ 201-777—8500
February 2, 1983
Summary
• A manufacturer of flexible membrane liners (FMLs) has a clear interest
to involve himself fully with the customer and all other parties using
his product. Warranties and court decisions have largely placed res-
ponsibility for liner failures on the manufacturer, requiring him to
protect himself.
• Pinholes can form by several mechanisms during calendering of a liner
material. Recycling scrap material is one mechanism, but this practice
is not widespread and may even be acceptable in very limited applica-
tions (nonhazardous waste facilities) if the scrim is ground finely
enough. There are many check points during manufacturing and subsequent
fabrication and installation to patch the major pinholes.
• General (dirt) contractors should not be permitted to handle the instal-
lation of a liner. Where this has been permitted, very inadequate jobs
have often resulted, including wholesale substitution of materials.
Ba c kg round
Pantasote manufactures several types of flexible membrane liners (FML)
for lininci land disposal facilities and surface impoundments. Their princi-
pal products are PVC, reinforced Hypalon, CPE, and CPR, which are the same
materials constituting approximately 80 to 90 percent of the synthetic liner
market. These products are sold directly to a fabricator or to the general
contractor for a facility. The purpose of the interview was to determine
Pantasot&s perspectives on the problems responsible for inadequate installa-
tion of a liner system.
Perspectives on the Manufacturer’s Role in the Land Disposal Project
• Successful installation of an FIlL requires proper handling of the mate-
rial by all parties. Some of these responsibilities are established
by warranties. The following are typical
- A weathering warranty is issued by the manufacturer generally for a
period of 20 years on a pro rata basis. It addresses the resistance
of the exposed material, such as on berms, to ambient conditions.
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Interview No. A-13
Pantasote, Inc.
Page 2
- A construction warranty is issued by the fabricator and/or installer.
It is for workmanship, usually for a period of 3 years.
- A soil burial warranty has been more recently included to guarantee
that the material will not degrade while buried. This is especially
important for PVC liners because the plasticizer is biodegradable.
Depending on the job, the manufacturer’s warranties are issued to either
the fabricator/installer or to the job site directly.
• The fabricator’s and installation contractor’s liability are often
limited by even more than the typical workmanship warranty. Failure of
land disposal sites and the cause-effect connections are so poorly un-
derstood that assionment of liability can become an arbitrary exercise.
Fabricators and installation contractors are usually small businesses
having a small net worth. Manufacturers, however, typically have the
largest financial resources by which to make restitution, and they are
therefore largely blamed in any cases of failure. The once prevailing
philosophy that the manufacturer is no longer responsible for his pro-
duct once it is delivered to another party no longer applies.
• To avoid later problems, manufacturers such as Pantasote work closely
with fabricators, installation contractors, and end users, but in
reality the manufacturer has only limited control of his product once
the fabricator and/or installer takes delivery. Installers are, there-
fore, largely relied upon on the basis of their past performance. If
a relatively new installer is involved, the manufacturer may have a
representative on-site at all times. Also, Pantasote always has the
opportunity to coment on the fabricator’s or installer’s specifications.
The ultimate form of control is not selling the product, and while this
is always an option, it is rarely exercised due to the competing in-
terest of maximizing company profits. (It is fully legal to withhold
a product from a customer, so long as the same price is charged to all
who are permitted to purchase it,)
• Another form of control available to a manufacturer is to develop close
ties with reputable installation contractors, including exchanging
information on business leads.
• Before bidding on a job, issuing a warranty for a product, or deliver-
ing it for sale, complete information is needed on the material ‘s end
use. In some instances, a potential customer may choose to divulge
process information only to the company awarded the job. Then a bid
is made on the condition that all needed information will be supplied
before delivery of the material.
• As support to customers, Pantasote has one full man doing immersion
studies. For landfill applications, the leachate characteristics for
compatibility study are based on the reasonably well established values
4-114
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Interview No. A-l3
Pantasote, Inc.
Page 3
in the literature. For impoundments, the waste characteristics are
supplied directly by the customer. This information is usually avail-
able since EPA normally forces industries to characterize their waste
streams. If not available, Pantasote may work with the customer to
develop the needed information from consideration of the contributing
industrial processes.
• Industrial waste streams intended for impoundment are often character-
ized inadequately by an inventory of ions. This provides no indication
of the predominant form of the various chemical species.
• Most of Pantasote s laboratory compatibility testing is done at room
temperature and 158°F. The factor of time is accelerated so that tests
can be completed in a reasonable period, but this may well worsen the
already sensitive correlation with field conditions. As a consequence,
some liner materials that are actually suitable for the application may
be eliminated from further consideration.
Perspectives on Pinholes in Synthetic Liner Sheets
• Recycling scrap during the manufacture of a reinforced liner can cause
pinholes. These often develop by small pieces of scrirn penetrating the
surface of the material. Then, if the liquid being contained is corro-
sive enough, the protruding scrim will dissolve, creating a small hole
in its place. The practice of recycling scrap should probably be of
concern only for hazardous waste applications. Only then might the
public health be at risk. Also, if the recycled scrim is ground fine
enouch, no probleni may exist for any application. Only one manufactu-
rer is known to actively recycle scrap, but others are likely to be
tempted due to the significant cost savings involved. To control the
practice, a size limitation can be placed on the ground scrini that can
be passed through a calender, and NSF has banned the practice altogether
in their proposed standards.
• Other sources of pinholes are collapsed blisters during calendering
(e.g., cold flow of material) and contamination of the product, in-
cluding by dust. However, pinholes are not much of a problem. For
laminated products, the pinholes in separate plies would have to align
to provide a path for leachate to pass through. Also, currently used
manufacturing equipment nearly eliminates all but the smallest pinholes.
For example, with the extrusion method, contaminants that could form
pinholes are removed from the molten polymer mix by a #100 screen.
• “Fly-by—night’ firms utilizing poor quality control may be the principal
source of materials having pinholes.
• There are many check points to detect pinholes or even more serious
problems. A light station over the calendering equipment checks the
4—115
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Interview No. A-13
Pantasote, Inc.
Page 4
sheet as it is produced. Rolls are sampled arid likewise put over lights
to detect discontinuities. Finally, the fabricator and installing con-
tractors inspect the materials they receive.
Installation Practices Crucial to Developing an Adequate Facility
• Development of an adequate lined installation involves many factors,
but probably most important of these is the integrity of field seams
and their technique of construction.
• Field seams must be made in agreement with the manufacturer’s specifica-
tions; few changes are tolerable. Heat welds or adhesives are the most
comon method of seaming. Adhesives usually consist of the resin of the
material to be bonded dissolved in a solvent. When the solvent evapo-
rates, the seam becomes a continuous material.
• Contractors must not be permitted to substitute adhesives. In an extreme
case, wall paper paste was used. In addition to their questionable bond
strength, substituted adhesives are potentially incompatible with the
waste.
• To ensure a good bond, the surfaces of the material to be seamed must
be clean.
• A full program for testing all seams must be included for each job. It
is good practice to test a cut sample at the end or elsewhere, but this
is not sufficient in itself. Every foot of seam must also be checked
by some method such as air lancing.
• There is often little distinction between an installation and a design
problem. One such design problem may be an inadequate cover over the
liner to protect it from heavy construction equipment. A layer approxi-
mately 2 feet thick is needed but even this may not be enough to protect
the liner from dead standing turns by construction equipment. A study
addressing heavy equipment on liners was made by the Army Corps of
Engineers and presented at an EPA conference. Contact R. Landreth, EPA.
• Connections between the liner and concrete structures are another part
of a land disposal facility that may be poorly designed so that adequate
installation is effectively precluded. Here also, the distinction
between an installation problem and a design problem may be slight;
because even if the connections are well designed, the contractor may
cut corners to lower costs. Properly made connections use a steel strap
followed by caulking to ensure a seal. The thickness of the liner in
contact with the concrete structure should be doubled to better resist
the abrasion, but this is commonly omitted to reduce costs.
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Interview Mo. A-13
Pantasote, Inc.
Page 5
• The integrity and experience of the installation contractor are important
for ensuring an adequate installation. But even reputable contractors
may cut corners, and these are often selected in the worst possible
place. It would generally be better to use a lower quality liner mate-
rial (assuming it is compatible with the waste) than to compromise the
design.
• No installation contractor has a staff of laborers, only field super-
visors. All companies use local laborers, sometimes of the lowest quali-
ty, such as prisoners. The foreman’s ability to motivate and instruct
his crews can, therefore, be of key importance to ensuring an adequate
installation job. The owner and other interested parties should, there-
fore, have inspectors on the job at all times.
• Dirt contractors sometimes try to double as installation contractors
claiming suitable experience in this area. The result has on occasion
been blatant substitution of materials and other disregard for proper
procedures. An installation contractor should therefore always be used.
• Large installation contractors are generally preferred to the small
firms. The availability of liner installation jobs fluctuates through
wide cycles which large companies are better able to handle. However,
there are enough small facilities being installed by small companies
that this segment of the market cannot be overlooked by a manufacturer.
Perspectives on Regulations
• EPA personnel can be as knowledgeable about liners as anyone in the
business, and are usually appreciative of the state-of-the-art. How-
ever, some local or state level input would also be helpful to ensure
that the highly site-specific elements of a facility receive adequate
consideration. A design checklist for local regulators to judge a
project by might correct deficiencies in a project before it reaches
a higher review level. Even having a city engineer approve a design
before it is considered by EPA might improve designs.
• The end user is generally responsible to demonstrate that his proposed
facility will not create an environmental or public health hazard. It
is usually sufficient to cite a parallel facility as precedent. Other-
wise, the owner must develop his own data base to secure the permits.
• A final “check off” of a constructed facility by a professional engineer
is needed. All specifications should be checked a final tine with
special attention given to change-orders to ensure that none of these
has resulted in compromised quality.
4-I 17
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Interview No. A-13
Pantasote, Inc.
Page 6
Miscellaneous
• Many sanitary landfills to date have been lined with PVC and have
suffered some problems because of the biodegradable plasticizer in the
material. Microbial attack on the surface facing the waste pile can
be largely eliminated by placing a layer of sterilized sand over the
liner. However, attack from the underside, especially if organic soils
are present, is possible. Toxics, usually arsenic, should therefore be
formulated directly into the PVC. A different additive is needed for
exposed and unexposed liners. The appropriate test is ASTM G—21.
• Mechanisms of failure are poorly understood and should be studied with
the support of EPA R&D money.
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ASSESSMENT OF TECHNOLOGY FOR CONSTRUCTING AND
INSTALLING COVER AND BOTTOM LINER SYSTEMS
FOR HAZARDOUS WASTE FACILITIES
EPA Contract Mo. 68-02-3174; Work Assignment No. 109
INTERVIEW NO. A-14
Gulf Seal, Liquid : William J. Way TRW: John F. Metzger
Containment Specialists Ralph Crumbliss
Houston, TX 713-759-0861
February 7, 1983
Summary
• Many installation problems result from poorly written job specifica-
tions. If written correctly, most bids would come in at about the
same level. Use of the phrase ‘or equal” in material or procedural
specifications in particular causes problems since it, in effect, opens
the door to many substitutions.
• Quality control is imperative to an adequate installation job. How-
ever, owners do not show the same interest in construction quality of
land disposal facilities as is generally expressed by owners of other
facilities such as industrial plants. Quality control inspectors are
often inept, getting in the way more than anything else.
• While local sources of labor are relied on for installation, some
continuity is possible by using “camp followers”. These are laborers
who are willing to move from job to job, providing their own transpor-
tation and subsistence. Prevailing wage clauses in project specifica-
tions often provide enough incentive for “camp followers” to go long
distances to a job site.
• A number of quality control checks is needed on the seaming operation,
but one in particular that can be effective is to require the crews to
make a test seani on scraps of material using the exact technique and
equipment just used on the main liner. Cut samples of the seams should
also be taken and laboratory tested.
Background
Gulf Seal is an installation contractor which handles many types of
flexible membrane liner (FML) materials. The company represents a wealth
of experience in dealing with field conditions and the various arrangements
between involved parties at an installation job. The purpose of the inter-
view was to obtain the company’s perspectives on problems associated with
installing FMLs.
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Interview No. A-14
Gulf Seal
Page 2
General Perspectives on FML Installation Problems
• The attitude of owners creates many problems. Quality is claimed to
be the factor of greatest importance, but cost nearly always controls
the major decisions. Many owners are so cost-motivated that they would
permit an obviously unqualified source to handle an installation if they
came in with a lower bid.
• If the owner lacks technical expertise, he must be certain that his
consultant is providing it. Many engineers do not have sufficient back-
ground to design an adequate facility; so, where lacking, they often
solicit input from salesmen whose arguments are persuasive but not
necessarily correct. Engineers should instead pay for technical input
they need; however, they are very reluctant to dispense part of their
fee when the information is seemingly available at no cost.
• Engineering drawings can also be deficient. Anchor trenches, for example,
are often either overdesigned or underdesigned. This results sometimes
from standard drawings and specifications being recycled from earlier pro-
jects and being included with no further consideration. The trenches,
however, must be designed specific to the site, especially from the
standpoint of climatic conditions such as wind expected at the site.
• Possibly no engineering business is as sloppy as that of FMLs and asso-
ciated facilities. Owners should force liability for the design on the
engineers. Rarely are engineering firms, however, held responsible.
• One major cause of inadequate installations is poorly written specifi-
cations. Many deficiencies could be cited. If written too oppressive,
irresponsible firms are heavily favored because they are willing to
guarantee anything, no matter how distant from reality. But most
specifications are written too loose. Possibly the single feature
causing the most trouble is the phrase “or equal” attached to material
or installation specifications. This phrase ineffectuates any meaning-
ful bid specifications and opens the door to every conceivable substitu-
tion of materials or techniques that can be rationalized by salesmen.
Often the phrase is well intentioned to refer to the quality of a
specific material, but owners usually permit a very broad interpreta-
tion to mean “equal materials”. The phrase should be eliminated, and
this does not constitute a restriction of trade.
• If a project iere properly specified, most bids would come in about the
same. The “or equal” phrase is largely responsible for the wide spread
that often occurs.
• Several examples illustrate specific shortcomings that result directly
from inadequately written design specifications:
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Interview No. A—14
Gulf Seal
Page 3
- Connections between the liner and concrete structures are often
specified as being according to the contractor’s (or manufacturer’s)
recommendations. Gulf Seal does the following: galvanized iron and
aluminum are never used in a water environment; all bolts and straps
are oversized, of stainless steel construction, and closely spaced.
However, this conservative (but appropriate) approach puts Gulf Seal
at a competitive disadvantage to companies that utilize a far in-
ferior approach.
- The liner connection requirements are typically no more than a side-
stepping of specific requirements. Another example is soil sterili-
zation. This is a primitive state—of-the-art as there is no truly
effective way to kill all weeds permanently. However, this is
not reflected in specifications. A guarantee may be required for
a period of about 20 years that no weeds grow. This greatly exceeds
the state—of-the-art, but plenty of irresponsible firms are willing
to advance such a guarantee. Furthermore, while sterilization may
be required, no minimum standard is given to indicate how it must be
accomplished. Once again, the reputable firms may be underbid by
others using inferior products and procedures.
• Despite the many opportunities for a reputable firm to be underbid by
others using inferior approaches, good firms still sometimes qualify
for jobs based on costs alone.
Installation Problems Related to Inadequate Quality Control
• Even when adequate specifications are written, they are often poorly
followed. When bidding a project, many firms will ignore quality con-
trol specifications completely, knowing that they will not be strictly
enforced. Some inspectors are willing to certify anything. It there-
fore becomes the job of the quality control program to force compliance.
• A surface impoundment constructed in the Southwest is a good example of
a facility where good specifications were written but virtually ignored.
For example, some of the field seams on the side slopes were constructed
horizontally. Also, “fish mouths” in the liner were repaired by folding
the material over and sealing rather than by cutting the section out and
patching.
• Where guarantees are involved, the financial position of the firm must
be considered. Long warranties are legitimate only if they can be
backed.
• Quality control should include inspection of the manufacturer’s and
fabricator’s operations.
• The quality control measures taken during installation are often fully
inadequate. Inspectors representing the owner can be so incompetent
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that they only get in the way: they fault good work and overlook bad.
Any other craft endeavor would be inspected by a qualified indivi-
dual. With land disposal facilities, however, a “shoe salesman” may
be hired.
• The system has become so accustomed to shoddy practices that when an
owner does provide high quality inspection personnel, many installers
will increase the price believing that additional costs will be in-
volved. Gulf Seal generally discounts their price when good inspec-
tion is available, since the presence of good knowledgeable inspectors
makes the installation job much easier for Gulf Seal. Good inspectors
are welcomed.
• Quality control applied to seaming operations is particularly important
since this is an area especially prone to failure. Seams that may be
strong in shear may be weak in peel, and peel tests should therefore be
preferred as a quality control test. A peel test should be conducted
several times daily at the leading edge of seaming operations.
• -Two methods of seam testing are suggested. Random cut samples should
be taken and laboratory tested. The resulting holes are easily patched.
The other method is to “surprise” the seaming crews and require them to
construct a seam on scrap material using the exact technique that was
just being used on the liner. For example, if the weather is cool and
the crew was not using a heat gun, no heat gun is permitted on the test
strip. If the work was being done with a shadow cast on the seam or if
dirty rags were being used, the same are to be used for the test seams.
This test method gives a fairly representative indication of how well
the seams are being constructed, and while the crew is constructing the
test seam, a peel test can also be made on the main liner seal just
completed.
• The labor used for many field operations is from local sources of gener-
ally unskilled workers. Close supervision is needed, especially on
small jobs where there is not enough time for the learning curve to
plateau. In all cases, turnover during the first few days can be high
as some workers quit and others are run off the job. Training normally
consists of practice on scrap materials. It is not difficult to differ-
entiate between those workers interested in doing a good job and those
who have no pride in their work.
• Many of the same laborers have been involved in several Gulf Seal pro-
jects in California. These “camp followers” follow the firm from job
to job at their own transportation expense. This practice has worked
well, mainly because by having some continuity in labor, complete re-
training is not needed at every job. On several occasions these laborers
have been transported to other states for critical jobs, in which case
their transportation and living expenses are paid.
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• Many projects involving federal monies have a prevailing wage clause;
that is, a wage coraparable to that paid unionized labor must be made
no matter what the source of labor is. In these cases, local labor is
still used, or preferably “camp followers” who have come from an
earlier job. There are many advantages of using local sources of
labor, including the following:
— The liner installation industry is subject to widely fluctuating
business cycles. By using local laborers, off-season periods are
easily handled since workers are automatically laid off at the com-
pletion of a job. For the case of “camp followers”, word of a new
job can be easily spread.
- Mot all laborers used to date have been hard workers. any problems
associated with unions can, therefore, be avoided, including res-
trictive job descriptions. More pay does not necessarily correlate
with harder or higher quality work.
Responsibility of Parties Other Than the Installer in Ensuring an Adequate
Facility
• The manufacturer, fabricator, and end user play important roles in
determining whether a facility performs as designed.
• The more reputable manufacturers exercise some control over the fabrica-
tion of their product and monitor its use downstream. 1any others,
however, sell roll stock with no regard for how it will be handled or
used.
• The larger fabricators generally do quality work, but “fly-by-night”
firms can be a problem.
• Once adequately constructed, the facility must be operated by the owner
in accordance with its design. No changes in inputs to the facility or
operating practices should be made without consultation with the design
engineer.
• Inexperienced manufacturers should not be permitted to bid large pro-
jects or ones having otherwise sensitive conditions. Unfortunately,
experience requirements given in project specifications can be easily
circumvented.
• To reduce costs, some manufacturers have adjusted the formulation of
their product, resulting sometimes in a material that is very similar
to the original but differing, perhaps, in a few critical characteris-
tics. One such change can be in blocking, which is the degree to which
the material sticks to itself when folded. In extreme cases, blocking
can result in failure by delamination. To minimize unauthorized changes
in materials, mill specifications similar to those required in other
industries might be effective. This program would consist mainly of a
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Gulf Seal
Page 6
guarantee that the product is identical to one produced on some earlier
run. A sample of material would be submitted to the Design Engineer,
and while its exact composition cannot be determined, it can be compared
with a similar sample submitted from the earlier reference run.
Research and Development Needs
• There is no completely effective method of soil sterilization. Even
where the best products are used, only a 90 percent effectiveness may
result. While sterilization is not always required, this is still a
suitable area for research.
• Probably more liners are destroyed by trapped gas than by any other single
mechanism. Facilities underlaid by soils having high clay contents seem
particularly susceptible. The interviewee has constructed two test ponds
to study the many factors involved in gas venting, but this subject is too
large to be handled by a single company. Research or support by EPA is
needed. The following factors should be included:
— The difference in response to gas build-up by reinforced and non—
reinforced membranes.
- The influence of conditions specific to a site, particularly climatic
conditions.
— The optimum bottom slope to permit gas transfer out of the facility.
- The role of geotextile in gas venting. To what extent is it effective
particularly when it becomes saturated by water. Also, does the use
of a geotextile permit more shallow bottom slopes.
Perspectives on Regulations
• The industry has been largely unsuccessful at setting its own standards,
so EPA will have to fill the void. The result may well be standards
that are unattainable; then industry will be forced to lobby heavily for
a more realistic stance.
• While many issues related to liners are site—specific, some can still be
addressed by EPA regulation, including the following:
— Standardization of mixes and materials so that minimum compositions are
stipulated for all products referred to by a particular trade name.
— Test requirements for each liner material.
- Al] aspects of earth covers.
— Chemical compatibility testing.
• Performance standards on completed facilities may be worth considering
for regulation, but this would require a definition of failure. Also,
this approach would apply pressure on the owner when, in fact, pressure
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Gulf Seal
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applied on the Design Engineer might be much more effective since he
has the major control of a facility. Realistic leak-rate standards for
various lining systems are badly needed.
Miscellaneous
• Double-lined facilities provide the best liner design. On critical im-
poundments, the use of clay should be considered only for the lower
lining where it can be shielded from the full hydrostatic head.
• HDPE is one of the most inert materials available. A form of it is com-
monly used in the container industry to hold pure chemicals, including
organic solvents. However, HDPE is difficult to seam. Adhesive seams
are poor, at best. Recently, welded seams have made this a viable FML.
• There are pinholes in every calendered product, although the effect of
these is probably not serious. Part of the development of liner products
has been in response to pinholes. Originally, a continuous material
about 30 nil thick was produced, but to help minimize the effect of pin-
holes, a laminated product was manufactured of two plies of 15 mil thick
material. When reinforced sheets were later fabricated, wicking was
found to provide a hydraulic connection between pinholes in opposite
sheets. Much of this was reduced by changing from a nylon scrim to the
hydrophobic polyester scrim.
• CPE and CPER liner materials often present seaming and delamination
problems. Perhaps the most useful role served by these materials is as
competition to Hypalon.
• HDPE is probably the best synthetic material for a landfill FML since
it is nearly chemically inert and can elongate up to 700% and, therefore,
conform well with subsidence.
• Earth covers will stay on synthetic liners if the side slopes are con-
structed shallow enough, but such shallow slopes seldom occur.
• Some projects have specified different materials on the side slopes and
bottom. However, many dissimilar synthetic materials cannot be seamed.
On some projects, a combination of Hypalon and PVC is specified, with a
buffer strip of CPE included between the two materials. However, this
greatly complicates seaming operations since there can be five possible
material combinations to seam.
• The following book was cited as a good reference, but in some need of
update:
- William B. Kays. Construction of Linings for Reservoirs, Tanks and
Pollution Control Facilities. Wiley, 1977.
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ASSESSMENT OF TECHNOLOGY FOR CONSTRUCTING AND
INSTALLING COVER AND BOTTOM LINER SYSTEMS
FOR HAZARDOUS WASTE FACILITIES
EPA Contract No. 68-02-3174; Work Assignment No. 109
INTERVIEW NO. A-15
Arizona Refining Company: William E. Hamlin TRW: John F. Metzger
Phoenix, AZ Elizabeth M. Wilkes
William E. Ham
800-528-5305
February 8, 1983
Summary
• A distinct advantage of asphaltic rubber over most other liner materials
is that it can be formulated to have the exact characteristics needed
by a specific job site. As a result, installation is preceded by an
exhaustive program of testing mix formulations.
• Asphaltic rubber is applied by spraying. Since compaction is not re-
quired, steep side slopes can be accommodated so long as the material
is applied in a stiff condition to prevent it from flowing before set-
ti ng.
• Quality control is an important element of installation, but it is
perhaps more easily handled than similar requirements for other liner
materials since there are no seams. Separate layers or widths bond
together to form a continuous material, completely free of seams. This
characteristic also facilitates direct testinq of the material since a
sample can be taken and the hole patched with no evidence of repair.
Background
Arizona Refining Company is a wholly-owned subsidiary of the Union Oil
Company and has been in business since 1938. Arizone Refining manufactures
and installs liners made of asphaltic rubber, a mixture of asphalt, rubber,
and extender compounds. This material has characteristics unlike other
asphaltic products. Highway paving applications since the late 1960’s and
liner applications since about 1975 have all demonstrated this material’s
unusual strength and durability. The purpose of the interview was to obtain
the company’s perspectives on installation techniques and problems asso-
ciated with asphaltic rubber in liner applications.
Characteristics of Asphaltic Rubber
• Asphaltic rubber is a combination of asphalt, rubber, and extender
compounds. The rubber is usually from ground tires and is largely res-
ponsible for the material’s tensile strength and deformation character-
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Arizona Refining Company
Page 2
istics, particularly rebound. The extenders are a by-product of lube
oil manufacturing and are used to replace aromatics that the rubber
sorbs out of the asphalt.
• Both the rubber and the extenders give asphaltic rubber unusual resis-
tance to ultra violet (UV) radiation. Any asphalt exposed on the
surface is largely degraded, but further decay is prevented by the
rubber that shields lower layers. At a facility in Arizona, the Palo
Verde Nuclear Generating Station, an asphaltic rubber liner has shown
neither degradation nor cracks in direct exposure to the very high UV
flux associated with the desert Southwest. Ozone resistance is also
good. Some checking may occur on the surface but extends no deeper.
• Wind is not a problem during either installation of the liner or during
later operation of the facility.
• Asphaltic rubber cannot be compared directly with other liner materials
because no suitable tests have been devised to evaluate its character-
istics. All current tests have been borrowed from those used on
plastics, asphalts, or rubbers, but asphaltic rubber is unlike any of
these materials. The key companies in the asphaltic rubber industry
have agreed to some generic tests, but more precise standardization is
not yet practiced.
• A major advantage of asphaltic rubber is that it can be formulated to
accommbdate the conditions at each site. The mix is designed using the
following general approach. The conditions and stresses the liner will
be exposed to are evaluated, such as the type of equipment that will
operate over the liner, the stability of the base, and the exposure to
chemicals and ambient conditions. These factors establish, approximate-
ly, the needed characteristics of the li ner, such as cold temperature
bend, softening, and elasticity; and from these, a suitable first com-
bination of asphalt, rubber, and extenders can be made. From this
starting point, trial formulations are laboratory tested to develop a
mix with the exact characteristics needed. For a surface impoundment
installed at the Palo Verde Nuclear Generating Station, 90 formulations
were tested before the final mix was selected.
• While the exact mix of materials is different for each application, most
are represented approximately by the following combination of materials:
— 18 to 22 percent ground tires (the tires must have a minimum natural
rubber content of 30 percent).
- 10 percent extender.
- 68 to 72 percent asphalt.
• Locally available sources of asphalt are always investigated initially
when testing mix formulations, but if this material does not have the
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Arizona Refining Company
Page 3
necessary characteristics, asphalts may be shipped in for use or blending
with local sources. A minimum of two rubber sources is also generally
used to take advantage of the various characteristics of this material,
particularly those of additives compounded in the tires. However, it is
also important to use as few ingredients as possible to keep field opera-
tions simple. The logistics of transporting large volumes of materials
and scheduling their timely arrival is greatly complicated by increasing
the number of different materials involved.
• Long term performance can only be speculated. There is no long track
record, but neither is there one for other liner materials. However,
plenty of evidence supports an expected long term durability. For
example, asphalt remains from certain applications in early Egyptian
civilization. The Bureau of Reclamation has some asphaltic liners for
canals and other potable water-related uses that have been buried for 50
years and are performing satisfactorily. While none of these applica-
tions simulate the corrosive environment possible in a landfill or
surface impoundment, no evidence of incompatibility nor lack of durabi-
lity has yet been found. -
Installation
• The following layers are usually constructed in an asphaltic rubber-based
liner system. If the base is irregular, it is built up with sand. In-
situ soils are compacted to 95 percent of actual, maximum compaction
(not theoretical), and no protrusions greater than 3/8 inch are per-
mitted. The asphaltic rubber can be placed directly on any stable soil
after a herbicide is added if needed for weed control. A cover layer
12 to 18 inches thick is placed over the liner to protect it from punc-
ture by truck traffic.
• The asphaltic rubber is sprayed at 400 to 425°F by a truck with an arm
extending out the side. Two passes are made to build the necessary
thickness. Adjacent widths of the material are overlapped 10 inches to
ensure a good, continuous surface.
• Side slopes as steep as 1:1 have been lined, but slopes are generally
restricted to 3:1 or less due to application problems. For steep
slopes, a method of installing the liner has been developed utilizing
a geotextile to provide additional strength to the material. The as-
phaltic rubber is applied to the geotextile and the slope by hand
spraying the material in a highly viscous condition. However, this
tends to increase the minimum application thickness, resulting in a
thicker liner than needed and consequently increasing costs. The usual
thickness on level surfaces of 150 to 200 mm must sometimes be increased
to as thick as 350 mm on the slopes.
• Asphaltic rubber does not penetrate the subgrade when applied but does
adhere to it. A tack coat of a cutback asphalt may be applied on side
slopes to increase the bond.
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Arizona Refining Company
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• Asphaltic rubber liners have no seams. When properly applied, adjacent
layers or widths form a continuous material. As additional insurance,
a spread of cutback asphalt may be applied to the interface of adjacent
I ayers.
• Inadequate design can lead to failure of any liner. No liner should
be designed nor otherwise forced to perform as a structural member.
Quality Control During Installation
• Quality control is an important factor needed to ensure adequate instal-
lation of the material. This begins with compatibility testing. Arizona
Refining tests asphaltic rubber on a long term basis with the material
exposed to a wide variety of pure chemical solutions at various
strengths. Before each project, the customer’s waste stream is like-
wise tested. If deterioration is going to occur at all, it will gener-
ally be within the first 30 days of the test.
• Quality control tests during the actual installation are carried out
in a mobile laboratory stationed at the job site.
• Sections of the liner are cut periodically, measured for thickness, and
analyzed by laboratory tests such as cold temperature test and ring—
and—ball softening test. The holes are easily patched by a specially
compounded solution that, when applied, forms a continuous material.
• Quality control measures are the responsibility of several superinten-
dents that are on-site at all times. One monitors the mixing operation
and the application temperature. The rate of application is determined
by measuring the tank volume before and after each pass with the truck.
The taps on the spray bars are also checked to prevent plugging that
would result in uneven application.
• A superintendent walks the liner daily to inspect it for irregularities.
At one site, the subgrade was not properly prepared, and there were a
number of protrusions through the liner. Repair crews cut the liner at
all protrusions, repaired the subgrade. and filled the hole with a
patching compound.
• All personnel involved in critical installation operations are staff
of Arizona Refining. Most superintendents have experience at 15 to 50
sites.
• Novices in the industry can be a problem since they nay construct an
inadequate site that generates bad publicity the reputable firms must
answer to. Overall, though, the specifications on most projects have
clauses limiting the work to adequately experienced contractors.
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Interview No. A-l5
Arizona Refining Company
Page 5
Research Needs
• Carl I4onismith of the University of California, Berkeley, Department of
Transportation, has done two studies with asphaltic rubber in highway-
related applications. There is no one in academia who is experienced
with the material in liner applications.
• Tests are needed to adequately characterize asphaltic rubber. EPA,
Cincinnati, has excellent laboratories and staff to handle such a pro-
ject, but some direction should be given by a company such as Arizona
Refining since there is so little experience with the material. This
can help avoid, for example, improper handling of the material that
could essentially invalidate any tests developed.
Perspectives on Regulations
• EPA regulations are appropriate to require the use of liners and asso-
ciated procedures needed to ensure an adequate facility.
• A comon problem with guarantees is that these are often required by
the project specifications for the liner, but not for the subgrade.
Since the subgrade has everything to do with the integrity of the liner,
it too should be tightly specified, having requirements such as 90 per-
cent compaction. However, there is a general reluctance by engineers
to increase the requirements on a construction project for fear of in-
creased cost.
Miscellaneous
• An emulsified asphaltic rubber is being researched by Arizona Refining,
but no application as a liner is foreseen.
• Asphaltic rubber has a distinct cost advantage over synthetic membrane
liners that has actually forced the price of synthetics down somewhat.
Asphaltic rubber is not in more widespread use mainly because it is a
relatively new material that, typical of such, is accepted slowly.
• Asphaltic rubber is a good cover material because it can conform some-
what with subsidence. The elongation of this material is not known
exactly, but a minimum of 300 percent has been demonstrated. Further
tests are in progress. A typical cover system would consist of a 200
mil asphaltic rubber liner, overlaid by a layer of cover material having
side slopes no steeper than 10:1.
Perspectives on Asphaltic Concrete
• Arizona Refining does not construct any liner systems of asphaltic con-
crete, although they may supply the needed materials to contractors.
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Arizona Refining Company
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Asphaltic rubber is so superior that there are few situations where the
latter should be preferred.
. The main problem with asphaltic concrete is its permeability. The mate-
rial is often laid by standard highway contractors, few or any of which
can do a hydraulic-grade job. An asphaltic concrete of low permeability
requires all voids to be filled by using a higher fraction of asphalt,
smaller aggregate, and greater compaction than used in highway or park-
ing lot jobs. This also involves an increased cost. Therefore, asphaltic
concrete should probably be limited to situations where it is used in
conjunction with another liner material.
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4.2 INTERVIEW REPORTS WITH OWNERS/OPERATORS OF HAZARDOUS WASTE MANAGEMENT
FACILITIES
B-i. CECOS International, Inc.
B-2. Gulf Coast Waste Disposal Authority
B-3. Browning-Ferris Industries
B-4. Waste Management, Inc.
B-5. Lanchester Corporation
B-6. Monsanto Polymer Product Co.
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ASSESSMENT OF TECHNOLOGY FOR CONSTRUCTING AND
INSTALLING COVER AND BOTTOM LINER SYSTEMS
FOR HAZARDOUS WASTE FACILITIES
EPA Contract No. 68—02-3174; Work Assignment No. 109
INTERVIEW NO. B- ]
CECOS International, Inc.: Frank Nero TRW: John Metzger
Kerimore, NY Robert Stadelmaier Sandra Quinlivan
Kenneth Mali nowski
Peter Tarnawskyj
Ernest Gedeon
Anne E. Burke
716—873—4200
14 December 1982
Summary
• A composite liner system consisting of remolded clay and a flexible mem-
brane is crucial to realize satisfactory performance of a land disposal
facility. In-situ clay should never be relied upon. It frequently has
discontinuities that are difficult to detect, but which provide potential
paths for transport of contaminants toward groundwater.
• All of CECOS ’ exhausted facilities are capped with a system of materials
that includes a membrane that is welded to the bottom liner to isolate
the contents of the facility from the environment. Leachate results only
from water accumulated by the facility during its operating (uncapped)
phase. The volume of leachate generated decreases yearly. At about five
years following closure, only a low, background level of leachate flow
usually remains.
• Certain regulations are a concern. Some of the problems may result from
the regulations being directed primarily toward facilities that are quite
unlike those that CECOS operates.
• By combining careful design with strict operating practices, CECOS handles
with minimal problems a wide variety of industrial wastes in the Buffalo
disposal facility. Each waste is handled separately, with many receiving
some processing prior to emplacement in the landfill. Liquid wastes are
transferred to a solid form by a liquid treatment facility, and semi-
liquids are sorbed by a suitable sorbent. When finally placed in the
facility, careful consideration is given to the waste’s compatibility with
previously placed materials.
Background and Objectives
CECOS International owns and operates a secure landfill near Niagara Falls,
NY, for the disposal of industrial and municipal wastes generated in the Erie-
Niagara County area. The firm considers itself a leader in the use of innova-
tive waste treatment, recovery, and detoxification procedures prior to waste
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Interview No. B-i
CECOS International, Inc.
Page 2
emplacement in the landfill. The objectives of the interview were to obtain
information on: (a) the design, construction, operation, and performance of
the secured landfill and its HOPE liner; (b) CECOS’ perspectives on liner
regulations and R&D needs; and (c) additional references and data sources.
The perspectives and data presented herein are largely based on CECOS’ ex-
perience with the Niagara Falls facility, but also reflect CECOS’ broader
experience that includes operation of a secure landfill in Ohio, facilities
for industrial pretreatment/processing of liquid wastes, and special environ-
mental services such as emergency response. CECOS presented their practices
by an introductory movie and slides, supplemented by a lengthy round-table
discussion and presentations by the various participants present. The meeting
concluded with a tour of the landfill.
Summary of CECOS Operating Procedures
Successful handling of waste material in a secure landfill is determined
equally by the facility’s design and by operating practices. Even the best of
designed, secured landfills can be subverted by improper operations. There-
fore, operating practices are fully relevant to any consideration of liner
performance, and certain of these followed at CECOS’ Buffalo facility are
summarized below:
• The principal hazardous wastes accepted originate from various chemical
electro-metallurgical, and metal fabricating industries within an approxi-
mately 250-mile radius of the facility. CECOS also has a program for
treatment and disposal of non-incinerable PCBs and PCB-contaminated wastes.
• CECOS exercises control over all steps leading to disposal of a material.
This includes regulation of transporters, for example, by reviewing
driving records and providing instructional programs.
• Individual wastes are carefully placed, never dumped, into individual
cells in the secured facility. Five subcells are designated to handle
the following waste types:
- General waste material;
- Pseudometals (soluble at both high and low pH);
- Heavy metals;
- Flammables (e.g., entrained solvents that may have a low flash point);
- Toxics (e.g., PCBs).
• All wastes handled are catalogued into a computer library that records
waste characteristics, the waste’s exact location in the landfill, and
appropriate supporting documentation. Physicochemical characteristics
of each waste are supplied by the customer and verified by CECOS labora-
ties.
• All previous and future additions surrounding a newly placed waste are
considered to ensure that they are chemically compatible or that, if
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Interview No. 8-1
CECOS International , Inc.
Page 3
reactions do occur, they are in the direction of increased stabilization.
The objective is to immobilize all waste material to minimize the genera-
tion of leachate, and a number of other measures can be taken to ensure
this. These additional steps include separation of waste within the in-
dividual cells and case-by-case selection of cover material for each
waste addition.
• All liquid materials are immobilized or otherwise handled prior to place-
ment in the facility. “Lab packs” also receive special handling, but
not the individual vials. Semi—liquids are immobilized by addition of
sorbents, frequently an exoanded silicate naterial. Developnent of new
sorben is is a part of CECOS’ on-c’oiny R&D orogram.
• Aqueous wastes are treated by CECOS on-site to transfer the contaminating
constituents to a solid form that is suitable for landfilling. Following
treatment, the aqueous stream is discharged to a municipal wastewater
treatment plant (POTW). The level of treatment is determined by negotia-
tions with the responsible authority of the POTW.
• The liquid treatment plant is a batch operation. Each waste handled can
be input to the plant at a different point in the sequence of unit opera-
tions, according to that waste’s characteristics and treatment require-
ments. Leachate from the land disposal facility is also treated in the
liquid treatment plant, but this results in part of the plant’s capacity
being utilized in an essentially non-productive function. Less of the
total capacity is thereby available to handle liquid wastes from customers
for which the service can be assessed. This is strong motivation to
operate the landfill in such a manner to minimize leachate generation
(i.e., by careful waste emplacement to minimize void spaces, by use of
good intermediate cover practices, etc.).
• There is a leachate collection system consisting of two concrete stand-
pipes in each of the subcells, which are hydraulically connected to
4-inch perforated vitrified drainage clay pipe overlaid with No. 3 stone.
The system operates automatically in “Unit 4”. By the end of June 1983,
there will be similarly operating systems in units 1, 2, and 3. While
leachate does not freeze within the facility itself, freezing is a
problem in transfer pipes. All pipes are heat traced, but even a single,
localized malfunction can create a problem.
• There is no system designed to detect leakage of leachate at the CECOS
facility, although the groundwater is monitored extensively. The follow-
ing zones are monitored:
— Perched water table - This is due primarily to previous site owners
having deposited non-hazardous industrial waste on the site. This
material sits on top of the naturally occurring clay soils found at
the site. The “perched water table” results at this interface due to
the lower permeability of the clay soils.
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- Top of the bedrock - This zone is most heavily monitored since it is
usually first affected by any problems.
- A zone just into the bedrock.
• There is no provision to withdraw samples of the liner from within the
fill to make periodic inspection.
Construction, Liner Installation, and QA/QC
• The base layer of the Buffalo facility consists of a constructed 10-foot
layer of clay compacted to 95 percent Proctor and permeability between
io-7 and 10-8 cm/sec. This layer is topped by an HDPE liner and covered
by a 2-foot thickness of clay. External sideslopes are 3:1; slopes in-
ternal to the facility are 1:1. HDPE can support such severe internal
sideslopes; few other liner materials can do so. However, clay and other
soils do not adhere to HDPE, and the cover over the liner must therefore
be fully self-supporting on the sideslopes.
• Considerable construction skill is required to compact 1:1 sideslopes.
Only contractors having proper skills can be considered. However, to date,
all work on CECOS’ facilities has been done by a construction company that
is a subsidiary of CECOS.
• Extensive quality control and other measures are taken during construction.
No heavy equipment is permitted over the liner. The amount of seaming
done in the field is kept to a minimum.
• Seaming was done by a Lyster Seaminq Ilachine, a device that essentially
heats the material and presses it together. The seams are tested by
several methods, including visual observation, and use of screw driver
and ultrasonic tests. The screw driver test involves using such an in-
strument to attempt to wedge the weld apart. The field installer/seamer
conducts all tests, but they are certified by others, including state
people that are otherwise present to witness operations.
• Additional QC functions are summarized in “Appendix A and B” supplied by
CECOS. Wehran Engineering was responsible for the QA/QC at the CECOS
site.
• The following considerations are most crucial to ensuring that a satisfac-
tory facility is constructed:
- Placement of the clay - In-situ geology cannot be relied on.
- Quality control during all construction operations.
- Restrictions on certain construction activities during periods of cold
weather (seaming of the liner, for example).
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Liner Material Selection
• CECOS works closely with the liner manufacturer, especially during selec-
tion of the polymeric resin.
• No compatibility testing has been done by CECOS since this is considered
the responsibility of the manufacturer.
• CECOS feels that the characteristics of the liner must be carefully con-
sidered. Generally, the more dense the material, the less permeable it
is, but also the less elastic (and therefore subject to rupture) it is.
A suitable liner, therefore, represents a compromise between these two
factors.
• HOPE is considered by CECOS to have characteristics of superior resisti-
vity and good tensile strength.
Closure of CECOS’ Facilities
• The objective of closure is to fully isolate the contents of the landfill
from the environment. The principal concerns are to prevent or minimize
infiltration of water into the facility and to prevent lateral migration
of leachate.
• All CECOS’ facilities are capped by a system of materials that includes
the following: a clay cap adjacent to the uppermost layer of waste
material, a 20-nih HDPE membrane, soils to support vegetation, and top-
soil. The membrane is seamed to the bottom liner so that the contents of
the facility are encapsulated.
• Each facility is mounded to facilitate run-off of precipitation and to
better control subsidence*. None of the closed facilities have experienced
subsidence. (The longest period of closure is about four years).
• After closure, each facility is fully managed, including control of leach—
ate and provision of contingencies (such as fire protection). A full
maintenance program is operated and includes one full man to operate the
leachate collection system (for those facilities not havin ’ autoriatic
leachate collection).
• Nearly all leachate generated is believed to be from water entering the
facility before closure of both individual cells and of the entire facili-
ty, and from water held by the waste that was not fully removed prior to
addition. Very little leachate is generated five years following closure.
*HOw mounding can control subsidence was not elaborated on.
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Interview No. 8-1
CECOS International, Inc.
Page 6
Perspectives on Regulations and Regulatory Reform Needs
• In concurrence with current Part 264 regulations, a synthetic liner is
considered essential for all land disposal facilities. However, the
combination of clay and synthetic liners provides the best assurance of
performance. An important role played by clay is to attenuate any leach—
ate that might escape the liner. All such clay that is directly a part
of the liner system should be fully reniolded. No in-situ geological
formations can be relied upon due to the possible presence of secondary
pernieabilities (cracks, sand lenses, etc.) that readily escape detection.
• CECOS’ concerns about permitting standards (interim final) for land dis-
posal facilities are summarized in a letter (dated 18 November 1982) to
US EPA (Docket Clerk, Office of Solid Waste). Following are some of the
concerns.
- There are several concerns with a requirement limiting the depth of
leachate over the liner to a maximum of 30 cm. This requirement is
especially difficult to comply with during the operating period of a
facility preceeding closure. No direction is given concerning what
constitutes the bottom of the liner. The floor of the facility is
sloped to aid in collecting leachate, resulting in large differences
in elevation where large areas are considered. The depth of leachate
above the bottom liner will, therefore, vary considerably with the
position considered in the facility. Additionally, when the facility
is open during its service life, some siltation occurs in the leachate
collection reservoirs. The depth of this material has not been con-
sidered in specifying the 30 cm limit.
- Certain situations are possible under the framework of the interim
final standards whereby neither a liner nor a leachate collection
system is required. CECOS’ position is that no conditions are suitable
to eliminate the need for a liner. For nearly every case, a composite
system combining a synthetic membrane with reniolded clay is the only
appropriate approach. A similar concern is the possibility of liquids
being handled by a facility with two membrane liners. Such a system
would be exempt from leak detection; however, CECOS does not consider
this to be acceptable practice.
- There are requirements for run-on and run-off control systems. This
requirement has, perhaps, been developed by assuming typical conditions
at a “standard” facility. Such a requirement, however, does not apply
to the CECOS facilities as each is constructed well above the elevation
of the 25-year storm.
- There is a requirement that the leachate collection and detection
system be operated until leachate is no longer detected. Any possibi-
lity of this requirement interfering with transfer of a site to the
authority of the Post-Closure Liability Fund (per Section l07(k)(3) of
the Comprehensive Environmental Response, Compensation and Liability
Act of 1980) should be eliminated. In particular, better definition
of the term “no leachate detected” is needed. Most leachate is
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Page 7
generated within a five year term following closure of a site. However,
a very low level of leachate continues to be generated over the longer
term. This level should be specified as “no leachate detected”.
— There is concern that lab-packs will require individual handling of
the containers to fulfill requirements that no liquids be introduced
into the facility. CECOS has successfully immobilized the contents of
lab—packs without handling individual containers.
Miscellaneous Considerations
• CECOS conducts extensive R&D oriented toward detoxification and recovery
of materials. The proper emphasis in disposal of solid wastes is in the
area of improving the characteristics of the materials that must be
landfilled rather than in addressing the landfill itself, such as liner
compatibility.
• The volume of industrial wastes received from individual customers has
generally decreased due to volume reduction, modification of industrial
processes, substitution of materials, detoxification, and resource reco-
very.
• Vestalin liners produced by Schiegel Mfr. (West Germany) are excellent
liners and are preferred at many European sites.
Reference Documents Provided
• “Executive Summary: Ten Year Technology Plan”, CECOS International.
• “Appendix A: Quality Control Program, SCMF No. 4 - Liner Installation”,
October 6, 1981.
• “Appendix B:. Oxford Liners, Inc., Ultrasonic Test Instrumentation,
Theory of Operation”.
• Letter from E.J. Norman, Corporate Counsel, to U.S. EPA/OSW dated Novem-
ber 18, 1982, regarding Docket 3004, Permitting Standards for Land Dis-
posal Facilities.
• Eight miscellaneous brochures and pamphlets describing CECOS’ operations.
Additional Suggested Contacts
• Mr. Franc Grabar; NY State Department of Environmental Conservation,
Buffalo, NY; for computerized waste input and leachate monitoring data,
and additional background/performance data.
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ASSESSMENT OF TECHNOLOGY FOR CONSTRUCTING AND
INSTALLING COVER AND BOTTOM LINER SYSTEMS
FOR HAZARDOUS WASTE FACILITIES
EPA Contract No. 68-02-3174; Work Assignment No. 109
INTERVIEW NO. 6—2
Gulf Coast Waste Disposal: Robert Dyer TRW: Michael D. Powers
Authority; LaMarque, TX 713-935-4783 Michael T. Haro
15 December 1982
Summary
• GCWDA is a commercial facility that accepts wastes from two refineries and
two chemical plants in the Texas City area.
• The facility uses recompacted clay liners because at the time of permit
application:
— The state required clay;
— The facility manager does not trust synthetics;
— Suitable low permeability clay is available on site.
• The operator of a hazardous waste facility should choose the liner that
is most appropriate for his site.
• Compatibility between liner and waste is a theoretical concept with little
practical application. Rather than conduct extensive testing, operators
of a facility should rely on the experience gained from disposing the same
or similar wastes.
Background
Gulf Coast Waste Disposal Authority (GCWDA) is a commercial facility
accepting wastes from only four participants in the Texas City area: Marathon
Oil, Texas City Refining, Monsanto, and Union Carbide. GCWDA’s Texas City
facility began construction in July 1979, was put into operation in March of
1980, and had new disposal trenches added in 1981 and 1982. They currently
operate five active landfill trenches for different types of wastes, and one
land treatment unit; none of these units has been closed.
The following are perspectives of GCWDA on: (a) various aspects of liner
design and installation; (b) operation; (c) quality assurance/quality control
requirements; and (d) adequacy of regulations and regulatory reform needs.
The statements and assertions, which are largely qualitative, reflect the ex-
perience of GCWDA; quantitative technical and engineering data to support the
statements and assertions were not provided.
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Interview No. B—2
Gulf Coast Waste Disposal Authority
Page 2
Design and Installation of Liners
• Clay liners only are used at the site. The land treatment unit (land—
farm) has an in-place natural clay liner; liners for the landfills con-
sist of recompacted clay derived from excavation of the trenches.
• GCWDA uses clay liners for two main reasons:
- Texas Department of Water Resources refuses to allow any material
other than clay for liners; GCWDA does not particularly like syrithe—
tics either. State regulations require clay with a permeability
less than 10 cm sec .
- GCWDA has ample clay available on site; water-well drilling logs in-
dicate that the facility is underlain by at least 260 feet of low-
permeability soil assigned to the Beaumont Clay and Lake Charles
Clay formations.
• State regulations contain guidelines for design parameters such as
thickness of liner and side slopes. In addition, permits from TDWR con-
tain specific construction requirements.
• Geotechnical studies of the site were conducted by Southwestern Labs and
Law Engineering; GCWDA prefers to have two geotechnical consultants be-
cause “soils are less than an exact science”.
• Compatibility testing of the disposed wastes with the clay liners is not
conducted; instead, GCWDA assumes compatibility, relying on the many
years of experience Union Carbide and Monsanto have had in disposing
similar wastes into the same clay; the state has allowed this.
• Liners are constructed by excavating trenches, scarifying the bottom,
removal of side walls; this technique is necessary to seal silty and then
recompacting lenses. Excavation and liner compaction work are done by a
dirt-work contractor. There have been no real problems during construc-
tion, although some soil slumps occurred later that had to be repaired.
• Construction QA/QC is done by soils engineers on-site during dirt work;
liner is certified as meeting specifications by a Registered Engineer.
Tests include:
- Visual check for proper construction;
- Compaction by means of nuclear density measurements;
— Permeability using falling head permeameters.
Leachate Collection System
• Leachate is defined at GCWDA as “that which we collect from our leachate
collection system”. They haven’t generated too much leachate except
after periods of heavy rainfall.
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Interview No. B-2
Gulf Coast Waste Disposal Authority
Page 3
• Each landfill trench has its own leachate collection system. This system
consists of coarse sand and/or gravel with slotted pipe placed in the
bottom of the trench above the liner. This pipe leads to a manhole from
which collected leachates can be pumped off at weekly intervals or as
needed.
• TDWR allows three methods for disposing of leachate:
- Incorporate it into soil;
- Send it to another site;
- Other method as authorized by TDWR Executive Director.
GCWDA uses the first method listed.
• Analytical results from recently collected leachate are being forwarded
to TRW.
Operation
• The facility currently operates one landfarm unit and five landfill
trenches, none of which is closed. The landfarm handles refinery wastes
such as slop oil, tank bottoms, and API separator sludges, with the land-
fill handling refinery process wastes, cooling tower sludge (the sludge
does not contain Cr+ 6 ), insulation and metal catalysts. Guidelines in
the state regulations require segregation of certain reactive wastes into
separate landfill cells; acrylonitrile sludges, neutralized ‘acid” wastes
(pH is around 12-1/2), and metal catalysts are kept separate from a
general waste trench.
• No leak tests as such are conducted in the liners; instead, GCWDA relies
on their leachate collection system and groundwater monitoring. The
groundwater monitoring system consists of 12 wells; of these wells, one
is located up slope and three down slope from the disposal area; GCWDA
considers these their “EPA wells”. Three more wells are located in the
actual disposal area, and the rest are scattered around the facility.
There is a brackish aquifer occupying an old buried stream channel
approximately 15-30 feet below the surface in the northerly portion of
the site; no disposal is allowed in this area.
General Comments and Perspectives
• The facility manager would not choose a synthetic liner unless forced to
do so by EPA. The use of plastic liners is governed by “Murphy’s Law”;
there are too many things that can go wrong with them. Also, there is
no way to adequately test these liners. Although not a happy prospect,
the current EPA synthetic liner requirements are expected to stand.
• It is not possible to install liners within the current regulations so
that they will not leak; as the regulations currently stand, the time
frame specified is unrealistic.
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Interview No. B-2
Gulf Coast Waste Disposal Authority
Page 4
• The operator of a hazardous waste disposal facility should use the liner
that is most appropriate for the site. The specific characteristics of
a site can overcome inherent problems of a liner system. For example,
clay can dry out and become badly cracked, but because GCWDA is located
right on the Gulf Coast, the clay is almost constantly saturated.
Shallow cracks can form, but will not affect performance of the liner.
• Compaction of clay liners is very important. Because soil is a natural
material , it contains inhomogeneities such as sand lenses that can have
much higher permeability than the surrounding clay. Over-excavation and
recompaction result in a much more homogeneous liner material.
• Compatibility between waste and liner is a nice theoretical concept
which is primarily of academic interest but of little practical utility.
Waste has no specifications. Material that meets specifications would
be considered a by-product and either reused or sold. Wastes contain
varying concentrations of contaminants that cannot be removed economical-
ly; these contaminants, in an otherwise benign waste stream, can affect
the liner. Based on K. W. Brown’s work, aromatics and other organics can
become soluble in water; these chemicals can deteriorate synthetic liners
and can make clays more permeable. For these reasons, the facility
does not conduct compatibility testing, but prefers to rely on the ex-
perience of Monsanto and Union Carbide with the same wastes in nearby
facilities.
• From a technical standpoint, QA/QC guidelines in the regulations covering
both facility operators and installation contractors are desirable. Such
requirements are likely to slow down operations and increase costs, but
the amount of increase is uncertain due to widely varying bid rates.
From a political standpoint, QA/QC guidelines may not mean a great deal;
if the public does not want a landfill in its neighborhood, it is unlike-
ly to accept data or be reassured by a QA program.
• The facility manager is concerned that EPA might require a double synthe-
tic liner. For this particular site, GCWDA would however prefer the
addition of a single synthetic liner to the existing clay liner.
4-143
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ASSESSMENT OF TECHNOLOGY FOR CONSTRUCTING AND
INSTALLING COVER AND BOTTOM LINER SYSTEMS
FOR HAZARDOUS WASTE FACILITIES
EPA Contract No. 68-02—3174; Work Assignment No. 109
INTERVIEW NO. B-3
Browning-Ferris Industries: Robert Johnson TRW: Michael T. Haro
Houston, TX Jerry Duggan Michael D. Powers
713—870-7913
17 December 1983
Sunirna ry
• BFI has considerable experience with the design, installation, and per-
formance of both clay and flexible membrane liner systems. Based on
experience from four BFI sites, little confidence can be placed on syn-
thetic liners and in-place clay. Five feet of recompacted clay can prove
effective if the clay is installed according to site specific design and
under a comprehensive quality assurance program, and the facility is
operated in the absence of any liquid wastes and designed so that the
cell will only be open for part of the year to minimize erosion.
• The three greatest problems/concerns with flexible membrane liner systems
are as follows:
- The technology is probably unavailable currently to properly install
such liners.
- It is not possible to completely control trace contaminants in wastes
received at hazardous ‘aste facilities.
- Heavy equipment and miscellaneous tools can puncture all types of
flexible membrane liners.
• A 5-foot compacted clay liner is more resistant to mechanical and chemi-
cal damage than any flexible membrane liner.
• QA/QC procedures and third party audit should be added to the regulations.
EPA should not develop only one set of QA specifications because liners
are custom-designed by location. The third party auditor should be an
engineering firm that assumes responsibility for their certification of
each secure cell.
Background
Browning-Ferris Industries (BFI) is the operator of a number of hazardous
waste treatment, storage, and disposal facilities throughout the country.
Because of poor contractor performance in the past, the company now designs
and constructs their own hazardous waste disposal facilities. BFI is a pro-
ponent of an approach to hazardous waste facility design, construction, and
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Interview No. B-3
Browning-Ferris Industries
Page 2
installation that incorporates the use of compacted clay liners. The liners
are installed according to site-specific design details and stringent quality
control/quality assurance measures, as demonstrated in their Livingston,
Louisiana, secure landfill site. This approach is based on years of company
experience with both clay and flexible membrane liner systems.
The following are perspectives of the company on: (a) site-specific ex-
perience with hazardous waste facility liner systems; (b) liner and cover
design and performance considerations; (c) installation procedures; and (d)
quality assurance programs and regulatory reform needs. The statements and
assertions, which are in part qualitative, reflect the extensive experience of
the company; quantitative specifications and some permeability test results
for the construction of secure cells at the Livingston site were provided.
Site-specific Experience
• Baltimore, Maryland, site: This site consists of a sanitary landfill with
an in-place clay liner that will close in January 1983, and a treatment
system for the leachate from the landfill. The leachate is treated in
neutralization and settling lagoons. The company hired a contractor to
install a compacted clay liner in the lagoon. BFI conducted tests on the
contractor’s work and discovered that the liner had been installed im-
properly. Due to time constraints, BFI decided to install a flexible
membrane liner. A high density polyethylene (HDPE) liner, which BFI con-
sidered the best flexible membrane liner available, was installed exactly
according to the manufacturer’s specifications. After installation, the
facility received 7-1/2 inches of rain and water seeped under the liner.
When BFI began placing clay over the HDPE, they noticed “water geysers”
emanating from the liner. The geysers were caused by flaws (pinholes) in
the liner material. This convinced BFI that flexible membrane liners
will not perform adequately.
• Ohio site: Construction began in 1973 on two surface impoundments with
Hypalon liners designed to fixate pickling liquor wastes. Because there
were other less costly methods of treating these wastes in the area, the
company never operated the facility as designed. However, the impound-
ments were used to temporarily store the wastes and when the wastes were
finally removed, they discovered that the liner had leaked.
• Houston, Texas, site: The company operates two large surface impound-
ments lined with Hypalon at this location. There is evidence of physical
deterioration of the liner as well as soil movement behind the liner.
The company discovered that metal ears on the hoses of trucks used to
place waste in the ponds had been puncturing the liner. BFI replaced the
Hypalon with polyethylene liners; these liners also failed. The company
subsequently closed the facility.
• Lake Charles, Louisiana, site: BFI purchased this 40-acre site containing
pits, ponds, and lagoons that were used to store brines, refinery wastes,
and treated solidified wastes. The impoundments were lined with in-place
clay soil. These ponds had also been leaking.
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Interview No. B-3
Browning-Ferris Industries
Page 3
Liner Design and Performance
• The Louisiana State regulations require a minimum 3-foot clay liner for
hazardous waste facilities. The use of in-place clays is unacceptable
to the state. Because of these stringent regulations, BFI developed a
high performance secure cell design for the Livingston Secure Landfill
Facility*. The design consists of a 5-foot cell base layer of compacted
clay underlain by a 1-foot layer of sand followed by a 2-foot bottom
layer of compacted clay. A leachate collection system, consisting of a
sump and gravel drainage trenches with perforated PVC pipe, is installed
above the 5-foot clay base prior to placement of waste in the cell. A
leachate detection system between the clay layers is also incorporated
into the cell design. Side slopes are constructed in vertical lifts.
All lifts are 6 to 8 inches, and each lift is tested for compaction and
permeability, and certified by a consulting geotechnical engineering
firm. A secure hazardous waste cell will produce the most satisfactory
results when the system is designed in this manner.
• The Louisiana facility is designed so that the cells will only be open
for approximately six months in order to minimize erosion.
• BFI does not dispose of any liquids in its landfills. Liquids are soli-
dified first, using fly ash or kiln dust. The liquids react with the ash
or dust instead of the clay liner.
• With the use of 5 feet of compacted clay, the concern over heavy equip-
ment (or other sources of mechanical damage) does not exist as it does
with flexible membrane liners.
• When constructing secure cells with 5 feet of compacted clay, 60,000 to
160,000 cubic yards of clay are used. In contrast, flexible membrane
liners are very thin. A 5—foot thick compacted clay liner is more
chemically resistant-to a given volume of any hazardous waste compound
than flexible membrane liners.
• At the Louisiana site, groundwater will penetrate the clay liner system
throughout the operation and closure of the facility, a time period of
about 50 to 60 years. With time, an equilibrium will be reached between
the groundwater and the water inside the cell. Then the water (and
waste) inside the cell will move slowly in the direction of groundwater
flow. It may be hundreds to thousands of years before the waste front
passes through the liner.
*
Complete design details for the Livingston facility are presented in a report
entitled “Specifications for Construction of Secure Cell at BFI Livingston
Site”. Evaluation and analysis of these design specifications is not pre-
sented here, but is reserved for the final report.
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Interview No. B-3
Browning-Ferris Industries
Page 4
• Kirk Brown performed a study on the effects of concentrated organic
solvents on the permeability of clay soils. The ratio of the volume of
chemicals to that of the clay, and the fact that the chemicals are in
the liquid state, are critical to interpreting the results.
• In anticipation of the July 1982 regulations,BFI has developed a land-
fill design that will incorporate the use of a flexible membrane liner.
The company will simply use their state-of-the-art clay liner system
(i.e., the Louisiana site design) and place a flexible membrane liner on
top of the clay system.
• A major problem with using flexible membrane liners is waste—liner com-
patibility. It is difficult to completely control trace contaminants
in the types of wastes received. For example, there may be enough trace
organics in an inorganic waste to damage an otherwise inert synthetic
liner.
Liner/Cover Installation
• Liner installation is extremely important to the overall performance of
the liner system. It is questionable whether the technology is available
to properly install flexible membrane liners at this time.
• There also can be difficulties with the installation of clay liners. Due
to problems with contractors in the past, BE! now constructs and installs
their own clay liner systems.
• BFI caps their secure cells with 3 feet of clay and 1 foot of topsoil.
The waste in the cell is 75 to 80 percent compacted during the regular
operation of the cell, and BFI does not recommend the waste to be com-
pacted further before capping. BFI has had no problems with subsidence
(problems will occur if containerized liquid wastes were placed in the
cell).
• Since cell covers are only preventing water infiltration and are exposed
to limited heavy equipment trafficking, flexible membrane liners may be
suitable capping materials in conjunction with clay and top soil.
Quality Control/Quality Assurance
• Quality assurance is enhanced by having a third party auditor during
design and construction of a secure cell. The third party should be an
engineering firm that reports to the operator on the witnessing, testing,
and certification of each aspect of cell construction (e.g., subgrade
preparation, liner installation, etc.). The operator should be able to
sue the engineering firm if the liner does not perform as certified.
This measure ensures the competence of the third party.
4—147
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Interview No. 8-3
Browning—Ferris Industries
Page 5
• BFI would welcome QA requirements in the regulations since BFI already
has an established and comprehensive QA program, while many of their com-
petitors do not. Many state regulations require the applicant to document
construction specifications and EPA should not devise a single set of
specifications because liner systems must be custom-designed by location.
• Requiring a QA program in the regulations will increase costs, but should
not slow down schedules. By design, operators should account for QA in
their facility construction schedules.
References
• Browning-Ferris Industries Specifications for Construction of Secure Cell
at BFI Livingston Site. Approved by Robert Johnson and James Jones.
June 1982.
• BFI—Livingston District Permitting Study (various permeability and hy-
draulic gradient test results). Investigated by Soil Testing Engineers,
Inc., and Jones, Walker, Waechter, Poitevent, Carrere & Denegre. 1982.
• For complete details and to obtain copies of permit files on the Living-
ston, Louisiana, site, Mr. Johnson suggested that TRW contact Jim Porter
with the Department of Natural Resources, Baton Rouge, Louisiana.
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ASSESSMENT OF TECHNOLOGY FOR CONSTRUCTING AND
INSTALLING COVER AND BOTTOM LINER SYSTEMS
FOR HAZARDOUS WASTE FACILITIES
EPA Contract No. 68-02-3174; Work Assignment No. 109
INTERVIEW NO. B-4
Waste Management, Inc.: John Rohr TRW: Masood Ghassemi
Oak Brook, IL Steven Menoff John F. Metzger
Don Walgreen
312-654-8800
- January 27, 1983
Surnriia ry
• Synthetic liner material has better permeability characteristics than
clay, but clay liners are less susceptible to failure due to installa-
tion errors. A clay-FML combination system, whereby clay offers back-.
up capabilities, can probably provide the most protection.
• Identification and removal of discontinuities such as sand and silt
lenses from clay during installation is essential to developing an
adequate clay liner. The task, however, requires trained personnel
due to the difficulty in distinguishing some discontinuities from the
background clay.
• Unless proper supervision is provided by a capable foreman, the cormion
practice of using unskilled labor in installing FML liners is conducive
to poor quality of the installed liner.
• Maintaining a properly functioning cap is probably the most expensive
part of post closure care. Subsidence and erosion are two critical
factors which should be addressed in design.
• Materials other than clay and FML are generally less suitable for lining
hazardous waste facilities.
• Research and development efforts should include programs to assemble
design vs. performance data for various liners under actual use condi-
tions.
Bac kground
Waste Management, Inc., has extensive experience in collection, trans-
portation, and disposal of solid wastes. It owns and operates a number of
land disposal facilities having various liner systems including in-situ and
reformed clays, flexible membrane liner (FML) of various types, and clay—FML
combination systems.
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Interview No. B-4
Waste Management, Inc.
Page 2
The purpose of the interview was to determine the company’s perspectives
on engineering and installation aspects of FML and clay liner installation.
Relative Merits of Clay and FIlL, and Compatibility Testin g
• On the basis of the relative permeability of the liner material and the
usual liner thicknesses used in practice, an FML should theoretically be
more suitable than clay for lining hazardous waste land disposal sites.
Neither type, however, can be relied upon entirely and an approach using
an FIlL-clay combination system is probably more desirable. If only a
single liner material must be used, clay would probably be better be-
cause it is more forgiving.
• Standard laboratory compatibility tests do not adequately simulate field
conditions. The difficulties primarily relate to the short duration of
these tests and the general inability to establish, with certainty, the
composition of the leachate from a particular facility (the composition
is also subject to a wide variation).
• Waste Management, Inc., has obtained some data on leachate characteris-
tics for three of its clay-lined facilities. The data have been used in
conjunction with liner manufacturers’ information on liner material
properties to assess liner compatibility at other company sites using
FML.
• Compatibility problems can be at least partially reduced by providing
the facility with a system for the collection and removal of leachate.
Per corporate policy, all new company sites where annual precipitation
is 20” or more incorporate leachate collection (usually via sand or
gravel drains). The leachate may be recycled to landfill, discharged
to a POTW, treated on site, or solidified and returned to the facility.
Installation Problems
• Most cases of liner failures can be attributed to poor design and in-
adequate quality control during installation.
• Tests for quality control during clay liner installation include deter-
minations of moisture content, degree of compaction, and permeability.
Identification and removal of discontinuities in clay (e.g., silt and
sand lenses) are important and require trained personnel due to the
similarity in color and texture between such discontinuities (especially
silt lenses) and the background clay. The presence of silt lenses has
been identified as the cause of failure for some water reservoirs. No
such determination is possible for landfills due to the inaccessibility
of the liner for inspection.
• Unless proper supervision is provided by a capable foreman, the use of
unskilled labor for installation of FML (a common practice) can lead to
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Interview No. B-4
Waste Management, Inc.
Page 3
poor work quality. A capable foreman can provide the necessary training
and leadership to the unskilled laborers who, at least on some occasions,
have been hired directly from the local unemployment lines. Some instal-
lation jobs in Florida have used off-duty police and fire protection
personnel with considerable success.
• Proper design would not allow the use of horizontal seams on the side
slopes as gravity—related stresses can lead to failure of such seams.
• From the standpoint of reducing field seaming requirements, HDPE has an
advantage over some other FMLs in that it can be manufactured and de-
livered to the site in larger sections.
• Waste Management, Inc., is currently developing an overall QA/QC policy
applicable to all new installations. Certain elements of the policy,
which have been followed by the company in the past, include:
- Inspection of the operation of the prospective liner manufacturer
and fabricator.
- Use of reputable manufacturers and fabricators, preferably those
with which the company has worked in the past.
- Presence of a company representative at the site during installation
to ensure strict compliance with specifications (field seaming should
be under continuous surveillance; the company has, on several occa-
sions, shut down a construction site due to the contractor not
adhering to specifications).
— Inspection to ensure base compaction according to specifications and
complete removal of all projections.
Perspectives on Caps
• FML can be an excellent material for caps. Generally, placement of a
1-foot clay on top of the membrane and keeping flatter than usual side
slopes will prevent the clay cover from sliding off.
• Facilities having a clay bottom liner usually also use clay for the cap.
Secured facilities are usually capped with a 2 to 4 foot thick clay layer
with 6 to 7 percent too slopes to control erosion and minimize subsi-
dence. Erosion is probably the most destructive force affecting the
longevity of clay caps.
• Bentonite caps may be susceptible to desiccation cracking, even when
there is a soil with vegetation cover.
• Maintaining a properly functioning cap is probably the most expensive
part of post-closure care. While subsidence cannot be totally elimi-
nated, it can be minimized significantly by use of proper operating
practices during waste emplacement.
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Waste Management, Inc.
Page 4
• Landfill gas moving through the cap can kill the vegetation on the
cover. The problem can be eliminated by proper design which would
allow venting.
• Cap design can influence the movement of leachate across the bottom
liner. In one facility in Delaware, capping resulted in the leachate
plume retreating.
Perspectives on Liners Other Than Clay and FML
• In general, liners other than clay and FML would probably be less
suitable for lining hazardous waste sites. For example, asphaltic
liners cannot be fully relied upon where there is a possibility of
ground movement. (Waste Management has acquired a site which uses an
asphaltic liner.)
• If properly applied, soil cements can provide an adequate liner.
Quality control requirements, however, are even more important than
for FML or clay.
Research and Development Needs
• A data base assembled on design vs. actual performance of liners and
other “real world” studies involving full installations would be most
helpful and will advance the state-of-the-art.
• Suitable methods should be developed to assess liner performance under
actual use conditions. One study proposed previously, which involved
taking core samples from liners, was received less than enthusiastically
by owners/operators due to the potential for permanent damage to the
liners and hence consequent liability.
Regulatory Perspectives and Miscellaneous Considerations
• Licensing of liner installers below the foreman level is probably un-
necessary and impractical.
• A checklist of key factors leading to a successful installation can be
helpful to regulatory agencies charged with permitting land disposal
sites. The checklist should be general , as specific requirements would
be site-specific.
• The State of Texas and several others requires certification of land
disposal facilities construction by a professional engineer.
• There is a general trend for municipalities to turn over the responsi-
bility for operation of land disposal sites to the private sector. In
this connection, Waste Management, Inc., has contracts with several
municipalities.
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Interview No. B-4
Waste Management, Inc.
Page 5
Documents Received from Waste Management, Inc .
The following documents have been provided to TRW by Waste Management,
Inc.:
• Two documents on leachate characterization test results for two hazar-
dous waste sites.
• “Technical Specification No. 5-2, Construction of New Solid Waste Dis-
posal Cell: Bottom Liner Phase II — Geomembrane Liner and Leachate
Collection System” (this document provides FML installation specifica-
tions used at the Waste Management’s Furley, Kansas fadlity).
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ASSESSMENT OF TECHNOLOGY FOR CONSTRUCTING AND
INSTALLING COVER AND BOTTOM LINER SYSTEMS
FOR HAZARDOUS WASTE FACILITIES
EPA Contract No. 68-02-3174; Work Assignment No. 109
INTERVIEW NO. B-5
Lanchester Corporation: Morris W. Holman, Jr. TRW: John F. Metzger
Honeybrook, PA 717-354-4351
February 1, 1983
Sumnia ry
• An asphaltic concrete liner can be installed by standard asphalt con-
tractors since the job is no different than a highway paving project.
These contractors have considerable experience handling the material.
No equivalent level of experience exists for other liner materials.
• The asphaltic concrete liner at the Lanchester facility is sufficiently
impermeable to protect the environment. However, permeability is not a
big issue because of the unusually steep side slopes within the facili-
ty and the provision for collection and removal of the leachate.
• Caps constructed of carefully selected native soils perform well al-
though some maintenance is required Subsidence that can potentially
destroy the cap cannot be eliminated completely, but can be minimized
by careful operating practices. This must include prohibiting liquids
in the waste pile since a void forms when the liquid leaks out of its
containing vessel
• host EPA requirements are legitimate but facilities should not be re-
quired to supply exhaustive characterizations of leachate and other
waste streams. These requirements in effect force the facilities to
support EPA research resulting in higher charge to customers that
ultimately make the facility a less attractive disposal option.
Background
At its Honeybrook location, the Lanchester Corporation owns and operates
a sanitary landfill, a hazardous waste facility, a wastewater treatment plant
for the leachate from the sanitary landfill, and a hazardous waste stabiliza-
tion facility. The sanitary and hazardous waste facilities are each lined
with asphaltic concrete. The purpose of the interview was to obtain perspec-
tives on installation and general performance of an asphaltic concrete liner.
Design of the Lanchester Land Disposal Facility
• The niajor operation of the Lanchester Corporation is the sanitary land-
fill. Soil beneath it was excavated to a very stable “plate rock”
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Lanchester Corporation
Page 2
formation, and a one-foot layer of natural soils was placed and com-
pacted. French underdrains were included to provide dewatering as
necessary and leak detection. A liner of 4-inch thick asphaltic con-
crete was constructed on the compacted soil and topped with an 18-inch
soil layer having leachate collection pipes. Flows from both the under-
drains and the leachate collection network can be monitored.
• The facility is situated in a valley having steep slopes (generally not
less than 5 percent). The permeability of the liner is therefore less
of a concern than in many land disposal facilities since the residence
time of leachate over most of its extent is very short.
• When the facility was designed and constructed around 1974, the tech-
nology for synthetic membranes was not well developed. This and the
relatively low cost of asphaltic concrete were principal reasons for
its selection as the liner material.
• No compatibility testing was done because information published in the
open literature established that asphaltic concrete is compatible with
leachate from sanitary landfills, having an overall resistance not much
different than PVC. Only solvents, oils, and grease readily pass
through the liner and, therefore, cannot be handled in the facility.
The sane, however, is largely true of synthetic membrane liners.
Perspectives on Installation of an Asphaltic Liner
• All operations associated with installing an asphaltic liner are iden-
tical to those used in highway construction. Standard asphalt contrac-
tors can therefore be used, and their considerable expertise developed
from roadway jobs can be applied to real advantage in constructing the
liner. No other liner material has a comparable advantage.
• The asphaltic liner derives its support from the subbase; under no con-
ditions should it be relied on for strength. At the Lanchester facili-
ty, a solid base constructed of native soils is possible largely because
of the area’s very stable geology. In locations were ground movements
are likely, however, asphaltic concrete is not a suitable liner material.
• The asphaltic mix used in the Lanchester facility was a standard State
of Pennsylvania mix of materials with a 1/2-inch aggregate base. The
characteristics of the nix were not considered in detail, but generally,
if the aggregate is too small, the concrete will not have enough
strength; if the aggregate is too large, the concrete will be too per-
meable for a liner application.
• The temperature of the asphaltic mix during application must be main-
tained within narrow limits, although this is easily done by construc-
tion crews experienced in highway work. Side slopes as steep as 3:1
can be handled, but on the more severe slopes, compaction by rolling
equipment becomes difficult.
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Lanchester Corporation
Page 3
• After placement, the asphaltic concrete is sealed with a spray applicant.
If rain or moisture accumulates on the surface between these steps, the
sealant does not penetrate the asphalt as well as it otherwise would.
• The interface between adjacent widths of the asphaltic concrete bonds
well to form a tight seal.
• Poor construction quality is a potential problem comon to all engineer-
ed projects. Other areas of potential compromise include switching
materials or cheating on the concrete mix. None of these problems,
however, are worse than at other construction sites.
• The Lanchester Corporation’s landfill is somewhat unique among medium
sized facilities because no outside consultants were used in its design
or inspection. The owner is very familiar with construction practices
(he can operate any piece of heavy equipment) and he was, therefore,
uniquely qualified to monitor the site’s design and to personally head
all quality control during construction. Thus, no opportunity existed
for the objectives of the owner to become diluted by being implemented
by another party.
Miscellaneous Factors Contributinci to the General Success of a Facility
• While subsidence cannot be eliminated entirely, it can be minimized
greatly by proper operating procedures, mainly compaction of the daily
lifts of wastes. At the Lanchester facility, the individual cells are
deeper than at most comparable facilities -(about 15 to 20 feet versus
about 8 feet).
• Leachate recycling to the waste pile is not considered a desirable
action, and at the Lanchester facility, all leachate is collected and
treated on site by a wastewater treatment plant. Prior to construction
of .the treatment facility on site, the leachate was delivered to DuPont
Corporation for handling.
• Waste held in the facility is far from its field moisture capacity,
and leachate flows are low, particularly in the summer. To further
minimize leachate production, liquids are not permitted into the
facility. However, leachate flows are expected to increase, especial-
ly once the field capacity of the waste is exceeded. Water generated
as a product of biological degradation will also contribute to the
leachate flow.
• Water can move predominantly upward through the waste pile if evapora-
tion and capillary transport are great enough.
• The asphaltic concrete liner is not susceptible to damage by frost.
Once only partially full, the frost line does not even reach the liner.
Newly lined sections are not threatened either because there is usually
little water entrained in the subbase.
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Lanchester Corporation
Page 4
Perspectives on Caps
• There are no completely closed fields at the Lanchester facility,
although one has a temporary cap constructed of carefully selected
native soils. A large variety of soils are locally available and one
suitable for nearly any purpose can be found.
• One of the principal reasons for eliminating disposal of liquids in a
land disposal facility is to minimize subsidence. For example, when
drums are disposed, they eventually corrode and empty their liquid
contents. The resulting large void formed is a point where subsidence
will occur.
• The effectiveness of caps in general, and particularly of those con-
structed of soils native to the Lanchester site, is demonstrated by
the capping of an abandQned dump site. This site existed long before
the Lanchester Corporation purchased the property, and leachate flowed
uncontrolled over a nearby public road, staining it brown. A cap con-
sisting of a 3- to 4-foot thickness of carefully selected native soils
was constructed and mounded for subsidence control A cutoff trench
was provided to intercept any continuing leachate flow and transport
it for treatment. Since the cap was constructed, leachate has not con-
tinued to escape the waste pile, although on occasions, holes requiring
repair have developed. All such caps require periodic inspection and
repair. The distinct color of the leachate from this particular facil-
ity simplified detection of any problems.
Perspectives on Regulations
• Most EPA regulations are appropriate, but some create unnecessary hard-
ships on landfill owners. The following are examples:
- There is no need to document every step taken during design and
construction of a land disposal facility. Most matters should be
left to the discretion of a professional engineer.
- Some requirements have no bearing on the performance of a land dis-
posal facility. Paperwork especially seems to have become an
obsession, assuming even greater importance than the facility itself.
- Groundwater monitoring is a legitimate need, but its characterization
should be limited to a few variables such as TOC, COD, and volatile
solids. If these parameters indicate a larger problem, more detailed
analyses including metals are justified. Detailed analyses made on
a routine basis is effectively forcing the facilities to support EPA
research, which is not an appropriate role for the facilities. This
increases costs, thereby potentially driving customers to use alter-
native and clearly less desirable disposal methods.
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Lanchester Corporation
Page 5
• Regulatory officials, particularly those who work directly with the
land disposal facilities, should be required to have some minimum
practical experience as this will enable them to better appreciate
‘real world” problems.
• Performance standards may have some merit as a mechanism to encourage
owners to construct better facilities since when a poorly constructed
facility fails, remedial action may not be adequate to completely
restore the site.
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ASSESSMENT OF TECHNOLOGY FOR CONSTRUCTING AND
INSTALLING COVER IkND BOTTOM LINER SYSTEMS
FOR HAZARDOUS WASTE FACILITIES
EPA Contract No. 68-02-3174; Work Assignment No. 109
INTERVIEW NO. B-6
Monsanto Polymer Product Co.: Jerry N. McGuire TRW: Masood Ghassemi
St. Louis, MO 314-694-5262
2 February 1983
Sunima ry
• Based on the company’s poor experience with the installation and per-
formance of synthetic liners in a wastewater lagoon lining application,
clay was selected as the choice liner material in a subsequent landfill
lining job at another company site.
• Experience indicates that the present practice and technology will not
guarantee installation of synthetic liners that will not fail.
Background
On 20 December 1982, TRW informed Dr. Janet Matey of Chemical Manufac-
turers Association (CMA) of the subject study which TRW had just initiated
for EPA. CMA was requested to bring the study to the attention of its member
companies so that interested members could provide input to the program, if
they so desired. A copy of the work plan was subsequently sent to CMA.
On 2 February 1983, Mr. Jerry N. McGuire of Monsanto telephoned TRW and
provided the information presented in this interview summary report. To
date, Monsanto has been the only company responding to the TRW-CMA request
for input to the subject study.
Although Monsanto provides sheet materials for miscellaneous uses, it
does not market FMLs. Mr. McGuire has designed both clay and synthetic
membrane liners for several of the company’s waste disposal facilities, and
the data provided here reflect his personal experience with the two types
of liners.
Description of Two Lined Waste Disposal Sites and Performance Results
• A wastewater treatment lagoon was originally lined with 30-40 mil butyl
rubber. The mastic material used on joints did not hold up and exhi-
bited only a 5-lb tear strength. The failed liner was later replaced by
a 20-mil DuPont 3010 liner. Heat welding was used for seaming in the
field. The experience with the second liner was also unfavorable.
• One landfill/land mound site which receives chemical sludges has a double
clay liner. The selection of clay over synthetic liner, which was
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Interview No. B-6
Monsanto Polymer Product Co.
Page 2
primarily influenced by the above-mentioned bad experience with synthe-
tic membranes, had to be justified to the state which initially favored
synthetic liners. The top and bottom clay liners are 18” and 12” deep,
respectively, and are separated by a 1-foot layer of sand containing
the leachate collection system. The 5-acre site consists of two opera-
ting cells: a ‘wet” cell which receives the liquid sludge and is used
as a drying bed, and a “dry” cell which is used for dry solids. The
top clay layer in the wet and dry cells are overlaid by a layer of sand
and a layer of gravel, respectively. Approximately one year after the
operation, leachate was detected in the intermediate sand layer. In the
five years of operation, the leachate generation rate has varied from 0
to 200 gallons per day. The quantity of water collected between the two
liners is directly related to rainfall. Constituent concentration
levels in the collected leachate from between the liners is 20 to 50
times lower than the levels in the leachate samples collected from above
the top liner, and these concentrations have been dropping. Although
the collected leachate is of a quality which can be directly discharged
to the river, the leachate is treated on-site in a secondary wastewater
treatment plant before it is discharged to the river.
Perspectives on Synthetic vs. Clay Liners
• Experience indicates that it is very difficult to install synthetic
liners which are free from pinholes or other faults (e.g., due to bad
seams).
• On liner installation jobs, the foreman usually hires local help with no
liner installation experience and this can lead to poor quality work and
hence failure.
• Heat welding may produce good results under office or laboratory condi-
tions, but not necessarily under actual field conditions. Field test
methods for confirming seam tightness have not been completely successful.
• Overall, clay liners would be superior to synthetic liners, assuming com-
patibility with the material they are meant to contain. Clay can be
installed in the field without encountering installation problems asso-
ciated with synthetic liners.
• Clay is definitely more suitable for use with heavy earth moving equip-
ment.
• Quality assurance in the manufacturing of synthetic liners has been a
problem. Monsanto has experienced difficulties with thickness, rein-
forcing scrim, material uniformity, etc.
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4.3 INTERVIEW REPORTS WITH STATE REGULATORY AGENCIES
C-i. New York State Department of Environmental Conservation
C-2. Pennsylvania Department of Environmental Resources, Bureau of
Solid Waste Management; and Lycoming County Planning Commission
C-3. Pennsylvania Department of Environmental Resources, Bureau of
Solid Waste Managemerft
C-4. Pennsylvania Department of Environmental Resources, Bureau of
Water Quality Management
C-5. New Jersey Department of Environmental Protection: Division of
Water Resources, Solid Waste Administration, and Bureau of
Hazardous Waste
C-6. Maryland Department of Health and Mental Hygiene, Office of
Environmental Programs
C-7. Wisconsin Department of Natural Resources, Bureau of Solid Waste
Management
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ASSESSMENT OF TECHNOLOGY FOR CONSTRUCTING AND
INSTALLING COVER AND BOTTOM LINER SYSTEMS
FOR HAZARDOUS WASTE FACILITIES
EPA Contract No. 68-02-3174; Work Assignment No. 109
INTERVIEW NO. C-i
New York State Dept. of : Mark Hans TRW: John Metzger
Environmental Conservation 716-847—4585 Sandra Quinlivan
Buffalo, NY
13 December 1982
Summary
• Most facilities in the region utilize a liner system consisting of three
layers: a base of clay; a synthetic, flexible membrane; and an upper
layer of clay.
• The following two requirements are essential to ensuring that a land dis-
posal facility performs satisfactorily: adequate quality control during
placement of the liner and a leachate collection system. The importance
of the leachate collection has been identified only recently.
• The regulations, as written, are sufficient to ensure an adequate facili-
ty but not so rigid to prevent innovations where appropriate.
• Direct experience is most important in advancing the state-of-the-art.
Most research is of lesser utility.
Background and Objective
The Division of Solid Waste Management of the State of New York, Depart-
ment of Environmental Conservation, is divided into nine regional offices.
Each retains design, operational and monitoring data of hazardous waste sites
within its region. In the Region 9 office (Buffalo), Mr. Hans is in charge
of permitting and, in some cases, inspecting various land disposal facilities.
Much of the experience represented by professionals in this office has been
acquired by working with either of two facilities that have national signifi-
cance: SCA Chemical Services, Model City, NY; and CECOS International, Niagara
Falls, NY.
The objective of the interview was to obtain perspectives of this state
office on use of liners in land disposal facilities. The following subject
areas were considered: (a) characteristics of typical facilities in the
region; (b) construction requirements of new facilities and the state’s in-
volvement; (c) assessment of liner performance and of the current regulations;
and (d) other references and data sources. Information presented in the
following sections represent opinions and, therefore, is not necessarily sub-
stanti ated.
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Interview No. C-i
NY State Dept. of Environmental Conservation
Page 2
Design Considerations and Acceptable Standards of Practice
o The following summarizes liner systems typical of land disposal facili-
ties in Region 9, NY. Most details are nowhere stated explicitely in
regulations, but a system conforming approximately to the following is
the norm understood by parties seeking a landfill permit. Landfills are
constructed with the following layers:
- First, a 2-foot thick layer of compacted clay overlying a synthetic
liner.
- Next, a synthetic, flexible membrane. Most older facilities use
Hypalon. Newer facilities use high density polyethylene (HDPE), lar-
gely in response to it being promoted by consulting engineers as a
material that is easier to handle and install. Most HDPE liners are
60 to 80 mils thick.
— Last, a 10-foot base layer of clay having permeability less than l0
cm/sec.
O Compatibility testing of the liner with leachate is not required in the
region, nor is there any known requirement elsewhere in this part of the
country. However, it was emphasized that the liner is protected by the
clay cover.
o There are many factors requiring consideration when siting or designing
a landfill. These include the following:
- The factor of potentially greatest influence is public opposition to
a new disposal site. Political problems can usually be minimized by
expanding an old facility or constructing a new site adjacent to an
old one.
- Areas where clay occurs naturally are preferred. Some deposits in
the region approach a thickness of 20 feet.
- Generally, a vertical distance of 10 feet is required between the
groundwater and the waste deposit. Some facilities, such as the CECOS
International landfill near Buffalo, are located almost on bedrock
and up to 10 feet of clay must be trucked into the site prior to
placement of the synthetic liner. Certain recent designs referred to
as ‘intragradient’ are exceptions. For these, the groundwater eleva-
tion exceeds that of the base of the landfill, thereby exerting a
hydraulic gradient inward on the facility. If leakage occurs, it is
in the direction of groundwater migrating into the landfill.
Construction Requirements — State Involvement
• Three persons from the state office are on-site at all times during con-
struction to oversee operations. An engineer from the state is present
on a less frequent basis.
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NY State Dept. of Environmental Conservation
Page 3
• There is no requirement that contractors installing liners be licensed.
However, each contractor is required to certify that the system complies
fully with design specifications.
• A soils engineer, responsible to the owner, supervises quality control
activities. One important duty is supervision of conipaction/recompaction
of clay. Clay lifts are limited to 6 to 9 inches, and a compaction test
is made at 50-feet intervals using a nuclear densitometer to verify 90
percent compaction.
• HDPE liners are seamed by heat welds. The material is overlapped and a
weld is made along the edge on both sides. All welds are tested by
applying air under pressure to the natural gap created by the two welds
and measuring the leakage. Alternatively, the welds are tested by a
sonic method which measures the thickness of the seam and correlates this
to seam integrity. Hypalon is usually seamed by solvent welding. Test-
ing is done manually by simply attempting to pull the sections apart.
Perspectives on Liner Performance
• Substantive regulation of landfills in the region began in about 1976.
Few leachate problems generally occur due to the following measures: use
of a liner and a leachate collection system and elimination of land-
filling liquids.
• No landfill in the region has an elaborate leak detection system. With
the intragradient designs, leakage is indicated by excessive generation
of leachate. For other systems, leakage is indicated only by over-
whelming evidence.
• Placement of the liner and quality control are the most important acti-
vities during construction to guarantee satisfactory performance in the
future. The most important design feature to likewise ensure performance
is the leachate collection system. By minimizing contact between the
leachate and the liner, there is less opportunity for the liner to be
degraded or for leachate to escape the facility if a hole has already
developed in the liner. The important role played by leachate collection
has been identified only recently as evidenced by it being required over
only the past 1-1/2 years.
• Mechanisms of failure are not usually well understood. Few problems have
occurred in the region. One exception is failure of a cell (Cell 7) at
the SCA facility. There, a portion of the sidewall collapsed, creating
a tear in the Hypalon liner.
Perspectives on Regulations
• The current regulations as well as construction and installation practices
are judged adequate. The regulations are also sufficiently flexible to
permit an equivalent system to be substituted for the current typical
design. The state office is receptive to innovations so long as perfor-
rnance can be assured.
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Interview No. C-i
NY State Dept. of Environmental Conservation
Page 4
Research Needs
• No suitable areas of research could be identified, and much of the current
research was considered of questionable value. An example is provided by
water balances around the disposal site. Such balances are made in this
region, if at all, upon closure of the facility. However, too many
variables are involved or are very difficult to quantify to permit formu-
lation of a reasonable model describing landfill performance.
• The most important advances in the state-of-the-art result from compiling
direct experience. There is no suitable substitute.
• Land disposal is an evolving technology with innovations occurring regu-
larly. Owners are probably in. the best position to push innovations as
they are most directly influenced by, and therefore most responsive to,
economic and political pressures.
• An example of a recent innovation is provided by a new SCA facility in-
corporating a “continuous design”. The facility will cover approximately
25 acres, but only 4 or so will be opened as needed, Leachate collection
systems will operate independently in each section of the facility.
Additional Suggested Contacts
The following individuals were identified as having extensive experience
in the indicated areas:
• John Beecher. Mark Hans’ supervisor, who was characterized as having
extensive field experience.
• Paul Counterman (518—457-3273). He is in the Albany state office and has
experience writing hazardous waste disposal regulations. (Note: Paul
Counterman was contacted by telephone and can provide TRW with additional
data on liner performance at the following sites: (a) Town of North
Hempstead, NY, which has a 20-mu PVC liner and has had liner problems;
(b) Rotterdam landfill which has a silty clay liner; and (c) Colony land-
fill which also has a silty clay liner.)
• Jim Woods, Wheran Engineering, Inc. He should be contacted for details
of liner design and construction, and regarding compatibility studies, and
for details of recent slope failure in Cell 7 of SCA’s landfill.
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ASSESSMENT OF TECHNOLOGY FOR CONSTRUCTING AND
INSTALLING COVER AND BOTTOM LINER SYSTEMS
FOR HAZARDOUS WASTE FACILITIES
EPA Contract No. 68-02-3174; Work Assignment No. 109
INTERVIEW NO. C-2
PA Dept. of Environmental : Richard L. Bittle TRW: John Metzger
Resources, Bureau of 717—327-3653 Sandra Quinlivan
Solid Waste Management
Williamsport, PA
Lycoming County : Jerry S. Walls
Planning Commission 717-327-2230
Williamsport, PA
15 December 1982
Summary
• The Lycoming County facility is a sanitary landfill which utilizes a
liner system consisting of the following layers constructed atop in-
situ clay: two 12-inch sand layers separated by a PVC membrane and an
overlying layer of 12-inch compacted clay. PVC has been selected due
to its proven performance and relatively low cost.
• The PVC liner was not tested for compatibility with leachate, largely
because leachate characteristics were poorly understood initially. Reco-
very and testing of a section of the liner after four years of operation
showed liner characteristics almost identical to the new material.
• Favorable experience with the PVC liner is attributed to good design,
not accepting certain potentially incompatible wastes, and removal of
the leachate from the landfill.
• Not all factors contributing to an adequate landfill facility are tech-
nical. Carefully structured legal arrangements, including assigning of
liability, can be invaluable for ensuring quality construction and promo-
ting effective quality control during all aspects of liner design, fabri-
cation, and installation.
Background and Objectives
The Lycoming landfill is a sanitary landfill operated since 1977 under
the supervision of the Pennsylvania Department of Environmental Resources and
the Lycoming County Commissioners. It is a major landfill in the region and
is located on land which is part of a minimum security state prison. There
are three fields: Field 1 is at capacity and closed, Field 2 is being filled,
and Field 3 is under construction. The site uses a PVC liner which is re-
ported to perform very satisfactorily. The objectives of the interview were
to obtain information on: (a) the design, operation, construction, and per-
formance of PVC liner at the Lyconhing facility; (b) perspectives of the state
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Interview No. C-2
PA Dept. of Environmental Resources
Lyccming County Planning Commission
Page 2
and county commissioners/site operators on liner performance and current
liner regulations; and (c) additional references and data sources to be con-
tacted. Part of the data is specific to the Lycoming facility, while the
rest represents the broader experience of both Mr. Bittle and Mr. Walls who
were interviewed.
Design and Operation of the Lycoming County Sanitary Landfill
• The Lycoming sanitary landfill has a liner system consisting of the
following layers of materials:
- A base of limestone overlain with in-situ “glacial” clay. The site
has an abundance of natural clay.
- A 12-inch layer of sand. This layer is included as part of a monitor-
ing and leak detection system. Underdrains are laid in trenches ex-
cavated into the in—situ clay. Any leachate escaping the overlying
liner can migrate laterally through the sand layer to an underdrain.
- A flexible membrane. The synthetic liner is 20-mu PVC except in the
vicinity of gas vents where it is 50-mu thick. PVC was selected
because it was economically superior to all other liner materials con-
sidered. For the first project at Lycoming, the fabricator was
Watersaver Company (Denver, CO), and Staff Industries (Montclair, NJ)
was used for the second.
- A 12—inch layer of sand. Earlier projects used a 6-inch layer, but
12 inches was found to be superior, strictly from a construction
standpoint.
- A 12-inch layer of compacted clay.
• A liner system must receive close attention during construction if it is
to perform adequately. A number of measures were taken at the Lycoming
facility to ensure the quality of construction, including the following
two arrangements:
- The contractor was required by the project specifications to post a
construction guarantee, and the contract was structured so that the
contractor was designated liable at every step of his involvement in
the project. For example, the contractor was required to ensure that
all materials received from the fabricator met specifications. Such
a system of liability could be arranged only by eliminating the pro-
ject from its tax-exempt status normally given a government project.
However, this structure was considered necessary to ensure tighter
definition of responsibilities and, therefore, an increased likelihood
of the project being completed satisfactorily.
- A warranty was required for the flexible membrane, and a draft had to
be presented up-front with all bids. The warranty was a replacement
warranty , meaning that if failure occurs prior to the end of the
service life of approximately 20 years, adjustments would be pro-rated
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PA Dept. of Environmental Resources
Lycoming County Planning Commission
Page 3
over the period of successful service. In reality, such a warranty is
of limited usefulness, mainly because of the difficult task of proving
failure and assigning responsibility. However, it serves another very
important purpose: should major problems occur requiring litigation,
the matter is one for contract law, a legal area having extensive pre-
cedent, rather than “landfill law” or some other equally unchartered
legal area.
• Approximately 700 tons of input waste are handled each day, with all
wastes screened to protect the liner. Rejected materials include aromatic
solvents and cutting oils which must be handled by a hazardous waste
facility. Even entire truck-loads of undesirable deliveries have been
turned away on occasion. Acidic industrial sludges are neutralized with
lime prior to emplacement in the landfill, but sludges having less than
20 percent solids content are not accepted. Inert fillers, such as
sawdust or “stay-dry” or auto repair shop oil spill adsorbent materials,
are occasionally added to increase the solids content of waste materials.
• Runoff is routed around the landfill by means of diversion trenches.
• Operating units within the landfill are closed using a cap of clay only.
• Removal of leachate from the facility helps to ensure the long-term inte-
grity of the liner. Leachate is collected (about 40 gpd) by a network of
lateral pipes and routed to a holding basin lined with 30—mil PVC. There
it is mechanically aerated via two aeration pumps and, in the past, was
sprayed onto the surface of the landfill. In the future, the leachate
will be hauled in 5,000 gallon loads via vacuum trucks to a WWT plant in
Williamsport (the possibility of building a new leachate impoundment
lagoon complete with settling and flocculation capabilities was studied,
but the costs were found prohibitive for a county-run landfill). Fluorine
has recently been approved for use as a tracer element to indicate leakage.
• At the time of the first landfill project at the Lycoming site, there
were no regulations requiring compatibility testing of the liner. Addi-
tionally, the state-of-the-art was in its infancy; there was little or no
information on leachate characteristics. Research by Henry Haxo of
Matrecon was only beginning. A. Tungaroli’s work on leachate character-
istics was being done at Drexel Industries, but these were laboratory-
scale, not field tests. Such laboratory-scale studies were considered to
be of debatable value since they rarely represent field conditions.
However, in an attempt to ensure some minimal guarantee of compatibility
between the liner and leachate, leachate characteristics based on the
best available information were included in the bid specifications.
• Characteristics of the leachate have been monitored since start-up, and
no evidence of incompatibility between it and the liner has been found.
For the most recent field, now under construction, some compatibility
tests were available to assist in selecting the liner. However, the
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Interview No. C-2
PA Dept. of Environmental Resources
Lycomirig County Planning Commission
Page 4
eventual choice of PVC was based more upon successful field experience
with this material than on compatibility or other testing.
• A section of the PVC liner from Field 2 was dug up after approximately
four years of service in response to pressure exerted by the “Organization
for Ecology”, a local citizens’ group. The section met all specifications
of the new material with exception of the low temperature (-20°F) test.
However, this test is considered somewhat irrelevant since the site only
gets a 36-inch frost (0°F), and the liner is under at least 12 inches of
clay and 12 inches of sand, except on the slopes.
• Problems have occurred with leachate breaking out the side of the land-
fill mound at a point above the reach of the bottom liner. This movement
is believed to result from the daily cover material of clay restricting
downward flow. Instead, channels of lower permeability develop laterally,
resulting in a like movement of leachate and eventual break—out at the
side.
• Water initially collected from the incompleted underdrain system at
the Lycoming facility had shown increasing conductivity (up to 3-4,000
mg/l), but this was less than the conductivity of the leachate. Some
of this increase may have resulted from lime that had been used on
service roads for dust control. There had also been construction acti-
vities at the site which may have stirred up soils containing naturally
high levels of iron and magnesium. Finally, animals are known to crawl
into certain drains at the facility since dead ones have been flushed
out on occasion. Decay products may have contributed to the increased
conductivity. Recent monitoring of the completed, vented underdrain
system showed decreases in the conductivity measurements (1,600 mg/l).
• No adverse impacts to aquatic life were detected in a recent aquatic
survey of a stream downgradient of the landfill. Also, deep ground-
water monitoring wells have shown no evidence of contamination to date.
Perspectives on Liner Installation and Performance
• Clay liners are used very little in the region. No such facilities
could be cited.
• For liner systems having sand layers constructed adjacent to the flexible
membrane for cushioning, such as at the Lycominci facility, the character-
istics of the sand must be controlled carefully to eliminate any material
that might puncture the membrane. The sand should have a gradation with-
in the following approximate limits:
- 90 percent passing #4 sieve;
- 0-30 percent maximum, passing #200 sieve;
- 0-15 percent maximum, passing #2000 sieve.
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Interview No. C-2
PA Dept. of Environmental Resources
Lycoming County Planning Commission
Page 5
The sand grains should be well weathered to minimize abrasive contact
with the flexible membrane, and all sand lifts should be spot-checked to
ensure conformance with the specified gradation. Pockets of off-spec
material sometimes occur in the original deposit from which the material
was taken.
• Liner installation is particularly difficult during conditions of high
wind. The sheets are large (approximately 100 feet by 270 feet) and are
easily lifted by a strong wind.
• Manufacturers have been known to make unauthorized substitution of mate-
rials to use up inventories. This problem is not common but can usually
be avoided entirely by monitoring purchase orders at all levels.
• PVC is seamed by solvent bonding, and all seams are tested by a portable
air compressor and wand. The contractor is required to furnish this
equipment, but frequently not enough is available on-site to allow testing
of seams to keep pace with placement of the liner. The permit specifica-
tions should, therefore, be modified so that the owner can designate the
number of pieces of equipment for leak checking that must be on site.
• The inspector is the owner’s direct representative responsible for QA/QC,
and the contractor should fully interface his operations with the inspec-
tor while seams are being checked. Repairs can then be made quickly as
leaks are located, thereby minimizing greatly the chance of repairs being
overlooked entirely.
• All factory welds should be checked for leaks in the field after the liner
is in place. This, typically, is not done.
• Creases in the installed liner should be patched or filled with a caulking
compound of polyurethane. After it has set, no difference should be dis-
cernable between the caulking and the surrounding PVC.
• The first lift of waste into a newly-constructed facility (that is, the
material contacting the exposed surface of the bottom liner) should be
screened carefully to eliminate materials that might puncture the flexible
membrane.
• Operating errors are sometimes also responsible for tears in the liner, a
typical incident being improper handling of heavy equipment. PVC repairs
more easily in the field than most liner materials. Hyoalon repair is nota-
bly difficult and effectively impossible under conditions of high moisture.
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Interview No. C-2
PA Dept. of Environmental Resources
Lycoining County Planning Conimission
Page 6
Perspectives on Regulations
• No improvements to current regulations could be suggested with exception
of better definition of the sand when such a layer is constructed facing
the flexible membrane. The sand characteristics (depth, type, gradation)
need to be carefully specified to eliminate any possibility of the layer
puncturing the liner.
• Some problems have occurred with installers, but none have been serious
enough to warrant a licensing program.
Perspectives on Research and Development Needs
• New product development is suggested to concoct a caulking compound for
field repairs of PVC (especially for covering creases) that has charac-
teristics more closely resembling the liner material.
• The permeability of various liner materials needs to be determined better
than the typical specification of a range of values with a lower limit.
Such information would be more useful for needed calculations projecting
movement of materials.
• It is difficult to correlate the characteristics of leachate with mate-
rial contained in the facility. With the Lycoming County facility, for
example, it is very uncertain exactly what has gone into the facility.
With the exception of a number of industrial accounts, most of the mate-
rial can be classified no better than as garbage, and the exact composi-
tion of this material is undeterminable. But even with the industrial
accounts, the wastes received are only classified generically, the intent
being mainly to ensure compatibility of the material received with others
already held in the facility.
Miscellaneous
• Some of the current workers at the landfill are working off light sen-
tences imposed under the state criminal justice system for crimes such
as shopliftino, or are under various CETA-funded programs. Such workers
are occasionally careless with heavy operating equipment, which sometimes
results in liner damage.
Additional Suggested Contacts
Dr. Richard Dickenson; Dynamit Nobel-Harte, Inc.; Auburn, NY;
315—253-4433; for additional data on PVC liners.
Dr. Charles Staff; Staff Industries; Monte Claire, NJ; for liner fabrica-
tion information.
Bill Slifer; Watersaver Company, Inc.; Denver, CO.
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Interview No. C-2
PA Dept. of Environmental Resources
Lycoming County Planning Comission
Page 7
Reference Documents
Copies of the following reference documents were provided to TRW:
• “Controlled Sanitary Landfill, Allenwood Site, Lycoming County, PA”; Con-
tract Documents for Field III Construction, June 1982, and Section B Bid
Forms.
• Addendum No. 1 to Contract Documents.
• Section 26. Sealing Existing Borings.
• Copies of Contractor’s Financial Statement, Plan and Equipment Question-
naire and Experience Questionnaire.
• Target Schedule for Preconstruction Events.
• Transcript of Environmental Hearing Board Adjudication for Brary Township,
Gregg Township and Elizabeth Steward vs. Commonwealth of Pennsylvania,
Dept. of Environmental Resources and Lycoming County Commissioners,
Docket No. 74-246-W, August 7, 1975.
• Lycoming County Landfill “General Plan” (Blueprint).
• Letter from R.H. Dickinson, Marketing Manager, Dynamit Noble—Hart, Inc.,
to Mr. Jerry S. Walls, Lycorning County Planning Commission, regarding
specification testing of 4-year old sample taken from the landfill PVC
liner.
• Sample “Module 1” waste input form.
• Listing of Waste Generators disposing of wastes at the Lycoming landfill.
• Sample leachate analytical data for May 1978 to October 1979.
• Sample groundwater monitoring well analytical data, quarterly analysis,
dated 4 December 1981.
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ASSESSMENT OF TECHNOLOGY FOR CONSTRUCTING AND
INSTALLING COVER AND BOTTOM LINER SYSTEMS
FOR HAZARDOUS WASTE FACILITIES
EPA Contract No. 68-02-3174; Work Assignment No. 109
INTERVIEW NO. C-3
PA Dept. of Environmental Dennis C. Orenshaw TRW: John Metzger
Resources, Bureau of 215-631-2420 Sandra Quinlivan
Solid Waste Management,
Norristown, PA
16 December 1982
Summary
• In installing asphaltic liners, fluid application temperatures should
be maintained above a minimum temperature in order to maintain low
viscosity. Since asphalt adheres to rollers during the rolling opera-
tion, better results are obtained when two applications are made at
half rate rather than one application at full rate, by having the
spray nozzles on the spray truck mounted on the sides of the truck
rather than on the back.
• Incoming residual wastes should be screened for oil content, and a
maximum concentration level should be established.
• In installing synthetic liners, seams should have one-foot overlap to
ensure adequate bonding. On sloping sides, overlaps should allow drain-
age away from the seam rather than into the seam.
• Most landfill facilities in the region have liners that are constructed
of several layers. The installation of the primary liner, whether it
be PVC, asphalt or other material , and the clay base which supports it,
are the most crucial elements in the development of an adequate facility.
• The state’s involvement during construction varies. In some cases, re-
sponsibility for QA/QC has not been independent of the contractor. The
only independent check remaining then is the landfill owner, and his
technical expertise or interest in the project may be somewhat lacking.
• Exhausted facilities are capped with permeable soil to encourage water
to flow into the pile. Contact between the held waste material and the
water is believed to promote stabilization. The majority of the total
leachate production therefore occurs within a short period after the
facility is capped, which corresponds with a period during which the
liner is probably more resistant to corrosive conditions.
• Subsidence at older landfills is more the result of poor compaction
practices than the construction of caps.
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Interview No. C-3
PA Dept. of Environmental Resources
Bureau of Solid Waste Management
Page 2
Background and Objectives
The Pennsylvania Department of Environmental Resources is divided into
six regions. The Norristown regional office, which was visited, has jurisdic-
tion over all state Region 1 landfills, including the following 10 facilities:
- Grows Landfill; Bocks County, PA
- Boyertown Landfill; Montgomery County, PA
- Western Berks Landfill; Berks County, PA
- Montgomery County Landfill; PA
- Pottstown Landfill; Montgomery County, PA
- Strasburg Landfill; Chester County, PA
- Knickerbocker Landfill; Chester County, PA
- Cloverdale Landfill; Berks County, PA
- Grand Central Sanitation; PA
- Brooks Landfill; PA
Of these sites, the most complete information is available for the Grows,
Boyertown, and Stroudsburg landfills*. The Grows and Boyertown landfills have
interim hazardous waste permit status. The Strasburg facility is primarily
a sanitary landfill. The remaining landfills are municipal landfills for
which little detailed data are available. The Grows landfill has a PVC liner
which is underlain by 10 feet of clay. The Boyertown landfill has an asphal—
tic liner. The Strasburg site is also PVC-lined. Each facility has leachate
collection by clay pipes draining to sumps.
The objective of this interview was to obtain an overview of the liner
design and installation problems from a state regulatory perspective. The
statements and assertions made reflect the experience with design, construc-
tion, and operation of the landfills under jurisdiction of the State Region 1
office.
Landfill Design and Operation
• Most landfills in the region utilize a liner consisting of a system of
layers. The following cross-section is typical (layers in order of in-
creasing elevation):
- Clay base.
*
The very voluminous and extensive state data files on these landfills, which
include design information, were made available to TRW for review and/or
photocopying during the visit. Because of schedule constraints, however,
detailed review or obtaining photocopies had to be postponed to some future
occasion.
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PA Dept. of Environmental Resources
Bureau of Solid Waste Management
Page 3
- Layer of MC 30. This is a thin oil having the consistency of dirty
motor oil. Its purpose is to provide a break in permeability between
layers.
- Sand/gravel layer. This zone contains pipes and related appurtenances
of a leachate detection system.
- Liner. A synthetic membrane.
- Flow layer. This layer contains a network of leachate collection
pipes. Permeability is about 10—4 cm/s.
• The clay base is an essential part of a successful facility. An added
margin of safety is provided by the synthetic membrane. The installa-
tion of the primary liner, whether PVC, asphalt or other material, and
the clay base which supports it, are the most important elements in
landfill design.
• Most landfill facilities in the region collect leachate and recirculate
it to the top of the pile (applied by spraying) during the operational
life of the facility. Once capped, the leachate is either held in a
suitably constructed holding pond or, preferably, is routed to a POTW.
At the Grows landfill, there is an on-site wastewater treatment plant
with a complete aeration system; treated wastewater is discharged to the
Delaware River. Leachate from the Boyertown and Strasburg sites is
hauled off-site to hazardous waste treatment facilities. Very little
leachate is generated at the Strasburg landfill because it is a new
site.
• Caps are constructed of permeable soil only. Precipitation is thereby
intentionally encouraged to enter the facility. This helps to stabilize
the waste material and results in the largest volume of leachate being
generated when the liner is new and probably better able to resist the
corrosive characteristics of the leachate. Accelerating the rate of
waste stabilization is considered appropriate since the long-term inte-
grity of flexible membranes is highly uncertain.
• At most of the newer facilities, caps have been constructed carefully
and little subsidence has occurred. At older facilities in the region,
however, marked subsidence has often occurred. In an extreme case,
slumping occurred at the Grows site. In general, the subsidence at
older landfills is more the result of poor compaction of input wastes
than the construction of caps.
Liner Installation and QA/QC
• Asphaltics are difficult to install as liner materials. During applica-
tion, the material must be maintained above a minimum temperature to
maintain low viscosity. Transfer from transport truck to application
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Interview No. C—3
PA Dept. of Environmental Resources
Bureau of Solid Waste Management
Page 4
truck is difficult when the material is cold, and the spray bars on
the applicator tend to freeze up. Cold and inclement weather there-
fore can play a prominent role during installation. Asphalt also
tends to adhere to the rollers during rolling operations. In addi-
tion, truck tires have a tendency to kick the material up and create
small holes and bubbles in the surface. One cannot make two passes
over the same area with the spray bar mounted on the back side of
the truck. Two applications at half rate (possibly when the spray
bar extends from the side of the truck) produce a better liner than
one application at full rate. This side-spray technique was put into
practice at the Boyertown site. Asphalt is not necessarily difficult
to install, and rolled asphalt is not used. All materials (such as
ACP-1 or AC-20) are sprayed and then harden into a thin layer of
approximately one-half inch in thickness.
• The state’s involvement during construction varies. A representative of
the state is usually on-site on a daily basis, although during liner in-
stallation, additional inspections may be performed. In some cases, an
inspection of the site is made by a special technical representative upon
completion of each layer of the base.
• In some cases, no QA/QC has occurred independent of the contractor’s in-
ternal program. Only the landfill manager can then ensure compliance with
specifications, but he does not necessarily have the technical expertise
needed to do an adequate job.
• Two specific field tests were noted as part of QA/QC:
- Falling head/standing head permeability test.
- Inspection of seams, visually only, for adequacy of gluing and to
ensure that there is a one-foot overlap of PVC layers at the seams
which slope downward.
• The Strasburg landfill currently has an application for a huge expansion
under consideration by the state. As a supplement to their file, county
personnel have put in recommendations for better inspection procedures and
schedules during site construction and liner installation.
Siting Considerations
• One of the more significant siting considerations is the availability of
cover material. Prior to being permitted, there should be an exact
accounting of cover material, not merely an assurance that all needed
material will be shipped in.
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Interview No. C-3
PA Dept. of Environmental Resources
Bureau of Solid Waste Management
Page 5
• Nearly all other criteria typically considered when siting a new facility
are of marginal value. So long as regulations are complied with, a facil-
ity can probably be sited at any location.
• Political problems accompanying siting of a new facility usually far out-
weigh technical problems.
Compatibility Testing Requirements
• New regulations for hazardous waste landfills require compatibility test-
ing. However, there seems to be no “clear-cut” policy on compatibility
testing requirements at either the state or federal levels. The state
has developed certain general guidelines. One example is that waste oils
are not allowed at sites (e.g., Boyertown) with asphaltic liners, since
the oil may dissolve the asphaltic material. Microphotographs of Boyer-
town leachate in contact with the asphaltic liner have recently been
submitted to the Harrisburg regional office for analysis; no results or
comments have been received to date by the Norristown office.
Perspectives on Regulations and Miscellaneous
• In general, current landfill regulations are considered adequate.
• Maximum concentration levels of oil in incoming wastes should be esta-
blished for landfills with different types of liner systems.
• The concept of failure is nebulous and needs better definition. (What
constitutes failure?)
Additional Suggested Contacts
• It was suggested that the following individuals be contacted for addi-
tional information on liners and compatibility testing:
— Dwight Worby/Douglas Lorenzen
PA Dept. of Environmental Resources, Bureau of Solid Waste Management
Harrisburg, PA. Telephone: 717-787-7383
• For blueprints and mylars of the Strasburg landfill:
- Martin and ? ‘lartin, Inc.
149 E. Queen Street, Chambersburg, PA 17201
Available Documents
The following documents can be obtained from the state office:
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Interview No. C-3
PA Dept. of Environmental Resources
Bureau of Solid Waste Management
Page 6
• For the Grows landfill
- Module 1 waste input forms
- Analytical data on influent to on-site wastewater treatment plant
- Analytical data on effluent from WWT plant
- Report on recommended 30-day compatibility test for Grows landfill
— General background documents on site design, construction, and opera—
ti on
• For the Boyertown landfill
- Module 1 waste input forms
- Leachate discharge reports
- Background documents on leachate collection system
— General background reports on site design, construction, and operation
• For the Strasburg landfill
- Module 1 waste input forms
- Leachate incident reports
— Background documents on site design, construction, and operation
— Letters and memoranda describing various landfill and leachate inci-
dents (e.g., waste spill mop-up operations with straw bales)
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ASSESSMENT OF TECHNOLOGY FOR CONSTRUCTING AND
INSTALLING COVER AND BOTTOM LINER SYSTEMS
FOR HAZARDOUS WASTE FACILITIES
EPA Contract No. 68-02-3174; Work Assignment No. 109
INTERVIEW NO. C-4
PA Dept. of Environmental : Michael Hospodar TRW: Sandra Quinlivan
Resources, Bureau of Water Andrew Kondis John Metzger
Quality Management Scott McDougall
Pittsburgh, PA Vince Luci
412-565-5091
17 December 1982
Summary
• Clay liners, particularly those of montmorillite clay, are preferred to
synthetics. Many of the wastes handled in the region are a by—product
of mining operations, and synthetic liners seem generally incapable of
resisting the highly acidic characteristics of these wastes. Clay is
also a locally abundant material.
• Some liner failures in the region occur as a result of subsidence. Many
landfills are located over areas of extensive deep mines, resulting in
highly unstable ground conditions.
• Regulations should be flexible to allow locational considerations such
as use of deep and surface mines for waste disposal and use of clay as
liner material.
Background and Objectives
The PA Department of Environmental Resources, Region 5, Pittsburgh Office,
has jurisdiction over several hazardous waste landfills which are sited in
abandoned strip mines or over deep mines. Although many of these landfills
are unlined, several of the larger and more recently active sites are clay—
lined. Three of these major sites - for which background reports, design data,
liner and/or leachate data are available - are the Mill Services, Inc. land-
fills near Bulger, PA and near Yukon, PA, and the Municipal and Industrial
Waste Disposal landfill near Elizabeth, PA. The objectives of this interview
were to obtain: (a) the design, installation, and performance of the clay
liners at the sites; (b) the perspectives of the regional office on liners and
associated problems unique to their geological terrain; and (c) additional
references and data sources. Much of the perspectives provided appears to re-
flect field experience and are qualitative in nature.
Principal Landfill Facilities Considered
• The Mill Services, Inc., Bulger, PA, landfill consists of two pits located
over deep mines. The first pit is older and unlined and is almost totally
covered with soil and bentonite; the second adjacent pit is only one year
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Interview No. C-4
PA Dept. of Environmental Resources
Bureau of Water Quality Management
Page 2
old and is lined with clay. Leachate (seepage) is diverted to a collec-
tion lagoon at the old pit; the new pit has a downslope French underdrain
system which leads to a settlement pond before treatment at a local WWT
plant and discharge to local streams. There are 10 monitoring wells to
different depths and aquifers around the site. Input waste is primarily
neutralized pickle liquor. The raw waste is neutralized with lime, floc-
culated with a polymer and aerated prior to emplacement.
• The Mill Services, Inc., Yukon 1 PA, landfill consists of five landfill
“lagoons”, all located over a deep mine. One of the lagoons (No. 4) is
lined with PVC. Another lagoon (No. 5A) is reportedly lined with ben-
tonite clay. The remaining three lagoons are presently inactive. None
of the lagoons has a real system of leachate collection or treatment on—
site. Liquid supernatant from lagoon No. 4 is occasionally pumped to
wastewater treatment system. A few minor surface seeps of leachate have
been observed near the lagoons. Input waste is primarily neutralized
pickle liquor and some organic wastes. There are no monitoring wells at
the site.
• The Municipal and Industrial Disposal Co. landfill near Elizabeth, PA,
occupies an abandoned strip mine. The site is bentonite clay-lined and
has an extensive underdrain leachate collection system which leads to a
holding lagoon. Leachate is removed periodically by vacuum truck and
taken to a local WWT plant.
Perspectives on Liners
• As evidenced by their performance at the major landfills in the area,
clay liners are preferred over synthetic liners because of the local
availability of clay soils and because some synthetic liners (e.g.,
Hypalon) are incompatible with acid mine drainage and acidic wastes.
• Montmorillite clay is preferred because of its ion exchange capacities.
Vince Luci of the regional office, who is considered an expert on clay
liners, has studied various properties of this material and thinks very
highly of it. It should be utilized with a copolymer organic (e.g., an
acrylamide) which forms an organic linkage with the montmorillite clay
and retards its shrinkage or expansion.
• There are problems with liners in general in the region because of the
tendency for subsidence of the sites, many, of which are located over deep
mines.
• Each waste type must be evaluated individually against the clay liner.
The permeability and interlattice structure of the clay are the most
important factors affecting its performance. Synthetic liners are supe-
rior to clay liners from the standpoint of permeability.
• QA/QC is a most important consideration in any liner installation.
Efforts should be made to recheck measurements, to verify the integrity
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PA Dept. of Environmental Resources
Bureau of Water Quality Management
Page 3
of seams, etc. Unless the clay liner is properly installed, it is essen-
tially worthless.
Siting Factors
• The region is fortunate to have an abundance of surface and deep mines
for use in waste disposal. Attempts are made to use the in-situ condi-
tions and geology to maximum advantage.
Perspectives on Regulations and R&D Needs
• Current liner and landfill regulations are adequate and flexible, both
at the state and federal levels.
• EPA should not ban clay for use in liners.
• Additional compatibility testing needs to be performed between various
liner types and waste/leachate types.
• There is a need for the development of a synthetic liner which is high-
ly resistant to acidic wastes (e.g., acid mine drainage, pickle liquors,
etc.) which are commonly encountered in the region.
Additional Suggested Contacts
The following organizations/individuals can be contacted for further
information:
• Mr. Gary Berman, Vice-President; Mill Services, Inc.; Pittsburgh, PA.
Telephone: 413-343-4906.
• Mr. Vince Luci; Pennsylvania Department of Environmental Resources;
Pittsburgh, PA, for details of liner performance.
• EPA/FIT team files at Ecology and Environment, Inc.; Rosslyn, VA.
Reference Documents
The following documents were provided to TRW:
• Selected hazardous waste monitoring (groundwater) reports.
• Excerpts from several geotechnical reports describing site layouts.
• Selected waste input reporting forms.
• Selected seepage analytical reports.
• List of hazardous waste generators.
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ASSESSMENT OF TECHNOLOGY FOR CONSTRUCTING AND
INSTALLING COVER AND BOTTOM LINER SYSTEMS
FOR HAZARDOUS WASTE FACILITIES
EPA Contract No. 68-02-3174; Work Assignment No. 109
INTERVIEW NO. C-5
NJ Dept. of Env. Protection Merry L. Morris TRW: Sandra Quinlivan
Division of Water Resources: David Kaplan John Metzger
William Brown
609-292-0424
Solid Waste Administration : John Castner
• 609-292-7744
Bureau of Hazardous Waste Ernest Kuhlwein
David Scott
609-984-4061
20 December 1982
Sumary
• More confidence can be placed in clay liners than in synthetics. The long
term integrity of synthetic liners in contact with leachate is highly
uncertain, and the effectiveness of such a liner is also very sensitive
to careful control of construction practices.
• All liners leak; various quantities of leachate have been collected in
the leak detection system underneath the primary liner at several NJ sites
using Hypalon, Polyester BIDIM, PVC, DuPont 3110 primary liner and in—
situ clay.
• Lack of adequate quality control during installation is a key source of
subsequent problem with all liners. Accepting wastes which are incompa-
tible with the liner material is another potential cause of liner failure.
• Liner failures result most commonly from build-up of leachate. Many
landfill problems can, therefore, be avoided by providing a system to
quickly remove leachate from the facility.
• In assessing liner compatibility, data from carefully designed laboratory
tests must be supplemented with field data from operating sites, including
data on leachate generation rates and characteristics; such field data
currently do not exist and must be compiled.
• A large number of landfill facilities exist in the state, and for most,
there are problems. Even most controlled landfills in the state show
some organics in the surrounding groundwater.
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Background and Objectives
The New Jersey Department of Environmental Protection, Trenton, NJ, has
jurisdiction over approximately 160 operating landfills located throughout
the state. Some of these have clay or synthetic liners; most are small, un-
lined municipal sites situated on old sand and gravel pits. Of the 160 total
sites, approximately 20 are considered “problem” or “selected” sites. The
most complete information is available for the following six relatively large
and/or relatively new sites:
- DuPont; Carneys Point, NJ
- Monsanto Industrial Chemical Corp.; Bridgeport, NJ
— J.T. Baker Chemical Co.; Phillipsburg, NJ
- Toms River Chemical Corp. (now Ciba-Geigy); Dover, NJ
— N.L. Metals; Pedrickstown, NJ
— LiPari Landfill; Gloucester County, NJ
The first five of the sites are operating, secure hazardous waste land-
fills. The LiPari site is a closed municipal and industrial landfill. The
objectives of this interview were to obtain information on: (a) the design,
installation, and performance of various liners associated with the six sites;
(b) the perspectives of the various state offices on liner performance and
current landfill regulations; and (c) additional references and data sources
to be contacted. The perspectives presented largely reflect the experience
with operating landfills in NJ, in particular the six lined landfills for which
brief descriptions follow.
Principal Landfill Facilities Considered
• The DuPont landfill began operations in January 1979. It is a 15-acre
double-lined secure landfill consisting of three five—acre cells construc-
ted with two liners of 0.03-inch nylon-reinforced Hypalon and a leak de-
tection system between the two liners. Over 50 gallons of fluid per day
have been collected in the leak detector. The principal waste inputs are
dewatered primary WWT sludges and drummed and bulk solids from various
DuPont facilities.
• The Monsanto site was established in 1978 and consists of a 3-acre land-
fill, double-lined with 12-inch compacted clay and having a 0.9—inch poly-
ester BIDIM liner beneath the clay liners, and a leak detection system;
and a 3.5-acre, 33,000 cy capacity clay double-lined surface impoundment.
Within a month of start of operation, between 26 and 48 gallons of fluid
were collected in the leak detection system.
• The J.T. Baker landfill is a 2.5-acre, 60,000 cy capacity site which began
operating in 1979 and has two liners of 0.05-inch PVC film separated by
a leak detector, which accumulates leachate at a rate of one to three
gallons per day. The principal waste input is liquid WWT sludges.
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• The Toms River landfill was established in 1979 and was constructed
with a lower liner of 0.02-inch PVC and an upper liner of 0.03-inch PVC,
which are separated by a leak detection system. The leakage rate has
averaged between 60 to 131 gallons per day.
• The N.L. Metals landfill is a 5.7-acre, 145,000 cy capacity landfill
having a 20—mu thick DuPont 3110 primary liner and a 2—inch AC-20—coated
asphalt secondary liner. The site has a series of leak detector pipes
and leachate collection sumps. Collected leachate is hauled via vacuum
truck to an off-site wastewater treatment facility. The major input
waste is bulk kiln slag from secondary lead smelting operations.
• The LiPari landfill operated between 1958 and 1971, and is underlain with
natural clay. As part of closure, a bentonite slurry wall was construc-
ted at the site, and an impermeable cap will be installed in the future.
Passive gas venting systems will also be installed. There is extensive
leachate generation and there have been incidents of leachate contamina-
tion of surface waters (e.g. 0 Chestnut Branch and Rabbit Run) and ground-
water.
Liner Construction, Performance, and QA/QC
• State personnel generally prefer clay liners to synthetics. The long term
integrity of synthetics is a big unknown factor. Many sites (e.g., the
Parklands municipal and industrial landfill) try to take advantage of
natural clay liners, cut-off walls, or other natural features at the site.
• One of the principal problems with all liner systems is quality control
during installation. Technical problems of quality control are sometimes
compounded by landfill operators who are not fully aware of the problems
involved. Many operators are not patient with, do not fully appreciate,
or otherwise indirectly and unintentionally subvert quality control.
Some liners that are intact before installation can turn into “Swiss
cheese” during installation. Moreover, seaming methods that work well
under controlled laboratory conditions may not work well in the field.
Even small gaps/cracks in seams can cause big problems later.
• There are permit requirements for QA/QC testing, but the specific tests
utilized are fully at the discretion of the engineer on-site. In some
cases, the party responsible for QA/QC has not been independent of the
contractor/installer. On a continuing basis following construction, a
quarterly or annual certification is required of each facility by a pro-
fessional engineer.
• The principal problem causing failure of liners is build-up of hydraulic
head. It is, therefore, imperative that the leachate be collected, and
that such a system be properly maintained. Many of the sites in New
Jersey either have no drains or malfunctioning ones.
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Page 4
• Another feature helping to ensure a successful facility is careful control
over the materials that are placed in it. Despite legislation, some
smaller facilities continue to accept liquid waste materials. Especially
troublesome are septic tank pumpouts. These are notorious for their con-
tent of noxious materials and can, therefore, be highly corrosive to a
liner. However, disposal of this material by landfilling has been
practiced for many years and is not easily stopped.
a Subsidence varies greatly from site to site and is largely a function
of operating and placement practices, especially compaction to minimize
void spaces within the landfill.
• A public relations agent for DuPont was quoted saying that failures occurring
in the liners are a result of installation practices, not of the material.
• The 0.1—inch thick Vestalin liner manufactured by Schlegel has been re-
portedly used effectively in European landfills. The material is avail-
able j , n 0.5-acre sheets and seams are spot—welded.
( L ner Compatibility )
• Long-term compatibility of the liner with leachate needs to be better un-
derstood. Under the current system, an escrow account is established to
maintain each landfill for a period of 30 years. However, neither the
period of leachate generation nor the resistance of the liner to it are
known. Currently, the liner manufacturer is relied upon to provide com-
patibility data and guidance.
• Laboratory scale compatibility testing can be useful if carefully con-
ceived. However, the most useful research would consist simply of com-
piling more data from existing sites.
Siting Factors
• The majority of the existing landfills are situated on old gravel pits.
In siting new facilities, geological and hydrological factors are of
primary importance; soclo-political factors are secondary but are also
of great importance. The least amount of opposition is incurred when
existing landfills are simply expanded.
Perspectives on Regulations and R&D Needs
• All current landfills in New Jersey are required to have a liner and a
leachate collection system. The liner can be either synthetic or natural
material, but permeability through it must be less than l0 cm/sec. The
DuPont, Monsanto, J.T. Baker, and Toms River landfills, as well as most
new facilities, pretreat their collected leachate then discharge it to a
P01W.
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• The regulations should provide expanded monitoring requirements since
even mos t controlled landfills are showing some organics in the ground-
water. The present requirements are usually inadequate to interpret con-
ditions or events at a site.
• One area of particular interest for R&D is characteristics of the leachate
and especially its time variance. This is a difficult area because
numerous factors influence the generation and composition of leachate
(e.g., waste pretreatment, amount of rainfall, etc.), and little is
currently known about how and how long leachate is actually generated.
Leachate data for the Park Mills landfill may be useful in this type of
study.
Additional Suggested Contacts
• Because of the large number of landfills under their jurisdiction, it was
recommended that a large amount of additional detailed liner and leachate
information on selected sites could be obtained if TRW would prepare a
pseudo-questionnaire and circulate it among the 20-30 key state office
personnel who handle the various individual site files. This effort
would be performed with the assistance and under the direction of Dr.
Merry Morris, and with the concurrence of Ed Londres, Assistant Director
of Engineering and Permits Bureau.
• For additional information on the DuPont, Monsanto, J.T. Baker, and Toms
River Chemical sites, contact Mr. Angel Chang, Senior Environmental En-
gineer, NJ State Department of Environmental Protection, Bureau of
Hazardous Waste, 32 E. Hanover Street, Trenton, NJ, (609-984-4062).
• For information on a Rutgers University study on leachate plume forma-
tion, contact Jeff Hoffman or Kay Kassaback of the NJ DER, Division of
Water Resources, Trenton.
• For data on pretreatment and discharge to sewers, contact Kenneth Goldstein
of the NJ DER, Division of Water Resources, Trenton.
• For information on liner performance at several major NJ landfills, con-
tact Jim Bell of the NJ DER, Bureau of Hazardous Waste, Trenton.
• For data on various synthetic liners used in the area, contact Mr. Douglas
Fish, E.I. DuPont de Nemours, Kirk Mill Building, Wilmington, Delaware.
• Dr. Peter Montague, Center for Energy and Environmental Studies, Princeton
University, Princeton, NJ, has additional reports on the DuPont, Monsanto,
J.T. Baker, and Toms River Chemical sites.
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NJ Dept. of Environmental Protection
Page 6
Reference Documents
Copies of the following documents were provided to TRW:
• List of selected New Jersey “problem” landfills.
• Sample leachate analytical data and waste input data for the DuPont,
Monsanto, J.T. Baker, and Torns River Chemical sites.
• Background memo describing the design, construction, operation, and pro-
posed modifications to the LiPari landfill.
• Waste Identification and Definition document used in landfill permitting
activities.
• Copies of the latest state regulations governing sanitary landfill clo-
sure and post—closure and pollutant discharge elimination system regula-
tions.
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ASSESSMENT OF TECHNOLOGY FOR CONSTRUCTING AND
INSTALLING COVER AND BOTTOM LINER SYSTEMS
FOR HAZARDOUS WASTE FACILITIES
EPA Contract No. 68-02-3174; Work Assignment No. 109
INTERVIEW NO. C-6
MD Dept. of Health and : Robert M. Byer TRW: Sandra Quinlivan
Mental Hygiene, Office Reid J. Rosnick John Metzger
of Env. Programs 301-383-5736
Baltimore, MD
21 December 1982
Summary
• Most landfill facilities in the State of Maryland have clay liners con-
sisting of either reformed or in-situ clay. Good performance requires
minimizing emplacement of liquid wastes, removal of leachate, and proper
site selection to avoid contiguous sand lenses and to take advantage of
in-situ geology.
• QA/QC is important to ensure adequate performance of the liner. Compre-
hensive requirements of a OA/OC program should be specified to the con-
tractor covering every conceivable problem. The requirements actually
implemented might then be lessened according to the conditions that
develop during construction.
• Areas of research needs include evaluation of alternatives to landfills
and lonc’-term permeability of clay liners, includino leachate constituent
transport.
Background and Objectives
In 1982, the State of Maryland had only one operational hazardous waste
landfill, the BFI Solley Road facility in Glen Burnie, MD. This site, which
has a clay liner, was closed on 31 December 1982. A second nearby site at
Hawkins Point, near Baltimore City, will be expanded to include a new facility
which will be lined with a 30-mil PVC liner. The liner is to be installed in
January 1983.
The objectives of this interview were to obtain information on: (a) the
design, installation and/or performance of the liners at the existing and new
sites; (b) the general perspectives of the state on liner performance and
current liner regulations; and (c) additional references and data sources.
The perspectives expressed are based on the experience from the Solley Road
and Hawkins Point sites, as well as other facilities in the State of Maryland.
Principal Landfill Facilities Considered
• The Solley Road facility, which operated from the early 1960’s to 31
December 1982, was originally an uncontrolled landfill handling what was
thought to be solely municipal wastes. The landfill is located on a
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Page 2
total of 50 acres; however, the active portion permitted to accept
hazardous wastes contained approximately 8 acres. The in-situ clay in
which the facility is located ranges in thickness from approximately 20
feet in the northwestern portion of the landfill to 100 feet in the
eastern portion. This clay may be part of the Patapsco formation or
the silt-clay facies of the upper Potomac group. Not all sand lenses
encountered in the eastern portion of the landfill are water bearing.
The lenses that do contain water do not appear to be hydraulically con-
nected to the sands of the Patapsco formation. More study, however, is
needed in describing this aspect of the site geology. The landfill was
permitted to accept hazardous wastes in 1978 by means of an amendment
to its Refuse Disposal Permit. Input hazardous wastes are primarily
heavy metals—containing organic wastes from electroplating and iron and
steel industries, and various organic wastes. A leachate monitoring
well was installed in 1980; all collected leachate was removed via vacuum
truck to local Chem Clear, Inc., for treatment and disposal.
• The EPA became involved with the Solley Road Landfill as part of their
FIT (Field Investigation Team) program in the spring of 1981. Leachate
seeps were noted at that time; however, BFI pumped and packed those
seeps as they occurred. The FIT reported groundwater contamination
based only on one round of samples. Due to the minute quantities of
certain compounds encountered (ppb range), further study was in order.
At that time, the amount of data collected was insufficient to draw a
conclusion.
• BFI discovered construction problems with the original 6-well ground-
water monitoring system in the spring of 1982 which may have caused
improper sampling of the groundwater environment. A new 10—well system
was developed by the State and BFI and installed by the company in the
summer of 1982, capable of assessing site specific groundwater quality.
At this time, insufficient data has been collected from the new well
system to comment on groundwater quality.
• Closure of the landfill started on January 1. 1983, and will continue for
approximately 6 months. When the site is completely closed, a clay cap
will be emplaced with a soil cover to establish a proper vegetative
growth. Leachate seeps continue to be identified and analyzed.
• The Hawkins Point landfill is an 8-acre site having three cells. This
site is and has for sometime been very close to capacity, and a second
nearby site is being planned. One cell of the existing site is a mono-
fill of chrome ore tailings. The Hawkins Point landfill, including the
chrome ore refuse monofill, is lined with reformed in-situ clay, as well
as an 80 rnil. high density polyethylene liner. No sand lenses are within
at least three feet from the waste boundary. Leachate is collected via
a drainage pipe network and is pumped to a PVC-lined lagoon, then is
transported to Chem Clear, Inc. , for disposal . Several leaks which have
been observed have been attributed to the holding lagoon, which has been
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in place for about two years. The new site will be small at first
(approximately 30,000 cubic yard capacity) and will be operated by the
Maryland Environmental Services, which is an agency of the State.
Specific Experience and Perspectives on Liner Installation, Performance, and
QA/QC
• All permitted Controlled Hazardous Substances (CHS) disposal facilities
within the State of Maryland are sited in naturally occurring or recom-
pacted clay. Combinations of synthetic liners or recompacted clay
supplement in-situ clay when deemed necessary. No liquid wastes are
permitted to be disposed of in Maryland CHS disposal facilities. Leach-
ate is removed as it accumulates from approved leachate collection sys-
tems. Where synthetic liners were used, no compatibility testing was
performed. The liner manufacturer is relied upon to provide guidance in
the area of compatibility.
• The liner proposed for the new Hawkins Point site is reformed in-situ
clay and 80 mu, high density polyethylene. Welds will be made by over-
lapping the material and applying heat. Since welds should not be made
when the ambient temperature is less than 40°F, the January-February
weather can cause delays in installation. Because the subject Hawkins
Point facility is small, an alternative approach might involve construc-
ting a “mini-greenhouse” over the welding site to eliminate interruptions
due to cold weather.
• The state usually requests the manufacturer to be on-site to certify
proper seaming technique.
O QA/QC responsibilities are usually handled by a consultant hired by the
contractor. Any compromise of QA/QC integrity is minimized by proof of
performance of the contractor by the consultant whose records are main-
tained at the individual facility.
• All QA/QC requirements must be specified carefully in the construction
permit for a facility. Unless every conceivable contingency is addressed,
a less than satisfactory job is likely. Minor modifications lessening
the QA/QC requirements can later be made as appropriate during construc-
tion.
• The performance of clay liners is related to several factors: (a) emplace-
ment of liquid wastes - this should be minimized; direct disposal of
liquids is no longer permitted in Maryland; (b) leachate build—up - this
should also be kept to a minimum via collection and removal of leachate;
(c) occurrence of sand lenses among the clay deposits — these may not be
too troublesome unless they are hydraulically connected.
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Siting Factors
• All in—situ geology should be taken advantage of as much as possible.
This provides an additional margin of safety since the long—term inte-
grity of the liner is questionable.
• There exists a siting board in Maryland, and all new sites as well as
changes to existing ones must be considered by this group. In many cases,
the only likely approach to minimize both locational and political pro-
blems is to expand an existing facility. The political barriers can be
formidable.
Perspectives on Regulations and R&D Needs
• In certain areas of the regulations, it would be helpful to see specific
number requirements (e.g., “A site having hydrogeological conditions X
and V must utilize 7 feet of clay and a 20-mil thick liner”). However,
this too can cause problems if the established values are indefensible or
not applicable to the particular site under consideration. Overall,
regulations cannot 2ffectively communicate policy. Problems are highly
site-specific and should be treated as such to the extent possible. For
example, with monofils, monitoring is simplified since the type of waste
input to the fill is known. Not all requirements are therefore appropriate.
• Specific areas of R&D needs include the following:
- Alternatives to landfills. There seems to be an underlying, but in-
- correct, assumption that many waste materials can be handled only by
land disposal.
- Mechanisms of transport of leachate constituents.
- Long-term permeability of clay liners, including for inorganic wastes.
- Standardization/regulation of monitoring well construction and especial-
ly of sampling procedures. One sampling problem in particular has been
debated concerning sampling from wells, that is whether such samples
should be field filtered, lab filtered, or not filtered at all prior
to analysis. There is uncertainty concerning both the amount of con-
stituents of the groundwater that sorb to silt and clay (particularly
metals in the ppb range), and the public health and broader environ-
mental significance of this. Proponents of field or lab filtering
generally assume that the water’s suitability as a potable source
should be of principal interest, and that no water of high turbidity
would thereby be used without fitration.
• Regulations can and do communicate policy. They are/should be based on
best available technology. Site specific problems can be treated to a
large extent within the framework of the regulations. Some general
questions are suitable as research topics, and the results of research
can be effectively applied. An example is identification of materials
that degrade the liner.
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Additional Suggested Contacts
The following or9anizations/fndividuals should be contacted for further
I niormation:
• Catherine Hodgkins; EPA/Philadelphia; for leachate seep analytical data
for the BFI Solley Road landfill.
• Law Engineering, Inc.; Baltimore, MD; for additional hydrological and
geological data for the BFI Solley Road landfill.
• Mr. Craig Fadam; Chem Clear, Inc.; for leachate analytical data for the
BFI Solley Road and Hawkins Point sites.
• EPA/FIT damage case files on the BFI Solley Road facility.
Reference Documents
The following documents were provided to TRW:
• Selected excerpts from “Field Investigations of Uncontrolled Hazardous
Waste Sites”, FIT Project, TDD No. F3-8007-48, EPA No. MD-6, 1981.
• Report by Hardin-Knight Associates, Inc., Pasadena, MD, on results of
permeability testing of Hawkins Point chrome ore leachate with clay soils.
• Copies of State of Maryland Title 10, Subtitle 51, hazardous waste regu-
lations (12 December 1980), and addendum (8 January 1982), and proposed
regulations (effective 30 January 1983).
• Extensive waste input data, leachate, and groundwater analytical data
available.
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ASSESSMENT OF TECHNOLOGY FOR CONSTRUCTING AND
INSTALLING COVER AND BOTTOM LINER SYSTEMS
FOR HAZARDOUS WASTE FACILITIES
EPA Contract No. 68-02-3174; Work Assignment No. 109
INTERVIEW NO. C-7
WI Department of Natural : Peter Kmet TRW: Sandra Quinlivan
Resources, Bureau of Solid 608-266-8804
Waste Management
Madison, WI
14 January 1983
Summary
• Most facilities in the State of Wisconsin use a liner system consisting
of four to five feet of recompacted local clay, covered with 12 inches
of sand and/or gravel, and containing the leachate collection system.
• A thickness of 4 to 5 feet reduces the chances for liner damage during
installation.
• The state is extremely pleased with the performance of clay as a liner
material, as evidenced by results of groundwater monitoring at many
sites. Its concepts of liner and landfill design, construction, and
operation have been proven effective and are currently being documented
and disseminated.
• In addition to proven performance of clay liners, the preference for clay
stems from its natural abundance and ready accessibility for landfill
lining in Wisconsin.
• The type and thickness of clay are the most important factors affecting
the performance of a clay liner.
• The existing state regulations require more emphasis on use of clay (as
opposed to synthetic liners) and on siting factors for new facilities.
• There is a great need for R&D in areas of leachate prediction, compati-
bility testing, and landfill stabilization. In the realm of leachate
prediction, exchange of information among those having “real world”
leachate data for use in model testing is needed.
Background and Objective
The Bureau of Solid Waste Management, Land Disposal and Residuals Manage-
ment Section, has responsibility for permitting and inspecting municipal and
industrial landfills in the State of Wisconsin. There are approximately 1100
landfills in the state. Most of these sites consist of small unengineered
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WI Dept. of Natural Resources
Bureau of Solid Waste Management
Page 2
town dumps. However, it is estimated some 250 sites operate in accordance
with engineering plans of varying detail and complexity. One design con-
cept employed at 7 of the larger municipal solid waste landfills consists
of the use of a reconipacted clay liner and full leachate collection system.
Several new sites are also currently being proposed utilizing this concept.
The objective of this telephone interview was to obtain information on the
perspectives of the state on the use of clay and synthetic liners. Specific
topics discussed included: (a) considerations in design, construction, and
installation of liners in typical facilities; (b) assessment of liner per-
formance; (c) perspectives on current regulations and research needs; and
(d) other references and data sources.
Landfill Design and Operation Considerations
• A summary of the design and operating characteristics of seven major,
recently constructed landfills is presented in Table 1. As indicated
in the table, all of the sites are clay-lined.
• Clay is highly preferred over synthetic liners in Wisconsin because of
its availability throughout the state and its excellent overall per-
formance. Most of the state’s clay-lined landfills have clay deposits
on the same or nearby properties. The Brown County Landfill , the City
of Janesville Landfill, and the Waste Management, Inc. Landfill are
situated in old gravel pits having clay overburden which was stripped
off and later recompacted for use as the liner material. For the re-
maining sites listed in Table 1, the furthest that clay had to be hauled
was 20 miles (for the Portage County Landfill).
• All sites have a sand and/or gravel blanket over the clay liner to
facilitate drainage of leachate. Leachate is removed via a series of
perforated pipes and directed to an external storage tank where it can
be periodically removed for treatment. The goal of this system is to
minimize the build-up of a leachate head on the liner.
• Although the state has a high degree of confidence in the use of clay
liners, each site is carefully evaluated to insure there is minimal
risk of groundwater impacts. Factors considered include the site’s
geology (soils, bedrock) and hydrogeology (depth to gel H20 and direc-
tion of flow, existing water quality, location of site in flow system
(recharge vs. discharge zone)), potential impacts on surface water bodies
and existing or potential groundwater users. Each site must also identi-
fy a suitable clay source and method of leachate treatment.
• All of the landfills practice co-disposal of various industrial wastes
such as boiler ash, manufacturing wastes, pulp and paper sludges, foundry
wastes, and household chemical wastes with municipal trash.
4-194
-------
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TABLE 1. DESIGN AND OPERATING CHARACTERISTICS OF SEVEN MAJOR WISCONSIN LANDFILLS
-I
‘.0
U,
Landfill
Start-
Up
Date
Capacity
(in cubic
yards)
Liner System
Leachate Collection
System
Miscellaneous
Brown County,
1976
6,000,000
4 ft of recompacted
System of perforated
Site is currently at 20t of
Green Bay, WI
clay, with 5 ft under
the leachate collec—
tion lines, plus 12
Inches of sand and
gravel on top of the
clay.
PBS pipes (SDR 13, 6”
ID) leaôing to holding
tank; 4.1,000 gallons/day
of leachate sent to
local wastewater treat-
ment plant via vacuum
truck.
capacity, the following quan-
tities of leachate were
collected from 1977 to 1982.
29.900 gal/S acres (1977),
224,550 gal/l0.5 acres (1978);
505,950 gal/17.0 acres (1979),
257,225 gal/17.0 acres (1980),
376,801 gal/2L0 acres (1981);
325,986 gal/24.0 acres (Jan. -
June 1982).
Cost - $7.35/ton.
Seven Mile
1979
1,200,000
Same as for Brown
PVC pipes (Schedule 40,
Site has better overall design
Landfill,
County landfill,
4 & 6” ID) leading to
than Brown County site in terms
Eau Claire, WI
except 12 inch
sand blanket
holding tank; leachate
sent to local wastewater
treatment plant via
vacuum truck.
of sloping of the base and
certain other features. There
are several leak detection suc-
tion lysimeters underneath the
liner at this site.
Cost - $18.75/ton.
City of
1979
700.000
5 ft of recompacted
PVC pipes (SDR 35. 4 &
Site has experienced some sus-
Janesvi l le
Landfill,
Janesville, WI
clay under entire
site, plus 6 inches
of sand and gravel
on top of the clay.
8” ID) leading to hold-
ing tank. Leachate
currently taken to
wastewater treatment
plant via vacuum truck,
but a direct hook-up to
the plant Is being con-
sidered.
pected plugging of leachate
collection lines by silt.
Recent cleanout of the lines
appears to have resolved this
problem. The following quanti-
ties of leachate were collected:
0 gal/5.5 acres (1979);
555 gal/lO.0 acres (1980),
29,200 gal/14.0 acres (1981);
13,000 gal/14.0 acres (Jan -May
1982). Cost - $12.00/ton.
Cost - $12.00/ton.
(Continued)
-------
Waste Management 1980
Inc. Landfill,
Muskega, WI
Marathon County
Landfifl, near
Wausau, WI
Sauk County
Landfill, near
Madison, WI
1,300,000 Same as for Brown
County landfill.
1980 1,500,000 Same as for Brown
County landffll
except 12 inch
sand blanket.
Same as for Brown
County landfill.
1982 1,200.000 Same as for Brown
County landfill,
except 6 Inch
select gravel plus
6 inch sand blanket
on clay.
Same as for Seven Mile
landfill, except
Schedule 40 5 60 PVC.
4” ID.
Leachate directed to a
clay-lined storage basin
via SDR 35, 8” ID PVC
pipes In addition, a
layer of 20-nnl PVC
sheets connected to a
riser was installed un-
derneath a small portion
of the clay layer to
menitor liner leakage.
Same as for Seven Mile
landfill, except 6’ ID.
Schedule 80 PVC pipes.
In addition, a 30-mil PVC
liner and riser system
similar to that at the
Marathon County site was
recently installed.
Same as for Portage
County landfill.
No cost data available.
The following quantities of
leachate were collected:
267,224 gal/4.5 acres (1981);
186,415 gal/7.0 acres (Jan. -
June 1982).
Cost - $14.00/ton.
TABLE 1. (Continued)
Landfill Start-
Capacity Liner System Leachate
Collection Miscellaneous
Up
Date
(in cubic
yards)
System
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Portage County 1982
Landfill, near
Portage, WI
Cost — $15.90/ton.
Cost (estimated) - $14.81/ton.
-------
Interview No. C-7
WI Dept. of Natural Resources
Bureau of Solid Waste Management
Page 5
• At the Marathon County, Portage County, and Sauk County landfills, a
30-mu PVC sheet connected to a riser has been or is currently being
installed under a small portion of the clay liner at each site to
monitor leakage from the clay liner. There are no results as yet from
these monitoring systems.
Liner Construction, Installation, and Performance
• Construction activities typically involve preparation of subgrade, ex-
tensive staking and surveying to insure proper thickness and slope of
liner, compaction of clay in thin lifts, testing of clay as it is
placed, installation of leachate collection system, sand blanket place-
ment, construction of drainage structures and site access, and installa-
tion of monitoring devices.
• On-site inspections are the responsibility of the consulting firm, which
must provide the state with “as-builts ’ which certify that the site was
constructed according to state-approved plans and which document any de-
viations from these plans. State personnel will periodically go out and
do quick visual inspections of the landfill grades and general construc-
tion procedures. The state would be much more likely to become more
heavily involved in the inspections if only a one-foot thick clay liner
were being installed instead of a four- or five—foot thick liner. Since
they are convinced that their four- to five-foot design requirement is
adequate, as evidenced by the fact that all monitored sites are working
effectively (i.e., that no changes in groundwater quality have been
observed at any of the sites), there are less stringent state inspection
requirements.
• Prior to construction of the liner, a sample of clay from the clay source
is subjected to an extensive laboratory physical testing which includes
the following measurements:
— Proctor and/or modified Proctor density (a minimum compaction spec
of 90 percent mod. Proctor is usually specified).
- Permeability at different densities (a maximum permeability of 1 x
iü cm/sec is required).
- Grain size. The clay and silt fraction of the sample must be greater
than 50 percent passing a #200 sieve without excessive stones or
gravel.
- Atterburg limits. A liquid limit of 30 and a plasticity index of 15
or better, to insure high quality, readily compacted clay.
- Attenuation characteristics. The candidate clay must be at least 25
percent clay.
• Cation exchange tests are felt to be desirable but are not yet mandated
(see later comment on costs).
4-197
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Interview No. C-7
WI Dept. of Natural Resources
Bureau of Solid Waste Management
Page 6
• High-shrinkage bentonite clays are considered inferior to other types
of naturally occurring Wisconsin clays.
• No compatibility testing between leachate and clay is currently re-
quired by the state, but they are seriously considering it. Up until
now, there wasn’t thought to be any problem, based on the waste input
types accepted. However, recent research sponsored by EPA has raised
this as a concern. Hence, it likely will be required at some of the
newer sites, or expansions of existing facilities.
• The state is extremely pleased with the performance of the four- to
five-foot thick clay liners, based on no changes in groundwater quality
which have been observed in any of the sites listed in Table 1. All
sites have extensive groundwater monitoring systems for which samples
are routinely analyzed for pH, conductivity, alkalinity, COD, total
hardness, iron, and chloride. There had been a strong trend toward the
use of clay in the state as far back as the late 1960’s and early 1970’s.
The Brown County landfill, which was constructed in 1976, was the first
site that actually was constructed utilizing a well documented recom—
pacted clay liner. The state is also quite pleased with its overall
leachate collection and general landfill design concepts, and is at the
point of documenting these and disseminating them to other agencies!
organizations in other parts of the country.
• The most important factors affecting the performance of the clay liner
are the type and thickness of the clay itself. (A good quality clay
will facilitate construction and provide an effective barrier to leach-
-ate migration.) Other factors which may affect performance (e.g., sub—
grade preparation, recompaction techniques, equipment handling, etc.)
are also important but are really secondary. For example, at one of
the landfills, a careless driver crossed the liner and rutted it up;
However, because the layer of clay was so thick, it would not have
affected the liner’s effectiveness if left uncorrected.
• Other considerations in proper site operation are adequate design and
installation of leachate collection lines with respect to the liner, and
of other equipment. There have been a few incidents in Wisconsin land-
fills involving collection system failures. For example, at the Seven
Mile landfill near Eau Claire, a leachate collection line was crushed
during filling. Department staff feel this could have been avoided if
the line had been installed in a trench in the liner rather than
directly on top of the liner (providing little lateral support). This
has been required at other sites with no reported failures to date.
At this same site, a leachate holding tank broke due to improper design.
• Regarding closure requirements, clay-lined landfills are also required
to be clay-capped to minimize leachate generation. Closure is generally
performed in phases; that is, the landfill is built, filled, and aban-
doned in a phased manner in modules. The specifications for the clay
4-198
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Interview No. C-7
WI Dept. of Natural Resources
Bureau of Solid Waste Management
Page 7
cap are less stringent than those for the liner, The Seven Mile land-
fill is currently experimenting with use of a paper mill sludge cap
for closure of filled cells. All sites are required by state statute
to set aside monies for the closure and long term care for at least
20 years. LTC includes land surface care, monitoring and leachate re-
moval and treatment. A special state fund has been established to
care for sites after the 20 year owner responsibility.
Perspectives on Regulations
• The current federal regulations emphasize synthetic liners rather than
clay liners. Wisconsin doesn’t have a great deal of experience with
synthetic liners as yet, but in general they would like to see more
extensive use made of clay systems which are performing adequately
there.
• The federal regulations currently do not adequately consider siting
factors, especially the hydrological, geological, and other physical
characteristics of new sites. There should be more concern for the risk
to aquifers in the event of liner failures.
• Approval for new facilities have been handled in Wisconsin on a case-
by-case basis. However, now that the state is becoming more confident
of the performance of clay liners and of their landfill design criteria
in general, they are beginning to document their design criteria and
are considering making them mandatory throughout the state.
Research Needs
R&D efforts would be worthwhile in the following areas:
• Liner compatibility testing. Studies should be conducted either by the
applicants or by research institutions on various liner materials.
• Materials (e.g., piping filter fabrics, tanks) compatibility testing.
Research is needed to determine the compatibility of PVC, ABS. and other
materials used in leachate collection lines. There have been a few in-
cidents at Wisconsin sites involving failures of collection lines and
holding tanks. Although these incidents were thought to be due to
mechanical problems, the area of compatibility still needs to be ex-
plored. Also, methods for detecting leaks below liners need to be
developed.
• Leachate prediction, both qualitative and quantitative. Several models
have been used in Wisconsin for leachate plume prediction and landfill
design. The state relies primarily on the U.S. EPA water balance method
(1975) for predicting the quantity and timing of leachate generation
(see internal staff memorandum). To determine liner efficiency and
4-199
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Interview No. C-7
WI Dept. of Natural Resources
Bureau of Solid Waste Management
Page 8
evaluate design options, Department staff use a variation of a model
developed by Dr. Wong (Water Resources Research, Vol. 13, No. 2,
April 1977). The model is discussed in a paper presented by Kniet,
Quinn, and Slavik (see References section). For industrial wastes,
various laboratory leaching tests have been used in an attempt to pre-
dict leachate quality. These models and methods need to be verified
using “real world” data. There is also a need for a better mechanism
of exchange of information among various agencies having real leachate
generation data.
• Landfill stabilization. The actual length of time required for stabi-
lization needs to be determined as a function of waste types and fill
configurations. Laboratory studies using lysimeters need to be con-
firmed by “real world” conditions.
Additional Suggested Contacts
The following individuals have extensive experience/data in the indi-
cated areas:
• Mr. Dan Kolberg; Warzyn Engineering Co.; Madison, WI; (608-257-4848);
for details of landfill and liner design and installation. (Firm has
experience with several sites.)
• Mr. Clarence Stoffel; Owen—Airs & Associates; Eau Claire, WI;
(715-834-3161); for information on synthetic liners. (Also design firm
for Eau Claire Site.)
• Dr. Robert Ham; University of Wisconsin; Madison, WI; for landfill and
liner design and performance.
References Provided
• P. Kmet and P.M. McGinley. “Chemical Characteristics of Leachate from
Municipal Solid Waste Landfills in Wisconsin”, presented at Fifth
Annual Madison Conference of Applied Research and Practice on Municipal
and Industrial Waste, Sept. 22-24, 1982, University of Wisconsin Exten-
sion, Madison, WI.
• P. Kmet, K. Quinn, and C. Slavik. “Analysis of Design Parameters Affec-
ting the Collection Efficiency of Clay Lined Landfills”, 1981.
• P. Kmet. “EPA’s 1975 Water Balance Method - Its Use & Limitations”,
Internal Staff Memorandum, 1982.
4-200
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4.4 INTERVIEW REPORTS WITH RESEARCHERS IN ACADEMIC AND RESEARCH ORGANIZATIONS
D-1. Southwest Research Institute
D-2. University of Texas
D-3. Texas A&M University
D-4. Matrecon, Inc.
D-5. Denver Research Institute
D-6. U.S: Army Corps of Engineers, Waterways Experiment Station
D-7. U.S. Bureau of Reclamation
D-8. Illinois State Geological Survey
4-201
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ASSESSMENT OF TECHNOLOGY FOR CONSTRUCTING AND
INSTALLING COVER AND BOTTOM LINER SYSTEMS
FOR HAZARDOUS WASTE FACILITIES
EPA Contract No. 68-02-3174; Work Assignment No. 109
INTERVIEW NO. D-1
Southwest Research Institute: David Shultz TRW: Michael D. Powers
San Antonio, TX 512-684—5111 Michael 1. Haro
13 December 1982
Summary
• A non-destructive method to detect and locate leaks in synthetic liners
is being tested. The method can be applied to existing as well as new
surface impoundments or landfills, and can be used for monitoring or
liner QA/QC.
• There is no way to 100 percent guarantee that a liner will not fail;
there are too many things that can go wrong.
• All possible sources of problems should be explored during the design
and/or construction phases, and contingency plans made for correcting
problems as they occur. Landfills and surface impoundments should be
designed so that the liner can be reached for repairs.
Background and Objectives
Shultz’s research has centered on oroblens of liner installation and
performance. His most recent work has focused on an electrical resistivity
method that will allow the detection and location of leaks from synthetic
liners. Objectives of this interview were to obtain information on: (a)
background, results, conclusions, and recommendations from studies to date;
(b) Dr. Shultz’s perspectives on liner installation and performance; (c)
planned research efforts; and (d) additional references and data sources to
be contacted.
Prior and Current Research
• Shultz has completed an EPA-funded s ud ’, “Case Studies for Lined
Impoundmentsu (Grant No. R806645010); a draft report has been submitted
and is currently undergoing review. A project to conduct follow-up
studies of the sites visited has not been funded.
• Shultz and his colleaques at SWRI are currently testino an electrical
resistivity method designed to detect and locate leaks in synthetic
liners. Preliminary computer and small-scale physical modelling are
complete; SWRI is now in the process of building a small (one acre) sur-
face impoundment for field-testing the method.
4-202
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Interview No. D-l
Southwest Research Institute
Page 2
• Dr. Shultz expects the method to be applicable for both surface impound-
rnents and landfills, and can be used at existing sites as well as being
built-in at new facilities. It is expected that the method will enable
leaks to be discovered before groundwater contamination occurs; the only
other methods available at present (i.e., groundwater monitoring) will
not detect leakage until after a contaminant plume has travelled to the
nearest down—gradient monitoring well at a concentration that can be de-
tected. The method can be used as a QA/QC leak test; it is more sensi-
tive than water balance testing because no estimates of evaporation need
to be made, and even very small flows will be detectable. The method
may also be applicable to detecting gas leaks in landfill caps. The
method requires a conducting medium such as water or soil in the impound-
ment that is separated from the underlying soil by a high resistance
liner material such as synthetics; the resistance of clay is too low for
the method to work. Current is injected by means of electrodes located
inside the impoundment, and at a distance well outside. The resulting
electrical field is analyzed by measuring the voltage at various points
across closely spaced electrodes. In the absence of a leak, current
flows only through soil at the buried edge of the liner. Current flows
through the liner only where a leak is present; the resulting current
produces an anomaly in the field which can be located with fairly high
accuracy.
• Other projects, either in progress or forthcoming, include:
- A study of ways to retrofit existing leaky fluid impoundments without
taking them out of service. One of the proposed methods involves
pulling a flexible membrane across the surface, then pumping the fluid
onto the top of the membrane: a “pump-over” technique. The other in-
volves pulling a membrane along the bottom contour of the impoundment:
a “pull-through” technique. Both techniques are seen as temporary
“quick-fixes” of leaking facilities that are to be drained and retired
within a short period of time.
— Additional remedial action studies involve repairs to existing facili-
ties, using grout or patching with synthetic sheeting.
- A monitoring system will be tested using electrical resistivity
readings made from boreholes spaced around the perimeter of the small
test impoundment being installed at SWRI. Anomalies in the electrical
field caused by fluids flowing through leaks can be detected and then
located by triangulation.
- One corner of the SWRI test impoundment will be used by EarthTech to
demonstrate the feasibility of using acoustic emission and time-domain
reflectrometry techniques for leak detection.
- An RFP has been sent out by EPA for a study on the success or failure
of liners. Unfortunately, the major source of such data lies in the
files of the installers and manufacturers; such data are generally not
available, but could be pried loose by tying permits to the release of
the data. Even with such data, we may never be able to determine for
sure the cause of a liner failure.
4-203
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Interview No. D—l
Southwest Research Institute
Page 3
Perspectives on Liner Installation and Performance
• There is no way to 100 percent guarantee that a liner will not fail;
there are too many things that can go wrong (i.e., ground shifting, poor
installation, heavy equipment damage, damage from wildlife). Synthetic
liner sheeting has the potential to contain fluids, but most realize the
limitations; it is not possible to just install a liner and then forget
it. However, if a facility has been properly designed, installed, oper-
ated, and maintained, if it is properly monitored, and if the operation
has adequate contingency plans for handling problems as they occur, it
is possible to be reasonably confident about the overall performance of
the liner. Several possible ways to alleviate problems are:
- Design landfills and surface impoundments so that the liner can be
reached, if necessary, for repair. Multi-cell facilities, spread
over larger areas so that they are not as deep, would help in this
regard; landfills 150 feet deep or surface impoundments 80 feet deep
would not be amenable to liner repair.
- All possible sources of problems should be explored during the design
and construction phases, when potential leaks can be sealed easily.
- Better QA/QC during construction and installation.
- Performance monitoring of the liner system.
• Installation QA/QC requirements should be developed by EPA with industry
participation. Regulations should contain guidelines for the content of
the QA/QC effort; third party installation QA should be required, in
much the same way as required by the NRC.
• Dr. Shultz says that the owners of facilities are ultimately responsible
for leachate damages, not the liner installers; the owners ‘should be
willing to take the ball and run with it”, since they are the ones like-
ly to be sued in the event of a failure. Part of the problem is deciding
what an owner should be required to do. Many times, owners are ignorant
of what is actually happening, relying instead on the consulting engineer;
often, the best techniques for construction, installation, and operation
are not being communicated y EPA, consultants, or contractors. Another
part of the problem is the chain of responsibility; in many cases, this
is long and complicated, with the owner far removed from the actual liner
installation contractor. In such instances, an owner may hire the design
engineer who subcontracts to the general construction contractor, who in
turn hires the dirt-work contractor, who finally hires the installation
contractor, with the type and manufacturer of the liner possibly being
chosen at any of these levels.
• “If the [ electrical resistivity] method does what we want it to, it should
be put into the regulations”. However, the method should not be required
by regulations without a qualification regarding its applicability. In—
stead, a performance standard is probably more appropriate.
4-204
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interview No. D-1
Southwest Research Institute
Page 4
• Where phased expansion of a landfill is planned, an area along the edge
of the liner in the existing disposal area should be protected from
contact with the wastes. This will prevent the deterioration of the
surface of the sheet, and will facilitate bonding of the old and new
liner sheets.
Documents Cited
The following documents were cited by Shultz; no new documents were pro-
vided.
• Shultz, David W. Case Studies for Lined Impoundments (Draft). U.S.
Environmental Protection Agency, Cincinnati, Ohio. 58 pp.
• Shultz, D.W. and M.P. Milkas, Jr. Procedures for Installing Liner Sys-
tems. In: Land Disposal of Hazardous Waste, Proceedings of the Eighth
Annual Symposium. EPA-600/9-82-002, pp. 224-238.
• Shultz, D.W, and M.P. Milkas, Jr. Installation Practices for Liners. In:
Land Disposal , Hazardous Waste Proceedings of the Seventh Annual Research
Symposium. EPA-600/9-81-002b, pp. 157-166.
• Shultz, D.W. and M.P. Milkas, Jr. Assessment of Liner Installation Pro-
cedures. In: Disposal of Hazardous Waste, Proceedings of 6th Annual Re-
search Symposium. EPA-600/9-80-OlO, pp. 135-146.
• Peters, W.R.; D.W. Shultz; and B.M. Duff. Electrical Resistivity Tech-
niques for Locating Liner Leaks. In: Land Disposal of Hazardous Waste,
Proceedings of the ighth Annual Symposium. EPA-600/9—82-002, pp. 250-
260.
4-205
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ASSESSMENT OF TECHNOLOGY FOR CONSTRUCTING AND
INSTALLING COVER AND BOTTOM LINER SYSTEMS
FOR HAZARDOUS WASTE FACILITIES
EPA Contract No. 68-02-3174; Work Assignment No. 109
INTERVIEW NO. D-2
University of Texas: Dr. David E. Daniel TRW: Michael D. Powers
Austin, TX 512-471-1555 Michael T. Haro
13 December 1982
Summary
• Actual permeability of an installed clay liner may be as much as 2 or 3
orders of magnitude greater than that predicted by laboratory testing
due to
- Differences in field and lab permeability tests
-- differences in compactive effort;
-- small laboratory sample size not representative of the overall
liner;
-- lab samples are uniformly moistened prior to compaction whereas
soil in the field is not.
- Desiccation of the clay liner between the end of construction and the
beginning of operation.
• All liners leak; even under the best of conditions, the requirement for
an impermeable liner cannot be satisfied.
• Field testing of clay liner permeability and construction techniques
aimed at improving the quality of finished products are recommended.
Background and Objectives
Dr. Daniel’s main area of research centers around the flow of fluids
through fine grained soils such as clay. Recent work has focused on the
problems of fluid leakage through compacted clay liners. The objectives of
this interview were to obtain information on: (a) background, results,
conclusions, and recommendations of Dr. Daniel’s studies to date; (b) Dr.
Daniel’s perspectives on liner installation and performance; (c) Dr. Daniel’s
current and planned research effort; and (d) additional references and data
sources to be contacted.
Background and Recommendations Based on Case Studies
Dr. Daniel has analyzed data for several leaking clay liners in Texas.
The work has resulted in the development of specific conclusions and recom-
mendations for soil permeability testing and clay liner construction. The
case studies include work with two leaking reflecting pools in San Marcos, TX,
4-206
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Interview No. D-2
University of Texas
Page 2
in which IJr. Daniel was involved as a consultant as well as in analysis of
data obtained from the Texas Department of Water Resources and from other
sources on a number of leaking ponds in Texas.
• Case Studies:
1) Reflecting pools in San Marcos, TX. In 1980, Dr. Daniel was contacted by
a consulting engineer to assist in resolving problems with two reflecting
pools in San Marcos, TX. The natural soil at the site consisted of 5 ft.
of clay overlying gravel deposits. However, in order to achieve the de-
sired 5-foot depth, the ponds had to be excavated through the clay into
the underlying gravel ; the excavated clay was to be stockpiled and then
reconipacted to form a liner. Laboratory tests of the clay compacted in-
dicated permeabilities in the 10-7 to 10-10 cm sec 1 range, with 10-8
being a typical value. Field density tests of the as-built liners indi-
cated compaction to about “optimum”, but with a moisture content about 2%
below optimum. When an attempt was made to fill the ponds, it was found
that the ponds would not hold the design depth of 4 ft. of water; leakage
exceeded pumped in-flow at a depth of 12 inches. The ponds were subse-
quently allowed to drain; using the fall rate, evaporation rate, and prior
pump rate, permeability was estimated to be 2 x 10-5 cm sec- 1 . An actual
field permeability test was run with similar results. The liner was
removed, recompacted wet of optimum, with filling commencing immediately
upon completion, so that no desiccation of the clay was allowed. Field
permeability tests had marginally lower results (about 10-6), which did
allow the ponds to be filled to their design depth. Laboratory permeabi-
lity tests of clay compacted much drier than optimum still had results
close to 10—7 cm sec-’, as did tests of an “undisturbed” sample.
Data and experience with the reflecting pools case study thus indicated
that a larger sample size resulted in much higher measured permeabilities.
Testing of large undisturbed samples resulted in permeabilities in the
2 x l0- to 2 x 10-6 range, whereas recompaction of smaller samples of
the same clay has results two to three orders of magnitude lower. This
effect may be due to the presence of large, surface-wet clods of clay;
moisture does not have adequate time to penetrate to the dry and cracked
interior portions of the clod.
2) Power plant cooling pond in Texas. At a Texas power plant cooling pond
with a bentonite-soil admixture, monitoring wells indicated a groundwater
mound beneath the site. Using very conservative assumptions (e.g., using
the volume of water currently in the mound as the total discharge),
effective permeability was estimated to be about 10-6 cm sec 1 . Double-
ring field pernieameter tests had similar results. Laboratory studies by
the power company’s geotechnical consultant showed much lower permeability.
3) Brine pond near Corpus Christi. This pond leaked badly. Using conserva-
tive assum2tions similar to those above, permeability was estimated to be
in the l0 to 10—6 cm/secl range.
4-207
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Interview No. 0-2
University of Texas
Page 3
4) Cooling pond in Northern Mexico. Estimates of effective field permeabi-
lity for this pond, which was also leaking, were more than 10 times the
results of field tests when the pond opened, and laboratory values.
• Conclusions from the case studies:
1) Desiccation of the clay liner between the completion of construction and
the commencement of operation allows the clay to become severely cracked,
resulting in much higher effective permeabilities.
2) A non—uniform moisture distribution in the soil results in clods with
wet surfaces, but dry, cracked interiors that allow rapid leachate migra-
tion. This problem is in part due to: (a) inadequate break-up of large
clods during compation; (b) large water trucks do not distribute water
evenly; and (c) inadequate time is allowed for the water to penetrate
the soil.
3) Allowing compaction dry of optimum to less than 95% of Proctor density
results in a high permeability clay liner. This is caused in part by the
optimum water content shifting a few percent “wetter” when less energy is
used in compacting soil; soil compacted “dry” of optimum can be several
orders of magnitude more permeable than soil compacted at or greater than
optimum.
4) Small roots and other homogeneities in the clay adversely affect permea—
b i 1 i ty.
• Recommendations based on results from case studies:
1) Clay liners should usually be compacted wet of optimum, with final den-
sity at or areater than the Proctor maximum measured in the laboratory.
2) Dirt-work construction specifications should specify smaller clods; a
3—inch maximum size would be ideal, but 6 inches may be all that can be
achieved using current equipment and techniques.
3) Achieve uniform moisture distribution, for examole, by premoistening clay
so that it is thoroughly hydrated.
4) Protect the clay liner from desiccation from the completion of dirt-work
to the start of operation. Examples of ways to do this are: (a) spray
on a thin coating of asphalt; (b) use of thin membrane of polyethylene
(or other synthetic); (c) use of 1 to 2 feet of soil; and (d) put water
on the liner immediately.
Perspectives on Liner Installation and Performance
• All liners leak, even under the best of conditions. Based on the results
from the case studies presented above, it is not possible to make an
impermeable liner; requiring prevention of seepage through liner for 30
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years may be very difficult. Actual seepage velocity through liner is very
much faster than that predicted by Darcy’s law, based on total porosity:
v = ki/n
where v = velocity
k = permeability
I = hydraulic gradient, i H/M
n = porosity
In clays, part of the void space is filled by cations and water molecules
adsorbed along the clay layer surfaces. In addition, many pores have no
outlets; they are, in effect, ‘dead ends”. These two factors result in
an “effective” porosity much lower than the total void space expected.
Dr. Keros Cartwright of the Illinois State Geological Survey has found
that effective porosity of clay is about 1 to 3% (as opposed to 30-40%
total porosity). Thus, actual velocity of a fluid through the clay is
much faster than might be expected based on apparent porosity.
• EPA should include installation QA/QC requirements in new regulations.
These requirements should include:
- Measurements of dry unit weight and moisture content of the compacted
soil.
- Field permeability tests; laboratory tests are often useless. Possible
ways of field testing the liners are: (a) during the design phase, build
a test liner and test over a relatively large area for 2—4 weeks; and
(b) test the first lift of fill over a relatively large area.
- A QA/QC inspector should be on—site (most dirt-work contractors are
used to having inspectors on-site).
- Desiccation of the clay should be minimized.
— EPA should also require data on seepage after operation begins, to
allow an estimation on “back-calculation” of actual permeability.
- The current lack of a standard method for determining permeability
in the field must be addressed. Dr. Daniel is currently working with
ASTM Committee D-18.20 on the development of such a test, but expects
that it will be some time before a consensus is reached.
• Licensing of installers will not ensure quality work. Almost anyone can
be an installer now, and would be able to continue after a licensing re-
quirement took effect. Requirement for a QA/QC inspection by a third
party is preferable to licensing of installers. It may be difficult to
get really qua 1 ified QA inspectors, but a training system or manual would
help.
• We know almost nothing about the long-term performance of liners. The
best source 0 f data regarding performance of clay liners is earth dams;
they have been around a long time, and with a few notable exceptions,
they have performed relatively well.
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On-going and Planned Research
Research work currently being carried out or planned by Dr. Daniel in-
cludes the following:
• EPA-sponsored project. This research centers on the permeability of clay
liners and includes:
- Comparison of results from field and laboratory permeability tests.
- Testing of a flexible wall perneameter apparatus. This design should
correct a problem seen in fixed wall permeameters wherein the clay
“liner” can separate from the solid walls, allowing a seepage path
around the clay.
- Compatibility of compacted clay liners with wastes using concentrated
organic chemicals and hydraulic gradients of 2, 10, 50, 300, and 1000.
• CMA-sponsored study. This study will expand upon K.W. Brown’s basic clay
permeability work by changing some variables including use of several
concentrations of the organic chemicals, and real leachates (to be sup-
plied by CMA).
• NSF study. A two-year project for NSF will evaluate clay liners for
hazardous waste sites. The study will seek to address the following:
(a) why is the permeability of clay so hard to predict; (b) is desicca-
tion a critical factor; and (c) is clay clod size a critical factor?
• Use of drilling mud to produce sand-bentonite liner. A waste disposal
study for Texas Petroleum Resources Comission to determine if bentonite
from liquid drilling mud can migrate into sand, forming a sand-bentonite
liner.
Reference Documents
• Copies of the following reference documents were provided to TRW by Dr.
Daniel:
- Daniel, D.E. Predicting Hydraulic Conductivity of Clay Liners.
Undated preprint.
- Daniel, D.E. Problems in Predicting the Permeability of Compacted
Clay Liners. In: Symposium on Uranium Mill Tailings Management;
Fort Collins, CO; October 26-27, 1981; Colorado State University.
• In addition, Kirk Brown of Texas A&M referred TRW to the following papers
by Dr. Daniel and his colleagues at UT, in Permeability and Groundwater
Contaminant Transport, ASTM Publication STP 746, 1981:
- Olson, R.E. and D.E. Daniel. Measurement of the Hydraulic Conduc-
tivity of Fine-grained Soils.
- Hamilton, J.M.; D.E. Daniel; and R.E. Olson. Measurement of Hydraulic
Conductivity of Partially Saturated Soils.
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ASSESSMENT OF TEC 1NOLOGV FUR CONSTRUCTING AND
INSTALLING COVER AND BOTTOM LINER SYSTEMS
FOR HAZARDOUS WASTE FACILITIES
EPA Contract No. 68-02—3174; Work Assignment No. 109
INTERVIEW NO. D-3
Texas A&M University: Dr. Kirk W. Brown TRW: Michael T. Haro
College Station, TX 713-845-5286 Michael D. Powers
14 December 1982
Summary
• Clay may be acceptable as a liner if: (a) the leachate does not adverse-
ly impact the permeability of the liner (as would be expected with dilute
inorganic, and possibly even dilute organic materials), and (b) a proper-
ly designed and managed leachate removal/disposal system is provided or
the site is in certain geological settings where a small leak rate is
acceptable.
• Organic fluids can substantially increase the permeability of compacted
clay soils; the permeability of prospective clay liners should be tested
using the leachate to which they will be exposed.
• Possible detrimental effects of differential settlement of waste on clay
caps are unknown. Long-term usefulness of caps for hazardous waste land-
fills is not known.
• There are no comprehensive data on successes and failures of flexible
membrane liners, nor is there long—term experience with liners in land-
fill situations. The data base for exposure of liners to hazardous waste
covers only a few waste streams.
• The technology does not now exist that would allow the proper installation
of flexible membrane liners. Also, the degree of quality control in
flexible membrane manufacturing plants is not acceptable; some new tech-
niques have been researched but are not yet in widespread use (e.g.,
spark-gap or vacuuri technology for pinhole detection).
• No liner presently on the market can stand up to the full range of chemi-
cals which might be found in a hazardous waste landfill.
• The use of alternative disposal techniques (e.g., incineration and land
treatment) and waste recycling should be encouraged, while the use of
“classical” landfills should be discouraged. The smaller volume of wastes
not disposable by these alternative techniques should be placed in above-
ground landfills where it is much easier to maintain, monitor, and clean
up the facility in the event of failure.
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Background
Dr. Kirk W. Brown is a soil scientist with the Soil and Crop Sciences
Department of Texas A&M University in College Station, Texas. Dr. Brown’s
major interest is with installation and testing of clay liners. He is the
author of several reports on the subject of the effects of organic fluids
on the permeability of clay soil liners. Dr. Brown has also published a
technical resource document for EPA on hazardous waste land treatment. Dr.
Brown is well respected in his field and has testified before Congress
concerning his studies and other hazardous waste disposal matters.
Current Research
• Laboratory investigations showed that organic fluids can substantially
increase the permeability of compacted clay liners. These findings in
part were regrettably responsible for the newly instituted regulations
that require flexible membrane liners. As soon as data were developed
with concentrated organic liquids, only one end of the spectrum, EPA
abandoned clay liners in favor of flexible membrane liners for lining
disposal facilities. There are several situations in which clay liners
may be acceptable, such as those facilities that would generate in-
organic leachate or possibly even dilute organic leachate.
• In the field study, 28 cells were constructed using reinforced concrete
and lined with a 100 mil thick high density polyethylene (HDPE) liner to
facilitate leachate collection. The field cells (with 1.8 cubic meter
volumes) were fitted with clay liners compacted to at least 90 percent
Proctor density. Perforated barrels containing a xylene paint solvent
waste or an acetone waste were placed in the cells. The cells were then
backfilled with sand and capped with a plastic cover and top soil. Per-
meability was calculated from the leachate volume using Darcy’s Law.
• Preliminary results of both laboratory and field cell tests indicate
that concentrated organic liquid-bearing wastes may alter the structure
of clay soils, resulting in permeabilities 100 to 1000 times greater
than the values measured with water. Visual observations of dyes and
chemical analyses of soil samples indicated that the wastes moved
through preferential channels in the soil mass and not along the edges
of the permearneters or test cells. The following should be considered
in evaluating this research effort:
- Dr. David Daniel (see Interview Report for University of Texas)
showed that the ratio of laboratory to field permeability test re-
suits can range from 0.5 to 4,000 with laboratory test results most
often indicating permeabilities 100 times lower than field tests
indicate.
- Control cells with water alone were not used in the study.
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- A number of scientific studies (Macey, 1942; Schram, 1981; Buchanan,
1964) supports the findings that organic liquids can greatly in-
crease the permeability of clay soils, while no studies have been
found that refute these results.
• Preliminary results of the field cell tests also indicated that 11 out
of 12 HOPE cell liners have leaked. These liners were installed accor-
ding to the manufacturer’s specifications under optimal conditions by the
manufacturer, using the same seanino techniques as prescribed in the field.
Referenced Flexible Membrane Liner Research
• The only actual study on flexible membrane liners (Montague, 1981)
indicated that 3 out of 3 landfills double—lined with various synthetic
liners were leaking contaminated liquid shortly after installation.
• Puncture resistance tests of flexible membrane liners covered with a
protective layer of soil indicated that all the materials tested
suffered puncture wounds (Gunkel, 1981).
• The many laboratory studies on flexible membrane liners conducted by
Haxo indicate deterioration of the physical properties of many of the
synthetic liners subjected to municipal waste leachate, including
swelling and loss of seam strength. None of the materials tested held
up to the range of hazardous wastes used (Fong and Haxo, 1981; Haxo,
1980; Haxo, 1981; Haxo, 1982).
• 1-laxo’s tests were of relatively short duration and were conducted without
replicate sampling. Also, despite these laboratory tests, field tests
are still needed to develop data which allow extrapolation of labora-
tory data to the field.
Extensions of Current Research
• The field and laboratory study on clay liner permeability using the
concentrated xylene and acetone wastes will continue for another 1 and
1-1/2 years. Fourteen of the field cells remain to be excavated,
photographed, and sampled. Laboratory studies on the influence of di-
lutions of water soluble organics are presently being conducted. It is
anticipated that further laboratory evaluations will include mixtures
of organic wastes and testing of polymer-treated clays. Morphological
studies are also under way, and efforts are being made to quantify the
changes in pore soil distribution which may occur as a result of organic
liquid interactions with soil.
Research Needs
• There is a need to investigate various techniques that would make land-
fills chemically and biologically stable. For example, constructing
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a drainage layer out of material that will attenuate pollutants in the
leachate, such as crushed limestone or activated charcoal. (Stabiliza-
tion is most easily accomplished with nionofills.)
• There is a need to research the bonding energies of clays with organics
versus water. Bulk studies show a correlation with the dielectric
constant of the solvent.
• There is a need to obtain liner performance data in the field (i.e.,
observing the performance of hazardous waste landfill liner systems).
• While clay caps are generally well designed, there is only very limited
field experience under conditions that would allow measurement of in-
creased infiltration (indicative of leaks), no information on the
potential effects of subsidence, and no long-tern performance data on
the subject of clay caps at hazardous waste facilities.
Perspectives on Design of Liners/Covers
• The requirement set down in 264.301 (EPA, 1982) that the waste be pre-
vented from passing into the liner during the active life of a facility
could obviously not be met for clay liners, and the requirement is
going to be difficult if not impossible to meet for flexible membrane
liners. Data on 12 liner materials tested with 8 different wastes in-
dicated that the wastes were absorbed in 89 out of 96 test specimens
(Haxo, 1981).
• In conjunction with above—ground landfills, EPA should discourage the
use of the classical landfills and encourage the use of techniques that
either destroy (incineration), degrade (land treatment), or recycle
hazardous wastes. The small volume of wastes untreatable by these
alternate techniques would be disposed in above-ground storage units.
Generally, with landfills on the surface, it would be much easier to
detect problems, monitor leachate, maintain the integrity of the system,
and clean up leaks. Two objections to this approach are: (1) poor
aesthetics and (2) erosion of caps. However, these can be mitigated by
placing a vegetative cover over closed cells and using proper land-
scaping techniques. It is difficult, however, to get engineers and
regulators to consider innovative systems when the Agency continues to
encourage the use of below-ground landfills, even though a large portion
of these facilities will likely require massive clean up operations in
the future.
• Liners should be selected which will provide the best long-term stabil-
ity and which will suffer minimum degradation by the leachates. These
liners will most likely be made of natural materials such as recompacted
or treated clays and will thus allow some slow movement of liquid.
Drainage systems must be required which will allow the continuous re-
moval of leachate for a period equal to the expected life of the
hazardous materials disposed of in the facility. This can only be
achieved by building land disposal systems on compacted clay liners
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above the surface of the soil. Such facilities could be equipped with
free gravity drains which would prevent the build-up of a head of free
liquid on the liner. Provisions must be made to collect and treat the
leachate as long as it is produced, or until the leachate is demon-
strated to be free of toxic constituents.
• Clay liners may be acceptable if the leachate is of such characteris-
tics that it doe.s not adversely impact the permeability of the liner
as would be expected with dilute inorganic, and possibly even dilute
organic chemicals. Clay liners may also be a viable liner material
where a properly designed and managed leachate removal system is pro-
vided and assurances can be provided that it will be maintained and the
leachate will be removed and disposed of until it reaches acceptable
quality. If a small leak rate is acceptable as may be possible for
facilities in certain geological settings, then clay liners may also be
the best long-term option. Careful laboratory and field testing are,
however, needed to determine if properly selected and compacted clays
provide sufficient protection of the environment for the particular
leachate to be retained.
• Design of a clay liner system in locations with large natural clay
deposits should consider that they are not uniformly permeable due to
sand lenses, roots, debris, and natural cracks and fissures.
Perspectives on Performance of Liners/Covers
• The main factors that affect liner performance are poor installation
techniques and disposal of concentrated liquid wastes.
• About 80 to 90 percent of the performance problems are related to in-
stallation. Factors such as changes in ambient temperature, wind-blown
dust, and changes in humidity, which all occur during installation,
cause problems with seaming. Thermal expansion of liner sheets (espe-
cially black ones) is a definite problem.
• Despite horror stories of leaking flexible membrane liners circulating
among those in the field, there is yet no compilation of either the
successes or failures of this technology. One study (Montague, 1981),
however, indicated that all three flexible membrane lined hazardous
waste landfills in New Jersey were leaking. In Dr. Brown’s study, 11
out of 12 field cells lined with one type of flexible membrane liner
have leaked. Unfortunately, there is no long-term experience with
these liners in landfill situations.
• Flexible membrane liners have successfully been used for lining water
reservoirs. They have been used succ essfully for retaining hazardous
waste in open ponds, where only a set of specified chemicals will come
in contact with a carefully selected material, and where constant sur-
veillance and monitoring is possible. Facilities which have functioned
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well for years have been known to fail quickly if suddenly exposed to
other chemicals which they were never intended to retain. 1-laxo (1980,
1982), after testing 12 flexible membrane liners with a series of
hazardous industrial wastes, concluded that “there does not appear to
be any single lining material now commercially available which is
suitable for long-term impoundment of all wastes”.
• Flexible membrane or clay liners cannot be installed under the current
regulations so that they do not leak. The very limited data available
on exposed membranes (Haxo, 1982) indicate degeneration of the materials
exposed to landfill conditions for 4-9 years. Pacey (1980) suggested
that even if flexible membrane liners were properly installed so that
they did not leak immediately, they would deteriorate 20, 30, or 40
years later. Pertusa (1980) suggested that seven flexible membrane
liners had useful lives of between 5 and 20 years for water impound-
ments and that the useful lives would likely be reduced when exposed to
wastes. Nonetheless, the Agency is now asking us to rely upon flexible
membrane liners to prevent discharge of dangerous chemicals which may
retain their toxicity for centuries (EPA, 1982).
• Kays (1977) reports that flexible membrane liner failures can be cate-
gorized into those resulting from physical, chemical, and biological
failures. Physical failure mechanisms include punctures which may re—
suit from traffic pressure even when the liners are covered (Gunkel,
1981), tears, creep, freeze-thaw cracking, wet-dry cracking, differen-
tial settling, thermal stress, differential hydrostatic pressure,
abrasion, and failure of seams (Haxo, 1982). Chemical failure results
from deterioration resulting from ultraviolet light, ozone, hydrolysis,
ionic species attack, extraction, ion species incompatibility, and
solvent attack which may dissolve either the plastic or the plasticizer.
Biological degradation includes microbial attack, attack by burrowing
animals, or as a result of animals trying to escape from inside the
facility.
• Many failures have been attributed to installation difficulties, in-
cluding seaming difficulties in the field and tears and rips occurring
during or shortly after installation. Furthermore, no liner presently
on the market can stand up to the full range of chemicals which might
be found in a hazardous waste landfill. If the membrane is resistant
to acids, it may be destroyed by oils; if it resists polar organics, it
may be destroyed by nonpolar organics.
• To obtain true performance data, one would have to examine the files of
the liner installers and manufacturers (e.g., to determine how many
times an installer had to repair a liner after installation, and why).
Perspectives on Construction and Installation
• The technology does not now exist that would allow the proper installa-
tion of flexible membrane liners.
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• A major problem with clay liner installation is dessication of the
liner. Installers are not preventing dessication cracks during instal-
lation or after installation, but before operation commences. In just
one day, dessication cracks can become 6 to 8 inches deep.
• An Australian firm, called Nylex, manufactured and installed a flexible
membrane liner; however, because of many pending law suits, they stopped
installing them.
Perspectives on QA/QC
• There are material problems associated with flexible membrane liners
as well as seaming and installation problems. The degree of quality
control in flexible membrane manufacturing plants is not acceptable;
some new techniques have been researched (e.g., using spark-gap or
vacuum tec inology to detect pinholes in the material), but they are
not yet in widespread use.
• Strategies such as writing QA/QC procedures into the regulations or
licensing installers will not significantly change the current situa-
tion. These strategies are simply additional attempts (“band-aid”
policy) to retrofitting an unsolvable problem.
Miscellaneous
• Solidification of liquid wastes (264.314) will work for certain aqueous
solutions or suspensions of inorganic materials and very low concentra-
tions of organic liquids. Thus, the technique should not be utilized
for organic liquids unless it can be fully demonstrated to be effective.
Otherwise, the liquids adsorbed on the solids used for stabilization
will only drain through capillaries from the solids when they are stacked
in the landfill, thus putting a direct head of liquid on the leachate
collection system and the liner. Consequently, the EPA’s regulations
should reduce but will not eliminate free liquids in landfills.
• Disposal of bulk liquids in landfills that require the use of synthetic
membranes is not adequate to protect the environment and should be
banned. They should be recycled (where feasible), treated, and dewatered
before disposal.
• A final concern centers around the lack of control over small quantity
generators which can continue to legally dispose of free liquids into
landfills. A few barrels of organic liquids may drastically alter the
permeability of a landfill liner, essentially pulling the plug from a
bath tube and thus allowing contaminated leachate to leak rapidly from
the facility. Dr. Brown recognizes that steps are being taken to regu-
late these policies; however, during the two years alloted to tighten
standards, thousands of barrels of liquid waste will be disposed of in
facilities which were not designed as hazardous waste landfills.
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References Cited By Brown
• EPA. 1982. Hazardous Waste Management System; Permitting Requirements
for Land Disposal Facilities. Federal Register 47(143): 32274-32388.
• Fong, M.A. and H.E. Haxo, Jr.
Municipal Solid Waste Landfills.
Land Disposal: Municipal Solid
Symp. EPA 600/9-81-002a. U.S.
nati, Ohio 45268.
• Gunkel, R.C. 1981. Membrane Liner Systems for Hazardous Waste Land-
fills. p. 131—139. In: 0. W. Shultz (ed.). Land Disposal: Hazardous
Waste. Proceed. Seventh Annual Res. Symp. EPA-600/9-81-002b. U.S.
Environmental Protection Agency, Cincinnati, Ohio 45268.
• Haxo, Jr. , H.E. 1980. Interaction of Selected Lining Materials With
Various Hazardous Wastes. II. p. 160—180. In: D. W. Shultz (ed.).
Disposal of Hazardous Waste. Proceed. Sixth Annual Res. Symp. EPA—
600/9—80-010. U.S. Environmental Protection Agency, Cincinnati, Ohio
45268.
• Haxo, Jr., H.E. 1981. Durability of Liner Materials for Hazardous
Waste Disposal Facilities. p. 140-156. In: D. W. Shultz (ed.). Land
Disposal: Hazardous Waste. Proceed. Seventh Annual Res. Symp. EPA-
600/9-81-002b. U.S. Environmental Protection Agency, Cincinnati, Ohio
45268.
• Haxo, Jr. , H.E. 1982. Effects on Liner Materials of Long-term Expo-
sure in Waste Environments. p. 191-211. In: D. W. Shultz (ed.).
Land Disposal of Hazardous Waste. Proceed. Eight Annual Res. Synip.
EPA-600/9-82-002. U.S. Environmental Protection Agency, Cincinnati,
Ohio 45268.
• Kays, W.B.
Pollution
1977.
Control
Construction
Facilities.
of Linings for Reservoirs, Tanks
Wiley Interscience, John Wiley and
and
Sons,
Inc.,
New
York.
379 pp.
• Macey, H.H. 1942. Clay-water Relationships and the Internal Mechanism
of Drying. Trans. Brit. Cer. Soc. 41: 73—121.
• Montague, P. 1981. Four Secure Landfills in New Jersey -- A Study of
the State of the Art in Shallow Burial Waste Disposal Technology.
Draft. Department of Chemical Engineering and Center for Energy and
Environmental Studies. School of Engineering/Applied Science. Prince-
ton University, Princeton, NJ 08544.
• Buchanan, P.N.
Permeability and
Montmorl loni te.
1964. Effect of Temperature and Adsorbed Water on
Consolidation Characteristics of Sodium and Calcium
Ph.D. Thesis, Texas A&M University.
1981. Assessment of Liner
p. 138-162. In: D. W.
Waste. Proceed. Seventh
Environmental Protection
Materials for
Shultz (ed.).
Annual Res.
Agency, Cincin-
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• Pacey, J. and G. Karpinski. 1980. Selecting a Landfill Liner. Waste
Age. 11(7): 26-28, 104.
• Pertusa, M. 1980. Materials to Line or to Cap Disposal Pits for Low-
level Radioactive Wastes. Geotechnical Engineering Report GE8O-1.
Dept. of Civil Engineering, University of Texas, Austin, Texas 78712.
• Schram, M. 1981. Permeability of Soils to Four Organic Solvents and
Water. M.S. Thesis, University of Arizona, Tucson, Arizona. 60 p.
• Seymour, R.B. Plastics Versus Corrosives. John Wiley and Sons. 1982.
References Supplied to TRW
• Brown, K.W.; J.W. Green; and J.C. Thomas. The Influence of Selected
Organic Liquids on the Permeability of Clay Liners. Draft Report.
1982.
• Anderson, D.; K. Brown; and J. Green. Effect of Organic Fluids on the
Permeability of Clay Soil Liners. In: Proceedings of the Eighth
Annual Research Symposium; March 8-Ta, 1982. EPA-600/9-82-002.
p. 179-190.
• Anderson, U.; K. Brown; and J. Green. Organic Leachate Effects on the
Permeability of Clay Liners. In: National Conference on Management
of Uncontrolled Hazardous Waste Sites. October 28-30, 1981.
• Brown, K. Testimony Before the House Subcommittee on Natural Resources,
Agricultural Research and Environment of the Committee on Science and
Technology. 30 November 1982.
• Brown, K. Landfills of the Future (a seven—page description of Brown’s
above-ground land storage concept). 15 December 1982.
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ASSESSMENT OF TECHNOLOGY FOR CONSTRUCTING AND
INSTALLING COVER AND BOTTOM LINER SYSTEMS
FOR HAZARDOUS WASTE FACILITIES
EPA Contract No. 68-02-3174; Work Assignment No. 109
INTERVIEW NO. D-4
Matrecon, Inc.: Dr. Henry Haxo TRW: Louis L. Scinto
Oakland, CA 415-451-2757
15 December 1982
Summary
• Quality assurance/quality control (QA/QC) during liner installation is
not given enough priority.
• Testina needs to be done on liner materials during installation to ensure
quality and uniformity, and to assure that the quality of the material
placed in the field is the same as that which was selected in the design.
• Inspection and testing of clay liners during installation should focus on
soil properties, roller characteristics, and characteristics of the com-
paction operation.
• Inspection and testing of flexible membrane liners during installation
should focus on subgrade preparation, seam integrity, and sealings
between the liner and penetrations.
• Correlations have not been established between results obtained during
QC testing and actual performance, i.e., performance cannot accurately be
predicted from results of field tests performed during installation.
Background
Dr. Haxo’s main area of research centers on testing of materials used as
liners in waste disposal facilities. He has performed and published the re—
suits of extensive research into the compatibility of various wastes and leach-
ates with liner materials (primarily flexible membranes) and has developed a
body of test methods needed to guide the selection and design of liners for
specific applications, ensure the quality of the desianed liner is as installed,
and monitor the condition of the liner during service. Dr. Haxo maintains an
up-to-date library of related research papers and reports on liner technology,
including both domestic and foreign sources. He is the principal author of
SW-870, EPA’s Technical Resource Document (TRD) on Lining of Waste Impoundment
and Disposal Facilities.
Highlights of the interview and of Dr. Haxo’s published work related to
liner installation are presented below under the following headings: (a)
general QA/QC and testing requirements; (b) QC testing during installation of
clay liners; (c) QC testing during installation of flexible membrane liners
(FML); and (d) relationship of test results to liner performance. Specific
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conclusions based on detailed review of documents published by and/or
obtained from Dr. Haxo will be included in TRW ’s final report on this
work assignment.
General QA/QC and Testing Requirements
• Generally, QA/QC during liner installation is not given enough priority.
This aspect of the job is of utmost importance in ensuring that liners
installed in the field meet all design specifications.
• Much of the research into general methods of inspection and testing has
been and is being done by the Bureau of Reclamation (largely for FML)
and by the Army Waterways Experiment Station (for clays). Specific test
methods have been devised by ASTM and preliminary work to define physical
requirements for FML based on these tests has been done by the National
Sanitation Foundation and other standard-setting organizations. This
body of work formed the basis for many of the guidelines presented in
SW-870.
• An adequate QA/QC program for installation should include at a minimum:
(a) a checklist to ensure all facility requirements are met; (b) a speci-
fic plan which addresses procedural inspections and sampling, testing,
and record keeping requirements; and (c) continuous monitoring and review
of all important activities.
• Testing requirements for the evaluation and assessment of liner materials
for waste impoundments fall into three general areas:
- Tests for the selection of liner materials and in the design of im-
poundments incorporating liners.
- Tests to ensure quality and uniformity of liners placed in the field,
and to assure that the quality of the material placed in the field is
that which was selected in the design.
- Tests for assessing performance and condition of liners in service.
The second of these areas has application to this work assignment. Gen-
eral aspects of this type of testing is discussed below for clay and
synthetic liners.
QC Inspection and Testing During Installation of Clay Liners
• The inspection/testing program for clay liners should assure that the
following aspects of the installation meet design specifications:
- Soil characteristics such as:
-- moisture content
-- density
-— permeability
—- infilterability
-- uniformity
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- Roller characteristics such as:
-- size, arrangement, and safety features of drums
—- number, location, length, and cross-section area of tamping feet
-- weight of loaded roller
- Characteristics of the compaction operation such as:
—— number of passes
—- thickness of lifts and variations in lift height
-- lift thickness in relation to length of tamping feet
QC Inspection and Testing During Installation of Synthetic Liners
• The important aspects of FML installation which need QC inspection and
testing are:
- Subgrade preparation
- Liner and seam properties
- Liner penetrations (e.g., for inlet/outlet structures or gas vents)
• QC procedures for subgrade preparation are similar to those for clay
liners -
• The integrity of the liner material particularly at factory and field
seams should be tested. Both non-destructive, in-place tests (such as
the air lance) and tests on random seams cut out of the liner should be
performed. Seam samples should be tested to determine their strength
(in shear and peel configurations), ply adhesion (where applicable), and
sensitivity to variations in ambient conditions (particularly temperature).
• Operations involving sealing between the liner and penetrations should
undergo careful visual inspection, and in-place testing of the integrity of
the connection should be performed.
Relationship of Test Results to Liner Performance
• Correlations of test results (which characterize specific properties of
installed liners) with actual field performance of the liner have not been
established. Field test results can only serve to indicate the quality
of the specific material under test and the degree to which the quality of
the installed liner is the same as the pre-installation quality observed
in the compatibility tests.
Miscellaneous Comments
• One problem with installing bentonite clay liners occurs when water is
added to the clay prior to compaction. Some of the water is not quickly
absorbed and, especially on slopes, can flow downhill to form puddles
at low spots. This produces a non—uniform distribution of moisture in
the liner, which can affect compaction.
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• In applying asphaltic liners, problems can occur if the material is too
hot. When applied to slopes, the material can flow downhill before
hardening, creating a liner of non-uniform thickness.
• Some states (for example, Pennsylvania) prefer man-made liners over clay.
• Waste/liner compatibility tests should be run for as long as possible.
Manufacturers generally run one week to bne month tests. Dr. Haxo be-
lieves at least four months are needed to identify potential compatibi-
lity problems.
• Cohesive energy density (CED) comparisons between liners and wastes (or
the most aggressive waste constituent) can potentially determine whether
a particular liner will be suitable to contain a specific waste. Small
differences in CED indicate that the waste may tend to dissolve the
liner.
• The firm of Hovater-Way Engineers in Laguna Hills, CA, has experience with
QA/QC programs for FML installation.
• The long—term integrity of asphaltic liners in general is hard to assess
because different grades have different properties (e.g., for water ab-
sorption). Asphalts are not pure chemicals and their properties vary
widely depending on their source and method of manufacture.
• Cool, dark, anaerobic service environments are generally conducive to long
life for flexible membranes.
• Some clays may be unacceptable as liners for long—term confinement of
some inorganic wastes. For example, if a soil has a low flocculation
value with the particular waste liquid that is permeating through the
soil liner, it is likely that the flux-density will be larger than the
one anticipated on the basis of the designed K-value with water.
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ASSESSMENT OF TECHNOLOGY FO CONSTRUCTING AND
INSTALLING COVER AND BOTTOM LINER SYSTEMS
FOR HAZARDOUS WASTE FACILITIES
EPA Contract No. 68-02-3174; Work Assignment No. 109
INTERVIEW NO. D-5
Denver Research Institute: William Culbertson TRW: Heather R. White
Denver, CO Charles Flabenicht
303-753-2911
16 December 1982
Summary
• The purpose of DRI’s research program is to develop materials suitable
for lining embankments of spent oil shales from the spent oil shales.
The program is in its preliminary stages and results are not currently
available.
• Major concerns of the program are minimizing brittleness and maximizing
impermeability and creepability of the liner material. The effects of
consolidation pressures on the liner must also be considered, since in
an actual installation 300 feet of spent oil shale may be placed atop
the liner.
• There are several possible ways to install liners of spent oil shale.
Four sample fabrication methods will be used to simulate these options
and determine which options will prevent cementation and brittleness.
The steps in the fabrication methods will be conducted at various tem-
peratures and pressures.
• The possibility of adding clays, silts or sands to the spent oil shales
to confer the desired properties on the liner will be explored by testing
combinations of materials as well as spent shale alone.
• The possibility of using spent shale for covers will not be specifically
addressed by this project because different properties are expected to
be important for cover materials.
• Perrneabilities of consolidated samples are expected to be on the order
of l07 cm/sec.
• The compatibility of the highly alkaline liner material with other
materials must be determined before its use with other wastes is consi-
dered.
• The potential effects of groundwater on these liner materials will not
be addressed in this study but must be determined before the materials
are used in the field.
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Background
EPA/IERL in Cincinnati, OH, has contracted the Denver Research Institute
(DRI) of Denver to conduct a study of the possibility of developing liner ma-
terials from spent oil shales. Under the direction of Dr. William Culbertson,
DRI is conducting a number of tests on spent oil shales from various processes
to determine what properties are obtained under various conditions and what
properties are desirable for a liner beneath an t embankment” of spent shale
(this embankment would consist of a 300-foot pile of spent oil shale). DRI is
now beginning to test the materials and will continue the program through
1984, so results of the study will not be available for some time. TRW ’s
purpose in visiting DRI was, therefore, to determine the nature, not the
results, of DRI’s work. Copies of DRI’s third and fourth progress reports
were obtained.
The following sections describe DRI’s current research program, possible
applications of this work to the subject EPA hazardous waste program, DRI’s
research concerns, and similar research by other organizations.
Current DRI Research
• The purpose of this research program is to develop liner materials from
spent oil shales. The materials will line embankments of spent shale
much as clay might line a land disposal facility.
• The tests to be conducted for this program are designed to determine how
to maximize the production of materials with clay-like properties such
as impermeability and creepability. At the same time, it is desired to
minimize the production of cernentitious reactions and resultant cement-
like properties such as brittleness.
• Both the combinations of raw materials used and the processes they under-
go in becoming liner materials will be varied in the attempts to maximize
impermeability and creepability and minimize brittleness. The contribu-
tion of different minerals to the development of clay- or cement-like
properties and the chemical reactions that occur will be studied.
• Raw materials to be tested in this program include bentonite, Portland
cement, and several types of silts, sands, and spent shales. The clays,
cements, silts, and sands will be used as additives to the spent shales.
Silts and sands to be used include siliceous and calcareous fly ash and
fine silica sand. Spent shale types include unburned and burned shale
from the Tosco II process, ground unburned and burned shale from the
Union B process, and well-burned and mildly-burned shale from the Lurgi
process.
• Spent oil shales will be tested alone or in combination with the other
materials listed above. Firie-grained materials (clays and spent shales)
appear to have the greatest potential in this research. However, coarser
(silty) material may be added to reduce brittleness and to reduce the
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plasticity index to 10—20. Clays may be added to alleviate quick-clay
tendencies. Shales that have been subjected to high temperatures in an
autoclave to spend their cementing powers may be tested alone or blended
with other materials to obtain a less brittle liner material.
• The effects of consolidation pressures will be examined by the program.
In practice, the spent shale liners are to be placed in thicknesses of
up to twenty feet, depending on the potehtial for subsidence. Up to 300
feet of spent shale are to be placed atop the liner, and a cover will be
placed over this structure. This will subject the liner to high conso-
lidation pressures.
• Installation of liners made from spent oil shales must be done in a way
that minimizes cementation and brittleness. Placing and compacting these
liner materials in the same way natural clays are placed may cause the
material to cement. To avoid this, several alternative placement methods
are being considered. One option is to “knead it as it is placed to
break up the cementation reaction. Another is to place it and let it
consolidate under its own weight or with a small amount of embankment
material placed atop it. A third option is to place all the embankment
material on the liner’ at once immediately after the liner is placed; this
might break up the cementation reaction. All three of these options will
be explored through the testing program.
• Four basic methods will be used to prepare and fabricate liner materials
from combinations of the raw materials listed above:
- Sparse moisturization, immediate simple compaction, consolidation,
and secondary consolidation with aging. This simulates the embankment
construction methods usually proposed by developers.
- Ample moisturization, heap mellowing for approximately 14 days, delayed
compaction and consolidation with the final material nearly saturated.
It is thought that the moisture and mellowing period will spend much
of the cementing potential of the materials before they are placed.
- Slurry mellowing, slow cooling, and partial air drying or flash cooling
and drying, vacuum extrusion or compaction, consolidation, and secon-
dary consolidation with aging.
- Blending of solids into slurry-mellowed product, followed by heap
secondary mellowing.
The above methods will be conducted at several different cure tempera-
tures, cure times, and consolidation pressure combinations.
• This research program will not consider the use of spent oil shales for
cover material. The program is designed to examine the ‘ self-healing”
properties of the material and the effects of consolidation pressure on
the material. Neither of these factors is of great concern for a cover,
which can be reached more easily for repair than a liner can, and which is
not subjected to the high consolidation pressures a liner is subjected to.
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• Initial spent shales will be analyzed using the following methods:
— Elemental analysis.
— Mineral carbon (carbonate) analysis.
- Total carbon analysis.
- X-ray diffraction analysis.
— Sieve analysis.
- Hydrometer size analysis.
- Mineral grain specific gravity.
— BET surface area.
• Fabricated liner materials will be tested for chemical composition and
aggregative mechanical properties. In addition to the analyses listed
above, moisture content, material balance, liquid limit, plastic limit,
void ratio, compressibility, permeability, shear strength, tensile
strength, and brittleness index will be determined. Scanning electron
microscope pictures will also be taken.
• Permeabilities of consolidated samples are expected to be on the order of
i 7 cm/sec. Permeabilities as low as lO- cm/sec have been measured
during preliminary tests of unconsolidated samples.
Applicability to Hazardous Waste Facilities
• The compatibility of the liner material with other materials must be de-
termined before its use with other wastes is considered. Burned shale
tends to be highly alkaline. The alkalinity may assist in immobilizing
some materials (e.g., metals), but it may cause adverse reactions with
other materials (e.g., acids).
• The primary purpose for liner materials made from spent oil shales is
envisioned to be on—site containment of spent shale. However, it has
been suggested that spent catalysts could possibly be disposed with the
spent shale. These catalysts may contain hazardous metals, which might
be partially immobilized by the alkaline spent shale material.
• Spent oil shale is not currently listed as a hazardous waste. It is
possible that some organic materials may remain in the spent shale, but
since most retortina processes attempt complete burning, there should be
little or no remainino orcianics*. Spent shale can, however, contain
certain metals (e.g., arsenic) which are considered hazardous. The em—
bankments of spent shale could, therefore, be considered hazardous waste
facilities in the future.
*F.Iowever, these organics could be hazardous.
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Research Concerns
• DRI is concerned about the effects of groundwater on liners made of
spent oil shale. Groundwater high in carbonates and sulfates could
“attacks’ the liner in the same way it attacks Portland cement.
• The embankment is to be so thick and will be so dehydrated that any
water coming through the cover would probably be soaked up by the em-
bankment and would not reach the liner. If the embankment was cracked,
however, water could reach the liner from above. If a large amount of
water leaked through a large crack in the embankment, erosion of the
liner might be a problem. However, the chances of this occurring are
quite small.
• DRI is collecting references dealing with the nature of clays for their
work. They are particularly interested in data regarding the shear
strength and creepability of clays and on the evaporation of water from
clays.
Research by Other Organizations
• Monsanto has been involved in similar work but is presently waiting to
see the results of DRI’s work before proceeding.
• Several oil shale developers have examined the properties of spent oil
shale. Much of their research has been focused on determining the re-
lationships between moisture content and cementation and compactibility.
These are several of the organizations involved:
— Occidental has studied spent oil shales from the Lurgi process.
— Tosco has studied their own spent oil shales.
- Paraho has studied properties of ernbankments of spent oil shale.
Mr. Holtz of Woodward-Clyde has been involved.
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ASSESSMENT OF TECHNOLOGY FOR CONSTRUCTING AND
INSTALLING COVER AND BOTTOM LINER SYSTEMS
FOR HAZARDOUS WASTE FACILITIES
EPA Contract No. 68-02-3174; Work Assignment No. 109
INTERVIEW NO. D-6
U.S. Army Corps of Engineers: Capt. Michael Kelley TRW: Michael D. Powers
Waterways Experiment Station 601-634-3378 Michael T. Haro
Vicksburg, tIS
16 December 1982
Summary
• Research for EPA on covers has resulted in two reports: “Design and
Construction of Covers for Solid Waste Landfills” and “Evaluating Cover
Systems for Solid and Hazardous Waste”. Causes of failure and remedial
measures have also been studied.
• In NRC-sponsored work, parameters necessary for site characterization and
design of disposal trenches for low level waste facilities were evaluated.
• A draft QA/QC program for construction of disposal facilities has been
submitted to EPA for review.
• There is not enough actual field data currently available to adequately
evaluate the performance of liners. Clay generally performs fairly well
as a liner material due to its low permeability and filtering effects on
1 eachate.
• Operators of disposal facilities must be able to put confidence in their
liner systems; however, the lack of adequate standardized testing proce-
dures and data on proven performance results in very little confidence on
the part of the operators.
• If a facility has been properly designed, and an appropriate liner material
chosen, the most important factor in ensuring a successful liner is in-
stall ation.
• Care must be taken by men and equipment working on top of a liner to pre-
vent damage.
• Site-specific QAIQC requirements in the facility permit allows flexibili-
ty and the development of programs to meet site—specific needs.
• Subsidence of the fill can result in rupture of the cover; while this can
occur with any cover material, the problem is worse for relatively in-
flexible liner materials.
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Waterways Experiment Station
Page 2
Background
The Waterways Experiment Station (WES) of the U.S. Army Corps of Engineers
at Vicksburg, MS, has been conducting research into various aspects of design,
construction, and operation of land disposal facilities for EPA, NRC, and
other agencies for a number of years. Current activities center on liners and
covers for hazardous waste facilities.
As part of the data acquisition effort for this project, several key tech-
nical staff at WES were interviewed. The objectives of these interviews were
to obtain information on the following: (a) background, results, conclusions,
and recommendations from research to date; (b) recommendations for future re-
search; (c) perspectives on liner and cover performance, design, and installa-
tion, and on QA/QC requirements; and (d) additional references and data sources
to be contacted. The interviews consisted of a joint discussion meeting
attended by several WES technical staff, separate interviews with a number of
specific individuals, and a follow-on call to one individual who was not avail-
able during TRW’s visit to WES. This report integrates results from all of the
individual interviews.
The following persons at WES attended the large joint discussion meeting
which was arranged by Capt. Michael Kelley:
• From the Soil Mechanics Division, Geotechnical Laboratory
- Capt. Michael Kelley, Engineer, 601-634-3378
- Patrick G. Tucker, Engineer, 601-634-2710
- Paul Miller, Civil Engineer; 601-634-3247
• From the Engineering Geology and Rock Mechanics Division, Geotechnical
Laboratory
- Cohn C. McAneny, Geologist, 601-634-3954
• From the Pavement Systems Division, Geotechnical Laboratory
- George Regan, Engineer, 601-634-2728
• From the Environmental Engineering Division, Environmental Laboratory
- Dr. Phil Malone, Geologist, 601-634-3960
- Robert J. Larson, Geologist, 601-634-3959
The separate interviews were with:
• Dr. Joseph Spigolon, Civil Engineer, 901—454—2746. Dr. Spigolon is from
Memphis State University, but has worked the past summer with Capt.
Ke 11 ey.
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Interview No. D-6
U.S. Army Corps of Engineers
Waterways Experiment Station
Page 3
• Dr. Richard J. Lutton, Geologist, 601—634-3393; Engineering Geology and
Rock Mechanics Division, Geotechnical Laboratory.
• William Murphy, Geologist, 601-634-3322; Engineering Geology arid Rock
Mechanics Division.
• Paul Gilbert, Soils Engineer; Soils Engineering Division, Geotechnical
Laboratory.
The telephone interview, which was carried out on 13 January 1983, was
with:
• Gordon Carr, Engineer, 601—634-3387; Pavement Systems Division, Geotechni-
cal Laboratory.
Current Research
• Dr. Lutton has managed an EPA study of covers for solid and hazardous
waste landfills. The project has produced two reports: “Design and Con-
struction of Covers for Solid Waste Landfills” and “Evaluating Cover
Systems for Solid and Hazardous Waste”.
• As part of Dr. Lutton’s work for EPA on hazardous waste landfill covers,
he is evaluating the efficacy of cover designs at various disposal facil-
ities. Problems being investigated include those that occur after facil-
ity closure and their repair. One of the case studies investigated was
at a municipal landfill at l4indham, CT. At that site, a cover system
consisting of a PVC membrane covered by local glacial soil and aged sewage
sludge to support vegetation was completed in 1980. After only a few
months, erosion had occurred at several places, exposing the PVC meni-
brane. The erosion was directly attributable to run-off after the vege-
tative cover had failed to grow. The damage was successfully repaired by
placing coarse gravel, rock tailings, and a geotextile in the eroded
areas. Based on this investigation, in designing covers, considerable
attention should be given to:
- Cover surface topography, including configuration, slope, and texture
of drainage pathways.
- Condition of soil co er and/or age of sewage sludge, where used to
support vegetation, in order to ensure successful growth.
- Time of seeding, to ensure adequate time for vegetation growth before
heavy rains.
- Adequate post-closure inspection.
• In an NRC-sponsored study, Dr. Lutton is evaluating geological, hydrolo-
gical, and engineering parameters critical for characterizing sites for
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Waterways Experiment Station
Page 4
disposal of low level radioactive wastes. NRC regulations require dis-
posal facilities to control migration of radionuclides for at least
100 to 500 years following facility closure. The NRC prefers to mini-
mize leachate generation and to choose sites that will allow fluids to
drain slowly, rather than containing them in the disposal unit, thus
avoiding a “bathtub” effect.
• Mike Kelley and Joseph Spigolon have completed work and co-authored a
report on Geotechnical Quality Assurance of Construction of Disposal
Facilities; a draft has been submitted to EPA for review. Objectives
of the work were to: (a) identify geotechnical parameters that should
be tested in a QA/QC program; (b) recommend test methods; and (c) de-
velop a QA/QC program. The QA program development became the main part
of the project. A similar project by Spigolon, Kelley, and Herb Johnson
was underway at the same time for NRC. In general, the recommendations
in the two reports are similar, with differences reflecting the respec-
tive points of view of and types of wastes being regulated by the two
agencies. Major differences between the two agencies are that NRC
mandates a QA program to the licensee, while EPA expects the permittee
to check himself. The EPA report requires documentation of QA/QC tests.
A “watchdog agency”, responsible only to EPA, will make sure the documen-
tation is done properly; acceptance testing will be performed by the
permittee, and checked by the “watchdog”. Facility operators will have
a design group, an operation group, and an inspection group. The inspec-
tion group will maintain documentation that cannot be falsified, and a
test plan, to be monitored by the watchdog. The design group will review
the inspection reports and make any indicated changes.
• Effects of subsidence on liners and covers at RCRA hazardous waste land-
fills are being studied by William Murphy and Paul Gilbert using a finite
element model. Input to the modified CLOUGH finite element model program
includes “real world” values for physical properties, such as density and
shear strength of the liner, waste, fill, and cover, as well as loading.
They are starting with a simple model of a compressible solid with no
large voids, and vertical strain only. The model will account for layer-
ing of waste and fill. The model should indicate whether subsidence
results in ponding or rupture of the cover material. In addition, Murphy
and Gilbert will be reviewing the existing data base and make site visits
to determine design characteristics that have affected the occurrence or
non-occurrence of settlement.
• Additional research areas include:
- Work is currently underway on an NRC study on Trench Design and Con-
struction Techniques for Low Level Radioactive Waste, by Pat Tucker.
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Page 5
- Cohn McAneny, Pat Tucker, Mike Kelley, and Paul Miller are working
on the preparation of a Technical Handbook on Cover Design and
Construction at Uncontrolled Hazardous Waste Sites for EPA (Bob
Landreth, EPA Project Officer).
- Using scaled-down loads and pressures, Gordon Carr has developed a
laboratory method of measuring puncture resistance and wear of flexible
membrane liners that duplicates the results of small-scale field tests
performed by Robert Gunkel. The field tests were designed to measure
the effects of heavy construction equipment on flexible membrane liners.
- Treatment and solidification of hazardous waste for co-disposal with
municipal wastes.
- Grout sealing beneath existing disposal facilities.
- Developing standards for geotextiles.
Recommendations for Future Research
• Puncture resistance and wear of synthetic liners (including field seams)
need to be studied on a large scale in the field to supplement current
WES laboratory investigations. (Additional laboratory puncture resis-
tance tests still need to be conducted for a number of FI’lLs before field
tests can begin.)
• Because of disposal unit conditions that may result in contact between
waste constituents and the cover material (e.g., volatilization of or-
ganics, “bathtub” effects, etc.), there is a need to investigate the pro-
bability and magnitude of waste/cover compatibility problems.
• Acceptance test methods that lend themselves to a QA/QC program need
to be developed to give the permittee adequate confidence that his
installed liner will perform to design specifications.
• Research should be conducted into the relative effectiveness of various
types of seaming techniques for synthetic liners.
• Long-term performance of cover systems will be investigated in the near
future by Dr. Lutton.
Perspectives on Liner and Cover Performance and Installation
1. Performance
• There is currently an inadequate data base to evaluate whether liners
can be installed under the present regulations without leaking. More
field experience with liners of all types will be necessary before the
question of liner performance is settled. It appears that quality
assurance, operation, and maintenance practices have been performed
adequately in many instances. The weak link may be in the beginning -
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Waterways Experiment Station
Page 6
can the material (clay or synthetic) perform as designed? If the mate-
rial is adequate, how can the permittee be assured that the material as
installed will meet design specifications.
• Choosfng the correct liner material for a particular facility can be a
big problem and is critical for successful facility operation. When
choosing a liner material, it is important to specify not only the waste
types, but also the environment and setting. There are applications
where the environment itself may cause deterioration of the liner; as an
example, expansion and contraction in high temperature environments make
HDPE difficult to seam. Also, after seams are made, the stresses gene-
rated by the expansion and contraction of exposed seam pieces might cause
the seam to fail. There are drawbacks found in both Schlegel’s and
Gungle’s products. There may be facilities where a material that is un-
satisfactory for many other applications is the best that can be chosen
to match a site—specific situation. Where differential settlement is
possible, brittle materials (e.g., soil cement) should be avoided.
• There have been a number of problems with seams in synthetic liners.
This has been especially true for reinforced materials; leachate seeps
into the exposed scrim at the edges, resulting in a failure between the
laminations.
• The objective of engineers is to solve problems; some solutions may not
be perfect, but some approach that goal. A good solution to the problem
of liner performance is the use of a double liner with a compartmented
leachate collection system. Such a liner system would approach the ideal
of 100 percent containment; it would also be very expensive.
• In general, clay is a good liner material. It acts as a filter, ad-
sorbing many contaminants from the leachate.
• Disposal facility operators must have confidence in the liner material
used. Because of the possibility of litigation if the liner fails,
operators cannot take chances. However, there are currently insufficient
standard methods of testing, and insufficient data base on proven per-
formance for most liner materials; operators use liner materials at their
own risk. For this reason, operators tend to be very conservative in
their approach, using only materials that have a reputation for effecti-
veness.
2. Liner and Cover Installation
• The most important factor in ensuring a successful liner is installation
and soil cover placement, if the facility has been properly designed,
and the appropriate material has been chosen. A facility in Sheffield,
IL, is an example of where installation problems can result in difficul-
ties in meeting specifications for clay liners.
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laterways Experiment Station
Page 7
• Subgrade preparation is important. The subyrade should be well-compacted;
some materials are very susceptible to damage from differential settle-
ment. The surface should be free of sharp stones that can puncture syn-
thetic liner material.
• Damage to synthetic liners can occur during storage and handling prior to
installation. Potential sources of damage include:
- Folding and unfolding - Crimps in the material will result in weak
spots that can fail readily.
- Wind damage - Relatively gentle breezes (as little as 10 mph) can
easily lift and tear liner sheeting.
- Sun - The ultraviolet component in sunlight damages a number of syn-
thetic materials, especially PVC.
- Mechanical - Machinery can tear or stress material.
• During seaming with extrusion welding systems, such as those used for
HOPE, if the ribbon of extrudate is interrupted, there is no seam.
• It is important that a liner be protected from damage due to the opera-
tion of construction equipment. Buffer layers, both over and under the
liner, must be thick enough to keep objects frcm puncturing it. For
example, a landfill compactor with 6—inch cleats runnina over a 4—inch
layer of soil is a sure way of perforating the material.
3. Problems Unique to Covers
• The major sources of problems during installation of synthetic membrane
covers are:
- Holding the material in place during placement and seaming to prevent
wind damage.
- Seaming, both factory and field; failure of seams can allow moisture
to seep into the fill.
- Equipment operation during placement of soil over the membrane; impro-
per operation can puncture the membrane.
- The insufficiency of QA/QC tests and/or observations detracts from
the permittee’s confidence in the performance of his installed liner.
• Inadequate compaction of waste and fill can cause excessive subsidence,
which can result in rupture of the cover. Rupture will occur with any
material, those with low tensile strength, or those with little elongation
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U.S. Army Corps of Engineers
Waterways Experiment Station
Page 8
prior to rupture. Differential subsidence can also result in ponding,
which in turn will allow increased percolation, and will also disrupt
leachate collection systems.
• Erosion of material from the cover can result in exposure of the wastes.
This occurred at Sheffield, IL, where low level radioactive wastes were
covered with a collapsible bess. Factors that can promote erosion, or
directly expose the wastes, include:
- Vehicle traffic over covered trenches before or after final grading
and vegetation. Traffic can consist of trucks working on other
trenches as well as the covered one. Tire ruts are conducive to
erosion.
- Selection of a cover soil susceptible to erosion such as bess, or
that is not conducive to vegetative growth.
- Surface disturbances such as a farmer plowing.
- Burrowing animals.
- Frost heave.
• Gas generated in a landfill should be collected and vented through the
cover. When gas or vapors from volatile chemicals are not removed, ex-
pansion and contraction of gases in the fill with variations in atmos-
pheric pressure will result in rupture of the cover.
• Contrasts in permeability between a fine-grained (e.g., clay) cover and
coarser-grained fill can produce a ‘wick effect. Because of the high
capillary attraction in fine soils, moisture will not flow across the
interface to the high permeability material until the low permeability
soil is saturated. This effect will act as a barrier to unsaturated
flow into the fill material.
• After closure, landfills should be monitored for water ponding in closed
depressions caused by subsidence.
• it is possible, but not inexpensive, to install cover systems under the
present regulations so that they will not leak. Good installation tech-
niques, inspection, and maintenance are very important in establishing
the integrity of the cover.
• When considerinq a soil liner for caps, clay is not the only material
choice. Depending on site characteristics, other types of soils are
acceptable. For example, in dry climates a soil that will not crack may
be more effective than clay.
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U.S. Army Corps of Engineers
Waterways Experiment Station
Page 9
4. QP./QC Requirements
• EPA should mandate specific Q /QC requirements in permits, rather than in
the regulations. This will allow more flexibility in specifying a QA/QC
test program appropriate for the site and liner being installed.
• Installation quality would be improved by having guidelines for QA/QC
programs in the regulations, and by certification of installers. EPA
training and certification of installers would help to ensure that only
qualified people were doing such work, in much the same way that training
and certification programs ensure that only qualified people perform
blasting. Training and certification programs could be funded by a “user
fee included in the facility permits.
• The concept of third parties conducting installation QA/QC programs has
merit. One possibility would entail an EPA ‘watchdog” agency to moni-
tor installer QA/QC programs; the installer QA/QC group would submit
documentation that could not be falsified to the “watchdog”.
• Manufacturers of synthetic liner materials should be required to submit
their products to an outside testing agency such as the National Sanita-
tion Foundation for testing and approval . They should then be required
to affix the NSF seal of approval to the material produced.
• QA/QC procedures should be added to the regulations on the condition that
they are carefully prepared and properly qualified. The most important
aspect of QA is monitoring the installer’s work via visual inspection and
appropriate field tests. A third party QA program should be added to the
regulations only if it will not involve additional costs as would be the
case when the third party is already on—site or close to the site (e.g.,
state inspectors).
References Cited
The following documents were cited by interviewees at WES. A copy of the
first was supplied to us by Dr. Lutton; the second was supplied by EPA, and a
copy of the third was supplied by Dr. David Daniel of the University of Texas
at Austin. TRW has copies of all but the last two in its possession; the
last two will be acquired for use in the preparation of the final report.
• Lutton, R.J. Characterization of Sites for Low-Level Waste Disposal
Facilities. 1982 Nuclear Science Symposium, IEEE, 3 pp.
• Kelley, M. and S.J. Spigolon. Geotechnical Quality Assurance of Con-
struction of Disposal Facilities.
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U.S. Army Corps of Engineers
Waterways Experiment Station
Page 10
• Pertusa, M. Materials to Line or to Cap Disposal Pits for Low-Level
Radioactive Wastes. Geotechnical Engineering report GR 80-1, Dept. of
Civil Engineering, University of Texas, Austin, 1980.
• Lutton, R.J., G.L. Regan, and L.W. Jones. Design and Construction of
Covers for Solid Waste Landfills. EPA-600/2-79-165. August 1979.
• Lutton, R.J. Evaluating Cover Systems for Solid and Hazardous Waste.
SW-867. September 1980.
• Gunkel, R.C. Membrane Liner Systems for Hazardous Waste Landfills. In:
Land Disposal; Hazardous Waste Proceedings of the Seventh Annual Research
Symposium, March 16-18, 1981. EPA—600/9-8l-002b. pp. 131-139.
• Lutton, R.J., V.H. Torrey, and J. Fowler. Case Study of Repairing Land-
fill Cover. In: Land Disposal of Hazardous Waste, Proceedings of the
Eighth Annual Research Symposium. EPA-600/9-82-002. pp. 486-494.
• Tucker, P.G., et al. Trench Design and Construction Techniques for Low-
Level Radioactive Waste.
• McAneny, C.C., et al. Technical Handbook on Cover Design and Construction
at Uncontrolled Hazardous Waste Sites.
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ASSESSMENT OF TECHNOLOGY FOR CONSTRUCTING AND
INSTALLING COVER AND BOTTOM LINER SYSTEMS
FOR HAZARDOUS WASTE FACILITIES
EPA Contract No. 68-02-3174; Work Assignment No. 109
INTERVIEW NO. D-7
U.S. Bureau of Reclamation: Bernard Jones TRW: Heather R. White
Ron Frobel
Chester Jones
303-234-7044
16 December 1982
Sumnia ry
• The U.S. Bureau of Reclamation (USBR) has many years of experience with
a variety of liner materials. USBR has used liners primarily for water
supply systems where the goal of the liner project was to reduce seepage,
not to prevent it.
• Clay and synthetic materials each have a proper role as liners, depending
on material quality, availability, and cost, site considerations, and the
required level of seepage control.
• Good quality assurance (QA) is important both in soil and flexible mem-
brane liner construction. In the case of flexible membranes, a good QA
program is essential to good perfornance. USBR has had better success
with flexible membranes than others have with flexible liners, primarily
because of its comprehensive QA program.
• For soil liners, laboratory tests on proposed soils, conducting soil
density tests for construction control, compacting soil within two
percent of optimum moisture content, and compacting soil to 95 or 98
percent of Proctor test density are important elements of a good QA
program.
• For flexible membrane liners, a good QA program begins with inspection of
manufacturing, fabrication, and laboratory facilities. Test methods must
be coordinated among those responsible in order to assure compatible test
results. All parties involved must be experienced in the work to be done.
• Thorough field inspections include peel tests of cut—out seam samples.
Peel tests proved more effective than shear tests, and cut-out samples
were more representative of actual seam quality than mock seam samples.
• Coupon programs should be conducted after installation to monitor liner
quality.
• EPA should have some regulations regarding QA procedures because they are
the key to liner longevity.
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Background
The U.S. Bureau of Reclamation (USBR) has responsibility for federal water
and power resource projects of the Department of the Interior. Its Engineering
and Research Center designs water and power supply facilities, and conducts
research that will benefit the design and construction of these facilities.
One area of long-standing interest has been materials which can be used to line
earthen structures such as canals and reservoirs. Materials used and studied
have included compacted earth, asphalt, flexible membranes, and concrete.
The USBR began using and studying compacted earth linings in the 1940’s
and investigated many aspects of soil use, including permeability, lift thick-
nesses, moisture content vs. density, costs, frost action, and soil additives.
Although they stopped using asphalt in the 1970’s, the USBR used many hot-
applied and catalytically blown buried asphalt liners. In the 1950’s, they
began to use polymer linings. Most of their experience has been with poly-
vinyl chloride (PVC), but they have also used polyethylene (PE), CSPE, CPE,
butyl, and various copolymers. The USBR has not used many of the rubber
products because their main virtues are as exposed membranes, for which the
USBR has less need since most of its membranes serve as buried liners in
canals or reservoirs.
The USBR has used liners primarily for water supply systems where the
goal of the liner project has been to reduce seepage to a reasonable level,
not to prevent it entirely which is not practicable. For earth-lined
structures, the design seepage rate used by USBR engineers is less than 0.1
ft3/ft 2 -day. In some flexible membrane—lined facilities, liner sections were
overlapped but not seamed since the goal was not prevention of seepage and
any reduction in water losses was considered an improvement. Some of the
USBR’s data, therefore, may not be comparable to data from installations
where prevention of seepage is desired. However, their liner degradation
studies and more recent installation projects should be of general interest.
When the USBR began lining its water supply facilities in the 1940’s, the
use of a liner had to be justified economically. The value of water has risen
so that now they must justify not lining a facility. The issue today is one of
choosing a liner system that will provide the desired seepage rate at the least
cost.
The following describes USBR’s projects and research, their perspectives
on quality assurance and reaulations, related research, and research needs.
Additional contacts and references are also provided.
Bureau of Reclamation Projects and Research Results
1. Compacted Earth Linings
• An example of the USBR’s use of compacted earth linings concerns a brine
evaporation pond in New Mexico that was part of a salinity alleviation
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experiment to reduce brine seepage from an aquifer which was polluting
the Pecos River. A liner was constructed in a 52-acre natural depres-
sion by scarifying the top 18 inches of in—place soil, moistening this
soil with brine, and recompacting the soil with a vibratory roller.
This pond was operated from 1963 to 1976, when the pond had filled with
brine.
• Samples of this soil lining were taken in March 1982. Results of chemi-
cal and physical tests showed that the density of the soil lining had
increased by approximately ten percent and that its seepage rate was
reduced to 0.2 mm/day, about one-tenth the seepage rate calculated during
the first year of pond operation.
• The increased density and decreased permeability of the liner may have
resulted from the deposition of salt in the soil voids (as observed in
electron microscope photographs). The chemical properties of the soil
were not observed to have changed much. However, osmosis and chemical
reactions between the salt and clay in the soil may have caused some of
the observed physical changes. The possible causes of these phenomena
are still being studied. The results of this and related studies will be
useful in designing linings for brine evaporation ponds and salt gradient
solar energy ponds, an on-going USBR project.
• Although the use of a scarified and compacted soil liner was successful
in the above case, this is not the USBR’s usual procedure nor do they
recommend its use. The usual procedure is to build up linings in 6-inch
thickness to design depth.
• The USBR’s engineers use a seepage rate of less than 0.1 ft 3 /ft 2 -day to
design earth-lined facilities. In two large-scale tests of concrete and
soil in California, both attained seepage rates of 0.05 ft 3 /ft 2 -day.
2. Admixed Lining Materials and Soil Additives and Sealants
• Asphalt may be a desirable liner material in some situations because of
its flexibility. However, it has become expensive in the U.S. U.S. con-
tractors are not as knowledgeable or experienced with asphalt as their
European counterparts. Asphalt is more widely used in Europe than here
even though more of it must be imported there. Start-up costs for
asphalt are higher here than in Europe.
• The USBR has studied the use of bentonite, sodium carbonate, soil cement,
and fly ash as soil sealants and additives. Attempts to add bentonite
and chemicals to canal liners by adding them to the flowing canal water
were not very successful as the additives failed to penetrate signifi-
cantly below the canal surfaces. A 22 percent sodium carbonate solution
sprayed on two canals initially reduced seepage from 120 to 50 mm/day in
one canal and from 600 to 290 rn/day in the other. However, the seepage
reduction was only temporary; after one season the beneficial effects of
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the sodium carbonate had diminished considerably due to erosion and
other factors. It is possible that the sodium carbonate might have
been more effective if it had been mixed with the soil instead of
sprayed onto it.
• The USBR has experimented with both compacted and plastic types of soil
cements. Cracking and shrinking are potential problems when working
with soil cements. Good installation practices and the proper amount
of cement are vital to the success of a liner incorporating soil cement.
• Soil cement is particularly valuable for protection against erosion. In
Nebraska, silty loessial soil stabilized with 4-1/2 percent cement was
able to resist the erosion forces.
3. Flexible Polymeric Membranes
• During the summer of 1980, the USBR installed 290 acres of 45-mu re-
inforced chlorinated polyethylene (CPER) in the Mt. Elbert Forebay Re-
servoir in Colorado. CPER was selected because: (a) a consistently good
quality seam can be produced with the material; (b) a reinforced material
suitable for placement on the side slopes of the forebay was desired; (c)
manufacturing problems they had identified in the past (e.g., too much
creep in the material) had been solved; and (d) the low bidder selected
CPER over the other two materials included in the specifications, 80-mil
high-density polyethylene (HDPE) and 45-mil reinforced chlorosulfonated
polyethylene (RCSPE).
• Alternative linings such as Portland cement concrete and asphaltic con--
crete were considered for use at Mt. Elbert but were rejected due to the
large amounts of aggregate necessary and the schedule, which required
that the liner be installed in one construction season. Asphaltic concrete
would not have provided the desired level of seepage control.
• Rubber sheeting such as butyl and EPDM were not considered for this pro-
ject because USBR personnel were not confident in the manufacturer’s
ability to produce a good quality seam in the material. USBR believes
that the rubber sheeting manufacturers have lagged behind the fabrica-
tors in developing seaming methods for their products.
• PVC was not considered for the project because of the potential for
plasticizer migration and loss and subsequent liner deterioration.
4. Miscellaneous
• Clay and synthetic liners each have a proper role. In locations where
the water table is high and freezing occurs, a soil liner may not be
appropriate because it may be damaged by frost action. There are cases
where an earthen liner is not an option because a suitable soil is not
available. There are also sites where a local soil is suitable and pro-
vides the best seepage control for the price.
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U.S. Bureau of Reclamation
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• Granular covers are recommended for both flexible membrane and cohesion-
less soil liners for protection against erosion (e.g., wave action).
• The USBR has published the results of related studies on the performance
of granular soil covers on canals and the effects of freezing on soil
structures and linings.
0 lity Assurance/Quality Control
• Good quality assurance (QA) is important in soil liner construction.
Some important elements of a good QA program are laboratory tests on
proposed soils, conducting soil density tests for construction control,
compacting soil within two percent of optimum moisture content, and com-
pacting soil to 95 or 98 percent of Proctor test density. The USBR
usually does not perform permeability tests on its installed liners.
• QA is the most important factor in obtaining a good flexible membrane
liner. USBR has had better success than others have with flexible liners
because it has had better factory and installation inspection programs.
• For the Mt. Elbert project, QA was an integral part of each step. USBR
personnel inspected the manufacturer’s and fabricator’s facilities and
operations as well as those of the independent laboratories they hired.
They discussed testing procedures with the manufacturer before testing
began to ensure more compatible test results. The experience and quali-
fications of the laboratories and the installers were carefully considered.
A minimum of five million square feet of installation experience was re-
quired of the installing contractor.
• Every tenth factory blanket of material for Mt. Elbert was thoroughly
tested along an 18-inch width containing all seams and sections from each
panel . Inspectors checked the entire length of each seam in the field
for problems such as delamination, which were marked for subsequent re-
pair by the installation contractor.
• Adhesive field seams were considered the most critical step in the in-
stallation procedure at Mt. Elbert. These field seams were inspected by
monitoring the temperature at which they were seamed, testing them with
a 50 psi air lance, and applying a cap strip of 30-mu CPE.
• The results of the Mt. Elbert testing program show that the seam peel test
is a better test than the shear test. This is because it shows how homo-
geneous the material is and where and when interface failure occurs.
Manufacturers prefer shear tests because the results are more favorable
to the manufacturer.
• Cutout seam samples are more representative of actual seam quality than
are mock seams constructed especially for QA tests and should be included
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Interview No. D-7
U.S. Bureau of Reclamation
Page 6
in QA programs. There is no reason why the patches installed to fill
in where the cutout samples were taken should create a lower quality
liner.
• Coupon programs should be conducted after installation so that liner
performance can be monitored over time. At Mt. Elbert, eleven 4-foot
by 20-foot coupons were buried within the fluctuating water level of
the reservoir. During the first year ofoperation, two coupons were
removed and tested. During the next four years one coupon will be re-
moved and tested each year. If gross failure occurs in the coupons
within the first five years, the manufacturer must replace the liner
(the warranty covers materials and seams for five years; it does not
cover installation). If the coupons do not deteriorate significantly
during the first five years, the interval between testing the remaining
coupons may be lengthened.
• Liner materials should be tested for compatibility with the waste or
liquid in question prior to liner installation. A coupon program should
then be used to monitor performance.
Perspectives on Regulations and Regulatory Reform Needs
• EPA should have some regulations regarding QA procedures because they
are the key to liner longevity.
• Licensing can help in a general way but it does not ensure quality. The
client must develop confidence in his consultants before hiring them by
taking the time to thoroughly inspect their facilities and their expe-
rience record.
• USBR might use a third party for QA/QC activities if they identified a
good consultant. However, they feel that their own personnel have the
expertise to conduct in-house QA/QC programs.
Related Research
• Soviet Union has considerable experience with PE as a buried plastic
lining for use in canals. L.0. Timblin of USBR may be contacted for in-
formation (see reference list).
• Private French companies have been progressive in their use of new mate-
rials such as geotextiles to protect membranes, facilitate installation,
or provide leachate or gas flow channels.
• Earthtech Research Corporation is developing sophisticated seepage de-
tection methods using such tools as sonar and resistivity grids.
• Some research on soil liners for brine disposal and solar ponds is being
performed in Israel.
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U.S. Bureau of Reclamation
Page 7
Research Needs
USBR perceives a need for additional research in the following areas:
• The combination of geotextiles with unreinforced membranes.
• The durability of seams under various conditions.
• The development of methods to evaluate soil liners after placement with-
out violating liner integrity.
• The development of soil liners specifically for brine disposal.
• The use of dispersants to compact soils to higher densities.
Additional Contacts
• Mr. L. Timblin and Mr. W. Morrison of USBR were unavailable at the time
of the meeting and could provide additional information and data on the
joint U.S.IU.S.S.R. program on polymers for canal construction and on
USBR synthetic liner degradation studies, respectively.
References
• L.O. Timblin, Jr. U.S./U.S.S.R. Studies on Polymers for Canal Construc-
tion. Preprint for ASCE Convention, April 1977, Dallas, TX.
• W.R. Morrison, R.K. Frobel, et al. Installation of Flexible Membrane
Lining in Mt. Elbert Forebay Reservoir. U.S. Dept. of Interior, Bureau
of Reclamation, Denver, CO. September 1981. 46 pp.
• C.W. Jones. Summary of Presentation at SERI Workshop on Pond Linings,
Snowmass, CU, Bureau of Reclamation, Denver, CO. August 1981. 11 pp.
• C.W. Jones. What Happened to the Soil Lining in the Salt Ponds’ J
Research News, January 1983, Bureau of Reclamation, Denver, CO. 9 pp.
(Preprint draft).
• C.W. Jones. Soil Linings for Seepage Control. In Parks and Recreation,
February 1968. 3 pp.
• R.K. Frobel. Quality Assurance Program for the Mt. Elbert Forebay
Flexible Membrane Lining Installation. Bureau of Reclamation, Denver,
CO. Proceedings of Water Conference, Paris, 1983. 6 pp.
• R.K. Frobel. ‘A Microcomputer-Based Test Facility for Hydrostatic Stress
Testing of Flexible Membrane Linings. R.K. Frobel, Bureau of Reclama-
tion, Denver, CO. Proceedings of Water Conference, Paris, 1983. 6 pp.
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U.S. Bureau of Reclamation
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• Ground Water Manual. Bureau of Reclamation, Denver, CO, 1981. 480 pp.
• Earth Manual. Bureau of Reclamation, Denver, CU, 1980. 810 pp.
• W.G. Smoak and N.J. Stodoiski. Polymer Impregnation and Collection of
Undisturbed Soil and Rock Samples. Bureau of Reclamation, Denver, CO,
March 1979. 41 pp. -
• 3.1. Dikeou. Fly Ash Increases Resistance of Concrete to Sulfate Attack.
Bureau of Reclamation, Denver, CD, 1981. 17 pp.
• M.E. Hickey. Investigations of Plastic Films for Canal Linings. Bureau
of Reclamation, Denver, CU, 1969. 35 pp.
• W.G. Holtz. Soil as an Engineering Material. Bureau of Reclamation,
Denver, CO, 1974. 45 pp.
• R.E. Glover. Ground-Water Movement. Bureau of Reclamation, Denver, CO.
76 pp.
• W. R. Morrison. Bureau of Reclamation Experiences With Flexible Mem-
brane Linings for Seepage Control in Canals, Reservoirs, and Ponds.
Summary of Presentation at SERI Workshop on Pond Linings, Snowmass, CU,
August 1981. 10 pp.
• Interim Report, U.S./U.S.S.R. Joint Studies on Plastic Films and Soil
Stabilizers, Volume III. Laboratory and Field Studies on Plastic Films
for Hydrotechnical Construction. December 1982.
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ASSESSMENT OF TECHNOLOGY FOR CONSTRUCTING AND
INSTALLING COVER AND BOTTOM LINER SYSTEMS
FOR HAZARDOUS WASTE FACILITIES
EPA Contract No. 68-02-3174; Work Assignment No. 109
INTERVIEW NO. 0-8
Illinois State Geological: Keros Cartwright TRW: Masood Ghasserni
Survey, Urbana, IL 217-333-5113 John F. Metzger
25 January 1983
Summary
• While clay and synthetic membrane liners both have certain merits, clay
should be preferred for hazardous waste land disposal applications
because: (a) much greater confidence can be placed in the long-term
stability of clay which has been around for millions of years; (b) un-
certainty as to the integrity of synthetic liners in long-term service;
(c) established performance of clay liners (largely in-situ clay) in
sanitary landfill applications; and (d) ability of clay to attenuate
pollutant movement.
• Some wastes discharged to landfills can be significantly more hazardous
and present greater long-term threat to the environment than low-level
radioactive wastes. Synthetic liners are not considered viable in
radioactive waste management applications and, hence, should also not
be relied upon for hazardous waste disposal sites which present a much
more difficult case of long-term care and monitoring of pollutants
escaping the disposal site.
• Cases of clay liner failure can be attributed to poor design which has
failed to recognize differences in clay properties under various level
of moisture saturation and to poor installation allowing extremes in
swelling and inappropriate compaction.
• In clay lined systems, the cap should be of a lower permeability than
the bottom liner and the leachate should be allowed to percolate into
the bottom liner. Leachate collection and above-ground treatment for
hazardous waste sites necessitate perpetual care which is impractical.
• A cap consisting of two layers of clay with a gravel layer sandwiched
in between offers good long-term performance. The gravel layer perches
the water in the upper clay layer where it is removed by evapotrarispira-
tion during dry weather conditions. During wet weather conditions, when
the storage capacity of the top layer is exceeded, some of the water is
transmitted to the gravel layer and is drained out and away from the
Si te.
• Areas requiring research and development attention include: (a) identi-
fication and listing of wastes which should be banned from landfills;
(b) soil attenuation studies on specific organic wastes; (c) contaminant
transport in fine grain sediments; and (d) assessment of the validity of
Dorcy’s law at low permeabilities (l07_108 cm/sec).
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Interview No. D-8
Illinois State Geological Survey
Page 2
Background
Dr. Cartwright is a nationally recognized expert on the subject of clay
permeability and has worked on this subject matter for the past 20 years.
Most of Dr. Cartwright’s recent work relates to the design of clay covers for
landfills. The purpose of this interview was to obtain technical informa-
tion and perspectives on the design, adequacy, and performance of clay
liners and caps, and related regulatory considerations and research and de-
velopment needs.
Clay Versus Synthetic Liners
• Except in cases where dramatic failure occurs, it is generally not
certain how well either synthetic or clay liners perform. Neither is
completely adequate.
• EPA’s preference for synthetic membranes (as expressed in the interim
final regulations) probably stems from misinterpretation of Kirk Brown’s
research on clay compatibility with organic solvents. Where a distinc-
tion must be drawn, clay liners which are recompacted to minimize dis-
continuities are probably better. However, the best system is most
likely one using a combination of synthetic and clay liners.
• The following advantages of clay can be cited:
- Materials not indigenous to an area would generally be expected to
have limited long-term durability. Local clays have proven their
stability over a period of millions of years and, therefore, should
be suitable as liner materials (particularly for the cap).
- There is an established record of performance for clay liners, parti-
cularly for in-situ clays underlying sanitary landfills (somewhat
less experience exists in impoundment applications involving inorga-
nic waste liquids).
- Moisture entering a land disposal facility must be removed by allow-
ing it to percolate into the bottom liner and hence to prevent its
build-up and possibly overflow into surface waters. Clay liners
permit leachate to flow out of the facility while attenuating the
noxious constituents of the leachate.
• Inadequate installation practices are responsible for most problems which
have been cited for clay liners. Extremes in swelling, for example,
must be prevented because shrinkage can cause the clay to crack. Also,
clay liners are typically designed by engineers or hydrogeologists who
are familiar primarily with saturated flow when the clay is, in fact,
placed in an unsaturated condition.
• While clay lifts are compacted wet of optimum, somewhat different mois-
ture conditions may exist at a later time. This depends, in part, on
the water content of the waste material and the level of the water table.
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Illinois State Geological Survey
Page 3
Reliance on Attenuation Capacity of Clai
• Removal of leachate from a landfill is not appropriate since this re-
quires perpetual care of the facility and connotates storage of waste
rather than disposal. There are also serious problems concerning what
can be done with collected leachate. Waste stabilization which results
in improving leachate quality occurs at a very slow rate where materials
resistant to degradation are involved. Thus, leachate may have to be
collected for years. The appropriate approach, then, is to eliminate
collection of leachate and design an appropriate clay liner which will
allow leachate percolation and has adequate capacity to absorb and atte-
nuate leachate constituents.
• The landfill cap should be less permeable than the bottom liner to pre-
vent build-up of leachate in the system. Although the needed perm abi-
lit of the bottom liner is site specific, it typically ranges 10’ to
lO cm/s. Clay caps having permeability less than this range, however,
probably cannot be constructed.
• The extent of the zone of attenuation is specific to the site but must
be considered in the design of the facility. For one site located in an
arid western location, the zone of attenuation extended approximately
one mile below the facility. An extension of 30 to 50 feet is more
typical. The attenuation capacity of clay for individual leachate con-
stituents can be established in the laboratory by chromatographic or equi-
valent methods. Certain species such as chloride or calcium/magnesium
(hardness) may be suitable indicator species. Generally, however, the
attenuation of organics, especially in a matrix of many species, is poor-
ly known. Solubility in water can provide some insights, but the com-
plexity of interactions involved is usually so high that no prediction
is adequate. For example, PCBs become mobile not by the water but by
trace amounts of organic solvents in which they are soluble. Once
dissolved, the PCBs may move farther than the main leachate front.
• To lessen the strength of leachate, disposal of liquids into land dis-
posal facilities should, with only a few exceptions, be eliminated. One
approach is to solidify all liquids and sludges before disposal in land-
fills. The potential of various materials to generate leachate varies
(and is often unknown). Thus, waste segregation (according to some
common characteristics) and disposal in separate cells may provide for
better leachate management.
Caps for Land Disposal Facilities
• Caps are difficult to maintain because of constant exposure to stressful
conditions.
- Erosion is a principal stress causing failure of poorly constructed
caps, especially those having clay placed directly on a synthetic
membrane.
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Interview No. D—8
Illinois State Geological Survey
Page 4
- Subsidence occurs in every case although it can be greatly minimized
if moisture is prevented from entering the facility. Where there is
significant consolidation and hence differential settling, precipi-
tation can pond on the cap, thus increasing infiltration. In
Northern Illinois, for example, where there is 30 to 34 inches of
rainfall per year, only 2 percent of this normally reaches the ground-
water. By comparison, infiltration into a poorly designed/constructed
cap can exceed 60 percent.
- An “EPA standard” of a two-foot compacted clay cover is not sufficient
in Northern Illinois to protect it against annual freeze/thaw cycles.
In the winter, the frost line may extend 30 to 40 inches deep.
Another recommendation has been to plant grass on the soil cover for
the cap. This practice minimizes erosion, but by holding water, it
increases infiltration. Compared with a row crop such as corn, in-
filtration with a grass cover may be four to five times higher.
• An appropriate cap system might be a one-foot layer of compacted clay
covered by gravel and/or sand (to protect it against freeze/thaw cycles
and root penetration) and a layer of cover soil. A synthetic liner
combined with clay might also be appropriate, as long as the synthetic
is everywhere covered to protect it from decay.
• A wick-effect cap has been proposed and built in four cases to compare
its performance with modeling studies and to prove that a natural cover
can be built to greatly restrict inflow. The system, which is currently
under evaluation, consists of a permeable gravel layer sandwiched bet-
ween two clay layers. The dramatic change in permeability between the
upper two layers results in some water being perched in the upper layer.
During warm months, evapotranspiration removes much of this water.
During wet months when the storage capacity of the upper layer is ex-
ceeded, it drains into the gravel layer and is routed out of the facili-
ty. This, of course, assumes that any liquid reaching the lower gravel-
clay interface will flow over the top of the bottom liner and not into
it as has been hypothesized by other researchers who consider liquid
film formation necessary for free lateral flow at the interface and
question whether such a film will indeed be formed, given the greater
potential for slow liquid penetration into the bottom clay. The wick-
effect cap is considered a potential long-term solution. It would be
installed after the period of most active subsidence, and when cons-
tructed at least seven feet thick and with a well-developed grass cover,
it should last for 300 to 400 years in the Northern Illinois area.
• Other cap studies are being done (among others) under NRC and EPA
funding at the University of Kentucky, University of Arizona, Los
Alamos Laboratory, USGS, and U.S. Corps of Engineers.
• Land disposal sites can be developed into parkland, including with some
buildings, almost immediately upon closure. This use provides an ex-
cellent mechanism by which to ensure continued institutional interest in
maintaining the site (including cover).
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Interview No. 0-8
Illinois State Geological Survey
Page 5
Perspectives on Regulations
• Many of the regulations/goals proposed for disposal of radioactive wastes,
while more stringent, are appropriate for hazardous wastes as well
(Federal Register, Vol. 47, No. 248, 27 December 1982: Licensing Requi-
rements for Land Disposal of Radioactive Waste - Final Rule). Some
hazardous wastes, particularly organics, are more persistent than low
level radioactive wastes. Additionally,these materials are often very
elusive in the environment, being very difficult to monitor or detect.
By comparison, radioactive wastes are easily detected.
• Some organic materials (such as volatile solvents) are probably un-
suitable for landfilling and should be banned. Some of these are
easily incinerated.
• Materials that are toxic near their detection limits should be disposed
of by a method other than landfilling.
• The review process for land disposal facilities needs to be upgraded.
Regulators should pressure owners, perhaps via establishing performance
standards, to ehminate cost from being the overriding decision-making
variable. Performance standards are practical because movement of
leachate can be predicted and later verified by monitoring wells.
• Other requirements set by regulators could be improved. Data for each
facility should be as complete as practical. In many cases, consulta-
tion with a geological expert may be appropriate and should be required.
Finally, consultants should be forced to write adequate reports. The
entire process of upgrading the design, construction, and operation of
facilities is probably a process that may require an excess of 12 years.
There should also be much better segregation of materials in the landfill
and some should be banned altogether.
• Although perhaps impractical and contrary to the present trend, construc-
tion of more smaller landfills should be promoted over construction of
fewer but very large landfills. With smaller landfills, the chances
that the attenuation capacity of the underlying strata would be exceeded
is less and also damages resulting from a failure would not be as drama-
tic and perhaps could be more readily corrected.
Research and Development Needs
• There is a pressing need to transfer R&D information to field personnel.
Some screening of this information is also needed, since not all develop-
ments are of immediate practical utility and not all information can be
agreed on by key experts.
4-251
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Interview No. D-8
Illinois State Geological Survey
Page 6
• Additional R&D needs are suggested as follows:
- Listing of materials that should be banned from landfilling.
- More clay/natural soils attenuation studies with organic chemicals.
- Assessment of contaminant transport in fine grain sediments, including
in fracture networks (fracture networks are sometimes believed respon-
sible for unexpected movement).
- Studies of the validity of Darcy Law at permeabilities of iO to
10-8 cm/s; also, an investigation of the effective porosity term
used in this relationship.
- Some standardization and survey of methods used to measure design
parameters. These practices may be reasonably good, but the informa-
tion has never been assembled in one location.
Key Contacts
• The following individuals/companies have good field experience with clay
liners and waste disposal site design and operation:
- Warzen Engineering; Madison, WI. Contact: Dan Vista, 608-257-4848.
- Todd Giddings; State College, PA. Has own business installing syn-
thetic liners, but possibly clay as well.
- Environment Resource Management, Inc.; Westchester, PA. Contact:
Ronald Landen, 215-696-9110.
• For access to a well operating clay-lined facility:
- George Hughs; Ontario Ministry of the Environment.
• NRC: David Setfken; Silver Springs, MD. 301-427-4434 or 301-427-4663.
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4.5 INTERVIEW REPORTS WITH TRADE/PROFESSIONAL AND STANDARDS SETTING
ORGANIZATIONS
E-l. American Water Works Association
E—2. Electric Power Research Institute
E-3. National Sanitation Foundation
4-253
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ASSESSMENT OF TECHNOLOGY FOR CONSTRUCTING AND
INSTALLING COVER AND BOTTOM LINER SYSTEMS
FOR HAZARDOUS WASTE FACILITIES
EPA Contract No. 68-02-3174; Work Assignment No. 109
INTERVIEW NO. E-l
American Water Works Association: John Capito TRW: Heather White
Denver, CO George Craft
303—794—7711
15 December 1982
Summary
• AWWA Standards Committee recently completed a draft manual on flexible
tanks, covers, and linings. This Manual will be presented to the
Standards Council for review and approval. The Standards Committee
will now prepare standards on that subject.
• The manual and the standards are to be specifically directed towards
potable water uses, and all sections of them nay not be directly
aoplicable to hazardous ,aste facilities.
• The manual is strictly advisory in nature. It is intended to serve as
a guide for engineers and water utility managers in the design, instal-
lation, operation, and maintenance of facilities utilizing flexible
linings and covers.
• The standards will emphasize materials specifications. Design, instal-
lation, and/or QA/QC could also be addressed in the standards, or could
be addressed in separate standards at a later date.
Background
The American Water Works Association (AWWA) is concerned with various
aspects of potable water supply and quality. Their Committee on Flexible
Tanks, Covers and Linings for Potable Water Reservoirs was formed seven years
ago to develop a manual containing guidelines and recommendations for consi-
deration in the design, installation, operation, and maintenance of facilities
utilizing flexible linings and covers. The ten-member committee recently
completed the draft manual , and has received authorization from the AWWA
Standards Countil to comiience work on a standard which will emphasize potable
water contact requirements for liners and covers. TRW originally contacted
the committee chairman, Fir. Robert Michols, who recommended that for the
purpose of the subject EPA task TRW speak with John Capito, the conmittee’s
coordinator.
4-254
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Interview No. E-l
American Water Works Association
Page 2
Flexible linings and covers might be used in the potable water industry
in the following situations:
• In an earthen reservoir used to store untreated or raw water to minimize
water losses due to seepage and evaporation.
• In an earthen reservoir used to store potable water, both to reduce water
losses and to protect the water from contamination.
• In an existing storage facility (made of steel or concrete or lined with
asphalt) which has developed excessive leakage.
• In an existing open-top facility requiring protection from contamination.
The following is a description of the status and nature of the manual and
standards, and of the process by which AWWA manuals and standards are devel-
oped. Research needs perceived by AWWA and suggested contacts are also pro-
vided.
Status of the Manual and Standards
• The manual has been completed by the committee and will now be reviewed
for approval by the Standards Council*.
• The committee recently received authorization to prepare standards for
the use of flexible membrane covers and linings. The committee will be
expanded for this effort, which may take four to five years.
Nature of the Manual and Standards
• The manual is intended to serve as a guide for engineers and water utili-
ty managers in the design, installation, operation, and maintenance of
facilities utilizing flexible linings and covers.
• The manual is strictly advisory in nature. It is not intended to be a
design handbook or a set of materials specifications. It includes re-
commendations regarding design, installation, operation, and maintenance
of both flexible linings and floating covers. An engineer may choose
whether or not to follow the manual ‘s recommendations.
*
TRW has obtained a copy of the draft manual. The draft covers such aspects of
liner and cover design and installation as climatic considerations, life ex-
pectancy, seaming procedures, leakage, traffic on installed liners, certifica-
tions of manufacturers and/or fabricators as to background experience, dis-
infection of the reservoirs, etc. Although many of the topics covered can
apply (or be extrapolated) to hazardous waste facilities, some will clearly
not apply (e.g., certification of the membrane for potable water use). The
manual will be studied by TRW in some detail and the information from it that
is applicable to hazardous waste facilities will be used in the subject work
assignment for EPA.
4-255
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Interview No. E-l
American Water Works Association
Page 3
• The standards will emphasize materials specifications, although it could
include design, installation, and/or QA/QC procedures as well. These
other considerations could be addressed in separate standards at a later
date instead of in the standards presently under development.
• No effort is made to cross-check AWWA standards with those of other or-
ganizations. However, AWWA standards do refer to American Society of
Testing and Materials (ASTM), National Sanitation Foundation (NSF), and
other standards as appropriate. They attempt not to duplicate other or-
ganizations’ standards and to make them specific to potable water uses
only.
S
NSF standards coordinator Gary Sherlaw has attended the last few meetings
of this AWWA Committee. An AWWA representative is a member of the NSF
Committee and has participated in NSF standards activities. He felt that
NSF’s standard was too broad for the AWWA’s purposes and that a separate,
more narrowly defined standard specifically directed to potable water
uses was appropriate and justified.
• AWWA has no plans to address clay or asphalt lined reservoirs because
there is no need for specific recommendations or standards for potable
water applications. The most closely related item is a relatively old
manual on spillways.
• Both the manual and the standards are oriented towards potable water
applications. They are not intended to address the special concerns of
hazardous waste applications (e.g., waste/liner compatibility). Because
of this, even though portions of the manual and standards could apply to
hazardous waste facilities, it is up to the engineer to decide whether or
not a specific article in the manual or standards applies to the facility
in question.
Development of AWWA Manuals and Standards
• A standard is only developed when there is a recognized need for one,
as pertains to potable water uses. There must be at least two manufac-
turers of the product. Often the manufacturers will request standardi-
zation. The Standards Council must authorize the project and assign it
to a committee.
• All WWA committees are composed of volunteers with expertise in the
subject under consideration by the committee. The committee members
need not be members of AWWA. Manufacturers, consumers (water utility
personnel), and people with general interest in the subject (e.g.,
consultants) may all be on a committee, although manufacturers may
not comprise more than one-third of the committee.
4-2 56
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Interview No. E—l
American Water Works Association
Page 4
• The personal knowledge and practical experience of the comittee mem-
bers, as well as appropriate reference materials and case studies, are
used in developing and supporting a standard or manual. The committee
must meet the product quality needs of the water works industry while
limiting standard requirements to those which are technically justified
and do not unreasonably limit product competition.
• Each comittee meets at least once each year at the annual AWWA conven-
tion. Mid—year meetings may be conducted (and were in the case of this
committee). Much of a committee’s work is conducted via correspondence.
• Decisions are made by consensus of the committee. This applies to the
contents of a manual as well as the specifications of a standard.
• A standard is approved only after it has passed six review levels:
- The committee votes on the standard.
- The AWWA Standards Council votes on it by letter ballot. The twenty
council members are all consumers or those with a general interest
in the subject matter; no manufacturers are on the council. Many
council members have experts on their staff review the standard.
- A notice of Standard Council action is published in AWWA’s newsletter,
Mainstream , to begin a 30 day public comment period. If an appeal is
received during the 30 day comment period, then Standard Council ac-
tion is suspended until the appeal is resolved.
- The AWWA Board of Directors votes on the standard.
• The American National Standards Institute (ANSI) conducts a 60 day public
review of the standard prior to their adoption of the standard as an
American National Standard. This 60 day review may be concurrent with
AWWA’s 30 day public comment period.
• A manual undergoes only the first two of the above review levels. After
it has been approved by the committee and the Standards Council, it is
published and offered for sale.
Research Needs
• In keeping with their concern for potable water, AWWA is interested in
seeing more research in the following areas:
- The interactions of liners and water and the possibility of decreases
in water quality (due to toxic substances entering the water, etc.).
- The potential for groundwater contamination due to waste or leachate
seepage from land disposal facilities, which could result from adverse
reactions between wastes and liners.
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Interview No. E-l
American Water Works Association
Page 5
- Environmental effects (e.g., sunlight, smoy, acid rain, rodents) on
floating covers.
Suggested Contacts
Robert L. Nichols, Partner, Freese & Nichols, Fort Worth, TX, is chairman
of the Standards Committee on flexible reservoir covers and linings for potable
water storage and may be able to suggest additional contacts or provide refer-
ence material.
4-2 58
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ASSESSMENT OF TECHNOLOGY FOR CONSTRUCTING AND
INSTALLING COVER AND BOTTOM LINER SYSTEMS
FOR HAZARDOUS WASTE FACILITIES
EPA Contract No. 68-02-3174; Work Assignment No. 109
INTERVIEW NO. E-2
Electric Power Research Institute: Dean Golden TRW: Louis L. Scinto
Palo Alto, CA 415—855-2516
17 December 1982
Summary
• Clay liners have their place in utility waste disposal applications
since in the lonq term, they provide waste attenuation rather than
“interim” containment.
• EPRI has simple hydrologic models for predicting leachate migration from
landfills, but it will take 3-5 years to incorporate into the models
laboratory data on soil attenuation of specific constituents.
• Although not directly affected by the July 1982 hazardous waste regula-
tions (because utility coal combustion wastes are not hazardous wastes),
the electric power industry is finding that states tend to apply many
of the provisions of EPA’s hazardous .iaste regulations to non-hazardous
waste disposal facilities.
• EPA or the states should provide on-site inspectors during liner instal-
lations to ensure the quality of the work.
• Completed, on-going, and planned EPRI activities relevant to the subject
program are identified.
Background
Mr. Golden is Manager of Solids By-Products and Hazardous Waste Disposal
in the Coal Combustion Systems Division of the Electric Power Research Insti-
tute (EPRI). The objectives of this interview were to obtain information on:
(a) completed, on-going, and future work by (or for) EPRI which might have
bearing on the subject effort for EPA; and (b) Mr. Golden’s views on the re-
gulation of waste disposal facilities. A number of reports and project sum-
maries were received during the interview which have not yet been reviewed by
TRW. Results of these reviews will be incorporated into TRW’s final report.
Relevant EPRI Activities
• RP1457-l: Liner Evaluation (Matrecon, Inc.). This on-going project is
primarily an experimental program in which selected liner materials are
exposed to actual wastes from coal-fired power plants for extended pe-
riods under conditions which simulate some of those that exist in actual
facilities. The objectives are to determine liner/waste compatibility,
4-259
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Interview No. E-2
Electric Power Research Institute
Page 2
durability, and cost-effectiveness, arid to estimate effective lives of
various liner materials in specific applications. Also as part of the
project, surveys were conducted of the open literature, of synthetic
liner manufacturers, and of selected users to determine the state—of—
the-art in liner use and groundwater monitoring at utility disposal
sites.
• RP14O6-l: Groundwater Mathematical Model, Battelle Northwest. A model
was developed for predicting the quality and quantity of leachate and
its migration path from a sludge/fly ash disposal site. A model data
base and results of laboratory studies were used to implement, calibrate,
and verify a two-dimensional, finite difference hydrologic flow model for
the study area. The saturated flow model was developed in 1980 and in
1981 a new model incorporating unsaturated flow conditions was developed
and linked with the original model. Beginning in 1983, laboratory stu-
dies will begin (under RP 2198 of Environmental Assessment Department)
to determine soil attenuation properties which could be incorporated into
the model in 3-5 years.
• RP1685: By-Product Disposal Manuals - Manual for Upgrading Existing
Disposal Facilities, SCS Engineers. This manual, published in August
1982 as CS-2557, provides a description of current disposal systems and
where they may be deficient compared to EPA criteria, and what remedial
measures can be taken when necessary to bring existing systems up to
standard. A discussion of liner and leachate collection system instal—
lation is included in the document.
• RP126O-9: Evaluation of Levels for Solid Waste Disposal Areas, Hydra-
comp, Inc. During this study, 5 1 coal-fired power plants were located
relative to floodplains. Of these sites, only 109 were definitely out-
side the 100-year floodplain. The report also assesses the Federal
Insurance Administration (FIA) methods of flood mapping, which may be
used to enforce potential EPA regulations concerning facility locations.
Major issues and concerns regarding use of FIA maps/methods for enforce-
ment of regulations are pointed out. This report was published in
October 1979 as FP-l205.
Views on Regulations and Relevant Activities
• One of the concerns of the electric utility industry is that states will
adopt regulations for non-hazardous waste facilities that are as strin-
gent as EPA’s new regulations for hazardous waste sites. In fact,
three states have already adopted regulations that are more stringent
than EPA’s rules. The industry believes clay liners are suitable for
some wastes produced by coal-fired power plants; however, some low
volume waste streams may require disposal as hazardous wastes, for
example, because of their toxicity. Radian Corp. is studying management
options for these low volume wastes as part of RP2215.
4-260
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Interview No. E-2
Electric Power Research Institute
Page 3
• Michael Baker, Jr. Inc. has prepared for EPRI engineering and economic
assessments of how EPA regulations may affect the electric utility in-
dustry. Their assessment of the impact of the July 26 regulations is
due to be published in May 1983.
4-261
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ASSESSMENT OF TECHNOLOGY FOR CONSTRUCTING AND
INSTALLING COVER AND BOTTOM LINER SYSTEMS
FOR HAZARDOUS WASTE FACILITTES
EPA Contract No. 68-02-3174; Work Assignment No. 109
INTERVIEW NO. E-3
National Sanitation Foundation: Gary Sherlaw TRW: Masood Ghassemi
Ann Arbor, MI 313—769-8010 John F. Metzger
28 January 1983
Summary
• Voluntary standards being developed by NSF from the combined input of
liner manufacturers/fabricators, regulators, and users can assure the
quality of materials used to line land disposal facilities.
• NSF efforts to develop liner standards have been on-going since January
1978. The work is nearing completion as another set of objections has
been addressed and another ballot is currently circulating. The stan-
dards could conceivably be in place by mid-year.
• Accreditation of field installers at the foreman level could be an
effective means of ensuring better quality control during field instal-
lation.
• Research and development should emphasize development of “accelerated”
performance tests which can simulate 25 or more years of service within
a short time frame of a laboratory or field test.
Background
National Sanitation Foundation (NSF) is a nonprofit corporation that
develops voluntary standards in selected public health and environmental
areas. There are three formal service areas: listing, certification, and
assessment. Listing services include standards development and list pro-
ducts meeting the standards developed by NSF. Certification services are
similar to listing services but the standard against which a product is
tested has been developed by someone other than NSF. Assessment services
encompass special studies and service, including research, demonstration,
and protocol development.
The objectives of the NSF standards development program is to assure
that standards are developed based on facts, not curbstone opinion. To
meet this objective, existinc knowledge, both published and unpublished,
is consulted; and new research is conducted when necessary. During this
process NSF works to develop a mutual understandinq between manufacturers
of the products involved, the users of those products, regulatory officials
4-262
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Interview No. E-3
National Sanitation Foundation
Page 2
concerned with the products’ performance and the general public. The ulti-
mate purpose of these efforts is to provide a mechanism for cooperative
action by these groups which will lead to uniform national voluntary con-
sensus standards in the area of concern. NSF standards development program
is entirely voluntary and involves the active cooperation of the manufac-
turer, the user and the regulatory officials charged with rendering deci-
sions concerning the products involved. The NSF’s staff function is entirely
that of coordination and liaison between these groups in an effort to promote
mutual understanding to obtain improvement in the public and environmental
health of the nation.
NSF is in the process of developing a standard for the flexible membrane
liner industry. The purpose of the interview was to determine the status and
significance of this standard and the process by which it is developed.
Impetus For and General Procedures For Developing Standards at NSF
• The impetus for developing standards can come from industry, from public
health agencies or from the consumer. The Foundation determines the
need for the development of new standards by meeting with industry and
professional public and environmental health groups. The need can also
be determined through discussions held at clinics and at public health
and environmental congresses. Once the need has been established, the
necessary committee framework for the specific standards area is put in
place. Basically, it involves a joint comittee which has overall juris-
diction during the development phase of the project and, if indicated,
a task committee to assist in writing the standard.
• Participation on a joint committee is by invitation. Each organization,
public or private, involved in the standard under consideration appoints
its own representative. Representation from the manufacturing sector is
broad and unrestricted in attendance. Military and civilian U.S. govern-
ment agencies send professional representatives. The consumer may be
represented by individuals or by special consumer groups, if available,
or by government or-military personnel.
• The NSF professional staff coordinates the activity, provides secretarial
services and acts as liaison between the joint committee and the task
committees. Meetings are structured to allow the maximum flexibility for
free and wide ranging discussion. The joint committee is chaired by an
individual selected from the current, or past, membership of the NSF
Council of Public Health Consultants. Usually, the person selected is
one having experience or expertise in the standards area involved.
• Once hearings have been held and necessary research conducted, the NSF
staff brings together the reports and recommendations from the joint com-
mittee and the task committees, and the draft of a proposed standard is
prepared. The joint committee then meets to consider the preliminary
4-263
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Interview No. E-3
National Sanitation Foundation
Page 3
draft of the proposed standards. At this point, the joint committee
may approve the proposed standard or criteria, so that it can be sub-
mitted to the NSF Council of Public Health Consultants. On the other
hand, it may refer specific items back to the task committee for
further study. It may ask the task committee to clarify points, re-
vise or otherwise modify the draft. In some cases the joint committee
may call in special advisory groups or consultants. The joint com-
mittee may also reject the draft. Should this occur, the entire
subject is reworked by the appropriate task committee and resubmitted
to the joint committee for reconsideration.
• Once approval is obtained, the final draft of the proposed standard is
endorsed by the joint committee before being sent to the NSF Council
of Public Health Consultants. The Council of Public Health Consultants
determines if the standard is adequate to the protection of the environ-
ment and public’s health. If so, the Council will recommend its adop-
tion by the NSF Board of Trustees. If this is not the case, the Council
will refer it back to the joint committee for further work. Once objec-
tions, if any, are clarified, the NSF Board of Trustees adopts the stan-
dard, at which point the standard is published and distributed to public
health agencies, manufacturers and users.
• Acopyofan 19SF publication describing NSF policies relating to the use
of NSF seals by manufacturers on the products covered by a published
NSF standard is attached.
• Industry supports the standards development effort with a one-time fee
which is currently $1,260 per company. This money is used primarily to
cover the cost of travel of regulatory people, for whom out of state
travel is usually not paid for in their work. In the future, the fee
structure may be modified somewhat to better reflect the incurred costs.
NSF’s overall operations are financed by test program fees and annual
inspection fees, and government grants and contracts.
• A membership list of the NSF Joint Committee for flexible membrane
liners, industry representatives inputting the NSF standards development
effort, and individuals/organizations receiving courtesy copies of
various drafts is attached to this summary.
Status of the Synthetic Liner Standards and Perspectives on Their Development
• NSF work on the development of synthetic liner standards has been on-
going since January 1978.
• A consensus of 90 percent is needed to move the draft standards out of
the joint committee; currently there is 77 percent approval. To get the
remaining votes needed, objections must be reviewed along with supporting
data to determine if changes are warranted. If all pieces fall together
soon, the standards could be in place by mid-year.
4-264
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Interview No. E-3
National Sanitation Foundation
Page 4
• Although NSF standards will only address the liner quality, it will in-
clude, as attachments to the standards, recommendations on practices
in related areas (e.g., liner installation). These recommendations are
included in the standard to provide useful information to concerned
regulatory officials and users.
• NSF standards require a mandatory review every five years. Due to the
rapid development occurring in the synthetic liner industry, more
frequent reviews may be necessary. Some standards that have been de-
veloped by NSF in other areas were reviewed annually after issue.
Importance of Liner Standards
• The standards under development apply only to manufacturers and fabrica-
tors of synthetic liners; however, input is given by material suppliers,
installers, and regulators (see listings attached) to ensure their full
acceptance.
• The main value of standards is the acceptance of procedures and mate-
rials by an independent third party by criteria that has been agreed to
by all parties in the industry. This probably results in an improved
functioning and higher level of product quality by the entire industry.
• The standards program is fully voluntary, but most of the major manufac-
turers and fabricators are probably participating along with a smaller
representation of installers. Once the standards are in place, those
who do not subscribe to the program will not necessarily be pushed out
of the market. This will depend on how the standards are applied by
concerned regulatory officials and users/consumers.
• NSF has no enforcement power. Its relationship to listed companies is
largely contractual. The main leverage that can be applied to companies
who will be in the program but not abiding by the NSF policies is to
drop that company or its product from the listing.
QA/QC for Liner Installation
• Once the standards are in place, the feasibility of a program to accre-
didate installers will be investigated by NSF, particularly with regard
to construction of field seams. Such a program should extend only to
the level of field foremen as it is impractical to require accreditation
of individual field workers. Implementation of such an accreditation
program would provide for significant improvements in quality control
during installation.
• It is not feasible to develop standards for clay liners because the qua-
lity of material is almost completely dependent on the specific applica-
tion and site. Even with synthetic liners, no attempt is made in the stan-
dards to ensure adequate installation; only the material quality is
addressed.
4—265
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Interview No. E-3
National Sanitation Foundation
Page 5
Research and Development Needs
• Research is needed to develop performance tests that can be made in the
laboratory and that correlate well with field experience. All areas of
liner performance need to be addressed in this way, but especially acce-
lerated tests that compact 25 years or more of service into a short
period of laboratory tests.
Additional Contacts
The list of individuals/organizations in the lining industry which TRW
has interviewed or plans to interview should be expanded to include at least
the following industry experts (which also include representation of the
practices in the Northeastern part of the U.S.):
• Charles E. Staff; Staff Industries; Upper Montclair, NJ.
• Richard Ward; B.F. Goodrich Company; Marietta, OH.
• Richard Dickinson; Dynamit Nobel of America; Rockleigh, NJ.
• Larry Kamp; The Pantasote Company of New York, Inc.; Passaic, NJ.
• Arnold Peterson; Stevens Elastomeric and Plastic Products; East
Hampton, MA.
4-266
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‘.ddL1onaf Saiiiiatioii Foundation
147S i ’tyiuouih
It) flu,. i4( i4
, i it Arbor, Mi ,.hi ,u ii It I) ,
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NATiONAL SANITATION FOUNDATION
POUCIES RELATING TO THE USE OF NSF SEALS
AS REVISED NOVEMBER 1977
As a pubht. service, the National Sanitation Foundation offers to any reputable rnanutactuie tte US C Ut (tie
NSF seal upon formally listed products subject to the following conditions and stipulations
1 Any company, after it has determined that its products are covered by a published NSF standard or
criteria may apply for evaluation and listing by National Sanitation Foundation (NSF)
2 Each manufacturer who desires the use of the NSF seal must file with NSF an “Application for
Evaluation, Testing and Listing Services “ This application shall contain an affidavit, signed by the manufac’
turer, certifying that if said company is authorized the use of the NSF seal, the seal will be placed only on new
products fully complying with the NSF standards or criteria, only at the authorized point of production, and
that said company will abide by the “Policies Relating to the Use of NSF Seals.”
3 Evaluation ai’id/or testing of any product which a company desires to have listed shall be made by NSF
Authorization to use the NSF seal upon such products shall not be granted until evidence has been furnished
the Senior Vice President of NSF that the product meets the standards or criteria
4 Evaluation of products may be made in the applicant’s manufacturing plant, at a site acceptable to NSF
or at NSF
S By authority of the Board of Directors, the Senior Vice Pi esidentor other Corporate Officer, of NSF may
authorize the listing of products as eligible for the NSF seal The manufacturer will be advised of such listing in
writing, and the listing will be made public Equipment listed by model number shalt bear a permanent type
plate or label stating said model designation.
6 The observance of the requirements of the standard by a manufacturer is one of the i..onditions of the
continued listing of the manufacturer’s product NSF. however, assumes no responsibility for the effect of
such observance or nonobservance by the manufacturer upon the relations between the manufacturer and
any other party or parties arising out of the sale or use of the product or otherwise
7 Evaluation and/or testing by NSF of all items or products produced during any listing period is
impractical It is therefore the responsibility of each manufacturer who is granted authorization to use the NSF
seal to place the NSF seal only on new equipment or products fully complying with NSF standards or criteria
A manufacturer may not use the same model number on NSF listed and “non” NSF listed products Further it
is understood that only products bearing the beat shall be considered as listed
8 By authority of the Board of Directors, the Senior Vice President or other Corporate Officer, of NSF
reserves the right to withd,aw the listing of any item at any time for failure to comply with the standard and
attendant policies Upon notice of the removal of a product from NSF listing, the inanutactutet shall im-
mediately stop applying the NSF seal to such products.
9 Variations or alternates in material design, construction or opeiat lon requirements of e’.iahlished NSF-
standards or criteria shall be approved by NSF prior to adoption and use by the rodoufactuler Such variations
or alternates shall be approved only when they have een evaluated and found to be fully equal to or better
than, the material, design, construction or operation requirements of the applicable NSF standards or c,ittiria
and conform to the minimum requirements thereof.
4-267
AD-40 GNA-1O1 1 i i
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10. It is fully understood that NSF will conduct unannounced visits to production facilities for the evaluation
of listed products. Such product evaluations shall be made as determined necessary by the Senior Vice
President of NSF.
11 Whenever a product which is listed by model number or which bears the NSF seal is found by NSF to be
in noncompliance with the requirements of the applicable NSF standard or criteria, the manulacturer thereof
shall immediately effect correction of all future production in said regard, and shall effect correction of said
violations on the specific product found in noncompliance. Corrective action(s) shall be carried Out within
such reasonable time as is established by NSF.
12 When after receipt of satisfactory evidence of correction of reported violations, subsequent evaluations
of the products (future production or the specific product in question) indicate that the corrective measures
have not been, or are not being effected, the authorization to use the NSF seal on said model or equipment or
by the manufacturer, whichever is deemed appropriate by NSF, shall be withdrawn. When authorization to
use the NSF seal has been withdrawn from a manufacturer under the above provisions, NSF may advise such
health agencies, manufacturers and other interested parties as deemed appropriate.
13 Reinstatement following withdrawal of listing and authorization to use the NSF seal by the manufac-
turer, or on specific products, shall be effected only after re-evaluation of the product in question by NSF. The
cost of re-evaluation shall be subject to such charges as are established by NSF.
14 Minimum charges will be made for services These service charges ;uver cost of standards develop-
ment, inspection at the company’s facilities, printing and distribution of listing, and administiative piocoss-
ing. Service charges will start at the date of execution of application for evaluation and listing service by the
company Services of NSF will be available to the company; it will be the company’s responsibility to avail
itself of these services within the period specified in the application. In the case of a company who does not
avail itself of services, the monies paid upon the application will be considered expended during the period
specified in the application Additional service charges may be rendered for special field evaluations and
investigations of listed products found not to be in compliance with the applicable NSF standards or criteria
Any deletion in evaluationilistirig services or testing must be communicated to NSF within 30 days of the date
of the annual invoice or the charges shall be due and payable as stated Further, all costs incurred by NSF in
collection thereof shall be charged to and paid by the firm invoiced.
15 The cost of evaluation and testing of products sent to NSF as well as any required special testing at the
plant shall be subject to charges to be agreed upon between the applicant and NSF
16. The NSF seals in the established form used by the company shall be purchased fiom the approved
source on orders forwarded through NSF for approval.
17. The manufacturer hereby holds NSF harmless and agrees to indemnify it against any and all claims,
causes of action or lawsuits arising from the use of the seal, including but not limited to costs and attorney’s
fees attendant thereto
18 NSF will use every legal means available to prevent unauthorized use of the seal on unlisted items or on
listed items found to be substandard. The manufacturer agrees to be sued in either the State of his principal
place of business or the State of Michigan for failure to comply with any of the terms of this contract including,
but not limited to, payment of fees due to National Sanitation Foundation or National Sanitation Foundation
Testing Laboratory.
4-268
AU 40-CNA ;uLi 04d2
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NSF JOINT COMMITTEE
FOR
FLEXIBLE MEMBRANE LINERS
Chairman, Gray, Melville W., Chief Engineer and Director, Environmental Health Division. State Depart-
ment of Health, Forbes AFB!BIdg. 740. Topeka, KS 66620. 913-862-9360
Aither, George R., Foundry Products Division, International Minerals and Chemicals Corp., 17350 Ryan
Road, Detroit, Ml 48212 (Liaison, ASTM D34)
Fogg, Charles, Soil Conservation Service, U. S. Department of Agnculture, 5248 South Ag ’iculture
Budding, P. 0. Box 2890, Washington, DC 20013
Geswein, Allen, U. S. Environmental Protection Agency (WH564), 401 M Street SW, Washington, DC
20460, 202-755-9125
Giroud, Jean-Pierre, Director. Geotextiles and Geomambranes Group, Woodward-Clyde Consultants, 11
East Adams, Suite 1500, Chicago, IL 60603, 312-939-1000 (Liaison, ASTM D18.20)
Golden, Dean M., Project Manager. Solids By-Product & Hazardous Waste Disposal Subprogram,
Electric Power Research Institute, P. 0. Box 10412, Palo Alto, CA 94303
Hi9hfilI, Gene, Soil Conservation Service, U. S. Department of Agriculture, P. 0. Box 2890, 5248 South
Agriculture Building, Washington, DC 20013
Kinredge, David, Manchester Water Works, 281 Lincoln Street, Manchester, NH 03102 (American Water
Works Association)
Landreth, Robert E., Sanitary Engineer, U. S. Environmental Protection Agency, National Environmental
Research Center, Cincinnati, OH 45268, 513-684-7871
Newell, Edward L., Jr., US Army Environmental Hygiene Agency, ATTN:HSE-E$, Aberdeen Proving
Ground, MD 21010, 301-671-2024
Pacey, John G., President, EMCOM Associates, 90 Archer Street, San Jose, CA 95112 (American Society
for Civil Engineering)
Pohiand, Dr. FrederickG., Department of Civil Engineering, Georgia lnst4tute of Technology, Atlanta, GA
30332, 404-894-2265 (American Society of Civil Engineering)
Powitz, Dr. Robert W., Wayne State University, 625 Mullen, Detroit, Ml 48226, 313-668-1876, office
phone: 313-923-5700 (National Environmental Health Association)
Sytron, C. A., Ill, Research Civil Engineer, Material Development Division, Geotechnical Laboratory,
Department of the Army, Waterway Experiment Station, Corps of Engineers, P. 0. Box 631,
Vicksburg, MS 39180
Timblin, L. 0., Jr., Chief, Applied Sciences Branch, U. S. Department of the Interior, Water and Power
Resources Service, Code D-1520, P. 0. Box 25007, Denver, CO 80225, 303-234-4449
May 1982
4-269
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INDUSTRY
Baseden, Tod, E.I. du Pont Co., Elastomers Lab,Chestnut Run, Wilmington, DE 19898, 302-999-2420
Blatt, John M., President, Pacific Lining Company Inc., P. 0. Box 35, Stanton, CA 90680, 714-891-5481
Cain, Richard, President, Palco Linings, Inc., 7571 Santa Rita Circle. Stanton, CA 90680, 714-898-0867
Crepeau, Allen, Uniroyal Chemical,Technical Sales, Service Center, Spencer Street, Building 112,
Naugatuck, CT 06770, 203-723-3825
Dickinson,Richard,MarketingManager, Dynamit Nobel of America, Fun Sheeting Dept., —
10 Link Drive, RockleiQh, NJ 07647, 201—767-1660
Gish, Brian, Carlisle Tire & Rubber Co., P. 0. Box 99, Carlisle, PA 17013, 717-249-1000
Kamp, Larry, The Pantasote Company of New York, Inc., 26 Jefferson Street. Passaic, NJ 07055,
201 -777-8500
Kutnewsky, 0., Vice President, Burke Industries, Inc., 2250 South Tenth Street, San Jose, CA 95112.
408-297-3500
Lussier, Paul W., Supervisor R&D. Canadian General-Tower Ltd., P. O.Box 160. Cambridge, Ontario,
Canada N1R 517, 519-623-1630 -
Magrans, Juan, Marketing Department, Hercules Incorporated, 910 Market Street, Wilmington, DE
19899, 302-575-5000
Main, Buster, Maineline Sales Company, Inc., 3292 South Highway 97, Redmond, OR 97756
Peterson, Arnold G., Stevens Elastomeric and Plastics Products, P.O. Box 431, Easthampton, MA 01027,
413-527-0700
Pezzoli, Paul A., Dow Chemical Co., Building 2307. Box 150, Plaquemine, LA 70764, 504-389-8275
Pomeroy. John, Tenneco Chemicals, 300 Needham Street, Newton Upper Falts. MA 02164,617-969-6000
Ross, Bert. R & 0. Reeves Brothers, Inc., P.O. Box 26596, Charlotte, NC 28213, 704-563-0544
Salberg, G. W, Synflex Industries, Inc., 301-255 1st Street West, Vancouver, BC, Canada V7M 3G8
Schmidt, Richard, Gundle Lining Systems, Inc.. 1340 East Richey Road, Houston,TX 77073,713-443-8564
Shackleton, John, Technical Advisor, Product & Applications Division, Polysar Limited, Sarnia, Ontario,
Canada N7T 7M2, 519-337-8251
Silverman, Alfred, President, Spartan-Aqualon Corp., 17 Cotters Lane, East Brunswick, NJ 28816, 201-
238-5100
Slifer, William J. Ill, Vice Presdient, Watersaver Company, Inc., 5870 East 56th Avenue, Commerce City,
CO 80022, 303-623-4111
Sparks, Hay F., Jr., Milliken & Company, P. O.Box 1926, Spartanburg, SC 29304, 803-573-2996
Staff, Charles E., President, Staff Industries, 78 Dryden Road, P. 0. Box 797, Upper Montclair, NJ 07043,
201 -744-5367
4—270
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Vandervoort, John, Schlegel Area Sealing Systems, Inc., 200 South Trade Center Parkway P. 0. Box
7730, The Woodlands, TX 77380, 713-273-3066
Ward, Richard, B F Goodrich Company, Box 657, Marietta, OH 45750, 614-373-6611
Watson, Jack, Rutland Plastics Inc., 610 Minuet Lane, P. 0. Box 11007, Charlotte, NC 28209 (Shelter-Rite),
704-523-7125
July 1982
COURTESY COPIES
Ahlquist, Nancy J., DNR Library/2, WI Department of Natural Resources, P. O.Box 7921, Madison, WI
53707
Anderson,Bruce, Chemist-in-Charge, Acmil Plastics, 2 Victor Road, Bentleigh, Victoria, Australia 3204
Au, Paul, Paul A Engineers, Room 701, Aurora House, 57-59 Connaught Road C, Hong Kong
Barbier, James I., Designed Products Department, Dow Chemical Co., 2040 Dow Center, Midland, MI
48640
Boyes, R.G.H, Special Geotechnical Consultant, Hill Brown, 61 Medstead Road, Beech, Alton, Hants
GLJ344AE, England
Brookman, Robert, Ph.D., Pantasote Company, 28 Jefferson Street, Passaic, NJ 07055, 201-777-8500
Bryan. James, Watersver Company, Inc., 5870 East 56th Avenue, Commerce City, CO 80022, 303-623-
4111
Campbell, Dr Ewen,Technical Director,Tenneco Chemicals, Nixon Lane, Nixon, NJ 08818
Cavanaugh, Gordon, U. S. Department of Agriculture, Farmers Home Administration, Washington, DC
20250
Chmiel, Dr. Chester 1., Uniroyal, Inc., 1312 N. Hill Street, Mishawaka, IN 46544, 219-256-8174
Christie, William F, Stauffer Chemical Co., 4407 South Broad Street, Yardville, NJ 08620
Combs, William D., Water & Sewage Works, 66 Griswold Stret, Delaware, OH 43015, 614-369-6312
Edesess, Mike, Solar Energy Research Institute, 1617 Cole Boulevard, Golden, CO 80401
Ferguson, Buell M , Director, Engineering Division, U. S. Department of Agriculture, Soil Conserviation
Service, P. 0. Box 2890, Washington, DC 20013
Fishbein, Leon (Dr.), Thermoplastics Division, Borden Chemical Co., 511 Lancaster Street, Leominster,
MA 01453
Fisher, Gerry E., 3245 Sunnyside Avenue, Brookfield, IL 60513
4-271
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Forseth, Jim, Bureau of Solid Waste Management, WI Department of Natural Resources,Box 7921,
Madison, WI 53707
Freeman, Cathie, National Spa and Pool Institute, 2000 K Street, NW, Washington, DC 20006
Geoffrey. Richard R., Springborn Laboratoiies, Inc., Water Street, Enfield, CT 06082, 203-749-8371
Gerliczy, George, Solvay America Corp., 609 5th Avenue, New York, NY 10017, 212-838-8563
Goss, Alan, Golber Associates, 10628 NE 38th Place, Kirkland, WA 033, 206-827-0777
Grisemer, Charles H Chevron USA, P. 0. Box 96, North Bend, OH 45052
Group, Dr Edward F., Jr., Exxon Chemical Co.. P. 0. Box 241, Baton Rouge, LA 70821, 504-359-4753
Gundle, Clifford J., Executive Chairman, Gundle Plastics (Pty) Ltd., P. 0. Box 5173, Johannesburg 2000,
South Africa
Gurian, Martin, Market Development Manager, Burlington Industrial Fabrics, Link Drive, Rockleigh, NJ
07647
Hamilton, Lorne M., Market Manager, Nonwoven Products, Bay Mills Limits, Bayex Division, 365 Evans
Avenue, Toronto, Ontario M8Z 1K2
Hanrahan, Lynne, Dow Chemical Co., Building 2307, Box 150, Plaquemine, LA 70764, 504-389-8275
Haxo, Henry Dr., Metrecon Inc., P. 0. Box 24075, Oakland, CA 94623
Hess, George M , National Sales Manager, Stauffer Chemical Company, 1 Metro Plaza, Edison, NJ 08817,
201 -540-6880
Hodgson, Bob, Kohkoku USA, Inc., P. 0. Box 2287, Everett, WA 98203
Horvat, Man, Aqua Pure Labs, Inc., 602 Airport Boulevard, Doylestown, PA 18901, 215-345-6349
Kauder, Otto, (Dr.), Argus Chemical Corporation, 633 Court Street, Brooklyn, NY 11231
Kayes, Mary Jane, Librarian, Residuals Management Technology, Inc., 1406 East Washington Avenue,
Suite 124, Madison,Wl 53703
Kerr, Robert N., Jr., Project Manager, Commercial Development, Hooker Chemical & Plastics Corp., PVC
Fabricated Products Division, P. 0. Box 699, Pottstown, PA 19464
Ku, Shirley, Solid Waste Management, 6285 Barfield Road, Atlanta, GA 30328, 404-256-9800
Knudson, Jim, Department of Ecology, Mail Stop PV-11, Olympia, WA 98504, 206-753-4267
Lamson, Robert, American Water Works Association, 6666 West Quincy, Denver, CO 80235
Gray, Ken, Product Manager, Environmental Products, Department 1914 Building WHB-3, B.F. Good-
rich, 500 South Main Street, Akron, OH 44318
Lewis, Bob, Ventron, 7660 Chestnut Drive, Orland Park, IL 60462, 312-532-2819
4-272
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Lightsey, Dr. George, Department of Chemical Engineering, Mississippi State University, P. 0. Box CN,
Mississippi State, MS 39762, 601-325-2480
McCrady, Frank, Vernon Plastics Company, Division of Borden, Shelley Road, Haverill, MA 01830
McCullough, Danny Joe, MWM Contracting Corp., 2359 Avon Industrial Drive, Auburn Heights. M l 48057
Meader, Arthur, Chevron Research Co., 576 Standard Avenue, Richmond, CA 94802
Nichols, Robert L, Freese and Nichols, Inc., 811 Lamar Street, Fort Worth, TX 76102, 817-336-7161
Owen, John W. National Seal Co., 7701 E. Kellogg, Wichita, KS 67207
!‘atterson, Betty, Sales Manager, Shelter-Rite, P. 0. Box 331, Mi llersburg, OH 44654
Perslow, Johan, Pacific Lining Company, Inc.. P. 0. Drawer GGGG, Indio, CA 92201
Rosen, I K., Ken Rosett Associates, 191 Albemarle Road, White Plaines, NY 10605, 914, 949-5948
Sarver, Glen, Technical Manager, B. F Goodrich Company, Box 657, Marietta, OH 45750, 614-373-6611
Schwartz, Jerry, Waste Age, 16 Pettit Drive, Dix Hills, NY 11746, 516-421-5577
4—273
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