United States
Environmental Protection
Agency
Research and Develo ament
ve/EPA Project Summary
Hazardous Waste Engineering
Research Laboratory
Cincinnati OH 45268
EPA/600/S9-85/013 July 1985
Land Disposal of Hazardous
Waste: Proceedings of the
Eleventh Annual Research
Symposium
Donna A. Zunt and Naomi P. Barkley
Proceedings are summarized for Ses-
sion A of the U.S. Environmental Pro-
tection Agency's (EPA's) Eleventh An-
nual Research Symposium - Land
Disposal, Remedial Action, Incinera-
tion, and Treatment of Hazardous
Waste. The symposium was held in
Cincinnati, Ohio April 29 through May 1,
1985. Session A, Hazardous Waste Land
Disposal, included 35 papers; and Ses-
sion C included 20 poster presentations
about the status of research projects
sponsored by EPA's Land Pollution
Control Division (LPCD) of the Haz-
ardous Waste Engineering Research
Laboratory (HWERL). Land Disposal pa-
pers are presented in the areas of reme-
dial action, pollutant assessment, and
pollutant control. They discuss the gen-
eration, movement, control, and treat-
ment of pollutants in landfills, surface
impoundments, air, underground
mines, and uncontrolled remedial ac-
tion hazardous waste sites. Session B,
Hazardous Waste Incineration and
Treatment, will be published as a sepa-
rate document.
This Project Summary was devel-
oped by EPA's Hazardous Waste Engi-
neering Research Laboratory, Cincin-
nati, OH, to announce key findings of
the research project that is fully docu-
mented in a separate report of the same
title (see Project Report ordering infor-
mation at back).
Introduction
The 35 papers and 20 poster presenta-
tions presented in Sessions A and C of
EPA's Eleventh Annual Research Sym-
posium - Land Disposal, Remedial Ac-
tion, Incineration, and Treatment of
Hazardous Waste are abstracted here.
The symposium provided an effective
means for presenting the latest signifi-
cant research results of the LPCD's re-
search program to industry, state and
federal agencies, universities, environ-
mental groups, and consultants. The
symposium provided an effective
means for presenting the latest signifi-
cant research results of the LPCD's re-
search program.
The symposium was conducted with
simultaneous sessions - one for Haz-
ardous Waste Land Disposal (Session
A), one for Hazardous Waste Incinera-
tion and Treatment (Session B), and one
for poster presentations (Session C).
Presented in the proceedings are
twelve papers and four posters on un-
controlled sites and remedial actions.
The topics include assessment of cur-
rent technologies, verification of tech-
niques for remedial action, in-situ treat-
ment, site design and analysis, and site
reuse.
Thirteen papers and ten posters ad-
dress the pollutant assessment area.
Topics discussed include soil perme-
ability, column and batch leachate
methods, air emissions, and surface im-
poundment technology.
Pollutant control research is dis-
cussed in nine papers and six posters.
Subjects covered are containment and
fixation, landfill and cover design, un-
derground mine disposal, construction
quality assurance and permeability of
membrane liners.
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Land Disposal Research
Overview
Technical Resource Documents
for Hazardous Wastes
Norbert B. Schomaker
U.S. Environmental Protection
Agency
The EPA is preparing documents to
assist permit applicants and permit
writers responsible for hazardous waste
landfills, surface impoundments, land
treatment facilities and waste piles.
These Technical Resource Documents
(TRDs) describe current technologies
and methods for evaluating the perfor-
mance of the applicant's design in the
area of liners, leachate management
systems, covers, and other aspects of
the containment facilities. These docu-
ments are basically compilations of re-
search efforts of the Land Pollution Con-
trol Division (LPCD) to date in these
areas and are developed and published
to assist in the implementation of the
RCRA regulations concerning haz-
ardous waste disposal facilities. The
TRDs support RCRA Technical Guid-
ance Documents prepared by EPA's Of-
fice of Solid Waste (OSW). The Guid-
ance Documents provide details of
design and operating procedures that
contribute to the satisfactory perfor-
mance of a facility.
Sessions A-1 through A-3
Remedial Action
Evaluation of Chemical Grout
Injection Techniques for Haz-
ardous Waste Containment
Philip G. Malone
USAE Waterways Experiment
Station
Field tests were conducted to deter-
mine if a continuous impermeable seal
could be developed by injecting two
chemical grouts into coarse-grained
soils. Acrylate and sodium silicate
grouts were injected into separate 2x4
meter test beds of coarse sand at a
30-50-cm depth using a maximum hole
spacing of 40 cm (center-to-center) to
produce a pan-like layer of grout. While
some silicate grout bulbs coalesced,
there were significant gaps in the grout
layer and grout shrinkage produced
non-uniform cementing. The acrylate
grout flowed to the bottom of the sand
bed and did not produce grout bulbs.
In a large field test, 30% sodium sili-
cate was injected at 2.44 meters depth
in fine sand using injection holes on
1.52 meter centers. Significant prob-
lems were noted when the pods were
excavated. The pods were asymmetri-
cal and ungrouted areas were present.
Pockets of coarse sand in the finer sand
were not cemented although they had
been filled with grout. Root and rootlet
holes in the cemented sand were not
sealed.
Conventional injection of chemical
grouts did not produce an impervious
seal. More unusual techniques, such as
jet grouting, may be needed to obtain a
useful seal.
Permeable Materials for the
Removal of Pollutants from
Hazardous Waste Leachates
James Park
University of Cincinnati
Four readily available, low-cost per-
meable materials—limestone, coal, fly
ash, and a soil containing clay—were
tested to determine their ability to re-
move organic pollutants from two sim-
ulated hazardous waste leachates. Vari-
ous sequentially ordered layers of these
materials were evaluated for their abil-
ity to retain total organic carbon (TOC)
and 12 selected priority pollutants. The
most effective ordering of materials
was found to be a layer of fly ash, fol-
lowed by a layer of coal, followed by a
layer of limestone.
Mechanisms of Contaminant
Migration Through a Clay Bar-
rier - Case Study, Wilsonville,
Illinois
Robert Griffin
Illinois State Geological Survey
Routine monitoring of a hazardous
waste disposal facility at Wilsonville, Il-
linois revealed that organic contami-
nants were migrating 100-1000 times
faster than predicted based on labora-
tory measured hydraulic conductivity
values. A detailed hydrogeologic inves-
tigation of the site revealed that the
local ground-water flow and gradient
were dominated by a 45-ft high coal
mine refuse pile which caused radial
flow from the pile through the trenches.
Measurements of hydraulic head indi-
cated that the vertical gradient was
much less significant than the lateral
component of ground-water flow. The
distribution of contamination in the
ground water was clearly related to the
flow patterns. Time series sampling o
monitoring wells in slowly recharginc
formations showed that concentration;
of volatile organics varied wideh
through the recovery period.
Laboratory methods for measuring
hydraulic conductivity included recom
pacted and undisturbed samples. Fiek
methods included both vertical and 45
angle open hole slug tests and recover
tests on monitoring wells in each of thi
major geologic units. Angle hole
yielded higher hydraulic conductivitie
by as much as one order-of-magnitudi
compared to corresponding vertica
holes. Angle holes were interpreted a
intersecting more of the predominant!
vertical fractures present in the till tha
the vertical holes.
The hydraulic conductivity tests and
geologic investigation revealed the
some of the till units beneath th
trenches were highly fractured an
jointed and lead to the conclusion th<
the higher than predicted migratio
rates could be accounted for by the di
ferences between laboratory and fiel
measured hydraulic conductivities
These differences appear to be largel
due to the inability of small laboratoi
specimens, whether undisturbed or r<
compacted, to simulate the flo1
through cracks, joints, and fracture
present in the natural materials.
Reclamation and Redevelop-
ment of Uncontrolled Haz-
ardous Waste Sites
Garrie Kingsbury
Research Triangle Institute
Uncontrolled dumping and industri
spills have contaminated propertii
with hazardous materials (now mo
than 18,000 sites inventoried' by U.
EPA). Since many of these propertii
are in prime urban locations, issues si
rounding the reclamation and redevt
opment of contaminated propertii
have assumed national importance. Tl
principal objective of this study h
been to document with case studies r
lationships between site remediatii
methods, cleanness criteria, and rec
velopment land uses.
After extensive interviews with fe
eral and state officials, 12 uncontroll
hazardous waste sites were selected I
detailed study. For each of these siti
remedial actions have been undertak
with some upgraded redevelopment
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the property in mind. Redevelopment
includes single- and multi-family resi-
dential, recreational, commercial, insti-
tutional, and light industrial land uses.
Two distinct types of redevelopment
efforts were encountered—public-
initiated projects and developer-
initiated projects. In the case of public-
initiated projects (for example, most
Superfund sites), immediate concerns
for community health are paramount,
and site reuse, if any, tends to be inci-
dental to site cleanup.
Remedial Action Modeling of
the Western Processing and
Occidental-Lathrop Sites
Stuart Brown
CH2M Hill
Data from the Western Processing
and Occidental-Lathrop hazardous
waste sites, were used to demonstrate
and, to the extent possible, confirm the
utilization of numerical computer mod-
els for the evaluation of remedial ac-
tions at hazardous waste sites. Ground-
water flow and contaminant transport
models of the sites were developed and
calibrated against existing data.
The Western Processing model was
used to assess and rank possible reme-
dial actions for the site. Of six potential
actions, pump and treat produced the
most favorable results. Of the passive
actions, the highest degree of cleanup
was achieved by the source removal ac-
tion.
The Occidental model was used to
evaluate the effectiveness of an in-
stalled ground-water extraction, treat-
ment, reinjection system. The model
under-predicted plume reduction and
the concentration of contaminant at the
extraction wells during a one-year pe-
riod after startup. This under-prediction
was attributed to a conceptual model
that could not represent transport of
contaminant through sand and gravel
preferred pathways. Long-term model
predictions show a stagnation of the
plume that may require relocation of ex-
traction wells for complete plume
cleanup.
Model results helped to confirm the
use of numerical models for the evalua-
tion of hazardous waste sites. More
specifically, simulation of the sites
helped to: 1) identify data deficiencies
and help improve the understanding of
contaminant transport at the site;
2) rank remedial action alternatives at
the Western Processing Site; and
3) show the importance of recalibration
and reevaluation of the conceptual
model as more data become available.
Demonstration of a Geographic
information System for Haz-
ardous Waste Site Analyses
Margrit von Braun
University of Idaho
This paper investigates the applicabil-
ity of a Geographic Information System
(GIS) to the study of a hazardous waste
site. Existing data including aerial pho-
tographs, maps, and site study reports
were digitized to create a spatial data
base for an active Superfund site. These
computer maps were then analyzed by
cartographic modeling techniques to
assess current site conditions and
prospective remedial actions. Existing
site drainage basins were identified and
characterized in terms of stormwaters
ran off-site or infiltrated on-site. Wastes
were inventoried within each basin, and
stormwater/waste-contact budgets
were developed for each drainage
stream. Additional computer maps
were then constructed to represent vari-
ous remedial action scenarios. Storm-
water/waste-contact budgets were de-
veloped for various combinations of
berms, dikes, and asphalt covers. These
alternatives were evaluated according
to the estimated reductions in waste
contacted runoff and infiltration. Exca-
vation volume estimates were devel-
oped for the several above-grade waste
types and successive estimates were
accomplished for removing contami-
nated soils down to the ground-water
table.
Field Determination of Hy-
draulic Conductivity and Ben-
tonite Content During Slurry
Wall Construction
Matthew J. Barvenik
Goldberg, Zoino & Associates,
Inc.
Soil/bentonite backfilled cutoff walls
(slurry walls) have been used over the
past several years to contain and isolate
hazardous wastes. Although many
slurry walls have been installed, their
effectiveness and construction quality
have not been studied or documented
to any extent. This paper reports on the
first phase of testing at the Gibson Road
Site at Nashua, New Hampshire. The
objective of this phase is to evaluate
quality control measures for bentonite
content and hydraulic conductivity de-
terminations. This paper specifically ad-
dresses the methylene blue titration for
bentonite content determination and
the API fixed ring permeameter for hy-
draulic conductivity determination. This
paper discusses the applicability and
practicability of these tests for field and
quality control.
Control of Fugitive Dust Emis-
sions at Hazardous Waste
Cleanup Sites
Keith D. Rosbury
PEI Associates, Inc.
Three field studies were performed to
determine the effectiveness of dust con-
trol strategies at hazardous waste sites.
Twelve dust suppressants were tested
to determine the effectiveness of fugi-
tive dust control against wind erosion
from exposed areas. Based on a tracer
sampling protocol, the suppressants
were totally effective for 1 to 4 weeks
after application, with declining control
efficiencies thereafter. The second wind
erosion field study was an evaluation of
the effectiveness of windscreens and
windscreen/dust suppressant combina-
tions in controlling fugitive dust from
storage piles. Based on 82 tests, the
windscreen showed no consistent sig-
nificant level of control of particles s10
micrometers. The wind erosion emis-
sion rate of particles ^s10 micrometers
is fairly constant at windspeeds above a
threshold of about a 7 mph average.
The windscreen may control larger par-
ticles more effectively, but these parti-
cles are less of a threat because they
exceed the inhalable size and are not
carried long distances in the wind.
Chemical stabilizers were superior in
performance to the windscreen. The
third field study, investigating active
cleanup emissions, consisted of testing
fugitive dust control measures applica-
ble to the use of a front-end loader to
load dirt into a truck. Control efficiencies
of 41 to 77 percent were measured for
area spraying and spray curtains. In
general, chemical dust suppressants
are often wastes or by-products them-
selves. Before applying a dust suppres-
sant, the user should analyze the dust
suppressant for toxic substances and
test for reactivity between the dust sup-
pressant and the contaminated soil.
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Practical Methods for Decon-
taminating Buildings, Struc-
tures and Equipment at Super-
fund Sites
M. P. Esposito
PEI Associates, Inc.
Practical methods for decontaminat-
ing buildings, structures, and equip-
ment at Superfund sites are described
in a new EPA handbook. Techniques
presented include: asbestos abatement,
absorption, demolition, dismantling,
dusting/vacuuming/wiping, encapsula-
tion/enclosure, gritblasting, hydroblast-
ing/waterwashing, painting/coating,
K-20, scarification, RadKleen, solvent
washing, steam cleaning, vapor-phase
solvent extraction, acid etching, bleach-
ing, flaming, drilling and spading, mi-
crobial degradation, and photochemical
degradation. Method descriptions in-
clude a general discussion of the proce-
dure, advantages, disadvantages, appli-
cability, effectiveness, engineering
considerations (including building prep-
aration, process description, and equip-
ment needs), safety requirements,
waste disposal, and costs. Potential de-
contamination techniques for a given
contaminant/structural material combi-
nation are identified in a matrix. Other
information presented in the manual in-
cludes stepwise guidance for develop-
ing a cost-effective decontamination
strategy, case studies illustrating the ac-
tual application of many decontamina-
tion methods, cost analyses for the ap-
plication of each method of a model
building, a discussion of worker health
and safety precautions, and a summary
of available sampling techniques.
In-Situ Treatment of Contami-
nated Groundwater and Soils
Roger Wetzel
JRB Associates
In-situ biological degradation has
been selected for field demonstration at
a waste disposal site at Kelly Air Force
Base, Texas. The in-situ biodegradation
treatment of this site will involve the in-
troduction of oxygen to the subsurface
and the circulation of water by an ex-
traction/infiltration system. Extensive
investigation has been necessary to
characterize the site, demonstrate the
effectiveness of the biological treatment
in the laboratory, and determine the
modifications of site conditions re-
quired to approach the optimum for
treatment. The four elements of the pro-
ject necessary to provide the informa-
tion required for the design and imple-
mentation of the field demonstration
are 1) geological investigation and site
characterization, 2) determination of the
contaminant profile, 3) microbiological
investigation, and 4) laboratory biodeg-
radation investigation. The results of
each element of the project are summa-
rized, and recommendations for design
and implementation of the field demon-
stration are made based on these re-
sults.
Case Study Investigations of
Remedial Response Programs
at Uncontrolled Hazardous
Waste Sites
Claudia Furman
JRB Associates
Section 105(7) of the Comprehensive
Environmental Response, Compensa-
tion and Liability Act of 1980 (CERCLA)
requires that USEPA establish means of
ensuring that remedial actions are cost-
effective over the period of potential ex-
posure to hazardous substances or con-
taminated materials. In partial support
of this objective, USEPA has been di-
recting the preparation of detailed case
studies on remedial responses at un-
controlled hazardous waste sites. De-
tailed information has been collected on
cost, institutional, and technical issues
related to the implementation and effec-
tiveness of remedial actions at these
sites. Compiled into a succinct case
study, this historical information can
then be used in planning, selecting, de-
signing, and cost analyzing future reme-
dial actions.
The project discussed here is a contin-
uation of earlier case study activities
where 23 case studies were published
(USEPAIa], 1984). The focus of this
more recent series of eight case studies
(USEPA[c]), however, was on fund-
financed or enforcement actions, as
opposed to the earlier studies which fo-
cused on private- and State-lead ac-
tions. Within this report, the eight case
studies are briefly described in table for-
mat, followed by a more comprehen-
sive discussion of four of the eight re-
medial case studies.
Effect of Freezing on the Level
of Contaminants in Uncon-
trolled Hazardous Waste Sites
Part 1: Concepts and Litera-
ture Review
Iskandar K. Iskandar
U.S. Army Corps of Engineers
A literature search indicated that na
ural freezing may have detrimental e
fects at uncontrolled hazardous wasi
sites in the cold dominated areas bi
cause of frost action on buried materia
and ion movement in soils. Natural ar
artificial freezing, however, can be use
beneficially to concentrate effluents ar
to dewater sludges, contaminated sec
ment and soils. The process of artifici
ground freezing can also be used as i
alternative to temporarily immobili;
contaminant transport and, potentiall
for decontaminating soils, sedimen
and sludges. A cost and economic an.
ysis procedure was developed and us<
to evaluate ground freezing.
Sessions A-4 through A-6-
Pollutant Assessment
VOC Emission Reductions froi
Surface Impoundments by ust
of Wind Fences and Wind Bar
riers
Louis Thibodeaux
Louisiana State University
Quantities of hazardous waste mate
als in liquid, sludge or solid form can
disposed on or near the soil surface.
common disposal operations uses si
face impoundments for aqueous was
Proper design and operation pro(
dures can result in significantly reduc
emissions of hazardous volatile speci
to the surrounding air.
Surface impoundments usually cc
sist of shallow earthen basins. Aquec
and non-aqueous wastes are placed
these open-top basins for treatment
selected waste or for storage. Volati
may escape to the air boundary lay
but significant reduction in emission;
possible by using perimeter and n
work fences. Desorption data were <
tained on a pilot scale apparatus usi
ethyl ether as the model chemical. Fo
percent reduction in emission of et
ether was achieved with this liqu
phase controlled volatile chemi
using solid perimeter fences. Sever
eight percent reduction was achie\
with solid fence networks.
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Investigation of Floating Im-
miscible Liquids to Control
Volatile Organic Chemical
Emissions from Surface Im-
poundments
Charles Springer
University of Arkansas
Floating immiscible liquids were in-
vestigated as a control option for
volatile organic chemical emissions
from a laboratory scale waste water im-
poundment. Three different immiscible
organic liquids were used—mineral oil,
octanol and lauryl alcohol. A three
phase resistance-in-series model was
proposed. Experiments with complete
surface coverage and thick mineral oil
layer showed a considerable decrease
in the emission rates only for those
compounds with low oil solubility. On
the other hand, the emission rate was
less significantly reduced for chemicals
with high oil solubility.
Leaching Potential of 2,3,7,8-
Tetrachlorodibenzo-p-Dioxin in
Contaminated Soils
Danny Jackson
Battelle Columbus Laboratory
Ten soils contaminated with 2,3,7,8-
tetrachlorodibenzo-p-dioxin (2,3,7,8-
TCDD) between 1968 and 1971 were col-
lected from locations in Missouri and
New Jersey. Partition coefficients (Kp
and Koc) for 2,3,7,8-TCDD were deter-
mined for the group of soils based on
2,3,7,8-TCDD concentrations in soil and
soil leachate. Mean log Koc values ob-
tained from three different leaching
methods (7.15, 7.34, and 7.35) were
within one standard deviation of a pre-
dicted value of 6.95. Soil physical and
chemical properties were determined
as explanatory variables to account for
observed variability in Kp values and
2,3,7,8-TCDD concentrations in soil
leachate. Solvent extractable chlori-
nated organic carbon content of soils
was found to greatly influence the parti-
tioning of 2,3,7,8-TCDD between the soil
solid-phase and soil leachate. An ana-
lytical solution of a solute transport
equation and a retardation equation
were used to predict mobility of 2,3,7,8-
TCDD in soils. Predicted 2,3,7,8-TCDD
movement rates for convection and dis-
persion in soil pore fluids were ex-
tremely slow. A number of other pro-
cesses may cause actual movement
rates to be greater or smaller than pre-
dicted.
Development of Standardized
Batch Adsorption Procedures:
Experimental Considerations
William R. Roy
Illinois State Geological Survey
A Technical Resource Document
(TRD) is being developed to provide in-
formation on the use of batch proce-
dures for determining the adsorption
capacity of soils for solutes in waste
leachates. The TRD will be part of the
technical basis for guidance by the Of-
fice of Solid Waste on design and evalu-
ation of compacted soil liners for waste
storage and disposal facilities. In devel-
oping the batch procedures for the TRD
it was found that the method of mixing
the solute-soil mixtures influenced their
adsorption by soil; more vigorous shak-
ing resulted in greater adsorption. To
obtain better reproducibility, a National
Bureau of Standards rotating tumbler
was adopted as the method of choice. A
mixing interval of 24 hours appears to
be a valid operational definition of equi-
librium for these types of batch proce-
dures. Changes in solution concentra-
tion of arsenic and cadmium were
negligible after 10 hours when exposed
to different soil materials. Solution ra-
tios for inorganic solutes must be found
empirically, but suitable ratios for hy-
drophobic organic solutes can be esti-
mated from the solubility of the com-
pound in water and the organic carbon
content of the soil.
Clay Liner Systems: Current
Design and Construction Prac-
tices
Leonard J. Goldman
Research Triangle Institute
Information is presented on selected
aspects of hazardous waste facility clay
liner design and construction. The infor-
mation has been gathered as part of the
effort associated with the production of
the Technical Resource Document: De-
sign, Construction, Maintenance and
Evaluation of Clay Liners for Hazardous
Waste Facilities (EPA Contract No. 68-'
03-3149-1-2). The sources of informa-
tion were the published literature and
interviews with approximately 30 geo-
technical engineers and engineering ge-
ologists in the fields of liner design,
liner construction, waste management,
and governmental oversight of haz-
ardous waste disposal activities. Collec-
tively, these professionals had experi-
ence with clay lined facilities located in
nearly all parts of North America.
Effects of Inorganic Leachates
on Clay Soil Permeability
J. Jeffrey Pierce
Duke University
Hydraulic conductivity laboratory test
results for three clay soils exposed to
two inorganic chemicals are docu-
mented, the potential usefulness of five
additional laboratory tests for predict-
ing clay/chemical compatability is dis-
cussed, and an extensive literature re-
view is summarized. Researchers have
studied the effects of organic solvents
on the hydraulic conductivity of com-
pacted clays, and results indicate many
of these solvents cause increases in hy-
draulic conductivities. Limited informa-
tion, however, is available in the litera-
ture concerning the effects of inorganic
chemicals on the hydraulic conductivi-
ties of clays.
In this research project, the hydraulic
conductivities of three field clays—
White Store, Hoytville, and Faceville—
permeated with ferric chloride (500
mg/l) and nickel nitrate (50 mg/l and
300,000 mg/l) were determined using
both fixed and flexible-wall permeam-
eters. Results indicate that at the con-
centrations tested, neither chemical
significantly altered the hydraulic con-
ductivities of the three clay soils. The
predictive test results are seen to be in-
conclusive because, as indicated, no
changes in hydraulic conductivities
were observed.
Effective Porosity of Geologic
Materials
James P. Gibb
Illinois State Water Survey
The understanding of effective poros-
ity and the development of a method for
measuring the effective porosity of geo-
logical materials is essential to predict
the rates of ground-water solute move-
ment through those materials. This
project is designed to explore the phe-
nomenon of effective porosity as a dy-
namic soil/solute parameter. Modern
chromatographic techniques are being
adapted for measuring the effective or
dynamic porosity of unweathered, un-
oxidized clay soils at three sites. Prelim-
inary work has isolated some problems
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associated with collecting undisturbed
soil samples and conducting tracer ex-
periments on low hydraulic conductiv-
ity soils in laboratory columns.
Solubility Parameters for Pre-
dicting Membrane-Waste Liq-
uid Compatibility
Henry Haxo
Matrecon, Inc.
Swelling of a polymeric membrane
liner by adsorption of waste liquids can
result in softening. Toss of mechanical
strength and elongation, an increase in
permeability, an increased tendency to
creep under load, and greater suscepti-
bility to polymer degradation. The sig-
nificant factors involved in the swelling
of a polymeric composition in a liquid
are:
- Solubility parameter or cohesive
energy density of the polymer rela-
tive to that of the liquid.
- Crosslinking of the polymer.
- Crystallinity of the polymer.
- Filler, plasticizer, and soluble con-
stituents in the total compound.
Of these, solubility is probably the most
significant factor and the subject of this
new research project.
Most organic waste constituents have
solubility parameters in the range of
9-10, which is in the same range as poly-
mers used in the manufacture of the
membranes. This indicates the need for
selecting liner materials that have solu-
bility parameters differing from the or-
ganic components of the wastes to be
impounded.
This paper presents an analysis of
data from the literature with respect to
the solubility parameters of waste liq-
uids and of polymeric materials; it also
presents the results of laboratory test-
ing of selected commercial lining mate-
rials in various organic solvents having
different solubility parameters.
Analysis of Leachate Produc-
tion in Closed Hazardous
Waste Landfills
Randy R. Kirkham
Battelle Northwest Laboratories
Hazardous wastes disposed of in
landfill sites may continue to drain for
several years after site closure.
Leachate sources include waste fluids
as well as meteoric water trapped in the
landfill during construction and opera-
tion. Waste fluid may be released
through barrel degradation, and inter-
stitial fluid may be released during sub-
sidence or compression of waste mate-
rials. Water may also continue to enter
the landfill through structural faults.
Predictions of rates and amounts of
leachate production can be developed if
the hydraulic parameters or specific-
yield values for the hazardous waste
and backfill materials are known. A liter-
ature search showed that limited hy-
draulic parameters and specific-yield in-
formation is available. Unit-gradient
and specific-yield modeling approaches
were evaluated for use at hazardous
waste landfills. Specific yield was deter-
mined for two data sets: one collected
by a commercial hazardous waste site
operator and provided to us by the state
regulatory agency >and the other col-
lected by the authors at a hazardous
waste site located in New York State.
Specific-yield values of approximately
10 to 16% were calculated for the first
data set. These values are within the
range of reported values for similarly
designed municipal waste landfills. A
specific yield of 25% was calculated for
recent hourly leachate level data col-
lected by the authors at the New York
State site.
Precision and Reliability of Lab-
oratory Permeability Measure-
ments
John L Bryant
University of Cincinnati
Preliminary laboratory permeability
test data were gathered from nine
sources to create a data bank suitable
for statistical analysis. The collected
data also yielded a survey of the most
commonly used permeameters and
testing methods for clay liner perme-
abilities.
This paper describes the methods
used to collect and organize the data.
Tentative findings are discussed. Con-
sideration is given to the degree of vari-
ability found in replicated permeability
tests, the question of sample equilibra-
tion, parameters of sample preparation
which may lead to sizable errors in per-
meability determinations, and the
amount of variability of permeabilities
that may be found in location-to-
location sampling from within a source
of liner material.
Simulating Landfill Cover Sub-
sidence
Harry Sterling
Daniel Engineering
The subsidence response of the clay
layer of a landfill was modeled using a
geotechnical centrifuge. Data were col-
lected to determine the effects of cavity
width, clay moisture content, time to
failure (cracking or collapse) when the
critical cavity diameter was reached,
and qualitative descriptions of the fail-
ure mechanisms. The prototype struc-
tures for the clay model layers were the
multi-layered covers being tested as
part of an EPA-sponsored investigation
of hydrologic isolation. These struc-
tures consisted of three 2 ft. (0.61 m)
layers, with a compacted clay layer at
the bottom, covered by sand, and finally
top soil. The clay layer was modeled in
the laboratory at 1/48, 1/32, 1/24, and
1/16 scales, and was surcharged with
lead shot to simulate the overburden
due to the other two layers. The scope
of the work was limited to clay layers
subjected to slump, a type of subsi-
dence characterized by localized void
spaces beneath the covers.
Clay layer behavior was dependent
upon both the moisture content and
cavity width. Field cavity widths of 4 ft.
(1.2 m) were successfully bridged by all
models tested at that width, but failures
and extensive cracking occurred for
many models simulating both 8 ft. (2.4
m) and 12 ft. (3.7 m) field cavities. Col-
lapse of the samples at the 8 ft. width
occurred at optimum moisture content
(which also was the plastic limit of the
clay soil), while sample collapse at the
12 ft. width occurred at moisture con-
tents 3 percent below optimum. Quali-
tatively, soil cracking features were sim-
ilar to those reported at field sites
investigated by other workers.
The centrifuge modeling procedure
has promise as an investigative tool to
determine the physical mechanisms of
subsidence and may be used to test a
variety of different configurations for
subsidence response in order to deter-
mine optimum landfill cover designs.
Leachate Collection Systems—
Summarizing The State-of-the-
Art
Jeffrey M. Bass
A.D. Little, Inc.
A manual has been prepared to sum-
marize the state-of-the-art in leachate
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collection system design, construction,
inspection, maintenance and repair as it
pertains to system failure. Leachate col-
lection system failure mechanisms, as
well as design, construction, inspection,
maintenance and repair practices which
may reduce the likelihood of failure are
reviewed.
Verification of Leachate Collec-
tion Efficiency with Physical
Models
Paul Schroeder
USAE Waterways Experiment
Station
Two large-scale physical models of
landfill/liner/drain systems were con-
structed to examine the effects of
length, slope and hydraulic conductivity
of the drain layer and the depth of satu-
ration above the liner on the subsurface
lateral drainage rate. The models have
two different lengths and adjustable
slopes. They were filled with a 3-foot
sand drain layer overlying a 1-foot clay
liner. A 2-inch layer of gravel was placed
under the liner to collect seepage from
the clay liner. The design, construction,
instrumentation and preparation are de-
scribed in detail.
Several drainage tests were run on
each configuration of the models by ap-
plying water as rainfall to the surface of
the sand layer and then measuring the
water table along the length of the mod-
els and the drainage rate as a function
of time. The experimental design and
test procedures are presented along
with some descriptive results.
Sessions A-8 through A-9
Pollutant Control
Waste-Liner Compatibility
Studies
Warren B. Lyman
A.D. Little, Inc.
Three different programs of study
were undertaken focusing on the com-
patibility of synthetic liners (principally
flexible membrane liners (FML) with
hazardous wastes. In Study I, qualitative
and quantitative information on the
chemical resistance of FML materials
was collected from vendor and techni-
cal publications. This information was
compiled into a computer data base
comprising about 3,000 data fields on
23 liner materials and over 500 chem-
icals. Criteria for assessing this infor-
mation on a common basis were de-
veloped, with separate guidelines
established for olefinic and non-olefinic
liner materials. On the basis of these cri-
teria, normalized ratings of chemical re-
sistance were developed for each chem-
ical/material pair for which there were
data. The Study report contains these
ratings (over 1,300) as well as a listing of
the raw data from which they were de-
rived.
In Study II, a search was made for lab-
oratory test methods that were or could
be used to ascertain the compatibility of
flexible membrane liners with haz-
ardous wastes. Twenty-seven identified
methods, from the United States and
foreign countries were examined and
compared. Each pertinent test is de-
scribed in the Study report. The report
also discusses the basis for these tests
and the extent to which they can realisti-
cally be expected to reflect short- and
long-term liner performance.
In Study III, research was undertaken
to evaluate routes to estimating chemi-
cal/liner compatibility. Proven estima-
tion techniques might be used, for ex-
ample, in prescreening FML materials
to be tested for compatibility with a
waste, or estimating the resistance of an
existing FML liner to a new chemical in
the waste. This study showed that one
approach using solubility parameters
can provide useful information in many
situations. Solubility parameters were
shown to be useful in three different
ways, in solubility parameter maps, sta-
tistical correlations, and with the use of
the exchange energy density parame-
ter.
Recovery and Testing of a Syn-
thetic Liner from a Waste La-
goon after Long-Term Expo-
sure
Henry Haxo
Matrecon, Inc.
Samples of a 100-mil high-density
polyethylene (HOPE) liner were recov-
ered from a waste lagoon in the north-
eastern United States after 4.75 years of
exposure at different depths and tested
to determine the effects of the exposure
on physical properties. The recovery
was performed during removal of the
lagoon in a Superfund Remedial Action.
The impounded waste liquid was pre-
dominantly aqueous and contained sig-
nificant amounts of organics, particu-
larly chlorinated hydrocarbons, the
concentration of which increased with
depth.
Overall, the liner appeared to be in
satisfactory condition. There was no ev-
idence to indicate that it had cracked or
failed, but it did show considerable
waviness and distortion on the berm
and slopes.
Liner samples were analyzed and
tested. Samples of the HOPE liner from
the bottom of the lagoon had absorbed
about 2% waste and showed a 10% loss
in tensile at yield and similar losses in
modulus. The samples taken from the
slopes of the lagoon showed essentially
no change in properties. The use of con-
struction equipment in attempting to re-
move the waste without damaging the
liner was unsuccessful, and the liner on
the bottom of the lagoon was destroyed
during the cleanup operations.
Strength and Durability of Flex-
ible Membrane Liner Seams
After Short-Term Exposure to
Selected Chemical Solutions
Ronald Frobel
U.S. Bureau of Reclamation
In March 1983, the United States Envi-
ronmental Protection Agency (USEPA)
began research with the United States
Bureau of Reclamation (USBR) to evalu-
ate flexible membrane liner (FML)
seams exposed to selected environ-
mental conditions over short periods. A
total of 37 combinations of reinforced
and nonreinforced FML materials joined
by various seaming methods have been
subjected to six chemical solutions,
brine, tap water, and accelerated out-
door aging by ultraviolet light. Eval-
uation of the effects of these types of
environmental conditions included de-
structive and nondestructive testing.
The destructive tests performed before
and after exposure were dynamic load,
shear and peel at room temperature,
and static dead load at 50°C. The nonde-
structive tests performed on unexposed
samples only were acoustic methods,
air lance, vacuum chamber, double
seam pressurization, and mechanical
point stress.
To date, tests have been completed
on unexposed seams and seams that
have been exposed for 3 months. Expo-
sures for six and 12 months are cur-
rently underway. The results and evalu-
ation of the nondestructive tests and the
-------
3-month chemical exposures are pre-
sented in this paper.
Chemical Mass Transport Mea-
surements to Determine Flexi-
ble Membrane Liner (FML) Life-
time
Arthur Lord
Drexel University
The prediction of the service life of
flexible membrane liners (FMLs) when
exposed to chemicals has usually the
result of testing for physical or mechan-
ical property changes after periodic in-
cubations. This paper presents an alter-
native that makes use of four different
diffusion-related measurements of the
incubated FML. These tests are water
vapor transmission (WVT) radioactive
tracer transmission (RT), water absorp-
tion (WA) and water vapor absorption
(WVA).
This approach was tested for up to
6-month exposure times. The FMLs
used were PVC, EPDM and CPE. The
chemicals used were 10% NaOH (in
water), 10% H2SO4 (in water), 10% phe-
nol (in water) and 100% xylene. The
WVT and RT were found to be quite reli-
able test methods, whereas significant
problems occurred with the WA and
WVA. Various transport coefficients
showed all the expected behaviors with
chemical exposure:
• constancy (acids and bases on all
FMLs)
• decrease (plasticizers leaching from
FMLs)
• increase (Phenol-treated CPE and
EPDM in H2SO4)
The WVT and RT results were gener-
ally comparable in all but one situation,
that of CPE-phenol. Here WVT showed
about a fourfold increase in permeabil-
ity, whereas RT showed essentially no
change in diffusivity.
Although it is preliminary, the work
reported here lends credence to the use
of mass transport measurements to de-
termine structural change in FMLs and
hence a prediction of their lifetime.
A Technique for Retrofitting
Impoundments with Geomem-
branes
David Shultz
Southwest Research Institute
This paper presents the results of a
project to investigate techniques for
retrofitting existing surface fluid im-
poundments with a flexible membrane
liner or geomembrane. The project was
performed as three separate studies.
The first was conducted to examine var-
ious retrofit concepts. The most promis-
ing concepts were then tested using a
small physical scale model.
The most practical and successful
concept was the pull-through tech-
nique, in which the geomembrane is
pulled along the sides and bottom of an
impoundment. Large-scale demonstra-
tion of this technique was carried out at
a one-acre fluid impoundment con-
structed at Southwest Research Insti-
tute.
The Role of Impoundment Size
in Controlling Environmental
Risk at Hazardous Waste Sur-
face Impoundments
Gordon B. Evans, Jr.
K.W. Brown & Associates
The environmental damage due to a
hazardous waste surface impoundment
failure is greatly affected by the im-
poundment size (volume). This research
determined if multiple-small impound-
ments, designed to contain the same
waste volume as one large impound-
ment, would present less environmen-
tal risk than the large impoundment.
Three surface impoundment design
scenarios (large, small-attached, small-
unattached) were compared based on
the environmental damage that would
result from two failure situations: sur-
face (catastrophic) and subsurface
(long-term). The reduced risk from
using smaller impoundments was then
compared to the increase in construc-
tion cost due to constructing more than
one impoundment. It was concluded
that there are no real advantages to lim-
iting the size of surface impoundments.
Several design features are suggested
which should greatly reduce the risks
associated with surface impoundment
failures.
Update: Storage of Hazardous
Waste in Mined Space
Ronald B. Stone
Fenix & Scisson, Inc.
This report presents the results of the
assessment of the use of mined space
for long-term retention of non-
radioactive hazardous waste. The report
updates previous studies conducted
from 1974-1977, and examines recent
literature, recent project activities, in-
volvement of government agencies,
regulatory and permitting require-
ments, selection of existing mines for a
demonstration project and presents a
new approach proposed by industry,
the use of solution-mined space for re-
tention of hazardous waste in salt.
Factors Affecting Stabilization/
Solidification of Hazardous
Waste
Jerry N. Jones
USAE Waterways Experiment
Station
The stabilization/solidification of toxic
wastes involves a series of chemical
and/or physical treatment procedures.
The waste is normally treated so as to
complex or bind the toxic elements in a
stable, insoluble form or to entrap the
waste material in a crystalline matrix. A
hazardous waste may contain many
constituents that could interfere with
the binding process. This recently initi-
ated project identifies possible interfer-
ing mechanisms between particular
compounds and waste binding sys-
tems.
A synthetic sludge was produced con-
taining parts per million concentrations
of cadmium, chromium, mercury, and
nickel. The sludge was mixed with in-
creasing concentrations of interfering
compounds and then with selected
waste binders. Various waste mixtures
are being evaluated to determine the
particular interfering effects on stabi-
lization/solidification processes. This
paper is an interim report on the
progress of the study.
Construction Quality Assurance
for Hazardous Waste Disposal
Facilities
Coleen Northeim
Research Triangle Institute
This paper describes the specific ele-
ments of a Construction Quality Assur-
ance (CQA) Plan for the structural com-
ponents of a hazardous waste land
disposal facility, e.g., clay liner, dike,
flexible membrane liner, leachate col-
lection system, and cover system. The
paper refers to EPA's draft technical
guidance entitled "Minimum Technol-
ogy Guidance on Double Liner Systems
for Landfills and Surface Impound-
ments—Design, Construction, and Op-
eration" (MTG). This paper discusses
the specific CQA components listed in
the MTG which are: (1) responsibility
8
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and authority, (2) personnel qualifica-
tions, (3) observation and tests, (4) de-
sign of a samplng program, and (5) doc-
umentation. A table identifying the
facility structural components and the
important factors to be controlled dur-
ing their installation is also presented.
Session C
Land Pollution Control Division
Posters
Poster Presentations
The posters presented at the Eleventh
Annual Research Symposium are listed
with their authors, as follows:
1. Computer Analysis of Hazardous
Waste Dikes
Andrew Bodosci
University of Cincinnati
Cincinnati, OH
2. Two Automated Systems for On-
Scene Coordinators
Richard Hildreth
JRB Associates
McLean, VA
3. Field Verification of Landfill Cover
System Construction to Provide
Hydrologic Isolation
Richard Warner
University of Kentucky
Lexington, KY
4. Operation of the Center Hill Pilot
Plant and Soils Laboratory for Su-
perfund and RCRA Research Proj-
ects
Gerard Roberto
University of Cincinnati
Cincinnati, OH
5. Evaluation of Stabilized Oioxin
Contaminated Soils
William Vick
JRB Associates
McLean, VA
6. Reclamation and Reuse of Con-
taminated Land in the United
States, England and Wales
Tayler Bingham
Research Triangle Institute
Research Triangle Park, NC
7. Maintenance Free Vegetative
Systems for Landfill Covers
John C. Rodgers
Los Alamos National Laboratory
Los Alamos, NM
8. Chemical Resistance of Flexible
Membrane Liners Immersed in
Selected Aqueous Solutions
Gordon Bellen
National Sanitation Foundation
Ann Arbor, Ml
9. Relationship of Laboratory and
Field Determined Hydraulic Con-
ductivity in Compacted Clay Soils
Andrew S. Rogowski
USDA-ARS
University Park, PA
10. Critical Review and Summary of
Gas and Leachate Production
from Landfills
Fred Pohland
Georgia Tech
Atlanta, GA
11. Hydraulic Conductivity of Two
Prototype Clay Liners
David E. Daniel
University of Texas
Austin, TX
12. Clay Chemical Compatibility and
Permeability Testing: A Review
R.S. Truesdale
Research Triangle Institute
Research Triangle Park, NC
13. Clay Liner Transit Time Prediction
Methods and Effects of Leachate
Composition on Liner Infiltration
Ashok S. Damle
Research Triangle Institute
Research Triangle Park, NC
14. Effective Porosity of Compacted
Clay Soils Permeated with Or-
ganic Chemicals
Janice W. Green
Arthur D. Little, Inc.
Cambridge, MA
15. Influence of Concentrations of Or-
ganic Chemicals on the Colloidal
Structure and Hydraulic Conduc-
tivity of Clay Soils
K.W. Brown
Texas A&M University
College Station, TX
16. Assessment of Synthetic Mem-
brane Successes and Failures at
Waste Storage and Disposal Sites
Jeffrey M. Bass
A.D. Little, Inc.
Cambridge, MA
17. An Electrical Technique for De-
tecting Leaks in Membrane Liners
David W. Shultz
Southwest Research Institute
San Antonio, TX
18. Laboratory Determination of Di-
electric Constant and Surface
Tension as Measures of Liner/
Leachate Compatibility
Charles Mashni
LPCD/CB, U.S. Environmntal Pro-
tection Agency
Cincinnati, OH
19. Quick Indicator Tests to Charac-
terize Bentonite Types
Richard M. McCandless
University of Cincinnati
Cincinnati, OH
20. Estimating Transit Times of Non-
interacting Pollutants Through
Compacted Soil Materials
Robert Horton
Iowa State University
Ames, IO
The full report was submitted in fulfill-
ment of Contract No. 68-03-3131 by the
JACA Corporation under the sponsor-
ship of the U.S. Environmental Protec-
tion Agency.
-------
The EPA authors. Donna A. Zunt and Naomi P. Barkley (also the EPA Project
Officer, see below), are with Hazardous Waste Engineering Research Labora-
tory, Cincinnati, OH 45268.
The complete report, entitled"Land Disposal of Hazardous Waste: Proceedings of
the Eleventh Annual Research Symposium at Cincinnati, Ohio, April29-May 1,
1985." (Order No. PB85-196376/AS; Cost: $29.50, subject to change) will be
available only from:
National Technical Information Service
5285 Port Royal Road
Springfield. VA 22161
Telephone: 703-487-4650
The EPA Project Officer can be contacted at:
Hazardous Waste Engineering Research Laboratory
U.S. Environmental Protection Agency
Cincinnati, OH 45268
10
•&U. S. GOVERNMENT PRINTING OFFICE:1985/559-l 11/20616
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