United States
Environmental Protection
Agency '
Municipal Environmental
Research Laboratory
Cincinnati OH 45268
Research and Development
EPA-600/S9-84-007 May 1984
Project Summary
Land Disposal of Hazardous Waste
Proceedings of the Tenth Annual
Research Symposium
David M. Goertemoeller and Naomi P. Barkley
Proceedings are summarized for Ses-
sion A of the U.S. Environmental Pro-
tection Agency's (EPA's) Tenth Annual
Research Symposium — Land Disposal,
Remedial Action, Incineration, and
Treatment of Hazardous Waste. The
symposium was held In Fort Mitchell,
Kentucky, April 3-6, 1964. Session A,
Hazardous Wastes Land Disposal, in-
cluded 20 papers and 9 poster presenta-
tions concerning the status of research
projects sponsored by EPA's Solid and
Hazardous Waste Research Division
(SHWRD) of the Municipal Environ-
mental Research Laboratory (MERL) in
Cincinnati, Ohio. Land Disposal papers
are presented in the areas of remedial
action, pollutant assessment, and pollu-
tant control. They discuss landfill design
and operation, waste leaching and
analyses, pollutant migration and con-
trol, waste modification, surface im-
poundments, technology assessment.
remedial action techniques, and cost
and economics.
Session B, Hazardous Waste Incinera-
tion and Treatment, will be published as
a separate document by EPA's Industrial
Environmental Research Laboratory
(IERL) in Cincinnati, Ohio.
This Project Summary was developed
by EPA's Municipal Environmental
Research Laboratory, Cincinnati, OH, to
announce key findings of the research
project that is fully documented in a
separate report of the same title (see
Project Report ordering information at
back).
Introduction
The 20 papers and 9 poster presentations
presented in Session A of EPA's Tenth An-
nual Research Symposium — Land Disposal,
Remedial Action, Incineration, and Treat-
ment of Hazardous Waste are abstracted
here. Two EPA dhrisions sponsored the sym-
posium: the SHWRD of the MERL and the
Energy Pollution Control Division (EPCD) of
the IERL, both in Cincinnati, Ohio.
Attendees included representatives from
industry, state and federal agencies, univer-
sities, environmental groups, and con-
sultants. The symposium provided an
effective means for presenting the latest
significant research results of the SHWRD's
research program.
The symposium was conducted with
simultaneous sessions — one for Hazardous
Waste Land Disposal (Session A), and the
other for Hazardous Waste Incineration and
Treatment (Session B). This scheduling
allowed attendees to alternate sessions as
desired. The proceedings for Session B will
be published as a separate report by IERL.
Concurrent Poster sessions were held on
April 3 and 4. The presenters were available
to discuss their work and answer questions
at scheduled times and the posters were on
display throughout the symposium.
The proceedings presents nine papers and
eight posters on uncontrolled sites and
remedial actions. The topics include assess-
ment of current technologies, verification of
techniques for remedial action, in-sftu treat-
ment, site design and analysis, and costs.
Seven papers and one poster address the
pollutant assessment area. Topics discussed
include soil permeability, column and batch
teachate methods, air emissions, and surface
impoundment technology.
Pollutant control research is discussed in
four papers. Subjects covered are contain-
ment and fixation, landfill and cover design,
settlement and cover subsidence, and per-
meability of membrane liners.
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Land Disposal Research
Overview
Current Research on Land
Disposal of Hazardous Wastes
Norbert B. Schomaker and
Douglas P. Doerr,
U.S. Environmental
Protection Agency
EPA's SHWRD is responsible for research
on land disposal of solid and hazardous
wastes. To fulfill this responsibility, SHWRD
is (1) developing concepts and technology
for new and improved systems of solid and
hazardous waste land disposal; (2) docu-
menting the environmental effects of various
waste disposal practices; and (3) collecting
data necessary to support implementation of
disposal guidelines mandated by the Re-
source Conservation and Recovery Act of
1976 (RCRA), PL 94-580. SHWRD is also
collecting data on existing construction
technologies and applying these techniques
to the containment of pollutants emanating
from uncontrolled dump sites. The latter is
being done to assist in the implementation
of the Comprehensive Environmental Re-
sponse, Compensation and Liability Act of
1980 (CERCLA), PL 96-510. This paper pre-
sents an overview of the land disposal
aspects of the SHWRD Hazardous Waste
Program Plan and reports the current status
of work in the following areas:
A. Landfills
1. Pollutant generation
2. Pollutant movement
3. Pollutant control
4. Pollutant treatment
B. Landfill Alternatives
1. Surface impoundments
2. Underground mine disposal
C. Uncontrolled Sites and Remedial
Action
D. Cost and Economic Assessment
Technical Resource Documents
for Hazardous Wastes
Norbert B. Schomaker,
U.S. Environmental
Protection Agency
EPA is preparing Technical Resource
Documents (TRD's) to aid permit officials
responsible for hazardous waste landfills,
surface impoundments, land treatment fa-
cilities, and piles. These documents describe
current technologies and methods for evalu-
ating the performance of the applicant's
design in the areas of liners, leachate
management, closure, covers, and water
balance. The TRD's are basically a compila-
tion of all of SHWRD's research efforts to
date, and then are being published or
developed to assist in the implementation of
the regulations concerning hazardous waste
disposal facilities. The RCRA Guidance
Documents being prepared by the Office of
Solid Waste (OSW) will present design and
operating specifications that should comply
with the Design and Operating Requirements
and the Closure and Post-Closure Require-
ments in Part 264 of the regulations. The in-
formation and guidance presented in these
documents constitute a suggested approach
for review and evaluation based on good
engineering practices. Alternative and
equivalent methods may exist for conduct-
ing the review and evaluation, but if the
results of these methods differ from those
of EPA's method, they may have to be
validated by the applicant.
Sessions A-1 through A-3 —
Remedial Action
Current SHWRD Program in
Support of Superfund
Ronald D. Hill,
U.S. Environmental
Protection Agency
EPA's SHWRD is responsible for the con-
trol development program in support of
Superfund. The SHWRD research and de-
velopment program has been organized to
correspond with the Superfund legislation:
that is, the Oil and Hazardous Materials Spills
Branch deals with removal actions (emer-
gency), and the Disposal Branch deals with
remedial actions. The program includes
technology assessment to determine cost
and effectiveness, adaptation of technol-
ogies to the uncontrolled waste site problem,
field evaluation of technologies that show
promise, development of guidance material
for the EPA Office of Emergency and Re-
medial Response (OERR), and technical
assistance to OERR and EPA Regional
Offices.
The removal program is divided into three
major areas of activity: (1) personnel health
and safety, (2) demonstration of equipment,
and (3) chemical countermeasures. The re-
medial action program is also divided into
three major areas of activity: (1) survey and
assessment of current technologies, (2) field
demonstration and verification of tech-
niques, and (3) site design analysis. An over-
view of the removal and remedial programs
is presented.
Development of Methods for
In-Situ Hazardous Waste
Stabilization by Injection
Grouting
Philip G. Malone,
U.S. Army Corps of Engineers
Tests were made on four grouting
materials that might be used in sealing haz-
ardous waste sites to contain pollutants. The
object was to determine their ability to per-
form in the presence of selected waste solu-
tions simulating contaminated ground water.
The waste test solutions were made up to
contain a maximum of 10 percent by weight
of the chemical compound being tested.
Twelve chemical compounds typical of
materials found in industrial waste leachates
were included. Urethane and acrylate grouts
were relatively easily retarded to the point
where gelling did not occur. The most
chemically-tolerant setting reactions were
found in sodium silicate and Portland cement
grouts.
Samples of grout were exposed to the
simulated waste solutions for 20 days.
Sodium silicate and Portland cement grouts
proved to be the most durable.
Work is continuing on (1) further evalu-
ating the changes occurring in the grouted
material under various chemical environ-
ments and (2) producing a continuous seal
by injecting selected grout in closely spaced
holes in a sand test bed. Planning is under
way for a field test of sealing coarse-grained
materials.
Reactivity of Various Grouts
to Hazardous Wastes and
Leachates
Andrew Bodocsi,
University of Cincinnati
Recent research on clay liners used for
hazardous waste landfills indicates that their
permeability may increase considerably after
they are permeated by various organic leach-
ates. Concern over this observation has led
to the proposal of grouting the soils sur-
rounding such landfills as a remedial type of
containment. At present, not much is known
about the effects of hazardous leachates on
the permeability of grouted soils. Procedures
are presented for grouting test samples and
for testing the durability and the potential
long-term permeability changes of grouted
soil samples when permeated by hazardous
chemicals.
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Production, Migration, and
Hazards Associated with Toxic
and Flammable Gases at
Uncontrolled Hazardous
Waste Sites
David L. Nutini,
RNK Environmental, Inc.
The production, migration, and hazards of
toxic and flammable gases at uncontrolled
hazardous waste sites were determined by
a literature review. Study topics included (1)
volatilization and migration of gases (other
than methane), (2) short- and long-term gas
problems encountered before and during
remedial action and how these are coped
with, (3) costs associated with gas control,
(4) chemical group compatibility, and (5) the
most frequently reported toxic and flam-
mable gases occurring at uncontrolled haz-
ardous waste sites. The review indicates that
gas migration problems are site-specific and
manageable, with measured air concentra-
tions in the low mg/L to /^g/L range for most
gases reported. Costs of gas migration con-
trols are high and range from $17,300 to
$273,510.
Migration and Soil-Waste
Interactions of Industrial
Chemicals at Wilsonville, Illinois
R.A. Griffin,
Illinois State Geological Survey
Clay soil behavior and migration of in-
dustrial chemicals are being investigated at
a hazardous waste disposal facility in Wilson-
ville, Illinois (Macoupin County). The study
was initiated after the Illinois Supreme Court
affirmed a trial court order requiring the
wastes at this site to be exhumed and re-
moved. The May 1981 order provided a
unique opportunity to examine in detail the
effects of the wastes on soils below and ad-
jacent to the site and to measure the migra-
tion of contaminants from the trenches.
Work is currently in progress, but preliminary
results permit a detailed geologic description
of the site and a preliminary evaluation of
hydrogeologic conditions relative to contami-
nant migration, clay-organic chemical in-
teractions, and cover material susceptibility
to sinkhole formation.
Fabrication of Welded
Polyethylene Encapsulates to
Secure Drums Containing
Hazardous Wastes
S.L. Unger,
Environmental Protection
Polymers, Inc.
Corroding 208-L (55-gal) steel drums
holding hazardous wastes present a threat
to man and the environment, a threat that
is intensified in uncontrolled disposal sites.
To prepare such drums for secure and safe
transportation and disposal, a process was
developed to encapsulate them in polyeth-
ylene overpacks. Process features are
custom-designed polyethylene overpacks
and a friction welding apparatus to produce
seamless overpack seals.
The process provides a unique option for
encapsulating corroding steel drums with
polyethylene. Other means for encapsulating
drums with' polyethylene are expected to
yield products with poor properties because
of inferior overpack closures that cannot sus-
tain leak-tight conditions under stresses ex-
pected during use. Through friction welding,
encapsulates are sealed seam-free, and test
results show high mechanical performance.
In addition to seam-free closures, the encap-
sulates exhibit increased corrosion resis-
tance. Verification of corrosion resistance is
based on published work concerning poly-
ethylene. High performance of the closures
was confirmed by mechanical testing and
microscopic observation.
These improved characteristics are
estimated to be available at comparatively
moderate costs. The cost of polyethylene
overpacks is estimated to be competitive to
that of steel overpacks. A cost of $70 per
drum was projected for encapsulating
100,000 drums per year at an uncontrolled
disposal site.
Simplified Methods for the
Evaluation of Subsurface and
Waste Control Remedial Actions
S.M. Brown,
Anderson-Nichols Co., Inc.
A study was conducted to identify and
discuss available analytical and semi-
analytical solutions and simplified methods
for evaluating subsurface and waste control
remedial action technologies. These meth-
ods include those for (1) well hydraulics; (2)
drain hydraulics; (3) ground-water mound-
ing; (4) superposition; (5) equivalent sec-
tions, incremental methods, and corrections
for anisotropy; (6) conformal mapping; and
(7) contaminant transport.
Hand-held calculator and microcomputer
programs have been written for some of the
available methods. The advantages offered
by these programs are discussed, as are
some of the sources of available programs.
The simplified methods that are discussed
can be used by EPA and state Superfund
staff involved in reviewing remedial action
management plans and engineering feasibil-
ity studies. The methods can also be used
by site contractors to screen potentially feasi-
ble remedial action alternatives and, in some
cases, to conduct detailed analyses of alter-
natives and develop conceptual designs.
Costs of Remedial Actions at
Uncontrolled Hazardous Waste
Sites: Worker Health and
Safety Considerations
John M. Lippitt,
SCS Engineers
Estimating costs of remedial actions at
hazardous waste sites requires a determina-
tion of incremental costs for protecting
worker health and safety. This study was
designed to identify and estimate incremen-
tal health and safety costs for worker pro-
tection. Cost estimates were obtained from
five hazardous-waste-site cleanup contrac-
tors responding to six hazardous waste site
scenarios. Estimates were prepared for con-
ditions representing four degrees of hazard
per scenario. The cost impacts of extreme
temperatures were also estimated and are
presented along with the estimated costs for
considering health and safety in addition to
basic construction costs.
Evaluation of Systems to
Accelerate Stabilization of Waste
Piles or Deposits
Robert Fellman,
Envirosphere Company
Progress is reported on work performed
by the Envirosphere Company under sub-
contract to JRB Associates, Inc. (Contract
No. 68-03-3113), with EPA. The task was to
evaluate systems for accelerating stabiliza-
tion of waste piles or deposits. Results of the
7-month study concluded that from the array
of treatment methods and delivery/recovery
schemes available for in-situ subsurface ap-
plications, promising techniques include
enhanced flushing using surfactants, treat-
ment using biological agents, and hydrolysis
of waste materials. Oxidation of subsurface
waste materials does not appear promising.
Potential employers of in-situ subsurface
treatment systems are provided with tables
that relate site and waste characteristics to
the propriety of using a particular
reagent/delivery-recovery system.
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Sessions A-4 through A-6 —
Pollutant Assessment
Permeability of Compacted Clay
Soils to Solvent Mixtures and
Petroleum Products
K.W. Brown,
Texas A&M University
A study to determine the impact of
organic solvents and solvent wastes on soil
permeability is continuing. Pure solvent
chemicals, binary mixtures of pure solvents,
commercial petroleum products, and sol-
vent-rich industrial wastes have been studied
in fixed-wall compaction mold permeameters
in the laboratory and in solvent-rich industrial
wastes in field cells. Their permeabilities were
higher by several orders of magnitude than
those measured for water.
The higher permeabilities observed in the
laboratory occurred regardless of the hy-
draulic gradients applied. The higher per-
meability to polar organic liquids diminishes
as the organics are diluted with water, such
that mixtures containing more than 50%
water behave like water. Soils were also
more permeable to other organic liquids in
common use, including gasoline, kerosene,
diesel oil, and paraffin oil. Permeabilities to
these liquids were similar to those found with
organic solvents. Two commercially pre-
pared clays also demonstrated higher per-
meabilities to organic liquids than to water.
Effects of Hydraulic Gradient
and Method of Testing on the
Hydraulic Conductivity of
Compacted Clay to Water,
Methanol, and Heptane
David E. Daniel,
University of Texas
Permeability tests are being performed on
three compacted clays using three types of
permeameters — compaction-mold, consoli-
dation-cell, and flexible-wall. Hydraulic gra-
dients of 10,50,100, and 300 are being used.
The permeant liquids include water, meth-
anol, and heptane. Approximately one-third
of the tests are complete, with the remain-
ing tests scheduled for completion by
August 1984.
Results of tests on one of the soils (ka-
olinite) and two of the liquids (water and
methanol) indicate the following: (1) The
hydraulic conductivity of kaolinite to water
is about the same regardless of permeameter
type or hydraulic gradient; (2) when flexible-
wall or consolidation-cell permeameters are
used at hydraulic gradients of 100 and above.
kaolinite is twice as permeable to methanol
as it is to water; (3) when compaction-mold
permeameters are used at hydraulic gradi-
ents of 100 and above, kaolinite is 10 times
more permeable to methanol than to water;
and (4) hydraulic gradient has no significant
effect on flexible-wall permeameters, but it
may have an important effect in consolida-
tion-cell or compaction-mold permeameters,
where the trend is for decreasing hydraulic
conductivity with decreasing gradient. The
effects of side-wall leakage, applied stresses,
and degree of saturation are thought to
cause the differences observed with the
various types of permeameters.
Comparison of Column and
Batch Methods for Predicting
Composition of Hazardous
Waste Leachate
Danny R. Jackson,
Battelle-Columbus Laboratories
Inorganic and organic analytes were leach-
ed from four waste samples using batch and
column leaching methods. Leachate concen-
tration profiles were constructed from se-
quential leaching of waste with distilled,
deionized water using a combined solution-
to-waste ratio of 40:1. Leachate profiles
produced by the batch and column methods
were compared in terms of a fitted leaching
profile function and variation of the ex-
perimental data. Leachate profiles produced
by the two methods were significantly dif-
ferent for 12 of the 16 reported analytes.
Variation of experimental data, as repre-
sented by relative standard deviation, was
more than twice as great for the column
method as for the batch method. This result
was attributed to varying degrees of chan-
neling that may have occurred during leach-
ing of waste constituents using the column
method. The batch extraction method offers
advantages through its greater reproducibil-
ity and simplistic design, whereas the col-
umn method is more realistic in simulating
leaching processes that occur under field
conditions.
Use of Batch Adsorption
Procedures for Designing
Earthen Liners for Landfills
C.C. Ainsworth,
Illinois State Geological Survey
An investigation is being undertaken to
develop a batch sorption procedure and
scientific documentation for hazardous
wastes on soils and soil constituents. The
procedure will help evaluate the ability of
various earthen materials to attenuate haz-
ardous wastes. A very simple procedure has
been adopted and is now being tested as to
its flexibility, reproducibility, and usefulness.
The procedure will be revised and tested
using various soils from different parts of the
country. Soil-to-solution ratio; most effec-
tive mixing method, separation techniques,
and sample size are just some of the variables
that are being addressed in this investigation.
As each question is studied, the procedure
is revised and upgraded to reflect the data
obtained. In using this systematic approach,
the procedure will be well documented by
laboratory experimentation, and data will
hopefully be of use in critical evaluations of
the ability of an earthen material to attenuate
pollutants.
Organic Fluid Effects on the
Structural Stability of
Compacted Kaolinite and
Montmorillonite
Y.B. Acar,
Hazardous Waste Research Center
The effects of small particle sizes and the
surface force interactions in fine-grained soils
are manifested by a variety of interparticle
attractive and repulsive forces that strongly
influence the macroscopic engineering be-
havior and structural stability of compacted
soils. This paper presents the results of
studies to explain the post-construction
behavior of compacted soils in terms of the
properties of the individual components of
the system. Since organic leachates from
hazardous waste land disposal facilities are
of immediate concern, the study emphasizes
the static dielectric properties of organic
compounds as pore fluids and the activity
of the soil.
The results of studies on permeability and
pore size distribution indicate that changes
in hydraulic conductivity with organic fluids
are due to variations in the surface forces of
interaction. These changes in the interaction
forces are well reflected with changes in the
liquid limit and free swell of kaolinite. Such
simple classification tests with the leachate
are suggested for obtaining a qualitative
estimate of the expected changes in hy-
draulic conductivity of a soil.
Air Emissions of Volatile
Organic Chemicals from
Landfills: A Pilot-Scale Study
Louis J. Thibodeaux,
University of Arkansas
Volatile organic chemical emissions
through soils were examined through a com-
bination of vapor phase chemical transport
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models and a pilot-scale simulator. An ex-
perimental apparatus was built to simulate
landfill cell containing a liquid chemical in
re form. Models were used to determine
.e flux of the volatile chemical under various
conditions. A 50-50 mixture of methane and
carbon dioxide was used as a landfill gas
purge. The purge had varying effects on the
ability of the volatile chemical to diffuse
through the soil layer, depending on the
volatile chemical used. This paper discusses
the changes of chemical flux rates of se-
lected chemicals when a purge gas flow is
used.
State-Of-The-Art for Hazardous
Waste Surface Impoundment
Technology
Masood Ghassemi,
MEESA
Case studies of hazardous waste surface
impoundments (Si's) comparing actual and
projected performance can contribute sig-
nificantly to improving their design, con-
struction, and operation. To this end, the
available data for 22 Si's in the Southwestern
United States were reviewed, and six of
~hem were assessed further for a case study.
ie six Si's represent a range of industrial
aste types and volumes, ages, environ-
mental settings, liner types and designs, and
systems for leak detection and groundwater
monitoring.
The poor performances of several ponds
studied were attributed to lack of good pro-
ject planning during the design and construc-
tion phase. Failure to execute proper quality
assurance and control (QA/QC) procedures
during the project also contributed to failure
of these ponds. Deviations from desired liner
specifications and poor liner/waste com-
patibility testing resulted in poor perfor-
mance. For at least one site studied, poor
impoundment performance resulted from the
lack of rigorous site-specific investigations
to develop the basis for proper design and
construction.
The successful SI performance at one
facility is attributable to (1) use of a very im-
permeable clay as a liner material after ex-
tensive liner/waste permeability studies, (2)
use of competent design, construction, and
inspection contractors, (3) close scrutiny of
all phases of design, construction, and QA
inspection by the owner/operator, (4) ex-
cellent QA/QC and record keeping during all
phases of the project, and (5) good com-
munication among all parties involved in
stablishing the Si's.
Session A-7 — Land Disposal
and Treatment of Hazardous
Waste
Poster Presentations
The posters presented at the Tenth An-
nual Research Symposium are listed with
their authors, as follows:
1. Technical Considerations in Locating
Surface Impoundments and Landfills in
Low Permeability Soils
C. Clark Allen
Research Triangle Institute
Research Triangle Park, North Carolina
2. Field Verification of Air Emission
Models for Hazardous Waste Disposal
Facilities
W.D. Balfour
Radian Corporation
Austin, Texas
3. Technical Handbook for Stabiliza-
tion/Solidification Alternatives for
Remedial Action at Uncontrolled Haz-
ardous Waste Sites
M. John Cullinane, Jr.
U.S. Army Corps of Engineers
Waterways Experiment Station
Vicksburg, Mississippi
4. Applications of Engineering Fabrics at
Land Waste Disposal Sites
Raymond C. Horz
U.S. Army Corps of Engineers
Waterways Experiment Station
Vicksburg, Mississippi
5. Prepare Technical Resource Document
on Design, Construction, Mainte-
nance, and Evaluation of Clay Liners
for Hazardous Waste Facilities
G. Kingsbury
Research Triangle Institute
Research Triangle Park, North Carolina
6. Technical Handbook for Design and
Construction of Covers for Uncon-
trolled Hazardous Waste Sites
Colin McAneny
U.S. Army Corps of Engineers
Waterways Experiment Station
Vicksburg, Mississippi
7. Testing and Evaluation of Permeable
Materials for the Removal of Pollutants
from Leachates at Remedial Action
Sites
James E. Park
University of Cincinnati
Cincinnati, Ohio
8. Leachate Plume Migration Control
Edward Repa
JRB Associates
McLean, Virginia
9. In-Situ Treatment Techniques Ap-
plicable to Large Quantities of Hazard-
ous Waste Contaminated Soils
Ronald Sims
Utah State University
Logan, Utah
Sessions A-8 through A-9 —
Pollutant Control
Contaminant Fixation: Practice
and Theory Fixation
H.R. Lubowitz,
Environmental Protection Polymers
Data from a literature review are used to
describe and evaluate elements of hazardous
waste fixation. Factors are identified for pro-
ducing high-performance stabilized hazard-
ous wastes products that can prevent the
release of toxic contaminants to the environ-
ment. Some conclusions are drawn about
the performance of current stabilization
techniques. Suggestions are made for future
research.
Design, Construction,
instrumentation, and Monitoring
of a Multiple Soil Layer and
Hazardous Waste Landfill Cover
Richard C. Warner,
University of Kentucky
The design, construction, instrumenta-
tion, and monitoring of three multiple soil
layer landfill covers are described in detail.
The major scope of this research is to ascer-
tain the hydrologic balance of such a cover,
with emphasis on soil moisture movement
throughout the layered soil profile. The ex-
perimental design allows for the evaluation
of numerous alternative design options, in-
cluding alternative pervious drainage spac-
ing and leachate collection systems. The
construction phase of this project is pre-
sented in detail. Included are a comprehen-
sive analysis of the clay, sand, and topsoil
layers and of the drainage and subsidence
provisions of the experiment. A multi-layer,
multi-sensor soil moisture system using ten-
siometers, resistance block, thermocouples,
and the neutron probe is presented. Em-
phasis is placed on installation without
disturbing the effects of construction equip-
ment or the integrity of the multi-layer cover.
A tipping bucket system was designed to
measure surface ancUubsurface drainage to
within ± 0.5 percent of the actual discharge.
Calibration of resistance blocks yields a
log/linear relationship between resistance
and soil moisture content. The multi-sensor
approach provides a comprehensive data
base for multi-layer cover modeling used to
evaluate alternative designs.
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Estimation of Maximum Cover
Subsidence Expected in
Hazardous Waste Landfills
W.L. Murphy,
U.S. Army Corps of Engineers,
Waterways Experiment Station
The purposes of this study were (1) to
determine the maximum amount of post-
closure subsidence that will occur in a typical
hazardous waste landfill, (2) to estimate the
proportion of the subsidence contributed by
various landfill components, and (3) to de-
velop predictive techniques to estimate the
ultimate amount of cover subsidence. The
approach included analysis of various postu-
lated subsidence mechanisms and the ex-
amination of several actual landfills to
develop the characteristics of a represen-
tative landfill for model analysis. The analysis
involved a layered (drummed waste and in-
termediate clay cover), below-grade, closed
landfill. For the configuration and assumed
material properties, the maximum subsi-
dence was calculated to be about 10 to 11
percent, most of which results from the
closure of inherent cavities (e.g., space be-
tween drums). A much smaller part of the
subsidence can be attributed to compression
of the wastes after drum deterioration. It ap-
pears that the subsidence potential may be
substantially reduced by striving to fill the in-
terdrum space during operations.
Transmission rates can be calculated from
the data for various components of the
liquids.
Results of the pouch experiments show
the permeability of polymeric membranes to
water, some organic liquids (e.g., oils,
acetone, and xylene), organic dyes, and
hydrogen and hydroxyl ions, but not to other
inorganic cations and anions. The results
also indicate that the principal driving force
in transmitting the various species is the con-
centration gradient across the pouch wall
membrane.
With additional development the pouch
procedure appears to be a feasible and prac-
tical method for assessing the permeability
of membrane liners under conditions that
simulate some aspects of actual service and
for assessing the compatibility of a liner with
a specific waste.
The full report was submitted in fulfillment
of Contract No. 68-03-3131 by the JACA
Corporation under the sponsorship of the
U.S. Environmental Protection Agency.
Permeability Characteristics of
Flexible Membrane Liners
Measured in Pouch Tests
Henry E. Haxo, Jr.,
Matrecon, Inc.
Pouch experiments were used to examine
a variety of thermoplastic and partially
crystalline membrane materials for their
permeability to several waste and test liquids.
These liquids include aqueous salt solutions
(such as sodium chloride and lithium chlo-
ride), organic solvents (such as acetone
xylene), mixtures of acetone and water,
several waste liquids, and water-soluble and
organic-soluble dyes that have been used for
detecting leaks in membrane lining materials.
The pouch test involves sealing a quantity
of waste or test liquid into fabricated
pouches that are then immersed in deionized
water or other liquid. Permeation through the
pouch walls of constituents from either in-
side or outside the pouch is monitored by
weight changes in the pouch, chemical
analysis, pH and electrical conductivity of the
outer liquid, and the appearance of the dyes
in the outer liquid or on the pouch surface.
The EPA authors David M. Goertemooller and Naomi P. Berkley (also the EPA
Project Officer, see below) are with the Municipal Environmental Research
Laboratory, Cincinnati, OH 45268.
The complete report, entitled "Land Disposal of Hazardous Waste: Proceedings of
the Tenth Annual Research Symposium," (Order No. PB 84-177 799; Cost:
$22.00, subject to change} will be available only from:
National Technical Information Service
5285 Port Royal Road
Springfield, VA22161
Telephone: 703-487-4650
The EPA Project Officer can be contacted at:
Municipal Environmental Research Laboratory
U.S. Environmental Protection Agency
Cincinnati, OH 45268
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United States
Environmental Protection
Agency
Center for Environmental Research
Information
Cincinnati OH 45268
BULK RATE
POSTAGE & FEES
EPA
PERMIT No. G-
Official Business
Penalty for Private Use $300
ID) | (S fe ii
i.:::.P ~'..: 1984
Remedial Response
Section I
MEKL0097501
CHICAGO IL 60604
* U.S. GOVERNMENT PRINTING OFFICE: 1984-758-102/9!
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