United States
Environmental Protection
Agency
Municipal Environmental Research
Laboratory
Cincinnati OH 45268
Research and Development
EPA-600/S2-84-040 Mar. 1984
&EPA Project Summary
Geotechnical Quality
Assurance of Construction of
Disposal Facilities
S. J. Spigolon and M. F. Kelley
This report provides technical back-
ground for use by permittees, designers,
specifiers, quality assurance engineers,
and permit writers for hazardous waste
disposal facilities. The document ad-
dresses the quality control aspects of
construction, operation, and closure of
a hazardous waste disposal facility. (It is
assumed that the quality control aspects
of site selection, characterization, and
design have already been dealt with.)
The permittee's responsibilities dur-
ing construction, operation, and closure
of a hazardous waste disposal facility
are discussed with regard to four topics:
(1) geotechnical parameters that should
be tested or observed, (2) selection of
sampling plans and sample sizes for the
geotechnical parameters, (3) laboratory
and field testing methods for investiga-
ting geotechnical parameters, and (4) a
quality assurance program suited to the
unique responsibilities of the permittee.
Types of facilities covered by the
report include landfills (burial sites),
surface impoundments, waste piles, and
land treatment units. Land farms, injec-
tion wells, and seepage facilities are not
included.
This Project Summary was developed
by EPA's Municipal Environmental Re-
search 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 permittee of a hazardous waste
disposal facility maintains a relationship
with the regulatory agency that is unique
in the construction industry. During con-
struction, operation, and closure, the
permittee is responsible for design verifi-
cation, construction and operations, and
quality assurance inspection. That he is
responsible for both construction and
inspection poses a potential conflict of
interest. Thus complete inspection docu-
mentation is critical to (a) provide the
regulatory agency with confidence in the
project, and (b) provide a basis-in-fact in
case of future problems or litigation.
Background
The U.S. Environmental Protection
Agency (EPA) issued its interim final rules
and regulations for hazardous waste
disposal facilities in the Federal Register
on July 26, 1982. As stated in the
preamble, EPA wanted to make sure that
the issuance of a RCRA (Resource Conser-
vation and Recovery Act) permit for a
facility meant that a certain level of
protection was provided and that the
public could be assured that the pre-
scribed level of protection would be
achieved.
The act also provided EPA with the
authority to issue regulations covering
owners or operators of hazardous waste
treatment, storage, and disposal facilities
as necessary to protect human health and
the environment. Given this authority,
the EPA has chartered a defense strategy
with two basic elements: The first calls
for facility design and operating standards
that prevent groundwater contamination
by controlling the source of contamina-
tion, and the second is a groundwater
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monitoring and response program de-
signed to remove leachate from the
groundwater if it is detected.
The EPA believes that adequate protec-
tion will be afforded if hazardous waste
facilities meet both the technical per-
formance standards and the environ-
mental performance standards promul-
gated to execute their two-element
defense strategy. A quality assurance
program for the construction, operation,
and closure of a hazardous waste disposal
facility is not mandated by the current
regulations; but such a management
practice can ensure that the standards
are met, that the strategy is executed, and
that human health and the environment
are protected.
Scope of Study
The report is limited to consideration of
geotechnical tests and observations in-
volving physical properties of soils. Geo-
chemical and geohydrological tests such
as soil pH, ion exchange capacity, pore
water age, or infiltration capacity are not
included. The earthwork construction
industry does not commonly perform
geochemical or geohydrologic tests as
part of the quality control of construction.
But if such tests are deemed necessary by
the permittee's forces during construc-
tion, they certainly should be performed
on an as-needed basis. An example is the
need to verify an assumption made during
the design stage on a newly accessible
part of the site.
Although this report is restricted to
geotechnical parameters, most of the
concepts of sampling, inspection, quality
control, and documentation apply equally
well to site characterization studies,
geochemical or geohydrologic studies,
monitoring, and other site activities not
addressed.
This report is not intended to be a
textbook that teaches the fundamentals
of soil mechanics, soils testing, or statis-
tical methods to those engineers respon-
sible for geotechnical design. Rather, it
should provide both specialists and non-
specialists involved in the design or
evaluation of design (permit review) with
a common basis for understanding the
topics discussed here. The information
provided summarizes each topic, presents
the most pertinent features of each, and
provides terminology, definitions, equa-
tions, applications, and literature refer-
ences. For further study, or to acquire an
in-depth understanding of the various
topics, the reader is referred to several
textbooks on each topic.
Geotechnical Parameters
The permittee is responsible for the
quality of all geotechnical materials and
workmanship during the active life of a
disposal facility. This life includes both
the pre- and post-permit stages. The
geotechnical engineering aspects of both
phases require data on the engineering
properties of any soil and rock formations
that influence the project, both on and off
the site. Such materials include undis-
turbed in situ materials; excavated, trans-
ported, manipulated, and processed mate-
rials; natural nearby materials; natural
shipped materials (such as bentonite
clay); and manufactured shipped mate-
rials (e.g., geomembranes, geotextiles,
Portland cement, and asphalt cement).
The object of this section of the full
report is to identify the geotechnical
parameters that should be observed or
tested and documented during the con-
struction, operation, and closure of a
disposal facility. These parameters in-
clude water content, unit weight, specific
gravity, grain-size distribution, Atterberg
limits, consistency, and-compaction.
Given these values, several other index
properties may be calculated. These
include void ratio, porosity, degree of
saturation, plasticity index, and classifica-
tion by an acceptable soil classification
system. The soil index properties are good
indicators of the soil engineering proper-
ties used in design. Observations are
made and recorded on the aspects of
construction not amenable to formal
testing.
Selection of Sampling Plans and
Sizes
Because complete inspection of exist-
ing site media, materials, and workman-
ship is often impractical, samples must be
obtained and tested. This section of the
full report discusses sampling and testing
using statistical analysis terms, equa-
tions, and tables. The aim is to introduce
the topic as it applies to quality assurance
in hazardous waste disposal facilities.
Sample locations should be selected
randomly—either as a true random
sample per construction block, or as a
systematic sample with a random start.
Sample size is independent of block size;
it is a function only of confidence level,
maximum expected error, and block stand-
ard deviation. The statistical methods
presented are recommended because
they avoid the risks of relying on human
judgment with its potential for bias or
error. Conclusions derived by statistical
methods are conducive to review.
Standard Test Methods
Most of the sta ndard test methods use
to evaluate all of the soil index propertie
identified here are not commonly usei
because of time or equipment require
ments. Instead, acceptable alternative
are substituted. The full report discusse
the merits and limitations of the variou
test methods. Though certain method
may have time or cost advantages, ni
commonly used test method can be con
sidered totally superior to the others fo
the same index property. Hence none ar<
excluded from consideration.
Quality Assurance Program
Quality assurance includes all of th
planned and systematic actions per
formed by the permittee to provide con
fidence to the regulatory agency that th
disposal facility will perform satisfactorily
A quality assurance program, whethe
formal or informal, should be an Integra
part of the permit requirements.
In establishing a quality assuranc
program, the permittee should conside
the effect of several factors that aris
because of his unique construction
related responsibilities. These include th
identification of the workman, manage
ment, and inspector with quality, thi
quality system, the nature and cost of.
quality assurance program, the humai
factor, and the problem of scale.
The recommended quality assuranci
program includes a detailed plan of actioi
and a documentation program. The pro
ject records should include daily inspec
tion reports, test and observation dati
sheets, block evaluation reports, desigi
acceptance reports, and a project sum
mary. The documentation is intended ti
provide the necessary confidence to thi
regulatory agency about the quality of thi
facility.
Recommendations for
Further Study
This study has uncovered several gap;
in knowledge about this field. The follow
ing recommendations are made for fur
ther study.
Permit Writer's Guide
The present report is a technical re
source document. As such, it attempts tc
present thought-provoking discussions o
the various topics. In some instances, the
report merely identified the need, not th«
solution. Thus the logical outgrowth o
this report would be a permit writer's
guide.
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Rapid Compaction Control Test
Hazardous waste disposal facilities
share a problem with all other compacted
earthfill projects. Because the maximum
density and optimum moisture content
are very sensitive to variations in soil
composition, every field density should be
compared with a laboratory compaction
test curve developed from the same soil.
The time and effort involved are usually
prohibitive, however. The permeability of
a compacted clay liner depends heavily
on the soil being placed at or above
optimum moisture content, making the
determination of that value more impor-
tant than it is in conventional earthfill
work. Thus more study is needed on a
rapid method for field control of compac-
tion. A combination of the Hilf rapid
method and the Harvard Miniature Appa-
ratus may allow such rapid testing in the
field, especially if some rapid moisture
method (e.g., the Speedy device) is used.
Geomembranes and Gevtextiles
Designs for hazardous waste disposal
facilities can call for the use of geomem-
branes and geotextiles to achieve waste
containment, slope stability, trench cap
integrity, etc. But the permittee must
usually depend on independent laboratory
verification of the products to ensure that
they will conform to the standards they
are designed to meet. The accepted test
methods for the products apply only to
seam integrity. Except for the ponding
test, no accepted and commonly used
tests can determine the integrity of the
entire installed product and also lend
themselves to a quality assurance pro-
gram for the construction of a hazardous
waste disposal facility. This fact is especi-
ally significant given the poor perform-
ance history of these products.
Additional field data and analysis are
needed to evaluate the performance of
geomembranes and geotextiles used in
hazardous waste disposal facilities and
similar projects. Additional investigation
is also needed to assure the quality of
field test methods for these products.
To ensure the quality of geomembranes
and geotextiles brought onsite and to
avoid the prohibitive costs of verification
by independent laboratories, such prod-
ucts might be given a seal of approval by
an independent and creditable source.
This kind of verification is attractive and
has precedent, and it should be given
further consideratipn.
Geochemistry
Though geochemical considerations
are beyond the scope of this report, further
work is recommended in this area.
The following questions need to be
answered: What effects will the chemicals
hazardous waste disposal facilities
in
have on the soil and synthetic liners? And
what quality assurance procedures are
needed to address the geochemistry of a
hazardous waste disposal facility?
The full report was submitted in fulfill-
ment of Interagency Agreement No. AD-
96-F-2-A077 by the U.S. Army Water-
ways Experiment Station under the
sponsorship of the U.S. Environmental
Protection Agency.
S. J. Spigolon and M. F. Kelly are with the U.S. Army Waterways Experimental
Station, Vicksburg. MS 39180.
Robert Landreth is the EPA Project Officer fsee below).
The complete report, entitled "Geotechnical Quality Assurance of Construction
of Disposal Facilities," (Order No. PB 84-155 225; Cost: $17.50, 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:
Municipal Environmental Research Laboratory
U.S. Environmental Protection Agency
Cincinnati, OH 45268
U S GOVERNMENT PRINTING OFFICE, 1984 — 759-015/7622
3
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United States
Environmental Protection
Agency
Center for Environmental Research
Information
Cincinnati OH 45268
Official Business
Penalty for Private Use S300
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