WATER POLLUTION CONTROL RESEARCH SERIES • 16060 GRB 08/71
THE NATIONAL
GROUND WATER QUALITY
SYMPOSIUM
U.S. ENVIRONMENTAL PROTECTION AGENCY
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WATER POLLUTION CONTROL RESEARCH SERIES
The Water Pollution Control Research Series describes the
results and progress in the control and abatement of pollution
in our Nation's waters. They provide a central source of
information on the research, development and demonstration
activities in the Environmental Protection Agency, through
inhouse research and grants and contracts with Federal, State,
and local agencies, research institutions, and industrial
organizations.
Inquiries pertaining to V7ater Pollution Control Research
Reports should be directed to the Chief, Publications Branch
(Water), Research Information Division, R&M, Environmental
Protection Agency, Washington, B.C. 20^60.
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PROCEEDINGS
of the
NATIONAL GROUND WATER QUALITY SYMPOSIUM
Cosponsored by the
Environmental Protection Agency
and the
National Water Well Association
August 25-27, 1971
Denver, Colorado
Dedicated to C. E. Jacob (1914-1970)
Contract No. 68-01-0004
Project # 16060 GRB
For sale by the Superintendent of Documents, U.S. Government Printing Office, Washington, B.C. 20402 - Price $1.78
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EPA Review Notice
This report has been reviewed by the Environmental Protection
Agency and approved for publication. Approval does not
signify that the contents necessarily reflect the views and
policies of the Environmental Protection Agency nor does
mention of trade names or commercial products constitute
endorsement or recommendation for use.
ii
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FOREWORD
THE OBJECTIVE
by Jay H. Lehra
During the past decade, our nation's water problems have
been front page news across the country. Everyone is aware of our
tremendous surface water pollution problems, yet the threat to
our vast underground water resources remains remote to most of
the American public as well as to much of the scientific com-
munity.
With surface water resources decreasing in both quantity and
quality, ground water, as the primary alternate supply, must be
protected where it is pure, and improved where it is not. The
technology to accomplish most of these tasks should be made
available to the engineers, the architects, the planners, the
managers, and, of course, the ultimate users.
In an effort to focus public and scientific attention on the
broad and basic ground-water pollution problems, either present
or developing, the first National Ground Water Quality Symposium
was planned. Its objective was to
"bring together the nucleus of men, methods and ideas
capable of yielding solutions to problems which will
insure the protection and restoration of the quality of
our vast ground-water resources, whose development is
destined to double and perhaps triple in the coming
decade. It is intended that the published transactions of
the Symposium will serve as a guide to the State-of-the-
Art on ground-water quality."
In the following 211 pages, the reader should find that these
objectives were met in a most comprehensive and useful manner.
It is hoped that this manuscript will serve as a guide to potential
problems and workable solutions which must be intelligently
considered if our valuable resource is to be protected.
Executive Director, National Water Well Association, 88 East Broad
Street, Columbus, Ohio 43215.
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PROCEEDINGS OF THE NATIONAL GROUND WATER QUALITY SYMPOSIUM
Cosponsored by the Environmental Protection Agency and the National Water Well Association, August 25-27,
1971, Denver, Colorado. Dedicated to C. E. Jacob (1914-1970).
Contract No. 68-01-0004
TABLE OF CONTENTS
TITLE PAGE
iii FOREWORD-THE OBJECTIVE Jay H. Lehr
2 EPA'S ROLE IN GROUND-WATER PROTECTION Stanley M. Greenfield
7 THE CONTRIBUTIONS OF C. E. JACOB TO SCIENTIFIC
HYDROLOGY AND ENGINEERING WORKS Zane Spiegel
10 SUBSURFACE DISPOSAL OF LIQUID INDUSTRIAL WASTES
IN ALABAMA-A CURRENT STATUS REPORT William E. Tucker
20 SUBSURFACE STORAGE AND DISPOSAL IN ILLINOIS H. F. Smith
29 FEASIBILITY OF RECHARGING TREATED SEWAGE
EFFLUENT INTO A DEEP SANDSTONE AQUIFER Richard J. Schicht
36 BULL SESSION 1-GROUND-WATER WASTE DISPOSAL RECHARGE AND REUSE
45 PESTICIDE CONTAMINATION OF A SHALLOW BORED WELL
IN THE SOUTHEASTERN COASTAL PLAINS M. J. Lewallen
50 GASOLINE POLLUTION OF AGROUND-WATER
RESERVOIR-A CASE HISTORY D. E. Williams & D. G. Wilder
57 PETROLEUM CONTAMINATION OF GROUND WATER IN MARYLAND John R. Matis
62 BULL SESSION 2-CHEMICAL CONTAMINATION OF GROUND WATER
76 GROUND-WATER POLLUTION POTENTIAL OF A LANDFILL
ABOVE THE WATER TABLE M. A. Apgar & D. Langmuir
97 GROUND-WATER POLLUTION AND SANITARY
LANDFILLS-A CRITICAL REVIEW A. E. Zanoni
111 EFFECT OF EARLY DAY MINING OPERATIONS
ON PRESENT DAY WATER QUALITY L. L. Mink, R. E. Williams,
& A. T. Wallace
121 BULL SESSION 3-SOLID WASTE-ITS GROUND-WATER POLLUTION POTENTIAL
136 METHODS OF GEOLOGIC EVALUATION OF POLLUTION
POTENTIAL AT MOUNTAIN HOMESITES James P. Waltz
144 NITRATE IN GROUND WATER OF THE FRESNO-CLOVIS
METROPOLITAN AREA, CALIFORNIA Kenneth D.Schmidt
159 THE USE, ABUSE AND RECOVERY OF A GLACIAL AQUIFER Edward M. Burt
167 BULL SESSION 4-AQUIFER PROTECTION AND REHABILITATION
182 A SYSTEMS APPROACH TO MANAGEMENT OF
THE HANFORD GROUND-WATER BASIN D. B. Cearlock
193 SALTY GROUND WATER AND METEORIC FLUSHING OF
CONTAMINATED AQUIFERS IN WEST VIRGINIA Benton M. Wilmoth
201 PROBABLE IMPACT OF NTA ON GROUND WATER W. J. Dunlap, R. L. Cosby,
J. F. McNabb, B. E. Bledsoe,
& M. R. Scalf
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ERA'S ROLE IN GROUND-WATER PROTECTION3
by Stanley M. Greenfieldb
The Environmental Protection Agency's mission with respect
to the nation's ground-water resources is not explicitly mentioned
in the laws under which our predecessor agencies operated, nor is
it mentioned in President Nixon's reorganization plan and message
to Congress in July 1970 announcing the establishment of this
new Agency.
It did not need to be mentioned specifically. It is implicit in
all the water quality laws carried out by the Federal Water Pollu-
tion Control Administration and the Federal Water Quality
Administration. It is implicit in the various public health laws
under which the old Bureau of Water Hygiene established recom-
mended standards for drinking water and gave technical assistance
to municipal water-supply systems throughout the country.
Here is what the President said in his message to Congress in
1970 proposing the establishment of EPA: "Our national govern-
ment today is not structured to make a coordinated attack on the
pollutants which debase the air we breathe, the water we drink,
and the land that grows our food. . . For pollution control pur-
poses, the environment must be perceived as a single, interrelated
system. . . The sources of air, water, and land pollution are inter-
related and often interchangeable. . ."
"This reorganization," the President continued, "would per-
mit response to the environmental problems in a manner beyond
the previous capability of our pollution control programs. The
EPA would have the capacity to do research on important
pollutants irrespective of the media in which they appear, and on
the impact of these pollutants on the total environment. . . This
consolidation of authorities would help assure that we do not
create new environmental problems in the process of controlling
existing ones."
I think that is clear enough for anyone to understand. Water
is water—a basic natural resource, whether it is on or under the
Presented at the National Ground Water Quality Symposium in Denver,
Colorado, August 25-27, 1971 (sponsored jointly by the Environmental
Protection Agency and the National Water Well Association).
"Assistant Administrator for Research and Monitoring, Environmental
Protection Agency, Washington, D. C. 20460.
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surface of the earth. The nation's waterways, used for transport,
industrial cooling and processing, recreation, and a host of other
purposes, are surface waters; and a large part of our environmental
protection efforts are to restore and maintain surface-water
quality. But ve are not limited to surface water. This would be
absurd. A substantial portion of our total water is underground; in
many parts of the nation the only water resource is underground.
And the line of demarcation between ground and surface
water is indistinct. It's not a line but a continuum, variable from
place to place and time to time. Ground water becomes surface
water and vice versa. Both are parts of the same system, the
hydrosphere.
There's an analogy here with the atmosphere. Ground water,
especially the least-known portions that are deeply buried and
move very slowly, can be likened to the stratosphere, which mixes
very slowly with the troposphere below it, and in which pollutant
gases or particles have very long residence times and slow fall-out.
Yet in the recent public debate and discussion over possible
pollution of the stratosphere by the supersonic transport plane,
neither side argued that the thin upper regions of the atmosphere
were too high up to be of environmental concern!
Ground-water quality is a legitimate concern of EPA, as this
Conference demonstrates. It is probably true that lack of specific
mention of ground-water resources perse in the laws and executive
proclamations on which EPA is based has caused us to give
ground-water problems less attention than other aspects of the
environment during the first nine months of our official existence.
This is an oversight—if you could call it that, perhaps "lack of
emphasis" would be a better term—which we intend to remedy.
I endorse heartily the statement issued in October 1970 by
the then Commissioner of the FWQA, on the disposal of wastes by
subsurface injection—deep-well disposal. That policy order was
clear and brief: two typed pages. After noting the increasing use
of deep-well disposal of hazardous wastes, the risk of contamina-
tion pathways, the order put the FWQA on record as opposing
such waste disposal "without strict controls and a clear demonstra-
tion" that such disposals will not harm "present or potential sub-
surface water supplies ... or otherwise damage the environment."
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The order then went on to list seven criteria to be "critically
evaluated" for all proposals for deep-well injection:
1. Alternative disposal methods have been explored and
found less satisfactory in environmental risk.
2. Appropriate preinjection tests have been made to allow
prediction of what will happen to the wastes.
3. There is "adequate evidence" to show that the injected
wastes will not interfere with present or potential resources and
will not produce "other environmental hazards."
4. The best practical measures of waste pretreatment have
been applied.
5. The injection system has been designed and built in the
best possible manner.
6. Provision has been made for "adequate and continuous
monitoring" of both the injection operation and its environmental
effects.
7. The well will be plugged "below present or potential"
water resources whenever its use is discontinued.
These seven caveats appear to give perfect protection. But
they contain some circularities, some "weasel" words.
What constitutes "adequate evidence" that there will be no
pollution?
Preinjection tests must "allow" prediction of what will
happen to the wastes, but how reliable must these predictions be?
And how long a time must they cover?
Pretreatment is obviously not as good as complete treatment,
so why call it "best"?
How can alternative measures of disposal ever be considered
"less satisfactory" in terms of environmental protection, when
complete detoxification and neutralization of the pollutant is
included as an alternative? How can we neglect to consider such
complete treatment as an alternative?
What constitutes "adequate and continuous monitoring"?
And when a disposal is sealed off, does the monitoring continue?
How long?
The FWQA policy statement concludes with a ringing
declaration that we recognize all subsurface injection as a
temporary means of disposal, to be abandoned when better
methods are developed, giving greater environmental protection.
There appears to be a kind of schizophrenia here.
Waste materials that we dare not release to that part of the
environment we know the most about-the air, surface waters, and
the top layers of the land-can be safely contained by pushing
them farther down, where our knowledge of fluid movements and
physical and chemical and biological changes is very scant indeed.
It is just such out-of-sight, out-of-mind attitudes and actions that
have brought about our present pollution problems.
To say "this is only a temporary expedient till we find a
better disposal method" just glosses over the unpleasant truth that
we are doing things we have condemned in others.
There is a parallel in the current concern over dumping wastes
at sea. It has long been assumed that if you take the stuff out far
enough and sink it deep enough, no harm will result-that the
oceans are so voluminous they can dilute anything to innocuous
levels. The Irish poet, Oliver Gogarty, 75 years ago expressed it
thus: "And up the back garden, the sound comes to me of the
lapsing, unsellable, whispering sea."
We know that he was wrong; the sea is soilable. The earth's
crust is soilable too, and vulnerable to damage by man's activities.
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not only in ways that we may predict and make allowance for,
but also in unexpected ways.
For example, the problems of liquid waste injection are not
simply of a geological and hydrodynamic nature. The problem of
the thermal and chemical fate of the waste materials should have a
major role in determining the areas and amounts of allowed
disposal.
The result of not considering the chemical-heat problem
was demonstrated when the Hammermill Paper Co., in Erie,
Pennsylvania, began operating a sixteen hundred foot well in a
dolomite formation. Approximately fifty-five thousand barrels
per day of spent sulfite liquor containing a fiber, titanium dioxide,
clay and lignin-like compounds were pumped into the well at
pressures of eleven to thirteen hundred pounds per square inch
between 1964 and 1968. When the well blew up, one hundred
fifty thousand gallons per day of waste were spewed into Lake
Erie. Apparently the well blew when the injection tubing corroded
and the underground pressure was released to the casing.
The most dramatic instance of unexpected problems, of
course, was the apparent stimulation of earthquakes in 1962 and
1963 and again in 1964-66 by the injection of liquid wastes two
miles below the Rocky Mountain Arsenal near Denver, Colorado.
Less dramatic—but probably more important in the long run—are
the instances of gradual but massive changes in ground-water levels
and ground-water quality by mining, by oil and gas drilling, by
saline water injection, and also by pumping up ground water faster
than its natural recharge rate.
Just as the cure of schizophrenia begins with recognizing that
we have the disease, so there is great therapeutic value in candidly
acknowledging that protecting the nation's ground water, and
deep-well waste injection are likely to collide.
They are not mutually exclusive, however, any more than
septic tank sewage systems are mutually exclusive with surface-
water quality. Both can co-exist with the proper controls. If the
soil is of the right type and is not overloaded, the physical,
chemical, and bacterial processes will completely purify the sewage
and maintain the quality of the surface water.
Our specific problems with deep-well injection are: first, how
to identify and classify areas of safe injection so that fresh water
aquifers are not encroached; second, how to determine what
volumes of wastes can be injected safely; third, how to establish
chemical standards on wastes to minimize the dangers of injection;
and fourth, how to monitor and record deep-well injections to
insure the engineering standards of their operation.
We have built up a considerable body of knowledge about
ground-water supplies, recharge times, flow rates, and the fluctua-
tions that can be expected over long periods of time. We need to
know a lot more, of course, but we should not denigrate the
knowledge we have, which has been vital to our existence.
We have long experience with deep-well injection—tens of
thousands of injection wells in oil and gas fields, for instance-
both for the disposal of unwanted brine and for the stimulation of
flow from wells that have been depleted.
This long experience, however, has not been properly moni-
tored in the sense expressed in the FWQA criteria previously
mentioned. Oil men, in general, have been concerned only with
getting rid of the stuff. When they put it back in the same zone
from which they extracted the oil and gas, there is little change
in the fluid gradient; the natural dynamic conditions are at least
partially restored. But I am informed that the current and
increasing practice is to return the brine to some other zone—
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usually the shallowest available salt-water aquifer—from which the
chance of migration into fresh-water aquifers or surface waters is
great. This has already happened in certain parts of Texas and
Oklahoma. It doesn't happen immediately but over a considerable
period, maybe years after the injections start, so it is hard to
trace and to establish the cause.
Arthur Piper of the U. S. Geological Survey has suggested
the possibility that the noxious chemical wastes whose injection
triggered the earthquakes at Denver might eventually migrate
eastward to outcrops and ground-water source areas in Nebraska,
hundreds of miles away. Piper said that might take several
thousand years. He expressed the hope that "over that space and
during that time the waste will have been rendered harmless by
sorption, dispersion, and degradation. . . Data for assessing the
hazard definitely are neither at hand nor readily obtainable. . .
For the most persistently noxious wastes, a responsible society
cannot knowingly create even a remote hazard."
It seems to me that the Denver earthquakes—and similar, less
intensively studied cases in oil fields in western Colorado, Texas,
and Utah—have served a very good purpose in alerting us to this
kind of long-term danger. There's nothing like an earthquake to
arouse public interest! And we need public interest if we are to
get support for the research needed to find out what happens
down there in the dark and the heat and the pressure.
We in EPA have a clear call to study, test, and evaluate all
aspects of the ground-water environment. This includes, but is
not limited to, the use of that environment as a depository for
wastes.
Our research and monitoring efforts will be designed to
complement and not conflict with those of the Geological Survey,
NOAA, and other governmental agencies, both State and Federal,
that are concerned with land and water use.
Above all we will need basic research in what happens to
water and other fluids down there in the dark and the heat and the
pressure.
To accomplish this task, we must take full advantage of the
myriad of talents and resources that are available at the universi-
ties, in the States, in other Federal agencies, and in the private
sector. This Symposium has resulted from our association with
Dr. Lehr and the National Water Well Association. It has proven to
be one with many worthwhile aspects. It has collected those in the
field of ground-water resources who in their infrequent idle hours,
I am sure, have resolved many problems and found new approaches
to those yet unresolved. I think this gathering will go a long way to
show collectively the importance of sound water resources de-
velopment and more importantly the need for protecting our vast
underground supplies of fresh water. Perhaps by our association
with those of you working with the day-to-day aspects of ground-
water management, and our association with the diverse member-
ship of the National Water Well Association, we can achieve that
most important goal in research—the goal of transferring technol-
ogy from the laboratory to those who must ultimately make it
work. !f it has made a start in that direction, then this Symposium
has most assuredly been successful.
A while back I quoted an Irish poet on the sea. Now I'd like
to quote another Celtic bard, the Welshman, Dylan Thomas: "The
force that drives the water through the rock, drives my green age."
We need to know a lot more than we do about the force that
drives the water through the rock. If we are to have a "green age"
for ourselves and our posterity, we need pure and abundant water
in the ground.
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The Contributions of C. E. Jacob to
Scientific Hydrology and Engineering Works
by Zane Spiegel
ABSTRACT
C. E. Jacob was the first of a small group of hydrol-
ogists who followed C. V. Theis' lead in application of the
theory of nonsteady boundary value problems to both well
hydraulics and regional ground-water movement. Some of
his scientific contributions were the explanation of the
storage and elastic properties of artesian aquifers, the semi-
log method of aquifer test analysis, methods of analysis of
tests on unconfined leaky aquifers, application of doublet
theory to paired polarized heat-pump wells, the theory of
step and constant-head aquifer tests by wells, salt-water
encroachment, the tutelage of hydrology students at several
universities, solutions to hundreds of field problems en-
countered in his extensive consulting activities in many
parts of the world, and his method of determining aquifer
recharge and transmissivity from the response of water
levels in wells to varying natural recharge. One of his last
works was a study of the natural recharge to Southampton
on Long Island, which showed that the recharge was much
less than the 21 inches per year assumed previously.
I would like to acknowledge the cooperation
of several of C. E. Jacob's clients and close associ-
ates in the preparation of this paper, among them
C. V. Theis, Stan Lohman, John Ferris of the U.S.
G.S., and Bill Guyton, formerly of the U.S.G.S.,
and especially to Bettie Morgando of the firm of
C. E. Jacob and Assoc., who is still working very
hard for the firm to take care of all the details
involved in settling his business affairs.
The purpose of this Symposium, as stated on
the cover of our Program Guide, is "to bring
together a nucleus of men, methods and ideas
capable of yielding solutions to problems which
must be solved to insure the protection and
restoration of the quality of our vast ground-water
resources, . . . " C. E. Jacob has already provided
the means to solve many of our problems, if we
could look at his many reports, particularly in his
last twenty years of consulting.
C. E. Jacob began his career in ground water
with field experience with the U. S. Geological
Survey. Assisting R. M. Leggette, he made detailed
studies of water level changes in the complicated
aquifer systems of Croton Valley and Long Island,
New York. This work gave him the practical experi-
ence needed to arouse his scientific interest in
learning and then explaining the physical and
Presented at the National Ground Water Quality
Symposium, Denver, Colorado, August 25-27, 1971.
bGround-Water Hydrologist, P. O. Box 1541, Santa
Fe, New Mexico 87501.
mathematical basis of observed phenomena. He was
the first of a small number of hydrologists who
followed the lead of C. V. Theis in applying the
theory of nonsteady boundary value problems to
both well hydraulics and regional ground-water
movement, in the English language.
In his first five years of experience, several
important papers were published on the storage
and elastic properties of aquifers in coastal plain
sediments. These properties had been recognized
qualitatively by Theis previously, but Jacob pro-
vided the first quantitative explanation of artesian
storage, related this explanation to the tidal and
barometric effects noted by others, first recognized
the effects of railway trains on water levels, and
later coined the term "storativity" which unified
storage concepts. As a result of his detailed ac-
quaintance with highly permeable areas of Long
Island and Texas, Jacob was the first American
hydrologist to connect the fact that natural fluctu-
ations in water levels of wells are the best indi-
cators of rates of recharge to aquifers with the
theory of nonsteady boundary-value problems, to
give a direct method for determining both the true
recharge rate and the average effective transmissivi-
ty. This method requires the selection of only one
assumed or independently determined value—the
specific yield. Perhaps due to man's natural inclina-
tion to be more concerned with disturbances caused
by himself than with those caused by natural
phenomena, Jacob is best remembered for his con-
tributions to understanding of storativity, the
interpretation of the extremely valuable semi-
logarithmic plots of pumping tests, and the general-
ization of Theis' model for aquifer test analysis to
tests on unconfined and leaky artesian aquifers, and
to step tests and determination of effective well
radius. Interchange of ideas with more experienced
Survey hydrologists such as Theis, Lohman, Ferris,
and Guyton contributed greatly to the success of
his early research. An example of the value of this
kind of interaction was the 1952 publication by
Jacob and Lohman of a solution to the constant-
head well problem which is useful in areas of
flowing wells. His ability in mathematics permitted
coordination with the ideas of Muskat and Hubbert
developed in the petroleum industry.
Twenty-five years before a logical terminology7
and system of consistent units were agreed to by
the profession, Jacob was appointed by Stan
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Lohman to chair a subcommittee of the American
Geophysical Union to improve usage of the term
permeability and its units. Many of the sub-
committee's recommendations in 1946 were finally
adopted by another committee chaired by Lohman
after many thousands of students and self-taught
hydrologists had labored with the ridiculous system
Jacob and others had tried so long to improve.
The end of his first fifteen years of remarkable
original contributions to hydrology was marked in
1950 by publication of the well-known chapter on
"Flow of Ground Water" in the treatise "Engineer-
ing Hydraulics." This work summarized the results
of most of his original work to that date. A large
proportion of this important work was his original
work.
Some of the important topics of that work
were (1) a brief exposition of Darcy's Law correctly
stated in terms of hydraulic head, not pressure, in
a form similar to that of Hubbert's correction of
one of the many unfortunate fallacies in hydrology;
(2) a discussion of the range of validity of Darcy's
law, (3) the difference between the terms permea-
bility and transmission constant; (4) the velocity
potential; (5) derivation of differential equations
and their relation to boundary-condition equations;
(6) the range of validity of steady radial-flow
equations; (7) the effect of a well on a uniform
flowfield, (8) recirculating pairs of wells (doublets)
and well-stream systems; (9) the general theory of
images; (10) specific capacity; (11) the superposi-
tion theorem; (12) tidal fluctuations; (13) well
characteristics; (14) effects of a well between two
parallel streams; and (15) adjustments for uncon-
fined flow.
The next few years (the early fifties) are
notable for the large number of important studies
that were made, not so much by himself, but by his
colleagues and students, on various types of well
models and on more detailed aspects of the
correlation of precipitation and ground-water levels
on Long Island. These years were especially im-
portant for the beginning of publication of an
astounding number of papers on well hydraulics
and stream-connected flow by Prof. Mahdi Hantush,
Jacob's most renowned former student.
After 1947, as ground-water consulting be-
came Jacob's dominant activity, formal publication
of important discoveries waned, but his character-
istic custom of attacking a practical problem with
new methods continued. Engineers, like Cipolletti,
have been honored by having structures they de-
signed named after them, but the great engineering
works that benefited from Jacob's analyses in his
last twenty years have neither his name nor a
surface expression, and for many of the works,
even his reports are only obscure sections of large
8
tomes by the engineering firms to which he
rendered able assistance.
Much of Jacob's work was done as a "con-
sultant's consultant," wherein he provided a broad
knowledge of ground-water principles and a phe-
nomenal ability to solve problems. Most of his
work can be classified in categories such as (a) the
effects of a given water-supply development; (b) the
mechanism and effects of mine drainage; (c) the
effectiveness of drainage by wells; (d) well injection
procedures; and (e) the control of uplift pressures
near dams.
The scientific contributions contained in many
of these reports may some day be considered as im-
portant as those of his first fifteen years of hydro-
logic contributions. Jacob developed a form for his
major consulting reports that might well be taken
as a model by consultants in many fields. Typically,
these reports contained a synopsis giving his impor-
tant conclusions; a concise statement of the prob-
lems and the circumstances which led to his
involvement in them; a section on the important
physical principles on which his analyses were
based, with detailed references, many of which
were his own; definitions of special technical terms
used in the report; a concise summary of the
geographic, geologic and hydrologic aspects of the
problem; and finally the hydrologic core of the
report, which frequently contained significant orig-
inal contributions to scientific hydrology or engi-
neering practice. In addition, it was his practice to
add detailed appendices of the basic data on which
he based his conclusions.
The detail and originality of Jacob's treatment
of all the sections of his consulting reports can be
fully appreciated only by reading these reports. I
hope that some day a complete catalog of his works
can be made available to the hydrologic profession,
and that the full reports will eventually be made
available for reference. Many of the consulting
reports have already been released for public use,
and efforts are being made to obtain the release of
the others. New Mexico Institute of Mining and
Technology in Socorro, New Mexico, has been
designated custodian of these important contribu-
tions. The task of cataloguing Jacob's works for
general library use is an enormous effort, far be-
yond the present resources of New Mexico Tech.
If, during these three days, an effort to obtain
additional support for this task can be initiated, the
dedication of this Symposium to the memory of
C. E. Jacob will take on a new meaning.
One of the most interesting characteristics of
Jacob's wide range of consulting reports was the
emphasis which he put on a careful description of
the long-range effects of each project with which
he was associated. This emphasis was undoubtedly
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due to his recognition that neither the public nor
his clients were generally aware of the inevitability
of diversion of streamflow by wells, the far-reaching
effects of wells in slightly leaky aquifer systems,
and the effects of aquifer nonhomogeneity on the
rate of movement of contaminants. His understand-
ing of hydraulic effects in complexly layered aqui-
fers led him to conclude in several reports on both
agricultural and mining problems that drainage
works were more effective if installed in deeper
semiconfined beds than in the shallow aquifers that
ultimately were to be dewatered. This concept was
applied in the Yuma area to reduce the number of
wells needed to accomplish a given depth of
drainage.
The great magnitude of effects of many of the
projects which Jacob studied inevitably has brought
about considerable controversy, or at least concern,
as to the public welfare. For example, the economy
of the entire country of Israel is dependent on the
validity of computations made on the basis of
Jacob's theories; enormous costs are at stake in
the drainage of the Indus Valley in West Pakistan;
international relations may be affected by the
success or failure of the Yuma drainage project in
southern Arizona, along the Mexican border.
Through many years of activity in problems of
production of fresh water in areas underlain by
salt water, Jacob recognized that future generations
would be faced with enormously serious shortages
of fresh water. As a result of this foresight, in 1965
he patented two improved methods for producing
fresh water from wells. Negotiations are in progress
by Jacob's estate to develop and test these
patented methods.
In recent years possibly one of the most
significant contributions to society made by the
hydrology profession was a report on "Evaluation
of Potential Impact of Phosphate Mining on
Ground-Water Resources of Eastern North Caro-
lina," prepared by a Board of Consultants of which
Professor Jacob was Chairman. The report, made
for the North Carolina Department of Water Re-
sources in 1967, is typical of Jacob's reports in
form and content. While the report contains a
standard application of the well-accepted tech-
niques of basin-wide engineering analysis, based on
his own leaky-aquifer theory, it also contains one
special feature that distinguishes it from most other
reports of this type—a review of certain aspects of
water law, with a recommendation for the enact-
ment of State legislation establishing a permit
system for all new large uses of ground water.
As a direct result of this report by Jacob's
Board of Consultants, the North Carolina General
Assembly enacted the "Water Use Act of 1967,"
which requires a permit from the State for large
diversions of surface or ground water in any area
previously declared to be a "capacity-use area."
The legislation follows Jacob's recommendations
closely. The rapid action of the North Carolina
General Assembly in adopting Jacob's recom-
mendations is evidence of the clarity and forceful-
ness of the report.
One of Jacob's last consulting reports (Decem-
ber, 1968) was an extension of earlier work by
himself and Boris Bermes, a former student at the
University of Utah, in which he applied variations
of his important nonsteady mathematical model of
water-level fluctuations to Southampton, a penin-
sular portion of Long Island. Using a value of
specific yield that had been determined by detailed
U.S.G.S. studies in a nearby area, he computed
values of average annual recharge ranging from 8 to
14 inches per year, substantially lower than the
previously accepted value of 21 inches per year that
had been based on very rough estimates. Although
engineering consultants working on similar prob-
lems in central and eastern Long Island had rejected
Jacob's method and conclusions, the basic data
available for similar areas of Long Island, southern
New Jersey, and Cape Cod confirm Jacob's con-
clusions. Detailed analysis of all the factors affect-
ing recharge have revealed valid reasons for the
lower values he computed. Re-evaluation of Jacob's
1945 recharge computation for central Long Island
on the basis of a revised specific yield of 0.25 gives
a recharge value of 16 inches per year, correlative
with those determined from Jacob's later South-
ampton work. Revised ground-water outflow com-
putations, based on transmissivity values deter-
mined by correct applications of Jacob's semilog
and leaky aquifer methods of analysis, and by
refinements of Jacob's methods by Hantush, cor-
roborate the conclusion that Long Island's recharge
(and hence natural discharge) is much closer to
Jacob's value of 16 inches per unit area than to 21
inches per unit area per year, based on the con-
venient roundness of the ratio 21 to 42 inches of
precipitation. The implications of a twenty percent
overestimate of the natural water supply are
enormous, when it is recalled that water-supply
projects do not generally contain any factor of
safety, and millions of people may depend on the
consequences of a rough estimate.
In the final analysis, it may come to pass that
Jacob's real contribution will be recognized to be
the foundation which he laid for a greater social
awareness of the importance of water in our future
life, by the combined effects of all his scientific
and engineering studies. No matter what you or I
do to attempt to solve these problems, no real
solution will be attained without this social aware-
ness by ourselves and the public.
9
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Subsurface Disposal of Liquid Industrial Wastes
in Alabama—A Current Status Report"
by William E. Tuckerb
ABSTRACT
Four subsurface disposal wells have been drilled and
completed in Alabama. These are: Stauffer Chemical Com-
pany, Mobile County; Ciba-Geigy, Inc., Washington County;
U. S. Steel Corp., Jefferson County; and Reichhold Chemi-
cals, Inc., Tuscaloosa County. The Geological Survey of
Alabama has been directly involved in all four projects.
The Survey served as a consultant to the Alabama Water
Improvement Commission, the State agency responsible for
protection of surface and ground water in Alabama, on the
Stauffer and Ciba-Geigy projects, and as consultant and
supervisor on the U. S. Steel Corporation and Reichhold
Chemicals, Inc., projects. These projects were undertaken
as a research effort to insure that the responsible State
agencies are fully cognizant of all aspects of this method of
waste disposal. It is a policy in Alabama that subsurface
disposal is permissible for some wastes if the well is properly
designed and completed in an appropriate geologic environ-
ment and if conventional methods of waste treatment have
been evaluated and proved to be inadequate.
The Stauffer well, operating at 75 gallons per minute
and 500 psi, is the only subsurface disposal system, other
than oilfield brine disposal wells, that is currently in opera-
tion. The Stauffer and Ciba-Geigy wells are in the Coastal
Plains geological province and the U. S. Steel and Reichhold
Chemicals, Inc., wells are in Paleozoic sediments of the
Warrior Basin. A general discussion of the geology, drilling,
completion, and testing techniques is presented for the
two geologic provinces involved.
INTRODUCTION
The transition of Alabama in the last ten years
from a raw material producing State to a manu-
facturing State has placed an increasing burden on
our water resources. In 1965, the State legislature
amended the Water Improvement Commission Act
creating an agency to protect the surface- and
ground-water supplies of our State and removing
the grandfather industries from exemption. The
Geological Survey of Alabama is authorized by the
legislature to conduct studies on the occurrence
and availability of surface and ground water. This
responsibility has been expanded to consider water
Presented at the National Ground Water Quality
Symposium, Denver, Colorado, August 25-27, 1971.
"Geological Survey of Alabama, P. O. Drawer O,
University, Alabama 35486.
usage and the environmental impact of industrial
and population evolution. The Survey serves as a
consultant to the Water Improvement Commission
in the fields of geology, hydrology, and geologic
engineering.
As subsurface disposal of industrial waste be-
came popular in the middle 1960's, the Survey
undertook research projects to determine any and
all aspects of this method of waste disposal. To date
the Survey has served as regulatory supervisor on
three wells and directed the total program on two
wells. In January, 1971, a general policy was
adopted by the Alabama Water Improvement Com-
mission regarding subsurface disposal in Alabama.
The general policy approved of this method of
disposal provided that all other methods had been
examined and exhausted; and geologic and hydro-
logic conditions exist such that the environment is
protected to the maximum extent possible.
Application for a subsurface disposal system
in the form of a feasibility study is made to the
Alabama Water Improvement Commission. The
Geological Survey reviews the material presented
and makes its own recommendation to the Com-
mission. If the plan is approved, the applicant is
allowed to drill and test the well. The applicant
then applies for permission to utilize the well and
information gathered while drilling and testing is
reviewed by the Survey and further recommenda-
tions regarding use, requirements, and monitoring
procedures are prescribed. So far, five subsurface
disposal wells have been drilled and completed in
accordance with this policy. These are: (1) Stauffer
Chemical Company at Mobile; (2) Ciba-Geigy at
Mclntosh—2 wells; (3) U. S. Steel in Birmingham;
and (4) Reichhold Chemical in Tuscaloosa (Figure
1).
GENERAL GEOLOGY
In order to form a geologic frame of reference,
the State can be divided into three major geologic
provinces. These are: (1) the Crystalline area in
east-central Alabama, (2) the Warrior Basin in
northwest Alabama, and (3) the Coastal Plains in
10
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O OILFIELD
. INDUSTRIAL
Fig. 2, Generalized cross section of north central Alabama.
Fig. 1. Disposal wells in Alabama.
Fig. 3. Generalized cross section of south Alabama.
south and southwest Alabama. A cross section
through the Warrior Basin exhibits sedimentary
formations ranging from Pennsylvania!! to Cambri-
an in age. Disposal horizons are chiefly available in
the Ordovician and Cambrian Ordovician by virtue
of secondary porosity in the form of fractures and
solution cavities. A cross section through the
Coastal Plain area exhibits sedimentary rock from
Miocene to Jurassic age with disposal horizons
available in all formations by virtue ot intergranular
porosity in sandstones and secondary porosity in
limestones and dolomites.
The Stauffer and Ciba-Geigy wells are in the
Central Gulf Coastal Plain geological province and
the easternmost extension of the Mississippi Interi-
or Salt Dome Basin. Most o! the geologic structures
found in Lower Cretaceous or younger sediments in
this basin are the result of movement of the under-
lying Louann Salt. Salt at depth, responds as a
plastic medium and will move into zones of weak-
ness in response to sediment loading. Structures
formed as positive features by salt swells or domes
and as collapse-type features such as grabens where
salt was removed occur in southwest Alabama
(Figure 4).
The most prominent structural features within
the salt basin in southwest Alabama arc the
Hatchetigbee anticline, the Jackson rault-Klepac
dome, the Mobile graben, and the Giihertown-
Coffeeville-West Bend. Pollard and Bethel fault
zones. Other important structures are the domal
anticlines at Citronelle, South Carlton and Chntom
and the piercement salt dome at Mclntosh.
A complex, north-south oriented fault system
known as the Mobile graben extends fn>ni Jackson
Alabama, south to Mobile Bay. The Jackson tauli is
the northernmost fault on the east flank of the
graben system. It is down thrown to the wev and
in the subsurface exhibits approximateK 5,(>uo teet
of throw at a depth of 2,450 reel where it was
penetrated by the Champion Klepac No. l well
drilled by Humble Oil and Refining fomuanv in
1955. The large amount ot displacement probably
resulted from subsidence as salt was being removed
to supply domal growth of the Klepac dome on the
upthrown site.
-------
Fig. 4. Major structural features in Alabama.
The major taulr representing the west flank of
the grabcn opposite the Jackson fault has never
been penetrated. It is possible that the northern
part of the Mobile graben is only a half-graben
where the Jackson fault comprises the east flank
of a structural low.
Farther to the south, faults representing both
east and west flanks of the graben have been
mapped. The graben, as determined from existing
well control, turns westward north of Mobile Bay
and can be projected into Mobile County west of
the Bay.
The Mclnrosh salt dome in Washington
Count}' is the shallowest piercement salt dome in
the Mississippi Interior Salt Dome Basin. The dome
pierces Miocene sediments within 410 feet of the
surface of the ground and is approximately 1 mile
in diameter. There is little or no well control for
structurally mapping radial and peripheral faulting
commonly associated with the piercement salt
dome. The location and conliguration of the rim
synciine immediately adjacent to or surrounding
the Mclntosh dome is interpretive. It is believed to
have been formed by subsidence above the area
where salt flowed toward the center of the salt
dome.
The deposits of Late Cretaceous age in Ala-
bama crop out in a crescent-shaped belt across the
12
central part of the State. In western Alabama these
beds dip southwestward and, in ascending order,
include the Tuscaloosa Group, which comprises the
Coker and Gordo Formations; the McShan and
Eutaw Formations; and the Selma Group, which
comprises the Mooreville and Demopolis Chalks.
the Ripley Formation, and the Prairie Bluff Chalk.
In eastern Alabama the beds dip southward and the
chalk formations of the Selma Group merge lateral-
ly into formations consisting chiefly of sand and
clay. Along the Chattahoochee River deposits of
Late Cretaceous age, in ascending order, are repre-
sented by the Tuscaloosa Group (undifferentiated),
the Eutaw Formation, the Bluff town and Ripley
Formations, and the Providence Sand.
The Upper Cretaceous Series includes two
important faunal zones, the Exogyra ponderosa and
the Exogyra costata, that can be traced throughout
the Atlantic and Gulf Coastal Plains. The Exogyra
ponderosa zone extends stratigraphically from the
Tombigbee Sand Member of the Eutaw Formation
almost to the bottom of the Ripley Formation, and
the Exogym costata zone extends from the top of
the Demopolis Chalk to the Prairie Bluff Chalk.
The Tertiary formations in Alabama consist
predominantly of marine elastics, and are transi-
tional in character between the clastic and largely
nonmarine formations of Mississippi and the car-
bonate rocks of the Florida peninsula. In Alabama
the Paleocene, upper Eocene, and Oligocene forma-
tions grade into limestone; one of the lower Eocene
formations grades into limestone downdip in the
subsurface; and the middle Eocene formations
become increasingly calcareous eastward. Alabama
and northwestern Florida are included in the
eastern part of the North Gulf Coast sedimentary
province characterized by clastic deposits chiefly,
in contrast to the carbonate anhydrite fades in the
Florida peninsula sedimentary province (Toulmin,
1955).
The U. S. Steel and Reichhold Chemicals, Inc.,
wells are in Paleozoic formations. Geologically, the
Reichhold plant site is located in the Black Warrior
sedimentary basin. The Black Warrior is a wedge-
shaped basin extending across Alabama and Missis-
sippi and contains considerable thickness of clastic
and carbonate sediments. The basin is a negative
feature bounded to the north by the Nashville
dome, to the east and south by the ridges and
thrust faults of the Appalachian front, and extends
to the west into the State of Mississippi.
The geologic structure in most of the Black
Warrior basin is fairly simple, with formations
generally dipping to the south or southwest. In
Alabama, the salient structure existing in the Black
Warrior basin is the Sequatchie anticline. This anti-
-------
cline, a.' subsurface extension of one of the Ap-
palachian foreland ridges, plunges beneath the
surface in Blount County, Alabama, and probably
extends far to the southwest, perhaps as far as the
Mississippi State line. The Sequatchie anticline in
the subsurface has been referred to as the Blounts-
ville or Browns Valley anticline. The Sequatchie
anticline passes beneath Tuscaloosa County, but
the axial trend fades out and cannot be traced on
the surface beyond the eastern half of the county.
Semmes (1929) shows the anticlinal axis turning
south in Tuscaloosa County, but detailed structural
mapping supporting this trend is not included in
his report. The existence of an unconformable
Cretaceous veneer over the western part of the
county prohibits the use of Pennsylvanian outcrops
in tracing the trend of the anticlinal axis. Moreover,
thickening of Pennsylvanian sediments to the
southwest along the direction of axial plunge of
the anticline coupled with the unconformity exist-
ing at the Mississippian contact may tend to mask
the trend of the Sequatchie anticline in the older
and deeper sediments, from reflection in the
Pennsylvanian.
Semmes (1929) shows the Warrior syncline,
the complimenting structure to the north of the
Sequatchie anticline, trending northeast to south-
west with the axis passing a few miles east of the
city of Tuscaloosa. For the reasons given previous-
ly, it is possible that the main structural axis of
both the Sequatchie anticline and the companion
Warrior syncline extend to the southwest as far as
the Mississippi State line with the dominant struc-
tural expression existing in pre-Pennsylvanian sedi-
ments. If this is the case, the anticline may pass
north of the city of Tuscaloosa, and not be re-
flected strongly in Pennsylvanian age rock.
Detailed mapping of the coal beds of the
Pennsylvanian sequence indicates that minor fold-
ing and faulting is widespread in sediments of this
age in the basin. Anticlinal trends are local and tend
to disappear rapidly. Faults show small displace-
ment and are of limited areal extent. It is possible
that many faults are confined to the Pennsylvanian
and fade out before reaching the Mississippian. In
general, the magnitude of folding and faulting in
the Pennsylvanian decreases to the northwest away
from the major thrust faults marking the boundary
between the Black Warrior basin and the Appa-
lachian front.
The Birmingham anticline is the major struc-
tural feature in the Fairfield area. It is a breached,
asymmetrical anticline, trending northeast, under-
lain by limestones, shales, sandstones, chert, dolo-
mite and some iron ore seams. Rocks from
Cretaceous to Cambrian outcrop in the Fairfield
area, with Jurassic, Triassic, and Permian rocks
not being represented. The Mesozoic and Paleozoic
sediments generally dip to the southeast except
where folded or faulted.
Faults associated with the Birmingham anti-
cline include thrust faults, strike-slip faults, reverse
and normal faults, and relaxation faults. The geol-
ogy of the area is often complicated by the pres-
ence of so many folds and faults.
Near Vance, Alabama, the Birmingham anti-
cline plunges to the southwest and is overlain by
Mesozoic sediments of the Tuscaloosa Group.
NATURAL RESOURCES
The Coastal Plain of Alabama is the most
important ground-water producing area in Alabama.
The consistent occurrence of good water-bearing
sand and gravel beds make the development of
large-capacity wells quite common. Most out-
cropping sands in this area are considered good to
excellent aquifers. Water well depths vary from a
few feet to 1,700 feet and yields range up to over
1,000 gpm (gallons per minute). Well yields in the
Paleozoic vary considerably and, although topogra-
phy is important in locating a successful well, the
contributing factor for a high yield well is the
penetration of solution channels and cavities within
limestone reservoirs. Yields range from a few gal-
lons to several thousand gallons per minute (350 to
3,500 gpm).
The Citronelle Field, the South Carlton Field
and the Tensaw Lake Field are located in the area
of the Ciba-Geigy wells and the Stauffer well. Salt,
limestone, and lignite are other mineral resources
that are being developed or have potential as miner-
al deposits in the Coastal Plain.
Mineral resources in the area of the U. S. Steel
and Reichhold, Inc., wells are primarily iron ore,
coal, and limestone.
DISPOSAL WELLS IN ALABAMA
Stauffer Chemical Company Well
The Stauffer Chemical Company disposal well
was the first industrial subsurface disposal system
drilled and completed in Alabama. This well was
drilled to a total depth of 4300 feet, and eventually
completed through perforations at 3400 feet with a
tested injection rate of 420 gpm at a surface pres-
sure of 400 psi. This well has been in operation for
21A years without interruption, except for a remedi-
al acid treatment.
Ciba-Geigy Wells
The Ciba-Geigy Corporation has drilled two
subsurface disposal wells. The first well was drilled
to a total depth of 7500 feet and final completion
13
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has been effected at 3800 feet through a screen and
gravel pack. An injection rate of 420 gpm at 800
psi has been established for this well. The number
2 well was drilled to 2500 feet and completed at
2000 feet through a screen and gravel pack. Fresh
waters occur in this area to a depth of 600 feet.
Surface casing has been set on each of these wells
at approximately 1100 feet and cement circulated
to the surface. The number 2 well has an injection
capacity of 800 gpm at 300 psi.
Two wells have been drilled and completed in
the older sedimentary rock of north-central Ala-
bama. These were for U. S. Steel Corporation in
Birmingham and Reichhold Chemical Company in
Tuscaloosa. Both wells are of the open-hole com-
pletion type and penetrated the same rock units.
U. S. Steel Weil
The U. S. Steel well has an injection capacity
of 300 gpm at 600 psi surface pressure. The well
was drilled and completed to a total depth of 6,072
feet. All operations were under the direct super-
vision of the Geological Survey of Alabama as a
research project in the field of deep-well disposal
of aqueous wastes. The project was financed by a
research grant from U. S. Steel Corporation to the
Alabama Geological Survey. All steps taken in the
drilling and completion of the well were designed
for the protection of surface and subsurface water
resources and other natural resources of the area.
Electric logs, cores, drill stem tests, and in-
jectivity tests run during the drilling of the well
indicated the feasibility of completing the well as a
deep-well disposal system. The disposal horizon was
completed "open-hole" from 4,415 feet to 6,072
feet. The well was cased and cemented as follows-.
16" casing set at 64 feet —Cemented to surface
103/4" casing set at 1,100 feet—Cemented to surface
75/8" casing set at 4,415 feet -Cemented to 2,720
feet
27/8" injection tubing set at 4,434 feet
The results of injection tests indicate that
either of two zones have a sufficient capacity to
handle the present volume of pickling liquor waste.
The uppermost zone has the capacity of accepting
a greater volume-rate at a lower pressure than the
lower zone. The well is so constructed that the
lower zone would commence to take fluid in the
event the upper zone fails to function properly.
Injection tests run during and after the com-
pletion indicated the well's ability to receive fluid
without pressure build-up. The absence of pressure
build-up after extended injection indicates a sal-
aquifer of considerable areal extent and capacity.
The primary injection zone, 4,415 feet to
to 4,630 feet, is a fine grained, very calcareous
sandstone with shale laminations. Porosity and
permeability is present in the rock unit by virtue of
fractures. The zone of secondary importance,
5,550 feet to 5,770 feet, is a dolomite with frac-
tured porosity and permeability.
Due to the high percentage of carbonate ma-
terial in the sandstone and almost total carbonate
composition of the dolomite, consideration must be
given the reaction between the waste FeCl2 + HCL
or FeSO4 + H2 SO4 and the formation constituents.
Injection of waste HC1 effluent into a carbonate
formation will result in a dissolution of the soluble
parts of the rock and will cause an increase in
permeability, thereby increasing the injection rate
and/or reducing the pressure required. The reaction
products will be water, carbon dioxide, and calcium
chloride—the latter two being soluble in water.
Adversely, the pH increase resulting from these
reactions may cause Fe(OH)3 precipitate and pos-
sible plugging.
Fe+" + 3(OH)~ = Fe(OH)3 (gel precipitate)
Fe" + 2(OH)~ = Fe(OH)2 (precipitate)
In a sulfuric acid reaction with a carbonate
formation, the calcium released will be reprecipi-
tated as CaSO4 (anhydrite) or CaSO4 • 2H2O
(gypsum). The high iron content of the waste efflu-
ent (1.2 moles/liter) coupled with the pH increase
from mineral reactions will cause precipitation of
Fe(OH)3 gel.
There is considerable controversy among ex-
perts as to whether the precipitation resulting from
acid waste injection into a carbonate reservoir will
plug the pore space and reduce permeability.
Fortunately, experience has shown that low
strength acid waste may be injected into carbonate
strata. Hammermill Paper Company at Erie,
Pennsylvania, and Dupont at New Johnsonville,
Tennessee, have successfully injected acid waste in-
to carbonate strata.
From all indications, the porosity of the
injection zone in the subject well is fractured
rather than intergranular. This should prove more
favorable to acid injection because less surface area
is available for reaction, and the "zone of reaction"
should extend to a greater distance from the well
bore. Considering the two extraneous precipitates
caused by the reaction of H2 SO4 with a carbonate
compared with the HC1 reaction, it must be stated
that the HC1 reaction would be more compatible
with the salaquifer water and rock than the H2 SO4
14
-------
pickle liquor reaction. However, if the H2 SO4
pickle liquor was reduced in acid strength by dilu-
tion of 1 part acid to 1 part water or 1 part acid to
2 parts water, there is no reason why the well and
receptor formation should not function equally as
well.
Reichhold Well
The Reichhold well has an injection capacity
of 600 gpm at 700 psi. A generalized surface treat-
ment facility includes pretreatment filtration,
storage, further filtration and injection.
Initial feasibility and geological studies for the
Reichhold well were made by the Geological Survey
of Alabama and Deep Well Pollution Control Cor-
poration. The results of this study were presented
in a report entitled "Study of the Potential of Sub-
surface Disposal in the Tuscaloosa Area," dated
September 30, 1968. All aspects of the project were
under the direct supervision of the Geological Sur-
vey of Alabama as a research project in the field of
deep-well disposal of aqueous wastes. The project
was financed by a research grant from the Federal
Water Quality Administration and Reichhold
Chemicals, Incorporated. The objectives of this
phase of the project were to design and complete a
well that would assure protection of surface and
subsurface water resources and natural resources of
the area, and to locate a horizon in the deep sub-
surface formations that would be receptive to the
plant's waste effluent.
As in the case of the U. S. Steel well, electric
logs, cores, drill stem tests and injectivity tests run
during the drilling of the well indicated the feasibil-
ity of completing the well as a deep-well subsurface
disposal system. Permeability exists in two main
horizons in the well. The upper zone is from 6620
to 6670 feet and the lower zone is from 7036 to
7230 feet. The upper zone is sandstone, pale red
to light gray, very fine to fine grained, hematitic
in part, calcareous, and quartzose. The lower zone
is limestone, yellowish gray to very light brownish
gray, dense to crystalline dolomitic and sucrosic in
part. Permeability and porosity exist in both hori-
zons by virtue of natural fractures and cavernous
vugs.
Electric logs and drilling characteristics indi-
cate a highly fractured zone in the Floyd Shale in
the interval between 5070-5600 feet. A completion
in this zone should be considered as an alternative
should the lower two zones cease to function
properly. This interval is presently cased off and
cemented. A completion in this interval would
necessitate a secondary cement job and perfora-
tions throughout the injection horizon.
SPECIAL TECHNIQUES
During the drilling of a disposal well, a geolo-
gist constantly examines cuttings and maintains a
sample log. This information is used to determine
zones of importance in which open-hole drill stem
tests should be made. The drill stem tests provide
formation pressures, producing rates and a sample
of the reservoir fluid. Electric log techniques are
used extensively to evaluate the formations pene-
trated and to determine potential injection hori-
zons. The data collected while drilling the wells is
utilized to determine the casing and cement pro-
gram. Preliminary injection tests are conducted to
establish rates and pressures that will be utilized in
the design of surface equipment. A composite of
this information is made for a graphical presenta-
tion and exhibits the results of drilling and testing a
well. The most advanced logging techniques availa-
ble were utilized in Alabama.
These included the dual induction lateral log,
the borehole compensated sonic log, the formation
density log, sidewall neutron porosity log, radio-
active tracer log, and temperature log. Each of these
logs is also recorded on magnetic tape and com-
posited by computer in the form of a synergetic
log which is a continuous record of all formations
penetrated showing porosity, permeability, water
saturation, and lithology. The cement bond log is
useful in determining the amount ot cement fill-up,
and the degree of bonding between the casing and
the cement, and the cement and the formation.
WELL MONITORING SYSTEMS
BSffi
PRESSURE
]. Injection samples
2- injection tubing - icng string annuius
INJECTION RATE AND CUMULATIVE VOLUME
DRIP SAMPLES
TEMPERATURE
DENSITY
p
1
I
g
i
j
'
IS 1
— v. — '
5
^Tfff,
r5*
rFi
?
*3
•j
•i
i
i'
J
Fig. 5. Well monitoring systems.
Temperature logs and radioactive tracer logs are run
to determine the zone of entry of the injected fluid.
When the well is placed in operation, the well must
be monitored by continuous clock recorders, re-
cording pressure at the injection tubing, the annuius
)5
-------
between the injection tubing and long string and the
annulus between the long string and surface casing
(Figure 5). Injection rates and cumulative volumes
are recorded on continuous clock recorders.
MONITORING TECHNIQUES
Drip samples of the wastes are taken and
analyzed periodically. Temperature and density are
recorded on a continuous basis and corrosion tags
are analyzed periodically. Sample stations are set
up on surface streams and water-supply wells are
sampled periodically. Through an agreement with
the Air National Guard, aerial photos (color and
infrared) are made quarterly. An additional seismic
monitoring system has been added to the Reich-
hold well to study any possible effects that injec-
tion may have on the tectonic activities of that
area (Figure 6). The system consists of ten geo-
phones placed around the well. The geophones are
connected by a telephone service to a seismic re-
corder at the Survey office. Continuous films (16
mm) are made of seismic activities in the area.
These are transmitted daily to the U. S. Geological
Survey Earthquake Center at Menlo Park, Califor-
TKLEPHONE LINE
SEISMIC TELEMETRY BY FREQUENCY DIVISION-
MULTIPLEXING
Fig. 6. Seismic monitoring system.
nia, for analysis. Two monitor wells will be drilled
between the two injection wells at Ciba-Geigy and
completed in the lowermost fresh-water aquifer.
Samples from these wells will be analyzed peri-
odically for changes in chemical quality.
SELECTED REFERENCES
Bergstrom, R. E. 1968. Feasibility of subsurface disposal of
industrial waste in Illinois. Illinois Geol. Survey Circ.
426, 18 pp.
Craft, B. C, and M. F. Hawkins, Jr. 1959. Applied petrole-
um reservoir engineering. Prentice-Hall, Englewood
Cliffs, New Jersey, 437 pp.
Hartman, C. D. 1966. Deep well disposal at Midwest Steel.
Iron and Steel Engr. no. 12, pp. 118-121.
Healy, J. H., W. W. Rubey, D. T. Griggs, and C. B. Raleigh.
1968. The Denver earthquakes. Science, v. 161, no.
3848, pp. 1301-1310.
Henkel, H. O. 1955. Deep well disposal of chemical wastes.
Chem. Engr. Prog. v. 51, no. 12, pp. 551-554.
Louis Koenig Research. 1964. Ultimate disposal of ad-
vanced-treatment waste. U. S. Dept. Health, Educ.
and Welfare Environmental Health Ser. 999-WP-10,
146 pp.
Paradise, S. J. 1956. Disposal of fine chemical wastes. In
Industrial Waste Conf., 10th, 1955 Proc. Purdue Univ.
Ext. Ser. 89, pp. 49-60.
Semmes, D. R. 1929. Oil and gas in Alabama. Alabama
Geol. Survey Spec. Rept. 15, 408 pp.
Sheldrick, M. G. 1969. Deep well disposal: are safeguards
being ignored? Chem. Engr. April 7, pp. 74-78.
Talbot, J. S., and P. Beardon. 1964. The deep well method
of industrial waste disposal. Chem. Engr. Prog. v. 60,
no. 1, pp. 49-52.
Toulmin, L. D. 1955a. Cenozoic geology of southeastern
Alabama, Florida, and Georgia. Am. Assoc. Petroleum
Geologists Bull. v. 39, no. 2, pp. 207-235.
Toulmin, L. D. 1955b. Tertiary formations of west-central
Alabama. In Guides to southeastern geology. Geol.
Soc. America Guidebook, 1955 Ann. Mtg., New
Orleans, pp. 465-489.
Warner, D. L. 1965. Deep-well injection of liquid waste. U.
S. Dept. Health, Educ. and Welfare Environmental
Health Ser. 999-WP-21, 55 pp.
Warner, D. L. 1967. Deep wells for industrial waste injection
in the United States. U. S. Dept. Health, Educ. and
Welfare Water Pollution Control Research Ser. WP-
20-10, 45 pp.
DISCUSSION
The following questions were answered by William
E. Tucker after delivering his talk entitled "Sub-
surface Disposal of Liquid Industrial Wastes in
Alabama—A Current Status Report."
Q. We'd like to bear more discussion on whether
conventional methods of waste treatment have
been evaluated and proven inadequate. Example:
Brines can almost always be disposed of in more
conventional ways. Aren't we really speaking of
economics?
A. This particular brine is tremendously concen-
trated and, of course, I think economics definitely
fit into any of these systems. The present con-
ventional system, in this particular plant, has been
to store the brine in a lagoon for evaporation. And,
in an area where you have 53 inches of rain a year,
it doesn't evaporate very much, and, of course, is
inadequate. I'm not familiar with all of the chemi-
cal process techniques of separating brines—but
most consume a tremendous quantity of energy
creating other forms of pollution and, of course,
introducing the economic question again.
16
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Q. Are you monitoring the effects of ingestion of
acid wastes on the carbonate rock reservoir: and
how do you determine the compatibility of the
injection fluid with the reservoir fluid?
A. Well, this causes no end of concern in the U. S.
Steel well which will be a sulphuric acid injected
into the carbonate reservoir. You can duplicate it
in the laboratory with samples of the waste. When
you lower the pH, you start getting precipitation of
the sulphates. This is a problem that's in debate
throughout the country. In subsurface disposal
wells, will these precipitants harm the injection
well? There are some active sulphuric acid injection
wells that function perfectly well. But, when you
see those precipitants come out of solution in the
laboratory, it really scares you. We think that one
advantage at the U. S. Steel well is the fractured
system of porosity rather than intergranular poros-
ity. Of course, the rock material will be in contact
with the fluid, but it will eventually neutralize
itself at a greater distance from the well. An option
for that well, if precipitants clog the fractures, is to
change the pickling process to a hydrochloric sys-
tem and dispose of the WPL in the disposal well.
Q. How does the Alabama Geological Survey de-
termine and/or define the expression, ''appropriate
geologic environment, "and also how do you deter-
mine an inadequate treatment method which would
then indicate that you could—or should—consider
deep well disposal?
A. Well, the appropriate geologic environment is
determined by the knowledge of the subsurface
gained from data while drilling the well, reservoir
parameters, porosity, permeability, compatibility,
fractured gradients in the area, structural move-
ments—all these factors that I've tried to present in
the talk, are used to determine the appropriate geo-
logic environment. At the same time, the well has
to be mechanically constructed to conduct the
waste to the disposal horizon and protect the fresh
water resources. Each well is judged by its own
merits in an evaluation-type decision. We do make
laboratory compatibility studies of the waste efflu-
ent with the rock and with the formation water.
Q. Does the Alabama Geological Survey expect to
bear the cost of all monitoring of waste disposal
wells drilled in the future? And will detailed moni-
toring be done on all waste disposal sites?
A. Yes, we will bear the cost. This has been set up
in our operational budget, allocated by the State
Legislature. There are many areas, of course, where
matching funds and research funds are available to
help supplement these efforts. For instance, the
seismic study and monitoring on the Reichhold is
being financed by the USGS. The Environmental
Protection Agency paid 23.3% of the toral cost of
the well and funds were budgeted for 5 years of
monitoring the well. Detailed monitoring will be
utilized on all waste disposal wells.
Q. Comment on the need for rehabilitation of
waste disposal wells—how often might you have to
do this and what methods might you use7
A. Typically, we think our monitoring procedures
will turn up times that remedial work will be
necessary. The Stauffer well was in operation for
about two years before it required a remedial acid
job to clean up the perforations. This is typical for
a brine disposal well in an oil field or a producing
well in an oil field.
Q. Regarding the chemical reaction between acid
waste and carbonate rock, how about the produc-
tion of CO2 and its effect on formation pressures?
A. Since we are operating at 3,000 or 4,000
pounds pressure, most of the CO: will be in solu-
tion of formation fluids and spent acid water.
Sometimes this reduces viscosity. CO: is not gener-
ally a problem unless the pressure is such that it
comes out as solution.
Q, Will there be publications describiiig -;;:Lse dis-
posal holes, or disposal wells, or general informa-
tion on the disposal program.?
A; Yes, we have in preparation a State-wide report
on subsurface disposal which the Survey hopes to
be able to release this fall.
Q. How do injection rates compare between the
Stauffer well, which was perforated—presumably
with a jet perforation system—and the gravel
packed Ciba-Geigy well? Do you see any problems
involved with jet perforation for any injection well,
especially in larger diameter wells in the 16 to 20
inch size?
A. The Ciba-Geigy gravel-packed well presents
higher injection rates at lower pressures. Of course,
you get pressure drops, cross perforations because
cf friction loss. If the conditions are suitable. I
think perhaps the enlarged hole, under-reamed prior
to gravel packing, presents mechanically the best
systems. In some cases, this is not practical, and
incompetent formations will continually cave in
and slough off into the well. The perforating tech-
nique doesn't lend itself very readily to, say, an acid
injection. You would have acid in contact with
the metal causing undue corrosion unless you used
some type of exotic alloy steel.
Q. Have you noted any decline in injection capaci-
ty on the one well that's been in operation for a
couple of years?
A. It did decline up to the remedial acid job, and
the acid job restored the well to its former capacity.
17
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Q. For wells in which you are disposing of acid,
and using a cement grout to seal the casing, this
might readily dissolve—that is, some cement grout
might readily dissolve if leaks develop. Why not use
inert, or acid-resistant grout?
A. Correct. In some cases, we use a resin-type of
cement—that is, acid-resistant. Most often it is best
to complete the well in such a manner that the
waste will never be in contact with the cement.
You may have noticed on the gravel-packs and
open-hole completion that the waste is going down
below the casing and cement and this prevents it
from coming in contact with the cement. Some of
the cement used is high density of about 15 or 16
pounds per gallon and it has a lot of nonreactive
material in the cement. But, there are resin cements
available, plastics that can be used if the situation
develops.
Q. The sense of this question asks whether hydro-
chloric acid is, in fact, a waste that could not be
handled at the surface with conventional treatment
techniques and, if that is true, then why is the
decision made to use a disposal well for handling of
bvdrocbhiric acid?
A. We would greatly encourage all industries to
recover whatever products they can off of a waste
stream I think this is an area that will be the
eventual solution to most of our waste problems.
We have one steel industry in Alabama that has a
hydrochloric acid pickling system and they reclaim
all of the acid. This is, of course, the ideal solution—
to restore and renew your waste. The U. S. Steel
well will dispose of 125 gallons per minute of
sulphuric acid, which is about 10 percent active.
This is a tremendous amount of potentially useful
material, and while these wells are in operation, we
hope to continue to encourage companies to
restore their waste. But, I think it is just something
that will happen down the road quite some time
off.
Q. In the case of a State agency directed well
disposal system for an industry, who hears the
responsibility for possible contamination, the State
or the industry?
A. I imagine that would get into a pretty hairy
legal situation. We were wearing the unusual hat of
a consultant or prime contractor on these two jobs
and I assume that the usual liability the contractor
has for a completed project would exist.
Q. What do you hope to see from air photo and
infrared methods with regard to monitoring and
injection systems and, an allied question, why do
you want to fly side looking radar for monitoring?
A. South Alabama, the Mobile area, of course has
quite a few fault systems. We don't know for sure,
but we think these faults are sealed as evidenced by
the nature of the sediments, but we found these
particular photographs very useful in our part of
the country for picking out fracture traces, fault
and joint systems and lineation on the surface. We
have flown a side looking radar on hydrologic
problems and were able to locate fault systems. If a
subsurface disposal system has any possibility of
leaking along fault planes we would like to know
where. We feel that the infrared will show up the
areas of tree kill or vegetation destruction. Because
they are flown on a periodic basis we have a con-
tinuous historical record.
Q. Two questions related to economics: first, what
was the approximate cost to the industrial clients of
deep disposal well planning and completion, and
the other question—what are some typical costs of
the disposal wells mentioned?
A. In the case of the U. S. Steel well, the Survey
received $30,000 for its participation. The cost of
the well, including that $30,000 was approximately
$240,000. On the Reichhold well, the total cost of
the well was approximately $300,000 and the Sur-
vey received $50,000 for their participation. These
figure out to approximately $30 a foot. This would
compare closely with oil and gas drilling and com-
pletion in the same area. Oil and gas wells in this
area usually run $10 to $15 a foot for a completed
well, but they don't take quite the pains in testing
and coring and sampling and logging. We used
practically every tool available to the oil industry
in our work. So, that's one factor that increases the
cost.
Q. Another one related to a former subject: have
you had any complaints from consulting engineer-
ing firms about the Geological Survey of Alabama
acting as a consultant in this way? Would some
type of consulting by the State Survey be permis-
sible outside Alabama and, lastly, did Alabama's
Attorney General render an opinion on this?
A. So far, we haven't had any complaints. I
noticed Jack Talbot was in the auditorium and he
is in this type of business, but he hasn't com-
plained. Actually we have worked closely with
consultants to the mutual benefit of both parties. 1
don't think we'd be interested in doing outside
work, except contributing our experience to the
state of the art. In fact, I doubt if it would be
permissible for us to do otherwise. We did receive
an Attorney General's opinion on this subject. Our
legislative act enables the Survey to study all
phenomenon associated with geology so we are
given a pretty broad area of operation. The philoso-
phy behind our being involved in this is that the
18
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wells we were involved in were considerably re-
moved from an area of active oil and gas explora-
tion. It was in an area where the nearest explora-
tory well was 75 miles away, and we felt that we
were more suited, knowing outcrops and knowing
the stratigraphy, than perhaps a consulting firm
from out of State. There are two more areas
within the State where we would like to drill
subsurface disposal wells. Again they are areas that
we don't have much subsurface information about.
Very likely we will be involved in those two
projects, but I think it will end after that.
Q. Do you have a monitoring system that will
identify leaks early in the stage by monitoring over
the injection zone, rather than waiting until a leak
might be serious enough to come up to hit an
aquifer which you are monitoring?
A. None of the wells are presently set up to do
that. We feel that we can use the pressures and
injection rates, pressure fall-off curves and things
like that to determine if there is a leak anywhere
and these are recorded on time charts which are
analyzed continually and irregularities will show
up in the pressure recordings.
Q. This, incidentally, was done by a geologist
working in Colorado and he raises a good point.
They have had to fuss with this for awhile. Has
there been any noticeable seismic activity related
to any of your disposal wells?
A. No, there has not. I think I might have misled
you on the seismic monitoring of the Reichhold
well. That well is not in operation at this time. We
are recording historical data prior to the actual
injection of waste into that well. This should occur
about the first of 1972. As far as seismic monitor-
ing is concerned, the Reichhold well will be our
main area of study—the seismic activity caused by
the injection into the Reichhold well. We do not
have seismic monitoring capabilities around the
other wells in the State.
19
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Subsurface Storage and Disposal in Illinois
byH. F. Smith b
ABSTRACT
The storage of both liquids and gases in underground
strata has become rather common in Illinois.
The problem of disposal of fluid industrial wastes has
caused greatest concern, especially for the possible effects
on ground-water quality. Necessary precautions have been
established in the requirements of the Illinois Environ-
mental Protection Agency (IEPA) which has authority to
control, prevent, and abate pollution of streams, lakes,
ponds, and other surface and underground waters in the
State. Before any construction can begin on storage in
subsurface strata, a permit must be secured from the IEPA.
Eight basic design policies have been adopted that have to
be met before a construction permit will be issued.
Sandstone, limestone, and dolomite are the basic
lithologies most commonly considered as potential disposal
reservoirs in Illinois. From well cores of such formations,
essential laboratory studies are conducted defining the rate
of fluid movement, porosity, and permeability of the rock
and the pressure distribution within the aquifer.
Plugging of the injection horizon is the most serious
cause of damage to a fluid injection system and results from
the forming of an impermeable deposit on the well bore or
plugging in the formation itself. In either case the plugging
may result from a number of listed causes.
To date there have been four industrial waste disposal
wells in Illinois. Variation in conditions is illustrated by
these cases of disposal wells that have been authorized by
the State.
The first practical use of underground gas storage in
Illinois was at Waterloo in 1950. Since then, the number of
projects and their capacities have grown continuously. At
the present time there are 24 underground gas storage
projects. Gas injection pressures must be kept below the
fracturing pressure of the caprock. In underground gas
storage reservoirs in Illinois, injection pressures of approxi-
mately 0.55 psi per foot are often used.
Secondary recovery by water flooding accounted for
73.4 percent of the total oil production in Illinois during
1968. In that year there were 880 active projects in Illinois
with 13,107 water injection wells that injected 2581 million
gallons of water.
INTRODUCTION
The storage of both liquids and gases in sub-
surface strata has become rather common in Illi-
nois. These practices include: (1) storm water
runoff with storage for only a few days, (2) arti-
ficial recharge for several months, (3) natural gas
for a season, (4) brines for an indefinite period, and
(5) industrial wastes for permanent disposal.
Presented at the National Ground Water Quality
Symposium, Denver, Colorado, August 25-27, 1971.
''Head, Hydrology Section, Illinois State Water Sur-
vey, Box 232, Urbana, Illinois 61801.
The problem of disposal of fluid industrial
wastes has caused greatest concern, especially for
the possible effects on ground-water quality. Neces-
sary precautions have been established in the
requirements of the Illinois Environmental Protec-
tion Agency, which has authority to control,
prevent, and abate pollution of streams, lakes,
ponds, and other surface and underground waters
in the State.
As the State Legislature and the Federal
Government, encouraged by conservation agencies,
tighten controls on surface disposal and enforce
existing legislation, the problem of fluid waste
disposal will become considerably greater in the
future.
The first major industry that was faced with
high volumes of fluid waste disposal was the
petroleum industry, which produced large quanti-
ties of salt water with their crude oil.
The petroleum industry's solution to the
restriction of surface disposal was to initiate injec-
tion of brines into suitable subsurface strata.
Pollution of streams and potable water re-
sources by industrial wastes including brines pre-
sents a great hazard. Every year there is an increase
in industrial water consumption, and a correspond-
ing rise in fluid waste that must be disposed of.
Liquids, gases, and liquid wastes in reasonable
quantities probably can be safely injected into the
underground strata, if such operations are responsi-
bly managed with adherence to rigid standards.
Deep injection waste disposal is no more than
storage in underground space of which little is
attainable in some areas and which is exhaustible in
most areas (Piper, 1969). These and other problems
are reflected in the following descriptions of the
policies in effect and the existing installations and
proposed projects in Illinois.
SUBSURFACE WASTE DISPOSAL
Before any construction can begin on storage
in subsurface strata, a permit must be secured from
the Illinois Environmental Protection Agency. Be-
fore the issuance of a permit for a particular facili-
ty, the Board requires the submission of such plans,
specifications, and other information as it deems
relevant and necessary. The general procedure
followed is that the interested industry prepares a
comprehensive feasibility report and submits it to
20
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the Board's Technical Fecretary for review and
comment, and if satisfactory, receives tentative
approval subject to the submission of final con-
struction documents for the proposed test wells
prior to drilling. The following basic policies have
been adopted:
(1) All zones to be considered for disposal
must contain brine waters having over 10,000 mg/1
total dissolved solids. This equates to a 1 percent
solution of total dissolved solids. Fresh water is
now defined as water of 10,000 mg/1 or less total
dissolved solids. A figure of 5000 mg/1 or less had
been used until recently to define fresh water, but
this was revised upward to preserve ground waters
that may be usable if and when current experi-
mental methods of desalination are made practical
for the production of potable water from brackish
waters.
(2) There must be an effective and adequate
impermeable barrier overlying the disposal zone to
prevent upward migration of either the wastes or
displaced brine waters into fresh water zones.
(3) The well bore must be double cased and
the annular space grouted to a point 200 feet below
the lowest fresh water zone. The outer casing is to
be set into the next lower suitable rock barrier.
(4) The industry must indicate the character
and volume of waters to be injected into the deep
well. Compatibility of the wastes with the forma-
tion fluids must be indicated.
(5) Operational injection pressures to be used
must be indicated in the plan documents. Injection
pressures that cause fracturing of the rock forma-
tions in the injection zone have not been permitted.
(6) Detailed information about the proposed
surface injection equipment must be provided as a
part of the plan documents.
(7) The industry is required as a condition of
the permit to submit daily injection report records
each month to the Illinois Environmental Protec-
tion Agency. These operating reports must include
the character and volume of the waste and show
the injection pressures.
(8) Currently the Illinois Environmental Pro-
tection Agency is reviewing the necessity for
requiring the installation of observation wells to
detect the escape of any fluids from the disposal
zone.
The disposal of industrial wastes in deep wells
is considered relatively new to Illinois. It is realized
that pollution of any underground potable or fresh
waters will undoubtedly represent long-term dam-
age. It is believed and hoped that the procedures
governing the installation and operation of deep
disposal wells are conservative. If there is error in
engineering and administrative judgment, it is
hoped that it will be toward the conservative side
of the scale so that the critical natural resource of
underground water is protected for present and
future use.
The primary desirable characteristic of a sub-
surface disposal reservoir is that it be deep enough
to preclude any possibility of contamination of
potable ground-water supplies. Second, the disposal
reservoir must be deep enough to preclude any
adverse effect on oil or gas production in the area,
and third, it must be a suitable geologic formation.
To be suitable, the subsurface strata must have
sufficient porosity and permeability to accept fluid
wastes at reasonable pressures and contain them
indefinitely. The selected strata must have a cap-
rock that is sufficiently impermeable vertically to
prevent upward migration of injected fluid. Sand-
stone, limestone, and dolomite are the basic
lithologies most commonly considered as potential
disposal reservoirs in Illinois.
The most desirable horizon is a sandstone,
containing salt water (minimum of 10,000 ppm of
dissolved solids), with high porosity and permea-
bility. Also there are several limestone and dolomite
reservoirs in Illinois that contain great volumes of
salt water and can be considered for storage or
disposal areas. The usefulness of these types of
sedimentary formations varies since their porosity
and permeability depend mainly on fractured and
developed solution channels.
From well cores of such formations, essential
laboratory studies are conducted defining the rate
of fluid movement, porosity, and permeability of
the rock and the pressure distribution within the
saltwater aquifer.
Plugging of the injection horizon is the most
serious cause of damage to a fluid injection system
and results from the forming of an impermeable
deposit on the well bore or plugging in the forma-
tion itself. In either case, the plugging may result
from a number of causes:
(1) Injection of fluid containing suspended
solids which are often chemical precipitates.
(2) Accumulation of corrosion products.
(3) Precipitation within the formation as a
result of incompatibility of the injected fluid with
the connate water of the formation.
(4) Injection of insufficiently treated water
resulting in bacteriological plugging.
(5) Swelling of mineral constituents in the
formation.
21
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Fig. 1. Waste disposal well locations.
In most cases the waste product, prior to
injection, will require treatment such as filtration to
remove any suspended solids that might deposit on
the face of the formation. It may require treatment
by additives to stabilize the solution or to prevent
excessive equipment corrosion.
Laboratory tests on core samples ot the
formation will give information on the maximum
particle size of the suspended solids that can be
passed in the filtration process.
The first deep disposal well in Illinois was
placed in operation in November 1965. Since then
three other facilities have been placed in operation.
To date there have been four industrial waste
disposal wells in Illinois, one in Clark County, two
in Douglas County, and one in Putnam County
(Figure 1). Variation in conditions in Illinois is
illustrated by these cases of disposal wells that have
been authorized by the Sanitary Water Board
(Bergstrom, 1968).
The well in Clark County disposes 55 to 65
gallons per minute (gpm) of alkaline solution with
about 65,000 to 100,000 mg/1 dissolved minerals
into creviced Devonian age limestone at a depth of
about 2500 feet. Potable water occurs in the glacial
drift and the upper part of the Pennsylvanian rocks,
but below a depth of a few hundred feet, miner-
alization of water increases rather sharply with
depth. Upward migration of alkaline waste water
would probably be prevented by shales in the
Mississippian and Pennsylvanian rocks. The water
at 2500 feet had total dissolved minerals of more
than 14,000 mg/1.
A somewhat deeper disposal well now in oper-
ation in Douglas Count}" was designed tor injection
of about 35.000 gallons per day (gpd) of hydro-
chloric acid into creviced Potosi Dolomite ot
Cambrian age at a depth of about 5000 teet.
Originally designed for injection of wastes into the
St. Peter Sandstone, the well was drilled deeper
when the permeability of the St. Peter Sandstone
was found to be too low. Substantial shale sections
occur above the disposal zone, and the more per-
meable formations contain water with more than
5000 mg/1 dissolved minerals below the lower
Pennsylvanian (Figure 2). The water at 5000 feet
had total dissolved solids of more than 20,000 mg/1.
A second waste disposal well having about the
same depth and construction features as the first
Douglas County well, Figure 3, has been drilled and
placed in operation in the vicinity of the first
Douglas County well.
The well in Putnam County is for the disposal
of about 100,000 gpd of hydrochloric and chromic
acid from a steel mill. It is in the area where the St.
Peter Sandstone contains usable water, but the
Ironton-Galesville and Mt. Simon Sandstones con-
tain brackish to saline water, injection of wastes is
into a zone of the Mt. Simon Sandstone at a depth
of about 4000 feet. The low permeability of shah-
beds in the Eau Claire Formation and the large
reservoir capacity of the Mt. Simon Sandstone will
prevent the acid waste from moving upward into
the zone of potable water.
Conditions in the northeastern part of Illinois
where potable ground water extends into the upper
part of the Mt. Simon Sandstone are illustrated by
a test hole recently drilled in DuPage County. The
well penetrated the entire Mt. Simon Sandstone
(2200 feet thick) and reached the Precambrian
crystalline basement rocks at a depth of about
4000 feet. Potable water extended to a depth of
about 2300 feet, or 500 feet into the Mt. Simon.
Below this depth the mineralization ot the water
gradually increased to more than 90,000mg/'l at the
base of the Mt. Simon. The 1700 feet of Mt. Simon
that contain nonpotable water consist mainly of
sandstone, with only a few thin shaly zones. It is
questionable whether there are impermeable shah-
zones in the lower Mt. Simon Sandstone with
-------
DEPTH
(feet)
Velstcol Chem. Corp.
NE SW 12-11N-I2W
CLARK COUNTY
Elev. &32f K.B.
Wolcr
Quality
\
f t5OO~
E 70OO~
Cabot Corp.
NW SE 3I-16N-8E
DOUGLAS COUNTY
Elev. 698' K.B.
Jones £ Laughlin Corp.
SW SW 3-32N-2W
PUTNAM COUNTY
Elev. 527' K.B.
\
EXPLANATION
WATER QUALITY
22 Less than 1000 ppm TDM
2 '°00 to 5000 ppm TDM
^ More than 5000 ppm TDM
BOOO~ Water quality in ppm TDM
Am. Potash & Chem Corp. Test
SE SE 9-39N-3E
DU PAGE COUNTY
Elev. lk\ ' K.B.
Fig. 2. Construction details and formations penetrated by disposal wells.
Fig. 3. Douglas County disposal well no. 2.
sufficient thickness to prevent any wastes from
moving upward into the zone of potable water.
This test hole has been abandoned.
For all new disposal wells, after completion of
drilling and evaluation is made of all available
subsurface information (sample descriptions, core
descriptions, logs, porosity, and permeability anal-
yses), injection tests are made for a period of up to
30 days. The injection tests are made with filtered
and treated water to preserve the injection charac-
teristics of the formation. Data from the injection
test will be used to determine the pressure volume
relationship of the formation for future injection.
In the case of the Putnam County well, calculation
of the rate of advance of the interface between the
water and the pickle liquor showed that the radius
of interface would be about 460 feet in 20 years.
CHICAGO AREA DEEP TUNNEL PROJECT
The early sewer systems in the Chicago area
were combined sewers intended to handle both
storm water and raw sewage. This practice has con-
tinued, for the most part, until the present. The
present combined sewer system serves 300 square
miles of heavily populated area.
In time of storm, the capacity of the inter-
ceptor sewer and treatment system is too small to
handle both sewage and storm water. Therefore,
during such periods relief is obtained by discharge
23
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of the mixture of storm water and raw domestic
and industrial sewage to the waterways. The over-
flows from the combined sewer system enter the
Illinois Waterway at some 400 locations (Sheaffer
and Zeizel, 1969).
When the overflows are too large for the
waterway system to accommodate, it is necessary,
on rare occasions, to discharge this mixture of
storm water and sewage to Lake Michigan. Such a
discharge occurred on August 16, 1968. Although
such occasions have been rare (only four times in
the last 25 years), they are detrimental to the water
supply and recreational activities of the area.
Associated with this on many occasions has been
flood damage along the waterway.
An economical solution to the problem has
been offered — it is known as the deep tunnel
project. It combines the (1) City of Chicago
underflow concept with the (2) Metropolitan
Sanitary District deep tunnel project.
(1) Chicago Underflow Concept
It is proposed to construct a large tunnel
under the rivers and canals into which all of the
combined sewers in Chicago would discharge. Thus
spillages from the combined sewers would not
pollute the surface streams but would be directed
to the underground tunnel referred to as the
"underflow mainstream." The plan calls for about
54 miles of mainstream tunnel, plus approximately
40 miles of branch tunnels. The mainstream tunnel
would function as a huge surge tank, taking the
overflow which the treatment plants cannot handle
during periods of rainfall. After the flow had
peaked, the underflow tunnel would be pumped
out and sent to Chicago's sewage treatment plants.
To connect the combined sewer to the mainstream,
tunnel shafts would be dropped down to it at each
outflow sewer's point of discharge.
Chicago has started construction on the first
underflow sewer which runs from the Chicago
River westward paralleling Lawrence Avenue for
about 22,100 feet. The tunnel will have two sec-
tions (Pikarsky and Keifer, 1967). The first section
will be 9300 feet long and 17 feet in diameter, and
the second section will be 12,800 feet long and 12
feet in diameter. A branch tunnel 4000 feet long
and 12 feet in diameter extending along Harding
Avenue and south of Lawrence Avenue is proposed.
Construction is being done by a tunneling
mole that is used to bore through the Niagaran
Limestone stratum at a depth of about 200 feet
below the ground surface.
Ground water is to be protected by lining or
otherwise sealing the tunnel in any sections where
there is leakage. The tunnel will be about 125 feet
24
below the present water level in the Niagaran
Limestone. There is a possibility that there will be
some leakage from the tunnel toward the aquifer
during storm periods that might surcharge the
system. This maximum period of surcharge is
estimated to be less than three days and would
permit a small flow toward the aquifer.
Monitoring wells, equipped with water-level
measuring devices and provisions for collecting
water samples, are to be placed along the tunnel.
This monitoring system will indicate any change in
aquifer pressure or in water quality in the vicinity
of the tunnel that would indicate leakage.
(2) Metropolitan Sanitary District Deep Tunnel
The general concept of the Metropolitan
Sanitary District deep tunnel system, as presently
proposed, combines the City of Chicago underflow
concept with an underground storage concept
(Sheaffer and Zeizel, 1969). The tunnels designed
for flow under pressure, to utilize the large head
available, will conduct the overflow water to a
central mined storage reservoir, some 830 feet
below the land surface. The mined storage reservoir,
made up of large unlined chambers in the Galena-
Platteville dolomite, will consist of two sections, a
settling chamber and the main storage reservoir.
Sewage will first flow into a settling chamber,
which will be large enough to contain runoff from
small and medium storms, and will retain much of
the solid loads of large storm runoffs. The partially
treated sewage will then flow into the main storage
reservoir, from where it will be pumped through
reversible pump turbines to a diked reservoir on
the surface using off-peak power. Storm water
stored in the surface reservoir will further improve
in quality by sedimentation and oxidation, and will
then be fully treated and released gradually to the
waterways. It is estimated that the deep tunnel
system will eliminate 99.5 percent of the pollution
load presently reaching the waterways through
storm overflows from the sewers. Both surface and
lower reservoirs will serve the dual function of
storm water retention and storage for hydroelectric
generation.
The tunnels and mined storage area of the
deep tunnel system will be excavated in the Galena-
Platteville dolomite stratum that underlies the area
at a depth of about 800 feet below the ground
surface.
The ground water in this aquifer is presently
somewhat above the elevation of the settling
chambers and the mined storage area. However,
because of heavy usage, the natural recharge is
inadequate to maintain the ground-water level in
the aquifer, which is falling generally at an average
-------
rate of about 13 feet per year throughout the area,
and soon will be below the storage area elevation.
To adequately protect the water levels in the
aquifer they must be maintained above the tunnels
and mined storage area. This can be done in one of
two ways, (1) by control of ground-water pumping,
or (2) by artificial recharge of the aquifer. It is
believed more conservative at present to recharge
the aquifer.
The feasibility of aquifer recharge has been
based on extensive ground-water investigations,
including an electric analog computer study and
field drilling, seismic surveys, well geophysical
logging, and aquifer pumping tests.
The tunnels and mined storage area will not
be allowed to become pressurized above the
ground-water pressure.
ARTIFICIAL RECHARGE OF THE
CAMBRIAN-ORDOVICIAN AQUIFER
WITH TREATED SEWAGE EFFLUENT
Artificial recharge has been suggested as a
remedial measure for some of the water-supply
problems of the Chicago metropolitan area (Sheaffer
and Zeizel, 1966; McDonald and Sasman, 1967; and
Jones and Heil, 1967). Since the aquifer is deeply
buried it will be necessary to recharge the aquifer
through wells.
The source of water considered for artificial
recharge is sewage effluent (reclaimed water) from
tertiary treatment plants. Gulp (1969) states that
reclaimed water represents a large potential source
of water.
A major problem in well artificial recharge
operations is maintaining injection capacity. Clog-
ging of injection wells has been reported by many
investigators. Although the recharge water may be
classified as of drinking quality, further treatment
may be necessary or methods of well rehabilitation
may be needed to maintain injection capacity. In
addition, the effectiveness of the filtering action
of consolidated sandstones needs to be established.
The State Water Survey has planned a study to
reproduce the processes occurring in injection wells
under controlled conditions in the laboratory. The
object of this research is to study the feasibility of
recharging effluent from a tertiary treatment plant
into the deep sandstone aquifer in northeastern
Illinois, and to investigate methods of further
treatment of tertiary treated sewage effluent so
that it can be used successfully to recharge the
aquifer system.
Upon completion of this initial research it is
proposed that a field research project consisting of
a deep sandstone recharge well with four water
level and sampling wells be constructed in the
Chicago metropolitan area and operated together
with the necessary treatment facilities.
UNDERGROUND GAS STORAGE
Space heating in homes and other buildings
consumes large amounts of gas. Because of the
seasonal fluctuations in the demand for gas for
space heating, the total gas demand generally varies
considerably from summer to winter.
To make better use of the gas pipelines from
the gas fields to the users through the year, the gas
distributors have acquired more heating customers
than the pipelines can supply in the middle of
winter. Then, any deficiency in gas supply is made
up by using gas stored underground during summer
months.
The first practical use of underground gas
storage in Illinois was by Mississippi River Fuel
Corporation at Waterloo in 1950 (Bushbach and
Bond, 1967). In 1952, Natural Gas Pipeline and
Panhandle Eastern Pipeline Companies started their
large projects at Herscher and Waverly, respectively.
Since then, the number of projects and their
capacities have grown continuously. At the present
time there are 24 underground gas storage projects,
and Illinois ranks fifth in total reservoir capacity
among States that have underground gas storage.
Pennsylvania, Michigan, Ohio, and West Virginia
each have \l/2 to 2 times the capacity of Illinois
(Martinson, et al., 1966). Illinois has more potential
aquifer storage capacity than any other State.
To store natural gas underground the follow-
ing conditions are needed: (1) rock layers with
sufficient permeability and porosity to accept and
hold gas, (2) an impermeable caprock overlying the
storage rock to prevent upward migration of gas,
and (3) a geologic trap to keep the gas from moving
in a horizontal direction. This trap may be a dome
or closed anticline caused by gentle upward arching
of the strata, a stratigraphic trap caused by updip
gradation of the reservoir rock from sandstone to
shale, or a trap caused by faulting that seals the
updip side of the reservoir by replacement of an
impermeable bed adjacent to the reservoir.
The porous storage rock in a geologic trap
under the caprock is called a reservoir. This
reservoir may have been filled originally with oil or
gas and thus may be a depleted oil or gas reservoir.
On the other hand, the reservoir may have been
filled originally with water; in this case, it is called
a natural aquifer. The water in an aquifer could be
fresh or salty. In Illinois fresh water aquifers are not
used for gas storage because they are too valuable
as sources of water for human consumption.
25
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When gas is injected into an aquifer, water is
displaced from the pores of the rock around the
injection well. The water and rock around the
storage gas bubble is compressed. In a typical
storage aquifer roughly half of the space for the
injected gas is created by the compression of the
solid rock matrix and half is created by the com-
pression of the water in the pores of the rock. Near
the storage bubble the fluid pressure in the pores of
the rock is the same as it is within the bubble.
The higher the injection pressure, the greater
the rate at which the storage bubble is developed.
If gas is injected at too high a pressure, the caprock
may be fractured. Experience with hydraulic frac-
turing of oil and gas producing wells to increase
production of these wells shows that sand-face
pressures from about 0.7 to 1.0 psi per foot of
depth are required to cause fracturing. In gas
storage aquifers, injection pressures of approxi-
mately 0.55 psi per foot are often used.
Besides pressure per foot of depth, the differ-
ence between the injection pressure and the initial
fluid pressure in the aquifer must also be con-
sidered. In the early stages of the development of
the bubble, this difference is usually held at about
100 psi. If experience shows that this causes no
leakage problems, the pressure difference is then
increased to 200 psi or more, but should not exceed
400 psi except in special cases where extra control
precautions can be taken.
Pipeline companies and other companies sub-
ject to the regulations of the Federal Power Com-
mission must satisfy the requirements of that
Commission with respect to any proposed under-
ground gas storage project. Public utilities operating
in Illinois are subject to the "Public Utilities Act"
(Illinois Revised Statutes, 1965, chapter 111 2/3).
Under Section 55 of this act, the Illinois Commerce
Commission is directed to issue an order author-
izing a new facility (such as an underground gas
storage project) after it has found that the new
facility is necessary.
The Natural Gas Storage Act (Illinois Revised
Statutes, 1965, chapter 104, sections 104-112)
gives storage companies the right to use private
property for gas storage purposes in the manner
provided for by the law of eminent domain. Ac-
cording to the act, before the right of condemna-
tion can be exercised, the corporation must receive
an order from the Illinois Commerce Commission
approving the proposed storage project. The Com-
merce Commission cannot issue such an order
unless it finds that the proposed storage (1) will
be confined to strata lying more than 500 feet
below the surface, (2) will not injure any water
resources, and (3) will involve no condemnation of
26
any interest in any geological stratum containing
oil, gas, or coal in commercial quantities within the
area of the proposed storage.
In addition, gas storage companies that operate
in Illinois are subject to certain rules and regula-
tions of the Illinois Department of Mines and
Minerals and the Illinois Environmental Protection
Agency. Each well that is drilled requires a permit
from the Department of Mines and Minerals. Fur-
thermore, the storage company must furnish evi-
dence to the Illinois Environmental Protection
Agency that the proposed storage project will not
result in the pollution of potable water.
Observation wells are required by the Illinois
Commerce Commission for measuring pressures
within the gas bubble and for measuring changes in
water pressures in all directions from the bubble in
order to detect any possible gas leakage. Records of
these daily observations are submitted monthly to
the Commerce Commission and the Illinois State
Water Survey for study.
WATERFLOOD OPERATIONS
Waterflooding has become an effective and
economical means of stimulating oil production
and is essential to the oil industry of the Illinois
Basin. Secondary recovery by waterflooding ac-
counted for 73.4 percent of the total oil produc-
tion in Illinois during 1968 (Lawry, 1969). In 1968
there were 880 active projects in Illinois with
13,107 water injection wells that injected
518,5 81,000 barrels of water (2581 million gallons).
Most of the water used in waterflooding is
brine that originates from the same formations that
produce oil. Thus, waterflooding presents very few
problems in contaminating the ground-water aqui-
fer as it replaces oil and water that has been with-
drawn.
Good well construction is controlled by a
permit and inspection system administered by the
Illinois Department of Mines and Minerals.
SUMMARY
Great caution must be exercised in the selec-
tion of formations to receive liquids and gases and
liquid wastes for stotage underground. Confining
formations to prevent migration of wastes and
stored material to the ground-water aquifer must be
assured before injection of liquids into permeable
and porous formations is permitted. Adequate
protection of the potable ground-water reservoirs
must be established and maintained at,all times.
This is,done in Illinois through an adequate
permit and inspection system requiring a high
standard of facility design. These designs for any
given project must satisfy the requirements of the
Federal Power Commission, the Illinois Department
-------
of Mines and Minerals, the Illinois Environmental
Protection Agency, or the Illinois Commerce Com-
mission, depending on the circumstances.
REFERENCES
Bergstrom, Robert E. 1968. Feasibility of subsurface dis-
posal of industrial wastes in Illinois. Illinois Geological
Survey Circular 426.
Bushbach, T. C., and D. C. Bond. 1967. Underground stor-
age of natural gas in Illinois, 1967. Illinois Geological
Survey, Illinois Petroleum 86.
Gulp, Russell. 1969. Uses of reclaimed water. Water and
Wastes Engineering, v. 6, no. 7.
Jones, David W., and Richard W. Heil. 1967. Beneficial uses
for northwest area reclaimed water. Metropolitan
Sanitary District of Greater Chicago Report.
Lawry, T. F. 1969. Petroleum industry in Illinois 1968,
Part II, Water flood operations. Illinois Geological
Survey, Illinois Petroleum 92.
Martinson, E. V., et al. 1966. The underground storage of
gas in the United States and Canada, December 31,
1965, 15th Annual Report on Statistics, Committee
on Underground Storage, American Gas Association,
Inc.
McDonald, C. K., and R. T. Sasman. 1967. Artificial
ground-water recharge investigation in northeastern
Illinois. Ground Water, v. 5, no. 2, April.
Pikarsky, Milton, and Cling J. Keifer. 1967. Underflow
sewers for Chicago. Civil Engineering—ASCE, May.
Piper, Arthur M. 1969. Disposal of liquid wastes by injection
underground—neither myth nor millennium. U. S.
Geological Smvey Circular 631.
Sheaffer,1 J. R., and A. J. Zeizel. 1966. The water resource in
northeastern Illinois: Planning its use. Northeastern
Illinois Planning Commission Technical Report No. 4,
June.
Sheaffer, J. R., and A. J. Zeizel. 1969. The impact of the
deep tunnel plan on water resources of northeast
Illinois. Harza Engineering Company and Bauer Engi-
neering, Inc., February.
DISCUSSION
The following questions were answered by H. F.
Smith after delivering his talk entitled "Subsurface
Storage and Disposal in Illinois."
; t
Q. Who is going to pay for the artificial recharge
program—the public, the beneficiaries, or others?
A. The artificial recharge program will be paid for
by the public—in other words, the people who are
going to use the water. In this case the public
would be the beneficiaries.
Q. What is the storage capacity in days of storm
water runoff systems?
A. The storage design was for 2 inches of runoff.
Q. Assuming that fluids break through to \ the
surface, or to aquifers, what do you do for an
encore—apologize, pump into the stream, rapidly
build a treatment plant, change the permit form, or
what?
A. This problem was encountered in the early
beginnings at the Herscher Field not long after it
was put in operation. They had too few injection
wells so it was decided to increase the pressures,
and they probably got a fracturing pressure with
some cement that wasn't as good as it could have
been. They had some migration of gas from the
lower zones up into an upper aquifer. In fact, two
or three farmers had free gas for awhile which they
didn't appreciate. They were paid something for
their inconvenience and I think everyone was
satisfied with the final results of more wells, lower
injection pressures and better well construction.
The same could apply to wastes, as long as they
aren't too toxic. The wastes being disposed of at
present in Illinois are the kind that can be diluted
with water.
Q. This one's a little allied. Michigan has had a
couple of bad gas leaks in private wells. Has Illinois
had any problems and how did they correct the
leaks? How much damage did brine leakage do to
fresh-water aquifers, and was it corrected?
A. Well, I just mentioned a little about the gas
leaks. We have had two shallow aquifers go bad by
brine intrusion. The correction was made by mov-
ing five miles to another well field. I don't think it
has actually been decided who is going to pay the
cost of the five miles of pipeline.
Q. You described four disposal systems in Illinois.
Have you had other applications in Illinois—bow
many, and how many of those have been accepted
to date?
A. The IEPA has requests for two additional
permits for disposal wells. To date, permits have
not been issued for either well.
Q. Regarding the DuPage County Company that
was unwilling to give a definite analysis of their
effluents for underground waste disposal, who
permitted their discharge to surface water in their
present system? Is it now being monitored, and
what standards must they comply with—what
penalties must they face?
A. The Company is now using an oxidation pond,
and there are suspicions that it has leaked. They
have monitored wells as much as 2500 feet from
the pond. Where contamination was noted, the
Company ran a pipeline from the city supply to the
affected wells.
Q. Your printed summary noted plugging problems
related' to both the well bore and the formation.
Bill Tucker noted a similar problem and possible
27
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solution by remedial acidizing. Could you expand
on both the problem and possible solutions?
A. I did not get into this because of time, but we
are having a discussion in Illinois on what is a
maximum size particulate that can be put into
these aquifers. Some of the consultants want to
use a filter that will filter down to about 15
microns. We think perhaps a 5 micron filter will be
necessary. This is being substantiated by field data.
The effluent in the well in Putnam County which is
from a steel mill's waste, is filtered through diato-
maceous earth filters. Their particulate is reduced
to between 10 and 15 microns. I understand that
their injection pressures have continued to rise, and
they believe that within the next six months they
are going to have to rehabilitate the well. I am not
familiar with how they intend to do it, but most
rehabilitation of the deep sandstone in our area is
done by some type of explosive such as primacord,
to clean off the well bore. They are injecting a
pickling acid which has a pH of about IVa so they
have a real strong acid in the well. I am not familiar
with an acid they could use that would help them
more. They may depend on shooting and then
cleaning out for this particular rehabilitation.
Q. How can an injection well be justified under
Section 12 of the Illinois Environmental Protection
Act?
A. The IEPA tells me that under this particular
Section they are not able, at this time, to prohibit
the construction of an injection well if it is proper-
ly constructed and the effluent is acceptable.
Q. What is the rationale of thinking regarding
changing criteria for salinity of injection horizons
from 5,000 at present to 20,000 milligrams per
liter in the future? Will desalting perhaps make
water usable and needed in the future?
A. Yes, we think that desalting can make brackish
water usable economically. Five years ago we
thought that 5,000 ppm of salinity would be a
maximum for conversion but we are now of the
opinion that with certain types of new procedures
and processes, water with 10,000 ppm and perhaps
20,000 ppm of salinity can be demineralized in an
economical fashion. We are raising our sights to
that figure.
Q. What is your opinion of a bill recently intro-
duced in Washington proposing that the federal
government regulate all subsurface injections?
A. I believe I'll pass that for the time being.
Q. Has the storage of gas in sandstone domes in
Illinois had any effect on local deep aquifer systems
regarding quality, pressure, flow, etc. ?
A. None that we know of. We have had observation
wells from about 2,000 feet up to 20 miles from
these domes, and we are unable to see that the gas
pressure has had any great effect on the aquifer
system. In fact, it has had less effect than we really
thought it would have.
Q. Regarding increasing pressure, how much dif-
ferential sheer will you permit between formation
and the casing?
A. I don't have that answer right at hand.
Q. Are periodic, complete chemical analyses, in-
cluding base metals, required for all injection
fluids?
A. Yes. We originally asked for daily samples, but
at the present they are collecting composite sam-
ples over a period of two or three days,
Q. What specific records are required from indus-
trial disposal well operators?
A. The records required are: an analysis of the
fluid injected, the rate, the injection pressure, and
annulus pressure.
Q. Have there been any failures or problems with
any of the storage or disposal systems, beyond the
ones you mentioned in your talk?
A. I do not know of any failures that have oc-
curred other than those mentioned. The systems
have been designed, I think, rather well. The IEPA
has insisted and, of course, the former Department
of Health who formally issued permits, insisted
that the companies use good design and follow a
prescribed method of monitoring, and they have
done real well. One or two gas wells went bad in
the early beginnings. Since they have limited the
pressures on all wells so there is no fracturing of
the formation or any possible disturbance of the
cement bond, the wells have worked real well.
28
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Feasibility of Recharging Treated Sewage Effluent
into a Deep Sandstone Aquifer"
by Richard J. Schichtb
ABSTRACT
Artificial recharge with tertiary treated sewage efflu-
ent has been suggested as one remedial measure for
projected ground-water deficits in the Chicago region, A
deep sandstone aquifer, an important source of ground
water in the region, offers the best opportunity for artificial
recharge. Recharge will be through wells since the aquifer
is deeply buried. Expected problems in maintaining well
injection capacity were studied by recharging treated
effluent through formation cores of the sandstone. Some
success was had in maintaining recharge rates at constant
heads for several days.
INTRODUCTION
The Illinois State Water Survey is engaged in a
comprehensive water-supply study of the metro-
politan Chicago region (northeastern Illinois) (Fig-
ure 1), an area of about 4000 square miles with a
population of about 7.0 million. It is expected that
results of this study will aid in determining the
State's strategy for meeting the demands for water
for the region to the year 2020. The Water Survey
will investigate alternatives and possibilities from
all sources and the economics of each. It is ex-
pected that the study will include use of desalted
water, artificial recharge, reuse, diversion of surface
water, and importation of ground water from
outside of the region.
The importance of ground water in the area is
emphasized by the population dependent upon
ground water as a source of water. Census figures
for the 6-county area are given below.
U. S. Census Count
for 1970
6-County Region 6,978,947
Cook County 5,492,369
Suburban Cook 2,125,412
Chicago 3,366,957
Du Page County 491,882
Kane County 251,005
Lake County 382,638
McHenry County 111,555
Will County 249,498
n
Presented at the National Ground Water Quality
Symposium, Denver, Colorado, August 25-27, 1971.
"Engineer, Illinois State Water Survey, Box 232,
Urbana, Illinois 61801.
Fig. 1. Study area.
It is estimated that about 25 percent of the region's
total population—this includes the population of
most of Du Page, Kane, McHenry, and Will Counties,
over one-half of Lake County and about one-fourth
of Suburban Cook County—are presently dependent
upon ground water as a source of water. Population
and percent of population in the region dependent
upon ground water from work by Schicht and
Moench (1971) for 1980, 2000, and 2020 are
given below.
Population and Percent
of Population
Dependent Upon
Ground Water
Percent
28.9
40.1
51.4
Year
1980
2000
2020
Projected
Population
8,258,390
10,867,805
14,641,950
Population
2,389,160
4,363,620
7,526,290
29
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The report by Schicht and Moench (1971)
stated that the total potable ground water in the
6-county area was greater than the total projected
demand by the year 2020. To meet demand in
some areas, however, importation of ground water
or surface water or development of alternative
sources locally may be necessary. Artificial recharge
is strongly being considered as a remedial measure
for the projected water-supply problems.
It may seem strange that Chicago and her
suburbs do not have an unlimited supply of water
from Lake Michigan. But the Lake Michigan water
supply is limited by the U. S. Supreme Court decree
of 1966 to 3200 cubic feet per second (cfs). The
Supreme Court decree states: "The State of Illinois
may make application for a modification of this
decree so as to permit the diversion of additional
water from Lake Michigan for domestic use when
and if it appears that the reasonable needs of the
Northeastern Illinois Metropolitan Region (com-
prising Cook, Du Page, Kane, Lake, McHenry, and
Will Counties) for water for such use cannot be met
from the water resources available to the region,
including both ground and surface water and the
water authorized by act of Congress and permitted
by this decree to be diverted from Lake Michigan,
and if it further appears that all feasible means
reasonably available to the State of Illinois and its
municipalities, political subdivisions, agencies and
instrumentalities have been employed to improve
the water quality of the Sanitary and Ship Canal
and to conserve and manage the water resources of
the region and the use of water therein in accord-
ance with the best modern scientific knowledge and
engineering practice."
PREVIOUS ARTIFICIAL RECHARGE
INVESTIGATIONS
Artificial recharge into two aquifer systems,
referred to as the shallow aquifers and the deep
sandstone aquifer, have been considered (gener-
alized aquifer descriptions are given in Table 1).
Recharge into the shallow aquifers (shallow sands
and gravels and shallow dolomites) has ,been dis-
cussed in the "Water Resources in Northeastern
Illinois: Planning Its Use," Northeastern Illinois
Metropolitan Area Planning Commission Technical
Report No. 4. The sources of water for artifkial
recharge considered in the report were high flow in
surface streams, water that has been used for cool-
ing, certain industrial waste waters, and treated
domestic sewage. The pit method was considered
mainly because of the experience and success with
the pit recharge operation at Peoria, Illinois (Suter
and Harmeson, I960)., Areas where the pit method
of artificial recharge is potentially favorable were
determined for the planning commission report
based on data from the Illinois State Geological and
Table 1. Generalized Aquifer Descriptions
Geologic Units
Thickness
(feet)
Water Yielding Properties.
Glacial Drift1
Silurian Dolomite1
Maquoketa Shale
Galena-Platteville Dolomite2
Glenwood-St. Peter Sandstone2
Prairie Du Chien, Trempealeau
Dolomite, and Franconia
Formations'
Ironton-Galesville Sandstone2
Eau Claire Shale
Eau Claire and
Mr. Simon Sandstones
0-400+
0-400+
0-250
150-350
75-650
45-790
103-275
235-450
2000±
Yields of wells variable, some well yields greater
than 1000 gpm.
Yields of wells variable, some well yields greater
than 1000 gpm.
Generally not water yielding, acts as barrier be-
tween shallow and deep aquifers.
Water yielding where not capped by shales.
Estimated transmissivity 15 percent that of Cam-
brian-Ordovician aquifer.
Estimated transmissivity 35 percent that of Cam-
brian-Ordovician aquifer.
Estimated transmissivity 50 percent that of Cam-
brian-Ordovician aquifer.
Generally not water yielding, acts as barrier be-
tween Ironton-Galesville and Mt. Simon.
Moderate amounts of water, permeability between
that of Glenwood-St. Peter and Ironton-Galesville,
water quality problem with depth.
1 Glacial drift and shallow dolomite are referred to as the shallow aquifers.
2 Collectively referred to as Cambrian-Ordovician or deep sandstone aquifer.
30
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Water Surveys. These areas were limited to reaches
of major streams in the region. It was estimated
that a potential of 121 million gallons per day
(mgd) could be recharged. The aquifers outlined by
the Planning Commission as favorable for artificial
recharge are in areas for the most part where
ground-water deficits are not expected to occur
until after 2020.
McDonald and Sasman (1967) described a
study made for Park Forest-Chicago Heights that
indicated that artificial recharge to the Silurian
dolomite aquifer, the source of water supply in the
area, is feasible.
They also described five existing artificial
recharge operations utilizing recharge wells. At all
five sites water circulating through closed cooling
systems is recharged. One installation withdraws
water from the deep sandstone aquifer and re-
charges a shallower sandstone at an average rate of
335,000 gallons per day (gpd). The other four
installations withdraw water from and recharge
water to the shallow dolomite at average rates
ranging from 25,000 to 395,000 gpd.
THE DEEP SANDSTONE AQUIFER
The heavily pumped Cambrian-Ordovician or
deep sandstone aquifer, described by Suter et al.
(1959) is presently being considered as offering the
best opportunity for artificial recharge in the
Chicago region.
The deep sandstone aquifer consists in de-
scending order of the Galena-Platteville dolomite,
Glenwood-St. Peter sandstone, and Prairie du Chien
Series of Ordovician age; and the Trempealeau
dolomite, Franconia Formation, and Ironton-Gales-
ville sandstone of Cambrian age. The sequence,
structure, and general characteristics of these rocks
are shown in Figure 2. The deep sandstone aquifer
is separated from the Mt. Simon aquifer by shale
beds of the Eau Claire Formation. The Maquoketa
Formation above the Galena-Platteville dolomite
acts as a barrier between the shallow dolomite and
deeper aquifers, and confines the water in the
deeper aquifers under artesian pressure. Available
data indicate that on a regional basis the entire
sequence of strata, from the top of the Galena-
Platteville to the top of the shale beds of the Eau
Claire Formation, behaves hydraulically as one
aquifer.
The Ironton-Galesville sandstone is the most
productive formation of the deep sandstone aquifer.
The Galena-Platteville dolomite and Prairie du
Chien Series generally are not well creviced; the
Trempealeau dolomite is locally well creviced. The
Glenwood-St. Peter sandstone and Franconia For-
mation yield small to moderate amounts of water.
The deep sandstone aquifer receives water
from overlying glacial deposits mostly in areas of
Kane, McHenry, Kendall, Boone, and DeKalb
Counties where the Galena-Platteville dolomite is
the uppermost bedrock formation below the glacial
deposits. This is west of the border of the Maquo-
keta Formation. Recharge of the glacial deposits
occurs from precipitation that falls locally. Vertical
leakage of water through the Maquoketa Formation
into the deep sandstone aquifer is appreciable
under the influence of large differentials in head
between shallow deposits and the deep sandstone
aquifer.
There are advantages in recharging the deep
sandstone aquifer. The aquifer is uniform in perme-
ability and thickness throughout the region, so
artificial recharge would benefit many users. The
piezometric surface is well defined so that recharge
installations can be located to serve specific areas.
Continued withdrawals from the aquifer in excess
of the practical sustained yield, 46 mgd as estimated
by Suter et al. (1959), will create considerable
storage volume. The practical sustained yield has
been exceeded each year since 1958. It is estimated
that water from the deep sandstone will be with-
drawn at a rate of 622 mgd by 2020 (the estimated
usable water in storage is large, estimated to be 1.6
X 1013 gallons).
Since the deep sandstone aquifer is deeply
buried it will be necessary to recharge the aquifer
through wells. It has been suggested that effluent
that meets drinking water quality standards from
tertiary treatment plants be used as a source of
recharge water. According to Jones and Heil (1967)
one of the potential markets for the effluent is for
ground-water recharge. They report the interest of
Water Commissions in northeastern Illinois in
utilizing effluent from tertiary treatment plants for
artificial ground-water recharge.
Because clogging of injection wells has been
reported by many investigators, including Rebhun
and Schwarz (1968), Bruington and Scares (1965),
and Sniegocki (1963), it was decided to conduct
laboratory studies to acquaint the Water Survey
with some of the problems that may arise from
recharging sewage effluent into the deep sandstone
aquifer. The Water Survey recently completed a
pilot project where sewage effluent from a second-
ary treatment plant was treated and recharged
through formation cores of the deep sandstone
aquifer. The objectives of the project were to study
what water treatment is needed to maintain injec-
tion capacity, to study methods of rehabilitation,
and to investigate methods of further treatment of
secondary or tertiary treated sewage effluent so
that it can be successfully used to recharge the
31
-------
aquifer system and meet water quality standards.
The pilot project was described by Smith,
Schicht, and Humphreys (1970) and is summarized
below.
The new Urbana-Champaign Sanitary District
Plant was selected as the initial laboratory site.
Since the plant provides only secondary treatment
(activated sludge), additional treatment, filtration
and chlorination, was provided. It was later found
necessary to modify the pH of the effluent.
Three types of filters were used: micro-
strainers, diatomaceous earth, and rapid sand. All
three filters were successful in markedly filtering
out suspended solids when operating properly. Two
microstrainers were constructed, one with 26
micron cloth, the other with 10 micron cloth. The
diatomaceous earth filter was a type used for small
swimming pools. A chlorinator was installed ahead
of the filters.
The filtered and chlorinated effluent was
AQUIFER ~—~_^ I _„
"
f -s- -^r-^u^/I
Prairie d u C h i e n
Tre^peaIeau,
and f >~an con i a
Fig. 2. Cross sections of the structure and stratigraphy of the bedrock and piezometnc profiles of the deep sandstone aquifer
in the Chicago region.
-------
injected through a sandstone core used to simulate
a well in the deep sandstone aquifer. The Ironton-
Galesville sandstone, since it is the most productive
formation in the deep sandstone aquifer, was
selected for investigation. The cores, 3 inches in
diameter, were provided by the Northern Illinois
Gas Company, which collected them during a site
investigation for underground gas storage. The
cores were cut into 3 inch lengths and a 1 inch
diameter hole was drilled through their centers.
The cores were placed in a specially designed
permeameter. Deionized water was injected to
eliminate plugging caused by drilling and cutting
and to determine head-discharge relationships. Hor-
izontal permeabilities determined by the Thiem
equation indicated that permeabilities of the sand-
stone cores are comparable to permeabilities of the
sandstone determined from aquifer and pumping
tests.
The permeameter is designed so that effluent
can be injected into the center so that flow is
outward through the core similar to an injection
well. This will be referred to in subsequent dis-
cussions as recharge. Water can also be injected so
that flow is from the outside toward the center of
the core simulating pumping and will be referred to
as backwashing. The rate of recharge was controlled
from a constant head tank so that initially the
recharge rate into an actual deep sandstone well
would be simulated. At first the normal procedure
was to recharge for several hours and then back-
wash with deionized water for a period ot 15 to 60
minutes. The purpose of backwashing was to simu-
late pumping which under field conditions is one
method that can be used for well rehabilitation.
Analyses of the filtered effluent were made to
determine ammonium, nitrate, chemical oxygen de-
mand, biochemical oxygen demand, and bacterial
counts. Ranges of the above are given below.
NH4
NO,
COD
BOD
0.0 to 5.5 19.8 to 57.3 16.8 to 83.3 0 to 8.0
Bacteria plate counts range from 0 to too
numerous to count.
Tests for chlorine residual were made several
times daily. A typical chlorine residual would be
7.8 mg/1 after filtration, 6.6 mg/1 before recharge,
and 4.50 mg/1 after recharge.
Recharge rates through a core with recharge
water filtered by a 10 micron microstrainer and
through a core with recharge water filtered by a
diatomaceous earth filter are shown in Figures 3
and 4. It is apparent from inspection of the graphs
that little success was had in maintaining recharge
A*
s —,
Fig. 3. Discharge rates through core 6 with 10 micron
microstrainer effluent.
13 16
*'AKLH
Fig. 4. Discharge rates through core 10 with diatomaceous
earth effluent.
rates. Some success was had, however, in rehabili-
tating the cores by backwashing.
Clogging was attributed to material precipi-
tating out of the recharge water after chlorination.
Mineral analysis of the recharge water at several
sampling points indicated the precipitate was
calcium phosphate and calcium silicate. The addi-
tion of chlorine (Sodium Hypochlorate) as a disin-
fectant was raising the pH, thus decreasing the
solubility of the effluent. The pH of the effluent
before chlorination was 7.6. The pH after was 8.4.
It was decided to maintain a pH no greater than
7.0 by adding sufficient quantities of diluted
hydrochloric acid immediately after chlorination.
33
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Discharge rates through a core with filtered,
chlorinated, and pH modified effluent is shown in
Figure 5. During this trial it was possible to main-
tain constant discharge rates. Considerable decline
was noted, however, between August 14 and 17
when recharge was discontinued over the weekend.
This decline may be attributed to biological activity
or a precipitate.
Fig. 5. Discharge rates through core 7 with rapid sand filter
effluent.
It is planned to continue this pilot study using
effluent from a treatment plant in the Chicago
region. One objective of further study will be to
maintain constant discharge rates for longer periods
of time.
REFERENCES
Bruington, Arthur E. and Frederick D. Scares. 1965. Oper-
ating a sea water barrier project. Proceedings of the
American Society of Civil Engineers, Journal of the
Irrigation and Drainage Division, v. 91 (IR1), March.
Jones, David W. and Richard W. Heil. 1967. Beneficial uses
for northwest area reclaimed water. Metropolitan
Sanitary District of Greater Chicago Report.
McDonald, C. K. and R. T. Sasman. 1967. Artificial ground-
water recharge investigations in northeastern Illinois.
Illinois State Water Survey Reprint No. 74.
Rebhun, M. and J. Schwarz. 1968. Clogging and contamina-
tion processes in recharge wells. Water Resources
Research, v. 4 (6), December.
Schicht, R. J. and Allen Moench. 1971. Projected ground-
water deficiencies in northeastern Illinois, 1980-2020.
Illinois State Water Survey Circular 101.
Smith, H. F., R. J. Schicht, and H. W. Humphreys. 1970.
Pilot scale investigations of well recharge using cored
samples. Artificial Ground-water Recharge Conference
at University of Reading, England, Paper 11.
Sniegocki, R. T. 1963. Problems in artificial recharge
through wells in the Grand Prairie Region, Arkansas.
U. S. Geological Survey Water-Supply Paper 1615-F.
Surer, Max and Robert H. Harmeson. 1960. Artificial
ground-water recharge at Peoria, Illinois. Illinois State
Water Survey Bulletin 48.
Suter, Max, R. E. Bergstrom, H. F. Smith, G. H. Emrich, W.
C. Walton, and T. E. Larson. 1959. Preliminary report
on ground-water resources of the Chicago Region,
Illinois. Illinois State Water Survey and Geological
Survey Cooperative Ground-Water Report 1.
The Water Resources in Northeastern Illinois: Planning Its
Use. 1966. Northeastern Illinois Planning Commission
Technical Report No. 4. Chicago.
DISCUSSION
The following questions were answered by Richard
J. Schicht after delivering his talk entitled "Feasi-
bility of Recharging Treated Sewage Effluent into a
Deep Sandstone Aquifer."
Q. What are the legal and moral ramifications of
diversion of streamflow by well pumping?
A. In Illinois I'm not familiar with any legal
ramifications of diversion of streamflow by well
pumping. Most of the diversion of streamflow by
induced infiltration, to any appreciable extent,
would be along our major streams and has not been
great enough to reduce the streamflow any appre-
ciable amount. Now the moral ramification I'm
sure is a topic for another session.
Q. Do you have any cost, projections, say a cost
per WOO gallons, to treat and then inject the
treated municipal sewage effluent?
A. The only data I've seen on cost per 1000 gallons
to treat sewage is for secondary treatment. As far
as I understand, tertiary treatment of sewage
effluent is still in the experimental stage, and the
cost would not be realistic. However, we plan to
make cost estimates of treating and injecting at
some stage in the future, but I have no information
on this.
Q. Have you yet attempted to scale your results to
actual field conditions? What is the expected injec-
tion rate per well?
A. We try to maintain a realistic injection rate that
would be comparable to actual field injection. You
can compare about 300 milliliters per minute
through the core with several hundred gallons per
minute in an actual injection well.
Q. How do you propose to backwash the aquifer?
A. We're going to have two strings of pipe in the
well, one for injection and one for pumping. The
pumping is intended to serve as backwashing.
Q. Do you know of anyone m the United States
that is now recharging a confined aquifer?
A. Yes, for example there is injection of cooling
water in the Chicago region into the deep sandstone
aquifer on a small scale.
34
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Q. Have you compared, or do you plan to compare
the direct use of polished effluent versus injecting
it into an aquifer?
A. Yes, we plan to; however, there are probably
social reasons for injecting the sewage effluent into
the aquifer rather than direct use. There's also a
very slow time of travel in this aquifer. We're
talking about movement of less than a foot per day,
and this in itself would give a final polishing to the
effluent.
Q. Shouldn't the quality of water used to recharge
the aquifer system be comparable or compatible
with the existing water quality in the aquifer? Will
the State require tertiary treatment, such as nutri-
ent and heavy metal removal from the water to be
recharged?
A. I think the quality of water will be comparable,
at least within certain limits, to the water in the
aquifer. The effluent will have to meet drinking wa-
ter quality standards.
Q. How do you remove nutrients (phosphates and
nitrates) from your tertiary treatment plant?
A. We have no plans at the present time for re-
moving nitrates or phosphates. Nitrates were one of
the chemical determinations made. The nitrate
content was usually below 45 parts per million.
Analysis for phosphates were not made.
Q. Do you foresee any problems with the forma-
tion of algae due to the temperature of recharged
water?
A. We had problems with algae in the project and
foresee problems during actual field injection.
Q. 7s it feasible to recharge storm water instead of
treated sewage effluents? Are there any studies
being undertaken on the kind of treatment required
for storm water tunoff to be used as recharge?
A. Yes, it would be feasible. In relation to injecting
into the deep sandstone aquifer, we would have to
consider the storm water runoff as sewage effluent
and treat it accordingly. We have made studies
where the storm water runoff has been considered
for use in pit or trench recharge in surficial
formations.
Q. // common law governs withdrawals of water,
how will the recharged stored water be kept for the
"recbarger" instead of being withdrawn by another
party?
A. The "users" would have to be the "rechargers."
In the Chicago region, in the deep sandstone aquifer
with a well-defined piezometric surface, limiting
flow lines could be drawn from the point of injec-
tion, or points of injection, to determine bene-
ficiaries of the recharge water and charge the "user"
based on the benefits from reduced pumping lifts.
It is not proposed that the State of Illinois be the
"recharger." We would operate a demonstration
project and eventually a group of industries and/or
municipalities would undertake the operation of
the recharge installations.
Q. Have you yet experienced the formation of
organic clogging mass at the liquid-solid interface,
as related to aquifer injection now, similar to the
masses that are characteristic in a surface spreading
operation for the field seepage of sewage effluents?
The loss of infiltration capacity begins to show up
in about 50-100 days as a result of these layers.
How long have you run your system continuously?
A. No, we didn't experience the build-up of these
organic clogging mats. I don't believe we actually
ran the experiments long enough. In answer to the
question as to how long we ran the tests, this is
what we hope to do in subsequent studies—be able
to recharge for a longer period of time. The longest
that we ran continuously was five days.
Q. // the chloride ion is not removed from the
sewage water, will a long-term recharge program
ultimately result in brackish formation water?
A. Well, I think you're talking about a period of
time here. What I should point out is that since the
aquifer will be depleted at some time in the future
you will have a storage reservoir underneath the
metropolitan area which can be used to great
advantage. Its use, by not going into some sort of
recharge program is greatly limited. We have only
considered the recharging of sewage effluent in
this particular study. There is also a possibility of
recharging Lake Michigan water directly during
periods when the levels in the lake are critically
high.
35
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Bull Session 1—Ground-Water Waste Disposal Recharge and Reuse
Session Chairman: James C. Warman, Director,
Water Resources Research Institute. Auburn Uni-
versity, Auburn, Alabama 36830.
Leonardo Alvarez, Association of Engineering Geol-
ogists, Palo Alto, California:
I'd like to bring up a year-old question as to
the direction of research that we should undertake
in developing some criteria for disposal of wastes
to wells. We notice that some of the projects we
have in Illinois haven't run into any trouble and
they don't expect to, but there are some ambigui-
ties here and there which bring up the question,
"Why is it so-and-so?" There is no answer. Why is
the pressure head so-and-so, and there is not a
logical answer. I'm bringing up this question—this
topic—what do you think is the logical way to go
about setting up some sort of criteria? I'm sure
industry has done this for a long time, but does
their work apply to what we are doing and, if it
does, should we modify it, and so on and so forth.
James C. Warman, Lead Bull:
I'm sure you don't mean to say there is no
answer—you mean to say we don't yet understand
the answer.
John Rold, Colorado State Geol. Survey, Denver:
I think that most of the answers we are look-
ing for about disposal wells are in the petroleum
engineers' heads and in the research reports that
petroleum engineers have read. When we started
working in Colorado on our rules and regulations,
we found that the petroleum engineers with major
oil companies and research organizations had a
fantastic amount of answers to questions that we,
as geologists, hadn't even begun to comprehend
when we started squirting something underground.
We think of this as a new field. In Illinois, they
talked about having four waste disposal sites and
yet there are 13,000 underground brine disposal
sites in the State. You have difference in viscosity
of fluids and difference in compatibility, but they
have been fighting this problem for 100 years. It
may be that there is research yet to be done on
compatibility of fluids and the like, and the be-
havior of fluids in the ground. This research would
take a lot of monitoring-I feel that we need more
monitoring than we are getting. Many of these
wells, of course, are 7,000 feet deep and we're
talking about a $40,000 or $50,000 hole just for
monitoring. Then you have the possibility that
your monitoring hole may be a leak in the injection
aquifer. For most people concerned about injection
wells, just going through the literature of the petro-
36
leum engineering profession, or getting with a good
petroleum engineer, somebody like Hank Van Fulin,
will give them most of the answers that we have.
Jack Talbot, Brazos Oil & Gas, Houston, Texas:
The preceding comment is very much in order
and, certainly, Dr. Van Fulin and people of his
stature, have contributed a great deal to the basic
and fundamental information that has to do with
this subject. But there are still differences. For
example, some of the injected fluids are corrosive
and difficult to clarify—much more so than oil field
salt waters. Peculiar, subtle metallurgical and ma-
terials-engineering problems are involved, and some
additional and new investigations really need to be
made. One of the things that has surprised me and
my colleagues is that there is so little information
as regards the tolerance of permeable formations to
suspended solids. We know we can pump things like
cottonseed hulls into fractured limestones, and yet
formations exhibiting intergranular porosity are
very sensitive to suspended matter. But the degree
of clarification required is not known. The question
came up yesterday—can you inject 10-micron parti-
cles or is it only 0.3-micron particles? There is a
great deal of work still to be done in this area.
John Fryberger, Consulting Ground-Water Geolo-
gist, Engineering Enterprises, Norman, Oklahoma:
The prime area where we have worked in
Oklahoma is in salt water disposal wells, rather than
industrial wastes. Our experience has shown that
the oil companies are not applying the expertise
that I'm sure they have, at least in salt water dis-
posal. I can cite, as an example, salt water disposal
wells in the Glorieta Formation where they had
perforated 10 feet of casing in formation consisting
of about 100 feet of fine-grain sandstone. Conse-
quently they were using pressures up to about 500
psi ground surface for their salt water disposal in
a formation capable of taking the salt water with
no surface pressure applied. It's a matter of well
design that made them use the pressure. I think we
need a uniform requirement that a disposal well
application should include, in the test drilling
procedure, a determination of the transmissivity of
the injection zone to be used. Once you know the
transmissivity and use the projected injection rates,
you can calculate the formation pressure build-up
which may be far different from the required
injection pressures because of skin losses and plug-
ging of the injection well. If required, injection
pressures might exceed what you would normally
allow for formation pressure, but would still be a
safe formation pressure to use. If you know the
-------
formation transmissivity, you can calculate what
the formation pressure will be with time. This is a
safeguard that I have not seen in my study of
State regulations required now for injection wells.
I'd like to see this adopted.
Speaker not identified:
Would these regulations be within the oil and
gas industry? Or, within some other agency?
John Fryberger:
1 would think that the regulatory agency
charged with the responsibility of industrial waste
wells should have this requirement. The regulatory
agency responsible for salt water disposal wells,
quite often is a separate agency.
Speaker not identified:
Do you think that there should be a dual
responsibility?
John Fryberger:
No, but quite often, that's the way it is with
the State agencies.
John Rold:
On the subject of regulations, Jay Lehr asked
me to talk about Colorado's problems. We're the
most recent State to come up with rules and regula-
tions for disposal wells. I didn't get around to
putting together a paper for the formal program, so
he asked me to discuss this tonight. Colorado had
the unhappy experience of having a deep waste
disposal well which became quite famous, the
Rocky Mountain Arsenal Well, without any rules
and regulations. Then the State passed a law on
water pollution and the Water Pollution Control
Commission went through about a year of hearings
on an application for a radioactive waste disposal
well in northeast Colorado. They still didn't have
any rules and regulations or guidelines. The appli-
cant didn't know what was expected of him and
the Water Pollution Control Commission didn't
know what was expected of them, so they turned
down the application after about a year's hearings.
The Commission then put together a Com-
mittee to come up with a set of rules and regula-
tions. There were about 25 people on the Com-
mittee — geologists, lawyers, sanitary engineers,
petroleum engineers, people from Dowell and
Halburton Service Companies and many of our
State agencies. We had a Geological Committee, a
Reservoir Committee, a Sanitation or Health Com-
mittee and a Legal Committee. Everybody sat down
and first of all wrote to all the States that had any
experience with waste disposal wells and any laws—
they picked all their brains. Then we made a basic
policy decision before we started—that we couldn't
go with hard and fast rules such as Illinois has used
about 5,000 ppm and 10,000 ppm. One of the
reasons is that some of our wastes in Colorado
actually are good enough that they wouldn't hurt
water of 2,000 ppm. We've been in the situation of
having to inject oil field fluids that are 1000 ppm
down a hole rather than let them run into a river
of 1500 ppm.
We came up with a series of factors which
should be considered individually for the situation
at hand. There are 25 or 30 factors that have to be
looked at—for example, the transmissivity of the
reservoir and coefficient of storage. We realize that
it may cost the company wanting a disposal well
probably several hundred thousand dollars to get
all of the data together that would be needed for
an application. So, we have a preliminary applica-
tion situation whereby the applicant can get to-
gether all the data he has, or can put together at a
reasonable cost, and bring the proposition into the
Water Pollution Control Commission and see if it
has any chance of flying at all. So he has some idea
as to whether or not they're going to let him go
ahead with the proposal.
The application has to include a legal descrip-
tion and a map of the area with a two-mile radius
of the proposed well, showing all the surface and
mineral owners. It has to show all test holes and
penetrations, description and depth of all the
formations penetrated by any well or mine on the
map, local topography, industry, fish and wild life,
description of the mineral resources believed to be
present in the area, and the probable effect of the
system on the mineral resources. They have to have
a geologic structure map showing stratigraphic
sections, plus a geologic cross section drawn
through the area and the proposed well, a descrip-
tion of all water resources, surface and subsurface,
within the zone of influence or possible influence
of the system, a classification of those waters, and
a map showing vertical and lateral limits of surface
and subsurface supplies. There must be a descrip-
tion of the chemical, physical, radiological and
biological properties and characteristics of waste to
be disposed of in the system, and treatment pro-
posed for such waste including copies of all plans
and specifications of the system and its appurte-
nances. A statement of all sources relied upon for
information must be set forth in the application. If
the system is to be an injection well, he has to have
potentiometric surface maps of the disposal forma-
tions and those formations immediately above and
below. Copies of all drill stem tests, installations
and data used in making the maps must be includ-
ed. We ran into that on a previous application be-
cause there were a lot of numbers on the map that
37
-------
couldn't be traced to basic data when we were
trying to check them. You must state the location
and nature of present and potential use of fluids
from the disposal or affected formation and the
volume, rate and injection pressure of the fluid to
be injected. Then include the following geological
and physical characteristics of the injection interval
and the overlying and underlying permeable barrier:
thickness, areal extent, lithology, that's grade.
mineralogy, type mineralogy, matrix, amount and
type of cement, clay content and clay mineralogy.
You must include the effective porosity and how
determined, permeability—vertical and horizontal—
and how determined, mechanical logs, and forma-
tion tests. And you must furnish the coefficient of
storage of the aquifer, the amount and extent of
natural fracturing, location, extent and effects of
known or suspected faulting, extent and effects of
natural solution channels, the fluid saturation in
the formation, the formation fluid chemistry with
indicated local and regional variation, temperature
of the formation and how determined, formation
and fluid pressures, fracturing ingredients, osmotic
characteristics of the rocks and fluids comprising
and contiguous to the reservoir and an indication
of the effect of the injected wastes on the contigu-
ous formation in the event of leakage, diffusion and
dispersion characteristics of wastes in the formation
fluid and the effect of gravity segregation, the
compatibility of injected wastes with physical,
chemical and biological characteristics of the reser-
voir. And, of course, you must have the engineering
data on the well which is normal and as detailed
for the geology.
Now, you can see why we give them a chance
for a preliminary go to see if their project applies.
We didn't want any disposal wells unless we knew
they were safe. Since these regulations went into
effect on July 1, 1971, we have had an application
and it was granted for a waste disposal well by
Shell Oil Company, over in the Peonce Basin for
an oil shale experiment. The regulations are feasi-
ble. Shell said it was a real pain in the neck and a
lot of a problem but, by the time they made out
their application, I think they knew more about
the formation and their project than they did when
they started.
Jack Talbot:
Do the oil field salt water disposers have to
comply with these same requirements?
John Rold:
No. In Colorado the disposal of oil field brine
is handled by the Oil and Gas Commission. They
don't have to use these regulations; however, the
Water Pollution Control Commission has essentially
38
said, "Yes, the Oil and Gas Commission has author-
ity over that, but if they goof up once, we'll take it
over." So, it's putting a little bit more surveillance
on the brine disposal.
Unidentified Speaker:
It is fortunate for the prospective injectors
that Colorado is not a large industrial State, be-
cause the information that's requested here, if it
must be supplied, is simply not available.
John Rold:
We are aware of that and aware of the proba-
bility that to get some of this data you'd actually
have to drill one or more test holes down through
the disposal aquifer. We weren't looking to become
a haven for subsurface waste disposal wells. A lot of
people said we'd never get one, but we've already
got one after the regulations came into effect.
Incidentally, the applicant for the unsuccessful
operation that was turned down earlier and had so
much trouble was on the Committee and helped
write these rules.
Zane Spiegel, Ground-Water Hydrologist, Santa Fe,
New Mexico:
I just wanted to ask if this well you speak of
was in an area with existing knowledge from oil
exploration.
John Rold:
There was an amount of existing regional in-
formation in that there were two or three holes
that had been drilled within a few hundred feet, as
well as the hole proposed for injection. So, they
did have the required data.
James C. Warman:
Would anyone else like to comment on these
regulations, their complexity or adequacy, or would
you like to make other comments about regulations
at the moment?
John Fryberger:
I'd like to ask a question of everyone here. Do
you think it would be reasonable to require waste
disposal well applicants to furnish the transmissiv-
ity . . . well, now, let me back up ... in his appli-
cation to furnish all of the background data that
you were talking about—the existing wells in the
area, the geological structure of the horizon that he
would intend to inject into, information that he
could obtain without actually drilling a hole down
there, and have his application be either turned
down on the basis of that information or tentative-
ly accepted on the basis of that information. If it
was tentatively accepted then he would be required
to construct a well—if he wanted to do it this way—
go right ahead and construct his disposal well as he
would intend to use it, and perform tests to deter-
-------
mine the transmissivity of the formation. Based on
these tests, the regulatory agency could then deter-
mine that rate of injection at which the potentio-
metric surface in the injection zone would not be
above the water table or potentiometric surface in
the lowest fresh-water aquifer. And, at that rate of
injection, even if there would be a leak, there'd be
no way for the injected fluid to get into the fresh-
water aquifer. So it would be, in a sense, a fail-safe
type of operation. Do you follow me?
James C. Warman:
Are there any comments on that? That sounds
like a practical approach to me.
Jack Talbot:
Well, it is a practical approach, and this is
what almost all regulatory agencies do, regardless
of whether the discharge is to a surface stream or to
the subsurface, or whatever method is used. Any
scheme that's used to control, or to alleviate a
pollution problem is an interim thing. The per-
mission to use it is an interim thing. I know of
only one State that deviates from the policy-that
requires a permit to drill a well for this purpose—
and that's Alabama. Now you have to have there a
permit to drill an exploratory oil or gas well. You
have to have a permit to drill a salt water disposal
well, but for some reason in Alabama you can go
out with some understanding with the State people
to make a penetration and get the data. Now they
may, or may not, let you use the well, and this
policy is the same as that followed by other States.
This has the same policy as Louisiana. They can
withdraw the permit at any time to discharge into
the subsurface. As regards your limitations on
pressure, there can be some real problems because
of the nature of the fresh ground waters, the pres-
sures under which they exist, and the pressures re-
quired to inject the effluent to the deep subsurface,
these have to be examined on an individual basis
and considered on an individual basis.
H. F. Smith, Illinois State Water Survey, Urbana,
Illinois:
In Illinois, they have to have a permit to drill
an exploratory hole for waste disposal. They need
to furnish the information as best they know simi-
lar to what was outlined here in Colorado—maybe
not so detailed. But then they get a permit to drill
the exploratory hole and that is tested for its
transmissivity and compatibility of the effluents
and so forth. That was the case of the pilot hole
that was drilled in a northern Illinois county. From
all indications, the pilot hole looked like it would
make a well. Following drilling, permeability tests,
and running cores, they did try injection and
couldn't get any injection—the well was abandoned.
But, for all intents and purposes, it looked like a
well until it got to that point. They had a permit to
do it. One of the reasons I think they have a permit
is because you have to specify the fluids you're
going to inject. You can't deviate from that fluid
without going back and having the permit cor-
rected. The regulatory agency turns down a lot of
applications because they just won't permit certain
types of fluid to be injected. The permit to drill the
well itself is a more or less temporary affair, but it's
a permit. If they have demonstrated that it's a good
well, then they do get a permit for operation. But,
until that time, it's just a permit to test and the
permit is required to even start off with one hole.
James C. Warman:
As John Fryberger pointed out, most of the
regulatory agencies are approaching these requests
for permits to construct a disposal well on the
same basis that they consider a request to dispose
of a liquid effluent to a surface stream. The request
for a permit to dispose an effluent to a stream
carries with it a description—some characteriza-
tion-of the fluid, the quantities, and also the kind
of treatment that you are giving this material
before you are turning it loose, or proposing to
turn it loose. These same kinds of things are con-
sidered by the regulatory agencies on this disposal
proposition. You're not just going in to request to
punch an exploratory hole, but you're really going
in with a reasonably complete design package of
the kind of hole you're going to drill, how you're
going to construct it, the kind of tests that you're
going to run on this well that will provide the data
that will give assurance to the regulatory agency
that you have considered these several parameters
that we need be concerned with to satisfy ourselves
that we're not going to violate the fresh-water
aquifers. I don't know of any State that isn't really
looking toward this approach. Some of them are
doing it more or less thoroughly than others and I
suspect most States that are getting into this will
move toward tightening up these requirements for
even this preliminary or feasibility approach, rather
than making it easier as we go along. Now, if we
have explored this facet to your satisfaction-if no
one objects-I'd like to revert back to the original
question, which was, "What kinds of research might
we need to get into to provide some of the answers
that we do not now have?"
Zane Spiegel:
I'd like to make one comment about Mr.
Fryberger's question or suggestion in relation to
the relative heads in the injection zone, or proposed
injection zone, and the heads of overlying fresh-
39
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water aquifers. I think we have two general circum-
stances that we might encounter in this problem.
One is a normal circumstance in which the deep
aquifers, or salt water zones, already have a higher
head than the overlying fresh zone. And this is
actually the normal circumstance. In much of
Oklahoma, Texas and southeastern New Mexico,
oil and gas production has been going on since the
1920's or 1930's and early 1940's. The pressures
in these lower zones—the salt water bearing zones-
have been lowered to the extent that they are much
lower than the overlying zones. Therefore, you
could adhere to his proposal very easily, and inject
significant quantities of water under substantial
new heads—differential heads—without exceeding
these fresh-water heads. But I think in virgin areas
that have not had their potentials lowered by
previous production of either oil or salt water, it
might not be possible to do what you suggest.
James C. Warman:
What we're saying again is that each case is an
individual case and must be considered only on that
basis. Now, let me try again to revert back to the
first question which got such short treatment.
Where are the areas of knowledge in which we are
quite lacking? Where are the research areas? Where
do we need some help?
John Rold:
I'd like to throw one out that's really been
bugging us, and that's the seismic effects of injec-
tion. We have one in our backyard, here, which
has been blamed for several thousand earthquakes
and the people that know more about seismic
activity than I—some of the real experts in this
area—don't believe it. Most people feel it probably
is so, probably because the proponents of the
theory have gotten better coverage than the people
that are against it. You've probably even seen in
such journals as True Magazine about the seismic
effects of the arsenal well. We, however, also have
an injection—which is salt water this time, just an
ordinary salt water injection pressure maintenance
over in an oil field—and they are monitoring a lot
of earthquakes in that oil field. They're all small,
Richter magnitudes of 1,2, and every two or three
years you get one in that area that you can feel.
But, of course, everybody's watching and waiting
for them now. This possible seismic effect of
injection wells is one avenue that really ought to
be studied in considerable detail and very thorough-
ly, or we'll get slapped.
You may have heard that the GSA Meeting in
Milwaukee had an excellent paper on the Seismic
Effect of Dams, i.e., the loading of a dam with
water causing seismic effects. The speaker had five
40
charts and the statistical correlation was beautiful
to show that they built the dam and then the
earthquakes started. When he was about done he
said, "Oh, by the way, that number four, they
never built the dam." So, if you start monitoring
any area with a good enough seismograph, you're
going to pick up a lot of earthquakes. If I were an
oil company, I'd be monitoring any area—especially
an area of population—the day after I got the idea
that I might start injecting fluid into a reservoir.
Frank Kresse, W. A. Wahler & Assoc., Palo Alto,
California:
The U. S. Geological Survey is trying to
trigger earthquakes with the idea of controlling
major earthquakes. Of course, this is a very exotic
thing, but they're really talking about this seriously.
The idea is to construct an injection well along a
fault that has a potential for major earthquakes
and, by injecting fluids, cause small earthquakes
that are undamaging to the point that the strain is
taken off the fault. This is wrought with all kinds
of problems as we can all imagine. That's really
the kind of thing that they're imagining with this
experiment and it should provoke quite a bit of
discussion and thought, anyhow. I'd like to regress
just a little bit. Most of you are familiar with the
Baldwin Reservoir failure in the Los Angeles area
in 1963. The failure of this dam was caused by a
fault offset under the reservoir and under the dam,
and the classic explanation for this was that it was
caused by subsidence from oil withdrawal in adja-
cent oil fields. There was a $30 million lawsuit
which was settled out of court. After the settlement
some of the things that probably occurred came
out and there's been a couple of papers—Doug
Hamilton's and others on this particular thing.
They've given a pretty good case for the idea that
this offset was caused not by the subsidence, but
by injection of water flooding of this same oil
field, and that the offset was really a jacking effect
of the fault itself which caused the failure. They've
got a lot of time and space correlation and so on,
and I feel that this surely was the thing that hap-
pened here.
So this is an example of what can happen,
maybe an unusual one, but one of the other things
that can happen from injection wells. I think there
are at least three or four cases that have enough
documentation where there can be little doubt
that this has happened. When I was involved in the
Baldwin Reservoir lawsuit, I went through the
literature and tried to find all of the cases where
there was at least some documentation and I feel
that there are at least 12 cases, world-wide, where
there is at least some evidence of increasing earth-
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quake activity due to the construction of a
reservoir.
Jack Talbot:
I wonder if an initial bit of research couldn't
be simply to find out reasonably how many types
of injection wells there are in the country, and
where they are. No one seems to know this. How
many wells inject salt water into formations other
than that of origin? What have been the seismic
effects of this? And what have been the effects of
withdrawals, not as regards subsidence, but as
regards earth tremors? I think someone could do a
good study of the literature and the records that
we have in this country and come up with some
useful information. It may allay some of the
apprehensions that go with injection of fluids and
building dams and the like.
James C. Warman:
One of the things in which we can stand a
little research is in the pure economics of what it
really is going to cost to go through the kinds of
testing that the regulatory agencies are going to
have to require—the construction and the testing of
the well itself, and the operation and monitoring of
this well. Then we get into the philosophical bit
about who's going to pay for the monitoring. I'm
not sure where that cost needs to fall. We've had
some research going on in Alabama by Dr. David
M. Grubbs at the University of Alabama. Dr.
Grubbs has been working with well logs from Oil
and Gas Board records and other existing informa-
tion. He sought to determine the most probable
areas, especially in the Coastal Plain part of Ala-
bama, where you might likely be successful in deep
well disposal. He used available data to put to-
gether ideas on how much liquid of what kind you
could inject in these zones in these various
feasible sites that he has identified. And then he's
tied this thing into your need as an industry with a
given effluent. If you will characterize the effluent,
the quantity and type of material you want to get
rid of, he will take your disposal requirements,
consider the geographic, hydrologic, and geologic
setting in which you want to operate, and run all
this through the computer. The computer will—on
the machine—drill a well and attempt to operate
that well to meet your requirements. If it can't
accept your waste in the quantities that you want
to get rid of and the pressures that you're going to
have to handle, the computer will drill another well
and carry cost data with this.
This approach needs refinement, but it's
interesting and promising. If the computer indicates
that you have to drill five wells, you look at the
economics of this and say, "Yes, I can handle that
kind of expense in the construction and operation
costs to dispose of my waste that way." Or you
may say, "No, this is out of the ball park and we
have to find a better way to treat this waste at the
surface and get rid of it with conventional or new-
technology."
Other kinds of work going on at the Universi-
ty of Alabama and elsewhere are concerned with
compatibility of some of the wastes that we know
people are going to try to dispose of through deep
wells—the compatibility of this waste with the
liquid in the reservoir and with the reservoir rock
itself. What other kinds of problems are we going
to have to solve before we can move on with
safety?
Richard J. Schicht, Illinois State Water Survey,
Urbana, Illinois:
Has anyone here had any experience using a
buffer fluid injected before the waste effluent?
Jack Talbot:
Yes, I've been involved in this and it is one of
the less exact sciences. Sometimes I think the
reason this is done is to make everyone feel better.
I'm not really sure what purpose injection of the
buffer fluid, usually fresh water, serves. But it is
convenient, besides making everyone feel better, in
that when you start injecting fluid into a well it's
prudent, normally, to test the surface equipment
and it's nice to do this with fresh water, so you
pump a calculated volume. We use a formula that
Don Warner developed—or his colleagues did—at
the Taft Sanitary Engineering Center, which, so far,
has worked like a charm. But I'm not really sure
that the buffer fluids are necessary. I'd like to say
something about compatibility. A great deal of
research can be done in this area, but I'm not sure
that this is one of the problems of injecting strange
fluids into a formation. We've had the experience
of taking a core—a limestone core—of intergranular
porosity and injecting dilute sulfuric acid into it
and plugging it immediately. Yet, in a real life
situation in the field, it works fine. Now these are
very dilute acid sulfates, and I can't suggest what
the result would be if you injected a more con-
centrated solution. The compatibility is something
that one should be concerned about; but the fact
that core lab work says that you're going to plug
the formation need not stop you from making an
attempt.
James C. Warman:
Any more than when core lab work says it
won't plug the formation is this a guarantee that
injection will be a success. Laboratory results do
offer some mighty good cautions. If you were
considering an effluent that immediately plugged a
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porous limestone core that came from your host
rock, you'd at least better have your eyes open.
Jack Talbot:
Exactly. I'm not denying that caution should
be used in this area. I'm just saying that if a person
or a company has a difficult injection problem and
there appears to be no other way to solve it, he
should not drill the well based solely upon the
laboratory data. Incidentally, the tendency around
the country is becoming more and more to insist
that the applicant examine all reasonable alterna-
tive means—sometimes unreasonable alternatives—
to the solution of his pollution problem. This is
something I, personally, agree with. The subsurface
is limited in its volume, its capacity, and its ability
to accept these fluids, and things that can be
treated on the surface really ought to be treated
there. But, at the same time, there are streams
generated by manufacturing plants that have so far
defied human ingenuity in solving the surface
treatment. And there are those who say there will
never be a solution; they may be overly pessimistic.
The chemists tell me that the chloride effluent is
one very tough problem.
Zane Spiegel:
I have comments on three points and I'll go
backwards. One is that I agree completely with that
last statement about the alternatives, because one
of the alternatives I think that is being proposed
more and more is a recycling type of treatment in
which things are recovered. Many cases have been
mentioned in the last two days where an industry
has been forced to do something like that and
afterwards they've discovered that recovery was
really the most profitable thing to do in the first
place. I guess we haven't looked at these things
carefully enough and the future of recycling is
going to become more and more attractive. The
second point is that I think an obvious explanation
for the difference between laboratory results and
occasional better results from actual tests on forma-
tions is that there may be denser porosity in the
core because the core obviously is a piece that
hasn't been fractured. The third point is to go back
to the kind of basic research that is needed. 1 don't
know whether you'd want to call it research or not.
It's just a collection of the kind of basic data that
we need, the actual formation potentials that exist
and sometimes can be obtained from existing files
of data, particularly in the oil industry, and
development of better methods of collecting these
data. I think the oil industry has been working on
that for the last few years. They were rather lax in
doing that in the earlier years. Much of the data
that we do have is either of no value now because
conditions have changed or it was never of any
value because the data was just no good to start
with. One of the basic things we need is develop-
ment and application of methods of collecting good
data on existing wells.
John Fryberger:
I'd like to expand on what Mr. Spiegel was
just saying. You're referring to the problem of
gathering information on existing wells in the area
where the proposed injection well is to be drilled,
and especially those wells for .which there is no
record. That's a tough one. In some work that I've
done recently, I've tried to gather data on problems
that have been created due to salt water disposal or
water flood operations in contamination of ground
water or surface water supply.
One example that really sticks in my mind is
where they had an injection well about 3,000 feet
deep for water flood and about a quarter of a mile
away there was a hole about 500 feet deep. I don't
even know why the hole was drilled. Some time
after injection was started, salt water poured from
this 500 feet deep hole and it obviously was coming
from this 3,000 feet deep injection well. It flowed
out at the rate of several hundred barrels a day,
flowed into a stream and contaminated the stream
for 15 or 20 miles before it was finally observed.
That illustrates how water might move under-
ground from one zone up to other zones, maybe
through several wells, interconnecting different
zones.
This, to me, illustrates the futility in a way of
having observation wells—monitoring wells—in the
vicinity of an injection well. I really don't think
the information that these safeguards obtain would
be worth the expense, because water can move a
considerable distance away from the injection well
before it comes up through a fracture zone and
never be detected in any monitoring system. So, I
haven't been able to envision in my own mind a
monitoring system that would really do the job at
a reasonable cost.
Jack Talbot:
If you're talking about intergranular porosity
rocks, I just can't agree with that because in an
injection system situation your greatest pressure
difference between the natural head and the injec-
tion formation and the injection pressure exists at
the well bore. For what you're talking about, some-
thing could happen where fractured porosity exists.
But we worry more about the well itself in an inter-
granular porosity situation, which is what we like
to stay with, than we do about what is going to
happen out away from the well bore a half mile or
so, or even less, because at that distance where the
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porosity is intergranular and possesses some reason-
able degree of homogeneity, the difference between
your natural pressure and your injection profile is
going to be minimal. In the case you described, I
would suspect that you've just recited a bad
cement job.
John Fryberger:
This was in SE Kansas where the water was
coming up the 500 feet deep well from a 3,000 feet
deep injection well—I didn't get much more in-
formation other than the specific depth. I got the
information from the Kansas Health Department.
You would propose then putting monitoring
wells, say within ten feet—or some very close prox-
imity to the injection well—is that right?
Jack Talbot:
I probably wouldn't want to inject in an area
like southeastern Kansas in the first place. If you're
talking about somewhere else where the rocks pos-
sess reasonable permeability and porosity and the
geology is fairly well known—yes, I would want the
monitor well near the injection well. Or, perhaps
the injection well itself could be engineered to
serve as a monitor well.
John Fryberger:
Yes, I like that idea, but if you had a separate
monitoring well you would probably want to put
it to the bottom of the lowest fresh water zone.
However, it might be likely that there would be
other permeable zones below the lowest fresh water
that could take the injection fluid that might be
coming up alongside the casing because of a poor
cement job, and the fluid would move laterally and
might find some other avenue up. There are so
many geologic conditions that, in my opinion,
make monitoring not too feasible. In some cases it
would be. As a general thing, I don't think I'd be
for it.
John Rold:
One of the things I think we're going to be
faced with in the near future is the highly toxic
fluids—the real problem fluids. As soon as the
Corps of Engineers puts the clamps down on waste
going into navigable streams or their tributaries we
are going to have a lot of people thinking, "Well,
maybe we ought to put it down a hole." Many of
these fluids are not too bad. There's no real prob-
lem with some of the fluids and it could be fairly
economical, in many instances, to put in an injec-
tion well and get rid of these rather innocuous or
fairly safe fluids that way. Of course, once you say
underground waste disposal well in most circles,
you've got a fantastic emotional problem. Every-
body, including the Sierra Club, is very down on
underground waste disposal wells.
But I think that we should start thinking in
terms of our being a lot better off to put a lot of
these fluids in a salt water formation at 3,000 feet
than running them down the river. There's an awful
lot of that going on. We're just now beginning to
find out how much liquid is being surreptitiously
or otherwise run into a storm sewer or a sanitary
sewer or into a creek. I think that we're going to
be facing a lot of small-time innocuous fluids that
could well be put underground. There again, each
case should be looked at on its own merit.
Jack Woodard, Florida Dept. of Natural Resources,
Tallahassee, Florida:
We've already hit the spots you were just
referring to about getting some of the rather
innocuous materials out of surface streams, espe-
cially in the southeastern section of Florida. In
Florida half of our deep injection wells are dis-
posing of treated sewage effluent. We're afraid we
might want to salvage some of this stuff at a later
date. Also, we don't have much room to build dams
for storage reservoirs in south Florida. We're look-
ing at disposal wells seriously with the idea of
injecting storm water and recovering it at a later
date. There is a little bit in the literature about
this, but I would like to hear, particularly, from
any of the State regulatory agencies who have
criteria on what it would take to inject with the
idea of recovering this particular water. And I
might add that we are putting storm water into a
salt water formation. Everything from 200 feet
down to a 3000 feet injection horizon is a poorer
quality than what we're putting into the 3000
horizon, so I am not too worried about leakage.
Richard J. Schicht:
I don't know if you're familiar with the USGS
project in Norfolk, Virginia. I think they're doing
something similar.
Jack Talbot:
I'd like to ask Mr. Woodard if there are any
plans to do some experimentation for testing to
determine or estimate what the quality of fresh
water will be if it's injected into a saline aquifer
and then recovered. It seems to me that this is
something that needs to be known before there's a
great deal of money and effort spent in this sort
of thing.
Jack Woodard:
Israel didn't have very good luck with their
project and recovery rates. It has proven to be
economically feasible to dispose of storm water and
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particularly sewage effluents into deep storage
wells, but both of these procedures are fairly new.
Right now the entire amount of the monitoring
program in Florida is handled by the private indus-
try which injects the waste. I'm trying to get some
program set up for research in this area, but I was
looking particularly for anybody who might be
doing that. I'm going to pick their brain.
Zane Spiegel:
I know of a couple of cases where water was
injected into sandstone aquifers and then recovered
at a fairly reasonable rate of recovery—something
near 80% as I recall.
Jack Woodard:
Yes. Everything I have found has been in the
sandstone aquifers and we don't have any.
James C. Warman:
All right. Anybody want to shift gears?
John Farbiter:
I would like to ask a question of people who
might know. What fluid is normally used in the
annulus between the long string and the injection
tubing? The ideal fluid would be noncorrosive and
nonelectrolyte. I've heard that diesel oil can be
used.
Richard J. Schicht:
That is what they are using in Illinois. I
haven't heard any complaints about it up to now
so it seems to be working all right.
John Farbiter:
That's the only one that I've heard of and I
was just wondering if there have been others.
Unidentified:
Most commonly, fresh water is used. In my
experience you can add an oxygen scavenger if you
want to be especially particular about it, but nor-
mally this isn't done. Mud is normally avoided
because of the problems of fishing the injection
tube out after some period of operation.
Dick Brown, U. S. Geol. Survey, Lubbock, Texas:
I was waiting to hear someone start on injec-
tion of surface water into aquifers, especially aqui-
fers as a recharge operation. We're involved in the
research in the high plains on artificial recharge. 1
thought that when this time came I would com-
ment on your question as to what size particles
you could get into an aquifer system. We don't
really know this, of course, but we have done a
little work which we thought was interesting.
We have sand columns in the laboratory and
these consist of fine and medium sand. We have
injected through these columns at a range of from
20 to 50 psi at a constant rate. We get a reduction
in permeability of 70% on some of these. We've
taken cores out of these columns and sent them to
Sperry Rand and had scanning electron micrographs
made of the materials taken from the columns after
they are plugged to this extent. What has surprised
us greatly is that in the scanning micrographs,
sediments look as if they're an open boulder field,
and the surface deposit is kind of a layer of sea-
weed over the sand grains and you don't even see it
until you get to 10,000 magnification, and yet this
is enough to cut permeability 70%. We have not
done much with different kinds of clays yet. In
preliminary experiments we ran a mixture of
kaolinite and water through millipor filters; then
we ran pure water and then a mixture of mont-
morillonite and water and we found that we got a
couple of orders of magnitude more water through
in a given amount of time with the kaolinite than
we did with the montmorillonite. In fact we got
more water through with kaolinite than water by
itself. This was 500 mg. per liter of kaolinite, and
then we ran 500 mg. per liter of kaolinite through
first and ran the montmorillonite through later and
got more montmorillonite through than we had
through the filter without any kaolinite on it.
So it makes a big difference as to what you
run through. In much of the literature on artificial
recharge you see the sediment content expressed as
a Jackson Turbidity Unit and here again the JTU
readings for a kaolinite-water mixture are totally
different than for a montmorillonite-water mixture.
There is a magnitude of difference in JTU units for
the same concentrations, so there is a great deal of
work to be done.
James C. Warman:
Having solved "all" the problems of deep well
disposal, I think we may have run down for this
evening. Thank you all for coming in and partici-
pating in the bull session. I think it's been a lot of
fun to sit dov/n together and go at it this way. We
learned a lot by listening to the formal speakers
and having a chance to write questions to them, but
this bull session is another kind of dialogue that is
also quite helpful. We probably need to do more of
this, and less of that, with all deference. More
auspicious groups, for example the Gordon Re-
search Conferences, have found that this type of
dialogue can be highly productive. We hope that
this bull session and the other three underway this
evening will have turned out some thoughts that we
can all pick up from the Proceedings of this
Symposium. Let's get on with the business of
solving problems. Thank you.
44
-------
Pesticide Contamination of a Shallow Bored Well
in the Southeastern Coastal Plains"
by M. J. Lewallenb
ABSTRACT
A comprehensive examination was made of a shallow
farm well which was contaminated with persistent pesticides
when contaminated soil was used as backfill material
around the well casing. The well location was less than 25
feet from a site previously used for flushing an insecticide
sprayer.
Pesticide level in the water has been monitored for
more than 4 years, during which a gradual decline in
concentration has occurred. Soil core samples taken in the
area surrounding the well indicate relatively high surface
contamination but very little downward movement. Sedi-
ment samples from the bottom of the well exhibited
highest concentration of all samples.
INTRODUCTION
Pesticide contamination of water supplies is a
matter of concern to all people associated with
water quality. Because of this interest, many in-
vestigations have been conducted concerning the
occurrence, cause, and solution of problems associ-
ated with pesticide contamination. However, most
research has been directed toward surface water
and municipal supplies.
Large amounts of pesticides are handled and
possibly even stored in close proximity to many
individual water supplies. Quite often these materi-
als are in their most concentrated form when they
are closest to the water supply. Such situations can
occur during filling and flushing of sprayers. Re-
gardless of these seemingly great hazards, few
documented cases exist of pesticide contamination
of individual water supplies. This report documents
the occurrence and describes the conditions which
allowed toxaphene, DDT [1,1, l-trichloro-2, 2-bis-
(p-chlorophenyl) ethane] and its metabolites to
enter a private water supply in the southeastern
Coastal Plains.
Well Construction
The well was constructed in late 1966 and is
typical of many installations in the Southeast,
where rather small water yields are required and
Contribution from the Livestock Engineering and
Farm Structures Branch, Agricultural Engineering Research
Division, Agricultural Research Service, USDA. Presented at
the National Ground Water Quality Symposium, Denver,
Colorado, August 25-27, 1971.
bAgricultural Engineer, U. S. Department of Agri-
culture, Southern Piedmont Conservation Research Center,
Watkinsville, Georgia 30677.
sprayer wash area—^
HOUSE
I '
,fence x_|
0 10 20 30
scale, feet
Fig. 1. Layout of the farm yard.
geologic formations permit the boring of a large
diameter hole. Typically, the well is 30 inches in
diameter and cased with 24 inches inside-diameter
concrete pipes which are 48 inches long. The pipes
are fitted together by a tongue-and-groove type
joint without sealing joints in the casing. Depth of
the well is 40 feet, and the water table averages
approximately 18 feet below the surface.
Contrary to established recommendations (U.
S. Department of Health, Education, and Welfare,
1962), soil was backfilled around the well casing
without using either concrete or clay grout. Typi-
cally, after a few days the inadequately compacted
backfill settled, producing a maze of channels
through the backfill material. The owner then
removed soil from an adjoining area which had
been used to fill and flush the farm sprayer and
placed the contaminated soil around the well casing.
Layout of the farm yard is shown in Figure 1.
Within a few days pesticide contamination was
detectable organoleptically in the water.
EXPERIMENTAL PROCEDURE
Water Samples
Collection of water samples began in January
1967 and has continued periodically since that
time. Typically, 4-liter samples were collected at
the tap adjacent to the pump. Samples were
returned immediately to the laboratory and ex-
tracted in accordance with FWPCA methods (U. S.
Department of the Interior, 1969).
Sediment Samples
Sediment samples have been taken from the
well bottom both to reduce contamination as well
45
-------
as for analysis. The first sample was obtained by
bucket in August '1968. Additional sediment was
pumped from the well in September 1969 and again
in February 1970. Fractionation by gravity separa-
tion was attempted .on the latter sample to obtain
estimates of the pesticide load carried by each
particle size range. However, complete separation
of the silt-clay particles was not obtainable proba-
bly because a dispersant was not added to the
mixture to aid separation. The dispersant was
avoided to prevent the possibility of biasing pesti-
cide determination. '
Soil Samples
Surface soil samples were collected in June
1968 from the immediate area surrounding the
well. In July 1968, soil core samples were taken to
a depth of 6 feet using a 3-inch diameter bucket
auger. Soil backfill around the well casing was also
sampled to a depth of 4 feet. The soil core was
separated into 1-foot increments except the top
foot which was divided into a 0-3-inch surface
sample and a 3-12-inch subsurface sample. Core
samples were taken again in June 1969 in the area
of highest contamination. The sampling device used
was an impact driven sampling tube. These soil
cores were separated into 1-fopt increments except
the top foot which was divided into three 4-inch
samples. Soil samples were air dried in the labora-
tory and extracted using the method of Guenzi
and Beard (1967).
All samples were analyzed for the presence of
toxaphene, DDT, ODD [1, i-dichloro-2, 2-bis-
(p-chlorophenyl) ethane], and DDE [1, 1-dichloro-
2, 2-bis-(p-chlorophenyl) ethylene] using electron
capture equipped gas-liquid chromatographs. Quan-
tification methods used in this study are described
in FDA Pesticide Analytical Manual (U. S. Depart-
ment of Health, Education, and Welfare, 1968).
RESULTS AND DISCUSSION
Water Samples
. Analysis of water samples taken in January
1967 showed 20.1, 1.5 and 0.5 ppb (jug/liter) of
toxaphene, DDT, and DDE, respectively, while
March levels declined to 9'.3, 0.5 and 0.3 ppb,
respectively. Contaminant levels'continued to de-
cline, and in June 1968 levels were 8.4, 0.1 and 0.1
ppb of toxaphene, DDT, and DDE, respectively.
The June 1968 sample was the last one to exhibit
contamination levels greater than the criteria estab-
lished for public water supplies (U. S. Department
of the Interior, 1968). Figures 2, 3, and 4 show
that contaminant levels have oscillated at relatively
'low levels from summer 1967 "until the present.
Presumably an equilibrium exists in the pesticide
content of the sediment and water. This is con-
46
0.3
0.2
Fig. 2. DDT residue in the water as drawn from the tap.
Fig. 3. DDE residue in the water as drawn from the tap.
Fig. 4. Toxaphene residue in the water as drawn from the
tap.
trolled by the absorptive capacity of the sediment
and the solubility of the pesticides in water.
Solubility of DDT is reported to be 1.2 ppb at
25 degrees.|C (Bowman, Acree, and Corbett, 1960).
Sediment Samples
Pesticide levels of sediment samples are shown
in Table 1. Generally, levels in the sediment are
approximately 10" greater than levels in the water.
An exception to this is ODD which appears in
sediment and does not appear in the water. Physical
characteristics of the sediment such as color and
particle size appear identical to that of surface
soil. Hence,r both appearance and results of pesti-
cide analysis indicate that contaminated surface
soil has been transferred to the well bottom.
Incomplete fractionation of the February
1970 sediment samples prevent the drawing of
definite conclusions regarding the relative pesticide
load of each particle size range. Reasons are not
completely clear as to why the combined silt-clay
-------
Table 1. Pesticide Residue in Well Sediment, ppm (/ug/g)
Time of
sample
Aug. 1968
Sept. 1969
Feb. 1970
Complete or
fraction
Complete
Complete
Sand
Silt and clay
Clav
Organic matter
DDT
8.75
3.93
0.13
10.1
0.48
23.8
DDD
11.61
8.65
0.35
7.51
2.30
145.0
DDE
1.25
0.24
0.05
0.66
0.17
13.3
Toxa-
phene
34.6
6.85
0.88
10.2
2.55
235.0
Table 3. Pesticide Residue in Soil Core Samples,
July 1968, ppm
-------
that contamination exists in the soil backfill for the
complete depth of the well.
Table 4. Pesticide Residue in Soil Core Samples,
June 1969, ppm
Distance in feet
and direction Sample
from well depth
Backfill
5-East
10-East
1 5-East
20- East
25-East
0-4 inches
4-8 inches
8-12 inches
1-2 feet
2-3 feet
3-4 feet
4-5 feet
5-6 feet
6-7 feet
7-8 feet
0-4 inches
4-8 inches
8-12 inches
1-2 feet
2-3 feet
3-4 feet
4-5 feet
5-6 feet
6-7 feet
O-4 inches
4-8 inches
8-12 inches
1-2 feet
2-3 feet
3-4 feet
4-5 feet
5-6 feet
6-7 feet
0-4 inches
4-8 inches
8-12 inches
1-2 feet
2-3 feet
3-4 feet
4-5 feet
5-6 feet
6-7 feet
0-4 inches
4-8 inches
8-12 inches
1-2 feet
2-3 feet
3-4 feet
4-5 feet
5-6 feet
6-7 feet
0-4 inches
4-8 inches
8-12 inches
1-2 feet
2-3 feet
3-4 feet
4-5 feet
5-6 feet
6-7 feet
DDT ODD DDE
.019
—
.013
.080
.161
.187
1.516
.733
.654
.573
.049
.091
.024
.014
T
T
-
-
-
.198
.024
.012
-
-
-
-
-
-
1.196
T
T
-
-
T
-
T
-
.188
.020
T
-
-
-
-
-
-
.086
—
-
-
-
-
-
-
—
.012
— —
T*
- .030
.017
.051
.245
.112
.093
.091
.015
.032
T
T
T
T
- -
- -
— —
.055
- .018
.015
- -
- -
- -
- -
- -
— —
.283
T
T
- -
- -
*j*
- -
-T*
— —
.045 .055
T
T
- -
- -
- -
- -
- -
- —
.025 .025
T
T
- -
- -
- -
- -
- -
— —
Toxa-
phene
-
—
-
.208
.543
.543
5.208
3.400
3.000
2.253
-
.417
-
-
-
-
-
-
—
.700
-
-
—
—
—
—
—
—
7.128
—
-
-
—
—
—
—
—
.625
—
-
—
—
—
—
—
—
.217
—
—
—
—
—
—
—
—
* Values less than .010 ppm are shown as trace (T).
48
The occurrence of DDD in sediment samples
and its absence in soil backfill samples, as well as
water samples, raised questions beyond the scope
of this study. However, Miskus, Blair, and Casida
(1965) studied the conversion of DDT to DDD in
lake water and concluded that oxygen content of
the water helped control the conversion rate. Also,
they concluded that DDD appears to be more
stable than DDT under certain conditions.
SUMMARY
This study of a private water supply demon-
strates the susceptibility of improperly constructed
wells to contamination with pesticides. Results of
monitoring water and soil samples for more than 4
years point to the persistence of both DDT and
toxaphene. Probably because of very low solubili-
ties of these insecticides in water, contamination in
the water remained low. Contamination levels in
the sediment were much higher. Soil sampling in
the area around the well indicates the pesticides
have moved only slightly downward, and con-
tamination of the well occurred through the move-
ment to the water table of surface soil containing
adsorbed pesticides.
Results of these studies emphasize the impor-
tance of good design and proper installation for
shallow wells on farms.
The author gratefully acknowledges the assist-
ance of Dr. A. W. White, Soil Scientist, in the
analytical determinations made in this study.
REFERENCES
Bowman, M. C., F. Acree, Jr., and M. K. Corbett. 1960.
Solubility of C14 DDT in water. Jour, of Agricultural
and FoodChem. 8:406.
Guenzi, W. D., and W. E. Beard. 1967. Movement and
persistence of DDT and lindane in soil columns. Soil
Sci. Soc. Amer. Proc. 31(5):644-647.
Miskus, R. P., D. P. Blair, and J. E. Casida. 1965. Conversion
of DDT to DDD by bovine rumen fluid, lake water,
and reduced porphyrins. Jour, of Agricultural and
FoodChem. 13-.481-483.
Trautman, W. L., G. Chesters, and H. B. Pionke. 1968.
Organochlorine insecticide composition of randomly
selected soils from nine states-1967. Pesticides Moni-
toring Jour. 2(2):93-96.
U. S. Department of Health, Education, and Welfare. Food
and Drug Administration. 1968. Methods which detect
multiple residues. In Pesticide Analytical Manual, Vol.
I. Looseleaf.
U. S. Department of Health, Education, and Welfare. Public
Health Service. 1962. Manual of individual water-sup-
ply systems. 121 pp.
U. S. Department of the Interior. Federal Water Pollution
Control Administration. 1968. Water quality criteria.
234 pp.
U. S. Department of the Interior. Federal Water Pollution
Control Administration. 1969. FWPCA method for
chlorinated hydrocarbon pesticides in water and
wastewater. 29 pp.
-------
DISCUSSION
The following questions were answered by M. J.
Lewallen after delivering his talk entitled "Pesticide
Contamination of a Shallow Bored Well in the
Southeastern Coastal Plains."
Q. Was this a routine sampling? Did the owner
suspect contamination and request specific analy-
sis? Did this result from a special survey or study or
were there other reasons for sampling and analyses?
A. Contamination was detected by taste in the
water in this instance. I think, in general, most of
these materials we're speaking of have taste thres-
holds in the low parts per billion range. In this
particular instance, the owner detected a strange
taste and odor in the water. At that point he
realized what had happened and asked us what
steps could be taken.
Q. Has pesticide contamination been measured in
nearby streams?
A. No, they haven't. Pesticide determinations have
been made in a well which is approximately 100
feet from the present well and no pesticides have
been detected in the second well.
Q. What are levels of DDT, DDE, toxaphene, and
so forth, in soils at various depths under natural
conditions in agricultural areas not grossly polluted?
A. This will vary with soils. In general, the down-
ward movement of these materials is very slight.
Probably 6 or 8 inches is about the greatest depth
you'd expect to find these pesticides in these soil
conditions.
Q. Do you know of any adverse effects upon the
owner or the animals in the area?
A. No, I know of no effects. Even though this is a
small farming operation, water has been used for
farm animals continually since installation. I say
that without further comment, because I'm of the
opinion that no analysis was made of any meat
animal which left the farm, so there could have
been unknown contamination.
Q. What method was used to separate the organic
components from the soil?
A. The method used was wet sieving.
Q. Could you discuss that a little more?
A. I might point out that problems encountered in
separating soil sediment for pesticide analysis were
much greater than I anticipated at the beginning. In
fact, I know of no completely fool-proof method of
doing this. Possibly a high-speed centrifuge could
be used for this separation.
The sediment was placed in a container of
water, and sieved with appropriate size sieves to
remove sand and progressively smaller fractions as
far as sieving is possible. Because it is not possible
to sieve down into the clay fraction, the final
separation was attempted by a gravity separation
method. The silt and clay fraction was mixed in a
container of water, stirred thoroughly, and allowed
to set an appropriate time for the settling of the
larger particles, after which clay particles were
siphoned off in the water fraction. This procedure
was repeated six or seven times. Water was then
allowed to evaporate from each mixture. I feel that
the determination for the silt fraction is probably
biased upwards because of. an unknown amount of
clay which was not dispersed adequately and ad-
hered to the silt particles.
Q. Max, what was the soil texture, and can you
speculate why the silt had more pesticides than the
clay?
A. I think the soil here is a sandy loam. I believe
the question as to why the silt contained more
pesticide was answered in the discussion on the
previous question.
Q. The data showing vertical movement of pesti-
cide to the well is not very clear. Would you repeat
how you know pesticide moved to the well through
the ground?
A. I'm sorry I was not clear on that point. In fact,
I did not intend to indicate that pesticide moved
vertically through the soil to the well. The pesticide
contaminated soil was transferred to the water
table and the bottom of the well. This was shown
by the soil profile chart which showed backfill
material of the same color, texture, and particle
size as top soil, and also from pesticide concentra-
tions in top soil as compared to pesticide concen-
trations in the well sediment. Concerning the down-
ward movement of these materials in the area
where the flushing and spraying operation had
taken place, I intended to show that only a slight
downward movement occurred.
Q. Max, did you investigate any ionic change
which might have caused an increase in chloride in
the ground water? Also, have the total dissolved
solids been affected?
A. No, I have not looked at that.
Q. We have about five questions here concerning
the term organoleptically. What is the term organo-
leptically?
A. That would be when you have a strange taste or
odor present.
Q. What is the symbol p,p' that you had before the
DDT in the abstract? That was probably an error, I
imagine.
A. No, p,p' is the para para isomer of DDT. DDT
is composed of the para para, p,p', and the ortho
para, o,p', isomers. Commercial grade DDT is com-
posed mainly of the p,p' isomer with a small
portion of the o,p' isomer.
49
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Gasoline Pollution of a Ground-Water Reservoir
A Case History
by Dennis E. Williams'3 and Dale G. Wilder0
ABSTRACT
A leak in a product gasoline pipeline near the City of
Los Angeles has caused contaminarion of a valuable ground-
water supply. Since 1968, it is estimated that 250,000
gallons of gasoline have seeped into the underground
reservoir, limiting the value of a well field adjacent to the
contaminated area.
Remedial measures include extensive analytical studies
of the two-fluid flow system as well as an all out effort in
the field to try and clean up the gasoline and restore the
aquifer to service. The field methods involve an elaborate
system of "skimming" wells designed to produce a high
gasoline/water ratio and on-site treatment facilities at many
locations throughout the area. To date, 50,000 gallons of
free gasoline have been removed from the aquifer in this
manner.
THE PROBLEM
In September 1968, Forest Lawn Memorial
Park (located in the City of Glendale, California)
reported pumping free gasoline from one of their
large irrigation wells. Upon removal of the produc-
tion pump they proceeded to pump and bail over
1,000 gallons of free gasoline from the well. A
drilling contractor retained by Forest Lawn drilled
some 20 small diameter wells in the area in order
to determine the quantity and extent of the gaso-
line. From the results of these first 20 wells it was
estimated that approximately 160 thousand square
feet of area were influenced with the average depth
of free gasoline ranging from 6 to 18 inches. Using
an average porosity of 30 percent the volume of
free gasoline existing in the reservoir was estimated
to be about 250,000 gallons (see Figure 1).
Shortly after, the Western Oil and Gas Associ-
ation (referred to as VVOGA) was contacted and
proceeded with pressure tests of a buried 8-inch
gasoline pipeline located in the area in hopes ol
^Presented at the National Ground Water Quality
Symposium, Denver, Colorado, August 25-27, 1971.
^Ground-Water Hydrologist, Los Angeles Department
of Water and Power, 111 N. Hope St., Room 1411, Los
Angeles, California 90054. (Now Senior Hydrologist, Louis
Berger, Inc., Tehran, Iran.)
cHydrologic Engineer, Los Angeles Department of
Water and Power, 111 N. Hope St., Room 1411, Los
Angeles, California 90054.
STRONG TASTE
AND ODOR AREA
Fig. 1. Contaminated area and ground-water contours, as of
1968.
determining the source and quantity of any leaks.
Although initial tests were negative, later test re-
sults showed possible evidence of a leak, and flow-
in the pipeline was immediately terminated. WOGA
then initiated an abatement program and proceeded
to hire experts with the hope of attaining rapid
solutions to the contamination. In November of
1969, the Los Angeles Department of Water and
Power turned off its nearby Pollock Well Field to
prevent the contamination from migrating into the
influence cone of the wells.
Extensive drilling and testing continued in the
area under the direction of WOGA to further define
the problem. In April, 1969, it was evident that
some immediate action had to be taken to prevent
contamination of all producing wells in the area. It
was decided to concentrate on an intensive drilling
and pumping program to control the lateral spread
of gasoline.
50
-------
GEOHYDROLOGY
The area involved is located in the southeast
section of the San Fernando Valley where the basin
narrows and contacts the coastal plain of Los
Angeles. In the Forest Lawn area, the valley is
approximately two miles wide and composed main-
ly of alluvial outwash from the San Gabriel
Mountains lying to the north. Sands and gravels
interbedded between lenses of silt and clay consti-
tute an important ground-water reservoir.
The ground-water reservoir is bounded by
Plutonic basement rocks on the east and northeast,
by nonwater-bearing Elysian hill formations to the
west and southwest, and nonwater-bearing sedi-
ments on the south and southeast. In the immediate
Forest Lawn area, the alluvium overlies a basement
complex seen outcropping in the hills to the east.
Immediately overlying the basement rocks, and
underlying the alluvium, is a layer of grey organic
clay.
The random nature of the depositional cycles
has caused the ground-water flow to be predom-
inantly anisotropic with higher hydraulic conduc-
tivities in the direction of alluviation. Interbedded
with the sand and gravel deposits are extensive
lenses of brown clayey-silt which forms localized
barriers (aquitards) to vertical ground-water flow
and have created multiple aquifer systems (see
Figure 2). The depth of the unconsolidated material
ranges from 150 feet to 250 feet deep in the reser-
voir area.
Aquifer tests conducted in some of the recent-
ly drilled wells show hydraulic conductivities
ranging from lows of 500 gpd/ft: and less in the
silty zones, to over 2,000 gpd/ft2 in the clean sands
and gravels. Storativities range from 0.10 to 0.005
suggesting semiconfined aquifers with the confining
layers being somewhat leaky. These aquifer test
results have been supported by geologic samples
and electric logs.
The only significant structural feature in the
area is the east-west trending Raymond Fault. The
A
z
«
- BROWN CLAYEY SILT
GREY ORGANIC CLAY
fault displaces bedrock (Figure 2) but as of yet, no
evidence of displacement (geologic or hydrologic)
in the recent alluvium has been found.
SOLUTION
Since the original indication of the problem,
dating back as far as April 1968, nearly 70 wells
have been drilled in an attempt to adequately
define the problem and expedite the removal of the
FIELD
*
NEWMAN FIELD— *"
>
£-•$. .W-26 FIELD
W-58
*'*
• PUMPING WELL
«fc OBSERVATION WELL
Fig. 2. Geologic cross section — Forest Lawn area.
POLLOCK FIELD
, **> - <-fs ^ RIVER
Fig. 3. Pumping and observation wells.
gasoline (see Figure 3). Principal removal tech-
niques have included skimming operations using
both dual and single completions. In the dual com-
pletion technique the lower aquifer was packed off
and clean water pumped from this zone while
another small pump removed free gasoline and
water from the upper contaminated zone above the
packer. (The packer in the well provided effective
separation for a while; however, the confining
layers were either leaky or only locally continuous
as gasoline was eventually detected in objectionable
amounts from the lower zone.)
Widespread use was made of the single com-
pletion, in which small jet pumps were placed very
near the surface of the water to remove the free
gasoline layer from the top of the water surface.
The skimming wells would then pump into separa-
tor tank assemblies located in the area. These
separators were composed of density stratification
tanks coupled to a larger baffled tank where floata-
tion and skimming, along with aeration in the water
51
-------
progressively separated the gas-water mixture. Free
gasoline was then temporarily stored in a separate
tank prior to disposal by tank trucks.
During the three years of clean up, over
50,000 gallons of gasoline have been removed from
the reservoir. It is believed that most of the free
gasoline has been removed, as most of the wells no
longer show any measurable amounts of gasoline
(see Figure 4).
-\
^ s^ ^^. ^"-. ^v
.g/O^-x \XX
STRONG TASTE /? A', \\ \ '
AND ODOR AREA/X*/!';^ '\^ \
\ y -,
/ /'/; •m^/ / i \ \
f - l(^
f / f, - i i ^
«f ;
/
&%JnJ—^J &.
!". 0 PUMPING WELL
; x « OBSERV*'
1 «„. <£^
• /. *•
.TIOM WELL / ' / / • A> .
POLLOCK FIEL(D J^" /
Fig. 4. Contaminated area and ground-water contours, as of
1971.
The possibility that residual gasoline might
exist which could not be flushed out with water
was recognized long before the clean-up operation
was started and the difference between the original
free gasoline estimate and the actual amount
verified this possibility. It is possible that the lack
of data resulted in erroneous first estimates. It will
be recalled that in the original estimate a porosity
of 30 percent was used in the calculations, while
later pumping test results showed effective porosi-
ties of 10 percent and less.
The difference between the original 250,000
gallon estimate and the 50,000 gallons removed
could also be explained by a reduction in the
relative permeability of the gasoline. In immiscible
(two fluids) flow, the permeability1 of the forma-
1 Permeability as used here is actually the Hydraulic
Conductivity used in ground-water terminology. Due to the
large amount of literature in the petroleum field on two-
fluid flow, the term permeability instead of hydraulic
conductivity is used here for consistency.
tion to one of these fluids is dependent on the
saturation of the other fluid. A relative permea-
bility graph (Figure 5) shows the relationship
between the observed permeability of each fluid
for various saturations to that of the observed
permeability if the sample were 100 percent satu-
rated with that fluid (this permeability ratio is
denoted as Kr). The curves shown in Figure 5 are
not based on any actual laboratory work done in
the Forest Lawn area and cannot be used for
quantitative evaluation of the problem. This rela-
tive permeability concept is not new and has had
widespread use by the oil companies in their
production operations.
Fig. 5. Relative permeability graph.
The three sections shown in Figure 5 (I, II,
III) represent different flow characteristics resulting
from different water saturations. In Region I there
is a high saturation of gasoline; nearly all the fluid
flow is composed of gasoline because it is a con-
tinuous phase while water is discontinuous. This
results in a low relative permeability to water.
Since gasoline is the nonwetting fluid2, the smaller
capillaries will be filled with water (see Figure 6-a).
In Region II both water and gasoline are
continuous, although not necessarily in the same
pores. This continuity allows flow of both water
and gasoline. As the saturation of water increases, a
larger percentage of water will flow (see Figure 6-b).
In Region III (Figure 6-c) there is flow of
water with little or no flow of gasoline. The smaller
capillaries are filled with gasoline only when the
pressure drop overcomes capillary forces. Thus,
2 If adhesive force > cohesive force then 6 < 90
degrees and the liquid is said to be the wetting phase (see
Figure 7).
52
-------
(a)
GASOLINE FLOW
PRESSURE DECREASE-
REGSON 1 - GASOLINE FLOW
WATER FLOW
GASOLINE FLOW
(b)
PRESSURE DECREASE-
RESIONII - MIXED FLOW
(c)
PRESSURE DECRE4SE-
RE6ION HI - WATER FLO*
Fig. 6. Gasoline and water flow.
until the pressure drop (Pgas - Pw) is greater than
Pcap, it is impossible to move the "snapped off"
gasoline bubbles through the throats. As a result,
the gasoline does not fill the "neck" or pore throat,
and becomes extremely difficult to move. The
principle is illustrated in Figure 7 with the follow-
ing conditions pertaining:
For equilibrium:
rgas
- P = P
r w L c
2 a cosi
ap
For movement:
Pgas ~ PW ^ Pcap
nonwetting gasoline
will displace the water.
If Pgas ~ PW < pcap tnen gasoline cannot dis-
place water and therefore
cannot move through the
capillary but will be forced
back until equilibrium is
reached.
Where:
20 cos 6
Pcap = Pressure due to surface energy =
'c
Pw = Pressure on the water side of interface.
Pgas = Pressure on the gasoline side of interface.
NECK OR
PORE THROAT
Fig. 7. Pressures on a capillary interface.
a = Surface energy (a function of the fluids).
B = Angle of contact between fluid and rock
matrix (a function of both rock matrix
and fluid).
rc = Radius of the capillary.
This relative permeability can be both a
hindrance to the removal process as well as an aid
to producing clean water. Since there will always
be some channels or necks which are bigger than
others, it is virtually impossible to flush out all the
remaining gasoline. The water which is used to
flush the sand will tend to flow through unblocked
or continuous water-filled channels rather than
through the gasoline-blocked channels. Conversely,
water which is produced from a contaminated zone
may be essentially clean if the gasoline saturation
has been reduced to a low level.
This idea has been investigated by Los Angeles
Department of Water and Power hydrologists as a
means of cleaning the gasoline contaminated water
after it has been pumped. In the actual experiment,
filter sand was saturated with water and then, a
gasoline-water emulsion forced through the filter.
The ppm of gasoline in the discharge was notice-
ably lower due to this process.
In addition to the lack of data and reduced
relative permeability, another reason for the differ-
ence between the estimated spillage and the total
recovered gasoline is the mixture of gasoline and
water which occurs in the capillary fringe. While
the capillary fringe will be compressed somewhat
by the head of gasoline, there will still be a zone
which contains water held by capillary forces and
gasoline which is free to drain. When the depth of
"free" gasoline is measured in the well, the thick-
ness of gasoline includes both the depth of gasoline,
which is above the fringe, plus the depth of gaso-
53
-------
line which is within the capillary fringe. This could
make the original estimate significantly higher than
it should be (see Figure 8V
, / CAPILLARY FRINGE
,',MBOTH WATER 8 GASOLINE)
(100% WATER SATURATION'
•"7
AQUIFER
BEDROCK
Fig. 8. Gasoline-water table relationships.
Ihe major current problem facing hydrologists
and engineers is how to adequately clean the satu-
rated and unsaturated portions of the aquifer of
residual gasoline. Of several techniques which have
been considered, one of the more promising is to
encourage growth of naturally occurring but nor-
mally dormant bacteria (principally genus pseudo-
monas) which have been detected in water samples
from the area. These bacteria grow on gasoline and
have been noted in wells and separator tanks in the
Forest Lawn area.
Preliminary studies indicate that the bacteria
convert two thirds of the gasoline to carbon diox-
ide and one third to new bacrcna cells. The process
is limited by axaiiabiiitv of oxygen, mineral nutri-
ents and gasoline-water interfaces. It is hoped that
the bacteria can be utilized to clean the aquiter of
the residual gasoline without plugging up the wells
and formation with bacterial slime. Work is present-
ly underway by WOGA and petroleum companies
to solve this slime problem. Unfortunately most of
the work which has been done is not readily availa-
ble, and the applicability of this process to the
Forest Lawn problem cannot be currently analyzed.
SUMMARY AMD PRESENT OPERATIONS
A gasoline spillage of significant magnitude
(250,000 gallons) occurred in the San Fernando
Valley, prior to November 1968, which threatened
an important ground-water supply. The City ot Los
Angeles was forced to terminate production from
its Pollock Well Field to prevent contamination ot
the water supply. An intensive drilling program u .<•••>
undertaken to define the limits and contain the
spread of gasoline.
Efforts to drain off the gasoline have resulted
in a total recover}" of 50,000 gallons of gasoline.
Most of the wells now have only a taste or odor ot
gasoline with only two wells showing any "free"
gasoline. At present, operations arc ar a standstill
with biweekly measurements and monthly samples
taken in order to monitor any changes in the
contamination.
It is hoped that bacteria will eventually break
down the residual gasoline so that the acjuiier may
be restored to service. Studies ol the feasibility ot
this technique are currently being made by WOGA,
the Department of Water and Power, and others.
The results of this contamination are very
costly. The loss of the Pollock Well Field alone is
significant, in addition to the cost of drilling and
operating the 70 wells which are required to con-
tain the spill, and drain off the gasoline.
The costs of remedial measures necessary to
eliminate the contamination in a problem ot this
type far outweigh the relative!}' low costs o!
preventive maintenance.
REFERENCES USED
Hubbcn.M. Kine. 1Q56. Darcv's i-,m and iht ncld equation-
ol the tlov. ol underground iluids. Transactions ot inc
AIM!-', v. 207. p. 222.
Kimkenberg, L. .1. !«42. I'hc- permeability or porous nu\i:;i
to liquids and gases. API Drilling and Production
Practices, p. 201'.
Muskat, M. 1946. The flow of homogeneous fluid-; thnmgh
porous media, j. \V Edwards, Inc.. Ann Aroor,
Michigan, p. 763.
Kabe, C. L. 1967. Unpublished lecture notes. Shell Oil
Company. Technical Training Division.
D-t-
-------
DISCUSSION
The following questions were answered by Dale G.
Wilder after delivering his talk entitled "Gasoline
Pollution of a Ground-Water Reservoir—A Case
History" (coauthored by Dennis E. Williams).
Q. Dale, we have a two part question here-(l)
What is the estimated ground-water volume within
the contaminated area? (2) What is theguesstimated
volume for clearing the aquifer down to the thres-
hold point for gasoline, considering hydrodynamic
dispersion and flow conditions?
A. On the first question, I'm going to have to:
hedge a little bit. The title of the paper refers to the
problem as "A Case History" which is somewhat
misleading because it implies past rather than
current history. However, the outcome is not yet
known and some information, if it were made
public, might influence that outcome. Let me give
you just a little bit of the history of this problem.
The utilities and companies involved, and there
were several, felt that a solution to the problem
was urgent; therefore they initiated cleanup and
monitoring programs, assuming that they would be
able to recover their expenses once the source of
pollution was found. It now appears that there
possibly will be some sort of litigation or out-of-
court bargaining coming up in the future to recover
these expenses. For this reason I can't release the
estimated ground-water volume or the amounts of
money involved.
As far as the volume for clearing the aquifer
down to the threshold point for gasoline, I think
that the current feeling is that it can't be done sole-
ly by pumping of ground water, and this is the
reason for stressing the bacteriological approach.
The lowest gasoline contamination from the separa-
tion facility effluent is about 1 to 2 parts per
million which is well above the threshold value, and
into the objectionable range.
Q. We have three questions here. We'll go one at a
time. Do you feel that the tank and pipeline test
techniques used for routine testing are adequate?
A. This, once again, gets into one of these problem
areas. I think, from what I have read, the test
procedures are adequate. However, the interpreta-
tion of the results is subject to argument. The
procedure used was to pressurize the tank or pipe-
line and then attempt to inject diesel fuel or some
other fluid into it. Any diesel fuel accepted by the
tank or pipeline would either indicate leakage or
some other problem. The petroleum industry felt
that on these particular tests, temperature, com-
pression of entrapped air, and so forth, explained
the volumes of diesel fuel used. However, it was
felt by many people in the water industry that
these tests did show possible leakage.
Q. Were you satisfied with the test of these
facilities after the problem was identified?
A. I think we were basically satisfied with the
second set of tests that were run. The Department
of Water and Power sent representatives out to
observe the tests, and we were satisfied that this
particular test was an adequate test. It was on the
basis of this test that the pipeline was closed in.
Q. What kinds of pumps were used? Were there
any special modifications to prevent explosion?
A. Most of the pumps were air or water operated
jet pumps. There were strong odors built up which
indicated a possible explosive condition, but to my
knowledge, as far as the pumps were concerned,
there were no special precautions taken other than
shielding of all the electrical wiring.
Q. Are the pipeline pumping records so poor that
a 250,000 gallon loss could go unnoticed, and
could the company records be subpoenaed to
determine the actual loss?
A. Let me answer the second part of that first. I
think that the records could be subpoenaed. As
far as "Are the records this poor," when pinned
down, WOGA admitted a 250,000 gallon loss would
probably be picked up in the accounting pro-
cedures. I don't think that they are willing to admit
that there were 250,000 gallons lost. I'm not sure
just exactly how much they can detect. They
haven't released this figure to us.
Q. Was any attempt made to identify what com-
pany produced the gasoline by chemical analyses?
A. Yes. There were several tests run and attempts
made to identify this gasoline. Unfortunately,
contrary to some of the advertisements that the
industry puts out, WOGA tells us that they can't
pin down the brand of the gasoline strictly by
chemical analysis. Originally, they thought that it
was several different types of gasoline mixed
together; then they felt maybe it was just one type
which had been altered in the underground, and so
forth. However, they have not been able to identify
it, at least to the point that they are willing to
admit that they know whose gasoline it is.
Q. Did soluble components pollute the water all
the way to the bottom of the aquifer, or was water
from the bottom still drinkable?
A. It appears that water from the lower portions
of the aquifer was clean and able to be used for
domestic uses. In the Forest Lawn No. 4 well, I
mentioned that they had pumped from the second
55
-------
or the lower part of the aquifer. However, after
pumping for a long period of time, it appeared that
there was some downward leakage of gasoline into
the area. This was somewhat expected based on a
viscous model study made by Dr. Williams which
assumed that the clay formed a leakage layer and
not a solid barrier to fluid flow.
Q. Has the owner of the product pipeline shared
in the cost of removing the gasoline from ground
water in the problem area? If not, why not?
A. Well, I imagine they have, but this information
is not officially available to us. WOGA has repre-
sented the oil industry, and originally it was fairly
common knowledge that the industry as a whole
was sharing in the cost. We understand, or at least
get the feeling from unofficial sources, that recently
one company, specifically Mobil, has been sharing
the majority of the cost. However, I know of no
official notice as to who is paying the cost other
than that monies are coming through WOGA for
the industry as a whole. This inability to obtain
definite information is one of the problems that
you run into with representatives speaking for an
industry as a whole.
Q. Why did you not use activated carbon filters to
remove the taste and odor problems after the pure
gasoline was removed?
A. I'm sorry I didn't mention that when I was
talking about the sand filter. Activated carbon was
tried and found to be much more effective than the
filter sand that was talked about. As a result, this
was suggested as the means for getting rid of the
gasoline in the effluent from the separator tanks.
The only attempt that has been made by the
Department of Power and Water was where they
hooked up a small system to eliminate the gasoline
from the separator tank itself. It looked hopeful
and was working fine; however, it was a very small,
more or less experimental, model. The size of the
facility needed would have to be built by WOGA
and they are not, to my knowledge at least, willing
to do that at this time. They do not feel that it
would be economical.
Q. Has the total cost-to-date of the Forest Lawn
problem been estimated?
A. Part of these costs have been estimated. It is
fairly common knowledge that WOGA has spent in
the range of $700,000 in their drilling and abate-
ment program. However, the costs incurred by
other parties are not available because of possible
litigation.
Q. Did you measure the lead content of the water
from the wells?
A. I'm not really sure of the lead content of the
water itself. The content of the gasoline samples
was taken and it was found to be high-test ethyl
gasoline, but I'm not sure on the water samples. I'm
sure that the lead content of the water is measured
by our Sanitary Department, but I'm not aware of
the results.
Q. Was consideration given to removal or disposal
of gasoline by burning?
A. I really don't know whether or not they con-
sidered burning the gasoline. To my knowledge it
wasn't seriously considered.
Q. Will you inject the gasoline decomposing bac-
teria through wells, and how far do you expect the
bacteria to move?
A. These bacteria occur naturally in the water
itself, so fortunately we won't have to try to inject
the bacteria. The biggest problem I think will be
to try to get the oxygen and nutrients to the
bacteria to let them work on the gasoline, because
the bacteria creates a slime which blocks off the
oxygen and nutrients.
Q. What kind of contamination is occurring in the
aquifer from Forest Lawn?
A. Well, basically, the aquifer around the Forest
Lawn area is not able to be used at all for water
supply at this time. It appears that the pollution
at least is under control—that is, we have not
picked up any new gasoline contamination. As far
as contamination by Forest Lawn itself, they use
various chemicals, and it was suggested that the
reason the gasoline could not be identified was
that there were chemicals from the cemetery mixed
in it. However, 1 think that this was discounted
later and, to my knowledge, gasoline is the
principal pollutant in the area.
56
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Petroleum Contamination of Ground Water
in Maryland
by John R. Matis"
ABSTRACT
Petroleum contamination of ground water is a wide-
spread problem that plagues many areas. Historical data
collected in Maryland indicates that most counties in the
State record cases of this contamination problem annually.
Cases in the "hard-rock areas" west of the Fall Zone have
the highest frequency of occurrence, in contrast to the
Coastal Plain geologic province to the east. In both areas,
the problems have been very localized. It is difficult to
handle petroleum contamination cases, and the legal impli-
cations are very complex. A disturbing factor is that many
petroleum fuels do not deteriorate in the ground-water
system. Further, the identification of specific petroleum
products in ground water is generally not possible with
present techniques. An investigation of a particular com-
plaint can often be split into a preliminary phase and a
detailed site investigation phase. Once a source of con-
tamination is located, it must be stopped or removed. Since
it is virtually impossible to remove the contaminant from
the ground water, legal and regulatory problems continue on
for months or years after an original complaint.
INTRODUCTION
Petroleum contamination of ground water can
be expensive and time consuming for water re-
sources regulatory agencies. Typical of after-the-
fact ground-water quality problems, it is reported
or defined only after the damage has occurred.
County health departments were surveyed in 1971
for information on the subject, and the historical
data collected indicate that many homeowners have
been troubled with petroleum fuel in their wells in
the past.
The geology, geography, and climate of Mary-
land is similar to other Eastern Seaboard States and
as a result, the hydrogeologic principles of petrole-
um contamination defined here, should apply to
other areas. Primarily because of this reason, the
American Petroleum Institute was contacted in
1971 for assistance and advice. The API expressed
an interest in the problem and indicated that con-
siderable research has been done in Europe on the
topic. This report presents guidelines which are
applicable for use by water resources management
agencies.
Presented at the National Ground Water Quality
Symposium, Denver, Colorado, August 25-27, 1971.
^Groundwater Management Division, Maryland De-
partment of Water Resources, State Office Building,
Annapolis, Maryland 21401.
THE GEOLOGIC SETTING
The geologic framework of the State of Mary-
land defines the severity and location of this con-
tamination problem. In general, the Fall Zone,
where the Coastal Plain sediments contact hard
rocks of the Piedmont, acts as a dividing line in
dealing with complaints. The "hard-rock" areas
west of the Fall Zone have the highest frequency
of cases of petroleum contamination in contrast to
the Coastal Plain geologic province to the east (see
Figure 1).
From examining the data it would appear that
the area around Annapolis has a very high incidence
of contamination. However, the presence of State
offices in Annapolis and the active county health
department staff is reflected in the greater number
of cases recorded for Anne Arunde! County (12).
Also, these statistics include only those cases re-
ported to State agencies and county health depart-
ments. Oftentimes, other cases are not reported and
individual problems encountered from leaking gaso-
line station tanks are handled by the company in-
volved. As communication improves between coun-
ty and State agencies, and the public, more cases
will be reported.
In both the hard-rock and Coastal Plain areas,
the problems are very localized, and individual cases
are often confined to several acres. The difference
in frequency of occurrence results from hydrologic
factors. Silts and clays in the Coastal Plain sedi-
ments, for example, tend to attenuate hydrocarbon
fuels that leak from buried tanks and from spills.
Also, the high density surface drainage may inter-
cept a great deal of the material before it becomes
widely dispersed. And finally, the dilution factor of
the ground water in the Coastal Plain is very great.
In the hard-rock areas, ground-water flow is
confined to fractures in the rock, and hence flow is
channelized to some extent. This means that the
contaminant remains more concentrated in the
ground water. Secondly, clays and silts are gener-
ally absent and attenuation is less important as a
controlling process. In general then, the petroleum
accumulates in the fractures, which are defined by
local geologic structure, and flows in well-defined
patterns. In limestone regions, or in other similar
hydrologic situations, the potential travel distance
of the contaminant would be much greater than in
57
-------
Fig. 1. Cases of petroleum contamination recorded in Maryland counties, 1969-1970.
the Coastal Plain. Likewise, the transit time of the
fuel from the source to the well could be much
shorter.
COMMENTS AND OBSERVATIONS
Usually a local sanitarian will receive the initial
complaint and in Maryland, he then refers it to the
Maryland Department of Water Resources. This
procedure has developed for several reasons. For
example, anyone who has ever tried to define
source areas for the petroleum products or who has
confronted the aggrieved individual with the con-
taminated well can testify to the extreme diffi-
culty of handling these cases. The distraught home-
owner generally does not understand the nature of
the problem or the nature of ground-water flow.
As a result, tempers flare and few cases are ever
settled to the satisfaction of the aggrieved party(s).
Also, the State entered the problem here partly
because of the complex legal nature of contamina-
tion cases. Expert opinions are needed for adequate
settlement, and of course, the State wanted to keep
track of any deleterious water quality changes
within its domain. Our present position is to define
the situation, eliminate the source of contamina-
tion, and where appropriate, try to locate an alter-
nate source of water (such as another well site) for
the aggrieved party.
The most disturbing and pervasive factor in
58
these cases, is that gasoline and kerosene (low
boiling point hydrocarbons) essentially do not
deteriorate in the ground-water system (James
Grutsch, American Oil, personal communication).
Once they reach the water table they remain there
indefinitely or until they move out of the area with
the ground water. These low boiling point hydro-
carbons actually float on the water table at higher
concentrations. As a result, any open hole, and
particularly a pumping well, tends to act as a
hydraulic sink and draws in the material.
Identification of specific petroleum products
at the very low concentrations typically found in
contaminated wells is generally not possible with
present techniques. The infrared spectrophotometer
procedure requires at least 1-10 ml. of concentrate.
Oftentimes it is virtually impossible to remove this
required amount. The gas chromatograph may
alternately be used, but it can only identify "low
boiling point" or "high boiling point hydrocar-
bons"—not specific unknowns like gasoline and
kerosene. The human threshold for detection of
gasoline, however, is O.OO5 mg/1 and approximately
0.01 mg/1 for fuel oil (McKee and Wolf, 1963. p.
230). As a result, you can smell and taste hydro-
carbon fuels in water even though you can't detect
it on the gas chromatograph.
Of course, high concentrations of particular
products resulting from gross contamination can be
-------
worked with in the lab and specific products identi-
fied. This may be complicated, however, by aging
of the fuels in the ground and by mixing of differ-
ent products. It appears that microbial breakdown
and oxidation of some petroleum fuels does occur
over long periods of time.
Frequently a contaminated well is sampled in
the field, and the contaminant volatilizes before
tests are run in the lab. It is very disturbing to the
homeowner to receive a negative report in the mail
from the State Department of Health or Water
Resources when he knows that the water is con-
taminated. This happens so often in Maryland that
we now accept personal taste-odor confirmation by
the field investigator at the time of sampling. Any
samples actually collected are taken in glass bottles
with rubber stoppers. Later in the lab, a microliter
syringe can be inserted to draw off vapors for gas
chromatograph analysis.
Once a positive result is obtained, the investi-
gation then centers on the location of possible
sources. Some cases are.very obvious and require
little knowledge of hydrology, while others seem
unbelievably complex. The ability of the investi-
gator to understand (or at least have a feeling for)
ground-water hydrology becomes very important.
He must first determine where the contaminant
originates and secondly, eliminate the source(s).
The following outline lists procedures that might
be followed when investigating petroleum con-
tamination cases.
PROCEDURES FOR INVESTIGATION
1. Is the complaint still valid; can the investi-
gator taste: or smell contamination in the com-
plainant's ground water; when did the problem
start?
a. Does the complainant have any source of
petroleum stored on his property?
b. Has any repair been made recently on his
water system (possibility of contamination from
plumber's tools, etc.)?
c. Has the complainant or anyone else re-
cently spilled petroleum products on his property?
During rainy weather, a rise in the water table
may concentrate more petroleum product on the
water surface. Or,, heavy rains may actually flush
more material downward to the ground water.
Hence the relationship of rain to the contamination
problem should be asked of all parties. Another
major point is that ground water flows downgradi-
ent under water table conditions. If a series of wells
on a slight grade are all contaminated, it is most
likely that the source of contamination is upgrade.
2. Go to all nearby houses, garages, etc.
a. First check for the presence of petroleum
in the" ground water, then essentially repeat as
above.
b. Look for sources of petroleum products.
c. Ask about and look for evidence of
accidental spillage.
3. Check with all nearby (within several hun-
dred yards) gasoline stations and repeat as above.
a. Identify the full names, addresses and
phone numbers of owners and operators, and
gasoline distributors for the station(s).
b. Ask for information on storage tanks or
pump leaks.
(1) Identify the owner(s) or responsible
parties for all buried tanks of any kind.
(2) How long have the tanks been in and
have they been checked for leaks recently?
(3) Have the tanks been filled recently?
Does this correlate to the appearance of con-
taminant in the complainant's well?
c. Look at the complete physical layout of
the station.
(1) Identify all drains and ditches, both
inside and outside the station.
(2) Look for places where oil or gasoline
is drained into the ground.
d. Try to determine if any operating, pro-
cedure contributes to the problem such as:
. , (1) Throwing waste oil or gasoline out on
the ground. ,
(2) Flushing petroleum products down
drains or septic tanks.
^(3) Unnecessary, spillage of gasoline when
filling trucks, filling cars,;etc.
(4) Poor storage facilities for old drums
full of oil or other petroleum fuels.
(5) Possible spillage by other parties at
the station site.
e. Notify the owner or operator that all the
tanks and lines should be checked for leaks. (We
have observed that leaks from broken buried lines
and not from the tanks themselves have caused
many gasoline station problems in Maryland. The
operator of the station will generally detect such a
leak as a loss of gasoline, or as water in his tanks.)
Any operating procedures or physical characteristic
of the station layout that might contribute to the
problem should.be changed, or.altered accordingly.
In Maryland we issue a formal pollution complaint
to force compliance with these recommendations.
The two main aspects of the service station
investigation .concern the physical setup of the
gasoline station and the operating procedures used
at the station. The tanks and lines generally consti-
tute the parent oil company's property, and are
their responsibility. Other physical aspects of the
station (i. e. drains, pits, storage areas, the building)
59
-------
may or may not be owned by the parent company.
Any operational procedures are the responsibility
of the owner and/or operator of the station.
After all the above have been considered and
no leak or source is found, the investigator can
probably conclude that the gasoline station is not
the source of contamination.
4. Recheck the local area, from bouse to
house, to church, to repair shop, etc., and try to
find the source.
5. Request a more detailed investigation if
this final check fails to uncover a source. Other
considerations, such as the complexity of the
situation might also -warrant a more detailed study.
This procedure may seem unduly complex,
but it is important to try to define the limits of
contamination. Some people, particularly those
who are old or very poor, may be reluctant to
admit that they have a contaminated well. They
fear that the health department may condemn
their water supply or that they will become in-
volved in a costly lawsuit. The field investigator
must allay their fears and obtain accurate informa-
tion.
DETAILED SITE INVESTIGATION
In spite of these time consuming and detailed
procedures, a hydrogeologist will frequently have
to make a field inspection to determine the
source(s) of contamination. In many cases, several
possible sources may be identified, although in
other cases, the initial overview may disclose no
possible sources. In one such instance in Maryland,
vandals apparently dumped oil down a home-
owner's well. To pinpoint an exact source, how-
ever, sometimes a test drilling program is required.
For this purpose in Maryland, we use an auger
drilling rig.
The Groundwater Management Division re-
ceives the preliminary data and conclusions (or
questions) of the field investigator. Upon recom-
mendation from him, we then proceed with a more
detailed site inspection. Initially we attempt to
visually determine the ground-water flow at the
site. We may be able to quickly locate sources of
contamination or define the contaminated area. If
auger drilling is required, we drill shallow holes
through the weathered rock or sediments to the
water table. During the drilling, soil samples are
collected for analysis and inspected by the hydro-
geologist in the field. A plastic pipe or casing can be
inserted in the hole to let the water collect. The
water in the pipe is sampled and analyzed. Eventu-
ally, "positive" data points may define a source,
such as a buried tank. It is significant to note that
the expense involved in test drilling often precludes
this technique as a routine investigatory tool.
60
Once it is located, the source of contamina-
tion must be stopped or removed. Maryland law
allows us to issue a formal pollution order which
requires compliance with our findings and recom-
mendations. If the situation warrants it, we may
also advise the aggrieved party to seek legal counsel.
OTHER CONTROLLING FACTORS
Since the configuration of the water table
generally reflects topography, most gasoline con-
tamination cases can be easily defined. In one
interesting case, however, it appeared that a hard
clay layer in the weathered rock zone prevented
downward movement of gasoline from a nearby
service station. Spilled gasoline probably moved on
the top of this hard red clay, and then was inter-
cepted by nearby wells penetrating it.
Disturbed ground may be more permeable
than surrounding native rock and sediments. Be-
cause of its higher permeability, it may intercept
and channelize contaminants. Northeast of Balti-
more a buried continental pipeline developed a
severe leak, but all of the gasoline remained in the
disturbed fill around the line. Where the pipeline
crossed a small stream, however, the fuel seeped
out and, of course, became obvious as it floated
downstream.
In another case a buried tile foundation drain
intercepted and concentrated sizable amounts of
gasoline and Number 2 diesel fuel. Both of these
fuels were present in the ground at the building
site, probably the result of a gasoline station leak
at some time in the past. The flammable materials
and fumes in the sump pit created an explosion
hazard near the building, and only after modifying
the drain system considerably was the problem
brought under control. The first concern in this
instance was to remove or lessen the hazard. Con-
currently, efforts were made to separate the gaso-
line from the discharging water. However, the dis-
charge of gasoline to the city storm drains was
avoided because it also created a potential explo-
sion hazard. Pockets of fuel might have collected in
low spots in the storm drain system, and invited a
disaster.
The integrity of the wells in a petroleum con-
taminated area also seems to have an influence on
the occurrence of well contamination. A longer
length of casing and a good grouting job may
save some homeowners from problems of this
sort. Of course, in the Coastal Plain a new well
could be drilled to another aquifer in an uncon-
taminated zone.
Over a period of time pumping may remove
some of the contaminant. Although we have ad-
vised the use of this technique for cases of minor
contamination, it has not definitely proven success-
-------
ful. An activated carbon water filtering system can
also remove some types of petroleum fuels at very
low concentrations. However, in Maryland we are
not aware of any water conditioning equipment
that can remove significant amounts of petroleum
contaminant.
Occasionally the petroleum contaminant may
move out of the area or be sufficiently dispersed so
that it can no longer be tasted in the water. The
aggrieved parties have then been advised to use the
water. In general, water that is only slightly con-
taminated by petroleum fuels is not toxic to hu-
mans. By the time the concentration reaches a
toxic level, no one would be able to stand the
smell or be able to drink it (McKee and Wolf, 1963,
p. 230).
CONCLUSIONS
To summarize, the impact of the problem on
ground-water management in Maryland is greater
than had been expected. Each case requires at least
one day in the field by an investigator and fre-
quently by a hydrogeologist as well. Figure 1 indi-
cates that in 1969-1970 over 60 cases were recorded
by county health departments and Maryland De-
partment of Water Resources personnel. County
health department sanitarians also contacted many
of the people involved and collected water samples.
As a result, the problem has consumed a large
number of man hours.
Fortunately to date, all of the cases we have
handled have been settled out of court. It is con-
ceivable, however, that the investigating hydro-
geologist may eventually have to appear in court as
an expert witness to discuss the findings of his
investigation. Hence the obligation to present a
factual definition of the hydrologic environment is
critical. With regard to clean-up activities, it may
be (and often is) impossible to remove the con-
taminant from the ground water. This presents
interesting, if not continuing legal implications.
It seems that the more cases you handle
successfully, the more you receive for action. The
problem has not been given priority in the past,
but will be handled more directly in the future.
SELECTED REFERENCES
Anon. 1970. Modern practices in infrared spectroscopy,
laboratory manual. Beckman Instruments, Inc., Fuller-
ton, California.
Levy, Eugene. 1969. Application of gas chromatography to
the analysis of petroleum fractions. General Course
manual, gas chromatography. Hewlett-Packard Com-
pany, Baltimore, Maryland.
McKee, Jack E. and Harold W. Wolf. 1963. Water quality
criteria. California Department of Water Resources
Publication No. 3—A.
Yokes, Harold E. and Jonathan Edwards. 1968. Geography
and geology of Maryland. Maryland Geological Survey
Bulletin 19.
DISCUSSION
The following questions were answered by John R.
Matis after delivering his talk entitled "Petroleum
Contamination of Ground Water in Maryland."
Q. In a group of service stations, what method do
you recommend to determine which of the gasoline
stations' tanks is leaking? In other words, how do
you differentiate one from a group of many?
A. You have asked a significant question. There is
no good way at the present time, as the previous
speaker indicated, to determine the gasoline from,
say a Mobil Oil station or a Texaco station or an
ESSO station, in a typical contaminated water
supply. Additives are used to identify a particular
company's product. If the petroleum contaminant
occurs in the parts per million range, and the
additives occur at a parts per million of that, the
problem is obvious. These additives would therefore
occur at extremely low concentrations in con-
taminated ground water. Hence it would be impos-
sible to detect them and differentiate gasolines. As
far as locating a source, we would suggest a test
hole drilling program, and leak testing of all tanks
and lines.
Q. Undoubtedly, the use of various storage tanks
is increasing with the increase in auto population.
Is there any feasible preventative maintenance
program that will enable the owner or regulatory
agency to predict the probable onset of tank
leakage as the tanks age?
A. The idea of a preventative maintenance program
deserves more attention by the petroleum compa-
nies. There are many factors which determine why
a tank leaks. Some tanks, for example, have been
dug up and the tar coating on the outside is just as
fresh as when it was buried. However, it is becom-
ing increasingly obvious—because of contamination
and the dollar suits involved—that some oil distrib-
utors are going to Fiberglas lined tanks which do
not deteriorate, and I think that this is one of the
answers we have at the present time. Perhaps some
changes in the construction of buried lines would
also be desirable.
Q. Are your efforts, in part, responsible for the
popularity of Fiberglas TOL tanks and piping?
A. I'm sure our efforts are not the total effort
involved. Research people in the petroleum indus-
try have said that they are limited because they
operate under an economic condition. In other
words, changes in tank construction and develop-
ment of new identification techniques cost money.
These changes cannot be made without sufficient
documentation. So our documentation probably
helps their programs along.
61
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Bull Session 2—Chemical Contamination of Ground Water
Session Chairman: Allen Agnew, Director, State of
Washington Water Research Center, Pullman,
Washington 99163,
Allen Agnew, Lead Bull:
Gentlemen, \ve are going to operate with two
mikes tonight. As you know, this is all being
recorded, so when you speak please bear this in
mind and identity yourself each time. I am Allen
Apnew. not Bill Cawlev who, as vou know, is
u *
unable to be here. Yesterday afternoon, Bob Crowe
filled in for him, and I am filling in for him tonight.
You remember our session consisted of four
speakers, one who was unable to speak, but had
presented an abstract earlier, for our use. In dis-
cussing ground-water pollution, we talked about
pesticides, gasoline, and petroleum in general. We
had some unanswered questions. I would like to
open this discussion by asking Dale Wilder if he has
anything furthei to say in elaboration of what he
said or in response to questions he received this
afternoon.
Dale Wilder, Hydrologic Engineer, Los Angeles
Department of Water and Power:
The only comment I had was that there had
been some discussion after both my paper and
John Matis's paper, in relation to whether or not
the petroleum products can be identified by labora-
tory analysis. It appears from comments of at least
two or three individuals that there are some labora-
tories that feel they can analyze petroleum prod-
ucts as to brand, type and even possibly area that
they were produced from, depending upon the
type of sample they are given and whether or not
they have a good standard to compare with.
Of course, there was also one other comment
that was brought up when John and I were talking—
that is, we might be able to use radioactive tracers
to inject in underground storage' tank leaks and
pipeline leaks to monitor them. The problem that
we could see with this particular technique is the
public hazard and the public pressure involved.
lust as a way of comment, we had a reservoir
in Owens Valley, California, that appeared to be
leaking. We had some drains about a quarter of a
mile away from the reservoir, and had been picking
up quite a bit of water flow in them. The Hydrol-
ogy Section wanted to account for that water and
they didn't want to double-budget it, so they were
wondering how we could actually find out if this
water was coming from the reservoir or if it was
coming through a basalt area to the east of the
reservoir. We considered running radioactive ma-
terial and finally gave up on this particular ap-
62
proach, for the very same reason that I think the
same approach would be difficult in the business of
trying to find oil leakage.
There is no build-up of population at all in this
area. The valley is owned jointly by several people,
but the Los Angeles Department of Water and
Power owns most of the valley floor; they bought
it up several years ago to obtain the water rights.
So, it is not a problem of who owns the land or a
problem of people living there, but it is a problem
because the water eventually gets down to Los
Angeles and, even though the half-life may be
sufficient that the radioactivity would already be
dissipated before it reached Lo^ Angeles, it was
feared that the public in Los Angeles would be very
sensitive to this. We've tried dyes very unsuccess-
fully.
Jay Lehr, Executive Director, NWWA, Columbus,
Ohio:
I've been wondering—listening to John's paper
on gasoline contamination and yours on petroleum
contamination—how serious a problem this is on a
nation-wide scale. Are we just talking about more
of an odd-ball situation? I mean, John talks about
something like 60 cases in the State of Maryland.
Well, that's not too many, and they affected
seemingly very few people. Your situation in Los
Angeles, of course, was an enormous problem but,
again, it was accident in the nature of an off-shore
oil spill. How really significant is this kind of
problem in ground-water development, nation-
wide? Also I can bring in Lewallen's paper on
pesticides—he almost went so far as to say that in
an area where the pesticide contamination was.
prevalent, it wasn't that serious. I'm wondering if
things are as bad as we thought they were.
Dale Wilder:
In relation to a couple of questions that you
asked, I originally felt that the gasoline spillage
was probably a rather isolated case. But, in talking
to a few individuals, I find that maybe it is a little
more ' common than I realized. As far as actual
numbers are concerned, I can't give you a real
handle on this, but I have a request already from
one individual (who wasn't able to make the
conference) for a copy of the paper; he feels that
he has the same problem in Ohio. There are similar
problems mentioned throughout the nation, al-
though they are isolated cases, as far as I know.
In relation to whether or not this may be
similar to the pesticide problem where it is not all
that critical, I think that this would depend quite a
bit on the individual case. In our case, it was a very
-------
great problem. We did have to close down a well
field, and Forest Lawn has had to buy water,
rather than use their own water. However, there is
some possibility, that after the initial flushing took
place, we may have suffered no damage other than
objectionable taste. That is, the water may be con-
taminated, but it may be possible to clear it up
through the use of some sort of filtration system,
such as activated charcoal. Now, one of the reasons
I feel that WOGA (Western Oil and Gas Association)
did not go to the activated charcoal in their
separator facilities was basically economics. The
estimates were that it would cost somewhere
around $90 per acre-foot to clean this up by
activated charcoal. We can buy that water for
around $50-$60 per acre-foot so they felt it was
better just to replace that water.
Now, this isn't getting into the safety aspect.
What do you do with the gasoline and water
mixture, when from a purely economic standpoint
it may be less costly1 just to ignore that particular
water resource and try to use some other resource?
If we were in a really bad pinch, like we may pos-
sibly get in because of the recent California earth-
quake, and because'of other losses of water supply,
then maybe this would be a much greater problem
than it is today. Right now, from a practical view-
point, we probably can work around it but, from a
standpoint of contamination, I think it is a serious
problem.
Dick Rhindress, Pennsylvania Department of En-
vironmental Resources, Harrisburg, Pennsylvania:
I, too, have a very similar problem to yours in
California, but mine is in Pennsylvania. I think I
should respond to a number of the questions that
have been asked already. On identification of the
product as free gasoline, we have a little different
situation because we can just bail it up in a bailer.
We have been able to go right to the brand of the
gasoline and, in fact, mix several grades and brands
of gasoline together to get the precise combination
we have on the ground. It was slightly trial and
error, but on the gas chromatograph, infrared and
ultraviolet tests, we can come up with precisely
the same curve. It's fantastic how close it is, in fact.
In cases where we've had just extractable
amounts—something we've extracted from basically
a water sample, we have been able to say that this
is gasoline or this is fuel oil. On a couple of oc-
casions we have come close to being able to say a
product name, but we haven't been able to really
pin down a specific product. We've been able to
exclude some. For instance, we've been able to say
in one case where there are two pipelines involved,
that it's not the Esso pipeline, but. it is one of the
products that the Sun pipeline happens to be carry-
ing. But, exactly which of the Sun products we
can't determine.
On the subject of radioactive tracers, we have
tossed this around, as well. We've come up with the
same problem of public acceptance of radioactive
tracers. . .we just forgot the idea right there. We
have, however, been thinking about using some of
the isotope tracers which are not radioactive. We
gave this thought to the oil companies—we have
two pipelines and three companies involved in our
worst problem—but they refused absolutely saying,
"we don't want any contaminant in our products."
Now this, of course, would be in the parts per
billion range, but it was a contaminant to their oil
and they didn't want it because they had a market-
ing product and they said this would foul up their
marketing if it ever got to the public. Because all
actions taken by our department are public, if we
recommended and asked for this, it would be
public knowledge that these oil companies had
accepted it.
Jay asked about the significance nation-wide.
In Maryland there is a report of about 60 spills. I
can put my hands on about nine major ones in
Pennsylvania, one of which is to the point where
we've had explosions in two houses. Thank God, no
one has been hurt, yet. We've had people evacuated
from their homes because of liquid, free gasoline
that's flowing into their cellars. In the latest
instance, the people were out for 4 or 5 months.
This was because the gasoline pool was in a karst
aquifer in the Great Valley of Pennsylvania, and it
just rises up every time we have a rainfall.
I received a call tonight that we have a hurri-
cane headed up the coast and I'm supposed to be
home in case something happens. That's where we
live.
On the charcoal filtration thought, we also
propose charcoal filtration in practically every case
around the State, where we have the individual gas
stations polluting an individual well. Usually, it
doesn't work. The economics are just too much at
the gas station-distributor level. The oil company
does not stand behind the continued use of the
charcoal filter—they just won't go into a long-term
economic responsibility like that. The people who
own the home either drill a new well, try a charcoal
filter for a while, give up and then just start boiling
water to get the hydrocarbons to volatilize, or bring
in water from a neighbor's for drinking and use the
oily water for showers and so forth. Charcoal filters
just don't work because of economics.
Mike Bell, North Carolina State Board of Health,
Greenville, North Carolina:
I wanted to reply to Jay's question about the
seriousness of gasoline contamination. I don't know
63
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about it on a national scale. I had one experience
where a town of about 400 people had a well con-
taminated; we traced it down finally to a build-up
of cleaning fluid and waste oil that a garage had
been dumping into a ditch. It traveled some 225
feet through the ground and contaminated the
town well. This town, if they had not had some
back-up wells, would have been completely out of
water. As a result, they did have to rely on an old
well which had not been abandoned, but had al-
most been discarded because of mineral quality.
So, we would have a serious problem without these
back-up wells and we were quite concerned about
the loss of this well. This is one instance which was
very serious; I wouldn't be surprised to see this
happening in other places because of the lack of
concern that's been shown so far.
Allen Agnew:
That is a good comment, and it is one that I
had hoped would come up tonight. That is, the
deliberate or careless washing down of the filling-
station areas into the city drainage system and,
where there's infiltration of recharge from this
system, we are getting pollutants into our ground
water. Where it isn't going into the ground water,
it's going into the surface water and so it is a prob-
lem of the integrated hydrology of the two types
of water.
Ben Wilmoth, EPA, Wheeling, West Virginia:
During the past year, I've talked with State
sanitarians who have investigated several fuel oil
contamination problems in consolidated rocks. In
some cases, the contamination traveled as much as
300 feet in sandstone or shale. Then there was one
of these fuel oil problems with a school, in which
the fuel oil tank probably contaminated the well
at the school—probably caused by overfilling. I
don't know how much was spilled, but apparently
it doesn't take too much to result in a problem.
Another case—a thousand gallons of gasoline leaked
from a corroded buried tank and contaminated a
school well 300 feet away; this was also in con-
solidated rock, sandstone. In the Ohio River Valley,
petroleum chemicals from a tank-car siding con-
taminated a municipal water supply; they were
able to alleviate this by aeration, but not com-
pletely eliminate it.
Verne Farmer, Humble Oil and Refining Co.,
Houston, Texas:
Several people here have observed specific
instances and suggestions of instances of pollution
by oil and gas. For about the last year I've been
trying to make an inventory of many various types
of hydrocarbon spills into the soils and ground-
water systems, but my efforts haven't really come
64
to much. Does anyone here know of any such in-
ventory, or systematic collection of incidents that
has been assembled—perhaps by the U.S.G.S. or by
a State agency?
The API several months ago conducted a
survey among its members, most of whom are the
middle size and bigger oil companies, asking for
case histories and examples of spills that these
people had experienced. They got some 110 replies
but most of these were the bigger examples, the
more spectacular types of things, and in my opinion
don't even begin to represent a true, systematic
inventory. My interest in this, really, is that
Humble—along with most other major companies-
is pretty sincerely interested in trying to do every-
thing we can to both avoid and clean up these spills
whenever they do occur. Really what we need.
more than anything else, are precedents—history
and experience with a large variety of these things.
We have a lot of dope on the big ones like Forest
Lawn, Mechanicsburg, and Savannah, but those
aren't typical. Ones where 8 or 10 or 15 individual
wells may get polluted, these are more common.
And most of these things don't get a lot of publici-
ty. It's a local thing and that's about the end of it.
If anyone has any thoughts on approaches or
methodology for handling these things, I would
certainly welcome them.
Allen Agnew:
Mr. Farmer, in your survey, did you tackle the
organization of State sanitary engineers, the State
Board of Health people? These are the people who
not only have the information within the States,
but they get together annually to compare notes
and complain about inadequacies in the system, so
I would think they would be a good source.
Verne Farmer:
It could be. This really wasn't a systematic
survey in the sense that I wrote to representatives
in all 50 States asking them for cases of this kind.
This was a hit-or-miss sort of thing. I talked to
about everybody that I could find, various agencies
and various States. My experience with this sam-
pling—which was certainly not complete—was that
not very many people knew anything about it at all.
And I just assumed that probably this was typical
of what you would get if you ran a 50-State survey,
which I confess I did not.
Allen Agnew:
We have at least one State agency man here,
maybe more—and I don't want to throw the heat
on him, but I think that maybe he is in a spot to
respond to this.
Dick Rhindress:
I am in a spot to respond to this. Companies
-------
which we are working with on petroleum product
clean-up do not even notify us of other spills and
ground-water contamination problems which they
are having elsewhere in the State.
To the second part of the point that was made
about contacting a State sanitary engineer, I'm not
sure it would do much good. The regional people
in our Health Department don't get the word to the
central office. They try to handle it on their own.
They don't even call in the geologists that they
know they have, to help them with it. This is a
problem we have and I'm sure other States have it.
The regional sanitarian who is a county man, or
maybe even at the township level, just does not use
the facilities of his professional help at the top
level, and the word will never get to the State
sanitary engineer. There's a break in the chain-of-
command in Pennsylvania—I know it exists in other
States as well. It's a nice idea to ask him, but I
know the man personally—I work with him—and
he just doesn't know about them except what I tell
him on the way home from work—not through an
official channel.
Allen Agnew:
It seems to me that we need to have a focus
for our communication, and what is the focus?
Well, to me it seems that it would have to be the
man at the State level—the man who is responsible,
and if there is a breakdown in the internal com-
munication, we've got to rectify that. Because until
that is done, we're going to be sitting on two sides
of the fence griping at each other about each one
not doing his job. So I think we need to do a lot of
homework inside the State among the different
layers of government to clean up this inadequate
communication pipeline.
Elmer Jones, Agricultural Engineer, Department of
Agriculture, Beltsville, Maryland:
This problem is bigger than one can see, be-
cause people can have petroleum products in their
well and be totally unaware of it if the proper
conditions exist—if the production zone is at the
lower part of the well and the pump is deeply
submerged and there is no water entering the upper
casing so that turbulent entrainment of the lighter
petroleum fractions might carry them down to the
pump.
In pumping sediment from the bottom of a
well for pesticide analysis, we obtained a large
amount of a jelly-like substance; the owners of the
well admitted to having a fuel oil leak several years
prior to this, about 120 feet from the well. But
they very strongly maintained that at no time had
they been aware of any petroleum product in the
well by taste, odor, or by seeing it as a thin film on
standing water.
I was concerned whether plastic pipe would be
a potential health hazard, in that something would
be extractable from the petroleum—gasoline or
more solvent materials. Normal drinking water
would not extract such material from the pipe,
but such an accidental exposure should be con-
sidered in considering selection criteria for plastic
pipe. Floyd Taylor, of the Public Health Service,
serves on one of the building research advisory
boards on plastic pipe. Floyd has, in the Public
Health Service interstate-carrier drinking-water pro-
gram, investigated several gasoline spills; the feeling
of the PHS is that basically such a spill does not
represent a health hazard because normally it is
possible to construct wells cased and grouted
through the surface layer so that you can still
obtain water of good quality. This is not to defend
the spill, but to indicate that where this is a serious
problem, well construction should be taken into
account.
Now, you can turn it around and look at it the
other way—say, a fuel truck driver accidentally mis-
takes the upper casing terminal of the well for the
entrance to the fuel oil tank, and dumps fuel oil
down the well. Here is a case where you would
really like to have a fully constructed well that is
not cased to below the water table, because when
the well is cased to below the water table and you
force fuel oil down it, the oil will come out the
bottom of the casing, rise to the water surface, and
go on to some other point where it can continue to
be a problem. So, the point of injection can be
cleaned up rapidly, but the well does not permit
the removal of the oil at the point of injection.
Dale Wilder:
There are a couple of things that I wanted to
comment on. One was in relation to the problem of
having spills that go unrecorded and repaired.
Basically, my comment is that we need to en-
courage corporate citizenship — we must make
people understand that it is really important to be
a good corporate citizen. To give you a small
example, when I was working offshore, in the old
days they got a little bit calloused about what they
did with some of their petroleum products during
the testing of some of these wells and, if a barrel
or two went overboard, they worried about it but
not enough to make them stop operations because
of the economics involved in getting out a barge
with a tank on it. This isn't all the fault of tool
pushers or of all the people in the field, but this did
happen.
After the environmental push began and we
were notified that such things were to be stopped,
the word went around that there was to be no
65
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dumping overboard of any empty barrels having a
little bit of crude oil left in them, or anything like
this. However, this didn't really solve the problem
until they told us that the tool pusher, any engi-
neer, etc. would be responsible and subject to fine
and jail. Of course, I think you realize that if I was
out on the platform and saw a man about to dump
a barrel overboard, I would run and get the tool
pusher and tell him that this man was about to
dump some oil. I would do this because it means
something to me personally. I think that once the
company really emphasized it and this went down
the line, it would work. This is the thing we have to
do with the State agency. We need to get the thing
started from the top and work it on down.
One other comment in relation to radioactive
isotope tracing—1 wonder if it might be possible to
somehow either heat up the petroleum product, or
cool it down, then run a temperature survey.
Harry LeGrand, U. S. Geological Survey, Raleigh,
North Carolina:
I was impressed with the contrast between
Dale Wilder's and John Matis's presentations. Dale
was concerned with a fairly large, extensively used
aquifer, whereas John was concerned with a number
of little problems in fairly impermeable situations—
perhaps you'd still call them aquifers. Maybe we
should analyze this particular contrast. I think that
if a water-table aquifer is fairly extensive, if it is
fairly permeable and is used extensively, then
you will have a single large problem, such as Dale
described. On the other hand, the Maryland situa-
tion for the most part was in the Piedmont Region
where the permeability is quite low. Wells are
productive for domestic purposes and also in the
valley and ridge area, it's the same way. But there
are multiple little problems in those regions and
in all probability the ground is more contaminated
than we think; we just hear about specific prob-
lems. There's no question about Dale's problem, it
will arise and we can see it. But, certainly, beneath
some of our big cities—Denver, Washington, and
others—the water-table system, whether we call it
an aquifer or not, is certainly polluted from petro-
leum products and gunk of all types in many
different ways and, in many of those places, we
don't even use the water anyway. I don't know
whether we should say that we dedicate that
ground for uses other than drinking water, but I
think the number of problems we see is really a
question of the number of complaints we hear.
Allen Agnew:
Do we have any further thoughts along this
line? I have another question that might take us
away from this theme.
66
Verne Farmer:
I just want to make one observation about
this effect of gasoline, or any hydrocarbon, in
contaminating ground water and how far down it
will contaminate. As you people may know, there's
been really a considerable amount of research—lab-
type work and field work—done on this subject in
Europe, an awful lot more than has been done in
the United States. And, actually, a great deal of
this stuff has never been translated into English,
unfortunately. I've seen some translations of some
of these articles in the last few months; most of it
is in German. I don't know what the mechanics
might be, but I think that it would be very useful
for translations to be made available to any associa-
tion or groups such as this one, that are vitally
concerned with ground water.
I think it has been demonstrated pretty con-
clusively that one of the biggest problems of
the light hydrocarbons, particularly gasoline, is the
solubility of a lot of the components. Generally,
the heavier the product, the less solubles it con-
tains, but by the time you get up to the gasoline
range, it has a lot of stuff that is soluble and, if
you end up with a body of gasoline on the
surface it will float. However, over a relatively short
period of time, these solubles will disperse down-
ward and soon contaminate this whole system. And
that, in some of the instances I have encountered,
has really been the greatest problem. We know
where the surface of the water is and, if money is
no object and the oil hasn't spread too far, we can
clean that off pretty well. But, if you have these
contaminants dissolved and diffused completely
through the whole system, there's no way to get
that stuff out other than to produce the entire
body of water in area. Now, that type of thing is
quite easily cleaned up with activated charcoal
filters, but, as Dick said, sometimes getting those
things installed and getting somebody to maintain
them is the biggest problem. However, it can be
done—there is no question about that. But that
solution of certain components of gasoline is, in
my experience, one of the biggest problems of gaso-
line contamination that we have.
Dick Rhindress:
I'd like to state at this time that the Pennsyl-
vania Department of Environmental Resources has
just started to plan a seminar. We hope to hold it
early next year, next March or April, for people
who have dealt specifically with the hydrocarbon
clean-up job. We want to get together the people
who have really worked in the field on clean-up of
gasoline and fuel oil in the ground. We are not, at
this point, considering the prevention aspects, but
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are just talking about the clean-up aspects. I would
like some input from anyone who is involved with
this sort of thing, as to whether they feel such a
program or seminar should involve also the pre-
vention aspects. This seminar will be announced
in journals like Ground Water. I'd be very happy to
hear from anyone who has this kind of problem or
can give me some ideas on what we should discuss
and how the program should be handled. The basic
concept, though, is to keep it at a working man's
level, not a formal paper and esoteric discussion
level.
Allen Agnew:
We need a lot more of that—a lot more of the
hard exchange of ideas by working stiffs—those of
us who get the dirt under our fingernails. Gentle-
men, we've been bearing down pretty hard on
hydrocarbons and, as you recognized, we did have
a little bit of exposure to pesticides in the talks
during the last two days. I wonder if we might have
any reactions or any thoughts along that line.
Max Lewallen, Agricultural Engineer. U. S. Depart-
ment of Agriculture, Watkinsville, Georgia:
I don't have anything in particular to say
about the pesticide problem. I am available to
answer questions from the floor if anyone has any-
thing to add.
Mike Bell :
i do have one question, or it may be a series of
questions, dealing with the behavior or the move-
ment of pesticides in a tight clay soil. I've heard
different comments about the movement of DDT,
the adsorption of DDT on clay, and the movement
of organophosphates. I'll ask Max Lewallen in
particular, since he was the speaker on pesticides,
but I'd also like any information from anybody
else on the movement of pesticides in general, or on
a specific pesticide in a tight clay soil.
Max Lewallen:
The literature is fairly full—quite a bit of work
has been done, there's quite a bit being done, and
yet there's lots more to be done. I think, as you
pointed out in general, that this type of material
is going to adhere tightly to the clay portion of the
soil. One thing I might add—some of my associates
at work, who have been involved for several years
with runoff from agricultural lands, laughingly say
now that runoff is a new ball game because of
past measurements having been made on total
runoff quantities instead of this being fractionated
in an attempt to correlate the more active portions
of the soil, and the clay portion in particular, to the
transport of these materials. I don't have anything
in particular to say about what you asked. I do
say that in general these hydrocarbons will be
tightly bound to the clays. It's going to depend by
and large on what happens to the clay particle
itself.
Mike Bell:
Let me just give you a specific instance on
which I was basing this question. As a result of a
fire of a storage area for both fertilizers and all
types of agricultural chemicals, we experienced a
problem of what to do with both solid wastes and
a liquid waste. And we ended up putting both the
solid waste and the liquid waste in a landfill. This
landfill was above the water table and was enclosed
in a natural clay area. What I was concerned with
is the danger to the ground water. Should we be
concerned with movement in soils like this or are
we pretty safe in what we did?
Max Lewallen:
I think as far as the larger quantities of pesti-
cides are concerned, such as you refer to, this has
not been described adequately in the literature. I
know of several groups that are interested in this
aspect of pesticide disposal right now. Perhaps you
should talk with some of the people like John
Matis here from Maryland who is wondering how to
get rid of many pounds and gallons of these source
materials, along with lots of other people. This is
an unanswered question right now, I think. In
general, in a clay soil such as you refer to, I still
personally expect very little movement of these
materials—if we're talking about reasonable quanti-
ties—and I don't know myself what I'm referring to
by "reasonable quantities." But as far as large doses
are concerned, I don't know if anyone knows what
will eventually happen to these materials.
Dick Rhindress:
I can only cite one instance of major disposal
of chlorinated hydrocarbons—in the Province of
Ontario. When Canada outlawed them, they col-
lected all DDT and associated things that they had
outlawed, and stuck them underground beneath a
large lagoon. The lagoon, to the best of my knowl-
edge is not impervious—rather, it drips out through
the bottom. These pesticides were not encased in
anything special, and apparently these eventually
are going to flush into the ground-water flow
regime. The lagoon was in glacial tills that they
felt were fairly tight. They didn't have a geologist
on the job—at least I've been told this by some
Canadian geologist friends of mine who are very
concerned about this situation. It sounds like one
of the worst possible things that can be done, ex-
cept that it sits there in the middle of an industrial
complex where nobody is using ground water.
Boy, if the containers rot off and it all goes into the
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ground water in one slug, it could really do a job of
pollution on whatever river or stream is adjacent.
It sounds like the worst possible way of handling
them.
Max Lewallen:
A point worth noting here, I believe, is the
term that is thrown around in the literature—the
half-life of these materials. I don't believe that this
term is valid in most cases, but rather it is valid
only under certain prescribed conditions. When we
don't know what the conditions are, I think it's
almost ridiculous to talk in terms of half-life of
these materials—for instance, DDT. Some people
say it has a half-life of seven years or ten years or
more.
Allen Agnew:
I'm certainly glad to have somebody question
some of these numbers that we keep putting in the
books, in the guidelines, in the rules and regula-
tions. You know, I am a geologist but I run into
very interesting textbooks on hydrology. One is by
Ray Kazmann at Louisiana State University, called
"Modern Hydrology." What he did was puncture
many of our hydrologic sacred cows, and he used
the term "dirty data." He said that our reports are
full of dirty data—data that have been collected
over the years in various ways and we have come to
accept them as the Bible. Well, about a year ago the
U.S.G.S. went through its old data and gathered
information on heavy metals. Well, they put a
disclaimer in the very front of the report in the
very first paragraph. But how many people read
that disclaimer, or how many people would pay any
attention to it? They would look down through
the tables and see the statistics of these heavy
metal concentrations, then they would take off
from that point as they would begin to gather their
new data on mercury, or whatever else they happen
to be working on. I think we need to be particular-
ly careful of this sort of thing. Well, once I've said
this, I realize that we're talking to ourselves, and
this group here probably doesn't need to be warned
of this problem. We should make sure that the
people who will use the information that we put
out realize the bounds that should be on it.
Dick Rhindress:
Off the subject—but not quite. In Pennsyl-
vania we have had several incidents where drugs
have had to be disposed of in large quantities. The
ships' stores for the whole east coast for the Navy
are adjacent to Harrisburg, and they have tre-
mendous amounts of drugs which go out of date.
What to do with them? Some of them cannot be
burned; some of them are not soluble so they
cannot be run through a sewage treatment plant;
others will wipe out a treatment plant even in small
doses. What do you do with them? So far, we've put
some in a landfill, but only the ones that we have
judiciously felt would be decomposed in a landfill
environment. Some of the others we're still up in
the air about. They're sitting over there in the
Naval Depot waiting for somebody to say what to
do with them. The Navy itself is also working on
what to do with them. I haven't seen any data on
this problem. We've had railroad cars and trucks
overturned with drugs in them; we had a fire in a
major railway yard which destroyed, or partially
destroyed, some drug shipments; and we had to get
rid of this stuff. And this stuff is probably as bad,
in its own way, as petroleum or pesticides. What do
you do with it?
Allen Agnew:
Thank you. This leads into my question. I
believe in your paper you were talking about the
cost of abatement, and you said something like—
the cost of the abatement wells and other costs
make the cost of prevention worth more than the
cost of clean-up. So what we need to do is push for
preventive programs. My question is—what kind of
preventive programs, and how do we do it?
John Matis, Maryland Department of Water Re-
sources, Annapolis, Maryland:
I've participated in a number of these inter-
agency groups where we try to decide what we
would do in an emergency situation with hazardous
wastes—if you want to call them hazardous wastes.
That term covers a multitude of sins—drugs, wastes
from hospitals, pesticides, petroleum, etc. You
really need to develop ahead of time, some type of
emergency procedure for getting rid of these things.
The trend that I've seen is toward high-temperature
incineration as the answer to everything. However,
as we know, many of these waste products have
heavy metals which are not going to high-tempera-
ture incinerate, so you're left with the heavy
metals.
Perhaps legislation to reduce supplies is neces-
sary to permit transport of the unused quantities
out of the State, out of the area. This is another
approach; it's been suggested that you have legisla-
tion requiring yearly inventories of whatever they
had not used, whether it be drugs or pesticides or
some other hazardous waste product, and that their
return to the manufacturer be permitted.
Now as far as your specific problem of
getting rid of these drugs, I would say that return to
the manufacturer would be one way of doing it.
This is one way we've gotten rid of pesticides in
Maryland—large quantities of pesticides, I might
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add, which have been condemned or made illegal
for usage, such as DDT.
In States like Massachusetts, they went on a
massive collection program and collected tons and
tons and tons of DDT and other things, and they
really don't know what to do with them now. This
is simply because they didn't have some type of
procedure developed at the time to handle this
problem. I think you really won't know until you
actually encounter the situation. Is this an evasive
answer?
Harry LeGrand:
The question arises as to whether we should
have a special burial ground for these exotic wastes
that don't attenuate in the ground as easily as
would regular sewage. I'm thinking of pesticides
and many exotic chemicals. We know that many of
our sanitary landfills are not ideally located, as far
as the best hydrogeologic criteria are concerned,
and we know that, if we have to, we could upgrade
a site location in each county to the point that we
could have a separate spot, you might say, to bury
this particular refuge. Would this be suitable?
Doug Olesen, Battelle-IMorthwest, Richland, Wash-
ington:
Battelle's prime contract is with the Atomic
Energy Commission at Hanford, and the AEC in
particular is faced with the problem of the long-
term retention of hazardous materials. Their phi-
losophy to date has been simple containment, and
they're working on a number of long-term disposal
techniques. But they definitely have adopted a
philosophy of national repositories, Hanford being
one, and there are a number of others. The Kansas
Salt Mines are also under consideration—also under
attack—but this is one obvious alternative.
Battelle-Northwest is also looking at national
disposal sites, and we're also working in the area of
hazardous materials and information systems for
EPA. Our work is more or less cataloging what is
known on hazardous materials and producing an
information-system format. EPA then is working
toward having some sort of a system on line so
that when you get a major hazardous spill in a
particular area where the man on the scene is not
particularly knowledgeable about what is spilled or
what should be done about it, hopefully this system
will be such that a simple telephone call will hook
him into a computer system and he'll be able to get
all of the specific facts, including a contingency
plan and where the particular materials or equip-
ment are located for handling the type of spill that
he has. No, it isn't liquid only. (Note: this is in
answer to "Liquid only?" from unknown in audi-
ence.) EPA's emphasis obviously has been in the
water area, because they started as FWQA, and
Battelle's work has been with EPA's Water Quality
Office so far.
Jay Lehr:
I'd like to comment on Harry LeGrand's com-
ment. Sometime ago, I espoused the idea that some-
body could make money by building treatment
plants that could handle industrial wastes, and if
the government got tough enough on the industry,
the latter would be in a position where they would
have to ship their waste to some central treatment
plant that is really equipped to take care of it. I
think we really can take care of virtually any nor-
mal industrial waste. It's just a matter of eco-
nomics. Even your sulphur liquors in the paper
industry can be taken care of, but it is an eco-
nomic problem.
Speaker not identified:
The way we're trying to do it now, in a shot-
gun approach, is ridiculous. We must look at it on a
national level. I think it can be done if we can
mobilize everybody.
John Matis:
A couple of comments on things that have
been said. Virginia and Maryland jointly are looking
at the possibility of high-temperature incineration
for handling of hazardous waste—anything that can
be incinerated. This is an ongoing project. As far as
Lehr's remark about industrial people making
money out of this, it is happening in Baltimore at
the present time. Rob Tyler, Inc. is an example-
their slogan is "We Never Refuse Refuse." They
have a site which is 80 acres or so where probably
the most toxic materials you can ever imagine have
been deposited. Well, this is really not acceptable,
and they know this, so they are trying to find
other ways. The State has forced some of the
industries which will bring in cyanide waste, for
example, to take it to areas where they could
reprocess the cyanide.
Secondly, waste oil is a big problem in Mary-
land, as it is everywhere—45 million gallons a year,
or something like this, is not accounted for. We
don't allow these in landfills for the obvious con-
tamination and hazard contamination problems.
This outfit, Rob Tyler, Inc., has built a high-
temperature incineration facility in Baltimore and
they can make money with it. They take these
things and burn them up. Of course, they comply
with the air pollution controls, but it is still a
profitable thing at the present time. If you have
the facility, or if you have the capital to build one
of these things, you can make money. Now, I think
this will probably be a short-term affair because
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States and many of the industries realize that they
do need the regional approach—they do need these
facilities to handle all this multitude of sins called
hazardous wastes. So you will see more of these
facilities being operated and, as I say, Virginia and
Maryland are talking about a joint effort at the
present time.
Dick Rhindress:
On the subject of hazardous wastes, we find
they really fall into two categories: one category is
typified by the instance I gave before, the Navy
depot that has tremendous quantities of drugs,
those we can at least store for awhile until we come
up with a plan. When somebody brings in a truck of
X chemical from Ohio on its way to New Jersey,
and it splits in half on the Turnpike and we have to
shovel it up in an hour or two and know what to
do with it so that we can get the Turnpike open
again, that's a whole different ball of wax. Some of
these chemicals have been such that we couldn't
send men in to handle them because we had to
have special uniforms and some wastes were ab-
sorbable through the skin. One was a solid, but it
was so soluble in water that we had to get it out of
there almost immediately because it was raining
about ten miles west of it on the pike and moving
toward us. These are the types of things that are
real problems.
You have to get it out of there, protect it, and
what do you do with it? We, sort of jokingly some-
times say, "Aha, we got it out of here, we got it to
New Jersey" or "back into Ohio." But this is
begging the question. You know, you can't always
just send it back to the manufacturer. That's beg-
ging the question too, because if the manufacturer
is in your State, you're going to just relocate the
problem. If he's out of State, you're just passing
•:he problem on to somebody else. This plan that
EPA and Battelle are working on, of having a
national clearing house on what to do with these
chemicals is fantastic. This is what we must have,
and we must have instant access to it, for the
emergency type situation which happens all too
often at midnight-this is when they always hap-
pen; they never happen at 9:00 o'clock Monday
morning when you can work on them.
Mike Bell:
Some things to be considered in developing a
regional approach are the economics and the condi-
tions that are necessary for transporting a hazard-
ous waste. How far does it have to go and what
precautions need to be taken? We ran into this.
Elmer Jones:
I would like to return to the problem of
pesticides in well water, and I use this term in
70
place of ground water because in every case I have
Looked at carefully, I'm personally convinced the
pesticides entered the well above the water table.
Any rain that falls today is going to contain some
DDT. Most of the water samples that we've ana-
lyzed have been below concentrations reported for
rain water. The pesticides—chlorinated hydrocar-
bons—are almost totally insoluble and very tightly
bound to particulate matter. Our findings are that
they are almost invariably associated with gross
bacterial contamination and variable turbidity with
rainfall. Neither of these characteristics are charac-
teristics of good well construction or good quality
ground water. And, as John Mads pointed out in
his talk, the initial approach with the people who
have this problem is tremendously important.
There is one well in Maryland that had a
$100,000 lawsuit over it because of the home
being treated for termites with Chlordane. We were
terribly afraid we'd end up with this in court be-
cause we had monitored this well for about three
years. It was cased with open-jointed clay-tile
casing (the lowest point in the pit adjacent to the
house was the top of the clay tile casing). The pit
received drainage from a road and off the house.
When the Health Department was first contacted
about an abnormal taste in the water, I feel this
problem would have been eliminated almost im-
mediately if the undesirable nature of this well
construction and location had been pointed out to
them, and they had been urged to have a properly
protected well constructed. As it was, awaiting
litigation, they were told by the lawyers to do
nothing to the well, so they ended up carrying
water into the house for four years while awaiting a
solution in court.
But the earth is a good filter and the question
with regard to sanitary protection of wells is "At
what point does the natural filtering ability of the
earth begin?" This is something I was concerned
about for quite some time—having dug a lot of
fishing worms in my life—that pesticides were
always found in the upper soil layers and it was
said they never moved down—and yet we know
that soil insects go much deeper than this. As it
turns out, in the deeper soil profile some of the
pesticides undergo much more rapid degradation
by action of organisms. Apparently this degradation
is sufficiently rapid so that samples taken at the
level of some of the major insects show that the
degradation rate is as fast as the pesticides move
down to this level.
Allen Agnew:
Elmer, I think that you've put the finger on a
subject that the N.W.W.A. is particularly happy to
see emphasized—that is, improved construction of
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wells. This is one of the cardinal points that
N.W.W.A. has stood for and, in working with the
State associations of water well drillers, this is one
of the points they've attempted to get across. You
recognize that the State associations unfortunately
don't represent all the drillers in the State, or all
the well diggers. So we've got a big job to do back
home and I think that the N.W.W.A. will be pretty
happy to see the kind of emphasis that we are
putting on it at this session.
Now, we're approaching our close—you re-
member that when Lady Godiva came roaring down
the street naked on her horse, she said, "I approach
my clothes." She spelled it differently from the
way I spelled it just now. It is 9:30—the time that
I had hoped would be our close here, but we still
have some people who haven't talked and I'm sure
that you've got some things to say that are so
pregnant that you just can't stand not to say them.
Dick Pearl, Colorado State Geological Survey,
Denver, Colorado:
I was just wondering if any of you people
from the East have had any contact »vith
any research being done on degradation of DDT in
the soil by any means? The reason I ask is that
research is being carried on up at Colorado State
University and, if my memory serves me right,
they're finding that cow manure is a very useful
agent in this. It destroys DDT very rapidly in the
soil, and I was wondering if there's anything else
that maybe you've found that does the job.
Max Lewallen:
Elmer Jones has already provided you with
some of that information. There is quite a bit of
that work being done presently. One other thing I
might mention—you referred to cow manure—I
believe alfalfa meal has been in the literature also
as one of the things that aid in degrading some of
these materials. But, when we talk of the degrada-
tion of these materials, it's a similar situation to the
half-life that we referred to awhile ago. You're
talking about very specific conditions on the
degradation of any of them which can be either a
fast or slow degradation. For instance, I remember
reading over a report where in one particular
instance DDT was being used in a tropical climate
for the spraying of mud huts and the problem there
was too short lived, under those conditions.
Verne Farmer:
Is DDT not all as bad as the newspapers say
it is?
Elmer Jones:
I think this is a yes-or-no type answer. DDT at
high pH can be very rapidly broken down by
hydrolysis. This is a condition you will not find
in nature. A large number of very common an-
aerobic organisms, E. coli being one of them, can
break down DDT. The problem with DDT in the
environment has been largely with what you might
call the "accidental fraction. "The pp DDT, and I'm
not going to attempt to define this because I am
not an organic chemist, is the desirable pesticide.
The op DDT is the accidental portion and depend-
ing upon the manufacture and the date of manu-
facture, this will run from 5 to 20% of the active
agent. Unfortunately, in the environment, this is
so similar to certain female hormones that it (not
the pp but the op) has had an effect on maturity
and sexual activity of wild life. The thing that has
been a real bugaboo, and I think that perhaps last
year we may have seen a pesticide backlash (now
this is a personal opinion, not an official Depart-
ment of Agriculture policy statement), because of
the publicity on DDT, its persistence, a coming
ban, and a lack of a good substitute in some cases—
perhaps some farmers have tried to put on enough
to last five or six years.
It is impossible to describe normal conditions
but perhaps normally 50% of the DDT applied to
an area will be lost to the atmosphere within 48 to
72 hours. As you know, they talk about finding it
in the Arctic for seals and in places that they are
sure no pesticides were ever used. The English have
done much more work on pesticides in the atmos-
phere than we have. Their findings are that in the
atmosphere, its average life, or half-life, is long
enough for it to go around the world about three
times. I talked about it in rain water because I'm
concerned with pesticides in water, but these
Englishmen, Adkins and Eggleston, estimate that
about eight and a half times as much is removed
from the atmosphere by deposition as by rainfall.
So you have a continual replenishment over the
earth's surface of DDT and, until you know this
rate of replenishment on the surface, you cannot
accurately calculate the survival of this in the soil.
I think this has been a complicating factor, but in
the last two years there has been more and more
information on the degradation of these, and the
anaerobic environment which we don't find in our
agricultural soils is much more conducive to such
degradation.
A good example of this is when my project
on pesticides was started by Robert Egan of the
Maryland State Health Department, hetrachloric
peroxide was frequently found in water supplies in
the Hagerstown Valley. When this was banned from
use on alfalfa, even though it persists in the soil for
a long period of time, our detecting it in water
supplies essentially cleared up within the year. The
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question is not so much the persistence, but the
damage that it can do in its lifetime. And this is
because of its mobility, especially with regard to
water; you cannot make DDT stay in pure water.
It will be carried out by a process known as co-
distillation. The DDT has a very low volatility, but
it will be attached to the water molecules going off.
John Mat is:
I have a question for Lewallen or Elmer Jones.
If DDT goes around the world three times before it
is finally degraded and it comes down in the rain
water, it would seem to have some kind of impact
on photosynthesis in general, whether it be in the
oceans or in lakes or standing water bodies. Is this
true, or not?
Stan Ursic, U.S. Forest Service,Oxford. Mississippi:
We have had some people working on the hard
pesticides as applied to forest land, and they have
found that the persistence is very low, as measured
in surface water from measured water sheds. They
don't detect the hard pesticides after a matter of a
few days, due to the high biotic activity, especially
within the forest floor.
If I may continue, I have a question and a
comment. It seems that most people at this Sym-
posium are geologists, hydrologists, and engineers.
The one paper we didn't hear today was by a re-
search chemist. For a neophyte getting into the
field, I'd like to hear comments on your experi-
ences about what to do to get reliable chemical
analyses. I realize that you can go out and hire a
Ph.D. chemist, but perhaps this isn't always the
best solution, unless you're a big outfit like ARS.
What are your experiences? Do you go to State
agencies for your analyses? Do you go to private
firms?
My other comment is, I was a little disap-
pointed in not hearing anything at all this evening
about industrial wastes, and this seems to be a
problem that is certainly as important as gasoline
spills. For example, I know that International
Paper Company, between 1970 and 1974, will
plan to spend $100 million on pollution control
alone. This is just one paper company—it happens
to be a big one—but there are others, quite a few.
Are we neglecting this area? Are we skirting this
area for any particular reason?
John Mat is:
Industrial wastes include a large number of
things, very complicated wastes. Those of us who
are interested in petroleum know that we have
waste products. I'm familiar with waste oil. This is
an industrial waste, and it is a very severe problem.
I do know that many of the petroleum companies,
72
at least in the Baltimore area, are spending very
large amounts of money on pollution control meas-
ures. There obviously have been occurrences in the
past which have created ground-water problems—
these are really what we're concerned with. It's
well documented that many of these waste lagoons
have caused phenolic concentrations in the ground
water beneath. When you say "industrial wastes"
exactly what are you thinking of? It can include
many, many things.
Stan Ursic:
Well, I was thinking of the whole gamut—the
paper industry, the people who make these hard
pesticides that we're talking about. You are all
familiar with the Mississippi River kill, and this sort
of thing. I'm speaking of industrial wastes in
general.
John Matis:
One point which has become very obvious to
us in Maryland; when you turn off all the spigots
and all the discharge points into the surface water,
the liquid waste has to go somewhere. I think Dr.
Zanoni made this point—every waste has to go
somewhere. And at the present time, with the very
restrictive surface water laws, most of it is no longer
being transported in water; it is going on the
ground, and this is really our concern, whether it is
pesticides, or washings from pesticide formulator
plants, or from petroleum plants. It's going on the
ground. This is indeed a problem and, as far as I
know, in the northeast corridor from Washington
up to Boston, with which I am familiar, this prob-
lem has not been evaluated. It includes chromium,
steel plants, paint, and all kinds of chemical works.
It has not been evaluated; people know it exists,
and it could very well be the most severe problem
that we're facing in ground water.
Max Lewallen:
I might contribute to his query concerning the
analysis of these materials. I frankly know of no
easy route to analysis of pesticides. If we're talking
about controlled conditions, controlled experi-
ments, known quantities, known pesticides being
used, it is a much easier problem than say, if we
start with a completely unknown sample. As you
might well know, we've had analytical problems; a
lot of others in the pesticide business with whom I
have talked have analytical problems also. There
are unresolved points. A lot of times in pesticide
analysis if we stick with common compounds and
known compounds, it eliminates troubles quite a
bit. Others might want to make some comment
with regard to pesticide analysis.
-------
DougOlesen:
We had a similar problem with Acrolein in a
study that we were doing. The first year's work was
based on analytical techniques that were supposed-
ly acceptable and, after a full season of sampling,
we discovered that it was a field problem. We dis-
covered that the actual analytical techniques were
not successful and we had to do a fair amount of
basic research and go through and develop a com-
pletely new technique for Acrolein. I think a lot of
people face the same problem. There's nothing to
draw on; you just have to go it on your own until
you can develop something that is satisfactory. We
did document this and it is available now for other
people, but many pesticides you run up against are
likely to force you to go through that same
procedure.
Stan Ursic:
Thank you. I was also thinking of just the
routine analysis of the common cations and anions
as well, rather than some of the more sophisticated
or exotic chemicals.
Allen Agnew:
Mr. Ursic, it seems to me that EPA just recent-
ly reissued the second edition of analytical meth-
ods, or techniques—that big, spiral-bound manual
that FWPCA put out 3 or 4 years ago, which con-
tains standard analytical methods and apparently a
re-evaluation of these methods. EPA has been doing
some soul-searching too, in the last 3 or 4 years on
methodology, both at the Evansville Station and
the Wheeling Station that I know of, on the Ohio
River. And the U. S. Geological Survey, of course,
has Hem's Water-Supply Paper on Analytical Meth-
ods. So there are two major reference works, and
I am sure that there are others; however, you still
have the problem of the bench chemist—getting
reproducibility of results, and the fact that some of
them feel more at home with a certain analytical
method than with others. So you really have to
identify the methodology and the lab that's run-
ning the analyses, as you use the information in
your report.
John Matis:
I'd like to make a few comments on analyzing
petroleum. With the gas chromatograph (I really
didn't go into this in my presentation), you can
analyze things in terms of the light fraction or a
heavy fraction. In other words, something which
falls in the range of a C-4, C-6, C-8 compound and
something which is up around a C-12 compound.
This does not identify the specific product. In
other words, if you have an unknown petroleum
contaminant in water, you cannot identify it in
minute quantities now. If you don't know what it is
(in other words, it might be a kerosene, gasoline, or
fuel oil), you are stuck because the kerosene, gaso-
line and this No. 2 diesel fuel (which is really a
kerosene) fall within the same range of identifica-
tion by your gas chromatograph techniques. This is
a real problem. The infrared spectrophotometer
technique requires that you isolate this stuff with
some type of organic solvent—chloroform has been
used. A number of papers have been written on
this, many of them unpublished, by this Kankawi
group in Europe, but more recently by Crider with
Standard Oil of California.
And you need a large volume of sample to
concentrate, let's say 0.1 ml; I don't know if this
came across in my talk. Now this assumes that
nothing volatilizes in the meantime, and that you
can keep the solution; their technique has been to
get so many milliliters of chloroform or organic
solvent, collect the water in the same bottle, and
then draw out the solvent and analyze this concen-
trate, boil it, reconcentrate the material and then
analyze it with the gas chromatograph infrared
spectrophotometer.
There is a real problem, though, with identi-
fication and sampling. Now, we have been faced
with the situation where we really never did resolve
a number of incidents where we suspected it was
kerosene or gasoline, because of this problem. As a
result, very little legal action could be taken. I
don't know if this clarifies our sampling techniques.
Dale, you may want to talk about your experience
in California.
Dale Wilder:
A couple of things have come up that I did
want to talk about. One deals with sampling tech-
niques-we found that, among other things, we had
a very difficult time in estimating how much gaso-
line was in the well, and also which wells had! the
taste and odor of gasoline. Part of the problem is
that when you're out in the field sampling 70 wells,
it is a difficult procedure cleaning up your M-scope,
or whatever you're using, to measure the levels
with. Of course, much of this is just developing a
standard practice of carrying detergents or what-
ever it is that will cut the gasoline and get rid of
the odor.
The other thing, mentioned earlier, is the cost
of preventive measures in comparison to the cost of
the remedial action. I mentioned in answer to one
of the questions that was asked that $700,000 had
been spent by WOGA. This is not an overly large
amount of money, as far as the petroleum industry
is concerned, except that this is just a small part of
the total clean-up that was involved. There were
73
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several agencies who went ahead on their own and
did what they thought they could. Also the Depart-
ment of Water and Power has done this to insure
that their wells will remain free from gasoline. In
addition to this, WOGA requested that we do some
monitoring for them. But, the point is that in the
past it has tended to be quite an economic con-
sideration, but now it has become more economical
to make sure that it doesn't get spilled in the first
place. It was a little hard to justify going ahead and
^pending this money. I think that we need to put
forth a real effort, as an organized group, to make
sure thac economics isn't the only consideration
that companies look at when they are deciding
about preventive maintenance.
Doug Olesen:
The business of tying economics to environ-
mental considerations has just become official
policy because of the recent Calvert Cliff decision—
that was a lawsuit by interveners against the Calvert
Cliff nuclear plant, where the AEC and other
government agencies actually lost the case and were
accused of absolute neglect in terms of the National
Environmental Policy Act. One of the things that
came out of this decision is that all environmental
impact statements now—in essentially all industry-
will have to have an economic consideration tied to
the environmental impact statement, so that it will
actually be an economic trade-off for various
alternative actions that industry can pursue.
Elmer Jones:
I want to add my comments on the analytical
services. This is a problem because of the expense
of the equipment involved. I think there is a real
need for more environmental monitoring. If we are
going to protect our environment, we need to know
what is going on. Because of the shortage of quali-
fied personnel and the cost of the exotic equipment
needed to test in the parts per billion and parts per
trillion range, consideration should be given to
regional analytical services where you can have a
well-equipped and well-staffed lab with people of
high caliber to train the next generation of ana-
lytical chemists for environmental monitoring.
Mike Bell:
I apologize because the time is running late,
but 1 do have an important question that I think
needs consideration, going back to contamination
of ground water by gasoline. What happens when
the gasoline gets into the ground? How far can we
expect it to go; what conditions in the ground
determine how far it goes: what happens once it is
there as far as its movement; does it degrade; it is
just there-, what can we expect once it is in the
ground?
74
Dale Wilder:
In our experience, it appeared that the gaso-
line was very mobile. However, because of the
residual that was left behind, it tended to dissipate
itself. That is, a certain percentage of it would be
left behind in the pores that it traveled through,
and so the distance it would travel would depend
very much on the volume that was originally
present. As far as what happens to it after it is in
residual form, this is part of the problem that we're
having. It appears that certain organisms can de-
grade it. Whether it degrades on its own, I don't
know.
John Matis:
In the case near Los Angeles which I explained
in my talk, the gasoline had been sitting there for
at least three years, or maybe for as much as ten
years. It did not move out of the area. It sat there
as a pocket of gasoline and did not degrade appre-
ciably. In another case where I personally examined
the well—it was a small area perhaps one acre in
size—the gasoline had been sitting there for at least
six years, and the people's wells were still contami-
nated with strong odor and strong taste. So there
was a definite problem. The gasoline did not move,
as you might have imagined and as Dale Wilder has
indicated; the movement was limited. I don't know
why this is true. I think the people in Europe are
working on that particular problem.
Doug Olesen:
We face a similar problem with radioactive
waste, where it doesn't move with the water. Some
things move at something like I/1,000th the rate of
the water movement because of the soil-waste inter-
action (adsorption, precipitation—there are a lot of
things going on). In addition to biological degrada-
tion, we are dealing with an organic material. But
it always comes back to the fact that the key to
the answer has to be that you have to be able to
satisfactorily describe a velocity pattern and the
flow of the water system. If you can do that, then
you can deal with the soil-waste reaction that is
going on and try to make some prediction that the
contaminant itself will move at some fraction of
the speed of the water. It's always going to go
where the water goes, but it may not go as fast, and
that is the crux of the matter; but the key is know-
ing where the water goes.
On one other observation, it seems everybody
is talking about contingency plans for dealing with
emergencies of contamination or pollution of
ground water. This could be an excellent recom-
mendation from our group—a contingency plan to
deal with emergencies, be it in Washington or North
Carolina or California or Maryland or wherever.
-------
Harry LeGrand:
Well, we have' contingency plans when it
comes to a snowfall hazard, and we have piles ot
salt and sand on the ro'ad. I can visualize piles of
clay, or something like that to help mop up some
exotic chemical, but I hope we don't have cow
manure piles to take care of the pesticides, as some-
one suggested earlier.
Allen Agnew:
I move we adjourn with that one. I want to
thank everyone, for1 contributing your thoughts and
pointing out the failings and the fallacies that we
are living with. We mentioned earlier the term
"corporate responsibility." I would like to remind
us that we also need to have individual "citizen
responsibility"—for example, our own municipal
waste-treatment plants, when we taxpayers won't
vote the bond issues necessary to clean up our
wastes. We are some of the worst polluters that
exist around here. Gentlemen, let's all put the
wheel to the shoulder — or some other mixed
metaphor — and get on with the job. Thank you.
/5
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Ground-Water Pollution Potential of a Landfill
o
Above the Water Table
h c
by Michael A. Apgar and Donald Langmuir
ABSTRACT
A study of the character and movement of landfill
leachate through unsaturated soil was begun in 1967 at the
State College (Pennsylvania) Regional Sanitary Landfill
which has operated since 1962 employing the trench
method of waste disposal. The landfill occupies a gently
sloping underdrained valley with a water table more than
200 feet below land surface. Precipitation averages about
37 inches as rain per year. Residual sandy-clay to sandy-
loam soils range from a few feet to greater than 70 feet in
thickness on a sandy dolomite bedrock. Soil moisture
samples were extracted at different depths from beneath
two of the refuse cells using suction lysimeters. Water
samples were also bailed from these cells and pumped
from a water table well beneath the landfill. Monthly or
less frequent analyses performed on water samples included
Eh, pH, temperature, specific conductance, BOD, Cl, SC>4,
total alkalinity, NH3, NO2, NO3, PO4, Ca, Mg, Na, K, and
total Fe. Soil samples from beneath the refuse were sub-
jected to particle size and x-ray analysis, and chemical
analysis of soil pH, soluble salt content, exchangeable Ca,
Mg, Na, and K, cation exchange capacity, and extractable
P content.
The study showed that the quality and quantity of
leachate beneath a landfill varies considerably with the
topographic setting of landfill trenches or cells. Leachates
2 feet under an upslope cell which received only direct
precipitation, had the following maximum values 3-13
months after refuse burial: specific conductance 8445
jumhos, Cl 1890 mg/1, BOD 3300 mg/1, NH3-N 540 mg/1,
and total Fe 225 mg/1. Upon reaching a depth of 14.5 feet
after about 2V4 years or more, maximum values of these
species in the leachate had been reduced by 83%, 80%,
> 99%, > 99%, and 98% respectively. In contrast, more
water, including precontaminated surface and subsurface
runoff from adjacent upslope cells, infiltrated a downslope
cell, saturating the refuse. Even after moving downward in
the soil to a depth of 36 feet in 7 years, the leachate beneath
this cell had a conductance of 6600 /imhos, 600 mg/1 Cl,
over 9000 mg/1 BOD, 40 mg/1 NH3-N, and 100 mg/1 total
Fe. A practically continuous depletion of inorganic species
in the refuse as indicated by the quality of leachate from
both cells has occurred with time. However, concentrations
of BOD and redox sensitive species such as Fe and NH3 in
the leachate have fluctuated in response to changes in the
moisture content and temperature of the refuse.
Presented at the National Ground Water Quality
Symposium, Denver, Colorado, August 25-27, 1971.
"Research Assistant, Department of Geosciences, The
Pennsylvania State University, University Park, Pennsylvania
16802 (presently Hydrogeologist, with Roy F. Weston, Inc.,
West Chester, Pennsylvania).
""Associate Professor of Geochemistry, Department of
Geosciences, The Pennsylvania State University, University
Park, Pennsylvania 16802.
Leachate beneath instrumented cells is moving down-
ward in the subsoil at the rate of 6-11 ft/yr. Observed
mechanisms of leachate renovation during this downward
percolation, along with supporting evidence for each listed
parenthetically, include: dilution and dispersion (decrease
in Cl with depth); oxidation (Eh and pH measurements,
decrease in BOD and Fe with depth); chemical precipitation
(decrease in soil extractable P after leachate percolation);
cation exchange (increase in percent base saturation of
clays affected by leachate, and depletion of NH3 under
reducing conditions—bacterial growth may also retard or
remove NH3); and anion exchange (decrease in SO4 with
depth). Removal of bacteria, suspended ferric oxyhydrox-
ides and other particulates by soil filtration undoubtedly
also occurs. Although renovation takes place, it is incapable
of preventing highly contaminated leachate from moving to
depths of 50 feet or more in soils beneath downslope cells.
Ground-water contamination has occurred, probably by
leachate channelled down fractures in locally shallow bed-
rock, or by leachate-contaminated runoff from heavy storms
which has entered sinkholes or infiltrated along the valley
bottom. The study shows that improper design of landfills
emplaced above the water table in relatively permeable
soils and bedrock such as are found in many carbonate-rock
terranes, can result in serious ground-water pollution.
INTRODUCTION
Ninety percent of all municipal solid wastes
generated in the United States are disposed of on
land. About half this total goes into landfills, the
rest to open dumps (Hershaft, 1969). In the near
future as public outcry against open dumps be-
comes more universal, most of such disposal will
also give way to landfilling. Thus landfilling will be
the prevalent method of solid waste disposal in this
country for many years to come.
A sanitary landfill is defined as an engineering
method of land waste disposal which creates "no
nuisances or hazards to public health or safety"
(American Society of Civil Engineers, 1959). How-
ever, in practice any operation in which refuse is
compacted and covered with soil on at least a daily
basis is considered a sanitary landfill. Landfills are
indeed more sanitary than open dumps in terms of
controlling odor, fires, and vermin, and in permit-
ting site reuse. However, leachate produced in the
decomposition of refuse in dumps or landfills may
pollute surface and ground water. The nature of
such pollution will depend on whether the de-
composition process takes place in the presence of
atmospheric oxygen or soil air (aerobic) or in the
76
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absence of oxygen (anaerobic). Aerobic decay
produces stable end products such as CO2, NO3,
SO4, H2O, and a relatively inert residue. Anaerobic
decay produces CO2, methane, ammonia, hydrogen
gas, alcohols and organic acids, and other partially
oxidized organic species which exert a high BOD
(biochemical oxygen demand). Metals such as iron
and manganese are mobilized and may be concen-
trated in such reducing environments.
Refuse cells usually become predominantly
anaerobic shortly after emplacement (Merz and
Stone, 1962). In general, conditions are relatively
aerobic near the surface of a refuse cell and become
increasingly anaerobic towards the bottom. How-
ever, within refuse cells unsaturated by water,
traces of oxygen are often present, so that zones
and pockets of anaerobic and aerobic decay will
exist side by side at any depth (Merz and Stone,
1966).
Leachate quality is influenced by the compo-
sition and amount of refuse, its sorting and degree
of compaction, the amount of water in contact
with it, and the temperature. Refuse constituents
which affect leachate quality include biodegradable
organic matter (chiefly vegetable and animal
wastes), soluble inorganic materials, and redox-
sensitive substances such as most metals. The com-
position of a typical municipal refuse is given in
Table 1. In general, the thicker the refuse, the more
polluted the leachate issuing from it (Quasim and
Burchinal, 1970). The manner of sorting of the
refuse is important insofar as reactive materials
such as the biodegradable organics in garbage may
be isolated by relatively inert materials such as
paper. Paper also absorbs and holds water which
would otherwise promote the decomposition of
other organic materials.
Table 1. Sample Municipal Refuse Composition —
U. S. East Coast (after Kaiser, 1967)
Weight
Physical Percent
Cardboard
Newspaper
Miscellaneous paper
Plastic film
Leather, molded
plastics, rubber
Garbage
Grass and dirt
Textiles
\TJf\nA
wood
Glass, ceramics, stones
Metallics
7
14
25
2
2
12
10
3
10
8
Rough Chemical
Moisture
Carbon
Hydrogen
Oxygen
Nitrogen
Sulfur
Glass, ceramics, etc.
Metals
Ash, other inerts
Weight
Percent
28.0
25.0
3.3
21.1
0.5
0.1
9.3
7.2
5.5
100.0
100
Water cannot readily enter refuse which has
been highly compacted. Such refuse settles less
after burial and is less susceptible to channelling
and to changes in permeability than less dense
material. Compaction also reduces the rate of
atmospheric O2 diffusion into the cell and thus
favors anaerobic decay of the refuse.
Water content determines the rate of refuse
decomposition, and whether the process is pre-
dominantly aerobic or anaerobic. Dobson (1964)
reported that the maximum oxygen uptake by
microbial decomposition occurred in refuse with
40-80% moisture content. The maximum decompo-
sition rate was observed at a moisture content of
60%.
Water content of the refuse is a function of its
initial moisture content, water produced in decom-
position reactions, ground water which may enter
the refuse, infiltration of precipitation and runoff
through soil cover, and lateral flow in the soil. The
amount of recharge to the refuse cell is determined
by the permeability of the cover material and the
topographic setting, among other factors. Vegeta-
tion, or leaf mulch cover disposed of on the site
will prevent rapid storm runoff, and thus may
increase infiltration to the buried refuse. Vegeta-
tion, however, will also reduce the water content
of the refuse through transpiration.
Most water which infiltrates a refuse cell will
not appear as leachate until all the refuse layers
have reached field capacity (Remson, Fungaroli,
and Lawrence, 1968). However, some leachate is
produced immediately after refuse burial by com-
paction of initially wet refuse or channelling of
water through the refuse (Lane, 1969).
Reduction in the permeability of the cell floor
may cause water to pond in refuse buried in un-
saturated soils. Such permeability losses result from
compaction and smearing of the soil by excavation
and landfilling equipment, from precipitation of
gelatinous ferric oxyhydroxides, or formation of an
organic slime on the trench floor (McGauhey et al.,
1966; Lane, 1969).
Temperature exerts an influence on leachate
quality by controlling the rate of bacterial activity.
Microorganisms are able to grow in refuse over the
temperature range 5-55° C, but the largest number
grow between 15-30° C (Dobson, 1964). A drop of
5°C results in a 10-20% decrease in the rate of
bacterially - controlled oxidation (Camp, 1963).
Thus, significantly less BOD is produced in a landfill
in a temperate climate during winter and spring
months than during the summer and fall (Langmuir,
Apgar, and Parizek, 1971).
Burial of refuse in direct or intermittent con-
tact with the zone of saturation has repeatedly
77
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been shown to cause serious contamination ot
ground water. Unfortunately, natural depressions
and excavations which intercept the water table
are frequently employed as waste disposal sites.
Well documented cases of ground-water pollution
resulting from such disposal have been reported in
New York (Carpenter and Setter, 1940), California
(California State Water Pollution Control Board.
3954), South Dakota (Andersen and Dornbush,
1968), and Illinois (Hughes et a!., 1969). Saturation
of the refuse by ground water not only permits the
ready solution of inorganic material but also favors
exclusively anaerobic decomposition of the organic
wastes present with the formation of reduced and
highly undesirable organic and inorganic substances.
In contrast, reported instances ot ground-
water pollution from landfills situated above the
water table are virtually nonexistent. Thus, until
recently it has been widely assumed that a tew ieet
separation of refuse from underlying ground water
is sufficient to prevent water quality problems
(California State Water Pollution Control Board,
1954; Andersen and Dornbush, 1968; New York
State Department of Health, 1969). This may be
true in scmiarid climates where significant amounts
of leachate are seldom produced above the water
table. However, landfills located in humid environ-
ments can be expected to produce leachate which
may percolate to the water table without sufficient
renovation to avoid ground-water pollution (Emrich
and Landon, 1969).
Ground water in carbonate terranes is particu-
larly vulnerable to pollution by landfill leachates.
Carbonate rocks may weather to produce residual
soils the thickness of which depends on the abun-
dance of noncarbonate minerals in the parent rock
and the extent of subsequent erosion. When these
sons are present above the water table, they might
be expected to minimize ground-water pollution by
dispersing and retarding leachate flow and facili-
tating its aerobic renovation. However, carbonate
bedrock may be locally shallow or exposed and
often has solution enlarged joints and fractures
ranging to cavernous in size. Such bedrock provides
direct avenues for movement of raw leachate to the
ground water with little if any opportunity lor
improvement in leachate quality. Further, solution
enlarged openings in carbonate bedrock can permit
Icachate-contaminated ground water to travel great
distances rapidly and without filtration.
PURPOSES OF THIS STUDY
An investigation of the ground-water pollution
potential of the State College Pennsylvania Region-
al Sanitary Landfill has been pursued since 1967
by the Pennsylvania State University in cooperation
with the Pennsylvania Department of Environ-
mental Resources (formerly the Pennsylvania De-
partment of Health). Purposes of the study which
will be considered in this report include:
1. Examination of the quantity and quality of
leachate produced in a humid-temperate climate by
a landfill in unsaturated soils.
2. Determination of the rate of stabilization
of such a landfill as evident from changes in the
quality of its leachates with time.
3. Study of changes in leachate quality with
depth in underlying soils to identify the extent
and principal mechanisms ot natural leachate reno-
vation.
4. Evaluation of the possible extent of ground-
water pollution by landfill leachate at a site with a
deep water table in a carbonate rock terrane.
The study was begun by R. R. Pari/.ek and B.
Lane. Results of the research for the period Octo-
ber 1967 to July 1968 have been summarized by
Lane and Pari/.ek' (1968), Lane (1969), Emrich and
Landon (1969), and Parizek and Lane (1970).
DESCRIPTION OF THE STUDY AREA
The State College Regional Sanitary Landfill is
located 1.8 miles northwest of State College in
Centre County, Pennsylvania (Figure 1 ). Also shown
in the Figure are areas in the State directly under-
lain by carbonate rocks which as noted are uniquely
vulnerable to ground-water pollution. The study
area averages 37 inches of precipitation as rain per
year, distributed with a slight excess during summer
months. Of this 37 inches about 5 inches fall as
snow, generally between the months ot November
and April. Mean monthly temperatures range from
a low of-2;' C in January to 22" C in July.
Fig. 1. Location of the State College Regional Sanitary
Landfill (see also Figure 23!, and major areas underlain by
carbonate rocks in Pennsylvania.
78
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The Landfill site, the southwestern half of
which is shown in Figure 2, occupies 108 acres, or
most of a small valley on an upland ridge in the
center of a broad, carbonate vallev called Nittany
Valley. The bottom of the small valley is dry and
underdrained and contains surface liows only a
few times a year after the heaviest storms. Land-
filling is done along the valley sides, the tops of
which parallel the dry stream bed. The valley walls
are about 60 feet high and slope 7-10'" toward the
stream channel.
Access Roods
— — — Property bounaofy
Fig. 2. Map of the southwest portion of the State College
Regional Sanitary Landfill, showing locations of holes for
the 1962 and 1967 lysimeter networks, the 1962 cell tap,
and the deep well.
Ground water exists under water tank condi-
tions at a depth of about 200 feet in the bedrock
beneath the dry stream valley. Bedrock is the Upper
Sandy Member of the Gatesburg Formation of
Cambrian age, an interbedded series of dolomites,
sandy dolomites and quartzites. Residual soils
developed on this unit range from 0 to greater than
70 feet in thickness. Although bedrock does not
outcrop on the landfill property, it immediately
underlies the buried refuse in some places.
Local soil textures range from sandy ioam to
loamy sand (Lane, 1969). However a typical soil
profile is very heterogeneous and may in addition
include lenses of sand or clay, large quartzite or
dolomite boulders, and occasional i.!r,\\e-;ther?d
ledges of quart/ite or dolomire. These units control
the rate and direction of soii moisture movement'
beneath the landfill. Sandy units allow mp.u move-
ment and channelling. wh:lc clavey kn^cs .'nd rock
ledges retard or deflect soil-water mo\t.;-iei:t -'Lane
and Parizek. 1968).
Before 1962, the Borough of '-.n< College
used the southern end of the present i mdhll tract
as an open dump. In 1962. all exposed n. rnse was
covered, and the site has subsequently operated ,"•
a sanitary landfill. Five townships si: r'-o'inding State
College have also disposed of their refuse at the
landfill since January, 1967. !r 197^ about 100
tons of refuse were brought to the site c.icii day tor
burial.
The landfill is operated by the ••••_:,ch mcthoc;
(American Society of Civil Engineers. I 9;)°). Indi-
vidual refuse cells arc about 30 ieef \\ <:ie. 12 to 16
feet deep, and range from 200 to 1200 :eet ir
length. Inert, bulky material including demolition
debris and tree stumps are dumped ;n separate
areas of the landfill to conserve trench MXICC.
Refuse eel's are covered with a fiin' :.;• er ot com-
thickness. Leaves garnered each fall arc spread over
the completed cells as mulch cover. Final restora-
tion involves planting evergreen seedlings through-
out the area, although nauir.ii p':'^ and shrur.
vegetation predominate about 5 years alter burial.
WATER AND SOIL SAMPLING METHODS
Water Sampling Methods
Soil moisture samples for this study '-vere ex-
tracted by means of suction iysimeters from be-
neath landfill cells which had been emphced m
1962 and 1967. The design and operation of suc-
tion Iysimeters ha^e been described in detail by
Lane and Pari/.ek (1968), and Parizck and Lane
(1970). Ihe cross section of a lysimeter is shown in
Figure 3. The device, which can hold .1 liter ol
water, consists of a plastic cylinder 25 inches long
and 2 inches in diameter, with a 2.5 inches long
porous ceramic tip or cup. So:i moisture is dwn
through the powdered quartz and the ceramic tip
into the lysimeter by the application of a vpcuum
greater than the soil moisture tension through the
pressure-vacuum tube A sample is then forced to
the surface for collection by exerting a gas pressure
on the pressure-vacuum tube. As noted by Lane
(1969) the pore diameter of the ceramic tip is
approximately 1 micron or less. Thus, most col-
loidal-sized particles can enter the sampler; how-
ever, many particular.es including bacteria and
perhaps some BOD active substances are excluded
from sampling.
79
-------
PRESSURE-
VACUUM
GROUT
BACKFILLED
SOIL
SAMPLE OUT
TRENCH WALL
/4 NYLON TUBE
RUBBER CORK
PLASTIC BODY
POWDERED
QUARTZ
__ POROUS
J CERAMIC TIP
Fig. 3. Cross section of a suction lysimeter, modified after
Parizek and Lane (1970),
26'
PL&ST1C LINER
OVER TRENCH BOTTOM
PLAN
FLOW OF LEAGHATE
< UNCONTAMINfiTED
SOIL WATER
CROSS-SECTION
Fig. 4. Plan and cross section of the 1967 cell leachate
collection and sampling installation (modified after Lane
and Parizek, 1968).
The 1967 cell lysimeter network and leachate
collection facility were designed and installed by
Lane and Parizek (1968) (see also Lane, 1969). A
generalized plan and profiles of the installation are
shown in Figures 4 and 5. Prior to emplacement of
refuse a plastic liner of double thickness six-mil
polyethylene was laid along the bottom and 6 feet
up the sides of the trench to collect and conduct
leachate towards the lysimeter network. A gal-
vanized iron spreader pipe directly above the
network received and distributed the leachate even-
ly into a gravel-filled trench from whence it
filtered downward through the soil towards the
sampling points. A cross section of the lysimeter
sampling network beneath the 1967 cell is shown in
Figure 5. Pelletized bentonite was placed at inter-
vals between lysimeters during backfilling of each
hole with native soil to prevent leachate channelling
to the sampling points. Sampling tubes from the
lysimeters were completed in a protective wooden
housing set on a concrete foundation on the floor
of the landfill trench (Figure 4). After the refuse
had been emplaced to a depth of 10 feet in No-
vember 1967, access to the sampling tubes was
accomplished by raising the hinged roof of the
housing.
SL-4
D-..,
y_ 9.
J-.S-
1
•
'
1
-2*
- 4'
-
L
!1
'-lO.S'
- 3'
-10'
-13.5'
--17'
K
*- 01
LYSIMETER
DEPTH BELOW REFUSE
I.
Fig. 5. Cross section of the 1967 cell lysimeter network
(after Lane and Parizek, 1968).
80
-------
A second lysimeter network was installed in
November 1969 below a landfill trench filled
during 1962. Shown in Figure 6 are the relative
positions and depths of lysimeters installed in the
six boreholes drilled through the refuse. Six-inch
steel casing installed in each hole prevented water
perched in the refuse from moving down the open
holes. Either bentonite pellets or polyester resin
(Rohm and Haas P-463) was emplaced at intervals
as grout during backfilling of the holes with native
soil to isolate the individual lysimeters. Thermistors
were also positioned in the holes to measure
changes in temperature with time and depth. Sam-
pling and pressure-vacuum tubes for the lysimeters
and the thermistor leads were completed just above
the land surface in the steel casings which were
covered with padlocked, hinged steel caps.
Water ponded in the 1962 cell refuse was
sampled from a sump or tap (Figure 2) drilled into
the cell, but not through its floor.
The deep monitoring well located in Figure 2
was drilled near the center of the landfill area in
November, 1969. Sandy dolomite bedrock was
encountered at 51 feet and the water table at 229
feet below the land surface. The six-inch well was
drilled by the air rotary method to a depth of 350
feet, and cased to a depth of 185 feet. Ground-
water samples for chemical analysis were obtained
by bailing or with a submersible pump.
-2 5'
-6"STEEL-
CASING
-59'
-16'
-28 5'
-2.5'
-105'
-205'
I— DEPTH OF LYSIMETER
BELO* REFUSE
Fig. 6. Cross section of the 1962 cell lysimeter network.
Soil Sampling Methods
Samples for soil chemical analysis were
augered from 3 holes beneath the 1967 cell. Holes
SL-3 and SL-6 (Figure 4) were augered 5 feet apart
in November 1967, before refuse emplacement.
Hole SL-13 (Figure 4) was drive cored between
these holes to a depth of 9 feet, 2 years after burial
of the refuse. Drive cores for soil chemical analysis
were also collected in October 1969 from holes SL-
10 and SL-12, spaced 52 feet apart along the 1962
landfill trench (Figure 6).
WATER AND SOIL CHEMICAL ANALYSIS
Water Chemical Analysis
Chemical analyses were performed on soil
moisture samples extracted from the two lysimeter
networks, on leachate bailed from the 1962 cell tap
and 1967 sampling house floor, and on ground-
water samples from the deep well. Lysimeter sam-
ples were collected for analysis approximately
every month. The other sources were sampled less
often. Routine analyses were made in the field
upon sample collection of temperature, pH and Eh
(oxidation potential) or DO (dissolved oxygen).
The pH was measured with a combination pH-
reference electrode and either a Coleman Medallion,
or Sargent-Welch Model PBX pH-millivolt meter.
Eh was measured using a platinum indicator
electrode and saturated KC1 calomel reference
electrode, with either a Beckman Model G, or Orion
Model 407 pH-millivolt meter. Detailed methods of
Eh and pH calibration and measurement are
described elsewhere (Langmuir, 1971a). DO was
measured with a Yellow Springs Model 51 portable
oxygen meter. Other analyses run routinely at Penn
State included a qualitative description of color,
odor, and turbidity, and laboratory analyses of
specific conductance with a Beckman conductivity
bridge, Model RC-1982, and dipping glass con-
ductivity cell (cell constant near 1 cm"1 ), and Cl by
titration with standard AgNO3 solution (Rainwater
and Thatcher, 1960). Total titrable alkalinity (end-
point near pH 4.5) was measured with standard
H2 SO4 within 48 hours on samples which were
refrigerated upon collection and brought to room
temperature just prior to analysis. Samples were
also analyzed approximately monthly within a day
or two of collection for total Fe, BOD (biochemical
oxygen demand), NH.,, and SO4 by the Pennsyl-
vania Department of Environmental Resources
Laboratories in Harrisburg, Pennsylvania. Total Fe
was determined on acidified samples by atomic
absorption spectrometry, BOD by 5-day incubation
of diluted samples, NH, by the nesslerization
method, and SO4 by the turbidimetric method.
Analyses run bimonthly or less often at Penn State
81
-------
included NO3 with a specific ion electrode
(Langmuir and Jacobson, 1970), and Na, K, and Mg
by atomic absorption spectrometry on field acidi-
fied samples. Occasional analyses run by the De-
partment of Environmental Resources included
NO2 (sulfanilic acid method), NO3 (phenoldisul-
fonic acid method), and PO4 (stannous chloride
method). All analytical techniques employed by
the Department of Environmental Resources are
described in Standard Methods (1971).
Soil Chemical Analysis
Soil pH, cation exchange capacity, and ex-
changeable cation analyses were run on soil sam-
ples cored from beneath both the 1962 and 1967
refuse cells during installation of the lysimeter
networks. Soil pH was recorded as the pH of a 1:1
paste of soil and distilled water. Determination of
the exchangeable cations on a soil involves displace-
ment of all adsorbed species with a concentrated
extracting solution and application of a correction
factor for those cations which entered solution
from soluble salts present in the sample. This
correction is particularly difficult \vhen the soil
moisture in the samples is as high and variable in
dissolved solids as landfill leachate. The extracting
solution used in. this study was IN NH4Ac buffered
at pH 7. Correction for soluble salts in contami-
nated samples was made by washing 30 gram soil
samples prior to extraction with either 100 ml of
40% ethanol, or 150 ml of 95% ethanol (Jackson,
1964). The 40% erhanol wash was used to remove
Ca, Mg, and K salts from soil samples. Because this
wash leached most of the exchangeable Na from
the soil, soils to be analyzed for exchangeable Na
were instead washed with the 95% ethanol solution.
Cation exchange capacities were obtained by
summing the exchangeable cations and the ex-
changeable acidity. Exchangeable acidity was deter-
mined by measuring the pH change of a pH 7
calcium acetate-paranitrophenol extracting solution
(Woodruff, 1947).
VARIATIONS IN LEACHATE QUALITY
The Significance of Redox Measurements
in Leachate
Water saturation or isolation of refuse materi-
als can prevent contact between atmospheric oxy-
gen or oxygen-rich fresh recharge and biodegrada-
ble organics in the refuse. Under such conditions
dissolved oxygen in the water and soil moisture is
rapidly depleted by aerobic bacteria, and anaerobic
decomposition then predominates. In the anaerobic
environment iron can exist in its highly soluble and
mobile divalent form. Although only total iron
analyses are available for leachate samples in this
study, previous experience indicates that the iron
is present chiefly as ferrous iron and also in part as
suspended ferric oxyhydroxides (Langmuir, 1969).
Measurements of DO, or Eh when DO values
are less than 0.1 mg/1, and of pH, provide a useful
means of explaining the relative and absolute
amounts of reduced and oxidized species present
in leachate. Eh measurements must be interpreted
with caution when made in waters as chemically
complex as leachate, however. A measured Eh is
the potential at which no net current flows between
the platinum indicator electrode and the reference
electrode. The net current in solution represents
the sum of all anodic and cathodic currents present
during measurement (Langmuir, 197la). Thus, for
example, if both dissolved Fe2 + and Mn2 + are
present along with their higher oxides in sus-
pension, the Eh will represent the sum of positive
and negative currents for both oxidation-reduction
pairs and may thus differ significantly from the
measured Eh in a solution containing only the iron
species. Such an Eh is called a mixed potential. An
additional cause of mixed potentials is the fact
that such reactions as the reduction of SO4 to H2 S,
or NO3 to NH3 among others are too slow to
produce a significant electrode current, whereas
rates of oxidation of H2 S or NH3 are fast enough
to produce such a current. Thus, if relatively large
concentrations of different oxidized and reduced
species are present in a leachate, mixed potential
effects may give a measured Eh which has no
meaning in terms of the theoretical stabilities of the
different species present.
Species which enter into rapid oxidation or
reduction reactions that can thus control an Eh
measurement are called electroactive. The stability
and reproducibility of an Eh measurement depends
not only on the presence of electroactive species,
but also on their concentrations. Such species are
generally absent from oxygenated surface waters
(except iron-rich acid mine waters) or aerobic sub-
surface waters, so that a DO measurement is
usually the best indication of the oxidation state of
such waters.
Redox conditions in landfill leachates which
contain several milligrams per liter BOD or more,
are probably controlled in most cases by the
presence of ferric oxyhydroxide minerals in the
soil, and the activity of anaerobic bacteria. Bacterial
activity leads to partial reduction of the oxyhy-
droxides to Fe2 + . Redox conditions then reflect
equilibrium between Fe2* and remaining solid or
suspended oxyhydroxides as defined by the reversi-
ble and electroactive reaction
Fe(OH)3 + 3H*
= Fe2
3H2O
(1)
82
-------
where Fe(OH)3 denotes the ferric oxyhydroxides.
Because dissolved ferrous iron and suspended or
solid terric oxyhydroxides are abundant and are
the predominant electroaetive species in contact
with most anaerobic landfill leachates, meaningful
Kh measurements should often be possible in such
waters.
The theoretical F.h-pH boundaries for equi-
librium between the important iron and nitrogen
species are shown in Figure 7. The dashed lines
limit the tields of predominance of N()_,, NO, , and
N'Hj species. 1 hese lines show Kh-pH conditions
tor equal concentrations of nitrate and nitrite, and
tor nitrite and ammonia, respectively. The solid
lines in the Figure denote Eh-pH conditions for
equilibrium between suspended or solid ferric oxy-
hydroxides and dissolved ferrous iron at 0.06 mg/1
and 56 mg/1. Also plotted are Eh-pH measurements
on a set of leaehate samples collected July 22,
1969 from beneath the 1967 landfill cell. Two
distinci sample groupings are shown in the Figure.
These include a group of analyses which plot along
Fe;'-Fe(OH), boundaries. Electroaetive constitu-
Fig. 7. Hh-pH diagram at 25JC showing fields of predomi-
nance of NO ,, NO-, and NHJ, and boundaries for equilibri-
um between Fe:* and Fe(OH)3 when Fe2* = 0.06 mg/l and
58 mg/l. A solubility product of 10"37-' for Fe(OH)3 is
assumed. Also plotted are analyses of samples collected
July 22, 1969 from beneath the 1967 cell. Values beside
points are total iron concentrations in milligrams per liter.
Uncontaminatod samples contain BOD < 2 mg/l; contami-
nated BOD > 2 mg/l.
ents including iron species are practical!}' absent in
the first sample group, so that sample Eh values are
only qualitatively meaningful. These samples are
relatively aerobic, and may contain DO in excess ot
0.1 mg/l. Although small amounts ol iron (probably
as suspended ferric oxyhydroxides) are present in 5
ot these 8 samples, the}' are otherwise practically
free of anaerobic species including ammonia, and
contain less than 2 mg/l BOD. Four samples from
the 1967 cell are anaerobic with total iron values
between 80 and 225 nig/1. Because ol their hiiih
Fe'* and ferric oxyhydroxide content this sample
group plots parallel to Fe2"-F'e(OH), boundaries
on the diagram. That measured iron concentrations
are not exactly consistent with the FeJ~- Fc(()11) ,
boundaries in figure 7 (or Figure 8) is to be ex-
pected for these boundaries are based on the activi-
ty ot Fe:* ion, not the total iron concentration.
Also, a particular solubility of l-'e(C)H), is assumed,
whereas its solubility will vary widely (Langmuir
and Whittemore, 1971). The four contaminated
samples in Figure 7 contain a substantial BOD
content. The Figure shows why the aqueous nitro-
gen species likely to occur in anaerobic leachates is
ammonia, and why there is no point in analyzing
waters high in iron for nitrate or nitrite. The
samples plotted in Figure 7 were collected only 7
months after standing water was last observed in
fill materials of the 1967 cell.
Figure 8 is a similar plot of Eh-pH measure-
ments on samples collected a year later (July 22-
23, 1970) from both the 1967 and 1962 cells. At
this time only two of the 1967 cell samples contain
significant total iron, and the iron (and BOD)
values are general!}' less than in samples collected u
year previous. Ten of the twelve samples from the
1967 installation have F.h's above 390 mv. These
samples are nov. aerobic although most contain
substantial amounts of inorganic pollutants. All
samples from beneath the 1962 cell plot along
Fe2*-Fe(OH)., boundaries. In general, these sam-
ples are anaerobic and contaminated by high total
iron, BOD, and ammonia, concentrations. Thus,
Eh-pH measurements provide insights regarding
both the state of renovation of the leaehate, and
the possible presence of particular oxidized and
reduced species.
Time Variations in Leaehate Quality Beneath the
1967 Ceil
Because samples were not collected from the
1962 instrumented cell until April, 1970, the study
of long-term changes in leaehate quality is limited
to such changes beneath the 1967 cell. The quality
of leachates beneath this cell has been greatly
influenced bv the introduction into the refuse of
83
-------
400
300-
Eh
(mv)
200-
IOO-
Fig. 8. Eh-pH diagram showing total iron values in samples
from beneath the 1962 and 1967 refuse cells on July 22-23,
1970. See explanation for Figure 7.
about 8 inches of artificial recharge, and about 6
inches of natural precipitation as rain, between
October 30, 1967, and April 28, 1968 (Lane, 1969).
The artificial recharge was taken from a public
water-supply well of the Pennsylvania State Uni-
versity. This well is also in the Gatesburg Forma-
tion, and its water probably had a composition
similar to that from well UN-17 (see Table 4).
This 14-inch total constituted perhaps more than
double the amount of water which might be ex-
pected to infiltrate this refuse cell naturally during
a similar 6-month period. As a consequence, water
stood in the bottom of the sampling house (Figure
4) from May through December, 1968.
Time plots at four different depths of changes
in specific conductance, Cl, BOD, NH3-N, and total
Fe, are shown in Figures 9-13 respectively. Data
used to construct the plots tor dates before August
1968 are from Lane (1969). The plots show that
leachate moved to the shallowest lysimeters before
flooding of the cell, and almost immediately after
refuse emplacement on October 30, 1967. This
partly reflects compaction during emplacement,
and the high (over 55%) initial water content of the
refuse (Lane and Parizek, 1968), but may also
have been caused by polluted surface runoff which
flooded the open lysimeter holes shortly before
refuse emplacement (Lane, 1969).
84
Fig. 9. Change of specific conductance with time in soil
moisture from 2 and 4 feet depths (SL-3) and 8 and 14.5
feet depths (SL-6) beneath the 1967 cell.
m,/
Fig. 10. Change in chloride concentration with time in soil
moisture from 2 and 4 feet depths (SL-3) and 8 and 14.5
feet depths (SL-6) beneath the 1967 cell.
Fig. 11. Change in BOD with time in soil moisture from 2
and 4 feet depths (SL-3) and Sand 14.5 feet depths (SL-6)
beneath the 1967 cell.
-------
1969 1970
Fig. 12. Change in NH3-N with time in soil moisture from 2
and 4 feet depths (SL-3) and 8 and 14.5 feet depths (SL-6)
beneath the 1967 cell.
Fig. 13. Change in total iron with time in soil moisture from
2 and 4 feet depths (SL-3) and 8 and 14.5 feet depths
(SL-6! beneath the 1967 cell.
The concentration-time plots show that maxi-
mum specific conductance and Cl values arrived
simultaneously at each of the 4 lysimeter depths.
These maxima were 8445 /umhos and 1890 mg/1
respectively, at the 2 feet depth after 4 months, and
1470 jumhos and 375 mg/1 respectively, at the 14.5
feet depth after 31-32 months. Thus, by the time
the leachate reached 14.5 feet, maximum con-
ductance and Cl values had decreased by 83% and
80% respectively. The plots show that maximum
contaminant values are moving downward at the
rate of approximately 6 ft/yr.
Chloride and the majority of other species
(chiefly inorganics) which contribute to the con-
ductance, are readily leached from the refuse into
the subsoil after the refuse has attained field
capacity. Because Cl is practically unaffected by
reactions in the soil, its decrease with depth must
be caused by dispersion and dilution. Dilution is
favored by the design of the 1967 sampling installa-
tion which permits fresh recharge to infiltrate the
soil adjacent to the sampling house where it can
percolate downward and dilute the leachate (Figure
4).
The behavior of redox-sensitive species includ-
ing BOD, total iron, and ammonia (Figures 11-13)
is more complex and less systematic with depth
than that of specific conductance or chloride. This
is partly because conditions in uhsaturated soils
can be both aerobic and anaerobic within a short
distance. Initial conditions in the soil at first
sampling in November 1967 were aerobic as evi-
denced by maximum concentrations of 11 mg/1
NO3-N, 1.0 mg/1 NO,-N, and negligible ammonia
and iron concentrations (Lane, 1969). A BOD value
of 2500 mg/1 arrived at the 2 feet depth after 4
months, and a maximum BOD of 1600 mg/1 at 4
feet after 8-9 months. With the earlier arrival of
leachate containing a few milligrams per liter BOD,
anaerobic conditions were initiated, and bacterial
reduction of nitrate and nitrite to ammonia ensued
by reactions such as
NO; + CH,O + 5H+ + 4e = NH4OH + HCO3
(2)
where CH2 O represents the organic matter in BOD.
Reduction reactions such as (2) raise pH and
probably account for the maximal pH values of 6.5
and 7.5-8.5 observed in the simulated landfill
studies of Quasim and Burchinal (1970), and
Fungaroli and Steiner (1971), respectively. Maxi-
mum pH's between 7.3 and 8.6 were also observed
in this study near the time when conditions in the
soil were changing from aerobic to anaerobic. The
relatively lower pH maximum of Quasim and
Burchinal reflects the absence of soils and other
materials in their purely organic refuse which could
adsorb or otherwise react with H ions.
Although small amounts of ammonia were
formed by reduction of initially present NO3 and
NO2, ammonia has chiefly been produced by the
decomposition of nitrogenous organic substances
in the refuse and leachate. Maximum ammonia
nitrogen values of 100 mg/1 or more arrived at the
2 and 4 feet depths simultaneously with the BOD
maxima. Insufficient sample was available for anal-
ysis from the 2 feet depth after January 1970. The
gradual increase in NH3 -N at 4 feet after October
1968 may be caused by its production from the
breakdown of organic nitrogen in the leachate.
Because leachate which contains nitrate or
nitrite is not sufficiently reduced to contain ferrous
iron from the solution and reduction of ferric oxy-
hydroxides in the soil, the buildup of total iron
(chiefly Fe(II)) by leaching of the soil could not
85
-------
occur until the onset ot more reducing conditions,
As a result, maximum total iron values ot 100 mg/l
or more do not reach the 2 and 4 feet depths until
about 1 month after the arrival ot maximum
ammonia values at these depths. The behavior of
iron and ammonia at S and 14,5 feet depths is less
easily explained, although clearly a major reduction
in these species has occurred with depth. Maximum
total iron values at 2 and 14.5 feet depths were 225
and 5.6nit£''l respectively, and represent a reduction
of 97.5°o. Maximum ammonia values at 2 and 14.5
feet were 54s i ,md 1.8 mg/l— equivalent to a reduc-
tion of more than 99%.
In their studies of synthetic landfills Quasim
and Burchina! {197sii and Fungaroli and Steiner
(197i'» observed maximal iron concentrations at
the lowest observed pH's. A maximum total iron of
850 msi/1 was detected at pH 5.4 in Quasim and
Burchinal's study. 1-ungaroli and Steiner measured
total iron maxima of 1 TOO-1800 mg/l at a pH of
about 5.5. 1-xamination of the data plotted in
Hiiures 7 and 8 shows that in an actual landfill,
total iron concentrations also depend on the oxida-
tion state ot the s\stem, and in fact that maximum
rota! iron values do not occur at the lowest pH's
but .it intermediate values.
Probabl) most of the water entering the refuse
and subsoii before 197u was from the equivalent of
14 inches of rain added to the refuse prior to May,
1968, Hcavv ranis m the spring of 1970 increased
the moisture content of the refuse to well abcwe
field capaciiv for the first time since 1968, and
re-established strongly anaerobic conditions. 1 hat
no increase in specific conductance or chloride
resulted rv.rn this development shows that the
concentrations of soluble inorganic species in the
re ruse had been significantly depleted. However,
ases in BOD, ammonia, and iron during 1970
icleased from the refuse when
Differences Between the 1962 and 1967 Sampling
Installations
Before a useful comparison can be made ot
changes in the 1962 and 1967 cell leachates with
rime "and depth, a discussion of differences in the
two cell installations and settings is necessary.
Features of the 1967 sampling system have proba-
bly accelerated the oxidation and dilution of
leachates in the subsoil with the result that more
leachate renovation is occurring than could be
expected under more typical conditions in the
landfill. As shown in Figure 4, all leachate produced
in the cell percolates through a trench down into
the soil and to the lysimcters below. Oxidation of
leachate is possible in both the trench, which can
receive oxygen through the sampling house, and in
soils beneath the trench which are adjacent to un-
saturated soils under the trench liner. Also, oxygen
in fresh percolation waters can flow through the
inter-trench space next to the sampling shed. This
fresh soil water will also have a diluting effect on
leachate quality. Soil moisture at the lysimeters is
thus a mixture of leachate from the cell and fresh
percolation waters. Also, because of its upslope
position (Figure 2) the 1967 cell is well drained
and cannot intercept appreciable quantities of
leachate from adjacent cells.
In contrast the 1962 cell is emplaced in a
relatively low-lying area where concentration of
precontammated surface runoft from adjacent
slopes frequently occurs, and repeatedly water-
saturates the fill. This increases the volume of
leachate production and isolates the soil trom
fresh sources of oxygen so that anaerobic condi-
tions are established both in the fill and at depth
beneath it. The poor quality and large volume ot
leachate is further aggravated by downslope move-
ment of leachates from adjacent landfill cells along
the cell floors. Downslope movement and concen-
tration of leachate may also follow bedrock sur-
faces beneath the soil which in this case roughly
parallel the topography.
The above conditions have led to relatively
larger amounts of BOD in leachate beneath the
iOOOh
1962
CELL
SAMPLES
4 .
!00
200
500 1000 200C 5000 CCOC
SPEC:F!C CONDUCTANCE Umhos)
Fig. 14. Comparison of the BOD and specific conductance
of leachates from beneath the 1962 and 1967 refuse cells
on July 22-23, 1970. Solid circles denote uncontaminated
samples (< 2 mg/l BOD); open symbols denote contami-
nated samples (> 2 mg/l BOD).
-------
1962 cell than under the 1967 cell. This difference
is evident from Figure 14 which shows the con-
tribution of BOD to the specific conductance of
leachates collected from beneath the two cells on
July 22-23, 1970.
Leachates in Refuse of the 1962 and 1967 Cells
A comparison of the quality of standing water
in refuse from the 1962 cell tap, and standing water
from the floor of the 1967 cell sampling house is
given in Table 2. The data show that soluble
inorganic species have been relative!}' depleted from
the 1962-dated refuse during the 8 years since its
burial. Thus, Na, K, Ca, and Cl concentrations were
89 to 66% lower in waters standing in the 1962
refuse than in waters within the 1967 refuse at the
times of sampling. This reduction in soluble in-
organic species has not been accompanied by a drop
in BOD values which are practically equal in the
two leachates.
Leachate Quality Versus Depth Under the 1962
and 1967 Cells
Plots of the chemical quality of leachates
beneath the two cells on July 22-23, 1970 are
shown in Figures 1 5-20. Also shown in each Figure
is a schematic profile with the general slope-
settings of the two cells. Specific conductance and
chloride profiles beneath both cells display the
same general trends. However, because chloride is
Table 2. Comparison of the Quality of Leachates Standing
in Refuse in the 1962 and 1967 Cells (The 1967 cell pit
bottom sample analysis is from Lane (1969). Specific
conductance (jj) is in micromhos at 25 C, Other analyses
are in milligrams per liter unless otherwise noted)
T (° C)
Eh (mv)
pH
Cl
S04
N03-N
N02-N
NH3-N
Alkalinity as HCO3
(pH 4.5)
P04
BOD
Ca
Mg
Na
K
Total Fe
_
_
_
6,280
657
-
0.0
0. 1 8
60
_
0.8
1,820
1,040
_
350
160
128
15.1
+ 82
6.49
2,290
225
50
0.0
—
18
502
0.0
1,880
186
37
39
51
578
among the species most readily leached through the
soil, chloride values exaggerate trends shown by the
conductance. The Figures show that concentrations
of chloride and total ionic species (as conductance)
released from the 1967 refuse have just begun to
drop, but have been decreasing for several years
under the 1962 cell. The leachate front beneath the
1962 refuse has moved about 50 feet in 8 years, or
at an average rate of 6 ft/yr. Under the 1967
installation the leachate front is moving at an aver-
age rate of 11 ft/yr, and has reached about the 30
feet depth after 2 years and 9 months. This may be
compared to the 6 ft/yr vertical movement rate of
maximum conductance and chloride values under
the 1967 cell. In the absence of long-term records
for the 1962 cell it is not possible to examine the
effects of dilution or dispersion on conductance
and Cl values with depth. Data already described
indicates that such processes have produced a
significant reduction in conductance and Cl values
with depth beneath the 1967 cell.
Fig. 15. Specific conductance in leachates beneath the 1962
and 1967 cells, July 22-23, 1970.
I0 fOO
CHLORIDEimq/^l
Fig. 16. Chloride concentrations in leachate beneath the
1962 and 1967 cells, July 22-23, 1970.
87
-------
!OO iOOO
BOD tmgft}
BOO
Fig. 17. BOD concentrations in leachate beneath the 1962
and 1967 cells, July 22-23, 1970.
Fig. 18. The Eh of leachate beneath the 1962 and 1967
cells, July 22-23, 1970.
Fig. 19. NH3-N in leachate beneath the 1962 and 1967
cells, July 22-23, 1970.
BOD concentrations beneath the 1962 trench
(Figure 17) roughly parallel conductance values and
show that largely anaerobic conditions exist to
depths near 50 feet. This is because most infil-
trating water in the vicinity of this cell has been
contaminated by contact with refuse. As yet no
obvious reduction in the BOD released from the
refuse is apparent. However, the most anaerobic
leachate is not directly under the cell but at a
depth of 10-15 feet based on the occurrence at this
depth of minimum Eh (Figure 18) and maximum
NHj-N (Figure 19) and total Fe values (Figure 20).
The presence of relatively more aerobic leachates
above 10-15 feet indicates that significant depletion
of biodegradable organic materials in the 1962-
dated refuse is occurring.
Fig. 20. Total iron in leachate beneath the 1962 and 1967
cells. July 22-23,1970.
BOD values issuing from the 1967 refuse cell
have not yet significantly decreased. Because of
relatively oxidizing conditions under this cell,
BOD's become oxidized and depleted 10-15 feet
above the deepest penetration of the leachate. The
lowest Eh's are directly beneath the 1967 cell
refuse. At greater depths conditions become more
oxidizing. A lowering in the capacity ot the 1967
refuse to release reduced species has not yet oc-
curred. This is further evident from the plots of
NHj-N and total Fe which showr maxima for these
species directly below the 1967 cell.
The occurrence of the ammonia maximum at
8 feet and iron maximum at 12 feet below the 1962
site is consistent with the Eh drop over this depth
interval. Iron values in excess of 10 mg/1 and Eh's
less than 200 mv are present to depths of 45 feet
below the 1962 cell. Under these conditions am-
monia is the stable nitrogen species and in fact no
nitrate or nitrite has been detected at these depths.
However, Figure 19 shows a rapid decrease in am-
monia below 25 feet. Explanation for this decrease
may be retardation of the ammonia caused by
88
-------
bacterial assimilation, or ammonia adsorption by
clays in the subsoil. The decrease in iron with depth
may also in part reflect cation exchange on clays,
but probably is caused chiefly by oxidation of the
leachate with depth.
Under the 1967 cell, ammonia concentrations
are present at greater depths than are total iron
values. The absence of nitrate or nitrite beneath
this cell indicates that elimination of the ammonia
is also either by bacterial assimilation or cation
exchange. The rapid increase in Eh and drop in iron
under this cell is most consistent with removal of
the iron by oxidation to ferric oxyhydroxides.
ION EXCHANGE ON SOILS BENEATH
THE LANDFILL
Soils beneath the State College Regional Sani-
tary Landfill have clay contents ranging from 2 to
41% by weight (Lane, 1969). The ability of these
soils to renovate or alter leachate quality in large
part depends on their ion exchange behavior, which
in turn depends on the mineralogy of the clay-sized
soil fraction. In Gatesburg-type soils this is chiefly
kaolinite (75-80%), illite (5-10%), montmorillonite
(5%), vermiculite (0-5%), and chlorite (0-5%) (Lane,
1969), and ferric oxyhydroxides which comprise
from about 0.2 to 1.0% of the total soil weight
(Matelski et al., 1963).
The role of cation exchange in leachate inter-
action with uncontaminated soils depends on dif-
ferences in the absolute and relative concentrations
of cations in the leachate and in uncontaminated
soil moisture. A comparison of typical cation con-
centrations in soil moisture before and after con-
tamination is given in Table 3.
Chemical analyses were made of uncontam-
inated soils in cores SL-3 and SL-6 taken at depths
from 3 to 15-17 feet beneath the 1967 refuse cell
(Figure 5). The analyses showed pH values to in-
crease with depth from about 4.7 to 5.7. The
concentration of total exchangeable bases ranged
from 0.7 to 1.6 meq/100 g of soil; the cation
exchange capacity from 1.7 to 5.0 meq/100 g of
soil. The order of adsorption of cations was gener-
ally H ?> Ca =» Mg > Na > K at all depths. With the
Table 3. Quality of Soil Moisture Collected
from Suction Lysimeters Beneath the Landfill
(Concentrations are in milli-equivalents per liter)
Cation
Contaminated, Contaminated,
beneath beneath
Uncontaminated 1967 cell 1962 cell
Ca
Mg
Na
K
0.6 -1.0
0.5 -1.0
0.05-0.2
0.05-0.2
0.2- 3
0.2-10
10 -40
5 -10
10 -25
7 -20
4 -10
0.1- 2.5
exception of H ions, this is the same general order
of cation concentrations in uncontaminated soil
moisture.
Cation concentrations in contaminated soil
moisture under the 1967 cell are in the decreasing
order Na > K > Mg > Ca, and leachate pH's gener-
ally range from 6.1 to 7.1. The order of adsorbed
cations on soils from leachate-contaminated core
SL-13, at depths from 2-7 feet was generally H >
Na > Ca > Mg > K, with soil pH values decreasing
with depth from 7.2 to 4.6. Total exchangeable
bases ranged from 1.3 to 2.8 meq/100 g; the cation
exchange capacity from 1.7 to 4.2 meq/100 g.
Significantly, the adsorbed Na content increased
from about 0.2 meq/100 g in uncontaminated soil
to 0.6-0.8 meq/100 g in leachate-affected soil. The
Na fraction of total exchangeable bases increased
from 12-24% in uncontaminated soil to 29-46% in
contaminated soil.
High soil pH's (8.2) and high Ca content (2.5
meq/100 g) of soils directly beneath the 1967 cell
were evidently caused by the complete solution of
the overlying concrete floor of the sampling shed
by leachate. This resulted in precipitation of CaCO3
in soil above the 2 feet depth as evidenced by soil
effervescence in HC1, and calculated saturation of
soil moisture with respect of CaCO3 (calcite). A
further effect has been reduction of Ca values in
the leachate which has increased the relative pre-
dominance of Na in the leachate resulting in higher
Na adsorption by the soil.
Because refuse in the 1962 cell has been
relatively depleted in the most soluble inorganic
species after 8 years of leaching, the order of cation
concentrations in leachate under the cell was Ca
* Mg > Na > K. The pH of leachates ranged from
5.1 to 6.5. The order of adsorbed cations on
contaminated soils from cores SL-10 (4-42 feet)
and SL-12 (4-56 feet) was generally H > Ca *> Mg
> Na > K, with soil pH values from 4.8 to 6.7.
Total exchangeable bases ranged from 1.0 to 2.9
meq/100 g, the cation exchange capacity from 1.2
to 4.8 meq/100 g.
Unfortunately, exchangeable base measure-
ments were not made of adsorbed ammonia and
ferrous iron, although these species may be as
important as the species measured on some clays
contaminated by landfill leachate (Toth and Ott,
1970).
Probably the most significant result of the
cation exchange study was the observation that the
percent base saturation at a given pH is significantly
higher in leachate-contaminated soils than in uncon-
taminated soils (Figure 21). This could be expected
in that the amount of exchange depends on the
concentrations of metal cations relative to H ion
89
-------
7O(-
co G.O'
r
UNCONTAMINATED
SAMPLES
5.5
S.Or-
CONTAMINATED
SAMPLES
0 20 "SO 60 80 120
PERCENT BASE SATURATION
Fig. 21. The percent base saturation of leachate-contami-
nated, and uncontaminated soils beneath the landfill.
concentrations, and the former are more concen-
trated in leachate than in uncontaminated soil
moisture at comparable pH's.
The pattern of Cl and SO4 concentrations
below the 1962 cell suggests that SO4 is being
removed from the leachate with depth. Thus, at the
2 feet depth, SO4 and Cl values are about 2 and 3
meq/1 respectively, whereas SO4 decreases system-
atically to about 0.5 meq/1 and Cl increases to 7
meq/1 at a depth of 36 feet beneath the cell. Re-
moval of SO4 is probably not by bacterial reduc-
tion in that redox conditions are not sufficiently
anaerobic, but may be caused by anion exchange
on clays. Kaolinite has an exchange capacity of
about 6 meq/100 g for SO4 at pH 6 (Wiklander,
1964). Therefore a soil with 20-30% kaolinite
would have an adsorption capacity for SO4 of 1.2-
2.0 meq/100 g. Sulfate might be adsorbed at
approximately this concentration when anions such
as PO4 which are more preferentially adsorbed than
SO4 are not present in the leachate. However,
clogging of exchange sites by organic anions, and
by ferric and manganese oxyhydroxides probably
reduces the number of sites available for sulfate
exchange.
PHOSPHORUS VARIATION IN SOILS
BENEATH THE LANDFILL
In uncontaminated soils, phosphorus is ad-
sorbed on clays and present as calcium, magnesium,
ferric and aluminum phosphates. Phosphate con-
centrations in the leachate were consistently below
the limits of detection (0.05 mg/1 at PO4 ). Ex-
tractable phosphorus was determined in soil sam-
ples collected from beneath the 1962 and 1967
refuse cells with a solution of 0.025 N HC1 and
0.03 N NH4F (Bray and Kurtz. 1945). This method
removes P in exchangeable positions on clay,
readily acid-soluble forms of P (chiefly Ca phos-
phates), and a portion of the iron and aluminum
phosphates. As shown in Figure 22, at each depth
more extractable phosphorus was present before
than after leachate had percolated through the soil.
The reduction in extractable phosphorus is proba-
bly caused by its precipitation as relatively insolu-
ble ferric iron and aluminum phosphates.
SO .75 0 25 .50 75
EXTRACTABLE PHOSPHORUS(pemi
Fig. 22. The extractable phosphorus content of soils be-
neath the 1962 and 1967 cells. Solid lines denote leachate
contaminated soils; dashed lines denote uncontaminated
soils.
GROUND-WATER POLLUTION BY LEACHATE
Ground-water movement in ca";>on.iu tuT.uics
typically occurs along fractures, iomts, fault planes
and other permeable zones often enlarged by solu-
tion of the rock. The Upper Sandy Member of the
Gatesburg Formation is an interbedded sequence
of carbonate-cemented quartz sandstones and dolo-
mites which has a greater average primary permea-
bility than other more pure dolomite aquifers in
the study area. Because of this high relative perme-
ability, a water table map of the area surrounding
the landfill site (Figure 23) shows a ground-water
trough in the Upper Sandy Member. The trough
90
-------
coincides with a topographic high, as the quartz in
the Upper Sandy Member causes it to be more
resistant to erosion than more pure adjacent car-
bonate rocks. Water table contours in Figure 23
show that the direction of ground-water flow
beneath the landfill is probably northwest into the
ground-water trough. The exact direction of
ground-water flow may not be at right angles to the
water level contours in that permeabilities in car-
bonate rocks are highly anisotrophic (Davis and
DeWiest, 1966).
STATE COLLEGE
REGIONAL SANITARY
LANDFi Ll
Fig. 23. Water table elevation in feet above mean sea level
in the vicinity of the State College Regional Sanitary
Landfill, June 3-7, 1971.
A deep water table well was drilled on a
fracture trace in November, 1969, in the center of
the landfill property (Figure 2). Fracture traces are
natural linear features mappable on aerial photo-
graphs which represent the surface expressions of
near-vertical fracture zones along which permeabili-
ty is usually much higher than in the surrounding
rock (Lattman and Parizek, 1964V Water from
such a permeable zone should be more representa-
tive of the local ground-water depth and quality
than water obtained from tighter interfracture
trace areas.
During the first year of observation, ground-
water levels in this well (Figure 24) showed gradual
seasonal trends independent of individual precipita-
tion events. In this respect the well was typical of
other wells located on Gatesburg Ridge along this
Fig. 24. Fluctuations in the ground-water leve! in the deep
well, and precipitation recorded at the State College
Regional Sanitary Landfill from November, 1969 to June,
1971.
section of the valley (Giddini>s, 1971). Thus, tin-
gradual rise in water level beginning in March.
1970 presumably corresponds to ^round-uater re-
charge which entered the subsurface in the fall of
1969 or of a previous year.
Since early November. 1970, however, a sharp
continuous rise of the water table has occurred in
response to heavy rains. This shift in recharge
characteristics may have been caused by the wash-
ing away of a fine-grained detrital plus which had
partially sealed a sinkhole immediately upvalley
from most of the landfill area ("sink area" in Hgure
2). This now enables runoff from Park Forest
Village, a housing development 500 teet southwest
of the landfill property, ro move rapidly into the
subsurface at this point. The specific conductance
of storm runoff from Park Forest Village alonti this
gulley ranged from less than 100 mnho1- dunn«
summer thunderstorms in 1970 to nearly 600
jumhos following the November 1 5th rainfall. Al-
though some contamination in the present landfill
well water ma}' be from this source, such recharge
could be preventing severe contamination oS the
ground water by landfill leachate.
Another possible source of pollution in the
well water is a sewage oxidation lagoon about 1000
feet from the well (Figure 2) which operated trom
1967 to 1969, and serviced about 1000 people.
The quality of water from the landfill well is
given in Table 4. With specific conductances be-
tween 800 and 995 micromhos, and a DO content
of 2.3 mg/1 or less, measured in 1970, this ground
water was more polluted than any other pumped
from nearly 200 wells in carbonate rocks within
ten miles of the landfill site (Langmuir, 1971b).
Conductances of waters from 4 other wells which
-------
Table 4. Background Ground-Water Quality in the Upper Sandy Member of the Gatesburg Formation (Well UN-17),
and the Quality of Ground Water from the Well at the Landfill Site (Specific conductance (id) is in micromhos
at 25°C. Other analyses are in milligrams per liter unless otherwise indicated)
Collection date:
Appearance & odor:
T(°C)
DO (% sat'n)
Eh (mv)
PH
M
BOD
Cl
SO4
Alkalinity as HCO3
(pH 4.5)
NO3-N
NH3-N
Fe (total)
Ca
Mg
Na
K
L'.V-; 7
8-27-70
clear,
odorless
9.5
93
8.04
215
1.7
8
128
1.5
22
15
0.5
0.7
4-23-70
clear.
odorless
995
41
300
1.8
13
92
22
4.0
LANDFILL
4-30-70 5-27-70 8-13-70
slight
clear, clear, turbidity,
odorless odorless odorless
10.0
21
6.89
860 800 890
1.1
23 41
17 22
278 450 485
2.2 1.5
0.4
14
84
46
9.7
WELL
9-23-70
slight
turbidity.
odorless
9.3
268
6.53
913
0.8
32
30
449
0.9
0.5
0.7
12-31-70 5-29-71
clear, musty
clear, leachate
odorless odor
10.0
< 1
46
7.50 7.31
810 950
7.5
26 50
42
520 463
0.8
0.8
2.1
also tap the Upper Sandy Member range from 182
to 345 jumbos. The closest of these wells has the
best quality water and is about % mile from the
landfill. A comparison of the quality of water from
the landfill well with that from an uncontaminated
well (UN-17) in the Upper Sandy Member repre-
senting background quality, is presented in Table 4.
The Table also shows that gradual deterioration of
the quality of water in the landfill well is occurring
with time. The analysis in May 1971 shows the
ground water to be anaerobic and to contain sig-
nificant amounts of BOD, total iron, and ammonia.
Other contaminant species present in abnormal
amounts are Cl, SO4 , and HCO3. This latest deteri-
oration in quality is evidently caused by mixing
with leachate from the landfill.
Results of a 21-hour pump test of the 6-inch
diameter landfill well at 10 gpm on May 28-29,
1971 indicate that the transmissivity of the under-
lying formation is about 4500 gpd/ft. This is
consistent with transmissivities for the Upper Sandy
Member measured by Siddiqui (1969) of 260-620
gpd/ft in 2 nonfracture trace wells, 370-68,400
gpd/ft in 10 wells on single fracture traces, and
2310-423,000 gpd/ft in 11 wells on fracture trace
intersections. These data demonstrate the extreme
anisotropy of flows in carbonate bedrock and the
difficulty of predicting ground-water flow volumes
through a given rock section.
92
The residual soils at the landfill site are too
heterogeneous to permit meaningful physical calcu-
lations of rates of leachate flow through them
under saturated conditions. The best method of
following leachate progress through the soil is from
the chemical data which indicate that the leachate
front is moving downward at 6-11 ft/yr, but has
not reached bedrock beneath the two lysimeter
networks.
Because ground water under the landfill has
evidently become polluted by leachates from the
buried refuse, channelling of leachate down frac-
tures in shallow bedrock must be occurring.
Leachate may also reach the ground-water table
when contaminated landfill runoff infiltrates the
sandy stream bottom or enters sinkholes in the sink
area (Figure 2) at times of heavy storms.
CONCLUSIONS AND RECOMMENDATIONS
Results of this and previous studies support
the following generalizations and suggestions:
1. In a landfill in unsaturated soils, topography
will be the chief control on the amount and charac-
ter of moisture entering the refuse. Refuse cells on
hill slopes will generally receive less infiltration and
less precontaminated moisture from adjacent cells,
so that their leachates will have lower BOD, iron
and ammonia concentrations than leachates from
cells located near valley bottoms. Cells near valley
-------
bottoms are likely to produce highly contaminated
anaerobic leachate which is not effectively reno-
vated during movement through 40 or more feet of
soil.
2. Marked decreases in the amounts of leach-
ate contaminants can occur with movement of the
leachate in unsaturated soils on hill slopes. In study
area subsoils the decrease in Cl and a similar reduc-
tion in other species is caused by dilution and dis-
persion. The PO4 decrease results chiefly from its
precipitation as ferric and aluminum phosphates.
Oxidation causes a reduction in BOD and ferrous
iron. Ion exchange on soil colloids decreases SO4
and metal cation values generally. The reduction in
ammonia with depth is also caused by cation ex-
change, or by bacterial assimilation. Physical filtra-
tion by soil removes bacteria, ferric oxyhydroxides,
and other suspended substances from the leachate.
3. Inorganic salts progressively decrease in
concentration in leachate as they are depleted in
the refuse. However, BOD and associated reduced
species including ferrous iron and ammonia, fluctu-
ate in amount in leachate with changes in the water
content and temperature of the refuse.
4. Eh measurements in leachate are often
meaningful, for leachate is typically poised by the
presence of abundant ferrous iron and suspended
or soil ferric oxyhydroxides. Along with pH, such
measurements are useful in predicting the presence
and mobility of redox sensitive species in the
leachate.
5. In unsaturated soils leachate quality can be
improved if undisturbed strips of soil several feet
wide are left between landfill cells so that fresh
recharge can enter the subsurface and dilute and
oxidize the leachate.
6. Improvement in leachate quality will also
occur if concrete demolition wastes are placed in
the bottom of landfill trenches. These lime-rich
wastes tend to raise leachate pH and precipitate
leachate Ca as CaCO,. The pH increase leads to an
increased base exchange capacity of the soil and
thus to increased adsorption by the soil of remain-
ing cations in the leachate.
7. This study and that of Hughes et al. (1971)
indicates that location of landfills above the water
table in permeable soils and rock may result in
more serious ground-water pollution than deposi-
tion of the same wastes in an impervious zone be-
low the water table.
8. Finally, location of sanitary landfills in car-
bonate terranes above or below the water table is
likely to cause ground-water pollution. Such pollu-
tion can be minimized by proper landfill design, or
by provision for collection and treatment of the
leachate.
ACKNOWLEDGEMENT
Construction of the leachate collection and
sampling installation in the 1967 dated refuse cell,
and sampling of leachates from this cell prior to
August, 1968, was under the direction of B. E. Lane
and R. R. Parizek. Leachate sampling and partial
analysis was conducted by E. T. Shuster between
July, 1968, and January, 1969. E. T. Shuster also
played a key roie in the field work after this last
date. Dr. Parizek assisted in contracting and design-
ing the water table well, and the leachate sampling
network under the 1962-dated cell, and in coordi-
nating the research. Some of the chemical analyses
were performed by the Pennsylvania Department
of Environmental Resources. Thanks are also due
to Dr. Dale Baker of the Penn State Agronomy
Department for advice on the soil-chemistry phase
of this study. The research also benefitted from
assistance and suggestions offered by graduate
students Roger Jacobson, Todd Giddings, Leonard
Konikow, Darrel Leap, Donald Whittemore, and
William Sanner. The program of research of which
this is a part, has been funded since 1966 by the
Mineral Conservation Section of the Pennsylvania
State University, jointly since 1967 with the
Pennsylvania Department of Environmental Re-
sources.
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Eng. Res. Lab. Rept. 66-7, Univ. of Calif., Berkeley,
120.
Merz, R. C. and R. Stone. 1962. Landfill settlement rates.
Public Works, v. 93 (9), pp. 103-106, 210, 212.
Merz, R. C. and R. Stone. 1966. Sanitary landfill behavior
in an aerobic environment. Public Works, v. 97 (1),
pp. 67-70.
New York State Department of Health. 1969. Sanitary
landfill: planning design and operation. Albany, New
York, 40 pp.
Parizek, R. R., and B. E. Lane. 1970. Soil-water sampling
using pan and deep pressure-vacuum Sysimeters. Jour.
Hydrol. v. 11, pp. 1-21.
Quasim. S. R., and J. C. Burchinal. 1970. Leaching of
pollutants from refuse beds. Jour. San, Eng. Div., Am.
Soc. Civil Eng. v. 42, pp. 371-379.
Rainwater, F. H., and L. L. Thatcher. 1960. Methods for
collection and analysis of water samples. U. S. Geol.
Survey Water-Supply Paper 1454, p. 141.
Remson, L, A. A. Fungaroli, and A. W. Lawrence. 1968.
Water movement in an unsaturated sanitary landfill.
Jour. San. Eng., Proc. American Soc. Civil Engineers.
v. 94, no. SA2, pp. 307-317.
Siddiqui, S. H. 1969. Hydrogeologic factors influencing
well yields and aquifer hydraulic properties of folded
and faulted carbonate rocks in central Pennsylvania.
Ph. D. Thesis, Department of Geology-Geophysics,
The Pennsylvania State University, 502 pp.
Standard Methods for the Examination of Water and
Wastewater. 1971. 13th ed., American Public Health
Assoc. New York, New York, 874 pp.
Toth, S. J., and A. Ott. 1970. Characterization of bottom
sediments: cation exchange capacity and exchange-
able cation status. Environ. Sci. and Technol. v. 14,
pp. 935-939.
Woodruff, C. M. 1947. Determination of the exchangeable
hydrogen and lime requirement of the soil by means
of the glass electrode and a buffer solution. Soil Sci.
Soc. Am. Proc. v. 12, pp. 141-142.
Wiklander, L. 1964. Cation and anion exchange phenomena.
in Chemistry of the Soil. F. E. Bear, ed.; Am. Chem.
Soc. Monograph Series No. 160, Reinhold, New York,
pp. 163-205.
DISCUSSION
The following questions were answered by Michael
Apgar or Dr. Donald Langmuir, after delivering
their talk entitled "Ground-Water Pollution Poten-
tial of a Landfill Above the Water Table."
Q. Hon' did von measure the free v
the refuse cell?
table hi
A. (Apgar) We had a sump drilled into the refuse
of the 1967-dated cell that didn't go through the
floor of the cell. The water level within this cell
was generally 2-5 feet above the floor of the cell
depending on the season, so that some of the
refuse material was always saturated. The ground-
water table was encountered 230 feet beneath the
valley bottom.
94
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Q. // the leackate could be collected, what treat-
ment process would you recommend for it?
A. (Apgar) It would have.ro go through some kind
of oxidation procedure. Some of the objectionable
constituents including high BOD's, high iron, and
high ammonia values can be removed by raising pH
and dissolved oxygen levels. There's a landfill in
southeastern Pennsylvania that has a permit to
operate because they agreed to collect and treat
their leachate. In some cases one should be able to
collect leachate and dispose of it in a municipal
sewer system. Dissolved solids and BOD contents
are much higher in leachate than in sewage, but
leachate would generally constitute a small fraction
of the total volume of waste water entering a
sewage treatment plant.
Q. H/'-y not use COD rather than BOD measure-
ments to indicate the extent of organic pollution';'
Do you co:::
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and from the university, are from a local television
tube manufacturer. Possibly wastes from this latter
source are contributing the rare earths.
Q. When it rains and surface runoff flows in the
valley bottom, is the quality of this runoff affected
by the landfill?
A. (Apgar) Yes, as a matter of fact storm runoff
from the landfill includes water which has been in
contact with the refuse. As the runoff in the stream
channel flows through the site during wet weather,
its quality progressively worsens. Some contamina-
tion of water in the deep well may be occurring by
movement of the runoff into sinkholes, although
the runoff is less contaminated than ground water
from the well.
Q. You say the deep well is contaminated by the
landfill only. Can you exclude possible contamina-
tion by the housing development nearby?
A. (Apgar) We didn't want to overcomplicate the
picture during this presentation. We have been
limited by budget restrictions to drilling one well.
Obviously it is impossible to know anything about
the horizontal movement of contaminated ground
water when you only have one hole in the ground.
Yes, there is a housing development 2000 feet
away, and a sewage lagoon about 1500 feet from
the well failed in 1969, although the lagoon hasn't
operated since then. Based on water levels in other
wells in the area at least a quarter or half mile from
the landfill well, the general direction of ground-
water flow is probably not from the area of the
lagoon toward the landfill well. Also, the well water
is continuing to deteriorate in quality. We consider
this as further evidence that pollution of the well is
by landfill leachate and not sewage from the lagoon.
It would certainly be most useful if we could
obtain support to drill two or preferably three more
wells close to the landfill so as to more exactly
establish the character and direction of ground-
water flow and extent of leachate contamination of
ground water.
Q. Are your suction samplers similar to those
devised by Cole? If not, how do they differ? Also,
is there evidence of differential filtration through
the porous ceramic cup of the lysimeter?
A. (Apgar) The lysimeters we used were obtained
from the Soil Moisture Equipment Corporation in
Santa Barbara, California. I don't know if they are
similar to equipment used by Cole. We consider
samples collected in the lysimeters representative
of the quality of the moisture on the outside. We
are dealing with levels of contamination that are so
highly different from the quality of the original soil
moisture, that whether or not the sampling devices
exclude or absorb small amounts of material is not
going to make much difference. Naturally, we
cannot examine contamination by bacteria or other
suspended material in the leachate because these
materials are likely to be filtered out by the
porous cup. However, such materials would likely
be filtered out by the soil anyway.
Q. Can you give any information on the probable
behavior of microbial contaminants and viruses in
the leachate?
A. (Apgar) I can't do that with confidence be-
cause, as I just mentioned, such suspended materials
are probably filtered out in sampling. We did look
for total coliform bacteria in selected leachate
samples from the lysimeters, but the tests all proved
negative.
Q. Some of your graphs indicate a marked increase
of pollutants with depth in soils below the refuse.
How far above the ground-water table should the
base of a landfill be to prevent pollution? Could a
standard be set?
A. (Apgar) Such a distance is going to vary from
one site to another. You can't say that 30 feet or
even 230 feet as in this case, will be sufficient to
prevent ground-water contamination by landfill
leachate. The safe distance will depend on the local
climate, topographic and geologic setting, and the
amount and character of soils and of refuse
materials.
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Ground-Water Pollution and Sanitary Landfills-
A Critical Reviewa
by A. E. Zanoni
:b
ABSTRACT
The principal studies concerned with the ground-
water pollution potential from sanitary landfills and dump
grounds have been conducted in California, South Dakota,
Illinois and England. These studies have all demonstrated
that leachates are highly pollutional in characteristics, but
once they pass into the surrounding soil regime, the
attenuation mechanisms of dilution, adsorption and micro-
bial degradation tend to reduce the impact of this loading
on the underground-water supply.
A survey of practice in twenty-one States in the
United States regarding ground-water pollution from land-
fill operation showed that not much new research was
underway; there was much variation in the code and laws
dealing with ground-water pollution-, and suggested dis-
tances from landfill to water wells varied from 50 to 1000
feet.
Finally, based on the literature findings plus the
result of the State survey, a set of recommendations are
offered to minimize ground-water pollution problems
stemming from landfill operations.
INTRODUCTION
Ground water can be polluted in numerous
ways in spite of the protective mantle which nature
has provided. Liquid pollutants can originate, for
example, from waste water stabilization ponds,
sludge lagoons, barnyard runoff, septic tank leach-
ing fields or seepage pits, pit privies and the deep
well disposal of certain industrial wastes or treat-
ment plant effluents. Pollutants can also originate
from the leachates of decomposing solid wastes as
in the case of open dumps, sanitary landfills, solid
waste composting sites, industrial refuse, and treat-
ment plant sludges. In the first case the pollutants
are already dissolved or conveyed by the liquid
stream, whereas in the second case, sufficient water
must pass through the decomposing mass to "leach-
out" the pollutants and convey them to the
ground-water source.
There is no doubt that a large amount of the
solid wastes generated in the coming years, or the
residues and by-products of solid waste treatment
methods presently known or to be developed, will
Presented at rhe National Ground Water Quality
Symposium, Denver, Colorado, August 25-27, 1971.
b Associate Professor of Civil Engineering, Marquette
University, Milwaukee, Wisconsin 53233.
be deposited on the land. Vaughan (1968), in his
interpretation of the preliminary findings of the
National Solid Wastes Survey, stated that the aver-
age amount of solid waste collected in the U. S. is
over 5.3 pounds per person per day, or more than
190 million tons per year. It is predicted that these
values will increase to 8 pounds per person per day
and 340 million tons by the year 1980. The
amount of waste actually generated is considerably
more than noted above, amounting in 1967 to 10
pounds of household, commercial and industrial
wastes for every man, woman and child per day,
totalling over 360 million tons per year. It is fur-
ther .estimated that the current annual expenditure
to handle and dispose of these wastes in this
country is $4.5 billion per year.
This paper is concerned with the ground-water
pollution potential associated with the operation of
dumps, sanitary landfills, and any other practices
of the land disposal of solid wastes. The paper first
includes a critical review of the important literature
covering the area of the ground-water pollution
potential from sanitary landfills and dump grounds.
This is followed by a review of the practices in 21
States in the U. S. related to this same topic. Based
on the information derived from these two sources,
a series of recommendations are suggested to a
"re
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lyzed the data obtained from the National Solid
Wastes Survey on over 6000 land disposal sites.
Using the modest criteria that a sanitary landfill is
one in which there is daily cover of refuse, no open
burning, and no water pollution problem, it was
estimated that only 6 percent of the 6000 can be
reasonably characterized as "sanitary landfills." In
view of the above it was decided for the purposes
of this paper to use the term "sanitary landfill" or
simply "landfill" in the very broadest sense. The
primary concern was simply what effect land dis-
posal of refuse or solid wastes of any kind, either
in the form of a true sanitary landfill or an open
dump, has on the ground-water quality in the
vicinity of the operation.
LITERATURE REVIEW
Major Studies
After examining some of the literature in this
area, it became readily apparent that certain groups
or States had conducted and are still conducting
most of the research. Without doubt since the early
1950*s there has been more activity in the State of
California in this regard than any other State in the
country. One of the first studies was an in depth
investigation on the leaching of soluble salts and
alkalies from incinerator ash dumps (State of Calif.,
1952). Following this study, the City of Riverside
sanitary landfill was used as the site for the in-
vestigating of the leaching properties of a typical
municipal refuse (State of Calif., 1954a; Univ. of
Calif., 1955; Univ. of Calif., 1956). Two often
quoted conclusions from this study regarding the
effects of landfills on ground-water quality are:
1. "A sanitary landfill, if so located that no portion
of it intercepts ground water, will not cause impairment of
the ground water for either domestic or irrigational uses."
2. "A sanitary landfill, if so located as to be in inter-
mittent or continuous contact with ground water, will
cause the ground water in the vicinity of the landfill to
become grossly polluted and unfit for domestic or irriga-
tional uses."
In 1961 another report was written entitled, Effects
of Refuse Dumps on Ground-Water Quality with
the main purpose of collecting all available data on
the extent of pollution of ground water from dump
leachates, and to make recommendations for future
research programs to fill any gaps in knowledge
available (State of Calif., 1961). The report in-
cluded a good literature review of such topics as
vertical water movement, decomposition process,
gas production and movement, leaching, and travel
of pollution. The concern about gas production in
recent years was the impetus for the initiation of
another study entitled, In-situ Investigation of
98
Movements of Gases Produced from Decomposing
Refuse (State of Calif., 1965; State of Calif., 1967:
Bishop, Carter and Ludwig, 1966). This study
proved to be of interest since up to that time most
work had been done on the question of refuse
leachates affecting ground-water supplies, whereas,
practically no work had been done on refuse-
produced gases as potential ground-water pol-
lutants. Merz and coworkers (Merz, 1969) of the
University of Southern California conducted a five
year study on sanitary landfills using four specially
constructed cells at the Spadra Landfill operated by
the Los Angeles County Sanitation District. Finally,
in 1965, the California Legislature directed that a
study be made of water quality problems in the San
Francisco Bay-Delta area including water contami-
nation and pollution resulting from disposal of
solid wastes. This study resulted in the preparation
of a report entitled, A Study of Solid Wastes Dis-
posal and Their Effect on Water Quality in the San
Francisco Bay-Delta Area (Calif. Water Board.
1968). One chapter in the report entitled, "Influ-
ence of Solid Wastes on Water Quality" presents a
short review of some of the literature on leachates
and gas production from disposal sites. Reference
is particularly made to past California studies. In-
cluded also is a rather extensive survey of all land
disposal sites in the Bay-Delta area from the stand-
point of surface and ground-water quality. A water
quality evaluation scheme was worked out and ap-
plied to each disposal site.
Andersen and Dornbush (1967, 1968) of
South Dakota State University have been studying,
over a period of almost ten years, the effects on
ground-water quality of dumping refuse from the
city of Brookings in an abandoned gravel pit lo-
cated 2 miles south of the community. The ground-
water table at the site is about 6!/2 feet below
ground surface and the principal geological feature
of the area is a sandy-gravel outwash covered at the
surface by about a one foot clay and silt alluvium.
The cation exchange capacity of the area was felt
to be very low. The estimated ground-water veloci-
ties are in the range of 1 to 3 feet per day. Through-
out the study period, a total of 45 test wells have
been constructed "upstream" and "downstream"
of the dump area. After some preliminary studies,
they found that chloride, sodium, specific conduct-
ance, and total and calcium hardness were the
inorganic parameters of ground-water quality which
could be used most effectively to denote any
changes attributable to leachates from the disposal
area. On the basis of statistical studies they found
that chloride level is the most sensitive parameter
with wells, for example, in the center of the dis-
posal area experiencing a 50 fold increase in con-
-------
centrations in comparison to the unaffected ground
water. Isoconcentration lines drawn for hardness
and specific conductance demonstrated clearly that
the significant leaching effects of these two param-
eters on ground-water quality remained in the
immediate vicinity of the disposal area. High con-
centrations of these parameters were confined to a
relatively narrow band but extended as far as 1000
feet from the landfill disposal area. The most recent
work at the Brookings site has been directed toward
an evaluation of the effects of constructing a long
trench on the quality of the degraded water flow-
ing from the disposal area. The trench was con-
structed along the downstream edge of the disposal
site. Upon an evaluation of the water quality data
above and below the trench, it was concluded that
the intercepting trench improved the quality of the
degraded ground water flowing from the fill area.
It was felt that this beneficial effect was caused by
the dilution and photosynthetic activity afforded
by the surface water.
A number of studies have also been conducted
in England through the years. One often referred
to study is called, Pollution of Water by Tipped
Refuse (Ministry of Housing and Local Govern.,
1961) in which the leaching properties of a landfill
were compared under "dry" and "wet" conditions.
In the case of the former, the refuse was dumped
under dry conditions and a known amount of water
was applied to the refuse; whereas in the case of the
latter, the refuse was dumped into water. Con-
siderably more pollutional matter was leached from
the refuse under the wet conditions and during a
shorter period of time. The publication also in-
cludes some work on the possibility of setting up a
landfill site to collect all leachates, direct them to a
central point and provide treatment prior to dis-
posal just like any other waste water, and the
possibility of removing stabilized refuse from an
"ideal" site for the reuse of a fresh refuse. More
recently, a symposium was held on "The Effects of
Tipped Domestic Refuse on Ground-Water Quality"
in which the results of four investigators were re-
ported (Water Treatment and Examination, 1969).
None presented evidence of any serious degradation
in ground-water quality resulting from the land
disposal of solid wastes.
Some of the most useful studies in recent
years on landfill site selection and evaluation from
the standpoint of practical applicability of the
information have been conducted by investigators
of the Illinois State Geological Survey. Hughes
(1967), for example, wrote a very helpful publica-
tion on a methodology for evaluating a disposal
site considering the hydrologic environment of the
site and the method of disposal. He stressed that
climatic, hydrologic, and geologic factors strongly
influence the production and spread of contami-
nants from landfill sites, and therefore it is danger-
ous to over-generalize the findings from one area to
another. Cartwright and McComas (1968) con-
ducted earth resistivity and soil temperature sur-
veys around four sanitary landfills in northeastern
Illinois and concluded that.
"Geophysical surveys are not a substitute for hydro-
geologic studies, but can be used with moderate control as
a preliminary tool in the investigation of sanitary landfills,
and can be extremely useful in the location of piezometers
for detail studies."
Bergstrom (1968a, 1968b) discussed the feasibility
of disposing of industrial wastes into deep geo-
logical formations in the State of Illinois. He
(Bergstrom, 1968c) also discussed in general the
disposal of wastes of all types in the ground from
the broad standpoint of waste management. He
stated that instead of viewing waste disposal on
land immediately as a ground-water pollution prob-
lem, many ground-water workers are beginning to
take a more positive role by studying and classify-
ing hydrogeologic environments relative to waste
disposal. Cartwright and Sherman (1969) wrote an
interesting and very useful document entitled Eval-
uating Sanitary Landfill Sites in Illinois in which
they point out, among other things, that limestone
quarries and gravel pits are rarely, if ever, accepta-
ble refuse disposal sites from a hydrogeologic stand-
point, but that sanitary landfills can be located in
relatively impermeable, or slowly permeable, ma-
terial so that movement of refuse leachate will be
retarded. Hughes, Landon and Farvolden (1969)
have reported on a study describing the hydro-
geologic environments in the vicinity of four
existing landfill sites in northeastern Illinois, in
order to determine the controls on the movement
of the ground water and the solids dissolved in the
ground water. The intention was that this informa-
tion can then be used by regulatory agencies to
help determine environments most suitable for
near-surface disposal of waste insofar as contamina-
tion of ground water and surface water is con-
cerned. The report has a great deal of practical
information to aid the reader in this regard.
Remson, Fungaroli and others of the Drexel
Institute of Technology, have been involved in
studies on ground-water pollution potential of
sanitary landfills for several years. Two recent
reports were published containing useful informa-
tion on the design of a laboratory lysimeter for
sanitary landfill investigations, and the design of a
sanitary landfill field experiment installation
(Fungaroli, Steiner and Remson, 1968; Fungaroli,
Steiner, Emrich and Remson, 1968). Though both
99
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of these publications do not contain any actual
operating data and results, they do provide useful
hints for anyone interested in instigating an investi-
gation of this type. In another publication
(Remson, Fungaroli and Lawrence, 1968) the
authors proposed a method of moisture routing
first through the soil cover and then through the
underlying compacted refuse. Their method was
illustrated by its application to a hypothetical
landfill.
A series of papers have been published by
LeGrand (1964a, 1964b, 1965, 1968) of the U. S.
Geological Survey on the general topic of ground-
water contamination from various sources. In these
papers he presents a point evaluation system for
assessing the contamination potential of a waste
disposal site, a very basic and informative discussion
on the management aspects of ground-water con-
tamination, the use of "malenclaves" for estimating
the areal extent of contaminants in the ground, and
a methodology of approaching a ground-water
monitoring program.
Other Studies
In addition to the groups or States which have
been reported above, a number of other studies
have been conducted on the general topic of
ground-water pollution from sanitary landfills.
Qasim and Burchinal (1970a, 1970b) studied the
chemical and pollutional characteristics of leachates
from different heights of refuse columns containing
similar fill materials of approximately the same age,
and operating under similar conditions of percola-
tion and leaching. An interesting conclusion from
their study was the suggestion that deeper fills
pose less of a pollution problem than do the
shallow fills simply because the rate of pollution
production is greater initially in the case of the
latter. Kaufmann (1969a, 1969b) has written a
good review on the topic of hydrogeological aspects
of the disposal of solid wastes on the ground, in
addition to presenting some preliminary findings on
his current investigation on the over-all hydro-
geology of two sanitary landfills in the Madison,
Wisconsin area. Landon (1969), who feels that site
selection for final disposal of solid wastes is one of
today's most critical solid wastes problems, wrote
an interesting paper to show the necessity and
application of hydrogeologic knowledge and con-
cepts to the selection of refuse disposal sites. The
use of resistivity measurements for economically
obtaining hydrogeological information on a poten-
tial landfill site and operating landfill sites appears
to have merit, according to findings of Page (1968)
and Warner (1969). Finally, Hart (1967) reported
briefly on a study which has been going on for
three years at the West Berlin, Germany landfill to
determine the effect of the compaction of refuse
upon the water regime within the fill.
General References
There are a number of references which in-
clude a general discussion of the relationship be-
tween sanitary landfills and ground-water pollution
problems. Most of these sources present brief
summaries of the studies which have already been
presented in this paper, particularly the California
studies. Some are fairly complete and helpful while
others are quite brief and of limited usefulness
regarding the topic at hand. The main point is that
by reviewing several of these sources one can obtain
a general overview on the ground-water pollution-
solid waste disposal relationship.
Cummins (1968) wrote a short review-type
report entitled, Effects of Land Disposal of Solid
Wastes on Water Quality. Most of the important
studies are included in the 15 references cited, but
very little detail on results is included. Golueke
(1968) wrote a 300 page report which includes ab-
stracts and excerpts from the literature on the
broad topic of solid waste management. Because of
the nature of the topic, it is not surprising that
some of the important investigations in the area of
ground-water pollution do not appear in this
publication. Two of the ASCE—Manuals of Engi-
neering Practice (ASCE, 1959; 1961) include a
short discussion on ground-water pollution. The
same is true for the APWA book, Municipal Refuse
Disposal (APWA, 1966). All three of these dis-
cussions draw mainly from the California studies.
Sorg and Hickman (1968) have written a small
semitechnical report for the U. S. Public Health
Service entitled, Sanitary Landfill Facts which
includes some discussion of water pollution prob-
lems. A bibliography is added to the end of the
report. The U. S. Public Health Service has also
made available a number of helpful bibliographies
on the topic of sanitary landfills specifically, and
refuse collection and disposal in general (Steiner
and Kantz, 1968; U. S. Dept. of H.E.W., 1954-
1963). The sanitary landfill bibliography was pre-
pared by Steiner and Kantz of Drexel Institute of
Technology and covers the literature for the period
1925 to 1968. Finally Weaver (1956) and Black
(1965) have briefly discussed the ground-water
pollution problems in some of their writings on
sanitary landfills.
Health and Nuisance Problems
Considering the tremendous amount of solid
wastes which have been deposited on the land,
there are still relatively few recorded instances of
100
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serious ground-water pollution problems linked to
leachates from landfills and dump grounds. No
doubt there have been probably many small
localized nuisance conditions which have never
been reported. There have also been and still are
many cases in which impairment of water quality
has not been detected because there have been no
noticeable deleterious effects traceable to the water
being used. A review of some of the health and
nuisance problems recorded is presented below.
Some of the information on instances reported are
quite detailed and very specific; whereas, many
others are similar to the following statement taken
from a 1953 Joint Study of the HEW Department
and APHA entitled, Refuse Collection and Disposal
for the Small Community (1953): "Landfills should
be so located that seepage from them will not cause
hazards or nuisances."
Forty years ago, Calvert (1932) reported on
the deterioration of a well water caused by the pit
disposal of liquor drained from cooked garbage.
The well water before and after contamination
showed a substantial increase in iron, total hard-
ness, total solids, CO2 and total organic nitrogen.
The University of California (1952) in 1952 con-
ducted field studies on refuse collection and dis-
posal operation in 13 California cities. In the
section on public health problems, no mention
was made of ground-water pollution problems
other than a minor reference that the possibility of
ground-water contamination should be considered
in selecting a site for landfill disposal of refuse.
Publication No. 24 of the California State Water
Pollution Control Board (State of Calif., 1961)
includes several pages on the reported experiences
from the literature on health and nuisance prob-
lems. The ASCE publication Ground Water Basin
Management (ASCE, 1961) makes reference to
potential ground-water pollution problems from
disposal of wastes of any kind on the land. A listing
of typical industrial wastes together with common
characteristics affecting ground water are presented
in the document. Anderson (1964) (APWA, 1963)
has written on the general topic of the public
health aspects of solid waste disposal and includes
potential water pollution problems as one of the
matters of public health concern. Hanks (1967) in
1967 wrote a very detailed and well referenced
report for the Solid Wastes Program of the U.S.P.H.
S. on the Solid Waste-Disease Relationships. Under
the topic of diseases associated with chemical
wastes, several references are cited on the pollution
of ground water from the leachates of sanitary
landfills. A frequently mentioned report on the
subject of ground water is one entitled, Ground
Water Contamination which presents the proceed-
ings of a 1961 symposium (Robert A. Taft San.
Engrg. Center, 1961). In the session dealing with
specific incidents of contamination of ground wa-
ter, Weaver discussed the significance of refuse
disposal in this regard, using to a great extent data
from the California studies of Merz and others.
Chapter five of Sanitary Landfill, (ASCE, 1959), a
publication of ASCE, is entitled "Public Health and
Nuisance Considerations," and includes a section
on water pollution. Walker (1969) recently wrote a
very interesting paper on ground-water pollution in
Illinois, and one of the pollution categories he
considered was that of garbage disposal. He makes
the statement:
"Serious contamination of the ground-water reservoirs
near these dumps (garbage dumps) can readily occur if the
bottom of the depressions is below the water table, or if the
earth material separating the dump from the aquifer is
primarily silt, sand, or other relatively permeable material."
He presented two actual cases of pollution of
ground-water supplies traceable to leachates from
garbage dumps. As part of the City of Santa Clara
demonstration landfill study, Stone and Friedland
(1969) conducted a survey of American cities with
populations greater than 10,000. They received
replies from 120 landfill sites operated by 102
governmental agencies serving a combined popula-
tion of 17,800,000. Ground pollution problems
were reported at 11 of the sites or approximately 9
percent of the total 120 sites. Williams (1969), who
discussed the over-all topic of ground-water pollu-
tion, claimed that;
"Sanitary landfill seepage into sand or an overly deep
excavation for a lagoon so that shallow subsurface water in
the stream alluvium is intercepted, are two of the most
common ways of polluting shallow ground-water supplies."
An interesting case of the contamination of a
ground-water supply by an industrial waste has
been reported (Mpls. Trib., 1968). A large company
in the Minneapolis-St. Paul area dumped isopropyl
ether in a disposal site for several years before it
was realized that the industrial solvent contami-
nated the aquifer. The company had to spend
$600,000 to remedy the situation. Another exam-
ple of how an industrial waste landfill can affect a
public water supply is the case of Kansas City,
Missouri, reported by Hopkins and Popalisky
(1970).
Two additional interesting publications should
be noted at this point, though they are not specif-
ically addressed to the topic of ground-water pollu-
tion from refuse decomposition on the land. One of
the reports entitled Investigation of Travel of
Pollution (State of Calif., 1954b) is concerned with
the artificial recharge of aquifers with sewage treat-
ment plant effluents, and thus the principal item of
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concern is the fate of microorganisms, and organic
and inorganic chemicals as the liquid passes through
the subterranean soil. The report includes a litera-
ture review on the subject. The second report
entitled Status of Knowledge of Ground Water
Contaminants (Stanley and Eliassen, 1961) includes
a very comprehensive literature search including
better than 700 references on the characteristics
and status of knowledge on the various contami-
nants which can be found in ground water. This
report can serve as a valuable reference when
specific information is desired on the effects of a
particular leachate chemical.
DISCUSSION OF THE LITERATURE FINDINGS
After some review of the literature on sanitary
landfills, one point becomes clear almost immedi-
ately; that is, there are very few case histories of
serious or even troublesome contamination of
ground water which are directly attributable to the
leachates from sanitary landfills. To be sure there
may have been many such instances which were
simply not reported. Even more probable, there
may be many unknown cases currently of people
routinely using water impaired in quality somewhat
as the result of the land disposal of solid wastes.
The writer, for example, has not learned of a
single person who has died as the result of ground
water being contaminated by a landfill. Consider-
ing the number of landfills past and present and
the amount and variety of solid wastes generated
in our modern technological society, this is a
remarkable situation. This statement is not made
at the outset of this discussion to belittle the
potential for serious harm to many people through
this mechanism, nor to cast any aspersions on the
fine research which has been and currently is still
being done in this area. But, nonetheless, this point
is most critical when considering recommendations
for future action in this area, since it is this type of
statistic which ultimately motivates action in any
similar activity. For example, the greatest impetus
for improved public water treatment and distribu-
tion works at the turn of the century was no doubt
the 20 to 30 typhoid deaths per 100,000 popula-
tion per annum occurring at that time.
This situation attests to the almost miraculous
capability of most soils to attenuate the leachates
generated from sanitary landfills. From the results
of the literature, there is no question that these
concentrated leachates are of extremely high pollu-
tion strength. There are few industrial waste flows
that would match this material and without doubt
no responsible governmental agency would tolerate
the discharge of a material like this untreated into
a surface body of water. There is an important
difference in the subterranean regime, however. The
soil provides the site for active microbial degrada-
tion of the organics which are present in the
leachates. The inorganics are adsorbed to the soil
surface and many of the more undesirable ions are
exchanged for the more desirable ones. The ex-
tremely low velocity of the underground-water
resource provides the necessary time for these
activities to reach a fair degree of stabilization, thus
confining most of the degradation processes to the
immediate vicinity of the landfill. The soluble end
products are attenuated even further by the sheer
vastness of the underground-water body by the
simple mechanism of dilution. The highly soluble
chloride ion provides a useful tracer for the situa-
tion described above. In most of the research
studies examined, the chloride concentration in the
leachate directly below the landfill was always
extremely high. The chloride concentration
dropped drastically in water samples taken only a
short distance from the landfill operation. At dis-
tances of several hundred feet the concentration
drops down to almost native or background levels.
Unfortunately the described process does not
hold true to the same degree for all geological
formations, and therein lies the crux of the prob-
lem. The above will usually hold true for uncon-
solidated formations consisting of varying propor-
tions of clay, silt, fine sand and loam with low to
medium permeabilities. For unconsolidated materi-
als of coarse sand and gravels with high permeabili-
ties or consolidated materials such as limestone or
shale with fissures, faults or fractures of any kind,
the protective mechanism breaks down because of
one important reason, that is, time. In formations
of the latter type there is much less time available
for the degradation process to take place within
the vicinity of leachate generation because the
underground velocities are much higher. Thus par-
tially "treated" and poorly diluted leachates can
appear at greater distances from the landfill. The
assumption made here is that the ground-water
flow is through and away from the landfill site.
If all the flow lines are directed toward the site
this situation will not necessarily occur and what
probably will happen is that the ground water will
discharge at the surface somewhere nearby. Such a
situation could then have a deleterious effect on
the surface supply.
It is convenient to think of a mass of refuse
stored in a landfill site as representing a certain
mass or quantity of pollutants. Some of the re-
searchers have in fact done just this when they
express specific leachate constituents in terms of
weight per cubic yard or per ton of deposited
refuse. This mass of pollutants will eventually be
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generated from the landfill, since the processes of
weathering and biological degradation always take
place. The important variable again is time. In order
to speed up the degradation and weathering proc-
ess, moisture and favorable temperature are neces-
sary. Usually temperature is not a restricting factor
even in northern latitudes since the interior of the
refuse mass is insulated from the ambient tempera-
ture and the degradation process is exothermic in
character. Available moisture then becomes the
limiting factor. Rapid degradation will occur in a
more loosely packed landfill where surface waters
are permitted to percolate freely through the
refuse. The degradation process can be slowed up
considerably by allowing less surface water to pass
through the fill. It is virtually impossible to abate
completely this activity. Obviously if the degrada-
tion process is retarded by restricting passage of
water in any way, more time will be allowed for
the natural attenuation process to take place be-
yond the landfill site. A combination of retarded
degradation in a geologic formation of ideal attenu-
ation provides the least likelihood of serious
ground-water deterioration. Speeding up the degra-
dation process imposes a greater load on the sur-
rounding geologic formation; and if the geologic
formation is a poor one, the problem is com-
pounded. Again it must be remembered that the
same pollutional mass is involved in both cases.
It is possible to engineer and operate a landfill
operation with the intent of minimizing the
amount of percolation through the deposited
material. Bottom liners of various types, high
degree of refuse compaction, shredding, and highly
impervious earth covers are examples of what can
be done. These measures would, on the other hand,
be highly ineffective in situations where the
moisture sources originate from below the landfill.
There is no question that in areas where wide fluc-
tuations in the ground-water table occur to the
point where the refuse becomes repeatedly satu-
rated with water and then drained, the degradation
process is intensified to probably its optimum level.
If the attenuation capability of the geologic forma-
tion surrounding this site is limited, a situation
again exists for serious pollution of the ground
water.
Some in the field of solid waste disposal argue
that a landfill should be designed for optimum
degradation and weathering to occur. This means
that an ample amount of water should be per-
mitted to percolate through the fill. It also means
that the leachates must then be collected in a drain
system and treated prior to discharge to a surface
water body or possibly back through the fill. After
a reasonable degree of stabilization has occurred
the leachates will no longer be collected in the
drain system but allowed to pass into the surround-
ing soil. In this way they argue that the degradation
process can be controlled as desired and the possi-
bility of future pollution problems is reduced
considerably. Some for example argue that huge
quantities of stored refuse located in the earth
close to large population centers are akin to geo-
logic pollutional "time bombs" which could be
very troublesome to future generations. There is no
doubt that landfill sites can be engineered to speed
up the degradation process and collect and treat the
leachate. However, the economics of this arrange-
ment may favor other disposal methods which,
relative to traditional landfills, were formerly con-
sidered too expensive.
Another point becomes quite apparent after
reviewing the literature in this area. Much more
geologic, or more specifically, hydrogeologic ex-
pertise should be employed prior to the selection
of a landfill site. Someone with training in hydro-
geology7 can establish with a fair degree of accuracy
upon an examination of the site and often with a
limited amount of field testing what the leachate
attenuation potential of a site will be and if the
cover material will permit a slow or rapid percola-
tion of water into the fill. Too many landfill sites
are selected on a purely political, economic or con-
venience basis with no or little attention given the
geology of the site. It is surprising that regulatory
agencies have been somewhat lax in this regard,
also. The writer is convinced that attention to this
matter alone will minimize many future ground-
water pollution problems attributed to landfills.
The major threat to ground-water quality in
the future will likely be from the land disposal of
industrial wastes. Many of these wastes decompose
slowly or are nondegradable, which means the
protective mechanism of attenuation afforded by
the soil is no longer available. Many industrial
wastes can impart odor, taste and even toxic
problems to ground waters at extremely low con-
centrations. With advances in technology7 and the
increase in over-all affluence there will undoubtedly
be an increase in the amount and complexity of
solid industrial wastes produced. Many new com-
pounds will also be synthesized in the future which
can pose either acute or chronic threats to the
health of future users of ground water. The present
trend toward more stringent surface water quality
standards will cause some industries to look toward
land disposal for the solution to their industrial
waste problems. It is important to keep in mind in
this regard that much empirical evidence is availa-
ble to substantiate the generally innocuous effects
to humans resulting from the decomposition of
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ordinary municipal refuse in the ground. On the
other hand, practically each new solid industrial
waste completely nullifies the dependence on this
past evidence as the primary basis for establishing
guidelines to dispose of the new material. For this
reason alone it is imperative that extreme caution
be exercised in the land disposal of all solid indus-
trial wastes in the future.
SURVEY OF STATE PRACTICES
As a means of becoming acquainted with the
numerous problems associated with ground-water
pollution from disposal of solid wastes, it was de-
cided to conduct a survey of the activities and
policies related to this area in 21 of the States in
the U. S. The States selected comprise a total
present population of approximately 140,000,000
which amounts to 70 percent of the U. S. popula-
tion. The basis for selection was somewhat arbi-
trary, but the list was intended to include the
larger States, States in the midwestern part of the
country and States in which it was known that
some activity in this area was taking place. The
States included in the survey were: California,
Florida, Illinois, Indiana, Iowa, Kansas, Maryland,
Massachusetts, Michigan, Minnesota, Missouri, New
Jersey, New York, North Dakota, Ohio, Oklahoma,
Pennsylvania, South Dakota, Texas, Washington
and Wisconsin.
Letters were sent in June, 1969 to the regula-
tory officials in the various States who were known
to be familiar with the solid waste practices within
their particular State. The letters first explained the
reasons for the information requested and specif-
ically solicited comments on the following four
questions:
1. Are you aware of any research activities in
your State that are concerned with ground-water
pollution from sanitary landfill and open dump
type of operation?
2. Does your State have published codes or
guidelines regarding site selection for sanitary land-
fills and dump grounds? Do you have regulations
pertaining to the operation of such areas?
3. Does your State specify a minimum dis-
tance that a water well can be located from a
landfill or dump ground?
4. Do you anticipate that your State will be
engaged in some aspect of this question in the
immediate future, such as writing new or revising
old codes, field research programs, etc.?
Upon an examination of the replies received,
which varied in detail from "ves" and "no" answers
on the original letter mailed to voluminous replies
containing complete laws, codes and research re-
ports, it became readily apparent that there has not
been a great deal of research activity in the area of
ground-water pollution from the land disposal of
solid wastes. A little more than half the States
queried responded that no research activities of this
type were taking place in their own particular
State. Probably the most extensive work in the
past has been confined to three States, namely,
California, Illinois and South Dakota. Most of the
recent work which has been published in this area
has originated from universities and public and
private research agencies within these States. A few
other States are beginning to become a little more
active in this regard. They are Maryland, Pennsyl-
vania, and Wisconsin. Another interesting observa-
tion was that a number of States are beginning to
or are making plans to monitor the ground-water
quality in the vicinity of landfill sites. It is the
writer's opinion that other States will become
involved in this activity in the future.
It was also readily apparent that there is much
variation in the details given to codes and guide-
lines pertaining to the selection of landfill sites,
particularly with reference to the possible ground-
water pollution problems. These range from a few
States which do not have any published codes or
guidelines to others like California where one of the
Water Quality Control Boards recently published a
ten page "Statement of Policy" going into numer-
ous details on classification of wastes and disposal
sites primarily to guard against the pollution of
ground and surface waters. Many of the State regu-
lations merely included broadly worded statements
of the type "Sanitary landfill and other solid waste
disposal activities shall not pollute the ground
waters and surface waters of the State." Of the
States queried, California, Illinois, Maryland, Michi-
gan, Minnesota, New York, Ohio and Wisconsin
have made the most detailed reference to ground-
water pollution potential. On the most part, these
States require as a matter of policy, geological
data, water table elevations and other hydrological
data prior to the approval of landfill sites. Other
States may have local health departments which
require the same information, but it was not
expressed as a matter of State policy. It was also
evident that the States with the most stringent
regulations in this regard were the ones with the
most recently enacted laws.
The policy on landfill to water well distance
employed by the States surveyed appeared for the
most part to be a very tenuous one. Eight States
would not commit themselves to a specific dis-
tance, stating in effect that each case was con-
104
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sidered individually before a specific distance was
set. For the States that gave a value, the distances
varied from 50 to 1000 feet with most of the values
in the 100 to 500 feet range. Some States indicated
that no specific value was used for sanitary land-
fills, and thus they gave the values used for the
location of water wells from any known sources of
contamination. Most of the States which estab-
lished a distance cautioned that the value was only
used as a rough guide and it was by no means a
rigid one. The tenor of the remarks in this regard
was that no one really knows what a "correct"
value is and empirical evidence from the past
indicates that a particular value was used in the
past without any adverse effects. The lack of
ground-water monitoring in the vicinity of landfill
sites is probably the primary reason for this
dilemma.
Very little research activity was being con-
templated in the States surveyed in the immediate
future. As was noted previously, some ground-water
quality monitoring around landfill sites will be
conducted in a few of the States. Most of the
States, however, will be active in the area of rules
and regulations pertaining to solid waste disposal.
Many States were either in the process of revision
of current laws or have new laws pending. It also
appeared that more emphasis will be placed on
ground-water pollution problems in the new regu-
lations. There also appeared to be a trend toward
more rigid State control of these activities than
there had been in the past.
RECOMMENDATIONS TO A REGULATORY
AGENCY
A review of the literature on the subject of
the relationship between land disposal of solid
wastes and ground-water pollution, plus the survey
of practice employed by 21 States in this regard,
have suggested certain steps that regulatory agencies
can take to minimize problems in this area. The
term "regulatory agency" in the recommendations
to follow pertains to the governmental entity,
agency or department which has the primary
responsibility of regulating and licensing sanitary
landfill operations within the State.
1. The regulatory agency should have availa-
ble a geologist on its staff, preferably one trained in
the area of hydrogeology, to assist in the sanitary
landfill site selection processes within the State.
2. The geologist on the staff should begin to
accumulate geological data within the State and
broadly outline areas considered to be either good
or poor potential landfill sites. The activities in the
State of Illinois serve as a good example in this
regard.
3. The trend should be towards the require-
ment of more hydrogeologic and hydrologic field
data for sites that are questionable for landfill
operations. The burden of proof should be placed
on the landfill operator or owner. The staff geolo-
gist should be given the responsibility of deciding
when additional field data are required. It is the
opinion of the writer that much useful information
can be obtained even with a modest amount of
field testing.
4. The regulatory agency should be very
cautious when it comes to the approval of the
ground disposal of industrial wastes. An up-to-date
file should be maintained on various types of
industrial wastes, their degradation properties and
their effects on the aquatic environment. A litera-
ture search should be made periodically on this
topic.
5. The use of ground-water monitoring wells
should be considered in those cases where some
doubt exists as to future effects of a particular
landfill operation. This is somewhat akin to re-
quiring that water samples be periodically taken
downstream of an effluent discharge to maintain a
check on waste water disposal operations.
6. The regulatory agency should follow as its
basic policy the concept of trying to slow down the
refuse degradation process by minimizing water
percolation through the refuse mass. Slowing down
degradation provides more time for leachate attenu-
ation. Past experiences have demonstrated that
longer times provide the most effective safety
measure when it comes to separating sources of
ground - water contamination from points of
ground-water use.
7. The regulatory agency should not dis-
courage novel methods of collecting and treating
refuse leachates for certain installations where
proper monitoring and control can be exercised.
When considering facilities of this type, an impor-
tant lesson to be learned from waste water treat-
ment plant operations is that the smaller and the
more remote the treatment facility is, the greater
the likelihood of poor operation regardless of the
original design and the degree of automation.
8. It is virtually impossible to hold to a speci-
fied distance between a point of water use such as
a well and the site of a sanitary landfill. Tre-
mendous variations in the hydrogeology surround-
ing each site precludes the establishment of such a
published figure. However, lacking any field data
105
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the distance should be as long as possible in order
to have the built-in safety factor of greater time as
stated previously. Figures of 500 to 1000 feet are
not unrealistic if adequate field data are insufficient
to prove otherwise.
9. The regulatory agency should encourage
the practice of regional or district approaches to
solid waste collection and disposal. Economic
incentives should be available to provide funds to
make area-wide feasibility studies. This approach
will reap great benefits in the control of solid
waste disposal practices.
10. As a general rule, the regulatory agency
should prohibit the use of abandoned rock, gravel
or sand quarries as sites for the disposal of refuse of
any type. Standing water in such depressions is
usually nothing more than a visible direct link to
the ground-water supply. The leachate attenuation
mechanism under such conditions is completely
lost. If extensive hydrogeologic studies demonstrate
that the depression is in a discharge ground-water
zone it is possible that such a site can be used for
landfill disposal. However, nearby future ground-
water withdrawals may change the flow network
around such a site considerably. The burden of
proof plus any remedial safeguards should be
placed on the owner of such a site. As a rule, such
sites should not be used unless a thorough hydro-
geologic study is made.
11. The regulatory agency should support
some research work in this area. Some good exam-
ples are the studies on existing landfills which have
been conducted in California, Illinois and South
Dakota.
ACKNOWLEDGEMENTS
This investigation was supported . by funds
supplied by the Wisconsin Department of Natural
Resources. A report on the complete findings of
this study was submitted to the Department in
July, 1970. The writer wishes to express his grati-
tude to E. D. Cann and C. D. Besadny of the Wis-
consin Department of Natural Resources, as well as
the officials from the other States which partici-
pated in the survey for their assistance and
cooperation.
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Steiner, R. L., and R. Kantz. 1968. Sanitary landfill: a
bibliography. Public Health Service Publication no.
1819. U. S. Government Printing Office, 37 pp.
Stone, R., and H. Friedland. 1969. National survey of
sanitary landfill practices. Public Works, v. 100, p. 88.
U. S. Dept. of H.E.W. 1954-1963. Refuse collection and dis-
posal—an annotated bibliography, supplements B, C,
D, E, and F. Cincinnati, Ohio.
Univ. of Calif. 1952. Sanitary engineering research project,
an analysis of refuse collection and sanitary landfill
disposal. Tech. Bulletin no. 8, Series 37. 1 33 pp.
Univ. of Calif. 1955. Report on continuation of an investi-
gation of leaching of rubbish dumps. Sanitary Engi-
neering Research Laboratory. (Supplement to Publi-
cation no. 10), 26 pp.
Univ. of Calif. 1956. Report on continuation of an investi-
gation of leaching of rubbish dumps. Sanitary Engi-
neering Research Laboratory. (Supplement to Publi-
cation no. 10), 29 pp.
Vaughan, R. D. 1968. The national solid wastes survey, an
interim report. Presented at the 1968 Annual Meeting
of the Institute for Solid Wastes of the American
Public Works Association, Miami Beach, Florida. 53
pp.
Walker, W. H. 1969. Illinois ground water pollution. Jour.
AWWA. v. 61, p. 31.
Warner, D. L. 1969. Preliminary field studies using earth
resistivity measurements for delineating zones of
contaminated ground water. Ground Water, v. 7, no.
1, p. 9.
Water Treatment and Examination. 1969. Symposium on
effects of tipped domestic refuse on ground-water
quality, v. 18, part 1, pp. 15-69.
Weaver, Leo. 1956. The sanitary landfill-part II: selection
of site. American City. v. 71, p. 132.
Williams, J. H. 1969. Can ground-water pollution be
avoided? Ground Water, v. 7, no. 2, p. 21.
107
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DISCUSSION
The following questions were answered by A. E.
Zanoni after delivering his talk entitled "Ground-
Water Pollution and Sanitary Landfills—A Critical
Review."
Q. These questions pertain to the closing remarks
that have to do with new research: What research
would you suggest regarding ground-water pollu-
tion due to sanitary landfills? Do you feel that we
now have sufficient knowledge of the bydrogeology
of sanitary landfills to design, operate, and manage
solid waste disposal using this method? Also, why
no more research activity in the future? Do the
States feel we know enough now? This conflicts
with your recommendation for new concepts,
research, etc.
A. To answer the first question, I think the studies
of the type Illinois is doing right now are certainly
in the right direction. Also more studies on the
hydrogeology of sites would be in the right direc-
tion. I think that with the data available now, we
can do a better job if more is known about the
hydrogeology of the specific site involved. As far
as the degradation of the refuse is concerned, this
mechanism is fairly well understood. The big
question is what happens to the leachate once it
leaves the immediate vicinity of the disposal site.
To extrapolate information and data from one site
to another is very dangerous. We need to know
more of the hydrogeology of the site in question
in order to be able to predict more accurately what
the progression of the leachate will be and what the
impairment in ground-water quality will be at a
specified distance from the landfill site. Did I
contradict myself?
Q. Someone thought you said, "We need no more
research activity in the future. " The question is,
"Why no more research activity in the future?"
A. No, what I said was the survey of States indi-
cates little research activity in this area will be done
in future years. My personal feeling is that there
should be more. There is no question about that.
As for State agencies, there doesn't seem to be
much interest in this research area. I feel it is be-
cause we have had no long history of troublesome
pollutional situations and, quite frankly, this is
what we normally respond to. I am certain that
people in the political area would be more recep-
tive to research activities if they were hearing of
numerous cases of public health and nuisance prob-
lems resulting from sanitary landfill leachates. Very
candidly, these are the types of things which
motivate politicians and others to act.
Q. Let me take advantage of the moment and ask
a question. In any of the literature work, have you
found anyone working on such things as trace
organics or perhaps carcinogens?
A. No. I'm not aware of any such work. Trace ele-
ments, yes. We have some indication of this from
work in Pennsylvania and Brookings. There is very
little work on the degree of bacterial travel from
landfill sites.
Q. Couldn 't your miracle be explained by the fact
that most landfill sites are deliberately located far
from habitations?
A. I think that it is just simply the environment
provided by the soil regime. The active sites, the
availability of bacterial degradation activity, the
combination of moisture and air; it is just an ex-
cellent environment for the breakdown and degra-
dation of organics. It is like a good trickling filter
in a sense and then beyond that, it's merely a
dilution of the inorganics. Most soils provide an
excellent site for this active microbial degradation
activity, and perhaps, if the permeability is too
high, then this attenuation mechanism drops off
because the active sites are less available. Under
this situation we haven't got as much time for the
degradation to take place. Of course, when the
leachate starts getting into the rocks and crevices,
none of the attenuation mechanism is available. No
doubt the distance that landfill sites are placed
from habitation helps, but we should not forget
that nature does an excellent job of treating these
leachates.
Q. Might one not wish to maximize rather than
minimize the rate of refuse degradation if leachate
is being collected for treatment?
A. Absolutely. No question about it.
Q. This should be the most economical approach
if collection of leachate is practiced, correct?
A. Absolutely. If the design is such that you are
going to collect leachate, then you bring it into the
treatment plant at maximum rates. In other words,
you maximize biological activity in order to save on
dollars. This is a treatment cost we are not accus-
tomed to spending for this type of municipal
function, and, I would be very skeptical about
approving something like this unless it was con-
trolled and regulated properly. We all know of the
sophisticated waste water treatment plants built in
small towns and 2 weeks after the engineer leaves,
the rural policeman operates it once in awhile and
the treatment completely breaks down. This is
what might happen with this type of installation
unless it is monitored properly, so I would never
108
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favor this without good control. I would favor the
traditional approach with slow degradation because
then time is on your side. If you produce these
leachates and don't know what to do with them
after you produce them, then you have a problem.
Q. Do you believe that surface water pollution by
landfills may often be masked by other kinds of
pollution already present so that surface water
pollution by landfills may often be undetected?
A. That is partly true. I have not run across too
much data on this. Hughes of Illinois had some
data on this situation. He showed colored slides of
leachate oozing out of the sides of landfills and
then running into streams. There was a case in
Kansas City where an industrial waste deposited for
many years began leaching into a river supply.
Some of this happens and goes undetected. Some
of it has happened and has been detected but I
haven't run across a great deal of this type of
information in the literature.
Q. Wasn 't the California leachate data collected
under conditions of forced leaching?
A. Yes. In one of the studies when the water was
added to the refuse bins in an amount equal to
precipitation in the area, no leachate was generated
so the researchers had to turn on the faucet to get
some data. This is the main reason why in southern
California there is not generally a leachate problem.
There is not sufficient precipitation to generate
significant amounts of leachate. Remember, how-
ever, that a serious leachate problem can still occur
if the ground-water table rises up in the refuse
mass. This situation really causes active degradation
of organics with subsequent leachate production.
Q. Can the data that were collected in California
be applied to a true sanitary landfill?
A. No. You have to be very careful in extrapo-
lating some of these data. This is one point, I think,
that comes out very clearly from all these studies.
Q. Will all sanitary landfills produce a leachate?
A. It depends on the amount of water passing
through the refuse. There have been some sites
that have remained relatively unaltered for 20
years. But we must always keep in mind that
anything organic must degrade eventually. It is just
a matter of time. And if you maintain these semi-
dry conditions, it may not happen in 2 years
but it certainly will happen in 200 years. It has
to degrade if it is organic. It's only the rate that is
the big variable here.
Q. What are the moisture holding capabilities of
solid -waste?
A. I don't know a number to give you. This would
depend very much on the degree of compaction.
Q. Would you describe how solid waste disposal
can be designated to operate at a normal rate of
pollution so that solid waste decomposition and
resulting leachate production is manageable.
A. Well, I think with proper hydrogeologic data
inputs it is possible to arrive at a fairly reliable idea
of the degree of leachate production expected as
well as what eventually will happen to the leachate
once it gets into the surrounding terrain. I don't
think we'll be able to predict accurately the
progression of the leachate but at least we'll be
able to determine if potentially we are in a problem
area. The type of cover material and degree of its
compaction are extremely important, for example.
Another important item is how we handle the
surface water. If you grade most of the surface
precipitation away from the landfill site and you
have a relatively impervious top layer, you are
cutting down the degradation rate to a very mini-
mal extent and the impact of leachate production
will be quite minimal. There is no wonder that we
have potential water pollution problems after you
see how some of these landfill sites are operated.
With the type of data Illinois is beginning to put
out, we can approach this design a little more
rationally than we have in the past. At the present
time sufficient funds are not being expended in
the process of selecting a suitable site for disposal
of refuse. Some government officials think if you
spend more than several hundred dollars for this
purpose you are being extravagant. It is just not a
very popular governmental activity.
Q. I'm glad you said that because it is very
important to the next question, which I think
is a gig. What profession, geologist, hydrologist or
engineer, is presently best suited to conduct site
evaluation and design studies?
A. I would say a geologist. If I had $100 and had
to pick one, I would pick a geologist, or a hydro-
geologist. If I could afford it, I would use both
because some of the planning, some of the surface
soil quantity calculations, the grading, things of
this nature, are more in the engineer's bag, but with
limited funds I'd stick to a geologist.
Q. Is there a general tendency to locate landfills in
quarries, ravines and valleys that are very important
resources of ground-water recharge? If so, would a
change in approach help to protect ground water?
For example, bailing and stacking the solid waste.
109
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A. Absolutely. I think there is this trend simply
because these areas—just as they are—are totally
worthless for any other application, and if you can
show someone a restoration plan with these pretty
pictures I told you about before, where you can
show usable land being developed from some of
these sites, it's very attractive to the city fathers
and political leaders, particularly from a tax base
standpoint. So these sites are looked at first and 1
agree with the comment that oftentimes these are
recharge areas, and you have to be extremely care-
ful about using these sites. I had some experience
with one site northwest of Milwaukee that was a
gravel deposit site. It was used to mine gravel for
about 10 years and I was asked to look at it for
possible use as a landfill site and I was convinced
that it could be used. After taking 30 to 40 borings
we found there was a very thick, dense clay layer
underlining the whole area. The site was simply a
gravel glacial outwash sitting on top of a very
impervious lense of clay. This is an example of a
gravel-sandy area that could be used for the land
disposal of solid wastes. In contrast to the previous
example, deep limestone quarries with standing
water are generally very poor landfill sites because
this water is usually a direct outcrop of the ground-
water supply.
Q. Do you feel tbat the \\isconsin Department of
Natural Resources ivill respect your recommenda-
tion to hire a geologist?
A. There has been discussion of obtaining a geolo-
gist for assistance in two areas: water wells and
refuse disposal. Nothing has been done as of this
date. I've talked to some of the people there and
they agreed with me but Wisconsin, like all States,
is presently going through fiscal problems that
demand just about a total moratorium on hiring.
In summation, they have not listened to that
particular recommendation yet, but I suspect they
will. The people I have talked to seem to be
favorable to that direction.
Q. Could you add to your recommendations the
desirability of each State establishing ground-water
quality standards to add to those established by
HEW for surface waters?
A. That has been talked about a great deal. I've
talked to people personally about this. The enforce-
ment and the monitoring of something like this
would be awesome now. Maybe in the future we
can look in that direction or try this in isolated
cases, but the degree of variation in ground-water
characteristics from area to area precludes setting
up any kind of rigid standards. As you can imagine,
monitoring of the water quality would be very
expensive. Nonetheless, there are people who feel
that this is the direction we have to go. Eco-
nomically I can't see how we can justify it yet.
It's much easier to sample a moving stream than it
is to get to a ground-water table 100 feet below the
ground surface.
110
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Effect of Early Day Mining Operations on
_ o
Present Day Water Quality
by Leland L. Minkb, Roy E. Williams0, and Alfred T. Wallaced
ABSTRACT
Mining operations within the Coeur d'Alene District
of northern Idaho have been continuous for over 85 years.
Data presented herein demonstrate that early day mining
and milling wastes are now affecting the ground-water
quality in several locations. One of the affected areas is, the
lower Canyon Creek Basin located in the Coeur d'Alene
District near Wallace, Idaho.
Ground-water pollution of the Canyon Creek Basin
results from leaching of old mine tailings chat are inter-
mixed with the upper part of the sand and gravel aquifer.
High zinc, lead and cadmium concentrations occur in
ground water and soil samples taken from the portion of
the sand and gravel aquifer containing old mine tailings.
Analysis of water samples from a settling pond lo-
cated in the upper portion of the study area indicates that:
the pond water is not the source of the heavy metal con-
centrations found in the ground water. However, the water
from the pond's decanting system provides recharge to
ground water and compounds the problem.
INTRODUCTION
Purpose and Scope of Study
Interest in the environment during recent
years has focused considerable attention on the
quality of several streams in industrialized areas of
northern Idaho. Much of the attention is centered
around one of Idaho's most important industries
(mining). Consequently, researchers at the Uni-
versity of Idaho and the Idaho Bureau of Mines
and Geology have established a program under the
support of the U. S. Bureau of Mines to collect,
analyze, and interpret water quality information so
that industries involved would have a basis for
corrective measures where needed.
Much of Idaho's mining activity is in the
Coeur d'Alene River Basin located in the panhandle
region of northern Idaho within the Bitterroot
Range of the Northern Rocky Mountains. This
paper is concerned with a tributary of the South
Presented at the National Ground Water Quality
Symposium, Denver, Colorado, August 25-27, 1971.
"Research Fellow, College of Mines, University of
Idaho, Moscow, Idaho 83843.
cProfessor of Hydrogeology, College of Mines, Uni-
versity of Idaho, Moscow, Idaho 83843.
"Professor of Civil Engineering, College of Engineer-
ing, University of Idaho, Moscow, Idaho 83843.
Fork of the Coeur d'Alene River called Canyon
Creek, the scene of mining activity for over 85
years (see Figure 1).
This study was designed to: (1) report on the
water quality of Canyon Creek; (2) report on the
ground-water quality of the Canyon Creek Basin;
and (3) attempt to gain an understanding of the
causes and sources of high heavy metal concentra-
tions known to exist within the ground water and
surface water of the Canyon Creek Basin. Initially,
point number 3 was particularly perplexing because
metal concentrations in ground water and surface
water are considerably higher than metal concen-
trations in the effluent from the only significant
tailings disposal system in the valley.
DESCRIPTION OF STUDY AREA
Canyon Creek flows in a relatively narrow
canyon for approximately 12 miles. Its headwaters
are in the Bitterroot Mountains at the Idaho-
Montana border; and its mouth is at the confluence
with the South Fork of the Coeur d'Alene River at
Wallace, Idaho (see Figure 1). Canyon Creek basin
has a maximum elevation of 6785 feet and a mini-
mum elevation of 2760 feet, giving a maximum
relief of 4025 feet. Many of the slopes of the area
are inclined at an angle of 30°; the terrain is very-
rugged. Most of the Canyon Creek valley is steep
and narrow; only one portion of it approaches a
width of one-half mile. The entire basin occupies
an area of 21 square miles.
The population of the Canyon Creek drainage
basin is approximately 250 (Driscall, 1970).
Tue main industry along Canyon Creek is
mining. At present, there is one large operating
mine and several smaller working mines in the
basin.
BASIN ANALYSIS
Climate
The climate of the Canyon Creek basin is
strongly seasonal with mild temperatures prevalent
during the summer months and below-zero temper-
atures common during the winter months.
Most of the precipitation is in the form of
111
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CANADA
WASHINGTON
MONTANA
, COEUR D'ALENE
1. CANYON CREEK ABOVE PONDS
2. POND INFLOW
3. SOLUMWELL
4. SEEP1
5. POND OUTFLOW
6. SEEP 2
7. SEEPS
8. LOWER TRENCH
9. SEEP 4 '
10. LUDWICKWELL
11. BILTEWELL
12. CANYON CREEK
BELOW PONDS
MONTANA
CANYON
CREEK
WAllACE
SOUTH FORK COEUR D'ALENE RIVER
B
'WOODLAND
PARK
r\
_J \
WALLACE
1OOO
"STATUTE MILES
Fig. 1. Map of Canyon Creek Drainage Basin and sampling points near Woodland Park, Idaho.
snow which falls during the winter months. Thun
dershowers persist from late June through part ot
August. In the latter part of Scpicmher and early
spring a short rainy season can usually be expected.
Snow at higher elevations accumulates in large
drifts and, where protected from the sun, may
remain until Lite August. Some deep snows in
cirque b.isms may persist until covered by the
next winter's snowfall. Subsurface and surface
runoff from these drifts supply runoff to Canyon
Creek and other .streams throughout the year. The
average annual precipitation ot the Canyon Creek
basin at Woodland Park is 44.7 inches; consequent-
ly, ample water is available lor recharge ot ground
water in buried valley aquifers such as that along
Canyon Geek.
Geology
The rocks of Canyon Creek basin consist
mainly of the Precambrian Belt Series. The rocks
are fine-grained argillites and quartzues associated
with smaller amounts of carbonate-bearing, dolo-
mitic rocks. Quartz and sericite are the principal
minerals within the Belt Series; accessory minerals
include teldspar, muscovite, magnetite, ilmenitt,
zircon, tourmaline, rutile, and titanite. Representa-
tive chemical analysis of the Belt Rocks is presented
in Table 1.
Table 1. Chemical Analysis of Belt Rocks in Percent of
Unaltered Rock in Coeur d'Alene District'
O.VJiiV.s /Viv. /;,'
SiO,
AKO,
Fe:O,
FeO
MgO
CaO
Na:O
K;O
TlO;
P,O<
MriO
CO;
H,O
67.4
I ? . 8
2.4
1 . 2 X
2.1 I
1.76
3 '.i
0.49
0.12
0.1)5
2.51
1.35
100.15
From: Hobhs and others, 1965, p.28.
112
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3800'—
3600'_
3400'—
3200 _
3000'_
2800'_
LACIAL
TERRACE
CANYON
CREEK
-ALLUVIUM
BED ROCK
(BELT SERIES)
2345
DISTANCE (X 1000 FT.)
I
6
Fig. 2. Cross section B-B1 of Canyon Creek Basin at Wood-
land Park showing valley configuration.
The river valleys are partially filled with alluvi-
al deposits which vary in thickness from less than
one foot to several hundred teet. Canyon Creek is
filled with alluvium to an unknown depth. The
alluvium consists mostly of unconsolidated sand
and gravel; large rounded boulders are prevalent.
Tailings from early mine milling operations are
mixed with river gravels within many valley areas.
Figure 2 is a cross section (B-B1 in Figure 1) of the
Canyon Creek valley near Woodland Park which
shows the configuration of the valley and alluvium.
There is evidence of Pleistocene glaciation at
the head of the Canyon Creek basin. Glacial ma-
terial is scattered throughout the basin (Hobbs and
others. 1965, pp. 68-69).
Hydrology
Stream flows within the Canyon Creek basin
are extremely variable. High flow occurs during the
spring months coincident with snow melt and a
rather low flow occurs during the fall when ground-
water discharge and melt from remnant drifts are
the major source of water. Spring floods caused by
rain and melting snow occur.
The water table along Canyon Creek is shallow
with springs in evidence throughout the year, but
particularly during the spring months. The valley
areas of Canyon Creek produce an adequate
ground-water supply for domestic use because of
the high permeability of the sand and gravel aqui-
fer. However, much of the domestic water supply
comes from the convenient springs and creeks in
the basin or from adjacent basins because of the
poor quality of ground water. Water costs in the
valley are relatively high.
PREVIOUS WORK IN AREA
Mink, Williams and Wallace (1971) initiated
the first effort at unraveling the pollution problem
on Canyon Creek. Prior to that study, speculation
had attributed high metal concentrations directly
to tailings pond effluent. An increase in zinc, cad-
mium, and fluoride concentrations were observed
in the South Fork of the Coeur d'Alcne River
downstream from the entry of Canyon Creek. A
mean concentration of 3.07 ppm zinc was observed
below the confluence of Canyon Creek with the
South Fork while upstream portions of the South
Fork of the Coeur d'Alene River showed a mean
zinc concentration of 0.18 ppm zinc. In short,
Canyon Creek adds considerable zinc to the South
Fork.
Mink, Williams and Wallace (1971) noted that
the concentration ot zinc in Canyon Creek was
approximately three times that found in the efflu-
ent from the settling pond located near Canyon
Creek. Springs and seeps analyzed downgradient
from the settling pond gave preliminary evidence of
an increase in zinc concentration in ground water
with distance downgradient from the settling pond.
More recently, soil and sediment samples
(much of which consist of old tailings) collected
from the Canyon Creek bed and along the sides ot
the stream have been lound to contain up to 6.0
percent lead and 4.4 percent zinc. Copper concen-
trations of the sediments have a mean value of
approximately 430 ppm.
Analyses of plants collected from the Canyon
Creek area have shown mean zinc, lead, and copper
concentrations of 80 ppm, 60 ppm, and 10 ppm
respectively. These values are about four times
higher than respective concentrations in plants
growing in areas which did not receive tailings in
early mining days.
More detailed analysis ot the samples of
intermixed soils and old mine tailings will be pre-
sented in a subsequent paper by Galbraith, Williams,
and Siems.
PROBLEM DESCRIPTION
In August, 1968 a series of two settling ponds
were established along Canyon Creek near Wood-
land Park. The mill and mine wastes are piped
approximately six miles to these ponds. The valley
area where the ponds were established is approxi-
mately 2.5 miles long and 0.4 miles wide at its
widest point. The ponds are located on the upper
portion of this wide valley area (see Figure 9). The
lower Canyon Creek valley is filled with extensive
alluvial deposits. These are the deposits on which
extensive "jig tailings" or coarse mine wastes from
early day mining operations have been deposited.
113
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Because of inefficient early recovery practices,
much of the "jig tailings" are high in metal content.
Tigging is a mechanical gravity concentration
process. It is used to separate heavy grains from
light grains. In its simplest form, equipment con-
sisted of a box without a top and with a perforated
bottom. A shallow bed of grains was formed by-
fluctuating water currents. The heavy grains passed
to the bottom; intermediate mixtures remained in
the middle; and the lightest rose to the top of the
bed. Some of these devices were hand-operated or
power-driven units in which the jig was moved up
and down in the water-, others were stationary jigs
in which the water was pulsated by plungers or
paddles.
The jig tails along Canyon Creek were pro-
duced by the concentrators upstream in the canyon
from the late 1880's until the late 1920's and early
1930's when it first became economically feasible
to recover the zinc.
During the years mentioned, there was no
apparent attempt made to recover zinc and it all
went to the tailings which display the high values
in zinc that occur in the deposits along this valley
bottom. Typical tails for this period showed lead
assays of 0.90 percent to 1.5+ percent. No assays
were performed for zinc in the feed, concentrate,
or tails, but the majority of the zinc obviously
went with the tails.
Residents of the area below the tailings pond
reported a rise in water levels of their wells
shortly after the settling ponds were put into use.
Because of this observation and the findings re-
ported above, a more thorough study of the basin
was clearlv needed.
SAMPLING PROCEDURE
Twelve sampling points were established and
monitored from June 1969 through April 1970
with major emphasis on the summer months. These
dates include only the period after settling ponds
were put into operation by the major mining
company located in the river basin. During the
study no satisfactory sampling point for ground
water in the sand and gravel aquifer was found
above the ponds. The water table does not "crop
out" at the ground surface as it does below the
ponds, and no wells are available at an appropriate
location. However, the mining company involved
collected and had analyzed one sample of ground
water intercepted during the construction of one of
the tailings ponds. The results of this analysis are
presented in Table 2.
The samples collected include both the inflow
and outflow from the settling pond. Seepages,
Table 2. Concentrations of Metals in Ground Water
Above Tailings Ponds' (in ppm)
Sample :Vo. Copper Lead Zinc Iron Manganese
SP-1 0.008 0.137 5.96 0.067 0.180
1 Data contributed by mining company owning tailings
ponds; only one sample available.
springs, and wells were analyzed to give informa-
tion on the ground-water quality below the pond.
All springs and seepages are listed as seepages;
however, most such discharge points are actually
springs throughout most of the year. Seepage 1 is
located at the lower base of the settling pond em-
bankment which is approximately 50 feet thick.
Seepage 2 is located 80 feet to the east side of the
lower settling pond between the settling pond and
Canyon Creek. Seepage 3 is located 350 feet south
(downgradient) of the settling ponds and Seepage 4
is located 2300 feet south of the settling ponds.
Three wells analyzed within the basin were the
Solum Well located 200 feet west of the settling
ponds, Ludwick Well located 2450 feet south
(downgradient) of the settling ponds and Bilte
Well located 3750 feet south of the settling ponds.
Samples were also taken from a trench 2100 feet
downgradient from the settling pond. Samples of
Canyon Creek above and below the settling ponds
were analyzed to determine the effect of settling
pond effluent and discharging ground water on the
stream (see Figure 1). All wells and seepages obtain
water from the sand and gravel aquifer occupying
the valley.
DATA ANALYSIS
The samples were collected in one-liter poly-
ethylene bottles which were washed in a dilute
HCl solution and then rinsed with deionized. dis-
tilled water prior to sample collection. The sample
bottles were rinsed thoroughly with the .sample
water at the time of collection. Immediately after
collection the samples were analyzed tor tempera-
ture, pH. and electrical conductivity.
The samples were then analyzed for arsenic
(As), calcium (Ca), cadmium (Cd), chromium (Cr>.
copper (Cu). iron (Fe), potassium (K). magnesium
(Mg), manganese (Mn), sodium (Na), nickel (Ni).
lead (Pb), and zinc (Zn) using a Perkin-Elmer model
303 atomic absorption spectrophotometer.
Acidification of Samples Containing Iron, Lead
and Zinc
Experimentation with acidified and unacidi-
fied samples prior to analysis for lead and zinc
114
-------
revealed that acidification increased the concentra-
tions of both ions. Two explanations are possible:
acidification is known to minimize adsorption of
these ions onto the walls of the container;however,
experimentation revealed that acidification also
strips off ions adsorbed to the solids suspended
in the samples, especially when those suspended
solids are mine tailings. All samples analyzed during
this project were collected in polyethylene bottles;
consequently, adsorption of ions onto container
walls would be expected to be minimal. Therefore,
the high concentrations of lead and zinc observed
in acidified samples are interpreted as being caused
by removal of ions from suspended matter in the
sample. Filtering of samples was avoided because of
the fear of the adsorption of heavy metals onto the
filter paper.
If the suspended solids settle out in the
natural environment (as in stream channel deposits)
the ions adsorbed thereon may never become
available to aquatic life. On this basis, and because
of the above complications, the decision was made
to utilize unacidified samples for analysis. The sus-
pended solids were allowed to settle and the
supernatant was analyzed. Inherent in this ap-
proach is the assumption that the partition of ionic
species between water and solid was at equilibrium.
The data represented herein are believed to be as
representative as possible of ion concentrations
actually in the water, rather than a combination of
ions in the water and ions added to, or removed
from, the water by a change in the physical-
chemical environment within the sample after
collection.
Finally, extraction techniques were not uti-
lized in this stud\\ Such techniques are frequently
used to lower the detectability limit of dissolved
ions by the atomic absorption spectrophotometer.
However, it was observed that results were difficult
to reproduce when this technique was employed so
the decision was made to settle for slightly higher
limits of detectability.
WATER QUALITY
Because of the toxic nature of several ele-
ments in high concentration, notably cadmium,
copper, lead, and zinc, emphasis has been placed on
these elements. The area is nationally famous for
its silver, lead and zinc production, with copper
and cadmium being important by-products from
the mining operations.
Interviews with residents of the Woodland
Park area indicated that water levels in wells have
risen since the installation of the tailings ponds by
the mining industry. Inspection of the valley
downgradient from the settling ponds revealed that
septic tanks and water meters are under water
during a portion of the year. Preliminary analysis of
the ponds revealed that the ponds were not directly
contributing the high zinc concentrations found in
Canyon Creek. The pond water contains a zinc
concentration . of approximately 1.4 ppm while
Canyon Creek has a concentration of approximate-
ly 4.8 ppm zinc (Mink, Williams and Wallace, 1971).
Since this preliminary study the outflow from the
tailings pond decant system has been sampled. This
water has a mean value of 1.1 ppm zinc (based on
5 samples) which is slightly lower than that found
in water within the pond. The seepages analyzed
from the basin's sand and gravel aquifer show a
high zinc concentration in ground water a con-
siderable distance from the ponds (see Figure 3).
ZN
PPM
38
36
34
32
30
28
26 -
24
11
20
18
16
LOWER
T«ENCH°HUDW,CK
SEEP 4
°SOLUM WELL
SEEP 1
CANYON CREEK
ABOVE POND
POND
INFLOW
POND
'OUTFLOW
1
3456789
DISTANCE (X 1000 FT.)
CANYON c
CREEK
BELOW
PONDS
BUTE WELL
1O 11
Fig. 3. Graph of mean zinc concentration vs. distance for
Canyon Creek Basin near Woodland Park, Idaho (1969-
1970).
Samples from seepage 2, seepage 4, lower trench,
and Ludwick Well are significantly higher than the
rest of the samples in zinc concentration. These
concentrations range from a mean of 31.0 ppm
zinc for seepage 4 to 37.2 ppm zinc for seepage 2.
Solum Well, which is located about 200 feet west
of the final (lower) pond, displays a mean zinc
concentration of 13.6 ppm. It is not possible to
115
-------
determine whether this relatively high concentra-
tion is related to recharge from the tailings pond
system. We suspect (but cannot prove) that it
reflects ground water which has moved through old
tailings above the pond system; the limited availa-
ble analyses of this water are presented in Table 2.
Bilte Well, located downgradient from the settling
ponds, had a mean zinc concentration of 0.6 ppm
which can be interpreted to mean that ground
water in the lower portion of the basin is recharged
in a direction perpendicular to the axis of the
valley (see Figure 2).
The zinc, lead and cadmium concentrations
in ground water not associated with old mine tail-
ings in the Coeur d'Alene basin is < .1 ppm (Mink,
Williams and Wallace, 1971). Additional data col-
lected since that study support this conclusion.
Based on 14 samples, an increase in zinc concen-
tration was found in Canyon Creek when mean
concentrations from samples above the settling
ponds were compared to mean values below. Mean
zinc concentration in Canyon Creek above the
ponds (4 samples) was 3.1 ppm while below the
settling ponds mean zinc concentration (14 sam-
ples) was 5.9 ppm.
.34-
.33-
.30 .
.16-
.14 _
.11-
Lowe*
TIENCH
Cd
(PPM),
: IUOWICK Will
Cadmium concentration follows much the
same trend as zinc concentration (see Figure 4).
Mean cadmium concentrations ranged from 0.40
ppm to 0.20 ppm for seepage 2, seepage 4, lower
trench, and LudwickWell. Cadmium concentrations
were below the detectable limit of 0.02 ppm for
Canyon Creek above the settling ponds, while a
mean cadmium concentration of 0.04 ppm was
observed in Canyon Creek 7800 feet below the
settling ponds at the lower end of the valley. The
inflow and outflow of the settling ponds was
always below the detectable limit of 0.02 ppm
cadmium.
Lead concentrations are also higher in the
seepages than in the inflow or outflow of the
settling ponds. Except for 0.1 ppm lead observed
in one sample from Ludwick Well, no detectable
lead (detectable limit of 0.1 ppm) was found in
Canyon Creek, any of the wells, or in the settling
pond outflow. Mean lead concentrations (13 sam-
ples) in seepage 1, seepage 2, seepage 3, seepage 4,
and the lower trench range from 0.6 ppm to 1.6
ppm lead (see Figure 5).
U-
1.6-
14-
LJ_
LEAD
U>_
("«)
Jt-
.6-
.4-
°SEEP 1
cSSEP ^ OSEEP 4
°SEEP 3
1OWIB
c TRENCH
- INLOW
CANTON CK. » SOLOM
A.O« = wm
A.O
CANTON CK.
I 1 3 4 5 6 " 7 •» 10 11 'I 13
DISTANCE (X 1000 FT.)
Fig. 5. Graph of mean lead concentration vs. distance for
Canyon Creek Basin near Woodland Park, Idaho (1969-
1970).
.06 _
.04 _
OSOLUM Wilt
OSIEP 3
CSIEP I
CANTON CK.
at— -
CANTON CK. POND POND
AIOVE INFLOW OUTFLOW llltl WELL
Q. i loi l°; t t a I i I f -
I 13456 7 • 9 10 11 11
DISTANCE
-------
ground water decreases to a mean value of 4.27 at
seepage 4 located 2300 feet dovvngradient from the
settling pond. The pH of Bilte Well is higher than
the other ground-water samples, presumably be-
cause of recharge of uncontaminated ground water
entering the aquifer near the valley sides.
1.0 _
Cu
(ffM)
0,8 -
POND
OUTFLOW
SOLUM
Will
POND
INFLOW
StfP 4
SffP 3 ] LOWER
LUDWiCK
Wflt
CANTON CK.
BflOW
DISTANCE (X 1000 FT.)
Fig. 6. Graph of mean copper concentration vs. distance for
Canyon Creek Basin near Woodland Park, Idaho (1969-
1970).
8-
POND
INFLOW
CANTON CK.
7*. ABOVE
POND
o OUTFLOW
CANTON CK.
BELOW
PN
SOLUM WELL
SEEP
2
EP 3
ollLTE WELL
0 LUDWICK WILL
JEEP 4
R TRENCH
3 * i t 7 S 9
DISTANCE (X 1000 FT.)
10 11 12
Fig. 7. Graph of pH vs. distance for Canyon Creek Basin
near Woodland Park, Idaho (1969-1970).
[VIUM
2700 _
2600
DISTANCE (X 1000 FT.)
Fig. 8. Longitudinal cross section (A-A1) of Canyon Creek
Basin near Woodland Park showing proposed flow system.
GROUND-WATER FLOW
Figure 8 shows a longitudinal cross section
(A-A1) of Canyon Creek with a proposed flow
system which is influenced by recharge from set-
tling ponds. The depth of the aquifer is estimated
because of lack of data on depth of the alluvium
in the valley.
Before the establishment of the settling ponds,
it is believed the major discharge area was at the
lower end of the valley where the valley narrows
and the alluvium thins out. The proposed flow
system shown in Figure 8 indicates that a discharge
area exists from a point directly below the settling
pond to the lower end of the valley. Evidence for
this conclusion consists of several springs which
now emerge between the ponds and the downgradi-
ent end of the valley even during dry weather. The
discharge area below the settling ponds brings
ground water into contact with the upper portion
of the sand and gravel aquifer containing the jig
tailings. Virtually all ground water discharges into
Canyon Creek before leaving the valley because
thickness of the sand and gravel aquifer thins to
zero in a narrow constriction above the confluence
of Canyon Creek and the South Fork of the Coeur
d'Alene River. A water table map of the Woodland
Park area shows the water table is near the surface
throughout the valley (see Figure 9).
DISCUSSION AND RECOMMENDATIONS
The data presented herein indicate a ground-
water pollution problem with respect to low pH
and high concentrations of cadmium, copper, lead,
and zinc in the sand and gravel aquifer of Canyon
Creek. The concentrations of cadmium, lead and
zinc are in some cases above the limits set for
domestic water supply by the U. S. Public Health
Service. The concentrations observed would also
be detrimental to many aquatic organisms. Con-
centrations of cadmium, copper, lead, and zinc
found in Canyon Creek below the settling ponds
are well above that reported toxic to trout and
other forms of aquatic life (McKee and Wolf, 1963,
pp. 149, 169, 209, and 294). Of the four elements
above, only copper (which is not particularly high)
appears to be derived directly from the tailings
ponds within the basin. Cadmium, lead, and zinc
show a much higher concentration in the ground-
water samples than that observed in samples from
the tailings ponds. The high concentrations of lead
and zinc in soil samples, along with the high con-
centration of these elements in ground water in the
sand and gravel aquifer above and below the ponds
in the valley, indicate that the source of metals is
within the aquifer located below the water table.
11:
-------
TOPOGRAPHY AND WATER TABLE CONTOURS
FOR BASIN OF CANYON CREEK, IDAHO
1000
CONTOURS
TOPOGRAPHY
WATER TABLE
1.
-->
3.
H .
5.
6.
7.
8.
9.
10.
11.
1 2 .
13.
14.
15.
16.
17.
18.
CANYON CREEK
CONFLUENCE
CANYON CREEK
BELOW
BILTE WELL
SEEP 5
BUSSEL WELL
LUDWICK WELL
SEEP 4
LOWER TRENCH
WOODLAND PARK
WELL
SELP 3
UPPER TRENCH
SEEP 1
SEEP 2
POND OUTFLOW
SOLUH WELL
LOWER POND
UPPER POND
INFLOW
CANYON CREEK
ABOVE
Fig. 9. Topography and water table contours for basin of Canyon Creek, Idaho.
Essentially all of the ground water moving through
the aquifer discharges into Canyon Creek before it
enters the South Fork of the Coeur d'Alene River
because the thickness of the sand and gravel aquifer
diminishes to /cro in a narrow constriction immedi-
ately upstream from the South Fork.
The decrease in pH of the ground water down-
gradient indicates that a mechanism is present
which solubilizes the metal sulfides of old mine
tailings. The sulfide ion then becomes oxidized to
sulfate ion. This reaction creates sulfuric acid which
accounts tor the increase in H+ ion concentration
and the decrease in pH, The H+ ions can then
undergo cation exchange to allow the metal to go
into solution. This process, along with an evaluation
of the role played by microorganisms, will be
discussed in greater detail in a subsequent paper by
Galbraith, Williams and Siems. This proposed
mechanism could account for the anomalous pH
values and metal concentrations observed in the
ground water of the Canyon Creek basin. Recharge
caused by the establishment of the settling ponds
has apparently raised the water table of the valley
into the mixture of tailings and sediments. This
rise has resulted in additional metal sulfides from
old jig tailings being subjected to the mechanism
described above.
Trenches from three to fourteen feet deep
have been constructed by the mining company
concerned and have alleviated the problem to some
extent by lowering the water table approximately
one to four feet. This drop eliminated some of the
seepages in the valley.
To minimize the problem, it is believed that
discharge of the settling pond effluent should be
diverted from the unlined ditch (upper ditch in
Figure 9) where it now flows, to Canyon Creek, a
distance of approximately 400 feet. A similar result
might be realized by lining the ditch.
The seepage from the settling ponds should
be evaluated from the point of view of recharge ot
ground water by the ponds. At present, the amount
of recharge being contributed by this source is
unknown. Experience in other parts of the Coeur
d'Alene valley has shown that a peripheral tailings
discharge system minimizes seepage. The slimes
118
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from the milling operation are relatively effective
in sealing the ponds. An appropriate technique is
described by Kealy and Busch (1971) and Kealy
and Soderberg (1969).
Deep trenches constructed at an angle across
the valley and discharging into Canyon Creek
would further lower the water table below the old
mine tailings (jig tailings) and also help solve the
problem.
Immediate measures needed include ascertain-
ing that the ground water emanating from the
springs and seeps in the lower part of the valley is
not consumed by animals or humans. The concen-
trations of lead observed constitute the primary
reason tor this recommendation. It is also advisa-
ble that the ground water along a band downgradi-
ent from the ponds not be consumed.
It must be noted that it is not possible to say
with certainty that elimination of recharge of
ground water by the tailings pond system will com-
pletely eliminate the pollution of ground water. It
is apparent that the critical factor is whether or not
the old jig tailings in the upper portion of the sand
and gravel are saturated. On the basis of testimony
by area residents, the pond discharge has raised the
water table considerably; however, it is not certain
that the water table did not periodically extend up
into the layer of old tailings prior to the installation
of the tailings ponds. No data are available under
original conditions on which to base an opinion.
However, it is certain that the tailings pond effluent
is contributing to the problem.
In addition to providing an explanation for
the heavy metal ion concentrations observed in
ground water in the sand and gravel aquifer of Can-
yon Creek, and in addition to accounting for the
heavy metal concentrations in Canyon Creek, this
study has demonstrated the need for thoroughly
evaluating all aspects of a waste disposal site prior
to its use. Had the conditions in Canyon Creek been
understood in advance of pond construction, the
portion of the problem attributed to the ponds
could have been essentially eliminated by one of
several design procedures. The industry has now
adopted a process of careful site evaluation prior to
use, including sampling of initial water quality.
This procedure not only facilitates proper design;
it also enables the company or other entity in-
volved to specify precisely what effect its operation
has had on the environment in the event that any
post-installation problems arise.
SUMMARY
1. The Canyon Creek basin has been the loca-
tion of mining activities for over 85 years. Prior to
1968, most of the waste generated by concen-
trating plants associated with these operations was
discharged into Canyon Creek. This study includes
the period of time after the installation of tailings
ponds to improve water quality. The study was
designed to evaluate and explain the heavy metal
concentrations known to occur in the ground water
and surface water of Canyon Creek basin.
2. Water samples were collected from 12
stations within the Canyon Creek basin during a
period from June 1969 through April 1971 and
analyzed for 13 metals along with electrical con-
ductivity, pH, and temperature.
The analyses showed that the concentrations
of the elements zinc and cadmium are high in
ground water and surface water. Lead is high in
ground water discharging at some locations. Lead,
zinc, and cadmium concentrations are lower in
tailings pond effluent than in surface water or
ground water. Zinc and cadmium increase in Can-
yon Creek as ground water which has moved
through the valley's sand and gravel aquifer dis-
charges into Canyon where the aquifer thickness
diminishes to zero in the stream channel.
Soils were sampled in an effort to obtain an
estimate of the amount of heavy metals contrib-
uted to the upper portion of the basin's sand and
gravel aquifer by the emplacement of a layer of
old "jig" tailings during the early days of mining in
the basin. The data indicate that the upper portion
of the aquifer contains up to 6.0 percent lead and
up to 4.4 percent zinc.
3. The settling pond, established on the upper
end of an extensive sand and gravel alluvial deposit
which contains old mine tailings, is acting as a
recharge area for the basin aquifer and has appar-
ently resulted in a rise of the water table within
the basin below the settling pond. This rise has
contributed to the raising of the water table into
old mine tailings deposited during early mining
days. When saturated, these tailings become subject
to lixiviation by ground water.
4. The ground-water quality of the lower
portion of Canyon Creek is the direct result of
leaching of the old mine tailings (jig tailings) which
have been deposited by the past mining operations.
As a result of this process, high concentrations of
cadmium, lead, and zinc occur in the ground water.
The process also results in a lowering of pH with
distance away from the settling ponds.
5. Solution of the problem can be accom-
plished by utilization of different design techniques
for tailings ponds in this type of environment.
Methods described by Kealy and Soderberg (1969)
119
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and Kealy and Busch (1971) should prove success-
ful.
6. It is not possible to determine what the
natural conditions were because no data are availa-
ble. The water table may occasionally rise into the
layer of old tailings even under natural conditions.
It is certain, however, that the ground-water re-
charge contributed by the tailings pond effluent
intensifies the problem.
7. This study emphasizes the advisability of
thoroughly evaluating an area before disposal of
wastes is initiated. Without such an examination it
is difficult to accurately delineate the role played
(or not played) by the waste disposal facility.
ACKNOWLEDGMENTS
The writers are grateful to Mr. Gordon Graig
and Mr. William McKee, Hecla Mining Company,
Wallace, Idaho for their assistance in investigating
the ground-water problems in the vicinity of Can-
yon Creek. This project was supported by U. S.
Bureau of Mines Contract No. HOI 10088, which is
directed at determining what types of wastes tail-
ings ponds can be expected to treat adequately.
REFERENCES CITED
American Public Health Association and others. Standard
methods for the examination of \\aste\vater. 1965.
Boyd Printing Co., Inc.. Albany, New York, 744 pp.
Driscall, Marie. 1970. Wallace Chamber of Commerce.
Wallace, Idaho (written communication).
Ellis, M. M. 1940. Pollution of the Coeur d'Alene River and
adjacent waters by mine wastes. Special Scientific
Report 1, U. S. Bureau of Fisheries, 61 pp.
Hobbs, S. W.. A. B. Griggs, R. E. Wallace, and A. B.
Campbell. 1965. Geology of the Coeur d'Alene Dis-
trict. Shoshone County. Idaho. Washington. U. S.
Govt. Printing Office, U. S. Geol. Survey Prof. Paper
478, pp. 1-69.
Idaho Bureau of Mines and Geology. 1964. Mineral and
water resources of Idaho. Washington, U. S. Govt.
Printing Office. Special Report no. 1, pp. 276-278.
Idaho Department of Commerce and Development. 1963.
Idaho almanac, territorial centennial edition, 1863-
1963. Boise. Idaho, pp. 1-78.
Kealy, C. D., and R. L. Soderberg. 1969. Design of dams for
mill tailings. U. S. Bureau of Mines, Information
Circular 8410. 49 pp.
Kealy, C. D.. and R. A. Busch. 1971. Determining seepage
characteristics of mill-tailings dams by the finite-
element method. U. S. Bureau of Mines, Report of
Investigations 7477, 113 pp.
McKee, J. E., and H. W. Wolf. 1963. Water quality criteria,
2nd ed.. California State Water Quality Control Board,
Sacramento, California, Pub. no. 3-A, 404 pp.
McKee, William. 1971. Assistant Manager of Mills, Hecla
Mining Company, Wallace, Idaho (personal communi-
cation).
Mink, L. L., R. E. Williams, and A. T. Wallace. 1971. Effect
of industrial and domestic effluents on the water
quality of the Coeur d'Alene River Basin, 1969, 1970.
Idaho Bureau of Mines and Geology, Moscow, Idaho.
Pamphlet 149, 95 pp.
U. S. Bureau of Mines. 1969. Minerals yearbook, vol. I-II.
Washington, U. S. Govt. Printing Office, 1194 pp.
U. S. Department of Commerce. 1970. Climatological data,
Idaho, annual summary. Washington, U. S. Govt.
Printing Office, v. 73, no. 13.
DISCUSSION
The following question was answered by Leland L.
Mink after delivering his talk entitled "Effect of
Early Day Mining Operations on Present Day Water
Quality" (coauthored by Roy E. Williams and
Alfred T. Wallace).
Q. hit't the significance level of lead and cadmium
in water much less than your lowest detectable
limit of 0.1 ppm, .005 ppm Public Health Service
upper limit? Does this affect your conclusions?
Perhaps the problem may be even worse than
stated.
A. This can be true. Our detectable limit is quite
high and again we're hoping to improve this situa-
tion with our new equipment. Now it is possible
that when we receive the results of a few samples
we have sent out, the concentrations of some of
these elements, for instance, lead, may prove to be
present in concentrations which are above the
Public Health Service limits but still below our
detectable limits. We may have to revise some of
our ideas concerning what is polluted and what is
not polluted within the basin at that time. How-
ever, our objective in this study was to unravel the
ground-water pollution problem with respect to
sources and causes. We did not set out to monitor
exclusively for compliance with standards. Our data
did enable us to meet our objective.
120
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Bull Session 3—Solid Waste—Its Ground-Water Pollution Potential
Session Chairman: Jack W. Keeley, Chief, National
Ground Water Research Program, Environmental
Protection Agency, Robert S. Kerr Water Re-
search Center, P. 0. Box 1198, Ada, Oklahoma
74820.
Jack W. Keeley, Lead Bull:
Dr. Zanoni will not be able to be with us. The
subject is solid waste and landfill. By recognition,
get up to the microphone and ask your question,
and we will discuss it; hopefully, we'll get a little
controversy going. I hope we can make the thing a
two-way discussion. Who wants to be first? Does
anyone want to start with anything in particular?
Jack Hennessy, Brookhaven Natural Laboratory,
Upton, New York:
1 asked this question earlier today of Mr.
Apgar; 1 didn't feel it was completely answered. If
you collected the leachate from the cells, would
you describe what treatment methods you would
use to neutralize it or to make the leachate non-
polluting so it could be discarded?
Michael Apgar, Roy F. Weston, Inc., West Chester,
Pennsylvania:
I'm not sure that this is my field of expertise,
but the materials in the leachate include organics
which have to be oxidized and this could be done
by aeration and raising the pH. So, lime treatment
and spraying or something like that ought to be
able to help it. Then you've got high salt content,
and I'm not exactly sure what you could do about
that except dilute it—that is why 1 suggested that
an acceptable way to get rid of this stuff might be
to put it into a municipal sewer system. I'm not
sure if that is being done anywhere right now, but
a lot of people have been talking about it. 1 know
that there are at least one and probably two sites;
but, I know of one in operation in Bucks County,
Pennsylvania, where leachate is collected and
treated. But this is a very expensive process because
you're not through treating the leachate when you
are through utilizing the site for waste disposal.
That is, once you're done putting refuse somewhere
and you've got a leachate collection and treatment
system, you've got to keep operating that treat-
ment system.
The regulations in Pennsylvania have now
been made stiff enough so that in some parts of
the State permits won't be granted to operate a
disposal site unless you go to collection and treat-
ment. So, as far as 1 know these two operations in
the southeastern part of the State of Pennsylvania
are the only two that are operating legally now.
Jack Hennessy:
Could you mention any areas that are actually
collecting leachate and treating it?
Michael Apgar:
Yes, the Warner Co. is the name of one in
Bucks County, Pa.; I have the address somewhere
but I haven't visited their site myself.
Russell Stein, Ohio Division of Water, Columbus:
We are just getting into landfill monitoring in
Ohio, but I know of one case up near Cleveland, a
suburban area, a town known as Painesville up on
Lake Erie, where they are collecting leachate from
a landfill through underdrains which is going into a
sanitary sewer and being treated by the City of
Cleveland Treatment Plant. Other than that, there
is another landfill in one of the counties in Ohio
in which they collect leachate and simply retain it
in an oxidation pond before it bleeds out into the
nearby stream, which does a little bit of good, but
not very much.
I think one of our problems is this idea of
whose responsibility it is to treat a leachate. You
always have this inevitable time lag in a landfill,
particularly a small county landfill, where you may
have four or five years of active use in this landfill.
Five years after that you may have a leachate
problem develop and in the meantime the landfill
is closed up. Who is impelled to go back and build a
treatment plant? Or better still, if treatment exists,
and the landfill operator is operating the treatment
plant, what happens to the treatment plant and
what happens to the leachate when they finish the
landfill operation?
Michael Apgar;
Well, I don't think anybody has reached the
point where they have stopped operating a landfill
that is operating with a treatment system now.
Russell Stein:
I could give you an example of this. Here in
Ohio we are faced with one situation where we
have a landfill up near Cleveland which has a really
nasty leachate problem. It is not causing any
particular ground-water problem because it is in an
area served by city water, but it's causing a very
bad stream pollution problem. Now, all of the local
residents in this area are trying to get an injunction
against the operator to shut this down. The State
people are trying to impel this landfill operator to
collect and treat the leachate. But our feeling is
this, if they get an injunction against this man and
121
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permanently close this landfill down, there is just
nobody available to go in there later and try to
correct a very serious pollution problem, unless it
would be the State.
Michael Apgar:
This is why in a lot of cases the State might
have the authority to do something about a par-
ticular site. I know this is the case in Pennsylvania,
but they are reluctant to close the operation down
because either a private contractor or the munici-
pality itself is running the landfill and by closing
them down, even if it is not being properly
operated, the operator just moves to another site
and the area that was a problem remains a problem.
Everybody has moved away and it just sits there
and it is a sewer.
Roy Williams, University of Idaho, Moscow:
We have an easy way to solve the problem in
Idaho. The operator in one case, or the only case
that has come to court was simply given an order
by the judge to do a number of things before he
left the site; and if he didn't do that, he would be
in contempt of court. It took care of the matter.
Michael Apgar:
Yes, but in a lot of these situations it is an
expensive proposition to correct any damage or
potential damage that's already built into the site.
And you can't very well tell a small operator to
either dig up the refuse or collect the leachate and
treat it or something like that. And in some cases, I
think there is another way of getting at this, and
that is to shift responsibility back to the people
that generated the leachate in the first place.
Is anybody here from Illinois? I understood
somebody to say that the liability could be traced
back to the people that were putting the material
into the site if it could be proven it was their
material, even though they said goodbye to it when
they gave it to a private contractor or to the local
municipal hauler at their generation point and let
h>m take it somewhere. I'm not sure if that's true
but that is what I heard.
Jack W. Keeley:
What is objectionable about having built into
a contract at the outset that these matters be taken
care of in whatever means is appropriate?
Michael Apgar:
That's a good idea, but I don't think most
States are to that point yet.
Warren Hofstra, U. S. Geological Survey, Denver,
Colorado:
One thing that occurs to me is that if a State
or even a Federal agency is in the position of giving
a permit, they can make certain requirements on a
thing that has a relatively limited life, say a landfill
that will only last 10 or 15 years. It seems to me it
would be in order for the governing body to require
piping the leachate to a permanent facility, such as
a municipal sewer. And, if the site was finally filled
or finally used, it would seem reasonable to me that
the governing agency—in this case the city or the
State, or whoever had it would at that time take
over maintenance of the thing as a public health
hazard. The other thing would be not to allow any
of these things unless they were run by a munici-
pality.
Jack W. Keeley.
Perhaps we are talking about three separate
problems. When a landfill is in existence, the permit
to construct this facility was based on certain
existing local or State legislations. If we get worried
about the things and the State or the community
passes legislation with a measure of control, we are
dealing with private or municipal enterprises, which
I think legally are probably a little different. If it is
a municipal enterprise, the State agency can simply
say cease and desist. If it is a private individual, the
operator, probably a corporation if he had any
sense, could take bankruptcy, you see. Then who is
responsible? Now these are questions that are
pretty well established over the country. These then
would fall back on the State or the municipality.
Can you pass an ex post facto law when dealing
with private enterprise? I don't think you can. The
State can issue a cease and desist order but the
operator can take bankruptcy. Is he then responsi-
ble? My point is to open up or maybe guide this
discussion along these lines. Does anyone have any
comment on the legality?
Roy Williams:
The bankruptcy part is obviously not in the
realm of what I was talking about earlier, but let's
say that a municipality in Idaho contracts the
operation of a landfill to an individual and he isn't
bankrupt. I can't see where there would be any
problem with writing any restrictions on the condi-
tion he must leave the site in when he finishes.
Jack W. Keeley:
You're talking about before the fact though.
Roy Williams:
Yes, that's the way we operate them.
Jack W. Keeley:
That's a different ball game. That is clear-cut.
Roy Williams:
Maybe the solution should be operating land-
fills on a contract basis.
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Paul Plummer, Miami Conservancy District, Dayton,
Ohio:
On the last statement, all you have to do is
look at the strip mine operators to see what effects
you are likely to have and the type of reclamation
proceedings you're likely to get. You know, the
law says now that they must clean up the site and
reclaim the site. Go look at some of these reclaimed
sites. I think we as geologists, hydrologists,etc. are
going to have to make recommendations to the
legal and political people so that some of these
problems can be solved by legal means. How we
arrive at these recommendations, 1 don't know.
Truman Bennett, Ranney Water Systems, Colum-
bus, Ohio:
I'm sure that in an individual case the con-
tractual relationship would be very successful, but
as a political fact it would become something you
couldn't live with after awhile because you won't
negotiate in the same way with every contractor.
Then everyone who has an axe to grind has a place
to grind it, and the sanitary landfill then is going to
become a political question instead of the techno-
logical question which it should be. Maybe what
we are talking about is the possibility of operating
sanitary-landfills as public utilities.
Michael Apgar:
What we are looking at here, as mentioned in
Dr. Zanoni's paper this morning, is that landfills
haven't yet been fatal to anybody. So, while we're
concerned about ground-w'ater pollution, the alter-
native is one that results in letting refuse pile up in
the streets which is a much worse alternative than
letting them go ahead and pollute ground water. I
think that laws are coming and pressure is coming
that will force operators to clean landfills up, to
take care of them in the same way that strip mine
laws are now taking effect. There are still some
mines that look like they are in bad shape, but
there is a terrific improvement in others. That
wouldn't have been the case several years ago with-
out the new laws.
Robert Kaufman, Desert Research Institute, Las
Vegas, Nevada:
I'm supposed to be taking the place of Dr.
Zanoni. The contractual part of engaging in landfill
garbage disposal can go three ways—municipal,
municipal supervision with private contractor, or
straight private contractor. In any case, except
perhaps the first, it is a matter of contractual law.
To guarantee performance as in any other business
operation where there's a risk factor or competence
factor, there is simply a matter of posting a per-
formance bond. The most serious problems from
solid waste are the future operations. Last time I
heard it, Utah was not concentrating on the exist-
ing industries and polluters, but rather on control-
ling future polluters or potential polluters. They are
interested in future industry and how it is tooling
up with respect to air, land and water degradation
as a by-product of its operation. So, if we look at
sanitary landfills and the well documented mount-
ing refuse volumes, the object is not so much to
attack with an ex post facto law which legally
probably wouldn't hold up, as it is to go after the
coming problem.
And this is simply a matter of when negotia-
tions come up for contracts for refuse hauling, the
contracts should be written with some meat in
them. I know in the Las Vegas area the contract
from the city and one carrier who has had the
contract for over 10 years and wants to negotiate
for another 10 years simply calls for hauling the
refuse out of the city. Whether he piles it or burns
it—the city says that's the county's problem. This
is childish. Each is trying to pass it on to the other.
So really it is a matter of strong contracts with
performance bonds for any dereliction or abroga-
tion of the contract. Now as far as going after
existing landfills and polluters, 1 don't think you
can tell them to stop. That's ridiculous. New York
City didn't stop for too long; no city has. It's a
matter of putting a compliance schedule into any
hearing's policy, most commonly with air polluters
and big water polluters. They're still polluting, but
six months from now they'll be polluting less, and
still less a year and a half from now. This is a
reasonable way to go after it. If a contractor feels
he can no longer provide that kind of service and
put in this special equipment, then the contract has
to be renegotiated. It is a bilateral contract. The
contract conditions are changed if the State or city
says you now have to put in this or that for control
or diversion works. So what it really comes down
to, when you want service in solid waste disposal
and a first-class refuse disposal operation, you are
going to pay for it. The best way to get into a bad
contract is to not have competition when the specs
are drawn up and the contracts bid on. The worst
condition is to have one bidder, because he names
his prices and the city feels they are stuck with it.
But there is nothing more secure than a municipal
contract and especially with refuse. It is going to be
there always and it is increasing.
So my feeling is that we know enough now to
operate landfills. It is really a matter of legal and
legislative controls and just good, plain contract
law to get it to operate. If we are working with
details of one site here vs. another site there, I
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firmly believe that there is enough known now to
design a landfill to operate with certain pollution
outputs. And I don't think that digging up the old
skeletons to stop landfills is really the heart of the
problem. The future is the heart of the problem.
Russell Stein:
I'd like to comment on our situation in Ohio
because I think we have a real problem in solid
waste because it is a pretty populous State. I work
primarily in evaluating new landfill sites which I
don't think is really that much of a problem now;
we have these under control. One is required to
obtain a permit from the State before one can
operate a landfill. So we have some control here.
The problem is this in Ohio—the permit system for
landfills was effective July 1, 1970. Prior to that
time we had about 600 open dumps and a few
landfills. Now what have they done since then?
Many of these open dumps have been shut down
and there have been about 200 permits issued for
new acceptable sanitary landfills, yet there are
about 350 open dumps still operating because
they can't come up with a site which is suitable for
the technical people in the State. They will choose
a site, and we say, no this isn't acceptable. So, con-
sequently they continue to use their open dump.
We have a time lag here of over a year. I think our
pollution problems go back to a lot of these old
dumps in which the local people applied for a
permit to convert an old dump to a sanitary landfill
because it was the only or maybe it was the best
site they had in an area.
It still boils down to economics, and you
simply can't impel people to pay much more for
solid waste disposal than they are now because
they just won't accept it. They'll take it out and
dump it along the highways like they used to do,
and probably still do in a lot of areas. I think this is
one of our main problems. It seems like we techni-
cal people in the State set our standards pretty high
for selecting a suitable waste disposal site, and I
found myself kind of giving in a little bit from
this respect because there just aren't this many
sites available; or if they are available, the people
just won't accept the cost of trying to develop the
sites.
Richard Pearl, Colorado Geological Survey, Denver:
This comment pertains to Wyoming where a
city had the advantage of expert hydrologic advice,
but disregarded it and located their dump right
over their city water field. The U.S.G.S. office in
Cheyenne pointed this out to them and did almost
everything but go to court. The city fathers felt it
was better to face future water pollution than to
face air pollution because the other site, the dump,
was up-wind from the city of Cheyenne; and there
is some burning at this dump, so they chose to put
it over their well field. The question I want to ask
Bob Kaufman is how are you really going to get
around it when a city ignores expert advice? There
is no State control up there.
And then I want to ask Mike Apgar a question.
The water level is about 150 feet or deeper up there
in this arid to semiarid environment. You didn't
show conclusive proof that your leachate was
reaching the water table this morning. At least that
was my interpretation of it. Is there a chance that
this leachate is going to get down there or is it go-
ing to be purified enough so that it isn't going to
bother the water quality if it does get down there?
Robert Kaufman:
Well, we have a democracy and for all its bad
and good points, if an issue comes up, I think the
best route is a public hearing where there are expert
witnesses, not paid experts, not out-of-town ex-
perts, but groups like the League of Women Voters,
or various environmental groups. There was a de-
velopment in Las Vegas recently where over a
million dollars was spent on site evaluation, just
evaluation, and the return on the investment was
reported to be somewhere in the order of 100
million dollars. Now the only objections put before
the State were put forth by unpaid, nonprofit
interest groups who were in violent opposition to
changing water quality standards in the Colorado
River, and other variances that this firm wanted
against county ordinances regulating the develop-
ment. The point I make is that an informed public
which may consist of just interest groups can bring
out a lot of these sticky little issues like putting a
dump over a well field.
Now, looking at the other side of the coin it
might not be a bad idea. George Hughes has one
landfill site in northeastern Illinois on the banks of
the DuPage River, I believe it is, and he figures
there is something like a maximum of 5 or 10
milligrams per liter increase in chlorides from that
landfill site. Now there isn't a person in the world
that can taste 10 milligrams per liter of chloride.
I'm not making an excuse for it, but you could put
this over a giant well field and the landfill is dump-
ing out maybe 20,000 gallons a day and you are
pumping 5 million gallons a day out of the well
held. It's inconsequential.
Landfilling is a community service. We have
buses outside now dumping diesel fumes and we are
accepting the service. George Hughes has proved in
Illinois that 90 cents out of every dollar is spent on
transportation. For every solid waste dollar, trans-
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portation eats up most of it. Either go to rail haul
and get the economies of mass transfer, or pick a
site close in, and the money saved can be used to
divert the leachate.
These are the sorts of issues and the questions
that have to be generated for each issue, either on
the part of the State or with local groups. I think
the worst cases develop when things are done in
closed meetings and an under the table contract is
let for 10 years of service which has no concern for
these matters. And I think in the interim, before
we have State agencies that are well funded to
inspect and regulate and so forth, that we have to
depend on the local semipolitical groups and action
groups to work with. I don't see any alternative
because city and municipal leadership is going to
adopt the least cost solution in most cases, because
nobody likes increased taxes and you don't get
voted back into office with increased taxes. '
We have \ State law in Nevada now and the
only reason k was passed is because the agricultural
interests were exempted; they contribute a major
part of the solid waste in the northern part of the
State. They said if you want support for this bill,
exempt agricultural waste. It was a limited victory
because the legislature only meets every two years;
and if we wanted any solid waste legislation, it had
to be without the agricultural people included.
Maybe in the next two years we will pick them up.
Michael Apgar:
I think that Bob already answered my part of
your question—that you can't really be sure in this
type of setting that the landfill is going to have any
more than minimal effect on the ground-water
quality. In a semiarid environment with an aquifer
150 feet below the surface, you probably won't
even notice the effect of the landfill up there, but
I'm guessing. I wouldn't want to say that for sure
without looking at the site a little more and know-
ing a little more about it. If they want to go ahead
and do it that way, it doesn't sound that bad.
Roy Williams:
Mike, I would like to comment a little further
on the problem of saturation. Your paper is a super
important paper because it is one of the few that
has reported on the water quality in the un-
saturated zone. I'm a little concerned that it may
not be unsaturated because the 200 foot water
level doesn't mean the water levels are 200 feet,
and the absence of nitrates suggests anaerobic con-
ditions which may suggest saturation. I would like
to hear comments on your evidence for unsatura-
tion.
Michael Apgar:
Generally there aren't any major perched
systems between the land surface and the water
table, except that we do have evidence that water is
standing in one of the refuse cells in the lower
topographic position. Sometimes there is water
ponded in the upper refuse cell because after a
certain amount of decomposition, the floor of
these refuse trenches becomes impermeable enough
to hold water. Soil moisture contents of samples
that we cored beneath these refuse cells only range
from 10 to 20 percent, and there is nobody in the
area that has a hole in the ground that has water
standing in it anywhere between 200 feet and the
surface.
Don Langmuir, Pennsylvania State University,
University Park:
We have a water table map which was not
shown today which indicates the general water
levels throughout the whole area and they are
around 230 feet or so with very little variance. It is
quite a flat water table. So as Mike said, there could
be locally some saturation when the soils are
appropriate for this, but in general this is not the
case.
Jack W. Keeley:
Let me interrupt just a moment and ask a
question. Can we necessarily assume that because
a zone is unsaturated, it is aerobic?
Don Langmuir:
Whether the zone is aerobic or not is really
going to be a function of rates. It is a function of
the rate of depletion of the oxygen by organic
material versus the rate of its introduction into the
system by movement through a soil or in fresh
soil moisture. In most cases if there is much BOD,
say 10 milligrams per liter or so, and you are
talking about a soil, the depletion rate is faster than
the rate of introduction and anaerobic conditions
will exist because the rates are favoring this. We
found in our system, for soils that are heterog-
eneous, aerobic zones adjacent to anaerobic zones
because of the nature of the soil in the system. So
it isn't a simple matter.
Roy Williams:
For future studies, I think it would be advisa-
ble to put in a few well points just 10 dispel all
doubts that you really are dealing with unsaturated
conditions. If somebody comes along two years
from now and wants to use your data in a decision,
there will be absolutely no doubt.
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Michael Apgar:
We have a similar study involving a program of
spray irrigation of treating secondary waste effluent
from the University Sewage Treatment Plant on a
game land area. We are dealing with the same type
of soil, same underlying bedrock, and same water
table conditions at depths between 200 and 400
feet below the surface. Pan lysimeters were installed
in the soil, and they just couldn't get samples in
them. That is why we are using suction lysimeters.
Now there are pan lysimeters in use in the spray
irrigation study, but they only collect moisture
after the soil is essentially saturated by heavy spray-
ing directly over where the lysimeters are located.
I am not saying that there aren't positions in the
soil, especially after periods of heavy recharge, that
aren't saturated. There may be small perched sys-
tems on clay lenses and unweathered bedrock
ledges and things of this nature, but in general
you don't get much water, if you put a hole in the
ground, you're not going to get much out of it.
You can be fortunate enough to end any hole or
piezometer on an impervious ledge and have water
standing down there on a regular basis. But it just
depends on where you locate the end of this thing.
And to get samples we went to suction lysimeters.
Jeffrey Sutherland, Williams and Works Engineers,
Grand Rapids, Michigan:
I'd like to ask Don Langmuir and Mike Apgar
a question related to their paper this morning. I'm
unsure of how you are able to determine that
leachate from the upper refuse cell contaminated
the ground underneath the lower one. It seemed to
have had a rather shallow topographic slope be-
tween the two, and no perched water. Therefore it
doesn't seem to me that much of a route for hori-
zontal transport was present. Maybe I'm missing
something here.
Michael Apgar:
I'm sorry if 1 gave you that impression. The
figure I used in the talk was a plot of depth versus
conductance beneath the cells. But the instru-
mented cells in question are on opposite sides of
this dry stream bed and so we're not saying that
leachate from one actually goes down and reaches
the sampling points beneath the other. But rather
there are a series of cells all along both slopes and
the cells located above the valley bottom cell on
this side of the stream bed may in fact move down
and make any soil moisture contamination problem
beneath the lower cell look worse than it might be
if it received a contribution only from that cell.
Jeffrey Sutherland:
So there is enough of a stratification in these
soils or sediments to get some lateral movement
from one cell to the next?
Michael Apgar:
Well, I wouldn't say it is a very regular
stratification. The soil bottoms slope downhill and
the topography is going that way and there is an
outcrop located about 700 feet away in which the
dip of bedrock is. in the same direction as the slope
here. But of course the soil itself, even though it is
a residual soil with some lenses, layers, and regulari-
ties, is fraught with all kinds of collapse features
and mix-ups that developed as the rock weathered.
So it's not a simple situation where you can put
things in at the top and let them float downhill.
Jeffrey Sutherland:
1 have another question. I'm new in the land-
fill site evaluation business myself. In Michigan I'm
acquainted with the regulations established by the
Michigan Geological Survey which is one of the
two State regulating agencies. We have a lot of
apparently homogeneous dry sand terrain without
much in the way of low permeability layers like
clay to afford some kind of a natural collecting
substrate for gathering leachate into some kind of a
treatment system. I wonder if anyone has any
experience with bentonite or any kind of liner that
can be harrowed or disked into sand to minimize or
perhaps eliminate any significant liquid leachate
percolation?
Paul Goydan, Koppers Co., Inc., Pittsburgh,
Pennsylvania:
Of course today many of your State agencies
require bentonite as the lining to use in lagoons
and other types of installations where you expect
contamination of ground water. Bentonite may be
purchased from a number of agencies. Wyoming
bentonite, which is generally regarded as one of
the best bentonites as far as being impervious, is
pretty much a sodium mommorillonite clay. You
often get involved in Arkansas bentonite and some
of these other States that claim to have bentonite.
You are dealing then with a mixture of clays; and
although there may be a certain degree of mont-
morillonite this is often calcium montmorillonite
which is not as impermeable. Some research has
been going on as far as taking a clay such as a
calcium-rich montmorillonite with a mixture of
kaolinite and chlorite or whatever else you may
have and impregnate this with salt water supplying
the sodium. This can be used as an impermeable
type bed; and, of course, through time, your
lattice structures in the clays will expand and
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improve your barrier. Did that answer your ques-
tion or were you talking about absorption rather
than sealing?
Jeffrey Sutherland:
I was asking whether or not the properties of
sodium bentonite or sodium montmorillonite actu-
ally do provide a maximum seal to minimize or
absolutely prevent the formation of leachates.
Paul Goydan:
I've found a statement that 1(T7 to 1(T9 centi-
meters per second permeability is expected. This is
the permeability range of a good Wyoming benton-
ite. This is considered "virtually" impermeable; and
without going to some cementing material or
manufactured material this is pretty good; and
with an expanding lattice, with water, you don't
have too much to worry about.
Don Langmuir:
Might you than have to worry about the
nature of the leachate itself altering the character-
istics of the montmorillonite if it is a calcium or
magnesium leachate? Ion exchange can alter the
permeability of your liner if the leachate-liner
combination is not compatible.
Joe Miller, New Jersey Geol. Survey, Princeton:
We have a similar problem. I was talking with
Mike about it. The County of Camden is going to
make a county sanitary landfill on 450 acres in an
area where it is 27 feet to ground water. We are
trying to figure out what the heck we can put
down to keep the stuff from going down. So far I
don't know whether your bentonites are going to
stand up, because we don't know what they are
going to put in this landfill. Any ideas on some-
thing like this? What about putting an impervious
layer with perforated pipes and then transporting
the leachate back into a municipal system. Is this
acceptable?
Grover Emrich, A. W. Martin Associates, Inc., King
of Prussia, Pennsyfvania:
This raises a very interesting question because
we are now completing the engineering and con-
struction of a limestone quarry that will be turned
into a sanitary landfill. The quarry had about 30
feet of water in the bottom of it. Submersible
pumps have been installed to lower the water
table and maintain it below the bottom of the
quarry. The quarry is being filled with rock and
earth to bring it up about 15 feet above the water
level and then an impermeable liner will be put in.
We are disking soil cement in the upper foot of the
soil and then we will put on a specially prepared
tar pitch material that will be sprayed across the
bottom of the quarry. It will be sloped to a central
sump from which the leachate will be pumped to
the surface; it will be treated and then discharged
into a nearby sanitary sewer. This quarry will be
reported at the AAAS meeting in Philadelphia this
winter. If any of you are interested in details I'll
be here for the rest of this evening and tomorrow
morning.
The quarry should be in operation toward the
end of September. Unfortunately Murphy's Law
has come into play and we are now 9 months be-
hind in completion of the quarry. Murphy's Law
says everything that can go wrong will go wrong,
which included an operating engineer's strike for
three months. Power lines were not there and it
took three months to get them in and things like
that. We are also doing the same thing for another
quarry which is a cement quarry north of Allen-
town, Pennsylvania. Cement rock up there is
fantastically tight. All the people use cisterns, not
because their water is polluted but because they
don't have any water in their wells. We will go
through the same sequence of dewatering the
quarry which has about 5 feet of water in it, build-
ing the quarry floor up, putting in the liner,
collecting the leachate, treating it and then dis-
charging it to a sanitary sewer. Another landfill is
in operation in southeastern Pennsylvania with a
liner in it. This has been in operation since last
October. They also will be collecting leachate and
treating it. In that case they will discharge directly
to the Delaware River Estuary. The technology I
think has reached the point where we can hy-
draulically isolate landfill leachate from the ground
water, treat the leachate and handle it just like
another industrial waste.
There is a possibility of putting a. cover on top
of the landfill. This has been tried many times. I've
worked with Pennsylvania regulatory agency setting
up the regulations and doing all the hydrogeologic
investigations. In fact, this Penn State study was
something that the Pennsylvania Dept. of Health
initiated by going to Penn State. There was another
one we initiated at Drexel University. My staff and
I have looked at 100 or 150 landfills designed
specifically in an attempt to put clay covers over
them to keep the water out and no leachate from
forming. They have been notoriously unsuccessful-
I'd say 100%. There are several reasons for this—the
decomposition of organics and other materials in
the refuse will produce a liquid. Of course if you
have no moisture in it, you might delay this. In
most cases they use a clay cover which is im-
properly installed. It is wet, it swells, water runs
off, then it dries off and it cracks. I've seen some
cracks that are 2 or 3 inches wide and many feet
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long so that the next time it rains all the water runs
down the cracks. There is very little that runs off.
Another problem you have is that even with an
impermeable clay layer on top you still have your
gas generation. Some of this gas may move laterally;
unfortunately, it will build up pressure and will
crack your liner. I cannot recommend the idea of
making it impossible for leachate to form. I've yet
to see it work; and, unfortunately, it has been
sold. Maybe somebody else has seen it work. I'd be
interested in anybody that could fill me in on this.
Ted Hudson, Radian Corporation, Austin, Texas:
Has anyone done any work on the equilibria
that are set up between the absorption of the vari-
ous organic compounds that are going to be pro-
duced in the leachate and what effect this has on
the permeability of a clay liner? What are the
equilibria that are set up and what does this do to
the permeability of the clay liners that people are
talking about using? Which is preferentially ab-
sorbed, the organic, the sodium, or the inorganics
that are in the landfill?
Don Langmuir:
To my knowledge, there has been no detailed
study of sorption of the organics. The charged
species you would primarily be concerned with are
going to be anions, so it's anion exchange. Most
clays are cation exchangers so that they're not
going to play an important role. It is more likely to
be a factor of the accumulation of these materials
on trench bottoms. Mike can tell you a little about
this. There is a physical clogging effect that these
organics will have on clay liners, where leachate is
trying to flow down through the bottom of the
trench. You'll get slimes and gels which prevent the
flow of the leachate, which will decrease the per-
meability. Since in most cases cation exchange is
predominant, the inorganic cations will be the
favored species in exchange. The sodium, calcium
type thing will affect the permeability, of course.
Ted Hudson:
Mike, can you refresh my memory on the pH
of some of these leachates?
Michael Apgar:
The pH in leachate ranged from about 5 to
6.5 normally. However, in one case where we dis-
solved a cement floor and maybe due to some other
causes, it got as high as 8.0 or 8.5.
Ted Hudson:
I know there is some work on some chromium
oxide absorption on sodium montmorillonite clays
that MacAtee and Shaw did several years ago and
these things are quite strongly absorbed on clays.
128
Also Hawthorne did some work in which he looked
at some positive nitrogen containing organic com-
pounds. They were involved in looking at these
montmorillonites as cracking catalysts for various
operations. Therefore, they are quite strongly ab-
sorbed by these sodium montmorillonite clays.
They did not look at the equilibria that were
established. They were not concerned with it and I
was just wondering if anyone here was.
The other question I have is concerned with
your Eh values. I would like for you or Dr.
Langmuir to elaborate a little more fully on the
oxidation reduction potentials and what value you
placed in these redox potentials in your interpreta-
tion of your data.
Michael Apgar:
I don't think anybody that has been studying
leachates from landfills has made the jump to try-
ing to figure out any kind of equilibria absorption
relationships between organics and soils because
most people don't even bother with identifying the
organics. I can remember reading one study where
this was done and we're thinking of getting into
this at Penn State, but ground-water geologists with
a chemistry background are generally inorganic
chemically oriented. It is kind of a sticky business,
and not much fun either, to collect this highly
organic contaminated slop and take it in the lab
and play with it. To fool with the organics is some-
thing that hasn't appealed to many people yet. I
don't even know if they have considered doing it.
I can remember a study in West Virginia where
column experiments were carried out. Leachates
were put into concrete cylinders and water was
leached through this refuse and collected from the
bottom at a spigot or drain and then the organics
were identified or separated chromatographically
and identified as being mostly acetic or butyric
acids. As for carrying this further, I don't know.
I'd start answering the second half of your
question but I see Dr. Langmuir is getting very-
excited about doing this so I'll let him take it.
Don Langmuir:
I was going to comment a little on what you
were just talking about, Mike. This organic stuff in
leachates is so complicated that you can find any-
thing you like in there. You'll find what you look
for. There are not just organic acids. There are
carbohydrates, fats, proteins, you name it. You
could spend a lifetime trying to discover which
things were there. And that's why it's so difficult to
figure out what anything is doing in terms of its
effect on, for example, trace metal transport. This
kind of thing we're going to try and get into in the
next few years.
-------
I'd like to talk about the Eh thing for a min-
ute—as I said this morning in an answer, we worried
about this quite a bit. If I can get back to the be-
ginning on Eh, it might be useful. An Eh measure-
ment is going to be a measurement of a zero cur-
rent flow at a particular potential. There is no
current flow and you find that potential at which
this current will not flow using a platinum electrode
and a reference electrode. For this to occur there
are two voltages involved; there's an oxidation and
a reduction voltage potential. You need reactions
which are reversible to get a meaningful Eh meas-
urement and this can be an awful problem if you've
got a whole series of different species, some of
which can be reduced but can't be oxidized, and
conversely.
Now this is what a leachate is in many cases.
You've got nitrogen species which can be oxidized,
you've got sulphur species which may be or may
not, and you've got a variety of reactions which are
not reversible. But there is a way out of this. In
many cases a leachate is very, very rich in iron, and
the total iron values Mike was talking about are
chiefly ferrous iron. It has been found that the
reaction between ferrous iron and ferric hydroxide
is ubiquitous in the leachate, because of the iron in
the soil. This reaction is reversible and it goes fast.
There is a measurable potential from ferrous iron
to ferric hydroxide and back. And this is what
seems to be controlling our measurements. It makes
good thermodynamic sense in spite of the mess a
leachate is to make this assumption. We can com-
pute things about this reaction from the measure-
ments we make of pH, Eh, of our assumed solubil-
ities for the oxides, and it works. We didn't show
the plots today. We have plots of measurements in
the leachate and they parallel right on boundaries,
ferric hydroxide, ferrous iron, if you know what
those look like on an Eh, pH diagram. They make
pretty good sense. There's one up there Mike's
waving if anybody wants to look at it later on. So
we don't want to take these numbers and say they
are thermodynamics in the pure sense, but they
work reasonably well. For example, they seem to
tell us that we will not have nitrate when we're way
out of the nitrate field in that diagram—for example
when we're way down in the ammonia field. They
give us a pretty good semiquantitative view of what
is in there and what to expect.
Paul Goydan:
Did you look at the reduced and oxidized
species of nitrogen? Were they able to give you
similar type indications of the Eh, and also of the
oxidized and reduced sulphur species?
Don Langmuir:
We didn't see oxidized species of nitrogen
except at the very beginning of the study when
anaerobic conditions were setting in, and at that
time I don't think we had Eh measurements. So
most of the study conditions were anaerobic
enough so that we had no nitrate or nitrite.
We don't know exactly what the organics are
but there is a tremendous literature now of organic
interactions, as you know, with clays; and at Penn
State, George Brindley has done a great deal of
work of this kind. Of course, the gap between
knowing what the organic is in a pure system and
what it really is in leachate is a long way.
Ted Hudson:
My only thought here, as Dr. Langmuir has
pointed out, is he doesn't really have a pure
thermodynamic ferrous, ferric system in which he
makes his Eh measurement or his redox potential
measurements, which is fine. It doesn't really mat-
ter because he gets the information he is interested
in. I would not like to trudge out there and collect
these samples either. Nor would I like to use them
in the laboratory. But if one made model com-
pounds and then made these studies you would
have some basic understanding of the competitive
nature of the reactions between the cationic
organic materials and the cationic inorganic ma-
terials. This is the point I was trying to make.
Don Langmuir:
In the future, what we plan to do is look at
some of the organics as they move down through
the soil—look at the BOD and break it down in
terms of certain types of organic chemical species—
and see how they vary in amount and type with
depth. This should give us some kind of an idea of
what is going on. We'll relate this to trace metals
and to absorption if we can.
Jack W. Keeley:
I'm going to get in trouble here. We've talked
about how we like to go out and measure pH and
chloride and sulphide, etc. I asked this question
this morning and I think it's one that we very often
ignore, probably because we are afraid of it or we
don't know how to handle it. I can at least imagine
situations of zero BOD, zero chlorides, zero sul-
phates, zero this, that and the other, and we have
some highly carcinogistic materials, or their degra-
dation products, that totally escape us. I know
DDT degrades anaerobically. We don't know what
the degradation products are. They may be more
soluble. They may be more toxic. The world is full
now of antibiotics and estrogens, of birth control
pills, and diethylstilbesterol which we feed to
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animals. I think we tend to completely overlook
this field because it's difficult. Do we have the
latitude to be that pious to simplicity?
Ted Hudson:
Also overlooked are things that are precursors
to carcinogens. There are many compounds that
react with other things that then create a carcino-
gistic compound. So I call these, or lump these,
into what is called a precursor to a carcinogen. An
example of this is nitrite. If nitrate is present, you
have the possibility of nitrite. Nitrite can react with
various and sundry compounds to form nitrosa-
mines which are known as carcinogenic compounds.
I just throw this out to say that the subject matter
is even more complicated in that you have also
these precursors to carcinogens.
Jack W. Keeley:
Then we throw all of the degradation products
of all of these together and we've got a mess. Does
anyone wish to comment on this before we move
to other questions?
Paul Plummer:
We are probably sampling what we can meas-
ure. A lot of these things, even sampling for trace
metals, gets extremely complicated. And once you
get outside of the laboratory into a practical field
situation, it becomes almost impossible to get what
you consider to be a valid measurement of some of
these substances. There is room for a lot of work
on sampling techniques and methods for measuring
these many trace elements which we are intro-
ducing into the system.
Jack W. Keeley:
I can't accept that because something is diffi-
cult we in the ground-water industry can ignore it.
I have been in the field a good deal myself. There
are techniques available and there are possibilities
to develop new techniques. What I am suggesting is
that we in the industry should be forward thinking
enough to start getting into these. I realize you
can't go out in the field with a bucket and a rope
and concentrate samples to where we can shoot
them into a gas chromatograph and look at these
things. I'm suggesting here that we start looking at
them. Let's lead the surface boys a little bit.
Don Langmuir:
There are a couple of ways we can go at this
whole thing. From major species we have various
defenses; for example, if we have charged species to
see if we've got everything in there, we measure the
total anions and the total cations. They've got to
equal each other. If something is in there we don't
know about, we'll find out that way. So insofar as
we have major species over 2, 3 or 4 percent,
perhaps, we can spot them often this way. This is
the inorganic charged species. We've got total
dissolved solids and we've got conductance. We've
got a variety of total measurements as a means of
getting at the summations of other species in the
system. Beyond that point, when it comes to trace
species, we've got to go to other techniques such as
spectrophotometric scanning or neutron activation.
There are various new devices and new ways of
getting at a variety of things that may be in there.
We ought to develop more of these techniques; for
example, scanning for the trace species. That's the
big problem, as you say. What is there in the trace
amount which can hurt us? That's where we need
the most advancement, the most research.
Bob Kaufman:
I don't want to drag down the scientific level
of our preparation for Dr. Greenfield. I'm not
arguing with any research goals. The point I'm
making though is we have to service a community
problem. NWWA has come up with well drilling
specs, completion specs and so forth; maybe they
are not the best but they are the best the NWWA
could come up with at this time. The point is that
there has been enough work done on the hydro-
geology and chemistry of landfills that we can
provide a lot of service and advisement to practical-
ly any major problem in the country. And I dare
say if we had an interchange like this tonight in
front of a community of concerned citizens at a
local hearing, these people would be very astray as
to which course of action to take.
I'm not arguing with anything you've said,
Don, or the gentleman from Texas; but I think as
others have pointed out today, Al Zanoni for one,
the garbage trucks are coming down the street.
Now we can bury it or we can burn it. Those are
the only two alternatives we have, and there's
enough knowledge to provide a reasonable factor
of safety for burial, the sanitary landfill. I can't
overemphasize that enough because to go and say
we need more study, we've got to find this out,
we've got to find that out, is not doing a service
now. It may be in 10 or 15 years but it's not doing
it now. I don't see why we should go into multi-
million dollar landfilling operations over a 20 or 30
year time frame with a $500 site investigation. The
techniques are available to design landfills to meet
certain performance criteria and when all the other
information comes along later as to exact knowl-
edge, fine. Maybe I'm just a marginal scientist, but
we have a today problem and more study, the data
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of which and conclusions of which are available in
five years, won't meet today's problems.
Warren Hofstra:
One thing that has impressed me a lot is that
people are looking at these things from a very
practical, today standpoint. But I question whether
the water system in the humid crowded portions
of the country will stand the total impact of solid
waste disposal, septic tanks, industrial wastes, and
all of the other things that are going into the water
system. I think that as a practical matter we will
have to develop the best sanitary landfills that we
can for the time being. But I do feel that we are
allowing a five percent change in the water quality
with this landfill. I feel that we are, in the name of
practicality and economy, perhaps overlooking a
more thorough and a more complete control of
solid waste and all waste. Perhaps we are being a
little short sighted considering a tremendous in-
crease in population, and I think we may have to
reclaim these materials.
Bob Kaufman:
I agree, the average site investigation today is
absolutely minimal. 1 don't think we are in dis-
agreement. What I am trying to say is we are not
using the tools that are available. This is the prob-
lem. If a community goes for any kind of a major
capital investment such as landfilling, it's a 10 or
20-year operation in practically every situation. A
town of 250,000 will spend a million dollars a year
in landfilling. Now, a million dollars a year is a
capital investment that should be handled carefully
with long-term goals. For instance, if we put in a
landfill in a human zone, we can control infiltration
to a certain degree. There can be tile systems put
in as the refuse goes. It can be incremented over the
years as the landfill expands. After the infiltration
is reduced, either through control of runoff or
proper vegetative cover or using it with a very tight
asphalt cover for parking lots, we use the tile
systems to collect leachate; and if things still get
out of hand, diversion wells can be put in. We have
talked about dewatering before refuse is put in. We
can lower a water table after it's affected. I don't
see anything wrong with this. An engineer, for all
his skills, plays every bet he can. And when he is in
doubt, he puts in a factor of safety. Geologists
think that they're putting their tail between their
legs if they start talking factors of safety. And yet
geologists should be the last ones to be exact. Who
can say how a bentonite line is going to behave
after 10 years of leachate contact? We can't wait
10 years to find out.
Dick Rhindress, Pennsylvania Dept. of Environ-
mental Resources, Harrisburg :
I am directly involved with our sanitary land-
fill program. I just walked in so I'm not sure what
has been said. But picking up the shreds of the
conversation here, we've tried to tackle this by the
horns and run with it. We agree that there is no
single system. You can come to us with practically
any plan under the sun to run a landfill. Yes, we
have guidelines which say you should run them in
these basic manners. But when it comes to engi-
neering and geology and hydrology, if you've got
some new plan, we'll listen. We're fully open to
anything, whether it's underdrains, lining a quarry
with whatever you want to line it with, putting
down an asphalt layer on flood plain gravels, what-
ever you have to do to collect leachate, or if you
have a good site where there is a reasonable zone of
aeration like Mike's site up at Penn State. We still
feel you can probably get away with the natural
renovation system. The sites are limited but this is
a possibility. We're also open to all the new research
we can get. We've been in on the support of the
Penn State study, and we've had input into the
Drexel study and gotten output. We're in close
contact with the Illinois people and everyone else
that's doing any of this type of work. We take
every little fragment we can get, and we're going to
be a clearing house to help you people around the
State come up with some good sites.
In the idea of site investigations, we have what
we call modular forms. They are forms to be filled
out in great detail on geology, ground water, soils,
engineering plans and so forth. The geology section
of those forms has been written so that only a
geologist can understand it. There's about 17 pages
of geologic data that we require before we'll even
look at your site. So we are at least forcing the
landfills in Pennsylvania, the new ones and the old
ones that have to be upgraded, to come in with one
raft of geologic data before we'll even talk to them.
Jim Urban, Agricultural Research Service, Uni-
versity Park, Pennsylvania:
It seemed to me throughout much of this
discussion this common thread of getting rid of
waste by dilution seems to occur. I wonder if we
might consider a pollution potential somewhat
analogous to a dam. If a dam is close to a city, it
requires a higher degree of site investigation than
one in the middle of a strip mine- area 50 miles
away from the nearest population. What do you do
when you have an area where the ground-water
quality becomes impaired to the point where you
reach, say nitrate nitrogen at 15 ppm? Where do
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you stop your inputs? Do you stop putting in land-
fills at that point? Just where do you draw the line
on inputs? Can you allow these inputs to occur?
Michael Apgar:
I don't think you really know what the impact
on ground-water quality is going to be until you go
ahead and do it. It's just like aquifer modeling
programs right now, or in the development of a
model for any kind of a hydrogeologic system you
want to play with. You really don't know how the
model is doing until you go ahead and do it and
check the results. Once you see that you're con-
taminating water from a landfill in an area, well,
you're contaminating the water. I don't know if
that answers your question or not, but in a lot of
cases you really can't be sure how much con-
tamination you're going to get.
I want to make a comment also on some of
the implications of the Penn State study that we've
been doing. Sure, beneath at least one of the cells
that we're instrumenting we see that the leachate is
not being very effectively renovated as it percolates
down through the soil. It is of horrible quality to
begin with and it seems to be going down to about
50 feet now. But in other settings the leachate is
being effectively aerated and diluted so that really
it is not a problem by 20 or 30 feet. And you have
different things going on within the same site. This
depends on how much water you get in the cell and
what kind of refuse materials you've got there any-
way because it is heterogeneous all over the place;
and, as far as an impact of this landfill on the water
quality immediately beneath the site, there's a de-
terioration in ground-water quality that we feel
confident is due to the landfill. Now, of course, we
only have the one monitor well which is a problem.
In any case, whether or not landfills are going
to affect anybody beyond the landfill at the next
water supply or something like that, I'm pretty sure
that it's not. The next water supply might be for
watering a golf course half a mile away and is
probably not even in the same flow direction. By
the time you get the water that far away it will
probably be mixed up and diluted with other things
so that it's not going to be a big deal. They're not
going to kill anybody further away.
I'd also like to take this opportunity to change
the subject. Here we are out in Colorado and no-
body seems to be very worried about leachates
from mine tailings, when it has already been shown
that such leachates have killed a horse and maybe a
man, even though he doesn't want to know what's
killing him. Whereas leachates from landfills are a
more widespread problem, we haven't really dem-
onstrated that they are of a toxic nature. We're just
talking about increasing the solids' content of water
or making the water kind of smelly, and you can
get around this. If leachates foul up your water
supply to the point where people won't drink it
anymore, they can always treat it and this will
cost them money on that end rather than the other
end. And that's not a good thing. I think we ought
to give Leland Mink a chance to talk a little more
about his studies with the metals from the mine
dumps.
John Rold, Colorado Geological Survey, Denver:
There's been a lot more concern about the
problems of leachates from mine tailings than is
apparent on the surface. Yet I think we have less
problems from mine tailings here in Colorado than
we have from sanitary landfills. Zanoni's paper
today gave the impression that sanitary landfills
were not really much of a problem in general. The
same comment has been made again tonight. When
I was down at the office this evening doing some
work, I saw a news release from U.S.G.S. which
was quite interesting in light of our discussion
today. It's from Earth Science dated August 22.
Many of you will probably get this. On the third
page it says "Although there are several hundred
documented cases of pollution caused by leachates
from solid waste disposal sites, few contain data on
the magnitude of the pollution and its effect on
the hydrologic cycle." We have several hundred
solid waste disposal sites here in Colorado in the
alluvial gravel of the South Platte River. We can't
say it's in the past because there is a new one
starting in Adams County right now. It's the same
thing, a water-filled gravel pit that's going to be
used as a sanitary landfill. How much damage has
this done? I don't know except that below Denver
and downstream from Denver for quite a few miles
you can't drink the ground water. Now what has
caused it? I know of two monitoring attempts on
sanitary landfills. One of them was an old landfill
and all they could tell was that the water above the
landfill was just as polluted as it was below the
landfill. So you'd have to trace it farther upstream
to find out what the first landfill really did to it.
And another one, of course, just went in and
proved what we thought; leachate was coming out
of the landfill and going into the gravel, but nobody
seemed to want to do anything about it because we
couldn't prove that it killed anybody. But nobody
really dies of drinking polluted water; they just
quit drinking it, whether it's surface water or sub-
surface water. So I don't think that it is a very good
argument that either Dr. Zanoni or you used. Water
is our lifeblood here in Colorado. And we look very
longingly at the East where you get dilution. There
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isn't anything we do with our water here that
doesn't hurt it. We just can't do anything with wa-
ter but what the water is worse when we get
through with it than it is when we start. Water from
the South Platte doesn't start to clean up again
until it gets to Grand Island, Nebraska, and that's
too far to bring it back up to Colorado to use it.
So we have no dilution factor at all. Going out the
west slope to California is even worse. They are
beginning to complain even more than Nebraskans
about the type of water we're giving them.
Don Langmuir:
Leland, can you give me some details on the
techniques that were used in sampling for the trace
metals in your study? We've had some difficulty,
and we're trying to learn techniques ourselves at
Penn State on trace metal sampling and analysis,
and I'd be curious if you could elaborate on how
you did this.
Leland Mink, University of Idaho, Moscow:
We ran into some problems in sampling, espe-
cially the mine waters. The natural waters within
the environment didn't pose too much of a prob-
lem. As one probably noticed, I didn't mention
anything about acidification of the sample upon
collection. We collected in a polyethylene bottle
and analyzed for a few parameters in the field and
then transported them to a lab. Within the labora-
tory we just allowed the sample to settle, took the
supernatant from the top and analyzed on the AA.
The problems we ran into on acidification were
numerous. First off, we experimented on acidifica-
tion and found that even though the acidification
will minimize the absorption on the container
walls, we also were stripping ions off of the sus-
pended solids contained in the sample. And upon
filtration we removed a lot of the material within
this. Also we found acidification of some of the
mine waters caused a precipitate to form which
completely eliminated some of the parameters we
were looking for. So we found that acidification
posed more problems than nonacidification;and by
allowing it to settle, we assumed that we were
approximating conditions we would find in a
natural environment. When these sediments would
settle out they would not be available to the
aquatic life.
Don Langmuir:
The settling was before acidification?
Leland Mink:
Right—the acidification was experimental. We
never did acidify the sample.
Don Langmuir:
You have another problem of absorption with
pH changes in plastic bottles because of gas transfer
through the bottle walls. A pH change will affect
the absorption and can change the trace metal con-
tent in the supernatant before you even acidify it.
This is a thorny business. People have argued against
using plastic bottles because they are so much
worse than glass bottles in this regard. #
Paul Plummer:
I have a question on standards. We've talked
a lot about sampling and various levels which have
been set by the U. S. Public Health Service, Drink-
ing Water Standards and others. Are these standards
based on total water, or are they all on filtered
water? This is a problem we ran into. We are
sampling from wells. Do we sample it the way it
comes out of the well, or do we filter it through an
0.45 micron filter which, again, is very arbitrary.
And how then, if it is filtered, does this relate to
what the standards may be? Does anyone have any
comments on this?
Don Langmuir:
I think the U.S.G.S. normally refers to the
0.45 micron filter when filtration is considered, and
it is normally on a whole sample at that point. You
take it through that filter, then you are considering
what is in the sample. But that's an awfully im-
portant point to think about too. For example, are
you concerned about what is transported in sus-
pended sediment in stream load? Because it is a
genuine pollutant if it is toxic and on the sediment.
It should be considered. Although it may come out
of the water supply where you have coagulation
and filtration before it goes into the water distribu-
tion system, it still is transported and it still is
worth considering. What you really have to do is
say that the trace metal or toxic material is smaller
than 0.45 micron or bigger than 0.45 micron. If
you don't do this you're in trouble.
Bob Kaufman:
I'd like to know how many people are drink-
ing 0.45 micron filtered water out of their wells?
Roy Williams:
I'd like to comment on that problem. The
EPA currently is suggesting that Idaho, for instance,
write standards in terms of what they call total
metals which means acidifying thf sample, which
strips things off and busts up sulfides and gives
phenomenal concentrations of zinc, let's say, in
water. Very few mines can operate with standards
that are being proposed when analyses are done in
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this fashion. The problem of transporting is not so
cut and dried. The ions that are attached to the
sediments are undoubtedly transported, but we've
got analyses of both the sediments and the water,
and there is very little relationship. For instance,
lead which is high in the sediments, is zilch in the
water. So when you're setting water quality
standards it makes very little sense to say let's take
the total. Let's go pick up a sample during flood
stage when things are murky. You will get a wild
reading which is not indicative of what is really in
the water.
The other thing that bothers me a little bit is
that the procedures being used now are quite
variable throughout the country. They need to be
standardized in terms of monitoring procedures.
We need some nationwide conferences among the
monitoring agencies because you get things you
can't compare from one part of the country to
another as a result of the different procedures that
are being used.
Jack W. Keeley:
I think Bob Kaufman made a very profound
introduction and I'm surprised that someone didn't
follow it up. Are we not really talking about what
use is to be made of this water? We take it as we get
it. If we're talking about a streamflow that is
variable in terms of its silt load which in turn gives
variance to the amount of material that is sorbed,
and this is what we're drinking, aren't we really
getting back to perhaps a statistical base of setting
quality standards?
Roy Williams:
Well, most people are no longer (in the North-
west anyway) talking about drinking water stand-
ards. Those are way too high for aquatic life,
particularly the kind of aquatic life that the pres-
sure groups in the Northwest are interested in
preserving. And even if you do consider a statistical
base you're still stuck with some technique that
gave you a number with which you have to live.
I might make one more comment on this
problem. Personally, I feel that the way to go is to
let the solids settle out. One thing we didn't do,
which we should have done, was let them settle out
for a definite, constant period of time and then
analyze the supernatant. You've got the contact
between the solid and the water to give you a
constant equilibrium which you don't have any
other way.
Don Langmuir:
Can I comment on the chemistry of that? If
you have a plastic bottle with a sample in it and
you let it sit on the shelf for a week, it will breathe.
134
Most ground waters are higher in carbon dioxide
than surface waters by a factor of 10:100 or more.
It is going to go out through the bottle walls, and
the pH change can commonly be half a unit or
more. If you're talking about absorption on the
sediment at the bottom of the bottle equilibrating
with the liquid above it, it's going to be messed up
by this pH change because the hydrogen ion is
competing with the metals. So this is kind of a
risky way to go. If you can get it to settle in a day
and refrigerate it while it is settling, that may work.
Or if you use glass bottles and fill them to the top
that will work.
Paul Plummer:
The criteria which I used was if this is the way
the people drink it, this is the way we will analyze
it. In other words, if the people are drinking water
from the well and this has not been filtered through
an 0.45 micron filter, this is the way I want to ana-
lyze. Now the problem I have run into is, does the
data that I am getting correspond with the limits
which have been set? I feel they probably don't. I
suspect that many of these standards were set at
some detectable limit, whatever year they were
established. We could detect cadmium to 0.01 mg/1
so that's the standard. Since that time we have
added a zero to the thing and now we can detect
cadmium to 10 mcg/1 but I don't think this is
necessarily the case in a lot of analysis. Still, it is
the total consumption of say lead or zinc that is
important. If the material leaves the sediment, it
becomes available to the biota and their processes.
It is well documented that fish and other organisms
concentrate metals; then maybe we really want to
know what the total is, including the sediments as
well as the filtered water.
Roy Williams:
I think the significance of the precipitation
business that Leland mentioned can't be over-
looked. Not many people have messed around with
mining wastes, and I can take you to an effluent
which, if acidified, you could watch the solids
precipitate out of solution into the bottom of the
bottle. I can only take you to one place where you
can watch it. I can take you to other places where
you will see changes take place. Somebody needs to
look into this in terms of a research project.
Jack W. Keeley:
We seem to be burning out after two hours.
Are there any questions?
Joe Miller:
To get back to our so-called sanitary landfills,
I haven't heard any mention at all of what these
operators bring into the landfills between midnight
-------
and reveille in 5,000 gallon tank trucks. This is
rather a common practice. Any comments?
Michael Apgar:
I wouldn't say that most municipal landfills
are guilty of having exotic industrial wastes dumped
into them while nobody is watching. It depends
upon what type of industries you have in the area.
Who knows what they're doing with their wastes?
This can be a problem because some of the wastes
that come out of industrial sites are extremely
toxic and tricky to handle.
Joe Miller:
It's not only the industrial, Mike. I'm thinking
of a pharmaceutical waste which I know was put
into the outcrop of a formation, as I said, during
the designated hours between midnight and reveille.
There are no monitoring wells.
Dick Rhindress:
I think I can comment at least on a partial
solution to this. We have recently surveyed by mail,
and we're following up with on-site inspections by
our industrial waste people, finding out what prod-
ucts are made, what by-products are likely, and
what the wastes are going to be. And we're asking
what they are doing with this specific waste. If we
know it is the kind of plant that always generates
phenol, for example, we go in and ask specifically
what they are doing with the phenol. Half the time
they tell us they're taking it to New Jersey or
something like this. At least this is a partial solu-
tion. I realize we're not going to get the gospel
truth out of all these companies, but it is a start
at preventing the midnight to dawn dumper. They
still exist though, I realize.
Bob Kaufman:
Jack has asked me to take over for a few
minutes. Any more questions on the landfills? I
have a comment for John Rold. How many publi-
cations has the U.S.G.S. had on sanitary landfills?
I know of one. You made the comment that the U.
S.G.S. had documented 700 cases of pollution
from sanitary landfills.
John Rold:
They said they were documented. They didn't
say they had done it.
Bill Seevers, Geraghty and Miller Inc., Port Wash-
ington, New York:
The only point I raise is the fact that sanitary
landfills are associated with our populated areas.
This is where we live. Mining problems are in the
relatively unpopulated parts of the country. There
are regions in the Northeast where we are simply
running out of space; and in a sense, this is part
of the problem with sanitary landfills. We've got
the physical problem of the landfill, but we also
have the space problem. So this is why 1 view it as
a rather serious situation.
Dick Rhindress:
Aren't we really saying that we've got to
dedicate some land to landfilling, and are we saying
let's choose the best techniques we have and use
them in landfill design. Or, are we saying that we
have a fairly good handle on how to clean up the
leachate from landfills by collection and treatment
systems or natural renovation at very good sites.
We do have a pretty good handle on it, and it is
something we can control. In the case of mining,
we still don't really have our technologies down
anywhere near where we do on landfills.
JackW. Keeley:
Are there any pertinent questions? The hour
is getting late. I'd like to make an attempt at
summarizing very briefly. First of all, with respect
to landfills, it appears that we do have sufficient
technology available to install sanitary landfills. We
should use this technology as best we can because
the garbage truck is coming. We can make an anal-
ogy here to all types of engineering designs where
we enter into them knowing that there is a possi-
bility of failure. We can, with the knowledge availa-
ble, reduce this probability. Further, we realize that
there are things yet unknown, and we will con-
tinue to improve both our techniques to measure
and our abilities to control. We have pointed out
that there are several techniques available to handle
leachates from landfills. One may or may not be
appropriate at any one location and we are mindful
of this. We are also mindful that in dealing with a
ground-water resource we must be a little more
careful because a ground-water resource once pol-
luted remains polluted for a protracted period of
time in comparison to a surface-water resource.
With respect to mine pollution, it seems that
we dealt mostly with our ability and inability to
sample, measure the contents of that sample, and
understand what that measurement describes.
Now then, are there any additions, omissions,
or corrections? Then let's adjourn.
135
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Methods of Geologic Evaluation of
Pollution Potential at Mountain Homesites
by James P. Waltzc
ABSTRACT
Development of mountain homesites is accelerating
in the Rocky Mountains of central Colorado. These home-
sites often require individual water wells and sewage dis-
posal systems. Unfortunately, the widely used septic tank-
leach field system generally is not suited for use in the
mountainous terrain where soils are thin or missing.
Although current federal regulations call for six feet or
more of soil at the leach field site, many of the individual
sewage disposal systems now in operation in the Rocky
Mountain Region of Colorado fail to meet this requirement.
Sewage effluent at these sites may directly enter bedrock
fractures and travel large distances without being purified.
As a consequence, contamination of streams, lakes, and
ground water from these malfunctioning leach fields has
become a problem of increasing magnitude.
Investigations of geologic, topographic, and hydro-
logic conditions at over 100 homesites in the Rocky Moun-
tains of north-centra! Colorado have resulted in the develop-
ment of objective criteria for evaluating pollution potential
at mountain homesites. In addition, the results of these
investigations indicate that contamination of water wells
may be decreased significantly where geologic conditions
are considered in the selection of sites for leach fields and
wells. Although the results of these studies should be
considered preliminary, they do tend to confirm that the
orientation of jointing surfaces in the bedrock significantly
affects the travel path of contaminants.
The press of our growing population and the
increasing affluence of our society have resulted in
more and more people buying homesites in the
scenic and relatively isolated mountainous area of
central Colorado. These mountain homesites often
require individual wells and sewage disposal sys-
tems. Because many of the privately owned sewage
disposal systems are poorly situated or improperly
designed, wells and streams in the mountains are
susceptible to contamination. Current federal regu-
lations provide the principal constraints on design
and construction of septic tank-leach field systems.
These regulations are intended for use in regions
where soil is six feet or more in thickness beneath
the leach field area. Many of the individual sewage
Presented at the National Ground Water Quality
Symposium, Denver, Colorado, August 25-27, 1971.
^Assistant Professor, Department of Geology, Colo-
rado State University, Fort Collins, Colorado 80521.
disposal systems now in operation in the Rocky
Mountain region of Colorado are in technical
violation of these federal regulations because of
unsuitable soil conditions.
The mountain homesites are usually character-
ized by exposures of bare rock and areas of thin or
discontinuous soil. This condition permits water
and any contaminants which are present to directly
enter fractures in the rocks. The filtering and puri-
fication of leach field waters can occur where soil
or similar material receives the effluent, but the
fractured crystalline rocks which underlie many
mountainous areas do not effectively filter the
percolating effluent. In addition, the rate and
direction of contaminant movement through frac-
tured rock may be difficult to identify. Therefore,
the location of a leach field on a tract of land may
be critical if contamination of well water is to be
avoided. Current procedures, however, base selec-
tion of a leach field site largely on topographic and
convenience factors. Where the subsurface consists
of fractured crystalline rock, this is not a satis-
factory practice. It should be clearly understood
that the rule of thumb which calls for placement of
a leach field downslope from a water well does not
provide much insurance against contamination of
the well water in mountainous terrain.
Investigations of over 100 homesites in the
Rocky Mountains of north-central Colorado indi-
cate that contamination of water wells may be
decreased significantly where geologic conditions
are considered in the selection of sites for leach
fields and wells. Two separate but related field
studies in Precambrian igneous and metamorphic
terrain, supported by the Office of Water Resources
Research, have provided data which illuminate the
role of geologic conditions in the travel of ground
water and contaminants in fractured media.
DISCRIMINANT FUNCTION ANALYSIS
In the first study (Freethey, 1969), 28 moun-
tain homesites in north-central Colorado were
selected for detailed analysis of variables thought
to be related to pollution potential. See Figure 1
for general locations of study sites. The homesites
136
-------
were separated into two groups: the contaminated
sites (Group I) consist of homesites where con-
tamination of the well water can be documented
and a pollution source can be identified; the un-
contammated sites (Group II) consist of homesites
where no contamination can be detected but where
a pollution source is present. Placement of a
particular horncsite into either Group 1 or Group II
was done on the basis of a water quality test for
Escbericbia coii bacteria. Seven of the twenty eight
sites studied had wells which were contaminated
with E. coli bacteria.
LARIMER
i CO.
WYOMING _
"COLORADO
RED FEATHER
LAKES AREA
BASE LINE 40*N
BOULDER
Fig. 1 Location map of areas studied. Areas are cross-
hatched.
Selection of Variables
Quantitative measures of geologic, topograph-
ic, and hydrologic variables were collected at each
homesite.
Geologic variables were devised to show the
probable direction of effluent movement in relation
to the position of the leach field and the well.
Field data included measurements of the strike and
dip of all major joint sets, foliation directions, and
other fractures. These data were combined to
obtain a "resultant" strike and dip which could be
used as an approximation of the direction in which
fluids would move through the unsaturated frac-
tured media. To take into account the effects of
spacing and width of fractures on permcabilitv, a
weighting procedure was devised by which fracture
sets which appeared to be relatively impermeable
would be assigned a ranking ol one and fracture-
sets which appeared to have high permeability
would be assigned a ranking of five. Fractures
o C"
which appeared to have a moderate permeability
were assigned rankings of two, three or four de-
pending on their apparent permeability. The "re-
sultant" dip direction is obtained graphically using
the rankings given to each measurement. Figure 2
shows an example of this procedure. The vector
which represents the first measurement with a
ranking of one is drawn only halt as long as the
vector for the second measurement, which has a
ranking of two. After the resultant of one and two
is obtained, vector number three is drawn, which
because of its ranking of three, is three times as
long as number one. The final resultant dip direc-
tion is obtained by drawing another parallelogram,
the sides being measurement three and the resultant
of measurements one and two. The dip angles of
each of the original surfaces are then projected
onto the vertical plane of the hypothetical resultant
dip direction. These apparent dips can be quickly
determined with the use of a special protractor
(Lahee, 1952). The apparent dips are then averaged
according to their rankings, and a hypothetical
resultant dip angle is obtained. This procedure is
shown in part B of Figure 2.
Measurement Dip direction Dip Ranking
Fig. 2. Example for calculation of the "resultant" strike and
dip of fractures in rocks (after Freethey, 1969).
Geologic Variables
Three geologic variables used ;i this study
involve angular relationships between the "result-
ant" strike and dip of fractures at each site and the
orientation of a reference plane. The reference
plane at each homesite is the vertical plane which
137
-------
passes through the leach field and the well. Figure
3 illustrates the geologic variables. A description ot
the variables follows:
Variable * 1. Angle between the azimuths of the
"resultant" dip and the leach field-well plane.
Variable *2. Acute angle between the azimuths of
the "resultant" strike and the leach field-well
plane.
Variable * 3. Vertical angle between the line con-
necting the leach field with the water level in the
well and the projection of the "resultant" dip
onto the leach field-well plane.
Variable *4. Degree of rock weathering. (.Because
weathered rocks may be effective in filtering and
cleansing leach field effluent, some assessment of
this variable was considered essential in evalua-
tion of pollution potential at mountain home-
sites. A ranking procedure was devised. A rank of
one represents relatively unweathered rocks, a
rank of five represents a highly weathered rock
mass.)
projected "Resjltant"
water table gradient and the leach field-well
plane. (In several cases the azimuth of the water
table gradient was estimated from land surface
topography.)
Variable *6. Depth to static water level in the
well.
Variable #7. Vertical angle between the well head
and the leach field.
Variable *8. Angle between the azimuths of the
topographic gradient in the immediate vicinity
of the leach field and the leach field-well plane.
Variable #9. Magnitude of the topographic gradi-
ent at the leach field as projected onto the
leach field-well plane.
Variable * 10. Horizontal distance between the
well and the center of the leach field.
Fig. 3. A. Diagram illustrating variables *1 and *2;
B. Diagram illustrating variable *3.
Fig. 4. A. Diagram illustrating variables *6, #7, #9, and
#10; B. Diagram illustrating variables #5 and #8.
Hydrologic and Topographic Variables
"Ihe remaining variables used in this study
were devised to represent those hydrologic and
topographic conditions at the various homesites
which are considered to be related to pollution
potential. Figure 4 illustrates these variables. A
description of the variables follows:
Variable »5. Angle between the azimuths of the
Statistical Analysis
A discriminant function analysis was done to
determine if any of the ten variables used were re-
lated to or sensitive to the incidence of pollution.
Briefly, the discriminant function analysis is a
standard statistical technique which computes a
linear function of n variables measured on each
individual of two groups. This linear function
138
-------
provides a criterion for discrimination between the
groups. The function is computed so that the dif-
ference between the mean indices for the two
groups divided by their pooled standard deviation
should be as large as possible. Fisher (1946) dis-
cusses the computational steps and data require-
ments for the discriminant function analysis.
Results of Discriminant Function Analysis
The two most significant variables were varia-
ble # 1 (angle between the azimuths of the "re-
sultant" dip and' the- leach field-well plane) and
variable #8 (angle between the azimuths of the
topographic gradient at the leach field and the
leach field-well plane). The significance of variable
# 1 apparently stems from the tendency of leach
field effluent to follow the dip of fractures in the
zone of aeration. The significance of variable #8 is
possibly due to the tendency for near surface
fluids to percolate laterally down slope in response
to gravity and zonation of weathering. If lateral
movement of effluent from the leach field has a
component toward the well, pollution potential is
increased.
Using only variables # 1 and * 8, a discriminant
function significant at the 0.1% level was obtained.
The values of the discriminant function for all 28
sites are given in Table 1. Values of the discriminant
function are computed using the following formula:
D(f) = -.00196(V,)- .0015(V8)
where D(f) is the discriminant function, V\ is the
value for variable one, and V8 is the value for vari-
able eight. The discriminant function D(f) can be
calculated for a site if estimates can be obtained
for variables # 1 and # 8.
FLOW FIELD DIAGRAM METHOD
The second study (Millon, 1970) included 85
mountain homesites in the Red Feather Lakes
Area, Larimer County, Colorado (see Figure 1).
Sixty two percent of the wells tested at these
homesites were found to be contaminated with
E. coli bacteria. Data collected for 65 well sites
established the position of each well relative to the
nearest leach field. Data were also collected on the
orientation of bedrock jointing surfaces and on
water levels in wells so that ground-water flow
directions could be evaluated. Figure 5 shows
contours drawn on water level elevations in wells.
The study area was divided into 9 subareas in order
to obtain a single generalized direction for the
hydraulic gradient in each of the subareas. The
generalized directions of the hydraulic gradient are
indicated by the wide arrows in Figure 5. Orienta-
tions of major high angle joints in the Red Feather
Table 1. Discriminant Function Values
(after Freethey, 1969)
Rank
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
Values for
polluted
group
-.09678
-.12491
-.14253
-.18165
-.24230
-.29549
-.35614
Values for
unpolluted
group
-.22372
-.24201
-.28114
-.28536
-.30788
-.32189
-.36201
-.37507
-.37766
-.38321
-.39665
-.40115
-.40573
-.41615
-.41615
-.41714
-.42856
-.44093
-.46410
-.48433
-.51041
Polluted
site no.
5
2
3
1
4
6
7
Unpolluted
site no.
20
18
19
21
12
13
17
10
6
3
14
15
11
8
9
2
16
7
1
4
5
Lakes Area are summarized in Figure 6. The
ground-water flow pattern at any point in the area
was assumed to be determined by the combined
effects of the hydraulic gradient and the orienta-
tions of both major and minor jointing surfaces in
the rock.
The data on well and leach field locations,
joint orientations, and ground-water flow potential
were all combined by means of a specialized "flow
field" diagram (see Figure 7). This diagram is in-
tended to graphically illustrate how bedrock frac-
ture orientations may affect transport of leach field
effluent by ground water. A region of high pollu-
tion potential can be identified on the flow field
diagram.
Results
The study showed that wel's in the Red
Feather Lakes Area which, because of their posi-
tion relative to nearby leach fields, plot on the flow-
field diagram within the region of high pollution
potential have about four times the incidence of
pollution as do wells which plot outside the region.
139
-------
Red Feather
Lakes
Colorado
Fig, 5. Map showing subareas and hydraulic gradients for the Red Feather Lakes Area (after
Millon, 1970).
joint orienta-
tions
sf»ear zones
L.Nafcwnis
1500 3000
tcaie (ft.)
i. Hiawatha
^ I
.Ranncna
Red Feather L.
/
o
Shajwa L.
s
Fig. 6. Map of Red Feather Lakes Area showing generalized orientations for major joints and shear zones
(after Millon, 1970).
140
-------
location of non-
polluted well
location of
polluted veil
strikes
prominent
joi
in sub area
nt systems
Ground water flow direction imposed by the
hydraulic gradient in the water producing
zone of the sub area (marked with 10° range
in each direction).
Zone of ground water flow direction imposed
by the confinement of direction within high
angle joints of the sub area.
Fig. 7. Hypothetical flow field diagram showing locations
of wells in relation to neighboring leach fields (after
Millon, 1970).
A normalized significance test employing
Bernoulli data (i.e., the percentage of polluted
wells in the flow field and the percentage of non-
poiluted wells in the flow field) was of the follow-
ing form:
t =
7Tp - 7Tl
= 2.31
JTT
1
rr
A i
where
number of
polluted wells in flow field
25
•= — = .555
?TT =
total number of polluted wells 45
total number of wells in flow field 30
— = — = .462
total number of nonpolluted wells in flow field
total number of nonpolluted wells
= .25
total number of wells
65
20
N, = number of nonpolluted wells = 20
N2 = number of polluted wells = 45.
The "t" value obtained by the above formula
showed statistical significance at the one percent
level.
CONCLUSIONS
The analyses which have been described can
be reliable only if geologic conditions are adequate-
ly represented. A hidden fault or igneous dike can
invalidate a site evaluation based on the discrimi-
nant function or flow field criteria. Hence, these
methods for evaluating pollution potential at
mountain homesites* should be considered reliable
only in the statistical sense. Much additional data
must be acquired before an acceptable criterion for
evaluation of pollution potential can be developed.
Although results of these two studies should
be considered preliminary, they do tend to confirm
that the orientation of jointing surfaces in the
bedrock does affect the travel path of contami-
nants. Thus, evaluation of pollution potential at
mountain homesites similar to those investigated in
these studies must include detailed geologic analy-
sis of bedrock underlying the thin soils.
REFERENCES
Fisher, R. A. 1946. Statistical methods for research workers.
Oliver and Boyd, London, 10th ed., 356 pp.
Freethey, G. \V. 1969. Hydrogeologic evaluation of pollu-
tion potential in mountain dwelling sites. M. S. thesis,
Colorado State University, 90 pp.
Lahee, F. H. 1952. Field geology. McGraw-Hill Book Co.,
New York, Appendix 14, 583 pp.
Millon, E. R. 1970. Water pollution, Red Feather Lakes
Area, Colorado. M. S. thesis, Colorado State Uni-
versity, 68 pp.
DISCUSSION
The following questions were answered by James
P. Waltz after delivering his talk entitled "Methods
of Geologic Evaluation of Pollution Potential at
Mountain Homesites."
Q. \Ybat is the range of values of the diversion
radius of the well compared to the distance be-
tween well and waste disposal sites?
A. The problem of proper spacing between leach
fields and wells is a very real one. I showed a
diagram which illustrated that fluid can travel from
the leach field toward the well along fractures in
the zone of aeration. I showed another portion of
the diagram which demonstrated that local topo-
graphic reverses might cause percolating fluids to
enter the ground water upstream of the well be-
cause the regional ground-water gradient is different
from the local topographic slope. There is also the
very common problem, which the questioner has
raised, where the leach field is at the ground
surface and is recharging the ground water while
the well is perhaps 200 feet away pumping water
141
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and creating a large cone of depression in the
ground water around the well. This condition re-
verses the ground-water gradient so that even if the
well was originally upslope both topographically
and with respect to the ground-water gradient the
flow direction can change very quickly.
I don't have any figures for the shape and size
of the drawdown cone. It will probably be a while
before we know very much about that. The prob-
lem can be approached on a theoretical basis,
assuming fractures are like parallel plates. We've
done some experimenting with this type of model
to determine the interaction between a series of
wells and a series of leach fields as, for example,
would occur in a subdivision. The results from this
type of analysis are useful but fairly generalized.
The fact of large diversion radii of mountain wells
certainly contributes to the pollution potential
because the storage capability of fractured crystal-
line rocks is minuscule compared to most aquifers.
We're talking about less than 1% porosity, even in
fairly fractured rock. Tremendous drawdowns are
associated with the withdrawal of water and this
certainly is going to affect the direction of ground-
water flow in the vicinity of the well.
Q. Arc there E. coli in the lakes and streams of
the Red Feather Lakes Area?
A. Yes.
Q. What u-ere their percolation rates?
A. The percolation rates vary tremendously. Even
within an individual half acre or acre lot it is
possible to get a wide range of percolation rates.
Q. Were the contaminated wells evaluated for
sanitary construction?
A. No, the homesites that we checked were home-
sites which had been in operation for quite some
time, and we assumed that the wells were in a state
of equilibrium with their environment, including
the nearby leach field. I think that in some cases
there might have been poor construction practices
associated with the contamination.
Q. Was any attempt made to clean up the contami-
nated wells with Marine?
A. Certainly. Many of the people in these areas
that we studied have gone to chlorination systems.
This is one certain way they can fight the problem.
We had to make special arrangements to obtain
our samples from their nonchlorinated supply. We
sometimes tapped into their water system upstream
from the chlorination.
Q. Were tests run for other enteric bacteria?
A. There was a facet of our study done by our
microbiologist which included additional testing
but no extensive program of testing has been done
other than on the E. coli.
Q. Do you believe values of variables V-l and V-8
can be reliably obtained in the vicinity of most new
homesites?
A. Data for these variables must be collected by a
geologist. The data collection presents an interest-
ing problem because many of the homesites are
built on somewhat flat ground where thin soils
commonly obscure the bedrock. It is necessary to
go to the periphery of the homesite to find the
rocks that are in place where orientations of frac-
ture systems can be recorded. We usually would
measure at least several dozen fracture orientations
to establish the uniformity of these fractures
throughout the homesite area. Where we could do
this, I feel the measures are reliable, but in some
cases we had exposures on maybe only 2 or 3 sides
of the property. In these cases there is room for all
sorts of geologic features which can invalidate the
criterion. As I have said, we're hoping here only for
the statistical validity. There is no absolute security
in the discriminant function criterion because there
are often going to be complicating geologic factors.
Q. How do you evaluate the reliability of j rela-
tively variable discriminant function?
A. We hope to evaluate this discriminant function
after we have extended the data base to include a
large number of sites. Then we wish to apply it to
a number of unknown sites and test the success of
our classification. I think this can be done. Relia-
bility can be tested in a statistical sense. The
discriminant function is variable because of the
nature of the function. If it were not highly variable
then its value as a classification criterion would
be less.
Q. Why not simply require a chemical home treat-
ment system where there is less than 6 feet of soil?
A. Economics appears to be the main reason. How-
ever, there must be alternatives to the septic tank
leach field system in these areas where there is an
inadequate soil. Here in Colorado, the Water Pollu-
tion Control Commission has issued new rules on
septic tank practices which include the "designa-
tion" of pollution prone areas in the State. For
these "designated" areas, special engineering and
geologic studies will be required before approvals
for private sewage disposal systems can be ob-
tained. It looks to me like this is a great step
forward. What it will likely mean is that a detailed
investigation will show that a septic tank system
cannot be installed in most areas and alternative
systems will have to be considered. I'm not a
sanitary engineer and I don't know about the
142
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success of many of these chemical systems. I have
heard that many of the present alternatives to
septic tank systems are not entirely reliable because
they require a degree of maintenance which is
often lacking. The leach field system has worked
beautifully where conditions are appropriate be-
cause it doesn't really need much maintenance.
Q. Do you have any minimal lot size regulation for
lots hi Precambrian crystalline rocks where both
wells and septic tanks are used?
A. In order to assess the minimum size of lots
from mountain homesites we need to know a little
more about what happens to the bacteria that
enter the fracture bedrock. We know that they
can easily travel hundreds ot feet, and we may
even be talking about travel of U of a mile or more
without being appreciably filtered out or absorbed.
We are presently involved in studies where we've
taken different rock types, crushed them, sized
them, and added water containing known quanti-
ties of E. coli. The fluids were periodically tested
for two weeks to determine a die-off curve for E.
coli. We found remarkable variations in the chemi-
cal effect of the rocks on the viability of the
organisms. I think this sort of data will ultimately
be useable in determining minimum lot sizes for
various types of geological terrain. We have also
attempted to learn a little more about the rate of
travel of fluids through crystalline rocks, because in
addition to the time that is required to kill off
these organisms in the rock you must be concerned
about how fast the fluid is going to move in that
period of time. These data are necessary- to deter-
mine what the safe radius from a leach field is
going to be. So we have taken areas such as the
road cut shown in this picture, where well defined
joint sets can be seen, and injected fluids into the
rock fractures. We put 55 gallon drums filled with
bacteria-inoculated water at the top of the cliff and
siphoned the fluid into PVC pipe that had been
cemented into the rock. In this case the bacteria-
laden water surfaced down here at approximately
15 to 20 feet away from the injection point. I
just wanted to show that we get effluent coming
out of this rock, this highly fractured rock con-
centrated at this location. We were able to collect
the fluid and sample the bacteria. We found that
essentially nothing was filtered out. The same con-
centrations were at the bottom as at the top. Little
seeps occurred at 3 or 4 other places, but this was
the only place where any real flow occurred and
the rate was quite high. We had a garden hose, and
as fast as it would siphon, the fluid would go into
the rock.
Q. Who is working on development of a better
septic tank system?
A. 1 have nothing more to say about alternatives. I
know there are lots of people who recognize that
the septic tank needs to be improved or replaced
for installations in mountainous areas. 1 am confi-
dent that there are better solutions presently avail-
able and that they will be used only if the pressure
is put on people to not use septic tank-leach field
systems any more where terrain is not suitable. We
just have to cut them off.
Q. Here's a question about your testing methods
for E. coli. Do you mean coli form by standard
method? What technique did you use for E. coli
analysis? Did you rim any tests for f-cai c.n'nform
since these are a better indicator of domestic
sewage contamination?
A. I wish I had the microbiologist associated with
this project here to answer that question. We, for
the studies I've recorded here, did test only for the
E. coli. We considered a site to be contaminated if
large numbers of E. coli were present in the water
samples taken. We did find variations in the content
of E. coli in the samples we obtained. We took
several samples at each site and replicate determina-
tions were made. We went back on different days,
different weeks, and in some cases as many as a
dozen or more samples were repeated so that we
were relatively sure of the status of contamination.
And, in some cases, definitely contaminated wells
would be retested and turn out to be okay. We
tried to tie this in with precipitation patterns and a
number of other things. There are obviously a
number of factors which influence the changes
with time in the concentration of E. coli in ground
water.
143
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Nitrate in Ground Water of the Fresno-Clovis
a
Metropolitan Area, California
by Kenneth D. Schmidt
Member N\VWA
ABSTRACT
N.itu'.il concentrations of nitrate are quite low in
most ground waters in the eastern part of the San Joaquin
Valley. High nitrate contents are related to sewage effluent
percolatu n ponds, septic rsnk disposal systems, industrial
waste-waters, .mil agricultural fertilizers. Hydrologie factors
are closely related to the occurrence of nitrate. Transmissi-
bilitv of the aquifer, hardpan development in the soil, canal
recharge, and cobble zones in the subsurface are the primary
factors of importance. Nitrate is stratified in the aquifer
beneath unsewered metropolitan areas and highest contents
occur in the upper 50 or 60 feet. Water quality hydmgraphs
were used to show long- and short-term trends in nitrate.
Chloride and nitrate hydrographs, triiinear diagrams, the
distribution of other constituents, and hydrologic data were
used to efiVcnvch delineate sources of nitrate in areas
where numerous potential sources were present. Conclu-
sions fr 'tn •_'!''>und-\\.ner c!a;,j .igic' -.veil with previous
studies tn other areas beneath unsewered tracts and near
sewage treatment plants in which attention was focused
pnrnanfv on the soil or the unsaiurated /one.
INTRODUCTION
Fresno County was formed in 1856 out of the
Mariposa territory and currently produces the
greatest amount of agricultural wealth of any coun-
ty in the nation. The Fresno Irrigation District
(.Figure 1) supplies surface water to much of the
agricultural area through canals from the Kings
River, which drains part of the Sierra Nevada east
of Fresno. The Fresno-Clovis Metropolitan Area
(F.CM.AJ comprises about 145 square miles be-
tween the Kings and San Joaquin Rivers in the
east-centra! portion of the San Joaquin Valley.
Rapid industrial growth has occurred in the past
decade and population of the urban area reached
310,000 in 1969.
Water lor municipal and industrial use is
pumped trom wells, whereas in the surrounding
agricultural area surface water and ground water
are used. Ground water occurs in the alluvial-fan
deposits derived from the Sierra Nevada. The
principal subsurface geologic units were divided
into consolidated and unconsolidated materials by
Presented at the National Ground Water Quality
Symposium, August 25-27, 1971.
I'HydroIogist, Harshbarger and Associates. 1525 E.
KSemdale Road. Tucson, Arizona 85719.
Si
,->
v
f
'*§->.
Fit). 1. Fresno County and related features.
Page and LeBlanc (1969). Consolidated rocks
comprise the basement complex ot pre-Tertiary age
and the marine and continental rocks of Cretaceous
and Tertiary age. The basement complex is about
3,000 feet deep beneath Fresno. Unconsolidated
deposits are the major source of ground water
pumped by wells in the Fresno area. Deposits ot
Quaternary age crop out over most ot the area and
comprise the principal aquifer. These deposits in-
clude numerous intercalated strata ot sand, gravel,
silt, sandy clay, clay, and localized cobble /ones.
Most of the ground water moves laterally in coarse-
grained beds, and the vertical movement ot \\atei is
restricted in places by thick layers of clay anil
silty clay.
The climate of the F.C.M.A. is characterized
by a long, warm, and dry summer trom May
through October, and a cool, rainy winter season
from November through April. Annual precipita-
tion at Fresno averages about eleven inches, Ihe
amount of precipitation in the foothills and moun-
tains of the Sierra Nevada directly affects the
streamflcnv, recharge to ground water, and surface
water supply. Much of the precipitation at higher
elevations falls as snow, and runott in major
streams usually reaches a peak in June or July,
following periods of high snowmelt.
144
-------
Depth of ground water averages about 70 feet
beneath the F.C.M.A., and the regional direction of
flow is southwest. A ground-water cone of de-
pression exists beneath part of the urban area due
to large pumping extractions. Sources of recharge
include seepage from streams and canals and
ground-water inflow from the east. Well depths
range from less than 100 to more than 500 feet.
Most wells were drilled by the cable-tool method
until recently, and unperforated casings were
installed with open bottoms. Recently, wells have
been drilled by the reverse-rotary method and
gravel packed. The average specific capacity is
about 1 30 gallons per minute per foot (gpm/ft) and
the average transmissibility exceeds 220,000 gallons
per day per foot (gpd/ft).
A detailed correlation of subsurface rock
types was made as part of the development of the
lithologic framework of the area. Drillers' logs were
correlated with several electric logs available. Ex-
tensive deposits ol cobbles and coarse sands occur
to depths greater than 500 feet in the northern
portion ot the I-'.C.M.A. An impermeable hardpan
ot the San Joaquin Series also occurs over much
ot the northern part ot the area. Other soils vary in
hardpan development and the Madera sand has
virtually no hardpan development. Correlations
generally suggested little continuity of clay strata,
but some cobble zones were traced tor several
miles. Clays predominate below 350 to 400 feet
depth in the southern portion of the F.C.M.A. The
depth of Quaternary alluvium ranges from 350 to
400 feet, and the underlying continental deposits
are finer grained except near the major rivers.
High nitrate in drinking water is important
because of an infant disease, mcthemoglobmemia.
Concentrations exceeding the 1962 U. S. Public
Health Service limit of 45 parts per million (ppm)
were noted in the F.C.M.A. by the California De-
partment of Water Resources (1965). The primary
sources of ground-water nitrate were identified as
sewage effluent percolation ponds at the Fresno
Sewage Treatment Plant and septic tank disposal
systems in unsewered areas. Nitrate concentrations
ranged from 0.8 to 58.5 ppm. and averaged 15.1
ppm, for the F.C.M.A. Most high nitrate contents
were from samples collected from shallow wells.
Analyses of surface waters showed low concentra-
tions of all constituents, including nitrate. Analy-
ses of wastewaters at sewage treatment plants,
wineries on independent disposal systems, and a
meat-packing plant were presented. Although high
concentrations of most constituents were apparent,
total nitrogen was generally unreported.
Behnke and Haskell (1968) studied nitrate in
ground water near the Fresno Air Terminal. They
noted the importance of septic tanks and the Clovis
Sewage Treatment Plant as nitrate sources.
Nightingale (1970) reported on the salinity and
nitrate trends for ground water of the urban area
and the surrounding agricultural lands. Although
urban zone well water nitrate was almost twice
that ot the agricultural zone for the period 1950-
56, for the period 1962-67 the two zones had an
almost equivalent nitrate content. The mean nitrate
content of the agricultural zone well water in-
creased by 300 percent from year lot 1950-56 to
year lot 1962-67, but no reason for this increase
was given.
Despite these studies and others, many ques-
tions have remained unanswered with regard to
c
ground-water nitrate in the F.C.M.A. Questions as
to source, effect of lithology and well construction
on nitrate, and relation to the hvdrologic svstcm
C? -
often have arisen. It is my intent to establish a firm
hydrologic framework for the present study. A
model can be built upon this framework to describe
the sources and distribution of nitrate in ground
water of the F.C.M.A.
Five sites were selected for detailed analysis
(Figure 2). The Figarden-Bullard Area was selected
because of the prevalence of one nitrate source,
namely septic tank effluent. A second site selected
was the vicinity of the Fresno Sewage Treatment
Plant, which comprises the majority of sewage
treatment on a volume basis in the F.C.M.A.
Sewage effluent disposed ot by percolation ponds
is the primary nitrate source to ground water in
this area. The Tarpey Village and Mavfair-Fresno
Air Terminal Areas are both unsewered and have
R. 19 E.
: SEWAGE TREATMENT
Fig. 2. Study areas in the Fresno-Clovis Metropolitan Area.
145
-------
some of the highest nitrate contents reported in the
F.C.M.A. Sources other than septic tanks are
present, including sewage effluent percolation
ponds, winery wastewater disposal ponds, and
agricultural fertilizers. The fifth study site com-
prised the Downtown Fresno area, which is sewered
and has no obvious nitrate source. Although high
nitrate contents have been monitored by several
wells in this area, virtually no study had previously
been undertaken.
FIGARDEN-BULLARD AREA
Schroepfer and Polta (1969) reported on
nitrate in ground water of septic tank areas near
Minneapolis and related ground-water contamina-
tion to suburban growth. These authors found that
septic tank effluent had an average ammonia-
nitrogen content of 28 ppm orCTzTj^m^nitrate
equivalent. The Figarden-Bullard Area is in the
northern part of the F.C.M.A. Although the area is
unsewered, only three wells have ever had nitrate
over 25 ppm. Ground-water depth ranges from 90
to 100 feet and water levels have declined about 2
or 3 feet per year for the past decade. Lithologic
sections show an abundance of hardpan, sand, and
cobble zones in this area. Much of the hardpan is
impermeable and is in the San Joaquin sandy loam
soil type. About 80 or 90 percent of the area was
agricultural in 1950, whereas less than 20 percent
was agricultural by 1970. Population density is
lower than for most other urban parts of the
F.C.M.A.
Chemical hydrographs were prepared to illus-
trate long- and short-term trends in water quality.
The predominant historical trend in the northern
portion of the Figarden-Bullard Area was con-
stancy of nitrate. This portion has the largest
transmissibilities, the most abundant cobble zones,
and the greatest development of impermeable hard-
pan in the Figarden-Bullard Area. About one-half
of the hydrographs in the southern portion had a
constant nitrate trend, whereas the remainder had
increasing trends. The southern portion had the
earliest septic tank development and maximum
septic tank density of the area. Cobble zones are
locally absent, transmissibilities of the aquifer are
lower than in the northern portion, and the im-
permeable hardpan is locally missing.
Nitrate and chloride hydrographs (Figure 3)
were drawn for all wells where more than four
separate analyses were available. Short-term trends
indicated similar nitrate and chloride patterns for
16 out of 19 hydrographs. This similarity prevails
throughout septic tank parts of the F.C.M.A. and
is apparently due to the derivation of nitrate and
chloride from septic tank effluent and the mobility
of both ions in ground water. Three hydrographs
with opposite nitrate and chloride short-term
trends were for wells apparently affected by sewage
effluent from plants north of the Figarden-Bullard
Area.
1958 I960
1968 <970
Fig. 3. Nitrate and chloride hydrographs for a selected well.
Water samples from wells have been taken
semiannually for nitrate analysis in several Fresno
County Waterworks Districts in the Figarden-
Bullard Area. Nine wells had greater nitrate con-
tents in the summer than in the winter, and had
cased depths less than 150 feet. Higher nitrate
contents in the summer are due to downward
movement of shallow waters, which are high in
nitrate, to producing zones during heavy pumping.
Higher temperatures in the summer also favor nitri-
fication of ammonia-nitrogen retained in the soil
from septic tank effluent. Five wells had higher
nitrate contents in the winter than in the summer,
and had cased depths greater than 150 feet. This
group of wells was on canal banks or nearby. Low
nitrate contents in the summer are attributable to
canal dilution by low nitrate Kings River water, as
several major unlined canals traverse the area. Low
nitrate contents in the summer occur for wells
where the impermeable hardpan is absent through-
out the F.C.M.A.
The concept that nitrate is stratified in the
aquifer was tested in the Figarden-Bullard Area.
Only open-bottom wells were used in this analysis,
as they tend to draw water from specific portions
of the aquifer. The difference between depth to
water and cased depth is a reflection of the amount
of aquifer penetrated and is generally related to the
zone of production. Depth to water was taken from
the Fresno Irrigation District Map for December,
1970. The difference between depth to water and
cased depth is referred to herein as "aquifer pene-
tration," and values for specific wells were plotted
graphically with 1970 nitrate analyses (Figure 4).
146
-------
200
5 10 15 20 25 30 35
NITRATE IN PARTS PER MILLION
Fig, 4. Relation between aquifer penetration and 1970
nitrate for wells in Figarden-Bullard Area.
The number of wells with lo\v nitrate contents in
each major depth zone shows that there is no
continuous "nitrate cap" in the Figarden-Bullard
Area, a fact also shown by contours drawn tor
nitrate content on an areal basis. The highest
nitrate contents are in the upper 60 feet of the
aquifer, and about 5 to 7 ppm approximates the
"background" nitrate in the ground water. The
decrease in nitrate content with depth in the upper
80 feet of the aquifer averages about I ppm per 4
feet of depth. Wells with the highest nitrate con-
tents for their specific aquifer penetration were
usually within the zone of lowest transmissibility
and in the area where septic tanks had been used
for the longest time.
The low nitrate contents in the aquifer of the
Figarden-Bullard Area are attributed in large part
to hvdrogeologic factors. Extensive cobble zones
permit more dilution and dispersion of high nitrate
recharge from septic tank disposal systems. Few-
wells are extremely shallow or perforated in shal-
low intervals, and the water table is relatively deep.
The presence of an impermeable hardpan prevents
percolation of nitrogen forms in some cases, unless
it is penetrated by leach lines or seepage pits from
septic tanks. The low density of septic tanks com-
pared to other unsewered areas of the F.C.M.A. has
also minimized nitrate contents. Although the
Figarden-Bullard Area was converted from pri-
marily an agricultural area in 1950 to an urban area
at present, there is little evidence of greatly increas-
ing nitrate contents. Little downgradient movement
O t.
of nitrate from septic tank areas to sewered areas
has occurred. The Figarden-Bullard Area is perhaps
the ideal location in the F.C.M.A. for operation of
septic tank disposal systems. With proper construc-
tion of wells and septic tank disposal systems, little
problem with high nitrate contents in ground water
should occur in the future.
FRESNO SEWAGE TREATMENT PLANT
The Fresno Sewage Treatment Plant is about
3 miles southwest of downtown Fresno and has
been in operation since 1891. Plant No. 1 has
provided primary treatment since 1947 and Plant
No. 2. which was built in 1960, provides secondary
treatment. Final disposal of most of the effluent is
by percolation on 1,440 acres of ponds. About 10
to 15 percent of the effluent is used for crop
irrigation on nearby lands. Wastewater flow cur-
rently averages almost 30 million gallons per day.
The total nitrogen in domestic wastewater effluents
ranges from about 18 to 28 ppm when there is no
specific treatment for nitrogen removal. Records at
the Fresno Sewage Treatment Plant suggest that the
average total nitrogen content is about 25 to 30
t_ O
ppm, about 8 to 10 ppm of which is in the
ammonia form. Nitrate contents averaged about 6
ppm in 1969. Although industries comprise only
about 10 percent of the sewage influent to the
plant, wineries contribute significantly to waste
strengths during the period from September 1 to
December 1.
Jcnks and Adamson (1968) determined pond
percolation rates and ground-water quality at the
Fresno Sewage Treatment Plant. Fight auger holes
were drilled to reach the ground water and water
samples were collected. Five of the eight water
samples had nitrate contents less than 4 ppm,
whereas nitrate contents tor the remaining samples
were 76, 160, and 213 ppm. The holes with high
nitrate content were in a newer area where ponds
were periodically dried out in order to achieve
higher infiltration rates. These holes were apparent-
ly in an area recently dry and just flooded. High
nitrate water is common at the beginning of flood-
ing cycles (Stout, Burau, and Allardicc, 1965), and
the water is readily leached to ground water.
Ponds develop anaerobic conditions when kept full
and nitrogen is retained in the soil in the organic
and ammonia forms. Aerobic conditions develop
when ponds are periodically dried out and nitrifica-
147
-------
tion can occur. Nitrate is then leached upon the
next wetting of the ponds, and this period is fol-
lowed by low nitrate recharge water once anaerobic
conditions develop. Denitrification can also sub-
stantially reduce nitrate contents under anaerobic
conditions.
Typical percolation pond water was sampled
for a portion of 1968. Analyses for nitrate-nitrogen,
ammonia-nitrogen, and pH demonstrate the influ-
ence of winery wastewater at the Fresno Sewage
Treatment Plant. One pond had an average am-
monia-nitrogen content of about 1.2 ppm prior to
September 1, and an average of 8.5 ppm during the
winery season of September 1 to December 1. The
average ammonia-nitrogen content for another
pond was 4.1 ppm prior to September 1, and 8.5
ppm during the winery season. Nitrate-nitrogen for
the first pond during the same period increased
from an average of 0.3 to 2.1 ppm. Nitrate-
nitrogen for the second pond increased from 0.4 to
1.7 ppm for the same period. Winery wastewaters
in the F.C.M.A. have a total nitrogen content rang-
ing from 4 to 10 times that of typical domestic
sewage effluent.
Chemical hydrographs were prepared for 6
monitor wells near the Fresno Sewage Treatment
Plant. All hydrographs showed similar seasonal
fluctuations (Figure 5) for nitrate and ammonia.
Nitrate contents sharply decrease after maximum
values in September. Contents gradually -ease
to a minimum in March and gradually inci ~,e to
July. Contents sharply increase in August and
September. High nitrate contents occur in ground
water at the beginning of the winery season, when
the nitrogen contents of pond waters are very
high. However, pond waters also have the highest
biochemical oxygen demand for the entire year at
this time. These highly anaerobic wastewaters
readily utilize oxygen, and nitrification cannot
occur. Nitrogen is thus regained in the soil and not
leached to the ground water; hence ground-water
nitrate content sharply decreases. Nitrification does
not occur as rapidly during the winter and nitrate
contents gradually decrease until the spring. Nitri-
fication readily occurs with the warming tempera-
tures of the spring and summer, nitrate is readily
leached to ground water, and contents gradually
increase to the fall. Maximum nitrate contents in
the ground water each year may actually be due
to nitrogen supplied to the soil during the previous
year. Pond operation during the summer includes
more drying out cycles, as the wastewater flow is
smaller, and aerobic conditions tend to develop,
which also favor nitrification. Waste flows are the
largest in the winter and ponds are generally kept
full, allowing anaerobic conditions to develop. The
Q.
Q.
z
LU
O
o
o
WINERY
SEASON
WINERY
1 1 T 1 1 1 1 1 1 1 1 1 1 1 I I I
ASONDJFMAMJJASOND
Fig. 5. Nitrate concentrations in ground water near Fresno
Sewage Treatment Plant.
seasonal variation in nitrate (Figure 5) clearly indi-
cates the inherent limitations of comparisons made
from year to year based on only one analysis per
year.
Ammonia-nitrogen contents of ground water
show opposite trends to nitrate-nitrogen near the
Fresno Sewage Treatment Plant. The highest con-
tents occur in March and the lowest contents occur
in September. The soil retains nitrogen on ad-
sorptive and cation-exchange sites when little
nitrification occurs. Ammonia gradually tends to be
leached in small amounts as the capacity of the
soil to retain nitrogen is approached. The ammonia
contents of ground water are high when nitrate
contents are low, because little nitrate is formed
under these conditions. Much of the capacity of
the soil to retain nitrogen is unused when abundant
nitrification occurs, as much of the nitrogen is con-
verted to nitrate and leached. Little ammonia is
leached in this case, as it is either retained by the
soil or converted to nitrate.
A number of chloride and nitrate hydrographs
for wells near the Fresno Sewage Treatment Plant
exhibit opposite nitrate and chloride short-term
trends. That is, as the nitrate content increases for
a period, the chloride content simultaneously de-
creases. This trend was thus in contrast to that ob-
served in septic tank portions of the F.C.M.A.
Chlorides are an effective tracer in ground water of
the F.C.M.A., because natural concentrations are
quite low. Ground water affected by sewage efflu-
ent generally has chloride concentrations exceeding
148
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45 ppm. High chlorides in ground water near the
treatment plant suggest that little dilution of sew-
age effluent occurs, a fact also suggested by the
amount of water recharged on an annual basis. A
trilmear diagram for various ground-water samples
showed a consistent chemical type, with sulfate less
than 10 percent and chloride ranging from 10 to 20
percent on a reacting value basis.
TARPEY VILLAGE AREA
Nitrate has substantially increased in ground
water of the Tarpey Village Area (Figure 6) in the
past, and there are a number of potential sources.
Thirteen wells have had nitrate over 25 ppm at
least once, and 6 of these wells have had nitrate
over 45 ppm. Tarpey Village proper presently has
municipal sewerage connections east of Clovis
Avenue, whereas septic tanks are used west of
Clovis Avenue. The area is bounded on the east and
northeast by extensive acreages of vines, peaches,
and pastures. Johnson et al. (1965) conducted a
subsurface drainage study of the San Joaquin
Valley. Variable portions of applied nitrogen in
agricultural areas were lost with the drainage wa-
ters. The nitrogen content of drainage water ranged
from 1.8 to 62.4 ppm, with a weighted average of
25 ppm, or 110 ppm nitrate equivalent. Sewage
treatment plants and wineries use percolation ponds
tor waste disposal and are other potential nitrate
sources.
The Clovis Sewage Treatment Plant has pro-
E SHAW iVEWUF
Fig. 6. Tarpey Village Area and wells of interest (circles)—
waste dischargers are cross-hatched.
vided primary treatment for essentially domestic
sewerage from the municipality of Clovis since
1955. Disposal of sewage effluent is by percolation
on about 30 acres west of Tarpey Village. Total
nitrogen content of the effluent was 28.0 ppm, or
123 ppm nitrate equivalent, in 1968. About 70
ppm nitrate were sampled in the effluent in 1963
and were apparently related to operation of the
trickling filters. Nitrate in the past several years has
averaged 10 to 20 ppm. The average effluent flow
is about 1.0 million gallons per day and in recent
years 2 wells near the plant have monitored the
highest nitrate contents reported in the F.C.M.A.
for pumping wells. Water from these wells has ex-
ceeded 120 ppm nitrate. Domestic wastes from the
eastern part of Tarpey Village are treated by Fresno
County Sanitation District No. 1, which was
formed in 1955. The average effluent flow is about
0.2 million gallons per day from an activated
sludge unit. The total nitrogen content in 1963
was 29.0 ppm, or 128 ppm nitrate equivalent. The
pond effluent is percolated from 5 acres of ponds
southeast of the Italian Swiss Colony Winery.
The Italian Swiss Colony Winery, or Allied
Winery, had a wastewater flow of 40 million gallons
in 1968. Disposal of wastewater is by land flooding
of about 110 acres south and east of the winery,
and disposal of clear water into the Gould Canal.
Wastewater analyses by the California Department
of Water Resources (1965) indicated potassium
content was 920 ppm, sulfate content was 177
ppm, sodium content was 102 ppm, and chloride
content was 41 ppm. However, no determinations
were reported for total nitrogen during the winery
season. The author took 2 samples of wastewater
from ponds of the Italian Swiss Colony Winery in
November, 1970. Total nitrogen content for one
sample was 100 ppm, whereas that for a second
sample was 250 ppm. These values have nitrate
equivalents of 440 and 1,100 ppm, respectively.
Winery wastewater seems to have a total nitrogen
content similar to that for meat-packing plants.
Winery wastewaters are a potential source of nitrate
in ground water that have been neglected in past
studies in the F.C.M.A.
Static water levels declined in the Tarpey
Village Area from the 1950's to 1962 or 1963.
This trend was reversed and rising water levels have
occurred from 1963 to the present. Depth to water
in 1969 ranged from less than 30 feet in the eastern
portion to more than 70 feet in the western por-
tion. The predominant direction of ground-water
flow beneath the Tarpey Village Area is southwest,
and the hydraulic gradient averages 25 to 30 feet
per mile. This area is in a transition zone between
the cobble and sand zones of the northern F.C.M.A.
149
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and the abundant clays to the south. Cobbles are
generally absent and a soil with no hardpan occurs
throughout much of the area. Transmissibility is
rather uniform and averages 180,000 gpd/ft.
Nitrate hydrographs show long-term increases
for most wells. However, wells perforated in deeper
parts of the aquifer had a constancy of nitrate.
Historical records indicate a substantial increase in
nitrate content occurred between 1958 and 1963.
The septic tank part of Tarpey Village was devel-
oped, the Clovis Sewage Treatment Plant was re-
activated, and the Fresno County Sanitation Dis-
trict No. 1 treatment plant was built during or
shortly prior to this period. Five wells with chloride
and nitrate hydrographs had a similarity of nitrate
and chloride short-term trends, as in the Figarden-
Bullard Area. However, 5 other well hydrographs
had nitrate short-term trends opposite to those of
chloride. The latter group of wells were at or near
the Clovis Sewage Treatment Plant and were
apparently affected by sewage effluent.
Analyses of samples of wastewaters and
ground water were plotted on a trilinear diagram.
Typical ground water in septic tank areas contains
less than 10 percent sulfate and less than 10 per-
cent chloride on a reacting value basis. Ground
water near the Clovis Sewage Treatment Plant has
sulfate ranging from 10 to 20 percent and chlo-
ride from 10 to 20 percent. Fresno County Sanita-
tion District No. 1 and Clovis Sewage Treatment
Plant effluent have similar compositions to the
latter ground-water samples. Italian Swiss Colony
Winery effluent has about 10 percent chloride and
30 percent sulfate. A trilinear diagram for ground
water in the Tarpey Village Area showed that septic
tank effluent, the Clovis Sewage Treatment Plant,
and the Italian Swiss Colony Winery were the
primary sources of nitrate. Some wells had one
primary source, whereas other wells apparently had
more than one nitrate source.
Seasonal nitrate analyses for District 8 wells in
1967, 1969, and 1970 showed substantial decreases
as the summer progressed. Virtually all of these
wells are on canal banks or nearby, and with the
limited hardpan development of the area, abundant
recharge from canals is a certaintv. An analysis ot
cr* "
aquifer penetration revealed a nitrate stratification
as in the Figarden-Bullard Area. However, equiva-
lent nitrate concentrations were about 40 feet
deeper in the aquifer beneath the Tarpey Village
Area. The primary reason for higher nitrate con-
tents at greater depths is the presence of nitrate
sources other than septic tanks. Ground water
moving from beneath these sources to wells in the
area follows flow paths that take nitrate deeper
into the aquifer.
On the basis of available data, wells at the
Clovis Sewage Treatment Plant, Clovis No. 8 and
No. 10, Well No. 8-1, and wells at the Palm Lakes
Golf Course have been primarily affected by sewage
effluent. Four of the 6 wells with nitrate over 45
ppm at least once in the Tarpey Village Area were
near the Clovis Sewage Treatment Plant. Wells No.
8-2, 8-6, and 8-4 have been primarily affected by
septic tank effluent. Wells No. 8-3 and 8-7 and a
well at the Italian Swiss Colony Winery have been
primarily affected by winery wastewaters. Non-
urban land immediately upgradient of Tarpey Vil-
lage is idle and underlain by ground water with
nitrate contents less than 15 ppm. There is a small
agricultural contribution to ground-water nitrate in
this area, because of the lack of nitrogen fertiliza-
tion for several decades. Nitrate from agricultural
areas further east is diluted by ground-water inflow
before reaching the Tarpey Village Area. The septic-
tank part of the Tarpey Village Area and the
-Italian Swiss Colony Winery are planned to be con-
nected to the Fresno sewerage system within the
next several years. After these connections, nitrate
content will decrease in most ground water ot the
area, but the Clovis Sewage Treatment Plant proba-
bly will continue to be an important nitrate source.
MAYFAIR-FRESNO AIR TERMINAL AREA
The Mayfair-Fresno Air Terminal Area (Figure
7) has a high septic tank density and previous
studies have related high nitrate contents in ground
water to septic tank effluent. However, a number of
potential sources are upgradient ot this area. The
R. 20 E. i R. 21 E.
Fig. 7. Mayfair-Fresno Air Terminal Area—waste dischargers
are cross-hatched.
150
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Clovis Sewage Treatment Plant, Italian Swiss Colo-
ny Winery, and Fresno County Sanitation District
No. 1 treatment plant were previously discussed.
Anhydrous ammonia is widely used on agricultural
lands immediately east of the Fresno Air Terminal
and ground water in this area had a nitrate content
ranging from 15 to 25 ppm in 1970. About 500 to
600 acres were also irrigated in or near the Fresno
Air Terminal in 1970. Nineteen wells have had
nitrate contents over 25 ppm and 6 of these wells
have had nitrate over 45 ppm at least once in the
Mayfair-Fresno Air Terminal Area.
The Guild Winery or Alta Vineyards Winery
had a wastewater flow of 16 million gallons in
1968. About four million gallons were disposed of
in Mill Ditch and through dry wells. This waste-
water had the lowest waste strength of samples
from the 3 wineries on Clovis Avenue sampled by
the California Department of Water Resources
(1965). Sampling of wells at the winery and within
one-half mile downgradient of the disposal ponds
indicated low nitrate contents in 1970. Although
part of this was due to the existence of moderately
deep wells, apparently the relatively small volume
of percolated wastewater minimized the contribu-
tion to ground-water nitrate.
The Gallo Winery had a wastewater flow of
50 million gallons in 1968. Disposal of all waste-
water prior to 1970 was by land flooding of about
260 acres south and east of the winery. This winery
has the highest wastewater flow of the 3 wineries
on Clovis Avenue; all of the water was formerly
percolated; and the waste has the greatest strength
of all 3 wineries. A sample of pond water was taken
by the author in June, 1970 prior to connection of
Gallo Winery to the Fresno sewerage system. Total
nitrogen was 410 ppm, or about 1,800 ppm nitrate
equivalent. Two of 3 wells sampled near the dis-
posal ponds had nitrate over 45 ppm.
Ground-water flow is primarily southwest in
the northern portion and west in the southern
portion. Depth to water in 1969 ranged from 60
feet in the southeastern part to 90 feet in the
northwest. Water levels declined from 1958 to
1965 at about 4 feet per year, but have risen 1 to 3
feet per year thereafter. Lithologic sections demon-
strate that this area is in a transition zone from the
sands and cobbles of the northern F.C.M.A. to
clays of the south. The area is generally free of
cobbles in the subsurface except for a lens in the
central portion. A shallow, thick clay occurs from
10 or 20 to about 60 feet beneath much of the
area.
Soils of the Mayfair-Fresno Air Terminal Area
are of the Madera Series. Most of the soil north of
East McKimey Avenue is Madera sand, which has
no hardpan. Hardpan in the remainder of the area
lacks the impermeable nature of that in the older
San Joaquin soils to the north and east. Transmissi-
bility of most of the aquifer is about 180,000
gpd/ft. However, a lens-shaped area in the vicinity
of East McKinley Avenue has a transmissibility of
370,000 gpd/ft.
Historic nitrate analyses show that all wells
sampled in 1951 had concentrations less-than 15
ppm. Nitrate contents had greatly increased by
1963. The number of wells with nitrate content
over 25 ppm remained relatively constant from
1963 to 1969. Eighteen hydrographs had long-term
increases in nitrate. Most of these hydrographs
were for wells with a cased depth of less than 150
feet. Six hydrographs had nitrate decreases, but
most of these records were for short periods. Wells
with decreasing nitrate trends were probably af-
fected by canal recharge during the wet years of
1967 and 1969. Fifteen hydrographs had constant
nitrate trends and most of these were for wells
cased to at least 150 feet depth. Fifteen well
hydrographs had nitrate short-term trends similar
to those of chloride. These well hydrographs have
the dominant trend of the Figarden-Bullard Area, a
trend related to septic tank effluent. Only 3 wells'
hydrographs had opposite nitrate and chloride
short-term trends, and these wells were down-
gradient from the Clovis Sewage Treatment Plant.
Seasonal nitrate analyses for 1967, 1969, and
1970 indicate consistent decreasing contents during
the summer, as in the Tarpey Village Area. This
feature is also due to canal recharge. An analysis of
aquifer penetration revealed a step-like pattern of
nitrate as in the Figarden-Bullard and Tarpey Vil-
lage Areas. However, few shallow wells in the May-
fair-Fresno Air Terminal Area have low nitrate
contents. Thus, there is some indication of a
"nitrate cap" as described by Stout, Burau, and
Allardice (1965) in San Luis Obispo County, Cali-
fornia. Several wells in the area have nitrate con-
tents too high to fit the step-like pattern. Two of
these wells are downgradient of the Clovis Sewage
Treatment Plant and 2 others are downgradient of
the Gallo Winery.
A trilinear diagram was prepared for samples
of wastewater and ground water in the Mayfair-
Fresno Air Terminal Area. The anion portion was
most useful and suggests that septic tanks have
contributed the majority of nitrate to the ground
water. This diagram and chloride concentrations
indicate downgradient movement of sewage efflu-
ent for at least 1 or 2 miles from the Clovis Sewage
Treatment Plant. Similar data indicate downgradi-
ent movement of winery wastewater from the Gallo
Winery ponds for at least 1 or 2 miles. Ground-
151
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water velocities are estimated to range from several
hundred to 1,000 feet per year in this area. The
downgradicnt effect of recharged wastewater is
limited by dilution and dispersion in the aquifer.
Most wells with high nitrate contents are in
the southern part of the area, and no wells with
high nitrate are in the central part. Hardpan exists
in some parts ot the northern portion and may
limit the percolation of high nitrate waters. Cobble
zones disperse and dilute the high nitrate recharge
waters in the central portion. Ground water in the
Mayfair-Fresno Air Terminal Area with nitrate over
25 ppm in 1969 covered an area larger than any
other part of the F.C.M.A., except near the Fresno
Sewage Treatment Plant. This situation is related to
the high density of septic tanks and the presence of
other nitrate sources. The absence of cobble zones
and impermeable hardpan favor higher nitrate con-
tents in ground water. The lower transmissibility,
as compared to the northern part of the F.C.M.A.,
also lessens the dilution of high-nitrate recharge
waters. Nearby upgradient agricultural lands con-
tribute some nitrate to the urban area. The Maytair-
Frcsno Air Terminal Area septic tank portions be-
gan conversion to the Fresno sewerage system in
1970, and the Guild and Gallo Wineries were also
connected in summer, 1970. The future nitrate
situation will greatly improve in this area with
these connections, but the Clovis Sewage Treatment
Plant will probably continue to be an important
nitrate source to the northeastern portion.
DOWNTOWN FRESNO AREA
The Downtown Fresno Area (Figure 8) has
been sewered since 1891 and no sewage treatment
plants are within several miles of the area. Settle-
ment occurred in the late nineteenth century, and
most of the early industrial development occurred
here. Upon careful examination, a number of
R ZOE.
Fig. 8. Downtown Fresno Area—present and former waste
dischargers are cross-hatched.
potential nitrate sources can be found in or near
the Downtown Fresno Area. Urban parts of the
city surrounding the area used septic tanks many
years ago. The townsite ot Calwa, which covers
about 500 acres, presently is unsewered and is
one-half mile southeast of the area. The Mayfair-
Fresno Air Terminal Area is also unsewered and
extends to within one-half mile of the Downtown
Fresno Area. Ten wells have had nitrate over 25
ppm at least once and 2 of these wells have had
nitrate over 45 ppm. Industry and agriculture also
comprise potential sources of nitrate to the area.
Meat-packing plants have high nitrogen wastes.
The concentration of organic plus ammonia-nitro-
gen in such waters is quite high, ranging from 100
to 300 ppm, or 440 to 1,320 ppm nitrate equiva-
lent (American Water Works Association, 1967).
Two meat-packing plants are within 1.5 miles and
southwest of the area. Historically, a number of
industries used independent waste disposal facilities
prior to connection to municipal sewerage systems.
Roma Winery has a wastewater flow of 1.0 million
gallons per day and is at the southeastern corner
of the Downtown Fresno Area. This winery was
unconnected until 1936. Mont LaSalle Vineyards
or Christian Brothers Winery is one mile east ot the
Roma Winery and was unconnected prior to 1953.
Both wineries may have contributed substantial
amounts of nitrate before connection to municipal
sewerage systems. Several chemical industries used
independent waste disposal facilities ir. 1969, but
wastewater flows were too small to affect wells
thousands of feet distant.
Many cooling water return wells are in or near
the Downtown Fresno Area. A previous study
stated that water quality was unaffected by the
cooling process (California Division of Water Re-
sources, 1952). However, the highest nitrate con-
tents in the F.C.M.A. in 1951 were sampled near 2
recharge wells. High nitrate ground water also was
found near the Fresno County Hospital cooling
return well in 1970. Apparently, either recharge
water is enriched with nitrate derived from the
refrigerant, or other sources of nitrate have been
injected in some of these wells. The Fresno Sewage
Treatment Plant is about 3 miles southwest of the
Downtown Fresno Area. The California Depart-
ment of Water Resources (1965) assumed that
sewage effluent from this plant had not reached
the Downtown Fresno Area by 1963. Most histori-
cal water level contour maps have shown a slight
gradient towards the treatment plant from down-
town Fresno. However, these maps have been based
on only a few wells, and were usually drawn for
December conditions. Ground-water elevation con-
tours for the fall of some years, such as 1951,
152
-------
show either a flat water table or a gradient toward
the Downtown Fresno Area. Northeasterly move-
ment of ground water from the Fresno Sewage
Treatment Plant toward the urban depression cone
was possible during summer pumping conditions.
Agricultural areas southwest of the Downtown
Fresno Area may contribute nitrate to ground
water, as anhydrous ammonia is in wide use. Large
dairies are additional sources of nitrate in this
vicinity. The Fresno County Disposal Yard is within
1 mile of the Downtown Fresno Area, and solid
waste disposal sites are potential nitrate sources.
Several old cemeteries lie northwest of the area and
may have contributed nitrate decades ago when
waterlogging occurred over much of the F.C.M.A.
The extreme southern portion of the urban
cone of depression in the F.C.M.A. is beneath the
Downtown Fresno Area. Ground water can poten-
tially enter the area from almost any direction.
Depth to water in 1969 ranged from 50 feet in the
southwest to 83 feet in the northeast. No major
canals traverse the area except for Dry Creek Canal
at the northwest corner. Water levels declined until
1966, and have stabilized up to the present. The
Downtown Fresno Area has abundant clays in the
subsurface, especially below several hundred feet
depth. A thick clay occurs over much of the area
at a depth interval of 10 or 15 to about 75 feet.
Soils are of the Madera Series, and Madera sand
occurs throughout much of the area. Transmissi-
bility is highly variable and ranges from 60,000
gpd/ft in the nortrmest to 370,000 gpd/ft in the
northeast.
Almost all wells in the F.C.M.A. with nitrate
contents over 15 ppm in 1951 were in or near the
Downtown Fresno Area. This was prior to extensive
development of suburban areas on septic tanks and
nitrogen fertilization on agricultural areas. Wells
with nitrate over 25 ppm in 1958 were in an
elongate area! distribution, which trended north-
east-southwest. Significant amounts of chloride are
present in ground water of the Downtown Fresno
Area. This is in contrast to the Figarden-Bullard,
Tarpey Village, and Mayfair-Fresno Air Terminal
Areas.
Most wells with iong-term nitrate hydrographs
have either decreasing or constant trends. Short-
term chloride and nitrate trends were similar for 5
weii hydrographs, but opposite for 5 others. Sea-
sonal nitrate analyses for 1969 and 1970 showed
both increasing and decreasing contents as the
summer progressed. An analysis of aquifer penetra-
tion showed no stratification of nitrate as in septic
tank areas of the F.C.M.A. However, there was a
lack of data for aquifer penetrations of less than 8O
feet. Many wells with aquifer penetrations ranging
from less than 60 to more than 160 feet had nitrate
contents between 15 and 25 ppm. This distribution
suggests that nitrate did not originate from a sur-
face source in the immediate vicinity of the
Downtown Fresno Area. A trilinear diagram for
ground water in the area demonstrated at identical
composition to ground water at the Fresno Sewage
Treatment Plant.
Several wells with nitrate content over 15
ppm are within one-half mile of cooling return
wells. Two wells with nitrate content over 1 5 ppm
are near a meat-packing plant. One well with nitrate
content over 15 ppm is located between the Roma
Winery and Mont LaSalle Vineyards Winery. Two
wells with nitrate content over 15 ppm are near
septic tank areas. However, there are at least 5 wells
with nitrate over 15 ppm for which a source is
not immediately apparent. Several facets of the
nitrate distribution in ground water of the Down-
town Fresno Area should be explained. Key factors
are the relatively high nitrate contents of the
1950's. the high chloride content, the decreasing
long-term nitrate trends, the abundance of opposite
nitrate and chloride short-term trends, the presence
of nitrate in concentrations above the background
level at considerable depth in the aquifer, and the
trilinear plot for ground water.
Water samples were collected from many wells
in July and August, 1970, in the area between
downtown Fresno and the Fresno Sewage Treat-
ment Plant. Chloride was analyzed by the Mohr
titration method utilizing a Hach field testing kit.
Zones of chloride content greater than 25 ppm
were delineated (Figure 9). The largest zone ex-
tended from the Fresno Sewage Treatment Plant
northeast to the Downtown Fresno Area. Smaller
zones were near the Clovis Sewage Treatment Plant,
the Gallo Winery, and the Fresno County Hospital.
Chloride content was also greater than 45 ppm in
the smaller zones. The highest chloride contents in
F.C.M.A. ground water in 1970 were monitored at
the Fresno Sewage Treatment Plant.
Historical records in Fresno state that water-
logging occurred at the treatment plant site in the
earlv 1900's This problem was solved by ground-
water pumpage at the plant site and in the nearby
urban area in the 1920's. it is significant that the
original treatment plant site was one mile east of
the present plant, and thus one mile closer to the
Downtown Fresno Area. Sewage effluent from the
Fresno Sewage Treatment Plant has played an
important part in recharge to ground water of the
F.C.M.A. since 1891. The northeasterly movement
of ground water beneath the treatment plant was
initiated with the greatly increased pumpage in the
urban area between 1910 and 1920. Some wells in
153
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Fig. 9. Distribution of chloride in ground water in 1970—
contours are in parts per million and circles are locations of
sampled wells.
the Downtown Fresno Area were monitoring fairly
hiilh chloride contents by 1930. Historical chloride
analyses from that time to the present show an
elongate pattern ol wells \\ith high chloride con-
rents. 'The northeast-southwest trend of the high
chloride zone in the Downtown Fresno Area im-
plies .1 source TO the northeast or southwest. How-
c\er, as no hisih chloride source ot large volume
occurs to the northeast, the source must he to the
southwest.
The relatively high nitrate contents ot the
195()\ were related to ground-water intlow for
several decades from the vicinity ol the Fresno
Scwaee Treatment Plant. 1'his inflow was accentu-
ated bv urban water level declines. However, by
!°65 v. ,iter A-\-, .s ;-.ad stabilized ,n the Downtown
l-rcsjio Area and : "it low from t!u southwest dimin-
-iied. Ihus. decreasin_ trend-, have occurred ior
m.mv nitrate hvdroijraphs. espcuallv over the past
uec.uk. I he hi.,a ch!o<->dc contents of the Down-
\\ n Fresno ,\;c;: .a c a direct ici.e^uon ot r-C'1. age
efliuent. as chloride i> ncarlv ai. ideal tracer in this
cm ironmcm. I'he abundance ot opposite nitrate
and chloride short-term trends and the trilinear
,-/ )t of ground w.rer confirm that the Fresno
Srw.iuc I reatment Plant has been the primary
source of nitrate. Nitrate at considerable depths in
the aquifer was caused by movement of nitrate
from a source several miles distant. Flownet con-
siderations demonstrate that sewage effluent from
the mound beneath the plant would tend to move
into deeper portions ot the aquifer.
Septic tank effluent from the Mayfair-Fresno
Air Terminal Area has reached the northeastern
portion of the Downtown Fresno Area and has
been the dominant nitrate source since about 1963.
Septic tanks at Calwa have contributed some
nitrate to the southeastern part of the area. Winery
wastewaters have likely contributed nitrate to
ground water in the southeastern portion of the
area. Meat-packing plants have contributed nitrate
near the southwestern portion. However, the domi-
nant source has been the Fresno Sewage Treatment
Plant.
With the planned conversion of septic rank
areas and industries on independent waste disposal
units to municipal sewerage systems, it is inevitable
that nitrate conditions will greatly improve \\ ;th--i a
period of years in most ot the F.C.M.A. However.
in the vicinity of the urban depression cone, Citrate
contents will likely increase. This is due to th<'
planned concentration ot almost jll ot the rot.il
nitrogen load of the urban area at one site. I nU
-------
sewage effluent in the aquifer and water samples
from wells plot in a characteristic part of the tri-
linear diagram. Short-term trends for chloride and
nitrate hydrographs are commonly opposite near
sewage treatment plants in the F.C.M.A.
The highest nitrate contents occur in the
upper 50 or 60 feet of the aquifer beneath septic
tank areas. Nitrate stratification is obscured when
other sources are present, due to the derivation of
nitrate from nearby areas by ground-water inflow.
Trilinear diagrams for constituents in ground water
and short-term nitrate and chloride trends in septic
tank areas differ from those for ground water
affected by sewage effluent.
An analysis of two high nitrate areas near the
Fresno Air Terminal indicates septic tanks con-
tributed most of the ground-water nitrate. How-
ever, wineries and the Clovis Sewage Treatment
Plant are significant local sources. Winery waste-
waters were sampled and had a total nitrogen con-
tent ranging from 4 to 10 times that found in
typical domestic sewage. Wineries have been im-
portant sources of ground-water nitrate, as they
have existed since the early 190()'s. The agricultural
contribution of nitrates to ground water in the
urban area is small due to dilution as downgradient
movement occurs.
Ground water beneath the Downtown Fresno
Area is in a significant hydraulic depression cone.
Extensive northeasterly flow of ground water from
the mound beneath the Fresno Sewage Treatment
Plant took place for many decades. Moderate
concentrations of nitrate occur at depth in the
aquifer and are related to the inflow of sewage
effluent from a source several miles distanr. Al-
though other sources have contributed nitrate to
the ground water, sewage effluent is the dominant
source as indicated by chemical and hydrologic
data.
Twenty-six wells in the F.C.M.A. have sam-
pled nitrate over 45 ppm at least once since 1947.
Seven of these wells have been near the Fresno
Sewage Treatment Plant. Six wells west and south-
west of the Fresno Air Terminal have sampled
nitrate greater than 45 ppm at least once. Five wells
in the vicinity of the Clovis Sewage Treatment
Plant had nitrate exceeding 45 ppm at least once.
Other ground water with nitrate greater than 45
ppm in the F.C.M.A. was in the Downtown Fresno
Area, in septic tank portions of Figarden-Bullard
Area, in the agricultural areas north and east of
Fresno, and near the Gallo Winery.
REFERENCES
American Water Works Association. 1967. Sources of
nitrogen and phosphorus in water supplies. Journal of
American Water Works Association, Task Group
Report, March, 1967, pp. 344-366.
Behnke, J. J., and E. E. Haskell. 1968. Ground water nitrate
distribution beneath Fresno, California. Journal of
American Water Works Association, v. 60. no. 4, pp.
477-480.
California Department of Water Resources. 1965. Fresno-
Clovis metropolitan area water quality investigation.
Bulletin 143-3.
California Division of Water Resources. 1952. Investigation
of cooling water return, City of Fresno. Report to
Central Valley Regional Water Pollution Control
Board, Project no. 52-5-10, 44 pp.
Jenks, J. H., and P. L. Adamson. 1968. Metropolitan area
wastewater treatment and disposal facilities. Report
to City of Fresno, Department of Public Works.
Johnson, W. R., F. Illichadieth, R. M. Daum, and A. F.
Pillsbury. 1965. Nitrogen and phosphorus in tile
drainage effluent. Soil Science, v. 29, p. 287.
Nightingale, H. I. 1970. Statistical evaluation of salinity and
nitrate content and trends beneath urban and agri-
cultural areas—Fresno, California. Ground Water, v. 8,
no. l,pp. 22-28.
Page, R. W., and R. A. LeBlanc. 1969. Geology, hydrology,
and water quality in the Fresno Area, California. U. S.
Geological Survey Open-File Report, Menlo Park,
California, 189 pp.
Schroepfer, G. J., and R. C. Polta. 1969. Travel of nitrogen
compounds in soils. Sanitary Engineering Report
172-5, University of Minnesota.
Stout, P. R., R. G. Burau, and W. R. Allardicc. 1965. A
study of the vertical movement of nitrogenous matter
from the ground surface to the water table in the
vicinity of Grover City and Arroyo Grande, San Luis
Obispo County. Report to Central Coastal Regional
Water Pollution Control Board, 51 pp.
DISCUSSION
The following questions were answered by Kenneth
D. Schmidt after delivering his talk entitled "Nitrate
in Ground Water of the Fresno-Clovis Metropolitan
Area, California."
Q. Can you describe the hardpan geologically?
A. This hardpan has been described by M, G. Croft
and R. J. Janda of the U. S. Geological Survey as
part of a study of the alluvial formations of the
eastern San Joaquin Valley. It is in the oldest soil of
the area, is cemented by iron salts, and belongs to
the noncalcic brown soils that occur in the eastern
part of the San Joaquin Valley. The hardpan is
composed of firmly cemented soil particles, and is
dense and impervious. It has a low humus content
and contains no alkali.
Q. How did the nitrate (NO~2), ammonium, and
organic nitrogen vary with the nitrate distributions?
A. These are important parameters to consider in
the ground water besides nitrate. There is less than
0.1 ppm ammonium or nitrate in the aquifer under-
155
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neath the septic tank areas. At the Fresno Sewage
Treatment Plant there are some ammonia contents
between 0.5 and 1 ppm. There is an inverse relation
between ammonia content and nitrate content on a
seasonal basis. Some wells have shown as much as 5
ppm ammonia, which is an indication that the
ability of these soils to continue retaining the
ammonia form has perhaps been reached. Nitrite
contents have generally been less than the limits of
detection in all ground water of this area, as sam-
pled by pumping wells. Organic nitrogen has not
been tested for to a large extent, but contents are
below the limits of detection.
Q. Did you determine any oxidation potentials?
A. No, I didn't, and perhaps this would be a very
important thing to do. There are several areas
where investigators have actually worked with
this, such as Stewart and others in Colorado.
Apparently, there is good correlation between
oxidation potential and nitrate above the water
table in some areas and a poor correlation in other
areas. Obviously, studies in the unsaturated zone
would be necessary to completely understand
nitrate in ground water of the Fresno area. Oxida-
tion potential would be an important parameter;
however, my analysis was confined primarily to
water in the aquifer.
Q. Has there been any plan to line evaporation
ponds at the Fresno Treatment Plant? Are many
of these ponds already lined?,.
A. No ponds are lined at present. About 80 to 85
percent of the effluent disposal at the Fresno City
Sewage Plant is by percolation. If the ponds are
lined, then a much Larger waste disposal problem
will occur. Approximately 1440 acres of percola-
tion ponds are necessary at present and on the
average of 10 percent of the effluent is used for
irrigation on nearby farms. There is some evapora-
tion also, which makes up the remainder. I think
the best solution will not be to line the ponds but
to continue percolation of the water. The solution
involves the nitrogen compounds themselves, be-
cause recent literature suggests that with refined
technology we are learning how to control the
total nitrogen content of effluent. The City of
Tucson Sewage Treatment Plant has been able to
substantially decrease total nitrogen contents of the
effluent in recent years.
Q. Ken, you mentioned the use of agricultural
fertilizers. Are super-phosphates used in this area?
Also, what fluoride levels were found in the ground
water?
A. About 90 to 95 percent of the agricultural
fertilizer used in this area is anhydrous ammonia.
Farmers use virtually no significant amounts of
super-phosphates to my knowledge. Fluoride levels
are below 0.1 ppm in this whole area except in
two septic tank areas where they use fluoridation
units. Fluoride levels ranging from about 0.1 to
almost 1 ppm have shown up in the ground water
within 3 to 5 years since installation of these
fluoridation units.
Q. Here's another one on agricultural sources and
nitrates. To what extent have agricultural sources
of nitrates been examined in the San Joaquin Val-
ley?
A. Many studies along this line have been done. If
one looks at the nitrogen literature not only in the
San Joaquin Valley but elsewhere in the country,
one may conclude that prejudice has been evident
among some investigators. In the Fresno area, agri-
cultural workers have neglected the wineries, and
have generally not considered the effect of ferti-
lizers on ground water near urban areas. One com-
mon argument is that plants use all of the nitrogen
in the fertilizer. I think we have to recognize that
the true position is somewhere between no effect
and a substantial effect. That is, most farmers
don't want to apply fertilizer that would be
leached in great amounts. A farmer is going to try
to be efficient, but he usually is not going to be
100 percent efficient and recover all of the nitro-
gen added. Agriculture contributes to nitrate in irri-
gated areas near my urban study area. The nitrate
contents beneath agricultural areas varied with the
transmissibility and other factors, and ranged from
15 to 25 ppm where the transmissibility was lowest.
So in the Fresno area, agriculture near the urban
area is not really causing nitrates that are over 45
ppm.
One of the important problems now in Cali-
fornia is how to get rid of the nitrate that is going
to be in the California master drain when it is built.
They have done experiments at Firebaugh, which is
northwest of Fresno, and have been quite success-
ful in denitrification. About 25 ppm nitrate is the
average nitrate content in irrigation return water
in the San Joaquin Valley. Now, in some areas
nitrates occur in amounts over the limit and it is
due to agriculture. Many factors must be con-
sidered, such as fertilizer practice, irrigation, aquifer
characteristics, and well construction.
Q. / have 2 questions here I think are similar to
what you're discussing. Has spray irrigation been
considered to recycle the nitrate back to the agri-
cultural area? Aren't these high nitrate waters
worth something as an irrigation water source?
A. This is something that people working near
Phoenix, Arizona have considered. Herman Bouwer
156
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presented a paper on this at the Arizona Academy
of Science meeting in April. It seems logical to
consider using sewage effluent for its nutrient
value. One major problem is that in the future we
are going to, in places such as Arizona and Cali-
fornia, grow more and more high yield crops. A
high nitrogen load all the time is not desirable on
these crops because of rank growth of the vegeta-
tion. However, effluent may be used on field
crops such as safflower or may be diluted and used
on many crops.
The idea in Phoenix is to have sewage plants
along a dry stream bed, with a number of percola-
tion basins. Water will be recharged and later
pumped by wells after moving a sufficient distance
through the soil. They believe that by operating the
ponds in a certain manner, such as controlling the
aerobic vs. anaerobic conditions, one can get
almost any nitrate content desired in the recharged
effluent. Hopefully, they will be able to deliver
the nitrate load that the farmer wants when he
wants it. One can imagine that with different crops
growing and a number of different farmers, this is a
formidable task. The concept of utilizing the nutri-
ent value of nitrate in well water or sewage effluent
is worthwhile and will eventually be perfected.
Q. In your discussion, one person wants to know
how did you eliminate lawn fertilizers as a nitrate
source in the suburban septic tank areas? Was there
no early fertilizer usage in the Fresno area?
A. Let me answer the second part of that question
first. The important point about fertilizers is the
drastic change that occurred between 1950 and
1970, when nitrogen fertilizer use increased by 600
percent. Fertilizer use in this area was small prior
to 1950. As regards lawn fertilizers in the septic
tank areas, that's a very good question. In the
septic tank areas where there is hardpan, nitrogen
compounds will not percolate and generally will
not enter the ground water, in other areas where
the impermeable hardpan is absent, nitrates could
build up in the ground water. I did not scientifically
eliminate lawn fertilizers as a source, but I think a
simple calculation, if we knew the amounts used,
would show only small accretions to the ground-
water nitrate.
Q. Shouldn't the inverse relationship you noted
be between nitrate content and the specific ground-
water discharge rather than the transmissibility
alone?
A. This is a point that is theoretically sound. My
concept is that we are adding nitrate at the land
surface, and that it will be diluted in relationship
to the transmissibility of the aquifer. Of course,
water flows through the aquifer based not only on
transmissibility, but on the hydraulic gradient and
width of flow. However, the gradient tends to be
uniform in each one of the small areas studied.
Thus nitrate content on a local scale does depend
primarily on the transmissibility, as the gradient is
rather uniform.
Q. What percent of irrigation water applied to
fields is returned to ground water by infiltration?
What percent is this of the total recharge?
A. Let's consider eastern Fresno County and the
agricultural areas in it. The best estimates, which
are fairly reliable, indicate that farmers are apply-
ing about 4 to 5 acre-feet per acre per year. The
consumptive use of the crops growing there is
about 2.5 acre-feet per acre per year. The percent
of applied water that returns to the ground water
is thus about 30 to 40 percent.
Q. Let me finish the other part of the last
question—what percent is this of the total recharge?
A. I don't have the vaguest idea. We don't really
have valid estimates of the canal recharge and other
components of the water budget. Return flow
comprises one of the major unknowns in many
water budget studies in semiarid and arid environ-
ments.
Q. How about naturally occurring nitrate as in
some of the salt pans in the inner mountain basins,
such as Owens Valley, Death Valley, etc.?
A. J. H. Feth, in 1966, summarized data on
nitrogen compounds in water. He points out that
natural sources of nitrate are associated with caves,
playa deposits and caliche. None of these occur in
or near Fresno's urban area.
Q. Do you think that your sampling frequency is
sufficient to really establish confidence in water
quality trends?
A. The frequency you're probably referring to is as
shown on the water quality hydrographs. I more or
less financed this study myself; for this and other
reasons, I wanted to take an area where the data
was available and see what could be done. Now it's
probably easier to go out with a large sum of mon-
ey, take a large number of water samples, and have
good data to interpret. However, as a practical
problem, we should sometimes force ourselves to
us.e available data. I think the trends are meaning-
ful. I looked at all available analyses for specific
wells and used judgment to cast out erroneous or
atypical values. There are many problems, such as
laboratory errors, pumping time, contamination,
and time between sampling and analysis. Of course,
different methods have been used at different
times. Some of these problems cannot be solved
157
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because these are the only historical data available.
Because these trends could be related to actual
waste disposal operation at the land surface and
hydrogeologic factors, I would argue that they are
meaningful. However, they are by no means the
ultimate—and more detailed sampling is necessary
for precise interpretation.
Q. This might be along the same line, Ken. It says
here the almost perfect positive correlation of
nitrate and chloride in septic tank areas and the
almost perfect negative correlation for sewage plant
effluent hardly appear to be just chance occur-
rences. Can you speculate about any casual
mechanisms?
A. The similarity of chloride and nitrate behavior
in water, of course, is well documented in the
literature and would be expected from geochemical
and other considerations. Chloride and nitrate are
both soluble and mobile in most ground-water
systems. There is a correlation between the chloride
and nitrate in septic tank areas because chloride
and nitrogen compounds are in the effluent, and
these ions have similar geochemical characteristics
in the aquifer; they are both soluble and they are
not adsorbed or exchanged.
The opposite trends are more difficult to ex-
plain. An explanation may be somewhat theoreti-
cal, but it is interesting. There was evidence of
denitrification between the Fresno Sewage Treat-
ment Plant. I believe that many workers have over-
emphasized denitrification and have used it when
the other items didn't balance out. I believe that if
one considers chloride or some other ion that does
not undergo denitrification or nitrification, valu-
able conclusions can be drawn. Chlorides-in the
ground water for quite a distance around the
sewage treatment plant are generally the same as in
the effluent. This indicates that there is little dilu-
tion of recharged effluent near the plant. This is
true because the quantity of effluent is so large,
about 25,000 acre-feet per year. However, nitrates
are not correspondingly high in the same area,
although some high contents do occur. Denitrifica-
tion completely eliminates nitrogen compounds, as
they go off as gaseous forms and are no longer in
the water. Nitrate would tend to be lower, gener-
ally due to the anaerobic conditions developing in
the area, and denitrification.
Another alternate could be related to a con-
cept discussed last year in the Journal AWWA.
Malhotra and Zanoni discussed the interference
effect of high chloride ion contents on nitrate
determination. High chloride contents near sewage
plants could cause interference with the phenoldi-
sulfonic method for nitrate determination. Thus
with higher chlorides, nitrates may be erroneously
low in some cases.
Q. Were bacterial analyses made on water so
obviously contaminated by primary waste effluent
from the Fresno Treatment Plant?
A. Bacteriological sampling is something I did not
get involved with to a great extent. There are only
1 or 2 wells in the urban area that have shown
biological contamination. This is largely, in my
opinion, due to the regulations that are imposed
by the county for septic tank construction, that
the wells are generally deep, and are not usually
open in the upper 40, 50 or 60 feet of the aquifer.
I am not familiar with biological sampling near the
Fresno Sewage Treatment Plant.
Q. Could a source of nitrate in downtown Fresno
be leaking sewers? Could uniform vertical distribu-
tion be attributed to large vertical flow components
associated with pumping, particularly in the central
portion of the cone of depression?
A. As for the first question, there were some areas
not near sewage plants where chemical data point-
ed to sewage effluent as the source. A possible
explanation would be related to leaking sewers.
However, I made no positive correlation; in the
future, it might be possible to do this.
In regard to the uniform vertical distribution—
my reasoning is that effluent has moved from a
mound beneath the Sewage Treatment Plant toward
downtown Fresno. This water would spread out in
a vertical sense, as one can visualize by flownet
consideration. Hence, no stratification occurs as in
the septic tank areas. The idea that the uniform
distribution of nitrate is due to vertical flow is a
good one, except for the lithology. The alluvium in
that area contains a number of clay layers, much
more than in any other part of the metropolitan
area. Vertical flow would be greatly restricted, but
still possible. There is a lot of pumping in the
urban depression cone, and there may be a relation
to distribution. But there is overwhelming evidence
for the case I have presented. Historical nitrate and
chloride data, water levels, trilinear diagram plots,
and chemical hydrographs indicate movement of
effluent from the Fresno Sewage Treatment Plant.
Perhaps the most conclusive data are the high
chloride contents between the plant and the down-
town Fresno area.
158
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The Use, Abuse and Recovery of a Glacial Aquifer
by Edward M. Burr
ABSTRACT
The inter-relationships between an industrial plant
and a shallow sand aquifer of glacial origin are described.
These relationships include industrial and potable water
supplies, industrial and human waste water disposal systems,
the hydraulics of the pollution of the ground-water aquifer
and the types of corrective actions taken to re-establish the
wise use of the ground-water resource. Also reviewed are the
ground-water movement-quality relationship, veil designs,
method of drilling, well redevelopment and ground-water
recharge.
INTRODUCTION
In the oast few years, since the general public
discovered ti:_ v.se, if not the literal definition, of
the words "ecolog}'" and "environment" many
industries of this nation have received "black eyes."
Some are deserved, but as in everything else, there
needs to be a balance of perspective. A purpose of
this paper is to illustrate the efforts of one manu-
facturer to maintain a peaceful coexisicnre with
the environment. The efforts have spanned almost
fifteen years—during which time scientists ;/>m
public agencies and private concerns, administra-
tors, engineers, architects and production personnel
have worked together, agreed and disagreed, but
have achieved the goal of preserving the environ-
ment.
Another purpose is to illustrate the inter-
relationships among the ground disposal of wastes,
the ground-water supply and well design, construc-
tion, and methods necessary to affect rehabilita-
tion. While the specific information given is related
to a single site, some of the conclusions drawn
reflect experiences with other similar projects.
The firm involved is a manufacturer who pro-
duces chemical intermediates related to the phar-
maceuti<" i! anJ agricultural industries. Some of the
products -trf basic, while others are finished chemi-
cal nrocacts of hlihiv complex, composition. The
corporation began on a small scale about fifteen
years ago. The corporate capability and product
diversifies ion rapidly increased and in time the
companv nv.Mcea \\ith a major national corporation
of international repure.
GEOHYDROLOGIC SETTING
The site is in Michigan and is situated within
a surface watershed of approximately 12 square
miles (see Figure 1). This shed is tributary to a
larger watershed, shown as Creek "B," which
eventually drains into one of the Great Lakes.
aPreiv;-,,ed at uie NiatK.i.a! CrounU Water Quality
Symposium, Denver, coluuido, August Js-J/ 19< 1.
^Geologist, Williams & '\,"ks, 250 Michigan Street
N.E., Grand Rapids, Michigan 49503.
Fig. 1. Schematic location map.
The company chose the sire because it offered
access to a major population center, a large labor
market, an abundance of ground water and reason-
able isolation from intense development. The
original facilities are shown in Figure 2. The major
structures consisted of one building to house ad-
ministrative offices, laboratory and maintenance
facilities; another buila;ng for production; and a
series of ponds for the ground disposal of cooling
and waste waters.
The potable and industrial water-supply needs
were originally met by a single well tapping the
unconsolidated glacial sands. This tubular well was
6 inches in diameter and supplied approximately
50 gallons per minute. Water storage and pressure
modulation was accomplished by a hydropneumat
ic tank.
A septic tank and tile field system adjacent to
the administration building accommodated the san-
itary wastes. Since both industrial and human.
Bastes were disposed to the ground, shallow ob-
servation wells were installed :--'tween the ad-
ministration building and the nenivst residence. The
responsible regulatory agency required the periodic
Dimpling of the observation well waters tor possible
ground-water pollution.
The growth of the company led to a staged
expansion program to develop the site as shown in
159
-------
Fig. 2. Schematic of original site development.
n
.
u
ca*t.*e <#u*r
... 00s-'
0
Fig. 3. Schematic of current site development.
Figure 3. However, during this expansion, pollution
of the ground water was detected.
At that point in time, it was necessary that the
company accomplish the following:
1. Develop a bacterially and chemically safe
water supply for their personnel and the production
processes.
2. Contain the pollution within the bound-
aries of their property.
3. Prevent additional pollution by developing
suitable waste water treatment processes.
4. Restore the quality of damaged ground
waters.
5. Maintain and expand the manufacturing
capabilities of the firm.
In the past, the priority of these needs would
assume a different order, depending upon the
individual firm involved. In today's complex soci-
ety and in light of modern science and technology,
it is necessary that all be accomplished simultane-
ously.
The plant site lies within a large lake plain
ancestral to the present Great Lakes. As such, the
surface soils are sandy lake beds. "The sand deposits
range from 60-120 feet thick,
The surface watershed and 'he ground-water
watershed are nothydrologically identical. Original-
ly the ground watershed was larger than the surface
watershed. The initial static water level of the water
table was approximately 5 feet below the land
surface.
Figure 4 indicates the original direction of
ground-water flow within the unconsolidatcd glacial
aquifer. The ground disposal of industrial waste
water up the hydraulic gradient from the original
well in conjunction with the company's use of
water, modified the original direction ot flow and
resulted in the pollution of the water supply. Thc
initial observation wells did not show the pollution
of the aquifer because the waste water was inter-
cepted by the well which furnished the company's
total water supply.
The records of deep wells surrounding the site
indicated the presence ol another aquifer. This
aquifer lies within the bedrock formation and is of
limited thickness and area! extent. A few nearby
domestic wells tapped this aquifer. Water samples
from those wells indicated a higher mineral content
than was found in the water from the sand aquifer.
Fig. 4. Original direction of ground-water flow.
160
-------
However, the degree of mineralization was within
United States Public Health Service limits for pota-
ble drinking water purposes. The capability of the
consolidated aquifer to supply water was explored
and found to be significantly less than that of the
unconsolidated aquifer.
The deeper bedrock formations include shales,
limestones, dolomites and sandstones. Where satu-
rated, these rocks contain saline water. Local de-
posits of petroleum and natural gas have been
found in some of these sedimentary rocks. Beneath
the sequence of sedimentary formations, igneous
and/or metamorphic rocks occur. The basement
rocks lie approximately one mile below the surface
of the land.
From the standpoint of potable and industrial
water supply, the upper 120 feet of the earth's
mantle offer the only reasonable supply at this site.
The deeper bedrock formations are of value
only for consideration as disposal reservoirs for
highly concentrated industrial waste waters. The
relationship between the static water level, high
specific gravity of the native brines within the bed-
rock formations and the low specific gravity of the
waste waters to be discharged make it theoretically
possible for disposed waste waters to migrate
upward by means of unrecorded or improperly
plugged wells into the fresh water aquifers. The
uncertainties related to natural fracturing between
the various formations also cause a logical hesitancy
on the part of regulatory agencies and consultants
to recommend deep well disposal. For these rea-
sons, waste water disposal into the bedrock forma-
tions less than 3,000 feet below the land surface is
not recommended in this area. However, the bed-
rock formations below 3,000 feet are suitable for
limited storage of waste waters.
INVESTIGATIONS
Studies of the industrial wastes involved de-
tailed, in-plant surveys of the chemical character of
the various waste streams and their treatability. As
is often the case, the studies revealed that more
thari 90% of the waste water was cooling water
which was unimpaired except for a slight increase
in temperature. It was judged that this water was
readily amenable to return to the ground for
reuse. Approximately 5% of the waters were
impaired and could be treated by available methods
and discharged to surface waters. Approximately
2'/2% of the waste waters were of human origin and
could be treated with ease. The remaining 2l/2% of
the water was highly concentrated, highly complex
industrial waste water. Further investigation indi-
cated the latter could be treated by incineration
and/or deep well disposal.
At the time of the study, the volume of the
most obnoxious waste water totaled 5 to 10 gallons
per minute. Projections based on the anticipated
expansion indicate the volume will not exceed 50
gallons per minute.
Concurrent with the in-plant waste water in-
vestigations, treatability studies of the contami-
nated ground waters were conducted, and new
potable and industrial water supplies were devel-
oped. The investigation of the extent of ground-
water pollution and development of new supplies
involved construction of a series of \1A inch diame-
ter observation wells tapping the upper and lower
portions of the sand aquifer. These wells permitted
measurement of water levels, sampling of the
ground waters, delineation of the area of the
ground-water contamination and definition of the
aquifer hydraulics. The latter data, together with
the separation of the various waste streams, per-
mitted construction of a new ground disposal
recharge pond for the cooling waters and individual
treatment of the contaminated industrial waste
waters. The locations of purge wells, observation
wells, production wells, cooling water return site
and waste water ponds are shown in Figure 5. The
basic head and ground-water flow conditions are
also shown.
A INOUST
Fig. 5. Basic head and ground-water flow conditions.
161
-------
NO 5
n
I 1 U-J
RECHARGE PONDS
~
. / if ^> '
1
1
1
" 1
1
1 °*"
/
LEGEND
O OBSERVATION WELL
• DEEP
O SHALLOW
A INDUSTRIAL SUPPLY WELL
D POTABLE SUPPLY WELLS
/\ PURGE WELL
CHLORIDES IN PPM.
••• 1000 & ABOVE
1.' •• .'.-I 500 - 1000
1 l 100 - 500
1 1 0-100
Fig. 6. Range and concentration of dissolved chlorides.
162
-------
Ground disposal of concentrated industrial
waste waters continued after purging of the con-
taminated ground waters was instituted. The origi-
nal production wells (1,2 and 3) were used in the
initial purging operations. Purging confined and
removed the contaminated waste waters. These
waters were delivered to the suitable receiving body
of water until on-site waste treatment facilities
were built. Figure 6 shows the range and con-
centration of dissolved chlorides, a parameter found
to be proportional to the total concentration of
contaminants. The Figure reflects the areal extent
of the ground-water pollution and illustrates the
combined effects of natural dilution and pumping.
The greatest concentration occurs about the waste
disposal ponds while natural factors disperse the
contaminants away from the ponds. Purge wells 2
and 3 provided an effective barrier between the
contaminated water and the fresh ground waters
tapped by wells 4 and 5.
Figure 7 illustrates the vertical extent of
ground-water pollution and the effect of the cool-
ing water recharge ponds and purge wells. The
flow of waste waters and their vertical distribution
were governed by the natural recharge to the area
and the effect of pumping. The top portion of the
aquifer was the first zone to show improvement
after cessation of disposal of wastes to the ground.
WELL STRUCTURES
The potable supply, industrial supply and
purge wells were all constructed by the cable tool
method of drilling. This method was chosen be-
cause efficient well structures could be accom-
plished with ease and economy. However, the
economies and well efficiencies were balanced with
the immediate needs for production capacity. The
basic physical characteristics of the production
wells are summarized in Figure 8.
Well No. 1 supplied the initial potable and
industrial needs. The well is tubular, 6 inches in
diameter, with 15 feet of screen. The screen was
set in the lower portion of the sand aquifer bottom-
ing at approximately 60 feet. According to records
the well screen is a wire wound, silicon red brass
screen with 0.010 inch slot openings designed for
50% retention of the formation. Based on subse-
quent wells of similar construction, the specific
capacity of the well was estimated to be from 5 to
8 gallons per minute per foot of drawdown.
The construction of the many wells through-
out the site revealed that the aquifer sands are
z
o
1
110 .
100 .
90.
80.
70.
60
50
40.
30
20.
Waste
Ponds
Recharge
Ponds ;
/ < V
/ X
,
PW 4
16-
^
V
\
\
\
I-
LEGEND
WATER LEVEL ELEVATIONS
FLOW LINES
VERTICAL EXAGGERATION = 10
PW = PRODUCTION WELL
P = PUKGE WELL
OB = OBSERVATION WELL
CHLORIDES IN PPM.
1000 & ABOVE
500-1000
100-500
0-100
Fig. 7. Schematic profile.
163
-------
MO I «Q I t
MO14147
Fig. 8. Well constructions.
uniformly fine. This characteristic led to standardi-
zation on gravel pack type well construction. Wells
3 through 7, and replacement wells 2A and 3A are
all gravel packed well structures of the type shown
in Figure 8. The original wells 1 and 2 and the
potable supply wells are tubular wells, also as
shown in Figure 8. The potable wells and industrial
wells 4, 5, 6 and 7 have met and surpassed the
water needs of the company. The original yield
characteristics, as specific capacity, is summarized
in Table 1.
Table 1. Original Specific Capacity
Wells Specific Capacity
(gallons per minute per
foot of drawdown)
Industrial Well No.:
4
5
6
7
I
Potable Wells:
East
West
13.5
14.2
28.1
14.2
6
6
WATER QUALITY
The original water quality of the shallow sand
aquifer was approximately 110 milligrams per liter
(parts per million) of hardness as calcium carbon-
ate, 5 milligrams per liter of chloride, and 0.25
milligrams per liter of iron. These native ground
waters are not as highly mineralized as ground wa-
ters elsewhere in Michigan. Even so, with time
some deterioration in the production characteristics
of the well by chemical precipitation of carbonate
deposits occurs and occasional redevelopment is
required.
The complex chemical nature of the waste
waters originally disposed to the ground has not
only adversely affected the quality of the ground
waters within the area but has created maintenance
problems with the purge wells. It is necessary to
redevelop the wells as often as once a month. The
wastes are more viscous than water, move slowly
through the fine sand aquifer and continually plug
the aquifer, gravel packs, well screen openings,
pumps and pipeline facilities associated with the
purge well system. The chemical characteristics of
the waste waters disposed to the ground over the
years in which this disposal method was used varied
from moment to moment, day to day, and month
month, according to the types of products made
and the market demand.
The industrial waste waters vary in pH from
extremely acid (pH 2±)to highly alkaline (pH 12±).
Some of these waters are organic compounds. BOD
and COD characteristics are also present and ex-
tremely variable.
Part of the fouling of the purge wells appears
to be related to the interaction of alkaline wastes
with the bicarbonate component of the natural
ground waters. Such mixing leads to supersatura-
tion with calcium carbonate. Precipitation of the
latter within the turbulent flow regions of the well
is natural. Organic residues arc another cause of
purge well fouling. Soil bacteria are suspected but
unproven fouling agents.
Despite the complex properties of the waste
waters disposed to the ground over a period of ten
years, persistence and the application of hydrologic
principles has assured recovery of the aquifer.
Figure 9 summarizes this recovery. The contami-
nated ground waters have been steadily removed by
pumping and diluted by natural and artificial re-
charge. Extraction of ground waters at a rate
slightly in excess of the natural recharge confined
the contamination and permitted flushing of the
wastes through the soils and into the purge wells.
As anticipated, the upper portion of the aquifer
was improved first. The improvement of the zone
is shown by well 7a. Natural recharge, coupled with
the effect of pumping, drove the wastes to the low-
er portion of the aquifer as shown by well 19.
WELL REDEVELOPMENT
The fouling of well structures, particularly the
screen openings and the gravel packs, result in
marked reduction in the production capabilities of
the wells. The loss of capacity and need for fre-
quent redevelopment is particularly marked in
connection with purge well systems. In that system,
redevelopment is accomplished by various means
such as air lift surge, pumping surge and jetting,
assisted by the addition of chemicals. Various
chemicals used include acids, alkalines, chlorine and
phosphates. The more tightly plugged the screen
and gravel pack openings, the greater the necessity
164
-------
4MO
mm
O !soo
X
u •
10W
SMj
i r
i i i
i i T
<500
E 35C5
1850
MO
0
IT
I 1 II
I I II
|
T
WELL NO. 7q. J[SHALLOW) WEIL NQ.J9 1PMPJ
CHLORIDES IN SELECTED OBSERVATION WELLS
Fig, 9. Chlorides in selected observation wells.
to use several applications of chemicals and the
most vigorous hydraulic surging procedures.
The purge wells tapping the ground waters of
the highest concentration of pollution, require the
most frequent redevelopment. Even so, gradual loss
of capacity to yields of one-fourth to one-half the
original specific capacity occurs. The less concen-
trated the waste handled by the well, the less
frequent the need for redevelopment and the more
successful the redevelopment. The potable supply
wells and the industrial supply wells 4, 5, 6 and 7,
al! of which produce waters nearly the same as the
natural ground waters, seldom require redevelop-
ment. When redevelopment of these wells is re-
quired, it is rapidly accomplished by acidizing and
surging with the pump, followed with thorough
disinfection bv chlorination.
CONCLUSION
The preceding has summarized the gross
aspects involved in the continued use of a vital
natural ground-water resource while simultaneously
correcting a misuse of that resource. The multi-
plicity of interdisciplinary responsibilities was in-
ferred more than described, but constituted a major
contribution in accomplishing the end result.
The scientific principles, technical methods
and skills associated with the location and develop-
ment of a ground-water supply are equally appli-
cable to the solution of ground-water contamina-
tion problems. However, the role of the geochemist
and the sanitary engineer are more vital in the
solution of ground-water pollution problems if
successful recovery of the damaged portion of the
environment is to be realized. For instance, the
services of the geochemist are needed to assess the
degree of hazard involved and the effect of con-
tamination on the geologic environment. The ser-
vices of the sanitary engineer are necessary for
evaluation of alternate methods of treatment and
the associated economics. Depending upon the
characteristics of the geohydrologic environment
and the nature of the contaminants, the services of
other specialists may be necessary for a proper and
economical solution. It is essential that all parties
involved recognize that if man is capable of utiliz-
ing the many technical aspects of his environment,
he is also capable of meeting the challenge of
correcting the misuse of the environment.
165
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DISCUSSION
The following questions were answered by Edward
M. Burt after delivering his talk entitled "The Use,
Abuse and Recovery of a Glacial Aquifer."
Q. What is the temperature of the water in the
recharge ponds and what effect did these ponds
have on the pumped water temperature from the
two wells immediately east of those ponds?
A. The temperature was checked and the effect
was thoroughly investigated. I am sure all of you
are aware of the problems inherent in the operation
of any type of a facility, whether it's water or
waste water treatment. It seems that we human
beings take the path of least resistance. If a gallon
of water will keep a reactor cooled to the proper
temperature, then the maximum hydraulic flow will
do even better. The average flow of cooling waters
vary from 0.5 to 1.0 mgd. The temperature of 90%
of this flow does not change more than 2 or 3 de-
grees F. By the time the recharge water reaches
Wells 4 and 5 and is blended with fresh ground
water, there is no measurable difference in temper-
ature between those two wells and samples taken
from Wells 6 and 7.
Q. You mentioned that in order to receive a
permit from the Water Resources Commission, the
industry must comply with certain regulations?
What are these?
A. Michigan does not have a rigid set of regula-
tions, but rather establishes specific criteria tailored
to each individual site. These standards are set in
this manner. Any industry that wishes to make use
of either the surface or ground-water resources in
the State must apply for a permit. This application
must indicate the nature of the business and the
waste they wish to discharge. The staff of the Water
Resources Commission confers with other State
igencies, such as the Michigan Department of
Public Health and the Geological Survey, and to-
gether they develop a set of standards based on
existing uses of the particular water resource in
question. The most common limits imposed pertain
to pH, BOD, COD, solids and specific elements.
Q. Since the pollution showed up after a few years
of operation, were the regulations given serious
consideration by the industry prior to the building
of the plant?
A. This question precedes our involvement in the
project, but our experience with the firm indicates
that they have always given serious consideration
to pollution problems, both real and potential.
From what we have ascertained, the problem
evolved because a detailed study of the ground-
water hydrology was not originally required, there-
fore was not originally conducted. Another impor-
tant consideration is the fact that between the time
the plant was built and the time the problem was
discovered, the types of products and processes
employed changed. The regulations under which a
discharge permit is issued are not like the law of
the Medes and Persians—they are just the opposite;
they are in a constant state of continuance. This is
reasonable because, in establishing regulations, it is
not possible to stop time. Each time a manu-
facturer considers the addition of a new product
that introduces a new waste, it is necessary for the
firm to apply for an amended order and the review
process is repeated. This is the manner in which
the presence of a problem was discovered.
Q. What was the character of the material clogging
the purge wells? Was it comprised of corrosion
products, organic growth, etc.?
A. That's the $64,000 one! Let me describe what
happened. When the redevelopment of the wells
was attempted, the greatest problem occurred in
the pump impellers. As in all situations of this
type, the first step was to remove the pump. The
contractor's report indicated that after the bowls
were disassembled, cleaning could be accomplished
most efficiently by allowing the material to dry
and then to remove it with chisels. Soaking in acid
or alkalis was partially effective, but it made quite
a gooey mess. There have not been complete
analyses made of the composition of the material.
The reason a complete analysis has not been made
is that over the years of plant operation, varying
quantities of many different types of waste have
been produced. As a result, during a given time
interval today the waste extracted will reflect those
products of several years ago, but next month the
waste will reflect a different combination of
products and the composition of the extracted
material will be entirely different.
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Bull Session 4—Aquifer Protection and Rehabilitation
Session Chairman: Leslie G. McMillion, Geologist,
National Ground Water Research Program, En-
vironmental Protection Agency, Robert S. Kerr
Research Center, P. O. Box 1198, Ada, Okla-
homa 74820.
Leslie G. McMillion, Lead Bull:
Our session is "Aquifer Protection and Re-
habilitation." All of the speakers of this session are
present; they are Ed Burt, Ken Schmidt, and James
Waltz. Also, Tom Ahrens is sitting in to answer
questions that might be asked on the topic on
which Joe Mogg was to have given a paper this
afternoon; as you are perhaps aware, Mr. Mogg
could not attend the Symposium and consequently
he did not make his presentation.
This afternoon we received more questions
concerning James Waltz's talk than James was able
to answer during the discussion period that fol-
lowed his talk. I have these unanswered questions
with me, and there are about a dozen of them. I
hope we will have time to enter these questions
into the record of this bull session.
I appreciate the excellent attendance tonight.
The subjects are excellent, and I surely anticipate
lots of spirited and interested discussions. We are
ready for your questions and discussion, and we
certainly invite your participation.
Steven IM. Goldstein, Mitre Corporation, McLean,
Virginia:
Mr. Schmidt, we have a great deal of interest
in the technological opportunities that individual
home sewage disposal systems might offer. With
respect to coming up with an optimal national plan
for sewage treatment, there are quite obviously
areas where septic tanks and other individual
systems are very competitive and a better choice
than centralized sewage collection systems. Of
course, quite the opposite holds true in densely
populated localities. It's most important then that
proper septic tank and other individual system
practices be reintroduced as opposed to the current
situation where many builders just dig a hole and
throw them in the ground and the things fail in 5
years, 15 years, or something like that. So, we've
been studying this problem for the Office of Water
Programs of EPA and one of my reasons for coming
to this Symposium is to get a better feeling for how
the people who are actually doing field work in
water resources regard these systems. Could you
comment on what you regard to be some of the
future problems in this area of individual home dis-
posal systems on the basis of the work you've done
in the Fresno area?
Kenneth D. Schmidt, Harshbarger and Associates,
Tucson, Arizona:
Organic nitrogen and ammonia nitrogen,
which occur in both sewage effluent and septic
tank effluent, can potentially form nitrate. In the
case of septic tanks the conditions are generally
more favorable for conversion to the nitrate form.
This is due to the fact that the waste is disposed of
over a large area and anaerobic conditions don't
tend to develop as readily. Under anaerobic condi-
tions, the nitrate may never be formed from the
other nitrogen that forms. Also, denitrification may
be lost as gaseous forms. More control of the nitrate
situation in ground water should be possible with
centralized sewage treatment facilities. However,
each site must be carefully studied. The waste
disposal operation, the soil, and the ground-water
conditions are key factors.
There are areas near Fresno today where plans
exist for new septic tank developments in the foot-
hills. It is obvious from previous studies that the
foothill area has generally poor aquifer character-
istics. The aquifer is thin, the transmissibility is
low, and locally major faults separate the develop-
ments from sources of recharge. Thus, these areas
may be unfavorable for waste disposal of this
type. However, in favorable areas, properly con-
structed septic tanks and disposal systems will be
practical and not harm the ground water. In the
Figarden-Bullard Area, septic tanks have been used
for 20 years. Yet, only 2 wells have ever had nitrate
contents over 25 ppm. Thus, in a favorable environ-
ment, if the wells, septic tanks, and septic tank dis-
posal systems are constructed properly, a nitrate
problem may not occur. Similarly, biological con-
tamination may also not be present.
Hank Baski, Wright Water Engineering, Denver,
Colorado:
We have a pending water quality study of
ground water in an area where nitrates have been
measured up to 50 or 60 ppm. Upstream from the
problem site there's a municipal sewage treatment
plant with secondary treatment, and some people
say that the sewage plant is going to contribute
nitrates which may enter the aquifer. Do the
secondary treatment sewage plants actually take
out nitrate?
Kenneth D. Schmidt:
As far as the amount of nitrogen that enters
and leaves a conventional plant you have to re-
member it's not all in the form of nitrate. We're
usually talking about the sum of organic nitrogen,
ammonia, and nitrate. Most conventional plants
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convert some nitrogen to the nitrate form and also
remove some organic nitrogen. Thus, total nitrogen
is usually significantly lower in the effluent than
influent. I seriously doubt that besides settling out
of solids there is any drastic difference between the
influent and effluent. I think the real opportunity
to control nitrogen occurs after the effluent is
discharged to ponds. Recent studies have shown
that by controlling factors such as pH and tempera-
ture, loss of ammonia from ponds can be enhanced.
Nitrate contents of 50 or 60 ppm would be ex-
pected near sewage treatment plants. Most sewage
effluent contains from 25 to 30 ppm total nitrogen.
If all of this nitrogen was converted to nitrate,
concentrations exceeding 100 ppm could occur in
ground water near sewage plants.
Edward M. Burt, Williams & Works, Grand Rapids,
Michigan:
This nitrogen discussion is interesting. We're
doing many waste water treatment projects in
Michigan that involve oxidation lagoons and spray
irrigation. Concerning oxidation ponds or lagoon
systems, we have built over the years a number of
ponds where the first cell was anaerobic on the
bottom and aerobic on top and then the following
cells were totally aerobic. The initial pond was
designed and built so that the basal portion of the
pond operates under anaerobic digestion and the
surface operates under aerobic digestion which is
typical of oxidation ponds. The balance of the
ponds following this are oxidation ponds of aerobic
digestion. Both types of digestion accomplish
things that are desirable and that's why we have
used them as raw sewage or initial ponds, though
this is no longer allowed by the Michigan Depart-
ment of Health. We designed some of these and got
very high degree treatment. There's a great deal of
discussion and evaluation in Michigan by the Health
Department; and some people, including some
sanitary engineers argue that oxidation lagoon
systems without the anaerobic facility or with it
accomplish what is commonly known as secondary
degree sewage treatment. This process then is
comparable to a mechanical activated sludge plant.
Along the idea of nitrogen removal, this past winter
we obtained permission from the Michigan Depart-
ment of Health to experiment and have winter
drawoffs. The normal procedure in Michigan is that
you store and discharge in the fall and in the spring.
This past winter the Health Department gave us
permission to use continuous discharge from about
9 ponds. And while we had ice cover we drew off
from these at a regular rate while not breaking up
the ice cover, and we had significantly higher
removal of the nitrogen than has been accomplished
by ponds or secondary degree treatment. We don't
have any conclusions but the suspicion is that the
oxidation ponds rely upon algae which feed on the
nutrients in the waste water and in the winter the
algae are not as active as in the growing season;
therefore they die and go to the bottom as sed-
iment with the result that under the ice we pull
off very high quality waste waters.
M. G. Croft, U. S. Geological Survey, Bismarck,
North Dakota:
I'd like to direct this question to Ken Schmidt.
In your discussion this afternoon you mentioned a
background nitrate count of several ppm in the
ground water. I was wondering if you'd care to
comment on the origin of this nitrogen.
Kenneth D. Schmidt:
As you probably know, nitrate has been ana-
lyzed from samples of the Kings River and the San
Joaquin River, and it often ranges from 1 to 3
ppm. Evaporation would slightly increase this
content before percolation of surface waters to the
water table. However, I do not envision the 6 or 7
ppm as all natural, but rather background to the
urban area. Flow net considerations and travel
times in ground water suggest that much of the
urban ground water was actually beneath agri-
cultural lands several decades ago. Thus, some of
the background content could have been supplied
by agriculture. Agricultural lands surround the
urban areas, but were probably not heavily ferti-
lized prior to 1940.
Another natural source besides runoff would
be related to soils near the foothills, northeast of
Fresno. Stout, Burau, and Allardice point out that
areas with a Mediterranean climate are favorable
for natural nitrate accumulation. Strahorn.who did
the early soils work of the Fresno area, noted that
high grasses grew on the alluvial plains. In areas of a
Mediterranean climate, precipitation occurs in the
winter, and natural plants grow and take nitrogen
out of the atmosphere. In the hot summer these
plants die and most of the nitrogen remains as
residue in the soil. This nitrogen is then converted
to nitrate by bacteria. With the coming of the next
winter, abundant rainfall leaches the nitrate past
the root zone and into the ground water.
The Agricultural Research Service has done
studies on a small basis in eastern Fresno County
and has found natural nitrates. Near the east edge
of the San Joaquin Valley rainfall may approach
16 inches per year and vegetation may be more
plentiful. Natural nitrates have been found beneath
dry farmed areas of eastern Fresno County and are
apparently related primarily to the soil. The soils
themselves have some nitrogen even though they
are very low in organic matter. They contain
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something like 1,000 ppm of nitrogen on the
average. However, there is no guarantee that any of
this nitrogen can be converted to nitrate and
leached to the ground water. It is obviously a
source worthy of consideration.
Robert E. Pendergast, Geotechnical Engineering
Corporation, St. Paul, Minnesota:
My question is with regard to installing ob-
servation wells, sampling wells and techniques for
sampling. I'm aware of various methods that can be
used, but I'd like to take advantage of your expert
knowledge on the state of the art. What is the
most efficient method for installing the well and
obtaining the samples for reliability and accuracy
on a normal industrial job, rather than on a long-
term research study?
Edward M. Burt:
Let's talk about observation wells—monitoring
wells in broad generalities. I will make reference to
the industrial investigation that my firm had going
for 15 years, and the work we've been doing to
correct the situation that I discussed in my paper
this afternoon. Since the aquifer of concern in my
paper consisted of unconsolidated sand with rela-
tively good homogeneity throughout the water-
bearing zone, we were able to use the auger ma-
chine for installing 1V4 inch diameter casing in our
observation wells. The auger that we used was a
continuous worm auger that stays open with rota-
tion. We did not find it necessary to use mud to
get good results. On the bottom end of the 1'4 inch
casing we used standard household well points of
24-30 inches long. In some instances we went to 5-
foot well points. I mentioned that we preferred to
sample the upper 15 feet of the formation and the
basal 15 feet; and this sampling approach was a
judgement decision based on the geohydrologic con-
ditions of the site and the soil conditions.
In connection with the construction of waste
water lagoons, oxidation ponds, and spray irriga-
tion, we again tailored the method of investigating
for establishing monitor wells because there has to
be an initial investigation to establish that the soil
conditions and the geologic conditions are proper,
and there has to be a continuing monitoring
program established, especially in connection with
irrigation projects. We normally go in with the
auger machine first. However, we utilize the readily
available well records; for several years the water
well drillers in Michigan have been licensed and
they are required to file logs; and, in addition to
this, the filing of logs on oil and gas wells are
required. We take this information and go on the
site and make preliminary estimates of the direc-
tion of ground-water flow and what the basic
hydrogeologic conditions are. We take an auger
machine and check out our original ideas, and then
we make a predesign of how we are going to ana-
lyze these conditions and how we are going to
finalize the monitoring well system. In more com-
plicated geologic situations we go to either cable
tool drilled wells with casing or rotary drilled
wells with mud and we use electric logs. In using
cable tool drilling, we normally collect our geologic
samples at 5-foot intervals and at each change in
formation. The final well for monitoring is really
designed to the geologic conditions and the use of
the site. We establish the initial ground-\\aujr gradi-
ent and we have to set up sufficient observation
wells to permit continuous monitoring of this by
the people who operate the facility.
George Taylor, U. S. Geological Survey, Washing-
ton, D. C.:
At the present time in West Pakistan, there is
quite a bit of controversy going on over the fall-off
in yields of wells that have been put down during
the last 8 years, using fiber glass slotted pipe. They
have a standard well design. I'm sure Mr. Ahrens is
familiar with this area. I understand he's a well
design expert, going by reputation. He doesn't
know me but I know him. I wonder if he could
comment on the relative importance of the chemi-
cal precipitation of carbonates in the filter pack
around these fiber glass slotted casings as against
the physical clogging of the slots through incom-
plete development.
Thomas P. Ahrens, U. S. Bureau of Reclamation,
Denver, Colorado:
I'm talking pretty much from scuttlebutt. I
have tried to get some definite information and
have talked to several people from Pakistan when
they were in the office over the last few years.
None of them know anything about it. I was fortu-
nate enough to have a few old friends who were
over there working for contractors; and from the
letters I have received from them, I have been read-
ing between the lines. When Harold Smith was
there the first time, they put down all these wells
and tested them, and they turned out to be 2 or 3
second-foot wells, but it was 9 months before they
got the pumps to put in. When they put the pumps
in they turned them on, and they sucked air. They
tried shooting them with primacord, thar would
bring them back for about 2 months and then they
would go out again. So they pulled some of them
and found a combination of sulfate reducing bac-
teria and encrustation; thus, what you had was the
corrosion products mixing with the encrustation
products to give a complete blocking of the well in
a couple of months. So then they started out on
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this fiber glass, reinforced epoxy. The prime con-
tractor on the job called me and wanted to know
what I thought about it, and I said we had been
looking at it for years and were afraid of it. He said
they were going to use it over there and asked me
to recommend a minimum wall thickness. I said I
wouldn't go less than 1A inch. So they went in with
.180 inch for the casing and .200 for the slotted
pipe. Well, from the stories I've received from the
contractors over there, they can't develop those
wells completely. If they go in with air or with a
surge block, they collapse. So what they do is
merely go down to near the top of the screen and
overpump them. They are running anywhere from
60 to 90 feet of perforated casing in those things
and all of you probably know that when you
develop a well by overpumping all you do is
develop possibly the upper quarter or maybe third
of the perforated section. The rest of it—nothing
happens to it. I have always suspected that the
change to the glass reinforced epoxy would cut
down on the corrosion; in fact, it would eliminate
the corrosion. But I always thought that the
encrustation would still occur but that it would be
extended over a long period of time. Now you've
provided the first concrete evidence I've heard that
this is probably happening.
George Taylor:
I think there is still some controversy over this
point; as a matter of fact I'm in the minority. All I
know is also hearsay. I've been in touch with a
number of people, and we have a man still out
there. I think everybody agrees that the fiber glass
is essentially inert. There are no corrosion products
forming directly in the slotted pipe or in chemical
combination with the material. But, these wells
have fallen off in yield. I understand that television
cameras have been lowered down some of these
wells and they have been able to look at the insides
of these wells. They're finding that there is a little
bit of slime on the inside which may be a result of
bacterial action. I have the feeling that a lot of the
precipitation of carbonates may be still occurring
in the filter pack outside the casing contributing to
the fall off in the yields. There is some evidence in
some of the wells that there is quite an accumula-
tion of material in the bottom of the well that has
come through the slots, fine material.
Thomas P. Ahrens:
Just sand? Is it actual material or what?
George Taylor:
Well, apparently, yes, sand has come through.
Through, as you point out, incomplete develop-
ment, you see. So it may be a combination of these
things but most people I've talked to don't give
much credence to this idea that there is actually
carbonate precipitation taking place in the filter
pack. I understand that much of the filter pack
material they use is quite high in carbonate materi-
al, native carbonate material.
Thomas P. Ahrens:
If your screen was not developed for its entire
length, you had your concentrated flow at the top
where it was developed and you probably run into
inflow velocities there, possibly a few feet per
second. So you'd have an ideal situation for the
deposit of carbonates if they were in there. Now
this other slime you mentioned. Do you know if
they are pulling any of those wells down below the
top of the screen?
George Taylor:
I really don't know. I understand they do
have high drawdowns in some of the wells.
Thomas P. Ahrens:
When the water levels are pulled down and
you get Crenothrix, Leptothrix, Gallionella, and all
of those, they'll get down in there and every time
you pull that down a little bit they'll start growing.
And, as they grow down, they block it; the water
table or pumping levels keep going down, so they
just keep moving on down the screen. That might
account for some of that slime you mentioned.
George Taylor:
I understand they only lowered this thing in
one or two wells but they did find some kind of
growth that seemed to be a precipitate or slime
inside the casing.
Thomas P. Ahrens:
Incidentally, do you know if they can pull
that fiber glass pipe or will the joints pull apart
when they try?
George Taylor:
Well, that's another problem. They did, I
understand, get one out more or less intact, but it
was clean. I mean they found no evidence of slime
or precipitates.
Thomas P. Ahrens:
Well, it's so slick that I think if you did have
any carbonate deposits on there, just pulling it out
would probably strip it off.
Jerry Frick, Walkerville Well Drilling Co., Walker-
ville, Michigan:
I'd like to ask Mr. Ahrens if he has any infor-
mation or experience on the relationship between
intake velocity and buildup of encrustation?
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Thomas P. Ahrens:
Let us say "no observation." We have some
beautiful examples at the office that I could show
you of high intake velocities and very high corro-
sion; and also some similar information on encrus-
tation but I have just observed these latter myself.
Now we just use a 10th of a foot per second intake
velocity. We have never had any bad' problems with
that criteria except when we were in a terrifically
corrosive aggressive water; but the problems would
have occurred, I think, whether we would have
been pumping or not.
Edward M. Burt:
I've played with wells too, and so I'll share
some top of the hat recollections. I'm not sure of
the details of the construction of these wells, but I
have been involved in experiences with bacterial
plugging where the best result on redevelopment
was not accomplished by chemical treatment but
by heavy chlorination. Another slimy sort of thing
that we can run into is, for instance, in a double
screened well, with the suction intake set down in
the screen or between the two screens, when you
pull the pumping water level down below the upper
screen you cause a cascading, you have a beautiful
in-the-well iron precipitation plant. And this will
foul them very rapidly, quite completely. As a
practical guide, I haven't used it too much, but by
my experience I'm convinced that you get plugging
beyond the screen face, and perhaps beyond the
gravel pack. A lot has to do with the geology of the
formation. When we talk about gravel packs it's a
misnomer to say gravel because it is really filter
sand in wells that are developed in a silty, fine sand
formation. The City of Kalamazoo recently deter-
mined that the distance out to where the plugging
extended in their wells was between 7 and 9 feet.
These determinations were made by running a step
test in reverse (that is making an injection test) and
calculating the volumes and decrease of injection
rates.
Thomas P. Ahrens:
You mentioned a heavy chlorination. There's
been quite a bit of research done on that and one
item in particular, that being sulfate reducing bac-
teria. It takes at least 400 ppm and about an 8-hour
contact to kill sulfate reducing bacteria. We started
out using the HTH calcium hypochlorite but our
labs called us on it because when you run over 300
ppm on HTH you start precipitating calcium
carbonate. So we have switched over now toClorox
and 2 gallons of Clorox to 100 gallons of water in a
well will give you about 1,000 ppm and we figure
we're getting a certain amount of dilution so it's
probably coming down to around 400 ppm.
George Taylor:
How long would it be do you think before
this bacteria would again build up to the concentra-
tion where they would cause a plugging problem?
Thomas P. Ahrens:
We have a terrific problem with that down in
Wellton Mohawk in Yuma. We started out steriliz-
ing those wells and we found out right after steri-
lization we got a negative reading on our sampling
for anywhere from 2 to 6 weeks, and then it would
start coming back. I think that there are just so
many little crevices and cracks and places for a bug
to hide in a well that you can get 99 percent of
them but that 1 percent that are left are right back
building families as soon as the stuff is gone.
Leslie G. McMillion:
Tom, what is your procedure on taking sam-
ples in checking for bacterial growth?
Thomas P. Ahrens:
That I will have to claim ignorance on, Les.
We turned that over to the microbiologists and
they would go out and pump the well. 1 do know
they had some sort of a filter that they passed the
water through, and collected so much water or
passed so much water through it and then, as I
understood it, the colony actually grew on the
filter. I can get additional information for you if
you'd like it.
Leslie G. McMillion:
Yes, thank you. I will contact you later for
the. information,
Steven N. Goldstein:
Maybe I can clarify that procedure somewhat
for you. I'm no expert in the area but I have gone
through some of those tests. The filter in question
is probably something like a membrane filter with
pore size small enough to trap bacteria. What you
do is take a measured quantity of liquid, say 100
milliliters, draw it through on the vacuum, the bac-
teria then will not pass through, they will be caught
on the filter paper and then you transfer the filter
paper to the top of some kind of a nutrient medi-
um like an agar gel. The nutrients can diffuse up
through the filter and the colonies can begin to
grow. The idea is that each viable bacterium or
other microorganism that can live in that medium
will begin to divide and form colonies and after a
suitable amount of time you can actually see the
colonies as little spots on the filter paper. Now
what you're getting from that kind of a reading is
called a total viable count. In other words, how
many bacteria or other microorganisms did you
have in that initial sample that were viable enough
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to form a colony. But at that particular point you
have almost no idea as to their identity, except for
the fact that you may know something about the
medium which you are using to feed them and you
know that various media are selective for various
species. But you only have a rough idea of what
they might be.
Alfred H. Harder, U.S.G.S., Boise, Idaho:
Are these bacteria indigenous to the aquifer
or are they exotic?
Thomas P. Ahrens:
I was just going to ask Mr. Goldstein if he
could answer a question on that. One of the bac-
teria we're having trouble with is Desulfovibio, a
sulfate reducing organism which, by the way,
causes tremendous problems in pipelines too. But
from what I've been able to read concerning the
pipeline problem, the Desulfovibio generally don't
occur below a depth of 10 to 12 feet. But here
we're getting them down in wells that are 125, 150
and 200 feet. I've had more darned arguments with
various people, and they'll swear up and down they
are in the aquifer. But if you check the size of the
things, they are bigger than any of the pathogenic
bacteria which are filtered out in the aquifer in a
relatively short distance. How could these larger
ones travel through and affect the whole aquifer?
At Wellton Mohawk we have two wells put down
by the same contractor, % mile apart. One of them
has been in for 14 years and has never given any
trouble at all, the other went out in 18 months.
Now if it's in the aquifer, they both should have
gone out.
Steven N. Goldstein:
I can't give you a direct answer but maybe I
can bring to light a few things which might add to a
total picture. First of all, as far as travel of micro-
organisms in aquifers are concerned I have no
first hand experience. I've done some reading on
the subject lately. This was mainly investigations
done on the Santee project in California, and if I
can recall the details correctly there were some
movements on the order of 200 feet, even 400 and
600 feet where the bacteria were picked up in
sampling wells. I believe the situation here was one
of a saturated aquifer—thus, travel through saturat-
ed zones. I'm also led to believe, however, that if
you're not going through a saturated zone that
most of the things are usually filtered out in the
first 7 to 10 feet. As far as the size of the bacteria, 1
don't think that they vary that much in size. I may
be wrong, but I don't think the size variation is
very great. The other thing about bacteria is that
they are all over the place. They're all over your
skin and all throughout your body; and you
couldn't live without some of them. They are on
the floor of the ocean: most of them are concen-
trated in the first millimeter of sediment there.
They are on the floor of the bays, and they are in
the air. Bacteria have even been found in the upper
atmosphere where it was thought there were no
living forms. So you just can't get away from them
and about all you can hope to do is reduce their
concentration in a clean room so that the chances
of one of these things falling and contaminating
some research work you're doing is kind of nil. I
imagine that they'd be fairly ubiquitous in soils
too. It only takes one of these things to get some-
thing going, one or a very few. And you never kill
them all off. The dose of antibiotic that is now
necessary to kill off the gonococcus bacterium that
causes gonorrhea, has gone up quite significantly
because people were getting a dose of antibiotic
that would kill off 90 to 99 percent of the popula-
tion, and those which weren't killed off were the
highly resistant ones. Then, of course, these things
build up in the population and it will take a little
more, and a little more and then a little more anti-
biotic each time, and so this can now become a
significant public health hazard.
Another thing which is very interesting is the
work on clogging that was conducted by Thomas,
Schwartz, and Bendixen at the Robert A. Taft Sani-
tary Engineering Center in the middle 60's. They
were studying the clogging of soil by secondary
sewage effluent with lysimeters. They reported that
most of the soil clogging occurred in the first centi-
meter at the soil-water interface and that severe
clogging was associated with anaerobic conditions
in the zone of clogging. The black color of a slime
which developed at the soil-water interface was due
to the presence of ferrous sulfide but the ferrous
sulfide did not contribute measurably to the clog-
ging mechanism. What happens is that ferric ions
are reduced to ferrous ions by anaerobic bacteria.
In a similar manner, sulfate is reduced to sulfide
and the reduced forms combine to precipitate out
as ferrous sulfide. Addition of acid or restoration of
aerobic conditions rapidly eliminate the ferrous
sulfide but the layer remains clogged to the same
degree. It takes a longer time of drying under
aerobic conditions to destroy the surface mat and
to eliminate much of the clogging agents. In sum-
mary, the clogging mechanism in applying sewage
to the soil through seepage beds, trenches, etc., is
probably due to development of anaerobic condi-
tions right at the soil-water interface. It has been
reported by Mitchell and Nevo that accumulations
of bacterial polyuronides or polysaccharides in the
slime layer may be a major cause of the clogging. I
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really don't have any idea what happens in the deep
wells, but it may be some of these surface phe-
nomena that occur in seepage beds, trenches, etc.
Hank Baski:
I'll comment some more about bacteria. Here
north of Denver we've worked on Fox Hills wells
that range in depth anywhere from 700 to 1200
feet. We chlorinate these wells since chlorination
is required by the Health Department. We try to
have it in the well itself in order to prevent any
bacteria from becoming excessive. It sounds as if
we've got bacteria all over and during normal con-
struction of a well. It would be impossible to pre-
vent bacterial contamination. We found that chlo-
rination in a well seems to keep a well in good
shape. One possible solution in an area which has a
problem is you just chlorinate whenever you pump
so there is a residual chlorine. However, we've got
one water Association which is against well chlo-
rination. It's an odd situation, too, because they
have a well which has a problem; sometimes it will
pump out a slime which may be 5 or 10 percent
of the water volume. I've never looked at the stuff
pumped out, but they say it looks like fish eggs
when coming out of the well. Pipes were coated
with it when they pulled the pump. It seems that
preventative maintenance in the nature of chlorina-
tion of the well would be a possible solution to
these problems.
James P. Waltz:
What is the concentration of chlorine that you
use in this routine treatment of the Deep Fox Hills
wells?
Hank Baski:
It would be in the order of 1 ppm.
James P. Waltz:
What is your procedure for introducing the
chlorine into a well?
Hank Baski:
Whenever the pump operates, it's designed to
operate so the pump starts, the solenoid switch
opens, you've got the pressure differential of the
water pressure at top, just run it through the chlo-
rinator and have a plastic pipe, 1A or % inch which
goes down. We've found it's best to have it go
below the pump because sometimes the stronger
chlorination solution if operators don't watch it
can corrode the pump.
Thomas P. Ahrens:
We had a somewhat similar problem at the
Brush substation at Beaver Creek. What we did
was just take a cylinder of chlorine and about an
eighth-inch diameter pipe and ran the pipe clear
down to the bottom of the well, then we just
cracked that cylinder and we let the chlorine
bubble up. However, it wasn't for potable use, it
was just for cooling water; but it did lick the prob-
lem.
Alfred H. Harder:
I have three things that I'd like to get some
comment on. One is, I had an opportunity to work
on a well from the very first time it was constructed
and the water superintendent of this town was very
concerned about an iron problem in his wells so he
decided that iron bacteria were being introduced.
So from the initiation of drilling of the well he
had everything chlorinated. The workers wore
gloves that they had to dip in chlorinated water,
the drill stem was chlorinated, the mud was chlo-
rinated, and everything was chlorinated. He still
had iron problems in his well. I wondered if any of
you had ever heard of such an approach as this
and how it had come out. The other thing I had an
experience with was on an industrial well in which
the pump failed. They pulled out the pump; it had
a stainless steel pump shaft then, of course, but
around the pump shaft were layers of encrustation.
The peculiar thing was that it was layered-light
layer, dark layer, light layer, dark layer, etc. So I
cut this off and preserved it, and my first reaction
was that it must be 3 years old, and sure enough in
checking with the company the well was 3 years
old. It might be a result of water level fluctuation.
But strictly speaking, water level fluctuation didn't
seem to make a whole lot of sense. So then I
decided, well, it must be they pumped more water
in the summer than they did in the winter and
maybe this caused the encrustation. But I'd like to
know if any of you have heard of a similar occur-
rence, and what would be your interpretation of a
multilayer deposit like this? The stainless steel was
not pitted, it was just as clean and nice as if it had
just arrived from the factory. The third thing I'd
like to mention is that I am really interested in
comments previously made regarding the relative
size of iron bacteria; I believe somebody said that
all bacteria were about the same size while some-
one else said that iron bacteria were larger than
others. I know nothing about bacteria, really. I'd
like a little elaboration on this because what I'm
immediately thinking of is if the bacteria are all the
same size, they must be able to move through the
aquifer. How do they move away from the well?
Thomas P. Ahrens:
Well, I'm not a bacteriologist, I'm just talking
from what I have deducted from my actual field
observations. I think a lot depends on the nature of
the aquifer under study. If you have an aquifer
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consisting of clean well-worked gravel, for instance,
I think bacteria can travel for miles in it. But where
you have a fine sand aquifer, and as Mr. Goldstein
mentioned, you are making tests under unsaturated
conditions, I think they will find that the bacteria
are filtered out rapidly. Now, looking at one of
your other areas of concern—the deposition of
alternating layers of light and dark substances
(perhaps organic substances) in wells—I have never
seen anything quite like that in wells. I have seen
it where you had the filamentous iron bacteria
where it just looked as though somebody had taken
a bunch of horse hair and wrapped it around the
shaft.
Steven N. Goldstein:
Just one comment about the size of bacteria. I
guess a lot of them will range anywhere from a
micron up to 10 microns; there might be some that
are even bigger. Some will travel in groups attached
in a long chain, so that will be even bigger. Some
bacteria have flagella that make them capable of
motion under their own effort. There are all kinds
of different conditions. When you're talking about
something the size of the 1 to 10 micron range and
then you look at the size of the pores in your
aquifer to see what can get through, I think also
x whether it is saturated or not makes a difference.
So when I said they are all about the same size I
mean "sort of in that range."
Thomas P. Ahrens:
Along with what Mr. Goldstein said,.I did
check on sizes of sulfate reducing bacteria. The
average size was about 1.7 microns. Most patho-
genic bacteria are a little less than a micron. That's
what I was referring to when I was talking about
sizes.
Hank Bask i:
Speaking of iron in water, I don't believe
everything is known about it yet, especially with
respect to well water. I've personally had experi-
ence with two cases—one a Fox Hills well near
Denver where the wells when new do not have any
iron in the water and perhaps 1 to 5 years later will
develop iron and get progressively worse. 1 am
inclined to believe from reports of other people
that something in the water is converting the casing
to soluble iron in the water. They ran a pumping
test and there was about 8 ppm iron; then they
heavily chlorinated it, pumped it again, and found
the iron content had dropped to about 2 ppm,
which is quite a drop. The other situation involves
Dakota wells in the Pueblo, Colorado, area; these
wells are all characteristically high in iron content.
Let me make reference to a well in this area
that I field tested last summer; I checked the iron
174
content of the well water as it came out of the well.
The iron concentration of the water varied as we
varied the pumping rate of the well. We discovered
that the water produced at the higher pumping
rates contained lower concentrations of iron than
did water which was obtained from low pumping
rates. Thus, the differences in iron concentration
could be due to the contact time, which the
water has in the well casing. It should be noted that
the water was warm, being almost 100 degrees F,
casing string was 1800 feet long, pump was set at
probably 400 feet; so it had a difference in travel
time and distance sufficient for that water to pick
up iron from the casing. I'm seriously thinking of
trying to case the next well we drill in the Pueblo
area with fiber glass casing, and see what the
difference in iron content is.
Edward M. Burt:
I agree with the statement that not everything
is known about iron. When you start calculating
the pounds per day produced by a well and how
many pounds of iron you've got in the casing,
look out!
Jerry Frick:
I'd like to ask Ed a question since he's familiar
with the sands in Michigan on our side of the State.
We have had in the older, small residential wells the
old, type two metal screens that are supposed to be
subject to encrustation and dielectric action. These
older wells also are of small diameter and have low7
pumping rates. We have put all stainless steel points
in them which would have lower intake velocity,
and we've had a great increase in the amount of
encrustation on several of these wells. I wondered
if you would have any calcium deposits, and
encrustation, just cementing over of the screen.
Some of the older screens have lasted for 10 to 15
years, but these new screens are completely ce-
mented over in 2 years' time. I wonder if you
would know anything about that.
Edward M. Burt:
Are you talking about replacing the screen?
You've pulled the screen?
Jerry Frick:
Yes, we've pulled the old type out-of course
they've been plugged up but they had been in for
10, 15, or 20 years. Then we put in the newer type,
and maybe in 2 years' time they're encrusted.
Edward M. Burt:
When you make this change do you redevelop
the well—acidize it, clean it up?
Jerry Frick:
Not acidizing the well—it's in the small 2-inch
diameter. In the same area, we'll put in 4-inch wells
-------
which would have a lot more intake velocity, and
we don't have trouble; it's just in the small
diameter wells which have slow pumping rates.
Edward M. Burt:
My point was that if you simply pulled the
screen and set a new one in its place and you
haven't redeveloped, you haven't done anything
about the plugging that is occurring in the forma-
tion outside of the screen.
Jerry Frick:
Well, in our area the formation all caves in
when we pull the old screen out. We have to drive
the new one or drill the hole out and install a
new one; sometimes a formation may even have
heaved up the pipe and we have to clean it out and
install a new screen just as if a new well were being
drilled. The only development that the small diam-
eter wells get is only that which is incidental to
their being pumped; and unless we have problems
where there's low capacity, we sometimes surge
them and develop them a little more. But not
normally, no.
Edward M. Burt:
Well, then I'm afraid I can't answer your
question.
Leslie G. McMillion:
We had some questions left over today regard-
ing Jim Waltz's paper which he didn't have time to
answer.
James P. Waltz:
One of the questions was, "could you put on a
slide showing a rock formation and point out dips,
joints, sets, etc. for those nongeologists who are
not familiar with the jargon." Well, obviously over
the microphone I can't put on a slide, but I might
at least define what a joint is. If there are still any
nongeologists, and for the record, the joint is a
crack in the rock, a fracture in the general sense,
along which no movement has occurred. A very
interesting characteristic of joints is that they
often occur in geometric patterns that are fairly
predictable in their orientation. In other words
there is seldom a single crack, there are usually a
number of cracks that are parallel to one another,
all of them oriented in approximately the same
direction. And usually there is more than one set
of these cracks. Secondary and tertiary sets of
joints can usually be found and each of these has a
characteristic direction and dip, at least character-
istic in a statistical sense. Dip is simply the direc-
tion of inclination. The direction of dip defines the
direction of inclination. The magnitude of dip is
the angle from the horizontal, the vertical angle. So
you can have a gentle dip or a steep dip, and the
direction is the direction that water would run off
if you were to pour water on one of these fracture
surfaces. Strike is a term that is commonly found
in the geologic literature. It isn't necessary to use
the term strike. If you define the direction and
magnitude of dip of a fracture you have completely
defined its geometric characteristics.
A second question: "For the first study, was
the degree or amount of pollution in the wells
simply the amount of E. coll bacteria?" For most
of the wells that we sampled in this mountain
pollution study, we considered the well to be
polluted if we were able to get several samples from
the well which showed amounts of more than 1
E. coli per 100 ml sample. The health standards are
consistent with this criteria—that if you find more
than 1 per 100 ml, it's considered contaminated. If
we were able to reproduce this result we considered
the well to be contaminated. I considered the
arrangement as sort of a black and white situation,
either there are E. coli present or there are not, and
it wasn't of much concern to me whether there
were 2, because it's a matter of degree, like preg-
nancy and the common joke.
Russell E. Larson, ARS, USDA, St. Paul, Minnesota:
This afternoon you showed a slide of a cabin
down in this flat, gravel plain, and you indicated
that they had pollution problems. Did you say they
corrected the problem by treating their well water,
or treating the effluent that was getting into the
stream, or did you say that the stuff just goes into
the stream? What are they doing about this?
James P. Waltz:
To my knowledge, they are not really doing
anything about it. Many of them are drinking con-
taminated water. A number of people who recog-
nize the problem have chlorinators on their wells.
Russell E. Larson:
On their wells, yes. But, they don't worry
about what happens to the effluent that is going
out into the stream. Is that it?
James P. Waltz:
That's right. I don't know of any efforts by
these people to treat the water before it leaves their
leach-field system.
George Taylor:
I'm asking a question that should probably be
answered by a sanitary engineer. I'm not a sanitary
engineer; I'm a ground-water geologist. As I under-
stand, they are using, more or less, one standard
type of leaching field, septic tank design for most
of these homesites. Is that correct? Is it pretty
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much a uniform design or is any consideration
given to alternative designs that would be more
effective in this kind of geologic terrain?
James P. Waltz:
Well, again, I'm groping a little bit as far as
what all the alternatives are. I know there are
different designs for leach fields, different types of
distribution systems, drain tiles, and of course dif-
ferent sizes, depending on the amount of effluent
that is anticipated. I firmly believe that there are
perhaps better methods of designing these leach
fields-, primarily what I have in mind is that addi-
tional material could be brought in to serve as a
filtering medium.
George Taylor:
Do you mean sand filters or something of that
kind?
James P. Waltz:
Right—this sort of approach could certainly
improve the situation.
George Taylor:
1 would certainly think so, rather than relying
on the natural material itself.
James P. Walt/:
There is an interesting battle going on in
Colorado right now. There is a fellow who has
developed an individual sewage disposal system that
involves letting the effluent, still kind of ripe, go
out on the surface of the ground, and as a matter of
fact, I think this would be an improvement over
the present situation because the small amount of
soil that is present in the mountainous terrain
would be defective as a filter and if the bacteria
are brought in contact with the soil, with the sur-
face, I think that many more of the bacteria would
be removed than the present situation where they
scrape away all of this good soil, the 6 inches, 8
inches, 1 foot or 2 feet, and then they put their
leach field bed right on the bare rock. So there
certainly are improvements in the design that could
be applied right now.
Paul Goydan. Koppers Co., Inc., Pittsburgh, Penn-
sylvania:
Under present Colorado landfill practice, do
you permit septic tank construction in gravel or
alluvial deposits today?
James P. Waltz:
I assume that the answer is "yes." I am not
directly involved in approval of septic tank loca-
tions. The county sanitarians are usually the agents
who say, "Yes, you can put your septic tank here
or your leach field here." I keep using the term
septic tank when really we're talking about the
176
leaching field that is the critical element. The septic
tank functions fine because, in terms of releasing
effluent, it does it just as well in the mountains as
anywhere else; it's the leaching field end of the
treatment that is failing, in my estimation, in the
mountain. And, it fails where leach field effluent
can pass into clean gravels because the gravels do
not adequately filter and purify the effluent, and I
have seen a number of instances where very clean
gravels have comprised the ''soil" into which these
leach fields have been constructed. I had some
argument at dinner this evening that some of the
mountain streams, which I generalized about, have
perhaps much tighter alluvial materials than I have
admitted; and I think certainly there must be all
kinds of conditions, because if you get very high in
the mountain streams you begin to get into glacial
materials or you have all sorts of permeability
characteristics.
Paul Goydan:
In an alluvial type deposit where you essen-
tially have flat terrain, and your distribution field is
2 to 3 feet below the surface, and in this very
permeable material and no surface cover, you may
expect a fairly aerobic type of condition to exist.
Now would this perhaps enhance the over-all
degradation, the ultimate goal of getting a fairly
safe by-product? I'm curious because under ideal
conditions where we do have the necessary soil
depth and the necessary degree of degradation
occurring we're in fine shape. But what happens in
a very permeable type material?
James P. Waltz:
Let me comment first and I can be followed
by Steve. As long as the effluent is passing through
very permeable materials I question the amount of
filtering and adsorption that can occur. I'm sure it's
a matter of degree and that if you go far enough
through highly permeable material you can achieve
the same effect as passing the fluid through a few
inches or a few feet of appropriate soil material.
But this is really outside my area of expertise.
Steven N. Goldstein:
I'll try and place a little perspective on it.
First of all, when you look at the soil system
itself it's thought that most of the degradation is
being accomplished by microorganisms, and so you
must have the makings of a soil, some kind of an
environment in which these organisms can live in
number and sustain themselves. If you just have
gravel I'm not sure that when effluent is not being
applied the environment would be all that great to
keep them alive. Now remember if you're talking
about just gravel, they're going to swish right
through there. It's not going to be a very long
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percolation. I was reading some minutes of a
Symposium held up at Dartmouth in March of this
year and I believe I'm quoting now from Professor
Ryan Locke from Connecticut University. He
came up with an interesting point, if indeed it's him
that I'm quoting. He indicated that while clays perc
much more poorly, much more slowly, much more
impermeably than sands—and sands just seem to be
great—it's really the clays that are doing—what's the
jargon word—"beneficiation" to the water, actually
purifying it a lot more.
Paul Goydan:
You mean adsorption?
Steven IM. Goldstein:
Well, whatever it is that the soils do, clays are
doing it better than sand; in other words, they're
taking a lot more of the objectionable quantities
out of the water by perking slower, and a lot of
people say they don't want to put a leach field in
clay. But, if you design a leach field of sufficient
size to handle your load, clays apparently are
treating the water a lot better than sands. And it
may be because they give a better climate to the
microorganisms.
Paul Goydan:
This perhaps gets a little bit into the ethics of
the true purpose of the septic tank, or landfill or
anything you are speaking about. Do we really
want to absorb or adsorb, or whatever the term
may be, onto something such as a clay or do we
really want a degradation? I mean, are we just in
fact perhaps storing this? I realize you desire
permeability so that you may hold this particular
material that is giving your substance BOD or COD
so that microorganisms have sufficient time to act
upon it. But this is not the same thing as physical
adsorption and perhaps the distinction here should
be made. The clay will adsorb perhaps, but unless
it has the necessary biological population or organic
matter in the vicinity to function, it will not really
degrade. And perhaps this is really ultimately what
we want. So that's why I asked the question. Per-
haps we can still achieve the desired ultimate goal
of degradation through a little more permeable
type material, something almost like a trickling
filter, although in trickling filters you do have algae
and perhaps insects and this type of thing that helps
the system along. But in a sense, maybe we can
have an underground type of trickling filter and not
adsorption as such.
Russell B. Stein, Ohio Division of Water, Columbus:
I came in here a little late and I wanted to
inquire about the use of septic tanks. In Ohio,
septic tanks in recent years have been under quite
a bit of scrutiny and, as a matter of fact, I think
that in some counties they are actually outlawing
them on new installations. Now, of course, in
established farms and things of this nature, if you
have a septic tank you continue to use it. The
reason for the scrutiny, I suppose, at least in our
part of the country, is that in the glacial till soils
and the high percentage of clay, septic tanks just
simply do not work. We were talking about alterna-
tives for individual waste disposal and I wanted to
ask the question, has anybody discussed in this
section the use of aerobic units, aerobic digesters or
egg beaters, or whatever you want to call them?
This is something which, in a few counties in Ohio,
if you develop a housing development in a subur-
ban area, you either have to go into this type of
disposal or you have to go into a central sewage
treatment plan. Our experience with a tight clay
soil indicates aerobic units are a better means of
sewage disposal for the individual homes. There are
disadvantages, the main one being that people
pull the plug on them and they just discharge raw
sewage. But if there was some regulation on that,
these would do a pretty fair job of aeration and
sewage treatment.
Edward M. Burt:
Earlier we talked about the different types of
sewage treatment and the discussion of septic tanks
is like primary degree treatment which accom-
plished certain functions. You have perhaps heard
of secondary degree treatment which takes this
criteria of primary treatment to a higher degree of
treatment. But I'd like to point out, both to you
and to the other speaker, that when you're talking
about septic tanks, you're really talking about the
mechanisms involved in secondary degree sewage
treatment plants; further, we should realize that
the next step after that is tertiary level treatment
which in the Midwest now consists of phosphate
removal, but pretty soon it's going to include de-
nitrification. Let's all bear in mind that when we
talk about any one of these treatment methods, if
we don't take a look at the total ecological picture
we're just pushing the marble around. We say that
E. coli in certain concentrations are indicative of
pollution so we want to chlorinate and kill them
down to an acceptable level. We do not like high
biological oxidation demands (BOD); so, we satisfy
the oxidation of bacteria to accomplish an accept-
able degree of treatment. But the nutrients are
still there but may be in another form. The reason
Michigan is going to oxidation lagoons, aerobic
ponds, and spray irrigation is to utilize-even use
up—the nutrients, the effluent from a treating proc-
ess, in irrigation of crops. Thus, the cropping is an
important part of the treatment; for instance,
phosphate is one that is readily picked up by many
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of your soil particles, especially your clays, by ad-
sorption. The growing crop can again pick that
phosphate up and utilize it and so you are com-
pleting the cycle of changing it around. In like
manner, the crops use nitrates in their growth cycle.
Russell B. Stein:
I think you misunderstood me or I got off the
track. I was referring primarily to individual home
sewage treatment. Whatever method you choose for
sewage disposal, of course depends on individual
conditions, but I've seen, particularly in Ohio, so
many cases where people have a septic tank system
with as many as four leaching tile fields on a half-
acre lot. Their whole yard is a leaching tile field
yet in the spring of the year they have raw sewage
coming up through their grass.
Edward M. Burt:
They don't have raw sewage, they have
primarily treated sewage, which isn't acceptable.
Russell B. Stein:
I don't know what it is, but it's pretty
raunchy stuff. It's black and evil smelling.
Steven IM. Goldstein:
There are individual system aerobic treatment
units which in many ways are similar to the septic
tank in construction except that air is mechanically
pumped into the tanks, thus attempting to keep the
conditions aerobic rather than anaerobic; a septic
tank is anaerobic digestion, so now you have
aerobic organisms taking over and it's more than
just bacteria. You may have other kinds of bugs
involved there. It's still not entirely clear; however,
a lot of investigations show consistently better
performance for properly operated aerobic units
as opposed to septic tanks. There is only one
hooker. The hooker is you have to keep that pump
working. If the pump doesn't work then the whole
thing goes "kaput." And that turns the individual
homeowner into a waste treatment system oper-
ator; he must check on the pump, he must make
sure everything works properly and this is some-
thing which in general he doesn't want to do nor
does he know how to do it. Secondly, there are
very few qualified people who can maintain the
system even when the homeowner finds out that
something is going amiss. In general, some places
that do require that you have aerobic systems as
opposed to septic systems also require that you
have a maintenance contract with a qualified
maintenance person. So it does show some promise
but there are a lot of problems in terms of proper
maintenance which you never have with a septic
tank.
James P. Waltz:
One quick comment regarding your situation
in Ohio. As I understand the aeration system, you
still have the effluent to get rid of, so you haven't
solved anything other than making the fluid more
acceptable by switching to the package aeration
unit.
Russell B. Stein:
This is true, and then it's simply a matter of
the fluid either going into a leaching field or more
frequently into an open ditch or the nearest water
course. The comment I started to make, and as
this gentleman just emphasized, is the fact that
some people don't want to spend the money for
the power to operate another motor; and, they do
pull the plug on these things. So, if you're dis-
charging into the low part of your land, then you're
strictly discharging raw sewage. If you had some
control that prevented this from being done these
might perform satisfactorily. I'm sure it's a legal
problem, and it's certainly a moral problem. But if
they maintain them, it's my feeling that in certain
geologic conditions it's a much better sewage dis-
posal system because the effluent is of a much
higher quality.
Edward M. Burt:
We seem to be evolving around anaerobic
sewage treatment and aerobic sewage treatment.
Your septic tank is anaerobic and all your anaero-
bic systems characteristically are the odoriferous
ones. The aerobic ones are not so odoriferous. Even
if you had an aerated septic tank system and then
went back into the soil with a leaching tile field,
the nutrients are right there, the anaerobic bacteria
in the soil would take over and you would be right
back to your anaerobic thing that came out of the
septic tank in the first place. It would just change
the type of bugs that thrive on it, back to the
smelly mess.
Roy E. Williams, University of Idaho, Moscow:
Mr. Burt, what happens to a State or federal
agency which issues a permit to dispose, and which
disposal results in a gross pollution problem such as
the one you were discussing today?
Edward M. Burt:
Under the permit system of Michigan, the
Michigan Water Resources Commission has jurisdic-
tion over all of the surface and ground waters of
the State. This agency's permits are not fixed in
time. In other words, each one is a contract with
either a public or private corporation that says
"O.K., you want to do this, these are the limits,
this is the degree of treatment that you have to
178
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accomplish; this surface or ground water is accept-
able for receiving this type of waste." The party
receiving the permit has to monitor the waste dis-
charge and has to submit reports and proofs
monthly that it is living within its stipulated range.
I mentioned this afternoon that there is a "hooker"
clause at the bottom of all these contracts which
states that at such time that a higher degree of
treatment or a nuisance or any other thing is in-
volved that requires re-evaluation and re-establish-
ment, the State agency can order a change.
Roy E. Williams:
In other words, nothing happens to the State
agency if pollution results? Is that correct?
Edward M. Burt:
Yes, the responsibility rests on the user of
the resource.
Paul Goydan:
Mr. Burt, if you only have the funds to
construct a few monitoring wells, where would
you put them, and to what depth below the water
table to learn the vertical extent of contamination?
Edward M. Burt:
We design the monitoring wells after we have
drilled exploration wells to evaluate the geologic
and hydrologic conditions, and to establish the
observation well pattern. To illustrate this with the
example which I discussed this afternoon, we first
found out the basic conditions, the direction of
flow, area of contamination; and we worked from
the surface of the water table on down. In other
words, we sampled as we went down. From this
we came up with a final design of the monitoring
system with shallow wells that were in the upper 15
feet of the water table, and others within the bot-
tom 15 feet. (This was a water table aquifer,
incidentally.) But, the business of limited funds
goes back to the responsibility of having sufficient
proofs that you are complying, or you have suffi-
cient data and it doesn't stick. It's the responsibility
of the party that's going to use this resource to
protect it. And if he does cause contamination or
pollution, that is unacceptable and he has to cor-
rect it. As far as the regulatory agency is concerned,
they don't care what it costs.
Russell B. Stein:
Mr. Schmidt, we had a relatively small nitrate
contamination problem in a rural area of Ohio
which I worked on a number of years ago. It only
involved about 4 or 5 square miles and possibly 25
or 30 individual farms, but we had some pretty
high nitrate values. We had a situation similar to
what you described in Fresno where there were
several potential sources of nitrate in the water. For
example, there were agricultural fertilizer, septic
tanks and feedlot operations. In our chemical
analyses we tried to make a distinction between
some of these sources by analyzing for chloride
and also potassium. We had pretty good base data
in this area and we knew what was normal for
most of these values; and, in some instances where
we had rather high nitrates, we would get high
potassium values and low chlorides. In these cases
we suspected chemical fertilizers. In other instances
we had very low potassium (maybe zero potassium),
high nitrate, and high chloride and this led us
toward sewage sources. Did you do any analysis
with potassium and do you think this is a valid
tool to use in this kind of study?
Kenneth D. Schmidt:
In my study area there is one outstanding
source of potassium, namely winery waste water.
One of the by-products of the winery operation is
potassium bitartrate. So, using potassium would be
logical near wineries. The problem with potassium
is that it is not very mobile in these alluvial ground-
water systems. Potassium is also high in sewage
effluent as compared to most ground water. If one
wants to distinguish between agricultural fertilizers
and other sources, chloride is a very good constitu-
ent to consider. There are difficulties in using
potassium in agricultural areas such as in Fresno
County. Little potassium fertilizer is used as com-
pared to anhydrous ammonia. Anhydrous ammonia
when applied to the soil is known to have a great
replacing power. Thus, cations such as calcium,
sodium, and potassium may be replaced by am-
monium ions from the fertilizer. However, in areas
other than alluvial basins, potassium may be a
useful cation. People should be encouraged to use
all available chemical data, not only chloride and
potassium, but boron, fluoride, and other constitu-
ents.
Russell B. Stein:
I probably should have clarified this a little
better. This was an area in northwest Ohio which
was in a very shallow carbonate area; the highly
cavernous limestone aquifer was exposed at the
surface in the area; it was likewise an area of
extremely poor well construction. Most of the wells
were between 50 and 75 feet deep but were only
cased to depths of 10 feet or less and for this reason
we felt we were getting extremely rapid drainage
from the surface directly into some of these wells.
We corrected most of the nitrate-contaminated
wells by deepening them and double casing them,
to 100 feet or so, and it did solve the problem.
Now, concerning the potassium, we have observed
179
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that if ground water in Ohio has more than 1 ppm
or maybe 2 ppm something unusual is happening;
thus, we were alarmed because we were getting 20
to 30 ppm in some of these wells. Something
caused this and in this instance it wasn't due to
wineries.
Paul Goydan:
From hearing the talks and discussions the
last 2 days, it seems to me that we're largely talking
about the soil as a means of disposal, not only in
landfills or in septic tanks; but irrigation has also
been mentioned. I would like to emphasize this.
Much of the research today has been directed
towards surface-type treatments, and we have
really neglected this natural resource we have in the
soil and its ability to do an effective job. One of the
things that should come out of this conference is to
direct research and funds to this area. I believe this
has a lot of promise. We're not only talking about
contamination, we're talking about disposal, degra-
dation, and available means for solving our prob-
lems. Let's look more closely at the soil, and one
area I'm particularly interested in is soil irrigation.
We haven't had too much discussion there but this
is an area I'd like to see the various control
officials, industry, and organizations get involved
in. Perhaps we shouldn't be so ignorant when it
comes to subsurface means to dispose of our waste.
Let's get down to the nitty gritty, face the facts,
and really try to solve the problems; and hopefully
this will be something that will come out of the
conference.
Edward M. Butt:
I agree with you. I'd like to point out a couple
of studies that are going on. One that has many
years of background research is at Penn State Uni-
versity. We are participating in an EPA financed
study. The City of Belding, Michigan, with a popu-
lation of around 5,000 has a series of waste water
lagoons. A portion of this effluent is being used in
two irrigation areas, summer irrigation and winter
irrigation. This is all layed out for 2, 3, and 4
inches of application, the type of soils, and it's a
complete type of study where you analyze the soil,
how much penetration, and effect on various crops.
In addition to these 2, something about the sewage
treatment operation known as the Muskegon Coun-
ty project—this is also in Michigan. There again they
are talking about oxidation ponds, lagoons and
irrigation, and some questions were raised today
about this. There was comment that under the
irrigation area they were speaking of underdraining
it with tiles; I do not know the details but my
understanding is that while this is another sandy
lake plain with unconsolidated sands, it will run
180
down to maybe 50 or 75 feet and their intention is
to ring the irrigation fields with dewatering wells
and pump (in the terminology of Penn State) the
renovated waters captured by these wells that are
intended to collect anything that seeps through and
isn't used up in the soil or taken off by the vegeta-
tion, and discharging that to a surface water body.
Paul Goydan:
We do need to look at the specific variables
involved. It is fairly well established that it is feasi-
ble and practical in many instances to treat waste
fluids, particularly municipal sewage, by spray
irrigation and production of vegetative crops with
it. The Penn State studies in particular showed
these systems to be feasible. But, these studies fail
to get down to what the real mechanisms involved
are, and to show how the data can be extended to
and used in other areas. They showed some of the
characteristics of their system and they showed
that the system can work, and they were working
with a domestic waste at that. But, when you start
talking about industrial waste and various special-
ized types of chemistry, here again is another story.
I think we are moving in this direction and I'll be
looking forward to getting the data and the results.
Leslie G. McMillion:
Along this line of using the soil as a living
filter and treating media for sewage and waste
waters, I have recently become convinced that such
waste treatment methods could have a place in the
over-all plan for sewage treatment and disposal in
such heavily populated areas as Long Island, New
York. If you're familiar with the ground-water
situation on Long Island you realize that past and
present methods of handling the Island's municipal
and domestic sewage have resulted in some publi-
cized cases of ground-water contamination. These
cases involve local buildup of relatively high con-
centrations of nitrates and other substances such
as chlorides. The apparent cause of the local prob-
lems is downward seepage of contaminating fluids
from septic tanks, sewage lagoons, and the like.
There are literally thousands of individual domestic
sewage disposal systems on the Island since most of
it is not served by public sewer lines.
The soil treatment method could be especially
useful on Long Island since a principal nutrient
source which can be removed by this process is
nitrates; and, as you probably know, contamina-
tion by high levels of nitrates is one of the primary
concerns of the Long Island situation. However, we
cannot disregard the difficulties that could be
involved in instituting the actual treatment opera-
tions in such areas as this one; the main problem
could be the availability and price of land for the
-------
operation. Another difficulty could be technical
know-how itself; and in this regard, we are thinking
of the actual design and operation of a unit.
While these concepts of soil treatment of
wastes are in their infancy, it is interesting to note
that they are not being totally ignored in the
country. A considerable amount of money has
been released to the U.S. Army Corps of Engineers
so that the agency can make studies of waste water
collection, treatment, and disposal in 5 of our large
metropolitan areas: San Francisco, Chicago, De-
troit, Cleveland-Akron, and Boston. It is my under-
standing that what prompted the initiation of these
studies was concern over the possibilities for using
the so-called "land treatment" methods (such as
spray irrigation of waste water) as a way of treating
municipal sewage. While many are skeptical about
these methods providing all the answers, we do see
a place for them in the total waste treatment and
disposal picture. It may be inconceivable that all
the waste fluids from these 5 metropolitan areas
could be treated by the land treatment approach;
but it is reasonable to assume that some of it could
be treated in that fashion. So, there may be possi-
bilities for broad applications of this concept. If
possibilities exist for its application in the northern
areas of the nation, the opportunities for success of
the method should be much greater in the southern
and southwestern States where the growing season
is longer.
Edward M. Burt:
In the conversations we've had in the last 2
days, while the emphasis is on utilizing the soil for
waste treatment and what happens from the land-
fill and from the sanitary waste water aspects, and
industrial aspects, another thing that has been
paramount is the general realization that it takes
the combination of many types of skills to accom-
plish a workable solution to these problems. It isn't
just the geologist or the hydrogeologist or the sani-
tary engineer. When you start working with the soil
you should be looking for the agricultural specialist
because the type of crop that you utilize in an
irrigation system can make a great deal of differ-
ence. For instance, the crops that we're most fre-
quently talking about in Michigan are corn, because
it has a very good extractive characteristic; Reed
canarygrass; and brome-alfalfa mix. Now some
types of alfalfa instead of taking nitrogen out of
the soil, take it out of the air and put it in the soil.
We're looking for those things that take the nutri-
ents back out because to a degree the soil is a
storage reservoir for those things that you want
captured by adsorption and then taken back out.
Clay minerals have generally very good capability
for removing phosphates, but you want to get it
back out of there; otherwise you're storing it.
This brings up another thought—I mentioned
today that this industrial company in the final
treatment methods that were used, the highly
concentrated combustible waste which was in the
order of IVa to 2% went to incineration, and the
question was asked, "What happens to the waste
from the incineration?" This is collected and goes
along with the other 2%% of the wastes that require
additional treatment, into a concrete stabilization
lagoon or pond with aeration, for removal of
ammonia (for instance), and where we are trying
to develop a growth of bacteria to prove the feasi-
bility of going into a standard secondary degree
treatment process. I mentioned that the cost of
incineration was about the same as the cost of dis-
posing of the same volume via a deep disposal well;
thus, some of you are perhaps wondering why we
didn't go to deep subsurface disposal. I mentioned
we'd been considering casing to a depth of about
3,000 feet and disposing into formations between
3,000 and 5,000 feet. I, as a geologist, worked on
the design and the method of deep well disposal
and one of our sanitary engineers, along with some
combustion engineers, studied the economics of
the incineration; then we sat down and argued the
pros and cons of each method. In those discussions,
I expressed a personal philosophy that I still adhere
to—that the more things we can handle on the sur-
face of the earth where we can readily get at the
mechanical workings to make proper repairs, the
better off we are in the long run.
Leslie G. McMillion:
I have been notified that all three of the other
sessions have adjourned. In light of that and since it
is past ten o'clock, we will very shortly conclude
this session.
It is most difficult for me, as session chairman,
to appropriately express my appreciation for such
tremendous participation as we have had here
tonight. I thought that our panel really outdid
themselves in answering the questions from the
floor and providing other comments for the record
and for our edification; I thank each one of you for
your excellent contribution. This session would not
have been possible without the presence and active
participation of you who have attended tonight.
We thank you for your attendance and your
enthusiastic participation. We were very glad that
several of you helped answer some of the questions
that were asked, and provided information on some
knotty technical topics.
This session has been especially interesting and
stimulating. I am sure that we all hope that the
enthusiasm of this meeting will carry far beyond
Denver and this point in time.
181
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A Systems Approach to Management of the
Hanford Ground-Water Basin"
by D. B. Cearlockb
ABSTRACT
Mathematical models for simulating ground water and
radionuclide movement as a function of time and space are
being developed. In addition to the models, a man-machine
interactive computer system is under development for use
in model applications. In total, the research and develop-
ment program will produce a management and engineering
too! for use in analysis, decisions and policy formulations
relative to management of ground-water systems.
The system is separated into sequential or parallel
components that can be modeled independently of each
other. This results in maximum capability to simulate all
combinations of situations that may be encountered and in
ease of modifying or refining the models independently
without having to reformulate the entire system. The
system is composed of three major categories of models:
(1) data models; (2) hydraulic models; and (3) water
^quality (transport) models. Data models calculate input
characteristics required for operation of the hydraulic and
water quality models from a minimum of field measure-
ments. The Transmissivity Iterative Routine for calculating
transmissivity distributions and the Sorption Transmissivity
Routine for calculating sorption coefficient distributions
are two types of data models. The hydraulic models
predict the flow of ground water in saturated and un-
saturated soils. The Partially-Saturated Transient Model,
which describes unsaturated, transient flow, and the Vari-
able Thickness Transient Model, which describes saturated,
transient flow, are included in this category. The water
quality models predict the movement of the waste through
the subsurface soils. The Macro-ion Transport Model, which
describes macro-ion movement, and the Micro-ion Transport
Model, which describes micro-ion movement, are included
in this category. The assumptions used in developing the
system of models, justification of these assumptions, the
interrelationship of each of the models, and the intended
application of the entire system are presented.
The man-machine interactive computer system pro-
vides an efficient means for the engineer to interact in the
problem solving functions using the previously discussed
models. The system allows the engineer to rapidly scan a
Presented at the National Ground Water Quality
Symposium, Denver, Colorado, August 25-27, 1971. This
paper is based on work performed under United States
Atomic Energy Commission Contract AT(45-1)-1830.
"Manager, Water Resources Systems Section, Water
and Land Resources Department, Battelle Pacific Northwest
Laboratories, P. O. Box 999, Richland, Washington 99352.
182
large number of alternatives and use his experience in
rapidly converging on a solution. The components of the
computer system and their functions are described. Exam-
ples showing how the computer system is being used with
models that have been developed are presented.
INTRODUCTION
Since the beginning of the Atomic Energy-
Commission Hanford Project in the mid 1940's,
geological and hydrological investigations have been
conducted to establish and evaluate management
alternatives with respect to storage and disposal of
waste materials in the vadose zone above the re-
gional water table. Initially these investigations
consisted mainly of analyzing (1) well logs and
driller's samples for stratigraphic information and,
(2) ground-water potentials for ground-water move-
ment patterns and rates. The efforts concentrated
on defining and understanding the water-table
aquifer because of its direct relationship to waste
management activities. Historically, Hanford waste
management practices have been based on conserv-
ative assumptions and an extensive monitoring
program to evaluate and measure the effects of
these practices.
Investigations have continued in an effort to
improve the understanding of the water-table aqui-
fer. The aquifer has been classified into textural
types and pump tests have been conducted to de-
termine the permeabilities of each textural type.
This data showed that the Hanford ground-water
system was highly variable.
In an attempt to develop a practical tool
for managing the ground-water basin, simu-
lation techniques were employed. Initially, simple
graphical flow net analysis and analog models were
tried. With the increase of capability and flexibility
of the digital computer, the emphasis shifted to
mathematical simulations. The modeling effort was
directed toward simulating steady, ground-water
flow. These models were theoretically sound, but
the output was less reliable than desired because
the data input requirements could not be economi-
cally satisfied. It was, therefore, necessary to make
-------
compromising assumptions in order to use the
models. In addition, the models could not simulate
transient conditions or waste transport, which are
required to answer many of the pertinent problems
associated with management of a ground-water
basin.
Recent pressures for multiple uses have posed
important questions concerning the management of
the Hanford ground-water basin. Although signifi-
cant time and effort have been expended on
collecting field data and conducting field investiga-
tions, methods have not been available to utilize
these data to produce the answers required for
waste management decisions.
To provide the methods for answering ques-
tions concerning management of complex ground-
water basins, a major program was undertaken to
develop a system of mathematical models for
simulating ground water and waste movement as a
function of time and space. Selection and develop-
ment of the system of models was based on the
economics of data input requirements, precision of
results required, and the practicality of application.
In addition to the models, a man-machine interac-
tive computer system is being developed to provide
an efficient means for utilizing the models and ana-
lyzing the results. In summary, the program is pro-
ducing a management and engineering tool for use
in analysis, decisions and policy formulations rela-
tive to management of ground-water systems. A brief
description of the models, assumptions and justi-
fications of the assumptions, the interrelationship
of each of the models and the intended application
of the entire system are presented. Also included is
a description of the interactive computer display
system.
DESCRIPTION OF SYSTEM COMPONENTS
The objective of this program is to develop a
ground-water resources management tool which can
be applied practically to both local and regional
ground-water systems and which will provide reli-
able answers to those pressing problems associated
with the exploitation of ground-water systems. To
accomplish this objective, the ground-water system
was separated into sequential and/or parallel com-
ponents that could be modeled independently of
each other: saturated flow, unsaturated flow, and
contaminant transport. This resulted in: (1) maxi-
mum capability to simulate all combinations of
situations that could possibly be encountered, (2)
generally applicable models that could be applied
to any ground-water system in which the basic
assumptions were satisfied or where the assump-
tions were not compromising, and (3) ease of modi-
fying or refining the models independently without
having to reformulate the entire system.
The model development effort is presently
separated into three major categories of models:
data models, hydraulic models, and water quality
(transport) models. Data models calculate, from a
minimum number of field measurements, input
characteristics required for operation of the hy-
draulic and water quality models. The hydraulic
models predict the ground-water velocities or rate
of ground-water movement in the unsaturated and
saturated sediments. The water quality model com-
bines the ground-water movement calculated by
the hydraulic models with soil-waste reactions that
contaminants would undergo during a traverse
through the soil to predict the contaminant move-
ment. In effect, the ground water is a transporting
mechanism and can be simulated independently of
waste movement. A simplified schematic showing
the interrelationships between the data, hydraulic
and transport models is shown in Figure 1. Table 1
lists the models and their respective functions as
well as input data requirements and output in-
formation. Each of these categories will be dis-
cussed in the following narrative.
Fig. 1. Schematic diagram showing interrelationships and
data flow between the various categories of ground-water
models.
Data Models
Data models include those developed to calcu-
late (from a minimum number of field measure-
ments) input characteristics required for the
operation of the hydraulic and water quality
models. In the initial planning stages of the
program, it was realized that it was not economical
to obtain input characteristic data using the
classical method of extensive field data collection
programs. Therefore, models were developed which
would use data that were available or could be
obtained economically, and from these, calculate
the desired model input. The most important
model that comes under this category is the Trans-
missivity Iterative Routine.
It is common in ground-water systems for
permeabilities to vary considerably over study
areas; thus, the assumption of a homogeneous
permeability distribution will usually result in
erroneous predictions in changes in ground-water
elevations and flow patterns. Because of these
variations in permeabilities, the cost of establishing
183
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Table 1. List of Ground-Water Models, Functions, Input Data Requirements and Outputs
Models
Function
Input
Output
Data Models:
Transmissivity Iterative
Routine
Hydraulic Characteristics
Routine
Sorption Transmissivity
Routine
Micro Sorption Routine
Hydraulic Models:
Partially-Saturated
Transient (PST) Flow
Model
Variable Thickness
Transient (VTT) Flow
Model
Transport Models:
Macro-ion Transport
Model
Micro-ion Transport Model
Calculation of model input
from minimum number of
field measurements.
Calculates transmissivity dis-
tributions.
Calculates permeability func-
tion (permeability vs. capillary
pressure relationship).
Calculates s o r p t i o n coeffi-
cient distribution.
Determines the coefficients
for the Kd-macro-ion relation-
ship.
Simulation of subsurface wa-
ter movement.
Simulation of unsaturated
flow.
Simulation of saturated flow
(approximates three - dimen-
sional systems).
Simulation of subsurface
waste movement.
Simulates macro-ion m o v e -
ment in saturated and unsatu-
rated soils.
Simulation of micro-ion
(trace) movement in saturated
and unsaturated soils.
1. Ground - water potentials;
2. Transmissivity measure-
ments.
1. Desorption curve (moisture
content vs. capillary pressure);
2. Saturated permeability.
1. Sorption-transmissivity re-
lationship;
2. Transmissivity distribution.
1. Experimental data for spe-
cific soils and wastes.
1. Hydraulic characteristics;
2. Boundary conditions;
3. Initial conditions.
1. Transmissivity distribution;
2. Initial conditions;
3. Boundary conditions: in-
cludes quantities and location
of recharge calculated by the
PST Model.
1. Cation exchange capacities;
2. Initial concentrations on
the soils;
3. Grou nd-water velocities
from either PST or VTT
models;
4. Boundary conditions.
1. Sorption coefficient distri-
bution;*
2. Initial concentrations on
the soils;
3. Macro - ion concentrations
as a function of time and
space from the macro - ion
model;
4. G round-water velocities
from either PST or VTT
models;
5. Boundary conditions.
Heterogeneous transmissivity.
Permeability function.
Sorption coefficient distribu-
tion.
Coefficients for the Kd-macro-
ion relationship.
Time-dependent ground wa-
ter: (1) potentials; (2) veloci-
ties; (3) flow rates; (4) flow
paths; and (5) travel times.
Time-dependent ground wa-
ter: (1) potentials; (2) veloci-
ties; (3) flow paths; (4) flow
rates; and (5) travel times.
Macro-ion concentrations in
liquid and solid phases as a
function of time and space.
Micro-ion concentrations in
liquid and solid phases as a
function of time and space.
* Input requirements vary depending on the situation being modeled; i.e., either unsaturated or saturated and the importance
of the macro-ion influence on micro-ion movement, etc.
184
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an observation well network and making the many
measurements required to assure a reliability per-
meability distribution quickly becomes prohibitive.
To avoid the prohibitive cost of a massive number
of field measurements, a computer routine was
developed which allows calculation of the perme-
ability distribution over study areas using a mini-
mum number of field observations. The method
developed, based on continuity of flow in a stream-
tube for a quasi-steady state ground-water system,
utilizes the measured energy dissipation in a stream-
tube to calculate transmissivity and/or permeability
at any point within the tube.
The program was written for two-dimensional
systems where the transmissivity is assumed equal
to the product of the depth and the average perme-
ability over the vertical section of the aquifer.
Although the method could be extended to include
the third dimension, the field data available or that
which could be obtained economically does not
warrant such an extension at this time. Figure 2
shows the calculated transmissivity distribution for
the Hanford Reservation ground-water system.
HANFORD PROJECT
Fig. 2. Calculated transmissibility distribution of the Han-
ford ground-water flow system.
Using this transmissivity distribution along
with the ground-water potentials, the existing travel
times and flow rates from any site on the Hanford
Reservation can be calculated. Figure 3 shows the
relative travel time from a reference line located on
a 50 square mile block of the Hanford ground-
water system. The predicted three-pronged effect,
a result of high permeability channels, agrees very
well with measured observations of ground-water
contamination in that area. The effects of hetero-
geneity on waste movement are explicitly shown
by this three-pronged front. It would be impossible
to simulate waste movement accurately in the
Hanford system by assuming a homogeneous trans-
missivity distribution and using a large dispersion
factor to mask the effects of heterogeneity. This is
why it is necessary to have an accurate trans-
missivity distribution and why considerable effort
has been expended in developing methods with
which these data can be obtained economically.
The photograph in Figure 3 was taken off a com-
puter generated Cathode Ray Tube (CRT) display.
Fig. 3. Ground-water movement pattern at time = t, origi-
nating from a reference line on a portion of the Hanford
ground-water system.
This program is presently being extended to
include transient systems. In addition, it has been
adapted to a man-machine interactive computer
system (which is discussed later) so that the errors
in interpreting ground-water potentials can be
minimized. This involves an iterative process of
reinterpreting ground-water contours from the
original data and recalculating the transmissivity
distribution. The process would be impractical
using standard computer input/output procedures.
The method is called the Transmissivity Iterative
Routine.
In modeling unsaturated flow, it is necessary
to have a mathematical description of the hydraulic
characteristics of unsaturated soils. The hydraulic
characteristics consist of two relationships: (1)
185
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permeability versus capillary pressure (permeability
function); and (2) moisture content versus capillary
pressure (desorption curve). Obtaining the permea-
bility function from laboratory measurements is
extremely time consuming and expensive relative
to the number of measurements required to
accurately define a system. Methods developed for
calculating the permeability function from the
desorption curve and the saturated permeability
have been modified and used successfully. Since
the desorption curve and saturated permeability
data can be obtained without too much difficulty,
this approach to establishing hydraulic character-
istics of unsaturated soils represents a considerable
savings in time and money.
The micro-ion (radionuclide) sorption coeffi-
cient is a function of both the soil type and the
macro-ion concentrations. The Micro Sorption
Routine determines the coefficient for the relation-
ship between the Kd and macro-ion concentrations
using a two factorial design regression technique.
Experimental data must be collected for each
soil type and range of wastes encountered.
On large systems, such as Hanford which
covers in excess of 400 square miles, it is im-
practical to mount the field data collection pro-
gram necessary to accurately define the spatial
N sorption coefficient (Kd) distribution. Therefore, a
data model is being developed to calculate the Kd
distribution for large ground-water systems utilizing
a minimum number of field measurements. The
approach being used is to relate the Kd to the soil
type through the permeability/transmissivity distri-
bution. Since an accurate transmissivity distribu-
tion can be obtained using the Transmissivity
Iterative Routine, a Kd distribution can then be
calculated from these data. Preliminary results are
very encouraging. To use the method, available soil
samples are analyzed to obtain the permeability
versus Kd relationship. Once this relationship is
established, the Kd distribution can then be calcu-
lated from the transmissivity distribution.
Hydraulic Models
It was decided at the initiation of this program
that the most practical approach to modeling
ground-water flow was to consider the unsaturated
and saturated ground-water flow system separately
rather than as a combined system. This decision
was made in consideration of the field data availa-
ble and the cost of obtaining additional data, the
size of core memory in large computers presently
available, and the computational time associated
with use of large grid networks to obtain numerical
solutions. Considering the systems separately re-
sults in having to define the hydraulic character-
istics only at sites where unsaturated flow is im-
portant (points of recharge or injection). This
limits the amount of data required on unsaturated
soils and for most problems is not compromising.
It is anticipated that the unsaturated model will be
used to calculate the quantity of flow entering the
ground-water system. The calculated inflow is then
input to the saturated model to predict the changes
in the ground-water surface elevations.
The capillary conductivity approach was cho-
sen for modeling the unsaturated portion of the
ground-water system. The model is based on con-
tinuity of flow into and out of an elemental volume
where the permeability, hydraulic potential and
moisture content are all a function of capillary
pressure. The model is valid for transient, heterog-
eneous, saturated and unsaturated flow. The pri-
mary input requirements to this model are the
hydraulic characteristics, permeability - capillary
pressure, and moisture content-capillary pressure
relationships.
The PST computer program will pres-
ently work in one and two dimensions, and
in three dimensions for axisymmetrical
problems. The program can be extended to
include the third dimension. It should be noted
that while the PST Model is used to describe
combined saturated and unsaturated transient flow
above regional water tables, it also can be used to
solve combined saturated and unsaturated flow
problems which include the regional ground-water
system. The reason the PST Model is not used in
this manner is that a model which approximates
three-dimensional saturated flow (VTT Model), has
also been developed. As mentioned earlier, using
the two models significantly reduces the amount of
input data and computer core memory required, as
opposed to the entire system being modeled with
the PST Model.
The PST Model has been used to simulate
hypothetical buried tank and pipeline ruptures.
Figure 4 shows output from two hypothetical
problems that were analyzed with the PST Model.
Figure 4(a) shows the moisture pattern developed
at 223 minutes after a simulated pipeline rupture.
The degree of saturation in these Figures is propor-
tional to the intensity of light on the computer
driven CRT from which these photos were taken.
Therefore, white indicates saturation while black
indicates the initial soil moisture. The various
shades of gray indicate gradation of moisture
between these two limits.
Figure 4(b) shows the moisture pattern de-
veloped at 16.55 hours after a simulated storage
tank rupture. There are five geologically distinct
strata which are represented by the four horizontal,
186
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Fig. 4(a). Moisture distribution for a 3 inch pipeline break
simulation (time is indicated from start of problem, and
seal is in feet).
Fig. 4(b). Moisture distribution resulting from a simulated
storage tank rupture.
Fig. 4. Computer generated displays showing output from
the PST Model for two hypothetical problems that were
analyzed.
white lines. The total distance between the tank
bottom and the water-table surface is approx-
imately 230 feet. Results from this model are
encouraging since very little has been published
relative to the numerical solution of the equa-
tion involved. The numerical problems encountered
on the tank and pipeline break simulations were
severe because of the low initial saturation (approx^
imately 8% moisture content), the high positive
heads and the large variations in permeabilities.
Studies of this nature are continuing in both
field applications and for model verification. Model
verification includes simulation of both one and
two-dimensional columns under precise laboratory
control utilizing nondestructive testing procedures.
As a result of the testing to date, it appears that the
model can be used to simulate any situation that
will be encountered on the Hanford Reservation.
The above simulations demonstrate the utility of
the models in developing management policies and
evaluating management alternatives.
For the saturated portion of the flow system,
a two-dimensional model that approximates three-
dimensional saturated, transient flow was devel-
oped. The model (VTT) was developed for a
heterogeneous system where the permeability,
aquifer bottom elevation, and storage coefficients
are a function of space coordinates, x and y.
Changes in transmissivities resulting from changes
in water table elevations are factored into the
model.
Comparative figures are presented to provide
a quantitative understanding of the advances which
have been made in simulating saturated flow since
the inception of this program. Figure 5 shows the
measured Hanford ground-water potential distribu-
tion compared with the potential distribution
predicted by the VTT Model using a homoge-
neous permeability distribution and the Hanford
ground-water system boundary conditions. As can
be seen, the match in potentials is poor
over much of the Reservation. In addition, waste
movement calculated from such a potential distri-
bution would be highly inaccurate relative to
spatial locations and concentrations since the calcu-
lated flow paths and travel times would compare
poorly to actual values. The assumption of a
homogeneous permeability distribution has been
used in many areas because of the lack of methods
for economically obtaining a representative distri-
bution. This assumption has also been considered
for past models of the Hanford ground-water
system. However, since an accurate knowledge of
the direction and rate of the ground-water move-
ment is a prerequisite to accurately predicting
waste movements, a more representative distribu-
tion is necessary.
Figure 6 shows the same base map as in Figure
5 with the VTT Model output superimposed. In
this case a highly variable transmissivity distribu-
tion calculated from the streamtube program was
used (see Figure 2). As can be seen, the match of
ground-water elevations and the shape of the
ground-water contours is very good. The resulting
prediction of waste movement would be consider-
ably more accurate than in the first example and
represents a significant step toward obtaining the
objectives of this development program. The effect
of grid size and other variables on the match is
187
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Fig. 5. Measured and calculated Hanford ground-water con-
tours—homogeneous permeability.
Fig. 6. Measured and calculated Hanford ground-water con-
tours-calculated transmissivity.
under investigation. It is planned to use the Trans-
missivity Iterative Routine along with additional
transmissivity measurements that have been made
to further improve the calculated transmissivity
188
distribution. With the new distribution, an even
better match than that shown in Figure 6 is
expected.
Output from the VTT Model used on an
idealized test case is graphically shown in Figure 7.
The solution shows the computer generated transi-
ent development of a mound that would result
from discharge to a ground-water system.
INITIAL CONDITION
TIME • 0
TRANSIENT SOLUTION
TIME • 1 DAY
TRANSIENT SOLUTION TRANSIENT SOLUTION
TIME • 3 DAYS TIME • 13 DAYS
Fig. 7. Progressive change in ground-water surface resulting
from discharge of wastewater to the ground.
Water Quality Models
Development of methods for predicting con-
taminant movement is based on the transport equa-
tion which incorporates fluid movement and con-
taminant reaction components into one interrelated
equation. The transport equation is the analytical
tool with which the time-dependent, concentration
distribution of contaminants in saturated and un-
saturated soils can be predicted. In the case of the
nuclear industry, radionuclides of interest generally
occur in trace concentrations relative to naturally
occurring cations. By definition, trace ion sorption
of a specific ion is independent of other trace ion
concentrations. The trace ion movement is influ-
enced, however, by the macro-ions in the system.
Therefore, two transport models have been de-
veloped—one for describing the transient movement
of the macro-ions, and the other for describing the
transient movement of the trace (micro) ions. Both
models are valid in saturated and unsaturated sys-
tems. The models take into consideration the
influences of convective ground-water movement,
hydrodynamic dispersion, molecular dispersion,
-------
sorption and decay. For the sorption reaction used,
it is assumed that equilibrium conditions between
ions in liquid and solid phases exist.
Satisfactory numerical solutions to the con-
vective transport equation cannot be obtained using
standard techniques such as those used in the
hydraulic models. The method of characteristics
was used to obtain a two-dimensional numerical
solution. Both models are currently working and
are undergoing further testings and refinement.
The input data required for the water quality
models are the ground-water velocities (obtained
from the hydraulic models), the dispersion and
diffusion coefficients (which can be obtained from
laboratory and field tests) and the sorption coeffi-
cient. Other than convective transport, sorption is
the most important factor influencing waste move-
ment. The sorption coefficient (Kd) at any time or
spatial location is a function of the macro-ion
concentration (for Hanford these areMg2*,Ca2*, K",
and Na"), pH and soil sorptive characteristics.
Considerable soil-waste reaction work has been
conducted to determine the relationship of the Kd
and macro-ion concentrations. A soil-sorption
model, which solves the one-dimensional convective
transport equation for steady flow fields, was
developed to evaluate and refine these relation-
ships. Na*, K*, Ca*% and Mg" have been success-
fully handled by the use of ion exchange equations
that have been developed. The system can be
extended to other solution ions. Known carbonate
and sulfate precipitation and association equilibria
are used to predict these equilibria. The model has
also been used to evaluate the experimentally
determined sorption coefficients.
Since laboratory soil column work has been
conducted at Hanford for many years, the work
accomplished under this program can be readily
compared to the previous accomplishments. Figure
8 is intended to graphically indicate the progress
which has been made on radiocontaminant trans-
port through research on this program. A column
experiment was conducted using a fabricated waste
solution (typical of those encountered at Hanford).
The triangles shown in Figure 8 are the 85Sr relative
concentrations measured in the column effluent.
The dashed and solid curves represent predicted
values using the soil-sorption model. For curve 1,
it is assumed that the Kd is constant (the approach
used prior to the inception of this development
program); i.e. the Kd is independent of the macro-
ion concentrations. Curve 2 represents the break-
through using a Kd that is a function of macro-ion
concentrations. The Kd's can be obtained through
either small column or batch techniques. As can be
seen, significant errors in predicting radiocontami-
nant movement can occur if the Kd is assumed
independent of macro-ion concentrations. This
comparison shows that the approach being used
does an excellent job of describing the chemistry of
the soil-waste interactions.
Fig. 8. Relative concentration of 85Sr from a Burbank sand
subsoil column as a function of effluent volume.
Model Application
Concurrent to the development of the inte-
grated model system described above, a unique
man-machine interactive computer system has been
developed for use in application of the models to
field problems. The objective of this system is to
provide the tools with which an engineer, who is
not a computer expert, can analyze waste manage-
ment alternatives through efficient utilization of
the models previously described. Figure 9 is a
photograph of this system. From left to right are
(1) graphic digitizer, (2) CRT-light pen, (3) tele-
type, and (4) PDP-9 digital computer. The PDP-9
computer is being linked to a much larger Univac
1108 computer as shown in the schematic diagram
of the man-machine interactive computer system
in Figure 10. The dashed lines represent proposed
additions to the system. A high speed printer-
plotter is presently being added to the system.
Problems will normally be input to the computer
through one or more of the devices and transmitted
to the larger computer for calculation. The results
would then be transmitted back to the smaller
system for analysis and output.
The graphic digitizer is an input device which
permits input of analog data (maps, charts, etc.)
directly to storage in the PDP-9. This results in
extremely rapid and accurate input of information.
Input data changes can also be readily input with
this system without complicated revision ot the
originally stored information.
189
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Fig. 9. Photograph of the man-machine interactive com-
puter system.
COMPUTER NETWORK AND OAT* DISPLAY SYSTEM
UUK cowutei STSTEH
Fig. 10. Schematic diagram of the man-machine interactive
computer system.
The CRT is a device which displays problems
visually, and utilizing the light pen. the engineer-
operator interacts directly and in real-time with a
problem solution and analysis. The power of such a
system to the manager or engineer/user is difficult
to convey on paper. The problems are set up and
input in rapid and accurate fashion. Solutions are
obtained on a rapid turn around basis and dis-
played for the user. The user immediately is able to
evaluate the results, make changes and ask for new
solutions. Of particular importance is the ability to
inject the experience and knowledge of the user
into the problem solution. When an acceptable
solution is achieved, the results can be printed on a
line printer or plotter. This system development is
being carried out in conjunction with the model
development and will be fully operational at the
same time as the models themselves. The system is
already serving an important function in the model
development efforv .as mentioned earlier.
190
Fig. 11 (a). Reference map of the Hariford reservation.
Fig. 11 (b). Contours of the Hanford water table.
Fig. 11 (c). Flow paths and associated travel times.
Fig. 11. Computer generated displays associated with the
calculation of ground-water travel times.
-------
Figures 11 through 13 show some additional
photographs of displays generated on the CRT
display unit. Figure 11 shows the sequence the
engineer uses to instantaneously calculate ground-
water contours, flow paths and travel times. Figure
11 (a) shows the reference display of the reserva-
tion. In the contour mode the operator can plot
contours of either measured or predicted water
tables which are digitally stored on the disc unit
(Figure ll(b)). The values of the contours that
are plotted are input through the keyboard of the
display unit. Contours can readily be added or de-
leted by the operator. In the travel time mode, the
starting location of the flow path is input through
the digitizer. Then the flow path is instantaneously
calculated and displayed along with the associated
travel time (Figure 1 l(c)). The travel time displayed
on the CRT is associated with the last flow path
that was selected. With this program, the engineer
can rapidly assess the impact of management
alternatives on the water table elevation, flow paths
and travel times.
Fig. 12. Stereogram of an isometric view of the Hanford
ground-water surface.
Fig. 13. Stereogram of the Hanford ground-water surface.
Figures 12 and 13 are self-explanatory and
represent another form of output which is available.
These photographs were taken from a memory
scope display.
ACKNOWLEDGMENTS
The author would like to acknowledge the
engineers and scientists who were responsible for
the development of the integrated model and the
display systems: A. E. Reisenauer, hydraulic mod-
els; R. C. Routson and R. J. Serne, soil-waste inter-
relationships; A. Brandstetter and R. G. Baca,
transport models; D. R. Friedrichs, L. E. Addison
and H. P. Foote, data models and display programs;
L. H. Gerhardstein, system software; and R. D.
Mudd, general assistance. Although listed by their
major area of contribution, there was considerable
integration and combined effort in each of the
categories by the individuals listed above. The
author would also like to acknowledge the con-
tinued support of the program by the Atlantic
Richfield Hanford Company, especially R. E.
Isaacson, D. J. Brown and M. D. Veatch.
DISCUSSION
The following questions were answered by D. B.
Cearlock after delivering his talk entitled "A
Systems Approach to Management of the Hanford
Ground-Water Basin."
Q. Now that you have the models working, sup-
pose the power company came to you to do an
environmental impact analysis of waste discharge
from a planned nuclear reactor plant. Assuming
that only routine soil geological maps were availa-
ble for the area, how much time, about how many
man-years effort, would be required to apply your
analysis to this situation?
A. It is difficult to estimate the effort required
for a job without a more detailed elaboration of
the problem. The cost is directly associated with
the complexity and size of the ground-water basin,
the various components of the system of models to
be used and the limitation of the assumptions used
in the models. If simplifying assumptions can be
made and only a portion of the system of models
used, application costs would be considerably less
than if it was necessary to use the entire system as
described in the paper. As the complexity of the
system and the accuracy requirements increase, the
associated costs will increase.
Q. You indicated you have data to verify watei
movement and travel time. \Youid y>ii elaborate on
those data? And allied with that is this question.
What is your evidence that the impervious strata in
one of your slides arc really impervious?
A. A water quality surveillance program, which has
been conducted since the inception of the AEC
activities, has provided the data for verifying the
water movement patterns and the travel times. As
191
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mentioned in the paper, the agreement between
observed and measured movement patterns is good.
However, these verification results are preliminary,
and detailed laboratory and field verification stud-
ies are presently being conducted. Emphasis to
date has been directed predominantly toward
developing the complete system of models.
Both geologic and hydrologic data indicate
the existence of an impervious strata over much of
the project. Geologic data indicate the presence of
tight silt-clay layers although the continuity of
these layers has not been established.
Q. Here's another part of a question. Where is the
natural discharge of the lower aquifer?
A. This is being researched by ARHCO and USGS.
Q. Can your program solve other kinds or types of
tank failure in place of the rather unlikely sudden
removal of the whole tank bottom and would these
give significantly different results?
A. Other types of tanks and tank failures can be
modeled. The models were designed to be com-
pletely flexible so that, in general, any type of
tank leak or tank failure could be modeled. There
are about 25 different shapes of boundaries that
can be used in describing a tank facility.
^ After analyzing the results of the rupture of
the entire bottom of a tank, we believe a small leak
would result in faster penetration to the water table
and higher concentrations of nuclides in the ground
water if the leak were allowed to persist; however,
this is unsubstantiated by either modeling or
observations.
Q. Does your, or did the pumping well cause any
subsidences in the area of the plant and the storage
tank and, if so, what measures were taken to cor-
rect it?
A. The pumping wells we refer to are test wells
used for transmissibility determinations and are not
water-supply wells; hence, one should not antici-
pate subsidence.
Q. What methods would you use or will you use to
solve the differential equations for hydraulic dis-
persions in the natural system?
A. The transport equation is essentially a first
order equation since in ground-water systems, con-
vection is usually more significant than dispersion.
Therefore, use of numerical techniques for second
order equations can result in numerical dispersion.
To minimize numerical dispersion we have adopted
a hybrid approach first developed in the petroleum
industry. It involves using both Lagrangian and
Eulerian systems. The convective transport is solved
in the Lagrangian system and dispersion is solved in
a Eulerian system. We have tested the method
against analytical solutions and the agreement was
good.
Q. Are values of porosity and dispersion coeffi-
cients required for your models and, if so, how
were they determined and what is the sensitivity
of the model for variations in these parameters?
A. Both porosity and dispersion coefficients are
required in the model. We are presently using dis-
persion coefficients measured in laboratory soil
columns. At specific sites on the reservation, the
effective porosity has been estimated from travel
time data. We have not conducted sensitivity analy-
ses with respect to porosity and dispersion coeffi-
cients.
Q. Do you believe that our presently available
methods of obtaining reliable field data justify the
utilization of such elaborate mathematical models?
A. Yes. Otherwise we would not be developing the
models. The models are being used to identify
where additional data are required to improve the
understanding of the aquifer. Use of the models in
this way minimizes the collection of data that are
not directly useful in understanding the ground-
water system. This approach has substantial advan-
tages over the classical approach of conducting
extensive field measurement programs prior to
modeling the system. In addition, the preliminary
verification results presented in the paper are very-
encouraging.
Q. Can your analysis which now considers the
effect of ion exchange on ion transport also in-
corporate the effects of such processes as precipita-
tion and oxidation?
A. Yes. The model presently handles some precipi-
tation reactions. For these reactions it is assumed
that the precipitate does not alter the permeability.
Q. Isn't the porosity important for travel time? It
appears that only transmissivity was used.
A. Yes, porosity is important. We have been using
an effective porosity estimated from field measure-
ments and tests. We have also assumed the effective
porosity is constant over the entire project because
of the lack of data. The effective porosity has been
observed to be considerably less than the bulk
porosity in certain areas. However, these data are
limited.
Q. How much does the porosity vary?
A. The bulk porosity varies approximately be-
tween 30 and 45 percent. In contrast, the calcu-
lated permeability varies by 4 to 5 orders of magni-
tude. We do not have the data available to
determine how much the effective porosity varies.
192
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Salty Ground Water and Meteoric Flushing of
a
Contaminated Aquifers in West Virginia
by Benton M. Wilmoth
ABSTRACT
Salty ground water is commonly encountered at
relatively shallow depths of 100 to 300 feet beneath the
major stream channels in the western half of West Virginia.
Because of the wide distribution of salty ground water
and connate brine at various depths, it is difficult to
distinguish natural contamination from that caused by
subsurface industrial activities. Natural changes in quality
apparently are minor. The available historical data indicate
no large-scale natural variations in salt content during the
period of record. Histories of some water well developments
show unnatural large-scale increases in salt content from
various industrial activities that affect the fresh water zones.
Some records also reveal decreases in salt content after the
source of the salt was eliminated or after the subsurface
activity responsible for artificial migration of the salt water
was stopped.
Artesian brine contaminated a fresh water aquifer in
Fayette County. Chloride content changed from 53 mg/1 to
more than 1,900 mg/1 in a period of 5'/2 years. When pump-
ing was stopped, chloride content decreased to 55 mg/1 in
10 years.
Heavy pumping of well fields in Charleston during
1930 to 1956 accelerated migration upward of salt water.
Chloride content increased from less than 100 mg/1 to more
than 300 mg/1 in some wells and to more than 1,000 mg/1
at individual wells. Pumpage has declined greatly since 1956
and chloride content has decreased below 200 mg/1 at some
of the contaminated wells.
In an oil field of Kanawha County, a water well was
contaminated by salt water accelerated by subsurface activi-
ties. Chloride content increased from less than 100 mg/1 to
more than 2,900 mg/1 within 2 months. After the oil-field
activity was curtailed, chloride content decreased to 190
mg/1 in about 2'/i years. Road salt piles contaminated a
carbonate aquifer in Monroe County. Chloride concentra-
tions in wells located 1,500 feet from the piles increased
from 185 mg/1 to 1,000 mg/1 in 5 years. The greatest change
was 1,000 mg/1 in 1969 to 7,200 mg/1 in 1970 when the
salt storage area was enlarged. All salt piles were removed in
late 1970 and within 2 months chloride content decreased
to 188 mg/1.
One of the most difficult problems in sub-
surface hydrology is to predict the movement of a
contaminant in ground water when concentrations
are decreased by dilution. The problem is further
complicated if the contaminant, such as salt water,
Presented at the National Ground Water Quality
Symposium, Denver, Colorado, August 25-27, 1971.
^Geologist, Environmental Protection Agency, 303
Methodist Building, Wheeling, West Virginia 26003.
also occurs naturally in adjacent aquifers at a wide
range of concentrations, velocities, and depths.
Consequently to determine when salt water has
occurred naturally and when it is the result of sub-
surface industrial activities is a formidable task.
Predictions of future subsurface conditions are
likewise extremely difficult.
Sedimentary rocks of Pennsylvanian and Per-
mian (?) ages of the western half of the State form
a complex, alternating series of conglomerate, shale,
siltstone, limestone, and coal strata. The rocks are
gently folded along subparallel axes that trend
generally northeastward. These flexures tend to
obscure the general regional dip of the rocks to the
northwest. Because of the folding and subsequent
erosion, some of the older brine-bearing rocks are
close to the land surface along the axial centers of
major anticlines. Although ground water has been
obtained at depths of more than a mile, test holes
usually encounter little water below 2,500 feet.
This is about the top of the zone of rock flowage
where the weight of the overlying rock column
tends to close pore space.
The majority of the shallow rocks that are
weathered and fractured at depths ranging from 25
to 300 feet yield ground water. The major devel-
oped aquifers and most of the ground-water
pumpage are within this zone. Intergranular or
primary permeability and fracture or secondary
permeability both contribute to shallow ground-
water occurrence but little evidence is available to
indicate the predominant form. Sandstone and
conglomerate usually have the highest permeability
because either the primary permeability is pre-
dominant or the secondary permeability is de-
veloped to a larger degree. These are the pre-
dominant water-bearing rocks. Highly fractured
sandy shale within 100 to 300 feet of the land
surface can also yield moderate amounts of ground
water. Minor beds of thin nodular limestone, fire
clay, and coal are aquifers in local areas only.
Large areal exposures of limestone and dolo-
mite in the eastern part of the State are excellent
major aquifers. In general, throughout the State,
aquifers that are considered practical at the present
time for development lie within about 500 feet of
193
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the land surface; however, the average depth of
existing wells is still only about 125 feet.
Meteoric fresh ground water moves by gravity
from upland intake recharge areas through fractures
and interstitial openings in a very complex flow
system. The configuration of flow through various
kinds of stratified rocks with complicated vertical
and lateral hydrologic boundaries can only be
generalized. The ground water may remain only a
few days in the shallow rocks before it is discharged
as springs or seepage; or it may recharge deep
artesian reservoirs and remain for many thousands
of years becoming more mineralized with time.
The velocity of flow may range from a few inches
to several hundred feet per year.
Although some ground water in the outcrop
areas of aquifers is unconfined, artesian conditions
exist below where the water becomes confined and
is known to exist at depths of more than 2,000
feet. The water-bearing rocks form a series of aqui-
fer systems, each composed of several hydraulically
connected beds. The amount of hydraulic connec-
tion ranges from direct or free to very little, due to
relatively impermeable intervening formations.
If the stream channels of the western half of
the State act as sumps for the natural discharge of
^both fresh and salty ground water, the interface or
top of the salty ground water apparently tends to
"cone up" toward the stream and then lie at
successively greater depths with increasing distance
away from the valley beneath the hills and ridges.
The saturated, unconsolidated alluvium bor-
dering the major river valleys also contains salt
water in certain areas. Segments of former stream
channels in the bedrock of present major valley
floors are filled with highly permeable sand and
gravel of Pleistocene age. These sand-and-gravel-
filled depressions along the Ohio River Valley in
Cabell, Tyler, Brooke, and Hancock Counties ap-
parently are intercepted by the salt water migrating
from the underlying bedrock.
Usually, the shallow saturated rocks contain
the fresh meteoric ground water, and the rocks
below contain the salty ground water. The shallow
salty ground water is essentially a zone of diffusion
or mixing between the fresh ground water and the
deep connate brines. These fluids generally cut
across geologic contacts in response to natural
hydraulic conditions or to the changes in condi-
tions imposed by subsurface industrial activities.
Chemical character of fresh ground water is
controlled primarily by the chemical composition
of the soluble rock minerals of the aquifers. Conse-
quently, both local and regional lithologic differ-
ences can produce differences in the chemical
quality of ground water. Fresh ground water con-
tains less than 1,000 mg/1 of dissolved solids,
whereas shallow salty ground water usually con-
tains 1,000 to 3,000 mg/1 of dissolved solids. Fresh
ground water from shallow bedrock aquifers is
chemically suitable for most domestic uses. The
water is mostly of the calcium, sodium, or magnesi-
um bicarbonate type and is alkaline, but the en-
croachment of brine into the fresh-water aquifers
changes the water to a sodium chloride type.
In most areas of the western half of the State,
the salty ground water occurs 100 to 300 feet be-
low the altitude of the major stream channels. The
chloride concentration of the ground water con-
tinues to increase with depth as the flushing effect
of the circulating fresh meteoric ground water
diminishes. At depths of 1,000 to 5,000 feet, highly
concentrated brines containing 30,000 to 100,000
mg/1 of total dissolved solids are encountered
(Price, Hare, McCue, and Hoskins, 1937, pp. 28-32).
These brines were derived from sea water trapped
in the original rock-forming sediments. At these
depths, the natural migration is extremely slow.
The various processes of chemical concentration
and modification of the sea water are not com-
pletely understood.
In totally undeveloped areas, where there has
been no deep drilling, the natural vertical migration
of salt water apparently is extremely slow. Perhaps
any natural changes in the quality of both fresh
and salty ground water in these areas are minor
over several hundred years. The few historical data
available for specific aquifer areas indicate no large-
scale natural variations in salt content during the
period of record (Wilmoth, 1970). Much salt-water
migration into shallow rocks, therefore, is a natural
phenomenon from a very long period of inter-
formational seepage of artesian brine out of deep
formations. Apparently, this migration has occurred
over several million years of geologic time.
Salt water seeps and springs in several counties
were used by the Indians and the pioneer settlers to
obtain salt. The best known occurrence of salt
water discharged as natural springs is in the
Kanawha River valley near the mouth of Campbell's
Creek at Maiden, Kanawha County. Here a major
geologic structure, the Warfield anticline, caused
geologically older brine-bearing rocks to crop out.
Historical records (Summers, 1935) show that these
salt water springs were used by the Indians in the
1700's. Archeological evidence indicates they used
brine as early as the year 1000, but they may have
obtained brine or salt in the general area for more
than 10,000 years (Broyles, Betty, personal com-
munication). The early settlers in Kanawha River
valley improved the springs and later made crude
drilling explorations in the area by means of tilt
194
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pole rigs. Deep drilling methods and equipment
were improved before the Civil War, and large
amounts of salt were produced in the valley (Howe,
1845). Most of the brine was obtained from deep
wells tapping the Pottsville Group at depths of
several hundred feet.
All of the conditions which made fresh
ground-water aquifers vulnerable to the encroach-
ment of salt water are not known. The best in-
formation is obtained from records at fresh water
well developments which experienced salt water
encroachment after many years of successful opera-
tion. While the subsurface environment of these
areas cannot be described accurately, it is possible
to define the general occurrence of the salty
ground water and its relation to the fresh ground
water. In some areas, deep drilling and related sub-
surface industrial activities have merely accelerated
the vertical and lateral migration of natural forma-
tion fluids. Consequently, these fluids are now
present in certain shallow aquifers in greater
quantity and concentration than under the original
natural conditions. In the past few decades rapid,
unnatural, salt water migration toward the land
surface has been mostly by vertical leakage along
hundreds of unplugged wells and test bores. These
holes were put down during exploration for brine,
oil, gas, water, and coal. Commonly, the holes were
abandoned uncased and improperly plugged. The
formation fluids of brine and related hydrocarbons
flowed up the holes in response to the artesian
pressure under which they were confined. These
essentially open holes can act as nearly infinite
vertical rock permeability and the natural protec-
tion from rapid fluid migration offered by thick
sequences of shales and other confining strata is
lost. In many areas, salt water under artesian pres-
sure has migrated into developed fresh water aqui-
fers when casing was removed from an abandoned
deep well.
Because of the extensive distribution of brine
and salty ground water at a wide range of depths in
the western part of the State, it is difficult to
determine how much of the salt water occurs
naturally and how much has been accelerated arti-
ficially by subsurface industrial activities. Salt water
can leak and build up for many decades immediate-
ly below a fresh-water aquifer and still not pose a
problem to shallow drilled domestic water wells
pumped at low rates. However, waste brine dis-
posal, water flooding, repressuring, or hydraulic
fracturing can trigger the salt water encroachment
of these fresh water zones. Solutions to and re-
medial actions for such contamination problems
become more difficult with greater distances of
aquifer area and longer periods of time involved.
Most areas of consolidated sedimentary rocks
are underlain by two or more aquifers in which
water levels are of quite different elevation. As a
result, some natural seepage or leakage occurs
between the various aquifers. A lower artesian
pressure in an aquifer indicates that ground water
from an overlying or underlying aquifer of higher
pressure may move into it through confining beds.
The direction of this natural interformational
leakage can also be reversed by pumping and
changing of heads in the aquifers. High-capacity
pumping from fresh water zones may lower the
head in the rocks to levels below the artesian head
of the salty ground water. The salt water may then
migrate into the fresh water aquifer if the zones are
hydraulically connected.
Records of ground-water quality in the bed-
rock aquifers at Charleston, Kanawha County indi-
cate that withdrawal of large amounts of fresh
water was a significant factor in the accelerated
encroachment of salt water. From 1930 to 1956
pumpage of ground water was heavy, and salt water
encroachment was accelerated (Figure 1). The
maximum withdrawals occurred during 1940 to
1950 (Wilmoth, 1965). Chloride content of ground
water increased from less than 100'mg/l to more
than 300 mg/1 in several well fields and to more
than 1,000 mg/1 at individual wells (Wilmoth,
1970). Pumpage gradually declined from 1956 and
by 1966 was extremely small with only periodic
use of one or two wells. Chloride content of ground
water at some of the contaminated wells had de-
creased below 200 mg/1 by 1970 (Figure 2). This is
about 14 years from the last year of heavy ground-
water pumpage.
Extensive areas of fresh ground-water aquifers
have been contaminated by vertical migration of
artesian salty ground water into fresh water through
unplugged test bores and improperly abandoned
wells. In Fayette County, the chloride content of
ground water in a fresh water sandstone aquifer of
the Pottsville Group increased from 53 mg/1 to
more than 1,900 mg/1 within 5Vz years (Figure 3).
Pumpage in the aquifer was essentially stopped
when the principal water well was shut down be-
cause of the high salt content. Pumping of the
well apparently helped to accelerate the contamina-
tion, because within about 10 years natural mete-
oric flushing had reduced the chloride content to
55 mg/1 in part of the aquifer.
In an area of Kanawha County the secondary
recovery of oil by water flooding has resulted in a
higher piezometric level of the brines in rock units
below the fresh water aquifers. This has caused an
accelerated migration of the brine upward into the
fresh water.
195
-------
600*-
400'-
rWater well fields in Charleston
1000 feet -
Average depressed piezornetric surface 1950
Kanawho
River
Explanation
Clay and silt Sand and gravel Shale Sandstone
Fig. 1. Changes in elevation of salt water interface, Charleston, Kanawha County.
prni
i i i
Limestone
2OOO
ISOO —
1000 —
soo—
~>9ia I92C 1930 B4O 1950 I960 S7Q
Fig. 2. Changes in chloride in ground water from over-
development of aquifer, Charleston, Kanawha County.
Fig, 3. Changes in chloride in ground water from open-hole
migration of artesian brine, Fayette County.
Unnatural fluctuations in chloride content
were observed in ground water from several wells
in this area. The fluctuations in quality apparently
are related to the rate and pressure of brine injec-
tion. In one domestic water well supply the natural
chloride content in 1967 was 32 mg/1. Shortly after
secondary- recovery of oil was started the chloride
concentrations began to increase. Within 9 months
the chloride content had increased to 250 mg/1,
and within 11 months the concentration was 1,140
mg/1 (Figure 4). After this maximum chloride
level was reached, the concentrations began an
uneven but rather steady decline. After 2l/2 years of
general decline the chloride content was 450 mg/1
early in 1971. Apparently changes were made in
the repressuring operations in the oil field. Then
196
-------
v iOOO —
500 —
1967 1968 1969 1970 1971
Fig. 4. Changes in chloride in ground water from repressur-
ing of oil field, Kanawha County.
natural meteoric flushing of the shallow aquifers
helped to remove enough of the chloride for the
wells to be utilized.
Oil field operations also caused salt contami-
nation of a fresh water aquifer near Wallace,
Kanawha County. In late 1967 the natural chloride
content of the aquifer was 100 mg/1. Within 2
months after the start of the subsurface oil well
operations, the chloride content reached 2,950
mg/1 (Figure 5). The oil well operation was altered
and chloride concentration began to decrease rapid-
ly. Within 2 months the concentration was 950
^
mg/1. During the next 2'/2 years the chloride content
declined to 190 mg/1.
In the oil fields of Roane County, pressure
injection disposal of produced waste brine into the
3000
2SQO
?000h-
1500
iOOO
500I—
1967 1968 1969 «70
Fig. 5. Changes in chloride in ground water from oil well
operations, Kanawha County.
Salt Sandstone of the Pottsville Group has raised
the piezometric level of the natural brine in this
formation. Because the overlying shallow fresh
water zones are hydraulically connected to the
injection zone, there has been extensive damage to
the fresh ground water. In some areas, brine con-
tamination has been rapid with chloride content
increasing from less than 25 mg/1 to more than
1,500 mg/1 within several months. Unnatural cyclic
changes in quality have occurred in many private
ground-water supplies. In one part of a fresh water
aquifer, the chloride concentration of less than 50
mg/1 increased to 1,150 mg/1 in a period of 19
months (Figure 6). After the subsurface oil-field
brine disposal operations were altered, the chloride
content declined to 68 mg/1 within 17 months.
Fig. 6. Changes in chloride from pressure injection of brine,
Roane County.
Soluble chemicals such as highway deicing salt
are causing the deterioration of ground-water quali-
ty in certain shallow fresh water aquifers in the
State. Chemical analyses show unnatural cyclic
changes in chloride content. Although the aquifer
areas of deteriorated water quality are local, re-
ported incidents of such contamination are increas-
ing every year.
The amount of salt used annually for ice and
snow control on highways continues to increase.
This highly soluble material is now being recog-
nized as a contaminant that easily migrates into
shallow fresh water aquifers with natural recharge.
In several States, water quality control specialists
are observing possible cumulative effects of the
salt load on the hydrologic system (Walker, 1971).
Apparently most of the salt is transported during
thaw periods by runoff to the nearest stream and is
progressively diluted downstream. Chloride concen-
197
-------
trations of more than 10,000 mg/1 have been ob-
served in the runoff from heavily salted areas of
Grant and Raleigh Counties. Salt carried by natural
recharge may require several months or years to
percolate to aquifers and move laterally to pumping
water wells. Although the actual risk of contamina-
tion from salt spreading is not known at this time,
it is estimated that more than half of all the water
wells in the State are located within 100 to 500
feet of a road that receives some salt treatment.
Shallow fresh water aquifers in carbonate rock
terrane are developed extensively for rural farms
and businesses in the eastern part of the State.
The principal source of recharge is precipitation
which enters the aquifer via solution crevices and
sinkhole depressions. The rate of travel from re-
charge areas to water wells may be rapid with very
little filtration occurring. Potential contamination
of such aquifers should be suspected it the ground-
water turbidity increases after heavy rainfall.
An unusual ease of salt contamination ot
fresh ground water from the land surface occurred
near Union, Monroe County. The history of water
quality in this area illustrates the high contamina-
tion risk of shallow carbonate aquifers. There is no
natural near-surface salty ground water in the area,
nor any gas wells or other deep drilling. Partial
chemical analyses indicate that the natural chloride
content of the fresh ground water in the area
averages about 25 mg/1.
Several hundred tons of rock salt stored di-
rectly on *he land surface were also unprotected
from precipitation and runoff. Water wells located
about 1,500 feet laterally and downgradient were
subsequently contaminated with such high concen-
trations of chloride that the water was unfit for
use. The chloride concentration in one water well
steadily increased to 1,000 mg/1 in about 5 years
(Figure 7). The period of greatest change was
1,000 mg/1 in 1969 to a high of 7,200 mg/1 in
1970. The wells in this area are 73 to 79 feet deep
and tap highly permeable fractured and solutioned
carbonate aquifers. The natural gradient of the
water table was from the salt storage area toward
the wells. The contaminated ground water moved
downgradient through the aquifer toward points of
natural discharge. Interception of the flow by the
pumping wells resulted in extreme degradation of
several supplies. In late 1970, the salt was removed
from the ground and stored in a protective building.
During the 2 months following the salt storage
removal, chloride concentrations in the monitored
contaminated well decreased to 188 mg/1.
In Grant County, an investigation was made of
salt contamination of a shale aquifer tapped by a
drilled well 160 feet deep. Apparently the con-
8000
i965 197O
Fig. 7. Road salt contamination of ground water, Monroe
County.
tamination in this well was from the spent salty
backwash from a zeolite water softener, which dis-
charged into a dry sump located upgradient from
the water well. Natural ground-water recharge
carried the salt downgradient toward the pumping
well. The natural chloride content of the ground
water in this aquifer was determined in 1962 to be
9 mg/1. Within 16 months after the zeolite water
treatment unit was installed, chloride content had
increased to 580 mg/1 (Figure 8). Early in 1970,
some 3 years after the brine was periodically dis-
charged to the sump, the chloride content had
reached 1,650 mg/1. Early in 1970 the treatment
unit was shut down and brine disposal was stopped
for several months. Within a few weeks, the rate
of change in chloride content was decreased sig-
nificantly. From January 1971 to May 1971. the
chloride content actually declined from 1,712 mg/1
to 1,650 mg/1.
Because the records of some salt-contaminated
well developments show decreases in salt content
after the source of the salt was eliminated, there is
2000
1962 1965 1970
Fig, 8. Contamination of ground water from brine disposal,
Grant County.
198
-------
reason to consider remedial work in certain un-
naturally contaminated aquifers.
If the abandoned wells and test bores could
be properly plugged and cemented, the source of
the salt water should be effectively stopped. There-
after, the natural meteoric ground-water recharge
to the fresh water zones should eventually flush out
the salt water. Then pumping of the water wells
tapping the aquifer should actually accelerate the
flushing action.
Because the ground-water aquifer is not seen
at the land surface, much pollution often occurs
before it is known. The public is often unaware
that certain industrial activities or incorrect pump-
ing can pollute aquifers. The single most important
aspect of ground-water quality control is the pre-
vention of contamination rather than attempts to
correct problems after they occur. Public education
for constant surveillance of activities that can result
in contamination is certainly an important need to
be considered.
REFERENCES
Howe, Henry. 1845. Historical collections of Virginia.
Babcock & Co., Charleston, South Carolina.
Price, P. H., C. E. Hare, J. B. McCue, and H. A. Hoskins.
1937. Salt brines of West Virginia. West Virginia
Geological and Economic Survey, 203 pp.
Summers, G. W. 1935. Pages from the past. Summers
Publishing Co., Charleston, West Virginia.
Walker, W. H. 1971. Limiting highway salt pollution of area
water supplies. Rural and Urban Roads.
Wilmoth, B. M. 1965. Natural equilibrium in ground-water
storage re-established at Charleston, West Virginia.
Proc. West Virginia Academy Science, v. 37, pp. 167-
173.
Wilmoth, B. M. 1970. Occurrence of shallow salty ground
water in West Virginia. Proc. West Virginia Academy
Science, v. 42.
DISCUSSION
The following questions were answered by Benton
M. Wilmoth after delivering his talk entitled "Salty
Ground Water and Meteoric Flushing of Contami-
nated Aquifers in West Virginia."
Q. In the example where the water softener dis-
charge was recycled, what was the original hardness
of the water?
A. I don't remember exactly, but it was less than
200 mg/1. The well at this facility taps a shale
aquifer.
Q. Does West Virginia have a regulatory agency at
present to insure the adequate construction of oil
wells and brine pits for the protection of potable
ground and surface water supplies, and, if not, why
not?
A. Yes, the State has the Division of Oil and Gas
that regulates oil and gas well construction, opera-
tion, and abandonment. The State Division of Water
Resources is charged with protection of the water
resources.
Q. / think each of us from our own States recog-
nizes that we have a legal authority, but sometimes
we don't have the enforcement personnel to do the
job the law says we can do. Here's a question. Why
were your brine heads converted to fresh water
equivalents?
A. This was done for diagrammatic purposes to
illustrate how the head of the salty ground water
does override the head of the fresh water zones
under certain hydrogeologic conditions.
Q. In one of your slides showing the close relation-
ship of oil and saline shallow ground water, was the
oil production from the shallow Pennsylvanian
sands or from the deeper-zones?
A. Oil production was from the deeper Big Injun
formation of Mississippian age. Some abandoned
holes must be hydraulically connected to the
shallower Salt Sandstones of Pennsylvanian age,
because some holes are uncased and other holes
have deteriorated casing.
Q. Have you been able to map or identify most of
the natural discharge area for the brine and map the
natural regional movement for the brine?
A. No, at present we merely know general areas
where brine is discharged. There is a cooperative
study by the State and Federal Geological Surveys
to map the salt water—fresh water interface. This
should be of significant aid to the Division of Oil
and Gas in regulating the casing and cementing of
new wells.
Q. What do you consider to be the future for
ground-water use in the Kanawha River Valley and
will significant development be possible in view of
the problems?
A. At present we are limited to the relatively
shallow consolidated aquifers for ground water not
high in chloride. Yields of 50 to 200 gpm are availa-
ble at depths of about 150 feet. The unconsolidated
alluvium produces 50 to 150 gpm to standard
vertical screened wells in selected places between
199
-------
Charleston and Point Pleasant. Higher yields of 200
gpm may be available in downstream areas of
Mason County.
Q. One of your slides showing the occurrence of
saline ground water showed that it was shallow in
the western half of the State and deeper in the
eastern half. Is the reason that there is no shallow
saline ground water in the eastern half of the State
because the bedrock contains no shallow aquifers
there, or because the water is fresh there?
A. The history of ground-water development shows
that deeper aquifers in the eastern part of the State
contain fresh water. Apparently the natural salty
ground water is nearer the land surface towards the
Ohio River area which limits fresh ground water to
the relatively shallow zones.
Q. Was the surface soil removed from the chloride
storage sites to speed the recovery of the aquifer?
A. I doubt it. I believe that the storage areas were
swept clean of solid salt with brooms. New salt
storage facilities will be protective sheds, perhaps
with impermeable floors. Also some salt may be
stored in plastic bags.
Q. Here's a question that has to do with so-called
impermeable zones. Was the shale heavily fractured,
or did the chlorides readily move through these
"impermeable " zones?
A. Most of the shale was very heavily fractured.
The silty shale or sandy shale, almost always will
produce water. Certainly not as much as sandstone,
but enough for domestic supplies.
200
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Probable Impact of NTA on Ground Water
by William J. Dunlap, Roger L. Cosby, James F. MclMabb, Bert E, Bledsoe, and Marion R.
ABSTRACT
Laboratory studies were employed to investigate the
fate and effect of NTA both in ground waters and in soil
profiles overlying ground waters.
Studies of the sorption of NTA by sand, loam, and
clay-loam soils indicated that sorption of NTA on soils
could slow its movement into and through ground waters.
Sorption will probably not be sufficient to prevent or
greatly reduce potential pollution of ground water by NTA
used as a detergent builder.
Soil column studies were employed to investigate
the degradation and effect on metals of NTA infiltrating
through soils. These studies indicated: NTA infiltrating
through most unsaturated soils likely would undergo rapid
and complete degradation and contribute only inorganic
nitrogen compounds and carbonate to ground waters; NTA
infiltrating through saturated soils would probably experi-
ence only very limited degradation, with a major portion
entering ground water intact; any NTA which escaped
degradation during infiltration through soils could transport
such metals as iron, zinc, chromium, lead, cadmium, and
mercury from soils into ground waters.
Studies with model aquifers constructed from natural
aquifer sand indicated that NTA would likely undergo slow
degradation in essentially anaerobic ground-water environ-
ments, with production of CO2, CH4, and possibly other
organic compounds.
INTRODUCTION
Ground waters in the United States are being
increasingly subjected to possible pollution by a
wide array of synthetic organic chemicals entering
the environment as a result of the needs and de-
mands of modern society. Nitrilotriacetic acid
(Figure 1) is a synthetic organic compound worthy
of special concern in regard to its possible impact
on ground water because of the magnitude of
potential usage of this compound, both from the
standpoint of quantity and geographical distribu-
tion.
Nitrilotriacetic acid (called NTA) is currently
the leading candidate to replace the condensed
phosphates now used as "builders" in the formula-
tion of synthetic detergents. Elimination of phos-
phates from detergents is sought because of their
probable contribution to the eutrophication prob-
lem plaguing many of our surface waters. If NTA
0
II
HO-C
aPrepared for the National Ground Water Quality
Symposium, Denver, Colorado, August 25-27, 1971.
^National Ground Water Research Program, Environ-
mental Protection Agency, Office of Research and Monitor-
ing, Robert S. Kerr Water Research Center, Ada, Oklahoma
74820.
^x
o
N-CHo-C
\
/
0=C
i
OH
Fig. 1. Nitrilotriacetic acid.
were to replace only half of the condensed phos-
phates currently used in detergents in the United
States, over a billion pounds of this substance
would appear in our waste waters annually. Fur-
thermore, the intended use of NTA in detergents
would insure its distribution throughout the Nation
and provide ample opportunity for entry of this
substance into ground waters.
NTA from detergents could possibly enter
ground water both by infiltration through the soil
mantle above the water table and discharge directly
into the ground water. The first pathway would be
operative in cases where waste waters are dis-
charged to permeable soils appreciably above the
water table, such as in properly designed and oper-
ating septic systems, waste lagoons, and related
sewage spreading systems. The second pathway
would be followed in the all too frequent situations
where septic systems, lagoons, and similar waste
disposal systems are connected directly to ground
waters, and also in cases of direct artificial recharge
of aquifers.
Both during infiltration through the soil man-
tle and upon entry to the ground-water environ-
ment below the water table, NTA would be subject
to possible sorption by soil particles and microbial
degradation. Also, since it is an exceptionally effi-
cient chelating agent, NTA might also react with
metals present in the soils to form soluble metal
chelates. Therefore, answers to the following
questions are needed in order to assess the probable
impact on ground water of large scale use of NTA
in detergents.
1. How will sorption affect the infiltration of
201
-------
NTA through soil profiles and its movement within
ground-water aquifers?
2. To what extent will NTA be degraded dur-
ing infiltration through unsaturated and saturated
soils and within essentially anaerobic ground-water
environments?
3. If NTA is degraded during infiltration
through soil profiles or within ground-water en-
vironments, what will be the nature and fate of the
degradation products?
4. To what extent will NTA affect the trans-
port of metals into and through ground water?
This report describes a research project under-
taken in an effort to provide answers to these
questions. The project was part of a relatively short
term but intensive effort by the Environmental
Protection Agency to evaluate the environmental
acceptability of NTA before its large scale use in
detergents is begun, and research was therefore
limited to a laboratory investigation consisting of
three phases conducted more or less concurrently.
The first phase of the investigation involved study
of the sorption of NTA by typical sand, loam, and
clay-loam soils. In the second phase, soil column
studies were employed to investigate the possible
degradation and effect on metals of NTA infiltrat-
ing through saturated and unsaturated soils. In the
third phase of study, the possible degradation of
NTA in an essentially anaerobic ground-water en-
vironment was investigated using simulated aquifers
constructed in the laboratory from natural aquifer
sand.
SORPTION STUDIES
Sorption of NTA by soils was investigated by
laboratory sorption studies employing a sand, a
loam, and a clay-loam soil in order to broadly span
the various soil types which might be encountered
in natural situations. The soils used, all of which
were obtained in the vicinity of Ada, Oklahoma,
were identified by the United States Department
of Agriculture Soil Conservation Service soil sur-
veys as Konawa loamy fine sand, Claremore loam,
and Burleson clay loam. :
Solutions of the trisodium salt of NTA
(NTA Na3) uniformly labeled with carbon-14 were
utilized in the sorption studies as well as in the
other phases of this investigation. Soils were placed
in contact with various concentrations of 14C-
NTA Na3 in Erlynmeyer flasks and the mixtures
were agitated at 20° C until equilibrium was at-
tained. Concentrations of NTA Na3 in the solu-
tions at equilibrium and quantities of NTA Na3
sorbed by the soils in contact with these solutions
were determined by liquid scintillation spectrome-
try. Sterile solutions and soils as well as aseptic
techniques were employed throughout the sorption
studies to eliminate the possibility of errors due to
microbial degradation of NTA.
The data obtained for sorption of NTA on the
soils utilized in this investigation were best de-
scribed by means of the Freundlich adsorption iso-
therm, as shown in Figure 2. Greatest sorption was
evidenced by the loam soil, with the sand being
least effective. At an equilibrium concentration of
50 mg/1 of NTA Na3 in water, sorption values for
the loam, clay-loam, and sand soils were 64, 28,
and 8.7 Mg NTA Na3 per gram of soil, respectively.
Analogous data at 5 mg/1 NTA Na3 were 10.2
3.5A/g/g, and 0.98 Mg/g.
sorption - •
NTA
9 soi I
brium Concentration - mg/1
•e empirical constants
40 60 60 100
C (mg/1 NTANOj)
Fig. 2. NTA sorption; Freundlich isotherm at 20°C.
These data indicate that under some circum-
stances sorption of NTA by soils could consider-
ably retard movement of this compound into
ground water and within aquifers. Nevertheless, as
an individual mechanism, sorption of NTA by soils
does not appear to be sufficient to greatly reduce
the potential pollution of ground waters by this
compound over the course of ,its long-term usage
as a detergent builder. However, by retarding the
movement of NTA in soils and hence effectively
increasing its residence time in regions of high
microbial activity, sorption may play a significant
secondary role in the removal of NTA from infil-
trating waters by microbial degradation.
SOIL COLUMN STUDIES
Studies Employing Natural Soils
Initial soil column studies were concerned
with the possible degradation of NTA during infil-
202
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tration through unsaturated and saturated Konawa
loamy fine sand, Claremore loam, and Burleson
clay-loam soils'and the effect of NTA on the metals
native to these soils. The soils were packed into
4-inch O.D. X 4 feet borosilicate glass- columns to
produce columns of soil which were 3.75 inches in
diameter and averaged 39 inches in height. Two
columns of each soil type were prepared, with one
being operated under unsaturatedv or aerobic, con-
ditions with the water table near the bottom of the
column, and the other being operated under
saturated, or essentially' anaerobic, conditions by
maintaining the water table near the surface of the
soil. Loam and clay-loam columns are pictured in
Figure 3.
Fig. 3. Loam and clay-loam soil columns.
Columns were dosed daily for 58 days at a
hydraulic loading of 2 gal/ft2 (580 ml/day for
each column) with a weak synthetic sewage pre-
pared from the liquid diet food Sego, 14C labeled
NTA Na3, and distilled water. The synthetic sew-
age contained approximately 50 mg/1 both of BOD
and NTA Na3 and had a specific'activity of 900
pCi/ml. Upon completion of the initial 58 days of
operation, dosing of the soil columns was con-
tinued for 19 "additional days with synthetic sewage
containing no NTA in order to better observe the
effect of NTA on the soil metals.
Column effluents were analyzed daily for
NTA Na3 by the automated zinc-zincon method
(Thompson and Duthie, 1968) and for 14C by liq-
uid scintillation spectrometry. Selected effluents
were also subjected to thin-layer chromatography
and radioautography to detect intermediate organic
degradation products of NTA. Effluents were
examined initially by emission spectroscopy for
evidence of metal increases. Those metals observed
to increase significantly were then determined
quantitatively by atomic absorption spectropho-
tometry, employing standard procedures (Federal
Water Pollution Control Administration, 1969).
As shown by Figures 4 and 5, essentially no
NTA was detected in effluents from the unsaturat-
ed loam and clay-loam columns at any time during
the 77 days of operation, even though approxi-
mately 29 mg of NTA Na3 were applied daily to
each column. NTA was present in the effluent from
the unsaturated sand column from the 2nd through
the 9th day of operation, with a peak level near
feed concentration occurring on the 5th day, but
had virtually disappeared from this effluent by the
10th day and was not again detected as an effluent
constituent (Figure 6). Significant quantities of 14C
__ K>
'
jffttt Lnfl, NTANo^ »^ ^C^
10 30
5O 60 70
Days of Operation
Fig. 4. NTA, I4C, and metals in effluent from unsaturated
loam column. .
not accountable as NTA were found in the efflu-
ents from all 3 columns during most of the period
of operation, thus confirming the occurrence of
NTA degradation- in the columns. The early pres-
203
-------
ence and subsequent disappearance of NTA in the
sand column effluent undoubtedly reflected a short
acclimation period required for establishment with-
E
m
a*no-
/ Xc
/ N
/ f™ ^
j iO 20 50 40 50 60 70
Days of Operation
Fig. 5. NTA, "*C, and metals in effluent from unsaturated
clay-loam column.
30 40 5O 60 ?0
of Op«ro!ion
Fig. 6. NTA, !4C, and metals in effluent from unsaturated
sand column.
in the soil of a microbial population capable of
degrading NTA. Because of the greater sorptive
power of the loam and clay-loam soils, the move-
ment of NTA in these columns was probably
retarded sufficiently that acclimation and subse-
quent degradation occurred before any NTA trav-
ersed the lengths of these columns.
Thin-layer chromatography and radioautog-
raphy studies revealed no organic degradation
products of NTA in effluent samples from any of
the unsaturated soil columns. Radioanalysis of gas
released when effluent samples were acidified indi-
cated that virtually all of the 14C present in efflu-
ents from all 3 columns was incorporated in CO2 .
These data indicate that NTA infiltrating
through unsaturated soil systems probably will
undergo rapid and complete degradation, with the
only products likely to enter ground waters as a
result of such degradation being CO2 and probably
inorganic nitrogen compounds. The introduction
of additional carbon and nitrogen into ground
waters is certainly less than desirable, but the mag-
nitude of the addition likely to result from the
projected use of NTA in detergents is probably
not sufficient for critical concern.
NTA and 14C appeared in effluents from the
sand and loam columns operated under saturated,
or essentially anaerobic conditions on the 4th and
llth days of operation, respectively (Figures 1 and
8). After attaining concentrations near or some-
20 30 40 SO SO
Days of Operation
Fig. 7. nJAt 14C, and metals in effluent from saturated sand
column.
204
-------
Days of Operation
Fig. 8. NTA, 14C, and metals in effluent from saturated
loam column,
what exceeding the feed level (50 mg Na3 /I) during
the early phases of column operation, NTA Na3 in
effluents from these columns remained within the
range of 65-85 percent of feed levels until dosing
with NTA Na3 was terminated. Following initial
peaks, I4C levels in both effluents also decreased
and were generally 80-95 percent of feed concen-
tration for the remainder of the dosing period.
NTA and 14C first appeared in the effluent
from the saturated clay-loam column on the 7th
day of operation, attained relatively low peaks on
the 14th day. and then declined to minima on
about the 29th day (Figure 9). This decline was
attributed to aerobic degradation of NTA resulting
from the presence of air in the capillary fringe of
the column and possibly to the entrapment of air
pockets in soil interstices throughout the column.
After about the 30th day of operation, the saturat-
ed clay-loam column began performing in a manner
similar to the other saturated columns, probably
both as a result of intentional flooding of the
capillary fringe of the column on the 29th day and
depletion of oxygen in trapped interstitial air
pockets.
The fact that NTA Na., and 14C effluent con-
centrations were less than feed levels and 14C
effluent levels were equivalent to 2-10 mg/1 more
NTA Na3 than actually appeared in column efflu-
ents during most of the operating period for both
the saturated sand and loam columns and for the
clav-loam column after the 30th day indicate that
— 600-
e
JO 40 50
Days of Operation
Fig. 9. NTA, 14C, and metals in effluent from saturated
clay-loam column.
some degradation of NTA was occurring within
these columns. It is not evident, however, if this
degradation was truly anaerobic in nature, or if it
was at least partially aerobic degradation which
occurred in the capillary fringe regions of the col-
umns and which was arrested by lack of oxygen as
the feed solutions infiltrated deeper into the
columns.
Analysis of effluents from the saturated col-
umns for 14CO2 revealed that a major portion of
the 14C present in form other than NTA was
incorporated in CO2. Very small quantities of at
least one organic degradation product of NTA
were shown to be present in these effluents by
thin-layer chromatography and radioautography,
but the extremely low levels of the substance
prevented its identification.
The data obtained in these studies with satu-
rated soil columns show that NTA infiltrating
through saturated soil systems, such as flooded
septic tank percolation fields or under waste water
lagoons, will likely undergo at most only slow
degradation, and hence high proportions will prob-
ably reach ground water essential'}' unchanged.
Some NTA degradation products could possibly be
produced in saturated soils, but the quantities
entering ground water would likely be extremely
small.
As indicated in Figures 5-9, there were gener-
205
-------
ally good correlations between concentrations of
NTA Na3 and of iron, zinc, nickel, cobalt (although
the concentration of the latter element was never
very high), and possibly manganese in effluents
from various soil columns. The decreases in metals
concentrations in the saturated sand and loam
column effluents which accompanied decreases in
NTA Na3 concentrations following .termination of
NTA Na3 dosing on the 58th day of operation
appear particularly significant. Observation of the
effects of termination of NTA dosing on metals
concentrations in the effluent from the saturated
clay-loam column was not possible because clogging
and resulting poor flow performance precluded the
collection of further meaningful data from this col-
umn after about the 60th day. However, the
minima in effluent metals concentrations corres-
ponding to the minimum in NTA Na3 concentra-
tion occurring on the 29th day of operation pro-
vides significant additional information concerning
the effect of infiltrating NTA on the metals in the
saturated clay-loam soil.
Reasonable caution must be exercised in inter-
preting these metals data because of the lack of
comparison data from control columns. Neverthe-
less, the results of these experiments indicate
-strongly that NTA which infiltrates through over-
lying soil without being degraded is likely to solu-
bilize and transport into .ground water metals
native to the soils.
Studies Employing Sand Enriched with Metals
In order to further investigate the possible
transport of metals into ground water by NTA,
additional soil column studies were conducted
employing columns prepared from Konavva loamy
fine sand enriched with lead, zinc, chromium,
cadmium, and mercury.
Six soil columns 3.75 inches in diameter and
approximately 39 inches in depth were used. Two
were prepared from sand enriched with the follow-
ing natural ores: galena (PbS); sphalerite (ZnS);
chromite (Fe(CrO2)2); greenockite (CdS); and cin-
nabar (HgS). The other 4 columns were packed
from sand enriched with a synthetic sludge pre-
pared by alkali precipitation of lead, cadmium,
chromium, and zinc from a solution of their
soluble salts, with subsequent drying and grinding
of the precipitated sludge. Mercuric sulfide (cin-
nabar) was also added to the sludge-enriched sand
as a source of mercury. The individual columns
contained 5 g of each of the 5 metals, except that
only 995 mg of chromium was present in each of
the. 2 sand-metal ores columns because the chro-
mite ore contained only very low levels of this
element.
Two of the columns containing synthetic
sludge were operated under unsaturated, or aerobic,
conditions, while the other pair of sludge-contain-
ing columns and the 2 columns containing the ores
were operated under saturated, or essentially anaer-
obic, conditions.
The columns were dosed daily at a hydraulic
loading of 2 gal/ft2 (580 ml/day for each column).
One column of each pair was dosed with 67 mg/1
of 14C labeled NTA Na3 in distilled water (specific
activity 920 pCi/ml), while the 2nd column of the
pair served as a control and was dosed with
distilled water only. Starting with the 56th and
53rd day of operation, respectively, for the col-
umns dosed with NTA and the control columns,
sufficient Sego to impart a BOD of 50 mg/1 was
added to the daily feed solutions. The columns
were operated for a total of 92 days.
Effluents from columns dosed with NTA Na,
were analyzed for NTA Na3 and for radioactive
carbon as in the initial soil column studies. Iron,
manganese, lead, zinc, chromium, and cadmium
were determined in effluents from all 6 columns
by atomic absorption spectrophotometry, while
mercury was determined by the flameless atomic
absorption procedure (Federal Water Quality Ad-
ministration, 1970). Data obtained for the columns
dosed with NTA are presented in Figures 10-12.
Days of Operation
Fiq. 10. NTA, 14C, and metals in effluent from unsaturated
sand-metals sludge column.
206
-------
216
192
166
96O
84O
36O
240-
1 20-
Day s of Operation
Fig. 11. NTA, 14C, and metals in effluent from saturated
sand-metals sludge column.
IOSO
960
840
720
60O-
< 4SQ-
u~
a
— 360-
o
2 240-
120-
-FeedLevtl NTANc3 & C
.0
1-30 !
20
10
I to 20 30 40 50 60 70 60 90
Days of Operation
Fig. 12. NTA, 14C, and metals in effluent from saturated
sand-metal ores column.
NTA first appeared in the effluents from the
unsaturated and saturated columns of sand en-
riched with metals sludge on the 19th and 22nd
day of operation, respectively (Figures 10 and 11).
NTA concentration in the unsaturated column
effluent attained a maximum on the 39th day, and
then declined to become relatively stable at about
25 percent of feed level after the 70th day. In the
saturated column effluent NTA concentration
reached a maximum on the 57th day and then
slowly declined until termination of the experi-
ment. NTA first appeared in the effluent from the
saturated column of sand enriched with metal ores
on the 3rd day of operation, attained a concentra-
tion near the feed level on the 7th day, and re-
mained near feed level for the remaining 85 days of
the study (Figure 12).
Comparison of these data with similar data
obtained from the unsaturated and saturated sand
columns in the initial soil column studies (Figures
6 and 7) reveals that the movement of NTA
through sand enriched with metals sludge was very
much slower than through sand alone, while NTA
movement through sand enriched with metal ores
was little different than movement ot this com-
pound through sand alone. Obviously, the metal
hydroxides which principally constituted the met-
als sludge exerted some retarding effect on infil-
trating NTA not manifested by the metal ores,
which were mostly sulfides.
As Figure 10 shows, only about 75 percent of
infiltrating NTA was degraded in the unsaturated
sand-metals sludge column, while NTA was com-
pletely degraded, after a short acclimation period,
during infiltration through the unsaturated column
containing only sand in the initial soil column
studies (Figure 6). This effect most likely was due
to toxic effects of the heavy metals in the sludge
which resulted in partial inhibition of microbial
activity in the sand-metals sludge column.
The total quantities of metals eluted from the
columns dosed with NTA were in every case many-
fold greater than the quantities eluted from the
corresponding control columns receiving no NTA.
As shown by Figures 10 and 11, cadmium
levels were very high in effluents from both the un-
saturated and saturated sand-metals sludge col-
umns, attaining maxima of 14 mg/1 and 36 mg/1,
respectively, at the same time that peak NTA con-
centrations occurred. Iron and zinc were also pres-
ent in the effluent from the unsatu-rated column,
and high levels of iron, which had not been added
to the metals sludge, appeared intermittently in the
saturated column effluent. In addition, lesser quan-
tities of zinc, chromium, lead, and mercury oc-
curred in the latter effluent during the period that
207
-------
NTA was present, with peak concentrations gener-
ally appearing in synchrony with iron peaks. As
with the saturated sand-metals sludge column, iron
was intermittently present in high concentrations
in the effluent from the saturated sand-metal ores
column (Figure 12), together with lesser quantities
of zinc, chromium, cadmium, and mercury.
Throughout the period of operation, concen-
trations of the metals mentioned above were either
very small or below detectable levels in effluents
from the control columns.
Solubilization and transport of metals from
the soil by NTA appears to be the only explanation
for the significantly greater quantities of metals
eluted from the experimental columns than from
the control columns. The experimental and control
column pairs were prepared from identical quanti-
ties of the same enriched soils and were operated
by identical procedures except for the addition of
NTA to the feed for the experimental columns.
There were essentially no differences in pH values
and redox potentials in effluents from experimental
and control columns.
The data obtained in these experiments leave
little doubt that infiltration of water containing
NTA through saturated soils containing heavy
metals could result in solubilization and subsequent
transport of such metals into ground waters. These
studies also indicate that infiltration of water con-
taining NTA through unsaturated soils containing
high levels of heavy metals could result in both
NTA and metals entering the underlying ground
water because of metals toxicity and the resulting
inhibition of microbial degradation of NTA. The
extent and nature of metals solubilization and
transport by infiltrating NTA in a specific natural
situation will obviously depend on such variables as
the quantities of various metals in the soil, the
anionic species with which the metals are associ-
ated in the soil matrix, the concentration of NTA
in the infiltrating solution, and the relative stabili-
ties of the various metal-NTA complexes under
conditions prevailing in the particular soil system
of concern.
Over-all, the soil column studies described
above indicate some potential for pollution of
ground water by metals as a result of the use of
NTA in detergents. Accurate evaluation of the
actual extent and seriousness of this potential will
likely require thorough evaluation of the complex
factors affecting the formation of chelates by
NTA and metals in soils, including metals native to
the soils and those deposited by waste disposal.
SIMULATED AQUIFER STUDIES
In order to investigate the possible degrada-
Fig. 13. Details of simulated aquifer design.
tion of NTA in the essentially anaerobic ground-
water environment, model aquifers simulating as
nearly as possible conditions prevailing in a natural
aquifer were constructed in the laboratory. Figure
13 shows details of the simulated aquifer design.
Each laboratory aquifer was constructed from
a 4 1 aspirator bottle containing 3 1 of natural
aquifer sand. A 6 mm O.D. borosilicate glass tube
with perforations placed in a spiral arrangement
below the surface of the sand served as a well
shaft. This tube was packed loosely with glass wool
and was topped with a W-inch Swagelok Zytel tee
"well head." The side arm of this tee was con-
nected to a closed loop of Tygon tubing which
passed through a peristaltic pump and back to the
aquifer unit. This system permitted water to be
pumped from the saturated depths of the aquifer
sand through the well head and returned via the
closed tubing system to the aquifer unit. The upper
arm of the well head tee was sealed with a Teflon-
lined rubber septum through which the pumped
stream could be sampled. Ports for evacuation,
gassing, venting, and gas sampling were also pro-
vided.
Natural aquifer sand for construction of the
simulated aquifers was obtained near Byars, Okla-
homa, from a shallow aquifer underlying the flood-
plain of the South Canadian River. Aseptic pro-
cedures were employed to the extent possible in
collection of the sand and in construction of simu-
lated aquifers in order that the microbial popula-
tion of the models might approach that of the
natural aquifer. Three simulated aquifers were con-
structed, with one being sterilized by autoclaving
208
-------
after loading of the sand to serve as a control.
Initial charging of the simulated aquifers was
achieved by first removing most of the water native
to the aquifer sand by application of vacuum at the
bottom outlets of the aspirator bottles and then
allowing sterile solutions of NTA Na3 in distilled
water to flow into the evacuated units. The NTA in
the feed solutions for the sterile control aquifer
and one of the other units, designated Simulated
Aquifer Number 2, contained carbon-14, while the
NTA in the feed for the third unit, designated
Simulated Aquifer Number 1, contained no radio-
active isotope. Conditions of very low oxygen
tension were created within each aquifer unit by
twice thoroughly evacuating and refilling with
nitrogen gas.
The simulated aquifers were operated in a
darkened room at 20° C for 265 days. For the final
122 days they were operated under a blanket of
nitrogen to further preclude the possibility of
oxygen entering the units. The aquifers were re-
charged with NTA after 52, 143, and 209 days of
operation by aseptic addition of small volumes of
relatively concentrated sterile NTA Na3 solutions
through the tops of the units. Because the volumes
of water in the aquifers and the quantities of
NTA Na3 sorbed on aquifer sand could only be
estimated, the concentrations of NTA Na3 actually
present in the aquifer waters immediately after the
initial charging and subsequent rechargings of these
units varied from 30-55 mg/1. Sufficient Sego to
impart a BOD of 60-90 mg/1 to the water in each
aquifer was included in the third recharge in order
that the effect of an extraneous carbon source on
NTA degradation might be observed.
The aquifer units were pumped occasionally
for a few hours to simulate movement of ground
water and to maintain as much uniformity as pos-
sible within the units, particularly after recharging.
Units were always pumped for a short period im-
mediately before sampling in order to obtain repre-
sentative samples from the depths of the aquifers.
Samples were obtained at 3-7 day intervals by with-
drawing required quantities of liquid through the
well head septums by means of sterile syringes
while the units were being pumped. These samples
were analyzed for NTA Na3 and for 14C as previ-
ously described. Selected samples were also sub-
jected to thin-layer chromatography and radio-
autography, and the composition of the gas in
each unit was determined by gas chromatography
each time a liquid sample was obtained.
As shown by Figure 14, significant microbial
degradation of NTA occurred in the experimental
simulated aquifers during the initial 52-day period
of operation. Beginning concentrations of 30-32
Initial Charge
Z 20
55 60 65 70 75 80 65 90 95 100
Days of Operat ion
Fig. 14. Degradation of NTA in simulated aquifers; initial
charge and first recharge.
mg NTA Na3/l in the aqueous phases of both Aqui-
fer Number 2, which contained 14C-NTA, and
Aquifer Number 1, which contained only non-
labeled NTA, decreased to essentially zero during
this period, while NTA Na3 in the sterile control
aquifer decreased only from approximately 33 mg/1
to 29 mg/1. In the periods following the first and
second rechargings of the simulated aquifers, simi-
lar degradation of NTA occurred in the experi-
mental units, with the over-all rates being some-
what higher than in the initial period of operation
(Figures 14 and 15).
Gas samples taken from the aquifer systems
were found to contain low levels (usually less than
0.2 percent) of oxygen at various times during the
initial period of operation, but essentially no oxy-
gen was noted in such samples at any time after
the first recharging. Gas analyses also revealed the
production of methane and low levels of carbon
dioxide in both experimental aquifers, with no
production of either gas in the control aquifer.
The methane produced in Simulated Aquifer Num-
ber 2, which contained 14C-NTA, was found to be
radioactive, thus confirming it as a degradation
product of NTA. This would appear to show be-
yond reasonable doubt that the degradation of
NTA in the simulated aquifers was truly anaerobic.
209
-------
Stcond Rtchorge
NT*—Aflu.lw
210 #5 22Q 2 25 250 235 MO 2*5250
7*5-
Oojft of Optrotion
Fig. 15. Degradation of NTA in simulated aquifers; second
and third recharges.
Thin-layer chromatography and radioautogra-
phy gave limited evidence for the presence in
Simulated Aquifer Number 2 during maximum
degradation of NTA of an intermediate organic
degradation product with chromatographic proper-
ties very similar to NTA. Time limitations pre-
cluded extensive study of this substance, and the
possibility exists that it was a chromatographic
anomaly, produced by the effect on NTA of salts or
other substances in the sample solutions.
A large proportion of the 14C introduced into
Aquifer Number 2 with each NTA charge remained
in the aqueous phase of the aquifer after essentially
all of the NTA had disappeared (Figures 14 and
15). This 14C was necessarily a component of
degradation products of NTA, but hardly any of it
could be accounted for on radioautograms of aqui-
fer samples obtained after NTA had disappeared
from the units. Although a portion of this 14C was
undoubtedly present in the form of carbon dioxide
and methane, it appears that other volatile degrada-
tion products, which would have been lost during
sampling and chromatography and hence would
not have been detected by radioautography, may
have been present in the aqueous phase of the
aquifer after all of the NTA had been degraded.
Obviously, the pathways, intermediates, and final
products of degradation of NTA under anaerobic
conditions need further elucidation.
210
Degradation of NTA proceeded at slightly re-
duced rates in both of the experimental aquifers
after the third recharging, which included Sego as
a carbon source in addition to NTA (Figure 15).
The magnitude of these rate decreases were relative-
ly small, however, and there is no certainty that
they were attributable to the extraneous carbon
source since products of microbial metabolism
which had accumulated in the aquifers during the
210 days of operation prior to the third recharge
could also have caused some decrease in NTA
degradation. It should be noted that addition of
an extraneous carbon source to an aquifer with the
initial charge of NTA, before the microbes present
in the aquifer have adapted to degrade NTA, could
produce a quite different effect than observed here.
Over-all, the data obtained in the simulated
aquifer studies indicate that NTA entering an
essentially anaerobic ground-water environment
will likely undergo degradation, with methane,
carbon dioxide, and possibly other volatile com-
pounds being the probable final products of such
degradation. This phenomenon could be quite
important in retarding the development of high
levels of NTA in aquifers receiving waste waters
which contain this substance and in decontamina-
tion of aquifers which might become polluted by
NTA. It should be noted, however, that the sand
employed for construction of the simulated aqui-
fers in these studies was obtained from a very shal-
low natural aquifer which probably contained a
numerous and active population of anaerobic
microorganisms because of periodic infusion with
water of relatively high organic content. It is
probable that anaerobic microbial populations in
many natural aquifers, particularly deep aquifers,
would be much less numerous and active; hence,
the degradation of NTA, or at least the initiation
of such degradation, would likely occur much
more slowly in such aquifers than was observed in
simulated aquifers during these studies.
CONCLUSIONS
The investigations described above permit the
following conclusions concerning the potential
impact of NTA on ground water.
1. Sorption of NTA by some types of soils
may considerably slow the initial movement of
this compound into and through ground waters.
However, sorption of NTA by soils does not appear
to be sufficient to prevent or appreciably decrease
the pollution of ground waters by this compound
over the course of its long-term usage as a detergent
builder.
2. NTA infiltrating through unsaturated soils,
as in properly operating septic tank percolation
-------
fields, will probably undergo rapid and complete
degradation. Only inorganic nitrogen compounds
and carbonates are likely to enter ground water as
the result of such degradation. Introduction of
these substances into ground waters is not desirable,
but the quantities introduced as a result of NTA
use in detergents are not likely to be sufficient to
create critical pollution problems.
3. The degradation of NTA infiltrating
through unsaturated soils which contain high levels
of heavy metals, such as those receiving wastes
from metals plating operations, may be partially
inhibited as a result of toxicity of the metals to
soil microorganisms; hence, some NTA may enter
ground water under such circumstances.
4. NTA infiltrating through saturated soil
systems, as in flooded septic tank percolation fields
and under some waste water lagoons, will likely
undergo only limited degradation; hence, a signifi-
cant portion will enter underlying ground water,
possibly accompanied by small quantities of
organic degradation products of NTA.
5. NTA which reaches the water table will
likely undergo slow degradation in the essentially
anaerobic ground-water environment. The final
products of such degradation will probably include
carbon dioxide and methane, and possibly other
organic compounds of low molecular weight and
relatively high volatility. Unknown intermediate
products of NTA degradation may also be present
in an aquifer when NTA is being actively degraded.
6. NTA that infiltrates through overlying soil
into ground water without being degraded may
solubilize and transport into the ground water
such metals as iron, zinc, chromium, lead, cadmi-
um, and mercury which may be present in the
soil. Situations where NTA might infiltrate through
soils receiving wastes containing high levels of
toxic heavy metals, such as metal plating wastes,
would appear to entail considerable potential for
metals contamination of underlying ground waters.
However, comprehensive evaluation of the poten-
tial threat to ground-water quality posed by
solubilization and transport of metals in soils by
infiltrating NTA will require further elucidation of
the factors controlling formation of NTA-metals
chelates in soils.
7. Even in the most favorable circumstances,
use of NTA as a detergent builder is likely to result
in some increases in nitrogen and probably carbon
in ground waters. Phosphates in waste waters do
not readily move into or through ground waters
because of strong sorption in soils. Hence, in
comparison to phosphates the use of NTA in deter-
gents would likely result in at least a limited ad-
verse impact on ground water.
ACKNOWLEDGEMENTS
The authors are indebted to Bobby Newport,
Physical Science Technician, for his significant
contribution in construction and operation of the
experimental systems. The invaluable assistance of
Richard E. Thomas, Soil Scientist, of Linda Harmon,
Secretary, and of Jack W. Keeley, Chief, National
Ground Water Research Program, is also gratefully
acknowledged.
REFERENCES
Federal Water Pollution Control Administration. 1969.
FWPCA methods for chemical analysis of water and
wastes. Analytical Quality Control Laboratory, Cin-
cinnati, Ohio.
Federal Water Quality Administration. 1970. FWQA pro-
visional method for mercury (flameless AA proce-
dure). Analytical Quality Control Laboratory, Cincin-
nati, Ohio.
Thompson, J.E. and J. R. Duthie. 1968.The biodegradability
and treatability of NTA. Journal WPCF. v. 40, pp.
306-319.
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