Historical Knowledge of
Ground Water
© 2001, C. W. Fetter, Jr.
This paper is my attempt to provide a historical background for the science of hydrogeology. I have tried to keep it reasonably short so that busy students might still find the time to read it. I have also included short excerpts from some of the articles so that the reader might taste the flavor of the writing. Most of the excerpts are translations so that we are dependent upon the translator to give us a taste of the original language.
I am sure that others might offer
some different views of which articles are important enough to be included in a
historical context. Moreover, I am not familiar with every article on
hydrogeology or ground water that has ever been published. In order to limit
the scope and length of the paper, I have not included the topic of ground
water geochemistry. I would like to
thank Dr. Stan Davis of the University of Arizona for his helpful comments on
the manuscript.
Ancient World
In prehistoric times springs
doubtless served as an important source of water for both nomadic and agrarian
peoples. Today we know that springs are fed by ground water, which is in turn
fed by infiltrating precipitation. Ancient
peoples did not have this knowledge. However, they eventually found that wells
could be dug to tap ground water in places were springs did not exist, or where
springs and streams were not perennial.
One of the oldest surviving examples
of ground water utilization is the qanat or kanat. This was an excavated tunnel
that was more or less horizontal but extended into the side of a hill so that
it eventually tapped into the water table. Access to the horizontal tunnel was
by means of a series of vertical shafts.
The allowed light to enter the shaft so that the diggers could see what
they were doing. The vertical shafts were about 180 feet apart. A series of
test wells were dug to locate the water bearing formations and then the tunnel
was constructed. The tunnel was sloped
slightly downhill so that the water drained from the wells into the tunnel and
hence toward the city where it was to be used.
Qanats were described as being
present in Armenia in the period 721-705 BC.
An ancient qanat system still exists south of Dizful in Iran. Some of these
ancient qanats were as deep as 400 feet below the surface and extended more
than 20 miles. The use of qanats for water supply was introduced into Egypt
about 500 BC. Even in modern times qanats have been used for water supply in
the Middle East, especially Iran. [i]
The use of ground water is described
in many places in the Bible. For example, Genesis describes how Abraham used
his knowledge of well digging to settle his people in the Judean hills of
Canaan.
“And Isaac digged again the wells of water which they had digged in the
days of Abraham, his father; for the
Philistines had stopped them after the death of Abraham: and he called their
names after the names by which his father had called them.
And Isaac’s servants digged in the valley, and found there a well of
springing water.” Genesis 26: 17-19.
The Bible also described the water
cycle in Ecclesiastes 1:7:
“All
streams run to the sea,
but the sea is not full;
to the place where the streams flow,
there they flow
again.”
In the ancient city of Athens in the
middle of the 6th Century BC could be found “public wells of great
depth, covered with stone slabs, with small apertures, the necks of which are
well furrowed by the ropes which for centuries have drawn the dripping buckets
form the cool depths.” [ii]
The first recorded theories on the
elements of the hydrologic cycle were postulated by the Greeks, who regarded
water to be one of the four elements (along with earth, wind and fire) from
which all was constructed. Their main
concern was about the source of water flowing in rivers.
“Rivers depend for their existence on the rains and on the water within
the earth, as the earth is hollow and has water in its cavities”
Anaxagoras of Clazomenae
(500-428 BC)
“The land had great depth of soil and gathered the water into itself and
stored it up into the soil . . . as though it were a natural water jar; it drew
down into the natural hollow the water which it had absorbed from the high
ground and so afforded in all districts of the country liberal sources of
springs and rivers.”
Critias, Plato (427-346 BC)
“Just as above the earth, small drops form and these join others, till
finally water descends in a body of rain, so too we must suppose that in the
earth the water at first trickles together little by little, an that the
sources of rivers drip, as it were , out of the earth and then unite.”
Meterologicia, Aristotle (384-322 BC)
Greece is a land of limestone
terrain and the Greek philosophers were well award of underground caves and
caverns. They imagined that in addition
to rains, rivers were fed from some sort of subterranean body of fresh
water. Aristotle believed that the
subterranean sea had to have a supply of new water, and he attributed this to
conversion of air to water within the earth, just as cold changes air to water
above the earth.
“the air surrounding the earth is turned into water by the cold of the
heavens and falls and rain . . . the air which penetrates and passes the crust
of the earth also becomes transformed into water owing to the cold which it
encounters there. The water coming from
the earth unites with rain water to produce rivers. The rainfall alone is quite
insufficient to supply the rivers of the world with water.”
Meterologicia, Aristotle (384-322 BC)
The Greek philosophers had the
mistaken impression that rainfall could not account for the amount of water in
the ground, and hence had to concoct an improbable hypothesis of underground condensation.
A second improbably hypothesis was postulated that this underground chamber was
fed by seawater which somehow became purified of its salt. Both hypotheses fail
to provide a believable mechanism to raise the water from the depths of these
underground chambers to the level of rivers in mountains, which are far above
sea level.
This misunderstanding persisted
through Roman times. Seneca (4 BC - 65 AD) wrote about the origins of rivers.
He did not believe that rainfall could supply the water in rivers. He noted
that in his vineyard even the heaviest rainfall would not penetrate more than
10 feet into the ground. He attributed the presence of ground water to one or
more of three possible sources: (i) the earth itself contains a lot of moisture
that is continually being forced out (ii) air within the earth is continually
being converted into water by the forces of darkness and cold (iii) earth is
simply being converted to water[iii].
(Remember that the ancient philosophers believed that earth, air, and water
were all primary elements.)
Vitruvius wrote a treatise on
architecture, De architectura libri
decem, in about 27 to 17 BC, which had some practical suggestions for
finding ground water. He included a table describing the amount and taste of
water which might be found in different soil types. He also recognized that
rivers and springs were the result of melting snow in the mountains percolating
into the soil and then coming to the surface in the valleys below the mountains[iv].
While Vitruvius was correct, his theory was not widely adopted.
Middle Ages
When Roman civilization faded, there
was literally no original thinking about natural phenomena for about the next
1500 years. Even the great Leonardo da
Vinci (1452 - 1519) maintained the concept of a hydrologic cycle in which
underground veins of water rose from the sea to the mountains, where they
issued forth as rivers. During this underground passage the salt was filtered
out. This concept was identical to some of the concepts put forth by Greeks
such as Plato[v].
The first person to provide a
correct written explanation of the origin of rivers and springs and the
hydrologic cycle was a Frenchman, Bernard Palissy (1510? - 1590):
“ rain water that falls in the winter goes up in summer, to come again
in winter. . . And when the winds push these vapors the waters fall on all
parts of the land, and when it pleases God that these clouds (which are nothing
more than a mass of water) should dissolve, these vapors are turned to into
rain that falls on the ground.”
“And these waters, falling on these mountains through the ground and
cracks, always descend and do not stop until they find some region blocked by
stones or rock very close set and condensed. And they rest on such a bottom and
having found some channel or other opening, they flow out as fountains or
brooks or rivers according to the size of the opening and receptacles…”
Discourse admirables,
Palissy ,
1580
Palissy also correctly deduced the
origin of artesian pressure in wells and the fact that wells near rivers could
be connected to the rivers through “underground veins”. Unfortunately Palissy
wrote in French, rather than Latin, which was the accepted scientific language
of the day. Hence, his work was not widely distributed and the incorrect
hydrologic concepts of the Greek and Roman philosophers continued to persist.
Some of the famous men of the 17th
Century who made important contributions in other sciences continued to advance
variations of Greek and Roman theories about the origin of rivers, among them
Johannes Kepler (1571-1630) and René Decartes (1596-1650).
Beginnings of Qualitative
Hydrogeology
During the 17th Century
the first quantitative measurements of hydrologic phenomena were made. Pierre Perrault (1608-1680) made a study of
the upper reaches of the Seine River. He measured the average annual rainfall
over a small part of the upper the Seine basin well as the annual discharge of
the river from that catchment. He found that rainfall was six times the amount
that flowed in the Seine, thus proving that precipitation was more than enough
to supply the water in the Seine and:
“to cause this River to flow for one year, from its source to the place
designated, and which must serve also to supply all of the losses, such as the
feeding of trees, plants, grasses, evaporation….”
De l’origine des fontaines, Pierre
Perrault, 1674
However, he
thought that the springs were fed by the rivers and that in general there was
little infiltration of rainwater into the ground.[vi] In a related subject he demonstrated by
experimentation that capillary rise of water was less than 1 meter in sand and
could not flow to create a body of free water above the water table[vii].
Further investigation of the
rainfall - runoff cycle was made in France by Edmé Mariotte (1620 - 1684). He
confirmed Perrault’s work on the Seine using a much larger catchment area by
measuring the flow of the Seine at Paris. He determined that precipitation was
sufficient to supply both rivers and springs within the basin. He also believed
that springs were fed by precipitation, and not by rivers[viii].
He also said that infiltrating precipitation penetrated the pores of the earth
and accumulated in wells. He studied infiltration of rainwater into the
basement of the Paris Observatory and observed that more water came into the
basement after heavy rains. He showed that the flow of springs increases in
rainy weather and diminishes in times drought and that springs with a more
consistent flow are fed by larger underground reservoirs[ix].
Edmond Halley (1656 - 1742) the
noted English astronomer made an important contribution to hydrology by
studying evaporation. He concluded that there was sufficient water evaporating
from the ocean to supply all of the rivers and springs on earth[x].
Although by the end of the 17th
Century several writers had clearly established that springs and rivers were
the result of precipitation, others tried to prove them wrong and still connect
some sort of underground passageway from the sea to the mountaintops. One new
theory that was advanced was the capillary theory, which was postulated by Rev.
W. Derham in 1713[xi]. He proposed that water rose from the level
of the sea to the tops of mountains by capillary action, a clear impossibility
based on Perrault’s experiments.
In the 18th Century
progress was made in utilizing the correct knowledge of the hydrologic cycle to
develop ground water supplies. In England William Smith found that he could
increase the flow of a spring by deepening it. He also constructed a pipeline
from the spring to the city reservoir so that the springtime flow of the spring
could be saved for use in the summer and fall when the spring flow was much
less[xii].
Beginnings of Quantitative
Hydrogeology
It was in the 19th
Century that ground water hydrology begun as a quantitative science. Henry Darcy (1803 - 1858), a French civil
engineer, was the first person to determine the mathematical law that governs
the flow of ground water, which is now known as Darcy’s Law. It was based on experiments
that he made on the flow of water through sand filters. He published it in an
appendix to his report on a new water supply for the City of Dijon, France[xiii].
Darcy determined that the flow of water through a sand filter was a function of
the pressure head across the filter, the cross sectional area of the filter and
the nature of the sand, i.e., coarse or fine.
“I approach now an account of the experiments that I carried out at
Dijon together with Engineer Charles Ritter, to determine the laws of flow of
water through sand. Each experiment
consisted of establishing a specified pressure in the upper chamber of the
column by adjustment of the inflow tap; then when it was established by means
of two observations that the flow had become essentially uniform, the outflow
from the filter during a certain time was noted, and the mean outflow per
minute was calculated from it.”
Les fontaines publiques de la ville de Dijon, 1856, Henry Darcy
Just seven years later A. J. E. J.
Dupuit (1804 - 1866) used Darcy’s Law to derive an equation for the flow of
water to a well.[xiv] In 1870 the German, Adolph Thiem modified
Dupuit’s formula so that one could calculate the hydraulic properties of an
aquifer by pumping a well and observing the resulting decline in the water
table in nearby wells[xv]. Further advances in the mathematical
foundations of ground water flow were made in the 19th Century by
the Austrian, Philip Forchheimer[xvi]
and the American, Charles Slichter[xvii].
The late 19th Century also
saw the development of a more comprehensive understanding of the relationship
of ground water to the geological formations in which it occurs. An American,
T. C. Chamberlin, who was a famous geologist, a professor at the University of
Wisconsin and an employee of the United States Geological Survey, published
“The Requisite and Qualifying Conditions of Artesian Wells” in 1885[xviii].
This was the first hydrogeologic report published by the United States
Geological Survey. It provided a theoretical basis for the scientific study of
the occurrence of ground water and thus prompted an explosion of activity in
the evaluation of ground water resources in the United States. However, not all
of Chamberlin’s concepts were correct. For example, it is not necessary to have
confining beds below an aquifer, and it is possible to have a flowing well in
the absence of structural controls.
“There are two general methods by which water finds its way through the
strata: in the one – the rocks being close-textured – the water passes through
fissures formed by fracture, or tubular channels formed by solution; in the
other – the rock being open-textured – the water seeps through the pores,
permeating the whole bed.”
Requisite and
Qualifying Conditions of Artesian Wells, T. C.
Chamberlin, 1885.
Chamberlin’s seminal work was followed by a paper by
Franklin H. King, another professor at the University of Wisconsin and U.S.
Geological Survey employee who wrote “ Principles and Conditions of the Movements
of Ground Water” in 1899[xix].
King introduced a number of important concepts in this paper including the
movement of ground water due to gravity. He showed the configuration of the
water table through the use of water-level contour maps and indicated the
horizontal direction of ground water flow by the use of arrows drawn at right
angles to the contour lines. This was the first ground-water flow map. His
report also contains a cross section of a stream valley with ground water flow
lines originating beneath upland areas and converging on the stream valley to
discharge into the stream. He was the first to observe that in humid areas the
water table was a subdued reflection of the surface topography.
“The contours of the ground-water level show that this surface presents
the features of the hills and valleys approximately conformable with the relief
forms of the surface above, the water being low where the surface of the ground
is low, and high where the surface of the ground is high.”
Principles and
conditions of the movements of ground water, 1899, Franklin Hiram King
Modern Era of Hydrogeology
Quantitative
hydrogeology
Scientific hydrogeology received a basic foundation
in the 19th Century, and came of age in the 20th. Further
progress was made in developing our understanding of the mathematical basis of
ground water movement. Slichter wrote
two more important papers in 1902[xx]
and 1905[xxi].
C. V. Theis of the U. S. Geological Survey published
two papers of fundamental importance, one in 1935[xxii]
and one in 1938[xxiii]. In his 1935 paper Theis published an
equation to describe the decline of the piezometric (potentiometric) surface in
a fully confined aquifer due to the withdrawal of water via a well. This paper
forms the basis for all other papers that quantify the flow of water to wells
in confined or semiconfined aquifers. In his 1938 paper he describes the
formation of a regional cone of depression and its impact on the dynamic
equilibrium of the aquifer.
“In nature the hydraulic system in an aquifer is in balance; the
discharge being equal to the recharge and the water table or other piezometric
surface is more or less fixed in position. Discharge by wells is a new
discharge superimposed on the previous system. Before a new equilibrium can be
established water levels must fall throughout the aquifer to an extent
sufficient to reduce the natural discharge or increase the recharge by an
amount equal to the amount discharged by the well. Until this new equilibrium is established water must be withdrawn
from storage in the aquifer and conversely the new equilibrium cannot be
established until an amount of water is withdrawn from the well sufficient to
depress the piezometric surface enough to change the recharge or natural
discharge the proper amount. The depression of the piezometric surface is
called the cone of depression.”
The significance and nature of the cone of depression in ground water bodies, 1938, Charles V. Theis
In 1940 M. King Hubbert of Shell Oil Company
published “The Theory of Ground Water Motion”[xxiv].
Hubbert placed a theoretical foundation under the Darcy equation and introduced
the force potential, which combines the pressure and gravitational potential.
Through this work he demonstrated that Darcy’s law for ground water flow is
analogous to Ohm’s law for the flow of electricity. He also demonstrated that
flowing wells could be the result of the potential field even in a homogeneous,
isotropic aquifer.
Also in 1940 C. E. Jacob devised a graphical method
of interpreting aquifer test data for a pumping well in a fully confined
aquifer based on the Theis equation[xxv].
In 1955 M. S. Hantush and C. E. Jacob solved the problem of quantifying
nonsteady flow to a well in a leaky or semiconfined aquifer[xxvi]. Hantush later published a number of papers
describing flow in leaky aquifers[xxvii]
[xxviii].
Papers by De Josselin De Jong in 1958[xxix]
and Ogata and Banks in 1961[xxx]
in which longitudinal and transverse dispersion and diffusion were discussed
form the basis for later work on mass transport in porous media.
The
papers listed above firmly established the fundamentals of modern knowledge of
quantitative ground water movement.
Ground
Water Exploration
The first part of the 20th
Century also saw a rapid expansion of the exploration for ground water supplies,
especially by the United States Geological Survey (USGS). Starting about 1900
hydrogeologists from the USGS fanned out across the United States. Early photos
show these pioneering geologists riding horses and buggies across the prairies
and deserts of the Western United States. Some examples of their early work
includes studies of N. H. Darton in South Dakota and Wyoming (1901[xxxi],
1905[xxxii]),
M. L. Fuller in the Eastern United States 1904[xxxiii]),
W. Lindgren in Hawaii (1903[xxxiv]),
W. T. Lee in Arizona (1904[xxxv],
1905[xxxvi]),
W. C. Mendenhall in California (1905[xxxvii])
and C. E. Siebenthal in Colorado (1910[xxxviii]).
O. E. Meizner, who was chief of the
Ground-Water Division of the USGS from 1912 to 1946, synthesized the results of
numerous regional studies of ground water to prepare Water Supply Paper 429, “The Occurrence of Ground Water in the United
States”, which was published in 1923[xxxix]. In this book he organized and integrated
knowledge from various regional reports into a coherent whole as well as
setting important principals for the occurrence of ground water. He also developed the ground-water
inventory methods that can be used to determine the amount of water passing
through a ground-water basin.
“The rocks that form the surface of the earth are in few places, if
anywhere, solid throughout. They contain numerous open spaces, called voids or
interstices, and these spaces are the receptacles that hold the water that is
found beneath the surface of the land and is recovered in part through springs
and wells. There are many kinds of rocks, and they differ greatly in the
number, size, shape and arrangement of their interstices and hence in their
properties as containers of water. The occurrence of water in the rocks of any
region is therefore determined by the character, distribution and structure of
the rocks it contains – that is by the geology of the region.”
The occurrence
of ground water in the United States, 1923, Oscar Edward Meinzer
Ground Water Contamination
Knowledge about ground water contamination developed approximately
parallel to knowledge about the occurrence and movement of ground water. One
reason for this is the fact that it wasn’t until the work of Louis Pasteur that
we knew that disease could be caused by microorganisms. As late as the Civil
War in the United States (1861-1865) the correlation between contaminated water
and disease was not widely known. More soldiers died of disease than bullets
and sabers in the Civil War.
In 1849 John Snow, a London
physician, wrote a paper that claimed that cholera was spread by a “poison”
from the excreta and vomit of cholera victims and that it could potentially be
spread by contaminated drinking water[xl].
A few years later he was able to show that the London cholera epidemic of 1854
was spread by ground water taken from a certain public well on Broad Street. He
stopped the epidemic by removing the pump handle.
In 1873 Austin Flint, an American
doctor, wrote an article in which he demonstrated that typhoid fever was
contracted by drinking contaminated ground water[xli].
A year later Edward Orton, the President of what is now Ohio State University,
wrote a remarkable paper that noted that ground water not only flowed from
place to place, but that as it flowed it could dissolve substances from the
soil, and if ground water flowed through human waste, it could pick up disease[xlii].
Industrial contamination was also known to be a potential ground water
contaminant in the last part of the 19th Century, as wastes from gas
works were known to have polluted nearby wells[xliii].
During the first decade of the 20th
Century the USGS also published several papers on ground water contamination
problems, including sewage disposal problems in limestone bedrock[xliv],
disposal of oily wastes from oil wells,[xlv]
, contamination of wells in sandy deposits [xlvi]
and another paper on sewage disposal in limestone aquifers[xlvii].
One of the major industries of the
first part of the 20th Century that caused pollution problems in
water was the manufacture of gas from coal. One reason for this was that the
wastes contained phenol, which has an objectionable taste when dissolved in
water.
In 1908 a
brewery in New Jersey sued the owners of an adjacent manufactured gas plant for
contaminating their well with tarry waste, which had been allowed to seep into
the ground[xlviii].
Ground water which had been contaminated with wastes
from manufactured gas plants were known to be capable of traveling considerable
distance through the ground.
“Another bad effect of gas house wastes which has here and there given
rise to more or less serious trouble is the pollution of the soil, which in
turn gives rise to gassy tastes in water wells and gassy odors in cellars. A
striking example of this occurred in Joliet, where one of the public water
supply wells was affected by a gassy taste that could be explained on no other
basis than contamination from a gas plant nearby. The writer had occasion some
years ago to observe a similar instance of the long travel of gassy wastes at
the town of Carthage, in Southern Ohio. Here the pollution was occasioned by
coal tar wastes used at a tar paper factory. These wastes were permitted to
flow into a pit at least 2000 feet from the affected wells.”
Disposal of Gas House Wastes, Paul Hanson, 1916[xlix]
During the 1920’s and 1930’s experimental
fieldwork was done on the travel of various contaminants through aquifers. C.
W. Stiles and H. C. Crohurst studied the movement of bacteria through aquifers[l].
A. F. Dappert studies the movement of a plume of contaminated ground water by
tracing the amount of dissolved chloride for a distance of 1500 feet[li]
and C. K. Calvert found that organic wastes dissolved in ground water traveled
500 feet in eight months[lii]. In 1941 a paper written by Burt Harmon noted
that there were many types of wastes that should be kept out of ground water to
avoid pollution and gave a few examples including:
“greasy wastes from tanneries, packing plants, woolen mills; oily wastes
from oil wells and refineries; soapy wastes from laundries; acid wastes from
chemical works and oil refineries; saline wastes from oil wells….
Contamination of Ground-Water
Resources, Burt
Harmon, 1941[liii]
In the United States industrial
production was greatly increased during World War II. At that time
environmental protection was not a priority. Problems of ground water
contamination were discovered soon after the War started. Two cases of ground water contamination by
dissolved heavy metals are noteworthy.
Both situations arose on Long Island, New York where the water table is
shallow, the aquifer is permeable and wastewater containing cadmium and
chromium from metal part plating were put into seepage ponds. Davids and Lieber
described chromium contamination in a 1951[liv]
paper and Lieber and Welsch addressed chromium contamination in a 1954[lv]
paper. These papers demonstrated that contaminated ground water could travel
many hundreds of feet through sand aquifers.
Textbooks
The general nature of the hydrologic cycle and the circulation of
ground water was a topic that was typically discussed in textbooks for general
courses in geology and physical geography written in the first part of the 20th
Century. A few examples are listed below:
Elements
of Geology by Joseph Le Conte, revised by Herman LeRoy Fairchild, 5th
Edition, 1915, D. Appleton and Company, New York.
A
Textbook of Geology, Part I, Physical Geology by Chester R. Longwell,
Adolph Knopf and Richard F. Flint, 2nd Edition, 1939, John Wiley
& Sons, Inc., New York.
Lessons
in Physical Geography by Charles Redway Dryer, 1916, American Book Company,
New York.
The
Elements of Geography by Rollin D. Salisbury, Harlan H. Barrows and Walter
S. Tower, 1913, Henry Holt and Company, New York.
More specialized textbooks also had
sections on ground water. William P. Mason of Renesselaer Polytechnic Institute
published a book, Water Supply, in
1896[lvi].
In this book he has two chapters devoted to ground water. In them he discusses
the source, occurrence and movement of ground water, and how to obtain ground
water via wells. He also discussed in some depth how ground water becomes
contaminated by sanitary waste and how this can be avoided.
In 1937 C. F. Tolman of Leland
Stanford Junior College published an entire book dedicated to only one subject,
Ground Water[lvii].
The comprehensive work is 593 pages long and has the following chapters:
Introduction
Resume of Elements of Ground-Water
Hydrology and Applications to Ground-Water Litigation
Brief Review of Rainfall, Runoff,
Evaporation and Transpiration
Hydrologic Properties of Water-Bearing
Materials, Except Soil
The Soil
Occurrence of Water and Forces
Acting in the Zone of Aeration
Influent Seepage Including Water
Spreading
Percolation, Ground-Water Turbulent
Flow and Permeability
The Water Table in Granular Pervious
Material
Ground Water in Fracture and
Solution Opening
Confined Water
Geological Classifications of
Artesian Aquifers
Wells
Oil Field Fluids
Springs
The Ground Water Inventory
Ground-Water Provinces of the United
States and Hawaiian Islands
Tolman’s book on ground water was so
complete and up to date in 1937 that another general textbook on ground water, Ground Water Hydrology, by David K.
Todd, also of Stanford University, was not published until 1959[lviii].
Since 1959 a large number of
textbooks on many aspects of hydrogeology have been published in the United
States. However, their contents are in many ways based on work done by the
pioneering hydrogeologists and engineers introduced in this brief paper.
[i] Tolman, C. F. 1937, Ground Water, McGraw Hill Book Company: New York. 593 p.
[ii] Butler, H. C., 1902, “The Story of Athens”, Century Croft Company, pp. 74-75 as cited in C. F. Tolman, 1937, Ground Water, McGraw Hill Book Company: New York. 593 p
[iii] Biswas, A. K. 1970, History of Hydrology North-Holland Publishing Company, Amsterdam, 336 p.
[iv] Biswas, A. K. 1970, History of Hydrology North-Holland Publishing Company, Amsterdam, 336 p.
[v] Biswas, A. K. 1970, History of Hydrology North-Holland Publishing Company, Amsterdam, 336 p.
[vi] Biswas, A. K. 1970, History of Hydrology North-Holland Publishing Company, Amsterdam, 336 p.
[vii] Davis, Stanley and Roger DeWeist, 1966, Hydrogeology, John Wiley and Sons: New York, 463 p.
[viii] Biswas, A. K. 1970, History of Hydrology North-Holland Publishing Company, Amsterdam, 336 p.
[ix] Tolman, C. F. 1937, Ground Water, McGraw Hill Book Company: New York. 593 p.
[x] Halley, Edmond, 1687, An estimate of the quantity of vapour raised out of the sea by the warmth of the sun. Philosophical Transactions of the Royal Society of London 16: 366-370.
[xi] Derham, W. 1713, Physico-theology. W. Innys, London.
[xii] Smith, William, 1827, On retaining water in the rocks for summer use. Philosophical Magazine, New Series I: 415.
[xiii] Darcy, Henry, 1856, Les fontaines publisues de la ville de Dijon. Victor Dalmont, Paris: 674 pp.
[xiv] Dupuit, A. J. E. J., 1863, Etudes theoriques et practiques sur le mouvement de eaux das les canaux decouverts et a travers les terrains permeables, 2nd ed.: Dunod, Paris, 304 pp.
[xv] Theim, Adolph, 1887, Verfahress fur Naturlicher Grundwassergeschwindegkiten: Polyt. Notizblatt, 42:229.
[xvi] Forchheimer, Philip, 1886, Uber die Ergebigkeit von Brunnen Anlagen und Sickerschlitzen. Zeitschrift des Architekten- und Ingenieur Vereins zu Hannover. 32:539-564.
[xvii] Slichter, Charles S., 1899, Theoretical investigation of the motion of ground water. U. S. Geological Survey Nineteenth Annual Report, Part 2:295-384.
[xviii] Chamberlin, T. C. 1885, The requisite and qualifying conditions of artesian wells, U. S. Geological Survey 5th Annual Report: 125-176.
[xix] King, Franklin H. 1899, Principles and conditions of the movements of ground water, U. S. Geological Survey 19th Annual Report, pt. 2:58-294.
[xx] Slichter, Charles S. 1902, The motions of underground waters, U. S. Geological Survey Water Supply Paper 67: 106 pp.
[xxi] Slichter, Charles S. 1905, Field measurements of the rate of movement of underground waters, U. S. Geological Survey Water Supply Paper 140: 106 pp.
[xxii] Theis, Charles V. 1935, The lowering of the piezometric surface and the rate and discharge of a well using ground water storage. Transactions of the American Geophysical Union 16:519-524.
[xxiii] Theis, Charles V. 1938, The significance and nature of the cone of depression in ground water bodies, Economic Geology 38:889-902.
[xxiv] Hubbert, M. King, 1940. The theory of ground water motion, Journal of Geology 48, no. 8:785-944.
[xxv] Jacob, C. E., 1940, The flow of water in an elastic artesian aquifer, Transactions, American Geophysical Union, 21:574-586.
[xxvi] Hantush, M. S. and C. E. Jacob, 1955, Nonsteady radial flow in an infinite leaky aquifer, Transactions, American Geophysical Union, 36, no. 1:95-100.
[xxvii] Hantush, M.S., 1956, Analysis of data from pumping tests in leaky aquifers, Transactions, American Geophysical Union 37, no. 6:702-714.
[xxviii] Hantush. M. S., 1960, Modification of the theory of leaky aquifers, Journal of Geophysical Research 65, no. 11: 3713-3725.
[xxix] De Josselin De Jong, G., 1958, Longitudinal and transverse diffusion in granular deposits, Transactions, American Geophysical Union 39:no 1:67-
[xxx] Ogata, Akio and R. B. Banks, 1961, A solution of the differential equation of longitudinal dispersion in porous media, U. S. Geological Survey Professional Paper 411-A.
[xxxi] Darton, N. H., 1901, Preliminary description of the geology and water resources of the southern half of the Black Hills and adjoining regions of South Dakota and Wyoming, U. S. Geological Survey 21st Annual Report Part IV:489-599.
[xxxii] Darton, N. H., 1905, Preliminary report on the geology and underground water resources of the central Great Plains, U. S. Geological Survey Professional Paper 32: 433 pp.
[xxxiii] Fuller, M. L, 1904, Contributions to the geology of the Eastern United States, 1903, U. S. Geological Survey Water Supply Paper 102, 522 pp.
[xxxiv] Lindgren, Waldemer, 1903, The water resources of Molokai, Hawaiian Islands, U. S. Geological Survey Water Supply Paper 77: 62 pp.
[xxxv] Lee, W. T., 1904, The underground waters of the Gila Valley, Arizona, U.S. Geological Survey Water Supply Paper 104: 71 pp.
[xxxvi] Lee, W. T., 1905, The underground waters of Salt River Valley, Arizona, U.S. Geological Survey Water Supply Paper 136: 196 pp.
[xxxvii] Menenhall, W. C., 1905, Development of underground waters in the eastern coastal-plain region of southern California, U.S. Geological Survey Water Supply Paper 137: 140 pp.
[xxxviii] Siebenthal, C. E., 1910, Geology and water resources of the San Luis Valley, Colorado, U. S. Geological Survey Water Supply Paper 240: 128 pp.
[xxxix] Meinzer, Oscar Edward, “The occurrence of ground water in the United States with a discussion of principles, U. S. Geological Survey Water Supply Paper 489: 321 pp.
[xl] Snow, John, 1849, On the mode of communication of cholera, London Medical Gazette XLIV: 730-732.
[xli] Flint, Austin, 1873, Relation of water to the propagation of fever, Public Health 1:164-172.
[xlii] Orton, Edward, 1874, Certain relations of geology to the water supplies of the county, Public Health 2:292-305.
[xliii] Sheldon, F.H. 1897, The nuisance question in gas works, Proceedings of the Northeastern Association of Gas Engineers: 314-323.
[xliv] McCallie, S. W., 1905, Experiment relating to problems of well contamination in Quitman, Georgia, U.S. Geological Survey Water Supply Paper 110: 45-54.
[xlv] Bowman, Isaiah, 1905, Disposal of oil well wastes at Marion, Indiana, U. S. Geological Survey Water Supply Paper 113: 36-49.
[xlvi] Fuller, M. L, 1910, Protection of shallow wells in sandy deposits, U.S. Geological Survey Water Supply Paper 258: 57-65.
[xlvii] Matson, G. C., 1910, Pollution of underground waters in limestone, U.S. Geological Survey Water Supply Paper 258:48-56.
[xlviii] Ballentine and Sons v. Public Service Corporation of New Jersey, 91 A 167 (1908, 1914).
[xlix] Hanson, Paul, 116, Disposal of gas house wastes, Illinois Gas Association Proceedings 12:124-135.
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[lii] Calvert, C. K., 1932, Contamination of ground water by impounded garbage waste, Journal, American Water Works Association 24:266-276.
[liii] Harmon, Burt, 1941, Contamination of ground-water resources, Civil Engineering 11(6):345-347.
[liv] Davids, H. W. and Maxim Lieber, 1951, Underground contamination by chromium waste, Water and Sewage Works, 98, no. 12:528-534.
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[lvi] Mason, William P., 1896, Water Supply (Considered primarily from a sanitary standpoint) John Wiley & Sons, New York
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