DEPARTMENT OF THE INTERIOR 

UNITED STATES GEOLOGICAL SURVEY 

GEORGE OTIS SMITH, DIRECTOR 

W ATER-S.UPPLY PAPER 255 

UNDERGROUND WATERS 

l?OR FARJ\;I ·USE 

BY 

MYRON L. FULLER 

WASHINGTON 

GOVERNMENT PRINTING OFFICE 

1910 

CONTENTS. 

Page. 

Introduction .............••.... _ .. _ ..•.... _ ...............•..• __ .•• -...... 7 

Bources of water supply ......... _ ..................• _ .•........ __ .....•... 8 

Water-bearing formations. . . . . . . . . . . . . . . . . . . ...... _ ~ .......•.•• _ ~ • . . . 8 

Classes of rocks ........... __ .... ___ . ______ . __ .... _. ____ -- __ -..••. _ 8 

Definitions of rocks._ ••..•• _ .•. _____ . ___ . ______ . _ .. ___ ..•... _ ••• _. 9 

Unconsolidated sedimentary deposits_._. __ . __ . _______ ... _. ___ . 9 

Consolidated sedimentary rocks ____ . _______ . _. _ ... _ - _. _- --.--- 9 

Igneous rocks __ .. _____ . _. _____ .. ____ . ___ . __ .. _. ____ .. ____ .. _ _ 10 

Metamorphic and crystalline rocks . _. _. _ . _ .. _. __ .. _- __ .. _. _. _ _ 10 

Fossils ..• _ . ___ .. _ . _ • ____ . _ .. _ . ____ . __ . __ ~ ___ . __ .. _ . __ •..• __ • _. 10 

Formations .....• _ .. ______ . ______ . ___ .. ___ . __ ... ____ --·- _- __ •... 10 

Structures of rocks .... __ .. _._. ___ ._ .. __ .. __ . ___ . _-- _.- __ - . -.. --- .. - 11 

Occurrence of water ___ ... ___ . _______________ ... ___ . _ . _ . _ .. __ . __ . _____ . 11 

Sand and graveL •. _ ..... __ . _. _ . ____ ... _______ .. _ .. ____ .. _____ .. _ _ 11 

Clay • _ .... _ . _ . __________ . ________________ . __ . _ . __ .. _ . _ . __ • ___ .. _ • 12 

Till •••••••••• __ ...... ___ -. _________ -- _.-. __ --- .. -. _ ... -........ -. 13 

Sandstone, conglomerate, and quartzite. _. _______ . _. _ ... _ . __ . _. _. _ _ 13 

Slate ___ ... ___ .. _. _ .••.•• ______________________ ... _ ... _. _. _ _ _ _ _ _ _ 14 

Limestone ________ ... ___ •. ______ . __ . _______ . _____________ .• ___ .•• _ 14 

Granite, gneiss, and schist . _. _____________ • _. ____ • __ •... _ .... _. _ _ _ 15 

Use of the divining rod._ ... _. _____ ._. __ . ___ . ____ .... ___ ... ___ ........ 15 

Relative safety of different materials __ . __ . ___________ ._ ... _._ •... __ ._.. 16 

Sands and gravels ________ .... ________ . ____ .....• _ ... __ -.... __ •..• 16 

Clay _ .. _ ... ______ . ____ ••. _______ .. _ . _____ ... _________ .. _ ...•• _ • . 16 

Till __ .•.... _ .. __________ . _ _ _ _ _ _ _ _ _ _ _ _ _ _ __ . __ . __ ....... _ . . . . • • . • 16 

Sandstone, conglomerate, and quartzite _ . __ ...... _ .•.. ___ . _ .. ___ . _. 17 

Shale and slate ____________ . ________ .. _ .. ____ . ____ . _. _ .. __ .. _..... 17 

Limestone __________ .. _ . ___ . _ .. ____________ . _ .. __ .... ____ ... _ . . • . 17 

Granite, gneiss, and schist _______ . _______ . ___ . __ . _____ . _. _____ . _.. 18 

Common sources of water_ ~ __ . _________ . ______ •... __ . _ ... __ . _. ___ .. _.. 18 

Lakes and ponds •.•• _ .. _ . __ . __ .. ______ ... _ . __ . ____ ...... __ . _.... . 18 

Streams _ ..•.•.. _____________ ... ____ .. ___ .•.. __ . __ .•••...... _ ... _ 20 

Springs ...••. __ ....... _ •. __ . _ .. ____ . ________ .. _ . _. _ . _. __ .. __ . • . • • 20 

VVells____________________________________________________________ 21 

Cisterns . __ .•.. __ . _ •• ___ •• _ ... ____ . __ ... _ . _ . __ . ___ .... ___ . __ • ___ . 22 

Summary __ . ___ . __ . ___ .. _ . _____ . __ . _. __ . _. ____ .. _ .. ___ .. _. _ .. _ _ _ _ 22 

Underground waters and the:ir protection . __ .. __ ... __ . _ •. __ . _ ... ___ •• __ . _.. 22 

Springs~. __ ------ ....... _ .. _ .. ___ ._._. ___ ._.---·_.----· ......•.. __ ... 22 

Kinds of springs ..••. _. ___ ... ________ • ____ • ___ . ___ .. __ . _. __ • _ •. _ _ 22 

Gravity springs ___________ . __ . __ .. ___ ..••• _ •. __ _ : ___ . _ _ _ _ _ _ _ _ 22 

Artesian springs __ .. __ . _ . _______ •.. ___ . __ . _ . _ ~ ___ •. _ ..• _ • • • . . . 22 

Seepage springs .... _ .. ___ .... _ .... _ . _ . _ ..... _ ......... _ •• __ • • 23 

Tubular springs ..•..•. _ ....•.•.• __ •..•.•..•.. _ .....•..• __ ••• _ 23 

Fissure springs _ .. _____ . ______________________ .••••.. _ . _ . __ . _ • 24 

3 
4 CONTENTS. 

Underground waters and their protection-Continued. 

Springs-Continued. Page. 

Safety of springs •............ ___ . ________ . __ ..••••••• __ •••.• _ ••• _ • 24 

Protection of springs •••.• _. ___ . __ • _____________________ . _______ .• _ 25 

Protection from stock _________ ..... __________ .. ___ . _____ ..•• _ . 25 

Protection from surface drainage . ___ . __ . ____ ~ ____ . ____ . ___ . _ _ _ 25 

Protection from wind blown and other refuse._ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 25 

Protection from subsurface drainage .... _. ___________ ._. ___ . _. _ 26 

Protection of sink holes _____ ... _ . _ .. ___ . ______ .... _______ . _ _ _ _ _ 26 

Use of lead pipes .... ___ .. __ .... __ . ___ .. _____ .. __ .. _____ ... ___ . 26 

Tests for pollution. ____ . __ . ___ . ____ . ___ .... _ ••. _ ... _. _____ ... _ 27 

Wells • _______ · .. _ .. __ . ___ .. __________________ . ___ . _ .. ___ . ________ . _ _ _ 27 

General discussion . __________ . _ . ___ .... ____ . _ . __ .. ____ . _ . . . . . . . . . 27 

Types of wells .•.. _ .. ______ . ______ . ________ . ________ . ___ . _ _ _ _ _ 28 

Types of curbs and casings. ______ . ____ ... __ ~ __ .... _ .. _ . _ .... _ . 30 

Factors governing selection of type of welL _ .. _ . ___ . ___ .... _ .... __ . ~2 

Yield of wells of various types·--··--·-----------·------------ 32 

Character of the materiaL. __ . __ -,-. ________ . ____ . ____ ._.__ 32 

Facility of entrance of water_:_ ... __ ._ ............... _. __ . 33 

Storage capacity of wells. ___ . ___ . _. _____ .. __ .. ____ .... __ . _ 33 

Depth of the water ________ ....... ____ . ____ .. _ ... _. ___ . _. _ _ _ _ 33 

Relative cost of different types of wells .................. _. _. 34 

Safety of wells . ___ . _ ... _ .. _ ........ __ ... ___ ....... _ ... ___ . . 35 

Summary._ ... _____ . ___ . __ ... _ .. _____ .. ____ ... _ ........ _ _ _ _ _ ;)6 

Open or dug wells ____________ . ___ . ___ .... ____ .... __ . _ . _ . _ .•.. _ _ _ _ 39 

Location_ • _ ..•• _____ .. ________ .. __ . . . . . . . . . . . . . . . . . . . . . . . . . . . .39 

Sources of pollution ____ . __ .. ___ .... _ ........................ _ 39 

Movement of ground ·water ................................ _. _ 41 

''Safety distance'' . ___ . ___ .. _________ . __ . ~ ~ .... _ .. __ . _ . ____ . _ _ 42 

Protection . __________ . __ ... ____ .... __ . __________ .. _____ .. __ . _ . 44 

Increasing the yield. ______ . _ .. __ . __ .. __ .. ~ ................ _ . . 45 

Deep wells ...•. _. ______ .. ___ .. ____ . ____ . __________ . __ . _____ : _. _ _ _ 46 

Location. ____ • ____ ..• __ .... __ . _____ ....... _ ......... ·. _ .... _ . . 46 

General relations. _______ ........ _ ........................ ~ . . . 46 

Relation of supply to depth ... ___ .. _...................... 46 

Relation of head to depth. ___ ............................. 47 

Relation of quality to depth ... __ ...... ~........... . . . . . . . . 48 

Summary of conclusions as to depth. ___ ... __ .... ____ .... _ _ 49 

Protection-------------·-····-------------···---------~--···· 49 

Non flowing wells. __ ...... ___ . ___ . ___ .............. . . . . . . . 49 

Flowing wells._. __ • __ .. ___ .. ___ .••....................... 51 

· Increasing the yield._._. ____ ._._._._ ..... __ ....... _ .. -.-..... 51 

Methods of increasing original yield. __ .-----.-.--.... ----- 51 

Methods of restoring lost supplies .......... -.. ----........ 52_ 

Cisterns ... _ •. __ ....... _ .... _ . _ ........ _ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54 

Advantages of cisterns ......... _. _ ....... _ ........ __ . _ .... _ ... _. _. 54 

Disadvantages._._ .. _ ..... __ ..... _ .. __ ............ _ .. _._ ...... _... 55 

Conditions under which cisterns are desirable...................... 55 

Size of cistern _ .. __ . _ . ____ . _ ..... _ . ___ . _ . _ . __ . _ ... __ . __ . _ ... ____ . . 55 

Location. _ ... ____ . __ .. _ .•. _ . __ .. __ ... _ . _ . _ .... _ . . . . . . . . . . . . . . . . . . 57 

, Construction _______ . __ . _ .. _ . _____ .... _ . _ . _ .• _ .. _ .•.•. _ . . . . . . . . . . . . 57 

Combination wells and cisterns. _____ .• _. __ ----.---.--··· ... -- ... -----. 57. 
ILLUSTRATIONS .. 

PLATE I. A, View of sedimentary rock, under microscope, showing pore 

spaces (dark); B, Water-bearing formations: Bedded sedimentary 

Page. 

rock ...................•......................... __ .. _ .... ·.... 8 

II. Water-bearing formations: A, Metamorphic rock (gneiss); B, Igneous rock (granite). _____ ._. ___ ......•........ _____ .......... - 8 

III. Water-bearing formations: A, Sandstone; B, Conglomerate........ 8 

IV. A, Rock cont.<tining fossil shells (shell marl); B, Concretions in 

sandstone ______ . _ . __ ... __ . __ . ___ . _ . _ ... _ . . . . . . . . . . . . . . . . . . . . . . 8 

V. Rock structures: A, Anticline; B, Syncline .. ___ ...... _........... 16 

VI. A, Pollution of ground water: Sewage discharging into sink hole; 

B, Occurrence of ground water: Limestone channeL.. . . . . . . . . . . . 16 

VII. Pollution of surface water; A, Outhouses along stream; B, Stock in 

pond . __ ... _ .... __ . __ ....•..... _ •........ _ . __ . _ .. _______ . . . . . . 20 

VIII. Pollution of springs: .-4-, Spring receiving wash from fertilized land; 

B, Spring receiving pollution from stock and surface wash ___ .... 24 

IX. A, Protection of springs: Properly protected spring; B, Pollution of 

springs: Spring open to falling leaves, etc ___ ....•.. ___ ._........ 24 

X. Pollution of springs: A, Spring in center of city street; B, Dairy 

spring from polluted underground stream ... __ .... . . . . . . . . . . . . . . 26 

XI. A, Open dug well; B, Bored welL .......... ---------------------- 28 

XII. Methods of sinking wells: ..A, The jet outfit; B, The driven welL... 28 

XHI. Methods of sinking wells: A, Standard portable rig; B, Rotary 

apparatus ......... : .. -------------------------·--------------- 28 

XIV. Methods of raising water: A, Pitcher pump; B, Deep-well pump... 28 

XV. Methodsofraisingwater: A, Windmill; B, Natural flow.......... 28 

XVI. Protection of wells: A, Drilled well with opening between outer 

· casing and pump tube unprotected; B, Drilled well with opening 

around casing protected by cement ...•............. _ ..•. _..... . 48 

XVII. A, Well points: B, Pulling pipe with jack .... ··-'----·------------ 52 

FIGURE ·1. Diagram showing common location of farm wells __ ..... _ .. __ ... _ _ 8 

2. Diagram showing relation between depth and permanenc) of 

wells: A, Well sunk to ordinary water level, but failing in time!'. 

of drought; B, Well sunk to level of water in dry years and 

never failing................................................. 12 

3. Diagram showing action of clays or shales in confining waters in 

sands and sandstones ...•........••. _......................... 12 

4. Relative size and storage capacity of dug and drilled wells __ ...... 13 

5. Diagram illustrating arrangement of grains in sands and sandstones with intervening pores open and capable of holding water. 13 

6. Diagram illustrating arrangement of grains in sands and sandstones with intervening pores filled with mineral matter preventing the absorption of water.............. . . . . • . . . . . • . . . . . . . 14 

7. Difference in conditions in adjacent wells in limestone ........ __ .. 14 

5 
6 ILLUSTRATIONS. 

Pagl". 

FIGURE 8. Wells in jointed rocks . . . . . . . . . . . . . . • . . . . . . . . . . . . . . . . . . . . . . . . . . 15 

9. Diagram showing possibility of pollution of wells and springs by 

material conducted from cesspool by tubular water passages in 

till - -- - . - - - - -- - - - - -- - - - - . -- - -- - - -. - - - - -- -- - - - - . - - - -- - - - - - -- - 17 

10. Limestone passage connected with sinks ........................ ~.. 17 

11. Spring f~d from unconfined waters in porous sands. . . . . . . . . . . • . . . 23 

12. Fissure spring ... ~. . . . . . . . . . . . . . . . . . . . . . . • . . . . . . . . . . . . . . . . . . . . . 24 

13. Diagram showing manner in which springs may be polluted by 

subsurface drainage. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . 26 

14. Common form of well auger.................................... 28 

15. Outfit for sinking wells by jet process........................... 29 

16. Outfit for sinking wells by rotary process........................ 29 

17. Section showing relation of water table to surface irregularities... 40 

18. Map showing position of water table by contours................ 41 

19. Artesian system showing progressively higher outcrops of the 

deeper beds. ____ .. _ ............ __ ..... _ ...... _ .. __ . _ . . . . . . . . 48 

20. Artesian system showing progressively lower outcrops of deeper 

beds .. ·-·······················----------------------------- 48 

21. Diagrams showing danger of pollution where well casing is carried 

only to rock ........ _......................... . . . . • . . . . . . . . . 49 

22. Di:agram showing" loosening" effect of shooting wells........... 51 

23. Diagram showing formation of sand packing through pumping... 52 

24. Diagram showing advantages of packing with sand and graveL... 52 

25. Section of well showing leakage into superficial deposits.......... fi3 

26. Section of well showing leakage from one deep bed into another.. 53 

27. Combination well and cistern.................................. 58 
UNDERGROUND WATERS FOR F ARlVf USE. 

By MYRON L. FuLLER. 

INTRODUCTION. 

The agricultural lands of the United States, constituting, as they 

do, almost the whole of the eastern half of the country as well as a 

very large proportion of the habitable areas in the West, deserve to 

have especial attention paid to their needs. Of these needs few are 

greater than that of purer water supplies. Farms, which are generally remote from towns, cities, or other areas of congested population, seem to be almost ideally situated for obtaining pure and 

wholesome water. In .reality, however, polluted water is exceedingly common on them (fig. 1) and typhoid-fever rates are usually 

FIGURE I.-Diagram showing ordinary location of farm well. 

greater in country districts than in cities. Typhoid fever is now 

almost universally believed to be transmitted solely through drink 

or food taken into the stomach, and is especially liable to be communicated by polluted waters obtained from shallow wells near spots 

where the discharges of typhoid patients have been thrown upon the 

ground and subsequently carried down through the soil and into the 

wells, and it is doubtless principally this fact that makes the disease 

so common in farming regions. 

Many of the failures to protect adequately the water supplies used 

for drinking arise from a lack of knowledge of the manner in which 

waters circulate through the ground and of the ways in which they 

may become polluted. Information on these subjects must needs 

7 
8 UNDERGROUND WATERS FOR FARM USE. 

be of value, and it is with the object of supplying this information, 

in so far as it may be possible to furnish it' in a brief paper, that the 

present report has been prepared. 

SOURCES OF WATER SUPPLY. 

WATER-BEARING FORMATIONS. 

All known rocks contain more or less water, and t~ough many of 

them will not yield it in useful quantities to wells all must be considered in a discussion of water-bearing formations. Many rocks are 

familiar to everyone, at least by name; others are less widely known 

and may be restricted to very small areas. The classes of rocks 

commonly recognized and the definitions of the simpler varieties are 

given below for the benefit of those not familiar with the terms in use. 

CLASSES OF ROCKS. 

In a simple classification rocks may be grouped into three divisions: 

(1) Sedimentary, (2) igneous, and (3) metamorphic. 

Sedime11tary rocks (Pl. I) are formed either of fragments worn 

from older rocks by the action of rain, wind, frost, etc., and carried 

by water, wind, or glaciers until deposited as beds of clay, sand, 

gravel, marl, loess, etc.; or of the remains of corals or of shellfish, 

such as oysters and clams. When first deposited the materials are 

loose and unconsolidated, but gradually they become hardened and 

cemented together, especially when covered by later beds, and eventually form solid rocks. These fragments or grains are commonly 

rounded, and their form may therefore help to distinguish them from 

igneous rocks, which may have corners or angles or may include 

angular crystals. 

Igneous rocks (Pl. II, B) may have come from the earth's interior 

ni. a molten state and have been forced into or through the rocks 

above them or may have overflowed as lava beds at the surface. 

They are generally made up of or at least include angular crystals, 

which may be recognized by their glistening faces, a feature that is 

not usually possessed by sedimentary rocks. Many of them are 

banded and most of them are. irregular in mass and occurrence; 

locally they may contain vividly colored patches and bands. 

Sedimentary and igneous rocks in many places have been subjected to heat and pressure after their deposition. This action may 

have further hardened them or have so greatly changed them that 

their original character can scarcely be determined. Rocks thus 

changed are known as metamorphic rocks (Pl. II, A). Mica schist · 

and marble are typical examples. As a rule they exhibit a bedded 

or banded structure. 

Rocks of all of these types occur the world over, and those of one 

locality may be indistinguishable from those of another. N otwith-
U, S. GEOLOGICAL SURVEY WATER-SUPPLY PAPER 255 PLATE I 

A . VIEW OF SEDIMENTARY ROCK UNDER MICROSCOPE, SHOWING PORE SPACES ( DARK ). 

B. WATER-BEARING FORMATIONS: BEDDED SEDIMENTARY ROCKS. 
U. S. GEOLOGICAL SURVEY WATER-SUPPLY PAPER 255 PLATE II 

A. METAMORPHIC ROCK ( GNEISS). 

B. IGN EOUS ROCK (GRANITE). 

WATER-BEARING FORMATIONS. 
U. S. GEOLOGICAL SURVEY WATER·SUPPLY PAPER 2!)5 PLATE Ill 

A. SANDSTONE. 

R. CONGLOMERATE. 

WATER-BEARING FORMATIONS. 
U. S. GEOLOGICAL SURVEY WATER -SUPPLY PAPER 256 PLATE IV 

A . ROCK CONTAiNING FOSSIL SHELLS (SHELL MARL). 

B. CONCRETIONS IN SANDSTONE. 
WATER-BEARING FORMATIONS. 9 

standing these similarities, they may have been formed under very 

different conditions and at periods thousands or even Inillions of 

years apart. Resemblances between rocks do not, therefore, mean 

'that they were formed at the same time or will yield the same products, such as coal or oil or water. 

DEFINITIONS OF ROCKS. 

Simple definitions of the more common rocks are given below. 

Complete descriptions arrd definitions of rarer varieties may be found 

in any text-book on geology. 

UNCONSOLIDATED SEDIMENTARY DEPOSITS. 

Gravel, sand, and clay are made up respectively of pebbles, sand 

grains, and fine silts worn from older rocks and redeposited in their 

present form. 

Alluvium is a general term for gravels, sands, and clays, or mixtures of these that have been deposited by streams. 

Chalk is a soft white earthy form of limestone. 

Marl is a clay with much intermingled calcareous material. 

Till is a heterogeneous mixture of clay, sand, pebbles, and bowlders 

deposited by glaciers. 

Hardpan is a general term which may be applied to any bed which 

is considerably harder than those with which it is associated. It is 

often applied to till, to tough clays, or to partly cemented sand or 

clay beds. 

CONSOLIDATED SEDIMENTARY .ROCKS. 

Conglomerate (Pl. III, B) is a consolidated gravel. 

Sandstone (Pl. III, A) is a consolidated sand. It is said to be 

massive if there are few bedding planes, and shaly if it splits into 

plates. 

Quartzite is a sandstone in which the spaces between the grains 

have been fUled with a hard cement (silica), forming an excessively 

hard rock. 

Shale is consolidated clay; a soft, fine-grained rock which tends 

to split into thin plates. It is sometimes improperly called soapstone. 

Limestone is composed mainly of carbonate of lim~, but often 

contains sand and other· impurities, and may be very hard. Not 

infrequently it contains many shells or is made up entirely of them. 

It can be most readily recognized by the bubbling which takes 

place. when it is touched with hydrochloric (muriatic) acid. In 

varieties high in magnesia and in ,magnesium carbonate, or dolomite, 

hot, strong muriatic acid is necessary to produce this action. 

Tuff is. any sedimentary rock that is made up entirely or almost 

entirely of fresh fragments of volcanic rocks. 
10 UNDERGROUND WATERS FOR FARM USE. 

Concretions (Pl. IV, B) are hard, lumplike masses within the rock. 

They should not be confounded with real bowlders, from which, as a 

rule, they may readily be distinguished, because they consist of 

nearly the same material as that in which they are embedded. 

IGNEOUS ROCKS. 

Granite is a wholly crystalline rock, composed of quartz, feldspar, 

and other light-colored minerals. 

Diorite, gabbro, and diabase are crystalline rocks similar to 

granite, but with less quartz and with dark-colored feldspars. 

Volcanic rocks, lavas, etc., are rocks that have been emitted in a 

molten state from volcanoes. 

Trap is a widely distributed, compact, very dark colored variety 

of volcanic rock. Technically it is a basalt or diabase, and these 

terms are in comn1on use. 

METAMORPHIC AND CRYSTALLINE ROCKS. 

Slate is like shale, but harder; it splits into thin plates which may 

or may not coincide with the bedding. The tendency to split is not 

often recognized in drilling. Roofing slate is a familiar example. 

Marble is a crystalline limestone, and gives the same reaction 

with acid as limestone, marl, and chalk. 

True soapstone is a soft, even-grained, greasy-feeling rock composed of the mineral talc, but the term is incorrectly applied to any 

soft, greasy-feeling rock, such as soft shale. 

Schist is a more or less crystalline rock which has a laminated 

structure, due to the flat crystals of mica or other minerals of which 

it is composed. 

Gneiss is similar to granite in composition, but has a less perfect 

crystalline structure and a banded structure due to the linear arrangement of its crystals. . 

FOSSILS. 

In many sedimentary rocks remains of animals and plants are 

found. (See Pl. IV, A.) These generally consist of portions or 

impressions of shells, skeletons, or leaves, and are known as fossils. 

A bed may be recognized and determined by such remains, which 

are therefore of great importance in geologic work. In the oldest 

rocks only low organisms, such as shellfish, are found, but in later 

rocks, fishes, reptiles, and mammals progressively appear, while 

vegetation shows a corresponding change of its predominant types 

from microscopic forms to the forest trees of to-day. 

FORMATIONS. 

A rock bed or a succession of beds that are uniform in character 

throughout a considerable area is termed a formation and is given 
OCCURRENCE OF W ATE11. 11 

a geographic name derived from some place or feature in the area 

where it typically occurs, such as Trenton limestone. The correct 

identification of formations is very important in underground-water 

studies, as by this means the structure and position of water-bearing 

beds is worked out. 

STRUCTURES OF ROCKS. 

When deposited, sedimentary beds are nearly horizontal, but they 

may be subsequently thrown into inclined positions, or bent into 

arches or troughs, or broken and displaced. It is rather unusual, 

in fact, to find in the interior of the continents any sedimentary 

beds which have not been tilted, folded, or otherwise disturbed, at 

least slightly. Some of the terms used to designate the structures 

that result from these disturbances are as follows: 

An anticline (Pl. V, A) is the arched part of a rock fold. 

A syncline (Pl. V, B) is the trough of a rock fold. 

A fault is a rock fracture the sides of which have been displaced 

from their original position with reference to one another. 

The dip of a bed is the angle by which it deviates from the horizontal plane. 

Strike is the compass direction of the intersection of an inclined 

bed with a horizontal surface. 

A joint is a plane of fracture or crack in a rock the sides of which 

have not been materially displaced with reference to one another. 

Cleavage planes are minor planes traversing a rock, as a rule in 

one direction, and in many rocks are simply lines along which the 

rock tends to split rather than. actual fractures. They are commonly due to the action of pressure on compact rocks., 

Foliation and schistosity are planes of easy splitting, due to the 

arrangement of the minerals of the rock with their elongated directions parallel with one another. 

OCCURRENCE OF WATER. 

All rocks contain more or less water, which either occupies. perceptible cavities in the rock or occurs within the minute pores. 

The water in the pores is given up readily only by the coarser rocks, 

such as sandstones, the fine-grained rocks yielding very little of 

such water when penetrated by the drill. Water found in these 

·rocks usually comes from the joint, fault, or foliation planes. The 

conditions of the occurrence of water in various rocks differ widely. 

SAND AND GRAVEL. 

Sands and gravels are very porous. Thirty per cent of the volume 

of some sand or gravel deposits are made up of free space between the 

grains. lmt;uch material the whole mass below ground-water level is 
12 UNDERGROUND WATERS FOB FARM USE. 

saturated, and when penetrated by wells yields copious supplies. 

The waters of such deposits are, its a rule, of good quality, but some 

are mineralized, having dissolved material from the more soluble 

fragments and particles that constitute the deposits. 

The cheapest and best method of obtaining small supplies of water 

from sands and fine gravels is by driven wells, which can be sunk 

A B 

quickly and at slight 

cost. It is difficult, 

however, to exclude 

1-=._v~ _ i~ _o!:.?i_r: 6_!" ~ ..2'~ !:._5 _ _ very fine sand or quieksand from pipes, quick-

- _v:!.6.!.':.! __ 1.=v....=l_ ~-d.!:Y_ ~e~r.=_ ---- sand frequently peneFIGURE 2.-Diagram showing relation between depth and perma- trating the well and nence of wells.-A, Well sunk to ordinary water level, but failing clogging the pipe or at times of drought; B, well sunk to level of water in dry years 

and never failing. ruining the pump. 

Because of the readiness with which sands and gravels yield their water, wells sunk 

close together in such deposits may affect one another, the well that 

draws from the sand at the lowest level taking the water from the 

higher wells. The readiness of mdvement of the water also causes 

important fluctuations of the water in the ground, the water level rising and falling rapidly with the beginning and cessation of rain. To 

obtain permanent supplies, wells should penetrate to a level below 

that of the ground-water surface in the driest seasons. (See fig. 2.) 

CLAY. 

Clay usually contains large quantities of water, but its pore spaces 

ares~ fine or small that water soaks into it or out of it so slowly that 

it is impervious in the sense that little or none of that which it contains can be utilized as a source of supply. Considerable amounts are 

frequently reported in clays, but they usually come from more or less 

sandy layers. In some places sand that approaches clay in fineness 

and that is sometimes mistaken-for clay yields considerable amounts 

of water. Clay is of the greatest importance, however, not as. a waterFIGURE 3.-Diagram showing action of clays.or shales in confining water in sand or sandstone. 

bearer, but as a confining layer which prevents the water from escaping, or as a layer collecting the water from overlying porous beds and 

bringing it to the surface. (See fig. 3.) 

When, because of the absence of other sources, it is necessary to 

obtain supplies from clay, a well sunk should be of as la~e diameter 

as possible arid should be continued far enough beneath41fhe point at 
OCCURRENCE OF WATER. 13 

which water is obtained to insure ample storage capacity. (See fig. 

4.) Dug wells are usually most satisfaetory where the clay is near 

the surface, but such wells should be carefully covered and guarded 

from all sources of pollution. 

TILL. 

Till is a heterogeneous mixture of clay, sand, gravel, and bowlders, 

deposited by glaciers. In te~ture it varies from porous to· impervious, according to whether sand or clay predominates. It is, as a 

rule, not definitely bedded. The 

water that it contains generally 

occurs in small more or less tubular channels a few inches in 

diameter, but here and there is 

-

distributed through interstrati- FIGURE 4.-Relative size and storage capacity of dug 

and drilled wells. fied sandy beds. 

In the aggregate, till yields a large amount of water, being the prevailing source of supply in the rural districts at a great number of 

points throughout. the northern portion of the country. Because of 

the occurrence of the ~ater in definite channels, however, the success of wells i~ till varies greatly. In general, wells of large diameter give the best success. Figure 4 represents two wells of the same 

depth, one dug and one bored. It will be seen that in the dug well 

not only is a larger amount of material encountered in cross section, 

but the area of surface from which water can enter is many times 

greater than in the bored well. The open well is also of larger 

FIGURE 5.-Arrangement 

storage capacity, and can be employed to utilize 

small supplies-supplies that would be insufficient 

to furnish enough water to.a bored well. 

SANDSTONE, CONGLOMERATE, AND QUARTZITE. 

or grains in sands and Sandstone is, on the whole, the best water bearer 

sandstones with intervening pores open and of the solid rocks. Under the most favorable concapable of holding ditions sandstone is saturated throughout its ex- water. tent below the regular ground-water level, and 

wherever it is struck by the drill within these limits (see fig. 5) it 

yields water freely, as a rule, although some of the finer-grained sandstones yield it less readily. In quality the water in sandstones is, as 

a rule, better than that in any other material except sand and gravel. 

Drilled wells are used to recover water from sandstone except where 

it is very near the surface. 

Some conglomerates furnish considerable water, although, as a rule, 

the absorptive power of conglomerates is not so great as that of sandstones, and they are much less frequently encountered. 

Quartzite is a sandstone in which the spaces between the grains 

have been filled by hard siliceous matter. Because of the filling of 
14 UNDERGROUND WATERS FOR FARM USE. 

the pores by this material there is relatively little chance for the water 

to enter, and the rocks are not commonly an important source of 

supply. (See fig. 6.) 

SLATE. 

FIGURE 6.-Arrangement of 

grains in sands 

and sandstones 

with intervening 

pores filled with 

Slate, like clay, is a poor water bearer but may yield 

water from crevices along bedding, joint, and cleavage planes. Its most important use with reference 

to water supply, is as a confining layer to prevent the 

escape of water from porous sandstones which may 

be interbedded with it. The waters in slate are 

reached by deep wells and are generally uncontaminated but are not uncommonly mineralized. 

mineral matter LIMESTONE. 

preventing the 

absorption of Waters occur in limestone mainly in open channels 

water. (Pl. VI, B), caverns, etc., dissolved in the rock by the 

water itself. The water 

originallyprobablyfollowed 

joint or bedding planes 

which were gradually enlarged Ly solution into the 

caverns that now exist. 

The occurrence of caverns and passages within 

the limestone is very irregular, and their location can FIGURE 7.-Difi'erence in conditions of adjacent wells in lime- stone. seldom be predicted. Most 

deep wells which are drilled in limestone regions, however, encounter 

FIGURE 8.-Wells in jointed rocks. 

in limestone are generally hard but are not 

mineralized. 

one or more such 

passages at a relatively slight distance 

below the surface. 

Wells in limestone, 

even where only a few 

feet apart, may 

nevertheless obtain 

very different results, 

as a difference of a 

foot or two may 

mean the missing 

of a certain channel, 

as indic~ted in figure 7. The waters 

commonly otherwise 
USE OF THE DIVINING ROD. 15 

GRANITE, GNEISS, AND SCHIST. 

Granites and gneisses are very dense and possess very small pore 

spaces, and most of these rocks hold very little water. In schists, 

however, considerable water often penetrates along the foliation planes 

and is held by the rock, but such water is given up very slowly and is 

not important as a source of supply. 

It is along the joints in these rocks that the largest supplies are 

obtained. (See fig. 8.) These joints are most common near the 

surface and diminish in number an'd in definiteness as the depth 

increases. For this reason the water supplies from such rocks, if 

obtained at all, are usually found within 200 or 300 feet of the sprface. 

It is generally useless to go deeper than 500 feet for waters in these 

crystallip.e rocks, although in some places, as at Atlanta, Ga., water 

is said to have been obtained at depths as great as 1,600 feet. 

.. USE OF THE DIVINING ROD . 

Numerous mechanical devices have been proposed for detecting 

the presence of underground water, ranging in complexity from the 

simple forked branch of witch-hazel, peach, or other wood to more 

or less elaborate mechanical or electric contrivances. Many of the 

operators of these devices, especially those who use the hmne-cut 

forked branch, are entirely honest in the belief that the working of 

the rod is influenced by agencies-usually regarded as electric currents following underground strea1ns of water-that are entirely 

independent of their own bodies, and many uneducated people have 

implicit faith in their ability to locate underground water in this 

way. In experiments with a rod of this type the writer found that 

at certain points it seeme~ to turn downward independent of his will, 

but more complete tests showed that this down turning resulted from 

slight. and, until watched for, unconscious muscular action, the effects 

of which were communicated through the arms and wrists to the rod. 

No movement of the rod from causes outside of the body could be 

detected and it soon became obvious that the view held by other men 

of science is correct-that the operation of the "divining rod" is 

generally due to unconscious movements of the body or of the 

1nuscles of the hand. The experiments made show that these movements happen most frequently at places where the operator's experience has led him to believe-that water may be found. 

The uselessness of the divining rod is indicated by the facts that it 

may be worked at will by the operator, that he fails to detect strong 

water current in tunnels and other channels that afford no surface 

indications of water, and that his locations in limestone regions where 

water flows in well-defined channels are no more successful than those 

dependent on mere guesses. In fact, its operators are successful 
16 UNDERGROUND WATERS FOR FARM USE. 

only in regions in which ground water occurs in a definite sheet in 

porous material or in more or less clayey deposits, such as pebbly 

clay or till. In such regions few failures can occur, for wells can get 

water almost anywhere. Ground water occurs under certain definite 

conditions, and just as surface streams may be expected wherever 

there is a valley, so ground water may be ·found where certain 

rocks and conditions exist. No appliance, either mechanical or 

electrical, has yet been devised that will detect water in places where 

plain common sense will not show its presence just as well. The 

only advantage of employing a "water witch," as the operator of 

the divining rod is sometimes called, is that crudely skilled services 

are thus occasionally obtained, since the men so employed, if endowed 

with any natural shrewdness, become through their experience in 

locating wells better observers of the occurrence and movements of 

ground water than the average person. 

RELATIVE SAFETY OF DIFFERENT MATERIALS. • 

The safety of the water supplies used for drinking purposes when 

near any source of pollution, depends principally upon the character 

of the openings through which the water passes, and this in turn 

depends on the nature of the materials in which the water occurs or 

through which it has passed. 

Sands and gravels.-In passing downward through sand surface 

waters are subjected to natural filtration, especially in the finer 

varieties, and the substances with which they 1nay have originally 

been polluted are frequently removed, at least in part. In coarser 

sands and in gravel the water passes downward more rapidly; the 

conditions are less favorable for filtration, and the ·water may remain 

polluted. In general, however, waters fron1 sands and gravels, if 

taken from a considerable distanee below the surface, are safe to use. 

Olay.-The waters of clays, because of the fineness of the material, 

come into contact with relatively large amounts of mineral matter 

and frequently become mineralized, lime and salt being the most 

common substances dissolved; as a rule, however, owing to the filtration of the waters through the exceedingly fine material and the 

slowness with which polluting matter progresses and the slight distance to which it reaches in such material, they are free from contamination. · 

Till.-The water of till is generally uncoutaminated because of the 

natural filtration due to its slow downward penetration through the 

clay and sand of which the till is largely composed. In some places, 

however, springs have formed more or less definite tubular channels 

through the material, and if such a channel leads from a cesspool or 

similar source of pollution the water becomes highly charged with 

matter dangerous to the health. Once contaminated it is likely to 
U. S. GEOLOGICAL SURVEY WATER-SUPPLY PAPER 255 PLATE V 

A. ANTICLINE. 

H. SYNC LI NE. 

ROCK STRUCTURES. 
U. S. GEOLOGICAL SURVEY WATER ·SU PPLY PAPER 255 PLATE VI 

A . POLLUTION OF GROUND WATER: SEWAGE DISCHARGING INTO SINK-HOLE. 

B. OCCURRENCE OF GROUND WATER: LIMESTONE CHANNEL. 
RELATIVE SAFETY OF DIFFERENT MATERIALS. 17 

continue so for long distances, as little natural filtration takes place, 

because of the nature of the channel. (See fig. 9.) The water from 

till should be thoroughly tested by a bacteriologist if there seems any 

likelihood of contamination. 

Sandstone, conglomerate, and quartzite.-The waters in these materials are very rarely polluted, owing in the more porous varieties to 

the natural filtration and in the compact varieties to the difficulty 

with which contaminated waters penetrate them. In quartzitic rock, 

Cesspool 

FIGURE 9.-Diagram showing possibility of pollution of wells and springs by material conducted from 

cesspool through tubular water passages in till. 

however, joint fractures may ad1nit both water and polluting materials from the surface. 

Shale and slate.-Like the waters of clays and for the same reasons, 

the waters of slates and shales suffer very little pollution. 

Limestone.-In the vicinity of buildings or settlements the waters 

of limestone are frequently contaminated and unfit for use. This is 

not because of the amount of lime dissolved, but because of the fact 

that the water falling on the surface as rain often plunges directly 

through basins or sinks into the underground channels instead of 

slowly filtering downward through the soil and into the rock, as in 

most other materials. This water carries with it the impurities 

washed or otherwise brought to the sink and bears them along 

Sink Sink 

FIGURE 10.-Limestone passage connected with sinks. 

through underground passages to distant points. (See fig.lO.) It is 

a common practice to dump manure, sewage, and other refuse into 

these sinks, regardless of the fact that it will eventually enter the 

underground water body. Fortunately in the United States many 

limestone regions are thinly inhabited, so the danger is not perhaps 

so widespread here as elsewhere. When springs which have been 

guarded from surface wash become muddy after a rain it is safe 

to assume that surface impurities have had access to the grounP, 

46449°-W s P 255-10--2 
18 UNDERGROUND WATERS FOR FARM; USE. 

water through the sinks or otherwise, and such waters should be 

avoided. 

Granite, gneiss, and schist.-The joints in these rocks generally 

occur in complex systems of intersecting planes, and it is possible for 

polluted water starting very near the mouth of the well to pass in a 

zigzag course downward along the joints, finally reaching the well at 

a depth of many hundred feet (fig: 8); such was the case in a well. at 

Atlanta, Ga., which finally had to be abandoned. For this reason 

wells drilled in broken and jointed igneous rocks in cities and other 

thickly populated regions are liable to pollution. Waters from such 

wells, if they are to be used for drinking, should be tested occasionally 

to determine whether they are polluted or not. 

COMMON SOURCES OF WATER. 

The sources of the water used on the farm are numerous-lakes, 

streams, springs, drilled, bored, driven, and dug wells, and cisterns 

all being extensively used, although the water from lakes and streams 

is generally used only for stock. Each of these sources under some 

conditions may yield entirely safe and satisfactory supplies, while 

under other conditions certain of them may be a constant menace to 

the health. 

Lakes and ponds.-The waters of lakes and of large ponds, which 

here include all fresh-water bodies half a mile or more in diameter, are 

generally good, except when they are polluted by the drainage or 

sewage from cities or large towns on their shores or on the lower 

courses of tributary streams. In ponds and in the smaller lakes such 

pollution may render the entire body of water unsafe for domestic use. 

Sunlight, however, has a marked purifying action, tending to 

destroy the dangerous germs, while, under the action of winds, wave 

action and circulation are induced in the water, favoring aeration 

(mixture with air), which, by oxidation, likewise helps to remove 

the dangerous impurities. At the same time the heavier sediment 

brought in by the streams is constantly settling to the bottom. As a 

result of all these processes of purification, the water which entered in 

a polluted state may at last become so changed that on leaving the 

lake at its outlet it is both palatable and wholesome. 

So rapidly has this purifying action been supposed to take place 

that before the construction of the Chicago drainage canal it was 

thought safe by some to draw the supply of the city from Lake Michigan at a distance of only a few miles offshore. Experience proved, 

however, that while noticeable pollution was confined to a relatively 

small portion of the lake, and while normally the city supply was 

fairly safe, it was, nevertheless, under eertain conditions of wind and 

currents, liable to pollution. It was thus necessai·y either to remove 

the intake to a point several miles farther away or to divert the sew-
COMMON SOURCES OF WATER. 19 

age from the lake. The Chicago drainage canal, by diverting the 

sewage, has done much to solve the problem. 

Nat ural lakes are confined almost wholly to the northern portion 

of the country, where they form a belt extending from eastern North 

Dakota to eastern Maine. In this belt, besides the Great Lakes, there 

are tens of thousands of smaller lakes, Minnesota alone having several 

thousand. 

Most of the lakes, especially the smaller ones, are in thinly inhabited 

regions and afford supplies of high purity. Unfortunately, however, 

owing to the fact that farmhouses, even if in the vicinity of lakes. are 

usually placed on high ground at some distance from the water it is 

necessary, if the lake is used as a source of supply, to haul the water 

required for domestic purposes. Because of the inconvenience 

thereby entailed few of the lakes are used, although they constitute 

ideal supplies for horses and cattle and furnish pure water to those 

cities which lie within convenient piping distance from them. 

In the smaller water bodies, varying from mere pools to lakelets 

several acres in extent, there is less dilution of the impurities washed 

into then1 than in the lakes and large ponds, and even where there 

are both an inlet and an outlet there is often a tendency for the main 

current to pass directly from the inlet· to the outlet without mixing 

with the water as a whole, the greater part of the lake thus remaining 

relatively stagnant. The entrance of a very slight amount of polluting matter into such waters may dangerously affect their quality. 

Owing to the slight circulation in these small bodies of water decaying leaves and twigs will frequently accumulate and, together with the 

growth of water organisms, will give the water an amber or even a 

dark-brownish color and a noticeable taste. Such coloration does 

not make the water dangerous any more than the green algous slime 

that collects on the surface (most of which is perfectly innocent), but 

both are indications of stagnant conditions that are repugnant to the 

mind and may mask dangerous impurities. On the bottoms of ponds 

of this sort there are usually accumulations of decaying vegetable 

matter ll.lixed with silt, which are very objectionable in water to be 

used for drinking. It is such accumulations which give off the bubbles of gas that may be seen rising to the surface when the bottom is 

disturbed. 

Not all small ponds, however, should be condemned because of their 

size. Many are fed by springs, are free from pollution, and contain 

water as clear and cool as could be desired. Such ponds may be used 

t<? advantage for domestic supplies, although as the farmhouses are 

usually situated at a distance from the water they are seldom used 

except for watering stock. 

In some of the prairie and semidesert regions, where streams are 

relatively few in number or even absent over large areas and where 
20 UNDERGROUND WATERS FOR FARM USE. 

wells do not yield sufficient supplies, water is often obtained from artificial ponds. These are usually formed by throwing up a low embankment across some shallow depression or flood-water channel, behind 

which the rain water or the brief flood flow accumulates. Such reservoirs are commonly but a few rods in diameter and a few feet in 

depth. As a consequence the water becomes heated in summer, is 

usually kept constantly muddy by the movements of stock, and is 

highly polluted by them. (See Pl. VII, B.) As numerous animal diseases may be communicated through drinking water, small ponds of 

this sort may become a source of great danger. 

Many of the water pockets or ''tanks'' of the deserts, in part natural 

and in part artificial, are also entirely unsafe even for stock use, 

although as they constitute the only source of water in many regions 

such use is unavoidable. In fact, the upbuilding of considerable 

grazing industries has been made possible by such water pockets in 

otherwise waterless .regions. 

Streams.-Over a large part of the country streams and rivers form 

the most available sources of supply, and in thinly settled regions they 

are usually free from contamination, although even here a tan-bark 

plant or sawmill may lessen the desirability of the water for domestic 

purposes. 

Mines, especially coal mines, may likewise discharge their drainage 

of acid and otherwise polluted waters into the streams with similar 

effects, but the most common source of pollution is the sewage from 

towns and cities. In fact, practically all the larger streams, and even 

many of the smaller ones, are highly polluted by such sewage or by 

refuse from various manufacturing plants. It is true that such 

streams become gradually purified and under ordinary conditions may 

be fairly safe, but the periodic outbreaks of typhoid fever that occur 

among the users of their water are sufficient to indicate the imperfect 

nature of this purification. 

Large cities without other accessible sources will doubtless continue 

to use river waters, but these waters are now, as a rule, scientifically 

filtered before distribution. On most farms, however, other and safer 

sources are available, and stream waters which are known to have 

received drainage or sewage from any source should not be used for 

drinking. (See Pl. VII, A.) In the larger strean1s the pollution is 

rarely high, and many of them will afford satisfactory supplies for 

stock. 

Springs.-Springs usually form an ideal source of farm supply. 

Occurring in great abundance in many of the thinly settled regions 

and coming from considerable depths within the rock or filtering from 

sand or gravel, they are almost always free from pollution except 

where buildings are situated on the hillsides above them or where 

surface wash is allowed to enter them. 
U. S. GEOLOGICAL SURVEY WATER - SUPPLY PAPER 255 PLATE VII 

A. OUTHOUSES ALONG STREAM. 

B. STOCK IN POND. 

POLLUTION OF SURFACE WATERS. 
COMMON SOURCES OF WATER. 21 

In the more hilly r~gions, such as those of New Hampshire and 

Vermont, especially where the farms lie in the valleys, the water from 

hillside springs can usually be piped with little difficulty to the house 

and barn, where it flows as a steady stream under the influence. of 

gravity alone. A farm supplied from such a source is fortunate 

indeed. 

Natural spring water is almost never dangerous to health, as the 

minerals it contains in solution are generally ha:r:mless, although a few 

waters act as a physic and others may contain sulphur gases in disagreeable amounts. 

Wells.-Dug wells, because of the ease with which they may be 

constructed by the farmer himself when other work is not pressing, 

require little money outlay and are therefore very popular. As commonly sunk, however, they are the most dangerous of all sources of 

water, but with certain precautions, discussed elsewhere (p. 44), they 

may be made to yield satisfactory supplies. 

Driven wells consist of iron pipes, equipped with point and strainer 

at the end, which are forced into the ground by blows on the top of 

the pipe. The joints are water-tight; hence the polluted waters near 

the surface can not possibly enter. Such wells are also very cheap 

and, in fact, possess advantages which make them most desirable. 

The fact that they can be put down only in soft materials, where no 

very hard beds or large bowlders are to be encountered, however, 

limits their use. 

Drilled wells, usually from 2 to 12 inches in diameter, are sunk by 

machinery in materials too hard or too irregular to permit driving or 

in places wliere greater depths are required than can be reached by 

driving. In all soft materials which will not stand by themselves, or 

in material through which undesirable water might enter, an iron pipe, 

known as the" casing," is inserted, shutting off all impurities. Drilled 

wells are usually of considerable depth, some of them being carried to 

2,000 feet or more if water is not found at higher levels. In granites 

and similar rocks most of the water is found within 300 feet of the 

surface, and if a supply is not obtained within that depth it is better 

to start a new well than to drill the old one deeper. 

The chief disadvantage of such deep waters is the large amount of 

mineral matter which they may contain and which makes them unfit 

for boiler and manufacturing purposes. But to the farmer this feature is usually of no consequence. To him the principal qu~stion is 

the cost. The deeper wells are of course usually beyond ·his reach, 

but fortunately water ca:q,~gften be found relatively near the surface. 

Moreover, such waters, contrary to the common belief, usually contain 

less mineral matter than the deeper waterE~ and can often be obtained 

in larger amounts. 
22 UNDERGROUND WATERS FOR FARM USE. 

Oisterns.-Where a satisfactory supply can not be obtained from 

the ground, or where the ground water is hard and soft water is 

required for certain purposes, the rain falling on the roofs of the farm 

buildings is often utilized. It is conducted by pipes to shallow welllike excavations, which are commonly made at least approximately 

water-tight by linings of cement or other impervious material. When 

thus made they are generally safe to u~e, and the waters, being very 

soft, are highly prized for domestic purposes; but if cracks allow the 

outside waters to enter, cisterns are as liable to contamination as dug 

wells. 

Summary.-Of the various sources of water supply the ground 

water is the most satisfactory for farm use, because it is least liable 

to pollution, and streams and ponds are the most unsatisfactory, 

because of the ease ap.d frequency with which they are contaminated. 

Fortunately, however, the latter are very seldom used for drinking 

and domestic purposes, being utilized mainly for stock, on which the 

effect of moderate pollution is not apparent. The underground supplies, whether from wells or springs, although safe in many localities, 

are far from being universally so, the safety depending mainly on 

their location and on the nature of their protection. These are discussed in the following sections. 

UNDERGROUND WATERS AND THEIR PROTECTION. 

SPRINGS. 

The term "spring" is properly applied to the water emerging from 

the ground at a single point or within a restricted area. The distinction between springs and general seepage, however, is not always 

very sharp, for there are all gradations between the concentrated 

outflows characterizing true springs and the diffused emergence of 

water over large areas or beneath the level of the water in streams. 

Springs may be divided, according to their mode of origin, into 

gravity and artesian springs, and, according to the nature of the passages traversed by the water, into seepage, tubular, and fissure 

springs. 

KINDS OF· SPRINGS. 

Gravity springs.-A gravity spring is one whose water is not confined between impervious beds but flows from loose materials or open 

passages under the action of gravity, just as a surface stream flows 

down its channel. The conditions are shown in figure 11. 

Artesian springs.-An artesian spring is one whose waters are confined in impervious channels or between impervious beds and are 

under hydrostatic pressure because the water level at their source is 

higher than the point where they emerge. The waters of such a 

spring, if confined in a pipe instead of being allowed to flow out upon 

the ground, may rise considerably above the spring mouth. 
SPRINGS. 23 

Seepage springs.-Seepage springs. are springs in which the water 

seeps out of sand or gravel; they differ from general seepage only in 

being restricted to a small area. Such springs are usually marked 

· by abundant vegetation at their points of emergence, and their waters 

are often colored or carry an oily scum due to the decomposition of 

vegetable matter or the presenc'e of iron. The scum is frequently mistaken for petroleum. The waters of the seepage springs commonly 

come from no great distance beneath the surface and are not usually 

very cold. 

Seepage springs may emerge along the top of an underlying impervious bed, but more comn1only they occur where valleys are cut 

downward into the zone of saturation of a more or less uniform waterbearing deposit. Under favorable conditions the seepage from sands, 

as on Long Island, New Yor~, gathers into channels and forms streams 

of considerable size, some of them flowing 5,000,000 gallons or more 

daily. 

Seepage springs, as in the cases cited, are commonly of the gravity 

type, but where channels or fissures emerge beneath beds of sand or 

gravel seepages not infrequently result from true artesian springs. 

FIGURE 11.-Spring fed from unconfined waters in porous sands. 

Tubular springs.-Tubular springs embrace a great variety of 

flows, including both those in the small more or less tubular passages 

in the drift and those occupying large solution channels or caverns in 

the soluble rocks. 

The channels of springs in the drift are generally established along 

some more or less· sandy or other porous layer, or perhaps along the 

path left by a decaying root. The motion at first appears to have 

been mainly that of seepage, but in many springs a passageway has 

been gradually opened, along which a definite stream finds its way. 

The waters reach the channels by percolation through the clays and 

sands and are usually free from pollution except when near cesspools 

or vaults sunk some distance into the ground. 

In limestones and other soluble rocks the underground passages 

may reach many miles in length. Single passages, as in the Mammoth 

Cave of Kentucky, have been traversed for a distance of nearly 10 

miles, and passages several times as long, though as yet undiscovered, probably exist. Some of these passages are many feet in diam-
24 UNDERGROUND WATERS FOR FARM USE. 

eter and are traversed by streams of considerable size, or even by 

rivers. The Silver Springs of Florida give rise to a river which is 

navigable from the ocean to its source in the springs, and springs of 

similar volume occur at other points in Florida and Arkansas and 

possibly elsewhere. The waters of such springs vary greatly in composition, although most of them are hard. In some springs the 

waters are exceedingly clear, the bottoms being distinctly visible at 

a depth of many feet, but in other~ the waters are muddy after severe 

storms. When clear it is probable that the waters feeding the underground stream reached it by percolation through the porous earth or 

rock, during which its impurities were largely removed. When 

muddy the waters in part appear to have penetrated downward 

through sinks or to have entered the rock directly as streams; in 

either case they are very liable to pollution by impurities washed in 

with the water. 

Tubular springs are most commonly of the gravity type, the channels generally sloping from higher to lower levels. In both drift and 

limestone, however, there are numerous exceptional springs whose 

channels are at some points in their courses considerably lower than 

FIGURE 12.-Fissure spring. 

their outlets. Under such conditions the water may be under considerable artesian pressure in the lower parts of its channel or even at 

its outlet. 

Fissure spring8.-The term fissure spring is here used rather comprehensively to include the springs issuing along bedding, joint, 

cleavage, or fault planes. (See fig. 12.) The distinguishing feature 

is a break in the rocks along which the waters can pass, it being immaterial whether any considerable open space exists. These springs 

differ from tubular springs in that they are as a class of deeper-seated 

origin, as is attested by their temperatures. The waters are almost 

never subjected to contamination, though in many springs they are 

highly mineralized. Springs of this class are often distributed along 

straight lines for considerable distances, their position being determined by lines of fracture or jointing. 

SAFETY OF SPRINGS. 

Springs from sands, sandstones, clays, sl1ales, and slates are seldom 

polluted, except where contaminating matter penetrates through 
U. S. GEOLOGICAL SURVEY WATER · SUPPLV PAPER 255 PLATE Vl!l 

A. SPRING RECEIVING WASH FROM FERTILIZED LAND. 

B . SPRING RE CEIVING POLLUTION FROM STOCK AND SURFACE WASH. 

POLLUTION OF SPR INGS. 
U. S. GEOLOGICAL SURVEY WAT ER-SUPPLY PAPER 255 PLAT E I X. 

A. PROPERLY PROTECTED SPRING. 

B . SPR ING OPEN TO FALLING LEAVES, ETC. 

POLLUTION OF SPRINGS. 
SPRINGS. 25 

cracks or fissures, or through the material itself where the covering 

above the water is very thin. Usually such pollution is likely to 

occur only where houses, barns, sewers, or cesspools are located on 

higher ground near the spring, or more especially where cities or 

towns are so located. In limestones, on the contrary, sewage or 

other polluting matter frequently enters the underground channels 

through the sinks (Pl. VI, A) and may contaminate the underground 

water for long distances. Similarly in the tubular channels in the 

till, if material from a cesspool or other source of pollution finds access, 

the water may retain its contamination for a long period and a great 

distance. 

PROTECTION OF SPRINGS. 

Protection from stock.-One of the most common causes of contamination of springs in the farming districts arises from failure to 

fence the springs to prevent the aceess of stock. Plate VIII, B, shows 

a mineral spring in Georgia from which many people drink and from 

whieh the waters have at times been shipped, but about whieh stock 

are nevertheless allowed to roam freely, drinking from it at will and 

incidentally eontaminating it in a variety of ways. It is needless to 

say that any spring used for drinking water should be carefully fenced 

at such a distance as to prevent any excrement from reaching it. 

Protection from surface drainage.-The spring mentioned above is 

located only a few inches above the bottom of the stream ehannel 

shown on the right of the view. When the picture was taken no 

water w&s flowing in the channel, but at times of rain considerable 

volumes of water deseend along the depression, eovering the spring 

and washing into it all sorts of refuse from the hillsides above. Plate 

VIII, A, shows another spring, located in Missouri, receiving the 

drainage from a cornfield, together with sueh manure or other fertilizer as may be used in the cultivation of the crops. This water, 

whieh carries both sulphur and Epsom salts, is considered of medicinal 

value, but it is clear that, situated as it is, its safety is at least doubtful. 

In general, it is not advisable to use springs for drinking water 

where their location normally exposes them to inflows of surface 

drainage. If other sourees are not available, however, the spring 

should be carefully protected by impervious walls, which should be 

carried to sufficient height to keep out the surface water. An 

example of a spring protected from all such sources of pollution is 

afforded by the Bowden lithia spring, at Austell, Ga., shown in 

Plate IX, A. 

Protection from wind blown and other refuse.-Another source of 

frequent and objectionable though not necessarily dangerous contamination is the leaves, paper, dust, and dirt blown into open 

springs by the wind. The spring shown in Plate IX, B, is a typical 

example of those surrounded by thick vegetation, and especially 
26 UNDERGROUND WATERS FOR FARM USE. 

liable to contamination by leaves and forest litter. An example of 

danger fr01n refuse of a more disgusting type is shown in Plate X, A. 

Located in the middle of a well-traveled street, only a t"ew inches 

above a gutter filled with paper and refuse, a part of which is sure 

to enter whenever a heavy rain occurs; open to the rain which 

washes into it from the steps leading down to it such dirt from the 

street as is brought in by the feet of the users; subject to the dipping 

of all sorts of n1ore or less dirty buckets and utensils; receiving the 

underground drainage and presumably more or less sewage from the 

buildings on the slopes above; and containing in its bottom several 

inches of decaying paper and other refuse, this spring is on the whole 

one of the worst and most dangerously located ·sources of drinking 

water in the United States. 

Protection from subsurface drainage.-In farming di~tricts pollution 

by subsurface drainage from buildings on the slopes above the springs 

is not very common, although many springs are located back of 

barns, below hogpens and outbuildings. The placing of buildings 

above springs intended for use should always be avoided, even if 

---------- --- -- - ---- --

------

---- ---- ~------------= -- --..::: 

FIGURE 13.-Diagram showing manner in which springs may be polluted by subsurface drainage. 

the spring is several hundred feet away from the proposed site. 

(See fig. 13.) 

Protecti,on of sink holes.-It has already been pointed out that 

much of the water in li1nestones, the springs of which are frequently 

used for drinking and domestic purposes, enters the rock through 

open sink holes, into which in some places manure and other refuse 

has been dumped or sewage drained. Plate VI, A, shows a small 

but continuous strea1n of sewage from a large college building discharging into a sink from which it finds its way to the underground 

water channels. Such practices are very dangerous. Cases of 

typhoid fever have resulted from drinking water from springs or 

wells which have become polluted by such matter entering the sinks; 

and even where specific pollution is absent, undesirable slimes and 

rubbish often render the water highly objectionable. Instead of 

discharging refuse or sewage into sinks, every care- should be taken 

to pro.tect them against its access. 

Use of lead pipes.-Spring water should always be conveyed by 

iron pipes, as lead, which was formerly much used, is more or less 
U. S. GEOLOGICAL SURVEY WAT ER- SUPPLY PAPER 255 PLATE X 

A. SPRING IN CENTER OF CITY STREET. 

B . DAIRY SPRING FRO M POL LUTED UND ERGROUND STREAM. 

POLL UTION OF SPR INGS. 
WELLS. 27 

readily dissolved by soft waters. Thousands of cases of lead poisoning resulted from such use in Europe and America before the cost 

of lead pipes became so high that they were largely abandoned. 

Where the water flows continually there is little danger frmn lead 

pipes, but if the flow is shut off when not in use, enough water should 

be drawn off each time to remove entirely that which has been 

standing in the pipes before taking any for domestic purposes or 

for the use of stock. 

Tests for pollution.-There is no infallible chemical test for the 

detection of pollution in small amounts. If a chemist is thoroughly 

familiar with the normal character of water in the immediate vicinity, 

he may be able to detect contamination by means of chmnical examinat~on; but waters contain so many harmless substances dissolved from the earth that the determinations by a chemist are 

often inconclusive. Careful observation of the spring itself and a 

common-sense inspection of its surroundings are usually of more 

value than an analysis. The spring should be protected from 

pollution, especially from surface drainage from houses, barns, 

hogpens, and other outhouses that are situated on the slopes above 

it within a distance of several hundred feet. When the absence of 

such local sources of pollution is established, the water should be 

carefully watched, especially in limestone regions, for muddiness or 

floating matter rising with the water after severe rains. Such phe-

~- nomena are evidence of connection with sink holes and indicate that 

the water is to be looked upon with grave suspicion if opportunity 

exists anywhere within miles for the entrance of polluting matter 

through sinks or otherwise. Plate X, B, shows a spring in Greene 

County, Mo., used for dairy purposes. The spring is remote from 

buildings and the water is clear, cold, and sparkling, but is, nevertheless, more or less polluted, owing to the fact that the underground stream feeding the spring appears at the surface at a number 

of points above it, crossing one or more highways and receiving the 

drainage from then1 and from a cemetery. 

WELLS. 

GENERAL DISCUSSION. 

Because of their cheapness, convenience, and fancied safety, wells 

are by far the most popular source of domestic supplies in all regions 

in which water is found at· reasonable depth. If properly located 

and constructed they afford an ideal source of supply fully justifying 

their popularity. But if they are, carelessly finished or improperly 

located they are much more liable to pollution than is commonly 

supposed, and it is with the view of pointing out some of the precautions that should be taken for their _protection,> as well as of 
28 UNDERGROUND WATERS FOR FARM USE. 

presenting information concerning desirable types, location, and construction, that the following discussion is presented. 

TYPES OF WELLS . 

.Although no two wells are exactly alike in all particulars, there 

are, in reality, only a few distinct forms, the others being simply 

modifications or combinations of these. (See Pl. XI-XV; figs. 

14-16.) The kind of well to be sunk at a particular locality depends 

mainly on the nature of the material to be encountered, one form 

being particularly adapted to a certain Inaterial, such as sand, while 

an entirely different form is demanded if rock is to be penetrated. 

The following tables show clearly and concisely the characteristics 

and methods of sinking the more common types and point out the 

conditions to which they are best adapted: 

Types of wells and conditions to which they are adapted. 

Type of well. Description. 

Dug.................... Generally circular excavations, 3 to 6 

feet in diameter, dug or blasted by hand and curbed with wood or with stones or bricks laid without cement. 

Bored .................. . 

Punched ............... . 

Driven .•••.............. 

California or stovepipe .. 

Standard drilled ...•.... 

Diamond-drill hole •..... 

Bored with various types of augers from 2 inches to 3 feet in diameter, 

rotated and lifted (together with the · earth) by hand or horsepower. Curbed with wood, cement, or tile 

sections, with open or cemented 

joints, and more rarely with iron 

tubing. 

Small holes, usually under 6 inches in 

diameter, sunk by hand or horsepower, by dropping a steel cylinder slit at the side so as to hold and lift 

material by its spring. Clay is 

added to incoherent materials like 

sand to bind them together so that 

they can be lifted. 

Small iron tubes, usually 1! to 4 inches 

in diameter and provided with point and screen, dnven downward by hand or by simple hand or horsepower apparatus. 

Overlapping sheet - steel casings, 4 

inches or more in diameter, forced 

downwards by hydraulic jacks and 

finally perforated by a special appa- ratus at water strata. Drillings are removed by a long sand-bucket with 

valve. 

Sunkbypercussionofheavy drill, 1~to 

12 inches or more in diameter, lifted 

and dropped from portable rig orderrick by horse or steam power. Cased 

with iron pipe in soft materials; usu- ally not cased in rock. Drillings re- moved by long bucket with valve in 

bottom. 

Sunk by rotating hollow bit, usually 1! to 4 inches in diameter, with rim 

fitted with black diamonds. Pene- trates by abrasion due to rotation. 

Drillings removed by water forced 

down drill and up along outside of 

rods. 

Conditions to which well is best 

adapted. 

Adapted to localities where the water is near the surface, especially where 

it occurs as small seeps in clayey ma- terials and requires extensive stor- age space for its conservation. Should not be near sources of pollution. Adapted to localities where the water is at slight or medium depths and to materials similar to those in which 

open wells are sunk. 

Adapted to clayey materials in which water occurs as seeps within 50 feet 

of surface, but not at much greater depths. 

Adapted to soft and fine materials; 

especially to sands and similar porous materials carrying considerable water at relatively slight depths. Particularly desirable where upper soil car- ries polluting matter. Adapted to soft materials extending to considerable depths and having sev- eral water strata capable of utilization. 

Can be used to advantage in all but the 

softest materials, but is particularly adapted to rock work, especially at great depths, being cheaper and 

quicker than other methods of drilling in rock. 

Not adapted to water wells because of 

great cost. Used where cores of mate- rials penetrated are required, or where 

hole Is sunk at an angle with she ver· tical. 
U. S. GEOLOGICAL SURVEY WATER-SUPPLY PAPER 255 PLATE XI 

A. OPEN DUG WELL. B. BORED WELL. 

TYPES OF WELLS. 
U. S. GEOLOGICAL. SURVEY WATER-SUPPL. Y PAPER 255 PLATE XJl 

A. THE JET OUTFIT. 

B. THE DRIVEN WELL. 

METHODS OF SINKING WELLS. 
U. S. GEOLOGICAL SURVEY WATER ·SUPPLY PAPER 256 PLATE XIII 

A. STANDARD PORTABLE RIG. 

B. ROTARY APPARATUS. 

METHODS OF SINKING WELLS. 
U. S. GEOLOGICAL SURVEY WATER-SUPPLY PAPER 255 PLATE XIV 

A. PITCHER PUMP. B. DEEP WELL PUMP. 

METHODS OF RAISING WATER. 
U, S. GEOLOGICAL SURVEY WAT ER-SUPPLY FAPER 255 PLATE XV 

A . WINDMILL. 

B. NATURAL FLOW. 

METHODS OF RAI SING WATER. 
FIGURE 15.-0utfit for sinking wells by jet 

process. 

FIGURE 14.-Common 

form of well auger. 

NG DRILL-PIPE 

II= AND CASING 

WALL OF EARTH 

ROTARY ~IT 

FIGURE !G.-Outfit for sinking wells by rotary process. 

29 
30 UNDERGROUND WATERS FOR FARM USE, 

Types of wells and conditions to whiCh they are adapted-Continued. 

Type of well. 

Wells sunk by calyx and 

steel-shot methods. 

Wells sunk by jet process. 

Wells sunk by hydraulic J)rocess. 

Wells sunk by hydraulic 

rotary process. 

Description. 

Sunk by rotation of notched steel shoe, or by chilled steel shot used in con- nectiOn with a rotating :plain shoe of 

soft iron. Rods by which power is 

transmitted are hollow and permit the dropping of the shot and the en- trance of water, which brings up the 

cuttings as with the diamond drill. 

Sunk by forcing water down small iron 

'"jet pipe" inside of casing, the water rising between the two with the 

drillings. Casing sinks by own weight or is forced down by jacks or otherwise. Diameter usually 2 to 4 inches. 

Sunk by lifting and dropping drill in 

hole full of water. Penetrates by percussion. Water and cuttings are forced into hollow rod on down 

stroke, being retained by valve. Di- ameter similar to standard drilled 

wells. 

Sunk by rotating steel shoe, as in calyx method, but with the difference that 

whole pipe is turned and water is 

forced down p~e and up outside instead of through rods. Steel shot 

also sometimes used. 

Conditions to which well is best 

adapted. 

Adapted to vertical work in hard tocks 

where cores are required. Cheaper but slower than diamond-drill meth- ~ 

oct; and more expensive than standard drilled holes. Is successfully used as an adjunct to hydraulic 

rotary process. 

Adapted to soft materials capable of being readily broken up by the water jet, especially to sands, etc., carrying considerable water at relatively slight depths. This method is an improve- ment over driven wells, which are adapted to same conditions, because 

it affords samples of materials pene- trated. Quick and fairly cheap and 

especially useful in sinking large numbers of test wells in adjacent localities. 

Adapted to clays and other unconsolidated deposits and to soft rocks where 

depths are moderate and the use of a heavy drill is not required. 

Adapted to rapid work at considerable 

depths in materials prevailingly soft, 

but having occasional hard layers. 

TYPES OF CURBS AND CASINGS. 

Just as there are various types of wells, so are there various methods of curbing and casing (or lining) the well, each method being 

likewise particularly adapted to a special type of well or to a certain 

definite kind of material. In some types of wells-for example, in 

dug, bored, and punched wells-several kinds of curbing or casing 

may be used, and the selection should be governed by the sanitary 

protection or resistance to the entrance of pollution which the casing 

affords. On no other single thing does the safety of the well depend 

to so great an extent as on the nature of the curbing or casing employed. 

The more common types of curbings and casings, their advantages 

and disadvantages, and the conditions to which they are best adapted 

are shown in the following tables: 

Types of well curbs and casings. 

Type. Nature. 

Rock .....•............. Broken or dressed rock laid without 

cement, usually in circle 3 to 6feet in 

diameter. 

Brick................... Porous brick laid without cement, 

usually in circles 3 to 6 feet in diame- ter. Cement-lined rock or Brick or stone as above, but laid in and _ brick. lined with cement. 

Conditions to which best adapted. 

Adapted to shallow dug wells, in mate- rials carrying water mainly as small 

seeps, where there is no near-by source of pollution. Same as rock curbs. 

Adapted to shallow-dug wells in mate- rials carrying enough water to permit an adequate supply to enter at the 

bottom. Can be used in polluted soils if the contamination is super- ficial and does not reach to the bot- tom. 
WELLS. 31 

Types of well curbs and casings-Continued. 

Tppe. Nature. 

Wood ................... Square wooden boxes in wells over 3 

feet in diameter; cylindrical curbs 

of narrow staves in wells under 3 feet 

in diameter. 

Tiles .................... Glazed sewer tile, cement tiles, and 

porous terra cotta tiles, laid without cement. Do.................. Glazed sewer tile and cement tile with 

cemented joints. 

Heavy iron casings ...... Iron pipes, 1 to 4 inches in diameter, 

with tight joints. 

Sheet-iron casings ....... Iron pipes 4 to 16 inches in diameter, 

with snug joints. 

Conditions to which best adapted. 

Can be placed in any shallow well, but are never safe and should never be 

used. 

Adapted to conditions similar to those 

of rock and brick curb. 

Same as cement-lined stone or brick 

curbs, except that it is more appli- cable to wells of small diameter. 

Adapted to wells of all depths in which water is obtained from a stratum below the casing, or from strata be- tween cased sections. Not adapted to strongly corrosive waters. Adapted to wells of all depths, in loose 

material, in which it is desired to pro- cure water from a number of strata. 

Summary of ad11antages and disadvantages of d~f!erent types of well curbs and casings. 

Type of curbing. Adv,antages. 

Rock ................... Allows all water to enter, thus utilizing all :>eeps. Material often costs little or nothing. As a rule requires little money outlay for labor. 

Brick ................... Where uncemented it allows all water 

Cement-lined rock or brick. 

to enter, utilizing all seeps. Filte.rs out most of sediment. 

Does not allow small animals to enter. Involves little money outlay for labor. 

Safe from pollution (except that enter- ing at bottom) as long as walls are not cracked. 

Prevents entrance of sediments. 

Prevents entrance of animals. 

Does not impart taste to water. 

Wood................... Cheap in many localities. 

Can be used in wells of very small di- ameter. 

Glazed and cemented 

tiles with uncemented 

joints. 

Does not taste of iron. 

Allows all water to enter, utilizing all 

seeps. 

Does not give taste to water. Does not require skilled labor. 

Disadvantages. 

Polluting matter enters readily and 

well is never safe if near sources of 

contamination. 

Affords no filtration and permits dirt 

and soil to enter. Permits entrance of mice and other 

small animals at top. 

Polluting matter enters readily, and 

well is never safe when near sources of contamination. 

Material costs considerable. 

Utilizes water from bot' om only. Is unsafe if so shallow that polluting matter can reach its bottom. 

Costs considerably more than unce- mented wells. 

May require skilled labor. 

Swells tight in wet ground, the water either entering at bottom or (after 

sudden rises) through shrunk portion at top. Pollution enters readily. Animals gnaw through. Wood rots, giving taste to water and 

favoring development of bacteria. 

Expensive in some localities. 

Polluting matter enters readily and well 

is never safe if near source of contamination. 

Soil may wash in through joints. Requires some outlay for material. 

Glazed and cement tiles 

with cemented joints. 

Safe from pollution (except that enter- Can be used only in soft materials con- ing at bottom) as long as joints are taining considerable water. tight. 

Does not require expensive labor. 

Iron casings. . . . . . . . . . . . . Adapted both to rock and to uncon- solidated materials. 

Safe from pollution except that enter- ing at bottom. 

The cost in large deep wells is considerhie. 

Practically limited to wells under 14 

inches in diameter. 

Is subject to deterioration by corrosion 

and incrustation in some places. Utilizes but one water stratum (except where perforated). 
32 UNDERGROUND WATERS FOR FARM USE. 

FACTORS GOVERNING SELECTION OF TYPE OF WELL. 

The type of well is the first and perhaps the most in1portant point 

to be decided. Of the many kinds in use, including the dug, bored, 

and driven types and wells sunk by the jet process or drilled by rotary 

or percussion rigs, each possesses, on the one hand, one or more points 

especially qualifying it for use under one or more of the many varying conditions encountered in drilling, and on the other hand, some 

disadvantage which may disqualify it for use under certain other conditions. The chief factors which govern the selection of typo are, 

usually, the amount of water needed, the character of the mat'- rials 

to be penetrated, the depth to which the well must be sunk, the cost 

of sinking the well, and the safety of the resulting supply. 1hese 

factors are considered in detail in the following paragraphs. 

YIELD OF WELLS OF VARIOUS TYPES. 

If an adequate supply of ground water is available, the yield nf a 

well will depend on the character of the water-bearing material, the 

facility of entrance of water, the size or storage capacity of the well, 

and the nature of the pumps. 

Character of the mater-ial.-The character of the water-bearing material is of the greatest importance in determining the yield of a well, 

as it is on the structure and texture of the water-bearing beds, that the 

amount of water which they will give up depends. A close-textured 

clay, for instance, 1nay hold as high as 45 per cent and a chalk as high 

as 53 per cent of its volume, while an open-textured sand may hold 

as little as 26 per cent of its volume. Notwithstanding this a sand 

will ordinarily yield large supplies, whereas a chalk and especially a 

clay will yield little or no water. In quicksands water is usually present in large amounts, but owing to the absence of good foundations 

for the curbing and the ready flow of the fine sand through the 

minutest crevices, ordinary dug wells in such material are generally 

out of the question and even driven wells equipped with the ordinary strainers usually soon become clogged. Driven or drilled wells 

equipped with special screens and sunk by experts familiar with the 

various methods of handling quicksand are usually the only types 

entirely successful in such material. 

Structures, such as solution passages, bedding planes, or joints, play 

an important part in determining the yield of a well. A solution passage in limestone may afford inexhaustible supplies where the mass 

of the rock is practically destitute of water. In· other rocks the bedding planes and joints may afford excellent supplies where no water 

is found in the rock itself. The amount of water present in the pores 

of different rocks is indicated by the following average porosities: 

Sandstones 15 per cent, shales 4 per cent, limestones 5 per cent, crys-
WELLS. 33 

talline rocks 2 per cent. The water present in the larger openings 

mentioned, though small in anwunt in comparison to that held in the 

pores, is yielded much more rapidly and, except in sandstones and 

similar porous rocks, usually affords the principal source of supply. 

Facility of entrance.-The facility with which water enters the well 

depends in part on the rock features enumerated and in part on the 

nature of the well. In loose materials water accumulates most easily 

in stone-curbed and similar types of dug wells and only less so in 

tightly curbed dug wells with open bottoms. Where the water bed 

is a strong one and the materials are sufficiently consolidated to prevent them from entering the well the water will freely enter an iron 

casing open at the bottom. In weak water beds in soft Inaterials, and 

in quicksands, either perforated casing~ or casings equipped with long 

screens are necessary to permit the entrance of the required amount 

of water. In many of the harder rocks the walls will stand without 

caving and casings are therefore unneccessary, the water entering at 

any point without hindrance. 

Storage capacity of wells.-Where strong water beds exist storage 

is unnecessary, the water entering from the rock as fast as the pumps 

demand. Where the supply is derived from weaker beds, especially 

those having only small seeps, storage is a significant factor and the 

type and size of the well are of great importance. The volume of 

tubular wells of equal depth varies with the square of their dian1eters, 

hence a 6-inch well will hold nine times as much water as a 2-inch well 

of the same depth, and a 3-foot well thirty-six times as much as a 

6-inch well. Dug wells are therefore of advantage in clays and siinilar materials where the water enters more slowly than it can be lifted 

by the pumps, for they permit accumulations that may tide over 

pe:r:iods in which the amount used is greater than the supply. For the 

deeper rock waters dug wells are impracticable and small-bore drilled 

wells Inust be used even where the supplies are slight. To get the best 

results the wells are generally made as large as can be afforded and 

sunk considerably below the point of entrance of the water, to afford 

the necessary storage. 

DEPTH OF THE WATER. 

The depth of the water is a factor of importance in the determination of the type of well to be sunk. A dug well, for instance, is suitable only when the water is within 30 or 40 feet of the surface, although many deeper dug wells exist. A punched well is commonly 

limited to depths of 50 feet, and a bored well is with difficulty carried 

to depths greater then 100 feet. Driven wells are most suitable at 

depths of less than 150 feet, although they are sometimes successfully 

extended to depths of 250 to 300 feet, or even to 400 or 500 feet or 

46449°-W s P 255-10----3 
34 UNDERGROUND WATERS FOR FARM USE. 

more, where the conditions are favorable. Jet wells are usually sunk 

only where it is not necessary to go much more than 100 feet from the 

surface. Wells of the California type are frequently extended to 

depths of 1,000, and occasionally to depths of 2,000 feet. IIydraulic 

rotary wells are successful to depths of 1,000 or 2,000 feet in the proper 

rocks. The percussion or churn drill n1ay be used for all depths down 

to 5,000 feet, or deeper if special outfits are provided. Diamond 

drills have been successfully used to depths of 6,000 feet. 

RELATIVE COST OF WE.LLS OF DIFFERENT TYPES. 

So many items, such as accessibility to fuel, cost of labor, trade 

combinations, knowledge of water conditions, relative availability 

of different drilling outfits, and local practice, enter into the eost of a 

well that few definite statements can be made. Instanees are not 

uneommon where wells of eertain types have been put down for onetenth the priee demanded for wells of the same type in other regions 

where conditions are essentially similar. In general, however, if only 

aetual outlay of money is eonsidered the dug well is the eheapest, for 

it may be eonstrueted by the owner himself at times when he has 

nothing else to do. Bored and driven wells do not require expensive 

rigs and are often eheaper than dug wells when paid labor is employed 

in their eonstruction. California wells for deep bores in soft materials 

are moderately eheap where the proper outfits are available, but 

unfortunately their use is as yet eonfined mainly to a single region. 

The jet proeess is adapted to the sinking of a large number of adjaeent 

wells in soft materials, espeeially sand, and is oeeasionally suecessful 

for single wells, although in 1nost places driven wells can be put down 

at less cost. The hydraulic and rotary ·processes n1ay be cheaper than 

straight drilling where there are numerous alternations of hard and 

soft material. Of the processes in use for drilling in rock the standard 

rig (percu~sion drill) is the cheapest, the calyx and diamond systems 

being generally used only when cores of the rocks penetrated are 

desired. A more detailed comparison of the methods is given in the 

subjoined table. Although the relative costs indicated are fairly constant over the country as a whole, the cost of any method in a particular loeality may be entirely abnormal, owing to the lack of drilling 

outfits capable of doing the work or to the existence of peculiar eonditions rendering its operation difficult. 
Formation. Diameter in 

inches. 

WELLS. 

Cost of wells. 

[By 0. E. Meinzer.] 

Looallty. I 

35 

Explanations. Cost per foot. 

Limestone ......... 6 .............. Illinois, Iowa, No casing required .......... 50 cents to $1. 

Minnesota, 

Wisconsin. 

Glacial drift and 2 .............. IowaandMinne- Heavyironcasingfurnished; 55centsto$0.75+. 

Cretaceous shale. sota. water guaranteed. Do ............. 4 ............ _ ...... do ............... do ..................... . $1±. 

Glacial drift ........ 4 to 6 ......... Illinois .......... Light casing furnished .... _. 50 cents or more. Do ............. Bored,6 to3t\..l Minnesota and Casing not furnished; planks 50 cents to $1+, inIowa. or tiles are used. These are expensive per foot, but 

the wells are not as deep as 

creasing w i t h 

depth. 

Glacial drift 

and Cretaceous 

shale (mostly soft 

shale). 

Clay, free from 

bowlders. 

Clay, sand, and 

gravel. 

Quartzite ......... . 

the drilled wells. 

li at bottom . ., South Dakota Casing furnished; flow of $350 to $500 for a artesian basin. clearwater guaranteed. well 900 to 1,000 

feet deep. 

~~~:~-~~~-f~~~: -~~~:~-::::::::::I ~::::::t.~~~~:~~~~~ ~ :::::: :~.:~:s~2, increas- 1 ing with depth. 

6. . . . . . . . . . . . . . Minnesota ....... ' No casing required; yield of $3 to $4. 

3 barrels an hour guaran- teed. 

Alluvium.......... 4 to 12.... . . . . California .. _.... Casing not furnished. Stove- 30 to 65 cents a foot 

pipe casing costs from 32 for 4 to 10 inch cents a foot for 4-inch 16- wells, for first 100 

gage pipe to $1.40 a foot for feet, with addi12-inch 10-gage pipe. tiona! charge of 

25 to 35 cents a foot for each additional 50 feet in 

depth. 

SAFETY OF WELLS. 

The safety of a well depends on the purity of the water at its source 

and on its protection against the entrance of contaminated waters 

and polluting solids. The type of well does not affect the purity of 

the original source; but if the water supply is primarily pure, its 

maintenance in that condition depends largely on construction that 

prevents contamination. 

Polluting matter finds entrance to wells in a variety of ways. In 

dug wells it enters through the crevices in the stone, brick, or wood 

curbing, or possibly through the brick itself; in bored wells it enters 

through the uncemented joints of the tiling or through cracks between 

the staves of tubular wooden curbing; and in drilled and driven 

wells through leaky joints or holes eaten in the iron casing by corrosive waters. By cementing the interior surfaces of stone or brick 

curbed wells, by replacing wood by cement or other impervious curbs, 

and by substituting new pipes for leaky iron casings the entrance of 

polluting matter through the walls can be prevented. Little or 

nothing enters the small tubular wells from the top and they may, 

therefore, be regarded as free from danger of pollution from this 

point. The larger open wells should be protected by a water-tight 

iron or cement cover standing somewhat above the level of the surrounding ground and tightly joined to the curb proper. The sloping 

of the earth away from the well serves ·to turn rainwater or pump 
36 UNDERGROUND WATERS FOR FARM USE. 

drippings away from it, so that little will penetrate, even if the curb 

becomes cracked by frost. 

A particularly dangerous type of well-the more so because of the 

fancied security of the owners-is the combination dug and drilled 

type. Because of a slight saving of expense, drilled wells are frequently sunk in old dug wells, the casing commonly beginning at the 

bottom of the old well. Although the water encountered by the 

deep well may be perfectly pure, it is liable to be contaminated, especially after rains, by the entrance of seepage waters into the open 

well and thence into the drilled well. The remedies are obvious; 

either the casing should be carried to the surface of the outside 

ground, or at least above the highest level ever reached by the water, 

or the open well should be converted into a water-tight cistern by the 

application of a thick coat of cen1ent over both sides and bottom. 

SUMMARY. 

The factors determining the desirability of wells of different types 

are concisely summarized in the following table, in which the first 

column shows the chief advantages of each type, while the second 

column shows the offsetting disadvantages. 

Summary of advantages and disadvantages of d1jferent types of wells. 

Advantages. 

Ease of construction; can be located, sunk, 

and cased by owner. Only hand power required. No outfit required. No expensive materials required for curbing. Cheapness in soft material. 

Ease of entrance of water. 

Utilization of all water strata. Utilization of small seeps. Quick response to rainfall. 

Large storage capacity. 

Accessibility for cleaning. 

Dug wells. 

Disadvantages. 

Limitation to soft materials; liability to caving while 

being dug. 

Costliness in hard rock. 

Wood curbing often used affords favorable conditions for 

the development of bacteria. 

Slight depth to which it can be sunk. 

Ease of entrance of polluting matter through and over top of curb. 

Water, not being replenished, is often stagnant. Fails frequently in time of drought. Must usually be at distance from house and from barns, 

privies, and cesspools to insure safety. Necessity for frequent cleaning; danger from gas while 

cleaning. 

Short life when curbed with wood. 

Ease of entrance of animals and refuse through open top. 

Bored wells (Iowa type, 1 to 3 feet in diameter, pervious curbing). 

Ease of construction; only hand or horse 

power required. No expensive materials required for curbing. Cheapness. 

Utilization of all water strata where curbed 

with uncemented tile. 

Utilization of small seeps. 

Quick response to rainfall 

Considerable storage capacity. Accessibility of larger types for cleaning. 

Slowness of method as compared with <_!riving. 

Special outfit required for all but small shallow holes. 

Limited to soft materials. 

Ease of entrance of polluting matter through curb and over top. Limitation of points of entrance of water to top and bot- tom with Jiillny wooden curbs. 

Wood curbs favor development of bacteria. 

Water, not being replenished, is often stagnant in larger 

bores. 

Failrues frequent in droughts. Necessity of location at distance from house to insure 

safety. 

Necessity of frequent cleaning; danger from gas while 

cleaning in the larger types. Limitation of practicable depth of large bores. 

Limitation of size. 

Short life when curbed with wood. 
WELLS. 37 

Summary of advantag~s and disadvantages of different types of wells-Continued. 

Bored wells (Arkansas type, 2 to 12 inches in diameter, tight casings). 

Advantages. 

Ease of construction; only hand or horse 

power usually required: skilled labor notes- l'ential in shallower holes. 

Cheapness for moderate depth. 

Deeper wells little affected by drought. Pollution shut out if properly cased. 

Gives good records of materials penetrated and water beds encountered. 

Disadvantages. 

Limitation to soft materials. 

Not adapted to very deep wells. 

Utilizes only one stratum in most pla(·es. Other disadvantages similar to those of drilled wells. 

Punched wells. 

Wben provided with pervious curbings the 

advantages are similar to those of open and 

Iowa type bored wells; when provided with 

tight casings the advantages are similar to those of the Arkansas type bored wells. 

Similar to those of open wells and the larger type of bored 

wells. 

Difficulty of operation; liability of crooked holes. 

Usual limitation to depths under 50 feet. 

Limitation to soft yet stitf materials, which are generally of local distribution. 

Driven wells. 

Ease of construction; often stmk in a few 

hours; only hand or horse power usually required. 

Outfit is inexpensive, can be quickly put up, and does not require skilled labor. 

Tubing is readily obtainable and inexpensive. Cheapness. 

Safety; can be located near sources of pollution if sunk through impervious bed preventing access of contaminating matter to water bed; 

nothing can enter at top. Permanency of supply as compared with dug wells. 

Cleaning seldom necessary as compared to open wells. 

Limitation to soft materials. 

Utilization of a single water stratum. 

Usual limitation to moderate depths. Restriction to open porous water beds due to absence of 

storage facilities. 

Slow response to rainfall as compared to many dug wells. 

Corrosion of pipes or well points. Incrustation of pipf's and well points. 

Entrance of quicksand through well points. 

Taste of water due to solution of the iron under certain 

conditions. 

Difficulty of cleaning in case of clogging. Short life as compared to some dug wells. 

Absence of information as to minor water beds or mate- rials penetrated. 

Stovepipe or California wells. 

Utilization of all horizons of water. Cheapness of casings as compared with large- sized driven or drilled wells. 

Shortness of sections, permitting use of steady 

pressure by hydraulic jacks. 

Adaptability to conditions where driving is 

impossible. 

Flush outer casings and absence of screw joints. Ready adjustment to strains. 

A voidance of clogging of perforations. Exclusion of sources of pollution. Affords fair records of materials and water beds 

encountered. 

Limitation to soft materials. 

Lack of strength of casing; distortion by lateral pressure; pulled with difficulty if distorted. 

Thinness of casing and shortness of life where waters are corrosive. 

Expensive; requires elaborate outfit available in only a few sections of country, skilled labor, etc. Cleaned with difficulty. 

Slight storage capacity. Taste of water due to solution of iron by corrosive waters. Short life under some conditions. 
38 UNDERGROUND WATERS FOR FARM USE. 

Summary of advantages and disadvantages of-different types of wells-Continued. 

StaBdard drilled wells. 

Advantages. 

Adapted to all rocks. 

No ordinarY: limitation as to depth. Can be readily deepened. Little affected by droughts. 

Can utilize all water strata where there is no great difference in head if casing is perforated, 

but this is rarely done. 

Pollution is completely shut out if properly 

cased. 

Can be located anywhere. 

Gives fair records of materials and water beds 

encountered. 

Disadvantages. 

Expensive; requires elaborate outfit, skilled labor, steam power with the attendant charges, and costly casing and pumps in deeper wells. 

Many difficulties in drilling; frequent losses of tools. 

Cleaned with difficulty. 

Slow response to rainfall; slight storage capacity. 

Corrosion of pipes and screens. 

Incrustation of pipes and screens. Entrance of sand through screens or clogging of screens. 

Taste of water due to solution of iron under certain con- ditions. 

Diamond-drill holes. 

Gives complete core of rocks penetrated. Can be drilled at any angle. 

Other advantages similar to those of other 

drilled wells. 

Adapted only to hard rocks. 

Requires costly outfit and materials, skilled labor, steam power, etc. Cost greater than drilled wells. 

Other disadvantages similar to those of drilled wells. 

Wells sunk by calyx and steel-shot method. 

Outfit and cost of sinking less than in diamond-drill holes. 

Readily used in connection with hydraulicrotary rig when hard rocks are encountered. 

Other advantages similar to those of drilled 

wells. 

Both outfit and cost of operation more than in drilled 

wells. 

Only vertical wells can be drilled. 

Slower than diamond drilling. 

Other disadvantages similar to those of drilled wells. 

Wells sunk by jet process. 

Rapid in soft materials; operates continuously. Cheap compared with hydraulic, hydraulic 

rotary, and drilling methods. 

Supplies inexpensive and readily obtainable. 

Adapted to incoherent materials, such as sand, not capable of standing alone. 

Affords fair records and samples of materials 

penetrated. 

Other advantages similar to those of driven 

wells. 

Limited to soft materials. 

Requires more apparatus than driven wells; requires skilled labor. 

Requires preyious supply of water. Small water seams not readily recognized. 

Draws from single water bed. 

Requires strong water beds due to absence of storage facilities; seeps can not be utilized. 

No storage capacity. Usually limited to small diameters. 

Satisfactory only in wells of moderate depth. Slow response to rainfall as compared to shallow-dug 

wells. 

Corrosion and incrustation of pipes. Taste of water due to soll:rtion of iron by corrosive waters. Difficulty of cleaning. 

Wells sunk by hydraulic process. 

Rapid in soft materials. Usually limited to relatively small diameters. 

Can be used where soft and hard beds alternate, Requires previous supply of water for drilling process. but works best in uniform materials. Pene- trates hard beds by fall of drill. 

Operation nearly continuous. 

Affords good records. Other disadvantages similar to those of drilled wells. 

Other advantages similar to those of drilled 

wells. 
OPEN OR DUG WELLS. 39 

Summary of advantages and disadvantages of different types of wells-Continued. 

Wells sunk by hydraulic rotary process. 

Advantages. Disadvantages. 

Very rapid in soft materials. Satisfactory only where the materials are prevailingly 

soft. 

Applicable to alternations of soft and hard 

material. 

Operations are relatively continuous; little 

lost time. 

Can penetrate hard beds by use of calyx appli- ance and chilled-steel shot. 

Small water seams not readily recognized; shut off by 

puddling by thick sludge. Requires previous supply of water for process of dnking 

well. 

Affords unsati.'lfactory records. 

I 

Possible for polluting matter to penetrate b.Y passage through loosened zone and casing. Other advantages similar to those of drilled 

1 

Other disadvantages similar to those of drilled wells. 

wells. 

OPEN OR DUG WELLS. 

LOCATION. 

The chief considerations in the location of open wells and wells 

in which pervious casings are used, in the order of importance usually 

ascribed to them by the owners, are: Cost, accessibility, convenience, 

and safety. The requirements, unfortunately, often conflict. Most 

houses and barns are located on elevations for the sake of good 

drainage, sightliness, or other considerations, but wells in such situations are rarely as cheap as the less convenient wells in the hollows. Again, convenience often demands that the well be located 

near the house, where slops are thrown upon the ground, in the 

vicinity of a cesspool or privy, or near the barnyard or hogpen, while 

safety demands its location on high ground at a considerable distance from these and other sources of poilu tion. . 

In cases of conflicting requirements it is usually the cost which 

eventually determines the location, or rather it is -the initial cost, for 

in many instances the final cost of a proper installation-if the cost 

of the resultant loss of health is considered-is n1uch less than that of 

an improper installation although the latter may not produce actual 

disease. 

A safe well is nearly always, in the long run, the cheapest, such a 

well being decidedly cheaper than the cost of medical attendance. 

· Safety should invariably be made the first consideration instead of 

the last. A well should never be put down in a doubtful situation, 

even as a temporary makeshift, for the owner almost always waits 

until too late before replacing it. 

SOURCES OF POLLUTION. 

Open or dug wells may be polluted by material seeping through 

the ground and curbing or entering fron1 the top of the well. Of the 

seepage m.aterials cesspools and privies are the most important source. 

Iu most localities the large amount of liquid reaching such recep-
40 UNDERGROUND WATERS FOR FARM USE. 

tacles is rapidly absorbed by the earth and becomes a part of the 

water body feeding the wells. Slops thrown on the surface likewise soak into the ground, and even if the liquid at first evaporates 

the residue is later taken up by the rain which sinks into the ground, 

and is carried downward to the ground-water body. The matter 

leached from hen yards, from hogpens, and frmn the manure piles 

near barns, eventually enters the ground and finds its way in one 

form or another to the ground water below. Drainage from nlanured fields and from pastures occupied by stock may also be a 

prominent source of pollution. Much of the polluted water from 

such sources is purified by passage through the ground and the danger 

of pollution of well waters by seepage is commonly exaggerated, yet 

gross carelessness in locations of wells near privies, cesspools, drainpipes and other filth receptacles is prevalent in many farm districts. 

One of the greatest sources of pollution for farm wells is the entrance of material at the top, and dug wells are especially liable to 

contamination of this sort, though other well types are not en,tirely 

exempt. Hill 

FIGURE 17.-Section showing relation of water table to surface irregularities. 

Of the material entering a well from the open top dust is an important source of contamination. It is always present in the air and the 

amount actually settling is very many times more than the conspicuous dust coatings collecting in buildings. In fact, in open wells, 

especially in regions where brisk winds are common, the accumulations sometimes amount to several inches in a year. Many wells 

which are cleaned only once in two years are found to contain as much 

as 6 inches of foul-smelling black muck, representing the dust and 

other refuse entering the well in that length of time. 

Small animals, such as toads, mice, moles, and snakes, fall into the 

well in times of drought when the sources of water they usually 

depend on have failed. 

Except that it keeps the larger animals out and is a convenience 

in using the well, the ordinary plank covering affords but little 

improvement over the open well. Crevices almost invariably exist 

through which the smaller animals may find access, and the dirt 

washed through the cracks by the pump drippings may be almost 

equal to that entering through an open top. · Moreover, it is a very 
OPEN OR DUG WELLS. 41 

dangerous type of dirt, as in many places it includes filth from 

domestic fowls and from the shoes of farm hands and others coming 

from manured fields, hogpens, or barnyards. . 

MOVEMENT OF GROUND WATER. 

When a well is carried downward in porous or semiporous materials, such as those in which most open wells are located, a level is 

soon reached, below which the ground is saturated with water (at 

least down to the first impervious stratum). This water body, or 

ground water, as it is called, has a definite upper surface, known as 

the water table, which conforms in general with the broader surface 

irregularities as shown in figure 17, but with the difference that the 

FIGURE 18.-Map showing position of water table by contours (continuous lines), lines of motion of ground 

water (arrows), and surface streams. 

section of the water table is flatter than that of the surface, being far 

below the ground on hilltops and eutting the surface in valleys. The 

motion of the ground water is in the direction of steepest slope of the 

water table, as illustrated in figure 18, and as this roughly coincides 

with the surface slope it follows that the direetion of motion of the 

ground water generally approximates that of the surfaee drainage. 

From the laws of occurrence thus outlined it appears that low 

points are the most favorable for obtaining water by open wells, as 

the water movements converge in that direction and the water table 

is nearer the surface there than elsewhere. Sewage, being to a large 

extent simply water to which a certain amount of foreign polluting 

matter has been added, follows the same laws of motion as the 

ground water, converging in an identieal manner toward the low 

spots, which are therefore points of danger where sources of contamination occur on the adjacent slopes. 
42 UNDERGROUND WATERS FOR FARM USE. 

"SAFETY DISTANCE." 

·By "safety distance" is meant the distance from a source of 

pollution at which a well may be sunk with a fair degree of safety. 

Some writers have spoken of a "cone of safety," by which is meant 

an inverted conical section of earth with its apex at the bottom of 

the well and its base a circle of some fixed radius on the surface. 

The radius taken by some is the depth of the well, by others twice 

the depth of the well, but such limits are usually fixed without taking 

into consideration the nature of ground-water movements or the 

character of the passages in which it n1oves. The distance of safety 

also depends to a considerable degree on the quantity and concentration of the pollution entering the ground water. Where coming 

from the surface the amount is commonly not large, but where 

entering at a considerable depth, as from cesspools sunk in limestone 

or in porous sands which also supply water to wells, it may reach the 

water stratum almost undiluted. It follows that no absolute radius 

can be laid down, each case demanding individual consideration. 

Certain generalizations, however, may be made as to conditions in 

materials of different types and under different topographic conditions, some of which are indicated below. 

Clay and till.-In ordinary clay and in the pebbly or bowlder clay 

known as "till" the water circulates in part by general seepage through 

the mass, in part through relatively thin -sandy layers, and in part 

along more or less open but irregular tubular passages. Seepage 

through the body of the clay or till is very slow and polluting matter 

is rarely carried for any great lateral distance; 100 feet from the 

nearest source of pollution may perhaps be regarded as a safe limit. 

The clay offers even more resistance to the passage of water directly 

downward, a 5-foot bed as a rule effectively shutting off polluting 

matter from the underlying water beds, unless such matter obtains 

access along the break made in sinking a well or other excavation. 

When the water follows sandy layers the movement, though much 

faster than in uniform clay, is nevertheless not very rapid, rarely 

exceeding a few feet per day, and pollution does not often extend 

much over 150 feet, 200 feet usually being a safe.distance. In open 

passages movement is much more rapid, and may-amount to several 

hundred feet a day in extreme cases. Under such conditions there 

is· no purification and relatively little dilution, and if the passage 

discharges into a well dangerous contamination may result. In a 

thickly inhabited region a well depending for its supply on passages 

of this nature is never safe. 

Sand.-A bed of sand is among the safer water beds. Being of an 

incoherent nature, the material rarely contains open passages, the 

water circulating in general by a slow movement among the grains. 
OPEN OR DUG WELLS. 43 

The rate, though sometimes amounting to 50 feet or more a day, is 

usually under 5 feet and may be under 1 foot. A well 200 feet from 

the nearest point of pollution is probably safe in fine and medium 

sands, but in coarse sands and gravel a much greater distance may 

be essential. 

Sandstone.-The movement of water in sandstone is in part through 

the body of the rock and in part through small open passages along 

the joint or bedding planes. Owing to the greater density of the 

rock resulting from the cementation of the grains the distance to 

which pollution may extend through th~ pores of the rock is less than 

- in sand, 100 feet usually being a safe distance. Probably even with 

the water moving along the joints and bedding planes 125 to 150 

feet from the source of pollution is a safe distance for a well. 

Slate and shale.-ln slate and shale the water follows in part the 

planes of stratification or bedding and in part the more or less vertical 

joints by which these rocks are usually cut. Unless certain of the 

layers are sandy the movement along the bedding planes is generally 

slow and pollution is carried for only short distances. The joints, 

however, are in many places fairly open and may conduct the water 

within a short time to considerable distances, possibly many hundred 

feet, like the granite joints described on page 15. However, unless 

the examination of the rock or the behavior of the drill in thewell 

shows the presence of such open joints, a well in slate or shale may 

usually be considered safe if not less than 100 feet from a source of 

pollution. 

Limestone.-The movement of water through limestone is almost 

entirely by means of open passages. Some of these are only a minute 

fraction of an inch in width, being no wider than joint and bedding 

planes. In such passages the movement of water is very slow and 

pollution is rarely carried far, 150 feet fron1 a possible source usually 

being a safe distance. Other passages, however, are of considerable 

size, perhaps many feet in diameter, and may extend for miles. One 

chamber in Mammoth Cave is nearly 10 miles long, and there is 

evidence that similar though perhaps smaller channels exist at 

numerous other points. . These openings are not uncommonly occupied by flowing streams which, if polluting matter is introduced,· 

may carry it for many miles. Such streams may have connection 

with surface sink holes. Corn~talks and other refuse from the surface 

not infrequently ·appear in wells drawing water from limestone, and 

the waters are often muddy after storms. Such occurrences are 

indications of surface contamination and the waters should be 

avoided if possible. 

Granite.-Practically no water passes through the body of granite, 

the movement being mainly along joint or fault planes or through 
44 UNDERGROUND WATERS FOR FARM USE. 

pore spaces in the disintegrated upper portions of weathered granite 

masses. Polluting matter may reach to considerable distances 

through joint or fault planes, as is indicated by the fact that the salt 

water of the ocean finds entrance to some wells located 500 feet, and 

in places even a_quarter of a mile or rnore, from the shore. It is said 

that in the deep public well sunk in granite at Atlanta, Ga., sufficient 

polluting matter entered through a joint struck at 1,160 feet from 

the surface to render the water unfit for drinking. 

PROTECTION. 

Protection from surface wash.-Many open wells are expos~cl to the 

same danger of pollution from surface wash as springs, and the same 

methods of protection should be used. A water-tight curb should be 

raised a few inches or a foot above the level of the surrounding surface and the earth banked around it, with a slope away from the well. 

This curb quickly deflects the water and prevents it from collecting 

and soaking through the ground into the well. 

Protection from stock.-The chief means in which wells become 

polluted by stock is through seepage from the surface. Watering 

troughs are commonly placed close to wells, and usually in such places 

the hoofs of the animals soon wear holes in which the rain water and 

more or less of the animal excrement collect and soak into the ground, 

finally reaching the well. To prevent this contamination the watering 

trough should be placed as far away from the well as possible, the 

water being conducted to it by pipes. A well in an open pasture, if 

it is to be used at all by hun1an beings for drinking water, should be 

surrounded by a fence at least 20 feet away. 

Protection from pump drippings.-The drip from pumps is a very 

common and dangerous source of pollution. In the greater proportion of dug wells provided with pumps the well is covered with 

boards or planks laid or nailed over the top. No matter how carefully these platforms are constructed cracks through which water 

can enter almost invariably exist, and it is a common occurrence to 

hav~ the water dropping or trickling back into the well whenever 

any is spilled in pumping. The danger of this will be understood 

when it is recalled that those stepping upon the platform to pump 

may have just come from the barnyard or from manured fields, 

bringing with them on their shoes more or less filth, part of which 

is left on the planking and washed into the well by dripping water 

from the pump or by the next rain. The wooden platform should 

be replaced by a water-tight cover made of iron, cement, or other 

impervious material. Cement covers are coming into use in many 

localities and afford ideal protection. 

Protection from small animals.-An ever-present cause of pollution in open wells and wells· insufficiently protected by coverings is 
DEEP WELLS. 45 

the entrance of small animals. It is a common thing for snakes, 

toads, mice, and even rabbits to penetrate through crevices and to 

fall into the well, especially in dry seasons when the animals are compelled to make desperate atte~pts to reach water. The remedy is 

an impervious well cover fitted tightly to the curb. 

Protection from dust.-Dust is usually less dangerous than other 

sources of pollution, but in dry seasons, when dirt from the street or 

bar:oyard is being blown about, it may become of considerable amount 

and danger. It is not uncommon to find several inches of black, foulsmelling silt in the bottom of a well on cleaning, evep.t;~.att~i~may 

have been cleaned only a year or two before. The dust may be kept 

out by water-tight coverings such as are used to keep out pump 

drippings. 

INCREASING THE YIELD. 

The methods of increasing the yield of wells vary according to 

whether the well is of the dug or drilled type and whether the existing supply has or has not ·materially deereased from the original 

supply. .An originally inadequate yield commonly results from 

insufficient supplies in the water- bearing rock or from the slowness 

with which the supplies are given up. A decreased yield may be 

due to some defect in the well itself. 

Remedy for insufficient supplies.-Ordinary clay· and the denser 

varieties of pebbly and bowlder clay or till usually contain but little 

water, and this little is often largely in the form of interstitial water 

held in the body of the material and given up slowly to a well by 

general seepage. Under sueh conditions the amount entering the 

well is often more or less proportional to the area of surface exposed 

in the wall. This area varies with the diameter of the well; thus, 

three times as much surface will be exposed in a given height of wall 

in a 6-inch well as in a 2-inch well and six times as much in a 3..:foot 

as in a 6-inch well. To give a large yield a large·-diameter well is 

very desirable in materials of the character mentioned. 

Large wells are also desirable in rocks in which the water occurs 

in a similar manner-that is, in pores rather than in open passages. 

In general, however, if water is yielded at all by the rocks, it is given 

up more readily than by clays, hence a large bore is less necessary 

This is fortunate, for the range of size in rock wells is usually rather 

scant, owing to the fact that most rock wells are of the drilled type. 

Where the water occurs in bedding or joint planes the diameter is 

of still less importance, as the entrance of the water is localized and 

is relatively free. Large diameters, nevertheless, increase materially 

the likelihood of striking an opening. · In the oil regions the increase 

of the diameter of a bore 2 inches by reaming has been known to 

open pools not encountered in the original hole, and a similar result 

is possible in water wells. 
46 UNDERGROUND WATERS FOR FARM USE. 

The depth of dug wells in material in which the amount of water 

is relatively small is also important, for increase in depth increases 

the storage space in which the water can collect during periods when 

the well is not in use, thereby greatly adding to its total capacity. 

In many regions, owing to the removal of the forests and the construction of drainage ditches, the water-, from rainfall and snowfall 

runs off more rapidly than formerly and much less sinks into the 

ground. As a result the ground-water level has been lowered .pver 

large areas and wells which once afforded good supplies are now dry. 

In many places there is still plenty of water in the ground, the only 

difference being that its level has sunk below the bottom of the well. 

In such places the deepening of the well brings complete relief. 

Gleaning the well.-In the course of time an accumulation of material 

entering the well as dust at the top, or washed in through the ground, 

forms considerable amounts of silt in the bottom and on the sides. 

In some wells this deposit is sufficient to hinder, to a certain extent, 

the entrance of water into the well and to lessen its storage capacity. 

Some relief is usually afforded by cleaning out the well. 

DEEP WELLS. 

Depth is one of the most important factors to be considered in 

sinking a well. On it both the type and the location often depend. 

The benefits which the owner expects to realize from a deep well as 

compared to a shallow well are (I) larger supply, (2) higher head, 

and (3) purer water. 

LOCATION. 

In the location of deep wells the chief consideration is the obtaining 

of a supply, slight differences in location seldom seriously affecting 

the cost, while the prevailing use of casing in soft deposits insures 

safety from ordinary sources of pollution. The occurrence of deep 

waters depends on the character and structure of the rocks far 

below the surface. No indications of these features are usually 

found at the surface, and the well may as a rule be located independently of surface relief, though where artesian flows are expected 

the well should be located on as low ground as possible. Information 

as to the best location for a deep well may often be obtained from 

a careful study of the records of wells in adjacent regions, which 

can be made by the more experienced and intelligent drillers, or from 

a study of the rocks and their structure, which often requires the 

services of a trained geologist. 

GENERAL RELATIONS. 

RELATION OF SUPPLY TO DEPTH. 

It is a widespread, in fact an almost universal belief that the amount 

of water increases with depth and that water may be had anywhere 

if one only "goes deep enough." This is, however, far from the 
DEEP WELLS. 47 

truth. Rainfall appears to be the source of at least 99 per cent of 

the fresh water found in the ground, the remainder being water 

included in the rocks at the time of their accumulation beneath the 

sea, together with a small amount derived from volcanic sources. 

As would be expected froin its atmospheric source, water actually 

decreases rather than increases in amount with depth, a great many 

rocks encountered by the deeper wells and mines, especially at depths 

below 1,000 feet, being entirely destitute of water. a 

However, if only the more superficial portion of the crust is considered, there is in general an increase of water with depth. Except 

in valley bottoms and. other depressions the surface soil and rocks, 

although carrying much moisture, are rarely saturated; but at depths 

which vary, according to climate, soils, and topography, from a few 

to several hundred feet, a saturated zone constituting the groundwater body is encountered. Wells starting anywhere above drainage 

level will in general encounter water in increasing arnounts at least 

down to the drainage level. Again, the surface beds may be of nonporous nature and may therefore be destitute of water, while the 

underlying beds, if porous and below drainage level, are likely to be 

saturated. 

Of course there is a constant tendency for the surface waters to 

penetrate downward and fill the porous rocks below. That these are 

at present destitute of water may be due, at least in certain rugged 

regions, to the draining of the deeper and in places relatively porous 

beds by deep valleys. Elsewhere, and this is doubtless the most 

common cause, the water is kept from percolating downward by 

impervious beds near the surface. The deeper rocks are largely of 

the granitic type and hold but little water. Except where they 

constitute the surface rock and are somewhat broken by joints it 

is of little use to penetrate them in search of water. 

To speak broadly, it may be said that there is no general increase 

of water with depth and that the finding of deep supplies is entirely 

dependent on local geologic conditions. Unless there is some proof 

that deep water-bearing beds exist, the sinking of a deep well should 

be regarded wholly in the light of an experiment, although in sedimentary rocks it has the decided advantage that it may penetrate a 

number of water strata, which may afford in the aggregate a fair 

supply where a single stratum might not suffice. 

RELATION OF HEAD TO DEPTH. 

As with regard to volume, there is a general belief that the head 

of water increases progressively with depth. This belief has a better 

basis than the other, for in some places such a relation of head to 

a Fuller, M. L., Total amount offree water in the earth's crust: Water-Supply Paper U.S. Geol. Survey 

No.l60, 1906, pp. 64-70. 
48 UNDERGROUND WATERS FOR FARM USE. 

depth exists, as in the artesian system shown in figure 19, in which 

the deeper beds outcrop at successively higher levels. 

The reverse condition is shown in figure 20. Such conditions are 

not the result of universally prevalent structures, although it is perhaps more common than otherwise that ·the strata are higher at the 

rims than they are at the centers of the great structural troughs. 

In many structural basins, the outcropping beds of the rims in fact 

lie high up on the flanks of mountains, while the beds of the center 

constitute low plains. 

RELATION OF QUALITY TO DEPTH. 

Another prevailing idea is that the deeper wat6rs a:re purer. 

Within limitations this is generally true as regards the :shallower 

waters, which, being close to the surface and without the protection 

afforded by overlying clays or other impervious beds, are susceptible 

to pollution. Deeper waters, on the other hand, are almost always 

overlain by relatively impervious beds that serve to keep out polluting 

J1' -------------------------=~~~~~~~-~~=~J!T ____________ _ 

FIGURE 19.-Artesian system showing progressively higher outcrop of deeper beds. 

FIGURE 20.-Artesian system showing progressively lower outcrop of deeper beds. 

materials, and as a rule they are entirely safe. In many places, however, the amount of mineral matter dissolved in the water shows a 

general increase with depth, the amount in deep waters averaging 

several times that in surface waters, which are largely made up of 

recent rainfall. There are sOine exceptions to this law, due mainly 

to variations in the character of the materials in which the waters 

are found, the waters in a calcareous glacial drift or in an alkaline 

flat, for instance, often being very n1uch harder than those in underlying beds. Limestone waters, too, are generally harder than sandstone waters. The maxim of certain drillers, "The harder the rock 

the harder the water," is based on the prevailing softness of the 

sandstones in many districts as compared to the hardness of the 

limestones. 

In addition to the impervious bed~ mentioned, the casing plays an 

important part in preventing the access of pollution to deep waters. 

When the casing has been corroded, pollution from sources near the 

surface is often admitted through the minute holes eaten in the iron, 

spoiling the deep waters. \Vhere the casing does not entirely fill the 
U. S. GEOLOGICAL SURVEY 

A. DRILLED WELL WITH OPENING BETWEEN OUTER CASING AND PUMP TUBE UNPROTECTED. 

B. DRI LLED WELL WITH OPENING AROUND CASING PROTECTED BY CEMENT. 

PROTECTION OF WELLS. 
DEEP WELLS. 49 

hole, contamination may pass down outside of it, while in uncased 

rock wells pollution may enter through any of the numerous fissures 

that usually exist in the upper part of the rocks. Even in such 

wells, however, the danger of contamination decreases rapidly with 

depth. 

SUMMARY OF CONCLUSIONS AS TO DEPTH. 

Contrary to the common belief, there is no general increase in the 

volume of underground water with increase in depth, such gain in 

volume as is occasionally found being due to peculiar local conditions: Neither is there a universal increase of head, although it may 

happen because the lower beds outcrop at higher altitudes than the 

upper ones (fig. 19). The deeper waters, however, are generally 

purer than those near the surface,· although their mineral content 

is likely to be higher. 

PROTECTION OF WELLS. 

NONFLOWING WELLS. 

Many of the conditions favorable to pollution of the shallow wells 

likewise favor the contamination of deep wells, but as the causes and 

remedies have already been 

discussed, especially in connection with the section on 

"Safety distance" (pp. 42-44) 

they do not require further consideration at this point. 

The water of deep wells when 

first encountered is usually safe 

and rightfully has a good reputation, so that people often go 

to great expense in drilling for 

deep rock waters. Unfortunately, however, many fail to realize that unless care is taken, 

it is possible for deep wells 

Sod Ul 

10 

u 

Soil 

to become polluted by the en- FIGURE 21.-Diagram showing danger of pollution 

where casing is carried only to rock. 

trance of surface waters. In 

regions where the rock is within a few feet of the surface, for instance, 

the casing may be carried only to the rock, the fact that pollution 

can enter the well through the rock crevices being entirely overlooked. (See fig. 21.) The chief precaution necessary aga~nst this 

danger is to carry the casing to a sufficient depth to shut off all 

surface waters entering through fissures. It is hard to say. how 

deep it must be carried to remove all danger of contamination, but 

the crevices are usually limited to the upper part of the rock (fig. 21), 

46449°-w s P 255-10-4 
50 UNDERGROUND WATERS FOR FARM USE. 

and every additional foot of casing gives additional safety. Ten 

feet of casing in the rock would materi·ally reduce the danger, while 

25 feet would in most wells probably insure safety. The best 

plan, however, is to carry the casing from the surface down to the 

water-bearing seam. The casing should always be set with a tight 

joint at the bottom to prevent the entrance into the well of surface 

waters that find their way downward along the outside of the pipe. 

Again, it is not unusual to drill new wells in the bottom of old dug 

wells and to allow the polluted surface waters to mingle with the pure 

rock waters. 

Many towns situated on rock surfaces and using unprotected wells 

of the type mentioned have been visited by epidemics of typhoid 

fever, cholera, and other diseases, leading to the loss of many lives. 

Another source of pollution, less common and possibly Jess dangerous than the preceding, arises from the fact that many casings 

are left open at the top, even when care has been taken to carry 

them to proper depths. Plate XVI, A, shows a good example of 

this kind, there being a considerable open space between the outer 

casing and the inner pump tube through which small animals and 

various kinds of dirt find access to the water below. Plate XVI, B, 

shows a casing properly protected, all openings being hermetically 

sealed by cement. 

A fourth and very common means of contamination of deep wells 

is by leaks in the casing due to imperfect joints or to corrosion. The 

process of corrosion may be very r:apid, the pipe in some wells with 

acid chalybeate waters lasting only a few years. No one expects a 

pipe laid in the ground near the surface to last many years, yet many 

seem to think that a well casing will last indefinitely. Unfortunately, this is far fron1 true. 

The detection of leaks is somewhat difficult. In some wells, 

however, water may be heard trickling in or may be seen by a light 

ray projected down the well by a mirror when the pump is withdrawn. The admixture of water from outside sources may sometimes be detected by a difference of the hardness of the well water, 

by an earthy taste or taste of decayed vegetation, or by a cloudiness 

due to silt brought in by superficial waters. · 

The remedy is usually to pull the old casing and replace it by a 

new one, the length of time the pipe is allowed· to remain before 

replacement being determined by an estimate of its life based on 

the action of the water on the pump tube or other pipes. An alternative treatment sometimes employed when the leak is near thesurface is to set a packer designed for the purpose in the space 

between the bottom of the pump tube and the casing and fill the 

space above with cement. 
DEEP WELLS. 51 

FLOWING WELLS. 

In order that water may have sufficient head to flow out upon 

the surface it must be confined under some impervious or relatively 

impervious clay or other bed. This effectually shuts out pollution 

fr~m the overlying material, and any contamination that reaches 

the well must be transmitted laterally for relatively long distances. 

As pollution rarely extends through the ground to any great lateral 

distance from its source, it follows that artesian waters are almost never 

polluted. 

In artesian wells the water, being under greater head than that in 

the surrounding materials, will pass outward thro gh any leak that 

may develop rather than admit the water of lower head to the well. 

Suction, such as is developed in the Richards ap aratus in laboratories, which might be conceived as drawing in outs de water through 

openings in the casings, can not take place with he relatively low 

velocities of the water in the ordinary artesian 'Well . Even in a well 

in which the water has a very high velocity, the s ction is so slight 

in proportion to the immense volume discharged t at it may usually 

be neglected 

INCREASING THE YIELD. 

METHODS OF INCREASING ORIGINAL YIEL 

Shooting.-The practice of "shooting" -explo ling a charge of 

nitroglycerine or other explosive in a well-has Ion been successfully 

employed i;n the oil regions. and has in late 

years been used to increase the flow of 

water wells, in which dynamite is more 

commonly used. The action of the _dyna-· 

mite is to shatter the surrounding rock, 

with the result that connection is frequently established with other crevices, in 

some wells largely increasing the water 

supply. (See fig. 22.) The dynamite is FIGURE22.-Diagramshowingloosenin effect of shooting wells. 

most effective in hard, brittle rocks, such 

as limestone, which are as a rule completely shat ered by the explosion, and is least effective in soft tough shales, hich are bent and 

compressed rather than broken. 

Steam jet.-Shooting, owing to the character f the materials, is 

not usually: practiced in unconsolidated deposits, n which the steam 

jet is sometimes used instead of dynamite. T e steam is forced 

down a small pipe inside of a larger one and comin into contact with 

the water at the bottom turns it quickly into s earn, the resulting 

explosion loosening the material or making a pock t about the bottom 

of the pipe. Where the materials are dense and c ayey, the action of 

the steam jet may considerably increase the infl x of water; in the 

more porous deposits it has less effect. 
52 UNDERGROUND WATERS FOR FARM USE. 

Packing with gravel· or sand.-It frequently happens that where 

the material is very fine it packs around the well so as to hinder 

the entrance of water. In such cases 

it is a common practice to drop a supply of pebbles into the well and with 

the aid of a drill force them out into the 

surrounding clay, etc., until a pocket of 

pebbles is produced through which the 

water flows freely to the well. 

In quicksands, the space between 

the outer casing and the pump tube 

and strainer is often filled with sand 

through the heavy suction induced by 

pumping. This sand in many wells 

keeps back the quicksand while allowing the water to pass through it freely 

and to enter the well. (See fig. 23.) 

Production of sand or other pockets 

by pumping.-Many of the materials 

yielding water to wells consist of nlh:-

FmuRE23.-Diagram showing formation tures of sand or gravel and day. 

of sand pacl'ing through pumping. 1 • 11 · · By heavi y pumpmg a new we It IS 

often possible to remove the fine clayey material, leaving the sand 

grains and pebbles in a sort of pocket about the well (fig. 24), the 

result being much like that produced by the 

artificial gravel pocket described in the preceding section. A similar method is employed in certain stiff clays, in which small 

open pockets at the botton1 of the well are 

appa~ently produced by the heavy pumping. 

METHODS OF RESTORING LOST SUPPLIES. 

(J) 

>. 

([J 

I.. 

'00 

.c 

+-

-~ 

"'0 -~---l 1---(J) 

When a deep well is first sunk, it usually =---=-· - --5 

gives good supplies, but as time elapses the _=-g_ 1- -= 

yield is found to decrease gradually until ::=:. -= - - - -==- (J) =--=-

finally it is but a small fraction of its origi- __ ~ -=-~ ~-= 

nt ~lbamt odutnt. dThis dec~eatshe is comm

1

only a

1

t- = _J'\ ~t~~ = 

ri u e o a ecrease In e genera supp y =-----==~~\)()~§~If,_--=-.: 

of the region or to the drawing off of the ? · _ _Ao~~~t ~ 

water by newer and better wells. In Inany =---= -==---=. -= 

wells this is a real cause, but in others the FIGURE 24.-Diagramshowingadfailure is due rather to the deterioration vantages of packing with sand 

of the old well than to the losses caused and gravel. 

by new wells, which in reality have a large yield simply because they 

are new and in good condition. The chief causes of decrease or 

failure are clogging of the screen, entrance of sand, and leakage. 
u. S. GEOLOGICAL SURVEY WATER-SUPPLY PAPER 255 PLATE XVII 

A. WELL POINTS. 

B. PULLING PIPE WITH JACK. 
DEEP WELLS. 53 

Rescreening the well.-Of the causes of failure enumerated the 

clogging of the screen or strain~r is probably the most common. 

This may result from the filling of the perforations by sand and silt 

sucked· in with the water, but other very common causes are the 

closing of the pores by the deposition of iron or lime. Where the 

waters carry acids in solution, the screen is often attacked 

and corroded, the iron set free being redeposited in the 

sand about the screen, forming thick, impervious coatings 

of a sort of sandstone which sooner or later effectually 

shuts off the water. 

When the matter collected about the well point is soft 

and loose, it can often be removed by back pressure 

produced by pumping heavily into the well, the outward current forcing back the accumulated silts. \Vhen 

FIGURE 26.-

this fails, the usual remedy is to pull the 

casing and screen, or the pump and well 

point, and replace it by a new one. (See 

Pl. XVII.) 

Prevent,ion of the entrance of sand.-If a well 

is not properly constructed or screened, sand 

or quicksand may enter the well in large quantities and greatly hinder the entrance of water. F~C::~ ·~ 

In some wells this is re1nedied by substituting wen showa finer screen, and in others by packing gravel ing loss by leakage into 

about the bottom of the well, or around the the superfiscreen or strainer, as already described. The cial depos- its. (After 

packing of sand about the strainer has enabled Cham hermany wells to draw on quicksands that ordi- lin.) 

narily would have almost imtnediately choked and ruined 

the wells. 

Prevention of leakage.-Leakage in wells affording acid 

Section of • 1 h · b · l wen show- waters 1s very preva ent, t e ptpes ecomtng rapid y corroded until holes appear in their walls through which 

the water from the well may escape. The only way to 

prevent leakage of this type is to recase the well. 

ing loss by 

leakage 

from one 

deep bed 

into another. (After 

Chamberlin.) 

In uncased wells there is much leakage into other nonsaturated beds, as is clearly shown by the accompanying 

diagrams (figs. 25 and 26). Figure 25 shows the water 

from two deep-lying beds being lost into one near the surface, and 

figure 26 shows a loss from one deep bed into another. The remedy 

for either condition is to carry the casing down to the principal 

water bed and not try to. draw on two beds of different heads. 
54 UNDERGROUND WATERS FOR FARM USE. 

CISTERNS. 

The ordinary cistern is an excavation in the ground, usually circular in shape, lined with a supposedly impervious coating of cement or 

other material, and used for the storage of rain water. Cisterns are 

used chiefly where the supply of well water is insufficient or its quality 

o bj ectiona ble. 

ADVANTAGES OF CISTERNS. 

Supplementary supplies.-In many of the best farming regions of 

the country, as in the Blue Grass region of Kentucky and elsewhere, 

the rocks either carry so little water or carry it so irregularly that 

many wells fail to obtain a sufficient supply to meet domestic needs 

and the demands of stock. In shaly regions the water supplies are 

even more uncertain and it is oft~n impossible to procure the necessary supplies from wells. This is true also of many areas underlain 

by clay and of some areas characterized by thick beds of clayey till. 

In all these regions supple1nentary supplies of water are necessary, at 

least for stock, and where springs, ponds, or lakes are not available 

cisterns must be resorted to, and in some places they are necessary 

even for domestic supplies. 

Softer and fresher water.-Rain water is the softest of all natural 

waters, hence is very desirable for washing and other domestic purposes, especially in limestone regions, where the water of many wells 

or springs is so hard that soap, instead of dissolving and making a 

good lather, forms a dirty-looking curdle or scum on the surface. 

In such regions much trouble is also caused by the formation of 

thick crusts of lime and n1agnesia on the inside of the kettles and 

other utensils and by the precipitation of the white, milky sediment 

which clouds the water when it has been boiled. In other regions, 

as in the Atlantic Coastal Plain, the water may be highly charged 

with soda, with the result that rice or other white foods cooked in 

it are turned a dirty yellow. Elsewhere, especially on low sandy 

beaches and the keys of our limestone coasts, the well water is 

brackish and unfit for drinking. All these difficulties are avoided 

if soft cistern water derived frmn the collection of the rain water 

is available. 

Safety.-It is usually in1possible for pollution to enter a properly 

constructed cistern-one in which the lining is water-tight-through 

the walls, and with a little care and by providing water-tight covers 

it is possible to keep out much of the undesirable matter from the 

top. Of course more or less dirt may be washed from the roof into 

the cistern, but the first run-off can be allowed to waste either by 

some automatic appliance or by hand, letting only the later and 

relatively pure water enter the cistern. A cistern, therefore, if properly made and cared for, is to be regarded as a practically safe source 
CISTERNS. 55 

of supply. It is certainly far safer than the ordinary dug, bored, and 

punched well, and even than many of the shallower driven wells. 

Oonvenience.-Another great advantage of a cistern is its convenience. As they are built near or even under a house, dairy, or barn, 

the water may often be pumped directly from them to the sink or to 

the dairy or wafering trough. 

Ease of cleaning.-Because of their shallowness and the smoothness of their walls cisterns can be mueh n1ore quickly and thoroughly 

cleaned than wells. Consequently they are usually cleaned more 

frequently and the water is kept in better condition. 

DISADVANTAGES OF CISTERNS. 

Contamination by dirt from roof-The dirt frmn the roofs is very 

objectionable, including dust blown from barnyards and highways, 

the droppings of birds, etc. The remedy is, as already stated, to 

allow only that portion of the water falling during the latter part of 

a shower, after the dirt from the roof has been largely removed, to 

enter the cistern. 

Liability to crack and admit pollution.-The greatest disadvantage 

of a cistern and one which subjects the users to grave danger is the 

liability to crack. No matter how good the cement used in. the 

construction or how careful the workmanship, eracks are liable to 

develop and admit shallow and possibly polluted ground waters. It 

is to the waters entering in this way that the notable hardness often 

indieated in eistern waters is due. Cistern water under normal conditions is soft, and if it becomes hard it is a sure- indieation that 

ground water has in some way found aecess to the cistern. It is a 

danger signal which should not be disregarded, and whenever it Is 

noted the cistern should be e1nptied and repaired at onee. 

CONDITIONS UNDER WHICH CISTERNS ARE DESIRABLE. 

Cisterns are desirable (1) wherever the ro~k, clay, or other materials in which the well is sunk are poor water bearers; (2) wherever 

the ground water is too hard for washing, too alkaline for cooking, or 

too braekish for drinking; and (3) wherever waters from other sources 

are inherently unsafe. They are especially desirable in the larger 

towns where the houses are crowded and the wells often polluted, and 

where no public supply is available. Again, on farms, where wells 

are not infrequently located near barns or other sources of pollution, 

cisterns often constitut~ the only safe source of water. 

SIZE. 

The ordinary cistern, usually 5 or 6 feet in width and 10 or 12 feet 

deep, almost invariably fails to meet the demands on it during 

extended periods of drought. To insure a supply which can always 
56 UNDERGROUND WATERS FOR FARM USE. 

be depended on either for domestic or for stock use, much larger 

cisterns are necessary. 

If rainfall were equally distributed throughout the year and if the 

consumption of water were regular, a cistern large enough to hold one 

or two months' supply would be sufficient, but, unfortunately, the rainfall is ordinarily very irregular, from one-half to two-thirds of the 

entire precipitation of the year not infrequently falling in three or 

four of the colder months, while the remainder is distributed over the 

eight or nine warmer months. This reason alone would make large 

cisterns desirable, but still another reason is foum:l in the larger consumption of water in the warmer season, which is generally the period 

of deficient rainfall. To be sure of a supply through long periods of 

drought such as are likely to occur one or more times in each decade, 

it is necessary to have a cistern that will hold when full two-thirds 

or three-fourths of the total amount required during the year. For 

drinking, cooking, and washing each person on a farm ordinarily uses 

from 5 to 10 gallons or more of water a day, and each head of stock 

ordinarily requires from 6 to 15 gallons. The amount used, however, 

depends so largely on local conditions that it should be carefully 

ascertained in each specific case before the size of a cistern is determined. An allow,ance of 20 to 35 per cent should also be made for loss 

due to the deflection of the earlier and more or less dirty washings 

from the roof, the overflow of gutters in heavy storms, the· loss by 

snow sliding or blowing from the roof, the leakage of pipes, and 

other minor causes. The total amount needed and the allowance for 

loss having been determined, it becomes possible to calculate the size 

of cistern required. The volume of a round cistern is approximately 

five-sixths of the product obtained by multiplying the square of the 

diameter by the depth. 

For assistance in determining the amount of water annually falling 

on a roof the following table, showing the number of gallons falling 

on each square foot on roofs of gentle, medium1 and steep slope at 

different rates of rainfall, is presented. The annual rainfall of any 

particular locality can be ascertained from the United States Weather 

Bureau. 

Amount of water falling annually on roofs of varying slopes at different rates of rainfall. 

Slope of roof. Water falling on roof, in gallons per square foot, when annual rainfall, in inches, isRatio 

Degrees. (vertical 

to hori- 15 20 25 30 35 40 45 50 55 60 zontal). 

--------------------------.--

45 1 1:1 6.6 8.8 11.0 13.2 15.4 17.6 19.8 22.0 24.2 26.4 26, 1:2 8.3 11.8 14.8 17.7 20.7 23.6 26.6 29.5 32.5 35.4 

63~ I 2:1 4. 2 I 5.6 7.0 8.3 9. 7 11. 1 12.5 13.9 15.3 16.7 I 
CISTERNS. 57 

LOCATION. 

Theoretically the location of a cistern n1akes little difference in its 

liability to pollution, but practically it is ofthe greatest importance. 

As has been indicated, cracks in the walls are of common occurrence, 

in some cisterns being sufficiently open to admit eno1_1gh outside 

water to make the supply noticeably hard, and where such wa,ter 

can enter pollution can enter also. Bacteria or disease germs can 

develop in substances which can not be filtered from· the water and 

it is entirely possible for pollution by such means to enter the cistern 

through cement walls even when there are no cracks. It is therefore 

highly desirable that the cistern should not be located near a sewage 

drain, barnyard, or other source of contamination, the same precautions being observed as have been indicated for wells (pp. 44-45). 

The site selected should be in firm ground, as otherwise there will be 

danger of the cistern settling and cracking. Roots of trees are also 

a frequent cause of injury, and cisterns should be located as far away 

from them as possible. 

CONSTRUCTION. 

The excavation should be made large enough and deep enough to 

permit the laying of proper foundations and adequate walls. For curbing either stone or brick laid in mortar and cemented on the inside with 

a thick coating of hydraulic cement may be used. It is preferable that 

the top be arched over with brick or stone and lined with cement. 

An opening, provided with an air-tight cover, through which a person 

may enter the cistern for purposes of examination, cleaning, and 

repair, should be left at the top. After the completion of the cistern, 

it should be frequently examined, in order to detect and remedy any 

cracks or other defects due to settling, the action of frost, penetration 

of tree roots, etc. 

COMBINATION WELLS AND CISTERNS. 

Although cisterns of the dimensions indicated in the preceding section will supply enough water for domestic use in a small family, they 

will not supply enough for stock. In fact, unless the farm buildings are 

very large or numerous it is, as a rule, impracticable to procure enough 

cistern water to supply more than a few head of stock, and it is therefore generally necessary to utilize the ground-water supplies. These 

are sometimes too far from the surface to be available during the summer, but there is almost always enough water in the ground in winter, 

and the ideal provision would be to store a portion of the winter supply 

for summer use. 

In the winter the ground-water level is high, often standing only 

a few feet below the surface, but in summer it is usually much lower, 

often many feet from the top of the ground. If a well is carried deep 
58 UNDERGROUND WATERS FOR FARM USE. 

enough, sufficient water can in most places be obtained, but many 

wells are too shallow to give never-failing supplies, and as a consequence 

they may be short of water in times of drought. If the water in the 

well in the winter could be retained till summer, there would be little 

difficulty with the supply of most wells, but, unfortunately, as· the 

ground-water level falls the water in the wells falls also. In figure 27 

ae indicates the depth of water in a well during the winter, and be 

indicates its depth in the summer when the water level is at b. The 

volume at depth ac might be sufficient for the whole year, and that at 

depth be insufficient to last through the summer. To preserve the 

winter supply it is necessary to cement the bottom and walls of the well 

nearly to the winter water level, as 

shown by the heavy lines in the figure, 

thus converting it into a semicistern. 

When this is done the well will fill during the winter to the level a and will 

still contain water to about the level d 

after the ground water has fallen to b. 

Combination wells and cisterns of 

FIGURE 27.-Combination well and cistern. this type are especially dangerous if 

near any source of pollution, hence they are recommended only 

for stock wells located at some distance from buildings and barnyards. They should be used for domestic supplies only where on 

higher ground and at some distance from any source of poilu tion. 

Cisterns completely cemented and covered are safest where buildings 

are near. 

In some places it is the practice to turn the water from buildings 

into a well, but, although the well water is somewhat _softened thereby, 

there is no gain in amount, as water will not stand in an ordinary well 

higher than in the outside ground, the equivalent of the extra water 

turned into the well being lost by outward percolation. 

0