Chapter VII: Water Supply (1)

The use of water enters into each detail of the affairs of everyday life and forms a part of every article of food; its quality has much to do with the health of the family, and its convenience of distribution lends greatly to the contentment of its members. The family water supply should be as carefully guarded as means will permit, and judicious care should be exercised to prevent the possibility of its pollution. Where the source of the water is known, it should be the subject of unremitting attention.

Water comes originally from rain or snow and as it falls, it is pure. Water, however, in falling through the air absorbs the contained vapors and washes the air free from suspended organic matter in the form of dust, so that when it reaches the earth rain water contains some impurities.

As the water is absorbed by the earth, it comes into contact with the mineral matter and organic materials of animal and vegetable origin contained in the soil; and as water is a most wonderful solvent, it soon contains mineral salts and possibly the leachings from the organic substances through which it passes. The impurities usually found in well water are in the form of mineral salts that have been taken up from the earth, but other contaminating materials may come from the surface and be carried into the well by accidental drainage.

Water that is colorless and odorless is usually considered good for drinking and in the absence of more accurate means of determination may be used as a test of excellence; but it often happens that water possessing these qualities is so heavily freighted with mineral salts as to be the direct cause of impaired health. Again, water that appears pure may be polluted with disease-producing bacteria to such an extent as to endanger the lives of all who use it. The fact that a source of drinking water bears a local reputation for purity, because of long usage, cannot be taken as a test of its actual purity until it has been subjected to chemical and bacterial examination.

It must not be inferred that all water is likely to be unsuitable for drinking; there is, however, a possibility of the water being polluted from natural sources and from accidental causes, that are sometimes preventable; and the only means of determining the purity of water is by chemical and bacterial examining.

=Water Analysis.=--In order to be assured as to the quality of drinking water, it should be subjected to analysis and the result of the analysis inspected by a physician of good standing. Such analysis may usually be obtained free of charge from the State Board of Health and if asked, the Chief Chemist will usually give his opinion regarding the quality as drinking water.

In chemical water analysis, the total amount of solids, regardless of their nature is taken as indicative of its excellence for drinking purposes. These solids may be either in suspension and give the water a color or produce a turbidity, or they may be entirely in solution and the water appear colorless. English authorities on the subject place the allowable proportion of solids at 500 parts to the million. Any water that contains more than 500 parts to the million is condemned for drinking purposes. Water containing 500 parts or less to the million is considered good. The Standard of the American Board of Health permits the use of water for city supply that contains 1000 parts of solid matter to the million.

The amount of solids contained in water is not at all a definite indication of its quality for drinking purposes, as may be inferred from the widely varying amounts permitted by the different authorities, but it gives an indication of its character because of the known physiological action of the contained solids.

Chemical analysis alone cannot be taken as a complete indication of the character of water, because such analysis shows nothing of the bacteria that may be present. The organic matter may indicate the possible presence of bacteria, but microscopic examination will be required to determine its harmful properties.

As examples of the chemical constituents of potable waters, the following furnish illustrations of different types of water in general use.

=Pokegama Water.=--The water from Pokegama Spring at Detroit, Minn. is used widely through the Northwest as a table water. It is considered to be a very excellent drinking water because of the low amount of solids and the absence of any deleterious constituents. The complete chemical analysis as reported by the North Dakota Pure Food Laboratory is as follows:

Grains per gallon
Sodium chloride 0.0200
Sodium sulphate 0.0357
Sodium carbonate 3.9288
Calcium carbonate 11.3997
Lime carbonate 0.0016
Magnesium carbonate 3.8896
Sodium phosphate trace
Potassium sulphate 0.4435
Silica 0.4416
Organic matter 0.1006
--------
Total 20.2611

The total solids, 20.2611 grains per gallon, equivalent to 346.85 parts per million, is very low and composed of carbonates of sodium, calcium and magnesium, none of which are in any way harmful even in much larger quantities. The amount of organic matter is practically nothing.

=River Water.=--The water supply of the city of Fargo, N. D., is taken from the Red River of the North, which after being filtered through a mechanical filtration plant is supplied to the water system of the city. The river water in its raw state is considered unfit for drinking because of the amount of organic matter present at different times of the year.

Analysis of raw water from intake pipe, April 14, 1913:

Parts per million
Chlorine 10
Equivalent as sodium chloride, salt 16
Volatile and organic matter 80
Mineral solids 180
----
Total solids 260

In this water neither the solids nor the organic matter are at all high but during a part of each year there are many pathogenic germs present, the contained typhoid bacillus being the most feared. The following is an analysis after the water has been filtered, April 14, 1913:

Parts per million
Chlorine 12
Equivalent as sodium chloride, salt 18
Volatile and organic matter 45
Mineral solids 140
----
Total solids 185

It will be noticed that in the process of filtration there has been removed from the water 35 parts to the million of organic matter and with probably 99 per cent. of the pathogenic bacteria. In addition there has been removed 40 parts to the million of mineral solids, the removal of which has changed a _very hard_ water to that which is reasonably soft. The process of filtration has changed water that is generally condemned for drinking to one that is considered remarkably good.

=Artesian Water.=--The analysis of the sample of artesian water given below is an example of the water analysis made by the North Dakota Pure Food Laboratory. It furnishes an illustration of the type of reports that are returned from samples of water submitted for examination. This report was in the form of a letter which was taken at random from the files of the laboratory.

Sample of artesian water No. 1936 from Moorhead, Minn.:

Parts per million
Chlorine 70
Equivalent as sodium chloride, salt 116
Volatile and organic matter 90
Mineral solids 455
----
Total solids 545

“The solids in this water are made up of sodium chloride, salt,
116 parts; volatile and organic matter, 90 parts; lime sulphate,
a trace; lime carbonate, a slight amount; magnesium carbonate, a
slight amount; and the balance of the solids are all wholly made
up of sodium bicarbonate. This water is low in solids and of good
quality.”

=Medical Water.=--The solids that occur most commonly in spring and well water appear in the form of mineral salts. It frequently happens that salts giving a cathartic action are present in sufficient quantity to render the water objectionable when used for drinking. Sodium chloride or common salt frequently occurs in quantity sufficient to be distinctly noticeable. Magnesium sulphate (Epsom salts) and sodium sulphate (Glauber salts), both of which are well-known laxative salts, very commonly occur in well water. The carbonates of calcium and sulphur also frequently found in well water are inert in physical action when taken in drinking water. The presence of laxative salts in spring water has given great celebrity to many springs both in Europe and America that are famous as cures for all manner of human ills. Such curative value as these springs possess is derived from the cathartic salts contained by the water.

The table of contents of the Saratoga Congress Water as given by Dr. Woods Hutchinson shows the solids of one of the most celebrated of America’s medicinal waters.

Grains per gallon
Sodium chloride 385
Magnesium carbonate 56
Calcium carbonate and sulphate 116
Sodium bicarbonate 9
Sodium iodide 4
Bromide, iron, silica trace
-----
Total solids 570

When reduced to ordinary measure and given their common names the mineral solids in a gallon of this water will be approximately:

Common salt 8 teaspoonfuls
Magnesium 1 teaspoonful
Lime and plaster of Paris 2 teaspoonfuls
Baking soda 1/6 teaspoonful
Bromides and iodides 1/12 teaspoonful

The total solids, 570 grains per gallon, contained in Saratoga water, gives the remarkably high content in total solids, of 9758 parts per million; this is almost ten times the limit of the American standard. While such water would not do for constant consumption, it is taken for considerable periods of time with beneficial results and is recommended by many authorities as a water of great medicinal potency.

While most medical authorities condemn the use of water high in solids, the ideal drinking water is neither soft water nor distilled water--that is, water that is perfectly free from any saltiness--but one that contains a moderate amount of the ordinary constituents of the earth. It is reasonably safe to assume that any unpolluted water containing as high percentage of solids as 1000 parts of total solids to the million, and that is agreeable to the taste, would be safe for drinking.

“Chemical analysis in general indicates the possible pollution
of water. A relatively high content of organic substances,
nitrate, chlorides and sulphates, might indicate contamination,
particularly when ammonia is also present. On the other hand, a
high content of just one of the above-mentioned substances, be it
organic, chloride, nitrate or sulphate, may originate from the
natural soil strata.”

=Organic Matter.=--Organic matter may come from peat swamps, decaying leaves and grasses; or it may come from decayed animal matter which finds its way into the soil; or worst of all it may come from cesspools or other sewage. While the presence of organic matter does not necessarily indicate the presence of disease-producing bacteria, it is a medium in which such germs live and multiply; for that reason it is an indicator of possible harm.

“Waters containing a high percentage of organic substances and
among them products of putrefaction are frequently used without
damage but they are capable of producing gastro-intestinal
catarrh, phenomena of excitement and paralysis as well as death.
Of the many pathogenic bacteria that sooner or later may get into
the water, those of cholera and typhoid are of special importance.

“Pathogenic bacteria occur but rarely and when once they find
their way into a water, they generally do not multiply but remain
for a greater or lesser period viable.

“Bacteria enter wells by three different modes: first, from
surface water that is washed from the soil by rain; second, from
faulty construction of the curbing; and third, from bacteria
entering the soil from vaults, etc.” (Van Es).

=Ammonia.=--In the analysis of water the presence of ammonia is an indicator of organic matter. Ammonia is not of itself injurious but it indicates the presence of matter in which bacteria find conditions suited to their growth. Free ammonia is usually considered an indicator of recent pollution, while albuminoid ammonia indicates the presence of nitrogenous matter that has not undergone sufficient decomposition to form ammonia compounds.

=Hardness in Water.=--Water that holds no mineral matter in solution is “soft water” and when soap is added will readily form a lather. The presence of lime or magnesia is commonly the cause of “hardness” in water. Either of these minerals, when present form an insoluble curd when the soap is added to the water and the soap will not form a lather until enough soap has been added to unite with the mineral matter present. The hardening agents are usually in the form of bicarbonates and sulphates. All soap used in neutralizing the hardening agents is wasted, because a lather will not form until all of the hardening materials are neutralized. It is evident that the softening of water for domestic purposes is beneficial, both because of the less amount of soap required and because of the absence of the curd.

Hardness in water may occur in two forms--as temporary hardness or as permanent hardness. When bicarbonate predominates as the hardening agent, the water is said to be temporarily hard because, when heated to boiling, the bicarbonate is precipitated and the water is thus softened. When softening of such water is to be done on a large scale, chemical treatment is more satisfactory. Water containing bicarbonate of lime may be softened by adding a pound of lime to 1000 gallons or 1 pound of lime to 165 cubic feet of the water. This quantity of lime is sufficient to remove 10 grains of the bicarbonate to the gallon.

When the mineral matter is in the form of sulphates, mainly sulphate of lime or magnesia, the water is said to be permanently hard, because boiling will not soften it. Such water may be softened by adding soda ash or impure carbonate of soda. One pound to 1-1/4 pounds of “washing soda” to each 1000 gallons of water will render such water soft; by its action the sulphate of lime is precipitated and settles to the bottom of the container; the water may then be siphoned off leaving the precipitate in the bottom.

=Iron in Water.=--Water containing iron is found in many wells and springs. While iron is not harmful, it is objectionable to taste and stains most things with which it is long in contact. It may be precipitated with lime and removed as the sulphate of magnesia described in the preceding paragraph.

=Water Softening with Hydrated Silicates.=--By W. L. Stockham, assistant chemist, North Dakota Experiment Station.

“The use of chemicals in softening water requires the mechanical
removal of the separated materials by skimming, settling or
filtering and it is difficult to determine just how much chemical
to add. A new process for softening water, and one that has
awakened great interest because of its efficiency, employs
hydrated silicates of aluminum or iron combined with soluble
bases. This process softens water from practically any condition
or hardness.

“The form of apparatus in use varies from a portable jar, with an
inlet at the top and an outlet at the bottom, to the more complex
tanks for industrial and domestic purposes. A plant for domestic
use might consist of a 20-gallon tank for containing the softening
material and a second tank in which is prepared the salt solution
for reactivating the softener. The two tanks with their valves
and connections constitute the apparatus. The softener, supported
by a porous plate, sieve, or layer of gravel, completely fills
the first tank and the water to be treated passes through the
interspaces between the granules. In some plants the water passes
through a layer of marble chips before coming into contact with
the softener. The apparatus may be attached temporarily to the
faucet or connected permanently with the water system. A gravity
system may be employed where the water pressure is lacking.

“The softener is put on the market in granular form and may be
purchased and used with apparatus other than that furnished by
manufacturers. The granules are about 1/4 inch in diameter and
permit a ready passage of the water through the interspaces. The
material lasts indefinitely.

“As the water passes through the apparatus, the large exposed
surface of the granules entirely absorbs the calcium and
magnesium, which produce hardness, making it soft and ready for
immediate use. The water does not require being in contact with
the softener any longer than the time taken to pass through and
it emerges almost as fast as from the faucet. The softener must
be reactivated after it has softened a certain amount of water.
This is accomplished by filling the tank with a common salt
solution which is contained in the second tank. The water supply
is temporarily shut off and the salt solution allowed to fill the
softening tank. After remaining in contact with the granules
for a time the chemical action of the salt releases the calcium
and magnesium, which are flushed out with the excess of salt
solution, into the sewer. The softener thus renewed is ready for
softening another supply of water. Since this renewal is a simple
application of the law of mass action, an excess of the salt must
be used. The renewal may be repeated indefinitely.

“The amount of any particular sample of water which can be
softened before renewal depends on the amount of material in the
apparatus and the hardness of the water. Five gallons of the water
per pound of softener would not be far from the average capacity.
Where a large amount of soft water is required at one time, it may
be prepared in advance and accumulated in a tank or cistern.

“The cost of softening, aside from the original cost of the plant,
is nominal, as the value of the salt solution is the only expense.

“The water produced by this process is absolutely soft and
suitable for drinking, domestic and industrial purposes. In the
case of very hard water the saving in soap for washing is more
than equal to the cost of operation. There are at least three
firms manufacturing softening plants of the kind at the present
time: The Permutite Co. of New York; the Cartright Co. of Chicago,
whose product is called Borromite; and the Des Moines Refining
Co., manufacturers of Refinite.

“A comparative test of various forms of water-softening materials
may be obtained from the Regulatory Department, North Dakota
Agricultural College.”

=Chlorine.=--The presence of chlorine in water may indicate the presence of polluting matter in the form of sewage but only when the amount is considerably above the normal amount of chlorine that is contained in the soil in the community from which the water is taken. An increase of the chlorine in the water would indicate a probable pollution from sewage.

=Polluted Water.=--Well water that is roily or that possesses objectionable taste or odor may be suspected of containing polluting matter and should be boiled before being used for drinking purposes until such time as may be required to have it examined. Sickness due to the use of polluted water does not necessarily develop as specific diseases, unless the water contains disease-producing bacteria. Typhoid fever, one of the commonest and most dreaded of diseases, is usually transmitted by water. Typhoid is a disease of human origin, the germ of which develops in the alimentary tract of the human kind alone. The germs may be spread by the waste from the typhoid patient by being thrown on the ground where it is taken up by the water and passes into streams or it may enter wells from privies or cesspools. A single case of typhoid has been known to so pollute the water of a stream, as to produce an epidemic of the disease throughout the entire length of the stream, among the people who drank its water; while water from a polluted well often transmits disease to a neighborhood.

=Pollution of Wells.=--The water from wells is often polluted by seepage through the earth from sources that might be prevented. Fig. 123 illustrates some of the commonest sources of contamination that through carelessness or ignorance are located in the neighborhood of the family water supply. The drainage from such sources of pollution is often directed toward the well and many cases of ill-health, disease or death are the direct consequences of drinking its water. It may be readily observed, in the case of the well illustrated, that the more water that is pumped from the well, the greater will be the tendency of the water from each of the sources of pollution to reach the well.

Another common cause of contamination of well water is that of imperfect well curbs that allow the waste water or surface water to flow into the well. The area about the well should be graded to allow no standing water, and the waste should be conducted away without permitting it to collect in standing pools.

Drainage from manured fields or other places where disintegrating animal or vegetable matter may be absorbed by water is often the cause of temporary pollution, where the water is carried to low-lying wells. Wells located in low areas that receive the drainage from such places may be suspected of pollution during the spring or early summer, when during the remainder of the year the water is pure.

In connection with any water suspected of pollution, it is well to remember that by boiling the water used for drinking, its harmful properties are entirely destroyed.

=Safe Distance in the Location of Wells.=--In the location of a well, the distance of safety from sources of pollution will depend, in a considerable measure, on the character of the soil and the quantity and concentration of the pollution material entering the ground water. When coming from the surface, the danger is usually neither great nor difficult to avoid; but when cesspools and privies in the neighborhood are sunk to a considerable depth in porous earth, from which the supply of water is drawn, the polluting material may reach the well undiluted. No absolute radius of safety can be given, but certain generalizations as to conditions may be made as to character of soil and the different topographical conditions which surround a safe location.

In ordinary clay, or in clay mixed with pebbles and in soils of the same general nature, through which the water circulates by seepage, the pollution is not likely to be carried to a distance of 100 feet. Clay offers marked resistance to the passage of water, which in beds of 3 to 5 feet thick will act as protection from pollution from above. In sandy soils the movement of water is faster than in clayey soils, but 150 feet may be taken as a safe distance, unless the downward slope of the land carries the polluting material directly to the well.

=Surface Pollution of Wells.=--In dug wells, pollution from the surface is due most commonly to careless construction and lack of care. In Fig. 124 is indicated the most common cause of surface pollution. The figure represents a well that has been curbed with planks. Through lack of care the earth has sunken at the top, permitting the surface water to flow into the well. The top of the well is on a level with the surface and covered with loosely laid boards which allow the waste water to drip through the joints. Such a well, even though the source of supply is good, will likely yield water of inferior quality.

In bored wells, polluting water may enter through the uncemented joints of the tiling or through the joints in the staves of wooden tubing; in drilled or driven wells, through leaky joints or holes eaten in the iron casing by corrosive waters. By cementing the interior surface of stone-or brick-curbed wells, by replacing wood with cement or other impervious curbs and by substituting new pipes for leaky iron casings, the entrance of polluting water may be prevented.

In the average home the water supply is most commonly taken from a well, the water from which comes through the earth from unknown sources, and the character of chemical salts or organic matter the water contains will depend on the kind of soil through which it passes before reaching the well.

The water from wells, whether deep or shallow, is generally of relatively local origin, it being absorbed by the soil and carried to the water stratum by percolation. If the soil contains soluble mineral salts the water will contain these materials in quantities depending on the amount of the salts present in the earth. If the earth contains organic matter as pathogenic bacteria the water is likely to contain these bacteria in like numbers as they are present in the soil through which the water filters.

As usually encountered, the water-bearing earth occurs in sheets rather than in veins or streams. The movement of the water in such areas follows the contour of the earth and is influenced by the varying amount of rain or snowfall and the atmospheric pressure. The lateral movement is often only a few inches a day and in some places no lateral movement occurs at all. Underground streams of any kind are not usually found except in limestone regions.

As a rule, a well is formed by digging or boring into the earth until a stratum of water-bearing soil is encountered, the type of the well being determined by the character of the earth and the location of the water-bearing soil. The water from the surrounding area fills the opening to the height of the saturated soil. As the water is pumped from the well it is replenished by the flow from the surrounding earth. If the soil is porous, as in the case of gravel, the water will refill the well almost as fast as it is taken away by the pump. If the soil is dense and the inward flow is slow, the well when once exhausted may be a long time in refilling.

=Water Table.=--The upper level of the saturated portion of the soil is known as the water table. It has a definite surface that conforms to the broader surface irregularities. While a definite, determinable water table appears only in porous soil, it exists even in dense rocks. It rises and falls in wet seasons and in drought. In exceptionally wet seasons the water table may be at or above the surface. Under such conditions the opportunities for the pollution of wells is much increased. In particularly dry seasons the water table may sink below the bottom of the well, when it is said to “go dry.” The water table follows the surface contour in a manner depending on the character of the soil. It is flattest in sand or gravel areas but in clay it follows the contour of deep slopes with but slight variation.

=The Devining Rod.=--The use of the devining rod, for the purpose of locating suitable sites for wells, has been supposed by many to be a gift possessed by a chosen few. The devining rod is a forked branch of witch hazel, peach or other wood, which when held in the hands and carried over the ground, is supposed to indicate the presence of water by bending toward it.

In most cases the operators are entirely honest in their belief and in a large proportion of trial their efforts have been successful in locating desirable wells; but it has many times been proven that the movement of the rod is due to an unconscious muscular movement of the arms and hands, in places where the operator has previously suspected the presence of water. The operator of the devining rods is most successful in regions where water occurs in sheets, such as often occur in gravel or pebbly clay. The successful use of the devining rod cannot be explained by any scientific reasons. There have been invented a number of devining rods, claimed by their inventors to be based on scientific laws; but the government has not yet granted patents to appliances of the kind.

=Selection of a Type of Well.=--The chief factor which controls the selection of a type of well is the nature of the water-bearing earth, the amount of water required, the cost of construction and the care of the resulting supply.

If a large amount of water is to be demanded of a well, to be dug in soil through which the water percolates slowly, the well must be large in diameter, in order that the necessary supply may be accumulated. If the earth is porous and yields its water readily, a small iron pipe driven into the ground may supply the desired amount.

The character of the water-bearing material is of the greatest importance in determining the yield of the well. In quicksand, water is usually present in ample quantities, yet owing to the extremely fine particles of which the quicksand is composed, its presence as a water-bearing soil is highly undesirable.

=Flowing Wells.=--Flowing wells are obtained in places where water is confined in the earth, under sufficient pressure to lift it to the surface, through an opening made to the water-bearing stratum. These are known as artesian wells, from the fact that they were first used in Artois (anciently called Artesium) in France. In order that water may have sufficient head to lift it to the surface, it must be confined under impervious clay or other bed of earth, and with its source at a level considerably higher than its point of exit. The source of supply for flowing wells is often at a great distance. Because of the fact that flowing wells are shut off from the surface by an impervious layer of earth, the possibility of pollution from the surface is effectively prevented. Any contamination of the water must come from a distance and enter the water at its source. As pollution rarely extends through the ground to any great lateral distance, artesian waters are seldom polluted. The water from artesian wells often is heavy with mineral matter and in many cases is unfit for drinking on that account.

CONSTRUCTION OF WELLS

Wells are constructed by different methods, depending on the character of the soil in which they are sunk. Their excavation is usually accomplished by one of three general methods: by digging; by driving a pipe into the earth until it penetrates the water-bearing stratum; or by boring a hole with an enlarged earth auger, into the water-bearing soil. Artesian wells are made by drilling with a device suitable for making a small and very deep hole.

=Dug Wells.=--In shallow wells the water seeps through the soil from local precipitation. Deep wells are those from which the water is brought to the surface through an impervious geologic formation, as a bed of clay or rock, and from a depth greater than that from which water may be lifted by atmospheric pressure. The fact that a deep well originates from a source that entirely differs from that of the shallow well accounts for the difference in chemical composition which frequently exists in the water from the two types of wells in the same neighborhood.

The form of the dug well is generally that of a cylindrical shaft 4 feet or more in diameter and of depth depending on the location of the water-bearing stratum. Where the character of the soil is such that the seepage is slow and the water does not flow into the well as fast as the pump will remove it, the well must contain a considerable volume to supply the period of greatest demand. Wells of this kind are commonly walled with brick or stone to keep the sides in place and to prevent the entrance of surface waters. The top of this curb should be brought above the surface of the ground and should be made water-tight to prevent the entrance of surface waters. The space around the curb, at the surface, should be graded to drain the water away from the well. There should be no chance for the water to collect in pools about the well; it should be conducted away in a gutter to the place of final disposal. The well should be covered with a platform of concrete or planking which will allow no water to enter from the surface.

Wells of this order are sometimes dug to great depth before the water-bearing stratum is encountered; this may sometimes be reached only after a great amount of expense and labor. The historic Joseph Well, near Cairo, Egypt, is an open shaft, 18 by 24 feet in area, sunk through solid rock 160 feet.

=Open Wells.=--Open wells have long been condemned as insanitary. The familiar open well of the “Old Oaken Bucket” type is an inviting receptacle for the deposit of all manner of refuse, which once inside remains until it is disintegrated. These wells become the final resting place of many small animals and all manner of creeping things, in search of water. The open top receives wind-blown matter in the form of leaves and dust, much of which is in the nature of polluting material.

=The Ideal Well.=--In the case of a well which yields pure water, every precaution should be taken to prevent its pollution. The ideal form of construction is that shown in Fig. 125. In this well, the curbing _C_ is of heavy concrete that extends above the natural surface of the ground, to prevent the entrance of surface water, and that from seepage through the upper stratum of the soil. The reinforced-concrete top forms a close joint with the curb to prevent the entrance of waste water and all animal life. The pump is of iron, secured to the well cover by bolts, set in the concrete. The trough of concrete _G_ conducts the waste water from the well to a safe distance. The earth about the well is so graded as to permit no water to stand in pools.

=Coverings of Concrete.=--The use of concrete for the coverings of wells, cisterns and springs has become a recognized form of the best construction. It is not more expensive than other good materials and when properly executed it forms an imperishable protection and gives a neat appearance. The spring cover in Fig. 126, and the cistern top in Fig. 127 are illustrations of its application.

=Artesian Wells.=--Artesian wells are made by boring into the earth until the drill reaches the artesian stratum, the internal pressure forces the water through the opening to the surface. They are usually small in diameter and often of great depth. In some areas the artesian flow is found a few feet below the surface, but generally it is much deeper and 3000 feet is not an unusual depth.

The pressure and amount of flow from these wells is sometimes sufficient to permit the water being used for the generation of power. Small waterwheels are not uncommonly driven in this way and the power used for the generation of electricity for lighting and running small household appliances.

=Driven Wells.=--In localities where the nature of the soil gives opportunity, wells are made by driving a pipe to the required depth. Wells of this character are usually made in places where the water-bearing soil is of sand or gravel. The pipe terminates in a sand-point such as that of Fig. 128. This sand-point is a perforated pipe with a pointed end, that facilitates driving. The perforations, as shown in the point _P_, form a strainer which allows the water to enter the pipe but prevents the sand from filling the opening.

In the use of driven wells, the water-bearing soil must be sufficiently open to allow the water to flow into the pipe as fast as the pump takes it away.

=Bored Wells.=--In many localities the water-bearing stratum is of such nature as to give a ready flow of water but yet not sufficient to permit of the use of a sand-strainer; if, however, the opening is somewhat enlarged, the water will enter with sufficient rapidity to supply a pump. In such cases bored wells are quite generally used. They are made by boring a hole of the required size with an earth auger. These wells are made of any size up to 2 feet in diameter. They are often called tubular wells because they are lined with iron tubing or tile, to prevent the earth from refilling the hole.

=Cleaning of Wells.=--Very few dug wells are so constructed as to exclude dust and washings from the ground. It is, therefore, necessary that they be occasionally cleaned. Accumulations from these causes may be sufficient to hinder the entrance of the water to the well and thus lessen its capacity.

=Gases in Wells.=--One of the commonest gases found in wells is carbon dioxide (carbonic acid gas). It may be detected by lowering a lighted candle or lantern to the bottom. If the gas is present in dangerous quantity, the flame will be extinguished. Death from asphyxiation due to this gas is not an uncommon occurrence, to persons descending into wells. Before entering a well, the test described above should be applied, as a precaution against accident. Carbon dioxide is a colorless, odorless gas in which a person will drown as readily as in water.

=Peculiarities of Wells.=--Owing to the formation of the water-bearing earths, from which they receive their water, many wells possess marked peculiarities of behavior that often give rise to local reputation because of their vagaries. These characteristics have been classified into breathing wells, blowing wells, sucking wells, etc. These effects are in almost every case due to variation of barometric pressure. The ordinary level of the water in a well is governed by the variation of rainfall, melting of snow or the release of water by the thawing of frozen ground. It often occurs, however, that the head of water is markedly influenced by storms, when a rise of the level of the water occurs at the time of low barometric pressure during the storm period. This effect is often noticed in flowing wells. Many wells, at the approach of storms, yield roily water to such an extent that where the water is normally clear it may become for a period entirely unfit to drink, because of the matter held in suspension. All of these effects are accounted for by the varying atmospheric pressure. At the time of high barometer, a well that ordinarily flows freely will have to be pumped, the additional pressure of the air holding back the water to an extent representing several feet of head. The change of an inch in the barometric pressure will produce slightly more than a foot in head of water. At the time of storms, the barometer is sometimes abnormally low which will produce a corresponding rise of water in the well. At such time the free flow of water into a dug well, from the usual source of supply, will cause such a rapid flow of water through the passages in the earth as to carry with the water the sediment that produces roily water in the well. This sediment will settle after a while and the water will again be clear.

=Breathing Well.=--Wells of this kind are most common in areas where the water-bearing earth is of rock formation; particularly in limestone areas, where caves and cavities are common. It sometimes happens that in the neighborhood of a well there is a cavity in the earth of considerable volume, the only entrance to which is through the well and that being under usual conditions covered by water, a foot or more in depth. With such a formation the conditions are right for a breathing well. At times of high barometer the water is depressed and the air will flow into the cavity through the well, when the well is said to inhale. This inward flow of air will continue until the air pressure in the cavity is equal to that of the outer air; and if the cavity is large and the opening small, the inward flow of air may continue for hours, even for days. With a fall of barometric pressure, the air in the cavity, being at a higher pressure than the external air, the air will flow outward and the well is said to exhale.

=Freezing Wells.=--In cold climates, particularly in territory possessing cavernous limestone deposits, breathing wells often freeze in winter. When large volumes of frigid air are drawn into a well, the amount of heat taken from the water is sufficient to freeze it, and stop the supply of water. This effect is sometimes remedied by plugging the well at the top, so that the influx of cold air is prevented and the water does not freeze.

PUMPS

Pumps for lifting and elevating water are made of both wood and iron in almost endless variety; but for domestic purposes they are of two general types--the lift pump and the force pump--which include features that are common to all. The lift pump is intended for use in lifting water from low-head cisterns and wells, the depth of which is not beyond the head furnished by atmospheric pressure. The force pump performs the work of a lift pump and in addition forces the water from the outlet at a pressure to suit any domestic application. These pumps are made by manufacturers in a great variety of forms, but the essential parts are the same in all pumps intended for a single purpose. The principle of operation is the same in all pumps of any type. The difference in mechanism of pumps intended for the same purpose is only in the form and arrangement of the parts.

=The Lift Pump.=--The kitchen pump is an example of the lift pump. It is universally used for household purposes where water is to be raised from cisterns, etc., and is most commonly made throughout of cast iron. Fig. 129 illustrates one form, sometimes called the pitcher pump, because of the slight resemblance to the article. It frequently carries the name cistern pump from the fact that it very generally is used to lift water from cisterns.

Although water may be raised 34 feet with a theoretically perfect pump and with a barometric pressure of 30 inches the actual limit is much lower. In use, 20 feet is probably about the limit and 10 feet or less is that of common practice. A pump that requires “priming” would raise water 15 feet with considerable difficulty for reasons that will appear later. In Fig. 129 is shown a sectional view of the working parts of the kitchen pump, the action and general form of which apply to any lift pump. The body of the pump contains a cylinder, in which closely fits a piston _P_, containing a valve _A_. At the bottom of the cylinder is an additional valve _B_. The piston and two valves constitute the working parts of the pump. The water is lifted through the pipe _S_, and is discharged at _D_.

The action of the pump is as follows: With the piston at the bottom of the cylinders and with no water in the pump, the handle is forced down, which action raised the piston. In so doing the air below it is rarefied. The reduction of pressure due to the rarefication of the air allows the water to rise in the pipe _S_ correspondingly. After repeated strokes of the piston, the water reaches the valve _B_, which raises to let it pass, but immediately closes at the end of the upward stroke. When the space between the piston and the valve _B_ is filled with water, each descent of the piston forces the water through the valve _A_; and when the piston is raised, the water is lifted out through the spout.

The valve _A_ is a loose piece of cast iron, surfaced on the lower side to make good contact with the piston. The valve _B_ is of cast iron fastened to a piece of leather by a screw. The leather makes a joint with the valve-seat and furnishes an excellent valve for its use. In order to keep the plunger _P_ tight in the cylinder, it is surrounded with a leather gasket. Should this gasket become worn, as it will in time, the plunger fits loosely in the cylinder and the pump will lift the water with difficulty, because of the leakage around the gasket. Should the valve _B_ leak, the water will gradually run back into the pipe _S_, and the pump when left idle will lose its “priming.” The plunger and the valve _B_ are the parts most likely to get out of order. If the gasket around the piston _P_ is very much worn, and there is no water in cylinder, the pump will require priming before the water can be raised. If the pump contains no water and is left standing for a considerable time, the leather parts of the valve dry out and shrink; when the pump is again put into use, the valves will fail to work properly, until the leathers are again water-soaked. Water is poured into the top of the pump until the cylinder is filled, and as soon as the leather becomes water-soaked and fills the cylinder, the piston will again perform its function.

=The Force Pump.=--The house force pump is often used in place of the ordinary lift pump, when no other means is at hand for providing water under pressure. It furnishes a limited means for lawn sprinkling and gives some degree of fire protection in isolated places. It may be made a part of the kitchen sink as shown in Fig. 130, by use of the attachment that appears in detail under the sink. This type of pump may be used in small water-supply plants, such as that of Fig. 143; or in connection with small pressure tanks for the same purpose. It differs somewhat in construction from the lift pump, in that it has no valve in the piston and is provided with a check valve and an air chamber for generating pressure to the discharged water.

Fig. 131 shows the essential parts of the force pump and furnishes a means of describing its operation. All force pumps possess the same parts and the operation described applies with equal force to all. A valve _A_ is located in the bottom of the cylinder and the check valve _B_ prevents the return of the water to the cylinder after it has been forced out of the pump. The action of the pump in raising the water is the same as in the lift pump but when the water fills the cylinder and the piston descends, the water is forced through the valve _B_ and out at _D_. If the outlet pipe is slightly smaller than the opening in the valve _B_, some of the water will enter the air chamber _C_ and compress the air. The pressure thus generated will immediately tend to force the water out and in course of ordinary pumping will send out a steady stream instead of the intermittent flow of the lift pump. Without the air chamber, the flow from this pump will be a series of pulsations that attain maximum force with each descent of the piston.

=Tank Pump.=--The type of pump used with a water-supply plant will depend entirely on the amount of water that is used. If the supply of water to be provided is for only one or two people the house force pump such as that of Fig. 130 will suffice; but when a greater number of people are to be supplied, a force pump of the type shown in Fig. 132 is quite generally used. These pumps are made in a variety of patterns and are commonly termed tank pumps. The one shown in the Fig. 132 is a double-acting force pump in that the cylinder receives and discharges water at each stroke of the piston. The air chamber is located at _A_. Directly beneath the air chamber is the valve chest in which are located the valves which regulate the entrance and discharge of the water. As used in the average domestic plant the cylinders are 3 or 4 inches in diameter.

WELL PUMPS

The pumps intended for raising water from wells are practically the same in construction as the house pump, except that they are intended to deliver a greater volume of water and sometimes to work under a different condition, as that of the deep well pump. Well pumps have, therefore, assumed certain standard forms that differ only in the styles of mechanism employed by different manufacturers.

The one shown in Fig. 133 furnishes a good example of a general-purpose iron pump which may be used either as a force pump or a lift pump. It represents also the general construction of a deep-well pump, where the water must be lifted from a level, below that at which a lift pump will work.

The piston and valves are enclosed in the cylinder _C_, placed below the surface of the water in the well. This cylinder also appears in section in the small drawing, showing the details of the valve. The operation of this pump is identical to that of the lift pump already described, but the addition of an air chamber gives it the necessary facility to produce a continuous flow of water. In order to prevent the air in the air chamber from escaping, the pump rod is surrounded with the necessary stuffing-box which is usually packed with candle wicking to assure a good joint. In deep wells the tube is elongated sufficiently to place the cylinder _C_ below the surface of the water in the well. Such pumps are operated either by hand or by power.

=Wooden Pump.=--The wooden pump of Fig. 134 furnishes a good illustration of a type that was formerly used in great numbers. It is an inexpensive and efficient pump made almost entirely of wood except the cylinder which is quite generally made of iron, lined with enamel. The valve and the piston with its valves are made of wood, but faced with leather to insure tight joints. The piston is also provided with leather packing to make it tight in the cylinder. The action of the pump is the same as that already described. The wooden tube is made in sections joined together by taper joints that are driven into place.

The piece at the side of the pump is provided to drain the water from above the piston, as a precaution against freezing during extremely cold weather. The rod, when raised, opens an orifice that leads to the inside of the pump and permits the water to drain into the well.

=Pumps for Driven Wells.=--The method of constructing driven wells--that of driving a pipe into the earth to the water-bearing stratum of sand or gravel--requires a special end to prevent the pump tube from becoming stopped. In order that the fine material may not enter and fill the lower end of the tube, a sand-point is used, such as that shown in Fig. 128. It is made of perforated brass tubing and provided with a sharpened end to facilitate driving. The perforations act as a strainer that keeps out all but the fine particles which will pass the pump valves. Sand-points are made with strainers of various degrees of fineness to suit the different conditions of soils. These strainers may in the course of time become filled with particles of the soil that lodge in the perforations and the outside become so encrusted as to prevent the entrance of the water. In such case, the pipe must be pulled out of the ground and the point replaced by a new one. In Fig. 128 is shown a driven well with the sand-point in the water-bearing stratum. If the small particles of earth clog the strainer the pump will “work hard” and yield only a portion of the water the soil is capable of giving when the strainer is clear.

=Deep-well Pumps.=--The principle of operation as described in the lift pump takes advantage of the atmospheric pressure to lift the water above the first valve. The limiting distance to which water can be lifted by the atmospheric pressure will depend on the altitude and the atmospheric pressure. With the normal atmospheric pressure at sea level, water can be lifted, theoretically, 34 feet, but in practice the limiting value is never even approximated. The pump is usually placed within 10 of 12 feet of the water and 20 feet is about the limit of distance. The reason for this is because of the impossibility of keeping the joints tight in the valve and tubing.

Where water is to be raised from a deep well, the cylinder with its piston is placed near the water and the tube and rod, as that of Fig. 133, connects the cylinder with the pump stock. After the water has passed the valve in the piston, it may be readily lifted to the pump stock. In this way water is raised from wells of great depth.

=Tubular-well Cylinders.=--Tubular wells that are cased with iron pipe are provided with a special type of pump cylinder that admits of deep-well operation. The casing of the well being in place, the cylinder shown in Fig. 135 is forced down the casing to its proper place, the spring _S_ holding it in place until it is firmly secured. A special seating tool is now lowered into the casing and attaches at _T_ to the coupling; as the tool is turned, rubber packing _R_ is expanded, locking the cylinder firmly to the casing. This makes a complete pump cylinder, which with the piston _P_ in place is operated as any other pump.