nil!!! ,:iii ^5? ■Si TD 927.029 "°""'"™""'"-"'"'>' The farm water supply, Agricultural College Extension UNIVERSITY OF ILLINOIS The Farm Water Supply By EDWARD BARTOW, PH. D., DIRECTOR STATE WATER SURVEY AND PROFESSOR OF SANITARY CHEMISTRY URBANA, ILLINOIS MAY, 1910 Cornell University Library The original of tiiis book is in tine Cornell University Library. There are no known copyright restrictions in the United States on the use of the text. http://www.archive.org/details/cu31924003632860 THE FARM WATER SUPPLY.* It ought not to be necessary to attempt to prove the necessity for an abundant supply of water for the farm, and most people are convinced that the vrater should be pure. As many of us do not realize what pure water is, it is our purpose to explain what constitutes a pure water, why a pure water is needed, and how to get it. What constitutes a pure water? The scientist will tell us that a pure water is water and nothing else. Pure water from his standpoint, is a difficult thing to obtain; because it will dissolve so many substances with which it comes in contact. The purest natural water is rain water. This has been evaporated from the seas, lakes, streams, and from the surface of the earth, leaving the soluble salts behind. Yet even rain water has dissolved gases from the air or has air itself in solution, and is thus not absolutely pure. The purest rain water is obtained after the first fall of rain has cleared the air. As soon as rain water touches the ground it be- gins to dissolve substances with which it comes in contact. Lime- stone, salt, and other mineral substances are dissolved in varying amounts, making the water impure from the scientific standpoint. For drinking purposes small amounts of these substances do not make the water impure, and unless present in excess are beneficial rather than harmful. For our purpose we should ask. What constitutes an impure water? Impure drinking water contains either substances or or- ganisms, or both, which will disturb the functions of the body and cause illness. Excess of some salts, like epsom salts or salts of lime, are injurious. More especially some organisms known as bacteria, if present in the water, will cause disease. According to the germ theory of disease, diseases like typhoid fever, malaria and cholera, •Adapted from a lecture prepared for the Illinois Corn Growers and Stoclnnen's Con- vention, 1908, by Edward Bartow. are caused by these germs. The cholera and typhoid germ are in- troduced into the system by drinking infected water. Water be- comes infected from sewage and house drainage or directly from the excreta of persons who have had the disease. The excreta from one patient has been known to contaminate a water supply and cause an epidemic of typhoid fever to sweep an entire town. These living germs are not dissolved, but are held in suspension. They are too small to be seen by the naked eye and may be present in the clearest water. It is practically impossible to determine them directly, but a water analysis is their indirect determination. Typhoid fever is the principal water-borne disease that we have to deal with. "We cannot tell how much typhoid fever occurs on the farms of Illinois. No statistics are available. It is a fact, how- ever, that typhoid fever is at its height in the cities after the sum- mer vacation. One way of accounting for this is that the people of the city become infected in the country or at the seaside. This may be because their body resistance is less than that of the farmer, whose system is accustomed to the impure water. As one can be- come accustomed to the use of a drug until a large amount can be taken without effect, so it is undoubtedly possible to resist the typhoid fever germs. The farmer is not altogether immune. Many cases occur in his family. When the body resistance is lowered by even a light illness, they become more susceptible and contract the disease. Milk is an excellent carrier of typhoid germs because it fur- nishes abundant food for their growth. It is often infected by im- pure water which is used in washing the milk utensils. Precautions must be taken to keep wells vn dairy farms in good condition. The health departments of Boston, New York, Chicago and Philadelphia make the general requirement that wells on dairy farms "must be free from contamination." The following from the New York City regulations are quoted: Regulations of the Department of Health of New York City, oeeameet regulations. The water used for cleaning pails, cans and other utensils must be from a public water supply, or, if drawn from a weU of spring, must be approved by this department. RULES FOR THE PAIRY. THE WATER SUPPLY. The water used in the barn and for washing milk utensils must be free from contamination. Eesolution of March 31, 1907. Resolved, That when typhoid fever or dysentery exists in any household of any employee of any creamery, farm or dairy, sending milk to New York City, no water from any well or spring within one hundred feet of such premises, or from any well or spring used by the household, shall be used in barns for cleaning milk utensils without the consent of the Department of Health. I will also quote from a letter to the owner of a farm located about sixty miles from New York City, in which the statement is made, ' ' That the privy or cesspool be located not Hearer than 250 feet from the source of the water supply." Adherence to these rules will do much to lower the typhoid fever rate. The importance of a pure water supply on a dairy farm and also on any farm, the water from which may enter the milk supply, may be nicely illustrated by considering the rapid growth of bac- teria. It has been shown that some bacteria under favorable con- ditions, will increase by division every eighteen miautes. This would mean that they would multiply three times in an hour, six times in two hours, etc. Starting with one bacterium, there will be two at the end of eighteen minutes, four at the end of thirty-six minutes, eight at the end of fifty-four minutes, or, say at the end of an hour. With three multiplications during the next hour, at the end of the second hour there will be sixty-four. In three hours and twenty minutes there will be 1,000. In seven hours, 1,000,000, in ten and one-half hours 1,000,000,000, and so on. "We cannot ex- peet this complete multiplication under all conditions, but even should half or one-quarter of the number grow, one can readily see what disaster may follow from a few typhoid fever germs carelessly allowed to enter a can of milk. A large majority of the farm well waters sent to the State Wa- ter Survey for analysis, are sent because the purity of the water is suspected. It is very rare that such a sample is sent in unaccom- panied by a report that there are from one to five cases of typhoid fever among the users of the water. For this reason our records give a very poor idea of the actual conditions of farm waters in the state. During 1907 the State "Water Survey condemned 60 per cent of all well water analyzed, eighty-five per cent of wells condemned were less than 25 feet deep, and 77 per cent of those between 25 and 50 feet deep were condemned. In order to have a more accurate knowledge of the condition of farm water supplies, we need to know the character of waters that are perfectly free from contamination ; or, in other words, we need to determine the normal waters for each district. In order to have such an accurate knowledge, it would be necessary to make a water survey of the state, similar to the soil survey being made under the direction of Professor C. G. Hopkins. The character of the water supply varies as the soils vary, and as the rock strata vary. Since different kinds of earth and different kinds of rock are found at various depths below the surface, we may say that the character of the water also varies with the depth of the wells. Sometimes, as in the case of dug weUs which are cased with brick or stone, the water may enter the wells from various levels; and while a good water might be obtained from the lowest level, there is a possibility of its becoming contaminated by water entering from near the surface or by the water itself washing back into the depths of the well through the curb carrying with it pollution from the surface. The usefulness of germ free waters for farm water supplies varies with the hardness. A hard water contains salts of calcium and magnesium. These salts, when present in water in which meat or vegetables are cooked, form insoluble albuminates. Tea and coffee are not as good when made with hard water. A hard water is also not economical, requiring a larger amount of soap than does a soft water. It causes a scale on the vessels in which it is used, and it is unpleasant for general lavatory and laundry uses. It has been calculated that $180,000 was saved annually by the city of Glasgow by changing from a hard water to the soft Loch Katrine water. In many cases it is possible to use a soft cistern water, and this, when collected on the clean roofs of farm houses, is quite sat- isfactory. "When, however, the cistern water is not available, the hard well water may be easily softened by using chemicals. The most suitable are lime and soda. The lime is used in the form of a sat- urated solution, the soda as one part dissolved in ten parts of water. The lime removes temporary hardness, that is, hardness caused by the presence of carbonates which is mostly removed by boiling. The soda is for the permanent hardness caused by sulphates, chlo- rides and nitrates of calcium and magnesium, which are not removed by boiling. The lime water is prepared by slacking lime and dis- solving the slacked lime in water, or, better, by dissolving hydrated lime in water. A pail of lime water added to from three to ten pails of hard water in a barrel, according to the hardness of the water, will cause the formation of a precipitate which will soon settle, leaving a comparatively soft water suitable for domestic use. It must be noted that the lime does not remain in the water but comes out in the precipitate. In some eases it is necessary to add a little soda. When it is considered that one pound of lime will do the work of fifty pounds of soap, the economy of the prac- tice can easily be seen. On well waters in Illinois, it is safe to use one part of lime water to ten; more should often be used, but this should not be done without preliminary tests. An example of the amount to use is seen in the table of "Hardness of Municipal Water Supplies."* All the soap used before a lather forms is absolutely wasted; then, too, when hard water is used in washing cloth, a precipitate of lime soap or curd collects in the cloth and is difficult to wash out. In order to obtain some definite knowledge of the conditions of a few farm water supplies, we have, during December, 1907, and * Univ. of 111. Bui. Water Survey Series No. 7, p. 100. January, 1908, collected five series of ten samples each, from farms in different parts of the state. An endeavor has been made to obtain water^ from wells in. places where the conditions differ and which are typical of large sections of territory. Other condi- tions undoubtedly exist and' we wish it might have been possible to obtain specific samples from every county in the state. Some times conditions may Vary even in the same county. The collections have been m'adie northwest of Champaign, in Champaign county, from near Centralia, in Marion county; from east of Elgin, most of the samples having been takeil from Cook county ; from northwest of Kankakee, in Kankakee county, and from north of Cairo, in Alexander county. These points were chosen because widely sepa- rated and also because of the differences in sources of supply. The source and characteristics of the water used at these places on the farms follow : CAIEO. A series of ten samples was collected on January 20, 1908, from farms north of Cairo, in Alexander county. The water supply of these farms was quite varied in character. The ten samples in- cluded three cisterns, three shallow driven wells, with pitcher pumps ; three deeper driven wells, and one deep drilled well, which was free fiowing. No. 1. (17004) is a driven well 35 feet deep. Both chemically and bacterially it was shown to be in good condition. No. 2. (17005) is from a cistern located at same place as No. 1. The surroundings were poor and the casing was open. The analysis indicates the possibility of leakage, shown by the alkalinity and the high residue on evaporation. The consumed oxygen, albu- minoid ammonia, and nitrogen as nitrites indicate the presence of organic matters. The number of bacteria was not excessive, but the chemical examination indicated the probability of rapid growth should any infection enter. This cistern water was preferred to ' the well water for drinking by the people living in the house. In our opinion the cistern at this time was not in satisfactory condi- tion, not having been cleaned for about fifteen months. No. 3. (17006) is from a 60-foot drilled well. The water-bearing strata, however, is frora.40 to 45 feet deep. The analysis showed results comparable with. No. 17004, but the water which was clear when first drawn, became turbid on standing and had an odor of hydrogen sulphide. The water is safe. for use for drinking, pur- poses, though the turbidity and odor would render it unattractive.- The residents preferred the cistern water obtained from a cistern reported as No. 4. No. 4. (17007) is from a cistern which, while well curbed, had no covering. It showed evidence of organic matter and a bacterial examination was unfavorable. The well water in this case is pref- erable to the cistern water. No. 5. (17008) is a driven well 50 feet deep. The surroundings were not good, yet the chemical examination was quite favorable. From a bacterial standpoint the water was only fair. The unfavor- able bacterial condition was probably due to defective easing. No. 6. (17009) is a 60-foot driven well located at the tri-city park close to the highway. This water shows high chlorine and nitrates, indicating that surface water from the neighborhood is the source of its supply. The low consumed oxygen, free and al- buminoid ammonia, and the favorable bacterial examination indi- cate that the water is satisfactorily filtered before entering the water-bearing strata and is safe for drinking purposes. No. 7. (17010) is a driven well to which a pitcher pump was attached. This water, while clear when first drawn, became very turbid on standing. Aside from the turbidity, the water is excel- lent for drinking purposes. The people, at the house preferred to use cistern water. No. 8. (17011) is a well near to and similar in character to No. 7, and aside from its turbidity it is in good condition for drinking purposes. The people in the house use this water for drinking pur- poses. No. 9. (17012) is from an artesian well about 800 to 900 feet deep. The water was shown to be excellent, though it has a slight odor of hydrogen sulphide. This water is piped to the farm houses, and is used there. No. 10. (17013) is a cistern water which was well cared for. The surroundings are excellent and the water is filtered. The fil- tration, however, would not entirely remove turbidity and color. The consumed oxygen is high. Baeterially the number of bacteria per cubic centimeter is large, though no positive tests for intestinal bacteria were found. Our conclusions concerning the ten waters taken from near Cairo are that it is possible to obtain a satisfactory water from driven wells about 40 feet deep, although there is a possibility of finding water containing iron, which causes turbidity on exposure to the air. This leads many of the people to prefer cistern water. The cisterns are usually neglected and the water is frequently foul either from washings from the roofs or because of leakages, or from un- satisfactory curbings. The deep artesian well water similar in char- acter to the deep well water obtained at Cairo, would give the more satisfactory water. There is a possibility for several farmers to join together to drill a deep well. They can then have the water piped to their respective farms. The expense of drilling such a well is usually greater than one farmer would care to stand. CBNTEALIA. A series of ten samples was collected on January 7, 1908, from farms near Centralia: No. 1. (16888) is from a 30-foot dug well, Sec. 13, T. 1 N., E. 1 E. The well was about 100 feet from the privy, 150 feet from the stable, 50 feet from the feed lot, 10 feet from dumping ground for slops, dish water and wash water. There had been one case of typhoid fever about two years before. Both the chemical and bac- terial examination indicated pollution. No. 2. (16889) is an 18-foot dug well near No. 1. It is about 30 feet from the stable and is used for stock only. Both the chem- ical and bacteriological data indicate pollution. No. 3.' (16890) is a 24-foot dug well in Brookside township, T. 1, R. 1. The well was dug in clay and eased with brick. All the chemical and bacteriological data would indicate contamination. 's^jBnxaH as. 3 liili •inaea 1, So ■gtd |g 1 •a b 60' driven 30' driven 20' driven •800' to 900' Cisteim •lopni + 1 1+ + + 111 + i 1 ■a -a 10 cii ct;!^ 1 .Liiid •a -a OT I+..M+..+ I 1 1 U- N HH N r-trH HiH « N N N (M ■a a OX 1?; M iHiH ii'I^ •0 -0 jad BiJajoBa CD 00 NrH Oo OOO MCO H ooowo NrHM O TtlNlO to •ijiniiBsilV COCO ceoo NCO CD O CO COtJICOOOO OCOt-TjIlO CO-^COtH 5 •saiBJJiN com OM -^O o^ in OOMOO enoioocD COOlONt- CD " " " * •seiiJllN oo ON coo oo ON O OONOO HOOOO OOOOO \ •pioniranqiv ooo Oi-l oo OH N O COCDOON lOUSCOOO) OOOOO •aaj^ coo OO o § OQOlOCDiO OOOOHO ■painnsuoo naS^xo C0U3 r-K iH N N iH -•& ^ojBjoqBT oo oo c-t- oo oo t-t- 00 o o H 17009 17010 17011 17012 17013 ,£3 -.:||= = : : OuO COi-( ^rpiOCDOiO (NNiHeocoea WW CON +4- +++++-1^ +4- l+l+l l++^l l+l WiH^NWNCOWiHHNiHiH 1 H ++ 1 1 ++ 1 +++ 1 1 iHiH iH W 1- ++-+j^J^ 1 1 iHiH OO oo OON 0*j000O lO moOOO CD 0-(t(00«# 1^ C0O tHN §§ oo 5c0 NOOtH-^OO HO0«JOOC-b- ^^CO'^MCQ 00 CO 55 offl NOO N (M0«0 i-(Ot-o T|)N«O00t- CON OrHin tHi-1 NH oeo coco CO t.co lOOiHiniQCD CDM'^OO'*** t-CD-i*OONin rH iHiHrH OCD coo NH OO oooo go oo OO OOOOOO oo oo OOOOOO oo 00 OS 5oao HiH OrHNCO-^lO O Oi Oi OS n A 00 00 00 00 CO 00 CD CD to CD CO CO cot- OOi 00 00 coco H ri No. 4. (16891) is a 24-foot dug well near No. 3. All the data indicated surface contamination. _ No. 5. (16892) is a 15-foot dug well, 50 feet from privy, 30 feet from stable, 10 feet from feed lot, and 50 feet from a pig pen.'* Both the chemical and bacteriological examinations indicated a satisfac- tory water. No. 6. (16893) is a 36-foot dug well in See. 11, T. 1, E. 1, 75 feet from privy, 100 feet from stable, and 50 feet from feed lot. All the chemical and bacteriological data indicated contamination. No. 7. (16894) is a 30-foot dug well in Sec. 11, T. 1, E. 1, 50 feet from stable and 10 feet from feed lot, practically located in a barn yard. All the data indicated that this water was unsatisfac- tory for drinking purposes. No. 8. (16895) is a 35-foot dug well in Sec: 11, T. 1,.E. 1, 50 feet from privy, and 50 feet from feed lot. The well was cased with brick. All the data would indicate contamination. No. 9. (16896) is a 35-foot dug well, 100 feet from privy, 50 feet from stable, 50 feet from feed lot, and 50 feet from dumping grounds for dish water. All the data indicated that this water was polluted by surface water. No. 10. (16897) is a 25-foot du^ ^ell in Sec. 11, E. 1, T. 1, 100 feet from privy, 40 feet from stable, and 30 feet from feed lot. The curbing in this case is poor. All -the -analytical data indicated pollution. The table gives a summary of the results-obtained in analyzing waters from Centralia. An inspection of the data concerning ten wells at Centralia shows that niae are evidently polluted, and yet in only one case was a report given of typhoid fever among the users of the water. CHAMPAIGN. A series of ten samples was collected on December 19, 1907, from farms northwest of Champaign: No. 1. (16873) is a 160-foot drilled well, in Sec. 2, T. 19 N., E. 8 E. This well is located in a barn yard, 60 feet from a privy, 160 feet from a cesspool, 75 feet from a stable. The anaytical results 10 showed it to be a water similar in coinposition to that furnished by the Champaign and Urbana Water Company. It becomes turbid, due to the presence of soluble iron salts, which become insoluble on exposure to the air, causing not only the turbidity, but also giving a color. From a bacteriological standpoint this water was excel- lent. The turbidity or cloudiness would make it less attraictive as a drinking water than the polluted water in a dug well close by, an account of which is seen under No. 2. No. 2. (16874) is 25 feet deep, in Sec. 2, T. 19 N., R. 8 B. ; is cased with tile and had at that time a covering which was faulty. It is located practically in th6 barn yard, 60 feet from the privy, 150 feet from the cesspool and 60 feet from the stable. From a physical standpoint the water was clear and colorless and had no odor. The chemical examination, however, showed, that it evidently contained considerable quantities of the surface drainage. It also contained an excessive number of bacteria. Such a water should not be used for drinking purposes, though from outward appear- ances a more attractive water than the water from the deep well near by. No. 3. (16873) is a 16-foot dug well, and is located in See. 2, T. 19 N., R. 8 E, and is located 100 feet from privy, 10 feet from the stable and is practically in a barn yard. The chemical analysis showed that this water contained surface drainage. From a bacterio- logical standpoint it was in fair condition, but we would suggest that such water be boiled before using it for drinking purposes. No. 4. (16876) is a 65-foot bored weU, Sec. 35, T. 20 N., R. 8 E., and is cased with cypress, with curbing in poor condition. The well is located in a feed lot about 50 feet from the stable. Physically the water appeared to be good, chemically, poor; bacteriologieally poor. This water was only used for stock and should not be used for drinking purposes. No. 5. (16877) is a 180-foot bored well, and is located in Sec. 35, T. 20 N, R. 8 B., 50 feet from privy, 30 feet from cesspool. The water was similar in character to the Champaign and Urbana supply and was excellent from a sanitary standpoint. U No. 6. (16878) is a 28-foot dug well in Sec. 34, T. 20 N., R. 8 E. Privies and cesspools do not seem to be more than 100 feet distant. It is located near the house iu apparently excellent conditions. Physically it was a bright, clear water, chemically it showed evi- dences of having been collected on inhabited areas. From a bac- teriological standpoint it was good. This water is apparently safe for drinking purposes, but contains a higher residue than is desira- ble and is less suitable for household use than the water from the deep well near by, which is described under the next number. No. 7. (16879) is a 190-foot bored well located in Sec. 34, T. 20 N., E. 8 B. This water showed results similar to the deep wells of the county and is very satisfactory for drinking purposes. No. 8. (16880) is a 170-foot drilled well in Sec. 3, T. 9 N., R. 8 E. This water shows the characteristics of a deep well of the sec- tion and is an excellent water for domestic uses. The water from this well was pumped to the tank by a gasoliae engine located in the basement of the house. No. 9. (16881) is a 28-foot dug well in Sec. 2, T. 19 N., R. 8 E. It is 50 feet from the stable. No other objectionable features seemed to be within 100 feet, but there was apparently a chance for surface water to enter through the curbing. The chemical analysis showed evidences of pollution. No. 10. (16882) is a 160-foot driven well in Sec. 2, T. 19 N., R. 8 E., and while it is practically in the barn yard, near the privy and stable, with a dumping ground for slops near by, it had no evidences of any contamination. An inspection of these analyses shows that the deep weU waters were in excellent condition. According to the chemical analysis all of the shallow wells showed pollution. One gave a very favorable bacterial examination and may be considered good. The deep well waters contain less residue and an. softer than the shallow well waters. The results of our examinations would indicate that it is advisable for the farmers in the neighborhood of Champaign to use the waters from the deep driven wells in preference to the shallow wells. 12 •siiJBniaH Bad Good Good Good Good Bad -a ■tndoa (O iftOOOOOOO (DCO«0>t-M 1-1 T^1-i o CO ■lopni 1 + + + 1111 1 d ■0 TO M - 1 + 1 1 1 1 1 + 1 1 ■0 -D OT 1 1 caff] I ««C4N«rHi-lN •0 -0 OT 11 I NINI 1 •0 -0 JOd B!J3}0Ba oo o oooooo OTjiOi-l rH 1-1 s ■Ampjiiv too coco ■* ■* N CONOCOOCO lOCOlOOi-^CO CO-* CO-* CO CO N CO -< g S9}1BJ1!N coo HO 'd § N CO-* 00 COO COOOOOO -* 'cO N CO o o o o S3KJ1IN oo ON oo o COOOOOt- oooooo OOOOOO o ■pionininqiv HrH CD O ooeo'^coo OOWlONOSt- OHONOO 00 N •asj^ OtP NN t-O to rH o too-^ooco rHONOOOt- rHOOOWNi-l s CO -pomnsaoo uoSjCxq COO CO N oococotnooo NOONOJuii-i in CO onjiono COO CO H o CO E-eoNcocoo CO CO N ■H N spitos iBjox tr-V> COCO o t-COOOMCOCO SOrH'^rHinCO CO o jopo OO o oooooo o jopo NO o O^O-^MO * % a m Eh o o o o l-l 1^ o fr, m H Ph •sJiJBnisa •mdaa •jopni m ■0 -D T'O •0 -0 OT •a -0 13d s; js^io'ea •ijjnnBsiiv •S8}BJ}IN ■sejUHij •pioninmqiv •paninsuoo uaSSxo •aaijomo •spiios IB?ox ■Jopo •JOioo •Xjipiqjni "O t^'OD'O J; fa's I, •O'O ■d'C'O'O'O flea «» SSS^S^ M'C'C u) tH ^4 t4 tl t4 tl fl'd'O p 'O "ti "0 "ti "0 "O "P >. ^ ^ V V V V ^ V V O ^ V la O U3 O lO Ol £• o o o Ml I I ll + ll C^NMNC^NMC^M I J. I I I I I I I 111 + llllll I I II H i-IH H rH H THi-t T-IH OOOOOOOOtJIo NOSlNNCD'«* O 00 b-tO m CO H K- ^ NOOrHrHrHNWCOCON N^ O O (N O CO W ^ O OOOOOOOOOO OOOOOCQOOOO ON O CDtJ* W N OO'iKO t~ o:i030mmo)A0303oa CDCOCOCOWCOCDCDCDCO rHrHHrHrHHrHrHrHrH 17 mal residue on evaporation is less than 400., normal chlorine 10., normal nitrates 0.3. An excess over these figures would indicate surface contamination. GENERAL CONCLUSIONS. In those parts of the state where it is possible to obtaia a satis- factory water by means of driven or bored weUs, such wells are much to be preferred to the dug wells. This may be easily illus- trated by a little drawing. (See Pig. 1.). In a dug weU the casing smu-aw DUG welu SHALLOW BOftOHVELL. DEEP DUO WELL DEEP aOHED weu.'. Fig. 1. Driven Wells safer than Dug Wells. is either stone or brick, or, as in one well which I noticed, tile. Such a casing allows water to seep ia through its entire depth. We all know how water will flow through the sides of a hole from top to bottom, the hole draining the earth for some distance. A similar state of affairs will be noticed with dug wells. "Water flowing on the surface will carry with it any dirt or filth which may be near. In the case of the drilled, driven or bored wells, carefully cased, there is no chance for water to enter the well above the strainer. 18 All water wliieh enters such a well must therefore pass through a layer of earth of a thickness equal to the distance from the surface to the top of the strainer, the earth thus serving as a natural filter. Comparative tests of dug wells and driven wells show that the driven wells are frequently free from bacteria, though often carry- ing large quantities of soluble substances like salt and nitrogenous compounds, indicating thus the polluted origin of the water, but showing how the water has been filtered by passing through the earth. In some cases the drilled, driven or bored well, passes through a layer of earth through which water will not pass, and therefore the water supply must come from a considerable distance and will have a chance to become thoroughly purified during its passage through the earth. For this reason the deeper wells throughout the state, some of which have been analyzed in our series of farm well waters, are sho-\vn to be free from bacteria. We realize that in some sections of the state, possibly at Centra- lia, it is not practical to obtain water from either the driven, drilled or bored wells, because the deep drilled wells are salty, and the shal- lower wells enter a stratum of earth of such a character that there is not sufficient flow through the small opening of the strainer. In the latter cases the dug well is needed to give reservoir capacity, so that the water may accumulate between pumpings. In such cases we would suggest that a special reinforcement of the casing be used. Our suggestion is that the earth be excavated for four feet out- side of the regular casing, that a coating of water-proofed Portland cement be placed over this cas- ing (See Fig. 2), and that the bottom of this excavation, which should be at least four feet deep, be covered with sev- eral inches of water-proofed Portland cement, having a raised portion at the outer edge. (See Fig. 2). This will serve to divert the surface wa- ter away from the well, and it Fig. 2. Protection for Dug Wells. 19 Missing Page Binder Gaylord Bros. Inc. Makers Syracuse, H. Y. m. m 21, 1901 illiiil ■f' If m illl iiiiil I II