A PORE WATER SUPPLY FOR 
 
 BY G. BOUSCAREN. 
 
 A Paper Read before the Engineers Club of 
 Cincinnati, April 18, 1895. 
 
 The sources of water supplies for towns and cities may be 
 classified under the headings of Lakes and Impounding Reservoirs, 
 Springs, Underground Water and Water Courses. 
 
 All these waters have a common origin and come to us as 
 distilled water from the clouds, but this initial purity becomes 
 impaired from the instant of condensation. The rain-water 
 reaches the surface already impregnated with dissolved gases, and 
 with a variety of minute debris and germs which compose the 
 floating dust ever present in the atmosphere. 
 
 As it washes over the surface or penetrates into the soil, this 
 water becomes farther charged with earthy and organic matter, 
 and, it may be truly said, that absolutely pure water in the liquid 
 state does not exist in nature. This fact should be borne in mind 
 when speaking of the purity of water in connection with water 
 supplies. Purity , in this sense, meaning simply absence of 
 elements injurious to health, or harmful to purposes for which 
 water is used. It may indeed be surmised from the same fact, 
 that water chemically pure is not necessary or even desirable for 
 human consumption, except as a compounding ingredient of 
 physicians’ prescriptions. 
 
 Limpidity and freedom from an excess of the mineral salts 
 which constitute what is commonly called Hardness , are essen¬ 
 tial requisites in water used for cooking and washing and for cer¬ 
 tain processes of manufacture. For this reason physical purity 
 and softness have always been considered of great importance, and 
 until 25 or 80 years ago, the only qualities required for potable 
 water. Contamination by sewage was considered injurious to 
 
 <U i. VV 
 
 M 
 
_ 2 _ 
 
 health, and an abnormal proportion of organic matter objectiona¬ 
 ble, as a probable indication of such contamination. The presence 
 of infusoria and other small animalcula in water had long been 
 known ; but seems to have been considered as a necessary evil of 
 no great concern, as long as the diminutive size of the creatures 
 kept them hidden from view. 
 
 The discoveries of Pasteur and Koch, which laid the founda¬ 
 tion for the modern theory of germs in Pathology, sounded the 
 first alarm by revealing the danger lying in the omnipresence of 
 Bacterial life, and the researches of their numerous followers have 
 established, beyond reasonable doubt, positive evidences of the 
 indentation of cholera and typhoid fever through drinking water. 
 ^ The character of a water supply should therefore be considered 
 under three distinct aspects: Physical, Chemical and Biological. 
 In the light of modern investigations the latter would seem to be 
 by far the most important of the three, as regards their possible 
 influence on human health, and Bacteriological examinations are 
 now an indispensable adjunct to water works and sanitary 
 engineering. 
 
 Dr. Percy Frankland in his treatise on “ Micro-organisms in 
 Water" gives a list of 152 species of Bacilli and of 43 Micrococci 
 which have been observed in water. These lists are probably in¬ 
 complete, as new forms are being constantly discovered. Fortun¬ 
 ately 23 only of these species are known or suspected to be 
 pathogenic to man and animals, and their occurrence is rare as 
 compared with that of the harmless ones. 
 
 Water collected from the rocky slopes of mountainous water¬ 
 sheds into lakes and artificial reservoirs, is generally clear, soft and 
 wholesome ; provided the drainage area be uninhabited and uncul¬ 
 tivated or under perfect control. Liverpool and Manchester, New 
 York and Boston, are notable examples of such supplies. On the 
 other hand, the presence of only a few habitations on the drainage 
 area may be a dangerous source of pollution, and surface water 
 from well settled districts and cultivated lands, is entirely unfit 
 for domestic usage without artificial purification. 
 
 Spring water, when not charged with an excess of mineral 
 salts in solution, is generally preferred for drinking purposes. 
 When the water rises from a deep-seated source, as it generally 
 does in perennial springs, it is practically free from bacteria. So- 
 called “ wet weather" springs, the flow of which varies with the sea- 
 
 r 
 
sons, should be regarded with suspicion. They are generally fed 
 by surface water percolating through a thin stratum of porous 
 soil. Many well springs belong to that class. 
 
 Subterranean waters tapped through an impervious stratum 
 of rock or clay are, as a rule, identical in character with spring 
 water. Water courses derive their supply from springs and 
 .surface drainage. Their water partakes of the character of both: 
 spring water predominating during periods of low stages, when 
 the water is clear and more heavily charged with minerals; whilst 
 softness and turbidity, as a rule, characterize the flood water. 
 Owing to the variety of soils and formation traversed by large 
 rivers, and the blending of waters from many subsidiary streams 
 tributary to their flow, they should and do afford excellent sources 
 of supply when fed by the drainage of a sparsely populated region 
 and when not polluted by sewage ; even then, the power of self¬ 
 purification, aided by sedimentation in large settling basins, is 
 often sufficient to give reasonably pure water, provided that the 
 source of pollution be sufficiently remote to allow the process ot 
 self-purification to take place. 
 
 Such were the conditions generally prevailing in this country 
 before the formation of the numerous centers of population and 
 manufacturing which have naturally gravitated to the lines oi 
 transportation afforded by navigable rivers. For the time being, 
 many cities and towns derived satisfactory supplies from the 
 streams which carried their trade to the ocean, but with the 
 rapid fouling of these streams, incident to the growth of popula- 
 lation and to the practice of emptying untreated sewage into 
 them, it was only a question of time when the process of self-puri¬ 
 fication would become inefficient; the accession of organic matter, 
 with its hosts of bacteria from the sewage of the successive towns, 
 taking place faster than the destruction of the same by oxidation 
 and other natural agencies. 
 
 Such conditions now obtain for some streams of the Atlantic 
 slope. Careful analyses of the waters of the Passaic River at dif¬ 
 ferent points on its course, made by Dr. Charles D. Currier, show 
 an increasing number of bacteria in the down stream direction. 
 Outbreaks of typhoid fever have warned the people of their 
 danger, and they are being forced to seek purer supplies from the 
 mountains or from underground sources, or to have recourse to 
 artificial methods of purification. 
 
— 4 — 
 
 Many of the-streams of the Mississippi basin are fast ap¬ 
 proaching to the same status. The Ohio in particular, if not 
 comparable as yet to the Passaic River, has ceased to be a safe 
 source of supply at certain seasons of the year. The recurrence 
 of typhoid fever every year at the end of the period of low water 
 stages is an admonition which the city of Cincinnati cannot 
 afford to ignore. Louisville and St. Louis are leading us in this 
 respect. Although possessed of better works than Cincinnati, in¬ 
 asmuch as they take their water above all local source of contami¬ 
 nation, they are now seriously considering the problem of artificial 
 purification. 
 
 The first question that presents itself is: Shall we adopt 
 some other source of supply, or shall we abide by the river and 
 purify its water by proper treatment ? , 
 
 The geographical position of Cincinnati, at the center of a 
 thickly populated and agricultural basin of large area, is very 
 unfavorable to the application Of impounding reservoirs. The 
 necessary outlay to control the drainage of such reservoirs would 
 be enormous, and the character of the impounded water, in spite 
 of all precautions, would probably be such as to require purifica¬ 
 tion. 
 
 Springs of adequate capacity are not within reach. The only 
 alternative to the river is the underground water flowing in 
 the drift formations, down the valleys of Millcreek and the 
 Little Miami. Several suburban villages are now being supplied 
 from this source. The water is confined below a stratum of clay 
 and is probably free from .surface contamination. The water from 
 the wells at Norwood contain 26^ solid in 100,000 parts ; about 
 one-fourth of which is sulphates of lime and magnesia, and three- 
 fourths carbonates of lime and magnesia. It must, therefore, be 
 classed as hard water, and would require treatment by the lime 
 process for softening, but the main question which arises is that 
 of quantity. 
 
 The water in the wells at Norwood rises 46 feet above its 
 plane of confinement under the clay, and 90 feet above low water 
 in the Ohio River. On the occasion of the test made on April 
 24, 1894, when the deep well pumps were operated for sixteen 
 consecutive hours, and a draught of 500,000 gallons made during 
 that time from four wells, 20 feet apart, the greatest depression 
 observed in the surface of water in the wells was 7 feet 6 inches. 
 
These facts and conditions indicate an abundant source of supply 
 for the village, but would not justify the conclusion that it could 
 be depended upon permanently for a daily draught of thirty or 
 forty million gallons. Experience shows that the rate of motion 
 of subterranean waters through sand may plot exceed a few feet 
 in twenty-four hours, and that whilst a large volume of water 
 may be extracted rapidly from a sand bed, a long time may be 
 required to replenish it from the fountain head. The quantity of 
 water that can be regularly and permanently drawn from a sub¬ 
 terranean bed, must therefore be, to a great extent, a matter of 
 conjecture, until tested through a long period of time. 
 
 With this element of uncertainty before him, I believe that 
 no one with a due regard to the finances of the city would be jus¬ 
 tified in recommending the experiment. 
 
 If these premises are accepted, the conclusion is that we 
 must adhere to the river, and the question is : What means should 
 be employed to render its water wholesome at all times? 
 
 The principal methods that have been applied in America and 
 Europe for the artificial purification of water supplies; are settling- 
 reservoirs, filtering-galleries or wells, aeration, agitation with iron 
 scraps, chemical treatment: as by Clark’s lime process, mechanical 
 filtration in closed vessels, and sand filtration on artificially con¬ 
 structed filter-beds. A combination of two or more of these dif¬ 
 ferent methods is also employed. 
 
 Everyone knows that the proportion of solid matter carried 
 by the water of running streams bears a clo.se relation to the 
 rapidity of motion. The storage of water before its distribution, 
 in large reservoirs or pools where a state of rest or a sluggish 
 current would allow the suspended particles to drop to the bot¬ 
 tom, suggested itself naturally at an early date, and has been 
 extensively used as a process of clarification. These reservoirs 
 are indeed indispensable features of water-work plants supplied 
 from muddy streams, such as the Ohio, the Mississippi, and *the 
 Missouri rivers. Careful studies made in recent years by Euro¬ 
 pean investigators have demonstrated that the effect of storage is 
 not only to improve the water in physical appearance, but in 
 chemical and biological character as well; in reducing its contents 
 in organic.matter and bacteria. 
 
 Proskauer found the waters of the River Spree, which supplies 
 Berlin, greatly improved bacterially after its passage through 
 Havel lake. 
 
— 6 — 
 
 Tils showed that the water from the mountain stream which 
 supplies Freiburg is similarly improved after subsidence in the 
 reservoir. 
 
 Dr. Percy Frankland’s experiments with London water gave 
 the following results: 
 
 At the Grand Junction Company’s works— 
 
 First specimen from the Thames at the intake, 1,991 bacteria in 
 one cubic centimeter. 
 
 Second specimen from first small storage reservoir, 1,703 bacteria 
 in one cubic centimeter. 
 
 Third specimen from second small storage reservoir, 1,556 bacteria 
 in one cubic centimeter. 
 
 Fourth specimen from large storage reservoir, 464 to 368 bacteria 
 in one cubic centimeter— 
 
 Showing a gradual decrease in the number of bacteria as the 
 time of storage increased. 
 
 At the West Middlesex Company’s works— 
 
 Water at intake, 1,437 bacteria. 
 
 Water after going through two storage reservoirs, 177 bacteria. 
 
 At the New River Company’s works— 
 
 Water above reservoir, 677 bacteria. 
 
 Water from outlet of second reservoir, 183 bacteria 
 
 These beneficial effects are explained by the supposition that 
 the bacteria become attached to the solid particles and are carried 
 with them to the bottom, which is confirmed by the fact that a 
 greater degree of purification is always obtained with water con¬ 
 taining a greater amount of sediment or by the addition of a 
 coagulent, such as alum ; or by chemical precipitation, such as 
 takes place in Dr. Clark’s lime process. 
 
 On the other hand, the purification is at best incomplete, and 
 the time required for the subsidence of the smaller particles may 
 be so great as to require reservoirs of immense capacity. Further- • 
 more, the milky appearance of certain waters caused by the pres¬ 
 ence of fine clay, and the brownish color imparted by peaty soils, 
 cannot be removed by sedimentation of any practicable duration. 
 
 Infiltration galleries and wells built in sand or gravel on the 
 margin of rivers and lakes have also been used for the clarification 
 of turbid water, sometimes with success; as at Perth/Genoa, 
 Lyons, and Toulouse, in Europe, and at Waltham and Brookline, 
 
- 7 
 
 in Massachusetts. But in a great number of instances they have 
 been a failure, owing to the gradual silting of the filtering 
 medium. 
 
 Whilst the water thus collected is generally clear and im¬ 
 proved in appearance, it is quite frequently more heavily charged 
 with dissolved mineral salts, and often impaired by a strong taste, 
 which would indicate that a part at least of the water percolating 
 in the gallery comes from the ground of the adjacent valley and 
 hills and not from the river. Moreover, the straining process 
 does not separate the bacteria. After several years of operation 
 of the filtering gallery at Lawrence, the supply not only dimin¬ 
 ished gradually, but the quality deteriorated and became finally 
 inferior to the Merrimac river water, a greater number of bacteria 
 being found in the water after than before its passage through the 
 gallery. 
 
 Air, or more properly oxygen in this diluted form, is nature’s 
 great scavenger. What escapes the ravenous appetite of the liv¬ 
 ing is silently destroyed by this relentless agent. The refuse of 
 the laboratory of life is all burnt. 
 
 Oxygen is soluble in water at the ordinary temperature and 
 atmospheric pressure, in the proportion of about in volume, 
 and is ever at work, in collaboration with the fishes, the aquatic 
 plants, the infusoria and the bacteria, on the dead organic matter 
 carried by the waters of lakes and streams. 
 
 The motion of the water enhances its action by rendering 
 aeration more complete and bringing in closer contact the oxygen 
 and organic matter ; hence the beneficial effect of waves, rapids, 
 cascades, and waterfalls. So effective are these natural means of 
 aeration that the amount of oxygen in river water is rarely found 
 to vary much, unless the water has been seriously contaminated 
 by sewage. 
 
 In large masses of stagnant water, such as are found in 
 storage reservoirs of great capacity, relatively to the daily draught 
 made from them the case is different, and artificial aeration by 
 weirs, fountains and direct injection has been applied with good 
 results. Aeration is also necessary to render palatable, boiled or 
 distilled water. 
 
 Unfortunately, oxygen does not destroy the bacteria; its 
 action is auxiliary to theirs in perfecting the nitrification of the 
 organic matter upon which they feed. Aeration can, therefore, 
 
— 8 — 
 
 be considered only as a useful adjunct to a complete process of 
 purification, but insufficient of itself to accomplish the desired 
 result. 
 
 Since the discovery of Medlock, forty years ago, and the 
 researches of Bischof and Sir Frederick Abel, it has been known 
 that iron rust will remove a large proportion of the organic mat¬ 
 ter in water. It has also been shown by Dr. Frankland and other 
 experimenters that bacteria can to a very large extent be removed 
 from water by agitation with solids in a fine state of division. 
 These properties have been utilized in Mr. W. Anderson’s iron 
 process of purification, which has been in practical operation for 
 ten years at Antwerp, and on a large experimental' scale at the 
 Lee Bridge works of the Hast London Water Company. In his 
 experiments on agitation with solid particles, Dr. Frankland de¬ 
 monstrated that the separation of the bacteria from the water was 
 not permanent; that the bacteria were not destroyed but became 
 attached to the solid matter in a state of mechanical suspension, 
 and settled to the bottom. That their vitality was not impaired 
 was shown by the fact that they would soon rise from the sediment 
 and diffuse again in great numbers through the water. 
 
 In order to separate the bacteria by the Anderson process, 
 sand filtration must be resorted to, as practiced at Antwerp. The 
 process of itself must therefore be considered only as a useful— 
 but as will be shown hereafter—not an indispensable auxiliary to 
 sand filtration. Its principal advantage is a more complete re¬ 
 moval of the organic matter in the water. From ^3 to ^ parts 
 are removed. 
 
 The various methods of chemical treatment for softening 
 hard water, of which Dr. Clark’s lime process is typical, remove 
 also the bacteria in a manner similar to that of the Anderson 
 process. The bacteria become attached to the carbonate precipi¬ 
 tate and settle down with it, but again this disappearance is but 
 temporary; at the end of a few days they will reappear in large 
 numbers unless they are permanently removed with the precipitate 
 by filtration. There would be 110 occasion to apply such a pro¬ 
 cess to the Ohio river water, which is reasonably soft even at 
 low water stages. 
 
 Mechanical filtration is done in closed vessels, under pressure, 
 and at a rapid rate; generally with the addition of a coagu- 
 lent. Suitable appliances are used to wash the sand at frequent 
 intervals without renewing it. 
 
— 9 — 
 
 This system has found favor principally in America, where 
 many patents have been issued for various forms of filters. One 
 of the first in date is the Warren filter, invented by one of the 
 owners’of a paper-mill at Cumberland Mills, Maine, and applied 
 there in 1886 for the filtration of 12,000,000 gallons per day. • It 
 has been applied since to a large number of paper-mills and to 
 several town supplies, aggregating about 60,000,000 gallons per 
 day. A settling basin is generally used to remove the coarsest 
 matter; 75 to 100 pounds of alum to 1,000,000 ,;gallons of water 
 is used as a coagulent. The sand is washed with filtered water, 
 the frequency of washings varying with the degree of turbidity 
 of the water. From 2 to 5 per cent, of the filtered water is said 
 to be sufficient for the purpose of washing. The cost of a plant 
 appears to be about $10,000 per *1,000,000 gallons. 
 
 The purification of the Platte river water, for the supply of 
 Denver, Colorado, furnishes another example of mechanical filtra¬ 
 tion. The type of filters employed there is the invention of the 
 chief engineer, Mr. C. P. Allen. The daily output is 10,000,000 
 gallons. 
 
 The rate of filtration in mechanical filters is from 3,000 to 
 6,000 gallons per day per square foot of filter, which is from 50 
 to 100 times faster than the rate recommended by the best 
 authorities for gravity filtration on tillering beds. Mechanical 
 filtration removes practically all the visible suspended matter and 
 about one half of the organic matter in the water. 
 
 No systematic biological studies have yet been made to deter¬ 
 mine its degree of efficiency in removing bacteria, but from the 
 fact that satisfactory results in this respect only obtain in filtering 
 beds, with a comparatively slow and a very uniform rate of filtra¬ 
 tion, it may be surmised with a great degree of probability that 
 bacterial purification by this process must be very incomplete. 
 
 The history of sand filtration is interesting'in showing that 
 in his efforts to imitate nature in his work, the engineer may 
 build better than he knows. If Mr. Simpson could be with us 
 to-night, I think he could frankly say to you that in constructing 
 the first filter beds for the London companies, he had 110 other 
 object in view than the separation of the solid matter which gives 
 a turbid appearance to the Thames water. These filter beds had 
 been in use for a generation, contributing their part to the excel¬ 
 lent sanitary conditions which have made .London one of the 
 
10 - 
 
 healthiest cities in the world, before it was discovered that the 
 clarification of the water was the least important part of their 
 function, and that when properly operated they removed in a 
 very complete manner all the living organisms which are now 
 known or suspected to be man’s worst enemies. 
 
 Dr. Percy Frankland was, I think, the first one to establish 
 this fact in a conclusive manner, by the careful analysis which he 
 made of the London waters in 1885 and succeeding years. His 
 first experiments, covering a period of four months, showed the 
 average per cent, of reduction of number of bacteria by filtration, 
 for five of the London companies, to be 98 per cent. The daily 
 quantity of water filtered by the companies at the time when the 
 experiments were made was 70,500,000 gallons, the storage capa¬ 
 city of the settling reservoirs 516,000,000 gallons, the average rate 
 of filtration i t 7 q gallons per square foot per hour, the average 
 thickness of sand in the filter beds 3 feet 3 inches, the average 
 per centage of filter beds cleaned per month 74. Dr. Frankland 
 ranks as follows the principal factors in the efficiency of the 
 filter beds: 
 
 1st. Storage capacity for the unfiltered water. 
 
 2d. Thickness of sand in filter bed. 
 
 3d. Rate of filtration. 
 
 4th. Frequency of cleaning. 
 
 Dr. Frankland’s conclusions are confirmed in a general man¬ 
 ner by Mr. Gill in his report 011 the operation of the filter beds 
 for the city of Berlin, where the thickness of sand averages 2 feet 
 and the rate of filtration 3 gallons per square foot per hour. 
 Biological examinations of the water at the filtering station were 
 made daily, the efficiency in removing bacteria was found to vary 
 from 88 per cent, to 99t 7 o P er cent., according to conditions of the 
 beds and the regularity of operations. A uniform rate of filtration 
 and frequent cleaning of the beds were found to be the principal 
 factors of efficiency. 
 
 The work done since 1887 under the auspices of the Massa¬ 
 chusetts State Board of Health at the Lawrence Experimental 
 Station, has thrown a great deal of light on the subject, and 
 leaves no doubts as to the thoroughness of the purification effected 
 by this method. The experiments were conducted with water 
 from the Merrimac river, which receives the sewage of Lowell 
 about nine miles above the Experimental Station. Briefly stated, 
 
li¬ 
 
 the latest results and conclusions are as follows: 
 
 For rates of filtration varying from one-half to three million 
 gallons per acre per twenty-four hours, the number of bacteria 
 escaping through the filter never exceeded of i per cent. 
 
 The bacterial efficiency of old filters in 1893 was as good as 
 in 1892. 
 
 A low rate of filtration is safer than a high rate, but up to a 
 certain limit the rate has little influence. A high rate of efficiency 
 was obtained with the rate of 9,000,000 gallons per acre. 
 
 It is of great importance that the rate be uniform , and that 
 the beds be filled with water slowly after cleaning. 
 
 Contrary to what happens for the filtration of sewage, inter¬ 
 mittent and continuous methods are equally effective, which is 
 explained by the presence of oxygen in river water and its absence 
 from sewage. 
 
 The proportion of albuminoid ammonia removed averages 
 55 per cent. 
 
 The proportion of color removed averages 40 per cent. 
 
 Two explanations of the action of filter beds have been given ; 
 First: that of Dr. Koch and other German authorities, which at¬ 
 tribute the principal effect to a surface layer of slime, the action 
 being partly mechanical and partly biological. According to this 
 theory a shallow depth of 1 foot only of fine sand would be useful. 
 Second: that of the Massachusetts State Board of Health, which 
 considers the action as being entirely biological and due to aerobic 
 bacteria adhering to the grains of sand. This theory seems to be 
 sustained by the fact that a greater depth of sand increases the 
 efficiency, and that a varying rate of filtration, which would tend 
 to detach the bacteria from the sand, decreases it. 
 
 The example of London and Berlin has been followed by 
 many other European cities who now filter their water supplies. 
 A partial list of them, as well as of other large cities which do not 
 filter their water, is given by Mr. Wm. Hazen in the paper read 
 by him on November 21, 1894, at a meeting of the Boston Society 
 of Civil Engineers. It is as follows: 
 
—12 
 
 Filtered River Supplies. 
 
 City. 
 
 Popula¬ 
 
 tion. 
 
 Gallons Daily, 
 
 Source. 
 
 total. 
 
 Capita. 
 
 Loudon (7 companies) 
 
 5,030,000 
 
 190,000,000 
 
 38 
 
 Thames and Lea 
 
 Berlin . 
 
 1,606,000 
 
 26,000,000 
 
 16 
 
 Spree 
 
 St. Petersburg. 
 
 960,000 
 
 39,000,000 
 
 40 
 
 Neva 
 
 Hamburg. 
 
 583,000 
 
 32,000,000 
 
 53 
 
 Elbe 
 
 Warsaw. 
 
 500,000 
 
 6,000,000 
 
 12 
 
 Vistula 
 
 Breslau. 
 
 335,000 
 
 7,000,000 
 
 22 
 
 Oder 
 
 Rotterdam. 
 
 240,000 
 
 13,000,000 
 
 54 
 
 Mease (Rhine) 
 
 Magdeburg. 
 
 200,000 
 
 5,000,000 
 
 24 
 
 Elbe 
 
 Filtered, 
 
 Not From rivers. 
 
 Amsterdam. 
 
 515,000 
 
 10,000,000 
 
 20 
 
 Dunes and Canal 
 
 Liverpool. 
 
 815,000 
 
 22,000,000 
 
 27 
 
 Impounding Reservoir 
 
 Bradford. 
 
 364,000 
 
 r 2,000,000 
 
 33 
 
 Impounding Reservoir 
 
 Dublin. 
 
 327,000 
 
 18,000,000 
 
 55 
 
 Impounding Reservoir 
 
 Unfiltered Ground Water. 
 
 Paris. 
 
 Vienna. 
 
 Buda Pestli. 
 
 London (Kent Co.). 
 
 Leipzic. 
 
 Munich. 
 
 Dresden . 
 
 Cologne. 
 
 Frankfort. 
 
 2,500,000 
 
 1,000,000 
 500,000 
 460,000 
 360,000 
 300,000 
 280,000 
 255,000 
 186,000 
 
 J 53,000,000 
 t 80,000,000 
 23,000,000 
 32,000,000 
 • 16,000,000 
 5,500,000 
 11,500,000 
 6,000,000 
 11,500,000 
 6,700,000 
 
 21 
 
 32 
 
 23 
 
 65 
 
 35 
 
 15 
 
 38 
 
 21 
 
 45 
 
 36 
 
 Springs (Domestic) 
 Seine (Public) 
 
 Springs 
 
 Wells by the Danube 
 Wells in Chalk 
 
 Wells 
 
 Springs 
 
 Filter Gallery 
 
 Wells by Rhine 
 
 Wells and Springs 
 
 Unfiltered Surface Water. 
 
 Manchester. 
 
 963,000 
 
 24,000,000 
 
 24 
 
 Impounding Reservoir 
 
 Glasgow. 
 
 794,000 
 
 50,000,000 
 
 64 
 
 Loch Kathrine 
 
 The first filter beds in the United States were built for the 
 
 town of Poughkeepsie in 1870 by J. P. Kirkwood, after a voyage 
 to Europe undertaken for the special purpose of studying the 
 results of sand filtration. 
 
 This plant remained, I believe, for a number of years as the 
 only representative of its kind in this country, until the publica¬ 
 tion of the Lawrence experiments had again drawn the attention 
 of engineers to the merits of the system. Four small plants have 
 been built lately at Lawrence and Nantucket in Massachusetts 
 and at Ilion and Hudson in New York. 
 
 A practical test of the sanitary effect of sand filtration is 
 found in the marked decrease of the death rate, which has in¬ 
 variably followed its introduction, and the comparative immunity 
 of cities who filter their water supply, from epidemics of cholera 
 and typhoid fever. 
 
 9 
 
13 
 
 Dr. Billings gave a striking illustration of this fact in his 
 address before the medical society of the District of Columbia 
 October 24, 1894, which I quote for the benefit of those who may 
 not have read this very interesting paper. 
 
 “ Hamburg and Altona form one continuous building area 
 so that it is impossible for a .stranger to see any difference in the 
 character of the buildings or the surroundings. * * * 
 
 The two cities are, however, quite distinct in their form of gov¬ 
 ernment, and what is more important to us, in their water supply. 
 * * * Hamburg took its water from the River Elbe above the 
 
 town, though not above tidal influence, and supplied it unfiltered, 
 while Altona took its water from the same river below the town, 
 where it was highly polluted with sewage, but filtered it through 
 sand filters before distributing it to the people. 
 
 “In the great cholera outbreak in 1892 the cases occurred 
 almost exclusively in Hamburg, and in a map of the two cities, 
 on which the cholera cases are located by red dots, I saw the 
 boundary line between Hamburg and Altona almost as distinctly 
 marked by the dots as if it had been shaded in for that purpose. 
 It is true that there were cases in Altona, but inquiry showed that 
 in almost all these cases the sick had either drunk Hamburg water 
 or water taken directly from the river. 
 
 “One of the most remarkable bits of evidence is furnished by 
 a small court, the houses about which are occupied by several 
 hundred people. This court is in Hamburg, on the boundary line 
 between it and Altona, but for some reason it was not supplied 
 with water from the Hamburg works but from those of Altona. 
 Now on the map just referred to, there are no red spots on this 
 court, although they surround it on three sides, the fourth, or 
 Altona side, being free.” 
 
 An essential condition of the successful operation of filtering 
 plants, is that they should be properly managed and cared for. 
 This fact is now fully recognized and the European plants referred 
 to are all placed in the hands of able engineers and under constant 
 bacteriological inspection. 
 
 The large area ot bottom land extending for several miles 
 along the north shore of the Ohio river, above the mouth of the 
 Little Miami, affords a suitable location for filter beds, and the 
 extensive sand bar's which line the northern bank of the river in 
 the same vicinity would permit the use of straining cribs such as 
 have been applied lately at several places 011 the Allegheny river. 
 
14 - 
 
 The preliminary clarification of the water before filtration 
 is generally done by means of settling basins. If the same result 
 can be accomplished by straining cribs, a large saving in the cost 
 of the plant would be realized. With a sufficiency of duplicate 
 machinery the storage of a large quantity of water is quite un¬ 
 necessary, nor is it even desirable, the rapid development of 
 bacteria from the few germs that would always escape from the 
 filters, making it almost essential that the water be consumed as 
 soon as possible after filtration. The restoration of the Eden park 
 reservoir and its adaptation to service as a pure water basin would 
 be all the outlay required in the way of storage. 
 
 It is apparent that the problem of a pure water supply can 
 be solved by the City of Cincinnati quite within her means. 
 
 The question may be asked, Why should the entire water 
 supply of the city be filtered, when scarcely one-third is used for 
 domestic purposes? It does seem extravagant to furnish filtered 
 water for running elevators and for sprinkling streets and lawns, 
 but it would probably be quite as expensive to provide*the double 
 system of mains required for the delivery of two kinds of water. 
 The City of Paris has done so; with her it was not a matter of 
 choice but of necessity. Her example has not been followed. 
 Moreover, beyond the question of economy, there are good reasons 
 why a double system of distribution should be avoided, ist. There 
 would always be a suspicious liability of an open connection 
 between the two systems of conduits. 2nd. Experience shows 
 that many people will drink the water which happens to be the 
 most convenient, regardless of consequences. 
 
 This last objection applies with equal force to the systems 
 which would leave the purification or sterilization of drinking 
 water to private initiative, each family and establishment solving 
 the problem in its own way, or buying sterilized water from some 
 private company making it ^ business to furnish it. 
 
 Three methods of private treatment have been proposed and 
 applied on a more or less extensive scale. The one more gener¬ 
 ally used is filtration. Innumerable forms of filters have been 
 invented and introduced for domestic usage. A common feature 
 to all of them is that the water is made to percolate through a 
 porous substance, which separates all the solid particles which 
 can not pass through its pores. The particular nature of this fil¬ 
 tering medium and the mechanical arrangement to facilitate clean- 
 
— 15 — 
 
 ing being the principal points of differences. Sponge, mineral 
 wool, sand, vegetable and animal charcoal, coke, spongy iron, 
 sandstone, pumice stone, biscuit porcelain and other artificial 
 stones have been used, and generally yield bright, clear water, 
 agreeable to the eye and to the taste. The separation of the bac¬ 
 teria is far less satisfactory, as has been shown repeatedly by 
 careful biological examinations made at different times and places 
 by different experimenters. 
 
 The experiments of Dr. Percy Frankland with 6-inch layers 
 of sand, iron sponges, animal and vegetable charcoal and coke, 
 show, that while with a slow rate of filtration the separation of 
 the bacteria at the beginning of operations is almost perfect, the 
 efficiency gradually deteriorates with time, until, if the experiment 
 is prolonged sufficiently, more bacteria are found in the water 
 after than before filtration. The experiments made at Lawrence 
 with a greater depth of sand, show, however, that sand filters, if 
 properl}" constructed and operated, may preserve an efficiency of 
 99% almost indefinitely. 
 
 The Pasteur filters, made of biscuit porcelain, and the Berke- 
 feld filters, made of baked infusorial earth, are admitted to be the 
 most reliable. They yield in the first instance sterile water, and 
 will continue to do so for a length of time, varying with the 
 quality of the porcelain and the character of the water, from one 
 to four weeks; but Frendereich’s and Nordtmeyer’s experiments 
 show that the pores of the porcelain are being gradually filled 
 during this time with colonies of bacteria that will finally appear 
 in large number in the filtered water. The safe usage of these 
 filters require, therefore, that they should be carefully washed and 
 sterilized every week. The conclusion to be drawn from all these 
 facts is, that whilst domestic filters have been and will continue 
 to be very useful appliances when operated with intelligent care; 
 their efficiency is dependant on such constant attention and watch¬ 
 fulness that they are not a safe and practicable means of purifica¬ 
 tion in the hands of the general public. 
 
 Boiling and distilling have also been suggested for the steril¬ 
 ization of drinking water. It is well known that all living germs 
 are destroyed at the temperature of boiling water under ordinary 
 atmospheric pressure maintained for 15 or 20 minutes. The 
 practice of boiling their drinking water is found to a very large 
 extent among the most intelligent part of communities whose 
 
16 — 
 
 water supply is one of doubtful purity; of late years it has come 
 to be a standing rule in many households in Cincinnati. Distilled 
 water is also as a matter of course sterile, and is used very gener¬ 
 ally on steamships equipped with a distilling apparatus, to avoid 
 the necessity of carrying a large supply of drinking water—-always 
 liable to deterioration during a long voyage. 
 
 Theoretically, boiled and distilled water should always be 
 biologically pure, practically they are rarely so; on account of the 
 precautions necessary to preserve their initial purity being .seldom' 
 taken. All bacteriologists agree to the fact that bacteria will de¬ 
 velop almost as rapidly in boiled and distilled water as they would 
 in any other. The introduction of a few colonies in the stored 
 water would, therefore, suffice to populate it thoroughly in the 
 course of a few days, and this inoculation is extremely difficult to 
 avoid, especially if the water is aerated after boiling, as it .should 
 be to make it palatable. 
 
 The principal objection to these methods of purification, how¬ 
 ever, is their great cost. If we estimate on the utilization of 
 10,000 heat units per pound of'coal burnt in the heaters—which is 
 probably too high—one pound of coal would bring about 66 pounds 
 of water to the boiling point from an initial temperature of 6o°; 
 i,ooo gallons would therefore require i x i,ooox =126 lbs. of 
 coal, costing, at $1.75 per ton 1 VVoV 6 — $°- 11 • 
 
 For distilled water; estimating on the most improved form 
 of apparatus, where the heat of condensation is utilized to the 
 utmost limit practicable, the cost of fuel would be at least double, 
 viz.: 22 cts. per 1,000 gallons. If we should add to these figures the 
 cost of aeration, of labor, of delivery, of repairs, of interest on cap¬ 
 ital, of depreciation of plant, &c., we would arrive at such prices 
 as would perhaps be paid willingly by the rich, but which would 
 be prohibitor} r for the great mass of the population, where the lib¬ 
 eral use of water should be specially encouraged and wholesome 
 water made a cheap luxury. The only practical solution of the 
 problem seems to be the purification of the entire city supply by 
 sand filtration.