UC-NRLF B 3 111 3bS SANITATION OF CITIES . WILLIAM -L*D 1 OLIER AND STAFF OF THE SANITATION CORPORATION NEW YORK CITY Engineering Library G-5 Copyright, 1921, by THE SANITATION CORPORATION NEW YORK ' WILLIAM L. D'OLIER CONTENTS CHAPTER PAGE I GENERAL CONSIDERATIONS 3 II THE CITY PLAN AND THE SANITARY UTILITIES . . 15 III WATER SUPPLY AND REMOVAL OF SEWAGE ... 23 IV THE PURIFICATION OF WATER SUPPLIES .... 43 V THE SEWERAGE SYSTEM 57 VI THE SEWAGE TREATMENT PROBLEM 63 VII THE BIOLOGICAL TREATMENT OF SEWAGE .... 73 VIII DIFFICULT PROBLEMS FOUND IN TREATING SEWAGE . 83 IX THE MECHANICAL TREATMENT OF SEWAGE ... 89 X THE PURIFICATION OF SEWAGE 97 XI DEVELOPMENT OF COMMERCIAL WATERWAYS AS A SANITARY MEASURE 105 XII HIGH PRESSURE FIRE SERVICE in XIII CONCLUDING REMARKS 117 7881S2 WHICH-WILL-NE-BUY? J LLl NO IS STATE BOMIO of H EALTH - CARTQONN-4 ONTHE-5ANITY-OF-HJS-CHOICE-THE HE^LTH-OF-HIS-CITY-WIUL-DEPEND. THE SANITATION OF CITIES CHAPTER I GENERAL CONSIDERATIONS BENJAMIN FRANKLIN in one of his wise sayings reminds us that the choice of a good whole- some situation to fix a dwelling in is a very serious affair, especially as not only the comfort of living but even the necessaries of life depend in great measure upon it; since a family frequently sick can rarely, if ever, thrive. The truth of this and the wisdom of his advice are obvious. Sanitation is a broad subject, and in the present age is especially the problem of the city. Civilization is the child of the city, and the true measure of social advancement is made manifest particularly in the comfort, health and prosperity of the inhabitants of cities. The an- cient municipality encircled by its strong walls reveals civil and social conditions controlled by power and served by slavery. Many cities are written large on the pages of history which are illumed thus with deathless glory. Babylon, Nineveh, Memphis, Jerusalem, Troy, Athens, (Seneral Conefoeratione and Rome are names each of which is invested with an infinite charm, both of grandeur and pathos. But we of this utilitarian age are usually forced to turn from their story, notwithstanding its enchantment, with the feeling that it offers little to guide us, beyond affording lessons of what to avoid. History and archaeology reveal abundant data concerning cities, their growth and problems, and present the drama of their civil and political experience, but teach very little that is helpful about their sanitation which, since it is related directly to human life, must have been always of primary importance. We are told of wars, of victories and disasters; of arts triumphant over social degradation; and of slavery. Ancient literature, immortal, or as nearly so as anything human can be, reveals the men of bygone ages who seem still to live and speak. But of sanita- tion there is little to be learned from ancient history and literature, save only the lesson taught by its absence. The strength of cities and of nations was sapped and undermined, often when facing relentless enemies without the walls, by the diseases within resulting from ignorance and incapacity to provide for sanitary needs. In these ancient cities war carried off its thou- sands, and pestilence its tens of thousands. The manifold diseases described under the names of plague, black death, cholera, typhoid, typhus, Sanitation of Cities etc., were due to insanitary conditions; unclean- liness was the predisposing and most powerful cause meaning by this the accumulations of ANCIENT EUROPEAN CITY Showing the method of sewage disposal obtaining in this city at that time. Waste matter pouring from the buildings into a canal decaying animal and vegetable matters around human habitations, and the saturation of the soil with filth. Nor were the cities of antiquity the only sufferers from these visitations. Athens had reached her meridian and her sun had set; Rome had passed into ruin, and yet the progress of pestilence advanced even into our own age. The millions of deaths that history ascribes 6 (Beneral Consiberations to diseases and epidemics, due principally if not altogether to the lack of sanitation, far exceed all the losses of life through the ages caused by wars. It has taken centuries for our race to learn that our greatest enemy bears no sword or stave, but enters our camp unobserved, like a spy a re- lentless foe, hidden within and fostered by the neglected rubbish and offal that comes forth from his lurking place without warning, to strike the human body itself, which cannot be defended effectively against the onslaught of epidemic 5 pestilence when thus attacked. < u The sanitary modern city has been well de- scribed by an ingenious writer as the result of a z number of contributing developments which have f 1 I*M ^ created a unit that may reasonably be compared > j with the human organism; with its skeleton, the v^ yu city streets; the water distributing pipes and sewers, its arteries and veins. Through the arteries, sp called, courses the water which is the 2 life-blood of the community; and through the so- fc called veins, the sewers, pass off the liquid mat- Jj ters contaminated in the processes of the bodily functions. To carry the simile further, the heart might be compared to the waterworks pumping plant, and the kidneys to the sewage disposal system. Thus the city may be looked upon as an organism, as well as a social unit, having its organic life and requiring for its normal existence ftbe Sanitation of Cities the healthful performance of its various func- tions. The present century is especially the age of CROSSNESS, LONDON, ENGLAND Sewage pumping station cities. The urban population of the United States in the thirty years from 1880 to 1910 in- creased from 29.5 to 46.3 per cent, and in the last decade alone there has been an increase of more than 35 per cent. People prefer to live in cities primarily because of better facilities for earning a living from trade and industry, and because of better opportunities for social enjoy- ment and recreation. Secondarily, because the conveniences of life are afforded in greater measure than in rural communities. The industries and commerce that are the physical support and wealth of a city are largely dependent upon means of communication and transportation by rail and by water, and upon 8 u 03 JD h " H . Z JH ^ U- U v o ^g 5 ^ v ^ ^ ^ ^ O v^: III >. ^-o U K o> o g-S^ <* CQ o 2 60 &c c c '^ si I" 9 Sanitation of Cities the existence of extensive tributary areas from which raw materials are obtainable, as well as abundant supplies of food; and further, upon sanitation and a naturally healthful location. Before the introduction of railways the great cities of the world depended in almost every case on water transportation for their prosperity; nor has the railway greatly altered this. Access to the ocean-borne commerce of the world and to river transportation is the greatest possession of a city. With the growth of cities there has come a great increase in the mutual interdepend- ence of their inhabitants and a more general recognition of the value of organized activity in municipal life. In modern times an essential por- MIAMI, FLORIDA View of a southern park tion of the city's care is preservation of law and order, safety from fire, provision for public works and their upkeep such as water supply, pave- 10 (general Conefoeratione ments, sewerage, sewage disposal, wastes disposal, parks, public baths, and various other social conveniences. But it is only in recent years that serious efforts have been made toward correlating these activi- ties, thereby obtaining not only a more economi- cal plan in the outlay of public funds, but also a much higher efficiency. It is self-evident that street layouts should be related not only to the needs of traffic and the marketing of real property, but also with regard to the most efficient and economical design for the public utilities, such as water supply, surface drainage and sewers. It is no less evident that the needs of water purification and methods to be em- ployed should be considered in relation to sewage treatment and disposal and that garbage dis- posal and sewage disposal should be considered together. There are many other questions that are related and should be given consideration at the same time, even if not intended to be pro- vided for together, so that when provided for they may fit in as harmonious parts of a well- planned municipal unit; and the construction of the parts may be carried on progressively, al- ways aiming at a future result by practical means, within the reasonable capacity and resources of the city. The "reform of the city plan" would be a bet- ter term perhaps than "city planning/' which has 1 1 Sanitation of Cities of late gained such currency as to become fashion- able. It is seldom that new cities are built from the ground up. Occasionally there is an op- PARIS, FRANCE River Seine, near the Louvre portunity for a L'Enfant to lay out a great capital, but this is seldom. The work of the city planner is chiefly the work of the reformer and his work in these days is very necessary. Existing cities require replanning in many ways in order that they may be made sanitary, convenient, efficient and beautiful. The sites of many cities owe their selection to the avenues of trade and commerce, and their street design prin- cipally to the land speculator.. A veritable wil- derness may in a few years become the center of a vast population, a metropolis, with its people gathered from every quarter of the earth. Sanitation is seldom considered at the begin- 12 (Seneral Considerations ning of such a city and, as its need becomes im- perative, makeshift design is resorted to, usually offered by unskillful or unqualified persons. Of the American cities it may too often be said that they "just grew/' were not founded by any one in particular, and had no city plan. Hence it is that existing streets do not properly provide for existing not to mention future traffic, and that in the layout of these streets insufficient con- sideration was given to the requirements of sewer- age and drainage. In some cities, where much money has been expended on streets and architectural embellish- A TIDAL STREAM ON LONG ISLAND Undeveloped and insanitary but not unhappy looking. Oyster beds nearby caused typhoid fever on several occasions ments, the sanitary condition of the river or harbor, upon which the wealth of the community primarily depends, has been neglected and the 13 Sanitation of Cities water has already become, or is rapidly becom- ing, grossly polluted. Plants for high grade sewage treatment have been introduced at great expense by some cities which do not even purify their drinking water a far greater necessity since no possible grade of sewage treatment can render river water, mixed with sewage plant effluent, desirable or really safe for human con- sumption. There frequently is a general absence of scale, or perspective, in these improvements, and with the best intentions in the world the re- sult is much wasteful expenditure. The principles that should control in the "re- form of a city plan/' particularly those relating to sanitary requirements, are of interest to every- one. Much has been written by experts on this subject, especially by English and European en- gineers and architects, and even by some of our own countrymen. Unfortunately these writings are scattered through many pages of the technical magazines, sometimes in a foreign language or in expensive text books not readily available to the lay reader for whom this paper is primarily intended. CHAPTER II THE CITY PLAN AND THE SANITARY UTILITIES IT is obvious that the street plan of a city should not only provide for traffic, and the various other more apparent purposes for which streets and highways are provided, but also for economy and efficiency in the installation and operation of the important sanitary utilities water supply and sewerage in order that the water may travel the shortest distance practicable from the main supply to the consumer, and the sewage the shortest practicable distance to the point of disposal without such loss in velocity as would cause deposits in the sewers. But the city plan- ner, whose mind is usually occupied with city beautification, and the needs of street traffic, often overlooks these sanitary improvements; and, in reforming or improving the street plan, often neglects the opportunity to design the new streets with the view of more efficient sewers, that would afford a much more rapid concentra- 15 i6 Gbe City plan anb tbe Sanitary TUtiUtte* tion of the flow, and lead the sewage to the main outfall before the suspended solids had time to pass into solution. The first principles of street design require the proper accommodation of these utilities. This indeed, should be considered as one of the main objects, if not the most important object, to be obtained by the redesign and improvement of the street system. It is not necessary in this connec- tion to go into detail concerning the architectural and engineering features, as to width, etc., of streets. The city planner will not neglect to take proper care of this feature of his work. The street plan should be economical, and con- form to the topography, with the lines made as simple as possible. Various forms of plans are recognized as the radial and circumferential, the rectangular or "gridiron plan/' and a combina- tion of these plans. In some instances, plans are used greatly resembling those of European cities of the Middle Ages, which have in recent years been replanned with circumferential streets, re- placing old lines of city walls now removed. In others, new streets are controlled mainly by prop- erty lines. But whatever the scheme or form, the effect on sanitary utilities should be given primary consideration; and before the improved street plan is fixed upon, the design of the sanitary system should be completely worked out by ex- perts, and the proposed plan amended, if neces- JS "? c o c . r3 03 o I 18 al of Sewage treated, or purified, in preparation for human con- sumption, the answer involves the further ques- tion "How impure, or polluted, is the source of BIRMINGHAM, ENGLAND Outfall of treated sewage from treatment plant. The treated sewage from this plant is greater in volume than the ordinary flow in the river into which it is discharged and is much purer supply?" If on the other hand, it is asked to what extent sewage should be treated, the answer involves a reply to the question "Will the efflu- ent by any means find its way into the source of a water supply?" Obviously, if a source of supply is free from all danger of sewage pollution, it need not be treated to remove the danger of causing diseases which commonly arise from this pollution. 25 to c JO 4> s- C c 2I| ^^ T3 ^ oa CQ < 2 > c '^ o p 03 "5* OS *T3 1^ 03 ca Mater Supply anb IRemovml of Sewage There are other reasons, however, on account of which treatment may still be required such as hardness, discoloration, etc. It is no less evi- DAYTONA, FLORIDA Foot bridge across the Halifax River, immediately below R-W sewage treatment plant into which the treated sewage is discharged dent that sewage treatment will need only to be provided for the purpose of keeping a waterway in a sanitary condition, if the water therefrom is to be used for, or find its way into, a source of water supply. The treatment of water, for water supply pur- poses, is one thing, and the treatment of sewage quite another. On this subject there is much mis- understanding in the public mind. Many people, not accurately informed, appear to think that the treatment of water for drinking, and the "puri- fication" of sewage to secure practically the same grade of purity, are equally feasible and quite simple. There could be no greater mistake. 27 Sanitation of Cities Water for drinking purposes usually carries but little organic impurity, in comparison with sew- age, and is very readily purified, and the plants FITCHBURG, MASSACHUSETTS A large Imhoff tank sewage treatment plant provided for the purpose are reliable and efficient. Sewage practically cannot be purified by any known process that is reliable. Beyond a reduc- tion in suspended matters, and a partial oxida- tion of dissolved solids, the treatment of sewage produces negative results. When there is danger of sewage pollution, and no other source of water supply is available, water purification affords about the only solution of the problem. It should be understood that sewage treatment can not replace water purification; but water purification will give reasonable protection from water-borne disease-germs, whether we have sewage treatment or not. Therefore, the real purpose of sewage treatment should usually be 28 c O) CO g H g * 1 } i> W) ! I | C^ u I ^ to 11 II DD ^^ > a 1 o U Sanitation of Cities limited to the prevention of a nuisance in the vicinity of the discharging sewage effluent, in the waterway which it enters. It is seldom proper or advisable to use water that contains sewage as drinking water, even if treated by a purification plant. It is unwise to treat sewage with a view to turning it into drinking water. Water purification should be as perfect as pos- sible, as this is the only real protection against water-borne diseases which may lurk in any natural surface water. Sewage treatment should be as simple as possible, and the extent of treat- ment no greater than sufficient to maintain satis- factory sanitary and aesthetic conditions in the MIAMI, FLORIDA Royal Palm Park, Biscayne Bay local waterway receiving the sewage. Much money has been wasted on elaborate sewage treatment plants, designed to attempt the "puri- 3 Gbe Sanitation of Cities fication" of sewage, or protect water supplies "lower down" on a river, to an extent uncalled for by local requirements. Sewers must of necessity discharge into rivers -they will always do so and rivers should be avoided if possible as sources of water supply, but kept in such sanitary condition that fish life will be protected; and there should be no visible nuisance. Further protection than this is seldom called for, or justifiable. A simple and reliable, positively operating sewage disposal plant, designed to meet the actual sanitary needs, is always better than a compli- cated plant designed to give a greater degree of treatment than is necessary, that within a year or two may be abandoned because of operating difficulties, or a higher degree of skill required in management than is ordinarily available. In the selection of water supplies, quality and quantity of water must be considered first, then the expense of development, etc. The sources of the water supplies used by most of the larger American cities are shown by the following state- ment: Wells of various kinds 40 per cent Ponds, lakes and springs 25 Rivers and streams 24 Mountain streams 1 1 Too " It has been estimated that about 4000 Ameri- can cities and towns are provided with public 32 TKHater Supply anb IRemoval of Sewage water supplies. Most of these are relatively small installations, and the majority obtain their sup- plies from wells. The amount of well water ob- tained in some places is remarkably large one supply from the sands of Long Island yielding daily up to 100,000,000 gallons, with a supply per square mile of 750,000 gallons. Water taken from wells is usually excellent, clear, pure and colorless, requiring no purifica- tion; but it may be hard, and some well waters contain various inorganic matters in solution which cause a slight trace of color. This, as well as excessive hardness, can be removed by ap- propriate treatment. Water supplies obtained from deep wells seldom, if ever, are in danger of ORMOND, FLORIDA View of a park sewage pollution, even where the water-bearing sands are located within fairly populous districts; as is the case with the Long Island supply before 33 Sanitation of Cities mentioned, on the drainage area of which dwells a large population, in several towns of consider- able size. Lake supplies are much more subject to pollu- tion than well supplies and in almost every case sanitary safety demands water purification where water from these sources is used for human consumption. Buffalo, Cleveland, Chicago, De- troit, Duluth, Erie, and Milwaukee, as well as many other cities and towns, use lake water. Long intakes in many instances are provided at great cost, to obtain supplies far enough from the shore to avoid local pollution. The Great Lakes receive the sewage and storm washings from many urban surfaces, and millions of people depend upon the lake water for drink- ing and other purposes. To improve waterfront property, and prevent local nuisance, sewer out- lets are also extended outward from the shores; so that a race seems to be on between the extend- ing water intakes and the sewer outfalls. Ex- perts are employed to select locations for water intakes, at points where prevailing winds and currents will not carry the polluted water from the city streets and sewers. In some places, the cry goes up that the sewage should be so com- pletely treated as to prevent all danger of pollu- tion entering the water supply, and methods of treatment are recommended which, notwith- standing their great cost, when installed, fail to 34 Mater Supply anb 1Remo\>al of Sewage accomplish this purpose. For, as has been often pointed out, no method of sewage treatment af- fords a means capable of turning sewage into an acceptable drinking water. BALTIMORE, MARYLAND Settling or septic tanks in operation Impounding reservoirs are usually necessary with any system of water supply other than a source derived from driven wells, or from large lakes. Storage greatly decreases the danger of bacterial pollution, especially from pathogenic germs; affords opportunity for suspended mat- ters to settle; and enlists the bleaching effects of sun and air in the removal of any undesirable color. Its main purpose, however, is to provide an adequate reserve supply; especially where the spring and fall rains are heavy and the rainfalls of the other seasons are insufficient for the pe- riods in which they fall. 35 SO c i H O II Si c O 36 Mater Suppl? anb IRemoval of Sewage According to most authorities, it is a well estab- lished fact that sewage bacteria, especially of the B. coli group, die off rapidly in clear cold water, while the aerobic bacteria, natural to water, are not so adversely affected, and remove any trace of organic pollution which may chance to be present. The number of bacteria present is evidence, or even a direct index, of the amount of bacterial food supply existing in the water and, if the storage is properly regulated by successive basins, a natural purification takes place, which often renders further treatment unnecessary. For example, at Lawrence, Mass., the bacterial re- duction in a two weeks' passage through the city reservoirs exceeds 93 per cent on the aver- age. At Washington, D. C, in one week's passage through, the reduction exceeds 90 per cent, and at the Boonton reservoir, a part of the supply of Jersey City, N. J., a six months' storage, or pas- sage through, effects a removal of 99 per cent of the bacterial pollution. There is, however, a limit to the time during which storage is advisable. If it is too long, stagnation occurs, especially in the bottom lay- ers of the reservoir, accompanied by various growths common to stagnant ponds organic matter is deposited and dissolves, bacteria in- crease, as well as other low forms of life which give a bad taste to the water, and deprive it of dissolved oxygen. Aeration and filtration are 37 V) 2 I OJ _C fc-sl O ra c III O 1-1 S 8-- O - c C3Q * t IS- o = rt Q" ^ >- J "E^ w ^ 2 E S^ 5 -I < S ^ Du ^.S ^ c ^c ci ' o u- I c OJ O 4 Wlater Supply anb IRemoval of Sewage sewage of cities, and the one thing which remains to be done is to see that sewage wastes are made unobjectionable before their discharge. This is practically all that any community should be re- quired to do. The ideal state of affairs toward which Ameri- can sanitarians are working, is to permit all cities to discharge their sewage into the nearest stream, but require them first to treat it to a degree which will preclude the establishment or maintenance of obnoxious conditions in the stream. Rarely are two problems of this kind found to be alike. The sewage of some cities should be treated to a far greater degree than that of others, dependent on the initial pollution of the stream, its mini- mum volume and velocity of discharge, and the distance to the next city or, more exactly, to the intake of the next water supply. I" 3 CHAPTER IV THE PURIFICATION OF WATER SUPPLIES THE treatment of water to improve its appear- ance and quality has been undertaken in various ways for many years. In ancient times, the most important method seems to have been storage; and from observing the effect of natural filtration through sands, along the shores of streams, it is not improbable that some form of filtration was employed at a very early date. The Chinese, from very ancient times, have used sulphate of alumina for the purpose of improving the appear- ance of water. In modern days, the first large filter appears to have been placed in service on the water supply of London, England, in 1829. After the cholera epidemic of 1849, the filtration of the entire supply of that city was made com- pulsory. But the existence of disease-bearing bacteria, or "germs/' was unknown, and the most important office of filtration was not appreciated until long after this date. 43 > z < :> Onj d -a !D o II < - ac-g u 44 purification of Mater Supplies The life-work of the immortal Pasteur demon- strated the germ theory of disease, and gave a new meaning to water purification, as well as to all branches of sanitary science derived from biology. The work of Koch on the causes of cholera, which created the technique of bacteriological study, and included the discovery of the cholera germ, or bacillus; that of Eberth and Gaffky on typhoid fever, with the discovery of its specific bacillus; and that of the Bacillus coli by Escherich, gave a new purpose to water purification, and sewage treatment. These dis- coveries late in the last century led to the wide- spread adoption of water filtration, with the re- sult that typhoid deaths were reduced by this means in many of the great European cities, to a very small fraction of their former number. This work also led sanitarians to conclude that, with a universal adoption of this means of protection, typhoid, cholera, and other water-borne diseases would in time entirely disappear from the death statistics of nations. Water purification was an English invention. The first filters, as mentioned before, were placed in 1829 and the whole supply of London was ordered filtered in 1849 following which the in- troduction of filters in other cities made rapid progress. In 1860, English engineers installed the first 45 purification of Mater Supplies filters on the Continent at Altona, Germany, later at Berlin, and at several other German cities. The Altona filters are famous as having prevented the cholera epidemic from spreading to that city in 1892, although it raged in Hamburg, an adjoining city which was not served with filtered water. Both of these cities at that time took their water supply from the Elbe River into which also they discharged their sewage, without treatment. Altona filtered its water but Hamburg did not. At present, both cities filter their water supplies but neither of them finds it necessary to go further with sewage treatment than medium fine screen- ing. The Hamburg sewage screen plant has screens with A inch clear openings. Altona uses coarse screens for part of its sewage dis- charge, but for the major part provides no treat- ment whatever, depending entirely on water puri- fication for the safety of its water supply. Out of the English practice two types of filters have been developed for water treatment. These are usually named from their most salient fea- tures, slow sand filters, and rapid sand filters. The earlier installations were all slow sand filters. A slow sand water filter consists of a watertight basin, the floor of which is provided with under- drains, with a covering of about one foot of coarse gravel, over which are placed several feet of clean sand. To prevent freezing, a roof usually carried on groined arches is placed over the basin, 47 Sanitation of Cities The drains referred to, consist of a main col- lector with lateral branches at regular intervals graded stone or coarse gravel is usually placed PARIS, FRANCE A park-like development of the irrigated field from the sewage treatment plant by broad irrigation on the bottom, sufficiently deep to cover the lateral drains. Over this, the sand, which is the filtering material, is placed to a depth of three or four feet. When ready for service, water is permitted to enter the filter to a depth over the sand of about three feet, and percolates through the sand at a daily rate of about ten cubic feet per square foot of bed, affording a daily flow of about 3,000,000 gallons per acre of surface. But it is not until after several weeks of operation that the filter does its best work. By this time, a gelatinous film has formed on the surface of the sand, derived 48 purification of TKHater Supplier from the organic matter and sediment present in the unfiltered water, which gives it its highest effi- ciency. This film, however, becomes in time so thick that it clogs the filter, and the operation must be interrupted for its removal, and for the cleansing and restoration of the surface. There are various ways of effecting this, some of them very ingenious. The result is that the capacity of the bed is renewed and operation again proceeds. Where the untreated, or raw, water carries large contents of suspended matter, settling tanks are used as a preliminary treatment before filtration. Filters of this type with variations have been installed in many cities here and abroad, the ORMOND, FLORIDA View along the shore of the Halifax River plants in England being particularly well known. Those at Altona and Hamburg in Germany have been mentioned. There are many others in that 49 Sanitation of Cities country. In Japan, a number of such filters have been built, those at Yokohama and Osaka being noteworthy. The largest filter plant of this type is at Philadelphia, Pa., and treats water from the Delaware River. Rapid sand filters, as well as slow sand filters, were originally invented in England. A chemical coagulant is always added to the water to be fil- tered by rapid sand filters, and preliminary sedi- mentation is usual. The sand grains are coarser, and the bed of sand is cleaned in place, by revers- ing the direction of flow so that filtered water is forced back through the filter bed. The raw water is first clarified by the addition of the coagu- lants, and after sedimentation in a tank, is passed to the surface of the bed, over which the coagu- lant causes the rapid formation of a gelatinous film, and is allowed to pass downward through this and the sand at a rate about forty times greater than the slow sand filter would permit. Rates of 100,000,000 to 125,000,000 gallons a day to the acre of surface are usual. The filters are usually built of concrete, each consisting of a rather small unit; embedded in the floor of each is the underdrainage system, consisting of perforated pipes or strainer cups, de- signed to allow the filtered water to flow out, but to retain all the sand and effect an even distribu- tion of the wash water, when the direction of flow is reversed for cleaning, by which means the layer 50 5' PARIS, FRANCE View shows the purified stream of sewage which discharges into the river nearby. The water is as clear and sparkling as spring water purification of "Mater Supplies of dirty material is broken up and removed from the upper surface of the sand, and led away through waste gutters to the sewer. Washing takes only from ten to fifteen minutes and, due to the coagulant, a new film forms quickly. The coagulants commonly used are compounds of alumina and iron. Rapid sand filtration has come into extensive application since 1885, when such a plant was installed at Somerville, N.J., attracting much attention. Since then, nearly 400 cities in vari- ous parts of the world have adopted this method of water filtration. The largest plant of this kind is probably that of Cincinnati, Ohio, with a daily capacity of 1 12,- 000,000 gallons. Some of the noted plants are at New Orleans, La.; Hackensack, N. J.; Little Falls, N. J.; St. Louis, Mo.; Louisville, Ky.; Toledo, O.; Minneapolis, Minn.; Grand Rapids, Mich.; Alexandria, Egypt; Kyoto, Japan; etc. Among the cities in America provided with slow sand filters may be mentioned Washington, D.C.; Albany, N. Y.; Poughkeepsie, N. Y.; Philadelphia, Pa.; Superior, Wis.; and other places. The question as to which method, whether the slow filtration or the rapid, is better for any place, depends much on local conditions. Both give good results, and each has its advocates. With either, the water consumer is reasonably insured 53 Sanitation of Cities against water-borne disease, and is certain of an excellent water for all purposes. It should be noted that none of the cities, men- tioned above, undertake to purify their sewage beyond the sanitary requirements, nor beyond what is necessary to maintain a satisfactory oxy- gen content in the rivers and to prevent the formation of sludge banks and visible pollution. The disinfection of water to remove disease germs is frequently resorted to where the water is taken directly from sources of supply without filtration. The chemicals ordinarily used are hypochlo- rites of lime or soda, or liquid chlorine'gas. These If LONG BEACH, CALIFORNIA Bathing beach adjacent to sewage treatment plant chemicals are applied in very minute quantities with entire success. The majority of American cities have at times used them with good results, 54 purification of Mater Supplies under special conditions, and sometimes follow- ing filtration. These chemicals are also used to disinfect treated sewage, when it is necessary to render effluents harmless, in the protection of oyster beds, or to kill disease germs that might find their way into the intake of a water supply plant far- ther down-stream. THE BEACH AT DAYTONA, FLORIDA A popular winter resort having a modern sewage treatment plant 55 > 00 13 CD c/3 33 -'C &JD &JD -i- 1 > o X < CD Z UJ Q CO W tf, Q C bJO ^S c^ t (DO sa u C/3 o S >, O X w 56 CHAPTER V THE SEWERAGE SYSTEM THREE different plans or classes of sewerage sys- tems are in general use. Of late the newly de- signed intercepting sewers which carry the out- fall to a new point of final discharge have come to be called the main drainage. The method of sewage treatment required by a city depends very largely on the design, extent, and class of sewerage systems installed. Each of these sys- tems may be briefly considered, as follows: THE COMBINED SYSTEM In this system all kinds of sewage and drain- age are carried in the same sewers. There is ordi- narily but one sewer in each street, and to this the street inlets or basins are connected to admit the storm waters, as well as the house sewer connec- tions, which admit all domestic wastes, roof water, yard water, etc. In this system the outfall mains are of suffi- cient size to take care of the vast quantity of storm water when it rains; consequently they are 57 ZTbe Sewerage System so large that in dry weather they act as settling tanks, and delay the velocity of the domestic or dry weather flow sewage which causes deposi- tion of solids in the sewer inverts. The solids thus deposited remain, and decompose until a storm flow flushes them out. With this system, the sewage in dry weather loosens much sus- pended matter during its passage through the sewers, and the storm flow is rendered exceed- ingly heavy with decomposing sewage solids which are gathered up from the inverts during the first part of a storm. COMBINED AND INTERCEPTING SYSTEM This system is similar to the foregoing system; in that all of the smaller sewers are combined sewers; but to obviate the trouble caused by the dry weather, or domestic flow, in the large mains, and prevent the deposits therein of sewage solids, intercepting sewers are provided to collect the dry weather sewage from the smaller sewers, and act to some extent as separate sewers, paralleling the lines of the large mains. These interceptors take off the dry weather flow at certain places called diversion points, by gravity, as they are usually placed at a lower elevation. SEPARATE SYSTEM In this, a double system is provided; one sys- tem for the storm water, usually called drainage, 59 4 6o Sewerage System and one for the sewage, usually called sanitary sewers. The cost is much greater than the others, but the system is more efficient and, if possible, should be used rather than either of the others; especially, if the sewage or the storm water, or both, are to be treated; as their treatment in- volves very different problems, and is much more economical if each is kept separate. The installation of the sewerage system, for a given city, has usually been completed to a great extent before the city planner, or replanner, has been consulted. In most of our cities the sewer- age system, like the street system, "just grew" without design and is especially in need of ex- pert study, and complete redesign. The progress that modern cities have made in population, commerce and material prosperity, was not and indeed could not have been foreseen, even a few years ago. In sewer design, the most that was usually attempted was the removal of polluted waters from the houses and streets, and the discharge thereof into the nearest waterway deemed of sufficient size to carry off the dis- charge without causing a local nuisance. Where sewage treatment was adopted, the method was usually but little better than an experimental ap- plication of some laboratory results, that seemed sufficiently promising to justify a more extensive trial. 61 CROSSNESS, LONDON, ENGLAND Chemical precipitation sewage treatment plant CROSSNESS, LONDON, ENGLAND Sewage treatment plant chemical precipitation CHAPTER VI THE SEWAGE TREATMENT PROBLEM DISPOSAL of the wastes of human life has, from the earliest times, been one of the problems of civilization. As early as the ninth century before Christ, the Assyrians constructed a sewer to drain one of the palaces of Nimrod. The Romans, the great engineers of antiquity, devoted much attention to sanitation, in which they made steady progress up to the fall of the empire. The Cloaca Maxima, or Great Sewer, of Rome, constructed about the seventh century be- fore Christ, is still in use. With the advent of the dark ages, sanitary en- gineering went the way of learning in general, and all that the Romans had learned seems to have been forgotten. Great cities grew up in Europe, entirely without provision for the disposal of waste matter, and in time inevitably became lit- erally buried in filth. Great plagues broke out again and again, and swept like devastating fires 63 Sanitation of Cities over mediaeval Europe; cities became vast char- nel houses, and the accumulation of filth almost surpasses human belief yet it was not until the LONDON, ENGLAND Showing boat for conveying sewage sludge to the North Sea whence it is discharged fifteenth century that faint interest began to be manifested in the study of sanitation and not until well into the nineteenth that the subject be- gan to be understood. As late as 1847 John Phillips, one of the first engineers to make an of- ficial report on sanitary conditions in London, stated that conditions as he found them were so bad as to defy description. In 1848, 1849, and from 1852 to 1854, London was devastated by cholera. In 1849, 14,600 deaths were recorded; and in the latter half of 1854, 10,675 deaths. The connection between the rapid spread of the disease, and a contami- 64 66 Sewage treatment problem nated water supply, was readily shown, and the result was an Act of Parliament, which laid the foundation for the prosecution of plans for an adequate sewerage system. It may be said that modern sanitary engineer- ing dates from the construction of the Hamburg sewers by William Lindley in 1842. Since that time, rapid progress has been made and, particu- larly in late years, many millions of dollars have been spent in this country and abroad, in the con- struction of systems of sewerage and sewage treat- ment plants. The serious consideration of sewage purifica- tion in this country may be said to have begun with the construction of the chemical treatment sewage disposal plant at Worcester, Mass., in 1889, and the establishment of the Massachusetts State Experiment Station at Lawrence at about the same time. Although sewage irrigation was practised in ancient Athens, and in the Far East for about 2000 years, and sewage farming was introduced at Bunzlau, Germany, 300 years ago, it was not until 1850 that the purification of sewage began to attract attention in England. During the period between 1850 and 1875, the impetus given to sanitary work by the cholera in London re- sulted in the sewering of many towns, with conse- quent pollution of streams, and it became neces- sary to develop some method of purifying sewage. 67 Sanitation of Cities Sewage may be treated on agricultural land to secure a more or less complete purification, if sufficient land is available for this purpose; or on intermittently dosed sand filters, with the same end in view. Here also the purification secured is biological, and there is a fairly well marked limit beyond which land or filters will not afford purification. This limit can be much enlarged by preliminary treatment. Without preliminary treatment, land used by the method known as broad irrigation, as practised in France for the sewage of Paris, and in Germany for the sewage of Berlin, is capable only of receiving the sewage of from 50 to 200 persons per acre, depending upon the character of the soil. Intermittent sand filters, under similar conditions, will only provide for from 250 to 1000 persons per acre. Broad irrigation and sewage farming soon proved unsatisfactory and sanitary development leaned in the direction of septic tanks and trick- ling filters as more intensive methods. From earliest times household wastes have been carried in one way or another to the nearest water course or river capable of receiving them without causing a nuisance. Primitive as this method is, it is still one of the most practical methods of sewage disposal, and is generally known as "Disposal by Dilution/' This method answers the requirements as long as the proper conditions are maintained that is, 68 Sewage {Treatment problem as long as the volume of water is sufficiently great in proportion to the amount of waste allowed to pass into it. But with the rapid growth of cities, the pollution of waterways and harbors becomes a serious problem, and the development of meth- ods of sewage treatment has been mainly with the object of preparing sewage for dilution, so that the streams receiving the effluent can safely take care of the burden of self-purification. If the sewage is discharged into a sufficiently great volume of water, say 3% to 4 cubic feet per second of flow per 1000 persons contributing sewage, as provided for by the Chicago Drainage Canal, no treatment is considered necessary, as the water will in time effect complete purification by biological agencies, in the presence of the dis- solved oxygen content of the stream. But even in this case, sanitary standards require the re- moval of floating and suspended matter from the sewage. Where the volume of flow per second in the waterway falls below the above requirements per capita, some other form of sewage treatment is usually resorted to, and the extent of treat- ment required will differ in each case with the volume of water available for dilution of the effluent, with the local conditions, as well as with other factors which enter into the problem. Obviously where streams or other waterways will not afford sufficient dilution to effect biolog- ical purification, without causing exhaustion of 69 yo Sewage treatment problem dissolved oxygen from the water, or where the formation of banks of deposited sewage solids might cause a nuisance, even if the water for dilu- tion were sufficient, preliminary or preparatory sewage treatment is necessary. Also, where the disposal is on land, or by means of sand filters, in order that the polluting effect of the sewage may be so far diminished that a much greater quantity can be disposed of per acre by these methods, pre- paratory treatment is required for the same reason. CHAPTER VII THE BIOLOGICAL TREATMENT OF SEWAGE SEWAGE treatment is seldom undertaken at a sewage disposal plant, regardless of the method employed, with the object of producing actual sewage purification. This would indeed be a very costly matter, and fortunately is required only under exceptional conditions, and is practically restricted to the method known as sand filtration. Purification is, however, the end or result which every method has in view. As this may seem a paradoxical statement unless further explained, it should be pointed out that the purification of polluted waters observed in nature is strictly a biological process; and that considerable time is required for its complete action, whether by fil- ters, on land, or by dilution. The object sought by sewage treatment is the removal to a greater or lesser extent, as condi- tions require, of the floating matters, settling mat- ters, non-settling putrescible matters, and ob- jectionable bacteria. Trade wastes, which are 73 o z C3 O Y DIVISION I JAMAICA BxrOwuioN ItammflmM NEW YORK CITY, N. Y. Chart showing proposed number and location of district or divi- sional sewage treatment plants (indicated by black symbols) suggested by the Metropolitan Sewerage Commission 81 CHAPTER VIII DIFFICULT PROBLEMS FOUND IN TREATING SEWAGE ONE of the greatest difficulties connected with sewage treatment is the disposal of sludge from septic tanks and settling tanks, as the sludge from these tanks is highly putrescible. This has led to the invention of two forms of tanks, each of which attempts to carry the septic treatment of the sludge to such a point that when discharged it will not cause a nuisance. These tanks depend upon the assumption that when the so-called septic action has been carried to its extreme, the unstable organic matters which are attacked by anaerobic bacteria, become in- capable of further putrescence and dissolve, or split up; part going into solution, part into inert matters, and part remaining as organics, that do not readily putrefy, which are deposited with the mineral materials present on the bottom of the tank. The greatest problem met by designers of tanks has been to design a tank in which the reten- 83 < .y i Q g 00 rt 8 4 ^Difficult problems ifounb in treating Sewage tion of these putrefying matters would not cause them to mix with the incoming sewage, and render it highly "septic/' or putrescent, as it left the tank. This was the great difficulty with the original septic tank. The first two-stage, or two-story, tank was in- vented in England about fifteen years ago and was known as the Travis tank. It is provided with two upper, or flowing-through chambers, the bottoms of which are inclined at an angle of about 45 degrees and are provided at the lowest point with ports, or openings, into the lower chamber which was placed between the two upper cham- bers, through which the settlings and sludge pass by gravity. The lower, or digesting, chamber has its bottom, which is the deepest part of the tank, formed in one or more hoppers, or inverted pyra- mids, provided with sludge outlet pipes. The upper part of this chamber is at the same eleva- tion as the upper part of the flowing-through chambers, and a portion of the sewage is per- mitted to pass through it. The flowing-through chambers have a network of slats formed into trellises which are placed across the direction of the flow, the purpose of which is to act as a remover of colloids by "adsorption/' it being claimed that fine particles of organic matter in a colloidal state tend to adhere to surfaces where they are readily attacked and liquefied by bac- teria. 85 Sanitation of Cities But few plants with tanks of this type have been built. The effluent was little if any better than from a septic tank. The sludge was not suf- ESSEN, GERMANY Imhoff tank sewage treatment plant ficiently digested to dry on a bed without causing odors. At Norwich, England, using this system it was necessary to dispose of the sludge in trenches. The Imhoff tank is a more successful effort to solve this very difficult problem. Invented at Essen in Germany, it is a further development of the Travis principle. It discards the "col- loiders," and provides two chambers, an upper or flowing-through chamber for the sewage, in- tended for plain sedimentation, and a lower or digestion chamber, for the settling matter or sludge. The upper chamber is designed with sharply sloping bottom surfaces, provided with 86 Difficult problems tfounb in treating Sewage slots at the lowest point, through which the set- tlings enter the lower, or digesting chamber: a baffle or fender is arranged under the slots to pre- BALTIMORE, MARYLAND Imhoff tank sewage treatment plant vent the gases arising from the digesting matters from entering the upper chamber. The lower chamber is provided with vents or chimneys which reach the surface to permit the escape of gases into the air. Many tanks of this form have been built, especially in Germany, and when properly de- signed and operated with a very short detention period this has proved to be the best type of tank. The septic process is essentially a fermentation and rotting out process. It is an attempt to let nature take her course, in carrying out the various changes that are required, for the partial or com- 87 Sanitation of Cities plete decay of organic solids; but confining the nuisance, and odorous process, within the limit of a tank. It now is well understood that this process requires a long time to accomplish much of value in the reduction of organic solids; and that the danger of a nuisance is present, in the tanks so far designed. LONG BEACH, CALIFORNIA R-W screen sewage treatment plant adjacent to bathing beach shown in small insert 88 CHAPTER IX THE MECHANICAL TREATMENT OF SEWAGE THE natural agencies employed under operating conditions sometimes escape from the control under which the septic type of plant attempts to place them, and cause odors and a more or less active nuisance. Since the first tank was used, objections have been made on the part of the public, and sanitary engineers have sought for other methods of freeing sewage from matters in suspension. It was noted soon after tanks began to be used that they did not give a very high removal of total solids from the sewage, and that much suspended matter passed from suspension into solution, making the liquid part more foul than before, especially if subjected to long periods of detention. An obvious principle of sewage treatment is, that the quicker the polluting organic solid mat- ters are removed from the liquid part the better, as this prevents solution of the solids; it also 89 Gbe flDecbanical treatment of Sewage keeps the sewage from becoming septic, and pre- vents the vast increase of bacteria that a long period of treatment invites. As sedimentation was at best a slow pro- cess, and could seldom escape causing septic conditions, it was asked, "Can we not find a mechanical method of treatment which will re- move the suspended solids at once?" On this problem engineers and scientists have been en- gaged many years. Much of this work was done in Germany where, as in America, with large rivers, conditions were favorable to the discharge of fresh liquid sewage if freed from suspended matters above a certain size, without further treatment. In England the streams as a rule are so very small that the mere removal of fresh suspended solids was not usually sufficient, and filtration was required in any case; and having started by using tanks before filtration, the con- servative English engineer has been slow to take advantage of progress made elsewhere. Much has been published about the success of the mechanical treatment of sewage in Germany. For the present purpose it need only be stated that the quick removal effected by fine screens of the suspended matters above a certain predetermined size to be decided upon to meet the local needs has been very successful. The evidence of this success has appealed so strongly to American engineers familiar with Ger- 91 flDecbanical treatment of Sewage man fine screen plants that the introduction of fine screens for treating sewage in the United States has made rapid progress, and is giving gen- eral satisfaction. There are a great many such plants abroad, some of notable interest; of which Dresden may be mentioned as a type and as the largest instal- lation, where the sewage of an entire city, having a population of about 600,000, is fine screened as its only preparation for discharge into the Elbe River, a small stream at this place, and more than 400 miles from the sea. A principle followed in the design of sewage treatment plants in Germany has been, first, to improve the river that is to receive the effluent, so as to improve its capacity to afford dilution, and at the same time render it better able to carry river transportation. Thus a commercial water- way of great economic value can be created, with part of the funds, and the cost of sewage treat- ment greatly reduced. To prevent nuisance in the unimproved stream would have required a much higher grade of treatment, and greater in- vestment of money in plant, as well as more costly operation. Having regulated and dredged the river, it has usually been found that the needed expenditure for sewage treatment has been reduced more than half, and a prosperity producing improvement obtained, for money that would otherwise have 93 94 flDecbanical treatment of Sewage been locked up in a costly sewage treatment plant. It may confidently be stated that in America with its large rivers, more than half of the money used in sewage disposal plants, and expensive main drainage systems, would far better have been expended on the improvement of the rivers; with the two objects in view of making them valuable commercial assets, and of reducing the need of sewage treatment expense to a minimum. Dredging commercial waterways and deep chan- nels, not only provides for water-borne freight, but also greatly increases the quantity of water present available for sewage dilution, and pro- vides favorable conditions for the mechanical treatment of sewage. The danger from floods is also greatly reduced, and the natural drainage of extensive tracts of country much improved; swamps and marsh lands are dried, directly pre- venting malarious conditions, and destroying the breeding places of mosquitos. The commercial and sanitary conditions are all benefited by such use of money and the saving in cost of sewage treatment is large. Money used in waterway im- provements gives immense returns on the invest- ment, while that used on sewage treatment plants notwithstanding their sanitary importance is locked up forever. 95 DRESDEN, SAXONY Interior view of the screen house, showing general arrangement of the Riensch-Wurl screens (each twenty-six feet three inches diameter), screen bridges, motors and driving mechanism, with elevators for screenings, effluent discharge channel at left CHAPTER X THE PURIFICATION OF SEWAGE FROM the foregoing considerations we now turn to the need of a more complete treatment of sew- age than the removal of suspended matter will give. Such treatment may be required if the efflu- BALTIMORE, MARYLAND Trickling filter bed, the largest plant of this type in the United States ent is to be discharged into a stream so small that the diluting water will not provide biological puri- fication without putrescence. The means of giv- 97 p OJ Jo > 3 I z "L LJU ^ CD M- 9 8 purification of Sewage ing this higher grade of purity to the sewage is strictly biological, and the designs used in such plants have for their object the cultivation of BALTIMORE, MARYLAND Sewage treatment plant, showing two cylindrical screens for treating the sewage after passing through tanks prior to entering filter beds aerobic bacteria under control, and in the presence of a plentiful supply of oxygen. The standard methods now used are all sec- ondary forms of treatment; that is, the sewage has already passed through a stage of preparation by which suspended solids have been removed to a greater or lesser extent. Examples are shown in the accompanying illustrations of the various forms of plants used for the purpose. It would be useless to attempt a detailed com- parison of the methods of secondary or oxidation treatment. The installation of such plants is sel- dom really necessary, and much public money has been uselessly expended in the futile attempt to 99 IOO purification of Sewage make drinking water out of sewage. The real and usually the only requirement is to prevent a nuisance in a stream or waterway the use of which is unavoidable for sewage discharge. In Chicago a few years ago, a board of consult- ing engineers considered various plans for the sewage disposal of that city. One of these plans consisted of primary and secondary treatment by means of tanks, followed by sprinkling filters of tf immense size and capacity; the other was for a E canal connecting the waters of Lake Michigan^ u with the Illinois River, thereby creating a great 5 commercial waterway, into which the entire sew-^ w age of the city could be discharged, and com-5 =J j pletely treated by the mere dilution thereof, withj o o the waters of the canal. to h E z U U > 2 1 111 O CITY OF CHRISTIANIA, NORWAY View of waterfront and Riensch-Wurl treatment plant (indicated by arrow). Note class of residential buildings in immediate vicinity of the plant and pleasure craft in the harbor into which the screened effluent is directly discharged The result to be obtained by the first method at best was uncertain, and the period of time dur- ing which it would be sufficient was doubtful. 101 102 purification of Sewage The success of such a plant depended principally on perfect care and first-class ability being ap- plied to its operation and maintenance. At best, VIEW OF CITY OF CHRISTIANIA, NORWAY Showing location of screening plant, indicated by arrow the very large cost would give nothing of com- mercial value. Its condition would rapidly de- preciate in service, and in a few years call for ex- tensive repairs, and finally for reconstruction. It would require many acres of valuable land which besides first cost, would be removed permanently from industrial or home development; and large surrounding areas would probably be rendered undesirable by the presence of the plant, which would cause local nuisance and depreciate prop- erty values. The canal avoided these objections. The water available for dilution afforded a satisfactory treatment, and insured the inoffensive oxidation of sewage pollution within a few miles of the en- trance of the sewage. No valuable land was to be taken from its natural development and tax- able value; and taxable values would be in- 103 Gbe Sanitation of Cities creased, instead of diminished, by the presence of the canal, as its commercial possibilities be- came evident. The commission wisely decided upon the canal, which is now completed, and gives Chicago a com- manding commercial situation, since through it can come to its gates the commerce of the Missis- sippi and its tributaries which, when fully devel- oped as they are almost certain to be, will lead a flood of gold into her commercial channels. 104 CHAPTER XI DEVELOPMENT OF COMMERCIAL WATERWAYS AS A SANITARY MEASURE THE development of the internal commerce of the United States is one of the most important interests of our nation. With the great increase in cost of railroad operation, resulting from a diminishing coal supply and lack of labor, the return of river and canal transportation for freight is to be expected. Our country is far be- hind the old world in this respect; there, a large portion of freight, especially in heavy bulk, is carried by steamboats and barges, and the regu- lation of rivers and waterways and canal devel- opments have been brought to a high point of efficiency. We are just about making a start in this line, and the prosperity of many cities is deeply concerned in the progress of this means of transportation. Cities served by railroads only may within a few years find themselves outclassed by more fortunate rivals possessing river and canal facilities. 105 io6 Waterways as a Sanitary Measure The Great Lakes form a chain of inland seas which are paralleled by many of the great rivers at approachable distances for connection by canals. The development and regulation of these rivers, with canals passing from them to the lakes, will afford the most splendid internal commercial waterways in the world, and one of the greatest projects ever proposed by the civil engineering profession. Of such canals, the New York Barge Canal is the most important that has been realized in completed form. That it is to be only the first among others as important is confidently antici- pated. Now that New York has opened this im- mense opportunity for reducing the cost of traf- fic, others will soon follow. The sanitation of cities situated on rivers that can be improved to afford much larger volumes of water than at present, and on canals compar- able in size to the Chicago drainage canal can, by developing their waterways and making exist- ing channels deeper and wider, save much of the cost required for sewage treatment plants. The money saved by thus avoiding the necessity for constructing vast sprinkling filter beds, etc., can be applied to improvements of a more desirable and profitable kind. The New York State Barge Canal, beginning at Buffalo, will carry an ever increasing stream of commerce to New York and Brooklyn, and this 107 . CD ; Z S * O "^ x *o ^ o ^ &^>^ - ^ b c ~7 v- TO .11 Si"* w S >, CL> I 08 Waterway as a Sanitary flDeasure will have an important effect on many local sani- tary problems. Jamaica Bay, a large but shal- low body of water within the area of the city of New York, and adjoining the harbor, was be- coming polluted with sewage, and was negligible in commercial value because of the high cost of dredging, until the prospect of the traffic to be anticipated from the new barge canal made its value apparent, and plans were prepared for its extensive improvement. It was then found that with the newly dredged channels, required for commerce, the sanitary problem had been much simplified; that biological sewage treatment plants consisting of sprinkling filters for the treatment of sewage entering the new channels, would not be necessary; and that money thus saved might be used on other improvements. There are doubtless many other places where dredging adequate channels in a stream or harbor for the benefit of commerce would also solve the problem of sewage treatment to such an extent that the cost of treatment plants would be reduced more than half, and risks of nuisance entirely disappear. Such problems invite the serious study of municipal officials before they authorize the expenditure of large sums of money on disposal plants that would become needless, should the river or harbor be properly dredged for shipping. 109 z OX) ( u 2 O II > cx UJ I 10 CHAPTER XII HIGH PRESSURE FIRE SERVICE THE health and prosperity of the community depend upon pure water,, sanitary conditions, successful industry, and facilities for ready trans- portation of freight and persons. The public does not fully or properly comprehend the ben- efits to be derived from a general and thorough study of municipal problems in the supply of pure water and the treatment and disposal of sewage, rubbish, and garbage, as parts of a com- mon municipal development. The reasonable procedure to follow would be to have trade wastes treated prior to discharge into the municipal sewers, so that such wastes would be at least in a condition comparable with the domestic sewage of the city. Moreover, the value of by-products to be derived from this treatment of trade wastes should be of special interest to the manufacturer. The problems of city sanitation include and merge into the more general problems of the pub- lic welfare. The agencies of municipal govern- ii i z J ^ O c Cd o CQ '-5 O . O u. co K > S t S u 2 I 12 Ibicjb pressure ]fire Service ment are all provided for that one end and purpose city sanitation and municipal welfare go hand in hand. The administration with its executive, police, health, street-cleaning, engi- neering, and fire protection departments, etc., all should be considered in connection with the pub- lic welfare and city sanitation. It is not possible in such a brief survey as this study intends to go further into detail as to the influence of all these and other municipal departments on the sanita- tion of cities; but the effect of each is obvious a full accounting of the progress made in the de- velopment of all of the various agencies of city welfare would be most interesting. For illustra- tion on this point we may take the single feature of fire protection a most important and inter- esting subject in itself affording a rather strik- ing picture of municipal progress. Not many years ago our fathers were satisfied with bucket brigade fire protection, and each solid citizen of the last century had his half-dozen leathern buck- ets, marked with his initials and the words 'Tor fire only/' hanging in his hall at a convenient place, ready for the emergency when the fire bell should call out all of the volunteer fire laddies. Next came the well-known fire engine, still with us; and in the fullness of time came the high pres- sure service, with its powerful pumps, typifying modern progress. The practice of protecting the congested busi- "3 1bigb pressure fire Service ness districts of our greater cities by means of high pressure fire service is now so well established that we can scarcely realize the feelings of busi- ness men in the past, before the adoption of this system, who, on leaving their offices and ware- houses at night, were always haunted by the dan- ger of destructive conflagration before morning. The experiences of Chicago, Boston, and Balti- more are still fresh in the public memory; but with the new high pressure protection the danger has largely vanished. A few pictures of some of these stations are included as an indispensable feature of this study. Greater New York was the first city to install such a fire protection service. The first high pressure stations were constructed in the Borough of Brooklyn, followed soon by stations in the Boroughs of Manhattan and of Richmond. Not only cities of the first class, such as New York, Philadelphia, San Francisco, etc., have in- stalled high pressure fire service, but many smaller and no less progressive cities such as Miami, Florida, for instance have also estab- lished this protective method of fire protection; and almost every American city not yet so pro- tected now has the project under advisement, and it is generally admitted by all authorities that no subject can be of more urgent importance. 115 n6 CHAPTER XIII CONCLUDING REMARKS CONSIDERING the vastness of the subject, we have presented a very brief review of the Sani- tation of Cities. With our rapidly increasing population, and the almost magical growth of cities; with problems of housing, providing markets, means of industry, and of recreation, etc., into all of which sanitary questions enter, the immensity of the sanitation of cities prob- lems is apparent. Of necessity, we have been forced to limit the various questions discussed to broad principles. A thought that we wish to convey in con- clusion is the unity of municipal problems, and particularly the problems relating to Sanitation. It may be said that these problems are really one, which might be generalized as the "Human Problem." Wastes of all kinds are the result of human life; whether derived from the home or the factory, they must be disposed of. Pure water must be obtained and supplied in an unfailing 117 18 Conclubing IRemarfcs stream, regardless of cost, but funds must be ex- pended with a wise economy. To these matters we have given our principal attention in this study. It is evident that we have been discussing but one problem of many parts, and that it is of such extent that even if presented in many more pages than we have used, the subject would be far from exhausted. The most we can hope for is that in a brief space we have given the reader a picture of some of the larger problems involved, at least, with well defined outlines of the Sanitation of Cities. 119 Designed and Illustrated by FRANKLIN V. SIKES, Inc., Neu; York Printed by THE DE VINNE PRESS, Neu; York THIS BOOK IS DUE ON THE LAST DATE STAMPED BELOW AN INITIAL FINE OF 25 CENTS WILL BE ASSESSED FOR FAILURE TO RETURN THIS BOOK ON THE DATE DUE. THE PENALTY WILL INCREASE TO SO CENTS ON THE FOURTH DAY AND TO $1.OO ON THE SEVENTH DAY OVERDUE. JAN 26 1937 JAN 27 1937 fcj 1347 MAR 26 1949 APR 9 1949 LD 21-a 788192 Engineering Library UNIVERSITY OF CALIFORNIA LIBRARY