Conservation by sanitation; air and water supply; disposal of waste (including a laboratory guide for sanitary engineers)

Front matter

Copyright ]^^.

COPYRIGHT DEPOSIT

WORKS OF ELLEN H. RICHARDS

Foreword

THE SPIRIT IN WHICH THE PROBLEMS OF MODERN CIVILIZA- TION, ESPECIALLY THOSE IN RELATION TO AIR SUPPLY AND VENTILATION AND WATER SUPPLY AND WASTE DISPOSAL, ARE TO BE APPROACHED AND SOLVED

The sanitary engineer has a treble duty for the next few years of civic awakening. Having the knowledge, he must be a leader in developing works and plants for state and municipal improvement, at the same time he is an expert in their employ. But he must be more; as a health officer he must be a teacher of the people to show them why all these things are to be. The slowness with which practicable betterments have been adopted among the rank and file is, partly at least, due to the separation of functions, of specialization, and partly to the exclusiveness of agents in the work.

The individualism of the nineteenth century extended to the domain of hygiene. The physician looked after the interest of his patient, not of his patient's neighbors, and the mass of the people went their own individual way without giving him a chance until the mischief was done. The advocates of Preventive Medicine, among whom were some of the most eminent physicians, found stony fields for the seed they wished to sow. The engineer had to plow this field, lift out the stones, and prepare the ground. The application of sanitary principles used for the benefit of the people with the same energy and business sense as has been used for the profit of the individual, will soon prove that sanitation will pay as well as railroads and machine shops.

Sanitation cannot be fully developed until capital employs the expert in both engineering and sanitation to plan for the masses vi FOREWORD

of people who have not the means either financial or practical to live under such conditions as make for their own happiness and the State's wealth. Hence the new era we are entering upon demands a new training, a fresh point of view. It may be that fortunes will not come so readily to the engineer as they have come to the business promoter, but there will be honorable and well-paid employment. It is open to the sanitary engineering expert to do a service never before acceptable. Therefore this side of the professional training should be kept in mind. Knowledge vital to the health of the people should be made as accessible as possible at as little expense and trouble to them as may be.

Here the paths of medical tradition and modern sanitation diverge. In spite of the early recognition of Preventive Medicine and State responsibility, that branch has not until now flourished in medical education. It is a question how far tradition hampers it in its future progress, but no tradition or precedent hampers sanitary engineering. As its name implies, it is all the wealth of engineering knowledge applied to sanitary measures. There must be added the idea of making available this knowledge as quickly and completely as possible, even if some of the application is premature. It is better to believe that all dirt is dangerous rather than to hold it of no consequence how thick the dirt lies. The engineer always uses a factor of safety.

It was better to disinfect needlessly than to suffer longer the unchecked spread of disease. So much of the past work done under the impulse of half knowledge or even under misapprehension of causes has been of value educationally that it cannot be regretted.

It should not be counted against the sanitarian that he cried fire when there was only smoke and sometimes even only dust with no danger of fire. It caused a looking after danger spots, and was much better than the old medical practice, which usually locked the stable door too late.

Let the education of the people go on through mistakes,

FOREWORD Vii

through excess of zeal, if it must, but go on all the time it must. As experience accumulates, wiser means will be found. Let the sanitary engineer seize his opportunity to lead in the apphcation of all knowledge to the betterment of living conditions. Let him not forget the need of teaching the people the value of his services to the commimity as a teacher as well as an expert.

Preface

The experience of twenty years since the first class of sanitary engineers was graduated in 1890 has led to the compilation of these pages from the notes prepared annually for each succeeding class. The work of arousing the intelligent humanitarian is done. The economist and the sociologist are to be confirmed in their awakening interest, but too popular movements are to be deprecated in the beginning of any science.

Sanitation has broadened to a substantial base and there is room for a treatment of the subject from several sides. This volume is primarily a laboratory guide, with resume's of the principles given in the lecture course which accompanies the laboratory, made at the same time readable, it is hoped, to the engineer and health officer who may not have had as full laboratory training. It is not a complete guide for the untrained practitioner; it assumes familiarity with both the bacteriological and the chemical laboratory and access to an engineering library. It is stimulating rather than complete. As one of the youngest divisions of engineering, the subject is barely fledged, not fullfledged by any means. The school course has been loaded with details not agreeing with the bewildering surroundings of the actual plant. The student recently graduated is apt to become confused in his work or abnormally confident in his newly acquired information.

If the engineer can leave school with enthusiasm for his work, with a vocabulary and list of references of recent date he will make his way. If he has a sense of background behind him, a knowledge that these subjects have a past history and will have a future even after he has done with them, he will be in a temper to do good work for his time, not too confident on the one hand and not too pessimistic on the other to be of use. It is this attitude of moderated enthusiasm that we hope to foster.

X PREFACE

The thanks of the author are due to the classes who have been the subjects of experimental notes; to Miss Mabel Babcock for her spirited interpretation of a sketch of American unsanitary habits; to Miss LilHan Jameson for careful proof reading; and especially to Mr. Royce W. Gilbert, who has criticized step by step with great judgment and insight, and without whose aid the volume could not have been prepared.

Part I ^ Chapter Page

I. — Air a Neglected Resource i

Comfort, Duty, Profit. Modern Needs due to Tighter Houses and Better Food.

II. — Standards of Air Supply 6

Domestic and Public, Factories, Trades.

III. — Wholesome Air, axd the Sanitary Inspector ii

IV. — Water Sltplies 19

A. Development from Ancient Times.

B. The Modern Water Works.

C. The Indicated Future.

V. — The Development of the Sanitary Idea as Indicated by the

Municipalization of Water Works 46

Wholesome Water the People's Right.

VI. — Economic and Sanitary Efficiency of Water Works 60

A. Standards of Purity.

B. The Water Assay, the Engineers' Laboratory.

VII. — Protection of Water Supplies as a Conservation of Natural

Resources 85

Implies (i) Clean Soil and Prevention of Fouling.

(2) Husbanding of Rainfall by Storage.

Watersheds and Prospecting for Additional Supplies. The Inspector's and Prospector's Outfit or the Field Kit.

VIII. — The Regeneration (Renovation) of a Spoiled Watershed .. in Effect of Storage.

Office of Oxygen Dissolved and of Green Plants. Color, Odors, and Tastes in Water.

Xll TABLE OF CONTENTS

CHAPTER PAGE

IX. — The Interdependence of Town and Country 137

Rural Sanitation as Affecting the Health of the City as well as of the Country.

X. — Filtration, when Resorted to, how Efficient 151

Sterilization, when Indicated.

Underground or Natural Filtered Waters.

XI. — The Ultimate Disposal of Wastes Liable to Contaminate

Cremation (Garbage C, Animal C).

Dilution (by Soil, by Good Water).

Utilization (Land Absorption of Water and Nitrogen).

XII. — Treatment of Various Wastes 203

A. Dilution may be Sufi&cient for ^Esthetic Reasons.

B. Chemical Treatment may be Needed for Sanitary Reasons.

C. Biologic Treatment and Sand Filtration for Direct Potability.

XIII. — The Community and the Individual 216

The Education and the Position of the Sanitary Engineer in the Progress of Modern Sanitation.

PART II One Laboratory Exercise on the Inspection of Ventilation 225

Twelve Laboratory Exercises on the Examination of Water and

Wastes 231

Chapter I Air: A Neglected Resource

Comfort, Duty, Profit. Modern Needs Due to Tighter Houses, More Food and Closer Living

Man has learned very slowly the condition of his own safe living. Of the three essentials, air, food, water, the air he breathes and is surrounded by, being invisible, is the least known of all.

Before the time of Galen, B.C. 200, air was supposed to be carried in the body by the arteries. It was about 1553 before Servetus in his search for the connection between the breath of life and the soul discovered the circulation of air through the lungs and that the bright color of arterial blood was taken on there. He was burned at the stake for his unholy work.

In 1668 the real ofhce of air was discovered by Mayow but was lost sight of for many years.

Respiratory exchange and its physical and physiological relation is of only recent scientific proof, and even now cannot be fully explained.

It is not to be wondered at that to most persons the word air means very little. They are so used to taking air like other cosmical phenomena, "as it comes,'' that they are not conscious of the effect of different qualities of air upon their brains and bodies. It is only when they themselves are smitten with the more spectacular forms of disease caused by bad air, such as tuberculosis, and when a physician in whom they have confidence assures them that their only chance for hfe is to Hve out of doors, that they begin to reahze that the indoor air they have been taking must have been bad.

To account for the effects of outdoor air, one theory after another has been propounded — such as ozone, aromatic essence from certain trees, dryness, dampness, rarity, density, freedom from earth exhalations, etc. It is one of the great advances of modern science to have discovered that just simple ordinary outdoor air is a most valuable health resource; that a balcony on a city street is a thousand times better than a room in a house closed for fear of drafts, curtained for fear of fading the furniture, and lighted by a lamp.

The long delay in discovering that it was the mosquito and not the night air that brought malaria, caused the habit of closed windows in the country; the fear of burglars was added in the towns; and the cities grew up with the habits of the country; added to the small and smaller living spaces, until thousands of men, women, and children smothered in the products of their own breathing.

It is not too much to claim that only the application of the laws of physics and mechanics have proved the various early medical empirical theories insufhcient.

It is free air, air in motion, that is needed. Motion is an essential factor in life. The still animal is dead matter. Living water is flowing water. Fresh air is air in motion; if the sun shines on it, so much the better. Confined air has an effect like wrapping up in cotton wool. On the other hand, moving air carries away with it the elements of discomfort — heat, moisture, CO2, odors; and, if from the right quarter, brings to us ozone, oxygen, freshness, dryness, and general stimulation.

The engineer and the architect have been expected to provide all these advantages without cost because ''air is free"; they have only to draw their plans as they should be drawn, provide ducts, etc. Result: failure in a large number of cases.

The time has arrived when the engineer and the architect must work together to uphold their professions.

AIR: A NEGLECTED RESOURCE 3

The pioneer held food, which was only to be had by the sweat f his brow, the most costly of his needs. Water required a little effort, either daily to bring it from the stream or spring, or once for all to pipe it to the house and barn, or to dig a well to serve his own and his grandchildren's needs. Air was free — in winter it was an enemy, even, to be kept out of the dwelling. Mankind's primitive habits linger long in the unconscious cerebration of the race.

A distinguished engineer wrote only a few years since: "Food is costly, air is free. If man had to work ... for air as he does for food, he would value it."

Under the latest conditions of crowded modern living, taking account of space, fuel, etc., it is estimated that to supply a family with fresh air costs the householder about one-fourth as much as food, only he does not find it set down in his bill for rent (air space) or for fuel (air moving power, circulation). Air does not circulate in pipes in rooms as does water, but through the whole space; is not an item for which he pays when paying his car fare, or when he buys his theater tickets. Baseball grounds have no roofs and the air circulates freely; this, perhaps, gives that game considerable advantage over the theater.

The cost of the present-day schoolhouse is enhanced 10 to 15 per cent by the cost of the air supply, screened, washed, and circulated; cooled or heated, as the season demands. The city taxes contain hidden under other names charges for clean air, oil or water for streets — cleaners, smoke consumers, special ordinances on nuisances, etc.

Clean ''fresh" air at a comfortable temperature is not free to a single city taxpayer. It is hardly attainable at any price to the lodger, the tenement dweller, the factory worker.

The best that the law can do is to see that the confined air is not vitiated to an immediately dangerous extent.

Contaminated air, affecting as it does the body processes, metabolism, acts as a slow poison first by reducing the body's resistance and thus allowing its various enemies to secure a foothold. It is generally understood to-day by investigators that no one or several substances found in '' bad air " act as an external poison, but that the danger lies in the interference with the normal body metabolism. Thus no one would think of calling heat a poison, and yet it affects the mechanism which regulates body temperature, the most important constant of Hv^ing tissue. Humidity acts indirectly in preventing that loss of heat which regulates body temperature. It has been estimated that 22.9 per cent of the loss of body heat is by water evaporated. This loss is increased by exercise twice or even three times, — from 935 grams H2O in twenty-four hours to 2848 grams when working.

Man cannot control the temperature of outside air, the amount of water it contains, or its pressure; to some extent the amount of impurity it contains may be controlled. Oiled streets and dustless pavements may be insisted on. The city should carry out its duty towards its citizens in the matter of clean air by keeping its streets free from dust and dirt — such as the grit from abrasions of the surface, ground-up droppings, iron dust from wheels and carts, bacteria from dried sputum, etc. — which would otherwise be lifted by the wind.

For example, the State might be visualized as immersed in a great sea. Here and there a city is sending up great clouds of dust, smoke, and foreign gases which may be likened to city sewage rising from points at the bottom of the clear sea. Between these great sources of pollution run connecting roads, boulevards, railways, each sending out all along its sinuous course dense currents of waste and contaminated air. Along these lines of pollution appear houses and factories, often emitting foul air themselves and completely surrounded by dense clouds of air sewage, only appearing to the view as sudden gusts blow the mass away. This sort of visualization will lead to the conclusion that even outside air is bad in the vicinity of cities. It is, but it is better for the most part than indoor air. A man living all his life in the open is said to be able to smell the bad air of a city the moment he steps inside its gates.

AIR: A NEGLECTED RESOURCE 5

We who live and smother in our own and our neighbors' exhalations grow accustomed to the stench.

Out of doors in the daytime is not, however, for the workers of the world. Only the so-called leisure classes and workers in certain occupations, as agriculture, can enjoy that privilege. The work of the world is carried on indoors. Most people, whatsoever their occupation, can, however, with little trouble manage to approximately sleep out of doors. Almost any room having windows on two sides can be kept full of outside air at most seasons of the year. Just as windows wide open from top to bottom will convert an ordinary schoolroom into a model out-of-door school for the anaemic children of our big cities, so wide-open windows may, if properly arranged, convert an ordinary bedchamber into an out-of-door camp for the tuberculous.

The difference between indoor and outdoor air is in small additions, chiefly odors and heat, and in stagnation or "closeness " so that the layer of air next the skin is not changed rapidly enough for comfort. Overheating is the most common difference, and this makes the presence of products of respiration harmful. The Eskimo in his snow hut has the best absorbent in the melting ice.

General discussion for improving the air in enclosed spaces:

(i) Comfort: people will pay for it quicker, perhaps, than for sanitation. Example — theaters.

(2) Duty of cities, to supply better air in the schoolhouses because of effect on future citizens in the development of the race.

(3) Profit: solid cash for owners of factories, etc., in increased capacities of workers. No humanitarian dream of duty, but a business proposition of increased income.

This education of the people to the necessary cost in money (neither time nor strength can supply the want in case of air and water) of sanitary living is one of the duties, as well as privileges, of the sanitary engineer in his sociological relations and is the reason for this brief discussion in this place.

Chapter II Standards Of Air Supply

Curve of Comfort

Air in motion is necessary. When man put a fiat roof over his head and windows in the lower part of his room he began his downward career in health. Warm air rises into a cooler medium, and common sources of bad air give also warm air. Man's breath yields carbon dioxide, heat, and moisture; man's body adds heat, moisture, and odors. Lighting and heating, cooking, sweeping, dusting, even walking on the floor, especially if carpeted, each adds its quota. The resulting gaseous mixture would readily escape if an opening was left, but as it cools by contact with cold walls it sinks to envelop the occupants, deaden their senses, and force back into the body the refuse which freely moving air would carry away. Such at least is the engineer's working theory of house ventilation to-day.

Satisfactory ventilation is the result of the action of several variables, chief of which are humidity, temperature, and carbon dioxide. Dust, escaping gas, other products of combustion than CO2, disagreeable odors from persons, clothing, etc., unsealed sewer traps, — all become more or less important factors at times. Many of these factors may be eliminated by cleanliness, and the engineer should insist that this extra demand upon the apparatus should be removed.

Removal of carpets and upholstered furniture from public halls, or at least their cleansing by vacuum air-sweeping apparatus; floors and walls nonabsorbent and easily cleaned; air ducts smooth and freed from dust by sweeping; electric Hghting; absolutely tight joints in sewer and gas pipes, if insisted upon, would render the hfe of the ventilating expert more tolerable. The noxiousness of confined air is caused not only by accumulated CO2 but also by heat, by excessive humidity, by unpleas-

STANDARDS OF AIR SUPPLY 7

ant odors, especially from the sebaceous, sudoriferous, and intestinal secretions.

In the absence of a better indicator, lo parts in 10,000 CO2 may mark the change to discomfort, because accompanied by the other factors.

Processes of cooking and cleaning, and the appliances of heating and Hghting, escape of ferrosilicon, unburned gases (CO,H, hydrocarbons), steam, each gives an increment of danger.

The air of occupied spaces contains a greater or less amount of dust of both organic and inorganic nature. The organic particles may be either hving or dead. Before methods of bacterial determination were perfected this organic matter was figured largely in chemical examinations of air.

Because it was constantly present and because some explanation of the effect of ''crowd poison" was demanded, a resort was had to the theory of the presence, in expired air, of volatile organic substances poisonous in their nature.

Ransome in 1870 {Jour. Anatomy and Physiology) and UfHemann in 1888 (Archiv.f. Hygiene) used the reduction of potassium permanganate to show the presence of organic matter (0.2 gram in twenty-four hours). Remsen in 1880 (Bulletin of the U. S. National Board of Health) used pumice stone as absorbent and Chapman's suggestion of distillation with alkaline permanganate and estimation of the produced ammonia. In the Massachusetts Institute of Technology Laboratory of Sanitary Chemistry, 1884 to 1887, niany experiments culminated in the conclusion (Marion Talbot, Technology Quarterly, 1887) that the source of the organic matter in the air of rooms was the invisible dust suspended in the air and not in matter given out by healthy persons.

Seegen and Nowack, 1879 (Pfliiger's Archiv., Bd. XIX), found expired air poisonous to small animals. Brown-Sequard and d'Arsonval, 1887-1888 (Comptes Rendus),- found the aqueous washings of expired air poisonous to animals when injected into the blood, and although they recognized the presence of ammoniacal salts, they suspected the presence of alkaloidal substances similar to leucomaines and ptomaines. They held that expired air participated largely in the production of pulmonary tuber-

^40 a

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The Curve of Comfort

20 30 40 50 60 70

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7 ^ m y

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A

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Mean annual temperature and humidity of health resorts:

I Algiers

Arequipa

2 Alexandria

Luxor-winter

3 Cairo

Los Angeles

4 Bermuda

Madeira to white man's residence:

9 New Orleans

Persia lo Havana

India

II Malay Archipelago

Singapore

A-B Most comfortable for indoor workers (Hill).

culosis, and this opinion stimulated investigations, so that for a

period of ten years much work was done alternately pro and con.

STANDARDS OF AIR SUPPLY 9

the previous work, made experiments with modern appKances, and since then observers have accepted his conclusions, i.e., that the healthy lung or skin does not give off poisonous volatile organic compounds; that ammoniacal salts are poisonous to small animals and have been the cause of some otherwise conclusive deaths under experiment.

90°F Fierce

80°F Hot

70°F Uncomfortable

60°F JWarm

50°F Delightful Weather

Chart to Show " Degrees of Discomfort"

By Mark R. Lamb in Mining and Scientific Press, Aug. 27, 1910.

Experience of twenty-five years with various plans of artificial ventilation of closed space leads to a certain standard of air content which permits efficiency of workers and thinkers. This standard must take account of the psychic factors mentioned. The chief of these is a sensation of comfort, or rather the absence of anything which may suggest discomfort.

To illustrate the conditions which seem to meet the requirey"

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— lO CONSERVATION BY SANITATION

ments of the majority, the Curve of Comfort based on such records as are available has been plotted as a beginning of what may prove a rational working hypothesis for architects and engineers. This curve, as will be seen from the references, shows the opinion of experts as to favorable and unfavorable climatic conditions.

The favorable conditions of the air for workers are 64° to 68° F. and 40 to 60 per cent of saturation (humidity). At 60° F. 70 per cent relative humidity is bearable. At 80° to 86° F. there should be as Httle humidity as possible. At 86° F. 60 to 70 per cent humidity is distinctly unfavorable. "A temperature equal to or greater than that of the body cannot be tolerated if the air be saturated with moisture." (Leonard Hill, '' Recent Advances in Physiology and Biochemistry," p. 270.) This is a condition favorable to heat apoplexy. (See chart.)

Extremes of heat are better borne when the air is in motion than when it is still. Extremes of cold, on the other hand, are better borne when the air is still.

Roughly, every increase of 27° F. doubles the amount of water vapor the air can hold in proportion to its weight.

According to Macfie (''Air and Health," p. 97), dry air quickens metabolism, both through its cooling and its drying capacity; damp air slows it with a consequent depression or accumulation of toxins. Water vapor is a far better conductor of heat than dry air, and thus air saturated with vapor at 35° F. is raw and chill. (Hill, p. 258.)

With a temperature only 60° F. and humidity 80 per cent, 12 parts per 10,000 CO2 is common in EngHsh practice, while the reverse, the temperature at 80° F. and humidity 60 per cent, only 6 parts CO2 is common in American practice. Both fall in the unfavorable zone.

It is not suggested that audience halls or living rooms can equal the world's playgrounds in healthful conditions, but surely a nearer approach might be made to the curve of comfort if house dwellers and architects would insist on better management of details.

Chapter III Wholesome Air Supply

The Sanitary Inspector. Testing Apparatus and Recording Instruments

In the near future each city will need an engineer with sufficient training to inspect the conditions of its public buildings, its model dwellings, as to both air supply and waste disposal.

The supply of water is now more nearly regulated; the pressure in the city main forces the water out when the faucet is opened. But the existence of an air duct is not sufficient unless there is like pressure behind it. If there is, a draft is caused as objectionable to most persons as would be the stream of water from the faucet.

Because waste water runs by its own weight from the lowest point, and because carbon dioxide is heavier than air, the popular fallacy is almost ineradicable that waste air will go out of the bottom of the room if it has the chance. These two notions the engineer has to combat. When he circulates sufficient air through a closed, crowded space, drafts is. the cry. When he opens up sufficient ducts, cost is the louder cry. As Professor Woodbridge puts it, '' Your money or your life! "

The sanitary engineer will find certain means of obtaining good air in use. He will be called upon to inspect them to see how far they are answering their purpose and, if not satisfactory, how to improve their working. This is a more difficult task than constructing from the ground, and it is more difficult to persuade an owner to pay for modifying or undoing that for which he thinks he has already paid exorbitantly.

The whole matter of ventilation — change of air in enclosed spaces — is very simple in theory. There are two principles to be carried out scientifically:

(i) Natural ventilation. Contrary to common opinion, foul air coming from human bodies or lights always rises and strives to get out at the highest point, and if a sufficiently large and warmed outlet is furnished so as to keep the air warm until it gets to the roof there will be no trouble. Fresh air will come in from the bottom and sides of the room and should come through many small openings. The one essential is a hot air shaft of sufficient capacity to take all the foul air and hot enough to keep up a good current. The failure comes in expecting a cold air shaft to "draw."

(2) Forced ventilation, or compelling the air to go where it should whether it wants to or not. This is accomplished in three ways :

{a) By a fire at the bottom of a tall chimney drawing up air with great force; open fireplaces.

(Jb) By the so-called Smead or similar system, where the fire is in the basement and openings at the bottom of the rooms permit air to pass by devious ways into the sufficiently hot air shaft. (I never saw one of these which did what it was expected to do.)

{c) By mechanical or fan ventilation, which is now success^ fully apphed to factories, schools, theaters, etc., only when the persons in control of the apparatus are intelligent enough to run it properly.

The so-called plenum system furnishes an admirable circulation of air in a building with smooth ducts, washed air, oblong rooms of no great size, with tight windows, and occupied by relatively few people. The slight pressure outward prevents cold indrafts from the window casings, prevents ingress of dust and outside odors. The heat and humidity may be perfectly regulated. Altogether an apparently ideal system so far as machinery is concerned.